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Sample records for contrast-enhanced multi-detector computed

  1. Anatomical variation of thyroid veins on contrast-enhanced multi-detector row computed tomography

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    Tomita, Hayato, E-mail: m04149@yahoo.co.jp [Department of Radiology, St. Marianna University School of Medicine, Yokohama City Seibu Hospital, 1197-1 Yasashicho, Asahi-ku, Yokohama, Kanagawa 241-0811 (Japan); Yamada, Takayuki; Murakami, Kenji; Hashimoto, Kazuki; Tazawa, Yoko; Kumano, Reiko [Department of Radiology, St. Marianna University School of Medicine, Yokohama City Seibu Hospital, 1197-1 Yasashicho, Asahi-ku, Yokohama, Kanagawa 241-0811 (Japan); Nakajima, Yasuo [Department of Radiology, St. Marianna University School of Medicine, 2-16-1 Sugao, Miyamae-ku, Kawasaki, Kanagawa 216-8511 (Japan)

    2015-05-15

    Highlights: • This is the first study to demonstrate the anatomy of thyroid veins on contrasted-enhanced MDCT. • Identifying the thyroid vein on MDCT prior to selective venous sampling of parathyroid hormone provides clinical information to interventional radiologist. • Detecting especially the inferior thyroid veins with individual variability in numbers, locations, and lengths may have an effect on SVS for HPT and decrease the difficulty and time of the procedure. - Abstract: Objective: The objective of this study was to clarify the anatomical variation of thyroid veins into the systemic vein using contrast-enhanced multi-detector row computed tomography (MDCT). Design and methods: : The subjects were 80 patients (34 males and 46 females; mean age, 50.1 years; age range, 15–92 years) with neck diseases who underwent MDCT. The number and location of inflow points of the thyroid veins into the systemic vein, and the length from the junction of bilateral brachiocephalic veins to the orifice of inferior thyroid vein were investigated by reviewing the axial and coronal images. Results: All superior thyroid veins were detected. Right and left middle thyroid veins were identified in 39 and 29 patients, respectively. Right inferior thyroid veins, left inferior thyroid veins, and common trunks were detected in 43, 46, and 39 patients, respectively; in five patients, two left thyroid veins were identified. All left inferior thyroid veins and 34 common trunks flowed into the innominate vein, while right ones had some variations in inflow sites. Mean lengths were 3.01 ± 1.30 cm (range, 0.5–6.19) and 2.04 ± 0.91 cm (0.5–4.4) in the left inferior thyroid vein and common trunk, and 1.96 ± 1.05 cm (0.81–4.8) and 1.65 ± 0.69 cm (0.63–2.94) in the right one flowing into the right internal jugular vein and the innominate vein, respectively. Conclusions: The numbers and orifices of thyroid veins were identified at high rates on contrast-enhanced MDCT. This

  2. Threshold-dependent variability of coronary artery calcification measurements - implications for contrast-enhanced multi-detector row-computed tomography

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    Moselewski, Fabian [Division of Cardiology, Massachusetts General Hospital and Harvard Medical School, Boston, MA (United States); Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Boston, MA (United States); Ferencik, Maros [Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Boston, MA (United States); Achenbach, Stephan [Division of Cardiology, Massachusetts General Hospital and Harvard Medical School, Boston, MA (United States); Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Boston, MA (United States); Department of Internal Medicine II (Cardiology), University of Erlangen (Germany); Abbara, Suhny [Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Boston, MA (United States); Cury, Ricardo C. [Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Boston, MA (United States); Booth, Sarah L. [Jean Mayer USDA Human Nutrition Research Center on Aging, 711 Washington St., Boston, MA 02114 (United States); Jang, Ik-Kyung [Division of Cardiology, Massachusetts General Hospital and Harvard Medical School, Boston, MA (United States); Brady, Thomas J. [Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Boston, MA (United States); Hoffmann, Udo [Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Boston, MA (United States)]. E-mail: uhoffman@partners.org

    2006-03-15

    Introduction: The present study investigated the threshold-dependent variability of coronary artery calcification (CAC) measurements and the potential to quantify CAC in contrast-enhanced multi-detector row-computed tomography (MDCT). Methods: We compared the mean CT attenuation of CAC to luminal contrast enhancement of the coronary arteries in 30 patients (n = 30) undergoing standard coronary contrast-enhanced spiral MDCT. The modified Agatston score [AS], calcified plaque volume [CV], and mineral mass [MM] at four different thresholds (130, 200, 300, and 400 HU) were measured in 50 patients who underwent non-contrast-enhanced MDCT. Results: Mean CT attenuation of CAC was similar to the attenuation of the contrast-enhanced coronary lumen (CAC 297.1 {+-} 68.7 HU versus 295 {+-} 65 HU (p < 0.0001), respectively). Above a threshold of 300 HU CAC measurements significantly varied to standard measurements obtained at a threshold of 130 HU (p < 0.0001). The threshold-dependent variation of MM measurements was significantly smaller than for AS and CV (130 HU versus 400 HU: 63, 75, and 81, respectively; p < 0.001). These differences resulted in a change of age and gender based percentile category for AS in 78% of subjects. Discussion: We demonstrated that CAC measurements are threshold dependent with MM measurements having significantly less variation than AS or CV. Due to the similarity of mean CT attenuation of CAC and the contrast-enhanced coronary lumen accurate quantification of CAC may be difficult in standard coronary contrast-enhanced spiral MDCT.

  3. Relevant incidental findings at abdominal multi-detector contrast-enhanced computed tomography:A collateral screening?

    Institute of Scientific and Technical Information of China (English)

    Luca; Maria; Sconfienza; Giovanni; Mauri; Claudia; Muzzupappa; Alessandro; Poloni; Michele; Bandirali; Anastassia; Esseridou; Stefania; Tritella; Francesco; Secchi; Giovanni; Di; Leo; Francesco; Sardanelli

    2015-01-01

    AIM: To investigate the prevalence of relevant incidental findings(RIFs) detected during routine abdominal contrast-enhanced computed tomography(Ce CT).METHODS: We retrospectively evaluated the reports of a consecutive series of abdominal Ce CT studies performed between January and May 2013. For each report, patients’ age and sex, admission as inpatient or outpatient, clinical suspicion as indicated by the requesting physician, availability of a previous abdominal examination, and name of the reporting radiologist were recorded. Based on the clinical suspicion, the presence and features of any RIFs(if needing additional workup) was noted.RESULTS: One thousand forty abdominal Ce CT were performed in 949 patients(528 males, mean age 66 ±14 years). No significant difference was found between inpatients and outpatients age and sex distribution(P > 0.472). RIFs were found in 195/1040(18.8%) Ce CT [inpatients = 108/470(23.0%); outpatients = 87/570(15.2%); P = 0.002]. RIFs were found in 30/440(6.8%) Ce CT with a previous exam and in 165/600(27.5%) without a previous exam(P < 0.001). Radiologists’ distribution between inpatients or outpatients was significantly different(P < 0.001). RIFs prevalence increased with aging, except for a peak in 40-49 year group. Most involved organs were kidneys, gallbladder, and lungs.CONCLUSION: A RIF is detected in 1/5 patients undergoing abdominal Ce CT. Risk of overdiagnosis should be taken into account.

  4. Contrast enhanced multi-detector CT and MR findings of a well-differentiated pancreatic vipoma.

    Science.gov (United States)

    Camera, Luigi; Severino, Rosa; Faggiano, Antongiulio; Masone, Stefania; Mansueto, Gelsomina; Maurea, Simone; Fonti, Rosa; Salvatore, Marco

    2014-10-28

    Pancreatic vipoma is an extremely rare tumor accounting for less than 2% of endocrine pancreatic neoplasms with a reported incidence of 0.1-0.6 per million. While cross-sectional imaging findings are usually not specific, exact localization of the tumor by means of either computed tomography (CT) or magnetic resonance (MR) is pivotal for surgical planning. However, cross-sectional imaging findings are usually not specific and further characterization of the tumor may only be achieved by somatostatin-receptor scintigraphy (SRS). We report the case of a 70 years old female with a two years history of watery diarrhoea who was found to have a solid, inhomogeneously enhancing lesion at the level of the pancreatic tail at Gadolinium-enhanced MR (Somatom Trio 3T, Siemens, Germany). The tumor had been prospectively overlooked at a contrast-enhanced multi-detector CT (Aquilion 64, Toshiba, Japan) performed after i.v. bolus injection of only 100 cc of iodinated non ionic contrast media because of a chronic renal failure (3.4 mg/mL) but it was subsequently confirmed by SRS. The patient first underwent a successful symptomatic treatment with somatostatin analogues and was then submitted to a distal pancreasectomy with splenectomy to remove a capsulated whitish tumor which turned out to be a well-differentiated vipoma at histological and immuno-histochemical analysis.

  5. Contrast enhanced multi-detector CT and MR findings of a well-differentiated pancreatic vipoma

    Institute of Scientific and Technical Information of China (English)

    Luigi; Camera; Rosa; Severino; Antongiulio; Faggiano; Stefania; Masone; Gelsomina; Mansueto; Simone; Maurea; Rosa; Fonti; Marco; Salvatore

    2014-01-01

    Pancreatic vipoma is an extremely rare tumor accounting for less than 2% of endocrine pancreatic neoplasms with a reported incidence of 0.1-0.6 per million. While cross-sectional imaging findings are usually not specific, exact localization of the tumor by means of either computed tomography(CT) or magnetic resonance(MR) is pivotal for surgical planning. However, cross-sectional imaging findings are usually not specific and further characterization of the tumor may only be achieved bysomatostatin-receptor scintigraphy(SRS). We report the case of a 70 years old female with a two years history of watery diarrhoea who was found to have a solid, inhomogeneously enhancing lesion at the level of the pancreatic tail at Gadolinium-enhanced MR(Somatom Trio 3T, Siemens, Germany). The tumor had been prospectively overlooked at a contrast-enhanced multi-detector CT(Aquilion 64, Toshiba, Japan) performed after i.v. bolus injection of only 100 cc of iodinated non ionic contrast media because of a chronic renal failure(3.4 mg/mL) but it was subsequently confirmed by SRS. The patient first underwent a successful symptomatic treatment with somatostatin analogues and was then submitted to a distal pancreasectomy with splenectomy to remove a capsulated whitish tumor which turned out to be a well-differentiated vipoma at histological and immuno-histochemical analysis.

  6. Can contrast-enhanced multi-detector computed tomography replace transesophageal echocardiography for the detection of thrombogenic milieu and thrombi in the left atrial appendage. A prospective study with 124 patients; Kann die kontrastmittelverstaerkte Mehrzeilen-Computertomografie die transoesophageale Echokardiografie bei der Detektion von thrombogenem Milieu und Vorhofohrthromben ersetzen? Eine prospektive Studie mit 124 Patienten

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    Homsi, R.; Luetkens, J.A.; Schild, H.H.; Naehle, C.P. [Bonn Univ. (Germany). Dept. of Radiology; Nath, B. [SHG-KLliniken Voelklingen (Germany). Dept. of Medicine I - Cardiology; Schwab, J.O. [Bonn Univ. (Germany). Dept. of Medicine I - Cardiology

    2016-01-15

    To assess the diagnostic value of contrast-enhanced multi-detector computed tomography (MD-CT) for identifying patients with left atrial appendage (LAA) thrombus or circulatory stasis. 124 patients with a history of atrial fibrillation and/or cerebral ischemia (83 men, mean age 58.6 ± 12.4 years) and with a clinical indication for MD-CT of the heart and for transesophageal echocardiography (TEE) were included in the study. LAA thrombus or thrombogenic milieu was visually identified in TEE and MD-CT. In addition, MD-CT was analyzed quantitatively measuring the Hounsfield units (HU) of the left atrium (LA), the LAA and the ascending aorta (AA), and calculating the HU ratios LAA/AA (HU [LAA/AA]) und LAA/LA (HU [LAA/LA]). Sensitivity, specificity, negative predictive value (NPV) and positive predictive value (PPV) were calculated. The prevalence of a thrombus or thrombogenic milieu as assessed by TEE was 21.8 %. The HU ratio was lower in patients with thrombus or thrombogenic milieu (HU [LAA/AA]: 0.590 ± 0.248 vs. 0.909 ± 0.141; p < 0.001 und HU [LAA/LA] 0.689 ± 0.366 vs. 1.082 ± 0.228; p < 0.001). For the diagnosis of thrombus or a thrombogenic milieu, visual analysis yielded a sensitivity of 81.5 %, a specificity of 96.9 %, a PPV of 87.5 % and a NPV of 95.2 %. By combining visual and quantitative analysis with one criterion being positive, the specificity decreased to 91.8 %, the sensitivity to 77.8 %, the PPV to 72.4 %, and the NPV to 94.9 %. Visual analysis of the LAA in the evaluation of thrombus or thrombogenic milieu yields a high NPV of 95.1 % and may especially be useful to rule out LAA thrombi in patients with contraindications for TEE. Additional calculation of HU ratios did not improve the diagnostic performance of MD-CT.

  7. Liver tumour segmentation using contrast-enhanced multi-detector CT data: performance benchmarking of three semiautomated methods

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    Zhou, Jia-Yin [National University of Singapore, Department of Diagnostic Radiology, Yong Loo Lin School of Medicine, Singapore (Singapore); Agency for Science, Technology and Research, Institute for Infocomm Research, Singapore (Singapore); Wong, Damon W.K.; Tian, Qi; Xiong, Wei; Liu, Jimmy J. [Agency for Science, Technology and Research, Institute for Infocomm Research, Singapore (Singapore); Ding, Feng; Venkatesh, Sudhakar K.; Qi, Ying-Yi [National University of Singapore, Department of Diagnostic Radiology, Yong Loo Lin School of Medicine, Singapore (Singapore); Leow, Wee-Kheng [National University of Singapore, School of Computing, Singapore (Singapore)

    2010-07-15

    Automatic tumour segmentation and volumetry is useful in cancer staging and treatment outcome assessment. This paper presents a performance benchmarking study on liver tumour segmentation for three semiautomatic algorithms: 2D region growing with knowledge-based constraints (A1), 2D voxel classification with propagational learning (A2) and Bayesian rule-based 3D region growing (A3). CT data from 30 patients were studied, and 47 liver tumours were isolated and manually segmented by experts to obtain the reference standard. Four datasets with ten tumours were used for algorithm training and the remaining 37 tumours for testing. Three evaluation metrics, relative absolute volume difference (RAVD), volumetric overlap error (VOE) and average symmetric surface distance (ASSD), were computed based on computerised and reference segmentations. A1, A2 and A3 obtained mean/median RAVD scores of 17.93/10.53%, 17.92/9.61% and 34.74/28.75%, mean/median VOEs of 30.47/26.79%, 25.70/22.64% and 39.95/38.54%, and mean/median ASSDs of 2.05/1.41 mm, 1.57/1.15 mm and 4.12/3.41 mm, respectively. For each metric, we obtained significantly lower values of A1 and A2 than A3 (P < 0.01), suggesting that A1 and A2 outperformed A3. Compared with the reference standard, the overall performance of A1 and A2 is promising. Further development and validation is necessary before reliable tumour segmentation and volumetry can be widely used clinically. (orig.)

  8. Multi-dimensional visualization of coronary aberrancies using multi detector computed tomography

    NARCIS (Netherlands)

    van Ooijen, P; Dorgelo, J; Tukker, W; Willemsen, H; Oudkerk, M; Lewis, BS; Halon, DA; Flugelman, MY; Gensini, GF

    2003-01-01

    The purpose of this study was to evaluate the usefulness of three and four dimensional visualization of multi detector computed tomography datasets for the evaluation of coronary aberrancies. Multi detector computed tomography (MDCT) datasets were obtained in thirteen patients following a standard p

  9. Predicting Neck Abscess with Contrast-Enhanced Computed Tomography

    OpenAIRE

    2014-01-01

    Neck abscesses are difficult to diagnose and treat. Currently, contrast-enhanced computed tomography (CECT) is the imaging modality of choice. The study aims to determine the predictive value of CECT findings in diagnosing neck abscess, causes of neck abscess and the most common neck space involved in the local population. 84 consecutive patients clinically suspected to have neck abscess who underwent CECT and surgical confirmation of pus were included. Demographic and clinical data were reco...

  10. Molecular imaging with dynamic contrast-enhanced computed tomography

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    Miles, K.A., E-mail: k.a.miles@bsms.ac.u [Clinical Imaging Sciences Centre, Brighton and Sussex Medical School, University of Sussex, Falmer, Brighton (United Kingdom)

    2010-07-15

    Dynamic contrast-enhanced computed tomography (DCE-CT) is a quantitative technique that employs rapid sequences of CT images after bolus administration of intravenous contrast material to measure a range of physiological processes related to the microvasculature of tissues. By combining knowledge of the molecular processes underlying changes in vascular physiology with an understanding of the relationship between vascular physiology and CT contrast enhancement, DCE-CT can be redefined as a molecular imaging technique. Some DCE-CT derived parameters reflect tissue hypoxia and can, therefore, provide information about the cellular microenvironment. DCE-CT can also depict physiological processes, such as vasodilatation, that represent the physiological consequences of molecular responses to tissue hypoxia. To date the main applications have been in stroke and oncology. Unlike some other molecular imaging approaches, DCE-CT benefits from wide availability and ease of application along with the use of contrast materials and software packages that have achieved full regulatory approval. Hence, DCE-CT represents a molecular imaging technique that is applicable in clinical practice today.

  11. Quantitative assessment of early experimental diabetes in rats using dynamic contrast-enhanced computed tomography

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    Murase, Kenya [Department of Medical Physics and Engineering, Division of Medical Technology and Science, Faculty of Health Science, Graduate School of Medicine, Osaka University, 1-7 Yamadaoka, Suita, Osaka 565-0871 (Japan)], E-mail: murase@sahs.med.osaka-u.ac.jp; Kitamura, Akihiro; Tachibana, Atsushi; Kusakabe, Yoshinori; Matsuura, Risa; Miyazaki, Shohei [Department of Medical Physics and Engineering, Division of Medical Technology and Science, Faculty of Health Science, Graduate School of Medicine, Osaka University, 1-7 Yamadaoka, Suita, Osaka 565-0871 (Japan)

    2010-04-15

    Purpose: To quantitatively assess the time course of changes of the renal volume and function in the early phase of streptozotocin (STZ)-induced diabetes in rats using dynamic contrast-enhanced computed tomography (DCE-CT). Methods: The DCE-CT studies were performed in 24 male Sprague-Dawley rats (n = 6 for control and n = 18 for STZ-treated group) on days 0, 4, 7, 11, and 14 using a multi-detector row CT. The rats of an STZ-treated group were given intraperitoneally 65 mg/kg body weight of STZ on day 0, and were divided into two groups based on the blood glucose concentration on day 4 being less than 300 mg/dL [STZ-treated group (L), n = 8] or greater than 300 mg/dL [STZ-treated group (G), n = 10]. The contrast clearance per unit renal volume (K{sub 1}) was estimated from the DCE-CT data using the Patlak model. The renal volume (V{sub CT}) was calculated by manually delineating the kidney on the contrast-enhanced CT image. The contrast clearance of the entire kidney (K) was obtained by K{sub 1} x V{sub CT}. Results: V{sub CT} in the STZ-treated group was significantly enlarged on day 4 compared to that on day 0 and continued until day 14. Although there were no significant changes in the time course of K{sub 1} in all groups, K in the STZ-treated groups (L) and (G) significantly increased on days 7 and 4, respectively, and continued until day 14, suggesting that hyperfiltration occurs in parallel with renal volume enlargement. Conclusion: The present method appears useful for quantitatively evaluating the time course of STZ-induced diabetes in rats, because it allows repeated and simultaneous evaluation of renal morphology and function.

  12. Predicting Neck Abscess with Contrast-Enhanced Computed Tomography

    Directory of Open Access Journals (Sweden)

    Melisa Lim Seer Yee

    2014-01-01

    Full Text Available Neck abscesses are difficult to diagnose and treat. Currently, contrast-enhanced computed tomography (CECT is the imaging modality of choice. The study aims to determine the predictive value of CECT findings in diagnosing neck abscess, causes of neck abscess and the most common neck space involved in the local population. 84 consecutive patients clinically suspected to have neck abscess who underwent CECT and surgical confirmation of pus were included. Demographic and clinical data were recorded. 75 patients were diagnosed as having neck abscess on CECT; out of those 71 patients were found to have pus. Overall CECT findings were found to have a high sensitivity (98.6% and positive predictive value (PPV (94.7% but lower specificity (67.2% in diagnosing neck abscess. The CECT diagnostic criterion with the highest PPV is the presence of rim irregularity (96%. The most common deep neck space involved is the submandibular compartment, which correlates with the finding that odontogenic cause was the most common identifiable cause of abscess in the study population. Thus, in a patient clinically suspected of having neck abscess, CECT findings of a hypodense mass with rim irregularity are helpful in confirming the diagnosis and guiding clinical management.

  13. Contrast-enhanced fluorodeoxyglucose positron emission tomography/contrast-enhanced computed tomography in mediastinal T-cell lymphoma with superior vena cava syndrome.

    Science.gov (United States)

    Santhosh, Sampath; Gorla, Arun Kumar Reddy; Bhattacharya, Anish; Varma, Subhash Chander; Mittal, Bhagwant Rai

    2016-01-01

    Positron emission tomography-computed tomography (PET/CT) is a routine investigation for the staging of lymphomas. Contrast-enhanced computed tomography is mandatory whenever parenchymal lesions, especially in the liver and spleen are suspected. We report a rare case of primary mediastinal T-cell lymphoma evaluated with contrast-enhanced PET/CT that showed features of superior vena cava syndrome.

  14. Tuberculous abscess in hepatoduodenal ligament: Evaluation with contrast-enhanced computed tomography

    Institute of Scientific and Technical Information of China (English)

    Peng Dong; Bin Wang; Ye-Quan Sun

    2008-01-01

    Two patients with tuberculous abscess in the hepatoduodenal ligament were studied. Both patients underwent contrast-enhanced computed tomography (CT) scan. The abscess showed a low density with an irregular thick wall in the hepatoduodenal ligament on CT images, the margin was poorly defined. Contrastenhanced CT images showed the contrast-enhanced thick wall, homogeneous and peripheral-enhanced lymph nodes. Although features of the tuberculous abscess in the hepatoduodenal ligament could be conspicuously shown with contrast-enhanced CT, further experience is needed to evaluate the potential value of CT in detecting early tuberculous abscess in relation to other entities in the hepatoduodenal ligament.

  15. Multi-detector computed tomography imaging of large airway pathology:A pictorial review

    Institute of Scientific and Technical Information of China (English)

    Tejeshwar Singh Jugpal; Anju Garg; Gulshan Rai Sethi; Mradul Kumar Daga; Jyoti Kumar

    2015-01-01

    The tracheobronchial tree is a musculo-cartilagenous framework which acts as a conduit to aerate the lungs and consequently the entire body. A large spectrum of pathological conditions can involve the trachea and bronchial airways. These may be congenital anomalies, infections, post-intubation airway injuries, foreign body aspiration or neoplasms involving the airway. Appropriate management of airway disease requires an early and accurate diagnosis. In this pictorial essay review, we will comprehensively describe the various airway pathologies and their imaging findings by multi-detector computed tomography.

  16. Identification of Cardiac and Aortic Injuries in Trauma with Multi-detector Computed Tomography.

    Science.gov (United States)

    Shergill, Arvind K; Maraj, Tishan; Barszczyk, Mark S; Cheung, Helen; Singh, Navneet; Zavodni, Anna E

    2015-01-01

    Blunt and penetrating cardiovascular (CV) injuries are associated with a high morbidity and mortality. Rapid detection of these injuries in trauma is critical for patient survival. The advent of multi-detector computed tomography (MDCT) has led to increased detection of CV injuries during rapid comprehensive scanning of stabilized major trauma patients. MDCT has the ability to acquire images with a higher temporal and spatial resolution, as well as the capability to create multiplanar reformats. This pictorial review illustrates several common and life-threatening traumatic CV injuries from a regional trauma center.

  17. Identification of Cardiac and Aortic Injuries in Trauma with Multi-detector Computed Tomography

    Directory of Open Access Journals (Sweden)

    Arvind K Shergill

    2015-01-01

    Full Text Available Blunt and penetrating cardiovascular (CV injuries are associated with a high morbidity and mortality. Rapid detection of these injuries in trauma is critical for patient survival. The advent of multi-detector computed tomography (MDCT has led to increased detection of CV injuries during rapid comprehensive scanning of stabilized major trauma patients. MDCT has the ability to acquire images with a higher temporal and spatial resolution, as well as the capability to create multiplanar reformats. This pictorial review illustrates several common and life-threatening traumatic CV injuries from a regional trauma center.

  18. Hypovolemic shock ond contrast-enhanced computed tomography of the pancreas

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    Nuutinen, P.; Kivisaari, L.; Lehtola, A.; Standertskjoeld-Nordenstam, C.G.; Lempinen, M.; Schroeder, T.; Talja, M,

    1986-01-01

    The effect of profound hemorrhagic hypovolemia on cardiac output and pancreatic blood flow was studied in pigs with the thermodilution method and microspere technique. Approximately 30 to 40% of the circulating blood volume was withdrawn slowly during 5 h. Cardiac output and pancreatic blood flow decreased by 35% and 32%, respectively. The animals underwent contrast-enhanced computed tomography (CT) before hypovolemia and at 5 h after its onset. The changes in systemic and local blood flow were related to the contrast enhancement of the pancreas. In spite of profound hypovolemia and a significant decrease in pancreatic blood flow (p<0.005), the contrast enhancement remained normal. The results of the present study indicate that pancreatic hypoperfusion caused by hypovolemia does not effect the contrast enhancement of the pancreas in CT.

  19. Diagnosis of hepatic steatosis by contrast-enhanced abdominal computed tomography

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    Rodrigo da Fonseca Monjardim

    2013-06-01

    Full Text Available Objective To evaluate the diagnostic capacity of abdominal computed tomography in the assessment of hepatic steatosis using the portal phase with a simplified calculation method as compared with the non-contrast-enhanced phase. Materials and Methods In the present study, 150 patients were retrospectively evaluated by means of non-contrast-enhanced and contrast-enhanced computed tomography. One hundred patients had hepatic steatosis and 50 were control subjects. For the diagnosis of hepatic steatosis in the portal phase, the authors considered a result of < 104 HU calculated by the formula [L - 0.3 × (0.75 × P + 0.25 × A] / 0.7, where L, P and A represent the attenuation of the liver, of the main portal vein and abdominal aorta, respectively. Sensitivity, specificity, positive and negative predictive values were calculated, using non-contrast-enhanced computed tomography as the reference standard. Results The simplified calculation method with portal phase for the diagnosis of hepatic steatosis showed 100% sensitivity, 36% specificity, negative predictive value of 100% and positive predictive value of 75.8%. The rate of false positive results was 64%. False negative results were not observed. Conclusion The portal phase presents an excellent sensitivity in the diagnosis of hepatic steatosis, as compared with the non-contrast-enhanced phase of abdominal computed tomography. However, the method has low specificity.

  20. Hepatic blood perfusion estimated by dynamic contrast-enhanced computed tomography in pigs

    DEFF Research Database (Denmark)

    Winterdahl, Michael; Sørensen, Michael; Keiding, Inger Susanne;

    2012-01-01

    The aim of this study was to determine whether dynamic contrast-enhanced computed tomography (DCE-CT) and the slope method can provide absolute measures of hepatic blood perfusion from the hepatic artery (HA) and portal vein (PV) at experimentally varied blood flow rates.......The aim of this study was to determine whether dynamic contrast-enhanced computed tomography (DCE-CT) and the slope method can provide absolute measures of hepatic blood perfusion from the hepatic artery (HA) and portal vein (PV) at experimentally varied blood flow rates....

  1. The prevalence of undiagnosed abnormalities on non-contrast-enhanced computed tomography compared to contrast-enhanced computed tomography of the brain

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    Cornelia Minné

    2014-04-01

    Full Text Available Background: Even though magnetic resonance imaging (MRI is the gold standard investigation for intracranial pathology, it is not widely available in developing countries and computed tomography (CT of the brain remains the first-line investigation for patients with suspected intracranial pathology. It is generally accepted that certain intracranial pathology can be missed on non-contrast-enhanced CT (NECT of the brain if a contrast-enhanced CT (CECT is not done. We have to consider on the one hand the risk of delayed or missed diagnosis and on the other hand the cost, increased radiation exposure and contrast-induced reactions. Advances in CT technology have also improved the resolution of CT scan images, making it easier to identify pathology on an NECT of the brain. To date, no study comparing NECT to CECT of the brain, utilising 64-slice CT technology, has been published.Objectives: To determine the prevalence of undiagnosed abnormalities on non-contrast-enhanced computed tomography (NECT scans of the brain reported as normal, on a 64-slice CT scanner.Method: A descriptive retrospective study was undertaken of CT brain scans done during a 12-month period at a tertiary provincial hospital in the Northern Tshwane district of Gauteng, South Africa. The CT brain scans were evaluated by three reviewers (general radiologists. The NECT and contrast-enhanced computed tomography (CECT scans of the brain were reviewed independently on separate occasions. Reviewers were blinded to patient history, each other’s interpretation, and to their own interpretation of the NECT when evaluating the CECT and vice versa. Discrepancies in interpretation were resolved during a consensus meeting between all three reviewers. The reviewers also re-evaluated the NECT scans of the cases with undiagnosed abnormal findings during this session. A decision was made pertaining to the visibility of the abnormal findings on the NECT scan.Results: In this study, 3.28% of cases

  2. Evaluation of contrast-enhanced computed tomographic colonography in detection of local recurrent colorectal cancer

    Institute of Scientific and Technical Information of China (English)

    Yau-Tong You; Chung-Rong Chang Chien; Jeng-Yi Wang; Koon-Kwan Ng; Jinn-Shiun Chen; Reiping Tang; Jy-Ming Chiang; Chien-Yuh Yeh; Pao-Shiu Hsieh

    2006-01-01

    AIM: To evaluate the diagnostic accuracy, sensitivity,specificity of contrast-enhanced computed tomographic colonography in detecting local recurrence of colorectal cancer.METHODS: From January 2000 to December 2004,434 patients after potentially curative resection for invasive colorectal cancer were followed up for a period ranging from 20 to 55 mo. Eighty of the four hundred and thirty-four patients showing strong clinical evidence for recurring colorectal cancer during the last followup were enrolled in this study. Each patient underwent contrast-enhanced computed tomographic colonography and colonoscopy on the same day. Any lesions, biopsies,identified during the colonoscopic examination, immediate complications and the duration of the procedure were recorded. The results of contrast-enhanced computed tomographic colonography were evaluated by comparing to those of colonoscopy, surgical finding, and clinical follow-up.RESULTS: Contrast-enhanced computed tomographic colonography had a sensitivity of 100%, a specificity of 83% and an overall accuracy of 94% in detecting local recurrent colorectal cancer.CONCLUSION: Conventional colonoscopy and contrastenhanced tomographic colonography can complement each other in detecting local recurrence of colorectal cancer.

  3. Multi-detector Computed Tomography Angiography of the Hepatic Artery in Liver Transplant Recipients

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    Boraschi, P.; Donati, F.; Cossu, M.C.; Gigoni, R.; Vignali, C.; Filipponi, F.; Bartolozzi, C.; Falaschi, F. [Pisa Univ. Hospital (Italy). 2nd Dept. of Radiology

    2005-08-01

    PURPOSE: To evaluate the ability of multi-detector row computed tomography angiography (CTA) in detecting hepatic artery complications in the follow-up of liver transplant patients, performing volume-rendering as reconstruction technique. MATERIAL AND METHODS: The anatomy of hepatic artery was studied in 27 liver transplant recipients with a four-row CT scanner using the following parameters: collimation, 1 mm; slice width, 1 mm; table feed, 6-8 mm/s; spiral reconstruction time, 0.5 s; reconstruction interval, 0.5 mm; mAs, 160; kVp, 120. Before the study, the patients received 1000 ml of water as oral contrast agent to produce negative contrast in the stomach and the small bowel. A non-ionic contrast medium was infused intravenously at a rate of 5 ml/s with a bolus tracking system. Volume-rendering of hepatic artery was performed with the 3D Virtuoso software. RESULTS: The celiac trunk, the hepatic artery, and the right and left hepatic arteries were successfully displayed in high detail in all patients. Side branches, including small collaterals, and hepatic artery anastomosis could also be readily visualized. Volume-rendered CTA detected six hepatic artery stenoses, two hepatic artery thromboses, and two intrahepatic pseudoaneurysms. In two cases, CT detected hepatic artery stenosis with a diameter reduction of less than 50%, while digital subtraction angiography showed a normal artery. CONCLUSION: Volume-rendered multi-detector CTA is a promising non-invasive technique, since it allows images of high quality to be generated with excellent anatomical visualization of the hepatic artery and its complications in liver transplant recipients.

  4. Recurrence of Takotsubo Cardiomyopathy: Role of Multi- Detector Computed Tomography Coronary Angiography

    Directory of Open Access Journals (Sweden)

    Yaser Jenab

    2015-10-01

    Full Text Available Takotsubo cardiomyopathy (TCM, also known as stress-induced cardiomyopathy, is a clinical syndrome of transient left ventricular (LV apical wall motion abnormality with relative preservation of the basal heart segments in the absence of any significant atherosclerosis. Recurrence of this condition is rare. We report a postmenopausal woman, who experienced two episodes of TCM within 4 months following emotional and physical stress. In the first episode, she was admitted due to severe dyspnea, accompanied by sudden-onset, prolonged, burning chest pain and palpitation. Transthoracic echocardiography revealed akinesia of the LV, with the exception of the basal regions. Coronary angiography demonstrated no significant coronary artery disease, and follow-up echocardiography showed normalization of the LV wall motion abnormalities. In the second episode, she experienced similar symptoms and echocardiography revealed similar changes. Multi-detector computed tomography revealed normal coronary arteries. After 9 days, she was discharged in good condition; and at 3 months’ follow- up, she was symptom-free with normal echocardiography.

  5. [Weighted-averaging multi-planar reconstruction method for multi-detector row computed tomography].

    Science.gov (United States)

    Aizawa, Mitsuhiro; Nishikawa, Keiichi; Sasaki, Keita; Kobayashi, Norio; Yama, Mitsuru; Sano, Tsukasa; Murakami, Shin-ichi

    2012-01-01

    Development of multi-detector row computed tomography (MDCT) has enabled three-dimensions (3D) scanning with minute voxels. Minute voxels improve spatial resolution of CT images. At the same time, however, they increase image noise. Multi-planar reconstruction (MPR) is one of effective 3D-image processing techniques. The conventional MPR technique can adjust slice thickness of MPR images. When a thick slice is used, the image noise is decreased. In this case, however, spatial resolution is deteriorated. In order to deal with this trade-off problem, we have developed the weighted-averaging multi-planar reconstruction (W-MPR) technique to control the balance between the spatial resolution and noise. The weighted-average is determined by the Gaussian-type weighting function. In this study, we compared the performance of W-MPR with that of conventional simple-addition-averaging MPR. As a result, we could confirm that W-MPR can decrease the image noise without significant deterioration of spatial resolution. W-MPR can adjust freely the weight for each slice by changing the shape of the weighting function. Therefore, W-MPR can allow us to select a proper balance of spatial resolution and noise and at the same time produce suitable MPR images for observation of targeted anatomical structures.

  6. Multi-detector row computed tomography: Imaging in acute aortic syndrome

    Energy Technology Data Exchange (ETDEWEB)

    Manghat, N.E. [Department of Clinical Radiology, Derriford Hospital, Plymouth, Devon (United Kingdom)]. E-mail: docnatman@msn.com; Morgan-Hughes, G.J. [Department of Cardiology, Derriford Hospital, Plymouth, Devon (United Kingdom); Roobottom, C.A. [Department of Clinical Radiology, Derriford Hospital, Plymouth, Devon (United Kingdom)

    2005-12-15

    Acute aortic syndromes (AAS) encompass a spectrum of emergencies. These include those non-traumatic disease entities of the aorta namely, penetrating atherosclerotic ulcer, intramural haematoma, dissection and aneurysm rupture. The various types of AAS cannot be reliably differentiated on clinical grounds alone. Acute thoracic aortic injury is usually included in this group even though clinical presentation is different, i.e., in the context of trauma, the imaging features are very similar. Differentiation of AAS from acute coronary syndrome (ACS) is important, however, it must be remembered that ACS may occur as a result of AAS. Now electrocardiogram (ECG)-gating technology is widely available, ECG-gated multi-detector row computed tomography (MDCT) is a powerful clinical tool in the acute emergency setting, which enables rapid and specific diagnosis of aortic pathology. ECG-gated MDCT significantly reduces motion artefact, avoids potential pitfalls in diagnosis and often provides diagnostic information about the coronary arteries. It should be used as a first-line imaging technique. This article examines the role of MDCT imaging and cardiac gating in the assessment of AAS and discusses the differentiation of this spectrum of aortic diseases with reference to the key imaging findings as obtained by experience in our institution.

  7. Contrast-enhanced angiographic cone-beam computed tomography without pre-diluted contrast medium

    Energy Technology Data Exchange (ETDEWEB)

    Jo, K.I.; Kim, S.R.; Choi, J.H.; Kim, K.H.; Jeon, P. [Sungkyunkwan University School of Medicine, Department of Radiology, Samsung Medical Center, Gangnam-gu, Seoul (Korea, Republic of)

    2015-11-15

    Contrast-enhanced cone-beam computed tomography (CBCT) has been introduced and accepted as a useful technique to evaluate delicate vascular anatomy and neurovascular stents. Current protocol for CBCT requires quantitative dilution of contrast medium to obtain adequate quality images. Here, we introduce simple methods to obtain contrast-enhanced CBCT without quantitative contrast dilution. A simple experiment was performed to estimate the change in flow rate in the internal carotid artery during the procedure. Transcranial doppler (TCD) was used to evaluate the velocity change before and after catheterization and fluid infusion. In addition, 0.3 cm{sup 3}/s (n = 3) and 0.2 cm{sup 3}/s (n = 7) contrast infusions were injected and followed by saline flushes using a 300 mmHg pressure bag to evaluate neurovascular stent and host arteries. Flow velocities changed -15 ± 6.8 % and +17 ± 5.5 % from baseline during catheterization and guiding catheter flushing with a 300 mmHg pressure bag, respectively. Evaluation of the stents and vascular structure was feasible using this technique in all patients. Quality assessment showed that the 0.2 cm{sup 3}/s contrast infusion protocol was better for evaluating the stent and host artery. Contrast-enhanced CBCT can be performed without quantitative contrast dilution. Adequate contrast dilution can be achieved with a small saline flush and normal blood flow. (orig.)

  8. Magnetic resonance imaging and multi-detector computed tomography assessment of extracellular compartment in ischemic and non-ischemic myocardial pathologies

    Institute of Scientific and Technical Information of China (English)

    Maythem; Saeed; Steven; W; Hetts; Robert; Jablonowski; Mark; W; Wilson

    2014-01-01

    Myocardial pathologies are major causes of morbidity and mortality worldwide. Early detection of loss of cellular integrity and expansion in extracellular volume(ECV) in myocardium is critical to initiate effective treatment. The three compartments in healthy myocardium are: intravascular(approximately 10% of tissue volume), interstitium(approximately 15%) and intracellular(approximately 75%). Myocardial cells, fibroblasts and vascular endothelial/smooth muscle cells represent intracellular compartment and the main proteins in the interstitium are types Ⅰ/Ⅲ collagens. Microscopic studies have shown that expansion of ECV is an important feature of diffuse physiologic fibrosis(e.g., aging and obesity) and pathologic fibrosis [heart failure, aortic valve disease, hypertrophic cardiomyopathy, myocarditis, dilated cardiomyopathy, amyloidosis, congenital heart disease, aortic stenosis, restrictive cardiomyopathy(hypereosinophilic and idiopathic types), arrythmogenic right ventricular dysplasia and hypertension]. This review addresses recent advances in measuring of ECV in ischemic and non-ischemic myocardial pathologies. Magnetic resonance imaging(MRI) has the ability to characterize tissue proton relaxation times(T1, T2, and T2*). Proton relaxation times reflect the physical and chemical environments of water protons in myocardium. Delayed contrast enhanced-MRI(DE-MRI) and multi-detector computed tomography(DE-MDCT) demonstrated hyper-enhanced infarct, hypo-enhanced microvascular obstruction zone and moderately enhanced peri-infarct zone, but are limited for visualizing diffuse fibrosis and patchy microinfarct despite the increase in ECV. ECV can be measured on equilibrium contrast enhanced MRI/MDCT and MRI longitudinal relaxation time mapping. Equilibrium contrast enhanced MRI/MDCT and MRI T1 mapping is currently used, but at a lower scale, as an alternative to invasive sub-endomyocardial biopsies to eliminate the need for anesthesia, coronary catheterization and

  9. Scoliotic Change in Patients Having Undergone a Mastectomy: Analysis Using Multi-Detector Computed Tomography

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Moo Sang; Kim, Hye Won; Juhng, Seon Kwan; Choi, Si Sung [Dept. of Radiology, Wankwang University School of Medicine, Iksan (Korea, Republic of)

    2011-09-15

    To evaluate the relationship between the degree of scoliotic curvature and postoperative change of the chest wall among patients who underwent a unilateral mastectomy. Subjects were comprised of 56 women who underwent chest CT and a whole spine standing anteroposterior view (WSSAP). Cobb's angle and each side of the chest wall volume, including the breast, were measured with the WSSAP and a 3-D reconstructed multi-detector computed tomography (MDCT) image. A correlation analysis was performed between the scoliotic curvature and chest wall volume asymmetry. Directional correspondence between development of scoliosis and undergoing a mastectomy was analyzed. Furthermore, a survey on patient shoulder function was performed using a questionnaire and a correlation was performed between the results of the survey and the scoliotic curvature and chest wall volume asymmetry. The findings indicate that Cobb's angles were 4.4 degree {+-} 2.7 (Mean {+-} SD, range from 0.6 to 11.4). Differences in chest wall volume were 474.64 {+-} 276.36 cm{sup 3} (Mean {+-} SD, range from 78 to 1379). No statistical significance was noted between the degree of scoliotic curvature and chest wall volume asymmetry (p > 0.05). A cross-tabulation analysis of the direction between the scoliotic curvature and mastectomy was found to be statistically significant (p < 0.001). Also, there was a significant correlation between shoulder function assessment score and the degree of scoliotic curvature (p = 0.003), while no significant correlation between shoulder function assessment score and chest wall volume asymmetry (p 0.091) could be found. Scoliotic change had a tendency to be on the opposite side of the mastectomy and had no statistically significant relationship with the volume asymmetry. Thus, 3-D reconstructed MDCT images are helpful in differentiating selective volume differences.

  10. Imaging features of solid pseudopapillary tumor of the pancreas on multi-detector row computed tomography

    Institute of Scientific and Technical Information of China (English)

    Deng-Bin Wang; Qing-Bing Wang; Wei-Min Chai; Ke-Min Chen; Xia-Xing Deng

    2009-01-01

    AIM:To retrospectively analyze the imaging features of solid-pseudopapillary tumors (SPTs) of the pancreas on multi-detector row computed tomography (MDCT) and define the imaging findings suggestive of malignant potential.METHODS: A total of 24 consecutive cases with surgically and pathologically confirmed SPTs of the pancreas underwent preoperative abdominal MDCT studies in our hospital. All axial CT images, CT angiographic images, and coronally and sagittally reformed images were obtained. The images were retrospectively reviewed at interactive picture archiving and communication system workstations. RESULTS: Of the 24 cases of SPTs, 11 cases (45.8%) occurred in the pancreatic head and seven (29.1%) in the tail. Eighteen were pathologically diagnosed as benign and six as malignant. MDCT diagnosis of SPTs was well correlated with the surgical and pathological results (Kappa = 0.6, P < 0.05). The size of SPTs ranged from 3 to 15 cm (mean, 5.8 cm). When the size of the tumor was greater than 6 cm (including 6cm), the possibilities of vascular (8 vs 1) and capsular invasion (9 vs 0) increased significantly ( P < 0.05). Two pathologically benign cases with vascular invasion and disrupted capsule on MDCT presented with local recurrence and hepatic metastases during follow-up about 1 year after the resection of the primary tumors.CONCLUSION: Vascular and capsular invasion with superimposed spread into the adjacent pancreatic parenchyma and nearby structures in SPTs of the pancreas can be accurately revealed by MDCTpreoperatively. These imaging findings are predictive of the malignant potential associated with the aggressive behavior of the tumor, even in the pathologically benign cases.

  11. Iomeprol versus iopamidol in contrast-enhanced computed tomography of thoracic and abdominal organs.

    Science.gov (United States)

    Valentini, A L; Tartaglione, T; Monti, L; Marano, P

    1994-05-01

    The aim of this double-blind, parallel-group study was to compare the safety, tolerance, and efficacy of iomeprol-350 (350 mgI/ml), iomeprol-400 (400 mgI/ml) and iopamidol-370 (370 mgI/ml) for use in contrast-enhanced body computed tomography (CT). Following written informed consent, 120 adult inpatients of either sex requiring CT of thoracic or abdominal organs were randomly assigned to receive iomeprol-350, iomeprol-400 or iopamidol-370. Pre- and post-contrast, all patients underwent clinical, instrumental and laboratory investigation to assess the safety of the test agents. Tolerance was assessed in terms of discomfort associated with contrast injection. Two experienced radiologists independently and blindly graded the quality of contrast enhancement obtained with the different contrast solutions by means of a five-point ordinal scale as follows: 1, insufficient; 2, sufficient; 3, good; 4, excellent; or E, excessive. Patients in the iomeprol groups needed fewer injections and a smaller volume of contrast medium to obtain examinations of adequate diagnostic quality. Contrast enhancement was judged as excellent or good in about 90% of the study examinations, without significant differences between the three study groups. During contrast injection, heat and pain sensations were minimal or absent in most cases. No serious adverse events occurred throughout the study. No significant changes in clinical, instrumental or laboratory safety parameters were observed. In conclusion, iomeprol-400 and iomeprol-350 appear to be contrast solutions at least as safe, well tolerated and effective as iopamidol-370 when used as contrast agents for body CT.

  12. MULTI - DETECTOR COMPUTED TOMOGRAPHY AND INTRA - OPERATIVE CORRELATION IN BLUNT ABDOMINAL TRAUMA

    Directory of Open Access Journals (Sweden)

    Rakesh

    2014-01-01

    Full Text Available BACKGROUND : With the change in the pace of life fast , faster , fastest being the motto of the present day , the incidence of trauma and the associated mortality and morbidities is on a continuous rise.Imaging plays a very important role in the management of these injuries in deciding which injuries , in trauma the final verdict of organ injury in abdomen is intra - ope rative findings. AIMS : In view of the above said we considered to study to determine diagnostic accuracy of MDCT (Multi - Detector Computed Tomography in detection of intra - abdominal solid organ injury in blunt abdominal trauma and to highlight the importance of MDCT in evaluation of blunt abdominal trauma. METHODS AND MATERIALS : This was a prospective study done between over a period of 2 years from between January 2011 to February 2013 on patients who presented with blun t abdominal trauma after excluding patients who were managed conservatively and normal on imaging , the data we compared had 32 patients and the analysis was as follows. RESULTS : Blunt abdominal trauma was common in males , the male to female ratio was 9:1 , road traffic accident is the most common mode of injury in blunt abdominal trauma with 60% of the patients in this mode of injury , single organ injury is 22 patients (76% spleen is the most commonly injured organ 15(47% patients having splenic injury , wi th grade 3 being the commonest splenic injury 8 out of the 15 patients had splenic injury bowel injury was the second common organ injured in blunt trauma abdomen. In this study computed tomography grading correlated well with intra - operative grading with a PPV of= 95.45 % (95% ci: 84.50 % to 99.31 % Asensitivityof 76.36 % (95% ci: 62.98 % to 86.76 % . CONCLUSION : Computed tomography is an important imaging technique for diagnosis of organ injuries in patients with abdominal trauma. It helps in grading of the type of injury and accordingly deciding the management of patient. It is a highly

  13. Contrast-enhanced three-dimensional computed tomography of brain tumors

    Energy Technology Data Exchange (ETDEWEB)

    Kuroiwa, Toshihiko; Deguchi, Jun; Arai, Motohiro; Tanaka, Hideo; Ohta, Tomio; Narabayashi, Isamu [Osaka Medical Coll., Takatsuki (Japan)

    1997-12-01

    To evaluate the usefulness of contrast-enhanced spiral (helical) scanning computed tomography (CT) in patients with various brain tumors, a non ionic contrast medium was injected intravenously in ten patients with meningioma, five with vestibular schwannoma, and five with pituitary adenoma. Images were taken by spiral scan at an X-ray beam width of 1 or 2 mm. The volume data obtained were combined at 0.5-1 mm intervals for the three-dimensional (3-D) image reconstruction, by the volume rendering method. Each image was separated by CT number into bone, blood vessel, contrast-enhanced tumor, and cerebral parenchyma. In some subjects, a pair of images was reconstructed to allow stereoscopic viewing at a parallax angle of 6 degrees. Three-dimensional relationship between tumors and other structures was easily understood, permitting pre-operative prediction of the operative field and also a view of the area after tumor excision. The present method surpassed conventional CT techniques in terms of clarity of the 3-D relationship, and surpassed MRI and MRA in terms of clarity of relationship between the tumor and skull. These results confirm that this method appears to be applicable in routine clinical situations with minimal invasiveness, high degree of safety, and short examination time. (author)

  14. Sixty-four-multi-detector computed tomography diagnosis of coronary artery anomalies in 66 patients

    Institute of Scientific and Technical Information of China (English)

    YANG Shan; ZENG Meng-su; ZHANG Zhi-yong; LING Zhi-qing; MA Jian-ying; CHEN Gang

    2010-01-01

    Background The abnormalities of coronary arteries, though rare and sometimes benign, may first present clinically as myocardial infarction or sudden death. Multi-detector computed tomography (MDCT) is a non-invasive test that is highly suitable for detecting these anomalies. The study aimed to review the 64-MDCT appearance of the coronary artery anomalies in 66 patients and to discuss the clinical importance of these anomalies.Methods In 6014 consecutive patients examined over 12 months by 64-MDCT for the study of coronary artery disease, 66 were diagnosed for coronary artery anomalies. All patients were symptomatic for one or more of the following diseases: chest pain, dyspnoea, palpitations, arrhythmia and myocardial infarction. Nine patients had undergone a coronary angiography. All the CT images were evaluated by two radiologists and one cardiologist. The right coronary artery (RCA) and the conus branch arising separately, myocardial bridging and duplication of arteries were not analysed in our study.Results The incidence of coronary artery anomalies found in our study group was 1.097%. In the selected patients, seven different types of coronary anomalies were found by 64-MDCT examination. The high takeoff, origin of the coronary artery from the opposite or noncoronary sinus with an anomalous course, and coronary artery fistula were the three common forms of anomalies (n=16, 18 and 16, respectively). Compared with the results of the coronary angiography, the number of the drainage sites of two coronary artery fistula was less in MDCT images (3 small sites in total). In all cases, coronary artery computed tomography angiography (CTA) technique was able to recognize the origin of the coronary artery, its three-dimensional course and its spatial relationship with the adjacent structures. Conventional coronary angiography in two cases, however, was unable to provide sufficient information for correct and complete diagnosis.Conclusions In conclusion, the study

  15. True tracheal bronchus: Classification and anatomical relationship on multi-detector computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hyun Jeong; Kim, Young Tong; Jou, Sung Shick; Lee, Woong Hee [Dept. of Radiology, Soonchunhyang University Cheonan Hospital, Soonchunhyang University College of Medicine, Cheonan (Korea, Republic of)

    2017-04-15

    To propose the imaging classification of true tracheal bronchus (TTB) on multi-detector computed tomography (MDCT), and to evaluate its anatomical relationship with surrounding structures. This study included 44 patients who were diagnosed with TTB on MDCT for 6 years. We classified TTB into five types, based on the existence of the right upper lobe bronchus originating from the right main bronchus and the number of segmental bronchi of TTB. We analyzed the site of origin and the running direction of TTB based on its anatomical relationship with surrounding structures and some ancillary findings. The imaging classification of TTB included Type I (47.7%), Type II (13.6%), Type III (11.4%), Type IV (25.0%), and Type V (2.0%). According to the site of origin of TTB, below the aortic arch (52.3%) and at the level of the aortic arch (43.1%) were the two main sites of origin, whereas the frequency of the site of origin above the azygos arch, at the level of the azygos arch, and below the azygos arch was 27.3%, 38.6%, and 34.1%, respectively. Considering both aortic and azygos arches, below the aortic arch and below the azygos arch were the most common sites of origin (27.3%). With respect to the running direction of TTB, in all cases, TTB passed below the azygos arch to the right upper lobe. There was no statistically significant (p > 0.05) difference in age or sex between types of TTB. Ancillary findings included tracheal stenosis (n = 2), narrowing of the right main bronchus (n = 2), luminal narrowing of TTB and bronchiectasis at the distal portion (n = 1), and a highly located azygos arch above the aortic arch (n = 2). The proposed imaging classification of TTB and its anatomical relationship with surrounding structures will improve our understanding of various imaging features and embryological development of TTB. Radiologists should pay careful attention to evaluation of the airway including the trachea on thoracic imaging.

  16. When the non-contrast-enhanced phase is unnecessary in abdominal computed tomography scans? A retrospective analysis of 244 cases

    Energy Technology Data Exchange (ETDEWEB)

    Costa, Danilo Manuel Cerqueira; Salvadori, Priscila Silveira; Monjardim, Rodrigo da Fonseca; Bretas, Elisa Almeida Sathler; Torres, Lucas Rios; Caldana, Rogerio Pedreschi; Shigueoka, David Carlos; Medeiros, Regina Bitelli; D' ippolito, Giuseppe, E-mail: giuseppe_dr@uol.com.br [Universidade Federal de Sao Paulo (EPM/UNIFESP), Sao Paulo, SP (Brazil). Escola Paulista de Medicina. Departamento de Diagnostico por Imagem

    2013-06-15

    Objective: to evaluate the necessity of the non contrast-enhanced phase in abdominal computed tomography scans. Materials and Methods: A retrospective, cross-sectional, observational study was developed, evaluating 244 consecutive abdominal computed tomography scans both with and without contrast injection. Initially, the contrast-enhanced images were analyzed (first analysis). Subsequently, the observers had access to the non-contrast-enhanced images for a second analysis. The primary and secondary diagnoses were established as a function of the clinical indications for each study (such as tumor staging, acute abdomen, investigation for abdominal collection and hepatocellular carcinoma, among others). Finally, the changes in the diagnoses resulting from the addition of the non-contrast-enhanced phase were evaluated. Results: Only one (0.4%; p > 0.999; non-statistically significant) out of the 244 reviewed cases had the diagnosis changed after the reading of non-contrast-enhanced images. As the secondary diagnoses are considered, 35 (14%) cases presented changes after the second analysis, as follows: nephrolithiasis (10%), steatosis (3%), adrenal nodule (0.7%) and cholelithiasis (0.3%). Conclusion: For the clinical indications of tumor staging, acute abdomen, investigation of abdominal collections and hepatocellular carcinoma, the non-contrast-enhanced phase can be excluded from abdominal computed tomography studies with no significant impact on the diagnosis. (author)

  17. When the non-contrast-enhanced phase is unnecessary in abdominal computed tomography scans? A retrospective analysis of 244 cases

    Directory of Open Access Journals (Sweden)

    Danilo Manuel Cerqueira Costa

    2013-07-01

    Full Text Available Objective: To evaluate the necessity of the non contrast-enhanced phase in abdominal computed tomography scans. Materials and Methods: A retrospective, cross-sectional, observational study was developed, evaluating 244 consecutive abdominal computed tomography scans both with and without contrast injection. Initially, the contrast-enhanced images were analyzed (first analysis. Subsequently, the observers had access to the non-contrast-enhanced images for a second analysis. The primary and secondary diagnoses were established as a function of the clinical indications for each study (such as tumor staging, acute abdomen, investigation for abdominal collection and hepatocellular carcinoma, among others. Finally, the changes in the diagnoses resulting from the addition of the non-contrast-enhanced phase were evaluated. Results: Only one (0.4%; p > 0.999; non-statistically significant out of the 244 reviewed cases had the diagnosis changed after the reading of non-contrast-enhanced images. As the secondary diagnoses are considered, 35 (14% cases presented changes after the second analysis, as follows: nephrolithiasis (10%, steatosis (3%, adrenal nodule (0.7% and cholelithiasis (0.3%. Conclusion: For the clinical indications of tumor staging, acute abdomen, investigation of abdominal collections and hepatocellular carcinoma, the non-contrast-enhanced phase can be excluded from abdominal computed tomography studies with no significant impact on the diagnosis.

  18. A method for coronary artery calcium scoring using contrast-enhanced computed tomography

    DEFF Research Database (Denmark)

    Otton, James M; Lønborg, Jacob T; Boshell, David;

    2012-01-01

    Limitations to the coronary calcium score include its requirement for noncontrast imaging and radiation exposure that approaches current methods for contrast-enhanced CT angiography.......Limitations to the coronary calcium score include its requirement for noncontrast imaging and radiation exposure that approaches current methods for contrast-enhanced CT angiography....

  19. Intensive-care unit lung infections: The role of imaging with special emphasis on multi-detector row computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Romano, Luigia; Pinto, Antonio; Merola, Stefanella; Gagliardi, Nicola; Tortora, Giovanni [Department of Diagnostic Imaging, Cardarelli Hospital, Naples Italy-Via G. Merliani 31, 80127 Naples (Italy); Scaglione, Mariano [Department of Diagnostic Imaging, Cardarelli Hospital, Naples Italy-Via G. Merliani 31, 80127 Naples (Italy)], E-mail: mscaglione@tiscali.it

    2008-03-15

    Nosocomial pneumonia is the most frequent hospital-acquired infection. In mechanically ventilated patients admitted to an intensive-care unit as many as 7-41% may develop pneumonia. The role of imaging is to identify the presence, location and extent of pulmonary infection and the presence of complications. However, the poor resolution of bedside plain film frequently limits the value of radiography as an accurate diagnostic tool. To date, multi-detector row computed tomography with its excellent contrast resolution is the most sensitive modality for evaluating lung parenchyma infections.

  20. Mapping epicardial fat with multi-detector computed tomography to facilitate percutaneous transepicardial arrhythmia ablation

    Energy Technology Data Exchange (ETDEWEB)

    Abbara, Suhny [Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA (United States)]. E-mail: Sabbara@partners.org; Desai, Jay C. [Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA (United States); Cury, Ricardo C. [Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA (United States); Butler, Javed [Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA (United States); Nieman, Koen [Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA (United States); Reddy, Vivek [Division of Cardiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA (United States)

    2006-03-15

    A sizable portion of ventricular tachycardia circuits are epicardial, especially in patients with non-ischemic cardiomyopathy, e.g. Chagas disease. Thus there is a growing interest among the electrophysiologists in transepicardial mapping and myocardial ablation for treatment of arrhythmias. However, increased epicardial fat can be a significant hindrance in procedural success as it can mimic infarct during mapping and can also decrease the effectiveness of ablation. Quantitative knowledge of epicardial fat pre-procedure can potentially significantly facilitate the conduct and outcomes of these procedures. In this study we assessed the epicardial fat distribution and thickness in vivo in 59 patients who underwent multi-detector computed tomography (MDCT) for coronary artery assessment using a 16-slice scanner. Multiplanar reconstructions were obtained in the ventricular short axis at the basal, mid ventricular, and near the apex level, and in a four-chamber view. In the short axis slices, we measured epicardial fat diameter in nine segments, and in the four-chamber view, it was measured in five segments. In grooved segments the maximum fat thickness was recorded, while in non-grooved segments thickness at three equally spaced points were averaged. The results were as follows starting clockwise: superior inter-ventricular (IV) groove (all measurements are in mm, in basal, mid ventricular, and apical levels, respectively) (11.2, 8.6, 7.3), left ventricular (LV) superior lateral wall (1.0, 1.5, 1.7), LV inferior lateral wall (1.3, 2.2, 3.5), inferior IV groove (9.2, 6.5, 6.1), right ventricular (RV) diaphragmatic wall (1.4, 0.2, 1.0), acute margin (9.2, 7.3, 7.8), RV anterior free wall inferior (6.8, 4.0, 4.7), RV anterior free wall superior (6.5, 3.2, 3.1), RV superior wall (5.6, 2.7, 4.0), We measured the following four-chamber segments: LV apex (2.8 mm), left atrio-ventricular (AV) groove (12.7), right AV groove (14.8), RV apex (4.8), and anterior IV groove (7

  1. Autoimmune pancreatitis: Assessment of the enhanced duct sign on multiphase contrast-enhanced computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Kawai, Yuichi, E-mail: kawai.yuichi@a.mbox.nagoya-u.ac.jp [Department of Radiology, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya 466-8550 (Japan); Suzuki, Kojiro, E-mail: kojiro@med.nagoya-u.ac.jp [Department of Radiology, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya 466-8550 (Japan); Itoh, Shigeki, E-mail: shigeito@nagoya-1st.jrc.or.jp [Department of Diagnostic Radiology, Japan Red Cross Nagoya Daiichi Hospital, 3-35 Michishita-cho, Nakamura-ku, Nagoya 453-8511 (Japan); Takada, Akira, E-mail: takadaa@med.nagoya-u.ac.jp [Department of Radiology, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya 466-8550 (Japan); Mori, Yoshine, E-mail: yoshine@med.nagoya-u.ac.jp [Department of Radiology, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya 466-8550 (Japan); Naganawa, Shinji, E-mail: naganawa@med.nagoya-u.ac.jp [Department of Radiology, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya 466-8550 (Japan)

    2012-11-15

    Purpose: To assess the usefulness of the computed tomography (CT) finding of main pancreatic duct (MPD) wall enhancement, termed the 'enhanced duct sign', for diagnosis of autoimmune pancreatitis (AIP) in comparison with diagnosis of pancreatic carcinoma and chronic pancreatitis. Materials and methods: Two radiologists independently evaluated the presence or absence of the enhanced duct sign on multiphase contrast-enhanced CT in patients with AIP (n = 55), pancreatic carcinoma (n = 50), and chronic pancreatitis (n = 50). The sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of AIP were calculated. In patients demonstrating the enhanced duct sign, additional findings were evaluated by consensus. Results: The enhanced duct sign was more frequently observed in patients with AIP (37/55, 67%) than in patients with pancreatic carcinoma (5/50, 10%) or chronic pancreatitis (0/50, 0%) (P < 0.05). The sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of the finding were 0.67, 0.95, 0.85, 0.88, and 0.84, respectively. In AIP, the lumen within the enhanced duct was completely or partially invisible in 29 of 37 (78%) patients, and the enhanced duct was observed within the affected pancreatic parenchyma in 35 of 37 (95%) patients. In pancreatic carcinoma, the lumen within the enhanced duct was visible in all patients (5/5, 100%), and the enhanced duct was observed downstream of the tumor (5/5, 100%). Conclusion: The enhanced duct sign is highly specific of AIP.

  2. Intravenous contrast enhanced computed tomography colonoscopy in children with suspected colonic polyps

    Energy Technology Data Exchange (ETDEWEB)

    Bhatia, Anmol, E-mail: anmol_bhatia26@yahoo.co.in [Department of Radiodiagnosis and Imaging, Post Graduate Institute of Medical Education and Research, Sector-12, Chandigarh 160 012 (India); Saxena, Akshay K., E-mail: fatakshay@yahoo.com [Department of Radiodiagnosis and Imaging, Post Graduate Institute of Medical Education and Research, Sector-12, Chandigarh 160 012 (India); Kalra, Naveen, E-mail: navkal2004@yahoo.com [Department of Radiodiagnosis and Imaging, Post Graduate Institute of Medical Education and Research, Sector-12, Chandigarh 160 012 (India); Sodhi, Kushaljit S., E-mail: sodhiks@gmail.com [Department of Radiodiagnosis and Imaging, Post Graduate Institute of Medical Education and Research, Sector-12, Chandigarh 160 012 (India); Thapa, Babu R., E-mail: brthapa1@yahoo.co.in [Division of Pediatric Gastroenterology, Department of Gastroenterology, Post Graduate Institute of Medical Education and Research, Sector-12, Chandigarh 160 012 (India); Rao, Katragadda L.N., E-mail: klnrao@hotmail.com [Department of Pediatric Surgery, Post Graduate Institute of Medical Education and Research, Sector-12, Chandigarh 160 012 (India); Khandelwal, Niranjan, E-mail: khandelwaln@hotmail.com [Department of Radiodiagnosis and Imaging, Post Graduate Institute of Medical Education and Research, Sector-12, Chandigarh 160 012 (India)

    2013-06-15

    Objective: The purpose of this study was to evaluate the diagnostic performance of intravenous contrast enhanced computed tomographic colonoscopy (IVCTC) in the diagnosis of clinically suspected colorectal polyps in children, using conventional colonoscopy (CC) as the gold standard. Methods: This was a prospective study conducted between July 2008 and June 2010. 30 pediatric patients with history of rectal bleeding and clinically suspected to have colorectal polyps were enrolled. All of the patients underwent IVCTC followed by CC. 30 IVCTC and 31 CC were performed in 30 patients. The findings of IVCTC were compared with those of CC. Statistical analysis was performed to obtain diagnostic performance values of IVCTC on per polyp (sensitivity and positive predictive value) and per patient (sensitivity, specificity, positive predictive value and negative predictive value) basis. Results: By IVCTC, 63 polyps were detected in 28 patients of which 53 polyps were eligible for inclusion in the statistical analysis. 60 polyps were detected by CC in 28 patients of which 50 polyps were eligible for inclusion in the statistical analysis. The per polyp sensitivity and positive predictive values were 94% and 88.6% respectively. The per patient sensitivity, specificity, positive predictive value, and negative predictive values were 96.4, 50, 96.4, and 50% respectively. Twenty polyps, in 10 patients, were visualized only after intravenous contrast administration of which 5 polyps, in 5 patients, were likely to have been missed in the absence of the intravenous contrast injection as these polyps were submerged in fluid. Four patients would have had a false negative CTC examination if the intravenous contrast had not been injected; while in another patient, the number of polyps would have been underestimated. Conclusion: CTC is capable of serving as a safe and efficient non-invasive tool for evaluating children with clinically suspected colorectal polyps. Administration of

  3. Acute kidney injury in cirrhotic patients undergoing contrast-enhanced computed tomography

    Science.gov (United States)

    Filomia, Roberto; Maimone, Sergio; Caccamo, Gaia; Saitta, Carlo; Visconti, Luca; Alibrandi, Angela; Caloggero, Simona; Bottari, Antonio; Franzè, Maria Stella; Gambino, Carmine Gabriele; Lembo, Tindaro; Oliva, Giovanni; Cacciola, Irene; Raimondo, Giovanni; Squadrito, Giovanni

    2016-01-01

    Abstract Contrast medium administration is one of the leading causes of acute kidney injury (AKI) in different clinical settings. The aim of the study was to investigate occurrence and predisposing factors of AKI in cirrhotic patients undergoing contrast-enhanced computed tomography (CECT). Datasets of 1279 consecutively hospitalized cirrhotic patients were retrospectively analyzed. Two hundred forty-nine of 1279 patients (mean age 64 ± 11 years, 165 male) who had undergone CECT were selected on the basis of the availability of serum creatinine (sCr) values evaluated before and after CECT (CECT group). In analogy, 203/1279 cases (mean age 66 ± 10 years, 132 male) who had not undergone CECT and had been tested twice for sCr in 7 days were also included as controls (Control group). AKI network criteria were employed to assess contrast-induced AKI (CI-AKI) development. Apart from lack of narrowed double sCr measurements, additional exclusion criteria were active bacterial infections, nephrotoxic drugs intake, and estimated glomerular filtration rate sCr values (OR: 0.124, 95% CI: 0.016–0.975; P = 0.047). In the CECT group, presence of ascites (OR: 2.796, 95% CI: 1.109–7.052; P = 0.029), female sex (OR: 0.192, 95% CI: 0.073–0.510; P = 0.001), and hyperazotemia (OR: 1.018, 95% CI: 1.001–1.037; P = 0.043) correlated with CI-AKI development at multivariate analysis. CI-AKI is a quite frequent occurrence in cirrhotic patients with female sex, presence of ascites, and hyperazotemia being the predisposing factors. PMID:27661025

  4. Assessment of left ventricular ejection fraction: comparison of two dimensional echocardiography, cardiac magnetic resonance imaging and 64-row multi-detector computed tomography

    Institute of Scientific and Technical Information of China (English)

    Chee Khoon LIEW; Kui Hian SIM; Rapaee ANNUAR; Tiong Kiam ONG; Sze Piaw CHIN; Tobias Seyfarth; Yean Yip FONG; Wei Ling CHAN; Choon Kiat ANG; Houng Bang LIEW

    2006-01-01

    Objectives To compare left ventricular ejection fraction (LVEF) determined from 64-row multi-detector computed tomography (64-row MDCT) with those determined from two dimensional echocardiography (2D echo) and cardiac magnetic resonance imaging (CMR). Methods Thirty-two patients with coronary artery disease underwent trans-thoracic 2D echo, CMR and contrast-enhanced 64-row MDCT for assessment of LVEF within 48 hours of each other. 64-row MDCT LVEF was derived using the Syngo Circulation software; CMR LVEF was by Area Length Ejection Fraction (ALEF) and Simpson method and 2D echo LVEF by Simpson method.Results The LVEF was 49.13 ± 15.91% by 2D echo, 50.72 ± 16.55% (ALEF method) and 47.65 ± 16.58%(Simpson method) by CMR and 50.00 ± 15.93% by 64-row MDCT. LVEF measurements by 64-row MDCT correlated well with LVEF measured with CMR using either the ALEF method (Pearson correlation r = 0.94, P <0.01) or Simpson method (r = 0.92, P<0.01). It also correlated well with LVEF measured using 2D echo (r = 0.80, P < 0.01). Conclusion LVEF measurements by 64-row MDCT correlated well with LVEF measured by CMR and 2D echo. The correlation between 64-row MDCT and CMR was better than the correlation between 2D echo with CMR. Standard data set from a 64-row MDCT coronary study can be reliably used to calculate the LVEF.

  5. Differential Diagnosis of Solitary Pulmonary Inflammatory Lesions and Peripheral Lung Cancers with Contrast-enhanced Computed Tomography

    Science.gov (United States)

    Chu, Zhi-gang; Sheng, Bo; Liu, Meng-qi; Lv, Fa-jin; Li, Qi; Ouyang, Yu

    2016-01-01

    OBJECTIVES: To clarify differences between solitary pulmonary inflammatory lesions and peripheral lung cancers with contrast-enhanced computed tomography. METHODS: In total, 64 and 132 patients with solitary pulmonary inflammatory masses/nodules and peripheral lung cancers, respectively, were enrolled in this study. Their computed tomographic findings were summarized and compared retrospectively. RESULTS: Compared with the peripheral lung cancers, the inflammatory lesions were located closer to the pleura (pmanagement.

  6. Diagnostic accuracy of contrast-enhanced computed tomography and contrast-enhanced magnetic resonance imaging of small renal masses in real practice: sensitivity and specificity according to subjective radiologic interpretation.

    Science.gov (United States)

    Kim, Jae Heon; Sun, Hwa Yeon; Hwang, Jiyoung; Hong, Seong Sook; Cho, Yong Jin; Doo, Seung Whan; Yang, Won Jae; Song, Yun Seob

    2016-10-12

    The aim of this study was to investigate the diagnostic accuracy of contrast-enhanced computed tomography (CT) and contrast-enhanced magnetic resonance imaging (MRI) of small renal masses in real practice. Contrast-enhanced CT and MRI were performed between February 2008 and February 2013 on 68 patients who had suspected small (≤4 cm) renal cell carcinoma (RCC) based on ultrasonographic measurements. CT and MRI radiographs were reviewed, and the findings of small renal masses were re-categorized into five dichotomized scales by the same two radiologists who had interpreted the original images. Receiver operating characteristics curve analysis was performed, and sensitivity and specificity were determined. Among the 68 patients, 60 (88.2 %) had RCC and eight had benign disease. The diagnostic accuracy rates of contrast-enhanced CT and MRI were 79.41 and 88.23 %, respectively. Diagnostic accuracy was greater when using contrast-enhanced MRI because too many masses (67.6 %) were characterized as "4 (probably solid cancer) or 5 (definitely solid cancer)." The sensitivity of contrast-enhanced CT and MRI for predicting RCC were 79.7 and 88.1 %, respectively. The specificities of contrast-enhanced CT and MRI for predicting RCC were 44.4 and 33.3 %, respectively. Fourteen diagnoses (20.5 %) were missed or inconsistent compared with the final pathological diagnoses. One appropriate nephroureterectomy and five unnecessary percutaneous biopsies were performed for RCC. Seven unnecessary partial nephrectomies were performed for benign disease. Although contrast-enhanced CT and MRI showed high sensitivity for detecting small renal masses, specificity remained low.

  7. Posterior Urethra Rupture: Contrast-Enhanced Computed Tomography Scan and Urethrocystography Demonstrations

    Directory of Open Access Journals (Sweden)

    Wojciech Marks

    2012-01-01

    Full Text Available In the follow-up study of patients with pelvic fractures, rupture of the posterior urethra is registered in 3–25% of cases (Koraitim et al., 1996. The diagnostic gold standard for the assessment of hemodynamically stable trauma patients is contrast-enhanced CT scan, especially helical CT. Nevertheless, simultaneous suprapubic cystography and ascending urethrograms (the so-called up-and-downogram are the investigation of choice in assessing the site, severity, and length of urethral injuries. (Carlin and Resnick, 1995 This paper discusses the evaluation and diagnosis of urethral injury in multiple-trauma patient.

  8. Contrast-enhanced ultrasound vs multidetector-computed tomography for detecting liver metastases in colorectal cancer: a prospective, blinded, patient-by-patient analysis

    DEFF Research Database (Denmark)

    Rafaelsen, S R; Jakobsen, A

    2011-01-01

    This study compared the sensitivity and specificity of contrast-enhanced ultrasound (CEUS) and multidetector-computed tomography (MDCT) in the detection of liver metastases in patients with colorectal cancer.......This study compared the sensitivity and specificity of contrast-enhanced ultrasound (CEUS) and multidetector-computed tomography (MDCT) in the detection of liver metastases in patients with colorectal cancer....

  9. Thoracic Injuries in earthquake-related versus non-earthquake-related trauma patients: differentiation via Multi-detector Computed Tomography

    Directory of Open Access Journals (Sweden)

    Zhi-hui Dong

    2011-01-01

    Full Text Available PURPOSE: Massive earthquakes are harmful to humankind. This study of a historical cohort aimed to investigate the difference between earthquake-related crush thoracic traumas and thoracic traumas unrelated to earthquakes using a multi-detector Computed Tomography (CT. METHODS: We retrospectively compared an earthquake-exposed cohort of 215 thoracic trauma crush victims of the Sichuan earthquake to a cohort of 215 non-earthquake-related thoracic trauma patients, focusing on the lesions and coexisting injuries to the thoracic cage and the pulmonary parenchyma and pleura using a multi-detector CT. RESULTS: The incidence of rib fracture was elevated in the earthquake-exposed cohort (143 vs. 66 patients in the non-earthquake-exposed cohort, Risk Ratio (RR = 2.2; p<0.001. Among these patients, those with more than 3 fractured ribs (106/143 vs. 41/66 patients, RR=1.2; p<0.05 or flail chest (45/143 vs. 11/66 patients, RR=1.9; p<0.05 were more frequently seen in the earthquake cohort. Earthquake-related crush injuries more frequently resulted in bilateral rib fractures (66/143 vs. 18/66 patients, RR= 1.7; p<0.01. Additionally, the incidence of non-rib fracture was higher in the earthquake cohort (85 vs. 60 patients, RR= 1.4; p<0.01. Pulmonary parenchymal and pleural injuries were more frequently seen in earthquake-related crush injuries (117 vs. 80 patients, RR=1.5 for parenchymal and 146 vs. 74 patients, RR = 2.0 for pleural injuries; p<0.001. Non-rib fractures, pulmonary parenchymal and pleural injuries had significant positive correlation with rib fractures in these two cohorts. CONCLUSIONS: Thoracic crush traumas resulting from the earthquake were life threatening with a high incidence of bony thoracic fractures. The ribs were frequently involved in bilateral and severe types of fractures, which were accompanied by non-rib fractures, pulmonary parenchymal and pleural injuries.

  10. Contrast enhanced ultrasound in the assessment of urogenital pathology

    Directory of Open Access Journals (Sweden)

    Libero Barozzi

    2014-12-01

    Full Text Available Contrast enhanced ultrasound (CEUS is an innovative technique that employs microbubble contrast agents to demonstrate parenchymal perfusion. Although initial clinical application was focused on the liver pathology, a wide variety of clinical conditions can be assessed now with CEUS. CEUS is a well-tolerated technique and is acquiring an increasing role in the assessment of renal pathology because contrast agents are not excreted by the kidney and do not affect the renal function. CEUS demonstrated an accuracy similar to contrast enhanced multi-detector computed tomography (CEMDCT in detecting focal lesions, with the advantage of the real-time assessment of microvascular perfusion by using time-intensity curves. The aim of this paper is to review the main indications of CEUS in the assessment of renal and urogenital pathology. Imaging examples are presented and described. Advantages and limitations of CEUS with reference to conventional US and CE-MDCT are discussed.

  11. Computer-aided detection of bladder mass within non-contrast-enhanced region of CT Urography (CTU)

    Science.gov (United States)

    Cha, Kenny H.; Hadjiiski, Lubomir M.; Chan, Heang-Ping; Caoili, Elaine M.; Cohan, Richard H.; Weizer, Alon; Zhou, Chuan

    2016-03-01

    We are developing a computer-aided detection system for bladder cancer in CT urography (CTU). We have previously developed methods for detection of bladder masses within the contrast-enhanced region of the bladder. In this study, we investigated methods for detection of bladder masses within the non-contrast enhanced region. The bladder was first segmented using a newly developed deep-learning convolutional neural network in combination with level sets. The non-contrast-enhanced region was separated from the contrast-enhanced region with a maximum-intensityprojection- based method. The non-contrast region was smoothed and a gray level threshold was employed to segment the bladder wall and potential masses. The bladder wall was transformed into a straightened thickness profile, which was analyzed to identify lesion candidates as a prescreening step. The lesion candidates were segmented using our autoinitialized cascaded level set (AI-CALS) segmentation method, and 27 morphological features were extracted for each candidate. Stepwise feature selection with simplex optimization and leave-one-case-out resampling were used for training and validation of a false positive (FP) classifier. In each leave-one-case-out cycle, features were selected from the training cases and a linear discriminant analysis (LDA) classifier was designed to merge the selected features into a single score for classification of the left-out test case. A data set of 33 cases with 42 biopsy-proven lesions in the noncontrast enhanced region was collected. During prescreening, the system obtained 83.3% sensitivity at an average of 2.4 FPs/case. After feature extraction and FP reduction by LDA, the system achieved 81.0% sensitivity at 2.0 FPs/case, and 73.8% sensitivity at 1.5 FPs/case.

  12. Discordant findings of dimercaptosuccinic acid scintigraphy in children with multi-detector row computed tomography-proven acute pyelonephritis

    Directory of Open Access Journals (Sweden)

    Jeongmin Lee

    2011-05-01

    Full Text Available Purpose : The diagnosis of acute pyelonephritis (APN is often difficult, as its clinical and biological manifestations are non-specific in children. If not treated quickly and adequately, however, APN may cause irreversible renal damage, possibly leading to hypertension and chronic renal failure. We were suspecting the diagnostic value of 99mTc-dimercaptosuccinic acid (DMSA scan by experiences and so compared the results of DMSA scan to those of multi-detector row computed tomography (MDCT. Methods : We retrospectively selected and analyzed 81 patients who were diagnosed as APN by MDCT during evaluation of their acute abdomen in emergency room and then received DMSA scan also for the diagnostic work-up of APN after admission. We evaluated the results of imaging studies and compared the diagnostic value of each method by age groups, &lt;2 years (n=45 and ?#242; years (n=36. Results : Among total 81 patients with MDCT-proven APN, DMSA scan was diagnostic only in 55 children (68%, while the remaining 26 children (32% showed false negative normal findings. These 26 patients were predominantly male and most of them, 19 (73.1% were &lt;2 years of age. Conclusion : DMSA scan holds obvious limitation compared to MDCT in depicting acute inflammatory lesions of kidney in children with APN, especially in early childhood less than 2 years of age. MDCT showed hidden lesions of APN, those were undetectable through DMSA scan in children.

  13. Clinical impact of hyperattenuation of adrenal glands on contrast-enhanced computed tomography of polytraumatised patients

    Energy Technology Data Exchange (ETDEWEB)

    Schek, J.; Klasen-Sansone, J.; Heusch, P.; Kroepil, P.; Antoch, G.; Lanzman, R.S. [University Dusseldorf, Medical Faculty, Department of Diagnostic and Interventional Radiology, Dusseldorf (Germany); Macht, S. [Radiologie Koeln-Nord, Koeln (Germany); Witte, I. [University Dusseldorf, Medical Faculty, Department of Trauma and Hand Surgery, Dusseldorf (Germany)

    2014-02-15

    To evaluate the prognostic value of hyperattenuating adrenal glands on contrast-enhanced CT of polytraumatised patients. Two hundred ninety-two patients (195 men and 97 women, mean age 45.3 ± 23.3 years) were included in this retrospective study. CT examinations were performed 60 s after intravenous injection of contrast material. Image analysis was performed by two radiologists. Patients were assigned to one of two groups according to the attenuation of the adrenal gland [group 1: adrenal glands ≥ inferior vena cava (IVC); group 2: adrenal glands < IVC]. Eighteen patients (42.2 years ± 24.2) were assigned to group 1 and 274 patients (48.4 years ± 22.4) to group 2. The average adrenal density was 150.8 ± 36.1 HU in group 1 and 83.7 ± 23.6 HU in group 2 (P < 0.0001). Eight of the 18 patients in group 1 (44.4 %) and 33 of the 274 patients in group 2 (12.4 %) died during hospitalisation (P < 0.05). Mean adrenal enhancement was significantly higher in patients who died (101.9 ± 40.6 HU) compared with survivors (86.1 ± 27.0 HU; P < 0.001). Hyperattenuation of adrenal glands is associated with a higher mortality rate in polytraumatised patients and may serve as a predictor of poor clinical outcome. (orig.)

  14. Myocardial physiology measurements using contrast enhanced dynamic computed tomography: simulation of beam hardening effect

    Science.gov (United States)

    Cao, Minsong; Stantz, Keith M.; Liang, Yun

    2006-03-01

    Initial animal study for quantifying myocardial physiology through contrast-enhanced dynamic x-ray CT suggested that beam hardening is one of the limiting factors for accurate regional physiology measurement. In this study, a series of simulations were performed to investigate its deterioration effects and two correction algorithms were adapted to evaluate for their efficiency in improving the measurements. The simulation tool consists of a module simulating data acquisition of a real polyenergetic scanner system and a heart phantom consisting of simple geometric objects representing ventricles and myocardium. Each phantom component was modeled with time-varying attenuation coefficients determined by ideal iodine contrast dynamic curves obtained from experimental data or simulation. A compartment model was used to generate the ideal myocardium contrast curve using physiological parameters consistent with measured values. Projection data of the phantom were simulated and reconstructed to produce a sequence of simulated CT images. Simulated contrast dynamic curves were fitted to the compartmental model and the resultant physiological parameters were compared with ideal values to estimate the errors induced by beam hardening artifacts. The simulations yielded similar deterioration patterns of contrast dynamic curves as observed in the initial study. Significant underestimation of left ventricle curves and corruption of regional myocardium curves result in systematic errors of regional perfusion up to approximately 24% and overestimates of fractional blood volume (f iv) up to 13%. The correction algorithms lead to significant improvement with errors of perfusion reduced to 7% and errors of f iv within 2% which shows promise for more robust myocardial physiology measurement.

  15. Reactive lymphoid hyperplasia of the liver: Perinodular enhancement on contrast-enhanced computed tomography and magnetic resonance imaging.

    Science.gov (United States)

    Sonomura, Tetsuo; Anami, Shinpei; Takeuchi, Taizo; Nakai, Motoki; Sahara, Shinya; Tanihata, Hirohiko; Sakamoto, Kazuki; Sato, Morio

    2015-06-07

    We report the case of a 69-year-old woman with reactive lymphoid hyperplasia (RLH) of the liver. She underwent partial hepatectomy under a preoperative diagnosis of hepatocellular carcinoma; however, histopathological analysis revealed RLH. The liver nodule showed the imaging feature of perinodular enhancement in the arterial dominant phase on contrast-enhanced computed tomography and magnetic resonance imaging, which could be a useful clue for identifying RLH in the liver. Histologically, the perinodular enhancement was compatible with prominent sinusoidal dilatation surrounding the liver nodule.

  16. Computational fluid dynamics modelling of perfusion measurements in dynamic contrast-enhanced computed tomography: development, validation and clinical applications

    Science.gov (United States)

    Peladeau-Pigeon, M.; Coolens, C.

    2013-09-01

    Dynamic contrast-enhanced computed tomography (DCE-CT) is an imaging tool that aids in evaluating functional characteristics of tissue at different stages of disease management: diagnostic, radiation treatment planning, treatment effectiveness, and monitoring. Clinical validation of DCE-derived perfusion parameters remains an outstanding problem to address prior to perfusion imaging becoming a widespread standard as a non-invasive quantitative measurement tool. One approach to this validation process has been the development of quality assurance phantoms in order to facilitate controlled perfusion ex vivo. However, most of these systems fail to establish and accurately replicate physiologically relevant capillary permeability and exchange performance. The current work presents the first step in the development of a prospective suite of physics-based perfusion simulations based on coupled fluid flow and particle transport phenomena with the goal of enhancing the understanding of clinical contrast agent kinetics. Existing knowledge about a controllable, two-compartmental fluid exchange phantom was used to validate the computational fluid dynamics (CFD) simulation model presented herein. The sensitivity of CFD-derived contrast uptake curves to contrast injection parameters, including injection duration and flow rate, were quantified and found to be within 10% accuracy. The CFD model was employed to evaluate two commonly used clinical kinetic algorithms used to derive perfusion parameters: Fick's principle and the modified Tofts model. Neither kinetic model was able to capture the true transport phenomena it aimed to represent but if the overall contrast concentration after injection remained identical, then successive DCE-CT evaluations could be compared and could indeed reflect differences in regional tissue flow. This study sets the groundwork for future explorations in phantom development and pharmaco-kinetic modelling, as well as the development of novel contrast

  17. Assessment of adult congenital heart disease with multi-detector computed tomography - beyond coronary lumenography

    Energy Technology Data Exchange (ETDEWEB)

    Nicol, E.D. [Department of Radiology, Royal Brompton Hospital, London (United Kingdom) and Department of Cardiology, Royal Brompton Hospital, London (United Kingdom)]. E-mail: e.nicol@rbht.nhs.uk; Gatzoulis, M. [Adult Congenital Heart Centre and Centre for Pulmonary Hypertension, Royal Brompton Hospital and National Heart and Lung Institute, London (United Kingdom); Padley, S.P.G. [Department of Radiology, Royal Brompton Hospital, London (United Kingdom); Rubens, M. [Department of Radiology, Royal Brompton Hospital, London (United Kingdom)

    2007-06-15

    Adult congenital heart disease is an increasingly prevalent condition with more than 135,000 patients affected in England alone. With this increased patient population and an increase in interventional procedures being performed on them, traditional imaging techniques such as cardiac magnetic resonance (CMR) may be unavailable locally or contra-indicated. Cardiac multidetector computed tomography (MDCT) is rapidly emerging as an alternative imaging method for the investigation of these patients and this review highlights the broad application of cardiac MDCT to this population and makes recommendations on the stardardized reporting of complex congenital heart disease.

  18. Interobserver and Intraobserver Reproducibility with Volume Dynamic Contrast Enhanced Computed Tomography (DCE-CT) in Gastroesophageal Junction Cancer

    DEFF Research Database (Denmark)

    Lundsgaard Hansen, Martin; Fallentin, Eva; Axelsen, Thomas;

    2016-01-01

    The purpose of this study was to assess inter- and intra-observer reproducibility of three different analytic methods to evaluate quantitative dynamic contrast-enhanced computed tomography (DCE-CT) measures from gastroesophageal junctional cancer. Twenty-five DCE-CT studies with gastroesophageal ...... were narrower for 3D analysis compared to 2D analysis. Three-dimensional volume DCE-CT analysis of gastroesophageal junction cancer provides higher inter- and intra-observer reproducibility with narrower limits of agreement between readers compared to 2D analysis.......The purpose of this study was to assess inter- and intra-observer reproducibility of three different analytic methods to evaluate quantitative dynamic contrast-enhanced computed tomography (DCE-CT) measures from gastroesophageal junctional cancer. Twenty-five DCE-CT studies with gastroesophageal...... for each observation. Inter- and intra-observer variability were assessed by Intraclass Correlation Coefficient (ICC) and Bland-Altman statistics. Interobserver ICC was excellent for arterial flow (0.88), for blood volume (0.89) and for permeability (0.91) with 3D-VOI analysis. The 95% limits of agreement...

  19. Criteria for establishing shielding of multi-detector computed tomography (MDCT) rooms.

    Science.gov (United States)

    Verdun, F R; Aroua, A; Baechler, S; Schmidt, S; Trueb, P R; Bochud, F O

    2010-01-01

    The aim of this work is to compare two methods used for determining the proper shielding of computed tomography (CT) rooms while considering recent technological advances in CT scanners. The approaches of the German Institute for Standardisation and the US National Council on Radiation Protection and Measurements were compared and a series of radiation measurements were performed in several CT rooms at the Lausanne University Hospital. The following three-step procedure is proposed for assuring sufficient shielding of rooms hosting new CT units with spiral mode acquisition and various X-ray beam collimation widths: (1) calculate the ambient equivalent dose for a representative average weekly dose length product at the position where shielding is required; (2) from the maximum permissible weekly dose at the location of interest, calculate the transmission factor F that must be taken to ensure proper shielding and (3) convert the transmission factor into a thickness of lead shielding. A similar approach could be adopted to use when designing shielding for fluoroscopy rooms, where the basic quantity would be the dose area product instead of the load of current (milliampere-minute).

  20. Role of enhanced multi-detector-row computed tomography before urgent endoscopy in acute upper gastrointestinal bleeding.

    Science.gov (United States)

    Miyaoka, Youichi; Amano, Yuji; Ueno, Sayaka; Izumi, Daisuke; Mikami, Hironobu; Yazaki, Tomotaka; Okimoto, Eiko; Sonoyama, Takayuki; Ito, Satoko; Fujishiro, Hirofumi; Kohge, Naruaki; Imaoka, Tomonori

    2014-04-01

    Multi-detector-row computed tomography (MDCT) has been reported to be a potentially useful modality for detection of the bleeding origin in patients with acute upper massive gastrointestinal (GI) bleeding. The purpose of this study is to investigate the efficacy of MDCT as a routine method for detecting the origin of acute upper GI bleeding prior to urgent endoscopy. Five hundred seventy-seven patients with acute upper GI bleeding (514 nonvariceal patients, 63 variceal patients) who underwent urgent upper GI endoscopy were retrospectively analyzed. Patients were divided into three groups: enhanced MDCT, unenhanced MDCT, and no MDCT before endoscopy. The diagnostic accuracy of MDCT for detection of the bleeding origin was evaluated, and the average procedure times needed to endoscopically identify the bleeding origin were compared between groups. Diagnostic accuracy among endoscopists was 55.3% and 14.7% for the enhanced MDCT and unenhanced MDCT groups, respectively. Among nonvariceal patients, accuracy was 50.2% in the enhanced MDCT group, which was significantly better than that in the unenhanced MDCT group (16.5%). In variceal patients, accuracy was significantly better in the enhanced MDCT group (96.4%) than in the unenhanced MDCT group (0.0%). These accuracies were similar to those achieved by expert radiologists. The average procedure time to endoscopic detection of the bleeding origin in the enhanced MDCT group was significantly faster than that in the unenhanced MDCT and no-MDCT groups. Enhanced MDCT preceding urgent endoscopy may be an effective modality for the detection of bleeding origin in patients with acute upper GI bleeding. © 2013 Journal of Gastroenterology and Hepatology Foundation and Wiley Publishing Asia Pty Ltd.

  1. Predictive value of multi-detector computed tomography for accurate diagnosis of serous cystadenoma: Radiologic-pathologic correlation

    Institute of Scientific and Technical Information of China (English)

    Anjuli A Shah; Nisha I Sainani; Avinash Kambadakone Ramesh; Zarine K Shah; Vikram Deshpande; Peter F Hahn; Dushyant V Sahani

    2009-01-01

    AIM:To identify multi-detector computed tomography (MDCT) features mos t predi c t i ve of serous cystadenomas (SCAs),correlating with histopathology,and to study the impact of cyst size and MDCT technique on reader performance.METHODS:The MDCT scans of 164 patients with surgically verified pancreatic cystic lesions were reviewed by two readers to study the predictive value of various morphological features for establishing a diagnosis of SCAs.Accuracy in lesion characterization and reader confidence were correlated with lesion size (≤3 cm or ≥3 cm) and scanning protocols (dedicated vs routine).RESULTS:28/164 cysts (mean size,39 mm;range,8-92 mm) were diagnosed as SCA on pathology.The MDCT features predictive of diagnosis of SCA were microcystic appearance (22/28,78.6%),surface lobulations (25/28,89.3%) and central scar (9/28,32.4%).Stepwise logistic regression analysis showed that only microcystic appearance was significant for CT diagnosis of SCA (P=0.0001).The sensitivity,specificity and PPV of central scar and of combined microcystic appearance and lobulations were 32.4%/100%/100% and 68%/100%/100%,respectively.The reader confidence was higher for lesions>3 cm (P=0.02) and for MDCT scans performed using thin collimation (1.25-2.5 mm) compared to routine 5 mm collimation exams (P>0.05).CONCLUSION:Central scar on MDCT is diagnostic of SCA but is seen in only one third of SCAs.Microcystic morphology is the most significant CT feature in diagnosis of SCA.A combination of microcystic appearance and surface lobulations offers accuracy comparable to central scar with higher sensitivity.

  2. Imaging features of intraductal papillary mucinous neoplasms of the pancreas in multi-detector row computed tomography

    Institute of Scientific and Technical Information of China (English)

    Ling Tan; Ya-E Zhao; Deng-Bin Wang; Qing-Bing Wang; Jing Hu; Ke-Min Chen; Xia-Xing Deng

    2009-01-01

    AIM:To retrospectively evaluate the imaging features of pancreatic intraductal papillary mucinous neoplasms (IPMNs) in multi-detector row computed tomography (MDCT).METHODS:A total of 20 patients with pathologicallyconfirmed intraductal papillary mucinous neoplasms (IPMNs) were included in this study.Axial MDCT images combined with CT angiography (CTA) and multiplanar volume reformations (MPVR) or curved reformations (CR) were preoperatively acquired.Two radiologists (Tan L and Wang DB) reviewed all the images in consensus using an interactive picture archiving and communication system.The disputes in readings were resolved through consultation with a third experienced radiologist (Chen KM).Finally,the findings and diagnoses were compared with the pathologic results.RESULTS:The pathological study revealed 12 malignant IPMNs and eight benign IPMNs.The diameters of the cystic lesions and main pancreatic ducts (MPDs) were significantly larger in malignant IPMNs compared with those of the benign IPMNs (P<0.05).The combinedtype IPMNs had a higher rate of malignancy than the other two types of IPMNs (P<0.05).Tumors with mural nodules and thick septa had a significantly higher incidence of malignancy than tumors without these features (P<0.05).Communication of side-branch IPMNs with the MPD was present in nine cases at pathologic examination.Seven of them were identified from CTA and MPVR or CR images.From comparison with the pathological diagnosis,the sensitivity,specificity,and accuracy of MDCT in characterizing the malignancy of IPMN of the pancreas were determined to be 100%,87.5% and 95%,respectively.CONCLUSION:MDCT with CTA and MPVR or CR techniques can elucidate the imaging features of IPMNs and help predict the malignancy of these tumors.

  3. Denver screening protocol for blunt cerebrovascular injury reduces the use of multi-detector computed tomography angiography.

    Science.gov (United States)

    Beliaev, Andrei M; Barber, P Alan; Marshall, Roger J; Civil, Ian

    2014-06-01

    Blunt cerebrovascular injury (BCVI) occurs in 0.2-2.7% of blunt trauma patients and has up to 30% mortality. Conventional screening does not recognize up to 20% of BCVI patients. To improve diagnosis of BCVI, both an expanded battery of screening criteria and a multi-detector computed tomography angiography (CTA) have been suggested. The aim of this study is to investigate whether the use of CTA restricted to the Denver protocol screen-positive patients would reduce the unnecessary use of CTA as a pre-emptive screening tool. This is a registry-based study of blunt trauma patients admitted to Auckland City Hospital from 1998 to 2012. The diagnosis of BCVI was confirmed or excluded with CTA, magnetic resonance angiography and, if these imaging were non-conclusive, four-vessel digital subtraction angiography. Thirty (61%) BCVI and 19 (39%) non-BCVI patients met eligibility criteria. The Denver protocol applied to our cohort of patients had a sensitivity of 97% (95% confidence interval (CI): 83-100%) and a specificity of 42% (95% CI: 20-67%). With a prevalence of BCVI in blunt trauma patients of 0.2% and 2.7%, post-test odds of a screen-positive test were 0.03 (95% CI: 0.002-0.005) and 0.046 (95% CI: 0.314-0.068), respectively. Application of the CTA to the Denver protocol screen-positive trauma patients can decrease the use of CTA as a pre-emptive screening tool by 95-97% and reduces its hazards. © 2013 Royal Australasian College of Surgeons.

  4. Surveillance policy for Japanese patients with stage I testicular germ cell cancer in the multi-detector computed tomography era.

    Science.gov (United States)

    Yuasa, Takeshi; Inoshita, Naoko; Tanaka, Hajime; Urakami, Shinji; Yamamoto, Shinya; Fujii, Yasuhisa; Masuda, Hitoshi; Fukui, Iwao; Ishikawa, Yuichi; Yonese, Junji

    2015-12-01

    The outcome of surveillance for Japanese patients with clinical stage I testicular germ cell cancer (GCC) was investigated in the multi-detector computed tomography (MDCT) era. The medical records of 92 Japanese patients with stage I GCC, who received treatment in our institution between March 1999 and February 2013, were reviewed. As six patients requested and received prophylactic chemotherapy and two patients seriously deviated from surveillance schedule, these patients were excluded from the study. Data from a total 84 patients were analyzed, The median follow-up period following diagnosis was 5.1 years (inter-quartile range: IQR, 2.3-7.7 years). Of the 84 patients, eight (9.5 %) had a recurrence of their cancer in this observation period. Regarding histologic subtypes, the recurrence rates were five (9.3 %) of the 54 patients with seminoma and three (10 %) of the 30 patients with nonseminomatous germ cell tumor (NSGCT). All eight patients who experienced a recurrence did so within 2 years; they all underwent induction chemotherapy and remain alive at the time of writing, with no evidence of disease. Among 31 seminoma patients with a tumor more than 4 cm in size and rete testis invasion, cancer recurred in three (9.7 %) during the surveillance period. On the other hand, among the 13 patients with NSGCT and vascular invasion, three (23 %) experienced a recurrence, whereas the figure was zero for the 11 (0 %) patients without vascular invasion. Fewer than 10 % of Japanese patients with stage I testicular GCC suffered a recurrence in the 5-year observation period of this study. The risk of occult disease, which will result in relapse, might be decreased in the MDCT era. All patients must be fully informed of the anticipated recurrence rate and the potential risks of exposure to chemotherapy agents.

  5. Diagnostic performance of using effervescent powder for detection and grading of esophageal varices by multi-detector computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Cansu, Aysegul, E-mail: drcansu@gmail.com [Department of Radiology, Karadeniz Technical University School of Medicine, Farabi Hospital, 61080 Trabzon (Turkey); Ahmetoglu, Ali; Kul, Sibel; Yukunc, Gokcen [Department of Radiology, Karadeniz Technical University School of Medicine, Farabi Hospital, 61080 Trabzon (Turkey); Fidan, Sami; Arslan, Mehmet [Department of Gastroenterology, Karadeniz Technical University School of Medicine, Farabi Hospital, 61080 Trabzon (Turkey); Topbas, Murat [Department of Public Health, Karadeniz Technical University School of Medicine, Farabi Hospital, 61080 Trabzon (Turkey)

    2014-03-15

    Purpose: To investigate the effect of using effervescent powder (EP) on the efficacy of multi-detector computed tomography (MDCT) in detection and grading of esophageal varices in cirrhotic patients by considering endoscopy as the gold standard. Materials and methods: Ninety-two cirrhotic patients undergoing biphasic liver MDCT followed by upper gastrointestinal endoscopy within 4 weeks of MDCT were prospectively evaluated. The patients were divided into two groups before MDCT. The first group (n = 50) received effervescent powder (EP) before and during MDCT procedure and the second group did not receive (n = 42). The presence, size and grade of the esophageal varices were evaluated. MDCT findings were compared with endoscopic results. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and accuracy of MDCT with EP and without EP were calculated and compared. Correlations between the grades of the varices for each group based on MDCT imaging and endoscopic grading were also evaluated. Results: The sensitivity, specificity, accuracy, PPV, and NPV of MDCT were 100%, 88%, 96%, 94%, and 100%, respectively, in the EP group, whereas they were 76%, 67%, 74%, 89%, and 43%, respectively, in the non-EP group. Correlations between the grades of the esophageal varices on MDCT and endoscopy were significant in both groups (r = 0.94, p < 0.001 for EP group and r = 0.70, p < 0.001 for non-EP group). Conclusion: During periodic CT scanning of cirrhotic patients, use of EP increases the success rate of MDCT for detection and grading of esophageal varices.

  6. Differential diagnosis of solitary pulmonary inflammatory lesions and peripheral lung cancers with contrast-enhanced computed tomograph

    Energy Technology Data Exchange (ETDEWEB)

    Chu, Zhi-gang; Sheng, Bo; Liu, Meng-qi; Lv, Fa-jin; Li, Qi; Ouyang, Yu, E-mail: cyscitg@163.com [Hospital of Chongqing Medical University, Department of Radiology, Chongqing (China)

    2016-10-15

    Objectives: To clarify differences between solitary pulmonary inflammatory lesions and peripheral lung cancers with contrast-enhanced computed tomography. Methods: In total, 64 and 132 patients with solitary pulmonary inflammatory masses/nodules and peripheral lung cancers, respectively, were enrolled in this study. Their computed tomographic findings were summarized and compared retrospectively. Results: Compared with the peripheral lung cancers, the inflammatory lesions were located closer to the pleura (p<0.0001). The majority of the inflammatory lesions were patchy and oval-shaped (82.8%), whereas most of the tumors were lobulated (82.6%). Almost all the inflammatory cases were unclear (93.8%), whereas most of the tumors had speculated margins (72.7%). Computed tomography values were significantly higher for the inflammatory lesions than for the cancers (p<0.0001). More than half of the inflammatory lesions had defined necrosis (59.3%). Furthermore, 49.2% of the cancers enhanced inhomogeneously, but only 24.6% had ill-defined necrosis or cavities. The peripheral zones of 98.4% of the inflammatory lesions and 72.7% of the tumors were unclear, with peripheral scattered patches (92.2%) and beam-shaped opacity (66.7%) being the most common findings, respectively. Adjacent pleural thickening was more frequent for the inflammatory lesions than the cancers (95.3% vs. 21.1%, p<0.0001), whereas pleural indentation was found in 67.4% of the subjects with cancer. In addition, hilar (p=0.034) and mediastinal (p=0.003) lymphadenopathy were more commonly detected in the cancers than in the inflammatory cases. Conclusions: Contrast-enhanced computed tomography findings for pulmonary inflammatory lesions and peripheral lung cancers were significantly different in many aspects. Developing a comprehensive understanding of these differences is helpful for directing their management. (author)

  7. Hypertensive crisis due to contrast-enhanced computed tomography in a patient with malignant pheochromocytoma.

    Science.gov (United States)

    Nakano, Sachiko; Tsushima, Yoshito; Taketomi-Takahashi, Ayako; Higuchi, Tetsuya; Amanuma, Makoto; Oriuchi, Noboru; Endo, Keigo

    2011-07-01

    A 63-year-old man underwent computed tomography (CT) using intravenous low-osmolar iodine contrast medium (LOCM) 6 days after undergoing high-dose (131)I-MIBG therapy for metastatic pheochromocytoma. Immediately after the CT examination, his blood pressure increased to 260/160 mmHg (from 179/101 mmHg before the examination). Phentolamine mesilate was administered, and the blood pressure rapidly went back to normal. Although hypertensive crisis after administration of LOCM is rare, this case suggests that high-dose (131)IMIBG therapy may be a risk factor for hypertensive crisis after administration of intravenous LOCM.

  8. Contrast-enhanced fluorodeoxyglucose positron emission tomography/computed tomography in solid pseudopapillary neoplasm of the pancreas.

    Science.gov (United States)

    Santhosh, Sampath; Lakshmanan, Ramesh Kumar; Sonik, Bhavay; Padmavathy, Rajagopalan; Gunaseelan, Rajamani Emmanuel

    2016-01-01

    Solid pseudopapillary neoplasm (SPN) of the pancreas is a rare pancreatic tumor with low malignant potential. It occurs characteristically more often in young women. Radiological and pathological studies have revealed that the tumor is quite different from other pancreatic tumors. Limited information is available in the literature reporting their accumulation of fluorine-(18) fluorodeoxyglucose ((18)F-FDG) in positron emission tomography/computed tomography (PET/CT). Here, we report a case of pancreatic SPN imaged with contrast-enhanced FDG PET/CT. A percutaneous fine needle aspiration from the metabolically active lesion revealed SPN, and it was confirmed with histopathological results. Recurrence or metastasis was not found after 7 months of follow-up.

  9. Can contrast-enhanced ultrasonography replace multidetector-computed tomography in the detection of liver metastases from colorectal cancer?

    DEFF Research Database (Denmark)

    Larsen, Lars P.S.; Rosenkilde, Mona; Christensen, Henrik;

    2007-01-01

    consecutive patients referred to the Department of Colorectal Surgery, Aarhus University Hospital with primary or local recurrence of CRC. The patients underwent liver ultrasonography (US), CEUS, MDCT and intraoperative ultrasonography (IOUS). Fine-needle biopsy was performed on all suspicious lesions......PURPOSE: To compare the sensitivity and specificity of contrast-enhanced ultrasonography (CEUS) and 4-slice multidetector-computed tomography (MDCT) in the detection of liver metastases in patients with colorectal cancer (CRC). MATERIALS AND METHODS: Candidates for this prospective study were 461....... The examinations were interpreted blindly and the combination of US, CEUS, biphasic MDCT, IOUS, follow up and biopsy was the gold standard. RESULTS: Three hundred and sixty-five patients were included. All patients had undergone preoperative US, CEUS and MDCT and 65.5% had received IOUS. The gold standard found...

  10. Contrast-enhanced postmortem computed tomography in clinical pathology: enhanced value of 20 clinical autopsies.

    Science.gov (United States)

    Westphal, Saskia E; Apitzsch, Jonas C; Penzkofer, Tobias; Kuhl, Christiane K; Mahnken, Andreas H; Knüchel, Ruth

    2014-09-01

    Postmortem computed tomography (PMCT) is a modern tool that complements autopsy diagnostics. In clinical autopsies, a major cause of death is cardiovascular disease. To improve the performance of PMCT in cardiovascular disease, full body angiography was developed (PMCT angiography [PMCTA]). Twenty PMCTA scans generated before autopsy were compared with native PMCT and clinical autopsy. The objective of the study was to quantify the additional diagnostic value of adding angiography to native imaging and to compare PMCT and PMCTA findings to autopsy findings. The diagnosis of the cause of death was identical or overlapped in 80% of the cases that used PMCTA and 70% that used PMCT. The additional diagnostic yield given by PMCT and PMCTA in combination with autopsy was 55%. PMCT yielded additional diagnoses in the musculoskeletal system. The greatest additional diagnostic value of PMCTA was in association with cardiovascular diagnoses. The accuracy of PMCTA for cardiac causes of death was 80%, and the positive predictive value was 90%. The findings indicate that native PMCT cannot display the cardiovascular system sufficiently clearly for high-quality diagnostic assessment. However, PMCTA is a powerful tool in autopsy cases with a history of cardiovascular disease and/or a suspected cardiovascular cause of death. The combination of PMCTA and clinical autopsy enhances diagnostic quality and completeness of the autopsy report. Furthermore, in cases without consent or with a restricted consent for clinical autopsy, PMCTA has the potential to provide information on cardiovascular causes of death.

  11. Comparison of aortic annulus diameter measurement between multi-detector computed tomography and echocardiography: a meta-analysis.

    Directory of Open Access Journals (Sweden)

    Ruifang Zhang

    Full Text Available BACKGROUND AND PURPOSE: Accurate measurement of aortic annulus diameter is crucial for choosing suitable prosthetic size for transcatheter aortic valve implantation (TAVI. Several imaging methods are available for the measurement, but significant variability between different modalities has been observed. The purpose of this study was to systematically compare the measurements of aortic annulus diameter between multi-detector computed tomography (MDCT, transthoracic echocardiography (TTE, and transesophegeal echocardiography (TEE. METHODS: PubMed and EMBASE databases between January 2000 and January 2012 were searched. We extracted data from eligible studies evaluating the aortic annulus diameter by MDCT and echocardiography (TTE, TEE, or both. We performed a random-effects meta-analysis to calculate the weighted mean differences of aortic annulus diameter measurement between MDCT, TTE, and TEE. RESULTS: A total of 10 eligible studies involving 581 subjects with aortic valve stenosis were included. Aortic annulus diameter measured on coronal view by MDCT (25.3±0.52 mm was respectively larger than that measured on sagittal view by MDCT (22.7±0.37 mm, TTE (22.6±0.28 mm, and TEE (23.1±0.32 mm. The weighted mean difference of aortic annulus diameter between coronal view by MDCT and TTE these two methods was 2.97 mm, followed by the weighted mean difference of 2.53 mm between coronal view and sagittal view by MDCT, and the mean difference of 1.74 mm between coronal view on MDCT and TEE (P<0.0001 for all. The weighted mean difference of aortic annulus diameter measurement between TEE and TTE was significant but somewhat small (0.45 mm, P = 0.007. CONCLUSION: Aortic annulus diameter measured on coronal view by MDCT was robustly and significantly larger than that obtained on sagittal view by MDCT, TTE, or TEE. Such variability of aortic annulus diameter measurement by different imaging modalities cannot be ignored when developing optimal

  12. Diagnostic accuracy of magnetic resonance, computed tomography and contrast enhanced ultrasound in radiological multimodality assessment of peribiliary liver metastases.

    Science.gov (United States)

    Granata, Vincenza; Fusco, Roberta; Catalano, Orlando; Avallone, Antonio; Palaia, Raffaele; Botti, Gerardo; Tatangelo, Fabiana; Granata, Francesco; Cascella, Marco; Izzo, Francesco; Petrillo, Antonella

    2017-01-01

    We compared diagnostic performance of Magnetic Resonance (MR), Computed Tomography (CT) and Ultrasound (US) with (CEUS) and without contrast medium to identify peribiliary metastasis. We identified 35 subjects with histological proven peribiliary metastases who underwent CEUS, CT and MR study. Four radiologists evaluated the presence of peribiliary lesions, using a 4-point confidence scale. Echogenicity, density and T1-Weigthed (T1-W), T2-W and Diffusion Weighted Imaging (DWI) signal intensity as well as the enhancement pattern during contrast studies on CEUS, CT and MR so as hepatobiliary-phase on MRI was assessed. All lesions were detected by MR. CT detected 8 lesions, while US/CEUS detected one lesion. According to the site of the lesion, respect to the bile duct and hepatic parenchyma: 19 (54.3%) were periductal, 15 (42.8%) were intra-periductal and 1 (2.8%) was periductal-intrahepatic. According to the confidence scale MRI had the best diagnostic performance to assess the lesion. CT obtained lower diagnostic performance. There was no significant difference in MR signal intensity and contrast enhancement among all metastases (p>0.05). There was no significant difference in CT density and contrast enhancement among all metastases (p>0.05). MRI is the method of choice for biliary tract tumors but it does not allow a correct differential diagnosis among different histological types of metastasis. The presence of biliary tree dilatation without hepatic lesions on CT and US/CEUS study may be an indirect sign of peribiliary metastases and for this reason the patient should be evaluated by MRI.

  13. Dual-energy computed tomography for the assessment of early treatment effects of regorafenib in a preclinical tumor model: comparison with dynamic contrast-enhanced CT and conventional contrast-enhanced single-energy CT

    Energy Technology Data Exchange (ETDEWEB)

    Knobloch, Gesine; Hamm, Bernd [Charite - Universitaetsmedizin Berlin, Department of Radiology, Berlin (Germany); Jost, Gregor; Pietsch, Hubertus [Bayer Healthcare, MR and CT Contrast Media Research, Berlin (Germany); Huppertz, Alexander [Imaging Science Institute Charite - Siemens, Berlin (Germany)

    2014-08-15

    The potential diagnostic value of dual-energy computed tomography (DE-CT) compared to dynamic contrast-enhanced CT (DCE-CT) and conventional contrast-enhanced CT (CE-CT) in the assessment of early regorafenib treatment effects was evaluated in a preclinical setting. A rat GS9L glioma model was examined with contrast-enhanced dynamic DE-CT measurements (80 kV/140 kV) for 4 min before and on days 1 and 4 after the start of daily regorafenib or placebo treatment. Tumour time-density curves (0-240 s, 80 kV), DE-CT (60 s) derived iodine maps and the DCE-CT (0-30 s, 80 kV) based parameters blood flow (BF), blood volume (BV) and permeability (PMB) were calculated and compared to conventional CE-CT (60 s, 80 kV). The regorafenib group showed a marked decrease in the tumour time-density curve, a significantly lower iodine concentration and a significantly lower PMB on day 1 and 4 compared to baseline, which was not observed for the placebo group. CE-CT showed a significant decrease in tumour density on day 4 but not on day 1. The DE-CT-derived iodine concentrations correlated with PMB and BV but not with BF. DE-CT allows early treatment monitoring, which correlates with DCE-CT. Superior performance was observed compared to single-energy CE-CT. circle Regorafenib treatment response was evaluated by CT in a rat tumour model. (orig.)

  14. Diagnosis of hepatic steatosis by contrast-enhanced abdominal computed tomography; Diagnostico da esteatose hepatica pela tomografia computadorizada de abdome com meio de contraste intravenoso

    Energy Technology Data Exchange (ETDEWEB)

    Monjardim, Rodrigo da Fonseca; Costa, Danilo Manuel Cerqueira; Romano, Ricardo Francisco Tavares; Salvadori, Priscila Silveira; Santos, Jaime de Vargas Conde dos; Atzingen, Augusto Castelli Von; Shigueoka, David Carlos; D' Ippolito, Giuseppe, E-mail: giuseppe_dr@uol.com.br [Universidade Federal de Sao Paulo (EPM/UNIFESP), SP (Brazil). Escola Paulista de Medicina. Dept. de Diagnostico por Imagem

    2013-05-15

    Objective: to evaluate the diagnostic capacity of abdominal computed tomography in the assessment of hepatic steatosis using the portal phase with a simplified calculation method as compared with the non-contrast-enhanced phase. Materials and methods: in the present study, 150 patients were retrospectively evaluated by means of non-contrast-enhanced and contrast-enhanced computed tomography. One hundred patients had hepatic steatosis and 50 were control subjects. For the diagnosis of hepatic steatosis in the portal phase, the authors considered a result of < 104 HU calculated by the formula [L - 0.3 Multiplication-Sign (0.75 Multiplication-Sign P + 0.25 Multiplication-Sign A)] / 0.7, where L, P and A represent the attenuation of the liver, of the main portal vein and abdominal aorta, respectively. Sensitivity, specificity, positive and negative predictive values were calculated, using non-contrast-enhanced computed tomography as the reference standard. Results: the simplified calculation method with portal phase for the diagnosis of hepatic steatosis showed 100% sensitivity, 36% specificity, negative predictive value of 100% and positive predictive value of 75.8%. The rate of false positive results was 64%. False negative results were not observed. Conclusion: The portal phase presents an excellent sensitivity in the diagnosis of hepatic steatosis, as compared with the non-contrast-enhanced phase of abdominal computed tomography. However, the method has low specificity. (author)

  15. The benefit of non contrast-enhanced magnetic resonance angiography for predicting vascular access surgery outcome: a computer model perspective.

    Directory of Open Access Journals (Sweden)

    Maarten A G Merkx

    Full Text Available INTRODUCTION: Vascular access (VA surgery, a prerequisite for hemodialysis treatment of end-stage renal-disease (ESRD patients, is hampered by complication rates, which are frequently related to flow enhancement. To assist in VA surgery planning, a patient-specific computer model for postoperative flow enhancement was developed. The purpose of this study is to assess the benefit of non contrast-enhanced magnetic resonance angiography (NCE-MRA data as patient-specific geometrical input for the model-based prediction of surgery outcome. METHODS: 25 ESRD patients were included in this study. All patients received a NCE-MRA examination of the upper extremity blood vessels in addition to routine ultrasound (US. Local arterial radii were assessed from NCE-MRA and converted to model input using a linear fit per artery. Venous radii were determined with US. The effect of radius measurement uncertainty on model predictions was accounted for by performing Monte-Carlo simulations. The resulting flow prediction interval of the computer model was compared with the postoperative flow obtained from US. Patients with no overlap between model-based prediction and postoperative measurement were further analyzed to determine whether an increase in geometrical detail improved computer model prediction. RESULTS: Overlap between postoperative flows and model-based predictions was obtained for 71% of patients. Detailed inspection of non-overlapping cases revealed that the geometrical details that could be assessed from NCE-MRA explained most of the differences, and moreover, upon addition of these details in the computer model the flow predictions improved. CONCLUSIONS: The results demonstrate clearly that NCE-MRA does provide valuable geometrical information for VA surgery planning. Therefore, it is recommended to use this modality, at least for patients at risk for local or global narrowing of the blood vessels as well as for patients for whom an US-based model

  16. Endovascular treatment of thoracic aortic diseases: Follow-up and complications with multi-detector computed tomography angiography

    Energy Technology Data Exchange (ETDEWEB)

    Iezzi, Roberto [Department of Radiology, University ' G. D' Annunzio' , Chieti (Italy)], E-mail: r.iezzi@rad.unich.it; Cotroneo, Antonio Raffaele; Marano, Riccardo; Filippone, Antonella; Storto, Maria Luigia [Department of Radiology, University ' G. D' Annunzio' , Chieti (Italy)

    2008-03-15

    Endovascular procedures with placement of stent-graft has become an accepted alternative to traditional open surgery for treatment of descending thoracic aortic aneurysms, ulcers, post-traumatic rupture, or complications of type-B dissection, due to significant reduction in perioperative mortality, rate of complications and length of hospitalization. Moreover, increasing operator experience and continuous advances in stent-graft technology are making treatment of a wider range of cases possible with redefinition of guidelines for endovascular stent-graft. The feasibility of endovascular stent-graft is mainly dependent on anatomic factors which represent the important predictors of the success of this procedure as well as on strictly follow-up in order to obtain early detection and treatment of eventual complications. Multi-detector CT-angiography is a fast, safe, and minimally invasive imaging technique that represents the standard of reference in the follow-up of patients who have undergone endovascular stent-graft, as it is effective and specific in the detection of procedure-correlated complications. The purpose of this article is to give a brief review of those techniques most commonly used for endovascular treatment of thoracic aortic diseases together with a more detailed description of post-procedural complications and their appearance on multi-detector CT-angiography.

  17. Non-invasive determination of pulmonary hypertension with dynamic contrast-enhanced computed tomography: a pilot study

    Energy Technology Data Exchange (ETDEWEB)

    Pienn, Michael; Balint, Zoltan [Ludwig Boltzmann Institute for Lung Vascular Research, Graz (Austria); Kovacs, Gabor; Tscherner, Maria; Olschewski, Horst [Ludwig Boltzmann Institute for Lung Vascular Research, Graz (Austria); Medical University of Graz, Division of Pulmonology, Department of Internal Medicine, Graz (Austria); Avian, Alexander [Ludwig Boltzmann Institute for Lung Vascular Research, Graz (Austria); Medical University of Graz, Institute for Medical Informatics, Statistics and Documentation, Graz (Austria); Johnson, Thorsten R. [Ludwig Maximilians University, Department of Clinical Radiology, Munich (Germany); Kullnig, Peter [DiagnostikZentrum Graz, Graz (Austria); Stollberger, Rudolf [Graz University of Technology, Institute for Medical Engineering, Graz (Austria); Olschewski, Andrea [Ludwig Boltzmann Institute for Lung Vascular Research, Graz (Austria); Medical University of Graz, Experimental Anesthesiology, Department of Anesthesia and Intensive Care Medicine, Graz (Austria)

    2014-03-15

    In this pilot study we explored whether contrast-material bolus propagation time and speed in the pulmonary arteries (PAs) determined by dynamic contrast-enhanced computed tomography (DCE-CT) can distinguish between patients with and without pulmonary hypertension (PH). Twenty-three patients (18 with and 5 without PH) were examined with a DCE-CT sequence following their diagnostic or follow-up right-sided heart catheterisation (RHC). X-ray attenuation over time curves were recorded for regions of interest in the main, right and left PA and fitted with a spline fit. Contrast material bolus propagation speeds and time differences between the peak concentrations were compared with haemodynamic parameters from RHC. Bolus speed correlated (ρ = -0.55) with mean pulmonary arterial pressure (mPAP) and showed a good discriminative power between patients with and without PH (cut-off speed 317 mm/s; sensitivity 100 %/specificity 100 %). Additionally, time differences between peaks correlated with mPAP (ρ = 0.64 and 0.49 for right and left PA, respectively) and discrimination was achieved with sensitivity 100 %/specificity 100 % (cut-off time 0.15 s) and sensitivity 93 %/specificity 80 % (cut-off time 0.45 s), respectively. Bolus propagation speed and time differences between contrast material peaks in the PA can identify PH. This method could be used to confirm the indication for RHC in patients screened for pulmonary hypertension. (orig.)

  18. Interobserver and Intraobserver Reproducibility with Volume Dynamic Contrast Enhanced Computed Tomography (DCE-CT in Gastroesophageal Junction Cancer

    Directory of Open Access Journals (Sweden)

    Martin Lundsgaard Hansen

    2016-02-01

    Full Text Available The purpose of this study was to assess inter- and intra-observer reproducibility of three different analytic methods to evaluate quantitative dynamic contrast-enhanced computed tomography (DCE-CT measures from gastroesophageal junctional cancer. Twenty-five DCE-CT studies with gastroesophageal junction cancer were selected from a previous longitudinal study. Three radiologists independently reviewed all scans, and one repeated the analysis eight months later for intraobserver analysis. Review of the scans consisted of three analysis methods: (I Four, fixed small sized regions of interest (2-dimensional (2D fixed ROIs placed in the tumor periphery, (II 2-dimensional regions of interest (2D-ROI along the tumor border in the tumor center, and (III 3-dimensional volumes of interest (3D-VOI containing the entire tumor volume. Arterial flow, blood volume and permeability (ktrans were recorded for each observation. Inter- and intra-observer variability were assessed by Intraclass Correlation Coefficient (ICC and Bland-Altman statistics. Interobserver ICC was excellent for arterial flow (0.88, for blood volume (0.89 and for permeability (0.91 with 3D-VOI analysis. The 95% limits of agreement were narrower for 3D analysis compared to 2D analysis. Three-dimensional volume DCE-CT analysis of gastroesophageal junction cancer provides higher inter- and intra-observer reproducibility with narrower limits of agreement between readers compared to 2D analysis.

  19. Analysis of factors influencing the integrated bolus peak timing in contrast-enhanced brain computed tomographic angiography

    Energy Technology Data Exchange (ETDEWEB)

    Son, Soon Yong [Wonkwang Health Science University, Iksan (Korea, Republic of); Choi, Kwan Woo [Asan Medical Center, Seoul (Korea, Republic of); Jeong, Hoi Woun [Baekseok Culture University College, Cheonan (Korea, Republic of); Jang, Seo Goo [Soonchunhyang University, Asan (Korea, Republic of); Jung, Jae Young [Sanggye Paik Hospital, Seoul (Korea, Republic of); Yun, Jung Soo [Samsung Medical Center, Seoul (Korea, Republic of); Kim, Ki Won [Kyung Hee University Hospital at Gang-dong, Seoul (Korea, Republic of); Lee, Young Ah; Son, Jin Hyun; Min, Jung Whan [Shingu University College, Sungnam (Korea, Republic of)

    2016-03-15

    The objective of this study was to analyze the factors influencing integrated bolus peak timing in contrast- enhanced computed tomographic angiography (CTA) and to determine a method of calculating personal peak time. The optimal time was calculated by performing multiple linear regression analysis, after finding the influence factors through correlation analysis between integrated peak time of contrast medium and personal measured value by monitoring CTA scans. The radiation exposure dose in CTA was 716.53 mGy·cm and the radiation exposure dose in monitoring scan was 15.52 mGy (2 - 34 mGy). The results were statistically significant (p < .01). Regression analysis revealed, a -0.160 times decrease with a one-step increase in heart rate in male, and -0.004, -0.174, and 0.006 times decrease with one-step in DBP, heart rate, and blood sugar, respectively, in female. In a consistency test of peak time by calculating measured peak time and peak time by using the regression equation, the consistency was determined to be very high for male and female. This study could prevent unnecessary dose exposure by encouraging in clinic calculation of personal integrated peak time of contrast medium prior to examination.

  20. Current status and guidelines for the assessment of tumour vascular support with dynamic contrast-enhanced computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Miles, K.A. [University of Sussex, Clinical Imaging Sciences Centre, Brighton and Sussex Medical School, Falmer (United Kingdom); Lee, T.Y. [Robarts Research Institute, Imaging Research Laboratories, London, Ontario (Canada); Goh, V. [St Thomas' Hospital, Division of Imaging Sciences and Biomedical Engineering, King' s College London, London (United Kingdom); Klotz, E. [Computed Tomography H IM CT PLM-E PA, Siemens Healthcare Sector, Forchheim (Germany); Cuenod, C. [INSERM U970 PARCC, Hopital Europeen Georges Pompidou (HEGP), Paris (France); Bisdas, S. [Eberhard Karls University, Department of Neuroradiology, Tuebingen (Germany); Groves, A.M. [University College London, University College Hospital, Institute of Nuclear Medicine, London (United Kingdom); Hayball, M.P. [Cambridge Computed Imaging Ltd, Cambridge (United Kingdom); Alonzi, R. [Mount Vernon Cancer Centre, Northwood (United Kingdom); Brunner, T. [Gray Institute for Radiation, Oncology and Biology, Oxford (United Kingdom)

    2012-07-15

    Dynamic contrast-enhanced computed tomography (DCE-CT) assesses the vascular support of tumours through analysis of temporal changes in attenuation in blood vessels and tissues during a rapid series of images acquired with intravenous administration of iodinated contrast material. Commercial software for DCE-CT analysis allows pixel-by-pixel calculation of a range of validated physiological parameters and depiction as parametric maps. Clinical studies support the use of DCE-CT parameters as surrogates for physiological and molecular processes underlying tumour angiogenesis. DCE-CT has been used to provide biomarkers of drug action in early phase trials for the treatment of a range of cancers. DCE-CT can be appended to current imaging assessments of tumour response with the benefits of wide availability and low cost. This paper sets out guidelines for the use of DCE-CT in assessing tumour vascular support that were developed using a Delphi process. Recommendations encompass CT system requirements and quality assurance, radiation dosimetry, patient preparation, administration of contrast material, CT acquisition parameters, terminology and units, data processing and reporting. DCE-CT has reached technical maturity for use in therapeutic trials in oncology. The development of these consensus guidelines may promote broader application of DCE-CT for the evaluation of tumour vascularity. (orig.)

  1. Interobserver and Intraobserver Reproducibility with Volume Dynamic Contrast Enhanced Computed Tomography (DCE-CT) in Gastroesophageal Junction Cancer.

    Science.gov (United States)

    Lundsgaard Hansen, Martin; Fallentin, Eva; Axelsen, Thomas; Lauridsen, Carsten; Norling, Rikke; Svendsen, Lars Bo; Nielsen, Michael Bachmann

    2016-02-01

    The purpose of this study was to assess inter- and intra-observer reproducibility of three different analytic methods to evaluate quantitative dynamic contrast-enhanced computed tomography (DCE-CT) measures from gastroesophageal junctional cancer. Twenty-five DCE-CT studies with gastroesophageal junction cancer were selected from a previous longitudinal study. Three radiologists independently reviewed all scans, and one repeated the analysis eight months later for intraobserver analysis. Review of the scans consisted of three analysis methods: (I) Four, fixed small sized regions of interest (2-dimensional (2D) fixed ROIs) placed in the tumor periphery, (II) 2-dimensional regions of interest (2D-ROI) along the tumor border in the tumor center, and (III) 3-dimensional volumes of interest (3D-VOI) containing the entire tumor volume. Arterial flow, blood volume and permeability (k(trans)) were recorded for each observation. Inter- and intra-observer variability were assessed by Intraclass Correlation Coefficient (ICC) and Bland-Altman statistics. Interobserver ICC was excellent for arterial flow (0.88), for blood volume (0.89) and for permeability (0.91) with 3D-VOI analysis. The 95% limits of agreement were narrower for 3D analysis compared to 2D analysis. Three-dimensional volume DCE-CT analysis of gastroesophageal junction cancer provides higher inter- and intra-observer reproducibility with narrower limits of agreement between readers compared to 2D analysis.

  2. Differentiation of pyogenic hepatic abscesses from malignant mimickers using multislice-based texture acquired from contrast-enhanced computed tomography

    Institute of Scientific and Technical Information of China (English)

    Shi-Teng Suo; Zhi-Guo Zhuang; Meng-Qiu Cao; Li-Jun Qian; Xin Wang; Run-Lin Gao; Yu Fan; Jian-Rong Xu

    2016-01-01

    BACKGROUND: Pyogenic hepatic abscess may mimic prima-ry or secondary carcinoma of the liver on contrast-enhanced computed tomography (CECT). The present study was to ex-plore the usefulness of the analysis of multislice-based texture acquired from CECT in the differentiation between pyogenic hepatic abscesses and malignant mimickers. METHODS: This retrospective study included 25 abscesses in 20 patients and 33 tumors in 26 subjects who underwent CECT. To make comparison, we also enrolled 19 patients with hepatic single simple cyst. The images from CECT were ana-lyzed using a Laplacian of Gaussian band-pass iflter (5 iflter levels with sigma weighting ranging from 1.0 to 2.5). We also quantiifed the uniformity, entropy, kurtosis and skewness of the multislice-based texture at different sigma weightings. Sta-tistical signiifcance for these parameters was tested with one-way ANOVA followed by Tukey honestly signiifcant difference (HSD) test. Diagnostic performance was evaluated using the receiver operating characteristic (ROC) curve analysis. RESULTS: There were signiifcant differences in entropy and uniformity at all sigma weightings (P CONCLUSION: Multislice-based texture analysis may be use-ful for differentiating pyogenic hepatic abscesses from malig-nant mimickers.

  3. A novel in vivo vascular imaging approach for hierarchical quantification of vasculature using contrast enhanced micro-computed tomography.

    Directory of Open Access Journals (Sweden)

    Laura Nebuloni

    Full Text Available The vasculature of body tissues is continuously subject to remodeling processes originating at the micro-vascular level. The formation of new blood vessels (angiogenesis is essential for a number of physiological and pathophysiological processes such as tissue regeneration, tumor development and the integration of artificial tissues. There are currently no time-lapsed in vivo imaging techniques providing information on the vascular network at the capillary level in a non-destructive, three-dimensional and high-resolution fashion. This paper presents a novel imaging framework based on contrast enhanced micro-computed tomography (micro-CT for hierarchical in vivo quantification of blood vessels in mice, ranging from largest to smallest structures. The framework combines for the first time a standard morphometric approach with densitometric analysis. Validation tests showed that the method is precise and robust. Furthermore, the framework is sensitive in detecting different perfusion levels after the implementation of a murine ischemia-reperfusion model. Correlation with both histological data and micro-CT analysis of vascular corrosion casts confirmed accuracy of the method. The newly developed time-lapsed imaging approach shows high potential for in vivo monitoring of a number of different physiological and pathological conditions in angiogenesis and vascular development.

  4. Traumatic hypovolemic shock revisited: the spectrum of contrast-enhanced abdominal computed tomography findings and clinical implications for its management.

    Science.gov (United States)

    Higashi, Hiroki; Kanki, Akihiko; Watanabe, Shigeru; Yamamoto, Akira; Noda, Yasufumi; Yasokawa, Kazuya; Higaki, Atsushi; Tamada, Tsutomu; Ito, Katsuyoshi

    2014-10-01

    Hypovolemic shock is often seen in patients with severe blunt trauma who have suffered from blood circulation inadequate to maintain oxygen delivery to multiple organs. The early recognition and prompt management of hypovolemic shock in patients with multiple injuries are mandatory to improving prognosis and patient conditions. The diagnostic accuracy of computed tomography (CT) as a primary diagnostic tool is well established. The abdominal organs show several common and classic appearances on contrast-enhanced CT in patients with trauma. The hypovolemic shock complex is reported in the previous literature as decreased enhancement of the viscera, increased mucosal enhancement and luminal dilation of the small bowel, mural thickening and fluid-filled loops of the small bowel, the halo sign and flattening of the inferior vena cava, reduced aortic diameter, and peripancreatic edema. However, there have been controversial CT reports with contradictory appearances. Physicians understanding these findings could prompt alternative approaches to the early assessment and management of hypovolemic shock. The aim of this article is to illustrate common and well-known abdominal CT features in patients with traumatic hypovolemic shock, to discuss controversial CT signs in the pancreas and adrenal gland, and to describe CT findings' clinical implications when managing hypovolemic shock.

  5. Visualizing polymeric bioresorbable scaffolds with three-dimensional image reconstruction using contrast-enhanced micro-computed tomography.

    Science.gov (United States)

    Tu, Sheng; Hu, Fudong; Cai, Wei; Xiao, Liyan; Zhang, Linlin; Zheng, Hong; Jiang, Qiong; Chen, Lianglong

    2017-05-01

    There are no previous studies showing how to visualize polymeric bioresorbable scaffolds (BRSs) by micro-computed tomography (mCT). There are no previous studies showing how to visualize polymeric bioresorbable scaffolds (BRSs) by micro-computed tomography (mCT). This study aimed to explore the feasibility of detecting polymeric BRS with 3-dimensional reconstruction of BRS images by contrast-enhanced mCT and to determine the optimal imaging settings. BRSs, made of poly-L-lactic acid (PLLA), were implanted in coronary bifurcation models. Five treatments were conducted to examine an optimal condition for imaging BRSs: Baseline treatment, samples were filled with normal saline and scanned with mCT immediately; Treatment-1, -2, -3 and -4, samples were filled with contrast medium and scanned with mCT immediately and 1, 2 and 3 h thereafter, corresponding to soaking time of contrast medium of 0, 1, 2 and 3 h. Compared to Baseline, mCT scanning completely discriminate the scaffold struts from the vascular lumen immediately after filling the samples with contrast agent but not from the vascular wall until the contrast agent soaking time was more than 2 h (Treatment-3 and -4). By setting 10-15 HU as a cut-point of CT values, the scaffold strut detectable rate at Baseline and Teatment-1, -2, -3 and -4 were 1.23 ± 0.31%, 1.65 ± 0.26%, 58.14 ± 12.84%, 97.97 ± 1.43% and 98.90 ± 0.38%, respectively (Treatment-3 vs. Treatment-2, p scaffold struts from the surrounding structures in the phantom samples.

  6. Contrast-enhanced Ultrasound in Detecting Endoleaks with Failed Computed Tomography Angiography Diagnosis after Endovascular Abdominal Aortic Aneurysm Repair

    Institute of Scientific and Technical Information of China (English)

    Xiao Yang; Yue-Xin Chen; Bo Zhang; Yu-Xin Jiang; Chang-Wei Liu; Rui-Na Zhao; Qiong Wu

    2015-01-01

    Background:Endovascular aneurysm repair (EVAR) is one of the first-line therapies of abdominal aortic aneurysms.Postoperative endoleak is the most common complication of EVAR.Computed tomography angiography (CTA),which is routine for follow-up,has side effects (e.g.,radiation) and also has a certain percentage of missed diagnosis.Preliminary studies on contrast-enhanced ultrasound (CEUS) have shown that the sensitivity of CEUS for detecting endoleak is no lower than that of CTA.To investigate the advantages of CEUS,we conducted CEUS examinations of post-EVAR cases in which CTA failed to detect endoleak or could not verify the type of endoleak.Methods:Post-EVAR patients,who were clinically considered to have endoleak and met the inclusion criteria were enrolled between March 2013 and November 2014.All of the patients underwent color Doppler flow imaging (CDFI) and a CEUS examination.Size,location,microbubble dispersion,and hemodynamic characteristics of leaks were recorded.Comparison between the diagnosis of CEUS and CDFI was conducted using Fisher's exact test and clinical outcomes of all patients were followed up.Results:Sixteen patients were enrolled,and 12 (75%) had endoleaks with verified types by CEUS.Among 12 cases of endoleaks were positive by CEUS,10 were CDFI-positive,and the four CEUS-negative cases were all negative by CDFI.The diagnostic values of CEUS and CDFI were statistically different (P =0.008).Six patients with high-pressure endoleaks received endovascular re-intervention guided by CEUS results.One patient with type Ⅲ endoleak had open surgery when endovascular repair failed.Conclusions:CEUS is a new,safe,and effective means for detection ofendoleaks post-EVAR.This technique can be used as a supplement for routine CTA follow-up to provide more detailed information on endoleak and its category.

  7. Hepatic Blood Perfusion Estimated by Dynamic Contrast-Enhanced Computed Tomography in Pigs Limitations of the Slope Method

    Science.gov (United States)

    Winterdahl, Michael; Sørensen, Michael; Keiding, Susanne; Mortensen, Frank V.; Alstrup, Aage K. O.; Hansen, Søren B.; Munk, Ole L.

    2012-01-01

    Objective To determine whether dynamic contrast-enhanced computed tomography (DCE-CT) and the slope method can provide absolute measures of hepatic blood perfusion from hepatic artery (HA) and portal vein (PV) at experimentally varied blood flow rates. Materials and Methods Ten anesthetized 40-kg pigs underwent DCE-CT during periods of normocapnia (normal flow), hypocapnia (decreased flow), and hypercapnia (increased flow), which was induced by adjusting the ventilation. Reference blood flows in HA and PV were measured continuously by surgically-placed ultrasound transit-time flowmeters. For each capnic condition, the DCE-CT estimated absolute hepatic blood perfusion from HA and PV were calculated using the slope method and compared with flowmeter based absolute measurements of hepatic perfusions and relative errors were analyzed. Results The relative errors (mean±SEM) of the DCE-CT based perfusion estimates were −21±23% for HA and 81±31% for PV (normocapnia), 9±23% for HA and 92±42% for PV (hypocapnia), and 64±28% for HA and −2±20% for PV (hypercapnia). The mean relative errors for HA were not significantly different from zero during hypo- and normocapnia, and the DCE-CT slope method could detect relative changes in HA perfusion between scans. Infusion of contrast agent led to significantly increased hepatic blood perfusion, which biased the PV perfusion estimates. Conclusions Using the DCE-CT slope method, HA perfusion estimates were accurate at low and normal flow rates whereas PV perfusion estimates were inaccurate and imprecise. At high flow rate, both HA perfusion estimates were significantly biased. PMID:22836307

  8. Is the KUB radiograph redundant for investigating acute ureteric colic in the non-contrast enhanced computed tomography era?

    Energy Technology Data Exchange (ETDEWEB)

    Kennish, S.J.; Bhatnagar, P. [Department of Radiology, St James' University Hospital, Leeds (United Kingdom); Wah, T.M. [Department of Radiology, St James' University Hospital, Leeds (United Kingdom)], E-mail: Tze.wah@leedsth.nhs.uk; Bush, S. [Department of Emergency Medicine, St James' University Hospital, Leeds (United Kingdom); Irving, H.C. [Department of Radiology, St James' University Hospital, Leeds (United Kingdom)

    2008-10-15

    Aim: To establish whether non-contrast enhanced computed tomography (NCCT) renders the kidneys-ureters-bladder (KUB) radiograph redundant as the initial imaging investigation for suspected acute ureteric colic. Materials and methods: The imaging investigations for 120 patients consecutively admitted to an emergency department-led clinical decisions unit (CDU) with suspected acute ureteric colic were retrospectively reviewed. A multidisciplinary meeting reviewed the findings and recommended that KUB radiographs should not be routinely performed prior to NCCT. Prospective assessment of 116 consecutive patients admitted over a comparable period was then undertaken. Results: In the retrospective group, 61 (50.8%) patients had calculi to account for symptoms (positive NCCT) and 59 (49.2%) patients did not have stone disease (negative NCCT). Ninety (75%) patients had a KUB radiograph prior to NCCT. However, in 46 (38% of total) of these patients the NCCT was negative for stones, and therefore, they had been subjected to an unnecessary radiographic examination. These results prompted a change in practice. In the subsequent and prospectively studied group, preliminary KUB radiographs were performed in only 6% of the patients, with no significant change in the positive NCCT rate (50.8 versus 51.7%) or the total number of examinations performed (120 versus 116). Conclusion: NCCT should be the initial imaging examination for acute ureteric colic. Up to 50% of patients with clinical suspicion do not have stone disease, and therefore, preliminary KUB radiographs with attendant radiation and cost implications are unjustified. Preliminary KUB radiographs can be omitted from the imaging pathway with no resultant indication creep or increase in demand for NCCT examinations.

  9. Comparison between perfusion computed tomography and dynamic contrast-enhanced magnetic resonance imaging in assessing glioblastoma microvasculature.

    Science.gov (United States)

    Jia, Zhong Zheng; Shi, Wei; Shi, Jin Long; Shen, Dan Dan; Gu, Hong Mei; Zhou, Xue Jun

    2017-02-01

    Perfusion computed tomography (PCT) and dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) provide independent measurements of biomarkers related to tumor perfusion. The aim of this study was to compare the two techniques in assessing glioblastoma microvasculature. Twenty-five patients diagnosed with glioblastoma (14 males and 11 females; 51±11years old, ranging from 33 to 70 years) were includede in this prospective study. All patients underwent both PCT and DCE-MRI. Imaging was performed on a 256-slice CT scanner and a 3-T MRI system. PCT yielded permeability surface-area product (PS) using deconvolution physiological models; meanwhile, DCE-MRI determined volume transfer constant (K(trans)) using the Tofts-Kermode compartment model. All cases were submitted to surgical intervention, and CD105-microvascular density (CD105-MVD) was measured in each glioblastoma specimen. Then, Spearman's correlation coefficients and Bland-Altman plots were obtained for PS, K(trans) and CD105-MVD. P<0.05 was considered statistically significant. Tumor PS and K(trans) values were correlated with CD105-MVD (r=0.644, P<0.001; r=0.683, P<0.001). In addition, PS was correlated with K(trans) in glioblastoma (r=0.931, P<0.001). Finally, Bland-Altman plots showed no significant differences between PS and K(trans) (P=0.063). PCT and DCE-MRI measurements of glioblastoma perfusion biomarkers have similar results, suggesting that both techniques may have comparable utility. Therefore, PCT may serve as an alternative modality to DCE-MRI for the in vivo evaluation of glioblastoma microvasculature. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  10. Angiotomografía computada multicorte 64 en patología de la arteria aorta The 64 multi detector row computed tomography in aortic patology diagnostic

    Directory of Open Access Journals (Sweden)

    Diego Haberman

    2008-09-01

    Full Text Available La angiotomografía computada representa una metodología diagnóstica de gran utilidad que ha cobrado mayor importancia con los nuevos avances tecnológicos. La tomografía computada multicorte con 64 hileras de detectores nos brinda la posibilidad de estudiar con gran precisión y enorme detalle estructuras cada vez más pequeñas, ofreciendo una nueva perspectiva en el diagnóstico de la patología aórtica.The angio computed tomography represents a great utility diagnostic method that has reached greater importance with its technological new developments. The 64 multi detector row computed tomography allows the evaluation with great precision and detail of very small structures, offering a new perspective in aortic patology diagnostic.

  11. Dynamic contrast-enhanced computed tomography as a potential biomarker in patients with metastatic renal cell carcinoma: preliminary results from the Danish Renal Cancer Group Study-1

    DEFF Research Database (Denmark)

    Mains, Jill Rachel; Donskov, Frede; Pedersen, Erik Morre;

    2014-01-01

    OBJECTIVES: The aim of this study was to explore the impact of dynamic contrast-enhanced (DCE) computer tomography (CT) as a biomarker in metastatic renal cell carcinoma (mRCC). MATERIALS AND METHODS: Twelve patients with favorable or intermediate Memorial Sloan Kettering Cancer Center risk group...

  12. Visualisation of passive middle ear implants by cone beam and multi-detector computed tomography: a comparative in vitro study

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen, T.D.; Koesling, S. [University of Halle-Wittenberg, Department of Radiology, Halle Saale (Germany); Mlynski, R. [Head and Neck Surgery ' ' Otto Koerner' ' , Department of Otorhinolaryngology, Rostock (Germany); Plontke, S.K. [University of Halle-Wittenberg, Department of Otorhinolaryngology, Head and Neck Surgery, Halle Saale (Germany)

    2016-12-15

    Modern passive middle ear titanium prostheses are filigree structures, resulting in poorer depiction on CT compared to prostheses used in the past. We compared the visibility of newer prostheses on cone beam CT (CBCT) to multi-detector CT (MDCT) with standard and lower dose in vitro, and analysed image noise and metal artefacts. Six different titanium middle ear prostheses (three partial and one total ossicular replacement prostheses, two stapes prostheses) were implanted twice in formalin-fixed head specimens - first correctly and then with displacement. Imaging was performed using standard CBCT and MDCT as well as MDCT with lower dose (36 single imaging investigations). Images were analysed with knowledge of the used types of middle ear prostheses, but blinded with respect to the positioning in the specific case. On all images the type of prostheses and their positions could be clearly recognized. Their identifiability including their details was rated as statistically significantly higher for all CBCT investigations than for MDCT. MDCT with lower dose showed the worst results. No statistical differences were found in image noise and metal artefacts. If available, CBCT should be preferred over MDCT in diagnostic evaluation of passive middle ear prostheses. (orig.)

  13. Prediction of presence of kidney disease in patients undergoing intravenous iodinated contrast enhanced computed tomography: a validation study

    Energy Technology Data Exchange (ETDEWEB)

    Schreuder, Sanne M.; Stoker, Jaap; Bipat, Shandra [University of Amsterdam, Department of Radiology, Academic Medical Centre, G1-212, Amsterdam (Netherlands)

    2017-04-15

    To validate two previously presented models containing risk factors to identify patients with estimated glomerular filtration rate (eGFR) <60 ml/min/1.73 m{sup 2} or eGFR <45 ml/min/1.73 m{sup 2}. In random patients undergoing intravenous contrast-enhanced computed tomography (CECT) the following risk factors were assessed: history of urological/nephrological disease, hypertension, diabetes mellitus, anaemia, congestive heart failure, other cardiovascular disease or multiple myeloma or Waldenstroem disease. Data on kidney function, age, gender and type and indication of CECT were also registered. We studied two models: model A - diabetes mellitus, history of urological/nephrological disease, cardiovascular disease, hypertension; model B - diabetes mellitus, history of urological/nephrological disease, age >75 years and congestive heart failure. For each model, associations with eGFR <60 ml/min/1.73 m{sup 2} or eGFR <45 ml/min/1.73 m{sup 2} was studied. A total of 1,001 patients, mean age 60.36 years were included. In total, 92 (9.2 %) patients had an eGFR <60 ml/min/1.73 m{sup 2} and 11 (1.1 %) patients an eGFR <45 ml/min/1.73 m{sup 2}. Model A detected 543 patients: 81 with eGFR <60 ml/min/1.73 m{sup 2} (missing 11) and all 11 with eGFR <45 ml/min/1.73 m{sup 2}. Model B detected 420 patients: 70 (missing 22) with eGFR <60 ml/min/1.73 m{sup 2} and all 11 with eGFR <45 ml/min/1.73 m{sup 2}. Associations were significant (p < 0.05). Model B resulted in the lowest superfluous eGFR measurements while detecting all patients with eGFR <45 ml/min/1.73 m{sup 2} and nearly all with eGFR <60 ml/min/1.73 m{sup 2}. (orig.)

  14. Gastric large cell neuroendocrine carcinoma with venous tumor thrombus: the value of PET/CT and contrast-enhanced computed tomography.

    Science.gov (United States)

    Song, Le; Jin, Zhu; Zhang, Weifang; Zhang, Yanyan

    2015-01-01

    Venous involvement is commonly detected microscopically on gastric neuroendocrine carcinomas (NECs), but related imaging studies have been rarely documented. We report a rare case of gastric large cell NEC with tumor thrombi in gastric and splenic veins, elevated serum alpha fetoprotein, and multiple hepatic nodules. In this case, (18)F-fluorodeoxyglucose positron emission tomography combined with contrast-enhanced computed tomography provided valuable information on tumor staging. Copyright © 2015 Elsevier Inc. All rights reserved.

  15. 超声造影和增强CT诊断肾盂癌的比较研究%Comparative study of renal pelvic carcinoma by contrast-enhanced ultrasonography and contrast-enhanced computed tomography

    Institute of Scientific and Technical Information of China (English)

    王晓; 黄备建; 李丛; 燕翠菊; 范培丽; 李超伦; 王文平

    2012-01-01

    目的 对比分析超声造影和增强CT显示肾盂癌血流灌注特点的异同点,探讨超声造影的临床应用价值.方法 对40例行超声造影和增强CT检查并经手术病理证实的肾盂癌病例进行回顾性分析,观察肿块的增强时相和增强方式,包括肿块的增强、消退时间和灌注表现.结果 超声造影显示皮质期40个肿块全部增强;同步增强14个,缓慢增强26个;达峰值呈低回声31个,高回声4个,等回声5个;实质期快速消退35个,同步消退2个,缓慢消退3个;显示最小病灶为1.5 cm.增强CT显示38个肿块增强,多呈轻、中度均匀强化,增强程度低于周围肾实质.超声造影诊断准确率为77.5%(31/40),增强CT诊断准确率为82.5%(33/40),两者比较差异无统计学意义(P>0.05).结论 超声造影和增强CT对肾盂癌均有较高的诊断准确率,联合检测可提高早期诊断的检出率.%Objective To compare and analyze the similarities and differences of the blood perfusion characteristics of the renal pelvic carcinoma displayed by contrast-enhanced ultrasonography(CEUS) and contrast-enhanced computed tomography(CECT).Methods The characteristics of CEUS and CECT were anzlyzed retrospectively in 40 confirmed renal pelvic carcinoma cases by operation and pathology.The modality and phases of enhancement,including wash-in and washout time,as well as the perfusion appearances,were observed by CEUS and CECT.Results CEUS detected the cortical phase enhancement in all renal pelvic tumors,including synchronously enhancement in 14 tumors and delayed enhancement in 26 tumors.At peak times,hypoechogenicity compared to the normal renal cortex was shown in 31 tumors,hyperechogenicity in 4 tumors and isoechogenicity in 5 tumors.Fast wash-out in medulla phase was displayed in 35 tumors,isochronously wash-out in 2 tumors and delayed wash-out in 3 tumors.The minimum diameter in 40 renal pelvic tumors was 1.5 cm.CECT showed the enhancement in 38 tumors

  16. Dynamic contrast-enhanced computed tomography as a potential biomarker in patients with metastatic renal cell carcinoma: preliminary results from the Danish Renal Cancer Group Study-1

    DEFF Research Database (Denmark)

    Mains, Jill Rachel; Donskov, Frede; Pedersen, Erik Morre

    2014-01-01

    OBJECTIVES: The aim of this study was to explore the impact of dynamic contrast-enhanced (DCE) computer tomography (CT) as a biomarker in metastatic renal cell carcinoma (mRCC). MATERIALS AND METHODS: Twelve patients with favorable or intermediate Memorial Sloan Kettering Cancer Center risk group...... and clear cell mRCC participating in an ongoing prospective randomized phase II trial comprising interleukin-2-based immunotherapy and bevacizumab were included in this preliminary analysis. All patients had a follow-up time of at least 2 years. Interpretation of DCE-CT (max slope method) was performed...... not reached, P = 0.031). CONCLUSIONS: Dynamic contrast-enhanced CT is a potential biomarker in patients with mRCC. High baseline BF and reductions in BF and BV during early treatment are associated with improved outcome. Large-scale studies are required....

  17. Massive splenic infarction and splenic venous thrombosis observed in a patient with acute splenic syndrome of sickle cell traits on contrast-enhanced thin-slice computed tomography.

    Science.gov (United States)

    Hayashi, Takana Yamakawa; Matsuda, Izuru; Hagiwara, Kazuchika; Takayanagi, Tomoko; Hagiwara, Akifumi

    2016-09-01

    We report a case of splenic infarction in a patient with sickle cell traits (SCT), focusing on the computed tomography (CT) findings. The patient was an African-American man in his twenties with no past medical history who experienced sudden left upper quadrant pain while climbing a mountain (over 3000 m above sea level). Dynamic contrast-enhanced CT revealed massive non-segmental splenic infarction accompanied with nodule-like preserved splenic tissue. The region of splenic infarction did not coincide with the arterial vascular territory and differed from the features of infarction caused by large arterial embolism. In addition, thrombotic occlusion of the distal splenic vein was depicted on plain and contrast-enhanced thin-slice CT images. Early-phase contrast-enhanced images also showed inhomogeneous enhancement of the hepatic parenchyma. The patient's symptoms improved with conservative therapy. A hemoglobin electrophoresis test confirmed the diagnosis of SCT. SCT is usually asymptomatic, but hypoxic environments may induce acute splenic syndrome, which is commonly manifested as splenic infarction. We observed splenic venous thrombosis and inhomogeneous hepatic parenchymal enhancement in addition to a huge splenic infarction in our patient. To the best of our knowledge, this is the first report describing the specific imaging findings, particularly splenic venous thrombosis and inhomogeneous hepatic parenchymal enhancement, of acute splenic syndrome in a patient with previously undiagnosed SCT. These findings demonstrate the pathophysiology of SCT, and may help with the diagnosis of this disease.

  18. Correctness of multi-detector-row computed tomography for diagnosing mechanical prosthetic heart valve disorders using operative findings as a gold standard

    Energy Technology Data Exchange (ETDEWEB)

    Tsai, I.Chen [Taichung Veterans General Hospital, Department of Radiology, Taichung (China); Institute of Clinical Medicine and Faculty of Medicine, National Yang-Ming University, Taipei (China); Lin, Yung-Kai; Chang, Yen; Wang, Chung-Chi; Hsieh, Shih-Rong; Wei, Hao-Ji; Tsai, Hung-Wen [Taichung Veterans General Hospital, Section of Cardiovascular Surgery, Cardiovascular Center, Taichung (China); Fu, Yun-Ching; Jan, Sheng-Ling [Institute of Clinical Medicine and Faculty of Medicine, National Yang-Ming University, Taipei (China); Taichung Veterans General Hospital, Section of Pediatric Cardiology, Department of Pediatrics, Taichung (China); Wang, Kuo-Yang [Taichung Veterans General Hospital, Section of General Cardiology, Cardiovascular Center, Taichung (China); Chung-Shan Medical University, Department of Medicine, Taichung (China); Chen, Min-Chi; Chen, Clayton Chi-Chang [Taichung Veterans General Hospital, Department of Radiology, Taichung (China); Central Taiwan University of Science and Technology, Department of Radiological Technology, Taichung (China)

    2009-04-15

    The purpose was to compare the findings of multi-detector computed tomography (MDCT) in prosthetic valve disorders using the operative findings as a gold standard. In a 3-year period, we prospectively enrolled 25 patients with 31 prosthetic heart valves. MDCT and transthoracic echocardiography (TTE) were done to evaluate pannus formation, prosthetic valve dysfunction, suture loosening (paravalvular leak) and pseudoaneurysm formation. Patients indicated for surgery received an operation within 1 week. The MDCT findings were compared with the operative findings. One patient with a Bjoerk-Shiley valve could not be evaluated by MDCT due to a severe beam-hardening artifact; thus, the exclusion rate for MDCT was 3.2% (1/31). Prosthetic valve disorders were suspected in 12 patients by either MDCT or TTE. Six patients received an operation that included three redo aortic valve replacements, two redo mitral replacements and one Amplatzer ductal occluder occlusion of a mitral paravalvular leak. The concordance of MDCT for diagnosing and localizing prosthetic valve disorders and the surgical findings was 100%. Except for images impaired by severe beam-hardening artifacts, MDCT provides excellent delineation of prosthetic valve disorders. (orig.)

  19. Flat-detector computed tomography in the assessment of intracranial stents: comparison with multi detector CT and conventional angiography in a new animal model.

    Science.gov (United States)

    Struffert, Tobias; Ott, Sabine; Adamek, Edyta; Schwarz, Marc; Engelhorn, Tobias; Kloska, Stephan; Deuerling-Zheng, Yu; Doerfler, Arnd

    2011-08-01

    Careful follow up is necessary after intracranial stenting because in-stent restenosis (ISR) or residual stenosis (RS) is not rare. A minimally invasive follow-up imaging technique is desirable. The objective was to compare the visualisation of stents in Flat Detector-CT Angiography (FD-CTA) after intravenous contrast medium injection (i.v.) with Multi Detector Computed Tomography Angiography (MD-CTA) and Digital Subtracted Angiography (DSA) in an animal model. Stents were implanted in the carotid artery of 12 rabbits. In 6 a residual stenosis (RS) was surgically created. Imaging was performed using FD-CTA, MD-CTA and DSA. Measurements of the inner and outer diameter and cross-section area of the stents were performed. Stenosis grade was calculated. In subjective evaluation FD-CTA was superior to MD-CTA. FD-CTA was more accurate compared with DSA than MD-CTA. Cross-sectional area of the stent lumen was significantly larger (p < 0.05) in FD-CTA in comparison to MD-CTA. Accurate evaluation of stenosis was impossible in MD-CTA. There was no statistically significant difference in the stenosis grade of DSA and FD-CTA. Our results show that visualisation of stent and stenosis using intravenous FD-CTA compares favourably with DSA and may replace DSA in the follow-up of patients treated with intracranial stents.

  20. Multi-detector computed tomography is equivalent to trans-oesophageal echocardiography for the assessment of the aortic annulus before transcatheter aortic valve implantation

    Energy Technology Data Exchange (ETDEWEB)

    Rixe, Johannes; Schmitt, Joern; Neumann, Thomas; Hamm, Christian W.; Rolf, Andreas [Kerckhoff Heart and Thorax Center, Department of Cardiology, Bad Nauheim (Germany); University Hospital of Giessen and Marburg, Site Giessen, Department of Internal Medicine I (Cardiology, Angiology), Giessen (Germany); Schuhbaeck, Annika; Nef, Holger M.; Achenbach, Stephan [University Hospital of Giessen and Marburg, Site Giessen, Department of Internal Medicine I (Cardiology, Angiology), Giessen (Germany); Liebetrau, Christoph; Moellmann, Helge; Szardien, Sebastian; Brandt, Roland [Kerckhoff Heart and Thorax Center, Department of Cardiology, Bad Nauheim (Germany); Schneider, Christian; Krombach, Gabriele [University Hospital of Giessen and Marburg, Department of Radiology, Giessen (Germany)

    2012-12-15

    In transcatheter aortic valve implantation (TAVI), assessment of the aortic annulus is mandatory. We sought to investigate the correlation between trans-oesophageal echocardiography (TEE) and multi-detector computed tomography (MDCT) for annulus diameter assessment before TAVI. A total of 122 patients (67 male, mean age 84 {+-} 6 years) underwent MDCT and TEE for TAVI planning. In TEE annulus diameters were obtained in a long-axis view at diastole. MDCT data were evaluated using MPR images, and corresponding projections were adjusted for MDCT and TEE. Patients were classified by the predominant localisation of aortic valve calcifications, and annulus diameters between TEE and MDCT were correlated. Additionally, the eccentricity of the aortic annulus was calculated. Mean eccentricity of the aortic annulus determined by MDCT was 0.34 {+-} 0.17, with no difference according to valve calcification. Regarding the aortic annulus diameter, the mean values measured were 24.3 {+-} 2.1 mm in MDCT and 24.0 {+-} 2.5 mm in TEE (P < 0.0001 for agreement). Independent of the pattern of aortic valve calcification, close correlation is found between CT and TEE measurements of the aortic annulus diameter. In addition, CT demonstrates the non-circular shape of the aortic annulus. (orig.)

  1. Comparison of MDCTA (16-slice multi-detector row computed tomography arthrography) and MRA (magnetic resonance arthrography) for detecting labral lesions of the shoulder

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Seung A; Cha, Jang Gyu; Hong, Hyun Sook; Choi, Deuk Lin; Park, Jai Soung; Lee, Hae Kyung; Kim, Dae Ho [Soonchunhyang University Bucheon Hospital, Bucheon (Korea, Republic of)

    2007-11-15

    To compare the accuracy of 16-slice multi-detector row computed tomographic arthrography (MDCTA) and magnetic resonance arthrography (MRA) for making the diagnosis and classification of labroligamentous injuries. This study is a prospective series that used MRA and MDCTA to examine 23 patients who complained of shoulder instability. Two radiologists independently analyzed the MRA and MDCTA. The sensitivity, specificity, accuracy, positive and negative predictive values were calculated from the arthrograms and the arthroscopic findings. The images of MDCTA and MRA corresponded with the findings on arthroscopy. Both imaging modalities had the same sensitivity for detecting Bankart lesions (n = 10, 90%) and posterior labral tears (n = 2, 50%) on McNemar test ({rho} = 1.00). For superior labrum anterior-to-posterior (SLAP) lesions, 6 MRA cases and 4 MDCTA cases corresponded with the arthroscopic findings. The difference between the sensitivities of MDCTA (66.7%) and MRA (100%) was not significant ({rho} 0.09). We suggest that the sensitivity of diagnosing labral lesions that induce shoulder instability is similar for MDCTA and MRA. MDCTA is effective for diagnosing and evaluating shoulder instability.

  2. Acute aortic syndromes: Role of multi-detector row CT

    Energy Technology Data Exchange (ETDEWEB)

    Salvolini, Luca; Renda, Pietro [Department of Radiology, University ' Politecnica delle Marche' , Ancona (Italy); Fiore, Davide [Department of Radiology, University of Padova, Padova (Italy); Scaglione, Mariano [Emergency and Trauma CT Section, Department of Radiology, Cardarelli Hospital, Naples (Italy); Piccoli, GianPiero [Cardiosurgery Division, Ospedali Riuniti ' Torrette-Lancisi-Salesi' , Ancona (Italy); Giovagnoni, Andrea [Department of Radiology, University ' Politecnica delle Marche' , Ancona (Italy)], E-mail: a.giovagnoni@univpm.it

    2008-03-15

    Acute thoracic aortic syndromes encompass a spectrum of emergencies including aortic dissection, intramural haematoma, penetrating atherosclerotic ulcer and aneurysm rupture. All these life-threatening conditions require prompt diagnosis and appropriate management. To date multi-detector row Computed Tomography represents a valuable diagnostic tool especially in the emergency setting. This paper focus on the use of multi-detector row Computed Tomography in the evaluation of acute thoracic aortic syndromes and illustrates the key imaging findings related to each disease.

  3. Role of multiphasic multi-detector computed tomography (MDCT in the diagnosis and staging of solid neoplastic renal masses

    Directory of Open Access Journals (Sweden)

    Manal H. Wahba

    2015-03-01

    Conclusion: Multiphase multislice computed tomography combined with CT angiography and CT urography have a major role in solid renal neoplastic masses’ diagnosis, characterization and differentiating benign and malignant tumors.

  4. Gd-EOB-DTPA-enhanced 3.0-Tesla MRI findings for the preoperative detection of focal liver lesions: Comparison with iodine-enhanced multi-detector computed tomography

    Science.gov (United States)

    Park, Hyong-Hu; Goo, Eun-Hoe; Im, In-Chul; Lee, Jae-Seung; Kim, Moon-Jib; Kwak, Byung-Joon; Chung, Woon-Kwan; Dong, Kyung-Rae

    2012-12-01

    The safety of gadolinium-ethoxybenzyl-diethylenetriamine-pentaacetic-acid (Gd-EOB-DTPA) has been confirmed, but more study is needed to assess the diagnostic accuracy of Gd-EOB-DTPA-enhanced magnetic resonance imaging (MRI) in patients with a hepatocellular carcinoma (HCC) for whom surgical treatment is considered or with a metastatic hepatoma. Research is also needed to examine the rate of detection of hepatic lesions compared to multi-detector computed tomography (MDCT), which is used most frequently to localize and characterize a HCC. Gd-EOB-DTPA-enhanced MRI and iodine-enhanced MDCT imaging were compared for the preoperative detection of focal liver lesions. The clinical usefulness of each method was examined. The current study enrolled 79 patients with focal liver lesions who preoperatively underwent MRI and MDCT. In these patients, there was less than one month between the two diagnostic modalities. Imaging data were taken before and after contrast enhancement in both methods. To evaluate the images, we analyzed the signal-to-noise ratio (SNR) and the contrast-to-noise ratio (CNR) in the lesions and the liver parenchyma. To compare the sensitivity of the two methods, we performed a quantitative analysis of the percentage signal intensity of the liver (PSIL) on a high resolution picture archiving and communication system (PACS) monitor (paired-samples t-test, p DTPA-enhanced MRI findings and the iodine-enhanced MDCT by using an adjusted x2 test. The SNRs, CNRs, and PSIL all had a greater detection rate in Gd-EOB-DTPA enhanced MRI than in iodine-enhanced MDCT. Hepatocyte-selective uptake was observed 20 minutes after the injection in the focal nodular hyperplasia (FNH, 9/9), adenoma (9/10), and highly-differentiated HCC (grade G1, 27/30). Rim enhancement was detected in all metastases (30/30). During the arterial and the delayed phases, good overall agreement between the gadoxetic-acid-enhanced MR and CT was observed (x2 test, p DTPA-enhanced MRI had a higher

  5. Diffusible iodine-based contrast-enhanced computed tomography (diceCT): an emerging tool for rapid, high-resolution, 3-D imaging of metazoan soft tissues.

    Science.gov (United States)

    Gignac, Paul M; Kley, Nathan J; Clarke, Julia A; Colbert, Matthew W; Morhardt, Ashley C; Cerio, Donald; Cost, Ian N; Cox, Philip G; Daza, Juan D; Early, Catherine M; Echols, M Scott; Henkelman, R Mark; Herdina, A Nele; Holliday, Casey M; Li, Zhiheng; Mahlow, Kristin; Merchant, Samer; Müller, Johannes; Orsbon, Courtney P; Paluh, Daniel J; Thies, Monte L; Tsai, Henry P; Witmer, Lawrence M

    2016-06-01

    Morphologists have historically had to rely on destructive procedures to visualize the three-dimensional (3-D) anatomy of animals. More recently, however, non-destructive techniques have come to the forefront. These include X-ray computed tomography (CT), which has been used most commonly to examine the mineralized, hard-tissue anatomy of living and fossil metazoans. One relatively new and potentially transformative aspect of current CT-based research is the use of chemical agents to render visible, and differentiate between, soft-tissue structures in X-ray images. Specifically, iodine has emerged as one of the most widely used of these contrast agents among animal morphologists due to its ease of handling, cost effectiveness, and differential affinities for major types of soft tissues. The rapid adoption of iodine-based contrast agents has resulted in a proliferation of distinct specimen preparations and scanning parameter choices, as well as an increasing variety of imaging hardware and software preferences. Here we provide a critical review of the recent contributions to iodine-based, contrast-enhanced CT research to enable researchers just beginning to employ contrast enhancement to make sense of this complex new landscape of methodologies. We provide a detailed summary of recent case studies, assess factors that govern success at each step of the specimen storage, preparation, and imaging processes, and make recommendations for standardizing both techniques and reporting practices. Finally, we discuss potential cutting-edge applications of diffusible iodine-based contrast-enhanced computed tomography (diceCT) and the issues that must still be overcome to facilitate the broader adoption of diceCT going forward.

  6. Evaluation of the characteristics of hepatic focal nodular hyperplasia: correlation between dynamic contrast-enhanced multislice computed tomography and pathological findings

    Directory of Open Access Journals (Sweden)

    Zhang HT

    2016-08-01

    Full Text Available Hai-Tao Zhang,1,* Xin-Yi Gao,2,* Qin-Sha Xu,1 Yu-Tang Chen,3 Yu-Piao Song,1 Zhen-Wei Yao2 1Department of Radiology, Jiangwan Hospital, 2Department of Radiology, Affiliated Huashan Hospital of Fudan University, Shanghai, 3Department of Radiology, Zhejiang Province Tumor Hospital, Hangzhou, People’s Republic of China *These authors contributed equally to this work Objective: To evaluate the characteristics of enhancement of focal nodular hyperplasia (FNH of the liver by analyzing the dynamic contrast-enhanced multislice computed tomography (MSCT features and correlating them with pathological findings.Patients and methods: Nine males and 16 females with pathologically confirmed FNH and complete preoperative contrast-enhanced MSCT data were recruited for this study. The imaging features of FNH on the pre- and postcontrast MSCT were analyzed by two experienced radiologists by consensus.Results: Pathology showed central scars and abnormal blood vessels in 17 and 21 of 25 lesions, respectively, while MSCT with multiphase enhancement showed central scars in eight of the 17 lesions (47.1% and abnormal arteries or draining veins in 13 of the 21 lesions (61.9%. Furthermore, abnormal draining veins in five lesions were found to be diagnostic, which is another important finding.Conclusion: Multiphase scanning can provide the panorama of FNH lesions and reveal their enhancement patterns and pathological characteristics. Abnormal blood vessels within or around the lesion are demonstrated more often than central scar, and both should be observed for FNH diagnosis. Keywords: liver, focal nodular hyperplasia, multislice computed tomography, pathological findings, contrast enhancement, abnormal vein

  7. Multi-detector row computed tomographic evaluation of a rare type of complete vascular ring: Double aortic arch with atretic left arch distal to the origin of left subclavian artery

    Energy Technology Data Exchange (ETDEWEB)

    Hung, Ying Ying; Fu, Ching Yun; Wei, Hao Ji; Tsai, I Chen; Chen, Clayton Chi Chang [Taichung Veterans General Hospital, Taichung (China)

    2013-10-15

    Double aortic arch with an atretic left arch distal to the origin of left subclavian artery was diagnosed with multi-detector row computed tomography (MDCT) in two children with dysphagia. This rare type of complete vascular ring is clinically important because it may be confused with right aortic arch in mirror imaging. Anatomic details of this rare type of complete vascular ring demonstrated on MDCT facilitated appropriate surgical treatment.

  8. Pancreatic neuroendocrine tumors: Correlation between the contrast-enhanced computed tomography features and the pathological tumor grade

    Energy Technology Data Exchange (ETDEWEB)

    Takumi, Koji, E-mail: takumi@m2.kufm.kagoshima-u.ac.jp [Department of Radiology, Kagoshima University Graduate School of Medical and Dental Sciences, 8-35-1 Sakuragaoka, Kagoshima City, 890-8544 (Japan); Fukukura, Yoshihiko [Department of Radiology, Kagoshima University Graduate School of Medical and Dental Sciences, 8-35-1 Sakuragaoka, Kagoshima City, 890-8544 (Japan); Higashi, Michiyo [Department of Human Pathology, Kagoshima University Graduate School of Medical and Dental Sciences, 8-35-1 Sakuragaoka, Kagoshima City, 890-8544 (Japan); Ideue, Junnichi; Umanodan, Tomokazu; Hakamada, Hiroto [Department of Radiology, Kagoshima University Graduate School of Medical and Dental Sciences, 8-35-1 Sakuragaoka, Kagoshima City, 890-8544 (Japan); Kanetsuki, Ichiro [Department of Radiology, Koseiren Hospital, 22-25 Tenpozancho, Kagoshima City, 890-0061 (Japan); Yoshiura, Takashi [Department of Radiology, Kagoshima University Graduate School of Medical and Dental Sciences, 8-35-1 Sakuragaoka, Kagoshima City, 890-8544 (Japan)

    2015-08-15

    Highlights: • Updated WHO classification divided pancreatic neuroendocrine tumors into G1, G2, and G3. • We investigate the relationship between CT findings and pathological tumor grades (G1 and G2). • A larger tumor size was associated with G2 pancreatic neuroendocrine tumors (PanNETs). • Non-hyperattenuation during the portal venous phase was associated with G2 PanNETs. - Abstract: Objective: To determine whether CT features can predict the pathological tumor grades of pancreatic neuroendocrine tumors (PanNETs) according to the recent WHO classification. Materials and methods: In all, 28 patients with histologically confirmed PanNETs underwent preoperative contrast CT examinations. Thirteen tumors were classified as G1 and 15 as G2. Two radiologists independently evaluated the CT features (tumor delineation, peripancreatic vascular involvement, upstream pancreatic duct dilatation, N (regional lymph node metastasis) and M (distant metastasis) grades, tumor homogeneity, cystic or necrotic change, and tumor conspicuity). The tumor sizes and Hounsfield unit values of all PanNETs during each phase on CT were measured by one radiologist. We compared the CT features between pathological tumor grades using Fisher's exact test for nominal scales and Mann–Whitney U test for ordinal scales or continuous variables. Additionally, we evaluated the performances of the CT findings and their combinations to diagnose G2 tumors. Results: G2 tumors showed significantly larger in tumor size than G1 tumors (p = 0.029). All 4 tumors with hepatic metastases were G2. Non-hyperattenuation compared with pancreatic parenchyma during portal venous phase (PVP) was significantly associated with G2 (p = 0.016). The accuracy for G2 diagnosis of tumor size (≥20 mm), M grade (M1), and tumor conspicuity (non-hyperattenuation during PVP) were 71%, 61%, and 71%, respectively, while the accuracy of their combination was 82%. Conclusion: Contrast-enhanced CT features (tumor size, M

  9. Data acquisition for experiments with multi-detector arrays

    Indian Academy of Sciences (India)

    A Chatterjee; Sushil Kamerkar; A K Jethra; S Padmini; M P Diwakar; S S Pande; M D Ghodgaonkar

    2001-07-01

    Experiments with multi-detector arrays have special requirements and place higher demands on computer data acquisition systems. In this contribution we discuss data acquisition systems with special emphasis on multi-detector arrays and in particular we describe a new data acquisition system, AMPS which we have developed recently which is in regular use in experiments at the Pelletron Laboratory, Mumbai. This includes the in-house development of a dedicated crate controller, PC interface card and software.

  10. Feasibility and accuracy of coronary imaging in elderly patients using the 64-row multi-detector computed tomography: a correlation study with conventional coronary angiography

    Institute of Scientific and Technical Information of China (English)

    Wei Ling CHAN; Kui Hian SIM; Chee Khoon LIEW; Sze Piaw CHIN; Tiong Kiam ONG; Seyfarth Tobias; Yean Yip FONG; Choon Kiat ANG; Houng Bang LIEW; Rapaee ANNUAR

    2006-01-01

    Background Elderly patients generally have higher occurrence of coronary calcification, increased heart rate and difficulty with prolonged breath-holding. The aim of our study was to investigate the feasibility and accuracy of using 64-row multi-detector computed tomography (MDCT) in the assessment of coronary artery stenoses in elderly patients. Methods One hundred and fifty two patients with suspected or known coronary artery disease were divided into 4 groups according to their age (Group A: 40-49 years,n=34; Group B: 50-59 years, n=57; Group C: 60-69 years, n=48; Group D: 70 years and above; n=13). Coronary CT angiography (CTA) using a 64-row MDCT was performed and the findings were compared with that of conventional coronary angiography (CCA).Using axial images, multi-planar reconstructions (MPR) and maximum intensity projections (MIP), coronary segments of lumen diameter = 1.5mm were analyzed for the presence of significant stenosis (= 50% ). Results Percentages of poor image quality from coronary CTA preventing reliable correlations with CCA were 21%, 14%, 19% and 62% in Groups A to D respectively. Patients in Group D had significantly higher calcium scores compared with the other groups (P<0.001). In patients where CTA images were of acceptable quality, percentages of accurate correlations with CCA were 89.8%, 93.4%, 86.6% and 78.0% for Groups A to D respectively.There were no significant difference in serum creatinine, heart rate and contrast volume between the 4 groups. Conclusions The 64-row MDCT coronary angiography was less accurate and feasible for patients aged 70 years or above due to heavy coronary calcification and inability to perform a satisfactory breath-hold. However, a high diagnostic accuracy with the MDCT is possible in patients aged less than 70 years.

  11. Multi-detector row computed tomography of the heart: does a multi-segment reconstruction algorithm improve left ventricular volume measurements?

    Energy Technology Data Exchange (ETDEWEB)

    Juergens, Kai Uwe; Maintz, David; Heimes, Britta; Fallenberg, Eva Maria; Heindel, Walter; Fischbach, Roman [University of Muenster, Department of Clinical Radiology, Muenster (Germany); Grude, Matthias [University of Muenster, Department of Cardiology and Angiology, Muenster (Germany); Boese, Jan M. [Siemens Medical Solutions, Forchheim (Germany)

    2005-01-01

    A multi-segment cardiac image reconstruction algorithm in multi-detector row computed tomography (MDCT) was evaluated regarding temporal resolution and determination of left ventricular (LV) volumes and global LV function. MDCT and cine magnetic resonance (CMR) imaging were performed in 12 patients with known or suspected coronary artery disease. Patients gave informed written consent for the MDCT and the CMR exam. MDCT data were reconstructed using the standard adaptive cardiac volume (ACV) algorithm as well as a multi-segment algorithm utilizing data from three, five and seven rotations. LV end-diastolic (LV-EDV) and end-systolic volumes and ejection fraction (LV-EF) were determined from short-axis image reformations and compared to CMR data. Mean temporal resolution achieved was 192{+-}24 ms using the ACV algorithm and improved significantly utilizing the three, five and seven data segments to 139{+-}12, 113{+-}13 and 96{+-}11 ms (P<0.001 for each). Mean LV-EDV was without significant differences using the ACV algorithm, the multi-segment approach and CMR imaging. Despite improved temporal resolution with multi-segment image reconstruction, end-systolic volumes were less accurately measured (mean differences 3.9{+-}11.8 ml to 8.1{+-}13.9 ml), resulting in a consistent underestimation of LV-EF by 2.3-5.4% in comparison to CMR imaging (Bland-Altman analysis). Multi-segment image reconstruction improves temporal resolution compared to the standard ACV algorithm, but this does not result in a benefit for determination of LV volume and function. (orig.)

  12. Pulmonary arterial hypertension in children: diagnosis using ratio of main pulmonary artery to ascending aorta diameter as determined by multi-detector computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Caro-Dominguez, Pablo; Manson, David E. [University of Toronto, Department of Diagnostic Imaging, The Hospital for Sick Children, Department of Medical Imaging, Toronto, ON (Canada); Compton, Gregory [University of Toronto, Department of Diagnostic Imaging, The Hospital for Sick Children, Department of Medical Imaging, Toronto, ON (Canada); Epworth Hospital, Epworth Medical Imaging, Richmond, VIC (Australia); Humpl, Tilman [University of Toronto, Division of Cardiology, Department of Pediatrics, The Hospital for Sick Children, Toronto, ON (Canada)

    2016-09-15

    The ratio of the transverse diameter of the main pulmonary artery (MPA) to ascending aorta as determined at multi-detector CT is a tool that can be used to assess the pulmonary arterial size in cases of pulmonary arterial hypertension in children. To establish a ratio of MPA to ascending aorta diameter using multi-detector CT imaging suggestive of pulmonary arterial hypertension in children. We hypothesize that a defined ratio of MPA to ascending aorta is identifiable on multi-detector CT and that higher ratios can be used to reliably diagnose the presence of pulmonary arterial hypertension in children. We calculated the multi-detector CT ratio of MPA to ascending aorta diameter in 44 children with documented pulmonary arterial hypertension by right heart catheterization and in 44 age- and gender-matched control children with no predisposing factors for pulmonary arterial hypertension. We compared this multi-detector-CT-determined ratio with the MPA pressure in the study group, as well as with the ratio of MPA to ascending aorta in the control group. A threshold ratio value was calculated to accurately identify children with pulmonary arterial hypertension. Children with documented primary pulmonary arterial hypertension have a significantly higher ratio of MPA to ascending aorta (1.46) than children without pulmonary arterial hypertension (1.11). A ratio of 1.3 carries a positive likelihood of 34 and a positive predictive value of 97% for the diagnosis of pulmonary arterial hypertension. The pulmonary arteries were larger in children with pulmonary arterial hypertension than in a control group of normal children. A CT-measured ratio of MPA to ascending aorta of 1.3 should raise the suspicion of pulmonary arterial hypertension in children. (orig.)

  13. Role of contrast enhanced ultrasound in detection of abdominal aortic abnormalities in comparison with multislice computed tomography

    Institute of Scientific and Technical Information of China (English)

    Dirk-André Clevert; Kerstin Schick; CHEN Min-hua; ZHU Qing-li; Maximilian Reiser

    2009-01-01

    @@ dissection;abdominal aortic aneurysm;aorto-caval fistula;inflammatory abdominal aortic aneurysm Conventional ultrasound (US) is the most widely used imaging modality in routine clinical practice worldwide.The limitations of conventional ultrasound in the detection of aortic lesions versus multi-slice computed tomography angiography (MS-CTA) are well known.

  14. Differentiation between tuberculosis and leukemia in abdominal and pelvic lymph nodes: evaluation with contrast-enhanced multidetector computed tomography

    Directory of Open Access Journals (Sweden)

    Ge Zhang

    2015-03-01

    Full Text Available PURPOSE: To compare the characteristics of tubercular vs. leukemic involvement of abdominopelvic lymph nodes using multidetector computed tomography (CT. MATERIALS AND METHODS: We retrospectively reviewed multidetector computed tomography features including lymph node size, shape, enhancement patterns, and anatomical distribution, in 106 consecutive patients with newly diagnosed, untreated tuberculosis (55 patients; 52% or leukemia (51 patients; 48%. In patients with leukemia, 32 (62.7% had chronic lymphocytic leukemia, and 19 (37.3% had acute leukemias; of these, 10 (19.6% had acute myeloid leukemia, and 9 (17.6% had acute lymphocytic leukemia. RESULTS: The lower para-aortic (30.9% for tuberculosis, 63.2% for acute leukemias and 87.5% for chronic lymphocytic leukemia and inguinal (9.1% for tuberculosis, 57.9% for acute leukemias and 53.1% for chronic lymphocytic leukemia lymph nodes were involved more frequently in the three types of leukemia than in tuberculosis (both with p <0.017. Tuberculosis showed peripheral enhancement, frequently with a multilocular appearance, in 43 (78.2% patients, whereas patients with leukemia (78.9% for acute myeloid leukemia and acute lymphocytic leukemia, 87.5% for chronic lymphocytic leukemia demonstrated predominantly homogeneous enhancement (both with p <0.017. For the diagnosis of tuberculosis, the analysis showed that a peripheral enhancement pattern had a sensitivity of 78.2%, a specificity of 100%, and an accuracy of 88.7%. For the diagnosis of leukemia, the analysis showed that a homogeneous enhancement pattern was associated with a sensitivity of 84.3%, a specificity of 94.5%, and an accuracy of 89.6%. CONCLUSION: Our findings indicate that the anatomical distribution and enhancement patterns of lymphadenopathy seen on multidetector computed tomography are useful for differentiating between untreated tuberculosis and leukemia of the abdominopelvic lymph nodes.

  15. Measurements of pericardial adipose tissue using contrast enhanced cardiac multidetector computed tomography—comparison with cardiac magnetic resonance imaging

    DEFF Research Database (Denmark)

    Elming, Marie Bayer; Lønborg, Jacob; Rasmussen, Thomas

    2013-01-01

    Recent studies have suggested that pericardial adipose tissue (PAT) located in close vicinity to the epicardial coronary arteries may play a role in the development of coronary artery disease. PAT has primarily been measured with cardiac magnetic resonance imaging (CMRI) or with non......-contrast cardiac multidetector computered tomography (MDCT) images. The aim of this study was to validate contrast MDCT derived measures of total PAT volume by a comparison to CMRI. In 52 patients, aged 60 years (34-81 years), Body Mass Index 28 kg/m(2) (18-39), and with stable ischemic heart disease, paired MDCT...

  16. Contrast-enhanced microwave imaging of breast tumors: a computational study using 3D realistic numerical phantoms

    Science.gov (United States)

    Shea, J. D.; Kosmas, P.; Van Veen, B. D.; Hagness, S. C.

    2010-07-01

    The detection of early-stage tumors in the breast by microwave imaging is challenged by both the moderate endogenous dielectric contrast between healthy and malignant glandular tissues and the spatial resolution available from illumination at microwave frequencies. The high endogenous dielectric contrast between adipose and fibroglandular tissue structures increases the difficulty of tumor detection due to the high dynamic range of the contrast function to be imaged and the low level of signal scattered from a tumor relative to the clutter scattered by normal tissue structures. Microwave inverse scattering techniques, used to estimate the complete spatial profile of the dielectric properties within the breast, have the potential to reconstruct both normal and cancerous tissue structures. However, the ill-posedness of the associated inverse problem often limits the frequency of microwave illumination to the UHF band within which early-stage cancers have sub-wavelength dimensions. In this computational study, we examine the reconstruction of small, compact tumors in three-dimensional numerical breast phantoms by a multiple-frequency inverse scattering solution. Computer models are also employed to investigate the use of exogenous contrast agents for enhancing tumor detection. Simulated array measurements are acquired before and after the introduction of the assumed contrast effects for two specific agents currently under consideration for breast imaging: microbubbles and carbon nanotubes. Differential images of the applied contrast demonstrate the potential of the approach for detecting the preferential uptake of contrast agents by malignant tissues.

  17. USE OF CONTRAST-ENHANCED COMPUTED TOMOGRAPHY TO STUDY THE CRANIAL MIGRATION OF A LUMBOSACRAL INJECTATE IN CADAVER DOGS.

    Science.gov (United States)

    Kawalilak, Lukas T; Tucker, Russell L; Greene, Stephen A

    2015-01-01

    Volumes used in lumbosacral epidural injections for anesthesia have remained unchanged since the 1960s. The goals of this cross-sectional observational study were to characterize the three-dimensional spread of a lumbosacral epidural injection, as well as confirm that the commonly used volume of 0.2 ml/kg injected into the lumbosacral epidural space reaches the thoracolumbar (TL) junction in the majority (≥80%) of dogs. Ten clinically normal, adult, nonpregnant, mixed-breed dogs were obtained within five minutes of euthanasia and 0.2 ml/kg of radiopaque contrast medium was injected into the lumbosacral epidural space. A computed tomography scan of the TL spine was performed immediately following the injection. Migration of contrast reached the TL junction in 8 of 10 (80%) dogs. Contrast was well visualized in all epidural planes with contrast travelling predominantly in the dorsal epidural space in 7 of 10 (70%) dogs. There was no significant difference in the weight of dogs where the epidural injectate reached the TL junction and those where it did not (P = 0.16), or in the weight of dogs where the cranial-most point of the contrast column was in the dorsal versus the ventral epidural space (P = 0.32). This preliminary study supports the use of computed tomography to characterize injectate distribution in the canine thoracolumbar epidural space and provides evidence that a 0.2-ml/kg volume is likely to reache the TL junction in most dogs. Further studies are needed in live dogs to determine if variables affecting human epidural injectate doses have similar effects in the dog.

  18. Tuberculosis versus non-Hodgldn's lymphomas involving small bowel mesentery: Evaluation with contrast-enhanced computed tomography

    Institute of Scientific and Technical Information of China (English)

    Peng Dong; Bin Wang; Quan-Ye Sun; Hui Cui

    2008-01-01

    AIM: To evaluate the specific computed tomography (CT) imaging criteria for differentiating tuberculosis involving the small bowel mesenteric lymph nodes from lymphomas.METHODS: We retrospectively reviewed the anatomic distribution,CT enhancement patterns of lymphoma in 18 patients with mesenteric tuberculosis and 22 with untreated non-Hodgkin's lymphomas (NHL) involving small bowel mesentery (SBM).Of the 18 patients with tuberculosis,9 had purely mesenteric tuberculous lymphadenopathy (TL),and 9 had mesenteric TL accompanied with tuberculous mesenteritis (TLM).RESULTS: CT showed that tuberculosis and NHL mainly affected lymph nodes in the body and root of SBM.Homogeneously enhanced lymph nodes in the body and root of SBM were found more often in the NHL (P<0.05).Homogeneously mixed peripheral enhanced lymph nodes in the body of SBM were found more often in mesenteric TL and TLM (P<0.05).Peripheral enhanced lymph nodes in the root of SBM were found more often in mesenteric TL and TLM (P<0.01)."Sandwich sign" in the root of SBM was observed more often in NHL (P<0.05).COMCLUSION: Anatomic lymph node distribution,sandwich sign and specific enhancement patterns of lymphadenopathy in SBM on CT images can be used in differentiating between tuberculosis and untreated NHL involving SBM.

  19. Detection of non-ST-elevation myocardial infarction and unstable angina in the acute setting: meta-analysis of diagnostic performance of multi-detector computed tomographic angiography

    Directory of Open Access Journals (Sweden)

    Sarno Giovanna

    2007-12-01

    Full Text Available Abstract Background Multi-detector computed tomography angiography (MDCTA has been increasingly used in the evaluation of the coronary arteries. The purpose of this study was to review the literature on the diagnostic performance of MDCTA in the acute setting, for the detection of non-ST-elevation myocardial infarction (NSTEMI and unstable angina pectoris (UAP. Methods A Pubmed and manual search of the literature published between January 2000 and June 2007 was performed. Studies were included that compared MDCTA with clinical outcome and/or CA in patients with acute chest pain, presenting at the emergency department. More specifically, studies that only included patients with initially negative cardiac enzymes suspected of having NSTEMI or UAP were included. Summary estimates of diagnostic odds ratio (DOR, sensitivity and specificity, negative (NLR and positive likelihood ratio (PLR were calculated on a patient basis. Random-effects models and summary receiver operating curve (SROC analysis were used to assess the diagnostic performance of MDCTA with 4 detectors or more. The proportion of non assessable scans (NAP on MDCTA was also evaluated. In addition, the influence of study characteristics of each study on diagnostic performance and NAP was investigated with multivariable logistic regression. Results Nine studies totalling 566 patients, were included in the meta-analysis: one randomised trial and eight prospective cohort studies. Five studies on 64-detector MDCTA and 4 studies on MDCTA with less than 64 detectors were included (32 detectors n = 1, 16 detectors n = 2, 16 and 4 detectors n = 1. Pooled DOR was 131.81 (95%CI, 50.90–341.31. The pooled sensitivity and specificity were 0.95 (95%CI, 0.90–0.98 and 0.90 (95%CI, 0.87–0.93. The pooled NLR and PLR were 0.12 (95%CI, 0.06–0.21 and 8,60 (95%CI, 5.03–14,69. The results of the logistic regressions showed that none of the investigated variables had influence on the diagnostic

  20. Three-dimensional visualisation of the internal anatomy of the sparrowhawk (Accipiter nisus) forelimb using contrast-enhanced micro-computed tomography.

    Science.gov (United States)

    Bribiesca-Contreras, Fernanda; Sellers, William I

    2017-01-01

    Gross dissection is a widespread method for studying animal anatomy, despite being highly destructive and time-consuming. X-ray computed tomography (CT) has been shown to be a non-destructive alternative for studying anatomical structures. However, in the past it has been limited to only being able to visualise mineralised tissues. In recent years, morphologists have started to use traditional X-ray contrast agents to allow the visualisation of soft tissue elements in the CT context. The aim of this project is to assess the ability of contrast-enhanced micro-CT (μCT) to construct a three-dimensional (3D) model of the musculoskeletal system of the bird wing and to quantify muscle geometry and any systematic changes due to shrinkage. We expect that this reconstruction can be used as an anatomical guide to the sparrowhawk wing musculature and form the basis of further biomechanical analysis of flight. A 3% iodine-buffered formalin solution with a 25-day staining period was used to visualise the wing myology of the sparrowhawk (Accipiter nisus). μCT scans of the wing were taken over the staining period until full penetration of the forelimb musculature by iodine was reached. A 3D model was reconstructed by manually segmenting out the individual elements of the avian wing using 3D visualisation software. Different patterns of contrast were observed over the duration of the staining treatment with the best results occurring after 25 days of staining. Staining made it possible to visualise and identify different elements of the soft tissue of the wing. Finally, a 3D reconstruction of the musculoskeletal system of the sparrowhawk wing is presented and numerical data of muscle geometry is compared to values obtained by dissection. Contrast-enhanced μCT allows the visualisation and identification of the wing myology of birds, including the smaller muscles in the hand, and provides a non-destructive way for quantifying muscle volume with an accuracy of 96.2%. By combining

  1. Three-dimensional visualisation of the internal anatomy of the sparrowhawk (Accipiter nisus forelimb using contrast-enhanced micro-computed tomography

    Directory of Open Access Journals (Sweden)

    Fernanda Bribiesca-Contreras

    2017-03-01

    Full Text Available Background Gross dissection is a widespread method for studying animal anatomy, despite being highly destructive and time-consuming. X-ray computed tomography (CT has been shown to be a non-destructive alternative for studying anatomical structures. However, in the past it has been limited to only being able to visualise mineralised tissues. In recent years, morphologists have started to use traditional X-ray contrast agents to allow the visualisation of soft tissue elements in the CT context. The aim of this project is to assess the ability of contrast-enhanced micro-CT (μCT to construct a three-dimensional (3D model of the musculoskeletal system of the bird wing and to quantify muscle geometry and any systematic changes due to shrinkage. We expect that this reconstruction can be used as an anatomical guide to the sparrowhawk wing musculature and form the basis of further biomechanical analysis of flight. Methods A 3% iodine-buffered formalin solution with a 25-day staining period was used to visualise the wing myology of the sparrowhawk (Accipiter nisus. μCT scans of the wing were taken over the staining period until full penetration of the forelimb musculature by iodine was reached. A 3D model was reconstructed by manually segmenting out the individual elements of the avian wing using 3D visualisation software. Results Different patterns of contrast were observed over the duration of the staining treatment with the best results occurring after 25 days of staining. Staining made it possible to visualise and identify different elements of the soft tissue of the wing. Finally, a 3D reconstruction of the musculoskeletal system of the sparrowhawk wing is presented and numerical data of muscle geometry is compared to values obtained by dissection. Discussion Contrast-enhanced μCT allows the visualisation and identification of the wing myology of birds, including the smaller muscles in the hand, and provides a non-destructive way for quantifying

  2. Preoperative planning of renal transplantation: a comparison of non-contrast-enhanced ultrasonography, computed tomography, and magnetic resonance angiography with observations from surgery.

    Science.gov (United States)

    Blankholm, Anne Dorte; Pedersen, Bodil G; Stausbøl-Grøn, Brian; Andersen, Gratien; Hørlyck, Arne; Østrat, Ernst Ø; Laustsen, Sussie; Ringgaard, Steffen

    2015-12-01

    Many candidates for kidney transplantation need to undergo vessel examination before the transplantation procedure. To identify the optimal preoperative modality for the examination of vessel status without the use of contrast agents in kidney transplant candidates. Fifty-three consecutive patients were examined and 31 patients were transplanted. Ultrasonography (US), non-contrast-enhanced computed tomography (NCCT), and non-contrast-enhanced magnetic resonance angiography (NCMRA) were compared using inspection during kidney transplantation (TX) as a reference standard. The sensitivity and specificity to severe arteriosclerotic changes and the accuracy were calculated. Kappa statistics were used to assess the agreement between TX and the different examination modalities, and McNemar's test was used to test for significant differences. US had higher sensitivity (1.0) and better agreement with observations from surgery (k = 0.89) than both NCCT (sensitivity = 0.60; k = 0.72) and NCMRA (sensitivity = 0.20; k = 0.30). No significant difference was found between TX and US (P = 0.3173) or TX and NCCT (P = 0.1573), but there was a significant difference between TX and NCMRA (P = 0.0455). US was inconclusive in 20% of cases, and the internal iliac artery could not be visualized in 69% of cases. Either US or NCCT can be used as the preferred preoperative imaging modality to examine vessel status before kidney transplantation, but a combination of the two is preferable. NCMRA should not be used as the sole imaging modality for preoperative imaging before kidney transplantation because of its low sensitivity in detecting severe arteriosclerotic disease without the presence of stenosis. © The Foundation Acta Radiologica 2014.

  3. Computer-aided diagnosis for classification of focal liver lesions on contrast-enhanced ultrasonography: feature extraction and characterization of vascularity patterns

    Science.gov (United States)

    Shiraishi, Junji; Sugimoto, Katsutoshi; Kamiyama, Naohisa; Moriyasu, Fuminori; Doi, Kunio

    2008-03-01

    We have developed a computer-aided diagnostic (CAD) scheme for classifying focal liver lesions (FLLs) into hepatocellular carcinoma (HCC), liver metastasis, and hemangioma, by use of B-mode and micro flow imaging (MFI) of contrast-enhanced ultrasonography. We used 98 cases in this study, in which 104 FLLs consisted of 68 HCCs, 21 metastases, and 15 hemangiomas. MFI was obtained with contrast-enhanced low-mechanical-index (MI) pulse subtraction imaging at a fixed plane which included a distinctive cross section of the FLL. In the MFI, the inflow high signals in the plane, which were due to the vascular patterns and the contrast agent, were accumulated following flash scanning with a high-MI ultrasound exposure. In this study, in addition to the existing 29 image features extracted from MFI images, such as replenishment time, the average and the standard deviation of pixel values in a FLL, and the average thickness of vessel-like patterns, four types of image features were extracted from MFI, temporal subtraction and B-mode images based on small square regions of interest (ROIs: 4x4 matrix size) placed to cover a whole region of the FLL. The four features were 1) uniformity of average pixel values for all ROIs, 2) peak pixel values in a histogram of average pixel values of ROIs, 3) fraction of hypoechoic regions within an FLL, and 4) cross-correlation of pixel values within an FLL between B-mode and MFI images. Overall classification accuracies performed by this CAD scheme were 87.5% for all 104 liver lesions.

  4. Acute gastrointestinal bleeding: detection of source and etiology with multi-detector-row CT

    Energy Technology Data Exchange (ETDEWEB)

    Scheffel, Hans; Pfammatter, Thomas; Marincek, Borut; Alkadhi, Hatem [University Hospital Zurich, Institute of Diagnostic Radiology, Zurich (Switzerland); Wildi, Stefan [University Hospital Zurich, Department of Visceral and Transplant Surgery, Zurich (Switzerland); Bauerfeind, Peter [University Hospital Zurich, Division of Gastroenterology, Zurich (Switzerland)

    2007-06-15

    This study was conducted to determine the ability of multi-detector-row computed tomography (CT) to identify the source and etiology of acute gastrointestinal bleeding. Eighteen patients with acute upper (n = 10) and lower (n = 8) gastrointestinal bleeding underwent 4-detector-row CT (n = 6), 16-detector-row CT (n = 11), and 64-slice CT (n = 1) with an arterial and portal venous phase of contrast enhancement. Unenhanced scans were performed in nine patients. CT scans were reviewed to determine conspicuity of bleeding source, underlying etiology, and for potential causes of false-negative prospective interpretations. Bleeding sources were prospectively identified with CT in 15 (83%) patients, and three (17%) bleeding sources were visualized in retrospect, allowing the characterization of all sources of bleeding with CT. Contrast extravasation was demonstrated with CT in all 11 patients with severe bleeding, but only in 1 of 7 patients with mild bleeding. The etiology could not be identified on unenhanced CT scans in any patient, whereas arterial-phase and portal venous-phase CT depicted etiology in 15 (83%) patients. Underlying etiology was correctly identified in all eight patients with mild GI bleeding. Multi-detector-row CT enables the identification of bleeding source and precise etiology in patients with acute gastrointestinal bleeding. (orig.)

  5. Acute gastrointestinal bleeding: detection of source and etiology with multi-detector-row CT.

    Science.gov (United States)

    Scheffel, Hans; Pfammatter, Thomas; Wildi, Stefan; Bauerfeind, Peter; Marincek, Borut; Alkadhi, Hatem

    2007-06-01

    This study was conducted to determine the ability of multi-detector-row computed tomography (CT) to identify the source and etiology of acute gastrointestinal bleeding. Eighteen patients with acute upper (n = 10) and lower (n = 8) gastrointestinal bleeding underwent 4-detector-row CT (n = 6), 16-detector-row CT (n = 11), and 64-slice CT (n = 1) with an arterial and portal venous phase of contrast enhancement. Unenhanced scans were performed in nine patients. CT scans were reviewed to determine conspicuity of bleeding source, underlying etiology, and for potential causes of false-negative prospective interpretations. Bleeding sources were prospectively identified with CT in 15 (83%) patients, and three (17%) bleeding sources were visualized in retrospect, allowing the characterization of all sources of bleeding with CT. Contrast extravasation was demonstrated with CT in all 11 patients with severe bleeding, but only in 1 of 7 patients with mild bleeding. The etiology could not be identified on unenhanced CT scans in any patient, whereas arterial-phase and portal venous-phase CT depicted etiology in 15 (83%) patients. Underlying etiology was correctly identified in all eight patients with mild GI bleeding. Multi-detector-row CT enables the identification of bleeding source and precise etiology in patients with acute gastrointestinal bleeding.

  6. Digital dissection - using contrast-enhanced computed tomography scanning to elucidate hard- and soft-tissue anatomy in the Common Buzzard Buteo buteo.

    Science.gov (United States)

    Lautenschlager, Stephan; Bright, Jen A; Rayfield, Emily J

    2014-04-01

    Gross dissection has a long history as a tool for the study of human or animal soft- and hard-tissue anatomy. However, apart from being a time-consuming and invasive method, dissection is often unsuitable for very small specimens and often cannot capture spatial relationships of the individual soft-tissue structures. The handful of comprehensive studies on avian anatomy using traditional dissection techniques focus nearly exclusively on domestic birds, whereas raptorial birds, and in particular their cranial soft tissues, are essentially absent from the literature. Here, we digitally dissect, identify, and document the soft-tissue anatomy of the Common Buzzard (Buteo buteo) in detail, using the new approach of contrast-enhanced computed tomography using Lugol's iodine. The architecture of different muscle systems (adductor, depressor, ocular, hyoid, neck musculature), neurovascular, and other soft-tissue structures is three-dimensionally visualised and described in unprecedented detail. The three-dimensional model is further presented as an interactive PDF to facilitate the dissemination and accessibility of anatomical data. Due to the digital nature of the data derived from the computed tomography scanning and segmentation processes, these methods hold the potential for further computational analyses beyond descriptive and illustrative proposes.

  7. CT angiography of pulmonary embolism using a 64 slice multi-detector scanner

    Institute of Scientific and Technical Information of China (English)

    QIN Nai-shan; JIANG Xue-xiang; QIU Jian-xing; ZHU Ying; WANG Ji-chen

    2009-01-01

    Background Multi-detector computed tomography (MDCT) has already been the first line investigation method for diagnosis of pulmonary embolism (PE). Reducing the amount of contrast medium used during CT scanning could decrease the incidental rate of adverse reactions. Our study amied to evaluate the image quality of pulmonary arteries using 64 slice multi-detector CT with small volumes of contrast media injection.Methods Forty nonconsecutive patients without PE or other lung diseases were randomly assigned to two groups.Group A underwent CT scanning with 16×1.25 mm collimation and a 70 ml contrast injection, while group B had CT with 64×0.625 mm collimation and 20 ml of contrast injection. Two readers independently depicted the segmental and subsegmental pulmonary arteries. Reasons we could not analyze the pulmonary artery or that led to misdiagnosis of pulmonary embolism were evaluated, including the degree of contrast enhancement of the main pulmonary artery, and factors that caused misdiagnosis of PE (flow-related artifacts, partial volume artifact, beam-hardening artifacts and enhancement of pulmonary vein). The independent samples t-test, Mann-Whitney U test and Pearson chi-square test were applied.Results There were no significant differences in image quality of segmental and subsegmental arteries between the two groups. No significant difference was found for factors that made pulmonary arteries non-analyzable or in the misdiagnosis of PE, except the degree of contrast enhancement.Conclusion 64×0.625 mm collimation with 20 ml contrast injection could depict the pulmonary arteries well.

  8. Multi-detector computed tomography radiation doses in the follow-up of paediatric neurosurgery patients in KwaZulu-Natal: A dosimetric audit

    Directory of Open Access Journals (Sweden)

    Christopher T. Sikwila

    2014-05-01

    Full Text Available Background: Multi-detector computed tomography (MDCT is the preferred modality for follow-up of paediatric neurosurgery patients. Serial imaging, however, has the disadvantage of an ionising radiation burden, which may be mitigated using the ‘as low as reasonably achievable’ (ALARA principle. Objectives: The primary objectives were to determine the radiation dose exposure in paediatric patients subjected to MDCT imaging following neurosurgery and to compare these values with references in current literature. Our secondary objective was to assess the relationship between radiation dose and clinical scenario. Method: Retrospective descriptive data were collected from all paediatric postsurgical patients (n = 169 between the ages of 0 and 12 years who had their first followed-up scan in the year 2010 and were followed up for six months or less. Dose-length product (DLP and current-time product were collected from the picture archiving and communication system. Demographic data including radiology reports were collected from the hospital information system. The effective doses (ED were calculated from the corresponding DLP using age-adjusted conversion factors. For purposes of comparison with other studies, median dosimetric values were calculated and the children were grouped into three age ranges, namely younger than 3 years, 3–7 years and 8–12 years old. Results: The highest median radiation doses were noted in patients being followed-up for intracranial abscesses (1183 mGy cm in the 8–12 year age group, most of whom were female. The lowest radiation doses were for intracranial shunt follow-ups (447 mGy cm. Median values for DLP, ED and current-time product (mAs were comparable to reference doses in all three age groups. However, our study showed a much broader distribution of values with higher upper limits relative to reference values. Indications for follow-up included shunts (n = 110; 65%, intracranial abscess (n = 31; 18%, subdural

  9. Dual-phase contrast-enhancement multislice computed tomography imaging for the assessment of elderly patients with acute myocardial infarction after primary percutaneous coronary intervention

    Institute of Scientific and Technical Information of China (English)

    Shaofeng Guan; Weiyi Fang; Xinkai Qu; Jianding Ye; Yan Shen; Jing Jiao

    2009-01-01

    Background Evaluation of acute myocardial infarction after reperfusion by dual phase contrast-enhancement multislice computed tomography (MSCT) was implicated in porcine model. There have been few attempts to use this diagnostic modality for the early assessment of coronary reperfusion in patients with ST-elevation myocardial infarction (STEMI), especially after primary percutaneous coronary intervention (PCI). In elderly patients with STEMI, the safety issues remain unknown. Methods Dual phase contrast-enhancement MSCT examinations were performed in 11 elderly patients (≥60 years old) with STEMI within one week after primary PCI. The presence, location and enhancement pattern on MSCT were evaluated. MSCT findings were compared with the catheter angiographic results and area under the curve of creatine kinase (CK) release. Serum creatinine level was recorded before and after MSCT scan. Results MSCT scans were successfully performed in all the patients. Early myocardial perfusion defect (early defect, ED) was detected in all of the 11 patients (100%) in the early phase of the contrast bolus (subendocardial ED in 10 patients and transmural in 1 patient). Mean CT attenuation value of ED was significantly different from CT attenuation value of remote myocardium (46±17 HU vs 104 ± 17 HU; P < 0.01). Location of ED area correlated well with infarction related artery territory on catheter angiography in all of the 11 patients (100%). On delayed phase of MSCT scan, different enhancement patterns were observed: isolated subendocardial late enhancement (LE) in 6 patients, subendocardial residual perfusion defect (RD) and subepicardial LE in 1 patient, subendocardial RD in 4 patients. Infarct volume assessed by MSCT correlated well with area under the curve CK release (R=0.72, P < 0.01). Serum creatinine level after MSCT scan showed no difference with that before MSCT scan. Conclusion Dual phase MSCT could be safely implicated in elderly patients with STEMI. Variable

  10. The role of contrast enhanced computed tomography in the diagnosis of necrotizing fasciitis and comparison with the laboratory risk indicator for necrotizing fasciitis (LRINEC).

    Science.gov (United States)

    Carbonetti, Francesco; Cremona, Antonio; Carusi, Valentina; Guidi, Marco; Iannicelli, Elsa; Di Girolamo, Marco; Sergi, Daniela; Clarioni, Alvise; Baio, Giulio; Antonelli, Giulio; Fratini, Luca; David, Vincenzo

    2016-02-01

    To evaluate the diagnostic efficacy of contrast enhanced computed tomography (CECT) in emergency departments for diagnosis of necrotizing fasciitis (NF) and for differential diagnosis of other musculoskeletal infections; to correlate radiological findings with the laboratory risk indicator for necrotizing fasciitis (LRINEC). 7 radiological parameters to be analysed on CECT scans were established, exams of 36 patients with proven diagnosis of NF (n 12) and other musculoskeletal infections (n 24) were retrospectively reviewed; LRINEC score was calculated. Fisher's test and Spearman's and Kendall's coefficients of rank correlations were performed. Two parameters were found to be strongly associated with the diagnosis of NF: involvement of the fascia (Spearman's ρ of 0.888, p 5) also in other musculoskeletal infections. Final diagnosis of necrosis among the fascia is surgical. Presence of gas is not a specific sign of necrotizing fasciitis being present in other musculoskeletal infections. CT could easily discriminate NF from other musculoskeletal infections, adds an important value to clinical and laboratory tests in diagnosis of NF in an emergency context when magnetic resonance imaging, which is superior to CT in this discernment, could not be performed.

  11. Contrast-enhanced computed tomography angiography and volume-rendered imaging for evaluation of cellophane banding in a dog with extrahepatic portosystemic shunt

    Directory of Open Access Journals (Sweden)

    H. Yoon

    2011-04-01

    Full Text Available A 4-year-old, 1.8 kg, male, castrated Maltese was presented for evaluation of urolithiasis. Urinary calculi were composed of ammonium biurate. Preprandial and postprandial bile acids were 44.2 and 187.3 μmol/ , respectively (reference ranges 0–10 and 0–20 μmol/ , respectively. Single-phase contrast-enhanced computed tomography angiography (CTA with volume-rendered imaging (VRI was obtained. VRI revealed a portocaval shunt originating just cranial to a tributary of the gastroduodenal vein and draining into the caudal vena cava at the level of the epiploic foramen. CTA revealed a 3.66 mm-diameter shunt measured at the level of the termination of the shunt and a 3.79 mm-diameter portal vein measured at the level between the origin of the shunt and the porta of the liver. Surgery was performed using cellophane banding without attenuation. Follow-up single-phase CTA with VRI was obtained 10 weeks after surgery. VRI revealed no evidence of portosystemic communication on the level of a cellophane band and caudal to the cellophane band. CTA demonstrated an increased portal vein diameter (3.79–5.27 mm measured at the level between the origin of the shunt and the porta of the liver. Preprandial and postprandial bile acids were 25 and 12.5 μmol/ , respectively (aforementioned respective reference ranges, 3 months post-surgery. No problems were evident at 6 months.

  12. The Effectiveness of Non-ECG-Gated Contrast-Enhanced Computed Tomography for the Diagnosis of Non-ST Segment Elevation Acute Coronary Syndrome.

    Science.gov (United States)

    Watanabe, Tomomi; Furuse, Yoshiyuki; Ohta, Yasutoshi; Kato, Masahiko; Ogawa, Toshihide; Yamamoto, Kazuhiro

    2016-09-28

    Non-ST segment elevation acute coronary syndrome (NSTE-ACS) can be difficult to diagnose accurately, especially in the hyper-acute phase. Non-ECG-gated contrast-enhanced computed tomography (non-ECG-gated CE-CT) has been used in many institutions for screening acute chest pain. Although early defects (EDs) observed in non-ECG-gated CE-CT have been reported as a sign of acute myocardial ischemia, the precise diagnostic value of this sign for acute coronary syndrome has not been fully elucidated. We investigated the usefulness of non-ECG-gated CE-CT for the diagnosis of NSTE-ACS. We retrospectively reviewed 556 patients who were hospitalized for acute-onset chest pain and who underwent emergent coronary angiography. Non-ECG-gated CE-CT was performed in 23 of these patients. Two readers independently analyzed CT images using a 5-point scale. Of the 23 patients, 13 were diagnosed with NSTE-ACS. The remaining 10 patients were diagnosed with other conditions. The sensitivity, specificity, positive predictive value, and negative predictive value, respectively, of EDs on non-ECG-gated CE-CT to detect NSTE-ACS were 84.6%, 90%, 91.7%, and 81.8%. The identification of EDs was consistent between the two readers. Non-ECG-gated CE-CT may be useful not only to triage patients with chest pain by ruling out other conditions, but also to accurately diagnose NSTE-ACS.

  13. Use of cystatin C and serum creatinine for the diagnosis of contrast-induced nephropathy in patients undergoing contrast-enhanced computed tomography at an oncology centre.

    Directory of Open Access Journals (Sweden)

    Joao Italo Fortalesa Melo

    Full Text Available Our aim was to assess renal function using as laboratory measurements serum creatinine and cystatin C concentrations before and after administration of low-osmolarity (nonionic iodinated contrast medium in patients with cancer undergoing computed tomography (CT.This prospective study included 400 oncologic outpatients. Serum creatinine and cystatin C concentrations were measured before and 72 h after contrast administration. Glomerular filtration rates (GFRs were estimated using serum creatinine-based [Modification of Diet in Renal Disease (MDRD and Cockroft-Gault and cystatin C based (Larsson equations. Exploratory data analysis was performed. The nonparametric Wilcoxon test was used to compare pre and post contrast of test results and estimated clearance. The confidence interval used in the analysis was 95%.Compared with the pre-contrast values, the mean serum creatinine concentration was significantly higher and average GFRs estimated using MDRD and Cockcroft-Gault equations were significantly lower after the administration of contrast (p <0.001. It was also observed a significant increase after contrast in the concentration of Cystatin C (p = 0.015. In addition, a decrease in GFR estimated using the average Larsson (p = 0.021 was observed between time points. However, none of the patients presented clinically significant nephropathy.Assessment using serum creatinine and cystatin C concentrations showed changes in renal function among patients with cancer undergoing contrast-enhanced CT examination in this study. No significant renal damage related to the use of low-osmolarity iodinated contrast medium of the type and dosage employed in this study was observed. This contrast medium is thus safe for use in patients with cancer.

  14. Contrast-induced enphropathy in patients undergoing intravenous contrast-enhanced computed tomography in Korea; A multi-institutional study in 101487 patients

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Joong Yub [Medical Research Collaborating Center, Seoul National University Hospital, Seoul National University College of Medicine, Seoul (Korea, Republic of); Cho, Jeong Yeon [Dept. of Radiology, Seoul National University College of Medicine, Seoul (Korea, Republic of); Jeong, Yong Yeon [Dept. of Radiology, Chonnam National University Hwasun Hospital, Chonnam National University Medical School, Hwasun (Korea, Republic of); and others

    2014-08-15

    To evaluate the prevalence of known risk factors for contrast-induced nephropathy (CIN) and their association with the actual occurrence of CIN in patients undergoing intravenous contrast-enhanced computed tomography (CECT) in Korea. Patients who underwent CECT in 2008 were identified in the electronic medical records of 16 tertiary hospitals of Korea. Data on demographics, comorbidities, prescriptions and laboratory test results of patients were collected following a standard data extraction protocol. The baseline renal function was assessed using the estimated glomerular filtration rate (eGFR). We identified the prevalence of risk factors along the eGFR strata and evaluated their influence on the incidence of CIN, defined as a 0.5 mg/dL or 25% increase in serum creatinine after CECT. Of 432425 CECT examinations in 272136 patients, 140838 examinations in 101487 patients met the eligibility criteria for analysis. The mean age of the participants was 57.9 ± 15.5 years; 25.1% of the patients were older than 70 years. The prevalence of diabetes mellitus was 11.9%, of hypertension 13.7%, of gout 0.55% and of heart failure was 1.7%. Preventive measures were used in 40238 CECT examinations (28.6%). The prevalence of risk factors and use of preventive measures increased as the renal function became worse. A CIN was occurred after 3103 (2.2%) CECT examinations, revealing a significant association with decreased eGFR, diabetes mellitus, and congestive heart failure after adjustment. Risk factors for CIN are prevalent among the patients undergoing CECT. Preventive measures were seemingly underutilized and a system is needed to improve preventive care.

  15. An innovative technique for contrast enhancement of computed tomography images using normalized gamma-corrected contrast-limited adaptive histogram equalization

    Science.gov (United States)

    Al-Ameen, Zohair; Sulong, Ghazali; Rehman, Amjad; Al-Dhelaan, Abdullah; Saba, Tanzila; Al-Rodhaan, Mznah

    2015-12-01

    Image contrast is an essential visual feature that determines whether an image is of good quality. In computed tomography (CT), captured images tend to be low contrast, which is a prevalent artifact that reduces the image quality and hampers the process of extracting its useful information. A common tactic to process such artifact is by using histogram-based techniques. However, although these techniques may improve the contrast for different grayscale imaging applications, the results are mostly unacceptable for CT images due to the presentation of various faults, noise amplification, excess brightness, and imperfect contrast. Therefore, an ameliorated version of the contrast-limited adaptive histogram equalization (CLAHE) is introduced in this article to provide a good brightness with decent contrast for CT images. The novel modification to the aforesaid technique is done by adding an initial phase of a normalized gamma correction function that helps in adjusting the gamma of the processed image to avoid the common errors of the basic CLAHE of the excess brightness and imperfect contrast it produces. The newly developed technique is tested with synthetic and real-degraded low-contrast CT images, in which it highly contributed in producing better quality results. Moreover, a low intricacy technique for contrast enhancement is proposed, and its performance is also exhibited against various versions of histogram-based enhancement technique using three advanced image quality assessment metrics of Universal Image Quality Index (UIQI), Structural Similarity Index (SSIM), and Feature Similarity Index (FSIM). Finally, the proposed technique provided acceptable results with no visible artifacts and outperformed all the comparable techniques.

  16. Use of Cystatin C and Serum Creatinine for the Diagnosis of Contrast-Induced Nephropathy in Patients Undergoing Contrast-Enhanced Computed Tomography at an Oncology Centre

    Science.gov (United States)

    Fortalesa Melo, Joao Italo; Chojniak, Rubens; Costa Silva, Debora Helena; Oliveira Junior, Jose Carlos; Vieira Bitencourt, Almir Galvão; Holanda Silva, Diego; Guimarães, Marcos Duarte; Silva, Hernandes Cerqueira Souza; Dias, Denis Guilherme Teixeira; Rodrigues, Winglison Carli; Brancucci, Ellen Luzia; Cruz, Barbara Martins Soares; Schiavon, Beatriz Nunes; Argenton, Juliana Luz Passos; Camporini, Margareth Arrivabene; Zocchio, Adriana

    2015-01-01

    Objective Our aim was to assess renal function using as laboratory measurements serum creatinine and cystatin C concentrations before and after administration of low-osmolarity (nonionic) iodinated contrast medium in patients with cancer undergoing computed tomography (CT). Methods This prospective study included 400 oncologic outpatients. Serum creatinine and cystatin C concentrations were measured before and 72 h after contrast administration. Glomerular filtration rates (GFRs) were estimated using serum creatinine–based [Modification of Diet in Renal Disease (MDRD) and Cockroft-Gault and cystatin C based (Larsson) equations. Exploratory data analysis was performed. The nonparametric Wilcoxon test was used to compare pre and post contrast of test results and estimated clearance. The confidence interval used in the analysis was 95%. Results Compared with the pre-contrast values, the mean serum creatinine concentration was significantly higher and average GFRs estimated using MDRD and Cockcroft-Gault equations were significantly lower after the administration of contrast (p <0.001). It was also observed a significant increase after contrast in the concentration of Cystatin C (p = 0.015). In addition, a decrease in GFR estimated using the average Larsson (p = 0.021) was observed between time points. However, none of the patients presented clinically significant nephropathy. Conclusions Assessment using serum creatinine and cystatin C concentrations showed changes in renal function among patients with cancer undergoing contrast-enhanced CT examination in this study. No significant renal damage related to the use of low-osmolarity iodinated contrast medium of the type and dosage employed in this study was observed. This contrast medium is thus safe for use in patients with cancer. PMID:25961558

  17. Contrast-enhanced endoscopic ultrasonography

    DEFF Research Database (Denmark)

    Reddy, Nischita K; Ioncica, Ana Maria; Saftoiu, Adrian;

    2011-01-01

    agents and their use in various endoscopic procedures in the gastrointestinal tract. Various applications of contrast-enhanced endoscopic ultrasonography include differentiating benign from malignant mediastinal lymphadenopathy, assessment of depth of invasion of esophageal, gastric and gall bladder...... sonography to depict tumor neovascularization can be increased by contrast agents. Contrast-enhanced harmonic imaging is a useful aid in identifying the tumor vasculature and studying pancreatic microperfusion. In the future, these techniques could potentially be used to quantify tumor perfusion, to assess...

  18. Fuzzy-Contextual Contrast Enhancement.

    Science.gov (United States)

    Parihar, Anil; Verma, Om; Khanna, Chintan

    2017-02-08

    This paper presents contrast enhancement algorithms based on fuzzy contextual information of the images. We introduce fuzzy similarity index and fuzzy contrast factor to capture the neighborhood characteristics of a pixel. A new histogram, using fuzzy contrast factor of each pixel is developed, and termed as the fuzzy dissimilarity histogram (FDH). A cumulative distribution function (CDF) is formed with normalized values of FDH and used as a transfer function to obtain the contrast enhanced image. The algorithm gives good contrast enhancement and preserves the natural characteristic of the image. In order to develop a contextual intensity transfer function, we introduce a fuzzy membership function based on fuzzy similarity index and coefficient of variation of the image. The contextual intensity transfer function is designed using the fuzzy membership function to achieve final contrast enhanced image. The overall algorithm is referred as the fuzzy contextual contrast-enhancement (FCCE) algorithm. The proposed algorithms are compared with conventional and state-of-art contrast enhancement algorithms. The quantitative and visual assessment of the results is performed. The results of quantitative measures are statistically analyzed using t-test. The exhaustive experimentation and analysis show the proposed algorithm efficiently enhances contrast and yields in natural visual quality images.

  19. Fusion of intravenous contrast-enhanced C-arm CT and pretreatment imaging for ablation margin assessment of liver tumors: A preliminary study

    Directory of Open Access Journals (Sweden)

    Jin Iwazawa

    2012-01-01

    Full Text Available The aim of this preliminary study was to evaluate the feasibility of assessing ablation margins after radiofrequency ablation (RFA of liver tumors from fusion images of post-treatment C-arm computed tomography (CT images fused to pretreatment images. Five patients with liver tumors underwent RFA. Intravenous contrast-enhanced C-arm CT images were obtained for all patients immediately after RFA, and multi-detector CT (MDCT images were obtained 3-7 days later. The C-arm CT and MDCT images were fused to pretreatment images using a multimodality image fusion software. The minimum ablation margins were assessed in the C-arm CT and MDCT fusion images. Ablation margins after RFA of liver tumors can be measured using intravenous contrast-enhanced C-arm CT images fused with pretreatment images. This technique has the potential for use in the intra-procedural assessment of liver tumor ablation.

  20. The Incidence, Classification, and Management of Acute Adverse Reactions to the Low-Osmolar Iodinated Contrast Media Isovue and Ultravist in Contrast-Enhanced Computed Tomography Scanning

    Science.gov (United States)

    Zhang, Bin; Dong, Yuhao; Liang, Long; Lian, Zhouyang; Liu, Jing; Luo, Xiaoning; Chen, Wenbo; Li, Xinyu; Liang, Changhong; Zhang, Shuixing

    2016-01-01

    Abstract Some epidemiologic surveillance studies have recorded adverse drug reactions to radiocontrast agents. We aimed to investigate the incidence and management of acute adverse reactions (AARs) to Ultravist-370 and Isovue-370 in patients who underwent contrast-enhanced computed tomography (CT) scanning. Data from 137,473 patients were analyzed. They had undergone enhanced CT scanning with intravenous injection of Ultravist-370 or Isovue-370 during the period of January 1, 2006 to December 31, 2012 in our hospital. We investigated and classified AARs according to the American College of Radiology and the Chinese Society of Radiology (CSR) guidelines for iodinated contrast media. We analyzed risk factors for AARs and compared the AARs induced by Ultravist-370 and Isovue-370. Four hundred and twenty-eight (0.31%) patients experienced AARs, which included 330 (0.24%) patients with mild AARs, 82 (0.06%) patients with moderate AARs, and 16 (0.01%) patients with severe AARs (including 3 cases of cardiac arrest and one case of death). The incidence of AARs was higher with Ultravist-370 than with Isovue-370 (0.38% vs 0.24%, P < 0.001), but only for mild AARs (0.32% vs 0.16%, P < 0.001). Analyses on risk factors indicated that female patients (n = 221, 0.43%, P < 0.001), emergency patients (n = 11, 0.51%, P < 0.001), elderly patients aged 50 to 60 years (n = 135, 0.43%, P < 0.001), and patients who underwent coronary computed tomography angiography (CTA) (n = 55, 0.51%, P < 0.001) had a higher risk of AARs. Cutaneous manifestations (50.52%)—especially rash (59.74%)—were the most frequent mild AARs. Cardiovascular manifestations accounted for most moderate and severe AARs (62.91% and 48.28%, respectively). After proper management, the symptoms and signs of 96.5% of the AARs resolved within 24 hours without sequelae. Ultravist-370 and Isovue-370 are safe for patients undergoing enhanced CT scanning. The incidence of AARs is

  1. Contrast induced nephropathy in patients undergoing intravenous (IV) contrast enhanced computed tomography (CECT) and the relationship with risk factors: A meta-analysis

    Energy Technology Data Exchange (ETDEWEB)

    Moos, Shira I., E-mail: s.i.moos@amc.uva.nl; Vemde, David N.H. van; Stoker, Jaap; Bipat, Shandra

    2013-09-15

    Purpose: To summarize the incidence of contrast-induced nephropathy (CIN) and associations between CIN incidence and risk factors in patients undergoing intravenous contrast-enhanced computed tomography (CECT) with low- or iso-osmolar iodinated contrast medium. Methods: This review is performed in accordance with the preferred reporting items in systematic reviews and meta-analysis (PRISMA) guidelines. We searched the MEDLINE, EMBASE and Cochrane databases from 2002 till November 2012. Two reviewers included papers and extracted data. The pooled data were analysed by either fixed or random-effects approach depending on heterogeneity defined as the I{sup 2} index. Results: 42 articles with 18,790 patients (mean age 61.5 years (range: 38–83 years)) were included. The mean baseline eGFR was 59.8 mL/min and ranged from 4 to 256 mL/min. Of all patients 45.0% had an estimated glomerular filtration rate (eGFR) < 60 mL/min, 55.2% had hypertension; 20.2% had diabetes mellitus (DM) and 6.5% had congestive heart failure (CHF). The overall pooled CIN incidence, defined as a SCr increase of ≥25% or ≥0.5 mg/dL, was 4.96% (95%CI: 3.79–6.47). Data analysis showed associations between CIN and the presence of renal insufficiency, DM, malignancy, age > 65 years and use of non-steroidal anti-inflammatory drugs (NSAID's) with odds ratios of 1.73 (95%CI: 1.06–2.82), 1.87 (95%CI: 1.55–2.26), 1.79 (95%CI: 1.03–3.11), 1.95 (95%CI: 1.02–3.70) and 2.32 (95%CI: 1.04–5.19), respectively while hypertension, anaemia and CFH were not associated (p = 0.13, p = 0.38, p = 0.40). Conclusion: The mean incidence of CIN after intravenous iodinated CECT was low and associated with renal insufficiency, diabetes, presence of malignancy, old age and NSAID's use.

  2. The utility of multi-detector computed tomography in the diagnosis of malignant pleural effusion in the patients with ovarian cancer

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Kyung Won [Department of Radiology and Institute of Radiation Medicine, Seoul National University College of Medicine, Seoul (Korea, Republic of); Choi, Hyuck Jae, E-mail: hjchoi@ncc.re.k [Department of Radiology, Asan Medical Center, University of Ulsan, Seoul (Korea, Republic of); Kang, Sokbom; Park, Sang-Yoon; Jung, Dae Chul [Research Institute and Hospital, National Cancer Center (Korea, Republic of); Cho, Jeong Yeon [Department of Radiology and Institute of Radiation Medicine, Seoul National University College of Medicine, Seoul (Korea, Republic of); Cho, Kyung-Sik [Department of Radiology, Asan Medical Center, University of Ulsan, Seoul (Korea, Republic of); Kim, Seung Hyup [Department of Radiology and Institute of Radiation Medicine, Seoul National University College of Medicine, Seoul (Korea, Republic of)

    2010-08-15

    Purpose: The purpose of this study was to retrospectively assess possible clinical predictors of malignant pleural effusion in patients with ovarian cancer. Materials and methods: This review was performed on 38 ovarian cancer patients that showed pleural effusion in a CT scan and who underwent thoracocentesis before treatment. CT scans were obtained using a 4-channel multi-detector CT scanner. Fisher's exact test was used to determine the probability of malignant pleural effusion as a function of; amount of ascites, lymph node enlargement, amount of pleural effusion, pleural nodules, and pleural thickening. Results: Sixteen (42.1%) of the 38 patients had malignant pleural effusion and malignant pleural effusion amounts were greater than those with nonmalignant effusion. Pleural nodules were more frequently found in the malignant pleural effusion group (eight [50%] patients) than in the nonmalignant group (zero [0%] patient) (p < 0.001). Supradiaphragmatic lymph node enlargement (with short axis diameter 1 cm or more) was more frequent in malignant group (12 [75%] patients) than in the nonmalignant group (two [9.1%] patients) (p < 0.001). Conclusion: The probability of malignant pleural effusion in patients with ovarian cancer was found to be correlated with the amount of pleural effusion, the presence of pleural nodules, and supradiaphragmatic lymph node enlargement.

  3. Ascending aorta measurements as assessed by ECG-gated multi-detector computed tomography: a pilot study to establish normative values for transcatheter therapies

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Tri-Linh C.; Rizzo, Elena [University Hospital Lausanne (CHUV), Department of Radiology, Lausanne (Switzerland); Huber, Christoph H.; Segesser, Ludwig K. von [University Hospital Lausanne (CHUV), Department of Cardiovascular Surgery, Lausanne (Switzerland); Dehmeshki, Jashmid [Kingston University, Digital Imaging Research Centre, Faculty of Computing, Information Systems and Mathematics, London (United Kingdom); Qanadli, Salah D. [University Hospital Lausanne (CHUV), Department of Radiology, Lausanne (Switzerland)]|[BH-07, Centre Hospitalier Universitaire Vaudois, Service de Radiodiagnostic et de Radiologie interventionnelle, Lausanne (Switzerland)

    2009-03-15

    The aim of this study was to provide an insight into normative values of the ascending aorta in regards to novel endovascular procedures using ECG-gated multi-detector CT angiography. Seventy-seven adult patients without ascending aortic abnormalities were evaluated. Measurements at relevant levels of the aortic root and ascending aorta were obtained. Diameter variations of the ascending aorta during cardiac cycle were also considered. Mean diameters (mm) were as follows: LV outflow tract 20.3{+-}3.4, coronary sinus 34.2{+-}4.1, sino-tubular junction 29.7{+-}3.4 and mid ascending aorta 32.7{+-}3.8 with coefficients of variation (CV) ranging from 12 to 17%. Mean distances (mm) were: from the plane passing through the proximal insertions of the aortic valve cusps to the right brachio-cephalic artery (BCA) 92.6{+-}11.8, from the plane passing through the proximal insertions of the aortic valve cusps to the proximal coronary ostium 12.1{+-}3.7, and between both coronary ostia 7.2{+-}3.1, minimal arc of the ascending aorta from left coronary ostium to right BCA 52.9{+-}9.5, and the fibrous continuity between the aortic valve and the anterior leaflet of the mitral valve 14.6{+-}3.3, CV 13-43%. Mean aortic valve area was 582.0{+-}131.9 mm{sup 2}. The variation of the antero-posterior and transverse diameters of the ascending aorta during the cardiac cycle were 8.4% and 7.3%, respectively. Results showed large inter-individual variations in diameters and distances but with limited intra-individual variations during the cardiac cycle. A personalized approach for planning endovascular devices must be considered. (orig.)

  4. Contrast enhancement in light microscopy.

    Science.gov (United States)

    Ernst Keller, H; Watkins, Simon

    2013-01-01

    The optical microscope is a fundamental component of an image cytometry system. This unit covers the basic concepts of light microscopy, including Köhler illumination, resolution, contrast, and numerical aperture, and reviews the many types of instruments and techniques for contrast enhancement.

  5. Contrast-enhanced peripheral MRA

    DEFF Research Database (Denmark)

    Nielsen, Yousef W; Thomsen, Henrik S

    2012-01-01

    In the last decade contrast-enhanced magnetic resonance angiography (CE-MRA) has gained wide acceptance as a valuable tool in the diagnostic work-up of patients with peripheral arterial disease. This review presents current concepts in peripheral CE-MRA with emphasis on MRI technique and contrast...

  6. Non-invasive assessment of coronary artery bypass graft with retrospectively ECG-gated four-row multi-detector spiral computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Marano, Riccardo; Storto, Maria Luigia; Maddestra, Nicola; Bonomo, Lorenzo [Department of Clinical Sciences and Bioimaging, Section of Radiology, University ' ' G. d' Annunzio' ' , Ospedale ' ' SS. Annunziata' ' , Via dei Vestini, 66100, Chieti (Italy)

    2004-08-01

    The purpose of this study was to assess the accuracy of four-row multi-detector CT (MDCT) in the evaluation of coronary artery bypass graft (CABG) in patients with at least a left internal mammary artery (LIMA) grafted to the left anterior descending artery (LAD), because of the conduit of choice in bypass surgery and the greater difficulty of evaluation with non-invasive diagnostic tools. Included in the study were 57 patients with a total of 122 grafts (95 arterial and 27 venous) who underwent MDCT (4 x 2.5-mm detector-collimation, 3-mm slice width, 1.5-mm reconstruction increment) with retrospective ECG gating. Twelve patients (21%) with high heart rates were given beta-blockers in order to obtain a heart rate {<=}70 bpm in all patients. The ECG-synchronized axial images, reconstructed in the mid-diastole, MPR, MIP and 3D-VR images were independently and blindly assessed by two radiologists for graft patency and presence of high grade stenosis. Conventional angiography was the standard of reference. MDCT correctly classified 92/94 patent grafts and 26/28 occluded grafts (sensitivity/specificity 93%/97.8%); sensitivity and specificity of MDCT for assessment of arterial grafts were 100 and 98.7% (77/78 patent grafts and 17/17 occluded grafts). Image quality was considered adequate for assessment of significant stenoses in 62/92 (67%) patent grafts, with a significant differences between LIMA and non-LIMA conduits (44/57 vs. 18/65; P=0.002), according to the coronary vessel area supplied (anterior>lateral>posterior-inferior wall; P=0.002). In the remaining 30 patent grafts (33%), the assessment of stenoses was hampered by surgical clips, calcifications and motion artifacts. Sensitivity and specificity of MDCT for detection of significant graft stenoses were 80 and 96%, respectively. Inter-observer agreement was good (K=0.73). MDCT seems to be a valuable diagnostic tool for non-invasive assessment of patency of both venous and arterial grafts. An accurate evaluation

  7. Doses of Coronary Study in 64 Channel Multi-Detector Computed Tomography : Reduced Radiation Dose According to Varity of Examnination Protocols

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Moon Chan [Dept. of Diagnostic Radiology, Samsung Medical Center, Seoul (Korea, Republic of)

    2009-09-15

    To compare radiation dose for coronary CT angiography (CTA) obtained with 6 examination protocols such as a retrospectively ECG gated helical scan, a prospectively ECG gated sequential scan, low kVp technique, and cardiac dose modulation technique. Coronary CTA was performed by using 6 current clinical protocols to evaluate effective dose and organ dose in primary beam area with anthropomorphic female phantom and glass dosimetric system in 64 channel multi-detector CT. After acquiring topograms of frontal and lateral projection with 80 kVp and 10 mA, main coronary scan was done with 0.35 sec tube rotation time, 40 mm collimation (0.625 mm x 64 ea), small scan field of view (32 cm diameter), 105 mm scan length. Heart beat rate of phantom was maintained 60 bpm in ECG gating. In constant mAs technique 120 kVp, 600 mA was used, and 100 kVp for low kVp technique. In a retrospectively ECG gated helical CT technique 0.22 pitch was used, peak mA (600 mA) was adopted in range of 40-80% of R-R interval and 120 mA (80% reduction) in others with cardiac dose modulation. And 210 mAs was used without cardiac dose modulation. In a prospectively ECG gated sequential CT technique data were acquired at 75% R-R interval (middle diastolic phase in cardiac cycle), and 120 msec additional padding of the tube-on time was used. For effective dose calculation region specific conversion factor of dose length product in thorax was used, which was recommended by EUR 16262. The mean effective dose for conventional coronary CTA without cardiac dose modulation in a retrospectively ECG gated helical scan was 17.8 mSv, and mean organ dose of heart was 103.8 mGy. With low kVp and cardiac dose modulation the mean effective dose showed 54.5% reduction, and heart dose showed 52.3% reduction, compared with that of conventional coronary CTA. And at the sequential scan(SnapShot pulse mode) under prospective ECG gating the mean effective dose was 4.9 mSv, this represents an 72.5% reduction compared with

  8. Contrast-enhanced endoscopic ultrasonography

    Institute of Scientific and Technical Information of China (English)

    Nischita K Reddy; Ana Maria Ioncic(a); Adrian S(a)ftoiu; Peter Vilmann; Manoop S Bhutani

    2011-01-01

    Contrast agents are increasingly being used to characterize the vasculature in an organ of interest,to better delineate benign from malignant pathology and to aid in staging and directing therapeutic procedures.We review the mechanisms of action of first,second and third generation contrast agents and their use in various endoscopic procedures in the gastrointestinal tract.Various applications of contrast-enhanced endoscopic ultrasonography include differentiating benign from malignant mediastinal lymphadenopathy,assessment of depth of invasion of esophageal,gastric and gall bladder cancers and visualization of the portal venous system and esophageal varices.In addition,contrast agents can be used to differentiate pancreatic lesions.The use of color Doppler further increases the ability to diagnose and differentiate various pancreatic malignancies.The sensitivity of power Doppler sonography to depict tumor neovascularization can be increased by contrast agents.Contrast-enhanced harmonic imaging is a useful aid in identifying the tumor vasculature and studying pancreatic microperfusion.In the future,these techniques could potentially be used to quantify tumor perfusion,to assess and monitor the efficacy of antiangiogenic agents,to assist targeted drug delivery and allow molecular imaging.

  9. Dynamic contrast enhanced magnetic resonance perfusion imaging in high-risk smokers and smoking-related COPD: correlations with pulmonary function tests and quantitative computed tomography.

    Science.gov (United States)

    Xia, Yi; Guan, Yu; Fan, Li; Liu, Shi-Yuan; Yu, Hong; Zhao, Li-Ming; Li, Bing

    2014-09-01

    The study aimed to prospectively evaluate correlations between dynamic contrast-enhanced (DCE) MR perfusion imaging, pulmonary function tests (PFT) and volume quantitative CT in smokers with or without chronic obstructive pulmonary disease (COPD) and to determine the value of DCE-MR perfusion imaging and CT volumetric imaging on the assessment of smokers. According to the ATS/ERS guidelines, 51 male smokers were categorized into five groups: At risk for COPD (n = 8), mild COPD (n = 9), moderate COPD (n = 12), severe COPD (n = 10), and very severe COPD (n = 12). Maximum slope of increase (MSI), positive enhancement integral (PEI), etc. were obtained from MR perfusion data. The signal intensity ratio (RSI) of the PDs and normal lung was calculated (RSI = SIPD/SInormal). Total lung volume (TLV), total emphysema volume (TEV) and emphysema index (EI) were obtained from volumetric CT data. For "at risk for COPD," the positive rate of PDs on MR perfusion images was higher than that of abnormal changes on non-enhanced CT images (p < 0.05). Moderate-to-strong positive correlations were found between all the PFT parameters and SIPD, or RSI (r range 0.445∼0.683, p ≤ 0.001). TEV and EI were negatively correlated better with FEV1/FVC than other PFT parameters (r range -0.48 --0.63, p < 0.001). There were significant differences in RSI and SIPD between "at risk for COPD" and "very severe COPD," and between "mild COPD" and "very severe COPD". Thus, MR perfusion imaging may be a good approach to identify early evidence of COPD and may have potential to assist in classification of COPD.

  10. Evaluation of the nephrotoxicity of iodixanol in patients with predisposing factors to contrast medium induced nephropathy referred for contrast enhanced computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Sandstede, Joern J.W. [Department of Radiology, University of Wuerzburg, Josef-Schneider-Strasse 2, D-97080 Wuerzburg (Germany) and Roentgenzentrum Hamburg, Schaeferkampsallee 5-7, D-20357 Hamburg (Germany)]. E-mail: sandstede@web.de; Roth, Anne [Department of Radiology, University of Wuerzburg, Josef-Schneider-Strasse 2, D-97080 Wuerzburg (Germany); Machann, Wolfram [Department of Radiology, University of Wuerzburg, Josef-Schneider-Strasse 2, D-97080 Wuerzburg (Germany); Kaupert, Christine [Department of Radiology, University of Wuerzburg, Josef-Schneider-Strasse 2, D-97080 Wuerzburg (Germany); Hahn, Dietbert [Department of Radiology, University of Wuerzburg, Josef-Schneider-Strasse 2, D-97080 Wuerzburg (Germany)

    2007-07-15

    To determine the risk of developing contrast induced nephropathy (CIN) in intermediate-risk patients receiving iodixanol, an iso-osmolar, dimeric non-ionic contrast agent, for CT in a clinical setting. Hundred consecutive patients referred for a contrast enhanced CT with a serum creatinine concentration > 1.1 mg/dl and/or a glomerular filtration rate (GFR) < 90 ml/min were included. Exclusion criteria were a serum creatinine > 2.0 mg/dl and a GFR < 30 ml/min or concurrent nephrotoxic agents. Between 60 and 140 ml (mean 97 {+-} 42 ml) iodixanol (320 mgI/ml) were administered at a flow of 2.5-3 ml/s. Hydration with 500 ml NaCl i.v. was performed before and after contrast injection. Follow-up was completed in 99 patients (age, 64 {+-} 13 years, 68 men). CIN was defined as increase in serum creatinine concentration +0.5 mg/dl or >25% above baseline within 72 h after contrast administration. Serum creatinine concentration and GFR were 1.40 {+-} 0.22, 1.29 {+-} 0.29, and 1.26 {+-} 0.29 mg/dl and 52.2 {+-} 13.9, 51.3 {+-} 21.1, and 51.5 {+-} 15.1 ml/min on days 0, 3, and 7, respectively. Three out of 99 (3%) patients who received 90-110 ml iodixanol revealed a CIN on day 3 without persistence on day 7. No specific therapy was needed. One out of 99 patients reported an exanthema on days 3 and 7. With the use of iodixanol in intermediate-risk patients, 3% of the patients develop CIN on day 3 without need for a specific therapy or persistence on day 7.

  11. A STUDY ON DIAGNOSTIC ACCURACY OF BIOCHEMICAL MARKERS AND TRANS–ABDOMINAL ULTRASONOGRAPHY IN COMPARISON TO MULTI-DETECTOR COMPUTED TOMOGRAPHY IN DETECTION OF ACUTE PANCREATITIS

    Directory of Open Access Journals (Sweden)

    Biplab Debbarma

    2016-07-01

    Full Text Available Acute pancreatitis is an acute, mainly diffuse, inflammatory process of the pancreas. Computed Tomography (CT scan is the modality of choice for diagnosis of acute pancreatitis. But non-availability of Computed Tomography (CT scan in all health facilities made detection of acute pancreatitis is problemsome. OBJECTIVES 1. To assess the diagnostic accuracy of Biochemical Markers and Trans-Abdominal Ultrasonography in comparison to Multidetector Computed Tomography in diagnosis of acute pancreatitis. 2. To compare the findings of Trans-Abdominal Ultrasonography with Multidetector Computed Tomography. MATERIALS AND METHODS 100 clinically suspected for acute pancreatitis patients were tested for abnormal biochemical markers, followed by examined by USG and then by MDCT in Radiodiagnosis Department of AGMC and GBP Hospital and findings were compared. Sensitivity, specificity, positive predictive value and negative predictive value were calculated. RESULTS The sensitivity and specificity of trans-abdominal ultrasonography was calculated as 75% (CI 64.06% - 84.01% and 100% (CI 83.16%-100%. CONCLUSION USG had similar sensitivity, but higher specificity value than serum markers (Amylase and Lipase.

  12. High concentration (400 mgI/mL) versus low concentration (320 mgI/mL) iodinated contrast media in multi detector computed tomography of the liver: A randomized, single centre, non-inferiority study

    Energy Technology Data Exchange (ETDEWEB)

    Rengo, Marco, E-mail: marco.rengo@gmail.com [Department of Radiological Sciences, Oncology and Pathology, University of Rome ' SAPIENZA' , Polo Pontino, I.C.O.T., Via Franco Faggiana 34, 04100 Latina (Italy); Caruso, Damiano, E-mail: dcaruso85@gmail.com [Department of Radiological Sciences, Oncology and Pathology, University of Rome ' SAPIENZA' , Polo Pontino, I.C.O.T., Via Franco Faggiana 34, 04100 Latina (Italy); De Cecco, Carlo N., E-mail: carlodececco@gmail.com [Department of Radiological Sciences, Oncology and Pathology, University of Rome ' SAPIENZA' , Polo Pontino, I.C.O.T., Via Franco Faggiana 34, 04100 Latina (Italy); Lucchesi, Paola, E-mail: paola.lucchesi@email.it [Department of Radiological Sciences, Oncology and Pathology, University of Rome ' SAPIENZA' , Polo Pontino, I.C.O.T., Via Franco Faggiana 34, 04100 Latina (Italy); Bellini, Davide, E-mail: bellinidavide29@gmail.com [Department of Radiological Sciences, Oncology and Pathology, University of Rome ' SAPIENZA' , Polo Pontino, I.C.O.T., Via Franco Faggiana 34, 04100 Latina (Italy); Maceroni, Marco Maria, E-mail: marcom.maceroni@gmail.com [Department of Radiological Sciences, Oncology and Pathology, University of Rome ' SAPIENZA' , Polo Pontino, I.C.O.T., Via Franco Faggiana 34, 04100 Latina (Italy); Ferrari, Riccardo, E-mail: ferraririccardo@gmail.com [Department of Radiological Sciences, San Giovanni Hospital, Via dell' Amba Aradam 9, 00184 Rome (Italy); Paolantonio, Pasquale, E-mail: paolantoniopasquale@hotmail.com [Department of Radiological Sciences, San Giovanni Hospital, Via dell' Amba Aradam 9, 00184 Rome (Italy); and others

    2012-11-15

    Objectives: To compare vascular and parenchymal contrast enhancement in multidetector computed tomography of the liver using two contrast media with different iodine concentration (Iodixanol 320 mgI/mL and Iomeprol 400 mgI/mL) and similar viscosity, using fixed total iodine volume (40 gI) and iodine delivery rate (1.6 gI/s). Methods: 110 patients were prospectively randomized into two groups. Group A received 125 mL of Iodixanol 320 and group B 100 mL of Iomeprol 400. Attenuation values were measured at the level of the aorta, portal vein and liver parenchyma on unenhanced, arterial, portal and equilibrium phases. A non inferiority test was performed on the differences between the two groups. An independent reader evaluated image quality. Results: The equivalence of the two CM was demonstrated in all measurements. Higher, but not statistically significant, attenuation values were obtained with Iomeprol 400 in the aorta during the arterial phase (305.3 HU versus 288.4 HU; P = 0.32) and with Iodixanol 320 in the liver parenchyma, during both portal (59.8 HU versus 65.5 HU; P = 0.78) and equilibrium (40.4 HU versus 41.8 HU; P = 0.55) phases. Conclusions: Iodixanol 320 and Iomeprol 400 injected at the same iodine delivery rate (1.6 gI/s) and total iodine load (40 gI) did not provide statistically significant differences in liver parenchymal and vascular contrast enhancement.

  13. Instrumentation for multi-detector arrays

    Indian Academy of Sciences (India)

    R K Bhowmik

    2001-07-01

    The new generation of detector arrays require complex instrumentation and data acquisition system to ensure increased reliability of operation, high degree of integration, software control and faster data handling capability. The main features of some of the existing multi-detector arrays like MSU 4 array, Gammasphere and Eurogam are summarized. The instrumentation for the proposed INGA array in India is discussed.

  14. Giant Choledochal Cyst Mimicking Massive Gallbladder Hydrops in an Adult Patient: Multi Detector Computed Tomography and Magnetic Resonance Imaging Findings Correlated to Gross and Histopathological Findings

    Directory of Open Access Journals (Sweden)

    Joon-Il Choi

    2013-01-01

    Full Text Available Choledochal cysts are uncommon congenital anomalies of the biliary tree, commonly presenting in infancy, generally in the 1 st year of life. Presentation in adult life is less common, accounting for 20% of cases. A 19-year-old female patient presented to the Emergency Department with severe abdominal distension, a palpable abdominal mass, mild jaundice and low grade fever. Ultrasound, computed tomography (CT and magnetic resonance imaging of the abdomen showed a massive septated cystic lesion filling the entire abdomen with a significant mass effect on surrounding structures. Origin of the lesion was unclear and diagnosis included a giant mesenteric or duplication cyst, massive gallbladder with hydrops, biliary cystadenoma and giant choledochal cyst, among others. Final diagnosis was a Type IA choledochal cyst with massive asymmetric cystic dilatation of the extra-hepatic segments of the left hepatic duct with asymmetric dilatation of the right hepatic duct. Patient had an uneventful recovery after resection of the entire extrahepatic cyst and Roux-en-Y hepaticojejunostomy at the level of the hilum. In this article, we correlate CT and MRI findings to gross and histopathological findings of this giant Todani′s Type IA choledochal cyst.

  15. Quantification of normative ranges and baseline predictors of aortoventricular interface dimensions using multi-detector computed tomographic imaging in patients without aortic valve disease

    Energy Technology Data Exchange (ETDEWEB)

    Gooley, Robert P., E-mail: robert.gooley@monashhealth.org [MonashHeart, Monash Health, Melbourne 3168 (Australia); Monash Cardiovascular Research Centre, Department of Medicine (MMC), Monash University, Melbourne 3168 (Australia); Cameron, James D., E-mail: james.cameron@monash.edu [MonashHeart, Monash Health, Melbourne 3168 (Australia); Monash Cardiovascular Research Centre, Department of Medicine (MMC), Monash University, Melbourne 3168 (Australia); Soon, Jennifer, E-mail: jenn.sa@gmail.com [MonashHeart, Monash Health, Melbourne 3168 (Australia); Monash Cardiovascular Research Centre, Department of Medicine (MMC), Monash University, Melbourne 3168 (Australia); Loi, Duncan, E-mail: dloi2@student.monash.edu [Monash Cardiovascular Research Centre, Department of Medicine (MMC), Monash University, Melbourne 3168 (Australia); Chitale, Gauri, E-mail: gchi21@student.monash.edu [Monash Cardiovascular Research Centre, Department of Medicine (MMC), Monash University, Melbourne 3168 (Australia); Syeda, Rifath, E-mail: rssye1@student.monash.edu [Monash Cardiovascular Research Centre, Department of Medicine (MMC), Monash University, Melbourne 3168 (Australia); Meredith, Ian T., E-mail: ian.meredith@myheart.id.au [MonashHeart, Monash Health, Melbourne 3168 (Australia); Monash Cardiovascular Research Centre, Department of Medicine (MMC), Monash University, Melbourne 3168 (Australia)

    2015-09-15

    Highlights: • MDCT imaging of the aortoventricular interface is increasingly common. • We present normative ranges for aortoventricular interface dimensions. • Such techniques and ranges should be used to standardise reporting and research. - Abstract: Background: Multidetector computed tomographic (MDCT) assessment of the aortoventricular interface has gained increased importance with the advent of minimally invasive treatment modalities for aortic and mitral valve disease. This has included a standardised technique of identifying a plane through the nadir of each coronary cusp, the basal plane, and taking further measurements in relation to this plane. Despite this there is no published data defining normal ranges for these aortoventricular metrics in a healthy cohort. This study seeks to quantify normative ranges for MDCT derived aortoventricular dimensions and evaluate baseline demographic and anthropomorphic associates of these measurements in a normal cohort. Methods: 250 consecutive patients undergoing MDCT coronary angiography were included. Aortoventricular dimensions at multiple levels of the aortoventricular interface were assessed and normative ranges quantified. Multivariate linear regression was performed to identify baseline predictors of each metric. Results: The mean age was 59 ± 12 years. The basal plane was eccentric (EI = 0.22 ± 0.06) while the left ventricular outflow tract was more eccentric (EI = 0.32 ±0.06), with no correlation to gender, age or hypertension. Male gender, height and body mass index were consistent independent predictors of larger aortoventricular dimensions at all anatomical levels, while age was predictive of supra-annular measurements. Conclusions: Male gender, height and BMI are independent predictors of all aortoventricular dimensions while age predicts only supra-annular dimensions. Use of defined metrics such as the basal plane and formation of normative ranges for these metrics allows reference for clinical

  16. Accuracy of multi-detector computed tomography (MDCT) in staging of renal cell carcinoma (RCC): analysis of risk factors for mis-staging and its impact on surgical intervention.

    Science.gov (United States)

    El-Hefnawy, Ahmed S; Mosbah, Ahmed; El-Diasty, Tarek; Hassan, Mohammed; Shaaban, Atallah A

    2013-08-01

    To assess the accuracy of multi-detector computed tomography (MDCT) in preoperative staging of renal cell carcinoma (RCC) and to detect the possible risk factors for mis-staging. In addition, the impact of radiological mis-staging on surgical decision and operative procedures was evaluated. Data files of 693 patients, who underwent either radical or partial nephrectomy after preoperative staging by MDCT between January 2003 and December 2010, were retrospectively reviewed. Radiological data were compared to surgical and histopathological findings. Patients were classified according to 2009 TNM staging classification. Diagnostic accuracy per stage and its impact on surgical intervention were evaluated. The overall accuracy was 64.5%, and over-stage was detected in 29.5% and under-stage in 6%. Sensitivity and specificity were highest in stage T3b (85 and 99.5%, respectively), while T4 showed the lowest sensitivity and PPV (57 and 45%). Degree of agreement with pathological staging was substantial in T1 (κ = 0.7), fair in T2 (κ = 0. 4), perfect in T3b (κ = 0.81), and slight for the other stages (κ = 7 cm represent the significant risk factors (RR: 1.6, 95% CI: 1.1-2.3, P Mis-staging was seen to have no negative impact on surgical decision. MDCT is an accepted tool for renal tumor staging. Tumor mis-staging after MDCT is of little clinical importance. Large tumor size >7 cm and conventional RCC are risk factors for tumor mis-staging.

  17. Aortic and Hepatic Contrast Enhancement During Hepatic-Arterial and Portal Venous Phase Computed Tomography Scanning: Multivariate Linear Regression Analysis Using Age, Sex, Total Body Weight, Height, and Cardiac Output.

    Science.gov (United States)

    Masuda, Takanori; Nakaura, Takeshi; Funama, Yoshinori; Higaki, Toru; Kiguchi, Masao; Imada, Naoyuki; Sato, Tomoyasu; Awai, Kazuo

    We evaluated the effect of the age, sex, total body weight (TBW), height (HT) and cardiac output (CO) of patients on aortic and hepatic contrast enhancement during hepatic-arterial phase (HAP) and portal venous phase (PVP) computed tomography (CT) scanning. This prospective study received institutional review board approval; prior informed consent to participate was obtained from all 168 patients. All were examined using our routine protocol; the contrast material was 600 mg/kg iodine. Cardiac output was measured with a portable electrical velocimeter within 5 minutes of starting the CT scan. We calculated contrast enhancement (per gram of iodine: [INCREMENT]HU/gI) of the abdominal aorta during the HAP and of the liver parenchyma during the PVP. We performed univariate and multivariate linear regression analysis between all patient characteristics and the [INCREMENT]HU/gI of aortic- and liver parenchymal enhancement. Univariate linear regression analysis demonstrated statistically significant correlations between the [INCREMENT]HU/gI and the age, sex, TBW, HT, and CO (all P linear regression analysis showed that only the TBW and CO were of independent predictive value (P linear regression analysis only the TBW and CO were significantly correlated with aortic and liver parenchymal enhancement; the age, sex, and HT were not. The CO was the only independent factor affecting aortic and liver parenchymal enhancement at hepatic CT when the protocol was adjusted for the TBW.

  18. Characterization of renal cell carcinoma, oncocytoma, and lipid-poor angiomyolipoma by unenhanced, nephrographic, and delayed phase contrast-enhanced computed tomography.

    Science.gov (United States)

    Ishigami, Kousei; Pakalniskis, Marius G; Leite, Leandro V; Lee, Daniel K; Holanda, Danniele G; Rajput, Maheen

    2015-01-01

    The purpose of this study was to assess the characterization of renal cell carcinoma (RCC) and benign renal tumors by unenhanced, nephrographic, and delayed phase computed tomography (CT). The study group consisted of 129 renal tumors including 79 clear cell RCCs, 17 papillary RCCs, 6 chromophobe RCCs, 21 oncocytoma, and 6 lipid-poor angiomyolipomas (AMLs). CT studies were retrospectively reviewed. Our results suggested that it was possible to discriminate clear cell RCC from papillary RCC, chromophobe RCC, and lipid-poor AML. CT findings of oncocytoma overlapped with both clear cell and non-clear cell RCCs, although oncocytoma more commonly became homogeneous in the delayed phase.

  19. Pitfalls in detection of acute gastrointestinal bleeding with multi-detector row helical CT.

    Science.gov (United States)

    Stuber, T; Hoffmann, M H K; Stuber, G; Klass, O; Feuerlein, S; Aschoff, A J

    2009-07-01

    Contrast-enhanced multi-detector row helical CT angiography is establishing itself as an accurate, rapid, and non-invasive diagnostic modality in patients with acute gastrointestinal bleeding. On arterial phase MDCT images ongoing hemorrhage can be revealed as an area of active extravasation of contrast material within the bowel lumen. This pictorial essay gives a short overview of current diagnostic modalities in assessing acute GI tract bleeding, typical MDCT findings, and depicts potential pitfalls in the detection of acute GI bleeding with MDCT.

  20. A Computer-Aided Diagnosis System for Dynamic Contrast-Enhanced MR Images Based on Level Set Segmentation and ReliefF Feature Selection

    Directory of Open Access Journals (Sweden)

    Zhiyong Pang

    2015-01-01

    Full Text Available This study established a fully automated computer-aided diagnosis (CAD system for the classification of malignant and benign masses via breast magnetic resonance imaging (BMRI. A breast segmentation method consisting of a preprocessing step to identify the air-breast interfacing boundary and curve fitting for chest wall line (CWL segmentation was included in the proposed CAD system. The Chan-Vese (CV model level set (LS segmentation method was adopted to segment breast mass and demonstrated sufficiently good segmentation performance. The support vector machine (SVM classifier with ReliefF feature selection was used to merge the extracted morphological and texture features into a classification score. The accuracy, sensitivity, and specificity measurements for the leave-half-case-out resampling method were 92.3%, 98.2%, and 76.2%, respectively. For the leave-one-case-out resampling method, the measurements were 90.0%, 98.7%, and 73.8%, respectively.

  1. Resting myocardial blood flow quantification using contrast-enhanced magnetic resonance imaging in the presence of stenosis: A computational fluid dynamics study

    Energy Technology Data Exchange (ETDEWEB)

    Sommer, Karsten, E-mail: sommerk@uni-mainz.de, E-mail: Schreiber-L@ukw.de [Section of Medical Physics, Department of Radiology, Johannes Gutenberg University Medical Center, Mainz 55131, Germany and Max Planck Graduate Center with the Johannes Gutenberg University Mainz, Mainz 55128 (Germany); Bernat, Dominik; Schmidt, Regine; Breit, Hanns-Christian [Section of Medical Physics, Department of Radiology, Johannes Gutenberg University Medical Center, Mainz 55131 (Germany); Schreiber, Laura M., E-mail: sommerk@uni-mainz.de, E-mail: Schreiber-L@ukw.de [Comprehensive Heart Failure Center, Department of Cardiovascular Imaging, Würzburg University Hospital, Würzburg 97078 (Germany)

    2015-07-15

    Purpose: The extent to which atherosclerotic plaques affect contrast agent (CA) transport in the coronary arteries and, hence, quantification of myocardial blood flow (MBF) using magnetic resonance imaging (MRI) is unclear. The purpose of this work was to evaluate the influence of plaque induced stenosis both on CA transport and on the accuracy of MBF quantification. Methods: Computational fluid dynamics simulations in a high-detailed realistic vascular model were employed to investigate CA bolus transport in the coronary arteries. The impact of atherosclerosis was analyzed by inserting various medium- to high-grade stenoses in the vascular model. The influence of stenosis morphology was examined by varying the stenosis shapes but keeping the area reduction constant. Errors due to CA bolus transport were analyzed using the tracer-kinetic model MMID4. Results: Dispersion of the CA bolus was found in all models and for all outlets, but with a varying magnitude. The impact of stenosis was complex: while high-grade stenoses amplified dispersion, mild stenoses reduced the effect. Morphology was found to have a marked influence on dispersion for a small number of outlets in the post-stenotic region. Despite this marked influence on the concentration–time curves, MBF errors were less affected by stenosis. In total, MBF was underestimated by −7.9% to −44.9%. Conclusions: The presented results reveal that local hemodynamics in the coronary vasculature appears to have a direct impact on CA bolus dispersion. Inclusion of atherosclerotic plaques resulted in a complex alteration of this effect, with both degree of area reduction and stenosis morphology affecting the amount of dispersion. This strong influence of vascular transport effects impairs the accuracy of MRI-based MBF quantification techniques and, potentially, other bolus-based perfusion measurement techniques like computed tomography perfusion imaging.

  2. Double Chooz Improved Multi-Detector Measurements

    CERN Document Server

    CERN. Geneva

    2016-01-01

    The Double Chooz experiment (DC) is a reactor neutrino oscillation experiment running at Chooz nuclear power plant (2 reactors) in France. In 2011, DC first reported indication of non-zero θ13 with the far detector (FD) located at the maximum of oscillation effects (i.e. disappearance), thus challenging the CHOOZ non-observation limit. A robust observation of θ13 followed in 2012 by the Daya Bay experiments with multiple detector configurations. Since 2015 DC runs in a multi-detector configuration making thus the impact of several otherwise dominating systematics reduce strongly. DC’s unique almost "iso-flux" site, allows the near detector (ND) to become a direct accurate non-oscillation reference to the FD. Our first multi-detector results at MORIOND-2016 showed an intriguing deviation of θ13 with respect to the world average. We will address this issue in this seminar. The combined "reactor-θ13" measurement is expected to ...

  3. Comparison of imaging strategies with conditional versus immediate contrast-enhanced computed tomography in patients with clinical suspicion of acute appendicitis

    Energy Technology Data Exchange (ETDEWEB)

    Atema, J.J.; Gans, S.L.; Boermeester, M.A. [Academic Medical Centre, Department of Surgery (G4-142), Amsterdam (Netherlands); Randen, A. van; Stoker, J. [Academic Medical Centre, Department of Radiology, Amsterdam (Netherlands); Lameris, W. [Academic Medical Centre, Department of Surgery (G4-142), Amsterdam (Netherlands); Spaarne Hospital, Department of Surgery, Hoofddorp (Netherlands); Es, H.W. van; Heesewijk, J.P.M. van [St Antonius Hospital, Department of Radiology, Nieuwegein (Netherlands); Ramshorst, B. van [St Antonius Hospital, Department of Surgery, Nieuwegein (Netherlands); Bouma, W.H. [Gelre Hospital, Department of Surgery, Apeldoorn (Netherlands); Hove, W. ten [Gelre Hospital, Department of Radiology, Apeldoorn (Netherlands); Keulen, E.M. van [Tergooi Hospital, Department of Radiology, Hilversum (Netherlands); Dijkgraaf, M.G.W. [Academic Medical Centre, Clinical Research Unit, Amsterdam (Netherlands); Bossuyt, P.M.M. [Academic Medical Center, Department of Clinical Epidemiology, Biostatistics, and Bioinformatics, Amsterdam (Netherlands)

    2015-08-15

    To compare the diagnostic accuracy of conditional computed tomography (CT), i.e. CT when initial ultrasound findings are negative or inconclusive, and immediate CT for patients with suspected appendicitis. Data were collected within a prospective diagnostic accuracy study on imaging in adults with acute abdominal pain. All patients underwent ultrasound and CT, read by different observers who were blinded from the other modality. Only patients with clinical suspicion of appendicitis were included. An expert panel assigned a final diagnosis to each patient after 6 months of follow-up (clinical reference standard). A total of 422 patients were included with final diagnosis appendicitis in 251 (60 %). For 199 patients (47 %), ultrasound findings were inconclusive or negative. Conditional CT imaging correctly identified 241 of 251 (96 %) appendicitis cases (95 %CI, 92 % to 98 %), versus 238 (95 %) with immediate CT (95 %CI, 91 % to 97 %). The specificity of conditional CT imaging was lower: 77 % (95 %CI, 70 % to 83 %) versus 87 % for immediate CT (95 %CI, 81 % to 91 %). A conditional CT strategy correctly identifies as many patients with appendicitis as an immediate CT strategy, and can halve the number of CTs needed. However, conditional CT imaging results in more false positives. (orig.)

  4. Comparison of diagnostic performance between single- and multiphasic contrast-enhanced abdominopelvic computed tomography in patients admitted to the emergency department with abdominal pain: potential radiation dose reduction

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, Shin Hye; You, Je Sung; Choi, Jin-Young; Kim, Myeong-Jin; Chung, Yong Eun [Yonsei University College of Medicine, Department of Radiology, Research Institute of Radiological Science, Seodaemun-gu, Seoul (Korea, Republic of); Song, Mi Kyong [Yonsei University, Biostatistics Collaboration Unit, College of Medicine, Seoul (Korea, Republic of)

    2015-04-01

    To evaluate feasibility of radiation dose reduction by optimal phase selection of computed tomography (CT) in patients who visited the emergency department (ED) for abdominal pain. We included 253 patients who visited the ED for abdominal pain. They underwent multiphasic CT including precontrast, late arterial phase (LAP), and hepatic venous phase (HVP). Three image sets (HVP, precontrast + HVP, and precontrast + LAP + HVP) were reviewed. Two reviewers determined the most appropriate diagnosis with five-point confidence scale. Diagnostic performances were compared among image sets by weighted-least-squares method or DeLong's method. Linear mixed model was used to assess changes of diagnostic confidence and radiation dose. There was no difference in diagnostic performance among three image sets, although diagnostic confidence level was significantly improved after review of triphasic images compared with both HVP images only or HVP with precontrast images (confidence scale, 4.64 ± 0.05, 4.66 ± 0.05, and 4.76 ± 0.04 in the order of the sets; overall P = 0.0008). Similar trends were observed in the subgroup analysis for diagnosis of pelvic inflammatory disease and cholecystitis. There is no difference between HVP-CT alone and multiphasic CT for the diagnosis of causes of abdominal pain in patients admitted to the ED without prior chronic disease or neoplasia. (orig.)

  5. Rectal contrast-enhanced computed tomography in the diagnosis of acute appendicitis; Tomografia computarizada con contraste rectal en el diagnostico de la apendicitis aguda

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-07-01

    To assess the efficacy and utility of computed tomography (CT) in the diagnosis of appendicitis, and to evaluate the reliability of CT findings in right iliac fossa in the confirmation or exclusion of this diagnosis. Over a one-year period, 152 patients presenting clinical signs of appendicitis underwent CT scans. The images were reviewed by two radiologists who considered whether the appendix was normal or enlarged and the existence of other signs of appendicitis for the purpose of determining whether or not the patient presented appendicitis. The definitive diagnoses were established by surgery or by clinical follow-up. The sensitivity of CT for the diagnosis of appendicitis was 81.8%, the specificity was 95.3%, the positive predictive value was 93.1%, the negative predictive value was 87.2% and the reliability was 89.9%. The signs of appendicitis observed were: appendicoliths (sensitivity 30.3% and specificity 98.8%), fluid collections (sensitivity 19.7%, specificity 96.5%), cecal enlargement (sensitivity 21.2%, specificity 97.7%), inflammation of pericecal fat (sensitivity 72.7%, specificity 90.7%), fascial thickening (sensitivity 48.5%, specificity 91.9%) and an appendix measuring more than 6 mm (sensitivity 78.8%, specificity 94.3%). Adenopathy and free peritoneal fluid were not significantly related to appendicitis. The presence of a normal appendix filled with air or contrast material had an elevated negative predictive value with respect to appendicitis. In 35 of the 94 cases with negative CT scans, the images suggested alternative diagnoses. CT is a highly reliable diagnostic method for appendicitis. The observation of an appendix filled with air or contrast material has an elevated negative predictive value. The presence of appendicoliths has an elevated positive predictive value. (Author) 29 refs.

  6. Contrast-enhanced angiographic computed tomography for detection of aneurysm remnants after clipping: a comparison with digital subtraction angiography in 112 clipped aneurysms.

    Science.gov (United States)

    Gölitz, Philipp; Struffert, Tobias; Ganslandt, Oliver; Lang, Stefan; Knossalla, Frauke; Doerfler, Arnd

    2014-06-01

    For preclusion of remnants after aneurysm clipping, a reliable, noninvasive imaging technique is desirable. To evaluate the reliability of optimized angiographic computed tomography with intravenous contrast agent injection (ivACT) in detecting remnants after aneurysmal clipping compared with digital subtraction angiography (DSA), the gold standard. We included 84 patients with 112 clipped cerebral aneurysms of the anterior circulation. For treatment, 116 clips of cobalt and 57 clips of titanium alloy were used. In each patient, we performed an ivACT with dual rotational acquisition and a DSA. Data from ivACT were postprocessed with a dual-volume technique with newly implemented reconstructions modes. Aneurysm remnants were measured, classified, and correlated with DSA by 2 raters. In total, 12 remnants were revealed by DSA, meaning a prevalence of 11%. IvACT demonstrated a sensitivity of 75% to 92% and a specificity of 99% in detecting remnants up to a minimal size of 0.7 × 0.3 mm. Classification of remnants by ivACT was identical to that by DSA, and assessment of size showed a significant correlation with DSA (P < .001). No significant differences between cobalt and titanium alloy were revealed concerning artifacts. Optimized ivACT with enhanced postprocessing demonstrated high sensitivity and specificity in detecting remnants after aneurysm clipping in the anterior circulation. Classification and assessment of remnant size and detection of relevant parent artery stenosis showed high accuracy of ivACT compared with DSA. Our results indicate that ivACT might become a noninvasive alternative to DSA for postsurgical control.

  7. Image fusion in dual energy computed tomography for detection of various anatomic structures - Effect on contrast enhancement, contrast-to-noise ratio, signal-to-noise ratio and image quality

    Energy Technology Data Exchange (ETDEWEB)

    Paul, Jijo, E-mail: jijopaul1980@gmail.com [Department of Diagnostic Radiology, Goethe University Hospital, Theodor-Stern-Kai 7, 60590 Frankfurt am Main (Germany); Department of Biophysics, Goethe University, Max von Laue-Str.1, 60438 Frankfurt am Main (Germany); Bauer, Ralf W. [Department of Diagnostic Radiology, Goethe University Hospital, Theodor-Stern-Kai 7, 60590 Frankfurt am Main (Germany); Maentele, Werner [Department of Biophysics, Goethe University, Max von Laue-Str.1, 60438 Frankfurt am Main (Germany); Vogl, Thomas J. [Department of Diagnostic Radiology, Goethe University Hospital, Theodor-Stern-Kai 7, 60590 Frankfurt am Main (Germany)

    2011-11-15

    Objective: The purpose of this study was to evaluate image fusion in dual energy computed tomography for detecting various anatomic structures based on the effect on contrast enhancement, contrast-to-noise ratio, signal-to-noise ratio and image quality. Material and methods: Forty patients underwent a CT neck with dual energy mode (DECT under a Somatom Definition flash Dual Source CT scanner (Siemens, Forchheim, Germany)). Tube voltage: 80-kV and Sn140-kV; tube current: 110 and 290 mA s; collimation-2 x 32 x 0.6 mm. Raw data were reconstructed using a soft convolution kernel (D30f). Fused images were calculated using a spectrum of weighting factors (0.0, 0.3, 0.6 0.8 and 1.0) generating different ratios between the 80- and Sn140-kV images (e.g. factor 0.6 corresponds to 60% of their information from the 80-kV image, and 40% from the Sn140-kV image). CT values and SNRs measured in the ascending aorta, thyroid gland, fat, muscle, CSF, spinal cord, bone marrow and brain. In addition, CNR values calculated for aorta, thyroid, muscle and brain. Subjective image quality evaluated using a 5-point grading scale. Results compared using paired t-tests and nonparametric-paired Wilcoxon-Wilcox-test. Results: Statistically significant increases in mean CT values noted in anatomic structures when increasing weighting factors used (all P {<=} 0.001). For example, mean CT values derived from the contrast enhanced aorta were 149.2 {+-} 12.8 Hounsfield Units (HU), 204.8 {+-} 14.4 HU, 267.5 {+-} 18.6 HU, 311.9 {+-} 22.3 HU, 347.3 {+-} 24.7 HU, when the weighting factors 0.0, 0.3, 0.6, 0.8 and 1.0 were used. The highest SNR and CNR values were found in materials when the weighting factor 0.6 used. The difference CNR between the weighting factors 0.6 and 0.3 was statistically significant in the contrast enhanced aorta and thyroid gland (P = 0.012 and P = 0.016, respectively). Visual image assessment for image quality showed the highest score for the data reconstructed using the

  8. Contrast Enhancement Using Brightness Preserving Histogram Plateau Limit Technique

    Directory of Open Access Journals (Sweden)

    K. Santhi

    2014-07-01

    Full Text Available Contrast enhancement is an important factor in the gray scale images. One of the widely accepted contrast enhancement method is the Histogram equalization (HE. HE achieves comparatively better performance on almost all types of image but sometimes produces excessive visual deterioration. The proposed Contrast Enhancement using Brightness Preserving Histogram Plateau Limit (CEBPHPL method provides better brightness preservation without allowing in excess of contrast improvement measure. This method decomposes the input image by computing the local maxima of the smoothed image using Gaussian filter which reduces the noise. Then the clipping process has been implemented which provides the good enhancement rate than the conventional methods. The experimental result of the proposed CEBPHPL is better than the existing methods.

  9. Contrast Enhanced US in the Abdomen

    Energy Technology Data Exchange (ETDEWEB)

    Chung, Yong Eun; Kim, Ki Whang [Dept. of Radiology, Research Institute of Radiological Science, Severance Hospital, Yonsei University College of Medicine, Seoul (Korea, Republic of)

    2012-08-15

    Contrast enhanced ultrasound, which was introduced in 1996, has been widely used in Europe and Eastern Asia. Ultrasound contrast agent can be classified as first generation and second generation, depending on the gas within the microbubble. With the first generation contrast agent, the high MI technique was used, and only intermittent scanning was possible due to destruction of the microbubble during scanning. Use of the second generation contrast agent with the low MI technique makes continuous scanning possible. Contrast enhanced US can be used in detection and differentiation of focal liver lesions. It is also helpful for monitoring of radiofrequency ablation and for targeting of US guided biopsy. Currently, because morphologic criteria alone may not reflect the response of the tumor to treatment, new criteria are needed for treatment evaluation after administration of anti-angiogenic agents. Contrast enhanced US could provide quantitative markers for evaluation of the response to treatment via use of dynamic contrast enhanced US. Due to cost-effectiveness, contrast enhanced US is not yet widely used in Korea; however, considering recent issues regarding contrast agent related adverse reaction, such as contrast induced nephropathy and nephrogenic systemic fibrosis, and radiation exposure, contrast enhanced US might be more widely used in Korea, as an alternative imaging modality in the future.

  10. Contrast-enhanced harmonic endoscopic ultrasound

    DEFF Research Database (Denmark)

    Săftoiu, A; Dietrich, C F; Vilmann, P

    2012-01-01

    Second-generation intravenous blood-pool ultrasound contrast agents are increasingly used in endoscopic ultrasound (EUS) for characterization of microvascularization, differential diagnosis of benign and malignant focal lesions, and improving staging and guidance of therapeutic procedures. Although...... contrast-enhanced harmonic EUS based on a very low mechanical index (0.08 - 0.12). Quantification techniques based on dynamic contrast-enhanced ultrasound have been recommended for perfusion imaging and monitoring of anti-angiogenic treatment, mainly based on time-intensity curve analysis. Most...

  11. Post-traumatic contrast enhancing brain lesion

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Dae Jung; Kim, Hyun Sook; Jeong, Min Sun; Kim, Deok Ryeong; Cho, Young Kwon; Choi, Yun Sun [Eulji Hospital, Eulji University College of Medicine, Seoul (Korea, Republic of)

    2014-10-15

    Only a few studies have been reported on the MR contrast enhancement and the apparent diffusion coefficient (ADC) findings of the post-traumatic lesion of the brain. We report a case of the venous ischemia in the left frontal lobe observed in the MRI obtained one day after the incidence of trauma. Considering the presented slight increase in the ADC, the vasogenic edema was thought to be the major mechanism of the venous ischemia and excitotoxic injury. In spite of a slight increase in the ADC, the hyperintensity in the diffusion weighted imaging and contrast-enhanced areas eventually changed into hemorrhagic lesions.

  12. Assessment of Acute Antivascular Effects of Vandetanib with High-Resolution Dynamic Contrast-Enhanced Computed Tomographic Imaging in a Human Colon Tumor Xenograft Model in the Nude Rat

    Directory of Open Access Journals (Sweden)

    Joo Ho Tai

    2010-09-01

    Full Text Available Tumor size is not a reliable marker for the assessment of early antivascular effects of antiangiogenics. In the present study, we used 200-µm in-plane high-resolution dynamic contrast-enhanced computed tomography (DCE-CT to noninvasively assess the immediate antivascular effects of vandetanib in a subcutaneous human colon cancer (LoVo xenograft model in nude rats and to investigate correlation between changes in CT perfusion parameters and tumor volume or immunohistochemical end points. At 3 to 4 weeks after LoVo cell implantation, the animal was gavaged with either vandetanib (50 mg/kg or vehicle twice (22 hours apart and scanned with a preclinical DCE-CT scanner before (0 hour and after treatment (24 hours. Quantitative maps of blood flow (BF and volume (BV of the tumor were calculated from the acquired DCE-CT images. The rats were divided into nonhypovascular, hypovascular, and combined (regardless of vascularity groups. In the nonhypovascular group, significant decreases in both tumor BF and BV were observed in the vandetanib-treated rats compared with increases in the vehicle-treated rats. A significant decrease in BV was detected in the vandetanib-treated rats in the combined group as well. No differences in tumor growth, vascular endothelial growth factor expression, microvessel density, or apoptosis were observed between vandetanib- and vehicle-treated rats in all three groups. These results demonstrate that BF and BV imaging biomarkers from DCE-CT imaging can be used for rapid monitoring of immediate (24 hours after antimicrovascular effects of vandetanib on tumors, even in the absence of significant changes of tumor volume or clinically relevant immunohistochemical end points.

  13. Micro–Positron Emission Tomography/Contrast-Enhanced Computed Tomography Imaging of Orthotopic Pancreatic Tumor–Bearing Mice Using the αvβ3 Integrin Tracer 64Cu-Labeled Cyclam-RAFT-c(-RGDfK-4

    Directory of Open Access Journals (Sweden)

    Winn Aung

    2013-09-01

    Full Text Available The purpose of this study was to develop a clinically relevant orthotopic xenotransplantation model of pancreatic cancer and to perform a preclinical evaluation of a new positron emission tomography (PET imaging probe, 64Cu-labeled cyclam-RAFT-c(-RGDfK-4 peptide (64Cu-RAFT-RGD, using this model. Varying degrees of αvβ3 integrin expression in several human pancreatic cancer cell lines were examined by flow cytometry and Western blotting. The cell line BxPC-3, which is stably transfected with a red fluorescence protein (RFP, was used for surgical orthotopic implantation. Orthotopic xenograft was established in the pancreas of recipient nude mice. An in vivo probe biodistribution and receptor blocking study, preclinical PET imaging coregistered with contrast-enhanced computed tomography (CECT comparing 64Cu-RAFT-RGD and 18F-fluoro-2-deoxy-D-glucose (18F-FDG accumulation in tumor, postimaging autoradiography, and histologic and immunohistochemical examinations were done. Biodistribution evaluation with a blocking study confirmed that efficient binding of probe to tumor is highly αvβ3 integrin specific. 64Cu-RAFT-RGD PET combined with CECT provided for precise and easy detection of cancer lesions. Autoradiography, histologic, and immunohistochemical examinations confirmed the accumulation of 64Cu-RAFT-RGD in tumor versus nontumor tissues. In comparative PET studies, 64Cu-RAFT-RGD accumulation provided better tumor contrast to background than 18F-FDG. Our results suggest that 64Cu-RAFT-RGD PET imaging is potentially applicable for the diagnosis of αvβ3 integrin–expressing pancreatic tumors.

  14. Dynamic Contrast-Enhanced Magnetic Resonance Enterography and Dynamic Contrast-Enhanced Ultrasonography in Crohn's Disease

    DEFF Research Database (Denmark)

    Wilkens, Rune; Peters, David A; Nielsen, Agnete Hedemann

    2017-01-01

    Purpose e Cross-sectional imaging methods are important for objective evaluationof small intestinal inflammationinCrohn'sdisease(CD).The primary aim was to compare relative parameters of intestinal perfusion between contrast-enhanced ultrasonography (CEUS) and dynamic contrast-enhanced magnetic...

  15. Image evolution approach for contrast enhancement

    Science.gov (United States)

    Sapiro, Guillermo; Casalles, Vicent

    1995-09-01

    An algorithm for histogram modification via image evolution equations is first presented in this paper. We show that the image histogram can be modified to achieve any given distribution as the steady state solution of this partial differential equation. We then prove that this equation corresponds to a gradient descent flow of a variational problem. That is, the proposed PDE is solving an energy minimization problem. This gives a new interpretation to histogram modification and contrast enhancement in general. This interpretation is completely formulated in the image domain, in contrast with classical techniques for histogram modification which are formulated in a probabilistic domain. From this, new algorithms for contrast enhancement, which include for example, image modeling, can be derived. Based on the energy formulation and its corresponding PDE, we show that the proposed histogram modification algorithm can be combined with denoising schemes. This allows to perform simultaneous contrast enhancement and denoising, avoiding common noise sharpening effects in classical algorithms. The approach is extended to local contrast enhancement as well. Theoretical results regarding the existence of solutions of the proposed equations are presented.

  16. International guidelines for contrast-enhanced ultrasonography

    DEFF Research Database (Denmark)

    Nolsøe, Christian Pállson; Lorentzen, Torben

    2016-01-01

    The intent of this review is to discuss and comment on common clinical scenarios in which contrast-enhanced ultrasonography (CEUS) may play a decisive role and to illustrate important points with typical cases. With the advent of CEUS, the scope of indications for ultrasonography has been...

  17. Contrast-enhanced dedicated breast CT detection of invasive breast cancer preceding mammographic diagnosis

    Directory of Open Access Journals (Sweden)

    Nicolas D. Prionas, MD, PhD

    2015-01-01

    Full Text Available Dedicated breast computed tomography (bCT generates high-resolution, three-dimensional images of the pendent uncompressed breast. Intravenous iodinated contrast during bCT provides additional physiologic information. In this case, a 10.0-mm invasive ductal carcinoma was visualized using contrast-enhanced breast CT one year before mammographic detection. Mammography four months before bCT was negative. The bCT contrast enhancement pattern closely matched the dynamic contrast-enhanced MRI obtained after diagnosis. Lesion enhancement at contrast-enhanced breast CT matched previously published enhancement values of breast cancer. Contrast-enhanced dedicated bCT provided high-resolution tomographic images and physiologic contrast enhancement data that facilitated the detection of an early breast cancer.

  18. Value of contrast-enhanced CT in detecting arterial injury with pelvic fracture

    Energy Technology Data Exchange (ETDEWEB)

    Ito, Keigo; Iwase, Toshiki; Ohshima, Takeshi; Tsuboi, Masaki; Sugiura, Sakae; Hara, Suguru [Okazaki City Hospital, Aichi (Japan)

    2000-04-01

    Computed tomography (CT) was used for detecting ongoing pelvic hemorrhage in patients with pelvic fracture, and for deciding an indication or transcatheter arterial embolization. The authors compared plane CT with contrast-enhanced CT to examine the value of contrast-enhanced CT in detecting arterial injury with pelvic fracture. The diagnosis of arterial injury was made by angiography. CT-determined hematoma was detected in 10 parts according to bleeding sites. Each hematoma was counted and compared with angiographic arterial injury. Contrast-enhanced CT was more useful than plane CT, but the hemorrhage sites determined by contrast-enhanced CT were not identical with those of angiographic arterial injuries. (author)

  19. A quantitative comparison of gross tumor volumes delineated on [18F]-FDG-PET/CT scan and contrast-enhanced computed tomography scan in locally advanced head and neck carcinoma treated with Intensity Modulated Radiotherapy

    Directory of Open Access Journals (Sweden)

    Nagarjuna Burela

    2017-05-01

    Full Text Available Accurate tumor diagnosis is important in highly conformal techniques such as Intensity Modulated Radiotherapy (IMRT, which aims for high therapeutic ratio. We compared Gross Tumor Volume (GTV (primary and nodal delineated on 18F-fluorodeoxyglucose positron emission tomography ([18F]-FDG-PET scan to those delineated on contrast-enhanced computed tomography (CECT scan and its impact on staging treated by IMRT. A total of 30 consecutive patients with locally advanced squamous cell carcinoma of head and neck were included in this study. FDG-PET and CECT scans were performed with dedicated positron emission tomography–computed tomography (PET/CT scanner in a single session as part of radiotherapy treatment planning for IMRT. After treatment with concurrent chemoradiotherapy, all patients were followed for one year. Three out of 30 patients were excluded from the final analysis, as there was complete remission in PET/CT after neoadjuvant chemotherapy. For remaining 27 cases, the primary sites were 17 oropharynx, 2 hypopharynx, 7 larynx and 1 unknown primary with secondary neck node. PET–CT resulted in changes of CT-based staging in 25% patients (up-staged in 3 and down-staged in 4. GTV delineated on PET vs CT scan was GTV-PET (primary of 20.15 cm3 vs GTV-CT (primary of 18.75 cm3, p = 0.803; and GTV-PET (nodes of 28.45 cm3 vs GTV-CT (nodes of 21.56 cm3, p = 0.589. The mismatch between two target volumes was statistically insignificant (p = 0.635 for GTV primary, p = 0.187 for nodes. The mean GTV-PET outside CT for primary was 5.83 cm3, and for node was 8.47 cm3. Median follow-up was 12 months. One-year loco-regional control was 92%. The target delineation of GTV can be improved with functional imaging [18F]-FDG-PET/CT.

  20. Metabolomics of Breast Cancer Using High-Resolution Magic Angle Spinning Magnetic Resonance Spectroscopy: Correlations with 18F-FDG Positron Emission Tomography-Computed Tomography, Dynamic Contrast-Enhanced and Diffusion-Weighted Imaging MRI.

    Directory of Open Access Journals (Sweden)

    Haesung Yoon

    Full Text Available Our goal in this study was to find correlations between breast cancer metabolites and conventional quantitative imaging parameters using high-resolution magic angle spinning (HR-MAS magnetic resonance spectroscopy (MRS and to find breast cancer subgroups that show high correlations between metabolites and imaging parameters.Between August 2010 and December 2013, we included 53 female patients (mean age 49.6 years; age range 32-75 years with a total of 53 breast lesions assessed by the Breast Imaging Reporting and Data System. They were enrolled under the following criteria: breast lesions larger than 1 cm in diameter which 1 were suspicious for malignancy on mammography or ultrasound (US, 2 were pathologically confirmed to be breast cancer with US-guided core-needle biopsy (CNB 3 underwent 3 Tesla MRI with dynamic contrast-enhanced (DCE and diffusion-weighted imaging (DWI and positron emission tomography-computed tomography (PET-CT, and 4 had an attainable immunohistochemistry profile from CNB. We acquired spectral data by HR-MAS MRS with CNB specimens and expressed the data as relative metabolite concentrations. We compared the metabolites with the signal enhancement ratio (SER, maximum standardized FDG uptake value (SUV max, apparent diffusion coefficient (ADC, and histopathologic prognostic factors for correlation. We calculated Spearman correlations and performed a partial least squares-discriminant analysis (PLS-DA to further classify patient groups into subgroups to find correlation differences between HR-MAS spectroscopic values and conventional imaging parameters.In a multivariate analysis, the PLS-DA models built with HR-MAS MRS metabolic profiles showed visible discrimination between high and low SER, SUV, and ADC. In luminal subtype breast cancer, compared to all cases, high SER, ADV, and SUV were more closely clustered by visual assessment. Multiple metabolites were correlated with SER and SUV in all cases. Multiple metabolites

  1. Is intravenous contrast enhancement effective in improving CT diagnosis of hepatic disease?

    Energy Technology Data Exchange (ETDEWEB)

    Ito, Katsuhide; Ono, Chiaki [Hiroshima Univ. (Japan). Hospital; Kohno, Atsushi[Japanese Foundation for Cancer Research, Tokyo (Japan). Hospital; Sumi, Yukiharu [Juntendo Univ., Chiba (Japan). Urayasu Hospital; Honda, Masanori [Saiseikai Utsunomiya Hospital (Japan); Uchimura, Fumiaki [Yamagata Prefectural Nihonkai Hospital, Sakata (Japan); Ogawa, Kenji [Nihon Koukan Hospital, Kawasaki, Kanagawa (Japan); Ohtaki, Megu [Hiroshima Univ. (Japan). Research Inst. for Radiation Biology and Medicine

    2003-03-01

    The purpose of this study was to evaluate the effectiveness of contrast enhancement in the diagnosis of hepatic disease. 2761 cases involving CT of the liver and abdomen were analyzed using logistic analysis. CT was either helical-CT (SDCT) or multi-detector CT (MDCT), with power injector. Contrast enhancement use was 92% in liver disease and 95% in tumor cases. A typical case involved a 66-year-old man given 2-4 ml/sec of contrast material using dual injection. CT imaging was done in the equilibrium stage. The use of contrast material was effective for the diagnosis of liver tumor except in the qualitative diagnosis of hepatocellular carcinoma with SDCT where the odds ratio was 0.084. Intravenous contrast enhancement was effective for the CT diagnosis of hepatic tumor. Dynamic CT was effective using MDCT, and dual injection of contrast material was also valid for SDCT. Multiphasic studies were needed for detecting liver tumors not only on MDCT but also on SDCT. CT imaging during the equilibrium phase alone is inadequate to document diagnosis of metastatic liver tumors. The addition of various phasic contrast materials during CT was effective in evaluating liver tumors that showed angiogenesis. (author)

  2. Adaptive overlapped sub-blocks contrast enhancement

    Science.gov (United States)

    Chen, Anqiu; Yuan, Fei; Liu, Jing; Liu, Siqi; Li, An; Zheng, Zhenrong

    2016-09-01

    In this paper, an overlapped sub-block gray-level average method for contrast enhancement is presented. The digital image correction of uneven illumination under microscope transmittance is a problem in image processing, also sometimes the image in the dark place need to correct the uneven problem. A new correction method was proposed based on the mask method and sub-blocks gray-level average method because Traditional mask method and background fitting method are restricted due to application scenarios, and the corrected image brightness is low by using background fitting method, so it has some limitations of the application. In this paper, we introduce a new method called AOSCE for image contrast enhancement. The image is divided into many sub-blocks which are overlapped, calculate the average gray-level of the whole image as M and the calculate the average gray-level of each one as mi, next for each block it can get d = mi - m, each block minus d to get a new image, and then get the minimum gray-level of each block into a matrix DD to get the background, and use bilinearity to get the same scale of the image. over fitting the image in matlab in order to get smoother image, then minus the background to get the contrast enhancement image.

  3. Contrast enhancement via texture region based histogram equalization

    Science.gov (United States)

    Singh, Kuldeep; Vishwakarma, Dinesh K.; Singh Walia, Gurjit; Kapoor, Rajiv

    2016-08-01

    This paper presents two novel contrast enhancement approaches using texture regions-based histogram equalization (HE). In HE-based contrast enhancement methods, the enhanced image often contains undesirable artefacts because an excessive number of pixels in the non-textured areas heavily bias the histogram. The novel idea presented in this paper is to suppress the impact of pixels in non-textured areas and to exploit texture features for the computation of histogram in the process of HE. The first algorithm named as Dominant Orientation-based Texture Histogram Equalization (DOTHE), constructs the histogram of the image using only those image patches having dominant orientation. DOTHE categories image patches into smooth, dominant or non-dominant orientation patches by using the image variance and singular value decomposition algorithm and utilizes only dominant orientation patches in the process of HE. The second method termed as Edge-based Texture Histogram Equalization, calculates significant edges in the image and constructs the histogram using the grey levels present in the neighbourhood of edges. The cumulative density function of the histogram formed from texture features is mapped on the entire dynamic range of the input image to produce the contrast-enhanced image. Subjective as well as objective performance assessment of proposed methods is conducted and compared with other existing HE methods. The performance assessment in terms of visual quality, contrast improvement index, entropy and measure of enhancement reveals that the proposed methods outperform the existing HE methods.

  4. Adaptive image contrast enhancement algorithm for point-based rendering

    Science.gov (United States)

    Xu, Shaoping; Liu, Xiaoping P.

    2015-03-01

    Surgical simulation is a major application in computer graphics and virtual reality, and most of the existing work indicates that interactive real-time cutting simulation of soft tissue is a fundamental but challenging research problem in virtual surgery simulation systems. More specifically, it is difficult to achieve a fast enough graphic update rate (at least 30 Hz) on commodity PC hardware by utilizing traditional triangle-based rendering algorithms. In recent years, point-based rendering (PBR) has been shown to offer the potential to outperform the traditional triangle-based rendering in speed when it is applied to highly complex soft tissue cutting models. Nevertheless, the PBR algorithms are still limited in visual quality due to inherent contrast distortion. We propose an adaptive image contrast enhancement algorithm as a postprocessing module for PBR, providing high visual rendering quality as well as acceptable rendering efficiency. Our approach is based on a perceptible image quality technique with automatic parameter selection, resulting in a visual quality comparable to existing conventional PBR algorithms. Experimental results show that our adaptive image contrast enhancement algorithm produces encouraging results both visually and numerically compared to representative algorithms, and experiments conducted on the latest hardware demonstrate that the proposed PBR framework with the postprocessing module is superior to the conventional PBR algorithm and that the proposed contrast enhancement algorithm can be utilized in (or compatible with) various variants of the conventional PBR algorithm.

  5. Dynamic contrast enhanced ultrasound for therapy monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Hudson, John M. [Department of Medical Biophysics, University of Toronto, Toronto, ON (Canada); Williams, Ross [Imaging Research, Sunnybrook Research Institute, Toronto, ON (Canada); Tremblay-Darveau, Charles; Sheeran, Paul S. [Department of Medical Biophysics, University of Toronto, Toronto, ON (Canada); Milot, Laurent [Department of Medical Imaging, University of Toronto, Toronto, ON (Canada); Bjarnason, Georg A. [Department of Medical Oncology, University of Toronto, and Sunnybrook Odette Cancer Centre, Toronto, ON (Canada); Burns, Peter N., E-mail: burns@sri.utoronto.ca [Department of Medical Biophysics, University of Toronto, Toronto, ON (Canada); Imaging Research, Sunnybrook Research Institute, Toronto, ON (Canada); Department of Medical Imaging, University of Toronto, Toronto, ON (Canada)

    2015-09-15

    Quantitative imaging is a crucial component of the assessment of therapies that target the vasculature of angiogenic or inflamed tissue. Dynamic contrast-enhanced ultrasound (DCE-US) using microbubble contrast offers the advantages of being sensitive to perfusion, non-invasive, cost effective and well suited to repeated use at the bedside. Uniquely, it employs an agent that is truly intravascular. This papers reviews the principles and methodology of DCE-US, especially as applied to anti-angiogenic cancer therapies. Reproducibility is an important attribute of such a monitoring method: results are discussed. More recent technical advances in parametric and 3D DCE-US imaging are also summarised and illustrated.

  6. Bone mineral density measurements of the proximal femur from routine contrast-enhanced MDCT data sets correlate with dual-energy X-ray absorptiometry

    Energy Technology Data Exchange (ETDEWEB)

    Gruber, M. [Medical University of Vienna, Department of Radiology, Division of Neuroradiology and Musculoskeletal Radiology, Vienna (Austria); Bauer, J.S.; Dobritz, M.; Woertler, K.; Rummeny, E.J.; Baum, T. [Technische Universitaet Muenchen, Department of Radiology, Klinikum rechts der Isar, Munich (Germany); Beer, A.J. [Technische Universitaet Muenchen, Department of Nuclear Medicine, Munich (Germany); Wolf, P. [Technische Universitaet Muenchen, Institute for Medical Statistics and Epidemiology, Munich (Germany)

    2013-02-15

    To evaluate the utility of femoral bone mineral density (BMD) measurements in routine contrast-enhanced multi-detector computed tomography (ceMDCT) using dual-energy X-ray absorptiometry (DXA) as the reference standard. Forty-one patients (33 women, 8 men) underwent DXA measurement of the proximal femur. Subsequently, transverse sections of routine ceMDCT of these patients were used to measure BMD of the femoral head and femoral neck. The MDCT-to-DXA conversion equations for BMD and T-score were calculated using linear regression analysis. The conversion equations were applied to the MDCT data sets of 382 patients (120 women, 262 men) of whom 74 had osteoporotic fractures. A correlation coefficient of r = 0.84 (P < 0.05) was calculated for BMD{sub MDCT} values of the femoral head and DXA T-scores of the total proximal femur using the conversion equation T-score = 0.021 x BMD{sub MDCT} - 5.90. The correlation coefficient for the femoral neck was r = 0.79 (P < 0.05) with the conversion equation T-score = 0.016 x BMD{sub MDCT} - 4.28. Accordingly, converted T-scores for the femoral neck in patients with versus those without osteoporotic fractures were significantly different (female, -1.83 versus -1.47; male, -1.86 versus -1.47; P < 0.05). BMD measurements of the proximal femur were computed in routine contrast-enhanced MDCT and converted to DXA T-scores, which adequately differentiated patients with and without osteoporotic fractures. (orig.)

  7. Contrast enhanced ultrasound of sentinel lymph nodes

    Directory of Open Access Journals (Sweden)

    XinWu Cui

    2013-03-01

    Full Text Available Sentinel lymph nodes are the first lymph nodes in the region that receive lymphatic drainage from a primary tumor. The detection or exclusion of sentinel lymph node micrometastases is critical in the staging of cancer, especially breast cancer and melanoma because it directly affects patient’s prognosis and surgical management. Currently, intraoperative sentinel lymph node biopsies using blue dye and radioisotopes are the method of choice for the detection of sentinel lymph node with high identification rate. In contrast, conventional ultrasound is not capable of detecting sentinel lymph nodes in most cases. Contrast enhanced ultrasound with contrast specific imaging modes has been used for the evaluation and diagnostic work-up of peripherally located suspected lymphadenopathy. The method allows for real-time analysis of all vascular phases and the visualization of intranodal focal “avascular” areas that represent necrosis or deposits of neoplastic cells. In recent years, a number of animal and human studies showed that contrast enhanced ultrasound can be also used for the detection of sentinel lymph node, and may become a potential application in clinical routine. Several contrast agents have been used in those studies, including albumin solution, hydroxyethylated starch, SonoVue®, Sonazoid® and Definity®. This review summarizes the current knowledge about the use of ultrasound techniques in detection and evaluation of sentinel lymph node.

  8. Optimization of subcutaneous vein contrast enhancement

    Science.gov (United States)

    Zeman, Herbert D.; Lovhoiden, Gunnar; Deshmukh, Harshal

    2000-05-01

    A technique for enhancing the contrast of subcutaneous veins has been demonstrated. This techniques uses a near IR light source and one or more IR sensitive CCD TV cameras to produce a contrast enhanced image of the subcutaneous veins. This video image of the veins is projected back onto the patient's skin using a n LCD video projector. The use of an IR transmitting filter in front of the video cameras prevents any positive feedback from the visible light from the video projector from causing instabilities in the projected image. The demonstration contrast enhancing illuminator has been tested on adults and children, both Caucasian and African-American, and it enhances veins quite well in all cases. The most difficult cases are those where significant deposits of subcutaneous fat are present which make the veins invisible under normal room illumination. Recent attempts to see through fat using different IR wavelength bands and both linearly and circularly polarized light were unsuccessful. The key to seeing through fat turns out to be a very diffuse source of RI light. Results on adult and pediatric subjects are shown with this new IR light source.

  9. Quantitative contrast-enhanced optical coherence tomography

    Energy Technology Data Exchange (ETDEWEB)

    Winetraub, Yonatan; SoRelle, Elliott D. [Molecular Imaging Program at Stanford, Stanford University, 299 Campus Drive, Stanford, California 94305 (United States); Bio-X Program, Stanford University, 299 Campus Drive, Stanford, California 94305 (United States); Biophysics Program, Stanford University, 299 Campus Drive, Stanford, California 94305 (United States); Department of Structural Biology, Stanford University, 299 Campus Drive, Stanford, California 94305 (United States); Liba, Orly [Molecular Imaging Program at Stanford, Stanford University, 299 Campus Drive, Stanford, California 94305 (United States); Bio-X Program, Stanford University, 299 Campus Drive, Stanford, California 94305 (United States); Department of Structural Biology, Stanford University, 299 Campus Drive, Stanford, California 94305 (United States); Department of Electrical Engineering, Stanford University, 299 Campus Drive, Stanford, California 94305 (United States); Zerda, Adam de la [Molecular Imaging Program at Stanford, Stanford University, 299 Campus Drive, Stanford, California 94305 (United States); Bio-X Program, Stanford University, 299 Campus Drive, Stanford, California 94305 (United States); Biophysics Program, Stanford University, 299 Campus Drive, Stanford, California 94305 (United States); Department of Structural Biology, Stanford University, 299 Campus Drive, Stanford, California 94305 (United States); Department of Electrical Engineering, Stanford University, 299 Campus Drive, Stanford, California 94305 (United States)

    2016-01-11

    We have developed a model to accurately quantify the signals produced by exogenous scattering agents used for contrast-enhanced Optical Coherence Tomography (OCT). This model predicts distinct concentration-dependent signal trends that arise from the underlying physics of OCT detection. Accordingly, we show that real scattering particles can be described as simplified ideal scatterers with modified scattering intensity and concentration. The relation between OCT signal and particle concentration is approximately linear at concentrations lower than 0.8 particle per imaging voxel. However, at higher concentrations, interference effects cause signal to increase with a square root dependence on the number of particles within a voxel. Finally, high particle concentrations cause enough light attenuation to saturate the detected signal. Predictions were validated by comparison with measured OCT signals from gold nanorods (GNRs) prepared in water at concentrations ranging over five orders of magnitude (50 fM to 5 nM). In addition, we validated that our model accurately predicts the signal responses of GNRs in highly heterogeneous scattering environments including whole blood and living animals. By enabling particle quantification, this work provides a valuable tool for current and future contrast-enhanced in vivo OCT studies. More generally, the model described herein may inform the interpretation of detected signals in modalities that rely on coherence-based detection or are susceptible to interference effects.

  10. Fast contrast enhanced imaging with projection reconstruction

    Science.gov (United States)

    Peters, Dana Ceceilia

    The use of contrast agents has lead to great advances in magnetic resonance angiography (MRA). Here we present the first application of projection reconstruction to contrast enhanced MRA. In this research the limited angle projection reconstruction (PR) trajectory is implemented to acquire higher resolution images per unit time than with conventional Fourier transform (FT) imaging. It is well known that as FOV is reduced in conventional spin- warp imaging, higher resolution per unit time can be obtained, but aliasing may appear as a replication of outside material within the FOV. The limited angle PR acquisition also produces aliasing artifacts. This method produced artifacts which were unacceptable in X-ray CT but which appear to be tolerable in MR Angiography. Resolution throughout the FOV is determined by the projection readout resolution and not by the number of projections. As the number of projections is reduced, the resolution is unchanged, but low intensity artifacts appear. Here are presented the results of using limited angle PR in phantoms and contrast-enhanced angiograms of humans.

  11. Osteoblastic Metastases Mimickers on Contrast Enhanced CT

    Directory of Open Access Journals (Sweden)

    Fahad Al-Lhedan

    2017-01-01

    Full Text Available Secondary osseous involvement in lymphoma is more common compared to primary bone lymphoma. The finding of osseous lesion can be incidentally discovered during the course of the disease. However, osseous metastases are infrequently silent. Detection of osseous metastases is crucial for accurate staging and optimal treatment planning of lymphoma. The aim of imaging is to identify the presence and extent of osseous disease and to assess for possible complications such as pathological fracture of the load-bearing bones and cord compression if the lesion is spinal. We are presenting two patients with treated lymphoma who were in complete remission. On routine follow-up contrast enhanced CT, there were new osteoblastic lesions in the spine worrisome for metastases. Additional studies were performed for further evaluation of both of them which did not demonstrate any corresponding suspicious osseous lesion. The patients have a prior history of chronic venous occlusive thrombosis that resulted in collaterals formation. Contrast enhancement of the vertebral body marrow secondary to collaterals formation and venous flow through the vertebral venous plexus can mimic the appearance of spinal osteoblastic metastases.

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

    Energy Technology Data Exchange (ETDEWEB)

    Furlan, Alessandro, E-mail: furlana@upmc.edu [Department of Radiology, University of Pittsburgh Medical Center, Pittsburgh, PA 15213 (United States); Marin, Daniele [Department of Radiology, Duke University Medical Center, Durham, NC 27710 (United States); Department of Radiological Sciences, University of Rome-La Sapienza, Rome, 00161 (Italy); Cabassa, Paolo [Department of Radiology, Brescia University, Brescia (Italy); Taibbi, Adele [Department of Radiology, University of Palermo, Palermo, 90127 (Italy); Brunelli, Elena [Department of Radiology, Brescia University, Brescia (Italy); Agnello, Francesco; Lagalla, Roberto; Brancatelli, Giuseppe [Department of Radiology, University of Palermo, Palermo, 90127 (Italy)

    2012-09-15

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

  13. Is hepatotropic contrast enhanced MR a more effective method in differential diagnosis of hemangioma than multi-phase CT and unenhanced MR?

    Science.gov (United States)

    2011-01-01

    Background Cavernous hemangiomas are the most frequent neoplasms of the liver and in routine clinical practice they often need to be differentiated from malignant tumors and other benign focal lesions. The purpose of this study is to evaluate whether diagnostic accuracy of magnetic resonance imaging (MRI) of hepatic hemangiomas, showing atypical pattern on US, improves with the use of Gd-BOPTA in comparison with contrast-enhanced multi-phase computed tomography (CT). Methods 178 consecutive patients with ambiguous hepatic masses showing atypical hyperechoic pattern on grey-scale US, underwent unenhanced and contrast-enhanced multi-phase multi-detector CT and MR (1.5T) with the use of liver-specific contrast medium gadobenate dimeglumine (Gd-BOPTA). After intravenous contrast administration arterial (HAP), venous-portal (PVP), equilibrium phases (EP) both in CT and MR and additionally hepatobiliary phase (HBP) in MR were obtained. 398 lesions have been detected including 99 hemangiomas and 299 other lesions. Results In non-enhanced MDCT examination detection of hemangiomas was characterized by sensitivity of 76%, specificity of 90%, PPV of 71%, NPV of 92% and accuracy of 86%. Non-enhanced MR examination showed sensitivity of 98%, specificity of 99%, PPV of 99%, NPV of 99% and accuracy of 99%. After intravenous administration of contrast medium in MR the mentioned above parameters did not increase significantly. Conclusion Gd-BOPTA-enhanced MR in comparison with unenhanced MRI does not improve diagnostic accuracy in discriminating hemangiomas that show non-specific appearance in ultrasound examination. Unenhanced MR as a method of choice should directly follow US in course of diagnostic algorithm in differentiation of hemangiomas from other liver tumors. PMID:21504593

  14. Is hepatotropic contrast enhanced MR a more effective method in differential diagnosis of hemangioma than multi-phase CT and unenhanced MR?

    Directory of Open Access Journals (Sweden)

    Markiet Karolina

    2011-04-01

    Full Text Available Abstract Background Cavernous hemangiomas are the most frequent neoplasms of the liver and in routine clinical practice they often need to be differentiated from malignant tumors and other benign focal lesions. The purpose of this study is to evaluate whether diagnostic accuracy of magnetic resonance imaging (MRI of hepatic hemangiomas, showing atypical pattern on US, improves with the use of Gd-BOPTA in comparison with contrast-enhanced multi-phase computed tomography (CT. Methods 178 consecutive patients with ambiguous hepatic masses showing atypical hyperechoic pattern on grey-scale US, underwent unenhanced and contrast-enhanced multi-phase multi-detector CT and MR (1.5T with the use of liver-specific contrast medium gadobenate dimeglumine (Gd-BOPTA. After intravenous contrast administration arterial (HAP, venous-portal (PVP, equilibrium phases (EP both in CT and MR and additionally hepatobiliary phase (HBP in MR were obtained. 398 lesions have been detected including 99 hemangiomas and 299 other lesions. Results In non-enhanced MDCT examination detection of hemangiomas was characterized by sensitivity of 76%, specificity of 90%, PPV of 71%, NPV of 92% and accuracy of 86%. Non-enhanced MR examination showed sensitivity of 98%, specificity of 99%, PPV of 99%, NPV of 99% and accuracy of 99%. After intravenous administration of contrast medium in MR the mentioned above parameters did not increase significantly. Conclusion Gd-BOPTA-enhanced MR in comparison with unenhanced MRI does not improve diagnostic accuracy in discriminating hemangiomas that show non-specific appearance in ultrasound examination. Unenhanced MR as a method of choice should directly follow US in course of diagnostic algorithm in differentiation of hemangiomas from other liver tumors.

  15. Contrast Enhancement through Clustered Histogram Equalization

    Directory of Open Access Journals (Sweden)

    Shen-Chuan Tai

    2012-09-01

    Full Text Available This study proposed a contrast enhancement algorithm. Some methods enhance images depending on only the global or the local information, therefore it would cause over-enhancement usually and make the image look unnatural. The proposed method enhances image based on the global and local information. For the global part, we proposed mapping curves to find the new average, maximum and minimum intensity to try to suit the concept of Human Visual System (HVS for obtaining the better perceptual results. For the local part, we utilized fuzzy c-means clustering algorithm to group image and we can obtain the information of intensity distribution and pixel number from each group. Then we calculate weights according to the information and enhance images by Histogram Equalization (HE depending on the weights. The experiment results show that our method can enhance the contrast of image steadily and it causes over-enhancement with lower probability than other methods. The whole image not only looks natural but also shows detail texture more clearly after applying our method.

  16. Contrast-enhanced and targeted ultrasound.

    Science.gov (United States)

    Postema, Michiel; Gilja, Odd Helge

    2011-01-07

    Ultrasonic imaging is becoming the most popular medical imaging modality, owing to the low price per examination and its safety. However, blood is a poor scatterer of ultrasound waves at clinical diagnostic transmit frequencies. For perfusion imaging, markers have been designed to enhance the contrast in B-mode imaging. These so-called ultrasound contrast agents consist of microscopically small gas bubbles encapsulated in biodegradable shells. In this review, the physical principles of ultrasound contrast agent microbubble behavior and their adjustment for drug delivery including sonoporation are described. Furthermore, an outline of clinical imaging applications of contrast-enhanced ultrasound is given. It is a challenging task to quantify and predict which bubble phenomenon occurs under which acoustic condition, and how these phenomena may be utilized in ultrasonic imaging. Aided by high-speed photography, our improved understanding of encapsulated microbubble behavior will lead to more sophisticated detection and delivery techniques. More sophisticated methods use quantitative approaches to measure the amount and the time course of bolus or reperfusion curves, and have shown great promise in revealing effective tumor responses to anti-angiogenic drugs in humans before tumor shrinkage occurs. These are beginning to be accepted into clinical practice. In the long term, targeted microbubbles for molecular imaging and eventually for directed anti-tumor therapy are expected to be tested.

  17. Perceptual Contrast Enhancement with Dynamic Range Adjustment

    Science.gov (United States)

    Zhang, Hong; Li, Yuecheng; Chen, Hao; Yuan, Ding; Sun, Mingui

    2013-01-01

    Recent years, although great efforts have been made to improve its performance, few Histogram equalization (HE) methods take human visual perception (HVP) into account explicitly. The human visual system (HVS) is more sensitive to edges than brightness. This paper proposes to take use of this nature intuitively and develops a perceptual contrast enhancement approach with dynamic range adjustment through histogram modification. The use of perceptual contrast connects the image enhancement problem with the HVS. To pre-condition the input image before the HE procedure is implemented, a perceptual contrast map (PCM) is constructed based on the modified Difference of Gaussian (DOG) algorithm. As a result, the contrast of the image is sharpened and high frequency noise is suppressed. A modified Clipped Histogram Equalization (CHE) is also developed which improves visual quality by automatically detecting the dynamic range of the image with improved perceptual contrast. Experimental results show that the new HE algorithm outperforms several state-of-the-art algorithms in improving perceptual contrast and enhancing details. In addition, the new algorithm is simple to implement, making it suitable for real-time applications. PMID:24339452

  18. Contrast-enhanced and targeted ultrasound

    Institute of Scientific and Technical Information of China (English)

    Michiel Postema; Odd Helge Gilja

    2011-01-01

    Ultrasonic imaging is becoming the most popular medical imaging modality,owing to the low price per examination and its safety.However,blood is a poor scatterer of ultrasound waves at clinical diagnostic transmit frequencies.For perfusion imaging,markers have been designed to enhance the contrast in B-mode imaging.These so-called ultrasound contrast agents consist of microscopically small gas bubbles encapsulated in biodegradable shells.In this review,the physical principles of ultrasound contrast agent microbubble behavior and their adjustment for drug delivery including sonoporation are described.Furthermore,an outline of clinical imaging applications of contrast-enhanced ultrasound is given.It is a challenging task to quantify and predict which bubble phenomenon occurs under which acoustic condition,and how these phenomena may be utilized in ultrasonic imaging.Aided by high-speed photography,our improved understanding of encapsulated microbubble behavior will lead to more sophisticated detection and delivery techniques.More sophisticated methods use quantitative approaches to measure the amount and the time course of bolus or reperfusion curves,and have shown great promise in revealing effective tumor responses to anti-angiogenic drugs in humans before tumor shrinkage occurs.These are beginning to be accepted into clinical practice.In the long term,targeted microbubbles for molecular imaging and eventually for directed anti-tumor therapy are expected to be tested.

  19. Dynamic contrast enhanced MRI in prostate cancer

    Energy Technology Data Exchange (ETDEWEB)

    Alonzi, Roberto [Marie Curie Research Wing, Mount Vernon Cancer Centre, Rickmansworth Road, Northwood, Middlesex, HA6 2RN (United Kingdom)], E-mail: robertoalonzi@btinternet.com; Padhani, Anwar R. [Paul Strickland Scanner Centre, Mount Vernon Cancer Centre, Rickmansworth Road, Northwood, Middlesex, HA6 2RN (United Kingdom); Synarc Inc. 575 Market Street, San Francisco, CA 94105 (United States)], E-mail: anwar.padhani@paulstrickland-scannercentre.org.uk; Allen, Clare [Department of Imaging, University College Hospital, London, 235 Euston Road, NW1 2BU (United Kingdom)], E-mail: clare.allen@uclh.nhs.uk

    2007-09-15

    Angiogenesis is an integral part of benign prostatic hyperplasia (BPH), is associated with prostatic intraepithelial neoplasia (PIN) and is key to the growth and for metastasis of prostate cancer. Dynamic contrast enhanced magnetic resonance imaging (DCE-MRI) using small molecular weight gadolinium chelates enables non-invasive imaging characterization of tissue vascularity. Depending on the technique used, data reflecting tissue perfusion, microvessel permeability surface area product, and extracellular leakage space can be obtained. Two dynamic MRI techniques (T{sub 2}*-weighted or susceptibility based and T{sub 1}-weighted or relaxivity enhanced methods) for prostate gland evaluations are discussed in this review with reference to biological basis of observations, data acquisition and analysis methods, technical limitations and validation. Established clinical roles of T{sub 1}-weighted imaging evaluations will be discussed including lesion detection and localisation, for tumour staging and for the detection of suspected tumour recurrence. Limitations include inadequate lesion characterisation particularly differentiating prostatitis from cancer, and in distinguishing between BPH and central gland tumours.

  20. Contrast-enhanced ultrasound of the spleen.

    Science.gov (United States)

    Omar, Asha; Freeman, Simon

    2016-02-01

    Abnormalities in the spleen are less common than in most other abdominal organs. However, they will be regularly encountered by ultrasound practitioners, who carefully evaluate the spleen in their abdominal ultrasound studies. Conventional grey scale and Doppler ultrasound are frequently unable to characterise focal splenic abnormalities; even when clinical and laboratory information is added to the ultrasound findings, it is often not possible to make a definite diagnosis. Contrast-enhanced ultrasound (CEUS) is easy to perform, inexpensive, safe and will usually provide valuable additional information about splenic abnormalities, allowing a definitive or short differential diagnosis to be made. It also identifies those lesions that may require further imaging or biopsy, from those that can be safely dismissed or followed with interval ultrasound imaging. CEUS is also indicated in confirming the nature of suspected accessory splenic tissue and in selected patients with abdominal trauma. This article describes the CEUS examination technique, summarises the indications for CEUS and provides guidance on interpretation of the CEUS findings in splenic ultrasound.

  1. Contrast-enhanced ultrasound features of histologically proven focal nodular hyperplasia: diagnostic performance compared with contrast-enhanced CT

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Wei; Chen, Li-Da; Liu, Guang-Jian; Xu, Zuo-Feng; Xie, Xiao-Yan; Wang, Yan; Zhou, Lu-Yao [The First Affiliated Hospital of Sun Yat-Sen University Institute of Diagnostic and Interventional Ultrasound, Sun Yat-Sen University, Department of Medical Ultrasonics, Guangzhou (China); Lu, Ming-De [The First Affiliated Hospital of Sun Yat-Sen University Institute of Diagnostic and Interventional Ultrasound, Sun Yat-Sen University, Department of Medical Ultrasonics, Guangzhou (China); The First Affiliated Hospital of Sun Yat-Sen University, Department of Hepatobiliary Surgery, Guangzhou (China); Shen, Shun-Li [The First Affiliated Hospital of Sun Yat-Sen University, Department of Hepatobiliary Surgery, Guangzhou (China)

    2013-09-15

    To investigate and compare contrast-enhanced ultrasound (CEUS) in the characterisation of histologically proven focal nodular hyperplasia (FNH) with contrast-enhanced computed tomography (CECT). CEUS was performed in 85 patients with 85 histologically proven FNHs. Enhancement, centrifugal filling, spoke-wheel arteries, feeding artery and central scarring were reviewed and correlated with lesion size or liver background. Independent factors for predicting FNH from other focal liver lesions (FLLs) were evaluated. Forty-seven FLLs with CECT were randomly selected for comparison of diagnostic performance with CEUS. Centrifugal filling was more common (P = 0.002) and the significant predictor (P = 0.003) in FNHs {<=}3 cm. Lesion size or liver background has no significant influence on the detection rate of the spoke-wheel arteries and feeding artery (P > 0.05). Central scarring was found in 42.6 % of FNHs {>=}3 cm (P = 0.000). The area under the ROC curve, sensitivity and specificity showed no significant differences between CEUS and CECT (P > 0.05), except that the sensitivity of CEUS was better for reader 1 (P = 0.041). CEUS is valuable in characterising centrifugal filling signs or spoke wheels in small FNHs and should be employed as the first-line imaging technique for diagnosis of FNH. (orig.)

  2. Contrast-Enhanced Ultrasonography in Crohn's Disease Diagnostics.

    Science.gov (United States)

    Białecki, Marcin; Białecka, Agnieszka; Laskowska, Katarzyna; Liebert, Ariel; Kłopocka, Maria; Serafin, Zbigniew

    2015-06-01

    The chronic nature of Crohn's disease (CD) implicates necessity of multiple control assessments throughout patient's life. It is accepted that in patients with CD requiring disease monitoring, magnetic resonance enterography (MRE) and computed tomography enterography (CTE) are--apart from endoscopy--imaging studies of first choice. In practice, diagnostic imaging of patients with CD is troublesome, since MRE is an expensive and complicated study, and CTE exposes patients to high doses of ionizing radiation. Therefore, there is a need for new, both non-invasive and effective, methods of imaging in CD. Contrast-Enhanced Ultrasonography (CEUS) is a relatively new method using gas-filled microbubbles serving as contrast agent. It allows for detailed assessment of blood perfusion within intestine wall and peri-intestinal tissues, which enables detection and monitoring of inflammation and its qualitative assessment. The purpose of this paper is to describe CEUS examination technique and its clinical applications in patients with Crohn's disease.

  3. Contrast Enhanced MRI in the Diagnosis of HCC

    Directory of Open Access Journals (Sweden)

    Eric Niendorf

    2015-09-01

    Full Text Available Hepatocellular carcinoma (HCC is the 6th most common cancer worldwide. Imaging plays a critical role in HCC screening and diagnosis. Initial screening of patients at risk for HCC is performed with ultrasound. Confirmation of HCC can then be obtained by Computed Tomography (CT or Magnetic Resonance Imaging (MRI, due to the relatively high specificity of both techniques. This article will focus on reviewing MRI techniques for imaging HCC, felt by many to be the exam of choice for HCC diagnosis. MRI relies heavily upon the use of gadolinium-based contrast agents and while primarily extracellular gadolinium-based contrast agents are used, there is an emerging role of hepatobiliary contrast agents in HCC imaging. The use of other non-contrast enhanced MRI techniques for assessing HCC will also be discussed and these MRI strategies will be reviewed in the context of the pathophysiology of HCC to help understand the MR imaging appearance of HCC.

  4. Dynamic contrast-enhanced CT in patients with pancreatic cancer

    DEFF Research Database (Denmark)

    Lauridsen, Carsten Ammitzbøl; Eriksen, Rie Østbjerg; Strauch, Louise Søborg;

    2016-01-01

    tissue, compared with measurements in pancreatic tissue outside of tumor, or normal pancreatic tissue in control groups of healthy volunteers. The studies were heterogeneous in the number of patients enrolled and scan protocols. Perfusion parameters measured and analyzed by DCE-CT might be useful......The aim of this systematic review is to provide an overview of the use of Dynamic contrast-enhanced Computed Tomography (DCE-CT) in patients with pancreatic cancer. This study was composed according to the PRISMA guidelines 2009. The literature search was conducted in PubMed, Cochrane Library...... in the investigation of characteristic vascular patterns of pancreatic exocrine tumors. Further clinical studies are desired for investigating the potential of DCE-CT in pancreatic tumors. Keywords:...

  5. Radiofrequency ablation of liver cancer: early evaluation of therapeutic response with contrast-enhanced ultrasonography

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Dong Gil; Lim, Hyo K.; Lee, Won Jae; Kim, Seung Hoon; Kim, Min Ju; Kim, Seung Kwon; Jang, Kyung Mi; Lee, Ji Yeon; Lim, Jae Hoon [Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of)

    2004-09-15

    The early assessment of the therapeutic response after percutaneous radiofrequency (RF) ablation is important, in order to correctly decide whether further treatment is necessary. The residual unablated tumor is usually depicted on contrast-enhanced multiphase helical computed tomography (CT) as a focal enhancing structure during the arterial and portal venous phases. Contrast-enhanced color Doppler and power Doppler ultrasonography (US) have also been used to detect residual tumors. Contrast-enhanced gray-scale US, using a harmonic technology which has recently been introduced, allows for the detection of residual tumors after ablation, without any of the blooming or motion artifacts usually seen on contrast-enhanced color or power Doppler US. Based on our experience and reports in the literature, we consider that contrast-enhanced gray-scale harmonic US constitutes a reliable alternative to contrast-enhanced multiphase CT for the early evaluation of the therapeutic response to RF ablation for liver cancer. This technique was also useful in targeting any residual unablated tumors encountered during additional ablation.

  6. A new hardware-efficient algorithm and reconfigurable architecture for image contrast enhancement.

    Science.gov (United States)

    Huang, Shih-Chia; Chen, Wen-Chieh

    2014-10-01

    Contrast enhancement is crucial when generating high quality images for image processing applications, such as digital image or video photography, liquid crystal display processing, and medical image analysis. In order to achieve real-time performance for high-definition video applications, it is necessary to design efficient contrast enhancement hardware architecture to meet the needs of real-time processing. In this paper, we propose a novel hardware-oriented contrast enhancement algorithm which can be implemented effectively for hardware design. In order to be considered for hardware implementation, approximation techniques are proposed to reduce these complex computations during performance of the contrast enhancement algorithm. The proposed hardware-oriented contrast enhancement algorithm achieves good image quality by measuring the results of qualitative and quantitative analyzes. To decrease hardware cost and improve hardware utilization for real-time performance, a reduction in circuit area is proposed through use of parameter-controlled reconfigurable architecture. The experiment results show that the proposed hardware-oriented contrast enhancement algorithm can provide an average frame rate of 48.23 frames/s at high definition resolution 1920 × 1080.

  7. Contrast-enhanced ultrasonography to diagnose complicated acute cholecystitis.

    Science.gov (United States)

    Sagrini, Elisabetta; Pecorelli, Anna; Pettinari, Irene; Cucchetti, Alessandro; Stefanini, Federico; Bolondi, Luigi; Piscaglia, Fabio

    2016-02-01

    Gangrenous cholecystitis and perforation are severe complications of acute cholecystitis, which have a challenging preoperative diagnosis. Early identification allows better surgical management. Contrast-enhanced computed tomography (ceCT) is the current diagnostic gold standard. Contrast-enhanced ultrasonography (CEUS) is a promising tool for the diagnosis of gallbladder perforation, but data from the literature concerning efficacy are sparse. The aim of the study was to evaluate CEUS findings in pathologically proven complicated cholecystitis (gangrenous, perforated gallbladder, pericholecystic abscess). A total of 8 patients submitted to preoperative CEUS, and with subsequent proven acute complicated cholecystitis at surgical inspection and pathological analysis, were retrospectively identified. The final diagnosis was gangrenous/phlegmonous cholecystitis (n. 2), phlegmonous/ulcerative changes plus pericholecystic abscess (n. 2), perforated plus pericholecystic abscess (n. 3), or perforated plus pericholecystic biliary collection (n. 1). Conventional US findings revealed irregularly thickened gallbladder walls in all 8 patients, with vaguely defined walls in 7 patients, four of whom also had striated wall thickening. CEUS revealed irregular enhancing gallbladder walls in all patients. A distinct wall defect was seen in six patients, confirmed as gangrenous/phlegmonous cholecystitis at pathology in all six, and in four as perforation at macroscopic surgical inspection. CEUS is a non-invasive easily repeatable technique that can be performed at the bedside, and is able to accurately diagnose complicated/perforated cholecystitis. Despite the limited sample size in the present case series, CEUS appears as a promising tool for the management of patients with the clinical possibility of having an acute complicated cholecystitis.

  8. Contrast-enhanced microwave detection and treatment of breast cancer

    Science.gov (United States)

    Gao, Fuqiang

    Contrast agents and heating agents have been proposed for microwave breast tumor imaging and treatment, respectively. The dielectric properties of the tumor are altered with contrast agents or heating agents that locally accumulate in the tumor. The resulting change in dielectric properties of the tumor has the potential to enhance the sensitivity of microwave imaging of breast tumors and increase the efficiency and selectivity of microwave thermal therapy of breast tumors. This dissertation addresses several key challenges in contrast-enhanced microwave imaging and treatment of breast tumors. Carbon nanotubes (CNTs) have been shown to enhance both the relative permittivity and effective conductivity of the host medium, and are promising as theranostic (integrated therapeutic and diagnostic) agents. Thus, our properties characterization work focuses on CNT dispersions. We performed in vitro microwave dielectric properties and heating response characterization of dispersions of CNTs treated by different functionalization methods and identified a CNT formulation that is very promising as a microwave theranostic agent. Stable dispersions of CNTs with concentrations up to 20 mg/ml are obtained with this formulation, and the enhanced microwave properties of these dispersions are extraordinary compared to the control. We also conducted in vivo dielectric properties characterization of mouse tumors with intra-tumoral injections of CNT dispersions and confirmed that the presence of CNTs increases the dielectric properties of the tumor. In parallel, we developed a contrast-enhanced microwave breast tumor imaging algorithm using sparse reconstruction methods. We demonstrated that this algorithm accurately localizes small tumors in 3D numerical breast phantoms. We also demonstrated the experimental feasibility of this method using physical breast phantoms. Lastly, we studied the sensitivity of the distorted Born iterative method (DBIM) to initial guesses and developed a

  9. Analysis of bone mellow density in adults of domestic local area using multi-detector computed tomography: Focus on correlation about eating habits, lifestyle, physical features and social characteristics

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Tae Hui [Wonju Medical Center, Wonju (Korea, Republic of); Kim, Tae Hyung; So, Woon Young; Lim, Hei Gyeom [Kangwon National University Graduate School, Wonju (Korea, Republic of); Lim, Cheong Hwan [Hanseo University, Seosan (Korea, Republic of); Park, Myeong Hwan [Daegu Health College, Daegu (Korea, Republic of); Cheon, Myung Ki [Soongsil University, Seoul (Korea, Republic of)

    2016-12-15

    This study analyzed the correlation between BMD (bone mineral density) value calculated in the MDCT(multidetector computed tomography) and lifestyle, physical features and social characteristics. From July 15 2015 to June 6 2016, we converted from HU (hounsfield unit) value measured by using MDCT to T-score for BMD of 141 patients (male: 63, female: 78) in W medical center. We measured the 2nd, 3rd and 4th lumbar spine and analyzed the correlation between gender differences in BMD and lifestyle, physical features and social characteristics. Statistical significance was validated using independent sample T test with one way Anova. Gender BMD was confirmed that a statistically significant difference (p<0.05). BMD values decreased with increasing age but for the statistically men, there was no significant difference from 20s to 50s, it only showed a significant difference in 20s and 60s (p<0.001). For the statistically women, there was no significant difference from 20s to 40s. but since 50s BMD was decreased rapidly, which showed a significant difference(p<0.001). women showed significant differences for the menstruation and menopause, childbirth, alcohol, cereals and greasy food in bone mineral density (p<0.05) but there were no significant differences in men. The bone mineral density values calculated by the MDCT and lifestyle, physical features and social characteristics correlation analysis method is considered to be used as a basis for estimating the state in BMD and osteoporosis management.

  10. Quantitative Characterization of Inertial Confinement Fusion Capsules Using Phase Contrast Enhanced X-Ray Imaging

    Energy Technology Data Exchange (ETDEWEB)

    Kozioziemski, B J; Koch, J A; Barty, A; Martz, H E; Lee, W; Fezzaa, K

    2004-05-07

    Current designs for inertial confinement fusion capsules for the National Ignition Facility (NIF) consist of a solid deuterium-tritium (D-T) fuel layer inside of a copper doped beryllium capsule. Phase contrast enhanced x-ray imaging is shown to render the D-T layer visible inside the Be(Cu) capsule. Phase contrast imaging is experimentally demonstrated for several surrogate capsules and validates computational models. Polyimide and low density divinyl benzene foam capsules were imaged at the Advanced Photon Source synchrotron. The surrogates demonstrate that phase contrast enhanced imaging provides a method to characterize surfaces when absorption imaging cannot be used. Our computational models demonstrate that a rough surface can be accurately reproduced in phase contrast enhanced x-ray images.

  11. Acute complicated pyelonephritis: contrast-enhanced ultrasound.

    Science.gov (United States)

    Fontanilla, Teresa; Minaya, Javier; Cortés, Cristina; Hernando, Concepción González; Arangüena, Rafael Pérez; Arriaga, Jesús; Carmona, Maria Soledad; Alcolado, Ana

    2012-08-01

    Imaging is required if complication is suspected in acute pyelonephritis to assess the nature and extent of the lesions, and to detect underlying causes. The current imaging modality of choice in clinical practice is computed tomography. Because of associated radiation and potential nephrotoxicity, CEUS is an alternative that has been proven to be equally accurate in the detection of acute pyelonephritis renal lesions. The aims of this study of 48 patients are to describe in detail the CEUS findings in acute pyelonephritis, and to determine if abscess and focal pyelonephritis may be distinguished. Very characteristic morphologic and temporal patterns of enhancement are described. These allow differentiation of focal pyelonephritis from renal abscess, and detection of tiny suppurative foci within focal pyelonephritis. The detection of abscesses is important because follow-up in 25 patients revealed a longer clinical course. Typical pyelonephritis CEUS features permit distinction from other renal lesions. As a whole, CEUS is an excellent tool in the work-up of complicated acute pyelonephritis, so it may be considered as the imaging technique of choice in the evaluation and follow-up of these patients who frequently are very young, so as to minimise radiation exposure.

  12. Multi-detector computed tomography radiation doses in the follow ...

    African Journals Online (AJOL)

    2014-05-09

    May 9, 2014 ... more radiosensitive because of a higher rate of cell division in the former and radiosensitive. Page 1 of 4. Scan this QR code with your smart phone or mobile ... independent inspection bodies and dose parameters were.

  13. Pulmonary nodule follow-up : be careful with volumetry between contrast enhanced and unenhanced CT

    NARCIS (Netherlands)

    Mohamed Hoesein, Firdaus A; Bülbül, Metin; de Jong, Pim A

    2016-01-01

    Incident pulmonary nodules are a frequent finding on chest computed tomography (CT) of the lungs requiring follow-up. This case illustrates the importance of taking differences in CT scanning techniques (contrast versus non-contrast enhanced) into account. Comparing nodule size on unenhanced follow-

  14. Research of Multi Detectors of Neutron Spectrum in Mix Fields

    Institute of Scientific and Technical Information of China (English)

    LI; Wei; CHEN; Jun; WANG; Zhi-qiang; LI; Chun-juan; LIU; Yi-na; LUO; Hai-long; ZHANG; Wei-hua

    2013-01-01

    This neutron spectrometer can be used to measure neutron spectrum and neutron equivalent dosimetry.The range of neutron spectrum is thermal-20 MeV,and the range of neutron equivalent dosimetry is 1μSv·h-1-4 mSv·h-1.The sensor head of the neutron spectrum of multi detectors in mix fields houses five gas-filled sensors and a photo-scintillator column.There are two boron tri-fluoride(BF3)and three hydrogen

  15. A New Method of CT MedicalImages Contrast Enhancement

    Institute of Scientific and Technical Information of China (English)

    SUNFeng-rong; LIUWei; WANGChang-yu; MEILiang-mo

    2004-01-01

    A new method of contrast enhancement is proposed in the paper using multiscale edge representation of images, and is applied to the field of CT medical image processing. Comparing to the traditional Window technique, our method is adaptive and meets the demand of radiology clinics more better. The clinical experiment results show the practicality and the potential applied value of our methodin the field of CT medical images contrast enhancement.

  16. Motion correction of dynamic contrast enhanced MRI of the liver

    Science.gov (United States)

    Jansen, Mariëlle J. A.; Veldhuis, Wouter B.; van Leeuwen, Maarten S.; Pluim, Josien P. W.

    2017-02-01

    Motion correction of dynamic contrast enhanced magnetic resonance images (DCE-MRI) is a challenging task, due to changes in image appearance. In this study a groupwise registration, using a principle component analysis (PCA) based metric, is evaluated for clinical DCE MRI of the liver. The groupwise registration transforms the images to a common space, rather than to a reference volume as conventional pairwise methods do, and computes the similarity metric on all volumes simultaneously. This groupwise registration method is compared to a pairwise approach using a mutual information metric. Clinical DCE MRI of the abdomen of eight patients were included. Per patient one lesion in the liver was manually segmented in all temporal images (N=16). The registered images were compared for accuracy, spatial and temporal smoothness after transformation, and lesion volume change. Compared to a pairwise method or no registration, groupwise registration provided better alignment. In our recently started clinical study groupwise registered clinical DCE MRI of the abdomen of nine patients were scored by three radiologists. Groupwise registration increased the assessed quality of alignment. The gain in reading time for the radiologist was estimated to vary from no difference to almost a minute. A slight increase in reader confidence was also observed. Registration had no added value for images with little motion. In conclusion, the groupwise registration of DCE MR images results in better alignment than achieved by pairwise registration, which is beneficial for clinical assessment.

  17. Dynamic Contrast-Enhanced CT in Patients with Pancreatic Cancer

    Directory of Open Access Journals (Sweden)

    Rie Ø. Eriksen

    2016-09-01

    Full Text Available The aim of this systematic review is to provide an overview of the use of Dynamic Contrast-enhanced Computed Tomography (DCE-CT in patients with pancreatic cancer. This study was composed according to the PRISMA guidelines 2009. The literature search was conducted in PubMed, Cochrane Library, EMBASE, and Web of Science databases to identify all relevant publications. The QUADAS-2 tool was implemented to assess the risk of bias and applicability concerns of each included study. The initial literature search yielded 483 publications. Thirteen articles were included. Articles were categorized into three groups: nine articles concerning primary diagnosis or staging, one article about tumor response to treatment, and three articles regarding scan techniques. In exocrine pancreatic tumors, measurements of blood flow in eight studies and blood volume in seven studies were significantly lower in tumor tissue, compared with measurements in pancreatic tissue outside of tumor, or normal pancreatic tissue in control groups of healthy volunteers. The studies were heterogeneous in the number of patients enrolled and scan protocols. Perfusion parameters measured and analyzed by DCE-CT might be useful in the investigation of characteristic vascular patterns of exocrine pancreatic tumors. Further clinical studies are desired for investigating the potential of DCE-CT in pancreatic tumors.

  18. Temporal subtraction contrast-enhanced dedicated breast CT

    Science.gov (United States)

    Gazi, Peymon M.; Aminololama-Shakeri, Shadi; Yang, Kai; Boone, John M.

    2016-09-01

    The development of a framework of deformable image registration and segmentation for the purpose of temporal subtraction contrast-enhanced breast CT is described. An iterative histogram-based two-means clustering method was used for the segmentation. Dedicated breast CT images were segmented into background (air), adipose, fibroglandular and skin components. Fibroglandular tissue was classified as either normal or contrast-enhanced then divided into tiers for the purpose of categorizing degrees of contrast enhancement. A variant of the Demons deformable registration algorithm, intensity difference adaptive Demons (IDAD), was developed to correct for the large deformation forces that stemmed from contrast enhancement. In this application, the accuracy of the proposed method was evaluated in both mathematically-simulated and physically-acquired phantom images. Clinical usage and accuracy of the temporal subtraction framework was demonstrated using contrast-enhanced breast CT datasets from five patients. Registration performance was quantified using normalized cross correlation (NCC), symmetric uncertainty coefficient, normalized mutual information (NMI), mean square error (MSE) and target registration error (TRE). The proposed method outperformed conventional affine and other Demons variations in contrast enhanced breast CT image registration. In simulation studies, IDAD exhibited improvement in MSE (0-16%), NCC (0-6%), NMI (0-13%) and TRE (0-34%) compared to the conventional Demons approaches, depending on the size and intensity of the enhancing lesion. As lesion size and contrast enhancement levels increased, so did the improvement. The drop in the correlation between the pre- and post-contrast images for the largest enhancement levels in phantom studies is less than 1.2% (150 Hounsfield units). Registration error, measured by TRE, shows only submillimeter mismatches between the concordant anatomical target points in all patient studies. The algorithm was

  19. Evaluation of contrast-enhanced helical hydro-CT in staging gastric cancer

    Institute of Scientific and Technical Information of China (English)

    Wen-Zhou Wei; Jie-Ping Yu; Jun Li; Chang-Sheng Liu; Xiao-Hua Zheng

    2005-01-01

    AIM: To discuss the helical computed tomography (CT) characteristics of gastric cancer and evaluate the diagnostic value of contrast-enhanced helical hydro-CT (HHCT) in staging gastric cancer.METHODS: A total of 50 patients with gastric cancer were included in this study. The CT findings in them were retrospectively analyzed and correlated with pathologic findings at surgery. All patients were preoperatively imaged by plain and contrast-enhanced helical CT after orally ingesting 1 000-1 500 mL water. Peristalsis was minimized by intra-venous administration of spasmolytics.RESULTS: The foci of gastric cancer became more prominent in all the 50 patients and showed strong enhancement in contrast-enhanced HHCT. The tumor was located at the gastric cardia in 14 cases, at the gastric fundus in 3 cases, at the gastric body in 8 cases, at the gastric antrum in 4 cases, at the gastric fundus and the body in 8 cases, at the gastric body and antrum in 11 cases, and at three segments of the stomach in 2 cases.The CT features of gastric cancer were focal or diffuse mural thickening, soft tissue mass, cancerous ulcer, stenosis of stomach, infiltration to adjacent tissues, lymph node and distant metastases. Strong contrast enhancement of the gastric wall was closely related to gastric cancer. The accuracy rate of contrast-enhanced HHCT in staging gastric cancer was 86% (43/50). The detection rate of lymph node metastases by CT was 60% (12/20).CONCLUSION: Contrast-enhanced HHCT is a reliable method to diagnose and stage gastric cancer.

  20. Dynamic contrast enhanced magnetic resonance imaging in chronic Achilles tendinosis.

    Science.gov (United States)

    Gärdin, Anna; Brismar, Torkel B; Movin, Tomas; Shalabi, Adel

    2013-11-22

    Chronic Achilles tendinosis is a common problem. When evaluating and comparing different therapies there is a need for reliable imaging methods. Our aim was to evaluate if chronic Achilles tendinosis affects the dynamic contrast-enhancement in the tendon and its surroundings and if short-term eccentric calf-muscle training normalizes the dynamic contrast-enhancement. 20 patients with chronic Achilles tendinopathy were included. Median duration of symptoms was 31 months (range 6 to 120 months). Both Achilles tendons were examined with dynamic contrast enhanced MRI before and after a 12- week exercise programme of eccentric calf-muscle training. The dynamic MRI was evaluated in tendon, vessel and in fat ventrally of tendon. Area under the curve (AUC), time to peak of signal, signal increase per second (SI/s) and increase in signal between start and peak as a percentage (SI%) was calculated. Pain and performance were evaluated using a questionnaire. In the fat ventrally of the tendon, dynamic contrast enhancement was significantly higher in the symptomatic leg compared to the contralateral non-symptomatic leg before but not after treatment. Despite decreased pain and improved performance there was no significant change of dynamic contrast enhancement in symptomatic tendons after treatment. In Achilles tendinosis there is an increased contrast enhancement in the fat ventrally of the tendon. The lack of correlation with symptoms and the lack of significant changes in tendon contrast enhancement parameters do however indicate that dynamic enhanced MRI is currently not a useful method to evaluate chronic Achilles tendinosis.

  1. Evaluation of sacroiliitis: contrast-enhanced MRI with subtraction technique

    Energy Technology Data Exchange (ETDEWEB)

    Algin, Oktay; Gokalp, Gokhan; Baran, Bulent; Ocakoglu, Gokhan; Yazici, Zeynep [Uludag University, Medical Faculty, Department of Radiology, Gorukle, Bursa (Turkey)

    2009-10-15

    The purpose of the study was to investigate the diagnostic value of contrast-enhanced MRI using the subtraction technique in the detection of active sacroiliitis. Magnetic resonance imaging was performed in 8 asymptomatic volunteers and 50 patients with clinically suspected active sacroiliitis. On precontrast MR images, T1-weighted spin-echo images with and without fat saturation (T1WFS and T1W), STIR and 3D-FLASH images with fat saturation were obtained in the semicoronal plane using a 1.5 Tesla imager. Postcontrast MRI was performed using the same T1WFS sequence as before contrast injection for all volunteers and patients. Postcontrast images were subtracted from fat-suppressed precontrast images. Enhancement within the joint space and bone marrow was considered to demonstrate active sacroiliitis. In 50 patients (100 sacroiliac joints [SIJs]), 40 (76 SIJs) were considered to have active sacroiliitis based on MR images. Bone marrow edema was present in 33 patients (62 SIJs) on STIR images. Routine MRI allowed identification of contrast enhancement in SIJs on postcontrast T1WFS images in 31 patients (49 SIJs). Contrast enhancement was observed in 40 patients (76 SIJs) who were examined by MRI using the subtraction technique. Contrast enhancement was significantly more conspicuous on subtraction images than on non-subtracted postcontrast T1WFS images (Mann-Whitney U test, p<0.001). Contrast-enhanced MRI with subtraction technique may be useful for early detection of active sacroiliitis. (orig.)

  2. Congenital heart diseases: post-operative appearance on multi-detector CT - a pictorial essay

    Energy Technology Data Exchange (ETDEWEB)

    Tomasian, Anderanik; Malik, Sachin; Shamsa, Kamran; Krishnam, Mayil S. [UCLA Medical Center, Department of Radiological Science, Los Angeles, CA (United States)

    2009-12-15

    Echocardiography is considered as an initial imaging modality of choice in patients with congenital heart disease (CHD), and magnetic resonance (MR) imaging is preferred for detailed functional information. Multi-detector computed tomography (CT) plays an important role in clinical practice in assessing post-operative morphological and functional information of patients with complex CHD when echocardiography and MR imaging are not contributory. Radiologists should understand and become familiar with the complex morphology and physiology of CHD, as well as with various palliative and corrective surgical procedures performed in these patients, to obtain CT angiograms with diagnostic quality and promptly recognise imaging features of normal post-operative anatomy and complications of these complex surgeries. (orig.)

  3. Toroid cavity/coil NMR multi-detector

    Science.gov (United States)

    Gerald, II, Rex E.; Meadows, Alexander D.; Gregar, Joseph S.; Rathke, Jerome W.

    2007-09-18

    An analytical device for rapid, non-invasive nuclear magnetic resonance (NMR) spectroscopy of multiple samples using a single spectrometer is provided. A modified toroid cavity/coil detector (TCD), and methods for conducting the simultaneous acquisition of NMR data for multiple samples including a protocol for testing NMR multi-detectors are provided. One embodiment includes a plurality of LC resonant circuits including spatially separated toroid coil inductors, each toroid coil inductor enveloping its corresponding sample volume, and tuned to resonate at a predefined frequency using a variable capacitor. The toroid coil is formed into a loop, where both ends of the toroid coil are brought into coincidence. Another embodiment includes multiple micro Helmholtz coils arranged on a circular perimeter concentric with a central conductor of the toroid cavity.

  4. Enhanced security for multi-detector quantum random number generators

    Science.gov (United States)

    Marangon, Davide G.; Vallone, Giuseppe; Zanforlin, Ugo; Villoresi, Paolo

    2016-11-01

    Quantum random number generators (QRNG) represent an advanced solution for randomness generation, which is essential in every cryptographic application. In this context, integrated arrays of single-photon detectors have promising applications as QRNGs based on the spatial detection of photons. For the employment of QRNGs in cryptography, it is necessary to have efficient methods to evaluate the so-called quantum min-entropy that corresponds to the amount of the true extractable quantum randomness from the QRNG. Here, we present an efficient method that allows the estimation of the quantum min-entropy for a multi-detector QRNG. In particular, we consider a scenario in which an attacker can control the efficiency of the detectors and knows the emitted number of photons. Eventually, we apply the method to a QRNG with 103 detectors.

  5. Patterns of contrast enhancement in the brain and meninges.

    Science.gov (United States)

    Smirniotopoulos, James G; Murphy, Frances M; Rushing, Elizabeth J; Rees, John H; Schroeder, Jason W

    2007-01-01

    Contrast material enhancement for cross-sectional imaging has been used since the mid 1970s for computed tomography and the mid 1980s for magnetic resonance imaging. Knowledge of the patterns and mechanisms of contrast enhancement facilitate radiologic differential diagnosis. Brain and spinal cord enhancement is related to both intravascular and extravascular contrast material. Extraaxial enhancing lesions include primary neoplasms (meningioma), granulomatous disease (sarcoid), and metastases (which often manifest as mass lesions). Linear pachymeningeal (dura-arachnoid) enhancement occurs after surgery and with spontaneous intracranial hypotension. Leptomeningeal (pia-arachnoid) enhancement is present in meningitis and meningoencephalitis. Superficial gyral enhancement is seen after reperfusion in cerebral ischemia, during the healing phase of cerebral infarction, and with encephalitis. Nodular subcortical lesions are typical for hematogenous dissemination and may be neoplastic (metastases) or infectious (septic emboli). Deeper lesions may form rings or affect the ventricular margins. Ring enhancement that is smooth and thin is typical of an organizing abscess, whereas thick irregular rings suggest a necrotic neoplasm. Some low-grade neoplasms are "fluid-secreting," and they may form heterogeneously enhancing lesions with an incomplete ring sign as well as the classic "cyst-with-nodule" morphology. Demyelinating lesions, including both classic multiple sclerosis and tumefactive demyelination, may also create an open ring or incomplete ring sign. Thick and irregular periventricular enhancement is typical for primary central nervous system lymphoma. Thin enhancement of the ventricular margin occurs with infectious ependymitis. Understanding the classic patterns of lesion enhancement--and the radiologic-pathologic mechanisms that produce them--can improve image assessment and differential diagnosis.

  6. Contrast Enhancement of Radiographs Using Shift Invariant Wavelet Transform

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    A novel approach using shift invariant wavelet transform is presented for the contrast enhancement of radiographs. By exploiting cross-scale correlation among wavelet coefficients, edge information of radiographic images is extracted and protected, while noise is smoothed out in the wavelet domain. Radiographs are then reconstructed from the transform coefficients modified at multi-scales by nonlinear enhancement operator. The method can achieve effectively contrast enhancement and edge-preserved denoising simultaneously, yet it is capable of giving visually distinct images and offering considerable benefits in medical diagnosis.

  7. Dynamic contrast-enhanced endoscopic ultrasound: A quantification method

    Science.gov (United States)

    Dietrich, Christoph F.; Dong, Yi; Froehlich, Eckhart; Hocke, Michael

    2017-01-01

    Dynamic contrast-enhanced ultrasound (DCE-US) has been recently standardized by guidelines and recommendations. The European Federation of Societies for US in Medicine and Biology position paper describes the use for DCE-US. Comparatively, little is known about the use of contrast-enhanced endoscopic US (CE-EUS). This current paper reviews and discusses the clinical use of CE-EUS and DCE-US. The most important clinical use of DCE-US is the prediction of tumor response to new drugs against vascular angioneogenesis. PMID:28218195

  8. Value of contrast-enhanced ultrasound in rheumatic disease.

    Science.gov (United States)

    Klauser, Andrea Sabine

    2005-12-01

    Ultrasound (US) is a useful tool in the assessment of rheumatic disease. It permits assessment of early erosive changes and vascularity detection in synovial proliferation, caused by inflammatory activity by using colour/power Doppler US (CDUS/PDUS). In the detection of slow flow and flow in small vessels, the CDUS/PDUS technique is limited. Contrast enhanced US can improve the detection of inflammatory vascularity but is not yet included in routine diagnosis of this condition. However, contrast enhanced US shows promising results in diagnosis, assessment of disease activity and follow up of inflammatory rheumatic diseases.

  9. Clinical value of dynamic 3-dimensional contrast-enhanced ultrasound imaging for the assessment of hepatocellular carcinoma ablation.

    Science.gov (United States)

    Wang, Yandong; Jing, Xiang; Ding, Jianmin

    2016-01-01

    The aim of the study was to investigate the performance of dynamic 3-dimensional contrast-enhanced ultrasound (3D-CEUS) on assessment of efficacy of local ablation therapy of hepatocellular carcinoma (HCC) with contrast-enhanced computed tomography (CT) as reference standard. Eighty-nine HCC lesions from 75 patients undergoing ultrasound-guided percutaneous thermal ablation or chemical ablation were studied by both dynamic 3D-CEUS and contrast-enhanced CT 1month after ablation. Imaging results from two imaging modalities were evaluated independently by experienced readers to determine whether the treated lesions were ablated incompletely (residual unablated tumor) or completely. Sensitivity, specificity, positive and negative predictive values, and accuracy to identify incomplete ablation were calculated for dynamic 3D-CEUS imaging with contrast-enhanced CT as reference standard. Contrast-enhanced CT reported that 80.9% (72/89) of all the treated lesions were completely ablated and 19.1% (17/89) were incompletely ablated. The dynamic 3D-CEUS identified 82.0% (73/89) and 18.0% (16/89) of lesions as completely and incompletely ablated, respectively. With contrast-enhanced CT as the reference standard, the sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of dynamic 3D-CEUS for identifying residual unablated tumor were 88.2% (15/17), 98.6% (71/72), 93.8% (15/16), 97.3% (71/73), and 96.6% (86/89), respectively. The Kappa value for identifying residual unablated tumor between contrast-enhanced CT and dynamic 3D-CEUS was 0.89. Dynamic 3D-CEUS is highly consistent with contrast-enhanced CT in assessment of efficacy of HCC ablation and has potential to serve as an alternative to contrast-enhanced CT in the follow-up assessment after HCC ablation. Published by Elsevier Inc.

  10. Novel contrast-enhanced ultrasound imaging in prostate cancer

    NARCIS (Netherlands)

    Smeenge, M.; Mischi, M.; Laguna Pes, M.P.; de la Rosette, J.J.M.C.H.; Wijkstra, H.

    2011-01-01

    The purposes of this paper were to present the current status of contrast-enhanced transrectal ultrasound imaging and to discuss the latest achievements and techniques now under preclinical testing. Although grayscale transrectal ultrasound is the standard method for prostate imaging, it lacks accur

  11. Sentinel node detection in melanomas using contrast-enhanced ultrasound

    DEFF Research Database (Denmark)

    Nielsen, K. Rue; Klyver, H.; Chakera, A. Hougaard;

    2009-01-01

    BACKGROUND: Sentinel node (SN) biopsy has proven to be a useful clinical method based on the combination of radionuclide tracer principles and the dye technique. Contrast-enhanced ultrasound (CEUS) has been used successfully for detection of SN in animals, but the use of CEUS has not been reported...

  12. Hepatocellular carcinoma: perfusion quantification with dynamic contrast-enhanced MRI

    NARCIS (Netherlands)

    Taouli, B.; Johnson, R.S.; Hajdu, C.H.; Oei, M.T.H.; Merad, M.; Yee, H.; Rusinek, H.

    2013-01-01

    The objective of our study was to report our initial experience with dynamic contrast-enhanced MRI (DCE-MRI) for perfusion quantification of hepatocellular carcinoma (HCC) and surrounding liver.DCE-MRI of the liver was prospectively performed on 31 patients with HCC (male-female ratio, 26:5; mean ag

  13. Can abdominal multi-detector CT diagnose spinal osteoporosis?

    Energy Technology Data Exchange (ETDEWEB)

    Papadakis, Antonios E.; Damilakis, John [University of Crete, Department of Medical Physics, Faculty of Medicine, P.O. Box 2208, Iraklion, Crete (Greece); Karantanas, Apostolos H. [University of Crete, Department of Radiology, Faculty of Medicine, P.O. Box 2208, Iraklion, Crete (Greece); Papadokostakis, Giorgos [University Hospital of Heraklion, Department of Orthopedics, Faculty of Medicine, P.O. Box 2208, Iraklion, Crete (Greece); Petinellis, Effie [University Hospital of Heraklion, Department of Radiotherapy, Faculty of Medicine, P.O. Box 2208, Iraklion, Crete (Greece)

    2009-01-15

    The aim of this study was to (1) generate quantitative CT (QCT) densitometric data based on routine abdominal multi-detector (MDCT) examinations and (2) investigate whether these data can be used to differentiate osteoporotic from healthy females. Twenty-five female patients (group A) with a history of radiotherapy were examined both with routine abdominal MDCT and standard QCT to generate a MDCT-to-QCT conversion equation. Twenty-one osteoporotic (group B) and 23 healthy female patients (group C) were also recruited in the study. Patients of groups B and C underwent routine abdominal MDCT examination for various clinical indications. Mean bone mineral density (BMD) in patients of group A was 103.4 mg/ml {+-} 32.8 with routine abdominal MDCT and 91.0 mg/ml {+-}28.5 with QCT. Quantitative CT BMD{sub QCT} values for patients in groups B and C were calculated utilizing the BMD{sub MDCT} values derived from routine abdominal MDCT data sets and the MDCT to QCT conversion equation: BMD{sub QCT}=0.78. BMD{sub MDCT}+10.13. The calculated QCT densitometric data adequately differentiated osteoporotic from healthy females (area under ROC curve 0.828, p=0.05). In conclusion, this study showed that in a group of female patients, QCT data derived from routine abdominal MDCT examinations discriminated osteoporotic from healthy subjects. (orig.)

  14. Pulmonary Vascular Tree Segmentation from Contrast-Enhanced CT Images

    CERN Document Server

    Helmberger, M; Pienn, M; Balint, Z; Olschewski, A; Bischof, H

    2013-01-01

    We present a pulmonary vessel segmentation algorithm, which is fast, fully automatic and robust. It uses a coarse segmentation of the airway tree and a left and right lung labeled volume to restrict a vessel enhancement filter, based on an offset medialness function, to the lungs. We show the application of our algorithm on contrast-enhanced CT images, where we derive a clinical parameter to detect pulmonary hypertension (PH) in patients. Results on a dataset of 24 patients show that quantitative indices derived from the segmentation are applicable to distinguish patients with and without PH. Further work-in-progress results are shown on the VESSEL12 challenge dataset, which is composed of non-contrast-enhanced scans, where we range in the midfield of participating contestants.

  15. Contrast-enhanced endoscopic ultrasonography: advance and current status

    Energy Technology Data Exchange (ETDEWEB)

    Jang, Sung Il [Dept. of Internal Medicine, Kangnam Sacred Heart Hospital, Hallym University College of Medicine, Seoul (Korea, Republic of); Lee, Dong Ki [Dept. of Internal Medicine, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul (Korea, Republic of)

    2014-10-15

    Endoscopic ultrasonography (EUS) technology has undergone a great deal of progress along with the color and power Doppler imaging, three-dimensional imaging, electronic scanning, tissue harmonic imaging, and elastography, and one of the most important developments is the ability to acquire contrast-enhanced images. The blood flow in small vessels and the parenchymal microvasculature of the target lesion can be observed non-invasively by contrast-enhanced EUS (CE-EUS). Through a hemodynamic analysis, CE-EUS permits the diagnosis of various gastrointestinal diseases and differential diagnoses between benign and malignant tumors. Recently, mechanical innovations and the development of contrast agents have increased the use of CE-EUS in the diagnostic field, as well as for the assessment of the efficacy of therapeutic agents. The advances in and the current status of CE-EUS are discussed in this review.

  16. Contrast-enhanced endoscopic ultrasonography: advance and current status

    Directory of Open Access Journals (Sweden)

    Sung Ill Jang

    2014-07-01

    Full Text Available Endoscopic ultrasonography (EUS technology has undergone a great deal of progress along with the color and power Doppler imaging, three-dimensional imaging, electronic scanning, tissue harmonic imaging, and elastography, and one of the most important developments is the ability to acquire contrast-enhanced images. The blood flow in small vessels and the parenchymal microvasculature of the target lesion can be observed non-invasively by contrast-enhanced EUS (CE-EUS. Through a hemodynamic analysis, CE-EUS permits the diagnosis of various gastrointestinal diseases and differential diagnoses between benign and malignant tumors. Recently, mechanical innovations and the development of contrast agents have increased the use of CE-EUS in the diagnostic field, as well as for the assessment of the efficacy of therapeutic agents. The advances in and the current status of CE-EUS are discussed in this review.

  17. A Review of Image Contrast Enhancement Methods and Techniques

    Directory of Open Access Journals (Sweden)

    G. Maragatham

    2015-02-01

    Full Text Available In this study we aim to provide a survey of existing enhancement techniques with their descriptions and present a detailed analysis of them. Since most of the images while capturing are affected by weather, poor lighting and the acquiring device itself, they suffer from poor contrast. Sufficient Contrast in an image makes an object distinguishable from the other objects and the background. Contrast enhancement improves the quality of images for human observer by expanding the dynamic range of input gray level. A plethora enhancement techniques have though emerged, none of them deem to be a universal one, thus becoming selective in application. In such a scenario, it has become imperative to provide a comprehensive survey of these contrast enhancement techniques used in digital image processing.

  18. Non-contrast-enhanced MR angiography of the abdomen

    Energy Technology Data Exchange (ETDEWEB)

    Miyazaki, Mitsue, E-mail: mmiyazaki@tmriusa.com [Toshiba Medical Research Institute, USA, 706N. Deerpath Dr., Vernon Hills, IL 60061 (United States); Isoda, Hiroyoshi [Toshiba Medical Research Institute, USA, 706N. Deerpath Dr., Vernon Hills, IL 60061 (United States); Department of Diagnostic Imaging and Nuclear Medicine, Kyoto University, Kyoto (Japan)

    2011-10-15

    Non-contrast-enhanced magnetic resonance angiography (MRA) techniques have experienced a resurgence of interest in the MR community, in part because of safety concerns related to the possible link between gadolinium-based contrast agents and nephrogenic systemic fibrosis (NSF). In abdominal MRA, NSF is of particular concern, given that many of the patients may have renal disease. After introducing various non-contrast-enhanced MRA techniques, this article focuses on MRA applications in the abdomen, specifically the renal arteries and portal and hepatic veins. Developments on the horizon are discussed, including techniques that provide standardization of renal artery imaging, challenges in imaging of the hepatic arteries, and further advancement at 3 T.

  19. Contrast-enhanced photoacoustic tomography of human joints

    Science.gov (United States)

    Tian, Chao; Keswani, Rahul K.; Gandikota, Girish; Rosania, Gus R.; Wang, Xueding

    2016-03-01

    Photoacoustic tomography (PAT) provides a unique tool to diagnose inflammatory arthritis. However, the specificity and sensitivity of PAT based on endogenous contrasts is limited. The development of contrast enhanced PAT imaging modalities in combination with small molecule contrast agents could lead to improvements in diagnosis and treatment of joint disease. Accordingly, we adapted and tested a PAT clinical imaging system for imaging the human joints, in combination with a novel PAT contrast agent derived from an FDA-approved small molecule drug. Imaging results based on a photoacoustic and ultrasound (PA/US) dual-modality system revealed that this contrast-enhanced PAT imaging system may offer additional information beyond single-modality PA or US imaging system, for the imaging, diagnosis and assessment of inflammatory arthritis.

  20. Contrast enhanced exposure strategy in multi-beam mask writing

    Science.gov (United States)

    Belic, Nikola; Hofmann, Ulrich; Klikovits, Jan; Martens, Stephan

    2013-03-01

    Since multi electron beam exposure has become a serious contender for next generation mask making, proximity- and process effect corrections (PEC) need to be adapted to this technology. With feature sizes in the order of the short-range blurs (resist and tool), contrast enhancements need to be combined with standard linearity corrections. Different PEC strategies are reviewed and compared with respect to their suitability for multi-beam exposure. This analysis recommends a hybrid approach that combines the benefits of shape- and dose PEC and is optimally applicable for multibeam exposure. Exposure results on the proof-of-concept 50keV electron multi-beam mask exposure tool (eMET POC) and a standard 50 kV vector shaped beam tool (VSB) are shown to verify that the combined PEC with overdose contrast enhancement covers the whole pattern range from isolated to opaque.

  1. Ultrasonographic contrast-enhanced study of sicca syndrome

    Energy Technology Data Exchange (ETDEWEB)

    Giuseppetti, Gian Marco [Institute of Radiology, University School of Medicine, Umberto I Hospital, Via Conca 1, Ancona (Italy)]. E-mail: gm.giuseppetti@ao-umbertoprimo.marche.it; Argalia, Giulio [Institute of Radiology, University School of Medicine, Umberto I Hospital, Via Conca 1, Ancona (Italy); Salera, Diego [Institute of Radiology, University School of Medicine, Umberto I Hospital, Via Conca 1, Ancona (Italy); Ranaldi, Roberto [Institute of Pathological Anatomy and Histopathology, University School of Medicine, Umberto I Hospital, Ancona (Italy); Danieli, Giovanna [Institute of Internal Medicine, University School of Medicine, Umberto I Hospital, Ancona (Italy); Cappelli, Marida [Institute of Internal Medicine, University School of Medicine, Umberto I Hospital, Ancona (Italy)

    2005-05-01

    Objective: To assess the ability of US contrast-enhanced time-intensity curves to depict the changes connected with sicca syndrome, a fairly common condition that is often associated with autoimmune disorders such as Sjogren's syndrome or other diseases. Diagnostic criteria are complex and controversial and although no single test can be considered the gold standard, salivary gland scintigraphy and biopsy are reliable diagnostic methods. Materials and methods: Sixty consecutive patients with sicca syndrome, 40 of whom had primary (n = 23) or secondary (n = 17) Sjogren's syndrome and 20 had non-Sjogren's sicca syndrome, selected according to European Community Study Group diagnostic criteria for Sjogren's syndrome and subjected to contrast-enhanced US imaging of the parotids using a second-generation contrast agent with analysis of time-intensity curves at rest and during salivary stimulation, Tc99m salivary gland scintigraphy and labial gland biopsy. Results: In the 40 Sjogren's patients, US enhancement values were significantly lower (P < 0.0001 and P < 0.00003, respectively) than in the 20 non-Sjogren's patients both at rest and during stimulation. In the 23 subjects with the primary syndrome, values during stimulation were significantly lower than in the 17 subjects with the secondary syndrome (P < 0.0006), whereas at rest differences were not significant. Contrast-enhanced US imaging allowed to discriminate Sjogren's from non-Sjogren's sicca patients with 87.5% sensitivity, 85% specificity and 86.7% accuracy and the primary from the secondary syndrome with 78.2% sensitivity, 70.5% specificity and 75% accuracy. Interestingly, in eight patients with the primary syndrome, i.e. those with the more severe gland involvement, enhancement values were lower during stimulation than at rest. Conclusion: Preliminary results indicate that contrast-enhanced US imaging can provide useful information on sicca characterisation and

  2. Automatic Contrast Enhancement of Brain MR Images Using Hierarchical Correlation Histogram Analysis.

    Science.gov (United States)

    Chen, Chiao-Min; Chen, Chih-Cheng; Wu, Ming-Chi; Horng, Gwoboa; Wu, Hsien-Chu; Hsueh, Shih-Hua; Ho, His-Yun

    Parkinson's disease is a progressive neurodegenerative disorder that has a higher probability of occurrence in middle-aged and older adults than in the young. With the use of a computer-aided diagnosis (CAD) system, abnormal cell regions can be identified, and this identification can help medical personnel to evaluate the chance of disease. This study proposes a hierarchical correlation histogram analysis based on the grayscale distribution degree of pixel intensity by constructing a correlation histogram, that can improves the adaptive contrast enhancement for specific objects. The proposed method produces significant results during contrast enhancement preprocessing and facilitates subsequent CAD processes, thereby reducing recognition time and improving accuracy. The experimental results show that the proposed method is superior to existing methods by using two estimation image quantitative methods of PSNR and average gradient values. Furthermore, the edge information pertaining to specific cells can effectively increase the accuracy of the results.

  3. Contrast enhancement pattern in MR imaging of acute cerebral infarction

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jong Deok; Cho, Mee Young; Lee, Chae Guk; Song, Dong Hoon [Inje University College of Medicine, Pusan (Korea, Republic of)

    1994-08-15

    To present the enhancement pattern of acute cerebral or cerebellar cortical infarctions aged 1-3 days on MR. Contrast-enhanced MR images of 26 patients with acute cerebral or cerebellar ischemic events were retrospectively reviewed. MR was performed within 3 days after ictus. Contrast enhancement in the area of infarction was observed in 61.5% (16/26) on MR. Of these 50% (13/26) showed non-parenchymal enhancement (NPE) representing either vascular or leptomeningeal enhancement, 7.7% (2/26) showed parenchymal enhancement (PE), and 2.8% (1/26) showed both NPE and PE. The earliest enhancement was seen in images obtained 12 hours after the onset of symptoms and appeared as NPE. One patient showed NPE without apparent high signal intensity at the corresponding area on T2-weighted images. In 38.5% (10/26), there was no enhancement. Contrast-enhanced MR imaging may be needed in acute ischemic infarction, because NPE may be seen as the earliest MR finding of acute cortical infraction aged 1-3 days.

  4. Facial nerve palsy: Evaluation by contrast-enhanced MR imaging

    Energy Technology Data Exchange (ETDEWEB)

    Kinoshita, T.; Ishii, K.; Okitsu, T.; Okudera, T.; Ogawa, T

    2001-11-01

    AIM: The purpose of this study was to investigate the value of contrast-enhanced magnetic resonance (MR) imaging in patients with peripheral facial nerve palsy. MATERIALS AND METHODS: MR imaging was performed in 147 patients with facial nerve palsy, using a 1.0 T unit. All of 147 patients were evaluated by contrast-enhanced MR imaging and the pattern of enhancement was compared with that in 300 control subjects evaluated for suspected acoustic neurinoma. RESULTS: The intrameatal and labyrinthine segments of the normal facial nerve did not show enhancement, whereas enhancement of the distal intrameatal segment and the labyrinthine segment was respectively found in 67% and 43% of patients with Bell's palsy. The geniculate ganglion or the tympanic-mastoid segment was enhanced in 21% of normal controls versus 91% of patients with Bell's palsy. Abnormal enhancement of the non-paralyzed facial nerve was found in a patient with bilateral temporal bone fracture. CONCLUSION: Enhancement of the distal intrameatal and labyrinthine segments is specific for facial nerve palsy. Contrast-enhanced MR imaging can reveal inflammatory facial nerve lesions and traumatic nerve injury, including clinically silent damage in trauma. Kinoshita T. et al. (2001)

  5. Cranial CT revisited: do we really need contrast enhancement?

    Energy Technology Data Exchange (ETDEWEB)

    Demaerel, P.; Buelens, C.; Wilms, G.; Baert, A.L. [Department of Radiology, University Hospitals, Leuven (Belgium)

    1998-10-01

    The aim of this study was to define guidelines for intravenous contrast administration in cranial CT, as currently there are no recent guidelines based on a large series of patients. In 1900 consecutive patients (1480 adults and 420 children) pre- and post-contrast scan was analysed in order to assess the contribution of contrast enhancement to the diagnosis. The findings were grouped according to whether abnormalities were seen on the pre- and/or post-contrast scan, or whether no abnormalities were seen at all. Sensitivity, specificity, positive predictive value, negative predictive value and accurracy of a pre-contrast scan were used to determine validity. Intravenous contrast enhancement only contributes to the diagnosis if a suspicious abnormality is seen on the unenhanced scan or in the appropriate clinical setting (33.6 %). In the remaining patients (65.6 %) there is no diagnostic contribution, except for a small number of abnormalities (0.8 %). These are often anatomical variants and have no therapeutic impact. The number of contrast-enhanced cranial CT examinations can significantly be reduced by using four general guidelines for contrast administration resulting in considerable cost savings without affecting the quality of service to the patient. These guidelines are defined by the clinical findings/presentation or by the findings on the unenhanced scan. The number of contrast-related complications will be reduced, which may have medicolegal implications. These guidelines can be applied in any radiology department. (orig.) (orig.) With 2 tabs., 13 refs.

  6. Visual Contrast Enhancement Algorithm Based on Histogram Equalization

    Directory of Open Access Journals (Sweden)

    Chih-Chung Ting

    2015-07-01

    Full Text Available Image enhancement techniques primarily improve the contrast of an image to lend it a better appearance. One of the popular enhancement methods is histogram equalization (HE because of its simplicity and effectiveness. However, it is rarely applied to consumer electronics products because it can cause excessive contrast enhancement and feature loss problems. These problems make the images processed by HE look unnatural and introduce unwanted artifacts in them. In this study, a visual contrast enhancement algorithm (VCEA based on HE is proposed. VCEA considers the requirements of the human visual perception in order to address the drawbacks of HE. It effectively solves the excessive contrast enhancement problem by adjusting the spaces between two adjacent gray values of the HE histogram. In addition, VCEA reduces the effects of the feature loss problem by using the obtained spaces. Furthermore, VCEA enhances the detailed textures of an image to generate an enhanced image with better visual quality. Experimental results show that images obtained by applying VCEA have higher contrast and are more suited to human visual perception than those processed by HE and other HE-based methods.

  7. Contrast-enhanced MR angiography in patients after kidney transplantation

    Energy Technology Data Exchange (ETDEWEB)

    Huber, A.; Heuck, A.; Scheidler, J.; Holzknecht, N.; Baur, A.; Reiser, M. [Klinikum Grosshadern, Muenchen (Germany). Radiologische Klinik und Poliklinik; Stangl, M.; Theodorakis, J.; Illner, W.-D.; Land, W. [Dept. of Transplant Surgery, Klinikum Grosshadern, Muenchen (Germany)

    2001-12-01

    The aim of this study was to investigate the value of a contrast-enhanced 3D MR angiography in detecting postoperative vascular complications after kidney transplantation in comparison with digital subtraction angiography (DSA). Forty-one patients who underwent a kidney transplantation were examined with MR angiography and DSA. Contrast-enhanced MR angiography was performed as a dynamic measurement with one precontrast and three postcontrast measurements. Maximum intensity projection reconstructions were performed for all postcontrast data sets after DSA. The results were evaluated by two independent observers who were unaware of the DSA results. Twenty-three hemodynamically significant arterial stenoses were identified with DSA in the iliac arteries (n=7), the renal allograft arteries (n=12), and in their first branches (n=4). For a patient-based analysis the sensitivity and specificity, respectively, for observer 1 were 100 and 97%, and for observer 2, 100 and 93%. Respective data were 100 and 100% after a consensus evaluation by two observers. Complications involving the renal veins were detected in 2 cases and perfusion defects of the kidney parenchyma were detected in 4 cases. Contrast-enhanced MR angiography is a reliable method in identifying postoperative arterial stenoses after kidney transplantation. In addition, dynamic MR angiography can be helpful in detecting venous complications and perfusion defects in kidney allografts. (orig.)

  8. Staging accuracy of pancreatic cancer: Comparison between non-contrast-enhanced and contrast-enhanced PET/CT

    Energy Technology Data Exchange (ETDEWEB)

    Yoneyama, Tomohiro [Department of Radiology, Yokohama City University, Graduate School of Medicine, Yokohama (Japan); Tateishi, Ukihide, E-mail: utateish@yokohama-cu.ac.jp [Department of Radiology, Yokohama City University, Graduate School of Medicine, Yokohama (Japan); Endo, Itaru [Department of Surgery, Yokohama City University, Graduate School of Medicine, Yokohama (Japan); Inoue, Tomio [Department of Radiology, Yokohama City University, Graduate School of Medicine, Yokohama (Japan)

    2014-10-15

    Purpose: Our aim was to clarify the diagnostic impact of contrast-enhanced (CE) {sup 18}F-fluorodeoxyglucose (FDG)–positron emission tomography (PET)/computed tomography (CT) for staging of pancreatic cancer compared to non-CE PET/CT. Method and materials: Between April 2006 and November 2009, a total of 95 patients (age range, 36–83 years [mean age, 67]) with primary pancreatic cancer underwent {sup 18}F-FDG PET/CT examinations. Diagnostic accuracy was compared between non-CE PET/CT and CE PET/CT. Images were analyzed visually and quantitatively by two blinded reviewers. Reference standard was histological examination in 48 patients (51%) and/or confirmation of an obvious progression in number and/or size of the lesions on follow-up CT examinations in 47 patients (49%). Results: For T-staging, invasion of duodenum (n = 20, 21%), mesentery (n = 12, 13%), and retroperitoneum (n = 13, 14%) was correctly diagnosed by both modalities. The ROC analyses revealed that the Az values of celiac artery (CA), common hepatic artery (CHA), splenic artery (SV), and superior mesenteric vein (SMV) invasion were significantly higher in the CE PET/CT group for both readers. Nodal metastasis was correctly diagnosed by CE PET/CT in 38 patients (88%) and by non-CE PET/CT in 45 patients (87%). Diagnostic accuracies of nodal metastasis in two modalities were similar. Using CE PET/CT, distant metastasis, scalene node metastasis, and peritoneal dissemination were correctly assigned in 39 patients (91%), while interpretation based on non-CE PET/CT revealed distant metastasis, scalene node metastasis, and peritoneal dissemination in 42 patients (81%). Diagnostic accuracy of distant metastasis, scalene node metastasis, and peritoneal dissemination with CE PET/CT was significantly higher than that of non-CE PET/CT (p < 0.05). Conclusion: CE PET/CT allows a more precise assessment of distant metastasis, scalene node metastasis, and peritoneal dissemination in patients with pancreatic cancer.

  9. 3D ECG- and respiratory-gated non-contrast-enhanced (CE) perfusion MRI for postoperative lung function prediction in non-small-cell lung cancer patients: A comparison with thin-section quantitative computed tomography, dynamic CE-perfusion MRI, and perfusion scan.

    Science.gov (United States)

    Ohno, Yoshiharu; Seki, Shinichiro; Koyama, Hisanobu; Yoshikawa, Takeshi; Matsumoto, Sumiaki; Takenaka, Daisuke; Kassai, Yoshimori; Yui, Masao; Sugimura, Kazuro

    2015-08-01

    To compare predictive capabilities of non-contrast-enhanced (CE)- and dynamic CE-perfusion MRIs, thin-section multidetector computed tomography (CT) (MDCT), and perfusion scan for postoperative lung function in non-small cell lung cancer (NSCLC) patients. Sixty consecutive pathologically diagnosed NSCLC patients were included and prospectively underwent thin-section MDCT, non-CE-, and dynamic CE-perfusion MRIs and perfusion scan, and had their pre- and postoperative forced expiratory volume in one second (FEV1 ) measured. Postoperative percent FEV1 (po%FEV1 ) was then predicted from the fractional lung volume determined on semiquantitatively assessed non-CE- and dynamic CE-perfusion MRIs, from the functional lung volumes determined on quantitative CT, from the number of segments observed on qualitative CT, and from uptakes detected on perfusion scans within total and resected lungs. Predicted po%FEV1 s were then correlated with actual po%FEV1 s, which were %FEV1 s measured postoperatively. The limits of agreement were also determined. All predicted po%FEV1 s showed significant correlation (0.73 ≤ r ≤ 0.93, P CE-perfusion MRI: 0.3 ± 10.0%, dynamic CE-perfusion MRI: 1.0 ± 10.8%, perfusion scan: 2.2 ± 14.1%, quantitative CT: 1.2 ± 9.0%, qualitative CT: 1.5 ± 10.2%). Non-CE-perfusion MRI may be able to predict postoperative lung function more accurately than qualitatively assessed MDCT and perfusion scan. © 2014 Wiley Periodicals, Inc.

  10. Medial tibial pain: a dynamic contrast-enhanced MRI study.

    Science.gov (United States)

    Mattila, K T; Komu, M E; Dahlström, S; Koskinen, S K; Heikkilä, J

    1999-09-01

    The purpose of this study was to compare the sensitivity of different magnetic resonance imaging (MRI) sequences to depict periosteal edema in patients with medial tibial pain. Additionally, we evaluated the ability of dynamic contrast-enhanced imaging (DCES) to depict possible temporal alterations in muscular perfusion within compartments of the leg. Fifteen patients with medial tibial pain were examined with MRI. T1-, T2-weighted, proton density axial images and dynamic and static phase post-contrast images were compared in ability to depict periosteal edema. STIR was used in seven cases to depict bone marrow edema. Images were analyzed to detect signs of compartment edema. Region-of-interest measurements in compartments were performed during DCES and compared with controls. In detecting periosteal edema, post-contrast T1-weighted images were better than spin echo T2-weighted and proton density images or STIR images, but STIR depicted the bone marrow edema best. DCES best demonstrated the gradually enhancing periostitis. Four subjects with severe periosteal edema had visually detectable pathologic enhancement during DCES in the deep posterior compartment of the leg. Percentage enhancement in the deep posterior compartment of the leg was greater in patients than in controls. The fast enhancement phase in the deep posterior compartment began slightly slower in patients than in controls, but it continued longer. We believe that periosteal edema in bone stress reaction can cause impairment of venous flow in the deep posterior compartment. MRI can depict both these conditions. In patients with medial tibial pain, MR imaging protocol should include axial STIR images (to depict bone pathology) with T1-weighted axial pre and post-contrast images, and dynamic contrast enhanced imaging to show periosteal edema and abnormal contrast enhancement within a compartment.

  11. Recent Experiences and Advances in Contrast-Enhanced Subharmonic Ultrasound

    Directory of Open Access Journals (Sweden)

    John R. Eisenbrey

    2015-01-01

    Full Text Available Nonlinear contrast-enhanced ultrasound imaging schemes strive to suppress tissue signals in order to better visualize nonlinear signals from blood-pooling ultrasound contrast agents. Because tissue does not generate a subharmonic response (i.e., signal at half the transmit frequency, subharmonic imaging has been proposed as a method for isolating ultrasound microbubble signals while suppressing surrounding tissue signals. In this paper, we summarize recent advances in the use of subharmonic imaging in vivo. These advances include the implementation of subharmonic imaging on linear and curvilinear arrays, intravascular probes, and three-dimensional probes for breast, renal, liver, plaque, and tumor imaging.

  12. Recent Experiences and Advances in Contrast-Enhanced Subharmonic Ultrasound.

    Science.gov (United States)

    Eisenbrey, John R; Sridharan, Anush; Liu, Ji-Bin; Forsberg, Flemming

    2015-01-01

    Nonlinear contrast-enhanced ultrasound imaging schemes strive to suppress tissue signals in order to better visualize nonlinear signals from blood-pooling ultrasound contrast agents. Because tissue does not generate a subharmonic response (i.e., signal at half the transmit frequency), subharmonic imaging has been proposed as a method for isolating ultrasound microbubble signals while suppressing surrounding tissue signals. In this paper, we summarize recent advances in the use of subharmonic imaging in vivo. These advances include the implementation of subharmonic imaging on linear and curvilinear arrays, intravascular probes, and three-dimensional probes for breast, renal, liver, plaque, and tumor imaging.

  13. How to Develop a Contrast-Enhanced Ultrasound Program.

    Science.gov (United States)

    Barr, Richard G

    2017-02-02

    With the recent Food and Drug Administration approval of Lumason (sulfur hexafluoride lipid-type A microsphere, Bracco Diagnostics Inc, Monroe Township, NJ) for contrast-enhanced ultrasound (CEUS) to characterize focal liver lesions in both adult and pediatric patients, widespread use of CEUS is expected in the United States. This paper provides guidance in setting up a CEUS program, and reviews the practical details that will need to be instituted in a standard ultrasound department to provide both safe and efficient use of CEUS. A review of the indications, contraindications, adverse events, instructions for performing the exam, and image interpretation are discussed.

  14. Contrast-enhanced CT- and MRI-based perfusion assessment for pulmonary diseases: basics and clinical applications.

    Science.gov (United States)

    Ohno, Yoshiharu; Koyama, Hisanobu; Lee, Ho Yun; Miura, Sachiko; Yoshikawa, Takeshi; Sugimura, Kazuro

    2016-01-01

    Assessment of regional pulmonary perfusion as well as nodule and tumor perfusions in various pulmonary diseases are currently performed by means of nuclear medicine studies requiring radioactive macroaggregates, dual-energy computed tomography (CT), and dynamic first-pass contrast-enhanced perfusion CT techniques and unenhanced and dynamic first-pass contrast enhanced perfusion magnetic resonance imaging (MRI), as well as time-resolved three-dimensional or four-dimensional contrast-enhanced magnetic resonance angiography (MRA). Perfusion scintigraphy, single-photon emission tomography (SPECT) and SPECT fused with CT have been established as clinically available scintigraphic methods; however, they are limited by perfusion information with poor spatial resolution and other shortcomings. Although positron emission tomography with 15O water can measure absolute pulmonary perfusion, it requires a cyclotron for generation of a tracer with an extremely short half-life (2 min), and can only be performed for academic purposes. Therefore, clinicians are concentrating their efforts on the application of CT-based and MRI-based quantitative and qualitative perfusion assessment to various pulmonary diseases. This review article covers 1) the basics of dual-energy CT and dynamic first-pass contrast-enhanced perfusion CT techniques, 2) the basics of time-resolved contrast-enhanced MRA and dynamic first-pass contrast-enhanced perfusion MRI, and 3) clinical applications of contrast-enhanced CT- and MRI-based perfusion assessment for patients with pulmonary nodule, lung cancer, and pulmonary vascular diseases. We believe that these new techniques can be useful in routine clinical practice for not only thoracic oncology patients, but also patients with different pulmonary vascular diseases.

  15. Contrast-enhanced breast ultrasonography: imaging features with histopathologic correlation.

    Science.gov (United States)

    Liu, He; Jiang, Yu-Xin; Liu, Ji-Bin; Zhu, Qing-Li; Sun, Qiang; Chang, Xiao-Yan

    2009-07-01

    The purpose of this study was to identify histopathologic correlates for the varied appearances of breast masses on contrast-enhanced ultrasonography (CEUS). Contrast-enhanced ultrasonography was performed in 104 patients (age range, 19-86 years) after administration of a sulfur hexafluoride microbubble contrast agent, and enhancement patterns were classified as no enhancement, peripheral enhancement, homogeneous enhancement, regional enhancement, and heterogeneous enhancement. All patients' histologic slides were reviewed and correlated with CEUS findings. In malignant masses, heterogeneous enhancement corresponded to tumor cell cords or clusters in a variable amount of desmoplastic stroma. Homogeneous enhancement corresponded to hypercellularity in the whole mass, or ductal carcinoma in situ (DCIS) was predominant. Regional enhancement corresponded to a DCIS component. Peripheral enhancement corresponded to a DCIS component, hypercellularity or adenosis at the periphery, and low-degree cellularity, degeneration, fibrosis, or necrosis in the center. No enhancement was present in 1 case of low-grade DCIS. In benign masses, heterogeneous enhancement corresponded to loose cell proliferation in a more sclerotic stroma. Homogeneous enhancement corresponded to diffuse hypercellularity, an inflammatory cell infiltrate, or intraductal papilloma. Regional enhancement corresponded to focal hypercellularity or intraductal papilloma within a dilated duct. No enhancement corresponded to desmoplastic stroma. Peripheral enhancement was shown in 1 case of granulomatous mastitis with an inflammatory infiltrate at the periphery and necrosis in the center. Breast mass CEUS findings correlated with histologic features.

  16. Contrast-enhanced ultrasound in detection and follow-up of pancreaticoduodenal artery pseudoaneurysm: a case report

    Institute of Scientific and Technical Information of China (English)

    ZHOU Lu-yao; XIE Xiao-yan; CHEN Dong; L(U) Ming-de

    2011-01-01

    Pancreaticoduodenal artery pseudoaneurysm is one kind of rare splanchnic artery aneurysm.Hemorrhage from the lesion could be life-threatening.We present a case which color Doppler ultrasound and computed tomography angiography (CTA) only showed pancreatic pseudocyst on the background of chronic pancreatitis at first,but contrast-enhanced ultrasound detected blood flow in the pseudocyst and a pancreaticoduodenal artery pseudoaneurysm was worked up several days after.Finally,the pancreaticoduodenal artery pseudoaneurysm was confirmed by digital subtracted angiography.It might suggest the potential advantage of contrast-enhanced ultrasound in evaluating this kind of disease in comparison of CTA.

  17. The diagnostic value of contrast-enhanced CT in Acute bilateral renal cortical necrosis: a case report

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Pil Youb; Lee, Su Han; Lee, Woo Dong [Masan Samsung General Hospital, Seoul (Korea, Republic of)

    1996-11-01

    Acute renal cortical necrosis in which there is destruction of the renal cortex and sparing of the renal medulla, is a relatively rare cause of acute renal failure. A definitive diagnosis of acute renal cortical necrosis is based on renal biopsy, but on CT(computed tomography) the rather specific contrast-enhanced appearance of acute renal cortical necrosis has been described. As renal biopsy is not available, contrast-enhanced CT is a useful, noninvasive investigate modality for the early diagnosis of acute renal cortical necrosis. We report the characteristic CT findings of acute renal cortical necrosis in a patient with acute renal failure following an operation for abdominal trauma.

  18. Focal Liver Lesions: Real-time 3-Dimensional Contrast-Enhanced Ultrasonography Compared With 2-Dimensional Contrast-Enhanced Ultrasonography and Magnetic Resonance Imaging.

    Science.gov (United States)

    Lee, Jung-Chieh; Yan, Kun; Lee, San-Kan; Yang, Wei; Chen, Min-Hua

    2017-06-24

    This study sought to evaluate the application of real-time 3-dimensional (3D) contrast-enhanced ultrasonography (US) to diagnose focal liver lesions and to compare these results with those from 2-dimensional (2D) contrast-enhanced US and contrast-enhanced magnetic resonance imaging (MRI). Patients with focal liver lesions were examined by 2D contrast-enhanced US, 3D contrast-enhanced US, and contrast-enhanced MRI for lesion characterization, and biopsies and comprehensive clinical diagnoses served as reference standards. The sensitivity, specificity, area under the receiver operating characteristic curve, and intermodality agreement were assessed. The number of contrast agent injections and lesions observed per injection were calculated for 3D and 2D contrast-enhanced US. The number and display quality of the feeding arteries observed with 3D and 2D contrast-enhanced US were assessed. A total of 117 patients with 151 focal liver lesions were enrolled, including 67 cases of hepatocellular carcinoma, 51 cases of liver metastasis, and 33 cases of benign liver lesions. No significant differences were found among the modalities. The sensitivity values for 3D contrast-enhanced US, 2D contrast-enhanced US, and contrast-enhanced MRI were 96%, 95%, and 93%, respectively; the specificity values were 87%, 84%, and 89%; and the area under the receiver operating characteristic curve values were 0.92, 0.90, and 0.92. The intermodality agreement was excellent (κ > 0.77). Fewer contrast agent injections were needed, and more lesions and feeding arteries were more clearly displayed on 3D than 2D contrast-enhanced US (P < .001). Real-time 3D contrast-enhanced US is useful for diagnosing focal liver lesions and for observing feeding arteries with fewer contrast agent injections. © 2017 by the American Institute of Ultrasound in Medicine.

  19. Value of contrast-enhanced ultrasound in rheumatoid arthritis

    Energy Technology Data Exchange (ETDEWEB)

    Zordo, Tobias de; Mlekusch, Sabine P.; Feuchtner, Gudrun M. [Department of Radiology II, Medical University Innsbruck, Anichstrasse 35, 6020 Innsbruck (Austria); Mur, Erich [Department of Internal Medicine, Medical University Innsbruck, Anichstrasse 35, 6020 Innsbruck (Austria); Schirmer, Michael [Department of Internal Medicine, Hospital of the Elisabethines Klagenfurt, Voelkermarkter Strasse 15-19, 9020 Klagenfurt (Austria); Klauser, Andrea S. [Department of Radiology II, Medical University Innsbruck, Anichstrasse 35, 6020 Innsbruck (Austria)], E-mail: andrea.klauser@i-med.ac.at

    2007-11-15

    The purpose of this review is to describe the spectrum of sonographic findings in rheumatic diseases with respect to the diagnostic potential using US contrast media which prove activity or inactivity in synovial tissue where new treatment regimes target. Synovial activity can be found in non-erosive and erosive forms of primary and secondary osteoarthritis, and in inflammatory forms of joint diseases like rheumatoid arthritis and peripheral manifestations of spondyloarthritis including, ankylosing spondylitis, Reiter's syndrome, psoriatic arthritis and enteropathic arthritis. It can also be present in metabolic and endocrine forms of arthritis, in connective tissue arthropathies like systemic lupus erythematosus or scleroderma and in infectious arthritis. Ultrasound should be used as first-line imaging modality in suspected early cases of RA and other forms of arthritis, whereas contrast-enhanced ultrasound (CEUS) can further enable for sensitive assessment of vascularity which correlates with disease activity.

  20. Contrast Enhancement of Color Images with Bi-Histogram

    Directory of Open Access Journals (Sweden)

    Paramjit Singh,

    2014-06-01

    Full Text Available Histogram equalization is a widely used scheme for contrast enhancement in a variety of applications due to its simple function and effectiveness. One possible drawback of the histogram equalization is that it can change the mean brightness of an image significantly as a consequence of histogram flattening. Clearly, this is not a desirable property when preserving the original mean brightness of a given image is necessary. Bi-histogram equalization is able to overcome this drawback for gray scale images. In this paper, we explore the use of bi-histogram equalization based technique for enhancing RGB color images. The technique is based on cumulative density function of a quantized image. From the results it is concluded that bi-histogram equalization is able to improve the contrast of colored images significantly.

  1. Design of a clinical vein contrast enhancing projector

    Science.gov (United States)

    Zeman, Herbert D.; Lovhoiden, Gunnar; Deshmukh, Harshal

    2001-06-01

    A clinical study has been initiated to compare an experimental IR device, the Vein Contrast Enhancer (VCE), with standard techniques for finding veins for venipuncture. The aims of this proposal are (1) to evaluate the performance of the VCE in a clinical setting, specifically by comparing its sensitivity of detection with existing vein-finding techniques used by experienced nurses or phlebotomists, (2) to study its usefulness in subjects who are obese, who have difficult venous access or thrombosed veins, or whose veins are not visible or difficult to palpate, and (3) to show that it performs as well on subjects with darkly pigmented skin as on subjects with lightly pigmented skin. The VCE will first be studied in adult subjects, and then in pediatric subjects.

  2. Research on Wavelet-Based Algorithm for Image Contrast Enhancement

    Institute of Scientific and Technical Information of China (English)

    Wu Ying-qian; Du Pei-jun; Shi Peng-fei

    2004-01-01

    A novel wavelet-based algorithm for image enhancement is proposed in the paper. On the basis of multiscale analysis, the proposed algorithm solves efficiently the problem of noise over-enhancement, which commonly occurs in the traditional methods for contrast enhancement. The decomposed coefficients at same scales are processed by a nonlinear method, and the coefficients at different scales are enhanced in different degree. During the procedure, the method takes full advantage of the properties of Human visual system so as to achieve better performance. The simulations demonstrate that these characters of the proposed approach enable it to fully enhance the content in images, to efficiently alleviate the enhancement of noise and to achieve much better enhancement effect than the traditional approaches.

  3. Microvascular contrast enhancement in optical coherence tomography using microbubbles

    Science.gov (United States)

    Assadi, Homa; Demidov, Valentin; Karshafian, Raffi; Douplik, Alexandre; Vitkin, I. Alex

    2016-07-01

    Gas microbubbles (MBs) are investigated as intravascular optical coherence tomography (OCT) contrast agents. Agar + intralipid scattering tissue phantoms with two embedded microtubes were fabricated to model vascular blood flow. One was filled with human blood, and the other with a mixture of human blood + MB. Swept-source structural and speckle variance (sv) OCT images, as well as speckle decorrelation times, were evaluated under both no-flow and varying flow conditions. Faster decorrelation times and higher structural and svOCT image contrasts were detected in the presence of MB in all experiments. The effects were largest in the svOCT imaging mode, and uniformly diminished with increasing flow velocity. These findings suggest the feasibility of utilizing MB for tissue hemodynamic investigations and for microvasculature contrast enhancement in OCT angiography.

  4. Contrast enhancing solution for use in confocal microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Tannous, Zeina; Torres, Abel; Gonzalez, Salvador

    2006-10-31

    A method of optically detecting a tumor during surgery. The method includes imaging at least one test point defined on the tumor using a first optical imaging system to provide a first tumor image. The method further includes excising a first predetermined layer of the tumor for forming an in-vivo defect area. A predetermined contrast enhancing solution is disposed on the in-vivo defect area, which is adapted to interact with at least one cell anomaly, such as basal cell carcinoma, located on the in-vivo defect area for optically enhancing the cell anomaly. Thereafter the defect area can be optically imaged to provide a clear and bright representation of the cell anomaly to aid a surgeon while surgically removing the cell anomaly.

  5. Photon counting CT of the liver with dual-contrast enhancement

    Science.gov (United States)

    Muenzel, Daniela; Proksa, Roland; Daerr, Heiner; Fingerle, Alexander A.; Pfeiffer, Franz; Rummeny, Ernst J.; Noël, Peter B.

    2016-03-01

    The diagnostic quality of photon counting computed tomography (PCCT) is one the unexplored areas in medical imaging; at the same time, it seems to offer the opportunity as a fast and highly sensitive diagnostic tool. Today, conventional computed tomography (CT) is the standard imaging technique for diagnostic evaluation of the parenchyma of the liver. However, considerations on radiation dose are still an important factor in CT liver imaging, especially with regard to multi-phase contrast enhanced CT. In this work we report on a feasibility study for multi-contrast PCCT for simultaneous liver imaging at different contrast phases. PCCT images of the liver were simulated for a contrast-enhanced examination performed with two different contrast agents (CA), iodine (CA 1) and gadolinium (CA 2). PCCT image acquisition was performed at the time point with portal venous contrast distribution of CA 1 and arterial contrast phase for CA 2. Therefore, a contrast injection protocol was planned with sequential injection of CA 1 and CA 2 to provide a time dependent difference in contrast distribution of both CAs in the vessels and parenchyma of the liver. Native, arterial, and portal venous contrast enhanced images have been calculated based on the spectral separation of PCCT. In simulated PCCT images, we were able to differentiate between the tissue enhancement of CA 1 and CA 2. The distribution of both CA within the parenchyma of the liver was illustrated with perfusion maps for CA 1 and CA 2. In addition, virtual noncontrast enhanced image were calculated. In conclusion, multi-phase PCCT imaging of the liver based on a single scan is a novel approach for spectral PCCT imaging, offering detailed contrast information in a single scan volume and a significant reduction of radiation dose.

  6. Contrast-enhanced ultrasound in diagnosis of gallbladder adenoma

    Institute of Scientific and Technical Information of China (English)

    Hai-Xia Yuan; Jia-Ying Cao; Wen-Tao Kong; Han-Sheng Xia; Xi Wang; Wen-Ping Wang

    2015-01-01

    BACKGROUND:Gallbladder adenoma is a pre-cancerous neoplasm and needs surgical resection. It is dififcult to differ-entiate adenoma from other gallbladder polyps using imaging examinations. The study aimed to illustrate characteristics of contrast-enhanced ultrasound (CEUS) and its diagnostic value in gallbladder adenoma. METHODS:Thirty-seven patients with 39 gallbladder adenoma-toid lesions (maximal diameter≥10 mm and without metastasis) were enrolled in this study. Lesion appearances in conventional ultrasound and CEUS were documented. The imaging features were compared individually among gallbladder cholesterol polyp, gallbladder adenoma and malignant lesion. RESULTS:Adenoma lesions showed iso-echogenicity in ul-trasound, and an eccentric enhancement pattern, "fast-in and synchronous-out" contrast enhancement pattern and homo-geneous at peak-time enhancement in CEUS. The homogenic-ity at peak-time enhancement showed the highest diagnostic ability in differentiating gallbladder adenoma from cholesterol polyps. The sensitivity, speciifcity, positive predictive value, negative predictive value, accuracy and Youden index were 100%, 90.9%, 92.9%, 100%, 95.8% and 0.91, respectively. The characteristic of continuous gallbladder wall shown by CEUS had the highest diagnostic ability in differentiating adenoma from malignant lesion (100%, 86.7%, 86.7%, 100%, 92.9% and 0.87, respectively). The characteristic of the eccentric enhance-ment pattern had the highest diagnostic ability in differenti-ating adenoma from cholesterol polyp and malignant lesion, with corresponding indices of 69.2%, 88.5%, 75.0%, 85.2%, 82.1% and 0.58, respectively. CONCLUSIONS:CEUS is valuable in differentiating gallbladder adenoma from other gallbladder polyps (≥10 mm in diameter). Homogeneous echogenicity on peak-time enhancement, a con-tinuous gallbladder wall, and the eccentric enhancement pat-tern are important indicators of gallbladder adenoma on CEUS.

  7. Quantitative Assessment of Hepatic Fibrosis by Contrast-enhanced Ultrasonography

    Institute of Scientific and Technical Information of China (English)

    Ming-bo Zhang; En-ze Qu; Ji-Bin Liu; Jin-rui Wang

    2011-01-01

    Objective To explore the contrast-enhanced ultrasonographic features for quantitative assessment of hepatic fibrosis.Methods 86 patients with chronic viral hepatitis B were enrolled in this study from March 2007 to August 2009.The patients were classified into 5 groups (S0-S4) according to fibrosis stage evaluated with ultrasound guided liver biopsy.New contrast-enhanced ultrasonography (CEUS) features including area under the time-intensity curve (TIC) of portal venous phase/hepatic arterial phase (Qp/Qa) and intensity of portal venons phase/hepatic arterial phase (Ip/Ia) were used to detect the blood supply ratio (portal vein/hepatic artery) in each group.Arrival time of portal vein trunk (Tp) and decreasing rate of TIC (β) were also analyzed.Results Qp/Qa and Ip/Ia decreased from So to S4,while Tp and β increased These 4 features were significantly correlated with the degree of fibrosis (P<0.001) and were significantly different among the five groups (P<0.001).Sensitivity and specificity of Ip/Ia were 80% and 86% for groups ≥S1,75% and 86% for groups ≥ S2,71% and 84% for groups ≥ S3,and 76% and 80% for group S4,respectively.Sensitivity and specificity of Qp/Qa were 70% and 88% for groups ≥ S1,80% and 76% for groups ≥ S2,74% and 70% for groups ≥ S3,and 81% and 95% for group S4,respectively.Conclusion Ip/Ia and Qp/Qa could be adopted as reliable,non-invasive features for quantitative assessment of hepatic fibrosis.

  8. Dynamic Contrast-Enhanced MRI of Cervical Cancers: Temporal Percentile Screening of Contrast Enhancement Identifies Parameters for Prediction of Chemoradioresistance

    Energy Technology Data Exchange (ETDEWEB)

    Andersen, Erlend K.F. [Department of Medical Physics, Oslo University Hospital, Oslo (Norway); Hole, Knut Hakon; Lund, Kjersti V. [Department of Radiology, Oslo University Hospital, Oslo (Norway); Sundfor, Kolbein [Department of Gynaecological Oncology, Oslo University Hospital, Oslo (Norway); Kristensen, Gunnar B. [Department of Gynaecological Oncology, Oslo University Hospital, Oslo (Norway); Institute for Medical Informatics, Oslo University Hospital, Oslo (Norway); Lyng, Heidi [Department of Radiation Biology, Oslo University Hospital, Oslo (Norway); Malinen, Eirik, E-mail: eirik.malinen@fys.uio.no [Department of Medical Physics, Oslo University Hospital, Oslo (Norway); Department of Physics, University of Oslo, Oslo (Norway)

    2012-03-01

    Purpose: To systematically screen the tumor contrast enhancement of locally advanced cervical cancers to assess the prognostic value of two descriptive parameters derived from dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI). Methods and Materials: This study included a prospectively collected cohort of 81 patients who underwent DCE-MRI with gadopentetate dimeglumine before chemoradiotherapy. The following descriptive DCE-MRI parameters were extracted voxel by voxel and presented as histograms for each time point in the dynamic series: normalized relative signal increase (nRSI) and normalized area under the curve (nAUC). The first to 100th percentiles of the histograms were included in a log-rank survival test, resulting in p value and relative risk maps of all percentile-time intervals for each DCE-MRI parameter. The maps were used to evaluate the robustness of the individual percentile-time pairs and to construct prognostic parameters. Clinical endpoints were locoregional control and progression-free survival. The study was approved by the institutional ethics committee. Results: The p value maps of nRSI and nAUC showed a large continuous region of percentile-time pairs that were significantly associated with locoregional control (p < 0.05). These parameters had prognostic impact independent of tumor stage, volume, and lymph node status on multivariate analysis. Only a small percentile-time interval of nRSI was associated with progression-free survival. Conclusions: The percentile-time screening identified DCE-MRI parameters that predict long-term locoregional control after chemoradiotherapy of cervical cancer.

  9. Comparison of Thoracic Radiography and Computed Tomography in Calves with Naturally Occurring Respiratory Disease

    Directory of Open Access Journals (Sweden)

    Jennifer Fowler

    2017-07-01

    Full Text Available ObjectiveTo evaluate the severity and extent of lung disease using thoracic computed radiography (CR compared to contrast-enhanced multi-detector computed tomography (MDCT of the thorax in calves with naturally occurring respiratory disease and to evaluate the feasibility and safety of performing contrast-enhanced thoracic multi-detector MDCT examinations in sedated calves. Furthermore, to evaluate if combining CR or MDCT with respiratory scoring factors will improve prediction of the chronicity of pulmonary disease in calves.AnimalsThirty Jersey heifer calves ranging in age between 25 and 89 days with naturally occurring respiratory disease.ProceduresAll calves were evaluated via thoracic CR and contrast-enhanced MDCT. All calves were euthanized immediately following thoracic MDCT and submitted for necropsy. Imaging and histopathology results were compared with each other.ResultsThoracic MDCT was superior for evaluation of pneumonia in calves due to the lack of summation in all areas of the lungs. Intravenously administered sedation provided an adequate plane of sedation for acquiring MDCT images of diagnostic quality, without the need for re-scanning. A diagnosis of pneumonia was made with equal rate on both thoracic CR and MDCT. Although mild differences in classification of lung pattern and extent of lung disease were seen when comparing an experienced and a less experienced evaluator, the overall differences were not statistically significant. The best intra- and inter-observer agreement was noted when evaluating the cranioventral aspects of the lungs in either modality. Clinical respiratory scoring is inadequate for diagnosing chronicity of pneumonia in calves with naturally occurring pneumonia.Conclusion and clinical importanceBoth imaging modalities allowed diagnosis of pneumonia in calves. The cranial ventral aspects of the lungs were most commonly affected. Thoracic CR and MDCT provided similar diagnostic effectiveness in diagnosing

  10. CT findings in autoimmune pancreatitis: assessment using multiphase contrast-enhanced multisection CT

    Energy Technology Data Exchange (ETDEWEB)

    Suzuki, K., E-mail: Kojiro@med.nagoya-u.ac.j [Department of Radiology, Nagoya University Graduate School of Medicine, Nagoya (Japan); Itoh, S. [Department of Radiology, Nagoya Hirokoji Clinic, Nagoya (Japan); Nagasaka, T. [Departments of Medical Technology, Nagoya University School of Health Science, Nagoya (Japan); Ogawa, H.; Ota, T.; Naganawa, S. [Department of Radiology, Nagoya University Graduate School of Medicine, Nagoya (Japan)

    2010-09-15

    Aim: To assess the spectrum of findings using multiphase contrast-enhanced computed tomography (CT) in patients with autoimmune pancreatitis (AIP). Materials and methods: Fifty patients (four female and 46 male, mean age 65 years) were retrospectively identified from consecutive patients with abnormal CT findings of the pancreas and negative work-up for known causes. These patients had at least one finding supporting the diagnosis of AIP: serological abnormality, histopathological abnormality, or response to steroid. Two radiologists evaluated multiphase contrast-enhanced CT images in consensus. Results: The pancreas showed diffuse enlargement (n = 16; 32%), focal enlargement (n = 18; 36%), or no enlargement (n = 16; 32%). Forty-nine (98%) patients showed abnormal contrast enhancement in the affected pancreatic parenchyma, including hypoattenuation during the pancreatic phase (n = 45; 90%) and hyperattenuation during the delayed phase (n = 39; 87%). The following findings were also seen in the pancreas: a capsule-like rim (n = 24; 48%); no visualization of the main pancreatic duct lumen (n = 48; 96%); ductal enhancement (n = 26; 52%); upstream dilatation of the main pancreatic duct (n = 27; 54%); upstream atrophy of the pancreatic parenchyma (n = 27; 54%); calcification (n = 7; 14%); and cysts (n = 5; 10%). Forty-two (84%) patients showed one or more of the following extrapancreatic findings: biliary duct or gallbladder abnormality (n = 40; 80%); peripancreatic (n = 8; 16%) or para-aortic (n = 10; 20%) soft-tissue proliferation; and renal involvement (n = 15; 30%). Conclusion: Patients with AIP presented with a variety of CT findings in the pancreas and the extrapancreatic organs. The present study highlights pancreatic ductal enhancement in a subset of patients with AIP.

  11. Global and local contrast enhancement algorithm for image using wavelet neural network and stationary wavelet transform

    Institute of Scientific and Technical Information of China (English)

    Changjiang Zhang; Xiaodong Wang; Haoran Zhang

    2005-01-01

    A new contrast enhancement algorithm for image is proposed employing wavelet neural network (WNN)and stationary wavelet transform (SWT). Incomplete Beta transform (IBT) is used to enhance the global contrast for image. In order to avoid the expensive time for traditional contrast enhancement algorithms,which search optimal gray transform parameters in the whole gray transform parameter space, a new criterion is proposed with gray level histogram. Contrast type for original image is determined employing the new criterion. Gray transform parameter space is given respectively according to different contrast types,which shrinks the parameter space greatly. Nonlinear transform parameters are searched by simulated annealing algorithm (SA) so as to obtain optimal gray transform parameters. Thus the searching direction and selection of initial values of simulated annealing is guided by the new parameter space. In order to calculate IBT in the whole image, a kind of WNN is proposed to approximate the IBT. Having enhanced the global contrast to input image, discrete SWT is done to the image which has been processed by previous global enhancement method, local contrast enhancement is implemented by a kind of nonlinear operator in the high frequency sub-band images of each decomposition level respectively. Experimental results show that the new algorithm is able to adaptively enhance the global contrast for the original image while it also extrudes the detail of the targets in the original image well. The computation complexity for the new algorithm is O(MN) log(MN), where M and N are width and height of the original image, respectively.

  12. Automatic segmentation and quantification of the cardiac structures from non-contrast-enhanced cardiac CT scans

    Science.gov (United States)

    Shahzad, Rahil; Bos, Daniel; Budde, Ricardo P. J.; Pellikaan, Karlijn; Niessen, Wiro J.; van der Lugt, Aad; van Walsum, Theo

    2017-05-01

    Early structural changes to the heart, including the chambers and the coronary arteries, provide important information on pre-clinical heart disease like cardiac failure. Currently, contrast-enhanced cardiac computed tomography angiography (CCTA) is the preferred modality for the visualization of the cardiac chambers and the coronaries. In clinical practice not every patient undergoes a CCTA scan; many patients receive only a non-contrast-enhanced calcium scoring CT scan (CTCS), which has less radiation dose and does not require the administration of contrast agent. Quantifying cardiac structures in such images is challenging, as they lack the contrast present in CCTA scans. Such quantification would however be relevant, as it enables population based studies with only a CTCS scan. The purpose of this work is therefore to investigate the feasibility of automatic segmentation and quantification of cardiac structures viz whole heart, left atrium, left ventricle, right atrium, right ventricle and aortic root from CTCS scans. A fully automatic multi-atlas-based segmentation approach is used to segment the cardiac structures. Results show that the segmentation overlap between the automatic method and that of the reference standard have a Dice similarity coefficient of 0.91 on average for the cardiac chambers. The mean surface-to-surface distance error over all the cardiac structures is 1.4+/- 1.7 mm. The automatically obtained cardiac chamber volumes using the CTCS scans have an excellent correlation when compared to the volumes in corresponding CCTA scans, a Pearson correlation coefficient (R) of 0.95 is obtained. Our fully automatic method enables large-scale assessment of cardiac structures on non-contrast-enhanced CT scans.

  13. Cerebellar dermoid cyst with contrast enhancement mural nodule: case report.

    Science.gov (United States)

    Morina, Arsim; Kelmendi, Fatos; Morina, Qamile; Morina, Dukagjin

    2014-12-01

    Typical dermoid cysts are well-circumscribed fat-density masses with no associated contrast enhancement; rarely, they may appear hyperattenuating on CT scan. CT hyperattenuating dermoid cyst (CHADC) is very uncommon, with only nine case reports in the literature update, which occurs exclusively in the posterior fossa. CHADC with mural nodule is extremely rare and, to the best of our knowledge, only two cases have been documented previously in the literature. A 49-year-old farmer had a 2-month history of occipital headaches, which were not suggestive of raised intracranial pressure. During the last month, he experienced loss of balance, frequent falls, anorexia and loss of weight. Magnetic resonance imaging (MRI) showed a huge mass from the tentorium to the foramen occipitale magnum with obliteration of the fourth ventricle; the lesion was well circumscribed. We completely removed the tumor and postoperative MRI showed no residual tumor. Epidermoid tumors with enhancing mural nodule on MRI and with hyperattenuating lesion on CT are extremely rare. Dermoid cysts are never associated with edema and extremely rarely cause obstructive hydrocephalus. MRI investigations are mandatory to diagnose these cases. The best curative treatment is total removal of the lesion.

  14. Mass-forming pancreatitis: Value of contrast-enhanced ultrasonography

    Institute of Scientific and Technical Information of China (English)

    Mirko D'Onofrio; Giulia Zamboni; Alessia Tognolini; Roberto Malagò; Niccolò Faccioli; Luca Frulloni; Roberto Pozzi Mucelli

    2006-01-01

    AIM: To assess the utility of contrast-enhanced ultrasonography (CEUS) with a second-generation contrast medium in the differential diagnosis between mass-forming pancreatitis and pancreatic carcinoma.METHODS: From our radio-pathology database, we retrieved all the patients affected by mass-forming pancreatitis or pancreatic carcinoma who underwent CEUS. We evaluated the results of CEUS in the study of the 173 pancreatic masses considering the possibilities of a differential diagnosis between mass-forming pancreatitis and pancreatic tumor by identifying the "parenchymographic" enhancement during the dynamic phase of CEUS, which was considered diagnostic for mass-forming pancreatitis.RESULTS: At CEUS, 94% of the mass-forming pancreatitis showed intralesional parenchymography.CEUS allowed diagnosis of mass-forming pancreatitis with sensitivity of 88.6%, specificity of 97.8%,positive predictive value of 91.2%, negative predictive value of 97.1%, and overall accuracy of 96%. CEUS significantly increased the diagnostic confidence in the differential diagnosis between mass-forming pancreatitis and pancreatic carcinoma, with receiver operating characteristic curve areas from 0.557 (P = 0.1608) for baseline US to 0.956 (P < 0.0001) for CEUS.CONCLUSION: CEUS allowed diagnosis of massforming pancreatitis with diagnostic accuracy of 96%. CEUS significantly increases the diagnostic confidence with respect to basal US in discerning mass-forming pancreatitis from pancreatic neoplasm.

  15. Image fusion for dynamic contrast enhanced magnetic resonance imaging

    Directory of Open Access Journals (Sweden)

    Leach Martin O

    2004-10-01

    Full Text Available Abstract Background Multivariate imaging techniques such as dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI have been shown to provide valuable information for medical diagnosis. Even though these techniques provide new information, integrating and evaluating the much wider range of information is a challenging task for the human observer. This task may be assisted with the use of image fusion algorithms. Methods In this paper, image fusion based on Kernel Principal Component Analysis (KPCA is proposed for the first time. It is demonstrated that a priori knowledge about the data domain can be easily incorporated into the parametrisation of the KPCA, leading to task-oriented visualisations of the multivariate data. The results of the fusion process are compared with those of the well-known and established standard linear Principal Component Analysis (PCA by means of temporal sequences of 3D MRI volumes from six patients who took part in a breast cancer screening study. Results The PCA and KPCA algorithms are able to integrate information from a sequence of MRI volumes into informative gray value or colour images. By incorporating a priori knowledge, the fusion process can be automated and optimised in order to visualise suspicious lesions with high contrast to normal tissue. Conclusion Our machine learning based image fusion approach maps the full signal space of a temporal DCE-MRI sequence to a single meaningful visualisation with good tissue/lesion contrast and thus supports the radiologist during manual image evaluation.

  16. Contrast-Enhanced Endoscopic Ultrasonography for Pancreatic Tumors

    Directory of Open Access Journals (Sweden)

    Yasunobu Yamashita

    2015-01-01

    Full Text Available Objectives. To investigate the usefulness of contrast-enhanced endoscopic ultrasonography (CE-EUS for histological differentiation of pancreatic tumors. Methods. CE-EUS was performed for consecutive patients having a pancreatic solid lesion, and tumors were classified into three vascular patterns (hypervascular, isovascular, and hypovascular at two time phases (early-phase and late-phase. Correlation between vascular patterns and histopathology of resected pancreatic cancer (PC tissues was ascertained. Results. The final diagnoses of 147 examined tumors were PC (n=109, inflammatory mass (n=11, autoimmune pancreatitis (n=9, neuroendocrine tumor (n=8, and others (n=10. In late-phase images, 104 of 109 PCs had the hypovascular pattern, for a diagnostic sensitivity and specificity of 94% and 71%, respectively. Of 28 resected PCs, 10 had isovascular, and 18 hypovascular, patterns on the early-phase image. Early-phase isovascular PCs were more likely to be differentiated than were early-phase hypovascular PCs (6 well and 4 moderately differentiated versus 3 well, 14 moderately, and 1 poorly differentiated, P=0.028. Immunostaining revealed that hypovascular areas of early-phase images reflected heterogeneous tumor cells with fibrous tissue, necrosis, and few vessels. Conclusion. CE-EUS could be useful for distinguishing PC from other solid pancreatic lesions and for histological differentiation of PCs.

  17. Assessing Tumor Angiogenesis with Dynamic Contrast Enhanced Magnetic Resonance Imaging

    Science.gov (United States)

    Esparza-Coss, Emilio; Jackson, Edward F.

    2006-09-01

    Dynamic contrast enhanced magnetic resonance imaging (DCE-MRI) is a method able of assessing microvascular changes at high spatial resolution and without ionizing radiation. The microcirculation and structure of tumors are fundamentally chaotic in that tumor-derived factors stimulate the endothelial cells to form new small vessels (angiogenesis) and this vasculature deviates markedly from normal hierarchical branching patterns. The tumor-induced microvascular changes lead to blood flow that is both spatially and temporally more heterogeneous than the efficient and uniform perfusion of normal organs and tissues. DCE-MRI allows for the assessment of perfusion and permeability of the tumor microvasculature, including the network of vessels with diameters less than 100 μm, which are beyond the resolution of conventional angiograms. The microvessel permeability to small molecular weight contrast media as well as measures of tumor response can be assessed with different analysis techniques ranging from simple measures of enhancement to pharmacokinetic models. In this work, such DCE-MRI analysis techniques are discussed.

  18. Dynamic contrast-enhanced 3D photoacoustic imaging

    Science.gov (United States)

    Wong, Philip; Kosik, Ivan; Carson, Jeffrey J. L.

    2013-03-01

    Photoacoustic imaging (PAI) is a hybrid imaging modality that integrates the strengths from both optical imaging and acoustic imaging while simultaneously overcoming many of their respective weaknesses. In previous work, we reported on a real-time 3D PAI system comprised of a 32-element hemispherical array of transducers. Using the system, we demonstrated the ability to capture photoacoustic data, reconstruct a 3D photoacoustic image, and display select slices of the 3D image every 1.4 s, where each 3D image resulted from a single laser pulse. The present study aimed to exploit the rapid imaging speed of an upgraded 3D PAI system by evaluating its ability to perform dynamic contrast-enhanced imaging. The contrast dynamics can provide rich datasets that contain insight into perfusion, pharmacokinetics and physiology. We captured a series of 3D PA images of a flow phantom before and during injection of piglet and rabbit blood. Principal component analysis was utilized to classify the data according to its spatiotemporal information. The results suggested that this technique can be used to separate a sequence of 3D PA images into a series of images representative of main features according to spatiotemporal flow dynamics.

  19. Quantitative contrast-enhanced MR imaging of the optic nerve

    Energy Technology Data Exchange (ETDEWEB)

    Simon, J.H. [Depts. of Radiology, Univ. of Colorado Health Sciences Center, Denver, CO (United States)]|[Iowa Univ., Iowa City, IA (United States); Rubinstein, D. [Depts. of Radiology, Univ. of Colorado Health Sciences Center, Denver, CO (United States)]|[Iowa Univ., Iowa City, IA (United States); Brown, M. [Depts. of Radiology, Univ. of Colorado Health Sciences Center, Denver, CO (United States)]|[Iowa Univ., Iowa City, IA (United States); Yuh, W. [Depts. of Radiology, Univ. of Colorado Health Sciences Center, Denver, CO (United States)]|[Iowa Univ., Iowa City, IA (United States); Birch-Iensen, M. [Depts. of Radiology, Univ. of Colorado Health Sciences Center, Denver, CO (United States)]|[Iowa Univ., Iowa City, IA (United States); Szumowski, J. [Depts. of Radiology, Univ. of Colorado Health Sciences Center, Denver, CO (United States)]|[Iowa Univ., Iowa City, IA (United States); Stears, J. [Depts. of Radiology, Univ. of Colorado Health Sciences Center, Denver, CO (United States)]|[Iowa Univ., Iowa City, IA (United States)

    1994-11-01

    During the acute stages of optic neuritis damage to the blood-optic nerve barrier can be detected using i.v. paramagnetic contrast-enhanced MR imaging. Quantification of the enhancement pattern of the optic nerve, intraorbital fat and muscle was determined in 15 normal subjects using 3 fat-suppression MR imaging methods: T1-weighted spin-echo and spoiled gradient-echo sequences preceded by a flat-frequency selective pulse (FATSAT+SE and FATSAT+SPGR, respectively) and a pulse sequence combining CHOPPER fat suppression with a fat-frequency selective preparation pulse (HYBRID). Pre- and postcontrast-enhanced studies were acquired for FATSAT+SE and FATSAT+SPGR. There was no significant enhancement of the optic nerve by either method (mean increase of 0.96% and 5.3%, respectively), while there was significant enhancement in muscle (mean 118.2% and 108.2%, respectively; p<0.005) and fat (mean increase of 13% and 37%, respectively; p<0.05). Postcontrast optic nerve/muscle signal intensity ratios (mean, SD) were 0.51 (0.07), 0.58 (0.05) and 0.75 (0.05) for FATSAT+SE, FATSAT+SPGR and HYBRID, respectively. These results suggest a practical methodology and range of values for normal signal intensity increases and ratios of tissue signal that can be used as objective measures of optic neuritis for natural history studies and treatment trials. (orig.).

  20. Contrast-enhanced MRI of murine myocardial infarction - part II.

    Science.gov (United States)

    Coolen, Bram F; Paulis, Leonie E M; Geelen, Tessa; Nicolay, Klaas; Strijkers, Gustav J

    2012-08-01

    Mouse models are increasingly used to study the pathophysiology of myocardial infarction in vivo. In this area, MRI has become the gold standard imaging modality, because it combines high spatial and temporal resolution functional imaging with a large variety of methods to generate soft tissue contrast. In addition, (target-specific) MRI contrast agents can be employed to visualize different processes in the cascade of events following myocardial infarction. Here, the MRI sequence has a decisive role in the detection sensitivity of a contrast agent. However, a straightforward translation of clinically available protocols for human cardiac imaging to mice is not feasible, because of the small size of the mouse heart and its extremely high heart rate. This has stimulated intense research in the development of cardiac MRI protocols specifically tuned to the mouse with regard to timing parameters, acquisition strategies, and ECG- and respiratory-triggering methods to find an optimal trade-off between sensitivity, scan time, and image quality. In this review, a detailed analysis is given of the pros and cons of different mouse cardiac MR imaging methodologies and their application in contrast-enhanced MRI of myocardial infarction. Copyright © 2012 John Wiley & Sons, Ltd.

  1. Nanoparticles and nanostructured carriers for drug delivery and contrast enhancement

    Science.gov (United States)

    Godage, Olga S.; Bucharskaya, Alla B.; Navolokin, Nikita A.; German, Sergey V.; Zuev, Viktor V.; Terentyuk, Georgy S.; Maslyakova, Galina N.; Gorin, Dmitry A.

    2016-04-01

    Currently, nanotechnologies are widely used in science and industry. It is known that the application of drug delivery nanostructured carriers for biomedicine is one of the promising areas of nanotechnology. Nanostructured carriers can be used in the diagnosis process for detecting a neoplastic tumor cells in peripheral blood, for contrast enhancement on magnetic resonance imaging (MRI), as well as for targeted drug delivery to tumor tissues. Agents for the targeted delivery (nanoparticles, liposomes, microcapsules, and etc) can affect the healthy tissues and organs, cause side effects and have a toxic effect. Therefore, it necessary to study the morphological changes that occur not only in the "target", such as a tumor, but also the internal organs, taking place under the influence of both the agents for targeted drug delivery and physical impact induced remote controlled drug release. Thus , the aim of our work is selection of the most promising agents for targeted drug delivery to tumor and contrast agents for in vivo visualization of tumor tissue boundaries , as well as their impact on the organs and tissues as results of nanostructured object biodistribution.

  2. A method for automatic liver segmentation from multi-phase contrast-enhanced CT images

    Science.gov (United States)

    Yuan, Rong; Luo, Ming; Wang, Shaofa; Wang, Luyao; Xie, Qingguo

    2014-03-01

    Liver segmentation is a basic and indispensable function in systems of computer aided liver surgery for volume calculation, operation designing and risk evaluation. Traditional manual segmentation is very time consuming because of the complicated contours of liver and the big amount of images. For increasing the efficiency of the clinical work, in this paper, a fully-automatic method was proposed to segment the liver from multi-phase contrast-enhanced computed tomography (CT) images. As an advanced region growing method, we applied various pre- and post-processing to get better segmentation from the different phases. Fifteen sets of clinical abdomens CT images of five patients were segmented by our algorithm, and the results were acceptable and evaluated by an experienced surgeon. The running-time is about 30 seconds for a single-phase data which includes more than 200 slices.

  3. Technical Note: Quantitative dynamic contrast-enhanced MRI of a 3-dimensional artificial capillary network.

    Science.gov (United States)

    Gaass, Thomas; Schneider, Moritz Jörg; Dietrich, Olaf; Ingrisch, Michael; Dinkel, Julien

    2017-04-01

    Variability across devices, patients, and time still hinders widespread recognition of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) as quantitative biomarker. The purpose of this work was to introduce and characterize a dedicated microchannel phantom as a model for quantitative DCE-MRI measurements. A perfusable, MR-compatible microchannel network was constructed on the basis of sacrificial melt-spun sugar fibers embedded in a block of epoxy resin. Structural analysis was performed on the basis of light microscopy images before DCE-MRI experiments. During dynamic acquisition the capillary network was perfused with a standard contrast agent injection system. Flow-dependency, as well as inter- and intrascanner reproducibility of the computed DCE parameters were evaluated using a 3.0 T whole-body MRI. Semi-quantitative and quantitative flow-related parameters exhibited the expected proportionality to the set flow rate (mean Pearson correlation coefficient: 0.991, P quantitative parameters. All evaluated parameters were well in the range of known in vivo results for the applied flow rates. The constructed phantom enables reproducible, flow-dependent, contrast-enhanced MR measurements with the potential to facilitate standardization and comparability of DCE-MRI examinations. © 2017 American Association of Physicists in Medicine.

  4. Diagnostic performance of Contrast-enhanced CT in Pyrrolizidine Alkaloids-induced Hepatic Sinusoidal Obstructive Syndrome

    Science.gov (United States)

    Kan, Xuefeng; Ye, Jin; Rong, Xinxin; Lu, Zhiwen; Li, Xin; Wang, Yong; Yang, Ling; Xu, Keshu; Song, Yuhu; Hou, Xiaohua

    2016-01-01

    Hepatic sinusoidal obstruction syndrome (HSOS) can be caused by pyrrolizidine alkaloids(PAs)-containing herbals. Since PAs exposure is obscure and clinical presentation of HSOS is unspecific, it is challenge to establish the diagnosis of PAs-induced HSOS. Gynura segetum is one of the most wide-use herbals containing PAs. The aim of our study is to describe the features of contrast-enhanced computed tomography (CT) in gynura segetum-induced HSOS, and then determine diagnostic performance of radiological signs. We retrospectively analyzed medical records and CT images of HSOS patients (71 cases) and the controls (222 cases) enrolled from January 1, 2008, to Oct 31, 2015. The common findings of contrast CT in PAs-induced HSOS included: ascites (100%), hepatomegaly (78.87%), gallbladder wall thickening (86.96%), pleural effusion (70.42%), hepatic vein narrowing (87.32%), patchy liver enhancement (92.96%), and heterogeneous hypoattenuation (100%); of these signs, patchy enhancement and heterogeneous hypoattenuation were valuable features. Then, the result of diagnostic performance demonstrated that contrast CT possessed better performance in diagnosing PAs-induced HSOS compared with various parameters of Seattle criteria. In conclusion, the patients with PAs-induced HSOS display distinct radiologic features at CT-scan, which reveals that contrast-enhanced CT provides an effective noninvasive method for diagnosing PAs-induced HSOS. PMID:27897243

  5. The characterization of small hypoattenuating renal masses on contrast-enhanced CT☆

    Science.gov (United States)

    Patel, Neesha S.; Poder, Liina; Wang, Zhen J.; Yeh, Benjamin M.; Qayyum, Aliya; Jin, Hua; Coakley, Fergus V.

    2011-01-01

    Purpose To determine if small hypoattenuating renal masses can be characterized as simple cysts or renal cell carcinomas on contrast-enhanced computed tomography (CT). Materials and methods We retrospectively identified 20 small (≤1.5 cm) hypoattenuating renal masses seen on contrast enhanced CT, consisting of 14 simple cysts and six renal cell carcinomas. Three independent readers recorded subjective visual impression (five-point scale from 1=definitely fluid to 5=definitely solid), CT attenuation, border (well circumscribed or ill defined), and shape (ovoid or irregular) for each lesion. Results The overall area under the receiver operator characteristic curves for subjective visual impression, CT attenuation, border, and shape were 0.97, 0.82, 0.59, and 0.55, respectively. Using dichotomized ratings (1–2=cyst and 3–5=carcinoma), subjective impression had a sensitivity and specificity of 100% and 79–100%, respectively, for the diagnosis of renal cell carcinoma. Using a threshold of 50 Hounsfield Units (HU) or more, CT attenuation had a sensitivity and specificity of 100% and 43–64%, respectively. Conclusion Small hypoattenuating renal masses can be characterized with reasonable accuracy by subjective impression and CT attenuation; lesions that appear solid on visual inspection or have an attenuation value of 50 HU or more are likely to be renal cell carcinoma. © 2009 Elsevier Inc. All rights reserved. PMID:19559352

  6. Contrast enhancement pattern on multidetector CT predicts malignancy in pancreatic endocrine tumours

    Energy Technology Data Exchange (ETDEWEB)

    Cappelli, Carla [University of Pisa, Diagnostic and Interventional Radiology, Department of Translational Research and New Technologies in Medicine and Surgery, Pisa (Italy); Azienda Ospedaliero-Universitaria Pisana-Radiodiagnostica I, Pisa (Italy); Boggi, Ugo [University of Pisa, General and Transplant Surgery, Department of Translational Research and New Technologies in Medicine and Surgery, Pisa (Italy); Mazzeo, Salvatore; Cervelli, Rosa; Contillo, Benedetta Pontillo; Bartolozzi, Carlo [University of Pisa, Diagnostic and Interventional Radiology, Department of Translational Research and New Technologies in Medicine and Surgery, Pisa (Italy); Campani, Daniela; Funel, Niccola [University of Pisa, Pathology, Department of Surgical, Medical, Molecular and Critical Area Pathology, Pisa (Italy)

    2014-12-02

    Preoperative suspicion of malignancy in pancreatic neuroendocrine tumours (pNETs) is mostly based on tumour size. We retrospectively reviewed the contrast enhancement pattern (CEP) of a series of pNETs on multiphasic multidetector computed tomography (MDCT), to identify further imaging features predictive of lesion aggressiveness. Sixty pNETs, diagnosed in 52 patients, were classified based on CEP as: type A showing early contrast enhancement and rapid wash-out; type B presenting even (B1) or only (B2) late enhancement. All tumours were resected allowing pathologic correlations. Nineteen pNETs showed type A CEP (5-20 mm), 29 type B1 CEP (5-80 mm) and 12 type B2 (15-100 mm). All tumours were classified as well differentiated tumours, 19 were benign (WDt-b), 15 with uncertain behaviour (WDt-u) and 26 carcinomas (WDC). None of A lesions were malignant (12 WDt-b; 7 WDt-u), all B2 lesions were WDC, 7 B1 lesions were WDt-b, 8 WDt-u and 14 WDC; 4/34 (12 %) lesions ≤2cm were WDC. CEP showed correlation with all histological prognostic indicators. Correlating with the lesion grading and other histological prognostic predictors, CEP may preoperatively suggest the behaviour of pNETs, assisting decisions about treatment. Moreover CEP allows recognition of malignant small tumours, incorrectly classified on the basis of their dimension. (orig.)

  7. Prognostic significance of contrast-enhanced CT attenuation value in extrahepatic cholangiocarcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Asayama, Yoshiki [Kyushu University, Department of Advanced Imaging and Interventional Radiology, Graduate School of Medical Sciences, Fukuoka (Japan); Nishie, Akihiro; Ishigami, Kousei; Ushijima, Yasuhiro; Takayama, Yukihisa; Okamoto, Daisuke; Fujita, Nobuhiro; Honda, Hiroshi [Kyushu University, Departments of Clinical Radiology, Fukuoka (Japan); Ohtsuka, Takao [Kyushu University, Departments of Surgery and Oncology, Fukuoka (Japan); Yoshizumi, Tomoharu [Kyushu University, Departments of Surgery and Sciences, Fukuoka (Japan); Aishima, Shinichi [Saga University, Pathology and Microbiology, Faculty of Medicine, Saga (Japan); Kyushu University, Departments of Anatomic Pathology, Graduate School of Medical Sciences, Fukuoka (Japan); Oda, Yoshinao [Kyushu University, Departments of Anatomic Pathology, Graduate School of Medical Sciences, Fukuoka (Japan)

    2017-06-15

    To determine whether washout characteristics of dynamic contrast-enhanced computed tomography (CT) could predict survival in patients with extrahepatic cholangiocarcinoma (EHC). This study collected 46 resected cases. All cases were examined by dynamic contrast study on multidetector-row CT. Region-of-interest measurements were obtained at the non-enhanced, portal venous phase and delayed phase in the tumour and were used to calculate the washout ratio as follows: [(attenuation value at portal venous phase CT - attenuation value at delayed enhanced CT)/(attenuation value at portal venous phase CT - attenuation value at unenhanced CT)] x 100. On the basis of the median washout ratio, we classified the cases into two groups, a high-washout group and low-washout group. Associations between overall survival and various factors including washout rates were analysed. The median washout ratio was 29.4 %. Univariate analysis revealed that a lower washout ratio, venous invasion, lymphatic permeation and lymph node metastasis were associated with shorter survival. Multivariate analysis identified the lower washout ratio as an independent prognostic factor (hazard ratio, 3.768; p value, 0.027). The washout ratio obtained from the contrast-enhanced CT may be a useful imaging biomarker for the prediction of survival of patients with EHC. (orig.)

  8. Contrast-enhanced ultrasound with SonoVue in the evaluation of postoperative complications in pediatric liver transplant recipients

    Science.gov (United States)

    Bonini, G.; Pezzotta, G.; Morzenti, C.; Agazzi, R.; Nani, R.

    2007-01-01

    Purpose To evaluate the utility of contrast-enhanced sonography in the study of pediatric liver transplant recipients and its potential impact in reducing the need for invasive diagnostic procedures. Materials and methods From October 2002 to December 2003 we performed routine color Doppler ultrasound and contrast-enhanced ultrasound studies on 30 pediatric patients who had undergone liver transplantation. Findings indicative of complications were confirmed with invasive studies (angiography, computed tomography, and PTC). Results Contrast-enhanced sonography correctly identified four of the five cases of hepatic artery thrombosis and all those involving the portal (n = 6) and hepatic vein (n = 3) thrombosis. It failed to identify one case of hepatic artery thrombosis characterized by collateral circulation arising from the phrenic artery and the single case of hepatic artery stenosis. The latter was more evident on color Doppler, which revealed a typical tardus parvus waveform. The use of contrast offered no significant advantages in the study of biliary complications although it did provide better visualization of bile leaks. Conclusions Contrast-enhanced sonography improves diagnostic confidence and reduces the need for more invasive imaging studies in the postoperative follow-up of pediatric liver transplant recipients. PMID:23396596

  9. Contrast-enhanced ultrasound of hepatocarcinogenesis in liver cirrhosis

    Institute of Scientific and Technical Information of China (English)

    WU Wei; CHEN Min-hua; SUN Maryellen; YAN Kun; YANG Wei; LI Ji-you

    2012-01-01

    Background Hepatocellular carcinoma (HCC) often occurs in association with liver cirrhosis.A stepwise carcinogenesis for HCC has been proposed.The purpose of this study was to observe the enhancement pattern of hepatocellular nodules in cirrhotic patients using contrast-enhanced ultrasound (CEUS) and to correlate patterns of enhancement at CEUS with the diagnosis of hepatocellular nodules using pathologic correlation as the gold standard.Methods Ninety-three cirrhotic patients with indeterminate hepatocellular nodules at ultrasound,underwent biopsy of each indeterminate nodule.Patients with nodules found to have pathologic diagnoses of regenerative nodules (RNs),dysplastic nodules (DNs),or DNs with focus of HCC (DN-HCC),were enrolled in this study.Enhancement patterns of all nodules were examined throughout the various vascular phases of CEUS and classified into five enhancement patterns:type Ⅰ,isoenhancement to hepatic parenchyma at all phases; type Ⅱ,hypoenhancement in the arterial phase,and isoenhancement in the portal venous phase and late phase; type Ⅲ,iso-to-hypoenhancement in arterial and portal venous phase,and hypoenhancement in the late phase (washout); type Ⅳ,slight hyperenhancement in the arterial and portal venous phase and hypoenhancement in the late phase (washout); and type Ⅴ,partial hyperenhancement in the arterial phase and hypoenhancement in the late phase; and another partial iso-to-hypoenhancement in the arterial and portal venous phase and hypoenhancement in the late phase (washout).The correlation between the contrast enhancement patterns and the pathological diagnoses was analyzed by the chi-squared test.Results Totally 132 lesions were examined with CEUS in 93 patients.Pathologic diagnoses included 45 DN,68 RN,and 19 DN-HCC.The enhancement patterns observed were as follows:type Ⅰ,49 (37.1%); type Ⅱ,27 (20.5%); type Ⅲ,28(21.2%); type Ⅳ,9 (6.8%); type Ⅴ,19 (14.4%).Nodules with type Ⅰ enhancement showed

  10. Polycystic ovary syndrome: dynamic contrast-enhanced ovary MR imaging

    Energy Technology Data Exchange (ETDEWEB)

    Erdem, C. Zuhal E-mail: sunarerdem@yahoo.com; Bayar, Ulku; Erdem, L. Oktay; Barut, Aykut; Gundogdu, Sadi; Kaya, Erdal

    2004-07-01

    Objective: to determine the enhancement behaviour of the ovaries in women with polycystic ovary syndrome (PCOS) by dynamic contrast-enhanced magnetic resonance (DCE-MR) imaging and to compare these data with those of normal ovulating controls. Method: 24 women with PCOS and 12 controls underwent DCE-MR imaging. Dynamic images were acquired before and after injection of a contrast bolus at 30 s and the min of 1, 2, 3, 4 and 5. On postprocessing examination: (i) the ovarian volumes; (ii) the signal intensity value of each ovary per dynamic study; (iii) early-phase enhancement rate; (iv) time to peak enhancement (T{sub p}); and (v) percentage of washout of 5th min were determined. Data of the ovaries of the women with PCOS and controls were compared with Mann-Whitney U-test. Results: the mean values of T{sub p} were found to be significantly lower in women with PCOS than in controls (p<0.05). On the other hand, the mean values of ovarian volume, the early-phase enhancement rate, and percentage of washout of 5th min of ovaries were significantly higher in PCOS patients (p<0.05). Examination of the mean signal intensity-time curve revealed the ovaries in women with PCOS showed a faster and greater enhancement and wash-out. Conclusion: the enhancement behaviour of ovaries of women with PCOS may be significantly different from those of control subjects on DCE-MR imaging examination. In our experience, it is a valuable modality to highlight the vascularization changes in ovarian stroma with PCOS. We believe that improved DCE-MR imaging techniques may also provide us additional parameters in the diagnosis and treatment strategies of PCOS.

  11. Contrast-enhanced peripheral MRA. Technique and contrast agents

    Energy Technology Data Exchange (ETDEWEB)

    Nielsen, Yousef W. [Dept. of Radiology, Copenhagen Univ. Hospital Bispebjerg, Bispebjerg (Denmark)], e-mail: ywnielsen@gmail.com; Thomsen, Henrik S. [Dept. of Diagnostic Radiology, Copenhagen Univ. Hospital Herlev, Herlev (Denmark)

    2012-09-15

    In the last decade contrast-enhanced magnetic resonance angiography (CE-MRA) has gained wide acceptance as a valuable tool in the diagnostic work-up of patients with peripheral arterial disease. This review presents current concepts in peripheral CE-MRA with emphasis on MRI technique and contrast agents. Peripheral CE-MRA is defined as an MR angiogram of the arteries from the aortic bifurcation to the feet. Advantages of CE-MRA include minimal invasiveness and lack of ionizing radiation. The basic technique employed for peripheral CE-MRA is the bolus-chase method. With this method a paramagnetic MRI contrast agent is injected intravenously and T1-weighted images are acquired in the subsequent arterial first-pass phase. In order to achieve high quality MR angiograms without interfering venous contamination or artifacts, a number of factors need to be taken into account. This includes magnetic field strength of the MRI system, receiver coil configuration, use of parallel imaging, contrast bolus timing technique, and k-space filling strategies. Furthermore, it is possible to optimize peripheral CE-MRA using venous compression techniques, hybrid scan protocols, time-resolved imaging, and steady-state MRA. Gadolinium(Gd)-based contrast agents are used for CE-MRA of the peripheral arteries. Extracellular Gd agents have a pharmacokinetic profile similar to iodinated contrast media. Accordingly, these agents are employed for first-pass MRA. Blood-pool Gd-based agents are characterized by prolonged intravascular stay, due to macromolecular structure or protein binding. These agents can be used for first-pass, as well as steady-state MRA. Some Gd-based contrast agents with low thermodynamic stability have been linked to development of nephrogenic systemic fibrosis in patients with severe renal insufficiency. Using optimized technique and a stable MRI contrast agent, peripheral CE-MRA is a safe procedure with diagnostic accuracy close to that of conventional catheter X

  12. Cumulative phase delay imaging - A new contrast enhanced ultrasound modality

    Energy Technology Data Exchange (ETDEWEB)

    Demi, Libertario, E-mail: l.demi@tue.nl; Sloun, Ruud J. G. van; Mischi, Massimo [Lab. of Biomedical Diagnostics, Dept. of Electrical Eng., Eindhoven University of Technology (Netherlands); Wijkstra, Hessel [Lab. of Biomedical Diagnostics, Dept. of Electrical Eng., Eindhoven University of Technology (Netherlands); Academic Medical Center, Urology Dept., University of Amsterdam (Netherlands)

    2015-10-28

    Recently, a new acoustic marker for ultrasound contrast agents (UCAs) has been introduced. A cumulative phase delay (CPD) between the second harmonic and fundamental pressure wave field components is in fact observable for ultrasound propagating through UCAs. This phenomenon is absent in the case of tissue nonlinearity and is dependent on insonating pressure and frequency, UCA concentration, and propagation path length through UCAs. In this paper, ultrasound images based on this marker are presented. The ULA-OP research platform, in combination with a LA332 linear array probe (Esaote, Firenze Italy), were used to image a gelatin phantom containing a PVC plate (used as a reflector) and a cylindrical cavity measuring 7 mm in diameter (placed in between the observation point and the PVC plate). The cavity contained a 240 µL/L SonoVueO{sup ®} UCA concentration. Two insonating frequencies (3 MHz and 2.5 MHz) were used to scan the gelatine phantom. A mechanical index MI = 0.07, measured in water at the cavity location with a HGL-0400 hydrophone (Onda, Sunnyvale, CA), was utilized. Processing the ultrasound signals backscattered from the plate, ultrasound images were generated in a tomographic fashion using the filtered back-projection method. As already observed in previous studies, significantly higher CPD values are measured when imaging at a frequency of 2.5 MHz, as compared to imaging at 3 MHz. In conclusion, these results confirm the applicability of the discussed CPD as a marker for contrast imaging. Comparison with standard contrast-enhanced ultrasound imaging modalities will be the focus of future work.

  13. TMJ disorders and pain: Assessment by contrast-enhanced MRI

    Energy Technology Data Exchange (ETDEWEB)

    Farina, Davide [Department of Radiology (School of Medicine), University of Brescia, Piazzale Spedali Civili 1, 25123 Brescia (Italy)], E-mail: nappaje@yahoo.it; Bodin, Christiane [Division of Gnathology (School of Dentistry), University of Brescia, Piazzale Spedali Civili 1, 25123 Brescia (Italy); Gandolfi, Silvia [Department of Radiology (School of Medicine), University of Brescia, Piazzale Spedali Civili 1, 25123 Brescia (Italy); De Gasperi, Werner [Division of Gnathology (School of Dentistry), University of Brescia, Piazzale Spedali Civili 1, 25123 Brescia (Italy); Borghesi, Andrea; Maroldi, Roberto [Department of Radiology (School of Medicine), University of Brescia, Piazzale Spedali Civili 1, 25123 Brescia (Italy)

    2009-04-15

    Though magnetic resonance (MRI) is a widely accepted standard for the assessment of patients with temporomandibular joint (TMJ) disorders, efforts to correlate symptoms to MRI findings have often given controversial results. Aim of this study was to investigate the correlation between TMJ pain and findings of contrast-enhanced MRI. Thirty-eight consecutive patients with TMJ dysfunction syndrome (study group) were examined with MRI. Protocol included T2 turbo spin-echo sequence, T1 spin-echo sequence, and T2 gradient-echo (acquired with closed jaw, at intermediate and maximal opening). Post-contrast phase was obtained through a fat sat 3D T1 gradient-echo sequence (VIBE). Post-contrast findings in the study group were matched with those obtained in a control group of 33 patients submitted to MRI of the paranasal sinuses. Statistically significant difference was found between condylar medullary bone enhancement in painful TMJ, in painless TMJ and control group. In addition the average thickness of joint soft tissue enhancement in painful TMJ was superior to painless TMJ (p < 0.0001) and to control group. On multivariate logistic regression analysis, the odds ratio that a painful TMJ showed disk displacement, osteoarthrosis, effusion and JST enhancement were 3.05, 3.18, 1.2 and 11.36, respectively. Though not histologically proven, TMJ enhancement could reflect the presence of inflammation in painful joints. Furthermore, the administration of contrast could be of help for the assessment of patients with orofacial pain, particularly when clinical exploration is insufficient to ascribe the pain to TMJ.

  14. A simulation tool for dynamic contrast enhanced MRI.

    Directory of Open Access Journals (Sweden)

    Nicolas Adrien Pannetier

    Full Text Available The quantification of bolus-tracking MRI techniques remains challenging. The acquisition usually relies on one contrast and the analysis on a simplified model of the various phenomena that arise within a voxel, leading to inaccurate perfusion estimates. To evaluate how simplifications in the interstitial model impact perfusion estimates, we propose a numerical tool to simulate the MR signal provided by a dynamic contrast enhanced (DCE MRI experiment. Our model encompasses the intrinsic R1 and R2 relaxations, the magnetic field perturbations induced by susceptibility interfaces (vessels and cells, the diffusion of the water protons, the blood flow, the permeability of the vessel wall to the the contrast agent (CA and the constrained diffusion of the CA within the voxel. The blood compartment is modeled as a uniform compartment. The different blocks of the simulation are validated and compared to classical models. The impact of the CA diffusivity on the permeability and blood volume estimates is evaluated. Simulations demonstrate that the CA diffusivity slightly impacts the permeability estimates (< 5% for classical blood flow and CA diffusion. The effect of long echo times is investigated. Simulations show that DCE-MRI performed with an echo time TE = 5 ms may already lead to significant underestimation of the blood volume (up to 30% lower for brain tumor permeability values. The potential and the versatility of the proposed implementation are evaluated by running the simulation with realistic vascular geometry obtained from two photons microscopy and with impermeable cells in the extravascular environment. In conclusion, the proposed simulation tool describes DCE-MRI experiments and may be used to evaluate and optimize acquisition and processing strategies.

  15. Contrast-enhanced ultrasound for liver imaging: recent advances.

    Science.gov (United States)

    Salvatore, Veronica; Borghi, Alberto; Piscaglia, Fabio

    2012-01-01

    Contrast-enhanced ultrasonography (CEUS), providing relevant informations not available with non-enhanced ultrasonography, greatly impacted the practice of liver imaging. The characterization of focal liver lesions (FLLs), is obtained in a rapid, accurate and safe way and is considered the main hepatic indication; however CEUS offers other established or emergent relevant applications. Metastases detection and assessment of response to locoregional tumor treatment are accepted applications with specific indications. Needle guidance in case of poorly or non visible target lesions at conventional ultrasound is also accepted. The early assessment of response to systemic treatment, and in particular to antiangiogenic ones, by quantification software is an emergent application. The manageability of CEUS determined also its use in the operating theatre, improving the accuracy of intraoperatory US with a significant impact on final surgical strategy. In cirrhotic patients, the role of CEUS was proven highly accurate and sensitive in the characterization of portal vein thrombosis, by identification of contrast arterial enhancement inside the thrombus, that occurs only in case of neoplastic origin. In recent years microbubbles taken up by Kupffer cells, thus possessing a "postvascular" phase, were registered as ultrasound contrast agent in Japan (Sonazoid). During the post-vascular phase tumoral tissue tend to appear as a contrast defect image due to the lack of Kupffer cells, strongly contributing to tumor staging beside characterization. Newly developed techniques, such as fusion imaging or real-time three dimensional US, in addition to other applications of CEUS, in terms of post-transplantation or cholecystitis-related complications, have been recently proposed and will be discussed.

  16. Assessing Tumor Response to Treatment in Patients with Lung Cancer Using Dynamic Contrast-Enhanced CT

    DEFF Research Database (Denmark)

    Strauch, Louise S; Eriksen, Rie Ø; Sandgaard, Michael

    2016-01-01

    after treatment. Four out of five studies that measured blood flow post anti-angiogenic treatments found that blood flow was significantly decreased. DCE-CT may be a useful tool in assessing treatment response in patients with lung cancer. It seems that particularly permeability and blood flow......The aim of this study was to provide an overview of the literature available on dynamic contrast-enhanced computed tomography (DCE-CT) as a tool to evaluate treatment response in patients with lung cancer. This systematic review was compiled according to Preferred Reporting Items for Systematic...... Reviews and Meta-Analyses (PRISMA) guidelines. Only original research articles concerning treatment response in patients with lung cancer assessed with DCE-CT were included. To assess the validity of each study we implemented Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2). The initial search...

  17. Contrast-enhanced ultrasound for the evaluation of acute renal infarction.

    Science.gov (United States)

    Miyoshi, Toru; Okayama, Hideki; Hiasa, Go; Kawata, Yoshitaka; Yamada, Tadakatsu; Kazatani, Yukio

    2016-01-01

    A 65-year-old male in the dilated phase of hypertrophic cardiomyopathy and with persistent atrial fibrillation was admitted to our hospital because of an episode of ventricular fibrillation following an appropriate shock from an implantable cardiac defibrillator (ICD). At admission, electrocardiography showed a normal sinus rhythm. He had complained of back pain 7 days after the ICD shock. Renal infarction was suspected, although computed tomography and magnetic resonance imaging could not be performed because of chronic renal failure and the presence of his ICD. We, therefore, used contrast-enhanced ultrasonography with a contrast agent to evaluate his acute kidney injury. This showed the left kidney contained a wedge-shaped area that was not enhanced by the contrast agent, indicating an area of infarction.

  18. Automated Detection of Healthy and Diseased Aortae from Images Obtained by Contrast-Enhanced CT Scan

    Directory of Open Access Journals (Sweden)

    Michael Gayhart

    2013-01-01

    Full Text Available Purpose. We developed the next stage of our computer assisted diagnosis (CAD system to aid radiologists in evaluating CT images for aortic disease by removing innocuous images and highlighting signs of aortic disease. Materials and Methods. Segmented data of patient’s contrast-enhanced CT scan was analyzed for aortic dissection and penetrating aortic ulcer (PAU. Aortic dissection was detected by checking for an abnormal shape of the aorta using edge oriented methods. PAU was recognized through abnormally high intensities with interest point operators. Results. The aortic dissection detection process had a sensitivity of 0.8218 and a specificity of 0.9907. The PAU detection process scored a sensitivity of 0.7587 and a specificity of 0.9700. Conclusion. The aortic dissection detection process and the PAU detection process were successful in removing innocuous images, but additional methods are necessary for improving recognition of images with aortic disease.

  19. Value of multi-detector CT angiography in Takayasu arteritis%多排螺旋CT对多发性大动脉炎的诊断价值

    Institute of Scientific and Technical Information of China (English)

    陈海雄; 胡秋根; 李景雷

    2014-01-01

    目的 探讨多排螺旋CT(MDCT)在多发性大动脉炎中的诊断价值。方法 回顾性分析32 例经临床确诊为大动脉炎患者的MDCT 资料及实验室检查,图像后处理方法包括多平面重建(MPR)、曲面重建(CPR)、最大密度投影(MIP)、容积再现(VR),实验室检查主要包括红细胞沉降率(ESR)和C 反应蛋白(CRP)。结果 按照Lupi-Herrea 分类法,Ⅰ型10 例,Ⅱ型9 例,Ⅲ型8 例,Ⅳ型5 例;共累及血管134 支,狭窄- 阻塞型112 支;扩张型8 支;混合型14 支。受累血管管壁最大厚度范围为1.3~8.6 mm(平均3.65±1.58),活动期管壁最大厚度约2.7~8.6 mm(平均5.24±1.59),明显大于非活动期1.3~6.0 mm (平均2.93±0.92)(P<0.05)。增强扫描活动期管壁强化8 例(80.0%),非活动期管壁轻度强化2 例(9.0%),非活动期管壁钙化 7 例(31.8%)。结论 MDCT 能准确判断多发性大动脉炎的分型、分期及病变范围,可作为其首选检查方法。%ObjectiveTo investigate the clinical value of multi-detector computed tomography(MDCT)in the diagnosis of Takayasu's arteritis.Methods MDCT, erythrocyte sedimentation rate(ESR)and C-reactive protein(CRP)levels of 32 patients with Takayasu’s arteritis were analyzed retrospectively. Image processing included multi-planar reformation(MPR), maximum intensity projection (MIP), and volume rendering reconstruction(VR).Results The patients were classified Lupi-Herrea type I(10), type II(9), type III(8) and type IV(5). Of 134 abnormal vessels, 112 were stenotic or occlusive, 8 were dilated and 14 were mixed. The vessel wall thickness was 1.3-8.6 mm(average 3.65±1.58 mm)with significantly(P<0.05)thicker walls in the active phase(2.7-8.6 mm)than that in the resting phase(1.3-6.0 mm). There was heterogeneous contrast enhancement of the vessel walls in the active phase(80.0%), mild enhancement(9.0%)and calcification (31.8%)in the resting

  20. Differentiation of dysplastic nodule from hepatocellular carcinoma on contrast-enhanced power and pulsed Doppler US

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Jung Hee; Baek, Seung Yon; Kang, Byung Chul; Chung, Hye Kyung [Ewha Womans University College of Medicine, Seoul (Korea, Republic of)

    2001-09-15

    The purpose of this study was to differentiate dysplastic (DN) from hepatocellular carcinoma (HCC) in patients with liver cirrhosis on contrast-enhanced power and pulsed Doppler US. Twenty-one patients with liver cirrhosis and a focal lesion were included. They consisted of biopsy proven 12 DNs (mean diameter; 1.8 cm, M : F = 5 :7, mean age 60) and 9 HCCs (mean diameter: 2.3 cm, M : F = 6 : 3,mean age 63). All the patients were prospectively examined with Acusion Computed Sonography 128XP/10 and 4 MHz vector transducer. Gray-scale US was done to assess the echogenicity of the focal lesion. Vascular flow signals within the focal lesion were examined with power Doppler US. After the injection of 7 ml (300 mg/ml) suspension of US contrast agent (Levovist, Schering, Berlin, Germary), vascular flow signals were graded to 4 grades on power Doppler US. Arterial and/or venous flow pattern on pulsed Doppler US were evaluated. Statistical analysis was done using chi-square method. On gray-scale US, 10 (83%) DNs showed hypoechogenicity and the other two (17%) showed hyperechogenicity 7 (78%) HCCs were hypoechoic and two (22%) were hyperechoic. On non-enhanced power Doppler US, all 12 cases (100%) of DNs had no vascular flow signal and four cases of nine HCCs (grade II: three, grade III: one) revealed vascular flow signals (p=0.429). On contrast-enhanced power Doppler US, 11 cases(92%) of DNs and all cases (100%) of HCCs showed increased vascular flow signals. Three (24%) of DNs and 7 (78%) of HCCs showed grade III and IV. There was a statistical difference in the grade of vascular flow signals between two groups (p=0.03). On pulsed Doppler US, the arterial flow was present in 2 (17%) DNs and 8 (89%) HCCs (p=0.002) and venous flow was present in 11 (92%) DNs and 5 (56%) HCCs. Combined flow appeared in 2 cases (16%) of DNs and 4 cases (44%) of HCCs. In differentiating DN from HCC, the higher probability of HCC can be considered if a focal lesion in cirrhotic patients has grade

  1. Diagnositc value of 3D-gradient echo dynamic contrast enhanced MRI in breast cancer

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Ik; Chung, Soo Young; Park, Hai Jung; Lee, Yul; Chung, Bong Wha; Shim, Jeong Won [Hallym Univ. College of Medicine, Seoul (Korea, Republic of)

    1997-10-01

    To assess the usefulness of 3D-gradient echo dynamic contrast enhanced MRI (3D-DMRI) in the diagnosis of breast cancer and to determine the most useful parameter for this diagnosis. Using a 1.0T MR unit, (Magnetom, Siemens, Erlaugen, Germany), 3D-DMRI (TR/TE=3D30/12) with Gd-DTPA was performed in 38 cases of breast cancer, 22 of fibroadenoma, and in three normal volunteers. We retrospectively evaluated the findings according to the speed on dynamic study and maximal amount of contrast enhancement during the delayed phase;we calculated the contrast index and morphology of the cancers and compared diagnostic accuracy among these three diagnostic parameters. On conventional spin-echo T1-and T2-weighted images, there was no significant difference of signal intensity between benign fibroadenoma and breast carcinoma. Rapid contrast enhancement (within one minute) was noted in 35 breast cancer lesions (92.1%), but relatively low and slow contrast enhancement (after five minutes) was noted in three such lesions (7.9%). Gradual contrast enhancement was noted in 21 lesions of fibroadenoma(95.5%), but a moderate degree of rapid contrast enhancement (from three to five minutes) was noted in the other case (7.9%). of On the delayed enhanced phase of 3D-DMRI, the maximal amount of contrast enhancement showed no significant difference between fibroadenoma and cancer. On 3D-DMRI, an irregular, spiculated border, with high contrast enhancement was noted in all cases of breast cancer, in particular, irregular thick peripheral contrast enhancement with central necrosis was noted 11cases(28.9%). For the diagnosis of breast cancer, 3D-DMRI is a useful technique. Among the diagnostic criteria of speed, maximal amount of contrast enhancement and morphology, morphologic change after contrast enhancement study was the most useful diagnostic parameter.=20.

  2. Contrast-enhanced flair imaging in the evaluation of infectious leptomeningeal diseases

    Energy Technology Data Exchange (ETDEWEB)

    Parmar, Hemant [Department of Neuroradiology, National Neuroscience Institute, 11 Jalan Tan Tock Seng, Singapore 308433 (Singapore) and Department of Diagnostic Imaging, Hospital for Sick Children, Toronto (Canada)]. E-mail: parurad@hotmail.com; Sitoh, Y.-Y. [Department of Neuroradiology, National Neuroscience Institute, 11 Jalan Tan Tock Seng, Singapore 308433 (Singapore); Anand, Pooja [Department of Neurology, National Neuroscience Institute, 11 Jalan Tan Tock Seng (Singapore); Chua, Violet [Department of Neuroradiology, National Neuroscience Institute, 11 Jalan Tan Tock Seng, Singapore 308433 (Singapore); Hui, Francis [Department of Neuroradiology, National Neuroscience Institute, 11 Jalan Tan Tock Seng, Singapore 308433 (Singapore)

    2006-04-15

    Purpose: The purpose of our study was to compare contrast-enhanced fluid-attenuated inversion recovery (FLAIR) images with contrast-enhanced T1 weighted images for infectious leptomeningitis. Materials and methods: We studied twenty-four patients with a clinical suspicion of infectious meningitis with unenhanced FLAIR, contrast-enhanced T1 weighted and contrast-enhanced FLAIR MR sequences. Twelve patients had cytologic and biochemical diagnosis of meningitis on cerebrospinal fluid (CSF) examination obtained 48 h before or after the MR study. Sequences were considered positive if abnormal signal was seen in the subarachnoid space (cistern or sulci) or along pial surface. Results: Twenty-seven examinations in 24 patients were performed. Of the 12 patients (thirteen studies) in whom cytology was positive, unenhanced FLAIR images were positive in six cases (sensitivity 46%), contrast-enhanced FLAIR images were positive in 11 (sensitivity 85%), and contrast-enhanced T1 weighted MR images were positive in 11 patients (sensitivity 85%). Of the 12 patients (14 studies) in whom cerebrospinal fluid study was negative, unenhanced FLAIR images were negative in 13, contrast-enhanced FLAIR images were negative in 11, and contrast-enhanced T1 weighted MR images were negative in eight. Thus, the specificity of unenhanced FLAIR, contrast-enhanced FLAIR and contrast-enhanced T1 weighted images was 93, 79 and 57%, respectively. Conclusion: Our results suggest that post-contrast FLAIR images have similar sensitivity but a higher specificity compared to contrast-enhanced T1 weighted images for detection of leptomeningeal enhancement. It can be a useful adjunct to post-contrast T1 weighted images in evaluation of infectious leptomeningitis.

  3. Non-contrast-enhanced MR angiography for detecting arteriovenous fistula dysfunction in haemodialysis patients.

    Science.gov (United States)

    Jin, W T; Zhang, G F; Liu, H C; Zhang, H; Li, B; Zhu, X Q

    2015-08-01

    To assess the diagnostic value of non-contrast-enhanced magnetic resonance angiography (NCE-MRA), using time-of-flight and black-blood MRA, in the evaluation of arteriovenous fistulas in haemodialysis patients in comparison to multidetector computed tomography angiography (MDCTA). NCE-MRA and MDCTA were performed on the same day in 21 patients on maintenance haemodialysis with dysfunctional arteriovenous fistulas. The fistulas included three segments: arterial inflow, anastomosis, and venous outflow. Two experienced observers, who were blinded to the results of the NCE-MRA, recorded in consensus the significant stenoses (≥50%) seen on CTA. Two other experienced observers, unaware of the results of CTA, independently recorded significant stenoses (≥50%) in the NCE-MRA. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of NCE-MRA were calculated, with MDCTA as the standard reference. Sixty-three vascular segments in the 21 patients were clearly displayed. For the two observers of NCE-MRA, the accuracy was 98% and 95.4%; sensitivity 96.4% and 96.4%; specificity 97.1% and 94.3%; positive predictive value 96.4% and 93.1%; and, negative predictive value 97.1% and 97.1%. Inter-/intra-observer agreement for detecting stenosis was excellent for NCE-MRA, with a weighted kappa of 0.968 (95% confidence interval [CI], 0.874-1) and 0.936 (95% CI, 0.848-1). Non-contrast-enhanced MRA, using time-of-flight and black-blood MRA, is a reproducible and reliable imaging technique for detecting ≥50% stenosis in dysfunctional haemodialysis arteriovenous fistulas. Copyright © 2015 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.

  4. Quantitative Investigation of Solitary Pulmonary Nodules with Dynamic Contrast-Enhanced Functional CT

    Institute of Scientific and Technical Information of China (English)

    MinmingZhang; HuaZhou; YuZou

    2004-01-01

    OBJECTIVE To evaluate solitary pulmonary nodules (SPNs) using quantitative-dynamic contrast-enhancedfunctional-computed tomography(CT); and to illustrate its clinical efficacy in differential diagnosis of benign and malignant pulmonary nodules.METHODS Eighty patients with non-calcified SPNs (diameter, 5-30mm) were studied with dynamic contrast-enhanced CT. Patterns of the time-density curves (TDC) were assessed. The precontrast density, peak height in density (PH: the maximum value of the TDC) and S/A ratio (the ratio of the PH of SPN to aorta) were recorded. Precontrast density and enhancement patterns of SPNs were also recorded. Perfusion of the SPNs was calculated.RESULTS Malignant, benign and inflammatory nodules showed quite different patterns in the TDC. The PH and S/A ratios of the malignant and inflammatory nodules were significantly higher than that of the benig nnodules (P<0.001; P<0.001), while no statistical difference of either the PH or S/A ratio was found between the malignant and inflammatory nodules. Precontrast density of the inflammatory nodules was lower than that of the malignant nodules (P <0.05). Both the malignant and inflammatory nodules showed significantly higher perfusions than that of the benign nodules (P<0.01; P<0.01). However, the difference between the peffusion of the malignant nodules and inflammatory nodules was not significant.CONCLUSION Dynamic contrast-enhanced functional CT can provide quantitative information regarding blood flow patterns of SPNs and proved to be an alternate non-invasive option in the evaluation and management of solitary pulmonary nodules.

  5. Contrast-enhanced ultrasound (CEUS) in nephrology: Has the time come for its widespread use?

    Science.gov (United States)

    Granata, Antonio; Zanoli, Luca; Insalaco, Monica; Valentino, Massimo; Pavlica, Pietro; Di Nicolò, Pier Paolo; Scuderi, Mario; Fiorini, Fulvio; Fatuzzo, Pasquale; Bertolotto, Michele

    2015-08-01

    Grey-scale ultrasound has an important diagnostic role in nephrology. The absence of ionizing radiations and nephrotoxicity, rapidity of execution, excellent repeatability, the possibility to perform the test at the patient's bed and the low cost represent important advantages of this technique. Paired with real-time sonography and colour-power-Doppler contrast-enhanced ultrasound (CEUS) reduces the diagnostic gap with computed tomography (CT) and magnetic resonance (MR) and represents a major step in the evolution of clinical ultrasound. Although there are several situations in which contrast-enhanced CT and MR are indicated (i.e. evaluation of cystic or ischemic lesions, traumatisms and ablative therapies of the native and transplanted kidney), the use of CT contrast media presents a high risk of contrast-induced nephropathy (i.e. in elderly people, subjects with comorbidities and those with renal dysfunction), while gadolinium-based RM contrast agents are contraindicated for the risk of nephrogenic systemic fibrosis (i.e. in patients with severe renal dysfunction). In these situations, CEUS may be a viable alternative, however, as any technique associated with the infusion of pharmacological substances, the potential advantages and risks of CEUS should be critically evaluated. In this regard, the European Federation of Societies for Ultrasound in Medicine and Biology (EFSUMB) has published the guidelines for the use of CEUS for the kidney imaging and the International Contrast Ultrasound Society (ICUS) has been recently founded. The aim of this review is to offer an updated overview of the potential applications of CEUS in nephrology, reporting some indications and possible risks associated to its use.

  6. Study of statistical properties of hybrid statistic in coherent multi-detector CBC Search

    CERN Document Server

    Haris, K

    2015-01-01

    In this article, we revisit the problem of coherent multi-detector search of gravitational wave from compact binary coalescence with Neutron stars and Black Holes using advanced interferometers like LIGO-Virgo. Based on the loss of optimal multi-detector signal-to-noise ratio (SNR), we construct a hybrid statistic as a best of maximum-likelihood-ratio(MLR) statistic tuned for face-on and face-off binaries. The statistical properties of the hybrid statistic is studied. The performance of this hybrid statistic is compared with that of the coherent MLR statistic for generic inclination angles. Owing to the single synthetic data stream, the hybrid statistic gives low false alarms compared to the multi-detector MLR statistic and small fractional loss in the optimum SNR for a large range of binary inclinations. We have demonstrated that for a LIGO-Virgo network and binary inclination, \\epsilon 110 deg., the hybrid statistic captures more than 98% of network optimum matched filter SNR with low false alarm rate. The...

  7. Microwave ablation of liver metastases guided by contrast-enhanced ultrasound

    DEFF Research Database (Denmark)

    Lorentzen, T; Skjoldbye, B O; Nolsoe, C P

    2011-01-01

    The aim of our study was to evaluate the efficacy of microwave (MW) ablation of liver metastases guided by B-mode ultrasound (US) and contrast-enhanced US (CEUS).......The aim of our study was to evaluate the efficacy of microwave (MW) ablation of liver metastases guided by B-mode ultrasound (US) and contrast-enhanced US (CEUS)....

  8. Contrast-enhanced power Doppler ultrasonography of the metacarpophalangeal joints in rheumatoid arthritis

    DEFF Research Database (Denmark)

    Szkudlarek, Marcin; Court-Payen, Michel; Strandberg, Charlotte;

    2003-01-01

    The aim of this study was to examine, with dynamic contrast-enhanced MRI as the reference, if contrast-enhanced power Doppler ultrasonography (CE PDUS) of rheumatoid arthritis (RA) metacarpophalangeal (MCP) joints provides additional information for evaluation of synovial inflammation compared...... additional information in selected cases but did not in the present study increase the sensitivity of the method...

  9. Contrast-enhanced ultrasound in non-operative management of pancreatic injury in childhood

    Energy Technology Data Exchange (ETDEWEB)

    Valentino, Massimo; Sartoni Galloni, Stefania; Rimondi, Maria Rita; Barozzi, Libero [University Hospital S. Orsola-Malpighi, Emergency Department, Bologna (Italy); Gentili, Andrea [University Hospital S. Orsola-Malpighi, Department of Anaesthesia and Intensive Care, Bologna (Italy); Lima, Mario [University Hospital S. Orsola-Malpighi, Department of Paediatrics, Bologna (Italy)

    2006-06-15

    We report a 5-year-old child with pancreatic trauma from a blunt abdominal injury that was monitored with contrast-enhanced sonography. Unenhanced US failed to demonstrate the abnormality that was recognized by CT and MRI. The injury was well demonstrated by contrast-enhanced US which was therefore used for follow-up until its healing. (orig.)

  10. Contrast-enhanced MR angiography of cavopulmonary connections in adult patients with congenital heart disease.

    Science.gov (United States)

    Wagner, Moritz; Nguyen, Kim-Lien; Khan, Sarah; Mirsadraee, Saeed; Satou, Gary M; Aboulhosn, Jamil; Finn, J Paul

    2012-11-01

    The purpose of this study is to evaluate combined time-resolved and high-spatial resolution contrast-enhanced MR angiography (MRA) for assessment of cavopulmonary connections in adult patients with congenital heart disease. Twenty-eight adults with various surgical cavopulmonary connections (Glenn shunt and Fontan connection) underwent high-spatial-resolution contrast-enhanced MRA (voxel size, 1.95 mm(3); temporal resolution, 22 seconds) and time-resolved contrast-enhanced MRA (voxel size, 6.5-9.3 mm(3); temporal resolution, contrast-enhanced MRA) and pulmonary artery (PA) perfusion patterns (using time-resolved contrast-enhanced MRA). High-spatial-resolution contrast-enhanced MRA yielded diagnostic-quality images for morphologic assessment of cavopulmonary connections in 27 of 28 (96%) patients. The anatomic dimensions (cross-sectional area) of the PA and cavopulmonary connections showed a wide variation (right PA, 0.99-5.67 cm(2); left PA, 0.80-5.69 cm(2); Glenn shunt, 0.93-6.94 cm(2); and Fontan connection, 1.25-6.67 cm(2)). The anatomic dimensions could be assessed with excellent interobserver agreement on high-spatial-resolution contrast-enhanced MRA (r = 0.895). Time-resolved contrast-enhanced MRA yielded diagnostic-quality images in all patients and enabled characterization of PA perfusion via the superior vena cava as follows: preferential inflow to the right PA (n = 12), preferential inflow to the left PA (n = 5), and balanced inflow to the right and left PA (n = 11). In those patients who had technically successful flow quantification measurements, phase contrast data confirmed patency of the cavopulmonary connections. Combined time-resolved contrast-enhanced MRA and high-spatial-resolution contrast-enhanced MRA allowed detailed morphologic and dynamic evaluation of cavopulmonary connections in adult patients with congenital heart disease. A wide variation in anatomic dimensions and perfusion patterns was confidently identified in this patient population.

  11. Combined dynamic contrast-enhancement and serial 3D-subtraction analysis in magnetic resonance imaging of osteoid osteomas

    Energy Technology Data Exchange (ETDEWEB)

    Kalle, T. von; Winkler, P. [Klinikum Stuttgart Olgahospital, Department of Paediatric Radiology, Stuttgart (Germany); Langendoerfer, M.; Fernandez, F.F. [Klinikum Stuttgart Olgahospital, Department of Paediatric Orthopaedics, Stuttgart (Germany)

    2009-10-15

    The purpose of this study was to retrospectively correlate the results of dynamic contrast-enhanced magnetic resonance imaging (MRI) with histological and clinical diagnoses in patients with osteoid osteomas. Fifty-four patients with the MR diagnosis of osteoid osteoma were studied. MRI (1.5 Tesla) consisted of thin-section STIR sequences, dynamic 3D T1 gradient echo sequences during application of contrast material, and high-resolution postcontrast T1 spin echo sequences with fat saturation (maximum voxel size 0.6 x 0.6 x 3.0 mm). Evaluation was focused on serial image subtraction during the early phase after contrast injection and on time-intensity curves. The surrounding edema was helpful in finding the nidus in each lesion. In 49 of 54 patients (90.7%), the diagnosis of osteoid osteoma was certain or highly probable (sensitivity 1.0, positive predictive value 0.91). A total of 38 of 54 osteoid osteomas were histologically proven. Five MRI diagnoses were regarded as false positives. A similar proportion has been reported for computed tomography. Tailored high-resolution MR examinations with dynamic contrast enhancement can reliably diagnose osteoid osteomas and exactly localize the nidus without radiation exposure. We propose a stepwise approach with STIR sequences, dynamic contrast-enhanced scanning, and high-resolution postcontrast T1 spin echo sequences with fat saturation. (orig.)

  12. FDG-PET/contrast-enhanced CT as a post-treatment tool in head and neck squamous cell carcinoma: comparison with FDG-PET/non-contrast-enhanced CT and contrast-enhanced CT

    Energy Technology Data Exchange (ETDEWEB)

    Suenaga, Yuko; Kitajima, Kazuhiro; Sugimura, Kazuro [Kobe University Graduate School of Medicine, Department of Radiology, Kobe (Japan); Ishihara, Takeaki; Sasaki, Ryohei [Kobe University Graduate, School of Medicine, Department of Radiology, Division of Radiation Oncology, Kobe (Japan); Otsuki, Naoki; Nibu, Ken-ichi [Kobe University Graduate, School of Medicine, Department of Otolaryngology-Head and Neck Surgery, Kobe (Japan); Minamikawa, Tsutomu [Kobe University Graduate School of Medicine, Department of Oral and Maxillofacial Surgery, Kobe (Japan); Kiyota, Naomi [Kobe University Hospital, Department of Medical Oncology and Hematology, Kobe (Japan)

    2016-04-15

    To evaluate the accuracy of PET/CT using {sup 18}F-fluorodeoxyglucose (FDG) with IV contrast for suspected recurrent head and neck squamous cell carcinoma (HNSCC). One hundred and seventy patients previously treated for HNSCC underwent PET/CT, consisting of non-contrast-enhanced and contrast-enhanced CT, to investigate suspected recurrence. Diagnostic performance of PET/contrast-enhanced CT (PET/ceCT), PET/non-contrast-enhanced CT (PET/ncCT) and contrast-enhanced CT (ceCT) for local or regional recurrence, distant metastasis, overall recurrence and second primary cancer was evaluated. The reference standard included histopathology, treatment change and imaging follow-up. The patient-based areas under the receiver operating characteristic curves (AUC) for ceCT, PET/ncCT and PET/ceCT were 0.82, 0.96 and 0.98 for local recurrence, 0.73, 0.86 and 0.86 for regional recurrence, 0.86, 0.91 and 0.92 for distant metastasis, 0.72, 0.86 and 0.87 for overall recurrence, and 0.86, 0.89 and 0.91 for a second primary cancer. Both PET/ceCT and PET/ncCT statistically showed larger AUC than ceCT for recurrence, and the difference between PET/ceCT and PET/ncCT for local recurrence reached a significant level (p = 0.039). The accuracy of PET/ceCT for diagnosing overall recurrence was high, irrespective of the time interval after the last treatment (83.3-94.1 %). FDG-PET/CT was a more accurate HNSCC restaging tool than ceCT. The added value of ceCT at FDG-PET/CT is minimal. (orig.)

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2011-11-15

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

  14. Selective polarization imager for contrast enhancement in extended scattering media

    Science.gov (United States)

    Miller, Darren Alexis

    Improved imaging and detection of objects through turbid obscurants is a vital problem of current interest to both military and civilian entities. Image quality is severely degraded when obscurant fields such as fog, smoke, dust, etc., lie between an object and the light-collecting optics. Conventional intensity imaging through turbid media suffers from rapid loss of image contrast due to light scattering from particles (e.g. in fog) or random variations of refractive index (e.g. in medical imaging). Intensity imaging does not differentiate between rays scattered off particles in the obscurant field and those reflected off objects within the field. Scattering degrades image quality in all spectral bands (UV, visible, and IR), although the amount of degradation is wavelength dependent. This dissertation features the development of innovative system designs and techniques that utilize scattered radiation's deterministic polarization state evolution to greatly enhance the image contrast of stand-off objects within obscurant fields such as smoke, fog, or dust using active polarized illumination in the visible. The produced sensors acquire and process image data in real time using computationally non-intensive algorithms that differentiate between radiation that scatters or reflects from obscured objects and the radiation from the scattering media, improving image contrast by factors of ten or greater for dense water vapor obscurants.

  15. Suspected aortic dissection and other aortic disorders: multi-detector row CT in 373 cases in the emergency setting.

    Science.gov (United States)

    Hayter, Robert G; Rhea, James T; Small, Andrew; Tafazoli, Faranak S; Novelline, Robert A

    2006-03-01

    To retrospectively review the authors' experience with multi-detector row computed tomography (CT) for detection of aortic dissection in the emergency setting. The investigation was institutional review board approved, did not require informed patient consent, and was HIPAA compliant. In 373 clinical evaluations in the emergency setting, 365 patients suspected of having aortic dissection and/or other aortic disorders underwent multidetector CT. Criteria for acute aortic disorder were confirmed by using surgical and pathologic diagnoses or findings at clinical follow-up and any subsequent imaging as the reference standard. Positive cases were characterized according to type of disorder interpreted. Resulting sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy were calculated by using two-way contingency tables. All cases found to be negative for acute aortic disorders were grouped according to alternative CT findings. Sixty-seven (18.0%) of the 373 cases were interpreted as positive for acute aortic disorder. One hundred twelve acute aortic disorders were identified in these 67 cases: 23 acute aortic dissections, 14 acute aortic intramural hematomas, 20 acute penetrating aortic ulcers, 44 new or enlarging aortic aneurysms, and 11 acute aortic ruptures. Three hundred five (81.8%) cases were interpreted as negative for acute aortic disorder. In 48 negative cases, multidetector CT depicted alternative findings that accounted for the clinical presentation. Of these, three included both acute aortic disorders and alternative findings, and 45 included only alternative findings. One (0.3%) case was indeterminate for acute aortic disorder. Overall, 112 findings were interpreted as positive for acute aortic disorder, an alternative finding, or both at CT. No interpretations were false-positive, one was false-negative, 67 were true-positive, and 304 were true-negative. Sensitivity, specificity, PPV, NPV, and accuracy were

  16. [Computed tomography of the heart

    DEFF Research Database (Denmark)

    Kristensen, T.S.; Kofoed, K.F.; der, Recke P. von;

    2009-01-01

    Noninvasive evaluation of the coronary arteries by multi-detector row computed tomography is a promising new alternative to conventional invasive coronary angiography. This article describes the technical background, methods, limitations and clinical applications and reviews current literature...

  17. The effects of emphysema on airway disease: Correlations between multi-detector CT and pulmonary function tests in smokers

    Energy Technology Data Exchange (ETDEWEB)

    Yahaba, Misuzu, E-mail: mis_misuzu@yahoo.co.jp; Kawata, Naoko, E-mail: chumito_03@yahoo.co.jp; Iesato, Ken, E-mail: iesato_k@yahoo.co.jp; Matsuura, Yukiko, E-mail: matsuyuki_future@yahoo.co.jp; Sugiura, Toshihiko, E-mail: sugiura@js3.so-net.ne.jp; Kasai, Hajime, E-mail: daikasai6075@yahoo.co.jp; Sakurai, Yoriko, E-mail: yoliri@nifty.com; Terada, Jiro, E-mail: jirotera@chiba-u.jp; Sakao, Seiichiro, E-mail: sakao@faculty.chiba-u.jp; Tada, Yuji, E-mail: ytada@faculty.chiba-u.jp; Tanabe, Nobuhiro, E-mail: ntanabe@faculty.chiba-u.jp; Tatsumi, Koichiro, E-mail: tatsumi@faculty.chiba-u.jp

    2014-06-15

    Background: Chronic obstructive pulmonary disease (COPD) is characterized by airflow limitation caused by emphysema and small airway narrowing. Quantitative evaluation of airway dimensions by multi-detector computed tomography (MDCT) has revealed a correlation between airway dimension and airflow limitation. However, the effect of emphysema on this correlation is unclear. Objective: The goal of this study was to determine whether emphysematous changes alter the relationships between airflow limitation and airway dimensions as measured by inspiratory and expiratory MDCT. Methods: Ninety-one subjects underwent inspiratory and expiratory MDCT. Images were evaluated for mean airway luminal area (Ai), wall area percentage (WA%) from the third to the fifth generation of three bronchi (B1, B5, B8) in the right lung, and low attenuation volume percent (LAV%). Correlations between each airway index and airflow limitation were determined for each patient and compared between patients with and without evidence of emphysema. Results: In patients without emphysema, Ai and WA% from both the inspiratory and expiratory scans were significantly correlated with FEV{sub 1.} No correlation was detected in patients with emphysema. In addition, emphysematous COPD patients with GOLD stage 1 or 2 disease had significantly lower changes in B8 Ai than non-emphysematous patients. Conclusions: A significant correlation exists between airway parameters and FEV{sub 1} in patients without emphysema. Emphysema may influence airway dimensions even in patients with mild to moderate COPD.

  18. Aneurysms complicating inflammatory diseases in immunocompromised hosts: value of contrast-enhanced CT

    Energy Technology Data Exchange (ETDEWEB)

    Heussel, C.P. [Dept. of Radiology, Univ. of Mainz (Germany); Kauczor, H.U. [Dept. of Radiology, Univ. of Mainz (Germany); Heussel, G. [Dept. of Hematology, Univ. of Mainz (Germany); Mildenberger, P. [Dept. of Radiology, Univ. of Mainz (Germany); Dueber, C. [Dept. of Radiology, Univ. of Mainz (Germany)

    1997-04-01

    We studied the value of contrast-enhanced CT in the detection of aneurysms in immunocompromised patients suffering from inflammatory diseases eventually complicated by hemorrhage. Contrast-enhanced spiral CT was applied in three patients with immunocompromise due to chemotherapy, alcohol abuse or HIV. They suffered from invasive aspergillosis, chronic pancreatitis with pseudocyst formation, and acute pancreatitis together with HIV-associated lymphadenopathy. Complicating hemorrhage was present in two cases. Contrast-enhanced CT showed aneurysms complicating the underlying inflammatory disease in all three cases. The feeding vessels were identified and the patients with signs of bleeding were subsequently referred for angiography and embolization. Contrast-enhanced spiral CT is suited to detect aneurysms in immunocompromised patients suffering from inflammatory disease. It is recommended in these patients prior to angiography and intervention. (orig.). With 3 figs.

  19. Biliary complications following orthotopic liver transplantation: May contrast-enhanced MR Cholangiography provide additional information?

    Directory of Open Access Journals (Sweden)

    Piero Boraschi

    2016-01-01

    Conclusions: Contrast-enhanced T1-weighted MR Cholangiography may improve the level of diagnostic confidence provided by conventional T2-weighted MR Cholangiography in the evaluation of biliary complications after orthotopic liver transplantation.

  20. Contrast-enhanced ultrasound in testicular trauma: role in directing exploration, debridement and organ salvage.

    Science.gov (United States)

    Hedayati, V; Sellars, M E; Sharma, D M; Sidhu, P S

    2012-03-01

    We describe the use of contrast-enhanced ultrasound as an additional imaging technique during an ultrasound examination of a traumatised testis, allowing for confident testicular preserving surgery to be performed.

  1. Multi-detector CT imaging in the postoperative orthopedic patient with metal hardware.

    Science.gov (United States)

    Vande Berg, Bruno; Malghem, Jacques; Maldague, Baudouin; Lecouvet, Frederic

    2006-12-01

    Multi-detector CT imaging (MDCT) becomes routine imaging modality in the assessment of the postoperative orthopedic patients with metallic instrumentation that degrades image quality at MR imaging. This article reviews the physical basis and CT appearance of such metal-related artifacts. It also addresses the clinical value of MDCT in postoperative orthopedic patients with emphasis on fracture healing, spinal fusion or arthrodesis, and joint replacement. MDCT imaging shows limitations in the assessment of the bone marrow cavity and of the soft tissues for which MR imaging remains the imaging modality of choice despite metal-related anatomic distortions and signal alteration.

  2. Double Chooz: optimizing the sensitivity to {theta}{sub 13} with a multi-detector setup

    Energy Technology Data Exchange (ETDEWEB)

    Novella, P. [CIEMAT, Av. Complutense 22, 28040 Madrid (Spain)

    2012-08-15

    The best upper limit to the neutrino mixing angle {theta}{sub 13} is set by the CHOOZ experiment. The eventual measurement of {theta}{sub 13} in reactor neutrino experiments relies on a reduction of the CHOOZ systematics of about 1 order of magnitude, along with a major increase of the luminosity. Provided that enough statistics are achieved, fighting the systematics becomes the key towards {theta}{sub 13}. The Double Chooz experiment engages this fight with a multi-detector set up.

  3. Control electronics for a multi-laser/multi-detector scanning system

    Science.gov (United States)

    Kennedy, W.

    1980-01-01

    The Mars Rover Laser Scanning system uses a precision laser pointing mechanism, a photodetector array, and the concept of triangulation to perform three dimensional scene analysis. The system is used for real time terrain sensing and vision. The Multi-Laser/Multi-Detector laser scanning system is controlled by a digital device called the ML/MD controller. A next generation laser scanning system, based on the Level 2 controller, is microprocessor based. The new controller capabilities far exceed those of the ML/MD device. The first draft circuit details and general software structure are presented.

  4. Dynamic contrast-enhanced MRI for monitoring response to neoadjuvant chemotherapy in breast cancer

    OpenAIRE

    Loo, C E

    2016-01-01

    The general aim of this thesis is to investigate the role of dynamic contrast-enhanced MRI in monitoring response of breast cancer during neoadjuvant chemotherapy. The role of MRI with respect to achieving personalized breast cancer treatment by improving response monitoring is examined. Our findings demonstrate the potential clinical relevance of contrast-enhanced MRI for monitoring response of breast cancer during and after neoadjuvant chemotherapy. We defined MRI criteria ( reduction < 25%...

  5. Synthesis and functionalization of Gd-based nanoparticles for MRI contrast enhancement

    OpenAIRE

    Skallberg, Andreas

    2011-01-01

    Magnetic metal oxide nanoparticles for contrast enhancement in Magnetic Resonance Imaging (MRI) have proven to be one of the most promising applications in diagnostic science. The nanoparticles can provide better and more accurate diagnosis by their capability to enhance the contrast between different soft tissues. New and better contrast agents need to be developed, to further improve this contrast enhancement. This thesis is focused on biofunctionalization of gadolinium oxide (Gd2O3) nanopa...

  6. Monte Carlo simulation of contrast-enhanced whole brain radiotherapy on a CT scanner.

    Science.gov (United States)

    Schultz, Bernd-Joachim; Wust, Peter; Lüdemann, Lutz; Jost, Gregor; Pietsch, Hubertus

    2011-08-01

    To perform a feasibility study of contrast-enhanced whole brain radiotherapy for treating patients with multiple brain metastasis using a conventional computed tomography (CT) scanner. The treatment dose was optimized to be applied in a single run using a maximum tube power of 5200 kWs at 140 kV. CT scans of a large and a small head were used as reference. Irradiation geometry, shielding, axial beam collimation, radial beam collimation, gantry tilt, and tube current for beam modulation were optimized using a Monte Carlo simulation and a contrast agent concentration of 5 mg/ml iodine in the tumor. The statistical uncertainty of the Monte Carlo simulation was corrected using back convolution. Using a CT tube with a beam collimation of 28.8 mm, a mean tumor dose of 1.76 +/- 0.13 Gy was achieved, while the head bone dose was 2.61 +/- 0.18 Gy with a normal brain dose of 0.98 +/- 0.06 Gy, eye dose of 0.19 +/- 0.05 Gy, and lens dose of 0.15 +/- 0.03 Gy, respectively. Using a CT tube with dose modulation and a beam collimation of 40.0 mm, the mean tumor dose was 2.00 +/- 0.11 Gy with a head bone dose of 1.96 +/- 0.14 Gy, normal brain dose of 1.13 +/- 0.08 Gy, eye dose of 0.21 +/- 0.05 Gy, and lens dose of 0.16 +/- 0.02 Gy, respectively. Thus a standard CT scanner enables an effective tumor dose of 37.0 Gy to be administered in 13 fractions, while exposing healthy brain to an effective dose of 17.2 Gy and head bone to 69.3 Gy. Additional radial collimation implemented in the hardware improves the therapeutic tumor dose by 25.2% in relation to the bone dose. Contrast-enhanced total brain radiotherapy is feasible using a conventional CT tube with optimized dose application.

  7. RENAL TUMOR QUANTIFICATION AND CLASSIFICATION IN TRIPLE-PHASE CONTRAST-ENHANCED ABDOMINAL CT

    Science.gov (United States)

    Gautam, Rabindra; Peterson, James; Yao, Jianhua; Linehan, W. Marston; Summers, Ronald M.

    2009-01-01

    It is estimated that a quarter of a million people in the USA are living with kidney cancer. In clinical practice, the response to treatment is monitored by manual measurements of tumor size, which are time consuming and show high intra- and inter-operator variability. We propose a computer-assisted radiology tool to assess renal tumors in contrast-enhanced CT for the management of tumor diagnoses and treatments. The algorithm employs anisotropic diffusion, a combination of fast-marching and geodesic level-sets, and a novel statistical refinement step to adapt to the shape of the lesions. It also quantifies the 3D size, volume and enhancement of the lesion and allows serial management of tumors. The comparison between manual and semi-automated quantifications shows disparity within the limits of inter-observer variability. The automated tumor classification shows great separation between cysts, von Hippel-Lindau syndrome (VHL) lesions and hereditary papillary renal carcinomas (HPRC) (p < 0.004). PMID:20383290

  8. Volumetric texture analysis of breast lesions on contrast-enhanced magnetic resonance images.

    Science.gov (United States)

    Chen, Weijie; Giger, Maryellen L; Li, Hui; Bick, Ulrich; Newstead, Gillian M

    2007-09-01

    Automated image analysis aims to extract relevant information from contrast-enhanced magnetic resonance images (CE-MRI) of the breast and improve the accuracy and consistency of image interpretation. In this work, we extend the traditional 2D gray-level co-occurrence matrix (GLCM) method to investigate a volumetric texture analysis approach and apply it for the characterization of breast MR lesions. Our database of breast MR images was obtained using a T1-weighted 3D spoiled gradient echo sequence and consists of 121 biopsy-proven lesions (77 malignant and 44 benign). A fuzzy c-means clustering (FCM) based method is employed to automatically segment 3D breast lesions on CE-MR images. For each 3D lesion, a nondirectional GLCM is then computed on the first postcontrast frame by summing 13 directional GLCMs. Texture features are extracted from the nondirectional GLCMs and the performance of each texture feature in the task of distinguishing between malignant and benign breast lesions is assessed by receiver operating characteristics (ROC) analysis. Our results show that the classification performance of volumetric texture features is significantly better than that based on 2D analysis. Our investigations of the effects of various of parameters on the diagnostic accuracy provided means for the optimal use of the approach.

  9. Ultrasonography and contrast-enhanced CT findings of tularemia in the neck

    Science.gov (United States)

    Doğan, Serap; Ekinci, Afra; Demiraslan, Hayati; Kılıç, Ayşegül Ulu; Mavili, Ertuğrul; Öztürk, Mustafa; İmamoğlu, Hakan; Doğanay, Mehmet

    2016-01-01

    PURPOSE We aimed to evaluate the ultrasonography (US) and contrast-enhanced computed tomography (CECT) findings of tularemia in the neck. METHODS US and CECT findings of 58 patients with serologically proven tularemia were retrospectively evaluated. Forty-eight patients underwent US and 42 patients underwent CECT. Lymph node characteristics and parotid preauricular region involvement were analyzed using US and CECT. In addition, involvement of larynx, oropharynx, and retropharynx; presence of periorbital edema; and neck abscess formation were evaluated using CECT. Fine needle aspiration cytology (FNAC) results of enlarged lymph nodes were analyzed in 29 patients. RESULTS Hypoechoic pattern, round shape, absence of hilum, and cystic necrosis were seen in most of the lymph nodes especially at level 2 and 3 on US and CECT. Matting was more commonly observed than irregular nodal border on US and CECT. Parotid preauricular region involvement was seen in 20.8% of patients on US. Oropharyngeal, retropharyngeal, laryngeal and parotid preauricular region involvement and periorbital edema were seen in 52.4%, 19.1%, 4.8%, 31%, and 9.5% of tularemia patients, respectively. Neck abscess was found in 59.5% of patients on CECT. Suppurative inflammation was the most common finding of FNAC. CONCLUSION Tularemia should be considered in the presence of level 2 and 3 lymph nodes with cystic necrosis, matting, absence of calcification, oropharyngeal and retropharyngeal region involvement, and neck abscess, particularly in endemic areas. PMID:27498683

  10. Dynamic contrast-enhanced photoacoustic imaging using photothermal stimuli-responsive composite nanomodulators

    Science.gov (United States)

    Chen, Yun-Sheng; Yoon, Soon Joon; Frey, Wolfgang; Dockery, Mary; Emelianov, Stanislav

    2017-06-01

    Molecular photoacoustic imaging has shown great potential in medical applications; its sensitivity is normally in pico-to-micro-molar range, dependent on exogenous imaging agents. However, tissue can produce strong background signals, which mask the signals from the imaging agents, resulting in orders of magnitude sensitivity reduction. As such, an elaborate spectral scan is often required to spectrally un-mix the unwanted background signals. Here we show a new single-wavelength photoacoustic dynamic contrast-enhanced imaging technique by employing a stimuli-responsive contrast agent. Our technique can eliminate intrinsic background noises without significant hardware or computational resources. We show that this new contrast agent can generate up to 30 times stronger photoacoustic signals than the concentration-matched inorganic nanoparticle counterparts. By dynamically modulating signals from the contrast agents with an external near-infrared optical stimulus, we can further suppress the background signals leading to an additional increase of more than five-fold in imaging contrast in vivo.

  11. Assessing Tumor Response to Treatment in Patients with Lung Cancer Using Dynamic Contrast-Enhanced CT

    Directory of Open Access Journals (Sweden)

    Louise S. Strauch

    2016-07-01

    Full Text Available The aim of this study was to provide an overview of the literature available on dynamic contrast-enhanced computed tomography (DCE-CT as a tool to evaluate treatment response in patients with lung cancer. This systematic review was compiled according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA guidelines. Only original research articles concerning treatment response in patients with lung cancer assessed with DCE-CT were included. To assess the validity of each study we implemented Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2. The initial search yielded 651 publications, and 16 articles were included in this study. The articles were divided into groups of treatment. In studies where patients were treated with systemic chemotherapy with or without anti-angiogenic drugs, four out of the seven studies found a significant decrease in permeability after treatment. Four out of five studies that measured blood flow post anti-angiogenic treatments found that blood flow was significantly decreased. DCE-CT may be a useful tool in assessing treatment response in patients with lung cancer. It seems that particularly permeability and blood flow are important perfusion values for predicting treatment outcome. However, the heterogeneity in scan protocols, scan parameters, and time between scans makes it difficult to compare the included studies.

  12. Normal or abnormal? Demystifying uterine and cervical contrast enhancement at multidetector CT.

    Science.gov (United States)

    Yitta, Silaja; Hecht, Elizabeth M; Mausner, Elizabeth V; Bennett, Genevieve L

    2011-01-01

    Computed tomography (CT) is not generally advocated as the first-line imaging examination for disorders of the female pelvis. However, multidetector CT is often the modality of choice for evaluating nongynecologic pelvic abnormalities, particularly in emergent settings, in which all the pelvic organs are invariably assessed. Incidental findings of uterine and cervical contrast enhancement in such settings may easily be mistaken for abnormalities, given the broad spectrum of anatomic variants and enhancement patterns that may be seen in the normal uterus and cervix. The authors' review of CT and magnetic resonance (MR) imaging enhancement patterns, augmented by case examples from their clinical radiology practice, provides a solid foundation for understanding the spectrum of normal uterine and cervical appearances and avoiding potential pitfalls in the diagnosis of benign cervical lesions, adenomyosis, infection, malignancy, and postpartum effects. This information should help radiologists more confidently differentiate between normal and abnormal CT findings and, when CT findings are not definitive, offer appropriate recommendations for follow-up ultrasonography or MR imaging.

  13. Use of Second generation contrast-enhanced ultrasound in the assessment of focal liver lesions

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Ultrasound (US) is often the first imaging modality employed in patients with suspected focal liver lesions.The role of US in the characterisation of focal liver lesions has been transformed with the introduction of specific contrast media and the development of specialized imaging techniques. Ultrasound now can fully characterise the enhancement pattern of hepatic lesions, similar to that achieved with contrast enhanced multiphasic computed tomography (CT) and magnetic resonance imaging (MRI). US contrast agents are safe,well-tolerated and have very few contraindications.Furthermore, real-time evaluation of the vascularity of focal liver lesions has become possible with the use of the newer microbubble contrast agents. This article reviews the enhancement pattern of the most frequent liver lesions seen, using the second generation US contrast media. The common pitfalls for each type of lesion are discussed. The recent developments in US contrast media and specific imaging techniques have been a major advance and this technique, in view of the intrinsic advantages of US, will undoubtedly gain popularity in the years to come.

  14. Contrast enhancement of the cochlear aqueduct in MR imaging: its frequency and clinical significance

    Energy Technology Data Exchange (ETDEWEB)

    Nakamura, T.; Naganawa, S.; Fukatsu, H.; Sakurai, Y.; Ishigaki, T. [Department of Radiology, Nagoya University School of Medicine, 65 Tsurumai-cho, 466-8550, Shouwa-ku, Nagoya (Japan); Aoki, I.; Ninomiya, A. [Medical Systems Company, Toshiba Corporation, Nasu Operations, Otawara-shi, Tochigi (Japan); Nakashima, T. [Department of Otorhinolaryngology, Nagoya University School of Medicine, Shouwa-ku, Nagoya (Japan)

    2003-09-01

    There have been no previous reports on contrast enhancement of the cochlear aqueduct in magnetic resonance imaging. The purpose of the present study was to evaluate the frequency and significance of this finding. Thirty-one patients (15 men and 16 women; age range 18-81 years) with otologic symptoms (sudden sensorineural hearing loss, vertigo, or tinnitus) were examined using contrast-enhanced imaging on a 1.5-T MR scanner. The normal ear served as the control. Two radiologists evaluated contrast enhancement in the area of the cochlear aqueduct. Forty-eight of 62 ears (77.4%) showed contrast enhancement of the cochlear aqueduct, but no significant differences in the frequency of contrast enhancement were observed between patients with and patients without vertigo, tinnitus, sensorineural hearing loss, cerebellopontine angle tumors, or a high-riding jugular bulb. In addition, no gender- or age-related differences were noted. Contrast enhancement of the cochlear aqueduct was frequently observed, but the frequency of enhancement in symptomatic ears was not significantly higher than in control ears. The results of this study may prove helpful in avoiding unnecessary examinations and potential diagnostic confusion. (orig.)

  15. Contrast enhanced MR imaging of female pelvic cancers: Established methods and emerging applications

    Energy Technology Data Exchange (ETDEWEB)

    Punwani, Shonit, E-mail: shonit.punwani@gmail.com [Department of Academic Radiology, 2nd Floor Podium, University College London Hospital, 235 Euston Road, London NW1 2BU (United Kingdom)

    2011-04-15

    Contrast enhanced magnetic resonance imaging of female pelvic cancers has been established for over 20 years. Conventional contrast enhanced imaging involves acquiring a set of pre-contrast T1 weighted images, followed by intravenous injection of an gadolinium based contrast agent and subsequent acquisition of a second set of contrast enhanced images. Developments in MR hardware and pulse sequences over the last 10 years have made dynamic contrast enhanced (DCE) protocols possible. DCE-MRI entails imaging of the same volume repeatedly prior to, during and following contrast injection. There have also been developments in image analysis methods and tools to reflect the increased data acquired. Qualitative analysis of contrast enhanced imaging (whether a single set or temporal series) by radiologists remains the mainstay for clinical reporting. Semi-quantitative assessment of signal intensity versus time curves and full pharmacokinetic modelling methods have emerged for evaluation of DCE-MRI data. DCE-MRI has found an established role in the detection, localisation and staging of female pelvic malignancies. Emerging applications of DCE-MRI include assessment of tumour grade, histology prior to and following treatment and prediction of individual and final treatment outcome. This article reviews the biophysical basis of contrast enhancement, the technical aspects of performance and analysis of DCE-MRI studies, and the established and emerging clinical utility of DCE-MRI in female pelvic malignancies.

  16. Gray-scale contrast-enhanced utrasonography in detecting sentinel lymph nodes: An animal study

    Energy Technology Data Exchange (ETDEWEB)

    Wang Yuexiang, E-mail: wangyuexiang1999@sina.co [Department of Ultrasound, Chinese People' s Liberation Army General Hospital, 28 Fuxing Road, Beijing 100853 (China); Cheng Zhigang, E-mail: qlczg@sina.co [Department of Ultrasound, Chinese People' s Liberation Army General Hospital, 28 Fuxing Road, Beijing 100853 (China); Li Junlai, E-mail: junlai555@sina.co [Department of Ultrasound, Chinese People' s Liberation Army General Hospital, 28 Fuxing Road, Beijing 100853 (China); Tang Jie, E-mail: txiner@vip.sina.co [Department of Ultrasound, Chinese People' s Liberation Army General Hospital, 28 Fuxing Road, Beijing 100853 (China)

    2010-06-15

    Objective: To investigate the usefulness of gray-scale contrast-enhanced ultrasonography for detecting sentinel lymph nodes. Methods: Contrast-enhanced ultrasonography was performed in five normal dogs (four female and one male) after subcutaneous administration of a sonographic contrast agent (Sonovue, Bracco, Milan, Italy). Four distinct regions in each animal were examined. After contrast-enhanced ultrasonography, 0.8 ml of blue dye was injected into the same location as Sonovue and the sentinel lymph nodes were detected by surgical dissection. The findings of contrast-enhanced ultrasonography were compared with those of the blue dye. Results: Twenty-one sentinel lymph nodes were detected by contrast-enhanced ultrasonography while 23 were identified by blue dye with surgical dissection. Compared with the blue dye, the detection rate of enhanced ultrasonography for the sentinel lymph nodes is 91.3% (21/23). Two patterns of enhancement in the sentinel lymph nodes were observed: complete enhancement (5 sentinel lymph nodes) and partial enhancement (16 sentinel lymph nodes). The lymphatic channels were demonstrated as hyperechoic linear structures leading from the injection site and could be readily followed to their sentinel lymph nodes. Histopathologic examination showed proliferation of lymphatic follicles or lymphatic sinus in partial enhanced sentinel lymph nodes while normal lymphatic tissue was demonstrated in completely enhanced sentinel lymph nodes. Conclusions: Sonovue combined with gray-scale contrast-enhanced ultrasonography may provide a feasible method for detecting sentinel lymph nodes.

  17. Contrast-enhanced harmonic ultrasonography of medial iliac lymph nodes in healthy dogs.

    Science.gov (United States)

    Gaschen, Lorrie; Angelette, Nik; Stout, Rhett

    2010-01-01

    Herein, we describe the normal contrast-enhanced harmonic, color, and power Doppler ultrasonographic characteristics of the medial iliac lymph nodes in healthy dogs. Contrast-enhanced harmonic ultrasonography of the medial iliac lymph nodes was performed on 14 healthy dogs after intravenous administration of the lipoprotein-bound inert gas-filled microbubble contrast media Definity. Time-pixel intensity curves were generated for 1-min postinjection. Quantification of these curves was performed using Philips QLab software. Non-contrast-enhanced power and color Doppler examinations were performed in each node to assess vascular patterns subjectively. Normal lymph nodes exhibited a mean contrast wash-in phase beginning at 6.3 s from the time of injection with mean peak pixel intensity at 12.1s. Angioarchitecture was best visualized with contrast-enhanced harmonic ultrasound compared with power and color Doppler. Normal lymph nodes in dogs have a central artery with a centrifugal and uniform branching pattern. Contrast-enhanced harmonic ultrasonography is a noninvasive examination that demonstrates improved visibility of the intranodal architecture of healthy medial iliac lymph nodes in dogs compared with conventional, non-contrast-enhanced Doppler methods that may have future clinical applications.

  18. Dynamic contrast-enhanced magnetic resonance imaging of the wrist in children with juvenile idiopathic arthritis

    Energy Technology Data Exchange (ETDEWEB)

    Nusman, Charlotte M. [Emma Children' s Hospital, Department of Pediatric Hematology, Immunology, Rheumatology and Infectious Disease, Academic Medical Center, Amsterdam (Netherlands); Academic Medical Center, Department of Radiology, Amsterdam (Netherlands); Lavini, Cristina; Hemke, Robert; Caan, Matthan W.A.; Maas, Mario [Academic Medical Center, Department of Radiology, Amsterdam (Netherlands); Schonenberg-Meinema, Dieneke; Berg, J.M. van den; Kuijpers, Taco W. [Emma Children' s Hospital, Department of Pediatric Hematology, Immunology, Rheumatology and Infectious Disease, Academic Medical Center, Amsterdam (Netherlands); Dolman, Koert M. [Sint Lucas Andreas Hospital, Department of Pediatrics, Amsterdam (Netherlands); Reade Institute location Jan van Breemen, Department of Pediatric Rheumatology, Amsterdam (Netherlands); Rossum, Marion A.J. van [Reade Institute location Jan van Breemen, Department of Pediatric Rheumatology, Amsterdam (Netherlands); Emma Children' s Hospital, Department of Pediatrics, Academic Medical Center, Amsterdam (Netherlands)

    2017-02-15

    Dynamic contrast-enhanced MRI provides information on the heterogeneity of the synovium, the primary target of disease in children with juvenile idiopathic arthritis (JIA). To evaluate the feasibility of dynamic contrast-enhanced MRI in the wrist of children with JIA using conventional descriptive measures and time-intensity-curve shape analysis. To explore the association between enhancement characteristics and clinical disease status. Thirty-two children with JIA and wrist involvement underwent dynamic contrast-enhanced MRI with movement-registration and were classified using validated criteria as clinically active (n = 27) or inactive (n = 5). Outcome measures included descriptive parameters and the classification into time-intensity-curve shapes, which represent the patterns of signal intensity change over time. Differences in dynamic contrast-enhanced MRI outcome measures between clinically active and clinically inactive disease were analyzed and correlation with the Juvenile Arthritis Disease Activity Score was determined. Comprehensive evaluation of disease status was technically feasible and the quality of the dynamic dataset was improved by movement registration. The conventional descriptive measure maximum enhancement differed significantly between clinically active and inactive disease (P = 0.019), whereas time-intensity-curve shape analysis showed no differences. Juvenile Arthritis Disease Activity Score correlated moderately with enhancing volume (P = 0.484). Dynamic contrast-enhanced MRI is a promising biomarker for evaluating disease status in children with JIA and wrist involvement. Conventional descriptive dynamic contrast-enhanced MRI measures are better associated with clinically active disease than time-intensity-curve shape analysis. (orig.)

  19. Comparison between PUN and Tofts models in the quantification of dynamic contrast-enhanced MR imaging

    Science.gov (United States)

    Mazzetti, S.; Gliozzi, A. S.; Bracco, C.; Russo, F.; Regge, D.; Stasi, M.

    2012-12-01

    Dynamic contrast-enhanced study in magnetic resonance imaging (DCE-MRI) is an important tool in oncology to visualize tissues vascularization and to define tumour aggressiveness on the basis of an altered perfusion and permeability. Pharmacokinetic models are generally used to extract hemodynamic parameters, providing a quantitative description of the contrast uptake and wash-out. Empirical functions can also be used to fit experimental data without the need of any assumption about tumour physiology, as in pharmacokinetic models, increasing their diagnostic utility, in particular when automatic diagnosis systems are implemented on the basis of an MRI multi-parametric approach. Phenomenological universalities (PUN) represent a novel tool for experimental research and offer a simple and systematic method to represent a set of data independent of the application field. DCE-MRI acquisitions can thus be advantageously evaluated by the extended PUN class, providing a convenient diagnostic tool to analyse functional studies, adding a new set of features for the classification of malignant and benign lesions in computer aided detection systems. In this work the Tofts pharmacokinetic model and the class EU1 generated by the PUN description were compared in the study of DCE-MRI of the prostate, evaluating complexity of model implementation, goodness of fitting results, classification performances and computational cost. The mean R2 obtained with the EU1 and Tofts model were equal to 0.96 and 0.90, respectively, and the classification performances achieved by the EU1 model and the Tofts implementation discriminated malignant from benign tissues with an area under the receiver operating characteristic curve equal to 0.92 and 0.91, respectively. Furthermore, the EU1 model has a simpler functional form which reduces implementation complexity and computational time, requiring 6 min to complete a patient elaboration process, instead of 8 min needed for the Tofts model analysis.

  20. Early and Delayed Myocardial Enhancement in Myocardial Infarction Using Two-Phase Contrast-Enhanced Multidetector-Row CT

    Science.gov (United States)

    Kim, Young-Whan; Han, Seong-Wook; Seo, Joon-Beom

    2007-01-01

    Objective The purpose of this study was to describe the myocardial enhancement patterns in patients with myocardial infarction using two-phase contrast-enhanced multidetector-row computed tomography (MDCT). Materials and Methods Twenty-three patients with clinically proven myocardial infarction (17 acute myocardial infarction [AMI] and 6 chronic myocardial infarction [CMI]) were examined with two-phase contrast-enhanced ECG-gated MDCT. The presence, location, and patterns of myocardial enhancement on two-phase MDCT images were compared with infarcted myocardial territories determined by using electrocardiogram, echocardiography, thallium-201 single photon emission computed tomography, catheter and MDCT coronary angiography. Results After clinical assessment, the presence of myocardial infarctions were found in 27 territories (19 AMI and 8 CMI) of 23 patients. Early perfusion defects were observed in 30 territories of all 23 patients. Three territories not corresponding to a myocardial infarction were detected in three patients with AMI and were associated with artifacts. Fourteen of perfusion defects were in the left anterior descending artery territory, four in the left circumflex artery territory, and nine in the right coronary artery territory. Delayed enhancement was observed in 25 territories (17 AMI and 8 CMI) of 21 patients. Delayed enhancement patterns were variable. Transmural early perfusion defects (n =12) were closely associated with transmural late enhancement (n = 5) and subendocardial residual defect with subepicardial late enhancement (n = 5). Conclusion Myocardial infarction showed early perfusion defects and variable delayed enhancement patterns on two-phase contrast-enhanced MDCT. Delayed enhancement technique of MDCT could provide additional information of the location and extent of infarcted myocardium, and could be useful to plan appropriate therapeutic strategies in patients with AMI. PMID:17420626

  1. Early and Delayed Myocardial Enhancement in Myocardial Infarction Using Two-Phase Contrast-Enhanced Multidetector-Row CT

    Energy Technology Data Exchange (ETDEWEB)

    Ko, Sung-Min; Kim, Young-Whan; Han, Seong-Wook [University of Keimyung College of Medicine, Dongsan Medical Center, Daegu (Korea, Republic of); Seo, Joon-Beom [University of Ulsan College of Medicine, Asan Medical Center, Seoul (Korea, Republic of)

    2007-04-15

    The purpose of this study was to describe the myocardial enhancement patterns in patients with myocardial infarction using two-phase contrast enhanced multidetector-row computed tomography (MDCT). Twenty-three patients with clinically proven myocardial infarction (17 acute myocardial infarction [AMI] and 6 chronic myocardial infarction [CMI]) were examined with two-phase contrast-enhanced ECG-gated MDCT. The presence, location, and patterns of myocardial enhancement on two phase MDCT images were compared with infarcted myocardial territories determined by using electrocardiogram, echocardiography, thallium-201 single photon emission computed tomography, catheter and MDCT coronary angiography. After clinical assessment, the presence of myocardial infarctions were found in 27 territories (19 AMI and 8 CMI) of 23 patients. Early perfusion defects were observed in 30 territories of all 23 patients. Three territories not corresponding to a myocardial infarction were detected in three patients with AMI and were associated with artifacts. Fourteen of perfusion defects were in the left anterior descending artery territory, four in the left circumflex artery territory, and nine in the right coronary artery territory. Delayed enhancement was observed in 25 territories (17 AMI and 8 CMI) of 21 patients. Delayed enhancement patterns were variable. Transmural early perfusion defects (n =12) were closely associated with transmural late enhancement (n = 5) and subendocardial residual defect with subepicardial late enhancement (n = 5). Myocardial infarction showed early perfusion defects and variable delayed enhancement patterns on two-phase contrast-enhanced MDCT. Delayed enhancement technique of MDCT could provide additional information of the location and extent of infarcted myocardium, and could be useful to plan appropriate therapeutic strategies in patients with AMI.

  2. Novel wearable and wireless ring-type pulse oximeter with multi-detectors.

    Science.gov (United States)

    Huang, Cheng-Yang; Chan, Ming-Che; Chen, Chien-Yue; Lin, Bor-Shyh

    2014-01-01

    The pulse oximeter is a popular instrument to monitor the arterial oxygen saturation (SPO2). Although a fingertip-type pulse oximeter is the mainstream one on the market at present, it is still inconvenient for long-term monitoring, in particular, with respect to motion. Therefore, the development of a wearable pulse oximeter, such as a finger base-type pulse oximeter, can effectively solve the above issue. However, the tissue structure of the finger base is complex, and there is lack of detailed information on the effect of the light source and detector placement on measuring SPO2. In this study, the practicability of a ring-type pulse oximeter with a multi-detector was investigated by optical human tissue simulation. The optimal design of a ring-type pulse oximeter that can provide the best efficiency of measuring SPO2 was discussed. The efficiency of ring-type pulse oximeters with a single detector and a multi-detector was also discussed. Finally, a wearable and wireless ring-type pulse oximeter was also implemented to validate the simulation results and was compared with the commercial fingertip-type pulse oximeter.

  3. Novel Wearable and Wireless Ring-Type Pulse Oximeter with Multi-Detectors

    Directory of Open Access Journals (Sweden)

    Cheng-Yang Huang

    2014-09-01

    Full Text Available The pulse oximeter is a popular instrument to monitor the arterial oxygen saturation (SPO2. Although a fingertip-type pulse oximeter is the mainstream one on the market at present, it is still inconvenient for long-term monitoring, in particular, with respect to motion. Therefore, the development of a wearable pulse oximeter, such as a finger base-type pulse oximeter, can effectively solve the above issue. However, the tissue structure of the finger base is complex, and there is lack of detailed information on the effect of the light source and detector placement on measuring SPO2. In this study, the practicability of a ring-type pulse oximeter with a multi-detector was investigated by optical human tissue simulation. The optimal design of a ring-type pulse oximeter that can provide the best efficiency of measuring SPO2 was discussed. The efficiency of ring-type pulse oximeters with a single detector and a multi-detector was also discussed. Finally, a wearable and wireless ring-type pulse oximeter was also implemented to validate the simulation results and was compared with the commercial fingertip-type pulse oximeter.

  4. Dynamic contrast-enhanced MR imaging in osteoid osteoma: relationships with clinical and CT characteristics

    Energy Technology Data Exchange (ETDEWEB)

    Pottecher, P. [Hopital Lariboisiere, AP-HP, Department of Osteoarticular Radiology, Paris (France); Hopital du Bocage, Department of Vascular, Oncologic and Interventional Radiology, Dijon (France); Sibileau, E.; Hamze, B.; Parlier, C.; Laredo, J.D.; Bousson, V. [Hopital Lariboisiere, AP-HP, Department of Osteoarticular Radiology, Paris (France); Aho, S. [Hopital du Bocage, Hospital Hygiene and Epidemiology unit, Dijon (France)

    2017-07-15

    To correlate dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) features to clinical and computed tomography (CT) morphological features of osteoid osteoma (OO). Our institutional review board approved this retrospective study, waiving the need for informed consent. We included the 102 patients treated with interstitial laser ablation for histologically documented OO at our institution in 2008-2013. DCE-MRI variables were the time-enhancement pattern and rising slope (Slope{sub rise}) and CT variables were the bone and segment involved (OO{sub bone} and OO{sub segment,} respectively), OO location relative to the native cortex (OO{sub cortex}), nidus surface area, vessel sign, and largest neighboring-vessel diameter (Dmax{sub vessel}). Descriptive statistics and correlations linking DCE-MRI findings to clinical and CT characteristics were computed. DCE-MRI showed early arterial peak enhancement in 95 (93%) cases, with a mean Slope{sub rise} of 9.30 ± 8.10. CT visualized a vessel sign in 84 (82%) cases with a mean Dmax{sub vessel} of 1.10 ± 0.60 mm. By univariate analysis, Slope{sub rise} correlated significantly with pain duration and Dmax{sub vessel} (r = 0.30, P = 0.003; and r = 0.22, P = 0.03; respectively). Analysis of variance showed that Slope{sub rise} correlated significantly with OO{sub bone} (P < 0.001), with a steeper slope for OOs located in short or flat bones. This study suggests more abundant vascularization of OOs with long-lasting pain and location on short or flat bones. (orig.)

  5. A comparative study on preprocessing techniques in diabetic retinopathy retinal images: illumination correction and contrast enhancement.

    Science.gov (United States)

    Rasta, Seyed Hossein; Partovi, Mahsa Eisazadeh; Seyedarabi, Hadi; Javadzadeh, Alireza

    2015-01-01

    To investigate the effect of preprocessing techniques including contrast enhancement and illumination correction on retinal image quality, a comparative study was carried out. We studied and implemented a few illumination correction and contrast enhancement techniques on color retinal images to find out the best technique for optimum image enhancement. To compare and choose the best illumination correction technique we analyzed the corrected red and green components of color retinal images statistically and visually. The two contrast enhancement techniques were analyzed using a vessel segmentation algorithm by calculating the sensitivity and specificity. The statistical evaluation of the illumination correction techniques were carried out by calculating the coefficients of variation. The dividing method using the median filter to estimate background illumination showed the lowest Coefficients of variations in the red component. The quotient and homomorphic filtering methods after the dividing method presented good results based on their low Coefficients of variations. The contrast limited adaptive histogram equalization increased the sensitivity of the vessel segmentation algorithm up to 5% in the same amount of accuracy. The contrast limited adaptive histogram equalization technique has a higher sensitivity than the polynomial transformation operator as a contrast enhancement technique for vessel segmentation. Three techniques including the dividing method using the median filter to estimate background, quotient based and homomorphic filtering were found as the effective illumination correction techniques based on a statistical evaluation. Applying the local contrast enhancement technique, such as CLAHE, for fundus images presented good potentials in enhancing the vasculature segmentation.

  6. Contrast-enhanced magnetic resonance angiography of persistent fifth aortic arch in children

    Energy Technology Data Exchange (ETDEWEB)

    Zhong, Yumin; Zhu, Ming; Sun, Aimin; Li, Yuhua [Shanghai Jiao Tong University School of Medicine, Department of Radiology, Shanghai Children' s Medical Center, Shanghai (China); Jaffe, Richard B. [Primary Children' s Medical Center, Department of Medical Imaging, Salt Lake City, UT (United States); Gao, Wei [Shanghai Jiao Tong University School of Medicine, Department of Cardiology, Shanghai Children' s Medical Center, Shanghai (China)

    2007-03-15

    Cine angiography and echocardiography have been utilized to diagnose congenital aortic arch anomalies. However, the visualization of great vessels by echocardiography is limited, while cine angiography requires cardiac catheterization with ionizing radiation. Contrast-enhanced magnetic resonance angiography (MRA) is a noninvasive modality suitable for visualization of congenital aortic arch anomalies. To evaluate the utility of contrast-enhanced MRA in the diagnosis of persistent fifth aortic arch, a rare congenital aortic arch anomaly, and to compare the diagnostic accuracy of MRA with that of echocardiography and cine angiography. In four pediatric patients, contrast-enhanced MRA studies were performed for diagnosing persistent fifth aortic arch. The findings of MRA were compared with echocardiographic findings and confirmed by cine angiography and operation. Transthoracic surface echocardiography noted an aberrant vessel arising from the ascending aorta in two of four patients; the etiology of this vessel was uncertain. In the other two patients a diagnosis of coarctation was made. Of the four patients, only one was diagnosed with interruption of the aortic arch. Contrast-enhanced MRA clarified uncertain echocardiographic findings, enabling the correct diagnosis of persistent fifth aortic arch with fourth aortic arch interruption in all four patients. Contrast-enhanced MRA is a safe, accurate, and fast imaging technique for the evaluation of persistent fifth aortic arch and may obviate the need for conventional cine angiography. Cardiac catheterization may be reserved for some types of complicated congenital heart disease and for obtaining hemodynamic information. (orig.)

  7. The role of contrast-enhanced ultrasound in risk assessment of carotid atheroma

    Directory of Open Access Journals (Sweden)

    Silviu Stanciu

    2016-07-01

    Full Text Available Background and objective: Contrast-enhanced ultrasound, used to assess atherosclerotic carotid plaques, improves visualization of vessel wall irregularities and depicts intraplaque neovascularization. This article illustrates the use of contrast-enhanced ultrasound in the risk assessment of carotid atherosclerotic lesions, especially in challenging plaques evaluation. Materials and methods: For 23 patients with difficult duplex ultrasound examination due to carotid tortuosity or calcifications we assessed plaque morphology (contour, echogenicity and stenosis degree using contrast substance (Sonovue, Braco with dedicated vascular low mechanical index CPC software. Conclusion: Contrast-enhanced ultrasound is a new, noninvasive, and safe procedure for imaging carotid atherosclerotic lesions. It is a valuable tool for evaluating the vulnerable plaque at risk for rupture and for the diagnostic of the development and severity of systemic atherosclerotic disease

  8. Contrast-enhanced power Doppler ultrasonography of the metacarpophalangeal joints in rheumatoid arthritis

    DEFF Research Database (Denmark)

    Szkudlarek, Marcin; Court-Payen, Michel; Strandberg, Charlotte;

    2003-01-01

    The aim of this study was to examine, with dynamic contrast-enhanced MRI as the reference, if contrast-enhanced power Doppler ultrasonography (CE PDUS) of rheumatoid arthritis (RA) metacarpophalangeal (MCP) joints provides additional information for evaluation of synovial inflammation compared...... with PDUS. One MCP joint in each of 15 RA patients and 3 healthy control persons were examined with PDUS before and after intravenous bolus Levovist contrast injection. Corresponding rates of early synovial enhancement (RESE), previously shown to be closely related to histopathological synovitis, were...... calculated from dynamic contrast-enhanced MR images obtained the same day. Prior to ultrasonography, the joint was evaluated clinically. Levovist increased the flow signal in 7 of 9 joints with pre-contrast flow-signal and in 0 of 9 without pre-contrast signal. No healthy controls showed CE PDUS signal...

  9. Diagnostic accuracy of contrast-enhanced ultrasound for the differential diagnosis of hepatocellular carcinoma: ESCULAP versus CEUS-LI-RADS.

    Science.gov (United States)

    Schellhaas, Barbara; Görtz, Ruediger S; Pfeifer, Lukas; Kielisch, Christian; Neurath, Markus F; Strobel, Deike

    2017-09-01

    A comparison is made of two contrast-enhanced ultrasound (CEUS) algorithms for the diagnosis of hepatocellular carcinoma (HCC) in high-risk patients: Erlanger Synopsis of Contrast-enhanced Ultrasound for Liver lesion Assessment in Patients at Risk (ESCULAP) and American College of Radiology Contrast-Enhanced Ultrasound-Liver Imaging Reporting and Data System (ACR-CEUS-LI-RADSv.2016). Focal liver lesions in 100 high-risk patients were assessed using both CEUS algorithms (ESCULAP and CEUS-LI-RADSv.2016) for a direct comparison. Lesions were categorized according to size and contrast enhancement in the arterial, portal venous and late phases.For the definite diagnosis of HCC, categories ESCULAP-4, ESCULAP-Tr and ESCULAP-V and CEUS-LI-RADS-LR-5, LR-Tr and LR-5-V were compared. In addition, CEUS-LI-RADS-category LR-M (definitely/probably malignant, but not specific for HCC) and ESCULAP-category C [intrahepatic cholangiocellular carcinoma (ICC)] were compared.Histology, CE-computed tomography and CE-MRI served as reference standards. The reference standard among 100 lesions included 87 HCCs, six ICCs and seven non-HCC-non-ICC-lesions. For the diagnosis of HCC, the diagnostic accuracy of CEUS was significantly higher with ESCULAP versus CEUS-LI-RADS (94.3%/72.4%; p<0.01). Sensitivity, specificity and positive predictive value (PPV) and negative predictive value for ESCULAP/CEUS-LI-RADS were 94.3%/72.4%; 61.5%/69.2%; 94.3%/94%; and 61.5%/27.3%, respectively.The diagnostic accuracy for ICC (LR-M/ESCULAP-C) was identical with both algorithms (50%), with higher PPV for ESCULAP-C versus LR-M (75 vs. 50%). CEUS-based algorithms contribute toward standardized assessment and reporting of HCC-suspect lesions in high-risk patients. ESCULAP shows significantly higher diagnostic accuracy, sensitivity and negative predictive value with no loss of specificity compared with CEUS-LI-RADS. Both algorithms have an excellent PPV. Arterial hyperenhancement is the key feature for the

  10. VALIDITY OF CONTRAST ENHANCED CT IN THE ASSESSMENT OF ACUTE PANCREATITIS AND ITS RELATED COMPLICATIONS

    Directory of Open Access Journals (Sweden)

    Mannivanan

    2016-03-01

    Full Text Available BACKGROUND In the earlier days, ultrasonogram was considered as one of the most important investigation for pancreatitis, later the clinicians started using cholangiography in acute pancreatitis, but today CT is considered as a gold standard test in the diagnosis of acute pancreatitis. Though the sensitivity of CT in diagnosing acute pancreatitis was not studied much particularly in a mild case, but a good-quality contrast enhanced CT demonstrates distinct pancreatic and peri-pancreatic abnormalities. AIM To assess the importance of computed tomography in diagnosing acute pancreatitis and its related complications. MATERIALS AND METHODS A prospective study was conducted on 150 patients with clinically suspected pancreatitis. CT was performed on all the patients with Siemens Spiral CT scanner Sensation 16 slice. Oral contrast of was 1000 mL given one hour prior to the scan in the form of taking 250 mL every 15 mins. The CT severity index (CTSI and the necrosis point scoring was used to assess the severity of acute pancreatitis. All the complications related to acute pancreatitis were also assessed. RESULTS The CT analysis in the detection of acute pancreatitis showed the sensitivity of 100% and the positive predictive value of 97.3%. The severity index of acute pancreatitis based on the CT imaging had shown that majority of the patients are with moderate (60.6% level of acute pancreatitis. The necrosis point scoring showed that 54.6% of the patients had necrosis involving less than 30% of the pancreas. Among the various complications detected by CECT the commonest were pleural effusion and ascites. CONCLUSION CECT is the most important gold standard technique both for diagnosis as well as for predicting the prognosis in acute pancreatitis. The clinicians should routinely send the patient for the CT imaging whenever there is a suspicion of pancreatitis clinically.

  11. Peripancreatic vascular abnormalities complicating acute pancreatitis: contrast-enhanced helical CT findings

    Energy Technology Data Exchange (ETDEWEB)

    Mortele, Koenraad J. E-mail: kmortele@partners.org; Mergo, Patricia J.; Taylor, Helena M.; Wiesner, Walter; Cantisani, Vito; Ernst, Michael D.; Kalantari, Babak N.; Ros, Pablo R

    2004-10-01

    Objective: To determine the prevalence and morphologic helical computed tomography (CT) features of peripancreatic vascular abnormalities in patients with acute pancreatic inflammatory disease in correlation with the severity of the pancreatitis. Materials and methods: One hundred and fifty-nine contrast-enhanced helical CT scans of 100 consecutive patients with acute pancreatitis were retrospectively and independently reviewed by three observers. CT scans were scored using the CT severity index (CTSI): pancreatitis was graded as mild (0-2 points), moderate (3-6 points), and severe (7-10 points). Interobserver agreement for both the CT severity index and the presence of peripancreatic vascular abnormalities was calculated (K-statistic). Correlation between the prevalence of complications and the degree of pancreatitis was estimated using Fisher's exact test. Results: The severity of pancreatitis was graded as mild (n=59 scans), moderate (n=82 scans), and severe (n=18 scans). Venous abnormalities detected included splenic vein (SV) thrombosis (31 scans, 19 patients), superior mesenteric vein (SMV) thrombosis (20 scans, 14 patients), and portal vein (PV) thrombosis (17 scans, 13 patients). Arterial hemorrhage occurred in five patients (6 scans). In our series, no cases of arterial pseudoaneurysm formation were detected. The interobserver agreement range for scoring the degree of pancreatitis and the overall presence of major vascular abnormalities was 75.5-79.2 and 86.2-98.8%, respectively. The presence of the vascular abnormalities in correlation with the severity of pancreatitis was variable. Conclusion: Vascular abnormalities are relatively common CT findings in association with acute pancreatitis. The CT severity index is insufficiently accurate in predicting some of these complications since no statistically significant correlation between their prevalence and the severity of pancreatitis could be established.

  12. Effect of injection rate on contrast-enhanced MR angiography image quality: Modulation transfer function analysis.

    Science.gov (United States)

    Clark, Toshimasa J; Wilson, Gregory J; Maki, Jeffrey H

    2017-07-01

    Contrast-enhanced (CE)-MRA optimization involves interactions of sequence duration, bolus timing, contrast recirculation, and both R1 relaxivity and R2*-related reduction of signal. Prior data suggest superior image quality with slower gadolinium injection rates than typically used. A computer-based model of CE-MRA was developed, with contrast injection, physiologic, and image acquisition parameters varied over a wide gamut. Gadolinium concentration was derived using Verhoeven's model with recirculation, R1 and R2* calculated at each time point, and modulation transfer curves used to determine injection rates, resulting in optimal resolution and image contrast for renal and carotid artery CE-MRA. Validation was via a vessel stenosis phantom and example patients who underwent carotid CE-MRA with low effective injection rates. Optimal resolution for renal and carotid CE-MRA is achieved with injection rates between 0.5 to 0.9 mL/s and 0.2 to 0.3 mL/s, respectively, dependent on contrast volume. Optimal image contrast requires slightly faster injection rates. Expected signal-to-noise ratio varies with both contrast volume and cardiac output. Simulated vessel phantom and clinical carotid CE-MRA exams at an effective contrast injection rate of 0.4 to 0.5 mL/s demonstrate increased resolution. Optimal image resolution is achieved at intuitively low, effective injection rates (0.2-0.9 mL/s, dependent on imaging parameters and contrast injection volume). Magn Reson Med 78:357-369, 2017. © 2016 International Society for Magnetic Resonance in Medicine. © 2016 International Society for Magnetic Resonance in Medicine.

  13. Contrast-enhanced multiple-phase imaging features in hepatic epithelioid hemangioendothelioma

    Institute of Scientific and Technical Information of China (English)

    Ying Chen; Ri-Sheng Yu; Ling-Ling Qiu; Ding-Yao Jiang; Yan-Bin Tan; Yan-Biao Fu

    2011-01-01

    AIM: To investigate and review the contrast-enhanced multiple-phase computed tomography (CEMP CT) and magnetic resonance imaging (MRI) findings in patients with pathologically confirmed hepatic epithelioid hemangioendothelioma (HEHE). METHODS: Findings from imaging examinations in 8 patients (5 women and 3 men) with pathologically confirmed HEHE were retrospectively reviewed (CT images obtained from 7 patients and MR images obtained from 6 patients). The age of presentation varied from 27 years to 60 years (average age 39.8 years). RESULTS: There were two types of HEHE: multifocal type (n = 7) and diffuse type (n = 1). In the multifocal- type cases, there were 74 lesions on CT and 28 lesions on MRI with 7 lesions found with diffusion weighted imaging; 18 (24.3%) of 74 lesions on plain CT and 26 (92.9%) of 28 lesions on pre-contrast MRI showed the target sign. On CEMP CT, 28 (37.8%) of 74 lesions appeared with the target sign and a progressive-enhancement rim and 9 (12.2%) of 74 lesions displayed progressive enhancement, maintaining a state of persistent enhancement. On CEMP MRI, 27 (96.4%) of 28 lesions appeared with the target sign with a progressive-enhancement rim and 28 (100%) of 28 lesions displayed progressive-enhancement, maintaining a state of persistent enhancement. In the diffuse-type cases, an enlarged liver was observed with a large nodule appearing with persistent enhancement on CEMP CT and MRI. CONCLUSION: The most important imaging features of HEHE are the target sign and/or progressive enhancement with persistent enhancement on CEMP CT and MRI. MRI is advantageous over CT in displaying these imaging features.

  14. Edge Sharpening, Contrast Enhancement, And Feature Dependent Amplification In Inorganic Resist - A Simulation Study

    Science.gov (United States)

    Leung, Wingyu; Neureuther, Andrew R.; Oldham, William G.

    1983-11-01

    Computer simulation of the photodoping and lateral diffusion of silver during exposure is used to explore the theoretical potential of inorganic resists and to explore the extent to which it is realized in the Ge-Se resist system. The resist exposure is modeled as photodoping, silver into the substrate at the bottom of a bleachable sensitized layer. The silver concentration is assumed to be uniform vertically throughout the layer and allowed to diffuse laterally. The amount of photo-doping is proportional to the product of the intensity of light reaching the bottom of the sensitized layer and the local silver concentration. The layer is assumed to have a bleachable absorption proportional to the silver concentration , a nonbleachable absorption and a bleaching rate coefficient. A FORTRAN algorithm for solving the resulting coupled differential equations has been developed for use with the SAMPLE program. Both dynamic bleaching (hole burning) and lateral diffusion can lead to a sharper edge and/or higher contrast in the photodoped silver concentration than those in the incident exposure aerial image. For the 100A thick Ge-Se system at 0.75 urn features on the GCA DSW4800 stepper, the diffusion length is two times larger than the feature size, so that the contrast is equal to that of the aerial image at any exposure time. For large features with large transition region between the clear and dark fields contrast enhancement can be obtained using thick resists (>100 A sup 0) at the expanse of longer exposure time. For Ge-Se the lateral diffusion combined with photodoping saturation allow a feature dependent amplification of the relative silver concentrations for various feature sizes. This together, with the high contrast development process [1] allow inorganic resist to image well at low contrast exposure.

  15. Contrast-enhanced sonography versus biopsy for the differential diagnosis of thrombosis in hepatocellular carcinoma patients

    Institute of Scientific and Technical Information of China (English)

    Paolo Sorrentino; Salvatore D'Angelo; Luciano Tarantino; Umberto Ferbo; Alessandra Bracigliano; Raffaela Vecchione

    2009-01-01

    AIM: To clarify which method has accuracy: 2nd generation contrast-enhanced ultrasound or biopsy of portal vein thrombus in the differential diagnosis of portal vein thrombosis. METHODS: One hundred and eighty-six patients with hepatocellular carcinoma and portal vein thrombosis underwent in blinded fashion a 2nd generation contrastenhanced ultrasound and biopsy of portal vein thrombus; both results were examined on the basis of the follow-up of patients compared to reference-standard. RESULTS: One hundred and eight patients completed the study. Benign thrombosis on 2nd generation contrast- enhanced ultrasound was characterised by progressive hypoenhancing of the thrombus; in malignant portal vein thrombosis there was a precocious homogeneous enhancement of the thrombus. On follow-up there were 50 of 108 patients with benign thrombosis: all were correctly diagnosed by both methods. There were 58 of 108 patients with malignant thrombosis: amongst these, 52 were correctly diagnosed by both methods, the remainder did not present malignant cells on portal vein thrombus biopsy and showed on 2nd generation contrast-enhanced ultrasound an inhomogeneous enhancement pattern. A new biopsy during the follow-up, guided to the area of thrombus that showed up on 2nd generation contrast-enhanced ultrasound, demonstrated an enhancing pattern indicating malignant cells. CONCLUSION: In patients with hepatocellular carcinoma complicated by portal vein thrombosis, 2nd generation contrast-enhanced ultrasound of portal vein thrombus is very useful in assessing the benign or malignant nature of the thrombus. Puncture biopsy of thrombus is usually accurate but presents some sampling errors, so, when pathological results are required, 2nd generation contrast-enhanced ultrasound could guide the sampling needle to the correct area of the thrombus.

  16. Detection of postoperative residual cholesteatoma with delayed contrast-enhanced MR imaging: initial findings

    Energy Technology Data Exchange (ETDEWEB)

    Williams, Marc T.; Heran, Francoise; Lafitte, Francois; Elmaleh-Berges, Monique; Piekarski, Jean-Daniel [Department of Medical Imaging, Fondation Ophthalmologique Adolphe de Rothschild, 25, rue Manin, 75940 Paris (France); Ayache, Denis [Department of Otorhinolaryngology, Fondation Ophthalmologique Adolphe de Rothschild, 25, rue Manin, 75940 Paris (France); Alberti, Corinne [Department of Biostatistics, Hopital Saint-Louis, 1 Avenue Claude Vellefaux, 75010 Paris (France)

    2003-01-01

    Our objective was to assess the value of delayed contrast-enhanced T1-weighted spin-echo MR imaging in the detection of residual cholesteatoma in patients who have undergone canal wall-up tympanoplasty procedure. The MR imaging was obtained prior to revision surgery in 18 patients with opacity of the post-operative cavity at CT examination 12-18 months after canal wall-up tympanoplasty. In each patient the following was performed: precontrast T1- and T2-weighted images; and early and delayed contrast-enhanced axial and coronal T1-weighted imaging. Early and delayed MR imaging results were separately compared with surgical second-look findings. Sensitivity, specificity, and predictive values were evaluated for early and delayed post-contrast MR imaging, compared with second-look surgery findings. A residual cholesteatoma was correctly identified in 8 of 9 cases with delayed contrast-enhanced T1-weighted MR imaging. Mean sensitivity, specificity, positive predictive value, and interobserver agreement (evaluated by kappa statistics) were, respectively, 85.2, 92.6, 92.6%, and kappa=0.78 for the delayed contrast-enhanced MR imaging technique. The same parameters were, respectively, 96.3, 33.3, 60.6, and 0.30 for the early contrast-enhanced T1-weighted MR images. We conclude that delayed contrast-enhanced T1-weighted MR imaging is reliable for the detection of residual cholesteatomas of the middle ear in patients who have undergone canal wall-up tympanoplasty. (orig.)

  17. Modeling of the contrast-enhanced perfusion test in liver based on the multi-compartment flow in porous media

    CERN Document Server

    Rohan, Eduard; Jonášová, Alena

    2016-01-01

    The paper deals with modeling the liver perfusion intended to improve quantitative analysis of the tissue scans provided by the contrast-enhanced computed tomography (CT). For this purpose, we developed a model of dynamic transport of the contrast fluid through the hierarchies of the perfusion trees. Conceptually, computed time-space distributions of the so-called tissue density can be compared with the measured data obtained from CT; such a modeling feedback can be used for model parameter identification. The blood flow is characterized at several scales for which different models are used. Flows in upper hierarchies represented by larger branching vessels are described using simple 1D models based on the Bernoulli equation extended by correction terms to respect the local pressure losses. To describe flows in smaller vessels and in the tissue parenchyma, we propose a 3D continuum model of porous medium defined in terms of hierarchically matched compartments characterized by hydraulic permeabilities. The 1D ...

  18. An Algorithm of Image Contrast Enhancement Based on Pixels Neighborhood’s Local Feature

    Directory of Open Access Journals (Sweden)

    Chen Yan

    2013-12-01

    Full Text Available In this study, we proposed an algorithm of Image Contrast enhancement based on local feature to acquire edge information of image, remove Ray Imaging noise and overcome edge blurry and other defects. This method can extract edge features and finish contrast enhancement in varying degrees for pixels neighborhood with different characteristics by using neighborhood local variance and complexity function, which can achieve local features enhancement. The stimulation shows that the method can not only enhance the contrast of the entire image, but also effectively preserves image edge information and improve image quality.

  19. Parametric based morphological transformation for contrast enhancement of color images in poor-lighting

    Indian Academy of Sciences (India)

    Atluri Srikrishna; M Pompapathi; G Srinivasa Rao

    2015-04-01

    The objective of contrast operators consists in normalizing the gray levels of the input image for the purpose of avoiding abrupt changes in intensity among different regions. In this paper morphological transformations are used to detect the background in color images characterized by poor lighting. The disadvantage of contrast enhancement as studied in previous contrast enhancement algorithms is over illumination. An efficient algorithm is introduced to tackle the problem of over illumination by controlling the intensities at dark and bright regions of an image and preserve the geometry of the object. Finally the performance of the proposed algorithm is illustrated through the processing of gray scale images and color images with different backgrounds.

  20. Photonic crystal slabs for surface contrast enhancement in microscopy of transparent objects.

    Science.gov (United States)

    Nazirizadeh, Yousef; Becker, Tim; Reverey, Julia; Selhuber-Unkel, Christine; Rapoport, Daniel H; Lemmer, Uli; Gerken, Martina

    2012-06-18

    In optical microscopy the contrast of transparent objects achieved with conventional methods is often not satisfactory, for example for the automated recognition of cells. In this paper we present a nano-optical label-free approach for contrast enhancement based on photonic crystal slabs (PCS) as the specimen holder. Quasi-guided modes inside these structures cause an intrinsic color of the PCS, which strongly depends on the wavelength and the quality factor of the optical mode. Objects on the surface of the PCS experience a significant color and intensity contrast enhancement, as they change properties of the optical modes.

  1. Performance comparison of multi-detector detection statistics in targeted compact binary coalescence GW search

    CERN Document Server

    Haris, K

    2016-01-01

    Global network of advanced Interferometric gravitational wave (GW) detectors are expected to be on-line soon. Coherent observation of GW from a distant compact binary coalescence (CBC) with a network of interferometers located in different continents give crucial information about the source such as source location and polarization information. In this paper we compare different multi-detector network detection statistics for CBC search. In maximum likelihood ratio (MLR) based detection approaches, the likelihood ratio is optimized to obtain the best model parameters and the best likelihood ratio value is used as statistic to make decision on the presence of signal. However, an alternative Bayesian approach involves marginalization of the likelihood ratio over the parameters to obtain the average likelihood ratio. We obtain an analytical expression for the Bayesian statistic using the two effective synthetic data streams for targeted search of non-spinning compact binary systems with an uninformative prior on...

  2. Diagnostic accuracy and tolerability of contrast enhanced CT colonoscopy in symptomatic patients with increased risk for colorectal cancer

    Energy Technology Data Exchange (ETDEWEB)

    Ozsunar, Yelda [Department of Radiology, School of Medicine, Adnan Menderes University, Aydin (Turkey)], E-mail: yozsunar@adu.edu.tr; Coskun, Guelten [Izmir Ataturk Egitim ve Arastirma Hastanesi, Izmir (Turkey); Delibas, Naciye; Uz, Burcin [Department of Radiology, School of Medicine, Adnan Menderes University, Aydin (Turkey); Yuekselen, Vahit [Department of Gastroenterology, School of Medicine, Adnan Menderes University, Aydin (Turkey)

    2009-09-15

    Objective: We compared the accuracy and tolerability of intravenous contrast enhanced spiral computed tomography colonography (CTC) and optical colonoscopy (OC) for the detection of colorectal neoplasia in symptomatic patients for colorectal neoplasia. Methods: A prospective study was performed in 48 patients with symptomatic patients with increased risk for colorectal cancer. Spiral CTC was performed in supine and prone positions after colonic cleansing. The axial, 2D MPR and virtual endoluminal views were analyzed. Results of spiral CTC were compared with OC which was done within 15 days. The psychometric tolerance test was asked to be performed for both CTC and colonoscopy after the procedure. Results: Ten lesions in 9 of 48 patients were found in CTC and confirmed with OC. Two masses and eight polyps, consisted of 1 tubulovillous, 1 tubular, 2 villous adenoma, 4 adenomatous polyp, 4 adenocarcinoma, were identified. Lesion prevalence was 21%. Sensitivity, specificity, accuracy, positive and negative predictive values were found 100%, 87%, 89%, 67% and 100%, respectively. Psychometric tolerance test showed that CTC significantly more comfortable comparing with OC (p = 0.00). CTC was the preferred method in 37% while OC was preferred in 6% of patients. In both techniques, the most unpleasant part was bowel cleansing. Conclusion: Contrast enhanced CTC is a highly accurate method in detecting colorectal lesions. Since the technique was found to be more comfortable and less time consuming compare to OE, it may be preferable in management of symptomatic patients with increased risk for colorectal cancer.

  3. Dynamic Contrast-Enhanced Ultrasound of Colorectal Liver Metastases as an Imaging Modality for Early Response Prediction to Chemotherapy

    Directory of Open Access Journals (Sweden)

    Marie Benzon Mogensen

    2017-06-01

    Full Text Available Our aim was to investigate whether dynamic contrast-enhanced ultrasound (DCE-US can detect early changes in perfusion of colorectal liver metastases after initiation of chemotherapy. Newly diagnosed patients with colorectal cancer with liver metastases were enrolled in this explorative prospective study. Patients were treated with capecitabine or 5-fluorouracil-based chemotherapy with or without bevacizumab. DCE-US was performed before therapy (baseline and again 10 days after initiation of treatment. Change in contrast-enhancement in one liver metastasis (indicator lesion was measured. Treatment response was evaluated with a computed tomography (CT scan after three cycles of treatment and the initially observed DCE-US change of the indicator lesion was related to the observed CT response. Eighteen patients were included. Six did not complete three series of chemotherapy and the evaluation CT scan, leaving twelve patients for analysis. Early changes in perfusion parameters using DCE-US did not correlate well with subsequent CT changes. A subgroup analysis of eight patients receiving bevacizumab, however, demonstrated a statistically significant correlation (p = 0.045 between early changes in perfusion measures of peak enhancement at DCE-US and tumor shrinkage at CT scan. The study indicates that early changes in DCE-US perfusion measures may predict subsequent treatment response of colorectal liver metastases in patients receiving bevacizumab.

  4. Skeletonization approach for characterization of benign vs. malignant single thyroid nodules using 3D contrast enhanced ultrasound

    Science.gov (United States)

    Molinari, Filippo; Mantovani, Alice; Deandrea, Maurilio; Limone, Paolo; Garberoglio, Roberto; Suri, Jasjit S.

    2011-03-01

    High-resolution ultrasonography (HRUS) has potentialities in differential diagnosis between malignant and benign thyroid lesions, but interpretative pitfalls remain and accuracy is still poor. We developed an image processing technique for characterizing the intra-nodular vascularization of thyroid lesions. Twenty nodules (ten malignant) were analyzed by 3-D contrast-enhanced ultrasound imaging. The 3-D volumes were preprocessed and skeletonized. Seven vascular parameters were computed on the skeletons: number of vascular trees (NT); vascular density (VD); number of branching nodes (or branching points) (NB); mean vessel radius (MR); 2-D (DM) and 3-D (SOAM) tortuosity; and inflection count metric (ICM). Results showed that the malignant nodules had higher values of NT (83.1 vs. 18.1), VD (00.4 vs. 0.01), NB (1453 vs. 552), DM (51 vs. 18), ICM (19.9 vs. 8.7), and SOAM (26 vs. 11). Quantification of nodular vascularization based on 3-D contrast-enhanced ultrasound and skeletonization could help differential diagnosis of thyroid lesions.

  5. Investigation of optimal parameters for penalized maximum-likelihood reconstruction applied to iodinated contrast-enhanced breast CT

    Science.gov (United States)

    Makeev, Andrey; Ikejimba, Lynda; Lo, Joseph Y.; Glick, Stephen J.

    2016-03-01

    Although digital mammography has reduced breast cancer mortality by approximately 30%, sensitivity and specificity are still far from perfect. In particular, the performance of mammography is especially limited for women with dense breast tissue. Two out of every three biopsies performed in the U.S. are unnecessary, thereby resulting in increased patient anxiety, pain, and possible complications. One promising tomographic breast imaging method that has recently been approved by the FDA is dedicated breast computed tomography (BCT). However, visualizing lesions with BCT can still be challenging for women with dense breast tissue due to the minimal contrast for lesions surrounded by fibroglandular tissue. In recent years there has been renewed interest in improving lesion conspicuity in x-ray breast imaging by administration of an iodinated contrast agent. Due to the fully 3-D imaging nature of BCT, as well as sub-optimal contrast enhancement while the breast is under compression with mammography and breast tomosynthesis, dedicated BCT of the uncompressed breast is likely to offer the best solution for injected contrast-enhanced x-ray breast imaging. It is well known that use of statistically-based iterative reconstruction in CT results in improved image quality at lower radiation dose. Here we investigate possible improvements in image reconstruction for BCT, by optimizing free regularization parameter in method of maximum likelihood and comparing its performance with clinical cone-beam filtered backprojection (FBP) algorithm.

  6. Prognostic value of multi-detector computed tomography in asymptomatic aortic valve stenosis

    DEFF Research Database (Denmark)

    Larsen, Linnea Hornbech; Kofoed, Klaus Fuglsang; Carstensen, Helle Gervig

    2016-01-01

    was defined as indication for aortic valve replacement (AVR) determined by the treating physician or sudden cardiac death. RESULTS: The mean age was 72 (8) years, 27% were women, mean AVA by TTE was 1.01 (0.30) cm(2). Median follow up time was 27 (IQR 19-44) months. Forty seven patients (41%) developed...... indication for AVR. No patients suffered a sudden cardiac death. AVA and aortic valve calcification were significant univariable predictors of AVR when measured by both TTE and MDCT, whereas left ventricular mass was only significant measured by MDCT. Significant coronary artery disease by MDCT tended...... to predict future indication for AVR, but this did not reach statistical significance (HR: 1.79 (95% CI 0.96-3.44), p=0.08). CONCLUSION: MDCT derived AVA can be of use as an alternative to TTE derived AVA in patients with asymptomatic AS to predict future clinical indication for AVR....

  7. Multi-detector computed tomography (MDCT findings of chemotherapy induced hepatic chan

    Directory of Open Access Journals (Sweden)

    Sieza Samir Abd-Allah

    2016-09-01

    Results: Forty patients (32 females and 8 males had hepatic changes due to effect of chemotherapy. The most common CT finding was fatty liver. Hepatic fatty changes were detected in 36/40 patients. These fatty changes were diffuse, focal fatty and diffuse with fatty spare area. Four patients had capsular retraction: 1 patient with HD and 3 patients with metastatic cancer breast. Veno-occlusive disease and biliary sclerosis were not detected.

  8. Serial changes of coronary atherosclerotic plaque: Assessment with 64-slice multi-detector computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Eun Young; Kang, Doo Kyoung; Sun, Joo Sung; Choi, So Yeon [Ajou University School of Medicine, Suwon (Korea, Republic of)

    2013-12-15

    Evaluate the progression of coronary atherosclerotic plaque during follow-up, and its association with cardiovascular risk factors. Fifty-six atherosclerotic patients with plaque were enrolled in this retrospective study. Patient's plaque was detected on repeat 64-slice multidetector CT scans with a mean interval of 25 ± 10 months changes in calcified and non-calcified plaque volumes and cardiovascular risk factors were assessed over time. Absolute and relative changes in plaque volume were compared, and the association between rapid progression and cardiovascular risk factors was determined. Diameter of the stenosis, length, calcified and non-calcified lesion plaque volumes increased significantly on follow-up CT. Absolute and relative annual changes in plaque volumes were significantly greater in non-calcified plaque (median, 22.7 mm{sup 3}, 90.4%) than in calcified plaque (median, 0.7 mm{sup 3}, 0%). Obesity, smoking, hypertension, hypercholesterolemia, and low high-density lipoprotein were significant predictors of progression of non-calcified plaque. Progression of calcified plaque was not associated with any cardiovascular risk factors. Coronary plaque volume increased significantly on follow-up CT. The rate of progression is related to non-calcified plaque than to calcified plaque. Cardiovascular risk factors are independently associated with the rapid progression of non-calcified plaque volume, but not associated with the progression of calcified plaque.

  9. Non-contrast enhanced MRI for evaluation of breast lesions: comparison of non-contrast enhanced high spectral and spatial resolution (HiSS) images vs. contrast enhanced fat-suppressed images

    Science.gov (United States)

    Medved, Milica; Fan, Xiaobing; Abe, Hiroyuki; Newstead, Gillian M.; Wood, Abbie M.; Shimauchi, Akiko; Kulkarni, Kirti; Ivancevic, Marko K.; Pesce, Lorenzo L.; Olopade, Olufunmilayo I.; Karczmar, Gregory S.

    2011-01-01

    RATIONALE AND OBJECTIVES To evaluate high spectral and spatial resolution (HiSS) MRI for diagnosis of breast cancer without injection of contrast media: to compare the performance of pre-contrast HiSS images to conventional contrast-enhanced fat-suppressed T1-weighted images, based on image quality and in the task of classifying benign and malignant breast lesions. MATERIALS AND METHODS Ten benign and 44 malignant lesions were imaged at 1.5T with HiSS (pre-contrast administration) and conventional fat-suppressed imaging (3–10 min post-contrast). This set of 108 images, after randomization, was evaluated by three experienced radiologists blinded to the imaging technique. BIRADS morphologic criteria (lesion shape; lesion margin; internal signal intensity pattern) and final assessment were used to measure reader performance. Image quality was evaluated based on boundary delineation and quality of fat suppression. An overall probability of malignancy was assigned to each lesion for HiSS and conventional images separately. RESULTS On boundary delineation and quality of fat-suppression, pre-contrast HiSS scored similarly to conventional post-contrast MRI. On benign vs. malignant lesion separation, there was no statistically significant difference in ROC performance between HiSS and conventional MRI, and HiSS met a reasonable non-inferiority condition. CONCLUSION Pre-contrast HiSS imaging is a promising approach for showing lesion morphology without blooming and other artifacts caused by contrast agents. HiSS images could be used to guide subsequent dynamic contrast-enhanced MRI scans, to maximize spatial and temporal resolution in suspicious regions. HiSS MRI without contrast agent injection may be particularly important for patients at risk for contrast-induced nephrogenic systemic fibrosis, or allergic reactions. PMID:21962476

  10. Dynamic contrast-enhanced MRI for monitoring response to neoadjuvant chemotherapy in breast cancer

    NARCIS (Netherlands)

    Loo, C.E.

    2016-01-01

    The general aim of this thesis is to investigate the role of dynamic contrast-enhanced MRI in monitoring response of breast cancer during neoadjuvant chemotherapy. The role of MRI with respect to achieving personalized breast cancer treatment by improving response monitoring is examined. Our finding

  11. Dynamic contrast-enhanced (DCE) imaging for tumor delineation in prostate cancer

    NARCIS (Netherlands)

    Korporaal, J.G.

    2011-01-01

    Dynamic contrast-enhanced (DCE) MR imaging is frequently used for the detection and localization of prostate tumors. After injection of a bolus of contrast agent into the blood circulation, the behavior of the contrast agent in the prostate can be measured by repetitive imaging of the prostate. Pros

  12. Review of dynamic contrast-enhanced ultrasound guidance in ablation therapy for hepatocellular carcinoma

    Institute of Scientific and Technical Information of China (English)

    Yasunori Minami; Masatoshi Kudo

    2011-01-01

    Local ablative techniques-percutaneous ethanol injection, microwave coagulation therapy and radiofrequency ablation (RFA)-have been developed to treat unresectable hepatocellular carcinoma (HCC). The success rate of percutaneous ablation therapy for HCC depends on correct targeting of the tumor via an imaging technique. However, probe insertion often is not completely accurate for small HCC nodules, which are poorly defined on conventional B-mode ultrasound (US) alone. Thus, multiple sessions of ablation therapy are frequently required in difficult cases. By means of two breakthroughs in US technology, harmonic imaging and the development of second-generation contrast agents, dynamic contrast-enhanced harmonic US imaging with an intravenous contrast agent can depict tumor vascularity sensitively and accurately, and is able to evaluate small hypervascular HCCs even when B-mode US cannot adequately characterize the tumors. Therefore, dynamic contrast-enhanced US can facilitate RFA electrode placement in hypervascular HCC, which is poorly depicted by B-mode US. The use of dynamic contrast-enhanced US guidance in ablation therapy for liver cancer is an efficient approach. Here, we present an overview of the current status of dynamic contrast-enhanced US-guided ablation therapy, and summarize the current indications and outcomes of reported clinical use in comparison with that of other modalities.

  13. Contrast enhanced digital mammography: Is it useful in detecting lesions in edematous breast?

    Directory of Open Access Journals (Sweden)

    Noha Abd ElShafy ElSaid

    2015-09-01

    Conclusion: Dual-energy contrast-enhanced digital mammography is a useful technique in identification of lesions in mammographically dense edematous breasts and proved to be a useful tool in the follow-up of cases presenting by edema after conservative breast surgery and chemotherapy.

  14. Abducens nerve enhancement demonstrated by multiplanar reconstruction of contrast-enhanced three-dimensional MRI

    Energy Technology Data Exchange (ETDEWEB)

    Hosoya, T.; Adachi, M.; Sugai, Y. [Dept. of Radiology, Yamagata University School of Medicine (Japan); Yamaguchi, K.; Yamaguchi, K. [Dept. of Ophthalmology, Yamagata University School of Medicine (Japan); Kato, T. [3. Dept. of Internal Medicine, Yamagata University School of Medicine (Japan)

    2001-04-01

    We describe contrast enhancement of the cisternal portion of the abducens nerve and discuss its clinical significance. We examined 67 patients with ophthalmoplegia using contrast-enhanced 3-dimensional (3D) MRI with multiplanar reconstruction along the nerves and found 16 patients (ten men, six women), aged 10-73 years (mean 34.4 years), with contrast enhancement of the abducens nerve. Of the 36 patients who had an abducens palsy, 14 (39 %) showed contrast enhancement. In the 16 patients, 23 abducens nerves enhanced; 13 were symptomatic and 10 asymptomatic at the time. The causes were disseminated tumour (1), an inflammatory process (3), trauma (2), ischaemia (2) and autoimmune diseases (8), such as the Miller Fisher syndrome, acute ophthalmoparesis, polyneuropathy and multiple sclerosis. Abducens and/or oculomotor nerve enhancement was the only abnormality on MRI in the patients with traumatic or ischaemic neuropathy or autoimmune diseases. There were 14 patients who recovered fully within 1-6 months after treatment, and resolution of the enhancement correlated well with recovery. (orig.)

  15. Detection of anomalous splenic artery aneurysms with three-dimensional contrast-enhanced MR angiography.

    Science.gov (United States)

    Liu, Qi; Lu, Jian Ping; Wang, Fei; Wang, Li; Jin, Ai Guo; Wang, Jian; Tian, Jian Min

    2009-11-01

    Aneurysms of the splenic artery which arise anomalously from the superior mesenteric artery are extremely rare but clinically important because of their life-threatening hemorrhage. Diagnostic imaging plays an important role in the diagnosis and conducting treatment strategy. The aim of this study was to evaluate the detection of anomalous splenic artery aneurysms with 3D contrast-enhanced MR angiography. 3D contrast-enhanced MR angiography was performed in six patients with anomalous splenic artery aneurysms. The mean diameter of six aneurysms was 3.9 cm. All of them were saccular and located at the origin of the splenic artery that arose anomalously from the root of the superior mesenteric artery. 3D contrast-enhanced MR angiography clearly demonstrated the aneurysm's location, size, morphology, visceral arterial variations, and was superior to DSA in three-dimensional display of the aneurysm and its relationship with surrounding vessels and organs. Two patients underwent open vascular surgery and three endovascular procedure. 3D contrast-enhanced MR angiography is a noninvasive and accurate technique for diagnosis of anomalous splenic artery aneurysms. Its 3D anatomic information is very helpful for treatment planning. It can be used as one of the first choice examinations for anomalous splenic artery aneurysms.

  16. Contrast-enhanced dual-energy mammography : a promising new imaging tool in breast cancer detection

    NARCIS (Netherlands)

    Lalji, Ulrich; Lobbes, Marc

    2014-01-01

    Contrast-enhanced dual-energy mammography (CEDM) is a promising new breast imaging tool for breast cancer detection. In CEDM, an iodine-based contrast agent is intravenously administered and subsequently, dual-energy mammography is performed. This results in a set of images containing both a regular

  17. Contrast-enhanced dynamic MR imaging of postmolar gestational trophoblastic disease

    Energy Technology Data Exchange (ETDEWEB)

    Yamashita, Y. [Depts. of Radiology and Obstetrics and Gynecology, Kumamoto Univ. School of Medicine (Japan); Torashima, M. [Depts. of Radiology and Obstetrics and Gynecology, Kumamoto Univ. School of Medicine (Japan); Takahashi, M. [Depts. of Radiology and Obstetrics and Gynecology, Kumamoto Univ. School of Medicine (Japan); Mizutani, H. [Depts. of Radiology and Obstetrics and Gynecology, Kumamoto Univ. School of Medicine (Japan); Miyazaki, K. [Depts. of Radiology and Obstetrics and Gynecology, Kumamoto Univ. School of Medicine (Japan); Matsuura, K. [Depts. of Radiology and Obstetrics and Gynecology, Kumamoto Univ. School of Medicine (Japan); Okamura, H. [Depts. of Radiology and Obstetrics and Gynecology, Kumamoto Univ. School of Medicine (Japan)

    1995-03-01

    Conventional spin-echo (SE) and contrast-enhanced dynamic MR imaging were performed on a 1.5 T superconductive unit for evaluation of myometrial lesions in postmolar gestational trophoblastic disease (GTD) in 10 women. MR imaging was done at the time of the initial examination (n=10), during (n=6), and after repeated courses of chemotherapy (n=10). The T2-weighted SE image revealed an enlarged uterus (n=7), disappearance of zonal anatomy (n=6), and heterogeneous signal intensities (n=8) with prominent flow voids (n=7). However, these abnormalities remained after repeated courses of chemotherapy, when the S-{beta}-HCG level returned to the normal range. Myometrial lesions characteristically had marked enhancement with areas of unenhancement on dynamic MR images in patients with highly elevated S-{beta}-HCG. Areas of contrast enhancement correlated with changes in S-{beta}-HCG level. The enhancement was reduced with decrease in S-{beta}-HCG level after repeated courses of chemotherapy. Six of 8 masses seen on T2-weighted images proved to be active trophoblastic lesions and 2 masses proved to be hematoma or necrosis. In 2 patients, abnormal myometrial lesions were detected only on contrast-enhanced dynamic MR imaging. These preliminary data indicate that contrast-enhanced dynamic MR imaging more clearly demonstrates myometrial involvement of postmolar GTD than conventional SE imaging. (orig.).

  18. Dynamic contrast-enhanced (DCE) imaging for tumor delineation in prostate cancer

    NARCIS (Netherlands)

    Korporaal, J.G.

    2011-01-01

    Dynamic contrast-enhanced (DCE) MR imaging is frequently used for the detection and localization of prostate tumors. After injection of a bolus of contrast agent into the blood circulation, the behavior of the contrast agent in the prostate can be measured by repetitive imaging of the prostate. Pros

  19. Identifying the association between contrast enhancement pattern, surgical resection, and prognosis in anaplastic glioma patients

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Yinyan; Jiang, Tao [Capital Medical University, Department of Neurosurgery, Beijing Tiantan Hospital, Beijing (China); Capital Medical University, Beijing Neurosurgical Institute, Beijing (China); Wang, Kai; Li, Shaowu; Ma, Jun [Capital Medical University, Department of Neuroradiology, Beijing Tiantan Hospital, Beijing (China); Wang, Jiangfei [Capital Medical University, Department of Neurosurgery, Beijing Tiantan Hospital, Beijing (China); Dai, Jianping [Capital Medical University, Beijing Neurosurgical Institute, Beijing (China); Capital Medical University, Department of Neuroradiology, Beijing Tiantan Hospital, Beijing (China)

    2016-04-15

    Contrast enhancement observable on magnetic resonance (MR) images reflects the destructive features of malignant gliomas. This study aimed to investigate the relationship between radiologic patterns of tumor enhancement, extent of resection, and prognosis in patients with anaplastic gliomas (AGs). Clinical data from 268 patients with histologically confirmed AGs were retrospectively analyzed. Contrast enhancement patterns were classified based on preoperative T1-contrast MR images. Univariate and multivariate analyses were performed to evaluate the prognostic value of MR enhancement patterns on progression-free survival (PFS) and overall survival (OS). The pattern of tumor contrast enhancement was associated with the extent of surgical resection in AGs. A gross total resection was more likely to be achieved for AGs with focal enhancement than those with diffuse (p = 0.001) or ring-like (p = 0.024) enhancement. Additionally, patients with focal-enhanced AGs had a significantly longer PFS and OS than those with diffuse (log-rank, p = 0.025 and p = 0.031, respectively) or ring-like (log-rank, p = 0.008 and p = 0.011, respectively) enhanced AGs. Furthermore, multivariate analysis identified the pattern of tumor enhancement as a significant predictor of PFS (p = 0.016, hazard ratio [HR] = 1.485) and OS (p = 0.030, HR = 1.446). Our results suggested that the contrast enhancement pattern on preoperative MR images was associated with the extent of resection and predictive of survival outcomes in AG patients. (orig.)

  20. An Algorithmic Analysis of Variational Models for Perceptual Local Contrast Enhancement

    Directory of Open Access Journals (Sweden)

    Sira Ferradans

    2015-07-01

    Full Text Available Color cast cancellation and local contrast enhancement are very important problems in computervision. In this paper we review the algorithm proposed by Palma-Amestoy et al. [A perceptuallyinspired variational framework for color enhancement, IEEE Transactions on Pattern Analysisand Machine Intelligence, 21 (2009, pp. 458–474], present results and evaluate the impact of achange in the parameters.

  1. Improved dosimetry in prostate brachytherapy using high resolution contrast enhanced magnetic resonance imaging: a feasibility study

    Science.gov (United States)

    Morancy, Tye; Kaplan, Irving; Qureshi, Muhammad M.; Hirsch, Ariel E.; Rofksy, Neil M.; Holupka, Edward; Oismueller, Renee; Hawliczek, Robert; Helbich, Thomas H.; Bloch, B. Nicolas

    2014-01-01

    Purpose To assess detailed dosimetry data for prostate and clinical relevant intra- and peri-prostatic structures including neurovascular bundles (NVB), urethra, and penile bulb (PB) from postbrachytherapy computed tomography (CT) versus high resolution contrast enhanced magnetic resonance imaging (HR-CEMRI). Material and methods Eleven postbrachytherapy prostate cancer patients underwent HR-CEMRI and CT imaging. Computed tomography and HR-CEMRI images were randomized and 2 independent expert readers created contours of prostate, intra- and peri-prostatic structures on each CT and HR-CEMRI scan for all 11 patients. Dosimetry data including V100, D90, and D100 was calculated from these contours. Results Mean V100 values from CT and HR-CEMRI contours were as follows: prostate (98.5% and 96.2%, p = 0.003), urethra (81.0% and 88.7%, p = 0.027), anterior rectal wall (ARW) (8.9% and 2.8%, p < 0.001), left NVB (77.9% and 51.5%, p = 0.002), right NVB (69.2% and 43.1%, p = 0.001), and PB (0.09% and 11.4%, p = 0.005). Mean D90 (Gy) derived from CT and HR-CEMRI contours were: prostate (167.6 and 150.3, p = 0.012), urethra (81.6 and 109.4, p = 0.041), ARW (2.5 and 0.11, p = 0.003), left NVB (98.2 and 58.6, p = 0.001), right NVB (87.5 and 55.5, p = 0.001), and PB (11.2 and 12.4, p = 0.554). Conclusions Findings of this study suggest that HR-CEMRI facilitates accurate and meaningful dosimetric assessment of prostate and clinically relevant structures, which is not possible with CT. Significant differences were seen between CT and HR-CEMRI, with volume overestimation of CT derived contours compared to HR-CEMRI. PMID:25834576

  2. 64-row multi-dector computed tomography coronary image from a center with early experience: first illustration of learning curve

    Institute of Scientific and Technical Information of China (English)

    Sze Piaw CHIN; Tiong Kiam ONG; Wei Ling CHAN; Chee Khoon LIEW; M.Tobias Seyfarth; Fong Yean Yip ALAN; Houng Bang LIEW; Kui Hian SIM

    2006-01-01

    Background and objectives The recent joint ACCF/AHA clinical competence statement on cardiac imaging with multi-detector computed tomography recommended a minimum of 6 months training and 300 contrast examinations, of which the candidate must be directly involved in at least 100 studies. Whether this is adequate to become proficient in interpretation of coronary computed tomogsignificant coronary stenosis in a center with 1 year's experience using a 64-row scanner. Methods A total of 778 patients underwent contrast-enhanced CTA between January and December 2005. Out of these patients, 301 patients also underwent contrast-enhanced conventional coronary angiography (CCA). These patients were divided into 4 groups according to the time the examination was underwent. Group Q1: first quarter of the year (n=20), Group Q2: second quarter (n=128), Group Q3: third quarter (n=134), and Group Results The sensitivity, specificity, positive, and negative predictive values were Q1 - 64%, 89%, 49% and 94%, respectively; Q2 -79%, 96%, 74% and 97%, respectively; Q3 - 78%, 96%, 74%, 97%, respectively, and Q4 - 100% for all. Conclusions In a center with formal training and high caseload, our accuracy in CTA analysis reached a plateau after 6 months experience. Test-bolus protocols produce better image quality and can improve accuracy. New centers embarking on CTA will need to overcome an initial 6-month learning curve depending upon the caseload during which time they should consider correlation with CCA.

  3. Contrast-enhanced MR imaging of the endolymphatic sac in patients with sudden hearing loss

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    Naganawa, Shinji; Koshikawa, Tokiko; Fukatsu, Hiroshi; Ishigaki, Takeo [Department of Radiology, Nagoya University School of Medicine (Japan); Nakashima, Tsutomu [Department of Otolayngology, Nagoya University School of Medicine (Japan); Ichinose, Nobuyasu [Toshiba Nasu Operations, Tochigi (Japan)

    2002-05-01

    Our objective was to evaluate the frequency of contrast enhancement of the endolymphatic sac in patients with sudden hearing loss. Forty consecutive patients with sudden sensorineural hearing loss (20 males and 20 females; age range 11-82 years), 40 age-matched control subjects, and 5 patients with Meniere's disease were examined using the same imaging protocol on a 1.5-T MR system. Pre- and post-contrast-enhanced T1-weighted 3D spoiled gradient-echo sequence (3D SPGR; TR/TE=23/10 ms, no. of excitations=1, flip angle=30 ) images were obtained using a voxel size of 0.6 x 0.7 x 0.8 mm{sup 3}. Contrast enhancement in the area of the endolymphatic sac was assessed by two radiologists, and the frequency of contrast enhancement was compared between the three study groups. Enhancement of the ipsilateral endolymphatic sac was observed in 30 of the 40 patients with sudden hearing loss (75%). Twenty of these 30 patients also showed enhancement on the contralateral side, and 1 patient showed enhancement only on the contralateral side. Only 1 of the 5 patients with Meniere's disease showed enhancement. Nine of the 40 control subjects (22.5%) showed enhancement (bilateral enhancement in 5 subjects, unilateral in 4). The frequency of enhancement in patients with sudden hearing loss was significantly higher than that in control subjects (P<0.0001) or patients with Meniere's disease (P<0.05). The frequency of contrast enhancement of the endolymphatic sac is significantly increased in patients with sudden hearing loss, but further study is necessary to clarify the relationship between this finding and the pathophysiology of sudden hearing loss. (orig.)

  4. Contrast-enhanced endoscopic ultrasound in discrimination between benign and malignant mediastinal and abdominal lymph nodes.

    Science.gov (United States)

    Hocke, Michael; Menges, Markus; Topalidis, Theodor; Dietrich, Christoph F; Stallmach, Andreas

    2008-04-01

    Enlarged lymph nodes in the mediastinum reflect neoplastic, infectious or other diseases. The classification of these nodes is crucial in the management of the patient. Currently, only invasive measures obtaining tissue samples reach satisfying specificity. Contrast-enhanced endoscopic ultrasound (EUS) may offer a non-invasive alternative. A total of 122 patients (age: 63 +/- 15 years, 92 males, 30 females) with enlarged mediastinal and/or paraaortic lymph nodes diagnosed by CT scan were included in the study. EUS-guided fine needle aspiration was performed and cytologic specimens were diagnosed as representing a malignant or benign process in case of Papanicolau IV and V, or Papanicolau I and II, respectively. Based on cytology results, the investigated lymph nodes were classified as neoplastic (n = 48) or non-neoplastic lymph nodes. Using the B-mode criteria the preliminary diagnosis was confirmed in 64 out of 74 benign lymph nodes (specificity 86%). Regarding malignant lymph nodes 33 of 48 were confirmed (sensitivity 68%). Using the advanced contrast-enhanced EUS criteria the diagnosis was confirmed in 68 of 74 benign lymph nodes (specificity 91%). However, in case of malignant lymph nodes the number of correct diagnoses dropped to 29 of 48 lymph nodes (sensitivity 60%). The contrast-enhanced EUS criteria to identify benign lymph nodes and node enlargement in malignant lymphoma do not differ. If those ten patients with malignant lymphoma are excluded, the sensitivity of the contrast enhanced EUS for malignant lymph nodes rises to 73%. Contrast-enhanced EUS improves the specificity in diagnosing benign lymph nodes as compared to B-mode EUS. It does not improve the correct identification of malignant lymph nodes and cannot replace EUS-guided fine-needle aspiration.

  5. Preoperative detection and localization of accessory pudendal artery with contrast-enhanced MR angiography.

    Science.gov (United States)

    Whang, Shin Young; Sung, Deuk Jae; Lee, Seun Ah; Park, Beom Jin; Kim, Min Ju; Cho, Sung Bum; Kim, Yun Hwan; Cheon, Jun

    2012-03-01

    To evaluate the diagnostic performance of contrast material-enhanced magnetic resonance (MR) angiography for preoperative detection and localization of accessory pudendal arteries (APAs) in patients with prostate cancer. This prospective study was approved by the institutional review board, and informed consent was obtained. Between July 2007 and December 2010, 127 patients underwent contrast-enhanced MR angiography following prostate MR imaging at 3.0 T before robot-assisted laparoscopic radical prostatectomy (RALP). APAs were defined as any arteries located in the periprostatic region and anastomosed with the common penile artery or its branches; they were then subclassified into lateral and apical APAs. For detecting and localizing APAs, MR angiograms were evaluated prospectively by one reader and retrospectively by two independent blinded readers. Diagnostic performance was determined on a per-patient basis by using surgical findings as the reference standard. In addition, the origin of APAs identified at both surgery and contrast-enhanced MR angiography was determined by consensus of two retrospective readers. Interreader agreements were assessed by using k statistics. At surgery, 19 APAs (seven right apical, three left apical, four right lateral, and five left lateral) were detected in 16 patients, and 16 of these APAs were localized in 13 patients at preoperative contrast-enhanced MR angiography. Prospectively, sensitivity, specificity, and accuracy of contrast-enhanced MR angiography for the localization of APAs were 81.3%, 93.7%, and 92.1%, while retrospectively they were 87.5%, 91.9%, and 91.3% for reader 2 and 75.0%, 90.1%, and 88.2% for reader 3, respectively. Overall interreader agreement was substantial (k = 0.795). Nine and seven APAs originated from the obturator artery and the inferior vesical artery, respectively. Contrast-enhanced MR angiography can be used for the preoperative detection of APAs in patients with prostate cancer. © RSNA, 2012.

  6. Pelvic congestion syndrome initially detected by contrast enhanced F 18 FDG PET/CT

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Dae Weung; Kim, Myoung Hyoung; Kim, Woo Hyoung; Kim, Chang Guhn [Wonkwang Univ. School of Medicine, Iksan (Korea, Republic of)

    2012-03-15

    Pelvic congestion syndrome (PCS) is said to occur as a result of retrograde flow in an incompetent ovarian vein. Ovarian vein incompetence is seen in approximately 10% of women, and up to 60% with this abnormality can develop PCS. The etiology of PCS is poorly understood and is likely to be multifactorial. Absence of ovarian vein valves is an important factor in its development. The causes of ovarian varicoceles are multifactorial, involving both mechanical and hormonal factors. Dilatation of the ovarian veins can result in vascular incompetence and retrograde blood flow. On either CT or magnetic resonance (MR) imaging studies, pelvic varices in PCS appear as dilated, tortuous, enhancing tubular structures near the ovaries and uterus. In addition, the extension of varices to the broad ligament and paravaginal venous plexus can be appreciated. With CT, the tubular nature of these structures and the pattern of enhancement after intravenous contrast medium administration distinguish them from lymphadenopathy or adnexal masses. Unlike such masses, pelvic varices appear isodense with other veins after contrast enhancement. Contrast enhanced CT data as part of the combined PET/CT examination provide additional information when compared with non enhanced PET/CT. Because CT data supply the anatomic background for PET, the most important benefit relates to more precise anatomic localization of pathology by differentiation of the lesion from its surrounding structures. By supporting lesion detection and characterization, CT contrast agents can be of additional value in F 18 FDG non avid disease. As in the presented case, careful review of CT images in contrast enhanced PET/CT enables the detection of F 18 FDG non avid disease such as PCS. As contrast enhanced F 18 FDG PET/CT had been performed frequently, being familiar with the findings of PCS on the contrast enhanced CT images would have been helpful for the nuclear medicine physicians.

  7. Supraaortic arteries: contrast-enhanced MR angiography at 3.0 T--highly accelerated parallel acquisition for improved spatial resolution over an extended field of view.

    Science.gov (United States)

    Nael, Kambiz; Villablanca, J Pablo; Pope, Whitney B; McNamara, Thomas O; Laub, Gerhard; Finn, J Paul

    2007-02-01

    To prospectively use 3.0-T breath-hold high-spatial-resolution contrast material-enhanced magnetic resonance (MR) angiography with highly accelerated parallel acquisition to image the supraaortic arteries of patients suspected of having arterial occlusive disease. Institutional review board approval and written informed consent were obtained for this HIPAA-compliant study. Eighty patients (44 men, 36 women; age range, 44-90 years) underwent contrast-enhanced MR angiography of the head and neck at 3.0 T with an eight-channel neurovascular array coil. By applying a generalized autocalibrating partially parallel acquisition algorithm with an acceleration factor of four, high-spatial-resolution (0.7 x 0.7 x 0.9 mm = 0.44-mm(3) voxels) three-dimensional contrast-enhanced MR angiography was performed during a 20-second breath hold. Two neuroradiologists evaluated vascular image quality and arterial stenoses. Interobserver variability was tested with the kappa coefficient. Quantitation of stenosis at MR angiography was compared with that at digital subtraction angiography (DSA) (n = 13) and computed tomographic (CT) angiography (n = 12) with Spearman rank correlation coefficient (R(s)). Arterial stenoses were detected with contrast-enhanced MR angiography in 208 (reader 1) and 218 (reader 2) segments, with excellent interobserver agreement (kappa = 0.80). There was a significant correlation between contrast-enhanced MR angiography and CT angiography (R(s) = 0.95, reader 1; R(s) = 0.87, reader 2) and between contrast-enhanced MR angiography and DSA (R(s) = 0.94, reader 1; R(s) = 0.92, reader 2) for the degree of stenosis. Sensitivity and specificity of contrast-enhanced MR angiography for detection of arterial stenoses greater than 50% were 94% and 98% for reader 1 and 100% and 98% for reader 2, with DSA as the standard of reference. Vascular image quality was sufficient for diagnosis or excellent for 97% of arterial segments evaluated. By using highly accelerated parallel

  8. Simulation of the modulation transfer function dependent on the partial Fourier fraction in dynamic contrast enhancement magnetic resonance imaging.

    Science.gov (United States)

    Takatsu, Yasuo; Ueyama, Tsuyoshi; Miyati, Tosiaki; Yamamura, Kenichirou

    2016-12-01

    The image characteristics in dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) depend on the partial Fourier fraction and contrast medium concentration. These characteristics were assessed and the modulation transfer function (MTF) was calculated by computer simulation. A digital phantom was created from signal intensity data acquired at different contrast medium concentrations on a breast model. The frequency images [created by fast Fourier transform (FFT)] were divided into 512 parts and rearranged to form a new image. The inverse FFT of this image yielded the MTF. From the reference data, three linear models (low, medium, and high) and three exponential models (slow, medium, and rapid) of the signal intensity were created. Smaller partial Fourier fractions, and higher gradients in the linear models, corresponded to faster MTF decline. The MTF more gradually decreased in the exponential models than in the linear models. The MTF, which reflects the image characteristics in DCE-MRI, was more degraded as the partial Fourier fraction decreased.

  9. Evaluation of Dixon Sequence on Hybrid PET/MR Compared with Contrast-Enhanced PET/CT for PET-Positive Lesions

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Ju Hye; Cho, Ihn Ho; Kong, Eun Jung; Chun, Kyung Ah [Yeungnam Univ. Hospital, Daegu (Korea, Republic of)

    2014-03-15

    Hybrid positron emission tomography and magnetic resonance (PET/MR) imaging performs a two-point Dixon MR sequence for attenuation correction. However, MR data in hybrid PET/MR should provide anatomic and morphologic information as well as an attenuation map. We evaluated the Dixon sequence of hybrid PET/MR for anatomic correlation of PET-positive lesions compared with contrast-enhanced PET/computed tomography (CT) in patients with oncologic diseases. Twelve patients underwent a single injection, dual imaging protocol. PET/CT was performed with an intravenous contrast agent (85±13 min after {sup 18}F-FDG injection of 403± 45 MBq) and then (125±19 min after injection) PET/MR was performed. Attenuation correction and anatomic allocation of PET were performed using contrast-enhanced CT for PET/CT and Dixon MR sequence for hybrid PET/MR. The Dixon MR sequence and contrast-enhanced CT were compared for anatomic correlation of PET-positive lesions (scoring scale ranging from 0 to 3 for visual ratings). Additionally, standardized uptake values (SUVs) for the detected lesions were assessed for quantitative comparison. Both hybrid PET/MR and contrast-enhanced PET/CT identified 55 lesions with increased FDG uptake in ten patients. In total, 28 lymph nodes, 11 bone lesions, 3 dermal nodules, 3 pleural thickening lesions, 2 thyroid nodules, 1 pancreas, 1 liver, 1 ovary, 1 uterus, 1 breast, 1 soft tissue and 2 lung lesions were present. The best performance was observed for anatomic correlation of PET findings by the contrast-enhanced CT scans (contrast-enhanced CT, 2.64± 0.70; in-phase, 1.29±1.01; opposed-phase, 1.29±1.15; water-weighted, 1.71±1.07; fat weighted, 0.56±1.03). A significant difference was observed between the scores obtained from the contrast-enhanced CT and all four coregistered Dixon MR images. Quantitative evaluation revealed a high correlation between the SUVs measured with hybrid PET/MR (SUVmean, 2.63±1.62; SUVmax, 4.30±2.88) and contrast-enhanced

  10. Intravenous contrast-enhanced cone beam computed tomography (IVCBCT of intrahepatic tumors and vessels

    Directory of Open Access Journals (Sweden)

    Cynthia L. Eccles, BSc

    2016-01-01

    Conclusions: Intravenous-CBCT may enhance the visibility of hepatic vessels and tumor in CBCT scans obtained during breath hold. Optimization of IV contrast timing and reduction of artifacts to improve tumor visualization warrant further investigation.

  11. Clinical experiences of delayed contrast enhancement with cardiac computed tomography: case series

    Directory of Open Access Journals (Sweden)

    Sidhu Manavjot S

    2013-01-01

    Full Text Available Abstract Background Myocardial delayed enhancement (MDE by gadolinium-enhanced cardiac MRI is well established for myocardial scar assessment in ischemic and non-ischemic heart disease. The role of MDE by cardiac CT (CT-MDE is not yet defined. Findings We reviewed all clinical cases of CT-MDE at a tertiary referral center to present the cases as a case series. All clinical cardiac CT exams which utilized CT-MDE imaging between January 1, 2005 and October 1, 2010 were collected as a series and their findings were also compared with available myocardial imaging to assess for myocardial abnormalities, including echocardiography (wall motion, morphology, cardiac MRI (delayed enhancement, morphology, SPECT MPI (perfusion defects. 5,860 clinical cardiac CT exams were performed during the study period. CT-MDE was obtained in 18 patients and was reported to be present in 9 patients. The indications for CT-MDE included ischemic and non-ischemic heart diseases. In segments positive for CT-MDE, there was excellent agreement of CT with other modalities: echocardiography (n=8 demonstrated abnormal morphology and wall motion (k=1.0 and k=0.82 respectively; prior MRI (n=2 demonstrated abnormal delayed enhancement (MR-MDE (k=1.0; SPECT MPI (n=1 demonstrated fixed perfusion defects (k=1.0. In the subset of patients without CT-MDE, no abnormal segments were identified by echocardiography (n=8, MRI (n=1 and nuclear MPI (n=0. Conclusions CT-MDE was performed in rare clinical situations. The indications included both ischemic and non-ischemic heart disease and there was an excellent agreement between CT-MDE and abnormal myocardium by echocardiography, cardiac MRI, and nuclear MPI.

  12. Application of dynamic susceptibility contrast-enhanced perfusion in temporal lobe epilepsy

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    Xing, Wu; Wang, Xiaoyi; Xie, Fangfang; Liao, Weihua [Dept. of Radiology, Xiangya Hospital of Central South Univ., Changsha (China)], e-mail: doctoring@sina.com

    2013-02-15

    Background: Accurately locatithe epileptogenic focus in temporal lobe epilepsy (TLE) is important in clinical practice. Single-photon emission computed tomography (SPECT) and positron-emission tomography (PET) have been widely used in the lateralization of TLE, but both have limitations. Magnetic resonance perfusion imaging can accurately and reliably reflect differences in cerebral blood flow and volume. Purpose: To investigate the diagnostic value of dynamic susceptibility contrast-enhanced (DSC) perfusion magnetic resonance imaging (MRI) in the lateralization of the epileptogenic focus in TLE. Material and Methods: Conventional MRI and DSC-MRI scanning was performed in 20 interictal cases of TLE and 20 healthy volunteers. The relative cerebral blood volume (rCBV) and relative cerebral blood flow (rCBF) of the bilateral mesial temporal lobes of the TLE cases and healthy control groups were calculated. The differences in the perfusion asymmetry indices (AIs), derived from the rCBV and rCBF of the bilateral mesial temporal lobes, were pared between the two groups. Results: In the control group, there were no statistically significant differences between the left and right sides in terms of rCBV (left 1.55 {+-} 0.32, right 1.57 {+-} 0.28) or rCBF (left 99.00 {+-} 24.61, right 100.38 {+-} 23.46) of the bilateral mesial temporal lobes. However, in the case group the ipsilateral rCBV and rCBF values (1.75 {+-} 0.64 and 96.35 {+-} 22.63, respectively) were markedly lower than those of the contralateral side (2.01 {+-} 0.79 and 108.56 {+-} 26.92; P < 0.05). Both the AI of the rCBV (AIrCBV; 13.03 {+-} 10.33) and the AI of the rCBF (AIrCBF; 11.24 {+-} 8.70) of the case group were significantly higher than that of the control group (AIrCBV 5.55 {+-} 3.74, AIrCBF 5.12 {+-} 3.48; P < 0.05). The epileptogenic foci of nine patients were correctly lateralized using the 95th percentile of the AIrCBV and AIrCBF of the control group as the normal upper limits. Conclusion: In

  13. Effect of fatty liver background on contrast-enhanced ultrasonographic appearance of focal nodular hyperplasia

    Institute of Scientific and Technical Information of China (English)

    Li-Wu Lin; Jia-Jia Yang; Xue-Ying Lin; En-Sheng Xue; Yi-Mi He; Shang-Da Gao; Long Yang; Li-Yun Yu

    2007-01-01

    BACKGROUND:Focal nodular hyperplasia (FNH) is increasingly diagnosed as a result of the advances in imaging studies such as contrast-enhanced ultrasonography (CEUS), enhanced computed tomography and magnetic resonance imaging. However, FNH with atypical features can be dififcult to differentiate from other benign and malignant tumors. The aim of this study was to investigate the inlfuence of fatty liver background on the CEUS characteristics of FNH. METHODS:Twenty-six patients with FNH were divided into two groups: group A included 14 patients with fatty liver and group B included 12 patients with normal liver background. Conventional two-dimensional ultrasonography and color Doppler lfow imaging (CDFI) were conducted and followed by real-time dual-frame CEUS. RESULTS:On two-dimensional ultrasonography, hypo-echoic nodules were present in most of the patients in group A (12/14) and hyperechoic nodules in most of those in group B (7/12). The difference in the nodule echotextures between the two groups was statistically signiifcant (P0.05). On CEUS, nodules with a central spoked-wheel-like enhancement pattern in the early arterial phase were observed in 8 patients in group A and those with an eccentric enhancement pattern in the remaining 6 patients. In this group, 3 patients had hypoechoic nodules in the delayed phase. Eleven of the 14 patients in this group were diagnosed accurately with CEUS. In group B, nodules with a rapid central spoked-wheel-like enhancement pattern in the early arterial phase were found in 8 patients by CEUS and those with rapid an eccentric enhancement pattern in 4. The nodules were found to be continuously enhanced in the delayed phase. All of the patients in group B were accurately diagnosed with CEUS. CONCLUSIONS:A FNH nodule on a background of fatty liver may present a hypoechoic pattern on two-dimensional ultrasonography and a hypoechoic wash-out pattern in the delayed phase on CEUS. At this time, punch biopsy is needed for the

  14. Breast Lesions: Correlation of Dynamic Contrast Enhancement Patterns on MR images with Tumor Angiogenesis

    Institute of Scientific and Technical Information of China (English)

    PeifangLiu; RunxianBao; YunNiu; YongYu

    2004-01-01

    OBJECTIVE To determine whether dynamic contrast-enhanced MRI features of the early -phase enhancement rate, enhancement amplitude, and signal-intensity (SI) time course are associated with the microvessel density (MVD) and vascular endothelial growth factor (VEGF) expression of malignant and benign breast lesions. METHODS Sixty patients with breast lesions, detected with physical examination or conventional mammography, were examined pre-operatively with dynamic contrast-enhanced MRI from December 1998 to June 2000. Of these 60 patients, histopathological correlation was available in 38. These 38 patients(aged 29-73 years) formed the basis of this study. SI changes during dynamic scanning were assessed quantitatively. Early-phase enhancement rate and enhancement amplitude were calculated. Time-Sl curves of the lesions were obtained and classified according to their shapes as type I (which was steady enhancement to the end of the dynamic data acquisition at 7.5rain.), type Ⅱ (plateau of SI after avid initial contrast enhancement), or type Ⅲ (washout of SI after avid initial contrast enhancement). The mean MVD and VEGF expression of the lesions were measured with immunohistochemical staining methods in all the pathologic specimens by a pathologist without knowledge of the results of the MR examination. Care was taken to ensure identical location in the plane of the MR image and pathologic specimens. The relationships among dynamic contrast-enhanced MRI features, MVD, and VEGF expression of benign and malignant breast lesions were analyzed. RESULTS Histology revealed 21 malignancies and 17 benign lesions. The mean MVD and VEGF expression for the 21 malignant lesions were significantly higher than the mean MVD and VEGF expression for the 17 benign lesions (P60%) MR early-phase enhancement rate and time-SI curve type Ⅱ or Ⅲ showed a significant association with MVD and VEGF expression. All the differences mentioned above showed statistical significance (P 0

  15. Dynamic Contrast-Enhanced Magnetic Resonance Enterography and Dynamic Contrast-Enhanced Ultrasonography in Crohn’s Disease: An Observational Comparison Study

    Science.gov (United States)

    Wilkens, Rune; Peters, David A.; Nielsen, Agnete H.; Hovgaard, Valeriya P.; Glerup, Henning; Krogh, Klaus

    2017-01-01

    Purpose e Cross-sectional imaging methods are important for objective evaluationof small intestinal inflammationinCrohn’sdisease(CD).The primary aim was to compare relative parameters of intestinal perfusion between contrast-enhanced ultrasonography (CEUS) and dynamic contrast-enhanced magnetic resonance enterography (DCE-MRE) in CD. Furthermore, we aimed at testing the repeatability of regions of interest (ROIs) for CEUS. Methods This prospective study included 25 patients: 12 females (age: 37, range: 19–66) with moderate to severe CD and a bowel wall thickness>3mm evaluated with DCE-MRE and CEUS. CEUS bolus injection was performed twice for repeatability and analyzed in VueBox®. Correlations between modalities were described with Spearman’s rho, limits of agreement(LoA) and intraclass correlation coefficient(ICC). ROIrepeatability for CEUS was assessed. Results s The correlation between modalities was good and very good for bowel wall thickness (ICC=0.71, P<0.001) and length of the inflamed segment (ICC=0.89, P<0.001). Moderate-weak correlations were found for the time-intensity curve parameters: peak intensity (r=0.59, P=0.006), maximum wash-in-rate (r=0.62, P=0.004), and wash-in perfusion index (r=0.47, P=0.036). Best CEUS repeatability for peak enhancement was a mean difference of 0.73 dB (95% CI: 0.17 to 1.28, P=0.01) and 95% LoA from −3.8 to 5.3 dB. Good quality of curve fit improved LoA to −2.3 to 2.8 dB. Conclusion The relative perfusion of small intestinal CD assessed with DCE-MRE and CEUS shows only a moderate correlation. Applying strict criteria for ROIs is important and allows for good CEUS repeatability PMID:28286879

  16. Efficiency of Contrast-Enhanced Fat-Suppressed Proton Density Images for Shoulder MRI: Comparison with Contrast-enhanced Fat-suppressed T1 Weighted Image and Arthroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Kwan Sub; Ha, Doo Hoe; Lee, Sang Min; Yoo, Ko Eun; Kim, Jae Wha [Bundang CHA General Hospital, Pocheon (Korea, Republic of)

    2009-03-15

    This study was designed to evaluate the efficiency of contrast-enhanced fat-suppressed proton-density images (CE-FS-PDI) for shoulder MRI. We retrospectively reviewed 54 shoulder MR precontrast fat-suppressed proton-density images (FS-PDI), CE-FS-PDI and contrast-enhanced fat-suppressed T1 weighted images (CE-FS-T1WI). Signal-to-noise ratios (SNRs) and contrast-to-noise ratios (CNRs) of the posterior labrum, infraspinatus muscle, synovium, biceps brachii long head tendon and subcutaneous fat were analyzed on each sequence. Subsequently, 53 cases were reviewed where patients had undergone both shoulder arthroscopy and shoulder MRI. We analyzed the diagnostic agreement rates between the CE-FS-PDI and CE-FS-T1WI and the diagnostic accuracy of arthroscopically proven tears of the supraspinatus tendon. On CE-FS-PDI, the SNRs and CNRs of all structures were statistically higher than on precontrast FSPDI and CE-FS-T1WI. Diagnostic agreement rates between CE-FS-PDI and CE-FS-T1WI were 70-96% in labrums and 75-96% in rotator cuffs. The diagnostic accuracy rates for a tear of the supraspinatus tendon were 83% on CE-FS-PDI and 75% on CE-FS-T1WI, respectively. The SNR and CNR on CE-FS-PDI were increased in the shoulder structures, and the diagnostic rate for a tear of the supraspinatus tendon on CE-FS-PDI was superior as compared to CE-FS-T1WI. Therefore, CE-FS-PDI will be useful for shoulder MRI.

  17. High-resolution 3D non-contrast-enhanced, ECG-gated, multi-step MR angiography of the lower extremities: Comparison with contrast-enhanced MR angiography

    Energy Technology Data Exchange (ETDEWEB)

    Mohrs, Oliver K. [University of Heidelberg, Department of Diagnostic and Interventional Radiology, Heidelberg (Germany); Darmstadt Radiology, Department of Cardiovascular Imaging at Alice-Hospital, Darmstadt (Germany); Petersen, Steffen E. [The London Chest Hospital, Centre for Advanced Cardiovascular Imaging, William Harvey Research Institute, Barts and The London NIHR Biomedical Research Unit, London (United Kingdom); Heidt, Martin C. [Cardiovascular Center Darmstadt, Darmstadt (Germany); Schulze, Thomas; Schmitt, Peter [Siemens AG, Healthcare Sector, MR Application and Workflow Development, Erlangen (Germany); Bergemann, Sabine [Darmstadt Radiology, Department of Cardiovascular Imaging at Alice-Hospital, Darmstadt (Germany); Kauczor, Hans-Ulrich [University of Heidelberg, Department of Diagnostic and Interventional Radiology, Heidelberg (Germany)

    2011-02-15

    To determine the diagnostic value of non-contrast-enhanced, 3D-high-resolution, ECG-gated, multi-step MR angiography (non-ceMRA) of the lower extremities using a modified turbo-spin-echo technique in comparison to 1.0-molar contrast-enhanced MR angiography (ceMRA) in patients with suspected peripheral vascular disease (PVD). Fifty consecutive patients underwent non-ceMRA before ceMRA within the same session. We assessed examination time, image quality, localisation and severity of stenosis. Examination time was shorter for ceMRA (12 {+-} 4 min) compared with non-ceMRA (28 {+-} 6 min, p < 0.001). The image quality of the aorta-iliac, femoral and combined popliteal and lower leg arteries was inferior for non-ceMRA (2.8 {+-} 0.8/3.3 {+-} 0.8/3.3 {+-} 0.9) versus ceMRA (4.7 {+-} 0.8/4.8 {+-} 0.6/4.8 {+-} 0.7) on a 5-point scale with 5 for maximum quality (p < 0.01). CeMRA offered more assessable data sets than non-ceMRA (98% vs. 90%). For detecting stenosis >50% or occlusions of pelvic and femoral arteries using non-ceMRA the sensitivity, specificity, positive and negative predictive values were 94%, 86%, 67% and 98% and for popliteal and lower leg arteries 93%, 87%, 69% and 98%, respectively. We demonstrated that 3D non-ceMRA represents a very promising technique in patients with lower extremities PVD and could be used as an alternative if gadolinium-based contrast agents cannot be administered. (orig.)

  18. MR imaging of pulmonary embolism: diagnostic accuracy of contrast-enhanced 3D MR pulmonary angiography, contrast-enhanced low-flip angle 3D GRE, and nonenhanced free-induction FISP sequences.

    Science.gov (United States)

    Kalb, Bobby; Sharma, Puneet; Tigges, Stefan; Ray, Gaye L; Kitajima, Hiroumi D; Costello, James R; Chen, Zhengjia; Martin, Diego R

    2012-04-01

    To evaluate relative detection of pulmonary embolism (PE) with standard bolus-triggered contrast-enhanced breath-hold magnetic resonance (MR) pulmonary angiography, contrast-enhanced recirculation-phase breath-hold low-flip angle three-dimensional (3D) gradient-echo (GRE), and nonenhanced free-induction cardiac- and respiratory-triggered true fast imaging with steady-state precession (FISP) MR sequences. The study was HIPAA compliant and institutional review board approved. Twenty-two patients with a computed tomographic (CT) angiography diagnosis of PE underwent MR imaging within 48 hours of CT. MR included three complementary techniques: MR pulmonary angiography, 3D GRE, and triggered true FISP. Each sequence was analyzed separately by two independent reviewers who recorded presence of emboli in categorized pulmonary artery anatomic territories. CT angiography results were analyzed by a third independent reviewer, who retrospectively recorded presence of emboli using the same format; these results served as the reference standard. Sensitivity, specificity, and positive and negative predictive values for PE detection were calculated for each MR technique on a per-embolus basis, and 95% confidence intervals were calculated according to the efficient-score method. A two-sample t test was used to compare values among MR techniques. Sensitivities for PE detection were 55% for MR pulmonary angiography, 67% for triggered true FISP, and 73% for 3D GRE MR imaging. Combining all three MR sequences improved overall sensitivity to 84%. Specificity was 100% for all detection methods except for MR pulmonary angiography (one false-positive). Agreement between readers was high (κ = 0.87). Embolus detection rates were lowest in the lingula branch for all MR sequences compared with remainder of the vascular territories (P = .07). There are complementary benefits to combining standard MR pulmonary angiography, 3D GRE, and triggered true FISP MR examinations for evaluation of PE.

  19. An Improved Local Equilibrium Contrast Enhancement Algorithm for Infrared Laser Images

    Directory of Open Access Journals (Sweden)

    Yuhong Li

    2010-12-01

    Full Text Available An improved local equilibrium contrast enhancement algorithm based self-adaptive contrast enhancement algorithm is proposed for infrared laser images, in which the image pixel value histogram is divided into three parts: background and noise area, targets area, and uninterested area. The targets parts are highlighted, while the background and noise parts and the uninterested parts are restrained. A comprehensive qualitative and quantitative image enhancement performance evaluation is presented to verify the proposed theory and algorithm validity, efficiency and reasonability. The experimental results indicate that the proposed algorithm can greatly improve the global and local contrast for both near infrared images and far infrared laser images while efficiently reducing noise in the infrared laser images,and the visual quality of enhanced image is obviously better than the enhancement of the traditional histogram equalization, double plateaus histogram equalization algorithm, etc.

  20. Contrast-enhanced MRI of the small bowel in Crohn's disease.

    Science.gov (United States)

    Oommen, Jacob; Oto, Aytekin

    2011-04-01

    Recently, magnetic resonance imaging has emerged as a valuable tool in evaluation of small bowel Crohn's disease. MRI provides several advantages to other imaging modalities, including the lack of ionizing radiation, multiplanar capability, and functional information. Intravenous contrast administration is a routine portion of MR enterography protocol, and aids in detection of disease extent, extramural complications such as fistula and abscess, and assessment of activity. Additionally, promising techniques such as dynamic contrast-enhanced MRI may provide quantitative measures to assess bowel perfusion, which may enhance evaluation of disease activity. This article will provide an overview of the technical aspects of contrast-enhanced MR enterography, describe common pathologic findings involving the small bowel in Crohn's disease, summarize its role in determination of activity with an emphasis on endoscopic and histologic correlation, and compare its efficacy with other imaging modalities.

  1. LHRH-functionalized superparamagnetic iron oxide nanoparticles for breast cancer targeting and contrast enhancement in MRI

    Energy Technology Data Exchange (ETDEWEB)

    Meng, J.; Fan, J. [Princeton Institute of Science and Technology of Materials and the Department of Mechanical and Aerospace Engineering, Princeton University, Princeton, NJ 08544 (United States); Galiana, G. [Department of Chemistry, Princeton University, Princeton, NJ 08544 (United States); Branca, R.T. [Department of Chemistry, Duke University, Durham, NC 27708-0354 (United States); Clasen, P.L.; Ma, S. [Center for Advanced Materials and Nanotechnology, Lehigh University, Bethlehem, PA 18015-3195 (United States); Zhou, J. [Princeton Institute of Science and Technology of Materials and the Department of Mechanical and Aerospace Engineering, Princeton University, Princeton, NJ 08544 (United States); Leuschner, C. [Pennington Biomedical Research Center, 6400 Perkins Road, Baton Rouge, LA 70808 (United States); Kumar, C.S.S.R.; Hormes, J. [Center for Advanced Microstructures and Devices, Louisiana State University, 6980 Jefferson Hwy, Baton Rouge, LA 70806 (United States); Otiti, T. [Department of Physics, Makerere University, Kampala (Uganda); Beye, A.C. [Department of Physics, Cheikh Anta Diop University, Dakar (Senegal); Harmer, M.P.; Kiely, C.J. [Center for Advanced Materials and Nanotechnology, Lehigh University, Bethlehem, PA 18015-3195 (United States); Warren, W. [Department of Chemistry, Duke University, Durham, NC 27708-0354 (United States); Haataja, M.P. [Princeton Institute of Science and Technology of Materials and the Department of Mechanical and Aerospace Engineering, Princeton University, Princeton, NJ 08544 (United States); Soboyejo, W.O., E-mail: soboyejo@princeton.edu [Princeton Institute of Science and Technology of Materials and the Department of Mechanical and Aerospace Engineering, Princeton University, Princeton, NJ 08544 (United States)

    2009-05-05

    This paper shows that superparamagnetic iron oxide nanoparticles (SPIONs) conjugated to luteinizing hormone releasing hormone (LHRH) (LHRH-SPIONs), can be used to target breast cancer cells. They also act as contrast enhancement agents during the magnetic resonance imaging of breast cancer xenografts. A combination of transmission electron microscopy (TEM) and spectrophotometric analysis was used in our experiments, to investigate the specific accumulation of the functionalized superparamagnetic iron oxide nanoparticles (SPIONs) in cancer cells. The contrast enhancement of conventional T2 images obtained from the tumor tissue and of breast cancer xenograft bearing mice is shown to be much greater than that in saline controls, when the tissues were injected with LHRH-SPIONs. Magnetic anisotropy multi-CRAZED images of tissues extracted from mice injected with SPIONs were also found to have enhanced MRI contrast in breast cancer xenografts and metastases in the lungs.

  2. Gadolinium-free MR in coarctation-can contrast-enhanced MR angiography be replaced?

    Science.gov (United States)

    Kalmar, Peter I; Koestenberger, Martin; Marterer, Robert; Tschauner, Sebastian; Sorantin, Erich

    2016-01-01

    To determine the difference in vessel measurements, signal-to-noise ratio (SNR), and voxel size between contrast-enhanced and noncontrast magnetic resonance techniques in patients with coarctation of the aorta (CoA). In 39 patients, vessel size, SNR, and voxel size were compared in cine magnetic resonance imaging (MRI), gadolinium-free magnetic resonance angiography (Gd-free MRA), and contrast-enhanced MRA (ce-MRA). There was no significant difference in measurement and SNR, but there was a significant difference in voxel size (P<.001). Our results show that, in CoA patients, monitoring of vessel size using cine MRI and Gd-free MRA is equivalent to ce-MRA while being less invasive. Copyright © 2016 Elsevier Inc. All rights reserved.

  3. Optimum wavelet based masking for the contrast enhancement of medical images using enhanced cuckoo search algorithm.

    Science.gov (United States)

    Daniel, Ebenezer; Anitha, J

    2016-04-01

    Unsharp masking techniques are a prominent approach in contrast enhancement. Generalized masking formulation has static scale value selection, which limits the gain of contrast. In this paper, we propose an Optimum Wavelet Based Masking (OWBM) using Enhanced Cuckoo Search Algorithm (ECSA) for the contrast improvement of medical images. The ECSA can automatically adjust the ratio of nest rebuilding, using genetic operators such as adaptive crossover and mutation. First, the proposed contrast enhancement approach is validated quantitatively using Brain Web and MIAS database images. Later, the conventional nest rebuilding of cuckoo search optimization is modified using Adaptive Rebuilding of Worst Nests (ARWN). Experimental results are analyzed using various performance matrices, and our OWBM shows improved results as compared with other reported literature.

  4. CW-THz image contrast enhancement using wavelet transform and Retinex

    Science.gov (United States)

    Chen, Lin; Zhang, Min; Hu, Qi-fan; Huang, Ying-Xue; Liang, Hua-Wei

    2015-10-01

    To enhance continuous wave terahertz (CW-THz) scanning images contrast and denoising, a method based on wavelet transform and Retinex theory was proposed. In this paper, the factors affecting the quality of CW-THz images were analysed. Second, an approach of combination of the discrete wavelet transform (DWT) and a designed nonlinear function in wavelet domain for the purpose of contrast enhancing was applied. Then, we combine the Retinex algorithm for further contrast enhancement. To evaluate the effectiveness of the proposed method in qualitative and quantitative, it was compared with the adaptive histogram equalization method, the homomorphic filtering method and the SSR(Single-Scale-Retinex) method. Experimental results demonstrated that the presented algorithm can effectively enhance the contrast of CW-THZ image and obtain better visual effect.

  5. Virtual restoration of ancient Chinese paintings using color contrast enhancement and lacuna texture synthesis.

    Science.gov (United States)

    Pei, Soo-Chang; Zeng, Yi-Chong; Chang, Ching-Hua

    2004-03-01

    This work presents a novel algorithm using color contrast enhancement and lacuna texture synthesis is proposed for the virtual restoration of ancient Chinese paintings. Color contrast enhancement based on saturation and de-saturation is performed in the u'v'Y color space, to change the saturation value in the chromaticity diagram, and adaptive histogram equalization then is adopted to adjust the luminance component. Additionally, this work presents a new patching method using the Markov Random Field (MRF) model of texture synthesis. Eliminating undesirable aged painting patterns, such as stains, crevices, and artifacts, and then filling the lacuna regions with the appropriate textures is simple and efficient. The synthesization procedure integrates three key approaches, weighted mask, annular scan and auxiliary, with neighborhood searching. These approaches can maintain a complete shape and prevent edge disconnection in the final results. Moreover, the boundary between original and synthesized paintings is seamless, and unable to distinguish in which the undesirable pattern appears.

  6. A novel simultaneous dynamic range compression and local contrast enhancement algorithm for digital video cameras

    Directory of Open Access Journals (Sweden)

    Tsai Chi-Yi

    2011-01-01

    Full Text Available Abstract This article addresses the problem of low dynamic range image enhancement for commercial digital cameras. A novel simultaneous dynamic range compression and local contrast enhancement algorithm (SDRCLCE is presented to resolve this problem in a single-stage procedure. The proposed SDRCLCE algorithm is able to combine with many existent intensity transfer functions, which greatly increases the applicability of the proposed method. An adaptive intensity transfer function is also proposed to combine with SDRCLCE algorithm that provides the capability to adjustably control the level of overall lightness and contrast achieved at the enhanced output. Moreover, the proposed method is amenable to parallel processing implementation that allows us to improve the processing speed of SDRCLCE algorithm. Experimental results show that the performance of the proposed method outperforms three state-of-the-art methods in terms of dynamic range compression and local contrast enhancement.

  7. Power constrained contrast enhancement based on brightness compensated contrast-tone mapping operation

    Science.gov (United States)

    Jung, Cheolkon; Su, Haonan; Wang, Lu; Ke, Peng

    2016-09-01

    We propose power constrained contrast enhancement based on brightness compensated contrast-tone mapping operation (BCCTMO). We adopt brightness compensation to restore the original perceptual luminance and combine tone mapping with contrast enhancement to improve image quality. First, we increase pixel values to compensate for the reduced brightness caused by backlight dimming while maintaining the perceived luminance. Then we perform a contrast-tone mapping operation to reduce the information loss caused by the brightness compensation and enhance contrast in images. Finally, we conduct color scaling to reproduce natural colors. We implement BCCTMO on an Android tablet with an LCD display using mathematical approximation. Experimental results demonstrate that BCCTMO produces high-quality images while minimizing distortions and saving power compared with state-of-the-art methods.

  8. Contrast-enhanced MR angiography of abdominal vessels: Is there still a role for angiography?

    Energy Technology Data Exchange (ETDEWEB)

    Vosshenrich, R.; Fischer, U. [Department of Radiology, Georg-August-Universitaet Goettingen (Germany)

    2002-01-01

    The purpose of this review article is to describe recent advantages in contrast-enhanced (CE) three-dimensional (3D) magnetic resonance angiography (MRA) in comparison with other vascular imaging techniques, and to discuss their current clinical applications for the imaging of abdominal vessels. Principles and technical considerations are presented and clinical applications are reviewed for different vascular diseases. In ruptured aortic aneurysms and acute dissections CT is the method of first choice. Contrast-enhanced 3D MRA can be well used for therapeutic planning and follow-up in patients with stable disease. A comprehensive MR examination including CE 3D MRA, MR urography and MR nephrogram has the potential to replace the conventional studies for the evaluation of renal vascular disease. It is an accurate method for imaging the origins of coeliac and superior mesenteric arteries, although the image resolution is too low for reliable assessment of the inferior mesenteric artery. Contrast-enhanced 3D MRA has emerged as the method of choice for studying the portal venous system in liver transplant recipients, in patients with portal hypertension and in cases with abdominal tumours for preoperative evaluation. Additional non-invasive flow measurements are useful in monitoring portal hypertension. The abdominal veins can be well imaged using unenhanced MR techniques. Imaging may be facilitated with intravascular contrast media. Contrast-enhanced 3D MRA can replace intra-arterial DSA for diagnosis, therapy planning and follow-up in patients with abdominal vascular disease. Catheter-based arteriography will still be used for interventional procedures such as percutaneous transluminal angioplasty, stent placement and embolisation. (orig.)

  9. Protoneus-sequence: extended fluid-attenuated inversion recovery MR imaging without and with contrast enhancement

    Energy Technology Data Exchange (ETDEWEB)

    Nasel, Christian [Division of Neuroradiology, Department of Radiology, Medical University of Vienna, Waehringerguertel 18-20, A-1090 Vienna (Austria)]. E-mail: christian.nasel@perfusion.at

    2005-08-01

    Fluid-attenuated inversion recovery imaging (=flair imaging) is widely used as primary screening sequence in various investigation protocols, due to its high lesion contrast and sensitivity in detection of parenchymatous and leptomeningeal disease. An additional increase of sensitivity for detection of lesions may be achieved by contrast-enhanced flair imaging. Based on flair imaging a dual-echo inversion recovery imaging sequence (=proton echo usage [=protoneus] - sequence) was developed, which could significantly extend the possibilities of conventional flair imaging.

  10. Soft-Tissue Tumor Contrast Enhancement Patterns: Diagnostic Value and Comparison Between Ultrasound and MRI.

    Science.gov (United States)

    Gruber, Leonhard; Loizides, Alexander; Luger, Anna K; Glodny, Bernhard; Moser, Patrizia; Henninger, Benjamin; Gruber, Hannes

    2017-02-01

    The purpose of this study was to assess and compare contrast-enhanced ultrasound and MRI patterns in the diagnosis of soft-tissue masses. Two hundred fifty-five consecutively registered patients with histologically confirmed soft-tissue masses were included in this retrospective study. The diagnostic properties of four predefined contrast enhancement (CE) patterns were assessed, and logistic regression analysis was performed to determine the correlation between diagnosis and CE pattern, lesion size, and patient age and sex. The influence of lesion size on the occurrence of inhomogeneous CE patterns in malignancies was also determined. Homogeneous CE patterns were highly specific for benignity, and inhomogeneous CE was moderately specific for malignancy in both ultrasound and MRI. A combination of homogeneous and inhomogeneous CE patterns led to 88.3% and 88.7% sensitivity, 66.7% and 59.7% specificity, 73.4% and 68.2% correct classification, 54.6% and 47.8% positive predictive value, 92.6% and 92.7% negative predictive value, 2.65 and 2.20 positive likelihood ratio, and 0.18 and 0.19 negative likelihood ratio for contrast-enhanced ultrasound and contrast-enhanced MRI. Cases with homogeneous CE in either ultrasound or MRI also were predominantly benign. The occurrence of inhomogeneous CE in malignant lesions increased with size. CE patterns in ultrasound and MRI offer additional information about the differentiation of an unknown soft-tissue mass. The results of this study showed that homogeneous or absent CE was specific for benign differentiation and that heterogeneous CE was linked to malignancy. The routine analysis of CE patterns should increase diagnostic reliability in unclear soft-tissue masses.

  11. Improvement of Fuzzy Image Contrast Enhancement Using Simulated Ergodic Fuzzy Markov Chains

    Directory of Open Access Journals (Sweden)

    Behrouz Fathi-Vajargah

    2014-01-01

    Full Text Available This paper presents a novel fuzzy enhancement technique using simulated ergodic fuzzy Markov chains for low contrast brain magnetic resonance imaging (MRI. The fuzzy image contrast enhancement is proposed by weighted fuzzy expected value. The membership values are then modified to enhance the image using ergodic fuzzy Markov chains. The qualitative performance of the proposed method is compared to another method in which ergodic fuzzy Markov chains are not considered. The proposed method produces better quality image.

  12. Recurrent Pulmonary Capillary Hemangioma: Dynamic Contrast-Enhanced CT and Histopathologic Findings

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Eun Young; Kim, Tae Sung; Han, Joung Ho; Choi, Yong Soo [Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of); Kim, Ho Joong [Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of)

    2012-06-15

    We report the dynamic contrast-enhanced CT and histopathologic findings of a rare case of recurrent pulmonary capillary hemangiomas. The findings consisted of peripheral nodular enhancement at the early arterial phase and a subsequent 'central filling-in' enhancement pattern on the delayed scans, which was identical to the well-known enhancement pattern of hemangiomas of the liver. Although there was no evidence of histological malignancy, pulmonary capillary hemangiomas manifested as multiple nodular lesions and showed postoperative recurrence.

  13. Gadolinium Contrast Enhancement Improves Confidence in Diagnosing Recurrent Soft Tissue Sarcoma by MRI.

    Science.gov (United States)

    Chou, Shinn-Huey S; Hippe, Daniel S; Lee, Amie Y; Scherer, Kurt; Porrino, Jack A; Davidson, Darin J; Chew, Felix S; Ha, Alice S

    2017-05-01

    To determine how utilization of postgadolinium magnetic resonance imaging (MRI) influenced reader accuracy and confidence at identifying postoperative soft tissue sarcoma (STS) recurrence among readers with various levels of expertise. This retrospective study was institutional review board approved and Health Insurance Portability and Accountability Act compliant. Postoperative MRI from 26 patients with prior STS resection (13 patients with confirmed recurrence, 13 without recurrence) was reviewed. Four blinded readers of varying expertise (radiology resident, fellow, attending, and orthopedic oncologist) initially evaluated only the precontrast images and rated each MRI for recurrence on a 5-point confidence scale. Assessment was repeated with the addition of contrast-enhanced sequences. Diagnostic accuracy based on confidence ratings was evaluated using the area under the receiver operating characteristic curve (AUC). Changes in confidence ratings were calculated using Wilcoxon signed-rank test. All readers demonstrated good diagnostic accuracy both with and without contrast-enhanced images (AUC >0.98 for each reader). When contrast-enhanced images were made available, the resident recorded improved confidence with both assigning (P = 0.031) and excluding recurrence (P = 0.006); the fellow showed improved confidence only with assigning recurrence (P = 0.015); and the surgeon showed improved confidence in excluding recurrence (P = 0.003). The addition of contrast-enhanced images did not significantly influence the diagnostic confidence of the attending radiologist. Diagnostic accuracy of MRI was excellent in evaluating postoperative STS recurrence, and reader confidence improved depending on expertise when postgadolinium imaging was included in the assessment. Copyright © 2017 The Association of University Radiologists. Published by Elsevier Inc. All rights reserved.

  14. Contrast-enhanced ultra-high-field liver MRI: A feasibility trial

    Energy Technology Data Exchange (ETDEWEB)

    Umutlu, Lale, E-mail: Lale.Umutlu@uk-essen.de [Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen (Germany); Erwin L. Hahn Institute for Magnetic Resonance Imaging, Essen (Germany); Bitz, Andreas K.; Maderwald, Stefan; Orzada, Stephan; Kinner, Sonja; Kraff, Oliver; Brote, Irina; Ladd, Susanne C.; Schroeder, Tobias; Forsting, Michael; Antoch, Gerald; Ladd, Mark E. [Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen (Germany); Erwin L. Hahn Institute for Magnetic Resonance Imaging, Essen (Germany); Quick, Harald H. [Erwin L. Hahn Institute for Magnetic Resonance Imaging, Essen (Germany); Institute of Medical Physics, University Nuernberg-Erlangen (Germany); Lauenstein, Thomas C. [Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen (Germany); Erwin L. Hahn Institute for Magnetic Resonance Imaging, Essen (Germany)

    2013-05-15

    The aim of this study was to investigate the feasibility of dynamic contrast-enhanced 7 T MRI of the liver using an eight-channel radiofrequency (RF) transmit/receive body-coil. 16 healthy subjects were examined on a 7 T MR system utilizing a custom-built eight-channel RF body-coil suitable for RF-shimming. The following data were acquired: (1) steady state free precession imaging, (2) T2w turbo spin echo imaging, (3) T1w in and opposed-phase imaging, (4) T1w 3D FLASH images pre-contrast and in arterial, portal-venous and venous phase and (5) a fat-saturated pre- and post-contrast 2D FLASH sequence. Visual evaluation of (1) the delineation of liver vasculature, (2) the overall image quality, and (3) artifact presence and consequent image impairment was performed. SNR of the liver parenchyma was measured for the contrast-enhanced 2D and 3D FLASH sequences. For statistical analysis, a Wilcoxon-Rank Test was used. Best delineation of non-enhanced liver vasculature and overall image quality was found for 2D FLASH MRI, with only slight improvement in vessel conspicuity after the application of contrast media. T2-weighted TSE imaging remained strongly impaired, falling short of diagnostic relevance and precluding a clinical application. Our results demonstrate the feasibility and diagnostic potential of dedicated contrast-enhanced 7 T liver MRI as well as the potential for non-contrast-enhanced angiographic application.

  15. Contrast-Enhanced Abdominal MRI for Suspected Appendicitis: How We Do It

    Science.gov (United States)

    Kinner, Sonja; Repplinger, Michael D.; Pickhardt, Perry J.; Reeder, Scott B.

    2017-01-01

    OBJECTIVE The purpose of this article is to describe our approach to contrast-enhanced abdominal MRI in patients with nontraumatic abdominal pain and suspected appendicitis. We aim to share our experience on the advantages, pearls, and pitfalls of MRI in this clinical setting, in comparison with CT and ultrasound. CONCLUSION We present some typical cases of appendicitis and alternative diagnoses in patients presenting with acute nontraumatic abdominal pain. PMID:27065072

  16. Contrast-enhanced MRI of intrasellar arachnoid cysts: relationship between the pituitary gland and cyst

    Energy Technology Data Exchange (ETDEWEB)

    Nomura, M. [National Cardiovascular Center, Osaka (Japan). Dept. of Neurosurgery]|[Kanazawa Univ. School of Medicine (Japan). Dept. of Neurosurgery; Tachibana, O. [Kanazawa Univ. School of Medicine (Japan). Dept. of Neurosurgery; Hasegawa, M. [Kanazawa Univ. School of Medicine (Japan). Dept. of Neurosurgery; Kohda, Y. [Kanazawa Univ. School of Medicine (Japan). Dept. of Neurosurgery; Nakada, M. [Kanazawa Univ. School of Medicine (Japan). Dept. of Neurosurgery; Yamashima, T. [Kanazawa Univ. School of Medicine (Japan). Dept. of Neurosurgery; Yamashita, J. [Kanazawa Univ. School of Medicine (Japan). Dept. of Neurosurgery; Suzuki, M. [Kanazawa Univ. School of Medicine (Japan). Dept. of Radiology

    1996-08-01

    We recently encountered two large intrasellar arachnoid cysts extending to the suprasellar region. The intensity of the cyst contents was identical to that of the cerebrospinal fluid on both T1- and T2-weighted MRI. On contrast-enhanced MRI, the pituitary gland was compressed posteroinferiorly and flattened in the sella turcica. In this report of rare intrasellar arachnoid cysts the discussion is focused on dislocation of the pituitary gland. (orig.)

  17. Fusion of contrast-enhanced breast MR and mammographic imaging data.

    Science.gov (United States)

    Behrenbruch, Christian P; Marias, Kostas; Armitage, Paul A; Yam, Margaret; Moore, Niall; English, Ruth E; Clarke, Jane; Brady, Michael

    2003-09-01

    Increasing use is being made of Gd-DTPA contrast-enhanced magnetic resonance imaging for breast cancer assessment since it provides 3D functional information via pharmacokinetic interaction between contrast agent and tumour vascularity, and because it is applicable to women of all ages as well as patients with post-operative scarring. Contrast-enhanced MRI (CE-MRI) is complementary to conventional X-ray mammography, since it is a relatively low-resolution functional counterpart of a comparatively high-resolution 2D structural representation. However, despite the additional information provided by MRI, mammography is still an extremely important diagnostic imaging modality, particularly for several common conditions such as ductal carcinoma in situ (DCIS) where it has been shown that there is a strong correlation between microcalcification clusters and malignancy. Pathological indicators such as calcifications and fine spiculations are not visible in CE-MRI and therefore there is clinical and diagnostic value in fusing the high-resolution structural information available from mammography with the functional data acquired from MRI imaging. This paper presents a novel data fusion technique whereby medial-lateral oblique (MLO) and cranial-caudal (CC) mammograms (2D data) are registered to 3D contrast-enhanced MRI volumes. We utilise a combination of pharmacokinetic modelling, projection geometry, wavelet-based landmark detection and thin-plate spline non-rigid 'warping' to transform the coordinates of regions of interest (ROIs) from the 2D mammograms to the spatial reference frame of the contrast-enhanced MRI volume. Of key importance is the use of a flexible wavelet-based feature extraction technique that enables feature correspondences to be robustly determined between the very different image characteristics of X-ray mammography and MRI. An evaluation of the fusion framework is demonstrated with a series of clinical cases and a total of 14 patient examples.

  18. Hemodynamic changes in patients with extracorporeal membrane oxygenation (ECMO) demonstrated by contrast-enhanced CT examinations - implications for image acquisition technique.

    Science.gov (United States)

    Lambert, Lukas; Grus, Tomas; Balik, Martin; Fichtl, Jaromir; Kavan, Jan; Belohlavek, Jan

    2016-10-30

    Extracorporeal membrane oxygenation (ECMO) is an established tool for respiratory and circulatory support. In computed tomography, altered hemodynamics in ECMO patients requires special considerations and handling in contrast injection and its timing. In this article, we demonstrate changes in hemodynamics in ECMO patients captured on contrast-enhanced CT examinations and pitfalls in strategies for contrast injection in relation to the ECMO flow, cardiac function and the placement of ECMO cannulas. Contrast-enhanced CT of patients with ECMO requires prior knowledge of the ECMO cannulas, central venous lines, changes of hemodynamics induced by low cardiac output and the influence of adjustment of ECMO on blood flow in order to optimize injection of the contrast material and timing of the scan. Special considerations include temporary reduction of the ECMO flow, selection of the injection site and increasing volume or flow rate of the contrast material.

  19. Diagnosis of deep vein thrombosis using multi-detector helical CT

    Energy Technology Data Exchange (ETDEWEB)

    Kimura, Masashi; Minamiguchi, Hiroki; Sahara, Shinya [Wakayama Medical Coll. (Japan)] [and others

    2002-11-01

    The purpose of this study was to evaluate the usefulness of multi-detector helical CT (MDHCT) with contrast medium in the diagnosis of deep vein thrombosis (DVT). The bilateral veins of the dorsal pedis in 45 patients (12 men, 33 women; average age, 64 years) under clinical suspicion of DVT were first punctured using 22-G needles. Then CT scanning from the level of the foot to the inferior vena cava was started 20 sec after the initial injection of 200 mL of dilute contrast medium (50 mL nonionic iodinated contrast medium of 300 mgI/mL and 150 mL saline) at a rate of 5 mL/sec. Two patients were excluded because of unsuccessful venous puncture. The average scanning time in 43 patients was 38.5{+-}7.9 seconds. Images of veins from the foot to the inferior vena cava were clearly demonstrated in each case. MDHCT showed DVT in 32 cases and patent deep vein in 11 cases. Simultaneous venography of the lower extremity in 18 patients clearly visualized DVT at the same level detected by contrast MDHCT. MDHCT for the diagnosis of DVT has the advantages of wider scanning rage, shorter scanning time, and finer Z-axis resolution than the other diagnostic modalities. (author)

  20. Synthetic streams in a Gravitational Wave inspiral search with a multi-detector network

    CERN Document Server

    K, Haris

    2014-01-01

    Gravitational Wave Inspiral search with a global network of interferometers when carried in a phase coherent fashion would mimic an effective multi-detector network with synthetic streams constructed by the linear combination of the data from different detectors. For the first time, we demonstrate that the two synthetic data streams pertaining to the two polarizations of Gravitational Wave can be derived prior to the maximum-likelihood analysis in a most natural way using the technique of singular-value-decomposition applied to the network signal-to-noise ratio vector. We construct the network matched filters in combined network plus spectral space which capture both the synthetic streams. We further show that the network LLR is then sum of the LLR of each synthetic stream. The four extrinsic parameters are mapped to the two amplitudes and two phases. The maximization over these is a straightforward approach closely linked to the single detector approach. Towards the end, we connect all the previous works rel...

  1. Multi-detector CT coronary angiographic findings of coronary-to-pulmonary artery fistula

    Energy Technology Data Exchange (ETDEWEB)

    Bae, Jae Seok; Park, Eun Ah; Lim, Ji Yeon; Lee, Whal [Dept. of Radiology, Seoul National University Hospital, Seoul (Korea, Republic of); Park, Jae Hyung [Dept. of Radiology, Myongji Hospital, Seonam University College of Medicine, Goyang (Korea, Republic of)

    2017-01-15

    To evaluate multi-detector CT (MDCT) coronary angiographic findings of coronary-to-pulmonary artery fistula (CPAF). We retrospectively reviewed images of patients with CPAF from the coronary CT angiography (CCTA) database obtained with a 64-channel MDCT between January 2008 and March 2011. We analyzed the CCTA findings for feeding arteries, fistula, association with peripulmonary arterial aneurysms, and the presence of communication between the CPAF and bronchial arteries. Fifty-five of the 15042 (0.37%) patients were diagnosed with CPAFs. The feeding artery was single (n = 18) or multiple (n = 37). The fistula had a single drainage site (n = 54) or multiple drainage sites (n = 1). The mean diameter of the fistulous opening was 2.7 ± 1.4 mm. A peripulmonary arterial aneurysm was present in 24 (44%) patients. Communication between CPAF and bronchial arteries was present in eight (14.5%) patients. MDCT coronary angiography can provide comprehensive morphologic details on CPAF and may help in presurgical or preinterventional planning.

  2. Concepts and trade-offs in velocity estimation with plane-wave contrast-enhanced Doppler.

    Science.gov (United States)

    Tremblay-Darveau, Charles; Williams, Ross; Sheeran, Paul; Milot, Laurent; Bruce, Matthew; Burns, Peter

    2016-07-29

    While long Doppler ensembles are, in principle, beneficial for velocity estimates, short acoustic pulses must be used in microbubble contrast-enhanced Doppler to mitigate microbubble destruction. This introduces inherent trade-offs in velocity estimates with autocorrelators, which are studied here. A model of the autocorrelation function adapted to the microbubble Doppler signal, accounting for transit time, the echo frequency uncertainty and contrast-agent destruction is derived and validated in vitro. It is further demonstrated that a local measurement of the center frequency of the microbubble echo is essential in order to avoid significant bias in velocity estimates arising from the linear and nonlinear frequency-dependent scattering of microbubbles, and compensate the inherent speckle nature of the received echo frequency. For these reasons, broadband Doppler estimators (2D autocorrelator, Radon projection) are better suited than simpler narrowband estimators (1D autocorrelator, 1D Fourier transform) for contrast-enhanced flow assessment. A case study of perfusion in a VX-2 carcinoma using contrast-enhanced planewave Doppler is also shown. We demonstrate that even when considering all uncertainties associated with microbubble-related decorrelation (destruction, pulse bandwidth, transit time, flow gradient) and the need for real-time imaging, a coefficient of variation of 4% on the an axial velocity is achievable with planewave imaging.

  3. Magnetic resonance angiography of the carotid arteries: comparison of unenhanced and contrast enhanced techniques

    Energy Technology Data Exchange (ETDEWEB)

    Kramer, Harald; Nikolaou, Konstantin; Reiser, Maximilian F. [Ludwig Maximilians University, Department of Clinical Radiology, University Hospitals Munich, Grosshadern Campus, Munich (Germany); Runge, Val M. [University of Texas Medical Branch, Department of Radiology, Galveston, TX (United States); Morelli, John N.; Williams, Kenneth D.; Naul, L.G. [Scott and White Memorial Hospital, Department of Radiology, Temple, TX (United States); Wintersperger, Bernd J. [Ludwig Maximilians University, Department of Clinical Radiology, University Hospitals Munich, Grosshadern Campus, Munich (Germany); University of Toronto, Department of Medical Imaging, UHN, MSH and WCH, Toronto (Canada)

    2011-08-15

    To compare different techniques for carotid imaging including contrast-enhanced, unenhanced and dynamic techniques to find an alternative to contrast-enhanced MRA. 43 patients referred for imaging of the carotids were enrolled in this IRB-approved study. Imaging included dark-blood, time-of-flight, ECG-gated SSFP and dynamic and static contrast-enhanced MRA. Two radiologists evaluated all datasets in terms of image quality (vessel lumen, signal homogeneity, diagnostic confidence, preferred technique) on a four-point Likert-scale and in measuring the vessel area. Of the 43 included patients the first 8 subjects served for protocol optimisation and 4 individuals discontinued the examination. Thus 31 datasets served for evaluation. CE-MRA revealed best results for delineation of vessel lumen, signal homogeneity and diagnostic confidence with values of 3.61, 3.42 and 3.77. It was also rated as the most preferred technique. SSFP-MRA was rated second in all categories with values of 3.1, 2.9 and 3.11. This unenhanced technique was the only one showing non-significantly different results in quantitative analysis. SSFP-MRA, an unenhanced form of MRA, represents an alternative to CE-MRA, particularly in patients where administration of gadolinium for CE-MRA may be contraindicated. In contrast to other techniques, SSFP-MRA serves with not significant different results compared to standard CE-MRA. (orig.)

  4. Contrast-enhanced ultrasound in ovarian tumors – diagnostic parameters: method presentation and initial experience

    Science.gov (United States)

    MAXIM, ANITA-ROXANA; BADEA, RADU; TAMAS, ATILLA; TRAILA, ALEXANDRU

    2013-01-01

    The aim of this paper is to discuss and illustrate the use of contrast-enhanced ultrasound in evaluating ovarian tumors compared to conventional ultrasound, Doppler ultrasound and the histopathological analysis and suggest how this technique may best be used to distinguish benign from malignant ovarian masses. We present the method and initial experience of our center by analyzing the parameters used in contrast-enhanced ultrasound in 6 patients with ovarian tumors of uncertain etiology. For examination we used a Siemens ultrasound machine with dedicated contrast software and the contrast agent SonoVue, Bracco. The patients underwent conventional ultrasound, Doppler ultrasound and i.v. administration of the contrast agent. The parameters studied were: inflow of contrast (rise time), time to peak enhancement, mean transit time. The series of patients is part of an extensive prospective PhD study aimed at elaborating a differential diagnosis protocol for benign versus malignant ovarian tumors, by validating specific parameters for contrast-enhanced ultrasound. Although the method is currently used with great success in gastroenterology, urology and senology, its validation in gynecology is still in the early phases. Taking into consideration that the method is minimally invasive and much less costly that CT/MRI imaging, demonstrating its utility in oncologic gynecology would be a big step in preoperative evaluation of these cases. PMID:26527912

  5. Age-related contrast enhancement study of normal bone marrow in lumbar spinal MR imaging

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Young A; Ha, Doo Hoe [Pundang CHA General Hospital, Pochon CHA Univ. College of Medicine, Pochon (Korea, Republic of)

    1999-11-01

    The purpose of this study was to evaluate the degree of contrast enhancement of normal bone marrow in L-spine relating to aging and to determine the range of contrast enhancement in normal bone marrow. We analyzed a total of 120 patients (20 per decade) who had undergone lumbar spinal MRI and who ranged in age from the 2nd decade to more than the 7th. Bone marrow revealed no abnormal pathology. Sagittal T1-weighted spin echo sequences were obtained before and after gadolinium administration. For each sequence, a region of interest was drawn within the L1 vertebral body from the midsagittal slice. Signal intensity (SI) values of each sequence were ascertained and the percentage increase in SI was calculated. After contrast enhancement, lumbar MRI revealed no statistically significant in the percentage increase in SI of normal bone marrow in relation to aging. Most patients (99%) however showed an SI increase of between 10% and 49%. In only four, none of whom were aged over 40, was this increase above 50%. Lumbar MRI, revealed no statistically significant difference in percentage increase in SI in normal bone marrow relating to aging, but when the increase is above 50% in a patient aged over 40, bone marrow pathology should be further investigated.

  6. Glioblastoma Presenting with Steroid-Induced Pseudoregression of Contrast Enhancement on Magnetic Resonance Imaging

    Directory of Open Access Journals (Sweden)

    Marcus D. Mazur

    2012-01-01

    Full Text Available Corticosteroid-induced reduction in contrast enhancement on radiographic imaging is most commonly associated with lymphoma but has been reported in other entities, including glioma. This finding may represent a diagnostic dilemma. Concern that steroid-induced cytotoxicity obscures histological diagnosis of suspected lymphoma may lead to postponement of a biopsy. If glioma is not considered in the differential diagnosis, reduction in tumor contrast enhancement may be misinterpreted as disease regression rather than a transient radiographic change. We report a case of a patient with an enhancing right temporoparietal mass adjacent to the atrium of the lateral ventricle. After treatment with dexamethasone was started, the mass exhibited marked reduction in contrast enhancement, with symptom improvement. The clinical course suggested lymphoma, and surgery was not performed. Subsequent screening for extra-axial lymphoma was negative. Two weeks later, the patient developed worsening symptoms, and repeat T1-weighted imaging showed interval increase in size and enhancement. The findings suggested a possible diagnosis of malignant glioma. The patient underwent a stereotactic-guided craniotomy for excision of the right temporoparietal mass lesion. Final histological diagnosis was glioblastoma multiforme, World Health Organization grade IV.

  7. Clinical Value of Contrast-enhanced Ultrasound in Differentiating Benign and Malignant Focal Liver Lesions

    Institute of Scientific and Technical Information of China (English)

    XU Jinfeng; WU Ying; DONG Fajin; XIONG Yi; PENG Qihui; XIE Mingxing

    2007-01-01

    To explore the clinical value of contrast-enhanced ultrasound (CEUS) in differentiating benign and malignant focal liver lesions (FLLs) with SonoVue, CEUS was used to examine 113 pa- tients with focal liver lesions (FLLs) in our hospital during July 2005 to December 2006. All the pa- tients underwent contrast-enhanced CT (CECT) or contrast-enhanced MRI(CEMRI). Except for pa- tients with focal fatty sparings (n=18) and with hemangiomas (n=8), all the patients were confirmed by operation or ultrasonic-guided liver puncture biopsy. A sulfur hexafluoride gas-based contrast agent was used with a MI of 0.15 to 0.17. Forty-eight cases of malignant FLLs, including 30 hepato- cellular carcinomas (HCCs), 2 cholangiocarcinomas and 16 metastatic tumors, were detected. Sev- enty-eight cases of benign FLLs, including 33 hemangiomas, 9 focal nodular hyperplasias (FNHs), 19 focal fatty sparings, 5 abscesses, 7 regenerative nodules and 2 inflammatory pseudo-tumor, were in- volved. The contrast pattern of benign and malignant FLLs was quite different. CEUS has higher specificity and sensitivity than conventional ultrasound in differentiating benign and malignant FLLs.

  8. EFFECT OF SEDATION ON CONTRAST-ENHANCED ULTRASONOGRAPHY OF THE SPLEEN IN HEALTHY DOGS.

    Science.gov (United States)

    Rossi, Federica; Fina, Caroline; Stock, Emmelie; Vanderperren, Katrien; Duchateau, Luc; Saunders, Jimmy H

    2016-05-01

    Contrast-enhanced ultrasound of the spleen enables the dynamic assessment of the perfusion of this organ, however, both subjective and quantitative evaluation can be strongly influenced by sedative agent administration. The purpose of this prospective, experimental study was to test effects of two sedative agents on splenic perfusion during contrast-enhanced ultrasound of the spleen in a sample of healthy dogs. Contrast-enhanced ultrasound of the spleen was repeated in six healthy Beagles following a cross-over study design comparing three protocols: awake, butorphanol 0.2 mg/Kg intramuscular (IM), and dexmedetomidine 500 μg/m(2) IM. After intravenous injection of a phospholipid stabilized sulfur hexafluoride microbubble solution (SonoVue®, Bracco Imaging, Milano, Italy), the enhancement intensity and perfusion pattern of the splenic parenchyma were assessed and perfusion parameters were calculated. Normal spleen was slightly heterogeneous in the early phase, but the parenchyma was homogeneous at a later phase. Sedation with butorphanol did not modify perfusion of the spleen. Dexmedetomidine significantly reduced splenic enhancement, providing diffuse parenchymal hypoechogenicity during the entire examination. Measured parameters were significantly modified, with increased arrival time (AT; (spleen in the early venous phase was determined to be a normal finding.

  9. Contrast-induced nephropathy in patients with renal insufficiency undergoing contrast-enhanced MDCT

    Energy Technology Data Exchange (ETDEWEB)

    Murakami, Ryusuke; Hayashi, Hiromitsu; Sugizaki, Ken-ichi; Yoshida, Tamiko; Okazaki, Emi; Kumita, Shin-ichiro; Owan, Chojin [Nippon Medical School, Department of Radiology, Graduate School of Medicine, Tokyo (Japan)

    2012-10-15

    To evaluate the safety of contrast-enhanced MDCT in patients with renal impairment. We conducted a retrospective review of 938 patients with stable renal insufficiency (eGFR between 15 and 60 ml/min) who underwent contrast-enhanced MDCT. SCr levels were measured at baseline and 48-72 h after contrast medium administration. The incidence of contrast-induced nephropathy (CIN) in the total study population was assessed. As a control group, 1,164 separate patients with renal insufficiency who did not receive contrast medium for CT were also reviewed. The overall incidence of CIN in the patient population with renal insufficiency was 6.1 %; the incidence was 4.4 %, 10.5 % and 10.0 % for patients whose eGFR was 45-60, 30-45 and {<=}30 ml/min, respectively (P < 0.01). In the control group, 5.8 % of patients showed an increase in the SCr level from the baseline. The increase in the SCr level showed no significant difference between the patients who received CM and those who did not (P = 0.82) The risk of CIN from contrast-enhanced MDCT in patients with renal insufficiency appeared to be low, and there was no significant difference in the incidence of CIN in comparison with patients who did not receive CM. (orig.)

  10. Meta-analysis: Serum creatinine changes following contrast enhanced CT imaging

    Energy Technology Data Exchange (ETDEWEB)

    Kooiman, Judith, E-mail: j.kooiman@lumc.nl [Department of Thrombosis and Haemostasis, LUMC, Leiden (Netherlands); Pasha, Sharif M., E-mail: s.m.pasha@lumc.nl [Department of Thrombosis and Haemostasis, LUMC, Leiden (Netherlands); Zondag, Wendy, E-mail: w.zondag@lumc.nl [Department of Thrombosis and Haemostasis, LUMC, Leiden (Netherlands); Sijpkens, Yvo W.J., E-mail: ysijpens@bronovo.nl [Department of Nephrology, Bronovo Hospital, The Hague (Netherlands); Molen, Aart J. van der, E-mail: molen@lumc.nl [Department of Radiology, LUMC, Leiden (Netherlands); Huisman, Menno V., E-mail: m.v.huisman@lumc.nl [Department of Thrombosis and Haemostasis, LUMC, Leiden (Netherlands); Dekkers, Olaf M., E-mail: o.m.dekkers@lumc.nl [Department of Clinical Epidemiology and Department of Endocrinology, LUMC, Leiden (Netherlands)

    2012-10-15

    Purpose: Contrast induced nephropathy (CIN) is defined as a decrease in renal function following administration of contrast media. The aim of this meta-analysis was to asses the overall risk of CIN, chronic loss of kidney function and the need for renal replacement therapy (RRT) after intravenous contrast enhanced CT-scan. Secondly, we aimed to identify subgroups at increased risk for CIN. Materials and methods: A literature search in Pubmed, Medline, Embase and Cochrane databases was performed. Data extraction was carried out independently by two reviewers. Meta-analysis and meta-regression were performed using an exact likelihood approach. Results: Forty studies evaluating the incidence of CIN after CT were included. The pooled incidence of CIN was 6.4% (95% CI 5.0–8.1). The risk of RRT after CIN was low, 0.06% (95% CI 0.01–0.4). The decline in renal function persisted in 1.1% of patients (95% CI 0.6–2.1%). Patients with chronic kidney disease (odds ratio 2.26, p < 0.001) or diabetes mellitus (odds ratio 3.10, p < 0.001) were at increased risk for the development of CIN. Conclusion: CIN occurred in 6% of patients after contrast enhanced CT. In 1% of all patients undergoing contrast enhanced CT the decline in renal function persisted.

  11. Contrast-enhanced ultrsonography advanced and currrent status in abdominal imaging

    Energy Technology Data Exchange (ETDEWEB)

    Chung Yong Eun; Kim Ki Whang [Dept. of Radiology, Research Institute of Radiological Science, Yonsei University College of Medicine, Seoul (Korea, Republic of)

    2015-01-15

    n the field of contrast-enhanced ultrasonography (US), contrast agents are classified as either first- or second-generation agents depending on the gas within the microbubbles. In the case of first-generation contrast agents, a high-mechanical-index technique is used and only intermittent scanning is possible due to the early destruction of the microbubbles during the scanning. The use of second-generation contrast agents in a low-mechanical-index technique enables continuous scanning. Besides the detection and characterization of focal liver lesions, contrastenhanced US is helpful in the monitoring of radiofrequency ablation therapy and in the targeting step of an US-guided biopsy. Recently, there has been a demand for new criteria to evaluate the treatment response obtained using anti-angiogenic agents because morphologic criteria alone may not reflect the treatment response of the tumor and contrast-enhanced US can provide quantitative markers of tissue perfusion. In spite of the concerns related to its cost-effectiveness, contrast-enhanced US has the potential to be more widely used as a complimentary tool or to substitute the current imaging modalities in some occasions.

  12. Non-contrast-enhanced renal and abdominal MR angiography using velocity-selective inversion preparation.

    Science.gov (United States)

    Shin, Taehoon; Worters, Pauline W; Hu, Bob S; Nishimura, Dwight G

    2013-05-01

    Non-contrast-enhanced MR angiography is a promising alternative to the established contrast-enhanced approach as it reduces patient discomfort and examination costs and avoids the risk of nephrogenic systemic fibrosis. Inflow-sensitive slab-selective inversion recovery imaging has been used with great promise, particularly for abdominal applications, but has limited craniocaudal coverage due to inflow time constraints. In this work, a new non-contrast-enhanced MR angiography method using velocity-selective inversion preparation is developed and applied to renal and abdominal angiography. Based on the excitation k-space formalism and Shinnar-Le-Roux transform, a velocity-selective excitation pulse is designed that inverts stationary tissues and venous blood while preserving inferiorly flowing arterial blood. As the magnetization of the arterial blood in the abdominal aorta and iliac arteries is well preserved during the magnetization preparation, artery visualization over a large abdominal field of view is achievable with an inversion delay time that is chosen for optimal background suppression. Healthy volunteer tests demonstrate that the proposed method significantly increases the extent of visible arteries compared with the slab-selective approach, covering renal arteries through iliac arteries over a craniocaudal field of view of 340 mm. Copyright © 2012 Wiley Periodicals, Inc.

  13. High-relaxivity contrast-enhanced magnetic resonance neuroimaging: a review

    Energy Technology Data Exchange (ETDEWEB)

    Giesel, Frederik L. [German Cancer Research Centre (DKFZ), Department of Radiology E010, Heidelberg (Germany); University of Heidelberg, Nuclear Medicine, Heidelberg (Germany); Mehndiratta, Amit [German Cancer Research Centre (DKFZ), Department of Radiology E010, Heidelberg (Germany); Harvard Medical School, Department of Radiology, Massachusetts General Hospital, Boston, MA (United States); Essig, Marco [German Cancer Research Centre (DKFZ), Department of Radiology E010, Heidelberg (Germany)

    2010-10-15

    Evaluation of brain lesions using magnetic resonance imaging (MRI) provides information that is critical for accurate diagnosis, prognosis, therapeutic intervention and monitoring response. Conventional contrast-enhanced MR neuroimaging using gadolinium (Gd) contrast agents primarily depicts disruption of the blood-brain barrier, demonstrating location and extent of disease, and also the morphological details at the lesion site. However, conventional imaging results do not always accurately predict tumour aggressiveness. Advanced functional MRI techniques such as dynamic contrast-enhanced perfusion-weighted imaging utilise contrast agents to convey physiological information regarding the haemodynamics and neoangiogenic status of the lesion that is often complementary to anatomical information obtained through conventional imaging. Most of the Gd contrast agents available have similar T1 and T2 relaxivities, and thus their contrast-enhancing capabilities are comparable. Exceptions are gadobenate-dimeglumine, Gd-EOB-DTPA, Gadobutrol and gadofosveset, which, owing to their transient-protein-binding capability, possess almost twice (and more) the T1 and T2 relaxivities as other agents at all magnetic field strengths. Numerous comparative studies have demonstrated the advantages of the increased relaxivity in terms of enhanced image contrast, image quality and diagnostic confidence. Here we summarise the benefits of higher relaxivity for the most common neuroimaging applications including MRI, perfusion-weighted imaging and MRA for evaluation of brain tumours, cerebrovascular disease and other CNS lesions. (orig.)

  14. Examination of patient factors and contrast medium factors that exert influence on contrast enhancement

    Energy Technology Data Exchange (ETDEWEB)

    Yamaguchi, Isao; Morimoto, Akira; Shouga, Kazuhiko; Suzuki, Noriyuki [Kure Kyosai Hospital, Hiroshima (Japan)

    2002-04-01

    The purpose of this study was to determine the relationship between patient factors and contrast medium factors, both of which influence contrast enhancement. Our goal was to achieve improved standardization and reproducibility of enhancement based on the findings of this study. Enhancement units (EU) and the contrast enhancement index (CE index) were calculated in the areas of the hepatic parenchyma and abdominal aorta in 370 subjects who underwent our hepatic dynamic study. We analyzed the obtained values in terms of differences in age, sex, body weight, iodine volume per body weight, and volume and concentration of contrast medium. Changes in EU values were dependent on total iodine volume and body weight, showing a positive correlation with iodine volume per body weight. When assessed in terms of fixed total volume, the values were found to show a negative correlation with body weight. The obtained CE index values were closely distributed on a fixed iodine volume per weight, with slight variations that were related to sex, body weight, and age. Particularly, in the analysis of changes in enhancement levels according to age, a notable increase in contrast enhancement in inverse relationship with decline in glomerular filtration rate (GFR) with aging was observed. (author)

  15. Statistical comparison of dynamic contrast-enhanced MRI pharmacokinetic models in human breast cancer.

    Science.gov (United States)

    Li, Xia; Welch, E Brian; Chakravarthy, A Bapsi; Xu, Lei; Arlinghaus, Lori R; Farley, Jaime; Mayer, Ingrid A; Kelley, Mark C; Meszoely, Ingrid M; Means-Powell, Julie; Abramson, Vandana G; Grau, Ana M; Gore, John C; Yankeelov, Thomas E

    2012-07-01

    By fitting dynamic contrast-enhanced MRI data to an appropriate pharmacokinetic model, quantitative physiological parameters can be estimated. In this study, we compare four different models by applying four statistical measures to assess their ability to describe dynamic contrast-enhanced MRI data obtained in 28 human breast cancer patient sets: the chi-square test (χ(2)), Durbin-Watson statistic, Akaike information criterion, and Bayesian information criterion. The pharmacokinetic models include the fast exchange limit model with (FXL_v(p)) and without (FXL) a plasma component, and the fast and slow exchange regime models (FXR and SXR, respectively). The results show that the FXL_v(p) and FXR models yielded the smallest χ(2) in 45.64 and 47.53% of the voxels, respectively; they also had the smallest number of voxels showing serial correlation with 0.71 and 2.33%, respectively. The Akaike information criterion indicated that the FXL_v(p) and FXR models were preferred in 42.84 and 46.59% of the voxels, respectively. The Bayesian information criterion also indicated the FXL_v(p) and FXR models were preferred in 39.39 and 45.25% of the voxels, respectively. Thus, these four metrics indicate that the FXL_v(p) and the FXR models provide the most complete statistical description of dynamic contrast-enhanced MRI time courses for the patients selected in this study.

  16. Automated mass detection in contrast-enhanced CT colonography: an approach based on contrast and volume

    Energy Technology Data Exchange (ETDEWEB)

    Luboldt, W. [University Hospital Essen, Clinic and Policlinic of Angiology, Essen (Germany); Multiorgan Screening Foundation (Germany); Tryon, C. [Philips Medical Systems, Best (Netherlands); Kroll, M.; Vogl, T.J. [University Hospital Frankfurt, Department of Radiology, Frankfurt (Germany); Toussaint, T.L. [Multiorgan Screening Foundation (Germany); Holzer, K. [University Hospital Frankfurt, Department of Visceral and Vascular Surgery, Frankfurt (Germany); Hoepffner, N. [University Hospital Frankfurt, Department of Gastroenterology, Frankfurt (Germany)

    2005-02-01

    The purpose of this feasibility study was to design and test an algorithm for automating mass detection in contrast-enhanced CT colonography (CTC). Five patients with known colorectal masses underwent a pre-surgical contrast-enhanced (120 ml volume 1.6 g iodine/s injection rate, 60 s scan delay) CTC in high spatial resolution (16-slice CT: collimation: 16 x 0.75 mm, tablefeed: 24 mm/0.5 s, reconstruction increment: 0.5 mm). A CT-density- and volume-based algorithm searched for masses in the colonic wall, which was extracted before by segmenting and dilating the colonic air lumen and subtracting the inner air. A radiologist analyzed the detections and causes of false positives. All masses were detected, and false positives were easy to identify. Combining CT density with volume as a cut-off is a promising approach for automating mass detection that should be further refined and also tested in contrast-enhanced MR colonography. (orig.)

  17. Contrast-enhanced magnetic resonance imaging for the detection of acute haemorrhagic necrotizing pancreatitis

    Energy Technology Data Exchange (ETDEWEB)

    Piironen, A. [Department of Radiology, Helsinki University Central Hospital, Helsinki (Finland); Kivisaari, R. [Department of Radiology, Helsinki University Central Hospital, Helsinki (Finland); Pitkaeranta, P. [Department of Radiology, Helsinki University Central Hospital, Helsinki (Finland); Poutanen, V.P. [Department of Radiology, Helsinki University Central Hospital, Helsinki (Finland); Laippala, P. [School of Public Health/Biometry Unit, Tampere University, Tampere (Finland); Laurila, P. [Department of Pathology, Helsinki Univ. (Finland); Kivisaari, L. [Department of Radiology, Helsinki University Central Hospital, Helsinki (Finland)

    1997-02-01

    Eleven piglets with haemorrhagic necrotizing pancreatitis and nine piglets with oedematous pancreatitis were imaged using a multi-breath-hold TurboFLASH (TR 6.5 ms, TE 3 ms, TI 300 ms, flip angle 8 , three slices) pre-excited T1-weighted sequence with an IV bolus injection of gadopentetate dimeglumine (Gd-DTPA, 0.3 mmol/kg) as a contrast agent to show dynamic contrast enhancement of the pancreas by MRI. All piglets were imaged according to the same protocol before inducing the disease. Following the IV Gd-DTPA bolus, time-enhancement curve of the pancreas during haemorrhagic necrotizing pancreatitis was significantly lower than during oedematous pancreatitis. The enhancement curves for the healthy piglets and piglets with oedematous pancreatitis did not differ significantly. Each piglet served as its own control. Because the results of this initial study are similar to those obtained with contrast-enhanced CT, we conclude that our results may encourage further clinical trials, and contrast-enhanced dynamic MRI may be an alternative to the established method of CT for diagnosing acute haemorrhagic necrotizing pancreatitis. (orig.). With 3 figs.

  18. Contrast-Enhanced Harmonic Ultrasonography for the Assessment of Prostate Cancer Aggressiveness: a Preliminary Study

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Yunkai; Chen, Yaqing; Jiang, Jun [Xinhua Hospital Affiliated to Shanghai Jiaotong University School of Medicine, Shanghai (China); Wang, Ren; Zhou, Yongchang; Zhang, Huizhen [Sixth People' s Hospital Affiliated to Shanghai Jiaotong University, Shanghai (China)

    2010-02-15

    To determine whether contrast-enhanced harmonic ultrasonography can be used to predict the aggressiveness of prostate cancer. Contrast-enhanced harmonic ultrasonography was performed in 103 patients suspected of prostate cancer before biopsy. Time intensity curves were reconstructed for systematic biopsy sites and sonographic abnormalities. The characteristics of the curves were described using hemodynamic indices including arrival time (AT), time-to-peak (TTP), and peak intensity (PI). The differences of hemodynamic indices between high-grade and low-grade cancer were analyzed and the correlations between the hemodynamic indices and biopsy Gleason score were studied. Prostate cancer was detected in 41 of 103 patients and there were significant differences in the hemodynamic indices between the biopsy sites of the non-malignant patients and prostate cancer lesions (p < 0.05). The prostate biopsies revealed 154 prostate cancer lesions, including 31 low-grade lesions and 123 high-grade lesions. The hemodynamic indices AT and TTP of highgrade tumors were significantly shorter than those of low-grade tumors (p = 0.001, 0.002). In addition, high-grade peripheral zone (PZ) tumors had higher PI than low-grade PZ tumors (p = 0.009). The PZ prostate cancer Gleason score correlated with PI, AT and TTP, with Spearman correlation coefficients of 0.223, -0.335, and -0.351, respectively (p = 0.013, < 0.001 and < 0.001). Contrast-enhanced ultrasound measurements of hemodynamic indices correlate with the prostate cancer Gleason score.

  19. Clinical value of classification of venous malformations with contrast-enhanced MR Angiography.

    Science.gov (United States)

    Abdel Razek, Ahmed Abdel Khalek; Albair, Germeen Ashmalla; Samir, Sieza

    2016-12-07

    To classify venous malformations based on contrast-enhanced MR angiography that may serve as a basis for treatment plan. A retrospective analysis was performed in 58 patients with venous malformations who underwent contrast-enhanced MR angiography. Venous malformations were classified according to their venous drainage into: type I, isolated malformation without peripheral drainage; type II, malformation that drains into normal veins; type III, malformation that drains into dilated veins; and type IV, malformation that represents dysplastic venous ectasia. Image analysis was done by two reviewers. Intra and inter-observer agreement of both reviewers and intra-class correlation was done. The intra-observer agreement of contrast-enhanced MR angiography classification of venous malformations was excellent for the first reviewer (k = 0.83, 95% CI = 0.724-0.951, P = 0.001) and substantial for the second reviewer (K = 0.79, 95% CI = 0.656-0.931, P = 0.001). The inter-observer agreement of contrast-enhanced MR angiography classification of venous malformations was excellent for both reviewers at the first time (K = 0.96, 95% CI = 0.933-1.000, P = 0.001) and second time (k = 0.81, 95% CI = 0.678-0.942, P = 0.001). There was high intra-class correlation of both reviewers for single measure (ICC = 0.85, 95% CI = 0.776-0.918, P = 0.001) and for average measures (ICC = 0.96, 95% CI = 0.933-0.978, P = 0.001). Contrast-enhanced MR angiography classification of venous malformations may be a useful, simple and reliable tool to accurately classify venous malformation and this topographic classification helps for better management strategy. © The Author(s) 2016.

  20. Automatic hyperspectral camera for latent fingerprint detection and contrast enhancement. Final report, September 2, 1998 - March 17, 1999

    Energy Technology Data Exchange (ETDEWEB)

    Paul Shnitser

    1999-06-01

    Physical Optics Corporation demonstrated the feasibility of the contrast enhancement of the latent fingerprint by portable hyperspectral imaging camera. The demonstrated non-contact technology is applicable for observation of the low contrast laser excited fluorescence from latent fingerprints as well as for the contrast enhancement of chemically processed fingerprints. Experiments were conducted with fingerprints on various types of substrates.

  1. Three-dimensional contrast enhanced ultrasound score and dynamic contrast-enhanced magnetic resonance imaging score in evaluating breast tumor angiogenesis: Correlation with biological factors

    Energy Technology Data Exchange (ETDEWEB)

    Jia, Wan-Ru, E-mail: jiawanru@126.com [Department of Diagnostic Ultrasound, Rui Jin Hospital, School of Medicine, Shanghai Jiao Tong University, No. 197 Rui Jin 2nd Road, Shanghai 200025 (China); Chai, Wei-Min, E-mail: chai_weimin@yahoo.com.cn [Department of Radiology, Rui Jin Hospital, School of Medicine, Shanghai Jiao Tong University, No. 197 Rui Jin 2nd Road, Shanghai 200025 (China); Tang, Lei, E-mail: jessietang1003@163.com [Department of Diagnostic Ultrasound, Rui Jin Hospital, School of Medicine, Shanghai Jiao Tong University, No. 197 Rui Jin 2nd Road, Shanghai 200025 (China); Wang, Yi, E-mail: xiatian.0602@163.com [Department of Diagnostic Ultrasound, Rui Jin Hospital, School of Medicine, Shanghai Jiao Tong University, No. 197 Rui Jin 2nd Road, Shanghai 200025 (China); Fei, Xiao-Chun, E-mail: xcf0222@163.com [Department of Pathology, Rui Jin Hospital, School of Medicine, Shanghai Jiao Tong University, No. 197 Rui Jin 2nd Road, Shanghai 200025 (China); Han, Bao-San, E-mail: hanbaosan@126.com [Department of Comprehensive Breast Health Center, Rui Jin Hospital, School of Medicine, Shanghai Jiao Tong University, No. 197 Rui Jin 2nd Road, Shanghai 200025 (China); Chen, Man, E-mail: lucyjia1370@126.com [Department of Diagnostic Ultrasound, Rui Jin Hospital, School of Medicine, Shanghai Jiao Tong University, No. 197 Rui Jin 2nd Road, Shanghai 200025 (China)

    2014-07-15

    Objective: To explore the clinical value of three-dimensional contrast enhanced ultrasound (3D-CEUS) and dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) score systems in evaluating breast tumor angiogenesis by comparing their diagnostic efficacy and correlation with biological factors. Methods: 3D-CEUS was performed in 183 patients with breast tumors by Esaote Mylab90 with SonoVue (Bracco, Italy), DCE-MRI was performed on a dedicated breast magnetic resonance imaging (DBMRI) system (Aurora Dedicated Breast MRI Systems, USA) with a dedicated breast coil. 3D-CEUS and DCE-MRI score systems were created based on tumor perfusion and vascular characteristics. Microvessel density (MVD), vascular endothelial growth factor (VEGF) and matrix metalloproteinases (MMP-2, MMP-9) expression were measured by immunohistochemistry. Results: Pathological results showed 35 benign and 148 malignant breast tumors. MVD (P = 0.000, r = 0.76), VEGF (P = 0.000, r = 0.55), MMP-2 (P = 0.000, r = 0.39) and MMP-9 (P = 0.000, r = 0.41) expression were all significantly different between benignity and malignancy. Regarding 3D-CEUS 4 points as cutoff value, the sensitivity, specificity and accuracy were 85.1%, 94.3% and 86.9%, respectively, and correlated well with MVD (P = 0.000, r = 0.50), VEGF (P = 0.000, r = 0.50), MMP-2 (P = 0.000, r = 0.50) and MMP-9 (P = 0.000, r = 0.66). Taking DCE-MRI 5 points as cutoff value, the sensitivity, specificity and accuracy were 86.5%, 94.3% and 88.0%, respectively and also correlated well with MVD (P = 0.000, r = 0.52), VEGF (P = 0.000, r = 0.44), MMP-2 (P = 0.000, r = 0.42) and MMP-9 (P = 0.000, r = 0.35). Conclusions: 3D-CEUS score system displays inspiring diagnostic performance and good agreement with DCE-MRI scoring. Moreover, both score systems correlate well with MVD, VEGF, MMP-2 and MMP-9 expression, and thus have great potentials in tumor angiogen