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Sample records for mdct generally underestimates

  1. Impact of Multidetector Computerized Tomography (MDCT) On The General Population

    Energy Technology Data Exchange (ETDEWEB)

    Leite, B.B.; Ribeiro, N.C. [Servico de Radiologia, Hospital de Curry Cabral, Rua da Beneficencia, 8, 1069-166 Lisboa (Portugal)

    2009-05-15

    Multidetector computerized tomography (MDCT) appeared in the early 1990s, as a technological evolution of computerized tomography. As one would expect, the evolution continues and, each year, more powerful equipments appear, with new medical applications. However, the general use of this technique has lead to the dramatic increase on the general population irradiation. Special concern is required regarding the most vulnerable groups, like the pediatric population, the pregnant and the young female. Due to a larger awareness of this irradiation risks, some initiatives have been developed, coming from different areas, aiming to maximize the benefit to risk ratio of MDCT. (author)

  2. Evaluation of image quality and patient safety: paired inspiratory and expiratory MDCT assessment of tracheobronchomalacia in paediatric patients under general anaesthesia with breath-hold technique

    International Nuclear Information System (INIS)

    Lee, Edward Y.; Bastos, Maria d' Almeida; Stark, Cynthia; Carrier, Maureen; Zurakowski, David; Mason, Keira P.

    2012-01-01

    The purpose of our investigation was to evaluate image quality and patient safety in infants and young children who required general anaesthesia with breath-hold technique for paired inspiratory and expiratory multidetector CT (MDCT) assessment of tracheobronchomalacia (TBM). Our hospital's institutional review board approved the review of radiological and clinical data of a consecutive series of 20 paediatric patients who underwent MDCT under general anaesthesia with breath-hold technique for evaluation of TBM from May 2006 to December 2008. For each MDCT study, two fellowship-trained paediatric radiologists reviewed the inspiratory and expiratory MDCT images in an independent, randomised and blinded fashion for the presence of motion artefact at three anatomic levels (upper, middle and lower central airways). The clinical history and anaesthesia outcome, including the occurrence of any adverse events during or following the MDCT examinations until discharge, were also reviewed and recorded. The study population consisted of 20 infants and young children (13 boys/seven girls, mean age 1.7 ± 1.4 years, age range 11 days to 4 years). The imaging quality of all 20 MDCT studies was diagnostic with no motion artefact in 16 studies (80%) and minimal motion artefact in the remaining four studies (20%). Minor adverse events occurred in three patients (15%) that included one patient (5%) with a brief (<60 s) oxygen desaturation during MDCT study, which resolved with oxygen, and two patients (5%) with either a brief (<60 s) oxygen desaturation (n = 1, 5%) or cough (n = 1, 5%) during recovery period, which were completely resolved with oxygen and dexamethasone, respectively. Diagnostic quality paired inspiratory and expiratory MDCT imaging with breath-hold technique can be safely performed in infants and young children under general anaesthesia for evaluation of TBM.

  3. Comparison between MDCT and Grayscale IVUS in a Quantitative Analysis of Coronary Lumen in Segments with or without Atherosclerotic Plaques

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    Falcão, João L. A. A.; Falcão, Breno A. A. [Heart Institute (InCor), University of São Paulo Medical School (USP), São Paulo, SP (Brazil); Gurudevan, Swaminatha V. [Cedars-Sinai Heart Institute, Los Angeles, California, USA (United States); Campos, Carlos M.; Silva, Expedito R.; Kalil-Filho, Roberto; Rochitte, Carlos E.; Shiozaki, Afonso A.; Coelho-Filho, Otavio R.; Lemos, Pedro A. [Heart Institute (InCor), University of São Paulo Medical School (USP), São Paulo, SP (Brazil)

    2015-04-15

    The diagnostic accuracy of 64-slice MDCT in comparison with IVUS has been poorly described and is mainly restricted to reports analyzing segments with documented atherosclerotic plaques. We compared 64-slice multidetector computed tomography (MDCT) with gray scale intravascular ultrasound (IVUS) for the evaluation of coronary lumen dimensions in the context of a comprehensive analysis, including segments with absent or mild disease. The 64-slice MDCT was performed within 72 h before the IVUS imaging, which was obtained for at least one coronary, regardless of the presence of luminal stenosis at angiography. A total of 21 patients were included, with 70 imaged vessels (total length 114.6 ± 38.3 mm per patient). A coronary plaque was diagnosed in segments with plaque burden > 40%. At patient, vessel, and segment levels, average lumen area, minimal lumen area, and minimal lumen diameter were highly correlated between IVUS and 64-slice MDCT (p < 0.01). However, 64-slice MDCT tended to underestimate the lumen size with a relatively wide dispersion of the differences. The comparison between 64-slice MDCT and IVUS lumen measurements was not substantially affected by the presence or absence of an underlying plaque. In addition, 64-slice MDCT showed good global accuracy for the detection of IVUS parameters associated with flow-limiting lesions. In a comprehensive, multi-territory, and whole-artery analysis, the assessment of coronary lumen by 64-slice MDCT compared with coronary IVUS showed a good overall diagnostic ability, regardless of the presence or absence of underlying atherosclerotic plaques.

  4. Determining gastric cancer resectability by dynamic MDCT

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    Pan, Zilai; Zhang, Huan; Du, Lianjun; Ding, Bei; Song, Qi; Ling, Huawei; Huang, Baisong; Chen, Kemin [Jiaotong University, Department of Radiology, Shanghai (China); Yan, Chao [Jiaotong University, Department of Surgery, Shanghai (China)

    2010-03-15

    Multi-detector row CT (MDCT) has been widely used to detect primary lesions and to evaluate TNM staging. In this study we evaluated the accuracy of dynamic MDCT in the preoperative determination of the resectability of gastric cancer. MDCT was used to image 350 cases of gastric cancer diagnosed by biopsy before surgery. MDCT findings regarding TNM staging and resectability were correlated with surgical and pathological findings. The accuracy of MDCT for staging gastric cancer was high, especially for tumour stage T1 (94.3%), lymph node stage N2 (87.3%), and for predicting distant metastases (>96.6%). When resectability was considered to be the outcome, the total accuracy of MDCT was 87.4%, sensitivity was 89.7% and specificity was 76.7%. Results showed high sensitivity for identifying peritoneal seeding (90.0%) and for predicting liver metastasis (80.0%). Dynamic enhanced MDCT is useful for TNM staging of gastric cancers and for predicting tumour respectability preoperatively. (orig.)

  5. Determining gastric cancer resectability by dynamic MDCT

    International Nuclear Information System (INIS)

    Pan, Zilai; Zhang, Huan; Du, Lianjun; Ding, Bei; Song, Qi; Ling, Huawei; Huang, Baisong; Chen, Kemin; Yan, Chao

    2010-01-01

    Multi-detector row CT (MDCT) has been widely used to detect primary lesions and to evaluate TNM staging. In this study we evaluated the accuracy of dynamic MDCT in the preoperative determination of the resectability of gastric cancer. MDCT was used to image 350 cases of gastric cancer diagnosed by biopsy before surgery. MDCT findings regarding TNM staging and resectability were correlated with surgical and pathological findings. The accuracy of MDCT for staging gastric cancer was high, especially for tumour stage T1 (94.3%), lymph node stage N2 (87.3%), and for predicting distant metastases (>96.6%). When resectability was considered to be the outcome, the total accuracy of MDCT was 87.4%, sensitivity was 89.7% and specificity was 76.7%. Results showed high sensitivity for identifying peritoneal seeding (90.0%) and for predicting liver metastasis (80.0%). Dynamic enhanced MDCT is useful for TNM staging of gastric cancers and for predicting tumour respectability preoperatively. (orig.)

  6. Coronary calcium scoring with MDCT: The radiation dose to the breast and the effectiveness of bismuth breast shield

    International Nuclear Information System (INIS)

    Yilmaz, Mehmet Halit; Yasar, Dogan; Albayram, Sait; Adaletli, Ibrahim; Ozer, Harun; Ozbayrak, Mustafa; Mihmanli, Ismail; Akman, Canan

    2007-01-01

    Objective: The purpose of our study was to determine the breast radiation dose during coronary calcium scoring with multidetector computerized tomography (MDCT). We also evaluated the degree of dose reduction by using a bismuth breast shield when performing coronary calcium scoring with MDCT. Materials and methods: The dose reduction achievable by shielding the adult (35 years or older) female breasts was studied in 25 women who underwent coronary calcium scoring with MDCT. All examinations were performed with a 16-MDCT scanner. To compare the shielded versus unshielded breast dose, the examinations were performed with (right breast) and without (left breast) breast shielding in all patients. With this technique the superficial breast doses were calculated. To determine the average glandular breast radiation dose, we imaged an anthropomorphic dosimetric phantom into which calibrated dosimeters were placed to measure the dose to the breast. The phantom was imaged using the same protocol. Radiation doses to the breasts with and without the breast shielding were measured and compared using the Student's t-test. Results: The mean radiation doses with and without the breast shield were 5.71 ± 1.1 mGy versus 9.08 ± 1.5 mGy, respectively. The breast shield provided a 37.12% decrease in radiation dose to the breast with shielding. The difference between the dose received by the breasts with and without bismuth shielding was significant, with a p-value of less than 0.001. Conclusion: The high radiation during MDCT greatly exceeds the recommended doses and should not be underestimated. Bismuth in plane shielding for coronary calcium scoring with MDCT decreased the radiation dose to the breast. We recommend routine use of breast shields in female patients undergoing calcium scoring with MDCT

  7. The usefulness of MDCT in acute intestinal bleeding

    International Nuclear Information System (INIS)

    Kim, Kum Rae; Park, Won Kyu; Kim, Jae Woon; Chang, Jay Chun; Jang, Han Won

    2006-01-01

    We wanted to evaluate the usefulness of MDCT for localizing a bleeding site and for helping make a decision on further management for acute intestinal bleeding. We conducted a retrospective review of 17 consecutive patients who presented with acute intestinal bleeding and who also underwent MDCT before angiography or surgery. The sensitivity of MDCT for detecting acute intestinal bleeding was assessed and compared with that of conventional angiography. The sensitivity of MDCT for the detection of acute intestinal bleeding was 77% (13 or 17), whereas that of angiography was 46% (6 or 13). All the bleeding points that were subsequently detected on angiography were visualized on MDCT. In three cases, the bleeding focus was detected on MDCT and not on angiography. In four cases, both MDCT and angiography did not detect the bleeding focus; for one of these cases, CT during SMA angiography was performed and this detected the active bleeding site. In patients with acute intestinal bleeding, MDCT is a useful image modality to detect the bleeding site and to help decide on further management before performing angiography or surgery. When tumorous lesions are detected, invasive angiography can be omitted

  8. MDCT assessment of resectability in hilar cholangiocarcinoma.

    Science.gov (United States)

    Ni, Qihong; Wang, Haolu; Zhang, Yunhe; Qian, Lijun; Chi, Jiachang; Liang, Xiaowen; Chen, Tao; Wang, Jian

    2017-03-01

    The purpose of this study is to investigate the value of multidetector computed tomography (MDCT) assessment of resectability in hilar cholangiocarcinoma, and to identify the factors associated with unresectability and accurate evaluation of resectability. From January 2007 to June 2015, a total of 77 consecutive patients were included. All patients had preoperative MDCT (with MPR and MinIP) and surgical treatment, and were pathologically proven with hilar cholangiocarcinoma. The MDCT images were reviewed retrospectively by two senior radiologists and one hepatobiliary surgeon. The surgical findings and pathologic results were considered to be the gold standard. The Chi square test was used to identify factors associated with unresectability and accurate evaluation of resectability. The sensitivity, specificity, and overall accuracy of MDCT assessment were 83.3 %, 75.9 %, and 80.5 %, respectively. The main causes of inaccuracy were incorrect evaluation of N2 lymph node metastasis (4/15) and distant metastasis (4/15). Bismuth type IV tumor, main or bilateral hepatic artery involvement, and main or bilateral portal vein involvement were highly associated with unresectability (P hilar cholangiocarcinoma. Bismuth type IV tumor and main or bilateral vascular involvement highly suggest the unresectability of hilar cholangiocarcinoma. Patients without biliary drainage have a more accurate MDCT evaluation of resectability. We suggest MDCT should be performed before biliary drainage to achieve an accurate evaluation of resectability in hilar cholangiocarcinoma.

  9. The application of MDCT in the diagnosis of chest trauma.

    Science.gov (United States)

    Błasińska-Przerwa, Katarzyna; Pacho, Ryszard; Bestry, Iwona

    2013-01-01

    Traumas are the third most common cause of death worldwide, after cardiovascular diseases and neoplasms, and the main cause of death of patients under 40 years of age. Contemporary image diagnosis of chest trauma uses chest X-ray (CXR), multidetector computed tomography (MDCT), transthoracic and transoesophageal ultrasound (USG), X-ray angiography and magnetic resonance. The aim of the present study was to evaluate MDCT results in the examination of posttraumatic chest injuries and to compare the results of CXR and MDCT in chosen chest traumatic injuries. The sixty patients with chest trauma included in the study were diagnosed at the Department of Radiology of the Institute of Tuberculosis and Lung Diseases between May 2004 and October 2007. MDCT was performed in all patients. Two groups with different types of injury (blunt or penetrating chest trauma) were distinguished. The analysis of injuries in both groups was conducted depending on the mechanism of trauma. The detection of 20 selected injuries at CXR and MDCT was compared. Moreover, the compatibility of MDCT with the results of intraoperative assessment and bronchoscopy was analysed. The influence of MDCT on the treatment modality was also assessed. History of blunt chest trauma was found in 51 patients (group 1) and of penetrating trauma in 9 patients (group 2). The most frequent injuries among group 1 were lung contusion and rib fractures, and among group 2 it was pericardial hematoma. Compared to MDCT, the sensitivity and specificity of CXR were 66.7 and 58%, respectively. Change of treatment modality was observed after MDCT in 83% of patients. The sensitivity and specificity of MDCT in diagnosing tracheobronchial injury, compared to bronchoscopy, were 72.7% and 100%, respectively. Compatibility of MDCT results and intraoperative assessment was observed in 43% of patients, and the main reason for discrepancy was underdiagnosis of diaphragm injury in MDCT. MDCT was a valuable diagnostic method in

  10. MDCT angiography and transcatheter embolization in management ...

    African Journals Online (AJOL)

    Hassan Abdelsalam

    2015-12-18

    Dec 18, 2015 ... 14 patients did not have a MDCT and proceeded straight to angiography;. 6 of them showed active bleeding on angiography. Conclusion: MDCT is an excellent technique before angiography and embolization in cases with acute gastrointestinal bleeding. Transcatheter embolization is an effective tool for ...

  11. Mushroom poisoning in children: liver MDCT findings in three cases

    International Nuclear Information System (INIS)

    Cakir, Banu; Kirbas, Ismail; Cevik, Belma; Teksam, Mehmet; Coskun, Mehmet

    2007-01-01

    Wild mushroom poisoning occurs quite frequently in Turkey, usually during late summer and autumn when climatic conditions favour fungal growth. We report the MDCT findings of the liver in three children after mushroom poisoning. In all three patients, precontrast MDCT findings showed diffuse reduction of hepatic attenuation compared with the spleen. Contrast-enhanced MDCT images showed homogeneous contrast enhancement of the liver. All three patients recovered after medical treatment. A follow-up precontrast MDCT examination was performed in one patient in whom the density of the liver parenchyma had returned to normal. (orig.)

  12. Multiphasic MDCT in small bowel volvulus

    International Nuclear Information System (INIS)

    Feng Shiting; Chan Tao; Sun Canhui; Li Ziping; Guo Huanyi; Yang Guangqi; Peng Zhenpeng; Meng Quanfei

    2010-01-01

    Objective: Evaluate the use of MDCT with 3D CT angiography (CTA) and CT portal venography (CTPV) reconstruction for the diagnosis of small bowel volvulus (SBV). Methods: Multiphasic MDCT findings in nine patients (seven males and two females, age range 2-70) with surgically proven SBV were retrospectively reviewed. Non-contrast and double phase contrast enhanced MDCT including 3D CTA and CTPV reconstruction were performed in all the patients. Two experienced abdominal radiologists evaluated the images and defined the location, direction and degree of SBV. Results: On axial MDCT images, all cases show segmental or global dilatation of small intestine. Other findings include circumferential bowel wall thickening in eight cases, halo appearance and hyperemia in seven cases, whirl sign in six cases, beak-like appearance in six cases, closed loops in six cases and ascites in one case. CTA/CTPV showed abnormal courses involving main trunks of superior mesenteric artery (SMA) and superior mesenteric vein (SMV) in seven cases, with or without distortion of their tributaries. Normal course of SMA but abnormal course of SMV was seen in the other two cases. Of all the nine cases, whirl sign was seen in six cases and barber's pole sign in five cases. Dilated SMV was observed in eight cases and abrupt termination of SMA was found in one case. Compared with surgical findings, the location, direction and degree of SBV were correctly estimated in all cases based on CTA/CTPV. Conclusion: Multiphasic MDCT with CTA/CTPV reconstruction can play an important role in the diagnosis of SBV. The location, direction and degree of SBV can all be defined preoperatively using this method.

  13. Multiphasic MDCT in small bowel volvulus

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    Feng Shiting, E-mail: fst1977@163.com [Department of Radiology, The First Affiliated Hospital, Sun Yat-Sen University, 58th The Second Zhongshan Road, Guangzhou 510080 (China); Chan Tao, E-mail: taochan@hku.hk [Department of Diagnostic Radiology, University of Hong Kong, Room 406, Block K, Queen Mary Hospital (Hong Kong); Sun Canhui, E-mail: canhuisun@sina.com [Department of Radiology, The First Affiliated Hospital, Sun Yat-Sen University, 58th The Second Zhongshan Road, Guangzhou 510080 (China); Li Ziping, E-mail: liziping163@tom.com [Department of Radiology, The First Affiliated Hospital, Sun Yat-Sen University, 58th The Second Zhongshan Road, Guangzhou 510080 (China); Guo Huanyi, E-mail: guohuanyi@163.com [Department of Radiology, The First Affiliated Hospital, Sun Yat-Sen University, 58th The Second Zhongshan Road, Guangzhou 510080 (China); Yang Guangqi, E-mail: shwy03@126.com [Department of Radiology, The First Affiliated Hospital, Sun Yat-Sen University, 58th The Second Zhongshan Road, Guangzhou 510080 (China); Peng Zhenpeng, E-mail: ppzhen@21cn.com [Department of Radiology, The First Affiliated Hospital, Sun Yat-Sen University, 58th The Second Zhongshan Road, Guangzhou 510080 (China); Meng Quanfei, E-mail: mzycoco@gmail.com [Department of Radiology, The First Affiliated Hospital, Sun Yat-Sen University, 58th The Second Zhongshan Road, Guangzhou 510080 (China)

    2010-11-15

    Objective: Evaluate the use of MDCT with 3D CT angiography (CTA) and CT portal venography (CTPV) reconstruction for the diagnosis of small bowel volvulus (SBV). Methods: Multiphasic MDCT findings in nine patients (seven males and two females, age range 2-70) with surgically proven SBV were retrospectively reviewed. Non-contrast and double phase contrast enhanced MDCT including 3D CTA and CTPV reconstruction were performed in all the patients. Two experienced abdominal radiologists evaluated the images and defined the location, direction and degree of SBV. Results: On axial MDCT images, all cases show segmental or global dilatation of small intestine. Other findings include circumferential bowel wall thickening in eight cases, halo appearance and hyperemia in seven cases, whirl sign in six cases, beak-like appearance in six cases, closed loops in six cases and ascites in one case. CTA/CTPV showed abnormal courses involving main trunks of superior mesenteric artery (SMA) and superior mesenteric vein (SMV) in seven cases, with or without distortion of their tributaries. Normal course of SMA but abnormal course of SMV was seen in the other two cases. Of all the nine cases, whirl sign was seen in six cases and barber's pole sign in five cases. Dilated SMV was observed in eight cases and abrupt termination of SMA was found in one case. Compared with surgical findings, the location, direction and degree of SBV were correctly estimated in all cases based on CTA/CTPV. Conclusion: Multiphasic MDCT with CTA/CTPV reconstruction can play an important role in the diagnosis of SBV. The location, direction and degree of SBV can all be defined preoperatively using this method.

  14. Suspected pulmonary embolism and deep venous thrombosis: A comprehensive MDCT diagnosis in the acute clinical setting

    International Nuclear Information System (INIS)

    Salvolini, Luca; Scaglione, Mariano; Giuseppetti, Gian Marco; Giovagnoni, Andrea

    2008-01-01

    Both pulmonary arterial and peripheral venous sides of venous thromboembolism (VTE) can now be efficiently and safely investigated by multi-detector CT (MDCT) at the same time by a combined CT angiography/CT venography protocol. In the emergency setting, the use of such a single test for patients suspected of suffering from VTE on a clinical grounds may considerably shorten and simplify diagnostic algorithms. The selection of patients to be submitted to MDCT must follow well-established clinical prediction rules in order to avoid generalized referral to CT on a generic clinical suspicion basis and excessive population exposure to increased ionizing radiation dose, especially in young patients. Clinical and anatomical wide-panoramic capabilities of MDCT allow identification of underlying disease that may explain patients' symptoms in a large number of cases in which VTE is not manifest. The analysis of MDCT additional findings on cardiopulmonary status and total thrombus burden can lead to better prognostic stratification of patients and influence therapeutic options. Some controversial points such as optimal examination parameters, clinical significance of subsegmentary emboli, CT pitfalls and/or possible falsely positive diagnoses, and outcome of untreated patients in which VTE has been excluded by MDCT without additional testing, must of course be taken into careful consideration before the definite role of comprehensive MDCT VTE 'one-stop-shop' diagnosis in everyday clinical practice can be ascertained

  15. Suspected pulmonary embolism and deep venous thrombosis: A comprehensive MDCT diagnosis in the acute clinical setting

    Energy Technology Data Exchange (ETDEWEB)

    Salvolini, Luca [Radiology Department, ' Umberto I' Hospital - Ospedali Riuniti - ' Politecnica delle Marche' University, Via Conca, 60020 Ancona (Italy)], E-mail: lucasalvolini@alice.it; Scaglione, Mariano [Emergency and Trauma CT Section, Department of Radiology, Cardarelli Hospital, Via G. Merliani 31, 80127 Naples (Italy); Giuseppetti, Gian Marco; Giovagnoni, Andrea [Radiology Department, ' Umberto I' Hospital - Ospedali Riuniti - ' Politecnica delle Marche' University, Via Conca, 60020 Ancona (Italy)

    2008-03-15

    Both pulmonary arterial and peripheral venous sides of venous thromboembolism (VTE) can now be efficiently and safely investigated by multi-detector CT (MDCT) at the same time by a combined CT angiography/CT venography protocol. In the emergency setting, the use of such a single test for patients suspected of suffering from VTE on a clinical grounds may considerably shorten and simplify diagnostic algorithms. The selection of patients to be submitted to MDCT must follow well-established clinical prediction rules in order to avoid generalized referral to CT on a generic clinical suspicion basis and excessive population exposure to increased ionizing radiation dose, especially in young patients. Clinical and anatomical wide-panoramic capabilities of MDCT allow identification of underlying disease that may explain patients' symptoms in a large number of cases in which VTE is not manifest. The analysis of MDCT additional findings on cardiopulmonary status and total thrombus burden can lead to better prognostic stratification of patients and influence therapeutic options. Some controversial points such as optimal examination parameters, clinical significance of subsegmentary emboli, CT pitfalls and/or possible falsely positive diagnoses, and outcome of untreated patients in which VTE has been excluded by MDCT without additional testing, must of course be taken into careful consideration before the definite role of comprehensive MDCT VTE 'one-stop-shop' diagnosis in everyday clinical practice can be ascertained.

  16. MDCT diagnosis of penetrating diaphragm injury

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    Bodanapally, Uttam K.; Shanmuganathan, Kathirkamanathan; Mirvis, Stuart E.; Sliker, Clint W.; Fleiter, Thorsten R.; Sarada, Kamal; Miller, Lisa A. [University of Maryland School of Medicine, Department of Diagnostic Radiology, Baltimore, MD (United States); Stein, Deborah M. [University of Maryland, Department of Surgery, Shock Trauma Center, Baltimore, MD (United States); Alexander, Melvin [National Study Center for Trauma and Emergency Medical Systems, Baltimore, MD (United States)

    2009-08-15

    The purpose of the study was to determine the diagnostic sensitivity and specificity of multidetector CT (MDCT) in detection of diaphragmatic injury following penetrating trauma. Chest and abdominal CT examinations performed preoperatively in 136 patients after penetrating trauma to the torso with injury trajectory in close proximity to the diaphragm were reviewed by radiologists unaware of surgical findings. Signs associated with diaphragmatic injuries in penetrating trauma were noted. These signs were correlated with surgical diagnoses, and their sensitivity and specificity in assisting the diagnosis were calculated. CT confirmed diaphragmatic injury in 41 of 47 injuries (sensitivity, 87.2%), and an intact diaphragm in 71 of 98 patients (specificity, 72.4%). The overall accuracy of MDCT was 77%. The most accurate sign helping the diagnosis was contiguous injury on either side of the diaphragm in single-entry penetrating trauma (sensitivity, 88%; specificity, 82%). Thus MDCT has high sensitivity and good specificity in detecting penetrating diaphragmatic injuries. (orig.)

  17. MDCT diagnosis of penetrating diaphragm injury

    International Nuclear Information System (INIS)

    Bodanapally, Uttam K.; Shanmuganathan, Kathirkamanathan; Mirvis, Stuart E.; Sliker, Clint W.; Fleiter, Thorsten R.; Sarada, Kamal; Miller, Lisa A.; Stein, Deborah M.; Alexander, Melvin

    2009-01-01

    The purpose of the study was to determine the diagnostic sensitivity and specificity of multidetector CT (MDCT) in detection of diaphragmatic injury following penetrating trauma. Chest and abdominal CT examinations performed preoperatively in 136 patients after penetrating trauma to the torso with injury trajectory in close proximity to the diaphragm were reviewed by radiologists unaware of surgical findings. Signs associated with diaphragmatic injuries in penetrating trauma were noted. These signs were correlated with surgical diagnoses, and their sensitivity and specificity in assisting the diagnosis were calculated. CT confirmed diaphragmatic injury in 41 of 47 injuries (sensitivity, 87.2%), and an intact diaphragm in 71 of 98 patients (specificity, 72.4%). The overall accuracy of MDCT was 77%. The most accurate sign helping the diagnosis was contiguous injury on either side of the diaphragm in single-entry penetrating trauma (sensitivity, 88%; specificity, 82%). Thus MDCT has high sensitivity and good specificity in detecting penetrating diaphragmatic injuries. (orig.)

  18. MDCT findings in sports and recreational accidents.

    Science.gov (United States)

    Bensch, Frank V; Koivikko, Mika P; Koskinen, Seppo K

    2011-12-01

    Sports and recreational accidents involving critical areas of the body occur commonly in the general population. Reports on their demographics and recommendations for screening procedures are, however, few. To assess injuries of the craniofacial area, spine, and torso resulting from sports and recreational accidents with multidetector computed tomography (MDCT) as primary imaging method in a Level I trauma center. All emergency room CT requests over a time span of 105 months were reviewed retrospectively for trauma mechanism and injury. Patients were identified using an electronic picture archiving and communications system (PACS), and MDCT studies interpreted by two radiologists independently. Of a total of 5898 patients, 492 patients (301 boys/men, 191 girls/women, age range 2-76 years, mean 33.5 years, median 29.5 years) with sports or recreational accidents emerged. A total of 102 traumatic findings were diagnosed, thereof 72 (71%) serious. The three most commonly encountered serious injuries were intracranial injury, fractures of facial bones, and vertebral injuries. The three most common injury mechanisms were bicycling, horseback riding, and team ball sports. Patients from recreational activities were on average significantly younger (29.2 years) than those from sports accidents (36.9 years; P accidents presented with an overall incidence of 21%, of which 71% are serious. The most common mechanisms of injury were bicycling, horseback riding, and team ball sports. The largest incidence of serious injury involved bicycling. Because of the high probability of a serious injury and the high energies that are often involved in these accidents, we recommend ruling out of internal injury by MDCT as the primary imaging modality.

  19. Concordance of coronary artery calcium estimates between MDCT and electron beam tomography.

    Science.gov (United States)

    Daniell, Anthony L; Wong, Nathan D; Friedman, John D; Ben-Yosef, Nachum; Miranda-Peats, Romalisa; Hayes, Sean W; Kang, Xingping; Sciammarella, Maria G; de Yang, Ling; Germano, Guido; Berman, Daniel S

    2005-12-01

    The objective of our study was to compare MDCT with electron beam tomography (EBT) for the quantification of coronary artery calcification (CAC). Sixty-eight patients underwent both MDCT and EBT within 2 months for the quantification of CAC. The images were scored in a blinded fashion and independently by two observers with a minimum of 7 days between the interpretations of images obtained from one scanner type to the other. Presence versus absence of CAC was discordant by EBT versus MDCT in 6% (n = 4) of the cases by observer 1, with one of these cases also discordant by observer 2. All cases except one (aortic calcium misidentified as CAC) were among those with a mean Agatston score of less than 5 present on EBT but absent on MDCT. EBT and MDCT scores correlated well (r = 0.98-0.99). The relative median variability between EBT and MDCT for the Agatston score was 24% for observer 1 and 27% for observer 2 and was 18% and 14%, respectively, for volume score (average for both observers: 27% for Agatston score and 16% for volume score). Scores were higher for EBT than MDCT in approximately half of the cases, with little systematic difference between the two (median EBT-MDCT difference: Agatston score, -0.55; volume score, 3.4 mm3). The absolute median difference averaged for the two observers was 28.75 for the Agatston score and 15.4 mm3 for the volume score. Differences in CAC measurements using EBT and MDCT are similar to interscan differences in CAC measurements previously reported for EBT or for other MDCT scanners individually.

  20. Dual energy MDCT assessment of renal lesions: an overview

    International Nuclear Information System (INIS)

    Mileto, Achille; Marin, Daniele; Nelson, Rendon C.; Boll, Daniel T.; Ascenti, Giorgio

    2014-01-01

    With the expansion of cross-sectional imaging, the number of renal lesions that are incidentally discovered has increased. Multidetector CT (MDCT) is the investigation of choice for characterising and staging renal lesions. Although a definitive diagnosis can be confidently posed for most of them, a number of renal lesions remain indeterminate following MDCT. Further imaging tests are therefore needed, with subsequent increase of healthcare costs, radiation exposure, and patient anxiety. By addressing most of the issues with conventional MDCT imaging, dual-energy MDCT can improve the diagnosis of renal lesions and, potentially, may represent a paradigm shift from a merely attenuation-based to a material-specific spectral imaging investigation. The purpose of this review is to provide an overview of current clinical applications of dual-energy CT in the evaluation of renal lesions. Key Points. (orig.)

  1. Dual energy MDCT assessment of renal lesions: an overview

    Energy Technology Data Exchange (ETDEWEB)

    Mileto, Achille [Duke University Medical Center, Department of Radiology, Durham, NC (United States); University of Messina, Department of Biomedical Sciences and Morphologic and Functional Imaging, Policlinico ' ' G. Martino' ' , Messina (Italy); Marin, Daniele; Nelson, Rendon C.; Boll, Daniel T. [Duke University Medical Center, Department of Radiology, Durham, NC (United States); Ascenti, Giorgio [University of Messina, Department of Biomedical Sciences and Morphologic and Functional Imaging, Policlinico ' ' G. Martino' ' , Messina (Italy)

    2014-02-15

    With the expansion of cross-sectional imaging, the number of renal lesions that are incidentally discovered has increased. Multidetector CT (MDCT) is the investigation of choice for characterising and staging renal lesions. Although a definitive diagnosis can be confidently posed for most of them, a number of renal lesions remain indeterminate following MDCT. Further imaging tests are therefore needed, with subsequent increase of healthcare costs, radiation exposure, and patient anxiety. By addressing most of the issues with conventional MDCT imaging, dual-energy MDCT can improve the diagnosis of renal lesions and, potentially, may represent a paradigm shift from a merely attenuation-based to a material-specific spectral imaging investigation. The purpose of this review is to provide an overview of current clinical applications of dual-energy CT in the evaluation of renal lesions. Key Points. (orig.)

  2. Multi-detector CT (MDCT in bowel and mesenteric injury

    Directory of Open Access Journals (Sweden)

    Vajjalla Ravikumar

    2013-04-01

    Full Text Available Objectives: To evaluate multi-detector CT (MDCT findings in bowel and mesenteric injury due to blunt abdominal trauma.Method: Retrospective evaluation of MDCT scan reports of patients admitted in Hamad Medical Corporation, Doha, Qatar with bowel and mesenteric injury during the period of January 2005 to April 2008.Results: MDCT, without using oral contrast, clearly demonstrated various specific and less specific findings of bowel and mesenteric injury.Conclusion: Multi-detector CT is an excellent diagnostic modality in bowel and mesenteric injury. Routine administration of oral contrast agent is not mandatory for initial evaluation of these patients.

  3. MDCT of renal and mesenteric vessels

    Energy Technology Data Exchange (ETDEWEB)

    Fleischmann, D. [Dept. of Radiology, Stanford Univ. Medical Center, Stanford, CA (United States)

    2003-12-01

    Computed tomography angiography (CTA) with multiple detector-row CT (MDCT) has evolved into an established technique for non-invasive imaging of renal and mesenteric vessels. With adequate selection of acquisition parameters (thin collimation) high spatial-resolution volumetric data sets for subsequent 2D and 3D reformation can be acquired. Contrast medium (CM) injection parameters need to be adjusted to the acquisition speed of the scanners. Whereas fast acquisitions allow a reduction of total CM volume in the setting of CTA, this is not the case when CTA is combined with a second-phase abdominal MDCT acquisition for parenchymal (e.g., hepatic) imaging. Renal CTA is an accurate and reliable test for visualizing vascular anatomy and renal artery stenosis, and therefore a viable alternative to MRA in the assessment of patients with renovascular hypertension and in potential living related renal donors. CTA, combined with abdominal/parenchymal MDCT is a first-line diagnostic test in patients with suspected abdominal vascular emergencies, such as acute mesenteric ischemia, and an excellent tool to assess a wide variety of vascular abnormalities of the abdominal viscera. (orig.)

  4. MDCT of renal and mesenteric vessels

    International Nuclear Information System (INIS)

    Fleischmann, D.

    2003-01-01

    Computed tomography angiography (CTA) with multiple detector-row CT (MDCT) has evolved into an established technique for non-invasive imaging of renal and mesenteric vessels. With adequate selection of acquisition parameters (thin collimation) high spatial-resolution volumetric data sets for subsequent 2D and 3D reformation can be acquired. Contrast medium (CM) injection parameters need to be adjusted to the acquisition speed of the scanners. Whereas fast acquisitions allow a reduction of total CM volume in the setting of CTA, this is not the case when CTA is combined with a second-phase abdominal MDCT acquisition for parenchymal (e.g., hepatic) imaging. Renal CTA is an accurate and reliable test for visualizing vascular anatomy and renal artery stenosis, and therefore a viable alternative to MRA in the assessment of patients with renovascular hypertension and in potential living related renal donors. CTA, combined with abdominal/parenchymal MDCT is a first-line diagnostic test in patients with suspected abdominal vascular emergencies, such as acute mesenteric ischemia, and an excellent tool to assess a wide variety of vascular abnormalities of the abdominal viscera. (orig.)

  5. MDCT imaging of calcinosis in systemic sclerosis

    International Nuclear Information System (INIS)

    Freire, V.; Becce, F.; Feydy, A.; Guérini, H.; Campagna, R.; Allanore, Y.; Drapé, J.-L.

    2013-01-01

    Calcinosis is a typical feature of systemic sclerosis (SSc) and can be found in many different tissues including the superficial soft tissues, periarticular structures, muscles, and tendons. It can also provoke erosive changes on bones. Investigation is conducted most often with plain radiographs. However, when a more detailed assessment is necessary, multidetector computed tomography (MDCT) is helpful owing to its multiplanar reformat (MPR) ability. The purpose of this review is to provide an overview of the various appearances of calcinosis in SSc patients as visualized at MDCT

  6. The value of MDCT in diagnosis of hyaline-vascular Castleman's disease

    International Nuclear Information System (INIS)

    Sun, Xiaoli; Liu, Cheng; Wang, Rengui; Zhu, Xuejun; Gao, Li; Chen, Jiuhong

    2012-01-01

    Purpose: Castleman's disease (CD) is an uncommon entity characterized by a massive growth of lymphoid tissue. There are two types: the hyaline-vascular (HV) type and the plasma cell (PC) type. The purpose of this study was to evaluate the clinical value of multiple detector computed tomography (MDCT) in the diagnosis and planning of treatment for hyaline-vascular CD. Materials and methods: Fifty-two cases of confirmed hyaline-vascular CD were retrospectively reviewed. Unenhanced and contrast-enhanced MDCT scans had been performed in all patients, followed by surgery and pathological analysis of the lesion. Original MDCT transverse and reconstructed images were used for image interpretation. Features of the lesion and its adjacent structures were identified. Results: The lesion was present in the thorax of 24 patients and the abdomen in 28. Obvious features of hyaline-vascular CD (especially feeding vessels and draining veins) and its adjacent structures were demonstrated on 52 patients. Conclusion: On MDCT imaging, original MDCT transverse and reconstructed images provide an excellent tool for diagnosis of hyaline-vascular CD and have high value in the determination of a treatment plan

  7. Preoperative detection of colorectal liver metastases in fatty liver: MDCT or MRI?

    International Nuclear Information System (INIS)

    Kulemann, Vanessa; Schima, Wolfgang; Tamandl, Dietmar; Kaczirek, Klaus; Gruenberger, Thomas; Wrba, Friedrich; Weber, Michael; Ba-Ssalamah, Ahmed

    2011-01-01

    Objective: To compare the diagnostic value of multidetector computed tomography (MDCT) and magnetic resonance imaging (MRI) in the preoperative detection of colorectal liver metastases in diffuse fatty infiltration of the liver, associated with neoadjuvant chemotherapy. Materials and methods: Twenty preoperative tri-phasic MDCT (4-64-row, Siemens) and dynamic contrast-enhanced MRI (1.5 T or 3.0 T, Siemens) examinations of patients with colorectal cancer and liver metastases in diffuse steatosis were retrospectively evaluated. All patients underwent surgical resection for liver metastases (time interval 1-60 days). The amount of fatty infiltration of the liver was determined histopathologically by semi-quantitative percent-wise estimation and ranged from 25 to 75%. Results: Overall, 51 metastases were found by histopathology of the resected liver segments/lobes. The size of the metastases ranged from 0.4 to 13 cm, with 18 (35%) being up to 1 cm in diameter. In the overall rating, MDCT detected 33/51 lesions (65%), and MRI 45/51 (88%). For lesions up to 1 cm, MDCT detected only 2/18 (11%) and MRI 12/18 (66%). One false positive lesion was detected by MDCT. Statistical analysis showed that MRI is markedly superior to MDCT, with a statistically significant difference (p 1 cm. Conclusion: For the detection of colorectal liver metastases after neoadjuvant chemotherapy and consecutive diffuse fatty infiltration of the liver, MRI is superior to MDCT, especially for the detection of small lesions.

  8. MDCT coronary angiography, postprocessing, reading, and reporting - Last but not least

    International Nuclear Information System (INIS)

    Marano, Riccardo; Savino, Giancarlo; Merlino, Biagio; Verrillo, Gemma; Silvestri, Valentina; Tricarico, Francesco; Meduri, Agostino; Natale, Luigi; Bonomo, Lorenzo

    2013-01-01

    Significant literature on MDCT coronary angiography (MDCT-CA) has emerged in the last decade concerning patient's selection, technical aspects of different generations of CT equipment, ECG gating, contrast material and beta-blockade administration, acquisition parameters, and radiation dose. However, the literature regarding postprocessing, reading, and reporting is not so extensive. This review highlights the main elements of MDCT-CA data analysis, thereby allowing the radiologist to take full advantage of this technology and enable a structured report to be generated, promoting best practice with high-quality results

  9. How accurate is unenhanced multidetector-row CT (MDCT) for localization of renal calculi?

    International Nuclear Information System (INIS)

    Goetschi, Stefan; Umbehr, Martin; Ullrich, Stephan; Glenck, Michael; Suter, Stefan; Weishaupt, Dominik

    2012-01-01

    Purpose: To investigate the correlation between unenhanced MDCT and intraoperative findings with regard to the exact anatomical location of renal calculi. Design, setting, and participants: Fifty-nine patients who underwent unenhanced MDCT for suspected urinary stone disease, and who underwent subsequent flexible ureterorenoscopy (URS) as treatment of nephrolithiasis were included in this retrospective study. All MDCT data sets were independently reviewed by three observers with different degrees of experience in reading CT. Each observer was asked to indicate presence and exact anatomical location of any calcification within pyelocaliceal system, renal papilla or renal cortex. Results were compared to intraoperative findings which have been defined as standard of reference. Calculi not described at surgery, but present on MDCT data were counted as renal cortex calcifications. Results: Overall 166 calculi in 59 kidneys have been detected on MDCT, 100 (60.2%) were located in the pyelocaliceal system and 66 (39.8%) in the renal parenchyma. Of the 100 pyelocaliceal calculi, 84 (84%) were correctly located on CT data sets by observer 1, 62 (62%) by observer 2, and 71 (71%) by observer 3. Sensitivity/specificity was 90–94% and 50–100% if only pyelocaliceal calculi measuring >4 mm in size were considered. For pyelocaliceal calculi ≤4 mm in size diagnostic performance of MDCT was inferior. Conclusion: Compared to flexible URS, unenhanced MDCT is accurate for distinction between pyelocaliceal calculi and renal parenchyma calcifications if renal calculi are >4 mm in size. For smaller renal calculi, unenhanced MDCT is less accurate and distinction between a pyelocaliceal calculus and renal parenchyma calcification is difficult.

  10. MDCT findings in sports and recreational accidents

    Energy Technology Data Exchange (ETDEWEB)

    Bensch, Frank V; Koivikko, Mika P; Koskinen, Seppo K (Dept. of Radiology, Toeoeloe Hospital, Helsinki (Finland)), email: frank.bensch@hus.fi

    2011-12-15

    Background. Sports and recreational accidents involving critical areas of the body occur commonly in the general population. Reports on their demographics and recommendations for screening procedures are, however, few. Purpose. To assess injuries of the craniofacial area, spine, and torso resulting from sports and recreational accidents with multidetector computed tomography (MDCT) as primary imaging method in a Level I trauma center. Material and Methods. All emergency room CT requests over a time span of 105 months were reviewed retrospectively for trauma mechanism and injury. Patients were identified using an electronic picture archiving and communications system (PACS), and MDCT studies interpreted by two radiologists independently. Results. Of a total of 5898 patients, 492 patients (301 boys/men, 191 girls/women, age range 2-76 years, mean 33.5 years, median 29.5 years) with sports or recreational accidents emerged. A total of 102 traumatic findings were diagnosed, thereof 72 (71%) serious. The three most commonly encountered serious injuries were intracranial injury, fractures of facial bones, and vertebral injuries. The three most common injury mechanisms were bicycling, horseback riding, and team ball sports. Patients from recreational activities were on average significantly younger (29.2 years) than those from sports accidents (36.9 years; P < 0.001). Only age groups <21 years and 41-50 years differed in injury severity from the other age groups (P = 0.004 and P = 0.063, respectively). Of all trauma mechanisms, only bicycling had a significantly increased risk of injury (P < 0.001). Conclusion. Injuries in sports and recreational accidents presented with an overall incidence of 21%, of which 71% are serious. The most common mechanisms of injury were bicycling, horseback riding, and team ball sports. The largest incidence of serious injury involved bicycling. Because of the high probability of a serious injury and the high energies that are often involved

  11. MDCT findings in sports and recreational accidents

    International Nuclear Information System (INIS)

    Bensch, Frank V; Koivikko, Mika P; Koskinen, Seppo K

    2011-01-01

    Background. Sports and recreational accidents involving critical areas of the body occur commonly in the general population. Reports on their demographics and recommendations for screening procedures are, however, few. Purpose. To assess injuries of the craniofacial area, spine, and torso resulting from sports and recreational accidents with multidetector computed tomography (MDCT) as primary imaging method in a Level I trauma center. Material and Methods. All emergency room CT requests over a time span of 105 months were reviewed retrospectively for trauma mechanism and injury. Patients were identified using an electronic picture archiving and communications system (PACS), and MDCT studies interpreted by two radiologists independently. Results. Of a total of 5898 patients, 492 patients (301 boys/men, 191 girls/women, age range 2-76 years, mean 33.5 years, median 29.5 years) with sports or recreational accidents emerged. A total of 102 traumatic findings were diagnosed, thereof 72 (71%) serious. The three most commonly encountered serious injuries were intracranial injury, fractures of facial bones, and vertebral injuries. The three most common injury mechanisms were bicycling, horseback riding, and team ball sports. Patients from recreational activities were on average significantly younger (29.2 years) than those from sports accidents (36.9 years; P < 0.001). Only age groups <21 years and 41-50 years differed in injury severity from the other age groups (P = 0.004 and P = 0.063, respectively). Of all trauma mechanisms, only bicycling had a significantly increased risk of injury (P < 0.001). Conclusion. Injuries in sports and recreational accidents presented with an overall incidence of 21%, of which 71% are serious. The most common mechanisms of injury were bicycling, horseback riding, and team ball sports. The largest incidence of serious injury involved bicycling. Because of the high probability of a serious injury and the high energies that are often involved

  12. MDCT classification of osseous ankle and foot injuries; MDCT-Klassifikation knoecherner Verletzungen des oberen Sprunggelenks und des Fusses

    Energy Technology Data Exchange (ETDEWEB)

    Opherk, J.P.; Rosenthal, H.; Galanski, M. [Medizinische Hochschule, Abteilung Diagnostische Radiologie, Hannover (Germany)

    2007-03-15

    Conventional radiography plays an essential role in the primary evaluation of acute ankle and foot trauma. In the case of complex injuries, however, subsequent computed tomography (CT) is nowadays recommended. In this connection, multidetector computed tomography (MDCT) allows better temporal, spatial, and contrast resolution compared with the conventional single-slice spiral CT. Multiplanar reformation and three-dimensional reconstruction of the acquired data sets are also helpful tools for critical assessment of therapeutic intervention. This report reviews the potential of the MDCT technique for accurate fracture classification, precise illustration of displaced components, and postoperative control of arrangement of typical lesions. (orig.) [German] Die konventionelle Radiographie spielt bei der initialen Diagnostik akuter Verletzungen des oberen Sprunggelenks und des Fusses eine essenzielle Rolle. Im Falle komplexer Frakturen ist jedoch eine weiterfuehrende computertomographische Diagnostik empfehlenswert. Dabei ist die Multidetektorcomputertomographie (MDCT) der konventionellen Einzeilencomputertomographie hinsichtlich Zeit-, Orts- und Kontrastaufloesung deutlich ueberlegen. Die multiplanare Reformation und dreidimensionale Rekonstruktion des akquirierten Datensatzes sind zudem bei der Beurteilung therapeutischer Interventionen aussagekraeftige Werkzeuge. Der vorliegende Beitrag gibt einen Ueberblick ueber die exakte Frakturklassifikation, die praezise Abbildung dislozierter Komponenten und die postoperative Stellungskontrolle typischer Verletzungen mit dieser Technik. (orig.)

  13. Can independent coronal multiplanar reformatted images obtained using state-of-the-art MDCT scanners be used for primary interpretation of MDCT of the abdomen and pelvis? A feasibility study

    International Nuclear Information System (INIS)

    Sebastian, Sunit; Kalra, Mannudeep K.; Mittal, Pardeep; Saini, Sanjay; Small, William C.

    2007-01-01

    Purpose: To evaluate if coronal reformatted images can be used for primary interpretation of MDCT of the abdomen and pelvis using 64-slice MDCT. Materials and methods: IRB approval was obtained. We reviewed MDCT studies of the abdomen and pelvis of 220 consecutive patients performed with 64 row MDCT with constant scanning parameters. Based on a 0.625 mm raw data set, transverse images were reconstructed at 5 mm and coronal images at 3 mm using standard reconstruction algorithms. Reader familiarity was achieved by simultaneous evaluation of transverse and coronal reformats in an initial group of 20 separate cases for findings in consensus. Two subsequent phases of image analysis were then performed in two groups of 100 patients each. In the first phase two radiologists evaluated the added utility of simultaneous review of MDCT of transverse and coronal reformatted images over transverse images alone in 100 consecutive patients referred for MDCT of the abdomen and pelvis. In the second phase, the same radiologists evaluated whether coronal multiplanar reformats could be used for primary interpretation of MDCT of the abdomen and pelvis in a separate but similar cohort of 100 consecutive abdominopelvic MDCT studies. The number of lesion(s), their location, size of smallest lesion, presence of artifacts and likely diagnosis were noted at each image interpretation. Image quality and confidence for interpretation was evaluated using five-point and three-point scale, respectively. The time required for primary interpretation of coronal reformats and transverse images were recorded. Statistical analysis was performed using Wilcoxon signed rank test. Results: Both readers detected additional findings (n = 37, 35), respectively, on simultaneous review of transverse and coronal reformats as compared with transverse images alone (p < 0.001). Excellent interobserver agreement was noted (r = 0.94-0.96). Both readers detected additional findings (n = 62, 53), respectively, on

  14. Evaluation of aortogenic embolic stroke using multi-detector row CT (MDCT)

    International Nuclear Information System (INIS)

    Mizuno, Masanori; Ooura, Kazumasa; Yamaguchi, Mao; Katsura, Noriyuki; Terayama, Yasuo

    2010-01-01

    Transesophageal cardioechography is one of the useful tools for detecting aortic arteriosclerosis causing aortogenic cerebral embolism. However, it is difficult to perform this method to all of the patients because of the technical difficulties due to patient's condition, especially the severity of atherosclerosis. To avoid the unexpected and adverse events, we are routinely applying multi-detector row CT (MDCT) to those patients. Among 10 cerebral embolic patients with unidentified embolic origin, MDCT revealed arteriosclerotic changes in aorta inducing mobile thrombus in 3 cases. The above data indicates that MDCT is safe and useful tool for diagnosis of aortogenic embolic stroke. (author)

  15. MDCT classification of osseous ankle and foot injuries

    International Nuclear Information System (INIS)

    Opherk, J.P.; Rosenthal, H.; Galanski, M.

    2007-01-01

    Conventional radiography plays an essential role in the primary evaluation of acute ankle and foot trauma. In the case of complex injuries, however, subsequent computed tomography (CT) is nowadays recommended. In this connection, multidetector computed tomography (MDCT) allows better temporal, spatial, and contrast resolution compared with the conventional single-slice spiral CT. Multiplanar reformation and three-dimensional reconstruction of the acquired data sets are also helpful tools for critical assessment of therapeutic intervention. This report reviews the potential of the MDCT technique for accurate fracture classification, precise illustration of displaced components, and postoperative control of arrangement of typical lesions. (orig.) [de

  16. Cardiac Computed Tomography (Multidetector CT, or MDCT)

    Science.gov (United States)

    ... Disease Venous Thromboembolism Aortic Aneurysm More Cardiac Computed Tomography (Multidetector CT, or MDCT) Updated:Sep 19,2016 What is Computerized Tomography (CT)? CT is a noninvasive test that uses ...

  17. Comparison of 640-Slice Multidetector Computed Tomography Versus 32-Slice MDCT for Imaging of the Osteo-odonto-keratoprosthesis Lamina.

    Science.gov (United States)

    Norris, Joseph M; Kishikova, Lyudmila; Avadhanam, Venkata S; Koumellis, Panos; Francis, Ian S; Liu, Christopher S C

    2015-08-01

    To investigate the efficacy of 640-slice multidetector computed tomography (MDCT) for detecting osteo-odonto laminar resorption in the osteo-odonto-keratoprosthesis (OOKP) compared with the current standard 32-slice MDCT. Explanted OOKP laminae and bone-dentine fragments were scanned using 640-slice MDCT (Aquilion ONE; Toshiba) and 32-slice MDCT (LightSpeed Pro32; GE Healthcare). Pertinent comparisons including image quality, radiation dose, and scanning parameters were made. Benefits of 640-slice MDCT over 32-slice MDCT were shown. Key comparisons of 640-slice MDCT versus 32-slice MDCT included the following: percentage difference and correlation coefficient between radiological and anatomical measurements, 1.35% versus 3.67% and 0.9961 versus 0.9882, respectively; dose-length product, 63.50 versus 70.26; rotation time, 0.175 seconds versus 1.000 seconds; and detector coverage width, 16 cm versus 2 cm. Resorption of the osteo-odonto lamina after OOKP surgery can result in potentially sight-threatening complications, hence it warrants regular monitoring and timely intervention. MDCT remains the gold standard for radiological assessment of laminar resorption, which facilitates detection of subtle laminar changes earlier than the onset of clinical signs, thus indicating when preemptive measures can be taken. The 640-slice MDCT exhibits several advantages over traditional 32-slice MDCT. However, such benefits may not offset cost implications, except in rare cases, such as in young patients who might undergo years of radiation exposure.

  18. Multidetector row computed tomography may accurately estimate plaque vulnerability. Does MDCT accurately estimate plaque vulnerability? (Pro)

    International Nuclear Information System (INIS)

    Komatsu, Sei; Imai, Atsuko; Kodama, Kazuhisa

    2011-01-01

    Over the past decade, multidetector row computed tomography (MDCT) has become the most reliable and established of the noninvasive examination techniques for detecting coronary heart disease. Now MDCT is chasing intravascular ultrasound (IVUS) in terms of spatial resolution. Among the components of vulnerable plaque, MDCT may detect lipid-rich plaque, the lipid pool, and calcified spots using computed tomography number. Plaque components are detected by MDCT with high accuracy compared with IVUS and angioscopy when assessing vulnerable plaque. The TWINS study and TOGETHAR trial demonstrated that angioscopic loss of yellow color occurred independently of volumetric plaque change by statin therapy. These 2 studies showed that plaque stabilization and regression reflect independent processes mediated by different mechanisms and time course. Noncalcified plaque and/or low-density plaque was found to be the strongest predictor of cardiac events, regardless of lesion severity, and act as a potential marker of plaque vulnerability. MDCT may be an effective tool for early triage of patients with chest pain who have a normal electrocardiogram (ECG) and cardiac enzymes in the emergency department. MDCT has the potential ability to analyze coronary plaque quantitatively and qualitatively if some problems are resolved. MDCT may become an essential tool for detecting and preventing coronary artery disease in the future. (author)

  19. Diagnostic imaging strategy for MDCT- or MRI-detected breast lesions: use of targeted sonography

    International Nuclear Information System (INIS)

    Nakano, Satoko; Ohtsuka, Masahiko; Mibu, Akemi; Karikomi, Masato; Sakata, Hitomi; Yamamoto, Masahiro

    2012-01-01

    Leading-edge technology such as magnetic resonance imaging (MRI) or computed tomography (CT) often reveals mammographically and ultrasonographically occult lesions. MRI is a well-documented, effective tool to evaluate these lesions; however, the detection rate of targeted sonography varies for MRI detected lesions, and its significance is not well established in diagnostic strategy of MRI detected lesions. We assessed the utility of targeted sonography for multidetector-row CT (MDCT)- or MRI-detected lesions in practice. We retrospectively reviewed 695 patients with newly diagnosed breast cancer who were candidates for breast conserving surgery and underwent MDCT or MRI in our hospital between January 2004 and March 2011. Targeted sonography was performed in all MDCT- or MRI-detected lesions followed by imaging-guided biopsy. Patient background, histopathology features and the sizes of the lesions were compared among benign, malignant and follow-up groups. Of the 695 patients, 61 lesions in 56 patients were detected by MDCT or MRI. The MDCT- or MRI-detected lesions were identified by targeted sonography in 58 out of 61 lesions (95.1%). Patients with pathological diagnoses were significantly older and more likely to be postmenopausal than the follow-up patients. Pathological diagnosis proved to be benign in 20 cases and malignant in 25. The remaining 16 lesions have been followed up. Lesion size and shape were not significantly different among the benign, malignant and follow-up groups. Approximately 95% of MDCT- or MRI-detected lesions were identified by targeted sonography, and nearly half of these lesions were pathologically proven malignancies in this study. Targeted sonography is a useful modality for MDCT- or MRI-detected breast lesions

  20. Malignant renal cysts: Diagnostic performance and strong predictors at MDCT

    International Nuclear Information System (INIS)

    Kim, Dae Yoon; Kim, Jeong Kon; Cho, Kyoung-Sik; Min, Gyeong-Eun; Ahn, Han-Jong

    2010-01-01

    Background: Utilization of multidetector-row CT (MDCT) is anticipated to improve the diagnostic accuracy and reliability for determining malignant cysts. Purpose: To assess the diagnostic accuracy, interobserver agreement, benefit of consensus reading, and strong predictors of malignancy in determining malignant cystic renal masses at MDCT. Material and Methods: Two radiologists independently rated the probability of malignancy at MDCT in 72 benign and 53 malignant cysts. The accuracy and interobserver agreement for determining malignant cysts were evaluated. The strong predictors of malignancy were determined, and in patients with interobserver disagreement for determining malignant cysts, consensus readings were performed. Results: Az value of the two readers was 0.905-0.936 and the sensitivity and specificity were 85-89% and 83-93%, respectively. The overall interobserver agreement for determining the malignant cyst was good as the κ value was 0.696 (% agreement, 61% (76/125)). Thickened irregular wall, thickened irregular septa, and enhancing soft tissue component were strong predictors for malignancy with both readers. In the 17 patients with interobserver disagreement for determining malignant cysts, the sensitivity was improved from 38-63% to 89% by the consensus reading. Conclusion: At MDCT, some false negative decisions for determining malignant cysts can be corrected by consensus reading, and thickened irregular septa, thickened irregular wall, and enhancing soft tissue component are the strong predictors of malignant cysts

  1. Usefulness of multidetector-row computed tomography (MD-CT) for diagnosis and evaluation of cardiovascular anomalies in infants

    International Nuclear Information System (INIS)

    Kani, Hiroyuki; Narabayashi, Isamu; Tanikake, Masato; Matsuki, Mitsuru; Uesugi, Yasuo

    2005-01-01

    We examined the effectiveness of multidetector-row CT (MD-CT) in the diagnosis and evaluation of cardiovascular anomalies in infants. MD-CT was performed 34 times on 21 patients with cardiovascular anomalies. We performed three evaluations: 1) The assessment of the specificity of MD-CT in detecting the morphological features of cardiovascular anomalies. 2) The diameters of aortae with coronary artery (CoA), and the diameters of pulmonary artery, measured by using MD-CT were compared with those by angiography. 3) The amount of exposure to radiation was measured. 1) MD-CT can detect CoA, pulmonary arteriovenous anomalies among extracardiac anomalies in all the patients. The diagnostic accuracy for intracardiac anomalies was poor as only six of the 15 anomalies could be accurately diagnosed. 2) The diameters of aortae and pulmonary artery obtained using MD-CT showed a good correlation with those obtained using arteriography (r=0.97, 0.95). 3) The average dose-length product was 269.2 mGy·cm. And the average effective dose was 5.1 mSv. MD-CT is not suitable for the evaluation of intracardiac anomalies, but is extremely effective in the evaluation of extracardiac major vascular anomalies. On the basis of the amount of information and noninvasive nature, MD-CT should be used first before angiography. (author)

  2. Automatic detection of osteoporotic vertebral fractures in routine thoracic and abdominal MDCT

    Energy Technology Data Exchange (ETDEWEB)

    Baum, Thomas; Dobritz, Martin; Rummeny, Ernst J.; Noel, Peter B. [Technische Universitaet Muenchen, Institut fuer Radiologie, Klinikum rechts der Isar, Muenchen (Germany); Bauer, Jan S. [Technische Universitaet Muenchen, Abteilung fuer Neuroradiologie, Klinikum rechts der Isar, Muenchen (Germany); Klinder, Tobias; Lorenz, Cristian [Philips Research Laboratories, Hamburg (Germany)

    2014-04-15

    To develop a prototype algorithm for automatic spine segmentation in MDCT images and use it to automatically detect osteoporotic vertebral fractures. Cross-sectional routine thoracic and abdominal MDCT images of 71 patients including 8 males and 9 females with 25 osteoporotic vertebral fractures and longitudinal MDCT images of 9 patients with 18 incidental fractures in the follow-up MDCT were retrospectively selected. The spine segmentation algorithm localised and identified the vertebrae T5-L5. Each vertebra was automatically segmented by using corresponding vertebra surface shape models that were adapted to the original images. Anterior, middle, and posterior height of each vertebra was automatically determined; the anterior-posterior ratio (APR) and middle-posterior ratio (MPR) were computed. As the gold standard, radiologists graded vertebral fractures from T5 to L5 according to the Genant classification in consensus. Using ROC analysis to differentiate vertebrae without versus with prevalent fracture, AUC values of 0.84 and 0.83 were obtained for APR and MPR, respectively (p < 0.001). Longitudinal changes in APR and MPR were significantly different between vertebrae without versus with incidental fracture (ΔAPR: -8.5 % ± 8.6 % versus -1.6 % ± 4.2 %, p = 0.002; ΔMPR: -11.4 % ± 7.7 % versus -1.2 % ± 1.6 %, p < 0.001). This prototype algorithm may support radiologists in reporting currently underdiagnosed osteoporotic vertebral fractures so that appropriate therapy can be initiated. circle This spine segmentation algorithm automatically localised, identified, and segmented the vertebrae in MDCT images. (orig.)

  3. BMD measurements of the spine derived from sagittal reformations of contrast-enhanced MDCT without dedicated software

    Energy Technology Data Exchange (ETDEWEB)

    Baum, Thomas, E-mail: thbaum@gmx.de [Institut fuer Roentgendiagnostik, Klinikum rechts der Isar, Technische Universitaet Muenchen, Ismaninger Str. 22, 81675 Muenchen (Germany); Mueller, Dirk, E-mail: dirk.mueller@roe.med.tum.de [Institut fuer Roentgendiagnostik, Klinikum rechts der Isar, Technische Universitaet Muenchen, Ismaninger Str. 22, 81675 Muenchen (Germany); Dobritz, Martin, E-mail: dobritz@roe.med.tum.de [Institut fuer Roentgendiagnostik, Klinikum rechts der Isar, Technische Universitaet Muenchen, Ismaninger Str. 22, 81675 Muenchen (Germany); Rummeny, Ernst J., E-mail: institut@roe.med.tum.de [Institut fuer Roentgendiagnostik, Klinikum rechts der Isar, Technische Universitaet Muenchen, Ismaninger Str. 22, 81675 Muenchen (Germany); Link, Thomas M., E-mail: thomas.link@radiology.ucsf.edu [Musculoskeletal and Quantitative Imaging Research, Department of Radiology and Biomedical Imaging, University of California San Francisco, 185 Berry Street, Suite 350, San Francisco, CA 94107 (United States); Bauer, Jan S., E-mail: jsb@roe.med.tum.de [Institut fuer Roentgendiagnostik, Klinikum rechts der Isar, Technische Universitaet Muenchen, Ismaninger Str. 22, 81675 Muenchen (Germany)

    2011-11-15

    Purpose: To assess QCT equivalent BMD of the lumbar spine in sagittal reformations of routine abdominal contrast-enhanced MDCT with simple PACS measurement tools and to apply this method to MDCT datasets for differentiating patients with and without osteoporotic vertebral fractures. Materials and methods: Eight postmenopausal women (65 {+-} 5years) underwent standard QCT to assess BMD of L1-L3. Afterwards routine abdominal contrast-enhanced MDCT images of these women were obtained and apparent BMD of L1-L3 was measured using the sagittal reformations. The MDCT-to-QCT conversion equation for BMD was calculated with linear regression analysis. The conversion equation was applied to vertebral BMD datasets (L1-L3) of 75 postmenopausal women (66 {+-} 4years). Seventeen of the 75 patients had osteoporotic vertebral fractures. Results: BMD values of contrast-enhanced MDCT were on average 56 mg/ml higher than those of standard QCT. A correlation coefficient of r = 0.94 (p < 0.05) was calculated for the BMD values of MDCT and standard QCT with the conversion equation BMD{sub QCT} = 0.69 x BMD{sub MDCT} - 11 mg/ml. Accordingly converted BMD values of patients with vertebral fractures were significantly lower than those of patients without vertebral fractures (69 mg/ml vs. 85 mg/ml; p < 0.05). Using ROC analysis to differentiate patients with and without vertebral fractures, AUC = 0.72 was obtained for converted BMD values (p < 0.05). Short- and long-term reproducibility errors for BMD measurements in the sagittal reformations amounted 2.09% and 7.70%, respectively. Conclusion: BMD measurements of the spine could be computed in sagittal reformations of routine abdominal contrast-enhanced MDCT with minimal technical and time effort. Using the conversion equation, the acquired BMD data could differentiate patients with and without osteoporotic vertebral fractures.

  4. Multidetector computed tomography enteroclysis (MDCT-E) with neutral enteral and IV contrast enhancement in tumor detection

    Energy Technology Data Exchange (ETDEWEB)

    Romano, Stefania; Lutio, Elisabetta de; Romano, Luigia [Cardarelli Hospital, Department of Diagnostic Imaging, Naples (Italy); Rollandi, Gian Andrea [San Martino Hospital, 2. Service of Radiology, Genova (Italy); Grassi, Roberto [Second University of Naples, Institute of Radiology, Naples (Italy); Maglinte, Dean D.T. [Indiana University School of Medicine, Department of Radiology, Indianapolis, IN (United States)

    2005-06-01

    The aim of our study was to evaluate the reliability of MDCT-enteroclysis (MDCT-E), an emerging technique of small bowel examination that combines the advantages of MDCT examination of the abdomen and the enteral volume challenge of enteroclysis, in evaluation of small bowel neoplasms. In our institutions, MDCT-E was used to study 456 patients (age range 21-84 years, mean 53 years) admitted for suspicion of small bowel disease. All examinations were done on multichannel CT units, 129 on a 16-slice scanner and 327 on a four-slice scanner. Post-processing and multiplanar reformatting and interpretation were performed on dedicated workstations. After adequate gastrointestinal preparation and naso-enteric intubation, small bowel was distended by methylcellulose infused by a peristaltic pump. One volumetric MDCT acquisition was obtained after 120-130 ml of intravenous contrast medium. Multiplanar reformatting was based on the image reconstruction parameters from 3 to 4 mm. Forty-five small bowel neoplasms were found; in the remaining cases, 223 Crohn's diseases and 149 other abnormalities were detected. All findings were confirmed by surgery, endoscopy or clinical follow-up. In our experience, MDCT-E with neutral enteral and IV contrast seems to be a reliable method in the diagnosis of small bowel neoplasms. (orig.)

  5. Fulminant hepatic failure in children: Etiology, histopathology and MDCT findings

    International Nuclear Information System (INIS)

    Cakir, Banu; Kirbas, Ismail; Demirhan, Beyhan; Tarhan, Nefise Cagla; Bozkurt, Alper; Ozcay, Figen; Coskun, Mehmet

    2009-01-01

    Introduction: The purpose of this study is to determine the etiologies, histopathology and MDCT findings of children with fulminant hepatic failure admitted to our institution. Materials and methods: Between June 2004 and November 2006, 15 children with fulminant hepatic failure who underwent MDCT were included retrospectively in this study. Twelve patients had liver biopsies. The patients were divided into three groups as hyperacute (Group I), acute (Group II) and subacute (Group III) depending on onset of hepatic encephalopathy. Results: Hepatitis A in 4 patients, non-A, non-E hepatitis in 4; mushroom poisoning in 3; fulminant Wilson's disease in 2; autoimmune hepatitis in 1; and both hepatitis B and toxic hepatitis (with leflunomide treatment) in 1 patient were detected. MDCT of all three groups revealed diffuse reduction in hepatic attenuation in 11 patients; ascites in 9; periportal edema in 6; edema of gallbladder wall in 6; splenomegaly in 6; heterogeneous hepatic parenchyma in 6; hepatomegaly in 3; irregular contours of liver in 2; multiple micronodules in 1 and necrotic areas and regeneration in liver parenchyma in 2 patients. Histopathologic evaluation of liver biopsies showed massive hepatic necrosis, inflammatory cell infiltration and ductular proliferation in 8 patients, periportal edema in 6, edema of gallbladder wall in 5, regenerating nodules and fibrous septa consistent with cirrhotic pattern in 2, and regenerating nodules and necrotic areas in 2 patients. Conclusion: The most common MDCT findings in fulminant hepatic failure were diffuse reduction in hepatic attenuation and ascites. Massive hepatic necrosis was the most common histopathologic finding.

  6. Fulminant hepatic failure in children: Etiology, histopathology and MDCT findings

    Energy Technology Data Exchange (ETDEWEB)

    Cakir, Banu [Baskent University Faculty of Medicine Department of Radiology, Fevzi Cakmak Cd. 10, Sok. No: 45, Bahcelievler, Ankara 06490 (Turkey)], E-mail: banutopcu@yahoo.com; Kirbas, Ismail [Baskent University Faculty of Medicine Department of Radiology, Fevzi Cakmak Cd. 10, Sok. No: 45, Bahcelievler, Ankara 06490 (Turkey)], E-mail: drismailk@yahoo.com; Demirhan, Beyhan [Baskent University Faculty of Medicine Department of Pathology, Fevzi Cakmak Cd. 10, Sok. No: 45, Bahcelievler, Ankara 06490 (Turkey)], E-mail: beyhand@baskent-ank.edu.tr; Tarhan, Nefise Cagla [Baskent University Faculty of Medicine Department of Radiology, Fevzi Cakmak Cd. 10, Sok. No: 45, Bahcelievler, Ankara 06490 (Turkey)], E-mail: caglat@gmail.com; Bozkurt, Alper [Baskent University Faculty of Medicine Department of Radiology, Fevzi Cakmak Cd. 10, Sok. No: 45, Bahcelievler, Ankara 06490 (Turkey)], E-mail: abozkurt78@hotmail.com; Ozcay, Figen [Baskent University Faculty of Medicine Department of Pediatric Gastroenterology, Fevzi Cakmak Cd. 10, Sok. No: 45, Bahcelievler, Ankara 06490 (Turkey)], E-mail: fozcay@baskent.edu.tr; Coskun, Mehmet [Baskent University Faculty of Medicine Department of Radiology, Fevzi Cakmak Cd. 10, Sok. No: 45, Bahcelievler, Ankara 06490 (Turkey)], E-mail: mcoskun@baskent-ank.edu.tr

    2009-11-15

    Introduction: The purpose of this study is to determine the etiologies, histopathology and MDCT findings of children with fulminant hepatic failure admitted to our institution. Materials and methods: Between June 2004 and November 2006, 15 children with fulminant hepatic failure who underwent MDCT were included retrospectively in this study. Twelve patients had liver biopsies. The patients were divided into three groups as hyperacute (Group I), acute (Group II) and subacute (Group III) depending on onset of hepatic encephalopathy. Results: Hepatitis A in 4 patients, non-A, non-E hepatitis in 4; mushroom poisoning in 3; fulminant Wilson's disease in 2; autoimmune hepatitis in 1; and both hepatitis B and toxic hepatitis (with leflunomide treatment) in 1 patient were detected. MDCT of all three groups revealed diffuse reduction in hepatic attenuation in 11 patients; ascites in 9; periportal edema in 6; edema of gallbladder wall in 6; splenomegaly in 6; heterogeneous hepatic parenchyma in 6; hepatomegaly in 3; irregular contours of liver in 2; multiple micronodules in 1 and necrotic areas and regeneration in liver parenchyma in 2 patients. Histopathologic evaluation of liver biopsies showed massive hepatic necrosis, inflammatory cell infiltration and ductular proliferation in 8 patients, periportal edema in 6, edema of gallbladder wall in 5, regenerating nodules and fibrous septa consistent with cirrhotic pattern in 2, and regenerating nodules and necrotic areas in 2 patients. Conclusion: The most common MDCT findings in fulminant hepatic failure were diffuse reduction in hepatic attenuation and ascites. Massive hepatic necrosis was the most common histopathologic finding.

  7. Ectopic Varices in Colonic Stoma: MDCT Findings

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Jae Woong; Lee, Chang Hee; Kim, Kyeong Ah; Park, Cheol Min; Kim, Jin Yong [Guro Hospital of Korea University, Seoul (Korea, Republic of)

    2006-12-15

    We describe the 2D reformatted and 3D volume rendered images by MDCT in a patient with an episode of acute bleeding from the colonic stoma. This case indicates that the 2D reformatted and 3D volume rendered images are useful to detect this rare complication of portal hypertension, and they help to tailor adequate treatment for the patients with bleeding from stomal varices. Ectopic varices are an uncommon cause of gastrointestinal hemorrhage, but they account for up to 5% of all variceal bleedings (1). Bleeding from stomal varices has been reported in up to 20% of the patients suffering with chronic liver failure with permanent stoma (2). However, the diagnosis of stomal varices is difficult because bleeding from stoma may also be associated with lower gastrointestinal bleeding. To the best of our knowledge, the 2D reformatted and 3D volume rendered images by MDCT for visualization of ectopic stomal varices have not been previously reported in the medical literature.

  8. MDCT assessment of CAD in type-2 diabetic subjects with diabetic neuropathy: the role of Charcot neuro-arthropathy

    International Nuclear Information System (INIS)

    Marano, Riccardo; Savino, Giancarlo; Merlino, Biagio; Pirro, Federica; Rutigliano, Claudia; Santangelo, Carolina; Minoiu, Aurelian Costin; Natale, Luigi; Bonomo, Lorenzo; Pitocco, Dario; Di Stasio, Enrico; Trani, Carlo

    2016-01-01

    To compare the CACS and CAD severity assessed by MDCT in neuropathic type-2 diabetic patients with and without Charcot-neuroarthropathy (CN). Thirty-four CN asymptomatic-patients and 36 asymptomatic-patients with diabetic-neuropathy (DN) without CN underwent MDCT to assess CACS and severity of CAD. Patients were classified as positive for significant CAD in presence of at least one stenosis >50 % on MDCT-coronary-angiography (MDCT-CA). Groups were matched for age, sex and traditional CAD risk-factors. The coronary-angiography (CA) was performed in all patients with at least a significant stenosis detected by MDCT-CA, both as reference and eventually as treatment. CN patients showed higher rates of significant CAD in comparison with DN subjects [p < 0.001], while non-significant differences were observed in CACS (p = 0.980). No significant differences were also observed in CACS distribution in all subjects for stenosis ≥/<50 % (p = 0.814), as well as in both groups (p = 0.661 and 0.559, respectively). The MDCT-CA showed an overall diagnostic-accuracy for significant CAD of 87 %. These preliminary data suggest that CN-patients have a higher prevalence of severe CAD in comparison with DN-patients, while coronary plaques do not exhibit an increased amount of calcium. MDCT may be helpful to assess the CV risk in such asymptomatic type-2-diabetic patients with autonomic-neuropathy. (orig.)

  9. MDCT assessment of CAD in type-2 diabetic subjects with diabetic neuropathy: the role of Charcot neuro-arthropathy

    Energy Technology Data Exchange (ETDEWEB)

    Marano, Riccardo; Savino, Giancarlo; Merlino, Biagio; Pirro, Federica; Rutigliano, Claudia; Santangelo, Carolina; Minoiu, Aurelian Costin; Natale, Luigi; Bonomo, Lorenzo [Catholic University of Rome, ' ' A. Gemelli' ' University Hospital, Department of Radiological Sciences - Institute of Radiology, Rome (Italy); Pitocco, Dario [Catholic University of Rome, ' ' A. Gemelli' ' University Hospital, Department of Internal Medicine, Rome (Italy); Di Stasio, Enrico [Catholic University of Rome, ' ' A. Gemelli' ' University Hospital, Department of Clinical Biochemistry, Rome (Italy); Trani, Carlo [Catholic University of Rome, ' ' A. Gemelli' ' University Hospital, Department of Cardiovascular Medicine - Institute of Cardiology, Rome (Italy)

    2016-03-15

    To compare the CACS and CAD severity assessed by MDCT in neuropathic type-2 diabetic patients with and without Charcot-neuroarthropathy (CN). Thirty-four CN asymptomatic-patients and 36 asymptomatic-patients with diabetic-neuropathy (DN) without CN underwent MDCT to assess CACS and severity of CAD. Patients were classified as positive for significant CAD in presence of at least one stenosis >50 % on MDCT-coronary-angiography (MDCT-CA). Groups were matched for age, sex and traditional CAD risk-factors. The coronary-angiography (CA) was performed in all patients with at least a significant stenosis detected by MDCT-CA, both as reference and eventually as treatment. CN patients showed higher rates of significant CAD in comparison with DN subjects [p < 0.001], while non-significant differences were observed in CACS (p = 0.980). No significant differences were also observed in CACS distribution in all subjects for stenosis ≥/<50 % (p = 0.814), as well as in both groups (p = 0.661 and 0.559, respectively). The MDCT-CA showed an overall diagnostic-accuracy for significant CAD of 87 %. These preliminary data suggest that CN-patients have a higher prevalence of severe CAD in comparison with DN-patients, while coronary plaques do not exhibit an increased amount of calcium. MDCT may be helpful to assess the CV risk in such asymptomatic type-2-diabetic patients with autonomic-neuropathy. (orig.)

  10. [Visualization of laryngopharynx during swallowing of negative contrast media (air) with cine mode 64-row MDCT].

    Science.gov (United States)

    Fudeya, Taku; Otake, Shoichiro; Watabe, Hirotaka; Mitsuoka, Takashi; Yoshikawa, Akitoshi

    2010-05-20

    Video fluoroscopic examination of swallowing generally needs a contrast media such as a barium sulfate. Since the examination is usually performed in patients with dysphasia, there is a risk of aspiration. We tried to visualize the laryngopharynx during swallowing of negative contrast media (air) with 64-row multi-detector computed tomography (64-MDCT). Cine mode 64-MDCT was performed to visualize the laryngopharynx in 4 healthy volunteers during swallowing of negative contrast media (air). The data were converted to three-dimensional (3D) images of 2 conditions (air and bone) and sagittal images of the soft tissue condition at a workstation. These images were sent to a personal computer and modeled to 3D cine images with Digital Imaging and Communication in Medicine (DICOM) Viewer and Quick Time Player. 3D cine images demonstrated movements of the epiglottis, vallecula, piriform sinus, tongue, pharyngeal wall, hyoid bone and thyroid cartilage.

  11. Visualization of subtle temporal bone structures. Comparison of cone beam CT and MDCT

    International Nuclear Information System (INIS)

    Pein, M.K.; Plontke, S.K.; Brandt, S.; Koesling, S.

    2014-01-01

    The purpose of this study was to compare the visualization of subtle, non-pathological temporal bone structures on cone beam computed tomography (CBCT) and multi-detector computed tomography (MDCT) in vivo. Temporal bone studies of images from 38 patients archived in the picture archiving and communication system (PACS) were analyzed (slice thickness MDCT 0.6 mm and CBCT 0.125 mm) of which 23 were imaged by MDCT and 15 by CBCT using optimized standard protocols. Inclusion criteria were normal radiological findings, absence of previous surgery and anatomical variants. Images were evaluated blind by three trained observers. Using a five-point scale the visualization of ten subtle structures of the temporal bone was analyzed. Subtle middle ear structures showed a tendency to be more easily distinguishable by CBCT with significantly better visualization of the tendon of the stapedius muscle and the crura of the stapes on CBCT (p = 0.003 and p = 0.033, respectively). In contrast, inner ear components, such as the osseus spiral lamina and the modiolus tended to be better detectable on MDCT, showing significant differences for the osseous spiral lamina (p = 0.001). The interrater reliability was 0.73 (Cohen's kappa coefficient) and intraobserver reliability was 0.89. The use of CBCT and MDCT allows equivalent and excellent imaging results if optimized protocols are chosen. With both imaging techniques subtle temporal bone structures could be visualized with a similar degree of definition. In vivo differences do not seem to be as large as suggested in several previous studies. (orig.) [de

  12. Chronic mitral regurgitation detected on cardiac MDCT: differentiation between functional and valvular aetiologies.

    LENUS (Irish Health Repository)

    Killeen, Ronan P

    2012-02-01

    OBJECTIVE: To determine whether cardiac computed tomography (MDCT) can differentiate between functional and valvular aetiologies of chronic mitral regurgitation (MR) compared with echocardiography (TTE). METHODS: Twenty-seven patients with functional or valvular MR diagnosed by TTE and 19 controls prospectively underwent cardiac MDCT. The morphological appearance of the mitral valve (MV) leaflets, MV geometry, MV leaflet angle, left ventricular (LV) sphericity and global\\/regional wall motion were analysed. The coronary arteries were evaluated for obstructive atherosclerosis. RESULTS: All control and MR cases were correctly identified by MDCT. Significant differences were detected between valvular and control groups for anterior leaflet length (30 +\\/- 7 mm vs. 22 +\\/- 4 mm, P < 0.02) and thickness (3.0 +\\/- 1 mm vs. 2.2 +\\/- 1 mm, P < 0.01). High-grade coronary stenosis was detected in all patients with functional MR compared with no controls (P < 0.001). Significant differences in those with\\/without MV prolapse were detected in MV tent area (-1.0 +\\/- 0.6 mm vs. 1.3 +\\/- 0.9 mm, P < 0.0001) and MV tent height (-0.7 +\\/- 0.3 mm vs. 0.8 +\\/- 0.8 mm, P < 0.0001). Posterior leaflet angle was significantly greater for functional MR (37.9 +\\/- 19.1 degrees vs. 22.9 +\\/- 14 degrees , P < 0.018) and less for valvular MR (0.6 +\\/- 35.5 degrees vs. 22.9 +\\/- 14 degrees, P < 0.017). Sensitivity, specificity, and positive and negative predictive values of MDCT were 100%, 95%, 96% and 100%. CONCLUSION: Cardiac MDCT allows the differentiation between functional and valvular causes of MR.

  13. Novel technique for addressing streak artifact in gated dual-source MDCT angiography utilizing ECG-editing

    Energy Technology Data Exchange (ETDEWEB)

    Meyer, Laura T.; Boll, Daniel T. [Duke University Medical Center, Department of Radiology, Box 3808, Durham, NC (United States)

    2008-11-15

    Streak artifact is an important source of image degradation in computed tomographic imaging. In coronary MDCT angiography, streak artifact from pacemaker leads in the SVC can render segments of the right coronary artery uninterpretable. With current technology in clinical practice, there is no effective way to eliminate streak artifact in coronary MDCT angiography entirely. We propose a technique to minimize the impact of streak artifact in retrospectively gated coronary MDCT angiography by utilizing small shifts in the reconstruction window. In our experience, previously degraded portions of the coronary vasculature were able to be well evaluated using this technique. (orig.)

  14. Diagnostic accuracy of contemporary multidetector computed tomography (MDCT) for the detection of lumbar disc herniation

    Energy Technology Data Exchange (ETDEWEB)

    Notohamiprodjo, S.; Stahl, R.; Braunagel, M.; Kazmierczak, P.M.; Thierfelder, K.M.; Treitl, K.M.; Wirth, S. [University Hospital of Munich, LMU Munich, Institute for Clinical Radiology, Munich (Germany); Notohamiprodjo, M. [University Hospital Tuebingen, Eberhard Karls University Tuebingen, Diagnostic and Interventional Radiology, Tuebingen (Germany)

    2017-08-15

    To evaluate the diagnostic accuracy of multidetector CT (MDCT) for detection of lumbar disc herniation with MRI as standard of reference. Patients with low back pain underwent indicated MDCT (128-row MDCT, helical pitch), 60 patients with iterative reconstruction (IR) and 67 patients with filtered back projection (FBP). Lumbar spine MRI (1.5 T) was performed within 1 month. Signal-to-noise ratios (SNR) of cerebrospinal fluid (CSF), annulus fibrosus (AF) and the spinal cord (SC) were determined for all modalities. Two readers independently rated image quality (IQ), diagnostic confidence and accuracy in the diagnosis of lumbar disc herniation using MRI as standard of reference. Inter-reader correlation was assessed with weighted κ. Sensitivity, specificity, precision and accuracy of MDCT for disc protrusion were 98.8%, 96.5%, 97.1%, 97.8% (disc level), 97.7%, 92.9%, 98.6%, 96.9% (patient level). SNR of IR was significantly higher than FBP. IQ was significantly better in IR owing to visually reduced noise and improved delineation of the discs. κ (>0.90) was excellent for both algorithms. MDCT of the lumbar spine yields high diagnostic accuracy for detection of lumbar disc herniation. IR improves image quality so that the provided diagnostic accuracy is principally equivalent to MRI. (orig.)

  15. Baseline MDCT findings after prosthetic heart valve implantation provide important complementary information to echocardiography for follow-up purposes

    Energy Technology Data Exchange (ETDEWEB)

    Sucha, Dominika; Mali, Willem P.T.M.; Habets, Jesse [University Medical Center Utrecht, Department of Radiology, Utrecht (Netherlands); Chamuleau, Steven A.J. [University Medical Center Utrecht, Department of Cardiology, Utrecht (Netherlands); Symersky, Petr [VU Medical Center, Department of Cardiothoracic Surgery, Amsterdam (Netherlands); Meijs, Matthijs F.L. [Thoraxcentrum Twente, Medisch Spectrum Twente, Department of Cardiology, Enschede (Netherlands); Brink, Renee B.A. van den [Academic Medical Center, Department of Cardiology, Amsterdam (Netherlands); Mol, Bas A.J.M. de [Academic Medical Center, Department of Cardiothoracic Surgery, Amsterdam (Netherlands); Herwerden, Lex A. van [University Medical Center Utrecht, Department of Cardiothoracic Surgery, Utrecht (Netherlands); Budde, Ricardo P.J. [University Medical Center Utrecht, Department of Radiology, Utrecht (Netherlands); Erasmus University Medical Center, Department of Radiology, Rotterdam (Netherlands)

    2016-04-15

    Recent studies have proposed additional multidetector-row CT (MDCT) for prosthetic heart valve (PHV) dysfunction. References to discriminate physiological from pathological conditions early after implantation are lacking. We present baseline MDCT findings of PHVs 6 weeks post implantation. Patients were prospectively enrolled and TTE was performed according to clinical guidelines. 256-MDCT images were systematically assessed for leaflet excursions, image quality, valve-related artefacts, and pathological and additional findings. Forty-six patients were included comprising 33 mechanical and 16 biological PHVs. Overall, MDCT image quality was good and relevant regions remained reliably assessable despite mild-moderate PHV-artefacts. MDCT detected three unexpected valve-related pathology cases: (1) prominent subprosthetic tissue, (2) pseudoaneurysm and (3) extensive pseudoaneurysms and valve dehiscence. The latter patient required valve surgery to be redone. TTE only showed trace periprosthetic regurgitation, and no abnormalities in the other cases. Additional findings were: tilted aortic PHV position (n = 3), pericardial haematoma (n = 3) and pericardial effusion (n = 3). Periaortic induration was present in 33/40 (83 %) aortic valve patients. MDCT allowed evaluation of relevant PHV regions in all valves, revealed baseline postsurgical findings and, despite normal TTE findings, detected three cases of unexpected, clinically relevant pathology. (orig.)

  16. Role of MDCT angiography in the preoperative evaluation of anomalous pulmonary venous connection associated with complex cardiac abnormality

    International Nuclear Information System (INIS)

    Liu Jingzhe; Wu Qingyu; Xu Yufeng; Bai Yan; Liu Zhibo; Li Hongyin; Zhu Jiemin

    2012-01-01

    Objectives: To evaluate the diagnostic accuracy of MDCT in patients with APVC associated with complex cardiac abnormality. Materials and methods: The clinical and imaging data of 39 patients with APVC confirmed by surgery were retrospectively reviewed. According to accompanied cardiac malformations, patients with APVC were classified as isolated and complex group. Using surgical findings as the reference standard, diagnostic agreement of MDCT, TTE (transthoracic echocardiography) and cardiac catheterization for detection of APVC were calculated. Results: At surgery, 27 patients were considered as complex APVCs. MDCT correctly diagnosed APVC in all patients and the diagnostic agreements between MDCT and surgery were both 100% in isolated and complex groups. All 5 APVCs which could not be detected at cardiac catheterization were in complex group, and the diagnostic agreements were 100% and 76.2% in isolated and complex groups, respectively. At TTE, eight of nine disagreed patients were complex cases. The diagnostic agreements of TTE were 91.7% and 66.7% in isolated and complex groups, respectively. The dysmorphic pulmonary veins were identified in 11 patients by MDCT. Conclusions: MDCT is superior to catheterization and TTE in evaluation of APVC associated with complex cardiac defects.

  17. Myocardial bridging as evaluated by 16 row MDCT

    International Nuclear Information System (INIS)

    Canyigit, Murat; Hazirolan, Tuncay; Karcaaltincaba, Musturay; Dagoglu, Merve Gulbiz; Akata, Deniz; Aytemir, Kudret; Oto, Ali; Balkanci, Ferhun; Akpinar, Erhan; Besim, Aytekin

    2009-01-01

    Purpose: The purpose of this study is to find out the prevalence, appearance and clinical symptoms of myocardial bridging (MB) by MDCT coronary angiography (CTA). Materials and methods: A total of 280 (50 females) consecutive patients followed with coronary artery disease or postoperative stent and bypass control, underwent CTA performed by 16-MDCT scanner between January 2006 and April 2006. Short axis multiplanar reformatted images were evaluated. MBs were classified as complete and incomplete bridges with respect to continuity of the myocardium over the tunneled segment of left anterior descending artery (LAD) in interventricular groove and the cut-off value is 1.3 mm. Patients diagnosed with MB on CTA who had prior catheter angiography studies were re-evaluated for the presence of MB. Results: One hundred and twenty MBs [98 (81.6%) on LAD, 2 (1.6%) on diagonal branch, 11 (9.1%) on obtuse marginal, 4 (3.3%) on right coronary artery, 5 (4.1%) on ramus intermedius artery] were detected in 108 (38.5%) patients. Eighty-five (70.8%) of bridged segments in 79 (28.2%) patients were complete and the rest [35 (29.2%) in 34 (12.1%) patients] were incomplete. In 12 patients two MBs (either on different arteries or on the same artery) were detected. The length of bridged segments in patients with complete and incomplete MBs varied between 4-50.9 mm (mean 18 mm) and 4-37.3 mm (mean 13.6 mm), respectively, and the depth of myocardium over the artery ranged between 1-6.4 mm (mean 2.3 mm) and 1-1.2 mm (mean 1 mm), respectively. Thirty (27.7%) out of 108 patients, in whom MB was detected on CTA, were found to have correlative catheter angiography studies, retrospectively and MB was detected only in 4 (13.3%) out of 30 patients. Conclusion: MDCT coronary angiography is a non-invasive, efficient method in the diagnosis of MB avoiding the procedural risks that catheter angiography carries. MDCT coronary angiography allows direct visualization of the bridge itself and may thus give

  18. Utility of 64-row MDCT in assessment of neonates with congenital EA and distal TEF

    Directory of Open Access Journals (Sweden)

    Hosam El-Deen Galal Mohamed El-Malah

    2015-12-01

    Conclusion: Preoperative MDCT scan with MPVR, 3D TL-VR of 64-row MDCT which is a noninvasive technique could provide more accurate information about the assessment of the origin of the fistula, the distal esophageal pouches and inter-pouch distance in neonates with EA and distal TEF.

  19. MDCT for computerized volumetry of pneumothoraces in pediatric patients.

    Science.gov (United States)

    Cai, Wenli; Lee, Edward Y; Vij, Abhinav; Mahmood, Soran A; Yoshida, Hiroyuki

    2011-03-01

    Our purpose in this study was to develop an automated computer-aided volumetry (CAV) scheme for quantifying pneumothorax in multidetector computed tomography (MDCT) images for pediatric patients and to investigate the imaging parameters that may affect its accuracy. Fifty-eight consecutive pediatric patients (mean age 12 ± 6 years) with pneumothorax who underwent MDCT for evaluation were collected retrospectively for this study. All cases were imaged by a 16- or 64-MDCT scanner with weight-based kilovoltage, low-dose tube current, 1.0-1.5 pitch, 0.6-5.0 mm slice thickness, and a B70f (sharp) or B31f (soft) reconstruction kernel. Sixty-three pneumothoraces ≥1 mL were visually identified in the left (n = 30) and right (n = 33) lungs. Each identified pneumothorax was contoured manually on an Amira workstation V4.1.1 (Mercury Computer Systems, Chelmsford, MA) by two radiologists in consensus. The computerized volumes of the pneumothoraces were determined by application of our CAV scheme. The accuracy of our automated CAV scheme was evaluated by comparison between computerized volumetry and manual volumetry, for the total volume of pneumothoraces in the left and right lungs. The mean difference between the computerized volumetry and the manual volumetry for all 63 pneumothoraces ≥1 mL was 8.2%. For pneumothoraces ≥10 mL, ≥50 mL, and ≥200 mL, the mean differences were 7.7% (n = 57), 7.3% (n = 33), and 6.4% (n = 13), respectively. The correlation coefficient was 0.99 between the computerized volume and the manual volume of pneumothoraces. Bland-Altman analysis showed that computerized volumetry has a mean difference of -5.1% compared to manual volumetry. For all pneumothoraces ≥10 mL, the mean differences for slice thickness ≤1.25 mm, = 1.5 mm, and = 5.0 mm were 6.1% (n = 28), 3.5% (n = 10), and 12.2% (n = 19), respectively. For the two reconstruction kernels, B70f and B31f, the mean differences were 6.3% (n = 42, B70f) and 11.7% (n = 15, B31f

  20. Diagnostic accuracy of state-of-the-art MDCT scanners without gantry tilt in patients with oral and oropharyngeal cancer

    International Nuclear Information System (INIS)

    Bannas, Peter; Habermann, Christian R.; Jung, Caroline; Bley, Thorsten A.; Ittrich, Harald; Adam, Gerhard; Koops, Andreas

    2012-01-01

    Purpose: Current CT-protocols for staging oral and oropharyngeal cancer include primary transversal slices and secondary tilted slices to avoid artifact-producing regions of dental metalwork. Some of the latest MDCT scanners do not allow gantry tilt. Hence, we assessed the relevance of secondary tilted slices in tumor staging. Materials and methods: Scans of a tiltable 64-row MDCT-scanner of 82 patients with oral or oropharyngeal cancer were retrospectively and independently evaluated twice by three readers: once using the primary transversal scans only, and once taking the transversal and secondary tilted scans into account. Tumor diameters and TN-stage were determined with both methods. Artifacts on transversal scans were analyzed using a 3-point-ranking-scale. Results: Image quality was impaired by severe artifacts in 24% of transversal slices of the oral cavity and in 12% of the oropharynx. The three readers detected an average of 57.7 ± 2.1 of 82 tumors (70%) on transversal CT slices. An average of 6.3 ± 0.6 more tumors (8%) were detected when transversal studies were evaluated in conjunction with secondary tilted slices, leading to a significantly (p = 0.0156–0.0313) increased average detection rate of 64.0 ± 2.0 tumors (78%). Moreover, secondary tilted slices led to a correction of underestimated tumor stages in up to six patients (7.3%). Conclusion: Tilted slices that avoid artifact-producing regions of dental metalwork significantly improve the reader's sensitivity and are of incremental value for staging of oral and oropharyngeal cancers.

  1. MDCT arthrography of the wrist: Diagnostic accuracy and indications

    International Nuclear Information System (INIS)

    De Filippo, Massimo; Pogliacomi, Francesco; Bertellini, Annalisa; Araoz, Philip A.; Averna, Raffaele; Sverzellati, Nicola; Ingegnoli, Anna; Corradi, Maurizio; Costantino, Cosimo; Zompatori, Maurizio

    2010-01-01

    Purpose: To evaluate the diagnostic accuracy and indications of arthrography with Multidetector Computed Tomography (arthro-MDCT) of the wrist in patients with absolute or relative contraindications to magnetic resonance imaging (MRI) studies and in patients with periarticular metal implants using diagnostic arthroscopy as the gold standard. Materials and methods: After intra-articular injection of iodixanol and volumetric acquisition, 43 wrists in patients of both genders (18 females, 25 males, age range 32-60 years) were examined with a 16-detector-row CT scanner. Fifteen patients had prior wrist surgery. The patients had arthralgia, degenerative and traumatic arthropathies as well as limited range of motion, but no radiologically detected fractures. All examinations were interpreted by two experienced musculoskeletal radiologists. The findings were compared with arthroscopic findings carried out within 28 days of the CT study. Results: In non-operated and operated wrists the comparison between arthro-MDCT and arthroscopy showed sensitivity, specificity and accuracy ranging between 92% and 94% for triangular fibrocartilage complex (TFCC), between 80% and 100% for intrinsic ligaments located within the proximal carpal compartment, and between 94% and 100% for articular cartilage. Inter-observer agreement between two radiologists, in the evaluation of all types of lesions, was almost perfect (k = 0.96) and statistically significant (p < 0.05). Conclusions: Arthro-MDCT of the wrist provides an accurate diagnosis to identify chondral, fibrocartilaginous and intra-articular ligament lesions in patients who cannot be evaluated by MRI, and in post-surgical patients.

  2. MDCT arthrography of the wrist: Diagnostic accuracy and indications

    Energy Technology Data Exchange (ETDEWEB)

    De Filippo, Massimo [Department of Clinical Sciences, Section of Radiological Sciences, University of Parma, Parma Hospital, Via Gramsci, 14, 43100 Parma (Italy)], E-mail: massimo.defilippo@unipr.it; Pogliacomi, Francesco [Orthopaedics, Traumatology and Functional Rehabilitation Unit, Department of Surgical Sciences, University of Parma, Parma Hospital, Via Gramsci 14, 43100 Parma (Italy); Bertellini, Annalisa [Department of Clinical Sciences, Section of Radiological Sciences, University of Parma, Parma Hospital, Via Gramsci, 14, 43100 Parma (Italy); Araoz, Philip A. [Department of Radiology, Division of Biostatistics, Mayo Clinic, 200 First St SW, Rochester, MN 55905 (United States); Averna, Raffaele; Sverzellati, Nicola; Ingegnoli, Anna [Department of Clinical Sciences, Section of Radiological Sciences, University of Parma, Parma Hospital, Via Gramsci, 14, 43100 Parma (Italy); Corradi, Maurizio; Costantino, Cosimo [Orthopaedics, Traumatology and Functional Rehabilitation Unit, Department of Surgical Sciences, University of Parma, Parma Hospital, Via Gramsci 14, 43100 Parma (Italy); Zompatori, Maurizio [Department of Radiological and Histopathological Sciences, Policlinic S.Orsola-Malpighi, University of Bologna, Via Massarenti 9, 40138 Bologna (Italy)

    2010-04-15

    Purpose: To evaluate the diagnostic accuracy and indications of arthrography with Multidetector Computed Tomography (arthro-MDCT) of the wrist in patients with absolute or relative contraindications to magnetic resonance imaging (MRI) studies and in patients with periarticular metal implants using diagnostic arthroscopy as the gold standard. Materials and methods: After intra-articular injection of iodixanol and volumetric acquisition, 43 wrists in patients of both genders (18 females, 25 males, age range 32-60 years) were examined with a 16-detector-row CT scanner. Fifteen patients had prior wrist surgery. The patients had arthralgia, degenerative and traumatic arthropathies as well as limited range of motion, but no radiologically detected fractures. All examinations were interpreted by two experienced musculoskeletal radiologists. The findings were compared with arthroscopic findings carried out within 28 days of the CT study. Results: In non-operated and operated wrists the comparison between arthro-MDCT and arthroscopy showed sensitivity, specificity and accuracy ranging between 92% and 94% for triangular fibrocartilage complex (TFCC), between 80% and 100% for intrinsic ligaments located within the proximal carpal compartment, and between 94% and 100% for articular cartilage. Inter-observer agreement between two radiologists, in the evaluation of all types of lesions, was almost perfect (k = 0.96) and statistically significant (p < 0.05). Conclusions: Arthro-MDCT of the wrist provides an accurate diagnosis to identify chondral, fibrocartilaginous and intra-articular ligament lesions in patients who cannot be evaluated by MRI, and in post-surgical patients.

  3. MDCT imaging of post interventional liver: a pictorial essay

    International Nuclear Information System (INIS)

    Romano, Stefania; Tortora, Giovanni; Scaglione, Mariano; Lassandro, Francesco; Guidi, Guido; Grassi, Roberto; Romano, Luigia

    2005-01-01

    In this pictorial essay, we consider the post operative MDCT findings after liver resection, transplantation, surgical managed major trauma and radiofrequency ablation of focal lesions. Common complications such as fluid collections, hemorrhage, biloma, vascular disease, hematoma, abscesses will be also considered

  4. Cost-Effectiveness Analysis (CEA) of Intravenous Urography (IVU) and Unenhanced Multidetector Computed Tomography (MDCT) for Initial Investigation of Suspected Acute Ureterolithiasis

    International Nuclear Information System (INIS)

    Eikefjord, E.; Askildsen, J.E.; Roervik, J.

    2008-01-01

    Background: It is important to compare the cost and effectiveness of multidetector computed tomography (MDCT) and intravenous urography (IVU) to determine the most cost-effective alternative for the initial investigation of acute ureterolithiasis. Purpose: To analyze the task-specific variable costs combined with the diagnostic effect of MDCT and IVU for patients with acute flank pain, and to determine which is most cost effective. Material and Methods: 119 patients with acute flank pain suggestive of stone disease (ureterolithiasis) were examined by both MDCT and IVU. Variable costs related to medical equipment, consumption material, equipment control, and personnel were calculated. The diagnostic effect was assessed. Results: The variable costs of MDCT versus IVU were EUR 32 and EUR 117, respectively. This significant difference was mainly due to savings in examination time, higher annual examination frequency, lower material costs, and no use of contrast media. As for diagnostic effect, MDCT proved considerably more accurate in the diagnosis of stone disease than IVU and markedly more accurate concerning differential diagnoses. Conclusion: MDCT had lower differential costs and a higher capacity to determine correctly stone disease and differential diagnoses, as compared to IVU, in patients with acute flank pain. Consequently, MDCT is a dominant alternative to IVU when evaluated exclusively from a cost-effective perspective

  5. Diagnostic accuracy of C-arm CT during selective transcatheter angiography for hepatocellular carcinoma: comparison with intravenous contrast-enhanced, biphasic, dynamic MDCT

    Energy Technology Data Exchange (ETDEWEB)

    Higashihara, Hiroki; Osuga, Keigo; Onishi, Hiromitsu; Nakamoto, Atsushi; Tsuboyama, Takahiro; Maeda, Noboru; Hori, Masatoshi; Kim, Tonsok; Tomiyama, Noriyuki [Osaka University Graduate School of Medicine, Department of Diagnostic and Interventional Radiology, Suita, Osaka (Japan)

    2012-04-15

    This study was aimed to compare the accuracy, sensitivity, and positive predictive value of C-arm CT (CACT) during selective transcatheter angiography with those of multidetector CT (MDCT) in the detection of hepatocellular carcinoma (HCC). In this prospective study, 30 patients (mean age, 73 years) with unresectable HCC were examined with CACT before chemoembolisation. Images of a combination of CACT during arterial portography (CACTAP) and dual-phase CACT during hepatic arteriography (CACTHA) was obtained and images of intravenous contrast-enhanced, biphasic, dynamic, MDCT was also obtained beforehand. Three blinded observers independently reviewed CACT and MDCT. Diagnostic accuracy was evaluated by the alternative free-response receiver operating characteristic (AFROC) method. Sensitivities and positive predictive values (PPV) were analyzed with the paired t-test. In the mean area under the AFROC curve (Az), there was no significant difference between MDCT and CACT (MDCT, mean Az value, 0.83; CACT, 0.85, respectively) (P = 0.32). There was also no significant difference between the two techniques in sensitivity (MDCT, mean 0.65; CACT, 0.60) and PPV (MDCT, mean 0.98; CACT, 0.97) (P = 0.40, P = 0.68, respectively). The diagnostic accuracy of CACT was equivalent to that of biphasic CT in the diagnosis of HCC. (orig.)

  6. Evaluation of portosystemic collaterals by MDCT-MPR imaging for management of hemorrhagic esophageal varices

    International Nuclear Information System (INIS)

    Kodama, Hideaki; Aikata, Hiroshi; Takaki, Shintaro; Azakami, Takahiro; Katamura, Yoshio; Kawaoka, Tomokazu; Hiramatsu, Akira; Waki, Koji; Imamura, Michio; Kawakami, Yoshiiku; Takahashi, Shoichi; Toyota, Naoyuki; Ito, Katsuhide; Chayama, Kazuaki

    2010-01-01

    Objective: To study the correlation between changes in portosystemic collaterals, evaluated by multidetector-row computed tomography imaging using multiplanar reconstruction (MDCT-MPR), and prognosis in patients with hemorrhagic esophageal varices (EV) after endoscopic treatment. Methods: Forty-nine patients with primary hemostasis for variceal bleeding received radical endoscopic treatment: endoscopic injection sclerotherapy (EIS) or endoscopic variceal ligation (EVL). Patients were classified according to the rate of reduction in feeding vessel diameter on MDCT-MPR images, into the narrowing (n = 24) and no-change (n = 25) groups. We evaluated changes in portosystemic collaterals by MDCT-MPR before and after treatment, and determined rebleeding and survival rates. Results: The left gastric and paraesophageal (PEV) veins were recognized as portosystemic collaterals in 100 and 80%, respectively, of patients with EV on MDCT-MPR images. The rebleeding rates at 1, 2, 3, and 5 years after endoscopic treatment were 10, 15, 23, and 23%, respectively, for the narrowing group, and 17, 24, 35, and 67%, respectively, for the no-change group (P = 0.068). Among no-change group, the rebleeding rate in patients with large PEV was significantly lower than that with small PEV (P = 0.027). The rebleeding rate in patients with small PEV of the no-change group was significantly higher than that in the narrowing group (P = 0.018). There was no significant difference in rebleeding rates between the no-change group with a large PEV and narrowing group (P = 0.435). Conclusion: Changes in portosystemic collaterals evaluated by MDCT-MPR imaging correlate with rebleeding rate. Evaluation of portosystemic collaterals in this manner would provide useful information for the management of hemorrhagic EV.

  7. Superwideband Bandwidth Extension Using Normalized MDCT Coefficients for Scalable Speech and Audio Coding

    Directory of Open Access Journals (Sweden)

    Young Han Lee

    2013-01-01

    Full Text Available A bandwidth extension (BWE algorithm from wideband to superwideband (SWB is proposed for a scalable speech/audio codec that uses modified discrete cosine transform (MDCT coefficients as spectral parameters. The superwideband is first split into several subbands that are represented as gain parameters and normalized MDCT coefficients in the proposed BWE algorithm. We then estimate normalized MDCT coefficients of the wideband to be fetched for the superwideband and quantize the fetch indices. After that, we quantize gain parameters by using relative ratios between adjacent subbands. The proposed BWE algorithm is embedded into a standard superwideband codec, the SWB extension of G.729.1 Annex E, and its bitrate and quality are compared with those of the BWE algorithm already employed in the standard superwideband codec. It is shown from the comparison that the proposed BWE algorithm relatively reduces the bitrate by around 19% with better quality, compared to the BWE algorithm in the SWB extension of G.729.1 Annex E.

  8. Incidental finding of both cholecystoduodenal fistula and caecum carcinoma with MDCT imaging

    International Nuclear Information System (INIS)

    Groudeva, V.; Adam, G.; Malla Houech, I-V.; Davidkov, L.; Stoinova, V.

    2015-01-01

    Full text: Bouveret’s syndrome is a rare condition of gastric outlet obstruction, due to the impaction of gallstones in the duodenum. Most commonly it affects women and usually a history of cholelithiasis is present. We present the case of 86 years old female, with complaints of fullness, belching, acids, loss of appetite and weight for a few weeks. The examination revealed soft abdomen, painful palpation and a palpable movable mass in the right lower quadrant. The patient was referred to the imaging department for assessment of the finding. MDCT of the abdomen was carried out on 320 - row Aquillion ONE Toshiba machine, using contrast medium. The aim is to clarifying the accurate managing of the diagnosis of cholecystoduodenal fistula using MDCT. MDCT identified the presence of two independent from one another diseases, characterized by similar complaints. An enhancing mass with irregular borders in the caecal area was visualized. In addition presence of pneumobilia and a communication extending from the gallbladder to the duodenum and calculi in the latter were identified.The findings were consistent with cholecystoduodenal fistula. the patient underwent surgery, right hemicolectomy was performed together with duodenotomy and calculus extraction. Different conditions may present with overlapping symptoms and imaging diagnostic comes in help with the investigation. Since the condition of cholecystoduodenal fistula is associated with high risk of complications and death, it appeals to quick diagnosis and treatment. the use of MDCT in clinical practice as a non-invasive method allows precise identification of the signs of this disease

  9. Renal sympathetic denervation: MDCT evaluation of the renal arteries.

    LENUS (Irish Health Repository)

    Hutchinson, Barry D

    2013-08-01

    Percutaneous transluminal renal sympathetic denervation is a new treatment of refractory systemic hypertension. The purpose of this study was to assess the clinical utility of MDCT to evaluate the anatomic configuration of the renal arteries in the context of renal sympathetic denervation.

  10. In the workup of patients with obscure gastrointestinal bleed, does 64-slice MDCT have a role?

    International Nuclear Information System (INIS)

    Kulkarni, Chinmay; Moorthy, Srikanth; Sreekumar, KP; Rajeshkannan, R; Nazar, PK; Sandya, CJ; Sivasubramanian, S; Ramchandran, PV

    2012-01-01

    The purpose was to prospectively determine the sensitivity of 64-slice MDCT in detecting and diagnosing the cause of obscure gastrointestinal bleed (OGIB). Our study included 50 patients (male 30, female 20) in the age range of 3–82 years (average age: 58.52 years) who were referred to our radiology department as part of their workup for clinically evident gastrointestinal (GI) bleed or as part of workup for anemia (with and without positive fecal occult blood test). All patients underwent conventional upper endoscopy and colonoscopy before undergoing CT scan. Following a noncontrast scan, all patients underwent triple-phase contrast CT scan using a 64-slice CT scan system. The diagnostic performance of 64-slice MDCT was compared to the results of capsule endoscopy, 99m-technetium-labeled red blood cell scintigraphy (99mTc-RBC scintigraphy), digital subtraction angiography, and surgery whenever available. CT scan showed positive findings in 32 of 50 patients. The sensitivity, specificity, positive predictive value, and negative predictive values of MDCT for detection of bleed were 72.2%, 42.8%, 81.2%, and 44.4%, respectively. Capsule endoscopy was done in 15 patients and was positive in 10 patients; it had a sensitivity of 71.4%. Eleven patients had undergone 99mTc-RBC scintigraphy prior to CT scan, and the result was positive in seven patients (sensitivity 70%). Digital subtraction angiography was performed in only eight patients and among them all except one patient showed findings consistent with the lesions detected on MDCT. MDCT is a sensitive and noninvasive tool that allows rapid detection and localization of OGIB. It can be used as the first-line investigation in patients with negative endoscopy and colonoscopy studies. MDCT and capsule endoscopy have complementary roles in the evaluation of OGIB

  11. MR-Imaging of teeth and periodontal apparatus: an experimental study comparing high-resolution MRI with MDCT and CBCT

    International Nuclear Information System (INIS)

    Gaudino, Chiara; Csernus, Reka; Pham, Mirko; Bendszus, Martin; Rohde, Stefan; Cosgarea, Raluca; Kim, Ti-Sun; Heiland, Sabine; Beomonte Zobel, Bruno

    2011-01-01

    The aim of this study was (1) to assess the ability of magnetic resonance imaging (MRI) to visualize dental and periodontal structures and (2) to compare findings with multidetector computed tomography (MDCT) and cone beam CT (CBCT). Four porcine mandibles were examined with (1) 3T-MRI, (2) MDCT and (3) CBCT. Two observers independently reviewed MR, MDCT and CBCT images and assessed image quality of different dental and periodontal structures. To assess quantitatively the accuracy of the different imaging technique, both observers measured burr holes, previously drilled in the mandibles. Dental structures, e.g. teeth roots, pulpa chamber and dentin, were imaged accurately with all imaging sources. Periodontal space and cortical/trabecular bone were better visualized by MRI (p < 0.001). MRI could excellently display the lamina dura, not detectable with MDCT and only inconstant visible with CBCT (p < 0.001). Burr hole measurements were highly precise with all imaging techniques. This experimental study shows the diagnostic feasibility of MRI in visualization of teeth and periodontal anatomy. Detection of periodontal structures was significantly better with MRI than with MDCT or CBCT. Prospective trials have to evaluate further the potential benefit of MRI in a clinical setting. (orig.)

  12. MR-Imaging of teeth and periodontal apparatus: an experimental study comparing high-resolution MRI with MDCT and CBCT

    Energy Technology Data Exchange (ETDEWEB)

    Gaudino, Chiara; Csernus, Reka; Pham, Mirko; Bendszus, Martin; Rohde, Stefan [University Hospital Heidelberg, Department of Neuroradiology, Heidelberg (Germany); Cosgarea, Raluca; Kim, Ti-Sun [University Hospital Heidelberg, Department of Periodontology, Heidelberg (Germany); Heiland, Sabine [University Hospital Heidelberg, Section of Experimental Radiology, Heidelberg (Germany); Beomonte Zobel, Bruno [University Campus Bio-Medico of Rome, Department of Radiology, Interdisciplinary Center for Biomedical Research, Rome (Italy)

    2011-12-15

    The aim of this study was (1) to assess the ability of magnetic resonance imaging (MRI) to visualize dental and periodontal structures and (2) to compare findings with multidetector computed tomography (MDCT) and cone beam CT (CBCT). Four porcine mandibles were examined with (1) 3T-MRI, (2) MDCT and (3) CBCT. Two observers independently reviewed MR, MDCT and CBCT images and assessed image quality of different dental and periodontal structures. To assess quantitatively the accuracy of the different imaging technique, both observers measured burr holes, previously drilled in the mandibles. Dental structures, e.g. teeth roots, pulpa chamber and dentin, were imaged accurately with all imaging sources. Periodontal space and cortical/trabecular bone were better visualized by MRI (p < 0.001). MRI could excellently display the lamina dura, not detectable with MDCT and only inconstant visible with CBCT (p < 0.001). Burr hole measurements were highly precise with all imaging techniques. This experimental study shows the diagnostic feasibility of MRI in visualization of teeth and periodontal anatomy. Detection of periodontal structures was significantly better with MRI than with MDCT or CBCT. Prospective trials have to evaluate further the potential benefit of MRI in a clinical setting. (orig.)

  13. Radiation dose reduction to the male gonads during MDCT: the effectiveness of a lead shield.

    Science.gov (United States)

    Hohl, Christian; Mahnken, Andreas H; Klotz, Ernst; Das, Marco; Stargardt, Achim; Mühlenbruch, Georg; Schmidt, Thorsten; Günther, Rolf W; Wildberger, Joachim E

    2005-01-01

    Our study was designed to quantify the effect of a standard gonad shield on the testicular radiation exposure due to scatter during routine abdominopelvic MDCT. Routine abdominopelvic MDCT was performed in 34 patients with gonadal lead shielding and 32 patients without this shielding; the testes were not exposed to the direct beam during the examination. We estimated the testicular dose administered with thermoluminescent dosimetry, taking into account each patient's body weight and body mass index (BMI). With a 1-mm lead shield, the mean testicular dose was reduced from 2.40 to 0.32 mSv, a reduction of 87%. The difference was found to be statistically significant (p Shielding the male gonads reduces the testicular radiation dose during abdominopelvic MDCT significantly and can be recommended for routine use.

  14. Polyarteritis nodosa: MDCT as a 'One-Stop Shop' Modality for Whole-Body Arterial Evaluation

    International Nuclear Information System (INIS)

    Tsai, W.-L.; Tsai, I-C.; Lee Tain; Hsieh, C.-W.

    2008-01-01

    Polyarteritis nodosa is a rare disease, which is characterized by aneurysm formation and occlusion in the arteries of multiple systems. Due to its extensive involvement, whole-body evaluation is necessary for diagnosis and treatment monitoring. We report a case of polyarteritis nodosa using multidetector-row computed tomography (MDCT) as a 'one-stop shop' modality for whole-body arterial evaluation. With precise protocol design, MDCT can be used as a reliable noninvasive modality providing comprehensive whole-body arterial evaluation.

  15. Demonstration of vascular abnormalities compressing esophagus by MDCT: Special focus on dysphagia lusoria

    Energy Technology Data Exchange (ETDEWEB)

    Alper, Fatih [Department of Radiology, Medical Faculty, Atatuerk University, Erzurum (Turkey)]. E-mail: fatihrad@yahoo.com; Akgun, Metin [Department of Chest Diseases, Medical Faculty, Atatuerk University, Erzurum (Turkey); Kantarci, Mecit [Department of Radiology, Medical Faculty, Atatuerk University, Erzurum (Turkey); Eroglu, Atilla [Department of Thoracic Surgery, Medical Faculty, Atatuerk University, Erzurum (Turkey); Ceyhan, Elvan [Department of Mathematics, College of Arts and Sciences, Koc University, Istanbul (Turkey); Onbas, Omer [Department of Radiology, Medical Faculty, Atatuerk University, Erzurum (Turkey); Duran, Cihan [Department of Radiology, Florence Nightingale Hospital, Istanbul (Turkey); Okur, Adnan [Department of Radiology, Medical Faculty, Atatuerk University, Erzurum (Turkey)

    2006-07-15

    Purpose: Dysphagia lusoria (DL) is described in the literature as difficulty in swallowing caused by vascular abnormalities. The most common cause is an aberrant right subclavian artery (SCA) which passes behind the esophagus and is also called arteria lusoria (AL). Our aim was to demonstrate the use of multidetector computed tomography (MDCT) in the diagnosis of AL, as there is no comprehensive study investigating the role of MDCT in such cases. Material and methods: A total of 38 consecutive patients, comprising of 23 females (61%) and 15 males (39%), who had extrinsic compression were included in the study. These patients are selected from the cases who were admitted due to their gastrointestinal symptoms, such as dysphagia, epigastric pain, chronic nausea, vomiting, etc. The mean age of patients was 40 {+-} 25 years (range 15-65). Following barium esophagogram and then endoscopy performed, MDCT angiography was carried out on the same or the following few days. MDCT sections were examined to determine the following: presence of vascular abnormality; the diameter and angle of that vascular structure; and the compressed area of esophagus. Radiological findings and dysphagia scores were also compared. Results: In each of 15 cases, there was a compression due to vascular abnormality which were all located between the esophagus and the spine. There was an esophageal compression in each of 12 cases, due to right aberrant SCA, in one case due to right superior aortic arch and in two cases due to both right aortic arch and left SCA with Kommerell's diverticulum. The mean diameter and the angle of AL were 16.4 mm and 48.8{sup o}, respectively, and the mean area of pressured esophagus was 194.7 mm{sup 2}. Dysphagia scores of the cases was 1 in thirteen cases and 2 in two cases. However, dysphagia scores were not correlated with these parameters. Conclusions: MDCT angiography is a useful diagnostic tool for evaluation of patients with dysphagia, especially caused by a

  16. Demonstration of vascular abnormalities compressing esophagus by MDCT: Special focus on dysphagia lusoria

    International Nuclear Information System (INIS)

    Alper, Fatih; Akgun, Metin; Kantarci, Mecit; Eroglu, Atilla; Ceyhan, Elvan; Onbas, Omer; Duran, Cihan; Okur, Adnan

    2006-01-01

    Purpose: Dysphagia lusoria (DL) is described in the literature as difficulty in swallowing caused by vascular abnormalities. The most common cause is an aberrant right subclavian artery (SCA) which passes behind the esophagus and is also called arteria lusoria (AL). Our aim was to demonstrate the use of multidetector computed tomography (MDCT) in the diagnosis of AL, as there is no comprehensive study investigating the role of MDCT in such cases. Material and methods: A total of 38 consecutive patients, comprising of 23 females (61%) and 15 males (39%), who had extrinsic compression were included in the study. These patients are selected from the cases who were admitted due to their gastrointestinal symptoms, such as dysphagia, epigastric pain, chronic nausea, vomiting, etc. The mean age of patients was 40 ± 25 years (range 15-65). Following barium esophagogram and then endoscopy performed, MDCT angiography was carried out on the same or the following few days. MDCT sections were examined to determine the following: presence of vascular abnormality; the diameter and angle of that vascular structure; and the compressed area of esophagus. Radiological findings and dysphagia scores were also compared. Results: In each of 15 cases, there was a compression due to vascular abnormality which were all located between the esophagus and the spine. There was an esophageal compression in each of 12 cases, due to right aberrant SCA, in one case due to right superior aortic arch and in two cases due to both right aortic arch and left SCA with Kommerell's diverticulum. The mean diameter and the angle of AL were 16.4 mm and 48.8 o , respectively, and the mean area of pressured esophagus was 194.7 mm 2 . Dysphagia scores of the cases was 1 in thirteen cases and 2 in two cases. However, dysphagia scores were not correlated with these parameters. Conclusions: MDCT angiography is a useful diagnostic tool for evaluation of patients with dysphagia, especially caused by a vascular

  17. Usefulness of multidetector computed tomography (MDCT) for the initial evaluation of multiple blunt trauma of the trunk

    International Nuclear Information System (INIS)

    Hagiwara, Shuichi; Ogino, Takashi; Isaka, Akira; Takahashi, Yuga; Nameki, Tarou; Kagoshima, Kaie; Yamada, Takurou; Ishihara, Kouichi; Iino, Yuichi

    2008-01-01

    Focused assessment with sonography for trauma (FAST) is useful for detecting hemoperitoneum (HE) in trauma patients in the emergency room (ER), but, patients' condition cannot be evaluated adequately by FAST alone. CT is useful for the diagnosis of multiple trauma, but has certain drawbacks. We evaluated the utility of multidetector computed tomography (MDCT) as the initial tool for proper diagnosis and treatment planning of multiple trauma patients. We retrospectively analyzed 128 cases treated in ER of Gunma University Hospital between April 1, 2005 and December 31, 2006, and they were hospital patients were hospitalized with blunt multiple trauma. We analyzed the sensitivity, specificity, and accuracy of FAST, compiled MDCT finding, lifesaving treatment, and outcome. Eight patients were FAST positive, and 7 of the 8 were scanned by MDCT. There were 120 patients were FAST negative patients, 23 of the 120 were MDCT-negative, despite visceral injury, however 9 of the 120 had visceral injury by MDCT findings. Damage control surgery without MDCT was performed in one case, but the patient died after surgery. Six of the patients in the HE-positive group had really HE. One of the 6 died while a waiting surgery, transcatheter arterial embolization (TAE) was performed in three patients, and one person out of the 3 died. The course of the remaining 2 patients was monitored, and they are alive. A patient in the HE-negative group with bladder rupture required surgery. There were 120 patients in the FAST-negative group. One of the 6 patients in the HE-positive subgroup died while a waiting surgery. One patient required chest and pericardial drainage. TAE was performed in 2 patients, and the remaining 6 were monitored and are alive. There were 23 FAST-negative patients patients who had visceral injury. Five of them required chest drainage, one received TAE, 17 were monitored, and all of the 23 are alive. There were 14 cases of pelvic fracture alone, and all of them were FAST

  18. Liver imaging with MDCT and high concentration contrast media

    International Nuclear Information System (INIS)

    Spielmann, Audrey L.

    2003-01-01

    Liver imaging has advanced greatly over the last 10 years with helical CT capability and more recently the addition of multidetector-row CT (MDCT). Multidetector CT technology facilitates imaging at faster speeds with improved image quality and less breathing artifact [Abdom. Imaging 25 (2000) 643]. Exquisite three-dimensional data sets can be obtained with thin collimation providing improved lesion detection, multiplanar imaging, and the ability to perform CT angiography of the liver and mesenteric vessels. New challenges arise with this advance in technology including safety considerations. The radiation dose to the patient has increased with MDCT and this is compounded by the ability to perform multi-phase liver imaging. Furthermore, issues of contrast media administration require reconsideration including optimal timing and rate of administration, the total volume of contrast needed and the ideal iodine concentration of the contrast media. Recently, the use of high concentration contrast media (HCCM) has been explored and study results to date will be reviewed

  19. Noninvasive evaluation of active lower gastrointestinal bleeding: comparison between contrast-enhanced MDCT and 99mTc-labeled RBC scintigraphy.

    Science.gov (United States)

    Zink, Stephen I; Ohki, Stephen K; Stein, Barry; Zambuto, Domenic A; Rosenberg, Ronald J; Choi, Jenny J; Tubbs, Daniel S

    2008-10-01

    The purpose of our study was to compare contrast-enhanced MDCT and (99m)Tc-labeled RBC scanning for the evaluation of active lower gastrointestinal bleeding. Over 17 months, 55 patients (32 men, 23 women; age range, 21-92 years) were evaluated prospectively with contrast-enhanced MDCT using 100 mL of iopromide 300 mg I/mL. Technetium-99m-labeled RBC scans were obtained on 41 of 55 patients and select patients underwent angiography for attempted embolization. Each imaging technique was reviewed in a blinded fashion for sensitivity for detection of active bleeding as well as the active lower gastrointestinal bleeding location. Findings were positive on both examinations in eight patients and negative on both examinations in 20 patients. Findings were positive on contrast-enhanced MDCT and negative on (99m)Tc-labeled RBC in two patients; findings were negative on contrast-enhanced MDCT and positive on (99m)Tc-labeled RBC in 11 patients. Statistics showed significant disagreement, with simple agreement = 68.3%, kappa = 0.341, and p = 0.014. Sixteen of 60 (26.7%) contrast-enhanced MDCT scans were positive prospectively, with all accurately localizing the site of bleeding and identification of the underlying lesion in eight of 16 (50%). Nineteen of 41 (46.3%) (99m)Tc-labeled RBC scans were positive. Eighteen of 41 matched patients went on to angiography. In four of these 18 (22.2%) patients, the site of bleeding was confirmed by angiography, but in 14 of 18 (77.8%), the findings were negative. Contrast-enhanced MDCT and (99m)Tc-labeled RBC scanning show significant disagreement for evaluation of active lower gastrointestinal bleeding. Contrast-enhanced MDCT appears effective for detection and localization in cases of active lower gastrointestinal bleeding in which hemorrhage is active at the time of CT.

  20. Follow-up of coronary artery bypass graft patency: diagnostic efficiency of high-pitch dual-source 256-slice MDCT findings.

    Science.gov (United States)

    Yuceler, Zeyneb; Kantarci, Mecit; Yuce, Ihsan; Kizrak, Yesim; Bayraktutan, Ummugulsum; Ogul, Hayri; Kiris, Adem; Celik, Omer; Pirimoglu, Berhan; Genc, Berhan; Gundogdu, Fuat

    2014-01-01

    Our aim was to evaluate the diagnostic accuracy of 256-slice, high-pitch mode multidetector computed tomography (MDCT) for coronary artery bypass graft (CABG) patency. Eighty-eight patients underwent 256-slice MDCT angiography to evaluate their graft patency after CABG surgery using a prospectively synchronized electrocardiogram in the high-pitch spiral acquisition mode. Effective radiation doses were calculated. We investigated the diagnostic accuracy of high-pitch, low-dose, prospective, electrocardiogram-triggering, dual-source MDCT for CABG patency compared with catheter coronary angiography imaging findings. A total of 215 grafts and 645 vessel segments were analyzed. All graft segments had diagnostic image quality. The proximal and middle graft segments had significantly (P < 0.05) better mean image quality scores (1.18 ± 0.4) than the distal segments (1.31 ± 0.5). Using catheter coronary angiography as the reference standard, high-pitch MDCT had the following sensitivity, specificity, positive predictive value, and negative predictive value of per-segment analysis for detecting graft patency: 97.1%, 99.6%, 94.4%, and 99.8%, respectively. In conclusion, MDCT can be used noninvasively with a lower radiation dose for the assessment of restenosis in CABG patients.

  1. Comprehensive cardiovascular ECG-gated MDCT as a standard diagnostic tool in patients with acute chest pain

    Energy Technology Data Exchange (ETDEWEB)

    Runza, G. [Department of Radiology, University of Palermo (Italy)], E-mail: grunza@sirm.org; La Grutta, L.; Alaimo, V. [Department of Radiology, University of Palermo (Italy); Evola, S. [Department of Cardiology, University of Palermo (Italy); Lo Re, F.; Bartolotta, T.V. [Department of Radiology, University of Palermo (Italy); Cademartiri, F. [Department of Radiology and Cardiology, Erasmus Medical Center, Rotterdam (Netherlands); Department of Radiology and Cardiology, Cardiovascular CT Unit, University Hospital, Parma (Italy); Midiri, M. [Department of Radiology, University of Palermo (Italy)

    2007-10-15

    Acute myocardial infarction, pulmonary embolism, and aortic dissection are diseases associated with acute chest pain and may lead to severe morbidity and mortality. These diseases may not be trivial to diagnose in the settings of emergency room. ECG-gated multi-detector computed tomography (MDCT), already established for the assessment of pulmonary embolism and aortic dissection, provides reliable information regarding the triage of patients with acute coronary syndrome in the emergency room. MDCT recently appeared to be logistically feasible and a promising comprehensive method for the evaluation of cardiac and non-cardiac chest pain in emergency department patients. The possibility to scan the entire thorax visualizing the thoracic aorta, the pulmonary arteries, and the coronary arteries could provide a new approach to the triage of acute chest pain. The inherent advantage of MDCT with cardiac state-of-the-art capabilities is the rapid investigation of the main sources of acute chest pain with a high negative predictive value. Recent studies also reports an advantage in terms of costs. With current evidence, the selection of patients with acute chest pain candidates to MDCT should remain restricted to avoid unjustified risk of ionizing radiation.

  2. Comprehensive cardiovascular ECG-gated MDCT as a standard diagnostic tool in patients with acute chest pain

    International Nuclear Information System (INIS)

    Runza, G.; La Grutta, L.; Alaimo, V.; Evola, S.; Lo Re, F.; Bartolotta, T.V.; Cademartiri, F.; Midiri, M.

    2007-01-01

    Acute myocardial infarction, pulmonary embolism, and aortic dissection are diseases associated with acute chest pain and may lead to severe morbidity and mortality. These diseases may not be trivial to diagnose in the settings of emergency room. ECG-gated multi-detector computed tomography (MDCT), already established for the assessment of pulmonary embolism and aortic dissection, provides reliable information regarding the triage of patients with acute coronary syndrome in the emergency room. MDCT recently appeared to be logistically feasible and a promising comprehensive method for the evaluation of cardiac and non-cardiac chest pain in emergency department patients. The possibility to scan the entire thorax visualizing the thoracic aorta, the pulmonary arteries, and the coronary arteries could provide a new approach to the triage of acute chest pain. The inherent advantage of MDCT with cardiac state-of-the-art capabilities is the rapid investigation of the main sources of acute chest pain with a high negative predictive value. Recent studies also reports an advantage in terms of costs. With current evidence, the selection of patients with acute chest pain candidates to MDCT should remain restricted to avoid unjustified risk of ionizing radiation

  3. Feasibility of opportunistic osteoporosis screening in routine contrast-enhanced multi detector computed tomography (MDCT) using texture analysis.

    Science.gov (United States)

    Mookiah, M R K; Rohrmeier, A; Dieckmeyer, M; Mei, K; Kopp, F K; Noel, P B; Kirschke, J S; Baum, T; Subburaj, K

    2018-04-01

    This study investigated the feasibility of opportunistic osteoporosis screening in routine contrast-enhanced MDCT exams using texture analysis. The results showed an acceptable reproducibility of texture features, and these features could discriminate healthy/osteoporotic fracture cohort with an accuracy of 83%. This aim of this study is to investigate the feasibility of opportunistic osteoporosis screening in routine contrast-enhanced MDCT exams using texture analysis. We performed texture analysis at the spine in routine MDCT exams and investigated the effect of intravenous contrast medium (IVCM) (n = 7), slice thickness (n = 7), the long-term reproducibility (n = 9), and the ability to differentiate healthy/osteoporotic fracture cohort (n = 9 age and gender matched pairs). Eight texture features were extracted using gray level co-occurrence matrix (GLCM). The independent sample t test was used to rank the features of healthy/fracture cohort and classification was performed using support vector machine (SVM). The results revealed significant correlations between texture parameters derived from MDCT scans with and without IVCM (r up to 0.91) slice thickness of 1 mm versus 2 and 3 mm (r up to 0.96) and scan-rescan (r up to 0.59). The performance of the SVM classifier was evaluated using 10-fold cross-validation and revealed an average classification accuracy of 83%. Opportunistic osteoporosis screening at the spine using specific texture parameters (energy, entropy, and homogeneity) and SVM can be performed in routine contrast-enhanced MDCT exams.

  4. Detection of occult vertebral fractures by quantitative assessment of bone marrow attenuation values at MDCT

    Energy Technology Data Exchange (ETDEWEB)

    Henes, Frank Oliver, E-mail: f.henes@uke.de [Department of Diagnostic and Interventional Radiology, Center for Radiology and Endoscopy, University Medical Center Hamburg-Eppendorf, Martinistr. 52, 20246 Hamburg (Germany); Groth, Michael [Department of Diagnostic and Interventional Neuroradiology, Center for Radiology and Endoscopy, University Medical Center Hamburg-Eppendorf, Martinistr. 52, 20246 Hamburg (Germany); Kramer, Harald [Department of Clinical Radiology, Ludwig-Maximilians-University Hospital Munich, Marchioninistr. 15, 81377 Munich (Germany); Department of Radiology, University of Wisconsin – Madison, Clinical Science Center, 600 Highland Avenue, Madison, WI 53792 (United States); Schaefer, Christian [Department of Trauma-, Hand- and Reconstructive Surgery, Spine Center, Center for Surgical Sciences, University Medical Center Hamburg-Eppendorf, Martinistraße 52, 20246 Hamburg (Germany); Regier, Marc; Derlin, Thorsten; Adam, Gerhard; Bannas, Peter [Department of Diagnostic and Interventional Radiology, Center for Radiology and Endoscopy, University Medical Center Hamburg-Eppendorf, Martinistr. 52, 20246 Hamburg (Germany)

    2014-01-15

    Objectives: To determine a cut-off value of Hounsfield attenuation units (HU) at multidetector computed tomography (MDCT) for valid and reliable detection of bone marrow oedema (BME) related to occult vertebral fractures. Methods: 36 patients underwent both MDCT and Magnetic Resonance Imaging (MRI) for evaluation of vertebral fractures of the thoracolumbar spine and were included in this retrospective study. Two readers independently assessed HU values at MDCT in a total of 196 vertebrae. Reliability was assessed by intraclass correlation coefficient and Bland–Altman analysis. For each patient we determined the vertebra with the lowest HU value and calculated the HU-difference to each other vertebral body. HU-differences were subjected to receiver operating characteristic (ROC) curve analysis to determine the diagnostic accuracy for detection of BME as determined by MRI, which served as the reference standard. Results of HU-measurements were compared with standard visual evaluation of MDCT. Results: HU measurements demonstrated a high interrater reliability (ICC = 0.984). ROC curve analysis (AUC = 0.978) exhibited an ideal cut-off value of 29.6 HU for detection of BME associated with vertebral fractures with an accuracy of 97.4% as compared to 93.4% accuracy of visual evaluation. Particularly, HU-measurements increased the sensitivity for detection of vertebral fractures from 78.0% to 92.7% due to the detection of 7 of 9 occult fractures that were missed by visual evaluation alone. Conclusions: Assessing bone marrow density by HU measurements using the cut-off of 29.6 HU is a valid and reliable tool for detection of BME related to occult vertebral fractures in MDCT. The introduced technique may allow more accurate treatment decisions and may make further diagnostic work-up with MRI unnecessary.

  5. Detection of occult vertebral fractures by quantitative assessment of bone marrow attenuation values at MDCT

    International Nuclear Information System (INIS)

    Henes, Frank Oliver; Groth, Michael; Kramer, Harald; Schaefer, Christian; Regier, Marc; Derlin, Thorsten; Adam, Gerhard; Bannas, Peter

    2014-01-01

    Objectives: To determine a cut-off value of Hounsfield attenuation units (HU) at multidetector computed tomography (MDCT) for valid and reliable detection of bone marrow oedema (BME) related to occult vertebral fractures. Methods: 36 patients underwent both MDCT and Magnetic Resonance Imaging (MRI) for evaluation of vertebral fractures of the thoracolumbar spine and were included in this retrospective study. Two readers independently assessed HU values at MDCT in a total of 196 vertebrae. Reliability was assessed by intraclass correlation coefficient and Bland–Altman analysis. For each patient we determined the vertebra with the lowest HU value and calculated the HU-difference to each other vertebral body. HU-differences were subjected to receiver operating characteristic (ROC) curve analysis to determine the diagnostic accuracy for detection of BME as determined by MRI, which served as the reference standard. Results of HU-measurements were compared with standard visual evaluation of MDCT. Results: HU measurements demonstrated a high interrater reliability (ICC = 0.984). ROC curve analysis (AUC = 0.978) exhibited an ideal cut-off value of 29.6 HU for detection of BME associated with vertebral fractures with an accuracy of 97.4% as compared to 93.4% accuracy of visual evaluation. Particularly, HU-measurements increased the sensitivity for detection of vertebral fractures from 78.0% to 92.7% due to the detection of 7 of 9 occult fractures that were missed by visual evaluation alone. Conclusions: Assessing bone marrow density by HU measurements using the cut-off of 29.6 HU is a valid and reliable tool for detection of BME related to occult vertebral fractures in MDCT. The introduced technique may allow more accurate treatment decisions and may make further diagnostic work-up with MRI unnecessary

  6. An intelligent framework for medical image retrieval using MDCT and multi SVM.

    Science.gov (United States)

    Balan, J A Alex Rajju; Rajan, S Edward

    2014-01-01

    Volumes of medical images are rapidly generated in medical field and to manage them effectively has become a great challenge. This paper studies the development of innovative medical image retrieval based on texture features and accuracy. The objective of the paper is to analyze the image retrieval based on diagnosis of healthcare management systems. This paper traces the development of innovative medical image retrieval to estimate both the image texture features and accuracy. The texture features of medical images are extracted using MDCT and multi SVM. Both the theoretical approach and the simulation results revealed interesting observations and they were corroborated using MDCT coefficients and SVM methodology. All attempts to extract the data about the image in response to the query has been computed successfully and perfect image retrieval performance has been obtained. Experimental results on a database of 100 trademark medical images show that an integrated texture feature representation results in 98% of the images being retrieved using MDCT and multi SVM. Thus we have studied a multiclassification technique based on SVM which is prior suitable for medical images. The results show the retrieval accuracy of 98%, 99% for different sets of medical images with respect to the class of image.

  7. Detection of biliary and vascular anatomy in living liver donors: Value of gadobenate dimeglumine enhanced MR and MDCT angiography

    International Nuclear Information System (INIS)

    Artioli, Diana; Tagliabue, Marianna; Aseni, Paolo; Sironi, Sandro; Vanzulli, Angelo

    2010-01-01

    Objective: To evaluate the performance of magnetic resonance (MR) and multidetector computed tomography (MDCT) in the assessment of living donor's vascular and biliary anatomy, having surgical findings as reference standard. Methods: Thirty-two living liver donors underwent MR cholangiography (1.5-T; standard cholangiography pulse sequences and delayed acquisitions after administration of biliary contrast agent) for biliary anatomy evaluation. MDCT (16-row multidetector scanner, multiphase protocol, 3 mm slice thickness) was also performed in all cases for the assessment of vascular anatomy before transplantation. Hepatic veins (<4 mm in diameter) were not considered. MR and MDCT images interpretation was performed by two reviewers by consensus, based on source axial images, multiplanar reformats, and three-dimensional (3D) postprocessing images. Surgical intraoperative findings were used as standard of reference. Results: At surgery, 17 biliary anomalies, 3 portal anomalies, 32 venous and 8 arterial variants were found in the 32 patients. MR correctly identified 15/17 biliary anomalies, with a sensitivity of 88% and a specificity of 93%. MDCT correctly identified 8/8 arterial, 3/3 portal and 29/32 venous variants, with a sensitivity of 100% and 91%, respectively, and a specificity of 100%. Conclusions: MR and MDCT proved to be efficient in evaluating living liver donor's biliary and vascular anatomy.

  8. Detection of biliary and vascular anatomy in living liver donors: Value of gadobenate dimeglumine enhanced MR and MDCT angiography

    Energy Technology Data Exchange (ETDEWEB)

    Artioli, Diana, E-mail: diansadiana@gmail.com [Ospedale Niguarda Ca' Granda, Piazza Ospedale Maggiore 3, 20162 Milano (Italy); Tagliabue, Marianna; Aseni, Paolo; Sironi, Sandro; Vanzulli, Angelo [Ospedale Niguarda Ca' Granda, Piazza Ospedale Maggiore 3, 20162 Milano (Italy)

    2010-11-15

    Objective: To evaluate the performance of magnetic resonance (MR) and multidetector computed tomography (MDCT) in the assessment of living donor's vascular and biliary anatomy, having surgical findings as reference standard. Methods: Thirty-two living liver donors underwent MR cholangiography (1.5-T; standard cholangiography pulse sequences and delayed acquisitions after administration of biliary contrast agent) for biliary anatomy evaluation. MDCT (16-row multidetector scanner, multiphase protocol, 3 mm slice thickness) was also performed in all cases for the assessment of vascular anatomy before transplantation. Hepatic veins (<4 mm in diameter) were not considered. MR and MDCT images interpretation was performed by two reviewers by consensus, based on source axial images, multiplanar reformats, and three-dimensional (3D) postprocessing images. Surgical intraoperative findings were used as standard of reference. Results: At surgery, 17 biliary anomalies, 3 portal anomalies, 32 venous and 8 arterial variants were found in the 32 patients. MR correctly identified 15/17 biliary anomalies, with a sensitivity of 88% and a specificity of 93%. MDCT correctly identified 8/8 arterial, 3/3 portal and 29/32 venous variants, with a sensitivity of 100% and 91%, respectively, and a specificity of 100%. Conclusions: MR and MDCT proved to be efficient in evaluating living liver donor's biliary and vascular anatomy.

  9. Hepatosplenic volumetric assessment at MDCT for staging liver fibrosis

    Energy Technology Data Exchange (ETDEWEB)

    Pickhardt, Perry J.; Malecki, Kyle; Hunt, Oliver F.; Beaumont, Claire; Kloke, John; Ziemlewicz, Timothy J.; Lubner, Meghan G. [University of Wisconsin School of Medicine and Public Health, Department of Radiology, Madison, WI (United States)

    2017-07-15

    To investigate hepatosplenic volumetry at MDCT for non-invasive prediction of hepatic fibrosis. Hepatosplenic volume analysis in 624 patients (mean age, 48.8 years; 311 M/313 F) at MDCT was performed using dedicated software and compared against pathological fibrosis stage (F0 = 374; F1 = 48; F2 = 40; F3 = 65; F4 = 97). The liver segmental volume ratio (LSVR) was defined by Couinaud segments I-III over segments IV-VIII. All pre-cirrhotic fibrosis stages (METAVIR F1-F3) were based on liver biopsy within 1 year of MDCT. LSVR and total splenic volumes increased with stage of fibrosis, with mean(±SD) values of: F0: 0.26 ± 0.06 and 215.1 ± 88.5 mm{sup 3}; F1: 0.25 ± 0.08 and 294.8 ± 153.4 mm{sup 3}; F2: 0.331 ± 0.12 and 291.6 ± 197.1 mm{sup 3}; F3: 0.39 ± 0.15 and 509.6 ± 402.6 mm{sup 3}; F4: 0.56 ± 0.30 and 790.7 ± 450.3 mm{sup 3}, respectively. Total hepatic volumes showed poor discrimination (F0: 1674 ± 320 mm{sup 3}; F4: 1631 ± 691 mm{sup 3}). For discriminating advanced fibrosis (≥F3), the ROC AUC values for LSVR, total liver volume, splenic volume and LSVR/spleen combined were 0.863, 0.506, 0.890 and 0.947, respectively. Relative changes in segmental liver volumes and total splenic volume allow for non-invasive staging of hepatic fibrosis, whereas total liver volume is a poor predictor. Unlike liver biopsy or elastography, these CT volumetric biomarkers can be obtained retrospectively on routine scans obtained for other indications. (orig.)

  10. Utility of Postmortem Autopsy via Whole-Body Imaging: Initial Observations Comparing MDCT and 3.0T MRI Findings with Autopsy Findings

    International Nuclear Information System (INIS)

    Cha, Jang Gyu; Kim, Dong Hun; Paik, Sang Hyun

    2010-01-01

    We prospectively compared whole-body multidetector computed tomography (MDCT) and 3.0T magnetic resonance (MR) images with autopsy findings. Five cadavers were subjected to whole-body, 16- channel MDCT and 3.0T MR imaging within two hours before an autopsy. A radiologist classified the MDCT and 3.0T MRI findings into major and minor findings, which were compared with autopsy findings. Most of the imaging findings, pertaining to head and neck, heart and vascular, chest, abdomen, spine, and musculoskeletal lesions, corresponded to autopsy findings. The causes of death that were determined on the bases of MDCT and 3.0T MRI findings were consistent with the autopsy findings in four of five cases. CT was useful in diagnosing fatal hemorrhage and pneumothorax, as well as determining the shapes and characteristics of the fractures and the direction of external force. MRI was effective in evaluating and tracing the route of a metallic object, soft tissue lesions, chronicity of hemorrhage, and bone bruises. A postmortem MDCT combined with MRI is a potentially powerful tool, providing noninvasive and objective measurements for forensic investigations

  11. Evaluation of radiation doses from MDCT-imaging in otolaryngology

    International Nuclear Information System (INIS)

    Yamauchi-Kawaura, C.; Fujii, K.; Aoyama, T.; Yamauchi, M.; Koyama, S.

    2009-01-01

    The purpose of this study was to clarify patient doses in the current otolaryngological multi-detector row computed tomography (MDCT) examinations. Patient doses were measured with an in-phantom dosimetry system which was composed of 48 photodiode dosemeters embedded within an anthropomorphic phantom. Organ and effective doses were evaluated according to the International Commission on Radiological Protection Publication 103. In neck CT, doses for salivary glands and for thyroid were high, 7.6-29.9 and 13.4-60.3 mGy, respectively. In sinus CT, brain and lens doses were high, 7.6-24.6 and 10.6-32.0 mGy, respectively, and in inner ear CT, lens dose was 8.0-35.3 mGy. Effective doses were 1.8-6.6 mSv in neck CT, 0.5-0.9 mSv in sinus CT and 0.3-0.6 mSv in inner ear CT. The present dose data would be used to estimate radiation risks for patients undergoing otolaryngological MDCT examinations. (authors)

  12. Prevalence of 'high-riding' superior pericardial recesses on thin-section 16-MDCT scans

    Energy Technology Data Exchange (ETDEWEB)

    Basile, Antonio [Department of Radiology and Interventional Radiology, Ospedale Ferrarotto, via Citelli, 8 95124 Catania (Italy)]. E-mail: antodoc@yahoo.com; Bisceglie, Paola [Department of Radiology and Interventional Radiology, Ospedale Ferrarotto, via Citelli, 8 95124 Catania (Italy); Giulietti, Giorgio [Department of Radiology and Interventional Radiology, Ospedale Ferrarotto, via Citelli, 8 95124 Catania (Italy); Calcara, Giacomo [Department of Radiology and Interventional Radiology, Ospedale Ferrarotto, via Citelli, 8 95124 Catania (Italy); Figuera, Michele [Department of Radiology, Ospedale Vittorio Emanuele, Via Plebiscito 628, 95124 Catania (Italy); Mundo, Elena [Department of Radiology and Interventional Radiology, Ospedale Ferrarotto, via Citelli, 8 95124 Catania (Italy); Granata, Antonio [Department of Nephrology, Ospedale Vittorio Emanuele, Via Plebiscito 628, 95124 Catania (Italy); Runza, Giuseppe [Department of Radiology, Policlinico Universitario, Via del Vespro 129, 90127 Palermo (Italy); Privitera, Carmelo [Department of Radiology, Ospedale Vittorio Emanuele, Via Plebiscito 628, 95124 Catania (Italy); Privitera, Giambattista [Department of Radiology and Interventional Radiology, Ospedale Ferrarotto, via Citelli, 8 95124 Catania (Italy); Patti, Maria Teresa [Department of Radiology and Interventional Radiology, Ospedale Ferrarotto, via Citelli, 8 95124 Catania (Italy)

    2006-08-15

    Objective: The aim of this study was to evaluate the prevalence of 'high-riding' superior pericardial recess (HRSPR) on thin-section (1 mm) 16-multidetector computed tomography (MDCT) scans. Materials and methods: Three hundred and fourteen consecutive chest CT scans obtained with a thin-section 16 MDCT were retrospectively evaluated. The prevalence and characteristic of HRSPR were analyzed. Results: HRSPR was depicted in 21 patients (11 men and 10 women) (6.6%) who ranged in age from 28 to 72 years (mean age, 57 years). The extended recesses were rounded/oval shaped in five patients and triangular, spindle, half moon or irregular shaped in the other 16 patients. Conclusion: Our data suggest as HRSPRs are more frequently and better depicted on thinsection MDCT scans, and this improves the capability to distinguish this superior extension of the superior aortic recess from abnormal findings such as lymphadenopathy, cystic lesions, and aortic dissection.

  13. Comparison of hepatic MDCT, MRI, and DSA to explant pathology for the detection and treatment planning of hepatocellular carcinoma

    Directory of Open Access Journals (Sweden)

    Lauren M. Ladd

    2016-12-01

    Full Text Available Background/Aims The diagnosis and treatment plan for hepatocellular carcinoma (HCC can be made from radiologic imaging. However, lesion detection may vary depending on the imaging modality. This study aims to evaluate the sensitivities of hepatic multidetector computed tomography (MDCT, magnetic resonance imaging (MRI, and digital subtraction angiography (DSA in the detection of HCC and the consequent management impact on potential liver transplant patients. Methods One hundred and sixteen HCC lesions were analyzed in 41 patients who received an orthotopic liver transplant (OLT. All of the patients underwent pretransplantation hepatic DSA, MDCT, and/or MRI. The imaging results were independently reviewed retrospectively in a blinded fashion by two interventional and two abdominal radiologists. The liver explant pathology was used as the gold standard for assessing each imaging modality. Results The sensitivity for overall HCC detection was higher for cross-sectional imaging using MRI (51.5%, 95% confidence interval [CI]=36.2-58.4% and MDCT (49.8%, 95% CI=43.7-55.9% than for DSA (41.7%, 95% CI=36.2-47.3% (P=0.05. The difference in false-positive rate was not statistically significant between MRI (22%, MDCT (29%, and DSA (29% (P=0.67. The sensitivity was significantly higher for detecting right lobe lesions than left lobe lesions for all modalities (MRI: 56.1% vs. 43.1%, MDCT: 55.0% vs. 42.0%, and DSA: 46.9% vs. 33.9%; all P<0.01. The sensitivities of the three imaging modalities were also higher for lesions ≥2 cm vs. <2 cm (MRI: 73.4% vs. 32.7%, MDCT: 66.9% vs. 33.8%, and DSA: 62.2% vs. 24.1%; all P<0.01. The interobserver correlation was rated as very good to excellent. Conclusion The sensitivity for detecting HCC is higher for MRI and MDCT than for DSA, and so cross-sectional imaging modalities should be used to evaluate OLT candidacy.

  14. The value of MDCT in diagnosis of splenic artery aneurysms

    International Nuclear Information System (INIS)

    Sun Cong; Liu Cheng; Wang Ximing; Wang Daoping

    2008-01-01

    Objective: To evaluate the clinical value of multiple detector computed tomography (MDCT) in the diagnosis and planning the treatment of splenic aneurysms. Methods: Eight cases with splenic artery aneurysms (SAA) were retrospectively reviewed. Sixty four-slice spiral CT scans were performed. Intravenous contrast material was injected at 4 ml/s, and arterial and venous phase images were obtained. Subsequently, arterial phase images were analyzed and made for CT angiography. The diagnosis was made by using axial and reconstructive images. All of the patients were also performed Doppler color echocardiography. Results: All patients showed splenic artery and splenic artery aneurysms clearly with CT arterial phase images. Among them, six patients had splenic artery aneurysms, one had giant splenic artery aneurysms (GSAA) and one had splenic artery pseudoaneurysms. Ultrasound examination only diagnosed six of them. Conclusion: MDCT is a noninvasive and valuable method in diagnosis of splenic artery aneurysms and has high value in determination of treatment plan

  15. The value of MDCT in diagnosis of splenic artery aneurysms

    Energy Technology Data Exchange (ETDEWEB)

    Sun Cong [Shandong University, Shandong Provincial Medical Imaging Institute, Road jing-wu No. 324, Jinan, Shandong 250021 (China)], E-mail: suncong03@163.com; Liu Cheng; Wang Ximing; Wang Daoping [Shandong University, Shandong Provincial Medical Imaging Institute, Road jing-wu No. 324, Jinan, Shandong 250021 (China)

    2008-03-15

    Objective: To evaluate the clinical value of multiple detector computed tomography (MDCT) in the diagnosis and planning the treatment of splenic aneurysms. Methods: Eight cases with splenic artery aneurysms (SAA) were retrospectively reviewed. Sixty four-slice spiral CT scans were performed. Intravenous contrast material was injected at 4 ml/s, and arterial and venous phase images were obtained. Subsequently, arterial phase images were analyzed and made for CT angiography. The diagnosis was made by using axial and reconstructive images. All of the patients were also performed Doppler color echocardiography. Results: All patients showed splenic artery and splenic artery aneurysms clearly with CT arterial phase images. Among them, six patients had splenic artery aneurysms, one had giant splenic artery aneurysms (GSAA) and one had splenic artery pseudoaneurysms. Ultrasound examination only diagnosed six of them. Conclusion: MDCT is a noninvasive and valuable method in diagnosis of splenic artery aneurysms and has high value in determination of treatment plan.

  16. Low dose MDCT of the wrist-An ex vivo approach

    International Nuclear Information System (INIS)

    Bolte, H.; Sattler, E.-M.; Jahnke, T.; Roeger, I.; Biederer, J.; Jochens, A.; Dischinger, J.; Schuenke, M.; Sedlmair, M.; Heller, M.

    2011-01-01

    The primary objective of this study was to evaluate, if in multidetector computed tomography (MDCT) of the wrist a good image quality can be maintained while radiation dose is substantially reduced. In a second approach one solely parameter change that allows for the best trade-off between dose reduction and image quality should be identified. Twenty wrist specimens were examined with a 16-slice MDCT in different parameter combinations: 120 and 100 kV, 100, 70 and 40 electronic mA s, pitch factor 0.9 and 1.5. Images were reconstructed in four standard planes (slice thickness 1.0 mm, increment 0.5 mm, hard kernel) resulting into a total number of 960 images. Two observers evaluated image quality in a blinded and randomized consensus scheme. Detail quality of corticalis, spongiosa, articular surface and soft tissues was graded according to a four-point scale (1 = excellent, 2 = good, 3 = sufficient, and 4 = poor). The scan protocol with the best trade-off between radiation exposure and image quality had a parameter constellation of 100 kV, 70 electronic mA s (78 effective mA s) and a pitch of 0.9 (DLP 63 mGy cm). This represented a dose reduction of 55%. A solely decrease of voltage lead to a dose reduction of 36% without any loss of image quality. An increase of the pitch factor to 1.5 and a decrease from 70 to 40 mA s caused the most distinct impairment of image quality. In MDCT of the wrist good image quality could be maintained while radiation dose was considerably reduced. A reduction of voltage offers the best result for a solely parameter change.

  17. Calcium score of small coronary calcifications on multidetector computed tomography

    DEFF Research Database (Denmark)

    Groen, J M; Kofoed, K F; Zacho, M

    2013-01-01

    Multi detector computed tomography (MDCT) underestimates the coronary calcium score as compared to electron beam tomography (EBT). Therefore clinical risk stratification based on MDCT calcium scoring may be inaccurate. The aim of this study was to assess the feasibility of a new phantom which...

  18. Current role of MDCT in the diagnosis of coronary artery disease (2011). A clinical guideline of the Austrian Societies of Cardiology and Radiology

    International Nuclear Information System (INIS)

    Hergan, K.; Globits, S.; Loewe, C.

    2011-01-01

    The clinical guideline of the Austrian Societies for Cardiology and Radiology on the actual role of MDCT in the diagnosis of coronary artery diseases includes the following issues: CT calcium scoring; CT angiography (CTA) of the coronaries; actually recommended application of MDCR; generally inappropriate use of the technique for specific patients; radiation exposure; structural and organizational framework.

  19. MDCT assessment of tracheomalacia in symptomatic infants with mediastinal aortic vascular anomalies: preliminary technical experience

    International Nuclear Information System (INIS)

    Lee, Edward Y.; Mason, Keira P.; Zurakowski, David; Waltz, David A.; Ralph, Amy; Riaz, Farhana; Boiselle, Phillip M.

    2008-01-01

    Mediastinal aortic vascular anomalies are relatively common causes of extrinsic central airway narrowing in infants with respiratory symptoms. Surgical correction of mediastinal aortic vascular anomalies alone might not adequately treat airway symptoms if extrinsic narrowing is accompanied by intrinsic tracheomalacia (TM), a condition that escapes detection on routine end-inspiratory imaging. Paired inspiratory-expiratory multidetector CT (MDCT) has the potential to facilitate early diagnosis and timely management of TM in symptomatic infants with mediastinal aortic vascular anomalies. To assess the technical feasibility of paired inspiratory-expiratory MDCT for evaluating TM among symptomatic infants with mediastinal aortic vascular anomalies. The study group consisted of five consecutive symptomatic infants (four male, one female; mean age 4.1 months, age range 2 weeks to 6 months) with mediastinal aortic vascular anomalies who were referred for paired inspiratory-expiratory MDCT during a 22-month period. CT angiography was concurrently performed during the end-inspiration phase of the study. Two pediatric radiologists in consensus reviewed all CT images in a randomized and blinded fashion. The end-inspiration and end-expiration CT images were reviewed for the presence and severity of tracheal narrowing. TM was defined as ≥50% reduction in tracheal cross-sectional luminal area between end-inspiration and end-expiration. The presence of TM was compared to the bronchoscopy results when available (n = 4). Paired inspiratory-expiratory MDCT was technically successful in all five patients. Mediastinal aortic vascular anomalies included a right aortic arch with an aberrant left subclavian artery (n = 2), innominate artery compression (n = 2), and a left aortic arch with an aberrant right subclavian artery (n 1). Three (60%) of the five patients demonstrated focal TM at the level of mediastinal aortic vascular anomalies. The CT results were concordant with the results

  20. Spectrum of imaging findings on MDCT enterography in patients with small bowel tuberculosis

    International Nuclear Information System (INIS)

    Kalra, N.; Agrawal, P.; Mittal, V.; Kochhar, R.; Gupta, V.; Nada, R.; Singh, R.; Khandelwal, N.

    2014-01-01

    Abdominal tuberculosis (TB) is the sixth most common extrapulmonary site of involvement. The sites of involvement in abdominal tuberculosis, in descending order of frequency, are lymph nodes, genitourinary tract, peritoneal cavity, and gastrointestinal tract. The radiological armamentarium for evaluating tuberculosis of the small bowel (SBTB) includes barium studies (small bowel follow-through, SBFT), CT (multidetector CT, CT enterography, and CT enteroclysis), ultrasound (sonoenteroclysis), and magnetic resonance imaging (MRI; enterography and enteroclysis). In this review, we illustrate the abnormalities at MDCT enterography in 20 consecutive patients with SB TB and also describe extraluminal findings in these patients. MDCT enterography allows non-invasive good-quality assessment of well-distended bowel loops and the adjacent soft tissues. It displays the thickness and enhancement of the entire bowel wall in all three planes and allows examination of all bowel loops, especially the ileal loops, which are mostly superimposed. The terminal ileum and ileocaecal junction are the most common sites of small bowel involvement in intestinal TB. The most common abnormality is short-segment strictures with symmetrical concentric mural thickening and homogeneous mural enhancement. Other findings include lymphadenopathy, ascites, enteroliths, peritoneal thickening, and enhancement. In conclusion, MDCT enterography is a comprehensive technique for the evaluation of SB TB

  1. MDCT evaluation of potential living renal donor, prior to laparoscopic donor nephrectomy: What the transplant surgeon wants to know?

    International Nuclear Information System (INIS)

    Ghonge, Nitin P; Gadanayak, Satyabrat; Rajakumari, Vijaya

    2014-01-01

    As Laparoscopic Donor Nephrectomy (LDN) offers several advantages for the donor such as lesser post-operative pain, fewer cosmetic concerns and faster recovery time, there is growing global trend towards LDN as compared to open nephrectomy. Comprehensive pre-LDN donor evaluation includes assessment of renal morphology including pelvi-calyceal and vascular system. Apart from donor selection, evaluation of the regional anatomy allows precise surgical planning. Due to limited visualization during laparoscopic renal harvesting, detailed pre-transplant evaluation of regional anatomy, including the renal venous anatomy is of utmost importance. MDCT is the modality of choice for pre-LDN evaluation of potential renal donors. Apart from appropriate scan protocol and post-processing methods, detailed understanding of surgical techniques is essential for the Radiologist for accurate image interpretation during pre-LDN MDCT evaluation of potential renal donors. This review article describes MDCT evaluation of potential living renal donor, prior to LDN with emphasis on scan protocol, post-processing methods and image interpretation. The article laid special emphasis on surgical perspectives of pre-LDN MDCT evaluation and addresses important points which transplant surgeons want to know

  2. Nuclear power plant cost underestimation: mechanisms and corrections

    International Nuclear Information System (INIS)

    Meyer, M.B.

    1984-01-01

    Criticisms of inaccurate nuclear power plant cost estimates have commonly focused upon what factors have caused actual costs to increase and not upon the engineering cost estimate methodology itself. This article describes two major sources of cost underestimation and suggests corrections for each which can be applied while retaining the traditional engineering methodology in general

  3. Enhanced multidetector-row computed tomography (MDCT) in the diagnosis of acute appendicitis and its severity

    International Nuclear Information System (INIS)

    Miki, Tesshou; Ogata, Seiji; Uto, Mitsunobu; Nakazono, Toshihiro; Urata, Miyuki; Ishibe, Ryouhei; Shinyama, Shin; Nakajo, Masayuki

    2005-01-01

    The purpose of this study was to examine the accuracy of enhanced multidetector-row computed tomography (MDCT) in diagnosing acute appendicitis and its severity. Contrast-enhanced MD-CT 3.5 mm thick images of 23 control patients (A), and 64 patients with surgically proven acute appendicitis including 8 catarrhal (B), 28 phiegmonous (C), and 28 gangrenous (D) appendicitis patients were respectively analyzed. The number of observed major computed tomography (CT) findings for each patient group were as follows: enlarged (≥6 mm in maximum diameter) appendix (A: 5, B: 8, C: 28, D: 28), enhancement of the appendiceal wall; hyper (A: 3, B: 8, C: 27, D: 20), iso (A: 15, B: 0, C: 1, D: 2), hypo (A-C: 0, D: 4), and patched (A-C: 0, D: 2) enhancement, appendicolith (A, B: 0, C: 7, D: 13), dirty fat sign (A: 3, B: 1, C: 21, D: 28), localized ascites (A: 2, B: 0, C: 2, D: 11), and abscess formation (A-C: 0, D: 5). From the combinations of these findings, we could differentiate acute appendicitis from the control normal appendix with an accuracy of 99% and could diagnose the severity of acute appendicitis with accuracies of 92% for catarrhal appendicitis, 84% for phlegmonous appendicitis, and 92% for gangrenous appendicitis. We could also visually reconstruct the entire forms and positions of the appendices from the successive CT findings because of the high-resolution thin-slice MDCT images. MDCT is highly accurate in the diagnosis of acute appendicitis and its severity. (author)

  4. 64-MDCT angiography of blunt vascular injuries of the neck.

    Science.gov (United States)

    Chokshi, Falgun H; Munera, Felipe; Rivas, Luis A; Henry, Robert P; Quencer, Robert M

    2011-03-01

    CT angiography (CTA) using 64-MDCT enables timely evaluation of injuries associated with blunt neck trauma. The purpose of this article is to familiarize the reader with the most frequent CTA signs of blunt vascular injury. CTA is a valuable tool to detect blunt vascular injuries, especially using its multiplanar and 3D reconstruction capabilities.

  5. MDCT-Guided Transthoracic Needle Aspiration Biopsy of the Lung Using the Transscapular Approach

    International Nuclear Information System (INIS)

    Rossi, Umberto G.; Seitun, Sara; Ferro, Carlo

    2011-01-01

    The purpose of this study is to report our preliminary experience using MDCT-guided percutaneous transthoracic needle aspiration biopsy using the transscapular approach in the upper posterolateral lung nodules, an area that it is difficult or hazardous to reach with the conventional approach. Five patients underwent CT-guided percutaneous transthoracic needle aspiration biopsy of the lung via the transscapular approach. A coaxial needle technique was used in all patients. Biopsy was successful in all patients. No major complications were encountered. One patient developed a minimal pneumothorax next to the lesion immediately after biopsy, which resolved spontaneously. MDCT-guided percutaneous transthoracic needle aspiration biopsy of the lung via the transscapular approach is an effective and safe procedure that reduces the risk of pneumothorax in selected patients.

  6. Coronary artery bypass grafts: assessment of graft patency and native coronary artery lesions using 16-slice MDCT

    Energy Technology Data Exchange (ETDEWEB)

    Stauder, Norbert I.; Drosch, Tanja; Claussen, Claus D.; Kopp, Andreas F. [Eberhard-Karls-University, Department of Diagnostic Radiology, Tuebingen (Germany); Kuettner, Axel [Friedrich-Alexander-University, Department of Diagnostic Radiology, Erlangen (Germany); Schroeder, Stephen; Beck, Torsten [Eberhard-Karls-University, Department of Internal Medicine, Division Cardiology, Tuebingen (Germany); Stauder, Heidrun [Eberhard-Karls-University, Department of Thoracic and Cardiovascular Surgery, Tuebingen (Germany); Blumenstock, Gunnar [Eberhard-Karls-University, Department of Medical Information Processing, Tuebingen (Germany)

    2006-11-15

    The objective of this study was to evaluate the accuracy of electrocardiography (ECG)-gated 16-slice multidetector-row computed tomography (MDCT) in detection of stenosis of bypass grafts and native coronary arteries in patients who have undergone coronary artery bypass grafting (CABG). ECG-gated contrast-enhanced MDCT using 12 x 0.75-mm collimation was performed in 20 patients with recurrent angina 4.75 years after undergoing CABG. A total of 50 grafts, 16 arterial and 34 venous, were examined. All graft and coronary segments were evaluated for stenosis in comparison with conventional coronary angiography (CCA). Among the 80 arterial graft segments, 62 could be assessed (77.5%). Sensitivity, specificity, and positive and negative predictive values for stenosis were 96.2%, 97.2%, 96.2%, and 97.2%, respectively. In a total of 180 venous graft segments, 167 could be assessed. Sensitivity, specificity, and positive and negative predictive values for stenosis were 98.5%, 93.9%, 91.8%, and 98.9%, respectively. MDCT could assess 179 of 260 native coronary artery segments (68.8%).Sensitivity, specificity, and positive and negative predictive values for stenosis were 92.1%, 76.9%, 87.5%, and 84.7%, respectively. Sixteen-slice MDCT provides excellent image quality and diagnostic accuracy in detection of graft and coronary artery lesions in patients with suspected graft dysfunction. (orig.)

  7. Osteoid osteoma and osteoid osteoma-mimicking lesions: biopsy findings, distinctive MDCT features and treatment by radiofrequency ablation

    Energy Technology Data Exchange (ETDEWEB)

    Becce, Fabio [Centre Hospitalier Universitaire Vaudois, Department of Diagnostic and Interventional Radiology, Lausanne (Switzerland); Universite Paris Descartes, Department of Radiology B, Hopital Cochin, AP-HP, Paris (France); Theumann, Nicolas [Centre Hospitalier Universitaire Vaudois, Department of Diagnostic and Interventional Radiology, Lausanne (Switzerland); Rochette, Antoine; Campagna, Raphael; Drape, Jean-Luc; Feydy, Antoine [Universite Paris Descartes, Department of Radiology B, Hopital Cochin, AP-HP, Paris (France); Larousserie, Frederique [Universite Paris Descartes, Department of Anatomic Pathology, Hopital Cochin, AP-HP, Paris (France); Cherix, Stephane; Mouhsine, Elyazid [Centre Hospitalier Universitaire Vaudois, Department of Orthopaedic and Traumatologic Surgery, Lausanne (Switzerland); Guillou, Louis [University Institute of Pathology, Centre Hospitalier Universitaire Vaudois, Lausanne (Switzerland); Anract, Philippe [Universite Paris Descartes, Department of Orthopaedic Surgery, Hopital Cochin, AP-HP, Paris (France)

    2010-10-15

    To report the biopsy findings of osteoid osteoma (OO) and OO-mimicking lesions, assess their distinctive multidetector computed tomography (MDCT) features and evaluate treatment by radiofrequency ablation (RFA). In this multicentric retrospective study, 80 patients (54 male, 26 female, mean age 24.1 years, range 5-48) with presumed (clinical and MDCT features) OO were treated by percutaneous RFA between May 2002 and June 2009. Per-procedural biopsies were always performed. The following MDCT features were assessed: skeletal distribution and location within the bone, size, central calcification, surrounding osteosclerosis and periosteal reaction. Clinical success of RFA was evaluated. Histopathological diagnoses were: 54 inconclusive biopsies, 16 OO, 10 OO-mimicking lesions (5 chronic osteomyelitis, 3 chondroblastoma, 1 eosinophilic granuloma, 1 fibrous dysplasia). OO-mimicking lesions were significantly greater in size (p = 0.001) and presented non-significant trends towards medullary location (p = 0.246), moderate surrounding osteosclerosis (p = 0.189) and less periosteal reaction (p = 0.197), compared with OO. Primary success for ablation of OO-mimicking lesions was 100% at 1 month, 85.7% at 6 and 12 months, and 66.7% at 24 months. Secondary success was 100%. Larger size, medullary location, less surrounding osteosclerosis and periosteal reaction on MDCT may help differentiate OO-mimicking lesions from OO. OO-mimicking lesions are safely and successfully treated by RFA. (orig.)

  8. Osteoid osteoma and osteoid osteoma-mimicking lesions: biopsy findings, distinctive MDCT features and treatment by radiofrequency ablation

    International Nuclear Information System (INIS)

    Becce, Fabio; Theumann, Nicolas; Rochette, Antoine; Campagna, Raphael; Drape, Jean-Luc; Feydy, Antoine; Larousserie, Frederique; Cherix, Stephane; Mouhsine, Elyazid; Guillou, Louis; Anract, Philippe

    2010-01-01

    To report the biopsy findings of osteoid osteoma (OO) and OO-mimicking lesions, assess their distinctive multidetector computed tomography (MDCT) features and evaluate treatment by radiofrequency ablation (RFA). In this multicentric retrospective study, 80 patients (54 male, 26 female, mean age 24.1 years, range 5-48) with presumed (clinical and MDCT features) OO were treated by percutaneous RFA between May 2002 and June 2009. Per-procedural biopsies were always performed. The following MDCT features were assessed: skeletal distribution and location within the bone, size, central calcification, surrounding osteosclerosis and periosteal reaction. Clinical success of RFA was evaluated. Histopathological diagnoses were: 54 inconclusive biopsies, 16 OO, 10 OO-mimicking lesions (5 chronic osteomyelitis, 3 chondroblastoma, 1 eosinophilic granuloma, 1 fibrous dysplasia). OO-mimicking lesions were significantly greater in size (p = 0.001) and presented non-significant trends towards medullary location (p = 0.246), moderate surrounding osteosclerosis (p = 0.189) and less periosteal reaction (p = 0.197), compared with OO. Primary success for ablation of OO-mimicking lesions was 100% at 1 month, 85.7% at 6 and 12 months, and 66.7% at 24 months. Secondary success was 100%. Larger size, medullary location, less surrounding osteosclerosis and periosteal reaction on MDCT may help differentiate OO-mimicking lesions from OO. OO-mimicking lesions are safely and successfully treated by RFA. (orig.)

  9. Multi-detector computed tomography (MDCT imaging of cardiovascular effects of pulmonary embolism: What the radiologists need to know

    Directory of Open Access Journals (Sweden)

    Mohamed Aboul-fotouh E. Mourad

    2017-09-01

    Full Text Available Background: Patients with pulmonary embolism have high mortality and morbidity rate due to right heart failure and circulatory collapse leading to sudden death. Multi-detector computed tomography MDCT can efficiently evaluate the cardiovascular factors related to pulmonary embolism. Objectives: To evaluate the diagnostic accuracy of multi-detector computed tomography (MDCT in differentiation of between sever and non-severe pulmonary embolism groups depending on the associated cardiovascular parameters and create a simple reporting system. Patients & methods: Prospective study contained 145 patients diagnosed clinically pulmonary embolism. All patients were examined by combined electrocardiographically gated computed tomography pulmonary angiography-computed tomography venography (ECG-CTPA-CTV using certain imaging criteria in a systematic manner. Results: Our study revealed 95 and 55 non-severe and severe pulmonary embolism groups respectively. Many cardiovascular parameters related to pulmonary embolism shows significant p value and can differentiate between sever and non-severe pulmonary embolism patients include pulmonary artery diameter, intraventricular septum flattening, bowing, superior vena cava and Azygos vein diameters, right and left ventricular diameters. Conclusion: Multi-detector computed tomography (MDCT can be valuable to assess the severity of pulmonary embolism using the related cardiovascular parameters and leading the management strategy aim for best outcome. Keywords: Pulmonary embolism, MDCT, Cardiovascular, Computed tomography venography

  10. MDCT evaluation of potential living renal donor, prior to laparoscopic donor nephrectomy: What the transplant surgeon wants to know?

    Directory of Open Access Journals (Sweden)

    Nitin P Ghonge

    2014-01-01

    Full Text Available As Laparoscopic Donor Nephrectomy (LDN offers several advantages for the donor such as lesser post-operative pain, fewer cosmetic concerns and faster recovery time, there is growing global trend towards LDN as compared to open nephrectomy. Comprehensive pre-LDN donor evaluation includes assessment of renal morphology including pelvi-calyceal and vascular system. Apart from donor selection, evaluation of the regional anatomy allows precise surgical planning. Due to limited visualization during laparoscopic renal harvesting, detailed pre-transplant evaluation of regional anatomy, including the renal venous anatomy is of utmost importance. MDCT is the modality of choice for pre-LDN evaluation of potential renal donors. Apart from appropriate scan protocol and post-processing methods, detailed understanding of surgical techniques is essential for the Radiologist for accurate image interpretation during pre-LDN MDCT evaluation of potential renal donors. This review article describes MDCT evaluation of potential living renal donor, prior to LDN with emphasis on scan protocol, post-processing methods and image interpretation. The article laid special emphasis on surgical perspectives of pre-LDN MDCT evaluation and addresses important points which transplant surgeons want to know.

  11. Comparison of capability of dynamic O2-enhanced MRI and quantitative thin-section MDCT to assess COPD in smokers

    International Nuclear Information System (INIS)

    Ohno, Yoshiharu; Koyama, Hisanobu; Yoshikawa, Takeshi; Matsumoto, Keiko; Aoyama, Nobukazu; Onishi, Yumiko; Takenaka, Daisuke; Matsumoto, Sumiaki; Nishimura, Yoshihiro; Sugimura, Kazuro

    2012-01-01

    Purpose: The purpose of this study was to directly and prospectively compare the capability of dynamic O 2 -enhanced MRI and quantitatively assessed thin-section MDCT to assess smokers’ COPD in a large prospective cohort. Materials and methods: The GOLD criteria for smokers were used to classify 187 smokers into four clinical stage groups as follows: smokers without COPD (n = 56) and with mild (n = 54), moderate (n = 52) and severe or very severe COPD (n = 24). All smokers underwent dynamic O 2 -enhanced MRI, MDCT and pulmonary function tests. Mean relative enhancement ratio and mean wash-in time on MRI and CT-based functional lung volume (CT-based FLV) as well as the ratio of airway wall area to total airway area on MDCT were computationally calculated. Then, all indexes were significantly correlated with functional parameters. To determine the efficacy of all indexes for clinical stage classification, the indexes for the four clinical groups were statistically compared by using Tukey's honestly significant difference multiple comparison test. Results: All indexes had significant correlations with functional parameters (p 2 -enhanced MRI for assessment of COPD in smokers is potentially as efficacious as quantitatively assessed thin-section MDCT.

  12. Paediatric multidetector CT optimisation training: a survey of common scanning procedures and the resultant dose reduction associated with paediatric MDCT investigations in Australia

    International Nuclear Information System (INIS)

    Wallace, Anthony; Sibelle, Kimberly; Stanley, Martin; Budd, Ray; Goergen, Stacey; Heggie, John

    2008-01-01

    The growing recognition of the increased risk of stochastic injury to paediatric patients from multidetector CT (MDCT) investigations prompted a survey sponsored by Royal Australian and New Zealand College of Radiology (RANZCR), Austin Health and Monash University to initiate a national paediatric dosimetry review for some of the most common investigations undertaken in MDCT paediatric practice. The survey forms included a data sheet requiring acquisition protocol parameters and a phantom graphic sheet requiring the marking of the inferior and superior acquisition margins. Survey forms were supplied for each of 13 common MDCT acquisitions to be tested. Response data was input into CT-Expo Version 1.5.1., a CT dosimetry calculation engine, to determine dose length product (DLP (mGy.cm)) and effective dose (ED (mSv)). Initial survey data was collected, calculated, blinded and collated into various presentations that were given at a MDCT optimisation seminar in November, 2006. All sites were re-surveyed in May 2007 and doses calculated. Initial survey data showed a range of dose efficiencies spread across the surveyed sites. A measure of the initial spread of DLP values per procedure ranged from a minimum of less than 2 for a head-trauma acquisition (372 - 520 mGy.cm) to 14 for a chest-trauma acquisition (28 - 388 mGy.cm). Results of the 2nd survey strongly indicate that the application of optimisation training to paediatric MDCT scanning can produce significant dose savings by the application of simple dose saving strategies. Many protocols demonstrated dose reductions of greater than 50% with significant reductions in both the maximum and minimum values of calculated DLP and ED. The development of a survey-training-resurvey model of MDCT optimisation has proven to be a successful strategy for paediatric MDCT dose reduction in Australia. (author)

  13. Normal appendix in adults: MDCT findings about the location, thickness and the presence or absence of intraluminal gas

    International Nuclear Information System (INIS)

    Oh, Kyoung Jin; Cho, June Sik; Shin, Kyung Sook; Kim, Ha Young; Lim, Sae Kyung; Ohm, Joon Young; Yoon, Chung Dae; Shin, Byung Seok

    2006-01-01

    We wanted to examine the usefulness of multi-detector CT (MDCT) with multiplanar reformations for evaluating the location, thickness and the presence or absence of intraluminal gas in the normal appendix of adults. From December 2004 to June 2005, we evaluated normal appendices in 427 consecutive adult patients who were scanned with 16-slice MDCT. All these patients had no clinical findings of appendicitis. There were 251 men and 176 women. The age range was 19-84 years (mean age: 55 years). The contrast-enhanced MDCT scans during the portal phase were obtained with 0.75 mm detector collimation and they were reviewed with using the multiplanar reconstruction images (3 mm section thickness). The MDCT images of normal appendices on a PACS monitor were retrospectively analyzed. We analyzed the location, thickness and the presence or absence of intraluminal gas by consensus of two abdominal radiologists. The positions of normal appendices were classified as type I (postileal and medial paracecal), type II (subcecal), type III (retrocecal and retrocolic or laterocolic), type IV (preileal and medical colic) and type V (lower pelvic cavity). The five types of appendiceal locations were as follows: type I (n = 187; 44%), type II (n 78; 18%), type III (n = 92, 22%), type IV (n = 39; 9%) and type V (n = 31; 7%). The appendiceal tips in 29 cases (7%) were unusually located in the right subhepatic space, the small bowel mesentery and the right adnexa. The mean thickness of 427 appendices was 5.8 ± 0.9 mm (range: 3.8-9.2 mm). The appendiceal mean thickness was 5.9 ± 0.9 mm in men and 5.7 ± 0.9 mm in women (ρ < 0.05). 384 (90%) of 427 appendices had intraluminal gas and 43 (10%) had no intraluminal gas, and their mean thickness was 5.9 mm (range: 3.8-9.2 mm) and 5.3 mm (3.8-7.3 mm), respectively (ρ < 0.05). MDCT with multiplanar reformations was useful for evaluating the location, thickness and the presence or absence of intraluminal gas in normal appendix of adults. These

  14. Multi detector computed tomography (MDCT) of the aortic root; ECG-gated verses non-ECG-gated examinations

    International Nuclear Information System (INIS)

    Kristiansen, Joanna; Guenther, Anne; Aalokken, Trond Mogens; Andersen, Rune

    2011-01-01

    Purpose: Motion artifacts may degrade a conventional CT examination of the ascending aorta and hinder accurate diagnosis. We quantitatively compared retrospectively electrocardiographic (ECG) -gated multi detector computed tomography (MDCT) with non-ECG-gated MDCT in order to demonstrate whether or not one of the methods should be preferred. Method: The study included seventeen patients with surgically reconstructed aortic root and reimplanted coronary arteries. All patients had undergone both non-gated MDCT and retrospectively ECG-gated MDCT employing a stringently modulated tube current with single phase image reconstruction. The incidence of motion artifacts in the left main coronary artery (LM), proximal right coronary artery (RCA), and aortic root and ascending aorta were rated using a four point scale. The effective dose for each scan was calculated and normalized to a 15 cm scan length. Statistical analysis of motion artifacts and radiation dose was performed using Wilcoxon matched pairs signed rank sum test. Results: A significant reduction in motion artifacts was found in all three vessels in images from the retrospectively ECG-gated scans (LM: P = 0.005, RCA: P = 0.015, aorta: P = 0.003). The mean normalized effective radiation dose was 3.69 mSv (±1.03) for the non-ECG-gated scans and 16.37 mSv (±2.53) for the ECG-gated scans. Conclusion: Retrospective ECG-gating with single phase reconstruction significantly reduces the incidence of motion artifacts in the aortic root and the proximal portion of the coronary arteries but at the expense of a fourfold increase in radiation dose.

  15. MDCT in the diagnosis of small-bowel obstruction by a retained ...

    African Journals Online (AJOL)

    assessment of complications such as abscess formation, fistula. MDCT in the diagnosis of small-bowel obstruction by a retained surgical swab. M. Bindapersad, M.B. Ch.B., F.C.Rad. (Diag.) N. Govender, M.B. Ch.B. Department of Radiology, Chris Hani Baragwanath Hospital and Faculty of Health Sciences, University of the ...

  16. Fractures of the thoracic spine in patients with minor trauma: Comparison of diagnostic accuracy and dose of biplane radiography and MDCT

    Energy Technology Data Exchange (ETDEWEB)

    Karul, M., E-mail: m.karul@uke.de [Department of Diagnostic and Interventional Radiology, University Medical Center Hamburg-Eppendorf, Hamburg (Germany); Bannas, P.; Schoennagel, B.P.; Hoffmann, A.; Wedegaertner, U.; Adam, G.; Yamamura, J. [Department of Diagnostic and Interventional Radiology, University Medical Center Hamburg-Eppendorf, Hamburg (Germany)

    2013-08-15

    Objectives: To investigate the accuracy of biplane radiography in the detection of fractures of the thoracic spine in patients with minor trauma using multidetector computed tomography (MDCT) as the reference and to compare the dose of both techniques. Methods: 107 consecutive trauma patients with suspected fractures of the thoracic spine on physical examination were included. All had undergone biplane radiography first, followed by a MDCT scan between October 2008 and October 2012. A fourfold table was used for the classification of the screening test results. Both the Chi-square test (χ{sup 2}) and the mean dose-length product (DLP) were used to compare the diagnostic methods. Results: MDCT revealed 77 fractures in 65/107 patients (60.7%). Biplane radiography was true positive in 32/107 patients (29.9%), false positive in 19/107 patients (17.8%), true negative in 23/107 (21.5%) and false negative in 33/107 patients (30.8%), showing a sensitivity of 49.2%, a specificity of 54.7%, a positive predictive value (PPV) of 62.7%, a negative predictive value (NPV) of 41.1%, and an accuracy of 51.4%. The presence of a fracture on biplane radiography was highly statistical significant, if this was simultaneously proven by MDCT (χ{sup 2} = 7.6; p = 0.01). None of the fractures missed on biplane radiography was unstable. The mean DLP on biplane radiography was 14.5 mGy cm (range 1.9–97.8) and on MDCT 374.6 mGy cm (range 80.2–871). Conclusions: The sensitivity and the specificity of biplane radiography in the diagnosis of fractures of the thoracic spine in patients with minor trauma are low. Considering the wide availability of MDCT that is usually necessary for taking significant therapeutic steps, the indication for biplane radiography should be very restrictive.

  17. Clinical significance of pneumatosis intestinalis - correlation of MDCT-findings with treatment and outcome

    Energy Technology Data Exchange (ETDEWEB)

    Treyaud, Marc-Olivier; Duran, Rafael; Knebel, Jean-Francois; Meuli, Reto A.; Schmidt, Sabine [Lausanne University Hospital, Department of Diagnostic and Interventional Radiology, Lausanne (Switzerland); Zins, Marc [Fondation Hopital St Joseph, Department of Radiology, Paris (France)

    2017-01-15

    To evaluate the clinical significance of pneumatosis intestinalis (PI) including the influence on treatment and outcome. Two radiologists jointly reviewed MDCT-examinations of 149 consecutive emergency patients (53 women, mean age 64, range 21-95) with PI of the stomach (n = 4), small (n = 68) and/or large bowel (n = 96). PI extension, distribution and possibly associated porto-mesenteric venous gas (PMVG) were correlated with other MDCT-findings, risk factors, clinical management, laboratory, histopathology, final diagnosis and outcome. The most frequent cause of PI was intestinal ischemia (n = 80,53.7 %), followed by infection (n = 18,12.1 %), obstructive (n = 12,8.1 %) and non-obstructive (n = 10,6.7 %) bowel dilatation, unknown aetiologies (n = 8,5.4 %), drugs (n = 8,5.4 %), inflammation (n = 7,4.7 %), and others (n = 6,4 %). Neither PI distribution nor extension significantly correlated with underlying ischemia. Overall mortality was 41.6 % (n = 62), mostly related to intestinal ischemia (p = 0.003). Associated PMVG significantly correlated with underlying ischemia (p = 0.009), as did the anatomical distribution of PMVG (p = 0.015). Decreased mural contrast-enhancement was the only other MDCT-feature significantly associated with ischemia (p p < 0.001). Elevated white blood count significantly correlated with ischemia (p = 0.03). In emergency patients, ischemia remains the most common aetiology of PI, showing the highest mortality. PI with associated PMVG is an alerting sign. PI together with decreased mural contrast-enhancement indicates underlying ischemia. (orig.)

  18. Computer-aided liver volumetry: performance of a fully-automated, prototype post-processing solution for whole-organ and lobar segmentation based on MDCT imaging.

    Science.gov (United States)

    Fananapazir, Ghaneh; Bashir, Mustafa R; Marin, Daniele; Boll, Daniel T

    2015-06-01

    To evaluate the performance of a prototype, fully-automated post-processing solution for whole-liver and lobar segmentation based on MDCT datasets. A polymer liver phantom was used to assess accuracy of post-processing applications comparing phantom volumes determined via Archimedes' principle with MDCT segmented datasets. For the IRB-approved, HIPAA-compliant study, 25 patients were enrolled. Volumetry performance compared the manual approach with the automated prototype, assessing intraobserver variability, and interclass correlation for whole-organ and lobar segmentation using ANOVA comparison. Fidelity of segmentation was evaluated qualitatively. Phantom volume was 1581.0 ± 44.7 mL, manually segmented datasets estimated 1628.0 ± 47.8 mL, representing a mean overestimation of 3.0%, automatically segmented datasets estimated 1601.9 ± 0 mL, representing a mean overestimation of 1.3%. Whole-liver and segmental volumetry demonstrated no significant intraobserver variability for neither manual nor automated measurements. For whole-liver volumetry, automated measurement repetitions resulted in identical values; reproducible whole-organ volumetry was also achieved with manual segmentation, p(ANOVA) 0.98. For lobar volumetry, automated segmentation improved reproducibility over manual approach, without significant measurement differences for either methodology, p(ANOVA) 0.95-0.99. Whole-organ and lobar segmentation results from manual and automated segmentation showed no significant differences, p(ANOVA) 0.96-1.00. Assessment of segmentation fidelity found that segments I-IV/VI showed greater segmentation inaccuracies compared to the remaining right hepatic lobe segments. Automated whole-liver segmentation showed non-inferiority of fully-automated whole-liver segmentation compared to manual approaches with improved reproducibility and post-processing duration; automated dual-seed lobar segmentation showed slight tendencies for underestimating the right hepatic lobe

  19. High-pitch computed tomography of the lung in pediatric patients. An intraindividual comparison of image quality and radiation dose to conventional 64-MDCT

    Energy Technology Data Exchange (ETDEWEB)

    Tsiflikas, I.; Thomas, C.; Ketelsen, D.; Claussen, C.D.; Schaefer, J.F. [University Hospital of Tuebingen (Germany). Diagnostic and Interventional Radiology; Seitz, G.; Warmann, S. [University Hospital of Tuebingen (Germany). Pediatric Surgery

    2014-06-15

    Purpose: The aim of this study was to investigate frequencies of typical artifacts in low-dose pediatric lung examinations using high-pitch computed tomography (HPCT) compared to MDCT, and to estimate the effective radiation dose (E{sub eff}). Materials and Methods: Institutional review board approval for this retrospective study was obtained. 35 patients (17 boys, 18 girls; mean age 112 ± 69 months) were included and underwent MDCT and follow-up scan by HPCT or vice versa (mean follow-up time 87 days), using the same tube voltage and current. The total artifact score (0-8) was defined as the sum of artifacts arising from movement, breathing or pulsation of the heart or pulmonary vessels (0 - no; 1 - moderate; 2 - severe artifacts). E{sub eff} was estimated according to the European Guidelines on Quality Criteria for Multislice Computed Tomography. The Mann-Whitney U test was used to analyze differences between the patient groups. The Spearman's rank correlation coefficient was used for correlation of ordinal variables. Results: The scan time was significantly lower for HPCT compared to MDCT (0.72 ± 0.13 s vs. 3.65 ± 0.81s; p < 0.0001). In 28 of 35 (80 %) HPCT examinations no artifacts were visible, whereas in MDCT artifacts occurred in all examinations. The frequency of pulsation artifacts and breathing artifacts was higher in MDCT compared to HPCT (100% vs. 17% and 31% vs. 6%). The total artifact score significantly correlated with the patient's age in MDCT (r=-0.42; p=0.01), but not in HPCT (r=-0.32; p=0.07). The estimated E{sub eff} was significantly lower in HPCT than in MDCT (1.29±0.31 vs. 1.47±0.37 mSv; p < 0.0001). Conclusion: Our study indicates that the use of HPCT has advantages for pediatric lung imaging with a reduction of breathing and pulsation artifacts. Moreover, the estimated E{sub eff} was lower. In addition, examinations can be performed without sedation or breath-hold without losing image quality. (orig.)

  20. Contribution of multi-detector row CT (MDCT) to decision making in the management of patients with small bowel obstruction or ileus

    International Nuclear Information System (INIS)

    Osada, Hisato; Watanabe, Wataru; Okada, Taketomo

    2007-01-01

    We retrospectively evaluated the contribution of multi-detector row CT (MDCT) to patient management decisions in 62 patients with small bowel obstruction or ileus. The sensitivity and specificity of MDCT diagnosis of small bowel obstruction with strangulation or closed loop were 78.9% (15/19) and 93.0% (40/43), respectively. In 19 patients with small bowel obstruction with strangulation or closed loop, the median interval between CT examination and the commencement of surgery was significantly longer in misdiagnosed patients than in those correctly diagnosed (43.3 vs. 4.5 hours, p<0.05). Only two patients displayed severe physical signs that required urgent surgical treatment. Our results suggest that MDCT plays a key role in the management of patients with small bowel obstruction. (author)

  1. Correlation of 64 row MDCT, echocardiography and cardiac catheterization angiography in assessment of pulmonary arterial anatomy in children with cyanotic congenital heart disease

    International Nuclear Information System (INIS)

    Chandrashekhar, Guruprasadh; Sodhi, Kushaljit Singh; Saxena, Akshay Kumar; Rohit, Manoj Kumar; Khandelwal, Niranjan

    2012-01-01

    Objective: To study the correlation of low-dose 64-row multi-detector computed tomography (MDCT) with echocardiography and cardiac catheterization angiography (CCA) in the assessment of pulmonary arterial anatomy in children with cyanotic congenital heart disease (CCHD). Materials and methods: This prospective study included 105 children (74 males, 31 females) with CCHD, in the age group of 2 months to 20 years, who underwent 64-row MDCT examination (low-dose CT protocol), echocardiography and CCA for the assessment of pulmonary arteries, including visualization, presence of confluence, stenosis and collaterals. Statistical analysis was performed using the non-parametric statistical analysis test to evaluate the concordance or discordance between echocardiography, MDCT and CCA. Results: 64-row MDCT detected significantly more main and branch pulmonary arteries, patent pulmonary confluences, and more cases of pulmonary artery stenosis. CCA detected more major aorto-pulmonary collaterals than MDCT, whereas echocardiography failed to identify these major aorto-pulmonary collaterals. The effective CT radiation dose to patients less than 2 years of age was in the range of 0.7–2.5 mSv, where as the dose in patients more than 2 years of age ranged from that of 2.1 to 4.2 mSv, which is much less than the radiation dose reported in cardiac catheterization angiography. Conclusion: In cases where cardiac MRI cannot be performed, or is not sufficiently informative, low-dose 64-row MDCT correlates well with CCA and can provide adequate information about pulmonary arterial anatomy in children with cyanotic congenital heart disease, and can replace invasive cardiac catheterization angiography with markedly reduced radiation dosage to the patient.

  2. Multidetector CT (MD-CT) in the diagnosis of uncertain open globe injuries

    Energy Technology Data Exchange (ETDEWEB)

    Hoffstetter, P.; Schreyer, A.G.; Jung, E.M.; Heiss, P.; Zorger, N. [Inst. fuer Roentgendiagnostik, Universitaetsklinikum Regensburg (Germany); Schreyer, C.I.; Framme, C. [Klink und Poliklinik fuer Augenheilkunde, Universitaetsklinikum Regensburg (Germany)

    2010-02-15

    Purpose: To evaluate the significance of multislice CT for the diagnosis of uncertain penetrating globe injuries. Materials and Methods: Based on a retrospective chart review between 2002 and 2007, we identified 59 patients presenting with severe ocular trauma with uncertain rupture of the globe due to massive subconjunctival and/or anterior chamber hemorrhage. The IOP (intraocular pressure) was within normal range in all patients. High resolution multidetector CT (MD-CT) scans (16 slice scans) with axial and coronar reconstructions were performed in all patients. The affected eye was examined for signs of penetrating injury such as abnormal eye shape, scleral irregularities, lens dislocation or intravitreal hemorrhages. Four experienced radiologists read the CT scans independently. Beside the diagnosis, the relevant morphological criteria and the optimal plane orientation (axial or coronar) were specified. The sensitivity, specificity, and negative and positive predictive value were calculated. Additionally the interobserver variability was determined by applying the Cohen's kappa test. Surgical sclera inspections were performed in all cases as a standard of reference. The evaluations of the CT examination were compared with the surgery reports. Results: 59 patients were evaluated (42 men, 17 women). The mean age was 29 years (range 7-91). In 17 patients a rupture of the globe was diagnosed during surgery. 12 of these 17 penetrating injuries (70.6%) were classified correctly by MDCT, 5 of the 17 (29.4%) were not detectable. 42 patients did not have an open globe injury. 41 of these patients were diagnosed correctly negative by MDCT, and one patient was classified false positive. This results in a sensitivity of 70% with a specificity of 98%. There was high inter-rater agreement with kappa values between 0.89-0.96. Most discrepancies were caused by wrong negative findings. The most frequent morphologic criteria for open globe injury were the deformation (n

  3. MDCT Findings of Traumatic Adrenal Injury in Children

    International Nuclear Information System (INIS)

    Choi, Seung Joon; Kim, Jee Eun; Ryu, Il; Kim, Jin Joo; Choi, Hye Young

    2011-01-01

    We wanted to evaluate the MDCT findings and concomitant injuries of traumatic adrenal injury in children. Among 375 children who had undergone a MDCT scan for abdominal trauma during the recent five years at our institution, 27 children who had revealed adrenal injury on their CT scan were included in the study. We retrospectively evaluated the causes of the trauma, the patterns of adrenal injury, the associated CT findings and the concomitant injuries of the other organs in the abdomen. We identified 27 children (7.5%) (17 boys and 10 girls, mean age: 9.9 years, range: 2-18 years) with adrenal injury. The causes of adrenal injury were a traffic accident for 20 patients (74%), falls for four patients (15%) and blunt trauma for three patients (11%). The right adrenal gland was injured in 20 patients (74%), while the left adrenal gland was injured in three patients and bilateral involvement was noted in four patients. The patterns of adrenal injury were round or oval shaped hematoma in 23 lesions (74%), irregular hemorrhage with obliterating the gland in six lesions (19%) and active extravasation of contrast material from the adrenal region in two lesions (7%). Concomitant injuries were noted in 22 patients (81%), including 15 patients with liver laceration (56%), 11 patients with lung contusion (41%) and nine patients with renal injury (33%). The frequency of adrenal injury was 7.5%. The right adrenal gland was more frequently involved. Concomitant organ injury was noted 81% of the patients and the most frequently involved organ was the liver (56%)

  4. MDCT of acute pancreatitis: Intraindividual comparison of single-phase versus dual-phase MDCT for initial assessment of acute pancreatitis using different CT scoring systems

    Energy Technology Data Exchange (ETDEWEB)

    Avanesov, Maxim, E-mail: m.avanesov@uke.de [Department of Diagnostic and Interventional Radiology and Nuclear Medicine, University Medical Center Hamburg-Eppendorf, Hamburg (Germany); Weinrich, Julius M.; Kraus, Thomas [Department of Diagnostic and Interventional Radiology and Nuclear Medicine, University Medical Center Hamburg-Eppendorf, Hamburg (Germany); Derlin, Thorsten [Department of Nuclear Medicine, Hannover Medical School (Germany); Adam, Gerhard; Yamamura, Jin [Department of Diagnostic and Interventional Radiology and Nuclear Medicine, University Medical Center Hamburg-Eppendorf, Hamburg (Germany); Karul, Murat [Department of Diagnostic and Interventional Radiology, Marienkrankenhaus Hamburg (Germany)

    2016-11-15

    Objectives: The purpose of the retrospective study was to evaluate the additional value of dual-phase multidetector computed tomography (MDCT) protocols over a single-phase protocol on initial MDCT in patients with acute pancreatitis using three CT-based pancreatitis severity scores with regard to radiation dose. Methods: In this retrospective, IRB approved study MDCT was performed in 102 consecutive patients (73 males; 55years, IQR48–64) with acute pancreatitis. Inclusion criteria were CT findings of interstitial edematous pancreatitis (IP) or necrotizing pancreatitis (NP) and a contrast-enhanced dual-phase (arterial phase and portal-venous phase) abdominal CT performed at ≥72 h after onset of symptoms. The severity of pancreatic and extrapancreatic changes was independently assessed by 2 observers using 3 validated CT-based scoring systems (CTSI, mCTSI, EPIC). All scores were applied to arterial phase and portal venous phase scans and compared to score results of portal venous phase scans, assessed ≥14 days after initial evaluation. For effective dose estimation, volume CT dose index (CTDIvol) and dose length product (DLP) were recorded in all examinations. Results: In neither of the CT severity scores a significant difference was observed after application of a dual-phase protocol compared with a single-phase protocol (IP: CTSI: 2.7 vs. 2.5, p = 0.25; mCTSI: 4.0 vs. 4.0, p = 0.10; EPIC: 2.0 vs. 2.0, p = 0.41; NP: CTSI: 8.0 vs. 7.0, p = 0.64; mCTSI: 8.0 vs. 8.0, p = 0.10; EPIC: 3.0 vs. 3.0, p = 0.06). The application of a single-phase CT protocol was associated with a median effective dose reduction of 36% (mean dose reduction 31%) compared to a dual-phase CT scan. Conclusions: An initial dual-phase abdominal CT after ≥72 h after onset of symptoms of acute pancreatitis was not superior to a single-phase protocol for evaluation of the severity of pancreatic and extrapancreatic changes. However, the effective radiation dose may be reduced by 36% using a

  5. Differentiation between tuberculosis and lymphoma in mediastinal lymph nodes: Evaluation with contrast-enhanced MDCT

    International Nuclear Information System (INIS)

    Tang, S.-S.; Yang, Z.-G.; Deng, W.; Shao, H.; Chen, J.; Wen, L.-Y.

    2012-01-01

    Aim: To determine the specific imaging criteria on contrast-enhanced multidetector computed tomography (MDCT) for differentiating between tuberculosis and lymphoma in mediastinal lymph nodes. Materials and methods: The anatomical distribution and enhancement patterns of mediastinal lymph nodes on contrast-enhanced MDCT were reviewed in 37 patients with tuberculosis and 54 patients with lymphoma. Of the patients with lymphoma, 18 had Hodgkin's disease and 36 had non-Hodgkin's lymphoma. Results: Region 10R was involved more often in tuberculosis than in Hodgkin's disease and non-Hodgkin's lymphoma. Region 6 had a higher tendency to be affected in Hodgkin's disease and non-Hodgkin's lymphoma compared with tuberculosis. Tuberculosis showed peripheral enhancement in 78% of cases, frequently with a multilocular appearance, compared to Hodgkin's disease and non-Hodgkin's lymphoma, which showed peripheral enhancement in only 6 and 3% of cases, respectively. Homogeneous enhancement was more commonly seen in lymphoma (83% for Hodgkin's disease, and 83% for non-Hodgkin's lymphoma) than in tuberculosis (8%). In the determination of tuberculosis, results showed that when a peripheral enhancement pattern was seen, sensitivity was 78%, specificity was 96%, and accuracy was 89%. In the determination of lymphoma, results showed that when a homogeneous enhancement pattern was seen, sensitivity was 83%, specificity was 92%, and accuracy was 87%. Conclusion: The findings of the present study indicate that specific anatomical distribution and enhancement patterns of lymphadenopathy shown on contrast-enhanced MDCT can be useful in differentiating tuberculosis from lymphoma of mediastinal lymph nodes.

  6. Understanding chest radiographic anatomy with MDCT reformations

    Energy Technology Data Exchange (ETDEWEB)

    Sussmann, A.R. [Department of Radiology, Thoracic Imaging, NYU Langone Medical Center, New York, NY (United States); Ko, J.P., E-mail: jane.ko@nyumc.or [Department of Radiology, Thoracic Imaging, NYU Langone Medical Center, New York, NY (United States)

    2010-02-15

    Chest radiograph interpretation requires an understanding of the mediastinal reflections and anatomical structures. Computed tomography (CT) improves the learning of three-dimensional (3D) anatomy, and more recently multidetector CT (MDCT) technology has enabled the creation of high-quality reformations in varying projections. Multiplanar reformations (MPRs) of varying thickness in the coronal and sagittal projections can be created for direct correlation with findings on frontal and lateral chest radiographs, respectively. MPRs enable simultaneous visualization of the craniocaudal extent of thoracic structures while providing the anatomic detail that has been previously illustrated using cadaveric specimens. Emphasis will be placed on improving knowledge of mediastinal anatomy and reflections including edges, lines, and stripes that are visible on chest radiographs.

  7. Efficient stereological approaches for the volumetry of a normal or enlarged spleen from MDCT images

    Energy Technology Data Exchange (ETDEWEB)

    Mazonakis, Michalis; Stratakis, John; Damilakis, John [University of Crete, Department of Medical Physics, Faculty of Medicine, P.O. Box 2208, Iraklion, Crete (Greece)

    2015-06-01

    To introduce efficient stereological approaches for estimating the volume of a normal or enlarged spleen from MDCT. All study participants underwent an abdominal MDCT. The first group included 20 consecutive patients with splenomegaly and the second group consisted of 20 subjects with a normal spleen. Splenic volume estimations were performed using the stereological point counting method. Stereological assessments were optimized using the systematic slice sampling procedure. Planimetric measurements based on manual tracing of splenic boundaries on each slice were taken as reference values. Stereological analysis using five to eight systematically sampled slices provided enlarged splenic volume estimations with a mean precision of 4.9 ± 1.0 % in a mean time of 2.3 ± 0.4 min. A similar measurement duration and error was observed for normal splenic volume assessment using four to seven systematically selected slices. These stereological approaches slightly but insignificantly overestimated the volume of a normal and enlarged spleen compared to planimetry (P > 0.05) with a mean difference of -1.3 ± 4.3 % and -2.7 ± 5.2 %, respectively. The two methods were highly correlated (r ≥ 0.96). The variability of repeated stereological estimations was below 3.8 %. The proposed stereological approaches enable the rapid, reproducible, and accurate splenic volume estimation from MDCT data in patients with or without splenomegaly. (orig.)

  8. Anemia and the risk of contrast-induced nephropathy in patients with renal insufficiency undergoing contrast-enhanced MDCT

    International Nuclear Information System (INIS)

    Murakami, Ryusuke; Kumita, Shin-ichiro; Hayashi, Hiromitsu; Sugizaki, Ken-ichi; Okazaki, Emi; Kiriyama, Tomonari; Hakozaki, Kenta; Tani, Hitomi; Miki, Izumi; Takeda, Minako

    2013-01-01

    Purpose: The purpose of this study was to assess the effect of anemia on the incidence of contrast-induced nephropathy (CIN) in patients with renal impairment undergoing MDCT. Materials and methods: Institutional review board approval was waived for this retrospective review of 843 patients with stable renal insufficiency (eGFR between 15 and 60 mL/min) who had undergone contrast-enhanced MDCT. Baseline hematocrit and hemoglobin values were measured. Serum creatinine (SCr) was assessed at the baseline and at 48–72 h after contrast administration. Results: The overall incidence of CIN in the patient population with renal insufficiency was 6.9%. CIN developed in 7.8% (54 of 695) of anemic patients, and in 2.8% (4 of 148) of non-anemic patients (P = .027). After adjustment for confounders, low hemoglobin and low hematocrit values remained independent predictors of CIN (odds ratio 4.6, 95% CI 1.0–20.5, P = .046). Conclusions: Anemia is associated with a higher incidence of CIN in patients with renal insufficiency. Anemia is a potentially modifiable risk factor for CIN, and has an unfavorable impact on prognosis in patients with renal insufficiency undergoing contrast-enhanced MDCT

  9. Anemia and the risk of contrast-induced nephropathy in patients with renal insufficiency undergoing contrast-enhanced MDCT

    Energy Technology Data Exchange (ETDEWEB)

    Murakami, Ryusuke, E-mail: rywakana@nms.ac.jp; Kumita, Shin-ichiro; Hayashi, Hiromitsu; Sugizaki, Ken-ichi; Okazaki, Emi; Kiriyama, Tomonari; Hakozaki, Kenta; Tani, Hitomi; Miki, Izumi; Takeda, Minako

    2013-10-01

    Purpose: The purpose of this study was to assess the effect of anemia on the incidence of contrast-induced nephropathy (CIN) in patients with renal impairment undergoing MDCT. Materials and methods: Institutional review board approval was waived for this retrospective review of 843 patients with stable renal insufficiency (eGFR between 15 and 60 mL/min) who had undergone contrast-enhanced MDCT. Baseline hematocrit and hemoglobin values were measured. Serum creatinine (SCr) was assessed at the baseline and at 48–72 h after contrast administration. Results: The overall incidence of CIN in the patient population with renal insufficiency was 6.9%. CIN developed in 7.8% (54 of 695) of anemic patients, and in 2.8% (4 of 148) of non-anemic patients (P = .027). After adjustment for confounders, low hemoglobin and low hematocrit values remained independent predictors of CIN (odds ratio 4.6, 95% CI 1.0–20.5, P = .046). Conclusions: Anemia is associated with a higher incidence of CIN in patients with renal insufficiency. Anemia is a potentially modifiable risk factor for CIN, and has an unfavorable impact on prognosis in patients with renal insufficiency undergoing contrast-enhanced MDCT.

  10. MDCT evaluation of pulmonary embolism in children and young adults following a lateral tunnel Fontan procedure: optimizing contrast-enhancement techniques

    International Nuclear Information System (INIS)

    Prabhu, Sanjay P.; Mahmood, Soran; Sena, Laureen; Lee, Edward Y.

    2009-01-01

    Pulmonary embolism (PE) is a life-threatening thromboembolic complication in patients who have undergone a Fontan procedure for augmenting pulmonary blood flow in the setting of single-ventricle physiology. In patients following a Fontan procedure, lack of proper contrast agent mixing in the right atrium and sluggish, low-velocity blood flow within the Fontan circulation often results in suboptimal contrast enhancement within the pulmonary artery for evaluating PE. Unfortunately, there is a paucity of information describing the optimal contrast-enhancement technique with multidetector CT (MDCT) for evaluating PE in children and young adults following a Fontan procedure. We illustrate the MDCT imaging findings of suboptimal contrast enhancement within the pulmonary artery, which can be mistaken for PE, in patients following a lateral Fontan procedure, and we discuss MDCT techniques to optimize contrast enhancement within the pulmonary artery in these patients for evaluating PE. The MDCT imaging findings in pediatric and young adult patients following a lateral Fontan procedure and with clinically suspected PE are illustrated. We describe intravenous contrast agent injection techniques that can be used to optimize the contrast enhancement in the pulmonary artery in patients following a lateral Fontan procedure. The use of a suboptimal contrast-enhancement technique led to initial misdiagnosis and incomplete evaluation of PE in the three patients following a lateral Fontan procedure. Imaging in two patients showed that optimal evaluation of thrombosis in the Fontan pathway and PE in the pulmonary arteries can be successfully achieved with simultaneous upper- and lower-limb injections of contrast agent. This series demonstrates that suboptimal contrast enhancement can result in misdiagnosis or incomplete evaluation of PE in children and young adults following a lateral Fontan procedure. Careful attention to optimizing contrast enhancement during MDCT examination for

  11. Reverse Redistribution in Myocardial Perfusion Imaging: Revisited with 64-slice MDCT

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Min Kyung; Kim, Jeong Ho; Hwang, Kyung Hoon; Choi, In Suck; Choi, Soo Jin; Choe, Won Sick [Gachon University Gil Hospital, Incheon (Korea, Republic of); Yoon, Min Ki [Good Samaritan Hospital, Pohang (Korea, Republic of)

    2010-06-15

    The authors report myocardial perfusion imaging of a patient showing reverse redistribution (RR) and a 64-slice multidetector-row computed tomography (MDCT) with corresponding findings. The patient had subendocardial myocardial infarction (MI) with positive electrocardiogram (EMG) findings and elevated levels of cardiac isoenzymes. Experiencing this case emphasizes the importance of complementary correlation of a new diagnostic modality that helps us to understand the nature of RR.

  12. The signature of fusion between the embryological derivatives of the first and second branchial arches within the ossicular chain in MDCT

    Directory of Open Access Journals (Sweden)

    Sherif Abdelmonem Shama

    2018-03-01

    Full Text Available The embryological precursors of the ossicular chain of the middle ear in humans are still a matter of debate. Both classical interpretation and dual-arch interpretation are strong hypothesis. The Aim of the work was to use the MDCT in assessment of the sites of expected fusion between the embryological derivatives of the first and second branchial arches within the ossicular chain. This study was conducted on 200 normal ears. Results: The junctional zones were considered as near vertically oriented faint lines running within the malleous and incus in the axial MDCT cuts. Using fine manual manipulation of the scan planes and widow leveling, the presence of these junctional zones was confirmed in 174 sides (87%. Conclusions: The presence of the junctional zones between embryological derivatives of the first and second branchial arches within the ossicular chain at MDCT basis could support the dual arch interpretation at least in most of humans. Whatever the classical or dual arch interpretations or both are correct, the signature of such fusion between embryological derivatives of the first and second branchial arches within the ossicular chain, should be considered as normal variant and should not be mistaken with ossicular erosions, fractures or dislocations. Keywords: First branchial arch, Second branchial arch, Ossicular chain, MDCT

  13. Quantitative assessment of lung volumes using multi-detector row computed tomography (MDCT) in patients with chronic obstructive pulmonary disease (COPD)

    International Nuclear Information System (INIS)

    Lee, Sang Min; Hur, Jin; Kim, Tae Hoon; Kim, Sang Jin; Kim, Hyung Jung

    2008-01-01

    To evaluate the clinical value of the multi-detector row computed tomography (MDCT) in the quantitative assessment of lung volumes and to assess the relationship between the MDCT results and disease severity as determined by a pulmonary function test (PFT) in Chronic Obstructive Pulmonary Disease (COPD) patients. We performed a PFT and MDCT on 39 COPD patients. Using the GOLD classifications, we divided the patients into three groups according to disease severity; stage I (mild, n = 10), stage II (moderate, n = 15), and stage III (severe, n = 14). Using the pulmo-CT software program, we measured the proportion of lung volumes with attenuation values below -910 and -950 HU. The mean FEV1 (% of predicted) and FEV1/FVC was 82.2 ± 2% and 66.2 ± 3% in stage I, 53.5 ± 11% and 52 ± 6% in stage II, and 32.3 ± 7% and 44.2% ± 13% in stage III, respectively. Differences in lung volume percentage at each of the thresholds (-910 and -950 HU) among the 3 stages were statistically significant (ρ < 0.01, ρ < 0.01) and correlated well with the FEV1 and FEV1/FVC (r = -0.803, r -0.766, r = -0.817, and r = -0.795, respectively). The volumetric measurement obtained by MDCT provides an accurate means of quantifying pulmonary emphysema

  14. Sinonasal imaging after Caldwell-Luc surgery: MDCT findings of an abandoned procedure in times of functional endoscopic sinus surgery

    International Nuclear Information System (INIS)

    Nemec, Stefan Franz; Peloschek, Philipp; Koelblinger, Claus; Mehrain, Sheida; Krestan, Christian Robert; Czerny, Christian

    2009-01-01

    Background and purpose: Today, functional endoscopic sinus surgery (FESS) is performed in most of the patients with sinonasal inflammatory disease. The postoperative imaging findings of FESS in multidetector computed tomography (MDCT) considerably differ from those of historic Caldwell-Luc (CL) maxillary sinus surgery which is an uncommon procedure today. Thus, the postoperative CL imaging findings may lead to diagnostic confusion and misinterpretation. Therefore, this study explicitly presents the MDCT findings of post-CL patients which have not been described previously. Methods: Twenty-eight patients with clinically suspected sinusitis and documented history of CL-procedure underwent 16 row MDCT (MDCT Mx8000 IDT Philips) with multiplanar reconstructions of the paranasal sinuses in the axial plane. The following parameters were used: 140 kV, 50 mAs; 16 mm x 0.75 mm detector collimation; 1 mm reconstructed slice thickness; 0.5 mm increment. The studies were reconstructed with a bone algorithm (W3000/L600; 1 mm slice thickness) in axial plane and coronal plane (3 mm slice thickness). The images were retrospectively evaluated for the presence of normal surgery-related and pathological findings. Results: Surgery-related imaging characteristics presented as follows: an anterior and a medial bony wall defect and sclerosis and sinus wall thickening were observed in all 28/28 cases (100%). Collaps of the sinus cavity was seen in 26/28 cases (92.9%). Furthermore, inflammatory disease of the operated sinus(es) was found in 23/28 cases (82.1%): 14/28 patients (50%) had inflammatory mucosal thickening of the operated sinus(es) as well as of other sinonasal cavities and 9/28 patients (32.1%) had inflammatory mucosal thickening limited to the operated sinus(es). A postoperative mucocele was depicted in 3/28 cases (10.7%). 2/28 patients (7.1%) showed neither maxillary nor other mucosal swelling. Conclusion: MDCT with multiplanar reconstructions is a precise method to evaluate

  15. Abdominal Hernias, Giant Colon Diverticulum, GIST, Intestinal Pneumatosis, Colon Ischemia, Cold Intussusception, Gallstone Ileus, and Foreign Bodies: Our Experience and Literature Review of Incidental Gastrointestinal MDCT Findings

    Science.gov (United States)

    Gatta, G.; Rella, R.; Donatello, D.; Falco, G.; Grassi, R.

    2017-01-01

    Incidental gastrointestinal findings are commonly detected on MDCT exams performed for various medical indications. This review describes the radiological MDCT spectrum of appearances already present in the past literature and in today's experience of several gastrointestinal acute conditions such as abdominal hernia, giant colon diverticulum, GIST, intestinal pneumatosis, colon ischemia, cold intussusception, gallstone ileus, and foreign bodies which can require medical and surgical intervention or clinical follow-up. The clinical presentation of this illness is frequently nonspecific: abdominal pain, distension, nausea, fever, rectal bleeding, vomiting, constipation, or a palpable mass, depending on the disease. A proper differential diagnosis is essential in the assessment of treatment and in this case MDCT exam plays a central rule. We wish that this article will familiarize the radiologist in the diagnosis of this kind of incidental MDCT findings for better orientation of the therapy. PMID:28638830

  16. Abdominal Hernias, Giant Colon Diverticulum, GIST, Intestinal Pneumatosis, Colon Ischemia, Cold Intussusception, Gallstone Ileus, and Foreign Bodies: Our Experience and Literature Review of Incidental Gastrointestinal MDCT Findings.

    Science.gov (United States)

    Di Grezia, G; Gatta, G; Rella, R; Donatello, D; Falco, G; Grassi, R; Grassi, R

    2017-01-01

    Incidental gastrointestinal findings are commonly detected on MDCT exams performed for various medical indications. This review describes the radiological MDCT spectrum of appearances already present in the past literature and in today's experience of several gastrointestinal acute conditions such as abdominal hernia, giant colon diverticulum, GIST, intestinal pneumatosis, colon ischemia, cold intussusception, gallstone ileus, and foreign bodies which can require medical and surgical intervention or clinical follow-up. The clinical presentation of this illness is frequently nonspecific: abdominal pain, distension, nausea, fever, rectal bleeding, vomiting, constipation, or a palpable mass, depending on the disease. A proper differential diagnosis is essential in the assessment of treatment and in this case MDCT exam plays a central rule. We wish that this article will familiarize the radiologist in the diagnosis of this kind of incidental MDCT findings for better orientation of the therapy.

  17. Academic self-concept, learning motivation, and test anxiety of the underestimated student.

    Science.gov (United States)

    Urhahne, Detlef; Chao, Sheng-Han; Florineth, Maria Luise; Luttenberger, Silke; Paechter, Manuela

    2011-03-01

    BACKGROUND. Teachers' judgments of student performance on a standardized achievement test often result in an overestimation of students' abilities. In the majority of cases, a larger group of overestimated students and a smaller group of underestimated students are formed by these judgments. AIMS. In this research study, the consequences of the underestimation of students' mathematical performance potential were examined. SAMPLE. Two hundred and thirty-five fourth grade students and their fourteen mathematics teachers took part in the investigation. METHOD. Students worked on a standardized mathematics achievement test and completed a self-description questionnaire about motivation and affect. Teachers estimated each individual student's potential with regard to mathematics test performance as well as students' expectancy for success, level of aspiration, academic self-concept, learning motivation, and test anxiety. The differences between teachers' judgments on students' test performance and students' actual performance were used to build groups of underestimated and overestimated students. RESULTS. Underestimated students displayed equal levels of test performance, learning motivation, and level of aspiration in comparison with overestimated students, but had lower expectancy for success, lower academic self-concept, and experienced more test anxiety. Teachers expected that underestimated students would receive lower grades on the next mathematics test, believed that students were satisfied with lower grades, and assumed that the students have weaker learning motivation than their overestimated classmates. CONCLUSION. Teachers' judgment error was not confined to test performance but generalized to motivational and affective traits of the students. © 2010 The British Psychological Society.

  18. MDCT abnormalities of small- and medium-sized bronchus in active tuberculosis: a new angle on an old disease

    International Nuclear Information System (INIS)

    Oh, Jin Kyoung; Ahn, Myeong Im; Jung, Jung Im; Han, Dae Hee; Kim, Young Kyoon; Oh, Eun-Jee; Park, Yeon-Joon

    2011-01-01

    Background: The incidence and findings of tuberculous invasion of the peripheral bronchus have not been fully investigated with MDCT. Purpose: To evaluate the prevalence and findings of MDCT abnormalities of small- and medium-sized bronchus (SMB) in active pulmonary tuberculosis (TB). Material and Methods: Using multiplanar reformation, 35 consecutive MDCT scans (follow-up exams available in 14 patients with a mean interval of 8.1 months) were assessed for following abnormalities of SMB: bronchial impaction (BI), wall thickening, dilatation, peribronchial cuff of soft tissue, and bronchocavitary fistula. It was also assessed whether tree-in-buds (TIB) have a tendency to distribute in the territories of diseased SMB, and whether SMB abnormalities are present in patients with relatively mild disease. Results: SMB abnormalities were observed in 23 (65.7%) patients with active TB. The most frequent finding was wall thickening (n=18, 51.4%), followed by BI (n=13, 37.1%; zigzag-shaped in four), dilatation (n =11, 31.4%), amputated appearance of air column (n=11, 31.4%), peribronchial cuff of soft tissue (n=10, 28.6%), and bronchocavitary fistula (n=8, 22.9%). TIB (n=29; absent in two patients with SMB) was mainly within (n=14) or close to (n=4) the territory of diseased SMB. Follow-up CT frequently showed improvement of wall thickening (11/12) and persistence of bronchial dilatation (11/13). SMB abnormality was present in all of six patients with mild disease. Conclusion: MDCT shows that tuberculous invasion of the peripheral bronchus may be more frequent than previously thought, of which findings include wall thickening, BI, dilatation, amputated appearance of air column, peribronchial cuff of soft tissue and bronchocavitary fistula

  19. MDCT abnormalities of small- and medium-sized bronchus in active tuberculosis: a new angle on an old disease

    Energy Technology Data Exchange (ETDEWEB)

    Oh, Jin Kyoung; Ahn, Myeong Im; Jung, Jung Im; Han, Dae Hee (Dept. of Radiology, Seoul St Mary' s Hospital, The Catholic Univ. of Korea, Seoul (Korea, Republic of)), email: lepolder@gmail.com; Kim, Young Kyoon (Dept. of Internal Medicine, Seoul St Mary' s Hospital, The Catholic Univ. of Korea, Seoul (Korea, Republic of)); Oh, Eun-Jee; Park, Yeon-Joon (Dept. of Laboratory Medicine, Seoul St Mary' s Hospital, The Catholic Univ. of Korea, Seoul (Korea, Republic of))

    2011-02-15

    Background: The incidence and findings of tuberculous invasion of the peripheral bronchus have not been fully investigated with MDCT. Purpose: To evaluate the prevalence and findings of MDCT abnormalities of small- and medium-sized bronchus (SMB) in active pulmonary tuberculosis (TB). Material and Methods: Using multiplanar reformation, 35 consecutive MDCT scans (follow-up exams available in 14 patients with a mean interval of 8.1 months) were assessed for following abnormalities of SMB: bronchial impaction (BI), wall thickening, dilatation, peribronchial cuff of soft tissue, and bronchocavitary fistula. It was also assessed whether tree-in-buds (TIB) have a tendency to distribute in the territories of diseased SMB, and whether SMB abnormalities are present in patients with relatively mild disease. Results: SMB abnormalities were observed in 23 (65.7%) patients with active TB. The most frequent finding was wall thickening (n=18, 51.4%), followed by BI (n=13, 37.1%; zigzag-shaped in four), dilatation (n =11, 31.4%), amputated appearance of air column (n=11, 31.4%), peribronchial cuff of soft tissue (n=10, 28.6%), and bronchocavitary fistula (n=8, 22.9%). TIB (n=29; absent in two patients with SMB) was mainly within (n=14) or close to (n=4) the territory of diseased SMB. Follow-up CT frequently showed improvement of wall thickening (11/12) and persistence of bronchial dilatation (11/13). SMB abnormality was present in all of six patients with mild disease. Conclusion: MDCT shows that tuberculous invasion of the peripheral bronchus may be more frequent than previously thought, of which findings include wall thickening, BI, dilatation, amputated appearance of air column, peribronchial cuff of soft tissue and bronchocavitary fistula

  20. Sixty-four-slice multidetector computed tomography for preoperative evaluation of left ventricular function and mass in patients with mitral regurgitation: comparison with magnetic resonance imaging and echocardiography

    International Nuclear Information System (INIS)

    Guo, Ying-kun; Yang, Zhi-gang; Ning, Gang; Rao, Li; Pen, Ying; Wu, Yang; Dong, Li; Zhang, Tai-ming; Zhang, Xiao-chun; Wang, Qi-ling

    2009-01-01

    Quantitative values of left ventricular (LV) function and muscle mass in patients with mitral regurgitation are independent predictors of cardiac morbidity and mortality. The aim of this study was to prospectively evaluate whether 64-MDCT can assess the LV function in patients with mitral regurgitation with high accuracy when compared with the MRI and echocardiography results. Fifty-one patients with mitral regurgitation underwent retrospectively ECG-gated 64-MDCT, echocardiography, and MRI for assessing the global ventricular function. End-diastolic and end-systolic volume, stroke volume, ejection fraction, and mass were measured on 64-MDCT and echocardiography, and compared with the results measured on MRI which served as the reference standard. Intertechnique agreement was tested by using Pearson's correlation and Bland-Altman analyses. No significant differences were revealed in calculated LV function and mass between the 64-MDCT and MRI (paired t test, p = 0.07-0.53). Pearson's correlation analysis showed the functional parameters and mass correlated closely between the 64-MDCT and MRI (r = 0.89-0.96, p < 0.001). When compared with MRI, echocardiography underestimated the volumetric parameters of LV (paired t test, p = 0.0003-0.004), but significantly overestimated the EF values (p = 0.003), and moderate correlations of functional parameters were obtained (r = 0.78, 0.60, 0.81, and 0.62, respectively). ECG-gated 64-MDCT allows for accurate and reliable assessment of LV function in patients with mitral regurgitation, whereas LV volumes measured by two-dimensional echocardiography were underestimated and the ejection fraction was overestimated when compared with those achieved by using MRI. (orig.)

  1. Abdominal Hernias, Giant Colon Diverticulum, GIST, Intestinal Pneumatosis, Colon Ischemia, Cold Intussusception, Gallstone Ileus, and Foreign Bodies: Our Experience and Literature Review of Incidental Gastrointestinal MDCT Findings

    Directory of Open Access Journals (Sweden)

    G. Di Grezia

    2017-01-01

    Full Text Available Incidental gastrointestinal findings are commonly detected on MDCT exams performed for various medical indications. This review describes the radiological MDCT spectrum of appearances already present in the past literature and in today’s experience of several gastrointestinal acute conditions such as abdominal hernia, giant colon diverticulum, GIST, intestinal pneumatosis, colon ischemia, cold intussusception, gallstone ileus, and foreign bodies which can require medical and surgical intervention or clinical follow-up. The clinical presentation of this illness is frequently nonspecific: abdominal pain, distension, nausea, fever, rectal bleeding, vomiting, constipation, or a palpable mass, depending on the disease. A proper differential diagnosis is essential in the assessment of treatment and in this case MDCT exam plays a central rule. We wish that this article will familiarize the radiologist in the diagnosis of this kind of incidental MDCT findings for better orientation of the therapy.

  2. Potential benefit of a simultaneous, side-by-side display of contrast MDCT and echocardiography over routine sequential imaging for assessment of adult congenital heart disease: A preliminary study.

    Science.gov (United States)

    Oe, Hiroki; Watanabe, Nobuhisa; Miyoshi, Toru; Osawa, Kazuhiro; Akagi, Teiji; Kanazawa, Susumu; Ito, Hiroshi

    2018-06-18

    Management of adult congenital heart disease (ACHD) patients requires understanding of its complex morphology and functional features. An innovative imaging technique has been developed to display a virtual multi-planar reconstruction obtained from contrast-enhanced multidetector-computed tomography (MDCT) corresponding to the same cross-sectional image from transthoracic echocardiography (TTE). The aim of this study is to assess the usefulness of this imaging technology in ACHD patients. This study consisted of 46 consecutive patients (30 women; mean age, 52±18 years old) with ACHD who had undergone contrast MDCT. All patients underwent TTE within a week of MDCT. An experienced sonographer who did not know the results of MDCT conducted a diagnosis using TTE and, then, using the new imaging technology. We studied whether this imaging technology provided additional or unexpected findings or makes more accurate diagnosis. In this imaging technology, MDCT cross-section provides higher-resolution image to the deep compared to corresponding TTE image. Depending on the MDCT section which can be arbitrarily set under the echo guide, we can diagnose unexpected or incremental lesions or more accurately assess the severity of the lesion in 27 patients (59%) compared to TTE study alone. This imaging technology was useful in the following situations: CONCLUSIONS: This integrated imaging technology provides incremental role over TTE in complex anatomy, and allows functional information in ACHD patients. Copyright © 2018 Japanese College of Cardiology. Published by Elsevier Ltd. All rights reserved.

  3. Assessment and diagnosis of acute bowel ischemia with multidetector computed tomography (MDCT)

    International Nuclear Information System (INIS)

    Sojka, B.; Gieszczyk-Paraniak, B.; Gibinska, J.; Konopka, M.

    2008-01-01

    Acute bowel ischemia (ABT) is a life-threatening condition which most often effects elderly patients. It requires an intensive treatment and quick diagnosis. Unfortunately ABI manifested not only by specific but also various nonspecific clinical or laboratory finding. The radiological symptoms of the bowel ischemia are also differentiated and often nonspecific while the specific findings are rather uncommon.That is why the knowledge of the bowel ischemia pathogenesis and possible CT findings is so important for the correct diagnosis. The our paper, we present the radiological findings of the acute bowel ischemia based on the analysis of the patients' abdominal -CT examination. The purpose of our study is to MDCT in patients with acute bowel ischemia. The material of this study consists of four computer tomography examinations - three of those an angio-CT and one abdominal - in patients with acute abdomen symptoms. The result revealed the mesenteric thrombosis in two cases, and mesenteric artery stenosis in one case. In one case, the thrombus was present in the abdominal aorta. In conclusion, we claim that the MDCT should be the modality of choice for the diagnosis of the acute bowel ischemia. (author)

  4. Chronic rhinosinusitis in Europe - an underestimated disease. A GA(2) LEN study

    DEFF Research Database (Denmark)

    Hastan, D; Fokkens, W J; Bachert, C

    2011-01-01

    , Zuberbier T, Jarvis D, Burney P. Chronic rhinosinusitis in Europe - an underestimated disease. A GA(2) LEN study. Allergy 2011; 66: 1216-1223. ABSTRACT: Background:  Chronic rhinosinusitis (CRS) is a common health problem, with significant medical costs and impact on general health. Even so, prevalence...

  5. Renal cell carcinoma metastases to the pancreas - Value of arterial phase imaging at MDCT

    International Nuclear Information System (INIS)

    Corwin, Michael T.; Lamba, Ramit; McGahan, John P.; Wilson, Machelle

    2013-01-01

    Background: The pancreas is an increasingly recognized site of renal cell carcinoma metastases. It is important to determine the optimal MDCT protocol to best detect RCC metastases to the pancreas. Purpose: To compare the rate of detection of renal cell carcinoma metastases to the pancreas between arterial and portal venous phase MDCT. Material and Methods: A retrospective review of CTs of the abdomen yielded six patients with metastatic RCC to the pancreas. Five of six patients had pathologically proven clear cell RCC. Two blinded reviewers independently reported the number of pancreatic lesions seen in arterial and venous phases. Each lesion was graded as definite or possible. The number of lesions was determined by consensus review of both phases. Attenuation values were obtained for metastatic lesions and adjacent normal pancreas in both phases. Results: There were a total of 24 metastatic lesions to the pancreas. Reviewer 1 identified 20/24 (83.3%) lesions on the arterial phase images and 13/24 (54.2%) lesions on the venous phase. Seventeen of 20 (85.0%) arterial lesions were deemed definite and 9/13 (69.2%) venous lesions were definite. Reviewer 2 identified 19/24 (79.2%) lesions on the arterial phase and 14/24 (58.3%) on the venous phase. Seventeen of 19 (89.5%) arterial lesions were definite and 7/14 (50%) venous lesions were definite. Mean attenuation differential between lesion and pancreas was 114 HU and 39 HU for arterial and venous phases, respectively (P<0.0001). Conclusion: Detection of RCC metastases to the pancreas at MDCT is improved using arterial phase imaging compared to portal venous phase imaging

  6. Influence of Contrast Media on Bone Mineral Density (BMD) Measurements from Routine Contrast-Enhanced MDCT Datasets using a Phantom-less BMD Measurement Tool.

    Science.gov (United States)

    Toelly, Andrea; Bardach, Constanze; Weber, Michael; Gong, Rui; Lai, Yanbo; Wang, Pei; Guo, Yulin; Kirschke, Jan; Baum, Thomas; Gruber, Michael

    2017-06-01

    Aim  To evaluate the differences in phantom-less bone mineral density (BMD) measurements in contrast-enhanced routine MDCT scans at different contrast phases, and to develop an algorithm for calculating a reliable BMD value. Materials and Methods  112 postmenopausal women from the age of 40 to 77 years (mean age: 57.31 years; SD 9.61) who underwent a clinically indicated MDCT scan, consisting of an unenhanced, an arterial, and a venous phase, were included. A retrospective analysis of the BMD values of the Th12 to L4 vertebrae in each phase was performed using a commercially available phantom-less measurement tool. Results  The mean BMD value in the unenhanced MDCT scans was 79.76 mg/cm³ (SD 31.20), in the arterial phase it was 85.09 mg/cm³ (SD 31.61), and in the venous phase it was 86.18 mg/cm³ (SD 31.30). A significant difference (p Influence of Contrast Media on Bone Mineral Density (BMD) Measurements from Routine Contrast-Enhanced MDCT Datasets using a Phantom-less BMD Measurement Tool. Fortschr Röntgenstr 2017; 189: 537 - 543. © Georg Thieme Verlag KG Stuttgart · New York.

  7. Potential contribution of multiplanar reconstruction (MPR) to computer-aided detection of lung nodules on MDCT

    International Nuclear Information System (INIS)

    Matsumoto, Sumiaki; Ohno, Yoshiharu; Yamagata, Hitoshi; Nogami, Munenobu; Kono, Atsushi; Sugimura, Kazuro

    2012-01-01

    Purpose: To evaluate potential benefits of using multiplanar reconstruction (MPR) in computer-aided detection (CAD) of lung nodules on multidetector computed tomography (MDCT). Materials and methods: MDCT datasets of 60 patients with suspected lung nodules were retrospectively collected. Using “second-read” CAD, two radiologists (Readers 1 and 2) independently interpreted these datasets for the detection of non-calcified nodules (≥4 mm) with concomitant confidence rating. They did this task twice, first without MPR (using only axial images), and then 4 weeks later with MPR (using also coronal and sagittal MPR images), where the total reading time per dataset, including the time taken to assess the detection results of CAD software (CAD assessment time), was recorded. The total reading time and CAD assessment time without MPR and those with MPR were statistically compared for each reader. The radiologists’ performance for detecting nodules without MPR and the performance with MPR were compared using jackknife free-response receiver operating characteristic (JAFROC) analysis. Results: Compared to the CAD assessment time without MPR (mean, 69 s and 57 s for Readers 1 and 2), the CAD assessment time with MPR (mean, 46 s and 45 s for Readers 1 and 2) was significantly reduced (P < 0.001). For Reader 1, the total reading time was also significantly shorter in the case with MPR. There was no significant difference between the detection performances without MPR and with MPR. Conclusion: The use of MPR has the potential to improve the workflow in CAD of lung nodules on MDCT.

  8. Preoperative evaluation of colorectal liver metastases: comparison between gadoxetic acid-enhanced 3.0-T MRI and contrast-enhanced MDCT with histopathological correlation

    Energy Technology Data Exchange (ETDEWEB)

    Scharitzer, M.; Ba-Ssalamah, A.; Ringl, H.; Koelblinger, C.; Weber, M. [Medical University of Vienna, Department of Radiology, Vienna (Austria); Gruenberger, T. [Medical University of Vienna, Department of Surgery, Vienna (Austria); Schima, W. [Department of Radiology, KH Goettlicher Heiland, KH der Barmherzigen Schwestern and St Josef-Krankenhaus, Vienna (Austria)

    2013-08-15

    The aim of this prospective study was to compare the diagnostic performance of 64-row MDCT and gadoxetic-acid-enhanced MRI at 3.0 T in patients with colorectal liver metastases in correlation with histopathological findings. Lesions detected at MDCT and MRI were interpreted by three blinded readers and compared with histopathological workup as the term of reference. Two subgroups of lesions were additionally evaluated: (1) metastases smaller than 10 mm and (2) lesions in patients with and without steatosis of the liver, assessed histopathologically. Surgery and histopathological workup revealed 81 colorectal liver metastases in 35 patients and diffuse metastatic involvement in 3 patients. In a lesion-by-lesion analysis, significant sensitivity differences could only be found for reader 1 (P = 0.035) and reader 3 (P = 0.003). For segment-based evaluation, MRI was more sensitive only for reader 3 (P = 0.012). The number of false-positive results ranged from 3 to 12 for MDCT and 8 to 11 for MRI evaluation. In the group of small lesions, the sensitivity differed significantly between both methods (P = 0.003). In patients with hepatic steatosis, MRI showed a trend toward better performance than MDCT, but without statistical performance. The 3.0-T MRI with liver-specific contrast agents is the preferred investigation in the preoperative setting, especially for the assessment of small colorectal liver metastases. (orig.)

  9. 256-MDCT for evaluation of urolithiasis: iterative reconstruction allows for a significant reduction of the applied radiation dose while maintaining high subjective and objective image quality

    International Nuclear Information System (INIS)

    Veldhoen, Simon; Laqmani, Azien; Derlin, Thorsten; Karul, Murat; Hammerle, Diego; Adam, Gerhard; Regier, Marc; Buhk, Jan-Hendrick; Sehner, Susanne; Nagel, Hans D.; Chun, Felix

    2014-01-01

    Multidetector CT (MDCT) is the established imaging modality in diagnostics of urolithiasis. The aim of iterative reconstruction (IR) is to allow for a radiation dose reduction while maintaining high image quality. This study evaluates its performance in MDCT for assessment of urolithiasis. Fifty-two patients underwent non-contrast abdominal MDCT. Twenty-six patients were referred to MDCT under suspicion of urolithiasis, and examined using a dose-reduced scan protocol (RDCT). Twenty-six patients, who had undergone standard-dose MDCT, served as reference for radiation dose comparison. RDCT images were reconstructed using an IR system (iDose4™, Philips Healthcare, Cleveland, OH, USA). Objective image noise (OIN) was recorded and five radiologists rated the subjective image quality independently. Radiation parameters were derived from the scan protocols. The CTDIvol could be reduced by 50% to 5.8 mGy (P < 0.0001). The same reduction was achieved for DLP and effective dose to 253 ± 27 mGy*cm (P < 0.0001) and 3.9 ± 0.4 mSv (P < 0.0001). IR led to a reduction of the OIN of up to 61% compared with classic filtered back projection (FBP) (P < 0.0001). The OIN declined with increasing IR levels. RDCT with FBP showed the lowest scores of subjective image quality (2.32 ± 0.04). Mean scores improved with increasing IR levels. iDose6 was rated with the best mean score (3.66 ± 0.04). The evaluated IR-tool and protocol may be applied to achieve a considerable radiation dose reduction in MDCT for diagnostics of urolithiasis while maintaining a confident image quality. Best image quality, suitable for evaluation of the entire abdomen concerning differential diagnoses, was achieved with iDose6.

  10. Head and neck imaging with MDCT

    International Nuclear Information System (INIS)

    Imhof, H.; Czerny, Chr.; Dirisamer, A.

    2003-01-01

    Multi-slice CT (MDCT) is rapidly becoming the new standard in radiological imaging. Although its advantages in cardiovascular, thoracic and abdominal imaging are evident, the extent of its usefulness for imaging the head and neck has yet to be clarified. Because of the shorter examination time motion artifacts are reduced, phonation-studies are possible. Due to the thin-slicing and nearly isotropic multiplanar reconstruction (MPR) examination in only one plane is necessary, saving both time and radiation exposure. The shorter examination requires the use of higher concentrated contrast medium (400 mg of iodine/ml). The use of such a contrast medium produces a higher degree of contrast enhancement and provides a 5-10% higher contrast between the surrounding normal and pathological tissue, but is more time critical. MPRs are easily done in any plane within seconds and enables also three-dimensional visualization, what helps in the use of minimal invasive therapy, training and teaching and provides a way of handling the hundreds of images acquired during scanning

  11. Empirical description of bronchial and nonbronchial arteries with MDCT

    Energy Technology Data Exchange (ETDEWEB)

    Yu Hong, E-mail: yuhong.2002@hotmail.co [Department of Imageology, Changzheng hospital, Second Military Medical University, Shanghai 200003 (China); Liu Shiyuan, E-mail: cjr.liushiyuan@vip.163.co [Department of Imageology, Changzheng hospital, Second Military Medical University, Shanghai 200003 (China); Li Huimin, E-mail: yuhongphd@163.co [Department of Imageology, Changzheng hospital, Second Military Medical University, Shanghai 200003 (China); Xiao Xiangsheng, E-mail: cjr.xxsh@vip.163.co [Department of Imageology, Changzheng hospital, Second Military Medical University, Shanghai 200003 (China); Dong Weihua, E-mail: dongweihua2000@163.co [Department of Imageology, Changzheng hospital, Second Military Medical University, Shanghai 200003 (China)

    2010-08-15

    Purpose: We aimed to retrospectively evaluate bronchial and nonbronchial systemic arteries using multi-detector row helical computed tomographic (MDCT) angiography in patients with pulmonary disorders. Materials and Methods: Thirty-nine patients (24 men, 15 women; mean age, 63.4 years; range, 20-82 years) with congenital and acquired pulmonary disorders of the bronchial and nonbronchial systemic arteries underwent multi-detector row helical computed tomographic angiography of the thorax using a 16-detector row scanner. Each of these patients had experienced an episode of hemoptysis. Computed tomographic angiogram data, which included maximum intensity projections, multiplanar reconstruction, and three-dimensional volume-rendered images, were used to retrospectively analyse the characteristics of the bronchial and nonbronchial systemic arteries. Results: We identified a total of 128 bronchial arteries (76 on the right side and 52 on the left) in 39 patients. We detected 42 nonbronchial systemic artery branches, including 19 internal mammary artery branches, 8 subclavian artery branches, 8 inferior phrenic artery branches, 5 intercostal artery branches, 1 thyrocervical trunk branch, and 1 celiac trunk branch. Thirty-five dilated and tortuous nonbronchial systemic arteries entered into the lung parenchyma and extended down to the lesions. Every case, except the one case of sequestration, was associated with pleural thickening where the vascular structures passed through the extrapleural fat. Conclusions: The variations in both the bronchial artery anatomy and the location and type of the nonbronchial arteries were great. Nonbronchial arteries may be a significant source of hemoptysis. MDCT angiography can be used to detect detailed anatomical information about the origins and courses of bronchial and nonbronchial systemic arteries and their pathophysiologic features.

  12. Italian multicenter, prospective study to evaluate the negative predictive value of 16- and 64-slice MDCT imaging in patients scheduled for coronary angiography (NIMISCAD-non invasive multicenter Italian study for coronary artery disease)

    International Nuclear Information System (INIS)

    Marano, Riccardo; Cobelli, Francesco de; Maschio, Alessandro del; Becker, Christoph; Herzog, Christopher; Centonze, Maurizio; Morana, Giovanni; Gualdi, Gian Franco; Ligabue, Guido; Pontone, Gianluca; Catalano, Carlo; Chiappino, Dante; Midiri, Massimo; Simonetti, Giovanni; Marchisio, Filippo; Olivetti, Lucio; Fattori, Rossella; Bonomo, Lorenzo

    2009-01-01

    This was a prospective, multicenter study designed to evaluate the utility of MDCT in the diagnosis of coronary artery disease (CAD) in patients scheduled for elective coronary angiography (CA) using different MDCT systems from different manufacturers. Twenty national sites prospectively enrolled 367 patients between July 2004 and June 2006. Computed tomography (CT) was performed using a standardized/optimized scan protocol for each type of MDCT system (≥16 slices) and compared with quantitative CA performed within 2 weeks of MDCT. A total of 284 patients (81%) were studied by 16-slice MDCT systems, while 66 patients (19%) by 64-slice MDCT scanners. The primary analysis was on-site/off-site evaluation of the negative predictive value (NPV) on a per-patient basis. Secondary analyses included on-site evaluation on a per-artery and per-segment basis. On-site evaluation included 327 patients (CAD prevalence 58%). NPV, positive predictive value (PPV), sensitivity, specificity, and diagnostic accuracy (DA) were 0.91 (95% CI 0.85-0.95), 0.91 (95% CI 0.86-0.95), 0.94 (95% CI 0.89-0.97), 0.88 (95% CI 0.81-0.93), and 0.91 (95% CI 0.88-0.94), respectively. Off-site analysis included 295 patients (CAD prevalence 56%). NPV, PPV, sensitivity, specificity, and DA were 0.73 (95% CI 0.65-0.79), 0.93 (95% CI 0.87-0.97), 0.73 (95% CI 0.65-0.79), 0.93 (95% CI 0.87-0.97), and 0.82 (95% CI 0.77-0.86), respectively. The results of this study demonstrate the utility of MDCT in excluding significant CAD even when conducted by centers with varying degrees of expertise and using different MDCT machines. (orig.)

  13. Evaluation of multiple trauma victims with 16-row multidetector CT (MDCT): a time analysis

    International Nuclear Information System (INIS)

    Heyer, C.M.; Nicolas, V.

    2005-01-01

    Purpose: Description and time analysis of a 16-row MDCT protocol in the evaluation of multiple trauma patients considering transport, time of scanning, patient positioning, image reconstruction, and image interpretation. Materials and methods: Between May and December 2004, 60 multiple trauma patients underwent 16-row MDCT (Sensation, Siemens, Erlangen, Germany). The protocol included serial scanning of the head, spiral scanning of the cervical spine and contrast-enhanced spiral scanning of the thorax/abdomen with multiplanar reformations (MPR) of the thoracic/lumbar spine and the pelvis. All time intervals including transport, patient positioning, scanning, duration of MPR, total time in the examination room, and time to first and final image interpretation were prospectively evaluated. Furthermore, patient characteristics, trauma profiles, and mortality rates were recorded. Results: 46 male and 14 female patients (mean age 43.6 years) were enrolled in the study. Time analysis of 16-row MDCT revealed the following results (mean time standard deviation): Emergency room treatment and transport 19.2±6.7 min, patient positioning 16.5±6.5 min, scan duration 8.0±3.3 min, total time in examination room 24.5±7.2 min, image reconstruction including MPR 32.0±16.4 min, and time of first (16.4±4.7 min) and final image interpretation (82.5±30.4 min). Trauma profiles revealed thoracic injuries in 35/60 patients (58.3%), head injuries in 23/60 patients (38.3%), abdominal injuries in 15/60 patients (25.0%), injuries of the cervical (9/60 patients, 15.0%), thoracic (12/60 patients, 20.0%), and lumbar spine (19/60 patients, 31.7%), pelvic injuries in 13/60 patients (21.7%), and injuries of extremities in 39/60 patients (65.0%). The mortality rate was 21.7%. (orig.)

  14. Inter-scan reproducibility of coronary calcium measurement using Multi Detector-Row Computed Tomography (MDCT)

    International Nuclear Information System (INIS)

    Sabour, Siamak; Rutten, A.; Schouw, Y. T. van der; Atsma, F.; Grobbee, D. E.; Mali, W. P.; Bartelink, M. E. L.; Bots, M. L.; Prokop, M.

    2007-01-01

    Purpose. To assess inter-scan reproducibility of coronary calcium measurements obtained from Multi Detector-Row CT (MDCT) images and to evaluate whether this reproducibility is affected by different measurement protocols, slice thickness, cardiovascular risk factors and/or technical variables.Design. Cross-sectional study with repeated measurements. Materials and methods. The study population comprised 76 healthy women. Coronary calcium was assessed in these women twice in one session using 16-MDCT (Philips Mx 8000 IDT 16). Images were reconstructed with 1.5 mm slice thickness and 3.0 mm slice thickness. The 76 repeated scans were scored. The Agatston score, a volume measurement and a mass measurement were assessed. Reproducibility was determined by estimation of mean, absolute, relative difference, the weighted kappa value for agreement and the Intra-class correlation coefficient (ICCC).Results. Fifty-five participants (72.4%) had a coronary calcification of more than zero in Agatston (1.5 mm slice thickness). The reproducibility of coronary calcium measurements between scans in terms of ranking was excellent with Intra-class correlation coefficients of >0.98, and kappa values above 0.80. The absolute difference in calcium score between scans increased with increasing calcium levels, indicating that measurement error increases with increasing calcium levels. However, no relation was found between the mean difference in scores and calcium levels, indicating that the increase in measurement error is likely to result in random misclassification in calcium score. Reproducibility results were similar for 1.5 mm slices and for 3.0 mm slices, and equal for Agatston, volume and mass measurements.Conclusion. Inter-scan reproducibility of measurement of coronary calcium using images from MDCT is excellent, irrespective of slice thickness and type of calcium parameter

  15. Imaging of Herniated Discs of the Cervical Spine: Inter-Modality Differences between 64-Slice Multidetector CT and 1.5-T MRI

    Energy Technology Data Exchange (ETDEWEB)

    Yi, Ji Sook; Cha, Jang Gyu [Dept. of Radiology, Soonchunhyang University Bucheon Hospital, Bucheon (Korea, Republic of); Han, Jong Kyu [Dept. of Radiology, Soonchunhyang University Cheonan Hospital, Cheonan (Korea, Republic of); Kim, Hyun Joo [Dept. of Radiology, Soonchunhyang University Seoul Hospital, Seoul (Korea, Republic of)

    2015-08-15

    To assess inter-modality variability when evaluating cervical intervertebral disc herniation using 64-slice multidetector-row computed tomography (MDCT) and magnetic resonance imaging (MRI). Three musculoskeletal radiologists independently reviewed cervical spine 1.5-T MRI and 64-slice MDCT data on C2-3 though C6-7 of 51 patients in the context of intervertebral disc herniation. Interobserver and inter-modality agreements were expressed as unweighted kappa values. Weighted kappa statistics were used to assess the extents of agreement in terms of the number of involved segments (NIS) in disc herniation and epicenter measurements collected using MDCT and MRI. The interobserver agreement rates upon evaluation of disc morphology by the three radiologists were in fair to moderate agreement (k = 0.39-0.53 for MDCT images; k = 0.45-0.56 for MRIs). When the disc morphology was categorized into two and four grades, the inter-modality agreement rates were moderate (k-value, 0.59) and substantial (k-value, 0.66), respectively. The inter-modality agreements for evaluations of the NIS (k-value, 0.78) and the epicenter (k-value, 0.79) were substantial. Also, the interobserver agreements for the NIS (CT; k-value, 0.85 and MRI; k-value, 0.88) and epicenter (CT; k-value, 0.74 and MRI; k-value, 0.70) evaluations by two readers were substantial. MDCT tended to underestimate the extent of herniated disc lesions compared with MRI. Multidetector-row computed tomography and MRI showed a moderate-to-substantial degree of inter-modality agreement for the assessment of herniated cervical discs. MDCT images have a tendency to underestimate the anterior/posterior extent of the herniated disc compared with MRI.

  16. Underestimation of Project Costs

    Science.gov (United States)

    Jones, Harry W.

    2015-01-01

    Large projects almost always exceed their budgets. Estimating cost is difficult and estimated costs are usually too low. Three different reasons are suggested: bad luck, overoptimism, and deliberate underestimation. Project management can usually point to project difficulty and complexity, technical uncertainty, stakeholder conflicts, scope changes, unforeseen events, and other not really unpredictable bad luck. Project planning is usually over-optimistic, so the likelihood and impact of bad luck is systematically underestimated. Project plans reflect optimism and hope for success in a supposedly unique new effort rather than rational expectations based on historical data. Past project problems are claimed to be irrelevant because "This time it's different." Some bad luck is inevitable and reasonable optimism is understandable, but deliberate deception must be condemned. In a competitive environment, project planners and advocates often deliberately underestimate costs to help gain project approval and funding. Project benefits, cost savings, and probability of success are exaggerated and key risks ignored. Project advocates have incentives to distort information and conceal difficulties from project approvers. One naively suggested cure is more openness, honesty, and group adherence to shared overall goals. A more realistic alternative is threatening overrun projects with cancellation. Neither approach seems to solve the problem. A better method to avoid the delusions of over-optimism and the deceptions of biased advocacy is to base the project cost estimate on the actual costs of a large group of similar projects. Over optimism and deception can continue beyond the planning phase and into project execution. Hard milestones based on verified tests and demonstrations can provide a reality check.

  17. Incomplete fissures in severe emphysematous patients evaluated with MDCT: Incidence and interobserver agreement among radiologists and pneumologists

    Energy Technology Data Exchange (ETDEWEB)

    Koenigkam-Santos, Marcel, E-mail: marcelk46@yahoo.com.br [Department of Diagnostic and Interventional Radiology, University of Heidelberg, Neuenheimer Feld 110, 69120 Heidelberg (Germany); Chest Clinic (Thoraxklinik), University of Heidelberg, Amalienstr. 5,69126 Heidelberg (Germany); Department of Radiology, University Hospital of the School of Medicine of Ribeirao Preto - University of Sao Paulo, Av. Bandeirantes 3900, Campus Universitario Monte Alegre, 14048 900 Ribeirao Preto, SP (Brazil); Puderbach, Michael [Department of Diagnostic and Interventional Radiology, University of Heidelberg, Neuenheimer Feld 110, 69120 Heidelberg (Germany); Chest Clinic (Thoraxklinik), University of Heidelberg, Amalienstr. 5,69126 Heidelberg (Germany); Gompelmann, Daniela; Eberhardt, Ralf; Herth, Felix [Chest Clinic (Thoraxklinik), University of Heidelberg, Amalienstr. 5,69126 Heidelberg (Germany); Kauczor, Hans-Ulrich [Department of Diagnostic and Interventional Radiology, University of Heidelberg, Neuenheimer Feld 110, 69120 Heidelberg (Germany); Heussel, Claus Peter [Department of Diagnostic and Interventional Radiology, University of Heidelberg, Neuenheimer Feld 110, 69120 Heidelberg (Germany); Chest Clinic (Thoraxklinik), University of Heidelberg, Amalienstr. 5,69126 Heidelberg (Germany)

    2012-12-15

    Objective: Pulmonary fissures completeness predicts efficacy in endobronchial valves (EBV) implantation, a new lobar volume reduction therapy for severe emphysematous patients. We assessed the incidence of incomplete fissures and the interobserver agreement in its evaluation with MDCT, in severe emphysematous patients prior to EBV implantation. Materials and Methods: Volumetric thin-section CT scans of 35 patients (CODP GOLD 3/4, heterogeneous emphysema) were retrospectively reviewed by 2 pneumologists, 1 general and 2 experienced chest radiologists, independently and blinded for treatment outcome, and the pulmonary fissures were classified as either complete or incomplete. Interobserver agreement was assessed with Kappa index (KI). Results: Agreement between all readers for the left oblique, right oblique and horizontal fissure was, respectively, moderate (KI = 0.53), fair (KI = 0.37) and moderate (KI = 0.42). Highest agreement (99/105 fissures) was observed among experienced radiologists, being for left oblique, right oblique and horizontal, respectively, almost perfect (KI = 0.79), perfect (KI = 1.0) and moderate (KI = 0.52). These 2 reviewers found that all of 35 patients had at least one incomplete fissure, with a proportion of incomplete fissures assigned as 74/65%, 85/85% and 91/88%, respectively for the left oblique, right oblique and horizontal fissures. Conclusions: Pneumologists and radiologists agreed fairly to moderately in fissures analysis, while the experienced chest radiologists reached the highest clinically adequate agreement of 94%. We believe that clinical routine visual analysis of the fissures integrity can be done with a good degree of confidence in MDCT images, and experienced readers might be required. Also, a higher than expected incidence of incomplete fissures was described in our studied population.

  18. Incomplete fissures in severe emphysematous patients evaluated with MDCT: Incidence and interobserver agreement among radiologists and pneumologists

    International Nuclear Information System (INIS)

    Koenigkam-Santos, Marcel; Puderbach, Michael; Gompelmann, Daniela; Eberhardt, Ralf; Herth, Felix; Kauczor, Hans-Ulrich; Heussel, Claus Peter

    2012-01-01

    Objective: Pulmonary fissures completeness predicts efficacy in endobronchial valves (EBV) implantation, a new lobar volume reduction therapy for severe emphysematous patients. We assessed the incidence of incomplete fissures and the interobserver agreement in its evaluation with MDCT, in severe emphysematous patients prior to EBV implantation. Materials and Methods: Volumetric thin-section CT scans of 35 patients (CODP GOLD 3/4, heterogeneous emphysema) were retrospectively reviewed by 2 pneumologists, 1 general and 2 experienced chest radiologists, independently and blinded for treatment outcome, and the pulmonary fissures were classified as either complete or incomplete. Interobserver agreement was assessed with Kappa index (KI). Results: Agreement between all readers for the left oblique, right oblique and horizontal fissure was, respectively, moderate (KI = 0.53), fair (KI = 0.37) and moderate (KI = 0.42). Highest agreement (99/105 fissures) was observed among experienced radiologists, being for left oblique, right oblique and horizontal, respectively, almost perfect (KI = 0.79), perfect (KI = 1.0) and moderate (KI = 0.52). These 2 reviewers found that all of 35 patients had at least one incomplete fissure, with a proportion of incomplete fissures assigned as 74/65%, 85/85% and 91/88%, respectively for the left oblique, right oblique and horizontal fissures. Conclusions: Pneumologists and radiologists agreed fairly to moderately in fissures analysis, while the experienced chest radiologists reached the highest clinically adequate agreement of 94%. We believe that clinical routine visual analysis of the fissures integrity can be done with a good degree of confidence in MDCT images, and experienced readers might be required. Also, a higher than expected incidence of incomplete fissures was described in our studied population.

  19. Risk of contrast-medium-induced nephropathy in high-risk patients undergoing MDCT--a pooled analysis of two randomized trials

    DEFF Research Database (Denmark)

    Thomsen, Henrik S; Morcos, Sameh K

    2009-01-01

    of the LOCM were also observed in patients with GFR contrast agents in patients with moderate-to-severe renal insufficiency, the risk of significant CIN seems to be low. The IOCM iodixanol caused a higher rate of CIN than the LOCM......The incidence of contrast-medium-induced nephropathy (CIN) following intravenous (IV) CM administration of contrast media to renally impaired patients undergoing multidetector computed tomography (MDCT) is not well characterized. Our objective was to investigate the incidence of CIN in patients...... with glomerular filtration rate (GFR) contrast-enhanced MDCT examinations and to compare the rates of CIN following the IV administration of low-osmolar contrast media (LOCM, iopamidol and iomeprol) and an iso-osmolar contrast medium (IOCM, iodixanol). A total of 301 adult patients...

  20. Effect of Low-Dose MDCT and Iterative Reconstruction on Trabecular Bone Microstructure Assessment.

    Science.gov (United States)

    Kopp, Felix K; Holzapfel, Konstantin; Baum, Thomas; Nasirudin, Radin A; Mei, Kai; Garcia, Eduardo G; Burgkart, Rainer; Rummeny, Ernst J; Kirschke, Jan S; Noël, Peter B

    2016-01-01

    We investigated the effects of low-dose multi detector computed tomography (MDCT) in combination with statistical iterative reconstruction algorithms on trabecular bone microstructure parameters. Twelve donated vertebrae were scanned with the routine radiation exposure used in our department (standard-dose) and a low-dose protocol. Reconstructions were performed with filtered backprojection (FBP) and maximum-likelihood based statistical iterative reconstruction (SIR). Trabecular bone microstructure parameters were assessed and statistically compared for each reconstruction. Moreover, fracture loads of the vertebrae were biomechanically determined and correlated to the assessed microstructure parameters. Trabecular bone microstructure parameters based on low-dose MDCT and SIR significantly correlated with vertebral bone strength. There was no significant difference between microstructure parameters calculated on low-dose SIR and standard-dose FBP images. However, the results revealed a strong dependency on the regularization strength applied during SIR. It was observed that stronger regularization might corrupt the microstructure analysis, because the trabecular structure is a very small detail that might get lost during the regularization process. As a consequence, the introduction of SIR for trabecular bone microstructure analysis requires a specific optimization of the regularization parameters. Moreover, in comparison to other approaches, superior noise-resolution trade-offs can be found with the proposed methods.

  1. Radiological profile of anemia on unenhanced MDCT of the thorax

    International Nuclear Information System (INIS)

    Kamel, Ehab M.; Rizzo, Elena; Duran, Rafael; Goncalves-Matoso, Vasco; Schnyder, Pierre; Duchosal, Michel A.; Qanadli, Salah D.

    2008-01-01

    Our aim was to investigate the diagnostic value of unenhanced MDCT in anemic patients. Fifty consecutive patients with proven anemia and 50 nonanemic matched group for age, sex and body mass index were evaluated. In either group, hemoglobin levels were assessed no more than 24 h from an unenhanced CT of the thorax. For each patient, the presence of a hyperattenuating aortic wall (aortic ring sign) and/or dense interventricular septum (subjective parameters) were identified by two radiologists who were blinded to the laboratory findings. Furthermore, the aortic CT attenuation values (objective parameter) were also obtained and correlated with the hemoglobin levels. The sensitivity and specificity in detecting anemia were calculated for each variable, and ROC analysis was generated for subjective and objective parameters. Subjective image analysis revealed that the aortic ring sign was more sensitive than the interventricular septum sign for anemia detection (84% vs. 72%), whereas this latter sign was more specific (100% vs. 92%). A good correlation (r=0.60) was observed between the aortic CT attenuation values and the hemoglobin levels in the whole study population. Using a threshold of ≤35 HU for anemia diagnosis, the sensitivity and specificity of aortic CT attenuation value were 84% and 94%, respectively, with the largest area under the curve (0.89) among all diagnostic criteria. However, the best trade-off between sensitivity (80%) and specificity (100%) was obtained from combining both subjective and objective analysis. Interpreting anemia upon unnenhanced MDCT of the thorax is quite feasible. A diagnostic approach that considers both subjective and objective analysis offers the best trade-off between sensitivity and specificity. (orig.)

  2. Abdominal Hernias, Giant Colon Diverticulum, GIST, Intestinal Pneumatosis, Colon Ischemia, Cold Intussusception, Gallstone Ileus, and Foreign Bodies: Our Experience and Literature Review of Incidental Gastrointestinal MDCT Findings

    OpenAIRE

    Di Grezia, G.; Gatta, G.; Rella, R.; Donatello, D.; Falco, G.; Grassi, R.; Grassi, R.

    2017-01-01

    Incidental gastrointestinal findings are commonly detected on MDCT exams performed for various medical indications. This review describes the radiological MDCT spectrum of appearances already present in the past literature and in today’s experience of several gastrointestinal acute conditions such as abdominal hernia, giant colon diverticulum, GIST, intestinal pneumatosis, colon ischemia, cold intussusception, gallstone ileus, and foreign bodies which can require medical and surgical interven...

  3. Feasibility and diagnostic accuracy of a low radiation exposure protocol for prospective ECG-triggering coronary MDCT angiography

    International Nuclear Information System (INIS)

    Pontone, G.; Andreini, D.; Bartorelli, A.L.; Bertella, E.; Mushtaq, S.; Foti, C.; Formenti, A.; Chiappa, L.; Annoni, A.; Cortinovis, S.; Baggiano, A.; Conte, E.; Bovis, F.; Veglia, F.; Ballerini, G.; Agostoni, P.; Fiorentini, C.; Pepi, M.

    2012-01-01

    Aim: To compare the feasibility, accuracy, and effective radiation dose (ED) of multidetector computed tomography (MDCT) in the detection of coronary artery disease using a combined ED-saving strategy including prospective electrocardiogram (ECG) triggering with a short x-ray window and a body mass index (BMI)-adapted imaging protocol using adaptive statistical iterative reconstruction (ASIR; group 1), in comparison with a prospective ECG triggering strategy alone (group 2). Materials and methods: One hundred and seventy patients scheduled for invasive coronary angiography (ICA) were evaluated. Fourteen patients were not eligible for MDCT. The remaining 156 patients were randomized to group 1 (78 patients) and group 2 (78 patients). Eight and 11 patients in groups 1 and 2, respectively, were excluded after randomization because the patients’ heart rates were >65 beats/min. MDCT images were assessed for feasibility, signal-to-noise ration (SNR), and contrast-to-noise ratio (CNR), accuracy in detection of coronary stenoses >50% versus ICA and for ED. Results: The feasibility, SNR, CNR, accuracy in a segment-based and patient-based model were similar in both groups (97 versus 95%, 14.5 ± 3.9 versus 14.2 ± 4.1, 16 ± 4.6 versus 16.5 ± 4.4, 95 versus 94% and 97 versus 99%, respectively). The ED in group 1 was 72% lower than in group 2 (2.1 ± 1.2 versus 7.5 ± 1.8 mSv, respectively; p < 0.01). Conclusions: The use of a multi-parametric ED saving protocol results in a significant reduction in ED without a negative impact on accuracy.

  4. Feasibility and diagnostic accuracy of a low radiation exposure protocol for prospective ECG-triggering coronary MDCT angiography

    Energy Technology Data Exchange (ETDEWEB)

    Pontone, G., E-mail: gianluca.pontone@ccfm.it [Centro Cardiologico Monzino, IRCCS, Milan (Italy); Andreini, D. [Centro Cardiologico Monzino, IRCCS, Milan (Italy); Bartorelli, A.L. [Centro Cardiologico Monzino, IRCCS, Milan (Italy); Department of Cardiovascular Sciences, University of Milan, Milan (Italy); Bertella, E.; Mushtaq, S.; Foti, C.; Formenti, A.; Chiappa, L.; Annoni, A.; Cortinovis, S.; Baggiano, A.; Conte, E.; Bovis, F.; Veglia, F.; Ballerini, G. [Centro Cardiologico Monzino, IRCCS, Milan (Italy); Agostoni, P.; Fiorentini, C. [Centro Cardiologico Monzino, IRCCS, Milan (Italy); Department of Cardiovascular Sciences, University of Milan, Milan (Italy); Pepi, M. [Centro Cardiologico Monzino, IRCCS, Milan (Italy)

    2012-03-15

    Aim: To compare the feasibility, accuracy, and effective radiation dose (ED) of multidetector computed tomography (MDCT) in the detection of coronary artery disease using a combined ED-saving strategy including prospective electrocardiogram (ECG) triggering with a short x-ray window and a body mass index (BMI)-adapted imaging protocol using adaptive statistical iterative reconstruction (ASIR; group 1), in comparison with a prospective ECG triggering strategy alone (group 2). Materials and methods: One hundred and seventy patients scheduled for invasive coronary angiography (ICA) were evaluated. Fourteen patients were not eligible for MDCT. The remaining 156 patients were randomized to group 1 (78 patients) and group 2 (78 patients). Eight and 11 patients in groups 1 and 2, respectively, were excluded after randomization because the patients' heart rates were >65 beats/min. MDCT images were assessed for feasibility, signal-to-noise ration (SNR), and contrast-to-noise ratio (CNR), accuracy in detection of coronary stenoses >50% versus ICA and for ED. Results: The feasibility, SNR, CNR, accuracy in a segment-based and patient-based model were similar in both groups (97 versus 95%, 14.5 {+-} 3.9 versus 14.2 {+-} 4.1, 16 {+-} 4.6 versus 16.5 {+-} 4.4, 95 versus 94% and 97 versus 99%, respectively). The ED in group 1 was 72% lower than in group 2 (2.1 {+-} 1.2 versus 7.5 {+-} 1.8 mSv, respectively; p < 0.01). Conclusions: The use of a multi-parametric ED saving protocol results in a significant reduction in ED without a negative impact on accuracy.

  5. Are hepatic portal venous system components distributed equally to the liver? A MDCT study

    International Nuclear Information System (INIS)

    Incedayi, M.; Aribal, S.; Sivrioglu, A.; Sonmez, G.; Ozturk, E.; Yalcin, B.; Basekim, C.

    2012-01-01

    Full text: Objective: We aimed to evaluate the relationships between the splenic index, right and left hepatic lobe volumes, diameters of splenic vein (SV), superior mesenteric vein (SMV) and the portal vein (PV) by Multidetector Computerized Tomography (MDCT). We also investigated indirect signs of portal venous flow pattern using these parameters. Material and method: Following their contrast thoracoabdominal and abdominal 64-MDCT examinations, the images of 100 cases (61 males and 39 females) were evaluated retrospectively. The patients who were included in the study ranged from age 20 to 88 (mean age: 41,78). For each case, the splenic index, total hepatic volume, left and right hepatic volumes were calculated on the post-contrast portal venous phase (50th sec) images. Cases without any known liver and spleen diseases were included in the study. Spearman and Pearson's correlation tests were carried out with the purpose of determining the relationships between the variables. Results: A statistically significant relationship between the splenic index and left hepatic lobe volume and total volume was demonstrated (p=0.001). Positive correlations between the left hepatic lobe volume and splenic index (r=0.55) and between the right hepatic lobe volume and splenic index (r=0.32) were also exhibited. However, the correlation between the left hepatic lobe volume and the splenic index was relatively stronger compared to the correlation between the right hepatic lobe volume and the splenic index (r=0.55 versus r= 0.32). Between the diameter of the SMV and right hepatic lobe volume a statistically significant relation was demonstrated (p<0.0001), and according to Pearson's correlation analysis, a positive correlation of medium strength (r=0.36) was observed. Conclusion: In our study, the MDCT findings revealed statistically significant relations between the splenic index and the left lobe volume and between the diameter of the SMV and the right lobe volume. Information

  6. Usefulness of multidetector-row CT (MDCT) for the diagnosis of non-occlusive mesenteric ischemia (NOMI): Assessment of morphology and diameter of the superior mesenteric artery (SMA) on multi-planar reconstructed (MPR) images

    International Nuclear Information System (INIS)

    Woodhams, Reiko; Nishimaki, Hiroshi; Fujii, Kaoru; Kakita, Satoko; Hayakawa, Kazushige

    2010-01-01

    Objective: The purpose of this study was to assess the efficacy of multidetector-row CT (MDCT) for the diagnosis of non-occlusive mesenteric ischemia (NOMI) by analyzing morphology and diameter of superior mesenteric artery (SMA). We assessed whether MDCT was as useful as angiography for the diagnosis of NOMI. Materials and methods: Four patients who were diagnosed with NOMI were retrospectively analyzed. All patients had 8-row MDCT followed by laparotomy. Two of them underwent angiography after MDCT. The morphology and diameter of SMA of these cases was analyzed on multi-planar reconstructed (MPR) images. The mean diameter of SMA of NOMI cases was compared to that of 13 control cases. Results: MPR images of all NOMI cases showed irregular narrowing of the SMA, spasm of the arcades of SMA, and poor demonstration of intramural vessels. MPR images of two patients who had angiography were concordant with their angiograms. The mean diameter of SMA of NOMI patients was 3.4 ± 1.1 mm, which was statistically smaller than that of 13 control patients, 6.0 ± 1.5 mm (P < 0.05, Wilcoxon rank sum tests). Conclusion: Angiography has been recognized essential for the diagnosis of NOMI. This study shows the possibility of MDCT to be an equivalently useful modality compared to angiography for the diagnosis of NOMI by interpreting morphologic appearance and diameter of SMA. Introduction of MDCT in the decision tree of NOMI treatment may bring the benefit of prompt diagnosis and subsequent early and efficient initiation of therapy, which may improve the mortality.

  7. Abdominal 64-MDCT for suspected appendicitis: the use of oral and IV contrast material versus IV contrast material only.

    Science.gov (United States)

    Anderson, Stephan W; Soto, Jorge A; Lucey, Brian C; Ozonoff, Al; Jordan, Jacqueline D; Ratevosian, Jirair; Ulrich, Andrew S; Rathlev, Niels K; Mitchell, Patricia M; Rebholz, Casey; Feldman, James A; Rhea, James T

    2009-11-01

    The objective of our study was to compare the diagnostic accuracy of IV contrast-enhanced 64-MDCT with and without the use of oral contrast material in diagnosing appendicitis in patients with abdominal pain. We conducted a randomized trial of a convenience sample of adult patients presenting to an urban academic emergency department with acute nontraumatic abdominal pain and clinical suspicion of appendicitis, diverticulitis, or small-bowel obstruction. Patients were enrolled between 8 am and 11 pm when research assistants were present. Consenting subjects were randomized into one of two groups: Group 1 subjects underwent 64-MDCT performed with oral and IV contrast media and group 2 subjects underwent 64-MDCT performed solely with IV contrast material. Three expert radiologists independently reviewed the CT examinations, evaluating for the presence of appendicitis. Each radiologist interpreted 202 examinations, ensuring that each examination was interpreted by two radiologists. Individual reader performance and a combined interpretation performance of the two readers assigned to each case were calculated. In cases of disagreement, the third reader was asked to deliver a tiebreaker interpretation to be used to calculate the combined reader performance. Final outcome was based on operative, clinical, and follow-up data. We compared radiologic diagnoses with clinical outcomes to calculate the diagnostic accuracy of CT in both groups. Of the 303 patients enrolled, 151 patients (50%) were randomized to group 1 and the remaining 152 (50%) were randomized to group 2. The combined reader performance for the diagnosis of appendicitis in group 1 was a sensitivity of 100% (95% CI, 76.8-100%) and specificity of 97.1% (95% CI, 92.7-99.2%). The performance in group 2 was a sensitivity of 100% (73.5-100%) and specificity of 97.1% (92.9-99.2%). Patients presenting with nontraumatic abdominal pain imaged using 64-MDCT with isotropic reformations had similar characteristics for the

  8. Quantitative right and left ventricular functional analysis during gated whole-chest MDCT: A feasibility study comparing automatic segmentation to semi-manual contouring

    International Nuclear Information System (INIS)

    Coche, Emmanuel; Walker, Matthew J.; Zech, Francis; Crombrugghe, Rodolphe de; Vlassenbroek, Alain

    2010-01-01

    Purpose: To evaluate the feasibility of an automatic, whole-heart segmentation algorithm for measuring global heart function from gated, whole-chest MDCT images. Material and methods: 15 patients with suspicion of PE underwent whole-chest contrast-enhanced MDCT with retrospective ECG synchronization. Two observers computed right and left ventricular functional indices using a semi-manual and an automatic whole-heart segmentation algorithm. The two techniques were compared using Bland-Altman analysis and paired Student's t-test. Measurement reproducibility was calculated using intraclass correlation coefficient. Results: Ventricular analysis with automatic segmentation was successful in 13/15 (86%) and in 15/15 (100%) patients for the right ventricle and left ventricle, respectively. Reproducibility of measurements for both ventricles was perfect (ICC: 1.00) and very good for automatic and semi-manual measurements, respectively. Ventricular volumes and functional indices except right ventricular ejection fraction obtained from the automatic method were significantly higher for the RV compared to the semi-manual methods. Conclusions: The automatic, whole-heart segmentation algorithm enabled highly reproducible global heart function to be rapidly obtained in patients undergoing gated whole-chest MDCT for assessment of acute chest pain with suspicion of pulmonary embolism.

  9. Influence of radiation dose and reconstruction algorithm in MDCT assessment of airway wall thickness: A phantom study

    International Nuclear Information System (INIS)

    Gomez-Cardona, Daniel; Nagle, Scott K.; Li, Ke; Chen, Guang-Hong; Robinson, Terry E.

    2015-01-01

    Purpose: Wall thickness (WT) is an airway feature of great interest for the assessment of morphological changes in the lung parenchyma. Multidetector computed tomography (MDCT) has recently been used to evaluate airway WT, but the potential risk of radiation-induced carcinogenesis—particularly in younger patients—might limit a wider use of this imaging method in clinical practice. The recent commercial implementation of the statistical model-based iterative reconstruction (MBIR) algorithm, instead of the conventional filtered back projection (FBP) algorithm, has enabled considerable radiation dose reduction in many other clinical applications of MDCT. The purpose of this work was to study the impact of radiation dose and MBIR in the MDCT assessment of airway WT. Methods: An airway phantom was scanned using a clinical MDCT system (Discovery CT750 HD, GE Healthcare) at 4 kV levels and 5 mAs levels. Both FBP and a commercial implementation of MBIR (Veo TM , GE Healthcare) were used to reconstruct CT images of the airways. For each kV–mAs combination and each reconstruction algorithm, the contrast-to-noise ratio (CNR) of the airways was measured, and the WT of each airway was measured and compared with the nominal value; the relative bias and the angular standard deviation in the measured WT were calculated. For each airway and reconstruction algorithm, the overall performance of WT quantification across all of the 20 kV–mAs combinations was quantified by the sum of squares (SSQs) of the difference between the measured and nominal WT values. Finally, the particular kV–mAs combination and reconstruction algorithm that minimized radiation dose while still achieving a reference WT quantification accuracy level was chosen as the optimal acquisition and reconstruction settings. Results: The wall thicknesses of seven airways of different sizes were analyzed in the study. Compared with FBP, MBIR improved the CNR of the airways, particularly at low radiation dose

  10. Influence of radiation dose and reconstruction algorithm in MDCT assessment of airway wall thickness: A phantom study

    Energy Technology Data Exchange (ETDEWEB)

    Gomez-Cardona, Daniel [Department of Medical Physics, University of Wisconsin-Madison School of Medicine and Public Health, 1111 Highland Avenue, Madison, Wisconsin 53705 (United States); Nagle, Scott K. [Department of Medical Physics, University of Wisconsin-Madison School of Medicine and Public Health, 1111 Highland Avenue, Madison, Wisconsin 53705 (United States); Department of Radiology, University of Wisconsin-Madison School of Medicine and Public Health, 600 Highland Avenue, Madison, Wisconsin 53792 (United States); Department of Pediatrics, University of Wisconsin-Madison School of Medicine and Public Health, 600 Highland Avenue, Madison, Wisconsin 53792 (United States); Li, Ke; Chen, Guang-Hong, E-mail: gchen7@wisc.edu [Department of Medical Physics, University of Wisconsin-Madison School of Medicine and Public Health, 1111 Highland Avenue, Madison, Wisconsin 53705 (United States); Department of Radiology, University of Wisconsin-Madison School of Medicine and Public Health, 600 Highland Avenue, Madison, Wisconsin 53792 (United States); Robinson, Terry E. [Department of Pediatrics, Stanford School of Medicine, 770 Welch Road, Palo Alto, California 94304 (United States)

    2015-10-15

    Purpose: Wall thickness (WT) is an airway feature of great interest for the assessment of morphological changes in the lung parenchyma. Multidetector computed tomography (MDCT) has recently been used to evaluate airway WT, but the potential risk of radiation-induced carcinogenesis—particularly in younger patients—might limit a wider use of this imaging method in clinical practice. The recent commercial implementation of the statistical model-based iterative reconstruction (MBIR) algorithm, instead of the conventional filtered back projection (FBP) algorithm, has enabled considerable radiation dose reduction in many other clinical applications of MDCT. The purpose of this work was to study the impact of radiation dose and MBIR in the MDCT assessment of airway WT. Methods: An airway phantom was scanned using a clinical MDCT system (Discovery CT750 HD, GE Healthcare) at 4 kV levels and 5 mAs levels. Both FBP and a commercial implementation of MBIR (Veo{sup TM}, GE Healthcare) were used to reconstruct CT images of the airways. For each kV–mAs combination and each reconstruction algorithm, the contrast-to-noise ratio (CNR) of the airways was measured, and the WT of each airway was measured and compared with the nominal value; the relative bias and the angular standard deviation in the measured WT were calculated. For each airway and reconstruction algorithm, the overall performance of WT quantification across all of the 20 kV–mAs combinations was quantified by the sum of squares (SSQs) of the difference between the measured and nominal WT values. Finally, the particular kV–mAs combination and reconstruction algorithm that minimized radiation dose while still achieving a reference WT quantification accuracy level was chosen as the optimal acquisition and reconstruction settings. Results: The wall thicknesses of seven airways of different sizes were analyzed in the study. Compared with FBP, MBIR improved the CNR of the airways, particularly at low radiation dose

  11. Pulmonary 64-MDCT angiography with 50 mL of iodinated contrast material in an unselected patient population: a feasible protocol

    Energy Technology Data Exchange (ETDEWEB)

    Trad, Henrique Simao; Boasquevisque, Gustavo Santos; Giacometti, Tiago Rangon; Trad, Catherine Yang; Zoghbi Neto, Orlando Salomao; Trad, Clovis Simao, E-mail: hsimtrad@gmail.com [Central de Diagnostico Ribeirao Preto (CEDIRP), Ribeirao Preto, SP (Brazil)

    2016-03-15

    Objective: To propose a protocol for pulmonary angiography using 64-slice multidetector computed tomography (64-MDCT) with 50 mL of iodinated contrast material, in an unselected patient population, as well as to evaluate vascular enhancement and image quality. Materials and methods: We evaluated 29 patients (22-86 years of age). The body mass index ranged from 19.0 kg/m{sup 2} to 41.8 kg/m{sup 2}. Patients underwent pulmonary CT angiography in a 64-MDCT scanner, receiving 50 mL of iodinated contrast material via venous access at a rate of 4.5 mL/s. Bolus tracking was applied in the superior vena cava. Two experienced radiologists assessed image quality and vascular enhancement. Results: The mean density was 382 Hounsfield units (HU) for the pulmonary trunk; 379 and 377 HU for the right and left main pulmonary arteries, respectively; and 346 and 364 HU for the right and left inferior pulmonary arteries, respectively. In all patients, subsegmental arteries were analyzed. There were streak artifacts from contrast material in the superior vena cava in all patients. However, those artifacts did not impair the image analysis. Conclusion: Our findings suggest that pulmonary angiography using 64-MDCT with 50 mL of iodinated contrast can produce high quality images in unselected patient populations. (author)

  12. Multidetector computed tomography (MDCT) evaluation of myocardial viability: intraindividual comparison of monomeric vs. dimeric contrast media in a rabbit model

    Energy Technology Data Exchange (ETDEWEB)

    Mahnken, Andreas H. [RWTH Aachen University, Department of Diagnostic Radiology, Aachen (Germany)]|[RWTH Aachen University, Applied Medical Engineering, Helmholtz Institute, Aachen (Germany)]|[University Hospital, RWTH Aachen University, Department of Diagnostic Radiology, Aachen (Germany); Jost, Gregor; Sieber, Martin; Seidensticker, Peter R.; Pietsch, Hubertus [Bayer-Schering Pharma AG, Berlin (Germany); Bruners, Philipp [RWTH Aachen University, Department of Diagnostic Radiology, Aachen (Germany)]|[RWTH Aachen University, Applied Medical Engineering, Helmholtz Institute, Aachen (Germany); Guenther, Rolf W. [RWTH Aachen University, Department of Diagnostic Radiology, Aachen (Germany)

    2009-02-15

    To evaluate the influence of different types of iodinated contrast media on the assessment of myocardial viability, acute myocardial infarction (MI) was surgically induced in six rabbits. Over a period of 45 min, contrast-enhanced cardiac MDCT (64 x 0.6 mm, 80 kV, 680mAs{sub eff.}) was repeatedly performed using a contrast medium dose of 600 mg iodine/kg body weight. Animals received randomized iopromide 300 and iodixanol 320, respectively. Attenuation values of healthy and infarcted myocardium were measured. The size of MI was computed and compared with nitroblue tetrazolium (NBT)-stained specimen. The highest attenuation differences between infarcted and healthy myocardium occurred during the arterial phase with 140.0{+-}3.5 HU and 141.0{+-}2.2 HU for iopromide and iodixanol, respectively. For iodixanol the highest attenuation difference on delayed contrast-enhanced images was achieved 3 min post injection (73.5 HU). A slightly higher attenuation difference was observed for iopromide 6 min after contrast medium injection (82.2 HU), although not statistically significant (p=0.6437). Mean infarct volume as measured by NBT staining was 33.5%{+-}13.6%. There was an excellent agreement of infarct sizes among NBT-, iopromide- and iodixanol-enhanced MDCT with concordance-correlation coefficients ranging from {rho}{sub (c)=} 0.9928-0.9982. Iopromide and iodixanol both allow a reliable assessment of MI with delayed contrast-enhanced MDCT. (orig.)

  13. Investigation of airways using MDCT for visual and quantitative assessment in COPD patients

    Directory of Open Access Journals (Sweden)

    Pierre-Yves Brillet

    2008-03-01

    Full Text Available Pierre-Yves Brillet1, Catalin I Fetita2, Amaury Saragaglia2, Anne-Laure Brun3, Catherine Beigelman-Aubry3, Françoise Prêteux2, Philippe A Grenier31Department of Radiology, Avicenne Hospital, Assistance Publique–Hôpitaux de Paris, Université Léonard de Vinci–Paris Nord, EA 2361, Bobigny, France; 2ARTEMIS Department, Institut National des Télécommunications, Université Paris V, Evry, France; 3Department of Radiology, Pitié-Salpêtrière Hospital, Assistance Publique–Hôpitaux de Paris, Université Pierre et Marie Curie, Paris, FranceAbstract: Multidetector computed tomography (MDCT acquisition during a single breath hold using thin collimation provides high resolution volumetric data set permitting multiplanar and three dimensional reconstruction of the proximal airways. In chronic obstructive pulmonary disease (COPD patients, this technique provides an accurate assessment of bronchial wall thickening, tracheobronchial deformation, outpouchings reflecting dilatation of the submucous glands, tracheobronchomalacia, and expiratory air trapping. New software developed to segment adequately the lumen and walls of the airways on MDCT scans allows quantitative assessment of the airway dimensions which has shown to be reliable in clinical practice. This technique can become important in longitudinal studies of the pathogenesis of COPD, and in the assessment of therapeutic interventions.Keywords: COPD – tracheobronchial tree, multidetector CT – airway remodeling, tracheobronchomalacia

  14. Quantification of arterial plaque and lumen density with MDCT

    International Nuclear Information System (INIS)

    Paul, Narinder S.; Blobel, Joerg; Kashani, Hany; Rice, Murray; Ursani, Ali

    2010-01-01

    Purpose: This study aimed to derive a mathematical correction function in order to normalize the CT number measurements for small volume arterial plaque and small vessel mimicking objects, imaged with multidetector CT (MDCT). Methods: A commercially available calcium plaque phantom (QRM GmbH, Moehrendorf, Germany) and a custom built cardiovascular phantom were scanned with 320 and 64 MDCT scanners. The calcium hydroxyapatite plaque phantom contained objects 0.5-5.0 mm in diameter with known CT attenuation nominal values ranging 50-800 HU. The cardiovascular phantom contained vessel mimicking objects 1.0-5.0 mm in diameter with different contrast media. Both phantoms were scanned using clinical protocols for CT angiography and images were reconstructed with different filter kernels. The measured CT number (HU) and diameter of each object were analyzed on three clinical postprocessing workstations. From the resultant data, a mathematical formula was derived based on absorption function exp(-μ * d) to demonstrate the relation between measured CT numbers and object diameters. Results: The percentage reduction in measured CT number (HU) for the group of selected filter kernels, apparent during CT angiography, is dependent only on the object size (plaque or vessel diameter). The derived formula of the form 1-c * exp(-a * d b ) showed reduction in CT number for objects between 0.5 and 5 mm in diameter, with asymptote reaching background noise for small objects with diameters nearing the CT in-plane resolution (0.35 mm). No reduction was observed for the objects with diameters equal or larger than 5 mm. Conclusions: A clear mathematical relationship exists between object diameter and reduction in measured CT number in HU. This function is independent of exposure parameters and inherent attenuation properties of the objects studied. Future developments include the incorporation of this mathematical model function into quantification software in order to automatically

  15. Underestimating belief in climate change

    Science.gov (United States)

    Jost, John T.

    2018-03-01

    People are influenced by second-order beliefs — beliefs about the beliefs of others. New research finds that citizens in the US and China systematically underestimate popular support for taking action to curb climate change. Fortunately, they seem willing and able to correct their misperceptions.

  16. Effect of ultra-low doses, ASIR and MBIR on density and noise levels of MDCT images of dental implant sites.

    Science.gov (United States)

    Widmann, Gerlig; Al-Shawaf, Reema; Schullian, Peter; Al-Sadhan, Ra'ed; Hörmann, Romed; Al-Ekrish, Asma'a A

    2017-05-01

    Differences in noise and density values in MDCT images obtained using ultra-low doses with FBP, ASIR, and MBIR may possibly affect implant site density analysis. The aim of this study was to compare density and noise measurements recorded from dental implant sites using ultra-low doses combined with FBP, ASIR, and MBIR. Cadavers were scanned using a standard protocol and four low-dose protocols. Scans were reconstructed using FBP, ASIR-50, ASIR-100, and MBIR, and either a bone or standard reconstruction kernel. Density (mean Hounsfield units [HUs]) of alveolar bone and noise levels (mean standard deviation of HUs) was recorded from all datasets and measurements were compared by paired t tests and two-way ANOVA with repeated measures. Significant differences in density and noise were found between the reference dose/FBP protocol and almost all test combinations. Maximum mean differences in HU were 178.35 (bone kernel) and 273.74 (standard kernel), and in noise, were 243.73 (bone kernel) and 153.88 (standard kernel). Decreasing radiation dose increased density and noise regardless of reconstruction technique and kernel. The effect of reconstruction technique on density and noise depends on the reconstruction kernel used. • Ultra-low-dose MDCT protocols allowed more than 90 % reductions in dose. • Decreasing the dose generally increased density and noise. • Effect of IRT on density and noise varies with reconstruction kernel. • Accuracy of low-dose protocols for interpretation of bony anatomy not known. • Effect of low doses on accuracy of computer-aided design models unknown.

  17. Perfusion MDCT enables early detection of therapeutic response to antiangiogenic therapy.

    Science.gov (United States)

    Sabir, Adeel; Schor-Bardach, Rachel; Wilcox, Carol J; Rahmanuddin, Syed; Atkins, Michael B; Kruskal, Jonathan B; Signoretti, Sabina; Raptopoulos, Vassilios D; Goldberg, S Nahum

    2008-07-01

    The objective of our study was to determine whether perfusion CT can be used to detect early changes in therapeutic response to antiangiogenic therapy in an animal tumor model. Twenty-five rats implanted with R3230 mammary adenocarcinoma (diameter, 1.2-2.0 cm) randomly received 7.5 or 30 mg/kg of an antiangiogenic agent, sorafenib, by daily gavage for 4 (n = 4), 9 (n = 9), or 14 (n = 5) days. Seven untreated animals served as a control group. Perfusion MDCT was performed at days 0, 4, 9, and 14 with 0.4 mL of ioversol (350 mg/mL) and included four 5-mm slices covering the entire tumor volume. Changes in tumor growth were determined by volumetric analysis of CT data. Serial changes in tumor volume and blood flow were assessed and correlated with pathology findings. All control tumors grew larger (from 2.0 +/- 0.7 cm(3) at day 0 to 5.9 +/- 1.0 cm(3) at day 14), whereas all treated tumors shrank (from 2.5 +/- 1.1 to 2.1 +/- 1.0 cm(3)), with a statistically significant rate of growth or shrinkage in both groups (p histopathologic viability despite the fact that these tumors were shrinking in size from day 4 onward (day 4, 2.18 +/- 0.8 cm(3); day 9, 1.98 +/- 0.8 cm(3)). Perfusion MDCT can detect focal blood flow changes even when the tumor is shrinking, possibly indicating early reversal of tumor responsiveness to antiangiogenic therapy. Given that changes in tumor volume after antiangiogenic therapy do not necessarily correlate with true treatment response, physiologic imaging of tumor perfusion may be necessary.

  18. Comparison of neutral and positive enteral contrast media for MDCT enteroclysis

    International Nuclear Information System (INIS)

    Aiyappan, Senthil Kumar; Kalra, Naveen; Sandhu, Manavjit Singh; Kochhar, Rakesh; Wig, Jai Dev; Khandelwal, Niranjan

    2012-01-01

    Objective: To compare neutral and positive enteral contrast media for MDCT enteroclysis (MDCTE) in various small bowel diseases. Materials and methods: 40 patients with suspicion of small bowel diseases were divided randomly into two equal groups. In one group, water was used as neutral enteral contrast and in other group, 2% water soluble iodinated contrast was used as positive enteral contrast. All MDCTE were done on a 16-slice multidetector row CT unit. The findings of MDCTE were compared with the standards of reference. Results: There were 12 cases of abdominal tuberculosis (30%), 5 cases of bowel masses (12%), 4 cases of Crohn's disease (10%), 3 cases of small bowel adhesions (7%), 2 cases of midgut volvulus (5%), 2 cases of segmental enteritis (5%) and 12 of all cases (30%) were normal. There was no statistically significant difference between neutral and positive enteral contrast with regards to bowel distention, contrast reflux and evaluation of duodenum. Abnormal bowel wall enhancement was appreciated only with use of neutral enteral contrast (n = 12). Evaluation of ileocaecal junction was possible in all 20 patients (100%) with positive enteral contrast but in only 17 patients (85%) with neutral enteral contrast. Overall sensitivity and specificity of MDCTE with use of neutral contrast medium (100 and 88% respectively) was greater for evaluation of small bowel diseases, when compared to MDCTE using positive enteral contrast medium (92.8 and 83.3% respectively). Conclusions: Water is a good enteral contrast medium for MDCT enteroclysis examination and allows better evaluation of abnormal bowel wall enhancement. Ileocaecal junction evaluation is better with positive enteral contrast medium.

  19. Prediction of bone strength by μCT and MDCT-based finite-element-models: How much spatial resolution is needed?

    Energy Technology Data Exchange (ETDEWEB)

    Bauer, Jan S., E-mail: jsb@tum.de [Department of Radiology, Technische Universität München, Munich (Germany); Department of Radiology, University of California, San Francisco, CA (United States); Max Planck Institute for Extraterrestrial Physics, Garching (Germany); Sidorenko, Irina [Max Planck Institute for Extraterrestrial Physics, Garching (Germany); Mueller, Dirk [Department of Radiology, Universität Köln (Germany); Baum, Thomas [Department of Radiology, Technische Universität München, Munich (Germany); Department of Radiology, University of California, San Francisco, CA (United States); Max Planck Institute for Extraterrestrial Physics, Garching (Germany); Issever, Ahi Sema [Department of Radiology, University of California, San Francisco, CA (United States); Department of Radiology, Charite, Berlin (Germany); Eckstein, Felix [Institute of Anatomy and Musculoskeletal Research, Paracelsus Medical University, Salzburg (Austria); Rummeny, Ernst J. [Department of Radiology, Technische Universität München, Munich (Germany); Link, Thomas M. [Department of Radiology, University of California, San Francisco, CA (United States); Raeth, Christoph W. [Max Planck Institute for Extraterrestrial Physics, Garching (Germany)

    2014-01-15

    Objectives: Finite-element-models (FEM) are a promising technology to predict bone strength and fracture risk. Usually, the highest spatial resolution technically available is used, but this requires excessive computation time and memory in numerical simulations of large volumes. Thus, FEM were compared at decreasing resolutions with respect to local strain distribution and prediction of failure load to (1) validate MDCT-based FEM and to (2) optimize spatial resolution to save computation time. Materials and methods: 20 cylindrical trabecular bone specimens (diameter 12 mm, length 15–20 mm) were harvested from elderly formalin-fixed human thoracic spines. All specimens were examined by micro-CT (isotropic resolution 30 μm) and whole-body multi-row-detector computed tomography (MDCT, 250 μm × 250 μm × 500 μm). The resolution of all datasets was lowered in eight steps to ∼2000 μm × 2000 μm × 500 μm and FEM were calculated at all resolutions. Failure load was determined by biomechanical testing. Probability density functions of local micro-strains were compared in all datasets and correlations between FEM-based and biomechanically measured failure loads were determined. Results: The distribution of local micro-strains was similar for micro-CT and MDCT at comparable resolutions and showed a shift toward higher average values with decreasing resolution, corresponding to the increasing apparent trabecular thickness. Small micro-strains (ε{sub eff} < 0.005) could be calculated down to 250 μm × 250 μm × 500 μm. Biomechanically determined failure load showed significant correlations with all FEM, up to r = 0.85 and did not significantly change with lower resolution but decreased with high thresholds, due to loss of trabecular connectivity. Conclusion: When choosing connectivity-preserving thresholds, both micro-CT- and MDCT-based finite-element-models well predicted failure load and still accurately revealed the distribution of local micro-strains in

  20. Prediction of bone strength by μCT and MDCT-based finite-element-models: How much spatial resolution is needed?

    International Nuclear Information System (INIS)

    Bauer, Jan S.; Sidorenko, Irina; Mueller, Dirk; Baum, Thomas; Issever, Ahi Sema; Eckstein, Felix; Rummeny, Ernst J.; Link, Thomas M.; Raeth, Christoph W.

    2014-01-01

    Objectives: Finite-element-models (FEM) are a promising technology to predict bone strength and fracture risk. Usually, the highest spatial resolution technically available is used, but this requires excessive computation time and memory in numerical simulations of large volumes. Thus, FEM were compared at decreasing resolutions with respect to local strain distribution and prediction of failure load to (1) validate MDCT-based FEM and to (2) optimize spatial resolution to save computation time. Materials and methods: 20 cylindrical trabecular bone specimens (diameter 12 mm, length 15–20 mm) were harvested from elderly formalin-fixed human thoracic spines. All specimens were examined by micro-CT (isotropic resolution 30 μm) and whole-body multi-row-detector computed tomography (MDCT, 250 μm × 250 μm × 500 μm). The resolution of all datasets was lowered in eight steps to ∼2000 μm × 2000 μm × 500 μm and FEM were calculated at all resolutions. Failure load was determined by biomechanical testing. Probability density functions of local micro-strains were compared in all datasets and correlations between FEM-based and biomechanically measured failure loads were determined. Results: The distribution of local micro-strains was similar for micro-CT and MDCT at comparable resolutions and showed a shift toward higher average values with decreasing resolution, corresponding to the increasing apparent trabecular thickness. Small micro-strains (ε eff < 0.005) could be calculated down to 250 μm × 250 μm × 500 μm. Biomechanically determined failure load showed significant correlations with all FEM, up to r = 0.85 and did not significantly change with lower resolution but decreased with high thresholds, due to loss of trabecular connectivity. Conclusion: When choosing connectivity-preserving thresholds, both micro-CT- and MDCT-based finite-element-models well predicted failure load and still accurately revealed the distribution of local micro-strains in spatial

  1. Current role of MDCT in the diagnosis of coronary artery disease (2011). A clinical guideline of the Austrian Societies of Cardiology and Radiology; Aktueller Stellenwert der MSCTA in der Koronargefaessdiagnostik (2011). Klinischer Leitfaden der Oesterreichischen Gesellschaften fuer Kardiologie und Radiologie

    Energy Technology Data Exchange (ETDEWEB)

    Hergan, K. [Salzburger Landeskliniken, Paracelsus Medizinische Privatuniv. (Austria). Universitaetsinst. fuer Radiologie; Globits, S. [Landesklinikum St. Poelten (Austria). 3. Medizinische Abt./Kardiologie; Loewe, C. [Medizinische Univ. Wien (AT). Universitaetsklinik fuer Radiodiagnostik] (and others)

    2011-10-15

    The clinical guideline of the Austrian Societies for Cardiology and Radiology on the actual role of MDCT in the diagnosis of coronary artery diseases includes the following issues: CT calcium scoring; CT angiography (CTA) of the coronaries; actually recommended application of MDCR; generally inappropriate use of the technique for specific patients; radiation exposure; structural and organizational framework.

  2. The diagnostic value of direct CT arthrography using MDCT in the evaluation of acetabular labral tear: with arthroscopic correlation

    Energy Technology Data Exchange (ETDEWEB)

    Ha, Yong-Chan; Kim, Jae Yoon [Chung-Ang University College of Medicine, Department of Orthopaedic Surgery, Seoul (Korea, Republic of); Choi, Jung-Ah; Lee, Guen Young; Kang, Heung Sik [Seoul National University Bundang Hospital, Departments of Radiology, Seoul National University College of Medicine, 166 Gumi-ro, Bundang-gu, Seongnam (Korea, Republic of); Lee, Young-Kyun; Koo, Kyung-Hoi [Seoul National University Bundang Hospital, Orthopaedic Surgery, Seoul National University College of Medicine, Seongnam (Korea, Republic of)

    2013-05-15

    The purpose of this study was first, to determine the sensitivity, specificity, and accuracy of MDCT arthrography (CTA) for the diagnosis of acetabular labral tear and sulcus; second, to correlate tear types using the Lage classification system on CTA compared with the arthroscopic classification; and third, to correlate CTA localization with arthroscopic localization. Direct CTA was performed using 16- or 64-slice MDCT in 126 hips (124 patients) who had chronic groin pain and positive impingement test. Images were reviewed and evaluated by two experienced musculoskeletal radiologists preoperatively. CTA findings were compared with arthroscopic findings in 58 hips (56 patients) under consensus by two orthopedic surgeons. Forty-one of the 58 hips were diagnosed as labral tears on CT arthrography. Forty-three of the 58 hips were shown to have a labral tear on arthroscopy. Sensitivity, specificity, and accuracy for detecting labral tear and sulcus by CTA were 90.7%, 86.7%, and 89.7%, and 93.8%, 97.6% and 96.6% respectively for observer 1, and 90.7% and 80.0%, 87.9% and 87.5%, 95.2%, and 93.1 % respectively for observer 2. Thirty-five out of 41 hips (85%) that were diagnosed with labral tear on CTA correlated substantially with arthroscopic Lage classification (kappa coefficient = 0.65). CTA and arthroscopic findings showed similar distribution patterns of the tears with most lesions located in antero- and postero-superior areas (p = 0.013). Direct CT arthrography using MDCT may be a useful diagnostic technique in the detection of acetabular labral tear. (orig.)

  3. Visual vs Fully Automatic Histogram-Based Assessment of Idiopathic Pulmonary Fibrosis (IPF) Progression Using Sequential Multidetector Computed Tomography (MDCT)

    Science.gov (United States)

    Colombi, Davide; Dinkel, Julien; Weinheimer, Oliver; Obermayer, Berenike; Buzan, Teodora; Nabers, Diana; Bauer, Claudia; Oltmanns, Ute; Palmowski, Karin; Herth, Felix; Kauczor, Hans Ulrich; Sverzellati, Nicola

    2015-01-01

    Objectives To describe changes over time in extent of idiopathic pulmonary fibrosis (IPF) at multidetector computed tomography (MDCT) assessed by semi-quantitative visual scores (VSs) and fully automatic histogram-based quantitative evaluation and to test the relationship between these two methods of quantification. Methods Forty IPF patients (median age: 70 y, interquartile: 62-75 years; M:F, 33:7) that underwent 2 MDCT at different time points with a median interval of 13 months (interquartile: 10-17 months) were retrospectively evaluated. In-house software YACTA quantified automatically lung density histogram (10th-90th percentile in 5th percentile steps). Longitudinal changes in VSs and in the percentiles of attenuation histogram were obtained in 20 untreated patients and 20 patients treated with pirfenidone. Pearson correlation analysis was used to test the relationship between VSs and selected percentiles. Results In follow-up MDCT, visual overall extent of parenchymal abnormalities (OE) increased in median by 5 %/year (interquartile: 0 %/y; +11 %/y). Substantial difference was found between treated and untreated patients in HU changes of the 40th and of the 80th percentiles of density histogram. Correlation analysis between VSs and selected percentiles showed higher correlation between the changes (Δ) in OE and Δ 40th percentile (r=0.69; phistogram analysis at one year follow-up of IPF patients, whether treated or untreated: Δ 40th percentile might reflect the change in overall extent of lung abnormalities, notably of ground-glass pattern; furthermore Δ 80th percentile might reveal the course of reticular opacities. PMID:26110421

  4. SPIO-Enhanced MRI Findings of Well-Differentiated Hepatocellular Carcinomas: Correlation with MDCT Findings

    International Nuclear Information System (INIS)

    Kim, Seong Hyun; Lee, Won Jae; Lim, Hyo K.; Park, Cheol Keun

    2009-01-01

    This study was designed to assess superparamagnetic iron oxide (SPIO)-enhanced MRI findings of well-differentiated hepatocellular carcinomas (HCCs) correlated with their multidetector-row CT (MDCT) findings. Seventy-two patients with 84 pathologically proven well-differentiated HCCs underwent triple-phase MDCT and SPIO-enhanced MRI at a magnetic field strength of 1.5 Tesla (n = 49) and 3.0 Tesla (n = 23). Two radiologists in consensus retrospectively reviewed the CT and MR images for attenuation value and the signal intensity of each tumor. The proportion of hyperintense HCCs as depicted on SPIO-enhanced T2- or T2*-weighted images were compared in terms of tumor size ( 1 cm), five CT attenuation patterns based on arterial and equilibrium phases and magnetic field strength, by the use of univariate and multivariate analyses. Seventy-eight (93%) and 71 (85%) HCCs were identified by CT and on SPIO-enhanced T2- and T2*-weighted images, respectively. For the CT attenuation pattern, one (14%) of seven isodense-isodense, four (67%) of six hypodense- hypodense, four (80%) of five isodense-hypodense, 14 (88%) of 16 hyperdense- isodense and 48 (96%) of 50 hyperdense-hypodense HCCs were hyperintense (Cochran-Armitage test for trend, p 0.05). Most well-differentiated HCCs show hyperintensity on SPIOenhanced MRI, although the lesions show various CT attenuation patterns. The CT attenuation pattern is the main factor that affects the proportion of hyperintense well-differentiated HCCs as depicted on SPIO-enhanced MRI

  5. MDCT linear and volumetric analysis of adrenal glands: Normative data and multiparametric assessment

    International Nuclear Information System (INIS)

    Carsin-Vu, Aline; Mule, Sebastien; Janvier, Annaelle; Hoeffel, Christine; Oubaya, Nadia; Delemer, Brigitte; Soyer, Philippe

    2016-01-01

    To study linear and volumetric adrenal measurements, their reproducibility, and correlations between total adrenal volume (TAV) and adrenal micronodularity, age, gender, body mass index (BMI), visceral (VAAT) and subcutaneous adipose tissue volume (SAAT), presence of diabetes, chronic alcoholic abuse and chronic inflammatory disease (CID). We included 154 patients (M/F, 65/89; mean age, 57 years) undergoing abdominal multidetector row computed tomography (MDCT). Two radiologists prospectively independently performed adrenal linear and volumetric measurements with semi-automatic software. Inter-observer reliability was studied using inter-observer correlation coefficient (ICC). Relationships between TAV and associated factors were studied using bivariate and multivariable analysis. Mean TAV was 8.4 ± 2.7 cm 3 (3.3-18.7 cm 3 ). ICC was excellent for TAV (0.97; 95 % CI: 0.96-0.98) and moderate to good for linear measurements. TAV was significantly greater in men (p < 0.0001), alcoholics (p = 0.04), diabetics (p = 0.0003) and those with micronodular glands (p = 0.001). TAV was lower in CID patients (p = 0.0001). TAV correlated positively with VAAT (r = 0.53, p < 0.0001), BMI (r = 0.42, p < 0.0001), SAAT (r = 0.29, p = 0.0003) and age (r = 0.23, p = 0.005). Multivariable analysis revealed gender, micronodularity, diabetes, age and BMI as independent factors influencing TAV. Adrenal gland MDCT-based volumetric measurements are more reproducible than linear measurements. Gender, micronodularity, age, BMI and diabetes independently influence TAV. (orig.)

  6. Quality of life and time to death: have the health gains of preventive interventions been underestimated?

    Science.gov (United States)

    Gheorghe, Maria; Brouwer, Werner B F; van Baal, Pieter H M

    2015-04-01

    This article explores the implications of the relation between quality of life (QoL) and time to death (TTD) for economic evaluations of preventive interventions. By using health survey data on QoL for the general Dutch population linked to the mortality registry, we quantify the magnitude of this relationship. For addressing specific features of the nonstandard QoL distribution such as boundness, skewness, and heteroscedasticity, we modeled QoL using a generalized additive model for location, scale, and shape (GAMLSS) with a β inflated outcome distribution. Our empirical results indicate that QoL decreases when approaching death, suggesting that there is a strong relationship between TTD and QoL. Predictions of different regression models revealed that ignoring this relationship results in an underestimation of the quality-adjusted life year (QALY) gains for preventive interventions. The underestimation ranged between 3% and 7% and depended on age, the number of years gained from the intervention, and the discount rate used. © The Author(s) 2014.

  7. Depiction of normal gastrointestinal anatomy with MDCT: comparison of low- and high-attenuation oral contrast media.

    Science.gov (United States)

    Erturk, Sukru Mehmet; Mortelé, Koenraad J; Oliva, Maria-Raquel; Ichikawa, Tomoaki; Silverman, Stuart G; Cantisani, Vito; Pagliara, Elisa; Ros, Pablo R

    2008-04-01

    To compare low- and high-attenuation oral contrast media for depiction of normal gastrointestinal anatomy with multidetector-row computed tomography (MDCT). A prospective, randomized study of 90 consecutive patients without known or suspected gastrointestinal disease was conducted after the approval of our Institutional Review Board. All patients underwent IV contrast-enhanced abdominal and pelvic CT scans after oral administration of 900 ml of either low- or high-attenuation barium sulphate suspension. Using a five-point scale, two radiologists independently graded distention and wall visualization of stomach, duodenum, jejunum, and ileum. The degree of distention and wall visualization was compared using Mann-Whitney U-test. Duodenal, jejunal and ileal distention (pcontrast medium were significantly higher than those with high-attenuation barium sulphate preparation, for reader 1. Duodenal and jejunal wall visualization scores with low-attenuation contrast medium (pcontrast medium, for reader 2. Interobserver agreement was fair to good for both distention (kappa-range: 0.41-0.74) and wall visualization (kappa-range: 0.48-0.71). MDCT with low-attenuation contrast medium provides distention and wall visualization of the GI tract that is equal or better than high-attenuation contrast medium.

  8. The diagnostic value of multiplanar reconstruction on MDCT colonography for the preoperative staging of colorectal cancer

    International Nuclear Information System (INIS)

    Jin, Kwang Nam; Kim, Se Hyung; Lee, Jae Young; Lee, Jeong Min; Han, Joon Koo; Choi, Byung Ihn; Shin, Kyung-Sook

    2006-01-01

    The purpose of this study was to determine whether multiplanar reconstruction (MPR) images can improve the accuracy of MDCT-based colorectal cancer preoperative staging by receiver-operating characteristic (ROC) analysis. Fifty-five patients with colorectal cancer underwent contrast-enhanced CT colonography using an 8- or 16-row scanner. Two separate interval reviews of the axial MDCT datasets with/without MPR images (coronal and sagittal) were performed independently by two radiologists blinded to both the colonoscopic and histopathologic results. At each review session, the radiologists were asked to determine the colorectal cancer TNM stage within the context of differentiating ≤T3 from T4, N0 from ≥N1 and M0 from M1 using a five-point confidence scale. The radiologists' performance for staging the colorectal cancer using axial CT datasets with/without MPR images was evaluated using ROC analysis. Sensitivities, specificities and interobserver agreement were assessed. When MPR images were added, significant improvement was achieved by both radiologists for differentiating N0 from ≥N1 in terms of both A Z (0.651 to 0.769; 0.573 to 0.713) and specificity (26.7 to 69.2%; 23.1 to 76.9%) (P 0.05), but a significant improvement in the specificity (70 to 90%; 80 to 92%) was achieved by one radiologist (P<0.05). In terms of the M staging, a significant improvement in the Az (0.844 to 0.996) was observed for the combined interpretation of the axial and MPR images by one radiologist (P<0.05). Furthermore, substantial or almost perfect interobserver agreement was achieved for all TNM stagings for the combined interpretations (κ=0.641-0.866), whereas only fair to substantial agreement was achieved for the axial images alone (κ=0.337-0.707). In conclusion, the combined interpretation of the axial and MPR MDCT images significantly improved the local staging of colorectal cancer compared with assessments based on axial images alone. (orig.)

  9. Lung MRI of invasive fungal infection at 3 Tesla: evaluation of five different pulse sequences and comparison with multidetector computed tomography (MDCT)

    Energy Technology Data Exchange (ETDEWEB)

    Yan, Chenggong; Tan, Xiangliang; Li, Caixia; Wu, Yuankui; Hao, Peng; Xiong, Wei; Xu, Yikai [Southern Medical University, Department of Medical Imaging Center, Nanfang Hospital, Guangzhou, Guangdong (China); Wei, Qi; Feng, Ru; Xu, Jun [Southern Medical University, Department of Hematology, Nanfang Hospital, Guangzhou (China); Chan, Queenie [Philips Healthcare, New Territories (China)

    2014-09-18

    To evaluate the diagnostic performance of five MR sequences to detect pulmonary infectious lesions in patients with invasive fungal infection (IFI), using multidetector computed tomography (MDCT) as the reference standard. Thirty-four immunocompromised patients with suspected IFI underwent MDCT and MRI. The MR studies were performed using five pulse sequences at 3.0 T: T2-weighted turbo spin echo (TSE), short-tau inversion recovery (STIR), spectrally selective attenuated inversion recovery (SPAIR), T1-weighted high resolution isotropic volume excitation (e-THRIVE) and T1-weighted fast field echo (T1-FFE). The size, lesion-to-lung contrast ratio and the detectability of pulmonary lesions on MR images were assessed. Image quality and artefacts on different sequences were also rated. A total of 84 lesions including nodules (n = 44) and consolidation (n = 40) were present in 75 lobes. SPAIR and e-THRIVE images achieved high overall lesion-related sensitivities for the detection of pulmonary abnormalities (90.5 % and 86.9 %, respectively). STIR showed the highest lesion-to-lung contrast ratio for nodules (21.8) and consolidation (17.0), whereas TSE had the fewest physiological artefacts. MRI at 3.0 T can depict clinically significant pulmonary IFI abnormalities with high accuracy compared to MDCT. SPAIR and e-THRIVE are preferred sequences for the detection of infectious lesions of 5 mm and larger. (orig.)

  10. Contrast enhanced chest-MDCT in oncologic patients. Prospective evaluation of the prevalence of incidental pulmonary embolism and added value of thin reconstructions

    Energy Technology Data Exchange (ETDEWEB)

    Tresoldi, Silvia; Flor, Nicola [Azienda Ospedaliera San Paolo, Dipartimento di Radiologia Diagnostica ed Interventistica, Milano (Italy); Luciani, Andrea [Azienda Ospedaliera San Paolo, Oncologia, Dipartimento di Medicina, Milano (Italy); Lombardi, Maria Antonietta; Colombo, Bernardo [Universita degli Studi di Milano, Scuola di Specializzazione in Radiodiagnostica, Facolta di Medicina e Chirurgia, Milano (Italy); Cornalba, Gianpaolo [Azienda Ospedaliera San Paolo, Dipartimento di Radiologia Diagnostica ed Interventistica, Milano (Italy); Universita degli Studi di Milano, Dipartimento di Scienze della Salute, Milano (Italy)

    2015-11-15

    To prospectively assess prevalence/characteristics of clinically unsuspected pulmonary embolism (PE) in cancer patients undergoing follow-up chest MDCT and investigate MDCT protocol. We evaluated 1013 oncologic patients. MDCT images at 5 and 1.25 mm thickness were independently evaluated. Pulmonary artery opacification degree was assessed. Presence, level, and site of PE were reported. Type of malignancy and metastases were reported for PE-positive patients. After excluding 1.4 % (14/1013) of examinations due to inadequate vessel opacification, 999 patients (572 male; mean age:68 ± 12 years; range:26-93 years) entered the study. Prevalence of PE was 5 %. There was significant improvement in the sensitivity for both readers in the evaluation of 1.25 mm compared to 5 mm images (46-50 % to 82-92 %). 30 % (15/51) PE were not described by the radiologist in the prospectively issued report; 53 % (27/51) of PE were segmental, 72.5 % (37/51) unilateral. The right lower lobe was the most involved (59 %). 27 % patients had colon cancer, 18 % lung cancer. Among PE-positive patients (25 male; mean age 70 ± 10 years; range:44-87 years), 25 % (13/51) had lung cancer, 15 % (8/51) colon cancer. Thin reconstructions are essential for PE diagnosis, regardless of reader experience. Regarding oncologic patients, incidental PE diagnosis influences anticoagulation therapy. (orig.)

  11. Contrast enhanced chest-MDCT in oncologic patients. Prospective evaluation of the prevalence of incidental pulmonary embolism and added value of thin reconstructions

    International Nuclear Information System (INIS)

    Tresoldi, Silvia; Flor, Nicola; Luciani, Andrea; Lombardi, Maria Antonietta; Colombo, Bernardo; Cornalba, Gianpaolo

    2015-01-01

    To prospectively assess prevalence/characteristics of clinically unsuspected pulmonary embolism (PE) in cancer patients undergoing follow-up chest MDCT and investigate MDCT protocol. We evaluated 1013 oncologic patients. MDCT images at 5 and 1.25 mm thickness were independently evaluated. Pulmonary artery opacification degree was assessed. Presence, level, and site of PE were reported. Type of malignancy and metastases were reported for PE-positive patients. After excluding 1.4 % (14/1013) of examinations due to inadequate vessel opacification, 999 patients (572 male; mean age:68 ± 12 years; range:26-93 years) entered the study. Prevalence of PE was 5 %. There was significant improvement in the sensitivity for both readers in the evaluation of 1.25 mm compared to 5 mm images (46-50 % to 82-92 %). 30 % (15/51) PE were not described by the radiologist in the prospectively issued report; 53 % (27/51) of PE were segmental, 72.5 % (37/51) unilateral. The right lower lobe was the most involved (59 %). 27 % patients had colon cancer, 18 % lung cancer. Among PE-positive patients (25 male; mean age 70 ± 10 years; range:44-87 years), 25 % (13/51) had lung cancer, 15 % (8/51) colon cancer. Thin reconstructions are essential for PE diagnosis, regardless of reader experience. Regarding oncologic patients, incidental PE diagnosis influences anticoagulation therapy. (orig.)

  12. Non-differential underestimation may cause a threshold effect of exposure to appear as a dose-response relationship

    NARCIS (Netherlands)

    Verkerk, P. H.; Buitendijk, S. E.

    1992-01-01

    It is generally believed that non-differential misclassification will lead to a bias toward the null-value. However, using one graphical and one numerical example, we show that in situations where underestimation more than overestimation is the problem, non-differential misclassification may lead to

  13. Some sources of the underestimation of evaluated cross section uncertainties

    International Nuclear Information System (INIS)

    Badikov, S.A.; Gai, E.V.

    2003-01-01

    The problem of the underestimation of evaluated cross-section uncertainties is addressed. Two basic sources of the underestimation of evaluated cross-section uncertainties - a) inconsistency between declared and observable experimental uncertainties and b) inadequacy between applied statistical models and processed experimental data - are considered. Both the sources of the underestimation are mainly a consequence of existence of the uncertainties unrecognized by experimenters. A model of a 'constant shift' is proposed for taking unrecognised experimental uncertainties into account. The model is applied for statistical analysis of the 238 U(n,f)/ 235 U(n,f) reaction cross-section ratio measurements. It is demonstrated that multiplication by sqrt(χ 2 ) as instrument for correction of underestimated evaluated cross-section uncertainties fails in case of correlated measurements. It is shown that arbitrary assignment of uncertainties and correlation in a simple least squares fit of two correlated measurements of unknown mean leads to physically incorrect evaluated results. (author)

  14. Pancreatic neuroendocrine tumour (PNET): Staging accuracy of MDCT and its diagnostic performance for the differentiation of PNET with uncommon CT findings from pancreatic adenocarcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jung Hoon; Lee, Jeong Min; Han, Joon Koo; Choi, Byung-Ihn [Seoul National University Hospital, Department of Radiology, 101 Daehangno, Jongno-gu, Seoul (Korea, Republic of); Seoul National University College of Medicine, Institute of Radiation Medicine, Seoul (Korea, Republic of); Eun, Hyo Won [Yonsei University College of Medicine, Department of Radiology, Severance Hospital, Seodaemun-ku, Seoul (Korea, Republic of); Kim, Young Jae [Soonchunhyang University Hospital, Department of Radiology, 657 Hannam-Dong, Youngsan-Ku, Seoul (Korea, Republic of)

    2016-05-15

    To investigate staging accuracy of multidetector CT (MDCT) for pancreatic neuroendocrine tumour (PNET) and diagnostic performance for differentiation of PNET from pancreatic adenocarcinoma. We included 109 patients with surgically proven PNET (NETG1 = 66, NETG2 = 31, NEC = 12) who underwent MDCT. Two reviewers assessed stage and presence of predefined CT findings. We analysed the relationship between CT findings and tumour grade. Using PNETs with uncommon findings, we also estimated the possibility of PNET or adenocarcinoma. Accuracy for T stage was 85-88 % and N-metastasis was 83-89 %. Common findings included well circumscribed, homogeneously enhanced, hypervascular mass, common in lower grade tumours (p < 0.05). Uncommon findings included ill-defined, heterogeneously enhanced, hypovascular mass and duct dilation, common in higher grade tumours (p < 0.05). Using 31 PNETs with uncommon findings, diagnostic performance for differentiation from adenocarcinoma was 0.760-0.806. Duct dilatation was an independent predictor for adenocarcinoma (Exp(B) = 4.569). PNETs with uncommon findings were associated with significantly worse survival versus PNET with common findings (62.7 vs. 95.7 months, p < 0.001). MDCT is useful for preoperative evaluation of PNET; it not only accurately depicts the tumour stage but also prediction of tumour grade, because uncommon findings were more common in higher grade tumours. (orig.)

  15. Hi-Res scan mode in clinical MDCT systems: Experimental assessment of spatial resolution performance.

    Science.gov (United States)

    Cruz-Bastida, Juan P; Gomez-Cardona, Daniel; Li, Ke; Sun, Heyi; Hsieh, Jiang; Szczykutowicz, Timothy P; Chen, Guang-Hong

    2016-05-01

    The introduction of a High-Resolution (Hi-Res) scan mode and another associated option that combines Hi-Res mode with the so-called High Definition (HD) reconstruction kernels (referred to as a Hi-Res/HD mode in this paper) in some multi-detector CT (MDCT) systems offers new opportunities to increase spatial resolution for some clinical applications that demand high spatial resolution. The purpose of this work was to quantify the in-plane spatial resolution along both the radial direction and tangential direction for the Hi-Res and Hi-Res/HD scan modes at different off-center positions. A technique was introduced and validated to address the signal saturation problem encountered in the attempt to quantify spatial resolution for the Hi-Res and Hi-Res/HD scan modes. Using the proposed method, the modulation transfer functions (MTFs) of a 64-slice MDCT system (Discovery CT750 HD, GE Healthcare) equipped with both Hi-Res and Hi-Res/HD modes were measured using a metal bead at nine different off-centered positions (0-16 cm with a step size of 2 cm); at each position, both conventional scans and Hi-Res scans were performed. For each type of scan and position, 80 repeated acquisitions were performed to reduce noise induced uncertainties in the MTF measurements. A total of 15 reconstruction kernels, including eight conventional kernels and seven HD kernels, were used to reconstruct CT images of the bead. An ex vivo animal study consisting of a bone fracture model was performed to corroborate the MTF results, as the detection of this high-contrast and high frequency task is predominantly determined by spatial resolution. Images of this animal model generated by different scan modes and reconstruction kernels were qualitatively compared with the MTF results. At the centered position, the use of Hi-Res mode resulted in a slight improvement in the MTF; each HD kernel generated higher spatial resolution than its counterpart conventional kernel. However, the MTF along the

  16. Body Size Estimation from Early to Middle Childhood: Stability of Underestimation, BMI, and Gender Effects

    Directory of Open Access Journals (Sweden)

    Silje Steinsbekk

    2017-11-01

    Full Text Available Individuals who are overweight are more likely to underestimate their body size than those who are normal weight, and overweight underestimators are less likely to engage in weight loss efforts. Underestimation of body size might represent a barrier to prevention and treatment of overweight; thus insight in how underestimation of body size develops and tracks through the childhood years is needed. The aim of the present study was therefore to examine stability in children’s underestimation of body size, exploring predictors of underestimation over time. The prospective path from underestimation to BMI was also tested. In a Norwegian cohort of 6 year olds, followed up at ages 8 and 10 (analysis sample: n = 793 body size estimation was captured by the Children’s Body Image Scale, height and weight were measured and BMI calculated. Overall, children were more likely to underestimate than overestimate their body size. Individual stability in underestimation was modest, but significant. Higher BMI predicted future underestimation, even when previous underestimation was adjusted for, but there was no evidence for the opposite direction of influence. Boys were more likely than girls to underestimate their body size at ages 8 and 10 (age 8: 38.0% vs. 24.1%; Age 10: 57.9% vs. 30.8% and showed a steeper increase in underestimation with age compared to girls. In conclusion, the majority of 6, 8, and 10-year olds correctly estimate their body size (prevalence ranging from 40 to 70% depending on age and gender, although a substantial portion perceived themselves to be thinner than they actually were. Higher BMI forecasted future underestimation, but underestimation did not increase the risk for excessive weight gain in middle childhood.

  17. Facilitating coronary artery evaluation in MDCT using a 3D automatic vessel segmentation tool

    International Nuclear Information System (INIS)

    Fawad Khan, M.; Gurung, Jessen; Maataoui, Adel; Brehmer, Boris; Herzog, Christopher; Vogl, Thomas J.; Wesarg, Stefan; Dogan, Selami; Ackermann, Hanns; Assmus, Birgit

    2006-01-01

    The purpose of this study was to investigate a 3D coronary artery segmentation algorithm using 16-row MDCT data sets. Fifty patients underwent cardiac CT (Sensation 16, Siemens) and coronary angiography. Automatic and manual detection of coronary artery stenosis was performed. A 3D coronary artery segmentation algorithm (Fraunhofer Institute for Computer Graphics, Darmstadt) was used for automatic evaluation. All significant stenoses (>50%) in vessels >1.5 mm in diameter were protocoled. Each detection tool was used by one reader who was blinded to the results of the other detection method and the results of coronary angiography. Sensitivity and specificity were determined for automatic and manual detection as well as was the time for both CT-based evaluation methods. The overall sensitivity and specificity of the automatic and manual approach were 93.1 vs. 95.83% and 86.1 vs. 81.9%. The time required for automatic evaluation was significantly shorter than with the manual approach, i.e., 246.04±43.17 s for the automatic approach and 526.88±45.71 s for the manual approach (P<0.0001). In 94% of the coronary artery branches, automatic detection required less time than the manual approach. Automatic coronary vessel evaluation is feasible. It reduces the time required for cardiac CT evaluation with similar sensitivity and specificity as well as facilitates the evaluation of MDCT coronary angiography in a standardized fashion. (orig.)

  18. The diagnosis of old gravel aspiration in adults by MDCT: a case report

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Mi Young; Lee, Ki Yeol; Seo, Bo Kyoung; Kim, Je Hyeong; Jung, Ki Hwan [Ansan Hospital, Korea University Medical Center, Ansan (Korea, Republic of)

    2008-03-15

    We report a case of old gravel aspiration in a 57-year-old man who had been accidentally buried in a field of construction for ten hours, three years prior. A chest radiograph showed peribronchial pneumonic infiltrates in the right lower lobe, with a proximal ovoid radiopaque endobronchial density at the trunchus basalis. These findings were more clearly visualized on the 64-channel multidetector CT (MDCT). Moreover, the patient recovered from his condition, following a bronchoscopic retrieval. However, the patient had persistent bronchiectasis of the right lower lobe on a subsequent follow-up chest radiograph, one month later.

  19. Central venous device-related thrombosis as imaged with MDCT in oncologic patients: prevalence and findings

    International Nuclear Information System (INIS)

    Catalano, Orlando; Castelguidone, Elisabetta de Lutio di; Granata, Vincenza; D'Errico, Adolfo Gallipoli; Sandomenico, Claudia; Petrillo, Mario; Aprea, Pasquale

    2011-01-01

    Background: Venous thrombosis is a common occurrence in cancer patients, developing spontaneously or in combination with indwelling central venous devices (CVD). Purpose: To analyze the multidetector CT (MDCT) prevalence, appearance, and significance of catheter related thoracic venous thrombosis in oncologic patients and to determine the percentage of thrombi identified in the original reports. Material and Methods: Five hundred consecutive patients were considered. Inclusion criteria were: presence of a CVD; availability of a contrast-enhanced MDCT; and cancer history. Exclusion criteria were: direct tumor compression/infiltration of the veins; poor image quality; device tip not in the scanned volume; and missing clinical data. Seventeen (3.5%) out of the final 481 patients had a diagnosis of venous thrombosis. Results: Factors showing the highest correlation with thrombosis included peripherally-inserted CVD, right brachiocephalic vein tip location, patient performance status 3, metastatic stage disease, ongoing chemotherapy, and longstanding CVD. The highest prevalence was in patients with lymphoma, lung carcinoma, melanoma, and gynecologic malignancies. Eleven out of 17 cases had not been identified in the original report. Conclusion: CVD-related thrombosis is not uncommon in cancer patients and can also be observed in outpatients with a good performance status and a non-metastatic disease. Thrombi can be very tiny. Radiologists should be aware of the possibility to identify (or overlook) small thrombi

  20. The Perception of Time Is Underestimated in Adolescents With Anorexia Nervosa.

    Science.gov (United States)

    Vicario, Carmelo M; Felmingham, Kim

    2018-01-01

    Research has revealed reduced temporal discounting (i.e., increased capacity to delay reward) and altered interoceptive awareness in anorexia nervosa (AN). In line with the research linking temporal underestimation with a reduced tendency to devalue a reward and reduced interoceptive awareness, we tested the hypothesis that time duration might be underestimated in AN. Our findings revealed that patients with AN displayed lower timing accuracy in the form of timing underestimation compared with controls. These results were not predicted by clinical, demographic factors, attention, and working memory performance of the participants. The evidence of a temporal underestimation bias in AN might be clinically relevant to explain their abnormal motivation in pursuing a long-term restrictive diet, in line with the evidence that increasing the subjective temporal proximity of remote future goals can boost motivation and the actual behavior to reach them.

  1. The Perception of Time Is Underestimated in Adolescents With Anorexia Nervosa

    Directory of Open Access Journals (Sweden)

    Carmelo M. Vicario

    2018-04-01

    Full Text Available Research has revealed reduced temporal discounting (i.e., increased capacity to delay reward and altered interoceptive awareness in anorexia nervosa (AN. In line with the research linking temporal underestimation with a reduced tendency to devalue a reward and reduced interoceptive awareness, we tested the hypothesis that time duration might be underestimated in AN. Our findings revealed that patients with AN displayed lower timing accuracy in the form of timing underestimation compared with controls. These results were not predicted by clinical, demographic factors, attention, and working memory performance of the participants. The evidence of a temporal underestimation bias in AN might be clinically relevant to explain their abnormal motivation in pursuing a long-term restrictive diet, in line with the evidence that increasing the subjective temporal proximity of remote future goals can boost motivation and the actual behavior to reach them.

  2. Osteoporosis imaging: effects of bone preservation on MDCT-based trabecular bone microstructure parameters and finite element models

    International Nuclear Information System (INIS)

    Baum, Thomas; Grande Garcia, Eduardo; Burgkart, Rainer; Gordijenko, Olga; Liebl, Hans; Jungmann, Pia M.; Gruber, Michael; Zahel, Tina; Rummeny, Ernst J.; Waldt, Simone; Bauer, Jan S.

    2015-01-01

    Osteoporosis is defined as a skeletal disorder characterized by compromised bone strength due to a reduction of bone mass and deterioration of bone microstructure predisposing an individual to an increased risk of fracture. Trabecular bone microstructure analysis and finite element models (FEM) have shown to improve the prediction of bone strength beyond bone mineral density (BMD) measurements. These computational methods have been developed and validated in specimens preserved in formalin solution or by freezing. However, little is known about the effects of preservation on trabecular bone microstructure and FEM. The purpose of this observational study was to investigate the effects of preservation on trabecular bone microstructure and FEM in human vertebrae. Four thoracic vertebrae were harvested from each of three fresh human cadavers (n = 12). Multi-detector computed tomography (MDCT) images were obtained at baseline, 3 and 6 month follow-up. In the intervals between MDCT imaging, two vertebrae from each donor were formalin-fixed and frozen, respectively. BMD, trabecular bone microstructure parameters (histomorphometry and fractal dimension), and FEM-based apparent compressive modulus (ACM) were determined in the MDCT images and validated by mechanical testing to failure of the vertebrae after 6 months. Changes of BMD, trabecular bone microstructure parameters, and FEM-based ACM in formalin-fixed and frozen vertebrae over 6 months ranged between 1.0–5.6 % and 1.3–6.1 %, respectively, and were not statistically significant (p > 0.05). BMD, trabecular bone microstructure parameters, and FEM-based ACM as assessed at baseline, 3 and 6 month follow-up correlated significantly with mechanically determined failure load (r = 0.89–0.99; p < 0.05). The correlation coefficients r were not significantly different for the two preservation methods (p > 0.05). Formalin fixation and freezing up to six months showed no significant effects on trabecular bone microstructure

  3. Influence of detector collimation on SNR in four different MDCT scanners using a reconstructed slice thickness of 5 mm

    International Nuclear Information System (INIS)

    Verdun, F.R.; Pachoud, M.; Monnin, P.; Valley, J.-F.; Noel, A.; Meuli, R.; Schnyder, P.; Denys, A.

    2004-01-01

    The purpose of this paper is to compare the influence of detector collimation on the signal-to-noise ratio (SNR) for a 5.0 mm reconstructed slice thickness for four multi-detector row CT (MDCT) units. SNRs were measured on Catphan test phantom images from four MDCT units: a GE LightSpeed QX/I, a Marconi MX 8000, a Toshiba Aquilion and a Siemens Volume Zoom. Five-millimetre-thick reconstructed slices were obtained from acquisitions performed using detector collimations of 2.0-2.5 mm and 5.0 mm, 120 kV, a 360 tube rotation time of 0.5 s, a wide range of mA and pitch values in the range of 0.75-0.85 and 1.25-1.5. For each set of acquisition parameters, a Wiener spectrum was also calculated. Statistical differences in SNR for the different acquisition parameters were evaluated using a Student's t-test (P<0.05). The influence of detector collimation on the SNR for a 5.0-mm reconstructed slice thickness is different for different MDCT scanners. At pitch values lower than unity, the use of a small detector collimation to produce 5.0-mm thick slices is beneficial for one unit and detrimental for another. At pitch values higher than unity, using a small detector collimation is beneficial for two units. One manufacturer uses different reconstruction filters when switching from a 2.5- to a 5.0-mm detector collimation. For a comparable reconstructed slice thickness, using a smaller detector collimation does not always reduce image noise. Thus, the impact of the detector collimation on image noise should be determined by standard deviation calculations, and also by assessing the power spectra of the noise. (orig.)

  4. Risk of contrast-medium-induced nephropathy in high-risk patients undergoing MDCT - A pooled analysis of two randomized trials

    Energy Technology Data Exchange (ETDEWEB)

    Thomsen, Henrik S. [University of Copenhagen, Department of Diagnostic Radiology, Copenhagen University Hospital Herlev, and Department of Diagnostic Sciences, Faculty of Health Sciences, Herlev (Denmark); Morcos, Sameh K. [University of Sheffield, Department of Diagnostic Imaging, Northern General Hospital, Sheffield (United Kingdom)

    2009-04-15

    The incidence of contrast-medium-induced nephropathy (CIN) following intravenous (IV) CM administration of contrast media to renally impaired patients undergoing multidetector computed tomography (MDCT) is not well characterized. Our objective was to investigate the incidence of CIN in patients with glomerular filtration rate (GFR) <60 ml/min undergoing contrast-enhanced MDCT examinations and to compare the rates of CIN following the IV administration of low-osmolar contrast media (LOCM, iopamidol and iomeprol) and an iso-osmolar contrast medium (IOCM, iodixanol). A total of 301 adult patients with moderate-to-severe renal failure received a similar IV contrast dose (40 gI). Serum creatinine (SCr) was measured at screening, baseline and 48-72 {+-} 6 h after the MDCT examination. Primary CIN outcome was an increase in SCr {>=}0.5 mg/dl ({>=}44.2 {mu}mol/l) from baseline. The CIN rates were 2.3% in the total population, 0.6% when GFR >40 ml/min, 4.6% when GFR <40 ml/min and 7.8% in patients with GFR <30 ml/min. The incidence of CIN was significantly higher after iodixanol than after LOCM (seven patients, 4.7% following IOCM, no CIN cases following the LOCM; p = 0.007). Significant differences in favor of the LOCM were also observed in patients with GFR <40 ml/min and GFR <30 ml/min. Following the IV administration of nonionic contrast agents in patients with moderate-to-severe renal insufficiency, the risk of significant CIN seems to be low. The IOCM iodixanol caused a higher rate of CIN than the LOCM iopamidol and iomeprol, especially in high-risk patients. Differences in osmolality between these LOCM and iodixanol do not play a role in the genesis of CIN. (orig.)

  5. Validity of linear measurements of the jaws using ultralow-dose MDCT and the iterative techniques of ASIR and MBIR.

    Science.gov (United States)

    Al-Ekrish, Asma'a A; Al-Shawaf, Reema; Schullian, Peter; Al-Sadhan, Ra'ed; Hörmann, Romed; Widmann, Gerlig

    2016-10-01

    To assess the comparability of linear measurements of dental implant sites recorded from multidetector computed tomography (MDCT) images obtained using standard-dose filtered backprojection (FBP) technique with those from various ultralow doses combined with FBP, adaptive statistical iterative reconstruction (ASIR), and model-based iterative reconstruction (MBIR) techniques. The results of the study may contribute to MDCT dose optimization for dental implant site imaging. MDCT scans of two cadavers were acquired using a standard reference protocol and four ultralow-dose test protocols (TP). The volume CT dose index of the different dose protocols ranged from a maximum of 30.48-36.71 mGy to a minimum of 0.44-0.53 mGy. All scans were reconstructed using FBP, ASIR-50, ASIR-100, and MBIR, and either a bone or standard reconstruction kernel. Linear measurements were recorded from standardized images of the jaws by two examiners. Intra- and inter-examiner reliability of the measurements were analyzed using Cronbach's alpha and inter-item correlation. Agreement between the measurements obtained with the reference-dose/FBP protocol and each of the test protocols was determined with Bland-Altman plots and linear regression. Statistical significance was set at a P-value of 0.05. No systematic variation was found between the linear measurements obtained with the reference protocol and the other imaging protocols. The only exceptions were TP3/ASIR-50 (bone kernel) and TP4/ASIR-100 (bone and standard kernels). The mean measurement differences between these three protocols and the reference protocol were within ±0.1 mm, with the 95 % confidence interval limits being within the range of ±1.15 mm. A nearly 97.5 % reduction in dose did not significantly affect the height and width measurements of edentulous jaws regardless of the reconstruction algorithm used.

  6. Abdominal vascular and visceral parenchymal contrast enhancement in MDCT: Effects of injection duration

    Energy Technology Data Exchange (ETDEWEB)

    Tsuge, Yusuke, E-mail: tsugeu@cup.ocn.ne.jp [Department of Radiology, Kizawa Memorial Hospital, 590 Kobityo Shimokobi, Minokamo City, Gifu 505-8503 (Japan); Kanematsu, Masayuki [Department of Radiology, Gifu University Hospital, Gifu (Japan); Department of Radiology Services, Gifu University Hospital, Gifu (Japan); Goshima, Satoshi; Kondo, Hiroshi [Department of Radiology, Gifu University Hospital, Gifu (Japan); Yokoyama, Ryujiro; Miyoshi, Toshiharu [Department of Radiology Services, Gifu University Hospital, Gifu (Japan); Onozuka, Minoru [Department of Physiology and Neuroscience, Kanagawa Dental College, Yokosuka (Japan); Moriyama, Noriyuki [Research Center for Cancer Prevention and Screening, National Cancer Center Hospital, Tsukiji (Japan); Bae, Kyongtae T. [Radiology and Biomedical Engineering, University of Pittsburgh, Pittsburgh, PA (United States)

    2011-11-15

    Purpose: To evaluate and compare the effect of short and long injection durations on aortic, pancreatic and hepatic enhancement in abdominal MDCT. Methods and materials: Triphasic contrast-enhanced CT images (16-MDCT, 1.25-mm collimation, 5-mm thickness, 6.1-s acquisition time for each phase) were obtained with 2 mL/kg injection of 300 mgI/mL iodine contrast material in 116 patients. Patients were prospectively randomized into two groups: one receiving contrast medium for 25-s injection duration and the other for 35-s injection duration. In both groups, triphasic scans were initiated 5, 15, and 40 s after the completion of contrast injection for the first, second and third phases, respectively. CT values (HU) in the abdominal aorta, liver, spleen, pancreas, splenic and superior mesenteric arteries, and veins (splenic, superior mesenteric, portal, and hepatic) were measured. Quantitative and qualitative analysis for the degree of contrast enhancement between the two groups in various organs was compared at each scan phase. Results: The aortic and arterial enhancements in the first-phase scan were higher for the 25-s group than those of the 35-s group (P < .001). Hepatic enhancement was higher for the 35-s group in the first (P < .001) and second (P < .01) phases, but no difference in the third-phase. No difference was found between the groups for the pancreatic enhancement at any phases. Qualitative results were in good agreement with quantitative results. Conclusion: Contrast administration with shorter injection duration increased peak aortic and arterial enhancement and contributed to improvement in the quality of CT angiograms, but for the solid abdominal organs 35-s protocol is recommended.

  7. MDCT diagnostic work-up of patients with subarachnoid haemorrhage

    International Nuclear Information System (INIS)

    Phanis, S.; Nikolopoulos, P.; Veliou, K.; Tsampoulas, C.; Efremidis, S.

    2006-01-01

    haemorrhage, performed in the new MDCT Computed Tomographs (16 Detectors), is a fast, minimally invasive, well tolerated, and a diagnostic method gradually gaining international recognition by radiologists as well as by clinical doctors, especially as the experience of radiologists in the method is increasing. Digital Subtraction Angiography still remains the Gold Standard method of examination, the trend though appears to be in favor for MDCT Angiography. We are anxiously awaiting for the primary results from the newest 64 Detector and 256 Detector Computed Tomographs

  8. Radiation-induced temporary hair loss as a radiation damage only occurring in patients who had the combination of MDCT and DSA

    International Nuclear Information System (INIS)

    Imanishi, Yoshimasa; Fukui, Atsushi; Itoh, Daisuke; Nozaki, Kyouko; Nakaji, Shunsuke; Ishizuka, Kumiko; Nakajima, Yasuo; Niimi, Hiroshi; Tabata, Hitoshi; Arima, Shiro; Furuya, Yu; Uzura, Masahiko; Takahama, Hideto; Hashizume, Suzuo

    2005-01-01

    As imaging technologies become increasingly advanced, it is possible to obtain detailed morphological information as well as functional imaging data. In some imaging technologies, the radiation dose increases with the ability to obtain better images or more detailed information. We encountered three cases of temporary bandage-shaped hair loss, which was caused by perfusion studies of the head by multi-detector row computed tomography (MDCT) for evaluation of cerebral blood flow in patients with vascular disorders. In all three patients with temporary hair loss, two angiographies of the head had been performed in the period of serial CT examinations. This suggested the possibility that radiation exposure from angiography performed in serial examinations, combined with the perfusion studies of the head with MDCT, played an important role in this temporary, bandage-shaped hair loss. Radiologists should be aware that a cumulative or multiplier effect of radiation exposure from multiple diagnostic techniques may result in hair loss and other types of radiation complications. (orig.)

  9. 16-slice MDCT arthrography of the shoulder: accuracy for detection of glenoid labral and rotator cuff tears

    International Nuclear Information System (INIS)

    Kim, Gang Deuk; Kim, Huoung Jun; Kim, Hye Won; Oh, Jung Taek; Juhng, Seon Kwan; Lee, Sung Ah

    2007-01-01

    We wanted to determine the diagnostic accuracy of 16-slice MDCT arthrography (CTA) for glenoid labral and rotator cuff tears of the shoulder. We enrolled forty-five patients who underwent arthroscopy after CTA for pain or instability of the shoulder joint. The CTA images were analyzed for the existence, sites and types of glenoid labral tears and the presence and severity of rotator cuff tears. We determined the sensitivity, specificity and accuracy of CTA for detecting glenoid labral and rotator cuff tears on the basis of the arthroscopy findings. At arthroscopy, there were 33 SLAP lesions (9 type I, 23 type II and 1 type III), 6 Bankart lesions and 31 rotator cuff lesions (21 supraspinatus, 9 infraspinatus and 1 subscapularis). On CTA, the sensitivity, specificity and accuracy for detecting 24 SLAP lesions, excluding the type I lesions, were 83%, 100% and 91%, the total rotator cuff tears were 90%, 100% and 98%, the full thickness supraspinatus tendon tears were 100%, 94% and 96%, and the partial thickness supraspinatus tendon tears were 29%, 100% and 89%, respectively. 16-slice MDCT arthrography has high accuracy for the diagnosis of abnormality of the glenoid labrum or rotator cuff tears and it can be a useful alternative to MRI or US

  10. 16-slice MDCT arthrography of the shoulder: accuracy for detection of glenoid labral and rotator cuff tears

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Gang Deuk; Kim, Huoung Jun; Kim, Hye Won; Oh, Jung Taek; Juhng, Seon Kwan [Wonkwang University Hospital, Iksan (Korea, Republic of); Lee, Sung Ah [Seoul Medical Center, Seoul (Korea, Republic of)

    2007-04-15

    We wanted to determine the diagnostic accuracy of 16-slice MDCT arthrography (CTA) for glenoid labral and rotator cuff tears of the shoulder. We enrolled forty-five patients who underwent arthroscopy after CTA for pain or instability of the shoulder joint. The CTA images were analyzed for the existence, sites and types of glenoid labral tears and the presence and severity of rotator cuff tears. We determined the sensitivity, specificity and accuracy of CTA for detecting glenoid labral and rotator cuff tears on the basis of the arthroscopy findings. At arthroscopy, there were 33 SLAP lesions (9 type I, 23 type II and 1 type III), 6 Bankart lesions and 31 rotator cuff lesions (21 supraspinatus, 9 infraspinatus and 1 subscapularis). On CTA, the sensitivity, specificity and accuracy for detecting 24 SLAP lesions, excluding the type I lesions, were 83%, 100% and 91%, the total rotator cuff tears were 90%, 100% and 98%, the full thickness supraspinatus tendon tears were 100%, 94% and 96%, and the partial thickness supraspinatus tendon tears were 29%, 100% and 89%, respectively. 16-slice MDCT arthrography has high accuracy for the diagnosis of abnormality of the glenoid labrum or rotator cuff tears and it can be a useful alternative to MRI or US.

  11. Evaluation of right ventricular function with multidetector computed tomography: comparison with magnetic resonance imaging and analysis of inter- and intraobserver variability

    Energy Technology Data Exchange (ETDEWEB)

    Mueller, Mira; Teige, Florian; Schnapauff, Dirk; Hamm, Bernd; Dewey, Marc [Humboldt-Universitaet zu Berlin, Department of Radiology, Charite, Medical School, Berlin, PO Box 10098 (Germany)

    2009-02-15

    This study was performed to prospectively compare multidetector computed tomography (MDCT) with 16 simultaneous sections and magnetic resonance imaging (MRI) for the assessment of global right ventricular function in 50 patients. MDCT using a semiautomatic analysis tool showed good correlation with MRI for end-diastolic volume (EDV, r=0.83, p<0.001), end-systolic volume (ESV, r=0.86, p<0.001) and stroke volume (SV, r=0.74, p<0.001), but only a moderate correlation for the ejection fraction (EF, r=0.67, p<0.001). Bland Altman analysis revealed a slight, but insignificant overestimation of EDV (4.0 ml, p= 0.08) and ESV (2.4 ml, p=0.07), and underestimation of EF (0.1%, p=0.92) with MDCT compared with MRI. All limits of agreement between both modalities (EF: {+-}15.7%, EDV: {+-}31.0 ml, ESV: {+-}18.0 ml) were in a moderate but acceptable range. Interobserver variability of MDCT was not significantly different from that of MRI. For MDCT software, the post-processing time was significantly longer (19.6{+-}5.8 min) than for MRI (11.8{+-}2.6 min, p<0.001). Accurate assessment of right ventricular volumes by 16-detector CT is feasible but still rather time-consuming. (orig.)

  12. Underestimation of risk due to exposure misclassification

    DEFF Research Database (Denmark)

    Grandjean, Philippe; Budtz-Jørgensen, Esben; Keiding, Niels

    2004-01-01

    Exposure misclassification constitutes a major obstacle when developing dose-response relationships for risk assessment. A non-differentional error results in underestimation of the risk. If the degree of misclassification is known, adjustment may be achieved by sensitivity analysis. The purpose...

  13. The development, validation and application of a multi-detector CT (MDCT) scanner model for assessing organ doses to the pregnant patient and the fetus using Monte Carlo simulations

    Science.gov (United States)

    Gu, J.; Bednarz, B.; Caracappa, P. F.; Xu, X. G.

    2009-05-01

    The latest multiple-detector technologies have further increased the popularity of x-ray CT as a diagnostic imaging modality. There is a continuing need to assess the potential radiation risk associated with such rapidly evolving multi-detector CT (MDCT) modalities and scanning protocols. This need can be met by the use of CT source models that are integrated with patient computational phantoms for organ dose calculations. Based on this purpose, this work developed and validated an MDCT scanner using the Monte Carlo method, and meanwhile the pregnant patient phantoms were integrated into the MDCT scanner model for assessment of the dose to the fetus as well as doses to the organs or tissues of the pregnant patient phantom. A Monte Carlo code, MCNPX, was used to simulate the x-ray source including the energy spectrum, filter and scan trajectory. Detailed CT scanner components were specified using an iterative trial-and-error procedure for a GE LightSpeed CT scanner. The scanner model was validated by comparing simulated results against measured CTDI values and dose profiles reported in the literature. The source movement along the helical trajectory was simulated using the pitch of 0.9375 and 1.375, respectively. The validated scanner model was then integrated with phantoms of a pregnant patient in three different gestational periods to calculate organ doses. It was found that the dose to the fetus of the 3 month pregnant patient phantom was 0.13 mGy/100 mAs and 0.57 mGy/100 mAs from the chest and kidney scan, respectively. For the chest scan of the 6 month patient phantom and the 9 month patient phantom, the fetal doses were 0.21 mGy/100 mAs and 0.26 mGy/100 mAs, respectively. The paper also discusses how these fetal dose values can be used to evaluate imaging procedures and to assess risk using recommendations of the report from AAPM Task Group 36. This work demonstrates the ability of modeling and validating an MDCT scanner by the Monte Carlo method, as well as

  14. The development, validation and application of a multi-detector CT (MDCT) scanner model for assessing organ doses to the pregnant patient and the fetus using Monte Carlo simulations

    International Nuclear Information System (INIS)

    Gu, J; Bednarz, B; Caracappa, P F; Xu, X G

    2009-01-01

    The latest multiple-detector technologies have further increased the popularity of x-ray CT as a diagnostic imaging modality. There is a continuing need to assess the potential radiation risk associated with such rapidly evolving multi-detector CT (MDCT) modalities and scanning protocols. This need can be met by the use of CT source models that are integrated with patient computational phantoms for organ dose calculations. Based on this purpose, this work developed and validated an MDCT scanner using the Monte Carlo method, and meanwhile the pregnant patient phantoms were integrated into the MDCT scanner model for assessment of the dose to the fetus as well as doses to the organs or tissues of the pregnant patient phantom. A Monte Carlo code, MCNPX, was used to simulate the x-ray source including the energy spectrum, filter and scan trajectory. Detailed CT scanner components were specified using an iterative trial-and-error procedure for a GE LightSpeed CT scanner. The scanner model was validated by comparing simulated results against measured CTDI values and dose profiles reported in the literature. The source movement along the helical trajectory was simulated using the pitch of 0.9375 and 1.375, respectively. The validated scanner model was then integrated with phantoms of a pregnant patient in three different gestational periods to calculate organ doses. It was found that the dose to the fetus of the 3 month pregnant patient phantom was 0.13 mGy/100 mAs and 0.57 mGy/100 mAs from the chest and kidney scan, respectively. For the chest scan of the 6 month patient phantom and the 9 month patient phantom, the fetal doses were 0.21 mGy/100 mAs and 0.26 mGy/100 mAs, respectively. The paper also discusses how these fetal dose values can be used to evaluate imaging procedures and to assess risk using recommendations of the report from AAPM Task Group 36. This work demonstrates the ability of modeling and validating an MDCT scanner by the Monte Carlo method, as well as

  15. Monte Carlo simulations in multi-detector CT (MDCT) for two PET/CT scanner models using MASH and FASH adult phantoms

    Energy Technology Data Exchange (ETDEWEB)

    Belinato, W., E-mail: wbfisica@gmail.com [Bahia Federal Institute of Education, Science and Technology – IFBA, Vitória da Conquista, 45.100-000 (Brazil); Department of Physics, Federal University of Sergipe – UFS, São Cristóvão, 49.100-000 (Brazil); Santos, W.S. [Department of Physics, Federal University of Sergipe – UFS, São Cristóvão, 49.100-000 (Brazil); Paschoal, C.M.M., E-mail: cinthiam.paschoal@gmail.com [Department of Civil Engineering, Vale do Acarau State University – UVA, Sobral 62.040-730 (Brazil); Souza, D.N. [Department of Physics, Federal University of Sergipe – UFS, São Cristóvão, 49.100-000 (Brazil)

    2015-06-01

    The combination of positron emission tomography (PET) and computed tomography (CT) has been extensively used in oncology for diagnosis and staging of tumors, radiotherapy planning and follow-up of patients with cancer, as well as in cardiology and neurology. This study determines by the Monte Carlo method the internal organ dose deposition for computational phantoms created by multidetector CT (MDCT) beams of two PET/CT devices operating with different parameters. The different MDCT beam parameters were largely related to the total filtration that provides a beam energetic change inside the gantry. This parameter was determined experimentally with the Accu-Gold Radcal measurement system. The experimental values of the total filtration were included in the simulations of two MCNPX code scenarios. The absorbed organ doses obtained in MASH and FASH phantoms indicate that bowtie filter geometry and the energy of the X-ray beam have significant influence on the results, although this influence can be compensated by adjusting other variables such as the tube current–time product (mAs) and pitch during PET/CT procedures.

  16. Assessment of coronary calcification using calibrated mass score with two different multidetector computed tomography scanners in the Copenhagen General Population Study

    Energy Technology Data Exchange (ETDEWEB)

    Fuchs, Andreas [Department of Cardiology, The Heart Centre, Rigshospitalet, University of Copenhagen, Copenhagen (Denmark); Groen, Jaap M. [Department of Radiology, University of Groningen, University Medical Center Groningen (Netherlands); Department of Medical Physics, OLVG, Amsterdam (Netherlands); Arnold, Ben A. [Image Analysis, 1380 Burkesville Road, Columbia, KY (United States); Nikolovski, Sasho [Department of Radiology, University of Groningen, University Medical Center Groningen (Netherlands); Knudsen, Andreas D., E-mail: dehlbaek@gmail.com [Department of Cardiology, The Heart Centre, Rigshospitalet, University of Copenhagen, Copenhagen (Denmark); Kühl, J. Tobias [Department of Cardiology, The Heart Centre, Rigshospitalet, University of Copenhagen, Copenhagen (Denmark); Nordestgaard, Børge G. [Department of Clinical Biochemistry and the Copenhagen General Population Study, Herlev Hospital, University of Copenhagen (Denmark); Greuter, Marcel J.W. [Department of Radiology, University of Groningen, University Medical Center Groningen (Netherlands); Kofoed, Klaus F. [Department of Cardiology, The Heart Centre, Rigshospitalet, University of Copenhagen, Copenhagen (Denmark); Department of Radiology, The Diagnostic Centre, Rigshospitalet, University of Copenhagen, Copenhagen (Denmark)

    2017-03-15

    Objective: Population studies have shown coronary calcium score to improve risk stratification in subjects suspected for cardiovascular disease. The aim of this work was to assess the validity of multidetector computed tomography (MDCT) for measurement of calibrated mass scores (MS) in a phantom study, and to investigate inter-scanner variability for MS and Agaston score (AS) recorded in a population study on two different high-end MDCT scanners. Materials and methods: A calcium phantom was scanned by a first (A) and second (B) generation 320-MDCT. MS was measured for each calcium deposit from repeated measurements in each scanner and compared to known physical phantom mass. Random samples of human subjects from the Copenhagen General Population Study were scanned with scanner A (N = 254) and scanner B (N = 253) where MS and AS distributions of these two groups were compared. Results: The mean total MS of the phantom was 32.9 ± 0.8 mg and 33.1 ± 0.9 mg (p = 0.43) assessed by scanner A and B respectively – the physical calcium mass was 34.0 mg. Correlation between measured MS and physical calcium mass was R{sup 2} = 0.99 in both scanners. In the population study the median total MS was 16.8 mg (interquartile range (IQR): 3.5–81.1) and 15.8 mg (IQR: 3.8–63.4) in scanner A and B (p = 0.88). The corresponding median total AS were 92 (IQR: 23–471) and 89 (IQR: 40–384) (p = 0.64). Conclusion: Calibrated calcium mass score may be assessed with very high accuracy in a calcium phantom by different generations of 320-MDCT scanners. In population studies, it appears acceptable to pool calcium scores acquired on different 320-MDCT scanners.

  17. MRI, MDCT features, and clinical outcome of extremity leiomyosarcomas: experience in 47 patients

    Energy Technology Data Exchange (ETDEWEB)

    Gordon, Robert W.; Shinagare, Atul B. [Brigham and Women' s Hospital, Harvard Medical School, Department of Radiology, Boston, MA (United States); Tirumani, Sree Harsha; Jagannathan, Jyothi P.; Ramaiya, Nikhil H. [Brigham and Women' s Hospital, Harvard Medical School, Department of Radiology, Boston, MA (United States); Dana-Farber Cancer Institute, Harvard Medical School, Department of Imaging, Boston, MA (United States); Kurra, Vikram [Dana-Farber Cancer Institute, Harvard Medical School, Department of Imaging, Boston, MA (United States); Hornick, Jason L. [Brigham and Women' s Hospital, Harvard Medical School, Department of Pathology, Boston, MA (United States)

    2014-05-15

    To describe MRI, MDCT features, and clinical outcome of extremity leiomyosarcomas (LMS). In this IRB-approved, HIPAA-compliant retrospective study, we included 47 patients (23 women, 24 men; mean age: 55.3 years, range: 17-85 years) with pathologically confirmed extremity LMS seen at our adult tertiary cancer center between 2000 and 2012. MRI/MDCT of primary tumors in 23 patients and follow-up in all patients were reviewed by two radiologists in consensus. Clinical data were extracted from electronic medical records. Primary tumors were distributed in bones (6 out of 47), deep soft tissues (24 out of 47), and superficial soft tissues (17 out of 47). On imaging (bone = 4, deep soft tissue = 11, superficial soft tissue = 8), compared with skeletal muscle, they were T1 iso-hypointense and T2 hyperintense. Bone LMS were metaphyseal tumors with cortical destruction (3 out of 4). Deep soft-tissue LMS were large with hemorrhage (7 out of 11) and necrosis (10 out of 11). Superficial soft-tissue LMS were relatively smaller, homogeneously enhancing (6 out of 8) tumors. Distant metastases developed in 32 out of 47 patients (bone LMS [6 out of 6], deep soft-tissue LMS [18 out of 24], superficial soft-tissue LMS [8 out of 17]), commonly to lung (29 out of 47) and bone (14 out of 47). At the time of writing, 22 out of 36 patients (bone LMS [4 out of 6], deep soft-tissue LMS [15 out of 24], superficial soft-tissue LMS [4 out of 17]) have died. There was no statistically significant correlation between metastatic disease and tumor size or grade. Extremity LMS arise in bones and in the deep and superficial soft tissues, frequently metastasize to the lungs, and have a poor prognosis. Superficial LMS tend to have a better prognosis than bone or deep soft-tissue LMS. (orig.)

  18. MRI, MDCT features, and clinical outcome of extremity leiomyosarcomas: experience in 47 patients

    International Nuclear Information System (INIS)

    Gordon, Robert W.; Shinagare, Atul B.; Tirumani, Sree Harsha; Jagannathan, Jyothi P.; Ramaiya, Nikhil H.; Kurra, Vikram; Hornick, Jason L.

    2014-01-01

    To describe MRI, MDCT features, and clinical outcome of extremity leiomyosarcomas (LMS). In this IRB-approved, HIPAA-compliant retrospective study, we included 47 patients (23 women, 24 men; mean age: 55.3 years, range: 17-85 years) with pathologically confirmed extremity LMS seen at our adult tertiary cancer center between 2000 and 2012. MRI/MDCT of primary tumors in 23 patients and follow-up in all patients were reviewed by two radiologists in consensus. Clinical data were extracted from electronic medical records. Primary tumors were distributed in bones (6 out of 47), deep soft tissues (24 out of 47), and superficial soft tissues (17 out of 47). On imaging (bone = 4, deep soft tissue = 11, superficial soft tissue = 8), compared with skeletal muscle, they were T1 iso-hypointense and T2 hyperintense. Bone LMS were metaphyseal tumors with cortical destruction (3 out of 4). Deep soft-tissue LMS were large with hemorrhage (7 out of 11) and necrosis (10 out of 11). Superficial soft-tissue LMS were relatively smaller, homogeneously enhancing (6 out of 8) tumors. Distant metastases developed in 32 out of 47 patients (bone LMS [6 out of 6], deep soft-tissue LMS [18 out of 24], superficial soft-tissue LMS [8 out of 17]), commonly to lung (29 out of 47) and bone (14 out of 47). At the time of writing, 22 out of 36 patients (bone LMS [4 out of 6], deep soft-tissue LMS [15 out of 24], superficial soft-tissue LMS [4 out of 17]) have died. There was no statistically significant correlation between metastatic disease and tumor size or grade. Extremity LMS arise in bones and in the deep and superficial soft tissues, frequently metastasize to the lungs, and have a poor prognosis. Superficial LMS tend to have a better prognosis than bone or deep soft-tissue LMS. (orig.)

  19. Selection of peripheral intravenous catheters with 24-gauge side-holes versus those with 22-gauge end-hole for MDCT: A prospective randomized study

    Energy Technology Data Exchange (ETDEWEB)

    Tamura, Akio, E-mail: a.akahane@gmail.com [Department of Radiology, Iwate Medical University School of Medicine, 19-1 Uchimaru, Morioka 020-8505 (Japan); Kato, Kenichi, E-mail: kkato@iwate-med.ac.jp [Department of Radiology, Iwate Medical University School of Medicine, 19-1 Uchimaru, Morioka 020-8505 (Japan); Kamata, Masayoshi, E-mail: kamataaoi@yahoo.co.jp [Iwate Medical University Hospital, 19-1 Uchimaru, Morioka 020-8505 (Japan); Suzuki, Tomohiro, E-mail: suzukitomohiro123@gmail.com [Department of Radiology, Iwate Medical University School of Medicine, 19-1 Uchimaru, Morioka 020-8505 (Japan); Suzuki, Michiko, E-mail: mamimichiko@me.com [Department of Radiology, Iwate Medical University School of Medicine, 19-1 Uchimaru, Morioka 020-8505 (Japan); Nakayama, Manabu, E-mail: gakuymgt@yahoo.co.jp [Department of Radiology, Iwate Medical University School of Medicine, 19-1 Uchimaru, Morioka 020-8505 (Japan); Tomabechi, Makiko, E-mail: mtomabechi@mac.com [Department of Radiology, Iwate Medical University School of Medicine, 19-1 Uchimaru, Morioka 020-8505 (Japan); Nakasato, Tatsuhiko, E-mail: nakasato77@gmail.com [Department of Radiology, Southern Tohoku Research Institute for Neuroscience, 7-115 Yatsuyamada, Koriyama 963-8563 (Japan); Ehara, Shigeru, E-mail: ehara@iwate-med.ac.jp [Department of Radiology, Iwate Medical University School of Medicine, 19-1 Uchimaru, Morioka 020-8505 (Japan)

    2017-02-15

    Highlights: • We compared 24-gauge side-hole and conventional 22-gauge end-hole catheters in MDCT. • The 24-gauge side-hole catheter is noninferior to the 22-gauge end-hole catheter. • The 24-gauge side-hole catheter is safe and facilitates optimal enhancement quality. • The 24-gauge side-hole catheter is suitable for patients with narrow or fragile veins. - Abstract: Purpose: To compare the 24-gauge side-holes catheter and conventional 22-gauge end-hole catheter in terms of safety, injection pressure, and contrast enhancement on multi-detector computed tomography (MDCT). Materials & methods: In a randomized single-center study, 180 patients were randomized to either the 24-gauge side-holes catheter or the 22-gauge end-hole catheter groups. The primary endpoint was safety during intravenous administration of contrast material for MDCT, using a non-inferiority analysis (lower limit 95% CI greater than −10% non-inferiority margin for the group difference). The secondary endpoints were injection pressure and contrast enhancement. Results: A total of 174 patients were analyzed for safety during intravenous contrast material administration for MDCT. The overall extravasation rate was 1.1% (2/174 patients); 1 (1.2%) minor episode occurred in the 24-gauge side-holes catheter group and 1 (1.1%) in the 22-gauge end-hole catheter group (difference: 0.1%, 95% CI: −3.17% to 3.28%, non-inferiority P = 1). The mean maximum pressure was higher with the 24-gauge side-holes catheter than with the 22-gauge end-hole catheter (8.16 ± 0.95 kg/cm{sup 2} vs. 4.79 ± 0.63 kg/cm{sup 2}, P < 0.001). The mean contrast enhancement of the abdominal aorta, celiac artery, superior mesenteric artery, and pancreatic parenchyma in the two groups were not significantly different. Conclusion: In conclusion, our study showed that the 24-gauge side-holes catheter is safe and suitable for delivering iodine with a concentration of 300 mg/mL at a flow-rate of 3 mL/s, and it may contribute to

  20. In-vivo assessment of femoral bone strength using Finite Element Analysis (FEA based on routine MDCT imaging: a preliminary study on patients with vertebral fractures.

    Directory of Open Access Journals (Sweden)

    Hans Liebl

    Full Text Available To experimentally validate a non-linear finite element analysis (FEA modeling approach assessing in-vitro fracture risk at the proximal femur and to transfer the method to standard in-vivo multi-detector computed tomography (MDCT data of the hip aiming to predict additional hip fracture risk in subjects with and without osteoporosis associated vertebral fractures using bone mineral density (BMD measurements as gold standard.One fresh-frozen human femur specimen was mechanically tested and fractured simulating stance and clinically relevant fall loading configurations to the hip. After experimental in-vitro validation, the FEA simulation protocol was transferred to standard contrast-enhanced in-vivo MDCT images to calculate individual hip fracture risk each for 4 subjects with and without a history of osteoporotic vertebral fractures matched by age and gender. In addition, FEA based risk factor calculations were compared to manual femoral BMD measurements of all subjects.In-vitro simulations showed good correlation with the experimentally measured strains both in stance (R2 = 0.963 and fall configuration (R2 = 0.976. The simulated maximum stress overestimated the experimental failure load (4743 N by 14.7% (5440 N while the simulated maximum strain overestimated by 4.7% (4968 N. The simulated failed elements coincided precisely with the experimentally determined fracture locations. BMD measurements in subjects with a history of osteoporotic vertebral fractures did not differ significantly from subjects without fragility fractures (femoral head: p = 0.989; femoral neck: p = 0.366, but showed higher FEA based risk factors for additional incident hip fractures (p = 0.028.FEA simulations were successfully validated by elastic and destructive in-vitro experiments. In the subsequent in-vivo analyses, MDCT based FEA based risk factor differences for additional hip fractures were not mirrored by according BMD measurements. Our data suggests, that MDCT

  1. Step-and-shoot prospectively ECG-gated versus retrospectively ECG-gated with tube current modulation coronary CT angiography using the 128-slice MDCT: comparison of image quality and radiation dose

    International Nuclear Information System (INIS)

    Jeong, Dong Wook; Choo, Ki Seok; Baik, Seung Kug; Kim, Yong Woo; Jeon, Ung Bae; Kim, Jeong Soo; Lim, Soo Jin

    2011-01-01

    Background: Little is known regarding image quality and the required radiation dose for step-and-shoot and retrospective coronary computed tomography angiography (CCTA) with tube current modulation (TCM) in 128-slice multidetector CT (MDCT) coronary angiography. Purpose: To compare image quality and radiation dose in patients who underwent 128-slice MDCT by the step-and- shoot method with those in patients who underwent 128-slice MDCT with retrospective CCTA with TCM. Material and Methods: CCTA obtained with 128-slice MDCT was retrospectively evaluated in 160 patients. Two independent reviewers separately scored the subjective image quality of the coronary artery segments (1, excellent; 4, poor) for step-and-shoot (68, mean heart rate [HR]: 59.3±6.8) and retrospective CCTA with TCM (77, mean HR: 59.1±9.8). Interobserver variability was calculated. Effective radiation doses of both scan techniques were calculated with dose-length product. Results: There was good agreement for quality scores of coronary artery segment images between the independent reviewers (k=0.72). The number of coronary artery segments that could not be evaluated was 2.85% (27 of 947) in the step-and-shoot and 1.87% (20 of 1071) in retrospective CCTA with TCM. Image quality scores were not significantly different (P>.05). Mean patient radiation dose was 63% lower for step-and-shoot (1.94±0.70 mSv) than for retrospective CCTA with TCM (4.51±1.18 mSv) (P<0.0001). For patients who underwent step-and-shoot or retrospective CCTA with TCM, an average HR of 63.5 beats per minute was identified as the threshold for the prediction of non-diagnostic image quality for both protocols. There were no significant differences in the image quality of both methods between obese (body mass index [BMI≥25) and non-obese patients (BMI<25), but radiation doses were higher in the obesity group than in the non-obesity group for both methods. Conclusion: Both step-and-shoot and retrospective CCTA with TCM using 128

  2. Acute Knee Trauma: Analysis of Multidetector Computed Tomography Findings and Comparison with Conventional Radiography

    International Nuclear Information System (INIS)

    Mustonen, A.O.T.; Kiuru, M.J.

    2005-01-01

    Purpose: To evaluate the multidetector computed tomography (MDCT) findings of acute knee trauma and to compare radiography with MDCT in patients referred ta level 1 trauma center. Material and Methods: During a 5-year period, a total of 415 MDCT examinations were performed on 409 patients with acute knee trauma to reveal complex fracture anatomy or rule out a fracture. MDCT and primary radiographs were re-evaluated with respect to fracture location and trauma mechanism. Tibial plateau fractures were further analyzed depending on anatomical location: anterior-medial, anterior-lateral, posterior-lateral, and posterior-medial regions. Maximal depression of the tibial articular surface was measured. Findings on the primary knee radiographs were compared with MDCT findings. Results: Of the 409 patients, 356 (87%) had a knee fracture. A total of 451 fractures were found in all anatomic regions: distal femur ( n = 49), proximal tibia ( n 307), patella ( n = 23), and proximal fibula ( n = 72). Primary radiographs were available in 316 (76%) cases. Of these, 225 (71%) had MDCT in order to reveal the fracture anatomy better, and 91 (29%) had a subsequent MDCT after negative plain radiographs. Overall sensitivity of radiography was 83%, while negative predictive value was 49%. On radiography, tibial plateau articular depression was underestimated in all regions except when the fracture consisted of the whole half of the anterior or posterior plateau. The three main injury mechanisms were traffic accident, a simple fall, and sport. In 49 cases (15%), primary radiographs were suboptimal due to positioning. Conclusion: In severely injured patients, diagnostically sufficient radiographs are difficult to obtain, and therefore a negative radiograph is not reliable in ruling out a fracture. In these patients, MDCT is a fast and accurate examination and is also recommended in patients with tibial plateau fractures or complex knee injuries in order to evaluate the fracture adequately

  3. The value of coronal image reconstructions of HRCT using MDCT for the assessment of bronchiectasis: experiment with 64 MDCTs

    International Nuclear Information System (INIS)

    Choi, Soo Jin; Kim, Hyung Sik; Jeong, Sung Hwan; Jin, Wook; Yang, Dal Mo

    2006-01-01

    The aim of our study was to evaluate the value of coronal image reconstructions of HRCT with using 64 MDCT scans for the assessment of bronchiectasis. Chest CT scans (0.6-mm collimation, table speed of 14 mm/sec and a rotation time of 0.5 sec) that employed 64 MDCT images (Somatom Sensation 64, Siemens) without contrast media were performed in 56 patients (21 males and 35 females, mean age: 55 years) who displayed hemoptysis. The images were reconstructed with a 1 mm slice thickness in the axial (10 mm apart) and coronal (10 mm apart) planes with using a high frequency algorithm, and they were sent to PACS monitors. The axial images were assessed with and without the coronal images by two radiologists at two separate occasions. The presence of bronchiectasis was decided upon by consensus diagnosis of the two radiologists. The detection rates of bronchiectasis were compared between the readings with using the axial images alone and the readings with using both the axial and coronal images. The detection rate of bronchiectasis was significantly higher with using both the axial and coronal images than with using with axial images alone (82.1%, 46/56 patients Vs 64.3%, 36/56 patients, respectively, ρ = 0.001). The detection rates for all the lobes, except for the superior division of the left upper lobe, were significantly improved with using both the axial and coronal images (RUL; ρ = 0.013, RML; ρ = 0.002, RLL; 0.024, Lt lingular segment; ρ = 0.004, LLL; ρ = 0.018). The coronal images of HRCT with using 64 MDCT improved the detection rate of bronchiectasis in the patients with hemoptysis when they were used in conjunction with the standard axial images. We suggest that HRCT with the coronal images should be obtained for the patients with hemoptysis, despite that the simple chest radiographs are often normal or they have non-specific findings

  4. The value of coronal image reconstructions of HRCT using MDCT for the assessment of bronchiectasis: experiment with 64 MDCTs

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Soo Jin; Kim, Hyung Sik; Jeong, Sung Hwan; Jin, Wook; Yang, Dal Mo [Gachon University of Medicine and Science, Incheon (Korea, Republic of)

    2006-09-15

    The aim of our study was to evaluate the value of coronal image reconstructions of HRCT with using 64 MDCT scans for the assessment of bronchiectasis. Chest CT scans (0.6-mm collimation, table speed of 14 mm/sec and a rotation time of 0.5 sec) that employed 64 MDCT images (Somatom Sensation 64, Siemens) without contrast media were performed in 56 patients (21 males and 35 females, mean age: 55 years) who displayed hemoptysis. The images were reconstructed with a 1 mm slice thickness in the axial (10 mm apart) and coronal (10 mm apart) planes with using a high frequency algorithm, and they were sent to PACS monitors. The axial images were assessed with and without the coronal images by two radiologists at two separate occasions. The presence of bronchiectasis was decided upon by consensus diagnosis of the two radiologists. The detection rates of bronchiectasis were compared between the readings with using the axial images alone and the readings with using both the axial and coronal images. The detection rate of bronchiectasis was significantly higher with using both the axial and coronal images than with using with axial images alone (82.1%, 46/56 patients Vs 64.3%, 36/56 patients, respectively, {rho} = 0.001). The detection rates for all the lobes, except for the superior division of the left upper lobe, were significantly improved with using both the axial and coronal images (RUL; {rho} = 0.013, RML; {rho} = 0.002, RLL; 0.024, Lt lingular segment; {rho} = 0.004, LLL; {rho} = 0.018). The coronal images of HRCT with using 64 MDCT improved the detection rate of bronchiectasis in the patients with hemoptysis when they were used in conjunction with the standard axial images. We suggest that HRCT with the coronal images should be obtained for the patients with hemoptysis, despite that the simple chest radiographs are often normal or they have non-specific findings.

  5. Depiction of normal gastrointestinal anatomy with MDCT: Comparison of low- and high-attenuation oral contrast media

    International Nuclear Information System (INIS)

    Erturk, Sukru Mehmet; Mortele, Koenraad J.; Oliva, Maria-Raquel; Ichikawa, Tomoaki; Silverman, Stuart G.; Cantisani, Vito; Pagliara, Elisa; Ros, Pablo R.

    2008-01-01

    Purpose: To compare low- and high-attenuation oral contrast media for depiction of normal gastrointestinal anatomy with multidetector-row computed tomography (MDCT). Materials and methods: A prospective, randomized study of 90 consecutive patients without known or suspected gastrointestinal disease was conducted after the approval of our Institutional Review Board. All patients underwent IV contrast-enhanced abdominal and pelvic CT scans after oral administration of 900 ml of either low- or high-attenuation barium sulphate suspension. Using a five-point scale, two radiologists independently graded distention and wall visualization of stomach, duodenum, jejunum, and ileum. The degree of distention and wall visualization was compared using Mann-Whitney U-test. Results: Duodenal, jejunal and ileal distention (p < 0.05, <0.001, <0.001, respectively) and wall visualization (p < 0.05, <0.01, <0.05, respectively) scores with low-attenuation contrast medium were significantly higher than those with high-attenuation barium sulphate preparation, for reader 1. Duodenal and jejunal wall visualization scores with low-attenuation contrast medium (p < 0.05, <0.01, respectively) were significantly higher than those with high-attenuation contrast medium, for reader 2. Interobserver agreement was fair to good for both distention (κ-range: 0.41-0.74) and wall visualization (κ-range: 0.48-0.71). Conclusion: MDCT with low-attenuation contrast medium provides distention and wall visualization of the GI tract that is equal or better than high-attenuation contrast medium

  6. Commonly used reference values underestimate oxygen uptake in healthy, 50-year-old Swedish women.

    Science.gov (United States)

    Genberg, M; Andrén, B; Lind, L; Hedenström, H; Malinovschi, A

    2018-01-01

    Cardiopulmonary exercise testing (CPET) is the gold standard among clinical exercise tests. It combines a conventional stress test with measurement of oxygen uptake (V O 2 ) and CO 2 production. No validated Swedish reference values exist, and reference values in women are generally understudied. Moreover, the importance of achieved respiratory exchange ratio (RER) and the significance of breathing reserve (BR) at peak exercise in healthy individuals are poorly understood. We compared V O 2 at maximal load (peakV O 2 ) and anaerobic threshold (V O 2@ AT ) in healthy Swedish individuals with commonly used reference values, taking gender into account. Further, we analysed maximal workload and peakV O 2 with regard to peak RER and BR. In all, 181 healthy, 50-year-old individuals (91 women) performed CPET. PeakV O 2 was best predicted using Jones et al. (100·5%), while SHIP reference values underestimated peakV O 2 most: 112·5%. Furthermore, underestimation of peakV O 2 in women was found for all studied reference values (P 1·1 (2 328·7 versus 2 176·7 ml min -1 , P = 0·11). Lower BR (≤30%) related to significantly higher peakV O 2 (Pvalues underestimated oxygen uptake in women. No evidence for demanding RER > 1·1 in healthy individuals was found. A lowered BR is probably a normal response to higher workloads in healthy individuals. © 2016 Scandinavian Society of Clinical Physiology and Nuclear Medicine. Published by John Wiley & Sons Ltd.

  7. Automated diagnosis of interstitial lung diseases and emphysema in MDCT imaging

    Science.gov (United States)

    Fetita, Catalin; Chang Chien, Kuang-Che; Brillet, Pierre-Yves; Prêteux, Françoise

    2007-09-01

    Diffuse lung diseases (DLD) include a heterogeneous group of non-neoplasic disease resulting from damage to the lung parenchyma by varying patterns of inflammation. Characterization and quantification of DLD severity using MDCT, mainly in interstitial lung diseases and emphysema, is an important issue in clinical research for the evaluation of new therapies. This paper develops a 3D automated approach for detection and diagnosis of diffuse lung diseases such as fibrosis/honeycombing, ground glass and emphysema. The proposed methodology combines multi-resolution 3D morphological filtering (exploiting the sup-constrained connection cost operator) and graph-based classification for a full characterization of the parenchymal tissue. The morphological filtering performs a multi-level segmentation of the low- and medium-attenuated lung regions as well as their classification with respect to a granularity criterion (multi-resolution analysis). The original intensity range of the CT data volume is thus reduced in the segmented data to a number of levels equal to the resolution depth used (generally ten levels). The specificity of such morphological filtering is to extract tissue patterns locally contrasting with their neighborhood and of size inferior to the resolution depth, while preserving their original shape. A multi-valued hierarchical graph describing the segmentation result is built-up according to the resolution level and the adjacency of the different segmented components. The graph nodes are then enriched with the textural information carried out by their associated components. A graph analysis-reorganization based on the nodes attributes delivers the final classification of the lung parenchyma in normal and ILD/emphysematous regions. It also makes possible to discriminate between different types, or development stages, among the same class of diseases.

  8. Consideration of Adverse Reaction to MDCT Contrast Media

    International Nuclear Information System (INIS)

    Yang, Won Seok; Shin, Seong Gyu

    2012-01-01

    In this experiment, we investigated 82 patients who suffered adverse reactions due to contrast medium. We selected the subjects out of 21,178 people who had an intravenous injection of contrast medium to undergo MDCT examination at one university hospital in Busan in 2007. As a result, the largest groups of the patients were as follows. 52.4% of the patients were male when classify by gender; 28.0% of the patients were 50's by age; 45% of the patients got when it was spring(April and March); 75.6% of the patients had a side effects when the speed of injection is 2.5 mL/sec; 58.5% of the patients were suffered when the volume of injected contrast medium is over 130 mL. Urticaria was the main symptom of side effect as 26.8%. And the main treatment for the effect was alleviating the symptoms before making patients to return home. Thus, practical preventive measures are needed as follows: use the OCS system to observe warning signs at risky patients, secure warming spaces for patients to cope with season changing, prepare enough emergency kits for the patients in danger, and establish CPR call systems, explain the risk of contrast medium and get agree about using contrast medium.

  9. Health-economic evaluation of three imaging strategies in patients with suspected colorectal liver metastases: Gd-EOB-DTPA-enhanced MRI vs. extracellular contrast media-enhanced MRI and 3-phase MDCT in Germany, Italy and Sweden

    International Nuclear Information System (INIS)

    Zech, C.J.; Grazioli, L.; Jonas, E.; Ekman, M.; Joensson, L.; Niebecker, R.; Kienbaum, S.; Gschwend, S.; Breuer, J.

    2009-01-01

    The purpose of this study was to perform an economic evaluation of hepatocyte-specific Gd-EOB-DTPA enhanced MRI (PV-MRI) compared to extracellular contrast-media-enhanced MRI (ECCM-MRI) and three-phase-MDCT as initial modalities in the work-up of patients with metachronous colorectal liver metastases. The economic evaluation was performed with a decision-tree model designed to estimate all aggregated costs depending on the initial investigation. Probabilities on the need for further imaging to come to a treatment decision were collected through interviews with 13 pairs of each a radiologist and a liver surgeon in Germany, Italy and Sweden. The rate of further imaging needed was 8.6% after initial PV-MRI, 18.5% after ECCM-MRI and 23.5% after MDCT. Considering the cost of all diagnostic work-up, intra-operative treatment changes and unnecessary surgery, a strategy starting with PV-MRI with 959 EUR was cost-saving compared to ECCM-MRI (1,123 EUR) and MDCT (1,044 EUR) in Sweden. In Italy and Germany, PV-MRI was cost-saving compared to ECCM-MRI and had total costs similar to MDCT. In conclusion, our results indicate that PV-MRI can lead to cost savings by improving pre-operative planning and decreasing intra-operative changes. The higher cost of imaging with PV-MRI is offset in such a scenario by lower costs for additional imaging and less intra-operative changes. (orig.)

  10. Diagnostic Value and Interreader Agreement of the Pancreaticolienal Gap in Pancreatic Cancer on MDCT.

    Directory of Open Access Journals (Sweden)

    Khoschy Schawkat

    Full Text Available The aim of this retrospective study was to evaluate the diagnostic value and measure interreader agreement of the pancreaticolienal gap (PLG in the assessment of imaging features of pancreatic carcinoma (PC on contrast-enhanced multi-detector computed tomography (CE-MDCT.CE-MDCT studies in the portal venous phase were retrospectively reviewed for 66 patients with PC. The age- and gender-matched control group comprised 103 healthy individuals. Three radiologists with different levels of experience independently measured the PLG (the minimum distance of the pancreatic tail to the nearest border of the spleen in the axial plane. The interreader agreement of the PLG and the receiver operating characteristic (ROC curve was used to calculate the accuracy of the technique.While the control group (n = 103 showed a median PLG of 3 mm (Range: 0 - 39mm the PC patients had a significantly larger PLG of 15mm (Range: 0 - 53mm(p 12 mm for PC, with a sensitivity of 58.2% (95% CI = 45.5-70.1, specificity of 84.0% (95% CI = 75.6-90.4 and an area under the ROC curve of 0.714 (95% CI = 0.641 to 0.780. The mean interreader agreement showed correlation coefficient r of 0.9159. The extent of the PLG did not correlate with tumor stage but did correlate with pancreatic density (fatty involution and age, the density decreased by 4.1 HU and the PLG increased by 0.8 mm within every 10 y.The significant interreader agreement supports the use of the PLG as a characterizing feature of pancreatic cancer independent of the tumor stage on an axial plane. The increase in the PLG with age may represent physiological atrophy of the pancreatic tail.

  11. Lateralized odontoid in plain film radiography. Sign of fractures? A comparison study with MDCT

    Energy Technology Data Exchange (ETDEWEB)

    Keller, S.; Bieck, K.; Karul, M.; Schoennagel, B.; Adam, G.; Habermann, C.; Yamamura, J. [University Hospital Hamburg Eppendorf (Germany). Dept. of Diagnostic and Interventional Radiology

    2015-09-15

    To evaluate X-ray standards for the detection of odontoid fractures. Summary of background data: Cervical spine fractures are a common finding in emergency medicine, accounting for 1 - 3 % of injuries. Involvement of the C1 / C2 complex is found in 25 % of cases, affecting the odontoid peg in 55 - 80 %. Regarding the consequences of missed fractures, radiographic techniques built the groundwork for further treatment procedures. As standardized X-ray measurements have not been established, the incidence of unrecognized cervical spine fracture is expected to be up to 20 %. The establishment of X-ray-based guidelines is also limited by the presumed low specificity and sensitivity of distance measurements caused by rotational distortion which leads to a rising popularity of CT. 79 (age 60 ± 26 yrs) patients with lateralization of the odontoid process on conventional plain film radiography (anteroposterior, lateral, and open mouth odontoid process view projection) were examined. The distance between the odontoid process and lateral mass of C1, angles of vertical odontoid line and basis of C2 were measured in the ap view. In the lateral view, dorsal alignment and atlantodental distance were assessed. MDCT examinations were used as a reference. Discriminatory power test was applied to assess significance. 8/79 (10.1 %) odontoid process fractures were found. Diagnosis was achieved on conventional radiographs in 6 patients. Neither distance and angle measurements between odontoid and C1 nor the dorsal alignment of the vertebral bodies differed significantly between healthy and affected patients. Decentralization of the odontoid process is not necessarily an indirect sign for its fracture. In patients with suspected injury of the odontoid process, an MDCT scan might be the method of choice to rule out a fracture.

  12. MDCT Anatomic Assessment of Right Inferior Phrenic Artery Origin Related to Potential Supply to Hepatocellular Carcinoma and its Embolization

    International Nuclear Information System (INIS)

    Basile, Antonio; Tsetis, Dimitrios; Montineri, Arturo; Puleo, Stefano; Massa Saluzzo, Cesare; Runza, Giuseppe; Coppolino, Francesco; Ettorre, Giovanni Carlo; Patti, Maria Teresa

    2008-01-01

    Purpose. To prospectively assess the anatomic variation of the right inferior phrenic artery (RIPA) origin with multidetector computed tomography (MDCT) scans in relation to the technical and angiographic findings during transcatheter arterial embolization of hepatocellular carcinoma (HCC). Methods. Two hundred patients with hepatocellular carcinomas were examined with 16-section CT during the arterial phase. The anatomy of the inferior phrenic arteries was recorded, with particular reference to their origin. All patients with subcapsular HCC located at segments VII and VIII underwent arteriography of the RIPA with subsequent embolization if neoplastic supply was detected. Results. The RIPA origin was detected in all cases (sensitivity 100%), while the left inferior phrenic artery origin was detected in 187 cases (sensitivity 93.5%). RIPAs originated from the aorta (49%), celiac trunk (41%), right renal artery (5.5%), left gastric artery (4%), and proper hepatic artery (0.5%), with 13 types of combinations with the left IPA. Twenty-nine patients showed subcapsular HCCs in segments VII and VIII and all but one underwent RIPA selective angiography, followed by embolization in 7 cases. Conclusion. MDCT assesses well the anatomy of RIPAs, which is fundamental for planning subsequent cannulation and embolization of extrahepatic RIPA supply to HCC

  13. Low contrast detectability and spatial resolution with model-based iterative reconstructions of MDCT images: a phantom and cadaveric study

    Energy Technology Data Exchange (ETDEWEB)

    Millon, Domitille; Coche, Emmanuel E. [Universite Catholique de Louvain, Department of Radiology and Medical Imaging, Cliniques Universitaires Saint Luc, Brussels (Belgium); Vlassenbroek, Alain [Philips Healthcare, Brussels (Belgium); Maanen, Aline G. van; Cambier, Samantha E. [Universite Catholique de Louvain, Statistics Unit, King Albert II Cancer Institute, Brussels (Belgium)

    2017-03-15

    To compare image quality [low contrast (LC) detectability, noise, contrast-to-noise (CNR) and spatial resolution (SR)] of MDCT images reconstructed with an iterative reconstruction (IR) algorithm and a filtered back projection (FBP) algorithm. The experimental study was performed on a 256-slice MDCT. LC detectability, noise, CNR and SR were measured on a Catphan phantom scanned with decreasing doses (48.8 down to 0.7 mGy) and parameters typical of a chest CT examination. Images were reconstructed with FBP and a model-based IR algorithm. Additionally, human chest cadavers were scanned and reconstructed using the same technical parameters. Images were analyzed to illustrate the phantom results. LC detectability and noise were statistically significantly different between the techniques, supporting model-based IR algorithm (p < 0.0001). At low doses, the noise in FBP images only enabled SR measurements of high contrast objects. The superior CNR of model-based IR algorithm enabled lower dose measurements, which showed that SR was dose and contrast dependent. Cadaver images reconstructed with model-based IR illustrated that visibility and delineation of anatomical structure edges could be deteriorated at low doses. Model-based IR improved LC detectability and enabled dose reduction. At low dose, SR became dose and contrast dependent. (orig.)

  14. Accuracy of MDCT in the preoperative definition of Peritoneal Cancer Index (PCI) in patients with advanced ovarian cancer who underwent peritonectomy and hyperthermic intraperitoneal chemotherapy (HIPEC).

    Science.gov (United States)

    Mazzei, Maria Antonietta; Khader, Leila; Cirigliano, Alfredo; Cioffi Squitieri, Nevada; Guerrini, Susanna; Forzoni, Beatrice; Marrelli, Daniele; Roviello, Franco; Mazzei, Francesco Giuseppe; Volterrani, Luca

    2013-12-01

    To evaluate the accuracy of MDCT in the preoperative definition of Peritoneal Cancer Index (PCI) in patients with advanced ovarian cancer who underwent a peritonectomy and hyperthermic intraperitoneal chemotherapy (HIPEC) after neoadjuvant chemotherapy to obtain a pre-surgery prognostic evaluation and a prediction of optimal cytoreduction surgery. Pre-HIPEC CT examinations of 43 patients with advanced ovarian cancer after neoadjuvant chemotherapy were analyzed by two radiologists. The PCI was scored according to the Sugarbaker classification, based on lesion size and distribution. The results were compared with macroscopic and histologic data after peritonectomy and HIPEC. To evaluate the accuracy of MDCT to detect and localize peritoneal carcinomatosis, both patient-level and regional-level analyses were conducted. A correlation between PCI CT and histologic values for each patient was searched according to the PCI grading. Considering the patient-level analysis, CT shows a sensitivity, specificity, PPV, NPV, and an accuracy in detecting the peritoneal carcinomatosis of 100 %, 40 %, 93 % 100 %, and 93 %, respectively. Considering the regional level analysis, a sensitivity, specificity, PPV, NPV, and diagnostic accuracy of 72 %, 80 %, 66 %, 84 %, and 77 %, respectively were obtained for the correlation between CT and histology. Our results encourage the use of MDCT as the only technique sufficient to select patients with peritoneal carcinomatosis for cytoreductive surgery and HIPEC on the condition that a CT examination will be performed using a dedicated protocol optimized to detect minimal peritoneal disease and CT images will be analyzed by an experienced reader.

  15. MDCT after balloon kyphoplasty: analysis of vertebral body architecture one year after treatment of osteoporotic fractures

    International Nuclear Information System (INIS)

    Roehrl, B.; Dueber, C.; Sadick, M.; Brocker, K.; Voggenreiter, G.; Obertacke, U.; Brade, J.

    2006-01-01

    Purpose: to evaluate the value of MDCT in the monitoring of vertebral body architecture after balloon kyphoplasty and observe morphological changes of the vertebral body. Material and methods: during a period of 26 months, 66 osteoporotic fractures of the vertebral bodies were treated with percutanous balloon kyphoplasty. The height of the vertebral body, width of spinal space, sagittal indices, kyphosis und COBB angle, and cement leakage were evaluated by computed tomography before and after treatment and in a long-term follow up. Statistical analysis was performed by calculating quantitative constant parameters of descriptive key data. In addition, parametric and distribution-free procedures were performed for all questions. Results: after kyphoplasty, the treated vertebral bodies showed a significant gain in the height of the leading edge (0.15 cm; p < 0.0001) and in the central part of the vertebral body (0.17 cm; p < 0.0001). The height of the trailing edge did not change significantly. A corresponding gain in the sagittal index was found. The index remained stable during follow-up. Treated vertebral bodies as well as untreated references showed a comparable loss of height over the period of one year. The shape of the vertebral bodies remained stable. In comparison to these findings, treated vertebral bodies showed a reduced loss of height. A significant change in kyphosis und the COBB angle was noted. In total, pallacos leakage was detected in 71% of cases. Conclusion: MDCT is an accurate method for evaluating vertebral body architecture after treatment with balloon kyphoplasty. (orig.)

  16. Editorial to: Baseline MDCT findings after prosthetic heart valve implantation provide important complementary information to echocardiography for follow-up purposes by Sucha et al

    Energy Technology Data Exchange (ETDEWEB)

    Peeters, F.E.C.M. [Maastricht University Medical Center, Department of Cardiology, Maastricht (Netherlands); Kietselaer, B.L.J.H. [Maastricht University Medical Center, Department of Cardiology, Maastricht (Netherlands); Maastricht University Medical Center, Department of Radiology, Maastricht (Netherlands)

    2016-04-15

    Over the last years a growing number of prosthetic heart valve (PHV) implantation procedures have been performed in sequence with the aging of the population and improving surgical techniques. Currently, echocardiography is the most important tool in the follow-up and evaluation of complications associated with the PHV (pannus, thrombus, endocarditis). However, echocardiographic examination of PHV associated disease may be hampered by poor acoustic window or scatter artefacts caused by the PHV. PHV related disease such as endocarditis is related with a poor prognosis, especially when complications such as periannular abscess formation occurs. Early treatment of PHV associated disease improves prognosis. Therefore, an unmet clinical need for early detection of complications exists. In the evaluation of PHV (dys)function, multidetector-row computed tomography (MDCT) has shown to be of additive value. A necessity for MDCT to be implemented in daily practice is to be able to distinguish between normal and pathological features. (orig.)

  17. Editorial to: Baseline MDCT findings after prosthetic heart valve implantation provide important complementary information to echocardiography for follow-up purposes by Sucha et al

    International Nuclear Information System (INIS)

    Peeters, F.E.C.M.; Kietselaer, B.L.J.H.

    2016-01-01

    Over the last years a growing number of prosthetic heart valve (PHV) implantation procedures have been performed in sequence with the aging of the population and improving surgical techniques. Currently, echocardiography is the most important tool in the follow-up and evaluation of complications associated with the PHV (pannus, thrombus, endocarditis). However, echocardiographic examination of PHV associated disease may be hampered by poor acoustic window or scatter artefacts caused by the PHV. PHV related disease such as endocarditis is related with a poor prognosis, especially when complications such as periannular abscess formation occurs. Early treatment of PHV associated disease improves prognosis. Therefore, an unmet clinical need for early detection of complications exists. In the evaluation of PHV (dys)function, multidetector-row computed tomography (MDCT) has shown to be of additive value. A necessity for MDCT to be implemented in daily practice is to be able to distinguish between normal and pathological features. (orig.)

  18. High-risk lesions diagnosed at MRI-guided vacuum-assisted breast biopsy: can underestimation be predicted?

    Energy Technology Data Exchange (ETDEWEB)

    Crystal, Pavel [Mount Sinai Hospital, University Health Network, Division of Breast Imaging, Toronto, ON (Canada); Mount Sinai Hospital, Toronto, ON (Canada); Sadaf, Arifa; Bukhanov, Karina; Helbich, Thomas H. [Mount Sinai Hospital, University Health Network, Division of Breast Imaging, Toronto, ON (Canada); McCready, David [Princess Margaret Hospital, Department of Surgical Oncology, Toronto, ON (Canada); O' Malley, Frances [Mount Sinai Hospital, Department of Pathology, Laboratory Medicine, Toronto, ON (Canada)

    2011-03-15

    To evaluate the frequency of diagnosis of high-risk lesions at MRI-guided vacuum-assisted breast biopsy (MRgVABB) and to determine whether underestimation may be predicted. Retrospective review of the medical records of 161 patients who underwent MRgVABB was performed. The underestimation rate was defined as an upgrade of a high-risk lesion at MRgVABB to malignancy at surgery. Clinical data, MRI features of the biopsied lesions, and histological diagnosis of cases with and those without underestimation were compared. Of 161 MRgVABB, histology revealed 31 (19%) high-risk lesions. Of 26 excised high-risk lesions, 13 (50%) were upgraded to malignancy. The underestimation rates of lobular neoplasia, atypical apocrine metaplasia, atypical ductal hyperplasia, and flat epithelial atypia were 50% (4/8), 100% (5/5), 50% (3/6) and 50% (1/2) respectively. There was no underestimation in the cases of benign papilloma without atypia (0/3), and radial scar (0/2). No statistically significant differences (p > 0.1) between the cases with and those without underestimation were seen in patient age, indications for breast MRI, size of lesion on MRI, morphological and kinetic features of biopsied lesions. Imaging and clinical features cannot be used reliably to predict underestimation at MRgVABB. All high-risk lesions diagnosed at MRgVABB require surgical excision. (orig.)

  19. The feasibility of a scanner-independent technique to estimate organ dose from MDCT scans: Using CTDIvol to account for differences between scanners

    International Nuclear Information System (INIS)

    Turner, Adam C.; Zankl, Maria; DeMarco, John J.; Cagnon, Chris H.; Zhang Di; Angel, Erin; Cody, Dianna D.; Stevens, Donna M.; McCollough, Cynthia H.; McNitt-Gray, Michael F.

    2010-01-01

    Purpose: Monte Carlo radiation transport techniques have made it possible to accurately estimate the radiation dose to radiosensitive organs in patient models from scans performed with modern multidetector row computed tomography (MDCT) scanners. However, there is considerable variation in organ doses across scanners, even when similar acquisition conditions are used. The purpose of this study was to investigate the feasibility of a technique to estimate organ doses that would be scanner independent. This was accomplished by assessing the ability of CTDI vol measurements to account for differences in MDCT scanners that lead to organ dose differences. Methods: Monte Carlo simulations of 64-slice MDCT scanners from each of the four major manufacturers were performed. An adult female patient model from the GSF family of voxelized phantoms was used in which all ICRP Publication 103 radiosensitive organs were identified. A 120 kVp, full-body helical scan with a pitch of 1 was simulated for each scanner using similar scan protocols across scanners. From each simulated scan, the radiation dose to each organ was obtained on a per mA s basis (mGy/mA s). In addition, CTDI vol values were obtained from each scanner for the selected scan parameters. Then, to demonstrate the feasibility of generating organ dose estimates from scanner-independent coefficients, the simulated organ dose values resulting from each scanner were normalized by the CTDI vol value for those acquisition conditions. Results: CTDI vol values across scanners showed considerable variation as the coefficient of variation (CoV) across scanners was 34.1%. The simulated patient scans also demonstrated considerable differences in organ dose values, which varied by up to a factor of approximately 2 between some of the scanners. The CoV across scanners for the simulated organ doses ranged from 26.7% (for the adrenals) to 37.7% (for the thyroid), with a mean CoV of 31.5% across all organs. However, when organ doses

  20. MDCT of primary, locally recurrent, and metastatic duodenal gastrointestinal stromal tumours (GISTs): A single institution study of 25 patients with review of literature

    International Nuclear Information System (INIS)

    Cheng, J.M.; Tirumani, S.H.; Shinagare, A.B.; Jagannathan, J.P.; Hornick, J.L.; Raut, C.P.; Ramaiya, N.H.

    2014-01-01

    Aim: To describe the multidetector computed tomography (MDCT) features of primary, locally recurrent, and metastatic duodenal gastrointestinal stromal tumours (GISTs). Materials and methods: In this institutional review board-approved, Health Insurance Portability and Accountability Act of 1996 (HIPAA)-compliant, retrospective study, 25 patients [13 men, 12 women; mean age 56 years (34–74 years)] with histopathologically confirmed duodenal GISTs seen at Dana Farber Cancer Institute and Brigham and Women's Hospital from December 1999 to October 2009 were identified. The MDCT of primary tumours in six patients and follow-up imaging in all the 25 patients was reviewed by two radiologists in consensus. Electronic medical records were reviewed to document the clinical characteristics and management. Results: The mean size of the primary tumour was 3.7 cm (range 2.5–5.6 cm). Three of six primary tumours were in the second and third portions of the duodenum, one in the third portion, one in the third and fourth portions, and one in the fourth portion. Three of six of the tumours were exophytic, two were both exophytic and intraluminal, and one was intramural. The tumours were well-circumscribed, round or oval masses, with few lobulations, and were either homogeneously hyper-enhancing or heterogeneously isodense at MDCT. None of the tumours had necrosis, haemorrhage, calcification, or loco regional lymphadenopathy on imaging. Sixteen of 25 (64%) patients developed metastatic disease, the most common sites being liver (14/16; 87.5%) and peritoneum (5/16; 31%). Conclusion: Duodenal GISTs are well-circumscribed, round or oval masses, and occur in the second through fourth portions of the duodenum, without lymphadenopathy or duodenal obstruction. Duodenal GISTS metastasize frequently to the liver and peritoneum

  1. Calorie Underestimation When Buying High-Calorie Beverages in Fast-Food Contexts.

    Science.gov (United States)

    Franckle, Rebecca L; Block, Jason P; Roberto, Christina A

    2016-07-01

    We asked 1877 adults and 1178 adolescents visiting 89 fast-food restaurants in New England in 2010 and 2011 to estimate calories purchased. Calorie underestimation was greater among those purchasing a high-calorie beverage than among those who did not (adults: 324 ±698 vs 102 ±591 calories; adolescents: 360 ±602 vs 198 ±509 calories). This difference remained significant for adults but not adolescents after adjusting for total calories purchased. Purchasing high-calorie beverages may uniquely contribute to calorie underestimation among adults.

  2. Usefulness of 64-slice MDCT for follow-up of young children with coronary artery aneurysm due to Kawasaki disease: initial experience.

    Science.gov (United States)

    Peng, Yun; Zeng, Jinjin; Du, Zhongdong; Sun, Guoqiang; Guo, Huling

    2009-03-01

    To evaluate the initial application and value of 64-slice multidetector computed tomography as an alternative diagnostic modality in the follow-up of young children with coronary artery aneurysm due to Kawasaki disease. Twelve boys (mean age 5.1 years, range 1.8-7.8 years) for follow-up (time range from 1.1 to 5.1 years) of known Kawasaki disease and coronary artery aneurysm underwent 64-slice MDCT ECG-gated coronary angiography. All data were acquired without breath holding. Two pediatric radiologists independently assessed image quality and the diameter of all coronary segments were measured for each patient. The number, position, shape and size of each coronary artery aneurysm were observed and compared with those of ECHO performed previously. A total of 118/156 segments permitted visualization with diagnostic image quality, the CT measurements showed good inter-observer and intra-observer reliability, coefficients were 0.93 and 0.88, respectively. A total of 30 coronary artery aneurysms were identified with measured mean of 7.5+/-3.8 mm in diameter, and of 12.4+/-9.1 mm in longitudinal lengths.10 tumors were small, 8 tumors were medium and 12 tumors were giant aneurysm. The affected segments included LM7/12(58.3%), 9/12(75%) of LAD1, 4/12(33.3%) of LAD2, 2/12(16.7%) of LCX1; 6/12(50%) of RCA1, 9/12(75%) of RCA2 and 4/12(33.3%) of RCA3, including affected two segments in 9 tumors and three segments in 1 tumor. Calcifications were found in 5 aneurysms and 3/5 with thrombosis; six stenotic segments were found. ECHO failed to detect 8 tumors with 2/8 in LAD, 1/8 in LCX and 5/8 in RCA, and those included 4 small aneurysms. The use of 64-slice MDCT angiography proved valuable for monitoring young children with Kawasaki disease. However, further study is necessary to specify the sensitivity and specificity of MDCT in the follow-up.

  3. Usefulness of 64-slice MDCT for follow-up of young children with coronary artery aneurysm due to Kawasaki disease: Initial experience

    International Nuclear Information System (INIS)

    Peng Yun; Zeng Jinjin; Du Zhongdong; Sun Guoqiang; Guo Huling

    2009-01-01

    To evaluate the initial application and value of 64-slice multidetector computed tomography as an alternative diagnostic modality in the follow-up of young children with coronary artery aneurysm due to Kawasaki disease. Twelve boys (mean age 5.1 years, range 1.8-7.8 years) for follow-up (time range from 1.1 to 5.1 years) of known Kawasaki disease and coronary artery aneurysm underwent 64-slice MDCT ECG-gated coronary angiography. All data were acquired without breath holding. Two pediatric radiologists independently assessed image quality and the diameter of all coronary segments were measured for each patient. The number, position, shape and size of each coronary artery aneurysm were observed and compared with those of ECHO performed previously. A total of 118/156 segments permitted visualization with diagnostic image quality, the CT measurements showed good inter-observer and intra-observer reliability, coefficients were 0.93 and 0.88, respectively. A total of 30 coronary artery aneurysms were identified with measured mean of 7.5 ± 3.8 mm in diameter, and of 12.4 ± 9.1 mm in longitudinal lengths.10 tumors were small, 8 tumors were medium and 12 tumors were giant aneurysm. The affected segments included LM7/12(58.3%), 9/12(75%) of LAD1, 4/12(33.3%) of LAD2, 2/12(16.7%) of LCX1; 6/12(50%) of RCA1, 9/12(75%) of RCA2 and 4/12(33.3%) of RCA3, including affected two segments in 9 tumors and three segments in 1 tumor. Calcifications were found in 5 aneurysms and 3/5 with thrombosis; six stenotic segments were found. ECHO failed to detect 8 tumors with 2/8 in LAD, 1/8 in LCX and 5/8 in RCA, and those included 4 small aneurysms. The use of 64-slice MDCT angiography proved valuable for monitoring young children with Kawasaki disease. However, further study is necessary to specify the sensitivity and specificity of MDCT in the follow-up.

  4. Usefulness of 64-slice MDCT for follow-up of young children with coronary artery aneurysm due to Kawasaki disease: Initial experience

    Energy Technology Data Exchange (ETDEWEB)

    Peng Yun [Imaging Center, Beijing Children' s Hospital Affiliated to Capital Medical University, 56, Nanlishi Road, Xicheng District, Beijing 100045 (China)], E-mail: ppengyun@yahoo.com; Zeng Jinjin [Imaging Center, Beijing Children' s Hospital Affiliated to Capital Medical University, 56, Nanlishi Road, Xicheng District, Beijing 100045 (China); Du Zhongdong [Pediatric Cardiovascular Department, Beijing Children' s Hospital Affiliated to Capital Medical University, 56, Nanlishi Road, Xicheng District, Beijing 100045 (China); Sun Guoqiang [Imaging Center, Beijing Children' s Hospital Affiliated to Capital Medical University, 56, Nanlishi Road, Xicheng District, Beijing 100045 (China); Guo Huling [Pediatric Cardiovascular Department, Beijing Children' s Hospital Affiliated to Capital Medical University, 56, Nanlishi Road, Xicheng District, Beijing 100045 (China)

    2009-03-15

    To evaluate the initial application and value of 64-slice multidetector computed tomography as an alternative diagnostic modality in the follow-up of young children with coronary artery aneurysm due to Kawasaki disease. Twelve boys (mean age 5.1 years, range 1.8-7.8 years) for follow-up (time range from 1.1 to 5.1 years) of known Kawasaki disease and coronary artery aneurysm underwent 64-slice MDCT ECG-gated coronary angiography. All data were acquired without breath holding. Two pediatric radiologists independently assessed image quality and the diameter of all coronary segments were measured for each patient. The number, position, shape and size of each coronary artery aneurysm were observed and compared with those of ECHO performed previously. A total of 118/156 segments permitted visualization with diagnostic image quality, the CT measurements showed good inter-observer and intra-observer reliability, coefficients were 0.93 and 0.88, respectively. A total of 30 coronary artery aneurysms were identified with measured mean of 7.5 {+-} 3.8 mm in diameter, and of 12.4 {+-} 9.1 mm in longitudinal lengths.10 tumors were small, 8 tumors were medium and 12 tumors were giant aneurysm. The affected segments included LM7/12(58.3%), 9/12(75%) of LAD1, 4/12(33.3%) of LAD2, 2/12(16.7%) of LCX1; 6/12(50%) of RCA1, 9/12(75%) of RCA2 and 4/12(33.3%) of RCA3, including affected two segments in 9 tumors and three segments in 1 tumor. Calcifications were found in 5 aneurysms and 3/5 with thrombosis; six stenotic segments were found. ECHO failed to detect 8 tumors with 2/8 in LAD, 1/8 in LCX and 5/8 in RCA, and those included 4 small aneurysms. The use of 64-slice MDCT angiography proved valuable for monitoring young children with Kawasaki disease. However, further study is necessary to specify the sensitivity and specificity of MDCT in the follow-up.

  5. Enhancement pattern of small hepatocellular carcinoma (HCC) at contrast-enhanced US (CEUS), MDCT, and MRI: Intermodality agreement and comparison of diagnostic sensitivity between 2005 and 2010 American Association for the Study of Liver Diseases (AASLD) guidelines

    International Nuclear Information System (INIS)

    Furlan, Alessandro; Marin, Daniele; Cabassa, Paolo; Taibbi, Adele; Brunelli, Elena; Agnello, Francesco; Lagalla, Roberto; Brancatelli, Giuseppe

    2012-01-01

    Objective: To evaluate agreement between contrast-enhanced ultrasound (CEUS), multi-detector row computed tomography (MDCT) and magnetic resonance imaging (MRI) for the assessment of typical and atypical enhancement patterns of small hepatocellular carcinoma (HCC); and to compare diagnostic sensitivity of 2005 and 2010 American Association for the Study of Liver Diseases (AASLD) guidelines. Materials and methods: Between January 2008 and December 2009, we included cirrhotic patients with newly diagnosed 10–20 mm HCC imaged at two contrast-enhanced imaging techniques among CEUS, MDCT, and MRI. Dynamic studies were reviewed by two radiologists to assess enhancement pattern. Percentage of cases with concordant findings and Cohen coefficient (k) were calculated. McNemar's test was used to compare sensitivity between 2005 and 2010 AASLD guidelines. Results: There were 91 patients (69 M; 22 F; mean age, 68 years) with 96 HCCs, studied with a combination of CEUS and MDCT (n = 59), CEUS and MRI (n = 26), or MDCT and MRI (n = 11). Intermodality agreement for assessment of tumor enhancement pattern was 67% (k = 0.294, P = 0.001). Typical enhancement pattern was detected coincidentally at two imaging modalities in 50 (52%) HCCs. Sensitivity for the diagnosis of HCC increased significantly using the 2010 AASLD (81/96 (84%) vs. 50/96 (52%), P < 0.001). Conclusions: Agreement between two imaging modalities for the detection of typical tumor enhancement pattern was reached in 52% of cases. The 2010 AASLD guidelines significantly increased the sensitivity for the diagnosis of HCC

  6. Stress underestimation and mental health literacy of depression in Japanese workers: A cross-sectional study.

    Science.gov (United States)

    Nakamura-Taira, Nanako; Izawa, Shuhei; Yamada, Kosuke Chris

    2018-04-01

    Appropriately estimating stress levels in daily life is important for motivating people to undertake stress-management behaviors or seek out information on stress management and mental health. People who exhibit high stress underestimation might not be interested in information on mental health, and would therefore have less knowledge of it. We investigated the association between stress underestimation tendency and mental health literacy of depression (i.e., knowledge of the recognition, prognosis, and usefulness of resources of depression) in Japanese workers. We cross-sectionally surveyed 3718 Japanese workers using a web-based questionnaire on stress underestimation, mental health literacy of depression (vignettes on people with depression), and covariates (age, education, depressive symptoms, income, and worksite size). After adjusting for covariates, high stress underestimation was associated with greater odds of not recognizing depression (i.e., choosing anything other than depression). Furthermore, these individuals had greater odds of expecting the case to improve without treatment and not selecting useful sources of support (e.g. talk over with friends/family, see a psychiatrist, take medication, see a counselor) compared to those with moderate stress underestimation. These relationships were all stronger among males than among females. Stress underestimation was related to poorer mental health literacy of depression. Copyright © 2018 Elsevier B.V. All rights reserved.

  7. Parental and Child Factors Associated with Under-Estimation of Children with Excess Weight in Spain.

    Science.gov (United States)

    de Ruiter, Ingrid; Olmedo-Requena, Rocío; Jiménez-Moleón, José Juan

    2017-11-01

    Objective Understanding obesity misperception and associated factors can improve strategies to increase obesity identification and intervention. We investigate underestimation of child excess weight with a broader perspective, incorporating perceptions, views, and psychosocial aspects associated with obesity. Methods This study used cross-sectional data from the Spanish National Health Survey in 2011-2012 for children aged 2-14 years who are overweight or obese. Percentages of parental misperceived excess weight were calculated. Crude and adjusted analyses were performed for both child and parental factors analyzing associations with underestimation. Results Two-five year olds have the highest prevalence of misperceived overweight or obesity around 90%. In the 10-14 year old age group approximately 63% of overweight teens were misperceived as normal weight and 35.7 and 40% of obese males and females. Child gender did not affect underestimation, whereas a younger age did. Aspects of child social and mental health were associated with under-estimation, as was short sleep duration. Exercise, weekend TV and videogames, and food habits had no effect on underestimation. Fathers were more likely to misperceive their child´s weight status; however parent's age had no effect. Smokers and parents with excess weight were less likely to misperceive their child´s weight status. Parents being on a diet also decreased odds of underestimation. Conclusions for practice This study identifies some characteristics of both parents and children which are associated with under-estimation of child excess weight. These characteristics can be used for consideration in primary care, prevention strategies and for further research.

  8. Quantification of bronchial dimensions at MDCT using dedicated software

    International Nuclear Information System (INIS)

    Brillet, P.Y.; Fetita, C.I.; Saragaglia, A.; Perchet, D.; Preteux, F.; Beigelman-Aubry, C.; Grenier, P.A.

    2007-01-01

    This study aimed to assess the feasibility of quantification of bronchial dimensions at MDCT using dedicated software (BronCare). We evaluated the reliability of the software to segment the airways and defined criteria ensuring accurate measurements. BronCare was applied on two successive examinations in 10 mild asthmatic patients. Acquisitions were performed at pneumotachographically controlled lung volume (65% TLC), with reconstructions focused on the right lung base. Five validation criteria were imposed: (1) bronchus type: segmental and subsegmental; (2) lumen area (LA)>4 mm 2 ; (3) bronchus length (Lg) > 7 mm; (4) confidence index - giving the percentage of the bronchus not abutted by a vessel - (CI) >55% for validation of wall area (WA) and (5) a minimum of 10 contiguous cross-sectional images fulfilling the criteria. A complete segmentation procedure on both acquisitions made possible an evaluation of LA and WA in 174/223 (78%) and 171/174 (98%) of bronchi, respectively. The validation criteria were met for 56/69 (81%) and for 16/69 (23%) of segmental bronchi and for 73/102 (72%) and 58/102 (57%) of subsegmental bronchi, for LA and WA, respectively. In conclusion, BronCare is reliable to segment the airways in clinical practice. The proposed criteria seem appropriate to select bronchi candidates for measurement. (orig.)

  9. Intra-individual comparison of different contrast media concentrations (300 mg, 370 mg and 400 mg iodine) in MDCT

    Energy Technology Data Exchange (ETDEWEB)

    Behrendt, Florian F.; Keil, Sebastian; Plumhans, Cedric; Guenther, Rolf W. [RWTH Aachen University, Department of Diagnostic Radiology, University Hospital, Aachen (Germany); Pietsch, Hubertus; Jost, Gregor; Sieber, Martin A.; Seidensticker, Peter [Bayer Schering Pharma AG, Berlin (Germany); Mahnken, Andreas H. [RWTH Aachen University, Department of Diagnostic Radiology, University Hospital, Aachen (Germany); RWTH Aachen University, Applied Medical Engineering, Helmholtz-Institute for Biomedical Engineering, Aachen (Germany)

    2010-07-15

    To compare intra-individual contrast enhancement in multi-detector-row computed tomography (MDCT) using contrast media (CM) containing 300, 370 and 400 mg iodine per ml (mgI/ml). Six pigs underwent repeated chest MDCT using three different CM (iopromide 300, iopromide 370, iomeprol 400). An identical iodine delivery (IDR) rate of 1.5 gI/s and a constant total iodine dose of 300 mg/kg body weight were used. Dynamic CT were acquired at the level of the pulmonary artery, and the ascending and descending aorta. After the time enhancement curves were computed, the pulmonary and aortic peak enhancement, time to peak and plateau time above 300 HU were calculated. Intra-individual peak contrast enhancement was significantly higher for the 300 mgI/ml contrast medium compared with the 370 and 400 mgI/ml media: pulmonary trunk 595 HU vs 516 HU (p = 0.0093) vs 472HU (p = 0.0005), and aorta 505 HU vs 454 HU (p = 0.0008) vs 439 HU (p = 0.0001), respectively. Comparison of time to peaks showed no significant difference. Plateau times were significantly longer for the 300 mgI/ml than for the 370 and 400 mgI/ml CM at all anatomical sites. Given normalised IDR and total iodine burden, the use of CM with a standard concentration with 300 mg iodine/ml provides improved contrast enhancement compared with highly concentrated CM in the chest. (orig.)

  10. Tick-borne encephalitis (TBE): an underestimated risk…still: report of the 14th annual meeting of the International Scientific Working Group on Tick-Borne Encephalitis (ISW-TBE).

    Science.gov (United States)

    Kunze, Ursula

    2012-06-01

    Today, the risk of getting tick-borne encephalitis (TBE) is still underestimated in many parts of Europe and worldwide. Therefore, the 14th meeting of the International Scientific Working Group on Tick-Borne Encephalitis (ISW-TBE) - a group of neurologists, general practitioners, clinicians, travel physicians, virologists, pediatricians, and epidemiologists - was held under the title "Tick-borne encephalitis: an underestimated risk…still". Among the discussed issues were: TBE, an underestimated risk in children, a case report in two Dutch travelers, the very emotional report of a tick victim, an overview of the epidemiological situation, investigations to detect new TBE cases in Italy, TBE virus (TBEV) strains circulation in Northern Europe, TBE Program of the European Centre for Disease Prevention and Control (ECDC), efforts to increase the TBE vaccination rate in the Czech Republic, positioning statement of the World Health Organization (WHO), and TBE in dogs. To answer the question raised above: Yes, the risk of getting TBE is underestimated in children and adults, because awareness is still too low. It is still underestimated in several areas of Europe, where, for a lack of human cases, TBEV is thought to be absent. It is underestimated in travelers, because they still do not know enough about the risk, and diagnostic awareness in non-endemic countries is still low. Copyright © 2012. Published by Elsevier GmbH. All rights reserved.

  11. Underestimation of Severity of Previous Whiplash Injuries

    Science.gov (United States)

    Naqui, SZH; Lovell, SJ; Lovell, ME

    2008-01-01

    INTRODUCTION We noted a report that more significant symptoms may be expressed after second whiplash injuries by a suggested cumulative effect, including degeneration. We wondered if patients were underestimating the severity of their earlier injury. PATIENTS AND METHODS We studied recent medicolegal reports, to assess subjects with a second whiplash injury. They had been asked whether their earlier injury was worse, the same or lesser in severity. RESULTS From the study cohort, 101 patients (87%) felt that they had fully recovered from their first injury and 15 (13%) had not. Seventy-six subjects considered their first injury of lesser severity, 24 worse and 16 the same. Of the 24 that felt the violence of their first accident was worse, only 8 had worse symptoms, and 16 felt their symptoms were mainly the same or less than their symptoms from their second injury. Statistical analysis of the data revealed that the proportion of those claiming a difference who said the previous injury was lesser was 76% (95% CI 66–84%). The observed proportion with a lesser injury was considerably higher than the 50% anticipated. CONCLUSIONS We feel that subjects may underestimate the severity of an earlier injury and associated symptoms. Reasons for this may include secondary gain rather than any proposed cumulative effect. PMID:18201501

  12. Ileocaecal Intussusception with a Lead Point: Unusual MDCT Findings of Active Crohn’s Disease Involving the Appendix

    Directory of Open Access Journals (Sweden)

    Ebru Ozan

    2015-01-01

    Full Text Available Adult intussusception is a rare entity accounting for 1% of all bowel obstructions. Unlike intussusceptions in children, which are idiopathic in 90% of cases, adult intussusceptions have an identifiable cause (lead point in the majority of cases. Crohn’s disease (CD may affect any part of the gastrointestinal tract, including the appendix. It was shown to be a predisposing factor for intussusception. Here, we report a rare case of adult intussusception with a lead point, emphasizing diagnostic input of multidetector computed tomography (MDCT in a patient with active CD that involves the appendix.

  13. Individuals underestimate moderate and vigorous intensity physical activity.

    Directory of Open Access Journals (Sweden)

    Karissa L Canning

    Full Text Available BACKGROUND: It is unclear whether the common physical activity (PA intensity descriptors used in PA guidelines worldwide align with the associated percent heart rate maximum method used for prescribing relative PA intensities consistently between sexes, ethnicities, age categories and across body mass index (BMI classifications. OBJECTIVES: The objectives of this study were to determine whether individuals properly select light, moderate and vigorous intensity PA using the intensity descriptions in PA guidelines and determine if there are differences in estimation across sex, ethnicity, age and BMI classifications. METHODS: 129 adults were instructed to walk/jog at a "light," "moderate" and "vigorous effort" in a randomized order. The PA intensities were categorized as being below, at or above the following %HRmax ranges of: 50-63% for light, 64-76% for moderate and 77-93% for vigorous effort. RESULTS: On average, people correctly estimated light effort as 51.5±8.3%HRmax but underestimated moderate effort as 58.7±10.7%HRmax and vigorous effort as 69.9±11.9%HRmax. Participants walked at a light intensity (57.4±10.5%HRmax when asked to walk at a pace that provided health benefits, wherein 52% of participants walked at a light effort pace, 19% walked at a moderate effort and 5% walked at a vigorous effort pace. These results did not differ by sex, ethnicity or BMI class. However, younger adults underestimated moderate and vigorous intensity more so than middle-aged adults (P<0.05. CONCLUSION: When the common PA guideline descriptors were aligned with the associated %HRmax ranges, the majority of participants underestimated the intensity of PA that is needed to obtain health benefits. Thus, new subjective descriptions for moderate and vigorous intensity may be warranted to aid individuals in correctly interpreting PA intensities.

  14. Value of MDCT and Clinical and Laboratory Data for Predicting the Need for Surgical Intervention in Suspected Small-Bowel Obstruction.

    Science.gov (United States)

    Scrima, Andrew; Lubner, Meghan G; King, Scott; Pankratz, Joshua; Kennedy, Gregory; Pickhardt, Perry J

    2017-04-01

    The purpose of this article is to assess the value of a large panel of clinical and MDCT variables in patients with suspected small-bowel obstruction (SBO) for predicting urgent surgical intervention (data were abstracted from electronic medical record review. Univariate and multivariate analyses were performed. Among all 179 patients with suspected SBO, 56 (31.3%) underwent surgical intervention within 72 hours, 10 (5.6%) had ischemia at surgery, and nine (5.0%) required small-bowel resection. On univariate analysis, multiple CT findings were highly significant (p < 0.01) for predicting the main surgical outcomes, including degree of obstruction, 5-point radiology likelihood scores, and the presence of a transition point, closed loop, and mesenteric congestion. None of the objective clinical or laboratory variables (including serum lactate level) reached this level of significance. At multivariate analysis, forward stepwise logistic regression with 0.05 significance level cutoff included both degree of obstruction (p < 0.001) and closed loop (p < 0.01), with the presence of a transition point showing a trend toward significance (p = 0.081). A number of findings at abdominal MDCT are associated with the need for surgery and other important surgical outcomes in patients with suspected SBO. Overall radiologist impression of need for surgical intervention was a better predictor than any clinical or laboratory parameter.

  15. Stress Underestimation and Mental Health Outcomes in Male Japanese Workers: a 1-Year Prospective Study.

    Science.gov (United States)

    Izawa, Shuhei; Nakamura-Taira, Nanako; Yamada, Kosuke Chris

    2016-12-01

    Being appropriately aware of the extent of stress experienced in daily life is essential in motivating stress management behaviours. Excessive stress underestimation obstructs this process, which is expected to exert adverse effects on health. We prospectively examined associations between stress underestimation and mental health outcomes in Japanese workers. Web-based surveys were conducted twice with an interval of 1 year on 2359 Japanese male workers. Participants were asked to complete survey items concerning stress underestimation, depressive symptoms, sickness absence, and antidepressant use. Multiple logistic regression analysis revealed that high baseline levels of 'overgeneralization of stress' and 'insensitivity to stress' were significantly associated with new-onset depressive symptoms (OR = 2.66 [95 % CI, 1.54-4.59], p stress underestimation, including stress insensitivity and the overgeneralization of stress, could exert adverse effects on mental health.

  16. Poverty Underestimation in Rural India- A Critique

    OpenAIRE

    Sivakumar, Marimuthu; Sarvalingam, A

    2010-01-01

    When ever the Planning Commission of India releases the poverty data, that data is being criticised by experts and economists. The main criticism is underestimation of poverty especially in rural India by the Planning Commission. This paper focuses on that criticism and compares the Indian Planning Commission’s 2004-05 rural poverty data with the India’s 2400 kcal poverty norms, World Bank’s US $1.08 poverty concept and Asian Development Bank’s US $1.35 poverty concept.

  17. Accuracy of contrast-enhanced dual-energy MDCT for the assessment of iodine uptake in renal lesions.

    Science.gov (United States)

    Mileto, Achille; Marin, Daniele; Ramirez-Giraldo, Juan Carlos; Scribano, Emanuele; Krauss, Bernhard; Mazziotti, Silvio; Ascenti, Giorgio

    2014-05-01

    The objective of our study was to assess the accuracy of iodine-related attenuation and iodine quantification as imaging biomarkers of iodine uptake in renal lesions on a single-phase nephrographic image with dual-energy MDCT. Fifty-nine patients (41 men, 18 women; age range, 28-84 years) with 80 renal lesions underwent contrast-enhanced dual-energy CT during the nephrographic phase of enhancement. Renal lesions were characterized as enhancing or nonenhancing on color-coded iodine overlay maps using iodine-related attenuation (in Hounsfield units) and iodine quantification (in milligrams per milliliter). For iodine-related attenuation the iodine uptake thresholds of 15 and 20 HU were tested; a threshold of 0.5 mg/mL was used for iodine quantification. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of iodine-related attenuation and iodine quantification were calculated from chi-square tests of contingency with histopathology or imaging follow-up as the reference standard. The 95% CIs were calculated from binomial expression. Differences in sensitivity and specificity were assessed by means of McNemar analysis. A significant difference in sensitivity and specificity was found between iodine-related attenuation with the thresholds of 15 HU (sensitivity, 91.4%; specificity, 93.3%; PPV, 91.4%; NPV, 93.3%) and 20 HU (sensitivity, 77.1%; specificity, 100%; PPV, 100%; NPV, 84.9%) (p = 0.008) and between iodine quantification (sensitivity, 100%; specificity, 97.7%; PPV, 97.2%; NPV, 100%) and iodine-related attenuation with a threshold of 20 HU (p = 0.004). No significant difference in sensitivity and specificity was found between iodine quantification and iodine-related attenuation with a threshold of 15 HU. Contrast-enhanced dual-energy MDCT with iodine-related attenuation and iodine quantification allows accurate evaluation of iodine uptake in renal lesions on a single-phase nephrographic image.

  18. MDCT quantification is the dominant parameter in decision–making regarding chest tube drainage for stable patients with traumatic pneumothorax

    Science.gov (United States)

    Cai, Wenli; Lee, June-Goo; Fikry, Karim; Yoshida, Hiroyuki; Novelline, Robert; de Moya, Marc

    2013-01-01

    It is commonly believed that the size of a pneumothorax is an important determinant of treatment decision, in particular regarding whether chest tube drainage (CTD) is required. However, the volumetric quantification of pneumothoraces has not routinely been performed in clinics. In this paper, we introduced an automated computer-aided volumetry (CAV) scheme for quantification of volume of pneumothoraces in chest multi-detect CT (MDCT) images. Moreover, we investigated the impact of accurate volume of pneumothoraces in the improvement of the performance in decision-making regarding CTD in the management of traumatic pneumothoraces. For this purpose, an occurrence frequency map was calculated for quantitative analysis of the importance of each clinical parameter in the decision-making regarding CTD by a computer simulation of decision-making using a genetic algorithm (GA) and a support vector machine (SVM). A total of 14 clinical parameters, including volume of pneumothorax calculated by our CAV scheme, was collected as parameters available for decision-making. The results showed that volume was the dominant parameter in decision-making regarding CTD, with an occurrence frequency value of 1.00. The results also indicated that the inclusion of volume provided the best performance that was statistically significant compared to the other tests in which volume was excluded from the clinical parameters. This study provides the scientific evidence for the application of CAV scheme in MDCT volumetric quantification of pneumothoraces in the management of clinically stable chest trauma patients with traumatic pneumothorax. PMID:22560899

  19. Estimating Effective Dose of Radiation From Pediatric Cardiac CT Angiography Using a 64-MDCT Scanner: New Conversion Factors Relating Dose-Length Product to Effective Dose.

    Science.gov (United States)

    Trattner, Sigal; Chelliah, Anjali; Prinsen, Peter; Ruzal-Shapiro, Carrie B; Xu, Yanping; Jambawalikar, Sachin; Amurao, Maxwell; Einstein, Andrew J

    2017-03-01

    The purpose of this study is to determine the conversion factors that enable accurate estimation of the effective dose (ED) used for cardiac 64-MDCT angiography performed for children. Anthropomorphic phantoms representative of 1- and 10-year-old children, with 50 metal oxide semiconductor field-effect transistor dosimeters placed in organs, underwent scanning performed using a 64-MDCT scanner with different routine clinical cardiac scan modes and x-ray tube potentials. Organ doses were used to calculate the ED on the basis of weighting factors published in 1991 in International Commission on Radiological Protection (ICRP) publication 60 and in 2007 in ICRP publication 103. The EDs and the scanner-reported dose-length products were used to determine conversion factors for each scan mode. The effect of infant heart rate on the ED and the conversion factors was also assessed. The mean conversion factors calculated using the current definition of ED that appeared in ICRP publication 103 were as follows: 0.099 mSv · mGy -1 · cm -1 , for the 1-year-old phantom, and 0.049 mSv · mGy -1 · cm -1 , for the 10-year-old phantom. These conversion factors were a mean of 37% higher than the corresponding conversion factors calculated using the older definition of ED that appeared in ICRP publication 60. Varying the heart rate did not influence the ED or the conversion factors. Conversion factors determined using the definition of ED in ICRP publication 103 and cardiac, rather than chest, scan coverage suggest that the radiation doses that children receive from cardiac CT performed using a contemporary 64-MDCT scanner are higher than the radiation doses previously reported when older chest conversion factors were used. Additional up-to-date pediatric cardiac CT conversion factors are required for use with other contemporary CT scanners and patients of different age ranges.

  20. A systematic approach towards the objective evaluation of low-contrast performance in MDCT: Combination of a full-reference image fidelity metric and a software phantom

    International Nuclear Information System (INIS)

    Falck, Christian von; Rodt, Thomas; Waldeck, Stephan; Hartung, Dagmar; Meyer, Bernhard; Wacker, Frank; Shin, Hoen-oh

    2012-01-01

    Objectives: To assess the feasibility of an objective approach for the evaluation of low-contrast detectability in multidetector computed-tomography (MDCT) by combining a virtual phantom containing simulated lesions with an image quality metric. Materials and methods: A low-contrast phantom containing hypodense spheric lesions (−20 HU) was scanned on a 64-slice MDCT scanner at 4 different dose levels (25, 50, 100, 200 mAs). In addition, virtual round hypodense low-contrast lesions (20 HU object contrast) based on real CT data were inserted into the lesion-free section of the datasets. The sliding-thin-slab algorithm was applied to the image data with an increasing slice-thickness from 1 to 15 slices. For each dataset containing simulated lesions a lesion-free counterpart was reconstructed and post-processed in the same manner. The low-contrast performance of all datasets containing virtual lesions was determined using a full-reference image quality metric (modified multiscale structural similarity index, MS-SSIM*). The results were validated against a reader-study of the real lesions. Results: For all dose levels and lesion sizes there was no statistically significant difference between the low-contrast performance as determined by the image quality metric when compared to the reader study (p < 0.05). The intraclass correlation coefficient was 0.72, 0.82, 0.90 and 0.84 for lesion diameters of 4 mm, 5 mm, 8 mm and 10 mm, respectively. The use of the sliding-thin-slab algorithm improves lesion detectability by a factor ranging from 1.15 to 2.69 when compared with the original axial slice (0.625 mm). Conclusion: The combination of a virtual phantom and a full-reference image quality metric enables a systematic, automated and objective evaluation of low-contrast detectability in MDCT datasets and correlates well with the judgment of human readers.

  1. 3D noise power spectrum applied on clinical MDCT scanners: effects of reconstruction algorithms and reconstruction filters

    Science.gov (United States)

    Miéville, Frédéric A.; Bolard, Gregory; Benkreira, Mohamed; Ayestaran, Paul; Gudinchet, François; Bochud, François; Verdun, Francis R.

    2011-03-01

    The noise power spectrum (NPS) is the reference metric for understanding the noise content in computed tomography (CT) images. To evaluate the noise properties of clinical multidetector (MDCT) scanners, local 2D and 3D NPSs were computed for different acquisition reconstruction parameters. A 64- and a 128-MDCT scanners were employed. Measurements were performed on a water phantom in axial and helical acquisition modes. CT dose index was identical for both installations. Influence of parameters such as the pitch, the reconstruction filter (soft, standard and bone) and the reconstruction algorithm (filtered-back projection (FBP), adaptive statistical iterative reconstruction (ASIR)) were investigated. Images were also reconstructed in the coronal plane using a reformat process. Then 2D and 3D NPS methods were computed. In axial acquisition mode, the 2D axial NPS showed an important magnitude variation as a function of the z-direction when measured at the phantom center. In helical mode, a directional dependency with lobular shape was observed while the magnitude of the NPS was kept constant. Important effects of the reconstruction filter, pitch and reconstruction algorithm were observed on 3D NPS results for both MDCTs. With ASIR, a reduction of the NPS magnitude and a shift of the NPS peak to the low frequency range were visible. 2D coronal NPS obtained from the reformat images was impacted by the interpolation when compared to 2D coronal NPS obtained from 3D measurements. The noise properties of volume measured in last generation MDCTs was studied using local 3D NPS metric. However, impact of the non-stationarity noise effect may need further investigations.

  2. Social cure, what social cure? The propensity to underestimate the importance of social factors for health.

    Science.gov (United States)

    Haslam, S Alexander; McMahon, Charlotte; Cruwys, Tegan; Haslam, Catherine; Jetten, Jolanda; Steffens, Niklas K

    2018-02-01

    Recent meta-analytic research indicates that social support and social integration are highly protective against mortality, and that their importance is comparable to, or exceeds, that of many established behavioural risks such as smoking, high alcohol consumption, lack of exercise, and obesity that are the traditional focus of medical research (Holt-Lunstad et al., 2010). The present study examines perceptions of the contribution of these various factors to life expectancy within the community at large. American and British community respondents (N = 502) completed an on-line survey assessing the perceived importance of social and behavioural risk factors for mortality. As hypothesized, while respondents' perceptions of the importance of established behavioural risks was positively and highly correlated with their actual importance, social factors were seen to be far less important for health than they actually are. As a result, overall, there was a small but significant negative correlation between the perceived benefits and the actual benefits of different social and behavioural factors. Men, younger participants, and participants with a lower level of education were more likely to underestimate the importance of social factors for health. There was also evidence that underestimation was predicted by a cluster of ideological factors, the most significant of which was respondents' respect for prevailing convention and authorities as captured by Right-Wing Authoritarianism. Findings suggest that while people generally underestimate the importance of social factors for health this also varies as a function of demographic and ideological factors. They point to a range of challenges confronting those who seek to promote greater awareness of the importance of social factors for health. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. BMI may underestimate the socioeconomic gradient in true obesity

    NARCIS (Netherlands)

    van den Berg, G.; van Eijsden, M.; Vrijkotte, T. G. M.; Gemke, R. J. B. J.

    2013-01-01

    Body mass index (BMI) does not make a distinction between fat mass and lean mass. In children, high fat mass appears to be associated with low maternal education, as well as low lean mass because maternal education is associated with physical activity. Therefore, BMI might underestimate true obesity

  4. Anatomical variations in the origins of the celiac axis and the superior mesenteric artery: MDCT angiographic findings and their probable embryological mechanisms

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Yi; Cheng, Cheng; Wang, Lu; Li, Ran; Chen, Jin-hua; Gong, Shui-gen [Institute of Surgery Research, Daping Hospital, Third Military Medical University, Department of Radiology, Chongqing (China)

    2014-08-15

    To identify the spectrum and prevalence of anatomical variations in the origin of the celiac axis (CA), the superior mesenteric artery (SMA) and their major branches by using multidetector computed tomographic (MDCT) angiography. A retrospective evaluation was carried out on 1,500 abdominal MDCT angiography images. The aortic origins of the CA, the SMA and their major branch patterns were investigated. Normal aortic origins of CA and SMA were noted in 1,347 (89.8 %) patients. Seven types of CA and SMA origin variants were identified in 153 (10.2 %) patients. The three most common variations were hepatomesenteric trunk (67 patients, 4.47 %), celiomesenteric trunk (CMT) (51 patients, 3.4 %) and splenomesenteric trunk (18 patients, 1.2 %). An evaluation of CMT was classified as long (34 patients, 66.7 %) or short (17 patients, 33.3 %) subtypes, compared with the length of the common trunk. Further CMT classification was based on the origin of the left gastric artery: subtype I, 26 patients (53.1 %); subtype II, 5 patients (10.2 %); subtype III, 15 patients (30.6 %); subtype IV, 3 patients (6.1 %). Dislocation interruption, incomplete interruption and persistence of the longitudinal anastomosis could be the embryological mechanisms of the variant origins of the CA, the SMA and their major branches. (orig.)

  5. Anatomical variations in the origins of the celiac axis and the superior mesenteric artery: MDCT angiographic findings and their probable embryological mechanisms

    International Nuclear Information System (INIS)

    Wang, Yi; Cheng, Cheng; Wang, Lu; Li, Ran; Chen, Jin-hua; Gong, Shui-gen

    2014-01-01

    To identify the spectrum and prevalence of anatomical variations in the origin of the celiac axis (CA), the superior mesenteric artery (SMA) and their major branches by using multidetector computed tomographic (MDCT) angiography. A retrospective evaluation was carried out on 1,500 abdominal MDCT angiography images. The aortic origins of the CA, the SMA and their major branch patterns were investigated. Normal aortic origins of CA and SMA were noted in 1,347 (89.8 %) patients. Seven types of CA and SMA origin variants were identified in 153 (10.2 %) patients. The three most common variations were hepatomesenteric trunk (67 patients, 4.47 %), celiomesenteric trunk (CMT) (51 patients, 3.4 %) and splenomesenteric trunk (18 patients, 1.2 %). An evaluation of CMT was classified as long (34 patients, 66.7 %) or short (17 patients, 33.3 %) subtypes, compared with the length of the common trunk. Further CMT classification was based on the origin of the left gastric artery: subtype I, 26 patients (53.1 %); subtype II, 5 patients (10.2 %); subtype III, 15 patients (30.6 %); subtype IV, 3 patients (6.1 %). Dislocation interruption, incomplete interruption and persistence of the longitudinal anastomosis could be the embryological mechanisms of the variant origins of the CA, the SMA and their major branches. (orig.)

  6. Step-and-shoot prospectively ECG-gated vs. retrospectively ECG-gated with tube current modulation coronary CT angiography using 128-slice MDCT patients with chest pain: diagnostic performance and radiation dose

    International Nuclear Information System (INIS)

    Kim, Jeong Su; Choo, Ki Seok; Jeong, Dong Wook

    2011-01-01

    Background With increasing awareness for radiation exposure, the study of diagnostic accuracy of coronary CT angiography (CCTA) with low radiation dose techniques is mandatory to both radiologist and clinician. Purpose To compare diagnostic performance and effective radiation dose between step-and-shoot prospectively ECG-gated and retrospectively ECG-gated with tube current modulation (TCM) CCTA using 128-slice multidetector computed tomography (MDCT). Material and Methods We retrospectively evaluated 60 patients who underwent CCTA with either of two different low-dose techniques using 128-slice MDCT (23 patients for step-and shoot-prospectively ECG-gated and 37 patients for retrospectively ECG-gated with TCM CCTA) followed by conventional coronary angiography. All coronary arteries and all segments thereof, except anatomical variants or small size (< 1.5 mm) ones, were included in analysis. Results In per-segment analysis, sensitivity, specificity, positive predictive value, and negative predictive value were 91/96%, 95/94%, 75/73%, and 98/99% for step-and-shoot prospectively ECG-gated and retrospectively ECG gated with TCM CCTA, respectively, relative to conventional coronary angiography. Effective radiation dose were 1.75 ± 0.83 mSv, 4.91 ± 1.71 mSv in the step-and-shoot prospectively ECG-gated and retrospectively ECG-gated with TCM CCTA groups, respectively. Conclusion The two low-radiation dose CCTA techniques using 128-slice MDCT yields comparable diagnostic performance for coronary artery disease in symptomatic patients with low heart rates

  7. Using the MDCT thick slab MinIP method for the follow-up of pulmonary emphysema.

    Science.gov (United States)

    Lan, Hai; Nishitani, Hiromu; Nishihara, Sadamitsu; Ueno, Junji; Takao, Shoichiro; Iwamoto, Seiji; Kawanaka, Takashi; Mahmut, Mawlan; Qingge, Si

    2011-08-01

    The purpose of this study was to evaluate the usefulness of thick slab minimum intensity projection (MinIP) as a follow-up method in patients with pulmonary emphysema. This method was used to determine the presence or absence of changes over time in the lung field based on multi-detector-row CT (MDCT) data. Among patients diagnosed with pulmonary emphysema who underwent 16-MDCT (slice thickness, 1 mm) twice at an interval of 6 months or more, 12 patients without changes in the lung field and 14 with clear changes in the lung field were selected as subjects. An image interpretation experiment was performed by five image interpreters. Pulmonary emphysema was followed up using two types of thick slab MinIP (thick slab MinIP 1 and 2) and multi-planar reformation (MPR), and the results of image interpretation were evaluated by receiver operating characteristic (ROC) analysis. In addition, the time required for image interpretation was compared among the three follow-up methods. The area under the ROC curve (Az) was 0.794 for thick slab MinIP 1, 0.778 for the thick slab MinIP 2, and 0.759 for MPR, showing no significant differences among the three methods. Individual differences in each item were significantly more marked for MPR than for thick slab MinIP. The time required for image interpretation was around 18 seconds for thick slab MinIP 1, 11 seconds for thick slab MinIP 2, and approximately 127 seconds for MPR, showing significant differences among the three methods. There were no significant differences in the results of image interpretation regarding the presence or absence of changes in the lung fields between thick slab MinIP and MPR. However, thick slab MinIP showed a shorter image interpretation time and smaller individual differences in the results among image interpreters than MPR, suggesting the usefulness of this method for determining the presence or absence of changes with time in the lung fields of patients with pulmonary emphysema.

  8. Underestimated effect sizes in GWAS: fundamental limitations of single SNP analysis for dichotomous phenotypes.

    Directory of Open Access Journals (Sweden)

    Sven Stringer

    Full Text Available Complex diseases are often highly heritable. However, for many complex traits only a small proportion of the heritability can be explained by observed genetic variants in traditional genome-wide association (GWA studies. Moreover, for some of those traits few significant SNPs have been identified. Single SNP association methods test for association at a single SNP, ignoring the effect of other SNPs. We show using a simple multi-locus odds model of complex disease that moderate to large effect sizes of causal variants may be estimated as relatively small effect sizes in single SNP association testing. This underestimation effect is most severe for diseases influenced by numerous risk variants. We relate the underestimation effect to the concept of non-collapsibility found in the statistics literature. As described, continuous phenotypes generated with linear genetic models are not affected by this underestimation effect. Since many GWA studies apply single SNP analysis to dichotomous phenotypes, previously reported results potentially underestimate true effect sizes, thereby impeding identification of true effect SNPs. Therefore, when a multi-locus model of disease risk is assumed, a multi SNP analysis may be more appropriate.

  9. MDCT quantification is the dominant parameter in decision-making regarding chest tube drainage for stable patients with traumatic pneumothorax.

    Science.gov (United States)

    Cai, Wenli; Lee, June-Goo; Fikry, Karim; Yoshida, Hiroyuki; Novelline, Robert; de Moya, Marc

    2012-07-01

    It is commonly believed that the size of a pneumothorax is an important determinant of treatment decision, in particular regarding whether chest tube drainage (CTD) is required. However, the volumetric quantification of pneumothoraces has not routinely been performed in clinics. In this paper, we introduced an automated computer-aided volumetry (CAV) scheme for quantification of volume of pneumothoraces in chest multi-detect CT (MDCT) images. Moreover, we investigated the impact of accurate volume of pneumothoraces in the improvement of the performance in decision-making regarding CTD in the management of traumatic pneumothoraces. For this purpose, an occurrence frequency map was calculated for quantitative analysis of the importance of each clinical parameter in the decision-making regarding CTD by a computer simulation of decision-making using a genetic algorithm (GA) and a support vector machine (SVM). A total of 14 clinical parameters, including volume of pneumothorax calculated by our CAV scheme, was collected as parameters available for decision-making. The results showed that volume was the dominant parameter in decision-making regarding CTD, with an occurrence frequency value of 1.00. The results also indicated that the inclusion of volume provided the best performance that was statistically significant compared to the other tests in which volume was excluded from the clinical parameters. This study provides the scientific evidence for the application of CAV scheme in MDCT volumetric quantification of pneumothoraces in the management of clinically stable chest trauma patients with traumatic pneumothorax. Copyright © 2012 Elsevier Ltd. All rights reserved.

  10. Survey of pediatric MDCT radiation dose from university hospitals in Thailand. A preliminary for national dose survey

    Energy Technology Data Exchange (ETDEWEB)

    Kritsaneepaiboon, Supika [Dept. of Radiology, Faculty of Medicine, Prince of Songkla Univ., Hat Yai (Thailand)], e-mail: supikak@yahoo.com; Trinavarat, Panruethai [Dept. of Radiology, Faculty of Medicine, Chulalongkorn Univ., Bangkok (Thailand); Visrutaratna, Pannee [Dept. of Radiology, Faculty of Medicine, Chiang Mai Univ., Chiang Mai (Thailand)

    2012-09-15

    Background: Increasing pediatric CT usage worldwide needs the optimization of CT protocol examination. Although there are previous published dose reference level (DRL) values, the local DRLs should be established to guide for clinical practice and monitor the CT radiation. Purpose: To determine the multidetector CT (MDCT) radiation dose in children in three university hospitals in Thailand in four age groups using the CT dose index (CTDI) and dose length product (DLP). Material and Methods: A retrospective review of CT dosimetry in pediatric patients (<15 years of age) who had undergone head, chest, and abdominal MDCT in three major university hospitals in Thailand was performed. Volume CTDI (CTDIvol) and DLP were recorded, categorized into four age groups: <1 year, 1- < 5 years, 5- <10 years, and 10- <15 years in each scanner. Range, mean, and third quartile values were compared with the national reference dose levels for CT in pediatric patients from the UK and Switzerland according to International Commission on Radiological Protection (ICRP) recommendation. Results: Per age group, the third quartile values for brain, chest, and abdominal CTs were, respectively, in terms of CTDIvol: 25, 30, 40, and 45 mGy; 4.5, 5.7, 10, and 15.6 mGy; 8.5, 9, 14, and 17 mGy; and in terms of DLP: 400, 570, 610, and 800 mGy cm; 80, 140, 305, and 470 mGy cm; and 190, 275, 560,765 mGy cm. Conclusion: This preliminary national dose survey for pediatric CT in Thailand found that the majority of CTDIvol and DLP values in brain, chest, and abdominal CTs were still below the diagnostic reference levels (DRLs) from the UK and Switzerland regarding to ICRP recommendation.

  11. Frequency and types of fractures in maxillofacial traumas. Assessment using MDCT with multiplanar and 3D reconstructions

    International Nuclear Information System (INIS)

    Tomich, G.; Baigorria, P.; Orlando, N.; Mejico, M.; Costamagna, C.; Villavicencio, R.

    2011-01-01

    Introduction: Maxillofacial trauma (MFT) is a common reason for attendance at Emergency Departments. The complex anatomy of the facial bones requires multiplanar imaging techniques for a proper evaluation. Objectives. To describe frequency and types of fractures in a series of patients with MFT evaluated by multi-slice computed tomography (MDCT) with multiplanar and 3D reconstructions. Materials and Methods: Facial bone CTs ordered for MFT by the Emergency Department from June 2008 to December 2009 were retrospectively reviewed. The following data were obtained: age, gender, cause of trauma, presence and type of fractures. Patients were evaluated with an 8-channel MDCT. Multiplanar reconstructions were performed in all cases using high resolution bone window and soft tissue window, as well as 3D reconstructions. Results: One-hundred and thirty-seven CTs were performed for MFT: 78 (57%) showed 131 fractures. Of these 78 patients, 52 (66%) were males and 26 (34%) were females; mean age 33 years old (range: 14-90 yrs.). Causes: 58 % were injuries from traffic accidents; 24% were injuries from fights; 13% were sport injuries; and 7% were due to miscellaneous etiologies. Type and frequency of fractures: 18.3% were orbital floor fractures, 16% were maxillary sinus fractures, 15.3% were nasal fractures, 13% were jaw fractures, 9.2% were orbital fractures, and 12.3% were fractures of the zygomatic-malar complex; two cases of Le Fort II-III fractures were also observed. Conclusions: Fractures were more common in males, in the age range from 15 to 35 years old. Most fractures, and the most complex ones, were caused by traffic accidents. The most common fracture, either isolated or associated with other fractures, was the orbital floor fracture. (authors)

  12. Injuries of the scapholunate and lunotriquetral ligaments as well as the TFCC in intra-articular distal radius fractures. Prevalence assessed with MDCT arthrography

    Energy Technology Data Exchange (ETDEWEB)

    Klempka, A.; Wagner, M.; Fodor, S.; Schmitt, R. [Cardiovascular Center Bad Neustadt an der Saale, Department of Diagnostic and Interventional Radiology, Bad Neustadt an der Saale (Germany); Prommersberger, K.J. [Clinic for Hand Surgery, Bad Neustadt an der Saale (Germany); Uder, M. [Friedrich-Alexander-University Erlangen-Nuernberg (FAU), Department of Diagnostic Radiology, Erlangen (Germany)

    2016-03-15

    To evaluate the prevalence of injuries of the scapholunate and lunotriquetral interosseous ligaments (SLIL, LTIL) as well as the triangular fibrocartilage complex (TFCC) in intra-articular distal radius fractures (iaDRF). Two hundred and thirty-three patients with acute iaDRF underwent MDCT arthrography. The SLIL and LTIL were described as normal, partially or completely ruptured. Major injuries of the SLIL were defined as completely ruptured dorsal segments, those of the LTIL as completely ruptured palmar segments. The TFCC was judged as normal or injured. Interobserver variability was calculated. Injury findings were correlated with the types of iaDRF (AO classification). In 159 patients (68.2 %), no SLIL injuries were seen. Minor SLIL injuries were detected in 54 patients (23.2 %), major injuries in 20 patients (8.6 %). No correlation was found between the presence of SLIL lesions and the types of iaDRF. Minor LTIL injuries were seen in 23 patients (9.9 %), major injuries in only 5 patients (2.2 %). The TFCC was altered in 141 patients (60.5 %). Interobserver variability was high for MDCT arthrography in assessing SLIL and TFC lesions, and fair for LTIL lesions. In iaDRF, prevalence of major injuries of the most relevant SLIL is about 9 % as evaluated with CT arthrography. (orig.)

  13. Our experience with the acceptance and dosimetric validation of Somatom Force dual head MDCT in the Royal Hospital, Oman

    International Nuclear Information System (INIS)

    Al-Harthi, Ruqaia; Al-Kalbani, Munira; Arun Kumar, L.S.; Al-Shanfari, Jamal

    2017-01-01

    Computed Tomography (CT) has revolutionized diagnostic imaging since its discovery in early 70's. In Oman; 70,353 CT examinations were carried out in the year 2015. The increase in CT examinations will eventually result in the increase of population dose and the consequent risk of cancer in adults and particularly in children. Here, we discuss and share our experience with the acceptance and dosimetric validation of second Dual Head Somatom Force MDCT installed in the Royal Hospital, Oman using Ministry of Health's radiation acceptance and quality assurance protocol, before handing over for routine patient care work

  14. Evaluation of multiple trauma victims with 16-row multidetector CT (MDCT): a time analysis; Anwendung der 16-Zeilen-Mehrdetektor-CT in der Initialdiagnostik beim Polytrauma: Eine Zeitanalyse

    Energy Technology Data Exchange (ETDEWEB)

    Heyer, C.M.; Nicolas, V. [Bochum Univ. (Germany). Inst. fuer Diagnostische Radiologie, Interventionelle Radiologie und Nuklearmedizin; Rduch, G.J. [Bochum Univ. (Germany). Klinik fuer Chirurgie; Wick, M.; Muhr, G. [Bochum Univ. (Germany). Medizinische Klinik III, Pneumologie, Allergologie und Schlafmedizin; Bauer, T.T. [Berufsgenossenschaftliche Kliniken Bergmannsheil, Ruhr-Univ. Bochum (Germany)

    2005-12-15

    Purpose: Description and time analysis of a 16-row MDCT protocol in the evaluation of multiple trauma patients considering transport, time of scanning, patient positioning, image reconstruction, and image interpretation. Materials and methods: Between May and December 2004, 60 multiple trauma patients underwent 16-row MDCT (Sensation, Siemens, Erlangen, Germany). The protocol included serial scanning of the head, spiral scanning of the cervical spine and contrast-enhanced spiral scanning of the thorax/abdomen with multiplanar reformations (MPR) of the thoracic/lumbar spine and the pelvis. All time intervals including transport, patient positioning, scanning, duration of MPR, total time in the examination room, and time to first and final image interpretation were prospectively evaluated. Furthermore, patient characteristics, trauma profiles, and mortality rates were recorded. Results: 46 male and 14 female patients (mean age 43.6 years) were enrolled in the study. Time analysis of 16-row MDCT revealed the following results (mean time standard deviation): Emergency room treatment and transport 19.2{+-}6.7 min, patient positioning 16.5{+-}6.5 min, scan duration 8.0{+-}3.3 min, total time in examination room 24.5{+-}7.2 min, image reconstruction including MPR 32.0{+-}16.4 min, and time of first (16.4{+-}4.7 min) and final image interpretation (82.5{+-}30.4 min). Trauma profiles revealed thoracic injuries in 35/60 patients (58.3%), head injuries in 23/60 patients (38.3%), abdominal injuries in 15/60 patients (25.0%), injuries of the cervical (9/60 patients, 15.0%), thoracic (12/60 patients, 20.0%), and lumbar spine (19/60 patients, 31.7%), pelvic injuries in 13/60 patients (21.7%), and injuries of extremities in 39/60 patients (65.0%). The mortality rate was 21.7%. (orig.)

  15. Contrast-enhanced MDCT gastrography for detection of early gastric cancer: Initial assessment of “wall-carving image”, a novel volume rendering technique

    International Nuclear Information System (INIS)

    Komori, Masahiro; Kawanami, Satoshi; Tsurumaru, Daisuke; Matsuura, Shuji; Hiraka, Kiyohisa; Nishie, Akihiro; Honda, Hiroshi

    2012-01-01

    Objective: We developed a new volume rendering technique, the CT gastrography wall carving image (WC) technique, which provides a clear visualization of localized enhanced tumors in the gastric wall. We evaluated the diagnostic performance of the WC as an adjunct to conventional images in detecting early gastric cancer (EGC). Materials and methods: Thirty-nine patients with 43 EGCs underwent contrast-enhanced MDCT gastrography for preoperative examination. Two observers independently reviewed the images under three different conditions: term 1, Axial CT; term 2, Axial CT, MPR and VE; and term 3, Axial CT, MPR, VE and WC for the detection of EGC. The accuracy of each condition as reviewed by each of the two observers was evaluated by receiver operating characteristic analysis. Interobserver agreement was calculated using weighted-κ statistics. Results: The best diagnostic performance and interobserver agreement were obtained in term 3. The AUCs of the two observers for terms 1, 2, and 3 were 0.63, 0.73, and 0.84, and 0.57, 0.73, and 0.76, respectively. The interobserver agreement improved from fair at term 1 to substantial at term 3. Conclusions: The addition of WC to conventional MDCT display improved the diagnostic accuracy and interobserver reproducibility for the detection of ECG. WC represents a suitable alternative for the visualization of localized enhanced tumors in the gastric wall.

  16. Variability of bronchial measurements obtained by sequential CT using two computer-based methods

    International Nuclear Information System (INIS)

    Brillet, Pierre-Yves; Fetita, Catalin I.; Mitrea, Mihai; Preteux, Francoise; Capderou, Andre; Dreuil, Serge; Simon, Jean-Marc; Grenier, Philippe A.

    2009-01-01

    This study aimed to evaluate the variability of lumen (LA) and wall area (WA) measurements obtained on two successive MDCT acquisitions using energy-driven contour estimation (EDCE) and full width at half maximum (FWHM) approaches. Both methods were applied to a database of segmental and subsegmental bronchi with LA > 4 mm 2 containing 42 bronchial segments of 10 successive slices that best matched on each acquisition. For both methods, the 95% confidence interval between repeated MDCT was between -1.59 and 1.5 mm 2 for LA, and -3.31 and 2.96 mm 2 for WA. The values of the coefficient of measurement variation (CV 10 , i.e., percentage ratio of the standard deviation obtained from the 10 successive slices to their mean value) were strongly correlated between repeated MDCT data acquisitions (r > 0.72; p 2 , whereas WA values were lower for bronchi with WA 2 ; no systematic EDCE underestimation or overestimation was observed for thicker-walled bronchi. In conclusion, variability between CT examinations and assessment techniques may impair measurements. Therefore, new parameters such as CV 10 need to be investigated to study bronchial remodeling. Finally, EDCE and FWHM are not interchangeable in longitudinal studies. (orig.)

  17. Influence of the Quantity of Aortic Valve Calcium on the Agreement Between Automated 3-Dimensional Transesophageal Echocardiography and Multidetector Row Computed Tomography for Aortic Annulus Sizing.

    Science.gov (United States)

    Podlesnikar, Tomaz; Prihadi, Edgard A; van Rosendael, Philippe J; Vollema, E Mara; van der Kley, Frank; de Weger, Arend; Ajmone Marsan, Nina; Naji, Franjo; Fras, Zlatko; Bax, Jeroen J; Delgado, Victoria

    2018-01-01

    Accurate aortic annulus sizing is key for selection of appropriate transcatheter aortic valve implantation (TAVI) prosthesis size. The present study compared novel automated 3-dimensional (3D) transesophageal echocardiography (TEE) software and multidetector row computed tomography (MDCT) for aortic annulus sizing and investigated the influence of the quantity of aortic valve calcium (AVC) on the selection of TAVI prosthesis size. A total of 83 patients with severe aortic stenosis undergoing TAVI were evaluated. Maximal and minimal aortic annulus diameter, perimeter, and area were measured. AVC was assessed with computed tomography. The low and high AVC burden groups were defined according to the median AVC score. Overall, 3D TEE measurements slightly underestimated the aortic annulus dimensions as compared with MDCT (mean differences between maximum, minimum diameter, perimeter, and area: -1.7 mm, 0.5 mm, -2.7 mm, and -13 mm 2 , respectively). The agreement between 3D TEE and MDCT on aortic annulus dimensions was superior among patients with low AVC burden (AVC burden (≥3,025 arbitrary units). The interobserver variability was excellent for both methods. 3D TEE and MDCT led to the same prosthesis size selection in 88%, 95%, and 81% of patients in the total population, the low, and the high AVC burden group, respectively. In conclusion, the novel automated 3D TEE imaging software allows accurate and highly reproducible measurements of the aortic annulus dimensions and shows excellent agreement with MDCT to determine the TAVI prosthesis size, particularly in patients with low AVC burden. Copyright © 2017 The Author(s). Published by Elsevier Inc. All rights reserved.

  18. Uterine radiation dose from open sources: The potential for underestimation

    International Nuclear Information System (INIS)

    Cox, P.H.; Klijn, J.G.M.; Pillay, M.; Bontebal, M.; Schoenfeld, D.H.W.

    1990-01-01

    Recent observations on the biodistribution of a therapeutic dose of sodium iodide I 131 in a patient with an unsuspected early pregnancy lead us to suspect that current dose estimates with respect to uterine exposure (ARSAC 1988) may seriously underestimate the actual exposure of the developing foetus. (orig.)

  19. Quantitative assessment of bone marrow attenuation values at MDCT: An objective tool for the detection of bone bruise related to occult sacral insufficiency fractures

    Energy Technology Data Exchange (ETDEWEB)

    Henes, F.O.; Groth, M.; Bley, T.A.; Regier, M.; Ittrich, H.; Adam, G.; Bannas, P. [University Medical Center Hamburg-Eppendorf, Department of Diagnostic and Interventional Radiology, Hamburg (Germany); Nuechtern, J.V. [University Medical Center Hamburg-Eppendorf, Department of Trauma, Hand and Reconstructive Surgery, Hamburg (Germany); Treszl, A. [University Medical Center Hamburg-Eppendorf, Center for Experimental Medicine, Department of Medical Biometry and Epidemiology, Hamburg (Germany)

    2012-10-15

    To prove the feasibility of using Hounsfield attenuation values at MDCT to detect bone bruises related to sacral insufficiency fractures. Twenty-two patients with acute sacrum trauma and no fracture findings at MDCT were included in our prospective study. Two observers independently reviewed CTs regarding visual signs of bone bruises in 132 defined regions of the sacral alae. Interobserver agreement was tested by {kappa} statistics. Subsequently, HU values were obtained in the same regions, and attenuation differences between the two sides were calculated. Validity and reliability were assessed by intraclass correlation coefficient and Bland-Altman analysis. HU differences were subjected to ROC curve analysis to determine sensitivity, specificity, PPV and NPV. MRI served as standard reference. MRI revealed 19 regions with bone bruises and associated sacral insufficiency fractures. HU measurements demonstrated good validity and reliability (r = 0.989). ROC curve analysis exhibited an ideal cutoff value of 35.7 HU density difference between affected and non-affected regions. Visual evaluation revealed moderate agreement ({kappa} = 0.48); diagnostic accuracy was inferior to objective evaluation. Assessment of differences in bone marrow density by HU measurements is an objective and reliable tool for detection of bone bruises associated with occult sacral insufficiency fractures. (orig.)

  20. NRC Information No. 90-21: Potential failure of motor-operated butterfly valves to operate because valve seat friction was underestimated

    International Nuclear Information System (INIS)

    Rossi, C.E.

    1992-01-01

    In October 1988, at Catawba Nuclear Station Unit 1, a motor-operated butterfly valve in the service water system failed to open under high differential pressure conditions. The licensee concluded that the valve manufacturer, BIF/General Signal Corporation, had underestimated the degree to which the material used in the valve seat would harden with age (the responsibility for these valves has been transferred to Paul-Munroe Enertech). This underestimation of the age hardening had led the manufacturer to assume valve seat friction forces that were less than the actual friction forces in the installed valve. To overcome the larger-than-anticipated friction forces, the licensee's engineering staff recommended the open torque switch for 56 butterfly valves be reset to the maximum allowable value. The systems in which these valves are located include the component cooling water system, service water system, and various ventilation systems. By July 26, 1989, the torque switch adjustments were completed at Catawba Units 1 and 2. After reviewing the final settings, the licensee's engineering staff determined that the actuators for three butterfly valves in the component cooling water system might not be able to overcome the friction forces resulting from maximum seat hardening. On December 13, 1989, the licensee determined that the failure of these BIF/General Signal motor-operated valves (MOVs) could cause a loss of cooling water to residual heat removal system heat exchangers. To resolve the concern regarding the operability of these BIF/General Signal valves, a torque switch bypass was installed on two of the actuators to allow full motor capability during opening

  1. Mucus: An Underestimated Gut Target for Environmental Pollutants and Food Additives.

    Science.gov (United States)

    Gillois, Kévin; Lévêque, Mathilde; Théodorou, Vassilia; Robert, Hervé; Mercier-Bonin, Muriel

    2018-06-15

    Synthetic chemicals (environmental pollutants, food additives) are widely used for many industrial purposes and consumer-related applications, which implies, through manufactured products, diet, and environment, a repeated exposure of the general population with growing concern regarding health disorders. The gastrointestinal tract is the first physical and biological barrier against these compounds, and thus their first target. Mounting evidence indicates that the gut microbiota represents a major player in the toxicity of environmental pollutants and food additives; however, little is known on the toxicological relevance of the mucus/pollutant interplay, even though mucus is increasingly recognized as essential in gut homeostasis. Here, we aimed at describing how environmental pollutants (heavy metals, pesticides, and other persistent organic pollutants) and food additives (emulsifiers, nanomaterials) might interact with mucus and mucus-related microbial species; that is, “mucophilic” bacteria such as mucus degraders. This review highlights that intestinal mucus, either directly or through its crosstalk with the gut microbiota, is a key, yet underestimated gut player that must be considered for better risk assessment and management of environmental pollution.

  2. Misery Has More Company Than People Think: Underestimating the Prevalence of Others’ Negative Emotions

    Science.gov (United States)

    Jordan, Alexander H.; Monin, Benoît; Dweck, Carol S.; Lovett, Benjamin J.; John, Oliver P.; Gross, James J.

    2014-01-01

    Four studies document underestimations of the prevalence of others’ negative emotions, and suggest causes and correlates of these erroneous perceptions. In Study 1A, participants reported that their negative emotions were more private or hidden than their positive emotions; in Study 1B, participants underestimated the peer prevalence of common negative, but not positive, experiences described in Study 1A. In Study 2, people underestimated negative emotions and overestimated positive emotions even for well-known peers, and this effect was partially mediated by the degree to which those peers reported suppression of negative (vs. positive) emotions. Study 3 showed that lower estimations of the prevalence of negative emotional experiences predicted greater loneliness and rumination and lower life satisfaction, and that higher estimations for positive emotional experiences predicted lower life satisfaction. Taken together, these studies suggest that people may think they are more alone in their emotional difficulties than they really are. PMID:21177878

  3. Consumer underestimation of sodium in fast food restaurant meals: Results from a cross-sectional observational study.

    Science.gov (United States)

    Moran, Alyssa J; Ramirez, Maricelle; Block, Jason P

    2017-06-01

    Restaurants are key venues for reducing sodium intake in the U.S. but little is known about consumer perceptions of sodium in restaurant foods. This study quantifies the difference between estimated and actual sodium content of restaurant meals and examines predictors of underestimation in adult and adolescent diners at fast food restaurants. In 2013 and 2014, meal receipts and questionnaires were collected from adults and adolescents dining at six restaurant chains in four New England cities. The sample included 993 adults surveyed during 229 dinnertime visits to 44 restaurants and 794 adolescents surveyed during 298 visits to 49 restaurants after school or at lunchtime. Diners were asked to estimate the amount of sodium (mg) in the meal they had just purchased. Sodium estimates were compared with actual sodium in the meal, calculated by matching all items that the respondent purchased for personal consumption to sodium information on chain restaurant websites. Mean (SD) actual sodium (mg) content of meals was 1292 (970) for adults and 1128 (891) for adolescents. One-quarter of diners (176 (23%) adults, 155 (25%) adolescents) were unable or unwilling to provide estimates of the sodium content of their meals. Of those who provided estimates, 90% of adults and 88% of adolescents underestimated sodium in their meals, with adults underestimating sodium by a mean (SD) of 1013 mg (1,055) and adolescents underestimating by 876 mg (1,021). Respondents underestimated sodium content more for meals with greater sodium content. Education about sodium at point-of-purchase, such as provision of sodium information on restaurant menu boards, may help correct consumer underestimation, particularly for meals of high sodium content. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. Contrast enhancement in multidetector-row computed tomography (MDCT) of the abdomen: intraindividual comparison of contrast media containing 300 mg versus 370 mg iodine per ml

    International Nuclear Information System (INIS)

    Behrendt, F.F.; Mahnken, A.H.; Keil, S.; Das, M.; Hohl, C.; Guenther, R.W.; Muehlenbruch, G.; Bauer, D.; Seidensticker, P.; Jost, E.; Wildberger, J.E.

    2008-01-01

    The purpose of this study was to intraindividually evaluate the difference in intraluminal vessel and parenchyma contrast enhancement of two different iodine concentrations in multidetector-row computed tomography (MDCT) of the abdomen. Eighty-three patients underwent baseline and follow-up MDCT-scanning (Somatom Sensation 16; Siemens, Forchheim, Germany) of the abdomen using contrast media containing 370 mg iodine/ml (protocol A; Ultravist 370, Bayer Schering Pharma, Berlin, Germany) and 300 mg iodine/ml (protocol B; Ultravist 300). The total iodine load (37 g iodine) and the iodine delivery rate (1.29 g iodine/s) were identical for both protocols. Contrast enhancement in the portal venous phase was measured in the abdominal aorta, inferior vena cava, portal vein, liver, spleen, pancreas and kidney. Mean attenuation values were compared using paired t-test. Intraindividual comparison revealed no statistically significant differences of the mean attenuation values between protocols A and B for all anatomic sites: abdominal aorta, inferior vena cava, portal vein, liver, spleen, pancreas and kidney (all P > 0.05). Given an injection protocol with constant total iodine load and constant iodine delivery rate, the iodine concentration of contrast media does not significantly influence abdominal contrast enhancement in the portal venous phase. (orig.)

  5. Hepatic Arterial Configuration in Relation to the Segmental Anatomy of the Liver; Observations on MDCT and DSA Relevant to Radioembolization Treatment

    International Nuclear Information System (INIS)

    Hoven, Andor F. van den; Leeuwen, Maarten S. van; Lam, Marnix G. E. H.; Bosch, Maurice A. A. J. van den

    2015-01-01

    PurposeCurrent anatomical classifications do not include all variants relevant for radioembolization (RE). The purpose of this study was to assess the individual hepatic arterial configuration and segmental vascularization pattern and to develop an individualized RE treatment strategy based on an extended classification.MethodsThe hepatic vascular anatomy was assessed on MDCT and DSA in patients who received a workup for RE between February 2009 and November 2012. Reconstructed MDCT studies were assessed to determine the hepatic arterial configuration (origin of every hepatic arterial branch, branching pattern and anatomical course) and the hepatic segmental vascularization territory of all branches. Aberrant hepatic arteries were defined as hepatic arterial branches that did not originate from the celiac axis/CHA/PHA. Early branching patterns were defined as hepatic arterial branches originating from the celiac axis/CHA.ResultsThe hepatic arterial configuration and segmental vascularization pattern could be assessed in 110 of 133 patients. In 59 patients (54 %), no aberrant hepatic arteries or early branching was observed. Fourteen patients without aberrant hepatic arteries (13 %) had an early branching pattern. In the 37 patients (34 %) with aberrant hepatic arteries, five also had an early branching pattern. Sixteen different hepatic arterial segmental vascularization patterns were identified and described, differing by the presence of aberrant hepatic arteries, their respective vascular territory, and origin of the artery vascularizing segment four.ConclusionsThe hepatic arterial configuration and segmental vascularization pattern show marked individual variability beyond well-known classifications of anatomical variants. We developed an individualized RE treatment strategy based on an extended anatomical classification

  6. The optimal dose reduction level using iterative reconstruction with prospective ECG-triggered coronary CTA using 256-slice MDCT

    International Nuclear Information System (INIS)

    Hou, Yang; Xu, Shu; Guo, Wenli; Vembar, Mani; Guo, Qiyong

    2012-01-01

    Aim: To assess the image quality (IQ) of an iterative reconstruction (IR) technique (iDose 4 ) from prospective electrocardiography (ECG)-triggered coronary computed tomography angiography (coronary CTA) on a 256-slice multi-detector CT (MDCT) scanner and determine the optimal dose reduction using IR that can provide IQ comparable to filtered back projection (FBP). Method and materials: 110 consecutive patients (69 men, 41 women; age: 54 ± 10 years) underwent coronary CTA on a 256-slice MDCT (Brilliance iCT, Philips Healthcare). The control group (Group A, n = 21) were scanned using the conventional tube output (120 kVp, 210 mAs) and reconstructed using FBP. The other 4 groups were scanned with the same kVp but successively reduced tube output as follows: B[n = 15]: 125 mAs; C[n = 22]: 105 mAs; D[n = 36]: 84 mAs: E[n = 16]: 65 mAs) and reconstructed using IR levels of L3 (Group B), L4 (Group C) and L5 (Groups D and E), to compensate for the noise increase. All images were reconstructed using the same kernel (XCB). Two radiologists graded IQ in a blinded fashion on a 4-point scale (4 – excellent, 3 – good, 2 – fair and 1 – poor). Quantitative measurements of CT values, image noise and contrast-to-noise (CNR) were measured in each group. A receiver-operating characteristic (ROC) analysis was performed to determine a radiation reduction threshold up to which excellent IQ was maintained. Results: There were no significant differences in objective noise, SNR and CNR values among Groups A, B, C, D, and E (P = 0.14, 0.09, 0.17, respectively). There were no significant differences in the scores of the subjective IQ between Group A, and Groups B, C, D, E (P = 0.23–0.97). Significant differences in image sharpness and study acceptability were observed between groups A and E (P < 0.05). Using the criterion of excellent IQ (score 4), the ROC curve of dose levels and IQ acceptability established a reduction of 60% of tube output (Group D) as optimum cutoff point (AUC

  7. Initial clinical experience with a 64-MDCT whole-body scanner in an emergency department: better time management and diagnostic quality?

    Science.gov (United States)

    Rieger, Michael; Czermak, Benedikt; El Attal, Rene; Sumann, Günther; Jaschke, Werner; Freund, Martin

    2009-03-01

    The objective of this study was to assess time management and diagnostic quality when using a 64-multidetector-row computed tomography (MDCT) whole-body scanner to evaluate polytraumatized patients in an emergency department. Eighty-eight consecutive polytraumatized patients with injury severity score (ISS) > or = 18 (mean ISS = 29) were included in this study. Documented and evaluated data were crash history, trauma mechanism, number and pattern of injuries, injury severity, diagnostics, time flow, and missed diagnoses. Data were stored in our hospital information system. Seven time intervals were evaluated. In particular, attention was paid to the "acquisition interval," the "reformatting and evaluation time" as well as the "CT time" (time from CT start to preliminary diagnosis). A standardized whole-body CT was performed. The acquired CT data together with automatically generated multiplanar reformatted images ("direct MPR") were transferred to a 3D rendering workstation. Diagnostic quality was determined on the basis of missed diagnoses. Head-to-toe scout images were possible because volume coverage was up to 2 m. Experienced radiologists at an affiliated workstation performed radiologic evaluation of the acquired datasets immediately after acquisition. The "acquisition interval" was 12 minutes +/- 4.9 minutes, the "reformatting and evaluation interval" 7.0 minutes +/- 2.1 minutes, and the "CT time" 19 minutes +/- 6.1 minutes. Altogether, 7 of 486 lesions were recognized but not communicated in the "reformatting and evaluation interval", and 10 injuries were initially missed and detected during follow-up. This study indicates that 64-MDCT saves time, especially in the "reformatting and evaluation interval." Diagnostic quality is high, as reflected by the small number of missed diagnoses.

  8. Effects of computing parameters and measurement locations on the estimation of 3D NPS in non-stationary MDCT images.

    Science.gov (United States)

    Miéville, Frédéric A; Bolard, Gregory; Bulling, Shelley; Gudinchet, François; Bochud, François O; Verdun, François R

    2013-11-01

    The goal of this study was to investigate the impact of computing parameters and the location of volumes of interest (VOI) on the calculation of 3D noise power spectrum (NPS) in order to determine an optimal set of computing parameters and propose a robust method for evaluating the noise properties of imaging systems. Noise stationarity in noise volumes acquired with a water phantom on a 128-MDCT and a 320-MDCT scanner were analyzed in the spatial domain in order to define locally stationary VOIs. The influence of the computing parameters in the 3D NPS measurement: the sampling distances bx,y,z and the VOI lengths Lx,y,z, the number of VOIs NVOI and the structured noise were investigated to minimize measurement errors. The effect of the VOI locations on the NPS was also investigated. Results showed that the noise (standard deviation) varies more in the r-direction (phantom radius) than z-direction plane. A 25 × 25 × 40 mm(3) VOI associated with DFOV = 200 mm (Lx,y,z = 64, bx,y = 0.391 mm with 512 × 512 matrix) and a first-order detrending method to reduce structured noise led to an accurate NPS estimation. NPS estimated from off centered small VOIs had a directional dependency contrary to NPS obtained from large VOIs located in the center of the volume or from small VOIs located on a concentric circle. This showed that the VOI size and location play a major role in the determination of NPS when images are not stationary. This study emphasizes the need for consistent measurement methods to assess and compare image quality in CT. Copyright © 2012 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

  9. Childhood leukaemia and low-level radiation - are we underestimating the risk?

    International Nuclear Information System (INIS)

    Wakeford, R.

    1996-01-01

    The Seascale childhood leukaemia 'cluster' can be interpreted as indicating that the risk of childhood leukaemia arising from low-level exposure to ionising radiation has been underestimated. Indeed, several variants of such an interpretation have been advanced. These include exposure to particular radionuclides, an underestimation of the radiation risk coefficient for childhood leukaemia, and the existence of a previously unrecognized risk of childhood leukaemia from the preconceptional irradiation of fathers. However, the scientific assessment of epidemiological associations is a complex matter, and such associations must be interpreted with caution. It would now seem most likely that the Seascale 'cluster' does not represent an unanticipated effect of the exposure to ionising radiation, but rather the effect of unusual population mixing generated by the Sellafield site which has produced an increase in the infection-based risk of childhood leukaemia. This episode in the history of epidemiological research provides a timely reminder of the need for great care in the interpretation-of novel statistical associations. (author)

  10. Underestimated Rate of Status Epilepticus according to the Traditional Definition of Status Epilepticus.

    Science.gov (United States)

    Ong, Cheung-Ter; Wong, Yi-Sin; Sung, Sheng-Feng; Wu, Chi-Shun; Hsu, Yung-Chu; Su, Yu-Hsiang; Hung, Ling-Chien

    2015-01-01

    Status epilepticus (SE) is an important neurological emergency. Early diagnosis could improve outcomes. Traditionally, SE is defined as seizures lasting at least 30 min or repeated seizures over 30 min without recovery of consciousness. Some specialists argued that the duration of seizures qualifying as SE should be shorter and the operational definition of SE was suggested. It is unclear whether physicians follow the operational definition. The objective of this study was to investigate whether the incidence of SE was underestimated and to investigate the underestimate rate. This retrospective study evaluates the difference in diagnosis of SE between operational definition and traditional definition of status epilepticus. Between July 1, 2012, and June 30, 2014, patients discharged with ICD-9 codes for epilepsy (345.X) in Chia-Yi Christian Hospital were included in the study. A seizure lasting at least 30 min or repeated seizures over 30 min without recovery of consciousness were considered SE according to the traditional definition of SE (TDSE). A seizure lasting between 5 and 30 min was considered SE according to the operational definition of SE (ODSE); it was defined as underestimated status epilepticus (UESE). During a 2-year period, there were 256 episodes of seizures requiring hospital admission. Among the 256 episodes, 99 episodes lasted longer than 5 min, out of which 61 (61.6%) episodes persisted over 30 min (TDSE) and 38 (38.4%) episodes continued between 5 and 30 min (UESE). In the 38 episodes of seizure lasting 5 to 30 minutes, only one episode was previously discharged as SE (ICD-9-CM 345.3). Conclusion. We underestimated 37.4% of SE. Continuing education regarding the diagnosis and treatment of epilepsy is important for physicians.

  11. The trauma concept: the role of MDCT in the diagnosis and management of visceral injuries

    Energy Technology Data Exchange (ETDEWEB)

    Becker, C.D.; Poletti, P.A. [Diagnostic and Interventional Radiology, Geneva Univ. Hospital (Switzerland)

    2005-11-15

    The imaging concept in the acute trauma victim includes abdominal ultrasonography during initial triage, and contrast-enhanced computed tomography (CT) for further assessment of visceral organ injuries and active bleeding sites if haemodynamic stability can be established during initial resuscitation. Integration of modern multidetector CT (MDCT) scanners in the emergency admission area greatly facilitates initial assessment of the extent of injuries in all body regions, and is therefore the emerging standard in all major centresinvolved in acute trauma care. Initial assessment of visceral injuries by means of CT not only allows determining the presence and extent of organ injuries and detecting active bleeding sources that may require transarterial embolisation for haemostasis, but also serves as a baseline for monitoring of conservative treatment. Specific indications for CT monitoring of conservative treatment exist in each individual organ. This concept enables the vast majority of blunt injuries of the parenchymal abdominal organs in the haemodynamically stable trauma victim to be managed without surgery. (orig.)

  12. The trauma concept: the role of MDCT in the diagnosis and management of visceral injuries

    International Nuclear Information System (INIS)

    Becker, C.D.; Poletti, P.A.

    2005-01-01

    The imaging concept in the acute trauma victim includes abdominal ultrasonography during initial triage, and contrast-enhanced computed tomography (CT) for further assessment of visceral organ injuries and active bleeding sites if haemodynamic stability can be established during initial resuscitation. Integration of modern multidetector CT (MDCT) scanners in the emergency admission area greatly facilitates initial assessment of the extent of injuries in all body regions, and is therefore the emerging standard in all major centresinvolved in acute trauma care. Initial assessment of visceral injuries by means of CT not only allows determining the presence and extent of organ injuries and detecting active bleeding sources that may require transarterial embolisation for haemostasis, but also serves as a baseline for monitoring of conservative treatment. Specific indications for CT monitoring of conservative treatment exist in each individual organ. This concept enables the vast majority of blunt injuries of the parenchymal abdominal organs in the haemodynamically stable trauma victim to be managed without surgery. (orig.)

  13. the Underestimation of Isorene in Houston during the Texas 2013 DISCOVER-AQ Campaign

    Science.gov (United States)

    Choi, Y.; Diao, L.; Czader, B.; Li, X.; Estes, M. J.

    2014-12-01

    This study applies principal component analysis to aircraft data from the Texas 2013 DISCOVER-AQ (Deriving Information on Surface Conditions from Column and Vertically Resolved Observations Relevant to Air Quality) field campaign to characterize isoprene sources over Houston during September 2013. The biogenic isoprene signature appears in the third principal component and anthropogenic signals in the following two. Evaluations of the Community Multiscale Air Quality (CMAQ) model simulations of isoprene with airborne measurements are more accurate for suburban areas than for industrial areas. This study also compares model outputs to eight surface automated gas chromatograph (Auto-GC) measurements near the Houston ship channel industrial area during the nighttime and shows that modeled anthropogenic isoprene is underestimated by a factor of 10.60. This study employs a new simulation with a modified anthropogenic emissions inventory (constraining using the ratios of observed values versus simulated ones) that yields closer isoprene predictions at night with a reduction in the mean bias by 56.93%, implying that model-estimated isoprene emissions from the 2008 National Emission Inventory are underestimated in the city of Houston and that other climate models or chemistry and transport models using the same emissions inventory might also be underestimated in other Houston-like areas in the United States.

  14. Evaluation of Tracheal and Main Bronchial Diverticula Using Thin-Section MDCT

    Energy Technology Data Exchange (ETDEWEB)

    Jou, Sung Shick; Kim, Young Tong; Bae, Won Kyung; Kim, Il Yung; Kim, Hyung Hwan; Han, Jong Kyu [Soonchunhyang University Cheonan Hospital, Cheonan (Korea, Republic of)

    2010-02-15

    To evaluate the characteristics of tracheal and main bronchial diverticula in relation with emphysema. A total of 967 CT images were reconstructed with 1.25 mm axial images over 2 months. The incidence, size, number, and location of the tracheal and main bronchial diverticula were analyzed using 3D medical software (Seoul, Korea). The incidence of emphysema and the relationship between emphysema and the size of the diverticula were analyzed. In total, 50 patients (5.1%) showed tracheal diverticula in the right posterolateral wall. In addition, 51 patients (5.2%) showed 89 (9.4%) main bronchial diverticula in the inferior wall, while 68 (72%) showed diverticula in the left posterolateral wall. Tracheal diverticula (6.4 {+-} 5.0 mm, 1.0 {+-} 0.2) were larger and fewer than the main bronchial diverticula (2.1 {+-} 2.0 mm, 1.8 {+-} 1.6) (p<0.05). Moreover, tracheal diverticula (10.3 {+-} 7.4 mm) with emphysema in 13 patients (26%), were larger than those without emphysema (5.1 {+-} 3.0 mm) (p<0.05). On thin-section MDCT, the rates of incidence for tracheal and main bronchial diverticula are about 5%, respectively. Tracheal diverticula in the right posterolateral wall are smaller and fewer than the main bronchial diverticula, which are located primarily in the inferior wall of the left bronchus. Tracheal diverticula with emphysema are larger than those without emphysema.

  15. Is dream recall underestimated by retrospective measures and enhanced by keeping a logbook? A review.

    Science.gov (United States)

    Aspy, Denholm J; Delfabbro, Paul; Proeve, Michael

    2015-05-01

    There are two methods commonly used to measure dream recall in the home setting. The retrospective method involves asking participants to estimate their dream recall in response to a single question and the logbook method involves keeping a daily record of one's dream recall. Until recently, the implicit assumption has been that these measures are largely equivalent. However, this is challenged by the tendency for retrospective measures to yield significantly lower dream recall rates than logbooks. A common explanation for this is that retrospective measures underestimate dream recall. Another is that keeping a logbook enhances it. If retrospective measures underestimate dream recall and if logbooks enhance it they are both unlikely to reflect typical dream recall rates and may be confounded with variables associated with the underestimation and enhancement effects. To date, this issue has received insufficient attention. The present review addresses this gap in the literature. Copyright © 2015 Elsevier Inc. All rights reserved.

  16. Fishermen´s underestimation of risk

    DEFF Research Database (Denmark)

    Knudsen, Fabienne; Grøn, Sisse

    2009-01-01

    to stress the positive potentiale of risk. This can be explained by several, interrelated factors such as the nature of fishing, it-self a risk-based enterprise; a life-form promoting independency and identification with the enterprise's pecuniary priorities; working conditions upholding a feeling......  Fishermen's underestimation of risk   Background: In order to understand the effect of footwear and flooring on slips, trips and falls, 1st author visited 4 fishing boats.  An important spinoff of the study was to get an in situ insight in the way, fishermen perceive risk.   Objectives......: The presentation will analyse fishermen's risk perception, its causes and consequences.   Methods: The first author participated in 3 voyages at sea on fishing vessels (from 1 to 10 days each and from 2 to 4 crewmembers) where  interviews and participant observation was undertaken. A 4th fishing boat was visited...

  17. Anatomical variations in the origins of the celiac axis and the superior mesenteric artery: MDCT angiographic findings and their probable embryological mechanisms.

    Science.gov (United States)

    Wang, Yi; Cheng, Cheng; Wang, Lu; Li, Ran; Chen, Jin-hua; Gong, Shui-gen

    2014-08-01

    To identify the spectrum and prevalence of anatomical variations in the origin of the celiac axis (CA), the superior mesenteric artery (SMA) and their major branches by using multidetector computed tomographic (MDCT) angiography. A retrospective evaluation was carried out on 1,500 abdominal MDCT angiography images. The aortic origins of the CA, the SMA and their major branch patterns were investigated. Normal aortic origins of CA and SMA were noted in 1,347 (89.8%) patients. Seven types of CA and SMA origin variants were identified in 153 (10.2%) patients. The three most common variations were hepatomesenteric trunk (67 patients, 4.47%), celiomesenteric trunk (CMT) (51 patients, 3.4%) and splenomesenteric trunk (18 patients, 1.2%). An evaluation of CMT was classified as long (34 patients, 66.7%) or short (17 patients, 33.3%) subtypes, compared with the length of the common trunk. Further CMT classification was based on the origin of the left gastric artery: subtype I, 26 patients (53.1%); subtype II, 5 patients (10.2%); subtype III, 15 patients (30.6%); subtype IV, 3 patients (6.1%). Dislocation interruption, incomplete interruption and persistence of the longitudinal anastomosis could be the embryological mechanisms of the variant origins of the CA, the SMA and their major branches. • Aortic origins of CA, SMA and their major branches were investigated. • Celiomesenteric trunk includes several different subtypes and configurations. • Probable embryological mechanisms of origin variants in these observed arteries were discussed. • Origin variants in these observed arteries have wide-ranging health implications.

  18. Sap flow is Underestimated by Thermal Dissipation Sensors due to Alterations of Wood Anatomy

    Science.gov (United States)

    Marañón-Jiménez, S.; Wiedemann, A.; van den Bulcke, J.; Cuntz, M.; Rebmann, C.; Steppe, K.

    2014-12-01

    The thermal dissipation technique (TD) is one of the most commonly adopted methods for sap flow measurements. However, underestimations of up to 60% of the tree transpiration have been reported with this technique, although the causes are not certainly known. The insertion of TD sensors within the stems causes damage of the wood tissue and subsequent healing reactions, changing wood anatomy and likely the sap flow path. However, the anatomical changes in response to the insertion of sap flow sensors and the effects on the measured flow have not been assessed yet. In this study, we investigate the alteration of vessel anatomy on wounds formed around TD sensors. Our main objectives were to elucidate the anatomical causes of sap flow underestimation for ring-porous and diffuse-porous species, and relate these changes to sap flow underestimations. Successive sets of TD probes were installed in early, mid and end of the growing season in Fagus sylvatica (diffuse-porous) and Quercus petraea (ring-porous) trees. They were logged after the growing season and additional sets of sensors were installed in the logged stems with presumably no healing reaction. The wood tissue surrounding each sensor was then excised and analysed by X-ray computed microtomography (X-ray micro CT). This technique allowed the quantification of vessel anatomical characteristics and the reconstruction of the 3-D internal microstructure of the xylem vessels so that extension and shape of the altered area could be determined. Gels and tyloses clogged the conductive vessels around the sensors in both beech and oak. The extension of the affected area was larger for beech although these anatomical changes led to similar sap flow underestimations in both species. The higher vessel size in oak may explain this result and, therefore, larger sap flow underestimation per area of affected conductive tissue. The wound healing reaction likely occurred within the first weeks after sensor installation, which

  19. FIA's volume-to-biomass conversion method (CRM) generally underestimates biomass in comparison to published equations

    Science.gov (United States)

    David. C. Chojnacky

    2012-01-01

    An update of the Jenkins et al. (2003) biomass estimation equations for North American tree species resulted in 35 generalized equations developed from published equations. These 35 equations, which predict aboveground biomass of individual species grouped according to a taxa classification (based on genus or family and sometimes specific gravity), generally predicted...

  20. Optimisation of the CT parameters with evaluation of MDCT double-scan images in the planning of the dental implant treatment

    International Nuclear Information System (INIS)

    Wojciechowski, W.; Urbanik, A.; Kownacki, P.; Kownacki, S.; Sowa, A.

    2009-01-01

    Background: The aim of the present study was optimisation of the examination parameters and evaluation of reliability of the MDCT double-scan images obtained with computer navigation for dental implant treatment. Material/Methods: With the use of a MDCT scanner SOMATOM Sensation (Siemens), CT-images of a phantom were performed: slice-collimation (10 A - 0.75 mm, 10 A - 1.5 mm), slice-thickness (0.75, 1, 2, 3, 5 mm), pitch (0.5, 1, 1.5). Additionally, the analysis on various filters from H20f to H60f was performed. For study used a phantom of the human cadaver head. Qualitative analysis was done using Nobel Guide (Nobel Biocare, Sweden), assessing possible artefacts on the images, and measurements of the bone structure on all filters in comparison with the real image. Results: The quality of the phantom images was assessed as optimal for the slices thickness 0.75 and 1 mm. The use of various values of the pitch did not have statistically significant difference on the image quality. Application of various filters did not alter the parameters of the bone structure, however the use of lower filters (H30f and H40f) had a beneficial effect on the quality of 3D reconstruction. The arrangement of the 'window' parameters in CT seemed to have a greater influence on the measurement and evaluation of the bone structure. Conclusions: Slice-collimation and slice-thickness are the most important parameters in selection of the optimal scan-protocol. It is recommended to use in the postprocessing, the mentioned above parameter succession with the application of various filters (H30f and H60f) at a stable arrangement of the 'window' in the CT examination. (authors)

  1. What Can Computed Tomography Scans of the Thorax Show after Breast Surgery?

    Directory of Open Access Journals (Sweden)

    Afsaneh Alikhassi

    2016-06-01

    Full Text Available Background: Postoperative breast abnormalities after breast conserving surgery or modified radical mastectomy are frequently overlooked and inaccurately assessed or reported using multidetector computed tomography (MDCT. These inaccurate results may have legal ramifications for the clinicians, cause patients avoidable anxiety, and lead to additional unnecessary diagnostic follow-up testing and costs.Methods: The patients with a history of breast cancer who had undergone breast-conserving surgery or modified radical mastectomy up to 6 months prior to undergoing a thoracic MDCT scan consented and enrolled in this study. These patients underwent a thoracic MDCT scan either because of respiratory or cardiac clinical symptoms or as part of breast cancer staging.Results: Forty women were included in this study. Different postoperative breast changes observed on thoracic MDCT scans including fibrous scar tissue, fat necrosis, seroma, abscess, hematoma, and recurrent and residual tumor were described.Conclusions: MDCT scans offer sufficient evidence in many postoperative cases to allow a confident diagnosis. General radiologists who review thoracic MDCT scans should know how to characterize breast lesions incidentally found on MDCT scans after breast surgeries. This information would enhance the value of the radiologist’s report for appropriate case management.

  2. Comparison of sensitivity and reading time for the use of computer-aided detection (CAD) of pulmonary nodules at MDCT as concurrent or second reader

    International Nuclear Information System (INIS)

    Beyer, F.; Zierott, L.; Juergens, K.U.; Heindel, W.; Fallenberg, E.M.; Stoeckel, J.; Wormanns, D.

    2007-01-01

    The purpose of this study was to compare sensitivity for detection of pulmonary nodules in MDCT scans and reading time of radiologists when using CAD as the second reader (SR) respectively concurrent reader (CR). Four radiologists analyzed 50 chest MDCT scans chosen from clinical routine two times and marked all detected pulmonary nodules: first with CAD as CR (display of CAD results immediately in the reading session) and later (median 14 weeks) with CAD as SR (display of CAD markers after completion of first reading without CAD). A Siemens LungCAD prototype was used. Sensitivities for detection of nodules and reading times were recorded. Sensitivity of reading with CAD as SR was significantly higher than reading without CAD (p < 0.001) and CAD as CR (p < 0.001). For nodule size of 1.75 mm or above no significant sensitivity difference between CAD as CR and reading without CAD was observed; e.g., for nodules above 4 mm sensitivity was 68% without CAD, 68% with CAD as CR (p 0.45) and 75% with CAD as SR (p < 0.001). Reading time was significantly shorter for CR (274 s) compared to reading without CAD (294 s; p = 0.04) and SR (337 s; p < 0.001). In our study CAD could either speed up reading of chest CT cases for pulmonary nodules without relevant loss of sensitivity when used as CR, or it increased sensitivity at the cost of longer reading times when used as SR. (orig.)

  3. Guiding exploration in conformational feature space with Lipschitz underestimation for ab-initio protein structure prediction.

    Science.gov (United States)

    Hao, Xiaohu; Zhang, Guijun; Zhou, Xiaogen

    2018-04-01

    Computing conformations which are essential to associate structural and functional information with gene sequences, is challenging due to the high dimensionality and rugged energy surface of the protein conformational space. Consequently, the dimension of the protein conformational space should be reduced to a proper level, and an effective exploring algorithm should be proposed. In this paper, a plug-in method for guiding exploration in conformational feature space with Lipschitz underestimation (LUE) for ab-initio protein structure prediction is proposed. The conformational space is converted into ultrafast shape recognition (USR) feature space firstly. Based on the USR feature space, the conformational space can be further converted into Underestimation space according to Lipschitz estimation theory for guiding exploration. As a consequence of the use of underestimation model, the tight lower bound estimate information can be used for exploration guidance, the invalid sampling areas can be eliminated in advance, and the number of energy function evaluations can be reduced. The proposed method provides a novel technique to solve the exploring problem of protein conformational space. LUE is applied to differential evolution (DE) algorithm, and metropolis Monte Carlo(MMC) algorithm which is available in the Rosetta; When LUE is applied to DE and MMC, it will be screened by the underestimation method prior to energy calculation and selection. Further, LUE is compared with DE and MMC by testing on 15 small-to-medium structurally diverse proteins. Test results show that near-native protein structures with higher accuracy can be obtained more rapidly and efficiently with the use of LUE. Copyright © 2018 Elsevier Ltd. All rights reserved.

  4. Multidetector Computed Tomography (MDCT in Gastrointestinal Obstruction: One Symptom Myriad Differentials

    Directory of Open Access Journals (Sweden)

    Geetika Sindhwani

    2017-10-01

    Full Text Available Introduction: Computed Tomography (CT is a highly sensitive modality with its multi-planar capabilities, used in evaluation of acute cases of intestinal obstruction. It delineates the level and helps to identify various etiologies of obstruction, where plain radiographs can only suggest signs of obstruction. It has an added advantage of detecting further complications, thus framing appropriate surgical approach. Aim: Our study aims at delineating variable CT spectrum of intestinal obstruction with highlight on atypical presentation. Materials and Methods: Retrospective hospital data based study was conducted in the Radiology Department of Shree Krishna Hospital, Anand, Gujarat, India, between 2014-2017 including 40 patients with mechanical causes of obstruction and excluding patients with non-mechanical causes of obstruction. Statistical analysis was done using percentages and proportions using MedCalc software version 17.6. Results: The age range of patients was from 5 days to 83 years and the maximum number of patients i.e., 7 (17.5% were in the age group of 41-50 years. Radiographic signs related to obstruction like air fluid levels, dilated bowel loops was seen in 26 out of 40 cases (sensitivity 60%. Small bowel obstruction dominated the case list with obstructed hernia as major causative factor. Conclusion: Study highlights the contribution of MDCT in early identification of underlying etiology and complications of obstruction with additional contribution in road mapping and framing appropriate and individualized treatment strategy for patients.

  5. Adult exposures from MDCT including multiphase studies: first Italian nationwide survey

    Energy Technology Data Exchange (ETDEWEB)

    Palorini, Federica; Origgi, Daniela [Fisica Sanitaria Istituto Europeo di Oncologia, Milan (Italy); Granata, Claudio [UOC di Radiologia Istituto Giannina Gaslini, Genoa (Italy); Matranga, Domenica [Universita degli Studi di Palermo, Dipartimento di Scienze per la Promozione della Salute e Materno-infantile ' ' G. D' Alessandro' ' , Palermo (Italy); Salerno, Sergio [Policlinico Universita di Palermo, Dipartimento di Scienze Radiologiche, Palermo (Italy)

    2014-02-15

    To evaluate the radiation dose in routine multidetector computed tomography (MDCT) examinations in Italian population. This was a retrospective multicentre study included 5,668 patients from 65 radiology departments who had undergone common CT protocols: head, chest, abdomen, chest-abdomen-pelvis (CAP), spine and cardiac. Data included patient characteristics, CT parameters, volumetric CT dose index (CTDI{sub vol}) and dose length product (DLP) for each CT acquisition phase. Descriptive statistics were calculated, and a multi-regression analysis was used to outline the main factors affecting exposure. The 75th percentiles of CTDI{sub vol} (mGy) and DLP (mGy cm) for whole head were 69 mGy and 1,312 mGy cm, respectively; for chest, 15 mGy and 569 mGy cm; spine, 42 mGy and 888 mGy cm; cardiac, 7 mGy and 131 mGy cm for calcium score, and 61 mGy and 1,208 mGy cm for angiographic CT studies. High variability was present in the DLP of abdomen and CAP protocols, where multiphase examinations dominated (71 % and 73 % respectively): for abdomen, 18 mGy, with 555 and 920 mGy cm in abdomen and abdomen-pelvis acquisitions respectively; for CAP, 17 mGy, with 508, 850 and 1,200 mGy cm in abdomen, abdomen-pelvis and CAP acquisitions respectively. The results of this survey could help in the definition of updated diagnostic reference levels (DRL). (orig.)

  6. Is dream recall underestimated by retrospective measures and enhanced by keeping a logbook? An empirical investigation.

    Science.gov (United States)

    Aspy, Denholm J

    2016-05-01

    In a recent review, Aspy, Delfabbro, and Proeve (2015) highlighted the tendency for retrospective measures of dream recall to yield substantially lower recall rates than logbook measures, a phenomenon they termed the retrospective-logbook disparity. One explanation for this phenomenon is that retrospective measures underestimate true dream recall. Another explanation is that keeping a logbook tends to enhance dream recall. The present study provides a thorough empirical investigation into the retrospective-logbook disparity using a range of retrospective and logbook measures and three different types of logbook. Retrospective-logbook disparities were correlated with a range of variables theoretically related to the retrospective underestimation effect, and retrospective-logbook disparities were greater among participants that reported improved dream recall during the logbook period. These findings indicate that dream recall is underestimated by retrospective measures and enhanced by keeping a logbook. Recommendations for the use of retrospective and logbook measures of dream recall are provided. Copyright © 2016 Elsevier Inc. All rights reserved.

  7. MDCT Evaluation of Left Atrium and Pulmonary Vein in the Patients with Atrial Fibrillation: Comparison with the Non-Atrial Fibrillation Group

    International Nuclear Information System (INIS)

    Kim, Won Jung; Choi, Eun Jeong; Ham, Soo Yeon; Oh, Yu Whan; Kim, Young Hoon; Yong, Hwan Seok; Yang, Kyung Sook

    2011-01-01

    The anatomy of the left atrium (LA) and the pulmonary veins (PVs) is important in planning and performing successful electrophysiologic ablation (EPA) for atrial fibrillation (Afib) patients. The authors estimated the findings of LA and PVs of Afib patients by MDCT, and compared these with the findings of LA and PVs of the non- Afib group using coronary CT angiography (CCTA). From September, 2009 to February, 2010, 91 Afib patients underwent PVCT (male: female = 72:19, mean age = 55.0-years-old) before EPA. At same time, 90 patients underwent CCTA (male: female = 73:17, mean age = 59.1- years-old). Two radiologists reviewed and analyzed all axial and 3D images of LA and PVs retrospectively with consensus. The average LA volumes of the Afib group(100.49 mm3) was larger than that of the non-Afib group (78.38 mm3) (p<0.05). The average lengths of the LA right wall in the Afib group (40.25 mm) was longer than that of the non-Afib group (37.3 mm) (p<0.05). The average distances between the PV ostium and first segmental bifurcation of the Lt superior PV (LSPV) and the RSPV were shorter in the Afib group (LSPV, 19.38 mm: RSPV, 11.49 mm) than in the non-Afib group (LSPV, 23.23 mm: RSPV, 14.25 mm) (p<0.05). There were higher incidences of anomalous branches such as ostial, accessory branches, or common ostia in the Afib group versus the non-Afib group (p<0.05). In Afib group, variable parameters of LA and PVs were obtained and estimated by MDCT, and there was statistically significant difference in the parameters of LA and PVs between Afib and non-Afib groups

  8. MDCT Evaluation of Left Atrium and Pulmonary Vein in the Patients with Atrial Fibrillation: Comparison with the Non-Atrial Fibrillation Group

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Won Jung; Choi, Eun Jeong; Ham, Soo Yeon; Oh, Yu Whan; Kim, Young Hoon [Anam Hospital, Korea University College of Medicine, Seoul (Korea, Republic of); Yong, Hwan Seok [Korea University Guro Hospital, Seoul (Korea, Republic of); Yang, Kyung Sook [Korea University, Seoul (Korea, Republic of)

    2011-02-15

    The anatomy of the left atrium (LA) and the pulmonary veins (PVs) is important in planning and performing successful electrophysiologic ablation (EPA) for atrial fibrillation (Afib) patients. The authors estimated the findings of LA and PVs of Afib patients by MDCT, and compared these with the findings of LA and PVs of the non- Afib group using coronary CT angiography (CCTA). From September, 2009 to February, 2010, 91 Afib patients underwent PVCT (male: female = 72:19, mean age = 55.0-years-old) before EPA. At same time, 90 patients underwent CCTA (male: female = 73:17, mean age = 59.1- years-old). Two radiologists reviewed and analyzed all axial and 3D images of LA and PVs retrospectively with consensus. The average LA volumes of the Afib group(100.49 mm3) was larger than that of the non-Afib group (78.38 mm3) (p<0.05). The average lengths of the LA right wall in the Afib group (40.25 mm) was longer than that of the non-Afib group (37.3 mm) (p<0.05). The average distances between the PV ostium and first segmental bifurcation of the Lt superior PV (LSPV) and the RSPV were shorter in the Afib group (LSPV, 19.38 mm: RSPV, 11.49 mm) than in the non-Afib group (LSPV, 23.23 mm: RSPV, 14.25 mm) (p<0.05). There were higher incidences of anomalous branches such as ostial, accessory branches, or common ostia in the Afib group versus the non-Afib group (p<0.05). In Afib group, variable parameters of LA and PVs were obtained and estimated by MDCT, and there was statistically significant difference in the parameters of LA and PVs between Afib and non-Afib groups

  9. Quantification of Underestimation of Physical Activity During Cycling to School When Using Accelerometry

    DEFF Research Database (Denmark)

    Tarp, Jakob; Andersen, Lars B; Østergaard, Lars

    2015-01-01

    Background: Cycling to and from school is an important source of physical activity (PA) in youth but it is not captured by the dominant objective method to quantify PA. The aim of this study was to quantify the underestimation of objectively assessed PA caused by cycling when using accelerometry....... Methods: Participants were 20 children aged 11-14 years from a randomized controlled trial performed in 2011. Physical activity was assessed by accelerometry with the addition of heart rate monitoring during cycling to school. Global positioning system (GPS) was used to identify periods of cycling...... to school. Results: Mean (95% CI) minutes of moderate-to-vigorous physical activity (MVPA) during round-trip commutes was 10.8 (7.1 - 16.6). Each kilometre of cycling meant an underestimation of 9314 (95%CI: 7719 - 11238) counts and 2.7 (95%CI: 2.1 - 3.5) minutes of MVPA. Adjusting for cycling to school...

  10. Impact of bowtie filter and object position on the two-dimensional noise power spectrum of a clinical MDCT system

    Energy Technology Data Exchange (ETDEWEB)

    Gomez-Cardona, Daniel; Cruz-Bastida, Juan Pablo [Department of Medical Physics, University of Wisconsin-Madison School of Medicine and Public Health, 1111 Highland Avenue, Madison, Wisconsin 53705 (United States); Li, Ke; Chen, Guang-Hong, E-mail: gchen7@wisc.edu [Department of Medical Physics, University of Wisconsin-Madison School of Medicine and Public Health, 1111 Highland Avenue, Madison, Wisconsin 53705 and Department of Radiology, University of Wisconsin-Madison School of Medicine and Public Health, 600 Highland Avenue, Madison, Wisconsin 53792 (United States); Budde, Adam; Hsieh, Jiang [Department of Medical Physics, University of Wisconsin-Madison School of Medicine and Public Health, 1111 Highland Avenue, Madison, Wisconsin 53705 and GE Healthcare, 3000 N Grandview Boulevard, Waukesha, Wisconsin 53188 (United States)

    2016-08-15

    Purpose: Noise characteristics of clinical multidetector CT (MDCT) systems can be quantified by the noise power spectrum (NPS). Although the NPS of CT has been extensively studied in the past few decades, the joint impact of the bowtie filter and object position on the NPS has not been systematically investigated. This work studies the interplay of these two factors on the two dimensional (2D) local NPS of a clinical CT system that uses the filtered backprojection algorithm for image reconstruction. Methods: A generalized NPS model was developed to account for the impact of the bowtie filter and image object location in the scan field-of-view (SFOV). For a given bowtie filter, image object, and its location in the SFOV, the shape and rotational symmetries of the 2D local NPS were directly computed from the NPS model without going through the image reconstruction process. The obtained NPS was then compared with the measured NPSs from the reconstructed noise-only CT images in both numerical phantom simulation studies and experimental phantom studies using a clinical MDCT scanner. The shape and the associated symmetry of the 2D NPS were classified by borrowing the well-known atomic spectral symbols s, p, and d, which correspond to circular, dumbbell, and cloverleaf symmetries, respectively, of the wave function of electrons in an atom. Finally, simulated bar patterns were embedded into experimentally acquired noise backgrounds to demonstrate the impact of different NPS symmetries on the visual perception of the object. Results: (1) For a central region in a centered cylindrical object, an s-wave symmetry was always present in the NPS, no matter whether the bowtie filter was present or not. In contrast, for a peripheral region in a centered object, the symmetry of its NPS was highly dependent on the bowtie filter, and both p-wave symmetry and d-wave symmetry were observed in the NPS. (2) For a centered region-ofinterest (ROI) in an off-centered object, the symmetry of

  11. Impact of bowtie filter and object position on the two-dimensional noise power spectrum of a clinical MDCT system

    International Nuclear Information System (INIS)

    Gomez-Cardona, Daniel; Cruz-Bastida, Juan Pablo; Li, Ke; Chen, Guang-Hong; Budde, Adam; Hsieh, Jiang

    2016-01-01

    Purpose: Noise characteristics of clinical multidetector CT (MDCT) systems can be quantified by the noise power spectrum (NPS). Although the NPS of CT has been extensively studied in the past few decades, the joint impact of the bowtie filter and object position on the NPS has not been systematically investigated. This work studies the interplay of these two factors on the two dimensional (2D) local NPS of a clinical CT system that uses the filtered backprojection algorithm for image reconstruction. Methods: A generalized NPS model was developed to account for the impact of the bowtie filter and image object location in the scan field-of-view (SFOV). For a given bowtie filter, image object, and its location in the SFOV, the shape and rotational symmetries of the 2D local NPS were directly computed from the NPS model without going through the image reconstruction process. The obtained NPS was then compared with the measured NPSs from the reconstructed noise-only CT images in both numerical phantom simulation studies and experimental phantom studies using a clinical MDCT scanner. The shape and the associated symmetry of the 2D NPS were classified by borrowing the well-known atomic spectral symbols s, p, and d, which correspond to circular, dumbbell, and cloverleaf symmetries, respectively, of the wave function of electrons in an atom. Finally, simulated bar patterns were embedded into experimentally acquired noise backgrounds to demonstrate the impact of different NPS symmetries on the visual perception of the object. Results: (1) For a central region in a centered cylindrical object, an s-wave symmetry was always present in the NPS, no matter whether the bowtie filter was present or not. In contrast, for a peripheral region in a centered object, the symmetry of its NPS was highly dependent on the bowtie filter, and both p-wave symmetry and d-wave symmetry were observed in the NPS. (2) For a centered region-ofinterest (ROI) in an off-centered object, the symmetry of

  12. Consequences of neurologic lesions assessed by Barthel Index after Botox® injection may be underestimated

    Directory of Open Access Journals (Sweden)

    Dionyssiotis Y

    2012-10-01

    Full Text Available Y Dionyssiotis,1,2 D Kiourtidis,3 A Karvouni,3 A Kaliontzoglou,3 I Kliafas31Medical Department, Rehabilitation Center Amyntaio, General Hospital of Florina, Amyntaio, Florina, 2Physical Medicine and Rehabilitation Department, Rhodes General Hospital, Rhodes, Dodecanese, 3Neurologic Department, Rhodes General Hospital, Rhodes, Dodecanese, GreecePurpose: The aim of this study was to investigate whether the consequences of neurologic lesions are underestimated when the Barthel Index (BI is used to assess the clinical outcome of botulinum toxin injection.Patients and methods: The records for all in- and outpatients with various neurologic lesions (stroke, multiple sclerosis, spinal cord injury, traumatic brain injury, and so forth who had been referred to the authors’ departments and who had received botulinum toxin type A (Botox® for spasticity within a 4-year period (2008–2011 were examined retrospectively. BI data were collected and analyzed.Results: The BI score was found to have increased in follow-up assessments (P = 0.048. No correlation was found between the degree of spasticity and the BI score.Conclusion: The specific injection of Botox in patients with neurologic lesions was not strongly correlated with a significant functional outcome according to the BI. The results of this study suggest that clinicians need to look at other measurement scales for the assessment of significant outcomes of Botox in the rehabilitation process after neurologic lesions.Keywords: botulinum toxin type A, spasticity, stroke, multiple sclerosis

  13. Impact bias or underestimation? Outcome specifications predict the direction of affective forecasting errors.

    Science.gov (United States)

    Buechel, Eva C; Zhang, Jiao; Morewedge, Carey K

    2017-05-01

    Affective forecasts are used to anticipate the hedonic impact of future events and decide which events to pursue or avoid. We propose that because affective forecasters are more sensitive to outcome specifications of events than experiencers, the outcome specification values of an event, such as its duration, magnitude, probability, and psychological distance, can be used to predict the direction of affective forecasting errors: whether affective forecasters will overestimate or underestimate its hedonic impact. When specifications are positively correlated with the hedonic impact of an event, forecasters will overestimate the extent to which high specification values will intensify and low specification values will discount its impact. When outcome specifications are negatively correlated with its hedonic impact, forecasters will overestimate the extent to which low specification values will intensify and high specification values will discount its impact. These affective forecasting errors compound additively when multiple specifications are aligned in their impact: In Experiment 1, affective forecasters underestimated the hedonic impact of winning a smaller prize that they expected to win, and they overestimated the hedonic impact of winning a larger prize that they did not expect to win. In Experiment 2, affective forecasters underestimated the hedonic impact of a short unpleasant video about a temporally distant event, and they overestimated the hedonic impact of a long unpleasant video about a temporally near event. Experiments 3A and 3B showed that differences in the affect-richness of forecasted and experienced events underlie these differences in sensitivity to outcome specifications, therefore accounting for both the impact bias and its reversal. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  14. The role of underestimating body size for self-esteem and self-efficacy among grade five children in Canada.

    Science.gov (United States)

    Maximova, Katerina; Khan, Mohammad K A; Austin, S Bryn; Kirk, Sara F L; Veugelers, Paul J

    2015-10-01

    Underestimating body size hinders healthy behavior modification needed to prevent obesity. However, initiatives to improve body size misperceptions may have detrimental consequences on self-esteem and self-efficacy. Using sex-specific multiple mixed-effect logistic regression models, we examined the association of underestimating versus accurate body size perceptions with self-esteem and self-efficacy in a provincially representative sample of 5075 grade five school children. Body size perceptions were defined as the standardized difference between the body mass index (BMI, from measured height and weight) and self-perceived body size (Stunkard body rating scale). Self-esteem and self-efficacy for physical activity and healthy eating were self-reported. Most of overweight boys and girls (91% and 83%); and most of obese boys and girls (93% and 90%) underestimated body size. Underestimating weight was associated with greater self-efficacy for physical activity and healthy eating among normal-weight children (odds ratio: 1.9 and 1.6 for boys, 1.5 and 1.4 for girls) and greater self-esteem among overweight and obese children (odds ratio: 2.0 and 6.2 for boys, 2.0 and 3.4 for girls). Results highlight the importance of developing optimal intervention strategies as part of targeted obesity prevention efforts that de-emphasize the focus on body weight, while improving body size perceptions. Copyright © 2015 Elsevier Inc. All rights reserved.

  15. Predictive equations underestimate resting energy expenditure in female adolescents with phenylketonuria

    Science.gov (United States)

    Quirk, Meghan E.; Schmotzer, Brian J.; Schmotzer, Brian J.; Singh, Rani H.

    2010-01-01

    Resting energy expenditure (REE) is often used to estimate total energy needs. The Schofield equation based on weight and height has been reported to underestimate REE in female children with phenylketonuria (PKU). The objective of this observational, cross-sectional study was to evaluate the agreement of measured REE with predicted REE for female adolescents with PKU. A total of 36 females (aged 11.5-18.7 years) with PKU attending Emory University’s Metabolic Camp (June 2002 – June 2008) underwent indirect calorimetry. Measured REE was compared to six predictive equations using paired Student’s t-tests, regression-based analysis, and assessment of clinical accuracy. The differences between measured and predicted REE were modeled against clinical parameters to determine to if a relationship existed. All six selected equations significantly under predicted measured REE (P< 0.005). The Schofield equation based on weight had the greatest level of agreement, with the lowest mean prediction bias (144 kcal) and highest concordance correlation coefficient (0.626). However, the Schofield equation based on weight lacked clinical accuracy, predicting measured REE within ±10% in only 14 of 36 participants. Clinical parameters were not associated with bias for any of the equations. Predictive equations underestimated measured REE in this group of female adolescents with PKU. Currently, there is no accurate and precise alternative for indirect calorimetry in this population. PMID:20497783

  16. Quantifying the underestimation of relative risks from genome-wide association studies.

    Directory of Open Access Journals (Sweden)

    Chris Spencer

    2011-03-01

    Full Text Available Genome-wide association studies (GWAS have identified hundreds of associated loci across many common diseases. Most risk variants identified by GWAS will merely be tags for as-yet-unknown causal variants. It is therefore possible that identification of the causal variant, by fine mapping, will identify alleles with larger effects on genetic risk than those currently estimated from GWAS replication studies. We show that under plausible assumptions, whilst the majority of the per-allele relative risks (RR estimated from GWAS data will be close to the true risk at the causal variant, some could be considerable underestimates. For example, for an estimated RR in the range 1.2-1.3, there is approximately a 38% chance that it exceeds 1.4 and a 10% chance that it is over 2. We show how these probabilities can vary depending on the true effects associated with low-frequency variants and on the minor allele frequency (MAF of the most associated SNP. We investigate the consequences of the underestimation of effect sizes for predictions of an individual's disease risk and interpret our results for the design of fine mapping experiments. Although these effects mean that the amount of heritability explained by known GWAS loci is expected to be larger than current projections, this increase is likely to explain a relatively small amount of the so-called "missing" heritability.

  17. Blunt chest trauma--an audit of injuries diagnosed by the MDCT examination.

    Science.gov (United States)

    Turkalj, Ivan; Petrović, Kosta; Stojanović, Sanja; Petrović, Djordje; Brakus, Alma; Ristić, Jelena

    2014-02-01

    Multidetector computed tomography (MDCT) characterised by speed and precision is increasingly accessible in emergency wards. The aim of our study was to determine the most common injuries to the chest region, as well as type associated extrathoracic injuries, and the treatment outcome. This prospective study included 61 patients with blunt trauma who were submitted to computed tomography (CT) of the thorax. The number of injuries was evaluated by organs and organ systems of the chest. The cause of the injury, the length and the outcome of the treatment, and the presence of injuries in other regions were assessed. Chest injuries were associated with injuries to other regions in 80.3% cases, predominantly injuries to extremities or pelvic bones in 54.1% cases, followed by head injuries in 39.3% patients. Associated thoracic injuries were present in 90.9% of patients with lethal outcome. Lung parenchymal lesions, pleural effusions and rib fractures were the most common injuries affecting 77.1%, 65.6% and 63.9% of the cases, respectively. Blunt chest trauma is a significant problem affecting predominantly males in their forties and it is usually caused by a motor vehicle accident. In case of pneumomediastinum or mediastinal haematoma, the use of 3D reconstructions is advised for diagnosing possible tracheobronchial ruptures and thoracic aorta injuries. Increased resolution of CT scanners yielded a large number of findings that are occult on radiography, especially in the event of lung parenchymal and pleural injuries. However, none imaging modality can replace surgical judgement.

  18. Predictors of underestimation of malignancy after image-guided core needle biopsy diagnosis of flat epithelial atypia or atypical ductal hyperplasia.

    Science.gov (United States)

    Yu, Chi-Chang; Ueng, Shir-Hwa; Cheung, Yun-Chung; Shen, Shih-Che; Kuo, Wen-Lin; Tsai, Hsiu-Pei; Lo, Yung-Feng; Chen, Shin-Cheh

    2015-01-01

    Flat epithelial atypia (FEA) and atypical ductal hyperplasia (ADH) are precursors of breast malignancy. Management of FEA or ADH after image-guided core needle biopsy (CNB) remains controversial. The aim of this study was to evaluate malignancy underestimation rates after FEA or ADH diagnosis using image-guided CNB and to identify clinical characteristics and imaging features associated with malignancy as well as identify cases with low underestimation rates that may be treatable by observation only. We retrospectively reviewed 2,875 consecutive image-guided CNBs recorded in an electronic data base from January 2010 to December 2011 and identified 128 (4.5%) FEA and 83 (2.9%) ADH diagnoses (211 total cases). Of these, 64 (30.3%) were echo-guided CNB procedures and 147 (69.7%) mammography-guided CNBs. Twenty patients (9.5%) were upgraded to malignancy. Multivariate analysis indicated that age (OR = 1.123, p = 0.002, increase of 1 year), mass-type lesion with calcifications (OR = 8.213, p = 0.006), and ADH in CNB specimens (OR = 8.071, p = 0.003) were independent predictors of underestimation. In univariate analysis of echo-guided CNB (n = 64), mass with calcifications had the highest underestimation rate (p < 0.001). Multivariate analysis of 147 mammography-guided CNBs revealed that age (OR = 1.122, p = 0.040, increase of 1 year) and calcification distribution were significant independent predictors of underestimation. No FEA case in which, complete calcification retrieval was recorded after CNB was upgraded to malignancy. Older age at diagnosis on image-guided CNB was a predictor of malignancy underestimation. Mass with calcifications was more likely to be associated with malignancy, and in cases presenting as calcifications only, segmental distribution or linear shapes were significantly associated with upgrading. Excision after FEA or ADH diagnosis by image-guided CNB is warranted except for FEA diagnosed using mammography-guided CNB with complete calcification

  19. Automated Volumetric Mammographic Breast Density Measurements May Underestimate Percent Breast Density for High-density Breasts

    NARCIS (Netherlands)

    Rahbar, K.; Gubern Merida, A.; Patrie, J.T.; Harvey, J.A.

    2017-01-01

    RATIONALE AND OBJECTIVES: The purpose of this study was to evaluate discrepancy in breast composition measurements obtained from mammograms using two commercially available software methods for systematic trends in overestimation or underestimation compared to magnetic resonance-derived

  20. Inferring Perspective Versus Getting Perspective: Underestimating the Value of Being in Another Person's Shoes.

    Science.gov (United States)

    Zhou, Haotian; Majka, Elizabeth A; Epley, Nicholas

    2017-04-01

    People use at least two strategies to solve the challenge of understanding another person's mind: inferring that person's perspective by reading his or her behavior (theorization) and getting that person's perspective by experiencing his or her situation (simulation). The five experiments reported here demonstrate a strong tendency for people to underestimate the value of simulation. Predictors estimated a stranger's emotional reactions toward 50 pictures. They could either infer the stranger's perspective by reading his or her facial expressions or simulate the stranger's perspective by watching the pictures he or she viewed. Predictors were substantially more accurate when they got perspective through simulation, but overestimated the accuracy they had achieved by inferring perspective. Predictors' miscalibrated confidence stemmed from overestimating the information revealed through facial expressions and underestimating the similarity in people's reactions to a given situation. People seem to underappreciate a useful strategy for understanding the minds of others, even after they gain firsthand experience with both strategies.

  1. [Comparison of 64 MDCT coronary CTA and coronary angiography in the detection of coronary artery stenosis in low risk patients with stable angina and acute coronary syndrome].

    Science.gov (United States)

    Cazalas, G; Sarran, A; Amabile, N; Chaumoitre, K; Marciano-Chagnaud, S; Jacquier, A; Paganelli, F; Panuel, M

    2009-09-01

    To determine the accuracy of 64 MDCT coronary CTA (CCTA) compared to coronary angiography in low risk patients with stable angina and acute coronary syndrome and determine the number of significant coronary artery stenoses ( 50%) in these patients. Materials and methods. Fifty-five patients underwent CCTA using a 32 MDCT unit with z flying focus allowing the acquisition of 64 slices of 0.6 mm thickness as well as coronary angiography (gold standard). Nine patients were excluded due to prior coronary artery bypass surgery (n=4), insufficient breath hold (n=3), calcium scoring>1000 (n=1) and delay between both examinations over 4 months (n=1). Forty-six patients: 27 males and 19 females were included. CCTA results were compared to coronary angiography per segment and artery with threshold detection of stenoses 50%. The degree of correlation between both examinations was performed using a regression analysis with a Pearson correlation coefficient<0.05 considered significant. The overall accuracy of CCTA was 90%; limitations related to the presence of calcifications, motion artifacts or insufficient vessel opacification. The correlation for all analyzed segments was 96.4%. Thirty-eight of 50 significant stenoses seen on coronary angiography were correctly detected on CCTA. Sensitivity, specificity, PPVC and NPV for detection of stenoses 50% were 76%, 98.3%, 80.3% and 97.7% respectively. Evaluation per segment had a NPV of 96.8% (interventricular and diagonal segments) to 100% (main trunk). Our results for specificity and NPV are similar to reports from the literature. This suggests that CCTA in this clinical setting may replace coronary angiography.

  2. A Numerical Study of Water Loss Rate Distributions in MDCT-based Human Airway Models

    Science.gov (United States)

    Wu, Dan; Miyawaki, Shinjiro; Tawhai, Merryn H.; Hoffman, Eric A.; Lin, Ching-Long

    2015-01-01

    Both three-dimensional (3D) and one-dimensional (1D) computational fluid dynamics (CFD) methods are applied to study regional water loss in three multi-detector row computed-tomography (MDCT)-based human airway models at the minute ventilations of 6, 15 and 30 L/min. The overall water losses predicted by both 3D and 1D models in the entire respiratory tract agree with available experimental measurements. However, 3D and 1D models reveal different regional water loss rate distributions due to the 3D secondary flows formed at bifurcations. The secondary flows cause local skewed temperature and humidity distributions on inspiration acting to elevate the local water loss rate; and the secondary flow at the carina tends to distribute more cold air to the lower lobes. As a result, the 3D model predicts that the water loss rate first increases with increasing airway generation, and then decreases as the air approaches saturation, while the 1D model predicts a monotonic decrease of water loss rate with increasing airway generation. Moreover, the 3D (or 1D) model predicts relatively higher water loss rates in lower (or upper) lobes. The regional water loss rate can be related to the non-dimensional wall shear stress (τ*) by the non-dimensional mass transfer coefficient (h0*) as h0* = 1.15 τ*0.272, R = 0.842. PMID:25869455

  3. Lesion stiffness measured by shear-wave elastography: Preoperative predictor of the histologic underestimation of US-guided core needle breast biopsy.

    Science.gov (United States)

    Park, Ah Young; Son, Eun Ju; Kim, Jeong-Ah; Han, Kyunghwa; Youk, Ji Hyun

    2015-12-01

    To determine whether lesion stiffness measured by shear-wave elastography (SWE) can be used to predict the histologic underestimation of ultrasound (US)-guided 14-gauge core needle biopsy (CNB) for breast masses. This retrospective study enrolled 99 breast masses from 93 patients, including 40 high-risk lesions and 59 ductal carcinoma in situ (DCIS), which were diagnosed by US-guided 14-gauge CNB. SWE was performed for all breast masses to measure quantitative elasticity values before US-guided CNB. To identify the preoperative factors associated with histologic underestimation, patients' age, symptoms, lesion size, B-mode US findings, and quantitative SWE parameters were compared according to the histologic upgrade after surgery using the chi-square test, Fisher's exact test, or independent t-test. The independent factors for predicting histologic upgrade were evaluated using multivariate logistic regression analysis. The underestimation rate was 28.3% (28/99) in total, 25.0% (10/40) in high-risk lesions, and 30.5% (18/59) in DCIS. All elasticity values of the upgrade group were significantly higher than those of the non-upgrade group (PBreast lesion stiffness quantitatively measured by SWE could be helpful to predict the underestimation of malignancy in US-guided 14-gauge CNB. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  4. Evaluation of the renal venous system on late arterial and venous phase images with MDCT angiography in potential living laparoscopic renal donors

    International Nuclear Information System (INIS)

    Kawamoto, S.; Lawler, L.P.; Fishman, E.K.

    2005-01-01

    Objective: The objective of our study was to assess whether both renal arteries and renal veins can be evaluated using single-phase MDCT data sets alone to eliminate the need for both arterial and venous phase data sets. Materials and methods: One hundred consecutive potential living renal donors who underwent 4- MDCT were evaluated. CT was performed with 120 mL of IV contrast material at an injection rate of 3 mL/sec. Both late arterial and venous phase acquisitions were obtained at 25 and 55 sec from the start of IV contrast injection, respectively. The number of the right and left renal veins and its anatomic variations were assessed by two reviewers. Late arterial phase images were evaluated initially, and then venous phase images were analyzed to assess opacification of the renal vein and to see whether venous phase data sets changed or added information about the venous anatomy as seen on late arterial phase images. Results: The retroaortic left renal vein was found in two subjects, and the circumaortic left renal vein was detected in three subjects. The renal veins were adequately opacified on late arterial phase images in all subjects. There were six subjects who had a normal left renal vein with a small posterior branch coursing posterior to the aorta and draining into the inferior vena cava, which were difficult to differentiate from the lumbar vein or ascending lumbar vein; in three of these six subjects, the small posterior branch was opacified only on venous phase images. Conclusion: Late arterial phase images obtained at 25 sec after the start of contrast injection can reveal the renal vein anatomy except for a small posterior branch of the left renal vein difficult to differentiate from the lumbar or ascending lumbar vein, as seen in three subjects. The data suggest that venous phase imaging is not necessary for the evaluation of renal vein anatomy. (author)

  5. Evaluation of the renal venous system on late arterial and venous phase images with MDCT angiography in potential living laparoscopic renal donors

    Energy Technology Data Exchange (ETDEWEB)

    Kawamoto, S.; Lawler, L.P.; Fishman, E.K. [Johns Hopkins Hospital, Baltimore, MD (United States). The Russell H. Morgan Department of Radiology and Radiological Science

    2005-03-15

    Objective: The objective of our study was to assess whether both renal arteries and renal veins can be evaluated using single-phase MDCT data sets alone to eliminate the need for both arterial and venous phase data sets. Materials and methods: One hundred consecutive potential living renal donors who underwent 4- MDCT were evaluated. CT was performed with 120 mL of IV contrast material at an injection rate of 3 mL/sec. Both late arterial and venous phase acquisitions were obtained at 25 and 55 sec from the start of IV contrast injection, respectively. The number of the right and left renal veins and its anatomic variations were assessed by two reviewers. Late arterial phase images were evaluated initially, and then venous phase images were analyzed to assess opacification of the renal vein and to see whether venous phase data sets changed or added information about the venous anatomy as seen on late arterial phase images. Results: The retroaortic left renal vein was found in two subjects, and the circumaortic left renal vein was detected in three subjects. The renal veins were adequately opacified on late arterial phase images in all subjects. There were six subjects who had a normal left renal vein with a small posterior branch coursing posterior to the aorta and draining into the inferior vena cava, which were difficult to differentiate from the lumbar vein or ascending lumbar vein; in three of these six subjects, the small posterior branch was opacified only on venous phase images. Conclusion: Late arterial phase images obtained at 25 sec after the start of contrast injection can reveal the renal vein anatomy except for a small posterior branch of the left renal vein difficult to differentiate from the lumbar or ascending lumbar vein, as seen in three subjects. The data suggest that venous phase imaging is not necessary for the evaluation of renal vein anatomy. (author)

  6. Value of gadoxetic acid-enhanced and diffusion-weighted MR imaging in evaluation of hepatocellular carcinomas with atypical enhancement pattern on contrast-enhanced multiphasic MDCT in patients with chronic liver disease

    International Nuclear Information System (INIS)

    Kim, Hyun Su; Kim, Seong Hyun; Kang, Tae Wook; Song, Kyoung Doo; Choi, Dongil; Park, Cheol Keun

    2015-01-01

    Highlights: •We investigated imaging findings on gadoxetic acid-enhanced MRI of HCCs without the typical enhancement pattern on multiphasic MDCT. •Most HCCs showed ancillary MR findings of typical HCC. •Considerable number of HCCs showed MR enhancement pattern of typical HCC. -- Abstract: Objective: The purpose of this study was to investigate the value of enhancement kinetics and ancillary imaging findings on gadoxetic acid-enhanced and diffusion-weighted (DW) MR imaging for diagnosing hepatocellular carcinomas (HCCs) without the typical enhancement pattern on contrast-enhanced multiphasic MDCT in patients with chronic liver disease. Materials and methods: Eighty-two surgically confirmed HCCs without the typical enhancement pattern (hypervascular in the arterial phase, followed by washout on the portal or equilibrium phases) on triple-phase MDCT were enrolled in this study. The patients were classified into four categories based on the CT density pattern of arterial and equilibrium phases (isodense–isodense, hypodense–hypodense, isodense–hypodense, and hyperdense–isodense) compared to liver parenchyma. Signal intensity of HCCs on T2-weighted images (T2WI), arterial phase, 3 min late-phase, hepatobiliary phase (HBP) and DW images with a b value of 800 s/mm 2 were qualitatively evaluated, and ADC values were measured. Fisher's exact test and Chi-square test were used to compare the frequency and trend of hyperintensity on T2WI, hypointensity on HBP images, hyperintensity on DW images, and histopathologic grades between groups with different CT density patterns. Kruskal–Wallis test was used to compare the ADC value between groups. Results: Thirty and 52 HCCs were categorized as hypervascular (hyperdense–isodense) and non-hypervascular HCCs (3, isodense–isodense; 37, hypodense–hypodense; 12, isodense–hypodense), respectively. Most HCCs showed hyperintensity on T2WI (77/82, 93.9%) and DW images (81/82, 98.8%) and hypointensity on HBP images

  7. Value of gadoxetic acid-enhanced and diffusion-weighted MR imaging in evaluation of hepatocellular carcinomas with atypical enhancement pattern on contrast-enhanced multiphasic MDCT in patients with chronic liver disease

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hyun Su [Department of Radiology and Center for Imaging Science, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50 Ilwon-dong, Gangnam-gu, Seoul (Korea, Republic of); Kim, Seong Hyun, E-mail: kshyun@skku.edu [Department of Radiology and Center for Imaging Science, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50 Ilwon-dong, Gangnam-gu, Seoul (Korea, Republic of); Kang, Tae Wook; Song, Kyoung Doo; Choi, Dongil [Department of Radiology and Center for Imaging Science, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50 Ilwon-dong, Gangnam-gu, Seoul (Korea, Republic of); Park, Cheol Keun [Department of Pathology, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50 Ilwon-dong, Gangnam-gu, Seoul 135-710 (Korea, Republic of)

    2015-04-15

    Highlights: •We investigated imaging findings on gadoxetic acid-enhanced MRI of HCCs without the typical enhancement pattern on multiphasic MDCT. •Most HCCs showed ancillary MR findings of typical HCC. •Considerable number of HCCs showed MR enhancement pattern of typical HCC. -- Abstract: Objective: The purpose of this study was to investigate the value of enhancement kinetics and ancillary imaging findings on gadoxetic acid-enhanced and diffusion-weighted (DW) MR imaging for diagnosing hepatocellular carcinomas (HCCs) without the typical enhancement pattern on contrast-enhanced multiphasic MDCT in patients with chronic liver disease. Materials and methods: Eighty-two surgically confirmed HCCs without the typical enhancement pattern (hypervascular in the arterial phase, followed by washout on the portal or equilibrium phases) on triple-phase MDCT were enrolled in this study. The patients were classified into four categories based on the CT density pattern of arterial and equilibrium phases (isodense–isodense, hypodense–hypodense, isodense–hypodense, and hyperdense–isodense) compared to liver parenchyma. Signal intensity of HCCs on T2-weighted images (T2WI), arterial phase, 3 min late-phase, hepatobiliary phase (HBP) and DW images with a b value of 800 s/mm{sup 2} were qualitatively evaluated, and ADC values were measured. Fisher's exact test and Chi-square test were used to compare the frequency and trend of hyperintensity on T2WI, hypointensity on HBP images, hyperintensity on DW images, and histopathologic grades between groups with different CT density patterns. Kruskal–Wallis test was used to compare the ADC value between groups. Results: Thirty and 52 HCCs were categorized as hypervascular (hyperdense–isodense) and non-hypervascular HCCs (3, isodense–isodense; 37, hypodense–hypodense; 12, isodense–hypodense), respectively. Most HCCs showed hyperintensity on T2WI (77/82, 93.9%) and DW images (81/82, 98.8%) and hypointensity on HBP

  8. Tritium: an underestimated health risk- 'ACROnic du nucleaire' nr 85, June 2009

    International Nuclear Information System (INIS)

    Barbey, Pierre

    2009-06-01

    After having indicated how tritium released in the environment (under the form of tritiated water or gas) is absorbed by living species, the author describes the different biological effects of ionizing radiations and the risk associated with tritium. He evokes how the radiation protection system is designed with respect to standards, and outlines how the risk related to tritium is underestimated by different existing models and standards. The author discusses the consequences of tritium transmutation and of the isotopic effect

  9. Evidence for link between modelled trends in Antarctic sea ice and underestimated westerly wind changes.

    Science.gov (United States)

    Purich, Ariaan; Cai, Wenju; England, Matthew H; Cowan, Tim

    2016-02-04

    Despite global warming, total Antarctic sea ice coverage increased over 1979-2013. However, the majority of Coupled Model Intercomparison Project phase 5 models simulate a decline. Mechanisms causing this discrepancy have so far remained elusive. Here we show that weaker trends in the intensification of the Southern Hemisphere westerly wind jet simulated by the models may contribute to this disparity. During austral summer, a strengthened jet leads to increased upwelling of cooler subsurface water and strengthened equatorward transport, conducive to increased sea ice. As the majority of models underestimate summer jet trends, this cooling process is underestimated compared with observations and is insufficient to offset warming in the models. Through the sea ice-albedo feedback, models produce a high-latitude surface ocean warming and sea ice decline, contrasting the observed net cooling and sea ice increase. A realistic simulation of observed wind changes may be crucial for reproducing the recent observed sea ice increase.

  10. Panoramic radiographs underestimate extensions of the anterior loop and mandibular incisive canal

    International Nuclear Information System (INIS)

    De Brito, Ana Caroline Ramos; Nejaim, Yuri; De Freitas, Deborah Queiroz; De Oliveira Santos, Christiano

    2016-01-01

    The purpose of this study was to detect the anterior loop of the mental nerve and the mandibular incisive canal in panoramic radiographs (PAN) and cone-beam computed tomography (CBCT) images, as well as to determine the anterior/mesial extension of these structures in panoramic and cross-sectional reconstructions using PAN and CBCT images. Images (both PAN and CBCT) from 90 patients were evaluated by 2 independent observers. Detection of the anterior loop and the incisive canal were compared between PAN and CBCT. The anterior/mesial extension of these structures was compared between PAN and both cross-sectional and panoramic CBCT reconstructions. In CBCT, the anterior loop and the incisive canal were observed in 7.7% and 24.4% of the hemimandibles, respectively. In PAN, the anterior loop and the incisive canal were detected in 15% and 5.5% of cases, respectively. PAN presented more difficulties in the visualization of structures. The anterior/mesial extensions ranged from 0.0 mm to 19.0 mm on CBCT. PAN underestimated the measurements by approximately 2.0 mm. CBCT appears to be a more reliable imaging modality than PAN for preoperative workups of the anterior mandible. Individual variations in the anterior/mesial extensions of the anterior loop of the mental nerve and the mandibular incisive canal mean that is not prudent to rely on a general safe zone for implant placement or bone surgery in the interforaminal region

  11. Panoramic radiographs underestimate extensions of the anterior loop and mandibular incisive canal

    Energy Technology Data Exchange (ETDEWEB)

    De Brito, Ana Caroline Ramos; Nejaim, Yuri; De Freitas, Deborah Queiroz [Dept. of Oral Diagnosis, Division of Oral Radiology, Piracicaba Dental School, University of Campinas, Sao Paulo (Brazil); De Oliveira Santos, Christiano [Dept. of Stomatology, Public Oral Health and Forensic Dentistry, School of Dentistry of Ribeirao Preto, University of Sao Paulo, Sao Paulo (Brazil)

    2016-09-15

    The purpose of this study was to detect the anterior loop of the mental nerve and the mandibular incisive canal in panoramic radiographs (PAN) and cone-beam computed tomography (CBCT) images, as well as to determine the anterior/mesial extension of these structures in panoramic and cross-sectional reconstructions using PAN and CBCT images. Images (both PAN and CBCT) from 90 patients were evaluated by 2 independent observers. Detection of the anterior loop and the incisive canal were compared between PAN and CBCT. The anterior/mesial extension of these structures was compared between PAN and both cross-sectional and panoramic CBCT reconstructions. In CBCT, the anterior loop and the incisive canal were observed in 7.7% and 24.4% of the hemimandibles, respectively. In PAN, the anterior loop and the incisive canal were detected in 15% and 5.5% of cases, respectively. PAN presented more difficulties in the visualization of structures. The anterior/mesial extensions ranged from 0.0 mm to 19.0 mm on CBCT. PAN underestimated the measurements by approximately 2.0 mm. CBCT appears to be a more reliable imaging modality than PAN for preoperative workups of the anterior mandible. Individual variations in the anterior/mesial extensions of the anterior loop of the mental nerve and the mandibular incisive canal mean that is not prudent to rely on a general safe zone for implant placement or bone surgery in the interforaminal region.

  12. Underestimated risks of recurrent long-range ash dispersal from northern Pacific Arc volcanoes.

    Science.gov (United States)

    Bourne, A J; Abbott, P M; Albert, P G; Cook, E; Pearce, N J G; Ponomareva, V; Svensson, A; Davies, S M

    2016-07-21

    Widespread ash dispersal poses a significant natural hazard to society, particularly in relation to disruption to aviation. Assessing the extent of the threat of far-travelled ash clouds on flight paths is substantially hindered by an incomplete volcanic history and an underestimation of the potential reach of distant eruptive centres. The risk of extensive ash clouds to aviation is thus poorly quantified. New evidence is presented of explosive Late Pleistocene eruptions in the Pacific Arc, currently undocumented in the proximal geological record, which dispersed ash up to 8000 km from source. Twelve microscopic ash deposits or cryptotephra, invisible to the naked eye, discovered within Greenland ice-cores, and ranging in age between 11.1 and 83.7 ka b2k, are compositionally matched to northern Pacific Arc sources including Japan, Kamchatka, Cascades and Alaska. Only two cryptotephra deposits are correlated to known high-magnitude eruptions (Towada-H, Japan, ca 15 ka BP and Mount St Helens Set M, ca 28 ka BP). For the remaining 10 deposits, there is no evidence of age- and compositionally-equivalent eruptive events in regional volcanic stratigraphies. This highlights the inherent problem of under-reporting eruptions and the dangers of underestimating the long-term risk of widespread ash dispersal for trans-Pacific and trans-Atlantic flight routes.

  13. X-ray computed microtomography characterizes the wound effect that causes sap flow underestimation by thermal dissipation sensors.

    Science.gov (United States)

    Marañón-Jiménez, S; Van den Bulcke, J; Piayda, A; Van Acker, J; Cuntz, M; Rebmann, C; Steppe, K

    2018-02-01

    Insertion of thermal dissipation (TD) sap flow sensors in living tree stems causes damage of the wood tissue, as is the case with other invasive methods. The subsequent wound formation is one of the main causes of underestimation of tree water-use measured by TD sensors. However, the specific alterations in wood anatomy in response to inserted sensors have not yet been characterized, and the linked dysfunctions in xylem conductance and sensor accuracy are still unknown. In this study, we investigate the anatomical mechanisms prompting sap flow underestimation and the dynamic process of wound formation. Successive sets of TD sensors were installed in the early, mid and end stage of the growing season in diffuse- and ring-porous trees, Fagus sylvatica (Linnaeus) and Quercus petraea ((Mattuschka) Lieblein), respectively. The trees were cut in autumn and additional sensors were installed in the cut stem segments as controls without wound formation. The wounded area and volume surrounding each sensor was then visually determined by X-ray computed microtomography (X-ray microCT). This technique allowed the characterization of vessel anatomical transformations such as tyloses formation, their spatial distribution and quantification of reduction in conductive area. MicroCT scans showed considerable formation of tyloses that reduced the conductive area of vessels surrounding the inserted TD probes, thus causing an underestimation in sap flux density (SFD) in both beech and oak. Discolored wood tissue was ellipsoidal, larger in the radial plane, more extensive in beech than in oak, and also for sensors installed for longer times. However, the severity of anatomical transformations did not always follow this pattern. Increased wound size with time, for example, did not result in larger SFD underestimation. This information helps us to better understand the mechanisms involved in wound effects with TD sensors and allows the provision of practical recommendations to reduce

  14. Republic of Georgia estimates for prevalence of drug use: Randomized response techniques suggest under-estimation.

    Science.gov (United States)

    Kirtadze, Irma; Otiashvili, David; Tabatadze, Mzia; Vardanashvili, Irina; Sturua, Lela; Zabransky, Tomas; Anthony, James C

    2018-06-01

    Validity of responses in surveys is an important research concern, especially in emerging market economies where surveys in the general population are a novelty, and the level of social control is traditionally higher. The Randomized Response Technique (RRT) can be used as a check on response validity when the study aim is to estimate population prevalence of drug experiences and other socially sensitive and/or illegal behaviors. To apply RRT and to study potential under-reporting of drug use in a nation-scale, population-based general population survey of alcohol and other drug use. For this first-ever household survey on addictive substances for the Country of Georgia, we used the multi-stage probability sampling of 18-to-64-year-old household residents of 111 urban and 49 rural areas. During the interviewer-administered assessments, RRT involved pairing of sensitive and non-sensitive questions about drug experiences. Based upon the standard household self-report survey estimate, an estimated 17.3% [95% confidence interval, CI: 15.5%, 19.1%] of Georgian household residents have tried cannabis. The corresponding RRT estimate was 29.9% [95% CI: 24.9%, 34.9%]. The RRT estimates for other drugs such as heroin also were larger than the standard self-report estimates. We remain unsure about what is the "true" value for prevalence of using illegal psychotropic drugs in the Republic of Georgia study population. Our RRT results suggest that standard non-RRT approaches might produce 'under-estimates' or at best, highly conservative, lower-end estimates. Copyright © 2018 Elsevier B.V. All rights reserved.

  15. Risk of contrast-medium-induced nephropathy in high-risk patients undergoing MDCT - A pooled analysis of two randomized trials

    International Nuclear Information System (INIS)

    Thomsen, Henrik S.; Morcos, Sameh K.

    2009-01-01

    The incidence of contrast-medium-induced nephropathy (CIN) following intravenous (IV) CM administration of contrast media to renally impaired patients undergoing multidetector computed tomography (MDCT) is not well characterized. Our objective was to investigate the incidence of CIN in patients with glomerular filtration rate (GFR) 40 ml/min, 4.6% when GFR <40 ml/min and 7.8% in patients with GFR <30 ml/min. The incidence of CIN was significantly higher after iodixanol than after LOCM (seven patients, 4.7% following IOCM, no CIN cases following the LOCM; p = 0.007). Significant differences in favor of the LOCM were also observed in patients with GFR <40 ml/min and GFR <30 ml/min. Following the IV administration of nonionic contrast agents in patients with moderate-to-severe renal insufficiency, the risk of significant CIN seems to be low. The IOCM iodixanol caused a higher rate of CIN than the LOCM iopamidol and iomeprol, especially in high-risk patients. Differences in osmolality between these LOCM and iodixanol do not play a role in the genesis of CIN. (orig.)

  16. A nonlinear generalization of the Savitzky-Golay filter and the quantitative analysis of saccades.

    Science.gov (United States)

    Dai, Weiwei; Selesnick, Ivan; Rizzo, John-Ross; Rucker, Janet; Hudson, Todd

    2017-08-01

    The Savitzky-Golay (SG) filter is widely used to smooth and differentiate time series, especially biomedical data. However, time series that exhibit abrupt departures from their typical trends, such as sharp waves or steps, which are of physiological interest, tend to be oversmoothed by the SG filter. Hence, the SG filter tends to systematically underestimate physiological parameters in certain situations. This article proposes a generalization of the SG filter to more accurately track abrupt deviations in time series, leading to more accurate parameter estimates (e.g., peak velocity of saccadic eye movements). The proposed filtering methodology models a time series as the sum of two component time series: a low-frequency time series for which the conventional SG filter is well suited, and a second time series that exhibits instantaneous deviations (e.g., sharp waves, steps, or more generally, discontinuities in a higher order derivative). The generalized SG filter is then applied to the quantitative analysis of saccadic eye movements. It is demonstrated that (a) the conventional SG filter underestimates the peak velocity of saccades, especially those of small amplitude, and (b) the generalized SG filter estimates peak saccadic velocity more accurately than the conventional filter.

  17. Presence of left atrial diverticula, accessory appendages, and normal variant pulmonary venous anatomy diagnosed using MDCT and adverse outcomes following radiofrequency catheter ablation therapy in patients with drug-refractory atrial fibrillation: An exploratory study

    International Nuclear Information System (INIS)

    Patel, S.N.; French, A.; Mathias, H.; Lyen, S.; Hamilton, M.C.K.; Manghat, N.E.

    2013-01-01

    Aim: To determine the frequency of normal variation left atrial anatomy (NVLAA) (diverticula, accessory appendages) and normal variation pulmonary venous anatomy (NVPVA) in patients with atrial fibrillation (AF), and to determine whether the presence of these entities is associated with an increased recurrence of atrial arrhythmias following radiofrequency catheter ablation (RFCA). Materials and methods: All cardiac MDCT images performed prior to RFCA between November 2009 and May 2011 in patients with drug-refractory AF were retrospectively evaluated. The presence, type, and location of NVLAA and NVPVA, and outcome of RFCA were recorded. Success was defined as restoration of sinus rhythm. Results: Forty-six consecutive patients with a mean age of 59.8 (±9.7) years (76.1% male) underwent cardiac MDCT for anatomical planning prior to RFCA procedures. Fourteen (30.4%) patients had NVLAA, 35% of patients had NVPVA. Thirty (65%) patients had successful RFCA: 57% of these had a NVLAA, 67% had NVPVA. Sixteen (35%) patients had unsuccessful RFCA: 63% of these had a NVLAA, 56% had NVPVA. There was no significant association between the presence of NVLAA (p = 0.699), NVPVA (p = 0.197), or “NVLAA in the presence of normal pulmonary venous anatomy” (p = 0.589) and the outcome of RFCA. Conclusion: The presence of NVLAA and NVPVA appears unrelated to adverse outcome in patients undergoing RFCA for the treatment of drug-refractory AF

  18. Completeness and underestimation of cancer mortality rate in Iran: a report from Fars Province in southern Iran.

    Science.gov (United States)

    Marzban, Maryam; Haghdoost, Ali-Akbar; Dortaj, Eshagh; Bahrampour, Abbas; Zendehdel, Kazem

    2015-03-01

    The incidence and mortality rates of cancer are increasing worldwide, particularly in the developing countries. Valid data are needed for measuring the cancer burden and making appropriate decisions toward cancer control. We evaluated the completeness of death registry with regard to cancer death in Fars Province, I. R. of Iran. We used data from three sources in Fars Province, including the national death registry (source 1), the follow-up data from the pathology-based cancer registry (source 2) and hospital based records (source 3) during 2004 - 2006. We used the capture-recapture method and estimated underestimation and the true age standardized mortality rate (ASMR) for cancer. We used log-linear (LL) modeling for statistical analysis. We observed 1941, 480, and 355 cancer deaths in sources 1, 2 and 3, respectively. After data linkage, we estimated that mortality registry had about 40% underestimation for cancer death. After adjustment for this underestimation rate, the ASMR of cancer in the Fars Province for all cancer types increased from 44.8 per 100,000 (95% CI: 42.8 - 46.7) to 76.3 per 100,000 (95% CI: 73.3 - 78.9), accounting for 3309 (95% CI: 3151 - 3293) cancer deaths annually. The mortality rate of cancer is considerably higher than the rates reported by the routine registry in Iran. Improvement in the validity and completeness of the mortality registry is needed to estimate the true mortality rate caused by cancer in Iran.

  19. The underestimated potential of solar energy to mitigate climate change

    Science.gov (United States)

    Creutzig, Felix; Agoston, Peter; Goldschmidt, Jan Christoph; Luderer, Gunnar; Nemet, Gregory; Pietzcker, Robert C.

    2017-09-01

    The Intergovernmental Panel on Climate Change's fifth assessment report emphasizes the importance of bioenergy and carbon capture and storage for achieving climate goals, but it does not identify solar energy as a strategically important technology option. That is surprising given the strong growth, large resource, and low environmental footprint of photovoltaics (PV). Here we explore how models have consistently underestimated PV deployment and identify the reasons for underlying bias in models. Our analysis reveals that rapid technological learning and technology-specific policy support were crucial to PV deployment in the past, but that future success will depend on adequate financing instruments and the management of system integration. We propose that with coordinated advances in multiple components of the energy system, PV could supply 30-50% of electricity in competitive markets.

  20. Adenocarcinoma of the uncinate process of the pancreas: MDCT patterns of local invasion and clinical features at presentation

    Energy Technology Data Exchange (ETDEWEB)

    Padilla-Thornton, Amie E.; Willmann, Juergen K.; Jeffrey, R.B. [Stanford University School of Medicine, Department of Radiology, Stanford, CA (United States)

    2012-05-15

    To compare the multidetector CT (MDCT) patterns of local invasion and clinical findings at presentation in patients with adenocarcinoma of the uncinate process of the pancreas to patients with adenocarcinomas in the non-uncinate head of the pancreas. We evaluated the two cohorts for common duct and pancreatic duct dilatation, mesenteric vascular encasement, root of mesentery invasion, perineural invasion and duodenal invasion. In addition, we compared the clinical findings at presentation in both groups. Common duct (P < 0.001) and pancreatic duct dilatation (P = 0.001) were significantly less common in uncinate process adenocarcinomas than in the non-uncinate head of the pancreas. Clinical findings of jaundice (P = 0.01) and pruritis (P = 0.004) were significantly more common in patients with lesions in the non-uncinate head of the pancreas. Superior mesenteric artery encasement (P = 0.02) and perineural invasion (P = 0.001) were significantly more common with uncinate process adenocarcinomas. Owing to its unique anatomic location, adenocarcinomas within the uncinate process of the pancreas have significantly different patterns of both local invasion and clinical presentation compared to patients with carcinomas in the non-uncinate head of the pancreas. (orig.)

  1. Novel prediction model of renal function after nephrectomy from automated renal volumetry with preoperative multidetector computed tomography (MDCT).

    Science.gov (United States)

    Isotani, Shuji; Shimoyama, Hirofumi; Yokota, Isao; Noma, Yasuhiro; Kitamura, Kousuke; China, Toshiyuki; Saito, Keisuke; Hisasue, Shin-ichi; Ide, Hisamitsu; Muto, Satoru; Yamaguchi, Raizo; Ukimura, Osamu; Gill, Inderbir S; Horie, Shigeo

    2015-10-01

    The predictive model of postoperative renal function may impact on planning nephrectomy. To develop the novel predictive model using combination of clinical indices with computer volumetry to measure the preserved renal cortex volume (RCV) using multidetector computed tomography (MDCT), and to prospectively validate performance of the model. Total 60 patients undergoing radical nephrectomy from 2011 to 2013 participated, including a development cohort of 39 patients and an external validation cohort of 21 patients. RCV was calculated by voxel count using software (Vincent, FUJIFILM). Renal function before and after radical nephrectomy was assessed via the estimated glomerular filtration rate (eGFR). Factors affecting postoperative eGFR were examined by regression analysis to develop the novel model for predicting postoperative eGFR with a backward elimination method. The predictive model was externally validated and the performance of the model was compared with that of the previously reported models. The postoperative eGFR value was associated with age, preoperative eGFR, preserved renal parenchymal volume (RPV), preserved RCV, % of RPV alteration, and % of RCV alteration (p volumetry and clinical indices might yield an important tool for predicting postoperative renal function.

  2. Adenocarcinoma of the uncinate process of the pancreas: MDCT patterns of local invasion and clinical features at presentation

    International Nuclear Information System (INIS)

    Padilla-Thornton, Amie E.; Willmann, Juergen K.; Jeffrey, R.B.

    2012-01-01

    To compare the multidetector CT (MDCT) patterns of local invasion and clinical findings at presentation in patients with adenocarcinoma of the uncinate process of the pancreas to patients with adenocarcinomas in the non-uncinate head of the pancreas. We evaluated the two cohorts for common duct and pancreatic duct dilatation, mesenteric vascular encasement, root of mesentery invasion, perineural invasion and duodenal invasion. In addition, we compared the clinical findings at presentation in both groups. Common duct (P < 0.001) and pancreatic duct dilatation (P = 0.001) were significantly less common in uncinate process adenocarcinomas than in the non-uncinate head of the pancreas. Clinical findings of jaundice (P = 0.01) and pruritis (P = 0.004) were significantly more common in patients with lesions in the non-uncinate head of the pancreas. Superior mesenteric artery encasement (P = 0.02) and perineural invasion (P = 0.001) were significantly more common with uncinate process adenocarcinomas. Owing to its unique anatomic location, adenocarcinomas within the uncinate process of the pancreas have significantly different patterns of both local invasion and clinical presentation compared to patients with carcinomas in the non-uncinate head of the pancreas. (orig.)

  3. Modeling microelectrode biosensors: free-flow calibration can substantially underestimate tissue concentrations.

    Science.gov (United States)

    Newton, Adam J H; Wall, Mark J; Richardson, Magnus J E

    2017-03-01

    Microelectrode amperometric biosensors are widely used to measure concentrations of analytes in solution and tissue including acetylcholine, adenosine, glucose, and glutamate. A great deal of experimental and modeling effort has been directed at quantifying the response of the biosensors themselves; however, the influence that the macroscopic tissue environment has on biosensor response has not been subjected to the same level of scrutiny. Here we identify an important issue in the way microelectrode biosensors are calibrated that is likely to have led to underestimations of analyte tissue concentrations. Concentration in tissue is typically determined by comparing the biosensor signal to that measured in free-flow calibration conditions. In a free-flow environment the concentration of the analyte at the outer surface of the biosensor can be considered constant. However, in tissue the analyte reaches the biosensor surface by diffusion through the extracellular space. Because the enzymes in the biosensor break down the analyte, a density gradient is set up resulting in a significantly lower concentration of analyte near the biosensor surface. This effect is compounded by the diminished volume fraction (porosity) and reduction in the diffusion coefficient due to obstructions (tortuosity) in tissue. We demonstrate this effect through modeling and experimentally verify our predictions in diffusive environments. NEW & NOTEWORTHY Microelectrode biosensors are typically calibrated in a free-flow environment where the concentrations at the biosensor surface are constant. However, when in tissue, the analyte reaches the biosensor via diffusion and so analyte breakdown by the biosensor results in a concentration gradient and consequently a lower concentration around the biosensor. This effect means that naive free-flow calibration will underestimate tissue concentration. We develop mathematical models to better quantify the discrepancy between the calibration and tissue

  4. How and why DNA barcodes underestimate the diversity of microbial eukaryotes.

    Directory of Open Access Journals (Sweden)

    Gwenael Piganeau

    Full Text Available BACKGROUND: Because many picoplanktonic eukaryotic species cannot currently be maintained in culture, direct sequencing of PCR-amplified 18S ribosomal gene DNA fragments from filtered sea-water has been successfully used to investigate the astounding diversity of these organisms. The recognition of many novel planktonic organisms is thus based solely on their 18S rDNA sequence. However, a species delimited by its 18S rDNA sequence might contain many cryptic species, which are highly differentiated in their protein coding sequences. PRINCIPAL FINDINGS: Here, we investigate the issue of species identification from one gene to the whole genome sequence. Using 52 whole genome DNA sequences, we estimated the global genetic divergence in protein coding genes between organisms from different lineages and compared this to their ribosomal gene sequence divergences. We show that this relationship between proteome divergence and 18S divergence is lineage dependent. Unicellular lineages have especially low 18S divergences relative to their protein sequence divergences, suggesting that 18S ribosomal genes are too conservative to assess planktonic eukaryotic diversity. We provide an explanation for this lineage dependency, which suggests that most species with large effective population sizes will show far less divergence in 18S than protein coding sequences. CONCLUSIONS: There is therefore a trade-off between using genes that are easy to amplify in all species, but which by their nature are highly conserved and underestimate the true number of species, and using genes that give a better description of the number of species, but which are more difficult to amplify. We have shown that this trade-off differs between unicellular and multicellular organisms as a likely consequence of differences in effective population sizes. We anticipate that biodiversity of microbial eukaryotic species is underestimated and that numerous "cryptic species" will become

  5. Low modeled ozone production suggests underestimation of precursor emissions (especially NOx in Europe

    Directory of Open Access Journals (Sweden)

    E. Oikonomakis

    2018-02-01

    Full Text Available High surface ozone concentrations, which usually occur when photochemical ozone production takes place, pose a great risk to human health and vegetation. Air quality models are often used by policy makers as tools for the development of ozone mitigation strategies. However, the modeled ozone production is often not or not enough evaluated in many ozone modeling studies. The focus of this work is to evaluate the modeled ozone production in Europe indirectly, with the use of the ozone–temperature correlation for the summer of 2010 and to analyze its sensitivity to precursor emissions and meteorology by using the regional air quality model, the Comprehensive Air Quality Model with Extensions (CAMx. The results show that the model significantly underestimates the observed high afternoon surface ozone mixing ratios (≥  60 ppb by 10–20 ppb and overestimates the lower ones (<  40 ppb by 5–15 ppb, resulting in a misleading good agreement with the observations for average ozone. The model also underestimates the ozone–temperature regression slope by about a factor of 2 for most of the measurement stations. To investigate the impact of emissions, four scenarios were tested: (i increased volatile organic compound (VOC emissions by a factor of 1.5 and 2 for the anthropogenic and biogenic VOC emissions, respectively, (ii increased nitrogen oxide (NOx emissions by a factor of 2, (iii a combination of the first two scenarios and (iv increased traffic-only NOx emissions by a factor of 4. For southern, eastern, and central (except the Benelux area Europe, doubling NOx emissions seems to be the most efficient scenario to reduce the underestimation of the observed high ozone mixing ratios without significant degradation of the model performance for the lower ozone mixing ratios. The model performance for ozone–temperature correlation is also better when NOx emissions are doubled. In the Benelux area, however, the third scenario

  6. MDCT of retractor-related hepatic injury following laparoscopic surgery: Appearances, incidence, and follow-up

    International Nuclear Information System (INIS)

    Orr, K.E.; Williams, M.P.

    2014-01-01

    Aims: To investigate the postoperative computed tomography (CT) features resulting from the use of Nathanson retractors during laparoscopic upper gastro-intestinal surgery. Materials and methods: A 3-year retrospective study of 176 patients who had undergone laparoscopic upper gastro-intestinal surgery for bariatric or malignant disease was performed. Postoperative CT images [divided into early (≤30 days) and late (>30 days)] were assessed by a consultant radiologist and liver abnormalities recorded. Results: The features of a retractor injury were a hypodense lesion, abutting the liver edge, usually triangular or linear in shape. Late postoperative features included focal subcapsular retraction and associated liver atrophy. Sixty-eight percent (52/77) of patients undergoing surgery for malignancy underwent postoperative CT, compared with 11% (11/99) of those undergoing bariatric surgery. Patients with malignancy were more likely to have retraction-related liver abnormalities (14/52, 27%) at postoperative CT than those in the bariatric group (2/11, 18%). Conclusion: Retractor-related liver injuries at MDCT are common following laparoscopic upper gastro-intestinal surgery. Recognition of the characteristic triad of features, a hypodense lesion abutting the liver edge with a triangular or linear shape, should allow confident diagnosis. CT follow-up reveals that over time these lesions may disappear, remain unchanged, or result in a focal subcapsular scar with associated atrophy. - Highlights: • Large numbers of patients undergo post-op CT after upper GI laparoscopic surgery. • Retractor injuries are common in the 30 days after laparoscopic upper GI surgery. • Characteristic features are hypodense, triangular/linear lesions at the liver edge

  7. Perfusion CT of the Brain and Liver and of Lung Tumors: Use of Monte Carlo Simulation for Patient Dose Estimation for Examinations With a Cone-Beam 320-MDCT Scanner.

    Science.gov (United States)

    Cros, Maria; Geleijns, Jacob; Joemai, Raoul M S; Salvadó, Marçal

    2016-01-01

    The purpose of this study was to estimate the patient dose from perfusion CT examinations of the brain, lung tumors, and the liver on a cone-beam 320-MDCT scanner using a Monte Carlo simulation and the recommendations of the International Commission on Radiological Protection (ICRP). A Monte Carlo simulation based on the Electron Gamma Shower Version 4 package code was used to calculate organ doses and the effective dose in the reference computational phantoms for an adult man and adult woman as published by the ICRP. Three perfusion CT acquisition protocols--brain, lung tumor, and liver perfusion--were evaluated. Additionally, dose assessments were performed for the skin and for the eye lens. Conversion factors were obtained to estimate effective doses and organ doses from the volume CT dose index and dose-length product. The sex-averaged effective doses were approximately 4 mSv for perfusion CT of the brain and were between 23 and 26 mSv for the perfusion CT body protocols. The eye lens dose from the brain perfusion CT examination was approximately 153 mGy. The sex-averaged peak entrance skin dose (ESD) was 255 mGy for the brain perfusion CT studies, 157 mGy for the lung tumor perfusion CT studies, and 172 mGy for the liver perfusion CT studies. The perfusion CT protocols for imaging the brain, lung tumors, and the liver performed on a 320-MDCT scanner yielded patient doses that are safely below the threshold doses for deterministic effects. The eye lens dose, peak ESD, and effective doses can be estimated for other clinical perfusion CT examinations from the conversion factors that were derived in this study.

  8. Drastic underestimation of amphipod biodiversity in the endangered Irano-Anatolian and Caucasus biodiversity hotspots.

    Science.gov (United States)

    Katouzian, Ahmad-Reza; Sari, Alireza; Macher, Jan N; Weiss, Martina; Saboori, Alireza; Leese, Florian; Weigand, Alexander M

    2016-03-01

    Biodiversity hotspots are centers of biological diversity and particularly threatened by anthropogenic activities. Their true magnitude of species diversity and endemism, however, is still largely unknown as species diversity is traditionally assessed using morphological descriptions only, thereby ignoring cryptic species. This directly limits evidence-based monitoring and management strategies. Here we used molecular species delimitation methods to quantify cryptic diversity of the montane amphipods in the Irano-Anatolian and Caucasus biodiversity hotspots. Amphipods are ecosystem engineers in rivers and lakes. Species diversity was assessed by analysing two genetic markers (mitochondrial COI and nuclear 28S rDNA), compared with morphological assignments. Our results unambiguously demonstrate that species diversity and endemism is dramatically underestimated, with 42 genetically identified freshwater species in only five reported morphospecies. Over 90% of the newly recovered species cluster inside Gammarus komareki and G. lacustris; 69% of the recovered species comprise narrow range endemics. Amphipod biodiversity is drastically underestimated for the studied regions. Thus, the risk of biodiversity loss is significantly greater than currently inferred as most endangered species remain unrecognized and/or are only found locally. Integrative application of genetic assessments in monitoring programs will help to understand the true magnitude of biodiversity and accurately evaluate its threat status.

  9. Underestimating the Toxicological Challenges Associated with the Use of Herbal Medicinal Products in Developing Countries

    Directory of Open Access Journals (Sweden)

    Vidushi S. Neergheen-Bhujun

    2013-01-01

    Full Text Available Various reports suggest a high contemporaneous prevalence of herb-drug use in both developed and developing countries. The World Health Organisation indicates that 80% of the Asian and African populations rely on traditional medicine as the primary method for their health care needs. Since time immemorial and despite the beneficial and traditional roles of herbs in different communities, the toxicity and herb-drug interactions that emanate from this practice have led to severe adverse effects and fatalities. As a result of the perception that herbal medicinal products have low risk, consumers usually disregard any association between their use and any adverse reactions hence leading to underreporting of adverse reactions. This is particularly common in developing countries and has led to a paucity of scientific data regarding the toxicity and interactions of locally used traditional herbal medicine. Other factors like general lack of compositional and toxicological information of herbs and poor quality of adverse reaction case reports present hurdles which are highly underestimated by the population in the developing world. This review paper addresses these toxicological challenges and calls for natural health product regulations as well as for protocols and guidance documents on safety and toxicity testing of herbal medicinal products.

  10. Underestimating the toxicological challenges associated with the use of herbal medicinal products in developing countries.

    Science.gov (United States)

    Neergheen-Bhujun, Vidushi S

    2013-01-01

    Various reports suggest a high contemporaneous prevalence of herb-drug use in both developed and developing countries. The World Health Organisation indicates that 80% of the Asian and African populations rely on traditional medicine as the primary method for their health care needs. Since time immemorial and despite the beneficial and traditional roles of herbs in different communities, the toxicity and herb-drug interactions that emanate from this practice have led to severe adverse effects and fatalities. As a result of the perception that herbal medicinal products have low risk, consumers usually disregard any association between their use and any adverse reactions hence leading to underreporting of adverse reactions. This is particularly common in developing countries and has led to a paucity of scientific data regarding the toxicity and interactions of locally used traditional herbal medicine. Other factors like general lack of compositional and toxicological information of herbs and poor quality of adverse reaction case reports present hurdles which are highly underestimated by the population in the developing world. This review paper addresses these toxicological challenges and calls for natural health product regulations as well as for protocols and guidance documents on safety and toxicity testing of herbal medicinal products.

  11. Underestimation of weight and its associated factors in overweight and obese university students from 21 low, middle and emerging economy countries.

    Science.gov (United States)

    Peltzer, Karl; Pengpid, Supa

    2015-01-01

    Awareness of overweight status is an important factor of weight control and may have more impact on one's decision to lose weight than objective weight status. The purpose of this study was to assess the prevalence of underestimation of overweight/obesity and its associated factors among university students from 21 low, middle and emerging economy countries. In a cross-sectional survey the total sample included 15,068 undergraduate university students (mean age 20.8, SD=2.8, age range of 16-30 years) from 21 countries. Anthropometric measurements and self-administrated questionnaire were applied to collected data. The prevalence of weight underestimation (being normal or underweight) for overweight or obese university students was 33.3% (41% in men and 25.1% in women), among overweight students, 39% felt they had normal weight or were under weight, and among obese students 67% did not rate themselves as obese or very overweight. In multivariate logistic regression analysis, being male, poor subjective health status, lack of overweight health risk awareness, lack of importance to lose weight, not trying and not dieting to lose weight, and regular breakfast was associated with underestimation of weight in overweight and obese university students. The study found a high prevalence of underestimation of overweight/obesity among university students. Several factors identified can be utilized in health promotion programmes including diet and weight management behaviours to focus on inaccurate weight perceptions on the design of weight control, in particular for men. Copyright © 2014 Asian Oceanian Association for the Study of Obesity. Published by Elsevier Ltd. All rights reserved.

  12. A multiscale MDCT image-based breathing lung model with time-varying regional ventilation

    Science.gov (United States)

    Yin, Youbing; Choi, Jiwoong; Hoffman, Eric A.; Tawhai, Merryn H.; Lin, Ching-Long

    2012-01-01

    A novel algorithm is presented that links local structural variables (regional ventilation and deforming central airways) to global function (total lung volume) in the lung over three imaged lung volumes, to derive a breathing lung model for computational fluid dynamics simulation. The algorithm constitutes the core of an integrative, image-based computational framework for subject-specific simulation of the breathing lung. For the first time, the algorithm is applied to three multi-detector row computed tomography (MDCT) volumetric lung images of the same individual. A key technique in linking global and local variables over multiple images is an in-house mass-preserving image registration method. Throughout breathing cycles, cubic interpolation is employed to ensure C1 continuity in constructing time-varying regional ventilation at the whole lung level, flow rate fractions exiting the terminal airways, and airway deformation. The imaged exit airway flow rate fractions are derived from regional ventilation with the aid of a three-dimensional (3D) and one-dimensional (1D) coupled airway tree that connects the airways to the alveolar tissue. An in-house parallel large-eddy simulation (LES) technique is adopted to capture turbulent-transitional-laminar flows in both normal and deep breathing conditions. The results obtained by the proposed algorithm when using three lung volume images are compared with those using only one or two volume images. The three-volume-based lung model produces physiologically-consistent time-varying pressure and ventilation distribution. The one-volume-based lung model under-predicts pressure drop and yields un-physiological lobar ventilation. The two-volume-based model can account for airway deformation and non-uniform regional ventilation to some extent, but does not capture the non-linear features of the lung. PMID:23794749

  13. A multiscale MDCT image-based breathing lung model with time-varying regional ventilation

    Energy Technology Data Exchange (ETDEWEB)

    Yin, Youbing, E-mail: youbing-yin@uiowa.edu [Department of Mechanical and Industrial Engineering, The University of Iowa, Iowa City, IA 52242 (United States); IIHR-Hydroscience and Engineering, The University of Iowa, Iowa City, IA 52242 (United States); Department of Radiology, The University of Iowa, Iowa City, IA 52242 (United States); Choi, Jiwoong, E-mail: jiwoong-choi@uiowa.edu [Department of Mechanical and Industrial Engineering, The University of Iowa, Iowa City, IA 52242 (United States); IIHR-Hydroscience and Engineering, The University of Iowa, Iowa City, IA 52242 (United States); Hoffman, Eric A., E-mail: eric-hoffman@uiowa.edu [Department of Radiology, The University of Iowa, Iowa City, IA 52242 (United States); Department of Biomedical Engineering, The University of Iowa, Iowa City, IA 52242 (United States); Department of Internal Medicine, The University of Iowa, Iowa City, IA 52242 (United States); Tawhai, Merryn H., E-mail: m.tawhai@auckland.ac.nz [Auckland Bioengineering Institute, The University of Auckland, Auckland (New Zealand); Lin, Ching-Long, E-mail: ching-long-lin@uiowa.edu [Department of Mechanical and Industrial Engineering, The University of Iowa, Iowa City, IA 52242 (United States); IIHR-Hydroscience and Engineering, The University of Iowa, Iowa City, IA 52242 (United States)

    2013-07-01

    A novel algorithm is presented that links local structural variables (regional ventilation and deforming central airways) to global function (total lung volume) in the lung over three imaged lung volumes, to derive a breathing lung model for computational fluid dynamics simulation. The algorithm constitutes the core of an integrative, image-based computational framework for subject-specific simulation of the breathing lung. For the first time, the algorithm is applied to three multi-detector row computed tomography (MDCT) volumetric lung images of the same individual. A key technique in linking global and local variables over multiple images is an in-house mass-preserving image registration method. Throughout breathing cycles, cubic interpolation is employed to ensure C{sub 1} continuity in constructing time-varying regional ventilation at the whole lung level, flow rate fractions exiting the terminal airways, and airway deformation. The imaged exit airway flow rate fractions are derived from regional ventilation with the aid of a three-dimensional (3D) and one-dimensional (1D) coupled airway tree that connects the airways to the alveolar tissue. An in-house parallel large-eddy simulation (LES) technique is adopted to capture turbulent-transitional-laminar flows in both normal and deep breathing conditions. The results obtained by the proposed algorithm when using three lung volume images are compared with those using only one or two volume images. The three-volume-based lung model produces physiologically-consistent time-varying pressure and ventilation distribution. The one-volume-based lung model under-predicts pressure drop and yields un-physiological lobar ventilation. The two-volume-based model can account for airway deformation and non-uniform regional ventilation to some extent, but does not capture the non-linear features of the lung.

  14. Role of enhanced multi-detector-row computed tomography before urgent endoscopy in acute upper gastrointestinal bleeding.

    Science.gov (United States)

    Miyaoka, Youichi; Amano, Yuji; Ueno, Sayaka; Izumi, Daisuke; Mikami, Hironobu; Yazaki, Tomotaka; Okimoto, Eiko; Sonoyama, Takayuki; Ito, Satoko; Fujishiro, Hirofumi; Kohge, Naruaki; Imaoka, Tomonori

    2014-04-01

    Multi-detector-row computed tomography (MDCT) has been reported to be a potentially useful modality for detection of the bleeding origin in patients with acute upper massive gastrointestinal (GI) bleeding. The purpose of this study is to investigate the efficacy of MDCT as a routine method for detecting the origin of acute upper GI bleeding prior to urgent endoscopy. Five hundred seventy-seven patients with acute upper GI bleeding (514 nonvariceal patients, 63 variceal patients) who underwent urgent upper GI endoscopy were retrospectively analyzed. Patients were divided into three groups: enhanced MDCT, unenhanced MDCT, and no MDCT before endoscopy. The diagnostic accuracy of MDCT for detection of the bleeding origin was evaluated, and the average procedure times needed to endoscopically identify the bleeding origin were compared between groups. Diagnostic accuracy among endoscopists was 55.3% and 14.7% for the enhanced MDCT and unenhanced MDCT groups, respectively. Among nonvariceal patients, accuracy was 50.2% in the enhanced MDCT group, which was significantly better than that in the unenhanced MDCT group (16.5%). In variceal patients, accuracy was significantly better in the enhanced MDCT group (96.4%) than in the unenhanced MDCT group (0.0%). These accuracies were similar to those achieved by expert radiologists. The average procedure time to endoscopic detection of the bleeding origin in the enhanced MDCT group was significantly faster than that in the unenhanced MDCT and no-MDCT groups. Enhanced MDCT preceding urgent endoscopy may be an effective modality for the detection of bleeding origin in patients with acute upper GI bleeding. © 2013 Journal of Gastroenterology and Hepatology Foundation and Wiley Publishing Asia Pty Ltd.

  15. A Large Underestimate of Formic Acid from Tropical Fires: Constraints from Space-Borne Measurements.

    Science.gov (United States)

    Chaliyakunnel, S; Millet, D B; Wells, K C; Cady-Pereira, K E; Shephard, M W

    2016-06-07

    Formic acid (HCOOH) is one of the most abundant carboxylic acids and a dominant source of atmospheric acidity. Recent work indicates a major gap in the HCOOH budget, with atmospheric concentrations much larger than expected from known sources. Here, we employ recent space-based observations from the Tropospheric Emission Spectrometer with the GEOS-Chem atmospheric model to better quantify the HCOOH source from biomass burning, and assess whether fire emissions can help close the large budget gap for this species. The space-based data reveal a severe model HCOOH underestimate most prominent over tropical burning regions, suggesting a major missing source of organic acids from fires. We develop an approach for inferring the fractional fire contribution to ambient HCOOH and find, based on measurements over Africa, that pyrogenic HCOOH:CO enhancement ratios are much higher than expected from direct emissions alone, revealing substantial secondary organic acid production in fire plumes. Current models strongly underestimate (by 10 ± 5 times) the total primary and secondary HCOOH source from African fires. If a 10-fold bias were to extend to fires in other regions, biomass burning could produce 14 Tg/a of HCOOH in the tropics or 16 Tg/a worldwide. However, even such an increase would only represent 15-20% of the total required HCOOH source, implying the existence of other larger missing sources.

  16. Are We Underestimating Microplastic Contamination in Aquatic Environments?

    Science.gov (United States)

    Conkle, Jeremy L.; Báez Del Valle, Christian D.; Turner, Jeffrey W.

    2018-01-01

    Plastic debris, specifically microplastic in the aquatic environment, is an escalating environmental crisis. Efforts at national scales to reduce or ban microplastics in personal care products are starting to pay off, but this will not affect those materials already in the environment or those that result from unregulated products and materials. To better inform future microplastic research and mitigation efforts this study (1) evaluates methods currently used to quantify microplastics in the environment and (2) characterizes the concentration and size distribution of microplastics in a variety of products. In this study, 50 published aquatic surveys were reviewed and they demonstrated that most ( 80%) only account for plastics ≥ 300 μm in diameter. In addition, we surveyed 770 personal care products to determine the occurrence, concentration and size distribution of polyethylene microbeads. Particle concentrations ranged from 1.9 to 71.9 mg g-1 of product or 1649 to 31,266 particles g-1 of product. The large majority ( > 95%) of particles in products surveyed were less than the 300 μm minimum diameter, indicating that previous environmental surveys could be underestimating microplastic contamination. To account for smaller particles as well as microfibers from synthetic textiles, we strongly recommend that future surveys consider methods that materials < 300 μm in diameter.

  17. Evaluation of left ventricular function and volume with multidetector-row computed tomography. Comparison with electrocardiogram-gated single photon emission computed tomography

    International Nuclear Information System (INIS)

    Suzuki, Takeya; Yamashina, Shohei; Nanjou, Shuji; Yamazaki, Junichi

    2007-01-01

    This study compared left ventricular systolic function and volume determined by multidetector-row computed tomography (MDCT) and electrocardiogram-gated single photon emission computed tomography (G-SPECT) Thirty-seven patients with coronary artery disease and non-cardiovascular disease underwent MDCT. In this study, left ventricular ejection fraction (EF), left ventricular end-diastolic volume (EDV) and left ventricular end-systolic volume (ESV) were calculated using only two-phase imaging with MDCT. Left ventricular function and volume were compared using measurements from G-SPECT. We conducted MDCT and G-SPECT virtually simultaneously. Both the EF and ESV evaluated by MDCT closely correlated with G-SPECT (r=0.763, P 65 bpm) during MDCT significantly influenced the difference in EF calculated from MDCT and G-SPECT (P<0.05). Left ventricular function can be measured with MDCT as well as G-SPECT. However, a heart rate over 65 bpm during MDCT negatively affects the EF correlation between MDCT and G-SPECT. (author)

  18. Dose management as a measurable criteria into the quality control programme of an imaging diagnostic clinic

    International Nuclear Information System (INIS)

    Kirova, G.; Georgiev, E.; Zasheva, C.; Georgiev, S.

    2014-01-01

    In the Radiology Department of Tokuda Hospital Sofia, a strong control over the radiation dose for all patients was accepted with the implementation of the Dose Watch software. The system allows bad practices to be discovered and improves the efficiency and quality of the CT procedures performed in the department. The article will briefly demonstrate the main steps, which have been done, and the results, which have been achieved. The purpose is to identify the challenges, the available tools, and the opportunities for improving the patients' dose in the CT sector of a general Radiology Department. Collected data was based on the information concerning the radiation dose absorbed by individual patients undergoing MDCT examinations in a general radiology department with an overall annual rate of around 7000 MDCT examinations. All of them were carried out using a single 64row MDCT system. The hospital logbook was used to identify the number of CT examinations and dose levels associated with some typical diagnostic procedures in order to make an analysis. The information was taken form the PACS and Dose Watch software and was analyzed. The article draws some measures towards improving the organization and reducing the dose, keeping the quality of the performed exams. Thanks to the supportive software for dose tracking, analyzing and reporting, some problems have been solved and some reasonable measures have been implemented into the daily practice. (authors) Key words: RADIATION DOSE. MDCT. DOSE REDUCTION. REFERRAL GUIDELINES.CTDI. DLP

  19. Non-linear general instability of ring-stiffened conical shells under external hydrostatic pressure

    International Nuclear Information System (INIS)

    Ross, C T F; Kubelt, C; McLaughlin, I; Etheridge, A; Turner, K; Paraskevaides, D; Little, A P F

    2011-01-01

    The paper presents the experimental results for 15 ring-stiffened circular steel conical shells, which failed by non-linear general instability. The results of these investigations were compared with various theoretical analyses, including an ANSYS eigen buckling analysis and another ANSYS analysis; which involved a step-by-step method until collapse; where both material and geometrical nonlinearity were considered. The investigation also involved an analysis using BS5500 (PD 5500), together with the method of Ross of the University of Portsmouth. The ANSYS eigen buckling analysis tended to overestimate the predicted buckling pressures; whereas the ANSYS nonlinear results compared favourably with the experimental results. The PD5500 analysis was very time consuming and tended to grossly underestimate the experimental buckling pressures and in some cases, overestimate them. In contrast to PD5500 and ANSYS, the design charts of Ross of the University of Portsmouth were the easiest of all these methods to use and generally only slightly underestimated the experimental collapse pressures. The ANSYS analyses gave some excellent graphical displays.

  20. Does the surface property of a disposable applanation tonometer account for its underestimation of intraocular pressure when compared with the Goldmann tonometer?

    Science.gov (United States)

    Osborne, Sarah F; Williams, Rachel; Batterbury, Mark; Wong, David

    2007-04-01

    Disposable tonometers are increasingly being adopted partly because of concerns over the transmission of variant Creutzfeldt-Jakob disease and partly for convenience. Recently, we have found one such tonometer (Tonojet by Luneau Ophthalmologie, France) underestimated the intraocular pressure (IOP). We hypothesized that this underestimation was caused by a difference in the surface property of the tonometers. A tensiometer was used to measure the suction force resulting from interfacial tension between a solution of lignocaine and fluorescein and the tonometers. The results showed that the suction force was significantly greater for the Goldmann compared to the Tonojet. The magnitude of this force was too small to account for the difference in IOP measurements. The Tonojet was less hydrophilic than the Goldmann, and the contact angle of the fluid was therefore greater. For a given tear film, less hydrophilic tonometers will tend to have thicker mires, and this may lead to underestimation of the IOP. When such disposable tonometers are used, it is recommended care should be taken to reject readings from thick mires.

  1. Evaluation of the resolving power of different angles in MPR images of 16DAS-MDCT

    International Nuclear Information System (INIS)

    Kimura, Mikio; Usui, Junshi; Nozawa, Takeo

    2007-01-01

    In this study, we evaluated the resolving power of three-dimensional (3D) multiplanar reformation (MPR) images with various angles by using 16 data acquisition system multi detector row computed tomography (16DAS-MDCT). We reconstructed the MPR images using data with a 0.75 mm slice thickness of the axial image in this examination. To evaluate resolving power, we used an original new phantom (RC phantom) that can be positioned at any slice angle in MPR images. We measured the modulation transfer function (MTF) by using the methods of measuring pre-sampling MTF, and used Fourier transform of image data of the square wave chart. The scan condition and image reconstruction condition that were adopted in this study correspond to the condition that we use for three-dimensional computed tomographic angiography(3D-CTA) examination of the head in our hospital. The MTF of MPR images showed minimum values at slice angles in parallel with the axial slice, and showed maximum values at the sagittal slice and coronal slice angles that are parallel to the Z-axis. With an oblique MPR image, MTF did not change with angle changes in the oblique sagittal slice plane, but in the oblique coronal slice plane, MTF increased as the tilt angle increased from the axial plane to the Z plane. As a result, we could evaluate the resolving power of a head 3D image by measuring the MTF of the axial image and sagittal image or the coronal image. (author)

  2. [Evaluation of the resolving power of different angles in MPR images of 16DAS-MDCT].

    Science.gov (United States)

    Kimura, Mikio; Usui, Junshi; Nozawa, Takeo

    2007-03-20

    In this study, we evaluated the resolving power of three-dimensional (3D) multiplanar reformation (MPR) images with various angles by using 16 data acquisition system multi detector row computed tomography (16DAS-MDCT) . We reconstructed the MPR images using data with a 0.75 mm slice thickness of the axial image in this examination. To evaluate resolving power, we used an original new phantom (RC phantom) that can be positioned at any slice angle in MPR images. We measured the modulation transfer function (MTF) by using the methods of measuring pre-sampling MTF, and used Fourier transform of image data of the square wave chart. The scan condition and image reconstruction condition that were adopted in this study correspond to the condition that we use for three-dimensional computed tomographic angiography (3D-CTA) examination of the head in our hospital. The MTF of MPR images showed minimum values at slice angles in parallel with the axial slice, and showed maximum values at the sagittal slice and coronal slice angles that are parallel to the Z-axis. With an oblique MPR image, MTF did not change with angle changes in the oblique sagittal slice plane, but in the oblique coronal slice plane, MTF increased as the tilt angle increased from the axial plane to the Z plane. As a result, we could evaluate the resolving power of a head 3D image by measuring the MTF of the axial image and sagittal image or the coronal image.

  3. Underestimated effects of sediments on enhanced startup performance of biofilm systems for polluted source water pretreatment.

    Science.gov (United States)

    Lv, Zheng-Hui; Wang, Jing; Yang, Guang-Feng; Feng, Li-Juan; Mu, Jun; Zhu, Liang; Xu, Xiang-Yang

    2018-02-01

    In order to evaluate the enhancement mechanisms of enhanced startup performance in biofilm systems for polluted source water pretreatment, three lab-scale reactors with elastic stereo media (ESM) were operated under different enhanced sediment and hydraulic agitation conditions. It is interesting to found the previously underestimated or overlooked effects of sediment on the enhancement of pollutants removal performance and enrichment of functional bacteria in biofilm systems. The maximum NH 4 + -N removal rate of 0.35 mg L -1 h -1 in sediment enhanced condition was 2.19 times of that in control reactor. Sediment contributed to 42.0-56.5% of NH 4 + -N removal and 15.4-41.2% of total nitrogen removal in different reactors under different operation conditions. The enhanced hydraulic agitation with sediment further improved the operation performance and accumulation of functional bacteria. Generally, Proteobacteria (48.9-52.1%), Bacteroidetes (18.9-20.8%) and Actinobacteria (15.7-18.5%) were dominant in both sediment and ESM bioiflm at  phylum level. The potentially functional bacteria found in sediment and ESM biofilm samples with some functional bacteria mainly presented in sediment samples only (e.g., Genera Bacillus and Lactococcus of Firmicutes phylum) may commonly contribute to the removal of nitrogen and organics.

  4. Is hyperthyroidism underestimated in pregnancy and misdiagnosed as hyperemesis gravidarum?

    Science.gov (United States)

    Luetic, Ana Tikvica; Miskovic, Berivoj

    2010-10-01

    Thyroid changes are considered to be normal events that happen as a large maternal multiorganic adjustment to pregnancy. However, hyperthyroidism occurs in pregnancy with clinical presentation similar to hyperemesis gravidarum (HG) and pregnancy itself. Moreover, 10% of women with HG will continue to have symptoms throughout the pregnancy suggesting that the underlying cause might not be elevation of human chorionic gonadotropin in the first trimester. Variable frequency of both hyperthyroidism and HG worldwide might suggest the puzzlement of inclusion criteria for both diagnoses enhanced by the alternation of thyroid hormone levels assessed in normal pregnancy. Increased number of hyperthyroidism among women population without the expected rise in gestational hyperthyroidism encouraged us for creating the hypotheses that hyperthyroidism could be underestimated in normal pregnancy and even misdiagnosed as HG. This hypothesis, if confirmed, might have beneficial clinical implications, such as better detection of hyperthyroidism in pregnancies, application of therapy when needed with the reduction of maternal or fetal consequences. Copyright 2010 Elsevier Ltd. All rights reserved.

  5. Chronic intestinal pseudo-obstruction in adult patients: multidetector row helical CT features

    International Nuclear Information System (INIS)

    Merlin, Aurelie; Soyer, Philippe; Boudiaf, Mourad; Hamzi, Lounis; Rymer, Roland

    2008-01-01

    Chronic intestinal pseudo-obstruction (CIPO) is a rare condition due to severe gastrointestinal motility disorder. Adult patients with CIPO experience symptoms of mechanical obstruction, but reliable clinical signs that may help distinguish between actual mechanical obstruction and CIPO are lacking. Additionally, abdominal plain films that commonly show bowel dilatation with air-fluid levels do not reach acceptable degrees of specificity to exclude actual obstruction. Therefore, most adult patients with CIPO usually undergo multiple and often fruitless surgery, often leading to repeated bowel resections before diagnosis is made. In these patients who present with abdominal signs mimicking symptoms that would warrant surgical exploration, multidetector-row helical CT (MDCT) is helpful to resolve this diagnostic dilemma. MDCT shows a diffusely distended bowel and helps to rule out a mechanical cause of obstruction, thus suggesting CIPO and obviating the need for unnecessary laparotomy. In adult patients with CIPO, MDCT may show pneumatosis intestinalis, pneumoperitoneum or intussusception. However, these conditions generally do not require surgery in patients with CIPO. This pictorial essay presents the more and less common MDCT features of CIPO in adult patients, to make the reader more familiar with this disease. (orig.)

  6. Dose estimation in CT exams of the abdomen based on values of DLP; Estimativa da dose em exames de tomografia de abdome com base nos valores de DLP

    Energy Technology Data Exchange (ETDEWEB)

    Kikuti, C.F.; Medeiros, R.B.; Salvadori, P.S.; Costa, D.M.C; D' lppolito, G., E-mail: kikuticf@gmail.com, E-mail: rbitelli2011@gmail.com [Universidade Federal de Sao Paulo (UNIFESP), SP (Brazil). Coordenadoria de Fisica e Higiene das Radiacoes. Departamento de Diagnostico por Imagem

    2013-10-01

    One of the challenges of multidetector computerized tomography is to minimize the risk of ionizing radiation using optimized protocols since higher doses are necessary to obtain high image quality. It was also noted that, due to the geometry in image acquisition using MDCT becomes necessary to estimate dose values consistent with the hypothesis clinically and with the specificities of the tomographic equipment. The aim of this study was to estimate the doses in abdomen exams from the data recorded on the MDCT console and dimensions obtained from DICOM images of patients undergoing different clinical protocols. Were collected, from the image DICOM of 101 exams, values of the dose length product (DLP) provided by Philips Health Care - Brilliance 64 equipment console, in order to relate them with the dose values obtained by means of thermoluminescent dosimeters ( TLD ) of CasSo{sub 4}:Mn placed on the surface of a cylindrical simulator abdomen acrylic manufactured under the technical - operational conditions for a typical abdomen exam. From the data obtained, it was possible to find a factor of 1.16 ( 5 % ) indicating that the DLP values Brilliance 64 console underestimate the doses and this should be used with correction factor to estimate the total dose of the patient. (author)

  7. Dose estimation in CT exams of the abdomen based on values of DLP

    International Nuclear Information System (INIS)

    Kikuti, C.F.; Medeiros, R.B.; Salvadori, P.S.; Costa, D.M.C; D'lppolito, G.

    2013-01-01

    One of the challenges of multidetector computerized tomography is to minimize the risk of ionizing radiation using optimized protocols since higher doses are necessary to obtain high image quality. It was also noted that, due to the geometry in image acquisition using MDCT becomes necessary to estimate dose values consistent with the hypothesis clinically and with the specificities of the tomographic equipment. The aim of this study was to estimate the doses in abdomen exams from the data recorded on the MDCT console and dimensions obtained from DICOM images of patients undergoing different clinical protocols. Were collected, from the image DICOM of 101 exams, values of the dose length product (DLP) provided by Philips Health Care - Brilliance 64 equipment console, in order to relate them with the dose values obtained by means of thermoluminescent dosimeters ( TLD ) of CasSo 4 :Mn placed on the surface of a cylindrical simulator abdomen acrylic manufactured under the technical - operational conditions for a typical abdomen exam. From the data obtained, it was possible to find a factor of 1.16 ( 5 % ) indicating that the DLP values Brilliance 64 console underestimate the doses and this should be used with correction factor to estimate the total dose of the patient. (author)

  8. Effect of ultra-low doses, ASIR and MBIR on density and noise levels of MDCT images of dental implant sites

    Energy Technology Data Exchange (ETDEWEB)

    Widmann, Gerlig; Schullian, Peter [Medical University of Innsbruck, Department of Radiology, Innsbruck (Austria); Al-Shawaf, Reema; Al-Sadhan, Ra' ed; Al-Ekrish, Asma' a A. [King Saud University, Department of Oral Medicine and Diagnostic Sciences, College of Dentistry, Riyadh (Saudi Arabia); Hoermann, Romed [Medical University of Innsbruck, Division of Clinical and Functional Anatomy, Innsbruck (Austria)

    2017-05-15

    Differences in noise and density values in MDCT images obtained using ultra-low doses with FBP, ASIR, and MBIR may possibly affect implant site density analysis. The aim of this study was to compare density and noise measurements recorded from dental implant sites using ultra-low doses combined with FBP, ASIR, and MBIR. Cadavers were scanned using a standard protocol and four low-dose protocols. Scans were reconstructed using FBP, ASIR-50, ASIR-100, and MBIR, and either a bone or standard reconstruction kernel. Density (mean Hounsfield units [HUs]) of alveolar bone and noise levels (mean standard deviation of HUs) was recorded from all datasets and measurements were compared by paired t tests and two-way ANOVA with repeated measures. Significant differences in density and noise were found between the reference dose/FBP protocol and almost all test combinations. Maximum mean differences in HU were 178.35 (bone kernel) and 273.74 (standard kernel), and in noise, were 243.73 (bone kernel) and 153.88 (standard kernel). Decreasing radiation dose increased density and noise regardless of reconstruction technique and kernel. The effect of reconstruction technique on density and noise depends on the reconstruction kernel used. (orig.)

  9. Effect of ultra-low doses, ASIR and MBIR on density and noise levels of MDCT images of dental implant sites

    International Nuclear Information System (INIS)

    Widmann, Gerlig; Schullian, Peter; Al-Shawaf, Reema; Al-Sadhan, Ra'ed; Al-Ekrish, Asma'a A.; Hoermann, Romed

    2017-01-01

    Differences in noise and density values in MDCT images obtained using ultra-low doses with FBP, ASIR, and MBIR may possibly affect implant site density analysis. The aim of this study was to compare density and noise measurements recorded from dental implant sites using ultra-low doses combined with FBP, ASIR, and MBIR. Cadavers were scanned using a standard protocol and four low-dose protocols. Scans were reconstructed using FBP, ASIR-50, ASIR-100, and MBIR, and either a bone or standard reconstruction kernel. Density (mean Hounsfield units [HUs]) of alveolar bone and noise levels (mean standard deviation of HUs) was recorded from all datasets and measurements were compared by paired t tests and two-way ANOVA with repeated measures. Significant differences in density and noise were found between the reference dose/FBP protocol and almost all test combinations. Maximum mean differences in HU were 178.35 (bone kernel) and 273.74 (standard kernel), and in noise, were 243.73 (bone kernel) and 153.88 (standard kernel). Decreasing radiation dose increased density and noise regardless of reconstruction technique and kernel. The effect of reconstruction technique on density and noise depends on the reconstruction kernel used. (orig.)

  10. Evaluation of a dedicated MDCT protocol using iterative image reconstruction after cervical spine trauma.

    Science.gov (United States)

    Geyer, L L; Körner, M; Hempel, R; Deak, Z; Mueck, F G; Linsenmaier, U; Reiser, M F; Wirth, S

    2013-07-01

    To evaluate radiation exposure for 64-row computed tomography (CT) of the cervical spine comparing two optimized protocols using filtered back projection (FBP) and adaptive statistical iterative reconstruction (ASIR), respectively. Sixty-seven studies using FBP (scanner 1) were retrospectively compared with 80 studies using ASIR (scanner 2). The key scanning parameters were identical (120 kV dose modulation, 64 × 0.625 mm collimation, pitch 0.531:1). In protocol 2, the noise index (NI) was increased from 5 to 25, and ASIR and the high-definition (HD) mode were used. The scan length, CT dose index (CTDI), and dose-length product (DLP) were recorded. The image quality was analysed subjectively by using a three-point scale (0; 1; 2), and objectively by using a region of interest (ROI) analysis. Mann-Whitney U and Wilcoxon's test were used. In the FBP group, the mean CTDI was 21.43 mGy, mean scan length 186.3 mm, and mean DLP 441.15 mGy cm. In the ASIR group, the mean CTDI was 9.57 mGy, mean scan length 195.21 mm, and mean DLP 204.23 mGy cm. The differences were significant for CTDI and DLP (p 0.05). The estimated mean effective dose decreased from 2.38 mSv (FBP) to 1.10 mSv (ASIR). The radiation dose of 64-row MDCT can be reduced to a level comparable to plain radiography without loss of subjective image quality by implementation of ASIR in a dedicated cervical spine trauma protocol. These results might contribute to an improved relative risk-to-benefit ratio and support the justification of CT as a first-line imaging tool to evaluate cervical spine trauma. Copyright © 2013 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.

  11. Evaluation of a dedicated MDCT protocol using iterative image reconstruction after cervical spine trauma

    International Nuclear Information System (INIS)

    Geyer, L.L.; Körner, M.; Hempel, R.; Deak, Z.; Mueck, F.G.; Linsenmaier, U.; Reiser, M.F.; Wirth, S.

    2013-01-01

    Aim: To evaluate radiation exposure for 64-row computed tomography (CT) of the cervical spine comparing two optimized protocols using filtered back projection (FBP) and adaptive statistical iterative reconstruction (ASIR), respectively. Materials and methods: Sixty-seven studies using FBP (scanner 1) were retrospectively compared with 80 studies using ASIR (scanner 2). The key scanning parameters were identical (120 kV dose modulation, 64 × 0.625 mm collimation, pitch 0.531:1). In protocol 2, the noise index (NI) was increased from 5 to 25, and ASIR and the high-definition (HD) mode were used. The scan length, CT dose index (CTDI), and dose–length product (DLP) were recorded. The image quality was analysed subjectively by using a three-point scale (0; 1; 2), and objectively by using a region of interest (ROI) analysis. Mann–Whitney U and Wilcoxon's test were used. Results: In the FBP group, the mean CTDI was 21.43 mGy, mean scan length 186.3 mm, and mean DLP 441.15 mGy cm. In the ASIR group, the mean CTDI was 9.57 mGy, mean scan length 195.21 mm, and mean DLP 204.23 mGy cm. The differences were significant for CTDI and DLP (p 0.05). The estimated mean effective dose decreased from 2.38 mSv (FBP) to 1.10 mSv (ASIR). Conclusion: The radiation dose of 64-row MDCT can be reduced to a level comparable to plain radiography without loss of subjective image quality by implementation of ASIR in a dedicated cervical spine trauma protocol. These results might contribute to an improved relative risk-to-benefit ratio and support the justification of CT as a first-line imaging tool to evaluate cervical spine trauma

  12. Quantitative analysis of emphysema in 3D using MDCT: Influence of different reconstruction algorithms

    International Nuclear Information System (INIS)

    Ley-Zaporozhan, Julia; Ley, Sebastian; Weinheimer, Oliver; Iliyushenko, Svitlana; Erdugan, Serap; Eberhardt, Ralf; Fuxa, Adelheid; Mews, Juergen; Kauczor, Hans-Ulrich

    2008-01-01

    Purpose: The aim of the study was to compare the influence of different reconstruction algorithms on quantitative emphysema analysis in patients with severe emphysema. Material and methods: Twenty-five patients suffering from severe emphysema were included in the study. All patients underwent inspiratory MDCT (Aquilion-16, slice thickness 1/0.8 mm). The raw data were reconstructed using six different algorithms: bone kernel with beam hardening correction (BHC), soft tissue kernel with BHC; standard soft tissue kernel, smooth soft tissue kernel (internal reference standard), standard lung kernel, and high-convolution kernel. The only difference between image data sets was the algorithm employed to reconstruct the raw data, no additional radiation was required. CT data were analysed using self-written emphysema detection and quantification software providing lung volume, emphysema volume (EV), emphysema index (EI) and mean lung density (MLD). Results: The use of kernels with BHC led to a significant decrease in MLD (5%) and EI (61-79%) in comparison with kernels without BHC. The absolute difference (from smooth soft tissue kernel) in MLD ranged from -0.6 to -6.1 HU and were significant different for all kernels. The EV showed absolute differences between -0.05 and -0.4 L and was significantly different for all kernels. The EI showed absolute differences between -0.8 and -5.1 and was significantly different for all kernels. Conclusion: The use of kernels with BHC led to a significant decrease in MLD and EI. The absolute differences between different kernels without BHC were small but they were larger than the known interscan variation in patients. Thus, for follow-up examinations the same reconstruction algorithm has to be used and use of BHC has to be avoided

  13. Tomographic diagnosis and relevant aspects of otosclerosis

    International Nuclear Information System (INIS)

    Gaiotti, Juliana Oggioni; Gomes, Natalia Delage; Costa, Ana Maria Doffemond; Villela, Caroline Laurita Batista Couto; Moreira, Wanderval; Diniz, Renata Lopes Furletti Caldeira

    2013-01-01

    A literature review and pictorial essay were developed to discuss the importance of knowing the main findings and locations of otosclerosis at multidetector computed tomography (MDCT). The authors performed a retrospective review of cases of otosclerosis diagnosed in their institution by means of high resolution multidetector computed tomography. Otosclerosis corresponds to otic capsule dysplasia characterized by metabolic derangement of its endochondral layer. Such condition constitutes a relevant cause of sensorineural hearing loss, affecting about 7% to 10% of the general population. The diagnosis is usually clinical, but imaging methods play a significant role in the anatomical detailing, differential diagnosis, surgical planning and evaluation of postoperative complications. Among such methods, the relevance of MDCT is highlighted. Radiologists should be familiar with the MDCT findings of otosclerosis, as well as with the temporal bone anatomy to assist in the appropriate clinical management of this disease. (author)

  14. Tomographic diagnosis and relevant aspects of otosclerosis

    Energy Technology Data Exchange (ETDEWEB)

    Gaiotti, Juliana Oggioni; Gomes, Natalia Delage; Costa, Ana Maria Doffemond; Villela, Caroline Laurita Batista Couto; Moreira, Wanderval; Diniz, Renata Lopes Furletti Caldeira, E-mail: jugaiotti@gmail.com [Hospital Mater Dei-Mater Imagem, Belo Horizonte, MG (Brazil)

    2013-09-15

    A literature review and pictorial essay were developed to discuss the importance of knowing the main findings and locations of otosclerosis at multidetector computed tomography (MDCT). The authors performed a retrospective review of cases of otosclerosis diagnosed in their institution by means of high resolution multidetector computed tomography. Otosclerosis corresponds to otic capsule dysplasia characterized by metabolic derangement of its endochondral layer. Such condition constitutes a relevant cause of sensorineural hearing loss, affecting about 7% to 10% of the general population. The diagnosis is usually clinical, but imaging methods play a significant role in the anatomical detailing, differential diagnosis, surgical planning and evaluation of postoperative complications. Among such methods, the relevance of MDCT is highlighted. Radiologists should be familiar with the MDCT findings of otosclerosis, as well as with the temporal bone anatomy to assist in the appropriate clinical management of this disease. (author)

  15. Efficient trawl avoidance by mesopelagic fishes causes large underestimation of their biomass

    KAUST Repository

    Kaartvedt, Stein

    2012-06-07

    Mesopelagic fishes occur in all the world’s oceans, but their abundance and consequently their ecological significance remains uncertain. The current global estimate based on net sampling prior to 1980 suggests a global abundance of one gigatonne (109 t) wet weight. Here we report novel evidence of efficient avoidance of such sampling by the most common myctophid fish in the Northern Atlantic, i.e. Benthosema glaciale. We reason that similar avoidance of nets may explain consistently higher acoustic abundance estimates of mesopelagic fish from different parts of the world’s oceans. It appears that mesopelagic fish abundance may be underestimated by one order of magnitude, suggesting that the role of mesopelagic fish in the oceans might need to be revised.

  16. Multidetector computed tomography virtual hysterosalpingography in the investigation of the uterus and fallopian tubes

    International Nuclear Information System (INIS)

    Carrascosa, Patricia; Baronio, Mariano; Capunay, Carlos; Lopez, Elba Martin; Vallejos, Javier; Borghi, Mario; Sueldo, Carlos; Papier, Sergio

    2008-01-01

    Objective: To compare the efficacy of multidetector CT virtual hysterosalpingography (MDCT-VH) with conventional X-ray hysterosalpingography (HSG) in the evaluation of patients with diagnosis of infertility. Methods: Sixty patients with diagnosis of infertility scheduled to perform a HSG, were evaluated with 16-row (n = 50) and 64-row (n = 10) MDCT-VH. In 35 patients the examination was performed without a tenaculum. The HSGs were carried out using standard technique. The HSG and MDCT-VH findings were compared. The duration for both examinations and patient discomfort were documented. The sensitivity and specificity of MDCT-VH for the detection of uterine pathology and tubal obstruction were calculated using the exact binomial method. Agreement between the two methods was assessed by the Cohen's kappa method (k). Results: The mean duration for MDCT-VH (16 and 64-rows) was 5 ± 3 min, whereas for HSG was 28 ± 3. The MDCT-VH without a tenaculum was the procedure with less patient discomfort. Sensitivity, specificity and inter-method agreement for the detection of uterine pathology were 100%, 92% and k = 0.92 for 16-row MDCT-VH and 100%, 100% and k = 1 for 64-row MDCT-VH, respectively. Sensitivity and specificity for detection of tubal obstruction were 80% and 80% for 16-row MDCT-VH and 100% and 100% for 64-row MDCT-VH, respectively; inter-method agreement for the visualization of the tubes was k = 0.54 for 16-row MDCT-VH and k = 1 for 64-row MDCT-VH. Conclusion: This study demonstrated the feasibility of evaluating the female reproductive system by MDCT-VH. 64-Row MDCT-VH could be an alternative diagnostic technique in the infertility workup algorithm. A larger study is in progress to validate these encouraging results

  17. Multidetector computed tomography virtual hysterosalpingography in the investigation of the uterus and fallopian tubes

    Energy Technology Data Exchange (ETDEWEB)

    Carrascosa, Patricia [Diagnostico Maipu, Av. Maipu 1668, Vicente Lopez B1602ABQ, Buenos Aires (Argentina)], E-mail: patriciacarrascosa@diagnosticomaipu.com.ar; Baronio, Mariano [CEGYR, Viamonte 1438, Capital Federal C1055ABB (Argentina); Capunay, Carlos; Lopez, Elba Martin; Vallejos, Javier [Diagnostico Maipu, Av. Maipu 1668, Vicente Lopez B1602ABQ, Buenos Aires (Argentina); Borghi, Mario; Sueldo, Carlos; Papier, Sergio [CEGYR, Viamonte 1438, Capital Federal C1055ABB (Argentina)

    2008-09-15

    Objective: To compare the efficacy of multidetector CT virtual hysterosalpingography (MDCT-VH) with conventional X-ray hysterosalpingography (HSG) in the evaluation of patients with diagnosis of infertility. Methods: Sixty patients with diagnosis of infertility scheduled to perform a HSG, were evaluated with 16-row (n = 50) and 64-row (n = 10) MDCT-VH. In 35 patients the examination was performed without a tenaculum. The HSGs were carried out using standard technique. The HSG and MDCT-VH findings were compared. The duration for both examinations and patient discomfort were documented. The sensitivity and specificity of MDCT-VH for the detection of uterine pathology and tubal obstruction were calculated using the exact binomial method. Agreement between the two methods was assessed by the Cohen's kappa method (k). Results: The mean duration for MDCT-VH (16 and 64-rows) was 5 {+-} 3 min, whereas for HSG was 28 {+-} 3. The MDCT-VH without a tenaculum was the procedure with less patient discomfort. Sensitivity, specificity and inter-method agreement for the detection of uterine pathology were 100%, 92% and k = 0.92 for 16-row MDCT-VH and 100%, 100% and k = 1 for 64-row MDCT-VH, respectively. Sensitivity and specificity for detection of tubal obstruction were 80% and 80% for 16-row MDCT-VH and 100% and 100% for 64-row MDCT-VH, respectively; inter-method agreement for the visualization of the tubes was k = 0.54 for 16-row MDCT-VH and k = 1 for 64-row MDCT-VH. Conclusion: This study demonstrated the feasibility of evaluating the female reproductive system by MDCT-VH. 64-Row MDCT-VH could be an alternative diagnostic technique in the infertility workup algorithm. A larger study is in progress to validate these encouraging results.

  18. Detection of osseous metastases of the spine: Comparison of high resolution multi-detector-CT with MRI

    International Nuclear Information System (INIS)

    Buhmann, Sonja; Becker, Christoph; Duerr, Hans Roland; Reiser, Maximilian; Baur-Melnyk, Andrea

    2009-01-01

    Purpose: The aim of the study was to evaluate the diagnostic accuracy of multi-slice-computed tomography (MDCT) for the detection of vertebral metastases in comparison to magnetic resonance imaging (MRI). Materials and methods: In a retrospective analysis, 639 vertebral bodies of 41 patients with various histologically confirmed primary malignancies were analysed. The MDCT-images were acquired on a 16/64-row-MDCT scanner (Siemens Somatom Sensation 16/64). MRI was performed on 1.5 T scanners (SIEMENS Symphony/Sonata). The MDCT- and MRI-images were evaluated separately by two experienced radiologists in a consensus reading. The combination of MDCT and MRI in an expert reading including follow-up examinations and/or histology as well as clinical data served as the gold standard. Results: 201/639 vertebral bodies were defined as metastatically affected by the gold standard. In MDCT 133/201 lesions, in MRI 198/201 lesions were detected. 68 vertebral bodies were false negative in MDCT, whereas 3 false negatives were found in MRI. 3 false positive results were obtained in MDCT, 5 in MRI. Sensitivity was significantly lower for MDCT (66.2%) than for MRI (98.5%) (p < 0.0001). Specificity was not significantly different for both methods (MDCT: 99.3%; MRI: 98.9%). The diagnostic accuracy resulted in 88.8% for MDCT and 98.7% for MRI. Conclusion: Although 16/64-row-MDCT provides excellent image quality and a high spatial resolution in the assessment of bony structures, metastatic lesions without significant bone destruction may be missed. The diagnostic accuracy of MRI proved to be significantly superior to 16/64-row-MDCT for the detection of osseous metastases.

  19. Arterial double-contrast dual-energy MDCT: in-vivo rabbit atherosclerosis with iodinated nanoparticles and gadolinium agents

    Science.gov (United States)

    Carmi, Raz; Kafri, Galit; Altman, Ami; Goshen, Liran; Planer, David; Sosna, Jacob

    2010-03-01

    An in-vivo feasibility study of potentially improved atherosclerosis CT imaging is presented. By administration of two different contrast agents to rabbits with induced atherosclerotic plaques we aim at identifying both soft plaque and vessel lumen simultaneously. Initial injection of iodinated nanoparticle (INP) contrast agent (N1177 - Nanoscan Imaging), two to four hours before scan, leads to its later accumulation in macrophage-rich soft plaque, while a second gadolinium contrast agent (Magnevist) injected immediately prior to the scan blends with the aortic blood. The distinction between the two agents in a single scan is achieved with a double-layer dual-energy MDCT (Philips Healthcare) following material separation analysis using the reconstructed images of the different x-ray spectra. A single contrast agent injection scan, where only INP was injected two hours prior to the scan, was compared to a double-contrast scan taken four hours after INP injection and immediately after gadolinium injection. On the single contrast agent scan we observed along the aorta walls, localized iodine accumulation which can point on INP uptake by atherosclerotic plaque. In the double-contrast scan the gadolinium contributes a clearer depiction of the vessel lumen in addition to the lasting INP presence. The material separation shows a good correlation to the pathologies inferred from the conventional CT images of the two different scans while performing only a single scan prevents miss-registration problems and reduces radiation dose. These results suggest that a double-contrast dual-energy CT may be used for advanced clinical diagnostic applications.

  20. Terrestrial pesticide exposure of amphibians: an underestimated cause of global decline?

    Science.gov (United States)

    Brühl, Carsten A; Schmidt, Thomas; Pieper, Silvia; Alscher, Annika

    2013-01-01

    Amphibians, a class of animals in global decline, are present in agricultural landscapes characterized by agrochemical inputs. Effects of pesticides on terrestrial life stages of amphibians such as juvenile and adult frogs, toads and newts are little understood and a specific risk assessment for pesticide exposure, mandatory for other vertebrate groups, is currently not conducted. We studied the effects of seven pesticide products on juvenile European common frogs (Rana temporaria) in an agricultural overspray scenario. Mortality ranged from 100% after one hour to 40% after seven days at the recommended label rate of currently registered products. The demonstrated toxicity is alarming and a large-scale negative effect of terrestrial pesticide exposure on amphibian populations seems likely. Terrestrial pesticide exposure might be underestimated as a driver of their decline calling for more attention in conservation efforts and the risk assessment procedures in place do not protect this vanishing animal group.

  1. Radiographic Underestimation of In Vivo Cup Coverage Provided by Total Hip Arthroplasty for Dysplasia.

    Science.gov (United States)

    Nie, Yong; Wang, HaoYang; Huang, ZeYu; Shen, Bin; Kraus, Virginia Byers; Zhou, Zongke

    2018-01-01

    The accuracy of using 2-dimensional anteroposterior pelvic radiography to assess acetabular cup coverage among patients with developmental dysplasia of the hip after total hip arthroplasty (THA) remains unclear in retrospective clinical studies. A group of 20 patients with developmental dysplasia of the hip (20 hips) underwent cementless THA. During surgery but after acetabular reconstruction, bone wax was pressed onto the uncovered surface of the acetabular cup. A surface model of the bone wax was generated with 3-dimensional scanning. The percentage of the acetabular cup that was covered by intact host acetabular bone in vivo was calculated with modeling software. Acetabular cup coverage also was determined from a postoperative supine anteroposterior pelvic radiograph. The height of the hip center (distance from the center of the femoral head perpendicular to the inter-teardrop line) also was determined from radiographs. Radiographic cup coverage was a mean of 6.93% (SD, 2.47%) lower than in vivo cup coverage for these 20 patients with developmental dysplasia of the hip (Pcup coverage (Pearson r=0.761, Pcup (P=.001) but not the position of the hip center (high vs normal) was significantly associated with the difference between radiographic and in vivo cup coverage. Two-dimensional radiographically determined cup coverage conservatively reflects in vivo cup coverage and remains an important index (taking 7% underestimation errors and the effect of greater underestimation of larger cup size into account) for assessing the stability of the cup and monitoring for adequate ingrowth of bone. [Orthopedics. 2018; 41(1):e46-e51.]. Copyright 2017, SLACK Incorporated.

  2. Diagnostic assessment of painless microhematuria: prospective study comparing image quality, assessibility and diagnostic certainty of multidetector-row CT and intravenous pyelography within a single examination

    International Nuclear Information System (INIS)

    Boehm, T.; John, H.; Ruedi, C.; Marincek, B.; Wildermuth, S.; Michael, M.

    2005-01-01

    Purpose: The purpose of this study is to prospectively compare intravenous pyelography (IVP) and combined unenhanced and excretory phase multidetector-row CT (MDCT) with respect to image quality, diagnostic certainty and diagnostic concordance with the final clinical diagnosis in patients with painless microhematuria. Materials and Methods: Unenhanced MDCT, IVP and excretory phase MDCT were performed in 59 consecutive patients (21 women, 38 men, mean age 56±19 years, range 23-83 years) with painless microhematuria of unknown origin during a single examination with a single contrast media application (100 ml, non-ionic iodinate contrast media). Images were assessed by two experienced urogenital radiologists in consensus for image quality, diagnostic certainty of stone detection, obstruction, parenchymal lesions and morphological distinctive features. Imaging diagnoses of MDCT and IVP were compared with the final clinical diagnoses. In case of failure to detect an relevant pathology, the final clinical diagnosis was established after a mean follow-up period of 18±6 months (10 months to 2 years). Costs and radiation exposure of IVP and MDCT were compared. Results: MDCT scan performed better than IVP in terms of image quality for all regarded variables. Image quality of MDCT was rated in all parameters as very good or good; the image quality of IVP differed in a wide range. MDCT and IVP reached a sensitivity of 100% and 50% for stone detection (n=14, p=0.008), respectively. Two bladder stones were not detected by IVU but correctly seen with MDCT. MDCT and IVP were unsatisfactory for detecting transitional cell carcinomas (n=4, 2 of 4 detected with MDCT, 0 of 4 detected with IVU). One false positive transitional cell carcinoma was detected with IVP, none with MDCT. Additional relevant pathological changes (one teratoma, one abdominal aortic aneurysma and one abscess) were detected using MDCT but missed with IVP. In 38 of 59 patients (64%) imaging and clinical follow

  3. Confounding environmental colour and distribution shape leads to underestimation of population extinction risk.

    Science.gov (United States)

    Fowler, Mike S; Ruokolainen, Lasse

    2013-01-01

    The colour of environmental variability influences the size of population fluctuations when filtered through density dependent dynamics, driving extinction risk through dynamical resonance. Slow fluctuations (low frequencies) dominate in red environments, rapid fluctuations (high frequencies) in blue environments and white environments are purely random (no frequencies dominate). Two methods are commonly employed to generate the coloured spatial and/or temporal stochastic (environmental) series used in combination with population (dynamical feedback) models: autoregressive [AR(1)] and sinusoidal (1/f) models. We show that changing environmental colour from white to red with 1/f models, and from white to red or blue with AR(1) models, generates coloured environmental series that are not normally distributed at finite time-scales, potentially confounding comparison with normally distributed white noise models. Increasing variability of sample Skewness and Kurtosis and decreasing mean Kurtosis of these series alter the frequency distribution shape of the realised values of the coloured stochastic processes. These changes in distribution shape alter patterns in the probability of single and series of extreme conditions. We show that the reduced extinction risk for undercompensating (slow growing) populations in red environments previously predicted with traditional 1/f methods is an artefact of changes in the distribution shapes of the environmental series. This is demonstrated by comparison with coloured series controlled to be normally distributed using spectral mimicry. Changes in the distribution shape that arise using traditional methods lead to underestimation of extinction risk in normally distributed, red 1/f environments. AR(1) methods also underestimate extinction risks in traditionally generated red environments. This work synthesises previous results and provides further insight into the processes driving extinction risk in model populations. We must let

  4. Whole-word response scoring underestimates functional spelling ability for some individuals with global agraphia

    Directory of Open Access Journals (Sweden)

    Andrew Tesla Demarco

    2015-05-01

    These data suggest that conventional whole-word scoring may significantly underestimate functional spelling performance. Because by-letter scoring boosted pre-treatment scores to the same extent as post-treatment scores, the magnitude of treatment gains was no greater than estimates from conventional whole-word scoring. Nonetheless, the surprisingly large disparity between conventional whole-word scoring and by-letter scoring suggests that by-letter scoring methods may warrant further investigation. Because by-letter analyses may hold interest to others, we plan to make the software tool used in this study available on-line for use to researchers and clinicians at large.

  5. Satellite methods underestimate indirect climate forcing by aerosols

    Science.gov (United States)

    Penner, Joyce E.; Xu, Li; Wang, Minghuai

    2011-01-01

    Satellite-based estimates of the aerosol indirect effect (AIE) are consistently smaller than the estimates from global aerosol models, and, partly as a result of these differences, the assessment of this climate forcing includes large uncertainties. Satellite estimates typically use the present-day (PD) relationship between observed cloud drop number concentrations (Nc) and aerosol optical depths (AODs) to determine the preindustrial (PI) values of Nc. These values are then used to determine the PD and PI cloud albedos and, thus, the effect of anthropogenic aerosols on top of the atmosphere radiative fluxes. Here, we use a model with realistic aerosol and cloud processes to show that empirical relationships for ln(Nc) versus ln(AOD) derived from PD results do not represent the atmospheric perturbation caused by the addition of anthropogenic aerosols to the preindustrial atmosphere. As a result, the model estimates based on satellite methods of the AIE are between a factor of 3 to more than a factor of 6 smaller than model estimates based on actual PD and PI values for Nc. Using ln(Nc) versus ln(AI) (Aerosol Index, or the optical depth times angstrom exponent) to estimate preindustrial values for Nc provides estimates for Nc and forcing that are closer to the values predicted by the model. Nevertheless, the AIE using ln(Nc) versus ln(AI) may be substantially incorrect on a regional basis and may underestimate or overestimate the global average forcing by 25 to 35%. PMID:21808047

  6. Diagnostic yield of multidetector computed tomography in patients with acute spondylodiscitis

    Energy Technology Data Exchange (ETDEWEB)

    Rausch, Vanessa Hanna; Bannas, Peter; Well, Lennart; Regier, Marc; Adam, Gerhard; Henes, Frank Oliver Gerhard [Univ. Medical Center Hamburg-Eppendorf, Hamburg (Germany). Dept. of Diagnostic and Interventional Radiology and Nuclearmedicine; Schoen, Gerhard [Univ. Medical Center Hamburg-Eppendorf, Hamburg (Germany). Dept. of Medical Biometry and Epidemiology; Froelich, Andreas [Univ. Medical Center Hamburg-Eppendorf, Hamburg (Germany). Dept. of Neuroradiology

    2017-04-15

    To determine the value of multidetector computed tomography (MDCT) in patients with acute spondylodiscitis. For data acquisition, we searched our radiological database for all patients who had undergone magnetic resonance imaging (MRI) for suspected spondylodiscitis between 2007 and 2015 (n = 325). For further analyses, we included all patients (n = 67) who initially underwent MDCT prior to MRI. Overall accuracy, sensitivity, specificity and positive and negative predictive values were calculated for MDCT and, separately, for contrast-enhanced CT (CECT, n = 36) and for non-enhanced CT (NECT, n = 31). MRI together with clinical evaluation served as the standard of reference. Results: In 34 of 43 patients with acute spondylodiscitis on MRI, correct diagnosis was already made by the initial MDCT scan. The specificity and positive predictive value were 100% for MDCT. The sensitivity was 79% and the negative predictive value was 72%. The overall accuracy was 87%. Accuracy was higher for CECT (89%) than for NECT (84%), however without statistical significance (p = 0.55). MDCT detected 90% of paravertebral abscesses (34/38), but only 6% of epidural abscesses (2/36). MDCT has moderate sensitivity, but high specificity for acute spondylodiscitis. Thus, if MDCT is positive for spondylodiscitis, treatment can be started without further delay. However, MRI should be added to both MDCT negative and positive cases to rule out complications such as epidural abscesses that cannot reliably be detected by MDCT. Key Points: Patients with acute spondylodiscitis are often initially suspected of having other differential diagnosis because of nonspecific symptoms. Therefore, MDCT is frequently performed prior to MRI in patients with acute spondylodiscitis. MDCT proved moderate sensitivity but high specificity for the diagnosis of acute spondylodiscitis. Paravertebral abscess is a strong indicator for the presence of spondylodiscitis on MDCT. However, MRI is crucial to rule out epidural

  7. Accuracy and bias of ICT self-efficacy: an empirical study into students' over- and underestimation of their ICT competences

    NARCIS (Netherlands)

    Aesaert, K.; Voogt, J.; Kuiper, E.; van Braak, J.

    2017-01-01

    Most studies on the assessment of ICT competences use measures of ICT self-efficacy. These studies are often accused that they suffer from self-reported bias, i.e. students can over- and/or underestimate their ICT competences. As such, taking bias and accuracy of ICT self-efficacy into account,

  8. Evaluation of Left Atrial Volumes Using Multidetector Computed Tomography: Comparison with Echocardiography

    International Nuclear Information System (INIS)

    Gweon, Hye Mi; Kim, Sang Jin; Kim, Tae Hoon; Lee, Sang Min; Hong, Yoo Jin; Rim, Se Joong

    2010-01-01

    To prospectively assess the relationship between the two different measurement methods for the evaluation of left atrial (LA) volume using cardiac multidetector computed tomography (MDCT) and to compare the results between cardiac MDCT and echocardiography. Thirty-five patients (20 men, 15 women; mean age, 60 years) underwent cardiac MDCT angiography for coronary artery disease. The LA volumes were measured using two different methods: the two dimensional (2D) length-based (LB) method measured along the three-orthogonal planes of the LA and the 3D volumetric threshold-based (VTB) method measured according to the threshold 3D segmentation of the LA. The results obtained by cardiac MDCT were compared with those obtained by echocardiography. The LA end-systolic and end-diastolic volumes (LAESV and LAEDV) measured by the 2D-LB method correlated well with those measured by the 3DVTB method using cardiac MDCT (r = 0.763, r = 0.786, p = 0.001). However, there was a significant difference in the LAESVs between the two measurement methods using cardiac MDCT (p < 0.05). The LAESV measured by cardiac MDCT correlated well with measurements by echocardiography (r = 0.864, p = 0.001), however with a significant difference (p < 0.01) in their volumes. The cardiac MDCT overestimated the LAESV by 22% compared to measurements by echocardiography. A significant correlation was found between the two different measurement methods for evaluating LA volumes by cardiac MDCT. Further, cardiac MDCT correlates well with echocardiography in evaluating the LA volume. However, there are significant differences in the LAESV between the two measurement methods using cardiac MDCT and between cardiac MDCT and echocardiography

  9. T-staging of gastric cancer of air-filling multidetector-row CT: Comparison with hydro-multidetector-row CT

    Energy Technology Data Exchange (ETDEWEB)

    Kumano, Seishi, E-mail: kumano@radiol.med.kindai.ac.jp [Department of Radiology, Kinki University School of Medicine, Osakasayama, Osaka 589-8511 (Japan); Okada, Masahiro; Shimono, Taro; Kuwabara, Masatomo; Yagyu, Yukinobu; Imaoka, Izumi; Ashikaga, Ryuichiro; Ishii, Kazunari; Murakami, Takamichi [Department of Radiology, Kinki University School of Medicine, Osakasayama, Osaka 589-8511 (Japan)

    2012-11-15

    Purpose: The purpose of this study was to evaluate the accuracy of T-staging of gastric cancer by air-filling multidetector-row CT (air-MDCT) compared with water-filling MDCT (hydro-MDCT). Materials and methods: One hundred fifteen patients with histologically diagnosed gastric cancer were included in this study. Fifty-eight patients underwent air-MDCT, and the remaining 57 had hydro-MDCT using a 64-channel scanner. Based on the volumetric data of contrast-enhanced MDCT obtained about 75 s after intravenously injecting 525 mg iodine per kilogram patients weight (525 mgI/kg) nonionic contrast material at the rate of 2 ml/s, oblique coronal and oblique sagittal multi-planar reformatted images perpendicular to the stomach wall, including the tumor, were reconstructed on a workstation. Mural invasion of gastric cancer into the gastric wall, as visualized by CT, was classified according to the TNM classification, and the results of T-staging by MDCT were compared with those by pathologic analysis after surgery. Results: Correct assessment of T-staging by air-CT was achieved in 48 of 58 patients (83%), and that by hydro-MDCT was 49 of 57 patients (86%). The sensitivity, specificity, and accuracy of the technique in determining the invasion of serosa were 88%, 93%, and 91% for air-CT and 83%, 95%, and 91% for hydro-CT. There were no significant differences between hydro-MDCT and air-MDCT in sensitivity (P = 0.73), specificity (P = 0.71) and accuracy (P = 0.98). Conclusion: Air-MDCT is a very valuable tool in T-staging of gastric cancer as well as hydro-MDCT.

  10. Is oral cancer incidence among patients with oral lichen planus/oral lichenoid lesions underestimated?

    Science.gov (United States)

    Gonzalez-Moles, M A; Gil-Montoya, J A; Ruiz-Avila, I; Bravo, M

    2017-02-01

    Oral lichen planus (OLP) and oral lichenoid lesions (OLL) are considered potentially malignant disorders with a cancer incidence of around 1% of cases, although this estimation is controversial. The aim of this study was to analyze the cancer incidence in a case series of patients with OLP and OLL and to explore clinicopathological aspects that may cause underestimation of the cancer incidence in these diseases. A retrospective study was conducted of 102 patients diagnosed with OLP (n = 21, 20.58%) or OLL (n = 81) between January 2006 and January 2016. Patients were informed of the risk of malignization and followed up annually. The number of sessions programmed for each patient was compared with the number actually attended. Follow-up was classified as complete (100% attendance), good (75-99%), moderate (25-74%), or poor (<25% attendance) compliance. Cancer was developed by four patients (3.9%), three males and one male. One of these developed three carcinomas, which were diagnosed at the follow-up visit (two in lower gingiva, one in floor of mouth); one had OLL and the other three had OLP. The carcinoma developed in mucosal areas with no OLP or OLL involvement in three of these patients, while OLP and cancer were diagnosed simultaneously in the fourth. Of the six carcinomas diagnosed, five (83.3%) were T1 and one (16.7%) T2. None were N+, and all patients remain alive and disease-free. The cancer incidence in OLP and OLL appears to be underestimated due to the strict exclusion criteria usually imposed. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  11. Dual-energy X-ray absorptiometry underestimates in vivo lumbar spine bone mineral density in overweight rats.

    Science.gov (United States)

    Cherif, Rim; Vico, Laurence; Laroche, Norbert; Sakly, Mohsen; Attia, Nebil; Lavet, Cedric

    2018-01-01

    Dual-energy X-ray absorptiometry (DXA) is currently the most widely used technique for measuring areal bone mineral density (BMD). However, several studies have shown inaccuracy, with either overestimation or underestimation of DXA BMD measurements in the case of overweight or obese individuals. We have designed an overweight rat model based on junk food to compare the effect of obesity on in vivo and ex vivo BMD and bone mineral content measurements. Thirty-eight 6-month old male rats were given a chow diet (n = 13) or a high fat and sucrose diet (n = 25), with the calorie amount being kept the same in the two groups, for 19 weeks. L1 BMD, L1 bone mineral content, amount of abdominal fat, and amount of abdominal lean were obtained from in vivo DXA scan. Ex vivo L1 BMD was also measured. A difference between in vivo and ex vivo DXA BMD measurements (P body weight, perirenal fat, abdominal fat, and abdominal lean. Multiple linear regression analysis shows that body weight, abdominal fat, and abdominal lean were independently related to ex vivo BMD. DXA underestimated lumbar in vivo BMD in overweight rats, and this measurement error is related to body weight and abdominal fat. Therefore, caution must be used when one is interpreting BMD among overweight and obese individuals.

  12. Underestimating nearby nature: affective forecasting errors obscure the happy path to sustainability.

    Science.gov (United States)

    Nisbet, Elizabeth K; Zelenski, John M

    2011-09-01

    Modern lifestyles disconnect people from nature, and this may have adverse consequences for the well-being of both humans and the environment. In two experiments, we found that although outdoor walks in nearby nature made participants much happier than indoor walks did, participants made affective forecasting errors, such that they systematically underestimated nature's hedonic benefit. The pleasant moods experienced on outdoor nature walks facilitated a subjective sense of connection with nature, a construct strongly linked with concern for the environment and environmentally sustainable behavior. To the extent that affective forecasts determine choices, our findings suggest that people fail to maximize their time in nearby nature and thus miss opportunities to increase their happiness and relatedness to nature. Our findings suggest a happy path to sustainability, whereby contact with nature fosters individual happiness and environmentally responsible behavior.

  13. Multidetector-row CT: economics and workflow

    International Nuclear Information System (INIS)

    Pottala, K.M.; Kalra, M.K.; Saini, S.; Ouellette, K.; Sahani, D.; Thrall, J.H.

    2005-01-01

    With rapid evolution of multidetector-row CT (MDCT) technology and applications, several factors such ad technology upgrade and turf battles for sharing cost and profitability affect MDCT workflow and economics. MDCT workflow optimization can enhance productivity and reduce unit costs as well as increase profitability, in spite of decrease in reimbursement rates. Strategies for workflow management include standardization, automation, and constant assessment of various steps involved in MDCT operations. In this review article, we describe issues related to MDCT economics and workflow. (orig.)

  14. Tundra water budget and implications of precipitation underestimation.

    Science.gov (United States)

    Liljedahl, Anna K; Hinzman, Larry D; Kane, Douglas L; Oechel, Walter C; Tweedie, Craig E; Zona, Donatella

    2017-08-01

    Difficulties in obtaining accurate precipitation measurements have limited meaningful hydrologic assessment for over a century due to performance challenges of conventional snowfall and rainfall gauges in windy environments. Here, we compare snowfall observations and bias adjusted snowfall to end-of-winter snow accumulation measurements on the ground for 16 years (1999-2014) and assess the implication of precipitation underestimation on the water balance for a low-gradient tundra wetland near Utqiagvik (formerly Barrow), Alaska (2007-2009). In agreement with other studies, and not accounting for sublimation, conventional snowfall gauges captured 23-56% of end-of-winter snow accumulation. Once snowfall and rainfall are bias adjusted, long-term annual precipitation estimates more than double (from 123 to 274 mm), highlighting the risk of studies using conventional or unadjusted precipitation that dramatically under-represent water balance components. Applying conventional precipitation information to the water balance analysis produced consistent storage deficits (79 to 152 mm) that were all larger than the largest actual deficit (75 mm), which was observed in the unusually low rainfall summer of 2007. Year-to-year variability in adjusted rainfall (±33 mm) was larger than evapotranspiration (±13 mm). Measured interannual variability in partitioning of snow into runoff (29% in 2008 to 68% in 2009) in years with similar end-of-winter snow accumulation (180 and 164 mm, respectively) highlights the importance of the previous summer's rainfall (25 and 60 mm, respectively) on spring runoff production. Incorrect representation of precipitation can therefore have major implications for Arctic water budget descriptions that in turn can alter estimates of carbon and energy fluxes.

  15. Did the Stern Review underestimate US and global climate damages?

    International Nuclear Information System (INIS)

    Ackerman, Frank; Stanton, Elizabeth A.; Hope, Chris; Alberth, Stephane

    2009-01-01

    The Stern Review received widespread attention for its innovative approach to the economics of climate change when it appeared in 2006, and generated controversies that have continued to this day. One key controversy concerns the magnitude of the expected impacts of climate change. Stern's estimates, based on results from the PAGE2002 model, sounded substantially greater than those produced by many other models, leading several critics to suggest that Stern had inflated his damage figures. We reached the opposite conclusion in a recent application of PAGE2002 in a study of the costs to the US economy of inaction on climate change. This article describes our revisions to the PAGE estimates, and explains our conclusion that the model runs used in the Stern Review may well underestimate US and global damages. Stern's estimates from PAGE2002 implied that mean business-as-usual damages in 2100 would represent just 0.4 percent of GDP for the United States and 2.2 percent of GDP for the world. Our revisions and reinterpretation of the PAGE model imply that climate damages in 2100 could reach 2.6 percent of GDP for the United States and 10.8 percent for the world.

  16. MDCT evaluation of aortic root and aortic valve prior to TAVI. What is the optimal imaging time point in the cardiac cycle?

    Energy Technology Data Exchange (ETDEWEB)

    Jurencak, Tomas; Turek, Jakub; Nijssen, Estelle C. [Maastricht University Medical Center, Department of Radiology, P. Debyelaan 25, P.O. Box 5800, AZ, Maastricht (Netherlands); Kietselaer, Bastiaan L.J.H. [Maastricht University Medical Center, Department of Radiology, P. Debyelaan 25, P.O. Box 5800, AZ, Maastricht (Netherlands); Maastricht University Medical Center, CARIM School for Cardiovascular Diseases, Maastricht (Netherlands); Maastricht University Medical Center, Department of Cardiology, Maastricht (Netherlands); Mihl, Casper; Kok, Madeleine; Wildberger, Joachim E.; Das, Marco [Maastricht University Medical Center, Department of Radiology, P. Debyelaan 25, P.O. Box 5800, AZ, Maastricht (Netherlands); Maastricht University Medical Center, CARIM School for Cardiovascular Diseases, Maastricht (Netherlands); Ommen, Vincent G.V.A. van [Maastricht University Medical Center, Department of Cardiology, Maastricht (Netherlands); Garsse, Leen A.F.M. van [Maastricht University Medical Center, Department of Cardiothoracic Surgery, Maastricht (Netherlands)

    2015-07-15

    To determine the optimal imaging time point for transcatheter aortic valve implantation (TAVI) therapy planning by comprehensive evaluation of the aortic root. Multidetector-row CT (MDCT) examination with retrospective ECG gating was retrospectively performed in 64 consecutive patients referred for pre-TAVI assessment. Eighteen different parameters of the aortic root were evaluated at 11 different time points in the cardiac cycle. Time points at which maximal (or minimal) sizes were determined, and dimension differences to other time points were evaluated. Theoretical prosthesis sizing based on different measurements was compared. Largest dimensions were found between 10 and 20 % of the cardiac cycle for annular short diameter (10 %); mean diameter (10 %); effective diameter and circumference-derived diameter (20 %); distance from the annulus to right coronary artery ostium (10 %); aortic root at the left coronary artery level (20 %); aortic root at the widest portion of coronary sinuses (20 %); and right leaflet length (20 %). Prosthesis size selection differed depending on the chosen measurements in 25-75 % of cases. Significant changes in anatomical structures of the aortic root during the cardiac cycle are crucial for TAVI planning. Imaging in systole is mandatory to obtain maximal dimensions. (orig.)

  17. Language issues, an underestimated danger in major hazard control?

    Science.gov (United States)

    Lindhout, Paul; Ale, Ben J M

    2009-12-15

    Language issues are problems with communication via speech, signs, gestures or their written equivalents. They may result from poor reading and writing skills, a mix of foreign languages and other circumstances. Language issues are not picked up as a safety risk on the shop floor by current safety management systems. These safety risks need to be identified, acknowledged, quantified and prioritized in order to allow risk reducing measures to be taken. This study investigates the nature of language issues related danger in literature, by experiment and by a survey among the Seveso II companies in the Netherlands. Based on human error frequencies, and on the contents of accident investigation reports, the risks associated with language issues were ranked. Accident investigation method causal factor categories were found not to be sufficiently representative for the type and magnitude of these risks. Readability of safety related documents used by the companies was investigated and found to be poor in many cases. Interviews among regulators and a survey among Seveso II companies were used to identify the gap between the language issue related dangers found in literature and current best practices. This study demonstrates by means of triangulation with different investigative methods that language issue related risks are indeed underestimated. A recommended coarse of action in order to arrive at appropriate measures is presented.

  18. Language issues, an underestimated danger in major hazard control?

    Energy Technology Data Exchange (ETDEWEB)

    Lindhout, Paul, E-mail: plindhout@minszw.nl [Ministry of Social Affairs and Employment, AI-MHC, Anna van Hannoverstraat 4, P.O. Box 90801, 2509 LV The Hague (Netherlands); Ale, Ben J.M. [Delft University of Technology, TBM-Safety Science Group, Jaffalaan 5, 2628 BX Delft (Netherlands)

    2009-12-15

    Language issues are problems with communication via speech, signs, gestures or their written equivalents. They may result from poor reading and writing skills, a mix of foreign languages and other circumstances. Language issues are not picked up as a safety risk on the shop floor by current safety management systems. These safety risks need to be identified, acknowledged, quantified and prioritised in order to allow risk reducing measures to be taken. This study investigates the nature of language issues related danger in literature, by experiment and by a survey among the Seveso II companies in the Netherlands. Based on human error frequencies, and on the contents of accident investigation reports, the risks associated with language issues were ranked. Accident investigation method causal factor categories were found not to be sufficiently representative for the type and magnitude of these risks. Readability of safety related documents used by the companies was investigated and found to be poor in many cases. Interviews among regulators and a survey among Seveso II companies were used to identify the gap between the language issue related dangers found in literature and current best practices. This study demonstrates by means of triangulation with different investigative methods that language issue related risks are indeed underestimated. A recommended coarse of action in order to arrive at appropriate measures is presented.

  19. Language issues, an underestimated danger in major hazard control?

    International Nuclear Information System (INIS)

    Lindhout, Paul; Ale, Ben J.M.

    2009-01-01

    Language issues are problems with communication via speech, signs, gestures or their written equivalents. They may result from poor reading and writing skills, a mix of foreign languages and other circumstances. Language issues are not picked up as a safety risk on the shop floor by current safety management systems. These safety risks need to be identified, acknowledged, quantified and prioritised in order to allow risk reducing measures to be taken. This study investigates the nature of language issues related danger in literature, by experiment and by a survey among the Seveso II companies in the Netherlands. Based on human error frequencies, and on the contents of accident investigation reports, the risks associated with language issues were ranked. Accident investigation method causal factor categories were found not to be sufficiently representative for the type and magnitude of these risks. Readability of safety related documents used by the companies was investigated and found to be poor in many cases. Interviews among regulators and a survey among Seveso II companies were used to identify the gap between the language issue related dangers found in literature and current best practices. This study demonstrates by means of triangulation with different investigative methods that language issue related risks are indeed underestimated. A recommended coarse of action in order to arrive at appropriate measures is presented.

  20. Parenting practices, parents' underestimation of daughters' risks, and alcohol and sexual behaviors of urban girls.

    Science.gov (United States)

    O'Donnell, Lydia; Stueve, Ann; Duran, Richard; Myint-U, Athi; Agronick, Gail; San Doval, Alexi; Wilson-Simmons, Renée

    2008-05-01

    In urban economically distressed communities, high rates of early sexual initiation combined with alcohol use place adolescent girls at risk for myriad negative health consequences. This article reports on the extent to which parents of young teens underestimate both the risks their daughters are exposed to and the considerable influence that they have over their children's decisions and behaviors. Surveys were conducted with more than 700 sixth-grade girls and their parents, recruited from seven New York City schools serving low-income families. Bivariate and multivariate analyses examined relationships among parents' practices and perceptions of daughters' risks, girls' reports of parenting, and outcomes of girls' alcohol use, media and peer conduct, and heterosexual romantic and social behaviors that typically precede sexual intercourse. Although only four parents thought that their daughters had used alcohol, 22% of the daughters reported drinking in the past year. Approximately 5% of parents thought that daughters had hugged and kissed a boy for a long time or had "hung out" with older boys, whereas 38% of girls reported these behaviors. Parents' underestimation of risk was correlated with lower reports of positive parenting practices by daughters. In multivariate analyses, girls' reports of parental oversight, rules, and disapproval of risk are associated with all three behavioral outcomes. Adult reports of parenting practices are associated with girls' conduct and heterosexual behaviors, but not with their alcohol use. Creating greater awareness of the early onset of risk behaviors among urban adolescent girls is important for fostering positive parenting practices, which in turn may help parents to support their daughters' healthier choices.

  1. Assessment of alveolar bone height and width using 64-MDCT examination for dental implants

    International Nuclear Information System (INIS)

    Sekiya, Kotaro; Kaneda, Takashi; Sekiya, Keiko; Mori, Shintaro; Sakayanagi, Masashi

    2011-01-01

    There have been many reports showing the usefulness of CT examinations for preoperative dental implant treatment, and some reports on clinical statistics using CT examinations. However, there have been few reports on alveolar bone height and width of over 1,000 Japanese cases. The purpose of this study was to evaluate alveolar bone height and width of 4,123 sites in 1,056 Japanese cases using preoperative CT examinations. The subjects consisted of 4,123 regions in 1,056 cases (370 males and 686 females, mean age 56.1 years old, range 15-87) of preoperative CT examinations conducted from January 2008 to March 2009. The CT examinations were performed using the Aquilion TM 64 (Toshiba Medical Systems Corporation) as the multi detector row CT (MDCT) unit, and ZIOSTATION (ZIOSOFT) as the workstation. The CT images were displayed on the workstation, and the alveolar bone height and width were measured to one decimal place (rounded off to two decimal places). The average alveolar bone height was 14.8 mm (SD±3.8) in the upper anterior area, 11.2 mm (SD±5.5) in the upper premolar area, 6.8 mm (SD±5.4) in the upper molar area, 19.5 mm (SD±5.4) in the lower anterior area, 14.2 mm (SD±3.9) in the lower premolar area, and 13.4 mm (SD±3.4) in the lower molar area. The average alveolar bone width was 4.3 mm (SD±1.9) in the anterior area, 5.7 mm (SD±2.3) in the upper premolar area, 7.9 mm (SD±3.1) in the upper molar area, 4.8 mm (SD±2.1) in the lower anterior area, 5.9 mm (SD±2.2) in the lower premolar area, and 6.9 mm (SD±2.5) in the lower molar area. Our results using preoperative CT examinations indicated that many of the Japanese cases had insufficient alveolar bone height and width for dental implants. (author)

  2. Disguised Distress in Children and Adolescents "Flying under the Radar": Why Psychological Problems Are Underestimated and How Schools Must Respond

    Science.gov (United States)

    Flett, Gordon L.; Hewitt, Paul L.

    2013-01-01

    It is now recognized that there is a very high prevalence of psychological disorders among children and adolescents and relatively few receive psychological treatment. In the current article, we present the argument that levels of distress and dysfunction among young people are substantially underestimated and the prevalence of psychological…

  3. Maximum rates of climate change are systematically underestimated in the geological record.

    Science.gov (United States)

    Kemp, David B; Eichenseer, Kilian; Kiessling, Wolfgang

    2015-11-10

    Recently observed rates of environmental change are typically much higher than those inferred for the geological past. At the same time, the magnitudes of ancient changes were often substantially greater than those established in recent history. The most pertinent disparity, however, between recent and geological rates is the timespan over which the rates are measured, which typically differ by several orders of magnitude. Here we show that rates of marked temperature changes inferred from proxy data in Earth history scale with measurement timespan as an approximate power law across nearly six orders of magnitude (10(2) to >10(7) years). This scaling reveals how climate signals measured in the geological record alias transient variability, even during the most pronounced climatic perturbations of the Phanerozoic. Our findings indicate that the true attainable pace of climate change on timescales of greatest societal relevance is underestimated in geological archives.

  4. Confounding environmental colour and distribution shape leads to underestimation of population extinction risk.

    Directory of Open Access Journals (Sweden)

    Mike S Fowler

    Full Text Available The colour of environmental variability influences the size of population fluctuations when filtered through density dependent dynamics, driving extinction risk through dynamical resonance. Slow fluctuations (low frequencies dominate in red environments, rapid fluctuations (high frequencies in blue environments and white environments are purely random (no frequencies dominate. Two methods are commonly employed to generate the coloured spatial and/or temporal stochastic (environmental series used in combination with population (dynamical feedback models: autoregressive [AR(1] and sinusoidal (1/f models. We show that changing environmental colour from white to red with 1/f models, and from white to red or blue with AR(1 models, generates coloured environmental series that are not normally distributed at finite time-scales, potentially confounding comparison with normally distributed white noise models. Increasing variability of sample Skewness and Kurtosis and decreasing mean Kurtosis of these series alter the frequency distribution shape of the realised values of the coloured stochastic processes. These changes in distribution shape alter patterns in the probability of single and series of extreme conditions. We show that the reduced extinction risk for undercompensating (slow growing populations in red environments previously predicted with traditional 1/f methods is an artefact of changes in the distribution shapes of the environmental series. This is demonstrated by comparison with coloured series controlled to be normally distributed using spectral mimicry. Changes in the distribution shape that arise using traditional methods lead to underestimation of extinction risk in normally distributed, red 1/f environments. AR(1 methods also underestimate extinction risks in traditionally generated red environments. This work synthesises previous results and provides further insight into the processes driving extinction risk in model populations. We

  5. Multidetector row CT for imaging the paediatric tracheobronchial tree

    International Nuclear Information System (INIS)

    Papaioannou, Georgia; Young, Carolyn; Owens, Catherine M.

    2007-01-01

    The introduction of multidetector row computed tomography (MDCT) scanners has altered the approach to imaging the paediatric thorax. In an environment where the rapid acquisition of CT data allows general hospitals to image children instead of referring them to specialist paediatric centres, it is vital that general radiologists have access to protocols appropriate for paediatric applications. Thus a dramatic reduction in the delivered radiation dose is ensured with optimal contrast bolus delivery and timing, and inappropriate repetition of the scans is avoided. This article focuses on the main principles of volumetric CT imaging that apply generically to all MDCT scanners. We describe the reconstruction techniques for imaging the paediatric thorax and the low-dose protocols used in our institution on a 16-slice detector CT scanner. Examples of the commonest clinical applications are also given. (orig.)

  6. Correctness of multi-detector-row computed tomography for diagnosing mechanical prosthetic heart valve disorders using operative findings as a gold standard

    Energy Technology Data Exchange (ETDEWEB)

    Tsai, I.Chen [Taichung Veterans General Hospital, Department of Radiology, Taichung (China); Institute of Clinical Medicine and Faculty of Medicine, National Yang-Ming University, Taipei (China); Lin, Yung-Kai; Chang, Yen; Wang, Chung-Chi; Hsieh, Shih-Rong; Wei, Hao-Ji; Tsai, Hung-Wen [Taichung Veterans General Hospital, Section of Cardiovascular Surgery, Cardiovascular Center, Taichung (China); Fu, Yun-Ching; Jan, Sheng-Ling [Institute of Clinical Medicine and Faculty of Medicine, National Yang-Ming University, Taipei (China); Taichung Veterans General Hospital, Section of Pediatric Cardiology, Department of Pediatrics, Taichung (China); Wang, Kuo-Yang [Taichung Veterans General Hospital, Section of General Cardiology, Cardiovascular Center, Taichung (China); Chung-Shan Medical University, Department of Medicine, Taichung (China); Chen, Min-Chi; Chen, Clayton Chi-Chang [Taichung Veterans General Hospital, Department of Radiology, Taichung (China); Central Taiwan University of Science and Technology, Department of Radiological Technology, Taichung (China)

    2009-04-15

    The purpose was to compare the findings of multi-detector computed tomography (MDCT) in prosthetic valve disorders using the operative findings as a gold standard. In a 3-year period, we prospectively enrolled 25 patients with 31 prosthetic heart valves. MDCT and transthoracic echocardiography (TTE) were done to evaluate pannus formation, prosthetic valve dysfunction, suture loosening (paravalvular leak) and pseudoaneurysm formation. Patients indicated for surgery received an operation within 1 week. The MDCT findings were compared with the operative findings. One patient with a Bjoerk-Shiley valve could not be evaluated by MDCT due to a severe beam-hardening artifact; thus, the exclusion rate for MDCT was 3.2% (1/31). Prosthetic valve disorders were suspected in 12 patients by either MDCT or TTE. Six patients received an operation that included three redo aortic valve replacements, two redo mitral replacements and one Amplatzer ductal occluder occlusion of a mitral paravalvular leak. The concordance of MDCT for diagnosing and localizing prosthetic valve disorders and the surgical findings was 100%. Except for images impaired by severe beam-hardening artifacts, MDCT provides excellent delineation of prosthetic valve disorders. (orig.)

  7. Multidetector computed tomography sizing of bioprosthetic valves: guidelines for measurement and implications for valve-in-valve therapies

    International Nuclear Information System (INIS)

    Rajani, R.; Attia, R.; Condemi, F.; Webb, J.; Woodburn, P.; Hodson, D.; Nair, A.; Preston, R.; Razavi, R.; Bapat, V.N.

    2016-01-01

    Aim: To describe a technique for bioprosthetic multidetector computed tomography (MDCT) sizing and to compare MDCT-derived values against manufacturer-provided sizing. Materials and methods: Fourteen bioprosthetic stented valves commonly used in the aortic valve position were evaluated using a Philips 256 MDCT system. All valves were scanned using a dedicated cardiac CT protocol with a four-channel electrocardiography (ECG) simulator. Measurements were made of major and minor axes and the area and perimeter of the internal stent using varying reconstruction kernels and window settings. Measurements derived from MDCT (MDCT ID) were compared against the stent internal diameter (Stent ID) as provided by the valve manufacturer and the True ID (Stent ID + insertion of leaflets). All data were collected and analysed using SPSS for Mac (version 21). Results: The mean difference between the MDCT ID and Stent ID was 0.6±1.9 mm (r=0.649, p=0.012) and between MDCT ID and True ID 2.1±2 mm (r=0.71, p=0.005). There was no difference in the major (p=0.90), minor (p=0.87), area (p=0.92), or perimeter (p=0.92) measurements when sharp, standard, and detailed stent kernels were used. Similarly, the measurements remained consistent across differing windowing levels. Conclusion: Bioprosthetic stented valves may be reliably sized using MDCT in patients requiring valve-in-valve (VIV) interventions where the valve type and size are unknown. In these cases, clinicians should be aware that MDCT has a tendency to overestimate the True ID size. - Highlights: • Cardiac CT is likely to be ideally suited for bioprosthetic aortic valve sizing for valve in valve procedures. • We compared MDCT sizing for 14 varying bioprosthetic aortic valves across varying window settings and reconstruction kernels. • We provide “normal” MDCT sizing for varying valves and show their relationship to surgical sizing. • Bioprosthetic valves may be reliably sized by MDCT but require adjustment owing to

  8. Thin-section CT of lung without ECG gating: 64-detector row CT can markedly reduce cardiac motion artifact which can simulate lung lesions

    International Nuclear Information System (INIS)

    Yanagawa, Masahiro; Tomiyama, Noriyuki; Sumikawa, Hiromitsu; Inoue, Atsuo; Daimon, Tadahisa; Honda, Osamu; Mihara, Naoki; Johkoh, Takeshi; Nakamura, Hironobu

    2009-01-01

    Purpose: Motion artifacts, which can mimic thickened bronchial wall and the cystic appearance of bronchiectasis, constitute a potential pitfall in the diagnosis of interstitial or bronchial disease. Therefore, purpose of our study was to evaluate whether 64-detector row CT (64-MDCT) enables a reduction in respiratory or cardiac motion artifacts in the lung area on thin-section CT without ECG gating, and to examine the correlation between cardiac motion artifact and heart rate. Materials and methods: Thirty-two patients with suspected diffuse lung disease, who underwent both 8- and 64-MDCT (gantry rotation time, 0.5 and 0.4 s, respectively), were included. The heart rates of an additional 155 patients were measured (range, 48-126 beats per minute; mean, 76 beats per minute) immediately prior to 64-MDCT, and compared to the degree of cardiac motion artifact. Two independent observers evaluated the following artifacts on a monitor without the knowledge of relevant clinical information: (1) artifacts on 8- and 64-MDCT images with 1.25-mm thickness and those on 64-MDCT images with 0.625-mm thickness in 32 patients; and (2) artifacts on 64-MDCT images with 0.625-mm thickness in 155 patients. Results: Interobserver agreement was good in evaluating artifacts on 8-MDCT images with 1.25-mm thickness (weighted Kappa test, κ = 0.61-0.71), and fair or poor in the other evaluations (κ < 0.31). Two observers stated that cardiac motion artifacts were more significant on 8-MDCT than on 64-MDCT in all 32 patients. Statistically significant differences were found at various checkpoints only in comparing artifacts between 8- and 64-MDCT for 1.25-mm thickness (Wilcoxon's signed-rank test, p < 0.0017). Cardiac motion artifacts on 64-MDCT had no significant correlation with heart rate (Spearman's correlation coefficient by rank test). Conclusion: The high temporal resolution of 64-MDCT appears to reduce cardiac motion artifact that can affect thin-section scans of the lung parenchyma

  9. Thin-section CT of lung without ECG gating: 64-detector row CT can markedly reduce cardiac motion artifact which can simulate lung lesions

    Energy Technology Data Exchange (ETDEWEB)

    Yanagawa, Masahiro [Department of Radiology, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita-city, Osaka 565-0871 (Japan)], E-mail: m-yanagawa@radiol.med.osaka-u.ac.jp; Tomiyama, Noriyuki; Sumikawa, Hiromitsu; Inoue, Atsuo [Department of Radiology, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita-city, Osaka 565-0871 (Japan); Daimon, Tadahisa [Department of Radiology, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita-city, Osaka 565-0871 (Japan); Department of Medicine, Division of Pulmonary Medicine, Jichi Medical University, 3311-1 Yakushiji, Shimotsuke, Tochigi 329-0498 (Japan); Honda, Osamu [Department of Radiology, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita-city, Osaka 565-0871 (Japan); Mihara, Naoki [Department of Radiology, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita-city, Osaka 565-0871 (Japan); Department of Radiology, Osaka Advanced Medical Imaging Center, 5-20-1 Momoyamadai, Suita-city, Osaka 565-0854 (Japan); Johkoh, Takeshi [Department of Radiology, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita-city, Osaka 565-0871 (Japan); Department of Medical Physics, Osaka University Graduate School of Medicine, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita-city, Osaka 565-0871 (Japan); Nakamura, Hironobu [Department of Radiology, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita-city, Osaka 565-0871 (Japan)

    2009-01-15

    Purpose: Motion artifacts, which can mimic thickened bronchial wall and the cystic appearance of bronchiectasis, constitute a potential pitfall in the diagnosis of interstitial or bronchial disease. Therefore, purpose of our study was to evaluate whether 64-detector row CT (64-MDCT) enables a reduction in respiratory or cardiac motion artifacts in the lung area on thin-section CT without ECG gating, and to examine the correlation between cardiac motion artifact and heart rate. Materials and methods: Thirty-two patients with suspected diffuse lung disease, who underwent both 8- and 64-MDCT (gantry rotation time, 0.5 and 0.4 s, respectively), were included. The heart rates of an additional 155 patients were measured (range, 48-126 beats per minute; mean, 76 beats per minute) immediately prior to 64-MDCT, and compared to the degree of cardiac motion artifact. Two independent observers evaluated the following artifacts on a monitor without the knowledge of relevant clinical information: (1) artifacts on 8- and 64-MDCT images with 1.25-mm thickness and those on 64-MDCT images with 0.625-mm thickness in 32 patients; and (2) artifacts on 64-MDCT images with 0.625-mm thickness in 155 patients. Results: Interobserver agreement was good in evaluating artifacts on 8-MDCT images with 1.25-mm thickness (weighted Kappa test, {kappa} = 0.61-0.71), and fair or poor in the other evaluations ({kappa} < 0.31). Two observers stated that cardiac motion artifacts were more significant on 8-MDCT than on 64-MDCT in all 32 patients. Statistically significant differences were found at various checkpoints only in comparing artifacts between 8- and 64-MDCT for 1.25-mm thickness (Wilcoxon's signed-rank test, p < 0.0017). Cardiac motion artifacts on 64-MDCT had no significant correlation with heart rate (Spearman's correlation coefficient by rank test). Conclusion: The high temporal resolution of 64-MDCT appears to reduce cardiac motion artifact that can affect thin-section scans of

  10. Comparison of gated blood pool SPECT and spiral multidetector computed tomography in the assessment of right ventricular functional parameters. Validation with first-pass radionuclide angiography

    International Nuclear Information System (INIS)

    Lee, Jung S.; Kim, Seong-Jang; Kim, In-Ju; Kim, Yong-Ki; Choo, Ki S.; Lee, Jun S.

    2007-01-01

    The aim of this study was to compare gated blood pool single photon emission computed tomography (SPECT) (GBPS) and multidetector row computed tomography (MDCT) for the determination of right ventricular ejection fraction (RVEF) and right ventricular volumes (RVV) and to compare first-pass radionuclide angiography (FP-RNA) as the gold standard. Twenty consecutive patients (11 men, 9 women) referred for MDCT for the evaluation of the presence of coronary artery disease underwent FP-RNA and GBPS. The mean right ventricular end-diastolic volume (EDV) calculated with GBPS revealed a statistically significant lower value than that of MDCT. The mean right ventricular end-systolic volume (ESV) calculated with GBPS was also lower than that of MDCT. A comparison of right ventricular EDV from GBPS and MDCT yielded a correlation coefficient of 0.5972. Right ventricular ESV between GBPS and MDCT showed a correlation coefficient of 0.5650. The mean RVEFs calculated with FP-RNA (39.8%±4.0%), GBPS (43.7%±6.9%), and MDCT (40.4%±7.7%) showed no statistical differences (Kruskal-Wallis statistics 4.538, P=0.1034). A comparison of RVEFs from FP-RNA and GBPS yielded a correlation coefficient of 0.7251; RVEFs between FP-RNA and MDCT showed a correlation coefficient of 0.6166 and between GBPS and MDCT showed a correlation coefficient of 0.6367. The RVEF, EDV, and ESV calculated by GBPS had good correlation with those obtained with MDCT. In addition, there were no statistical differences of RVEF calculated from FP-RNA, GBPS, and MDCT. However, with regard to RVV, EDV and ESV from GBPS revealed statistically significantly lower values than those of MDCT. Although reasonable correlations among these modalities were obtained, the agreement among these three modalities was not good enough for interchangeable use in the clinical setting. Also, these results should be confirmed in patients with cardiac diseases in future larger population-based studies. (author)

  11. Does verbatim sentence recall underestimate the language competence of near-native speakers?

    Directory of Open Access Journals (Sweden)

    Judith eSchweppe

    2015-02-01

    Full Text Available Verbatim sentence recall is widely used to test the language competence of native and non-native speakers since it involves comprehension and production of connected speech. However, we assume that, to maintain surface information, sentence recall relies particularly on attentional resources, which differentially affects native and non-native speakers. Since even in near-natives language processing is less automatized than in native speakers, processing a sentence in a foreign language plus retaining its surface may result in a cognitive overload. We contrasted sentence recall performance of German native speakers with that of highly proficient non-natives. Non-natives recalled the sentences significantly poorer than the natives, but performed equally well on a cloze test. This implies that sentence recall underestimates the language competence of good non-native speakers in mixed groups with native speakers. The findings also suggest that theories of sentence recall need to consider both its linguistic and its attentional aspects.

  12. Look before You Leap: Underestimating Chinese Student History, Chinese University Setting and Chinese University Steering in Sino-British HE Joint Ventures?

    Science.gov (United States)

    Dow, Ewan G.

    2010-01-01

    This article makes the case--in three parts--that many Anglo-Chinese university collaborations (joint ventures) to date have seriously underestimated Chinese (student) history, the Chinese university setting and Chinese national governmental steering as part of the process of "glocalisation". Recent turbulence in this particular HE…

  13. A Novel Method Using Abstract Convex Underestimation in Ab-Initio Protein Structure Prediction for Guiding Search in Conformational Feature Space.

    Science.gov (United States)

    Hao, Xiao-Hu; Zhang, Gui-Jun; Zhou, Xiao-Gen; Yu, Xu-Feng

    2016-01-01

    To address the searching problem of protein conformational space in ab-initio protein structure prediction, a novel method using abstract convex underestimation (ACUE) based on the framework of evolutionary algorithm was proposed. Computing such conformations, essential to associate structural and functional information with gene sequences, is challenging due to the high-dimensionality and rugged energy surface of the protein conformational space. As a consequence, the dimension of protein conformational space should be reduced to a proper level. In this paper, the high-dimensionality original conformational space was converted into feature space whose dimension is considerably reduced by feature extraction technique. And, the underestimate space could be constructed according to abstract convex theory. Thus, the entropy effect caused by searching in the high-dimensionality conformational space could be avoided through such conversion. The tight lower bound estimate information was obtained to guide the searching direction, and the invalid searching area in which the global optimal solution is not located could be eliminated in advance. Moreover, instead of expensively calculating the energy of conformations in the original conformational space, the estimate value is employed to judge if the conformation is worth exploring to reduce the evaluation time, thereby making computational cost lower and the searching process more efficient. Additionally, fragment assembly and the Monte Carlo method are combined to generate a series of metastable conformations by sampling in the conformational space. The proposed method provides a novel technique to solve the searching problem of protein conformational space. Twenty small-to-medium structurally diverse proteins were tested, and the proposed ACUE method was compared with It Fix, HEA, Rosetta and the developed method LEDE without underestimate information. Test results show that the ACUE method can more rapidly and more

  14. Field Measurements Indicate Unexpected, Serious Underestimation of Mussel Heart Rates and Thermal Tolerance by Laboratory Studies.

    Directory of Open Access Journals (Sweden)

    Morgana Tagliarolo

    Full Text Available Attempts to predict the response of species to long-term environmental change are generally based on extrapolations from laboratory experiments that inevitably simplify the complex interacting effects that occur in the field. We recorded heart rates of two genetic lineages of the brown mussel Perna perna over a full tidal cycle in-situ at two different sites in order to evaluate the cardiac responses of the two genetic lineages present on the South African coast to temperature and the immersion/emersion cycle. "Robomussel" temperature loggers were used to monitor thermal conditions at the two sites over one year. Comparison with live animals showed that robomussels provided a good estimate of mussel body temperatures. A significant difference in estimated body temperatures was observed between the sites and the results showed that, under natural conditions, temperatures regularly approach or exceed the thermal limits of P. perna identified in the laboratory. The two P. perna lineages showed similar tidal and diel patterns of heart rate, with higher cardiac activity during daytime immersion and minimal values during daytime emersion. Comparison of the heart rates measured in the field with data previously measured in the laboratory indicates that laboratory results seriously underestimate heart rate activity, by as much as 75%, especially during immersion. Unexpectedly, field estimates of body temperatures indicated an ability to tolerate temperatures considered lethal on the basis of laboratory measurements. This suggests that the interaction of abiotic conditions in the field does not necessarily raise vulnerability to high temperatures.

  15. Large proportions of overweight and obese children, as well as their parents, underestimate children's weight status across Europe. The ENERGY (EuropeaN Energy balance Research to prevent excessive weight Gain among Youth) project.

    Science.gov (United States)

    Manios, Yannis; Moschonis, George; Karatzi, Kalliopi; Androutsos, Odysseas; Chinapaw, Mai; Moreno, Luis A; Bere, Elling; Molnar, Denes; Jan, Natasha; Dössegger, Alain; De Bourdeaudhuij, Ilse; Singh, Amika; Brug, Johannes

    2015-08-01

    To investigate the magnitude and country-specific differences in underestimation of children's weight status by children and their parents in Europe and to further explore its associations with family characteristics and sociodemographic factors. Children's weight and height were objectively measured. Parental anthropometric and sociodemographic data were self-reported. Children and their parents were asked to comment on children's weight status based on five-point Likert-type scales, ranging from 'I am much too thin' to 'I am much too fat' (children) and 'My child's weight is way too little' to 'My child's weight is way too much' (parents). These data were combined with children's actual weight status, in order to assess underestimation of children's weight status by children themselves and by their parents, respectively. Chi-square tests and multilevel logistic regression analyses were conducted to examine the aims of the current study. Eight European countries participating in the ENERGY (EuropeaN Energy balance Research to prevent excessive weight Gain among Youth) project. A school-based survey among 6113 children aged 10-12 years and their parents. In the total sample, 42·9 % of overweight/obese children and 27·6 % of parents of overweight/obese children underestimated their and their children's weight status, respectively. A higher likelihood for this underestimation of weight status by children and their parents was observed in Eastern and Southern compared with Central/Northern countries. Overweight or obese parents (OR=1·81; 95 % CI 1·39, 2·35 and OR=1·78, 95 % CI 1·22, 2·60), parents of boys (OR=1·32; 95 % CI 1·05, 1·67) and children from overweight/obese (OR=1·60; 95 % CI 1·29, 1·98 and OR=1·76; 95 % CI 1·29, 2·41) or unemployed parents (OR=1·53; 95 % CI 1·22, 1·92) were more likely to underestimate children's weight status. Children of overweight or obese parents, those from Eastern and Southern Europe, boys, younger children and

  16. Low radiation dose non-contrast cardiac CT: is it of value in the evaluation of mechanical aortic valve

    International Nuclear Information System (INIS)

    Bazeed, Mohamed Fayez; Moselhy, Mohamed Saleh; Rezk, Ahmad Ibrahim; Al-Murayeh, Mushabab Ayedh

    2012-01-01

    Background: Prosthetic bileaflet mechanical valve function has been traditionally evaluated using echocardiography and fluoroscopy. Multidetector computed tomography (MDCT) is a novel technique for cardiac evaluation. Purpose: To evaluate bileaflet mechanical aortic valves using a low-milliampere (mA), non-contrast MDCT protocol with a limited scan range. Material and Methods: Forty patients with a bileaflet mechanical aortic valve were evaluated using a non-contrast, low-mA, ECG-gated 64 MDCT protocol with a limited scan range. MDCT findings of opening and closing valve angles were correlated to fluoroscopy and echocardiography. Also, the valve visibility was evaluated on MDCT and fluoroscopy according to a 3-point grading scale. Results: The visualization score with the MDCT was significantly superior to the fluoroscopy (3 vs. 2.7). A strong correlation was noted between the opening (r = 0.82) and closing (r = 0.96) valve angles with MDCT and fluoroscopy without a statistically significant difference (P = 0.31 and 0.16, respectively). The mean effective radiation dose of the suggested protocol was 4 ± 0.5 mSv. Five valves were evaluated using transesophageal echocardiography because the valves were difficult to evaluate with transthoracic echocardiography, and all of these valves were evaluated optimally with MDCT. A high-pressure gradient was noted in nine valves, and the MDCT showed that seven of these valves inadequately opened, and two valves opened well, which resulted in patient valve mismatch. Incomplete valve closure was noted in five valves, and the echocardiography showed significant transvalvular regurgitation in all five valves. Conclusion: MDCT can provide a precise measurement of valve function and can potentially evaluate high-pressure gradients and transvalvular regurgitation

  17. Low radiation dose non-contrast cardiac CT: is it of value in the evaluation of mechanical aortic valve

    Energy Technology Data Exchange (ETDEWEB)

    Bazeed, Mohamed Fayez (Dept. of Diagnostic Radiology, Faculty of Medicine, Mansoura Univ. (Egypt)), email: m_bazeed@yahoo.com; Moselhy, Mohamed Saleh (Cardiology Dept. Faculty of Medicine, Suez Canal Univ. (Egypt)); Rezk, Ahmad Ibrahim (Dept. of Cardiac Surgery, Faculty of Medicine, Aim Shams Univ. (Egypt)); Al-Murayeh, Mushabab Ayedh (Dept. of Cardiac Services, Armed Forces Hospitals Southern Region (Saudi Arabia))

    2012-05-15

    Background: Prosthetic bileaflet mechanical valve function has been traditionally evaluated using echocardiography and fluoroscopy. Multidetector computed tomography (MDCT) is a novel technique for cardiac evaluation. Purpose: To evaluate bileaflet mechanical aortic valves using a low-milliampere (mA), non-contrast MDCT protocol with a limited scan range. Material and Methods: Forty patients with a bileaflet mechanical aortic valve were evaluated using a non-contrast, low-mA, ECG-gated 64 MDCT protocol with a limited scan range. MDCT findings of opening and closing valve angles were correlated to fluoroscopy and echocardiography. Also, the valve visibility was evaluated on MDCT and fluoroscopy according to a 3-point grading scale. Results: The visualization score with the MDCT was significantly superior to the fluoroscopy (3 vs. 2.7). A strong correlation was noted between the opening (r = 0.82) and closing (r = 0.96) valve angles with MDCT and fluoroscopy without a statistically significant difference (P = 0.31 and 0.16, respectively). The mean effective radiation dose of the suggested protocol was 4 +- 0.5 mSv. Five valves were evaluated using transesophageal echocardiography because the valves were difficult to evaluate with transthoracic echocardiography, and all of these valves were evaluated optimally with MDCT. A high-pressure gradient was noted in nine valves, and the MDCT showed that seven of these valves inadequately opened, and two valves opened well, which resulted in patient valve mismatch. Incomplete valve closure was noted in five valves, and the echocardiography showed significant transvalvular regurgitation in all five valves. Conclusion: MDCT can provide a precise measurement of valve function and can potentially evaluate high-pressure gradients and transvalvular regurgitation

  18. Late enhanced computed tomography in Hypertrophic Cardiomyopathy enables accurate left-ventricular volumetry

    Energy Technology Data Exchange (ETDEWEB)

    Langer, Christoph; Lutz, M.; Kuehl, C.; Frey, N. [Christian-Albrechts-Universitaet Kiel, Department of Cardiology, Angiology and Critical Care Medicine, University Medical Center Schleswig-Holstein (Germany); Partner Site Hamburg/Kiel/Luebeck, DZHK (German Centre for Cardiovascular Research), Kiel (Germany); Both, M.; Sattler, B.; Jansen, O; Schaefer, P. [Christian-Albrechts-Universitaet Kiel, Department of Diagnostic Radiology, University Medical Center Schleswig-Holstein (Germany); Harders, H.; Eden, M. [Christian-Albrechts-Universitaet Kiel, Department of Cardiology, Angiology and Critical Care Medicine, University Medical Center Schleswig-Holstein (Germany)

    2014-10-15

    Late enhancement (LE) multi-slice computed tomography (leMDCT) was introduced for the visualization of (intra-) myocardial fibrosis in Hypertrophic Cardiomyopathy (HCM). LE is associated with adverse cardiac events. This analysis focuses on leMDCT derived LV muscle mass (LV-MM) which may be related to LE resulting in LE proportion for potential risk stratification in HCM. N=26 HCM-patients underwent leMDCT (64-slice-CT) and cardiovascular magnetic resonance (CMR). In leMDCT iodine contrast (Iopromid, 350 mg/mL; 150mL) was injected 7 minutes before imaging. Reconstructed short cardiac axis views served for planimetry. The study group was divided into three groups of varying LV-contrast. LeMDCT was correlated with CMR. The mean age was 64.2 ± 14 years. The groups of varying contrast differed in weight and body mass index (p < 0.05). In the group with good LV-contrast assessment of LV-MM resulted in 147.4 ± 64.8 g in leMDCT vs. 147.1 ± 65.9 in CMR (p > 0.05). In the group with sufficient contrast LV-MM appeared with 172 ± 30.8 g in leMDCT vs. 165.9 ± 37.8 in CMR (p > 0.05). Overall intra-/inter-observer variability of semiautomatic assessment of LV-MM showed an accuracy of 0.9 ± 8.6 g and 0.8 ± 9.2 g in leMDCT. All leMDCT-measures correlated well with CMR (r > 0.9). LeMDCT primarily performed for LE-visualization in HCM allows for accurate LV-volumetry including LV-MM in > 90 % of the cases. (orig.)

  19. Preoperative evaluation of hilar vessel anatomy with 3-D computerized tomography in living kidney donors.

    Science.gov (United States)

    Tombul, S T; Aki, F T; Gunay, M; Inci, K; Hazirolan, T; Karcaaltincaba, M; Erkan, I; Bakkaloglu, A; Yasavul, U; Bakkaloglu, M

    2008-01-01

    Digital subtract angiography is the gold standard for anatomic assessment of renal vasculature for living renal donors. However, multidetector-row computerized tomography (MDCT) is less invasive than digital subtract angiography and provides information of kidney stones and other intra-abdominal organs. In this study, preoperative MDCT angiography results were compared with the peroperative findings to evaluate the accuracy of MDCT for the evaluation of renal anatomy. From December 2002 to May 2007, all 60 consecutive living kidney donors were evaluated with MDCT angiography preoperatively. We reported the number and origin of renal arteries, presence of early branching arteries, and any intrinsic renal artery disease. Renal venous anatomy was evaluated for the presence of accessory, retroaortic, and circumaortic veins using venous phase axial images. The calyces and ureters were assessed with delayed topograms. The results of the MDCT angiography were compared with the peroperative findings. A total of 67 renal arteries were seen peroperatively in 60 renal units. Preoperative MDCT angiography detected 64 of them. The two arteries not detected by MDCT had diameters less than 3 mm. Anatomic variations were present in nine veins, five of which were detected by CT angiography. Sensitivity of MDCT angiography for arteries and veins was 95% and 93%, respectively. Positive predictive values were 100% for both arteries and veins. MDCT angiography offers a less invasive, rapid, and accurate preoperative investigation modality for vascular anatomy in living kidney donors. It also provides sufficient information about extrarenal anatomy important for donor surgery.

  20. Multidetector computed tomography with triple-bolus contrast medium administration protocol for preoperative anatomical and functional assessment of potential living renal donors

    International Nuclear Information System (INIS)

    Knox, Matthew K.; Rivers-Bowerman, Michael D.; Bardgett, Harry P.; Cowan, Nigel C.

    2010-01-01

    To evaluate multidetector computed tomography (MDCT) with a triple-bolus contrast administration protocol for preoperative anatomical and functional assessment of living renal donors. Fifty-five potential living renal donors underwent MDCT of which 27 proceeded to donor nephrectomy. A triple-bolus contrast administration protocol was used for simultaneous acquisition of arterial, nephrographic, and excretory phases. MDCT images were independently reviewed in random order by two radiologists blinded to surgical anatomy findings. Diagnostic accuracy for anatomical variants was quantified by sensitivity and specificity. Differential renal function (DRF) was derived from MDCT for 54 patients and compared with technetium-99 m dimercaptosuccinic acid renography (Tc-99 m DMSA). All triple-bolus MDCT examinations were technically adequate. Accessory renal arteries and veins were identified at surgery in 33% (n = 9/27) and 22% (n = 6/27) of donor kidneys. The mean difference between MDCT-derived DRF and DMSA was 0.8% (95% CI 0.1-1.6) with 95% limits of agreement of -4.6% (95% CI -3.3 to -5.9) to 6.3% (95% CI 5.0-7.6). MDCT delivered a mean (SD, range) radiation dose of 9.5 (3.6, 3.6-17.3) mSv. MDCT with a triple-bolus contrast administration provides accurate anatomical and functional evaluation of living renal donors. (orig.)

  1. Multidetector computed tomography with triple-bolus contrast medium administration protocol for preoperative anatomical and functional assessment of potential living renal donors

    Energy Technology Data Exchange (ETDEWEB)

    Knox, Matthew K. [University of Calgary, Faculty of Medicine, UME Office, Health Sciences Centre, Calgary, Alberta (Canada); Rivers-Bowerman, Michael D. [University of British Columbia, Faculty of Medicine, MD Undergraduate Program, Diamond Health Care Centre, Vancouver, British Columbia (Canada); Bardgett, Harry P. [Bradford Teaching Hospitals, Department of Radiology, Bradford (United Kingdom); Cowan, Nigel C. [The Churchill Hospital, Department of Radiology, Oxford (United Kingdom)

    2010-11-15

    To evaluate multidetector computed tomography (MDCT) with a triple-bolus contrast administration protocol for preoperative anatomical and functional assessment of living renal donors. Fifty-five potential living renal donors underwent MDCT of which 27 proceeded to donor nephrectomy. A triple-bolus contrast administration protocol was used for simultaneous acquisition of arterial, nephrographic, and excretory phases. MDCT images were independently reviewed in random order by two radiologists blinded to surgical anatomy findings. Diagnostic accuracy for anatomical variants was quantified by sensitivity and specificity. Differential renal function (DRF) was derived from MDCT for 54 patients and compared with technetium-99 m dimercaptosuccinic acid renography (Tc-99 m DMSA). All triple-bolus MDCT examinations were technically adequate. Accessory renal arteries and veins were identified at surgery in 33% (n = 9/27) and 22% (n = 6/27) of donor kidneys. The mean difference between MDCT-derived DRF and DMSA was 0.8% (95% CI 0.1-1.6) with 95% limits of agreement of -4.6% (95% CI -3.3 to -5.9) to 6.3% (95% CI 5.0-7.6). MDCT delivered a mean (SD, range) radiation dose of 9.5 (3.6, 3.6-17.3) mSv. MDCT with a triple-bolus contrast administration provides accurate anatomical and functional evaluation of living renal donors. (orig.)

  2. Split-bolus single-phase cardiac multidetector computed tomography for reliable detection of left atrial thrombus. Comparison to transesophageal echocardiography

    Energy Technology Data Exchange (ETDEWEB)

    Staab, W.; Zwaka, P.A.; Sohns, J.M.; Schwarz, A.; Lotz, J. [University Medical Center Goettingen Univ. (Germany). Inst. for Diagnostic and Interventional Radiology; Sohns, C.; Vollmann, D.; Zabel, M.; Hasenfuss, G. [Goettingen Univ. (Germany). Dept. of Cardiology and Pneumology; Schneider, S. [Goettingen Univ. (Germany). Dept. of Medical Statistics

    2014-11-15

    Evaluation of a new cardiac MDCT protocol using a split-bolus contrast injection protocol and single MDCT scan for reliable diagnosis of LA/LAA thrombi in comparison to TEE, optimizing radiation exposure and use of contrast agent. A total of 182 consecutive patients with drug refractory AF scheduled for PVI (62.6% male, mean age: 64.1 ± 10.2 years) underwent routine diagnostic work including TEE and cardiac MDCT for the evaluation of LA/LAA anatomy and thrombus formation between November 2010 and March 2012. Contrast media injection was split into a pre-bolus of 30 ml and main bolus of 70 ml iodinated contrast agent separated by a short time delay. In this study, split-bolus cardiac MDCT identified 14 of 182 patients with filling defects of the LA/LAA. In all of these 14 patients, abnormalities were found in TEE. All 5 of the 14 patients with thrombus formation in cardiac MDCT were confirmed by TEE. MDCT was 100% accurate for thrombus, with strong but not perfect overall results for SEC equivalent on MDCT.

  3. 320-Multidetector row whole-head dynamic subtracted CT angiography and whole-brain CT perfusion before and after carotid artery stenting: Technical note

    International Nuclear Information System (INIS)

    San Millan Ruiz, Diego; Murphy, Kieran; Gailloud, Philippe

    2010-01-01

    Introduction: Multidetector CT (MDCT) is increasingly used for the investigation of neurovascular disorders, but restricted z-axis coverage (3.2 cm for 64-MDCT) currently limits perfusion to a small portion of the brain close to the circle of Willis, and precludes dynamic angiographic appreciation of the entire brain circulation. We illustrate the clinical potential of recently developed 320-MDCT extending the z-axis coverage to 16 cm in a patient with symptomatic carotid artery stenosis. Methods: In a 74-year-old patient presenting with critical symptomatic stenosis of the left CCA, pre- and post-carotid artery stenting whole-head subtracted dynamic MDCT angiography and perfusion were obtained in addition to CT angiography of the supra-aortic trunks. Both whole-head subtracted MDCT angiography and perfusion demonstrated delayed left ICA circulation, which normalized after carotid stenting. Discussion: 320-MDCT offers unprecedented z-axis coverage allowing for whole-brain perfusion and subtracted dynamic angiography of the entire intracranial circulation. These innovations can consolidate the role of MDCT as a first intention imaging technique for cerebrovascular disorders, in particular for the acute management of stroke.

  4. On the intra-seasonal variability within the extratropics in the ECHAM3 general circulation model

    International Nuclear Information System (INIS)

    May, W.

    1994-01-01

    First we consider the GCM's capability to reproduce the midlatitude variability on intra-seasonal time scales by a comparison with observational data (ECMWF analyses). Secondly we assess the possible influence of Sea Surface Temperatures on the intra-seasonal variability by comparing estimates obtained from different simulations performed with ECHAM3 with varying and fixed SST as boundary forcing. The intra-seasonal variability as simulated by ECHAM3 is underestimated over most of the Northern Hemisphere. While the contributions of the high-frequency transient fluctuations are reasonably well captured by the model, ECHAM3 fails to reproduce the observed level of low-frequency intra-seasonal variability. This is mainly due to the underestimation of the variability caused by the ultra-long planetary waves in the Northern Hemisphere midlatitudes by the model. In the Southern Hemisphere midlatitudes, on the other hand, the intra-seasonal variability as simulated by ECHAM3 is generally underestimated in the area north of about 50 southern latitude, but overestimated at higher latitudes. This is the case for the contributions of the high-frequency and the low-frequency transient fluctuations as well. Further, the model indicates a strong tendency for zonal symmetry, in particular with respect to the high-frequency transient fluctuations. While the two sets of simulations with varying and fixed Sea Surface Temepratures as boundary forcing reveal only small regional differences in the Southern Hemisphere, there is a strong response to be found in the Northern Hemisphere. The contributions of the high-frequency transient fluctuations to the intra-seasonal variability are generally stronger in the simulations with fixed SST. Further, the Pacific storm track is shifted slightly poleward in this set of simulations. For the low-frequency intra-seasonal variability the model gives a strong, but regional response to the interannual variations of the SST. (orig.)

  5. Pain begets pain: When marathon runners are not in pain anymore, they underestimate their memory of marathon pain: A mediation analysis

    NARCIS (Netherlands)

    Babel, P.; Bajcar, E.A.; Smieja, M.; Adamczyk, W.; Swider, K.J.; Kicman, P.; Lisinska, N.

    2018-01-01

    Background: A previous study has shown that memory of pain induced by running a marathon might be underestimated. However, little is known about the factors that might influence such a memory distortion during pain recall. The aim of the study was to investigate the memory of pain induced by running

  6. Soft tissue buccal carcinoma - a role of MDCT and PET/CT during the staging procedure

    International Nuclear Information System (INIS)

    Al-Amin, M.; Zlatareva, D.; Dineva, S.; Hadjidekov, V.; Kostadinova, I.; Al-Amin, B.

    2013-01-01

    Full text: Introduction: The incidence of buccal mucosa carcinoma is 8-10 % of cancers developing in the oral mucosa. Most often it develops on prior pre-neoplasia: leucoplakia, lichen. Characterized by painless in the early growth. The tumor is widely and quickly grows into the underlying tissues. Contracture are common. Histologically settled mostly squamous cell carcinoma and rarely glandular small salivary glands. What you will learn: A case study about a patient referred by a dentist with a painless swelling of the face on the right, with tightly - elastin texture appeared about 3 months ago is presented . Patient has difficulty swallowing, talking and breathing and limited mouth opening. Discussion: A MDCT study with intravenous contrast medium was performed for findings staging. It is found a heterodense tumor formation, involving the nasopharynx and oropharynx right without infiltration of main blood vessels with destruction of almost the entire branch of the mandible, with an interruption of the processus caronoideus integrity as well as the lateral wall and floor of the right maxillary sinus. The diagnose is buccal tumor formation in stage T4 N2V, Mx. The patient was referred to a specialized hospital for active treatment in maxillofacial surgery, where a biopsy was done and the histological result is: moderately differentiated buccal and gingival squamous cell carcinoma. From X-ray study of the lungs and heart several pulmonary nodules are identified and there is a possibility for metastatic lesions. Patient was referred for restaging and conducting whole body PET/CT. It is found a metabolically active tumor formation with data for regional lymphatic dissemination in the right. Conclusion: Squamous cell carcinoma is the most common cancer of the oral cavity (90-95 %). Buccal carcinoma represents 9.8% of cancer of the oral cavity and maxillofacial area. Treatment is complex. The five-year survival in T3 and T4 stages is 20-30%

  7. Cine MRI of Tracheal Dynamics in Healthy Volunteers and Patients With Tracheobronchomalacia.

    Science.gov (United States)

    Ciet, Pierluigi; Boiselle, Phillip M; Heidinger, Benedikt; Andrinopoulou, Eleni-Rosalina; O'Donnel, Carl; Alsop, David C; Litmanovich, Diana E

    2017-10-01

    Bronchoscopy and MDCT are routinely used to assess tracheobronchomalacia (TBM). Recently, dynamic MRI (cine MRI) has been proposed as a radiation-free alternative to MDCT. In this study, we tested cine MRI assessment of airway dynamics during various breathing conditions and compared cine MRI and MDCT measurements in healthy volunteers and patients with suspected TBM. Cine MRI was found to be a technically feasible alternative to MDCT for assessing central airway dynamics.

  8. Underestimated Halogen Bonds Forming with Protein Backbone in Protein Data Bank.

    Science.gov (United States)

    Zhang, Qian; Xu, Zhijian; Shi, Jiye; Zhu, Weiliang

    2017-07-24

    Halogen bonds (XBs) are attracting increasing attention in biological systems. Protein Data Bank (PDB) archives experimentally determined XBs in biological macromolecules. However, no software for structure refinement in X-ray crystallography takes into account XBs, which might result in the weakening or even vanishing of experimentally determined XBs in PDB. In our previous study, we showed that side-chain XBs forming with protein side chains are underestimated in PDB on the basis of the phenomenon that the proportion of side-chain XBs to overall XBs decreases as structural resolution becomes lower and lower. However, whether the dominant backbone XBs forming with protein backbone are overlooked is still a mystery. Here, with the help of the ratio (R F ) of the observed XBs' frequency of occurrence to their frequency expected at random, we demonstrated that backbone XBs are largely overlooked in PDB, too. Furthermore, three cases were discovered possessing backbone XBs in high resolution structures while losing the XBs in low resolution structures. In the last two cases, even at 1.80 Å resolution, the backbone XBs were lost, manifesting the urgent need to consider XBs in the refinement process during X-ray crystallography study.

  9. Low modeled ozone production suggests underestimation of precursor emissions (especially NOx) in Europe

    Science.gov (United States)

    Oikonomakis, Emmanouil; Aksoyoglu, Sebnem; Ciarelli, Giancarlo; Baltensperger, Urs; Prévôt, André Stephan Henry

    2018-02-01

    High surface ozone concentrations, which usually occur when photochemical ozone production takes place, pose a great risk to human health and vegetation. Air quality models are often used by policy makers as tools for the development of ozone mitigation strategies. However, the modeled ozone production is often not or not enough evaluated in many ozone modeling studies. The focus of this work is to evaluate the modeled ozone production in Europe indirectly, with the use of the ozone-temperature correlation for the summer of 2010 and to analyze its sensitivity to precursor emissions and meteorology by using the regional air quality model, the Comprehensive Air Quality Model with Extensions (CAMx). The results show that the model significantly underestimates the observed high afternoon surface ozone mixing ratios (≥ 60 ppb) by 10-20 ppb and overestimates the lower ones (degradation of the model performance for the lower ozone mixing ratios. The model performance for ozone-temperature correlation is also better when NOx emissions are doubled. In the Benelux area, however, the third scenario (where both NOx and VOC emissions are increased) leads to a better model performance. Although increasing only the traffic NOx emissions by a factor of 4 gave very similar results to the doubling of all NOx emissions, the first scenario is more consistent with the uncertainties reported by other studies than the latter, suggesting that high uncertainties in NOx emissions might originate mainly from the road-transport sector rather than from other sectors. The impact of meteorology was examined with three sensitivity tests: (i) increased surface temperature by 4 °C, (ii) reduced wind speed by 50 % and (iii) doubled wind speed. The first two scenarios led to a consistent increase in all surface ozone mixing ratios, thus improving the model performance for the high ozone values but significantly degrading it for the low ozone values, while the third scenario had exactly the

  10. A Bayesian model to correct underestimated 3-D wind speeds from sonic anemometers increases turbulent components of the surface energy balance

    Science.gov (United States)

    John M. Frank; William J. Massman; Brent E. Ewers

    2016-01-01

    Sonic anemometers are the principal instruments in micrometeorological studies of turbulence and ecosystem fluxes. Common designs underestimate vertical wind measurements because they lack a correction for transducer shadowing, with no consensus on a suitable correction. We reanalyze a subset of data collected during field experiments in 2011 and 2013 featuring two or...

  11. Fractal Dimension Analysis of MDCT Images for Quantifying the Morphological Changes of the Pulmonary Artery Tree in Patients with Pulmonary Hypertension

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Haitao; Li, Ning; Guo, Lijun; Gao, Fei; Liu, Cheng [Shandong University, Shandong Medical Imaging Research Institute, Shandong (Korea, Republic of)

    2011-06-15

    The aim of this study was to use fractal dimension (FD) analysis on multidetector CT (MDCT) images for quantifying the morphological changes of the pulmonary artery tree in patients with pulmonary hypertension (PH). Fourteen patients with PH and 17 patients without PH as controls were studied. All of the patients underwent contrast-enhanced helical CT and transthoracic echocardiography. The pulmonary artery trees were generated using post-processing software, and the FD and projected image area of the pulmonary artery trees were determined with Image J software in a personal computer. The FD, the projected image area and the pulmonary artery pressure (PAP) were statistically evaluated in the two groups. The FD, the projected image area and the PAP of the patients with PH were higher than those values of the patients without PH (p < 0.05, t-test). There was a high correlation of FD with the PAP (r = 0.82, p < 0.05, partial correlation analysis). There was a moderate correlation of FD with the projected image area (r = 0.49, p < 0.05, partial correlation analysis). There was a correlation of the PAP with the projected image area (r = 0.65, p < 0.05, Pearson correlation analysis). The FD of the pulmonary arteries in the PH patients was significantly higher than that of the controls. There is a high correlation of FD with the PAP.

  12. Fractal Dimension Analysis of MDCT Images for Quantifying the Morphological Changes of the Pulmonary Artery Tree in Patients with Pulmonary Hypertension

    International Nuclear Information System (INIS)

    Sun, Haitao; Li, Ning; Guo, Lijun; Gao, Fei; Liu, Cheng

    2011-01-01

    The aim of this study was to use fractal dimension (FD) analysis on multidetector CT (MDCT) images for quantifying the morphological changes of the pulmonary artery tree in patients with pulmonary hypertension (PH). Fourteen patients with PH and 17 patients without PH as controls were studied. All of the patients underwent contrast-enhanced helical CT and transthoracic echocardiography. The pulmonary artery trees were generated using post-processing software, and the FD and projected image area of the pulmonary artery trees were determined with Image J software in a personal computer. The FD, the projected image area and the pulmonary artery pressure (PAP) were statistically evaluated in the two groups. The FD, the projected image area and the PAP of the patients with PH were higher than those values of the patients without PH (p < 0.05, t-test). There was a high correlation of FD with the PAP (r = 0.82, p < 0.05, partial correlation analysis). There was a moderate correlation of FD with the projected image area (r = 0.49, p < 0.05, partial correlation analysis). There was a correlation of the PAP with the projected image area (r = 0.65, p < 0.05, Pearson correlation analysis). The FD of the pulmonary arteries in the PH patients was significantly higher than that of the controls. There is a high correlation of FD with the PAP.

  13. Flat epithelial atypia and atypical ductal hyperplasia: carcinoma underestimation rate.

    Science.gov (United States)

    Ingegnoli, Anna; d'Aloia, Cecilia; Frattaruolo, Antonia; Pallavera, Lara; Martella, Eugenia; Crisi, Girolamo; Zompatori, Maurizio

    2010-01-01

    This study was carried out to determine the underestimation rate of carcinoma upon surgical biopsy after a diagnosis of flat epithelial atypia and atypical ductal hyperplasia and 11-gauge vacuum-assisted breast biopsy. A retrospective review was conducted of 476 vacuum-assisted breast biopsy performed from May 2005 to January 2007 and a total of 70 cases of atypia were identified. Fifty cases (71%) were categorized as pure atypical ductal hyperplasia, 18 (26%) as pure flat epithelial atypia and two (3%) as concomitant flat epithelial atypia and atypical ductal hyperplasia. Each group were compared with the subsequent open surgical specimens. Surgical biopsy was performed in 44 patients with atypical ductal hyperplasia, 15 patients with flat epithelial atypia, and two patients with flat epithelial atypia and atypical ductal hyperplasia. Five cases of atypical ductal hyperplasia were upgraded to ductal carcinoma in situ, three cases of flat epithelial atypia yielded one ductal carcinoma in situ and two cases of invasive ductal carcinoma, and one case of flat epithelial atypia/atypical ductal hyperplasia had invasive ductal carcinoma. The overall rate of malignancy was 16% for atypical ductal hyperplasia (including flat epithelial atypia/atypical ductal hyperplasia patients) and 20% for flat epithelial atypia. The presence of flat epithelial atypia and atypical ductal hyperplasia at biopsy requires careful consideration, and surgical excision should be suggested.

  14. Evaluation of radiation dose in 64-row whole-body CT of multiple injured patients compared to 4-row CT

    International Nuclear Information System (INIS)

    Harrieder, A.; Geyer, L.L.; Koerner, M.; Deak, Z.; Wirth, S.; Reiser, M.; Linsenmaier, U.

    2012-01-01

    Purpose: To evaluate radiation exposure in whole-body CT (WBCT) of multiple injured patients comparing 4-row multidetector computed tomography (MDCT) to 64-row MDCT. Materials and Methods: 200 WBCT studies were retrospectively evaluated: 92 4-row MDCT scans and 108 64-row MDCT scans. Each CT protocol was optimized for the particular CT system. The scan length, CT dose index (CTDI), and dose length product (DLP) were recorded and analyzed for radiation exposure. The mean effective dose was estimated based on conversion factors. Student's t-test was used for statistical analysis. Results: The mean CTDI vol values (mGy) of the thorax and abdomen were significantly reduced with 64-row MDCT (10.2 ± 2.5 vs. 11.4 ± 1.4, p < 0.001; 14.2 ± 3.7 vs. 16.1 ± 1.7, p < 0.001). The DLP values (mGy x cm) of the head and thorax were significantly increased with 64-row MDCT (1305.9 ± 201.1 vs. 849.8 ± 90.9, p < 0,001; 504.4 ± 134.4 vs. 471.5 ± 74.1, p = 0.030). The scan lengths (mm) were significantly increased with 64-row MDCT: head 223.6 ± 35.8 vs. 155.5 ± 12.3 (p < 0.001), thorax 427.4 ± 44.5 vs. 388.3 ± 57.5 (p < 0.001), abdomen 520.3 ± 50.2 vs. 490.8 ± 51.6 (p < 0.001). The estimated mean effective doses (mSv) were 22.4 ± 2.6 (4-row MDCT) and 24.1 ± 4.6 (64-row MDCT; p = 0.001), resulting in a percentage increase of 8 %. Conclusion: The radiation dose per slice of the thorax and abdomen can be significantly decreased by using 64-row MDCT. Due to the technical advances of modern 64-row MDCT systems, the scan field can be adapted to the clinical demands and, if necessary, enlarged without time loss. As a result, the estimated mean effective dose might be increased in WBCT. (orig.)

  15. Evaluation of radiation dose in 64-row whole-body CT of multiple injured patients compared to 4-row CT; Evaluation der Strahlendosis bei Polytrauma-CT-Untersuchungen eines 64-Zeilen-CT im Vergleich zur 4-Zeilen-CT

    Energy Technology Data Exchange (ETDEWEB)

    Harrieder, A.; Geyer, L.L.; Koerner, M.; Deak, Z.; Wirth, S.; Reiser, M.; Linsenmaier, U. [Ludwig-Maximilians-Univ. Muenchen (Germany). Inst. fuer Klinische Radiologie

    2012-05-15

    Purpose: To evaluate radiation exposure in whole-body CT (WBCT) of multiple injured patients comparing 4-row multidetector computed tomography (MDCT) to 64-row MDCT. Materials and Methods: 200 WBCT studies were retrospectively evaluated: 92 4-row MDCT scans and 108 64-row MDCT scans. Each CT protocol was optimized for the particular CT system. The scan length, CT dose index (CTDI), and dose length product (DLP) were recorded and analyzed for radiation exposure. The mean effective dose was estimated based on conversion factors. Student's t-test was used for statistical analysis. Results: The mean CTDI{sub vol} values (mGy) of the thorax and abdomen were significantly reduced with 64-row MDCT (10.2 {+-} 2.5 vs. 11.4 {+-} 1.4, p < 0.001; 14.2 {+-} 3.7 vs. 16.1 {+-} 1.7, p < 0.001). The DLP values (mGy x cm) of the head and thorax were significantly increased with 64-row MDCT (1305.9 {+-} 201.1 vs. 849.8 {+-} 90.9, p < 0,001; 504.4 {+-} 134.4 vs. 471.5 {+-} 74.1, p = 0.030). The scan lengths (mm) were significantly increased with 64-row MDCT: head 223.6 {+-} 35.8 vs. 155.5 {+-} 12.3 (p < 0.001), thorax 427.4 {+-} 44.5 vs. 388.3 {+-} 57.5 (p < 0.001), abdomen 520.3 {+-} 50.2 vs. 490.8 {+-} 51.6 (p < 0.001). The estimated mean effective doses (mSv) were 22.4 {+-} 2.6 (4-row MDCT) and 24.1 {+-} 4.6 (64-row MDCT; p = 0.001), resulting in a percentage increase of 8 %. Conclusion: The radiation dose per slice of the thorax and abdomen can be significantly decreased by using 64-row MDCT. Due to the technical advances of modern 64-row MDCT systems, the scan field can be adapted to the clinical demands and, if necessary, enlarged without time loss. As a result, the estimated mean effective dose might be increased in WBCT. (orig.)

  16. Usefulness of preoperative chest multidetector CT for evaluation of breast cancer: comparison with breast MRI

    International Nuclear Information System (INIS)

    Chang, Yun Woo; Kim, Dong Hun; Lee, Min Hyuk

    2005-01-01

    To evaluate the efficacy of chest multidetector-row helical computed tomography (MDCT) in detecting breast cancer in preoperative metastasis work-ups and to assess the accuracy of MDCT compared with magnetic resonance imaging (MRI). MDCT were performed on 69 consecutive patients with 94 lesions of histologically proven breast cancer. Retrospectively, two radiologists performed a blind review of the MDCT images for margin, shape, mass enhancement pattern and the enhancing distribution of non-mass lesions with consensus. CT attenuation values were measured in the average HU on pre-enhancing and enhanced CT in gland, fat, muscle, and in masses with the largest region of interest (ROI). MDCT finding were analyzed and compared with breast MRI. Of the 91 breast lesions detected on MDCT, 64 were mass lesions and 24 were non-mass lesions on enhancement, 86 lesions were malignant and 5 were benign. Three pathologically proven malignant masses were not detected on MDCT. Positive predictive value, false positive rate and false negative rate were 94.5%, 5.3%, 3.2% respectively. The highly predictive features for malignancy were a spiculated or irregular margin, an irregular of round shape, and a heterogeneously or rim enhanced mass. Another highly predictive feature for malignancy was linear or segmentally distributed enhancing non-mass lesions. The CT values of masses in pre-enhanced scans were 38.6 ± 7.9 HU; these values increased to 110.9 ± 26.6 HU after contrast injection (90 sec). The attenuation values from enhancing CT of malignant lesions were significantly higher than those of non-enhancing lesions. The depiction of enhancing masses on MDCT compared with MR imaging were 88.6%. The extension of malignancy were equally well correlated MDCT with MR imaging. The diagnostic value of chest MDCT for preoperative staging is comparable with MR imaging for the detection and extension of lesions. Therefore, chest MDCT of breast cancer can add to the information obtained from

  17. Are WISC IQ scores in children with mathematical learning disabilities underestimated? The influence of a specialized intervention on test performance.

    Science.gov (United States)

    Lambert, Katharina; Spinath, Birgit

    2018-01-01

    Intelligence measures play a pivotal role in the diagnosis of mathematical learning disabilities (MLD). Probably as a result of math-related material in IQ tests, children with MLD often display reduced IQ scores. However, it remains unclear whether the effects of math remediation extend to IQ scores. The present study investigated the impact of a special remediation program compared to a control group receiving private tutoring (PT) on the WISC IQ scores of children with MLD. We included N=45 MLD children (7-12 years) in a study with a pre- and post-test control group design. Children received remediation for two years on average. The analyses revealed significantly greater improvements in the experimental group on the Full-Scale IQ, and the Verbal Comprehension, Perceptual Reasoning, and Working Memory indices, but not Processing Speed, compared to the PT group. Children in the experimental group showed an average WISC IQ gain of more than ten points. Results indicate that the WISC IQ scores of MLD children might be underestimated and that an effective math intervention can improve WISC IQ test performance. Taking limitations into account, we discuss the use of IQ measures more generally for defining MLD in research and practice. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Multidetector Computed Tomography and Neuroendocrine Pancreaticoduodenal Tumors

    International Nuclear Information System (INIS)

    Rappeport, E.D.; Palnaes Hansen, C.; Kjaer, A.; Knigge, U.

    2006-01-01

    Purpose: To investigate the accuracy of dedicated pancreatic multidetector computed tomography (MDCT) in the diagnosis of neuroendocrine pancreaticoduodenal tumors (NPTs). Material and Methods: MDCT and other imaging studies in patients with suspected NPTs were identified. Thirty dedicated MDCT studies were done in 23 patients. Fourteen patients (16 operations) subsequently had surgery. Imaging reports were reviewed and findings compared with surgical findings and findings in other imaging studies. Results: Patients with surgery : 19 NPTs (16 extrapancreatic gastrinomas and 3 pancreatic NPTs) were identified at surgery. MDCT identified 16 and somatostatin receptor scintigraphy (SRS) 11 out of 19 tumors. Endoscopic ultrasound detected 11 out of 14 NPTs. Patients without surgery : In 4 out of 9 patients, no NPTs were identified at MDCT. Conclusion: Dedicated MDCT of the pancreas can identify many NPTs, including small duodenal and periduodenal tumors, and the detection rate is better than reported in the older literature on CT

  19. Role of whole-body 64-slice multidetector computed tomography in treatment planning for multiple myeloma.

    Science.gov (United States)

    Razek, Ahmed Abdel Khalek Abdel; Ezzat, Amany; Azmy, Emad; Tharwat, Nehal

    2013-08-01

    The authors evaluated the role of whole-body 64-slice multidetector computed tomography (WB-MDCT) in treatment planning for multiple myeloma. This was a prospective study of 28 consecutive patients with multiple myeloma (19 men, nine women; age range, 51-73 years; mean age, 60 years) who underwent WB-MDCT and conventional radiography (CR) of the skeleton. The images were interpreted for the presence of bony lesions, medullary lesions, fractures and extraosseous lesions. We evaluated any changes in treatment planning as a result of WB-MDCT findings. WB-MDCT was superior to CR for detecting bony lesions (p=0.001), especially of the spine (p=0.001) and thoracic cage (p=0.006). WB-MDCT upstaged 14 patients, with a significant difference in staging (p=0.002) between WB-MDCT and CR. Medullary involvement either focal (n=6) or diffuse (n=3) had a positive correlation with the overall score (r=0.790) and stage (r=0.618) of disease. Spine fractures were better detected at WB-MDCT (n=4) than at CR (n=2). Extraosseous soft tissue lesions (n=7) were detected only at WB-MDCT. Findings detected at the WB-MDCT led to changes in the patient's treatment plan in 39% of cases. Upstaging of seven patients (25%) altered the medical treatment plan, and four of 28 (14%) patients required additional radiotherapy (7%) and vertebroplasty (7%). We conclude that WB-MDCT has an impact on treatment planning and prognosis in patients with multiple myeloma, as it has high rate of detecting cortical and medullary bone lesions, spinal fracture and extraosseous lesions. This information may alter treatment planning in multiple myeloma due to disease upstaging and detection of spine fracture and extraosseous spinal lesions.

  20. Multidetector-Row Computed Tomography in the Evaluation of Transjugular Intrahepatic Portosystemic Shunt Performed with Expanded-Polytetrafluoroethylene-Covered Stent-Graft

    International Nuclear Information System (INIS)

    Fanelli, Fabrizio; Bezzi, Mario; Bruni, Antonio; Corona, Mario; Boatta, Emanuele; Lucatelli, Pierleone; Passariello, Roberto

    2011-01-01

    We assessed, in a prospective study, the efficacy of multidetector spiral computed tomography (MDCT) in the evaluation of transjugular intrahepatic portosystemic shunt (TIPS) patency in patients treated with the Viatorr (Gore, Flagstaff, AZ) expanded-polytetrafluoroethylene (e-PTFE)-covered stent-graft. Eighty patients who underwent TIPS procedure using the Viatorr self-expanding e-PTFE stent-graft were evaluated at follow-up of 1, 3, 6, and 12 months with clinical and laboratory tests as well as ultrasound–color Doppler (USCD) imaging. In case of varices, upper gastrointestinal endoscopy was also performed. In addition, the shunt was evaluated using MDCT at 6 and 12 months. In all cases of abnormal findings and discrepancy between MDCT and USCD, invasive control venography was performed. MDCT images were acquired before and after injection of intravenous contrast media on the axial plane and after three-dimensional reconstruction using different algorithms. MDCT was successfully performed in all patients. No artefacts correlated to the Viatorr stent-graft were observed. A missing correlation between UCSD and MDCT was noticed in 20 of 80 (25%) patients. Invasive control venography confirmed shunt patency in 16 (80%) cases and shunt malfunction in 4 (20%) cases. According to these data, MDCT sensitivity was 95.2%; specificity was 96.6%; and positive (PPV) and negative predictive values (NPV) were 90.9 and 98.2%, respectively. USCD sensitivity was 90%; specificity was 75%; and PPV and NPV were 54.5 and 95.7%, respectively. A high correlation (K value = 0.85) between MDCT and invasive control venography was observed. On the basis of these results, MDCT shows superior sensitivity and specificity compared with USCD in those patients in whom TIPS was performed with the Viatorr stent-graft. MDCT can be considered a valid tool in the follow-up of these patients.

  1. Performance of cone-beam computed tomography and multidetector computed tomography in diagnostic imaging of the midface: A comparative study on Phantom and cadaver head scans

    Energy Technology Data Exchange (ETDEWEB)

    Veldhoen, Simon [University Medical Center Hamburg, Department of Diagnostic and Interventional Radiology, Hamburg (Germany); University Hospital Wuerzburg, Department of Diagnostic and Interventional Radiology, Wuerzburg (Germany); Schoellchen, Maximilian; Hanken, H.; Precht, C.; Heiland, M. [University Medical Center Hamburg, Department of Oral- and Maxillofacial Surgery, Hamburg (Germany); Henes, F.O.; Adam, G.; Regier, M. [University Medical Center Hamburg, Department of Diagnostic and Interventional Radiology, Hamburg (Germany); Schoen, G. [University Medical Center Hamburg, Department of Medical Biometry and Epidemiology, Hamburg (Germany); Nagel, H.D. [Science and Technology for Radiology, Buchholz (Germany); Schumacher, U. [University Medical Center Hamburg, Institute of Anatomy, Hamburg (Germany)

    2017-02-15

    To compare multidetector computed tomography (MDCT) and cone-beam computed tomography (CBCT) regarding radiation, resolution, image noise, and image quality. CBCT and 256-MDCT were compared based on three scan protocols: Standard-dose (∼24 mGy), reduced-dose (∼9 mGy), and low-dose (∼4 mGy). MDCT images were acquired in standard- and high-resolution mode (HR-MDCT) and reconstructed using filtered back projection (FBP) and iterative reconstruction (IR). Spatial resolution in linepairs (lp) and objective image noise (OIN) were assessed using dedicated phantoms. Image quality was assessed in scans of 25 cadaver heads using a Likert scale. OIN was markedly higher in FBP-MDCT when compared to CBCT. IR lowered the OIN to comparable values in standard-mode MDCT only. CBCT provided a resolution of 13 lp/cm at standard-dose and 11 lp/cm at reduced-dose vs. 11 lp/cm and 10 lp/cm in HR-MDCT. Resolution of 10 lp/cm was observed for both devices using low-dose settings. Quality scores of MDCT and CBCT did not differ at standard-dose (CBCT, 3.4; MDCT, 3.3-3.5; p > 0.05). Using reduced- and low-dose protocols, CBCT was superior (reduced-dose, 3.2 vs. 2.8; low dose, 3.0 vs. 2.3; p < 0.001). Using the low-dose protocol, the assessed CBCT provided better objective and subjective image quality and equality in resolution. Similar image quality, but better resolution using CBCT was observed at higher exposure settings. (orig.)

  2. Improved MDCT monitoring of pelvic myeloma bone disease through the use of a novel longitudinal bone subtraction post-processing algorithm

    Energy Technology Data Exchange (ETDEWEB)

    Horger, Marius; Thaiss, Wolfgang M.; Nikolaou, Konstantin; Kloth, Christopher [Eberhard-Karls-University Tuebingen, Department of Diagnostic and Interventional Radiology, Tuebingen (Germany); Ditt, Hendrik [Sector Imaging and Interventional Radiology, Siemens AG Healthcare, Forchheim (Germany); Weisel, Katja [Eberhard-Karls-University Tuebingen, Department of Internal Medicine II, Tuebingen (Germany); Fritz, Jan [Johns Hopkins University School of Medcine, Russell H. Morgan Department of Radiology and Radiological Science, Baltimore, MD (United States); Liao, Shu [Siemens Medical Solutions, Malvern, PA (United States)

    2017-07-15

    To evaluate the diagnostic performance of a novel CT post-processing software that generates subtraction maps of baseline and follow-up CT examinations in the course of myeloma bone lesions. This study included 61 consecutive myeloma patients who underwent repeated whole-body reduced-dose MDCT at our institution between November 2013 and June 2015. CT subtraction maps classified a progressive disease (PD) vs. stable disease (SD)/remission. Bone subtraction maps (BSMs) only and in combination with 1-mm (BSM+) source images were compared with 5-mm axial/MPR scans. Haematological response categories at follow-up were: complete remission (n = 9), very good partial remission (n = 2), partial remission (n = 17) and SDh (n = 19) vs. PDh (n = 14). Five-millimetre CT scan yielded PD (n = 14) and SD/remission (n = 47) whereas bone subtraction + 1-mm axial scans (BSM+) reading resulted in PD (n = 18) and SD/remission (n = 43). Sensitivity/ specificity/accuracy for 5-mm/1-mm/BSM(alone)/BSM + in ''lesion-by-lesion'' reading was 89.4 %/98.9 %/98.3 %/ 99.5 %; 69.1 %/96.9 %/72 %/92.1 % and 83.8 %/98.4 %/92.1 %/98.3 %, respectively. The use of BSM+ resulted in a change of response classification in 9.8 % patients (n = 6) from SD to PD. BSM reading is more accurate for monitoring myeloma compared to axial scans whereas BSM+ yields similar results with 1-mm reading (gold standard) but by significantly reduced reading time. (orig.)

  3. Improved MDCT monitoring of pelvic myeloma bone disease through the use of a novel longitudinal bone subtraction post-processing algorithm

    International Nuclear Information System (INIS)

    Horger, Marius; Thaiss, Wolfgang M.; Nikolaou, Konstantin; Kloth, Christopher; Ditt, Hendrik; Weisel, Katja; Fritz, Jan; Liao, Shu

    2017-01-01

    To evaluate the diagnostic performance of a novel CT post-processing software that generates subtraction maps of baseline and follow-up CT examinations in the course of myeloma bone lesions. This study included 61 consecutive myeloma patients who underwent repeated whole-body reduced-dose MDCT at our institution between November 2013 and June 2015. CT subtraction maps classified a progressive disease (PD) vs. stable disease (SD)/remission. Bone subtraction maps (BSMs) only and in combination with 1-mm (BSM+) source images were compared with 5-mm axial/MPR scans. Haematological response categories at follow-up were: complete remission (n = 9), very good partial remission (n = 2), partial remission (n = 17) and SDh (n = 19) vs. PDh (n = 14). Five-millimetre CT scan yielded PD (n = 14) and SD/remission (n = 47) whereas bone subtraction + 1-mm axial scans (BSM+) reading resulted in PD (n = 18) and SD/remission (n = 43). Sensitivity/ specificity/accuracy for 5-mm/1-mm/BSM(alone)/BSM + in ''lesion-by-lesion'' reading was 89.4 %/98.9 %/98.3 %/ 99.5 %; 69.1 %/96.9 %/72 %/92.1 % and 83.8 %/98.4 %/92.1 %/98.3 %, respectively. The use of BSM+ resulted in a change of response classification in 9.8 % patients (n = 6) from SD to PD. BSM reading is more accurate for monitoring myeloma compared to axial scans whereas BSM+ yields similar results with 1-mm reading (gold standard) but by significantly reduced reading time. (orig.)

  4. Visualization of coronary arteries in patients after childhood Kawasaki syndrome: value of multidetector CT and MR imaging in comparison to conventional coronary catheterization

    International Nuclear Information System (INIS)

    Arnold, Raoul; Ley, Sebastian; Ley-Zaporozhan, Julia; Kauczor, Hans-Ulrich; Eichhorn, Joachim; Ulmer, Herbert; Schenk, Jens-Peter

    2007-01-01

    After childhood Kawasaki syndrome (KS) the coronary arteries undergo a lifelong dynamic pathological change, and follow-up coronary artery imaging is essential. At present, conventional coronary catheterization (CCC) and angiography is still regarded as the gold standard. Less-invasive methods such as multidetector CT angiography (MDCT-A) and MRI have been used sporadically. To compare the diagnostic quality of MDCT-A and MRI with that of CCC for coronary imaging in a group of patients with coronary artery pathology after childhood KS. A total of 16 patients (aged 5-27 years) underwent CCC and 16-row MDCT-A and 14 patients MRI (1.5 T). There was 100% agreement between MDCT-A and CCC in the detection of coronary aneurysms and stenoses. MDCT-A was superior for the visualization of calcified lesions. MRI and CCC showed 93% agreement for the detection of aneurysms. Visualization of coronary artery stenoses was difficult using MRI - one stenosis was missed. MDCT-A has excellent correlation with CCC regarding all changes affecting the coronary arteries in the follow-up of childhood KS. In comparison to MDCT-A and CCC, MRI is less precise in the detection of stenotic lesions. Due to its high image quality and ease of performance MDCT-A should be the primary diagnostic modality in patients following childhood KS. (orig.)

  5. Global models underestimate large decadal declining and rising water storage trends relative to GRACE satellite data

    Science.gov (United States)

    Scanlon, Bridget R.; Zhang, Zizhan; Save, Himanshu; Sun, Alexander Y.; van Beek, Ludovicus P. H.; Wiese, David N.; Reedy, Robert C.; Longuevergne, Laurent; Döll, Petra; Bierkens, Marc F. P.

    2018-01-01

    Assessing reliability of global models is critical because of increasing reliance on these models to address past and projected future climate and human stresses on global water resources. Here, we evaluate model reliability based on a comprehensive comparison of decadal trends (2002–2014) in land water storage from seven global models (WGHM, PCR-GLOBWB, GLDAS NOAH, MOSAIC, VIC, CLM, and CLSM) to trends from three Gravity Recovery and Climate Experiment (GRACE) satellite solutions in 186 river basins (∼60% of global land area). Medians of modeled basin water storage trends greatly underestimate GRACE-derived large decreasing (≤−0.5 km3/y) and increasing (≥0.5 km3/y) trends. Decreasing trends from GRACE are mostly related to human use (irrigation) and climate variations, whereas increasing trends reflect climate variations. For example, in the Amazon, GRACE estimates a large increasing trend of ∼43 km3/y, whereas most models estimate decreasing trends (−71 to 11 km3/y). Land water storage trends, summed over all basins, are positive for GRACE (∼71–82 km3/y) but negative for models (−450 to −12 km3/y), contributing opposing trends to global mean sea level change. Impacts of climate forcing on decadal land water storage trends exceed those of modeled human intervention by about a factor of 2. The model-GRACE comparison highlights potential areas of future model development, particularly simulated water storage. The inability of models to capture large decadal water storage trends based on GRACE indicates that model projections of climate and human-induced water storage changes may be underestimated. PMID:29358394

  6. Multidetector-row computed tomography for the preoperative evaluation of axillary nodal status in patients with breast cancer

    International Nuclear Information System (INIS)

    Ogasawara, Yutaka; Doihara, Hiroyoshi; Shiraiwa, Misaki; Ishihara, Setsuko

    2008-01-01

    We evaluated the effectiveness of multidetector-row computed tomography (MD-CT) for detecting axillary lymph nodal status (ALNS) in patients with breast cancer. We reviewed 42 patients with breast cancer. A metastatic lymph node on MD-CT was defined as oval or round, with more than 5 mm on the short axis. We evaluated ALNS preoperatively by both palpation and MD-CT findings and performed sentinel lymph node biopsy (SLNB) and complete axillary lymph node dissection (ALND). For establishing the ALNS, MD-CT showed a sensitivity of 76.9%, a specificity of 96.6%, and an accuracy of 90.5%. On the basis of the MD-CT findings, misdiagnosis was made in 4 of the 42 patients, only one of which was false positive. On the other hand, one patient with a histologically negative sentinel lymph node (SLN) result had metastasis only in a non-SLN. Preoperative MD-CT showed a positive node in this patient. Multidetector-row computed tomography assists in identifying women who require ALND without SLNB, with sufficient positive predictive value. False-negative detection by SLNB could be avoided with careful interpretation of the axillary lymph nodes shown by MD-CT. (author)

  7. Optimization of 64-MDCT urography: effect of dual-phase imaging with furosemide on collecting system opacification and radiation dose.

    Science.gov (United States)

    Portnoy, Orith; Guranda, Larisa; Apter, Sara; Eiss, David; Amitai, Marianne Michal; Konen, Eli

    2011-11-01

    The purpose of this study was to compare opacification of the urinary collecting system and radiation dose associated with three-phase 64-MDCT urographic protocols and those associated with a split-bolus dual-phase protocol including furosemide. Images from 150 CT urographic examinations performed with three scanning protocols were retrospectively evaluated. Group A consisted of 50 sequentially registered patients who underwent a three-phase protocol with saline infusion. Group B consisted of 50 sequentially registered patients who underwent a reduced-radiation three-phase protocol with saline. Group C consisted of 50 sequentially registered patients who underwent a dual-phase split-bolus protocol that included a low-dose furosemide injection. Opacification of the urinary collecting system was evaluated with segmental binary scoring. Contrast artifacts were evaluated, and radiation doses were recorded. Results were compared by analysis of variance. A significant reduction in mean effective radiation dose was found between groups A and B (p < 0.001) and between groups B and C (p < 0.001), resulting in 65% reduction between groups A and C (p < 0.001). This reduction did not significantly affect opacification score in any of the 12 urinary segments (p = 0.079). In addition, dense contrast artifacts overlying the renal parenchyma observed with the three-phase protocols (groups A and B) were avoided with the dual-phase protocol (group C) (p < 0.001). A dual-phase protocol with furosemide injection is the preferable technique for CT urography. In comparison with commonly used three-phase protocols, the dual-phase protocol significantly reduces radiation exposure dose without reduction in image quality.

  8. MDCT in the Differentiation of Adrenal Masses: Comparison between Different Scan Delays for the Evaluation of Intralesional Washout

    Directory of Open Access Journals (Sweden)

    Giuseppe Angelelli

    2013-01-01

    Full Text Available Purpose. To evaluate the accuracy of the washout in the differential diagnosis between adenomas and nonadenomas and to compare the obtained results in delayed CT scans at 5, 10 and 15 minutes. Methods. Fifty patients with adrenal masses were prospectively evaluated. CT scans were performed by using a 320-row MDCT device, before and after injection of contrast material. In 25 cases, delayed scans were performed at 5′ and 10′ (group 1, while in the remaining 25, at 5′ and 15′ (group 2. Absolute and relative wash-out percentage values (APW and RPW were calculated. Results. Differential diagnosis between adenomas and nonadenomas was obtained in 48/50 (96% cases, with sensitivity, specificity, and accuracy values of 96%, 95%, and 96%, respectively. In group 1, APW and RPW values were, respectively, 69.8% and 67.2% at 5′ and 75.9% and 73.5% at 10′ for adenomas and 25.1% and 15.8% at 5′ and 33.5% and 20.5% at 10′ for nonadenomas. In group 2, APW and RPW values were 63% and 54.6% at 5′ and 73.8% and 65.5% at 15′ for adenomas and 22% and 12.5% at 5′ and 35.5% and 19.9% at 15′ for nonadenomas. Conclusions. The evaluation of the wash-out values in CT scans performed at 5′, 10′, and 15′ provides comparable diagnostic results. CT scans performed at 5′ are, therefore, to be preferred, since they reduce the examination time and patient discomfort.

  9. MDCT assessment of airway wall thickness in COPD patients using a new method: correlations with pulmonary function tests

    International Nuclear Information System (INIS)

    Achenbach, Tobias; Weinheimer, Oliver; Schmitt, Sabine; Freudenstein, Daniela; Kunz, Richard Peter; Dueber, Christoph; Biedermann, Alexander; Buhl, Roland; Goutham, Edula; Heussel, Claus Peter

    2008-01-01

    Quantitative assessment of airway-wall dimensions by computed tomography (CT) has proven to be a marker of airway-wall remodelling in chronic obstructive pulmonary disease (COPD) patients. The objective was to correlate the wall thickness of large and small airways with functional parameters of airflow obstruction in COPD patients on multi-detector (MD) CT images using a new quantification procedure from a three-dimensional (3D) approach of the bronchial tree. In 31 patients (smokers/COPD, non-smokers/controls), we quantitatively assessed contiguous MDCT cross-sections reconstructed orthogonally along the airway axis, taking the point-spread function into account to circumvent over-estimation. Wall thickness and wall percentage were measured and the per-patient mean/median correlated with FEV1 and FEV1%. A median of 619 orthogonal airway locations was assessed per patient. Mean wall percentage/mean wall thickness/median wall thickness in non-smokers (29.6%/0.69 mm/0.37 mm) was significantly different from the COPD group (38.9%/0.83 mm/0.54 mm). Correlation coefficients (r) between FEV1 or FEV1% predicted and intra-individual means of the wall percentage were -0.569 and -0.560, respectively, with p<0.001. Depending on the parameter, they were increased for airways of 4 mm and smaller in total diameter, being -0.621 (FEV1) and -0.537 (FEV1%) with p < 0.002. The wall thickness was significantly higher in smokers than in non-smokers. In COPD patients, the wall thickness measured as a mean for a given patient correlated with the values of FEV1 and FEV1% predicted. Correlation with FEV1 was higher when only small airways were considered. (orig.)

  10. A general method dealing with correlations in uncertainty propagation in fault trees

    International Nuclear Information System (INIS)

    Qin Zhang

    1989-01-01

    This paper deals with the correlations among the failure probabilities (frequencies) of not only the identical basic events but also other basic events in a fault tree. It presents a general and simple method to include these correlations in uncertainty propagation. Two examples illustrate this method and show that neglecting these correlations results in large underestimation of the top event failure probability (frequency). One is the failure of the primary pump in a chemical reactor cooling system, the other example is an accident to a road transport truck carrying toxic waste. (author)

  11. Does Computed Tomography Change our Observation and Management of Fracture Non-Unions?

    Directory of Open Access Journals (Sweden)

    Ydo V. Kleinlugtenbelt

    2016-10-01

    In this study, the interobserver reliability of MDCT scan is not greater than conventional radiographs for determining non-union. However, a MDCT scan did lead to a more invasive approach in equivocal cases. Therefore a MDCT is only recommended for making treatment strategies in those cases.

  12. Detection and localization of acute upper and lower gastrointestinal (GI) bleeding with arterial phase multi-detector row helical CT

    Energy Technology Data Exchange (ETDEWEB)

    Jaeckle, T.; Stuber, G.; Hoffmann, M.H.K.; Jeltsch, M.; Schmitz, B.L.; Aschoff, A.J. [University Hospital of Ulm, Diagnostic and Interventional Radiology, Ulm (Germany)

    2008-07-15

    The purpose of this study was to evaluate the accuracy of multi-detector row helical CT (MDCT) for detection and localization of acute upper and lower gastrointestinal (GI) hemorrhage or intraperitoneal bleeding. Thirty-six consecutive patients with clinical signs of acute bleeding underwent biphasic (16- or 40-channel) MDCT. MDCT findings were correlated with endoscopy, angiography or surgery. Among the 36 patients evaluated, 26 were examined for GI bleeding and 10 for intraperitoneal hemorrhage. Confirmed sites of GI bleeding were the stomach (n = 5), duodenum (n = 5), small bowel (n = 6), large bowel (n = 8) and rectum (n = 2). The correct site of bleeding was identifiable on MDCT in 24/26 patients with GI bleeding. In 20 of these 24 patients, active CM extravasation was apparent during the exam. Among the ten patients with intraperitoneal hemorrhage, MDCT correctly identified the bleeding source in nine patients. Our findings suggest that fast and accurate localization of acute gastrointestinal and intraperitoneal bleeding is achievable on MDCT. (orig.)

  13. Detection and localization of acute upper and lower gastrointestinal (GI) bleeding with arterial phase multi-detector row helical CT

    International Nuclear Information System (INIS)

    Jaeckle, T.; Stuber, G.; Hoffmann, M.H.K.; Jeltsch, M.; Schmitz, B.L.; Aschoff, A.J.

    2008-01-01

    The purpose of this study was to evaluate the accuracy of multi-detector row helical CT (MDCT) for detection and localization of acute upper and lower gastrointestinal (GI) hemorrhage or intraperitoneal bleeding. Thirty-six consecutive patients with clinical signs of acute bleeding underwent biphasic (16- or 40-channel) MDCT. MDCT findings were correlated with endoscopy, angiography or surgery. Among the 36 patients evaluated, 26 were examined for GI bleeding and 10 for intraperitoneal hemorrhage. Confirmed sites of GI bleeding were the stomach (n = 5), duodenum (n = 5), small bowel (n = 6), large bowel (n = 8) and rectum (n = 2). The correct site of bleeding was identifiable on MDCT in 24/26 patients with GI bleeding. In 20 of these 24 patients, active CM extravasation was apparent during the exam. Among the ten patients with intraperitoneal hemorrhage, MDCT correctly identified the bleeding source in nine patients. Our findings suggest that fast and accurate localization of acute gastrointestinal and intraperitoneal bleeding is achievable on MDCT. (orig.)

  14. Radiation dosimetry and its influencing factors for the multi-detector/slice spiral CT

    International Nuclear Information System (INIS)

    Bai Mei; Zheng Junzheng

    2008-01-01

    The Multi-Detector/Slice Spiral Computed Tomography (MDCT/MSCT)reflects the new progress in equipment and technology for radiology. Its popularized application demonstrates its advantages for clinical diagnosis. With the continuous development and growing uses of the MDCT/MSCT, the medical exposure of the patients and public has also been increasing. Therefore, assessment of the radiation dose and radiation risk from X-CT has become an increasingly important concern that should be addressed. Thus, this paper summarizes the main characteristics of the MDCT/MSCT emphasizing particularly on the radiation dosimetry, and reviews the expressions and measures of radiation dose in the MDCT/MSCT. In addition, main factors that influence radiation dose from the MDCT/MSCT are also discussed. A proper grasp of its radiation dosimetry and assessment method can significantly help radiologists, health physicists, medical physicists, X-CT engineers and manufacturers improve the management of radiation dose while optimizing the image quality in the MDCT/MSCT. (authors)

  15. College Students' Underestimation of Blood Alcohol Concentration from Hypothetical Consumption of Supersized Alcopops: Results from a Cluster-Randomized Classroom Study.

    Science.gov (United States)

    Rossheim, Matthew E; Thombs, Dennis L; Krall, Jenna R; Jernigan, David H

    2018-05-30

    Supersized alcopops are a class of single-serving beverages popular among underage drinkers. These products contain large quantities of alcohol. This study examines the extent to which young adults recognize how intoxicated they would become from consuming these products. The study sample included 309 undergraduates who had consumed alcohol within the past year. Thirty-two sections of a college English course were randomized to 1 of 2 survey conditions, based on hypothetical consumption of supersized alcopops or beer of comparable liquid volume. Students were provided an empty can of 1 of the 2 beverages to help them answer the survey questions. Equation-calculated blood alcohol concentrations (BACs)-based on body weight and sex-were compared to the students' self-estimated BACs for consuming 1, 2, and 3 cans of the beverage provided to them. In adjusted regression models, students randomized to the supersized alcopop group greatly underestimated their BAC, whereas students randomized to the beer group overestimated it. The supersized alcopop group underestimated their BAC by 0.04 (95% confidence interval [CI]: 0.034, 0.053), 0.09 (95% CI: 0.067, 0.107), and 0.13 g/dl (95% CI: 0.097, 0.163) compared to the beer group. When asked how much alcohol they could consume before it would be unsafe to drive, students in the supersized alcopop group had 7 times the odds of estimating consumption that would generate a calculated BAC of at least 0.08 g/dl, compared to those making estimates based on beer consumption (95% CI: 3.734, 13.025). Students underestimated the intoxication they would experience from consuming supersized alcopops. Revised product warning labels are urgently needed to clearly identify the number of standard drinks contained in a supersized alcopop can. Moreover, regulations are needed to limit alcohol content of single-serving products. Copyright © 2018 by the Research Society on Alcoholism.

  16. Disclosing bias in bisulfite assay: MethPrimers underestimate high DNA methylation.

    Directory of Open Access Journals (Sweden)

    Andrea Fuso

    Full Text Available Discordant results obtained in bisulfite assays using MethPrimers (PCR primers designed using MethPrimer software or assuming that non-CpGs cytosines are non methylated versus primers insensitive to cytosine methylation lead us to hypothesize a technical bias. We therefore used the two kinds of primers to study different experimental models and methylation statuses. We demonstrated that MethPrimers negatively select hypermethylated DNA sequences in the PCR step of the bisulfite assay, resulting in CpG methylation underestimation and non-CpG methylation masking, failing to evidence differential methylation statuses. We also describe the characteristics of "Methylation-Insensitive Primers" (MIPs, having degenerated bases (G/A to cope with the uncertain C/U conversion. As CpG and non-CpG DNA methylation patterns are largely variable depending on the species, developmental stage, tissue and cell type, a variable extent of the bias is expected. The more the methylome is methylated, the greater is the extent of the bias, with a prevalent effect of non-CpG methylation. These findings suggest a revision of several DNA methylation patterns so far documented and also point out the necessity of applying unbiased analyses to the increasing number of epigenomic studies.

  17. Using cone-beam CT as a low-dose 3D imaging technique for the extremities: initial experience in 50 subjects

    International Nuclear Information System (INIS)

    Huang, Ambrose J.; Chang, Connie Y.; Palmer, William E.; Thomas, Bijoy J.; MacMahon, Peter J.

    2015-01-01

    To prospectively evaluate a dedicated extremity cone-beam CT (CBCT) scanner in cases with and without orthopedic hardware by (1) comparing its imaging duration and image quality to those of radiography and multidetector CT (MDCT) and (2) comparing its radiation dose to that of MDCT. Written informed consent was obtained for all subjects for this IRB-approved, HIPAA-compliant study. Fifty subjects with (1) fracture of small bones, (2) suspected intraarticular fracture, (3) fracture at the site of complex anatomy, or (4) a surgical site difficult to assess with radiography alone were recruited and scanned on an extremity CBCT scanner prior to FDA approval. Same-day radiographs were performed in all subjects. Some subjects also underwent MDCT within 1 month of CBCT. Imaging duration and image quality were compared between CBCT and radiographs. Imaging duration, effective radiation dose, and image quality were compared between CBCT and MDCT. Fifty-one CBCT scans were performed in 50 subjects. Average imaging duration was shorter for CBCT than radiographs (4.5 min vs. 6.6 min, P = 0.001, n = 51) and MDCT (7.6 min vs. 10.9 min, P = 0.01, n = 7). Average estimated effective radiation dose was less for CBCT than MDCT (0.04 mSv vs. 0.13 mSv, P = 0.02, n = 7). CBCT images yielded more diagnostic information than radiographs in 23/51 cases and more diagnostic information than MDCT in 1/7 cases, although radiographs were superior for detecting hardware complications. CBCT performs high-resolution imaging of the extremities using less imaging time than radiographs and MDCT and lower radiation dose than MDCT. (orig.)

  18. Multidetector computed tomography for preoperative evaluation of vascular anatomy in living renal donors.

    Science.gov (United States)

    Türkvatan, Aysel; Akinci, Serkan; Yildiz, Sener; Olçer, Tülay; Cumhur, Turhan

    2009-04-01

    Currently, multidetector computed tomographic (MDCT) angiography has become a noninvasive alternative imaging modality to catheter renal angiography for the evaluation of renal vascular anatomy in living renal donors. In this study, we investigated the diagnostic accuracy of 16-slice MDCT in the preoperative assessment of living renal donors. Fifty-nine consecutive living renal donors (32 men, 27 women) underwent MDCT angiography followed by open donor nephrectomy. All MDCT studies were performed by using a 16-slice MDCT scanner with the same protocol consisting of arterial and nephrographic phases followed by conventional abdominal radiography. The MDCT images were assessed retrospectively for the number and branching pattern of the renal arteries and for the number and presence of major or minor variants of the renal veins. The results were compared with open surgical results. The sensitivity and specificity of MDCT for the detection of anatomic variants of renal arteries including the accessory arteries (n = 9), early arterial branching (n = 7) and major renal venous anomalies including the accessory renal veins (n = 3), late venous confluence (n = 4), circumaortic (n = 2) or retroaortic (n = 3) left renal veins were 100%. However, the sensitivity for identification of minor venous variants was 79%. All of three ureteral duplications were correctly identified at excretory phase conventional abdominal radiography. Sixteen-slice MDCT is highly accurate for the identification of anatomic variants of renal arteries and veins. Dual-phase MDCT angiography including arterial and nephrographic phases followed by conventional abdominal radiography enables complete assessment of renal donors without significant increase of radiation dose. However, the evaluation of minor venous variants may be problematic because of their small diameters and poor opacification.

  19. [Comparison of radiation dose reduction of prospective ECG-gated one beat scan using 320 area detector CT coronary angiography and prospective ECG-gated helical scan with high helical pitch (FlashScan) using 64 multidetector-row CT coronary angiography].

    Science.gov (United States)

    Matsutani, Hideyuki; Sano, Tomonari; Kondo, Takeshi; Fujimoto, Shinichiro; Sekine, Takako; Arai, Takehiro; Morita, Hitomi; Takase, Shinichi

    2010-12-20

    A high radiation dose associated with 64 multidetector-row computed tomography (64-MDCT) is a major concern for physicians and patients alike. A new 320 row area detector computed tomography (ADCT) can obtain a view of the entire heart with one rotation (0.35 s) without requiring the helical method. As such, ADCT is expected to reduce the radiation dose. We studied image quality and radiation dose of ADCT compared to that of 64-MDCT in patients with a low heart rate (HR≤60). Three hundred eighty-five consecutive patients underwent 64-MDCT and 379 patients, ADCT. Patients with an arrhythmia were excluded. Prospective ECG-gated helical scan with high HP (FlashScan) in 64 was used for MDCT and prospective ECG-gated conventional one beat scan, for 320-ADCT. Image quality was visually evaluated by an image quality score. Radiation dose was estimated by DLP (mGy・cm) for 64-MDCT and DLP.e (mGy・cm) for 320-ADCT. Radiation dose of 320-ADCT (208±48 mGy・cm) was significantly (P<0.0001) lower than that of 64-MDCT (484±112 mGy・cm), and image quality score of 320-ADCT (3.0±0.2) was significantly (P=0.0011) higher than that of 64-MDCT (2.9±0.4). Scan time of 320-ADCT (1.4±0.1 s) was also significantly (P<0.0001) shorter than that of 64-MDCT (6.8±0.6 s). 320-ADCT can achieve not only a reduction in radiation dose but also a superior image quality and shortening of scan time compared to 64-MDCT.

  20. Using cone-beam CT as a low-dose 3D imaging technique for the extremities: initial experience in 50 subjects

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Ambrose J.; Chang, Connie Y.; Palmer, William E. [Massachusetts General Hospital, Department of Radiology, Division of Musculoskeletal Imaging and Intervention, Boston, MA (United States); Thomas, Bijoy J. [Universal College of Medical Sciences, Department of Radiology, Bhairahawa (Nepal); MacMahon, Peter J. [Mater Misericordiae University Hospital, Department of Radiology, Dublin 7 (Ireland)

    2015-06-01

    To prospectively evaluate a dedicated extremity cone-beam CT (CBCT) scanner in cases with and without orthopedic hardware by (1) comparing its imaging duration and image quality to those of radiography and multidetector CT (MDCT) and (2) comparing its radiation dose to that of MDCT. Written informed consent was obtained for all subjects for this IRB-approved, HIPAA-compliant study. Fifty subjects with (1) fracture of small bones, (2) suspected intraarticular fracture, (3) fracture at the site of complex anatomy, or (4) a surgical site difficult to assess with radiography alone were recruited and scanned on an extremity CBCT scanner prior to FDA approval. Same-day radiographs were performed in all subjects. Some subjects also underwent MDCT within 1 month of CBCT. Imaging duration and image quality were compared between CBCT and radiographs. Imaging duration, effective radiation dose, and image quality were compared between CBCT and MDCT. Fifty-one CBCT scans were performed in 50 subjects. Average imaging duration was shorter for CBCT than radiographs (4.5 min vs. 6.6 min, P = 0.001, n = 51) and MDCT (7.6 min vs. 10.9 min, P = 0.01, n = 7). Average estimated effective radiation dose was less for CBCT than MDCT (0.04 mSv vs. 0.13 mSv, P = 0.02, n = 7). CBCT images yielded more diagnostic information than radiographs in 23/51 cases and more diagnostic information than MDCT in 1/7 cases, although radiographs were superior for detecting hardware complications. CBCT performs high-resolution imaging of the extremities using less imaging time than radiographs and MDCT and lower radiation dose than MDCT. (orig.)

  1. Improved vessel morphology measurements in contrast-enhanced multi-detector computed tomography coronary angiography with non-linear post-processing

    International Nuclear Information System (INIS)

    Ferencik, Maros; Lisauskas, Jennifer B.; Cury, Ricardo C.; Hoffmann, Udo; Abbara, Suhny; Achenbach, Stephan; Karl, W. Clem; Brady, Thomas J.; Chan, Raymond C.

    2006-01-01

    Multi-detector computed tomography (MDCT) permits detection of coronary plaque. However, noise and blurring impair accuracy and precision of plaque measurements. The aim of the study was to evaluate MDCT post-processing based on non-linear image deblurring and edge-preserving noise suppression for measurements of plaque size. Contrast-enhanced MDCT coronary angiography was performed in four subjects (mean age 55 ± 5 years, mean heart rate 54 ± 5 bpm) using a 16-slice scanner (Siemens Sensation 16, collimation 16 x 0.75 mm, gantry rotation 420 ms, tube voltage 120 kV, tube current 550 mAs, 80 mL of contrast). Intravascular ultrasound (IVUS; 40 MHz probe) was performed in one vessel in each patient and served as a reference standard. MDCT vessel cross-sectional images (1 mm thickness) were created perpendicular to centerline and aligned with corresponding IVUS images. MDCT images were processed using a deblurring and edge-preserving noise suppression algorithm. Then, three independent blinded observers segmented lumen and outer vessel boundaries in each modality to obtain vessel cross-sectional area and wall area in the unprocessed MDCT cross-sections, post-processed MDCT cross-sections and corresponding IVUS. The wall area measurement difference for unprocessed and post-processed MDCT images relative to IVUS was 0.4 ± 3.8 mm 2 and -0.2 ± 2.2 mm 2 (p 2 , respectively. In conclusion, MDCT permitted accurate in vivo measurement of wall area and vessel cross-sectional area as compared to IVUS. Post-processing to reduce blurring and noise reduced variability of wall area measurements and reduced measurement bias for both wall area and vessel cross-sectional area

  2. Accurate determination of high-risk coronary lesion type by multidetector cardiac computed tomography.

    Science.gov (United States)

    Alasnag, Mirvat; Umakanthan, Branavan; Foster, Gary P

    2008-07-01

    Coronary arteriography (CA) is the standard method to image coronary lesions. Multidetector cardiac computerized tomography (MDCT) provides high-resolution images of coronary arteries, allowing a noninvasive alternative to determine lesion type. To date, no studies have assessed the ability of MDCT to categorize coronary lesion types. The objective of this study was to determine the accuracy of lesion type categorization by MDCT using CA as a reference standard. Patients who underwent both MDCT and CA within 2 months of each other were enrolled. MDCT and CA images were reviewed in a blinded fashion. Lesions were categorized according to the SCAI classification system (Types I-IV). The origin, proximal and middle segments of the major arteries were analyzed. Each segment comprised a data point for comparison. Analysis was performed using the Spearman Correlation Test. Four hundred eleven segments were studied, of which 110 had lesions. The lesion distribution was as follows: 35 left anterior descending (LAD), 29 circumflex (Cx), 31 right coronary artery (RCA), 2 ramus intermedius, 8 diagonal, 4 obtuse marginal and 2 left internal mammary arteries. Correlations between MDCT and CA were significant in all major vessels (LAD, Cx, RCA) (p < 0.001). The overall correlation coefficient was 0.67. Concordance was strong for lesion Types II-IV (97%) and poor for Type I (30%). High-risk coronary lesion types can be accurately categorized by MDCT. This ability may allow MDCT to play an important noninvasive role in the planning of coronary interventions.

  3. Anterior atlantodental and posterior atlantodental intervals on plain radiography, multidetector CT, and MRI

    Energy Technology Data Exchange (ETDEWEB)

    Cha, Seung Woo; Ryu, Jeong Ah; Park, Dong Woo [Dept. of Radiology, Hanyang University Guri Hospital, Hanyang University College of Medicine, Guri (Korea, Republic of); Yoon, Ki Bo; Lee, Seung Hun; Joo, Kyung Bin [Dept. of Radiology, Hanyang University Seoul Hospital, Hanyang University College of Medicine, Seoul(Korea, Republic of)

    2015-01-15

    To determine the normal values of the anterior atlantodental interval (AADI) and posterior atlantodental interval (PADI) on plain radiography, multidetector CT (MDCT) and MRI, as well as the dural sac width and spinal cord diameter at the atlantoaxial joint level on MRI. In total, 60 subjects underwent plain radiography, MRI and MDCT. We obtained values for AADI and PADI on plain radiography, MDCT, and MRI, and for dural sac width and spinal cord diameter on MRI. Two radiologists independently measured each value and a consensus was reached. The average AADI was 1.5 +/- 0.5 mm on plain radiography, 1.4 +/- 0.3 mm on MDCT, and 1.6 +/- 0.5 mm on MRI. The average PADI was 20.6 +/- 2.4 mm on plain radiography, 18.0 +/- 2.1 mm on MDCT, and 17.7 +/- 1.9 mm on MRI. The dural sac width was 13.7 +/- 1.8 mm, and the spinal cord diameter was 7.8 +/- 0.7 mm. Interobserver agreement was 0.701-0.927 and intraobserver agreement was 0.681-0.937. AADI values obtained on MDCT are significantly lower than those obtained on plain radiography or MRI. PADI values obtained on plain radiography are significantly higher than those obtained on MDCT or MRI. The dural sac width is most closely correlated with PADI values on MDCT. PADI seems to be easier to measure, more relevant, and clinically useful than AADI.

  4. Anterior atlantodental and posterior atlantodental intervals on plain radiography, multidetector CT, and MRI

    International Nuclear Information System (INIS)

    Cha, Seung Woo; Ryu, Jeong Ah; Park, Dong Woo; Yoon, Ki Bo; Lee, Seung Hun; Joo, Kyung Bin

    2015-01-01

    To determine the normal values of the anterior atlantodental interval (AADI) and posterior atlantodental interval (PADI) on plain radiography, multidetector CT (MDCT) and MRI, as well as the dural sac width and spinal cord diameter at the atlantoaxial joint level on MRI. In total, 60 subjects underwent plain radiography, MRI and MDCT. We obtained values for AADI and PADI on plain radiography, MDCT, and MRI, and for dural sac width and spinal cord diameter on MRI. Two radiologists independently measured each value and a consensus was reached. The average AADI was 1.5 +/- 0.5 mm on plain radiography, 1.4 +/- 0.3 mm on MDCT, and 1.6 +/- 0.5 mm on MRI. The average PADI was 20.6 +/- 2.4 mm on plain radiography, 18.0 +/- 2.1 mm on MDCT, and 17.7 +/- 1.9 mm on MRI. The dural sac width was 13.7 +/- 1.8 mm, and the spinal cord diameter was 7.8 +/- 0.7 mm. Interobserver agreement was 0.701-0.927 and intraobserver agreement was 0.681-0.937. AADI values obtained on MDCT are significantly lower than those obtained on plain radiography or MRI. PADI values obtained on plain radiography are significantly higher than those obtained on MDCT or MRI. The dural sac width is most closely correlated with PADI values on MDCT. PADI seems to be easier to measure, more relevant, and clinically useful than AADI.

  5. Utilization of low-dose multidetector CT and virtual bronchoscopy in children with suspected foreign body aspiration

    International Nuclear Information System (INIS)

    Adaletli, Ibrahim; Kurugoglu, Sebuh; Ulus, Sila; Ozer, Harun; Kantarci, Fatih; Mihmanli, Ismail; Akman, Canan; Elicevik, Mehmet

    2007-01-01

    Foreign body aspiration is common in children, especially those under 3 years of age. Chest radiography and CT are the main imaging modalities for the evaluation of these children. Management of children with suspected foreign body aspiration (SFBA) mainly depends on radiological findings. To investigate the potential use of low-dose multidetector CT (MDCT) and virtual bronchoscopy (VB) in the evaluation and management of SFBA in children. Included in the study were 37 children (17 girls, 20 boys; age 4 months to 10 years, mean 32 months) with SFBA. Chest radiographs were obtained prior to MDCT in all patients. MDCT was performed using a low-dose technique. VB images were obtained in the same session. Conventional bronchoscopy (CB) was performed within 24 h on patients in whom an obstructive abnormality had been found by MDCT and VB. Obstructive pathology was found in 16 (43.25%) of the 37 patients using MDCT and VB. In 13 of these patients, foreign bodies were detected and removed via CB. The foreign bodies were located in the right main bronchus (n = 5), in the bronchus intermedius (n = 6), in the medial segment of the middle lobe bronchus (n = 1), and in the left main bronchus (n = 1). In the remaining three patients, the diagnosis was false-positive for an obstructive pathology by MDCT and VB; the final diagnoses were secretions (n = 2) and schwannoma (n = 1), as demonstrated by CB. In 21 patients in whom no obstructive pathology was detected by MDCT and VB, CB was not performed. These patients were followed for 5-20 months without any recurrent obstructive symptomatology. Low-dose MDCT and VB are non-invasive radiological modalities that can be used easily in the investigation of SFBA in children. MDCT and VB provide the exact location of the obstructive pathology prior to CB. If obstructive pathology is depicted with MDCT and VB, CB should be performed either for confirmation of the diagnosis or for the diagnosis of an alternative cause for the obstruction

  6. Detection of pulmonary embolism with combined ventilation-perfusion SPECT and low-dose CT: head-to-head comparison with multidetector CT angiography

    DEFF Research Database (Denmark)

    Gutte, Henrik; Mortensen, Jann; Jensen, Claus Verner

    2009-01-01

    The diagnosis of pulmonary embolism (PE) is usually established by a combination of clinical assessment, D-dimer testing, and imaging with either pulmonary ventilation-perfusion (V/Q) scintigraphy or pulmonary multidetector CT (MDCT) angiography. Both V/Q SPECT and MDCT angiography seem to have...... high diagnostic accuracy. However, only limited data directly comparing these 2 modalities are available. Hybrid gamma-camera/MDCT systems have been introduced and allow simultaneous 3-dimensional lung V/Q SPECT and MDCT angiography, suitable for diagnosing PE. The aim of our study was to compare...

  7. Multidetector CT in children: current concepts and dose reduction strategies

    Energy Technology Data Exchange (ETDEWEB)

    Nievelstein, Rutger A.J.; Dam, Ingrid M. van [University Medical Centre Utrecht, Department of Pediatric Radiology, Wilhelmina Children' s Hospital, E01.132, P.O. Box 85500, Utrecht (Netherlands); Molen, Aart J. van der [Leiden University Medical Centre, Department of Radiology, C-2S, Leiden (Netherlands)

    2010-08-15

    The recent technical development of multidetector CT (MDCT) has contributed to a substantial increase in its diagnostic applications and accuracy in children. A major drawback of MDCT is the use of ionising radiation with the risk of inducing secondary cancer. Therefore, justification and optimisation of paediatric MDCT is of great importance in order to minimise these risks (''as low as reasonably achievable'' principle). This review will focus on all technical and non-technical aspects relevant for paediatric MDCT optimisation and includes guidelines for radiation dose level-based CT protocols. (orig.)

  8. Multidetector CT in children: current concepts and dose reduction strategies

    International Nuclear Information System (INIS)

    Nievelstein, Rutger A.J.; Dam, Ingrid M. van; Molen, Aart J. van der

    2010-01-01

    The recent technical development of multidetector CT (MDCT) has contributed to a substantial increase in its diagnostic applications and accuracy in children. A major drawback of MDCT is the use of ionising radiation with the risk of inducing secondary cancer. Therefore, justification and optimisation of paediatric MDCT is of great importance in order to minimise these risks (''as low as reasonably achievable'' principle). This review will focus on all technical and non-technical aspects relevant for paediatric MDCT optimisation and includes guidelines for radiation dose level-based CT protocols. (orig.)

  9. Prediction of Periodontitis Occurrence: Influence of Classification and Sociodemographic and General Health Information

    DEFF Research Database (Denmark)

    Manzolli Leite, Fabio Renato; Peres, Karen Glazer; Do, Loc Giang

    2017-01-01

    BACKGROUND: Prediction of periodontitis development is challenging. Use of oral health-related data alone, especially in a young population, might underestimate disease risk. This study investigates accuracy of oral, systemic, and socioeconomic data on estimating periodontitis development...... in a population-based prospective cohort. METHODS: General health history and sociodemographic information were collected throughout the life-course of individuals. Oral examinations were performed at ages 24 and 31 years in the Pelotas 1982 birth cohort. Periodontitis at age 31 years according to six...... classifications was used as the gold standard to compute area under the receiver operating characteristic curve (AUC). Multivariable binomial regression models were used to evaluate the effects of oral health, general health, and socioeconomic characteristics on accuracy of periodontitis development prediction...

  10. Retrospectively ECG-gated multi-detector row CT of the chest: does ECG-gating improve three-dimensional visualization of the bronchial tree?

    International Nuclear Information System (INIS)

    Schertler, T.; Wildermuth, S.; Willmann, J.K.; Crook, D.W.; Marincek, B.; Boehm, T.

    2004-01-01

    Purpose: To determine the impact of retrospectively ECG-gated multi-detector row CT (MDCT) on three-dimensional (3D) visualization of the bronchial tree and virtual bronchoscopy (VB) as compared to non-ECG-gated data acquisition. Materials and Methods: Contrast-enhanced retrospectively ECG-gated and non-ECG-gated MDCT of the chest was performed in 25 consecutive patients referred for assessment of coronary artery bypass grafts and pathology of the ascending aorta. ECG-gated MDCT data were reconstructed in diastole using an absolute reverse delay of -400 msec in all patients. In 10 patients additional reconstructions at -200 msec, -300 msec, and -500 msec prior to the R-wave were performed. Shaded surface display (SSD) and virtual bronchoscopy (VB) for visualization of the bronchial segments was performed with ECG-gated and non-ECG-gated MDCT data. The visualization of the bronchial tree underwent blinded scoring. Effective radiation dose and signal-to-noise ratio (SNR) for both techniques were compared. Results: There was no significant difference in visualizing single bronchial segments using ECG-gated compared to non-ECG-gated MDCT data. However, the total sum of scores for all bronchial segments visualized with non-ECG-gated MDCT was significantly higher compared to ECG-gated MDCT (P [de

  11. Multidetector-row computed tomography for prosthetic heart valve dysfunction: is concomitant non-invasive coronary angiography possible before redo-surgery?

    Energy Technology Data Exchange (ETDEWEB)

    Tanis, Wilco [Haga Teaching Hospital, Department of Cardiology, The Hague (Netherlands); Haga Teaching Hospital, The Hague (Netherlands); Sucha, Dominika; Habets, Jesse [University Medical Center Utrecht, Department of Radiology, Utrecht (Netherlands); Laufer, Ward; Chamuleau, Steven [University Medical Center Utrecht, Department of Cardiology, Utrecht (Netherlands); Herwerden, Lex.A. van [University Medical Center Utrecht, Department of Cardiothoracic Surgery, Utrecht (Netherlands); Symersky, Petr [Vrije Universiteit, Department of Cardiothoracic Surgery, Amsterdam (Netherlands); Budde, Ricardo P.J. [Erasmus Medical Center, Department of Radiology, Rotterdam (Netherlands)

    2015-06-01

    Retrospective ECG-gated multidetector-row computed tomography (MDCT) is increasingly used for the assessment of prosthetic heart valve (PHV) dysfunction, but is also hampered by PHV-related artefacts/cardiac arrhythmias. Furthermore, it is performed without nitroglycerine or heart rate correction. The purpose was to determine whether MDCT performed before potential redo-PHV surgery is feasible for concomitant coronary artery stenosis assessment and can replace invasive coronary angiography (CAG). PHV patients with CAG and MDCT were identified. Based on medical history, two groups were created: (I) patients with no known coronary artery disease (CAD), (II) patients with known CAD. All images were scored for the presence of significant (>50 %) stenosis. CAG was the reference test. Fifty-one patients were included. In group I (n = 38), MDCT accurately ruled out significant stenosis in 19/38 (50 %) patients, but could not replace CAG in the remaining 19/38 (50 %) patients due to non-diagnostic image quality (n = 16) or significant stenosis (n = 3) detection. In group II (n = 13), MDCT correctly found no patients without significant stenosis, requiring CAG imaging in all. MDCT assessed patency in 16/19 (84 %) grafts and detected a hostile anatomy in two. MDCT performed for PHV dysfunction assessment can replace CAG (100 % accurate) in approximately half of patients without previously known CAD. (orig.)

  12. Noninvasive Coronary Angiography with 64-Channel Multidetector Computed Tomography in Patients with Acute Coronary Syndrome

    Energy Technology Data Exchange (ETDEWEB)

    Ulimoen, G. R.; Gjoennaess, E.; Atar, D.; Dahl, T.; Stranden, E.; Sandbaek, G. (Dept. of Radiology, Dept. of Vascular Diagnosis and Research, and Division of Cardiology, Aker Univ. Hospital, Oslo (Norway))

    2008-12-15

    Background: Advances in computer tomography (CT) imaging technology in recent years have facilitated the possibility of noninvasive coronary angiography. Purpose: To compare the diagnostic accuracy of 64-channel multidetector computed tomography (MDCT) with conventional invasive coronary angiography (ICA) for the detection of significant coronary stenosis in patients with acute coronary syndrome (ACS). Material and Methods: MDCT was performed in 60 patients classified with non-ST-elevation infarction (NSTEMI) or unstable angina and scheduled for ICA within 3 days. The diagnostic accuracy of MDCT was evaluated using quantitative coronary angiography (QCA) as the gold standard. Results: 48 out of 60 patients had interpretable scans by both MDCT and ICA. On a segment-based analysis, 488 out of 665 segments with a diameter of =1.5 mm, as defined by QCA, were interpretable by MDCT. Sensitivity was 78%, specificity 87%, positive predictive value 47%, and negative predictive value 97% in detecting and excluding significant coronary stenosis, as defined with MDCT. On a per patient-based analysis, sensitivity was 89%, specificity 50%, positive predictive value 84%, and negative predictive value 60%. Conclusion: Limited diagnostic accuracy restricts the usefulness of coronary MDCT in patient groups with a high pretest probability of disease, such as in acute coronary syndrome.

  13. Noninvasive Coronary Angiography with 64-Channel Multidetector Computed Tomography in Patients with Acute Coronary Syndrome

    International Nuclear Information System (INIS)

    Ulimoen, G. R.; Gjoennaess, E.; Atar, D.; Dahl, T.; Stranden, E.; Sandbaek, G.

    2008-01-01

    Background: Advances in computer tomography (CT) imaging technology in recent years have facilitated the possibility of noninvasive coronary angiography. Purpose: To compare the diagnostic accuracy of 64-channel multidetector computed tomography (MDCT) with conventional invasive coronary angiography (ICA) for the detection of significant coronary stenosis in patients with acute coronary syndrome (ACS). Material and Methods: MDCT was performed in 60 patients classified with non-ST-elevation infarction (NSTEMI) or unstable angina and scheduled for ICA within 3 days. The diagnostic accuracy of MDCT was evaluated using quantitative coronary angiography (QCA) as the gold standard. Results: 48 out of 60 patients had interpretable scans by both MDCT and ICA. On a segment-based analysis, 488 out of 665 segments with a diameter of =1.5 mm, as defined by QCA, were interpretable by MDCT. Sensitivity was 78%, specificity 87%, positive predictive value 47%, and negative predictive value 97% in detecting and excluding significant coronary stenosis, as defined with MDCT. On a per patient-based analysis, sensitivity was 89%, specificity 50%, positive predictive value 84%, and negative predictive value 60%. Conclusion: Limited diagnostic accuracy restricts the usefulness of coronary MDCT in patient groups with a high pretest probability of disease, such as in acute coronary syndrome

  14. Preoperative assessment of hilar cholangiocarcinoma using multidetector-row CT. Correlation with histopathological findings

    International Nuclear Information System (INIS)

    Watadani, Takeyuki; Akahane, Masaaki; Ohtomo, Kuni; Yoshikawa, Takeharu

    2008-01-01

    Our aim was to investigate the diagnostic reliability of multidetector-row computed tomography (MDCT) for preoperative assessment of local tumoral spread in hilar cholangiocarcinoma. Thirteen of 30 consecutive patients with hilar cholangiocarcinoma who underwent surgery, excluding 17 patients who underwent biliary drainage or preoperative portal embolization, were retrospectively evaluated. Using MDCT systems of 4 detector rows or 16 detector rows, plain and dynamic contrast-enhanced images of three phases were obtained. Extent of tumor spread and lymph node metastasis were assessed with MDCT and compared with histopathological findings. The Bismuth-Corlette classification of hilar cholangiocarcinoma with MDCT were type I, 1 patient; type IIIa, 3 patients; type IIIb, 4 patients; and type IV, 5 patients; those with histopathological findings were type I, 1 patient; type IIIa, 2 patients; type IIIb, 4 patients; and type IV, 6 patients. One patient diagnosed as type IIIa with MDCT was pathologically diagnosed as type IV. Accuracy of MDCT in tumoral spread was 92.3%, although that of lymph node metastasis was 54%. MDCT is likely to play an important role in evaluation of focal lesion spread especially in intrapancreatic tumor invasion, although a greater number of cohort cases are necessary to clearly define its role. (author)

  15. Multidetector-row computed tomography for prosthetic heart valve dysfunction: is concomitant non-invasive coronary angiography possible before redo-surgery?

    International Nuclear Information System (INIS)

    Tanis, Wilco; Sucha, Dominika; Habets, Jesse; Laufer, Ward; Chamuleau, Steven; Herwerden, Lex.A. van; Symersky, Petr; Budde, Ricardo P.J.

    2015-01-01

    Retrospective ECG-gated multidetector-row computed tomography (MDCT) is increasingly used for the assessment of prosthetic heart valve (PHV) dysfunction, but is also hampered by PHV-related artefacts/cardiac arrhythmias. Furthermore, it is performed without nitroglycerine or heart rate correction. The purpose was to determine whether MDCT performed before potential redo-PHV surgery is feasible for concomitant coronary artery stenosis assessment and can replace invasive coronary angiography (CAG). PHV patients with CAG and MDCT were identified. Based on medical history, two groups were created: (I) patients with no known coronary artery disease (CAD), (II) patients with known CAD. All images were scored for the presence of significant (>50 %) stenosis. CAG was the reference test. Fifty-one patients were included. In group I (n = 38), MDCT accurately ruled out significant stenosis in 19/38 (50 %) patients, but could not replace CAG in the remaining 19/38 (50 %) patients due to non-diagnostic image quality (n = 16) or significant stenosis (n = 3) detection. In group II (n = 13), MDCT correctly found no patients without significant stenosis, requiring CAG imaging in all. MDCT assessed patency in 16/19 (84 %) grafts and detected a hostile anatomy in two. MDCT performed for PHV dysfunction assessment can replace CAG (100 % accurate) in approximately half of patients without previously known CAD. (orig.)

  16. A comparative study of FDG PET/CT and enhanced multi-detector CT for detecting liver metastasis according to the size and location.

    Science.gov (United States)

    Park, Jung Mi; Kim, Il Young; Kim, Sang Won; Lee, Sang Mi; Kim, Hyun Gi; Kim, Shin Young; Shin, Hyung Chul

    2013-04-01

    The aim of this study was to compare the diagnosability between (18)F-fluorodeoxyglucose (FDG) PET/CT and enhanced multi-detector CT (MDCT) for the detection of liver metastasis (LM) according to the size and location in liver and to evaluate standard maximum standardized uptake values (SUVmax) of all liver metastatic lesions. One hundred two consecutive patients with malignancy who underwent both FDG PET/CT and MDCT for LM evaluation were retrospectively reviewed. Among them, 56 patients with LM were enrolled in this study. LM was confirmed by follow-up imaging studies after at least 6 months or by histopathology. FDG PET/CT and MDCT images were visually analyzed using three-point scale by the consensus of two radiologists and two nuclear medicine physicians. The size and location (central vs. sub-capsular) of the all liver lesions were evaluated using MDCT images. Furthermore, SUVmax of all liver lesions on FDG PET/CT images were calculated. A total of 146 liver lesions were detected by FDG PET/CT and MDCT and 142 of the lesions were diagnosed as LM. The detection rates of MDCT and FDG PET/CT for LM by visual analysis were 77 and 78%, respectively. There was no significant difference of detection rate according to the overall location and size of the lesions. However, FDG PET/CT was more sensitive than MDCT for detecting small and sub-capsular LM. The detection rate of FDG PET/CT for LM was 68% by the cutoff SUVmax of 2.7. Although the diagnosabilities of MDCT and FDG PET/CT for detecting LM were comparable, FDG PET/CT is superior to MDCT for detecting small LM located in the sub-capsular portion of liver.

  17. Assessment of left ventricular myocardial function using 16-slice multidetector-row computed tomography: comparison with magnetic resonance imaging and echocardiography

    International Nuclear Information System (INIS)

    Heuschmid, Martin; Rothfuss, Julia K.; Fenchel, Michael; Stauder, Norbert; Kuettner, Axel; Miller, Stephan; Claussen, Claus D.; Kopp, Andreas F.; Schroeder, Stephen; Burgstahler, Christof; Franow, Andreas; Kuzo, Ronald S.

    2006-01-01

    To assess functional parameters using multidetector-row computed tomography (MDCT) and echocardiography and to compare the results with magnetic resonance imaging (MRI). End-diastolic-volume (EDV), end-systolic-volume (ESV), stroke-volume (SV), ejection-fraction (EF), and myocardial mass (MM) were calculated based on CT data sets from 52 patients. Echocardiography was performed in 24 of the 52 patients. The results from MDCT and echocardiography were compared with MRI. A strong correlation between MDCT and MRI (r=0.66-0.90) was found for all parameters. Echocardiography revealed a low or moderate correlation (0.05-0.59). Compared to MRI the average differences with MDCT were for EDV 15.1 ml, ESV 10.6 ml, SV 4.5 ml, EF 1.8%, and MM 8.2 g, for EDV determined by echocardiography 36.2 ml, ESV 6.8 ml, and EF 13.9%. Bland-Altman analysis revealed acceptable limits of agreement between MRI and MDCT. MDCT enables reliable quantification of left ventricular function. Echocardiography was found to have only a moderate agreement of functional parameters with MRI. (orig.)

  18. Breast multidetector-row CT with histopathologic correlation

    International Nuclear Information System (INIS)

    Takeuchi, Makiko; Yamashita, Akiyoshi; Ohgi, Kazuyuki; Kobori, Kenichi; Furukawa, Takashi

    2004-01-01

    The purpose of this study was to evaluate the correlation between multidetector-row CT (MDCT) and histopathologic findings using the same MDCT image as the histopathologic cross-section. MDCT with contrast enhancement was performed in 10 patients with breast cancers (8 invasive ductal carcinomas, one invasive lobular carcinoma, and one non-invasive ductal carcinoma). We tried to reconstruct multiplanar reconstructions (MPR) in the same plane as the histopathologic cross-section, and we evaluated the histopathologic findings of the false-positive lesions. In all cases, we obtained the same MDCT image as the histopathologic cross-section. There were 10 main lesions and 18 other lesions. In the other lesions, we found no false-negative lesions and 11 false-positive lesions. False-positive lesions included periductal fibrosis, cystic change, duct papillomatosis, sclerosing adenosis, fibroadenoma, and others. Using MDCT of the breast, it is possible to obtain good correlation between CT images and histopathologic findings. MDCT is thought to be useful in the evaluation CT findings on the basis of histopathologic evidence. (author)

  19. Comparison of Diagnostic Accuracy of Radiation Dose-Equivalent Radiography, Multidetector Computed Tomography and Cone Beam Computed Tomography for Fractures of Adult Cadaveric Wrists.

    Science.gov (United States)

    Neubauer, Jakob; Benndorf, Matthias; Reidelbach, Carolin; Krauß, Tobias; Lampert, Florian; Zajonc, Horst; Kotter, Elmar; Langer, Mathias; Fiebich, Martin; Goerke, Sebastian M

    2016-01-01

    To compare the diagnostic accuracy of radiography, to radiography equivalent dose multidetector computed tomography (RED-MDCT) and to radiography equivalent dose cone beam computed tomography (RED-CBCT) for wrist fractures. As study subjects we obtained 10 cadaveric human hands from body donors. Distal radius, distal ulna and carpal bones (n = 100) were artificially fractured in random order in a controlled experimental setting. We performed radiation dose equivalent radiography (settings as in standard clinical care), RED-MDCT in a 320 row MDCT with single shot mode and RED-CBCT in a device dedicated to musculoskeletal imaging. Three raters independently evaluated the resulting images for fractures and the level of confidence for each finding. Gold standard was evaluated by consensus reading of a high-dose MDCT. Pooled sensitivity was higher in RED-MDCT with 0.89 and RED-MDCT with 0.81 compared to radiography with 0.54 (P = radiography (P radiography. Readers are more confident in their reporting with the cross sectional modalities. Dose equivalent cross sectional computed tomography of the wrist could replace plain radiography for fracture diagnosis in the long run.

  20. Cochlear Implant Electrode Localization Using an Ultra-High Resolution Scan Mode on Conventional 64-Slice and New Generation 192-Slice Multi-Detector Computed Tomography.

    Science.gov (United States)

    Carlson, Matthew L; Leng, Shuai; Diehn, Felix E; Witte, Robert J; Krecke, Karl N; Grimes, Josh; Koeller, Kelly K; Bruesewitz, Michael R; McCollough, Cynthia H; Lane, John I

    2017-08-01

    A new generation 192-slice multi-detector computed tomography (MDCT) clinical scanner provides enhanced image quality and superior electrode localization over conventional MDCT. Currently, accurate and reliable cochlear implant electrode localization using conventional MDCT scanners remains elusive. Eight fresh-frozen cadaveric temporal bones were implanted with full-length cochlear implant electrodes. Specimens were subsequently scanned with conventional 64-slice and new generation 192-slice MDCT scanners utilizing ultra-high resolution modes. Additionally, all specimens were scanned with micro-CT to provide a reference criterion for electrode position. Images were reconstructed according to routine temporal bone clinical protocols. Three neuroradiologists, blinded to scanner type, reviewed images independently to assess resolution of individual electrodes, scalar localization, and severity of image artifact. Serving as the reference standard, micro-CT identified scalar crossover in one specimen; imaging of all remaining cochleae demonstrated complete scala tympani insertions. The 192-slice MDCT scanner exhibited improved resolution of individual electrodes (p implant imaging compared with conventional MDCT. This technology provides important feedback regarding electrode position and course, which may help in future optimization of surgical technique and electrode design.

  1. Effect of radiation dose and iterative reconstruction on lung lesion conspicuity at MDCT: Does one size fit all?

    Energy Technology Data Exchange (ETDEWEB)

    Botelho, Marcos Paulo Ferreira; Agrawal, Rishi, E-mail: rishi.agrawal@northwestern.edu; Gonzalez-Guindalini, Fernanda Dias; Hart, Eric M.; Patel, Suresh K.; Töre, Hüseyin Gürkan; Yaghmai, Vahid

    2013-11-01

    Objective: To evaluate the effect of different acquisition parameters and reconstruction algorithms in lung lesions conspicuity in chest MDCT. Methods: An anthropomorphic chest phantom containing 6 models of lung disease (ground glass opacity, bronchial polyp, solid nodule, ground glass nodule, emphysema and tree-in-bud) was scanned using 80, 100 and 120 kVp, with fixed mAs ranging from 10 to 110. The scans were reconstructed using filtered back projection (FBP) and iterative reconstruction (IR) algorithms. Three blinded thoracic radiologists reviewed the images and scored lesions conspicuity and overall image quality. Image noise and radiation dose parameters were recorded. Results: All acquisitions with 120 kVp received a score of 3 (acceptable) or higher for overall image quality. There was no significant difference between IR and FBP within each setting for overall image quality (p > 0.05), even though image noise was significantly lower using IR (p < 0.0001). When comparing specific lower radiation acquisition parameters 100 kVp/10 mAs [Effective Dose (ED): 0.238 mSv] vs 120 kVp/10 mAs (ED: 0.406 mSv) vs 80 kVp/40 mAs (ED: 0.434 mSv), we observed significant difference in lesions conspicuity (p < 0.02), as well as significant difference in overall image quality, independent of the reconstruction algorithm (p < 0.02), with higher scores on the 120 kV/10 mAs setting. Tree-in-bud pattern, ground glass nodule and ground glass opacity required lower radiation doses to get a diagnostic score using IR when compared to FBP. Conclusion: Designing protocols for specific lung pathologies using lower dose acquisition parameters is feasible, and by applying iterative reconstruction, radiologists may have better diagnostic confidence to evaluate some lesions in very low dose settings, preserving acceptable image quality.

  2. Accurate estimation of global and regional cardiac function by retrospectively gated multidetector row computed tomography. Comparison with cine magnetic resonance imaging

    International Nuclear Information System (INIS)

    Belge, Benedicte; Pasquet, Agnes; Vanoverschelde, Jean-Louis J.; Coche, Emmanuel; Gerber, Bernhard L.

    2006-01-01

    Retrospective reconstruction of ECG-gated images at different parts of the cardiac cycle allows the assessment of cardiac function by multi-detector row CT (MDCT) at the time of non-invasive coronary imaging. We compared the accuracy of such measurements by MDCT to cine magnetic resonance (MR). Forty patients underwent the assessment of global and regional cardiac function by 16-slice MDCT and cine MR. Left ventricular (LV) end-diastolic and end-systolic volumes estimated by MDCT (134±51 and 67±56 ml) were similar to those by MR (137±57 and 70±60 ml, respectively; both P=NS) and strongly correlated (r=0.92 and r=0.95, respectively; both P<0.001). Consequently, LV ejection fractions by MDCT and MR were also similar (55±21 vs. 56±21%; P=NS) and highly correlated (r=0.95; P<0.001). Regional end-diastolic and end-systolic wall thicknesses by MDCT were highly correlated (r=0.84 and r=0.92, respectively; both P<0.001), but significantly lower than by MR (8.3±1.8 vs. 8.8±1.9 mm and 12.7±3.4 vs. 13.3±3.5 mm, respectively; both P<0.001). Values of regional wall thickening by MDCT and MR were similar (54±30 vs. 51±31%; P=NS) and also correlated well (r=0.91; P<0.001). Retrospectively gated MDCT can accurately estimate LV volumes, EF and regional LV wall thickening compared to cine MR. (orig.)

  3. Ultra-high resolution C-Arm CT arthrography of the wrist: Radiation dose and image quality compared to conventional multidetector computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Werncke, Thomas, E-mail: Werncke.Thomas@mh-hannover.de [Institute of Diagnostic and Interventional Radiology, Hannover Medical School, Carl-Neuberg-Str. 1, 30625 Hannover (Germany); Sonnow, Lena; Meyer, Bernhard C. [Institute of Diagnostic and Interventional Radiology, Hannover Medical School, Carl-Neuberg-Str. 1, 30625 Hannover (Germany); Lüpke, Matthias [University of Veterinary Medicine Hannover, Institute for General Radiology and Medical Physics, Bischofsholer Damm 15, 30173 Hannover (Germany); Hinrichs, Jan; Wacker, Frank K.; Falck, Christian von [Institute of Diagnostic and Interventional Radiology, Hannover Medical School, Carl-Neuberg-Str. 1, 30625 Hannover (Germany)

    2017-04-15

    Objective: Objective of this phantom and cadaveric study was to compare the effective radiation dose (ED) and image quality (IQ) between C-arm computed tomography (CACT) using an ultra-high resolution 1 × 1 binning with a standard 16-slice CT (MDCT) arthrography of the wrist. Methods: ED was determined with thermoluminescence dosimetry using an anthropomorphic phantom and different patient positions. Imaging was conducted in 10 human cadaveric wrists after tri-compartmental injection of diluted iodinated contrast material and a wire phantom. IQ of MDCT was compared with CACT reconstructed with a soft (CACT1) and sharp (CACT2) kernel. High and low contrast resolution was determined. Three radiologists assessed IQ of wrist structures and occurrence of image artifacts using a 5-point Likert scale. Results: ED of MDCT was comparable to standard CACT (4.3 μSv/3.7 μSv). High contrast resolution was best for CACT2, decreased to CACT1 and MDCT. Low contrast resolution increased between CACT2 and MDCT (P < 0.001). IQ was best for CACT2 (1.3 ± 0.5), decreased to CACT1 (1.9 ± 0.6) and MDCT (3.5 ± 0.6). Non-compromising artifacts were only reported for CACT. Conclusions: The results of this phantom and cadaveric study indicate that ultra-high resolution C-Arm CT arthrography of the wrist bears the potential to outperform MDCT arthrography in terms of image quality and workflow at the cost of mildly increasing image artifacts while radiation dose to the patient is comparably low for both, MDCT and C-Arm CT.

  4. Accuracy of multidetector CT in detecting anastomotic leaks following stapled left-sided colonic anastomosis

    International Nuclear Information System (INIS)

    Kaur, P.; Karandikar, S.S.; Roy-Choudhury, S.

    2014-01-01

    Aims: To assess accuracy of multidetector computed tomography (MDCT) and individual radiological signs in the diagnosis of anastomotic leaks. Materials and methods: Patients undergoing anterior resection with a stapled anastomosis over a 2 year period were identified. Electronic and clinical records of these patients were reviewed. Unenhanced and/or enhanced MDCT was performed with intravenous and/or per-rectal contrast medium and read by a radiologist blinded to the patients' clinical details to determine the sensitivity and specificity of specific findings at MDCT for identifying leaks. Results: Seventeen percent (30/170) of the anterior resections were suspected to have an anastomotic leak. Ninety-three percent (28/30) of patients underwent MDCT. Seven point six percent (11+2/170) had a confirmed leak. Two patients underwent surgery without MDCT. A leak was confirmed by MDCT in 91% (10/11) of patients. The sensitivity, specificity, and positive and negative predictive values of MDCT in diagnosing a leak was 0.91, 1, 1, and 0.95, respectively. The sensitivity of peri-anastomotic air, peri-anastomotic collection, extravasation of rectal contrast medium, and staple line integrity was 0.81, 0.63, 0.54, and 0.72, respectively. Use of rectal contrast medium (8/11 cases) increased the subjective ease of diagnosis and was the only sign in one patient. Conclusions: Presence of peri-anastomotic air is a reliable marker of anastomotic leaks at MDCT. Leakage of rectal contrast medium is highly accurate and increases confidence of diagnosis. The appearance of the staple line itself is not accurate in assessing anastomotic integrity

  5. Comparison of the radiation dose from cone beam computed tomography and multidetector computed tomography in examinations of the hand; Vergleich der Strahlendosis von Cone-Beam Computertomografie und Multidetektor Computertomografie in Untersuchungen der Hand

    Energy Technology Data Exchange (ETDEWEB)

    Neubauer, J.; Neubauer, C.; Gerstmair, A.; Krauss, T.; Kotter, E.; Langer, M. [University Medical Center Freiburg (Germany). Dept. of Radiology; Reising, K. [University Medical Center Freiburg (Germany). Dept. of Orthopedics and Trauma Surgery; Zajonc, H. [University Medical Center Freiburg (Germany). Dept. of Plastic and Hand Surgery; Fiebich, M.; Voigt, J. [University of Applied Sciences, Giessen (Germany). Inst. of Medical Physics and Radiation Protection

    2016-05-15

    Comparison of radiation dose of cone beam computed tomography (CBCT) and multidetector computed tomography (MDCT) in examinations of the hand. Dose calculations were carried out by means of Monte Carlo simulations in MDCT and CBCT. A corpse hand was examined in a 320-row MDCT scanner and a dedicated extremities CBCT scanner with standard protocols and multiple low-dose protocols. The image quality of the examinations was evaluated by 5 investigators using a Likert scale from 1 (very good) to 5 (very poor) regarding depiction of cortical bone, cancellous bone, joint surfaces, soft tissues and artifacts. For a sum of ratings of all structures < 50 a good overall image quality was expected. The studies with at least good overall image quality were compared with respect to the dose. The dose of the standard examination was 13.21 (12.96 to 13.46 CI) mGy in MDCT and 7.15 (6.99 to 7.30 CI) mGy in CBCT. The lowest dose in a study with good overall image quality was 4.54 (4.43 to 4.64 CI) mGy in MDCT and 5.72 (5.59 to 5.85 CI) mGy in CBCT. Although the dose of the standard protocols in the CBCT is lower than in the MDCT, the MDCT can realize a good overall image quality at a lower dose than the CBCT. Dose optimization of CT examination protocols for the hand is useful in both modalities, the MDCT has an even greater potential for optimization.

  6. The value of multidetector-row computed tomography for localization of obscure acute gastrointestinal bleeding

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Wei-Chou [Department of Radiology, Tri-Service General Hospital, National Defense Medical Center, Taiwan (China); Tsai, Shih-Hung [Department of Emergency Medicine, Tri-Service General Hospital, National Defense Medical Center, Taiwan (China); Chang, Wei-Kuo [Division of Gasteroenterology, Department of Internal Medicine, Tri-Service General Hospital, National Defense Medical Center, Taiwan (China); Liu, Chang-Hsien [Department of Radiology, Tri-Service General Hospital, National Defense Medical Center, Taiwan (China); Tung, Ho-Jui [Department of Healthcare Administration, Asia University, Taichung, Taiwan (China); Hsieh, Chung-Bao [Department of Surgery, Tri-Service General Hospital, National Defense Medical Center, Taiwan (China); Huang, Guo-Shu; Hsu, Hsian-He [Department of Radiology, Tri-Service General Hospital, National Defense Medical Center, Taiwan (China); Yu, Chih-Yung, E-mail: chougo2002@yahoo.com.tw [Department of Radiology, Tri-Service General Hospital, National Defense Medical Center, Taiwan (China)

    2011-11-15

    Purpose: There are no simple guidelines on when to perform multidetector-row computed tomography (MDCT) for diagnosis of obscure acute gastrointestinal bleeding (AGIB). We used a risk scoring system to evaluate the diagnostic power of MDCT for patients with obscure AGIB. Materials and methods: Ninety-two patients with obscure AGIB who were referred for an MDCT scan after unsuccessful endoscopic treatment at presentation were studied. We recorded clinical data and calculated Blatchford score for each patient. Patients who required transfusion more than 500 mL of blood to maintain the vital signs were classified as high-risk patients. Two radiologists independently reviewed and categorized MDCT signs of obscure AGIB. Discordant findings were resolved by consensus. One-way ANOVA was used to compare clinical data between two groups; kappa statistics were used to estimate agreement on MDCT findings between radiologists. Results: Of the 92 patients, 62 (67.4%) were classified as high-risk patients. Blatchford scores of high-risk patients were significantly greater than those of low-risk patients. Sensitivity for MDCT diagnosing obscure AGIB was 81% in high-risk patients, as compared with 50% in the low-risk. When used in conjunction with selection of the cut-off value of 13 in Blatchford scoring system, the sensitivity and specificity of MDCT were 70.9% and 73.7%, respectively. Contrast extravasation was the most specific sign of AGIB (k = .87), recognition of which would have improved diagnostic accuracy. Conclusions: With the aid of Blatchford scoring system for evaluating the disease severity, MDCT can localize the bleeders of obscure AGIB more efficiently.

  7. The value of multidetector-row computed tomography for localization of obscure acute gastrointestinal bleeding

    International Nuclear Information System (INIS)

    Chang, Wei-Chou; Tsai, Shih-Hung; Chang, Wei-Kuo; Liu, Chang-Hsien; Tung, Ho-Jui; Hsieh, Chung-Bao; Huang, Guo-Shu; Hsu, Hsian-He; Yu, Chih-Yung

    2011-01-01

    Purpose: There are no simple guidelines on when to perform multidetector-row computed tomography (MDCT) for diagnosis of obscure acute gastrointestinal bleeding (AGIB). We used a risk scoring system to evaluate the diagnostic power of MDCT for patients with obscure AGIB. Materials and methods: Ninety-two patients with obscure AGIB who were referred for an MDCT scan after unsuccessful endoscopic treatment at presentation were studied. We recorded clinical data and calculated Blatchford score for each patient. Patients who required transfusion more than 500 mL of blood to maintain the vital signs were classified as high-risk patients. Two radiologists independently reviewed and categorized MDCT signs of obscure AGIB. Discordant findings were resolved by consensus. One-way ANOVA was used to compare clinical data between two groups; kappa statistics were used to estimate agreement on MDCT findings between radiologists. Results: Of the 92 patients, 62 (67.4%) were classified as high-risk patients. Blatchford scores of high-risk patients were significantly greater than those of low-risk patients. Sensitivity for MDCT diagnosing obscure AGIB was 81% in high-risk patients, as compared with 50% in the low-risk. When used in conjunction with selection of the cut-off value of 13 in Blatchford scoring system, the sensitivity and specificity of MDCT were 70.9% and 73.7%, respectively. Contrast extravasation was the most specific sign of AGIB (k = .87), recognition of which would have improved diagnostic accuracy. Conclusions: With the aid of Blatchford scoring system for evaluating the disease severity, MDCT can localize the bleeders of obscure AGIB more efficiently.

  8. Reduction of the nitro group during sample preparation may cause underestimation of the nitration level in 3-nitrotyrosine immunoblotting

    DEFF Research Database (Denmark)

    Söderling, Ann-Sofi; Hultman, Lena; Delbro, Dick

    2007-01-01

    We noted differences in the antibody response to 3-nitrotyrosine (NO(2)Tyr) in fixed and non-fixed tissues, and studied therefore potential problems associated with non-fixed tissues in Western blot analyses. Three different monoclonal anti-nitrotyrosine antibodies in Western blot analysis of inf...... is not detected by anti-NO(2)Tyr antibodies. Western blot analysis may therefore underestimate the level of tissue nitration, and factors causing a reduction of NO(2)Tyr during sample preparation might conceal the actual nitration of proteins....

  9. The 'simple' general dental anaesthetic

    African Journals Online (AJOL)

    Dental anaesthesia should not be underestimated. Eddie Oosthuizen .... dental surgeon has limited training in airway management. ... primary teeth to hours for extensive dental conservation .... options after the extraction of permanent teeth ...

  10. Systematic underestimation of the age of samples with saturating exponential behaviour and inhomogeneous dose distribution

    International Nuclear Information System (INIS)

    Brennan, B.J.

    2000-01-01

    In luminescence and ESR studies, a systematic underestimate of the (average) equivalent dose, and thus also the age, of a sample can occur when there is significant variation of the natural dose within the sample and some regions approach saturation. This is demonstrated explicitly for a material that exhibits a single-saturating-exponential growth of signal with dose. The result is valid for any geometry (e.g. a plain layer, spherical grain, etc.) and some illustrative cases are modelled, with the age bias exceeding 10% in extreme cases. If the dose distribution within the sample can be modelled accurately, it is possible to correct for the bias in the estimates of equivalent dose estimate and age. While quantifying the effect would be more difficult, similar systematic biases in dose and age estimates are likely in other situations more complex than the one modelled

  11. Multidetector-row computed tomography management of acute pulmonary embolism

    International Nuclear Information System (INIS)

    Yasui, Takahiro; Tanabe, Nobuhiro; Terada, Jiro

    2007-01-01

    The purpose of this study was to evaluate the usefulness and safety of multidetector-row computed tomography (MDCT) pulmonary angiography and indirect venography management of acute pulmonary embolism (PE), including indication for inferior vena cava (IVC) filter. Seventy-one consecutive patients who were clinically suspected of PE and underwent 16-slice MDCT pulmonary angiography and indirect venography were enrolled. Management included indication of IVC filter for patients with extensive deep venous thrombosis (DVT) in submassive or massive PE. A right ventricular to left ventricular short-axis diameter by MDCT >1.0 was judged as submassive PE. All patients were followed for 1 year. MDCT identified 50 patients with venous thromboembolism and 47 patients had acute PE: 4 were judged as massive, 14 as submassive, and 29 as non-massive by MDCT; 3 patients had DVT alone and 7 patients had caval or iliac DVT. Only 1 patient with massive PE and DVT near the right atrium died of recurrence. No other patients died of PE. Management based on MDCT pulmonary angiography combined with indirect venography is considered to be safe and reliable in patients with suspected acute PE. (author)

  12. Measurements of pericardial adipose tissue using contrast enhanced cardiac multidetector computed tomography—comparison with cardiac magnetic resonance imaging

    DEFF Research Database (Denmark)

    Elming, Marie Bayer; Lønborg, Jacob; Rasmussen, Thomas

    2013-01-01

    and CMRI scans were performed. The optimal fit for measuring PAT using contrast MDCT was developed and validated by the corresponding measures on CMRI. The median for PAT volume in patients was 175 ml (SD 68) and 153 ml (SD 60) measured by MDCT and CMRI respectively. Four different attenuation values were...... tested, and the smallest difference in PAT was noted when -30 to -190 HU were used in MDCT measures. The median difference between MDCT and CMRI for the assessment of PAT was 9 ml (SD 50) suggesting a reasonable robust method for the assessment of PAT in a large-scale study. Pericardial adipose tissue...

  13. Pneumomediastinum on Multidetector CT: The Radiologic Signs and Underlying Disorders

    Energy Technology Data Exchange (ETDEWEB)

    Oh, Soo Jin; Kim, Young Tong [Soonchunhyang University Chunan Hospital, Cheonan (Korea, Republic of)

    2011-02-15

    We can see the typical signs of pneumomediastinum on chest radiography and we can also see them on the multiplanar reformatted (MPR) image of multidetector CT (MDCT). MDCT can help to understand the anatomical feature of these signs and differentiate pneumomediastinum from pneumothorax, pneumopericardium and the Mach band effect. MDCT shows the peribronchovascular air, which reveals the Macklin effect, and it can also evaluate the underlying disorders that cause pneumomediastinum. The purpose of this pictorial essay is to inform physicians about the mechanism and anatomical features of pneumomediastinum, and to help them understand the imaging findings and underlying disorders of pneumomediastinum as seen on MDCT

  14. Climatology of the HOPE-G global ocean general circulation model - Sea ice general circulation model

    Energy Technology Data Exchange (ETDEWEB)

    Legutke, S. [Deutsches Klimarechenzentrum (DKRZ), Hamburg (Germany); Maier-Reimer, E. [Max-Planck-Institut fuer Meteorologie, Hamburg (Germany)

    1999-12-01

    The HOPE-G global ocean general circulation model (OGCM) climatology, obtained in a long-term forced integration is described. HOPE-G is a primitive-equation z-level ocean model which contains a dynamic-thermodynamic sea-ice model. It is formulated on a 2.8 grid with increased resolution in low latitudes in order to better resolve equatorial dynamics. The vertical resolution is 20 layers. The purpose of the integration was both to investigate the models ability to reproduce the observed general circulation of the world ocean and to obtain an initial state for coupled atmosphere - ocean - sea-ice climate simulations. The model was driven with daily mean data of a 15-year integration of the atmosphere general circulation model ECHAM4, the atmospheric component in later coupled runs. Thereby, a maximum of the flux variability that is expected to appear in coupled simulations is included already in the ocean spin-up experiment described here. The model was run for more than 2000 years until a quasi-steady state was achieved. It reproduces the major current systems and the main features of the so-called conveyor belt circulation. The observed distribution of water masses is reproduced reasonably well, although with a saline bias in the intermediate water masses and a warm bias in the deep and bottom water of the Atlantic and Indian Oceans. The model underestimates the meridional transport of heat in the Atlantic Ocean. The simulated heat transport in the other basins, though, is in good agreement with observations. (orig.)

  15. An underestimated role of precipitation frequency in regulating summer soil moisture

    International Nuclear Information System (INIS)

    Wu Chaoyang; Chen, Jing M; Pumpanen, Jukka; Cescatti, Alessandro; Marcolla, Barbara; Blanken, Peter D; Ardö, Jonas; Tang, Yanhong; Magliulo, Vincenzo; Georgiadis, Teodoro; Soegaard, Henrik; Cook, David R; Harding, Richard J

    2012-01-01

    Soil moisture induced droughts are expected to become more frequent under future global climate change. Precipitation has been previously assumed to be mainly responsible for variability in summer soil moisture. However, little is known about the impacts of precipitation frequency on summer soil moisture, either interannually or spatially. To better understand the temporal and spatial drivers of summer drought, 415 site yr measurements observed at 75 flux sites world wide were used to analyze the temporal and spatial relationships between summer soil water content (SWC) and the precipitation frequencies at various temporal scales, i.e., from half-hourly, 3, 6, 12 and 24 h measurements. Summer precipitation was found to be an indicator of interannual SWC variability with r of 0.49 (p < 0.001) for the overall dataset. However, interannual variability in summer SWC was also significantly correlated with the five precipitation frequencies and the sub-daily precipitation frequencies seemed to explain the interannual SWC variability better than the total of precipitation. Spatially, all these precipitation frequencies were better indicators of summer SWC than precipitation totals, but these better performances were only observed in non-forest ecosystems. Our results demonstrate that precipitation frequency may play an important role in regulating both interannual and spatial variations of summer SWC, which has probably been overlooked or underestimated. However, the spatial interpretation should carefully consider other factors, such as the plant functional types and soil characteristics of diverse ecoregions. (letter)

  16. Vast underestimation of Madagascar's biodiversity evidenced by an integrative amphibian inventory.

    Science.gov (United States)

    Vieites, David R; Wollenberg, Katharina C; Andreone, Franco; Köhler, Jörn; Glaw, Frank; Vences, Miguel

    2009-05-19

    Amphibians are in decline worldwide. However, their patterns of diversity, especially in the tropics, are not well understood, mainly because of incomplete information on taxonomy and distribution. We assess morphological, bioacoustic, and genetic variation of Madagascar's amphibians, one of the first near-complete taxon samplings from a biodiversity hotspot. Based on DNA sequences of 2,850 specimens sampled from over 170 localities, our analyses reveal an extreme proportion of amphibian diversity, projecting an almost 2-fold increase in species numbers from the currently described 244 species to a minimum of 373 and up to 465. This diversity is widespread geographically and across most major phylogenetic lineages except in a few previously well-studied genera, and is not restricted to morphologically cryptic clades. We classify the genealogical lineages in confirmed and unconfirmed candidate species or deeply divergent conspecific lineages based on concordance of genetic divergences with other characters. This integrative approach may be widely applicable to improve estimates of organismal diversity. Our results suggest that in Madagascar the spatial pattern of amphibian richness and endemism must be revisited, and current habitat destruction may be affecting more species than previously thought, in amphibians as well as in other animal groups. This case study suggests that worldwide tropical amphibian diversity is probably underestimated at an unprecedented level and stresses the need for integrated taxonomic surveys as a basis for prioritizing conservation efforts within biodiversity hotspots.

  17. Echocardiography underestimates stroke volume and aortic valve area: implications for patients with small-area low-gradient aortic stenosis.

    Science.gov (United States)

    Chin, Calvin W L; Khaw, Hwan J; Luo, Elton; Tan, Shuwei; White, Audrey C; Newby, David E; Dweck, Marc R

    2014-09-01

    Discordance between small aortic valve area (AVA; area (LVOTarea) and stroke volume alongside inconsistencies in recommended thresholds. One hundred thirty-three patients with mild to severe AS and 33 control individuals underwent comprehensive echocardiography and cardiovascular magnetic resonance imaging (MRI). Stroke volume and LVOTarea were calculated using echocardiography and MRI, and the effects on AVA estimation were assessed. The relationship between AVA and MPG measurements was then modelled with nonlinear regression and consistent thresholds for these parameters calculated. Finally the effect of these modified AVA measurements and novel thresholds on the number of patients with small-area low-gradient AS was investigated. Compared with MRI, echocardiography underestimated LVOTarea (n = 40; -0.7 cm(2); 95% confidence interval [CI], -2.6 to 1.3), stroke volumes (-6.5 mL/m(2); 95% CI, -28.9 to 16.0) and consequently, AVA (-0.23 cm(2); 95% CI, -1.01 to 0.59). Moreover, an AVA of 1.0 cm(2) corresponded to MPG of 24 mm Hg based on echocardiographic measurements and 37 mm Hg after correction with MRI-derived stroke volumes. Based on conventional measures, 56 patients had discordant small-area low-gradient AS. Using MRI-derived stroke volumes and the revised thresholds, a 48% reduction in discordance was observed (n = 29). Echocardiography underestimated LVOTarea, stroke volume, and therefore AVA, compared with MRI. The thresholds based on current guidelines were also inconsistent. In combination, these factors explain > 40% of patients with discordant small-area low-gradient AS. Copyright © 2014 Canadian Cardiovascular Society. Published by Elsevier Inc. All rights reserved.

  18. Comparison of the Multidetector-row Computed Tomographic Angiography Axial and Coronal Planes' Usefulness for Detecting Thoracodorsal Artery Perforators

    Science.gov (United States)

    Kim, Jong Gyu

    2012-01-01

    Background During the planning of a thoracodorsal artery perforator (TDAP) free flap, preoperative multidetector-row computed tomographic (MDCT) angiography is valuable for predicting the locations of perforators. However, CT-based perforator mapping of the thoracodorsal artery is not easy because of its small diameter. Thus, we evaluated 1-mm-thick MDCT images in multiple planes to search for reliable perforators accurately. Methods Between July 2010 and October 2011, 19 consecutive patients (13 males, 6 females) who underwent MDCT prior to TDAP free flap operations were enrolled in this study. Patients ranged in age from 10 to 75 years (mean, 39.3 years). MDCT images were acquired at a thickness of 1 mm in the axial, coronal, and sagittal planes. Results The thoracodorsal artery perforators were detected in all 19 cases. The reliable perforators originating from the descending branch were found in 14 cases, of which 6 had transverse branches. The former were well identified in the coronal view, and the latter in the axial view. The location of the most reliable perforators on MDCT images corresponded well with the surgical findings. Conclusions Though MDCT has been widely used in performing the abdominal perforator free flap for detecting reliable perforating vessels, it is not popular in the TDAP free flap. The results of this study suggest that multiple planes of MDCT may increase the probability of detecting the most reliable perforators, along with decreasing the probability of missing available vessels. PMID:22872839

  19. The role of multidetector computed tomography in evaluation of small bowel obstructions

    Directory of Open Access Journals (Sweden)

    Mehmet Fatih İnci

    2013-03-01

    Full Text Available Objective: The purpose of the study was to evaluate therole and additional diagnostic contribution of multi-detectorcomputed tomography (MDCT in patients with acuteabdominal pain caused by small bowel obstruction.Materials and methods: A total of 48 patients who admittedto our hospital with acute abdominal pain and underwentMDCT on suspicion of intestinal obstruction and hadabdominal surgery between January 2012 and October2012 were included to our study. MDCT images were interpretedby two experienced radiologist retrospectively.All clinical data and surgery notes also were evaluated.Patients had surgery due to penetrating or blunt abdominalinjury were excluded.Results: Of these 48 patients, 26 (54.1% were male and22 (45.9% were female. Patients’ ages ranged 25 to 71and mean age was 52±5.4 years. The causes of intestinalobstruction of patients were adhesions for 12 (46.1% patients,tumors for 7 (26.9% patients, external hernias for5 (19.2% patients, internal hernia for 1 (3.9% patient andintussusception for 1 (3.9% patient. A total concordancebetween the MDCT findings and definitive diagnosis wasfound in 26 of 23 cases and the sensitivity and specifityof MDCT in the diagnosis of small bowel obstruction werefound to be 88.5% and 90%, respectively.Conclusion: MDCT is a fast, effective and reliable imagingmethod for preoperative diagnosing small bowel obstructioncauses acute abdominal pain with the advantagesof MDCT such as multi-planar and three-dimensionalreformatted imaging.Key words: Acute abdominal pain, multi-detector computed tomography, small bowel obstruction

  20. Using multidetector-row CT in neonates with complex congenital heart disease to replace diagnostic cardiac catheterization for anatomical investigation: initial experiences in technical and clinical feasibility

    International Nuclear Information System (INIS)

    Lee, Tain; Tsai, I.C.; Chen, Min-Chi; Fu, Yun-Ching; Jan, Sheng-Lin; Wang, Chung-Chi; Chang, Yen

    2006-01-01

    Echocardiography is the first-line modality for the investigation of neonatal congenital heart disease. Diagnostic cardiac catheterization, which has a small but recognized risk, is usually performed if echocardiography fails to provide a confident evaluation of the lesions. To verify the technical and clinical feasibilities of replacing diagnostic cardiac catheterization with multidetector-row CT (MDCT) in neonatal complex congenital heart disease. Over a 1-year period we prospectively enrolled all neonates with complex congenital heart disease referred for diagnostic cardiac catheterization after initial assessment by echocardiography. MDCT was performed using a 40-detector-row CT scanner with dual syringe injection. A multidisciplinary congenital heart disease team evaluated the MDCT images and decided if further diagnostic cardiac catheterization was necessary. The accuracy of MDCT in detecting separate cardiovascular anomalies and bolus geometry of contrast enhancement were calculated. A total of 14 neonates were included in the study. No further diagnostic cardiac catheterization was needed in any neonate. The accuracy of MDCT in diagnosing separate cardiovascular anomalies was 98% (53/54) with only one atrial septal defect missed in a patient with coarctation syndrome. The average cardiovascular enhancement in evaluated chambers was 471 HU. No obvious beam-hardening artefact was observed. The technical and clinical feasibility of MDCT in complex congenital heart disease in neonates is confirmed. After initial assessment with echocardiography, MDCT could probably replace diagnostic cardiac catheterization for further anatomical clarification in neonates. (orig.)