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Sample records for ct screening studies

  1. Genome-wide association study of coronary and aortic calcification in lung cancer screening CT

    Science.gov (United States)

    de Vos, Bob D.; van Setten, Jessica; de Jong, Pim A.; Mali, Willem P.; Oudkerk, Matthijs; Viergever, Max A.; Išgum, Ivana

    2016-03-01

    Arterial calcification has been related to cardiovascular disease (CVD) and osteoporosis. However, little is known about the role of genetics and exact pathways leading to arterial calcification and its relation to bone density changes indicating osteoporosis. In this study, we conducted a genome-wide association study of arterial calcification burden, followed by a look-up of known single nucleotide polymorphisms (SNPs) for coronary artery disease (CAD) and myocardial infarction (MI), and bone mineral density (BMD) to test for a shared genetic basis between the traits. The study included a subcohort of the Dutch-Belgian lung cancer screening trial comprised of 2,561 participants. Participants underwent baseline CT screening in one of two hospitals participating in the trial. Low-dose chest CT images were acquired without contrast enhancement and without ECG-synchronization. In these images coronary and aortic calcifications were identified automatically. Subsequently, the detected calcifications were quantified using coronary artery calcium Agatston and volume scores. Genotype data was available for these participants. A genome-wide association study was conducted on 10,220,814 SNPs using a linear regression model. To reduce multiple testing burden, known CAD/MI and BMD SNPs were specifically tested (45 SNPs from the CARDIoGRAMplusC4D consortium and 60 SNPS from the GEFOS consortium). No novel significant SNPs were found. Significant enrichment for CAD/MI SNPs was observed in testing Agatston and coronary artery calcium volume scores. Moreover, a significant enrichment of BMD SNPs was shown in aortic calcium volume scores. This may indicate genetic relation of BMD SNPs and arterial calcification burden.

  2. Screening of illegal intracorporeal containers ("body packing"): is abdominal radiography sufficiently accurate? A comparative study with low-dose CT.

    Science.gov (United States)

    Poletti, Pierre-Alexandre; Canel, Laurent; Becker, Christoph D; Wolff, Hans; Elger, Bernice; Lock, Eric; Sarasin, François; Bonfanti, Monica S; Dupuis-Lozeron, Elise; Perneger, Thomas; Platon, Alexandra

    2012-12-01

    To evaluate the diagnostic performance of abdominal radiography in the detection of illegal intracorporeal containers (hereafter, packets), with low-dose computed tomography (CT) as the reference standard. This study was approved by the institutional ethical review board, with written informed consent. From July 2007 to July 2010, 330 people (296 men, 34 women; mean age, 32 years [range, 18-55 years]) suspected of having ingested drug packets underwent supine abdominal radiography and low-dose CT. The presence or absence of packets at abdominal radiography was reported, with low-dose CT as the reference standard. The density and number of packets (≤ 12 or >12) at low-dose CT were recorded and analyzed to determine whether those variables influence interpretation of results at abdominal radiography. Packets were detected at low-dose CT in 53 (16%) suspects. Sensitivity of abdominal radiography for depiction of packets was 0.77 (41 of 53), and specificity was 0.96 (267 of 277). The packets appeared isoattenuated to the bowel contents at low-dose CT in 16 (30%) of the 53 suspects with positive results. Nineteen (36%) of the 53 suspects with positive low-dose CT results had fewer than 12 packets. Packets that were isoattenuated at low-dose CT and a low number of packets (≤12) were both significantly associated with false-negative results at abdominal radiography (P = .004 and P = .016, respectively). Abdominal radiography is mainly limited by low sensitivity when compared with low-dose CT in the screening of people suspected of carrying drug packets. Low-dose CT is an effective imaging alternative to abdominal radiography. © RSNA, 2012.

  3. Low-dose lung cancer screening with photon-counting CT: a feasibility study

    Science.gov (United States)

    Symons, Rolf; Cork, Tyler E.; Sahbaee, Pooyan; Fuld, Matthew K.; Kappler, Steffen; Folio, Les R.; Bluemke, David A.; Pourmorteza, Amir

    2017-01-01

    To evaluate the feasibility of using a whole-body photon-counting detector (PCD) CT scanner for low-dose lung cancer screening compared to a conventional energy integrating detector (EID) system. Radiation dose-matched EID and PCD scans of the COPDGene 2 phantom were acquired at different radiation dose levels (CTDIvol: 3.0, 1.5, and 0.75 mGy) and different tube voltages (120, 100, and 80 kVp). EID and PCD images were compared for quantitative Hounsfield unit (HU) accuracy, noise levels, and contrast-to-noise ratios (CNR) for detection of ground-glass nodules (GGN) and emphysema. The PCD HU accuracy was better than EID for water at all scan parameters. PCD HU stability for lung, GGN and emphysema regions were superior to EID and PCD attenuation values were more reproducible than EID for all scan parameters (all P  lung, GGN and emphysema ROIs changed significantly for EID with decreasing dose (all P  lung, ground-glass, and emphysema-equivalent foams at lower radiation dose settings with better reproducibility than EID. Additionally, PCD showed up to 10% less noise, and 11% higher CNR at 0.75 mGy for both 100 and 80 kVp. PCD technology may help reduce radiation exposure in lung cancer screening while maintaining diagnostic quality.

  4. Radiation exposure in whole body CT screening.

    Science.gov (United States)

    Suresh, Pamidighantam; Ratnam, S V; Rao, K V J

    2011-04-01

    Using a technology that "takes a look" at people's insides and promises early warnings of cancer, cardiac disease, and other abnormalities, clinics and medical imaging facilities nationwide are touting a new service for health conscious people: "Whole body CT screening" this typically involves scanning the body from the chin to below the hips with a form of x-ray imaging that produces cross-sectional images. In USA direct-to-consumer marketing of whole body CT is occurring today in many metropolitan areas. Free standing CT screening centres are being sited in shopping malls and other high density public areas, and these centres are being advertised in the electronic and print media. In this context the present article discussed the pros and cons of having such centres in India with the advent of multislice CT leading to fast scan times.

  5. Screening of mixed surfactant systems: Phase behavior studies and CT imaging of surfactant-enhanced oil recovery experiments

    Energy Technology Data Exchange (ETDEWEB)

    Llave, F.M.; Gall, B.L.; Lorenz, P.B.; Cook, I.M.; Scott, L.J.

    1993-11-01

    A systematic chemical screening study was conducted on selected anionic-nonionic and nonionic-nonionic systems. The objective of the study was to evaluate and determine combinations of these surfactants that would exhibit favorable phase behavior and solubilization capacity. The effects of different parameters including (a) salinity, (b) temperature, (c) alkane carbon number, (c) hydrophilic/lipophilic balance (HLB) of nonionic component, and (d) type of surfactant on the behavior of the overall chemical system were evaluated. The current work was conducted using a series of ethoxylated nonionic surfactants in combinations of several anionic systems with various hydrocarbons. Efforts to correlate the behavior of these mixed systems led to the development of several models for the chemical systems tested. The models were used to compare the different systems and provided some guidelines for formulating them to account for variations in salinity, oil hydrocarbon number, and temperature. The models were also evaluated to determine conformance with the results from experimental measurements. The models provided good agreement with experimental results. X-ray computed tomography (CT) was used to study fluid distributions during chemical enhanced oil recovery experiments. CT-monitored corefloods were conducted to examine the effect of changing surfactant slug size injection on oil bank formation and propagation. Reducing surfactant slug size resulted in lower total oil production. Oil recovery results, however, did not correlate with slug size for the low-concentration, alkaline, mixed surfactant system used in these tests. The CT measurements showed that polymer mobility control and core features also affected the overall oil recovery results.

  6. Pulmonary function and CT biomarkers as risk factors for cardiovascular events in male lung cancer screening participants: the NELSON study

    Energy Technology Data Exchange (ETDEWEB)

    Takx, Richard A.P.; Hoesein, Firdaus A.A.M.; Mali, Willem P.T.M.; Leiner, Tim; Jong, Pim A. de [University Medical Center Utrecht, Department of Radiology, Utrecht (Netherlands); Vliegenthart, Rozemarijn [University of Groningen, University Medical Center Groningen, Center for Medical Imaging - North East Netherlands, Groningen (Netherlands); University of Groningen, University Medical Center Groningen, Department of Radiology, Groningen (Netherlands); Isgum, Ivana [University Medical Center Utrecht, Image Sciences Institute, Utrecht (Netherlands); Koning, Harry J. de; Aalst, Carlijn M. van der [Erasmus Medical Center Rotterdam, Department of Public Health, Rotterdam (Netherlands); Zanen, Pieter; Lammers, Jan-Willem J. [University Medical Center Utrecht, Department of Pulmonology, Utrecht (Netherlands); Groen, Harry J.M. [University Medical Center Groningen, Department of Pulmonology, Groningen (Netherlands); Rikxoort, Eva M. van; Ginneken, Bram van [Radboud University Nijmegen Medical Centre, Department of Radiology, Nijmegen (Netherlands); Institute for Medical Image Computing, Fraunhofer MEVIS, Bremen (Germany); Schmidt, Michael [Institute for Medical Image Computing, Fraunhofer MEVIS, Bremen (Germany); Oudkerk, Matthijs [University of Groningen, University Medical Center Groningen, Center for Medical Imaging - North East Netherlands, Groningen (Netherlands)

    2015-01-15

    The objective of this study was to investigate the association of spirometry and pulmonary CT biomarkers with cardiovascular events. In this lung cancer screening trial 3,080 male participants without a prior cardiovascular event were analysed. Fatal and non-fatal cardiovascular events were included. Spirometry included forced expiratory volume measured in units of one-second percent predicted (FEV{sub 1}%predicted) and FEV{sub 1} divided by forced vital capacity (FVC; FEV{sub 1}/FVC). CT examinations were quantified for coronary artery calcium volume, pulmonary emphysema (perc15) and bronchial wall thickness (pi10). Data were analysed via a Cox proportional hazard analysis, net reclassification improvement (NRI) and C-indices. 184 participants experienced a cardiovascular event during a median follow-up of 2.9 years. Age, pack-years and smoking status adjusted hazard ratios were 0.992 (95 % confidence interval (CI) 0.985-0.999) for FEV{sub 1}%predicted, 1.000 (95%CI 0.986-1.015) for FEV{sub 1}/FVC, 1.014 (95%CI 1.005-1.023) for perc15 per 10 HU, and 1.269 (95%CI 1.024-1.573) for pi10 per 1 mm. The incremental C-index (<0.015) and NRI (<2.8 %) were minimal. Coronary artery calcium volume had a hazard ratio of 1.046 (95%CI 1.034-1.058) per 100 mm{sup 3}, an increase in C-index of 0.076 and an NRI of 16.9 % (P < 0.0001). Pulmonary CT biomarkers and spirometry measurements were significantly associated with cardiovascular events, but did not contain clinically relevant independent prognostic information for cardiovascular events. (orig.)

  7. Insurance Coverage for CT Colonography Screening: Impact on Overall Colorectal Cancer Screening Rates.

    Science.gov (United States)

    Smith, Maureen A; Weiss, Jennifer M; Potvien, Aaron; Schumacher, Jessica R; Gangnon, Ronald E; Kim, David H; Weeth-Feinstein, Lauren A; Pickhardt, Perry J

    2017-09-01

    Purpose To compare overall colorectal cancer (CRC) screening rates for patients who were eligible and due for CRC screening and who were with and without insurance coverage for computed tomographic (CT) colonography for CRC screening. Materials and Methods The institutional review board approved this retrospective cohort study, with a waiver of consent. This study used longitudinal electronic health record data from 2005 through 2010 for patients managed by one of the largest multispecialty physician groups in the United States. It included 33 177 patients under age 65 who were eligible and due for CRC screening and managed by the participating health system. Stratified Cox regression models provided propensity-adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) for the relationship between CT colonography coverage and CRC screening. Results After adjustment, patients who had insurance coverage for CT colonography and were due for CRC screening had a 48% greater likelihood of being screened for CRC by any method compared with those without coverage who were due for CRC screening (HR, 1.48; 95% CI: 1.41, 1.55). Similarly, patients with CT colonography coverage had a greater likelihood of being screened with CT colonography (HR, 8.35; 95% CI: 7.11, 9.82) and with colonoscopy (HR, 1.38; 95% CI: 1.31, 1.45) but not with fecal occult blood test (HR, 1.00; 95% CI: 0.91, 1.10) than those without such insurance coverage. Conclusion Insurance coverage of CT colonography for CRC screening was associated with a greater likelihood of a patient being screened and a greater likelihood of being screened with a test that helps both to detect cancer and prevent cancer from developing (CT colonography or colonoscopy). (©) RSNA, 2017.

  8. CT screening of vertebrarterial circulatory disorder

    Energy Technology Data Exchange (ETDEWEB)

    Yoshida, Shigeru; Toyoda, Keiko; Moriyama, Hiroshi [Jikei Univ., Tokyo (Japan). School of Medicine

    2001-09-01

    The frequency of MR angiography (MRA) used to diagnose vertebrobasiliar insufficiency appears high. Findings of abnormality by MRA show cases with maldescription of hemivertebral artery. In such cases, it is unclear whether these are due to anaplasia of the vertebral artery or to the existence of morbid constriction, thus requiring confirmation by a vertebral arteriography (VAG). We observe the vascular morphology of vertebral artery by Computed tomography (CT) scanning for screening circulatory disorders. In photography and CT scan reading, the region was severally photographed between foramen magnum and aortic arch by plain CT and contrast CT at a slice of 5 mm. The constrictive region of the vertebral artery was estimated by comparing plain and contrast CT. Subjects were 34 clinical cases of vascular maldescription in the vertebrobasilar artery, nearly no blood vessel description, or blood vessel winding or inclination. We determined the constrictive morbid state of the vertebral or subclavian artery and cervical vertebra deformity. In findings of maldescription by MRA, it was suggested that discrimination is feasible to a certain degree, whether the vertebral artery has a morbid constrictive region or due to anaplasia. Our results suggest that screening by CT scanning may be more efficient than that by MRA. (author)

  9. The Danish randomized lung cancer CT screening trial

    DEFF Research Database (Denmark)

    Pedersen, Jesper H; Ashraf, Haseem; Dirksen, Asger

    2009-01-01

    INTRODUCTION: Lung cancer screening with low dose computed tomography (CT) has not yet been evaluated in randomized clinical trials, although several are underway. METHODS: In The Danish Lung Cancer Screening Trial, 4104 smokers and previous smokers from 2004 to 2006 were randomized to either...... lung cancer. Ten of these had stage I disease. Eleven of 17 lung cancers at baseline were treated surgically, eight of these by video assisted thoracic surgery resection. CONCLUSIONS: Screening may facilitate minimal invasive treatment and can be performed with a relatively low rate of false......-positive screen results compared with previous studies on lung cancer screening....

  10. Estimating radiation risk induced by CT screening for Korean population

    Science.gov (United States)

    Yang, Won Seok; Yang, Hye Jeong; Min, Byung In

    2017-02-01

    The purposes of this study are to estimate the radiation risks induced by chest/abdomen computed tomography (CT) screening for healthcare and to determine the cancer risk level of the Korean population compared to other populations. We used an ImPACT CT Patient Dosimetry Calculator to compute the organ effective dose induced by CT screening (chest, low-dose chest, abdomen/pelvis, and chest/abdomen/pelvis CT). A risk model was applied using principles based on the BEIR VII Report in order to estimate the lifetime attributable risk (LAR) using the Korean Life Table 2010. In addition, several countries including Hong Kong, the United States (U.S.), and the United Kingdom, were selected for comparison. Herein, each population exposed radiation dose of 100 mSv was classified according to country, gender and age. For each CT screening the total organ effective dose calculated by ImPACT was 6.2, 1.5, 5.2 and 11.4 mSv, respectively. In the case of Korean female LAR, it was similar to Hong Kong female but lower than those of U.S. and U.K. females, except for those in their twenties. The LAR of Korean males was the highest for all types of CT screening. However, the difference of the risk level was negligible because of the quite low value.

  11. Low-dose CT screening in an Asian population with diverse risk for lung cancer: A retrospective cohort study

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    Yi, Chin A. [Sungkyunkwan University School of Medicine, Department of Radiology and Center for Imaging Science, Seoul (Korea, Republic of); Lee, Kyung Soo [Sungkyunkwan University School of Medicine, Department of Radiology and Center for Imaging Science, Seoul (Korea, Republic of); Sungkyunkwan University School of Medicine, Department of Radiology, Samsung Medical Center, Seoul (Korea, Republic of); Shin, Myung-Hee; Cho, Yun Yung [Sungkyunkwan University School of Medicine, Department of Social and Preventive Medicine, Seoul (Korea, Republic of); Choi, Yoon-Ho [Sungkyunkwan University School of Medicine, Center for Health Promotion, Seoul (Korea, Republic of); Kwon, O. Jung [Sungkyunkwan University School of Medicine, Division of Pulmonary and Critical Care Medicine, Department of Medicine, Samsung Medical Center, Seoul (Korea, Republic of); Shin, Kyung Eun [Sungkyunkwan University School of Medicine, Department of Radiology and Center for Imaging Science, Seoul (Korea, Republic of); Kyung Hee University Hospital, Department of Diagnostic Radiology, Seoul (Korea, Republic of)

    2015-08-15

    To evaluate the performance of low-dose CT (LDCT) screening for lung cancer (LCA) detection in an Asian population with diverse risks for LCA. LCA screening was performed in 12,427 symptomless Asian subjects using either LDCT (5,771) or chest radiography (CXR) (6,656) in a non-trial setting. Subjects were divided into high-risk and non-high-risk groups. Data were collected on the number of patients with screening-detected LCAs and their survival in order to compare outcomes between LDCT and CXR screening with the stratification of risks considering age, sex and smoking status. In the non-high-risk group, a significant difference was observed for the detection of lung cancer (adjusted OR, 5.07; 95 % CI, 2.72-9.45) and survival (adjusted HR of LCA survival between LDCT vs. CXR group, 0.08; 95 % CI, 0.01-0.62). No difference in detection or survival of LCA was noticed in the high-risk group. LCAs in the non-high-risk group were predominantly adenocarcinomas (96 %), and more likely to be part-solid or non-solid compared with those in the high-risk group (p = 0.023). In the non-high-risk group, LDCT helps detect more LCAs and offers better survival than CXR screening, due to better detection of part solid or non-solid lung adenocarcinomas. (orig.)

  12. Deep convolutional neural networks for automatic coronary calcium scoring in a screening study with low-dose chest CT

    Science.gov (United States)

    Lessmann, Nikolas; Išgum, Ivana; Setio, Arnaud A. A.; de Vos, Bob D.; Ciompi, Francesco; de Jong, Pim A.; Oudkerk, Matthjis; Mali, Willem P. Th. M.; Viergever, Max A.; van Ginneken, Bram

    2016-03-01

    The amount of calcifications in the coronary arteries is a powerful and independent predictor of cardiovascular events and is used to identify subjects at high risk who might benefit from preventive treatment. Routine quantification of coronary calcium scores can complement screening programs using low-dose chest CT, such as lung cancer screening. We present a system for automatic coronary calcium scoring based on deep convolutional neural networks (CNNs). The system uses three independently trained CNNs to estimate a bounding box around the heart. In this region of interest, connected components above 130 HU are considered candidates for coronary artery calcifications. To separate them from other high intensity lesions, classification of all extracted voxels is performed by feeding two-dimensional 50 mm × 50 mm patches from three orthogonal planes into three concurrent CNNs. The networks consist of three convolutional layers and one fully-connected layer with 256 neurons. In the experiments, 1028 non-contrast-enhanced and non-ECG-triggered low-dose chest CT scans were used. The network was trained on 797 scans. In the remaining 231 test scans, the method detected on average 194.3 mm3 of 199.8 mm3 coronary calcifications per scan (sensitivity 97.2 %) with an average false-positive volume of 10.3 mm3 . Subjects were assigned to one of five standard cardiovascular risk categories based on the Agatston score. Accuracy of risk category assignment was 84.4 % with a linearly weighted κ of 0.89. The proposed system can perform automatic coronary artery calcium scoring to identify subjects undergoing low-dose chest CT screening who are at risk of cardiovascular events with high accuracy.

  13. Predicting Future Hip Fractures on Routine Abdominal CT Using Opportunistic Osteoporosis Screening Measures: A Matched Case-Control Study.

    Science.gov (United States)

    Lee, Scott J; Anderson, Paul A; Pickhardt, Perry J

    2017-08-01

    Hip fracture is a major consequence of low bone mineral density, which is treatable but underdiagnosed. The purpose of this case-control study is to determine whether lumbar vertebral trabecular attenuation, vertebral compression fractures, and femoral neck T scores readily derived from abdominopelvic CT scans obtained for various indications are associated with future hip fragility fracture. A cohort of 204 patients with hip fracture (130 women and 74 men; mean age, 74.3 years) who had undergone abdominopelvic CT before fracture occurred (mean interval, 24.8 months) was compared with an age- and sex-matched control cohort without hip fracture. L1 trabecular attenuation, vertebral compression fractures of grades 2 and 3, and femoral neck T scores derived from asynchronous quantitative CT were recorded. The presence of one or more clinical risk factor for fracture was also recorded. Multivariate logistic regression models were used to determine the association of each measurement with the occurrence of hip fracture. The mean L1 trabecular attenuation value, the presence of one or more vertebral compression fracture, and CT-derived femoral neck T scores were all significantly different in patients with hip fracture versus control subjects (p hip fracture outcome after adjustments were made for age, sex, and the presence of one or more clinical risk factor. L1 trabecular attenuation and CT-derived femoral neck T scores showed moderate accuracy in differentiating case and control patients (AUC, 0.70 and 0.78, respectively). L1 trabecular attenuation, CT-derived femoral neck T scores, and the presence of at least one vertebral compression fracture on CT are all associated with future hip fragility fracture in adults undergoing routine abdominopelvic CT for a variety of conditions.

  14. Optimization of nodule management in CT lung cancer screening

    NARCIS (Netherlands)

    Heuvelmans, Marjolein Anne

    2015-01-01

    Lung cancer is the leading cancer-related cause of death. Through computed tomography (CT) screening, cancer can be detected at the earliest stage, with a much greater probability of cure. After the positive outcome of the US National Lung Screening Trial (NLST), screening with low-dose CT in heavy

  15. Population screening for colorectal cancer by flexible sigmoidoscopy or CT colonography: study protocol for a multicenter randomized trial.

    Science.gov (United States)

    Regge, Daniele; Iussich, Gabriella; Senore, Carlo; Correale, Loredana; Hassan, Cesare; Bert, Alberto; Montemezzi, Stefania; Segnan, Nereo

    2014-03-28

    Colorectal cancer (CRC) is the second most prevalent type of cancer in Europe. A single flexible sigmoidoscopy (FS) screening at around the age of 60 years prevents about one-third of CRC cases. However, FS screens only the distal colon, and thus mortality from proximal CRC is unaffected. Computed tomography colonography (CTC) is a highly accurate examination that allows assessment of the entire colon. However, the benefit of CTC testing as a CRC screening test is uncertain. We designed a randomized trial to compare participation rate, detection rates, and costs between CTC (with computer-aided detection) and FS as primary tests for population-based screening. An invitation letter to participate in a randomized screening trial comparing CTC versus FS will be mailed to a sample of 20,000 people aged 58 or 60 years, living in the Piedmont region and the Verona district of Italy. Individuals with a history of CRC, adenomas, inflammatory bowel disease, or recent colonoscopy, or with two first-degree relatives with CRC will be excluded from the study by their general practitioners. Individuals responding positively to the invitation letter will be then randomized to the intervention group (CTC) or control group (FS), and scheduled for the screening procedure. The primary outcome parameter of this part of the trial is the difference in advanced neoplasia detection between the two screening tests. Secondary outcomes are cost-effectiveness analysis, referral rates for colonoscopy induced by CTC versus FS, and the expected and perceived burden of the procedures. To compare participation rates for CTC versus FS, 2,000 additional eligible subjects will be randomly assigned to receive an invitation for screening with CTC or FS. In the CTC arm, non-responders will be offered fecal occult blood test (FOBT) as alternative screening test, while in the FS arm, non-responders will receive an invitation letter to undergo screening with either FOBT or CTC. Data on reasons for

  16. Screenings of lung cancer with low dose spiral CT: results of a three year pilot study and design of the randomised controlled trial Italung-CT; Screening della neoplasia polmonare con TC spirale a bassa dose: risultati di uno studio pilota triennale e disegno dello studio clinico randomizzato Italung-CT

    Energy Technology Data Exchange (ETDEWEB)

    Picozzi, Giulia [Firenze Univ., Firenze (Italy). Radiodiagnostica I-Dipartimento di Fisiopatologia Clinica; Paci, Enrico [Azienda Ospedaliera Universitaria di Careggi, Firenze (Italy). Unita' di Epidemiologia Clinica e Descrittiva Centro per lo Studio e la Prevenzione Oncologica; Lopes Pegna, Andrea [Azienda Ospedaliera Universitaria di Careggi, Firenze (Italy). U.O. Pneumologia] [and others

    2005-02-01

    Purpose: To report the results of a three-year observational pilot study of lung cancer screening with low dose computed tomography (CT) and to present the study design of a randomised clinical trial named as Italung CT. Materials and methods: Sixty (47 males and 13 females, mean age 64{+-}4.5 years) heavy smokers (at least 20 packs-year) underwent three low-dose spiral CT screening tests one year apart on a single slice or multislice CT scanner. Indeterminate nodules were managed according to the recommendations of the Early Lung Cancer Action Project. Results: Indeterminate nodules were observed in 33 (55%) of the subjects (60% at the baseline screening test, 24% at the first annual test and 16% at the second annual test). The size of the largest indeterminate nodule was <5mm in diameter in 20 subjects. 10 of whom showed the nodule at the baseline test. Forty-five subjects (75%) completed the first annual test and 42 (70%) the second annual test. One (1.6%) prevalent lung cancer (adenosquamous carcinoma) and one (2.2%) incident lung cancer (small cell cancer at the first annual examination) were observed, as well as pulmonary localisation of Hodgkin's lymphoma (at the second annual test). In addition, one subject underwent lung surgery for a chondromatous hamartoma. Conclusions: The results of the pilot study are substantially in line with those of other observational studies of greater sample size. This justifies optimism about the reliability of the results in the screened arm of the Italung Ct trial which hast just began. [Italian] Scopo: Riportare i risultati di uno studio pilota osservazionale di screening della neoplasia polmonare con TC a bassa dose della durata di tre anni e presentare il disegno dello studio clinico randomizzato Italung-CT. Materiale e metodi: Sessanta (47 uomini e 13 donne, eta' media 64{+-}4,5 anni) forti fumatori (almeno 20 pacchetti/anno) sono stati sottoposti ad un esame basale e a due controlli annuali con TC single o

  17. Healthcare costs in the Danish randomised controlled lung cancer CT-screening trial

    DEFF Research Database (Denmark)

    Rasmussen, J.F.; Siersma, V.; Pedersen, Jesper H.;

    2014-01-01

    OBJECTIVES: Low dose computerised tomography (CT) screening for lung cancer can reduce lung-cancer-specific mortality. The objective of this study was to analyse healthcare costs and healthcare utilisation of participants in the Danish lung cancer CT-screening trial (DLCST). MATERIALS AND METHODS...

  18. Contamination during 4 years of annual CT screening in the Danish Lung Cancer Screening Trial (DLCST)

    DEFF Research Database (Denmark)

    Saghir, Zaigham; Ashraf, Haseem; Dirksen, Asger

    2010-01-01

    Contamination, defined as screening in the control arm, may dilute the statistical power of randomised screening trials. We investigated the rate of contamination in DLCST during 4 years of annual CT screening.......Contamination, defined as screening in the control arm, may dilute the statistical power of randomised screening trials. We investigated the rate of contamination in DLCST during 4 years of annual CT screening....

  19. Development of lung cancer CT screening operating support system

    Science.gov (United States)

    Ishigaki, Rikuta; Hanai, Kozou; Suzuki, Masahiro; Kawata, Yoshiki; Niki, Noboru; Eguchi, Kenji; Kakinuma, Ryutaro; Moriyama, Noriyuki

    2009-02-01

    In Japan, lung cancer death ranks first among men and third among women. Lung cancer death is increasing yearly, thus early detection and treatment are needed. For this reason, CT screening for lung cancer has been introduced. The CT screening services are roughly divided into three sections: office, radiology and diagnosis sections. These operations have been performed through paper-based or a combination of paper-based and an existing electronic health recording system. This paper describes an operating support system for lung cancer CT screening in order to make the screening services efficient. This operating support system is developed on the basis of 1) analysis of operating processes, 2) digitalization of operating information, and 3) visualization of operating information. The utilization of the system is evaluated through an actual application and users' survey questionnaire obtained from CT screening centers.

  20. NELSON lung cancer screening study

    NARCIS (Netherlands)

    Y. Zhao (Yingru); X. Xie (Xueqian); H.J. de Koning (Harry); W.P. Mali (Willem); R. Vliegenthart (Rozemarijn); M. Oudkerk (Matthijs)

    2011-01-01

    textabstractThe Dutch-Belgian Randomized Lung Cancer Screening Trial (Dutch acronym: NELSON study) was designed to investigate whether screening for lung cancer by low-dose multidetector computed tomography (CT) in high-risk subjects will lead to a decrease in 10-year lung cancer mortality of at

  1. Screening for lungecancer med lavdosis CT - Danske og udenlandske resultater

    DEFF Research Database (Denmark)

    Saghir, Z.; Dirksen, A.; Ashraf, H.;

    2015-01-01

    Lung cancer is the cancer type that causes the largest number of deaths in Denmark. With advances in medical imaging and widespread use of computed tomography (CT), it is possible to detect even small abnormalities in lung tissue. This has led to a great interest in lung cancer screening with low......-dose CT and launching of randomised screening trials worldwide. This paper gives an overview of the current lung cancer screening trials in Denmark and internationally and focuses on main lung cancer findings and mortality results.......Lung cancer is the cancer type that causes the largest number of deaths in Denmark. With advances in medical imaging and widespread use of computed tomography (CT), it is possible to detect even small abnormalities in lung tissue. This has led to a great interest in lung cancer screening with low...

  2. The impact of radiologists' expertise on screen results decisions in a CT lung cancer screening trial

    Energy Technology Data Exchange (ETDEWEB)

    Heuvelmans, Marjolein A.; Vliegenthart, Rozemarijn [University of Groningen, University Medical Center Groningen, Center for Medical Imaging - North East Netherlands, Groningen (Netherlands); University of Groningen / University Medical Center Groningen, Department of Radiology, Groningen (Netherlands); Oudkerk, Matthijs [University of Groningen, University Medical Center Groningen, Center for Medical Imaging - North East Netherlands, Groningen (Netherlands); Jong, Pim A. de; Mali, Willem P. [University Medical Center Utrecht, Department of Radiology, Utrecht (Netherlands); Groen, Harry J.M. [University of Groningen, University Medical Center Groningen, Department of Pulmonology, Groningen (Netherlands)

    2014-11-04

    To evaluate the impact of radiological expertise on screen result decisions in a CT lung cancer screening trial. In the NELSON lung cancer screening trial, the baseline CT result was based on the largest lung nodule's volume. The protocol allowed radiologists to manually adjust screen results in cases of high suspicion of benign or malignant nodule nature. Participants whose baseline CT result was based on a solid or part-solid nodule were included in this study. Adjustments by radiologists at baseline were evaluated. Histology was the reference for diagnosis or to confirm benignity and stability on subsequent CT examinations. A total of 3,318 participants (2,796 male, median age 58.0 years) were included. In 195 participants (5.9 %) the initial baseline screen result was adjusted by the radiologist. Adjustment was downwards from positive or indeterminate to negative in two and 119 participants, respectively, and from positive to indeterminate in 65 participants. None of these nodules turned out to be malignant. In 9/195 participants (4.6 %) the screen result was adjusted upwards from negative to indeterminate or indeterminate to positive; two nodules were malignant. In one in 20 cases of baseline lung cancer screening, nodules were reclassified by the radiologist, leading to a reduction of false-positive screen results. (orig.)

  3. Lung Cancer Screening with Low Dose CT

    Science.gov (United States)

    Caroline, Chiles

    2014-01-01

    SUMMARY The announcement of the results of the NLST, showing a 20% reduction in lung-cancer specific mortality with LDCT screening in a high risk population, marked a turning point in lung cancer screening. This was the first time that a randomized controlled trial had shown a mortality reduction with an imaging modality aimed at early detection of lung cancer. Current guidelines endorse LDCT screening for smokers and former smokers ages 55 to 74, with at least a 30 pack year smoking history. Adherence to published algorithms for nodule follow-up is strongly encouraged. Future directions for screening research include risk stratification for selection of the screening population, and improvements in the diagnostic follow-up for indeterminate pulmonary nodules. As with screening for other malignancies, screening for lung cancer with LDCT has revealed that there are indolent lung cancers which may not be fatal. More research is necessary if we are to maximize the risk-benefit ratio in lung cancer screening. PMID:24267709

  4. Multislice CT as a Primary Screening Tool for the Prediction of an Involved Mesorectal Fascia and Distant Metastases in Primary Rectal Cancer : A Multicenter Study

    NARCIS (Netherlands)

    Wolberink, Steven V. R. C.; Beets-Tan, Regina G. H.; de Haas-Kock, Danielle F. M.; van de Jagt, Eric J.; Span, Mark M.; Wiggers, Theo

    2009-01-01

    PURPOSE: The purposes of this study were to assess whether multislice CT can identify tumors having a free or involved circumferential margin, to investigate the additional role of multislice CT as a "one-stop shopping'' staging tool for staging nodal and distant metastases. METHODS: A total of 250

  5. Multislice CT as a Primary Screening Tool for the Prediction of an Involved Mesorectal Fascia and Distant Metastases in Primary Rectal Cancer : A Multicenter Study

    NARCIS (Netherlands)

    Wolberink, Steven V. R. C.; Beets-Tan, Regina G. H.; de Haas-Kock, Danielle F. M.; van de Jagt, Eric J.; Span, Mark M.; Wiggers, Theo

    PURPOSE: The purposes of this study were to assess whether multislice CT can identify tumors having a free or involved circumferential margin, to investigate the additional role of multislice CT as a "one-stop shopping'' staging tool for staging nodal and distant metastases. METHODS: A total of 250

  6. CT screening for lung cancer brings forward early disease. The Randomised Danish Lung Cancer Screening Trial (DLCST)

    DEFF Research Database (Denmark)

    Saghir, Zaigham; Dirksen, Asger; Ashraf, Haseem

    2012-01-01

    BackgroundThe effects of low-dose CT screening on disease stage shift, mortality and overdiagnosis are unclear. Lung cancer findings and mortality rates are reported at the end of screening in the Danish Lung Cancer Screening Trial.Methods4104 men and women, healthy heavy smokers/former smokers...... increase and/or volume doubling time15 mm were referred for diagnostic workup. In the control group, lung cancers were diagnosed and treated outside the study by the usual clinical practice.ResultsParticipation rates were high in both groups (screening: 95.5%; control: 93.0%; p...

  7. Lung cancer screening with thoracic X-ray and CT. Current situation; Lungenkarzinomscreening mit Roentgenthorax oder CT. Aktuelle Datenlage

    Energy Technology Data Exchange (ETDEWEB)

    Stackelberg, O. von; Kauczor, H.U. [Universitaetsklinikum Heidelberg, Diagnostische und Interventionelle Radiologe, Heidelberg (Germany); Translationales Lungen Forschungszentrum Heidelberg (TLRC), Mitglied des Deutschen Zentrums fuer Lungenforschung (DZL), Heidelberg (Germany)

    2016-09-15

    Attempts at the early detection of lung cancer using imaging methods began as far back as the 1950s. Several studies attempted to demonstrate a reduction of lung cancer mortality by chest radiography screening but all were unsuccessful. Even the first small screening studies using computed tomography (CT) could not demonstrate a reduction in lung cancer-specific mortality until in 2011 the results of the largest randomized controlled low-dose CT screening study in the USA (NLST) were published. The NLST results could show a significant 20 % reduction of lung cancer mortality in elderly and heavy smokers using CT. Confirmation of the NLST results are urgently needed so that the data of the largest European study (NELSON) are eagerly awaited. Pooled with the data from several smaller European studies these results will provide important information and evidence for the establishment of future CT screening programs in Europe. Randomized controlled trials are the basis of evidence-based medicine; therefore, the positive results of the methodologically very good NLST study cannot be ignored, even if it is the only such study completed so far with highly convincing conclusions. The NLST results clearly demonstrate that positive effects for the health of the population can only be expected if the processes are clearly defined and the quality is assured. (orig.) [German] Bestrebungen zur Frueherkennung von Lungenkrebs mit bildgebenden Methoden gibt es schon lange. Alle Studien, die eine Reduktion der Lungenkrebsmortalitaet mittels Roentgenthoraxscreening nachzuweisen versuchten, scheiterten. Auch die ersten kleineren Screeningstudien mit der CT konnten keine Reduktion der Lungenkrebssterblichkeit nachweisen, bis 2011 die Ergebnisse der bisher groessten randomisierten kontrollierten Niedrigdosis-CT-Screeningstudie (NLST) aus den USA veroeffentlicht wurden. Diese konnten eine signifikante 20 %ige Reduktion der Lungenkrebssterblichkeit bei Personen, die aelter und starke

  8. Small pulmonary nodules in baseline and incidence screening rounds of low-dose CT lung cancer screening.

    Science.gov (United States)

    Walter, Joan E; Heuvelmans, Marjolein A; Oudkerk, Matthijs

    2017-02-01

    Currently, lung cancer screening by low-dose computed tomography (LDCT) is widely recommended for high-risk individuals by US guidelines, but there still is an ongoing debate concerning respective recommendations for European countries. Nevertheless, the available data regarding pulmonary nodules released by lung cancer screening studies could improve future screening guidelines, as well as the clinical practice of incidentally detected pulmonary nodules on routine CT scans. Most lung cancer screening trials present results for baseline and incidence screening rounds separately, clustering pulmonary nodules initially found at baseline screening and newly detected pulmonary nodules after baseline screening together. This approach does not appreciate possible differences among pulmonary nodules detected at baseline and firstly detected at incidence screening rounds and is heavily influenced by methodological differences of the respective screening trials. This review intends to create a basis for assessing non-calcified pulmonary nodules detected during LDCT lung cancer screening in a more clinical relevant manner. The aim is to present data of non-calcified pulmonary baseline nodules and new non-calcified pulmonary incident nodules without clustering them together, thereby also simplifying translation to the clinical practice of incidentally detected pulmonary nodules. Small pulmonary nodules newly detected at incidence screening rounds of LDCT lung cancer screening may possess a greater lung cancer probability than pulmonary baseline nodules at a smaller size, which is essential for the development of new guidelines.

  9. Screening for lung cancer with low-dose CT.

    Science.gov (United States)

    Coche, E

    2008-01-01

    Lung cancer represents the leading cause of cancer-related mortality in the world. In the past, many attempts were made to detect the disease at an early stage and subsequently reduce its mortality. Chest X-ray was abandoned for this purpose. For several years low-dose computed tomography has been introduced as a potential tool for early screening in a high-risk population. As demonstrated in several papers, the task is not easy and researchers are faced with many difficulties. This paper reviews mainly the role of low-dose CT for early cancer screening. Results of past and current trials, controversies related to the high rate of lung nodules, cost-effectiveness, and delivered radiation dose to the patient are presented. Finally some limitations of low dose CT for lung cancer detection are explained.

  10. CT characteristics of resolving ground-glass opacities in a lung cancer screening programme

    Energy Technology Data Exchange (ETDEWEB)

    Felix, L.; Serra-Tosio, G. [Clinique Universitaire de Radiologie et Imagerie Medicale, Universite Grenoble I, CHU Grenoble (France); Lantuejoul, S. [Departement d' anatomie Pathologique, Universite Grenoble I, CHU Grenoble (France); INSERM U823, A Bonniot Institute, La Tronche (France); Timsit, J.F. [INSERM U823, A Bonniot Institute, La Tronche (France); Moro-Sibilot, D.; Brambilla, C. [INSERM U823, A Bonniot Institute, La Tronche (France); Clinique Universitaire Pneumologique, Universite Grenoble I, CHU Grenoble (France); Ferretti, G.R., E-mail: gferretti@chu-grenoble.fr [Clinique Universitaire de Radiologie et Imagerie Medicale, Universite Grenoble I, CHU Grenoble (France); INSERM U823, A Bonniot Institute, La Tronche (France)

    2011-03-15

    Purpose: This study aimed at evaluating the computed tomography (CT) characteristics of resolving localized ground-glass opacities (GGOs) in a screening programme for lung cancer. Material and methods: 280 patients at high-risk for lung cancer (221 men, 59 women; mean age, 58.6 years), divided into four groups (lung cancer history (n = 83), head and neck cancer history (n = 63), symptomatic (n = 88) and asymptomatic (n = 46) cigarette smokers), were included in a prospective trial with annual low-dose CT for lung cancer screening. We retrospectively reviewed all localized GGOs, analyzed the CT characteristics on initial CT scans and changes during follow-up (median 29.1 months). Variables associated with resolution of GGOs were tested using chi-square or Mann-Whitney tests. Results: A total of 75 GGOs were detected in 37 patients; 54.7% were present at baseline and 45.3% appeared on annual CT. During follow-up, 56.2% persisted and 43.8% disappeared. The resolving localized GGOs were significantly more often lobular GGOs (p = 0.006), polygonal in shape (p = 0.02), mixed (p = 0.003) and larger (p < 0.0001) than non-resolving localized GGOs. Conclusion: Localized GGOs are frequent and many disappeared on follow-up. CT characteristics of resolving GGOs show significant differences compared to persistent ones. This study emphasizes the importance of short-term CT follow-up in subjects with localized GGOs.

  11. [Lung cancer screening with low-dose thoracic CT-scan in the Somme area].

    Science.gov (United States)

    Leleu, O; Auquier, M; Carre, O; Chauffert, B; Dubreuil, A; Petigny, V; Trancart, B; Berna, P; Jounieaux, V

    2017-03-01

    This feasibility trial proposes to set up in the department of the Somme an annual screening for lung cancer with low-dose thoracic CT. It responds to the first objective of the third cancer plan and follows the publication of the results of the National Lung Screening Trial in 2011. The method of this study is to use the existing networks among and between healthcare professionals and the departmental cancer screening structure. The inclusion criteria will be those of the National Lung Screening Trial. Screening will be proposed by treating physicians and chest physicians. The CT-scan will be performed in radiological centers that adhere to the good practice charter for low radiation scanning. A copy of CT results will be sent to the departmental structure of cancer screening (ADEMA80) which will ensure traceability and will perform statistical analysis. The study received funding from the Agence régionale de santé de la Picardie and la ligue contre le cancer. The primary endpoints of this screening will be the number of cancers diagnosed and the survival of the patients. The follow-up of positive examinations, delays in management and the level of participation will also be assessed. Copyright © 2016 SPLF. Published by Elsevier Masson SAS. All rights reserved.

  12. Coronary artery calcification scoring in low-dose ungated CT screening for lung cancer: interscan agreement.

    NARCIS (Netherlands)

    Jacobs, P.C.; Isgum, I.; Gondrie, M.J.; Mali, W.P.Th.; Ginneken, B. van; Prokop, M.; Graaf, Y. van der

    2010-01-01

    OBJECTIVE: In previous studies detection of coronary artery calcification (CAC) with low-dose ungated MDCT performed for lung cancer screening has been compared with detection with cardiac CT. We evaluated the interscan agreement of CAC scores from two consecutive low-dose ungated MDCT examinations.

  13. Coronary Artery Calcification Scoring in Low-Dose Ungated CT Screening for Lung Cancer : Interscan Agreement

    NARCIS (Netherlands)

    Jacobs, Peter C. A.; Isgum, Ivana; Gondrie, Martijn J. A.; Mali, Willem P. Th. M.; van Ginneken, Bram; Prokop, Mathias; van der Graaf, Yolanda

    2010-01-01

    OBJECTIVE. In previous studies detection of coronary artery calcification (CAC) with low-dose ungated MDCT performed for lung cancer screening has been compared with detection with cardiac CT. We evaluated the interscan agreement of CAC scores from two consecutive low-dose ungated MDCT examinations.

  14. Metal based pharmacologically active agents: Synthesis, structural characterization, molecular modeling, CT-DNA binding studies and in vitro antimicrobial screening of iron(II) bromosalicylidene amino acid chelates

    Science.gov (United States)

    Abdel-Rahman, Laila H.; El-Khatib, Rafat M.; Nassr, Lobna A. E.; Abu-Dief, Ahmed M.; Ismael, Mohamed; Seleem, Amin Abdou

    2014-01-01

    In recent years, great interest has been focused on Fe(II) Schiff base amino acid complexes as cytotoxic and antitumor drugs. Thus a series of new iron(II) complexes based on Schiff bases amino acids ligands have been designed and synthesized from condensation of 5-bromosalicylaldehyde (bs) and α-amino acids (L-alanine (ala), L-phenylalanine (phala), L-aspartic acid (aspa), L-histidine (his) and L-arginine (arg)). The structure of the investigated iron(II) complexes was elucidated using elemental analyses, infrared, ultraviolet-visible, thermogravimetric analysis, as well as conductivity and magnetic susceptibility measurements. Moreover, the stoichiometry and the stability constants of the prepared complexes have been determined spectrophotometrically. The results suggest that 5-bromosalicylaldehyde amino acid Schiff bases (bs:aa) behave as dibasic tridentate ONO ligands and coordinate to Fe(II) in octahedral geometry according to the general formula [Fe(bs:aa)2]ṡnH2O. The conductivity values between 37 and 64 ohm-1 mol-1 cm2 in ethanol imply the presence of nonelectrolyte species. The structure of the complexes was validated using quantum mechanics calculations based on accurate DFT methods. Geometry optimization of the Fe-Schiff base amino acid complexes showed that all complexes had octahedral coordination. In addition, the interaction of these complexes with (CT-DNA) was investigated at pH = 7.2, by using UV-vis absorption, viscosity and agarose gel electrophoresis measurements. Results indicated that the investigated complexes strongly bind to calf thymus DNA via intercalative mode and showed a different DNA binding according to the sequence: bsari > bshi > bsali > bsasi > bsphali. Moreover, the prepared compounds are screened for their in vitro antibacterial and antifungal activity against three types of bacteria, Escherichia coli, Pseudomonas aeruginosa and Bacillus cereus and three types of anti fungal cultures, Penicillium purpurogenium, Aspergillus

  15. Change descriptors for determining nodule malignancy in national lung screening trial CT screening images

    Science.gov (United States)

    Geiger, Benjamin; Hawkins, Samuel; Hall, Lawrence O.; Goldgof, Dmitry B.; Balagurunathan, Yoganand; Gatenby, Robert A.; Gillies, Robert J.

    2016-03-01

    Pulmonary nodules are effectively diagnosed in CT scans, but determining their malignancy has been a challenge. The rate of change of the volume of a pulmonary nodule is known to be a prognostic factor for cancer development. In this study, we propose that other changes in imaging characteristics are similarly informative. We examined the combination of image features across multiple CT scans, taken from the National Lung Screening Trial, with individual scans of the same patient separated by approximately one year. By subtracting the values of existing features in multiple scans for the same patient, we were able to improve the ability of existing classification algorithms to determine whether a nodule will become malignant. We trained each classifier on 83 nodules determined to be malignant by biopsy and 172 nodules determined to be benign by their clinical stability through two years of no change; classifiers were tested on 77 malignant and 144 benign nodules, using a set of features that in a test-retest experiment were shown to be stable. An accuracy of 83.71% and AUC of 0.814 were achieved with the Random Forests classifier on a subset of features determined to be stable via test-retest reproducibility analysis, further reduced with the Correlation-based Feature Selection algorithm.

  16. Cancerogenesis Risks between 64 and 320 Row Detector CT for Coronary CTA Screening

    Directory of Open Access Journals (Sweden)

    Atif N Khan

    2014-01-01

    Full Text Available Objectives: This study compares cancerogenesis risks posed by the 64 row detector and the 320 row detector computed tomography scanners used during coronary computed tomography angiography (CCTA following decennial screening guidelines. Material and Methods: Data of the radiation absorbed after CCTA by lung, thyroid, and female breast in patients between 50 and 70 years of age obtained from prior published literature for the 64 row CT scanner were compared with data from our study using 320 row detector CT scanner. Data from the 64 row and the 320 row detector CT scanners was used to determine lifetime attributable risks (LAR of cancer based on the biological effects of ionizing radiation (BEIR VII report. Results: The relative reduction of LAR (% for 50-, 60-, and 70-year-old patients undergoing scanning with the 320 row detector CT scanner was 30% lower for lung, and more than 50% lower for female breast when compared with results from 64 row detector CT scanner. The use of 320 row detector CT would result in a combined cumulative cancer incidence of less than 1/500 for breast in women and less than 1/1000 for lung in men; By comparison, this is much lower than other more common risk factors: 16-fold for lung cancer in persistent smokers, 2-fold for breast cancer with a first degree family member history of breast cancer, and 10-fold for thyroid cancer with a family member with thyroid cancer. Decennial screening would benefit at least 355,000 patients from sudden cardiac death each year, 94% of whom have significant coronary artery disease, with at least one stenosis >75%. LAR for thyroid cancer was negligible for both scanners. Conclusion: Lung and female breast LAR reductions with 320 row detector compared with 64 row detector CT are substantial, and the benefits would outweigh increased cancer risks with decennial screening in the age group of 50-70 years.

  17. Lung cancer risk prediction to select smokers for screening CT--a model based on the Italian COSMOS trial.

    Science.gov (United States)

    Maisonneuve, Patrick; Bagnardi, Vincenzo; Bellomi, Massimo; Spaggiari, Lorenzo; Pelosi, Giuseppe; Rampinelli, Cristiano; Bertolotti, Raffaella; Rotmensz, Nicole; Field, John K; Decensi, Andrea; Veronesi, Giulia

    2011-11-01

    Screening with low-dose helical computed tomography (CT) has been shown to significantly reduce lung cancer mortality but the optimal target population and time interval to subsequent screening are yet to be defined. We developed two models to stratify individual smokers according to risk of developing lung cancer. We first used the number of lung cancers detected at baseline screening CT in the 5,203 asymptomatic participants of the COSMOS trial to recalibrate the Bach model, which we propose using to select smokers for screening. Next, we incorporated lung nodule characteristics and presence of emphysema identified at baseline CT into the Bach model and proposed the resulting multivariable model to predict lung cancer risk in screened smokers after baseline CT. Age and smoking exposure were the main determinants of lung cancer risk. The recalibrated Bach model accurately predicted lung cancers detected during the first year of screening. Presence of nonsolid nodules (RR = 10.1, 95% CI = 5.57-18.5), nodule size more than 8 mm (RR = 9.89, 95% CI = 5.84-16.8), and emphysema (RR = 2.36, 95% CI = 1.59-3.49) at baseline CT were all significant predictors of subsequent lung cancers. Incorporation of these variables into the Bach model increased the predictive value of the multivariable model (c-index = 0.759, internal validation). The recalibrated Bach model seems suitable for selecting the higher risk population for recruitment for large-scale CT screening. The Bach model incorporating CT findings at baseline screening could help defining the time interval to subsequent screening in individual participants. Further studies are necessary to validate these models.

  18. Network-based reading system for lung cancer screening CT

    Science.gov (United States)

    Fujino, Yuichi; Fujimura, Kaori; Nomura, Shin-ichiro; Kawashima, Harumi; Tsuchikawa, Megumu; Matsumoto, Toru; Nagao, Kei-ichi; Uruma, Takahiro; Yamamoto, Shinji; Takizawa, Hotaka; Kuroda, Chikazumi; Nakayama, Tomio

    2006-03-01

    This research aims to support chest computed tomography (CT) medical checkups to decrease the death rate by lung cancer. We have developed a remote cooperative reading system for lung cancer screening over the Internet, a secure transmission function, and a cooperative reading environment. It is called the Network-based Reading System. A telemedicine system involves many issues, such as network costs and data security if we use it over the Internet, which is an open network. In Japan, broadband access is widespread and its cost is the lowest in the world. We developed our system considering human machine interface and security. It consists of data entry terminals, a database server, a computer aided diagnosis (CAD) system, and some reading terminals. It uses a secure Digital Imaging and Communication in Medicine (DICOM) encrypting method and Public Key Infrastructure (PKI) based secure DICOM image data distribution. We carried out an experimental trial over the Japan Gigabit Network (JGN), which is the testbed for the Japanese next-generation network, and conducted verification experiments of secure screening image distribution, some kinds of data addition, and remote cooperative reading. We found that network bandwidth of about 1.5 Mbps enabled distribution of screening images and cooperative reading and that the encryption and image distribution methods we proposed were applicable to the encryption and distribution of general DICOM images via the Internet.

  19. CT study in tardive dyskinesia

    Energy Technology Data Exchange (ETDEWEB)

    Takamiya, M.; Tanoue, A.; Sakuma, K.; Itoh, H.; Nakazato, H.

    1987-03-01

    Fifteen schizophrenic patients having moderate tardive dyskinesia underwent computed tomography (CT). The CT findings were compared with those in the control nondyskinetic group matched for sex, age, clinical type, disease duration, length of antipychotropic treatment, and the total dosage. Regarding any of the variables studied, including area and density of the head of caudate nucleus and the lenticular nucleus, minimum distance between the bilateral caudate nuclei, maximum width of the third ventricle, and ventricle-brain ratio, there was no significant difference between the two groups. None of the variables were significantly different in the group with lobotomy (n = 5) and the group without it (n = 28). A review of the literature, in addition to these results, revealed that CT may be unhelpful in the detection of parenchymal changes in the brain, including the basal ganglia, contributing to the occurrence of tardive dyskinesia in patients with moderate symptoms.

  20. Korean Society of Thoracic Radiology Guideline for Lung Cancer Screening with Low-Dose CT

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Hyun Ju [Dept. of Radiology, Seoul National University Hospital, Seoul (Korea, Republic of); Kim, Jin Hwan [Dept. of Radiology, Chungnam National University Hospital, Chungnam National University School of Medicine, Daejeon (Korea, Republic of); Kim, Yoon Kyung [Dept. of Radiology, Gachon University Gil Medical Center, Incheon (Korea, Republic of); Park, Chang Min [Dept. of Radiology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of); Jeong, Yeon Joo [Dept. of Radiology, Pusan National University Hospital, Pusan National University School of Medicine and Medical Research Institute, Busan (Korea, Republic of)

    2012-09-15

    The National Lung Screening Trial (NLST), a nation-wide randomized controlled trial involving more than 50,000 current and former heavy smokers ages 55 to 74, compared the effects of two screening procedures (low-dose helical CT and standard chest radiography) on lung cancer mortality and found 20 percent fewer lung cancer deaths among trial participants screened with low-dose CT. Korean Society of Thoracic Radiology (KSTR) planned to establish an effective guideline for lung cancer screening with low-dose CT to improve health of Korean people and to reduce harms from misuse of lung cancer screening with low-dose CT. KSTR guideline for lung cancer screening with low-dose CT established based on objective medical evidences obtained by NLST.

  1. Does CT colonography have a role for population-based colorectal cancer screening?

    Energy Technology Data Exchange (ETDEWEB)

    Haan, Margriet C. de; Stoker, Jaap [Academic Medical Centre Amsterdam, Department of Radiology, G1-228, PO Box 22700, Amsterdam (Netherlands); Halligan, Steve [University College London, Centre for Medical Imaging, London (United Kingdom)

    2012-07-15

    Colorectal cancer (CRC) is the second most common cancer and second most common cause of cancer-related deaths in Europe. CRC screening has been proven to reduce disease-specific mortality and several European countries employ national screening programmes. These almost exclusively rely on stool tests, with endoscopy used as an adjunct in some countries. Computed tomographic colonography (CTC) is a potential screening test, with an estimated sensitivity of 88 % for advanced neoplasia {>=}10 mm. Recent randomised studies have shown that CTC and colonoscopy have similar yields of advanced neoplasia per screened invitee, indicating that CTC is potentially viable as a primary screening test. However, the evidence is not fully elaborated. It is unclear whether CTC screening is cost-effective and the impact of extracolonic findings, both medical and economic, remains unknown. Furthermore, the effect of CTC screening on CRC-related mortality is unknown, as it is also unknown for colonoscopy. It is plausible that both techniques could lead to decreased mortality, as for sigmoidoscopy and gFOBT. Although radiation exposure is a drawback, this disadvantage may be over-emphasised. In conclusion, the detection characteristics and acceptability of CTC suggest it is a viable screening investigation. Implementation will depend on detection of extracolonic disease and health-economic impact. Key Points circle Meta-analysis of CT colonographic screening showed high sensitivity for advanced neoplasia {>=}10mm. (orig.)

  2. Screening CT Colonography: Multicenter Survey of Patient Experience, Preference, and Potential Impact on Adherence

    Science.gov (United States)

    Pooler, B. Dustin; Baumel, Mark J.; Cash, Brooks D.; Moawad, Fouad J.; Riddle, Mark S.; Patrick, Amy M.; Damiano, Mark; Lee, Matthew H.; Kim, David H.; del Rio, Alejandro Muñoz; Pickhardt, Perry J.

    2013-01-01

    OBJECTIVE Prior research indicates CT colonography (CTC) would be a cost-effective colorectal cancer (CRC) screening test if widespread availability were to increase overall CRC screening adherence rates. The primary aims of this multicenter study were to evaluate patient experience and satisfaction with CTC screening and compare preference against screening colonoscopy. MATERIALS AND METHODS A 12-question survey instrument measuring pretest choice, experience, and satisfaction was given to a consecutive cohort of adults undergoing CTC screening in three disparate screening settings: university academic center, military medical center, and community practice. The study cohort was composed of individuals voluntarily participating in clinical CTC screening programs. RESULTS A total of 1417 patients responded to the survey. The top reasons for choosing CTC for screening included “noninvasiveness” (68.0%), “avoidance of sedation/anesthesia” (63.1%), “ability to drive after the test” (49.2%), “avoidance of optical colonoscopy risks” (46.9%), and “identifying abnormalities outside the colon” (43.3%). Only 7.2% of patients reported pain during the CTC examination and only 2.5% reported greater than moderate discomfort. Of 441 patients who had experienced both CTC and optical colonoscopy, 77.1% preferred CTC and 13.8% preferred optical colonoscopy. Of all patients, 29.6% indicated that they may not have undergone optical colonoscopy screening if CTC were not available. Of all patients, 92.9% labeled their overall experience with CTC as “excellent” or “good,” and 93.0% indicated they would choose CTC for their next screening. CONCLUSION Respondents reported a very high satisfaction level with CTC, and those who had experienced both modalities indicated a preference for CTC over optical colonoscopy. These results suggest that CTC has the potential to increase adherence to CRC screening guidelines if widely available. PMID:22623549

  3. From the present status of chest CT screening. The latest report from the laboratory using installation CT

    Energy Technology Data Exchange (ETDEWEB)

    Nakamura, Yoshimasa [Tokyo Health Service Association (Japan)

    1999-04-01

    The screening that used helical CT was enforced from 1997. Radiographical condition is as follows; voltage 120 kV, current 50 mA, beam width 10 mm, table speed 20 mm/sec/rot. Image data was reconstructed with 10 mm interval using 180 degree opposed beam interpolation. The detecting rate of lung cancer was 5.1% before transduction of CT, but 8.9% after transduction. The rate of stage 1 was 53.5% before transduction but 82.7% after transduction. Among 29 cases of lung cancer, 3 cases were detected with exfoliative cytology of sputum, and 26 cases by CT image. All of lung cancer diagnosed only with helical CT were in stage 1, and 16 cases were adenocarcinoma, and 2 cases were squamous cell carcinoma. Radius of cancer was an average of 30.4 mm before CT transduction, but 16.04 mm after the transduction. Radius of cancer which could be found by chest direct X-ray radiography was an average of 26.25 mm, and that which could be found out only with CT was an average of 11.5 mm. Cancer found by chest direct X-ray radiography was solid tumor, and contrast of image was high. There was also non-solid cancer whose image showed low contrast, in cancer discovered only with CT. In cost-benefit analysis, CT screening is more expensive but more beneficial than photofluoroscopic examination for lung cancer. (K.H.)

  4. Cost-effectiveness of the Introduction of Low-dose CT Screening in Japanese Smokers Aged 55 to 74 Years Old

    OpenAIRE

    Tabata, Hiroki; Akita, Tomoyuki; Matsuura, Akiko; Kaishima, Terumi; Matsuoka, Toshihiko; Ohisa, Masayuki; Awai, Kazuo; Tanaka, Junko

    2014-01-01

    The validity of low-dose CT screening for lung cancer in heavy smokers was supported by the results of National Lung Screening Trials (NLST) conducted in the U.S.A. The present study investigated the appropriateness of the introduction of low-dose CT screening for lung cancer in Japanese smokers aged between 55 and 74 years old, in terms of cost-effectiveness and age. To examine changes in the shift from conventional chest radiography (CR) to low-dose CT (LDCT) screening for lung cancer, we e...

  5. Positive predictive value for polyps detected at screening CT colonography

    Energy Technology Data Exchange (ETDEWEB)

    Pickhardt, Perry J.; Wise, Steven M.; Kim, David H. [University of Wisconsin School of Medicine and Public Health, Department of Radiology, Madison, WI (United States)

    2010-07-15

    To determine the positive predictive value (PPV) for polyps detected at CT colonography (CTC). Assessment of 739 colorectal lesions {>=}6 mm detected prospectively at CTC screening in 479 patients was performed. By-polyp PPV was analyzed according to small (6-9 mm) versus large ({>=}10 mm) size; morphology (sessile/pedunculated/flat); diagnostic confidence level (3 = most confident, 1 = least confident); and histology. By-patient PPV was analyzed at various polyp size thresholds. By-polyp PPV for CTC-detected lesions {>=}6 mm, 6-9 mm, and {>=}10 mm was 91.6% (677/739), 90.1% (410/451), and 92.7% (267/288), respectively (p = 0.4). By-polyp PPV according to sessile, pedunculated, flat, and mass-like morphology was 92.5% (441/477), 96.5% (139/144), 77.7% (73/94), and 97.6% (40/41), respectively (p < 0.0001 for flat versus polypoid morphology). By-polyp PPV according to diagnostic confidence level was 94.7% (554/585) for highest (= level 3), 83.5% (106/127) for intermediate (= level 2), and 63.0% (17/27) for lowest (= level 1) confidence (p < 0.0001 for levels-2/3 versus level-1). By-patient PPV at 6-mm, 8-mm, 10-mm, and 30-mm polyp size thresholds was 92.3% (442/479), 93.0% (306/329), 93.1% (228/245), and 97.4% (38/39), respectively. The overall per-polyp and per-patient PPV for lesions {>=}6 mm was 92% for CTC screening. Increased diagnostic confidence and polypoid (non-flat) morphology correlated with a higher PPV, whereas small versus large polyp size had very little effect. (orig.)

  6. WE-D-207-03: CT Protocols for Screening and the ACR Designated Lung Screening Program

    Energy Technology Data Exchange (ETDEWEB)

    McNitt-Gray, M. [UCLA School of Medicine (United States)

    2015-06-15

    In the United States, Lung Cancer is responsible for more cancer deaths than the next four cancers combined. In addition, the 5 year survival rate for lung cancer patients has not improved over the past 40 to 50 years. To combat this deadly disease, in 2002 the National Cancer Institute launched a very large Randomized Control Trial called the National Lung Screening Trial (NLST). This trial would randomize subjects who had substantial risk of lung cancer (due to age and smoking history) into either a Chest X-ray arm or a low dose CT arm. In November 2010, the National Cancer Institute announced that the NLST had demonstrated 20% fewer lung cancer deaths among those who were screened with low-dose CT than with chest X-ray. In December 2013, the US Preventive Services Task Force recommended the use of Lung Cancer Screening using low dose CT and a little over a year later (Feb. 2015), CMS announced that Medicare would also cover Lung Cancer Screening using low dose CT. Thus private and public insurers are required to provide Lung Cancer Screening programs using CT to the appropriate population(s). The purpose of this Symposium is to inform medical physicists and prepare them to support the implementation of Lung Screening programs. This Symposium will focus on the clinical aspects of lung cancer screening, requirements of a screening registry for systematically capturing and tracking screening patients and results (such as required Medicare data elements) as well as the role of the medical physicist in screening programs, including the development of low dose CT screening protocols. Learning Objectives: To understand the clinical basis and clinical components of a lung cancer screening program, including eligibility criteria and other requirements. To understand the data collection requirements, workflow, and informatics infrastructure needed to support the tracking and reporting components of a screening program. To understand the role of the medical physicist in

  7. CT-Screening for lung cancer does not increase the use of anxiolytic or antidepressant medication

    DEFF Research Database (Denmark)

    Kaerlev, Linda; Iachina, Maria; Pedersen, Jesper Holst

    2012-01-01

    CT screening for lung cancer has recently been shown to reduce lung cancer mortality, but screening may have adverse mental health effects. We calculated risk ratios for prescription of anti-depressive (AD) or anxiolytic (AX) medication redeemed at Danish pharmacies for participants in The Danish...... Lung Cancer Screening Trial (DLCST)....

  8. WE-B-207-02: CT Lung Cancer Screening and the Medical Physicist: A Dosimetry Summary of CT Participants in the National Lung Cancer Screening Trial (NLST)

    Energy Technology Data Exchange (ETDEWEB)

    Lee, C. [National Cancer Institute (United States)

    2015-06-15

    The US National Lung Screening Trial (NLST) was a multi-center randomized, controlled trial comparing a low-dose CT (LDCT) to posterior-anterior (PA) chest x-ray (CXR) in screening older, current and former heavy smokers for early detection of lung cancer. Recruitment was launched in September 2002 and ended in April 2004 when 53,454 participants had been randomized at 33 screening sites in equal proportions. Funded by the National Cancer Institute this trial demonstrated that LDCT screening reduced lung cancer mortality. The US Preventive Services Task Force (USPSTF) cited NLST findings and conclusions in its deliberations and analysis of lung cancer screening. Under the 2010 Patient Protection and Affordable Care Act, the USPSTF favorable recommendation regarding lung cancer CT screening assisted in obtaining third-party payers coverage for screening. The objective of this session is to provide an introduction to the NLST and the trial findings, in addition to a comprehensive review of the dosimetry investigations and assessments completed using individual NLST participant CT and CXR examinations. Session presentations will review and discuss the findings of two independent assessments, a CXR assessment and the findings of a CT investigation calculating individual organ dosimetry values. The CXR assessment reviewed a total of 73,733 chest x-ray exams that were performed on 92 chest imaging systems of which 66,157 participant examinations were used. The CT organ dosimetry investigation collected scan parameters from 23,773 CT examinations; a subset of the 75,133 CT examinations performed using 97 multi-detector CT scanners. Organ dose conversion coefficients were calculated using a Monte Carlo code. An experimentally-validated CT scanner simulation was coupled with 193 adult hybrid computational phantoms representing the height and weight of the current U.S. population. The dose to selected organs was calculated using the organ dose library and the abstracted scan

  9. Detection of lung cancer through low-dose CT screening (NELSON) : a prespecifi ed analysis of screening test performance and interval cancers

    NARCIS (Netherlands)

    Horeweg, Nanda; Scholten, Ernst Th; de Jong, Pim A.; van der Aalst, Carlijn M.; Weenink, Carla; Lammers, Jan-Willem J.; Nackaerts, Kristiaan; Vliegenthart, Rozemarijn; ten Haaf, Kevin; Yousaf-Khan, Uraujh A.; Heuvelmans, Marjolein A.; Thunnissen, Erik; Oudkerk, Matthijs; Mali, Willem; de Koning, Harry J.

    2014-01-01

    Background Low-dose CT screening is recommended for individuals at high risk of developing lung cancer. However, CT screening does not detect all lung cancers: some might be missed at screening, and others can develop in the interval between screens. The NELSON trial is a randomised trial to assess

  10. Lung cancer incidence and mortality in National Lung Screening Trial participants who underwent low-dose CT prevalence screening: a retrospective cohort analysis of a randomised, multicentre, diagnostic screening trial

    Science.gov (United States)

    Patz, Edward F; Greco, Erin; Gatsonis, Constantine; Pinsky, Paul; Kramer, Barnett S; Aberle, Denise R

    2016-01-01

    Summary Background Annual low-dose CT screening for lung cancer has been recommended for high-risk individuals, but the necessity of yearly low-dose CT in all eligible individuals is uncertain. This study examined rates of lung cancer in National Lung Screening Trial (NLST) participants who had a negative prevalence (initial) low-dose CT screen to explore whether less frequent screening could be justified in some lower-risk subpopulations. Methods We did a retrospective cohort analysis of data from the NLST, a randomised, multicentre screening trial comparing three annual low-dose CT assessments with three annual chest radiographs for the early detection of lung cancer in high-risk, eligible individuals (aged 55–74 years with at least a 30 pack-year history of cigarette smoking, and, if a former smoker, had quit within the past 15 years), recruited from US medical centres between Aug 5, 2002, and April 26, 2004. Participants were followed up for up to 5 years after their last annual screen. For the purposes of this analysis, our cohort consisted of all NLST participants who had received a low-dose CT prevalence (T0) screen. We determined the frequency, stage, histology, study year of diagnosis, and incidence of lung cancer, as well as overall and lung cancer-specific mortality, and whether lung cancers were detected as a result of screening or within 1 year of a negative screen. We also estimated the effect on mortality if the first annual (T1) screen in participants with a negative T0 screen had not been done. The NLST is registered with ClinicalTrials.gov, number NCT00047385. Findings Our cohort consisted of 26 231 participants assigned to the low-dose CT screening group who had undergone their T0 screen. The 19 066 participants with a negative T0 screen had a lower incidence of lung cancer than did all 26 231 T0-screened participants (371·88 [95% CI 337·97–408·26] per 100 000 person-years vs 661·23 [622·07–702·21]) and had lower lung cancer

  11. Screening for lung cancer with low-dose computed tomography; Bronchialkarzinom-Screening mit Niedrigdosis-CT. Aktueller Stand

    Energy Technology Data Exchange (ETDEWEB)

    Diederich, S.; Wormanns, D.; Heindel, W. [Muenster Univ. (Germany). Inst. fuer Klinische Radiologie

    2001-03-01

    Lung cancer is the most common cause of death from malignancy. It is characterized by a favourable prognosis when treated in early stages and a poor prognosis in advanced stages. Populations at risk are relatively well defined, i.e. heavy smokers and workers exposed to asbestos and radon. Therefore, early detection using diagnostic techniques promises reduction of mortality from this tumor. Previous studies using chest radiography and sputum cytology were, however, disappointing due to poor sensitivity of these tests for early tumor stages. The new technique of low-dose computed tomography provides both high sensitivity for small tumors and a comfortable examination. As small benign pulmonary nodules are common reliable non-invasive diagnostic algorithms are required for classification of nodules. Preliminary studies using low-dose CT screening in smokers have provided promising results. Prior to a wide application of the technique in clinical routine more data are required as to inclusion criteria, examination intervals and the effect of screening on mortality reduction. (orig.) [German] Das Bronchialkarzinom ist der am haeufigsten zum Tode fuehrende maligne Tumor. Seine Prognose ist bei einer Therapie in fruehen Stadien relativ gut, in fortgeschrittenen Erkrankungsstadien dagegen ausgesprochen schlecht. Die Risikopopulationen sind gut charakterisiert, v.a. starke Raucher und Personen mit einer beruflichen Asbest- bzw. Radonexposition. Vor diesem Hintergrund erscheinen Frueherkennungsuntersuchungen mittels diagnostischer Verfahren sinnvoll, um die Sterblichkeit an diesem Tumor zu senken. Bisherige Erfahrungen mit Thoraxroentgenaufnahmen und Sputumuntersuchungen waren aufgrund der geringen Sensitivitaet der Verfahren fuer fruehe Tumorstadien jedoch enttaeuschend. Das relativ neue Verfahren der Niedrigdosis-Computertomographie des Thorax verbindet eine hohe Sensitivitaet fuer kleine Tumoren mit einer geringen Belastung der untersuchten Person. Wegen der Haeufigkeit

  12. Blinded Validation of Breath Biomarkers of Lung Cancer, a Potential Ancillary to Chest CT Screening.

    Directory of Open Access Journals (Sweden)

    Michael Phillips

    , in a blinded replicated study. Combining breath biomarkers with chest CT could potentially improve the sensitivity and specificity of lung cancer screening.ClinicalTrials.gov NCT00639067.

  13. Smoking habits in the randomised Danish Lung Cancer Screening Trial with low-dose CT

    DEFF Research Database (Denmark)

    Ashraf, Haseem; Saghir, Zaigham; Dirksen, Asger

    2014-01-01

    to annual low-dose CT (CT group) and 2052 received no intervention (control group). Participants were current and ex-smokers (≥4 weeks abstinence from smoking) with a tobacco consumption of ≥20 pack years. Smoking habits were determined annually. Missing values for smoking status at the final screening...

  14. Coronary calcium screening with dual-source CT: reliability of ungated, high-pitch chest CT in comparison with dedicated calcium-scoring CT

    Energy Technology Data Exchange (ETDEWEB)

    Hutt, Antoine; Faivre, Jean-Baptiste; Remy, Jacques; Remy-Jardin, Martine [CHRU et Universite de Lille, Department of Thoracic Imaging, Hospital Calmette (EA 2694), Lille (France); Duhamel, Alain; Deken, Valerie [CHRU et Universite de Lille, Department of Biostatistics (EA 2694), Lille (France); Molinari, Francesco [Centre Hospitalier General de Tourcoing, Department of Radiology, Tourcoing (France)

    2016-06-15

    To investigate the reliability of ungated, high-pitch dual-source CT for coronary artery calcium (CAC) screening. One hundred and eighty-five smokers underwent a dual-source CT examination with acquisition of two sets of images during the same session: (a) ungated, high-pitch and high-temporal resolution acquisition over the entire thorax (i.e., chest CT); (b) prospectively ECG-triggered acquisition over the cardiac cavities (i.e., cardiac CT). Sensitivity and specificity of chest CT for detecting positive CAC scores were 96.4 % and 100 %, respectively. There was excellent inter-technique agreement for determining the quantitative CAC score (ICC = 0.986). The mean difference between the two techniques was 11.27, representing 1.81 % of the average of the two techniques. The inter-technique agreement for categorizing patients into the four ranks of severity was excellent (weighted kappa = 0.95; 95 % CI 0.93-0.98). The inter-technique differences for quantitative CAC scores did not correlate with BMI (r = 0.05, p = 0.575) or heart rate (r = -0.06, p = 0.95); 87.2 % of them were explained by differences at the level of the right coronary artery (RCA: 0.8718; LAD: 0.1008; LCx: 0.0139; LM: 0.0136). Ungated, high-pitch dual-source CT is a reliable imaging mode for CAC screening in the conditions of routine chest CT examinations. (orig.)

  15. Indications for and results of CT colonography: from screening to the symptomatic patient; Indikationen und Ergebnisse der CT-Kolonographie: von der Vorsorge bis zum symptomatischen Patienten

    Energy Technology Data Exchange (ETDEWEB)

    Graser, A.; Becker, C.R.; Reiser, M.F. [Klinikum Grosshadern der LMU Muenchen, Institut fuer Klinische Radiologie, Muenchen (Germany); Mang, T. [Medizinische Universitaet Wien, Universitaetsklinik fuer Radiodiagnostik, AKH Wien, Wien (Austria)

    2008-02-15

    CT colonography (CTC) is also referred to as virtual colonoscopy and is being used with increasing frequency in radiological practice. While there are still no generally accepted, clear-cut indications for its use in mass colorectal cancer screening, there is evidence that this investigation is useful in patients in whom colonoscopy has not been successful or who have known stenotic lesions in the colon. Recent results of significant comparative studies of CTC and conventional colonoscopy will have some influence on the future place of CTC in screening for cancer of the bowel; they show the great potential of CT-aided bowel examination. (orig.) [German] Die CT-Kolonographie (CTK), auch als virtuelle Koloskopie bezeichnet, wird zunehmend in der radiologischen Praxis eingesetzt. Waehrend fuer die reine Vorsorgeuntersuchung z. Z. noch keine rechtfertigende Indikation besteht, koennen symptomatische Patienten nach fehlgeschlagener Koloskopie oder zur Beurteilung des Darms proximal einer Stenose mittels CTK untersucht werden. Ergebnisse wichtiger Studien, die die CT-Kolonographie mit der herkoemmlichen Koloskopie vergleichen, beeinflussen die zukuenftige Position der Untersuchungsmethode beim Darmkrebsscreening. Vergleichsstudien mit der Koloskopie zeigen das grosse Potenzial der CT-gestuetzten Darmuntersuchung. (orig.)

  16. Screening for lungecancer med lavdosis-CT kræver grundige overvejelser

    DEFF Research Database (Denmark)

    Saghir, Z.; Dirksen, A.; Ashraf, H.;

    2015-01-01

    Results from the American National Lung Screening Trial (NLST) show a significant reduction in lung cancer and all-cause mortality in a high risk population screened with annual low-dose CT. Handling of pulmonary nodules, false positive tests, overdiagnosis, psychosocial consequences and cost-eff......-efficiency etc. are all aspects that require careful consideration. This paper gives an overview of the current knowledge on these issues. Before a recommendation can be made, we need an overall evaluation of both the benefits and harms in CT screening for lung cancer.......Results from the American National Lung Screening Trial (NLST) show a significant reduction in lung cancer and all-cause mortality in a high risk population screened with annual low-dose CT. Handling of pulmonary nodules, false positive tests, overdiagnosis, psychosocial consequences and cost...

  17. Early Identification of Small Airways Disease on Lung Cancer Screening CT: Comparison of Current Air Trapping Measures

    NARCIS (Netherlands)

    Mets, O.M.; Zanen, P.; Lammers, J.-W.J.; Isgum, I.; Gietema, H.A.; Ginneken, B. van; Prokop, M.; Jong, P. A. de

    2012-01-01

    BACKGROUND : Lung cancer screening CT scans might provide valuable information about air trapping as an early indicator of smoking-related lung disease. We studied which of the currently suggested measures is most suitable for detecting functionally relevant air trapping on low-dose computed tomogra

  18. WE-D-207-00: CT Lung Cancer Screening and the Medical Physicist: Moving Forward

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2015-06-15

    In the United States, Lung Cancer is responsible for more cancer deaths than the next four cancers combined. In addition, the 5 year survival rate for lung cancer patients has not improved over the past 40 to 50 years. To combat this deadly disease, in 2002 the National Cancer Institute launched a very large Randomized Control Trial called the National Lung Screening Trial (NLST). This trial would randomize subjects who had substantial risk of lung cancer (due to age and smoking history) into either a Chest X-ray arm or a low dose CT arm. In November 2010, the National Cancer Institute announced that the NLST had demonstrated 20% fewer lung cancer deaths among those who were screened with low-dose CT than with chest X-ray. In December 2013, the US Preventive Services Task Force recommended the use of Lung Cancer Screening using low dose CT and a little over a year later (Feb. 2015), CMS announced that Medicare would also cover Lung Cancer Screening using low dose CT. Thus private and public insurers are required to provide Lung Cancer Screening programs using CT to the appropriate population(s). The purpose of this Symposium is to inform medical physicists and prepare them to support the implementation of Lung Screening programs. This Symposium will focus on the clinical aspects of lung cancer screening, requirements of a screening registry for systematically capturing and tracking screening patients and results (such as required Medicare data elements) as well as the role of the medical physicist in screening programs, including the development of low dose CT screening protocols. Learning Objectives: To understand the clinical basis and clinical components of a lung cancer screening program, including eligibility criteria and other requirements. To understand the data collection requirements, workflow, and informatics infrastructure needed to support the tracking and reporting components of a screening program. To understand the role of the medical physicist in

  19. A practical approach to radiological evaluation of CT lung cancer screening examinations

    NARCIS (Netherlands)

    Xie, Xueqian; Heuvelmans, Marjolein A.; van Ooijen, Peter M. A.; Oudkerk, Matthijs; Vliegenthart, Rozemarijn

    2013-01-01

    Lung cancer is the most common cause of cancer-related death in the world. The Dutch-Belgian Randomized Lung Cancer Screening Trial (Dutch acronym: NELSON) was launched to investigate whether screening for lung cancer by low-dose multidetector computed tomography (CT) in high-risk patients will lead

  20. A practical approach to radiological evaluation of CT lung cancer screening examinations

    NARCIS (Netherlands)

    Xie, Xueqian; Heuvelmans, Marjolein A.; van Ooijen, Peter M. A.; Oudkerk, Matthijs; Vliegenthart, Rozemarijn

    2013-01-01

    Lung cancer is the most common cause of cancer-related death in the world. The Dutch-Belgian Randomized Lung Cancer Screening Trial (Dutch acronym: NELSON) was launched to investigate whether screening for lung cancer by low-dose multidetector computed tomography (CT) in high-risk patients will lead

  1. Nutrient intake and nutrient patterns and risk of lung cancer among heavy smokers: results from the COSMOS screening study with annual low-dose CT.

    Science.gov (United States)

    Gnagnarella, Patrizia; Maisonneuve, Patrick; Bellomi, Massimo; Rampinelli, Cristiano; Bertolotti, Raffaella; Spaggiari, Lorenzo; Palli, Domenico; Veronesi, Giulia

    2013-06-01

    The role of nutrients in lung cancer aetiology remains controversial and has never been evaluated in the context of screening. Our aim was to investigate the role of single nutrients and nutrient patterns in the aetiology of lung cancer in heavy smokers. Asymptomatic heavy smokers (≥20 pack-years) were invited to undergo annual low-dose computed tomography. We assessed diet using a self-administered food frequency questionnaire and collected information on multivitamin supplement use. We performed principal component analysis identifying four nutrient patterns and used Cox proportional Hazards regression to assess the association between nutrients and nutrients patterns and lung cancer risk. During a mean follow-up of 5.7 years, 178 of 4,336 participants were diagnosed with lung cancer by screening. We found a significant risk reduction of lung cancer with increasing vegetable fat consumption (HR for highest vs. lowest quartile = 0.50, 95% CI = 0.31-0.80; P-trend = 0.02). Participants classified in the high "vitamins and fiber" pattern score had a significant risk reduction of lung cancer (HR = 0.57; 95% CI = 0.36-0.90, P-trend = 0.01). Among heavy smokers enrolled in a screening trial, high vegetable fat intake and adherence to the "vitamin and fiber" nutrient pattern were associated with reduced lung cancer incidence.

  2. Panel Reviews Benefits and Harms of CT Scans for Lung Cancer Screening | Division of Cancer Prevention

    Science.gov (United States)

    A panel of experts has reviewed the evidence regarding the benefits and harms of screening for lung cancer with low-dose computed tomography (CT) and concluded that the technology may benefit some individuals at high risk for lung cancer. But the panel cautioned that many questions remain about the potential harms of screening and how to translate screening into clinical practice. |

  3. WE-B-207-00: CT Lung Cancer Screening Part 1

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2015-06-15

    The US National Lung Screening Trial (NLST) was a multi-center randomized, controlled trial comparing a low-dose CT (LDCT) to posterior-anterior (PA) chest x-ray (CXR) in screening older, current and former heavy smokers for early detection of lung cancer. Recruitment was launched in September 2002 and ended in April 2004 when 53,454 participants had been randomized at 33 screening sites in equal proportions. Funded by the National Cancer Institute this trial demonstrated that LDCT screening reduced lung cancer mortality. The US Preventive Services Task Force (USPSTF) cited NLST findings and conclusions in its deliberations and analysis of lung cancer screening. Under the 2010 Patient Protection and Affordable Care Act, the USPSTF favorable recommendation regarding lung cancer CT screening assisted in obtaining third-party payers coverage for screening. The objective of this session is to provide an introduction to the NLST and the trial findings, in addition to a comprehensive review of the dosimetry investigations and assessments completed using individual NLST participant CT and CXR examinations. Session presentations will review and discuss the findings of two independent assessments, a CXR assessment and the findings of a CT investigation calculating individual organ dosimetry values. The CXR assessment reviewed a total of 73,733 chest x-ray exams that were performed on 92 chest imaging systems of which 66,157 participant examinations were used. The CT organ dosimetry investigation collected scan parameters from 23,773 CT examinations; a subset of the 75,133 CT examinations performed using 97 multi-detector CT scanners. Organ dose conversion coefficients were calculated using a Monte Carlo code. An experimentally-validated CT scanner simulation was coupled with 193 adult hybrid computational phantoms representing the height and weight of the current U.S. population. The dose to selected organs was calculated using the organ dose library and the abstracted scan

  4. Colorectal cancer screening:The role of CT colonography

    Institute of Scientific and Technical Information of China (English)

    Andrea; Laghi; Franco; Iafrate; Marco; Rengo; Cesare; Hassan

    2010-01-01

    Computed tomography colonography(CTC) in colorectal cancer(CRC) screening has two roles:one present and the other potential.The present role is,without any further discussion,the integration into established screening programs as a replacement for barium enema in the case of incomplete colonoscopy.The potential role is the use of CTC as a first-line screening method together with Fecal Occult Blood Test,sigmoidoscopy and colonoscopy.However,despite the fact that CTC has been officially endorsed for CRC scre...

  5. Cine CT technique for dynamic airway studies

    Energy Technology Data Exchange (ETDEWEB)

    Ell, S.R.; Jolles, H.; Keyes, W.D.; Galvin, J.R.

    1985-07-01

    The advent of cine CT scanning with its 50-msec data acquisition time promises a much wider range of dynamic CT studies. The authors describe a method for dynamic evaluation of the extrathoracic airway, which they believe has considerable potential application in nonfixed upper-airway disease, such as sleep apnea and stridor of unknown cause. Conventional CT is limited in such studies by long data acquisition time and can be used to study only prolonged maneuvers such as phonation. Fluoroscopy and digital subtraction studies are limited by relatively high radiation dose and inability to image all wall motions simultaneously.

  6. Elevated serum CA 19-9 at screening tests: underlying conditions and role of abdominopelvic CT

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Ji Yang [University of Louisville, Department of Radiology and Molecular Imaging Research Center, Louisville, KY (United States); Seoul National University Hospital, Department of Radiology, Healthcare System Gangnam Center, Seoul (Korea, Republic of); Kim, Se Hyung [Seoul National University Hospital, Department of Radiology and the Institute of Radiation Medicine, Seoul (Korea, Republic of); Kim, Soo Young [Seoul National University Hospital, Department of Radiology, Healthcare System Gangnam Center, Seoul (Korea, Republic of); Bundang CHA Hospital, Department of Radiology, Bundang (Korea, Republic of)

    2014-10-15

    To investigate underlying conditions of patients with elevated CA 19-9 at screening tests and to evaluate diagnostic performance of abdominopelvic CT. One hundred and thirteen patients with elevated CA 19-9 (>37 U/ml) who underwent abdominopelvic CT in a screening program were selected. Underlying conditions were determined by reviewing all available data and follow-up records. Patients were categorized into malignancy, benign, and normal/non-related disease groups. Their mean CA 19-9 and percent of patients with CA 19-9 ≥ 100 U/ml were compared. Diagnostic sensitivity of CT for detecting underlying conditions of elevated CA 19-9 was analysed. Seventeen patients (17/113, 15 %) had 17 elevated CA 19-9-related malignancies, and 55 patients (55/113, 48.7 %) had 70 benign diseases. Mean CA 19-9 and percent of patients with CA 19-9 ≥ 100 U/ml in the malignancy group were significantly higher than in the two other groups. CT detected all except one malignant lesion with a detection sensitivity of 94.1 % (16/17). Of 70 CA 19-9-related benign diseases, CT detected 34 benign diseases (48.6 %) providing an alternative diagnosis for elevated CA 19-9. Abdominopelvic CT is not only useful in detecting malignancies, but can also diagnose alternative benign causes of elevated CA 19-9 in asymptomatic screening tests. (orig.)

  7. CT Lung Cancer Screening Program Development: Part 2.

    Science.gov (United States)

    Yates, Teri

    2015-01-01

    Radiology administrators must use innovative strategies around clinical collaboration and marketing to ensure that patients access the service in sufficient numbers. Radiology Associates of South Florida in collaboration with Baptist Health South Florida have developed a successful lung cancer screening program. The biggest factors in their success have been the affordability of their service and the quality of the program. Like mammography, lung cancer screening programs serve as an entry point to other services that generate revenue for the hospital. Patients may require further evaluation in the form of more imaging or surgical services for biopsy. Part 1 provided background and laid out fundamentals for starting a program. Part 2 focuses on building patient volume, marketing, and issues related to patient management after the screen is performed.

  8. Management of subsolid pulmonary nodules in CT lung cancer screening

    NARCIS (Netherlands)

    Heuvelmans, Marjolein A.; Oudkerk, Matthijs

    2015-01-01

    The distinct appearance and behavior of subsolid pulmonary nodules (SSNs) has resulted in separate recommendations for the management of solitary SSNs, both for incidentally detected as well as for screen detected nodules. However, these guidelines have been based primarily on expert opinion. Recent

  9. Management of subsolid pulmonary nodules in CT lung cancer screening

    NARCIS (Netherlands)

    Heuvelmans, Marjolein A.; Oudkerk, Matthijs

    The distinct appearance and behavior of subsolid pulmonary nodules (SSNs) has resulted in separate recommendations for the management of solitary SSNs, both for incidentally detected as well as for screen detected nodules. However, these guidelines have been based primarily on expert opinion.

  10. CT scan screening for lung cancer: risk factors for nodules and malignancy in a high-risk urban cohort.

    Directory of Open Access Journals (Sweden)

    Alissa K Greenberg

    Full Text Available BACKGROUND: Low-dose computed tomography (CT for lung cancer screening can reduce lung cancer mortality. The National Lung Screening Trial reported a 20% reduction in lung cancer mortality in high-risk smokers. However, CT scanning is extremely sensitive and detects non-calcified nodules (NCNs in 24-50% of subjects, suggesting an unacceptably high false-positive rate. We hypothesized that by reviewing demographic, clinical and nodule characteristics, we could identify risk factors associated with the presence of nodules on screening CT, and with the probability that a NCN was malignant. METHODS: We performed a longitudinal lung cancer biomarker discovery trial (NYU LCBC that included low-dose CT-screening of high-risk individuals over 50 years of age, with more than 20 pack-year smoking histories, living in an urban setting, and with a potential for asbestos exposure. We used case-control studies to identify risk factors associated with the presence of nodules (n=625 versus no nodules (n=557, and lung cancer patients (n=30 versus benign nodules (n=128. RESULTS: The NYU LCBC followed 1182 study subjects prospectively over a 10-year period. We found 52% to have NCNs >4 mm on their baseline screen. Most of the nodules were stable, and 9.7% of solid and 26.2% of sub-solid nodules resolved. We diagnosed 30 lung cancers, 26 stage I. Three patients had synchronous primary lung cancers or multifocal disease. Thus, there were 33 lung cancers: 10 incident, and 23 prevalent. A sub-group of the prevalent group were stable for a prolonged period prior to diagnosis. These were all stage I at diagnosis and 12/13 were adenocarcinomas. CONCLUSIONS: NCNs are common among CT-screened high-risk subjects and can often be managed conservatively. Risk factors for malignancy included increasing age, size and number of nodules, reduced FEV1 and FVC, and increased pack-years smoking. A sub-group of screen-detected cancers are slow-growing and may contribute to over

  11. Diagnostic value of CT-colonography as compared to colonoscopy in an asymptomatic screening population: a meta-analysis

    Energy Technology Data Exchange (ETDEWEB)

    Haan, Margriet C. de [University of Amsterdam, Department of Radiology, Academic Medical Center, Amsterdam (Netherlands); Academic Medical Center, Amsterdam, Department of Radiology, G1-223.1, Amsterdam (Netherlands); Gelder, Rogier E. van; Bipat, Shandra; Stoker, Jaap [University of Amsterdam, Department of Radiology, Academic Medical Center, Amsterdam (Netherlands); Graser, Anno [University of Munich, Department of Clinical Radiology, Klinikum Grosshadern, Munich (Germany)

    2011-08-15

    Previous meta-analyses on CT-colonography included both average and high risk individuals, which may overestimate the diagnostic value in screening. A meta-analysis was performed to obtain the value of CT-colonography for screening. A search was performed using PubMed, Embase and Cochrane. Article selection and critical appraisal was done by two reviewers. Inclusion criteria: prospective, randomized trials or cohort studies comparing CT-colonography with colonoscopy ({>=}50 participants), {>=}95% average risk participants {>=}50 years. Study characteristics and 2 x 2 contingency Tables were recorded. Sensitivity and specificity estimates were calculated per patient and per polyp ({>=}6 mm, {>=}10 mm), using univariate and bivariate analyses. Five of 1,021 studies identified were included, including 4,086 participants (<1% high risk). I{sup 2}-values showed substantial heterogeneity, especially for 6-9 mm polyps and adenomas: 68.1% vs. 78.6% (sensitivity per patient). Estimated sensitivities for patients with polyps or adenomas {>=} 6 mm were 75.9% and 82.9%, corresponding specificities 94.6% and 91.4%. Estimated sensitivities for patients with polyps or adenomas {>=} 10 mm were 83.3% and 87.9%, corresponding specificities 98.7% and 97.6%. Estimated sensitivities per polyp for advanced adenomas {>=} 6 mm and {>=} 10 mm were 83.9% and 83.8%. Compared to colonoscopy, CT-colonography has a high sensitivity for adenomas {>=} 10 mm. For (advanced) adenomas {>=} 6 mm sensitivity is somewhat lower. (orig.)

  12. Lung cancer screening with low-dose helical CT in Korea: experiences at the Samsung Medical Center.

    Science.gov (United States)

    Chong, Semin; Lee, Kyung Soo; Chung, Myung Jin; Kim, Tae Sung; Kim, Hojoong; Kwon, O Jung; Choi, Yoon-Ho; Rhee, Chong H

    2005-06-01

    To determine overall detection rates of lung cancer by low-dose CT (LDCT) screening and to compare histopathologic and imaging differences of detected cancers between high- and low-risk groups, this study included 6,406 asymptomatic Korean adults with >or=45 yr of age who underwent LDCT for lung cancer screening. All were classified into high- (>or=20 pack-year smoking; 3,353) and low-risk (3,053; <20 pack-yr smoking and non-smokers) groups. We compared CT findings of detected cancers and detection rates between high- and low-risk. At initial CT, 35% (2,255 of 6,406) had at least one or more non-calcified nodule. Lung cancer detection rates were 0.36% (23 of 6,406). Twenty-one non-small cell lung cancers appeared as solid (n=14) or ground-glass opacity (GGO) (n=7) nodules. Cancer likelihood was higher in GGO nodules than in solid nodules (p<0.01). Fifteen of 23 cancers occurred in high-risk group and 8 in low-risk group (p=0.215). Therefore, LDCT screening help detect early stage of lung cancer in asymptomatic Korean population with detection rate of 0.36% on a population basis and may be useful for discovering early lung cancer in low-risk group as well as in high-risk group.

  13. PROSPECTIVE STUDY OF CT IN ACUTE PANCREATITIS AND ITS COMPLICATIONS

    Directory of Open Access Journals (Sweden)

    Shivanand S .

    2015-09-01

    Full Text Available Visualization of the pancreas was far better by CT than b y ultrasound. Ultrasound had certain limitation. Due to bowel gas the pancreas may not be visualized. Extra pancreatic spread of inflammation and vascular complications was not always picked up by Ultrasonography. These limitations were overcome with the u se of CT which yielded more diagnostic information in the evaluation of acute pancreatitis. CT is a confirmative investigation in diagnosis and staging of acute pancreatitis. MCTSI is a very useful tool for the screening of patients with acute pancreatitis for the classification of severity accurately and to predict the clinical outcome. OBJECTIVES OF STUDY: To determine the value of computed tomography in evaluation of early diagnosis of acute pancreatitis. To evaluate the complications using computed tom ography severity index. MATERIAL AND METHODS: The study was conducted on 100 patients with clinical suspicion of acute pancreatitis, altered biochemical parameters (Serum amylase, Serum lipase in favor of acute pancreatitis, ultrasonography suggestive of acute pancreatitis and complications known case of chronic pancreatitis with features of acute symptoms who were referred to the department of Radiodiagnosis, Basaveshwar teaching & General Hospital, Kalaburagi. Before evaluating a patient by CT imaging, i nformed consent was obtained from the patient or guardian. The patient were informed about the radiation exposure in the examination. CT was carried out using Philips 6 slice scanner. Scan was obtained with both plain and contrast study. RESULT: 100 patien ts were included in the study. 83% patients were males and 17% patients were females. Majority of patients belonged to 31 - 40 yrs. of age group. Alcohol was the most common cause of acute pancreatitis. 73 patients had positive ultrasound finding while CT wa s positive in all cases. According to, MCTSI 63 patients had moderate, 26 patients had mild and 11 patients had severe

  14. Screening for Ischemic Heart Disease with Cardiac CT: Current Recommendations

    Directory of Open Access Journals (Sweden)

    Matthew J. Budoff

    2012-01-01

    Full Text Available Cardiovascular disease remains the leading cause of mortality in the US and worldwide, and no widespread screening for this number one killer has been implemented. Traditional risk factor assessment does not fully account for the coronary risk and underestimates the prediction of risk even in patients with established risk factors for atherosclerosis. Coronary artery calcium (CAC represents calcified atherosclerosis in the coronary arteries. It has been shown to be the strongest predictor of adverse future cardiovascular events and provides incremental information to the traditional risk factors. CAC consistently outperforms traditional risk factors, including models such as Framingham risk to predict future CV events. It has been incorporated into both the European and American guidelines for risk assessment. CAC is the most robust test today to reclassify individuals based on traditional risk factor assessment and provides the opportunity to better strategize the treatments for these subjects (converting patients from intermediate to high or low risk. CAC progression has also been identified as a risk for future cardiovascular events, with markedly increased events occurring in those patients exhibiting increases in calcifications over time. The exact intervals for rescanning is still being evaluated.

  15. SU-E-I-34: Evaluating Use of AEC to Lower Dose for Lung Cancer Screening CT Protocols

    Energy Technology Data Exchange (ETDEWEB)

    Arbique, G; Anderson, J [UT Southwestern Medical Ctr at Dallas, Dallas, TX (United States); Guild, J; Duan, X [UT Southwestern Medical Center, Dallas, TX (United States); Malguria, N; Omar, H; Brewington, C [Ut Southwestern, Dallas, TX (United States); Zhang, D [Toshiba America Medical Systems, Tustin, CA (United States)

    2015-06-15

    Purpose: The National Lung Screening Trial mandated manual low dose CT technique factors, where up to a doubling of radiation output could be used over a regular to large patient size range. Recent guidance from the AAPM and ACR for lung cancer CT screening recommends radiation output adjustment for patient size either through AEC or a manual technique chart. This study evaluated the use of AEC for output control and dose reduction. Methods: The study was performed on a multidetector helical CT scanner (Aquillion ONE, Toshiba Medical) equipped with iterative reconstruction (ADIR-3D), AEC was adjusted with a standard deviation (SD) image quality noise index. The protocol SD parameter was incrementally increased to reduce patient population dose while image quality was evaluated by radiologist readers scoring the clinical utility of images on a Likert scale. Results: Plots of effective dose vs. body size (water cylinder diameter reported by the scanner) demonstrate monotonic increase in patient dose with increasing patient size. At the initial SD setting of 19 the average CTDIvol for a standard size patient was ∼ 2.0 mGy (1.2 mSv effective dose). This was reduced to ∼1.0 mGy (0.5 mSv) at an SD of 25 with no noticeable reduction in clinical utility of images as demonstrated by Likert scoring. Plots of effective patient diameter and BMI vs body size indicate that these metrics could also be used for manual technique charts. Conclusion: AEC offered consistent and reliable control of radiation output in this study. Dose for a standard size patient was reduced to one-third of the 3 mGy CTDIvol limit required for ACR accreditation of lung cancer CT screening. Gary Arbique: Research Grant, Toshiba America Medical Systems; Cecelia Brewington: Research Grant, Toshiba America Medical Systems; Di Zhang: Employee, Toshiba America Medical Systems.

  16. Cost analysis of colorectal cancer screening with CT colonography in Italy.

    Science.gov (United States)

    Mantellini, Paola; Lippi, Giuseppe; Sali, Lapo; Grazzini, Grazia; Delsanto, Silvia; Mallardi, Beatrice; Falchini, Massimo; Castiglione, Guido; Carozzi, Francesca Maria; Mascalchi, Mario; Milani, Stefano; Ventura, Leonardo; Zappa, Marco

    2017-07-05

    Unit costs of screening CT colonography (CTC) can be useful for cost-effectiveness analyses and for health care decision-making. We evaluated the unit costs of CTC as a primary screening test for colorectal cancer in the setting of a randomized trial in Italy. Data were collected within the randomized SAVE trial. Subjects were invited to screening CTC by mail and requested to have a pre-examination consultation. CTCs were performed with 64- and 128-slice CT scanners after reduced or full bowel preparation. Activity-based costing was used to determine unit costs per-process, per-participant to screening CTC, and per-subject with advanced neoplasia. Among 5242 subjects invited to undergo screening CTC, 1312 had pre-examination consultation and 1286 ultimately underwent CTC. Among 129 subjects with a positive CTC, 126 underwent assessment colonoscopy and 67 were ultimately diagnosed with advanced neoplasia (i.e., cancer or advanced adenoma). Cost per-participant of the entire screening CTC pathway was €196.80. Average cost per-participant for the screening invitation process was €17.04 and €9.45 for the pre-examination consultation process. Average cost per-participant of the CTC execution and reading process was €146.08 and of the diagnostic assessment colonoscopy process was €24.23. Average cost per-subject with advanced neoplasia was €3777.30. Cost of screening CTC was €196.80 per-participant. Our data suggest that the more relevant cost of screening CTC, amenable of intervention, is related to CTC execution and reading process.

  17. Teleradiology based CT colonography to screen a population group of a remote island; at average risk for colorectal cancer

    Energy Technology Data Exchange (ETDEWEB)

    Lefere, Philippe, E-mail: radiologie@skynet.be [VCTC, Virtual Colonoscopy Teaching Centre, Akkerstraat 32c, B-8830 Hooglede (Belgium); Silva, Celso, E-mail: caras@uma.pt [Human Anatomy of Medical Course, University of Madeira, Praça do Município, 9000-082 Funchal (Portugal); Gryspeerdt, Stefaan, E-mail: stefaan@sgryspeerdt.be [VCTC, Virtual Colonoscopy Teaching Centre, Akkerstraat 32c, B-8830 Hooglede (Belgium); Rodrigues, António, E-mail: nucleo@nid.pt [Nucleo Imagem Diagnostica, Rua 5 De Outubro, 9000-216 Funchal (Portugal); Vasconcelos, Rita, E-mail: rita@uma.pt [Department of Engineering and Mathematics, University of Madeira, Praça do Município, 9000-082 Funchal (Portugal); Teixeira, Ricardo, E-mail: j.teixeira1947@gmail.com [Department of Gastroenterology, Central Hospital of Funchal, Avenida Luís de Camões, 9004513 Funchal (Portugal); Gouveia, Francisco Henriques de, E-mail: fhgouveia@netmadeira.com [LANA, Pathology Centre, Rua João Gago, 10, 9000-071 Funchal (Portugal)

    2013-06-15

    Purpose: To prospectively assess the performance of teleradiology-based CT colonography to screen a population group of an island, at average risk for colorectal cancer. Materials and methods: A cohort of 514 patients living in Madeira, Portugal, was enrolled in the study. Institutional review board approval was obtained and all patients signed an informed consent. All patients underwent both CT colonography and optical colonoscopy. CT colonography was interpreted by an experienced radiologist at a remote centre using tele-radiology. Per-patient sensitivity, specificity, positive (PPV) and negative (NPV) predictive values with 95% confidence intervals (95%CI) were calculated for colorectal adenomas and advanced neoplasia ≥6 mm. Results: 510 patients were included in the study. CT colonography obtained a per-patient sensitivity, specificity, PPV and, NPV for adenomas ≥6 mm of 98.11% (88.6–99.9% 95% CI), 90.97% (87.8–93.4% 95% CI), 56.52% (45.8–66.7% 95% CI), 99.75% (98.4–99.9% 95% CI). For advanced neoplasia ≥6 mm per-patient sensitivity, specificity, PPV and, NPV were 100% (86.7–100% 95% CI), 87.07% (83.6–89.9% 95% CI), 34.78% (25.3–45.5% 95% CI) and 100% (98.8–100% 95% CI), respectively. Conclusion: In this prospective trial, teleradiology-based CT colonography was accurate to screen a patient cohort of a remote island, at average risk for colorectal cancer.

  18. Femoral anteversion measured by ultrasound and CT: a comparative study

    Energy Technology Data Exchange (ETDEWEB)

    Aamodt, A. [Dept. of Orthopaedic Surgery, Trondheim Univ. Hospital (Norway); Terjesen, T. [Dept. of Orthopaedic Surgery, Trondheim Univ. Hospital (Norway); Eine, J. [Dept. of Orthopaedic Surgery, Trondheim Univ. Hospital (Norway); Kvistad, K.A. [Dept. of Radiology, Trondheim Univ. Hospital (Norway)

    1995-02-01

    Both computed tomography (CT) and ultrasonography have been used successfully to estimate the femoral anteversion (AV) angle. In this study, AV angles in 20 human adult femurs were determined by ultrasonography and CT and the measurements compared. On CT the real AV angle was measured as the angle between the head-neck centreline and the posterior condylar plane. In addition, the angle between the anterior head-trochanter (HT) tangent and the posterior condylar plane was determined. The latter angle was also measured by ultrasonography using the tilted transducer technique. The mean interobserver variation in the ultrasound measurements was 1.9 . We found ultrasonography to correlate very well with CT, both when comparing with the HT angle (r=0.95) and with the AV angle (r=0.93). The HT angle was on average 4 greater than the AV angle. In this study the accuracy of ultrasonography was {+-}5 and the method is recommended for screening in patients with rotational disorders of the femur. (orig.)

  19. A decrease in lung cancer mortality following the introduction of low-dose chest CT screening in Hitachi, Japan.

    Science.gov (United States)

    Nawa, Takeshi; Nakagawa, Tohru; Mizoue, Tetsuya; Kusano, Suzushi; Chonan, Tatsuya; Hayashihara, Kenji; Suito, Tetsushi; Endo, Katsuyuki

    2012-12-01

    Recent US clinical trial demonstrated that CT screening prevents lung cancer death among high risk individuals. However, it remains unclear whether wide implementation of low-dose CT screening for lung cancer can decrease mortality in the community. Among residents in Hitachi City (Japan), where nearly 40% of inhabitants aged 50-69 years were estimated to have participated in the screening at least once from 1998 through 2009, the trend of lung cancer mortality was described in relation to the timing of implementation of the CT screening. Cancer mortality data were obtained from regional cancer registry and standardized mortality ratio (SMR) of lung cancer was calculated for each 5-year period during 1995-2009. In both men and women aged 60 years or older, age-specific lung cancer mortality rates were generally lower during 2005-2009 as compared with those during 1995-2004. For combined men and women aged 50-79 years, SMR was nearly unity prior to or during introductory phase of CT screening and during early period of implementation; however, it was significantly decreased during 2005-2009, well after the implementation of CT screening, with SMR (95% confidence interval) being 0.76 (0.67-0.86). Results suggest that wide implementation of low-dose chest CT screening may decrease lung cancer mortality in the community 4-8 years after introduction of the screening.

  20. Body Size-Specific Organ and Effective Doses of Chest CT Screening Examinations of the National Lung Screening Trial.

    Science.gov (United States)

    Lee, Choonsik; Flynn, Michael J; Judy, Phillip F; Cody, Dianna D; Bolch, Wesley E; Kruger, Randell L

    2017-05-01

    We calculated body size-specific organ and effective doses for 23,734 participants in the National Lung Screening Trial (NLST) using a CT dose calculator. We collected participant-specific technical parameters of 23,734 participants who underwent CT in the clinical trial. For each participant, we calculated two sets of organ doses using two methods. First, we computed body size-specific organ and effective doses using the National Cancer Institute CT (NCICT) dosimetry program, which is based on dose coefficients derived from a library of body size-dependent adult male and female computational phantoms. We then recalculated organ and effective doses using dose coefficients from reference size phantoms for all examinations to investigate potential errors caused by the lack of body size consideration in the dose calculations. The underweight participants (body mass index [BMI; weight in kilograms divided by the square of height in meters] 30) (3.90 mGy). Thyroid doses were approximately 1.3- to 1.6-fold greater than the lung doses (6.3-6.5 mGy). The reference phantom-based dose calculation underestimates the body size-specific lung dose by up to 50% for the underweight participants and overestimates that value by up to 200% for the overweight participants. The median effective dose ranges from 2.01 mSv in obese participants to 2.80 mSv in underweight participants. Body size-specific organ and effective doses were computed for 23,734 NLST participants who underwent low-dose CT screening. The use of reference size phantoms can lead to significant errors in organ dose estimates when body size is not considered in the dose assessment.

  1. Screening for occult malignancy with FDG-PET/CT in patients with unprovoked venous thromboembolism.

    Science.gov (United States)

    Alfonso, Ana; Redondo, Margarita; Rubio, Tomás; Del Olmo, Beatriz; Rodríguez-Wilhelmi, Pablo; García-Velloso, María J; Richter, José A; Páramo, José A; Lecumberri, Ramón

    2013-11-01

    Extensive screening strategies to detect occult cancer in patients with unprovoked venous thromboembolism (VTE) are complex and no benefit in terms of survival has been reported. FDG-PET/CT (2-[F-18] fluoro-2-deoxy-D-glucose positron emission tomography combined with computed tomography), a noninvasive technique for the diagnosis and staging of malignancies, could be useful in this setting. Consecutive patients ≥ 50 years with a first unprovoked VTE episode were prospectively included. Screening with FDG-PET/CT was performed 3-4 weeks after the index event. If positive, appropriate diagnostic work-up was programmed. Clinical follow-up continued for 2 years. Blood samples were collected to assess coagulation biomarkers. FDG-PET/CT was negative in 68/99 patients (68.7%), while suspicious FDG uptake was detected in 31/99 patients (31.3%). Additional diagnostic work-up confirmed a malignancy in 7/31 patients (22.6%), with six of them at early stage. During follow-up, two patients with negative FDG-PET/CT were diagnosed with cancer. Sensitivity (S), positive (PPV) and negative predictive values (NPV) of FDG-PET/CT as single tool for the detection of occult malignancy were 77.8% (95% CI: 0.51-1), 22.6% (95% CI: 0.08-0.37) and 97.1% (95% CI: 0.93-1), respectively. Median tissue factor (TF) activity in patients with occult cancer was 5.38 pM vs. 2.40 pM in those without cancer (p = 0.03). Limitation of FDG-PET/CT screening to patients with TF activity > 2.8 pM would improve the PPV to 37.5% and reduce the costs of a single cancer diagnosis from 20,711€ to 11,670€. FDG-PET/CT is feasible for the screening of occult cancer in patients with unprovoked VTE, showing high S and NPV. The addition of TF activity determination may be useful for patient selection.

  2. International Association for the Study of Lung Cancer Computed Tomography Screening Workshop 2011 report

    DEFF Research Database (Denmark)

    Field, John K; Smith, Robert A; Aberle, Denise R

    2011-01-01

    The International Association for the Study of Lung Cancer (IASLC) Board of Directors convened a computed tomography (CT) Screening Task Force to develop an IASLC position statement, after the National Cancer Institute press statement from the National Lung Screening Trial showed that lung cancer......, which are summarized in this report. The recommendation from the workshop, and supported by the IASLC Board of Directors, was to set up the Strategic CT Screening Advisory Committee (IASLC-SSAC). The Strategic CT Screening Advisory Committee is currently engaging professional societies and organizations...

  3. STUDY ANALYSIS OF ACUTE PANCREATITIS BY CT

    Directory of Open Access Journals (Sweden)

    Bulabai

    2015-11-01

    Full Text Available AIM: Study analysis of pancreatitis by computed tomography in terms of morphology of pancreas in acute pancreatitis, complications of pancreatitis and duration of hospital stay by grading the severity of disease using Modified CT severity index. MATERIAL AND METHOD: This prospective study of 100 patients suspected of pancreatitis was evaluated with multidetector spiral CT scanner, somatom, (Spirit Siemens at Tertiary care center, for period of one year. The series consists of patients of pancreatitis which were clinically diagnosed and sent directly for CT examination and in the patients in whom abdominal ultrasound examination was suggestive of pancreatitis. Water with iodinated contrast is used as oral contrast so as to distend the stomach and small bowel followed by IV contrast study. All images were viewed at window width-300, window level-40 with a wide and narrow window setting as necessary. RESULT ANALYSIS: Acute Pancreatitis was more common in males than females with alcohol consumption was the commonest etiological factor in 79.5%. In contrary biliary pathology was the commonest factor in females of 41.6%. Among the 100 cases 41 patients (41% developed complications. CONCLUSION: We had documented a statistically significant correlation between the numeric score obtained with the Modified CT Severity index and the presence of infection, the need for surgery and percutaneous interventions, and the length of the hospital stay. Finally the modified CTSI closely indicates with patient outcome in all study parameters, especially with the length of the hospital stay and the development of organ failure.

  4. CT-Screening for lung cancer does not increase the use of anxiolytic or antidepressant medication

    Directory of Open Access Journals (Sweden)

    Kaerlev Linda

    2012-05-01

    Full Text Available Abstract Background CT screening for lung cancer has recently been shown to reduce lung cancer mortality, but screening may have adverse mental health effects. We calculated risk ratios for prescription of anti-depressive (AD or anxiolytic (AX medication redeemed at Danish pharmacies for participants in The Danish Lung Cancer Screening Trial (DLCST. Methods The DLCST was a randomized clinical trial which comprised 4,104 former or present smokers who were randomized from 12 May 2004 to 20 June 2006 to either CT scan of the chest, lung-function test and filling in questionnaires annually for five years in the period 1 April 2006–31 March 2010 (n = 2,052, or to a control group (n = 2,052 receiving similar procedures except CT scan. We used CT scan intervention group versus control group status as exposure. The follow-up period for use of AD or AX was three years. Baseline data on civil status, socioeconomic status, and co-morbidity as well as outcome data on AD and AX were obtained by linkage to national registries. Results The intervention and the control groups did not differ by age, gender, civil status, socio-economic position, co-morbidity index or former use of AD or AX. The adjusted risk ratio for at least one recipe of AD or AX in the CT intervention group during follow-up was not increased when adjusting for previous use of AD or AX, HR 1.00, 95 % CI (0.90-1.12. Similar results were seen when excluding subjects using AD or AX in a four-month or two-year period before baseline, when analyzing AD and AX separately, or requiring at least two recipes. Conclusions We found no indications that participation in a lung cancer CT-screening program increases the risk of specific adverse mental health outcomes. Trial registration Clinical Trials.gov Protocol Registration System (NCT00496977.

  5. Detection of flat colorectal polyps at screening CT colonography in comparison with conventional polypoid lesions

    Energy Technology Data Exchange (ETDEWEB)

    Sakamoto, Takashi; Urata, Joji [Diagnostic Imaging Center, Saiseikai Kumamoto Hospital, Kumamoto (Japan); Mitsuzaki, Katsuhiko; Matsuda, Katsuhiko; Kawakami, Megumi [Medical Examination Center, Saiseikai Kumamoto Hospital, Kumamoto (Japan); Utsunomiya, Daisuke; Yamamura, Sadahiro; Yamashita, Yasuyuki [Diagnostic Radiology, Faculty of Life Sciences, Kumamoto Univ., Kumamoto (Japan)], e-mail: utsunomi@kumamoto-u.ac.jp

    2012-09-15

    Background: Although the screening of small, flat polyps is clinically important, the role of CT colonography (CTC) screening in their detection has not been thoroughly investigated. Purpose: To evaluate the detection capability and usefulness of CTC in the screening of flat and polypoid lesions by comparing CTC with optic colonoscopy findings as the gold standard. Material and Methods: We evaluated the CTC detection capability for flat colorectal polyps with a flat surface and a height not exceeding 3 mm (n = 42) by comparing to conventional polypoid lesions (n = 418) according to the polyp diameter. Four types of reconstruction images including multiplanar reconstruction, volume rendering, virtual gross pathology, and virtual endoscopic images were used for visual analysis. We compared the abilities of the four reconstructions for polyp visualization. Results: Detection sensitivity for flat polyps was 31.3 %, 44.4 %, and 87.5 % for lesions measuring 2-3 mm, 4-5 mm, and {>=}6 mm, respectively; the corresponding sensitivity for polypoid lesions was 47.6 %, 79.0 %, and 91.7 %. The overall sensitivity for flat lesions (47.6%) was significantly lower than polypoid lesions (64.1%). Virtual endoscopic imaging showed best visualization among the four reconstructions. Colon cancers were detected in eight patients by optic colonoscopy, and CTC detected colon cancers in all eight patients. Conclusion: CTC using 64-row multidetector CT is useful for colon cancer screening to detect colorectal polyps while the detection of small, flat lesions is still challenging.

  6. Effects of Iterative Reconstruction Algorithms on Computer-assisted Detection (CAD) Software for Lung Nodules in Ultra-low-dose CT for Lung Cancer Screening.

    Science.gov (United States)

    Nomura, Yukihiro; Higaki, Toru; Fujita, Masayo; Miki, Soichiro; Awaya, Yoshikazu; Nakanishi, Toshio; Yoshikawa, Takeharu; Hayashi, Naoto; Awai, Kazuo

    2017-02-01

    This study aimed to evaluate the effects of iterative reconstruction (IR) algorithms on computer-assisted detection (CAD) software for lung nodules in ultra-low-dose computed tomography (ULD-CT) for lung cancer screening. We selected 85 subjects who underwent both a low-dose CT (LD-CT) scan and an additional ULD-CT scan in our lung cancer screening program for high-risk populations. The LD-CT scans were reconstructed with filtered back projection (FBP; LD-FBP). The ULD-CT scans were reconstructed with FBP (ULD-FBP), adaptive iterative dose reduction 3D (AIDR 3D; ULD-AIDR 3D), and forward projected model-based IR solution (FIRST; ULD-FIRST). CAD software for lung nodules was applied to each image dataset, and the performance of the CAD software was compared among the different IR algorithms. The mean volume CT dose indexes were 3.02 mGy (LD-CT) and 0.30 mGy (ULD-CT). For overall nodules, the sensitivities of CAD software at 3.0 false positives per case were 78.7% (LD-FBP), 9.3% (ULD-FBP), 69.4% (ULD-AIDR 3D), and 77.8% (ULD-FIRST). Statistical analysis showed that the sensitivities of ULD-AIDR 3D and ULD-FIRST were significantly higher than that of ULD-FBP (P CAD software in ULD-CT was improved by using IR algorithms. In particular, the performance of CAD in ULD-FIRST was almost equivalent to that in LD-FBP. Copyright © 2017 The Association of University Radiologists. Published by Elsevier Inc. All rights reserved.

  7. Optimization of the protocols for the use of contrast agents in PET/CT studies.

    Science.gov (United States)

    Pelegrí Martínez, L; Kohan, A A; Vercher Conejero, J L

    The introduction of PET/CT scanners in clinical practice in 1998 has improved care for oncologic patients throughout the clinical pathway, from the initial diagnosis of disease through the evaluation of the response to treatment to screening for possible recurrence. The CT component of a PET/CT study is used to correct the attenuation of PET studies; CT also provides anatomic information about the distribution of the radiotracer. CT is especially useful in situations where PET alone can lead to false positives and false negatives, and CT thereby improves the diagnostic performance of PET. The use of intravenous or oral contrast agents and optimal CT protocols have improved the detection and characterization of lesions. However, there are circumstances in which the systematic use of contrast agents is not justified. The standard acquisition in PET/CT scanners is the whole body protocol, but this can lead to artifacts due to the position of patients and respiratory movements between the CT and PET acquisitions. This article discusses these aspects from a constructive perspective with the aim of maximizing the diagnostic potential of PET/CT and providing better care for patients.

  8. Radiation dose and cancer risk from pediatric CT examinations on 64-slice CT: A phantom study

    Energy Technology Data Exchange (ETDEWEB)

    Feng Shiting [Department of Radiology, The First Affiliated Hospital, Sun Yat-Sen University, Guangzhou (China); Law, Martin Wai-Ming [Department of Clinical Oncology, Queen Mary Hospital (Hong Kong); Huang Bingsheng [Department of Diagnostic Radiology, University of Hong Kong (Hong Kong); Ng, Sherry [Department of Clinical Oncology, Queen Mary Hospital (Hong Kong); Li Ziping; Meng Quanfei [Department of Radiology, The First Affiliated Hospital, Sun Yat-Sen University, Guangzhou (China); Khong, Pek-Lan, E-mail: plkhong@hkucc.hku.hk [Department of Diagnostic Radiology, University of Hong Kong (Hong Kong)

    2010-11-15

    Objective: To measure the radiation dose from CT scans in an anthropomorphic phantom using a 64-slice MDCT, and to estimate the associated cancer risk. Materials and methods: Organ doses were measured with a 5-year-old phantom and thermoluminescent dosimeters. Four protocols; head CT, thorax CT, abdomen CT and pelvis CT were studied. Cancer risks, in the form of lifetime attributable risk (LAR) of cancer incidence, were estimated by linear extrapolation using the organ radiation doses and the LAR data. Results: The effective doses for head, thorax, abdomen and pelvis CT, were 0.7 mSv, 3.5 mSv, 3.0 mSv, 1.3 mSv respectively. The organs with the highest dose were; for head CT, salivary gland (22.33 mGy); for thorax CT, breast (7.89 mGy); for abdomen CT, colon (6.62 mGy); for pelvis CT, bladder (4.28 mGy). The corresponding LARs for boys and girls were 0.015-0.053% and 0.034-0.155% respectively. The organs with highest LARs were; for head CT, thyroid gland (0.003% for boys, 0.015% for girls); for thorax CT, lung for boys (0.014%) and breast for girls (0.069%); for abdomen CT, colon for boys (0.017%) and lung for girls (0.016%); for pelvis CT, bladder for both boys and girls (0.008%). Conclusion: The effective doses from these common pediatric CT examinations ranged from 0.7 mSv to 3.5 mSv and the associated lifetime cancer risks were found to be up to 0.16%, with some organs of higher radiosensitivity including breast, thyroid gland, colon and lungs.

  9. Monitoring of smoking-induced emphysema with CT in a lung cancer screening setting : Detection of real increase in extent of emphysema

    NARCIS (Netherlands)

    Gietema, Hester A.; Schilham, Arnold M.; van Ginneken, Bram; van Klaveren, Rob J.; Lammers, Jan Willem J.; Prokop, Mathias

    2007-01-01

    Purose: To retrospectively establish the minimum increase in emphysema score (ES) required for detection of real Increased extent of emphysema with 95% confidence by using multi-detector row computed tomography (CT) in a lung cancer screening setting. Materials and Methods The study was a substudy o

  10. Five year colorectal cancer outcomes in a large negative CT colonography screening cohort

    Energy Technology Data Exchange (ETDEWEB)

    Kim, David H.; Pooler, B.D.; Pickhardt, Perry J. [University of Wisconsin School of Medicine and Public Health, Department of Radiology, Madison, WI (United States); Weiss, Jennifer M. [University of Wisconsin School of Medicine and Public Health, Section of Gastroenterology, Department of Internal Medicine, Madison, WI (United States)

    2012-07-15

    To assess the 5-year incidence of clinically presenting colorectal cancers following a negative CT colonography (CTC) screening examination, as few patient outcome data regarding a negative CTC screening result exist. Negative CTC screening patients (n = 1,050) in the University of Wisconsin Health system over a 14-month period were included. An electronic medical record (EMR) review was undertaken, encompassing provider, colonoscopy, imaging and histopathology reports. Incident colorectal cancers and other important GI tumours were recorded. Of the 1,050 cohort (mean [{+-}SD] age 56.9 {+-} 7.4 years), 39 (3.7%) patients were excluded owing to lack of follow-up within our system beyond the initial screening CTC. The remaining 1,011 patients were followed for an average of 4.73 {+-} 1.15 years. One incident colorectal adenocarcinoma represented a crude cancer incidence of 0.2 cancers per 1,000 patient years. EMR revealed 14 additional patients with clinically important GI tumours including: advanced adenomas (n = 11), appendiceal goblet cell carcinoid (n = 1), appendiceal mucinous adenoma (n = 1) and metastatic ileocolonic carcinoid (n = 1). All positive patients including the incident carcinoma are alive at the time of review. Clinically presenting colorectal adenocarcinoma is rare in the 5 years following negative screening CTC, suggesting that current strategies, including non-reporting of diminutive lesions, are appropriate. (orig.)

  11. WE-B-207-01: CT Lung Cancer Screening and the Medical Physicist: Background, Findings and Participant Dosimetry Summary of the National Lung Screening Trial (NLST)

    Energy Technology Data Exchange (ETDEWEB)

    Kruger, R. [Marshfield Clinic, Marshfield, WI (United States)

    2015-06-15

    The US National Lung Screening Trial (NLST) was a multi-center randomized, controlled trial comparing a low-dose CT (LDCT) to posterior-anterior (PA) chest x-ray (CXR) in screening older, current and former heavy smokers for early detection of lung cancer. Recruitment was launched in September 2002 and ended in April 2004 when 53,454 participants had been randomized at 33 screening sites in equal proportions. Funded by the National Cancer Institute this trial demonstrated that LDCT screening reduced lung cancer mortality. The US Preventive Services Task Force (USPSTF) cited NLST findings and conclusions in its deliberations and analysis of lung cancer screening. Under the 2010 Patient Protection and Affordable Care Act, the USPSTF favorable recommendation regarding lung cancer CT screening assisted in obtaining third-party payers coverage for screening. The objective of this session is to provide an introduction to the NLST and the trial findings, in addition to a comprehensive review of the dosimetry investigations and assessments completed using individual NLST participant CT and CXR examinations. Session presentations will review and discuss the findings of two independent assessments, a CXR assessment and the findings of a CT investigation calculating individual organ dosimetry values. The CXR assessment reviewed a total of 73,733 chest x-ray exams that were performed on 92 chest imaging systems of which 66,157 participant examinations were used. The CT organ dosimetry investigation collected scan parameters from 23,773 CT examinations; a subset of the 75,133 CT examinations performed using 97 multi-detector CT scanners. Organ dose conversion coefficients were calculated using a Monte Carlo code. An experimentally-validated CT scanner simulation was coupled with 193 adult hybrid computational phantoms representing the height and weight of the current U.S. population. The dose to selected organs was calculated using the organ dose library and the abstracted scan

  12. The Value of Calcium-scoring CT for Ischemic Cardiovascular Disease Screening

    Energy Technology Data Exchange (ETDEWEB)

    Oh, Jung Hoan; An, Sung Min [Dept. of Radiological Science, Gachon University Science and Health, Incheon (Korea, Republic of)

    2009-03-15

    The cardiovascular disease has been known as a common cause of death for a long time in the west. The eating habits of Asia, including Korea, have changed recently, so that this disease is also a problem in Asia now. Annual Report on the Cause of Death Statistics from 1996 to 2006 reported that the cardiovascular disease would become the number one cause of death in the next years. Therefore we realize that more accurate examination is required. The aim of this study was to investigate the accuracy of Calcium-scoring CT and the relationship between risk factor and quantitative scores of Calcium-scoring CT. Through this study we expect that the national public health will be improved. Seventy patients with chest pain were chosen at random. The patients were undergone both coronary CT antigraphy and Calcium - scoring CT at G hospital in Incheon from February 1 to June 30, 2008. The result of the Calcium-scoring CT showed its usefulness for Ischemic cardiovascular disease, with an accuracy similar to that of exercise/pharmacologic stress or ECG when it is difficult for a patient to exercise due to joint problems, aging or for other reasons.

  13. Serial volumetric registration of pulmonary CT studies

    Science.gov (United States)

    Silva, José Silvestre; Silva, Augusto; Sousa Santos, Beatriz

    2008-03-01

    Detailed morphological analysis of pulmonary structures and tissue, provided by modern CT scanners, is of utmost importance as in the case of oncological applications both for diagnosis, treatment, and follow-up. In this case, a patient may go through several tomographic studies throughout a period of time originating volumetric sets of image data that must be appropriately registered in order to track suspicious radiological findings. The structures or regions of interest may change their position or shape in CT exams acquired at different moments, due to postural, physiologic or pathologic changes, so, the exams should be registered before any follow-up information can be extracted. Postural mismatching throughout time is practically impossible to avoid being particularly evident when imaging is performed at the limiting spatial resolution. In this paper, we propose a method for intra-patient registration of pulmonary CT studies, to assist in the management of the oncological pathology. Our method takes advantage of prior segmentation work. In the first step, the pulmonary segmentation is performed where trachea and main bronchi are identified. Then, the registration method proceeds with a longitudinal alignment based on morphological features of the lungs, such as the position of the carina, the pulmonary areas, the centers of mass and the pulmonary trans-axial principal axis. The final step corresponds to the trans-axial registration of the corresponding pulmonary masked regions. This is accomplished by a pairwise sectional registration process driven by an iterative search of the affine transformation parameters leading to optimal similarity metrics. Results with several cases of intra-patient, intra-modality registration, up to 7 time points, show that this method provides accurate registration which is needed for quantitative tracking of lesions and the development of image fusion strategies that may effectively assist the follow-up process.

  14. Screening and detection of blunt vertebral artery injury in patients with upper cervical fractures: The role of cervical CT and CT angiography

    Energy Technology Data Exchange (ETDEWEB)

    Payabvash, Seyedmehdi, E-mail: spayab@gmail.com [Department of Radiology, University of Minnesota Medical Center, Minneapolis, MN (United States); McKinney, Alexander M., E-mail: mckinrad@umn.edu [Department of Radiology, Hennepin County Medical Center, 701 Park Avenue, Minneapolis, MN (United States); McKinney, Zeke J., E-mail: zeke.mckinney@hcmed.org [Department of Radiology, Hennepin County Medical Center, 701 Park Avenue, Minneapolis, MN (United States); Palmer, Christopher S., E-mail: palme018@umn.edu [Department of Radiology, Hennepin County Medical Center, 701 Park Avenue, Minneapolis, MN (United States); Truwit, Charles L., E-mail: truwit@umn.edu [Department of Radiology, Hennepin County Medical Center, 701 Park Avenue, Minneapolis, MN (United States)

    2014-03-15

    Objective: To evaluate the clinical utility of nonenhanced CT (NECT)-based screening criteria and CTA in detection of blunt vertebral artery injury (BVAI) in trauma patients with C1 and/or C2 fractures. Methods: We retrospectively reviewed the clinical records of all blunt trauma patients with C1 and/or C2 fractures between 8/2006 and 9/2011. Cervical CTA was prompted by cervical fractures involving/adjacent to a transverse foramen, and/or subluxation on NECT. Two neuroradiologists independently reviewed the CTA studies, and graded the BVAI. Results: 210 patients were included; of these, 124 underwent CTA (21/124 with digital subtraction angiography, DSA), and 2 underwent DSA only. Overall, 30/126 suffered BVAI. Among 21 patients who underwent both CTA and DSA, there was 1 false negative and 1 false positive (both grade 1). There was strong interobserver agreement regarding CTA-based BVAI detection (kappa = 0.93, p < 0.001) and grading (kappa = 0.90, p < 0001). Only 3/30 BVAI patients suffered a posterior circulation stroke; none of the patients who had a negative CTA or were not selected for CTA, based on NECT screening criteria, suffered symptomatic stroke. While C1/C2 comminuted fracture was more common in patients with high grade BVAI (p = 0.039), simultaneous C3–C7 comminuted fracture increased the overall BVAI risk (p = 0.011). Conclusion: CTA reliably detects symptomatic BVAI in patients with upper cervical fractures. Utilization of NECT-based screening criteria such as transverse foraminal involvement or subluxation may be adequate in deciding whether to perform CTA, as no patients who were not selected for CTA suffered a symptomatic stroke. However, CTA may miss lower grade, asymptomatic BVAI.

  15. Simple pulmonary eosinophilia detected at low-dose CT for lung cancer screening

    Energy Technology Data Exchange (ETDEWEB)

    Jeon, Kyung Nyeo; Bae, Kyung Soo; Kim, Ho Cheol [Gyeongsang National University Hospital, Jinju (Korea, Republic of)] (and others)

    2006-05-15

    The aim of this study was to evaluate the frequency, radiologic findings and clinical significance of the simple pulmonary eosinophilia (SPE) that was diagnosed among the asymptomatic patients who underwent low-dose CT scans for the early detection of lung cancer. From June 2003 to May 2005, 1,239 asymptomatic patients (1,275 examinations) who visited the health promotion center in our hospital and who underwent low-dose CT were enrolled in this study. SPE was defined as the presence of > 500 eosinophils per microliter of peripheral blood and the presence of abnormal parenchymal lesions such as nodules, airspace consolidation or areas of ground-glass attenuation (GGA) on CT, and there was spontaneous resolution or migration of the lesions on the follow-up examination. We analyzed the CT findings of SPE and we investigated the relationship between the occurrence of SPE and the season, smoking and the presence of parasite infestation. 36 patients were finally diagnosed as having SPE; this was 24% of the 153 patients who were diagnosed with parasite infestation and 2.8% of the total low-dose CT scans. These 36 patients consisted of 31 men and 5 women with a mean age 45.7 years. There was no significant relationship between SPE and the presence of parasite infestation, smoking or gender. Among the patients with peripheral blood eosinophilia, the eosinophil count was significantly higher in the patients with SPE than that in the patients without pulmonary infiltration ({rho} < 0.05). SPE more frequently occurred in winter and spring than in summer and autumn ({rho} < 0.05). The CT findings were single or multiple nodules in 18 patients, nodules and focal GGA in 9 patients and GGA only in 9 patients. Most of the nodules were less than 10 mm (88%, 49/56) in diameter and they showed an ill-defined margin (82%, n = 46); 30% of the nodules (n = 17) showed a halo around them. Simple pulmonary eosinophilia can be suggested as the cause if single or multiple ill-defined nodules

  16. International Association for the Study of Lung Cancer Computed Tomography Screening Workshop 2011 report

    DEFF Research Database (Denmark)

    Field, John K; Smith, Robert A; Aberle, Denise R;

    2011-01-01

    The International Association for the Study of Lung Cancer (IASLC) Board of Directors convened a computed tomography (CT) Screening Task Force to develop an IASLC position statement, after the National Cancer Institute press statement from the National Lung Screening Trial showed that lung cancer...

  17. International Association for the Study of Lung Cancer Computed Tomography Screening Workshop 2011 Report

    NARCIS (Netherlands)

    Field, John K.; Smith, Robert A.; Aberle, Denise R.; Oudkerk, Matthijs; Baldwin, David R.; Yankelevitz, David; Pedersen, Jesper Holst; Swanson, Scott James; Travis, William D.; Wisbuba, Ignacio I.; Noguchi, Masayuki; Mulshine, Jim L.

    2012-01-01

    The International Association for the Study of Lung Cancer (IASLC) Board of Directors convened a computed tomography (CT) Screening Task Force to develop an IASLC position statement, after the National Cancer Institute press statement from the National Lung Screening Trial showed that lung cancer de

  18. International Association for the Study of Lung Cancer Computed Tomography Screening Workshop 2011 Report

    NARCIS (Netherlands)

    Field, John K.; Smith, Robert A.; Aberle, Denise R.; Oudkerk, Matthijs; Baldwin, David R.; Yankelevitz, David; Pedersen, Jesper Holst; Swanson, Scott James; Travis, William D.; Wisbuba, Ignacio I.; Noguchi, Masayuki; Mulshine, Jim L.

    The International Association for the Study of Lung Cancer (IASLC) Board of Directors convened a computed tomography (CT) Screening Task Force to develop an IASLC position statement, after the National Cancer Institute press statement from the National Lung Screening Trial showed that lung cancer

  19. Status and prospects of frozen soil studies using CT technology

    Institute of Scientific and Technical Information of China (English)

    ShiJie Chen; ShuPing Zhao; Wei Ma; QianTao Zhu; LiLi Xing

    2014-01-01

    This paper introduces the characteristics of Computed Tomography (CT) technology and reviews its history, current situation, representative achievements, and use of using CT technology on frozen soil study, including auxiliary equipment specially de-signed for frozen soil studies. CT numbers are used to analyze frozen soil internal structure change, defining and exploring dam-age evolution, and use of CT images on observing soil mesostructure. Finally, this paper presents existing problems confronted by using CT in frozen soil studies, possible solutions and challenges, among which, we introduce high quality CT image processing for frozen soils, and relations between CT number change and each component change on frozen soil samples within the region of interest. It is shown that present CT technology is one of the most ideal and effective technology to study frozen soil mesostructure using non-destructive testing. CT technology will play a key role in the study and development in the field of frozen soil by means of auxiliary equipment and the digital imaging processing.

  20. CT scan screening is associated with increased distress among subjects of the APExS

    Directory of Open Access Journals (Sweden)

    Stoufflet Audrey

    2010-10-01

    Full Text Available Abstract Background The aim of this study was to assess the psychological consequences of HRCT scan screening in retired asbestos-exposed workers. Methods A HRCT-scan screening program for asbestos-related diseases was carried out in four regions of France. At baseline (T1, subjects filled in self-administered occupational questionnaires. In two of the regions, subjects also received a validated psychological scale, namely the psychological consequences questionnaire (PCQ. The physician was required to provide the subject with the results of the HRCT scan at a final visit. A second assessment of psychological consequences was performed 6 months after the HRCT-scan examination (T2. PCQ scores were compared quantitatively (t-test, general linear model and qualitatively (chi²-test, logistic regression to screening results. Multivariate analyses were adjusted for gender, age, smoking, asbestos exposure and counseling. Results Among the 832 subjects included in this psychological impact study, HRCT-scan screening was associated with a significant increase of the psychological score 6 months after the examination relative to baseline values (8.31 to 10.08, p Conclusion This study suggests that HRCT-scan screening may be associated with increased distress in asbestos-exposed subjects. If confirmed, these results may have consequences for HRCT-scan screening recommendations.

  1. A virtual clinical trial using projection-based nodule insertion to determine radiologist reader performance in lung cancer screening CT

    Science.gov (United States)

    Yu, Lifeng; Hu, Qiyuan; Koo, Chi Wan; Takahashi, Edwin A.; Levin, David L.; Johnson, Tucker F.; Hora, Megan J.; Dirks, Shane; Chen, Baiyu; McMillan, Kyle; Leng, Shuai; Fletcher, J. G.; McCollough, Cynthia H.

    2017-03-01

    Task-based image quality assessment using model observers is promising to provide an efficient, quantitative, and objective approach to CT dose optimization. Before this approach can be reliably used in practice, its correlation with radiologist performance for the same clinical task needs to be established. Determining human observer performance for a well-defined clinical task, however, has always been a challenge due to the tremendous amount of efforts needed to collect a large number of positive cases. To overcome this challenge, we developed an accurate projection-based insertion technique. In this study, we present a virtual clinical trial using this tool and a low-dose simulation tool to determine radiologist performance on lung-nodule detection as a function of radiation dose, nodule type, nodule size, and reconstruction methods. The lesion insertion and low-dose simulation tools together were demonstrated to provide flexibility to generate realistically-appearing clinical cases under well-defined conditions. The reader performance data obtained in this virtual clinical trial can be used as the basis to develop model observers for lung nodule detection, as well as for dose and protocol optimization in lung cancer screening CT.

  2. Study of tuberculous meningitis by CT

    Energy Technology Data Exchange (ETDEWEB)

    Rovira, M.; Romero, F.; Torrent, O.; Ibarra, B.

    1980-04-01

    Computed tomography is a very valuable method by which the pathogenic evolution of tuberculous meningitis may be followed, thereby facilitating its differential diagnosis and controlling the efficiency of therapy. The initial miliary tuberculosis in the brain, very often unaccompanied by neurological symptoms, may offer very evident CT images. CT may also demonstrate the fibrogelatinous exudate which fills the basal cisterns and surrounds the arterial vessels which cross this region. Because of this, secondary arteritis is frequent and may be indirectly detected by CT in the form of foci of ischemic infarcts. Tuberculomas may be multiple, and are found equally in the cerebral and the cerebellar parenchyma. These tuberculomas present different images on CT, depending on the evolution of the disease at that moment. Hydrocephalus is a common complication of TM and is caused by a lack of reabsorption of the cerebrospinal fluid, or by an obstructive lesion in the ventricular drainage pathways due to a tuberculoma. This complication is usually easily identified by CT, which, moreover, permits the control of its evolution.

  3. Benefits and Harms of CT Screening for Lung Cancer: A Systematic Review

    Science.gov (United States)

    Bach, Peter B.; Mirkin, Joshua N.; Oliver, Thomas K.; Azzoli, Christopher G.; Berry, Don; Brawley, Otis W.; Byers, Tim; Colditz, Graham A.; Gould, Michael K.; Jett, James R.; Sabichi, Anita L.; Smith-Bindman, Rebecca; Wood, Douglas E.; Qaseem, Amir; Detterbeck, Frank C.

    2013-01-01

    Context Lung cancer is the leading cause of cancer death. Most patients are diagnosed with advanced disease, resulting in a very low five-year survival rate. Screening may reduce the risk of death from lung cancer. Objective A multi-society collaborative initiative (involving the American Cancer Society, the American College of Chest Physicians, the American Society of Clinical Oncology, and the National Comprehensive Cancer Network) was undertaken to conduct a systematic review of the evidence regarding the benefits and harms of lung cancer screening using low dose computed tomography (LDCT), in order to create the foundation for development of an evidence-based clinical guideline. Data Sources MEDLINE (OVID: 1996 to April 2012), EMBASE (OVID: 1996 to April 2012), and the Cochrane Library (April 2012). Study Selection Of 591 citations identified and reviewed, eight randomized controlled trials and 13 cohort studies of LDCT screening met criteria for inclusion. Primary outcomes were lung cancer mortality and all-cause mortality, and secondary outcomes included nodule detection, invasive procedures, follow-up tests, and smoking cessation. Data Extraction Critical appraisal using pre-defined criteria was conducted on individual studies and the overall body of evidence. Differences in data extracted by reviewers were adjudicated by consensus. Results Three randomized studies provided evidence on the impact of LDCT screening on lung cancer mortality, of which the National Lung Screening Trial was the most informative, demonstrating that among 53,454 enrolled, screening resulted in significantly fewer lung cancer deaths (356 vs 443 deaths; lung cancer-specific mortality, 247 vs 309 events per 100,000 person-years for LDCT and control groups, respectively; Relative Risk [RR] = 0.80, 95% Confidence Interval [CI] 0.73–0.93; Absolute Risk Reduction [ARR] = 0.33%, P=0.004). The other 2 smaller studies showed no such benefit. In terms of potential harms of LDCT screening

  4. Comparing CT colonography and flexible sigmoidoscopy: a randomised trial within a population-based screening programme.

    Science.gov (United States)

    Regge, Daniele; Iussich, Gabriella; Segnan, Nereo; Correale, Loredana; Hassan, Cesare; Arrigoni, Arrigo; Asnaghi, Roberto; Bestagini, Piero; Bulighin, Gianmarco; Cassinis, Maria Carla; Ederle, Andrea; Ferraris, Andrea; Galatola, Giovanni; Gallo, Teresa; Gandini, Giovanni; Garretti, Licia; Martina, Maria Cristina; Molinar, Daniela; Montemezzi, Stefania; Morra, Lia; Motton, Massimiliano; Occhipinti, Pietro; Pinali, Lucia; Soardi, Gian Alberto; Senore, Carlo

    2017-08-01

    The role of CT colonography (CTC) as a colorectal cancer (CRC) screening test is uncertain. The aim of our trial was to compare participation and detection rate (DR) with sigmoidoscopy (flexible sigmoidoscopy (FS)) and CTC in a screening setting. We conducted two randomised clinical trials (RCTs). (1) Participation RCT: individuals, aged 58 years, living in Turin (Italy), were randomly assigned to be invited to FS or CTC screening; (2) detection RCT: residents in northern Italy, aged 58-60, giving their consent to recruitment, were randomly allocated to CTC or FS. Polyps ≥6 mm at CTC, or 'high-risk' distal lesions at FS, were referred for colonoscopy (TC). Participation rate (proportion of invitees examined); DR of advanced adenomas or CRC (advanced neoplasia (AN)). Participation was 30.4% (298/980) for CTC and 27.4% (267/976) for FS (relative risk (RR) 1.1; 95% CI 0.98 to 1.29). Among men, participation was higher with CTC than with FS (34.1% vs 26.5%, p=0.011). In the detection RCT, 2673 subjects had FS and 2595 had CTC: the AN DR was 4.8% (127/2673, including 9 CRCs) with FS and 5.1% (133/2595, including 10 CRCs) with CTC (RR 1.08; 95% CI 0.85 to 1.37). Distal AN DR was 3.9% (109/2673) with FS and 2.9% (76/2595) with CTC (RR 0.72; 95% CI 0.54 to 0.96); proximal AN DR was 1.2% (34/2595) for FS vs 2.7% (69/2595) for CTC (RR 2.06; 95% CI 1.37 to 3.10). Participation and DR for FS and CTC were comparable. AN DR was twice as high in the proximal colon and lower in the distal colon with CTC than with FS. Men were more likely to participate in CTC screening. NCT01739608; Pre-results. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

  5. Coronary artery calcification detected by a mobile helical CT unit in a mass screening. The frequency and relationship to coronary risk factors and coronary artery disease

    Energy Technology Data Exchange (ETDEWEB)

    Itani, Yasutaka; Watanabe, Shigeru; Masuda, Yoshiaki [Chiba Univ. (Japan). School of Medicine; Hanamura, Kazuhisa; Asakura, Kazuhiro; Sone, Shusuke; Sunami, Yuko; Shimura, Akimitsu; Miyamoto, Tadaaki

    2001-06-01

    A strong relationship is known to exist between coronary artery disease (CAD) and coronary artery calcification (CAC) detected by CT. In this study, we investigated the frequency of CAC and the relationship between coronary risk factors, CAD and CAC in a mass screening using a mobile helical CT unit. The total number of participants was 10008 people undergoing a medical examination for lung cancer and tuberculosis using a mobile helical CT unit. We measured the CT density of the coronary artery to detect CAC. The CT density threshold for determining CAC was above +110HU. The frequency of CAC was 16.0% in the overall patient population and significantly higher in males than in females (20.6% vs 10.7%). Frequency increased with age in both genders. Hypertension and diabetes mellitus were significantly related to CAC. Smoking showed a correlation with CAC only in males. A significant relationship was observed between CAD and CAC in males. In particular, the relationship between them was strongest in males under 60 years of age. Furthermore, the odds ratio of CAC in predicting CAD increased with increasing risk factors in both genders. (author)

  6. The role of unenhanced CT alone for the management of headache in an emergency department. A feasibility study.

    Science.gov (United States)

    Rizk, Benoît; Platon, Alexandra; Tasu, Jean-Pierre; Becker, Christoph D; Mendes Pereira, Vitor; Perneger, Thomas; Shanmuganathan, Kathirkamanathan; Lövblad, Karl Olof; Poletti, Pierre-Alexandre

    2013-12-01

    To determine whether unenhanced CT alone could be sufficient for the screening of patients admitted with a suspicion of secondary headache in an emergency center. A feasibility study including consecutive patients admitted to our emergency department for acute non-traumatic headache, in whom a brain CT was required by the emergency physician, was conducted over a 3-month period of time. Patients with a suspicion of intracranial pathology, which can only be depicted by i.v. images (arterial dissection, venous thrombosis, or postoperative complication) were recorded but excluded from analysis. All patients underwent both unenhanced and i.v. enhanced cerebral CT, including CT angiography. Unenhanced CTs were reviewed by two radiologists, blinded to the clinical data, to the radiological reports and to the i.v. enhanced images. Unenhanced CT were sorted by the radiologists into three groups: (1) normal CT, (2) benign finding that could explain headache without need of injection of contrast media, (3) evidence of an intracranial pathology, requiring further imaging. Results were compared to i.v. enhanced CT images. A brain CT was required in 105 patients (34 males, 71 females) during the study period, 74 (70%) of them met our inclusion criteria. Fifty-nine (80%) were sorted in group 1 (normal), four (5%) in group 2, 11 (15%) in group 3. No further finding that could explain acute headache was found on i.v. CT images in patients of group 1 or 2. A significant pathology was confirmed by i.v. CT in all patients of group 3. This feasibility study suggests that a normal unenhanced CT might be sufficient to exclude the cause of headache in the initial screening of a selected group of patients admitted with cephalalgia. It compels researchers to perform further prospective studies to confirm the current data on a larger amount of patients. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

  7. A communicating Thread -CT- case study: JIWY

    NARCIS (Netherlands)

    Jovanovic, Dusko; Hilderink, Gerald H.; Broenink, Jan F.; Pascoe, P.W.J.; Loader, R.; Sunderman, V.

    2002-01-01

    This JIWY demonstrator is constructed in the context of the development of a design framework and software tools to efficiently support mechatronic engineers in developing sophisticated control computer code out of a set control laws. We use the CSP-based Communicating Threads -CT- library as the so

  8. A communicating Thread -CT- case study: JIWY

    NARCIS (Netherlands)

    Jovanovic, D.S.; Hilderink, G.H.; Broenink, Johannes F.; Pascoe, P.W.J.; Loader, R.; Sunderman, V.

    2002-01-01

    This JIWY demonstrator is constructed in the context of the development of a design framework and software tools to efficiently support mechatronic engineers in developing sophisticated control computer code out of a set control laws. We use the CSP-based Communicating Threads -CT- library as the so

  9. A communicating Thread -CT- case study: JIWY

    NARCIS (Netherlands)

    Jovanovic, D.S.; Hilderink, G.H.; Broenink, Johannes F.; Pascoe, P.W.J.; Loader, R.; Sunderman, V.

    2002-01-01

    This JIWY demonstrator is constructed in the context of the development of a design framework and software tools to efficiently support mechatronic engineers in developing sophisticated control computer code out of a set control laws. We use the CSP-based Communicating Threads -CT- library as the

  10. Discordance between CT and angiography in the PIOPED II study.

    Science.gov (United States)

    Wittram, Conrad; Waltman, Arthur C; Shepard, Jo-Anne O; Halpern, Elkan; Goodman, Lawrence R

    2007-09-01

    To retrospectively evaluate the causes of discordant computed tomographic (CT)-angiographic readings from the Prospective Investigation of Pulmonary Embolism Diagnosis, or PIOPED, II study. Institutional review board approval was obtained for this HIPAA-compliant study. Of 1036 patients suspected of having pulmonary embolism who were examined with CT, 226 underwent angiography; 206 patients had concordant results and 20 had discordant results according to two independent readers. Of these 20 patients, 10 were men and 10 were women (mean age, 49 years). Among the 20 studies with discordant results, central readers identified seven cases as negative and 13 as positive for pulmonary embolism at CT; these findings were reversed at angiography. Side-by-side comparisons of discordant studies were performed in consensus. The time between CT and angiography and all locations of pulmonary embolism vascular territory were recorded. The McNemar binomial test was used. One patient had false-positive findings at angiography, 13 patients had false-negative findings at angiography, and two patients had false-negative findings at CT. Four patients had true-negative findings at CT; however, findings were positive for thrombus at angiography. The sensitivity for the detection of pulmonary embolism was 87% for CT and 32% for angiography (P=.007). The largest missed thrombus at angiography was subsegmental in eight patients, segmental in two patients, and lobar in three patients; at CT it was subsegmental in two patients. The mean time between CT and angiography was 40 hours+/-21 (standard deviation) (range, 10-97 hours). In the interval between CT and angiography, thrombi can remain the same, resolve, develop, or result from angiography. Copyright (c) RSNA, 2007.

  11. Air trapping on chest CT is associated with worse ventilation distribution in infants with cystic fibrosis diagnosed following newborn screening.

    Directory of Open Access Journals (Sweden)

    Graham L Hall

    Full Text Available BACKGROUND: In school-aged children with cystic fibrosis (CF structural lung damage assessed using chest CT is associated with abnormal ventilation distribution. The primary objective of this analysis was to determine the relationships between ventilation distribution outcomes and the presence and extent of structural damage as assessed by chest CT in infants and young children with CF. METHODS: Data of infants and young children with CF diagnosed following newborn screening consecutively reviewed between August 2005 and December 2009 were analysed. Ventilation distribution (lung clearance index and the first and second moment ratios [LCI, M(1/M(0 and M(2/M(0, respectively], chest CT and airway pathology from bronchoalveolar lavage were determined at diagnosis and then annually. The chest CT scans were evaluated for the presence or absence of bronchiectasis and air trapping. RESULTS: Matched lung function, chest CT and pathology outcomes were available in 49 infants (31 male with bronchiectasis and air trapping present in 13 (27% and 24 (49% infants, respectively. The presence of bronchiectasis or air trapping was associated with increased M(2/M(0 but not LCI or M(1/M(0. There was a weak, but statistically significant association between the extent of air trapping and all ventilation distribution outcomes. CONCLUSION: These findings suggest that in early CF lung disease there are weak associations between ventilation distribution and lung damage from chest CT. These finding are in contrast to those reported in older children. These findings suggest that assessments of LCI could not be used to replace a chest CT scan for the assessment of structural lung disease in the first two years of life. Further research in which both MBW and chest CT outcomes are obtained is required to assess the role of ventilation distribution in tracking the progression of lung damage in infants with CF.

  12. Reliability analysis of visual ranking of coronary artery calcification on low-dose CT of the thorax for lung cancer screening: comparison with ECG-gated calcium scoring CT.

    Science.gov (United States)

    Kim, Yoon Kyung; Sung, Yon Mi; Cho, So Hyun; Park, Young Nam; Choi, Hye-Young

    2014-12-01

    Coronary artery calcification (CAC) is frequently detected on low-dose CT (LDCT) of the thorax. Concurrent assessment of CAC and lung cancer screening using LDCT is beneficial in terms of cost and radiation dose reduction. The aim of our study was to evaluate the reliability of visual ranking of positive CAC on LDCT compared to Agatston score (AS) on electrocardiogram (ECG)-gated calcium scoring CT. We studied 576 patients who were consecutively registered for health screening and undergoing both LDCT and ECG-gated calcium scoring CT. We excluded subjects with an AS of zero. The final study cohort included 117 patients with CAC (97 men; mean age, 53.4 ± 8.5). AS was used as the gold standard (mean score 166.0; range 0.4-3,719.3). Two board-certified radiologists and two radiology residents participated in an observer performance study. Visual ranking of CAC was performed according to four categories (1-10, 11-100, 101-400, and 401 or higher) for coronary artery disease risk stratification. Weighted kappa statistics were used to measure the degree of reliability on visual ranking of CAC on LDCT. The degree of reliability on visual ranking of CAC on LDCT compared to ECG-gated calcium scoring CT was excellent for board-certified radiologists and good for radiology residents. A high degree of association was observed with 71.6% of visual rankings in the same category as the Agatston category and 98.9% varying by no more than one category. Visual ranking of positive CAC on LDCT is reliable for predicting AS rank categorization.

  13. Appearances of screen-detected versus symptomatic colorectal cancers at CT colonography

    Energy Technology Data Exchange (ETDEWEB)

    Plumb, Andrew A.; Pathiraja, Fiona; Taylor, Stuart A.; Halligan, Steve [University College London, Centre for Medical Imaging, London (United Kingdom); Nickerson, Claire [Fulwood House, Public Health England, Sheffield (United Kingdom); Wooldrage, Katherine; Atkin, Wendy S. [Imperial College London, Department of Surgery and Cancer, London (United Kingdom); Burling, David [St Mark' s Hospital, Intestinal Imaging Centre, Harrow (United Kingdom)

    2016-12-15

    The aim of this study was to compare the morphology, radiological stage, conspicuity, and computer-assisted detection (CAD) characteristics of colorectal cancers (CRC) detected by computed tomographic colonography (CTC) in screening and symptomatic populations. Two radiologists independently analyzed CTC images from 133 patients diagnosed with CRC in (a) two randomized trials of symptomatic patients (35 patients with 36 tumours) and (b) a screening program using fecal occult blood testing (FOBt; 98 patients with 100 tumours), measuring tumour length, volume, morphology, radiological stage, and subjective conspicuity. A commercial CAD package was applied to both datasets. We compared CTC characteristics between screening and symptomatic populations with multivariable regression. Screen-detected CRC were significantly smaller (mean 3.0 vs 4.3 cm, p < 0.001), of lower volume (median 9.1 vs 23.2 cm{sup 3}, p < 0.001) and more frequently polypoid (34/100, 34 % vs. 5/36, 13.9 %, p = 0.02) than symptomatic CRC. They were of earlier stage than symptomatic tumours (OR = 0.17, 95 %CI 0.07-0.41, p < 0.001), and were judged as significantly less conspicuous (mean conspicuity 54.1/100 vs. 72.8/100, p < 0.001). CAD detection was significantly lower for screen-detected (77.4 %; 95 %CI 67.9-84.7 %) than symptomatic CRC (96.9 %; 95 %CI 83.8-99.4 %, p = 0.02). Screen-detected CRC are significantly smaller, more frequently polypoid, subjectively less conspicuous, and less likely to be identified by CAD than those in symptomatic patients. (orig.)

  14. Empirical study of supervised gene screening

    Directory of Open Access Journals (Sweden)

    Ma Shuangge

    2006-12-01

    Full Text Available Abstract Background Microarray studies provide a way of linking variations of phenotypes with their genetic causations. Constructing predictive models using high dimensional microarray measurements usually consists of three steps: (1 unsupervised gene screening; (2 supervised gene screening; and (3 statistical model building. Supervised gene screening based on marginal gene ranking is commonly used to reduce the number of genes in the model building. Various simple statistics, such as t-statistic or signal to noise ratio, have been used to rank genes in the supervised screening. Despite of its extensive usage, statistical study of supervised gene screening remains scarce. Our study is partly motivated by the differences in gene discovery results caused by using different supervised gene screening methods. Results We investigate concordance and reproducibility of supervised gene screening based on eight commonly used marginal statistics. Concordance is assessed by the relative fractions of overlaps between top ranked genes screened using different marginal statistics. We propose a Bootstrap Reproducibility Index, which measures reproducibility of individual genes under the supervised screening. Empirical studies are based on four public microarray data. We consider the cases where the top 20%, 40% and 60% genes are screened. Conclusion From a gene discovery point of view, the effect of supervised gene screening based on different marginal statistics cannot be ignored. Empirical studies show that (1 genes passed different supervised screenings may be considerably different; (2 concordance may vary, depending on the underlying data structure and percentage of selected genes; (3 evaluated with the Bootstrap Reproducibility Index, genes passed supervised screenings are only moderately reproducible; and (4 concordance cannot be improved by supervised screening based on reproducibility.

  15. Differences in Patient Outcomes of Prevalence, Interval, and Screen-Detected Lung Cancers in the CT Arm of the National Lung Screening Trial.

    Science.gov (United States)

    Schabath, Matthew B; Massion, Pierre P; Thompson, Zachary J; Eschrich, Steven A; Balagurunathan, Yoganand; Goldof, Dmitry; Aberle, Denise R; Gillies, Robert J

    2016-01-01

    Lung cancer screening identifies cancers with heterogeneous behaviors. Some lung cancers will be identified among patients who had prior negative CT screens and upon follow-up scans develop a de novo nodule that was determined to be cancerous. Other lung cancers will be identified among patients who had one or more prior stable positive scans that were not determined to be lung cancer (indeterminate pulmonary nodules), but in follow-up scans was diagnosed with an incidence lung cancer. Using data from the CT arm of the National Lung Screening Trial, this analysis investigated differences in patient characteristics and survival endpoints between prevalence-, interval-, and screen-detected lung cancers, characterized based on sequence of screening results. Lung cancers immediately following a positive baseline (T0), and prior to the T1 screen, formed the prevalence cohort. Interval cancers were diagnosed following a negative screen at any time point prior to the next screening round. Two cohorts of screen-detected lung cancers (SDLC) were identified that had a baseline positive screen that was that was not determined to be lung cancer (i.e., an indeterminate pulmonary nodule), but in follow-up scans was diagnosed with an incidence lung cancer 12 (SDLC1) or 24 (SDLC2) months later. Two other incidence cohorts had screen-detected lung cancers that had baseline negative screen and upon follow-up scans developed a de novo nodule determined to be cancerous at 12 (SDLC3) or 24 (SDLC4) months later. Differences in patient characteristics, progression-free survival (PFS), and overall survival (OS) were assessed. The lung cancer-specific death rate was higher for SDLC3/SDLC4 compared to SDLC1/SDLC2 lung cancers (136.6/1,000 person-years vs. 71.3/1,000 person-years, P < 0.001). Moreover, PFS and OS were significantly lower for SDLC3/SDLC4 compared to SDLC1/SDLC2 (P < 0.004; P < 0.002, respectively). The findings were consistent when stratified by stage and histology

  16. Correlative CT and anatomic study of the sciatic nerve

    Energy Technology Data Exchange (ETDEWEB)

    Pech, P.; Haughton, V.

    1985-05-01

    Sciatica can be caused by numerous processes affecting the sciatic nerve or its components within the pelvis including tumors, infectious diseases, aneurysms, fractures, and endometriosis. The CT diagnosis of these causes of sciatica has not been emphasized. This study identified the course and appearance of the normal sciatic nerve in the pelvis by correlating CT and anatomic slices in cadavers. For purposes of discussion, the sciatic nerve complex is conveniently divided into three parts: presacral, muscular, and ischial. Each part is illustrated here by two cryosections with corresponding CT images.

  17. Use of CT colonography in the English Bowel Cancer Screening Programme

    Science.gov (United States)

    Plumb, Andrew A; Halligan, Steve; Nickerson, Claire; Bassett, Paul; Goddard, Andrew F; Taylor, Stuart A; Patnick, Julietta; Burling, David

    2014-01-01

    Objective To examine use of CT colonography (CTC) in the English Bowel Cancer Screening Programme (BCSP) and investigate detection rates. Design Retrospective analysis of routinely coded BCSP data. Guaiac faecal occult blood test (gFOBt)-positive screenees undergoing CTC from June 2006 to July 2012 as their first-line colonic investigation were included. Abnormalities found at CTC, subsequent polyp, adenoma and cancer detection and positive predictive value (PPV) were calculated. Detection rates were compared with those observed in gFOBt-positive screenees investigated by colonoscopy. Multilevel logistic regression was used to examine factors associated with variable detection. Results 2731 screenees underwent CTC. Colorectal cancer (CRC) or polyps were suspected in 1027 individuals (37.6%; 95% CI 33.8% to 41.4%); 911 of these underwent confirmatory testing. 124 screenees had CRC (4.5%) and 533 had polyps (19.5%), 468 adenomatous (17.1%). Overall detection was 24.1% (95% CI 21.5% to 26.6%) for CRC or polyps and 21.7% (95% CI 19.2% to 24.1%) for CRC or adenoma. Advanced neoplasia was detected in 504 screenees (18.5%; 95% CI 16.1% to 20.8%). PPV for CRC or polyp was 72.1% (95% CI 66.6% to 77.6%). By comparison, 9.0% of 72 817 screenees undergoing colonoscopy had cancer and 50.6% had polyps; advanced neoplasia was detected in 32.7%. CTC detection rates and PPV were higher at centres with experienced radiologists (>1000 examinations) and at high-volume centres (>175 cases/radiologist/annum). Centres using three-dimensional interpretation detected more neoplasia. Conclusions In the BCSP, detection rates after positive gFOBt are lower for CTC than colonoscopy, although populations undergoing the two tests are different. Centres with more experienced radiologists have higher detection and accuracy. Rigorous quality assurance of BCSP radiology is needed. PMID:23955527

  18. Colonography by CT,MRI and PET/CT combined with conventional colonoscopy in colorectal cancer screening and staging

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Colorectal cancer(CRC)remains a leading cancer killer worldwide.But the disease is both curable and preventable at an early stage.Regular CRC cancer screening has been shown to reduce the risk of dying from CRC.However,the importance of large-scale screening is only now starting to be appreciated.This article reviews a variety of imaging procedures available for detecting ulcerative colitis(UC)and Crohn's disease (CD),polyps and CRC in their early stage and also presents details on various screening options.Detecting,staging and re-staging of patients with CRC also require multimodality,multistep imaging approaches.Staging and re-staging with conventional colonoscopy(CC),computer tomography colonography(CTC),magnetic resonance colonography(MRC)and positron emission tomography/computer tomography colonography(PET/CTC)are of paramount importance in determining the most appropriate therapeutic method and in predicting the risk of tumor recurrence and overall prognosis.The advantages and limitations of these modalities are also discussed.

  19. Using CT colonography as a triage technique after a positive faecal occult blood test in colorectal cancer screening

    Science.gov (United States)

    Liedenbaum, M H; van Rijn, A F; de Vries, A H; Dekker, H M; Thomeer, M; van Marrewijk, C J; Hol, L; Dijkgraaf, M G W; Fockens, P; Bossuyt, P M M; Dekker, E; Stoker, J

    2009-01-01

    Objective: The purpose of this study was to evaluate the effectiveness of CT colonography (CTC) as a triage technique in faecal occult blood test (FOBT)-positive screening participants. Methods: Consecutive guaiac (G-FOBT) and immunochemical (I-FOBT) FOBT-positive patients scheduled for colonoscopy underwent CTC with iodine tagging bowel preparation. Each CTC was read independently by two experienced observers. Per patient sensitivity, specificity and positive and negative predictive values (PPV and NPV) were calculated based on double reading with different CTC cut-off lesion sizes using segmental unblinded colonoscopy as the reference standard. The acceptability of the technique to patients was evaluated with questionnaires. Results: 302 FOBT-positive patients were included (54 G-FOBT and 248 I-FOBT). 22 FOBT-positive patients (7%) had a colorectal carcinoma and 211 (70%) had a lesion ⩾6 mm. Participants considered colonoscopy more burdensome than CTC (p<0.05). Using a 6 mm CTC size cut-off, per patient sensitivity for CTC was 91% (95% CI 85% to 91%) and specificity was 69% (95% CI 60% to 89%) for the detection of colonoscopy lesions ⩾6 mm. The PPV of CTC was 87% (95% CI 80% to 93%) and NPV 77% (95% CI 69% to 85%). Using CTC as a triage technique in 100 FOBT-positive patients would mean that colonoscopy could be prevented in 28 patients while missing ⩾10 mm lesions in 2 patients. Conclusion: CTC with limited bowel preparation has reasonable predictive values in an FOBT-positive population and a higher acceptability to patients than colonoscopy. However, due to the high prevalence of clinically relevant lesions in FOBT-positive patients, CTC is unlikely to be an efficient triage technique in a first round FOBT population screening programme. PMID:19625276

  20. Lung cancer probability in patients with CT-detected pulmonary nodules: a prespecified analysis of data from the NELSON trial of low-dose CT screening.

    Science.gov (United States)

    Horeweg, Nanda; van Rosmalen, Joost; Heuvelmans, Marjolein A; van der Aalst, Carlijn M; Vliegenthart, Rozemarijn; Scholten, Ernst Th; ten Haaf, Kevin; Nackaerts, Kristiaan; Lammers, Jan-Willem J; Weenink, Carla; Groen, Harry J; van Ooijen, Peter; de Jong, Pim A; de Bock, Geertruida H; Mali, Willem; de Koning, Harry J; Oudkerk, Matthijs

    2014-11-01

    The main challenge in CT screening for lung cancer is the high prevalence of pulmonary nodules and the relatively low incidence of lung cancer. Management protocols use thresholds for nodule size and growth rate to determine which nodules require additional diagnostic procedures, but these should be based on individuals' probabilities of developing lung cancer. In this prespecified analysis, using data from the NELSON CT screening trial, we aimed to quantify how nodule diameter, volume, and volume doubling time affect the probability of developing lung cancer within 2 years of a CT scan, and to propose and evaluate thresholds for management protocols. Eligible participants in the NELSON trial were those aged 50-75 years, who have smoked 15 cigarettes or more per day for more than 25 years, or ten cigarettes or more for more than 30 years and were still smoking, or had stopped smoking less than 10 years ago. Participants were randomly assigned to low-dose CT screening at increasing intervals, or no screening. We included all participants assigned to the screening group who had attended at least one round of screening, and whose results were available from the national cancer registry database. We calculated lung cancer probabilities, stratified by nodule diameter, volume, and volume doubling time and did logistic regression analysis using diameter, volume, volume doubling time, and multinodularity as potential predictor variables. We assessed management strategies based on nodule threshold characteristics for specificity and sensitivity, and compared them to the American College of Chest Physicians (ACCP) guidelines. The NELSON trial is registered at www.trialregister.nl, number ISRCTN63545820. Volume, volume doubling time, and volumetry-based diameter of 9681 non-calcified nodules detected by CT screening in 7155 participants in the screening group of NELSON were used to quantify lung cancer probability. Lung cancer probability was low in participants with a nodule

  1. Low-dose non-enhanced CT versus full-dose contrast-enhanced CT in integrated PET/CT studies for the diagnosis of uterine cancer recurrence

    Energy Technology Data Exchange (ETDEWEB)

    Kitajima, Kazuhiro [Institute of Biomedical Research and Innovation, Department of PET Diagnosis, Kobe (Japan); Kobe University Graduate School of Medicine, Department of Radiology, Kobe (Japan); Suzuki, Kayo [Institute of Biomedical Research and Innovation, Department of PET Diagnosis, Kobe (Japan); Nakamoto, Yuji [Kyoto University Hospital, Department of Diagnostic Radiology, Kyoto (Japan); Onishi, Yumiko; Sakamoto, Setsu; Sugimura, Kazuro [Kobe University Graduate School of Medicine, Department of Radiology, Kobe (Japan); Senda, Michio [Institute of Biomedical Research and Innovation, Department of Molecular Imaging, Kobe (Japan); Kita, Masato [Kobe City Medical Center General Hospital, Department of Obstetrics and Gynecology, Kobe (Japan)

    2010-08-15

    To evaluate low-dose non-enhanced CT (ldCT) and full-dose contrast-enhanced CT (ceCT) in integrated {sup 18}F-fluorodeoxyglucose (FDG) PET/CT studies for restaging of uterine cancer. A group of 100 women who had undergone treatment for uterine cervical (n=55) or endometrial cancer (n=45) underwent a conventional PET/CT scans with ldCT, and then a ceCT scan. Two observers retrospectively reviewed and interpreted the PET/ldCT and PET/ceCT images in consensus using a three-point grading scale (negative, equivocal, or positive) per patient and per lesion. Final diagnoses were obtained by histopathological examination, or clinical follow-up for at least 6 months. Patient-based analysis showed that the sensitivity, specificity and accuracy of PET/ceCT were 90% (27/30), 97% (68/70) and 95% (95/100), respectively, whereas those of PET/ldCT were 83% (25/30), 94% (66/70) and 91% (91/100), respectively. Sensitivity, specificity and accuracy did not significantly differ between two methods (McNemar test, p=0.48, p=0.48, and p=0.13, respectively). There were 52 sites of lesion recurrence: 12 pelvic lymph node (LN), 11 local recurrence, 8 peritoneum, 7 abdominal LN, 5 lung, 3 supraclavicular LN, 3 liver, 2 mediastinal LN, and 1 muscle and bone. The grading results for the 52 sites of recurrence were: negative 5, equivocal 0 and positive 47 for PET/ceCT, and negative 5, equivocal 4 and positive 43 for PET/ldCT, respectively. Four equivocal regions by PET/ldCT (local recurrence, pelvic LN metastasis, liver metastasis and muscle metastasis) were correctly interpreted as positive by PET/ceCT. PET/ceCT is an accurate imaging modality for the assessment of uterine cancer recurrence. Its use reduces the frequency of equivocal interpretations. (orig.)

  2. Lung cancer screening

    Energy Technology Data Exchange (ETDEWEB)

    Kazerooni, E.A. [Univ. of Michigan Medical Center, Ann Arbor, MI (United States)

    2005-11-15

    Lung cancer screening with CT remains controversial. Lung cancer is the leading cause of cancer death. To date, no screening test has been demonstrated to reduce mortality. Given the large population of adult cigarette smokers and former smokers worldwide, there is a large population at risk for lung cancer. While a lot has been learned from prospective single-arm cohort studies about the feasibility of performing annual CT to screen for lung cancer, many questions have also been raised. While we know that screening for lung cancer with CT detects many small nodules, with up to half the subjects having a positive baseline screen, and up to 75% of subjects having a positive screen at least once if screened annually for 5 years, the great majority of these nodules exhibit benign biologic behavior. The innumerable small nodules detected with screening CT, and diagnostic chest CT in general, present a daily clinical challenge, and result in extensive medical resource utilization and additional radiation exposure. Algorithms for how and when to follow small nodules detected on CT are in evolution. Ongoing studies are designed to determine if lung cancer screening with CT reduces lung cancer mortality. (orig.)

  3. Patient willingness for repeat screening and preference for CT colonography and optical colonoscopy in ACRIN 6664: the National CT Colonography trial

    Directory of Open Access Journals (Sweden)

    Gareen IF

    2015-07-01

    Full Text Available Ilana F Gareen,1,2 Bettina Siewert,3 David J Vanness,4 Benjamin Herman,2 CD Johnson,5 Constantine Gatsonis2,6 1Department of Epidemiology, Brown University School of Public Health, Providence, RI, USA; 2Center for Statistical Sciences, Brown University School of Public Health, Providence, RI, USA; 3Department of Radiology, Beth Israel Deaconess Medical Center, Boston, MA, USA; 4Population Health Sciences, University of Wisconsin, Madison, WI, USA; 5Mayo Clinic, Scottsdale, AZ, USA; 6Department of Biostatistics, Brown University School of Public Health, Providence, RI, USA Background: Current American Cancer Society recommendations for colon cancer screening include optical colonoscopy every 10 years or computed tomography colonography (CTC every 5 years. Bowel preparation (BP is currently required for both screening modalities.Purpose: To compare ACRIN 6664: the National CT Colonography Trial (NCTCT participant experiences with CTC and optical colonoscopy (OC, procedure preference, and willingness to return for each procedure.Materials and methods: Participants from fifteen NCTCT sites, who underwent CTC followed by OC under sedation, were invited to complete questionnaires 2 weeks postexam, asking about procedure preference, physical discomfort, and embarrassment experienced and whether that discomfort and embarrassment was better or worse than expected during BP, CTC, and OC, as well as willingness to return for repeat CTC and OC at different time intervals.Results: A total of 2,310 of 2,600 patients (89% returned their questionnaires. Of patients reporting a preference, 1,058 (46.6% preferred CTC, 569 (25.0% preferred OC, and 626 (27.6% reported no preference. Participant-reported discomfort worse than expected differed significantly between CTC (32.9% and OC (5.0% (P<0.001. About 79.3% were willing to be screened again with CTC in 5 years, and 96.6% with OC in 10 years. Discomfort and embarrassment worse than expected with OC were associated

  4. National Lung Screening Trial (NLST)

    Science.gov (United States)

    The National Lung Screening Trial (NLST), a research study sponsored by the National Cancer Institute that used low-dose helical CT scans or chest X-ray to screen men and women at risk for lung cancer.

  5. Osteoblastic lesion screening with an advanced post-processing package enabling in-plane rib reading in CT-images.

    Science.gov (United States)

    Seuss, Hannes; Dankerl, Peter; Cavallaro, Alexander; Uder, Michael; Hammon, Matthias

    2016-05-20

    To evaluate screening and diagnostic accuracy for the detection of osteoblastic rib lesions using an advanced post-processing package enabling in-plane rib reading in CT-images. We retrospectively assessed the CT-data of 60 consecutive prostate cancer patients by applying dedicated software enabling in-plane rib reading. Reading the conventional multiplanar reconstructions was considered to be the reference standard. To simulate clinical practice, the reader was given 10 s to screen for sclerotic rib lesions in each patient applying both approaches. Afterwards, every rib was evaluated individually with both approaches without a time limit. Sensitivities, specificities, positive/negative predictive values and the time needed for detection were calculated depending on the lesion's size (largest diameter  10 mm). In 53 of 60 patients, all ribs were properly displayed in plane, in five patients ribs were partially displayed correctly, and in two patients none of the ribs were displayed correctly. During the 10-s screening approach all patients with sclerotic rib lesions were correctly identified reading the in-plane images (including the patients without a correct rib segmentation), whereas 14 of 23 patients were correctly identified reading conventional multiplanar images. Overall screening sensitivity, specificity, and positive/negative predictive values were 100/27.0/46.0/100 %, respectively, for in-plane reading and 60.9/100/100/80.4 %, respectively, for multiplanar reading. Overall diagnostic (no time limit) sensitivity, specificity, and positive/negative predictive values of in-plane reading were 97.8/92.8/74.6/99.5 %, respectively. False positive results predominantly occurred for lesions ribs allows reliable detection of osteoblastic lesions for screening purposes. The limited specificity results from false positives predominantly occurring for small lesions.

  6. Occurrence and lung cancer probability of new solid nodules at incidence screening with low-dose CT : analysis of data from the randomised, controlled NELSON trial

    NARCIS (Netherlands)

    Walter, Joan E.; Heuvelmans, Marjolein A.; de Jong, Pim A.; Vliegenthart, Rozemarijn; van Ooijen, Peter M. A.; Peters, Robin B.; ten Haaf, Kevin; Yousaf-Khan, Uraujh; van der Aalst, Carlijn M.; de Bock, Geertruida H.; Mali, Willem; Groen, Harry J. M.; de Koning, Harry J.; Oudkerk, Matthijs

    2016-01-01

    Background US guidelines now recommend lung cancer screening with low-dose CT for high-risk individuals. Reports of new nodules after baseline screening have been scarce and are inconsistent because of differences in definitions used. We aimed to identify the occurrence of new solid nodules and thei

  7. Occurrence and lung cancer probability of new solid nodules at incidence screening with low-dose CT : analysis of data from the randomised, controlled NELSON trial

    NARCIS (Netherlands)

    Walter, Joan E.; Heuvelmans, Marjolein A.; de Jong, Pim A.; Vliegenthart, Rozemarijn; van Ooijen, Peter M. A.; Peters, Robin B.; ten Haaf, Kevin; Yousaf-Khan, Uraujh; van der Aalst, Carlijn M.; de Bock, Geertruida H.; Mali, Willem; Groen, Harry J. M.; de Koning, Harry J.; Oudkerk, Matthijs

    2016-01-01

    BACKGROUND: US guidelines now recommend lung cancer screening with low-dose CT for high-risk individuals. Reports of new nodules after baseline screening have been scarce and are inconsistent because of differences in definitions used. We aimed to identify the occurrence of new solid nodules and the

  8. Occurrence and lung cancer probability of new solid nodules at incidence screening with low-dose CT : analysis of data from the randomised, controlled NELSON trial

    NARCIS (Netherlands)

    Walter, Joan E.; Heuvelmans, Marjolein A.; de Jong, Pim A.; Vliegenthart, Rozemarijn; van Ooijen, Peter M A; Peters, Robin B.; ten Haaf, Kevin; Yousaf-Khan, Uraujh; van der Aalst, Carlijn M.; de Bock, Geertruida H.; Mali, Willem P Th M; Groen, Harry J M; de Koning, Harry J.; Oudkerk, Matthijs

    BACKGROUND: US guidelines now recommend lung cancer screening with low-dose CT for high-risk individuals. Reports of new nodules after baseline screening have been scarce and are inconsistent because of differences in definitions used. We aimed to identify the occurrence of new solid nodules and

  9. Determination of liquid's molecular interference function based on X-ray diffraction and dual-energy CT in security screening.

    Science.gov (United States)

    Zhang, Li; YangDai, Tianyi

    2016-08-01

    A method for deriving the molecular interference function (MIF) of an unknown liquid for security screening is presented. Based on the effective atomic number reconstructed from dual-energy computed tomography (CT), equivalent molecular formula of the liquid is estimated. After a series of optimizations, the MIF and a new effective atomic number are finally obtained from the X-ray diffraction (XRD) profile. The proposed method generates more accurate results with less sensitivity to the noise and data deficiency of the XRD profile.

  10. Potential role of {sup 68}Ga-DOTATOC PET/CT in screening for pancreatic neuroendocrine tumour in patients with von Hippel-Lindau disease

    Energy Technology Data Exchange (ETDEWEB)

    Prasad, Vikas; Brenner, Winfried [Charite Universitaetsmedizin Berlin, Department of Nuclear Medicine, Campus Virchow-Klinikum, Berlin (Germany); Tiling, Nikolaus; Ploeckinger, Ursula [Charite Universitaetsmedizin Berlin, Interdisziplinaeren Stoffwechsel-Centrum, Campus Virchow Klinikum, Berlin (Germany); Denecke, Timm [Charite Universitaetsmedizin Berlin, Department of Radiology, Berlin (Germany)

    2016-10-15

    Neuroendocrine tumours of the pancreas (pNET) are observed in 8 - 17 % of patients with von Hippel-Lindau disease (vHLD), and 11 - 20 % of these patients develop metastatic disease. MRI and CT have a very high resolution; however, their sensitivity and specificity for the detection of pNET amongst cystic lesions in the pancreas of vHLD patients are generally considered insufficient. In contrast, {sup 68}Ga-DOTATOC PET/CT demonstrates a high sensitivity for the diagnosis and staging of neuroendocrine tumours. In this study we investigated the potential role of {sup 68}Ga-DOTATOC PET/CT in screening of patients with vHLD. {sup 68}Ga-DOTATOC PET/three-phase contrast-enhanced CT was performed according to guidelines in all consecutive vHLD patients between January 2012 and November 2015. All patients underwent additional MRI imaging of the abdomen, spine, and head. Chromogranin A (CgA) was determined at the time of the PET/CT examination. A lesion seen on {sup 68}Ga-DOTATOC PET in the pancreas was defined as positive if the uptake was visually higher than in the surrounding tissues. Lesions were quantified using maximum SUV. Overall, 20 patients (8 men, 12 women; mean age 44.7 ± 11.1 years) were prospectively examined. Genetically, 12 patients had type 1 vHLD and 8 had type 2 vHLD. {sup 68}Ga-DOTATOC PET/CT detected more pNET than morphological imaging (CT or MRI): 11 patients (55 %; 8 type 1, 3 type 2) vs. 9 patients (45 %; 6 type 1, 3 type 2). The concentration of CgA was mildly elevated in 2 of 11 patients with pNET. The mean SUVmax of the pancreatic lesions was 18.9 ± 21.9 (range 5.0 - 65.6). Four patients (36.4 %) had multiple pNETs. The mean size of the lesions on CT and/or MRI was 10.4 ± 8.3 mm (range 4 - 38 mm), and 41.1 % were larger than 10 mm. In addition, somatostatin receptor-positive cerebellar and spinal haemangioblastomas were detected in three patients (SUVmax 2.1 - 10.1). One patient presented with a solitary somatostatin receptor-positive lymph

  11. Quantification of growth patterns of screen-detected lung cancers : The NELSON study

    NARCIS (Netherlands)

    Heuvelmans, Marjolein A.; Vliegenthart, Rozemarijn; de Koning, Harry J.; Groen, Harry J M; van Putten, Michel J A M; Yousaf-Khan, Uraujh; Weenink, Carla; Nackaerts, Kristiaan; de Jong, Pim A.; Oudkerk, Matthijs

    Objectives Although exponential growth is assumed for lung cancer, this has never been quantified in vivo. Aim of this study was to evaluate and quantify growth patterns of lung cancers detected in the Dutch-Belgian low-dose computed tomography (CT) lung cancer screening trial (NELSON), in order to

  12. Quantification of growth patterns of screen-detected lung cancers : The NELSON study

    NARCIS (Netherlands)

    Heuvelmans, Marjolein A.; Vliegenthart, Rozemarijn; de Koning, Harry J.; Groen, Harry J M; van Putten, Michel J A M; Yousaf-Khan, Uraujh; Weenink, Carla; Nackaerts, Kristiaan; de Jong, Pim A.|info:eu-repo/dai/nl/287955672; Oudkerk, Matthijs

    2017-01-01

    Objectives Although exponential growth is assumed for lung cancer, this has never been quantified in vivo. Aim of this study was to evaluate and quantify growth patterns of lung cancers detected in the Dutch-Belgian low-dose computed tomography (CT) lung cancer screening trial (NELSON), in order to

  13. Small pulmonary nodules in baseline and incidence screening rounds of low-dose CT lung cancer screening

    NARCIS (Netherlands)

    Walter, Joan E; Heuvelmans, Marjolein A; Oudkerk, Matthijs

    Currently, lung cancer screening by low-dose computed tomography (LDCT) is widely recommended for high-risk individuals by US guidelines, but there still is an ongoing debate concerning respective recommendations for European countries. Nevertheless, the available data regarding pulmonary nodules

  14. Screening in asymptomatic SDHx mutation carriers: added value of {sup 18}F-FDG PET/CT at initial diagnosis and 1-year follow-up

    Energy Technology Data Exchange (ETDEWEB)

    Lepoutre-Lussey, C.; Deandreis, D.; Berdelou, A.; Nascimento, C.; Lumbroso, J.; Schlumberger, M.; Baudin, E.; Leboulleux, S. [Gustave Roussy Institut, Universite Paris-Sud, Department of Nuclear Medicine and Endocrine Oncology, Villejuif (France); Caramella, C.; Bidault, F.; Deschamps, F. [Gustave Roussy Institut, Department of Radiology, Villejuif (France); Al Ghuzlan, A. [Gustave Roussy Institut, Department of Medical Biology and Pathology, Villejuif (France); Hartl, D.; Dumont, F. [Gustave Roussy Institut, Department of Surgery, Villejuif (France); Borget, I. [Gustave Roussy Institut, Department of Biostatistic and Epidemiology, Villejuif (France); Paris-Sud University, Villejuif (France); Gimenez-Roqueplo, A.P. [Assistance Publique-Hopitaux de Paris, Hopital Europeen Georges Pompidou, Department of Genetics, Paris (France); Paris Descartes University, Faculty of Medicine, Paris (France); Guillaud Bataille, M. [Gustave Roussy Institut, Department of Genetics, Villejuif (France)

    2015-05-01

    Specific recommendations on screening modalities for paraganglioma (PGL) and phaeochromocytoma (PCC) in asymptomatic SDHx mutation carriers (relatives) are still lacking. We evaluated the added value of {sup 18}F-FDG PET/CT in comparison with morphological imaging at initial diagnosis and 1 year of follow-up in this population. The study included 30 consecutive relatives with a proven SDHx mutation who were investigated by {sup 18}F-FDG PET/CT, gadolinium-enhanced magnetic resonance angiography of the head and neck, thoracic/abdominal/pelvic (TAP) contrast-enhanced CT and/or TAP MRI. {sup 123}I-MIBG scintigraphy was performed in 20 subjects and somatostatin receptor scintigraphy (SRS) in 20 subjects. The gold standard was based on pathology or a composite endpoint as defined by any other positive imaging method and persistent tumour on follow-up. Images were considered as false-positive when the lesions were not detected by another imaging method or not confirmed at 1 year. At initial work-up, an imaging abnormality was found in eight subjects (27 %). The final diagnosis was true-positive in five subjects (two with abdominal PGL, one with PCC and two with neck PGL) and false-positives in the other three subjects (detected with {sup 18}F-FDG PET/CT in two and TAP MRI in one). At 1 year, an imaging abnormality was found in three subjects of which one was an 8-mm carotid body PGL in a patient with SDHD mutation and two were considered false-positive. The tumour detection rate was 100 % for {sup 18}F-FDG PET/CT and conventional imaging, 80 % for SRS and 60 % for {sup 123}I-MIBG scintigraphy. Overall, disease was detected in 4 % of the subjects at the 1-year follow-up. {sup 18}F-FDG PET/CT demonstrated excellent sensitivity but intermediate specificity justifying combined modality imaging in these patients. Given the slow progression of the disease, if {sup 18}F-FDG PET/CT and MRI are normal at baseline, the second imaging work-up should be delayed and an examination

  15. Internal noise in channelized Hotelling observer (CHO) study of detectability index-differential phase contrast CT vs. conventional CT

    Science.gov (United States)

    Tang, Xiangyang; Yang, Yi

    2014-03-01

    The channelized Hotelling observer (CHO) model, wherein internal noise plays an important role to account for the psychophysiological uncertainty in human's visual perception, has found extensive applications in the assessment of image quality in nuclear medicine, mammography and conventional CT. Recently, we extended its application to investigating the detectability index of differential phase contrast (DPC) CT-an emerging CT technology with the potential of increasing the capability in soft tissue differentiation. We found that the quantitative determination of internal noise in the CHO study of DPC-CT's detectability index should differ from that in the conventional CT. It is believed that the root cause of such a difference lies in the distinct noise spectra between the DPC-CT and conventional CT. In this paper, we present the preliminary results and investigate the adequate strategies to quantitatively determine the internal noise of CHO model for its application in the assessment of image quality in DPC-CT and its comparison with that of the conventional CT.

  16. Patient willingness for repeat screening and preference for CT colonography and optical colonoscopy in ACRIN 6664: the National CT Colonography trial.

    Science.gov (United States)

    Gareen, Ilana F; Siewert, Bettina; Vanness, David J; Herman, Benjamin; Johnson, C D; Gatsonis, Constantine

    2015-01-01

    Current American Cancer Society recommendations for colon cancer screening include optical colonoscopy every 10 years or computed tomography colonography (CTC) every 5 years. Bowel preparation (BP) is currently required for both screening modalities. To compare ACRIN 6664: the National CT Colonography Trial (NCTCT) participant experiences with CTC and optical colonoscopy (OC), procedure preference, and willingness to return for each procedure. Participants from fifteen NCTCT sites, who underwent CTC followed by OC under sedation, were invited to complete questionnaires 2 weeks postexam, asking about procedure preference, physical discomfort, and embarrassment experienced and whether that discomfort and embarrassment was better or worse than expected during BP, CTC, and OC, as well as willingness to return for repeat CTC and OC at different time intervals. A total of 2,310 of 2,600 patients (89%) returned their questionnaires. Of patients reporting a preference, 1,058 (46.6%) preferred CTC, 569 (25.0%) preferred OC, and 626 (27.6%) reported no preference. Participant-reported discomfort worse than expected differed significantly between CTC (32.9%) and OC (5.0%) (Pembarrassment worse than expected with OC were associated with increased intention to adhere with CTC in the future. Conversely, embarrassment experienced during CTC and discomfort worse than expected on CTC were associated with increased intention to adhere with OC in the future. While a larger proportion of participants indicated that they preferred CTC to OC, willingness to undergo repeat CTC compared to OC was limited by unanticipated exam discomfort and embarrassment and CTC's shorter screening interval.

  17. Lung cancer screening and video-assisted thoracic surgery

    DEFF Research Database (Denmark)

    Petersen, René Horsleben; Hansen, Henrik Jessen; Dirksen, Asger

    2012-01-01

    The objective of this study is to report the impact of computed tomography (CT) screening on the use of Video-Assisted Thoracic Surgery (VATS) in a randomized screening trial.......The objective of this study is to report the impact of computed tomography (CT) screening on the use of Video-Assisted Thoracic Surgery (VATS) in a randomized screening trial....

  18. More than lung cancer: Automated analysis of low-dose screening CT scans

    NARCIS (Netherlands)

    Mets, O.M.

    2012-01-01

    Smoking is a major health care problem and is projected to cause over 8 million deaths per year worldwide in the coming decades. To reduce lung cancer mortality in heavy smokers, several randomized screening trials were initiated in the past years using screening with low-dose Computed Tomography

  19. Helical CT study of cerebral perfusion and related hemodynamic parameters

    Science.gov (United States)

    Cenic, Aleksa; Lee, Ting-Yim; Craen, Rosemary A.; Gelb, Adrian W.

    1997-05-01

    A convenient method for assessing cerebral perfusion and related functional parameters has been developed using a third generation slip-ring CT scanner. Dynamic contrast- enhanced scanning at the same level was employed to image the cerebral circulation at the rate of 1 image per second. Using data acquired with this non-helical mode of scanning, we have developed a method for the simultaneous in-vivo determination of cerebral blood flow (CBF), cerebral blood volume (CBV), and mean transit time (MTT). These measurements are given in the same physiological units as positron emission tomography. In order to obtain accurate measurements of these parameters, methods were also developed to correct for recirculation and partial volume averaging in imaging small blood vessels. We have used 6 New Zealand white rabbits in our studies. For each rabbit, up to 3 CT measurements of CBF, CBV, and MTT were made at normocapnia under isoflurane anesthesia. Coronal sections through the brain were imaged while simultaneously imaging either a brain artery or the ear artery. Images were acquired for 1 minute as Isovue 300 was injected intravenously. In the acquired CT images, regions of interest in brain parenchyma and an artery were drawn. For each region of interest, the mean CT number in pre-contrast images was subtracted from the mean in post-contrast images to calculate the contrast concentration curves for the brain regions Q(t) and the arterial region Ca(t). Using a robust deconvolution method, the MTT was determined. CBV was then determined from the ratio of the areas of Q(t) and Ca(t). Finally, CBF was calculated from the Central Volume Principle. The mean regional CBF, CBV and MTT values were 73.3 +/- 5.1 ml/min/100g, 1.93 +/- 0.12 ml/100g and 1.80 +/- 0.18 s respectively. IN order to validate our CT CBF measurements, we also measured CBF using the well- established technique of microspheres with each CT study. The feasibility of our CT method to measure CBF accurately was

  20. Diagnostic work-up of pulmonary nodules. Management of pulmonary nodules detected with low-dose CT screening; Abklaerung von Lungenrundherden. Management durch Frueherkennungsuntersuchungen detektierter pulmonaler Rundherde

    Energy Technology Data Exchange (ETDEWEB)

    Wormanns, D. [Evangelische Lungenklinik Berlin, Berlin (Germany)

    2016-09-15

    Pulmonary nodules are the most frequent pathological finding in low-dose computed tomography (CT) scanning for early detection of lung cancer. Early stages of lung cancer are often manifested as pulmonary nodules; however, the very commonly occurring small nodules are predominantly benign. These benign nodules are responsible for the high percentage of false positive test results in screening studies. Appropriate diagnostic algorithms are necessary to reduce false positive screening results and to improve the specificity of lung cancer screening. Such algorithms are based on some of the basic principles comprehensively described in this article. Firstly, the diameter of nodules allows a differentiation between large (>8 mm) probably malignant and small (<8 mm) probably benign nodules. Secondly, some morphological features of pulmonary nodules in CT can prove their benign nature. Thirdly, growth of small nodules is the best non-invasive predictor of malignancy and is utilized as a trigger for further diagnostic work-up. Non-invasive testing using positron emission tomography (PET) and contrast enhancement as well as invasive diagnostic tests (e.g. various procedures for cytological and histological diagnostics) are briefly described in this article. Different nodule morphology using CT (e.g. solid and semisolid nodules) is associated with different biological behavior and different algorithms for follow-up are required. Currently, no obligatory algorithm is available in German-speaking countries for the management of pulmonary nodules, which reflects the current state of knowledge. The main features of some international and American recommendations are briefly presented in this article from which conclusions for the daily clinical use are derived. (orig.) [German] Lungenrundherde sind die haeufigsten pathologischen Befunde bei Untersuchungen mit der Niedrigdosis-CT zur Lungenkrebsfrueherkennung. Fruehstadien des Lungenkarzinoms manifestieren sich meist als Rundherd

  1. Dynamic CT head phantom for perfusion and angiography studies

    Science.gov (United States)

    Russell, K.; Blazeski, A.; Dannecker, K.; Lee, Q. Y.; Holscher, C.; Donahue, C.; van Kampen, W.

    2010-03-01

    Contrast imaging is a compelling enhancement for the portable, flat panel-based brain CT scanner currently under development at Xoran. Due to the relative low temporal resolution of flat panel detectors, enabling tomographic imaging on such platform requires optimizing the imaging and injection protocols. A dynamic CT head phantom was designed to facilitate this task. The Dynamic Perfusion and Angiography Model (PAM), mimics tissue attenuation in CT images, provides physiological timing for angiography and perfusion studies, and moves fluid with properties similar to those of blood. The design consists of an arterial system, which contains bifurcating vessels that feed into perfusion chambers, mimicking blood flow through capillaries and smaller vessels, and a venous system, which is symmetrical to the arterial side and drains the perfusion chambers. The variation of geometry and flow rate in the phantom provides the physiological total time that fluid spends in the head, and the difference in material densities correlates to CT numbers for biological tissues. This paper discusses the design of Dynamic PAM and shows experimental results demonstrating its ability to realistically simulate blood flow. Results of dynamic imaging studies of the phantom are also presented.

  2. Visualizing typical features of breast fibroadenomas using phase-contrast CT: an ex-vivo study.

    Directory of Open Access Journals (Sweden)

    Susanne Grandl

    Full Text Available BACKGROUND: Fibroadenoma is the most common benign solid breast lesion type and a very common cause for histologic assessment. To justify a conservative therapy, a highly specific discrimination between fibroadenomas and other breast lesions is crucial. Phase-contrast imaging offers improved soft-tissue contrast and differentiability of fine structures combined with the potential of 3-dimensional imaging. In this study we assessed the potential of grating-based phase-contrast CT imaging for visualizing diagnostically relevant features of fibroadenomas. MATERIALS AND METHODS: Grating-based phase-contrast CT was performed on six ex-vivo formalin-fixed breast specimens containing a fibroadenoma and three samples containing benign changes that resemble fibroadenomas using Talbot Lau interferometry and a polychromatic X-ray source. Phase-contrast and simultaneously acquired absorption-based 3D-datasets were manually matched with corresponding histological slices. The visibility of diagnostically valuable features was assessed in comparison with histology as the gold-standard. RESULTS: In all cases, matching of grating-based phase-contrast CT images and histology was successfully completed. Grating-based phase-contrast CT showed greatly improved differentiation of fine structures and provided accurate depiction of strands of fibrous tissue within the fibroadenomas as well as of the diagnostically valuable dilated, branched ductuli of the fibroadenomas. A clear demarcation of tumor boundaries in all cases was provided by phase- but not absorption-contrast CT. CONCLUSIONS: Pending successful translation of the technology to a clinical setting and considerable reduction of the required dose, the data presented here suggest that grating-based phase-contrast CT may be used as a supplementary non-invasive diagnostic tool in breast diagnostics. Phase-contrast CT may thus contribute to the reduction of false positive findings and reduce the recall and core

  3. Reliable categorisation of visual scoring of coronary artery calcification on low-dose CT for lung cancer screening: validation with the standard Agatston score

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Yi-Luan; Wu, Fu-Zong; Wang, Yen-Chi [Kaohsiung Veterans General Hospital, Department of Radiology, Kaohsiung 813 (China); National Yang Ming University, Faculty of Medicine, School of Medicine, Taipei (China); Ju, Yu-Jeng [National Taiwan University, Department of Psychology, Taipei (China); Mar, Guang-Yuan [Kaohsiung Veterans General Hospital, Division of Cardiology, Department of Medicine, Kaohsiung 813 (China); Chuo, Chiung-Chen [Kaohsiung Veterans General Hospital, Department of Radiology, Kaohsiung 813 (China); Lin, Huey-Shyan [Fooyin University, School of Nursing, Kaohsiung (China); Wu, Ming-Ting [Kaohsiung Veterans General Hospital, Department of Radiology, Kaohsiung 813 (China); National Yang Ming University, Faculty of Medicine, School of Medicine, Taipei (China); National Yang Ming University, Institute of Clinical Medicine, Taipei (China)

    2013-05-15

    To validate the reliability of the visual coronary artery calcification score (VCACS) on low-dose CT (LDCT) for concurrent screening of CAC and lung cancer. We enrolled 401 subjects receiving LDCT for lung cancer screening and ECG-gated CT for the Agatston score (AS). LDCT was reconstructed with 3- and 5-mm slice thickness (LDCT-3mm and LDCT-5mm respectively) for VCACS to obtain VCACS-3mm and VCACS-5mm respectively. After a training session comprising 32 cases, two observers performed four-scale VCACS (absent, mild, moderate, severe) of 369 data sets independently, the results were compared with four-scale AS (0, 1-100, 101-400, >400). CACs were present in 39.6 % (146/369) of subjects. The sensitivity of VCACS-3mm was higher than for VCACS-5mm (83.6 % versus 74.0 %). The median of AS of the 24 false-negative cases in VCACS-3mm was 2.3 (range 1.1-21.1). The false-negative rate for detecting AS {>=} 10 on LDCT-3mm was 1.9 %. VCACS-3mm had higher concordance with AS than VCACS-5mm (k = 0.813 versus k = 0.685). An extended test of VCACS-3mm for four junior observers showed high inter-observer reliability (intra-class correlation = 0.90) and good concordance with AS (k = 0.662-0.747). This study validated the reliability of VCACS on LDCT for lung cancer screening and showed that LDCT-3mm was more feasible than LDCT-5mm for CAD risk stratification. (orig.)

  4. Burden of waiting for surveillance CT colonography in patients with screen-detected 6-9 mm polyps

    Energy Technology Data Exchange (ETDEWEB)

    Tutein Nolthenius, Charlotte J. [University of Amsterdam, Department of Radiology, Academic Medical Center, PO Box 22700, Amsterdam (Netherlands); Onze Lieve Vrouwe Gasthuis, Department of Radiology, Amsterdam (Netherlands); Boellaard, Thierry N.; Nio, C.Y.; Bipat, Shandra; Stoker, Jaap [University of Amsterdam, Department of Radiology, Academic Medical Center, PO Box 22700, Amsterdam (Netherlands); Haan, Margriet C. de [Meander Medical Center, Department of Radiology, Amersfoort (Netherlands); Thomeer, Maarten G.J. [Erasmus University Medical Center, Department of Radiology, Rotterdam (Netherlands); Montauban van Swijndregt, Alexander D. [Onze Lieve Vrouwe Gasthuis, Department of Radiology, Amsterdam (Netherlands); Essink-Bot, Marie-Louise [University of Amsterdam, Public Health, Academic Medical Center, PO Box 22700, Amsterdam (Netherlands); Kuipers, Ernst J. [Erasmus University Medical Center, Gastroenterology and Hepatology, Rotterdam (Netherlands); Erasmus University Medical Center, Internal medicine, Rotterdam (Netherlands); Dekker, Evelien [University of Amsterdam, Gastroenterology and Hepatology, Academic Medical Center, PO Box 22700, Amsterdam (Netherlands)

    2016-11-15

    We assessed the burden of waiting for surveillance CT colonography (CTC) performed in patients having 6-9 mm colorectal polyps on primary screening CTC. Additionally, we compared the burden of primary and surveillance CTC. In an invitational population-based CTC screening trial, 101 persons were diagnosed with <3 polyps 6-9 mm, for which surveillance CTC after 3 years was advised. Validated questionnaires regarding expected and perceived burden (5-point Likert scales) were completed before and after index and surveillance CTC, also including items on burden of waiting for surveillance CTC. McNemar's test was used for comparison after dichotomization. Seventy-eight (77 %) of 101 invitees underwent surveillance CTC, of which 66 (85 %) completed the expected and 62 (79 %) the perceived burden questionnaire. The majority of participants (73 %) reported the experience of waiting for surveillance CTC as 'never' or 'only sometimes' burdensome. There was almost no difference in expected and perceived burden between surveillance and index CTC. Waiting for the results after the procedure was significantly more burdensome for surveillance CTC than for index CTC (23 vs. 8 %; p = 0.012). Waiting for surveillance CTC after primary CTC screening caused little or no burden for surveillance participants. In general, the burden of surveillance and index CTC were comparable. (orig.)

  5. CT screening for lung cancer: Frequency of enlarged adrenal glands identified in baseline and annual repeat rounds

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Minxia [Icahn School of Medicine at Mount Sinai, Department of Radiology, New York, NY (United States); Capital Medical University, Department of Diagnostic Ultrasound, Beijing Tongren Hospital, Beijing (China); Yip, Rowena; Yankelevitz, David Y.; Henschke, Claudia I. [Icahn School of Medicine at Mount Sinai, Department of Radiology, New York, NY (United States)

    2016-12-15

    To determine the frequency of adrenal enlargement of participants in a CT-screening program for lung cancer and demonstrate the progression during follow-up, separately for baseline and annual repeat rounds. HIPAA-compliant informed consent was obtained in 4,776 participants. The adrenal gland was defined as enlarged if it measured ≥6 mm at its largest diameter. Logistic regression analyses were performed. At baseline, 202 (4 %) of 4,776 participants had adrenal enlargement. Significant factors were age (OR = 1.4, 95 % CI: 1.2-1.7) and current smoker (OR = 1.8, 95 % CI: 1.3-2.4). Follow-up 7-18 months after baseline for 133 cases with adrenal enlargement <40 mm showed it decreased or was stable in 85 (64 %), and increased by <10 mm in 48 (36 %). Five (0.04 %) cases of adrenal enlargement were newly identified, none increased beyond 40 mm on follow-up. Adrenal enlargement was a significant predictor of a subsequent diagnosis of lung cancer (OR = 2.0, 95 % CI: 1.2-3.4). Participants with adrenal enlargement <40 mm identified at baseline and on repeat screening could be reasonably assessed on subsequent annual screening. Adrenal enlargement increased with increasing pack-years of smoking. Adrenal enlargement was an independent predictor of a subsequent diagnosis of lung cancer. (orig.)

  6. Dynamic CT study of normal-pressure hydrocephalus

    Energy Technology Data Exchange (ETDEWEB)

    Tamaki, Norihiko; Kojima, Noriaki; Shirakuni, Takayuki; Matsumoto, Satoshi

    1984-08-01

    A dynamic CT study was performed in 14 patients with presumed normal-pressure hydrocephalus, of which diagnosis had been made by clinical symptomatology, CT findings, the results of the continuous monitoring of intracranial pressure, and CT cisternographic findings. It is demonstrated by serial CT scans that the cerebral arteries and arterioles were initially filled with contrast media, which were followed by the symmetrical and homogeneous staining of the cortical gray matter and basal ganglia, the diencephalia, and then the white matter. The venous system was stained in the late phase. The contrast media was finally cleared out from the intracranial space. Thus, the staining of the cerebral vessels and brain parenchym showed a uniform pattern in all cases. Functional CT images revealed that the patients with normal-pressure hydrocephalus who responded well to the shunt procedure had areas of prolonged mean circulation time scattered diffusely not only in the paraventricular structures, but also in the cortical gray matter of all the cerebral hemispheres. Following the shunt procedure, the hemodynamic conditions improved in almost all the areas mentioned above, but especially in the frontal and temporal gray matters and the paraventricular structures. In the patients who did not benefit from the shunt operation, however, there was no special abnormality of hemodynamic distribution. The analysis of the mean circulation time in the region of interest demonstrated that a significant improvement in cerebral hemodynamics was noted in the regions of the frontal and temporal gray matters, the periventricular white matter, and the caudate nucleus in patients who benefitted from the shunt operation. In patients who did not improve after the ventriculo-peritoneal shunt, however, there was no statistically significant difference between pre- and post-shunt mean circulation times. (J.P.N.).

  7. TU-EF-204-08: Dose Efficiency of Added Beam-Shaping Filter with Varied Attenuation Levels in Lung-Cancer Screening CT

    Energy Technology Data Exchange (ETDEWEB)

    Ma, C; Yu, L; Vrieze, T; Leng, S; Fletcher, J; McCollough, C [Mayo Clinic, Rochester, MN (United States)

    2015-06-15

    Purpose: Added filtration such as tin filter has the potential to improve dose efficiency of x-ray beam in lung-cancer screening CT. However, dose efficiency with added beam filtration is highly dependent on patient attenuation level. In this phantom study, we evaluated the image quality at different tube voltages with and without added tin filter when attenuation level varies. Methods: A 30 x 20 cm anthropomorphic thorax phantom with three added extension rings were used to simulate small (S), medium (M), large (L), and extra-large (XL) adult patients. These phantoms were scanned on a 192-slice CT scanner (Force, Siemens) at 100 and 120kV without tin filtration, and 100 and 150 kV with tin filtration (100Sn and 150Sn), at multiple dose levels at each kV. Images were reconstructed using iterative reconstruction (ADMIRE, Siemens). Radiation dose was measured with a 0.6 cc ion chamber in the middle and peripheral areas of the phantom. Image quality was assessed using mean image noise at uniform areas in the central region and lung. Radiation dose that is required for each kV to match the noise in a routine lung-cancer CT screening technique (120kV, 25 quality reference mAs) was calculated. Results: At each of the four phantom sizes, 100Sn had the lowest noise in both soft tissue and lung. Compared with 120 kV, 100Sn saved 39%–60% dose for the same noise, depending on phantom size. For the XL phantom (50 by 40 cm), 150Sn provided images with the least beam-hardening artifact in peripheral region. Conclusion: For thoracic CT, added tin filtration can provide considerable dose reduction compared with 120 kV. 100Sn provides better dose efficiencies for all phantom sizes, while 150Sn provides better image quality in peripheral region for extra-large patients. Drs.Joel G. Fletcher and Cynthia H. McCollough receive research support from Siemens Healthcare.

  8. Combined use of positron emission tomography and volume doubling time in lung cancer screening with low-dose CT scanning

    DEFF Research Database (Denmark)

    Ashraf, H; Dirksen, A; Jakobsen, Annika Loft

    2011-01-01

    In lung cancer screening the ability to distinguish malignant from benign nodules is a key issue. This study evaluates the ability of positron emission tomography (PET) and volume doubling time (VDT) to discriminate between benign and malignant nodules....

  9. Blinded and uniform cause of death verification in a lung cancer CT screening trial

    NARCIS (Netherlands)

    Horeweg, N.; van Klaveren, R. J.; Groen, H. J. M.; Lammers, J. -W. J.; Weenink, C.; Nackaerts, K.; Mali, W.; Oudkerk, M.; de Koning, H. J.

    2012-01-01

    Disease-specific mortality is the final outcome of a lung cancer screening trial, therefore cause of death verification is crucial. The use of death certificates for this purpose is debated because of bias, inaccurate completion and incorrect ante mortem diagnoses. A cause of death evaluation proces

  10. Combined use of positron emission tomography and volume doubling time in lung cancer screening with low-dose CT scanning

    DEFF Research Database (Denmark)

    Ashraf, H; Dirksen, A; Jakobsen, Annika Loft

    2011-01-01

    In lung cancer screening the ability to distinguish malignant from benign nodules is a key issue. This study evaluates the ability of positron emission tomography (PET) and volume doubling time (VDT) to discriminate between benign and malignant nodules.......In lung cancer screening the ability to distinguish malignant from benign nodules is a key issue. This study evaluates the ability of positron emission tomography (PET) and volume doubling time (VDT) to discriminate between benign and malignant nodules....

  11. Evaluation of periventricular radiolucency in hydrocephalus by dynamic CT studies

    Energy Technology Data Exchange (ETDEWEB)

    Nakano, Hideki; Bandou, Kuniaki; Miyaoka, Makoto (Fujisawa City Hospital, Kanagawa (Japan))

    1994-06-01

    The association of periventricular radiolucency (PVL) in normal pressure hydrocephalus (NPH) on CT scan is a common finding. However, it is difficult to differentiate NPH from atrophy or infarctions in which shunt surgery does not reverse these conditions. To distinguish NPH from these, we examined PVL by means of dynamic CT (DCT) studies. We investigated 12 elderly patients presenting with gait disturbance, urinary incontinence and mental dysfunction who had both enlarged lateral ventricles and PVL. All patients had laboratory investigations, including radioisotope and CT cisternography and Xenon CBF studies. Nine patients were shunted because of abnormal CSF dynamics. Varying degrees of clinical improvement after surgery were observed in 6 cases. A difference of arrival time (AT) between PVL and thalamus obtained from time-density-curve was calculated in each patient. The AT difference was 6.2[+-]1.5 sec. in the shunt-effective group, and 1.4[+-]1.3 sec. in both, the shunt in effective and ineligible group, this was highly significant (p<0.01). We also measured peak time (PT) in PVL, of the thalamus and anterior cerebral artery, but no significant correlation was obtained. An AT difference between PVL and thalamus obtained from DCT studies is a clinically useful diagnostic tool for the evaluation of NPH. (author).

  12. Ground-Glass Opacity Lung Nodules in the Era of Lung Cancer CT Screening

    DEFF Research Database (Denmark)

    Pedersen, Jesper Holst; Saghir, Zaigham; Winkler Wille, Mathilde Marie

    2016-01-01

    The advent of computed tomography screening for lung cancer will increase the incidence of ground-glass opacity (GGO) nodules detected and referred for diagnostic evaluation and management. GGO nodules remain a diagnostic challenge; therefore, a more systematic approach is necessary to ensure......, the National Comprehensive Cancer Network, and the British Thoracic Society. In addition, we discuss the management and follow-up of GGO nodules in the light of experience from screening trials. Minimally invasive tissue biopsies and the marking of GGO nodules for surgery are new and rapidly developing fields...... that will yield improvements in both diagnosis and treatment. The standard-of-care surgical treatment of early lung cancer is still minimally invasive lobectomy with systematic lymph node dissection. However, recent research has shown that some GGO lesions may be treated with sublobar resections; these findings...

  13. Ground-Glass Opacity Lung Nodules in the Era of Lung Cancer CT Screening

    DEFF Research Database (Denmark)

    Pedersen, Jesper Holst; Saghir, Zaigham; Wille, Mathilde Marie Winkler

    2016-01-01

    The advent of computed tomography screening for lung cancer will increase the incidence of ground-glass opacity (GGO) nodules detected and referred for diagnostic evaluation and management. GGO nodules remain a diagnostic challenge; therefore, a more systematic approach is necessary to ensure...... correct diagnosis and optimal management. Here we present the latest advances in the radiologic imaging and pathology of GGO nodules, demonstrating that radiologic features are increasingly predictive of the pathology of GGO nodules. We review the current guidelines from the Fleischner Society......, the National Comprehensive Cancer Network, and the British Thoracic Society. In addition, we discuss the management and follow-up of GGO nodules in the light of experience from screening trials. Minimally invasive tissue biopsies and the marking of GGO nodules for surgery are new and rapidly developing fields...

  14. CT colonography with rectal iodine tagging: Feasibility and comparison with oral tagging in a colorectal cancer screening population

    Energy Technology Data Exchange (ETDEWEB)

    Neri, Emanuele, E-mail: emanuele.neri@med.unipi.it [Diagnostic and Interventional Radiology – Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa (Italy); Mantarro, Annalisa; Faggioni, Lorenzo; Scalise, Paola; Bemi, Pietro; Pancrazi, Francesca [Diagnostic and Interventional Radiology – Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa (Italy); D’Ippolito, Giuseppe [Federal University of São Paulo – Sena Madureira 1500 – Vila Mariana, UNIFESP, São Paulo, SP (Brazil); Bartolozzi, Carlo [Diagnostic and Interventional Radiology – Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa (Italy)

    2015-09-15

    Highlights: • In the group receiving rectal tagging, mean per-polyp sensitivity, specificity were 96.1% and 95.3%; while in the group receiving oral tagging, mean per-polyp sensitivity, specificity were 89.4% and 95.8%. The difference between the two groups was not statistically significant (p = 0.549). • Rectal tagging can be an effective alternative to oral tagging. • Rectal tagging allowed greater patient acceptance and lower overall examination time. - Abstract: Purpose: To evaluate feasibility, diagnostic performance, patient acceptance, and overall examination time of CT colonography (CTC) performed through rectal administration of iodinated contrast material. Materials and methods: Six-hundred asymptomatic subjects (male:female = 270:330; mean 63 years) undergoing CTC for colorectal cancer screening on an individual basis were consecutively enrolled in the study. Out of them, 503 patients (group 1) underwent CTC with rectal tagging, of which 55 had a total of 77 colonic lesions. The remaining 97 patients (group 2) were randomly selected to receive CTC with oral tagging of which 15 had a total of 20 colonic lesions. CTC findings were compared with optical colonoscopy, and per-segment image quality was visually assessed using a semi-quantitative score (1 = poor, 2 = adequate, 3 = excellent). In 70/600 patients (11.7%), CTC was performed twice with both types of tagging over a 5-year follow-up cancer screening program. In this subgroup, patient acceptance was rated via phone interview two weeks after CTC using a semi-quantitative scale (1 = poor, 2 = fair, 3 = average, 4 = good, 5 = excellent). Results: Mean per-polyp sensitivity, specificity, positive and negative predictive values of CTC with rectal vs oral tagging were 96.1% (CI{sub 95%} 85.4 ÷ 99.3%) vs 89.4% (CI{sub 95%} 65.4 ÷ 98.1%), 95.3% (CI{sub 95%} 90.7 ÷ 97.8%) vs 95.8% (CI{sub 95%} 87.6 ÷ 98.9%), 86.0% (CI{sub 95%} 73.6 ÷ 93.3) vs 85.0% (CI{sub 95%} 61.1 ÷ 96.0%), and 98.8% (CI{sub 95

  15. CT-guided suprascapular nerve blocks: a pilot study

    Energy Technology Data Exchange (ETDEWEB)

    Schneider-Kolsky, M.E.; Pike, J.; Connell, D.A. [Department of Medical Imaging, Victoria House Private Hospital, 316 Malvern Road, Prahran 3181, Melbourne, Victoria (Australia)

    2004-05-01

    The objective of this study was to describe the suprascapular nerve block using CT guidance and to evaluate the short- and medium-term efficacy in a range of shoulder pathologies. CT-guided infiltration around the suprascapular nerve was performed with bupivacaine and Celestone Chronodose on 40 consecutive patients presenting with chronic shoulder pathologies unresponsive to conventional treatment. Patients were interviewed using the Shoulder Pain and Disability Index (SPADI) before the procedure, 30 min after the procedure and at 3 days, 3 weeks and 6 weeks afterwards. Within 30 min of the block overall pain scores decreased from a mean ({+-}SEM) pain score of 7.0 ({+-}0.4) to 3.5 ({+-}0.5) (n=39, P<0.001). At 3 days after the procedure, the mean overall improvement of the pain and disability scores were 20.4% ({+-}4.9, P<0.001) and 16.8% ({+-}4.8, P=0.004) respectively. Sustained pain relief and reduced disability were achieved in 10 of 35 (29%) patients at 3 weeks and longer. Patients suffering from soft tissue pathologies were the most likely patients to benefit from the injection. No serious side effects were noted. In some patients with chronic soft tissue pathologies who do not respond to conventional treatment, a CT-guided suprascapular nerve block can provide safe short- and medium-term relief from pain and disability. (orig.)

  16. Comparative study of bowtie and patient scatter in diagnostic CT

    Science.gov (United States)

    Prakash, Prakhar; Boudry, John M.

    2017-03-01

    A fast, GPU accelerated Monte Carlo engine for simulating relevant photon interaction processes over the diagnostic energy range in third-generation CT systems was developed to study the relative contributions of bowtie and object scatter to the total scatter reaching an imaging detector. Primary and scattered projections for an elliptical water phantom (major axis set to 300mm) with muscle and fat inserts were simulated for a typical diagnostic CT system as a function of anti-scatter grid (ASG) configurations. The ASG design space explored grid orientation, i.e. septa either a) parallel or b) parallel and perpendicular to the axis of rotation, as well as septa height. The septa material was Tungsten. The resulting projections were reconstructed and the scatter induced image degradation was quantified using common CT image metrics (such as Hounsfield Unit (HU) inaccuracy and loss in contrast), along with a qualitative review of image artifacts. Results indicate object scatter dominates total scatter in the detector channels under the shadow of the imaged object with the bowtie scatter fraction progressively increasing towards the edges of the object projection. Object scatter was shown to be the driving factor behind HU inaccuracy and contrast reduction in the simulated images while shading artifacts and elevated loss in HU accuracy at the object boundary were largely attributed to bowtie scatter. Because the impact of bowtie scatter could not be sufficiently mitigated with a large grid ratio ASG, algorithmic correction may be necessary to further mitigate these artifacts.

  17. Performance of ultralow-dose CT with iterative reconstruction in lung cancer screening: limiting radiation exposure to the equivalent of conventional chest X-ray imaging

    Energy Technology Data Exchange (ETDEWEB)

    Huber, Adrian [University Hospital Inselspital Bern, Department of Diagnostic, Interventional and Paediatric Radiology, Bern (Switzerland); University Hospital Pitie-Salpetriere, Department of Polyvalent and Oncological Radiology, Paris (France); Landau, Julia; Buetikofer, Yanik; Leidolt, Lars; Brela, Barbara; May, Michelle; Heverhagen, Johannes; Christe, Andreas [University Hospital Inselspital Bern, Department of Diagnostic, Interventional and Paediatric Radiology, Bern (Switzerland); Ebner, Lukas [University Hospital Inselspital Bern, Department of Diagnostic, Interventional and Paediatric Radiology, Bern (Switzerland); Duke University Medical Center, Department of Radiology, Durham, NC (United States)

    2016-10-15

    To investigate the detection rate of pulmonary nodules in ultralow-dose CT acquisitions. In this lung phantom study, 232 nodules (115 solid, 117 ground-glass) of different sizes were randomly distributed in a lung phantom in 60 different arrangements. Every arrangement was acquired once with standard radiation dose (100 kVp, 100 references mAs) and once with ultralow radiation dose (80 kVp, 6 mAs). Iterative reconstruction was used with optimized kernels: I30 for ultralow-dose, I70 for standard dose and I50 for CAD. Six radiologists examined the axial 1-mm stack for solid and ground-glass nodules. During a second and third step, three radiologists used maximum intensity projection (MIPs), finally checking with computer-assisted detection (CAD), while the others first used CAD, finally checking with the MIPs. The detection rate was 95.5 % with standard dose (DLP 126 mGy*cm) and 93.3 % with ultralow-dose (DLP: 9 mGy*cm). The additional use of either MIP reconstructions or CAD software could compensate for this difference. A combination of both MIP reconstructions and CAD software resulted in a maximum detection rate of 97.5 % with ultralow-dose. Lung cancer screening with ultralow-dose CT using the same radiation dose as a conventional chest X-ray is feasible. (orig.)

  18. Screening for Iron Overload: Lessons from the HEmochromatosis and IRon Overload Screening (HEIRS Study

    Directory of Open Access Journals (Sweden)

    Paul C Adams

    2009-01-01

    Full Text Available BACKGROUND: The HEmochromatosis and IRon Overload Screening (HEIRS Study provided data on a racially, ethnically and geographically diverse cohort of participants in North America screened from primary care populations.

  19. Fourier-wavelet restoration in PET/CT brain studies

    Energy Technology Data Exchange (ETDEWEB)

    Knesaurek, Karin, E-mail: karin.knesaurek@mssm.edu [Division of Nuclear Medicine, The Mount Sinai Medical Center, One Gustave L. Levy Place, New York, NY 10029 (United States)

    2012-10-11

    Our goal is to improve brain PET imaging through the application of a novel, hybrid Fourier-wavelet (WFT) restoration technique. The major limitation of PET studies is a relatively poor resolution in comparison with MRI and CT imaging and there is a need for improved PET imaging. A GE DLS PET/CT 16 slice system was used to acquire the studies. In order to create restoration filters the point source study was performed. The 6-fillable spheres and 3D Hoffman brain phantom studies were acquired and used to test and optimize the restoration approach. The patient data used in the study were acquired in a 3D PET mode, using the standard clinical protocol. Here, we have implemented Fourier-wavelet regularized restoration. In the Fourier domain, the inverse of modulation transfer function was multiplied by a Butterworth low-pass filter, order n=6 and cut-off frequency f=0.35 cycles/pixel. In addition, wavelet (Daubechies, order 2) noise suppression was applied by 'hard threshold'. Hot spheres and 3D Hoffman brain studies showed that the restoration process not only improves resolution and contrast but also improves quantification in 3D PET/CT imaging. The average contrast increase was 19% and the quantification improved in the range 8-20% depending on sphere size. In the restored images, there was no significant increase in noise when compared with the original images. The clinical studies followed brain phantom findings, i.e., the restored images had better contrast and resolution properties, when compared with the original images. The results of the study demonstrate that the quality and quantification of 3D brain {sup 18}F FDG PET images can be significantly improved by Fourier-wavelet (WFT) restoration filtering.

  20. Fourier-wavelet restoration in PET/CT brain studies

    Science.gov (United States)

    Knešaurek, Karin

    2012-10-01

    Our goal is to improve brain PET imaging through the application of a novel, hybrid Fourier-wavelet (WFT) restoration technique. The major limitation of PET studies is a relatively poor resolution in comparison with MRI and CT imaging and there is a need for improved PET imaging. A GE DLS PET/CT 16 slice system was used to acquire the studies. In order to create restoration filters the point source study was performed. The 6-fillable spheres and 3D Hoffman brain phantom studies were acquired and used to test and optimize the restoration approach. The patient data used in the study were acquired in a 3D PET mode, using the standard clinical protocol. Here, we have implemented Fourier-wavelet regularized restoration. In the Fourier domain, the inverse of modulation transfer function was multiplied by a Butterworth low-pass filter, order n=6 and cut-off frequency f=0.35 cycles/pixel. In addition, wavelet (Daubechies, order 2) noise suppression was applied by “hard threshold”. Hot spheres and 3D Hoffman brain studies showed that the restoration process not only improves resolution and contrast but also improves quantification in 3D PET/CT imaging. The average contrast increase was 19% and the quantification improved in the range 8-20% depending on sphere size. In the restored images, there was no significant increase in noise when compared with the original images. The clinical studies followed brain phantom findings, i.e., the restored images had better contrast and resolution properties, when compared with the original images. The results of the study demonstrate that the quality and quantification of 3D brain 18F FDG PET images can be significantly improved by Fourier-wavelet (WFT) restoration filtering.

  1. Patient experience of CT colonography and colonoscopy after fecal occult blood test in a national screening programme

    Energy Technology Data Exchange (ETDEWEB)

    Plumb, Andrew A.; Taylor, Stuart A.; Halligan, Steve [University College London, Centre for Medical Imaging, Division of Medicine, London (United Kingdom); Ghanouni, Alex; Von Wagner, Christian [University College London, Health Behaviour Research Centre, Department of Epidemiology and Public Health, London (United Kingdom); Rees, Colin J. [Durham University School of Medicine, Pharmacy and Health, Durham (United Kingdom); Hewitson, Paul [University of Oxford, Health Services Research Unit, Nuffield Department of Population Health, Oxford (United Kingdom); Nickerson, Claire; Wright, Suzanne [Fulwood House, NHS Cancer Screening Programmes, Sheffield (United Kingdom)

    2017-03-15

    To investigate patient experience of CT colonography (CTC) and colonoscopy in a national screening programme. Retrospective analysis of patient experience postal questionnaires. We included screenees from a fecal occult blood test (FOBt) based screening programme, where CTC was performed when colonoscopy was incomplete or deemed unsuitable. We analyzed questionnaire responses concerning communication of test risks, test-related discomfort and post-test pain, as well as complications. CTC and colonoscopy responses were compared using multilevel logistic regression. Of 67,114 subjects identified, 52,805 (79 %) responded. Understanding of test risks was lower for CTC (1712/1970 = 86.9 %) than colonoscopy (48783/50975 = 95.7 %, p < 0.0001). Overall, a slightly greater proportion of screenees found CTC unexpectedly uncomfortable (506/1970 = 25.7 %) than colonoscopy (10,705/50,975 = 21.0 %, p < 0.0001). CTC was tolerated well as a completion procedure for failed colonoscopy (unexpected discomfort; CTC = 26.3 %: colonoscopy = 57.0 %, p < 0.001). Post-procedural pain was equally common (CTC: 288/1970,14.6 %, colonoscopy: 7544/50,975,14.8 %; p = 0.55). Adverse event rates were similar in both groups (CTC: 20/2947 = 1.2 %; colonoscopy: 683/64,312 = 1.1 %), but generally less serious with CTC. Even though CTC was reserved for individuals either unsuitable for or unable to complete colonoscopy, we found only small differences in test-related discomfort. CTC was well tolerated as a completion procedure and was extremely safe. CTC can be delivered across a national screening programme with high patient satisfaction. (orig.)

  2. Patients' & healthcare professionals' values regarding true- & false-positive diagnosis when colorectal cancer screening by CT colonography: discrete choice experiment.

    Directory of Open Access Journals (Sweden)

    Darren Boone

    Full Text Available PURPOSE: To establish the relative weighting given by patients and healthcare professionals to gains in diagnostic sensitivity versus loss of specificity when using CT colonography (CTC for colorectal cancer screening. MATERIALS AND METHODS: Following ethical approval and informed consent, 75 patients and 50 healthcare professionals undertook a discrete choice experiment in which they chose between "standard" CTC and "enhanced" CTC that raised diagnostic sensitivity 10% for either cancer or polyps in exchange for varying levels of specificity. We established the relative increase in false-positive diagnoses participants traded for an increase in true-positive diagnoses. RESULTS: Data from 122 participants were analysed. There were 30 (25% non-traders for the cancer scenario and 20 (16% for the polyp scenario. For cancer, the 10% gain in sensitivity was traded up to a median 45% (IQR 25 to >85 drop in specificity, equating to 2250 (IQR 1250 to >4250 additional false-positives per additional true-positive cancer, at 0.2% prevalence. For polyps, the figure was 15% (IQR 7.5 to 55, equating to 6 (IQR 3 to 22 additional false-positives per additional true-positive polyp, at 25% prevalence. Tipping points were significantly higher for patients than professionals for both cancer (85 vs 25, p<0.001 and polyps (55 vs 15, p<0.001. Patients were willing to pay significantly more for increased sensitivity for cancer (p = 0.021. CONCLUSION: When screening for colorectal cancer, patients and professionals believe gains in true-positive diagnoses are worth much more than the negative consequences of a corresponding rise in false-positives. Evaluation of screening tests should account for this.

  3. Can nontriggered thoracic CT be used for coronary artery calcium scoring? A phantom study

    Energy Technology Data Exchange (ETDEWEB)

    Xie, Xueqian [Department of Radiology, University Medical Center Groningen, University of Groningen, Hanzeplein 1, 9700RB Groningen, The Netherlands and Center for Medical Imaging – North East Netherlands, Department of Radiology, University Medical Center Groningen, University of Groningen, Hanzeplein 1, 9700RB Groningen (Netherlands); Greuter, Marcel J. W. [Department of Radiology, University Medical Center Groningen, University of Groningen, Hanzeplein 1, 9700RB Groningen (Netherlands); Groen, Jaap M. [Department of Radiology, Zaans Medical Center, 1500EE Zaandam (Netherlands); Bock, Geertruida H. de [Department of Epidemiology, University Medical Center Groningen, University of Groningen, Hanzeplein 1, 9700RB Groningen (Netherlands); Oudkerk, Matthijs [Center for Medical Imaging – North East Netherlands, Department of Radiology, University Medical Center Groningen, University of Groningen, Hanzeplein 1, 9700RB Groningen (Netherlands); Jong, Pim A. de [Department of Radiology, University Medical Center Utrecht, University of Utrecht, 3584CX Utrecht (Netherlands); Vliegenthart, Rozemarijn [Department of Radiology, University Medical Center Groningen, University of Groningen, Hanzeplein 1, 9700RB Groningen, The Netherlands and Center for Medical Imaging – North East Netherlands, Department of Radiology, University of Groningen, University Medical Center Groningen, Hanzeplein 1, 9700RB Groningen (Netherlands)

    2013-08-15

    Purpose: Coronary artery calcium score, traditionally based on electrocardiography (ECG)-triggered computed tomography (CT), predicts cardiovascular risk. However, nontriggered CT is extensively utilized. The study-purpose is to evaluate the in vitro agreement in coronary calcium score between nontriggered thoracic CT and ECG-triggered cardiac CT.Methods: Three artificial coronary arteries containing calcifications of different densities (high, medium, and low), and sizes (large, medium, and small), were studied in a moving cardiac phantom. Two 64-detector CT systems were used. The phantom moved at 0–90 mm/s in nontriggered low-dose CT as index test, and at 0–30 mm/s in ECG-triggered CT as reference. Differences in calcium scores between nontriggered and ECG-triggered CT were analyzed by t-test and 95% confidence interval. The sensitivity to detect calcification was calculated as the percentage of positive calcium scores.Results: Overall, calcium scores in nontriggered CT were not significantly different to those in ECG-triggered CT (p > 0.05). Calcium scores in nontriggered CT were within the 95% confidence interval of calcium scores in ECG-triggered CT, except predominantly at higher velocities (≥50 mm/s) for the high-density and large-size calcifications. The sensitivity for a nonzero calcium score was 100% for large calcifications, but 46%± 11% for small calcifications in nontriggered CT.Conclusions: When performing multiple measurements, good agreement in positive calcium scores is found between nontriggered thoracic and ECG-triggered cardiac CT. Agreement decreases with increasing coronary velocity. From this phantom study, it can be concluded that a high calcium score can be detected by nontriggered CT, and thus, that nontriggered CT likely can identify individuals at high risk of cardiovascular disease. On the other hand, a zero calcium score in nontriggered CT does not reliably exclude coronary calcification.

  4. Performance Studies on Distributed Virtual Screening

    Directory of Open Access Journals (Sweden)

    Jens Krüger

    2014-01-01

    Full Text Available Virtual high-throughput screening (vHTS is an invaluable method in modern drug discovery. It permits screening large datasets or databases of chemical structures for those structures binding possibly to a drug target. Virtual screening is typically performed by docking code, which often runs sequentially. Processing of huge vHTS datasets can be parallelized by chunking the data because individual docking runs are independent of each other. The goal of this work is to find an optimal splitting maximizing the speedup while considering overhead and available cores on Distributed Computing Infrastructures (DCIs. We have conducted thorough performance studies accounting not only for the runtime of the docking itself, but also for structure preparation. Performance studies were conducted via the workflow-enabled science gateway MoSGrid (Molecular Simulation Grid. As input we used benchmark datasets for protein kinases. Our performance studies show that docking workflows can be made to scale almost linearly up to 500 concurrent processes distributed even over large DCIs, thus accelerating vHTS campaigns significantly.

  5. Assessing Organ Doses from Paediatric CT Scans—A Novel Approach for an Epidemiology Study (the EPI-CT Study

    Directory of Open Access Journals (Sweden)

    Steven L. Simon

    2013-02-01

    Full Text Available The increasing worldwide use of paediatric computed tomography (CT has led to increasing concerns regarding the subsequent effects of exposure to radiation. In response to this concern, the international EPI-CT project was developed to study the risk of cancer in a large multi-country cohort. In radiation epidemiology, accurate estimates of organ-specific doses are essential. In EPI-CT, data collection is split into two time periods—before and after introduction of the Picture Archiving Communication System (PACS introduced in the 1990s. Prior to PACS, only sparse information about scanner settings is available from radiology departments. Hence, a multi-level approach was developed to retrieve information from a questionnaire, surveys, scientific publications, and expert interviews. For the years after PACS was introduced, scanner settings will be extracted from Digital Imaging and Communications in Medicine (DICOM headers, a protocol for storing medical imaging data. Radiation fields and X-ray interactions within the body will be simulated using phantoms of various ages and Monte-Carlo-based radiation transport calculations. Individual organ doses will be estimated for each child using an accepted calculation strategy, scanner settings, and the radiation transport calculations. Comprehensive analyses of missing and uncertain dosimetry data will be conducted to provide uncertainty distributions of doses.

  6. Non- or full-laxative CT colonography vs. endoscopic tests for colorectal cancer screening: A randomised survey comparing public perceptions and intentions to undergo testing

    Energy Technology Data Exchange (ETDEWEB)

    Ghanouni, Alex; Wardle, Jane; Von Wagner, Christian [University College London, Health Behaviour Research Centre, Department of Epidemiology and Public Health, London (United Kingdom); Halligan, Steve; Plumb, Andrew; Boone, Darren [University College London, Centre for Medical Imaging, London (United Kingdom)

    2014-07-15

    Compare public perceptions and intentions to undergo colorectal cancer screening tests following detailed information regarding CT colonography (CTC; after non-laxative preparation or full-laxative preparation), optical colonoscopy (OC) or flexible sigmoidoscopy (FS). A total of 3,100 invitees approaching screening age (45-54 years) were randomly allocated to receive detailed information on a single test and asked to return a questionnaire. Outcomes included perceptions of preparation and test tolerability, health benefits, sensitivity and specificity, and intention to undergo the test. Six hundred three invitees responded with valid questionnaire data. Non-laxative preparation was rated more positively than enema or full-laxative preparations [effect size (r) = 0.13 to 0.54; p < 0.0005 to 0.036]; both forms of CTC and FS were rated more positively than OC in terms of test experience (r = 0.26 to 0.28; all p-values < 0.0005). Perceptions of health benefits, sensitivity and specificity (p = 0.250 to 0.901), and intention to undergo the test (p = 0.213) did not differ between tests (n = 144-155 for each test). Despite non-laxative CTC being rated more favourably, this study did not find evidence that offering it would lead to substantially higher uptake than full-laxative CTC or other methods. However, this study was limited by a lower than anticipated response rate. (orig.)

  7. [Breast dose reduction in female CT screening for lung cancer using various metallic shields].

    Science.gov (United States)

    Takada, Kenta; Kaneko, Junichi; Aoki, Kiyoshi

    2009-12-20

    We evaluated the effectiveness of metallic shields that were used for reduction of the breast dose in thoracic computed tomography(CT). For the evaluation, we measured breast surface dose and image standard deviation(SD)in the lung area. The metallic shields were made from bismuth, zinc, copper, and iron. The bismuth shield has been marketed and used for dose reduction. The other three metallic shields were chosen because they have lower atomic numbers and a lower yield of characteristic X-rays. As a result, use of the metallic shields showed a lower breast dose than the decrement of the tube current in the same image SD. The insertion of a thin aluminum sheet between the shield and a phantom was also effective in reducing breast surface dose. We calculated the dose reduction rate to evaluate the effectiveness of these metallic shields. This dose reduction rate was defined as the ratio of the decrease in breast surface dose by metallic shields to the breast surface dose measured with the tube current decrement in the same image SD. The maximum dose reduction rate was 6.4% for the bismuth shield, and 12.0-13.3% for the other shields. These results indicate that the shields made from zinc, copper, and iron are more effective for dose reduction than the shield made form bismuth. The best dose reduction rate, 13.3%, has been achieved when the zinc shield placed 20 mm apart from a phantom with 0.2 mm aluminum was used.

  8. Hospital malnutrition: a 33-hospital screening study.

    Science.gov (United States)

    Kamath, S K; Lawler, M; Smith, A E; Kalat, T; Olson, R

    1986-02-01

    A collaborative study involving nutrition screening of 3,047 patients (excluding 125 pregnant women) at admission to 33 hospitals in and around the greater Chicago area was carried out to identify patients at nutritional risk. Information on sex, age, admitting diagnosis, serum albumin, hemoglobin, total lymphocyte count, and height and weight was collected from the medical chart within 48 hours of admission. Nutrition screening could not be completed for a larger number of patients (60%) because data at admission were not available. Of the remaining 40% of patients, more than 50% had below normal values for one or more of the variables studied: serum albumin, hemoglobin, and total lymphocyte count. A large number of the patients (40%) also were considered at nutritional risk as judged by the criteria of weight/height (measured only). Early nutrition intervention for high-risk patients cannot be implemented, nor can the efficacy of nutrition services be evaluated, unless nutrition screening is carried out on patients at admission.

  9. CT studies in hyperprolactinemia; Badania KT w hiperprolaktynemii

    Energy Technology Data Exchange (ETDEWEB)

    Gradzki, J.; Paprzycki, W.; Krzyzagorska, E.; Wasko, R.; Warenik-Szymankiewicz, A. [Akademia Medyczna, Poznan (Poland)

    1993-12-31

    Computerized tomography studies in 62 patients (55 females and 7 males) with hyperprolactinemia are presented. The female patients had secondary amenorrhea and galactorrhea, whereas the male patients suffered from impotency, gynaecomastia and very rarely galactorrhea. In 39 cases CT revealed a pituitary adenoma (prolactinoma), in 14 cases of them microadenoma, as the cause of hormonal and clinical disturbances. In 21 cases an empty sella with rudimentary pituitary surrounded by cerebrospinal fluid or lack of pituitary mass were found. In one case suprasellar and intrasellar calcifications were present. (author). 17 refs, 4 figs.

  10. Helical CT for lumbosacral spinal

    Energy Technology Data Exchange (ETDEWEB)

    Tatsuno, Satoshi; Fukuda, Kunihiko [Jikei Univ., Tokyo (Japan). School of Medicine

    1996-10-01

    The aim of this study was to investigate the efficacy of helical CT for lumbosacral pathology. We performed helical CT with multiplanar reconstruction, including the formation of oblique transaxial and coronal images, in 62 patients with various lumboscral disorders, including 32 non-enhanced CT and 36 CT after myelography. We correlated the appearance of the stenotic spinal canal and neoplastic disease with the findings on MRI obtained at nearly the same time. We obtained helical CT images in all cases in about 30 seconds. The diagnostic ability of helical CT was roughly equal to that of MRI in patients with spondylosis deformans, spondylolisthesis and herniated nucleus pulposus. There was no significant difference in diagnostic value for degenerative lumbosacral disease with canal and foraminal stenosis between non-enhanced and post-myelography helical CT. However, non-enhanced helical CT could not clearly demonstrate neoplastic disease because of the poor contrast resolution. Helical CT was useful in evaluating degenerative disorder and its diagnostic value was nearly equal to that of MRI. We considered that helical CT may be suitable for the assessment of patients with severe lumbago owing to the markedly shortened examination time. However, if helical CT is used as a screening method for lumbosacral disease, one must be careful of its limitations, for example, poor detectability of neoplastic disease, vascular anomalies and so on. (author)

  11. Dose profile study in head CT scans using radiochromic films

    Energy Technology Data Exchange (ETDEWEB)

    Ladino G, A. M.; Prata M, A., E-mail: amlgphys@gmail.com [Universidade Federal de Minas Gerais, Departamento de Engenharia Nuclear, Av. Pte. Antonio Carlos 6627, 31270-901 Belo Horizonte, Minas Gerais (Brazil)

    2016-10-15

    Diagnostic images of computed tomography generate higher doses than other methods of diagnostic radiology using X-ray beam attenuation. Clinical applications of CT have been increased by technological advances, what leads to a wide variety of scanner in the Brazilian technological pool. It has been difficult to implement dose reduction strategies because of the lack of proper guidance on computed tomography examinations. However, CT scanners allow adjusting acquisition parameter according to the patients physical profile and diagnostic application for which the scan is intended. The knowledge of the dose distribution is important because changes in image acquisition parameters may provide dose reduction. In this study, it was used a cylindrical head phantom in PMMA with 5 openings, what allows dose measurement in 5 regions. In a GE CT scanner, Discovery model of 64 channels, the central slice of the head phantom was irradiated and the absorbed doses were measured using a pencil ionization chamber. Radiochromic film strips were placed in the peripheral and in the central region of the head phantom and was performed a scan of 10 cm in the phantom central region. The scan was performed using the head scanning protocol of the radiobiology service, with a voltage of 120 kV. After scanning, the radiochromic film strips were digitalized and their digital images were used to have the dose longitudinal profiles. The dose values recorded have variation in a range of 18.66 to 23.57 mGy. In the results it was compared the dose index values obtained by the pencil chamber measurement to the dose longitudinal profiles recorded by the film strips. (Author)

  12. 多层螺旋CT双期增强扫描对肝微小细胞癌的诊断价值%Study on the application of the multislice spiral CT screening on small hepatocellular carcinoma in dual-phase enhanced scanning

    Institute of Scientific and Technical Information of China (English)

    王建锋

    2016-01-01

    Objective To explore the application of the multislice spiral CT screening on small hepatocellular carcinoma in dual-phase enhanced scanning .Methods 36 patients with small hepatocellular carcinoma were collected from our department , every patient was examined using Plain and dual phase enhanced CT scan , all patients were confirmed by histopathology .We ana-lyzed the density and edge features of plain and dual phase enhanced CT scan , compared the detection rate of small hepatocellular carcinoma and the changes of different scanning phase of tumor and the liver density difference .Results The range of small hep-atocellular carcinoma was 2.0~1.3 cm, the lesion which showed circular low density in plain CT was 83.3%, equidensite was 16.7%, uniform density in enhanced CT scan accounted for 58.3%, tumor uneven density was 41.7%, boundary clearly in en-hanced CT scan accounted for 66.7%, fuzzy boundaries accounted for 33.3%;the detection rate of arterial phase was 91.7%, detection rate of portal venous phase was 80.6%, and detection rate of CT scan was 63.9%, the difference was statistically sig-nificant ( P <0.05);The difference between tumor and hepatic portal phase density was the biggest , the difference bewtween the scan period of tumor and the liver density was the minimum , the difference of the portal venous phase and arterial phase scan and was significant ( P <0.05).Conclusion Spiral CT of dual phase scan had high detection rate on small hepatocellular carcino-ma, which had accurate and reliable value .%目的:探讨多层螺旋CT双期增强扫描对原发性肝微小细胞癌的诊断价值。方法对36例肝微小细胞癌的患者,分别采用CT平扫及双期增强扫描对患者进行检查,所有患者均经病理组织证实;分析平扫和增强扫描病灶的密度和边缘表现,并对小肝癌检出率及不同扫描时相肿瘤与肝脏密度差值的变化情况进行比较。结果肝微小细胞癌的病灶范围在1.3~2.0cm

  13. Diagnostic performance of CT colonography with limited cathartic preparation in colorectal cancer screening; comparison with conventional colonoscopy

    Directory of Open Access Journals (Sweden)

    Mohammed Farghally Amin

    2015-09-01

    Conclusion: This study proved that CTC with limited cathartic bowel preparation and iodinated agents for fecal tagging can obtain high sensitivity and PPV values results for <5 mm polyps comparable to those obtained with conventional preparation with laxatives. Furthermore, this method could really improve the acceptance of CTC for colorectal cancer screening.

  14. Thin-Section CT Characteristics and Longitudinal CT Follow-up of Chemotherapy Induced Interstitial Pneumonitis: A Retrospective Cohort Study.

    Science.gov (United States)

    Lee, Han Na; Kim, Mi Young; Koo, Hyun Jung; Kim, Sung-Soo; Yoon, Dok Hyun; Lee, Jae Cheol; Song, Jin Woo

    2016-01-01

    To describe the computed tomography (CT) features of chemotherapy-induced interstitial pneumonitis (CIIP) with longitudinal follow-up.The study was approved by the local ethics committee. One hundred consecutive patients with CIIP between May 2005 and March 2015 were retrospectively enrolled. The initial CT was reviewed by 2 independent chest radiologists and categorized into 1 of 4 CT patterns in accordance with the 2013 guidelines for idiopathic interstitial pneumonia: nonspecific interstitial pneumonia (NSIP), organizing pneumonia (OP), hypersensitivity pneumonitis (HP) mimicking desquamative interstitial pneumonitis, and diffuse alveolar damage (DAD). We assessed semiquantitative analysis on a 5% scale to assess the extent of parenchymal abnormalities (emphysema, reticulation, ground-glass opacity, consolidation, honeycombing cyst) and their distribution on initial (n = 100), subsequent (n = 87), and second follow-up CT (n = 48). Interval changes in extent on follow-up CT were compared using paired t test. The clinic-radiologic factors were compared between Group 1 (NSIP and OP patterns) and Group 2 (HP and DAD patterns) using χ and independent t tests.The most common pattern of CIIP on the initial CT was HP (51%), followed by NSIP (23%), OP (20%), and DAD (6%). Diffuse ground-glass opacity was the most common pulmonary abnormality. The predominant distribution was bilateral (99%) and symmetric (82%), with no craniocaudal (60%) or axial (79%) dominance. Subsequent and second follow-up CTs showed decreased extent of total pulmonary abnormalities (P CIIP, Group 2 CIIP was more likely to be caused by molecularly targeted drugs (P = 0.030), appeared earlier (P = 0.034), and underwent more complete resolution (P CIIP is appropriate and practical in interpreting radiological findings.

  15. Study of Screen Design Principles for Visualizing Medical Records.

    Science.gov (United States)

    Fujita, Kenichiro; Takemura, Tadamasa; Kuroda, Tomohiro

    2015-01-01

    To improve UX of EMR/EHR, the screen design principles for the visualization are required. Through the study of common attributes of medical records, we present four principles and show three screen designs by applying them.

  16. Effect of CT screening on smoking habits at 1-year follow-up in the Danish Lung Cancer Screening Trial (DLCST)

    DEFF Research Database (Denmark)

    Ashraf, H; Tønnesen, P; Holst Pedersen, J

    2008-01-01

    (DLCST), a 5-year randomised controlled trial comprising 4104 subjects; 2052 subjects received annual low-dose CT scan (CT group) and 2052 received no intervention (control group). Participants were healthy current and former smokers (>4 weeks since smoking cessation) with a tobacco consumption of >20...

  17. A study on CT diagnosis of pancreatic diseases

    Energy Technology Data Exchange (ETDEWEB)

    Han, Man Chung; Lim, Tae Hwan; Chang, Kee Hyun; Park, Jae Hyung; Yeon, Kyung Mo; Kim, Chung Yong; Yoon, Yong Bum; Song, Sung In [Seoul National University College of Medicine, Seoul (Korea, Republic of)

    1982-06-15

    Authors retrospectively analysed abdominal CT findings of 120 patients, of whom the CT was done under the clinical impression of pancreatic diseases. These include 20 patients of acute pancreatitis, 12 patients of chronic pancreatitis, and 41 patients of pancreatic tumor. Remaining 47 patients were proved to have normal pancreas. CT permitted correct diagnosis in 108 of 120 patients with diagnostic accuracy 91%, sensitivity 95%, and specificity 79%. Predictive value of positive CT diagnosis was 93% and that of negative diagnosis was 82%. Commonly observed CT findings of acute pancreatitis were diffuse pancreatic enlargement (75%), obliteration of peripancreatic fat planes (70%), peripancreatic 'Dirty fat' (50%), and renal fasical thickening (50%). Abscess formation, pseudocyst formation, phlegmon, and fluid collection were the complications of acute pancreatitis in order of frequency. In chronic pancreatitis, pancreatic calcification was the most frequent (58%) and specific CT finding. Pancreas size were normal in 2 patients (16%), atrophic in 5 patients (42%), and enlarged in 5 patients (42%). Of 40 patients with pancreatic cancer, 36 patients showed pancreatic mass on CT, and 18 were with central low density. Other findings of pancreatic cancer were obliteration of peripancreatic fat plane (60%), biliary dilation (30%), and secondary pancreatitis (18%). Liver and lymph nodes metastases were found in 27 patients (68%) at the time of CT scanning.

  18. Extracolonic Findings on CT Colonography Increases Yield of Colorectal Cancer Screening

    Science.gov (United States)

    2010-09-01

    gallstones; hiatal hernia E3 Likely unimportant finding, incompletely characterized: workup may be indicated Complex renal cyst; lung nodule E4...of which were renal cysts, neph­ rolithiasis, hiatal hernias , or benign liver cysts. The majority of findings for patients in the E3 group (n = 211...costs and studies generated. In addition, following patients out to their final diagnosis and, especially , establishing histologic diagno­ ses for

  19. Descriptive epidemiology of screen and non-screen sedentary time in adolescents: a cross sectional study

    Directory of Open Access Journals (Sweden)

    Ridley Kate

    2010-12-01

    Full Text Available Abstract Background Much attention has been paid to adolescents' screen time, however very few studies have examined non-screen sedentary time (NSST. This study aimed to (1 describe the magnitude and composition of screen sedentary time (SST and NSST in Australian adolescents, (2 describe the socio-demographic correlates of SST and NSST, and (3 determine whether screen time is an adequate surrogate for total sedentary behaviour in this population. Methods 2200 9-16 year old Australians provided detailed use of time data for four days. Non-screen sedentary time (NSST included time spent participating in activities expected to elicit Results Adolescents spent a mean (SD of 345 (105 minutes/day in NSST, which constituted 60% of total sedentary time. School activities contributed 42% of NSST, socialising 19%, self-care (mainly eating 16%, and passive transport 15%. Screen time and NSST showed opposite patterns in relation to key socio-demographic characteristics, including sex, age, weight status, household income, parental education and day type. Because screen time was negatively correlated with NSST (r = -0.58, and exhibited a moderate correlation (r = 0.53 with total sedentary time, screen time was only a moderately effective surrogate for total sedentary time. Conclusions To capture a complete picture of young people's sedentary time, studies should endeavour to measure both screen time and NSST.

  20. Attenuation correction effects on SPECT/CT procedures: phantoms studies.

    Science.gov (United States)

    Oliveira, M L; Seren, M E G; Rocha, F C; Brunetto, S Q; Ramos, C D; Button, V L S N

    2013-01-01

    Attenuation correction is widely used in SPECT/CT (Single Photon Emission Computed Tomography) procedures, especially for imaging of the thorax region. Different compensation methods have been developed and introduced into clinical practice. Most of them use attenuation maps obtained using transmission scanning systems. However, this gives extra dose of radiation to the patient. The purpose of this study was to identify when attenuation correction is really important during SPECT/CT procedures.For this purpose, we used Jaszczak phantom and phantom with three line sources, filled with technetium ((99m)-Tc), with scattering materials, like air, water and acrylic, in different detectors configurations. In all images acquired were applied analytic and iterative reconstruction algorithms; the last one with or without attenuation correction. We analyzed parameters such as eccentricity, contrast and spatial resolution in the images.The best reconstruction algorithm on average was iterative, for images with 128 × 128 and 64 × 64 matrixes. The analytical algorithm was effective only to improve eccentricity in 64 × 64 matrix and matrix in contrast 128 × 128 with low statistics. Turning to the clinical routine examinations, on average, for 128 × 128 matrix and low statistics counting, the best algorithm was the iterative, without attenuation correction,improving in 150% the three parameters analyzed and, for the same matrix size, but with high statistical counting, iterative algorithm with attenuation correction was 25% better than that without correction. We can conclude that using the iterative algorithm with attenuation correction in the water, and its extra dose given, is not justified for the procedures of low statistic counting, being relevant only if the intention is to prioritize contrast in acquisitions with high statistic counting.

  1. Study of CT and etiology In 11B cases of eoute headache without hemlplegla

    Institute of Scientific and Technical Information of China (English)

    Daoming Tong

    2000-01-01

    objectal To study the relation between CT and etiology of acute headache without hemiplegia. Methods 118 cases of acute headache without hemiplegia were studied with CT scan. The patients with normal CT were diagnosed with lumbar punc -tura or diagnostic standard for establishing disease. Results The first three etiologies were cerebrovescular disease (65 cases, 55%), migraine (25 cases, 21%), meningitis and encephalitis (19 cases, 155. 9%). 53% of patients with subarachnoid hemorrhage(SAH) was diagnosed in CT unnormal group, and 12.4% of patients with Sall was showed by lumbar puncture in CT normal group(P<0. 001). CT was normal in 18% of patients with a definite SAH(7/39). The positive rates of intracranial infection in CT normal group(by lumbar puncture) was reearkably higher than in CT unnormal group (18/58 versus 2/60, p<0.005), Conolusion CT is more sensitive to intracranial hemorrhage, tumor and infarction. SAH of a negative Ctscan is not rare. CT is far inferior to lumbar puncture in meningitis or encephalitis.

  2. CT in the diagnosis of abdominal wall hernias: a preliminary study

    Energy Technology Data Exchange (ETDEWEB)

    Hoejer, A.M.; Jess, P. [Department of Surgery, Roskilde County Hospital Koege, DK-4600 Koege (Denmark); Rygaard, H. [Department of Radiology, Roskilde County Hospital Koege, DK-4600 Koege (Denmark)

    1997-12-01

    The aim of the study was to estimate the value of CT in the diagnosis of abdominal wall hernias and at the same time to create a standard for this CT investigation. Twenty-four patients with suspected hernia of the abdominal wall were examined. All were operated on. The CT scans were assessed by two radiologists to estimate the interobserver variation. The CT diagnoses made by the two radiologists were correct in 83 % and 79 % of cases, respectively. The sensitivity was 0.83 in both CT evaluations and the specificity was 0.83 and 0.67, respectively. The predictive value of a positive CT finding was 0.94 and 0.88, while the predictive value of a negative CT finding was 0.63 and 0.57, respectively. The interobserver variation (kappa) was 0.87. The study therefore indicates that a positive CT finding of abdominal wall hernia is reliable, while a negative finding does not exclude the diagnosis. The interobserver variation of the CT diagnoses is acceptable. To achieve the highest diagnostic accuracy, it is recommended to always use the Valsalva manoeuvre, oral intake of contrast and 10/10 mm CT slices. (orig.) With 3 figs., 1 tab., 7 refs.

  3. Breast density and outcome of mammography screening: a cohort study

    DEFF Research Database (Denmark)

    Olsen, A H; Bihrmann, K; Jensen, M-B

    2009-01-01

    The purpose of this study was to investigate the effect of breast density on breast cancer (BC) mortality in a mammography screening programme. The cohort included 48 052 women participating in mammography screening in Copenhagen, Denmark, where biennial screening is offered to women aged 50-69 y...

  4. Regional lymph node involvement in T1 papillary thyroid carcinoma: a bicentric prospective SPECT/CT study

    Energy Technology Data Exchange (ETDEWEB)

    Mustafa, Mona [Ludwig Maximilian University, Department of Nuclear Medicine, Munich (Germany); Klinikum Grosshadern, Department of Nuclear Medicine, Munich (Germany); Kuwert, Torsten; Linke, Rainer; Schmidt, Daniela [University of Erlangen-Nuernberg, Department of Nuclear Medicine, Erlangen (Germany); Weber, Kathrin; Knesewitsch, Peter; Haug, Alexander; Bartenstein, Peter [Ludwig Maximilian University, Department of Nuclear Medicine, Munich (Germany); Negele, Thomas [Hospital Martha Maria, Department of Surgery, Munich (Germany)

    2010-08-15

    Hybrid imaging combining single photon emission computed tomography (SPECT) with {sup 131}I and X-ray computed tomography (CT) performed at radioablation (RA) for thyroid carcinoma more accurately detects regional lymph node metastases (LNM) than does planar imaging. In this bicentric prospective study we used hybrid imaging in conjunction with histopathological examination to measure LNM frequency in a consecutive group of patients referred for RA due to stage T1 papillary thyroid carcinoma (PTC). At the Departments of Nuclear Medicine of the Ludwig Maximilian University of Munich and the Friedrich Alexander University of Erlangen-Nuremberg SPECT/spiral CT is routinely performed in all PTC subjects at the time of RA. Screening of our SPECT/CT databases for PTC patients with T1 histology produced 98 patients from Munich and 53 patients from Erlangen, including 96 of 151 patients with microcarcinoma. In 69 patients of the entire group, cervical lymph node dissection had been performed, whereas nodal staging in the remaining 82 subjects was based on SPECT/CT. LNM incidence in the whole group was 26% [95% confidence interval (CI): 20-33%] versus 22% (95% CI: 15-31%) in the microcarcinoma subgroup. SPECT/CT was more accurate in 24.5% of our patients than planar imaging with regard to nodal staging. LNM occurs in one quarter of all patients with T1 PTC, and also in the subset with microcarcinoma. Performing {sup 131}I SPECT/CT, either with therapeutic or diagnostic radioactivities, directly after thyroidectomy should provide more accurate staging of T1 PTC, thus facilitating optimal therapeutic management. (orig.)

  5. TU-G-204-09: The Effects of Reduced- Dose Lung Cancer Screening CT On Lung Nodule Detection Using a CAD Algorithm

    Energy Technology Data Exchange (ETDEWEB)

    Young, S; Lo, P; Kim, G; Hsu, W; Hoffman, J; Brown, M; McNitt-Gray, M [UCLA School of Medicine, Los Angeles, CA (United States)

    2015-06-15

    Purpose: While Lung Cancer Screening CT is being performed at low doses, the purpose of this study was to investigate the effects of further reducing dose on the performance of a CAD nodule-detection algorithm. Methods: We selected 50 cases from our local database of National Lung Screening Trial (NLST) patients for which we had both the image series and the raw CT data from the original scans. All scans were acquired with fixed mAs (25 for standard-sized patients, 40 for large patients) on a 64-slice scanner (Sensation 64, Siemens Healthcare). All images were reconstructed with 1-mm slice thickness, B50 kernel. 10 of the cases had at least one nodule reported on the NLST reader forms. Based on a previously-published technique, we added noise to the raw data to simulate reduced-dose versions of each case at 50% and 25% of the original NLST dose (i.e. approximately 1.0 and 0.5 mGy CTDIvol). For each case at each dose level, the CAD detection algorithm was run and nodules greater than 4 mm in diameter were reported. These CAD results were compared to “truth”, defined as the approximate nodule centroids from the NLST reports. Subject-level mean sensitivities and false-positive rates were calculated for each dose level. Results: The mean sensitivities of the CAD algorithm were 35% at the original dose, 20% at 50% dose, and 42.5% at 25% dose. The false-positive rates, in decreasing-dose order, were 3.7, 2.9, and 10 per case. In certain cases, particularly in larger patients, there were severe photon-starvation artifacts, especially in the apical region due to the high-attenuating shoulders. Conclusion: The detection task was challenging for the CAD algorithm at all dose levels, including the original NLST dose. However, the false-positive rate at 25% dose approximately tripled, suggesting a loss of CAD robustness somewhere between 0.5 and 1.0 mGy. NCI grant U01 CA181156 (Quantitative Imaging Network); Tobacco Related Disease Research Project grant 22RT-0131.

  6. Low-dose CT pulmonary angiography on a 15-year-old CT scanner: a feasibility study

    Directory of Open Access Journals (Sweden)

    Moritz Kaup

    2016-12-01

    Full Text Available Background Computed tomography (CT low-dose (LD imaging is used to lower radiation exposure, especially in vascular imaging; in current literature, this is mostly on latest generation high-end CT systems. Purpose To evaluate the effects of reduced tube current on objective and subjective image quality of a 15-year-old 16-slice CT system for pulmonary angiography (CTPA. Material and Methods CTPA scans from 60 prospectively randomized patients (28 men, 32 women were examined in this study on a 15-year-old 16-slice CT scanner system. Standard CT (SD settings were 100 kV and 150 mAs, LD settings were 100 kV and 50 mAs. Attenuation of the pulmonary trunk, various anatomic landmarks, and image noise were quantitatively measured; contrast-to-noise ratios (CNR and signal-to-noise ratios (SNR were calculated. Three independent blinded radiologists subjectively rated each image series using a 5-point grading scale. Results CT dose index (CTDI in the LD series was 66.46% lower compared to the SD settings (2.49 ± 0.55 mGy versus 7.42 ± 1.17 mGy. Attenuation of the pulmonary trunk showed similar results for both series (SD 409.55 ± 91.04 HU; LD 380.43 HU ± 93.11 HU; P = 0.768. Subjective image analysis showed no significant differences between SD and LD settings regarding the suitability for detection of central and peripheral PE (central SD/LD, 4.88; intra-class correlation coefficients [ICC], 0.894/4.83; ICC, 0.745; peripheral SD/LD, 4.70; ICC, 0.943/4.57; ICC, 0.919; all P > 0.4. Conclusion The LD protocol, on a 15-year-old CT scanner system without current high-end hardware or post-processing tools, led to a dose reduction of approximately 67% with similar subjective image quality and delineation of central and peripheral pulmonary arteries.

  7. Breast cancer screening: An outpatient clinic study

    Directory of Open Access Journals (Sweden)

    Mustafa Girgin

    2017-03-01

    Conclusion: A multidisciplinary cancer screening program should be maintained. With such a process, the aim is to reduce the morbidity and mortality of the disease without adversely affecting the health conditions of asymptomatic individuals based on the screening. Success is brought about by the combination of individual features. [Arch Clin Exp Surg 2017; 6(1.000: 23-27

  8. Pilot study: relative dose of the TLD, OSL and Radiochromic film applied in CT exams dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Kikuti, C.F. [Universidade Federal do Mato Grosso do Sul (UFMS), Campo Grande, MS (Brazil). Hospital Universitario Maria Aparecida Pedrossian; Maia, R.S.I.; Romano, R.F.T.; Daros, K. A.C., E-mail: daros.kellen@unifesp.br [Universidade Federal de Sao Paulo (UNIFESP), Sao Paulo, SP (Brazil). Escola Paulista de Medicina. Departamento de Diagnostico por Imagem

    2015-07-01

    At DDI/UNIFESP, the abdomen and chest CT exams correspond to 38% of the exams, becoming the focus of studies. The aim of this study is to assess the relative dose using TLDs, OSLs and RF for the evaluation of the dose distribution in the skin in abdomen CT exams. The simulation of the CT exam was performed in an anthropomorphic phantom, using a CT scanner Philips, Brilliance/64 and TLDs, OSLs and RF fixed along the sagittal axis of the phantom. The OSLs showed similar performance to the TLDs and RF shows low accuracy, resulting in an average value (0.927±0.022). (author)

  9. Structure and Protein-Protein Interaction Studies on Chlamydia trachomatis Protein CT670 (YscO Homolog)

    Energy Technology Data Exchange (ETDEWEB)

    Lorenzini, Emily; Singer, Alexander; Singh, Bhag; Lam, Robert; Skarina, Tatiana; Chirgadze, Nickolay Y.; Savchenko, Alexei; Gupta, Radhey S. (Toronto); (McMaster U.); (OCI)

    2010-07-28

    Comparative genomic studies have identified many proteins that are found only in various Chlamydiae species and exhibit no significant sequence similarity to any protein in organisms that do not belong to this group. The CT670 protein of Chlamydia trachomatis is one of the proteins whose genes are in one of the type III secretion gene clusters but whose cellular functions are not known. CT670 shares several characteristics with the YscO protein of Yersinia pestis, including the neighboring genes, size, charge, and secondary structure, but the structures and/or functions of these proteins remain to be determined. Although a BLAST search with CT670 did not identify YscO as a related protein, our analysis indicated that these two proteins exhibit significant sequence similarity. In this paper, we report that the CT670 crystal, solved at a resolution of 2 {angstrom}, consists of a single coiled coil containing just two long helices. Gel filtration and analytical ultracentrifugation studies showed that in solution CT670 exists in both monomeric and dimeric forms and that the monomer predominates at lower protein concentrations. We examined the interaction of CT670 with many type III secretion system-related proteins (viz., CT091, CT665, CT666, CT667, CT668, CT669, CT671, CT672, and CT673) by performing bacterial two-hybrid assays. In these experiments, CT670 was found to interact only with the CT671 protein (YscP homolog), whose gene is immediately downstream of ct670. A specific interaction between CT670 and CT671 was also observed when affinity chromatography pull-down experiments were performed. These results suggest that CT670 and CT671 are putative homologs of the YcoO and YscP proteins, respectively, and that they likely form a chaperone-effector pair.

  10. Effects of CT dose and nodule characteristics on lung-nodule detectability in a cohort of 90 national lung screening trial patients

    Science.gov (United States)

    Young, Stefano; Lo, Pechin; Hoffman, John M.; Kim, H. J. Grace; Brown, Matthew S.; McNitt-Gray, Michael F.

    2016-03-01

    Lung cancer screening CT is already performed at low dose. There are many techniques to reduce the dose even further, but it is not clear how such techniques will affect nodule detectability. In this work, we used an in-house CAD algorithm to evaluate detectability. 90348 patients and their raw CT data files were drawn from the National Lung Screening Trial (NLST) database. All scans were acquired at ~2 mGy CTDIvol with fixed tube current, 1 mm slice thickness, and B50 reconstruction kernel on a Sensation 64 scanner (Siemens Healthcare). We used the raw CT data to simulate two additional reduced-dose scans for each patient corresponding to 1 mGy (50%) and 0.5 mGy (25%). Radiologists' findings on the NLST reader forms indicated 65 nodules in the cohort, which we subdivided based on LungRADS criteria. For larger category 4 nodules, median sensitivities were 100% at all three dose levels, and mean sensitivity decreased with dose. For smaller nodules meeting the category 2 or 3 criteria, the dose dependence was less obvious. Overall, mean patient-level sensitivity varied from 38.5% at 100% dose to 40.4% at 50% dose, a difference of only 1.9%. However, the false-positive rate quadrupled from 1 per case at 100% dose to 4 per case at 25% dose. Dose reduction affected lung-nodule detectability differently depending on the LungRADS category, and the false-positive rate was very sensitive at sub-screening dose levels. Thus, care should be taken to adapt CAD for the very challenging noise characteristics of screening.

  11. Feasibility study of CT perfusion imaging for prostate carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Cullu, Nesat [Mugla Sitki Kocman University, School of Medicine, Department of Radiology, Mugla (Turkey); Atatuerk University, School of Medicine, Department of Radiology, Erzurum (Turkey); Kantarci, Mecit; Ogul, Hayri; Pirimoglu, Berhan; Karaca, Leyla; Kizrak, Yesim [Atatuerk University, School of Medicine, Department of Radiology, Erzurum (Turkey); Adanur, Senol; Koc, Erdem; Polat, Ozkan [Atatuerk University, School of Medicine, Department of Urology, Erzurum (Turkey); Okur, Aylin [Atatuerk University, School of Medicine, Department of Radiology, Erzurum (Turkey); Bozok University, School of Medicine, Department of Radiology, Yozgat (Turkey)

    2014-09-15

    The aim of this feasibility study was to obtain initial data with which to assess the efficiency of perfusion CT imaging (CTpI) and to compare this with magnetic resonance imaging (MRI) in the diagnosis of prostate carcinoma. This prospective study involved 25 patients with prostate carcinoma undergoing MRI and CTpI. All analyses were performed on T2-weighted images (T2WI), apparent diffusion coefficient (ADC) maps, diffusion-weighted images (DWI) and CTp images. We compared the performance of T2WI combined with DWI and CTp alone. The study was approved by the local ethics committee, and written informed consent was obtained from all patients. Tumours were present in 87 areas according to the histopathological results. The diagnostic performance of the T2WI+DWI+CTpI combination was significantly better than that of T2WI alone for prostate carcinoma (P < 0.001). The diagnostic value of CTpI was similar to that of T2WI+DWI in combination. There were statistically significant differences in the blood flow and permeability surface values between prostate carcinoma and background prostate on CTp images. CTp may be a valuable tool for detecting prostate carcinoma and may be preferred in cases where MRI is contraindicated. If this technique is combined with T2WI and DWI, its diagnostic value is enhanced. (orig.)

  12. Improved attenuation correction for respiratory gated PET/CT with extended-duration cine CT: a simulation study

    Science.gov (United States)

    Zhang, Ruoqiao; Alessio, Adam M.; Pierce, Larry A.; Byrd, Darrin W.; Lee, Tzu-Cheng; De Man, Bruno; Kinahan, Paul E.

    2017-03-01

    Due to the wide variability of intra-patient respiratory motion patterns, traditional short-duration cine CT used in respiratory gated PET/CT may be insufficient to match the PET scan data, resulting in suboptimal attenuation correction that eventually compromises the PET quantitative accuracy. Thus, extending the duration of cine CT can be beneficial to address this data mismatch issue. In this work, we propose to use a long-duration cine CT for respiratory gated PET/CT, whose cine acquisition time is ten times longer than a traditional short-duration cine CT. We compare the proposed long-duration cine CT with the traditional short-duration cine CT through numerous phantom simulations with 11 respiratory traces measured during patient PET/CT scans. Experimental results show that, the long-duration cine CT reduces the motion mismatch between PET and CT by 41% and improves the overall reconstruction accuracy by 42% on average, as compared to the traditional short-duration cine CT. The long-duration cine CT also reduces artifacts in PET images caused by misalignment and mismatch between adjacent slices in phase-gated CT images. The improvement in motion matching between PET and CT by extending the cine duration depends on the patient, with potentially greater benefits for patients with irregular breathing patterns or larger diaphragm movements.

  13. [Deciduous dentition: anatomical study by μ-CT].

    Science.gov (United States)

    Bossù, Maurizio; Valletta, Alessandra; Fiore, Roberto; Riccitiello, Francesco; D'Amora, Marilina; Coppolino, Francesco; Simeone, Michele; Polimeni, Antonella

    2013-01-01

    Endodontics is the branch of deciduous teeth pediatric dentistry that deals with the treatment of the root canal system. The goal of therapy is to maintain as long as possible the element in the dental arch to prevent alterations of orthognathodontic, infectious, and functional history and eruptive sequence. Although manual instrumentation has been widely used and still preferred by some practitioners, has limitations that affect the actual ability to clean the channel, the ability to create steps, perforations, dentinal plugs and fractures of the instrument. On the other hand, the disadvantages are the high cost of the instruments in nickel-titanium, which must be frequently replaced, and the risk of compromising the stability of the tooth due to an excessive consumption of dentinal tissue. The use of computed microtomography (μCT) of extracted elements has a considerable advantage in the study of dental hard tissues. The purpose of this study was to analyze the anatomy of the endodontic system of the elements deciduous.

  14. Substitute CT generation from a single ultra short time echo MRI sequence: preliminary study

    Science.gov (United States)

    Ghose, Soumya; Dowling, Jason A.; Rai, Robba; Liney, Gary P.

    2017-04-01

    In MR guided radiation therapy planning both MR and CT images for a patient are acquired and co-registered to obtain a tissue specific HU map. Generation of the HU map directly from the MRI would eliminate the CT acquisition and may improve radiation therapy planning. In this preliminary study of substitute CT (sCT) generation, two porcine leg phantoms were scanned using a 3D ultrashort echo time (PETRA) sequence and co-registered to corresponding CT images to build tissue specific regression models. The model was created from one co-registered CT-PETRA pair to generate the sCT for the other PETRA image. An expectation maximization based clustering was performed on the co-registered PETRA image to identify the soft tissues, dense bone and air class membership probabilities. A tissue specific non linear regression model was built from one registered CT-PETRA pair dataset to predict the sCT of the second PETRA image in a two-fold cross validation schema. A complete substitute CT is generated in 3 min. The mean absolute HU error for air was 0.3 HU, bone was 95 HU, fat was 30 HU and for muscle it was 10 HU. The mean surface reconstruction error for the bone was 1.3 mm. The PETRA sequence enabled a low mean absolute surface distance for the bone and a low HU error for other classes. The sCT generated from a single PETRA sequence shows promise for the generation of fast sCT for MRI based radiation therapy planning.

  15. Comparison of spectral CT imaging methods based a photon-counting detector: Experimental study

    Science.gov (United States)

    Lee, Youngjin; Lee, Seungwan; Kim, Hee-Joung

    2016-04-01

    Photon-counting detectors allow spectral computed tomography (CT) imaging using energy-resolved information from a polychromatic X-ray spectrum. The spectral CT images based on the photon-counting detectors are dependent on the energy ranges defined by energy bins for image acquisition. In this study, K-edge and energy weighting imaging methods were experimentally implemented by using a spectral CT system with a cadmium zinc telluride (CZT)-based photon-counting detector. The spectral CT images were obtained by various energy bins and compared in terms of CNR improvement for investigating the effect of energy bins and the efficiency of the spectral CT imaging methods. The results showed that the spectral CT image quality was improved by using the particular energy bins, which were optimized for each spectral CT imaging method and target material. The CNR improvement was different for the spectral CT imaging methods and target materials. It can be concluded that an appropriate selection of imaging method for each target material and the optimization of energy bin can maximize the quality of spectral CT images.

  16. Comparison of spectral CT imaging methods based a photon-counting detector: Experimental study

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Youngjin [Department of Radiological Science, College of Health Science, Eulji University, 553 Sangseong-daero, Seongnam, Gyeonggi-do 461-713 (Korea, Republic of); Lee, Seungwan, E-mail: slee1@konyang.ac.kr [Department of Radiological Science, College of Medical Science, Konyang University, 158 Gwanjeodong-ro, Daejeon 302-812 (Korea, Republic of); Kim, Hee-Joung [Department of Radiological Science, College of Health Science, Yonsei University, 1 Yonseidae-gil, Wonju, Kangwon-do 220-710 (Korea, Republic of)

    2016-04-11

    Photon-counting detectors allow spectral computed tomography (CT) imaging using energy-resolved information from a polychromatic X-ray spectrum. The spectral CT images based on the photon-counting detectors are dependent on the energy ranges defined by energy bins for image acquisition. In this study, K-edge and energy weighting imaging methods were experimentally implemented by using a spectral CT system with a cadmium zinc telluride (CZT)-based photon-counting detector. The spectral CT images were obtained by various energy bins and compared in terms of CNR improvement for investigating the effect of energy bins and the efficiency of the spectral CT imaging methods. The results showed that the spectral CT image quality was improved by using the particular energy bins, which were optimized for each spectral CT imaging method and target material. The CNR improvement was different for the spectral CT imaging methods and target materials. It can be concluded that an appropriate selection of imaging method for each target material and the optimization of energy bin can maximize the quality of spectral CT images.

  17. CT Colonographic Screening of Patients With a Family History of Colorectal Cancer: Comparison With Adults at Average Risk and Implications for Guidelines.

    Science.gov (United States)

    Pickhardt, Perry J; Mbah, Ifeanyi; Pooler, B Dustin; Chen, Oliver T; Hinshaw, J Louis; Weiss, Jennifer M; Kim, David H

    2017-04-01

    The purposes of this study were to compare rates of lesion detection at CT colonographic (CTC) screening of adults without symptoms who had and who did not have a family history of colorectal cancer according to American Cancer Society guidelines and to consider the clinical implications. Over 134 months, consecutively registered CTC cohorts of adults without symptoms who had (n = 156; 88 [56.4%] women; 68 [43.6%] men; mean age, 56.3 years) and who did not have (n = 8857; 4757 [53.7%] women; 4100 [46.3%] men; mean age, 56.6 years) an American Cancer Society-defined family history of colorectal cancer (first-degree relative with diagnosis before age 60 years or two first-degree relatives with diagnosis at any age) were compared for relevant colorectal findings. For the family history versus no family history cohorts, the frequency of all nondiminutive polyps (≥ 6 mm) reported at CTC was 23.7% versus 15.5% (p = 0.007); small polyps (6-9 mm), 13.5% versus 9.1% (p = 0.068); and large polyps (≥ 10 mm), 10.2% versus 6.5% (p = 0.068). The rate of referral for colonoscopy was greater for the family history cohort (16.0% vs 10.5%; p = 0.035). However, the frequencies of proven advanced adenoma (4.5% vs 3.2%; p = 0.357), nonadvanced adenoma (5.1% vs 2.6%; p = 0.070), and cancer (0.0% vs 0.4%; p = 0.999) were not significantly increased. The difference in positive rates between the two cohorts (11.5% vs 4.3%; p colorectal cancer relevance, such as small hyperplastic polyps, diverticular disease, and false-positive CTC findings. Although the overall CTC-positive and colonoscopy referral rates were higher in the family history cohort, the clinically relevant frequencies of advanced neoplasia and cancer were not sufficiently increased to preclude CTC screening. These findings support the use of CTC as a front-line screening option in adults with a family history of colorectal cancer.

  18. WE-FG-207A-01: Introduction to Dedicated Breast CT - Early Studies.

    Science.gov (United States)

    Vedantham, S

    2016-06-01

    Mammography-based screening has been a valuable imaging tool for the early detection of non-palpable lesions and has contributed to significant reduction in breast cancer associated mortality. However, the breast imaging community recognizes that mammography is not ideal, and in particular is inferior for women with dense breasts. Also, the 2-D projection of a 3-D organ results in tissue superposition contributing to false-positives. The sensitivity of mammography is breast-density dependent. Its sensitivity, especially in dense breasts, is low due to overlapping tissue and the fact that normal breast tissue, benign lesions and breast cancers all have similar "densities", making lesion detection more difficult. We ideally need 3-D imaging for imaging the 3-D breast. MRI is 3-D, whole breast ultrasound is 3-D, digital breast tomosynthesis is called 3-D but is really "pseudo 3-D" due to poor resolution along the depth-direction. Also, and importantly, we need to be able to administer intravenous contrast agents for optimal imaging, similar to other organ systems in the body. Dedicated breast CT allows for 3-D imaging of the uncompressed breast. In current designs, the patient is positioned prone on the table and the breast is pendant through an aperture and the scan takes approximately 10 seconds [O'Connell et al., AJR 195: 496-509, 2010]. Almost on the heels of the invention of CT itself, work began on the development of dedicated breast CT. These early breast CT systems were used in clinical trials and the results from comparative performance evaluation of breast CT and mammography for 1625 subjects were reported in 1980 [Chang et al., Cancer 46: 939-46, 1980]. However, the technological limitations at that time stymied clinical translation for decades. Subsequent to the landmark article in 2001 [Boone et al., Radiology 221: 657-67, 2001] that demonstrated the potential feasibility in terms of radiation dose, multiple research groups are actively investigating

  19. Early Cerebral Circulation Disturbance in Patients Suffering from Severe Traumatic Brain Injury (TBI): A Xenon CT and Perfusion CT Study

    Science.gov (United States)

    HONDA, Mitsuru; ICHIBAYASHI, Ryo; YOKOMURO, Hiroki; YOSHIHARA, Katsunori; MASUDA, Hiroyuki; HAGA, Daisuke; SEIKI, Yoshikatsu; KUDOH, Chiaki; KISHI, Taichi

    2016-01-01

    Traumatic brain injury (TBI) is widely known to cause dynamic changes in cerebral blood flow (CBF). Ischemia is a common and deleterious secondary injury following TBI. Detecting early ischemia in TBI patients is important to prevent further advancement and deterioration of the brain tissue. The purpose of this study was to clarify the cerebral circulatory disturbance during the early phase and whether it can be used to predict patient outcome. A total of 90 patients with TBI underwent a xenon-computed tomography (Xe-CT) and subsequently perfusion CT to evaluate the cerebral circulation on days 1–3. We measured CBF using Xe-CT and mean transit time (MTT: the width between two inflection points [maximum upward slope and maximum downward slope from inflow to outflow of the contrast agent]) using perfusion CT and calculated the cerebral blood volume (CBV) using the AZ-7000W98 computer system. The relationships of the hemodynamic parameters CBF, MTT, and CBV to the Glasgow Coma Scale (GCS) score and the Glasgow Outcome Scale (GOS) score were examined. There were no significant differences in CBF, MTT, and CBV among GCS3–4, GCS5–6, and GCS7–8 groups. The patients with a favorable outcome (GR and MD) had significantly higher CBF and lower MTT than those with an unfavorable one (SD, VS, or D). The discriminant analysis of these parameters could predict patient outcome with a probability of 70.6%. During the early phase, CBF reduction and MTT prolongation might influence the clinical outcome of TBI. These parameters are helpful for evaluating the severity of cerebral circulatory disturbance and predicting the outcome of TBI patients. PMID:27356957

  20. Early Cerebral Circulation Disturbance in Patients Suffering from Severe Traumatic Brain Injury (TBI): A Xenon CT and Perfusion CT Study.

    Science.gov (United States)

    Honda, Mitsuru; Ichibayashi, Ryo; Yokomuro, Hiroki; Yoshihara, Katsunori; Masuda, Hiroyuki; Haga, Daisuke; Seiki, Yoshikatsu; Kudoh, Chiaki; Kishi, Taichi

    2016-08-15

    Traumatic brain injury (TBI) is widely known to cause dynamic changes in cerebral blood flow (CBF). Ischemia is a common and deleterious secondary injury following TBI. Detecting early ischemia in TBI patients is important to prevent further advancement and deterioration of the brain tissue. The purpose of this study was to clarify the cerebral circulatory disturbance during the early phase and whether it can be used to predict patient outcome. A total of 90 patients with TBI underwent a xenon-computed tomography (Xe-CT) and subsequently perfusion CT to evaluate the cerebral circulation on days 1-3. We measured CBF using Xe-CT and mean transit time (MTT: the width between two inflection points [maximum upward slope and maximum downward slope from inflow to outflow of the contrast agent]) using perfusion CT and calculated the cerebral blood volume (CBV) using the AZ-7000W98 computer system. The relationships of the hemodynamic parameters CBF, MTT, and CBV to the Glasgow Coma Scale (GCS) score and the Glasgow Outcome Scale (GOS) score were examined. There were no significant differences in CBF, MTT, and CBV among GCS3-4, GCS5-6, and GCS7-8 groups. The patients with a favorable outcome (GR and MD) had significantly higher CBF and lower MTT than those with an unfavorable one (SD, VS, or D). The discriminant analysis of these parameters could predict patient outcome with a probability of 70.6%. During the early phase, CBF reduction and MTT prolongation might influence the clinical outcome of TBI. These parameters are helpful for evaluating the severity of cerebral circulatory disturbance and predicting the outcome of TBI patients.

  1. Can nontriggered thoracic CT be used for coronary artery calcium scoring? A phantom study

    NARCIS (Netherlands)

    Xie, Xueqian; Greuter, Marcel J. W.; Groen, Jaap M.; de Bock, Geertruida H.; Oudkerk, Matthijs; de Jong, Pim A.; Vliegenthart, Rozemarijn

    2013-01-01

    Purpose: Coronary artery calcium score, traditionally based on electrocardiography (ECG)-triggered computed tomography (CT), predicts cardiovascular risk. However, nontriggered CT is extensively utilized. The study-purpose is to evaluate the in vitro agreement in coronary calcium score between nontr

  2. Multislice CT brain image registration for perfusion studies

    Science.gov (United States)

    Lin, Zhong Min; Pohlman, Scott; Chandra, Shalabh

    2002-04-01

    During the last several years perfusion CT techniques have been developed as an effective technique for clinically evaluating cerebral hemodynamics. Perfusion CT techniques are capable of measurings functional parameters such as tissue perfusion, blood flow, blood volume, and mean transit time and are commonly used to evaluate stroke patients. However, the quality of functional images of the brain frequently suffers from patient head motion. Because the time window for an effective treatment of stroke patient is narrow, a fast motion correction is required. The purpose of the paper is to present a fast and accurate registration technique for motion correction of multi-slice CT and to demonstrate the effects of the registration on perfusion calculation.

  3. PET-CT og kolorektal cancer - retrospektivt studie

    DEFF Research Database (Denmark)

    Larsen, Anders Christian; Julie, Pedersen; Prakash, Vineet

    udredningen af primært metastaserende cancer. Patienterne henvises til PET-CT, når der klinisk rejses mistanke om recidiv i form af symptomer eller biokemiske markørstigninger. Alternativt, hvis CT- og MRscanning ikke kan afklare problemstillingen. På nuværende tidspunkt er der ingen klare retningslinjer for...... radioaktiviteten af 18F-FDG i et givent punkt på et bestemt tidspunkt sat i forhold til baggrunds FDG optagelsen i kroppens organer. PET integreres med CT-scanningen på standard software. Den samlede beskrivelse er i nærværende materiale sammenholdt med kliniske data. Patientmateriale: I perioden 1/9 2006 til 1...

  4. Histoplasmosis of the adrenal glands studied by CT

    Energy Technology Data Exchange (ETDEWEB)

    Wilson, D.A.; Muchmore, H.G.; Tisdal, R.G.; Fahmy, A.; Pitha, J.V.

    1984-03-01

    Computed tomography (CT) of the adrenal glands was performed on seven patients who had histologically proved disseminated histoplasmosis. All seven patients showed some degree of adrenal gland abnormality. The range of CT findings included minimal enlargement with faint flecks of calcium, moderate enlargement with focal low attenuation nodules, and massive enlargement with large areas of necrosis or dense calcification. The changes in each patient were bilateral and symmetrical. Adrenal gland shape was usually preserved. Finding of percutaneous adrenal biopsy, which was performed under CT guidance, made the diagnosis in one patient. Five of seven patients had adrenal insufficiency. It is concluded that the diagnosis of disseminated histoplasmosis should be considered in any patient who has bilateral adrenal gland enlargement and who resides in an endemic area, especially if there is evidence of adrenal insufficiency.

  5. Detection performance study for cone-beam differential phase contrast CT

    Science.gov (United States)

    Li, Ke; Bevins, Nicholas; Zambelli, Joseph; Qi, Zhihua; Chen, Guang-Hong

    2012-03-01

    X-ray phase sensitive imaging methods have seen tremendous growth and increased interest in recent years. Each method has its advantages and disadvantages, but all have shown the ability to improve the detection of various objects because of the additional phase measurements. Of the various methods, grating-based differential phase contrast computed tomography (DPC-CT) imaging has shown greater quantitative and diagnostic capabilities than traditional absorption CT. Although it has been shown that DPC-CT provides superior contrast of certain materials, one question has not been fully addressed to date is whether DPC-CT can provide improved accuracy in detecting low contrast masses using the same radiation dose as that given in absorption CT. The detectability is not only related to contrast to noise ratio, but also to the noise texture. The purpose of this study is to investigate how the peculiar noise texture found in cone-beam DPC-CT affects low contrast objects' detectability through human observer ROC analysis. Studies for both axial and sagittal planes were carried out, as both could potentially be used in clinical practice for a 3D image. The results demonstrate that noise texture found in conebeam DPC-CT strongly affects human visual perception, and that object detectabilities in axial and sagittal images of DPC-CT are different.

  6. Potential cancer risk associated to CT scan. State of the art of epidemiological studies

    Energy Technology Data Exchange (ETDEWEB)

    Bernier, Marie-Odile; Baysson, Neige Joumy Helene; Jacob, Sophie; Laurier, Dominique [Institute for Radiological Protection and Nuclear Safety (IRSN), Fontenay-aux-Roses (France). Lab. of Epidemiology

    2013-07-01

    Introduction: The increasing use of computed tomography (CT) scans in paediatric population raises the question of a possible health impact of ionizing radiation exposure associated with CT scans. Material and methods: Two large cohort studies have been recently published that assessed the risk of cancer related to CT examinations of children and young adults. Methodology and results of these studies are presented. Results: The UK cohort included over 176,000 young people, who underwent one or more CT scans between 1985 and 2002. The Australian study compared the risk of cancer and leukaemia in a population of 680,000 young people exposed to CT scans between 1985 and 2005 to non-exposed similar age people. Both studies showed a significant dose-response relation between exposure to CT and leukaemia or brain tumour risks. These results are consistent with predictions from A-bomb survivors' data. However, uncertainties in dosimetric estimation and potential bias linked to underlying medical conditions should be considered. Conclusion and perspectives: Further studies with more accurate dosimetry and assessment of potential bias and uncertainties are needed. Ongoing national studies and the European collaborative EPI-CT study will help to better understand the relation between low level radiation exposure and cancer and to support recommendations for patients'' radiation protection. (orig.)

  7. Clinical investigation of flat panel CT following middle ear reconstruction: a study of 107 patients

    Energy Technology Data Exchange (ETDEWEB)

    Zaoui, K. [University Hospital Heidelberg, Ruprecht Karls University, Department of Otorhinolaryngology, Head and Neck Surgery, Heidelberg (Germany); Kromeier, J. [St. Josefs Hospital, RkK, Department of Radiology, Freiburg (Germany); Neudert, M.; Beleites, T.; Zahnert, T. [University Hospital Dresden, Technical University, Department of Otorhinolaryngology, Head and Neck Surgery, Dresden (Germany); Laszig, R.; Offergeld, C. [University Hospital Freiburg, Albert Ludwigs University, Department of Otorhinolaryngology, Head and Neck Surgery, Freiburg (Germany)

    2014-03-15

    After middle ear reconstruction using partial or total ossicular replacement prostheses (PORP/TORP), an air-bone gap (ABG) may persist because of prosthesis displacement or malposition. So far, CT of the temporal bone has played the main role in the diagnosis of reasons for postoperative insufficient ABG improvement. Recent experimental and clinical studies have evaluated flat panel CT (fpCT) as an alternative imaging technique that provides images with high isovolumetric resolution, fewer metal-induced artefacts and lower irradiation doses. One hundred and seven consecutive patients with chronic otitis media with or without cholesteatoma underwent reconstruction by PORP (n = 52) or TORP (n = 55). All subjects underwent preoperative and postoperative audiometric testing and postoperative fpCT. Statistical evaluation of all 107 patients as well as the sole sub-assembly groups (PORP or TORP) showed a highly significant correlation between hearing improvement and fpCT-determined prosthesis position. FpCT enables detailed postoperative information on patients with middle ear reconstruction. FpCT is a new imaging technique that provides immediate feedback on surgical results after reconstructive middle ear surgery. Specific parameters evaluated by fpCT may serve as a predictive tool for estimated postoperative hearing improvement. Therefore this imaging technique is suitable for postoperative quality control in reconstructive middle ear surgery. (orig.)

  8. Terminate lung cancer (TLC) study-A mixed-methods population approach to increase lung cancer screening awareness and low-dose computed tomography in Eastern Kentucky.

    Science.gov (United States)

    Cardarelli, Roberto; Reese, David; Roper, Karen L; Cardarelli, Kathryn; Feltner, Frances J; Studts, Jamie L; Knight, Jennifer R; Armstrong, Debra; Weaver, Anthony; Shaffer, Dana

    2017-02-01

    For low dose CT lung cancer screening to be effective in curbing disease mortality, efforts are needed to overcome barriers to awareness and facilitate uptake of the current evidence-based screening guidelines. A sequential mixed-methods approach was employed to design a screening campaign utilizing messages developed from community focus groups, followed by implementation of the outreach campaign intervention in two high-risk Kentucky regions. This study reports on rates of awareness and screening in intervention regions, as compared to a control region.

  9. Study of the Active Screen Plasma Nitriding

    Institute of Scientific and Technical Information of China (English)

    Zhao Cheng; C. X. Li; H. Dong; T. Bell

    2004-01-01

    Active screen plasma nitriding (ASPN) is a novel nitriding process, which overcomes many of the practical problems associated with the conventional DC plasma nitriding (DCPN). Experimental results showed that the metallurgical characteristics and hardening effect of 722M24 steel nitrided by ASPN at both floating potential and anodic (zero) potential were similar to those nitrided by DCPN. XRD and high-resolution SEM analysis indicated that iron nitride particles with sizes in sub-micron scale were deposited on the specimen surface in AS plasma nitriding. These indicate that the neutral iron nitride particles, which are sputtered from the active screen and transferred through plasma to specimen surface, are considered to be the dominant nitrogen carder in ASPN. The OES results show that NH could not be a critical species in plasma nitriding.

  10. Randomized studies of PSA screening: an opinion

    Institute of Scientific and Technical Information of China (English)

    Oliver Sartor

    2011-01-01

    @@ The issue of prostate cancer screening with prostate-specific antigen (PSA) has been contentious for nearly two decades due to lack of data from randomized trials, but that has now changed.A brief review of the available data is warranted as there is finally some clarity on this critically important topic.Knowing what to ignore, as well as what to focus on, is critical for understanding the current data.

  11. Quality control within the multicentre perfusion CT study of primary colorectal cancer (PROSPeCT): results of an iodine density phantom study

    Energy Technology Data Exchange (ETDEWEB)

    Lewis, Maria; Honey, Ian [Trust, Medical Physics Department, Guy' s and St. Thomas' NHS Foundation, London (United Kingdom); Goh, Vicky [King' s College London, St Thomas' Hospital, Division of Imaging Sciences and Biomedical Engineering, London (United Kingdom); Beggs, Shaun [Bradford Teaching Hospitals NHS Foundation Trust, Radiation Physics Services, Bradford (United Kingdom); Bridges, Andrew; Wayte, Sarah [Radiology Physics University Hospitals Coventry and Warwickshire NHS Trust, Coventry (United Kingdom); Clewer, Philip [Medical Physics Department, University Hospital Southampton NHS Foundation Trust, Southampton (United Kingdom); Davis, Anne [Portsmouth Hospitals NHS Trust, Medical Physics Department, Portsmouth (United Kingdom); Foy, Trevelyan [Royal Cornwall Hospital NHS Trust, Medical Physics Department, Truro (United Kingdom); Fuller, Karen [Sheffield Teaching Hospitals NHS Foundation Trust, Medical Physics Department, Sheffield (United Kingdom); George, Jennifer [University Hospital of North Staffordshire NHS Trust, Medical Physics Department, Stoke-on-Trent (United Kingdom); Higginson, Antony [Portsmouth Hospitals NHS Trust, Department of Radiology, Portsmouth (United Kingdom); Iball, Gareth [Leeds Teaching Hospitals NHS Trust, Department of Medical Physics and Engineering, Leeds (United Kingdom); Mutch, Steve [Oxford University Hospitals NHS Trust, Radiation Physics and Protection Department, Oxford (United Kingdom); Neil, Shellagh; Sutton, David [NHS Tayside, Medical Physics Department, Dundee, Scotland (United Kingdom); Rivett, Cat [Plymouth Hospitals NHS Trust, Clinical and Radiation Physics, Plymouth (United Kingdom); Slater, Andrew [Oxford University Hospitals NHS Trust, Department of Radiology, Oxford (United Kingdom); Weir, Nick [Queen' s Medical Research Institute, Clinical Research Imaging Centre, Edinburgh, Scotland (United Kingdom); Collaboration: on behalf of the PROSPeCT Investigators

    2014-09-15

    To assess the cross-centre consistency of iodine enhancement, contrast-to-noise ratio and radiation dose in a multicentre perfusion CT trial of colorectal cancer. A cylindrical water phantom containing different iodine inserts was examined on seven CT models in 13 hospitals. The relationship between CT number (Hounsfield units, HU) and iodine concentration (milligrams per millilitre) was established and contrast-to-noise ratios (CNRs) calculated. Radiation doses (CTDI{sub vol}, DLP) were compared across all sites. There was a linear relationship between CT number and iodine density. Iodine enhancement varied by a factor of at most 1.10, and image noise by at most 1.5 across the study sites. At an iodine concentration of 1 mg ml{sup -1} and 100 kV, CNRs ranged from 3.6 to 4.8 in the 220-mm phantom and from 1.4 to 1.9 in the 300-mm phantom. Doses varied by a factor of at most 2.4, but remained within study dose constraints. Iterative reconstruction algorithms did not alter iodine enhancement but resulted in reduced image noise by a factor of at most 2.2, allowing a potential dose decrease of at most 80 % compared to filtered back projection (FBP). Quality control of CT performance across centres indicates that CNR values remain relatively consistent across all sites, giving acceptable image quality within the agreed dose constraints. (orig.)

  12. A single institution study of radiation dose received from CT imaging: A comparison to Malaysian NDRL

    Science.gov (United States)

    Osman, N. D.; Shamsuri, S. B. M.; Tan, Y. W.; Razali, M. A. S. M.; Isa, S. M.

    2017-05-01

    Advancement of CT technology has led to an increase in CT scanning as it improves the diagnosis. However, it is important to assess health risk of patients associated with ionising radiation received from CT. This study evaluated current dose distributions at Advanced Medical and Dental Institute (AMDI), Malaysia and was used to establish Local Diagnostic Reference Level (LDRL). Dose indicators such as CT Dose Index (CTDIvol and CTDIw) and Dose-Length Product (DLP) were gathered for all routine CT examinations performed at the Imaging Unit, AMDI from January 2015 to June 2016. The first and third quartile values for each dose indicator were determined. A total of 364 CT studies were performed during that period with the highest number of cases being Thorax-Abdomen-Pelvis (TAP) study (57% of total study). The CTDIw ranged between 2.0 mGy to 23.4 mGy per procedure. DLP values were ranged between 94 mGy.cm to 1687 mGy.cm. The local dose data was compared with the national DRL to monitor the current CT practice at AMDI and LDRL will be established from the calculated third quartile values of dose distribution. From the results, some of the local dose values exceeded the Malaysian and further evaluation is important to ensure the dose optimisation for patients.

  13. Improving the false-negative rate of CT in acute appendicitis-Reassessment of CT images by body imaging radiologists: A blinded prospective study

    Energy Technology Data Exchange (ETDEWEB)

    Poortman, Pieter [Department of Surgery, St Elisabeth Hospital, Tilburg (Netherlands)], E-mail: ppoortman@wlz.nl; Lohle, Paul N.M. [Department of Surgery, St Elisabeth Hospital, Tilburg (Netherlands)], E-mail: plohle@elisabeth.nl; Schoemaker, Cees M. [Department of Surgery, St Elisabeth Hospital, Tilburg (Netherlands)], E-mail: mcschoemaker@elisabeth.nl; Cuesta, Miguel A. [Department of Surgery, VU Medical Centre, Amsterdam (Netherlands)], E-mail: ma.cuesta@vumc.nl; Oostvogel, Henk J.M. [Department of Surgery, St Elisabeth Hospital, Tilburg (Netherlands)], E-mail: h.oostvogel@elisabeth.nl; Lange-de Klerk, Elly S.M. de [Department of Epidemiology and Biostatistics, VU Medical Centre, Amsterdam (Netherlands)], E-mail: esm.delange@vumc.nl; Hamming, Jaap F. [Department of Surgery, Leiden University Medical Centre (Netherlands)], E-mail: j.f.hamming@lumc.nl

    2010-04-15

    Purpose: To compare the accuracy of computed tomography (CT) analyzed by individual radiology staff members and body imaging radiologists in a non-academic teaching hospital for the diagnosis of acute appendicitis. Patients and methods: In a prospective study 199 patients with suspected acute appendicitis were examined with unenhanced CT. CT images were pre-operatively analyzed by one of the 12 members of the radiology staff. In a later stage two body imaging radiologist reassessed all CT images without knowledge of the surgical findings and without knowledge of the primary CT diagnosis. The results, independently reported, were correlated with surgical and histopathologic findings. Results: In 132 patients (66%) acute appendicitis was found at surgery, in 67 patients (34%) a normal appendix was found. The sensitivity of the primary CT analysis and of the reassessment was 76% and 88%, respectively; the specificity was 84% and 87%; the positive predictive value was 90% and 93%; the negative predictive value was 64% and 78%; and the accuracy was 78% and 87%. Conclusion: Reassessment of CT images for acute appendicitis by body imaging radiologists results in a significant improvement of sensitivity, negative predictive value and accuracy. To prevent false-negative interpretation of CT images in acute appendicitis the expertise of the attending radiologist should be considered.

  14. Comparative study on developmental stages of the clavicle by postmortem MRI and CT imaging

    DEFF Research Database (Denmark)

    Larsen, Sara Tangmose; Lynnerup, Niels; Jensen, K.E.

    2013-01-01

    Objectives: The developmental stages of the clavicles are important for forensic age estimation purposes in adolescents. This study compares the 4-stage system to evaluate the ossification of the medial end of the clavicle as visualized by magnetic resonance imaging (MRI) and computed tomography...... (CT). As several forensic institutes routinely perform CT scans, the large amount of available data may serve as reference sample for MRI in specific cases. Material and methods: This prospective study included an MRI and CT scan of 47 autopsy cases performed prior to medico-legal autopsy (age range...

  15. A STUDY OF CORRELATION BETWEEN NASAL ENDOSCOPY AND CT SCAN IN CASES OF CHRONIC RHINOSINUSITIS

    Directory of Open Access Journals (Sweden)

    Arun Kumar

    2015-07-01

    Full Text Available BACKGROUND: The accurate diagnosis of Chronic Rhinosinusitis (CRS is still a challenge therefore, the American Academy of Otorhinolaryngology - Head and Neck Surgery (AAO - HNS 1 has met in a multidisciplinary encounter and formulated a consensus based on only clinical symptoms. The computed tomography (CT scan and the nasal endoscopy (NE were introduced to make an accurate diagnosis of CRS and verify the disease severity. AIM: The aim of this study is to make a correlation between nasal endoscopy and CT scan in cases of clinically diagnosed Chronic Rhinosinusitis patients. METHOD: A study was carried out on 90 patients at Jhalawar Medical College, Jhalawar (Raj. during Sept. 20 12 to Dec. 2014. Diagnostic Nasal Endoscopy and CT Scan PNS done in patients, suffering from Chronic Rhinosinusitis. As a classification instruments, Metson / Gliklich's classification was used to evaluate the tomographic diagnosis and the Stankiewicz / Chow' s classification to evaluate the endoscopic diagnosis of Chronic Rhinosinusitis. RESULTS: Our study showed high specificity of endoscopy in comparison to CT scan though CT scan results are more sensitive. CONCLUSION: Endoscopy can confirm a Chronic Rhinosi nusitis diagnosis, but cannot rule it out, and that CT should be performed in cases of suspected CRS even if mucopurulence is not noted on endoscopy. The CT scan and the nasal endoscopy making easier the treatment planning and the disease resolution.

  16. Abdominal and Pelvic CT

    Medline Plus

    Full Text Available ... CT Scanning of the Abdomen and Pelvis? What is CT Scanning of the Abdomen/Pelvis? Computed tomography, ... the body being studied. top of page How is the CT scan performed? The technologist begins by ...

  17. Adherence to follow-up CT scans in patients with small pulmonary nodules, a retrospective study

    DEFF Research Database (Denmark)

    Johansson, Sofie Lock; Gerner Hansen, Niels-Christian

    2010-01-01

    Adherence to follow-up CT scans in patients with small pulmonary nodules, a retrospective study The Danish National guidelines have since 2008 suggested serial follow-up CT scans at 3, 6, 12, and 24 months for nodules between 5 and 10 mm and at 12 and 24 months for nodules less than 5 mm in accor...... is that management of the follow-up of small nodules did improve in 2008-2009, but adherence to the guidelines was still limited. We will now implement a prospective program for monitoring the adherence to the follow-up CTs.......Adherence to follow-up CT scans in patients with small pulmonary nodules, a retrospective study The Danish National guidelines have since 2008 suggested serial follow-up CT scans at 3, 6, 12, and 24 months for nodules between 5 and 10 mm and at 12 and 24 months for nodules less than 5 mm...... in the four year period 2006-2009. In 72 cases, 19 in 2006-2007 and 51 in 2008-2009, one or more small nodules, with diameter ≤ 10 mm, were detected on CT in patients with no known recent malignant disease. For these patients follow-up was suggested, either with CT or PET-CT. One of the 70 patients from 2008...

  18. CT colonography. A guide for clinical practice

    Energy Technology Data Exchange (ETDEWEB)

    Mang, Thomas [Medical Univ. of Vienna (Austria). Dept. of Radiology; Schima, Wolfgang [Krankenhaus Goettlicher Heiland, Wien (Austria). Dept. of Diagnostic and Interventional Radiology; Krankenhaus der Barmherzigen Schwestern, Wien (Austria); Sankt-Josef-Krankenhaus, Wien (Austria)

    2013-07-01

    The book on CT colonography - a guide for clinical practice - covers the following issues: indications and contraindications, examination; Image interpretation; findings at CT colonography, how to generate a useful report, screening, how to train for CT colonography.

  19. Accuracy of combined PET/CT in image-guided interventions of liver lesions: An ex-vivo study

    Institute of Scientific and Technical Information of China (English)

    Patrick Veit; Christiane Kuehle; Thomas Beyer; Hilmar Kuehl; Andreas Bockisch; Gerald Antoch

    2006-01-01

    AIM: Positioning of interventional devices in liver lesions is a challenging task if only CT is available. We investigated the potential benefit of combined PET/CT images for localization of interventional devices in interventional liver studies.METHODS: Thirty lesions each of hyperdense, isodense and hypodense attenuation compared to normal liver parenchyma were injected into 15 ex-vivo pig livers. All lesions were composed of the same amounts of gelatine containing 0.5 MBq of 18F-FDG. Following lesion insertion, an interventional needle was placed in each lesion under CT-guidance solely. After that, a PET/CT study was performed. The localization of the needle within the lesion was assessed for CT alone and PET/CT and the root mean square (RMS) was calculated. Results were compared with macroscopic measurements after lesion dissection serving as the standard of reference. RESULTS: In hypo- and isodense lesions PET/CT proved more accurate in defining the position of the interventional device when compared with CT alone. The mean RMS for CT and PET/CT differed significantly in isodense and hypodense lesions. No significant difference was found for hyperdense lesions.CONCLUSION: Combined FDG-PET/CT imaging provides more accurate information than CT alone concerning the needle position in FDG-PET positive liver lesions.Therefore combined PET/CT might be potentially beneficial not only for localization of an interventional device,but may also be beneficial for guidance in interventional liver procedures.

  20. Your Radiologist Explains CT Colonography

    Medline Plus

    Full Text Available ... Site Index A-Z Spotlight Recently posted: Anal Cancer Facet Joint Block Video: CT of the Heart ... Therapy Video: CT of the Sinuses Video: Colorectal Cancer Screening Radiology and You Sponsored by Image/Video ...

  1. Alcohol screening in people with cognitive impairment: an exploratory study.

    Science.gov (United States)

    Randall-James, James; Wadd, Sarah; Edwards, Kim; Thake, Anna

    2015-01-01

    Alcohol misuse can coexist with and/or contribute to the development of cognitive impairment in the older adult population but continues to be underestimated and undetected in older people. This study aimed to examine the feasibility and acceptability of routine screening for alcohol misuse in a small sample of older people with cognitive impairment receiving services in memory clinics. This study employed a qualitative and exploratory design, using a convenience sample of individuals attending a memory clinic in England. Ten service users older than 65 with a diagnosis of cognitive impairment (i.e., mild cognitive impairment or dementia) took part in the study. Individuals who met inclusion criteria were invited to take part in an hour-long interview, which included the interviewer administering the alcohol screening tools. Interview transcripts were analyzed using thematic analysis. Participants were able to engage with the screening tools and could, with assistance, complete them in a collaborative and timely manner without distress. All participants reported that these tools were acceptable as part of the clinic assessment. Administering the screening tools was not time-consuming or difficult, making their use feasible within the memory clinic setting. While there were some challenges (e.g., arithmetic, recall, language problems), these challenges could be overcome with the aid of the person administering the screening tool using standardized techniques for assessment administration. Routine screening for alcohol misuse in older people with cognitive impairment receiving services in memory clinics is feasible and acceptable. The process of completing alcohol screening tools with older adults receiving services at memory clinics may increase awareness of the potential impact of alcohol on cognitive functioning and provide practitioners with an opportunity to educate service users about the ways that their drinking is affecting their memory. Several techniques to

  2. Feasibility of perfusion CT technique integrated into conventional {sup 18}FDG/PET-CT studies in lung cancer patients: clinical staging and functional information in a single study

    Energy Technology Data Exchange (ETDEWEB)

    Ippolito, Davide; Capraro, Cristina; Sironi, Sandro [University of Milano-Bicocca, School of Medicine, Milan (Italy); University of Milano-Bicocca, Department of Diagnostic Radiology, H.S. Gerardo Monza, Via Pergolesi 11, Monza, Milan (Italy); Guerra, Luca [University of Milano-Bicocca, School of Medicine, Milan (Italy); San Gerardo Hospital, Department of Nuclear Medicine and PET Unit - Molecular Bioimaging Centre, Monza (Italy); De Ponti, Elena [University of Milano-Bicocca, School of Medicine, Milan (Italy); San Gerardo Hospital, Department of Medical Physics, Monza (Italy); Messa, Cristina [University of Milano-Bicocca, School of Medicine, Milan (Italy); San Gerardo Hospital, Department of Nuclear Medicine and PET Unit - Molecular Bioimaging Centre, Monza (Italy); Tecnomed Foundation, University of Milano-Bicocca, Institute for Bioimaging and Molecular Physiology, National Research Council, Milan (Italy)

    2013-02-15

    To assess the additional functional vascular information and the relationship between perfusion measurements and glucose metabolism (SUVmax) obtained by including a perfusion CT study in a whole-body contrast-enhanced PET/CT protocol in primary lung cancer lesions. Enrolled in this prospective study were 34 consecutive patients with a biopsy-proven diagnosis of lung cancer who were referred for contrast-enhanced PET/CT staging. This prospective study was approved by our institutional review board, and informed consent was obtained from all patients. Perfusion CT was performed with the following parameters: 80 kV, 200 mAs, 30 scans during intravenous injection of 50 ml contrast agent, flow rate 5 ml/s. Another bolus of contrast medium (3.5 ml/s, 80 ml, 60-s delay) was administered to ensure a full diagnostic contrast-enhanced CT scan for clinical staging. The perfusion CT data were used to calculate a range of tumour vascularity parameters (blood flow, blood volume and mean transit time), and tumour FDG uptake (SUVmax) was used as a metabolic indicator. Quantitative and functional parameters were compared and in relation to location, histology and tumour size. The nonparametric Kruskal-Wallis rank sum test was used for statistical analysis. A cut-off value of 3 cm was used according to the TNM classification to discriminate between T1 and T2 tumours (i.e. T1b vs. T2a). There were significant perfusion differences (lower blood volumes and higher mean transit time) between tumours with diameter >30 mm and tumours with diameter <30 mm (p < 0.05; blood volume 5.6 vs. 7.1 ml/100 g, mean transit time 8.6 vs. 3.9 s, respectively). Also there was a trend for blood flow to be lower in larger lesions (p < 0.053; blood flow 153.1 vs. 98.3 ml/100 g tissue/min). Significant inverse correlations (linear regression) were found between blood volume and SUVmax in tumours with diameter >30 mm in diameter. Perfusion CT combined with PET/CT is feasible technique that may provide

  3. Temporal bone trauma: correlative study between CT findings and clinical manifestations

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jung Hee; Kim, Hyung Jin; Kim, Jae Hyoung [College of Medicine, Gyeongsang National University, Jinju (Korea, Republic of)

    1994-11-15

    To assess how accurately computed tomography (CT) can demonstrate the abnormal findings which are believed to cause the clinical signs and symptoms of hearing loss (HL), vertigo and facial paralysis (FP) in patients with temporal bone trauma. The authors studied CT scans of 39 ears in 35 patients with temporal bone trauma. CT scans were performed with 1-1.5 mm slice thickness and table incrementation. Both axial and coronal scans were obtained in 32 patients and in three patients only axial scans were obtained. We analyzed CT with special reference to the structural abnormalities of the external auditory canal, middle ear cavity, bony labyrinth, and facial nerve canal, and correlated these findings with the actual clinical signs and symptoms. As to hearing loss, we evaluated 32 ears in which pure tone audiometry or brainstem evoked response audiometry had been performed. With respect to the specific types of HL, CT accurately showed the abnormalities in 84% (16/19) in conductive HL, 100% (2/2) in sensorineural HL, and 25% (2/8) for mixed HL. When we categorized HL simply as conductive and sensorineural, assuming that mixed be the result of combined conductive and sensorineural HL, CT demonstrated the abnormalities in 89% (24/27) for conductive HL and 50% (5/10) for sensorineural HL. Concerning vertigo and FP, CT demonstrated abnormalities in 67%(4/6), and 29% (4/14), respectively. Except for conductive HL, CT seems to have a variable degree of limitation for the demonstration of the structural abnormalities resulting sensorineural HL, vertigo or facial paralysis. It is imperative to correlate the CT findings with the signs and symptoms in those clinical settings.

  4. Programmatic screening for colorectal cancer: the COLONPREV study.

    Science.gov (United States)

    Castells, Antoni; Quintero, Enrique

    2015-03-01

    The COLONPREV study is an ongoing multicenter, nationwide, randomized controlled trial aimed at evaluating the efficacy of once-only colonoscopy and biennial fecal immunochemical testing with respect to the reduction of CRC-related mortality at 10 years in average-risk colorectal cancer screening population. Following a pragmatic approach, this study may contribute to establishing the most cost-effective strategy in a programmatic, population-based setting. In this review, we report the results obtained at the first screening round, as well as others achieved in nested evaluations using the COLONPREV dataset with the aim of clarifying some controversial issues on the different strategies of colorectal cancer screening.

  5. Pulmonary actinomycosis: CT studies of diagnostic and post-treatment findings

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Su Jung; Song, Sun Wha; Bo, Seal Hwang; Park, Hyun Jin; Kim, Hyeon Sook; Kim, Ki Jun; Kim, Horrim; Park, Seog Hee [College of Medicine, the Catholic University of Korea, Uijeongbu (Korea, Republic of)

    2008-05-15

    To investigate the value of the computed tomography (CT) in the study of diagnostic and post-treatment findings of pulmonary actinomycosis. Clinical data and CT findings were retrospectively analyzed in 10 patients with histopathologically confirmed pulmonary actinomycosis. We analyzed the initial CT findings in search of patterns and distributions which suggest possible lung abnormalities and found the pleura, chest wall, and lymphadenopathy to be involved as part of the indicators of lung abnormalities. We analyzed follow-up CT findings for changes in the lungs after antibiotic therapy and recurrence after surgery. Of the 10 patients analyzed by CT for lung lesions, seven had been diagnosed with alcoholism and nine were male. The initial CTs (n = 10) indicated that all the pulmonary lesions were solitary without chest wall involvement. However, a transfissural extension was observed in 20% of the study population (n = 2). Furthermore, peripheral lung distribution and adjacent pleural thickening was observed in 70% of the study population (n = 7). Within the consolidation (n = 6) or mass (n = 4), a central low density with peripheral enhancement was seen in 70% of the study population (n = 7). A follow-up CT of the seven cases following antiobiotic therapy revealed that four cases showed minimal improvement or aggravation of their lung lesions, whereas three cases showed resolution or improvement. The improvement of the central low density was related to the improvement of consolidation or mass. Furthermore the presence of fibrosis was observed after the resolution of pulmonary lesions (n = 2). No relationship was found between the duration and response of antibiotic therapy. A follow-up CT (n = 4) subsequent to a lung resection revealed the onset of chest wall actinomycosis and a thickened pleura in one case. The results of this study highlight the value of the CT in pulmonary actinomycosis in order to diagnose and evaluate antibiotic responses, complications, or

  6. A study on the effect of CT imaging acquisition parameters on lung nodule image interpretation

    Science.gov (United States)

    Yu, Shirley J.; Wantroba, Joseph S.; Raicu, Daniela S.; Furst, Jacob D.; Channin, David S.; Armato, Samuel G., III

    2009-02-01

    Most Computer-Aided Diagnosis (CAD) research studies are performed using a single type of Computer Tomography (CT) scanner and therefore, do not take into account the effect of differences in the imaging acquisition scanner parameters. In this paper, we present a study on the effect of the CT parameters on the low-level image features automatically extracted from CT images for lung nodule interpretation. The study is an extension of our previous study where we showed that image features can be used to predict semantic characteristics of lung nodules such as margin, lobulation, spiculation, and texture. Using the Lung Image Data Consortium (LIDC) dataset, we propose to integrate the imaging acquisition parameters with the low-level image features to generate classification models for the nodules' semantic characteristics. Our preliminary results identify seven CT parameters (convolution kernel, reconstruction diameter, exposure, nodule location along the z-axis, distance source to patient, slice thickness, and kVp) as influential in producing classification rules for the LIDC semantic characteristics. Further post-processing analysis, which included running box plots and binning of values, identified four CT parameters: distance source to patient, kVp, nodule location, and rescale intercept. The identification of these parameters will create the premises to normalize the image features across different scanners and, in the long run, generate automatic rules for lung nodules interpretation independently of the CT scanner types.

  7. Changes in Physician Decision Making after CT: A Prospective Multicenter Study in Primary Care Settings.

    Science.gov (United States)

    Pandharipande, Pari V; Alabre, Claude I; Coy, David L; Zaheer, Atif; Miller, Chad M; Herring, Maurice S; Tramontano, Angela C; Dowling, Emily C; Eisenberg, Jonathan D; Ashar, Bimal H; Halpern, Elkan F; Donelan, Karen; Gazelle, G Scott

    2016-12-01

    Purpose To determine the effect of computed tomography (CT) results on physician decision making in three common clinical scenarios in primary care. Materials and Methods This research was approved by the institutional review board (IRB) and was HIPAA compliant. All physicians consented to participate with an opt-in or opt-out mechanism; patient consent was waived with IRB approval. In this prospective multicenter observational study, outpatients referred by primary care providers (PCPs) for CT evaluation of abdominal pain, hematuria, or weight loss were identified. Prior to CT, PCPs were surveyed to elicit their leading diagnosis, confidence in that diagnosis (confidence range, 0%-100%), a rule-out diagnosis, and a management plan if CT were not available. Surveys were repeated after CT. Study measures were the proportion of patients in whom leading diagnoses and management changed (PCP management vs specialist referral vs emergency department transfer), median changes in diagnostic confidence, and the proportion of patients in whom CT addressed rule-out diagnoses. Regression analyses were used to identify associations between study measures and site and participant characteristics. Specifically, logistic regression analysis was used for binary study measures (change in leading diagnosis, change in management), and linear regression analysis was used for the continuous study measure (change in diagnostic confidence). Accrual began on September 5, 2012, and ended on June 28, 2014. Results In total, 91 PCPs completed pre- and post-CT surveys in 373 patients. In patients with abdominal pain, hematuria, or weight loss, leading diagnoses changed after CT in 53% (131 of 246), 49% (36 of 73), and 57% (27 of 47) of patients, respectively. Management changed in 35% (86 of 248), 27% (20 of 74), and 54% (26 of 48) of patients, respectively. Median absolute changes in diagnostic confidence were substantial and significant (+20%, +20%, and +19%, respectively; P ≤ .001 for

  8. CT-diagnosed emphysema and prognosis of chronic airflow obstruction: a retrospective study

    OpenAIRE

    Kurashima, Kazuyoshi; Fukuda, Chiaki; Nakamoto, Keitaro; Takaku, Yotaro; Hijikata, Naoya; Hoshi, Toshiko; Kanauchi, Tetsu; Ueda, Miyuki; Takayanagi, Noboru; Sugita, Yutaka; Araki, Ryuichiro

    2013-01-01

    Objective CT-diagnosed emphysema is associated with poor prognosis in chronic obstructive pulmonary disease (COPD). Its clinical impacts on prognoses of asthma with chronic airflow obstruction (CAO) are not well known. We sought to compare mortalities and prognostic factors in COPD and asthma with CAO by the presence or absence of CT-diagnosed emphysema. Design Retrospective cohort study. Setting Referral centre hospital for respiratory disease. Participants 1272 patients aged over 40 years w...

  9. Oncological patient anxiety in imaging studies: the PET/CT example

    OpenAIRE

    Abreu, Carla; Grilo, Ana Monteiro; Lucena, Filipa; Carolino, Elisabete

    2016-01-01

    The purpose of this study was to investigate the subjective perception of anxiety pre- and post-procedure, and explore the relationship between demographic, clinical variables and cancer patients' anxiety during a positron emission tomography/computed tomography (PET/CT) scan. Two hundred and thirty-two oncological out patients, with clinical indication for performing an (18)F-2-fluoro-2-deoxy-D-glucose ((18)F-FDG) PET/CT scan and attending a nuclear medicine (NM) department, participated in ...

  10. Barriers to colorectal cancer screening: A case-control study

    Institute of Scientific and Technical Information of China (English)

    Shan-Rong Cai; Su-Zhan Zhang; Shu Zheng; Hong-Hong Zhu

    2009-01-01

    AIM:To investigate barriers to colorectal cancer (CRC) screening in a community population. METHODS:We conducted a community-based case-control study in an urban Chinese population by questionnaire. Cases were selected from those completing both a fecal occult blood test (FOBT) case and colonoscopy in a CRC screening program in 2004. Control groups were matched by gender, age group and community. Control 1 included those having a positive FOBT but refusing a colonoscopy. Control 2 included those who refused both an FOBT and colonoscopy. RESULTS:The impact of occupation on willingness to attend a colorectal screening program differed by gender. P for heterogeneity was 0.009 for case vs control group 1, 0.01 for case versus control group 2, and 0.80 for control group 1 vs 2. Poor awareness of CRC and its screening program, characteristics of screening tests, and lack of time affected the screening rate. Financial support, fear of pain and bowel preparation were barriers to a colonoscopy as a screening test. Eighty-two percent of control group 1 and 87.1% of control group 2 were willing attend if the colonoscopy was free, but only 56.3% and 53.1%,respectively, if it was self-paid. Multivariate odds ratios for case vs control group 1 were 0.10 among those unwilling to attend a free colonoscopy and 0.50 among those unwilling to attend a self-paid colonoscopy. CONCLUSION:Raising the public awareness of CRC and its screening, integrating CRC screening into the health care system, and using a painless colonoscopy would increase its screening rate.

  11. Efficacy and safety of CT-P13 (biosimilar infliximab) in patients with rheumatoid arthritis: comparison between switching from reference infliximab to CT-P13 and continuing CT-P13 in the PLANETRA extension study

    Science.gov (United States)

    Yoo, Dae Hyun; Prodanovic, Nenad; Jaworski, Janusz; Miranda, Pedro; Ramiterre, Edgar; Lanzon, Allan; Baranauskaite, Asta; Wiland, Piotr; Abud-Mendoza, Carlos; Oparanov, Boycho; Smiyan, Svitlana; Kim, HoUng; Lee, Sang Joon; Kim, SuYeon; Park, Won

    2017-01-01

    Objectives To assess the efficacy and safety of switching from the infliximab reference product (RP; Remicade) to its biosimilar CT-P13 (Remsima, Inflectra) or continuing CT-P13 in patients with rheumatoid arthritis (RA) for an additional six infusions. Methods This open-label extension study recruited patients with RA who had completed the 54-week, randomised, parallel-group study comparing CT-P13 with RP (PLANETRA; NCT01217086). CT-P13 (3 mg/kg) was administered intravenously every 8 weeks from weeks 62 to 102. All patients received concomitant methotrexate. Endpoints included American College of Rheumatology 20% (ACR20) response, ACR50, ACR70, immunogenicity and safety. Data were analysed for patients who received CT-P13 for 102 weeks (maintenance group) and for those who received RP for 54 weeks and then switched to CT-P13 (switch group). Results Overall, 302 of 455 patients who completed the PLANETRA study enrolled into the extension. Of these, 158 had received CT-P13 (maintenance group) and 144 RP (switch group). Response rates at week 102 for maintenance versus switch groups, respectively, were 71.7% vs 71.8% for ACR20, 48.0% vs 51.4% for ACR50 and 24.3% vs 26.1% for ACR70. The proportion of patients with antidrug antibodies was comparable between groups (week 102: 40.3% vs 44.8%, respectively). Treatment-emergent adverse events occurred in similar proportions of patients in the two groups during the extension study (53.5% and 53.8%, respectively). Conclusions Comparable efficacy and tolerability were observed in patients who switched from RP to its biosimilar CT-P13 for an additional year and in those who had long-term CT-P13 treatment for 2 years. Trial registration number NCT01571219; Results. PMID:27130908

  12. Study comparing the use of dynamic CT and Xe-CT CBF for ischemic cerebro-vascular disease

    Energy Technology Data Exchange (ETDEWEB)

    Terada, Tomoaki; Kikuchi, Haruhiko; Kuriyama, Yoshihiro; Nagata, Izumi; Yamagata, Sen; Naruo, Yoshito; Minamikawa, Jun; Kaneko, Takaji; Sakashita, Yoshiharu

    1987-06-01

    The simultaneous measurement of dynamic computerized tomography scanning (DCT) with an iodine-contrast enhancement material bolus injection and a simultaneous xenon CT-CBF-study was done on 15 patients (8 cases of unilateral internal carotid occlusion; 3, of unilateral middle cerebral arterial occlusion, and 4, without any major cerebral arterial occlusion or significant arterial stenosis) with ischemic cerebro-vascular diseases at the subacute and/or chronic stage. The value of the width and corrected first moment (cMT1) as well as their functional images, as acquired from DCT data, were compared to the 1-CBF value and the 1-CBF map of the xenon CT-CBF-study. A comparison of the functional images of DCT and 1-CBF showed that there was a good correlation between them in the cases without leptomeningeal anastomosis as a collateral circulation. However, a poor correlation between them was found in the cases with leptomeningeal anastomosis as a collateral circulation. The correlation of 1-CBF and 1/width with 1/cMT1 was significant (r = 0.78, p < 0.01) in the former cases, but it was not significant in the latter cases. The results of our data were thought to be due to the difference in the tracer inflow pattern between the cases without leptomeningeal anastomosis and those with it as a collateral circulation. The factor of cerebral blood volume should be considered in a more detailed study, although our cases did not include any patients with acute cerebral infarction or recanalized cases, which are thought to show various changes in the cerebral blood volume. The 1/width and 1/cMT1 values acquired from DCT well reflected the CBF in the cases without leptomeningeal anastomosis as a collateral circulation.

  13. Prognostic value of interim and restaging PET/CT in Hodgkin lymphoma. Results of the CHEAP (Chemotherapy Effectiveness Assessment by PET/CT) study - long term observation.

    Science.gov (United States)

    Miltenyi, Z; Barna, S; Garai, I; Simon, Z; Jona, A; Magyari, F; Gergely, M; Nagy, Z; Keresztes, K; Pettendi, P; Illes, A

    2015-01-01

    Very few studies have determined the prognostic value of interim and restaging PET/CT in patients with Hodgkin lymphoma using current standard of care therapy outside clinical trials. We analyzed the effect of the results of interim and restaging PET/CT on the survival (overall- and relapse-free) in patients who received standard first-line treatment based on the stage of disease and risk factors. We investigated the differences between the relapse and non-relapse groups based on the clinical pathological characteristics of patients who had positive interim PET/CT results.Between January 1, 2007 and December 31, 2011, the staging, interim and restaging PET/CT scans of patients with Hodgkin lymphoma were analyzed. The Deauville criteria were used for the evaluation of interim PET/CT scans. One hundred and thirteen Hodgkin lymphoma patients underwent staging, interim and restaging PET/CT scans. None of the therapy was modified based on the interim PET/CT results. The median follow-up time was 43.5 months. A total of 62 early stage patients and 51 advanced stage patients were identified. The five-year overall survival rates were 93.4% in the interim PET negative group and 58% in the interim PET positive group (pinterim PET positive group, patients over 40 years of age had a significantly higher probability of relapse (p=0.057).The routine clinical use of interim PET/CT is highly recommended based on our investigation. However, patients with positive interim PET/CT results required frequent additional evaluations.

  14. A simulation study on proton computed tomography (CT) stopping power accuracy using dual energy CT scans as benchmark

    DEFF Research Database (Denmark)

    Hansen, David Christoffer; Seco, Joao; Sørensen, Thomas Sangild

    2015-01-01

    Background. Accurate stopping power estimation is crucial for treatment planning in proton therapy, and the uncertainties in stopping power are currently the largest contributor to the employed dose margins. Dual energy x-ray computed tomography (CT) (clinically available) and proton CT (in...

  15. Timing-Invariant CT Angiography Derived from CT Perfusion Imaging in Acute Stroke : A Diagnostic Performance Study

    NARCIS (Netherlands)

    Smith, E. J.; Vonken, E. -J.; Meijer, F. J. A.; Dankbaar, J. W.; Horsch, A. D.; van Ginneken, B.; Velthuis, B.; van der Schaaf, I.; Prokop, M.

    2015-01-01

    BACKGROUND AND PURPOSE: Timing-invariant (or delay-insensitive) CT angiography derived from CT perfusion data may obviate a separate cranial CTA in acute stroke, thus enhancing patient safety by reducing total examination time, radiation dose, and volume of contrast material. We assessed the diagnos

  16. The effect of CT scanners in the trauma room - an observational study

    DEFF Research Database (Denmark)

    Wulffeld, Sandra; Rasmussen, L S; Bech, Birthe Højlund

    2017-01-01

    with a trauma resuscitation table. Subgroup analyses were performed on severely injured and patients with traumatic brain injury. RESULTS: We included 784 patients before and 742 patients after the reconstruction. Case-mix differed between study periods as there was a higher proportion of severe injuries....... METHODS: We included trauma patients admitted in two 1-year periods, before and after a major rebuilding of the trauma room. Beforehand, one CT scanner was located in an adjacent room. After the rebuilding, two mobile CT scanners were placed in the resuscitation bays, where a moving gantry was combined......, traumatic brain injury and penetrating trauma in the after period. We found a minor increase in time to CT in the after period (20 vs. 21 min, P = 0.008). In a multivariate regression analysis adjusted for differences in case-mix and with time to CT as outcome, period was an insignificant explanatory...

  17. A comparative study for spatial resolution and subjective image characteristics of a multi-slice CT and a cone-beam CT for dental use

    Energy Technology Data Exchange (ETDEWEB)

    Watanabe, Hiroshi, E-mail: hiro.orad@tmd.ac.jp [Oral and Maxillofacial Radiology, Division of Oral Restitution, Graduate School, Tokyo Medical and Dental University, 5-45 Yushima 1-chome, Bunkyo-ku, Tokyo 1138549 (Japan); Honda, Eiichi [Oral and Maxillofacial Radiology, Division of Oral Health Sciences, The University of Tokushima Graduate School (Japan); Tetsumura, Akemi; Kurabayashi, Tohru [Oral and Maxillofacial Radiology, Division of Oral Restitution, Graduate School, Tokyo Medical and Dental University, 5-45 Yushima 1-chome, Bunkyo-ku, Tokyo 1138549 (Japan)

    2011-03-15

    Purpose: Multi-slice CT (MSCT) and cone-beam CT (CBCT) are widely used in dental practice. This study compared the spatial resolution of these CT systems to elucidate which CT modalities should be selected for various clinical cases. Materials and methods: As MSCT and CBCT apparatuses, Somatom Sensation 64 and 3D Accuitomo instruments, respectively, were used. As an objective evaluation of spatial resolution of these CT systems, modulation transfer function (MTF) analysis was performed employing an over-sampling method. The results of MTF analysis were confirmed with a line-pair test using CATPHAN. As a subjective evaluation, a microstructure visualization ability study was performed using a Jcl:SD rat and a head CT phantom. Results: MTF analysis showed that for the in-plane direction, the z-axis ultrahigh resolution mode (zUHR) of the Sensation 64 and 3D Accuitomo instruments had higher spatial resolutions than the conventional mode (64x) of the Sensation 64, but for the longitudinal direction, the 3D Accuitomo had clearly higher spatial resolution than either mode of the Sensation 64. A line-pair test study and microstructure visualization ability studies confirmed the results for MTF analysis. However, images of the rat and the CT phantom revealed that the 3D Accuitomo demonstrated the failure to visualize the soft tissues along with aliasing and beam-hardening artifacts, which were not observed in the Sensation 64. Conclusions: This study successfully applied spatial resolution analysis using MSCT and CBCT systems in a comparative manner. These findings could help in deciding which CT modality should be selected for various clinical cases.

  18. Radiological findings of dissecting aneurysm -a correlative study of CT with angiography-

    Energy Technology Data Exchange (ETDEWEB)

    Bae, Tae Yeong; Park, Jae Hyung; Kim, Seung Hyup; Han, Man Chung [College of Medicine, Seoul National University, Seoul (Korea, Republic of)

    1987-06-15

    This study comprised 16 patients with aortic dissecting aneurysm who were admitted to Seoul National University Hospital from May 1984 to January 1987. CT findings in 16 cases of aortic dissecting aneurysm were correlated with angiographic findings retrospectively. The results were analysed. 1. Number of male was 11 and that of female was 5. Male patients in fifties were most common and 4 in number. 13 patients had hypertension or history of hypertension among 14 patients. There were one case of Marfan's syndrome, preeclampsia and Takayasu's arteritis respectively. 2. There were 5 cases of DeBakey type I, 1 case of type II and 9 cases of types III dissecting aneurysm. Type III was most common. 3. CT confirmed as superior vena cava which was not identified whether it was superior vena cava or unopacified false lumen by angiography in one case. Regarding distal extent, authors defined A whose extent was proximal to diaphragm and B beyond it for convenience sake. There was one false negative case in CT among 16 cases which was diagnosed as dissecting aneurysm type IIIB by angiography and confirmed as type III surgically. One case was diagnosed as type IB by CT and as type IIIB by angiography and confirmed as type I surgically. Extent was more accurate in CT than angiography. One case was diagnosed as type II by CT but misdiagnosed as right atrial tumor by angiography. 4. Diagnostic sensitivities of CT and angiography in this study were 94% (15/16) respectively. CT was more advantageous in hemothorax, hemopericardium, hemomediastinum, unopacified false lumen, aortic wall calcification and getting information about mediastinum. In angiography aortic regurgitation and tear site and involvement of abdominal vessels could be observed.

  19. Detection of Dental Pathologies in Routine Paranasal CT Scans: A Retrospective Study.

    Science.gov (United States)

    Bulbul, Erdogan; Yanik, Bahar; Demirpolat, Gulen

    2017-07-01

    Multidetector Computed Tomography (MDCT) is a widespread method for evaluating paranasal sinuses and nasal cavity in daily practice. The maxillary teeth are in field of view in a paranasal sinus CT scan and it is possible to detect dental pathologies with CT. To determine the incidence of maxillary teeth pathologies in routine paranasal sinus CT scans. A retrospective study was conducted. Consecutive 395 paranasal sinus CT scans were evaluated. All CT images were obtained with a 64 detector-CT. Patients with previous facial trauma, operation, invasive tumors and repeated exams were excluded. Detected findings were classified as "tooth loss, dental restorations or procedures and dental pathologies (carious lesions, dental developmental anomalies, periapical lesions and periodontal diseases). The proportion of findings was reported as simple percentiles. Three hundred and eighty-four CT scans were included in the study. Dental restorations or procedures were determined in 129 (33.5%) patients. A total of 34 (8.8%) patients had normal teeth count and morphology. A total of 264 (64.3%) patients had at least one tooth loss. A total of 195 (51%) patients had at least one or more dental pathology. Number of dental carious lesions, dental developmental anomalies, periapical lesions and periodontal disease were 104 (27.0%), 78 (14.3%), 46 (11.9%), 44 (11.4%), respectively. Dental pathologies were encountered in more than half of the patients. Detecting dental pathologies may prevent tooth loss and improve oral health. The radiologist should keep in mind dental pathologies while evaluating paranasal sinus CT in daily practice.

  20. An experimental study for qualitatively diagnosing stapes lesions by helical 3-dimensional CT

    Energy Technology Data Exchange (ETDEWEB)

    Kawaue, Akifumi; Kuki, Kiyonori; Yamanaka, Noboru [Wakayama Medical Univ., Wakayama (Japan); Nishimura, Michihiko

    2001-08-01

    To evaluate qualitative diagnosis of stapes lesions by 3-dimensional computed tomography (3D-CT) combined with superselective image processing (3D-SS) of stapes, we studied helical 3D-CT on a phantom model of the temporal bone. Two stapes models were used-1 made from the bone filler, Celatite, consistent in bone density but changing in cross sectional area, and the other made from an apacerum rod used in quantitative computed tomography (QCT), consistent in cross sectional area but changing in bone density. These stapes models were put into a skull phantom and analyzed by helical 3D-CT. The influence of the tympanic cavity conditions on CT images of stapes was evaluated by filling the phantom model with Vaseline following 3D selective reconstruction. In all stapes models, lowering the lower CT window width threshold resulted in an enlarged cross-sectional area of the model. The higher the bone density, the lower the increase in cross-sectional area in the image. The stapes model with lower density had greater influence on the imaging by tympanic cavity conditions and was likely to be misdiagnosed as showing higher bone density. Based on the experimental study, 3D-SS by helical 3D-CT appears to be a useful measure for qualitatively diagnosing stapes lesions. (author)

  1. Segmentation of Lung Structures in CT

    DEFF Research Database (Denmark)

    Lo, Pechin Chien Pau

    This thesis proposes and evaluates new algorithms for segmenting various lung structures in computed tomography (CT) images, namely the lungs, airway trees and vessel trees. The main objective of these algorithms is to facilitate a better platform for studying Chronic Obstructive Pulmonary Disease...... (COPD) using CT scans from the Danish Lung Cancer Screening Trial (DLCST) study. We propose a fully automated lung segmentation algorithm that is based on region growing and the assumption that the lungs are of lower intensities than surrounding structures in CT. Furthermore, we also propose a post...... processing step that detects and removes esophagus regions, wrongly added by the region growing process, to improve the reliability of the lung segmentation algorithm. The proposed algorithm has been successfully applied to more than 6000 low dose CT scans from the DLCST study. Among the CT scans applied...

  2. Segmentation of Lung Structures in CT

    DEFF Research Database (Denmark)

    Lo, Pechin Chien Pau

    This thesis proposes and evaluates new algorithms for segmenting various lung structures in computed tomography (CT) images, namely the lungs, airway trees and vessel trees. The main objective of these algorithms is to facilitate a better platform for studying Chronic Obstructive Pulmonary Disease...... (COPD) using CT scans from the Danish Lung Cancer Screening Trial (DLCST) study. We propose a fully automated lung segmentation algorithm that is based on region growing and the assumption that the lungs are of lower intensities than surrounding structures in CT. Furthermore, we also propose a post...... processing step that detects and removes esophagus regions, wrongly added by the region growing process, to improve the reliability of the lung segmentation algorithm. The proposed algorithm has been successfully applied to more than 6000 low dose CT scans from the DLCST study. Among the CT scans applied...

  3. MULTIDETECTOR CT STUDY OF ANATOMICAL VARIANTS OF ETHMOID SINUS

    Institute of Scientific and Technical Information of China (English)

    李玉华; 薛建平; 朱铭

    2004-01-01

    Objective To evaluate the significance of multidetector CT 3D reconstruction technique in showing anatomy of ethmoid sinus, at the same time, anatomic variations of ethmoid sinus and its clinical significance were also discussed. Methods 250 cases of ethmoid sinuses were scanned transversally by multidetector scaner, coronal and sagittal views were reconstructed. Results Coronal and sagittal views were good enough to make diagnosis. 5 kinds of common ethmoid sinus variations were seen, including pneumatization of ethmoid bulla (56. 5% ) , Onodi air cell(26% ) , Hailer cell(6. 5% ) ,low ethmoid foveolas( 4. 3% )and over intromigratiny lamella papyracea (6. 5% ). Conclusion The coronal and other special views of ethmoid sinus are showed clearly by 3 D reconstruction which can provide detailed image informations for functional endoscopic sinus surgery.

  4. Colon distension, perceived burden and side-effects of CT-colonography for screening using hyoscine butylbromide or glucagon hydrochloride as bowel relaxant

    Energy Technology Data Exchange (ETDEWEB)

    Haan, Margriet C. de, E-mail: margrietcdehaan@gmail.com [Department of Radiology, Academic Medical Centre, Meibergdreef 9, 1105 AZ Amsterdam (Netherlands); Boellaard, Thierry N., E-mail: t.n.boellaard@amc.uva.nl [Department of Radiology, Academic Medical Centre, Meibergdreef 9, 1105 AZ Amsterdam (Netherlands); Bossuyt, Patrick M., E-mail: p.m.bossuyt@amc.uva.nl [Department of Clinical Epidemiology, Biostatistics and Bioinformatics, Academic Medical Centre, Meibergdreef 9, 1105 AZ Amsterdam (Netherlands); Stoker, Jaap, E-mail: j.stoker@amc.uva.nl [Department of Radiology, Academic Medical Centre, Meibergdreef 9, 1105 AZ Amsterdam (Netherlands)

    2012-08-15

    Objective: Compare colonic distension and perceived burden of CT-colonography between participants receiving hyoscine butylbromide (buscopan) and glucagon hydrochloride as bowel relaxant. Materials and methods: Data were collected within a screening trial. Participants received 20 mg buscopan intravenously or 1 mg of glucagon intravenously (if buscopan contra-indicated). Colon distension per segment was assessed using a 4-point scale (prone and supine). Data on perceived burden of CT-colonography were collected using a questionnaire two weeks after the examination. Outcome measures between groups were compared using propensity score matching. We used a stratified Wilcoxon-Mann-Whitney test statistic for quantitative and Cochran-Mantel-Haenszel statistics for categorical variables. Results: 541 participants were included: 336 (62%) received buscopan and 205 received glucagon. All buscopan recipients had an adequately distended colon, compared to 96% in the glucagon group (RR 7.31, 95% CI: 1.61-33.28). More glucagon recipients scored the insufflation as rather or extremely burdensome (25% vs. 16%; overall mean score 2.7 vs. 2.4; p < 0.001) and more found the entire CT-colonography rather or extremely burdensome (14% vs. 7%; 2.2 vs. 1.9; p = 0.001). Most frequently reported side effects were a dry mouth in the buscopan group (15%) and nausea in the glucagon group (13%). Conclusion: Compared to glucagon, premedication with buscopan results in significantly more adequately distended colons and a less burdensome procedure. When buscopan can be used, it is the preferred bowel relaxant.

  5. Screening and cervical cancer cure: population based cohort study

    OpenAIRE

    Andrae, B.; Andersson, T. M.-L.; Lambert, P C; Kemetli, L.; Silfverdal, L.; Strander, B.; Ryd, W.; Dillner, J.; Tornberg, S.; Sparen, P.

    2012-01-01

    Objective To determine whether detection of invasive cervical cancer by screening results in better prognosis or merely increases the lead time until death. Design Nationwide population based cohort study. Setting Sweden. Participants All 1230 women with cervical cancer diagnosed during 1999-2001 in Sweden prospectively followed up for an average of 8.5 years. Main outcome measures Cure proportions and five year relative survival ratios, stratified by screening history, mode of detection, age...

  6. Lung cancer screening with CT: Evaluation of radiologists and different computer assisted detection software (CAD) as first and second readers for lung nodule detection at different dose levels

    Energy Technology Data Exchange (ETDEWEB)

    Christe, A., E-mail: andreas.christe@insel.ch [Department of Diagnostic, Interventional und Pediatric Radiology, University Hospital, Inselspital, Bern (Switzerland); Leidolt, L.; Huber, A.; Steiger, P. [Department of Diagnostic, Interventional und Pediatric Radiology, University Hospital, Inselspital, Bern (Switzerland); Szucs-Farkas, Z. [Radiology, Hospital Center of Biel (Switzerland); Roos, J.E. [Department of Radiology, Duke University, Durham, NC (United States); Heverhagen, J.T.; Ebner, L. [Department of Diagnostic, Interventional und Pediatric Radiology, University Hospital, Inselspital, Bern (Switzerland)

    2013-12-01

    Objectives: To find the best pairing of first and second reader at highest sensitivity for detecting lung nodules with CT at various dose levels. Materials and methods: An anthropomorphic lung phantom and artificial lung nodules were used to simulate screening CT-examination at standard dose (100 mAs, 120 kVp) and 8 different low dose levels, using 120, 100 and 80 kVp combined with 100, 50 and 25 mAs. At each dose level 40 phantoms were randomly filled with 75 solid and 25 ground glass nodules (5–12 mm). Two radiologists and 3 different computer aided detection softwares (CAD) were paired to find the highest sensitivity. Results: Sensitivities at standard dose were 92%, 90%, 84%, 79% and 73% for reader 1, 2, CAD1, CAD2, CAD3, respectively. Combined sensitivity for human readers 1 and 2 improved to 97%, (p1 = 0.063, p2 = 0.016). Highest sensitivities – between 97% and 99.0% – were achieved by combining any radiologist with any CAD at any dose level. Combining any two CADs, sensitivities between 85% and 88% were significantly lower than for radiologists combined with CAD (p < 0.03). Conclusions: Combination of a human observer with any of the tested CAD systems provide optimal sensitivity for lung nodule detection even at reduced dose at 25 mAs/80 kVp.

  7. CTDI versus new AAPM metrics to assess doses in CT: a case study

    Energy Technology Data Exchange (ETDEWEB)

    Campelo, M.C.S., E-mail: maria.macalidi@gmail.com [Pontificia Universidade Catolica de Sao Paulo (PUC-SP), SP (Brazil); Silva, M.C., E-mail: marciac.silvag@gmail.com [Hospital Israelita Albert Einstein (HIAE), Sao Paulo, SP (Brazil); Terini, R.A., E-mail: ricardoaterini@gmail.com [Universidade de Sao Paulo (LABEND/USP), SP (Brazil). Laboratorio de Ensaios Nao-Destrutivos

    2016-07-01

    In modern CT, CTDI100 measurements would underestimate accumulated dose at the gantry center. AAPM TG 111 report proposed improved metrics for CT dosimetry, mainly for helical and wide beam width scanning. In this study, a methodology to assess CT dose, inspired on TG 111, was applied. Dosimeters were firstly calibrated in lab in beams like those utilized clinically. Using a reference 0.6cc Farmer chamber, two CT “pencil” chambers were calibrated in P{sub KL} by substitution method. Results showed differences ≤ 2% in the calibration coefficients, for three collimation apertures. A small 0.6cc chamber was calibrated in air kerma with this setup, without any collimator. After this, in a private Brazilian hospital, the small chamber was applied in dosimetry tests of a CT scanner, according to TG 111, determining Dose profiles and Equilibrium dose free-in-air (D{sub eq,air}) for some protocols and pitch values. Results showed that D{sub eq,air} increased when reducing pitch and Equilibrium dose-pitch product free in air (p.D{sub eq,air}) remain constant. In measurements with a 450mm CT phantom, differences between Planar Average Equilibrium Dose (D{sub eq,p}) and CTDIvol ranged between 30-37%. This occurs because CTDI{sub vol} cannot include dose profile 'tail' contribution, caused by scattering in phantom, especially for wide beam widths. (author)

  8. An experimental comparative study of radiography, ultrasonography and CT imaging in the IV catheter fragment

    Energy Technology Data Exchange (ETDEWEB)

    Kweon, Dae Cheol [Dept. of Radiological Science, College of Health Science, Shinhan University, Uijeongbu (Korea, Republic of)

    2016-06-15

    The objective of this study was to detect the fragments generated during IV (intravenous) catheter injection of contrast medium and drug administration in a clinical setting and removal was performed by experimentally producing a phantom, and to compare the radiography, ultrasonography, and multi-detector computed tomography (MDCT) imaging and radiation dose. A 1 cm fragment of an 18 gage Teflon® IV catheter with saline was inserted into the IV control line. Radiography, CT, and ultrasonography were performed and radiography and CT dose were calculated. CT and ultrasonography showed an IV catheter fragment clinically and radiography showed no visible difference in the ability to provide a useful image of an IV catheter fragment modality (p >.05). Radiography of effective dose (0.2139 mSv·Gy-1·cm-2) form DAP DAP (0.93 μGy·m2 ), and dose length product (DLP) (201 mGy·cm) to effective dose was calculated as 0.483 mSv. IV catheter fragment were detected of radiography, ultrasonography and CT. These results can be obtained by menas of an excellent IV catheter fragment of detection capability CT. However, CT is followed by radiation exposure. IV catheter fragment confirming the position and information recommend an ultrasonography.

  9. Impact of low-dose CT scan in dual timepoint investigations: a phantom study

    DEFF Research Database (Denmark)

    Micheelsen, M A; Jensen, Mikael

    2011-01-01

    with a CT image and also use the CT for attenuation correction. In any practical hospital setting, 1 hour is too long to occupy the scanner bed and a second CT procedure thus becomes necessary. This study tries to validate to what extent the dose/quality of the second CT scan can be lowered, without...... compromising attenuation correction, lesion detection and quantification. Using a standard NEMA phantom with the GE Discovery PET/CT scanner, taken in and out between scan sessions, we have tried to find the minimal CT dose necessary for the second scan while still reaching tissue activity quantification...... within predetermined error limits. For a hot sphere to background activity concentration ratio of 1:5, the average uptake (normalised by the time corrected input activity concentration) in a sphere of 6 cm3 was found to be 0.90 ± 0.08 for the standard scan, yielding a dose of 5.5 mGy, and 0.90 ± 0...

  10. Screening for coronary artery disease in respiratory patients: comparison of single- and dual-source CT in patients with a heart rate above 70 bpm.

    Science.gov (United States)

    Pansini, Vittorio; Remy-Jardin, Martine; Tacelli, Nunzia; Faivre, Jean-Baptiste; Flohr, Thomas; Deken, Valérie; Duhamel, Alain; Remy, Jacques

    2008-10-01

    To evaluate the assessibility of coronary arteries in respiratory patients with high heart rates. This study was based on the comparative analysis of two paired populations of 54 patients with a heart rate >70 bpm evaluated with dual-source (group 1) and single-source (group 2) CT. The mean heart rate was 89.1 bpm in group 1 and 86.7 bpm in group 2 (P=0.26). The mean number of assessable segments per patient was significantly higher in group 1 compared to group 2 (P bpm, 35.6% for heart rates bpm, 40% for heart rates bpm, and 60% for heart rates bpm in group 1 and 11.3, 12.2, 8.8, and 10% for the corresponding thresholds in group 2 (P<0.05). In both groups of patients, coronary artery imaging was obtained from standard CT angiograms of the chest. The improvement in coronary imaging with dual-source CT suggests that high heart rates should no longer be considered as contraindications for ECG-gated CT angiograms of the chest whenever clinically relevant.

  11. Detectability index of differential phase contrast CT compared with conventional CT: a preliminary channelized Hotelling observer study

    Science.gov (United States)

    Tang, Xiangyang; Yang, Yi; Tang, Shaojie

    2013-03-01

    Under the framework of model observer with signal and background exactly known (SKE/BKE), we investigate the detectability of differential phase contrast CT compared with that of the conventional attenuation-based CT. Using the channelized Hotelling observer and the radially symmetric difference-of-Gaussians channel template , we investigate the detectability index and its variation over the dimension of object and detector cells. The preliminary data show that the differential phase contrast CT outperforms the conventional attenuation-based CT significantly in the detectability index while both the object to be detected and the cell of detector used for data acquisition are relatively small. However, the differential phase contrast CT's dominance in the detectability index diminishes with increasing dimension of either object or detector cell, and virtually disappears while the dimension of object or detector cell approaches a threshold, respectively. It is hoped that the preliminary data reported in this paper may provide insightful understanding of the differential phase contrast CT's characteristic in the detectability index and its comparison with that of the conventional attenuation-based CT.

  12. Deepgoing study on intrathoracic tuberculous lymphadenitis in adults using multidetector CT

    Institute of Scientific and Technical Information of China (English)

    LUO Ming-yue; LIU Li; LAI Li-sha; DONG Yun-xu; LIANG Wen-wei; QIN Jie

    2010-01-01

    Background Studies on intrathoracic tuberculous lymphadenitis in adults are confined to the preliminary CT findings with ordinary CT and ordinary spiral CT.There has been no deepgoing study of multidetector CT to date.Multidetector CT could contribute to better imaging of intrathoracic tuberculous lymphadenitis in adults.The purpose of this study was to explore the multidetector CT features of intrathoracic tuberculous lymphadenitis in adults, and the correlation with clinical symptoms and pathologic changes.Methods Multidetector CT findings from 42 consecutive adult patients with intrathoracic tuberculous lymphadenitis were analyzed retrospectively with regard to locations, sizes, numbers, shapes, margins, and densities reviewing precontrast and enhanced images.CT results were correlated with clinical symptoms and pathologic results (n=37).Results One hundred and eighty-five intrathoracic lymph nodes that had tuberculous lymphadenitis in 42 patients were distributed mainly in regions 4R (n=37), 2R (n=33), 7 (n=31) and 10R (n=21), more than 2 regions were implicated in 34 patients.One hundred and twenty-two (72.2%) of the tuberculous lymphadenitis without confluence were oval or round with clear margins.On precontrast scanning, 78.4% of tuberculous lymphadenitis had a homogeneous density.Seven enhancement patterns were demonstrated in 169 tuberculous lymphadenitis from 37 patients with pathologic results:homogeneous enhancement with no clinical symptom (n=12), corresponded pathologically to tuberculous hyperplasia without caseous necrosis; heterogeneous enhancement with a small central no enhancement area, slight clinical symptoms (n=22), tuberculous granulomas with a little caseous necroses; peripheral irregular thick wall enhancement with a central area with no enhancement, slight clinical symptoms (n=52), tuberculous granulomas with some caseous necroses in the center; peripheral thin rim enhancement with a central area having no enhancement, moderate clinical

  13. Prognostic indices for cerebral venous thrombosis on CT perfusion: A prospective study

    Energy Technology Data Exchange (ETDEWEB)

    Gupta, Rakesh Kumar, E-mail: rakrakgupta@gmail.com [Department of Radiodiagnosis and Imaging, MMIMSR, Mullana, Ambala (India); Bapuraj, J.R., E-mail: jrajiv@med.umich.edu [Department of Radiology, Division of Neuroradiology, University Hospital, University of Michigan, 1500 E Medical Center Drive, Ann Arbor, MI 48109 (United States); Khandelwal, N. [Department of Radiodiagnosis and Imaging, Postgraduate Institute of Medical Education and Research (PGIMER), Chandigarh (India); Khurana, Dheeraj [Department of Neurology, Postgraduate Institute of Medical Education and Research (PGIMER), Chandigarh (India)

    2014-01-15

    Purpose: We determined the prognostic significance of CT perfusion characteristics of patients with cerebral venous sinus thrombosis (CVST) and assessed the change in perfusion parameters following anticoagulation therapy. Materials and methods: 20 patients with CVST diagnosed on non-contrast computed tomography (NCCT), magnetic resonance imaging (MRI), and magnetic resonance venography (MRV) were included in this study. The initial CT perfusion study was performed at the time of admission. The following perfusion parameters: relative cerebral blood flow (rCBF), relative cerebral blood volume (rCBV), and relative mean transit time (rMTT) were calculated in the core and periphery of the affected area of the brain. Follow-up CT perfusion studies were performed at 1 month following anticoagulation therapy and the perfusion parameters thus obtained were compared with pre-treatment results. Receiver operating characteristic (ROC) curve analysis was performed to determine the prognostic significance of perfusion parameters. Results: All patients in this study showed areas of hypoperfusion on CT perfusion. To determine the favorable clinical outcome on basis of perfusion parameters, ROC curve analysis was performed which showed that the optimal threshold for rCBF > 60.5%, rCBV > 75.5%, and rMTT < 148.5% correlated with better clinical outcomes. Post treatment perfusion parameters showed significant correlation in core of the lesion (p < 0.05) than in the periphery. Conclusion: CT perfusion studies in CVST are a good prognostic tool and yield valuable information regarding clinical outcome.

  14. [Study of patients with prolonged fever with (18)F-FDG PET/CT].

    Science.gov (United States)

    Moragas, M; Cozar, M Puig; Buxeda, M; Soler, M; Riera, E; García, J R

    2015-01-01

    To review the findings on (18)F-FDG PET-CT in patients with fever of unknown origin lasting more than 7 days. This retrospective descriptive observational study included 93 (18)F-FDG PET-CT studies to detect a fever-causing focus done at three nuclear medicine centers from October 2006 through February 2014. A nuclear medicine specialist and a radiologist reviewed the images for foci of pathological uptake; another specialist's opinion resolved discrepancies. The findings on (18)F-FDG PET-CT studies were checked against clinical and/or histological findings. Abnormal (18)F-FDG uptake on PET-CT that could explain the cause of the fever was found in 52 (56%) of the 93 studies, and the cause of the fever was confirmed in 50 of these 52 studies. In the 50 cases in which the cause of the fever was confirmed, infection was the most common cause (54%), followed by noninfectious inflammatory disease (28%) and tumors (18%). (18)F-FDG PET-CT is useful in diagnosing the cause of prolonged febrile illness, so it might be practical to use it earlier in the diagnostic process. Copyright © 2014 SERAM. Published by Elsevier España, S.L.U. All rights reserved.

  15. Measuring femoral lesions despite CT metal artefacts: a cadaveric study

    Energy Technology Data Exchange (ETDEWEB)

    Malan, Daniel F. [Leiden University Medical Center, Department of Orthopaedics, Leiden (Netherlands); Delft University of Technology, Department of Mediamatics, EEMCS, P.O. Box 5031, Delft (Netherlands); Botha, Charl P. [Delft University of Technology, Department of Mediamatics, EEMCS, P.O. Box 5031, Delft (Netherlands); Leiden University Medical Center, Department of Radiology, Leiden (Netherlands); Kraaij, Gert; Heide, Huub J.L. van der; Nelissen, Rob G.H.H. [Leiden University Medical Center, Department of Orthopaedics, Leiden (Netherlands); Joemai, Raoul M.S. [Leiden University Medical Center, Department of Radiology, Leiden (Netherlands); Valstar, Edward R. [Leiden University Medical Center, Department of Orthopaedics, Leiden (Netherlands); Delft University of Technology, Department of Biomechanical Engineering, Delft (Netherlands)

    2012-05-15

    Computed tomography is the modality of choice for measuring osteolysis but suffers from metal-induced artefacts obscuring periprosthetic tissues. Previous papers on metal artefact reduction (MAR) show qualitative improvements, but their algorithms have not found acceptance for clinical applications. We investigated to what extent metal artefacts interfere with the segmentation of lesions adjacent to a metal femoral implant and whether metal artefact reduction improves the manual segmentation of such lesions. We manually created 27 periprosthetic lesions in 10 human cadaver femora. We filled the lesions with a fibrotic interface tissue substitute. Each femur was fitted with a polished tapered cobalt-chrome prosthesis and imaged twice - once with the metal, and once with a substitute resin prosthesis inserted. Metal-affected CTs were processed using standard back-projection as well as projection interpolation (PI) MAR. Two experienced users segmented all lesions and compared segmentation accuracy. We achieved accurate delineation of periprosthetic lesions in the metal-free images. The presence of a metal implant led us to underestimate lesion volume and introduced geometrical errors in segmentation boundaries. Although PI MAR reduced streak artefacts, it led to greater underestimation of lesion volume and greater geometrical errors than without its application. CT metal artefacts impair image segmentation. PI MAR can improve subjective image appearance but causes loss of detail and lower image contrast adjacent to prostheses. Our experiments showed that PI MAR is counterproductive for manual segmentation of periprosthetic lesions and should be used with care. (orig.)

  16. Diabetic Retinopathy Screening Using Telemedicine Tools: Pilot Study in Hungary

    Science.gov (United States)

    Eszes, Dóra J.; Szabó, Dóra J.; Russell, Greg; Kirby, Phil; Paulik, Edit; Nagymajtényi, László

    2016-01-01

    Introduction. Diabetic retinopathy (DR) is a sight-threatening complication of diabetes. Telemedicine tools can prevent blindness. We aimed to investigate the patients' satisfaction when using such tools (fundus camera examination) and the effect of demographic and socioeconomic factors on participation in screening. Methods. Pilot study involving fundus camera screening and self-administered questionnaire on participants' experience during fundus examination (comfort, reliability, and future interest in participation), as well as demographic and socioeconomic factors was performed on 89 patients with known diabetes in Csongrád County, a southeastern region of Hungary. Results. Thirty percent of the patients had never participated in any ophthalmological screening, while 25.7% had DR of some grade based upon a standard fundus camera examination and UK-based DR grading protocol (Spectra™ software). Large majority of the patients were satisfied with the screening and found it reliable and acceptable to undertake examination under pupil dilation; 67.3% were willing to undergo nonmydriatic fundus camera examination again. There was a statistically significant relationship between economic activity, education and marital status, and future interest in participation. Discussion. Participants found digital retinal screening to be reliable and satisfactory. Telemedicine can be a strong tool, supporting eye care professionals and allowing for faster and more comfortable DR screening. PMID:28078306

  17. Diabetic Retinopathy Screening Using Telemedicine Tools: Pilot Study in Hungary

    Directory of Open Access Journals (Sweden)

    Dóra J. Eszes

    2016-01-01

    Full Text Available Introduction. Diabetic retinopathy (DR is a sight-threatening complication of diabetes. Telemedicine tools can prevent blindness. We aimed to investigate the patients’ satisfaction when using such tools (fundus camera examination and the effect of demographic and socioeconomic factors on participation in screening. Methods. Pilot study involving fundus camera screening and self-administered questionnaire on participants’ experience during fundus examination (comfort, reliability, and future interest in participation, as well as demographic and socioeconomic factors was performed on 89 patients with known diabetes in Csongrád County, a southeastern region of Hungary. Results. Thirty percent of the patients had never participated in any ophthalmological screening, while 25.7% had DR of some grade based upon a standard fundus camera examination and UK-based DR grading protocol (Spectra™ software. Large majority of the patients were satisfied with the screening and found it reliable and acceptable to undertake examination under pupil dilation; 67.3% were willing to undergo nonmydriatic fundus camera examination again. There was a statistically significant relationship between economic activity, education and marital status, and future interest in participation. Discussion. Participants found digital retinal screening to be reliable and satisfactory. Telemedicine can be a strong tool, supporting eye care professionals and allowing for faster and more comfortable DR screening.

  18. Predicting arterial injuries after penetrating brain trauma based on scoring signs from emergency CT studies.

    Science.gov (United States)

    Bodanapally, Uttam K; Krejza, Jaroslaw; Saksobhavivat, Nitima; Jaffray, Paul M; Sliker, Clint W; Miller, Lisa A; Shanmuganathan, Kathirkamanathan; Dreizin, David

    2014-04-01

    The objective of this study was to determine the accuracy of individual radiologists in detection of vascular injury in patients after penetrating brain injury (PBI) based on head CT findings at admission. We retrospectively evaluated 54 PBI patients who underwent admission head CT and digital subtraction angiography (DSA), used here as a reference standard. Two readers reviewed the CT images to determine the presence or absence of the 29 CT variables of injury profile and quantified selected variables. Four experienced trauma radiologists and one neuroradiologist assigned their own specific scores for each CT variable, a high score indicative of a high probability of artery injury. A sixth set consisted of the average score obtained from the five sets, generated by five experts. Receiver operating characteristic (ROC) curves were constructed for each set to assess the diagnostic performance of an individual radiologist in predicting an underlying vascular injury. The area under ROC curve (AUC) was higher for CT scores obtained from the sixth set (average of five sets of scores) of variable rank score 0.75 (95% CI 0.62-0.88) and for the rest of the data sets, the value ranged from 0.70 (95% CI 0.56-0.84) to 0.74 (95% CI 0.6-0.88). In conclusion, radiologists may be able to recommend DSA with a fair accuracy rate in selected patients, deemed 'high-risk' for developing intracranial vascular injuries after PBI based on admission CT studies. A better approach needs to be developed to reduce the false positive rate to avoid unnecessary emergency DSA.

  19. IronMaking Process Alternatives Screening Study

    Energy Technology Data Exchange (ETDEWEB)

    none,

    2000-10-01

    This study by Lockwood Greene evaluates a number ironmaking processes. The appendices provide greater detail and further exploration of the ironmaking processes, including components, relative costs, and comparisons.

  20. High pitch CT in triple rule-out studies: Radiation dose and image quality compared to multidetector CT.

    Science.gov (United States)

    Fernández del Valle, A; Delgado Sánchez-Gracián, C; Oca Pernas, R; Grande Astorquiza, A; Bustos Fiore, A; Trinidad López, C; Tardáguila de la Fuente, G

    2015-01-01

    To compare the image quality and radiation dose from high pitch dual source CT (128-DSCT) versus those from retrospective acquisition with 64-row multidetector CT (64-MDCT) in triple rule-out studies. We retrospectively studied 60 patients with acute chest pain: 30 with a retrospective EKG acquisition with 64-MDCT and 30 with high pitch 128-DSCT. We quantitatively analyzed the image quality by calculating the vascular density, muscular density (DM), noise, vascular density/noise ratio (VDNR), and contrast/noise ratio (CNR). We qualitatively evaluated the artifacts in the vena cava, aorta, and coronary arteries. We estimated the effective dose (ED) of radiation by means of the dose-length product. There were no significant differences between 128-DSCT and 64-MDCT in the vascular density. The VDNR and CNR were higher on 128-DSCT than on 64-MDCT in the aorta (VDNR: 28.9 ± 11.7 vs. 20 ± 5.5; CNR: 24.4 ± 10.9 vs. 16.8 ± 5.4; P<.01), in the pulmonary arteries (VDNR: 25.5 ± 10 vs. 20.6 ± 6.5; CNR: 24.5 ± 5.4 vs. 17.4 ± 6.4; P<.01), and in the coronary arteries (VDNR: 25.9 ± 8.2 vs. 18.9 ± 4.9; CNR: 24.9 ± 8.2 vs. 15.6 ± 4.6; P<.01). There were fewer artifacts in the coronary arteries on 128-DSCT than on 64-MDCT (3 vs. 34 nondiagnostic segments; P<.001), and the ED in 128-DSCT was lower than in 64-MDCT (13.77 ± 4 vs. 2.77 ± 0.6 mSv; P<.001). In triple rule-out studies, high pitch 128-DSCT delivers a lower dose of radiation and provides better image quality than retrospective acquisition with 64-MDCT. Copyright © 2014 SERAM. Published by Elsevier España, S.L.U. All rights reserved.

  1. Problems and Limitations in Studies on Screening for Language Delay

    Science.gov (United States)

    Eriksson, Marten; Westerlund, Monica; Miniscalco, Carmela

    2010-01-01

    This study discusses six common methodological limitations in screening for language delay (LD) as illustrated in 11 recent studies. The limitations are (1) whether the studies define a target population, (2) whether the recruitment procedure is unbiased, (3) attrition, (4) verification bias, (5) small sample size and (6) inconsistencies in choice…

  2. Smoking cessation and lung cancer screening

    DEFF Research Database (Denmark)

    Pedersen, Jesper Holst; Tønnesen, Philip; Ashraf, Haseem

    2016-01-01

    Smoking behavior may have a substantial influence on the overall effect of lung cancer screening. Non-randomized studies of smoking behavior during screening have indicated that computer tomography (CT) screening induces smoking cessation. Randomized studies have further elaborated that this effect...... and decrease smoking relapse rate. Also low smoking dependency and high motivation to quit smoking at baseline predicted smoking abstinence in screening trials. Lung cancer screening therefore seems to be a teachable moment for smoking cessation. Targeted smoking cessation counselling should be an integrated...... part of future lung cancer screening trials....

  3. CT colonography: an update

    Energy Technology Data Exchange (ETDEWEB)

    Aschoff, Andrik J.; Ernst, Andrea S.; Brambs, Hans-Juergen; Juchems, Markus S. [University Hospitals of Ulm, Diagnostic and Interventional Radiology, Ulm (Germany)

    2008-03-15

    Computed tomographic (CT) colonography (CTC) - also known as ''virtual colonoscopy'' - was first described more than a decade ago. As advancements in scanner technology and three-dimensional (3D) postprocessing helped develop this method to mature into a potential option in screening for colorectal cancer, the fundamentals of the examination remained the same. It is a minimally invasive, CT-based procedure that simulates conventional colonoscopy using 2D and 3D computerized reconstructions. The primary aim of CTC is the detection of colorectal polyps and carcinomas. However, studies reveal a wide performance variety in regard to polyp detection, especially for smaller polyps. This article reviews the available literature, discusses established indications as well as open issues and highlights potential future developments of CTC. (orig.)

  4. Comparison of image quality in head CT studies with different dose-reduction strategies

    DEFF Research Database (Denmark)

    Johansen, Jeppe; Nielsen, Rikke; Fink-Jensen, Vibeke;

    The number of multi-detector CT examinations is increasing rapidly. They allow high quality reformatted images providing accurate and precise diagnosis at maximum speed. Brain examinations are the most commonly requested studies, and although they come at a lower effective dose than body CT, can...... account to a considerable radiation dose as many patients undergo repeated studies. Therefore, various dose-reduction strategies are applied such as automated tube current and voltage modulation and recently different iterative reconstruction algorithms. However, the trade-off of all dose......-reduction maneuvers is reduction of image quality due to image noise or artifacts. The aim of our study was therefore to find the best diagnostic images with lowest possible dose. We present results of dose- and image quality optimizing strategies of brain CT examinations at our institution. We compare sequential...

  5. SU-E-J-72: Dosimetric Study of Cone-Beam CT-Based Radiation Treatment Planning Using a Patient-Specific Stepwise CT-Density Table

    Energy Technology Data Exchange (ETDEWEB)

    Chen, S; Le, Q; Mutaf, Y; Yi, B; D’Souza, W [University of Maryland School of Medicine, Baltimore, MD (United States)

    2015-06-15

    Purpose: To assess dose calculation accuracy of cone-beam CT (CBCT) based treatment plans using a patient-specific stepwise CT-density conversion table in comparison to conventional CT-based treatment plans. Methods: Unlike CT-based treatment planning which use fixed CT-density table, this study used patient-specific CT-density table to minimize the errors in reconstructed mass densities due to the effects of CBCT Hounsfield unit (HU) uncertainties. The patient-specific CT-density table was a stepwise function which maps HUs to only 6 classes of materials with different mass densities: air (0.00121g/cm3), lung (0.26g/cm3), adipose (0.95g/cm3), tissue (1.05 g/cm3), cartilage/bone (1.6g/cm3), and other (3g/cm3). HU thresholds to define different materials were adjusted for each CBCT via best match with the known tissue types in these images. Dose distributions were compared between CT-based plans and CBCT-based plans (IMRT/VMAT) for four types of treatment sites: head and neck (HN), lung, pancreas, and pelvis. For dosimetric comparison, PTV mean dose in both plans were compared. A gamma analysis was also performed to directly compare dosimetry in the two plans. Results: Compared to CT-based plans, the differences for PTV mean dose were 0.1% for pelvis, 1.1% for pancreas, 1.8% for lung, and −2.5% for HN in CBCT-based plans. The gamma passing rate was 99.8% for pelvis, 99.6% for pancreas, and 99.3% for lung with 3%/3mm criteria, and 80.5% for head and neck with 5%/3mm criteria. Different dosimetry accuracy level was observed: 1% for pelvis, 3% for lung and pancreas, and 5% for head and neck. Conclusion: By converting CBCT data to 6 classes of materials for dose calculation, 3% of dose calculation accuracy can be achieved for anatomical sites studied here, except HN which had a 5% accuracy. CBCT-based treatment planning using a patient-specific stepwise CT-density table can facilitate the evaluation of dosimetry changes resulting from variation in patient anatomy.

  6. Comparative study of patellar subluxation syndrome and normal group using axial radiography and CT

    Energy Technology Data Exchange (ETDEWEB)

    Kitagawa, Mamoru; Tomonaga, Kunio; Egawa, Tadashi; Nakamura, Yasushi; Gotoh, Shoji; Mihara, Shigeru (Nagasaki Municipal Hospital (Japan))

    1989-10-01

    A comparative study was conducted on the 20 knees of 10 females with normal knee joints (age, 22-35 years) and on 7 knees of 7 patients with subluxation syndrome (age, 15-24 years), using axial radiography and CT. In axial radiography where the angle of knee flexion was 30 deg or 60 deg, no significant difference was recognized between the two groups with respect to tilting angle, patellofemoral angle, congruence angle and lateral shift. However, a significant difference was found using CT. Thus, CT was considered useful for diagnosis. Because of these results, all 7 cases underwent surgery for detachment of the lateral side and tightening of the medial side. Three cases underwent shifting of the tibial tuberosity to the anteromedial side, resulting in a favourable outcome. Here, we report the study. (author).

  7. Whole-brain CT perfusion and CT angiography assessment of Moyamoya disease before and after surgical revascularization: preliminary study with 256-slice CT.

    Directory of Open Access Journals (Sweden)

    Jun Zhang

    Full Text Available BACKGROUND/AIMS: The 256-slice CT enables the entire brain to be scanned in a single examination. We evaluated the application of 256-slice whole-brain CT perfusion (CTP in determining graft patency as well as investigating cerebral hemodynamic changes in Moyamoya disease before and after surgical revascularization. METHODS: Thirty-nine cases of Moyamoya disease were evaluated before and after surgical revascularization with 256-slice CT. Whole-brain perfusion images and dynamic 3D CT angiographic images generated from perfusion source data were obtained in all patients. Cerebral blood flow (CBF, cerebral blood volume (CBV, time to peak (TTP and mean transit time (MTT of one hemisphere in the region of middle cerebral artery (MCA distribution and contralateral mirroring areas were measured. Relative CTP values (rCBF, rCBV, rTTP, rMTT were also obtained. Differences in pre- and post- operation perfusion CT values were assessed with paired t test or matched-pairs signed-ranks test. RESULTS: Preoperative CBF, MTT and TTP of potential surgical side were significantly different from those of contralateral side (P<0.01 for all. All graft patencies were displayed using the 3D-CTA images. Postoperative CBF, rCBF and rCBV values of surgical side in the region of MCA were significantly higher than those before operation (P<0.01 for all. Postoperative MTT, TTP, rMTT and rTTP values of the surgical side in the region of MCA were significantly lower than those before operation (P<0.05 for all. CONCLUSION: The 256-slice whole-brain CTP can be used to evaluate cerebral hemodynamic changes in Moyamoya disease before and after surgery and the 3D-CTA is useful for assessing the abnormalities of intracranial arteries and graft patencies.

  8. A Screening Study on Dermatoses in Pregnancy

    Science.gov (United States)

    Tharini, GK

    2017-01-01

    Introduction Pregnancy produces many cutaneous changes, some of which are specifically related to pregnancy (dermatoses of pregnancy), some are modifiable by pregnancy and others that are common are named physiologic. These physiologic skin changes, usually do not impair the health of the mother or the fetus but some of them can be cosmetically significant and of importance to the dermatologist. Aim The present study was undertaken to find out the prevalence of the physiological and pathological skin changes in pregnancy, and to correlate the prevalence of the major cutaneous changes and diseases in relation to different trimesters of pregnancy and with gravidity. Materials and Methods A cross-sectional study was conducted during the period of August 2008 to August 2010. Ethical clearance was sought from Institutional Ethical Committee. Five hundred pregnant women were randomly selected, irrespective of the duration of pregnancy and gravidity. Detailed history and complete dermatological examination was done. Results were tabulated and analysed. Statistical analysis was done by Fisher’s exact test and Chi square test. Results Physiological skin changes were seen in 94.8% of cases, with pigmentary changes being more common (90.8%). Specific dermatoses of pregnancy were observed in 14% of cases with pruritus gravidarum being the most common (10.4%). Prevalence of infection was found to 30.8% with fungal infection being the most common (23.8%). Exacerbations of systemic lupus erythematosus and neurofibromatosis was observed. Pigmentary changes, striae gravidarum and specific dermatoses of pregnancy were observed in statistically significant proportion in primigravidas and during third trimester. Conclusion This study emphasizes that the prevalence of physiological skin changes (94.8%) was much higher than specific dermatoses (14%), stressing the fact that in most instances, the skin problems during pregnancy needs only reassurance. But meticulous observation and

  9. Limiting CT radiation dose in children with craniosynostosis: phantom study using model-based iterative reconstruction

    Energy Technology Data Exchange (ETDEWEB)

    Kaasalainen, Touko; Lampinen, Anniina [University of Helsinki and Helsinki University Hospital, HUS Medical Imaging Center, Radiology, POB 340, Helsinki (Finland); University of Helsinki, Department of Physics, Helsinki (Finland); Palmu, Kirsi [University of Helsinki and Helsinki University Hospital, HUS Medical Imaging Center, Radiology, POB 340, Helsinki (Finland); School of Science, Aalto University, Department of Biomedical Engineering and Computational Science, Helsinki (Finland); Reijonen, Vappu; Kortesniemi, Mika [University of Helsinki and Helsinki University Hospital, HUS Medical Imaging Center, Radiology, POB 340, Helsinki (Finland); Leikola, Junnu [University of Helsinki and Helsinki University Hospital, Department of Plastic Surgery, Helsinki (Finland); Kivisaari, Riku [University of Helsinki and Helsinki University Hospital, Department of Neurosurgery, Helsinki (Finland)

    2015-09-15

    Medical professionals need to exercise particular caution when developing CT scanning protocols for children who require multiple CT studies, such as those with craniosynostosis. To evaluate the utility of ultra-low-dose CT protocols with model-based iterative reconstruction techniques for craniosynostosis imaging. We scanned two pediatric anthropomorphic phantoms with a 64-slice CT scanner using different low-dose protocols for craniosynostosis. We measured organ doses in the head region with metal-oxide-semiconductor field-effect transistor (MOSFET) dosimeters. Numerical simulations served to estimate organ and effective doses. We objectively and subjectively evaluated the quality of images produced by adaptive statistical iterative reconstruction (ASiR) 30%, ASiR 50% and Veo (all by GE Healthcare, Waukesha, WI). Image noise and contrast were determined for different tissues. Mean organ dose with the newborn phantom was decreased up to 83% compared to the routine protocol when using ultra-low-dose scanning settings. Similarly, for the 5-year phantom the greatest radiation dose reduction was 88%. The numerical simulations supported the findings with MOSFET measurements. The image quality remained adequate with Veo reconstruction, even at the lowest dose level. Craniosynostosis CT with model-based iterative reconstruction could be performed with a 20-μSv effective dose, corresponding to the radiation exposure of plain skull radiography, without compromising required image quality. (orig.)

  10. Study of CT head scans using different voltages: image quality evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Pacheco de Freitas C, I.; Prata M, A. [Centro Federal de Educacao Tecnologica de Minas Gerais, Centro de Engenharia Biomedica, Av. Amazonas 5253, 30421-169 Nova Suica, Belo Horizonte, Minas Gerais (Brazil); Alonso, T. C. [Centro de Desenvolvimento da Tecnologia Nuclear / CNEN, Av. Pte. Antonio Carlos 6627, 31270-901 Pampulha, Belo Horizonte, Minas Gerais (Brazil); Santana, P., E-mail: iarapfcorrea@gmail.com [Universidade Federal de Minas Gerais, Departamento de Anatomia e Imagem, Av. Prof. Alfredo Balena 190, 30130-100 Belo Horizonte, Minas Gerais (Brazil)

    2016-10-15

    Computed tomography (CT) was introduced to medical practice in 1972. It generates images recognized by high diagnostic potential. CT allows investigation of structures in the human body inaccessible by conventional image methods, replacing invasive methods in many cases. Noise is a kind of variation of brightness observed on CT images, and it is inherent to this method. The magnitude of the noise is determined by the standard deviation of CT numbers of a region of interest in a homogeneous material. The aim of this study is to analyze the noise in head CT images generated by different acquisition protocols using four voltage values. Five different scans were performed using a female Alderson phantom and their images were analyzed with the RadiAnt software. With the average HU values and standard deviation of each scan, the values of noise were calculated in some region of interest. The obtained noise values were compared and it was observed that the 140 kV voltage promotes the in the lower noise in the image, resulting in better image quality. The results also show that the parameters, such as voltage and current, can be adjusted so that the noise can be decreased. Thus, acquisition protocols may be adapted to produce images with diagnostic quality and lower doses in patient. (Author)

  11. Detection of pulmonary fat embolism with dual-energy CT: an experimental study in rabbits

    Energy Technology Data Exchange (ETDEWEB)

    Tang, Chun Xiang; Zhou, Chang Sheng; Zhao, Yan E.; Han, Zong Hong; Qi, Li; Zhang, Long Jiang; Lu, Guang Ming [Medical School of Nanjing University, Department of Medical Imaging, Jinling Hospital, Nanjing, Jiangsu (China); Schoepf, U.J. [Medical School of Nanjing University, Department of Medical Imaging, Jinling Hospital, Nanjing, Jiangsu (China); Medical University of South Carolina, Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Charleston, SC (United States); Mangold, Stefanie; Ball, B.D. [Medical University of South Carolina, Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Charleston, SC (United States)

    2017-04-15

    To evaluate the use of dual-energy CT imaging of the lung perfused blood volume (PBV) for the detection of pulmonary fat embolism (PFE). Dual-energy CT was performed in 24 rabbits before and 1 hour, 1 day, 4 days and 7 days after artificial induction of PFE via the right ear vein. CT pulmonary angiography (CTPA) and lung PBV images were evaluated by two radiologists, who recorded the presence, number, and location of PFE on a per-lobe basis. Sensitivity, specificity, and accuracy of CTPA and lung PBV for detecting PFE were calculated using histopathological evaluation as the reference standard. A total of 144 lung lobes in 24 rabbits were evaluated and 70 fat emboli were detected on histopathological analysis. The overall sensitivity, specificity and accuracy were 25.4 %, 98.6 %, and 62.5 % for CTPA, and 82.6 %, 76.0 %, and 79.2 % for lung PBV. Higher sensitivity (p < 0.001) and accuracy (p < 0.01), but lower specificity (p < 0.001), were found for lung PBV compared with CTPA. Dual-energy CT can detect PFE earlier than CTPA (all p < 0.01). Dual-energy CT provided higher sensitivity and accuracy in the detection of PFE as well as earlier detection compared with conventional CTPA in this animal model study. (orig.)

  12. Detection of pulmonary fat embolism with dual-energy CT: an experimental study in rabbits.

    Science.gov (United States)

    Tang, Chun Xiang; Zhou, Chang Sheng; Zhao, Yan E; Schoepf, U Joseph; Mangold, Stefanie; Ball, B Devon; Han, Zong Hong; Qi, Li; Zhang, Long Jiang; Lu, Guang Ming

    2017-04-01

    To evaluate the use of dual-energy CT imaging of the lung perfused blood volume (PBV) for the detection of pulmonary fat embolism (PFE). Dual-energy CT was performed in 24 rabbits before and 1 hour, 1 day, 4 days and 7 days after artificial induction of PFE via the right ear vein. CT pulmonary angiography (CTPA) and lung PBV images were evaluated by two radiologists, who recorded the presence, number, and location of PFE on a per-lobe basis. Sensitivity, specificity, and accuracy of CTPA and lung PBV for detecting PFE were calculated using histopathological evaluation as the reference standard. A total of 144 lung lobes in 24 rabbits were evaluated and 70 fat emboli were detected on histopathological analysis. The overall sensitivity, specificity and accuracy were 25.4 %, 98.6 %, and 62.5 % for CTPA, and 82.6 %, 76.0 %, and 79.2 % for lung PBV. Higher sensitivity (p PFE earlier than CTPA (all p PFE as well as earlier detection compared with conventional CTPA in this animal model study. • Fat embolism occurs commonly in patients with traumatic bone injury. • Dual-energy CT improves diagnostic performance for pulmonary fat embolism detection. • Dual-energy CT can detect pulmonary fat embolism earlier than CTPA.

  13. Screening for Lung Cancer

    Science.gov (United States)

    Mazzone, Peter J.; Naidich, David P.; Bach, Peter B.

    2013-01-01

    Background: Lung cancer is by far the major cause of cancer deaths largely because in the majority of patients it is at an advanced stage at the time it is discovered, when curative treatment is no longer feasible. This article examines the data regarding the ability of screening to decrease the number of lung cancer deaths. Methods: A systematic review was conducted of controlled studies that address the effectiveness of methods of screening for lung cancer. Results: Several large randomized controlled trials (RCTs), including a recent one, have demonstrated that screening for lung cancer using a chest radiograph does not reduce the number of deaths from lung cancer. One large RCT involving low-dose CT (LDCT) screening demonstrated a significant reduction in lung cancer deaths, with few harms to individuals at elevated risk when done in the context of a structured program of selection, screening, evaluation, and management of the relatively high number of benign abnormalities. Whether other RCTs involving LDCT screening are consistent is unclear because data are limited or not yet mature. Conclusions: Screening is a complex interplay of selection (a population with sufficient risk and few serious comorbidities), the value of the screening test, the interval between screening tests, the availability of effective treatment, the risk of complications or harms as a result of screening, and the degree with which the screened individuals comply with screening and treatment recommendations. Screening with LDCT of appropriate individuals in the context of a structured process is associated with a significant reduction in the number of lung cancer deaths in the screened population. Given the complex interplay of factors inherent in screening, many questions remain on how to effectively implement screening on a broader scale. PMID:23649455

  14. A comparative study of the diagnostic accuracy on Waters view with CT scan in detecting midface fractures

    OpenAIRE

    Panjnoush M.; Shirani Gh.; Jozghanbari P.

    2006-01-01

    Background and Aim: In recent years, CT scan has become available as an alternative to conventional radiography. To date, the utility of Waters view in detecting midface fractures has been rarely evaluated. The aim of this study was to compare the diagnostic accuracy and reliability of Waters radiography with CT scan in detecting midface fractures. Materials and Methods: In this tests evaluation study, waters view and CT scan were performed for 42 patients with midface fracture admitted to ma...

  15. Thermodynamic Studies for Drug Design and Screening

    Science.gov (United States)

    Garbett, Nichola C.; Chaires, Jonathan B.

    2012-01-01

    Introduction A key part of drug design and development is the optimization of molecular interactions between an engineered drug candidate and its binding target. Thermodynamic characterization provides information about the balance of energetic forces driving binding interactions and is essential for understanding and optimizing molecular interactions. Areas covered This review discusses the information that can be obtained from thermodynamic measurements and how this can be applied to the drug development process. Current approaches for the measurement and optimization of thermodynamic parameters are presented, specifically higher throughput and calorimetric methods. Relevant literature for this review was identified in part by bibliographic searches for the period 2004 – 2011 using the Science Citation Index and PUBMED and the keywords listed below. Expert opinion The most effective drug design and development platform comes from an integrated process utilizing all available information from structural, thermodynamic and biological studies. Continuing evolution in our understanding of the energetic basis of molecular interactions and advances in thermodynamic methods for widespread application are essential to realize the goal of thermodynamically-driven drug design. Comprehensive thermodynamic evaluation is vital early in the drug development process to speed drug development towards an optimal energetic interaction profile while retaining good pharmacological properties. Practical thermodynamic approaches, such as enthalpic optimization, thermodynamic optimization plots and the enthalpic efficiency index, have now matured to provide proven utility in design process. Improved throughput in calorimetric methods remains essential for even greater integration of thermodynamics into drug design. PMID:22458502

  16. The effect of a chest imaging lecture on emergency department doctors' ability to interpret chest CT images: a randomized study.

    Science.gov (United States)

    Keijzers, Gerben; Sithirasenan, Vasugi

    2012-02-01

    To assess the chest computed tomography (CT) imaging interpreting skills of emergency department (ED) doctors and to study the effect of a CT chest imaging interpretation lecture on these skills. Sixty doctors in two EDs were randomized, using computerized randomization, to either attend a chest CT interpretation lecture or not to attend this lecture. Within 2 weeks of the lecture, the participants completed a questionnaire on demographic variables, anatomical knowledge, and diagnostic interpretation of 10 chest CT studies. Outcome measures included anatomical knowledge score, diagnosis score, and the combined overall score, all expressed as a percentage of correctly answered questions (0-100). Data on 58 doctors were analyzed, of which 27 were randomized to attend the lecture. The CT interpretation lecture did not have an effect on anatomy knowledge scores (72.9 vs. 70.2%), diagnosis scores (71.2 vs. 69.2%), or overall scores (71.4 vs. 69.5%). Twenty-nine percent of doctors stated that they had a systematic approach to chest CT interpretation. Overall self-perceived competency for interpreting CT imaging (brain, chest, abdomen) was low (between 3.2 and 5.2 on a 10-point Visual Analogue Scale). A single chest CT interpretation lecture did not improve chest CT interpretation by ED doctors. Less than one-third of doctors had a systematic approach to chest CT interpretation. A standardized systematic approach may improve interpretation skills.

  17. Thoracic CT in the ED: a study of thoracic computed tomography utilisation.

    LENUS (Irish Health Repository)

    Williams, E

    2010-02-01

    The aim of this retrospective study was to investigate the use of thoracic Computed Tomography (CT) in the Emergency Department of a Dublin Academic Teaching Hospital over a six month period. Data was retrieved using the hospital\\'s computerised information system. There were 202 referrals in total for thoracic CT from the Emergency Department during this time period. The most common indication for thoracic CT referral was for the investigation of pulmonary embolism with 127 (63%) referrals. There were 40 (25%) referrals for suspected malignancy and lung disease, whilst 8 (4%) of the referrals were for investigation of thoracic aortic dissection, 8 (4%) for infection, and 6 (3%) were for investigation of thoracic injury. Only 8 (4%) of all referrals were for investigation of injury as a result of chest trauma.

  18. Comparative study of myelography with postmyelographic CT in cervical spondylosis and herniated disk

    Energy Technology Data Exchange (ETDEWEB)

    Jung, Kyoon Soon; Park, Yong Tae; Choi, Woo Suk; Lee, Sun Wha; Lim, Jae Hoon [Kyung Hee University College of Medicine, Seoul (Korea, Republic of)

    1988-10-15

    Eight patients, who had symptoms and signs of cervical spondylosis and/or disk were studied with myelography (using Omnipaque) followed by postmyelographic computed tomography to evaluate the relative efficacy of these two methods in the determination of cervical herniation and spondylosis. Thirty nine levels in 26 patients were confirmed by surgery. Of these, 20 levels proved to have operative evidence of herniated disk. Postmyelographic CT adds useful information to the myelographic findings. Cord and root compression are better evaluated and osteopathy can be differentiated from disk herniation. In osteopathy, myelography was as diagnostic as postmyelographic CT. But, disk herniation was identified in 70% (14/20 levels) with postmyelographic CT and only in 15% (3/20 levels) with myelography.

  19. Imaging study of a phase-sensitive breast-CT system in continuous acquisition mode

    Science.gov (United States)

    Delogu, P.; Golosio, B.; Fedon, C.; Arfelli, F.; Bellazzini, R.; Brez, A.; Brun, F.; Di Lillo, F.; Dreossi, D.; Mettivier, G.; Minuti, M.; Oliva, P.; Pichera, M.; Rigon, L.; Russo, P.; Sarno, A.; Spandre, G.; Tromba, G.; Longo, R.

    2017-01-01

    The SYRMA-CT project aims to set-up the first clinical trial of phase-contrast breast Computed Tomography with synchrotron radiation at the SYRMEP beamline of Elettra, the Italian synchrotron light source. The challenge in a dedicated breast CT is to match a high spatial resolution with a low dose level. In order to fulfil these requirements, the SYRMA-CT project uses a large area CdTe single photon counting detector (Pixirad-8), simultaneous algebraic reconstruction technique (SART) and phase retrieval pre-processing. This work investigates the imaging performances of the system in a continuous acquisition mode and with a low dose level towards the clinical application. A custom test object and a large surgical sample have been studied.

  20. Ironmaking Process Alternative Screening Study, Volume 1

    Energy Technology Data Exchange (ETDEWEB)

    Lockwood Greene, . .

    2005-01-06

    Iron in the United States is largely produced from iron ore mined in the United States or imported from Canada or South America. The iron ore is typically smelted in Blast Furnaces that use primarily iron ore, iron concentrate pellets metallurgical coke, limestone and lime as the raw materials. Under current operating scenarios, the iron produced from these Blast Furnaces is relatively inexpensive as compared to current alternative iron sources, e.g. direct iron reduction, imported pig iron, etc. The primary problem the Blast Furnace Ironmaking approach is that many of these Blast furnaces are relatively small, as compared to the newer, larger Blast Furnaces; thus are relatively costly and inefficient to operate. An additional problem is also that supplies of high-grade metallurgical grade coke are becoming increasingly in short supply and costs are also increasing. In part this is due to the short supply and costs of high-grade metallurgical coals, but also this is due to the increasing necessity for environmental controls for coke production. After year 2003 new regulations for coke product environmental requirement will likely be promulgated. It is likely that this also will either increase the cost of high-quality coke production or will reduce the available domestic U.S. supply. Therefore, iron production in the United States utilizing the current, predominant Blast Furnace process will be more costly and would likely be curtailed due to a coke shortage. Therefore, there is a significant need to develop or extend the economic viability of Alternate Ironmaking Processes to at least partially replace current and declining blast furnace iron sources and to provide incentives for new capacity expansion. The primary conclusions of this comparative Study of Alternative Ironmaking Process scenarios are: (1) The processes with the best combined economics (CAPEX and OPEX impacts in the I.R.R. calculation) can be grouped into those Fine Ore based processes with no scrap

  1. Bronchial anatomy of left lung: a study of multi-detector row CT.

    Science.gov (United States)

    Zhao, Xinya; Ju, Yuanrong; Liu, Cheng; Li, Jianfeng; Huang, Min; Sun, Jian; Wang, Tao

    2009-02-01

    Familiarity with prevailing pattern and variations in the bronchial tree is not only essential for the anatomist to explain bronchial variation in bronchial specimens, but also useful for guiding bronchoscopy and instructing pulmonary segmental resection. The purpose of this study was designed to demonstrate various branching patterns of left lung with 3D images, with special attention given to identify the major types at transverse thin-section CT. Two hundred and sixteen patients with routine thorax scans were enrolled. The images of bronchial tree, virtual bronchoscopy were reconstructed using post-processing technique of multi-detector row CT. We attempted to classify the segmental bronchi by interpreting the post-processing images, and identified them in transverse thin-section CT. Our results showed that the segmental bronchial ramifications of the left superior lobe were classified into three types mainly, i.e., common stem of apical and posterior segmental bronchi (64%, 138/216); trifurcation (23%, 50/216); common stem of apical and anterior segmental bronchi (10%, 22/216), and they could be identified at two typical sections of transverse thin-section CT. There were two major types in left basal segmental bronchi, i.e., bifurcation (75%, 163/216), trifurcation (18%, 39/216), and they could also be identified at two typical sections of transverse thin-section CT. In conclusion, our study have offered simplified branching patterns of bronchi and demonstrated various unusual bronchial branching patterns perfectly with 3D images, and have also revealed how to identify the main branching patterns in transverse thin-section CT.

  2. Register-based studies of cancer screening effects

    DEFF Research Database (Denmark)

    Von Euler-Chelpin, My; Lynge, Elsebeth; Rebolj, Matejka

    2011-01-01

    INTRODUCTION: There are two organised cancer screening programmes in Denmark, against cervical and breast cancers. The aim with this study was to give an overview of the available register-based research regarding these two programmes, to demonstrate the usefulness of data from the national regis...

  3. Quality control of CT systems by automated monitoring of key performance indicators: a two-year study.

    Science.gov (United States)

    Nowik, Patrik; Bujila, Robert; Poludniowski, Gavin; Fransson, Annette

    2015-07-08

    The purpose of this study was to develop a method of performing routine periodical quality controls (QC) of CT systems by automatically analyzing key performance indicators (KPIs), obtainable from images of manufacturers' quality assurance (QA) phantoms. A KPI pertains to a measurable or determinable QC parameter that is influenced by other underlying fundamental QC parameters. The established KPIs are based on relationships between existing QC parameters used in the annual testing program of CT scanners at the Karolinska University Hospital in Stockholm, Sweden. The KPIs include positioning, image noise, uniformity, homogeneity, the CT number of water, and the CT number of air. An application (MonitorCT) was developed to automatically evaluate phantom images in terms of the established KPIs. The developed methodology has been used for two years in clinical routine, where CT technologists perform daily scans of the manufacturer's QA phantom and automatically send the images to MonitorCT for KPI evaluation. In the cases where results were out of tolerance, actions could be initiated in less than 10 min. 900 QC scans from two CT scanners have been collected and analyzed over the two-year period that MonitorCT has been active. Two types of errors have been registered in this period: a ring artifact was discovered with the image noise test, and a calibration error was detected multiple times with the CT number test. In both cases, results were outside the tolerances defined for MonitorCT, as well as by the vendor. Automated monitoring of KPIs is a powerful tool that can be used to supplement established QC methodologies. Medical physicists and other professionals concerned with the performance of a CT system will, using such methods, have access to comprehensive data on the current and historical (trend) status of the system such that swift actions can be taken in order to ensure the quality of the CT examinations, patient safety, and minimal disruption of service.

  4. Quantifying trabecular bone material anisotropy and orientation using low resolution clinical CT images: A feasibility study.

    Science.gov (United States)

    Nazemi, S Majid; Cooper, David M L; Johnston, James D

    2016-09-01

    Accounting for spatial variation of trabecular material anisotropy and orientation can improve the accuracy of quantitative computed tomography-based finite element (FE) modeling of bone. The objective of this study was to investigate the feasibility of quantifying trabecular material anisotropy and orientation using clinical computed tomography (CT). Forty four cubic volumes of interest were obtained from micro-CT images of the human radius. Micro-FE modeling was performed on the samples to obtain orthotropic stiffness entries as well as trabecular orientation. Simulated computed tomography images (0.32, 0.37, and 0.5mm isotropic voxel sizes) were created by resampling micro-CT images with added image noise. The gray-level structure tensor was used to derive fabric eigenvalues and eigenvectors in simulated CT images. For 'best case' comparison purposes, Mean Intercept Length was used to define fabric from micro-CT images. Regression was used in combination with eigenvalues, imaged density and FE to inversely derive the constants used in Cowin and Zysset-Curnier fabric-elasticity equations, and for comparing image derived fabric-elasticity stiffness entries to those obtained using micro-FE. Image derived eigenvectors (which indicated trabecular orientation) were then compared to orientation derived using micro-FE. When using clinically available voxel sizes, gray-level structure tensor derived fabric combined with Cowin's equations was able to explain 94-97% of the variance in orthotropic stiffness entries while Zysset-Curnier equations explained 82-88% of the variance in stiffness. Image derived orientation deviated by 4.4-10.8° from micro-FE derived orientation. Our results indicate potential to account for spatial variation of trabecular material anisotropy and orientation in subject-specific finite element modeling of bone using clinically available CT.

  5. Limited-preparation CT colonography in frail elderly patients: a feasibility study.

    LENUS (Irish Health Repository)

    Keeling, Aoife N

    2010-05-01

    Full colonic preparation can be onerous and may be poorly tolerated in frail elderly patients. The purpose of this study was to prospectively assess the image quality and diagnostic yield of limited-preparation CT colonography (CTC) in elderly patients with suspected colorectal cancer who were deemed medically unfit or unsuitable for colonoscopy.

  6. Study Finds Small Increase in Cancer Risk after Childhood CT Scans

    Science.gov (United States)

    A study published in the June 6, 2012, issue of The Lancet shows that radiation exposure from computed tomography (CT) scans in childhood results in very small but increased risks of leukemia and brain tumors in the first decade after exposure.

  7. Assessment of thermal sensitivity of CT during heating of liver : an ex vivo study

    NARCIS (Netherlands)

    Pandeya, G. D.; Greuter, M. J. W.; Schmidt, B.; Flohr, T.; Oudkerk, M.

    2012-01-01

    Objectives: The purpose of this study was to assess the thermal sensitivity of CT during heating of ex-vivo animal liver. Methods: Pig liver was indirectly heated from 20 to 90 degrees C by passage of hot air through a plastic tube. The temperature in the heated liver was measured using calibrated t

  8. Comparison of image quality in head CT studies with different dose-reduction strategies

    DEFF Research Database (Denmark)

    Johansen, Jeppe; Nielsen, Rikke; Fink-Jensen, Vibeke

    -reduction maneuvers is reduction of image quality due to image noise or artifacts. The aim of our study was therefore to find the best diagnostic images with lowest possible dose. We present results of dose- and image quality optimizing strategies of brain CT examinations at our institution. We compare sequential...

  9. Radiation dose from multidetector CT studies in children: results from the first Italian nationwide survey

    Energy Technology Data Exchange (ETDEWEB)

    Granata, Claudio [IRCCS Istituto Giannina Gaslini, Department of Radiology, Genoa (Italy); Origgi, Daniela; Palorini, Federica [Istituto Europeo di Oncologia, Department of Medical Physics, Milan (Italy); Matranga, Domenica [University of Palermo, Department of Sciences for Health Promotion and Mother and Child Care ' ' G. D' Alessandro' ' , Palermo (Italy); Salerno, Sergio [University of Palermo, Department of Medical and Forensic Biopathology and Biotechnologies, Section of Radiology, Palermo (Italy)

    2015-05-01

    Multidetector CT (MDCT) scanners have contributed to the widespread use of CT in paediatric imaging. However, concerns are raised for the associated radiation exposure. Very few surveys on radiation exposure from MDCT studies in children are available. The aim of this study was to outline the status of radiation exposure in children from MDCT practice in Italy. In this retrospective multicentre study we asked Italian radiology units with an MDCT scanner with at least 16 slices to provide dosimetric and acquisition parameters of CT examinations in three age groups (1-5, 6-10, 11-15 years) for studies of head, chest and abdomen. The dosimetric results were reported in terms of third-quartile volumetric CT dose index (CTDI{sub vol}) (mGy), size-specific dose estimate (SSDE) (mGy), dose length product (DLP) (mGy cm), and total DLP for multiphase studies. These results were compared with paediatric European and adult Italian published data. A multivariate analysis assessed the association of CTDI{sub vol} with patient characteristics and scanning modalities. We collected data from 993 MDCT examinations performed at 25 centres. For age groups 1-5 years, 6-10 years and 11-15 years, the CTDI{sub vol}, DLP and total DLP values were statistically significantly below the values observed in our analogous national survey in adults, although the difference decreased with increasing age. CTDI{sub vol} variability among centres was statistically significant (variance = 0.07; 95% confidence interval = 0.03-0.16; P < 0.001). This study reviewed practice in Italian centres performing paediatric imaging with MDCT scanners. The variability of doses among centres suggests that the use of standardised CT protocols should be encouraged. (orig.)

  10. Automated screening versus manual screening: a comparison of the ThinPrep imaging system and manual screening in a time study

    DEFF Research Database (Denmark)

    Schledermann, Doris; Hyldebrandt, Tina; Ejersbo, Dorthe;

    2007-01-01

    The ThinPrep Imaging System (TIS) is an automated system that assists cytotechnologists in the primary screening of ThinPrep liquid based cervical samples. Between June 1, 2004, and April 1, 2005, four experienced cytotechnologists participated in the study in which the duration of the screening ...

  11. Effect of listening to music and essential oil inhalation on patients undergoing screening CT colonography: a randomized controlled trial.

    Science.gov (United States)

    Nagata, Koichi; Iida, Nao; Kanazawa, Hidenori; Fujiwara, Masanori; Mogi, Tomohiro; Mitsushima, Toru; Lefor, Alan T; Sugimoto, Hideharu

    2014-12-01

    To prospectively evaluate the effect of listening to music and inhaling aroma oil on patients undergoing screening computed tomography colonography. Two hundred and twenty four participants were randomly allocated to one of the four groups including: (1) combined music and aroma, (2) music alone, (3) aroma alone, and (4)control. The visual analog scale for pain and a questionnaire were used for subjective outcomes. We also used a pre-test–post-test design to compare the differences in blood pressure and heart rate as objective outcomes. There were no statistical differences between the control group and other groups in the visual analog scale or changes in heart rate. Changes in blood pressure were similar. Participants reported good overall experiences. There were no differences in terms of overall satisfaction, pain rating, willingness to repeat the computed tomography colonography procedure in the future, or preference between colonoscopy and computed tomography colonography. More participants using music and/or aroma requested music and/or aroma during the next computed tomography colonography (P pain or discomfort and vital signs, participants who listened to music and inhaled aroma during the computed tomography colonography preferred music and aroma during the next computed tomography colonography. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  12. Screening study on new tumor marker periplakin for lung cancer

    Institute of Scientific and Technical Information of China (English)

    Shuqin Dai; Wei Li; Mian Kong; Yuzhen Zheng; Shuying Chen; Junye Wang; Linquan Zang

    2013-01-01

    Objective: The aim of this study was to use lung cancer targeting binding polypeptide ZS-9 to screen cDNA library of human lung cancer and obtain ZS-9 specific ligand to confirm tumor marker of non small-cell lung cancer. Methods: Artificially synthesize biotin labeled peptide ZS-9, anchored ZS-9 in the enzyme label plate coupled by avidin, used ZS-9 as probe to screen cDNA library of human lung cancer, after screening, obtained bacteriophage clone specifically binding with anchored polypeptide ZS-9. Extracted plasmid of bacteriophage and performed sequencing after amplified by PCR. Results: It was demonstrated by bioinformatic analysis on the sequence of ligand binded by lung cancer specific peptide ZS-9 that the ligand was the cytoskeletal protein periplakin on the surface of lung cancer cells, suggesting that periplakin might be a new marker for non-small-cell lung cancer in lung cancer. Conclusion: Use specific lung cancer binding peptide to screen new tumor marker periplakin in lung cancer and further studies on its biologic functions in genesis and development of lung cancer are still needed.

  13. In vivo longitudinal micro-CT study of bent long limb bones in rat offspring.

    Science.gov (United States)

    De Schaepdrijver, Luc; Delille, Peter; Geys, Helena; Boehringer-Shahidi, Christian; Vanhove, Christian

    2014-07-01

    Micro-computed X-ray tomography (micro-CT) has been reported as a reliable method to assess ex vivo rat and rabbit fetal skeletons in embryo-fetal developmental toxicity studies. Since micro-CT is a non-invasive imaging modality it has the potential for longitudinal, in vivo investigation of postnatal skeletal development. This is the first paper using micro-CT to assess the reversibility of drug-induced bent long bones in a longitudinal study from birth to early adulthood in rat offspring. Analysis of the scans obtained on postnatal Day 0, 7, 21 and 80 showed complete recovery or repair of the bent long limb bones (including the scapula) within the first 3 weeks. When assessing risk the ability to demonstrate recovery is highly advantageous when interpreting such transient skeletal change. In summary, in vivo micro-CT of small laboratory animals can aid in non-clinical safety assessment, particularly for specific mechanistic purposes or to address a particular concern in developmental biology.

  14. A Pilot Study of 18F-FLT PET/CT in Pediatric Lymphoma

    Directory of Open Access Journals (Sweden)

    Danny L. Costantini

    2016-01-01

    Full Text Available We performed an observational pilot study of 18F-FLT PET/CT in pediatric lymphoma. Eight patients with equivocal 18F-FDG PET/CT underwent imaging with 18F-FLT PET/CT. No immediate adverse reactions to 18F-FLT were observed. Compared to 18F-FDG, 18F-FLT uptake was significantly higher in bone marrow and liver (18F-FLT SUV 8.6±0.6 and 5.0±0.3, versus 18F-FDG SUV 1.9±0.1 and 3.4±0.7, resp., p<0.05. In total, 15 lesions were evaluated with average 18F-FDG and 18F-FLT SUVs of 2.6±0.1 and 2.0±0.4, respectively. Nonspecific uptake in reactive lymph nodes and thymus was observed. Future studies to assess the clinical utility of 18F-FLT PET/CT in pediatric lymphoma are planned.

  15. Effect of listening to music and essential oil inhalation on patients undergoing screening CT colonography: A randomized controlled trial

    Energy Technology Data Exchange (ETDEWEB)

    Nagata, Koichi, E-mail: Nagata7@aol.com [Department of Radiology, Kameda Medical Center, 929 Higashi-cho, Kamogawa, Chiba 296-8602 (Japan); Department of Radiology, Jichi Medical University, 3311-1 Yakushiji, Shimotsuke, Tochigi 329-0498 (Japan); Cancer Screening Technology Division, Research Center for Cancer Prevention and Screening, National Cancer Center, 5-1-1, Tsukiji, Chuo-ku, Tokyo 104-0045 (Japan); Iida, Nao, E-mail: n.iida-xray@kameda.jp [Department of Radiology, Kameda Medical Center Makuhari, 1-3, Nakase, Mihama-ku, Chiba 261-8501 (Japan); Kanazawa, Hidenori, E-mail: r0713hk@jichi.ac.jp [Department of Radiology, Jichi Medical University, 3311-1 Yakushiji, Shimotsuke, Tochigi 329-0498 (Japan); Fujiwara, Masanori, E-mail: m_fujiwara@kameda.jp [Department of Radiology, Kameda Medical Center Makuhari, 1-3, Nakase, Mihama-ku, Chiba 261-8501 (Japan); Mogi, Tomohiro, E-mail: mogi-xray@kameda.jp [Department of Radiology, Kameda Medical Center Makuhari, 1-3, Nakase, Mihama-ku, Chiba 261-8501 (Japan); Mitsushima, Toru, E-mail: mitsushima@kameda.jp [Department of Gastroenterology, Kameda Medical Center Makuhari, 1-3, Nakase, Mihama-ku, Chiba 261-8501 (Japan); Lefor, Alan T., E-mail: alefor@jichi.ac.jp [Department of Surgery, Jichi Medical University, 3311-1 Yakushiji, Shimotsuke, Tochigi 329-0498 (Japan); Sugimoto, Hideharu, E-mail: sugimoto@jichi.ac.jp [Department of Radiology, Jichi Medical University, 3311-1 Yakushiji, Shimotsuke, Tochigi 329-0498 (Japan)

    2014-12-15

    Highlights: • Music does not decrease patients’ perceived pain or acceptance during CTC. • Aromatherapy does not affect patients’ perceived pain or experience during CTC. • Music and aroma had little effect on vital signs during CTC. • More participants who listened to music requested music during the next CTC. • More participants who inhaled aroma requested aroma during the next CTC. - Abstract: Objective: To prospectively evaluate the effect of listening to music and inhaling aroma oil on patients undergoing screening computed tomography colonography. Materials and methods: Two hundred and twenty four participants were randomly allocated to one of the four groups including: (1) combined music and aroma, (2) music alone, (3) aroma alone, and (4) control. The visual analog scale for pain and a questionnaire were used for subjective outcomes. We also used a pre-test–post-test design to compare the differences in blood pressure and heart rate as objective outcomes. Results: There were no statistical differences between the control group and other groups in the visual analog scale or changes in heart rate. Changes in blood pressure were similar. Participants reported good overall experiences. There were no differences in terms of overall satisfaction, pain rating, willingness to repeat the computed tomography colonography procedure in the future, or preference between colonoscopy and computed tomography colonography. More participants using music and/or aroma requested music and/or aroma during the next computed tomography colonography (P < 0.0001). Conclusion: Although audio and olfactory intervention had little effect on perceived pain or discomfort and vital signs, participants who listened to music and inhaled aroma during the computed tomography colonography preferred music and aroma during the next computed tomography colonography.

  16. Scintillating screens study for LEIR/LHC heavy ion beams

    CERN Document Server

    Bal, C; Lefèvre, T; Scrivens, R; Taborelli, M

    2005-01-01

    It has been observed on different machines that scintillating ceramic screens (like chromium doped alumina) are quickly damaged by low energy ion beams. These particles are completely stopped on the surface of the screens, inducing both a high local temperature increase and the electrical charging of the material. A study has been initiated to understand the limiting factors and the damage mechanisms. Several materials, ZrO2, BN and Al2O3, have been tested at CERN on LINAC3 with 4.2MeV/u lead ions. Alumina (Al2O3) is used as the reference material as it is extensively used in beam imaging systems. Boron nitride (BN) has better thermal properties than Alumina and Zirconium oxide (ZrO2). BN has in fact the advantage of increasing its electrical conductivity when heated. This contribution presents the results of the beam tests, including the post-mortem analysis of the screens and the outlook for further measurements. The strategy for the choice of the screens for the Low Energy Ion Ring (LEIR), currently under ...

  17. Evaluation of adverse events and imaging quality in contrast-enhanced abdominal CT using generic CT contrast developed in South Korea: A multicenter prospective observational study

    Energy Technology Data Exchange (ETDEWEB)

    Kim, You Sung [Dept. of Radiology, Ilsan Paik Hospital, College of Medicine, Inje University, Goyang (Korea, Republic of); Jung, Seung Eun; Park, Micheal Yong; Rha, Sung Eun [Dept. of Radiology, Seoul St. Mary' s Hospital, College of Medicine, The Catholic University of Korea, Seoul (Korea, Republic of); Lee, Soo Rim [Dept. of Radiology, Uijeongbu St. Mary' s Hospital, College of Medicine, The Catholic University of Korea, Uijeongbu (Korea, Republic of); Hwang, Seong Su [Dept. of Radiology, St. Vincent Hospital, College of Medicine, The Catholic University of Korea, Suwon (Korea, Republic of); Lim, Yeon Soo [Dept. of Radiology, Bucheon St. Mary' s Hospital, College of Medicine, The Catholic University of Korea, Bucheon (Korea, Republic of); Park, Jeong Mi [Dept. of Radiology, Yeouido St. Mary' s Hospital, College of Medicine, The Catholic University of Korea, Seoul (Korea, Republic of)

    2017-02-15

    The purpose of this study is to evaluate the clinical safety and usefulness of the Prosure®300 in contrast-enhanced abdominal CT. This prospective study was approved by our center's Institutional Review Board. This study included 727 patients in four hospitals who underwent contrast-enhanced abdominal CT using Prosure®300 from December 2010 to June 2011. Adverse events were classified into minor and major adverse events. Logistic regression analysis was used to evaluate the relationship between adverse events and patient gender, age, underlying disease, and amount of injected contrast agent. Two radiologists independently evaluated imaging quality as poor, insufficient, sufficient, good, or very good. One hundred seventy-six out of 727 patients complained of adverse events, but most of them were minor adverse events. Five patients complained of dyspnea and one patient had hoarseness, but recovered without treatment. The rate of adverse events was significantly higher in men (p = 0.011), and a greater amount of injected contrast agent was related to a higher rate of adverse events (p = 0.000). Imaging quality was evaluated as 'good' or 'very good' in all cases. Prosure®300, a generic CT contrast agent developed in South Korea, can be used in contrast-enhanced abdominal CT.

  18. An ergonomics study of thumb movements on smartphone touch screen.

    Science.gov (United States)

    Xiong, Jinghong; Muraki, Satoshi

    2014-01-01

    This study investigated the relationships between thumb muscle activity and thumb operating tasks on a smartphone touch screen with one-hand posture. Six muscles in the right thumb and forearm were targeted in this study, namely adductor pollicis, flexor pollicis brevis, abductor pollicis brevis (APB), abductor pollicis longus, first dorsal interosseous (FDI) and extensor digitorum. The performance measures showed that the thumb developed fatigue rapidly when tapping on smaller buttons (diameter: 9 mm compared with 3 mm), and moved more slowly in flexion-extension than in adduction-abduction orientation. Meanwhile, the electromyography and perceived exertion values of FDI significantly increased in small button and flexion-extension tasks, while those of APB were greater in the adduction-abduction task. This study reveals that muscle effort among thumb muscles on a touch screen smartphone varies according to the task, and suggests that the use of small touch buttons should be minimised for better thumb performance.

  19. C-arm CT for histomorphometric evaluation of lumbar spine trabecular microarchitecture: a study on anorexia nervosa patients.

    Science.gov (United States)

    Phan, C M; Khalilzadeh, O; Dinkel, J; Wang, I S; Bredella, M A; Misra, M; Miller, K K; Klibanski, A; Gupta, R

    2013-07-01

    Bone histomorphometry measurements require high spatial resolution that may not be feasible using multidetector CT (MDCT). This study evaluated the trabecular microarchitecture of lumbar spine using MDCT and C-arm CT in a series of young adult patients with anorexia nervosa (AN). 11 young females with AN underwent MDCT (anisotropic resolution with a slice thickness of ~626 μm) and C-arm CT (isotropic resolution of ~200 µm). Standard histomorphometric parameters the of L1 vertebral body, namely the apparent trabecular bone volume fraction (BV/TV), trabecular thickness (TbTh), trabecular number (TbN) and trabecular separation (TbSp), were analysed using MicroView software (GE Healthcare, Piscataway, NJ). Bone mineral density (BMD) was measured using dual-energy X-ray absorptiometry. Trabecular parameters derived from MDCT and C-arm CT were compared, and their association with BMD parameters was evaluated. Histomorphometric parameters derived from C-arm CT, namely TbTh, TbN and TbSp, were significantly different from the corresponding MDCT parameters. There were no significant correlations between C-arm CT-derived parameters and the corresponding MDCT-derived parameters. C-arm CT-derived parameters were significantly (pC-arm CT, was significantly associated with body mass index (r=0.636) and ideal body weight (r=0.730) (pC-arm CT more accurately captures the histomorphometric parameters of trabecular morphology than MDCT in patients with AN.

  20. A study on using texture analysis methods for identifying lobar fissure regions in isotropic CT images.

    Science.gov (United States)

    Wei, Q; Hu, Y

    2009-01-01

    The major hurdle for segmenting lung lobes in computed tomographic (CT) images is to identify fissure regions, which encase lobar fissures. Accurate identification of these regions is difficult due to the variable shape and appearance of the fissures, along with the low contrast and high noise associated with CT images. This paper studies the effectiveness of two texture analysis methods - the gray level co-occurrence matrix (GLCM) and the gray level run length matrix (GLRLM) - in identifying fissure regions from isotropic CT image stacks. To classify GLCM and GLRLM texture features, we applied a feed-forward back-propagation neural network and achieved the best classification accuracy utilizing 16 quantized levels for computing the GLCM and GLRLM texture features and 64 neurons in the input/hidden layers of the neural network. Tested on isotropic CT image stacks of 24 patients with the pathologic lungs, we obtained accuracies of 86% and 87% for identifying fissure regions using the GLCM and GLRLM methods, respectively. These accuracies compare favorably with surgeons/radiologists' accuracy of 80% for identifying fissure regions in clinical settings. This shows promising potential for segmenting lung lobes using the GLCM and GLRLM methods.

  1. Evaluation of anterior mediastinal solid tumors by CT perfusion: a preliminary study.

    Science.gov (United States)

    Bakan, Selim; Kandemirli, Sedat Giray; Dikici, Atilla Süleyman; Erşen, Ezel; Yıldırım, Onur; Samancı, Cesur; Batur, Şebnem; Çebi Olgun, Deniz; Kantarcı, Fatih; Akman, Canan

    2017-01-01

    We aimed to assess the role of computed tomography (CT) perfusion in differentiation of thymoma from thymic hyperplasia, lymphoma, thymic carcinoma, and lung cancer invading anterior mediastinum. In this study, 25 patients with an anterior mediastinal lesion underwent CT perfusion imaging from January 2015 to February 2016. Diagnoses included thymoma (n=7), thymic hyperplasia (n=8), lymphoma (n=4), thymic carcinoma (n=3), and invasive lung cancer (n=3). Lymphoma, thymic carcinoma, and lung cancer were grouped as malignant tumors for statistical analysis. Values for blood flow, blood volume, and permeability surface were measured in CT perfusion. Blood flow and blood volume values were higher in thymoma in comparison to thymic hyperplasia; however, the difference was not statistically significant. Blood volume values were significantly higher in thymoma (mean, 11.4 mL/100 mL; range, 5.2-20.2 mL/100 mL) compared with lymphoma (mean, 5.3 mL/100 mL; range, 2.5-7.2 mL/100 mL) (P = 0.023). Blood flow and blood volume values were significantly higher in thymoma compared with non-thymoma malignant tumors (P = 0.025). CT perfusion is helpful in differentiating thymoma from non-thymoma malignancies including lymphoma, thymic carcinoma, and invasive lung cancer involving the anterior mediastinum.

  2. Oncological Patient Anxiety in Imaging Studies: the PET/CT Example.

    Science.gov (United States)

    Abreu, Carla; Grilo, Ana; Lucena, Filipa; Carolino, Elisabete

    2016-07-02

    The purpose of this study was to investigate the subjective perception of anxiety pre- and post-procedure, and explore the relationship between demographic, clinical variables and cancer patients' anxiety during a positron emission tomography/computed tomography (PET/CT) scan. Two hundred and thirty-two oncological out patients, with clinical indication for performing an (18)F-2-fluoro-2-deoxy-D-glucose ((18)F-FDG) PET/CT scan and attending a nuclear medicine (NM) department, participated in the study. Patients' anxiety and subjective experience of PET/CT were examined using two self-report questionnaires. The pre-procedure questionnaire focused on demographic information, level of knowledge regarding the scan and subjective perception of anxiety before the procedure. The post-procedure questionnaire included the subjective perception anxiety after the procedure, information adequacy and satisfaction with the NM department. The self-reported data indicate that patients were anxious during PET/CT. Furthermore, our data revealed a significant difference between the anxiety pre-procedure and post-procedure (z = -3909, p < 0.05), in which the anxiety pre-procedure has significantly higher values. No significant correlation was found between anxiety and age of the patients, education levels, adequacy of information or satisfaction with the NM Department. Perception of anxiety post-procedure differs between gender (U = 5641, p = 0.033). In conclusion, PET/CT generated anxiety levels in oncological patients, especially before the procedure. Although patients seemed to be satisfied with information delivered by staff and with the NM Department, attention has to be focused on effective interventions strategies that help patients to reduce anxiety.

  3. Myocardial defect detection using PET-CT: phantom studies.

    Directory of Open Access Journals (Sweden)

    Eugene S Mananga

    Full Text Available It is expected that both noise and activity distribution can have impact on the detectability of a myocardial defect in a cardiac PET study. In this work, we performed phantom studies to investigate the detectability of a defect in the myocardium for different noise levels and activity distributions. We evaluated the performance of three reconstruction schemes: Filtered Back-Projection (FBP, Ordinary Poisson Ordered Subset Expectation Maximization (OP-OSEM, and Point Spread Function corrected OSEM (PSF-OSEM. We used the Channelized Hotelling Observer (CHO for the task of myocardial defect detection. We found that the detectability of a myocardial defect is almost entirely dependent on the noise level and the contrast between the defect and its surroundings.

  4. Myocardial defect detection using PET-CT: phantom studies.

    Science.gov (United States)

    Mananga, Eugene S; El Fakhri, Georges; Schaefferkoetter, Joshua; Bonab, Ali A; Ouyang, Jinsong

    2014-01-01

    It is expected that both noise and activity distribution can have impact on the detectability of a myocardial defect in a cardiac PET study. In this work, we performed phantom studies to investigate the detectability of a defect in the myocardium for different noise levels and activity distributions. We evaluated the performance of three reconstruction schemes: Filtered Back-Projection (FBP), Ordinary Poisson Ordered Subset Expectation Maximization (OP-OSEM), and Point Spread Function corrected OSEM (PSF-OSEM). We used the Channelized Hotelling Observer (CHO) for the task of myocardial defect detection. We found that the detectability of a myocardial defect is almost entirely dependent on the noise level and the contrast between the defect and its surroundings.

  5. Regret on choice of colorectal cancer screening modality was associated with poorer screening compliance: a 4-year prospective cohort study.

    Directory of Open Access Journals (Sweden)

    Martin C S Wong

    Full Text Available Very few studies examined the issue of regret on choosing colorectal cancer (CRC screening tests. We evaluated the determinants of regret and tested the hypothesis that regret over screening choices was associated with poorer screening compliance.A bowel cancer screening centre invited all Hong Kong citizens aged 50-70 years who were asymptomatic of CRC to participate in free-of-charge screening programmes. Upon attendance they attended health seminars on CRC and its screening, and were offered an option to choose yearly faecal immunochemical test (FIT for up to four years vs. one direct colonoscopy. They were not allowed to switch the screening option after decision. A self-administered, four-item validated survey was used to assess whether they regretted over their choice (> 2 = regretful from a scale of 0 [no regret]-5 [extreme regret]. A binary logistic regression model evaluated if initial regret over their choice was associated with poorer programme compliance.From 4,341 screening participants who have chosen FIT or colonoscopy, 120 (2.8% regretted over their decision and 1,029 (23.7% were non-compliant with the screening programme. Younger subjects and people who felt pressure when making their decision were associated with regret. People who regretted their decision were 2.189 (95% C.I. 1.361-3.521, p = 0.001 times more likely to be non-compliant with the programme.This study is the first to show that regret over the initial CRC screening choice was associated with later non-compliance. Screening participants who expressed regret over their choice should receive additional reminders to improve their programmatic compliance.

  6. Value of surveillance {sup 18}F FDG PET/CT in colorectal cancer:comparison with conventional imaging studies

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Eun Kyoung; Yoo, Ie Ryung; Park, Hye Lim; Choi, Hyun Su; Han, Eun Ji; Kim, Sung Hoon; Chung, Soo Kyo; O, Joo Hyun [The Catholic Univ. of Korea, Seoul (Korea, Republic of)

    2012-09-15

    To assess the value of PET/CT for detecting local or distant recurrence in patients who undergo surgery for colorectal cancer (CRC)and to compare the accuracy of PET/CT to that of conventional imaging studies (CIS). Tumor surveillance PET/CT scans done between March 2005 and December 2009 of disease free patients after surgery with or without adjuvant chemotherapy for CRC were retrospectively studied. CIS (serial enhanced CT from lung base to pelvis and plain chest radiograph)were performed within 1 month of PET/CT. We excluded patients with distant metastasis on initial staging, a known recurrent tumor, and a lack of follow up imaging. The final diagnosis was based on at least 6 months of follow up with colonoscopy, biopsy, and serial imaging studies in combination with carcinoembryonic antigen levels. A total of 262 PET/CT scans of 245 patients were included. Local and distant recurrences were detected in 27 cases (10.3%). On case based analysis, the overall sensitivity, specificity, and accuracy were 100, 97.0, and 97.3% for PET/CT and 85.1, 97.0, and 95.8% for CIS, respectively. On lesion based analysis, PET/CT detected more lesions compared to CIS in local recurrence and lung metastasis. PET/CT and CIS detected the same number of lesions in abdominal lymph nodes, hepatic metastasis, and peritoneal carcinomatosis. PET/CT detected two more metachronous tumors than did CIS in the lung and thyroid gland. PET/CT detected more recurrences in patients who underwent surgery for CRC than did CIS and had the additional advantage of evaluating the entire body during a single scan.

  7. How to study optimal timing of PET/CT for monitoring of cancer treatment

    DEFF Research Database (Denmark)

    Vach, Werner; Høilund-Carlsen, Poul Flemming; Fischer, Barbara Malene Bjerregaard

    2011-01-01

    Purpose: The use of PET/CT for monitoring treatment response in cancer patients after chemo- or radiotherapy is a very promising approach to optimize cancer treatment. However, the timing of the PET/CT-based evaluation of reduction in viable tumor tissue is a crucial question. We investigated how...... to plan and analyze studies to optimize this timing. Methods: General considerations about studying the optimal timing are given and four fundamental steps are illustrated using data from a published study. Results: The optimal timing should be examined by optimizing the schedule with respect...... to predicting the overall individual time course we can observe in the case of dense measurements. The optimal timing needs not to and should not be studied by optimizing the association with the prognosis of the patient. Conclusions: The optimal timing should be examined in specific ‘schedule optimizing...

  8. Screening for periodontal disease in research dogs - a methodology study

    DEFF Research Database (Denmark)

    Kortegaard, Hanne E; Eriksen, Thomas; Bælum, Vibeke

    2014-01-01

    BackgroundIt has been shown that the prevalence of both clinical attachment loss (CAL) >1 mm and pocket probing depth (PPD) >4 mm is relatively high even in younger dogs, but also that only a minority of the dogs have such clinical signs of periodontal disease (PD) in more than a few teeth. Hence...... is the central variable in assessing PD extent and severity while PPD is the central variable used in treatment planning which make these two variables obvious in a screening protocol with the dual aim of disease identification and treatment planning. The main purpose of the present study in 98 laboratory Beagle.......2% of all teeth positive for CAL ¿1mm. The results presented here only pertain to the present study population.ConclusionsThis screening protocol is suitable for examination of larger groups of laboratory Beagle dogs for PD and our findings indicate that diseased dogs are identified with a high degree...

  9. Prevalence of Vertebral Compression Fractures on Routine CT Scans According to L1 Trabecular Attenuation: Determining Relevant Thresholds for Opportunistic Osteoporosis Screening.

    Science.gov (United States)

    Graffy, Peter M; Lee, Scott J; Ziemlewicz, Timothy J; Pickhardt, Perry J

    2017-09-01

    Radiologists interpreting body CT scans may be the first to identify osteoporosis and associated vertebral fractures. This study correlates L1 trabecular attenuation measurements with prevalent vertebral body fractures in older adults undergoing routine CT. Mean L1 trabecular attenuation was measured at thoracoabdominal CT in 1966 consecutive adults (983 men and 983 women) 65 years and older (mean age, 74.1 ± 6.6 [SD] years). Sagittal reconstructions and lateral scouts were analyzed for moderate or severe thoracolumbar vertebral compression fractures according to the Genant semiquantitative assessment method. The diagnostic performance of L1 attenuation for the evaluation of prevalent vertebral fractures was assessed, including ROC curve analysis. A total of 162 (8.2%) individuals (mean age, 78.3 years; 66 men, 96 women) had at least one moderate or severe vertebral fracture. The mean L1 attenuation was 70.2 HU among patients with a prevalent fracture, whereas it was 132.3 HU among patients without fracture (p < 0.001). The prevalence of moderate or severe vertebral compression fractures was 32.5% when L1 attenuation was ≤ 90 HU. Prevalence increased to 49.2% with L1 attenuation of ≤ 50 HU. ROC curve analysis determined an optimal threshold of 90 HU (sensitivity = 86.9%, specificity = 83.9%), with a corresponding AUC of 0.895. The odds ratio of having a moderate or severe vertebral compression fracture was 31.9 for L1 attenuation ≤ 90 HU (95% CI, 20.2-50.5; p < 0.001). Patients with moderate or severe vertebral compression fractures have significantly lower L1 attenuation values than patients who do not. L1 attenuation ≤ 90 HU may represent an optimal threshold for determining risk for osteoporotic vertebral fractures.

  10. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... limitations of CT Scanning of the Head? What is CT Scanning of the Head? Computed tomography, more ... the body being studied. top of page How is the procedure performed? The technologist begins by positioning ...

  11. Computed Tomography (CT) -- Sinuses

    Medline Plus

    Full Text Available ... the limitations of CT of the Sinuses? What is CT (Computed Tomography) of the Sinuses? Computed tomography, ... the body being studied. top of page How is the procedure performed? The technologist begins by positioning ...

  12. CT Grading of Otosclerosis

    National Research Council Canada - National Science Library

    Lee, T.C; Aviv, R.I; Chen, J.M; Nedzelski, J.M; Fox, A.J; Symons, S.P

    2009-01-01

    ...: The CT grading system for otosclerosis was proposed by Symons and Fanning in 2005. The purpose of this study was to determine if this CT grading system has high interobserver and intraobserver agreement...

  13. Abdominal and Pelvic CT

    Medline Plus

    Full Text Available ... page How should I prepare for the CT scan? You should wear comfortable, loose-fitting clothing to ... studied. top of page How is the CT scan performed? The technologist begins by positioning you on ...

  14. Computed Tomography (CT) -- Sinuses

    Medline Plus

    Full Text Available ... benefits vs. risks? Benefits A CT scan is one of the safest means of studying the sinuses. ... CT scanning provides very detailed images of many types of tissue as well as the lungs, bones, ...

  15. Dual-energy compared to single-energy CT in pediatric imaging: a phantom study for DECT clinical guidance

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Xiaowei; Servaes, Sabah; Darge, Kassa [The Children' s Hospital of Philadelphia, Department of Radiology, Philadelphia, PA (United States); University of Pennsylvania, The Perelman School of Medicine, Philadelphia, PA (United States); McCullough, William P. [University of Virginia Health System, Department of Radiology and Medical Imaging, Charlottesville, VA (United States); Mecca, Patricia [The Children' s Hospital of Philadelphia, Department of Radiology, Philadelphia, PA (United States)

    2016-11-15

    Dual-energy CT technology is available on scanners from several vendors and offers significant advantages over classic single-energy CT technology in multiple clinical applications. Many studies have detailed dual-energy CT applications in adults and several have evaluated the relative radiation dose performance of dual-energy CT in adult imaging. However, little has been published on dual-energy CT imaging in the pediatric population, and the relative dose performance of dual-energy CT imaging in the pediatric population is not well described. When evaluating dual-energy CT technology for implementation into a routine clinical pediatric imaging practice, the radiation dose implications must be considered, and when comparing relative CT dose performance, image quality must also be evaluated. Therefore the purpose of this study is to develop dual-energy CT scan protocols based on our optimized single-energy scan protocols and compare the dose. We scanned the head, chest and abdomen regions of pediatric-size anthropomorphic phantoms with contrast inserts, using our optimized single-energy clinical imaging protocols on a Siemens Flash {sup registered} CT scanner. We then scanned the phantoms in dual-energy mode using matching image-quality reference settings. The effective CT dose index volume (CTDI{sub vol}) of the scans was used as a surrogate for relative dose in comparing the single- and dual-energy scans. Additionally, we evaluated image quality using visual assessment and contrast-to-noise ratio. Dual-energy CT scans of the head and abdomen were dose-neutral for all three phantoms. Dual-energy CT scans of the chest showed a relative dose increase over the single-energy scan for 1- and 5-year-old child-based age-equivalent phantoms, ranging 11-20%. Quantitative analysis of image quality showed no statistically significant difference in image quality between the single-energy and dual-energy scans. There was no clinically significant difference in image quality by

  16. Do Foley catheters adequately drain the bladder? Evidence from CT imaging studies

    Energy Technology Data Exchange (ETDEWEB)

    Avulova, Svetlana; Li, Valery J.; Khusid, Johnathan A. [Department of Urology, SUNY Downstate College of Medicine, Brooklyn, NY (United States); Choi, Woo S. [Radiology, SUNY Downstate College of Medicine, Brooklyn, NY (United States); Weiss, Jeffrey P., E-mail: johnathan.khusid@downstate.edu [Department of Urology, Weill Cornell Medical College, New York, NY (United States)

    2015-05-15

    Introduction: The Foley catheter has been widely assumed to be an effective means of draining the bladder. However, recent studies have brought into question its efficacy. The objective of our study is to further assess the adequacy of Foley catheter for complete drainage of the bladder. Materials and Methods: Consecutive catheterized patients were identified from a retrospective review of contrast enhanced and non-contrast enhanced computed tomographic (CT) abdomen and pelvis studies completed from 7/1/2011-6/30/2012. Residual urine volume (RUV) was measured using 5mm axial CT sections as follows: The length (L) and width (W) of the bladder in the section with the greatest cross sectional area was combined with bladder height (H) as determined by multiplanar reformatted images in order to calculate RUV by applying the formula for the volume (V) of a sphere in a cube:V=(π/6)⁎L⁎W⁎H). Results: RUVs of 167 (mean age 67) consecutively catheterized men (n=72) and women (n=95) identified by CT abdomen and pelvis studies were calculated. The mean RUV was 13.2 mL (range: 0.0 mL-859.1 mL, standard deviation: 75.9 mL, margin of error at 95% confidence:11.6 mL). Four (2.4%) catheterized patients had RUVs of >50 mL, two of whom had an improperly placed catheter tip noted on their CT-reports. Conclusions: Previous studies have shown that up to 43% of catheterized patients had a RUV greater than 50 mL, suggesting inadequacy of bladder drainage via the Foley catheter. Our study indicated that the vast majority of patients with Foley catheters (97.6%), had adequately drained bladders with volumes of <50 mL. (author)

  17. Study on the application value of CT perfusion imaging in patients with hepatic carcinoma

    Institute of Scientific and Technical Information of China (English)

    Yu-Gang Zhou; Cheng-Zhou Yu; Xi-Qun Liu

    2016-01-01

    Objective:To research and discuss the application value of CT perfusion imaging in patients with hepatic carcinoma.Methods: A total of 47 patients with hepatic carcinoma in our hospital from Januarey 2014 to August 2015 were selected as study group; meanwhile the contemporaneous 47 patients with benign liver disease were selected as control group. Then the CT perfusion imaging parameters of hepatic carcinoma patients in control group and study group, and hepatic carcinoma patients with different types and stages in study group were respectively compared and the relationship between above indexes and hepatic carcinoma were analyzed by Logistic Analysis.Results:The BF, BV, HAI, MTT, PS and HAP levels in study group were all higher than that in control group, while the PVP level was lower than that in control group, and the detection results between hepatic carcinoma patients with different stages in study group also had obvious difference, statistical results of patients with higher stages were all worse than those of patients with lower stages, but the above statistical results among hepatic carcinoma patients with different types had no obvious difference, and the above detection indexes all had close relations with hepatic carcinoma by Logistic Analysis. Conclusion:The application value of CT perfusion imaging in patients with hepatic carcinoma was high, and it had active reaction value for the lesion blood flow of patients with hepatic carcinoma, and it also had high clinical value for the stages of disease.

  18. CT SCAN FINDINGS IN PATIENTS WITH SEIZURES IN NOTHERN CHHATTISGARH : A RETROSPECTIVE STUDY

    Directory of Open Access Journals (Sweden)

    Archana

    2015-09-01

    Full Text Available A five years study of CT scan findings in seizure patients is carried out to know the different etiology. Seizure is a finite event of altered cerebral function because of excessive and abnormal electrical discharges of the brain cells. Epilepsy is a chronic condition predisposing a person to recurrent seizures. This study is designed to establish usefulness of CT in defining the etiology of seizures in various age groups in people of Northern Chhattisgarh. This is a retrospective hospital - based study conducted in Radio - diagnosis Department of Chhattisgarh Institute of Medical Sciences, Bilaspur, Chhattisgarh. The study was carried out over a 5 year period. Hospital admissions with history of seizures are very common. Almost 3 - 9% p er 1000 population of total hospital emergencies is seizure cases. Epilepsy is an important health problem in developing countries, where its prevalence can be up to 57 per 1000 population. This study has high prevalence of seizures in First, second, third and fourth decades with decreasing pattern with increasing age. Prevalence in first decade is low as compare to second and third decades. Tuberculoma (9.39% and Neurocysticercosis (3.60% has highest prevalence in partial seizures followed by Focal Cereb ral Edema (6.22% whereas Diffuse Cerebral edema (4.91% seen with Generalised Seizures Cerebral infarct has equally seen in both types of seizures. Brain tumour presented mostly with Generalised seizure (2.07% than in partial seizures (0.98% . Other abno rmal findings like Cerebral calcifications, Diffuse cortical atrophy, Focal cortical atrophy, Sub Arachnoid hemorrhage, Intracerebral Hemorrhage, Hypoxic Ischemic Encephalopathy, Hydrocephalus and few rare diseases like Fahr disease and Tuberous sclerosis have also seen in CT scan in seizure patients. CT scan is valuable in making a diagnosis particularly in Indian subcontinent, where infective causes in form of space occupying lesions and infections are most

  19. Normal SUV values measured from NaF18- PET/CT bone scan studies.

    Directory of Open Access Journals (Sweden)

    Aung Zaw Win

    Full Text Available Cancer and metabolic bone diseases can alter the SUV. SUV values have never been measured from healthy skeletons in NaF18-PET/CT bone scans. The primary aim of this study was to measure the SUV values from normal skeletons in NaF18-PET/CT bone scans.A retrospective study was carried out involving NaF18- PET/CT bone scans that were done at our institution between January 2010 to May 2012. Our excluding criteria was patients with abnormal real function and patients with past history of cancer and metabolic bone diseases including but not limited to osteoporosis, osteopenia and Paget's disease. Eleven studies met all the criteria.The average normal SUVmax values from 11 patients were: cervical vertebrae 6.84 (range 4.38-8.64, thoracic vertebrae 7.36 (range 6.99-7.66, lumbar vertebrae 7.27 (range 7.04-7.72, femoral head 2.22 (range 1.1-4.3, humeral head 1.82 (range 1.2-2.9, mid sternum 5.51 (range 2.6-8.1, parietal bone 1.71 (range 1.3-2.4.According to our study, various skeletal sites have different normal SUV values. SUV values can be different between the normal bones and bones with tumor or metabolic bone disease. SUV can be used to quantify NaF-18 PET/CT studies. If the SUV values of the normal skeleton are known, they can be used in the characterization of bone lesions and in the assessment of treatment response to bone diseases.

  20. A dual tracer (68)Ga-DOTANOC PET/CT and (18)F-FDG PET/CT pilot study for detection of cardiac sarcoidosis.

    Science.gov (United States)

    Gormsen, Lars C; Haraldsen, Ate; Kramer, Stine; Dias, Andre H; Kim, Won Yong; Borghammer, Per

    2016-12-01

    Cardiac sarcoidosis (CS) is a potentially fatal condition lacking a single test with acceptable diagnostic accuracy. (18)F-FDG PET/CT has emerged as a promising imaging modality, but is challenged by physiological myocardial glucose uptake. An alternative tracer, (68)Ga-DOTANOC, binds to somatostatin receptors on inflammatory cells in sarcoid granulomas. We therefore aimed to conduct a proof-of-concept study using (68)Ga-DOTANOC to diagnose CS. In addition, we compared diagnostic accuracy and inter-observer variability of (68)Ga-DOTANOC vs. (18)F-FDG PET/CT. Nineteen patients (seven female) with suspected CS were prospectively recruited and dual tracer scanned within 7 days. PET images were reviewed by four expert readers for signs of CS and compared to the reference standard (Japanese ministry of Health and Welfare CS criteria). CS was diagnosed in 3/19 patients. By consensus, 11/19 (18)F-FDG scans and 0/19 (68)Ga-DOTANOC scans were rated as inconclusive. The sensitivity of (18)F-FDG PET for diagnosing CS was 33 %, specificity was 88 %, PPV was 33 %, NPV was 88 %, and diagnostic accuracy was 79 %. For (68)Ga-DOTANOC, accuracy was 100 %. Inter-observer agreement was poor for (18)F-FDG PET (Fleiss' combined kappa 0.27, NS) and significantly better for (68)Ga-DOTANOC (Fleiss' combined kappa 0.46, p = 0.001). Despite prolonged pre-scan fasting, a large proportion of (18)F-FDG PET/CT images were rated as inconclusive, resulting in low agreement among reviewers and correspondingly poor diagnostic accuracy. By contrast, (68)Ga-DOTANOC PET/CT had excellent diagnostic accuracy with the caveat that inter-observer variability was still significant. Nevertheless, (68)Ga-DOTANOC PET/CT looks very promising as an alternative CS PET tracer. Current Controlled Trials NCT01729169 .

  1. Thoracic CT

    Science.gov (United States)

    ... lungs; CT scan - chest Images CT scan Thyroid cancer - CT scan Pulmonary nodule, solitary - CT scan Lung mass, right upper ... Chest Injuries and Disorders CT Scans Emphysema Lung Cancer Lung Diseases Pleural Disorders Pneumonia Pulmonary Embolism Tuberculosis Browse the Encyclopedia A.D.A. ...

  2. Contrast study on CT and BA in cerebral hemorrhage due to hypertension%CONTRAST STUDY ON CT AND BA IN CEREBRAL HEMORRHAGE DUE TO HYPERTENSION

    Institute of Scientific and Technical Information of China (English)

    Mingshun Liu; Guoqiu Wang; Po Ma

    2007-01-01

    Objectives:To explore contrast application on CT and BA in cerebral hemorrhage due to hypertension. Methods: CT and BA were examined in 106 patients with cerebral hemorrhage due to hypertension. Results:The different changes of CT and BA were showed in 106 patients with cerebral hemorrhage due to hypertension. Conclusions: There were separately different advantage and shortcoming in CT and BA in diagnosis of cerebral hemorrhage due to hypertension. The value of clinical application of BA was important in cerebral hemorrhage due to hypertension.

  3. The potential harms of primary human papillomavirus screening in over-screened women: a microsimulation study

    NARCIS (Netherlands)

    S.K. Naber (Steffie); I.M.C.M. de Kok (Inge); S.M. Matthijsse (Suzette); M. van Ballegooijen (Marjolein)

    2016-01-01

    textabstractBackground: It is well acknowledged that HPV testing should not be performed at young age and at short intervals. Cytological screening practices have shown that over-screening, i.e., from a younger age and at shorter intervals than recommended, is hard to avoid. We quantified the conseq

  4. Assessment of small bowel Crohn disease: noninvasive peroral CT enterography compared with other imaging methods and endoscopy--feasibility study.

    Science.gov (United States)

    Wold, Peter B; Fletcher, Joel G; Johnson, C Daniel; Sandborn, William J

    2003-10-01

    A feasibility study was conducted to evaluate two biphasic computed tomographic (CT) enterography protocols, a noninvasive CT technique with water administered perorally and CT enteroclysis with methylcellulose administered through a nasojejunal tube, in 23 patients known or suspected to have Crohn disease. Results were compared with the results of fluoroscopic small bowel examination and terminal ileoscopy for the detection of active Crohn disease in the terminal ileum. Luminal distention did not differ significantly between the two CT protocols. Arterial phase imaging was noncontributory in 22 of 23 cases. The noninvasive peroral water CT enterography protocol had similar accuracy (12 of 15 cases, 80%) for enabling the detection of active Crohn disease in comparison with CT enteroclysis with nasojejunal tube (seven of eight, 88%) and fluoroscopic small bowel examination (17 of 23, 74%). No fistulas were missed with use of either CT technique. The authors conclude that noninvasive peroral portal venous phase CT enterography with use of water is an accurate and feasible technique for detecting active small bowel inflammation in patients with Crohn disease.

  5. PET/CT-guided treatment planning for paediatric cancer patients: a simulation study of proton and conventional photon therapy

    DEFF Research Database (Denmark)

    Kornerup, Josefine S.; Brodin, N. P.; Bjork-Eriksson, T.;

    2015-01-01

    OBJECTIVE: To investigate the impact of including fluorine-18 fludeoxyglucose ((18)F-FDG) positron emission tomography (PET) scanning in the planning of paediatric radiotherapy (RT). METHODS: Target volumes were first delineated without and subsequently re-delineated with access to (18)F-FDG PET......) and estimated risk of secondary cancer (SC). RESULTS: Considerable deviations between CT- and PET/CT-guided target volumes were seen in 3 out of the 11 patients studied. However, averaging over the whole cohort, CT or PET/CT guidance introduced no significant difference in the shape or size of the target...... volumes, target dose coverage, irradiated volumes, estimated NTCP or SC risk, neither for IMPT nor 3DCRT. CONCLUSION: Our results imply that the inclusion of PET/CT scans in the RT planning process could have considerable impact for individual patients. There were no general trends of increasing...

  6. Assessing nodule detection on lung cancer screening CT: the effects of tube current modulation and model observer selection on detectability maps

    Science.gov (United States)

    Hoffman, J. M.; Noo, F.; McMillan, K.; Young, S.; McNitt-Gray, M.

    2016-03-01

    Lung cancer screening using low dose CT has been shown to reduce lung cancer related mortality and been approved for widespread use in the US. These scans keep radiation doses low while maximizing the detection of suspicious lung lesions. Tube current modulation (TCM) is one technique used to optimize dose, however limited work has been done to assess TCM's effect on detection tasks. In this work the effect of TCM on detection is investigated throughout the lung utilizing several different model observers (MO). 131 lung nodules were simulated at 1mm intervals in each lung of the XCAT phantom. A Sensation 64 TCM profile was generated for the XCAT phantom and 2500 noise realizations were created using both TCM and a fixed TC. All nodules and noise realizations were reconstructed for a total of 262 (left and right lungs) nodule reconstructions and 10 000 XCAT lung reconstructions. Single-slice Hotelling (HO) and channelized Hotelling (CHO) observers, as well as a multislice CHO were used to assess area-under-the-curve (AUC) as a function of nodule location in both the fixed TC and TCM cases. As expected with fixed TC, nodule detectability was lowest through the shoulders and leveled off below mid-lung; with TCM, detectability was unexpectedly highest through the shoulders, dropping sharply near the mid-lung and then increasing into the abdomen. Trends were the same for all model observers. These results suggest that TCM could be further optimized for detection and that detectability maps present exciting new opportunities for TCM optimization on a patient-specific level.

  7. The frequency of intracranial arterial fenestrations: A study with 64-detector CT-angiography

    Energy Technology Data Exchange (ETDEWEB)

    Bayrak, Aylin Hasanefendioglu, E-mail: aylin_has@yahoo.com [Dicle University, School of Medicine, Radiology Department, Diyarbakir (Turkey); Senturk, Senem, E-mail: ssenturk@dicle.edu.tr [Dicle University, School of Medicine, Radiology Department, Diyarbakir (Turkey); Akay, Hatice Ozturkmen, E-mail: hozturkmen@gmail.com [Veni Vidi Hospital, Diyarbakir (Turkey); Ozmen, Cihan Akgul, E-mail: cihanakgul@dicle.edu.tr [Dicle University, School of Medicine, Radiology Department, Diyarbakir (Turkey); Bukte, Yasar, E-mail: ybukte@dicle.edu.tr [Dicle University, School of Medicine, Radiology Department, Diyarbakir (Turkey); Nazaroglu, Hasan, E-mail: hnazarog@dicle.edu.tr [Dicle University, School of Medicine, Radiology Department, Diyarbakir (Turkey)

    2011-03-15

    Fenestration is a vascular variation that begins with a common origin, then splits into two parallel luminal channels and rejoins distally. Potential association between anomalies of cerebral circulation and increased occurrence of aneurysm makes intracranial arterial fenestrations important. The planning of intracranial arterial interventions may be complicated if a fenestration occurs proximal to the site of intended treatment. This study is planned to determine the frequency of fenestrations on CT angiography and to search whether there is relationship between aneurysms and fenestrations. CT angiographies of 395 consecutive patients, performed by 64-detector CT, were retrospectively reviewed for aneurysms and fenestrations. Overall fenestration frequency, fenestration frequency in patients with and without aneurysm, and aneurysm frequency in patients with and without fenestration were searched. Demographic characteristics of patients were also compared. Overall fenestration frequency was 12.9%. Vertebrobasilar system (5.56%) and anterior communicating region (5.32%) were the two most frequent sites of fenestration. The rate of fenestrations was not significantly different between patients who had and did not have aneurysms. Mean age was significantly higher, and females were predominant in patients with aneurysms. However our results did not show significant difference in age and sex of patients with fenestrations. The frequency of fenestrations in this study is higher than in previously published radiological studies, suggesting that fenestrations are relatively common. There is no significant relationship between the frequency of aneurysms and fenestrations.

  8. Quantitative study on crack of meso-damage and fracture concrete based on CT technique

    Indian Academy of Sciences (India)

    Wei Tian; Faning Dang; Yongli Xie

    2015-02-01

    The meso-mechanics experiment of concrete specimen is carried out by means of CT technology, the whole degradation deformation process of meso-cracks generation, propagation, coalescence and failure is obtained under uniaxial compression condition. Based on CT image of concrete meso-damage evolution, the recognition and extraction of meso-cracks are realized by means of the digital imageprocessing (DIP) technique, and the basic geometrical characteristics of meso-crack patterns are statistically analysed from length, width and area. The quantitative analysis of the meso-fracture process of concrete materials is performed. The results demonstrate that the quantitative analysis of the internal meso-crack of concrete can be taken as a quantitative index to reflect the damage and fracture process thereby the meso-fracture mechanism of concrete material is thoroughly investigated. So it has brought forth some new ideas to the study of damage evolution law of concrete under uniaxial compression condition.

  9. From 3D to 4D: Integration of temporal information into CT angiography studies.

    Science.gov (United States)

    Haubenreisser, Holger; Bigdeli, Amir; Meyer, Mathias; Kremer, Thomas; Riester, Thomas; Kneser, Ulrich; Schoenberg, Stefan O; Henzler, Thomas

    2015-12-01

    CT angiography is the current clinical standard for the imaging many vascular illnesses. This is traditionally done with a single arterial contrast phase. However, advances in CT technology allow for a dynamic acquisition of the contrast bolus, thus adding temporal information to the examination. The aim of this article is to highlight the clinical possibilities of dynamic CTA using 2 examples. The accuracy of the detection and quantification of stenosis in patients with peripheral arterial occlusive disease, especially in stadium III and IV, is significantly improved when performing dynamic CTA examinations. The post-interventional follow-up of examinations of EVAR benefit from dynamic information, allowing for a higher sensitivity and specificity, as well as allowing more accurate classification of potential endoleaks. The described radiation dose for these dynamic examinations is low, but this can be further optimized by using lower tube voltages. There are a multitude of applications for dynamic CTA that need to be further explored in future studies.

  10. Clinical utility of FDG PET/CT in acute complicated pyelonephritis-results from an observational study.

    Science.gov (United States)

    Wan, Chih-Hsing; Tseng, Jing-Ren; Lee, Ming-Hsun; Yang, Lan-Yan; Yen, Tzu-Chen

    2017-09-26

    Acute complicated pyelonephritis (ACP) is an upper urinary tract infection associated with coexisting urinary tract abnormalities or medical conditions that could predispose to serious outcomes or treatment failures. Although CT and magnetic resonance imaging (MRI) are frequently used in patients with ACP, the clinical value of (18)F-fluorodeoxyglucose positron emission tomography and computed tomography (FDG PET/CT) has not been systematically investigated. This single-center retrospective study was designed to evaluate the potential usefulness of FDG PET/CT in patients with ACP. Thirty-one adult patients with ACP who underwent FDG PET/CT were examined. FDG PET/CT imaging characteristics, including tracer uptake patterns, kidney volumes, and extrarenal imaging findings, were reviewed in combination with clinical data and conventional imaging results. Of the 31 patients, 19 (61%) showed focal FDG uptake. The remaining 12 study participants showed a diffuse FDG uptake pattern. After volumetric approximation, the affected kidneys were found to be significantly enlarged. Patients who showed a focal uptake pattern had a higher frequency of abscess formation requiring drainage. ACP patients showing diffuse tracer uptake patterns had a more benign clinical course. Seven patients had suspected extrarenal coinfections, and FDG PET/CT successfully confirmed the clinical suspicion in five cases. FDG PET/CT was as sensitive as CT in identifying the six patients (19%) who developed abscesses. Notably, FDG PET/CT findings caused a modification to the initial antibiotic regimen in nine patients (29%). FDG PET/CT may be clinically useful in the assessment of patients with ACP who have a progressive disease course.

  11. Study of dosimetry CT in Skull for pediatric patients; Estudio de dosimetria TC en craneo para pacientes pediatricos

    Energy Technology Data Exchange (ETDEWEB)

    Ramos Amores, D.; Serna Berna, A.; Mata Colodro, F.; Puchades Puchades, V.

    2013-07-01

    The dose that receiving the patients in CT studies is the highest that can be received in a study of Radiology. If patients are children and we do studies with the same parameters as adults, they will receive a higher dose of radiation. This work seeks to expose the result of a dosimetric study on CT for children aged 0-15, carried out at the Hospital General Universitario de Santa Lucia in Cartagena during the year 2012. (Author)

  12. Zagreb Amblyopia Preschool Screening Study: near and distance visual acuity testing increase the diagnostic accuracy of screening for amblyopia

    OpenAIRE

    Bušić, Mladen; Bjeloš, Mirjana; Petrovečki, Mladen; Kuzmanović Elabjer, Biljana; Bosnar, Damir; Ramić, Senad; Miletić, Daliborka; Andrijašević, Lidija; Kondža Krstonijević, Edita; Jakovljević, Vid; Bišćan Tvrdi, Ana; Predović, Jurica; Kokot, Antonio; Bišćan, Filip; Kovačević Ljubić, Mirna

    2016-01-01

    Aim To present and evaluate a new screening protocol for amblyopia in preschool children. Methods Zagreb Amblyopia Preschool Screening (ZAPS) study protocol performed screening for amblyopia by near and distance visual acuity (VA) testing of 15 648 children aged 48-54 months attending kindergartens in the City of Zagreb County between September 2011 and June 2014 using Lea Symbols in lines test. If VA in either eye was >0.1 logMAR, the child was re-tested, if failed at re-test, the child was ...

  13. FDG PET/CT in bone sarcoidosis.

    Science.gov (United States)

    Grozdic Milojevic, Isidora; Sobic-Saranovic, Dragana; Videnovic-Ivanov, Jelica; Saranovic, Djordjije; Odalovic, Strahinja; Artiko, Vera

    2016-03-29

    Bone sarcoidosis is rare manifestation of disease usually accompanied with pulmonary involvement. Until today, exact prevalence of bone sarcoidosis is not known, since reported prevalence varies widely depending on the studied population and the used diagnostic techniques. To determine the prevalence of bone involvement and distribution pattern in active chronic sarcoidosis by using FDG PET/CT. Between January 2010 and December 2011, 98 patients with chronic sarcoidosis and presence of prolonged symptoms or other findings suggestive of active disease were referred to FDG PET/CT examination. Active disease was found in 82 patients, and they all were screened for presence of bone sarcoidosis on FDG PET/CT. All patients also underwent MDCT and assessment of serum ACE level. Bone sarcoidosis was present in 18/82 patients with active sarcoidosis. FDG uptake in bones was focal in 8 (44.4%), diffuse in 6 (33.3%) and both diffuse and focal in 4 (22.2%) patients. CT indicated bone abnormalities only in 5% patients. Osseous involvement was present in: pelvis (61.1%), vertebrae (44.4%), ribs (27.8%) and bone marrow (16.7%). Some patients had two or more locations of disease. Follow-up FDG PET/CT showed normal findings in two patients, same localization of active disease in four patients and progression of disease in one. In patients with active chronic sarcoidosis 22% of patients had osseous abnormalities on FDG PET/CT that mostly were not detected on CT.

  14. Pilot Study to Confirm that Fat and Liver can be Distinguished by Spectroscopic Tissue Response on a Medipix-All-Resolution System-CT (MARS-CT)

    Science.gov (United States)

    Berg, Kyra B.; Carr, James M.; Clark, Michael J.; Cook, Nick J.; Anderson, Nigel G.; Scott, Nicola J.; Butler, Alexandra P.; Butler, Philip H.; Butler, Anthony P.

    2009-07-01

    NAFLD, liver component of the "metabolic" syndrome, has become the most common liver disease in western nations. Non-invasive imaging techniques exist, but have limitations, especially in detection and quantification of mild to moderate fatty liver. In this pilot study, we produced attenuation curves from biomedical-quality projection images of liver and fat using the MARS spectroscopic-CT scanner. Difficulties obtaining attenuation spectra after reconstruction demonstrated that standard reconstruction programs do not preserve spectral information.

  15. Automated screening versus manual screening: a comparison of the ThinPrep imaging system and manual screening in a time study.

    Science.gov (United States)

    Schledermann, Doris; Hyldebrandt, Tina; Ejersbo, Dorthe; Hoelund, Berit

    2007-06-01

    The ThinPrep Imaging System (TIS) is an automated system that assists cytotechnologists in the primary screening of ThinPrep liquid based cervical samples. Between June 1, 2004, and April 1, 2005, four experienced cytotechnologists participated in the study in which the duration of the screening procedure was timed for each of the 11,354 slides included. In every slide 22 fields of view were reviewed, and the samples that contained potentially abnormal cells were fully screened. The screening time was reduced by 42% (mean) (p < 0.001). By manual rescreening of the negative TIS samples, abnormal cells were found in 10 samples (false negative rate 0.14%). In every case the abnormal cells had been identified by the scanner, but misinterpreted by the cytotechnologist. These findings stressed the importance of carefulness in the interpretation of the marked fields and beyond that helped the cytotechnologists and pathologists to have more confidence in the automated system.

  16. Sensitivity and accuracy of volumetry of pulmonary nodules on low-dose 16- and 64-row multi-detector CT: an anthropomorphic phantom study

    Energy Technology Data Exchange (ETDEWEB)

    Xie, Xueqian; Zhao, Yingru; Ooijen, Peter M.A. van; Vliegenthart, Rozemarijn [University of Groningen, University Medical Center Groningen, Department of Radiology, EB44, P.O. Box 30.001, Groningen (Netherlands); University of Groningen, University Medical Center Groningen, Center for Medical Imaging-North East Netherlands, Department of Radiology, Groningen (Netherlands); Snijder, Roland A.; Greuter, Marcel J.W. [University of Groningen, University Medical Center Groningen, Department of Radiology, EB44, P.O. Box 30.001, Groningen (Netherlands); Jong, Pim A. de [University Medical Center Utrecht, Department of Radiology, Utrecht (Netherlands); Oudkerk, Matthijs [University of Groningen, University Medical Center Groningen, Center for Medical Imaging-North East Netherlands, Department of Radiology, Groningen (Netherlands); Bock, Geertruida H. de [University of Groningen, University Medical Center Groningen, Department of Epidemiology, Groningen (Netherlands)

    2013-01-15

    To assess the sensitivity of detection and accuracy of volumetry by manual and semi-automated quantification of artificial pulmonary nodules in an anthropomorphic thoracic phantom on low-dose CT. Fifteen artificial spherical nodules (diameter 3, 5, 8, 10 and 12 mm; CT densities -800, -630 and +100 HU) were randomly placed inside an anthropomorphic thoracic phantom. The phantom was examined on 16- and 64-row multidetector CT with a low-dose protocol. Two independent blinded observers screened for pulmonary nodules. Nodule diameter was measured manually, and volume calculated. For solid nodules (+100 HU), diameter and volume were also evaluated by semi-automated software. Differences in observed volumes between the manual and semi-automated method were evaluated by a t-test. Sensitivity was 100 % for all nodules of >5 mm and larger, 60-80 % for solid and 0-20 % for non-solid 3-mm nodules. No false-positive nodules but high inter-observer reliability and inter-technique correlation were found. Volume was underestimated manually by 24.1 {+-} 14.0 % for nodules of any density, and 26.4 {+-} 15.5 % for solid nodules, compared with 7.6 {+-} 8.5 % (P < 0.01) semi-automatically. In an anthropomorphic phantom study, the sensitivity of detection is 100 % for nodules of >5 mm in diameter. Semi-automated volumetry yielded more accurate nodule volumes than manual measurements. (orig.)

  17. The relationship between post-traumatic ossicular injuries and conductive hearing loss: A 3D-CT study.

    Science.gov (United States)

    Maillot, Olivier; Attyé, Arnaud; Boutet, Claire; Boubagra, Kamel; Perolat, Romain; Zanolla, Marion; Grand, Sylvie; Schmerber, Sébastien; Krainik, Alexandre

    2017-09-01

    After a trauma, the conductive ossicular chain may be disrupted by ossicular luxation or fracture. Recent developments in 3D-CT allow a better understanding of ossicular injuries. In this retrospective study, we compared patients with post-traumatic conductive hearing loss (CHL) with those referred without CHL to evaluate the relationship between ossicular injuries and CHL. We also assessed the added value of 3D reconstructions on 2D-CT scan to detect ossicular lesions in patients surgically managed. The CT scans were performed using a 40-section spiral CT scanner in 49 patients with post-traumatic CHL (n=29) and without CHL (n=20). Three radiologists performed independent blind evaluations of 2D-CT and 3D reconstructions to detect ossicular chain injury. We used the t-test to explore differences regarding the number of subjects with ossicular injury in the two groups. We also estimated the diagnostic accuracy and the inter-rater agreement of the 3D-CT reconstructions associated to 2D-CT scan. We identified ossicular abnormality in 14 patients out of 29 and in one patient out of 20 in the CHL and non-CHL groups respectively. There was a significant difference regarding the number of subjects with ossicular lesions between the two groups (P≤0.01). The diagnostic sensitivity of 3D-CT reconstructions associated with 2D-CT ranged from 66% to 100% and the inter-reader agreement ranged from 0.85 to 1, depending of the type of lesion. The relationship between ossicular lesion and the presence of CHL tightly correlated. 3D-CT reconstructions of the temporal bone are useful to assess patients in a post-traumatic context. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  18. Observational Multicenter Study of a Direct-to-CT Protocol for EMS-transported Patients with Suspected Stroke.

    Science.gov (United States)

    Cone, David C; Cooley, Craig; Ferguson, Jeffrey; Harrell, Andrew J; Luk, Jeffrey H; Martin-Gill, Christian; Marquis, Sean W; Pasichow, Scott

    2017-08-25

    In an effort to decrease door-to-needle times for patients with acute ischemic stroke, some hospitals have begun taking stable EMS patients with suspected stroke directly from the ambulance to the CT scanner, then to an emergency department (ED) bed for evaluation. Minimal data exist regarding the potential for time savings with such a protocol. The study hypothesis was that a direct-to-CT protocol would be associated with decreases in both door-to-CT-ordered and door-to-needle times. An observational, multicenter before/after study was conducted of time/process measures at hospitals that have implemented direct-to-CT protocols for patients transported by EMS with suspected stroke. Participating hospitals submitted data on at least the last 50 "EMS stroke alert" patients before the launch of the direct-to-CT protocol, and at least the first 50 patients after. Time elements studied were arrival at the ED, time the head CT was ordered, and time tPA was started. Data were submitted in blinded fashion (patient and hospital identifiers removed); at the time of data analysis, the lead investigator was unaware of which data came from which hospital. Simple descriptive statistics were used, along with the Mann-Whitney test to compare time medians. Seven hospitals contributed data on 1040 patients (529 "before" and 511 "after"); 512 were male, and 627 had final diagnoses of ischemic stroke, of whom 275 received tPA. The median door-to-CT-ordered time for all patients was 7 minutes in the before phase, and 4 minutes after (difference 3 minutes, p = < 0.0001); similarly, the median door-to-CT-started time was 6 minutes "before" and 10 minutes after (p < 0.0001). The median door-to-needle time for all patients given tPA was 42 minutes before, and 44 minutes after (p = 0.78). Four hospitals had modest decreases in door-to-CT-ordered time (of 2, 4, 2, and 5 minutes), and only one hospital had a decrease in door-to-needle time (32 min vs 26 min, p = 0.012). In this sample from

  19. Zagreb Amblyopia Preschool Screening Study: near and distance visual acuity testing increase the diagnostic accuracy of screening for amblyopia.

    Science.gov (United States)

    Bušić, Mladen; Bjeloš, Mirjana; Petrovečki, Mladen; Kuzmanović Elabjer, Biljana; Bosnar, Damir; Ramić, Senad; Miletić, Daliborka; Andrijašević, Lidija; Kondža Krstonijević, Edita; Jakovljević, Vid; Bišćan Tvrdi, Ana; Predović, Jurica; Kokot, Antonio; Bišćan, Filip; Kovačević Ljubić, Mirna; Motušić Aras, Ranka

    2016-02-01

    To present and evaluate a new screening protocol for amblyopia in preschool children. Zagreb Amblyopia Preschool Screening (ZAPS) study protocol performed screening for amblyopia by near and distance visual acuity (VA) testing of 15 648 children aged 48-54 months attending kindergartens in the City of Zagreb County between September 2011 and June 2014 using Lea Symbols in lines test. If VA in either eye was >0.1 logMAR, the child was re-tested, if failed at re-test, the child was referred to comprehensive eye examination at the Eye Clinic. 78.04% of children passed the screening test. Estimated prevalence of amblyopia was 8.08%. Testability, sensitivity, and specificity of the ZAPS study protocol were 99.19%, 100.00%, and 96.68% respectively. The ZAPS study used the most discriminative VA test with optotypes in line as they do not underestimate amblyopia. The estimated prevalence of amblyopia was considerably higher than reported elsewhere. To the best of our knowledge, the ZAPS study protocol reached the highest sensitivity and specificity when evaluating diagnostic accuracy of VA tests for screening. The pass level defined at ≤0.1 logMAR for 4-year-old children, using Lea Symbols in lines missed no amblyopia cases, advocating that both near and distance VA testing should be performed when screening for amblyopia.

  20. Foot CT perfusion in patients with peripheral arterial occlusive disease (PAOD): A feasibility study

    Energy Technology Data Exchange (ETDEWEB)

    Iezzi, R., E-mail: roberto.iezzi@rm.unicatt.it [Department of Bioimaging and Radiological Sciences, Institute of Radiology, “A. Gemelli” Hospital – Catholic University, L.go A Gemelli 8, 00168 Rome (Italy); Santoro, M., E-mail: dott.santoromarco@gmail.com [Department of Bioimaging and Radiological Sciences, Institute of Radiology, “A. Gemelli” Hospital – Catholic University, L.go A Gemelli 8, 00168 Rome (Italy); Dattesi, R., E-mail: robertadattesi@gmail.com [Department of Bioimaging and Radiological Sciences, Institute of Radiology, “A. Gemelli” Hospital – Catholic University, L.go A Gemelli 8, 00168 Rome (Italy); La Torre, M.F. [Department of Bioimaging and Radiological Sciences, Institute of Radiology, “A. Gemelli” Hospital – Catholic University, L.go A Gemelli 8, 00168 Rome (Italy); Tinelli, G., E-mail: tinelli@rm.unicatt.it [Department of Vascular Surgery, “A. Gemelli” Hospital – Catholic University, L.go A Gemelli 8, 00168 Rome (Italy); Snider, F., E-mail: fsnider@rm.unicatt.it [Department of Vascular Surgery, “A. Gemelli” Hospital – Catholic University, L.go A Gemelli 8, 00168 Rome (Italy); Bonomo, L., E-mail: lbonomo@rm.unicatt.it [Department of Bioimaging and Radiological Sciences, Institute of Radiology, “A. Gemelli” Hospital – Catholic University, L.go A Gemelli 8, 00168 Rome (Italy)

    2013-09-15

    Purpose: To prospectively assess the technical feasibility and reproducibility of quantitative foot perfusion multidetector-row computed tomography (MDCT) in patients with peripheral occlusive artery disease (PAOD) and to evaluate perfusion parameters changes after endovascular treatment. Materials and methods: Institutional review board approval and informed patient consent were obtained. 10 patients older than 65 years (mean 74.1 years, range 66–95 years) with PAOD and who were referred to our department for single-limb endovascular treatment were enrolled prospectively. All patients underwent foot CT perfusion examinations before and within 72 h after endovascular treatment. A 64-row CT lightspeed VCT scanner (GE Medical Systems) was used with acquisition of eight contiguous 5-mm reconstructed sections (60-s acquisition time; 40 mL Iomeprol 400 mgI/mL, @4 mL/s). Data were analyzed by two blinded readers using commercially available software to calculate perfusion parameters. Inter-observer and intra-observer agreement of perfusion CT analysis was assessed using Bland–Altman analyses and intra-class correlation coefficient (ICC). Changes in perfusion parameters after endovascular treatment were assessed using Wilcoxon's test. Results: Good inter-observer and intra-observer agreement was obtained in all patients. Good agreement was obtained for perfusion parameters for the untreated foot and in repeated studies. By comparing perfusion parameters in the treated foot, a significantly shorter mean transit time (MTT) was obtained. Conclusions: Foot CT perfusion is a feasible and reproducible technique. A significant decrease of MTT between pre- and post-revascularization suggests improved flow in the below-the-knee arteries.

  1. Radiation exposure from pediatric head CT: a bi-institutional study

    Energy Technology Data Exchange (ETDEWEB)

    King, Mary A. [University of Washington, Department of Pediatrics, Harborview Medical Center, Seattle, WA (United States); Seattle Children' s Hospital, Seattle, WA (United States); Kanal, Kalpana M.; Relyea-Chew, Annemarie [University of Washington, Department of Radiology, Harborview Medical Center, Seattle, WA (United States); Bittles, Mark [Vanderbilt Children' s Hospital, Department of Radiology, Nashville, TN (United States); Vavilala, Monica S. [University of Washington, Departments of Anesthesiology and Pediatrics, Harborview Medical Center, 325 Ninth Avenue, Box 359724, Seattle, WA (United States); Hollingworth, William [University of Bristol, Department of Social Medicine, Bristol (United Kingdom)

    2009-10-15

    Medical radiation from CT should be kept as low as reasonably achievable (ALARA), particularly in young patients. To examine radiation dose from head CT in children in a trauma center (TC) and a regional children's hospital (RCH). A random sample of 240 children (0-3, 4-9, 10-14 years of age) from the TC were compared with a similar cohort from the RCH. All children had undergone at least one head CT scan without contrast enhancement; data from PACS and Department of Radiology Information System were used to estimate normalized effective dose (ED). Lifetime attributable risk of cancer incidence was estimated using the Biologic Effects of Ionizing Radiation (BEIR) VII report. The mean normalized ED was significantly higher in the youngest children at the TC (2.74 mSv in those aged 0-3 years vs. 2.23 mSv in those aged 10-14 years; P<0.001) and at the RCH (2.44 mSv in those aged 0-3 years vs. 1.71 mSv in those aged 10-14 years; P<0.001). Each decreasing year of age was independently associated with a 0.06 mSv higher mean normalized ED (P<0.001). After adjusting for the age difference between the institutions, the mean normalized ED was 0.44 mSv lower at the RCH than at the TC across all ages (95% CI 0.31-0.58, P<0.001). A higher lifetime attributable risk of cancer was associated with younger age. The radiation dose from head CT in children as defined by the normalized ED was highest in the youngest children and varied significantly between institutions in this bi-institutional study. (orig.)

  2. Evaluation of the image quality of chest CT scans: a phantom study

    Energy Technology Data Exchange (ETDEWEB)

    Martins N, P. I.; Prata M, A., E-mail: priscillainglid@gmail.com [Centro Federal de Educacao Tecnologica de Minas Gerais, Centro de Engenharia Biomedica, Av. Amazonas 5253, 30421-169 Nova Suica, Belo Horizonte, Minas Gerais (Brazil)

    2016-10-15

    Computed tomography (CT) is considered one of the most important methods of medical imaging employed nowadays, due to its non-invasiveness and the high quality of the images it is able to generate. However, the diagnostic radiation dose received by an individual over the year often exceeds the dose received on account of background radiation. Therefore, it is important to know and to control the dose distribution in the patient by varying the image acquisition parameters. The aim of this study is to evaluate the variation of the image quality of chest CT scans performed by two phantoms. In this paper, a cylindrical Polymethyl Methacrylate (PMMA) chest phantom was used and a second PMMA phantom has been developed with the same volume but an oblong shape, based on the actual dimensions of a male human thorax, in the axillary region. Ten-centimeter scans of the central area of each phantom were performed by a 16-channel Toshiba CT scanner, model Alexion. The scanning protocol employed was the radiology service protocol for chest scans. The noise survey was conducted within the image of the center slice, in five regions: one central and four peripheral areas close to the edge of the object (anterior, posterior, left and right). The recorded values showed that the oblong phantom, with a shape that is more similar to the actual human chest, has a considerably smaller noise, especially in the anterior, posterior and central regions. (Author)

  3. The role of ultrasonography in the imaging of body packers comparison with CT: a prospective study.

    Science.gov (United States)

    Cengel, Ferhat; Bulakci, Mesut; Selcuk, Tuba; Savas, Yildiray; Ceyhan, Muhammet; Kocak, Ayhan; Bilgili, Cigdem Ozkara

    2015-10-01

    This study investigated the sonographic properties of drug packets containing narcotic drugs and the diagnostic role of ultrasonography in detecting body packing in comparison with CT. Forty-five suspects admitted to our hospital for diagnosis and management were routinely evaluated by non-contrast CT for the presence of drug packets. A single radiologist blind to CT data independently performed the abdominal ultrasonographic scans. Thirty-five of 45 suspects were carrying packets. In positive cases, two types of packets with different properties were noted. Twenty-eight cases had type 1 packets (solid form drug) and 7 had type 2 packets (liquid form cocaine). The sensitivity, specificity, positive, and negative predictive values of ultrasonography for detecting drug packets were 91%, 70%, 91%, and 70%, respectively. Ultrasonography accurately determined the presence or absence of packs in 39 of 45 suspects. Ultrasonography was found to have a high sensitivity but a low specificity in suspected cases. A negative ultrasonography cannot rule out the diagnosis of body packing. However, it may be preferred as the initial imaging method or for follow-up of suspected cases as a radiation-free, easy-to-use, and inexpensive technique.

  4. Dynamic telecytologic evaluation of imprint cytology samples from CT-guided lung biopsies: A feasibility study

    Energy Technology Data Exchange (ETDEWEB)

    Prosch, Helmut [Otto Wagner Hospital, Department of Radiology, Vienna (Austria); Medical University of Vienna, Department of Radiology, Vienna (Austria); Medical University of Vienna, Vienna General Hospital, Department of Radiology, Vienna (Austria); Hoffmann, Elisabeth; Schober, Ewald; Mostbeck, Gerhard [Otto Wagner Hospital, Department of Radiology, Vienna (Austria); Bernhardt, Klaus; Schalleschak, Johann [Otto Wagner Hospital, Department of Laboratory Medicine, Vienna (Austria); Rowhani, Marcel [Otto Wagner Hospital, Department of Respiratory and Critical Care Medicine, Vienna (Austria); Weber, Michael [Medical University of Vienna, Department of Radiology, Vienna (Austria)

    2011-09-15

    This study assessed the feasibility of telecytological evaluation of samples from CT-guided lung biopsies using a dynamic telecytological system in which the microscope was operated by personnel from the radiology department at the site of the biopsy and a cytologist off-site diagnosed the biopsy sample. 45 imprint samples from CT-guided biopsies of lung lesions were reviewed by two cytologists using a telecytological microscope (Olympus BX51, Tokyo, Japan). The telecytological microscope was operated by one radiologist and one radiology technician. The cytological samples were classified by a cytologist into four categories: benign, malignant, atypical cells of undetermined significance, and non-diagnostic. The results were compared with those of a previous consensus reading of two independent cytologists (gold standard). When the radiologist was operating the microscope, the diagnostic accuracy was 100% as both cytologists came to the correct diagnosis in all samples. When the technician operated the microscope, two diagnoses of cyotologist 1 differed from the gold standard. Thus, the accuracy for the technician was 95.56%. Telecytological evaluation of imprint samples from CT-guided lung biopsies is feasible because it can be performed with high diagnostic accuracy if personnel from the radiology department operate the microscope. (orig.)

  5. Study of the CT peripheral dose variation in a chest phantom

    Energy Technology Data Exchange (ETDEWEB)

    Alonso, T. C.; Da Silva, T. A. [Development Center of Nuclear Technology / CNEN, Av. Pte. Antonio Carlos 6627, 31270-901 Belo Horizonte, Minas Gerais (Brazil); Mourao F, A. P., E-mail: alonso@cdtn.br [Federal University of Minas Gerais, Nuclear Energy Department, Program of Nuclear Science and Techniques, 31270-901 Belo Horizonte, Minas Gerais (Brazil)

    2015-10-15

    Full text: Computed Tomography (CT) grows every year and is a diagnostic method that has revolutionized radiology with advances in procedures for obtaining image. However, the indiscriminate use of this method generates relatively high doses in patients. The diagnostic reference levels (DRL) is a practical tool to promote the evaluation of existing protocols. The optimization and the periodic review of the protocols are important to balance the risk of radiation. The purpose of this study is to investigate, in a chest scan, the variation of dose in CT. To measure the dose profile are used lithium fluoride thermoluminescent dosimeters distributed in cylinders positioned in peripheral and central regions of a phantom of polymethylmethacrylate (PMMA). The data obtained allow to observe the variation of the dose profile inside the phantom. The peripheral region shows higher dose values than the central region. The longitudinal variation can be observed and the maximum dose was recorded at the edges of the phantom (15,99 ± 2,80) mGy at the midpoint of the longitudinal axis. The results will contribute to disseminate the proper procedure and optimize the dosimetry and the tests of quality control in CT, as well as make a critical analysis of the DRL. (Author)

  6. Acceptability, benefit and costs of early screening for hearing disability: a study of potential screening tests and models.

    Science.gov (United States)

    Davis, A; Smith, P; Ferguson, M; Stephens, D; Gianopoulos, I

    2007-10-01

    To show that hearing loss has such a high prevalence in the older population to justify screening, if effective and acceptable methods are available; and that population take-up and benefit can make a measurable outcome difference in quality of life. A population study of people aged 55-74 years was undertaken. A clinical effectiveness study of differently organised screening programmes was carried out using a controlled trial to identify those who might benefit from intervention (and the extent of the benefit). A retrospective case-control study examined the very long-term (more than 10 years) compliance of patients in using their hearing aids after early identification and determined the extent to which early-identified hearing-impaired people have better outcomes than equivalent people identified later. An examination of the costs and cost-effectiveness of different potential screening programmes was also undertaken. A population study was designed in the UK, with specific stages being conducted in more depth on a sample of people from Nottingham and Southampton. The clinical effectiveness study was conducted in general practices in Nottingham and Bath using a systematic or opportunistic screen. The retrospective case-control study compared a group of early-identified hearing aid users, with control matched for age, gender and occupation, in Cardiff, Glasgow and Manchester. In Great Britain responses were obtained for 34,362 individuals from the postal questionnaire as part of a population study, 506 were interviewed, 351 were assessed for benefit from amplification and 87 were fitted with a hearing aid. The clinical effectiveness study received 1461 replies from the first-stage questionnaire screen, with 306 people assessed in the clinic, of whom 156 were fitted with hearing aids. The retrospective case-control study traced 116 previously fitted hearing aid users, who had been identified by a screen, and then conducted a case-control using 50 of these for whom

  7. Screening frequency and histologic type influence the efficacy of cervical cancer screening: A nationwide cohort study.

    Science.gov (United States)

    Chiang, Ying-Cheng; Chen, Yun-Yuan; Hsieh, Shu-Feng; Chiang, Chun-Ju; You, San-Lin; Cheng, Wen-Fang; Lai, Mei-Shu; Chen, Chi-An

    2017-08-01

    To evaluate the influence of age, screening interval, and histologic type on the effect of Pap smears in cervical cancer screening. Data were retrieved from the Taiwan National Cancer Registry and Cervical Cancer Screening Registration System for the period from 2002 to 2010. Age, Pap smear interval, FIGO stage, and histology were further analyzed. A total of 12,294 women with cervical cancer were enrolled, including 10,040 with squamous cell carcinoma (SCC), 1720 with adenocarcinoma (ADC), 401 with adenosquamous carcinoma (ASC), and 133 with small cell neuroendocrine carcinoma (SMC). Women who had a Pap smear at an interval of <3 years had a significantly higher proportion of stage I disease than women who had never undergone cervical cancer screening (p < 0.0001). Greater than 40% of women with SCCs in each age group had never had a Pap smear; however, women with ADCs were predominantly in the younger age and greater than 40% of women with ADCs had Pap smear at intervals < 3 years. Pap smear is more effective in screening for cervical SCCs compared to cervical ADCs. Improving adherence to screening recommendations is important for the prevention of cervical SCC, especially in elderly women. Copyright © 2017. Published by Elsevier B.V.

  8. A comparative study of SPECT/CT fusion imaging and CT in infiltrated mandible by gingival carcinoma%牙龈癌侵犯下颌骨SPECT/CT融合显像和CT影像的对照研究

    Institute of Scientific and Technical Information of China (English)

    Hongwei Liu; Guichang Li; Ningyi Li; Jie Wang; Baomei Fang

    2009-01-01

    Objective: The aim of the study was to evaluate the clinical value of99mTc-methylene diphosphonic acid (MDP) SPECT/CT fusion imaging and CT scanning in diagnosis of infiltrated mandible by gingival carcinoma. Methods: 18 cases of gingival carcinoma were processed infiltrated mandible by99mTc-MDP SPECT/CT fusion image and CT, and their scanning results compared with pathology findings. Results: Eleven of 13 cases with well-differentiated squamous cell carcinoma showed positive images, one of 11 cases was false positive images by pathology findings, and 10 cases were exhibited infil-trated mandibles; 5 cases with moderately differentiated and poorly differentiated squamous cell carcinoma showed positive images, pathology showed carcinoma cell had infiltrated cavum ossis of mandible. Five of 18 cases were positive images by CT. Conclusion: 99mTc-MDP SPECT/CT fusion imaging is a useful method in diagnosis of infiltrated mandible by gingival carcinoma.

  9. Long-term follow-up of non-calcified pulmonary nodules (<10 mm) identified during low-dose CT screening for lung cancer

    Energy Technology Data Exchange (ETDEWEB)

    Slattery, Michael M.; Logan, P.M.; Lee, Michael J. [Beaumont Hospital, Department of Radiology, Dublin (Ireland); Foley, Claire; Kenny, Dermot [Beaumont Hospital, Clinical Research Centre, RCSI, Dublin (Ireland); Costello, Richard W. [Beaumont Hospital, Respiratory Division, Dublin (Ireland)

    2012-09-15

    To assess the long-term stability of small (<10 mm) non-calcified pulmonary nodules (NCNs) in high-risk subjects initially screened for lung cancer using low-dose chest computed tomography (LDCCT). A total of 449 subjects initially underwent screening with serial LDCCT over a 2-year period. Participants identified as having NCNs {>=}10 mm were referred for formal lung cancer workup. NCNs <10 mm diameter were followed in accordance with the study protocol. Seven years after baseline screening, subjects with previously documented NCNs <10 mm, which were unchanged in size after the 2-year follow-up period, were re-imaged using LDCCT to assess for interval nodule growth. Eighty-three subjects with previously documented stable NCNs <10 mm underwent LDCCT at 7 years. NCNs were unchanged in 78 subjects and had decreased in size in 4 subjects. There was interval growth of an NCN (from 6 mm to 9 mm) in one subject re-imaged at 7 years, but this nodule has remained stable in size over a further 2-year follow-up period. Non-calcified pulmonary nodules <10 mm in size that are unchanged in size or smaller after 2 years of follow-up with LDCCT are most likely benign. (orig.)

  10. Efficiency of ultrasonography and CT angiography in follow-up studies of carotid stent and percutaneous transluminal angioplasty

    Energy Technology Data Exchange (ETDEWEB)

    Ryu, Chang Woo; Lee, Byung Hee; Chung, Bong Sub; Ahn, Jung Yong; Heo, Kyung; Kho, Young Sik [Pundang CHA General Hospital, Pochon CHA Univ. College of Medicine, Pochon (Korea, Republic of)

    1999-12-01

    The aim of this study was to determine a more appropriate method for follow-up of carotid stenting by comparing the efficiency of US and CT angiography. Eleven carotid arteries of seven patients(men:5, women:2, mean age:56.4years) who underwent stent placement and percutaneous transluminal angioplasty(PTA) because of carotid stenosis were studied. The follow-up periods ranged from three to eleven (mean, five) months, and US and CT angiography were performed in one day. Color duplex sonography was performed with a 10 MHz linear array transducer. After spiral CT scan were obtained, MPR images were reconstructed on a workstation. Retrospective imaging analysis specifically focused on [1] stent configuration, [2] the accuracy of internal diameter measurement, [3] the detection of blood flow and the measurement of blood flow velocity, [4] the presence of atheroma and intraluminal thrombi, [5] the measurement of stent location, and [6] artifacts. US was more accurate than CT angiography for measuring internal diameter. In all cases, US and CT angiography were able to detect the blood flow at carotid artery, and utilizing the Doppler spectrum, flow velocity was measured. US showed atheromas in all cases but CT angiography demonstrated calcified atheromas in three cases only. In six cases, US failed to determine stent location, though in this respect CT angiography was successful in all cases. Artifacts of US were small reverberation artifact(11/11) of the stent and a defective color Doppler signal caused by acoustic shadowing of atheroma calcification(3/11). Artifacts of CT angiogrpahy were hardbeam artifact of the stent(11/11) and motion artifact(3/11). US was superior to CT angiography in accuracy of measuring stent diameter, hemodynamic assessment, high-resolution views of the luminal state of the stent and minimal artifacts for the non-invasive follow-up studies of carotid stenting.

  11. Development and validation study of the Smartphone Overuse Screening Questionnaire.

    Science.gov (United States)

    Lee, Han-Kyeong; Kim, Ji-Hae; Fava, Maurizio; Mischoulon, David; Park, Jae-Hyun; Shim, Eun-Jung; Lee, Eun-Ho; Lee, Ji Hyeon; Jeon, Hong Jin

    2017-08-02

    The aim of this study was to develop a screening questionnaire that could distinguish individuals at high risk of smartphone overuse from casual users. The reliability, validity, and diagnostic ability of the Smartphone Overuse Screening Questionnaire (SOS-Q) were evaluated. Preliminary items were assessed by 50 addiction experts on-line, and 28 questions were selected. A total of 158 subjects recruited from six community centers for internet addiction participated in this study. The SOS-Q, Young's internet addiction scale, Korean scale for internet addiction, and Smartphone Scale for Smartphone Addiction (S-Scale) were used to assess the concurrent validity. Construct validity was supported by a six-factor model using an exploratory factor analysis. The internal consistency and the item-total correlations were favorable (α = 0.95, r = 0.35-0.81). The test-retest reliability was moderate (r = 0.70). The SOS-Q showed superior concurrent validity with the highest correlation between the S-Scale (r = 0.76). Receiver operating characteristic curve analysis revealed an area under the curve of 0.877. A cut-off point of 49 effectively categorized addiction high-risk group with a sensitivity of 0.81 and specificity of 0.86. Overall, the current study supports the use of SOS-Q as both a primary and supplementary measurement tool in a variety of settings. Copyright © 2017 Elsevier Ireland Ltd. All rights reserved.

  12. Unilateral adrenal hyperplasia is a usual cause of primary hyperaldosteronism. Results from a Swedish screening study

    Directory of Open Access Journals (Sweden)

    Sigurjonsdottir Helga

    2012-09-01

    Full Text Available Abstract Background The existence of unilateral adrenal hyperplasia (AH has been considered a rare cause of primary hyperaldosteronism (PA. Methods In a prospective study we screened for PA in a non-selected (NSP and selected hypertensive population (SP, to define the cause of PA. We included 353 consecutive patients with hypertension; age 20 to 88 years, 165 women and 188 men, from a university-based Hypertension and Nephrology Outpatient clinics (123 SP and two primary care centres, (230 NSP from the same catch-up area. Serum aldosterone and plasma renin activity (PRA were measured and the ARR calculated. Verifying diagnostic procedure was performed in patients with both elevated aldosterone and ARR. Patients diagnosed with PA were invited for adrenal venous sampling (AVS and offered laparoscopic adrenalectomy when AVS found the disease to be unilateral. Results After screening, 46 patients, 13% of the whole population (22.8% SP and 7.8% NSP had aldosterone and ARR above the locally defined cut-off limits (0.43 nmol/l and 1.28 respectively. After diagnostic verification, 20 patients (6% had PA, (14.5% SP and 1.4% NSP. Imaging diagnostic procedures with CT-scans and scintigraphy were inconclusive. AVS, performed in 15 patients verified bilateral disease in 4 and unilateral in 10 patients. One AVS failed. After laparoscopic adrenalectomy, 4 patients were found to have adenoma and 5 unilateral AH. One patient denied operation. Conclusion The prevalence of PA was in agreement with previous studies. The study finds unilateral PA common and unilateral AH as half of those cases. As may be suspected PA is found in much higher frequency in specialised hypertensive units compared to primary care centers. AVS was mandatory in diagnosis of unilateral PA.

  13. Strategy study of quantification harmonization of SUV in PET/CT images; Estudo da estrategia de harmonizacao da quantificacao do SUV em imagens de PET/CT

    Energy Technology Data Exchange (ETDEWEB)

    Fischer, Andreia Caroline Fischer da Silveira

    2014-07-01

    In clinical practice, PET/CT images are often analyzed qualitatively by visual comparison of tumor lesions and normal tissues uptake; and semi-quantitatively by means of a parameter called SUV (Standardized Uptake Value). To ensure that longitudinal studies acquired on different scanners are interchangeable, and information of quantification is comparable, it is necessary to establish a strategy to harmonize the quantification of SUV. The aim of this study is to evaluate the strategy to harmonize the quantification of PET/CT images, performed with different scanner models and manufacturers. For this purpose, a survey of the technical characteristics of equipment and acquisition protocols of clinical images of different services of PET/CT in the state of Rio Grande do Sul was conducted. For each scanner, the accuracy of SUV quantification, and the Recovery Coefficient (RC) curves were determined, using the reconstruction parameters clinically relevant and available. From these data, harmonized performance specifications among the evaluated scanners were identified, as well as the algorithm that produces, for each one, the most accurate quantification. Finally, the most appropriate reconstruction parameters to harmonize the SUV quantification in each scanner, either regionally or internationally were identified. It was found that the RC values of the analyzed scanners proved to be overestimated by up to 38%, particularly for objects larger than 17mm. These results demonstrate the need for further optimization, through the reconstruction parameters modification, and even the change of the reconstruction algorithm used in each scanner. It was observed that there is a decoupling between the best image for PET/CT qualitative analysis and the best image for quantification studies. Thus, the choice of reconstruction method should be tied to the purpose of the PET/CT study in question, since the same reconstruction algorithm is not adequate, in one scanner, for qualitative

  14. Results of the Austrian CT dose study 2010. Typical effective doses of the most frequent CT examinations; Ergebnisse der Oesterreichischen CT-Dosisstudie 2010. Effektive Dosen der haeufigsten CT-Untersuchungen und Unterschiede zwischen Anwendern

    Energy Technology Data Exchange (ETDEWEB)

    Homolka, Peter; Leithner, Robert; Billinger, Jochen [Medizinische Universitaet Wien (Austria). Zentrum fuer Medizinische Physik und Biomedizinische Technik; Gruber, Michael [Medizinische Universitaet Wien (Austria). Universitaetsklinik fuer Radiologie und Nuklearmedizin

    2014-10-01

    Purpose: To determine typical doses from common CT examinations of standard sized adult patients and their variability between CT operators for common CT indications. Materials and Methods: In a nationwide Austrian CT dose survey doses from approx. 10,000 common CT examinations of adults during 2009 and 2010 were collected and 'typical' radiation doses to the 'average patient', which turned out to have 75.6 kg body mass, calculated. Conversion coefficients from DLP to effective dose were determined and effective doses calculated according to ICRP 103. Variations of typically applied doses to the 'average patient' were expressed as ratios between 90{sup th} and 10{sup th} percentile (inter-percentile width, IPW90/10), 1st and 3{sup rd} quartile (IPW75/25), and Maximum/Minimum. Results: Median effective doses to the average patients for standard head and neck scans were 1.8 mSv (cervical spine), 1.9 mSv (brain: trauma/bleeding, stroke) to 2.2 mSv (brain: masses) with typical variation between facilities of a factor 2.5 (IPW90/10) and 1.7 (IPW75/25). In the thorax region doses were 6.4 to 6.8 mSv (pulmonary embolism, pneumonia and inflammation, oncologic scans), the variation between facilities was by a factor of 2.1 (IPW90/10) and 1.5 (IPW75/25), respectively. In the abdominal region median effective doses from 6.5 mSv (kidney stone search) to 22 mSv (liver lesions) were found (acute abdomen, staging/metastases, lumbar spine: 9-12 mSv; oncologic abdomen plus chest 16 mSv; renal tumor 20 mSv). Variation factors between facilities were on average for abdominal scans 2.7 (IPW90/10) and 1.8 (IPW75/25). Conclusion: Variations between CT operators are generally moderate for most operators, but in some indications the ratio between the minimum and the maximum of average dose to the typical standard patients exceeds a factor of 4 or even 5. Therefore, comparing average doses to Diagnostic Reference Levels (DRLs) and optimizing protocols need to

  15. ACCURACY AND PRECISION OF A METHOD TO STUDY KINEMATICS OF THE TEMPOROMANDIBULAR JOINT: COMBINATION OF MOTION DATA AND CT IMAGING

    OpenAIRE

    Baltali, Evre; Zhao, Kristin D.; Koff, Matthew F.; Keller, Eugene E.; An, Kai-Nan

    2008-01-01

    The purpose of the study was to test the precision and accuracy of a method used to track selected landmarks during motion of the temporomandibular joint (TMJ). A precision phantom device was constructed and relative motions between two rigid bodies on the phantom device were measured using optoelectronic (OE) and electromagnetic (EM) motion tracking devices. The motion recordings were also combined with a 3D CT image for each type of motion tracking system (EM+CT and OE+CT) to mimic methods ...

  16. Comprehensive study of LASL Well C/T-2 Roosevelt Hot Springs KGRA, Utah, and applications to geothermal well logging

    Energy Technology Data Exchange (ETDEWEB)

    Glenn, W.E.; Hulen, J.B.; Nielson, D.L.

    1981-02-01

    Utah State Geothermal Well 9-1 in the Roosevelt Hot Springs KGRA, Beaver County, Utah, has been donated by Phillips Petroleum Company for calibration and testing of well-logging equipment in the hot, corrosive, geothermal environment. It is the second Calibration/Test Well (C/T-2) in the Geothermal Log Interpretation Program. A study of cuttings and well logs from Well C/T-2 was completed. This synthesis and data presentation contains most of the subsurface geologic information needed to effect the total evaluation of geophysical logs acquired in this geothermal calibration/test well, C/T-2.

  17. Controversies about cervical cancer screening: A qualitative study of Roma women's (non)participation in cervical cancer screening in Romania.

    Science.gov (United States)

    Andreassen, Trude; Weiderpass, Elisabete; Nicula, Florian; Suteu, Ofelia; Itu, Andreea; Bumbu, Minodora; Tincu, Aida; Ursin, Giske; Moen, Kåre

    2017-06-01

    Romania has Europe's highest incidence and mortality of cervical cancer. While a free national cervical cancer-screening programme has been in operation since 2012, participation in the programme is low, particularly in minority populations. The aim of this study was to explore Roma women's (non)participation in the programme from women's own perspectives and those of healthcare providers and policy makers. We carried out fieldwork for a period of 125 days in 2015/16 involving 144 study participants in Cluj and Bucharest counties. Fieldwork entailed participant observation, qualitative interviewing and focus group discussions. A striking finding was that screening providers and Roma women had highly different takes on the national screening programme. We identified four fundamental questions about which there was considerable disagreement between them: whether a free national screening programme existed in the first place, whether Roma women were meant to be included in the programme if it did, whether Roma women wanted to take part in screening, and to what degree screening participation would really benefit women's health. On the background of insights from actor-network theory, the article discusses to what degree the programme could be said to speak to the interest of its intended Roma public, and considers the controversies in light of the literature on patient centred care and user involvement in health care. The paper contributes to the understanding of the health and health-related circumstances of the largest minority in Europe. It also problematizes the use of the concept of "barriers" in research into participation in cancer screening, and exemplifies how user involvement can potentially help transform and improve screening programmes. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  18. Overdiagnosis in organised mammography screening in Denmark. A comparative study

    DEFF Research Database (Denmark)

    Jørgensen, Karsten J; Zahl, Per-Henrik; Gøtzsche, Peter C

    2009-01-01

    BACKGROUND: Overdiagnosis in cancer screening is the detection of cancer lesions that would otherwise not have been detected. It is arguably the most important harm. We quantified overdiagnosis in the Danish mammography screening programme, which is uniquely suited for this purpose, as only 20......% of the Danish population has been offered organised mammography screening over a long time-period. METHODS: We collected incidence rates of carcinoma in situ and invasive breast cancer in areas with and without screening over 13 years with screening (1991-2003), and 20 years before its introduction (1971...

  19. A study of the short- to long-phantom dose ratios for CT scanning without table translation

    Energy Technology Data Exchange (ETDEWEB)

    Li, Xinhua; Zhang, Da; Liu, Bob, E-mail: bliu7@mgh.harvard.edu [Division of Diagnostic Imaging Physics, Department of Radiology, Massachusetts General Hospital, Boston, Massachusetts 02114 and Webster Center for Advanced Research and Education in Radiation, Department of Radiology, Massachusetts General Hospital, Boston, Massachusetts 02114 (United States); Yang, Jie [Pinnacle Health - Fox Chase Regional Cancer Center, Harrisburg, Pennsylvania 17109 (United States)

    2014-09-15

    Purpose: For CT scanning in the stationary-table modes, AAPM Task Group 111 proposed to measure the midpoint dose on the central and peripheral axes of sufficiently long phantoms. Currently, a long cylindrical phantom is usually not available in many clinical facilities. The use of a long phantom is also challenging because of the heavy weight. In order to shed light on assessing the midpoint dose in CT scanning without table movement, the authors present a study of the short- to long-phantom dose ratios, and perform a cross-comparison of CT dose ratios on different scanner models. Methods: The authors performed Geant4-based Monte Carlo simulations with a clinical CT scanner (Somatom Definition dual source CT, Siemens Healthcare), and modeled dosimetry measurements using a 0.6 cm{sup 3} Farmer type chamber and a 10-cm long pencil ion chamber. The short (15 cm) to long (90 cm) phantom dose ratios were computed for two PMMA diameters (16 and 32 cm), two phantom axes (the center and the periphery), and a range of beam apertures (3–25 cm). The results were compared with the published data of previous studies with other multiple detector CT (MDCT) scanners and cone beam CT (CBCT) scanners. Results: The short- to long-phantom dose ratios changed with beam apertures but were insensitive to beam qualities (80–140 kV, the head and body bowtie filters) and MDCT and CBCT scanner models. Conclusions: The short- to long-phantom dose ratios enable medical physicists to make dosimetry measurements using the standard CT dosimetry phantoms and a Farmer chamber or a 10 cm long pencil chamber, and to assess the midpoint dose in long phantoms. This method provides an effective approach for the dosimetry of CBCT scanning in the stationary-table modes, and is useful for perfusion and interventional CT.

  20. Moving mammogram-reluctant women to screening: a pilot study.

    Science.gov (United States)

    Costanza, Mary E; Luckmann, Roger; White, Mary Jo; Rosal, Milagros C; LaPelle, Nancy; Cranos, Caroline

    2009-06-01

    Effective interventions are needed for women long overdue for screening mammography. The purpose of this study is to pilot test an intervention for motivating overdue women to receive a mammogram. Subjects aged 45-79 without a mammogram in > or =27 months and enrolled in study practices were identified from claims data. The intervention included a mailed, educational booklet, computer-assisted barrier-specific tailored counseling and motivational interviewing, and facilitated, short-interval mammography scheduling. Of 127 eligible women, 45 (35.4%) agreed to counseling and data collection. Most were > or =3 years overdue. Twenty-six (57.8%) of the counseled women got a mammogram within 12 months. Thirty-one (72.1%) of 43 counseled women moved > or =1 stage closer to screening, based on a modified Precaution Adoption Process Model. It is feasible to reach and counsel women who are long overdue for a mammogram and to advance their stage of adoption. The intervention should be formally evaluated in a prospective trial comparing it to control or to proven interventions.

  1. Optimization of the imaging quality of 64-slice CT acquisition protocol using Taguchi analysis: A phantom study.

    Science.gov (United States)

    Pan, Lung Fa; Erdene, Erdenetsetseg; Chen, Chun Chi; Pan, Lung Kwang

    2015-01-01

    In this study, the phantom imaging quality of 64-slice CT acquisition protocol was quantitatively evaluated using Taguchi. The phantom acrylic line group was designed and assembled with multiple layers of solid water plate in order to imitate the adult abdomen, and scanned with Philips brilliance CT in order to simulate a clinical examination. According to the Taguchi L8(2(7)) orthogonal array, four major factors of the acquisition protocol were optimized, including (A) CT slice thickness, (B) the image reconstruction filter type, (C) the spiral CT pitch, and (D) the matrix size. The reconstructed line group phantom image was counted by four radiologists for three discrete rounds in order to obtain the averages and standard deviations of the line counts and the corresponding signal to noise ratios (S/N). The quantified S/N values were analyzed and the optimal combination of the four factor settings was determined to be comprised of (A) a 1-mm thickness, (B) a sharp filter type, (C) a 1.172 spiral CT pitch, and (D) a 1024×1024 matrix size. The dominant factors included the (A) filter type and the cross interaction between the filter type and CT slice thickness (A×B). The minor factors were determined to be (C) the spiral CT pitch and (D) the matrix size since neither was capable of yielding a 95% confidence level in the ANOVA test.

  2. The pros and cons of intraoperative CT scan in evaluation of deep brain stimulation lead implantation: A retrospective study

    Science.gov (United States)

    Servello, Domenico; Zekaj, Edvin; Saleh, Christian; Pacchetti, Claudio; Porta, Mauro

    2016-01-01

    Background: Deep brain stimulation (DBS) is an established therapy for movement disorders, such as Parkinson's disease (PD), dystonia, and tremor. The efficacy of DBS depends on the correct lead positioning. The commonly adopted postoperative radiological evaluation is performed with computed tomography (CT) scan and/or magnetic resonance imaging (MRI). Methods: We conducted a retrospective study on 202 patients who underwent DBS from January 2009 to October 2013. DBS indications were PD, progressive supranuclear palsy, tremor, dystonia, Tourette syndrome, obsessive compulsive disorder, depression, and Huntington's disease. Preoperatively, all patients underwent brain MRI and brain CT scan with the stereotactic frame positioned. The lead location was confirmed intraoperatively with CT. The CT images were subsequently transferred to the Stealth Station Medtronic and merged with the preoperative planning. On the first or second day after, implantation we performed a brain MRI to confirm the correct position of the lead. Results: In 14 patients, leads were in suboptimal position after intraoperative CT scan positioning. The cases with alteration in the Z-axis were corrected immediately under fluoroscopic guidance. In all the 14 patients, an immediate repositioning was done. Conclusions: Based on our data, intraoperative CT scan is fast, safe, and a useful tool in the evaluation of the position of the implanted lead. It also reduces the patient's discomfort derived from the transfer of the patient from the operating room to the radiological department. However, intraoperative CT should not be considered as a substitute for postoperative MRI. PMID:27583182

  3. Four cases of large cell neuroendocrine carcinoma of the stomach: findings on CT and barium studies

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hee Jung; Choi, Dong Il; Lee, Soon Jin; Lee, Won Jae; Kim, Sung; Kim, Jae J.; Park, Cheol Keun [Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of)

    2008-06-15

    A large cell neuroendocrine carcinoma of the stomach is extremely rare. We have reviewed the medical records and imaging studies of the four patients that presented with a large cell neuroendocrine carcinomas of the stomach. On a barium study and CT imaging, a gastric large cell neuroendocrine carcinoma is depicted as an ulcerofungating tumor with minimal peritumoral infiltration and metastatic lymphadenopathy in the perigastric area. These findings are similar to findings for advanced gastric cancer, especially Borrmann type II. However, a gastric large cell neuroendocrine carcinoma is highly malignant with a significantly worse prognosis than a usual adenocarcinoma.

  4. ANATOMICAL VARIATIONS IN SINONASAL REGION IN CASES OF SINUS HEADACHE - CT SCAN - PNS STUDY

    Directory of Open Access Journals (Sweden)

    Arun Kumar

    2015-08-01

    Full Text Available BACKGROUND: Sinus headache secondary to Chronic Rhinosinusitis refers to episode of pain over the sinus area of the face and is often associated with nasal congestion, rhinorrhea, facial pressure, lacrimation, nausea and sensory sensitivity. Any small lesions or anatomical variations over lateral wall of nose may giv e rise to sinus headache. CT scan play a vital role in accurate assessment of osteomeatal complex area and anatomical variations at this site. AIM: To study anatomical variations of osteomeatal complex area and deviated septum in cases of chronic sinus hea dache secondary to Chronic Rhinosinusitis. MATERIALS AND METHODS : This study was conducted in Jhalawar Medical College, ENT Department between Sept. 2012 to Dec. 2014. In this study 75 patients withchronic sinus headache was selected who had chronic headac he for more than 3 months duration not responding to medical line of treatment and who were willing to undergo function endoscopic sinus surgery. All patients underwent for CT scan para nasal sinus. RESULT: In this study deviated nasal septum was found in 77.33% patients, apart from that it was observed that 54.66% of the sinus headache cases had two or more anatomical variations and 28% had single anatomical variations, out of them commonest finding is concha bullosa followed by enlarge bulla ethmoid, para doxical middle turbinate, medialiseduncinate process, lateraliseduncinate process, prominent aggar nasi cells, haller cells and onodi cells in decreasing order . CONCLUSION: The study of CT scan PNS conclude that Deviated Nasal Septum and anatomical variati ons at lateral wall of nose causes narrowing of osteomeatal complex area which predisposed patients to sino nasal disease and sinus headache

  5. Quantitative analysis of airway abnormalities in CT

    DEFF Research Database (Denmark)

    Petersen, Jens; Lo, P.; Nielsen, Mads;

    2010-01-01

    A coupled surface graph cut algorithm for airway wall segmentation from Computed Tomography (CT) images is presented. Using cost functions that highlight both inner and outer wall borders, the method combines the search for both borders into one graph cut. The proposed method is evaluated on 173...... Area (IA) and Wall Area percentage (WA%) was measured by the proposed method on a total of 723 CT scans from a lung cancer screening study. These measures were significantly different for participants with Chronic Obstructive Pulmonary Disease (COPD) compared to asymptomatic participants. Furthermore...

  6. Functional Study of the Heart using MRI and Multi-slice CT (MSCT

    Directory of Open Access Journals (Sweden)

    "Sh. Akhlaghpour

    2005-08-01

    Full Text Available Introduction & Background: By using newer imaging techniques (MRI and MSCT, it is possible to perform functional studies of the heart including, wall mo-tion, chamber volume evaluation, and myocardial mass and wall thickness. While MRI had recently been introduced as the gold standard method for the morphological and functional studies of the heart, recent advances in the number of detectors, rotation time, and reconstruction protocols made Multislice CT (MSCT another new application for functional studies of the heart too. Ordinary raw data for coro-nary CT angiography is sufficient for these functional studies. Apart from the point that which technique is to be used to get a standard and reproducible meas-urement, a proper imaging strategy is necessary. To use MSCT, various softwares are available for these studies. By the use of these two modalities, valvular evaluations are also possible as addressed in many recent publications. In this article the strategy for functional study of the heart is presented and some case studies are also discussed.

  7. CONTRAST STUDY ON CT AND BA IN DIAGNOSIS OF PATIENTS WITH ATHEROTHROMBOTIC BRAIN INFARCTION

    Institute of Scientific and Technical Information of China (English)

    Mingshun Liu; Haixiang Gao; Xiaomei Fu; Po Ma

    2007-01-01

    Objectives: To explore applied value on CT and BA in diagnosis of patients with atherothrombotic brain infarction. Methods:CT and BA were examined in 246 patients with atherothrombotic brain infarction. Results:The different change of CT and BA were showed in 246 patients with atherothrombotic brain infarction. Conclusions: There were separately different advantage and shortcoming in CT and BA in diagnosis of atherothrombotic brain infarction. The value of clinical application of BA was important in diagnosis of atherothrombotic brain infarction.

  8. Your Radiologist Explains CT Colonography

    Medline Plus

    Full Text Available ... is National Prostate Cancer Awareness Month Recently posted: Medical Imaging Costs Magnetoencephalography (MEG) Video: Coronary CT Angiography Video: ... commonly known, virtual colonoscopy. Virtual colonoscopy is a diagnostic imaging test that is used to screen the large ...

  9. Brain volume perfusion CT performed with 128-detector row CT system in patients with cerebral gliomas: A feasibility study

    Energy Technology Data Exchange (ETDEWEB)

    Xyda, Argyro [University Hospital of Goettingen, Department of Neuroradiology, Georg-August University, Goettingen (Germany); University Hospital of Heraklion, Department of Radiology, Crete (Greece); Haberland, Ulrike; Klotz, Ernst [Computed Tomography, Siemens AG Healthcare Sector, Forchheim (Germany); Bock, Hans Christoph [University Hospital of Goettingen, Department of Neurosurgery, Georg-August University, Goettingen (Germany); Jung, Klaus [University Hospital of Goettingen, Department of Medical Statistics, Georg-August University, Goettingen (Germany); Knauth, Michael; Schramm, Ramona; Psychogios, Marios Nikos; Schramm, Peter [University Hospital of Goettingen, Department of Neuroradiology, Georg-August University, Goettingen (Germany); Erb, Gunter [Bracco Imaging Deutschland GmbH, Konstanz (Germany)

    2011-09-15

    Validation of the feasibility and efficacy of volume perfusion computed tomography (VPCT) in the preoperative assessment of cerebral gliomas by applying a 128-slice CT covering the entire tumour. Forty-six patients (25 men, 21 women; mean age 52.8 years) with cerebral gliomas were evaluated with VPCT. Two readers independently evaluated VPCT data, drawing volumes of interest (VOIs) around the tumour according to maximum intensity projection volumes, which were mapped automatically onto the cerebral blood volume (CBV), flow (CBF) and permeability (Ktrans) perfusion datasets. As control, a second VOI was placed in the contralateral healthy cortex. Correlation among perfusion parameters, tumour grade, hemisphere and VOIs was assessed. The diagnostic power of perfusion parameters was analysed by receiver operating characteristics curve analyses. VPCT was feasible in the assessment of the entire tumour extent. Mean values of Ktrans, CBV, CBF in high-grade gliomas were significantly higher compared with low-grade (p < 0.01). Ktrans demonstrated the highest diagnostic (97% sensitivity), positive (100%) and negative (94%) prognostic values. VPCT was feasible in all subjects. All areas of different perfusion characteristics are depicted and quantified in colour-coded 3D maps. The derived parameters correlate well with tumour histopathology, differentiating low- from high-grade gliomas. (orig.)

  10. Does population screening for Chlamydia trachomatis raise anxiety among those tested? Findings from a population based chlamydia screening study

    Directory of Open Access Journals (Sweden)

    Low Nicola

    2006-04-01

    Full Text Available Abstract Background The advent of urine testing for Chlamydia trachomatis has raised the possibility of large-scale screening for this sexually transmitted infection, which is now the most common in the United Kingdom. The purpose of this study was to investigate the effect of an invitation to be screened for chlamydia and of receiving a negative result on levels of anxiety, depression and self-esteem. Methods 19,773 men and women aged 16 to 39 years, selected at random from 27 general practices in two large city areas (Bristol and Birmingham were invited by post to send home-collected urine samples or vulvo-vaginal swabs for chlamydia testing. Questionnaires enquiring about anxiety, depression and self-esteem were sent to random samples of those offered screening: one month before the dispatch of invitations; when participants returned samples; and after receiving a negative result. Results Home screening was associated with an overall reduction in anxiety scores. An invitation to participate did not increase anxiety levels. Anxiety scores in men were lower after receiving the invitation than at baseline. Amongst women anxiety was reduced after receipt of negative test results. Neither depression nor self-esteem scores were affected by screening. Conclusion Postal screening for chlamydia does not appear to have a negative impact on overall psychological well-being and can lead to a decrease in anxiety levels among respondents. There is, however, a clear difference between men and women in when this reduction occurs.

  11. Study of Coronary Arteries by Means of Multidetector CT; Estudio de las arterias coronarias mediante tomografia computarizada multidetector

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez, G. C.; Costas, M. I.; Delgado, C.; Velasco, M.; Tardaguila, F. [Hospital POVISA. Vigo. Pontevedra (Spain)

    2004-07-01

    Radiological study of coronary arteries has undergone major advances,especially with the incorporation of new CT multidetectors which afford temporary spatial resolution sufficient for the acquisition of high-quality images and diagnoses concerning various coronary artery abnormalities. The technique is described in terms of both facilitating data within a procedure making use of beta-blockers to slow heart rate and postprocess image reconstruction. Accordingly, our experience with a 16-detector CT and its clinical applications are illustrated. (Author)

  12. Factors influencing the decline in lung density in a Danish lung cancer screening cohort

    DEFF Research Database (Denmark)

    Shaker, Saher B.; Dirksen, Asger; Lo, Pechin Chien Pau;

    2012-01-01

    Lung cancer screening trials provide an opportunity to study the natural history of emphysema by using CT lung density as a surrogate parameter.In the Danish Lung Cancer Screening Trial, 2,052 participants were included. At screening rounds, smoking habits were recorded and spirometry was performed...

  13. CT study of 17 cases of congenital cochlear abnormality. Embryologic and anatomo-functional relationship

    OpenAIRE

    Maurício, JC; Biscoito, L; Branco, G.

    1993-01-01

    In this review of cochlear malformations, 17 cases were studied by CT scan (high resolution-target program) including 10 males and 7 females. The anomaly was bilateral in 12 cases and unilateral in 7 (the latter included 2 Mondini type aplasias and one Michel). The cochlear malformation (whose most frequent expression was the cochlear hypoplasia with 1 or 1 1/2 spires-65% of the cases) was associated to semicircular canals and/or vestibular aqueduct anomaly in 82% of the patients; it was excl...

  14. 胸部DR与低剂量螺旋CT扫描在肺癌筛选中的应用观察%Application and Observation of Thoracic DR and Low Dose Spiral CT Scanning in Lung Cancer Screening

    Institute of Scientific and Technical Information of China (English)

    成洪桥

    2014-01-01

    目的:探讨分析胸部DR与低剂量螺旋CT扫描在肺癌筛选中的应用价值。方法选择来我院进行肺癌治疗的300例患者,对他们分别采用胸部DR以及低剂量螺旋CT扫描,统计两种方法的检出率。结果胸部DR检出结节性病变患者24例,占8%,其中肺癌患者3例;低剂量螺旋CT扫描检出结节性病变患者51例,占17%,其中肺癌患者6例,差异具有统计学意义(P<0.05)。结论采用低剂量螺旋CT扫描在肺癌筛选中的应用价值显著,能明显提高检出率。%Objective To investigate the application value of chest DR and low dose spiral CT scanning in lung cancer screening. Methods 300 patients came to our hospital for treatment of lung cancer, they were used on the chest DR and low dose spiral CT scanning, using statistical method for detection rate. Results Chest DR were detected in 24 cases, patients with nodular lesions accounted for 8%, of which 3 cases of lung cancer patients;low dose spiral CT scanning were detected in 51 cases, patients with nodular lesions accounted for 17%, of which 6 cases of lung cancer patients, with significant difference (P<0.05). Conclusion Using low dose spiral CT scanning in lung cancer screening has significant value, it can significantly improve the detection rate.

  15. HPV DNA testing in population-based cervical screening (VUSA-Screen study) : results and implications

    NARCIS (Netherlands)

    Rijkaart, D. C.; Berkhof, J.; van Kemenade, F. J.; Coupe, V. M. H.; Rozendaal, L.; Heideman, D. A. M.; Verheijen, R. H. M.; Bulk, S.; Verweij, W.; Snijders, P. J. F.; Meijer, C. J. L. M.

    2012-01-01

    BACKGROUND: Human papillomavirus (HPV) testing is more sensitive than cytology for detecting high-grade cervical intraepithelial neoplasia (CIN). We evaluated the performance of high-risk HPV (hrHPV) testing in routine screening. METHODS: In all, 25 871 women (29-61) enrolled in our population-based

  16. HPV DNA testing in population-based cervical screening (VUSA-Screen study) : results and implications

    NARCIS (Netherlands)

    Rijkaart, D. C.; Berkhof, J.; van Kemenade, F. J.; Coupe, V. M. H.; Rozendaal, L.; Heideman, D. A. M.; Verheijen, R. H. M.; Bulk, S.; Verweij, W.; Snijders, P. J. F.; Meijer, C. J. L. M.

    2012-01-01

    BACKGROUND: Human papillomavirus (HPV) testing is more sensitive than cytology for detecting high-grade cervical intraepithelial neoplasia (CIN). We evaluated the performance of high-risk HPV (hrHPV) testing in routine screening. METHODS: In all, 25 871 women (29-61) enrolled in our population-based

  17. The Substance Abuse Subtle Screening Inventory-3 and Stages of Change: A Screening Validity Study

    Science.gov (United States)

    Laux, John M.; Piazza, Nick J.; Salyers, Kathleen; Roseman, Christopher P.

    2012-01-01

    The sensitivity of the Substance Abuse Subtle Screening Inventory-3 (SASSI-3) was examined among substance-dependent adults enrolled in a family drug court. The SASSI-3 had a high sensitivity rate with this population, even across varying levels of motivation to change. (Contains 2 tables.)

  18. Evaluation of chemotherapy response in ovarian cancer treatment using quantitative CT image biomarkers: a preliminary study

    Science.gov (United States)

    Qiu, Yuchen; Tan, Maxine; McMeekin, Scott; Thai, Theresa; Moore, Kathleen; Ding, Kai; Liu, Hong; Zheng, Bin

    2015-03-01

    The purpose of this study is to identify and apply quantitative image biomarkers for early prediction of the tumor response to the chemotherapy among the ovarian cancer patients participated in the clinical trials of testing new drugs. In the experiment, we retrospectively selected 30 cases from the patients who participated in Phase I clinical trials of new drug or drug agents for ovarian cancer treatment. Each case is composed of two sets of CT images acquired pre- and post-treatment (4-6 weeks after starting treatment). A computer-aided detection (CAD) scheme was developed to extract and analyze the quantitative image features of the metastatic tumors previously tracked by the radiologists using the standard Response Evaluation Criteria in Solid Tumors (RECIST) guideline. The CAD scheme first segmented 3-D tumor volumes from the background using a hybrid tumor segmentation scheme. Then, for each segmented tumor, CAD computed three quantitative image features including the change of tumor volume, tumor CT number (density) and density variance. The feature changes were calculated between the matched tumors tracked on the CT images acquired pre- and post-treatments. Finally, CAD predicted patient's 6-month progression-free survival (PFS) using a decision-tree based classifier. The performance of the CAD scheme was compared with the RECIST category. The result shows that the CAD scheme achieved a prediction accuracy of 76.7% (23/30 cases) with a Kappa coefficient of 0.493, which is significantly higher than the performance of RECIST prediction with a prediction accuracy and Kappa coefficient of 60% (17/30) and 0.062, respectively. This study demonstrated the feasibility of analyzing quantitative image features to improve the early predicting accuracy of the tumor response to the new testing drugs or therapeutic methods for the ovarian cancer patients.

  19. Thin soil layer of green roof systems studied by X-Ray CT

    Science.gov (United States)

    Šácha, Jan; Jelínková, Vladimíra; Dohnal, Michal

    2016-04-01

    The popular non-invasive visualization technique of X-ray computed tomography (CT) has been used for 3D examination of thin soil layer of vegetated roof systems. The two categories of anthropogenic soils, usually used for green roof systems, were scanned during the first months after green roof system construction. First was represented by stripped topsoil with admixed crushed bricks and was well graded in terms of particle size distribution. The other category represented a commercial lightweight technogenic substrate. The undisturbed soil samples of total volume of 62.8 ccm were studied be means of X-ray Computed Tomography using X-ray Inspection System GE Phoenix Nanomex 180T with resulting spatial resolution about 57 μm in all directions. For both soil categories visible macroporosity, connectivity (described by the Euler characteristic), dimensionless connectivity and critical cross section of pore network were determined. Moreover, the temporal structural changes of studied soils were discussed together with heat and water regime of the green roof system. The analysis of CT images of anthropogenic soils was problematic due to the different X-ray attenuation of individual constituents. The correct determination of the threshold image intensity differentiating the soil constituents from the air phase had substantial importance for soil pore network analyses. However, X-ray CT derived macroporosity profiles reveal significant temporal changes notably in the soil comprised the stripped topsoil with admixed crushed bricks. The results implies that the technogenic substrate is structurally more stable over time compared to the stripped topsoil. The research was realized as a part of the University Centre for Energy Efficient Buildings supported by the EU and with financial support from the Czech Science Foundation under project number 14-10455P.

  20. CT-guided percutaneous cryoablation of osteoid osteoma in children: an initial study

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Bin; Xiao, Yue-Yong; Zhang, Xiao [Chinese PLA General Hospital, Department of Radiology, Beijing (China); Zhao, Lei [Brigham and Women' s Hospital, Harvard Medical School, Department of Radiology, Boston, MA (United States); Carrino, John A. [Johns Hopkins University School of Medicine, Russell H. Morgan Department of Radiology and Radiological Science, Baltimore, MD (United States)

    2011-10-15

    The purpose of this study was to evaluate the safety and efficacy of CT-guided percutaneous cryoablation for osteoid osteoma in children. This study was approved by the institutional ethics committee. From January 2007 to July 2008, six children (four boys, two girls, mean age 12.6 years old) with osteoid osteoma were treated with CT-guided percutaneous cryoablation. The procedures were carried out under conscious sedation and local anesthesia. CT guidance was used for procedural planning, instrument guidance, and monitoring. An argon-based cryoablation system was used. Each cryoablation included two freezing-thawing cycles. Follow-up was performed to assess technical and clinical outcome for a minimum of 12 months. A visual analog scale (VAS) was used to assess severity of pain pre- and post-procedure, and mean VAS for the group was compared pre- and post-procedure with a t-test. The mean clinical follow-up period was 28.7 months (ranging from 18 to 36 months). Cryoablation was technically and clinically successful for all patients. No major immediate or delayed complications were observed. Significant pain relief (P <0.05) was observed in all patients after operation. Mean VAS were 6.57 {+-} 0.55 pre-procedure and 0.57 {+-} 0.10 1 month post-procedure. Patients were allowed to fully bear their weight and function without limitation within 3 days after the procedure. Pain recurrence was not observed in any patient. Percutaneous cryoablation is safe and effective for the treatment of osteoid osteomas in children. Notably, this procedure can be accomplished without general anesthesia. (orig.)

  1. [Exposure to CT scans in childhood and long-term cancer risk: A review of epidemiological studies].

    Science.gov (United States)

    Baysson, Hélène; Journy, Neige; Roué, Tristan; Ducou-Lepointe, Hubert; Etard, Cécile; Bernier, Marie-Odile

    2016-02-01

    Amongst medical exams requiring ionizing radiation, computed tomography (CT) scans are used more frequently, including in children. These CT examinations are associated with absorbed doses that are much higher than those associated with conventional radiology. In comparison to adults, children have a greater sensitivity to radiation and a longer life span with more years at cancer risks. Five epidemiological studies on cancer risks after CT scan exposure during childhood were published between 2012 and 2015. The results of these studies are consistent and show an increase of cancer risks in children who have been exposed to several CT scans. However, methodological limits due to indication bias, retrospective assessment of radiation exposure from CT scans and lack of statistical power are to be taken into consideration. International projects such as EPI-CT (Epidemiological study to quantify risks for pediatric computerized tomography and to optimize dose), with a focus on dosimetric reconstruction and minimization of bias will provide more precise results. In the meantime, available results reinforce the necessity of justification and optimization of doses.

  2. IL18 and IL18R1 polymorphisms, lung CT and fibrosis: a longitudinal study in coal miners

    Energy Technology Data Exchange (ETDEWEB)

    Nadif, R.; Mintz, M.; Marzec, J.; Jedlicka, A.; Kauffmann, F.; Kleeberger, S.R. [INSERM, U780, Villejuif (France)

    2006-12-15

    It has been suggested that interleukin (IL)-18 plays a role in the development of inflammatory and fibrosing lung diseases. Associations of polymorphisms in the genes coding for IL-18 (108 /G-656T, C-607A, G-137C, T113G, C127T) and its receptor (IL8R1/C-69T) with coal workers' pneumoconiosis (CWP) were studied in 200 miners who were examined in 1990, 1994 and 1999. Coal-dust exposure was assessed according to job history and ambient measures. The main health outcome was lung computed tomography (CT) score in 1990. Internal coherence was assessed by studying CT score in 1994, 4-yr change in CT score and CWP incidence and prevalence. CT score in 1990 was a good predictor of radiographic grade in 1999 and, therefore, an appropriate subclinical quantitative trait. The IL18 -137C allele was associated with lower CT score in 1990 and 1994 (11.24 versus 1.69 and 1.57 versus 2.46, respectively), slower progression of CT score between 1990 and 1994 and lower pneumoconiosis prevalence in 1999 relative to the G allele (0.33 versus 0.77 and 8.2 versus 19.6%, respectively). Smoking- or dust-adjustment, and stratification on IL18R1 genotype and adjustment for haplotype effects did not change the conclusions. In conclusion, the results of the present study suggest a role for IL18 in reducing the development of this fibrosing lung disease.

  3. Computed tomographic characteristics of interval and post screen carcinomas in lung cancer screening

    NARCIS (Netherlands)

    Scholten, E.T.; Horeweg, N.; Koning, H.J. de; Vliegenthart, R.; Oudkerk, M.; Mali, W.P.; Jong, P.A. de

    2015-01-01

    OBJECTIVES: To analyse computed tomography (CT) findings of interval and post-screen carcinomas in lung cancer screening. METHODS: Consecutive interval and post-screen carcinomas from the Dutch-Belgium lung cancer screening trial were included. The prior screening and the diagnostic chest CT were

  4. Computed tomographic characteristics of interval and post screen carcinomas in lung cancer screening

    NARCIS (Netherlands)

    Scholten, Ernst Th.; Horeweg, Nanda; de Koning, Harry J.; Vliegenthart, Rozemarijn; Oudkerk, Matthijs; Mali, Willem P. Th. M.; de Jong, Pim A.

    Objectives To analyse computed tomography (CT) findings of interval and post-screen carcinomas in lung cancer screening. Methods Consecutive interval and post-screen carcinomas from the Dutch-Belgium lung cancer screening trial were included. The prior screening and the diagnostic chest CT were

  5. Computed tomographic characteristics of interval and post screen carcinomas in lung cancer screening

    NARCIS (Netherlands)

    Scholten, E.T.; Horeweg, N.; Koning, H.J. de; Vliegenthart, R.; Oudkerk, M.; Mali, W.P.; Jong, P.A. de

    2015-01-01

    OBJECTIVES: To analyse computed tomography (CT) findings of interval and post-screen carcinomas in lung cancer screening. METHODS: Consecutive interval and post-screen carcinomas from the Dutch-Belgium lung cancer screening trial were included. The prior screening and the diagnostic chest CT were re

  6. Prediction of outcome in patients with suspected acute ischaemic stroke with CT perfusion and CT angiography: the Dutch acute stroke trial (DUST) study protocol

    NARCIS (Netherlands)

    Seeters, T. van; Biessels, G.J.; Schaaf, I.C. van der; Dankbaar, J.W.; Horsch, A.D.; Luitse, M.J.; Niesten, J.M.; Mali, W.P.Th.; Kappelle, L.J.; Graaf, Y. van der; Velthuis, B.K.; Dijk, E.J. van

    2014-01-01

    BACKGROUND: Prediction of clinical outcome in the acute stage of ischaemic stroke can be difficult when based on patient characteristics, clinical findings and on non-contrast CT. CT perfusion and CT angiography may provide additional prognostic information and guide treatment in the early stage. We

  7. Computed Tomography (CT) -- Sinuses

    Medline Plus

    Full Text Available Toggle navigation Test/Treatment Patient Type Screening/Wellness Disease/Condition Safety En Español More Info Images/Videos About Us News Physician ... CT or CAT scan, is a diagnostic medical test that, like traditional x-rays, produces multiple images ...

  8. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available Toggle navigation Test/Treatment Patient Type Screening/Wellness Disease/Condition Safety En Español More Info Images/Videos About Us News Physician ... CT or CAT scan, is a diagnostic medical test that, like traditional x-rays, produces multiple images ...

  9. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available Toggle navigation Test/Treatment Patient Type Screening/Wellness Disease/Condition Safety En Español More Info Images/Videos About Us News Physician ... CT or CAT scan, is a diagnostic medical test that, like traditional x-rays, produces multiple images ...

  10. Computed Tomography (CT) -- Sinuses

    Medline Plus

    Full Text Available Toggle navigation Test/Treatment Patient Type Screening/Wellness Disease/Condition Safety En Español More Info Images/Videos About Us News Physician ... CT or CAT scan, is a diagnostic medical test that, like traditional x-rays, produces multiple images ...

  11. Left and right ventricle assessment with Cardiac CT: validation study vs. Cardiac MR

    Energy Technology Data Exchange (ETDEWEB)

    Maffei, Erica; Seitun, Sara [Giovanni XXIII Hospital, Cardiovascular Radiology Unit, Monastier di Treviso (Italy); Messalli, Giancarlo; Catalano, Onofrio [SDN Foundation - IRCCS, Naples (Italy); Martini, Chiara; Cademartiri, Filippo [Giovanni XXIII Hospital, Cardiovascular Radiology Unit, Monastier di Treviso (Italy); Erasmus Medical Center, Department of Radiology and Cardiology, Rotterdam (Netherlands); Nieman, Koen; Rossi, Alexia; Mollet, Nico R. [Erasmus Medical Center, Department of Radiology and Cardiology, Rotterdam (Netherlands); Guaricci, Andrea I. [Azienda Ospedaliero-Universitaria di Foggia, Department of Cardiology, Foggia (Italy); Tedeschi, Carlo [Ospedale San Gennaro, Department of Cardiology, Naples (Italy)

    2012-05-15

    To compare Magnetic Resonance (MR) and Computed Tomography (CT) for the assessment of left (LV) and right (RV) ventricular functional parameters. Seventy nine patients underwent both Cardiac CT and Cardiac MR. Images were acquired using short axis (SAX) reconstructions for CT and 2D cine b-SSFP (balanced-steady state free precession) SAX sequence for MR, and evaluated using dedicated software. CT and MR images showed good agreement: LV EF (Ejection Fraction) (52 {+-} 14% for CT vs. 52 {+-} 14% for MR; r = 0.73; p > 0.05); RV EF (47 {+-} 12% for CT vs. 47 {+-} 12% for MR; r = 0.74; p > 0.05); LV EDV (End Diastolic Volume) (74 {+-} 21 ml/m{sup 2} for CT vs. 76 {+-} 25 ml/m{sup 2} for MR; r = 0.59; p > 0.05); RV EDV (84 {+-} 25 ml/m{sup 2} for CT vs. 80 {+-} 23 ml/m{sup 2} for MR; r = 0.58; p > 0.05); LV ESV (End Systolic Volume)(37 {+-} 19 ml/m{sup 2} for CT vs. 38 {+-} 23 ml/m{sup 2} for MR; r = 0.76; p > 0.05); RV ESV (46 {+-} 21 ml/m{sup 2} for CT vs. 43 {+-} 18 ml/m{sup 2} for MR; r = 0.70; p > 0.05). Intra- and inter-observer variability were good, and the performance of CT was maintained for different EF subgroups. Cardiac CT provides accurate and reproducible LV and RV volume parameters compared with MR, and can be considered as a reliable alternative for patients who are not suitable to undergo MR. circle Cardiac-CT is able to provide Left and Right Ventricular function. circle Cardiac-CT is accurate as MR for LV and RV volume assessment. (orig.)

  12. Evaluation of CT virtual intravascular endoscopy in fenestrated stent grafts: a preliminary study

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Z. [Dept. of Imaging and Applied Physics, Curtin Univ. of Tech., Perth, WA (Australia); Allen, Y.; Fitzsimmons, B.; Hartely, D. [Cook R and D, WA (Australia); Lawrence-Brown, M. [Dept. of Public Health, Curtin Univ. of Tech., Perth, WA (Australia)

    2007-06-15

    We aim in this study to investigate the potential value of CT virtual intravascular endoscopy in patients diagnosed with abdominal aortic aneurysms undergoing fenestrated stent grafts. Both pre-and post-fenestration (within 3 months of implantation) multislice CT data were collected in eight patients and used for generation of virtual endoscopy images in our preliminary study. Variable fenestrations were deployed in 25 aortic branches with scallop fenestration implanted in six aortic ostia, large fenestration in four aortic ostia and small fenestration in 15 renal ostia, respectively. Measurements of the aortic ostia diameters both pre- and post-fenestration were successfully performed with virtual intravascular endoscopy visualization, and endovascular stents as well as their relationship to the aortic ostia were clearly demonstrated. Our results showed that there was no significant change of diameter of the aortic ostia following fenestrated stem grafts. Endovascular stents were clearly visualized on virtual endoscopy images, and no apparent deformity or malrotation was observed in this small group. Our preliminary study provides new insights into anatomic configuration/dimension of aortic ostia and endovascular stents, and virtual intravascular endoscopy could be a valuable technique to follow-up patients treated with fenestrated stent grafts. (orig.)

  13. SPECT/CT versus MRI in patients with nonspecific pain of the hand and wrist - a pilot study

    Energy Technology Data Exchange (ETDEWEB)

    Huellner, Martin W.; Buerkert, Alexander; Schleich, Florian S.; Strobel, Klaus; Veit-Haibach, Patrick [Lucerne Cantonal Hospital, Department of Radiology and Nuclear Medicine, Lucerne (Switzerland); Schuerch, Maja; Hug, Urs; Wartburg, Urs von [Lucerne Cantonal Hospital, Department of Hand and Plastic Surgery, Lucerne (Switzerland)

    2012-05-15

    Hand and wrist pain is a diagnostic challenge for hand surgeons and radiologists due to the complex anatomy of the involved small structures. The American College of Radiology recommends MRI as the study of choice in patients with chronic wrist pain if radiographs are negative. Lately, state-of-the-art SPECT/CT systems have been introduced and may help in the diagnosis of this selected indication. This retrospective study included 21 patients with nonspecific pain of the hand/wrist. The diagnosis of nonspecific wrist pain was made by the referring hand surgeon based on patient history, clinical examination, plain radiography and clinical guidelines. All patients received planar early-phase imaging and late-phase SPECT/CT imaging as well as MRI. Lesions were divided into major (causative) and minor (not causative) pathologies according to clinical follow-up. Furthermore, oedema-like bone marrow changes seen on MRI were compared with focally increased tracer uptake seen on SPECT/CT images. MRI yielded a quite high sensitivity (0.86), but a low specificity (0.20). In contrast, SPECT/CT yielded a high specificity (1.00) and a low sensitivity (0.71). Oedema-like bone marrow changes were detected in 15 lesions in 11 patients. In ten lesions with bone marrow oedema on MRI, foci of elevated tracer uptake were detected on SPECT/CT. Overall, MRI was more sensitive, but SPECT/CT was more specific in the evaluation of causative pathologies. In this initial comparison, SPECT/CT showed higher specificity than MRI in the evaluation of causative pathologies in patients with nonspecific wrist pain. However, MRI was more sensitive. Thus, SPECT/CT was shown to be a useful problem-solving tool in the diagnostic work-up of these patients. (orig.)

  14. Experimental study of CT test on the failure of acrylate spray-applied waterproof layer in the groundwater environment

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    In this study the computerized tomography (CT) was first used to quantitatively analyze the failure of acrylate spray-applied waterproof membrane in the groundwater environment. The results of the CT tests show that it is feasible to use the CT to quantitatively analyze the failure of the waterproof membrane and the CT method has the advantages of speediness and accuracy that can eliminate the fussy operation process in routine tests. The main conclusions summarized from the study are as follows. First, there are two combined-indexes that can be used to decide the failure of the spray-on waterproof layer: one is that the reduced percentage of the CT number of the spray-on waterproof layer is less than 40.0% and the other is that the variance of the CT number decreases first and then increases. Second, the applicability for the spray-on waterproof layer in the groundwater environment is the SO 24-concentration ≤ 1%, the Cl-concentration ≤ 7.5% and the pH value ≤ 12.0 of the groundwater, respectively.

  15. Performance of systematic and non-systematic ('opportunistic') screening mammography: a comparative study from Denmark

    DEFF Research Database (Denmark)

    Bihrmann, Kristine; Jensen, Allan; Olsen, Anne Helene;

    2008-01-01

    OBJECTIVES: Evaluation and comparison of the performance of organized and opportunistic screening mammography. METHODS: Women attending screening mammography in Denmark in 2000. The study included 37,072 women attending organized screening. Among these, 320 women were diagnosed with breast cancer...

  16. Study of effective dose of various protocols in equipment cone beam CT

    Energy Technology Data Exchange (ETDEWEB)

    Soares, M. R.; Maia, A. F. [Universidade Federale de Sergipe, Departamento de Fisica, Cidade Universitaria Prof. Jose Aloisio de Campos, Marechal Rondon s/n, Jardim Rosa Elze, 49-100000 Sao Cristovao, Sergipe (Brazil); Batista, W. O. [Instituto Federal da Bahia, Rua Emidio dos Santos s/n, Barbalho, Salvador, 40301015 Bahia (Brazil); Caldas, L. V. E.; Lara, P. A., E-mail: mrs2206@gmail.com [Instituto de Pesquisas Energeticas e Nucleares / CNEN, Av. Lineu Prestes 2242, Cidade Universitaria, 05508-000 Sao Paulo (Brazil)

    2014-08-15

    Currently the cone beam computed tomography is widely used in various procedures of dental radiology. Although the doses values associated with the procedures of cone beam CT are low compared to typical values associated with dental radiology procedure in multi slices CT. However can be high compared to typical values of other techniques commonly used in dental radiology. The present scenario is a very wide range of designs of equipment and, consequently, lack of uniformity in all parameters associated with x-ray generation and geometry. In this context, this study aimed to evaluate and calculate the absorbed dose in organs and tissues relevant and estimate effective dose for different protocols with different geometries of exposure in five cone beam CT equipment. For this, a female Alderson anthropomorphic phantom, manufactured by Radiology Support Devices was used. The phantom was irradiated with 26 dosimeters LiF: Mg, Ti (TLD-100), inserted in organs and tissues along the layers forming the head and neck of the phantom. The equipment used, in this present assessment, was: i-CAT Classical, Kodak 9000 3D, Gendex GXCB 500, Sirona Orthophos X G 3D and Planmeca Pro Max 3D. The effective doses were be determined by the ICRP 103 weighting factors. The values were between 7.0 and 111.5 micro Sv, confirming the broad dose range expected due to the diversity of equipment and protocols used in each equipment. The values of effective dose per Fov size were: between 7 and 51.2 micro Sv for located Fov; between 17.6 and 52.0 micro Sv for medium Fov; and between 11.5 and 43.1 micro Sv to large Fov (maxillofacial). In obtaining the effective dose the measurements highlighted a relevance contribution of dose absorbed by the remaining organs (36%), Salivary glands (30%), thyroid (12%) and bone marrow (12%). (Author)

  17. Which Iodine concentration in chest CT? - A prospective study in 300 patients

    Energy Technology Data Exchange (ETDEWEB)

    Muehlenbruch, Georg [RWTH Aachen University Hospital, Department of Diagnostic and Interventional Radiology, Aachen (Germany); University Hospital, RWTH Aachen University, Aachen (Germany); Behrendt, Florian F.; Eddahabi, Mohammed A.; Das, Marco; Guenther, Rolf W.; Mahnken, Andreas H. [RWTH Aachen University Hospital, Department of Diagnostic and Interventional Radiology, Aachen (Germany); Knackstedt, Christian [RWTH Aachen University Hospital, Department of Cardiology, Pulmonology and Angiology, Aachen (Germany); Stanzel, Sven [RWTH Aachen University Hospital, Institute of Medical Statistics, Aachen (Germany); Seidensticker, Peter [Bayer Schering Pharma AG, Berlin (Germany); Wildberger, Joachim E. [University Hospital Maastricht, Department of Radiology, Maastricht (Netherlands)

    2008-12-15

    In computed tomography(CT) several contrast media with different iodine concentrations are available. The aim of this study is to prospectively compare contrast media with iodine concentrations of 300, 370 and 400 mg iodine/ml for chest- CT. 300 consecutive patients were prospectively enrolled, under a waiver of the local ethics committee. The first (second, third) 100 patients, received contrast medium with 300(370, 400)mg iodine/ml. Injection protocols were adapted for an identical iodine delivery rate(1.3 mg/s) and total iodine load(33 g) for all three groups. Standardized MDCT of the chest (16 x 0.75 mm, 120 kVp, 100 mAseff.) was performed. Intravascular attenuation values were measured in the pulmonary trunk and the ascending aorta; subjective image quality was rated on a 3-point-scale. Discomfort during and after injection was evaluated. There were no statistically significant differences in contrast enhancement comparing the three contrast media at the pulmonary trunk(p = 0.3198) and at the ascending aorta(p = 0.0840). Image quality(p = 0.0176) and discomfort during injection(p = 0.7034) were comparable for all groups. General discomfort after injection of contrast media with 300 mg iodine/ml was statistically significant higher compared to 370 mg iodine/ml(p = 0.00019). Given identical iodine delivery rates of 1.3 g/s and iodine loads of 33 g, contrast media with concentrations of 300, 370 and 400 mg iodine/ml do not result in different intravascular enhancement in chest-CT. (orig.)

  18. Anatomic Variation of Sphenoid Sinus and Related Structures in Libyan Population: CT Scan Study

    Directory of Open Access Journals (Sweden)

    Hewaidi GH

    2008-01-01

    Full Text Available Background: Sphenoid sinus is the most inaccessible paranasal sinus, enclosed within the sphenoid bone and intimately related to numerous vital neural and vascular structures. Anatomic variation of the sphenoid sinus is well documented and may complicate surgery in such a place. Objective: To outline the surgically risky anatomic variants of the sphenoid sinus as well as the variable relationships between the sinus and related neurovascular structures, for the safe removal of intrasphenoid and pituitary lesions. Materials and Methods: We undertook a prospective review of 300 paranasal sinus CT scans of Libyan patients; coronal CT scans were obtained by special parameter techniques. We assessed pneumatization of pterygoid process (PP, anterior clinoid process (ACP, and greater wing of sphenoid (GWS; we also examined protrusion and dehiscence of internal carotid artery (ICA, optic nerve (ON, maxillary nerve (MN, and vidian nerve (VN into the sphenoid sinus cavity. Results: Pneumatization of PP, ACP, and GWS were seen in 87 (29%, 46 (15.3%, and 60 patients (20%, respectively. Protrusion of ICA, ON, MN, and VN were noticed in 123 (41%, 107 (35.6%, 73 (24.3%, and 81 patients (27%, respectively; dehiscence of these structures was encountered in 90 (30%, 92 (30.6%, 39 (13%, and 111 patients (37%, respectively. Statistically, there was a highly significant association between ACP pneumatization and ICA protrusion, ACP pneumatization and ON protrusion, PP pneumatization and VN protrusion; and GWS pneumatization and MN protrusion (p-value < 0.001. Conclusion: The sphenoid sinus is highly variable; this variability necessitates a comprehensive understanding of the regional sphenoid sinus anatomy by a detailed CT scan sinus examination before surgery in and around the sinus. This study indicates the possibility of a racial anatomical variation of the sphenoid sinus in the Libyan population.

  19. Sensitivity study of an image processing workflow on synchrotron μ-CT images of Berea sandstone

    Science.gov (United States)

    Leu, Leon; Berg, Steffen; Ott, Holger; Armstrong, Ryan T.; Enzmann, Frieder; Kersten, Michael

    2014-05-01

    For the present study, the sensitivity of the threshold value for watershed-based segmentation and global threshold segmentation was assessed on μ-CT images of fine grained Berea sandstone. The sensitivities were assessed in terms of porosity, permeability, single-phase flow simulations and capillary pressure curves that were calculated from the segmented data. The μ-CT images of fine grained Berea sandstone with a resolution of 3 μm/pixel was segmented using different threshold values that were systematically varied, which resulted in slightly different structures for the pore space. The results show, that watershed-based segmentation is more robust than global threshold segmentation and that the measured permeability showed a stronger sensitivity to threshold variation than porosity, indicating that it is a more sensitive parameter to image segmentation settings. Calculated permeability and capillary pressure curves matched well with experimental data revealing that the average pores and pore throats of the watershed-based segmented structure were segmented accurately. In contrast, capillary pressure curves indicated that pore sizes near the resolution limit of 3 μm, located in kaolinite rich areas of the rock, were not segmented correctly and thus caused the disagreement between the experimental measured porosity and that measured from the digital rock image. We conclude that capillary pressure curves and permeability values that result from the digital rock data is more indicative of the flow relevant fraction of the pore structure and are therefore better suited as validation criterion than porosity data. Numerical modeling of two-phase flow on segmented data from high resolution μ-CT images enhances our understanding of the dynamics of multiphase-flow of immiscible fluids at the pore-scale. To be confident about simulated data it is therefore important to identify meaningful properties, e.g. permeability, that can be used as benchmark parameters for

  20. Cancer screening behaviours among South Asian immigrants in the UK, US and Canada: a scoping study.

    Science.gov (United States)

    Crawford, Joanne; Ahmad, Farah; Beaton, Dorcas; Bierman, Arlene S

    2016-03-01

    South Asian (SA) immigrants settled in the United Kingdom (UK) and North America [United States (US) and Canada] have low screening rates for breast, cervical and colorectal cancers. Incidence rates of these cancers increase among SA immigrants after migration, becoming similar to rates in non-Asian native populations. However, there are disparities in cancer screening, with low cancer screening uptake in this population. We conducted a scoping study using Arksey & O'Malley's framework to examine cancer screening literature on SA immigrants residing in the UK, US and Canada. Eight electronic databases, key journals and reference lists were searched for English language studies and reports. Of 1465 identified references, 70 studies from 1994 to November 2014 were included: 63% on breast or cervical cancer screening or both; 10% examined colorectal cancer screening only; 16% explored health promotion/service provision; 8% studied breast, cervical and colorectal cancer screening; and 3% examined breast and colorectal cancer screening. A thematic analysis uncovered four dominant themes: (i) beliefs and attitudes towards cancer and screening included centrality of family, holistic healthcare, fatalism, screening as unnecessary and emotion-laden perceptions; (ii) lack of knowledge of cancer and screening related to not having heard about cancer and its causes, or lack of awareness of screening, its rationale and/or how to access services; (iii) barriers to access including individual and structural barriers; and (iv) gender differences in screening uptake and their associated factors. Findings offer insights that can be used to develop culturally sensitive interventions to minimise barriers and increase cancer screening uptake in these communities, while recognising the diversity within the SA culture. Further research is required to address the gap in colorectal cancer screening literature to more fully understand SA immigrants' perspectives, as well as research to

  1. Helical CT in the diagnosis of acute lower gastrointestinal haemorrhage

    Energy Technology Data Exchange (ETDEWEB)

    Sabharwal, Rohan [Department of Radiology, Westmead Hospital, Sydney, NSW (Australia); Vladica, Philip [Department of Radiology, Westmead Hospital, Sydney, NSW (Australia)]. E-mail: rpvl@imag.wsahs.nsw.gov.au; Chou, Roger [Department of Radiology, Westmead Hospital, Sydney, NSW (Australia); Law, W. Phillip [Department of Radiology, Westmead Hospital, Sydney, NSW (Australia)

    2006-05-15

    Introduction: A pilot study to evaluate helical computer tomography (CT) as a diagnostic tool for acute lower gastrointestinal tract (GIT) bleeding. CT was compared to conventional angiography (CA) and colonoscopy for the diagnosis and detection of bleeding site in suspected cases of acute lower GIT bleeding. Methods: Seven patients presenting with acute lower GIT bleeding, between June and November 2002, underwent CT examinations. All of these seven patients underwent CA following CT. Emergency colonoscopies were performed on five patients investigated with both CT and CA. Median delay from the most recent episode of hematochezia to CT was two and a half hours, to CA was 3 h, and to colonoscopy was 4 h. None of the patients underwent nuclear medicine (NM) bleeding studies. Results: Haemoglobin drop in all patients was greater than 15 g/L in the first 24 h of presentation. The mean age was 68.86 years (range, 49-83 years). Comparing CT and CA, there were four concordant and three discordant results. Both modalities had concordant findings of two active bleeding sites, one non-bleeding rectal tumour, and one negative case result. In three patients, the source of bleeding was found on CT whereas CA was negative. Emergency colonoscopies performed in all of these three patients confirmed blood in the colon/ileum. Conclusion: Early experience suggests that CT is a safe, convenient and accurate diagnostic tool for acute lower GIT haemorrhage. It raises questions regarding the sensitivity of CA. A new management algorithm for acute lower GIT haemorrhage using CT as the pre-CA screening tool is being proposed based on the preliminary findings. Positive CT will allow directed therapeutic angiography, while negative CT will triage patients into alternative management pathways.

  2. A designed screening study with prespecified combinations of factor settings

    Energy Technology Data Exchange (ETDEWEB)

    Anderson-cook, Christine M [Los Alamos National Laboratory; Robinson, Timothy J [U. WYOMING

    2009-01-01

    In many applications, the experimenter has limited options about what factor combinations can be chosen for a designed study. Consider a screening study for a production process involving five input factors whose levels have been previously established. The goal of the study is to understand the effect of each factor on the response, a variable that is expensive to measure and results in destruction of the part. From an inventory of available parts with known factor values, we wish to identify a best collection of factor combinations with which to estimate the factor effects. Though the observational nature of the study cannot establish a causal relationship involving the response and the factors, the study can increase understanding of the underlying process. The study can also help determine where investment should be made to control input factors during production that will maximally influence the response. Because the factor combinations are observational, the chosen model matrix will be nonorthogonal and will not allow independent estimation of factor effects. In this manuscript we borrow principles from design of experiments to suggest an 'optimal' selection of factor combinations. Specifically, we consider precision of model parameter estimates, the issue of replication, and abilities to detect lack of fit and to estimate two-factor interactions. Through an example, we present strategies for selecting a subset of factor combinations that simultaneously balance multiple objectives, conduct a limited sensitivity analysis, and provide practical guidance for implementing our techniques across a variety of quality engineering disciplines.

  3. Evaluation of cancer service screening: case referent studies recommended.

    NARCIS (Netherlands)

    Verbeek, A.L.M.; Broeders, M.J.M.

    2010-01-01

    Various cancer screening trials, randomised or otherwise controlled, have demonstrated reductions in cancer mortality. As a consequence, population screening programmes have been implemented. In the mean time, major advances are being made in early detection and treatment modalities of specific canc

  4. Hepatic perfusion in a tumor model using DCE-CT: an accuracy and precision study

    Science.gov (United States)

    Stewart, Errol E.; Chen, Xiaogang; Hadway, Jennifer; Lee, Ting-Yim

    2008-08-01

    In the current study we investigate the accuracy and precision of hepatic perfusion measurements based on the Johnson and Wilson model with the adiabatic approximation. VX2 carcinoma cells were implanted into the livers of New Zealand white rabbits. Simultaneous dynamic contrast-enhanced computed tomography (DCE-CT) and radiolabeled microsphere studies were performed under steady-state normo-, hyper- and hypo-capnia. The hepatic arterial blood flows (HABF) obtained using both techniques were compared with ANOVA. The precision was assessed by the coefficient of variation (CV). Under normo-capnia the microsphere HABF were 51.9 ± 4.2, 40.7 ± 4.9 and 99.7 ± 6.0 ml min-1 (100 g)-1 while DCE-CT HABF were 50.0 ± 5.7, 37.1 ± 4.5 and 99.8 ± 6.8 ml min-1 (100 g)-1 in normal tissue, tumor core and rim, respectively. There were no significant differences between HABF measurements obtained with both techniques (P > 0.05). Furthermore, a strong correlation was observed between HABF values from both techniques: slope of 0.92 ± 0.05, intercept of 4.62 ± 2.69 ml min-1 (100 g)-1 and R2 = 0.81 ± 0.05 (P liver diseases.

  5. A Pilot Study on Coupling CT and MRI through Use of Semiconductor Nanoparticles

    CERN Document Server

    Getzin, Matthew; Chuang, Yen-Jun; McCallum, Scott; Cong, Wenxiang; Wang, Chao; Pan, Zhengwei; Dai, Guohao; Wang, Ge

    2014-01-01

    CT and MRI are the two most widely used imaging modalities in healthcare, each with its own merits and drawbacks. Combining these techniques in one machine could provide unprecedented resolution and sensitivity in a single scan, and serve as an ideal platform to explore physical coupling of x-ray excitation and magnetic resonance. Molecular probes such as functionalized nanophosphors present an opportunity to demonstrate a synergy between these modalities. However, a simultaneous CT-MRI scanner does not exist at this moment. As a pilot study, here we propose a mechanism in which water solutions containing LiGa5O8:Cr3+ nanophosphors can be excited with x-rays to store energy, and these excited particles may subsequently influence the T2 relaxation times of the solutions so that a difference in T2 can be measured by MRI before and after x-ray excitation. The trends seen in our study suggest that a measurable effect may exist from x-ray excitation of the nanophosphors. However, there are several experimental con...

  6. Sodium iodoacetate induced osteoarthrosis model in rabbit temporomandibular joint: CT and histological study (part I).

    Science.gov (United States)

    Güler, N; Kürkçü, M; Duygu, G; Cam, B

    2011-11-01

    Studies to elucidate the pathophysiology of osteoarthrosis have been hampered by the lack of a rapid, reproducible animal model that mimics the histopathology and symptoms associated with the disease. The aim of this study is to evaluate the radiological, histological and histomorphometrical findings of four different concentrations of sodium iodoacetate (MIA) to create osteoarthrosis by using an arthrocentesis technique on rabbit temporomandibular joint (TMJ). 12 New Zealand white male rabbits received an injection of MIA (50 μl dose of 1.5, 2, 2.5, 3mg/ml concentrations) to a single joint of each group by arthrocentesis. Computed tomography (CT) images were obtained pre- and post-injections at 2, 4 and 6 weeks. Early osteoarthritic changes in the rabbit TMJ were found histologically at 4 weeks and with a 3mg/ml concentration of MIA. The mean subchondral bone volume depended on the concentration of MIA and was 62±2.6%, 63±4.1%, 42±3.6% and 38±3.8%, respectively. A minor abnormality was found on CT in six joints at the 4-week follow up. MIA injection and arthrocentesis offer a rapid and minimally invasive method of reproducing histologically osteoarthrotic lesions in the rabbit TMJ.

  7. Perfusion analysis using a wide coverage flat-panel volume CT: feasibility study

    Science.gov (United States)

    Grasruck, M.; Gupta, R.; Reichardt, B.; Klotz, E.; Schmidt, B.; Flohr, T.

    2007-03-01

    We developed a Flat-panel detector based Volume CT (VCT) prototype scanner with large z-coverage. In that prototype scanner a Varian 4030CB a-Si flat-panel detector was mounted in a multi slice CT-gantry (Siemens Medical Solutions) which provides a 25 cm field of view with 18 cm z-coverage at isocenter. The large volume covered in one rotation can be used for visualization of complete organs of small animals, e.g. rabbits. By implementing a mode with continuous scanning, we are able to reconstruct the complete volume at any point in time during the propagation of a contrast bolus. Multiple volumetric reconstructions over time elucidate the first pass dynamics of a bolus of contrast resulting in 4-D angiography and potentially allowing whole organ perfusion analysis. We studied to which extent pixel based permeability and blood volume calculation with a modified Patlak approach was possible. Experimental validation was performed by imaging evolution of contrast bolus in New Zealand rabbits. Despite the short circulation time of a rabbit, the temporal resolution was sufficient to visually resolve various phases of the first pass of the contrast bolus. Perfusion imaging required substantial spatial smoothing but allowed a qualitative discrimination of different types of parenchyma in brain and liver. If a true quantitative analysis is possible, requires further studies.

  8. Opportunistic screening for osteoporosis on routine computed tomography? An external validation study

    Energy Technology Data Exchange (ETDEWEB)

    Buckens, Constantinus F. [University Medical Center Utrecht, Department of Radiology, Utrecht (Netherlands); Universitair Medisch Centrum Utrecht, Department of Radiology, Utrecht (Netherlands); Dijkhuis, Gawein; Jong, Pim A. de [University Medical Center Utrecht, Department of Radiology, Utrecht (Netherlands); Keizer, Bart de [University Medical Center Utrecht, Department of Nuclear Medicine, Utrecht (Netherlands); Verhaar, Harald J. [University Medical Center Utrecht, Department of Geriatric Medicine, Utrecht (Netherlands)

    2015-07-15

    Opportunistic screening for osteoporosis using computed tomography (CT) examinations that happen to visualise the spine can be used to identify patients with osteoporosis. We sought to verify the diagnostic performance of vertebral Hounsfield unit (HU) measurements on routine CT examinations for diagnosing osteoporosis in a separate, external population. Consecutive patients who underwent a CT examination of the chest or abdomen and had also received a dual-energy X-ray absorptiometry (DXA) test were retrospectively included. CTs were evaluated for vertebral fractures and vertebral attenuation (density) values were measured. Diagnostic performance measures and the area under the receiver operator characteristics curve (AUC) for diagnosing osteoporosis were calculated. Three hundred and two patients with a mean age of 57.9 years were included, of which 82 (27 %) had osteoporosis according to DXA and 65 (22 %) had vertebral fractures. The diagnostic performance for vertebral HU measurements was modest, with a maximal AUC of 0.74 (0.68 - 0.80). At that optimal threshold the sensitivity was 62 % (51 - 72 %) and the specificity was 79 % (74 - 84 %). We confirmed that simple trabecular vertebral density measurements on routine CT contain diagnostic information related to bone mineral density as measured by DXA, albeit with substantially lower diagnostic accuracy than previously reported. (orig.)

  9. Spondylolysis and spina bifida occulta in pediatric patients: prevalence study using computed tomography as a screening method.

    Science.gov (United States)

    Urrutia, Julio; Cuellar, Jorge; Zamora, Tomas

    2016-02-01

    The prevalence of spondylolysis reported from radiograph-based studies has been questioned in recent computed tomography (CT)-based studies in adults; however, no new data are available in pediatric patients. Spina bifida occulta (SBO), which has been associated to spondylolysis, may be increasing its prevalence, according to recent studies in adults in the last decades, but without new data in pediatric patients. We aimed to determine the prevalence of spondylolysis and SBO in pediatric patients using abdomen and pelvis CT as a screening tool. We studied 228 patients 4-15 years old (107 males), who were evaluated with abdomen and pelvis CT scans for reasons not related to the spine. The entire lumbo-sacral spine was evaluated to detect the presence of spondylolysis and SBO. We compared the prevalence of spondylolysis in patients with and without SBO. A logistic regression analysis was performed to determine the effect of age and sex as independent predictors of spondylolysis and SBO. The prevalence of spondylolysis was 3.5 % (1.1-5.9 %); 2/8 patients presented with olisthesis, both with grade I slip. The prevalence of SBO was 41.2 % (34.8-59.2 %) (94 patients). Spondylolysis was not more frequent in patients with SBO than in patients without SBO. Male sex and decreasing age independently predicted the presence of SBO, but not of spondylolysis. We observed a 3.5 % prevalence of spondylolysis and a 41.2 % prevalence of SBO. SBO was significantly more frequent in males and younger patients.

  10. Role of dynamic CT perfusion study in evaluating various intracranial space-occupying lesions

    Directory of Open Access Journals (Sweden)

    Ravindra B Kamble

    2015-01-01

    Full Text Available Aims: Differentiating intracranial mass lesions on CT scan is challenging. The purpose of our study was to determine the perfusion parameters in various intracranial space-occupying lesions (ICSOL, differentiate benign and malignant lesions, and differentiate between grades of gliomas. Materials and Methods: We performed CT perfusion (CTP in 64 patients, with age ranging from 17 to 68 years, having space-occupying lesions in brain and calculated relative cerebral blood flow (rCBF and relative cerebral blood volume (rCBV. Results: We found significantly lower perfusion in low-grade gliomas as compared to high-grade tumors, lymphoma, and metastases. Similarly in infective lesions, TWT and abscesses showed significantly lower perfusion compared to TOT. In ring enhancing lesions, capsule of TWT showed significantly lower perfusion as compared to abscesses, TOT, and metastases. Conclusion: Thus, in conclusion, infective lesions can be differentiated from tumors like lymphomas, high-grade gliomas, or metastases based on perfusion parameters. The cut off value of rCBV 1.64 can be used to differentiate between low grade and high grade gliomas. However, depending only on perfusion parameters, differentiation between the tumors like lymphomas, high-grade gliomas, and metastases may not be possible.

  11. Intraosseous rotation of the scaphoid: assessment by using a 3D CT model - an anatomic study

    Energy Technology Data Exchange (ETDEWEB)

    Schmidle, Gernot; Gabl, Markus [Medical University Innsbruck, Department of Trauma Surgery, Innsbruck (Austria); Rieger, Michael [Regional Hospital Hall, Department of Radiology, Hall in Tirol (Austria); Klauser, Andrea Sabine; Thauerer, Michael [Medical University Innsbruck, Department of Radiology, Innsbruck (Austria); Hoermann, Romed [Medical University Innsbruck, Department of Anatomy, Histology and Embryology-Division of Clinical and Functional Anatomy, Innsbruck (Austria)

    2014-06-15

    The purpose of this study was to assess intraosseous rotation as the third dimension of scaphoid anatomy on a 3D CT model using common volume rendering software to impact anatomical reconstruction of scaphoid fractures. CT images of 13 cadaver wrist pairs were acquired. Reference axes for the alignment of distal and proximal scaphoid poles were defined three-dimensionally. Two methods for rotation measurement - the reference axis method (RAM) and the scapho-trapezio-trapezoidal joint method (STTM) - were developed and compared by three independent observers. Rotation measured by the RAM averaged 66.9 ± 7 for the right and 67.2 ± 5.8 for the left wrists. Using the STTM there was a mean rotation of 68.6 ± 6.6 for the right and 68.6 ± 6.8 for the left wrists. The overall results showed a significant variability of the measured values between different specimens (P < 0.05). There was no significant difference between left and right wrists of the same specimen, neither for the RAM (P = 0.268) nor for the STTM (P = 0.774). Repeatability coefficients between the observers were low, indicating good repeatability. The presented methods are practical tools to quantify intraosseous rotation between distal and proximal scaphoid poles using common volume rendering software. For clinical application the opposite side provides the best reference values to assess malrotation in scaphoid fracture cases. (orig.)

  12. Quantifying the impact of respiratory-gated 4D CT acquisition on thoracic image quality: A digital phantom study

    Energy Technology Data Exchange (ETDEWEB)

    Bernatowicz, K., E-mail: kingab@student.ethz.ch; Knopf, A.; Lomax, A. [Center for Proton Therapy, Paul Scherrer Institute, Villigen PSI 5232, Switzerland and Department of Physics, ETH Zürich, Zürich 8092 (Switzerland); Keall, P.; Kipritidis, J., E-mail: john.kipritidis@sydney.edu.au [Radiation Physics Laboratory, Sydney Medical School, University of Sydney, Sydney, NSW 2006 (Australia); Mishra, P. [Brigham and Womens Hospital, Dana-Farber Cancer Institute and Harvard Medical School, Boston, Massachusetts 02115 (United States)

    2015-01-15

    Purpose: Prospective respiratory-gated 4D CT has been shown to reduce tumor image artifacts by up to 50% compared to conventional 4D CT. However, to date no studies have quantified the impact of gated 4D CT on normal lung tissue imaging, which is important in performing dose calculations based on accurate estimates of lung volume and structure. To determine the impact of gated 4D CT on thoracic image quality, the authors developed a novel simulation framework incorporating a realistic deformable digital phantom driven by patient tumor motion patterns. Based on this framework, the authors test the hypothesis that respiratory-gated 4D CT can significantly reduce lung imaging artifacts. Methods: Our simulation framework synchronizes the 4D extended cardiac torso (XCAT) phantom with tumor motion data in a quasi real-time fashion, allowing simulation of three 4D CT acquisition modes featuring different levels of respiratory feedback: (i) “conventional” 4D CT that uses a constant imaging and couch-shift frequency, (ii) “beam paused” 4D CT that interrupts imaging to avoid oversampling at a given couch position and respiratory phase, and (iii) “respiratory-gated” 4D CT that triggers acquisition only when the respiratory motion fulfills phase-specific displacement gating windows based on prescan breathing data. Our framework generates a set of ground truth comparators, representing the average XCAT anatomy during beam-on for each of ten respiratory phase bins. Based on this framework, the authors simulated conventional, beam-paused, and respiratory-gated 4D CT images using tumor motion patterns from seven lung cancer patients across 13 treatment fractions, with a simulated 5.5 cm{sup 3} spherical lesion. Normal lung tissue image quality was quantified by comparing simulated and ground truth images in terms of overall mean square error (MSE) intensity difference, threshold-based lung volume error, and fractional false positive/false negative rates. Results

  13. In Vivo RNAi-Based Screens: Studies in Model Organisms

    Directory of Open Access Journals (Sweden)

    Miki Yamamoto-Hino

    2013-11-01

    Full Text Available RNA interference (RNAi is a technique widely used for gene silencing in organisms and cultured cells, and depends on sequence homology between double-stranded RNA (dsRNA and target mRNA molecules. Numerous cell-based genome-wide screens have successfully identified novel genes involved in various biological processes, including signal transduction, cell viability/death, and cell morphology. However, cell-based screens cannot address cellular processes such as development, behavior, and immunity. Drosophila and Caenorhabditis elegans are two model organisms whose whole bodies and individual body parts have been subjected to RNAi-based genome-wide screening. Moreover, Drosophila RNAi allows the manipulation of gene function in a spatiotemporal manner when it is implemented using the Gal4/UAS system. Using this inducible RNAi technique, various large-scale screens have been performed in Drosophila, demonstrating that the method is straightforward and valuable. However, accumulated results reveal that the results of RNAi-based screens have relatively high levels of error, such as false positives and negatives. Here, we review in vivo RNAi screens in Drosophila and the methods that could be used to remove ambiguity from screening results.

  14. Comparative imaging study in ultrasound, MRI, CT, and DSA using a multimodality renal artery phantom

    Energy Technology Data Exchange (ETDEWEB)

    King, Deirdre M.; Fagan, Andrew J.; Moran, Carmel M.; Browne, Jacinta E. [Medical Ultrasound Physics and Technology Group, School of Physics, Dublin Institute of Technology, Dublin 8 (Ireland); Centre for Advanced Medical Imaging (CAMI), St James' s Hospital, Dublin 8 (Ireland); Department of Medical Physics, University of Edinburgh, Edinburgh EH16 4TJ (United Kingdom); Medical Ultrasound Physics and Technology Group, School of Physics, Dublin Institute of Technology, Dublin 8 (Ireland)

    2011-02-15

    Purpose: A range of anatomically realistic multimodality renal artery phantoms consisting of vessels with varying degrees of stenosis was developed and evaluated using four imaging techniques currently used to detect renal artery stenosis (RAS). The spatial resolution required to visualize vascular geometry and the velocity detection performance required to adequately characterize blood flow in patients suffering from RAS are currently ill-defined, with the result that no one imaging modality has emerged as a gold standard technique for screening for this disease. Methods: The phantoms, which contained a range of stenosis values (0%, 30%, 50%, 70%, and 85%), were designed for use with ultrasound, magnetic resonance imaging, x-ray computed tomography, and x-ray digital subtraction angiography. The construction materials used were optimized with respect to their ultrasonic speed of sound and attenuation coefficient, MR relaxometry (T{sub 1},T{sub 2}) properties, and Hounsfield number/x-ray attenuation coefficient, with a design capable of tolerating high-pressure pulsatile flow. Fiducial targets, incorporated into the phantoms to allow for registration of images among modalities, were chosen to minimize geometric distortions. Results: High quality distortion-free images of the phantoms with good contrast between vessel lumen, fiducial markers, and background tissue to visualize all stenoses were obtained with each modality. Quantitative assessments of the grade of stenosis revealed significant discrepancies between modalities, with each underestimating the stenosis severity for the higher-stenosed phantoms (70% and 85%) by up to 14%, with the greatest discrepancy attributable to DSA. Conclusions: The design and construction of a range of anatomically realistic renal artery phantoms containing varying degrees of stenosis is described. Images obtained using the main four diagnostic techniques used to detect RAS were free from artifacts and exhibited adequate contrast

  15. Predictive Accuracy of the PanCan Lung Cancer Risk Prediction Model -External Validation based on CT from the Danish Lung Cancer Screening Trial

    DEFF Research Database (Denmark)

    Winkler Wille, Mathilde M.; van Riel, Sarah J.; Saghir, Zaigham

    2015-01-01

    ; in fact opposing effects of sex were observed in the two cohorts. Thus, female sex appeared to lower the risk (p = 0.047 and p = 0.040) in the DLCST. Conclusions: High risk discrimination was validated in the DLCST cohort, mainly determined by nodule size. Age and family history of lung cancer were......Objectives: Lung cancer risk models should be externally validated to test generalizability and clinical usefulness. The Danish Lung Cancer Screening Trial (DLCST) is a population-based prospective cohort study, used to assess the discriminative performances of the PanCan models. Methods: From...... used to evaluate risk discrimination. Results: AUCs of 0.826–0.870 were found for DLCST data based on PanCan risk prediction models. In the DLCST, age and family history were significant predictors (p = 0.001 and p = 0.013). Female sex was not confirmed to be associated with higher risk of lung cancer...

  16. Preliminary study on CT perfusion imaging in guiding biopsy of pulmonary lumps

    Institute of Scientific and Technical Information of China (English)

    KANG Li-qing; SONG Zhao-wei; LI Zhong-xin; YU Shu-jing; LIU Feng-hai; CHEN Yue-feng; XING Rong-ge

    2009-01-01

    Background CT perfusion imaging (CTP) has been proved to be a powerful functional imaging technique.This study aimed to evaluate the value of CTP in guiding biopsy of pulmonary lumps.Methods A total of 147 patients with pulmonary lumps who had CT guided biopsies were enrolled in this study from February 2005 to June 2007.The patients were assigned to 3 groups:33 cases guided by CTP as group Ⅰ,45 cases guided by contrast-enhanced scan of CT as group Ⅱ,and 69 cases guided by plain scan of CT as group Ⅲ.Each group was subdivided into central and peripheral types according to the location of the lumps.The achievement ratio of biopsy,the accuracy in grouping,and grading of lung cancer,and the incidence of complication were compared.Results The total achievement ratios of biopsy from group Ⅰ to Ⅲ were 100% (33/33),91% (41/45),and 80% (55/69)respectively,and the difference was statistically significant between group Ⅰ and Ⅲ (P <0.05).For the central type,they were 100% (18/18),88% (15/17),and 79% (11/14) respectively,and the difference was also statistically significant between group Ⅰ and Ⅲ (P <0.05).For the peripheral type,they were 100% (15/15),93% (26/28),and 80% (44/55) espectivelies,and the difference was not statistically significant among the three groups.The total accuracies in grouping and grading of lung cancer from group Ⅰ to Ⅲ were 100% (27/27),91% (31/34),and 72% (33/46) respectively,and the difference was statistically significant between group Ⅰ and Ⅲ and between group Ⅱ and III (P <0.05).For the central type,they were 100% (16/16),94% (16/17),and 70% (8/12) respectively,and the difference was statistically significant between group Ⅰ and Ⅲ (P <0.05).For the peripheral type,they were 100% (11/11),88% (15/17),and 72%(26/36) respectively,and the difference was statistically significant between group Ⅰ and Ⅲ (P <0.05).The total incidence of complication from group Ⅰ to Ⅲ were 15% (5/33),27% (12/45),and 43% (30

  17. Volumetric gain of the human pancreas after left partial pancreatic resection: A CT-scan based retrospective study.

    Science.gov (United States)

    Phillip, Veit; Zahel, Tina; Danninger, Assiye; Erkan, Mert; Dobritz, Martin; Steiner, Jörg M; Kleeff, Jörg; Schmid, Roland M; Algül, Hana

    2015-01-01

    Regeneration of the pancreas has been well characterized in animal models. However, there are conflicting data on the regenerative capacity of the human pancreas. The aim of the present study was to assess the regenerative capacity of the human pancreas. In a retrospective study, data from patients undergoing left partial pancreatic resection at a single center were eligible for inclusion (n = 185). Volumetry was performed based on 5 mm CT-scans acquired through a 256-slice CT-scanner using a semi-automated software. Data from 24 patients (15 males/9 females) were included. Mean ± SD age was 68 ± 11 years (range, 40-85 years). Median time between surgery and the 1st postoperative CT was 9 days (range, 0-27 days; IQR, 7-13), 55 days (range, 21-141 days; IQR, 34-105) until the 2nd CT, and 191 days (range, 62-1902; IQR, 156-347) until the 3rd CT. The pancreatic volumes differed significantly between the first and the second postoperative CT scans (median volume 25.6 mL and 30.6 mL, respectively; p = 0.008) and had significantly increased further by the 3rd CT scan (median volume 37.9 mL; p = 0.001 for comparison with 1st CT scan and p = 0.003 for comparison with 2nd CT scan). The human pancreas shows a measurable and considerable potential of volumetric gain after partial resection. Multidetector-CT based semi-automated volume analysis is a feasible method for follow-up of the volume of the remaining pancreatic parenchyma after partial pancreatectomy. Effects on exocrine and endocrine pancreatic function have to be evaluated in a prospective manner. Copyright © 2015 IAP and EPC. Published by Elsevier B.V. All rights reserved.

  18. Factors influencing young men's decision to undergo health screening in Malaysia: a qualitative study

    Science.gov (United States)

    Teo, Chin Hai; Ng, Chirk Jenn; White, Alan

    2017-01-01

    Objectives Uptake of health screening is low in men, particularly among those aged purposively sampled according to their ethnicity, job position, age and screening status in order to achieve maximal variation. Results Eight IDIs and five FGDs were conducted (n=31) and six themes emerged from the analysis. (1) Young men did not consider screening as part of prevention and had low risk perception. (2) The younger generation was more receptive to health screening due to their exposure to health information through the internet. (3) Health screening was not a priority in young men except for those who were married. (4) Young men had limited income and would rather invest in health insurance than screening. (5) Young men tended to follow doctors' advice when it comes to screening and preferred doctors of the same gender and ethnicity. (6) Medical overuse was also raised where young men wanted more screening tests while doctors tended to promote unnecessary screening tests to them. Conclusions This study identified important factors that influenced young men's screening behaviour. Health authorities should address young men's misperceptions, promote the importance of early detection and develop a reasonable health screening strategy for them. Appropriate measures must be put in place to reduce low value screening practices. PMID:28283491

  19. Flat panel CT following stapes prosthesis insertion: an experimental and clinical study

    Energy Technology Data Exchange (ETDEWEB)

    Zaoui, K. [University-Hospital Heidelberg, Ludwig-Karls-University Heidelberg, Department of Otorhinolaryngology, Head and Neck Surgery, Heidelberg (Germany); Kromeier, J. [St.-Josefs-Hospital, RkK, Department of Radiology, Freiburg (Germany); Neudert, M.; Zahnert, T. [University-Hospital Dresden, Technical-University Dresden, Department of Otorhinolaryngology, Head and Neck Surgery, Dresden (Germany); Boedeker, C.C.; Laszig, R.; Offergeld, C. [University-Hospital Freiburg, Albert-Ludwigs-University Freiburg, Department of Otorhinolaryngology, Head and Neck Surgery, Freiburg (Germany)

    2012-04-15

    Anatomical information of the middle and inner ear is becoming increasingly important in post-operative evaluation especially after stapesplasty with unsuccessful improvement of the air-bone gap (ABG). So far computed tomography (CT) has been the first choice for detection of reasons for recurrent hearing loss. CT has the disadvantage of metal-induced artefacts after insertion of middle ear implants and of a relatively high irradiation dose. Flat panel CT (fpCT) was performed in three temporal bone specimen after experimental insertion of different stapes prostheses, aiming to validate the accuracy of fpCT of the middle and inner ear. Additionally, 28 consecutive patients, supplied with different stapes prostheses underwent post-operative fpCT to compare the pre- and post-operative hearing results with the determined prosthesis position in the middle and inner ear. In all cases, fpCT showed a statistically significant correlation between hearing improvement and prosthesis position. This technique provided detailed post-operative information of the implant position in patients and temporal bone specimen. The new imaging technique of fpCT allows the immediate and almost artefact-free evaluation of surgical results following stapesplasty. Further benefits are a lower irradiation dose and higher isovolumetric resolution compared with standard CT. (orig.)

  20. Multidetector-row CT duodenography in familial adenomatous polyposis: a pilot study

    Energy Technology Data Exchange (ETDEWEB)

    Taylor, S.A.; Halligan, S. E-mail: s.halligan@imperial.ac.uk; Moore, L.; Saunders, B.P.; Gallagher, M.; Phillips, R.K.S.; Bartram, C.I

    2004-10-01

    AIM: To investigate the feasibility of using multidetector-row computed tomography (CT) duodenography to stage duodenal polyposis in patients with familial adenomatous polyposis. MATERIALS AND METHODS: Six patients underwent multidetector-row CT duodenography before upper gastrointestinal endoscopy. A single-blinded radiologist used a surface shaded three-dimensional endoluminal fly though and two-dimensional axial and multiplanar reformats to assign a score for maximum polyp size and number based on the Spigelman classification. Comparison was made with the corresponding Spigelman scores obtained from subsequent endoscopy. RESULTS: CT duodenography was technically successful in five of six patients. The CT derived Spigelman score based on maximum polyp size was accurate in all five patients. The CT derived Spigelman score based on polyp number was accurate in only two cases: Polyp number was overestimated in one patient and underestimated in a further two. In retrospect, fine carpeting of tiny duodenal polyps was poorly visualized with CT. CONCLUSIONS: CT duodenography is technically feasible and accurately predicts maximum polyp size but CT estimates of polyp number are relatively inaccurate. CT duodenography potentially has a useful role for duodenal surveillance in those patients intolerant of conventional endoscopy.

  1. A Study on Knowledge and Screening for Cervical Cancer among ...

    African Journals Online (AJOL)

    More than three-fourth of these patients are diagnosed in advanced ... Knowledge about cervical cancer, its screening among women. • Role of ... doctors earlier, they were neither educated about cervical cancer nor were they told about.

  2. Studies on antibacterial screening of corm of Amorphophallus campanulatus (Roxb.

    Directory of Open Access Journals (Sweden)

    Bhagwan Mariba Waghmare

    2017-05-01

    Full Text Available Objective: To study the antibacterial screening of corm of Amorphophallus campanulatus (Roxb. (A. campanulatus. Methods: Antibacterial activities of methanolic, petroleum ether and ethyl acetate extracts of corm of A. campanulatus were studied by agar diffusion technique to determine in vitro antibacterial activities. The antibacterial activity was measured with respect to the standard antibacterial drug. In addition, minimum inhibitory concentration was also determined by using serial dilution method to determine and evaluate antibacterial potency of test corm extracts of A. campanulatus. Results: The results showed significant antibacterial activities against four pathogenic bacteria. The minimum inhibitory concentration values against test bacteria were found to be remarkable range in bacteria like methicillin-resistant Staphylococcus aureus at concentration 0.25 mg/ well, in Pseudomonas aeruginosa at 0.5 mg/well concentration, in Vibrio cholerae was 2 mg/ well, Streptococcus pyogenes at concentration of 0.5 mg/well and Proteus mirabilis was at concentration of 2 mg/well. Conclusions: The methanolic and petroleum ether extracts are capable to maximum inhibition of the tested pathogenic bacteria.

  3. Use of CT scanning for the study of posterior lumbar intervertebral articulations

    Energy Technology Data Exchange (ETDEWEB)

    Hermanus, N.; de Becker, D.; Baleriaux, D.; Hauzeur, J.P.

    1983-01-01

    CT scan is peculiarly effective in the study of architectural pathologies of the column; it appears that a number of etiological factors of low back pain are involved and they are often related. Indeed, dis herniation, for instance, is frequently associated with facetal asymmetry, the first signs of arthroses and ligamentous calcification after treatment. The three vertebral axes must be evaluated, one discal and two facetal, the slightest defect in one of which can affect the two others. Moreover, in view of the complexity of the innervation, the entire lumbar column from L1 to L5 S1 must be investigated: it is not uncommonly that low sciatica is caused by a more cranial lumbar pathology. This systematic study promotes better understanding of the etiology of low back pain and suggests a stet judicious therapeutic attitude.

  4. Factors influencing the robustness of P-value measurements in CT texture prognosis studies

    Science.gov (United States)

    McQuaid, Sarah; Scuffham, James; Alobaidli, Sheaka; Prakash, Vineet; Ezhil, Veni; Nisbet, Andrew; South, Christopher; Evans, Philip

    2017-07-01

    Several studies have recently reported on the value of CT texture analysis in predicting survival, although the topic remains controversial, with further validation needed in order to consolidate the evidence base. The aim of this study was to investigate the effect of varying the input parameters in the Kaplan-Meier analysis, to determine whether the resulting P-value can be considered to be a robust indicator of the parameter’s prognostic potential. A retrospective analysis of the CT-based normalised entropy of 51 patients with lung cancer was performed and overall survival data for these patients were collected. A normalised entropy cut-off was chosen to split the patient cohort into two groups and log-rank testing was performed to assess the survival difference of the two groups. This was repeated for varying normalised entropy cut-offs and varying follow-up periods. Our findings were also compared with previously published results to assess robustness of this parameter in a multi-centre patient cohort. The P-value was found to be highly sensitive to the choice of cut-off value, with small changes in cut-off producing substantial changes in P. The P-value was also sensitive to follow-up period, with particularly noisy results at short follow-up periods. Using matched conditions to previously published results, a P-value of 0.162 was obtained. Survival analysis results can be highly sensitive to the choice in texture cut-off value in dichotomising patients, which should be taken into account when performing such studies to avoid reporting false positive results. Short follow-up periods also produce unstable results and should therefore be avoided to ensure the results produced are reproducible. Previously published findings that indicated the prognostic value of normalised entropy were not replicated here, but further studies with larger patient numbers would be required to determine the cause of the different outcomes.

  5. A qualitative study exploring why individuals opt out of lung cancer screening.

    Science.gov (United States)

    Carter-Harris, Lisa; Brandzel, Susan; Wernli, Karen J; Roth, Joshua A; Buist, Diana S M

    2017-04-01

    Lung cancer screening with annual low-dose computed tomography is relatively new for long-term smokers in the USA supported by a US Preventive Services Task Force Grade B recommendation. As screening programs are more widely implemented nationally and providers engage patients about lung cancer screening, it is critical to understand behaviour among high-risk smokers who opt out to improve shared decision-making processes for lung cancer screening. The purpose of this study was to explore the reasons for screening-eligible patients' decisions to opt out of screening after receiving a provider recommendation. Semi-structured qualitative telephone interviews were performed with 18 participants who met lung cancer screening criteria for age, smoking and pack-year history in Washington State from November 2015 to January 2016. Two researchers with cancer screening and qualitative methodology expertise conducted data analysis using thematic content analytic procedures from audio-recorded interviews. Five primary themes emerged for reasons of opting out of lung cancer screening: (i) Knowledge Avoidance; (ii) Perceived Low Value; (iii) False-Positive Worry; (iv) Practical Barriers; and (v) Patient Misunderstanding. The participants in our study provided insight into why some patients make the decision to opt out of low-dose computed tomography screening, which provides knowledge that can inform intervention development to enhance shared decision-making processes between long-term smokers and their providers and decrease decisional conflict about screening.

  6. Are CT Scans a Satisfactory Substitute for the Follow-Up of RSA Migration Studies of Uncemented Cups? A Comparison of RSA Double Examinations and CT Datasets of 46 Total Hip Arthroplasties

    Directory of Open Access Journals (Sweden)

    Volker Otten

    2017-01-01

    Full Text Available As part of the 14-year follow-up of a prospectively randomized radiostereometry (RSA study on uncemented cup fixation, two pairs of stereo radiographs and a CT scan of 46 hips were compared. Tantalum beads, inserted during the primary operation, were detected in the CT volume and the stereo radiographs and used to produce datasets of 3D coordinates. The limit of agreement between the combined CT and RSA datasets was calculated in the same way as the precision of the double RSA examination. The precision of RSA corresponding to the 99% confidence interval was 1.36°, 1.36°, and 0.60° for X-, Y-, and Z-rotation and 0.40, 0.17, and 0.37 mm for X-, Y-, and Z-translation. The limit of agreement between CT and RSA was 1.51°, 2.17°, and 1.05° for rotation and 0.59, 0.56, and 0.74 mm for translation. The differences between CT and RSA are close to the described normal 99% confidence interval for precision in RSA: 0.3° to 2° for rotation and 0.15 to 0.6 mm for translation. We conclude that measurements using CT and RSA are comparable and that CT can be used for migration studies for longitudinal evaluations of patients with RSA markers.

  7. External validation of the New Orleans Criteria (NOC), the Canadian CT Head Rule (CCHR) and the National Emergency X-Radiography Utilization Study II (NEXUS II) for CT scanning in pediatric patients with minor head injury in a non-trauma center

    Energy Technology Data Exchange (ETDEWEB)

    Schachar, Jennifer L. [Albert Einstein College of Medicine, Department of Radiology, Bronx, NY (United States); Zampolin, Richard L.; Miller, Todd S.; Farinhas, Joaquim M.; Taragin, Benjamin H. [Albert Einstein College of Medicine and Montefiore Medical Center, Department of Radiology, Bronx, NY (United States); Freeman, Katherine [Albert Einstein College of Medicine and Montefiore Medical Center, Department of Biostatistics, Bronx, NY (United States)

    2011-08-15

    Head CT scans are considered the imaging modality of choice to screen patients with head trauma for neurocranial injuries; however, widespread CT imaging is not recommended and much research has been conducted to establish objective clinical predictors of intracranial injury (ICI) in order to optimize the use of neuroimaging in children with minor head trauma. To evaluate whether a strict application of the New Orleans Criteria (NOC), Canadian CT Head Rule (CCHR) and National Emergency X-Radiography Utilization Study II (NEXUS II) in pediatric patients with head trauma presenting to a non-trauma center (level II) could reduce the number of cranial CT scans performed without missing clinically significant ICI. We conducted an IRB-approved retrospective analysis of pediatric patients with head trauma who received a cranial CT scan between Jan. 1, 2001, and Sept. 1, 2008, and identified which patients would have required a scan based on the criteria of the above listed decision instruments. We then determined the sensitivities, specificities and negative predictive values of these aids. In our cohort of 2,101 patients, 92 (4.4%) had positive head CT findings. The sensitivities for the NOC, CCHR and NEXUS II were 96.7% (95%CI 93.1-100), 65.2% (95%CI 55.5-74.9) and 78.3% (95%CI 69.9-86.7), respectively, and their negative predictive values were 98.7%, 97.6% and 97.2%, respectively. In contrast, the specificities for these aids were 11.2% (95%CI 9.8-12.6), 64.2% (95%CI 62.1-66.3) and 34.2% (95%CI 32.1-36.3), respectively. Therefore, in our population it would have been possible to scan at least 10.9% fewer patients. The number of cranial CT scans conducted in our pediatric cohort with head trauma would have been reduced had any of the three clinical decision aids been applied. Therefore, we recommend that further validation and adoption of pediatric head CT decision aids in non-trauma centers be considered to ultimately increase patient safety while reducing medical

  8. Evaluation of Deep Vein Thrombosis with Multidetector Row CT after Orthopedic Arthroplasty: a Prospective Study for Comparison with Doppler Sonography

    Energy Technology Data Exchange (ETDEWEB)

    Byun, Sung Su; Kim, Youn Jeong; Chun, Yong Sun; Kim, Won Hong [Inha University, College of Medicine, Incheon (Korea, Republic of); Kim, Jeong Ho; Park, Chul Hi [Gachon University, Gil Medical Center, Incheon (Korea, Republic of)

    2008-02-15

    This prospective study evaluated the ability of indirect 16-row multidetector CT venography, in comparison with Doppler sonography, to detect deep vein thrombosis after total hip or knee replacement. Sixty-two patients had undergone orthopedic replacement surgery on a total of 30 hip joints and 54 knee joints. The CT venography (scan delay time: 180 seconds; slice thickness/increment: 2/1.5 mm) and Doppler sonography were performed 8 to 40 days after surgery. We measured the z-axis length of the beam hardening artifact that degraded the image quality so that the presence of deep vein thrombosis couldn't be evaluated on the axial CT images. The incidence and location of deep vein thrombosis was analyzed. The diagnostic performance of the CT venograms was evaluated and compared with that of Doppler sonography as a standard of reference. The z-axis length (mean{+-}standard deviation) of the beam hardening artifact was 4.5{+-}0.8 cm in the arthroplastic knees and 3.9{+-}2.9 cm in the arthroplastic hips. Deep vein thrombosis (DVT) was found in the popliteal or calf veins on Doppler sonography in 30 (48%) of the 62 patients. The CT venography has a sensitivity, specificity, positive predictive value, negative predictive value and accuracy of 90%, 97%, 96%, 91% and 94%, respectively. The ability of CT venography to detect DVT was comparable to that of Doppler sonography despite of beam hardening artifact. Therefore, CT venography is feasible to use as an alternative modality for evaluating postarthroplasty patients.

  9. Predictive value of low tube voltage and dual-energy CT for successful shock wave lithotripsy: an in vitro study.

    Science.gov (United States)

    Largo, Remo; Stolzmann, Paul; Fankhauser, Christian D; Poyet, Cédric; Wolfsgruber, Pirmin; Sulser, Tullio; Alkadhi, Hatem; Winklhofer, Sebastian

    2016-06-01

    This study investigates the capabilities of low tube voltage computed tomography (CT) and dual-energy CT (DECT) for predicting successful shock wave lithotripsy (SWL) of urinary stones in vitro. A total of 33 urinary calculi (six different chemical compositions; mean size 6 ± 3 mm) were scanned using a dual-source CT machine with single- (120 kVp) and dual-energy settings (80/150, 100/150 Sn kVp) resulting in six different datasets. The attenuation (Hounsfield Units) of calculi was measured on single-energy CT images and the dual-energy indices (DEIs) were calculated from DECT acquisitions. Calculi underwent SWL and the number of shock waves for successful disintegration was recorded. The prediction of required shock waves regarding stone attenuation/DEI was calculated using regression analysis (adjusted for stone size and composition) and the correlation between CT attenuation/DEI and the number of shock waves was assessed for all datasets. The median number of shock waves for successful stone disintegration was 72 (interquartile range 30-361). CT attenuation/DEI of stones was a significant, independent predictor (P waves with the best prediction at 80 kVp (β estimate 0.576) (P waves ranged between ρ = 0.31 and 0.68 showing the best correlation at 80 kVp (P < 0.001). The attenuation of urinary stones at low tube voltage CT is the best predictor for successful stone disintegration, being independent of stone composition and size. DECT shows no added value for predicting the success of SWL.

  10. {sup 18}F-Fluorocholine PET/CT for localization of hyperfunctioning parathyroid tissue in primary hyperparathyroidism: a pilot study

    Energy Technology Data Exchange (ETDEWEB)

    Lezaic, Luka; Rep, Sebastijan; Fettich, Jure [University Medical Centre Ljubljana, Department for Nuclear Medicine, Ljubljana (Slovenia); Sever, Mojca Jensterle; Kocjan, Tomaz [University Medical Centre Ljubljana, Department of Endocrinology, Diabetes and Metabolic Diseases, Ljubljana (Slovenia); Hocevar, Marko [Institute of Oncology, Department of Surgical Oncology, Ljubljana (Slovenia)

    2014-11-15

    Primary hyperparathyroidism is a common endocrine disorder which is diagnosed biochemically and for which therapy is surgical. A prerequisite for minimally invasive surgery, which minimizes morbidity and cost, is accurate localization of the involved gland(s). The aim of this study was to evaluate the usefulness of {sup 18}F-fluorocholine PET/CT for preoperative localization of hyperfunctioning parathyroid tissue. {sup 18}F-Fluorocholine PET/CT and conventional parathyroid scintigraphic imaging consisting of {sup 99m}Tc-sestaMIBI SPECT/CT, {sup 99m}Tc-sestaMIBI dual-phase imaging and {sup 99m}Tc-sestaMIBI/pertechnetate subtraction imaging were performed in 24 patients. The diagnostic performance of the imaging methods was compared against histology as the gold standard and postoperative serum Ca{sup 2+} and iPTH values. The sensitivity and specificity of {sup 18}F-fluorocholine PET/CT were 92 % and 100 %, respectively, in contrast to 49 % and 100 %, 46 % and 100 %, and 44 % and 100 % for {sup 99m}Tc-sestaMIBI SPECT/CT, {sup 99m}Tc-sestaMIBI/pertechnetate subtraction imaging and {sup 99m}Tc-sestaMIBI dual-phase imaging, respectively. Combined conventional scintigraphic imaging had a sensitivity and specificity of 64 % and 100 %, respectively. The performance of {sup 18}F-fluorocholine PET/CT was superior particularly in patients with multiple lesions or hyperplasia. {sup 18}F-Fluorocholine PET/CT appears to be a promising, effective imaging method for localization of hyperfunctioning parathyroid tissue. (orig.)

  11. PET/CT-guided treatment planning for paediatric cancer patients: a simulation study of proton and conventional photon therapy

    Science.gov (United States)

    Brodin, N P; Björk-Eriksson, T; Birk Christensen, C; Kiil-Berthelsen, A; Aznar, M C; Hollensen, C; Markova, E; Munck af Rosenschöld, P

    2015-01-01

    Objective: To investigate the impact of including fluorine-18 fludeoxyglucose (18F-FDG) positron emission tomography (PET) scanning in the planning of paediatric radiotherapy (RT). Methods: Target volumes were first delineated without and subsequently re-delineated with access to 18F-FDG PET scan information, on duplicate CT sets. RT plans were generated for three-dimensional conformal photon RT (3DCRT) and intensity-modulated proton therapy (IMPT). The results were evaluated by comparison of target volumes, target dose coverage parameters, normal tissue complication probability (NTCP) and estimated risk of secondary cancer (SC). Results: Considerable deviations between CT- and PET/CT-guided target volumes were seen in 3 out of the 11 patients studied. However, averaging over the whole cohort, CT or PET/CT guidance introduced no significant difference in the shape or size of the target volumes, target dose coverage, irradiated volumes, estimated NTCP or SC risk, neither for IMPT nor 3DCRT. Conclusion: Our results imply that the inclusion of PET/CT scans in the RT planning process could have considerable impact for individual patients. There were no general trends of increasing or decreasing irradiated volumes, suggesting that the long-term morbidity of RT in childhood would on average remain largely unaffected. Advances in knowledge: 18F-FDG PET-based RT planning does not systematically change NTCP or SC risk for paediatric cancer patients compared with CT only. 3 out of 11 patients had a distinct change of target volumes when PET-guided planning was introduced. Dice and mismatch metrics are not sufficient to assess the consequences of target volume differences in the context of RT. PMID:25494657

  12. Assessment of bone segmentation quality of cone-beam CT versus multislice spiral CT: a pilot study.

    NARCIS (Netherlands)

    Loubele, M.; Maes, F.; Schutyser, F.A.C.; Marchal, G.; Jacobs, R.; Suetens, P.

    2006-01-01

    OBJECTIVES: The objective of this study was to quantitatively assess the quality of jawbone models generated from cone beam computed tomography (CBCT) by comparison with similar models obtained from multislice spiral computed tomography (MSCT). MATERIAL AND METHODS: Three case studies were performed

  13. Molecular dynamics study of phonon screening in graphene

    Science.gov (United States)

    Javvaji, Brahmanandam; Roy Mahapatra, D.; Raha, S.

    2014-04-01

    Phonon interaction with electrons or phonons or with structural defects result in a phonon mode conversion. The mode conversion is governed by the frequency wave-vector dispersion relation. The control over phonon mode or the screening of phonon in graphene is studied using the propagation of amplitude modulated phonon wave-packet. Control over phonon properties like frequency and velocity opens up several wave guiding, energy transport and thermo-electric applications of graphene. One way to achieve this control is with the introduction of nano-structured scattering in the phonon path. Atomistic model of thermal energy transport is developed which is applicable to devices consisting of source, channel and drain parts. Longitudinal acoustic phononmode is excited fromone end of the device. Molecular dynamics based time integration is adopted for the propagation of excited phonon to the other end of the device. The amount of energy transfer is estimated from the relative change of kinetic energy. Increase in the phonon frequency decreases the kinetic energy transmission linearly in the frequency band of interest. Further reduction in transmission is observed with the tuning of channel height of the device by increasing the boundary scattering. Phonon mode selective transmission control have potential application in thermal insulation or thermo-electric application or photo-thermal amplification.

  14. Screening studies of yeasts capable of utilizing petroleum fractions

    Energy Technology Data Exchange (ETDEWEB)

    El-Masry, H.G.; Foda, M.S.

    1979-01-01

    In these studies 23 yeasts cultures belonging to 10 genera of ascosporogenous, ballistosporogenous, and asporogenous yeasts, were screened with respect to their abilities of hydrocarbon utilization in synthetic media. Thus, kerosene, n-hexadecane, and wax distillate were compared as sole carbon sources in 2% final concentration. Kerosene exhibited marked inhibition on the growth of the majority of the strains, whereas active growth was observed with Debaryomyces vanrijii and many species of the genus Candida in media with n-hexadecane or wax distillate as sole source of carbon. In addition, some cultures belonging to the genera Sporobolomyces, Hansenula, Cryptococcus, and Trigonopsis could utilize some of these substrates, but to a lesser extent. Highest yield of cells and protein was obtained with Candida lipolytica NRRL 1094 in n-hexadecane medium, supplied with 0.03% yeast extract and trace element solutions. The results are discussed with respect to the possibilities of using new yeast genera, with special reference to the genus Debaryomyces, in microbial protein production.

  15. The comparison of CT fistulography and MR imaging of perianal fistulae with surgical findings: a case-control study.

    Science.gov (United States)

    Soker, Gokhan; Gulek, Bozkurt; Yilmaz, Cengiz; Kaya, Omer; Arslan, Muhammet; Dilek, Okan; Gorur, Mustafa; Kuscu, Ferit; İrkorucu, Oktay

    2016-08-01

    The purpose of this study was to evaluate the diagnostic efficacies of CT fistulography and MRI, in the diagnostic work-up of perianal fistula patients. All 41 patients who were included in the study (36 males and 5 females, with an average age of 41 years) underwent CT fistulography and MRI examinations prior to surgery. The fistula characteristics obtained from these examinations were compared with the surgical findings. The comparative results were evaluated by means of the Kappa analysis method. CT fistulography predicted the correct perianal fistula classification in 30 (73.1%) of the 41 patients, whereas MRI correctly defined fistula classification in 38 (92.7%) of these patients (the K values were 0.621 and 0.896, respectively; with p fistulography depicted 29 secondary extensions in 16 patients, whereas MR imaging revealed 28 secondary extensions in 15 patients. A substantial agreement was found between surgical findings and two modalities (K value was 0.789 and 0.793 for CT fistulography and MRI, respectively, with a p value fistulography was able to detect the locations in 28 patients (68.2%), whereas MRI was more successful in this aspect, with a number of 35 patients (85.3%). Granulation tissues, inflammation and edema around the fistula, abscesses, and fistular wall fibrosis were also evaluated. CT fistulography and MRI have different advantages in the diagnosis of perianal fistulas. A good command of knowledge concerning the issue may be a key factor in modality decision.

  16. A novel method for incorporating respiratory-matched attenuation correction in the motion correction of cardiac PET-CT studies

    Science.gov (United States)

    McQuaid, Sarah J.; Lambrou, Tryphon; Hutton, Brian F.

    2011-05-01

    Mismatches between PET and CT datasets due to respiratory effects can lead to artefactual perfusion defects. To overcome this, we have proposed a method of aligning a single CT with each frame of a gated PET study in a semi-automatic manner, incorporating a statistical shape model of the diaphragm and a rigid registration of the heart. This ensures that the structures that could influence the appearance of the reconstructed cardiac activity are correctly matched between emission and transmission datasets. When tested on two patient studies, it was found in both cases that attenuation correction using the proposed technique resulted in PET images that were closer to the gold standard of attenuation correction with a gated CT, compared with scenarios where only heart matching was considered (and not the diaphragm) or where no transformation was performed (i.e. where a single CT frame was used to attenuation-correct all PET frames). These preliminary results suggest that diaphragm matching between PET and CT improves the quantitative accuracy of reconstructed PET images and that the proposed method of using a statistical shape model to describe the diaphragm shape and motion, in combination with a rigid registration to determine respiratory-induced heart motion, is a feasible method of achieving this.

  17. Children's (Pediatric) CT (Computed Tomography)

    Medline Plus

    Full Text Available ... sensitive to radiation, they should have a CT study only if it is essential for making a diagnosis and should not have repeated CT studies unless absolutely necessary. top of page What are ...

  18. How to study optimal timing of PET/CT for monitoring of cancer treatment

    DEFF Research Database (Denmark)

    Vach, Werner; Høilund-Carlsen, Poul Flemming; Fischer, Barbara Malene Bjerregaard

    2011-01-01

    Purpose: The use of PET/CT for monitoring treatment response in cancer patients after chemo- or radiotherapy is a very promising approach to optimize cancer treatment. However, the timing of the PET/CT-based evaluation of reduction in viable tumor tissue is a crucial question. We investigated how...

  19. How to study optimal timing of PET/CT for monitoring of cancer treatment

    DEFF Research Database (Denmark)

    Vach, Werner; Høilund-Carlsen, Poul Flemming; Fischer, Barbara Malene Bjerregaard;

    2011-01-01

    Purpose: The use of PET/CT for monitoring treatment response in cancer patients after chemo- or radiotherapy is a very promising approach to optimize cancer treatment. However, the timing of the PET/CT-based evaluation of reduction in viable tumor tissue is a crucial question. We investigated how...

  20. Automatic segmentation of human facial tissue by MRI-CT fusion: a feasibility study.

    Science.gov (United States)

    Kale, Emre H; Mumcuoglu, Erkan U; Hamcan, Salih

    2012-12-01

    The aim of this study was to develop automatic image segmentation methods to segment human facial tissue which contains very thin anatomic structures. The segmentation output can be used to construct a more realistic human face model for a variety of purposes like surgery planning, patient specific prosthesis design and facial expression simulation. Segmentation methods developed were based on Bayesian and Level Set frameworks, which were applied on three image types: magnetic resonance imaging (MRI), computerized tomography (CT) and fusion, in which case information from both modalities were utilized maximally for every tissue type. The results on human data indicated that fusion, thickness adaptive and postprocessing options provided the best muscle/fat segmentation scores in both Level Set and Bayesian methods. When the best Level Set and Bayesian methods were compared, scores of the latter were better. Number of algorithm parameters (to be trained) and computer run time measured were also in favour of the Bayesian method.

  1. CT ASSESSMENT OF BRAIN VENTRICULAR SIZE BASED ON AGE AND SEX: A STUDY OF 112 CASES

    Directory of Open Access Journals (Sweden)

    Vinoo

    2013-12-01

    Full Text Available CT being the primary modality of choice in many centers for the diagnosis of brain pathology, normal brain ventricular size measurem ents is an important parameter for the diagnosis of conditions like hydrocephalus, age related atrophic changes and also other brain pathologies producing ventriculomegaly. It is also important for knowing the normal upper and lower limits of the brain ven tricular system in the different age groups, and in both sexes so as to diagnose brain pathology.The ventricular system of the brain undergoes changes with aging and varies with gender.Our study consists of 48 female, and 64 male patients. Apart from the v entricular measurements, two ratios and two indices were also calculated – which included the right and left Evan’s ratio, CM index, and ventricular size inde

  2. Experimental study of heavy-ion computed tomography using a scintillation screen and an electron-multiplying charged coupled device camera for human head imaging

    Science.gov (United States)

    Muraishi, Hiroshi; Hara, Hidetake; Abe, Shinji; Yokose, Mamoru; Watanabe, Takara; Takeda, Tohoru; Koba, Yusuke; Fukuda, Shigekazu

    2016-03-01

    We have developed a heavy-ion computed tomography (IonCT) system using a scintillation screen and an electron-multiplying charged coupled device (EMCCD) camera that can measure a large object such as a human head. In this study, objective with the development of the system was to investigate the possibility of applying this system to heavy-ion treatment planning from the point of view of spatial resolution in a reconstructed image. Experiments were carried out on a rotation phantom using 12C accelerated up to 430 MeV/u by the Heavy-Ion Medical Accelerator in Chiba (HIMAC) at the National Institute of Radiological Sciences (NIRS). We demonstrated that the reconstructed image of an object with a water equivalent thickness (WET) of approximately 18 cm was successfully achieved with the spatial resolution of 1 mm, which would make this IonCT system worth applying to the heavy-ion treatment planning for head and neck cancers.

  3. Screening Preschool Children for Visual Disorders: A Pilot Study

    Directory of Open Access Journals (Sweden)

    Suman Adhikari, BOptom

    2013-12-01

    Full Text Available Purpose: Ocular and/or vision defects are one of the most common reasons for the referral of young children to the hospital. Vision disorders are the fourth most common disability of children and the leading cause of handicapping conditions in childhood. In preschool-age children, amblyopia and amblyogenic risk factors, such as strabismus and significant refractive errors, are the most prevalent and important visual disorders. The purpose of this pilot study was to determine the prevalence of visual disorders in preschool children in Kathmandu Valley, Nepal.Methods: Four hundred and eighty-four children attending eight preschools in Kathmandu Valley underwent detailed optometric examination. Visual acuity was assessed with either Sheridan Gardiner or Kay Picture chart monocularly. Binocularity was assessed with cover test and prism bar neutralisation. Refraction was carried out in all children. In most instances this was done without the use of a cycloplegic agent. Stereopsis was assessed with the Lang stereo test. Anterior and posterior segment abnormalities were assessed by using a pen light, hand-held slit lamp, and direct ophthalmoscope.Results: Refractive error was the most common visual disorder. Considering our criteria of refractive error for myopia ≥ 0.50 D, hyperopia ≥ 1.50 D, astigmatism ≥ 1.00 D, and anisometropia ≥ 1.00 D, the overall prevalence of refractive error in our study was 31.82%. The overall prevalence of myopia, hyperopia, and astigmatism was 24.17%, 2.48%, and 5.17%, respectively. Anisometropia was present in 1.65% of the participants, and 2%, 1.4%, and 0.2% had strabismus, amblyopia, and nystagmus, respectively.Conclusion: The relatively high prevalence of refractive error in our studied population needs more attention. The results suggest that there is a need for a large-scale community-based preschool screening program in Nepal so that affected children can be identified early and appropriate treatment can be

  4. A preliminary study of CT imaging of water in a carnation flower

    Energy Technology Data Exchange (ETDEWEB)

    Nakanishi, T.M. [Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1, Yayoi, Bunkyo-ku, Tokyo 113 (Japan); Furukawa, J. [Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1, Yayoi, Bunkyo-ku, Tokyo 113 (Japan); Matsubayashi, M. [Japan Atomic Energy Research Institute, Tokai-mura, Naka-gun, Ibaraki-ken 319-11 (Japan)

    1999-11-03

    We present the trial to determine the water deletion part in a carnation flower tissue while drying by neutron computer tomography (CT). The flower part was fixed on a rotating disk and thermal neutrons were irradiated for 4 s per projection. The total neutron dose was 6.0x10{sup 8} n/cm{sup 2} per projection. The neutrons penetrating the sample were converted to photons by a fluorescence converter. The photon image was guided to a cooled CCD camera using two mirrors. The sample was rotated, stepwise, every 1 deg. , up to 180 deg. , i.e. 180 images were obtained for the CT construction. Horizontal CT images of several slices of the flower were taken before and after the drying treatment. Vertical CT images of the flower were also constructed based on horizontal CT images. It was found that the water around the ovule was selectively removed by the drying treatment.

  5. A preliminary study of CT imaging of water in a carnation flower

    Science.gov (United States)

    Nakanishi, T. M.; Furukawa, J.; Matsubayashi, M.

    1999-11-01

    We present the trial to determine the water deletion part in a carnation flower tissue while drying by neutron computer tomography (CT). The flower part was fixed on a rotating disk and thermal neutrons were irradiated for 4 s per projection. The total neutron dose was 6.0×10 8 n/cm 2 per projection. The neutrons penetrating the sample were converted to photons by a fluorescence converter. The photon image was guided to a cooled CCD camera using two mirrors. The sample was rotated, stepwise, every 1°, up to 180°, i.e. 180 images were obtained for the CT construction. Horizontal CT images of several slices of the flower were taken before and after the drying treatment. Vertical CT images of the flower were also constructed based on horizontal CT images. It was found that the water around the ovule was selectively removed by the drying treatment.

  6. Long-term prognostic impact of CT-Leaman score in patients with non-obstructive CAD: Results from the COronary CT Angiography EvaluatioN For Clinical Outcomes InteRnational Multicenter (CONFIRM) study.

    Science.gov (United States)

    Andreini, Daniele; Pontone, Gianluca; Mushtaq, Saima; Gransar, Heidi; Conte, Edoardo; Bartorelli, Antonio L; Pepi, Mauro; Opolski, Maksymilian P; Ó Hartaigh, Bríain; Berman, Daniel S; Budoff, Matthew J; Achenbach, Stephan; Al-Mallah, Mouaz; Cademartiri, Filippo; Callister, Tracy Q; Chang, Hyuk-Jae; Chinnai