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Sample records for two-phase contrast-enhanced multidetector-row

  1. Myocardial enhancement pattern in patients with acute myocardial infarction on two-phase contrast-enhanced Ecg-gated multidetector-row computed tomography

    International Nuclear Information System (INIS)

    Ko, S.M.; Seo, J.B.; Hong, M.K.; Do, K.H.; Lee, S.H.; Lee, J.S.; Song, J.W.; Park, S.J.; Park, S.W.; Lim, T.H.

    2006-01-01

    Aim: To evaluate the myocardial enhancement pattern of the left ventricle on two-phase contrast-enhanced electrocardiogram (ECG)-gated multidetector computed tomography (MDCT) images in patients with acute myocardial infarction (AMI). METHODS: Two-phase contrast-enhanced ECG-gated MDCT examinations were performed in 16 patients with AMI. The presence, location and pattern of myocardial enhancement were evaluated. MDCT findings were compared with the catheter angiographic results. RESULTS: Subendocardial (n=9) or transmural (n=6) area of early perfusion defects of the myocardium was detected in 15 of 16 patients (94%) on early-phase CT images. Variable delayed myocardial enhancement patterns on late-phase CT images were observed in 12 patients (75%): (1) subendocardial residual perfusion defect and subepicardial late enhancement (n=6); (2) transmural late enhancement (n=1); (3) isolated subendocardial late enhancement (n=1); and (4) isolated subendocardial residual perfusion defect (n=2). On catheter angiography, 14 of 15 corresponding coronary arteries showed significant stenosis. CONCLUSION: Variable abnormal myocardial enhancement pattern was seen on two-phase, contrast-enhanced ECG-gated MDCT in patients with AMI. Assessment of myocardial attenuation on CT angiography gives additional information of the location and extent of infarction

  2. Abdominal multi-detector row CT: Effectiveness of determining contrast medium dose on basis of body surface area

    International Nuclear Information System (INIS)

    Onishi, Hiromitsu; Murakami, Takamichi; Kim, Tonsok; Hori, Masatoshi; Osuga, Keigo; Tatsumi, Mitsuaki; Higashihara, Hiroki; Maeda, Noboru; Tsuboyama, Takahiro; Nakamoto, Atsushi; Tomoda, Kaname; Tomiyama, Noriyuki

    2011-01-01

    Purpose: To investigate the validity of determining the contrast medium dose based on body surface area (BSA) for the abdominal contrast-enhanced multi-detector row CT comparing with determining based on body weight (BW). Materials and methods: Institutional review committee approval was obtained. In this retrospective study, 191 patients those underwent abdominal contrast-enhanced multi-detector row CT were enrolled. All patients received 96 mL of 320 mg I/mL contrast medium at the rate of 3.2 mL. The iodine dose required to enhance 1 HU of the aorta at the arterial phase and that of liver parenchyma at portal venous phase per BSA were calculated (EU BSA ) and evaluated the relationship with BSA. Those per BW were also calculated (EU BW ) and evaluated. Estimated enhancement values (EEVs) of the aorta and liver parenchyma with two protocols for dose decision based on BSA and BW were calculated and patient-to-patient variability was compared between two protocols using the Levene test. Results: The mean of EU BSA and EU BW were 0.0621 g I/m 2 /HU and 0.00178 g I/kg/HU for the aorta, and 0.342 g I/m 2 /HU and 0.00978 g I/kg/HU for the liver parenchyma, respectively. In the aortic enhancement, EU BSA was almost constant regardless of BSA, and the mean absolute deviation of the EEV with the BSA protocol was significantly lower than that with the BW protocol (P < .001), although there was no significant difference between two protocols in the hepatic parenchymal enhancement (P = .92). Conclusion: For the aortic enhancement, determining the contrast medium dose based on BSA was considered to improve patient-to-patient enhancement variability.

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

    International Nuclear Information System (INIS)

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

    2008-01-01

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

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

    International Nuclear Information System (INIS)

    Moselewski, Fabian; Ferencik, Maros; Achenbach, Stephan; Abbara, Suhny; Cury, Ricardo C.; Booth, Sarah L.; Jang, Ik-Kyung; Brady, Thomas J.; Hoffmann, Udo

    2006-01-01

    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

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  6. Multi-detector row computed tomography angiography of peripheral arterial disease

    International Nuclear Information System (INIS)

    Kock, Marc C.J.M.; Dijkshoorn, Marcel L.; Pattynama, Peter M.T.; Myriam Hunink, M.G.

    2007-01-01

    With the introduction of multi-detector row computed tomography (MDCT), scan speed and image quality has improved considerably. Since the longitudinal coverage is no longer a limitation, multi-detector row computed tomography angiography (MDCTA) is increasingly used to depict the peripheral arterial runoff. Hence, it is important to know the advantages and limitations of this new non-invasive alternative for the reference test, digital subtraction angiography. Optimization of the acquisition parameters and the contrast delivery is important to achieve a reliable enhancement of the entire arterial runoff in patients with peripheral arterial disease (PAD) using fast CT scanners. The purpose of this review is to discuss the different scanning and injection protocols using 4-, 16-, and 64-detector row CT scanners, to propose effective methods to evaluate and to present large data sets, to discuss its clinical value and major limitations, and to review the literature on the validity, reliability, and cost-effectiveness of multi-detector row CT in the evaluation of PAD. (orig.)

  7. 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

  8. Multi-detector row CT of the kidney: Optimizing scan delays for bolus tracking techniques of arterial, corticomedullary, and nephrographic phases

    Energy Technology Data Exchange (ETDEWEB)

    Goshima, Satoshi [Department of Radiology, Gifu University School of Medicine, 1-1 Yanagido, Gifu 501-1193 (Japan); Kanematsu, Masayuki [Department of Radiology, Gifu University School of Medicine, 1-1 Yanagido, Gifu 501-1193 (Japan); Department of Radiology Services, Gifu University School of Medicine, 1-1 Yanagido, Gifu 501-1193 (Japan); Nishibori, Hironori; Kondo, Hiroshi; Tsuge, Yusuke [Department of Radiology, Gifu University School of Medicine, 1-1 Yanagido, Gifu 501-1193 (Japan); Yokoyama, Ryujiro; Miyoshi, Toshiharu [Department of Radiology Services, Gifu University School of Medicine, 1-1 Yanagido, Gifu 501-1193 (Japan); Onozuka, Minoru [Department of Physiology and Neuroscience, Kanagawa Dental College, Yokosuka, Kanagawa (Japan); Shiratori, Yoshimune [Department of Medical Informatics, Gifu University School of Medicine, Gifu (Japan); Moriyama, Noriyuki [Department of Diagnostic Radiology, National Cancer Center Hospital, Tsukiji, Chuo-Ku, Tokyo (Japan); Bae, Kyongtae T. [Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, MO (United States)

    2007-09-15

    Purpose: To determine optimal scan delays for renal arterial-, corticomedullary-, and nephrographic-phase imaging with multi-detector row computed tomography (MDCT) of the kidney using a bolus-tracking technique. Methods and materials: One hundred and twenty-eight patients underwent three-phase CT scan of the kidney with eight-row MDCT after receiving 2 mL/kg of 300 mg I/mL contrast medium at 4 mL/s. Patients were prospectively randomized into three groups with different scan delays for the three scan phases (arterial, corticomedullary, and nephrographic) after bolus-tracking triggered at 50 HU of aortic contrast enhancement: group 1 (5, 20, 45 s); group 2 (10, 25, 50 s); and group 3 (15, 30, 55 s). Mean CT values (HU) of the abdominal aorta, renal artery, renal vein, renal cortex, and renal medulla were measured; increases in CT values pre- to post-contrast were assessed as contrast enhancement. Renal artery-to-vein and renal cortex-to-medulla contrast differences were also assessed. Qualitative analysis was also performed. Results: Mean renal artery enhancement was 240-288 HU at 5-15 s after the trigger and peaked at 10 s (P < .001). Mean renal cortical enhancement was 195-217 HU at 10-30 s and peaked at 25 s (P < .01). Contrast enhancement in the renal medulla increased gradually and reached mean 145 HU at 55 s. Cortex-to-medulla contrast difference was high (110-140 HU) at 5-30 s and decreased below 30 HU at 45 s after the trigger. Renal artery-to-vein contrast difference was high (121-125 HU) at 5-10 s. Qualitative results correlated well with quantitative results. Conclusion: For the injection protocol used in this study, optimal scan delays after the bolus-tracking trigger were 5-10 s for renal arterial, 15-25 s for corticomedullary, and 50-55 s for nephrographic phases.

  9. Multi-detector row helical CT of the liver. Quantitative assessment of iodine concentration of intravenous contrast material on multiphasic CT. A prospective randomized study

    International Nuclear Information System (INIS)

    Tsurusaki, Masakatsu; Sugimoto, Koji; Fujii, Masahiko; Sugimura, Kazuro

    2004-01-01

    The purpose of this study was to assess the quantitative effects of contrast material concentration on hepatic parenchymal and vascular enhancement in multiphasic computed tomography (CT), using multi-detector row helical CT. We designed a prospective randomized study to test two different concentrations of contrast material on five phasic scans of the liver. One hundred patients were randomly assigned to two groups: an iodine concentration of 300 mg/mL in group A and 370 mg/mL in group B. All patients received a fixed volume of 100 mL at a 4 mL/sec injection rate. Enhancement values for the hepatic parenchyma and aorta at three levels (upper, middle, and lower level of the liver), and values for portal and hepatic veins were statistically compared between the two groups. Hepatic parenchymal enhancement values at all levels of the liver in portal phase (PP) and equilibrium phase (EP) were significantly higher in group B than in group A (p<0.01). Aortic enhancement values at two levels of the liver (middle and lower) in early hepatic arterial phase (EAP) were significantly higher in group B than in group A (p<0.05), however, there was no significant difference between groups A and B in aortic enhancement during the delayed hepatic arterial phase (DAP). Portal and hepatic venous enhancement values in PP and EP were significantly higher in group B than in group A (p<0.01). On multiphasic dynamic CT, the use of a higher iodine concentration of contrast material results in higher hepatic parenchymal enhancement and aortic enhancement, as well as higher portal and hepatic venous enhancement. (author)

  10. Sacroiliitis in Ankylosing Spondylitis: Comparison with Multidetector Row CT and Plain Radiography

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    Yu, Ji Youn; Joo, Kyung Bin; Choi, Byeong Kyoo; Ryu, Jeong Ah; Kim, Tae Hwan; Choi, Woo Jung [Hanyang University Hospital, Seoul (Korea, Republic of)

    2009-03-15

    The objective of our study was to compare multidetector row CT and the plain radiographs for making the diagnosis and grading the sacroiliitis that accompanies ankylosing spondylitis. We wanted to determine the role of multidetector row CT for the evaluation of the sacroilitis in patients with ankylosing spondylitis. One hundred ninety two patients with clinically suspected ankylosing spondylitis were evaluated by conventional radiography and multidetector row CT. Two musculoskeletal radiologists retrospectively analyzed the images, and they graded the sacroiliitis using the modified New York Criteria. Multidetector row CT demonstrated a significantly higher sensitivity (74.5%, 83.3%) than did plain radiography (59.9%, 66.7%) for detecting early sacroiliitis (p<0.05). Multidetector row CT showed a higher grade of sacroiliitis in 114 and 127 of 384 sacroiliac joints. Performing multidetector row CT rather than plain radiography for making the diagnoses of accompanying ankylosing spondylitis allows an early start of treatment with a subsequently improved prognosis

  11. Upper abdominal gadoxetic acid-enhanced and diffusion-weighted MRI for the detection of gastric cancer: Comparison with two-dimensional multidetector row CT

    International Nuclear Information System (INIS)

    Jang, K.M.; Kim, S.H.; Lee, S.J.; Lee, M.W.; Choi, D.; Kim, K.M.

    2014-01-01

    Aim: To evaluate the diagnostic performance of abdominal magnetic resonance imaging (MRI) for the detection of gastric cancer in comparison with that of two-dimensional (2D) multidetector row computed tomography (CT). Materials and methods: The study included 189 patients with 170 surgically confirmed gastric cancers and 19 patients without gastric cancer, all of whom underwent gadoxetic acid-enhanced MRI with diffusion-weighted (DW) imaging, and multidetector contrast-enhanced abdominal CT imaging. Two observers independently analysed three sets of images (CT set, conventional MRI set, and combined conventional and DW MRI set). A five-point scale for likelihood of gastric cancer was used. Diagnostic accuracy, sensitivity, specificity, positive predictive value, and negative predictive value were evaluated. Quantitative [apparent diffusion coefficient (ADC) analyses with Mann–Whitney U-test were conducted for gastric cancers and the nearby normal gastric wall. Results: The diagnostic accuracy and sensitivity for detection of gastric cancer were significantly higher on combined conventional and DW MRI set (77.8–78.3%; 75.3–75.9%) than the CT imaging set (67.7–71.4%; 64.1–68.2%) or the conventional MRI set (72–73%; 68.8–70%; p < 0.01). In particular, for gastric cancers with pT2 and pT3, the combined conventional and DW MRI set (91.6–92.6%) yielded significantly higher sensitivity for detection of gastric cancer than did the CT imaging set (76.8–81.1%) by both observers (p < 0.01). The mean ADC of gastric cancer lesions (1 ± 0.23 × 10 −3 mm 2 /s) differed significantly from that of normal gastric wall (1.77 ± 0.25 × 10 −3  mm 2 /s; p < 0.01). Conclusion: Abdominal MRI with DW imaging was more sensitive for the detection of gastric cancer than 2D-multidetector row CT or conventional MRI alone. - Highlights: • The sensitivity for detection of gastric cancer is high on abdominal MR imaging. • DW imaging is helpful for

  12. Multidetector-row CT: economics and workflow

    International Nuclear Information System (INIS)

    Pottala, K.M.; Kalra, M.K.; Saini, S.; Ouellette, K.; Sahani, D.; Thrall, J.H.

    2005-01-01

    With rapid evolution of multidetector-row CT (MDCT) technology and applications, several factors such ad technology upgrade and turf battles for sharing cost and profitability affect MDCT workflow and economics. MDCT workflow optimization can enhance productivity and reduce unit costs as well as increase profitability, in spite of decrease in reimbursement rates. Strategies for workflow management include standardization, automation, and constant assessment of various steps involved in MDCT operations. In this review article, we describe issues related to MDCT economics and workflow. (orig.)

  13. Multidetector-row computed tomography coronary angiography. Optimization of image reconstruction phase according to the heart rate

    International Nuclear Information System (INIS)

    Nagatani, Yukihiro; Takahashi, Masashi; Takazakura, Ryutaro; Nitta, Norihisa; Murata, Kiyoshi; Ushio, Noritoshi; Matsuo, Shinro; Yamamoto, Takashi; Horie, Minoru

    2007-01-01

    The purpose of this study was to optimize the image reconstruction phase of multidetector-row computed tomography (MDCT) coronary angiography according to the heart rate is crucial. Scan data were reconstructed for 10 different phases in 58 sequential patients who under went 8-row cardiac MDCT. The obtained images were scored and compared in terms of motion artifacts and visibility of the vessels, and moreover, electrocardiogram (ECG) record-based evaluations were added for clarification of the temporal relationships among these 10 phases. In the cases with lower heart rates ( 65 beats/mm), they were obtained in the late systolic period. As the heart rate increased, the optimal image reconstruction phase changed from mid diastole to late systole. However, it is recommended to try to decrease the heart rate of patients before data acquisition. (author)

  14. Water as a contrast medium: a re-evaluation using the multidetector-row computed tomography.

    Science.gov (United States)

    Makarawo, Tafadzwa P; Negussie, Edsa; Malde, Sachit; Tilak, Jacqueline; Gayagoy, Jennifer; Watson, Jenna; Francis, Faiz; Lincoln, Denis; Jacobs, Michael J

    2013-07-01

    Water as an intraluminal negative contrast medium produces improved image quality with reduced artefact. However, rapid absorption of oral water in the bowel relative to speed and timing of image capturing has limited its clinical application. These findings predate advances in multidetector-row computed tomography (CT). To re-evaluate differences in image quality, we studied image clarity and luminal distention between the same group of patients who received both a pancreas protocol CT (PPCT) that uses oral water and a conventional positive oral contrast scan. We reviewed 66 patients who had previously undergone both a PPCT and an oral contrast abdominal CT. CT images were independently reviewed by two board-certified radiologists who scored degree of hollow viscus distention and visualization of mural detail using a Likert 5-point scale. Results were evaluated by using the Wilcoxon-signed rank test. Student's t test was applied to evaluate the differences in radiation dosage and Spearman's correlational test was used to evaluate interrater correlation between the radiologists. In comparing the mean radiation dosage, there was no statistical difference between the two protocols, and there was good interrater association with ratios of 0.595 and 0.51 achieved for the PPCT and conventional oral scan, respectively. The Wilcoxon signed-rank test showed statistical differences in the stomach (P contrast medium causing better or equal distention in the bowel and better or equal clarity than routine barium contrast. This calls for a need to reconsider the use of water as a contrast medium in clinical practice.

  15. Multidetector row computed tomography of acute pancreatitis: Utility of single portal phase CT scan in short-term follow up

    Energy Technology Data Exchange (ETDEWEB)

    Kwon, Yongwonn [Department of Radiology, Konkuk University Medical Center, 4-12, Hwayang-dong, Gwangjin-gu, Seoul 143-729 (Korea, Republic of); Park, Hee Sun, E-mail: heesun.park@gmail.com [Department of Radiology, Konkuk University Medical Center, 4-12, Hwayang-dong, Gwangjin-gu, Seoul 143-729 (Korea, Republic of); Kim, Young Jun; Jung, Sung Il; Jeon, Hae Jeong [Department of Radiology, Konkuk University Medical Center, 4-12, Hwayang-dong, Gwangjin-gu, Seoul 143-729 (Korea, Republic of)

    2012-08-15

    Objective: The purpose of this study is to evaluate the question of whether nonenhanced CT or contrast enhanced portal phase CT can replace multiphasic pancreas protocol CT in short term monitoring in patients with acute pancreatitis. Materials and methods: This retrospective study was approved by the Institutional Review Board. From April 2006 to May 2010, a total of 52 patients having acute pancreatitis who underwent initial dual phase multidetector row CT (unenhanced, arterial, and portal phase) at admission and a short term (within 30 days) follow up dual phase CT (mean interval 10.3 days, range 3-28 days) were included. Two abdominal radiologists performed an independent review of three sets of follow up CT images (nonenhanced scan, single portal phase scan, and dual phase scan). Interpretation of each image set was done with at least 2-week interval. Radiologists evaluated severity of acute pancreatitis with regard to pancreatic inflammation, pancreatic necrosis, and extrapancreatic complication, based on the modified CT severity index. Scores of each image set were compared using a paired t-test and interobserver agreement was evaluated using intraclass correlation coefficient statistics. Results: Mean scores of sum of CT severity index on nonenhanced scan, portal phase scan, and dual phase scan were 5.7, 6.6, and 6.5 for radiologist 1, and 5.0, 5.6, and 5.8 for radiologist 2, respectively. In both radiologists, contrast enhanced scan (portal phase scan and dual phase scan) showed significantly higher severity score compared with that of unenhanced scan (P < 0.05), while portal phase and dual phase scan showed no significant difference each other. The trend was similar regarding pancreatic inflammation and extrapancreatic complications, in which contrast enhanced scans showed significantly higher score compared with those of unenhanced scan, while no significant difference was observed between portal phase scan and dual phase scan. In pancreatic necrosis

  16. Preoperative assessment of hilar cholangiocarcinoma using multidetector-row CT. Correlation with histopathological findings

    International Nuclear Information System (INIS)

    Watadani, Takeyuki; Akahane, Masaaki; Ohtomo, Kuni; Yoshikawa, Takeharu

    2008-01-01

    Our aim was to investigate the diagnostic reliability of multidetector-row computed tomography (MDCT) for preoperative assessment of local tumoral spread in hilar cholangiocarcinoma. Thirteen of 30 consecutive patients with hilar cholangiocarcinoma who underwent surgery, excluding 17 patients who underwent biliary drainage or preoperative portal embolization, were retrospectively evaluated. Using MDCT systems of 4 detector rows or 16 detector rows, plain and dynamic contrast-enhanced images of three phases were obtained. Extent of tumor spread and lymph node metastasis were assessed with MDCT and compared with histopathological findings. The Bismuth-Corlette classification of hilar cholangiocarcinoma with MDCT were type I, 1 patient; type IIIa, 3 patients; type IIIb, 4 patients; and type IV, 5 patients; those with histopathological findings were type I, 1 patient; type IIIa, 2 patients; type IIIb, 4 patients; and type IV, 6 patients. One patient diagnosed as type IIIa with MDCT was pathologically diagnosed as type IV. Accuracy of MDCT in tumoral spread was 92.3%, although that of lymph node metastasis was 54%. MDCT is likely to play an important role in evaluation of focal lesion spread especially in intrapancreatic tumor invasion, although a greater number of cohort cases are necessary to clearly define its role. (author)

  17. Advanced Gastric Cancer: Differentiation of Borrmann Type IV versus Borrmann Type III by Two-Phased Dynamic Multi-Detector Row CT with Use of the Water Filling Method

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Dae Jung; Yu, Jeong Sik; Lee, Sang Min; Kim, Joo Hee; Chung, Jae Joon; Kim, Ki Whang [Dept. of Radiology, Yonsei University College of Medicine, Gangnam Severance Hospital, Seoul (Korea, Republic of); Kang, Hae Youn [CHA Bundang Medical Center, CHA University, Seongnam (Korea, Republic of)

    2013-02-15

    To characterize Borrmann type IV from Borrmann type III advanced gastric cancer (AGC) by two-phased multi-detector row computed tomography (MDCT) using the water filling method. A total of 143 patients (pathologically confirmed Borrmann type III and IV - 100 and 43 patients), who underwent preoperative MDCT, were enrolled. Two radiologists, retrospectively and independently, determined tumor enhancement pattern using a 5-grade scale without clinical information. A weighted kappa test was applied for interobserver variability. The score of tumor enhancement pattern correlated with Borrmann type as determined by Spearman's correlation coefficient. The accuracy of differentiation of Borrmann type using MDCT was determined by receiver operating characteristic curves. Interobserver agreement (weighted kappa = 0.683) was substantial. The tumor enhancement pattern score showed a significant correlation with Borrmann type (reviewer 1, r = 0.591, p < 0.001; reviewer 2, r = 0.616, p < 0.001). The accuracy for differentiation of Borrmann type on MDCT was 0.86 (p < 0.001) in both reviewers. The sensitivity and specificity of the diagnosis of Borrmann type IV were 79% and 82% in reviewer 1, and 88% and 78% in reviewer 2, respectively. Dual-phased MDCT using the water filling method can differentiate between Borrmann type IV and III AGC with high accuracy.

  18. Current status of multi-detector row helical CT in imaging of adult ...

    African Journals Online (AJOL)

    Current status of multi-detector row helical CT in imaging of adult acquired pancreatic diseases and assessing surgical neoplastic resectability. ... The presence of inflammation, masses, and vascular invasion was evaluated and interpreted images were obtained during each phase. Results were compared with surgery, ...

  19. Breast multidetector-row CT with histopathologic correlation

    International Nuclear Information System (INIS)

    Takeuchi, Makiko; Yamashita, Akiyoshi; Ohgi, Kazuyuki; Kobori, Kenichi; Furukawa, Takashi

    2004-01-01

    The purpose of this study was to evaluate the correlation between multidetector-row CT (MDCT) and histopathologic findings using the same MDCT image as the histopathologic cross-section. MDCT with contrast enhancement was performed in 10 patients with breast cancers (8 invasive ductal carcinomas, one invasive lobular carcinoma, and one non-invasive ductal carcinoma). We tried to reconstruct multiplanar reconstructions (MPR) in the same plane as the histopathologic cross-section, and we evaluated the histopathologic findings of the false-positive lesions. In all cases, we obtained the same MDCT image as the histopathologic cross-section. There were 10 main lesions and 18 other lesions. In the other lesions, we found no false-negative lesions and 11 false-positive lesions. False-positive lesions included periductal fibrosis, cystic change, duct papillomatosis, sclerosing adenosis, fibroadenoma, and others. Using MDCT of the breast, it is possible to obtain good correlation between CT images and histopathologic findings. MDCT is thought to be useful in the evaluation CT findings on the basis of histopathologic evidence. (author)

  20. Relationship between noise, dose, and pitch in cardiac multi-detector row CT.

    Science.gov (United States)

    Primak, Andrew N; McCollough, Cynthia H; Bruesewitz, Michael R; Zhang, Jie; Fletcher, Joel G

    2006-01-01

    In spiral computed tomography (CT), dose is always inversely proportional to pitch. However, the relationship between noise and pitch (and hence noise and dose) depends on the scanner type (single vs multi-detector row) and reconstruction mode (cardiac vs noncardiac). In single detector row spiral CT, noise is independent of pitch. Conversely, in noncardiac multi-detector row CT, noise depends on pitch because the spiral interpolation algorithm makes use of redundant data from different detector rows to decrease noise for pitch values less than 1 (and increase noise for pitch values > 1). However, in cardiac spiral CT, redundant data cannot be used because such data averaging would degrade the temporal resolution. Therefore, the behavior of noise versus pitch returns to the single detector row paradigm, with noise being independent of pitch. Consequently, since faster rotation times require lower pitch values in cardiac multi-detector row CT, dose is increased without a commensurate decrease in noise. Thus, the use of faster rotation times will improve temporal resolution, not alter noise, and increase dose. For a particular application, the higher dose resulting from faster rotation speeds should be justified by the clinical benefits of the improved temporal resolution. RSNA, 2006

  1. 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.)

  2. Impact of multi-detector row computed tomography on the tactics of cardiovascular surgery. From qualitative evaluation to quantitative assessment

    International Nuclear Information System (INIS)

    Imagawa, Hiroshi; Kawachi, Kanji; Takano, Shinji

    2005-01-01

    We assessed the role of multi-detector row computed tomography in cardiovascular surgery. The efficacy of multi-detector row computed tomography was assessed concerning the graft patency of coronary artery bypass, arterial atheromatous degeneration, small vessel imaging, and left ventricular volume measurement. Images were reconstructed using both the volume-rendering and the maximum-intensity-profile methods. Arterial atherosclerotic degeneration was assessed by aortic wall volume and aortic calcification volume. In the assessment of bypass graft patency, multidetector row computed tomography showed a 98% correct positive ratio with sensitivity and specificity of 98% and 100%, respectively. Atheromatous degeneration showed matching results in more than 70% of cases compared with intraoperative findings. More than 92% of arterial branches with diameters of 3 mm or greater were detected by preoperative multi-detector row computed tomography images, though only 6% of branches with diameters of 2 mm or less could be visualized. There was a positive linear correlation between left ventricular volumes determined by multi-detector row computed tomography and those calculated from cine angiography. Multi-detector row computed tomography clearly visualized coronary bypass grafts and aortic arterial branches, providing detailed vascular images. Atheromatous degeneration assessed by multi-detector row computed tomography was equivalent with intraoperative findings in more than 70% of cases. Left ventricular volumes measured by multi-detector row computed tomography correlated closely with those determined by cine-angiography. Multidetector row computed tomography is an efficient and promising modality in cardiovascular surgery. (author)

  3. The detectability of the origin of the inferior phrenic artery by paging method on multidetector-row CT angiography

    International Nuclear Information System (INIS)

    Terayama, Koshi

    2005-01-01

    We evaluated the ability to detect the origin of the inferior phrenic artery (IPA) by paging method on multidetector-row computed tomography (CT) angiography. In 104 patients who underwent multidetector-row CT, detectability of the origin of the IPA was assessed. In addition, in 30 patients in whom arteriographic study was performed, the IPA findings on multidetector-row CT were compared with those on arteriography. In 100 patients (96%) the origin of the right IPA was demonstrated with multidetector-row CT and in 93 patients (89%) the origin of the left IPA was demonstrated. CT angiographic findings concurred with arteriographic findings in all 30 patients (100%) who underwent arteriographic study. In conclusion, paging method on multidetector-row CT angiography provides valuable anatomical information regarding IPA. (author)

  4. Radiological emergency room management with emphasis on multidetector-row

    Energy Technology Data Exchange (ETDEWEB)

    Philipp, M.O.; Kubin, K.; Hoermann, M.; Metz, V.M. E-mail: viktor.metz@univie.ac.at

    2003-10-01

    Trauma is the fifth leading cause of death after disease of the cardiovascular system, malignomas and disease of the respiratory and digestive system. The management of severely injured patients, including radiological imaging, is a matter of ongoing development. In particular, as for the imaging modalities, multidetector-row CT represents a substantial refinement in the diagnostic work-up of multitrauma patients. Sufficient therapy within the first hour after trauma increases the patient's chances for survival significantly. Thus, therapeutic procedures and diagnostic evaluation have to be concomitant events, performed by a multidisciplinary team, namely trauma surgeon, anesthesiologist and, last but not least, radiologist. The increased performance of multidetector-row CT leads to increased spatial resolution, which is a prerequisite for sophisticated two- and three-dimensional postprocessing. The increased volume coverage speed allows for comprehensive whole-body CT at still high levels of spatial resolution, resulting in significant spare of time which influences patient's survival. Using this technique conventional imaging such as plane film or angiography may be omitted.

  5. Tuberculous Addison's disease: Morphological and quantitative evaluation with multidetector-row CT

    International Nuclear Information System (INIS)

    Ma Ensen; Yang Zhigang; Li Yuan; Guo Yingkun; Deng Yuping; Zhang Xiaochun

    2007-01-01

    Objective: To determine the characteristics of tuberculous Addison's disease on the axial and multiplanar reformatted (MPR) images of the multidetector-row computed tomography (MDCT). Materials and methods: The unenhanced and contrast-enhanced MDCT features in 19 patients with tuberculous Addison's disease were retrospectively assessed for the location, contour, size, calcification, attenuation, and enhancement patterns. The correlation between the duration of Addison's disease and the percentage of calcification presence was evaluated. Results: The adrenal glands were infected bilaterally in all of the 19 cases (100%, 38 glands). Enlargement of the glands appeared in 18 cases (94.7%, 36 glands) and the remaining one case (5.3%, two glands) showed atrophy bilaterally. Of the 36 enlarged adrenals, 13 (36.1%) had preserved contours, and the other 23 (63.9%) were mass-like. The size of the adrenals ranged from 0.6 to 4.8cm (mean 1.92+/-0.96cm). Calcification was revealed in 16 adrenals (16/38, 42.1%), increasing in incidence with disease progression. Fourteen of the 36 (38.9%) enlarged adrenals showed peripheral enhancement while the remaining 22 (61.1%) demonstrated heterogeneous enhancement. The ΔCT value, the attenuation measurement of mass-like lesions, was less in the central area (7+/-4HU) than that in the peripheral area (32+/-14HU) (P<0.01) between the unenhanced and contrast-enhanced scan. Conclusion: MDCT can reveal the characteristic morphology and CT attenuation in the tuberculous Addison's disease. Combined with its clinical presentations and biochemical findings, we can diagnose and stage adrenal tuberculosis with high specificity and accuracy on MDCT

  6. Multi-detector row CT of the head and neck: comparison of different volumes of contrast material with and without a saline chaser

    International Nuclear Information System (INIS)

    Yoon, Dae Young; You, Su Yeon; Choi, Chul Soon; Chang, Suk Ki; Yun, Eun Joo; Seo, Young Lan; Park, Sang Joon; Lee, Yu-Jin; Moon, Jeung Hee; Rho, Young-Soo; Kim, Jin-Hwan

    2006-01-01

    The aim of this study was to determine the effect of different volumes of contrast material with and without a saline chaser on tissue enhancement in multidetector row CT (MDCT) of the head and neck. In a blind prospective fashion, 120 patients were randomized into the following four groups: group 1, 80 ml contrast material administered at a flow rate of 2.0 ml/s; group 2, 80 ml followed by 40 ml saline at 2.0 ml/s; group 3, 60 ml at 1.5 ml/s; and group 4, 60 ml followed by 30 ml saline at 1.5 ml/s. The attenuation values of the carotid artery, internal jugular vein, and muscle were measured at an interval of 1.5 s in each patient. The degree of perivenous artifacts was subjectively assessed. Mean attenuation values in the carotid artery and internal jugular vein were significantly higher in groups 1 and 2 than in groups 3 and 4. The width of the diagnostic window (both carotid and jugular enhancement >150 HU) were significantly longer in groups 1 and 2 than in groups 3 and 4. The addition of a saline chaser did not result in improved vascular enhancement or a wider diagnostic window, but reduced perivenous artifacts, compared with using contrast material alone. Reduction of contrast material from 80 to 60 ml results in insufficient enhancement of neck vessels. In addition, the benefit of a saline chaser technique is not obvious except for its ability to reduce perivenous artifacts. (orig.)

  7. Usefulness of multiplanar reformatted images of multi-detector row helical CT in assessment of biliary stent patency

    International Nuclear Information System (INIS)

    Kim, Soo Jin; Kim, Suk; Kim, Chang Won; Lee, Jun Woo; Lee, Tae Hong; Choo, Ki Seok; Koo, Young Baek; Moon, Tae Yong; Lee, Suk Hong

    2004-01-01

    To evaluate the usefulness of multi-detector row helical CT (MDCT), multiplanar reformatted images for the noninvasive assessment of biliary stent patency, and for the planning for management in patients with a sele-expandable metallic stent due to malignant biliary obstruction. Among 90 consecutive patients, from August 1999 to July 2003, 26 cases in 23 patients with malignant biliary obstruction who underwent self-expandable metaIlic stent insertion in the biliary system and percutaneous transhepatic biliary drainage within 7 days after CT were enrolled in this study. On CT images, the complete and functional obstruction of the stent and the precise level of obstruction were evaluated. The presence of an enhancing intraluminal mass or wall thickening around stent was determined, and the causes of obstruction were evaluated. These findings were then compared with percutaneous transhepatic cholangiography. Multi-detector row helical CT correctly demonstrated the patency of a stent in 24 cases (92.3%). It was adequate in helping to depict the precise level of stent occlusion in 23 cases (88.5%). Multi-detector row helical CT also revealed the extent of tumor that represented as an enhancing intraluminal mass or wall thickening around the stent in 23 cases, and this was represented as complete obstruction on percutaneous transhepatic cholangiography. In the case of functional obstruction, MDCT predicted the possible cause of the obstruction. Multiplanar reformatted images of multi-detector row helical CT is a useful imaging modality for the noninvasive assessment of stent patency and the precise level of obstruction when stent obstruction is suspected in the patients with self-expandable metallic stent due to malignant biliary obstruction. It can also predict the possible cause of the obstruction and allows adequate planning for the medical management of such cases

  8. Usefulness of multiplanar reformatted images of multi-detector row helical CT in assessment of biliary stent patency

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Soo Jin; Kim, Suk; Kim, Chang Won; Lee, Jun Woo; Lee, Tae Hong; Choo, Ki Seok; Koo, Young Baek; Moon, Tae Yong; Lee, Suk Hong [Pusan National Univ. Hospital, Busan (Korea, Republic of)

    2004-08-01

    To evaluate the usefulness of multi-detector row helical CT (MDCT), multiplanar reformatted images for the noninvasive assessment of biliary stent patency, and for the planning for management in patients with a sele-expandable metallic stent due to malignant biliary obstruction. Among 90 consecutive patients, from August 1999 to July 2003, 26 cases in 23 patients with malignant biliary obstruction who underwent self-expandable metaIlic stent insertion in the biliary system and percutaneous transhepatic biliary drainage within 7 days after CT were enrolled in this study. On CT images, the complete and functional obstruction of the stent and the precise level of obstruction were evaluated. The presence of an enhancing intraluminal mass or wall thickening around stent was determined, and the causes of obstruction were evaluated. These findings were then compared with percutaneous transhepatic cholangiography. Multi-detector row helical CT correctly demonstrated the patency of a stent in 24 cases (92.3%). It was adequate in helping to depict the precise level of stent occlusion in 23 cases (88.5%). Multi-detector row helical CT also revealed the extent of tumor that represented as an enhancing intraluminal mass or wall thickening around the stent in 23 cases, and this was represented as complete obstruction on percutaneous transhepatic cholangiography. In the case of functional obstruction, MDCT predicted the possible cause of the obstruction. Multiplanar reformatted images of multi-detector row helical CT is a useful imaging modality for the noninvasive assessment of stent patency and the precise level of obstruction when stent obstruction is suspected in the patients with self-expandable metallic stent due to malignant biliary obstruction. It can also predict the possible cause of the obstruction and allows adequate planning for the medical management of such cases.

  9. Usefulness of multi-detector row Computed Tomography for ...

    African Journals Online (AJOL)

    A 74-year-old female underwent surgical treatment for adenocarcinoma of the pancreatic head. Preoperative multi-detector row computed tomography (MD-CT) demonstrated tumor invasion into the accessory right colic vein and the branch of the middle colic artery (MCA), which was not detected by digital subtraction ...

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

    International Nuclear Information System (INIS)

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

    2005-01-01

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

  11. Multidetector-row CT duodenography in familial adenomatous polyposis: a pilot study

    International Nuclear Information System (INIS)

    Taylor, S.A.; Halligan, S.; Moore, L.; Saunders, B.P.; Gallagher, M.; Phillips, R.K.S.; Bartram, C.I.

    2004-01-01

    AIM: To investigate the feasibility of using multidetector-row computed tomography (CT) duodenography to stage duodenal polyposis in patients with familial adenomatous polyposis. MATERIALS AND METHODS: Six patients underwent multidetector-row CT duodenography before upper gastrointestinal endoscopy. A single-blinded radiologist used a surface shaded three-dimensional endoluminal fly though and two-dimensional axial and multiplanar reformats to assign a score for maximum polyp size and number based on the Spigelman classification. Comparison was made with the corresponding Spigelman scores obtained from subsequent endoscopy. RESULTS: CT duodenography was technically successful in five of six patients. The CT derived Spigelman score based on maximum polyp size was accurate in all five patients. The CT derived Spigelman score based on polyp number was accurate in only two cases: Polyp number was overestimated in one patient and underestimated in a further two. In retrospect, fine carpeting of tiny duodenal polyps was poorly visualized with CT. CONCLUSIONS: CT duodenography is technically feasible and accurately predicts maximum polyp size but CT estimates of polyp number are relatively inaccurate. CT duodenography potentially has a useful role for duodenal surveillance in those patients intolerant of conventional endoscopy

  12. T-staging of gastric cancer of air-filling multidetector-row CT: Comparison with hydro-multidetector-row CT

    Energy Technology Data Exchange (ETDEWEB)

    Kumano, Seishi, E-mail: kumano@radiol.med.kindai.ac.jp [Department of Radiology, Kinki University School of Medicine, Osakasayama, Osaka 589-8511 (Japan); Okada, Masahiro; Shimono, Taro; Kuwabara, Masatomo; Yagyu, Yukinobu; Imaoka, Izumi; Ashikaga, Ryuichiro; Ishii, Kazunari; Murakami, Takamichi [Department of Radiology, Kinki University School of Medicine, Osakasayama, Osaka 589-8511 (Japan)

    2012-11-15

    Purpose: The purpose of this study was to evaluate the accuracy of T-staging of gastric cancer by air-filling multidetector-row CT (air-MDCT) compared with water-filling MDCT (hydro-MDCT). Materials and methods: One hundred fifteen patients with histologically diagnosed gastric cancer were included in this study. Fifty-eight patients underwent air-MDCT, and the remaining 57 had hydro-MDCT using a 64-channel scanner. Based on the volumetric data of contrast-enhanced MDCT obtained about 75 s after intravenously injecting 525 mg iodine per kilogram patients weight (525 mgI/kg) nonionic contrast material at the rate of 2 ml/s, oblique coronal and oblique sagittal multi-planar reformatted images perpendicular to the stomach wall, including the tumor, were reconstructed on a workstation. Mural invasion of gastric cancer into the gastric wall, as visualized by CT, was classified according to the TNM classification, and the results of T-staging by MDCT were compared with those by pathologic analysis after surgery. Results: Correct assessment of T-staging by air-CT was achieved in 48 of 58 patients (83%), and that by hydro-MDCT was 49 of 57 patients (86%). The sensitivity, specificity, and accuracy of the technique in determining the invasion of serosa were 88%, 93%, and 91% for air-CT and 83%, 95%, and 91% for hydro-CT. There were no significant differences between hydro-MDCT and air-MDCT in sensitivity (P = 0.73), specificity (P = 0.71) and accuracy (P = 0.98). Conclusion: Air-MDCT is a very valuable tool in T-staging of gastric cancer as well as hydro-MDCT.

  13. 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....

  14. 64-Slice multidetector row CT angiography of the abdomen: comparison of low versus high concentration iodinated contrast media in a porcine model

    Science.gov (United States)

    Holalkere, N-S; Matthes, K; Kalva, S P; Brugge, W R; Sahani, D V

    2011-01-01

    Objective In this study we aimed to assess the image quality and degree of vascular enhancement using low-concentration contrast media (LCCM) (300 mg I ml–1) and high-concentration contrast media (HCCM) (370 mg I ml–1) on 64-slice multidetector row CT (MDCT) abdominal CT angiography (CTA). In addition, we aimed to study the feasibility of using HCCM with a reduced total iodine dose. Methods CTA of the abdomen on a 64-slice MDCT was performed on 15 anaesthetised pigs. Study pigs were divided into three groups of five each based on the iodine concentration and dose received: Group A (LCCM; 300 mg I ml–1), Group B (HCCM; 370 mg I ml–1) and Group C HCCM with 20% less iodine dose. The total iodine injected was kept constant (600 mg kg–1) in Groups A and B. Qualitative and quantitative analyses were performed to study and compare each group for image quality, visibility of the branch order of the superior mesenteric artery (SMA), artefacts, degree of enhancement in the aorta and main stem arteries and uniformity of enhancement in the aorta. Groups were compared using the analysis of variance test. Results The image quality of 64-slice MDCT angiography was excellent with a mean score of 4.63 and confident visualisation of the third to fifth order branches of the SMA in all groups. Group B demonstrated superior vascular enhancement, as compared with Groups A and C (p≤0.05). Uniform aortic enhancement was achieved with the use of LCCM and HCCM with 20% less iodine dose. Conclusion 64-slice MDCT angiography of the abdomen was of excellent quality. HCCM improves contrast enhancement and overall CTA image quality and allows the iodine dose to be reduced. PMID:21081582

  15. Influence of gating phase selection on the image quality of coronary arteries in multidetector row computed tomography

    International Nuclear Information System (INIS)

    Laskowska, K.; Marzec, M.; Serafin, Z.; Nawrocka, E.; Lasek, W.; WWisniewska-Szmyt, J.; Kubica, J.

    2005-01-01

    Motion artifacts caused by cardiac movement disturb the imaging of coronary arteries with multidetector-row spiral computed tomography. The aim of this study was to determine the phase of the heart rate which provides the best quality of coronary artery imaging in retrospective ECG-gated CT. Although 75% is usually the best reconstruction phase, the optimal phase should be established individually for the patient, artery, segment, and type of tomograph for the best imaging quality. Forty-five cardiac CT angiograms of 26 patients were retrospectively evaluated. The examinations were performed with a 4-detector-row tomograph. ECG-gated retrospective reconstructions were relatively delayed at 0%, 12.5%, 25%, 37.5%, 50%, 62.5%, 75%, and 87.5% of the cardiac cycle. Selected coronary arteries of the highest diagnostic quality were estimated in the eight phases of the cardiac cycle. Only arteries of very high image quality were selected for analysis: left coronary artery trunks (44 cases, incl. 37 stented), anterior interventricular branches (36, incl. 3 stented), circumflex branches (16), right coronary rtery branches (23), and posterior interventricular branches (4). The reconstruction phase had a statistically significant impact on the quality of imaging (p < 0.0003). Depending on the case, optimal imaging was noted in various phases, except in the 12.5 % phase. The 75% phase appeared to be the best of all those examined (p < 0.05), both in the group of arteries without stents (p < 0.0006) and in those stented (p < 0.05). In some cases of repeated examinations the best phases differed within the same patient. (author)

  16. CT paging arteriography with a multidetector-row CT. Advantages in splanchnic arterial imaging

    Energy Technology Data Exchange (ETDEWEB)

    Kobayashi, Seiji [Keio Univ., Tokyo (Japan). School of Medicine

    1999-11-01

    The purpose of this study is to assess the utility of CT paging arteriography with a multidetector-row CT as a replacement for conventional angiography in the evaluation of splanchnic arterial anomalies. Sixty-three patients underwent CT paging arteriography with a multidetector-row CT. In the 56 patients with conventional angiographic correlation, there was only one minor disagreement with CT paging arteriography. In the 7 patients who underwent IVDSA (intra venous digital subtraction angiography), CT paging arteriography defined four hepatic arterial anomalies which could not be depicted by IVDSA. In conclusion, CT paging arteriography provides noninvasive means to identify splanchnic arterial anomalies. (author)

  17. Recent technologic advances in multi-detector row cardiac CT.

    Science.gov (United States)

    Halliburton, Sandra Simon

    2009-11-01

    Recent technical advances in multi-detector row CT have resulted in lower radiation dose, improved temporal and spatial resolution, decreased scan time, and improved tissue differentiation. Lower radiation doses have resulted from the use of pre-patient z collimators, the availability of thin-slice axial data acquisition, the increased efficiency of ECG-based tube current modulation, and the implementation of iterative reconstruction algorithms. Faster gantry rotation and the simultaneous use of two x-ray sources have led to improvements in temporal resolution, and gains in spatial resolution have been achieved through application of the flying x-ray focal-spot technique in the z-direction. Shorter scan times have resulted from the design of detector arrays with increasing numbers of detector rows and through the simultaneous use of two x-ray sources to allow higher helical pitch. Some improvement in tissue differentiation has been achieved with dual energy CT. This article discusses these recent technical advances in detail.

  18. Use of multidetector row CT with volume renderings in right lobe living liver transplantation

    International Nuclear Information System (INIS)

    Ishifuro, Minoru; Akiyama, Yuji; Kushima, Toshio; Horiguchi, Jun; Nakashige, Aya; Tamura, Akihisa; Marukawa, Kazushi; Fukuda, Hiroshi; Ono, Chiaki; Ito, Katsuhide

    2002-01-01

    Multidetector row CT is a feasible diagnostic tool in pre- and postoperative liver partial transplantation. We can assess vascular anatomy and liver parenchyma as well as volumetry, which provide useful information for both donor selection and surgical planning. Disorders of the vascular and biliary systems are carefully observed in recipients. In addition, we evaluate liver regeneration of both the donor and the recipient by serial volumetry. We present how multidetector row CT with state-of-the-art three-dimensional volume renderings may be used in right lobe liver transplantation. (orig.)

  19. The value of contrast-enhanced 64-row CT in differentiating benign from malignant serous ovarian neoplasms

    International Nuclear Information System (INIS)

    Dong Tianfa; Wu Meixian; Zhang Jiayun; Song Ting

    2009-01-01

    Objective: To assess the diagnostic value of contrast-enhanced 64-row CT scanning in deciding benign or malignant serous ovarian tumors. Methods: Fifty-eight cases of serous ovarian tumors proved pathologically were reviewed, including 25 malignant tumors, 25 benign, 8 borderline tumors. All patients underwent 64-row CT scanning, including plain scanning and contrast-enhance scanning. The tumors' shape, density, blood supply and enhancement features were evaluated. Results: Twenty-five cases of benign serous cystic adenoma were mostly unicameral, and showed a moderate mural enhancement only in 4 cases (16%) due to chronic pelvic infection and the others (21/25, 84%) had no of slight enhancement. Malignant tumors were cystic-solid mass with unclear margin, irregular shape and septa. Twenty-two cases of serous cystadenocarcinoma out of 25 cases (88%) appeared obvious enhancement and other 3 cases no enhancement. And 7 cases out of 8 (87.5%) borderlined serous cystadenomas showed different enhancement patterns. Conclusion: Benign ovarian serous neoplasms were mostly unicameral and no strong mural enhancement, suggesting a lack of blood supply. While, there were obvious enhancement in the ovarian serous cystadenocarcinoma and borderline serous cystadenoma with malignant potential. The 64-row CT is helpful for differentiating the nature of the serous ovarian neoplasm. (authors)

  20. Prevalence and Characteristics of Myocardial Bridging in Multidetector-Row Computed Tomography Coronary Angiography

    International Nuclear Information System (INIS)

    Carrascosa, Patricia; Martin Lopez, Elba; Capunay, Carlos; Deviggiano, Alejandro; Vallejos, Javier; Carrascosa, Jorge

    2009-01-01

    Background: Myocardial bridging (MB) are congenital defects of the coronary arteries in which a segment of an epicardial artery lies in the myocardium for part of its course. The current gold standard for diagnosing MB is coronary angiography; however other invasive techniques are also useful. Myocardial bridging can also be visualized with the use of novel non-invasive imaging techniques such as multidetector-row computed tomography coronary angiography (MDCT-CA). Objectives: To assess the prevalence and characteristics of myocardial bridging in patients undergoing multidetector-row computed tomography coronary angiography (MDCT-CA). Material and Methods: A total of 452 consecutive patients were evaluated with 16-row and 64-row MDCT-CA due to the presence of abnormal findings in myocardial perfusion image tests, symptoms suggestive of coronary artery disease, and in asymptomatic patients with a family history of coronary artery disease. The presence of MB, their location and characteristics were analyzed. Myocardial bridging were classified as complete and incomplete bridges with respect to continuity of the myocardium over the tunneled segment of the artery involved. Quantitative measurements of vessel diameter during systole and diastole were evaluated. Results: The prevalence of MB was 35.18%; 88 were complete and 71 incomplete. Among complete MB, 6 affected both systole and diastole, 27 presented only systolic compression and 55 showed no compression. Incomplete MB showed absence of arterial compression. Conclusions: Multidetector-row computed tomography coronary angiography detected a higher prevalence of MB in the study population and allowed to classify them and to assess their functional aspects throughout the cardiac cycle. (authors) [es

  1. Multidetector row CT for imaging the paediatric tracheobronchial tree

    International Nuclear Information System (INIS)

    Papaioannou, Georgia; Young, Carolyn; Owens, Catherine M.

    2007-01-01

    The introduction of multidetector row computed tomography (MDCT) scanners has altered the approach to imaging the paediatric thorax. In an environment where the rapid acquisition of CT data allows general hospitals to image children instead of referring them to specialist paediatric centres, it is vital that general radiologists have access to protocols appropriate for paediatric applications. Thus a dramatic reduction in the delivered radiation dose is ensured with optimal contrast bolus delivery and timing, and inappropriate repetition of the scans is avoided. This article focuses on the main principles of volumetric CT imaging that apply generically to all MDCT scanners. We describe the reconstruction techniques for imaging the paediatric thorax and the low-dose protocols used in our institution on a 16-slice detector CT scanner. Examples of the commonest clinical applications are also given. (orig.)

  2. Optimal dose and injection duration (injection rate) of contrast material for depiction of hypervascular hepatocellular carcinomas by multidetector CT

    International Nuclear Information System (INIS)

    Yanaga, Yumi; Awai, Kazuo; Nakayama, Yoshiharu; Nakaura, Takeshi; Tamura, Yoshitaka; Yamashita, Yasuyuki; Funama, Yoshinori; Aoyama, Masahito; Asada, Naoki

    2007-01-01

    The aim of this study was to investigate the optimal dose and injection duration of contrast material (CM) for depicting hypervascular hepatocellular carcinomas (HCCs) during the hepatic arterial phase with multidetector row computed tomography (CT). The study population consisted of 71 patients with hypervascular HCCs. After unenhanced scans, the first (early arterial phase, or EAP), second (late arterial phase, or LAP), and third (equilibrium phase) scanning was started at 30, 43, and 180 s after injection of contrast material (CM). During a 33-s period, patients with a body weight ≤50 kg received 100 ml of non-ionic CM with an iodine concentration of 300 mgI/ml; patients whose body weight was >50 kg received 100 ml of CM with an iodine concentration of 370 mgI/ml. First, we measured enhancement in the abdominal aorta and tumor-to-liver contrast (TLC) during the EAP and LAP. Next, to investigate the relation between aortic enhancement and TLC during the LAP, two radiologists visually assessed the conspicuity of hypervascular HCCs during the LAP using a 3-point scale: grade 1, poor; grade 2, fair; grade 3, excellent. Finally, to examine the effect of the CM dose and injection duration on aortic enhancement during the EAP, we simulated aortic enhancement curves using test bolus data obtained for 10 HCC patients and the method of Fleischmann and Hittmair. A relatively strong correlation was observed between aortic enhancement during the EAP and TLC during the LAP (correlation coefficient r=0.75, P 280 HU for aortic enhancement simulations during EAP, the injection duration should be <25 s for patients receiving a CM dose of 1.7 ml/kg with 300 mgI/ml iodine and <30 s for those receiving 2.0 ml/kg. For excellent depiction of hypervascular HCCs during the hepatic arterial phase, the injection duration should be <25 s in patients receiving a CM dose of 1.7 ml/kg with 300 mgI/ml iodine and <30 s for patients receiving 2.0 ml/kg. (author)

  3. A Comparison of the Use of Contrast Media with Different Iodine Concentrations for Multidetector CT of the Kidney

    Energy Technology Data Exchange (ETDEWEB)

    Jung, Seung Chai; Kim, Seung Hyup; Cho, Jeong Yeon [Seoul National University College of Medicine, Seoul (Korea, Republic of)

    2011-11-15

    To determine the optimal iodine concentration of contrast media for kidney multidetector computed tomography (MDCT) by comparing the degree of renal parenchymal enhancement and the severity of the renal streak artifact with contrast media of different iodine concentrations. A 16-row MDCT was performed in 15 sedated rabbits by injection of 2 mL contrast media/kg body weight at a rate of 0.3 mL/sec. Monomeric nonionic contrast media of 250, 300, and 370 mg iodine/mL were injected at 1-week intervals. Mean attenuation values were measured in each renal structure with attenuation differences among the structures. The artifact was evaluated by CT window width/level and three grading methods. The values were compared with iodine concentrations. The 370 mg iodine/mL concentration showed significantly higher cortical enhancement than 250 mg iodine/mL in all phases (p < 0.05). There was however no significant difference in the degree of enhancement between the 300 mg iodine/mL and 370 mg iodine/mL concentrations in all phases. There is a significant difference in attenuation for the cortex-outer medulla between 250 mg iodine/mL and 300 mg iodine/mL (p < 0.05). The artifact was more severe with a medium of 370 mg iodine/mL than with 250 mg iodine/mL by all grading methods (p < 0.05). The 300 mg iodine/mL is considered to be the most appropriate iodine concentration in an aspect of the enhancement and artifact on a kidney MDCT scan.

  4. Dynamic multidetector CT and non-contrast-enhanced MR for right adrenal vein imaging: comparison with catheter venography in adrenal venous sampling

    Energy Technology Data Exchange (ETDEWEB)

    Ota, Hideki; Seiji, Kazumasa; Kawabata, Masahiro; Satani, Nozomi; Matsuura, Tomonori; Tominaga, Junya; Takase, Kei [Tohoku University Hospital, Department of Diagnostic Radiology, Sendai (Japan); Omata, Kei; Ono, Yoshikiyo; Iwakura, Yoshitsugu; Morimoto, Ryo; Kudo, Masataka; Satoh, Fumitoshi; Ito, Sadayoshi [Tohoku University Hospital, Division of Nephrology, Endocrinology and Vascular Medicine, Sendai (Japan)

    2016-03-15

    To evaluate visualization of the right adrenal vein (RAV) with multidetector CT and non-contrast-enhanced MR imaging in patients with primary aldosteronism. A total of 125 patients (67 men) scheduled for adrenal venous sampling (AVS) were included. Dynamic 64-detector-row CT and balanced steady-state free precession-based non-contrast-enhanced 3-T MR imaging were performed. RAV visualization based on a four-point score was documented. Both anatomical location and variation on cross-sectional imaging were evaluated, and the findings were compared with catheter venography as the gold standard. The RAV was visualized in 93.2 % by CT and 84.8 % by MR imaging (p = 0.02). Positive predictive values of RAV visualization were 100 % for CT and 95.2 % for MR imaging. Imaging score was significantly higher in CT than MR imaging (p < 0.01). The RAV formed a common trunk with an accessory hepatic vein in 16 % of patients. The RAV orifice level on cross-sectional imaging was concordant with catheter venography within the range of 1/3 vertebral height in >70 % of subjects. Success rate of AVS was 99.2 %. Dynamic CT is a reliable way to map the RAV prior to AVS. Non-contrast-enhanced MR imaging is an alternative when there is a risk of complication from contrast media or radiation exposure. (orig.)

  5. The quality of reconstructed 3D images in multidetector-row helical CT: experimental study involving scan parameters

    International Nuclear Information System (INIS)

    Shin, Ji Hoon; Lee, Ho Kyu; Choi, Choong Gon; Suh, Dae Chul; Lim, Tae Hwan; Kang, Weechang

    2002-01-01

    To determine which multidetector-row helical CT scanning technique provides the best-quality reconstructed 3D images, and to assess differences in image quality according to the levels of the scanning parameters used. Four objects with different surfaces and contours were scanned using multidetector-row helical CT at three detector-row collimations (1.25, 2.50, 5.00 mm), two pitches (3.0, 6.0), and three different degrees of overlap between the reconstructed slices (0%, 25%, 50%). Reconstructed 3D images of the resulting 72 sets of data were produced using volumetric rendering. The 72 images were graded on a scale from 1 (worst) to 5 (best) for each of four rating criteria, giving a mean score for each criterion and an overall mean score. Statistical analysis was used to assess differences in image quality according to scanning parameter levels. The mean score for each rating criterion, and the overall mean score, varied significantly according to the scanning parameter levels used. With regard to detector-row collimation and pitch, all levels of scanning parameters gave rise to significant differences, while in the degree of overlap of reconstructed slices, there were significant differences between overlap of 0% and of 50% in all levels of scanning parameters, and between overlap of 25% and of 50% in overall accuracy and overall mean score. Among the 18 scanning sequences, the highest score (4.94) was achieved with 1.25 mm detector-row collimation, 3.0 pitch, and 50% overlap between reconstructed slices. Comparison of the quality of reconstructed 3D images obtained using multidetector-row helical CT and various scanning techniques indicated that the 1.25 mm, 3.0, 50% scanning sequence was best. Quality improved as detector-row collimation decreased; as pitch was reduced from 6.0 to 3.0; and as overlap between reconstructed slices increased

  6. CT findings of intraductal papillary neoplasm of the bile duct: Assessment with multiphase contrast-enhanced examination using multi-detector CT

    Energy Technology Data Exchange (ETDEWEB)

    Ogawa, H., E-mail: ogawa.hiroshi@h.mbox.nagoya-u.ac.jp [Department of Radiology, Nagoya University Graduate School of Medicine, Nagoya (Japan); Itoh, S. [Department of Radiology, Japanese Red Cross Nagoya Daiichi Hospital, Nagoya (Japan); Nagasaka, T. [Department of Medical Technology, Nagoya University School of Health Sciences, Nagoya (Japan); Suzuki, K. [Department of Radiology, Nagoya University Graduate School of Medicine, Nagoya (Japan); Ota, T. [Department of Radiology, Aichi Medical University Hospital, Nagakute Aichi (Japan); Naganawa, S. [Department of Radiology, Nagoya University Graduate School of Medicine, Nagoya (Japan)

    2012-03-15

    Aim: To evaluate multi-detector computed tomography (MDCT) findings of intraductal papillary neoplasm of the bile duct (IPNB), a neoplasm that is considered to be the biliary counterpart of pancreatic intraductal papillary mucinous neoplasm. Materials and methods: Two radiologists retrospectively evaluated multiphase contrast-enhanced CT images with 0.5 or 1 mm collimation in 37 consecutive patients with resected IPNB diagnosed by a single pathologist. The CT findings were correlated with the pathological findings concerning invasion of the surrounding organs and vessels. Results: All patients showed bile duct dilatation. An intraductal mass was detected in 36 patients and the following findings were observed: extensive infiltration along the bile duct more than 20 mm (n = 32), compared with normal hepatic parenchyma, isodense or hyperdense during the late arterial phase (n = 31), not hyperdense during the portal-venous and delayed phases (n = 36), and intense enhancement rim at the base of the mass during the portal-venous or delayed phase (n = 27). Parenchymal invasion of the surrounding organs was seen in eight of 16 tumours showing irregular or bulging margins. Vascular invasion was false positive in four of eight tumours. Conclusions: IPNB exhibits relatively characteristic findings with multiphase contrast-enhanced examination using MDCT. A tendency to overestimate invasion of the surrounding organs and vessels was seen.

  7. Detection, visualization and evaluation of anomalous coronary anatomy on 16-slice multidetector-row CT

    International Nuclear Information System (INIS)

    Ooijen, Peter M.A. van; Dorgelo, Joost; Oudkerk, Matthijs; Zijlstra, Felix

    2004-01-01

    Early identification and evaluation of relatively frequent anomalous coronary anatomy is quite relevant because of the occurrence of sudden cardiac death or related symptoms of myocardial ischemia. Selective coronary angiography (CAG) is invasive, expensive and cannot always provide the required information adequately. Recently, non-invasive imaging techniques such as magnetic resonance imaging and multidetector-row computed tomography (MDCT) have been shown to provide a good anatomical view of the coronary artery tree. This study aims to demonstrate the value of 16-MDCT for evaluation of anomalous coronary anatomy. In 13 patients scanned using 16-MDCT, six different coronary anomalies were diagnosed [two absent left main, one single vessel left coronary artery (LCA), three LCA originating from the right (two with interarterial course), six right coronary artery originating from the left, one double left anterior descending (LAD)]. Mean diagnostic quality, recorded by two observers using a 5-point scale (1= non-diagnostic to 5= excellent diagnostic quality), resulted in a mean score of 3.73 (SD 1.19) without any non-diagnostic result. MDCT offers an accurate diagnostic modality to visualize the origin and course of anomalous coronary arteries by a three-dimensional display of anatomy. Shortcomings in CAG can be overcome by the use of contrast-enhanced MDCT. (orig.)

  8. 16-slice multi-detector row CT coronary angiography: image quality and optimization of the image reconstruction window

    International Nuclear Information System (INIS)

    Kim, Yoo Kyung; Shim, Sung Shine; Lim, Soo Mee; Hwang, Ji Young; Kim, Yoon Kyung

    2005-01-01

    The purpose of this experiment is to investigate the image quality of CT coronary angiography using a 16-slice multi-detector row CT and to determine the optimal image reconstruction window. CT coronary angiography was obtained in 36 nonsymptomatic volunteers using a 16-slice multi-detector row CT (SOMATOM Sensation, Siemens Medical System). The mean heart rates were 70 beats per minute (bpm) or less in 18 persons and more than 70 bpm in 18 persons. Eleven data sets were obtained for each patient (reconstructed at 30%-80% of the cardiac cycle with an increment of 5%). Image quality of the eight coronary segments [left main coronary artery (LM), proximal and middle segments of left anterior descending artery (p-LAD, m-LAN) and left circumflex coronary artery (p-LCx, m-LCx) and proximal, middle and distal segments of right coronary artery (p-RCA, m-RCA, d-RCA)] was assessed. The optimal reconstruction windows in the cardiac cycle for the best image quality were 60-70% for the segments of the LM, LAD, and LC arteries in two groups (bpm 70) and 55-65% (bpm 70) for the segments of the RCA. On the best dataset for each coronary segment, the following diagnostic image quality was achieved in the two groups: LM: 100%, 83%; p-LAD: 100%, 88% m-LAD: 100%, 72%; p-LCx: 100%, 72%; m-LCx: 100%, 72%; p-RCA: 94%, 72%; m-RCA: 61%, 50%; d-RCA: 100%, 80%. The 16 slice multi-detector row CT scan provided visualization of the coronary arteries with high resolution. Especially in the group with a mean heart rate of 70 bpm or less, all the coronary segments except the RCA showed diagnostic image quality. Optimal image quality was achieved with a 60-70% trigger delay for all coronary arterial segments, but the best images of RCA were achieved in the earlier cardiac phase in the patients with a mean heart rate of more than 70 bpm

  9. Hepatic hemangioma: contrast enhancement patterns on two-phase spiral CT

    International Nuclear Information System (INIS)

    Yun, Eun Joo; Choi, Byung Ihn; Han, Joon Koo; Jang, Hyun Jung; Kim, Tae Kyoung; Kim, Ah Young; Lee, Ki Yeol

    1998-01-01

    To evaluate contrast enhancement patterns of hemangioma according to size, as seen during the arterial and portal venous phase of spiral CT. Overall, the most common enhancement pattern was peripheral high (44/82, 53.7%), during the arterial and portal venous phase. The second and third most common patterns were uniform high (11/82, 13.4%) and peripheral high-uniform high (9/82, 11.0%), also during the arterial and portal venous phase. In tumors smaller than 20 mm, low-low attenuation was seen in eight (9.8%), and iso-low attenuation in two (2.4%), during the arterial and portal venous phase, respectively. On two-phase spiral CT, the most common enhancement pattern of hemangioma was peripheral high, seen during the arterial and portal venous phase. However, a small hemangioma less than 2cm may show atypical patterns, including low and iso attenuation. (author). 23 refs., 1 tab., 4 figs

  10. Gastrointestinal tract wall visualization and distention during abdominal and pelvic multidetector CT with a neutral barium sulphate suspension: comparison with positive barium sulphate suspension and with water.

    Science.gov (United States)

    Oliva, M R; Erturk, S M; Ichikawa, T; Rocha, T; Ros, P R; Silverman, S G; Mortele, K J

    2012-01-01

    When examining patients with contrast-enhanced multidetector-row CT, we determined if the stomach and small bowel were visualized and distended better with a neutral barium sulphate suspension than with positive barium sulphate suspension or water. After obtaining approval from our institutional review board, 156 patients (women: 84; mean age: 54 yrs) with no history of gastrointestinal tract disease were randomized prospectively to receive orally either 900 ml of neutral (0.1% w/v) barium sulphate suspension (n = 53), 900 ml of positive (2.1% w/v) barium sulphate suspension (n = 53), or 900 ml of water (n = 50), prior to undergoing contrast-enhanced abdominal and pelvic multidetector-row CT. Two independent radiologists evaluated the stomach, and small bowel, for luminal distension and wall visualization, using a five point scale. Results were compared using Kruskal-Wallis and Mann-Whitney U tests. The walls of the stomach, and small bowel were visualized better in patients who were administered neutral barium sulphate suspension than those who were administered either positive barium sulphate suspension (p barium sulphate suspension, the stomach and small bowel were distended better compared to patients administered water (p barium sulphate suspension (p contrast-enhanced abdominal and pelvic multidetector-row CT, orally administered neutral barium sulphate suspension allows the gastrointestinal tract to be visualized and distended better than either positive barium sulphate suspension, or water.

  11. A Comparison of the Use of Contrast Media with Different Iodine Concentrations for Multidetector CT of the Kidney

    Science.gov (United States)

    Jung, Seung Chai; Cho, Jeong Yeon

    2011-01-01

    Objective To determine the optimal iodine concentration of contrast media for kidney multidetector computed tomography (MDCT) by comparing the degree of renal parenchymal enhancement and the severity of the renal streak artifact with contrast media of different iodine concentrations. Materials and Methods A 16-row MDCT was performed in 15 sedated rabbits by injection of 2 mL contrast media/kg body weight at a rate of 0.3 mL/sec. Monomeric nonionic contrast media of 250, 300, and 370 mg iodine/mL were injected at 1-week intervals. Mean attenuation values were measured in each renal structure with attenuation differences among the structures. The artifact was evaluated by CT window width/level and three grading methods. The values were compared with iodine concentrations. Results The 370 mg iodine/mL concentration showed significantly higher cortical enhancement than 250 mg iodine/mL in all phases (p < 0.05). There was however no significant difference in the degree of enhancement between the 300 mg iodine/mL and 370 mg iodine/mL concentrations in all phases. There is a significant difference in attenuation for the cortex-outer medulla between 250 mg iodine/mL and 300 mg iodine/mL (p < 0.05). The artifact was more severe with a medium of 370 mg iodine/mL than with 250 mg iodine/mL by all grading methods (p < 0.05). Conclusion The 300 mg iodine/mL is considered to be the most appropriate iodine concentration in an aspect of the enhancement and artifact on a kidney MDCT scan. PMID:22043154

  12. Detection of intestinal bleeding with multi-detector row CT in an experimental setup. How many acquisitions are necessary?

    International Nuclear Information System (INIS)

    Dobritz, Martin; Engels, Heinz-Peter; Bauer, Jan; Rummeny, Ernst J.; Schneider, Armin

    2009-01-01

    The purpose of the study was to evaluate multi-detector computed tomography (MDCT) acquired in different acquisitions (unenhanced, and arterial and portal venous phase following intravenous contrast medium) for detection of intestinal bleeding using an experimental bowel model. The model consisted of an injector tube with a perforation placed in a 7-m-long small bowel of a pig. The bowel was filled with water/contrast medium solution of 30-40 HU and was incorporated in a phantom model. Intestinal bleeding in different locations and bleeding velocities varying from zero to 0.75 ml/min (0.05 ml/min increments) were simulated. Twenty-six datasets in simulated unenhanced, arterial and portal venous contrast phase using increasing bleeding velocities and ten negative controls were measured using 64-row MDCT. Two radiologists blinded to the experimental settings evaluated the datasets in a random order. The likelihood of intestinal bleeding was assessed using a 5-point scale with subsequent ROC analysis. The overall sensitivity for detecting bleeding was 0.44 for an arterial acquisition alone, 0.68 for a portal venous acquisition, 0.68 for the combination unenhanced/arterial, 0.72 for unenhanced/portal venous and 0.80 for arterial/portal. Bleeding velocities of above 0.25 ml/min were detected with a sensitivity of 0.59 for arterial, 0.88 for portal venous, 0.85 for unenhanced/arterial, 0.94 for unenhanced/portal venous and 0.97 for arterial/portal venous contrast phase protocols, respectively. The specificity was 1.00. MDCT provides the highest sensitivity and specificity in the detection of intestinal bleeding using arterial and portal venous acquisition in comparison to mono-phase protocols. (orig.)

  13. Multidetector row CT angiography of living related renal donors: Is there a need for venous phase imaging?

    Energy Technology Data Exchange (ETDEWEB)

    Namasivayam, Saravanan [Department of Radiology, Division of Abdominal Imaging, Emory University School of Medicine, 1364 Clifton Road NE, Atlanta, GA 30322 (United States); Kalra, Mannudeep K. [Department of Radiology, Division of Abdominal Imaging, Emory University School of Medicine, 1364 Clifton Road NE, Atlanta, GA 30322 (United States); Waldrop, Sandra M. [Department of Radiology, Division of Abdominal Imaging, Emory University School of Medicine, 1364 Clifton Road NE, Atlanta, GA 30322 (United States); Mittal, Pardeep K. [Department of Radiology, Division of Abdominal Imaging, Emory University School of Medicine, 1364 Clifton Road NE, Atlanta, GA 30322 (United States); Small, William C. [Department of Radiology, Division of Abdominal Imaging, Emory University School of Medicine, 1364 Clifton Road NE, Atlanta, GA 30322 (United States)]. E-mail: wsmall@emory.edu

    2006-09-15

    Objective: To prospectively evaluate whether renal venous anatomy can be detected from arterial phase images of multidetector row CT (MDCT) of renal donors. Material and methods: Institutional review board approved our study protocol with waiver of consent. Forty-eight consecutive renal donors (age range, 21-56 years; M:F, 20:28) referred for MDCT evaluation were included. Two sub-specialty radiologists performed an independent and separate evaluation of renal venous anatomy in arterial and venous phase images. Opacification of renal venous structures was scored on a five-point scale (1-not seen; 3-minimal opacification; 5-excellent opacification). Arterial and venous phase opacification scores were compared by Wilcoxon signed rank test. Results: Both readers detected all renal venous anomalies in arterial as well as venous phase images. Each reader detected accessory right renal veins (n = 14), retroaortic left renal vein (n = 2), circumaortic left renal vein (n = 1), and left renal hilar arteriovenous malformation (n = 1) in arterial phase images. Retroaortic left renal venous branch was difficult to differentiate from lumbar vein (reader-1, n = 1; reader-2, n = 2) in both arterial and venous phase images. Sensitivity of detection of renal veins, left adrenal, gonadal and lumbar veins in arterial phase images was 100, 83-88, 100, and 85-90%, respectively. As expected, venous phase images showed significantly greater opacification of renal veins, left gonadal, adrenal and lumbar veins (p < .05). However, this did not substantially limit the evaluation of renal venous anatomy in arterial phase images. Both readers had substantial interobserver agreement (kappa coefficient, 0.7; p < 0.05). Conclusions: Arterial phase MDCT images alone can be used to detect renal venous anomalies, and to identify small left renal venous branches namely, the left gonadal, adrenal and lumbar veins in renal donors. Venous phase MDCT acquisition is not necessary for evaluation of renal

  14. Multidetector row CT angiography of living related renal donors: Is there a need for venous phase imaging?

    International Nuclear Information System (INIS)

    Namasivayam, Saravanan; Kalra, Mannudeep K.; Waldrop, Sandra M.; Mittal, Pardeep K.; Small, William C.

    2006-01-01

    Objective: To prospectively evaluate whether renal venous anatomy can be detected from arterial phase images of multidetector row CT (MDCT) of renal donors. Material and methods: Institutional review board approved our study protocol with waiver of consent. Forty-eight consecutive renal donors (age range, 21-56 years; M:F, 20:28) referred for MDCT evaluation were included. Two sub-specialty radiologists performed an independent and separate evaluation of renal venous anatomy in arterial and venous phase images. Opacification of renal venous structures was scored on a five-point scale (1-not seen; 3-minimal opacification; 5-excellent opacification). Arterial and venous phase opacification scores were compared by Wilcoxon signed rank test. Results: Both readers detected all renal venous anomalies in arterial as well as venous phase images. Each reader detected accessory right renal veins (n = 14), retroaortic left renal vein (n = 2), circumaortic left renal vein (n = 1), and left renal hilar arteriovenous malformation (n = 1) in arterial phase images. Retroaortic left renal venous branch was difficult to differentiate from lumbar vein (reader-1, n = 1; reader-2, n = 2) in both arterial and venous phase images. Sensitivity of detection of renal veins, left adrenal, gonadal and lumbar veins in arterial phase images was 100, 83-88, 100, and 85-90%, respectively. As expected, venous phase images showed significantly greater opacification of renal veins, left gonadal, adrenal and lumbar veins (p < .05). However, this did not substantially limit the evaluation of renal venous anatomy in arterial phase images. Both readers had substantial interobserver agreement (kappa coefficient, 0.7; p < 0.05). Conclusions: Arterial phase MDCT images alone can be used to detect renal venous anomalies, and to identify small left renal venous branches namely, the left gonadal, adrenal and lumbar veins in renal donors. Venous phase MDCT acquisition is not necessary for evaluation of renal

  15. Congenital anomalies of the coronary arteries: imaging with contrast-enhanced, multidetector computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Schmitt, Rainer; Froehner, Steffen; Wagner, Matthias; Brunner, Horst; Cherevatyy, Oleg; Christopoulos, Georgios [Herz- und Gefaessklinik GmbH, Department of Radiology, Bad Neustadt an der Saale (Germany); Brunn, Juergen; Gietzen, Frank; Kerber, Sebastian [Herz- und Gefaessklinik GmbH, Department of Cardiology, Bad Neustadt an der Saale (Germany); Fellner, Franz [Oberoesterreichische Landesnervenklinik, Department of Radiology, Linz (Austria)

    2005-06-01

    The objective of this study is to evaluate multidetector CT (MDCT) in detecting and characterizing anomalous coronary arteries. Forty-four patients with anomalies of the coronaries were selected from a total of 1758 individuals examined with ECG-gated 4- and 16-row MDCT including thin MIP, MPR and VRT post-processing. Twenty-eight patients showed origin and course anomalies of the central coronary segments, and in this subgroup 13 were judged as ''malignant'' because of interarterial courses between the aortic root and the pulmonary trunk, either of the right coronary artery (n=11) or the left coronary artery (n=2). Twelve non-hemodynamic anomalies were found, affecting the coronary origins only (n=10) or the peripheral vessels courses (n=2). Four arteriovenous fistulas were present, all of them with complex arterial feeders. Regardless of vessel anatomy, coronary opacification was always possible by means of the systemic contrast agent, and the aberrant coronary arteries were visualized synoptically in direct relation to the great mediastinal vessels. In contrast to MDCT, selective cannulation and final diagnosis was possible in only 11 of the 20 catheter angiograms performed (accuracy of 55.0%). In conclusion, its non-invasiveness and precise visualization makes MDCT the standard of reference for evaluating anomalous coronary arteries. (orig.)

  16. Multi-detector CT urography: effect of oral hydration and contrast medium volume on renal parenchymal enhancement and urinary tract opacification - a quantitative and qualitative analysis

    International Nuclear Information System (INIS)

    Szolar, Dieter H.; Tillich, Manfred; Preidler, Klaus W.

    2010-01-01

    To assess the effect of oral hydration and contrast-medium volume on renal enhancement and urinary tract opacification in multi-detector CT urography. A total of 192 patients were assigned to different protocols with varying doses of contrast agent with and without oral hydration. The attenuation was measured in the renal parenchyma in the unenhanced, nephrographic and excretory phase, and in the urinary tract in excretory phase imaging, respectively. Opacification of the urinary tract was graded on volume rendered images. Oral hydration did not significantly alter renal parenchymal enhancement in both the nephrographic and the excretory phase (p > 0.001), but significantly decreased mean attenuation of the urinary tract in the excretory phase (p ≤ 0.001), and improved continuous opacification of all ureter segments (p < 0.01). Higher volumes of contrast medium improved renal parenchymal enhancement (p ≤ 0.001) and continuous opacification of the urinary tract (p ≤ 0.01). Oral hydration leads to lower attenuation values in the urinary tract but improves the continuous opacification of the tract. Increase in contrast medium volume leads to higher renal parenchymal enhancement as well as to an increased continuous opacification of the urinary tract. Decrease in contrast medium volume cannot be compensated for by oral hydration in terms of parenchymal enhancement. (orig.)

  17. Gadolinium Ethoxybenzyl Diethylenetriamine Pentaacetic Acid (Gd-EOB-DTPA)-Enhanced Magnetic Resonance Imaging and Multidetector-Row Computed Tomography for the Diagnosis of Hepatocellular Carcinoma: A Systematic Review and Meta-analysis.

    Science.gov (United States)

    Ye, Feng; Liu, Jun; Ouyang, Han

    2015-08-01

    The purpose of this meta-analysis was to compare the diagnostic accuracy of gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid (Gd-EOB-DTPA)-enhanced magnetic resonance imaging (MRI) and multidetector-row computed tomography (MDCT) for hepatocellular carcinoma (HCC).Medline, Cochrane, EMBASE, and Google Scholar databases were searched until July 4, 2014, using combinations of the following terms: gadoxetic acid disodium, Gd-EOB-DTPA, multidetector CT, contrast-enhanced computed tomography, and magnetic resonance imaging. Inclusion criteria were as follows: confirmed diagnosis of primary HCC by histopathological examination of a biopsy specimen; comparative study of MRI using Gd-EOB-DTPA and MDCT for diagnosis of HCC; and studies that provided quantitative outcome data. The pooled sensitivity and specificity of the 2 methods were compared, and diagnostic accuracy was assessed with alternative-free response receiver-operating characteristic analysis.Nine studies were included in the meta-analysis, and a total of 1439 lesions were examined. The pooled sensitivity and specificity for 1.5T MRI were 0.95 and 0.96, respectively, for 3.0T MRI were 0.91 and 0.96, respectively, and for MDCT were 0.74 and 0.93, respectively. The pooled diagnostic odds ratio for 1.5T and 3.0T MRI was 242.96, respectively, and that of MDCT was 33.47. To summarize, Gd-EOB-DTPA-enhanced MRI (1.5T and 3.0T) has better diagnostic accuracy for HCC than MDCT.

  18. Multidetector-row CT angiography of hepatic artery: comparison with conventional angiography

    International Nuclear Information System (INIS)

    Kim, Jin Woong; Jeong, Yong Yeon; Yoon, Woong; Kim, Jae Kyu; Park, Jin Gyoon; Seo, Jeong Jin; Kang, Heoung Keun

    2003-01-01

    To determine the usefulness of three-dimensional CT angiography using multidetector-row CT (MD-CT) for delineating the arterial anatomy of the liver. Hepatic arterial three-dimensional CT angiography was performed using MDCT (lightspeed Qx/I; GE medical systems, milwaukee, Wis., U.S.A.) in 45 patients with HCC undergoing conventional angiography for transcatheter hepatic arterial chemoembolization. The scanning parameters during the early arterial phase were 2.5 mm slice thickness, 7.5 mm rotation of table speed, and a pitch of 3. Images were obtained by one radiologist using maximum intensity projection from axial CT images obtained during the early arterial phase. Two radiologists blinded to the findings of conventional angiography independently evaluated the hepatic arterial anatomy and the quality of the images obtained. Compared with conventional angiography, reader A correctly evaluated the hepatic arterial anatomy depicted at three-dimensional CT angiography. Reader B's evaluation was correct in 40 of 45 patients. Interobserver agreement was good (kappa value, 0.73), and both readers assessed the quality of three-dimensional CT angiography as excellent. Three-dimensional CT angiography using MDCT was accurate for delineating the arterial anatomy of the liver, and interobserver agreement was good. The modality may provide, prior to conventional angiography, valuable information regrading a patient's hepatic arterial anatomy

  19. Multidetector-row CT finding of gastric cystic lymphangioma: A case report

    International Nuclear Information System (INIS)

    Kang, Tae Wook; Lee, Soon Jin; Song, Hye Jong

    2008-01-01

    Cystic lymphangioma is a rare benign submucosal tumor of the stomach thought to originate from sequestered lymphatic tissue that fails to communicate with the normal lymphatic system. The most commonly used method of evaluation for cystic lymphangioma of the stomach is an endoscopic ultrasonography. We report the multidetector-row computed tomography findings of a cystic lymphangioma of the stomach in a 46-year-old man along with a literature review

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

    International Nuclear Information System (INIS)

    Romano, Luigia; Pinto, Antonio; Merola, Stefanella; Gagliardi, Nicola; Tortora, Giovanni; Scaglione, Mariano

    2008-01-01

    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

  1. Study of the renal segmental arterial anatomy with contrast-enhanced multi-detector computed tomography.

    Science.gov (United States)

    Rocco, Francesco; Cozzi, Luigi Alberto; Cozzi, Gabriele

    2015-07-01

    To use triphasic multi-detector computed tomography (MDCT) to study the renal segmental arterial anatomy and its relationship with the urinary tract to plan nephron-sparing surgery (NSS). One hundred and fifty nine patients underwent abdominal contrast-enhanced MDCT. We evaluated renal arteries and parenchymal vasculature. In 61 patients, the arteries and the urinary tract were represented simultaneously. 86.60% presented a single renal artery; 13.4%, multiple arteries. All single renal arteries divided into anterior and posterior branch before the hilum. The anterior artery branched into a superior, middle, and inferior branch. In 43.14%, the inferior artery arose before the others; in 45.75%, the superior artery arose before the others; in 9.80%, the branches shared a common trunk. In 26.80%, the posterior artery supplies the entire posterior surface; in 73.20%, it ends along the inferior calyx. In 96.73%, the upper pole was vascularized by the anterior superior branch and the posterior artery: the "tuning fork". MDCT showed four vascular segments in 96.73% and five in 3.27%. MDCT showed two avascular areas: the first along the projection of the inferior calyx on the posterior aspect, the second between the branches of the "tuning fork". The arterial phase provides the arterial tree representation; the delayed phase shows arteries and urinary tract simultaneously. MDCT provides a useful representation of the renal anatomy prior to intervascular-intrarenal NSS.

  2. Visualization of the Adamkiewicz artery in patients with acute Stanford A dissections. A prospective 64-row multi-detector CT study

    International Nuclear Information System (INIS)

    Kovacs, Attila; Willinek, W.A.; Schild, H.; Urbach, H.; Schiller, W.; Gerhards, H.M.; Welz, A.; Flacke, S.

    2009-01-01

    Purpose: to evaluate the detectability of the Adamkiewicz artery (AA) in patients with acute Stanford type A aortic dissections with multi-detector computed tomography (MDCT). Materials and Methods: 51 patients with Stanford type A dissection underwent contrast-enhanced 64-row MDCT of the entire aorta (collimation 64 x 0.625 mm; rotation time 0.4sec; 120kV; 300 mAs). The visualization of the AA, its origin, and whether it originated from the true or false lumen were analyzed using source and multiplanar reformation images. Results: a single anterior radicular artery that formed a hairpin turn constituting the anterior spinal artery was visualized in 36 (70%) patients. Thirty (83%) of these arteries originated from the left side, and 35 (97%) originated between the level T7 and L2. Twenty-three (64%) arteries originated from the true and 13 (36%) from the false lumen. Two AAs in the same patient were not observed. Conclusion: MDCT depicts the AA in a high percentage of patients with acute Stanford type A aortic dissection. (orig.)

  3. Valuation of using saline flush technique of contrast medium on abdominal multidetector row CT scanning

    International Nuclear Information System (INIS)

    Zhao Hong; Wang Ying; He Yanli; Liu Xiaobing; Bao Shiliang; Han Mingjun

    2006-01-01

    Objective: The purpose of this study was to compare the enhancement degree of abdomen organs and vessels after different amount of contrast medium using saline flush in abdomen MDCT scanning, which aimed to not affect contrast enhancement, decreased the amount of contrast medium, and reduced the side-effect. Methods: This study group consisted of 75 patients who were referred for contrast enhanced abdominal MDCT for various reasons. Patients were allocated into three groups: injection of 100ml of contrast medium only (A group), injection of 80ml pushed with 20ml of saline solution (B group), and injection of 70ml pushed with 30ml of saline solution (C group). Attenuation values were measured from the liver, spleen, pancreas, kidney, aorta, portal vein, and inferior vena cava in 33 second and 80 second of imaging after injection contrast medium. Results: The portal venous phases of the spleen, pancreas, kidney, aorta, portal vein had statistically significant difference among groups A, B and C. Post hoc test showed statistically significant difference between A group and C group, But no statistically significant difference during the portal venous phases of the pancreas and the kidney between A group and B group. Conclusion: Using a saline flush technique after the injection contrast medium in abdominal MDCT reduced waste of contrast medium and decrease in nephrotoxicity, at the same time, it would not lose important diagnostic information and saved patients cost for the contrast medium. (authors)

  4. Complications of myocardial infarction on multidetector-row computed tomography of chest

    International Nuclear Information System (INIS)

    Raj, V.; Karunasaagarar, K.; Rudd, J.H.F.; Screaton, N.; Gopalan, D.

    2010-01-01

    Myocardial infarction (MI) secondary to coronary artery disease remains the leading cause of death in the western world. The advent of early reperfusion therapy has substantially decreased in-hospital mortality and has improved the outcome in survivors of the acute phase of MI. Complications of MI include ischaemic, mechanical, arrhythmic, embolic and inflammatory disturbances. Although some of these complications may be infrequent, their importance is underscored because of the potential ability to correct them with early diagnosis and appropriate treatment. The majority of these complications will be detected on clinical examination and confirmed by echocardiography. Some patients may undergo non-electrocardiogram (ECG)-gated thoracic multidetector-row computed tomography (MDCT) due to non-specific presentation. In this group, it is imperative for the radiologist to be aware of and be confident in diagnosing the complications secondary to MI. This review illustrates the spectrum and imaging features of acute and chronic complications of MI that can be visualized on both ECG-gated cardiac and non-ECG-gated thoracic MDCT.

  5. Complications of myocardial infarction on multidetector-row computed tomography of chest

    Energy Technology Data Exchange (ETDEWEB)

    Raj, V.; Karunasaagarar, K. [Department of Radiology, Papworth and Addenbrookes Hospital, Cambridge (United Kingdom); Rudd, J.H.F. [Division of Cardiovascular Medicine, University of Cambridge, Cambridge (United Kingdom); Screaton, N. [Department of Radiology, Papworth and Addenbrookes Hospital, Cambridge (United Kingdom); Gopalan, D., E-mail: deepa.gopalan@btopenworld.co [Department of Radiology, Papworth and Addenbrookes Hospital, Cambridge (United Kingdom)

    2010-11-15

    Myocardial infarction (MI) secondary to coronary artery disease remains the leading cause of death in the western world. The advent of early reperfusion therapy has substantially decreased in-hospital mortality and has improved the outcome in survivors of the acute phase of MI. Complications of MI include ischaemic, mechanical, arrhythmic, embolic and inflammatory disturbances. Although some of these complications may be infrequent, their importance is underscored because of the potential ability to correct them with early diagnosis and appropriate treatment. The majority of these complications will be detected on clinical examination and confirmed by echocardiography. Some patients may undergo non-electrocardiogram (ECG)-gated thoracic multidetector-row computed tomography (MDCT) due to non-specific presentation. In this group, it is imperative for the radiologist to be aware of and be confident in diagnosing the complications secondary to MI. This review illustrates the spectrum and imaging features of acute and chronic complications of MI that can be visualized on both ECG-gated cardiac and non-ECG-gated thoracic MDCT.

  6. Comparison of neutral oral contrast versus positive oral contrast medium in abdominal multidetector CT

    International Nuclear Information System (INIS)

    Berther, Ralph; Eckhardt, Boris; Zollikofer, Christoph L.; Patak, Michael A.; Erturk, Sukru M.

    2008-01-01

    To determine whether neutral contrast agents with water-equivalent intraluminal attenuation can improve delineation of the bowel wall and increase overall image quality for a non-selected patient population, a neutral oral contrast agent (3% mannitol) was administered to 100 patients referred for abdominal multidetector row computed tomography (MDCT). Their results were compared with those of 100 patients given a positive oral contrast agent. Qualitative and quantitative measurements were done on different levels of the gastrointestinal tract by three experienced readers. Patients given the neutral oral contrast agent showed significant better qualitative results for bowel distension (P<0.001), homogeneity of the luminal content (P<0.001), delineation of the bowel-wall to the lumen (P<0.001) and to the mesentery (P<0.001) and artifacts (P<0.001), leading to a significant better overall image quality (P<0.001) than patients receiving positive oral contrast medium. The quantitative measurements revealed significant better distension (P<0.001) and wall to lumen delineation (P<0.001) for the patients receiving neutral oral contrast medium. The present results show that the neutral oral contrast agent (mannitol) produced better distension, better homogeneity and better delineation of the bowel wall leading to a higher overall image quality than the positive oral contrast medium in a non-selected patient population. (orig.)

  7. 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.)

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

    International Nuclear Information System (INIS)

    Cappelli, Carla; Boggi, Ugo; Mazzeo, Salvatore; Cervelli, Rosa; Contillo, Benedetta Pontillo; Bartolozzi, Carlo; Campani, Daniela; Funel, Niccola

    2015-01-01

    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.)

  9. Congenital coronary artery anomalies: diagnosis with 64 slice multidetector row computed tomography coronary angiography: A single Centre Study

    International Nuclear Information System (INIS)

    Srnivasan, K.G.; Gaikward, A.; Kannan, B.R.J.; Ritesh, K.; Ushanandini, K.P.

    2008-01-01

    Full text: Retrospective review of the congenital coronary artery (CA) anomalies detected by a 64-slice multidetector row computed tomographic (MDCT) angiography. The type of the anomaly, imaging characteristics, clinical relevance and the superiority of the MDCT over conventional coronary angiography are discussed. Multidetector row computed tomographic coronary angiography was carried out by the usual technique with 70 cc of non-ionic contrast agent and retrospective electrocardiogram gating. The volume data obtained were reconstructed in axial plane, along with volume-rendered three-dimensional reconstruction and virtual angioscopy in selected patients. The images were analysed by a radiologist, experienced in cardiac CT, and an experienced cardiologist. A retrospective review of the records was carried out, and subjects with congenital coronary anomalies were included in the study. Between 15 November 2005 and 27 February 2007, 1495 MDCT coronary angiograms were carried out. Eleven of them were found to have coronary anomalies. Five had absent left main CA. Two had interarterial course of the left main CA artery passing in between the right ventricular outflow tract and the root of aorta. In one patient, there was aberrant origin of right CA from the left aortic sinus with subsequent interarterial course and another one had aberrant origin of circumflex artery from the right aortic sinus. One patient each of congenitally absent circumflex artery and atresia of the right CA were found. Sixty-four slice MDCT coronary angiography provided accurate depiction of anomalous vessel origin and course along with the complex anatomical relation with the adjacent structures. CTcan be considered as a first-line imaging method for delineating coronary arterial anomalies.

  10. Diagnostic assessment of painless microhematuria: prospective study comparing image quality, assessibility and diagnostic certainty of multidetector-row CT and intravenous pyelography within a single examination

    International Nuclear Information System (INIS)

    Boehm, T.; John, H.; Ruedi, C.; Marincek, B.; Wildermuth, S.; Michael, M.

    2005-01-01

    Purpose: The purpose of this study is to prospectively compare intravenous pyelography (IVP) and combined unenhanced and excretory phase multidetector-row CT (MDCT) with respect to image quality, diagnostic certainty and diagnostic concordance with the final clinical diagnosis in patients with painless microhematuria. Materials and Methods: Unenhanced MDCT, IVP and excretory phase MDCT were performed in 59 consecutive patients (21 women, 38 men, mean age 56±19 years, range 23-83 years) with painless microhematuria of unknown origin during a single examination with a single contrast media application (100 ml, non-ionic iodinate contrast media). Images were assessed by two experienced urogenital radiologists in consensus for image quality, diagnostic certainty of stone detection, obstruction, parenchymal lesions and morphological distinctive features. Imaging diagnoses of MDCT and IVP were compared with the final clinical diagnoses. In case of failure to detect an relevant pathology, the final clinical diagnosis was established after a mean follow-up period of 18±6 months (10 months to 2 years). Costs and radiation exposure of IVP and MDCT were compared. Results: MDCT scan performed better than IVP in terms of image quality for all regarded variables. Image quality of MDCT was rated in all parameters as very good or good; the image quality of IVP differed in a wide range. MDCT and IVP reached a sensitivity of 100% and 50% for stone detection (n=14, p=0.008), respectively. Two bladder stones were not detected by IVU but correctly seen with MDCT. MDCT and IVP were unsatisfactory for detecting transitional cell carcinomas (n=4, 2 of 4 detected with MDCT, 0 of 4 detected with IVU). One false positive transitional cell carcinoma was detected with IVP, none with MDCT. Additional relevant pathological changes (one teratoma, one abdominal aortic aneurysma and one abscess) were detected using MDCT but missed with IVP. In 38 of 59 patients (64%) imaging and clinical follow

  11. Measurement of cardiac ventricular volumes using multidetector row computed tomography: comparison of two- and three-dimensional methods

    International Nuclear Information System (INIS)

    Montaudon, M.; Laffon, E.; Berger, P.; Corneloup, O.; Latrabe, V.; Laurent, F.

    2006-01-01

    This study compared a three-dimensional volumetric threshold-based method to a two-dimensional Simpson's rule based short-axis multiplanar method for measuring right (RV) and left ventricular (LV) volumes, stroke volumes, and ejection fraction using electrocardiography-gated multidetector computed tomography (MDCT) data sets. End-diastolic volume (EDV) and end-systolic volume (ESV) of RV and LV were measured independently and blindly by two observers from contrast-enhanced MDCT images using commercial software in 18 patients. For RV and LV the three-dimensionally calculated EDV and ESV values were smaller than those provided by two-dimensional short axis (10%, 5%, 15% and 26% differences respectively). Agreement between the two methods was found for LV (EDV/ESV: r=0.974/0.910, ICC=0.905/0.890) but not for RV (r=0.882/0.930, ICC=0.663/0.544). Measurement errors were significant only for EDV of LV using the two-dimensional method. Similar reproducibility was found for LV measurements, but the three-dimensional method provided greater reproducibility for RV measurements than the two-dimensional. The threshold value supported three-dimensional method provides reproducible cardiac ventricular volume measurements, comparable to those obtained using the short-axis Simpson based method. (orig.)

  12. Thin-section multiplanar reformats from multidetector-row CT data: Utility for assessment of regional tumor extent in non-small cell lung cancer

    International Nuclear Information System (INIS)

    Higashino, Takanori; Ohno, Yoshiharu; Takenaka, Daisuke; Watanabe, Hirokazu; Nogami, Munenobu; Ohbayashi, Chiho; Yoshimura, Masahiro; Satouchi, Miyako; Nishimura, Yoshihiro; Fujii, Masahiko; Sugimura, Kazuro

    2005-01-01

    Purpose: To determine the clinical utility of thin-section multiplanar reformats (MPRs) from multidetector-row CT (MDCT) data sets for assessing the extent of regional tumors in non-small cell lung cancer (NSCLC) patients. Materials and methods: Sixty consecutive NSCLC patients, who were considered candidates for surgical treatment, underwent contrast-enhanced MDCT examinations, surgical resection and pathological examinations. All MDCT examinations were performed with a 4-detector row computed tomography (CT). From each raw CT data set, 5 mm section thickness CT images (routine CT), 1.25 mm section thickness CT images (thin-section CT) and 1.25 mm section thickness sagittal (thin-section sagittal MPR) and coronal images (thin-section coronal MPR) were reconstructed. A 4-point visual score was used to assess mediastinal, interlobar and chest wall invasions on each image set. For assessment of utility in routine clinical practice, mean reading times for each image set were compared by means of Fisher's protected least significant difference (PLSD) test. A receiver operator characteristic (ROC) analysis was performed to determine the diagnostic capability of each of the image data sets. Finally, sensitivity, specificity and accuracy of the reconstructed images were compared by McNemar test. Results: Mean reading times for thin-section sagittal and coronal MPRs were significantly shorter than those for routine CT and thin-section CT (p < 0.05). Areas under the curve (Azs) showing interlobar invasion on thin-section sagittal and coronal MPRs were significantly larger than that on routine CT (p = 0.03), and the Az on thin-section sagittal MPR was also significantly larger than that on routine CT (p = 0.02). Accuracy of chest wall invasion by thin-section sagittal MPR was significantly higher than that by routine CT (p = 0.04). Conclusion: Thin-section multiplanar reformats from multidetector-row CT data sets are useful for assessing the extent of regional tumors in non

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

    International Nuclear Information System (INIS)

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

    2010-01-01

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

  14. Contrast-enhanced multidetector computerized tomography for odontogenic cysts and cystic-appearing tumors of the jaws: is it useful?

    Science.gov (United States)

    Kakimoto, Naoya; Chindasombatjaroen, Jira; Tomita, Seiki; Shimamoto, Hiroaki; Uchiyama, Yuka; Hasegawa, Yoko; Kishino, Mitsunobu; Murakami, Shumei; Furukawa, Souhei

    2013-01-01

    The purpose of this study was to investigate the usefulness of computerized tomography (CT), particularly contrast-enhanced CT, in differentiation of jaw cysts and cystic-appearing tumors. We retrospectively analyzed contrast-enhanced CT images of 90 patients with odontogenic jaw cysts or cystic-appearing tumors. The lesion size and CT values were measured and the short axis to long axis (S/L) ratio, contrast enhancement (CE) ratio, and standard deviation ratio were calculated. The lesion size and the S/L ratio of keratocystic odontogenic tumors were significantly different from those of radicular cysts and follicular cysts. There were no significant differences in the CE ratio among the lesions. Multidetector CT provided diagnostic information about the size of odontogenic cysts and cystic-appearing tumors of the jaws that was related to the lesion type, but showed no relation between CE ratio and the type of these lesions. Copyright © 2013 Elsevier Inc. All rights reserved.

  15. Multidetector-Row CT Findings of an Internal Supravesical Hernia: A Case Report

    International Nuclear Information System (INIS)

    Kim, Sang Won; Shin, Hyeong Cheol; Kim, Hyung Hwan; Kim, Young Tong; Kim, Il Young; Kang, Kil Ho

    2010-01-01

    A supravesical hernia occurs in the supravesical fossa and is either classified as an external or internal supravesical hernia. Most patients with internal supravesical hernias present with small bowel obstruction. Internal supravesical hernias are less common than external supravesical hernia. To date, there are few reports describing the radiological findings of supravesical hernias. To our knowledge, this is the first reported multidetector row CT (MDCT) depiction of this type of hernia. We report here on the MDCT findings of a patient with an internal supravesical hernia presenting with small bowel obstruction

  16. Multi-detector row computed tomography and blunt chest trauma

    International Nuclear Information System (INIS)

    Scaglione, Mariano; Pinto, Antonio; Pedrosa, Ivan; Sparano, Amelia; Romano, Luigia

    2008-01-01

    Blunt chest trauma is a significant source of morbidity and mortality in industrialized countries. The clinical presentation of trauma patients varies widely from one individual to another and ranges from minor reports of pain to shock. Knowledge of the mechanism of injury, the time of injury, estimates of motor vehicle accident velocity and deceleration, and evidence of associated injury to other systems are all salient features to provide for an adequate assessment of chest trauma. Multi-detector row computed tomography (MDCT) scanning and MDCT-angiography are being used more frequently in the diagnosis of patients with chest trauma. The high sensitivity of MDCT has increased the recognized spectrum of injuries. This new technology can be regarded as an extremely valuable adjunct to physical examination to recognize suspected and unsuspected blunt chest trauma

  17. Multidetector Row CT Detection of a Patent Foramen Ovale Causing Neurologic Deficits in an Adolescent: A Case Report

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jung Bin [Dept. of Radiology, Soonchunhyang University College of Medicine, Bucheon (Korea, Republic of); Kim, Dong Hun; Oh, Jae Hee [Dept. of Radiology, Chosun University College of Medicine, Gwangju (Korea, Republic of); Seo, Hye Sun [Dept. of Internal Medicine, Soonchunhyang University College of Medicine, Bucheon (Korea, Republic of); Suk, Eun Ha [Dept. of Anesthesiology and Pain Medicine, Asan Medical Center, Seoul (Korea, Republic of)

    2012-02-15

    A patent foramen ovale (PFO) is a persisting fetal circulation structural abnormality that can cause neurologic deficits such as migraine and cryptogenic stroke. Here we report a case of PFO diagnosed by cardiac multidetector row CT in an adolescent male with chronic migraine and stroke.

  18. Multidetector Row CT Detection of a Patent Foramen Ovale Causing Neurologic Deficits in an Adolescent: A Case Report

    International Nuclear Information System (INIS)

    Lee, Jung Bin; Kim, Dong Hun; Oh, Jae Hee; Seo, Hye Sun; Suk, Eun Ha

    2012-01-01

    A patent foramen ovale (PFO) is a persisting fetal circulation structural abnormality that can cause neurologic deficits such as migraine and cryptogenic stroke. Here we report a case of PFO diagnosed by cardiac multidetector row CT in an adolescent male with chronic migraine and stroke.

  19. Multidetector-row computed tomography of thoracic aortic anomalies in dogs and cats: Patent ductus arteriosus and vascular rings

    Directory of Open Access Journals (Sweden)

    Nolte Ingo

    2011-09-01

    Full Text Available Abstract Background Diagnosis of extracardiac intrathoracic vascular anomalies is of clinical importance, but remains challenging. Traditional imaging modalities, such as radiography, echocardiography, and angiography, are inherently limited by the difficulties of a 2-dimensional approach to a 3-dimensional object. We postulated that accurate characterization of malformations of the aorta would benefit from 3-dimensional assessment. Therefore, multidetector-row computed tomography (MDCT was chosen as a 3-dimensional, new, and noninvasive imaging technique. The purpose of this study was to evaluate patients with 2 common diseases of the intrathoracic aorta, either patent ductus arteriosus or vascular ring anomaly, by contrast-enhanced 64-row computed tomography. Results Electrocardiography (ECG-gated and thoracic nongated MDCT images were reviewed in identified cases of either a patent ductus arteriosus or vascular ring anomaly. Ductal size and morphology were determined in 6 dogs that underwent ECG-gated MDCT. Vascular ring anomalies were characterized in 7 dogs and 3 cats by ECG-gated MDCT or by a nongated thoracic standard protocol. Cardiac ECG-gated MDCT clearly displayed the morphology, length, and caliber of the patent ductus arteriosus in 6 affected dogs. Persistent right aortic arch was identified in 10 animals, 8 of which showed a coexisting aberrant left subclavian artery. A mild dilation of the proximal portion of the aberrant subclavian artery near its origin of the aorta was present in 4 dogs, and a diverticulum analogous to the human Kommerell's diverticulum was present in 2 cats. Conclusions Contrast-enhanced MDCT imaging of thoracic anomalies gives valuable information about the exact aortic arch configuration. Furthermore, MDCT was able to characterize the vascular branching patterns in dogs and cats with a persistent right aortic arch and the morphology and size of the patent ductus arteriosus in affected dogs. This additional

  20. Traumatic thoracic injury: the role of Multidetector-row CT

    Energy Technology Data Exchange (ETDEWEB)

    Park, Kyung Joo; Kang, Doo Kyung; Kim, Tae Hee [Ajou University School of Medicine, Suwon (Korea, Republic of)

    2006-05-15

    The introduction of Multidetector-row CT (MDCT) has revolutionized the diagnostic strategy of multitrauma patients. The rapid acquisition of a large scanning volume with a thin slice collimation allows for motion-free images of high spatial resolution, and this enables the application of the multiplanar reformat (MPR) and 3D volume-rendering (VR) images. The MPR images more accurately demonstrate aortic rupture or dissection, diaphragmatic injuries and fracture of vertebrae, sternum and costal cartilages. Diagnosing vascular injuries can be aided by using the MIP images. Rib fracture, trachea and bronchial laceration are more easily detected by the 3D images, while airway and vascular injuries can be detected from performing virtual endoscopy. We introduce our current CT imaging protocol and we present our clinical experience with using MDCT in the assessment of patients with blunt thoracic trauma.

  1. Multidetector row computed tomography in bowel obstruction. Part 2. Large bowel obstruction

    Energy Technology Data Exchange (ETDEWEB)

    Sinha, R. [Department of Radiology, Glenfield Hospital, Leicester (United Kingdom)]. E-mail: rakesh.sinha@uhl-tr.nhs.uk; Verma, R. [Department of Radiology, Glenfield Hospital, Leicester (United Kingdom)

    2005-10-01

    Large bowel obstruction may present as an emergency as high-grade colonic obstruction and can result in perforation. Perforated large bowel obstruction causes faecal peritonitis, which can result in high morbidity and mortality. Multidetector row computed tomography (MDCT) has the potential of providing an accurate diagnosis of large bowel obstruction. The rapid acquisition of images within one breath-hold reduces misregistration artefacts than can occur in critically ill or uncooperative patients. The following is a review of the various causes of large bowel obstruction with emphasis on important pathogenic factors, CT appearances and the use of multiplanar reformatted images in the diagnostic workup.

  2. Penetrating Colorectal Injuries: Diagnostic Performance of Multidetector CT with Trajectography.

    Science.gov (United States)

    Dreizin, David; Boscak, Alexis R; Anstadt, Michael J; Tirada, Nikki; Chiu, William C; Munera, Felipe; Bodanapally, Uttam K; Hornick, Michael; Stein, Deborah M

    2016-12-01

    Purpose To determine the diagnostic performance of multidetector computed tomography (CT) with trajectography for penetrating colorectal injuries. Materials and Methods This institutional review board-approved and HIPAA-compliant study was a 6-year blinded retrospective review by two independent readers of 182 consecutive patients who preoperatively underwent 40- or 64-row multidetector CT for penetrating torso trauma below the diaphragm and had surgically confirmed findings. Colorectal perforation was present in 42 patients. Trajectory analysis with postprocessing software was used for all studies. Additional signs evaluated were rectal contrast agent leak, collections of extruded fecal material, mural defect, wall thickening, abnormal enhancement, free fluid or stranding, and free air. The quality of the colorectal contrast agent administration was recorded. Sensitivity, specificity, predictive values, areas under the receiver operating characteristic curves (AUCs), and Cohen κ were determined. Results In patients with rectal contrast agent administration (n = 151), AUCs were 0.90-0.91, which indicated excellent accuracy. Trajectory was sensitive (88%-91%). For single wounds (n = 104), sensitivity of trajectory was 96% for both readers, but was only 80% for multiple wounds (n = 47). Contrast agent leak was highly specific (96%-98%), but insensitive (42%-46%). Improved diagnostic performance was observed in patients with poor colonic distension or opacification. Accuracy remained high (AUC, 0.86-0.99) in the group without rectal contrast agent administration (n = 31). Conclusion Trajectory had excellent sensitivity, while rectal contrast agent leak was specific but insensitive. Sensitivity of trajectory was lower for multiple wounds. Accuracy remained high in patients without rectal contrast agent administration. © RSNA, 2016.

  3. Imaging of peripheral arteries by 16-row multidetector computed tomography angiography: A feasible tool?

    Energy Technology Data Exchange (ETDEWEB)

    Mishra, Anuj [Department of Radiology, National Organ Transplant Program, Tripoli (Libyan Arab Jamahiriya)]. E-mail: dranujmish@yahoo.com; Bhaktarahalli, Jahnavi Narayanaswamy [Department of Clinical Pathology, Tripoli Medical Centre, Tripoli (Libyan Arab Jamahiriya); Ehtuish, Ehtuish F. [Department of Surgery, National Organ Transplant Program, Tripoli (Libyan Arab Jamahiriya)

    2007-03-15

    Objective: To evaluate the efficacy of multidetector (16-row) computed tomography (MDCT) in imaging the upper and lower limb arterial tree in trauma and peripheral arterial occlusive disease (PAOD). Methods: Thirty-three patients underwent MDCT angiography (MDCTA) of the upper or the lower limb on 16-row MDCT scanner between November, 2004 and July, 2005. The findings were compared with the surgical outcome in cases with trauma and suspected arterial injuries or color Doppler correlation was obtained for patients of PAOD. Results: MDCTA allowed a comprehensive diagnostic work-up in all trauma cases with suspected arterial injuries. In the 23 cases of PAOD, MDCT adequately demonstrated the presence of stenosis or occlusion, its degree and extent, the presence of collaterals and plaques. Conclusion: Our experience of CT angiography (CTA) with 16-row MDCT scanner has clearly demonstrated its efficacy as a promising, new, fast, accurate, safe and non-invasive imaging modality of choice in cases of trauma with suspected arterial injuries and as a useful screening modality in cases of PAOD for diagnosis and for grading.

  4. Imaging of peripheral arteries by 16-row multidetector computed tomography angiography: A feasible tool?

    International Nuclear Information System (INIS)

    Mishra, Anuj; Bhaktarahalli, Jahnavi Narayanaswamy; Ehtuish, Ehtuish F.

    2007-01-01

    Objective: To evaluate the efficacy of multidetector (16-row) computed tomography (MDCT) in imaging the upper and lower limb arterial tree in trauma and peripheral arterial occlusive disease (PAOD). Methods: Thirty-three patients underwent MDCT angiography (MDCTA) of the upper or the lower limb on 16-row MDCT scanner between November, 2004 and July, 2005. The findings were compared with the surgical outcome in cases with trauma and suspected arterial injuries or color Doppler correlation was obtained for patients of PAOD. Results: MDCTA allowed a comprehensive diagnostic work-up in all trauma cases with suspected arterial injuries. In the 23 cases of PAOD, MDCT adequately demonstrated the presence of stenosis or occlusion, its degree and extent, the presence of collaterals and plaques. Conclusion: Our experience of CT angiography (CTA) with 16-row MDCT scanner has clearly demonstrated its efficacy as a promising, new, fast, accurate, safe and non-invasive imaging modality of choice in cases of trauma with suspected arterial injuries and as a useful screening modality in cases of PAOD for diagnosis and for grading

  5. Multidetector-row computed tomography for the preoperative evaluation of axillary nodal status in patients with breast cancer

    International Nuclear Information System (INIS)

    Ogasawara, Yutaka; Doihara, Hiroyoshi; Shiraiwa, Misaki; Ishihara, Setsuko

    2008-01-01

    We evaluated the effectiveness of multidetector-row computed tomography (MD-CT) for detecting axillary lymph nodal status (ALNS) in patients with breast cancer. We reviewed 42 patients with breast cancer. A metastatic lymph node on MD-CT was defined as oval or round, with more than 5 mm on the short axis. We evaluated ALNS preoperatively by both palpation and MD-CT findings and performed sentinel lymph node biopsy (SLNB) and complete axillary lymph node dissection (ALND). For establishing the ALNS, MD-CT showed a sensitivity of 76.9%, a specificity of 96.6%, and an accuracy of 90.5%. On the basis of the MD-CT findings, misdiagnosis was made in 4 of the 42 patients, only one of which was false positive. On the other hand, one patient with a histologically negative sentinel lymph node (SLN) result had metastasis only in a non-SLN. Preoperative MD-CT showed a positive node in this patient. Multidetector-row computed tomography assists in identifying women who require ALND without SLNB, with sufficient positive predictive value. False-negative detection by SLNB could be avoided with careful interpretation of the axillary lymph nodes shown by MD-CT. (author)

  6. Rectal cancer staging: Multidetector-row computed tomography diagnostic accuracy in assessment of mesorectal fascia invasion

    Science.gov (United States)

    Ippolito, Davide; Drago, Silvia Girolama; Franzesi, Cammillo Talei; Fior, Davide; Sironi, Sandro

    2016-01-01

    AIM: To assess the diagnostic accuracy of multidetector-row computed tomography (MDCT) as compared with conventional magnetic resonance imaging (MRI), in identifying mesorectal fascia (MRF) invasion in rectal cancer patients. METHODS: Ninety-one patients with biopsy proven rectal adenocarcinoma referred for thoracic and abdominal CT staging were enrolled in this study. The contrast-enhanced MDCT scans were performed on a 256 row scanner (ICT, Philips) with the following acquisition parameters: tube voltage 120 KV, tube current 150-300 mAs. Imaging data were reviewed as axial and as multiplanar reconstructions (MPRs) images along the rectal tumor axis. MRI study, performed on 1.5 T with dedicated phased array multicoil, included multiplanar T2 and axial T1 sequences and diffusion weighted images (DWI). Axial and MPR CT images independently were compared to MRI and MRF involvement was determined. Diagnostic accuracy of both modalities was compared and statistically analyzed. RESULTS: According to MRI, the MRF was involved in 51 patients and not involved in 40 patients. DWI allowed to recognize the tumor as a focal mass with high signal intensity on high b-value images, compared with the signal of the normal adjacent rectal wall or with the lower tissue signal intensity background. The number of patients correctly staged by the native axial CT images was 71 out of 91 (41 with involved MRF; 30 with not involved MRF), while by using the MPR 80 patients were correctly staged (45 with involved MRF; 35 with not involved MRF). Local tumor staging suggested by MDCT agreed with those of MRI, obtaining for CT axial images sensitivity and specificity of 80.4% and 75%, positive predictive value (PPV) 80.4%, negative predictive value (NPV) 75% and accuracy 78%; while performing MPR the sensitivity and specificity increased to 88% and 87.5%, PPV was 90%, NPV 85.36% and accuracy 88%. MPR images showed higher diagnostic accuracy, in terms of MRF involvement, than native axial images

  7. Effect of Saline Pushing after Contrast Material Injection in Abdominal Multidetector Computed Tomography with the Use of Different Iodine Concentrations

    International Nuclear Information System (INIS)

    Tatsugami, F.; Matsuki, M.; Kani, H.; Tanikake, M.; Miyao, M.; Yoshikawa, S.; Narabayashi, I.

    2006-01-01

    Purpose: To investigate whether saline pushing after contrast material improves hepatic vascular and parenchymal enhancement, and to determine whether this technique permits decreased contrast material concentration. Material and Methods: 120 patients who underwent hepatic multidetector computed tomography were divided randomly into four groups (Groups A-D): receiving 100 ml of contrast material (300 mgI/ml) only (A) or with 50 ml of saline solution (B); or 100 ml of contrast material (350 mgI/ml) only (C) or with 50 ml of saline solution (D). Computed tomography (CT) values of the aorta in the arterial phase, the portal vein in the portal venous inflow phase, and the liver in the hepatic phase were measured. Visualization of the hepatic artery and the portal vein by 3D CT angiography was evaluated as well. Results: Although the enhancement values of the aorta were not improved significantly with saline pushing, they continued at a high level to the latter slices with saline pushing. The enhancement value of the portal vein increased significantly and CT portography was improved with saline pushing. The enhancement value of the liver was not improved significantly using saline pushing. In a comparison between groups B and C, the enhancement values of the aorta and portal vein and the visualization of CT arteriography and portography were not statistically different. Conclusion: The saline pushing technique can contribute to a decrease in contrast material concentration for 3D CT arteriography and portography

  8. Multidetector row computed tomography noninvasively assesses coronary reperfusion after thrombolytic therapy in patients with ST elevation myocardial infarction

    International Nuclear Information System (INIS)

    Shin, Dong-Il; Won, Yoo-Dong; Chang, Kiyuk

    2006-01-01

    The study objective was to assess the efficacy of 16-slice multidetector row computed tomography (MDCT) in estimating residual stenosis and successful reperfusion after thrombolysis in patients with ST-elevation myocardial infarction (STEMI). A total of 31 patients with STEMI underwent MDCT scanning within 6 h (mean 4.6±1.1) after thrombolysis and the results for detection of significant residual stenosis and distal flow of the infarct-related artery were compared with those from conventional coronary angiography (CCAG) performed within 24 h (mean 12.1±5.6) after the MDCT scan. Successful reperfusion was defined as Thrombolysis In Myocardial Infarction flow 2 or 3 on CCAG and full contrast enhancement of the distal artery landmarks on MDCT. A final analysis was performed using 24 patients (312 segments). MDCT had a positive predictive value of 73.3% and a negative predictive value of 95.1% for detecting significant residual stenosis. It accurately estimated 17 of 18 patients (94.4%) with successful reperfusion and 5 of 6 (83.3%) with failed reperfusion on the basis of comparison with CCAG. MDCT demonstrated high accuracy not only for the detecting residual stenosis, but also for assessing successful reperfusion after thrombolytic therapy in patients with STEMI. (author)

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

    Science.gov (United States)

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

    2010-05-20

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

  10. The value of multidetector-row computed tomography for localization of obscure acute gastrointestinal bleeding

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Wei-Chou [Department of Radiology, Tri-Service General Hospital, National Defense Medical Center, Taiwan (China); Tsai, Shih-Hung [Department of Emergency Medicine, Tri-Service General Hospital, National Defense Medical Center, Taiwan (China); Chang, Wei-Kuo [Division of Gasteroenterology, Department of Internal Medicine, Tri-Service General Hospital, National Defense Medical Center, Taiwan (China); Liu, Chang-Hsien [Department of Radiology, Tri-Service General Hospital, National Defense Medical Center, Taiwan (China); Tung, Ho-Jui [Department of Healthcare Administration, Asia University, Taichung, Taiwan (China); Hsieh, Chung-Bao [Department of Surgery, Tri-Service General Hospital, National Defense Medical Center, Taiwan (China); Huang, Guo-Shu; Hsu, Hsian-He [Department of Radiology, Tri-Service General Hospital, National Defense Medical Center, Taiwan (China); Yu, Chih-Yung, E-mail: chougo2002@yahoo.com.tw [Department of Radiology, Tri-Service General Hospital, National Defense Medical Center, Taiwan (China)

    2011-11-15

    Purpose: There are no simple guidelines on when to perform multidetector-row computed tomography (MDCT) for diagnosis of obscure acute gastrointestinal bleeding (AGIB). We used a risk scoring system to evaluate the diagnostic power of MDCT for patients with obscure AGIB. Materials and methods: Ninety-two patients with obscure AGIB who were referred for an MDCT scan after unsuccessful endoscopic treatment at presentation were studied. We recorded clinical data and calculated Blatchford score for each patient. Patients who required transfusion more than 500 mL of blood to maintain the vital signs were classified as high-risk patients. Two radiologists independently reviewed and categorized MDCT signs of obscure AGIB. Discordant findings were resolved by consensus. One-way ANOVA was used to compare clinical data between two groups; kappa statistics were used to estimate agreement on MDCT findings between radiologists. Results: Of the 92 patients, 62 (67.4%) were classified as high-risk patients. Blatchford scores of high-risk patients were significantly greater than those of low-risk patients. Sensitivity for MDCT diagnosing obscure AGIB was 81% in high-risk patients, as compared with 50% in the low-risk. When used in conjunction with selection of the cut-off value of 13 in Blatchford scoring system, the sensitivity and specificity of MDCT were 70.9% and 73.7%, respectively. Contrast extravasation was the most specific sign of AGIB (k = .87), recognition of which would have improved diagnostic accuracy. Conclusions: With the aid of Blatchford scoring system for evaluating the disease severity, MDCT can localize the bleeders of obscure AGIB more efficiently.

  11. The value of multidetector-row computed tomography for localization of obscure acute gastrointestinal bleeding

    International Nuclear Information System (INIS)

    Chang, Wei-Chou; Tsai, Shih-Hung; Chang, Wei-Kuo; Liu, Chang-Hsien; Tung, Ho-Jui; Hsieh, Chung-Bao; Huang, Guo-Shu; Hsu, Hsian-He; Yu, Chih-Yung

    2011-01-01

    Purpose: There are no simple guidelines on when to perform multidetector-row computed tomography (MDCT) for diagnosis of obscure acute gastrointestinal bleeding (AGIB). We used a risk scoring system to evaluate the diagnostic power of MDCT for patients with obscure AGIB. Materials and methods: Ninety-two patients with obscure AGIB who were referred for an MDCT scan after unsuccessful endoscopic treatment at presentation were studied. We recorded clinical data and calculated Blatchford score for each patient. Patients who required transfusion more than 500 mL of blood to maintain the vital signs were classified as high-risk patients. Two radiologists independently reviewed and categorized MDCT signs of obscure AGIB. Discordant findings were resolved by consensus. One-way ANOVA was used to compare clinical data between two groups; kappa statistics were used to estimate agreement on MDCT findings between radiologists. Results: Of the 92 patients, 62 (67.4%) were classified as high-risk patients. Blatchford scores of high-risk patients were significantly greater than those of low-risk patients. Sensitivity for MDCT diagnosing obscure AGIB was 81% in high-risk patients, as compared with 50% in the low-risk. When used in conjunction with selection of the cut-off value of 13 in Blatchford scoring system, the sensitivity and specificity of MDCT were 70.9% and 73.7%, respectively. Contrast extravasation was the most specific sign of AGIB (k = .87), recognition of which would have improved diagnostic accuracy. Conclusions: With the aid of Blatchford scoring system for evaluating the disease severity, MDCT can localize the bleeders of obscure AGIB more efficiently.

  12. Accessory Renal Artery Stenosis and Hypertension: Are These Correlated? Evaluation Using Multidetector-Row Computed Tomographic Angiography

    Energy Technology Data Exchange (ETDEWEB)

    Saba, L.; Sanfilippo, R.; Montisci, R.; Conti, M.; Mallarini, G. (Dept. of Imaging Science and Dept. of Vascular Surgery, Policlinico Universitario, Cagliari (Italy))

    2008-04-15

    Background: Renal artery stenosis may produce hypertension, and this condition is referred to as renovascular hypertension (RVH). Purpose: To evaluate, by using multidetector-row spiral computed tomographic angiography (MDCTA), whether a relationship between accessory renal artery stenosis and hypertension may be hypothesized. Material and Methods: 214 patients (142 males, 72 females; mean age 66 years) who had previously undergone an MDCTA to study the abdominal vasculature were retrospectively studied. Patients with renal artery stenosis (RAS) were excluded from this analysis. The patients were studied by means of a four-detector-row CT, and scans were obtained after intravenous bolus administration of 110-140 ml of a nonionic contrast material with a 3-6 ml/s flow rate. As a second step, by means of statistical analysis, hypertension data were compared with findings of accessory artery stenosis. Two radiologists first independently reviewed the MDCTA images and then, in case of disagreement, in consensus. Interobserver agreement was calculated for all measurements. Results: The overall number of detected accessory renal arteries was 74 in 56 of the 214 patients. Accessory renal artery stenosis was detected in 21 of the 56 patients. There was a difference in the prevalence of hypertension between patients with (n = 21) and without (n = 35) accessory renal artery stenosis (P = 0.0187). Interobserver agreement was good (kappa value 0.733). Conclusion: Any statistical association between the presence of accessory renal artery stenosis and hypertension could not be disclosed. However, accessory renal artery stenosis, detected by MDCTA, is an important pathological sign that the radiologist has to assess in the light of its possible association with hypertension

  13. Accessory Renal Artery Stenosis and Hypertension: Are These Correlated? Evaluation Using Multidetector-Row Computed Tomographic Angiography

    International Nuclear Information System (INIS)

    Saba, L.; Sanfilippo, R.; Montisci, R.; Conti, M.; Mallarini, G.

    2008-01-01

    Background: Renal artery stenosis may produce hypertension, and this condition is referred to as renovascular hypertension (RVH). Purpose: To evaluate, by using multidetector-row spiral computed tomographic angiography (MDCTA), whether a relationship between accessory renal artery stenosis and hypertension may be hypothesized. Material and Methods: 214 patients (142 males, 72 females; mean age 66 years) who had previously undergone an MDCTA to study the abdominal vasculature were retrospectively studied. Patients with renal artery stenosis (RAS) were excluded from this analysis. The patients were studied by means of a four-detector-row CT, and scans were obtained after intravenous bolus administration of 110-140 ml of a nonionic contrast material with a 3-6 ml/s flow rate. As a second step, by means of statistical analysis, hypertension data were compared with findings of accessory artery stenosis. Two radiologists first independently reviewed the MDCTA images and then, in case of disagreement, in consensus. Interobserver agreement was calculated for all measurements. Results: The overall number of detected accessory renal arteries was 74 in 56 of the 214 patients. Accessory renal artery stenosis was detected in 21 of the 56 patients. There was a difference in the prevalence of hypertension between patients with (n = 21) and without (n = 35) accessory renal artery stenosis (P = 0.0187). Interobserver agreement was good (kappa value 0.733). Conclusion: Any statistical association between the presence of accessory renal artery stenosis and hypertension could not be disclosed. However, accessory renal artery stenosis, detected by MDCTA, is an important pathological sign that the radiologist has to assess in the light of its possible association with hypertension

  14. Efficacy of double arterial phase dynamic magnetic resonance imaging with the sensitivity encoding technique versus dynamic multidetector-row helical computed tomography for detecting hypervascular hepatocellular carcinoma

    International Nuclear Information System (INIS)

    Kumano, Seishi; Okada, Masahiro; Murakami, Takamichi; Uemura, Masahiko; Haraikawa, Toyoaki; Hirata, Masaaki; Kikuchi, Keiichi; Mochizuki, Teruhito; Kim, Tonsok

    2009-01-01

    The aim of this study was to evaluate the efficacy of double arterial phase dynamic magnetic resonance imaging (MRI) with the sensitivity encoding technique (SENSE dynamic MRI) for detection of hypervascular hepatocellular carcinoma (HCC) in comparison with double arterial phase dynamic multidetector-row helical computed tomography (dynamic MDCT). A total of 28 patients with 66 hypervascular HCCs underwent both double arterial SENSE dynamic MRI and dynamic MDCT. The diagnosis of HCC was based on surgical resection (n=7), biopsy (n=10), or a combination of CT during arterial portography (CTAP), CT during hepatic arteriography (CTA), and/or the 6-month follow-up CT (n=49). Based on alternative-free response receiving operating characteristic (ROC) analysis, the diagnostic performance for detecting HCC was compared between double arterial phase SENSE dynamic MRI and double arterial phase dynamic MDCT. The mean sensitivity, positive predictive value, and mean A Z values for hypervascular HCCs were 72%, 80%, and 0.79, respectively, for SENSE dynamic MRI and 66%, 92%, and 0.78, respectively, for dynamic MDCT. The mean sensitivity for double arterial phase SENSE dynamic MRI was higher than that for double arterial phase dynamic MDCT, but the difference was not statistically significant. Double arterial phase SENSE dynamic MRI is as valuable as double arterial phase dynamic MDCT for detecting hypervascular HCCs. (author)

  15. Subtraction MR venography acquired from time-resolved contrast-enhanced MR angiography: Comparison with phase-contrast MR venography and single-phase contrast-enhanced MR venography

    International Nuclear Information System (INIS)

    Jang, Jin Hee; Kim, Bum Soo; KIm, Bom Yi; Choi, Hyun Seok; Jung, So Lyung; Ahn, Kook Jin; Sung, Ji Kyeong

    2015-01-01

    To evaluate the image characteristics of subtraction magnetic resonance venography (SMRV) from time-resolved contrast-enhanced MR angiography (TRMRA) compared with phase-contrast MR venography (PCMRV) and single-phase contrast-enhanced MR venography (CEMRV). Twenty-one patients who underwent brain MR venography (MRV) using standard protocols (PCMRV, CEMRV, and TRMRA) were included. SMRV was made by subtracting the arterial phase data from the venous phase data in TRMRA. Co-registration and subtraction of the two volume data was done using commercially available software. Image quality and the degree of arterial contamination of the three MRVs were compared. In the three MRVs, 19 pre-defined venous structures (14 dural sinuses and 5 cerebral veins) were evaluated. The signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) of the three MRVs were also compared. Single-phase contrast-enhanced MR venography showed better image quality (median score 4 in both reviewers) than did the other two MRVs (p < 0.001), whereas SMRV (median score 3 in both reviewers) and PCMRV (median score 3 in both reviewers) had similar image quality (p ≥ 0.951). SMRV (median score 0 in both reviewers) suppressed arterial signal better than did the other MRVs (median score 1 in CEMRV, median score 2 in PCMRV, both reviewers) (p < 0.001). The dural sinus score of SMRV (median and interquartile range [IQR] 48, 43-50 for reviewer 1, 47, 43-49 for reviewer 2) was significantly higher than for PCMRV (median and IQR 31, 25-34 for reviewer 1, 30, 23-32 for reviewer 2) (p < 0.01) and did not differ from that of CEMRV (median and IQR 50, 47-52 for reviewer 1, 49, 45-51 for reviewer 2) (p = 0.146 in reviewer 1 and 0.123 in reviewer 2). The SNR and CNR of SMRV (median and IQR 104.5, 83.1-121.2 and 104.1, 74.9-120.5, respectively) were between those of CEMRV (median and IQR 150.3, 111-182.6 and 148.4, 108-178.2) and PCMRV (median and IQR 59.4, 49.2-74.9 and 53.6, 43.8-69.2). Subtraction magnetic

  16. Hereditary haemorrhagic telangiectasia: study of hepatic vascular alterations with multi-detector row helical CT and reconstruction programs

    International Nuclear Information System (INIS)

    Memeo, Maurizio; Stabile Ianora, Amato Antonio; Scaldapane, Arnaldo; Rotondo, Antonio; Angelelli, Giuseppe; Suppressa, Patrizia; Cirulli, Anna; Sabba', Carlo

    2005-01-01

    Purpose: To evaluate hepatic alterations in patients affected by Hereditary Haemorrhagic Telangiectasia (HHT) by using multidetector row helical CT (MDCT) and new reconstruction programs. Materials and methods: An MDCT multiphasic study of the liver was performed in 105 consecutive patients: 89 considered to be affected by HHT and 16 with suspicion of disease alone. The scan delay was determined by using a test bolus of contrast material. The CT examination was performed with a triphasic technique (double arterial phase and portal venous phase). multiplanar and angiographic reconstructions were then obtained, and the images checked for the presence of shunts, hepatic perfusion disorders, vascular lesions (telangiectasis and large confluent vascular masses), indirect signs of portal hypertension, and anatomical vascular variants. Results: Hepatic vascular alterations were found in 78/105 cases (67/89) patients affected by HHT and 11/16 patients with clinical suspicion alone). Therefore HHT diagnosis was excluded in 5 patients. 78/100 (78%) patients with HHT had intrahepatic vascular alterations: arterioportal shunts in 40/78 (51.2%) arteriosystemic shunts in 16/78 (20.5%) and both shunt types in 22/78 (28.3%). Intraparenchymal perfusion disorders were found in 46/78 (58.9%) patients. Telangiectasis were recognised in 50/78 (64.1%) patients. Large confluent vascular masses (LCVMs) were identified in 20/78 (25.6%) patients. indirect signs of portal hypertension were found in 46/78 (58.9%) cases. Variant hepatic arterial anatomy was present in 38/100 cases (38%). Conclusions: Multiphasic MDCT and the new reconstruction programs enable the identification and characterisation of the complex vascular alterations typical of HHT [it

  17. Dynamic contrast-enhanced CT appearances of the intraductal papillary neoplasms of the bile duct

    International Nuclear Information System (INIS)

    Song Fengxiang; Zhou Jianjun; Zeng Mengsu; Zhou Kangrong; Ding Yuqin; He Deming; Shi Yuxin; Zhou Jun

    2013-01-01

    Objective: To analyze the dynamic contrast-enhanced CT appearances of intraductal papillary neoplasms of the bile duct and improve its diagnostic accuracy. Methods: Sixteen patients with intraductal papillary neoplasms of the bile duct confirmed histopathologically after surgical operation underwent dynamic contrast-enhanced multi-detector row CT scans. All imaging data were reviewed and analyzed retrospectively in correlation with surgical and pathological findings. CT values of 38 well-visualized lesions in 12 of the 16 patients at the pre-contrast phase, arterial phase and venous phase were measured. Four of the 12 patients with 17 lesions had benign tumors, and 8 of the 12 patients with 21 lesions had malignant tumors. Comparisons of CT values at the three phases between the two groups were carried out using independent sample t test. The bile CT values were measured in these 12 cases, 40 normal volunteers, and 40 subjects with bile duct stones, and the Wilcoxon signed-rank test was applied to compare the bile CT values between tumor group and the normal group and between tumor group and the bile duct stone group. The diameters of the bile ducts proximal to and distal to tumors were also measured, and Fisher exact method was carried to analyze the data. Results: Lesions located at the left lobe in 8 out of the 16 patients, the right lobe in 1 case, both the left and right lobes in 1 case, the hepatic hilum in 1 case, the common bile duct in 3 cases, and both the right lobe and the common bile duct in 2 cases. Eleven lesions appeared as papillary masses, 3 as flat masses, 1 as mixed papillary and flat masses. In one case, tumor mass could not be definitely visualized, and only dilated bile ducts and stones were demonstrated. The mean CT values of the benign tumors were (25.8 ± 8.0), (37.7 ± 10.3) and (51.7 ± 17.1) HU respectively at pre-contrast phase, arterial phase, and venous phase, and the malignant tumors were (38.4 ± 10.2), (56.6 ± 18.0) and (68.4

  18. 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.

  19. Using multidetector-row CT in neonates with complex congenital heart disease to replace diagnostic cardiac catheterization for anatomical investigation: initial experiences in technical and clinical feasibility

    International Nuclear Information System (INIS)

    Lee, Tain; Tsai, I.C.; Chen, Min-Chi; Fu, Yun-Ching; Jan, Sheng-Lin; Wang, Chung-Chi; Chang, Yen

    2006-01-01

    Echocardiography is the first-line modality for the investigation of neonatal congenital heart disease. Diagnostic cardiac catheterization, which has a small but recognized risk, is usually performed if echocardiography fails to provide a confident evaluation of the lesions. To verify the technical and clinical feasibilities of replacing diagnostic cardiac catheterization with multidetector-row CT (MDCT) in neonatal complex congenital heart disease. Over a 1-year period we prospectively enrolled all neonates with complex congenital heart disease referred for diagnostic cardiac catheterization after initial assessment by echocardiography. MDCT was performed using a 40-detector-row CT scanner with dual syringe injection. A multidisciplinary congenital heart disease team evaluated the MDCT images and decided if further diagnostic cardiac catheterization was necessary. The accuracy of MDCT in detecting separate cardiovascular anomalies and bolus geometry of contrast enhancement were calculated. A total of 14 neonates were included in the study. No further diagnostic cardiac catheterization was needed in any neonate. The accuracy of MDCT in diagnosing separate cardiovascular anomalies was 98% (53/54) with only one atrial septal defect missed in a patient with coarctation syndrome. The average cardiovascular enhancement in evaluated chambers was 471 HU. No obvious beam-hardening artefact was observed. The technical and clinical feasibility of MDCT in complex congenital heart disease in neonates is confirmed. After initial assessment with echocardiography, MDCT could probably replace diagnostic cardiac catheterization for further anatomical clarification in neonates. (orig.)

  20. Liver imaging with MDCT and high concentration contrast media

    International Nuclear Information System (INIS)

    Spielmann, Audrey L.

    2003-01-01

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

  1. Hypervascular hepatocellular carcinomas: detection with gadoxetate disodium-enhanced MR imaging and multiphasic multidetector CT

    Energy Technology Data Exchange (ETDEWEB)

    Onishi, Hiromitsu; Kim, Tonsok; Hori, Masatoshi; Nakaya, Yasuhiro; Tsuboyama, Takahiro; Nakamoto, Atsushi; Tatsumi, Mitsuaki; Tomiyama, Noriyuki [Osaka University Graduate School of Medicine, Department of Radiology, Suita, Osaka (Japan); Imai, Yasuharu [Ikeda Municipal Hospital, Department of Gastroenterology, Ikeda, Osaka (Japan); Nagano, Hiroaki [Osaka University Graduate School of Medicine, Department of Surgery, Suita, Osaka (Japan); Kumano, Seishi; Okada, Masahiro; Murakami, Takamichi [Kinki University School of Medicine, Department of Radiology, Osakasayama, Osaka (Japan); Takamura, Manabu [Ikeda Municipal Hospital, Department of Radiology, Ikeda, Osaka (Japan); Wakasa, Kenichi [Osaka City University Graduate School of Medicine, Department of Diagnostic Pathology, Osaka, Osaka (Japan)

    2012-04-15

    To retrospectively compare the accuracy of detection of hypervascular hepatocellular carcinoma (HCC) by multiphasic multidetector CT and by gadoxetate disodium-enhanced MR imaging. After ethical approval, we analysed a total of 73 hypervascular HCC lesions from 31 patients suspected of having HCC, who underwent both gadoxetate disodium-enhanced MR imaging and multiphasic multidetector CT. Five blinded observers independently reviewed CT images, as well as dynamic MR images alone and combined with hepatobiliary phase MR images. Diagnostic accuracy (Az values), sensitivities and positive predictive values were compared by using the Scheffe post hoc test. The mean Az value for dynamic and hepatobiliary phase MR combined (0.81) or dynamic MR images alone (0.78) was significantly higher than that for CT images (0.67, P < 0.001, 0.005, respectively). The mean sensitivity of the combined MR images (0.67) was significantly higher than that of dynamic MR alone (0.52, P < 0.05) or CT images (0.44, P < 0.05). The mean positive predictive values were 0.96, 0.95 and 0.94, for CT, dynamic MR alone and combined MR images, respectively. Compared with multiphasic multidetector CT, gadoxetate disodium-enhanced MR imaging combining dynamic and hepatobiliary phase images results in significantly improved sensitivity and diagnostic accuracy for detection of hypervascular HCC. (orig.)

  2. Evaluation of left ventricular function and volume with multidetector-row computed tomography. Comparison with electrocardiogram-gated single photon emission computed tomography

    International Nuclear Information System (INIS)

    Suzuki, Takeya; Yamashina, Shohei; Nanjou, Shuji; Yamazaki, Junichi

    2007-01-01

    This study compared left ventricular systolic function and volume determined by multidetector-row computed tomography (MDCT) and electrocardiogram-gated single photon emission computed tomography (G-SPECT) Thirty-seven patients with coronary artery disease and non-cardiovascular disease underwent MDCT. In this study, left ventricular ejection fraction (EF), left ventricular end-diastolic volume (EDV) and left ventricular end-systolic volume (ESV) were calculated using only two-phase imaging with MDCT. Left ventricular function and volume were compared using measurements from G-SPECT. We conducted MDCT and G-SPECT virtually simultaneously. Both the EF and ESV evaluated by MDCT closely correlated with G-SPECT (r=0.763, P 65 bpm) during MDCT significantly influenced the difference in EF calculated from MDCT and G-SPECT (P<0.05). Left ventricular function can be measured with MDCT as well as G-SPECT. However, a heart rate over 65 bpm during MDCT negatively affects the EF correlation between MDCT and G-SPECT. (author)

  3. Prevalence of extra-cardiac findings on studies of noninvasive coronary angiography multidetector computed tomography 64 rows

    International Nuclear Information System (INIS)

    Carrascosa, Patricia M.; Capunay, Carlos M.; Deviggiano, A.; Melendez, F.; Carrascosa, Jorge M.; Garcia, M.

    2007-01-01

    The aim of this paper is to show the importance of evaluating in a full form images obtained from a studio of noninvasive coronary angiography by multidetector computed tomography (AC-TCMD). 90 users of AC-TCMD were evaluated retrospectively conducted between October 2006 and April 2007 with a multidetector tomography of 64-rows(Phillips Medical Systems) . The images were reprocessed with a maximum field of vision and determined the presence of extra-cardiac findings, which were classified according to their impact on the management and treatment of patient at 3 degrees: low, medium and high grade. The studies were assessed jointly by a cardiologist and a radiologist qualified for cardiac and corporal evaluation. Extra-cardiac findings were identified in 58 patients. There were 38 patients with findings of low grade, 31 medium grade and 1 high grade. It was recommended to 16 patients its monitoring by images on reasonable period of time [es

  4. Clinico-statistical study of preoperative examination for the dental implant using multi-detector row computed tomography

    International Nuclear Information System (INIS)

    Sekiya, Keiko; Mori, Shintaro; Sekiya, Kotaro

    2008-01-01

    In April 2006, a new affiliated hospital opened at Nihon University School of Dentistry at Matsudo, and the latest model was introduced into the department of radiology. CT examinations for preoperative dental implant going on 64 multi-detector row CT, the number of cases has increased. CT examination is useful for preoperative dental implant, and many studies of concerning clinical studies using CT images have been reported. The purpose of this study was to the clinico-statistical studies of preoperative CT examinations for dental implant at our radiology department using 64 multi-detector row CT. The subjects consisted of 5174 regions in 1312 cases of preoperative CT examinations, between April 2006 and December 2007. CT machine used was the Aquilion TM 64 (Toshiba Medical Systems, Japan), and the workstation used was the ZIOSTATION (ZIOSOFT, Japan). All of CT examinations were performed the position of implant placement and disease examined from CT findings. The following results were obtained: The 1312 cases consisted of 426 males and 886 females. Patient age ranged from 16 yrs to 86 yrs old, the average age were 55.5 yrs old. Six hundred and seventy four cases were ordered at another private dental office not our hospital, and 638 cases were ordered at our hospital. The numbers of implant placement were on the average of 3.9, and the rate got higher with age. The lesions which detected by preoperative CT examination were maxillary sinusitis, periodontitis, ectopic calcification, and mucous retention cyst. (author)

  5. Detection and localization of acute upper and lower gastrointestinal (GI) bleeding with arterial phase multi-detector row helical CT

    Energy Technology Data Exchange (ETDEWEB)

    Jaeckle, T.; Stuber, G.; Hoffmann, M.H.K.; Jeltsch, M.; Schmitz, B.L.; Aschoff, A.J. [University Hospital of Ulm, Diagnostic and Interventional Radiology, Ulm (Germany)

    2008-07-15

    The purpose of this study was to evaluate the accuracy of multi-detector row helical CT (MDCT) for detection and localization of acute upper and lower gastrointestinal (GI) hemorrhage or intraperitoneal bleeding. Thirty-six consecutive patients with clinical signs of acute bleeding underwent biphasic (16- or 40-channel) MDCT. MDCT findings were correlated with endoscopy, angiography or surgery. Among the 36 patients evaluated, 26 were examined for GI bleeding and 10 for intraperitoneal hemorrhage. Confirmed sites of GI bleeding were the stomach (n = 5), duodenum (n = 5), small bowel (n = 6), large bowel (n = 8) and rectum (n = 2). The correct site of bleeding was identifiable on MDCT in 24/26 patients with GI bleeding. In 20 of these 24 patients, active CM extravasation was apparent during the exam. Among the ten patients with intraperitoneal hemorrhage, MDCT correctly identified the bleeding source in nine patients. Our findings suggest that fast and accurate localization of acute gastrointestinal and intraperitoneal bleeding is achievable on MDCT. (orig.)

  6. Detection and localization of acute upper and lower gastrointestinal (GI) bleeding with arterial phase multi-detector row helical CT

    International Nuclear Information System (INIS)

    Jaeckle, T.; Stuber, G.; Hoffmann, M.H.K.; Jeltsch, M.; Schmitz, B.L.; Aschoff, A.J.

    2008-01-01

    The purpose of this study was to evaluate the accuracy of multi-detector row helical CT (MDCT) for detection and localization of acute upper and lower gastrointestinal (GI) hemorrhage or intraperitoneal bleeding. Thirty-six consecutive patients with clinical signs of acute bleeding underwent biphasic (16- or 40-channel) MDCT. MDCT findings were correlated with endoscopy, angiography or surgery. Among the 36 patients evaluated, 26 were examined for GI bleeding and 10 for intraperitoneal hemorrhage. Confirmed sites of GI bleeding were the stomach (n = 5), duodenum (n = 5), small bowel (n = 6), large bowel (n = 8) and rectum (n = 2). The correct site of bleeding was identifiable on MDCT in 24/26 patients with GI bleeding. In 20 of these 24 patients, active CM extravasation was apparent during the exam. Among the ten patients with intraperitoneal hemorrhage, MDCT correctly identified the bleeding source in nine patients. Our findings suggest that fast and accurate localization of acute gastrointestinal and intraperitoneal bleeding is achievable on MDCT. (orig.)

  7. Multidetector-row computed tomography management of acute pulmonary embolism

    International Nuclear Information System (INIS)

    Yasui, Takahiro; Tanabe, Nobuhiro; Terada, Jiro

    2007-01-01

    The purpose of this study was to evaluate the usefulness and safety of multidetector-row computed tomography (MDCT) pulmonary angiography and indirect venography management of acute pulmonary embolism (PE), including indication for inferior vena cava (IVC) filter. Seventy-one consecutive patients who were clinically suspected of PE and underwent 16-slice MDCT pulmonary angiography and indirect venography were enrolled. Management included indication of IVC filter for patients with extensive deep venous thrombosis (DVT) in submassive or massive PE. A right ventricular to left ventricular short-axis diameter by MDCT >1.0 was judged as submassive PE. All patients were followed for 1 year. MDCT identified 50 patients with venous thromboembolism and 47 patients had acute PE: 4 were judged as massive, 14 as submassive, and 29 as non-massive by MDCT; 3 patients had DVT alone and 7 patients had caval or iliac DVT. Only 1 patient with massive PE and DVT near the right atrium died of recurrence. No other patients died of PE. Management based on MDCT pulmonary angiography combined with indirect venography is considered to be safe and reliable in patients with suspected acute PE. (author)

  8. Enhanced renal image contrast by ethanol fixation in phase-contrast X-ray computed tomography.

    Science.gov (United States)

    Shirai, Ryota; Kunii, Takuya; Yoneyama, Akio; Ooizumi, Takahito; Maruyama, Hiroko; Lwin, Thet Thet; Hyodo, Kazuyuki; Takeda, Tohoru

    2014-07-01

    Phase-contrast X-ray imaging using a crystal X-ray interferometer can depict the fine structures of biological objects without the use of a contrast agent. To obtain higher image contrast, fixation techniques have been examined with 100% ethanol and the commonly used 10% formalin, since ethanol causes increased density differences against background due to its physical properties and greater dehydration of soft tissue. Histological comparison was also performed. A phase-contrast X-ray system was used, fitted with a two-crystal X-ray interferometer at 35 keV X-ray energy. Fine structures, including cortex, tubules in the medulla, and the vessels of ethanol-fixed kidney could be visualized more clearly than that of formalin-fixed tissues. In the optical microscopic images, shrinkage of soft tissue and decreased luminal space were observed in ethanol-fixed kidney; and this change was significantly shown in the cortex and outer stripe of the outer medulla. The ethanol fixation technique enhances image contrast by approximately 2.7-3.2 times in the cortex and the outer stripe of the outer medulla; the effect of shrinkage and the physical effect of ethanol cause an increment of approximately 78% and 22%, respectively. Thus, the ethanol-fixation technique enables the image contrast to be enhanced in phase-contrast X-ray imaging.

  9. Novel ultrahigh resolution data acquisition and image reconstruction for multi-detector row CT

    International Nuclear Information System (INIS)

    Flohr, T. G.; Stierstorfer, K.; Suess, C.; Schmidt, B.; Primak, A. N.; McCollough, C. H.

    2007-01-01

    We present and evaluate a special ultrahigh resolution mode providing considerably enhanced spatial resolution both in the scan plane and in the z-axis direction for a routine medical multi-detector row computed tomography (CT) system. Data acquisition is performed by using a flying focal spot both in the scan plane and in the z-axis direction in combination with tantalum grids that are inserted in front of the multi-row detector to reduce the aperture of the detector elements both in-plane and in the z-axis direction. The dose utilization of the system for standard applications is not affected, since the grids are moved into place only when needed and are removed for standard scanning. By means of this technique, image slices with a nominal section width of 0.4 mm (measured full width at half maximum=0.45 mm) can be reconstructed in spiral mode on a CT system with a detector configuration of 32x0.6 mm. The measured 2% value of the in-plane modulation transfer function (MTF) is 20.4 lp/cm, the measured 2% value of the longitudinal (z axis) MTF is 21.5 lp/cm. In a resolution phantom with metal line pair test patterns, spatial resolution of 20 lp/cm can be demonstrated both in the scan plane and along the z axis. This corresponds to an object size of 0.25 mm that can be resolved. The new mode is intended for ultrahigh resolution bone imaging, in particular for wrists, joints, and inner ear studies, where a higher level of image noise due to the reduced aperture is an acceptable trade-off for the clinical benefit brought about by the improved spatial resolution

  10. Retrospectively ECG-gated multi-detector row CT of the chest: does ECG-gating improve three-dimensional visualization of the bronchial tree?

    International Nuclear Information System (INIS)

    Schertler, T.; Wildermuth, S.; Willmann, J.K.; Crook, D.W.; Marincek, B.; Boehm, T.

    2004-01-01

    Purpose: To determine the impact of retrospectively ECG-gated multi-detector row CT (MDCT) on three-dimensional (3D) visualization of the bronchial tree and virtual bronchoscopy (VB) as compared to non-ECG-gated data acquisition. Materials and Methods: Contrast-enhanced retrospectively ECG-gated and non-ECG-gated MDCT of the chest was performed in 25 consecutive patients referred for assessment of coronary artery bypass grafts and pathology of the ascending aorta. ECG-gated MDCT data were reconstructed in diastole using an absolute reverse delay of -400 msec in all patients. In 10 patients additional reconstructions at -200 msec, -300 msec, and -500 msec prior to the R-wave were performed. Shaded surface display (SSD) and virtual bronchoscopy (VB) for visualization of the bronchial segments was performed with ECG-gated and non-ECG-gated MDCT data. The visualization of the bronchial tree underwent blinded scoring. Effective radiation dose and signal-to-noise ratio (SNR) for both techniques were compared. Results: There was no significant difference in visualizing single bronchial segments using ECG-gated compared to non-ECG-gated MDCT data. However, the total sum of scores for all bronchial segments visualized with non-ECG-gated MDCT was significantly higher compared to ECG-gated MDCT (P [de

  11. Multi-detector row CT colonography: effect of collimation, pitch, and orientation on polyp detection in a human colectomy specimen.

    Science.gov (United States)

    Taylor, Stuart A; Halligan, Steve; Bartram, Clive I; Morgan, Paul R; Talbot, Ian C; Fry, Nicola; Saunders, Brian P; Khosraviani, Kirosh; Atkin, Wendy

    2003-10-01

    To investigate the effects of orientation, collimation, pitch, and tube current setting on polyp detection at multi-detector row computed tomographic (CT) colonography and to determine the optimal combination of scanning parameters for screening. A colectomy specimen containing 117 polyps of different sizes was insufflated and imaged with a multi-detector row CT scanner at various collimation (1.25 and 2.5 mm), pitch (3 and 6), and tube current (50, 100, and 150 mA) settings. Two-dimensional multiplanar reformatted images and three-dimensional endoluminal surface renderings from the 12 resultant data sets were examined by one observer for the presence and conspicuity of polyps. The results were analyzed with Poisson regression and logistic regression to determine the effects of scanning parameters and of specimen orientation on polyp detection. The percentage of polyps that were detected significantly increased when collimation (P =.008) and table feed (P =.03) were decreased. Increased tube current resulted in improved detection only of polyps with a diameter of less than 5 mm. Polyps of less than 5 mm were optimally depicted with a collimation of 1.25 mm, a pitch of 3, and a tube current setting of 150 mA; polyps with a diameter greater than 5 mm were adequately depicted with 1.25-mm collimation and with either pitch setting and any of the three tube current settings. Small polyps in the transverse segment (positioned at a 90 degrees angle to the z axis of scanning) were significantly less visible than those in parallel or oblique orientations (P detector row CT is highly dependent on collimation, pitch, and, to a lesser extent, tube current. Collimation of 1.25 mm, combined with pitch of 6 and tube current of 50 mA, provides for reliable detection of polyps 5 mm or larger while limiting the effective radiation dose. Polyps smaller than 5 mm, however, may be poorly depicted with use of these settings in the transverse colon. Copyright RSNA, 2003

  12. Automatic Bolus Tracking Versus Fixed Time-Delay Technique in Biphasic Multidetector Computed Tomography of the Abdomen

    International Nuclear Information System (INIS)

    Adibi, Atoosa; Shahbazi, Ali

    2014-01-01

    Bolus tracking can individualize time delay for the start of scans in spiral computed tomography (CT). We compared automatic bolus tracking method with fixed time-delay technique in biphasic contrast enhancement during multidetector CT of abdomen. Adult patients referred for spiral CT of the abdomen were randomized into two groups; in group 1, the arterial and portal phases of spiral scans were started 25 s and 55 s after the start of contrast material administration; in group 2, using the automatic bolus tracking software, repetitive monitoring scans were performed within the lumen of the descending aorta as the region of interest with the threshold of starting the diagnostic scans as 60 HU. The contrast enhancement of the aorta, liver, and spleen were compared between the groups. Forty-eight patients (23 males, 25 females, mean age=56.4±13.5 years) were included. The contrast enhancement of the aorta, liver, and spleen at the arterial phase was similar between the two groups (P>0.05). Regarding the portal phase, the aorta and spleen were more enhanced in the bolus-tracking group (P<0.001). The bolus tracking provided more homogeneous contrast enhancement among different patients than the fixed time-delay technique in the liver at portal phase, but not at the arterial phase. The automatic bolus-tracking method, results in higher contrast enhancement of the aorta and spleen at the portal phase, but has no effect on liver enhancement. However, bolus tracking is associated with reduced variability for liver enhancement among different patients

  13. Automatic individualized contrast medium dosage during hepatic computed tomography by using computed tomography dose index volume (CTDI{sub vol})

    Energy Technology Data Exchange (ETDEWEB)

    Svensson, Anders; Cederlund, Kerstin; Aspelin, Peter; Brismar, Torkel B. [Intervention and Technology at Karolinska Institutet, Department of Clinical Science, Division of Medical Imaging and Technology, Stockholm (Sweden); Karolinska University Hospital in Huddinge, Department of Radiology, Stockholm (Sweden); Bjoerk, Jonas [FoU-centrum Skaane Skaanes Universitetssjukhus i Lund, Lund (Sweden); Nyman, Ulf [University of Lund, Department of Diagnostic Radiology, Lasarettet Trelleborg, Trelleborg (Sweden)

    2014-08-15

    To compare hepatic parenchymal contrast media (CM) enhancement during multi-detector row computed tomography (MDCT) and its correlation with volume pitch-corrected computed tomography dose index (CTDI{sub vol}) and body weight (BW). One hundred patients referred for standard three-phase thoraco-abdominal MDCT examination were enrolled. BW was measured in the CT suite. Forty grams of iodine was administered intravenously (iodixanol 320 mg I/ml at 5 ml/s or iomeprol 400 mg I/ml at 4 ml/s) followed by a 50-ml saline flush. CTDI{sub vol} presented by the CT equipment during the parenchymal examination was recorded. The CM enhancement of the liver was defined as the attenuation HU of the liver parenchyma during the hepatic parenchymal phase minus the attenuation in the native phase. Liver parenchymal enhancement was negatively correlated to both CTDI{sub vol} (r = -0.60) and BW (r = -0.64), but the difference in correlation between those two was not significant. CTDI{sub vol} may replace BW when adjusting CM doses to body size. This makes it potentially feasible to automatically individualize CM dosage by CT. (orig.)

  14. Prospective Electrocardiogram-Gated Multidetector Row Computed Tomography Coronary Angiography. Analysis of Quality Image and Radiation Dose

    International Nuclear Information System (INIS)

    Carrascosa, P.; Capunay, C.; Deviggiano, A.; Tajer, C.D.; Vallejos, J.; Goldsmit, A.; Garcia, M.J.

    2009-01-01

    Multidetector row computed tomography coronary angiography (MDCT-CA) has become a useful diagnostic tool for the direct quantification of coronary stenosis, for identifying coronary anomalies and for the assessment of coronary artery bypass grafts. Despite its clinical value has been questioned due to the effective radiation dose (ERD) received by each patient, radiation exposure is similar to other studies. However, different strategies are permanently tested in order to reduce the ERD maintaining adequate and diagnostic image quality. Objectives: To determine the image quality and effective radiation dose (ERD) of prospective electrocardiogram-gated multidetector row computed tomography coronary angiography (PMDCTCA) (the x-ray beam is turned on for only a short portion of diastole) compared to retrospective ECG gating (RMDCTCA) (the x-ray beam is turned on throughout the cardiac cycle) and a preliminary approach of its diagnostic accuracy compared to digital invasive coronary angiography (CA). Material and Methods: Fifty consecutive patients with suspected coronary artery disease and sinus rhythm were evaluated with PMDCT-CA and compared to a control group who underwent RMDCTCA. Image quality was analyzed by two reviewers. Interobserver concordance and ERD were determined. The diagnostic accuracy of PMDCT-CA compared to CA to detect coronary artery stenosis > 50% was assessed in 30 patients. Results: There were no significant differences in the image quality between both groups. Agreement between the reviewers for segment image quality scores was k = 0.92. Mean ERD was 3.5 mSv for PMDCT-CA compared to 9.7 and 12.9 mSv for RMDCT-CA with and without tube current modulation, respectively. Individual analysis including all segments showed that the sensitivity, specificity, positive predictive value and negative predictive value of PMDCT-CA for the detection of coronary stenosis were 94.74%, 81.82%, 90% and 90%, respectively. Conclusion: Our initial experience

  15. Effectiveness of thin-slice axial images of multidetector row CT for visualization of bronchial artery before bronchial arterial embolization

    International Nuclear Information System (INIS)

    Shida, Yoshitaka; Hasuo, Kanehiro; Aibe, Hitoshi; Kubo, Yuko; Terashima, Kotaro; Kinjo, Maya; Kamano, H.; Yoshida, Atsuko

    2008-01-01

    We assessed the ability of visualization of bronchial artery (BA) by using thin-slice axial images of 4-detector multidetector row CT in 65 patients with hemoptysis. In all patients, the origins of BA were well identified with observation of consecutive axial images with 1 mm thickness by paging method and bronchial arterial embolization (BAE) was performed successfully. Thin-slice axial images were considered to be useful to recognize BA and to perform BAE in patients with hemoptysis. (author)

  16. 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.

  17. Estudio vascular renal por TC multidetector de 64 canales 64-Multidetector row CT for the Renal Vascular Study

    OpenAIRE

    Daniela Stoisa; Fabrizzio E. Galiano; Andrés Quaranta; Roberto L. Villavicencio

    2009-01-01

    Objetivo: Mostrar las diversas variantes anatómicas vasculares tanto arteriales como venosas en el estudio angiográfico renal por tomografìa computada multidetector (TCMD) de 64 canales, dada su implicancia en un eventual planeamiento quirúrgico. Material y métodos: Evaluamos retrospectivamente 26 estudios realizados con tomógrafo Philips Brilliance de 64 canales. Se obtuvieron secuencias sin contraste y postcontraste e.v. en fases arterial y venosa, administrado con bomba inyectora doble cab...

  18. Multidetector row computed tomography findings from ischemia to infarction of the large bowel

    International Nuclear Information System (INIS)

    Romano, Stefania; Romano, Luigia; Grassi, Roberto

    2007-01-01

    Objective: MDCT is performed as first imaging examination for patients with acute abdomen in most Emergency Departments. Clinical suspicion of ischemic colitis and infarction is related to specific findings, however, differential diagnosis as well as the staging for a confirmed ischemic affection may be critical. The individual signs from ischemia to infarction of large bowel is a captivating topic. In this study, we report our experience of the MDCT assessment of acute colonic disease from vascular mesenteric disorders. Materials and methods: We retrospectively reviewed the MDCT findings of 71 patients admitted to our attention for acute abdomen, with final proven diagnosis of colonic ischemia and/or infarction made by surgery and/or endoscopy. CT-scanning of the abdomen and pelvis was performed after i.v. contrast medium administration, using a multidetector row CT equipment. We correlated the presence of parietal disease, the evidence of mesenteric arterial or venous vessels occlusion, the parietal features as well as others findings, such as free fluid and/or air in peritoneal recess or in retroperitoneum, with the surgical and/or endoscopic findings. Results: Analysis of our data showed a segmental (84%) or complete (16%) involvement of the colon; 57 cases were related to ischemia, 14 to infarction. Inferior mesenteric vessels defect of opacification was noted in 10 cases. Various degree of wall thickening and parietal enhancement, peritoneal fluid, mural or portal-mesenteric pneumatosis were compared to evidence of mesenteric arterial or vein occlusion and to final proven diagnosis. A classification in a multi-stage grading for both decreased of arterial supply or impaired venous drainage disorders was done. Conclusions: A grading scale from ischemia to infarction affecting the large bowel from arterial or venous mesenteric vessels origin has been not previously reported in a series at our knowledge. MDCT findings may support the clinical evaluation of

  19. Imaging quality and effective radiation dose of prospective ECG-gated axial multidetector row computed tomography coronary angiography

    International Nuclear Information System (INIS)

    Capunay, C.; Carrascosa, P.; Vallejos, J.; Deviggiano, A.; Pollono, P.M.; Garcia, M.J.

    2011-01-01

    Objective. To determine the imaging quality and effective radiation dose (ERD) of prospective ECG-gated multidetector row computed tomography coronary angiography (PMDCTCA) compared to retrospective ECG-gating (RMDCT-CA). Materials and Methods. Forty-five PMDCT-CA scans were retrospectively reviewed for assessing imaging quality and ERD, and compared to 90 RMDCT-CA scans performed with (n=45) and without (n=45) tube current modulation, selected from our database on the basis of similar demographical characteristics. ERD was compared between all three groups. Imaging quality was assessed by two independent observers and compared to the imaging quality of the group of RMDCT-CA scans performed with tube current modulation. The interobserver variability was also determined. Results. There were no significant differences in imaging quality between the two groups. Interobserver variability was k=0.92 (95 % CI: 0.87-0.96). The ERD (mean ± SD) using PMDCT-CA was 2.88 ± 0.37 mSv compared to 10.50 ± 1.15 mSv (p [es

  20. Multidetector-row helical CT: analysis of time management and workflow

    Energy Technology Data Exchange (ETDEWEB)

    Roos, Justus E.; Desbiolles, Lotus M.; Willmann, Juergen K.; Weishaupt, Dominik; Marincek, Borut; Hilfiker, Paul R. [Institute of Diagnostic Radiology, University Hospital Zurich (Switzerland)

    2002-03-01

    The purpose of this study was to evaluate time management and workflow for multidetector-row helical CT (MDCT). Time for patient and data handling of at total of 580 patients were evaluated at two different time periods (December 1999, August 2000), each for the following baseline measurements: (a) change of clothes/instruction; (b) patient placement on the CT table/i.v. catheter; (c) CT planning and programming; (d) CT data acquisition; (e) CT data reconstruction; (f) CT data storage/printing. All imaging was performed on a Somatom Volume Zoom (Siemens, Erlangen, Germany). Time measurements summarized for different CT protocols revealed the following: (a) 5:01 min ({+-}2.06 min); (b) 4:36 min ({+-}2.43 min); (c) 4:11 min ({+-}2.55 min); (d) 0:43 min ({+-}0.15 min); (e) 6:59 min ({+-}2.39 min); (f) 09:51 min ({+-}3.51 min). Planning and programming was most time-consuming for CT angiography, whereas chest and abdominal CT needed only 3:26 and 3:30 min, respectively. Reconstruction time was highest for HRCT (9:22 min) and CTA (9:03 min). Data storage/printing was most time-consuming for HRCT (13:02 min), followed by combined neck-chest-abdomen examinations (12:19 min). Comparing the two time periods, during which a software update was performed, a mean time reduction of 4:31 min per patient (15%, p<0.001) was achieved. Whereas CT data acquisition time is no longer a problem with MDCT, patient management, data reconstruction, and data storage are the most time-consuming parts. Well-trained technicians, state-of-the-art workstations, and fast networking are the most important factors to improve workflow. (orig.)

  1. Dose-reduced 16-slice multidetector-row spiral computed tomography in children with bronchoscopically suspected vascular tracheal stenosis - initial results

    International Nuclear Information System (INIS)

    Honnef, D.; Wildberger, J.E.; Das, M.; Hohl, C.; Mahnken, A.; Guenther, R.W.; Staatz, G.; Schnoering, H.; Vazquez-Jimenez, J.

    2006-01-01

    Purpose: To evaluate the diagnostic accuracy of contrast-enhanced dose-reduced 16-slice multidetector-row CT (MDCT) in newborns and infants with fiberoptic bronchoscopically suspected vascular-induced tracheal stenosis. Materials and Methods: 12 children (4 days to 3 years, 1.2-13.5 kg body weight) were examined using i.v. contrast-enhanced 16-slice MDCT (SOMATOM Sensation 16, Forchheim, Germany) without breath-hold and under sedation (11/12). All MDCTs were performed with a dose reduction. The beam collimation was 16 x 0.75 mm, except in the case of one child. MPRs along the tracheal axis in the x-, y- and z-directions and volume-rendering-reconstructions (VRTs) were calculated based on a secondary raw data set in addition to conventional axial slices. 2 radiologists used a three-point grade scale to evaluate the image quality, motion, and contrast media artifacts as well as the usefulness of the 2D- and 3D-reconstructions for determining the diagnosis. Statistical analysis was performed on the basis of a Kappa test. Results: In all cases the cause of the fiberoptic bronchoscopically suspected tracheal stenosis was revealed: compression due to the brachiocephalic trunk (n=7), double aortic arch (n=2), lusorian artery (n=1), vascular compression of the left main bronchus (n=2). In 3 patients further thoracic anomalies, such as tracheobronchial (n=2), and vascular (n=2) and vertebral (n=1) anomalies were found. The attenuation in the anomalous vessels was 307±140 HU. The image noise was 9.8±1.9 HU. The mean dose reduction was 82.7±3.2% compared to a standard adult thoracic CT. All examinations were rated as diagnostically good (median 1, range 1, k=1). 3D images did not show any stair artifacts (median 2, range 1-2, k=1). The image noise was minor to moderate and hardly any motion artifacts were seen (median 1, range 1-2, k=0.8). Contrast media artifacts were rated zero to minor (median 1.5, range 1-2, k=0.676). MPRs (median 1, range 1, k=1) and VRTs (median 1

  2. 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.

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

    International Nuclear Information System (INIS)

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

    2012-01-01

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

  4. Sixteen multidetector row computed tomography of pulmonary veins: 3-months' follow-up after treatment of paroxysmal atrial fibrillation with cryothermal ablation

    International Nuclear Information System (INIS)

    Maksimovic, Ruzica; Cademartiri, Filippo; Pattynama, Peter M.T.; Scholten, Marcoen F.; Jordaens, Luc J.

    2005-01-01

    The aim of the study was to assess pulmonary veins (PVs) for the presence of stenosis 3 months after cryothermal ablation (CA) with a new method of electrical isolation of PVs using contrast-enhanced 16 multidetector row computed tomography (MDCT). Twenty four patients with symptomatic atrial fibrillation underwent CA in 46 PVs. MDCT of PVs was performed before the treatment and after 3-months' follow-up. Following cryoablation, 13/24 (54%) patients showed clinical improvement and had reduced attacks of atrial fibrillation. The dimensions of the treated PVs remained unchanged: the coronal ostial diameter was 19.1±2.4 preprocedural versus 18.6±2.4 mm at follow-up, p>0.05; the ratio of the coronal and axial diameters at the ostium was 1.2±0.2 versus 1.2±0.1, p>0.05, respectively, and the coronal diameter of the proximal 10 mm was 17.1±2.5 mm versus 16.5±2.2 mm, p>0.05, respectively. CA is a promising technique for electrical isolation of PVs that has not been associated with stenosis at the orifice and the proximal 10 mm of the PVs after 3-months' follow-up. MDCT is a noninvasive, fast and comfortable method for assessment of PVs in a three-dimensional manner prior to ablative treatment and during the follow-up. (orig.)

  5. Impact of the use of contrast-enhancement multidetector CT for acute appendicitis: a prospective comparison with the Alvarado score

    International Nuclear Information System (INIS)

    Choi, Mi Young; Yoon, Seong Eon; Lee, Young Hwan; Choi, Shi Sung; Park, Seong Hoon; Juhng, Seong Kwan; Yoon, Kwon Ha; Park, Seong Ho

    2007-01-01

    To determine the diagnostic performance of contrast-enhanced multidetector CT (MDCT) and the Alvarado score for acute appendicitis. MDCT and determination of the Alvarado score were prospectively performed in 282 patients with 146 pathologically proven cases of acute appendicitis and 136 pathologically proven or clinically diagnosed cases of non-acute appendicitis. To compare the diagnostic performance of MDCT and the Alvarado score, the patients were subdivided according to age and sex, and receiver operating characteristics (ROC) analysis and Spearman rank correlation were performed. ROC analysis revealed that the optimal cut off value of the CT appendicitis grades was 2 in all patients, resulting in a sensitivity of 96.6% and a specificity of 94.9%. The optimal cut off values of the Alvarado score was different according to age and sex, resulting in a sensitivity of 85.6% and a specificity of 48.5%. There was a significant correlation between the CT appendicitis grades and the surgical-pathological grades (r = 0.496, ρ < .0001). However, no significant correlation was observed between the Alvarado score and the surgical-pathological grades. Contrast-enhanced MDCT has a higher diagnostic accuracy and significant correlation with pathological findings than those of the Alvarado score in patients with acute appendicitis

  6. Impact of the use of contrast-enhancement multidetector CT for acute appendicitis: a prospective comparison with the Alvarado score

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Mi Young; Yoon, Seong Eon; Lee, Young Hwan; Choi, Shi Sung; Park, Seong Hoon; Juhng, Seong Kwan; Yoon, Kwon Ha [Wonkwang University School of Medicine, Iksan (Korea, Republic of); Park, Seong Ho [University of Ulsan College of Medicine, Asan Medical Center, Seoul (Korea, Republic of)

    2007-12-15

    To determine the diagnostic performance of contrast-enhanced multidetector CT (MDCT) and the Alvarado score for acute appendicitis. MDCT and determination of the Alvarado score were prospectively performed in 282 patients with 146 pathologically proven cases of acute appendicitis and 136 pathologically proven or clinically diagnosed cases of non-acute appendicitis. To compare the diagnostic performance of MDCT and the Alvarado score, the patients were subdivided according to age and sex, and receiver operating characteristics (ROC) analysis and Spearman rank correlation were performed. ROC analysis revealed that the optimal cut off value of the CT appendicitis grades was 2 in all patients, resulting in a sensitivity of 96.6% and a specificity of 94.9%. The optimal cut off values of the Alvarado score was different according to age and sex, resulting in a sensitivity of 85.6% and a specificity of 48.5%. There was a significant correlation between the CT appendicitis grades and the surgical-pathological grades (r = 0.496, {rho} < .0001). However, no significant correlation was observed between the Alvarado score and the surgical-pathological grades. Contrast-enhanced MDCT has a higher diagnostic accuracy and significant correlation with pathological findings than those of the Alvarado score in patients with acute appendicitis.

  7. Diagnostic value of multidetector row CT in rectal cancer staging: comparison of multiplanar and axial images with histopathology

    International Nuclear Information System (INIS)

    Sinha, R.; Verma, R.; Rajesh, A.; Richards, C.J.

    2006-01-01

    Aim: Although magnetic resonance (MR) imaging is widely used for rectal cancer staging, many centres in the UK perform computed tomography (CT) for staging rectal cancer at present. Furthermore in a small proportion of cases contraindications to MR imaging may lead to staging using CT. The purpose of this study was to evaluate the accuracy of current generation multidetector row CT (MDCT) in local staging of rectal cancer. In particular the accuracy of multiplanar (MPR) versus axial images in the staging of rectal cancer was assessed. Material and methods: Sixty-nine consecutive patients were identified who had undergone staging of rectal cancer on CT. The imaging data were reviewed as axial images and then as MPR images (coronal and sagittal) perpendicular and parallel to the tumour axis. CT staging on axial and MPR images was then compared to histopathological staging. Results: MPR images detected more T4 and T3 stage tumours than axial images alone. The overall accuracy of T-staging on MPR images was 87.1% versus 73.0% for axial images alone. The overall accuracy of N staging on MPR versus axial images was 84.8% versus 70.7%. There was a statistically significant difference in the staging of T3 tumours between MPR and axial images (p < 0.001). Conclusion: Multidetector row CT has high accuracy for local staging of rectal cancer. Addition of MPR images to standard axial images provides higher accuracy rates for T and N staging of rectal cancer than axial images alone

  8. Sixteen multidetector row computed tomography of pulmonary veins: 3-months' follow-up after treatment of paroxysmal atrial fibrillation with cryothermal ablation

    Energy Technology Data Exchange (ETDEWEB)

    Maksimovic, Ruzica; Cademartiri, Filippo; Pattynama, Peter M.T. [Erasmus Medical Center, Department of Radiology, Rotterdam (Netherlands); Scholten, Marcoen F.; Jordaens, Luc J. [Erasmus Medical Center, Department of Cardiology, Rotterdam (Netherlands)

    2005-06-01

    The aim of the study was to assess pulmonary veins (PVs) for the presence of stenosis 3 months after cryothermal ablation (CA) with a new method of electrical isolation of PVs using contrast-enhanced 16 multidetector row computed tomography (MDCT). Twenty four patients with symptomatic atrial fibrillation underwent CA in 46 PVs. MDCT of PVs was performed before the treatment and after 3-months' follow-up. Following cryoablation, 13/24 (54%) patients showed clinical improvement and had reduced attacks of atrial fibrillation. The dimensions of the treated PVs remained unchanged: the coronal ostial diameter was 19.1{+-}2.4 preprocedural versus 18.6{+-}2.4 mm at follow-up, p>0.05; the ratio of the coronal and axial diameters at the ostium was 1.2{+-}0.2 versus 1.2{+-}0.1, p>0.05, respectively, and the coronal diameter of the proximal 10 mm was 17.1{+-}2.5 mm versus 16.5{+-}2.2 mm, p>0.05, respectively. CA is a promising technique for electrical isolation of PVs that has not been associated with stenosis at the orifice and the proximal 10 mm of the PVs after 3-months' follow-up. MDCT is a noninvasive, fast and comfortable method for assessment of PVs in a three-dimensional manner prior to ablative treatment and during the follow-up. (orig.)

  9. Multi-detector row CT in the assessment of axillary lymph node metastasis in breast cancer

    International Nuclear Information System (INIS)

    Murakami, Shogo

    2003-01-01

    The purpose of this study is to evaluate the diagnostic capability instead of clinical efficacy of multi-detector row CT (MDCT) in the assessment of axillary lymph node metastasis in breast cancer. MDCT was performed in 63 patients with breast cancer, and multiplanar reformation (MPR) and volume rendering (VR) images were reconstructed for the evaluation of bilateral axillary lymph nodes. Two hundred sixty eight lymph nodes were depicted with MDCT, and correlation with pathological findings was performed. The short axis length of lymph node was measured on MPR image, and the shape of the nodes was analyzed with the pathological results statistically. The diagnostic criteria on size and shape of lymph node metastasis were discussed Dynamic study with contrast media was also performed, and the CT value ratios (CTVR) of the lymph nodes and breast tumors were calculated. No relevance of axillary lymph node metastasis was noted to the pathological types of breast cancer. The average short axis length of the ipsilateral axillary nodes was 8.9 mm±3.8 (SD) while that of the contralateral nodes was 4.9 mm±1.1 (SD) showing significant difference. More than 6.5 mm in short length of the lymph node was thought to be an effective criterion for positive metastasis, and its sensitivity was 96%. Soybean-shape lymph node was statistically common in metastasis, while non-metastatic nodes were commonly demonstrated as letter ''c'' shape or ring-like shape. Statistical relevance was obtained between the CTVR of axillary lymph nodes and that of breast tumors, suggesting clinical usefulness of dynamic study using contrast media in the evaluation of lymph node metastasis. With MPR and VR images using MDCT, more accurate morphological evaluation of axillary lymph nodes was possible. When soybean-shape node with more than 6.5 mm in short axis is depicted in the axillar region on MDCT metastasis should be the consideration. Comparison with the contralateral side as a control in coronal

  10. Right heart on multidetector CT

    Science.gov (United States)

    Gopalan, D

    2011-01-01

    Right ventricular function plays an integral role in the pathogenesis and outcome of many cardiovascular diseases. Imaging the right ventricle has long been a challenge because of its complex geometry. In recent years there has been a tremendous expansion in multidetector row CT (MDCT) and its cardiac applications. By judicious modification of contrast medium protocol, it is possible to achieve good opacification of the right-sided cardiac chambers, thereby paving the way for exploring the overshadowed right heart. This article will describe the key features of right heart anatomy, review MDCT acquisition techniques, elaborate the various morphological and functional information that can be obtained, and illustrate some important clinical conditions associated with an abnormal right heart. PMID:22723537

  11. Clinical assessment of hypopharyngeal and laryngeal disorders by three-dimensional multidetector-row CT. Feasibility of imaging during phonation

    International Nuclear Information System (INIS)

    Tan, Xiaotian

    2002-01-01

    The hypopharynx and larynx can adapt their structures to physiological functions. To clarify the relation between morphologic changes and the development of pharyngeal and laryngeal disorders, images of the hypopharynx and larynx were obtained by multidetector-row CT (MD-CT) during phonation and quiet breathing. The clinical usefulness of such imaging study was assessed by comparing the images taken in the two phases. The study included 23 subjects, 20 patients with a hypopharyngeal or laryngeal disorder and 3 healthy volunteers. MD-CT scanning of the hypopharynx and larynx was not influenced by breathing and body movement. The volume rendering (VR) method was useful in that three-dimensional imaging could visualize the internal structure of the hypopharynx and larynx. Thus, the volume rendering method can be regarded as a virtual three-dimensional method. The normal anatomic structure of the hypopharynx and larynx were depicted in full and three-dimensionally. The extent of hypopharyngeal and laryngeal cancer was shown clearly. Edema due to paralysis of recurrent nerve was demonstrated in full and three-dimensionally, providing for functional diagnosis. In the case of mucosal edema caused by trauma, the extent of the edema and its effect on the airway were clearly observed. These results suggest that MD-CT with three-dimensional imaging during phonation is useful in the diagnosis of hypopharyngeal and laryngeal disorders. (author)

  12. Dose reduction in multidetector CT of the urinary tract. Studies in a phantom model

    International Nuclear Information System (INIS)

    Coppenrath, E.; Meindl, T.; Herzog, P.; Khalil, R.; Mueller-Lisse, U.; Krenn, L.; Reiser, M.; Mueller-Lisse, U.G.

    2006-01-01

    A novel ureter phantom was developed for investigations of image quality and dose in CT urography. The ureter phantom consisted of a water box (14 cm x 32 cm x 42 cm) with five parallel plastic tubes (diameter 2.7 mm) filled with different concentrations of contrast media (1.88-30 mg iodine/ml). CT density of the tubes and noise of the surrounding water were determined using two multidetector scanners (Philips MX8000 with four rows, Siemens Sensation 16 with 16 rows) with varying tube current-time product (15-100 mAs per slice), voltage (90 kV, 100 kV, 120 kV), pitch (0.875-1.75), and slice thickness (1 mm, 2 mm, 3.2 mm). Contrast-to-noise ratio as a parameter of image quality was correlated with dose (CTDI) and was compared with image evaluation by two radiologists. The CT densities of different concentrations of contrast media and contrast-to-noise ratio were significantly higher when low voltages (90 kV versus 120 kV, 100 kV versus 120 kV) were applied. Smaller slice thickness (1 mm versus 2 mm) did not change CT density but decreased contrast-to-noise ratio due to increased noise. Contrast phantom studies showed favourable effects of low tube voltage on image quality in the low dose range. This may facilitate substantial dose reduction in CT urography. (orig.)

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

    International Nuclear Information System (INIS)

    Osada, Hisato; Watanabe, Wataru; Okada, Taketomo

    2007-01-01

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

  14. What is the best contrast injection protocol for 64-row multi-detector cardiac computed tomography?

    International Nuclear Information System (INIS)

    Lu Jinguo; Lv Bin; Chen Xiongbiao; Tang Xiang; Jiang Shiliang; Dai Ruping

    2010-01-01

    Objective: To determine the optimal contrast injection protocol for 64-MDCT coronary angiography. Materials and methods: One hundred and fifty consecutive patients scheduled to undergo retrospectively electrocardiographically gated 64-MDCT. Each 30 patients were assigned to use a different contrast protocol: group 1: uniphasic protocol (contrast injection without saline flush); group 2: biphasic protocol (contrast injection with saline flush); group 3A, 3B and 3C: triphasic protocol (contrast media + different saline diluted contrast media + saline flush). Image quality scores and artifacts were compared and evaluated on both transaxial and three-dimensional coronary artery images among each contrast protocol. Results: Among the triphasic protocol groups, group 3A (30%:70% contrast media-saline mixture was used in second phase) used the least contrast media and had the least frequency of streak artifacts, but there were no significant differences in coronary artery attenuation, image quality, visualization right and left heart structures. Among the uniphasic protocol group (group 1), biphasic protocol group (group 2) and triphasic protocol subgroup (group 3A), there were no significant differences in image quality scores of coronary artery (P = 0.18); uniphasic protocol group had the highest frequency of streak artifacts (20 cases) (P < 0.05) and had the most amount contrast media (67.0 ± 5.3 ml); biphasic protocol group had the least amount of contrast media (59.9 ± 4.9 ml) (P < 0.05) and had the highest attenuation of left main coronary artery and right coronary artery (P < 0.01), but had the least amount of clear visualization right heart structure (6 cases); triphasic protocol group (group 3A) had the most amount of clear visualization right heart structures (29 cases) were the most among the three groups (P < 0.05). Conclusion: Biphasic protocol are superior to the traditional uniphasic protocols for using the least total contrast media, having the least

  15. What is the best contrast injection protocol for 64-row multi-detector cardiac computed tomography?

    Energy Technology Data Exchange (ETDEWEB)

    Lu Jinguo [Department of Radiology, Cardiovascular Institute and Fuwai Hospital, Peking Union Medical College and Chinese Academy of Medical Sciences, 167 Beilishi Road, Beijing (China); Lv Bin, E-mail: blu@vip.sina.co [Department of Radiology, Cardiovascular Institute and Fuwai Hospital, Peking Union Medical College and Chinese Academy of Medical Sciences, 167 Beilishi Road, Beijing (China); Chen Xiongbiao; Tang Xiang; Jiang Shiliang; Dai Ruping [Department of Radiology, Cardiovascular Institute and Fuwai Hospital, Peking Union Medical College and Chinese Academy of Medical Sciences, 167 Beilishi Road, Beijing (China)

    2010-08-15

    Objective: To determine the optimal contrast injection protocol for 64-MDCT coronary angiography. Materials and methods: One hundred and fifty consecutive patients scheduled to undergo retrospectively electrocardiographically gated 64-MDCT. Each 30 patients were assigned to use a different contrast protocol: group 1: uniphasic protocol (contrast injection without saline flush); group 2: biphasic protocol (contrast injection with saline flush); group 3A, 3B and 3C: triphasic protocol (contrast media + different saline diluted contrast media + saline flush). Image quality scores and artifacts were compared and evaluated on both transaxial and three-dimensional coronary artery images among each contrast protocol. Results: Among the triphasic protocol groups, group 3A (30%:70% contrast media-saline mixture was used in second phase) used the least contrast media and had the least frequency of streak artifacts, but there were no significant differences in coronary artery attenuation, image quality, visualization right and left heart structures. Among the uniphasic protocol group (group 1), biphasic protocol group (group 2) and triphasic protocol subgroup (group 3A), there were no significant differences in image quality scores of coronary artery (P = 0.18); uniphasic protocol group had the highest frequency of streak artifacts (20 cases) (P < 0.05) and had the most amount contrast media (67.0 {+-} 5.3 ml); biphasic protocol group had the least amount of contrast media (59.9 {+-} 4.9 ml) (P < 0.05) and had the highest attenuation of left main coronary artery and right coronary artery (P < 0.01), but had the least amount of clear visualization right heart structure (6 cases); triphasic protocol group (group 3A) had the most amount of clear visualization right heart structures (29 cases) were the most among the three groups (P < 0.05). Conclusion: Biphasic protocol are superior to the traditional uniphasic protocols for using the least total contrast media, having the least

  16. Experiences of using a single post-contrast CT scan of the urinary tract after triphasic contrast injection

    Directory of Open Access Journals (Sweden)

    Phillip Carl Pretorius

    2011-12-01

    Full Text Available I was alerted to an article in Radiology Vol. 255 No. 2 (May 20101 by a colleague. The article, entitled ‘Kidney and urinary tract imaging: Triple-bolus multidetector CT urography as a one-stop shop – Protocol design, opacification, and image quality analysis’, clearly describes the technique, while the quotation below, from the article, summarises the findings: ‘We have shown that triple-bolus multidetector CT urography allowed visualization of renal parenchymal, excretory, and vascular contrast-enhancement phases in a single dose-efficient acquisition and provided sufficient opacification of the UUT, with simultaneous and adequate image quality of renal parenchyma and vascular anatomy.’ The main emphasis on this technique is to reduce the number of unnecessary CT scans when assessing the urinary tract. Our previous protocol for scanning the urinary tract for pathology included four phases: a pre-contrast, corticomedullary, nephrographic and delay excretory phase.

  17. Venous variants and anomalies on routine abdominal multi-detector row CT

    International Nuclear Information System (INIS)

    Koc, Zafer; Ulusan, Serife; Oguzkurt, Levent; Tokmak, Naime

    2007-01-01

    Objective: This study aims to determine the types and prevalence rates of anatomic variations of the hepatic veins, portal vein, inferior vena cava and renal veins, and to establish statistical correlations between various anomalies and frequency differences between male and female using multi-detector row computed tomography (CT). Materials and methods: One thousand one hundred and twenty patients (588 men, 532 women) were evaluated with routine abdominal CT. Frequencies of different variants were noted and compared, and correlations between three categories of variation were tested. Results: In total, 1261 abdominal vein variants and anomalies were identified in 756 (67.5%) of 1120 patients. Six hundred and forty-two hepatic vein variants were detected in 468 (41.8%) patients. One or more inferior right hepatic veins were identified in 356 (31.8%) individuals, and tributary hepatic veins were detected in 147 (13.1%) patients. Portal vein variations and anomalies were observed in 307 (27.4%) cases. The most frequent of these was trifurcation (139 patients, 12.4%). A total of 311 inferior vena cava and renal vein variants were identified in 258 (23%) cases. Six patients (0.5%) exhibited inferior vena cava anomalies, 62 (5.5%) had circumaortic renal veins, 53 (4.7%) had retroaortic renal veins, and 210 (18.8%) had multiple renal veins. Conclusion: The prevalence of abdominal vein variations is high, and routine abdominal CT demonstrates these abnormalities very well. The data suggest that hepatic vein variants and multiple right renal veins are more frequent in women than in men, and that hepatic vein variation is correlated with portal vein variation

  18. Venous variants and anomalies on routine abdominal multi-detector row CT

    Energy Technology Data Exchange (ETDEWEB)

    Koc, Zafer [Baskent University, School of Medicine, Department of Radiology, Adana (Turkey)]. E-mail: koczafer@gmail.com; Ulusan, Serife [Baskent University, School of Medicine, Department of Radiology, Adana (Turkey); Oguzkurt, Levent [Baskent University, School of Medicine, Department of Radiology, Adana (Turkey); Tokmak, Naime [Baskent University, School of Medicine, Department of Radiology, Adana (Turkey)

    2007-02-15

    Objective: This study aims to determine the types and prevalence rates of anatomic variations of the hepatic veins, portal vein, inferior vena cava and renal veins, and to establish statistical correlations between various anomalies and frequency differences between male and female using multi-detector row computed tomography (CT). Materials and methods: One thousand one hundred and twenty patients (588 men, 532 women) were evaluated with routine abdominal CT. Frequencies of different variants were noted and compared, and correlations between three categories of variation were tested. Results: In total, 1261 abdominal vein variants and anomalies were identified in 756 (67.5%) of 1120 patients. Six hundred and forty-two hepatic vein variants were detected in 468 (41.8%) patients. One or more inferior right hepatic veins were identified in 356 (31.8%) individuals, and tributary hepatic veins were detected in 147 (13.1%) patients. Portal vein variations and anomalies were observed in 307 (27.4%) cases. The most frequent of these was trifurcation (139 patients, 12.4%). A total of 311 inferior vena cava and renal vein variants were identified in 258 (23%) cases. Six patients (0.5%) exhibited inferior vena cava anomalies, 62 (5.5%) had circumaortic renal veins, 53 (4.7%) had retroaortic renal veins, and 210 (18.8%) had multiple renal veins. Conclusion: The prevalence of abdominal vein variations is high, and routine abdominal CT demonstrates these abnormalities very well. The data suggest that hepatic vein variants and multiple right renal veins are more frequent in women than in men, and that hepatic vein variation is correlated with portal vein variation.

  19. Peliosis Hepatis with Hemorrhagic Necrosis and Rupture: a Case Report with Emphasis on the Multi-Detector CT Findings

    International Nuclear Information System (INIS)

    Kim, Eun-A; Yoon, Kwon-Ha; Jeon, Se-Jung; Cai, Quan-Yu; Lee, Young-Whan

    2007-01-01

    We demonstrate the imaging findings, with emphasis on the triphasic, contrast-enhanced multidetector CT findings, as well as reporting the clinical outcome in a case of peliosis hepatis with fatal hemorrhage. eliosis hepatis is an uncommon condition characterized by blood-filled cystic cavities in the liver. The clinical presentation is quite variable from an asymptomatic presentation to hepatic failure, portal hypertension or fatal intraabdominal hemorrhage. The exact incidence of intrahepatic or intraperitoneal hemorrhage by liver rupture has not been determined in the literature and these complications have been demonstrated only in the form of about 20 case reports. On angiography, peliosis hepatis can be suspected by multiple small contrast accumulations that become distinct during the parenchymal phase and are persistent during the venous phase. Examinations using multidetector CT (MDCT) scanners, which provide thin-section, contrast-enhanced dynamic images, are increasing nowadays. Thus, this entity has a better chance to be incidentally encountered and to be a diagnostic challenge to the radiologists. In this report, we present a case of peliosis hepatis with hemorrhagic necrosis that was complicated by massive intrahepatic bleeding and rupture. We demonstrate the imaging findings with emphasis on the contrast-enhanced dynamic MDCT features as well as the clinical outcome after treatment

  20. Peliosis Hepatis with Hemorrhagic Necrosis and Rupture: a Case Report with Emphasis on the Multi-Detector CT Findings

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Eun-A; Yoon, Kwon-Ha; Jeon, Se-Jung; Cai, Quan-Yu; Lee, Young-Whan [Wonkwang University School of Medicine, Iksan (Korea, Republic of)

    2007-02-15

    We demonstrate the imaging findings, with emphasis on the triphasic, contrast-enhanced multidetector CT findings, as well as reporting the clinical outcome in a case of peliosis hepatis with fatal hemorrhage. eliosis hepatis is an uncommon condition characterized by blood-filled cystic cavities in the liver. The clinical presentation is quite variable from an asymptomatic presentation to hepatic failure, portal hypertension or fatal intraabdominal hemorrhage. The exact incidence of intrahepatic or intraperitoneal hemorrhage by liver rupture has not been determined in the literature and these complications have been demonstrated only in the form of about 20 case reports. On angiography, peliosis hepatis can be suspected by multiple small contrast accumulations that become distinct during the parenchymal phase and are persistent during the venous phase. Examinations using multidetector CT (MDCT) scanners, which provide thin-section, contrast-enhanced dynamic images, are increasing nowadays. Thus, this entity has a better chance to be incidentally encountered and to be a diagnostic challenge to the radiologists. In this report, we present a case of peliosis hepatis with hemorrhagic necrosis that was complicated by massive intrahepatic bleeding and rupture. We demonstrate the imaging findings with emphasis on the contrast-enhanced dynamic MDCT features as well as the clinical outcome after treatment.

  1. Gastric stromal tumor: two-phase dynamic CT findings with water as oral contrast agents

    International Nuclear Information System (INIS)

    Lee, Se Hyo; Cho, June Sik; Shin, Kyung Sook; Jeong, Ki Ho; Park, Jin Yong; Yu, Ho Jun; Kim, Young Min; Jeon, Kwang Jin

    2000-01-01

    To evaluate two-phase dynamic CT with water as oral contrast agents in the CT diagnosis of gastric stromal tumors. We retrospectively reviewed the CT findings in 21 patients with pathologically proven gastric stromal tumors. Six were found to be benign, twelve were malignant, and there were three cases of STUMP (stromal tumor uncertain malignant potential). Two-phase dynamic CT scans with water as oral contrast agents were obtained 60-70 secs (portal phase) and 3 mins (equilibrium phase) after the start of IV contrast administration. We determined the size, growth pattern, and enhancement pattern of the tumors and overlying mucosa, the presence or absence of ulceration and necrosis, tumor extent, and lymph nod and distant metastasis. The CT and pathologic findings were correlated. All six benign tumors and three STUMP were less than 5.5 cm in size, and during the portal phase showed round endogastric masses with highly enhanced, intact overlying mucosa. Twelve malignant tumors were 4.5-15.5 cm in size (mean, 11.5 cm); an endogastric mass was seen in three cases, an exogastric mass in one, and a mixed pattern in eight. On portal phase images the tumors were not significantly enhanced, but highly enhanced feeding vessels were noted in five larger tumors (greater than 10 cm). All 12 malignant tumors showed ulceration and necrosis, and interruption of overlying mucosa was clearly seen during the portal phase. We were readily able to evaluate tumor extent during this phase, and in ten malignant tumors there was no invasion of adjacent organs. Seven malignant tumors showed air density within their necrotic portion (p less than 0.05). On equilibrium phase images, all malignant tumors showed heterogeneous enhancement due to necrosis, and poorly enhanced overlying mucosa. Dynamic CT during the portal phase with water as oral contrast agents was useful for depicting the submucosal origin of gastric stromal tumors and for evaluating the extent of malignant stromal tumors. Our

  2. Chronic intestinal pseudo-obstruction in adult patients: multidetector row helical CT features

    International Nuclear Information System (INIS)

    Merlin, Aurelie; Soyer, Philippe; Boudiaf, Mourad; Hamzi, Lounis; Rymer, Roland

    2008-01-01

    Chronic intestinal pseudo-obstruction (CIPO) is a rare condition due to severe gastrointestinal motility disorder. Adult patients with CIPO experience symptoms of mechanical obstruction, but reliable clinical signs that may help distinguish between actual mechanical obstruction and CIPO are lacking. Additionally, abdominal plain films that commonly show bowel dilatation with air-fluid levels do not reach acceptable degrees of specificity to exclude actual obstruction. Therefore, most adult patients with CIPO usually undergo multiple and often fruitless surgery, often leading to repeated bowel resections before diagnosis is made. In these patients who present with abdominal signs mimicking symptoms that would warrant surgical exploration, multidetector-row helical CT (MDCT) is helpful to resolve this diagnostic dilemma. MDCT shows a diffusely distended bowel and helps to rule out a mechanical cause of obstruction, thus suggesting CIPO and obviating the need for unnecessary laparotomy. In adult patients with CIPO, MDCT may show pneumatosis intestinalis, pneumoperitoneum or intussusception. However, these conditions generally do not require surgery in patients with CIPO. This pictorial essay presents the more and less common MDCT features of CIPO in adult patients, to make the reader more familiar with this disease. (orig.)

  3. Enhancement pattern of hilar cholangiocarcinoma: Contrast-enhanced ultrasound versus contrast-enhanced computed tomography

    International Nuclear Information System (INIS)

    Xu Huixiong; Chen Lida; Xie Xiaoyan; Xie Xiaohua; Xu Zuofeng; Liu Guangjian; Lin Manxia; Wang Zhu; Lu Mingde

    2010-01-01

    Objective: To compare the enhancement pattern of hilar cholangiocarcinoma on contrast-enhanced ultrasound (CEUS) with that on contrast-enhanced computed tomography (CECT). Methods: Thirty-two consecutive patients with pathologically proven hilar cholangiocarcinomas were evaluated by both low mechanical index CEUS and CECT. The enhancement feature of the tumor, portal vein infiltration, and lesion conspicuity on them was investigated. Results: In the arterial phase, the numbers of the lesions showing hyperenhancement, isoenhancement, and hypoenhancement, were 14 (43.8%), 14 (43.8%), and 4 (12.6%), on CEUS, and 12 (37.5%), 9 (28.1%), and 11 (34.4%), on CECT (P = 0.162). In portal phase, the numbers of the lesions showing hypoenhancement, isoenhancement, and hyperenhancement were 30 (93.8%), 1 (3.1%), and 1 (3.1%), on CEUS, and 23 (71.9%), 8 (25.0%), and 1 (3.1%), on CECT (P = 0.046). The detection rates for portal vein infiltration were 84.2% (16/19) for baseline ultrasound, 89.5% (17/19) for CEUS, and 78.9% (15/19) for CECT (all P > 0.05 between every two groups). CEUS significantly improved the lesion conspicuity in comparison with CECT. CEUS and CECT made correct diagnoses in 30 (93.8%) and 25 (78.1%) lesions prior to pathological examination (P = 0.125). Conclusion: The enhancement pattern of hilar cholangiocarcinoma on CEUS was similar with that on CECT in arterial phase, whereas in portal phase hilar cholangiocarcinoma shows hypoenhancement more likely on CEUS. CEUS and CECT lead to similar results in evaluating portal vein infiltration and diagnosis of this entity.

  4. Enhancement pattern of hilar cholangiocarcinoma: Contrast-enhanced ultrasound versus contrast-enhanced computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Xu Huixiong, E-mail: xuhuixiong@hotmail.co [Department of Medical Ultrasonics, The First Affiliated Hospital, Institute of Diagnostic and Interventional Ultrasound, Sun Yat-Sen University, 58 Zhongshan Road 2, Guangzhou 510080 (China); Chen Lida; Xie Xiaoyan; Xie Xiaohua; Xu Zuofeng; Liu Guangjian; Lin Manxia; Wang Zhu [Department of Medical Ultrasonics, The First Affiliated Hospital, Institute of Diagnostic and Interventional Ultrasound, Sun Yat-Sen University, 58 Zhongshan Road 2, Guangzhou 510080 (China); Lu Mingde, E-mail: lumd@21cn.co [Department of Hepatobiliary Surgery, First Affiliated Hospital, Sun Yat-Sen University, 58 Zhongshan Road 2, Guangzhou 510080 (China)

    2010-08-15

    Objective: To compare the enhancement pattern of hilar cholangiocarcinoma on contrast-enhanced ultrasound (CEUS) with that on contrast-enhanced computed tomography (CECT). Methods: Thirty-two consecutive patients with pathologically proven hilar cholangiocarcinomas were evaluated by both low mechanical index CEUS and CECT. The enhancement feature of the tumor, portal vein infiltration, and lesion conspicuity on them was investigated. Results: In the arterial phase, the numbers of the lesions showing hyperenhancement, isoenhancement, and hypoenhancement, were 14 (43.8%), 14 (43.8%), and 4 (12.6%), on CEUS, and 12 (37.5%), 9 (28.1%), and 11 (34.4%), on CECT (P = 0.162). In portal phase, the numbers of the lesions showing hypoenhancement, isoenhancement, and hyperenhancement were 30 (93.8%), 1 (3.1%), and 1 (3.1%), on CEUS, and 23 (71.9%), 8 (25.0%), and 1 (3.1%), on CECT (P = 0.046). The detection rates for portal vein infiltration were 84.2% (16/19) for baseline ultrasound, 89.5% (17/19) for CEUS, and 78.9% (15/19) for CECT (all P > 0.05 between every two groups). CEUS significantly improved the lesion conspicuity in comparison with CECT. CEUS and CECT made correct diagnoses in 30 (93.8%) and 25 (78.1%) lesions prior to pathological examination (P = 0.125). Conclusion: The enhancement pattern of hilar cholangiocarcinoma on CEUS was similar with that on CECT in arterial phase, whereas in portal phase hilar cholangiocarcinoma shows hypoenhancement more likely on CEUS. CEUS and CECT lead to similar results in evaluating portal vein infiltration and diagnosis of this entity.

  5. Comparison of the multidetector-row computed tomography findings of IgG4-related sclerosing cholangitis and extrahepatic cholangiocarcinoma

    International Nuclear Information System (INIS)

    Yata, M.; Suzuki, K.; Furuhashi, N.; Kawakami, K.; Kawai, Y.; Naganawa, S.

    2016-01-01

    Aim: To compare the multidetector-row computed tomography (MDCT) findings of IgG4-related sclerosing cholangitis (IgG4-SC) and extrahepatic cholangiocarcinoma (EH-CCA). Materials and methods: Two radiologists who had no knowledge of the patients' clinical information retrospectively evaluated the CT findings of patients with IgG4-SC (n=33) and EH-CCA (n=39) on a consensus basis. Another radiologist measured the biliary lesions. IgG4-SC was diagnosed using the Japan Biliary Association criteria (2012) or the Mayo Clinic's HISORt criteria. EH-CCA was diagnosed based on surgical findings. Results: Compared with EH-CCA, IgG4-SC exhibited the following findings significantly more frequently: (a) wall thickening alone, (b) concentric wall thickening, (c) smooth inner margins, (d) homogeneous attenuation in the arterial phase, (e) a lesion involving the intrapancreatic bile duct, (f) smooth outer margins, (g) fully visible lumen, (h) a funnel-shaped proximal bile duct, (i) skip lesions, and (j) abnormal pancreatic findings. Conversely, (k) dual-layered attenuation in all phases was significantly more common in EH-CCA. The specificity values of parameters (e–k) were >80%. Regarding dimensions, (l) the biliary lesions were longer in IgG4-SC than in EH-CCA. (m) The diameters of the dilated proximal common bile duct and (n) the dilated proximal intrahepatic bile duct were smaller in IgG4-SC than in EH-CCA. Conclusion: A number of CT findings are useful for differentiating between IgG4-SC and EH-CCA. CT findings (e–k) are particularly useful for this purpose. - Highlights: • Some CT findings are useful for differentiating between IgG4-SC and EH-CCA. • Homogeneous attenuation in all phases was more common in IgG4-SC than in EH-CCA. • Abnormal pancreatic findings showed high sensitivity and specificity values. • Dual-layered attenuation in all phases was more common in EH-CCA than in IgG4-SC.

  6. Balancing Radiation and Contrast Media Dose in Single-Pass Abdominal Multidetector CT: Prospective Evaluation of Image Quality.

    Science.gov (United States)

    Camera, Luigi; Romano, Federica; Liccardo, Immacolata; Liuzzi, Raffaele; Imbriaco, Massimo; Mainenti, Pier Paolo; Pizzuti, Laura Micol; Segreto, Sabrina; Maurea, Simone; Brunetti, Arturo

    2015-11-01

    As both contrast and radiation dose affect the quality of CT images, a constant image quality in abdominal contrast-enhanced multidetector computed tomography (CE-MDCT) could be obtained balancing radiation and contrast media dose according to the age of the patients. Seventy-two (38 Men; 34 women; aged 20-83 years) patients underwent a single-pass abdominal CE-MDCT. Patients were divided into three different age groups: A (20-44 years); B (45-65 years); and C (>65 years). For each group, a different noise index (NI) and contrast media dose (370 mgI/mL) was selected as follows: A (NI, 15; 2.5 mL/kg), B (NI, 12.5; 2 mL/kg), and C (NI, 10; 1.5 mL/kg). Radiation exposure was reported as dose-length product (DLP) in mGy × cm. For quantitative analysis, signal-to-noise (SNR) and contrast-to-noise (CNR) ratios were calculated for both the liver (L) and the abdominal aorta (A). Statistical analysis was performed with a one-way analysis of variance. Standard imaging criteria were used for qualitative analysis. Although peak hepatic enhancement was 152 ± 16, 128 ± 12, and 101 ± 14 Hounsfield units (P contrast media dose (mL) administered were 476 ± 147 and 155 ± 27 for group A, 926 ± 291 and 130 ± 16 for group B, and 1981 ± 451 and 106 ± 15 for group C, respectively (P contrast media dose administered to patients of different age. Copyright © 2015 AUR. Published by Elsevier Inc. All rights reserved.

  7. Study on children patient dose in single-detector and multi-detector row helical computed tomography

    International Nuclear Information System (INIS)

    Lu Heqing; Zhu Guoying; Zhuo Weihai; Liu Haikuan; Guo Changyi

    2008-01-01

    Objective: To study and evaluate the radiation dose of children patient in single-detector and multi-detector row helical CT scan. Methods: The head and body CT dose index of 21 CT scanners were tested. Then the values of CTDI w , CTDI vol and DLP were calculated combining with the parameters of routine head and chest scan for children of 0-1 year old group, 5 years old group, 10 years old group and adults. The effective doses of children of every age group and adults in routine head and chest scan were subsequently estimated from effective dose per DLP by age and the calculated values of DLP. Results: CTDI per mAs is greater in the head than that in the body. In head routine scan, the effective doses of 0-1 year old group,5 years old group and 10 year old group were 2.2, 1.3 and 1.1 mSv, respectively. In chest routine scan, the effective doses of 0-1 year old group,5 years old group and 10 years old group were 5.3, 3.1 and 3.4 mSv, respectively. Effective doses to children per mAs are equally 1.8 times higher than corresponding values for adults. The CTDI vol , DLP and effective dose to children in head routine scan for MDCT were greater those that for single-detector CT and dual- detector CT. The CTDI vol , DLP and effective dose to children in chest routine scan for MDCT and dual-detector row CT were smaller than that for single-detector row CT. Conclusions: Children me more radiation risk in CT examination as compared with adults. So we should strictly abide by justification of children CT examination, and optimize the parameters of CT scan rationally in order to reduce the radiation dose to children patient as much as possible. (authors)

  8. Lung surgery assisted by multidetector-row computed tomographic simulation

    International Nuclear Information System (INIS)

    Oizumi, Hiroyuki; Endoh, Makoto; Ota, Hiroshi; Takeda, Shinichi; Suzuki, Jun; Fukaya, Ken; Chiba, Masato; Sadahiro, Mitsuaki

    2009-01-01

    We describe the benefits of lung resection simulation using multidetector computed tomography (MDCT). Since 2004, the 1.0-mm slice digital imaging and communications in medicine (DICOM) server has been used for storing data obtained using 64-row MDCT. We observed that an abnormality could not be visualized from the pleural surface in 10 nodules of 18 lesions undergoing wedge lung resection. These 10 nodules were resected through simulation using a three-dimensional (3D) volume-rendering method by considering parameters such as the position, depth, or distance from the interlobar abnormalities, etc., without the need for any marking methods. For lung lobectomy, identification of the branching structures, diameter, and length of the arteries is useful in selecting the procedure for blood vessel treatment. However, in the initial 10 patients of this series, the preoperative identification of 2 small arterial branches was unsuccessful when this method was used. Therefore, it is important to carefully examine the original data in all 3 views, id est (i.e.), axial, sagittal, and coronal views. The visualization of venous branches in affected segments and intersegmental veins has facilitated the preoperative determination of the anatomical intersegmental plane. We divided the cases of thoracoscopic lung segmentectomy into 3 groups (level 1: simple, level 2: intermediate, and level 3: complex) on the basis of the technical complexity. Only level 1 segmentectomies were performed without MDCT simulation. Further, level 2 and 3 segmentectomies could be successfully performed because of the introduction of MDCT simulation in 25 of 35 patients. Thus, this simulation technique may be useful during a thoracoscopic procedure for lung surgery. (author)

  9. Anatomic evaluation of the xiphoid process with 64-row multidetector computed tomography

    International Nuclear Information System (INIS)

    Akin, Kayihan; Kosehan, Dilek; Topcu, Adem; Koktener, Asli

    2011-01-01

    The aim of this study was to evaluate the interindividual variations of the xiphoid process in a wide adult group using 64-row multidetector computed tomography (MDCT). Included in the study were 500 consecutive patients who underwent coronary computed tomography angiography. Multiplanar reconstruction (MPR), maximum intensity projection (MIP) images on coronal and sagittal planes, and three-dimensional volume rendering (VR) reconstruction images were obtained and used for the evaluation of the anatomic features of the xiphoid process. The xiphoid process was present in all patients. The xiphoid process was deviated ventrally in 327 patients (65.4%). In 11 of these 327 patients (2.2%), ventral curving at the end of the xiphoid process resembled a hook. The xiphoid process was aligned in the same axis as the sternal corpus in 166 patients (33.2%). The tip of the xiphoid process was curved dorsally like a hook in three patients (0.6%). In four patients (0.8%), the xiphoid process exhibited a reverse S shape. Xiphoidal endings were single in 313 (62.6%) patients, double in 164 (32.8%), or triple in 23 (4.6%). Ossification of the cartilaginous xiphoid process was fully completed in 254 patients (50.8 %). In total, 171 patients (34.2%) had only one xiphoidal foramen and 45 patients (9%) had two or more foramina. Sternoxiphoidal fusion was present in 214 of the patients (42.8%). Significant interindividual variations were detected in the xiphoid process. Excellent anatomic evaluation capacity of MDCT facilitates the detection of variations of the xiphoid process as well as the whole ribcage. (orig.)

  10. Estimation of aortic time-enhancement curve in pharmacokinetic analysis. Dynamic study by multi-detector row computed tomography

    International Nuclear Information System (INIS)

    Yamaguchi, Isao; Kidoya, Eiji; Higashimura, Kyoji; Hayashi, Hiroyuki; Suzuki, Masayuki

    2007-01-01

    This paper presents an introduction to the development of software that provides a physiologic model of contrast medium enhancement by incorporating available physiologic data and contrast medium pharmacokinetics to predict an organ-specific aortic time-enhancement curve (TEC) in computed tomography (CT) with various contrast medium injection protocols in patients of various heights, weights, cardiac output levels, and so on. The physiologic model of contrast medium enhancement was composed of six compartments for early contrast enhancement pharmacokinetics. Contrast medium is injected via the antecubital vein and distributed to the right side of the heart, the pulmonary compartment, the left side of the heart, and the aorta. It then circulates back to the right side of the heart via the systemic circulation. A computer-based, compartmental model of the aortic system was generated using human physiologic parameters and six differential equations to describe the transport of contrast medium. Aortic TEC generated by the computer-based physiologic model of contrast medium enhancement showed validity and agreement with clinical data and findings published previously. A computer-based physiologic model that may help predict organ-specific CT contrast medium enhancement for different injection protocols was developed. Such a physiologic model may have multiple clinical applications. (author)

  11. Multidetector-row helical computed tomography in the evaluation of cervical spine disorders; Tomografia computadorizada multislice no diagnostico das afeccoes da coluna cervical

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    Rosemberg, Laercio Alberto; Almeida, Milena Oliveira; Rios, Adriana Martins; Garbaccio, Viviane Ladeira; Kim, Nelson Ji Tae; Daniel, Mauro Miguel; Funari, Marcelo Buarque de Gusmao [Hospital Israelita Albert Einstein, Sao Paulo, SP (Brazil). Dept. de Imagem]. E-mail: laercio@einstein.br

    2003-07-01

    Multidetector-row computed tomography (MRCT) has advantages in comparison to conventional helical computed tomography, such as reduction of study time, lower radiation doses, fewer metallic artifacts and high quality multiplanar reformatting and three dimensional reconstructions. We reviewed 150 cervical spine examinations and selected the most illustrative cases including congenital anomalies, degenerative lesions, spinal infections, neoplasms, traumatic injuries and postoperative abnormalities. The quality of multiplanar reformatting and volume reconstructions of the MRCT made the detection and evaluation of most of cases with complex anatomy easier and more precise. (author)

  12. Role of multidetector computed tomography in evaluating incidentally detected breast lesions.

    Science.gov (United States)

    Moschetta, Marco; Scardapane, Arnaldo; Lorusso, Valentina; Rella, Leonarda; Telegrafo, Michele; Serio, Gabriella; Angelelli, Giuseppe; Ianora, Amato Antonio Stabile

    2015-01-01

    Computed tomography (CT) does not represent the primary method for the evaluation of breast lesions; however, it can detect breast abnormalities, even when performed for other reasons related to thoracic structures. The aim of this study is to evaluate the potential benefits of 320-row multidetector CT (MDCT) in evaluating and differentiating incidentally detected breast lesions by using vessel probe and 3D analysis software with net enhancement value. Sixty-two breast lesions in 46 patients who underwent 320-row chest CT examination were retrospectively evaluated. CT scans were assessed searching for the presence, location, number, morphological features, and density of breast nodules. Net enhancement was calculated by subtracting precontrast density from the density obtained by postcontrast values. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and diagnostic accuracy of CT were calculated for morphological features and net enhancement. Thirty of 62 lesions were found to be malignant at histological examination and 32 were found to be benign. When morphological features were considered, the sensitivity, specificity, accuracy, PPV, and NPV of CT were 87%, 100%, 88%, 100%, and 50%, respectively. Based on net enhancement, CT reached a sensitivity, specificity, accuracy, PPV, and NPV of 100%, 94%, 97%, 94%, and 100%, respectively. MDCT allows to recognize and characterize breast lesions based on morphological features. Net enhancement can be proposed as an additional accurate feature of CT.

  13. Defining Anatomic Variants of the Coronary Artery in Taiwanese Subjects Using 64-Multidetector-Row Computed Tomography

    Directory of Open Access Journals (Sweden)

    Hung-Jung Wang

    2007-10-01

    Full Text Available The newly developed 64-multidetector-row computed tomography (MDCT prompted us to evaluate coronary angiography using this noninvasive method. We reviewed 281 images of MDCT coronary angiography in Taiwanese. The origins of the coronary arteries were identified from the luminal aspect of the aorta. We described them as seen from the aortic sinus looking toward the cardiac ventricle. The sinus facing the left ventricle was designated sinus 1, and that facing the right ventricle was designated sinus 2. Anatomic variants of the coronary artery were divided into five types according to the structure of the left anterior descending artery, right coronary artery, and left circumflex artery. Of the 281 patients, 275 (97.9% had the type I variant in which the right coronary artery originated from sinus 2. MDCT provides advantages in defining anatomic variation and helps in the planning of clinical therapy or surgery.

  14. Accuracy of multidetector row computed tomography for the detection of transplant vasculopathy: comparison with invasive coronary angiography and intravascular ultrasound

    International Nuclear Information System (INIS)

    Carrascosa, P.; Capunay, C.; Carrascosa, J.; Perrone, S.; Deviggiano, A.; Lopez, E.M.; Lev, G.; Garcia, M.J.

    2009-01-01

    Objective: To evaluate the diagnostic accuracy of multidetector computed tomography (MDCT) for detection of luminal stenosis and cardiac allograft vasculopathy in comparison with coronary angiography (CA) and intravascular ultrasound (IVUS) respectively. Material and methods: Nineteen cardiac transplant patients scheduled for follow-up CA were included. MDCT coronary angiography was performed using a 16-row CT scanner within 7-14 days after CA and IVUS. Studies were analyzed by independent readers; two observers evaluated the CT datasets for the presence of coronary artery stenosis > 50% and allograft vasculopathy. Results: The sensitivity for detecting > 50% luminal stenosis was 80-88% and specificity, 98-99% and for detection of cardiac allograft vasculopathy, the sensitivity was 91-96% and specificity, 88-91%. Conclusion: In this preliminary series, our results indicate that MDCT coronary angiography was capable of detecting both significant coronary stenosis as well as diffuse intimal proliferation. This non-invasive procedure could be an alternative to CA and IVUS in the surveillance of heart transplant patients. (authors) [es

  15. Aortoiliac stenooculusive disease and aneurysms. Screening with non-contrast enhanced two-dimensional cardiac gated cine phase contrast MR angiography with multiple velocity encoded values and cardiac gated two-dimensional time-of-flight MR angiography

    International Nuclear Information System (INIS)

    Naganawa, Shinji; Koshikawa, Tokiko; Kato, Katsuhiko

    2001-01-01

    To evaluate the performance of two-dimensional cine phase contrast MRA with multi-velocity encoded values (multi-VENC cine PC) and ECG-gated two-dimensional time-of-flight MRA (ECG-2D-TOF) for the detection of stenoocclusive lesions and aneurysms in the aortoiliac area, when each method was used individually and when the two methods were used together. Forty-one patients were included in this study. Multi-VENC cine PC and ECG-2D-TOF were obtained first, then contrast enhanced three-dimensional magnetic resonance angiography (CE-3D-MRA) was performed as the standard of reference. Two observers reviewed the images separately without knowledge of patients' symptoms or histories. Sensitivities and specificities were obtained separately for stenooclusive lesions and aneurysms by two reviewers. When the two methods were applied together, high sensitivities (93.0 by observer 1 and 91.9% by observer 2) and adequate specificities (87.6 and 82.3%) were obtained for stenoocclusive lesions. For aneurysms, moderate to high sensitivities (91.1 and 71.1%) and high specificities (98.8 and 99.4%) were obtained. These results suggest that the performance of two non-contrast enhanced MRA techniques may be valuable as a screening tool when the two methods are applied together. (author)

  16. Automatic assessment of coronary artery calcium score from contrast-enhanced 256-row coronary computed tomography angiography.

    Science.gov (United States)

    Rubinshtein, Ronen; Halon, David A; Gaspar, Tamar; Lewis, Basil S; Peled, Nathan

    2014-01-01

    The coronary artery calcium score (CS), an independent predictor of cardiovascular events, can be obtained from a stand-alone nonenhanced computed tomography (CT) scan (CSCT) or as an additional nonenhanced procedure before contrast-enhanced coronary CT angiography (CCTA). We evaluated the accuracy of a novel fully automatic tool for computing CS from the CCTA examination. One hundred thirty-six consecutive symptomatic patients (aged 59 ± 11 years, 40% female) without known coronary artery disease who underwent both 256-row CSCT and CCTA were studied. Original scan reconstruction (slice thickness) was maintained (3 mm for CSCT and 0.67 mm for CCTA). CS was computed from CCTA by an automatic tool (COR Analyzer, rcadia Medical Imaging, Haifa, Israel) and compared with CS results obtained by standard assessment of nonenhanced CSCT (HeartBeat CS, Philips, Cleveland, Ohio). We also compared both methods for classification into 5 commonly used CS categories (0, 1 to 10, 11 to 100, 101 to 400, >400 Agatston units). All scans were of diagnostic quality. CS obtained by the COR Analyzer from CCTA classified 111 of 136 (82%) of patients into identical categories as CS by CSCT and 24 of remaining 25 into an adjacent category. Overall, CS values from CCTA showed high correlation with CS values from CSCT (Spearman rank correlation = 0.95, p automatically computed from 256-row CCTA correlated highly with standard CS values obtained from nonenhanced CSCT. CS obtained directly from CCTA may obviate the need for an additional scan and attendant radiation. Copyright © 2014 Elsevier Inc. All rights reserved.

  17. 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.

  18. Data explosion: the challenge of multidetector-row CT

    International Nuclear Information System (INIS)

    Rubin, Geoffrey D.

    2000-01-01

    The development of multi detector-row CT has brought many exciting advancements to clinical CT scanning. While multi detector-row CT offers unparalleled speed of acquisition, spatial resolution, and anatomic coverage, a challenge presented by these advantages is the substantial increase on the number of reconstructed cross-sections that are rapidly created and in need of analysis. This manuscript discusses currently available alternative visualization techniques for the assessment of volumetric data acquired with multi detector-row CT. Although the current capabilities of 3-D workstations offer many possibilities for alternative analysis of MCDT data, substantial improvements both in automated processing, processing speed and user interface will be necessary to realize the vision of replacing the primary analysis of transverse reconstruction's with alternative analyses. The direction that some of these future developments might take are discussed

  19. Patent foramen ovale: detection with nongated multidetector CT.

    Science.gov (United States)

    Revel, Marie-Pierre; Faivre, Jean-Baptiste; Letourneau, Thierry; Henon, Hilde; Leys, Didier; Delannoy-Deken, Valérie; Remy-Jardin, Martine; Remy, Jacques

    2008-10-01

    To evaluate nongated multidetector computed tomography (CT) in the detection of patent foramen ovale (PFO) and atrial septal aneurysm (ASA) in comparison with transesophageal echocardiography (TEE). The study was approved by the institutional review board, and informed consent was obtained from all patients. One hundred five patients (57 men, 48 women; mean age, 53 years) with a recent stroke underwent TEE and multidetector CT on the same day. After injection of a diluted iodinated contrast material, a series of 2.4-mm-thick transverse images centered on the fossa ovalis were acquired in conjunction with release of the Valsalva maneuver. Two independent radiologists considered PFO present if left atrial enhancement was detected visually before enhancement of the pulmonary veins or if an early peak of left atrial enhancement was found at time-attenuation curve analysis. PFO was detected with 98% specificity (95% confidence interval [CI]: 0.91, 0.99). Overall sensitivity was 55% (95% CI: 0.38, 0.70), ranging from 28% for shunts classified as grade 1 at TEE to 91% for those classified as grade 4 at TEE. Interreader agreement was good (kappa = 0.81). Visual assessment was better than time-attenuation curve analysis, which enabled detection of only 15 of the 40 cases of PFO. Multidetector CT depicted only 22% of cases of ASA. The mean effective radiation dose was 2.3 mSv. Nongated multidetector CT can be used to diagnose high-grade shunts through a PFO, with 91% sensitivity and 98% specificity. Thus, PFO detection, in addition to routine CT evaluation of the lungs, could be indicated in patients with unexplained hypoxemia. (c) RSNA, 2008.

  20. Clinical usefulness of multidetector-row CT to evaluate coronary artery calcium score in type 2 diabetes

    International Nuclear Information System (INIS)

    Nishioka, Makiko; Sakuma, Toru; Sano, Hironari; Utsunomiya, Kazunori; Agata, Toshihiko; Shimizu, Keisuke; Tajima, Naoko

    2004-01-01

    According to recent studies, multidetector-row CT (MDCT) with a retrospective electrocardiogram (ECG)-gating reconstruction algorithm shows a high correlation with coronary artery calcium score determined using electron-beam CT. Diabetes leads to many macrovascular complications, including coronary artery disease. The aim of this study was to evaluate risk factors for cardiac macroangiopathy in type 2 diabetes using MDCT. An observational cross-sectional study was performed in 90 patients with diabetes mellitus. Coronary calcium data was acquired by MDCT (SOMATOM Volume Zoom, Siemens AG, Medical Solutions, Germany). Physical examinations, laboratory data, glycemic control, and control of other risk factors were analyzed. The coronary artery calcium score increased with age. Multivariant analysis revealed that the coronary calcium score was closely correlated with electrocardiogram evaluation and control of hypertension. Coronary artery calcium score as determined by MDCT can be used as a screening radiological examination for cardiac macroangiopathy in diabetes patients with electrocardiogram abnormality and hypertension. (author)

  1. Data explosion: the challenge of multidetector-row CT

    Energy Technology Data Exchange (ETDEWEB)

    Rubin, Geoffrey D. E-mail: grubin@standford.edu

    2000-11-01

    The development of multi detector-row CT has brought many exciting advancements to clinical CT scanning. While multi detector-row CT offers unparalleled speed of acquisition, spatial resolution, and anatomic coverage, a challenge presented by these advantages is the substantial increase on the number of reconstructed cross-sections that are rapidly created and in need of analysis. This manuscript discusses currently available alternative visualization techniques for the assessment of volumetric data acquired with multi detector-row CT. Although the current capabilities of 3-D workstations offer many possibilities for alternative analysis of MCDT data, substantial improvements both in automated processing, processing speed and user interface will be necessary to realize the vision of replacing the primary analysis of transverse reconstruction's with alternative analyses. The direction that some of these future developments might take are discussed.

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

    International Nuclear Information System (INIS)

    Heyer, C.M.; Nicolas, V.

    2005-01-01

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

  3. Quantitative investigation of the edge enhancement in in-line phase contrast projections and tomosynthesis provided by distributing microbubbles on the interface between two tissues: a phantom study

    Science.gov (United States)

    Wu, Di; Donovan Wong, Molly; Li, Yuhua; Fajardo, Laurie; Zheng, Bin; Wu, Xizeng; Liu, Hong

    2017-12-01

    The objective of this study was to quantitatively investigate the ability to distribute microbubbles along the interface between two tissues, in an effort to improve the edge and/or boundary features in phase contrast imaging. The experiments were conducted by employing a custom designed tissue simulating phantom, which also simulated a clinical condition where the ligand-targeted microbubbles are self-aggregated on the endothelium of blood vessels surrounding malignant cells. Four different concentrations of microbubble suspensions were injected into the phantom: 0%, 0.1%, 0.2%, and 0.4%. A time delay of 5 min was implemented before image acquisition to allow the microbubbles to become distributed at the interface between the acrylic and the cavity simulating a blood vessel segment. For comparison purposes, images were acquired using three system configurations for both projection and tomosynthesis imaging with a fixed radiation dose delivery: conventional low-energy contact mode, low-energy in-line phase contrast and high-energy in-line phase contrast. The resultant images illustrate the edge feature enhancements in the in-line phase contrast imaging mode when the microbubble concentration is extremely low. The quantitative edge-enhancement-to-noise ratio calculations not only agree with the direct image observations, but also indicate that the edge feature enhancement can be improved by increasing the microbubble concentration. In addition, high-energy in-line phase contrast imaging provided better performance in detecting low-concentration microbubble distributions.

  4. Minimizing Contrast Medium Doses to Diagnose Pulmonary Embolism with 80-kVp Multidetector Computed Tomography in Azotemic Patients

    Energy Technology Data Exchange (ETDEWEB)

    Holmquist, F. (Dept. of Diagnostic Radiology, Malmoe Univ. Hospital, Univ. of Lund, Malmoe (Sweden)); Hansson, K.; Pasquariello, F. (Dept. of Internal Medicine, Lasarettet Trelleborg, Univ. of Lund, Trelleborg (Sweden)); Bjoerk, J. (Competence Center for Clinical Research, Univ. Hospital, Univ. of Lund, Lund (Sweden)); Nyman, U. (Dept. of Radiology, Lasarettet Trelleborg, Univ. of Lund, Trelleborg (Sweden))

    2009-02-15

    Background: In diagnosing acute pulmonary embolism (PE) in azotemic patients, scintigraphy and magnetic resonance imaging are frequently inconclusive or not available in many hospitals. Computed tomography is readily available, but relatively high doses (30-50 g I) of potentially nephrotoxic iodine contrast media (CM) are used. Purpose: To report on the diagnostic quality and possible contrast-induced nephropathy (CIN) after substantially reduced CM doses to diagnose PE in azotemic patients using 80-peak kilovoltage (kVp) 16-row multidetector computed tomography (MDCT) combined with CM doses tailored to body weight, fixed injection duration adapted to scan time, automatic bolus tracking, and saline chaser. Material and Methods: Patients with estimated glomerular filtration rate (eGFR) <50 ml/min were scheduled to undergo 80-kVp MDCT using 200 mg I/kg, and those with eGFR =50 ml/min, 120-kVp MDCT with 320 mg I/kg. Both protocols used an 80-kg maximum dose weight and a fixed 15-s injection time. Pulmonary artery density and contrast-to-noise ratio were measured assuming 70 Hounsfield units (HU) for a fresh clot. CIN was defined as a plasma creatinine rise >44.2 mumol/l from baseline. Results: 89/148 patients (63/68 females) underwent 80-/120-kVp protocols, respectively, with 95% of the examinations being subjectively excellent or adequate. Mean values in the 80-/120-kVp cohorts regarding age were 82/65 years, body weight 66/78 kg, effective mAs 277/117, CM dose 13/23 g I, pulmonary artery density 359/345 HU, image noise (1 standard deviation) 24/21 HU, contrast-to-noise ratio 13/13, and dose-length product 173/258 mGycm. Only 1/65 and 2/119 patients in the 80- and 120-kVp cohorts, respectively, with negative CT and no anticoagulation suffered non-fatal thromboembolism during 3-month follow-up. No patient developed CIN. Conclusion: 80-kVp 16-row MDCT with optimization of injection parameters may be performed with preserved diagnostic quality, using markedly reduced CM

  5. Multidetector-row CT of right hemidiaphragmatic rupture caused by blunt trauma: a review of 12 cases

    International Nuclear Information System (INIS)

    Rees, O.; Mirvis, S.E.; Shanmuganathan, K.

    2005-01-01

    AIM: To determine the usefulness of multidetector-row CT (MDCT) with multiplanar reformatted (MPR) images in the sagittal and coronal plane in diagnosing acute right hemidiaphragmatic rupture. MATERIALS AND METHODS: Twelve patients were identified who received chest and abdominal MDCT after major blunt trauma diagnosed with right diaphragmatic injury. Sagittal and coronal reformations were performed in all cases. The images were retrospectively reviewed by two experienced radiologists for signs of right diaphragm injury, such as direct diaphragm discontinuity, the 'collar sign', the 'dependent viscera sign', and intra-thoracic location of herniated abdominal contents. RESULTS: Of the 12 cases of right hemidiaphragm rupture, diaphragm discontinuity was seen in seven (58%) cases, the collar sign in five (42%), the dependent viscera sign in four (33%), and transdiaphragmatic herniation of the right colon and fat in another. Two variants of the collar sign were apparent on high-quality sagittal and coronal reformations. The first, termed the 'hump sign', describes a rounded portion of liver herniating through the diaphragm forming a hump-shaped mass, and the second, termed the 'band sign,' is a linear lucency across the liver along the torn edges of the hemidiaphragm. The hump sign occurred in 10 (83%) patients and the band sign in four (33%). CONCLUSION: MDCT is very useful in the diagnosis of right hemidiaphragm injury caused by blunt trauma when sagittal and coronal reformatted images are obtained, and should allow more frequent preoperative diagnosis

  6. 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.)

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

    International Nuclear Information System (INIS)

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

    2007-01-01

    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. (orig.)

  8. MDCT appearance of the appendix: how does the low-density barium sulfate oral contrast agent affect it?

    Science.gov (United States)

    Yaghmai, Vahid; Aghaei-Lasboo, Anahita; Brandwein, Warren M; Tochetto, Sandra; Mafi, John N; Miller, Frank H; Nikolaidis, Paul

    2011-01-01

    We compared the effect of low-density barium sulfate neutral oral contrast agent on the diameter of normal appendix and its luminal content versus that of water on multidetector-row CT. CT scans of 24 patients who had been imaged on two separate occasions for the evaluation of pancreatic pathology, once with water and subsequently with low-density barium sulfate as the neutral oral contrast agent were evaluated (total of 48 scans). Studies were randomized and reviewed in consensus on a workstation in the stack mode by two radiologists blinded to the type of oral contrast. The appendix was measured at baseline and 10 days later to obtain an average diameter. Results of the water and low-density barium sulfate groups were compared using paired t test. Contents of the appendiceal lumen were also noted (gas, fluid, mixed, and collapsed appendix). The average diameter of the appendix for scans obtained with water and low-density barium sulfate was 4.09 ± 0.87 mm (median, 4.22 mm; range, 2.50-5.65 mm) and 4.13 ± 0.93 mm (median, 4 mm, range, 2.2-5.65 mm), respectively. This difference was not statistically significant (P = 0.69). There was no statistically significant difference in the appendiceal content when water or low-density barium sulfate were used as oral contrast (χ (2) = 4.25, P = 0.89). Low-density barium sulfate does not affect appendiceal content or diameter and, therefore, should not adversely affect evaluation of the appendix on multidetector row CT.

  9. Enhanced phase contrast transfer using ptychography combined with a pre-specimen phase plate in a scanning transmission electron microscope

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Hao; Ercius, Peter [Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Nellist, Peter D. [Department of Materials, University of Oxford, Parks Road, Oxford OX1 3PH (United Kingdom); Ophus, Colin, E-mail: clophus@lbl.gov [Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States)

    2016-12-15

    The ability to image light elements in both crystalline and noncrystalline materials at near atomic resolution with an enhanced contrast is highly advantageous to understand the structure and properties of a wide range of beam sensitive materials including biological specimens and molecular hetero-structures. This requires the imaging system to have an efficient phase contrast transfer at both low and high spatial frequencies. In this work we introduce a new phase contrast imaging method in a scanning transmission electron microscope (STEM) using a pre-specimen phase plate in the probe forming aperture, combined with a fast pixelated detector to record diffraction patterns at every probe position, and phase reconstruction using ptychography. The phase plate significantly enhances the contrast transfer of low spatial frequency information, and ptychography maximizes the extraction of the phase information at all spatial frequencies. In addition, the STEM probe with the presence of the phase plate retains its atomic resolution, allowing simultaneous incoherent Z-contrast imaging to be obtained along with the ptychographic phase image. An experimental image of Au nanoparticles on a carbon support shows high contrast for both materials. Multislice image simulations of a DNA molecule shows the capability of imaging soft matter at low dose conditions, which implies potential applications of low dose imaging of a wide range of beam sensitive materials. - Highlights: • This work demonstrates a phase contrast imaging method by combining a pre-specimen phase plate with ptychogrpahy. • This method is shown to have a high phase contrast transfer efficiency at both low and high spatial frequencies. • Unlike CTEM which uses a heavy defocus to gain contrast, the phase plate gives a linear phase contrast at zero defocus aberrations. • Image simulations of DNA suggest this method is highly attractive for imaging beam sensitive materials at a low dose.

  10. Phase-contrast enhanced mammography: A new diagnostic tool for breast imaging

    International Nuclear Information System (INIS)

    Wang Zhentian; Thuering, Thomas; David, Christian; Roessl, Ewald; Trippel, Mafalda; Kubik-Huch, Rahel A.; Singer, Gad; Hohl, Michael K.; Hauser, Nik; Stampanoni, Marco

    2012-01-01

    Phase contrast and scattering-based X-ray imaging can potentially revolutionize the radiological approach to breast imaging by providing additional and complementary information to conventional, absorption-based methods. We investigated native, non-fixed whole breast samples using a grating interferometer with an X-ray tube-based configuration. Our approach simultaneously recorded absorption, differential phase contrast and small-angle scattering signals. The results show that this novel technique - combined with a dedicated image fusion algorithm - has the potential to deliver enhanced breast imaging with complementary information for an improved diagnostic process.

  11. Phase-contrast enhanced mammography: A new diagnostic tool for breast imaging

    Energy Technology Data Exchange (ETDEWEB)

    Wang Zhentian; Thuering, Thomas; David, Christian; Roessl, Ewald; Trippel, Mafalda; Kubik-Huch, Rahel A.; Singer, Gad; Hohl, Michael K.; Hauser, Nik; Stampanoni, Marco [Swiss Light Source, Paul Scherrer Institut, 5232 Villigen (Switzerland); Laboratory for Micro and Nanotechnology, Paul Scherrer Institut, 5232 Villigen (Switzerland); Philips Technologie GmbH, Roentgenstrasse 24, 22335 Hamburg (Germany); Institute of Pathology, Kantonsspital Baden, 5404 Baden (Switzerland); Department of Radiology, Kantonsspital Baden, 5404 Baden (Switzerland); Institute of Pathology, Kantonsspital Baden, 5404 Baden (Switzerland); Department of Gynecology and Obstetrics, Interdisciplinary Breast Center Baden, Kantonsspital Baden, 5404 Baden (Switzerland); Swiss Light Source, Paul Scherrer Institut, 5232 Villigen, Switzerland and Institute for Biomedical Engineering, University and ETH Zuerich, 8092 Zuerich (Switzerland)

    2012-07-31

    Phase contrast and scattering-based X-ray imaging can potentially revolutionize the radiological approach to breast imaging by providing additional and complementary information to conventional, absorption-based methods. We investigated native, non-fixed whole breast samples using a grating interferometer with an X-ray tube-based configuration. Our approach simultaneously recorded absorption, differential phase contrast and small-angle scattering signals. The results show that this novel technique - combined with a dedicated image fusion algorithm - has the potential to deliver enhanced breast imaging with complementary information for an improved diagnostic process.

  12. 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

  13. Diagnosis value of dual-phase contrast enhancement CT combined with virtual non-enhanced images by dual-energy CT in clear cell renal cell carcinoma

    International Nuclear Information System (INIS)

    Ma Zhoupeng; Zhou Jianjun; Liu Xueling; Wang Chun; Zhang Shunzhuang

    2012-01-01

    Objective: To explore the diagnostic value of dual-phase contrast enhancement CT combined with virtual non-enhanced images by dual-energy CT in clear cell renal cell carcinoma. Methods: Sixty patients who were suspected of clear cell renal cell carcinoma underwent non-enhanced CT and contrast enhancement CT of early interface-phase between cortex -medulla and parenchymal phase on a dual-energy CT. The true non-enhanced kidney CT (TNCT) was performed in a single-energy acquisition mode, but the dual-phase contrast enhancement CT were performed in a dual-energy mode of 80 kV and 140 kV respectively. The virtual non-enhanced CT (VNCT) images were derived from the data of early interface phase using liver virtual non-contrast software. The diagnose according to VNCT combined dual-phase contrast enhancement CT and dual-phase contrast enhancement CT only were made respectively and compared with χ 2 test. Between the true non-contrast CT and the virtual non-contrast CT, the image quality was compared with Wilcoxon test; The radiation dose of volume CT dose index (CTDIvol) and dose length product(DLP) in a single-phase and total examination, the mean CT HU values of the tumours were compared with t test. Results: The accuracy of VNCT combined dual-phase contrast enhancement CT was higher than that of dual-phase contrast enhancement CT only [93.3% (56/60) vs.78.3% (47/60); χ 2 =5.6, P<0.05]. The detective ability (score) of VNCT was near to that of TNCT and the difference was not obvious (Z=0.00, P>0.05). The radiation dose of volume CT dose index (CTDIvol) and dose length product (DLP) in a single phase and total examination of VNCT [(8.85 ± 1.28) mGy, (196.45 ±21.12) mGy·cm, (17.69±2.35) mGy, (392.90±42.25) mGy · cm] were lower than that of TNCT [(10.20 ± 1.44) mGy,(218.29 ± 29.60) mGy · cm, (30.61 ± 3.27) mGy and (654.86 ± 88.81) mGy ·cm], t=4.21, 3.58, 23.63, 16.12 respectively, P<0.05. The mean CT HU values of tumours on VNCT images was higher than that

  14. Multidetector-row computed tomography for prosthetic heart valve dysfunction: is concomitant non-invasive coronary angiography possible before redo-surgery?

    Energy Technology Data Exchange (ETDEWEB)

    Tanis, Wilco [Haga Teaching Hospital, Department of Cardiology, The Hague (Netherlands); Haga Teaching Hospital, The Hague (Netherlands); Sucha, Dominika; Habets, Jesse [University Medical Center Utrecht, Department of Radiology, Utrecht (Netherlands); Laufer, Ward; Chamuleau, Steven [University Medical Center Utrecht, Department of Cardiology, Utrecht (Netherlands); Herwerden, Lex.A. van [University Medical Center Utrecht, Department of Cardiothoracic Surgery, Utrecht (Netherlands); Symersky, Petr [Vrije Universiteit, Department of Cardiothoracic Surgery, Amsterdam (Netherlands); Budde, Ricardo P.J. [Erasmus Medical Center, Department of Radiology, Rotterdam (Netherlands)

    2015-06-01

    Retrospective ECG-gated multidetector-row computed tomography (MDCT) is increasingly used for the assessment of prosthetic heart valve (PHV) dysfunction, but is also hampered by PHV-related artefacts/cardiac arrhythmias. Furthermore, it is performed without nitroglycerine or heart rate correction. The purpose was to determine whether MDCT performed before potential redo-PHV surgery is feasible for concomitant coronary artery stenosis assessment and can replace invasive coronary angiography (CAG). PHV patients with CAG and MDCT were identified. Based on medical history, two groups were created: (I) patients with no known coronary artery disease (CAD), (II) patients with known CAD. All images were scored for the presence of significant (>50 %) stenosis. CAG was the reference test. Fifty-one patients were included. In group I (n = 38), MDCT accurately ruled out significant stenosis in 19/38 (50 %) patients, but could not replace CAG in the remaining 19/38 (50 %) patients due to non-diagnostic image quality (n = 16) or significant stenosis (n = 3) detection. In group II (n = 13), MDCT correctly found no patients without significant stenosis, requiring CAG imaging in all. MDCT assessed patency in 16/19 (84 %) grafts and detected a hostile anatomy in two. MDCT performed for PHV dysfunction assessment can replace CAG (100 % accurate) in approximately half of patients without previously known CAD. (orig.)

  15. Multidetector-row computed tomography for prosthetic heart valve dysfunction: is concomitant non-invasive coronary angiography possible before redo-surgery?

    International Nuclear Information System (INIS)

    Tanis, Wilco; Sucha, Dominika; Habets, Jesse; Laufer, Ward; Chamuleau, Steven; Herwerden, Lex.A. van; Symersky, Petr; Budde, Ricardo P.J.

    2015-01-01

    Retrospective ECG-gated multidetector-row computed tomography (MDCT) is increasingly used for the assessment of prosthetic heart valve (PHV) dysfunction, but is also hampered by PHV-related artefacts/cardiac arrhythmias. Furthermore, it is performed without nitroglycerine or heart rate correction. The purpose was to determine whether MDCT performed before potential redo-PHV surgery is feasible for concomitant coronary artery stenosis assessment and can replace invasive coronary angiography (CAG). PHV patients with CAG and MDCT were identified. Based on medical history, two groups were created: (I) patients with no known coronary artery disease (CAD), (II) patients with known CAD. All images were scored for the presence of significant (>50 %) stenosis. CAG was the reference test. Fifty-one patients were included. In group I (n = 38), MDCT accurately ruled out significant stenosis in 19/38 (50 %) patients, but could not replace CAG in the remaining 19/38 (50 %) patients due to non-diagnostic image quality (n = 16) or significant stenosis (n = 3) detection. In group II (n = 13), MDCT correctly found no patients without significant stenosis, requiring CAG imaging in all. MDCT assessed patency in 16/19 (84 %) grafts and detected a hostile anatomy in two. MDCT performed for PHV dysfunction assessment can replace CAG (100 % accurate) in approximately half of patients without previously known CAD. (orig.)

  16. Improved vessel morphology measurements in contrast-enhanced multi-detector computed tomography coronary angiography with non-linear post-processing

    International Nuclear Information System (INIS)

    Ferencik, Maros; Lisauskas, Jennifer B.; Cury, Ricardo C.; Hoffmann, Udo; Abbara, Suhny; Achenbach, Stephan; Karl, W. Clem; Brady, Thomas J.; Chan, Raymond C.

    2006-01-01

    Multi-detector computed tomography (MDCT) permits detection of coronary plaque. However, noise and blurring impair accuracy and precision of plaque measurements. The aim of the study was to evaluate MDCT post-processing based on non-linear image deblurring and edge-preserving noise suppression for measurements of plaque size. Contrast-enhanced MDCT coronary angiography was performed in four subjects (mean age 55 ± 5 years, mean heart rate 54 ± 5 bpm) using a 16-slice scanner (Siemens Sensation 16, collimation 16 x 0.75 mm, gantry rotation 420 ms, tube voltage 120 kV, tube current 550 mAs, 80 mL of contrast). Intravascular ultrasound (IVUS; 40 MHz probe) was performed in one vessel in each patient and served as a reference standard. MDCT vessel cross-sectional images (1 mm thickness) were created perpendicular to centerline and aligned with corresponding IVUS images. MDCT images were processed using a deblurring and edge-preserving noise suppression algorithm. Then, three independent blinded observers segmented lumen and outer vessel boundaries in each modality to obtain vessel cross-sectional area and wall area in the unprocessed MDCT cross-sections, post-processed MDCT cross-sections and corresponding IVUS. The wall area measurement difference for unprocessed and post-processed MDCT images relative to IVUS was 0.4 ± 3.8 mm 2 and -0.2 ± 2.2 mm 2 (p 2 , respectively. In conclusion, MDCT permitted accurate in vivo measurement of wall area and vessel cross-sectional area as compared to IVUS. Post-processing to reduce blurring and noise reduced variability of wall area measurements and reduced measurement bias for both wall area and vessel cross-sectional area

  17. Assessment of the kidney tumor vascular supply by two-phase MDCT-angiography

    Energy Technology Data Exchange (ETDEWEB)

    Ferda, Jiri [Department of Radiology, Charles University Hospital Plzen, Alej Svobody 80, CZ-306 40 Plzen (Czech Republic)]. E-mail: ferda@fnplzen.cz; Hora, Milan [Department of Urology, Charles University Hospital Plzen, Dr. Edvarda Benese 13, CZ-306 40 Plzen (Czech Republic); Hes, Ondrej [Institute of Pathology, Charles University Hospital Plzen, Alej Svobody 80, CZ-306 40 Plzen (Czech Republic); Ferdova, Eva [Department of Radiology, Charles University Hospital Plzen, Alej Svobody 80, CZ-306 40 Plzen (Czech Republic); Kreuzberg, Boris [Department of Radiology, Charles University Hospital Plzen, Alej Svobody 80, CZ-306 40 Plzen (Czech Republic)

    2007-05-15

    Purpose: Current kidney surgery uses less invasive laparoscopic and nephron-sparring procedures. Thus, perfect imaging of the renal vasculature is essential for surgery planning. The aim of our retrospective study was to evaluate the accuracy of 16-detector-row CT-angiography in assessing the vascular anatomy of the kidney with a tumor. Subjects and methods: Referred for computed tomography (CT) because of a suspected renal tumor, 50 consecutive patients (mean age 58.6 years; range 43-82) were enrolled into our retrospective study. All examinations were performed with 16 x 0.75 mm collimation after the intravenous application of 80 ml of a non-ionic contrast material. The imaging protocol contained two-phase scanning in the arterial and then in the venous phase. The vascular anatomy of the kidney with tumor was evaluated using volume rendered (VRT) and maximum intensity images (MIP). Findings were compared with the anatomy found during surgery. Results: Forty-seven patients underwent nephrectomy, with an advanced clinical stage (IV) found in the three remaining ones. Correct topography of the renal hilus, including a number of arteries and veins, and the anatomy of their branching, was described in 46 patients. A very small upper polar artery was overlooked in one patient. The accuracy for the only-arterial was 97.9% and only-venous anatomy was 100%. The parasitic vasculature of the tumor was discovered in 10 cases and all of them were confirmed by surgery (100% accuracy). Macroscopic intravenous spread of the tumor was discovered in two cases, but microscopic intravenous invasion was confirmed during histology of the kidney specimens in another two cases, the overall tumor staging accuracy reaching 95.7%. Conclusion: Two-phase multidetector CT is a valuable tool for assessing vascular supply of the kidney before surgery due to the tumor and can fully replace catheter-based angiography.

  18. Assessment of the kidney tumor vascular supply by two-phase MDCT-angiography

    International Nuclear Information System (INIS)

    Ferda, Jiri; Hora, Milan; Hes, Ondrej; Ferdova, Eva; Kreuzberg, Boris

    2007-01-01

    Purpose: Current kidney surgery uses less invasive laparoscopic and nephron-sparring procedures. Thus, perfect imaging of the renal vasculature is essential for surgery planning. The aim of our retrospective study was to evaluate the accuracy of 16-detector-row CT-angiography in assessing the vascular anatomy of the kidney with a tumor. Subjects and methods: Referred for computed tomography (CT) because of a suspected renal tumor, 50 consecutive patients (mean age 58.6 years; range 43-82) were enrolled into our retrospective study. All examinations were performed with 16 x 0.75 mm collimation after the intravenous application of 80 ml of a non-ionic contrast material. The imaging protocol contained two-phase scanning in the arterial and then in the venous phase. The vascular anatomy of the kidney with tumor was evaluated using volume rendered (VRT) and maximum intensity images (MIP). Findings were compared with the anatomy found during surgery. Results: Forty-seven patients underwent nephrectomy, with an advanced clinical stage (IV) found in the three remaining ones. Correct topography of the renal hilus, including a number of arteries and veins, and the anatomy of their branching, was described in 46 patients. A very small upper polar artery was overlooked in one patient. The accuracy for the only-arterial was 97.9% and only-venous anatomy was 100%. The parasitic vasculature of the tumor was discovered in 10 cases and all of them were confirmed by surgery (100% accuracy). Macroscopic intravenous spread of the tumor was discovered in two cases, but microscopic intravenous invasion was confirmed during histology of the kidney specimens in another two cases, the overall tumor staging accuracy reaching 95.7%. Conclusion: Two-phase multidetector CT is a valuable tool for assessing vascular supply of the kidney before surgery due to the tumor and can fully replace catheter-based angiography

  19. Multidetector row computed tomography evaluation of the micropig kidney as a potential renal donor.

    Science.gov (United States)

    Yoon, Woong; Lee, Min Young; Ryu, Jung Min; Moon, Yong Ju; Lee, Sang Hun; Park, Jae Hong; Yun, Seung Pil; Jang, Min Woo; Park, Sung Su; Han, Ho Jae

    2010-03-01

    Multidetector row computed tomography (MDCT) provides anatomical information about the kidney and other internal organs. Presently, the suitability of 64-channel MDCT to assess the kidney of healthy micropigs was evaluated. Morphological evaluations of the kidney and the major renal vessels of six healthy micropigs were carried out using MDCT, recording kidney volume and the diameter and length of renal arteries and veins. The mean diameters and lengths of the renal artery were 0.44 +/- 0.05 and 4.51 +/- 0.55 cm on the right side and 0.46 +/- 0.06 and 3.36 +/- 0.27 cm on the left side, respectively. The mean diameters and lengths of the renal vein were 1.44 +/- 0.52 and 4.22 +/- 1.29 cm on the right side and 1.38 +/- 0.17 and 5.15 +/- 0.87 cm on the left side, respectively. The mean volume of the right kidney was 79.3 +/- 14.5 mL and of the left kidney was 78.0 +/- 13.9 mL. The data presented in this study suggest that the MDCT offers a noninvasive, rapid, and accurate method for the evaluation of the renal anatomy in living kidney donors. It also provides sufficient information about extra-renal anatomy important for donor surgery and determination of organ suitability.

  20. Wedge-shaped parenchymal enhancement peripheral to the hepatic hemangioma : two-phase spiral CT findings

    International Nuclear Information System (INIS)

    Kim, Kyoung Won; Kim, Tae Kyoung; Han, Joon Koo; Kim, Ah Young; Lee, Hyun Ju; Song, Chi Sung; Choi, Byung Ihn

    2000-01-01

    To determine the incidence of hepatic hemangiomas associated with wedge-shaped parenchymal enhancements adjacent to the tumors as seen on two-phase spiral CT images obtained during the hepatic arterial phase and to characterize the two-phase spiral CT findings of those hemangiomas. One hundred and eight consecutive hepatic hemangiomas in 63 patients who underwent two-phase spiral CT scanning during an 11-month period were included in this study. Two-phase spiral CT scans were obtained during the hepatic arterial phase (30-second delay) and portal venous phase (65-second delay) after injection of 120 mL of contrast material at a rate of 3 mL/sec. We evaluated the frequency with which wedge-shaped parenchymal enhancement was adjacent to the hemangiomas during the hepatic arterial phase and divided hemangiomas into two groups according to whether or not wedge-shaped parenchymal enhancement was noted (Group A and Group B). The presence of such enhancement in hemangiomas was correlated with tumor size and the grade of intratumoral enhancement. In 24 of 108 hemangiomas, wedge-shaped parenchymal enhancement adjacent to hepatic tumors was seen on two-phase CT images obtained during the hepatic arterial phase. Mean hemangioma size was 22mm in group A and 24mm in group B. There was no statistically significant relationship between lesion size and the presence of wedge-shaped parenchymal enhancement adjacent to a hemangioma. In 91.7% and 100% of tumors in Group A, and in 9.6% and 17.8% in Group B, hemangiomas showed more than 50% intratumoral enhancement during the arterial and portal venous phase, respectively. Wedge-shaped parenchymal enhancements peripheral to hepatic hemangiomas was more frequently found in tumors showing more than 50% intratumoral enhancement during these two phases (p less than 0.01). Wedge-shaped parenchymal enhancements is not uncommonly seen adjacent to hepatic hemangiomas on two-phase spiral CT images obtained during the hepatic arterial phase. A

  1. A multidetector tomography protocol for follow-up of endovascular aortic aneurysm repair

    Directory of Open Access Journals (Sweden)

    Roberto Moraes Bastos

    2011-01-01

    Full Text Available OBJECTIVE: The purpose of this study was to improve the use of 64-channel multidetector computed tomography using lower doses of ionizing radiation during follow-up procedures in a series of patients with endovascular aortic aneurysm repair. METHODS: Thirty patients receiving 5 to 29 months of follow-up after endovascular aortic aneurysm repair were analyzed using a 64-channel multidetector computed tomography device by an exam that included pre-and postcontrast with both arterial and venous phases. Leak presence and type were classified based on the exam phase. RESULTS: Endoleaks were identified in 8/30 of cases; the endoleaks in 3/8 of these cases were not visible in the arterial phases of the exams. CONCLUSION: The authors conclude that multidetector computed tomography with pre-contrast and venous phases should be a part of the ongoing follow-up of patients undergoing endovascular aortic aneurysm repair. The arterial phase can be excluded when the aneurism is stable or regresses. These findings permit a lower radiation dose without jeopardizing the correct diagnosis of an endoleak.

  2. Image quality of high-resolution CT with 16-channel multidetector-row CT. Comparison between helical scan and conventional step-shoot scan

    International Nuclear Information System (INIS)

    Sumikawa, Hiromitsu; Johkoh, Takeshi; Koyama, Mitsuhiro

    2005-01-01

    The aim of this study was to evaluate the image quality of high-resolution CT (HRCT) reconstructed from volumetric data with 16-channel multidetector-row CT (MDCT). Eleven autopsy lungs that were diagnosed histopathologically were scanned by 16-channel MDCT with the step-and-shoot scan mode and three helical scan modes. Each helical mode had each size of focal spot, pitch, and time of gantry rotation. HRCT images were reconstructed from the volumetric data with each helical mode and axial sequence data. Two observers evaluated the image quality and noted the most appropriate diagnosis for each imaging. Visualization of abnormal structures with one helical mode was equal to those with axial mode, whereas those with the other two helical modes were inferior to those with axial mode (Wilcoxon signed rank test; p<0.0001). There was no significant difference in diagnostic efficacy between modes. The image quality of HRCT with appropriate helical mode is equal to that with axial mode and diagnostic efficacy is equal among all modes. These results may indicate that sufficient HRCT images can be obtained by only one helical scan without the addition of conventional axial scans. (author)

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

    Science.gov (United States)

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

    2008-04-01

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

  4. Detection of intracranial aneurysms with 64 channel multidetector row computed tomography: Comparison with digital subtraction angiography

    International Nuclear Information System (INIS)

    Pozzi-Mucelli, Fabio; Bruni, Stefano; Doddi, Marco; Calgaro, Antonio; Braini, Massimiliano; Cova, Maria

    2007-01-01

    Purpose: To compare the contribution of 64 channel multidetector row computed tomography angiography (64MDCT-angiography) with digital subtraction angiography (DSA) in the detection of intracranial aneurysms. Methods and materials: Twenty-nine patients (10 males and 19 females, age: 40-84 years; average: 61.9 years) with clinical and imaging findings strongly suggesting the presence of subaracnoid hemorrhage underwent 64MDCT-angiography and DSA with a short interval between the two examinations (less than 12 h-5 days). CT parameters were: 64 mm x 0.5 mm collimation, pitch-0.828 and helical pitch-53. DSA were performed with standard technique (four vessel catheterization) and multiple projections. Axial CT scans as well as maximum intensity projection, volume rendering and multiplanar reformations and angiographic views were independently reviewed by four readers (two for 64MDCT-angiography and two for DSA). Consensus was reached for discordant cases. DSA was considered as the standard of reference. Results: In 29 patients, 28 aneurysms were found (14 patients had 1 aneurysm, 4 patients had 2 aneurysms and 2 patients had 3 aneurysms; in 9 patients no aneurysm were found). 64MDCT-angiography detected 26/28 aneurysms. No false-positive sites were recognized. The sensitivity, specificity, positive and negative predictive values and diagnostic accuracy were, respectively, 92.8, 100, 100, 99.4 and 99.5%. Conclusions: 64MDCT-angiography is helpful in detecting intracranial aneurysms with results similar to those of DSA but with less discomfort and risks for the patients and can be considered for the first line imaging technique. Conventional angiography is still needed in doubtful cases or negative MDCT-angiography associated with a strong clinical suspect

  5. Multidetector row CT of the brain and carotid artery: a correlative analysis

    International Nuclear Information System (INIS)

    Saba, L.; Montisci, R.; Sanfilippo, R.; Mallarini, G.

    2009-01-01

    Aim: To evaluate the association between types of carotid plaque, the presence of prior ischaemic events detectable with CT, and patient's symptoms. Materials and methods: Between January 2004 and May 2006, 112 patients were evaluated using multidetector row computed tomography angiography (MDCTA) of the carotid arteries and computed tomography (CT) of the brain. Carotid arteries were categorized by evaluating the degree of stenosis according to North American Symptomatic Carotid Endarterectomy Trial (NASCET) criteria, the type of plaque, and the presence of plaque ulceration. The brain was assessed via CT for the presence, type, and position of lesions. Chi-square tests, Student's t test, and simple logistic regression analysis were performed and the Cohen kappa test was applied for interobserver variability measurement. Results: The Chi-square test indicated a statistically significant association between the presence of fatty plaques (p = 0.005) and CT-detectable lesions in the brain (p = 0.004). Moreover, the number of patients with CT-detectable brain lesions was greater in patients with >70% stenosis than in those with 70% stenosis and symptoms (p = 0.041), and an inverse association between calcified plaque and symptoms (p = 0.009). Conclusion: MDCTA allows adequate evaluation of the type of plaque. The results of the present study indicate that there is an association between cerebral lesions, symptoms, and fatty plaque in the carotid artery. The degree of stenosis also correlated with cerebral lesions and symptoms. According to the obtained data, the type of carotid plaque should be included among primary parameters in the classification of patients' risk class.

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

    International Nuclear Information System (INIS)

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

    2012-01-01

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

  7. Cumulative phase delay imaging for contrast-enhanced ultrasound tomography

    International Nuclear Information System (INIS)

    Demi, Libertario; Van Sloun, Ruud J G; Wijkstra, Hessel; Mischi, Massimo

    2015-01-01

    Standard dynamic-contrast enhanced ultrasound (DCE-US) imaging detects and estimates ultrasound-contrast-agent (UCA) concentration based on the amplitude of the nonlinear (harmonic) components generated during ultrasound (US) propagation through UCAs. However, harmonic components generation is not specific to UCAs, as it also occurs for US propagating through tissue. Moreover, nonlinear artifacts affect standard DCE-US imaging, causing contrast to tissue ratio reduction, and resulting in possible misclassification of tissue and misinterpretation of UCA concentration. Furthermore, no contrast-specific modality exists for DCE-US tomography; in particular speed-of-sound changes due to UCAs are well within those caused by different tissue types. Recently, a new marker for UCAs has been introduced. A cumulative phase delay (CPD) between the second harmonic and fundamental component is in fact observable for US propagating through UCAs, and is absent in tissue. In this paper, tomographic US images based on CPD are for the first time presented and compared to speed-of-sound US tomography. Results show the applicability of this marker for contrast specific US imaging, with cumulative phase delay imaging (CPDI) showing superior capabilities in detecting and localizing UCA, as compared to speed-of-sound US tomography. Cavities (filled with UCA) which were down to 1 mm in diameter were clearly detectable. Moreover, CPDI is free of the above mentioned nonlinear artifacts. These results open important possibilities to DCE-US tomography, with potential applications to breast imaging for cancer localization. (fast track communication)

  8. Ionic and non-ionic contrast media used for contrast-enhanced computed tomography in experimental pancreatitis

    International Nuclear Information System (INIS)

    Kivisaari, L.; Nuutinen, P.; Lehtola, A.; Saari, A.; Pitkaeranta, P.; Standertskjoeld-Nordenstam, C.G.; Lempinen, M.; Schroeder, T.; Helsinki Univ. Central Hospital

    1988-01-01

    Contrast enhancement of the pancreas was studied in pigs using dynamic computed tomography in experimental oedematous and haemorrhagic/necrotizing pancreatitis during the first two minutes after injection of an intravenous bolus of non-ionic contrast medium (iohexol). The prospects of separating the two forms of the disease, known to be possible with ionic contrast media, were tested with a non-ionic contrast medium. In the oedematous form, contrast enhancement after 5 hours of the disease was significantly higher than in the haemorrhagic/necrotizing form. Contrast enhancement after 30 hours of disease tended to vary with the severity of the disease, showing that the course of oedematous pancreatitis is dynamic. Intermediate forms occur and follow-up studies are needed during the disease. A non-ionic contrast medium proved as good for separating the two forms of the disease in the early phase as were ionic contrast media. In severely ill patients, non-ionic contrast media should therefore be used. (orig.)

  9. Detection of hepatic VX2 tumors in rabbits: comparison of conventional US and phase- inversion harmonic US during the liver- specific late phase of contrast enhancement

    International Nuclear Information System (INIS)

    Lee, Jeong Min; Youk, Ji Hyun; Lee, Young Hwan; Kim, Young Kon; Kim, Chong Soo; Li, Chun Ai

    2003-01-01

    To compare phase-inversion sonography during the liver-specific phase of contrast enhancement using a microbubble contrast agent with conventional B-mode sonography for the detection of VX2 liver tumors. Twenty-three rabbits, 18 of which had VX2 liver tumor implants, received a bolus injection of 0.6 g of Levovist (200 mg/ml). During the liver-specific phase of this agent, they were evaluated using both conventional sonography and contrast-enhanced phase-inversion harmonic imaging (CEPIHI). Following sacrifice of the animals, pathologic analysis was performed and the reference standard thus obtained. The conspicuity, size and number of the tumors before and after contrast administration, as determined by a sonographer, were compared between the two modes and with the pathologic findings. CE-PIHI demonstrated marked hepatic parenchymal enhancement in all rabbits. For VX2 tumors detected at both conventional US and CE- PIHI, conspicuity was improved by contrast-enhanced PIHI. On examination of gross specimens, 52 VX2 tumors were identified. Conventional US correctly detected 18 of the 52 (34.6%), while PIHI detected 35 (67.3%) (p < 0.05). In particular, conventional US detected only three (8.3%) of the 36 tumors less than 10 mm in diameter, but CE-PIHI detected 19 such tumors (52.8%) (p < 0.05). Compared to conventional sonography, PIHI performed during the liver-specific phase after intravenous injection of Levovist is markedly better at detecting VX2 liver tumors

  10. Accuracy of multidetector-row CT in diagnosing lymph node metastasis in patients with gastric cancer

    Energy Technology Data Exchange (ETDEWEB)

    Saito, Takuro; Kurokawa, Yukinori; Takiguchi, Shuji; Miyazaki, Yasuhiro; Takahashi, Tsuyoshi; Yamasaki, Makoto; Miyata, Hiroshi; Nakajima, Kiyokazu; Mori, Masaki; Doki, Yuichiro [Osaka University, Graduate School of Medicine, Department of Gastroenterological Surgery, Suita, Osaka (Japan)

    2014-08-06

    The purpose of this study was to determine the optimal cut-off value of lymph node size for diagnosing metastasis in gastric cancer with multidetector-row computed tomography (MDCT) after categorizing perigastric lymph nodes into three regions. The study included 90 gastric cancer patients who underwent gastrectomy. The long-axis diameter (LAD) and short-axis diameter (SAD) of all visualized lymph nodes were measured with transverse MDCT images. The locations of lymph nodes were categorized into three regions: lesser curvature, greater curvature, and suprapancreatic. The diagnostic value of lymph node metastasis was assessed with receiver operating characteristic (ROC) analysis. The area under the curve was larger for SAD than LAD in all groups. The optimal cut-off values of SAD were determined as follows: overall, 9 mm; differentiated type, 9 mm; undifferentiated type, 8 mm; lesser curvature region, 7 mm; greater curvature region, 6 mm; and suprapancreatic region, 9 mm. The diagnostic accuracies for lymph node metastasis using individual cut-off values were 71.1 % based on histological type and 76.6 % based on region of lymph node location. The diagnostic accuracy of lymph node metastasis in gastric cancer was improved by using individual cut-off values for each lymph node region. (orig.)

  11. Centrifugal (inside-out) enhancement of liver hemangiomas: A possible atypical appearance on contrast-enhanced US

    International Nuclear Information System (INIS)

    Bartolotta, Tommaso Vincenzo; Taibbi, Adele; Galia, Massimo; Lo Re, Giuseppe; La Grutta, Ludovico; Grassi, Roberto; Midiri, Massimo

    2007-01-01

    Objective: To report the prevalence and to describe the atypical centrifugal (inside-out) appearance of contrast-enhancement of liver hemangiomas on contrast-enhanced sonography. Materials and methods: Baseline and SonoVue-enhanced ultrasonography of 92 patients with 158 liver hemangiomas - considered atypical at grey-scale examination and confirmed by computed tomography, magnetic resonance imaging and ultrasound follow-up - were reviewed in consensus by two experienced radiologists, who evaluated baseline echogenicity and the dynamic enhancement pattern of each lesion looking for the presence of central enhancing foci in the arterial phase followed by a centrifugal (inside-out) enhancement in the portal-venous and late phases. Results: After administration of SonoVue, 12/158 hemangiomas (7.6%) (size range: 1-7 cm; mean: 3.2 cm) in seven patients (5 women, 2 men; age range: 34-71 years, mean: 50.8 years) showed a central enhancing focus in the arterial phase followed by a centrifugal enhancement in the portal-venous and late phases. In all cases centrifugal enhancement was incomplete at contrast-enhanced sonography, whereas computed tomography and/or magnetic resonance imaging were able to depict a complete and homogeneous fill-in. Conclusion: Radiologist should be aware that centrifugal (inside-out) appearance on contrast-enhanced sonography is a rare but possible feature of liver hemangioma

  12. Centrifugal (inside-out) enhancement of liver hemangiomas: A possible atypical appearance on contrast-enhanced US

    Energy Technology Data Exchange (ETDEWEB)

    Bartolotta, Tommaso Vincenzo [Department of Radiology, University of Palermo, Via Del Vespro 127, 90127 Palermo (Italy)], E-mail: tv.bartolotta@unipa.it; Taibbi, Adele [Department of Radiology, University of Palermo, Via Del Vespro 127, 90127 Palermo (Italy)], E-mail: taibbi_adele@yahoo.it; Galia, Massimo [Department of Radiology, University of Palermo, Via Del Vespro 127, 90127 Palermo (Italy)], E-mail: mgalia@yahoo.com; Lo Re, Giuseppe [Department of Radiology, University of Palermo, Via Del Vespro 127, 90127 Palermo (Italy)], E-mail: giuseppe.lore12@tin.it; La Grutta, Ludovico [Department of Radiology, University of Palermo, Via Del Vespro 127, 90127 Palermo (Italy)], E-mail: lagrutta@mbox.infcom.it; Grassi, Roberto [Institute of Radiology, Second University of Naples, Piazza Miraglia, 80138 Naples (Italy)], E-mail: roberto.grassi@libero.it; Midiri, Massimo [Department of Radiology, University of Palermo, Via Del Vespro 127, 90127 Palermo (Italy)], E-mail: mmidiri@hotmail.com

    2007-12-15

    Objective: To report the prevalence and to describe the atypical centrifugal (inside-out) appearance of contrast-enhancement of liver hemangiomas on contrast-enhanced sonography. Materials and methods: Baseline and SonoVue-enhanced ultrasonography of 92 patients with 158 liver hemangiomas - considered atypical at grey-scale examination and confirmed by computed tomography, magnetic resonance imaging and ultrasound follow-up - were reviewed in consensus by two experienced radiologists, who evaluated baseline echogenicity and the dynamic enhancement pattern of each lesion looking for the presence of central enhancing foci in the arterial phase followed by a centrifugal (inside-out) enhancement in the portal-venous and late phases. Results: After administration of SonoVue, 12/158 hemangiomas (7.6%) (size range: 1-7 cm; mean: 3.2 cm) in seven patients (5 women, 2 men; age range: 34-71 years, mean: 50.8 years) showed a central enhancing focus in the arterial phase followed by a centrifugal enhancement in the portal-venous and late phases. In all cases centrifugal enhancement was incomplete at contrast-enhanced sonography, whereas computed tomography and/or magnetic resonance imaging were able to depict a complete and homogeneous fill-in. Conclusion: Radiologist should be aware that centrifugal (inside-out) appearance on contrast-enhanced sonography is a rare but possible feature of liver hemangioma.

  13. Using 80 kVp on a 320-row scanner for hepatic multiphasic CT reduces the contrast dose by 50 % in patients at risk for contrast-induced nephropathy

    Energy Technology Data Exchange (ETDEWEB)

    Taguchi, Narumi; Oda, Seitaro; Utsunomiya, Daisuke; Nakaura, Takeshi; Imuta, Masanori; Yamamura, Sadahiro; Yuki, Hideaki; Kidoh, Masafumi; Hirata, Kenichiro; Namimoto, Tomohiro; Yamashita, Yasuyuki [Kumamoto University, Department of Diagnostic Radiology, Faculty of Life Sciences, Kumamoto (Japan); Funama, Yoshinori [Kumamoto University, Department of Medical Physics, Faculty of Life Sciences, Kumamoto (Japan); Hatemura, Masahiro; Kai, Noriyuki [Kumamoto University Hospital, Department of Central Radiology, Kumamoto (Japan)

    2017-02-15

    We evaluated the effects of a low contrast material (CM) dose protocol using 80-kVp on the image quality of hepatic multiphasic CT scans acquired on a 320-row CT scanner. We scanned 30 patients with renal insufficiency (eGFR < 45 mL/min/1.73 m{sup 2}) using 80-kVp and a CM dose of 300mgI/kg. Another 30 patients without renal insufficiency (eGFR > 60 mL/min/1.73 m{sup 2}) were scanned with the conventional 120-kVp protocol and the standard CM dose of 600mgI/kg. Quantitative image quality parameters, i.e. CT attenuation, image noise, and the contrast-to-noise ratio (CNR) were compared and the visual image quality was scored on a four-point scale. The volume CT dose index (CTDI{sub vol}) and the size-specific dose estimate (SSDE) recorded with the 80- and the 120-kVp protocols were also compared. Image noise and contrast enhancement were equivalent for the two protocols. There was no significant difference in the CNR of all anatomic sites and in the visual scores for overall image quality. The CTDI{sub vol} and SSDE were approximately 25-30 % lower under the 80-kVp protocol. Hepatic multiphase CT using 80-kVp on a 320-row CT scanner allowed for a decrease in the CM dose and a reduction in the radiation dose without image quality degradation in patients with renal insufficiency. (orig.)

  14. Correct diagnosis of vascular encasement and longitudinal extension of hilar cholangiocarcinoma by four-channel multidetector-row computed tomography

    International Nuclear Information System (INIS)

    Okumoto, Tadayuki; Yamada, Takayuki; Sato, Akihiro

    2009-01-01

    Accurate diagnosis of local invasion of hilar cholangiocarcinomas is challenging due to their small size and the anatomic complexity of the hepatic hilar region. On the other hand, the correct diagnosis of local invasion is essential for assuring the possibility of curative surgery. The purpose of this study was to evaluate the feasibility of four-channel multidetector-row computed tomography (MDCT) in the assessment of vascular and bile duct involvement, by which we could obtain useful information for the surgical management of hilar cholangiocarcinoma. The subjects were 18 patients for whom the extent of tumor invasion was surgically and pathologically confirmed. All patients underwent preoperative multiphasic CT scanning by MDCT. Arterial and portal dominant phases were acquired using a detector configuration of 1.25 mm x 4 mm, and both axial and multiplanar reconstructed images were interpreted. Longitudinal extension was evaluated up to second-order branches. Vascular invasion is considered to be the degree of tumor contiguity to the hepatic arteries and portal vein and was graded by CT. The longitudinal extension was correctly diagnosed in 14 patients (77.8%). Hepatic artery invasion was correctly diagnosed in 17 patients with sensitivity of 100% and specificity of 90%, respectively. Portal vein invasion was correctly diagnosed in 47 of 51 branches with sensitivity and specificity of 92.3% and 90.2%, respectively. Multiplanar reconstructed images contributed to the correct diagnosis for both vascular encasement and longitudinal tumor extension. In conclusion, MDCT is useful in preoperative evaluation of hilar cholangiocarcinoma, especially when combined with multiplanar reconstructed images. (author)

  15. Multidetector computed tomography predictors of late ventricular remodeling and function after acute myocardial infarction

    International Nuclear Information System (INIS)

    Lessick, Jonathan; Abadi, Sobhi; Agmon, Yoram; Keidar, Zohar; Carasso, Shemi; Aronson, Doron; Ghersin, Eduard; Rispler, Shmuel; Sebbag, Anat; Israel, Ora; Hammerman, Haim; Roguin, Ariel

    2012-01-01

    Background: Despite advent of rapid arterial revascularization as 1st line treatment for acute myocardial infarction (AMI), incomplete restoral of flow at the microvascular level remains a problem and is associated with adverse prognosis, including pathological ventricular remodeling. We aimed to study the association between multidetector row computed tomography (MDCT) perfusion defects and ventricular remodeling post-AMI. Methods: In a prospective study, 20 patients with ST-elevation AMI, treated by primary angioplasty, underwent arterial and late phase MDCT as well as radionuclide scans to study presence, size and severity of myocardial perfusion defects. Contrast echocardiography was performed at baseline and at 4 months follow-up to evaluate changes in myocardial function and remodeling. Results: Early defects (ED), late defects (LD) and late enhancement (LE) were detected in 15, 7 and 16 patients, respectively and radionuclide defects in 15 patients. The ED area (r = 0.74), and LD area (r = 0.72), and to a lesser extent LE area (r = 0.62) correlated moderately well with SPECT summed rest score. By univariate analysis, follow-up end-systolic volume index and ejection fraction were both significantly related to ED and LD size and severity, but not to LE size or severity. By multivariate analysis, end-systolic volume index was best predicted by LD area (p < 0.05) and ejection fraction by LD enhancement ratio. Conclusions: LD size and severity on MDCT are most closely associated with pathological ventricular remodeling after AMI and may thus play a role in early identification and treatment of this condition

  16. Dual focal-spot imaging for phase extraction in phase-contrast radiography

    International Nuclear Information System (INIS)

    Donnelly, Edwin F.; Price, Ronald R.; Pickens, David R.

    2003-01-01

    The purpose of this study was to evaluate dual focal spot imaging as a method for extracting the phase component from a phase-contrast radiography image. All measurements were performed using a microfocus tungsten-target x-ray tube with an adjustable focal-spot size (0.01 mm to 0.045 mm). For each object, high-resolution digital radiographs were obtained with two different focal spot sizes to produce matched image pairs in which all other geometric variables as well as total exposure and tube kVp were held constant. For each image pair, a phase extraction was performed using pixel-wise division. The phase-extracted image resulted in an image similar to the standard image processing tool commonly referred to as 'unsharp masking' but with the additional edge-enhancement produced by phase-contrast effects. The phase-extracted image illustrates the differences between the two images whose imaging parameters differ only in focal spot size. The resulting image shows effects from both phase contrast as well as geometric unsharpness. In weakly attenuating materials the phase-contrast effect predominates, while in strongly attenuating materials the phase effects are so small that they are not detectable. The phase-extracted image in the strongly attenuating object reflects differences in geometric unsharpness. The degree of phase extraction depends strongly on the size of the smallest focal spot used. This technique of dual-focal spot phase-contrast radiography provides a simple technique for phase-component (edge) extraction in phase-contrast radiography. In strongly attenuating materials the phase-component is overwhelmed by differences in geometric unsharpness. In these cases the technique provides a form of unsharp masking which also accentuates the edges. Thus, the two effects are complimentary and may be useful in the detection of small objects

  17. Contrast-enhanced computed tomographic colonography in the follow-up of colorectal cancer patients: a feasibility study

    International Nuclear Information System (INIS)

    Laghi, Andrea; Iannaccone, Riccardo; Carbone, Iacopo; Piacentini, Francesca; Passariello, Roberto; Bria, Emilio; Trasatti, Luciana; Lauro, Salvatore; Vecchione, Aldo

    2003-01-01

    The aim of our study was to assess whether contrast-enhanced CT colonography is a feasible alternative to both conventional colonoscopy and liver ultrasonography in the follow-up program of colorectal cancer patients. Thirty-five patients, surgically treated for colorectal cancer, underwent a follow-up program that included physical examination, carcinoembryonic antigen serum assay, conventional colonoscopy, liver ultrasonography, and chest X-ray. For these patients, we added a yearly contrast-enhanced CT colonography. All CT examinations were performed with a high-resolution protocol using a multidetector spiral CT scanner (Siemens, Erlangen, Germany) prior to and after the administration of 130 ml of i.v. contrast material. Images were directly analyzed on a dedicated workstation by two radiologists to determine colonic evaluation, visualization of colonic anastomosis, presence of polyps, and extra-colonic findings. Colonic evaluation was judged as optimal in 91.7% of all colonic segments. All mechanical surgical anastomoses were visualized with CT colonography. There was no evidence of anastomotic recurrence. Seven polyps were detected in five different patients with CT colonography, with two false-positive and no false-negative examinations. Three liver metastases and two basal pulmonary nodules were also identified. Contrast-enhanced CT colonography is a feasible alternative to both conventional colonoscopy and liver ultrasonography in the follow-up of patients operated on for colorectal cancer. (orig.)

  18. Quantification of myocardial blood flow using dynamic 320-row multi-detector CT as compared with ¹⁵O-H₂O PET.

    Science.gov (United States)

    Kikuchi, Yasuka; Oyama-Manabe, Noriko; Naya, Masanao; Manabe, Osamu; Tomiyama, Yuuki; Sasaki, Tsukasa; Katoh, Chietsugu; Kudo, Kohsuke; Tamaki, Nagara; Shirato, Hiroki

    2014-07-01

    This study introduces a method to calculate myocardium blood flow (MBF) and coronary flow reserve (CFR) using the relatively low-dose dynamic 320-row multi-detector computed tomography (MDCT), validates the method against (15)O-H₂O positron-emission tomography (PET) and assesses the CFRs of coronary artery disease (CAD) patients. Thirty-two subjects underwent both dynamic CT perfusion (CTP) and PET perfusion imaging at rest and during pharmacological stress. In 12 normal subjects (pilot group), the calculation method for MBF and CFR was established. In the other 13 normal subjects (validation group), MBF and CFR obtained by dynamic CTP and PET were compared. Finally, the CFRs obtained by dynamic CTP and PET were compared between the validation group and CAD patients (n = 7). Correlation between MBF of MDCT and PET was strong (r = 0.95, P dynamic CTP and PET (r = 0.67, P = 0.0126). CFRCT in the CAD group (2.3 ± 0.8) was significantly lower than that in the validation group (5.2 ± 1.8) (P = 0.0011). We established a method for measuring MBF and CFR with the relatively low-dose dynamic MDCT. Lower CFR was well demonstrated in CAD patients by dynamic CTP. • MBF and CFR can be calculated using dynamic CTP with 320-row MDCT. • MBF and CFR showed good correlation between dynamic CTP and PET. • Lower CFR was well demonstrated in CAD patients by dynamic CTP.

  19. Using the phase-space imager to analyze partially coherent imaging systems: bright-field, phase contrast, differential interference contrast, differential phase contrast, and spiral phase contrast

    Science.gov (United States)

    Mehta, Shalin B.; Sheppard, Colin J. R.

    2010-05-01

    Various methods that use large illumination aperture (i.e. partially coherent illumination) have been developed for making transparent (i.e. phase) specimens visible. These methods were developed to provide qualitative contrast rather than quantitative measurement-coherent illumination has been relied upon for quantitative phase analysis. Partially coherent illumination has some important advantages over coherent illumination and can be used for measurement of the specimen's phase distribution. However, quantitative analysis and image computation in partially coherent systems have not been explored fully due to the lack of a general, physically insightful and computationally efficient model of image formation. We have developed a phase-space model that satisfies these requirements. In this paper, we employ this model (called the phase-space imager) to elucidate five different partially coherent systems mentioned in the title. We compute images of an optical fiber under these systems and verify some of them with experimental images. These results and simulated images of a general phase profile are used to compare the contrast and the resolution of the imaging systems. We show that, for quantitative phase imaging of a thin specimen with matched illumination, differential phase contrast offers linear transfer of specimen information to the image. We also show that the edge enhancement properties of spiral phase contrast are compromised significantly as the coherence of illumination is reduced. The results demonstrate that the phase-space imager model provides a useful framework for analysis, calibration, and design of partially coherent imaging methods.

  20. Fusion of the midplane with the left intersectional plane: a liver anatomical variation revisited with multidetector-row CT

    International Nuclear Information System (INIS)

    Lucidarme, Olivier; Taboury, Jacques; Savier, Eric; Hannoun, Laurent; Cadi, Mehdi; Grenier, Philippe A.

    2006-01-01

    This article updates the description of an anatomical variation of the liver, in which the gallbladder is adjacent to the ligamentum teres, that was described until now as ''right-sided ligamentum teres and right umbilical portion of the portal vein''. A study of eight patients showing this anatomical variation has led to a new archetypal anatomical description of the hepatic and portal veins, using multidetector-row computed tomography (MDCT) with three-dimensional (3D) volume-rendering (VR) reconstructions. While 2D axial imaging gave the same information, MDCT imaging with VR reconstructions provided a clear 3D visualization of this anatomical variation. Typical features can be described as follows: (1) juxtaposition of the ligamentum teres and the gallbladder; (2) typical portal vein branching with a right posterior branch, a left posterior branch and a main medial branch that terminates in the ligamentum teres; (3) two main hepatic veins and a hypotrophied medial hepatic vein. We think, based on the direct comparison of anatomical findings and knowledge of chronological embryological development, that this abnormality results from the defective development of the central part of the liver and not from the persistence of the right rather than the left umbilical vein. Because of the presence of only one medial plane, containing both the gallbladder and the ligamentum teres, we propose renaming it ''fusion of hepatic planes''. (orig.)

  1. Focal Stenosis in Right Upper Lobe Bronchus in a Recurrently Wheezing Child Sequentially Studied by Multidetector-row Spiral Computed Tomography and Scintigraphy

    Directory of Open Access Journals (Sweden)

    I-Chen Chen

    2009-12-01

    Full Text Available Lower respiratory tract infections associated with wheezing are not uncommon in infants and young children. Among the wheezing-associated disorders, allergic etiologies are more commonly encountered than anatomic anomalies. We present a 3-year-old girl with a sudden attack of asthmatic symptoms including dyspnea, cyanosis and diffuse wheezing. Based on a history of choking, and atelectasis in the right upper lobe detected by chest films, flexible tracheobronchoscopy was arranged and incidentally detected a stenotic orifice in the right upper lobe bronchus. Multidetector-row spiral computed tomography and pulmonary scintigraphy subsequently also disclosed the focal stenosis. She suffered from recurrent wheezing, pneumonia and lung atelectasis during 1 year of follow-up. We emphasize the diagnosis, clinical course and management of focal stenosis in the right upper lobe bronchus.

  2. Quantification of myocardial blood flow using dynamic 320-row multi-detector CT as compared with 15O-H2O PET

    International Nuclear Information System (INIS)

    Kikuchi, Yasuka; Oyama-Manabe, Noriko; Kudo, Kohsuke; Naya, Masanao; Manabe, Osamu; Tomiyama, Yuuki; Tamaki, Nagara; Sasaki, Tsukasa; Katoh, Chietsugu; Shirato, Hiroki

    2014-01-01

    This study introduces a method to calculate myocardium blood flow (MBF) and coronary flow reserve (CFR) using the relatively low-dose dynamic 320-row multi-detector computed tomography (MDCT), validates the method against 15 O-H 2 O positron-emission tomography (PET) and assesses the CFRs of coronary artery disease (CAD) patients. Thirty-two subjects underwent both dynamic CT perfusion (CTP) and PET perfusion imaging at rest and during pharmacological stress. In 12 normal subjects (pilot group), the calculation method for MBF and CFR was established. In the other 13 normal subjects (validation group), MBF and CFR obtained by dynamic CTP and PET were compared. Finally, the CFRs obtained by dynamic CTP and PET were compared between the validation group and CAD patients (n = 7). Correlation between MBF of MDCT and PET was strong (r = 0.95, P CT in the CAD group (2.3 ± 0.8) was significantly lower than that in the validation group (5.2 ± 1.8) (P = 0.0011). We established a method for measuring MBF and CFR with the relatively low-dose dynamic MDCT. Lower CFR was well demonstrated in CAD patients by dynamic CTP. (orig.)

  3. Detection of intracranial aneurysms using three-dimensional multidetector-row CT angiography: Is bone subtraction necessary?

    International Nuclear Information System (INIS)

    Hwang, Seung Bae; Kwak, Hyo Sung; Han, Young Min; Chung, Gyung Ho

    2011-01-01

    Purpose: The aim of this study was to evaluate the usefulness of three-dimensional CT angiography (3D CTA) with bone subtraction in a comparison with 3D CTA without bone subtraction for the detection of intracranial aneurysms. Materials and methods: Among 337 consecutive patients who had intracranial aneurysms detected on 3D CTA, 170 patients who underwent digital subtraction angiography (DSA) were included in the study. CTA was performed with a 16-slice multidetector-row CT (MDCT) scanner. We created the 3D reconstruction images with and without bone subtraction by using the volume rendering technique. Three neuroradiologists in a blinded fashion interpreted both 3D CTA images with and without bone subtraction. The diagnostic accuracy of both techniques was evaluated using the alternative free-response receiver operating characteristic (ROC) analysis. The sensitivity and positive predictive value were also evaluated. Results: A total of 200 aneurysms (size: 2-23 mm) were detected in 170 patients. The area under the receiver operating characteristic curve (Az) for 3D CTA with bone subtraction (mean, Az = 0.933) was significantly higher than that for 3D CTA without bone subtraction (mean, Az = 0.879) for all observers (P < 0.05). The sensitivity of 3D CTA with bone subtraction for three observers was 90.0, 92.0 and 92.5%, respectively, while the sensitivity of 3D CTA without bone subtraction was 83.5, 83.5 and 87.5%, respectively. No significant difference in positive predictive value was observed between the two modalities. Conclusions: 3D CTA with bone subtraction showed significantly higher diagnostic accuracy for the detection of intracranial aneurysms as compared to 3D CTA without bone subtraction.

  4. Semi-quantitative assessment of tricuspid regurgitation on contrast-enhanced multidetector CT

    International Nuclear Information System (INIS)

    Groves, A.M.; Win, T.; Charman, S.C.; Wisbey, C.; Pepke-Zaba, J.; Coulden, R.A.

    2004-01-01

    AIM: To assess whether the early regurgitation of intravenous contrast medium into the inferior vena cava (IVC) and/or hepatic veins on computed tomography (CT), indicates tricuspid regurgitation (TR), and if so, whether it be used to grade severity. MATERIALS AND METHODS: We identified 86 consecutive patients that had been investigated for possible pulmonary endarterectomy at Papworth Hospital. From these, 61 patients were selected in whom CT, transthoracic echocardiography, and right heart catheterization (RHC) had been performed within 6 weeks. Using an arbitrary visual scale, the degree of TR assessed by intravenous contrast-enhanced CT was compared with echocardiography. Results were analysed using a kappa weighted statistical test. In addition, CT and echocardiographic assessments of TR severity were correlated with pulmonary artery pressure measurements obtained by RHC (Spearman's rank correlation coefficient). RESULTS: CT assessment of TR had a sensitivity of 90.4% and a specificity of 100% in detecting echocardiographic TR. For TR graded as more than trivial by echocardiography, sensitivity of CT was 100%. With respect to RHC data, the correlation between severity assessment of TR between CT and echocardiography using the Kappa weighted coefficient was 0.56 (moderately good agreement). With respect to RHC data, the correlation between mean pulmonary pressure and TR grading on CT and echocardiography was r=0.685 (p<0.001) and r=0.727 (p<0.001), respectively. CONCLUSION: Early opacification of the IVC or hepatic veins on first-pass contrast-enhanced CT almost invariably indicates TR. There is moderately good agreement between CT and echocardiographic assessment of the severity of TR. Both CT and echocardiographic grading of TR correlate well with RHC measurements of pulmonary artery pressure

  5. Analysis of 64-row multidetector CT images for preoperative angiographic evaluation of potential living kidney donors; Analyse der mehrphasigen 64-Zeilen-Multidetektor-Computertomographie zur praeoperativen angiographischen Evaluation potenzieller Lebendnierenspender

    Energy Technology Data Exchange (ETDEWEB)

    Blondin, D.; Andersen, K.; Kroepil, P.; Cohnen, M.; Moedder, U.; Jung, G. [Universitaetsklinikum Duesseldorf, Institut fuer Diagnostische Radiologie, Duesseldorf (Germany); Sandmann, W. [Universitaetsklinikum Duesseldorf, Klinik fuer Gefaesschirurgie und Nierentransplantation, Duesseldorf (Germany); Ivens, K. [Universitaetsklinikum Duesseldorf, Klinik fuer Nephrologie, Duesseldorf (Germany)

    2008-07-15

    Anatomical imaging and the ascertainment of any anomalies in the renal vessels and the ureters are essential in the planning of a kidney donation. The aim of the present study was to assess the value of 64-row multidetector CT in noninvasive examination of the renal vessels and ureters of potential living kidney donors. The evaluation embraced 63 living renal donors (LNS) who underwent preoperative CT examination from December 2004 to January 2007. The examinations were all carried out using a Somatom Sensation -Cardiac 64 (Siemens Medical Solutions, Germany). As well as CT angiography (CTA), a venous phase of the abdomen and a late phase after 15 min using low-dose technique were performed for CT urography (CTU). The radiological findings were compared with the surgical results, or with the angiograms in 2 cases. Sensitivity, specificity and both negative and positive predictive value were calculated. In the 63 (31 female, 32 male) donors CTA had a sensitivity of 100% in examination of the main and accessory renal arteries and of 98.3% when the venous and ureteric anatomy were assessed. The sensitivity of low-dose CTU was also 100%. The findings recorded in this study indicate that noninvasive preoperative planning with 64-row multidetector CTA and CTU is a reliable 'one-stop shopping' method of examination for potential living kidney donors. (orig.) [German] Die anatomische Darstellung und Erfassung moeglicher Anomalien der Nierengefaesse und Ureteren ist fuer die Planung einer Lebendnierenspende von essenzieller Bedeutung. Die vorliegende Untersuchung soll die Wertigkeit der nichtinvasiven Evaluation mit der 64-Zeilen-Multidetektor-CT untersuchen. In die Auswertung wurden 63 Lebendnierenspender (LNS) eingeschlossen, die im Zeitraum 12.2004 bis 01.2007 mit der CT praeoperativ untersucht wurden. Die Untersuchungen erfolgten mit einem Somatom-Sensation-Cardiac-64 (Siemens Medical Solutions, Deutschland). Neben einer CT-Angiographie (CTA) wurden eine

  6. Contrast-enhanced ultrasonography depicts small tumor vessels for the evaluation of pancreatic tumors

    International Nuclear Information System (INIS)

    Okamoto, Yuko; Kawamoto, Hirofumi; Takaki, Akinobu; Ishida, Etsuji; Ogawa, Tsuneyoshi; Kuwaki, Kenji; Kobayashi, Yoshiyuki; Sakaguchi, Kohsaku; Shiratori, Yasushi

    2007-01-01

    Objective: The aim of this study is to evaluate the efficacy of contrast-enhanced ultrasonography for the diagnosis of pancreatic tumors. Materials and methods: Contrast-enhanced ultrasonography with Levovist was performed on 62 consecutive patients (53 with pancreatic cancer, 4 with islet cell tumor, 3 with inflammatory pancreatic tumor, and 2 with metastatic tumor). The vascular and perfusion image phases of the tumors were evaluated and compared with the findings of contrast-enhanced computed tomography. Results: Contrast-enhanced ultrasonography showed tumor vessels around and/or in the tumor at the vascular image phase in 79% of pancreatic cancer patients (42/53). At the perfusion image phase, 96% of pancreatic cancers (51/53) were classified as hypo-enhancement type. However, tiny spotty or irregular heterogeneous enhanced lesions were found in 84% of hypo-enhanced pancreatic cancer patients (43/51). The presence of small vessels at the vascular image phase was closely correlated with the presence of these intratumor regional enhanced lesions at the perfusion image phase (κ coefficient = 0.42). The sensitivity of contrast-enhanced ultrasonography (100%) for pancreatic cancer was superior to that of contrast-enhanced computed tomography (91%), but no significant difference was observed between the two (McNemar test: p = 0.063). Conclusion: Contrast-enhanced ultrasonography with Levovist successfully visualizes fine vessels and enhancement in pancreatic tumors, and is useful for evaluating pancreatic tumors

  7. Evaluation of delayed contrast-enhanced CT scan in diagnosing hilar cholangiocarcinoma

    International Nuclear Information System (INIS)

    Li Jianding; Liang Chenyang; Zhang Hua; Zhang Yuezhen; Li Rui

    2001-01-01

    Objective: To assess the diagnostic value of delayed CT contrast enhancement patterns in hilar cholangiocarcinoma based on two-phased dynamic incremental CT scanning. Methods: Fifty-two patients with suspected hilar tumor and bile duct obstruction underwent spiral CT scan. The scan time for one revolution of the X-ray tube was 1 second. To elucidate the delay time for optimal imaging, all proved cholangiocarcinoma with delayed (6, 8, 10, 15, 20, 30 minutes) post-equilibrium-phase contrast-enhanced CT scans were acquired with unenhanced, dynamic contrast-enhanced, and delayed images. Degree of delayed enhancement was compared with that of surrounding liver parenchyma. Results: (1) 8-15 minutes after IV injection of contrast material was the delay time for optimal imaging. (2) Of 29 cholangiocarcinomas, the early CT showed hypo-attenuating (lower than that of liver parenchyma) in 23 tumors, iso-attenuating (equal to that of the liver) in 4 tumors, and hyper-attenuating (higher than that of liver) in 2 tumors. The delayed CT scan showed iso-attenuating in 8 tumors, hyper-attenuating in 21 tumors, and no hypo-attenuating. Most of delay imaging of hilar cholangiocarcinoma may appear hyper-attenuating (U = -4.3073, P 2 = 9.09, P < 0.01). Conclusion: When assessing hilar tumor, delayed CT contrast enhancement patterns based on two-phase dynamic incremental CT scans is useful in the detection and characterization of hilar cholangiocarcinoma

  8. Diagnostic accuracy of segmental enhancement inversion for diagnosis of renal oncocytoma at biphasic contrast enhanced CT: systematic review

    International Nuclear Information System (INIS)

    Schieda, Nicola; McInnes, Matthew D.F.; Cao, Lilly

    2014-01-01

    To use systematic review to evaluate the diagnostic accuracy of segmental enhancement inversion (SEI) at contrast-enhanced biphasic multi-detector computed tomography (MDCT) for the diagnosis of renal oncocytoma. Several electronic databases were searched through October 2013. Two reviewers independently selected studies that met the inclusion criteria and extracted data. Study quality was assessed with the QUADAS-2 tool. The primary 2 x 2 data were investigated with forest plot and ROC plot of sensitivity and specificity. Four studies met the inclusion criteria (307 patients). Considerable heterogeneity between studies precluded meta-analysis. Two studies from the same group of investigators demonstrated reasonable diagnostic accuracy (sensitivity 59-80 % and specificity 87-99 %), while two others did not (sensitivity 0-6 %, specificity 93-100 %). Possible reasons for this include timing of biphasic MDCT and methods of interpretation but not size of lesion. SEI is a specific imaging finding of renal oncocytoma with highly variable sensitivity. This substantial heterogeneity across studies and between institutions suggests that further validation of this imaging finding is necessary prior to application in clinical practice. (orig.)

  9. Diagnostic accuracy of segmental enhancement inversion for diagnosis of renal oncocytoma at biphasic contrast enhanced CT: systematic review

    Energy Technology Data Exchange (ETDEWEB)

    Schieda, Nicola; McInnes, Matthew D.F.; Cao, Lilly [Ottawa Hospital Research Institute, Department of Medical Imaging, Ottawa, ON (Canada)

    2014-06-15

    To use systematic review to evaluate the diagnostic accuracy of segmental enhancement inversion (SEI) at contrast-enhanced biphasic multi-detector computed tomography (MDCT) for the diagnosis of renal oncocytoma. Several electronic databases were searched through October 2013. Two reviewers independently selected studies that met the inclusion criteria and extracted data. Study quality was assessed with the QUADAS-2 tool. The primary 2 x 2 data were investigated with forest plot and ROC plot of sensitivity and specificity. Four studies met the inclusion criteria (307 patients). Considerable heterogeneity between studies precluded meta-analysis. Two studies from the same group of investigators demonstrated reasonable diagnostic accuracy (sensitivity 59-80 % and specificity 87-99 %), while two others did not (sensitivity 0-6 %, specificity 93-100 %). Possible reasons for this include timing of biphasic MDCT and methods of interpretation but not size of lesion. SEI is a specific imaging finding of renal oncocytoma with highly variable sensitivity. This substantial heterogeneity across studies and between institutions suggests that further validation of this imaging finding is necessary prior to application in clinical practice. (orig.)

  10. Multidetector computed tomography with triple-bolus contrast medium administration protocol for preoperative anatomical and functional assessment of potential living renal donors

    International Nuclear Information System (INIS)

    Knox, Matthew K.; Rivers-Bowerman, Michael D.; Bardgett, Harry P.; Cowan, Nigel C.

    2010-01-01

    To evaluate multidetector computed tomography (MDCT) with a triple-bolus contrast administration protocol for preoperative anatomical and functional assessment of living renal donors. Fifty-five potential living renal donors underwent MDCT of which 27 proceeded to donor nephrectomy. A triple-bolus contrast administration protocol was used for simultaneous acquisition of arterial, nephrographic, and excretory phases. MDCT images were independently reviewed in random order by two radiologists blinded to surgical anatomy findings. Diagnostic accuracy for anatomical variants was quantified by sensitivity and specificity. Differential renal function (DRF) was derived from MDCT for 54 patients and compared with technetium-99 m dimercaptosuccinic acid renography (Tc-99 m DMSA). All triple-bolus MDCT examinations were technically adequate. Accessory renal arteries and veins were identified at surgery in 33% (n = 9/27) and 22% (n = 6/27) of donor kidneys. The mean difference between MDCT-derived DRF and DMSA was 0.8% (95% CI 0.1-1.6) with 95% limits of agreement of -4.6% (95% CI -3.3 to -5.9) to 6.3% (95% CI 5.0-7.6). MDCT delivered a mean (SD, range) radiation dose of 9.5 (3.6, 3.6-17.3) mSv. MDCT with a triple-bolus contrast administration provides accurate anatomical and functional evaluation of living renal donors. (orig.)

  11. Multidetector computed tomography with triple-bolus contrast medium administration protocol for preoperative anatomical and functional assessment of potential living renal donors

    Energy Technology Data Exchange (ETDEWEB)

    Knox, Matthew K. [University of Calgary, Faculty of Medicine, UME Office, Health Sciences Centre, Calgary, Alberta (Canada); Rivers-Bowerman, Michael D. [University of British Columbia, Faculty of Medicine, MD Undergraduate Program, Diamond Health Care Centre, Vancouver, British Columbia (Canada); Bardgett, Harry P. [Bradford Teaching Hospitals, Department of Radiology, Bradford (United Kingdom); Cowan, Nigel C. [The Churchill Hospital, Department of Radiology, Oxford (United Kingdom)

    2010-11-15

    To evaluate multidetector computed tomography (MDCT) with a triple-bolus contrast administration protocol for preoperative anatomical and functional assessment of living renal donors. Fifty-five potential living renal donors underwent MDCT of which 27 proceeded to donor nephrectomy. A triple-bolus contrast administration protocol was used for simultaneous acquisition of arterial, nephrographic, and excretory phases. MDCT images were independently reviewed in random order by two radiologists blinded to surgical anatomy findings. Diagnostic accuracy for anatomical variants was quantified by sensitivity and specificity. Differential renal function (DRF) was derived from MDCT for 54 patients and compared with technetium-99 m dimercaptosuccinic acid renography (Tc-99 m DMSA). All triple-bolus MDCT examinations were technically adequate. Accessory renal arteries and veins were identified at surgery in 33% (n = 9/27) and 22% (n = 6/27) of donor kidneys. The mean difference between MDCT-derived DRF and DMSA was 0.8% (95% CI 0.1-1.6) with 95% limits of agreement of -4.6% (95% CI -3.3 to -5.9) to 6.3% (95% CI 5.0-7.6). MDCT delivered a mean (SD, range) radiation dose of 9.5 (3.6, 3.6-17.3) mSv. MDCT with a triple-bolus contrast administration provides accurate anatomical and functional evaluation of living renal donors. (orig.)

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

    International Nuclear Information System (INIS)

    Komatsu, Sei; Imai, Atsuko; Kodama, Kazuhisa

    2011-01-01

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

  13. Three-dimensional reconstructions of the orbital floor by volume-rendering of multidetector-row CT data

    International Nuclear Information System (INIS)

    Yoshikawa, Tetsuya; Miyajima, Akira; Fujita, Yuko; Yamada, Kazuo

    2011-01-01

    The advent of 3D-CT has made the evaluation of complicated facial fractures much easier than before. However, its use in injuries involving the orbital floor has been limited by the difficulty of visualizing the thin bony structures given artifacts caused by the partial volume effect. Nevertheless, high-technology machines such as multidetector-row CT (MDCT) and new-generation software have improved the quality of 3D imaging, and this paper describes a procedure for obtaining better visualization of the orbital floor using a MDCT scanner. Forty trauma cases were subject to MDCT: 13 with injury to the orbital floor, and 27 without. All scans were performed in the standard manner, at slice thicknesses of 0.5 mm. 3D-CT images were created overlooking the orbital floor including soft tissue to minimize the pseudo-foramen artifacts produced through volume rendering. Bone deficits, fracture lines, and grafted bone were visible in the 3D images, and visualization was supported by the ready creation of stereoscopic images from MDCT volume data. Measurement of the pseudo-foramen revealed approximately half the artifacts to be less than 5 mm in diameter, suggesting practicality of this method without subjecting the patient to undue increases in radiation exposure in the treatment of cases involving injury to the orbital floor. (author)

  14. 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)

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2011-11-15

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

  16. Imaging of acute mesenteric ischemia using multidetector CT and CT angiography in a porcine model.

    Science.gov (United States)

    Rosow, David E; Sahani, Dushyant; Strobel, Oliver; Kalva, Sanjeeva; Mino-Kenudson, Mari; Holalkere, Nagaraj S; Alsfasser, Guido; Saini, Sanjay; Lee, Susanna I; Mueller, Peter R; Fernández-del Castillo, Carlos; Warshaw, Andrew L; Thayer, Sarah P

    2005-12-01

    Acute mesenteric ischemia, a frequently lethal disease, requires prompt diagnosis and intervention for favorable clinical outcomes. This goal remains elusive due, in part, to lack of a noninvasive and accurate imaging study. Traditional angiography is the diagnostic gold standard but is invasive and costly. Computed tomography (CT) is readily available and noninvasive but has shown variable success in diagnosing this disease. The faster scanning time of multidetector row CT (M.D.CT) greatly facilitates the use of CT angiography (CTA) in the clinical setting. We sought to determine whether M.D.CT-CTA could accurately demonstrate vascular anatomy and capture the earliest stages of mesenteric ischemia in a porcine model. Pigs underwent embolization of branches of the superior mesenteric artery, then imaging by M.D.CT-CTA with three-dimensional reconstruction protocols. After scanning, diseased bowel segments were surgically resected and pathologically examined. Multidetector row CT and CT angiography reliably defined normal and occluded mesenteric vessels in the pig. It detected early changes of ischemia including poor arterial enhancement and venous dilatation, which were seen in all ischemic animals. The radiographic findings--compared with pathologic diagnoses-- predicted ischemia, with a positive predictive value of 92%. These results indicate that M.D.CT-CTA holds great promise for the early detection necessary for successful treatment of acute mesenteric ischemia.

  17. Mediastinal and hilar lymphadenopathy: cross-referenced anatomy on axial and coronal images displayed by using multi-detector row CT

    International Nuclear Information System (INIS)

    Lee, Ju Hyun; Lee, Kyung Soo; Kim, Tae Sung; Yi, Chin A; Cho, Jae Min; Lee, Min Hee

    2003-01-01

    The accurate evaluation of mediastinal and pulmonary hilar lymphadenopathy, especially in patients with lung cancer, is important for determining treatment options and evaluating the response to therapy. To indicate nodal location in detail, mediastinal and hilar lymph nodes have been assigned to one of 14 nodal stations. Mediastinal nodes of greater than 10 mm short-axis diameter are regarded as abnormal, irrespective of their nodal station, while hilar nodes are considered abnormal if their diameter is greater than 10 mm in any axis or they are convex compared to surrounding lung. By providing multiplanar images, multi-detector row CT allows detailed evaluation of thoracic anatomic structures more easily than in the past, when axial images only were available. At cross-referenced imaging, a lymph node depicted at axial imaging in one anatomical location can be visualized simultaneously and automatically at coronal imaging at the exactly corresponding anatomical location. Cross-referenced coincidental axial and coronal images help assess both the size and morphology of mediastinal and hilar lymph nodes

  18. Effects of computed tomography contrast medium factors on contrast enhancement

    International Nuclear Information System (INIS)

    Terasawa, Kazuaki; Hatcho, Atsushi; Okuda, Itsuko

    2011-01-01

    The various nonionic iodinated contrast media used in contrast computed tomography (CT) studies differ in terms of their composition, characteristics, and iodine concentration (mgI/ml), as well as the volume injected (ml). Compared with ionic iodinated contrast media, nonionic iodinated contrast media are low-osmolar agents, with different agents having different osmotic pressures. Using a custom-made phantom incorporating a semipermeable membrane, the osmotic flow rate (hounsfield unit (HU)/s) could easily be measured based on the observed increase in CT numbers, and the relationship between the osmotic pressure and the osmotic flow rate could be obtained (r 2 =0.84). In addition, taking the effects of patient size into consideration, the levels of contrast enhancement in the abdominal aorta (AA) and inferior vena cava (IVC) were compared among four types of CT contrast medium. The results showed differences in contrast enhancement in the IVC during the equilibrium phase depending on the type of contrast medium used. It was found that the factors responsible for the differences observed in enhancement in the IVC were the osmotic flow rate and the volume of the blood flow pathways in the circulatory system. It is therefore considered that the reproducibility of contrast enhancement is likely to be reduced in the examination of parenchymal organs, in which scanning must be performed during the equilibrium phase, even if the amount of iodine injected per unit body weight (mgI/kg) is maintained at a specified level. (author)

  19. Triple Arterial Phase MR Imaging with Gadoxetic Acid Using a Combination of Contrast Enhanced Time Robust Angiography, Keyhole, and Viewsharing Techniques and Two-Dimensional Parallel Imaging in Comparison with Conventional Single Arterial Phase

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, Jeong Hee [Department of Radiology, Seoul National University Hospital, Seoul 03080 (Korea, Republic of); Department of Radiology, Seoul National University College of Medicine, Seoul 03087 (Korea, Republic of); Lee, Jeong Min [Department of Radiology, Seoul National University Hospital, Seoul 03080 (Korea, Republic of); Department of Radiology, Seoul National University College of Medicine, Seoul 03087 (Korea, Republic of); Institute of Radiation Medicine, Seoul National University Medical Research Center, Seoul 03087 (Korea, Republic of); Yu, Mi Hye [Department of Radiology, Konkuk University Medical Center, Seoul 05030 (Korea, Republic of); Kim, Eun Ju [Philips Healthcare Korea, Seoul 04342 (Korea, Republic of); Han, Joon Koo [Department of Radiology, Seoul National University Hospital, Seoul 03080 (Korea, Republic of); Department of Radiology, Seoul National University College of Medicine, Seoul 03087 (Korea, Republic of); Institute of Radiation Medicine, Seoul National University Medical Research Center, Seoul 03087 (Korea, Republic of)

    2016-11-01

    To determine whether triple arterial phase acquisition via a combination of Contrast Enhanced Time Robust Angiography, keyhole, temporal viewsharing and parallel imaging can improve arterial phase acquisition with higher spatial resolution than single arterial phase gadoxetic-acid enhanced magnetic resonance imaging (MRI). Informed consent was waived for this retrospective study by our Institutional Review Board. In 752 consecutive patients who underwent gadoxetic acid-enhanced liver MRI, either single (n = 587) or triple (n = 165) arterial phases was obtained in a single breath-hold under MR fluoroscopy guidance. Arterial phase timing was assessed, and the degree of motion was rated on a four-point scale. The percentage of patients achieving the late arterial phase without significant motion was compared between the two methods using the χ{sup 2} test. The late arterial phase was captured at least once in 96.4% (159/165) of the triple arterial phase group and in 84.2% (494/587) of the single arterial phase group (p < 0.001). Significant motion artifacts (score ≤ 2) were observed in 13.3% (22/165), 1.2% (2/165), 4.8% (8/165) on 1st, 2nd, and 3rd scans of triple arterial phase acquisitions and 6.0% (35/587) of single phase acquisitions. Thus, the late arterial phase without significant motion artifacts was captured in 96.4% (159/165) of the triple arterial phase group and in 79.9% (469/587) of the single arterial phase group (p < 0.001). Triple arterial phase imaging may reliably provide adequate arterial phase imaging for gadoxetic acid-enhanced liver MRI.

  20. Triple arterial phase MR imaging with gadoxetic acid using a combination of contrast enhanced time robust angiography, keyhole, and viewsharing techniques and two-dimensional parallel imaging in comparison with conventional single arterial phase

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, Jeong Hee; Lee, Jeong Min; Han, Joon Koo [Dept. of Radiology, Seoul National University Hospital, Seoul (Korea, Republic of); Yu, Mi Hye [Dept. of Radiology, Konkuk University Medical Center, Seoul (Korea, Republic of); Kim, Eun Ju [Philips Healthcare Korea, Seoul (Korea, Republic of)

    2016-07-15

    To determine whether triple arterial phase acquisition via a combination of Contrast Enhanced Time Robust Angiography, keyhole, temporal viewsharing and parallel imaging can improve arterial phase acquisition with higher spatial resolution than single arterial phase gadoxetic-acid enhanced magnetic resonance imaging (MRI). Informed consent was waived for this retrospective study by our Institutional Review Board. In 752 consecutive patients who underwent gadoxetic acid-enhanced liver MRI, either single (n = 587) or triple (n = 165) arterial phases was obtained in a single breath-hold under MR fluoroscopy guidance. Arterial phase timing was assessed, and the degree of motion was rated on a four-point scale. The percentage of patients achieving the late arterial phase without significant motion was compared between the two methods using the χ2 test. The late arterial phase was captured at least once in 96.4% (159/165) of the triple arterial phase group and in 84.2% (494/587) of the single arterial phase group (p < 0.001). Significant motion artifacts (score ≤ 2) were observed in 13.3% (22/165), 1.2% (2/165), 4.8% (8/165) on 1st, 2nd, and 3rd scans of triple arterial phase acquisitions and 6.0% (35/587) of single phase acquisitions. Thus, the late arterial phase without significant motion artifacts was captured in 96.4% (159/165) of the triple arterial phase group and in 79.9% (469/587) of the single arterial phase group (p < 0.001). Triple arterial phase imaging may reliably provide adequate arterial phase imaging for gadoxetic acid-enhanced liver MRI.

  1. Compressive Phase Contrast Tomography

    International Nuclear Information System (INIS)

    Maia, Filipe; MacDowell, Alastair; Marchesini, Stefano; Padmore, Howard A.; Parkinson, Dula Y.; Pien, Jack; Schirotzek, Andre; Yang, Chao

    2010-01-01

    When x-rays penetrate soft matter, their phase changes more rapidly than their amplitude. Interference effects visible with high brightness sources creates higher contrast, edge enhanced images. When the object is piecewise smooth (made of big blocks of a few components), such higher contrast datasets have a sparse solution. We apply basis pursuit solvers to improve SNR, remove ring artifacts, reduce the number of views and radiation dose from phase contrast datasets collected at the Hard X-Ray Micro Tomography Beamline at the Advanced Light Source. We report a GPU code for the most computationally intensive task, the gridding and inverse gridding algorithm (non uniform sampled Fourier transform).

  2. ECG-triggered MDR-CT for the detection of pulmonary metastases

    International Nuclear Information System (INIS)

    Pauls, S.; Wahl, J.; Aschoff, A.J.; Brambs, H.J.; Fleiter, T.R.

    2003-01-01

    Purpose: Comparison of multidetector-row CT (MDR-CT) of the chest with and without ECG triggering for the detection of pulmonary metastases. Materials and Methods: Fifty patients with malignant tumors underwent CT of the chest. The unenhanced phase was performed with ECG-triggered MDR-CT and the contrast-enhanced phase with helical MDR-CT. The ECG-triggered and standard helical scans were interpreted in separate sessions, with the analysis determining the number and demarcation of the intrapulmonary nodules and the delineation of the mediastinal structure (rated 1 = excellent to 5 = poor). Results: ECG-MDR-CT images detected 38% more pulmonary nodules than MDR-CT. The detection rate for tumors [de

  3. Detection of the anatomic structure and pathology in animal lung specimens: comparison of micro CT and multi-detector row CT

    International Nuclear Information System (INIS)

    Lim, Kun Young; Lee, Hyun Ju; Lee, Chang Hyun; Son, Kyu Ri; Goo, Jin Mo; Im, Jung Gi; Seo, Joon Beom

    2006-01-01

    We wanted to compare the capability of micro CT and the clinically available thin-slice multi-detector row CT (MDCT) for demonstrating fine anatomic structures and pathological lesions in formalin-fixed lung specimens. The porcine lung with shark liver oil-induced lipoid pneumonia and the canine lung with pulmonary paragonimiasis were fixed by ventilating them with formalin vapor, and they were then sliced into one-centimeter thick sections. Micro CT (section thickness, 18 micrometer) and MDCT (section thickness, 0.75 mm) images were acquired in four of the lung slices of the lipoid pneumonia specimen and in five of the lung slices of the paragonimiasis specimen. On 62 pairs of micro CT and MDCT images, 169 pairs of rectangular ROIs were manually drawn in the corresponding locations. Two chest radiologists recorded the detectability of three kinds of anatomic structures (lobular core structure, interlobular septum and small bronchiolar lumen) and two kinds of pathological lesions (ground-glass opacity and consolidation) with using a five-point scale. The statistical comparison was performed by using the Wilcoxon signed rank test. Interobserver agreement was evaluated with kappa statistics. For all observers, all the kinds of anatomic structures and pathological lesions were detected better on the micro CT images than on the MDCT images (ρ < 0.01). Agreement was fair between two observers (κ = 0.38, ρ < 0.001). The fine anatomic structures and pathological lesions of the lung were more accurately demonstrated on micro CT than on thin-slice MDCT in the inflated and fixed lung specimens

  4. Detection of the anatomic structure and pathology in animal lung specimens: comparison of micro CT and multi-detector row CT

    Energy Technology Data Exchange (ETDEWEB)

    Lim, Kun Young [National Cancer Center, Goyang (Korea, Republic of); Lee, Hyun Ju; Lee, Chang Hyun; Son, Kyu Ri; Goo, Jin Mo; Im, Jung Gi [Seoul National University Hospital and the Institute of Radiation Medicine, Seoul (Korea, Republic of); Seo, Joon Beom [Asan Medical Center, University of Ulsan College of Medicine, Seoul (Korea, Republic of)

    2006-05-15

    We wanted to compare the capability of micro CT and the clinically available thin-slice multi-detector row CT (MDCT) for demonstrating fine anatomic structures and pathological lesions in formalin-fixed lung specimens. The porcine lung with shark liver oil-induced lipoid pneumonia and the canine lung with pulmonary paragonimiasis were fixed by ventilating them with formalin vapor, and they were then sliced into one-centimeter thick sections. Micro CT (section thickness, 18 micrometer) and MDCT (section thickness, 0.75 mm) images were acquired in four of the lung slices of the lipoid pneumonia specimen and in five of the lung slices of the paragonimiasis specimen. On 62 pairs of micro CT and MDCT images, 169 pairs of rectangular ROIs were manually drawn in the corresponding locations. Two chest radiologists recorded the detectability of three kinds of anatomic structures (lobular core structure, interlobular septum and small bronchiolar lumen) and two kinds of pathological lesions (ground-glass opacity and consolidation) with using a five-point scale. The statistical comparison was performed by using the Wilcoxon signed rank test. Interobserver agreement was evaluated with kappa statistics. For all observers, all the kinds of anatomic structures and pathological lesions were detected better on the micro CT images than on the MDCT images ({rho} < 0.01). Agreement was fair between two observers ({kappa} = 0.38, {rho} < 0.001). The fine anatomic structures and pathological lesions of the lung were more accurately demonstrated on micro CT than on thin-slice MDCT in the inflated and fixed lung specimens.

  5. Usefulness and safety of propranolol injection into vein for acquisition of coronary multidetector-row computed tomography

    International Nuclear Information System (INIS)

    Sekine, Takako; Kodama, Takahide; Kondo, Takeshi

    2010-01-01

    A low heart rate (HR), associated with a prolonged slow filling phase (SF), is necessary to obtain a high quality coronary CT at a low radiation dose with conventional 64 multidetector-row computed tomography (MDCT). The purpose of our study was to confirm the safety of injecting propranolol (2-10 mg) into the vein for lowering heart rate in patients requiring MDCT and to document the effect of the drug on HR, PQ and SF. Of 1290 consecutive patients who were initially considered for enrollment in the coronary MDCT study, 40 patients with atrial fibrillations, 3 with atrial flutters, and 13 with artificial pacemakers were excluded. Of the remaining 1234 patients (M/F=714/520), 331 had already taken an oral beta-blocker before the CT examination, and were included in the study. In patients with no contraindications, propranolol was aggressively injected (2-10 mg) into the vein to reduce the HR. In patients not taking an oral beta blocker, 2 mg propranolol reduced the HR by -10±5 bpm and 10 mg, by -20±7 bpm. However, in patients taking an oral beta-blocker, the decrease in HR by propranolol was minimal (2 mg, -6±4 bpm; 10 mg, -10±6 bpm). Propranolol significantly prolonged the PQ interval (from 169±27 to 179±29 ms, P<0.0001), and SF (from 125±69 to 264±79 ms, P<0.0001). Adverse effects of propranolol injection were observed in only 3 [2 mild hypotension and 1 paroxysmal atrial fibrillation (recovered to sinus rhythm by DC counter shock)] of 3212 patients. All 3 patients became stable after 1 or 2 hours of rest and could return home. Propranolol injection was a relatively safe and useful method to reduce HR and prolong SF, necessary for obtaining high quality coronary MDCT with a low radiation dose. (author)

  6. Assessment of temporal resolution of multi-detector row computed tomography in helical acquisition mode using the impulse method.

    Science.gov (United States)

    Ichikawa, Katsuhiro; Hara, Takanori; Urikura, Atsushi; Takata, Tadanori; Ohashi, Kazuya

    2015-06-01

    The purpose of this study was to propose a method for assessing the temporal resolution (TR) of multi-detector row computed tomography (CT) (MDCT) in the helical acquisition mode using temporal impulse signals generated by a metal ball passing through the acquisition plane. An 11-mm diameter metal ball was shot along the central axis at approximately 5 m/s during a helical acquisition, and the temporal sensitivity profile (TSP) was measured from the streak image intensities in the reconstructed helical CT images. To assess the validity, we compared the measured and theoretical TSPs for the 4-channel modes of two MDCT systems. A 64-channel MDCT system was used to compare TSPs and image quality of a motion phantom for the pitch factors P of 0.6, 0.8, 1.0 and 1.2 with a rotation time R of 0.5 s, and for two R/P combinations of 0.5/1.2 and 0.33/0.8. Moreover, the temporal transfer functions (TFs) were calculated from the obtained TSPs. The measured and theoretical TSPs showed perfect agreement. The TSP narrowed with an increase in the pitch factor. The image sharpness of the 0.33/0.8 combination was inferior to that of the 0.5/1.2 combination, despite their almost identical full width at tenth maximum values. The temporal TFs quantitatively confirmed these differences. The TSP results demonstrated that the TR in the helical acquisition mode significantly depended on the pitch factor as well as the rotation time, and the pitch factor and reconstruction algorithm affected the TSP shape. Copyright © 2015 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

  7. Assessment of hepatic arterial variation using multidetector helical CT-angiography

    International Nuclear Information System (INIS)

    Lee, Dong Hoon; Lee, Jun Woo; Jun, Woong Bae; Lee, Suk Hong

    2001-01-01

    To evaluate the anatomy of the hepatic artery and normal variants using oblique thick-slab maximal intensity projection (MIP) 3-D CT angiography and multidetector helical CT technology. In 70 patients, axial three-phase CT together with multidetector helical CT and a nonionic contrast agent was used to evaluate liver disease. During the early arterial phase, the parameters were as follow: slice thickness, 2.5 mm; table speed, 15 mm/rotation, pitch, 6; contrast material, 4 ml/sec; total 120 ml. Using the MIP technique and an Advantage window voxtal 3.03 system (GE), the images obtained were reconstructed as 3D angiograms. In each case, the arterial anatomy and its variants were recorded. A typical anatomy was found in 53 cases (75.7%). Common variants were a left hepatic artery arising from the left gastric artery(8 cases, 11.4 %) and a right hepatic artery arising from the superior mesenteric artery(3 cases, 4.3%). Other variant cases were right hepatic artery arising from the gastroduodenal artery(2 cases, 2.9%), a proper hepatic artery arising from the left gastric artery (1 case, 1.4%), a hepatomesenteric trunk (1 case), a hepatogastric/splenomesenteric trunk(1 case), and a celiomesenteric trunk (1 case). 3-D hepatic angiography using multidetector helical CT technology is non-invasive and as accurate as conventional angiography for the evaluation of hepatic arterial anatomy. It is thus considered that 3-D CT angiography is very helpful for the evaluation of hepatic arterial anatomy prior to liver surgery such as transplantation or the treatment of hepatocellular carinoma

  8. Diagnostic value of delayed washout rate of contrast-enhanced multi ...

    African Journals Online (AJOL)

    Rania Essameldein Mohamed

    2013-12-18

    Dec 18, 2013 ... On the other hand, CT contrast washout rate tests are more useful ..... with multidetector CT: pathologic conditions, pearls, and pitfalls. RadioGraphics 2009 ... advances in genetics, diagnosis, localization and treatment.

  9. Fast mutual-information-based contrast enhancement

    Science.gov (United States)

    Cao, Gang; Yu, Lifang; Tian, Huawei; Huang, Xianglin; Wang, Yongbin

    2017-07-01

    Recently, T. Celik proposed an effective image contrast enhancement (CE) method based on spatial mutual information and PageRank (SMIRANK). According to the state-of-the-art evaluation criteria, it achieves the best visual enhancement quality among existing global CE methods. However, SMIRANK runs much slower than the other counterparts, such as histogram equalization (HE) and adaptive gamma correction. Low computational complexity is also required for good CE algorithms. In this paper, we novelly propose a fast SMIRANK algorithm, called FastSMIRANK. It integrates both spatial and gray-level downsampling into the generation of pixel value mapping function. Moreover, the computation of rank vectors is speeded up by replacing PageRank with a simple yet efficient row-based operation of mutual information matrix. Extensive experimental results show that the proposed FastSMIRANK could accelerate the processing speed of SMIRANK by about 20 times, and is even faster than HE. Comparable enhancement quality is preserved simultaneously.

  10. Hepatocellular carcinoma on MR diffusion weighted imaging and dynamic contrast-enhanced imaging

    International Nuclear Information System (INIS)

    Dong Aisheng; Zuo Changjing; Tian Jianming; Lu Jianping; Wang Jian; Wang Li; Wang Fei

    2009-01-01

    Objective: To evaluate the findings of hepatocellular carcinoma (HCC) on DWI and dynamic Gd-DTPA-enhanced MR imaging. Methods: Eighty one patients with chronic hepatitis or liver cirrhosis underwent both DWI and dynamic Gd-DTPA-enhanced MRI studies of the liver for HCC detection. MR data of were retrospectively analyzed. Two observers determined in consensus the location and the number of focal lesions. The signal manifestation of the lesions on DWI and dynamic Gd-DTPA-enhanced MR imaging were analyzed. Results: DWI and Gd-DTPA-enhanced MR images detected 122 HCCs and 14 benign lesions. One hundred and sixteen HCCs (95.1%) showed hyperintensity on DWI and 6 HCCs in patients with severe cirrhosis showed isointensity. One hundred and five HCCs (86.1%) revealed hypointensity, 11 HCCs (9.0%) showed isointensity and 6 HCCs (4.9%) exhibited hyperintensity on T 1 weighted images. On Gd-DTPA-enhanced MR images, 101 HCCs(82.8%) were significantly enhanced on arterial phase and 99 HCCs showed hypointensity on portal and equilibrium phases. Twenty HCCs (16.4%), 18 of 20 less than 20 mm in diameter, showed isointensity on arterial phase and hyperintensity on DWI. Eight of 14 benign lesions showed hyperintensity and 6 isointensity on DWI. Five benign lesions with hypointensity on T 1 weighted images without contrast and hyperintensity on DWI showed no enhancement on Gd-DTPA-enhanced MR images; 6 benign lesions with isointensity on both T 1 weighted imaging without contrast and DWI exhibited avid enhancement on arterial phase and isointensty on portal and equilibrium phases; one of the two benign lesions, with isointensity before and after contrast images and hyperintentiy on DWI, was a regenerative nodule; another regenerative nodule with hyperintensity on both T 1 weighted images without contrast and DWI was greatly enhanced on arterial phase and showed isointensity on portal and equilibrium phases. Conclusions: Most of the HCCs were greatly enhanced on arterial phase on Gd-DTPA-enhanced

  11. Evaluation of prosthetic valve obstruction on electrocardiographically gated multidetector-row computed tomography--identification of subprosthetic pannus in the aortic position.

    Science.gov (United States)

    Ueda, Tomohiro; Teshima, Hideki; Fukunaga, Shuji; Aoyagi, Shigeaki; Tanaka, Hiroyuki

    2013-01-01

    This study was performed to evaluate the diagnostic role of electrocardiographically gated multidetector-row computed tomography (MDCT) for prosthetic valve obstruction (PVO) in the aortic position. Between 2002 and 2006, 9 patients were diagnosed with PVO of an aortic bileaflet mechanical valve based on echocardiographic and cineradiographic criteria. These 9 patients were examined using MDCT before replacement of the mechanical valve, and intraoperative findings were compared to morphologic periprosthetic abnormalities observed on MDCT. CT attenuation (Hounsfield units; HU) of the periprosthetic abnormalities was measured to investigate the underlying cause of the PVO. MDCT showed subprosthetic masses extending beyond the prosthetic ring into the orifice of the valve. At reoperation, presence of subprosthetic pannus was confirmed in all of the 9 patients, but no periprosthetic thrombus was found. The mean CT attenuation of the subprosthetic pannus was 170 HU, and it was significantly greater than that obtained from the interventricular septum (108 HU; Ppannus causing PVO and the mean CT attenuation of subprosthetic pannus is significantly higher than that of the interventricular septum on MDCT.

  12. Assessment of left ventricular myocardial function using 16-slice multidetector-row computed tomography: comparison with magnetic resonance imaging and echocardiography

    International Nuclear Information System (INIS)

    Heuschmid, Martin; Rothfuss, Julia K.; Fenchel, Michael; Stauder, Norbert; Kuettner, Axel; Miller, Stephan; Claussen, Claus D.; Kopp, Andreas F.; Schroeder, Stephen; Burgstahler, Christof; Franow, Andreas; Kuzo, Ronald S.

    2006-01-01

    To assess functional parameters using multidetector-row computed tomography (MDCT) and echocardiography and to compare the results with magnetic resonance imaging (MRI). End-diastolic-volume (EDV), end-systolic-volume (ESV), stroke-volume (SV), ejection-fraction (EF), and myocardial mass (MM) were calculated based on CT data sets from 52 patients. Echocardiography was performed in 24 of the 52 patients. The results from MDCT and echocardiography were compared with MRI. A strong correlation between MDCT and MRI (r=0.66-0.90) was found for all parameters. Echocardiography revealed a low or moderate correlation (0.05-0.59). Compared to MRI the average differences with MDCT were for EDV 15.1 ml, ESV 10.6 ml, SV 4.5 ml, EF 1.8%, and MM 8.2 g, for EDV determined by echocardiography 36.2 ml, ESV 6.8 ml, and EF 13.9%. Bland-Altman analysis revealed acceptable limits of agreement between MRI and MDCT. MDCT enables reliable quantification of left ventricular function. Echocardiography was found to have only a moderate agreement of functional parameters with MRI. (orig.)

  13. Comparison of a dental cone beam CT with a multi-detector row CT on effective doses and physical image quality

    International Nuclear Information System (INIS)

    Yoshida, Yutaka; Tokumori, Kenji; Okamura, Kazutoshi; Yoshiura, Kazunori

    2011-01-01

    The purpose of this study was to compare a dental cone beam computed tomography (dental CBCT) and a multi-detector row CT (MDCT) using effective doses and physical image quality. A dental mode (D-mode) and an implant mode (I-mode) were employed for calculating effective doses. Field of view (FOV) size of the MDCT was 150 mm. Three types of images were obtained using 3 different reconstruction functions: FC1 (for abdomen images), FC30 (for internal ear and bone images) and FC81 (for high resolution images). Effective doses obtained with the D-mode and with the I-mode were about 20% and 50% of those obtained with the MDCT, respectively. Resolution properties obtained with the D-mode and I-mode were superior to that of the MDCT in a high frequency range. Noise properties of the D-mode and the I-mode were better than those with FC81. It was found that the dental CBCT has better potential as compared with MDCT in both dental and implant modes. (author)

  14. Quantitative Analysis of First-Pass Contrast-Enhanced Myocardial Perfusion Multidetector CT Using a Patlak Plot Method and Extraction Fraction Correction During Adenosine Stress

    Science.gov (United States)

    Ichihara, Takashi; George, Richard T.; Silva, Caterina; Lima, Joao A. C.; Lardo, Albert C.

    2011-02-01

    The purpose of this study was to develop a quantitative method for myocardial blood flow (MBF) measurement that can be used to derive accurate myocardial perfusion measurements from dynamic multidetector computed tomography (MDCT) images by using a compartment model for calculating the first-order transfer constant (K1) with correction for the capillary transit extraction fraction (E). Six canine models of left anterior descending (LAD) artery stenosis were prepared and underwent first-pass contrast-enhanced MDCT perfusion imaging during adenosine infusion (0.14-0.21 mg/kg/min). K1 , which is the first-order transfer constant from left ventricular (LV) blood to myocardium, was measured using the Patlak plot method applied to time-attenuation curve data of the LV blood pool and myocardium. The results were compared against microsphere MBF measurements, and the extraction fraction of contrast agent was calculated. K1 is related to the regional MBF as K1=EF, E=(1-exp(-PS/F)), where PS is the permeability-surface area product and F is myocardial flow. Based on the above relationship, a look-up table from K1 to MBF can be generated and Patlak plot-derived K1 values can be converted to the calculated MBF. The calculated MBF and microsphere MBF showed a strong linear association. The extraction fraction in dogs as a function of flow (F) was E=(1-exp(-(0.2532F+0.7871)/F)) . Regional MBF can be measured accurately using the Patlak plot method based on a compartment model and look-up table with extraction fraction correction from K1 to MBF.

  15. Automated contrast medium monitoring system for computed tomography--Intra-institutional audit.

    Science.gov (United States)

    Lauretti, Dario Luca; Neri, Emanuele; Faggioni, Lorenzo; Paolicchi, Fabio; Caramella, Davide; Bartolozzi, Carlo

    2015-12-01

    The aim of this study was to analyze the usage and the data recorded by a RIS-PACS-connected contrast medium (CM) monitoring system (Certegra(®), Bayer Healthcare, Leverkusen, Germany) over 19 months of CT activity. The system used was connected to two dual syringe power injectors (each associated with a 16-row and a high definition 64-row multidetector CT scanner, respectively), allowing to manage contrast medium injection parameters and to send and retrieve CT study-related information via RIS/PACS for any scheduled contrast-enhanced CT examination. The system can handle up to 64 variables and can be accessed via touchscreen by CT operators as well as via a web interface by registered users with three different hierarchy levels. Data related to CM injection parameters (i.e. iodine concentration, volume and flow rate of CM, iodine delivery rate and iodine dose, CM injection pressure, and volume and flow rate of saline), patient weight and height, and type of CT study over a testing period spanning from 1 June 2013 to 10 January 2015 were retrieved from the system. Technical alerts occurred for each injection event (such as system disarm due to technical failure, disarm due to operator's stop, incomplete filling of patient data fields, or excessively high injection pressure), as well as interoperability issues related to data sending and receiving to/from the RIS/PACS were also recorded. During the testing period, the CM monitoring system generated a total of 8609 reports, of which 7629 relative to successful injection events (88.6%). 331 alerts were generated, of which 40 resulted in injection interruption and 291 in CM flow rate limitation due to excessively high injection pressure (>325 psi). Average CM volume and flow rate were 93.73 ± 17.58 mL and 3.53 ± 0.89 mL/s, and contrast injection pressure ranged between 5 and 167 psi. A statistically significant correlation was found between iodine concentration and peak IDR (rs=0.2744, psystems can provide a full

  16. Sensitivity and accuracy of volumetry of pulmonary nodules on low-dose 16- and 64-row multi-detector CT: an anthropomorphic phantom study

    International Nuclear Information System (INIS)

    Xie, Xueqian; Zhao, Yingru; Ooijen, Peter M.A. van; Vliegenthart, Rozemarijn; Snijder, Roland A.; Greuter, Marcel J.W.; Jong, Pim A. de; Oudkerk, Matthijs; Bock, Geertruida H. de

    2013-01-01

    To assess the sensitivity of detection and accuracy of volumetry by manual and semi-automated quantification of artificial pulmonary nodules in an anthropomorphic thoracic phantom on low-dose CT. Fifteen artificial spherical nodules (diameter 3, 5, 8, 10 and 12 mm; CT densities -800, -630 and +100 HU) were randomly placed inside an anthropomorphic thoracic phantom. The phantom was examined on 16- and 64-row multidetector CT with a low-dose protocol. Two independent blinded observers screened for pulmonary nodules. Nodule diameter was measured manually, and volume calculated. For solid nodules (+100 HU), diameter and volume were also evaluated by semi-automated software. Differences in observed volumes between the manual and semi-automated method were evaluated by a t-test. Sensitivity was 100 % for all nodules of >5 mm and larger, 60-80 % for solid and 0-20 % for non-solid 3-mm nodules. No false-positive nodules but high inter-observer reliability and inter-technique correlation were found. Volume was underestimated manually by 24.1 ± 14.0 % for nodules of any density, and 26.4 ± 15.5 % for solid nodules, compared with 7.6 ± 8.5 % (P 5 mm in diameter. Semi-automated volumetry yielded more accurate nodule volumes than manual measurements. (orig.)

  17. Detection of intracranial aneurysms using multi-detector row CT 3D-angiography: comparison with operative findings

    Energy Technology Data Exchange (ETDEWEB)

    Han, You Mie; Lim, Soo Mee; Seo, Eui Kyo; Kim, Yoo Kyung [Mokdong Hospital, Ewha Womans University, Seoul (Korea, Republic of)

    2006-04-15

    To assess the efficacy of three-dimensional CT angiography (3D-CTA) using multi-detector row computed tomography (MDCT) in the evaluation of intracranial aneurysms in patients with non-traumatic acute subarachnoid hemorrhage and to describe those aneurysms which were not found 3D-CTA. 3D-CTA was done in 40 patients with non-traumatic subarachnoid hemorrhage by using a 16-slice MDCT; conventional digital subtraction angiography (DSA) was done in 36 of those patients within 12 hours. The CT and DSA images were reviewed by two radiologists and the site, size and neck of the aneurysms were evaluated. The results from these two modalities were then compared with the operative findings. We calculated the detection rates by 3D-CTA and DSA and evaluated the size differences of aneurysms diagnosed with 3D-DTA and those found at surgery. We also analyzed the locations and sizes of aneurysms missed by 3D-CTA and attempted to explain these false negatives. A total of 55 aneurysms were surgically confirmed in 40 patients. 48 of these were detected pre-operatively by 3D-CTA. Thus, the detection rate by 3D-CTA was 87%. The size difference of aneurysms as calculated by 3-D CTA and found operatively was as follows: less than 1 mm in 17 cases, within 1-2 mm in 15 cases, and more than 2 mm in 16 cases. Seven aneurysms were not detected by 3D-CTA. The major cause of these missed aneurysms was their small size. The undetected aneurysms were less than 2 mm in size, except for 2 instances of PCoA aneurysms. One case was not detected due to difficult image evaluation. A possible explanation of the one remaining missed aneurysms was the filling of the aneurismal sac by thrombosis. Though there were some limitations in the detection of aneurysms, 3D-CTA using 16-channel MDCT may provide sufficient pre-operative information for the management of patients with intracranial aneurysms in cases of emergency operations or DSA-failure.

  18. Detection of intracranial aneurysms using multi-detector row CT 3D-angiography: comparison with operative findings

    International Nuclear Information System (INIS)

    Han, You Mie; Lim, Soo Mee; Seo, Eui Kyo; Kim, Yoo Kyung

    2006-01-01

    To assess the efficacy of three-dimensional CT angiography (3D-CTA) using multi-detector row computed tomography (MDCT) in the evaluation of intracranial aneurysms in patients with non-traumatic acute subarachnoid hemorrhage and to describe those aneurysms which were not found 3D-CTA. 3D-CTA was done in 40 patients with non-traumatic subarachnoid hemorrhage by using a 16-slice MDCT; conventional digital subtraction angiography (DSA) was done in 36 of those patients within 12 hours. The CT and DSA images were reviewed by two radiologists and the site, size and neck of the aneurysms were evaluated. The results from these two modalities were then compared with the operative findings. We calculated the detection rates by 3D-CTA and DSA and evaluated the size differences of aneurysms diagnosed with 3D-DTA and those found at surgery. We also analyzed the locations and sizes of aneurysms missed by 3D-CTA and attempted to explain these false negatives. A total of 55 aneurysms were surgically confirmed in 40 patients. 48 of these were detected pre-operatively by 3D-CTA. Thus, the detection rate by 3D-CTA was 87%. The size difference of aneurysms as calculated by 3-D CTA and found operatively was as follows: less than 1 mm in 17 cases, within 1-2 mm in 15 cases, and more than 2 mm in 16 cases. Seven aneurysms were not detected by 3D-CTA. The major cause of these missed aneurysms was their small size. The undetected aneurysms were less than 2 mm in size, except for 2 instances of PCoA aneurysms. One case was not detected due to difficult image evaluation. A possible explanation of the one remaining missed aneurysms was the filling of the aneurismal sac by thrombosis. Though there were some limitations in the detection of aneurysms, 3D-CTA using 16-channel MDCT may provide sufficient pre-operative information for the management of patients with intracranial aneurysms in cases of emergency operations or DSA-failure

  19. Current development of cardiac imaging with multidetector-row CT

    International Nuclear Information System (INIS)

    Becker, Christoph R.; Ohnesorge, Bernd M.; Schoepf, U. Joseph; Reiser, Maximilian F.

    2000-01-01

    Multidector-row CT (MDCT) with retrospective ECG gating allows scanning the entire heart with 1.25 mm slice thickness and 250 ms effective exposure time within 35 s investigation time. The resulting images allow for an accurate high-resolution assessment of morphological detail of both the coronary arteries and the cardiac chambers. Performing a contrast-enhanced MDCT angiography (MD-CTA) in addition to a non-enhanced scan for the detection and quantification of coronary calcifications may be indicated in patients with atypical chest pain and in young patients with high cardiovascular risk. This group of patients may show non-calcified plaques as the first sign of their coronary artery disease. As the proximal part of the coronary arteries is well displayed by MD-CTA it also helps to delineate the course in anomalous coronary vessels. Additional information is drawn from the preoperative use of MD-CTA do determine the distance of the left internal mammarian artery to the left anterior descending coronary artery prior to minimal invasive bypass grafting. Additional indications for MD-CTA are the non-invasive follow up after venous bypass grafting, PTCA, and coronary stent interventions. MD-CTA allows following the course of the coronary vessels to the level of third generation coronary segmental arteries. A definite diagnosis to rule out coronary artery disease can be reliably made in vessels with a diameter of 1.5 mm or greater. With MDCT a number of different atherosclerotic changes can be observed in diseased coronary arteries. Non-stenotic lesions may show tiny calcifications surrounded by large areas of irregularly distributed soft tissue. Calcifications in this type of atherosclerotic coronary artery wall changes appear as 'the tip of iceberg'. Heavy calcifications usually tend to be non-stenotic because of vessel remodelling resulting in a widening of the coronary vessel lumen. Therefore, heavy calcifications appear to act like an 'internal stent' for a

  20. A new method for information retrieval in two-dimensional grating-based X-ray phase contrast imaging

    International Nuclear Information System (INIS)

    Wang Zhi-Li; Gao Kun; Chen Jian; Ge Xin; Tian Yang-Chao; Wu Zi-Yu; Zhu Pei-Ping

    2012-01-01

    Grating-based X-ray phase contrast imaging has been demonstrated to be an extremely powerful phase-sensitive imaging technique. By using two-dimensional (2D) gratings, the observable contrast is extended to two refraction directions. Recently, we have developed a novel reverse-projection (RP) method, which is capable of retrieving the object information efficiently with one-dimensional (1D) grating-based phase contrast imaging. In this contribution, we present its extension to the 2D grating-based X-ray phase contrast imaging, named the two-dimensional reverse-projection (2D-RP) method, for information retrieval. The method takes into account the nonlinear contributions of two refraction directions and allows the retrieval of the absorption, the horizontal and the vertical refraction images. The obtained information can be used for the reconstruction of the three-dimensional phase gradient field, and for an improved phase map retrieval and reconstruction. Numerical experiments are carried out, and the results confirm the validity of the 2D-RP method

  1. Evaluation of thoracic abnormalities on 64-row multi-detector row CT: Comparison between axial images versus coronal reformations

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    Nishino, Mizuki [Department of Radiology, Beth Israel Deaconess Medical Center, 330 Brookline Ave., Boston, MA 02215 (United States)]. E-mail: mnishino@bidmc.harvard.edu; Kubo, Takeshi [Department of Radiology, Beth Israel Deaconess Medical Center, 330 Brookline Ave., Boston, MA 02215 (United States); Kataoka, Milliam L. [Department of Radiology, Beth Israel Deaconess Medical Center, 330 Brookline Ave., Boston, MA 02215 (United States); Gautam, Shiva [Department of General Clinical Research Center and Biometrics, Beth Israel Deaconess Medical Center, 330 Brookline Ave., Boston, MA 02215 (United States); Raptopoulos, Vassilios [Department of Radiology, Beth Israel Deaconess Medical Center, 330 Brookline Ave., Boston, MA 02215 (United States); Hatabu, Hiroto [Department of Radiology, Beth Israel Deaconess Medical Center, 330 Brookline Ave., Boston, MA 02215 (United States)

    2006-07-15

    Purpose: To evaluate the capability of coronal reformations of chest on 64-row MDCT in demonstrating thoracic abnormalities in comparison with axial images. Materials and methods: Thirty-eight consecutive patients who underwent pulmonary CTA on 64-row MDCT were retrospectively studied with institutional review board (IRB) approval. Contiguous 2 mm axial and coronal images were reviewed independently with a 1-week interval, by consensus reading of two board-certified radiologists. Overall image quality was graded using a five-point scale. Abnormalities in mediastinum, hilum, pulmonary vessels, aorta, heart, esophagus, pleura, chest wall, and lung parenchyma were scored: 1 = definitely absent, 2 = probably absent, 3 = equivocal, 4 probably present, 5 = definitely present. Scores on axial and coronal images were compared using weighted {kappa} analysis. Results: Overall image quality was not different with statistical relevance between axial and coronal images (mean/median scores; 3.7/4; 3.6/4, respectively, P = 0.286, Wilcoxon signed-rank test). Significant agreement was observed between axial and coronal scores (mean weighted {kappa}, 0.661; range, 0.362-1). Agreement was almost perfect for pneumothorax, lung and pleural mass, effusion and consolidation (weighted {kappa} = 0.833-1); substantial for pulmonary embolism, trachea, mediastinal lymphadenopathy and non-skeletal chest wall lesion, heart, esophagus, and emphysema (weighted {kappa}, 0.618-0.799); moderate for atelectasis, mediastinum, hilar nodes, aorta, other lung lesions, skeletal chest wall lesions, linear scarring, nodules >1 cm, pulmonary artery abnormalities and pleural thickening (weighted {kappa}, 0.405-0.592); and fair for nodules <1 cm (weighted {kappa} = 0.362). Conclusion: Coronal reformations on 64-row MDCT had substantial agreement with axial images for evaluation of the majority of thoracic abnormalities.

  2. Evaluation of thoracic abnormalities on 64-row multi-detector row CT: Comparison between axial images versus coronal reformations

    International Nuclear Information System (INIS)

    Nishino, Mizuki; Kubo, Takeshi; Kataoka, Milliam L.; Gautam, Shiva; Raptopoulos, Vassilios; Hatabu, Hiroto

    2006-01-01

    Purpose: To evaluate the capability of coronal reformations of chest on 64-row MDCT in demonstrating thoracic abnormalities in comparison with axial images. Materials and methods: Thirty-eight consecutive patients who underwent pulmonary CTA on 64-row MDCT were retrospectively studied with institutional review board (IRB) approval. Contiguous 2 mm axial and coronal images were reviewed independently with a 1-week interval, by consensus reading of two board-certified radiologists. Overall image quality was graded using a five-point scale. Abnormalities in mediastinum, hilum, pulmonary vessels, aorta, heart, esophagus, pleura, chest wall, and lung parenchyma were scored: 1 = definitely absent, 2 = probably absent, 3 = equivocal, 4 probably present, 5 = definitely present. Scores on axial and coronal images were compared using weighted κ analysis. Results: Overall image quality was not different with statistical relevance between axial and coronal images (mean/median scores; 3.7/4; 3.6/4, respectively, P = 0.286, Wilcoxon signed-rank test). Significant agreement was observed between axial and coronal scores (mean weighted κ, 0.661; range, 0.362-1). Agreement was almost perfect for pneumothorax, lung and pleural mass, effusion and consolidation (weighted κ = 0.833-1); substantial for pulmonary embolism, trachea, mediastinal lymphadenopathy and non-skeletal chest wall lesion, heart, esophagus, and emphysema (weighted κ, 0.618-0.799); moderate for atelectasis, mediastinum, hilar nodes, aorta, other lung lesions, skeletal chest wall lesions, linear scarring, nodules >1 cm, pulmonary artery abnormalities and pleural thickening (weighted κ, 0.405-0.592); and fair for nodules <1 cm (weighted κ = 0.362). Conclusion: Coronal reformations on 64-row MDCT had substantial agreement with axial images for evaluation of the majority of thoracic abnormalities

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

    International Nuclear Information System (INIS)

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

    2008-01-01

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

  4. Capability of abdominal 320-detector row CT for small vasculature assessment compared with that of 64-detector row CT

    Energy Technology Data Exchange (ETDEWEB)

    Kitajima, Kazuhiro, E-mail: kitajima@med.kobe-u.ac.jp [Department of Radiology, Kobe University Graduate School of Medicine, 7-5-2, Kusunoki-cho, Chuo-ku, Kobe, Hyogo 650-0017 (Japan); Maeda, Tetsuo; Ohno, Yoshiharu [Department of Radiology, Kobe University Graduate School of Medicine, 7-5-2, Kusunoki-cho, Chuo-ku, Kobe, Hyogo 650-0017 (Japan); Division of Radiology, Kobe University Hospital, Kobe (Japan); Yoshikawa, Takeshi [Department of Radiology, Kobe University Graduate School of Medicine, 7-5-2, Kusunoki-cho, Chuo-ku, Kobe, Hyogo 650-0017 (Japan); Konishi, Minoru [Division of Radiology, Kobe University Hospital, Kobe (Japan); Kanda, Tomonori; Onishi, Yumiko; Matsumoto, Keiko; Koyama, Hisanobu; Takenaka, Daisuke; Sugimura, Kazuro [Department of Radiology, Kobe University Graduate School of Medicine, 7-5-2, Kusunoki-cho, Chuo-ku, Kobe, Hyogo 650-0017 (Japan)

    2011-11-15

    Objective: To compare the capability of 320-detector row CT (area-detector CT: ADCT) with step-and-shoot scan protocol for small abdominal vasculature assessment with that of 64-detector row CT with helical scan protocol. Materials and methods: Total of 60 patients underwent contrast-enhanced abdominal CT for preoperative assessment. Of all, 30 suspected to have lung cancer underwent ADCT using step-and-shoot scan protocol. The other 30 suspected to have renal cell carcinoma underwent 64-MDCT using helical scan protocol. Two experienced radiologists independently assessed inferior epigastric, hepatic subsegmental (in the segment 8), mesenteric marginal (Griffith point) and inferior phrenic arteries by using 5-point visual scoring systems. Kappa analysis was used for evaluation of interobserver agreement. To compare the visualization capability of the two systems, the Mann-Whitney U-test was used to compare the scores for each of the arteries. Results: Overall interobserver agreements for both systems were almost perfect ({kappa} > 0.80). Visualization scores for inferior epigastric and mesenteric arteries were significantly higher for ADCT than for 64-detector row CT (p < 0.05). No significant difference was found for hepatic subsegmental and inferior phrenic arteries. Conclusion: Small abdominal vasculature assessment by ADCT with step-and-shoot scan protocol is potentially equal to or better than that by 64-detector row CT with helical scan protocol.

  5. Capability of abdominal 320-detector row CT for small vasculature assessment compared with that of 64-detector row CT

    International Nuclear Information System (INIS)

    Kitajima, Kazuhiro; Maeda, Tetsuo; Ohno, Yoshiharu; Yoshikawa, Takeshi; Konishi, Minoru; Kanda, Tomonori; Onishi, Yumiko; Matsumoto, Keiko; Koyama, Hisanobu; Takenaka, Daisuke; Sugimura, Kazuro

    2011-01-01

    Objective: To compare the capability of 320-detector row CT (area-detector CT: ADCT) with step-and-shoot scan protocol for small abdominal vasculature assessment with that of 64-detector row CT with helical scan protocol. Materials and methods: Total of 60 patients underwent contrast-enhanced abdominal CT for preoperative assessment. Of all, 30 suspected to have lung cancer underwent ADCT using step-and-shoot scan protocol. The other 30 suspected to have renal cell carcinoma underwent 64-MDCT using helical scan protocol. Two experienced radiologists independently assessed inferior epigastric, hepatic subsegmental (in the segment 8), mesenteric marginal (Griffith point) and inferior phrenic arteries by using 5-point visual scoring systems. Kappa analysis was used for evaluation of interobserver agreement. To compare the visualization capability of the two systems, the Mann-Whitney U-test was used to compare the scores for each of the arteries. Results: Overall interobserver agreements for both systems were almost perfect (κ > 0.80). Visualization scores for inferior epigastric and mesenteric arteries were significantly higher for ADCT than for 64-detector row CT (p < 0.05). No significant difference was found for hepatic subsegmental and inferior phrenic arteries. Conclusion: Small abdominal vasculature assessment by ADCT with step-and-shoot scan protocol is potentially equal to or better than that by 64-detector row CT with helical scan protocol.

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

    International Nuclear Information System (INIS)

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

    2005-01-01

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

  7. Evaluation of various image reconstruction parameters in lower extremity stents using multidetector-row CT angiography: initial findings

    International Nuclear Information System (INIS)

    Heuschmid, Martin; Wiesinger, Benjamin; Tepe, Gunnar; Luz, Oliver; Kopp, Andreas F.; Claussen, Claus D.; Duda, Stephan H.

    2007-01-01

    Image quality, visible lumen and patency of lower limb stents was assessed by multidetector-row computed tomography (MDCT) angiography using various reconstruction parameters and the results compared with conventional angiography. Fourteen patients (25 stents) were evaluated. From MDCT datasets, axial and coronal oblique reformations were reconstructed using differing reconstruction parameters (slice thickness, kernel, views). Artifacts and image quality were assessed using a five-degree scale (1=excellent, 5=poor). Visible stent diameter was measured. Stenosis severity was compared with calibrated catheter angiography. The image quality of medium and sharp image kernels were good/fair (1.9-2.4), while smooth kernel provided only acceptable/poor image quality (3.9-4.4). Coronal oblique images were rated superior to assess in-stent lumen rather than axial. Using medium and sharp kernels, the visible stent lumen was significantly greater than using smooth kernel (P<0.001). thirteen out of fourteen patients (24/25 stents) were correctly classified as patent. In one patient, in-stent stenosis (≥50%) was falsely diagnosed using CT angiography (CTA) with smooth kernel and was, therefore, rated as false positive. Coronal oblique views, as well as medium and sharp kernels, have shown the best results regarding image quality to assess stent patency in the lower limb. Therefore, MDCT could be a valuable non-invasive modality for stent imaging in the peripheral vasculature. (orig.)

  8. Dual-phase contrast enhancement multi-slice CT in grading pancreatic neuroendocrine tumors

    International Nuclear Information System (INIS)

    Zhou Yan; Liu Jianyu; Zhu Xiang

    2013-01-01

    Objective: To evaluate characteristic clinical and imaging findings of pancreatic neuroendocrine tumors (NET) in dual-phase contrast enhancement MSCT. Methods: The dual-phase contrast enhancement MSCT images of 23 lesions in 20 patients with histologically confirmed pancreatic NET were studied retrospectively. Their clinical presentations, imaging characters as well as the intensities of lesions and normal pancreas in each phase were measured, and the following indices were calculated. First, the absolute enhancement of lesions, including the increasing of CT value of the maximum enhancement area within a tumor in arterial phase, that was named A1 in short, and that of the minimum enhancement area was labeled as A2. The same ROI measured increasing CT values in portal venous phase was labeled as V1 and V2 respectively. Secondly, the relatively enhancement indices comparing with the normal pancreas in the same patient within the same phase were calculated. This included the differences between the maximum, as well as the minimum, enhancement areas of tumors and the normal pancreas in arterial phase, which was named as AP1 and AP2 respectively, and those differences in portal venous phase, which were labeled as VP1 and VP2 respectively. All of the tumors were graded as G1 to G3 according to the WHO classification in 2010. A Kruskal Wallis test were performed to compare differences of tumor diameters and the enhancement indices. The change trend of enhancement indices varying with pathology grading were described. Fisher exact test was used to find differences of clinical and imaging characters. Results: Twenty-three lesions in 20 patients included 13 lesions in grade 1 (G1), 8 in G2, and 2 in G3. Among the 10 patients with G1 NET, 7 of them had no endocrine symptoms, while the other 3 had endocrine symptoms. Six of them had no abdominal pain, while 4 of them complained of it. All of the 10 patients with G1 NET had no hepatic metastasis. Among 8 patients with G2 NET

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

    International Nuclear Information System (INIS)

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

    2009-01-01

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

  10. The optimization of scan timing for contrast-enhanced magnetic resonance angiography

    International Nuclear Information System (INIS)

    Lee, Jong Min; Chang, Yong Min; Ryeom, Hun Kyu; Lee, Sang Kwon; Kim, Yong Sun; Kang, Duk Sik; Tirman, Philip J.

    2000-01-01

    To determine the optimal scan timing for contrast-enhanced magnetic resonance angiography and to evaluate a new timing method based on the arteriovenous circulation time. Eighty-nine contrast-enhanced magnetic resonance angiographic examinations were performed mainly in the extremities. A 1.5T scanner with a 3-D turbo-FLASH sequence was used, and during each study, two consecutive arterial phases and one venous phase were acquired. Scan delay time was calculated from the time-intensity curve by the traditional (n = 48) and/or the new (n = 41) method. This latter was based on arteriovenous circulation time rather than peak arterial enhancement time, as used in the traditional method. The numbers of first-phase images showing a properly enhanced arterial phase were compared between the two methods. Mean scan delay time was 5.4 sec longer with the new method than with the traditional. Properly enhanced first-phase images were found in 65% of cases (31/48) using the traditional timing method, and 95% (39/41) using the new method. When cases in which there was mismatch between the target vessel and the Time-intensity curve acquisition site are excluded, erroneous acquisition occurred in seven cases with the traditional method, but in none with the new method. The calculation of scan delay time on the basis of arteriovenous circulation time provides better timing for arterial phase acquisition than the traditional method

  11. Usefulness of preoperative chest multidetector CT for evaluation of breast cancer: comparison with breast MRI

    International Nuclear Information System (INIS)

    Chang, Yun Woo; Kim, Dong Hun; Lee, Min Hyuk

    2005-01-01

    To evaluate the efficacy of chest multidetector-row helical computed tomography (MDCT) in detecting breast cancer in preoperative metastasis work-ups and to assess the accuracy of MDCT compared with magnetic resonance imaging (MRI). MDCT were performed on 69 consecutive patients with 94 lesions of histologically proven breast cancer. Retrospectively, two radiologists performed a blind review of the MDCT images for margin, shape, mass enhancement pattern and the enhancing distribution of non-mass lesions with consensus. CT attenuation values were measured in the average HU on pre-enhancing and enhanced CT in gland, fat, muscle, and in masses with the largest region of interest (ROI). MDCT finding were analyzed and compared with breast MRI. Of the 91 breast lesions detected on MDCT, 64 were mass lesions and 24 were non-mass lesions on enhancement, 86 lesions were malignant and 5 were benign. Three pathologically proven malignant masses were not detected on MDCT. Positive predictive value, false positive rate and false negative rate were 94.5%, 5.3%, 3.2% respectively. The highly predictive features for malignancy were a spiculated or irregular margin, an irregular of round shape, and a heterogeneously or rim enhanced mass. Another highly predictive feature for malignancy was linear or segmentally distributed enhancing non-mass lesions. The CT values of masses in pre-enhanced scans were 38.6 ± 7.9 HU; these values increased to 110.9 ± 26.6 HU after contrast injection (90 sec). The attenuation values from enhancing CT of malignant lesions were significantly higher than those of non-enhancing lesions. The depiction of enhancing masses on MDCT compared with MR imaging were 88.6%. The extension of malignancy were equally well correlated MDCT with MR imaging. The diagnostic value of chest MDCT for preoperative staging is comparable with MR imaging for the detection and extension of lesions. Therefore, chest MDCT of breast cancer can add to the information obtained from

  12. Regenerative nodules in patients with chronic Budd-Chiari syndrome: A longitudinal study using multiphase contrast-enhanced multidetector CT

    International Nuclear Information System (INIS)

    Flor, Nicola; Zuin, Massimo; Brovelli, Francesca; Maggioni, Marco; Tentori, Augusta; Sardanelli, Francesco; Cornalba, Gian Paolo

    2010-01-01

    Objective: Our aim was to evaluate the serial evolution of regenerative nodules in patients with Budd-Chiari syndrome (BCS) treated with portal-systemic shunts, using multiphasic multidetector computed tomography (MDCT). Materials and methods: Five patients each underwent three MDCT exams over an extended period ranging from 36 to 42 months. Two radiologists in consensus retrospectively reviewed each exam for each patient. Individual nodules were grouped according to size (size I: nodules with diameter ≤15 mm; size II: >15 mm but <30 mm; size III: ≥30 mm), pattern of enhancement (A: homogeneously hypervascular or B: with central scar), and segmental location. Four nodules classified as size II, which increased in size over time, were needle-biopsied. Results: We detected 61 nodules at the first exam, 66 nodules at the second exam (7 nodules disappeared and 12 new nodules), and 85 nodules at the third exam (8 disappeared and 27 new) for a total of 212 findings. Nodules were mostly found in the right hepatic lobe. Fourteen of the 15 nodules that disappeared over time were size I and enhancement pattern A. At unenhanced MDCT, 204 (96%) of the 212 findings were isodense. Overall, 100 nodules, including the 61 initially detected, were considered newly diagnosed; of these 84 (84%) were size I and pattern A. Of 57 nodules considered size I and pattern A at the first or second exam, 24 (42%) changed to pattern B at the third exam and either size II (n = 18) or III (n = 6). The four biopsied nodules were each confirmed as benign regenerative nodule. No patient developed HCC at 5-year follow-up period. Conclusion: Hepatic nodules in BCS patients not only increase in number over time but may also increase in size and develop a central scar.

  13. Visualization of neonatal coronary arteries on multidetector row CT: ECG-gated versus non-ECG-gated technique

    International Nuclear Information System (INIS)

    Tsai, I.C.; Lee, Tain; Chen, Min-Chi; Fu, Yun-Ching; Jan, Sheng-Lin; Wang, Chung-Chi; Chang, Yen

    2007-01-01

    Multidetector CT (MDCT) seems to be a promising tool for detection of neonatal coronary arteries, but whether the ECG-gated or non-ECG-gated technique should be used has not been established. To compare the detection rate and image quality of neonatal coronary arteries on MDCT using ECG-gated and non-ECG-gated techniques. Twelve neonates with complex congenital heart disease were included. The CT scan was acquired using an ECG-gated technique, and the most quiescent phase of the RR interval was selected to represent the ECG-gated images. The raw data were then reconstructed without the ECG signal to obtain non-ECG-gated images. The detection rate and image quality of nine coronary artery segments in the two sets of images were then compared. A two-tailed paired t test was used with P values <0.05 considered as statistically significant. In all coronary segments the ECG-gated technique had a better detection rate and produced images of better quality. The difference between the two techniques ranged from 25% in the left main coronary artery to 100% in the distal right coronary artery. For neonates referred for MDCT, if evaluation of coronary artery anatomy is important for the clinical management or surgical planning, the ECG-gated technique should be used because it can reliably detect the coronary arteries. (orig.)

  14. Phase contrast enhanced high resolution X-ray imaging and tomography of soft tissue

    International Nuclear Information System (INIS)

    Jakubek, Jan; Granja, Carlos; Dammer, Jiri; Hanus, Robert; Holy, Tomas; Pospisil, Stanislav; Tykva, Richard; Uher, Josef; Vykydal, Zdenek

    2007-01-01

    A tabletop system for digital high resolution and high sensitivity X-ray micro-radiography has been developed for small-animal and soft-tissue imaging. The system is based on a micro-focus X-ray tube and the semiconductor hybrid position sensitive Medipix2 pixel detector. Transmission radiography imaging, conventionally based only on absorption, is enhanced by exploiting phase-shift effects induced in the X-ray beam traversing the sample. Phase contrast imaging is realized by object edge enhancement. DAQ is done by a novel fully integrated USB-based readout with online image generation. Improved signal reconstruction techniques make use of advanced statistical data analysis, enhanced beam hardening correction and direct thickness calibration of individual pixels. 2D and 3D micro-tomography images of several biological samples demonstrate the applicability of the system for biological and medical purposes including in-vivo and time dependent physiological studies in the life sciences

  15. Focal hepatic lesions: contrast-enhancement patterns at pulse-inversion harmonic US using a microbubble contrast agent

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Eun-A; Yoon, Kwon-Ha; Lee, Young-Hwan; Kim, Hye-Won; Juhng, Seon-Kwan; Won, Jong-Jin [Wonkwang University, Iksan (Korea, Republic of)

    2003-12-15

    To analyze the contrast-enhancement patterns obtained at pulse-inversion harmonic imaging (PIHI) of focal hepatic lesions, and to thus determine tumor vascularity and the acoustic emission effect. We reviewed pulse-inversion images in 90 consecutive patients with focal hepatic lesions, namely hepatocellular carcinoma (HHC) (n=43), metastases (n=30), and hemangioma (n=17). Vascular and delayed phase images were obtained immediately and five minutes following the injection of a microbubble contrast agent. Tumoral vascularity at vascular phase imaging and the acoustic emission effect at delayed phase imaging were each classified as one of four patterns. Vascular phase images depicted internal vessels in 93% of HCCs, marginal vessels in 83% of metastases, and peripheral enhancement in 71% of hemangiomas. Delayed phase images showed inhomogeneous enhancement in 86% of HCCs; hypoechoic, decreased enhancement in 93% of metastases; and hypoechoic and reversed echogenicity in 65% of hemangiomas. Vascular and delayed phase enhancement patterns were associated with a specificity of 91% or greater, and 92% or greater, respectively, and with positive predictive values of 71% or greater, and 85% or greater, respectively. Contrast-enhancement patterns depicting tumoral vascularity and the acoustic emission effect at PIHI can help differentiate focal hepatic lesions.

  16. Phase-contrast X-ray CT

    Energy Technology Data Exchange (ETDEWEB)

    Momose, Atsushi [Hitachi Ltd., Saitama (Japan). Advanced Research Laboratory; Takeda, Tohoru; Itai, Yuji

    1995-12-01

    Phase-contrast X-ray computed tomography (CT) enabling the observation of biological soft tissues without contrast enhancement has been developed. The X-ray phase shift caused by an object is measured and input to a standard CT reconstruction algorithm. A thousand times increase in the image sensitivity to soft tissues is achieved compared with the conventional CT using absorption contrast. This is because the X-ray phase shift cross section of light elements is about a thousand times larger than the absorption cross section. The phase shift is detected using an X-ray interferometer and computer analyses of interference patterns. Experiments were performed using a synchrotron X-ray source. Excellent image sensitivity is demonstrated in the observation of cancerous rabbit liver. The CT images distinguish cancer lesion from normal liver tissue and, moreover, visualize the pathological condition in the lesion. Although the X-ray energy employed and the present observation area size are not suitable for medical applications as they are, phase-contrast X-ray CT is promising for investigating the internal structure of soft tissue which is almost transparent for X-rays. The high sensitivity also provides the advantage of reducing X-ray doses. (author).

  17. Microbubbles as contrast agent for in-line x-ray phase-contrast imaging

    International Nuclear Information System (INIS)

    Xi Yan; Zhao Jun; Tang Rongbiao; Wang Yujie

    2011-01-01

    In the present study, we investigated the potential of gas-filled microbubbles as contrast agents for in-line x-ray phase-contrast imaging (PCI) in biomedical applications. When imaging parameters are optimized, the microbubbles function as microlenses that focus the incoming x-rays to form bright spots, which can significantly enhance the image contrast. Since microbubbles have been shown to be safe contrast agents in clinical ultrasonography, this contrast-enhancement procedure for PCI may have promising utility in biomedical applications, especially when the dose of radiation is a serious concern. In this study, we performed both numerical simulations and ex vivo experiments to investigate the formation of the contrast and the effectiveness of microbubbles as contrast agents in PCI.

  18. Sensitivity and accuracy of volumetry of pulmonary nodules on low-dose 16- and 64-row multi-detector CT: an anthropomorphic phantom study

    Energy Technology Data Exchange (ETDEWEB)

    Xie, Xueqian; Zhao, Yingru; Ooijen, Peter M.A. van; Vliegenthart, Rozemarijn [University of Groningen, University Medical Center Groningen, Department of Radiology, EB44, P.O. Box 30.001, Groningen (Netherlands); University of Groningen, University Medical Center Groningen, Center for Medical Imaging-North East Netherlands, Department of Radiology, Groningen (Netherlands); Snijder, Roland A.; Greuter, Marcel J.W. [University of Groningen, University Medical Center Groningen, Department of Radiology, EB44, P.O. Box 30.001, Groningen (Netherlands); Jong, Pim A. de [University Medical Center Utrecht, Department of Radiology, Utrecht (Netherlands); Oudkerk, Matthijs [University of Groningen, University Medical Center Groningen, Center for Medical Imaging-North East Netherlands, Department of Radiology, Groningen (Netherlands); Bock, Geertruida H. de [University of Groningen, University Medical Center Groningen, Department of Epidemiology, Groningen (Netherlands)

    2013-01-15

    To assess the sensitivity of detection and accuracy of volumetry by manual and semi-automated quantification of artificial pulmonary nodules in an anthropomorphic thoracic phantom on low-dose CT. Fifteen artificial spherical nodules (diameter 3, 5, 8, 10 and 12 mm; CT densities -800, -630 and +100 HU) were randomly placed inside an anthropomorphic thoracic phantom. The phantom was examined on 16- and 64-row multidetector CT with a low-dose protocol. Two independent blinded observers screened for pulmonary nodules. Nodule diameter was measured manually, and volume calculated. For solid nodules (+100 HU), diameter and volume were also evaluated by semi-automated software. Differences in observed volumes between the manual and semi-automated method were evaluated by a t-test. Sensitivity was 100 % for all nodules of >5 mm and larger, 60-80 % for solid and 0-20 % for non-solid 3-mm nodules. No false-positive nodules but high inter-observer reliability and inter-technique correlation were found. Volume was underestimated manually by 24.1 {+-} 14.0 % for nodules of any density, and 26.4 {+-} 15.5 % for solid nodules, compared with 7.6 {+-} 8.5 % (P < 0.01) semi-automatically. In an anthropomorphic phantom study, the sensitivity of detection is 100 % for nodules of >5 mm in diameter. Semi-automated volumetry yielded more accurate nodule volumes than manual measurements. (orig.)

  19. Tracheal compression due to an elongated aortic arch in patients with congenital heart disease: evaluation using multidetector-row CT

    Energy Technology Data Exchange (ETDEWEB)

    Watanabe, Noriko; Hayabuchi, Yasunobu; Inoue, Miki; Sakata, Miho; Nabo, Manal Mohamed Helmy; Nakagawa, Ryuji; Saijo, Takahiko; Kagami, Shoji [University of Tokushima, Department of Pediatrics, Tokushima (Japan)

    2009-10-15

    The airway can become obstructed as a result of compression by an elongated aortic arch. In this study we evaluated tracheal compression using multidetector-row CT in patients with congenital heart disease and an elongated aortic arch. The trachea was measured at the level of the aortic arch in 205 children and young adults and then the severity of tracheal compression was determined by measuring the tracheal diameter ratio (short axis diameter/long axis diameter). Patients were divided as follows: group I (normal aortic arch; n=166), group II (transversely running aortic arch; n=22), and group III (elongated aortic arch; n=17). From the viewpoint of the relationship of the great arteries, group II had D-malposition, and group III had L-malposition. Age, height, weight and body surface area were significantly correlated with the short and long axis diameter in group I. There was a negative correlation between tracheal diameter ratio and the physical size parameters. The tracheal diameter ratio in group III was 0.50{+-}0.13, which was significantly lower than in groups I and II (P<0.01 and 0.05, respectively). Even apparently asymptomatic patients with an elongated aortic arch can have tracheal compression. An elongated aortic arch may be a useful predictor of tracheal compression. (orig.)

  20. Adrenal and nephrogenic hypertension: an image quality study of low tube voltage, low-concentration contrast media combined with adaptive statistical iterative reconstruction.

    Science.gov (United States)

    Li, Zhen; Li, Qiong; Shen, Yaqi; Li, Anqin; Li, Haojie; Liang, Lili; Hu, Yao; Hu, Xuemei; Hu, Daoyu

    2016-09-01

    The aim of this study was to investigate the effect of using low tube voltage, low-concentration contrast media and adaptive statistical iterative reconstruction (ASIR) for reducing the radiation and iodine contrast doses in adrenal and nephrogenic hypertension patients. A total of 148 hypertension patients who were suspected for adrenal lesions or renal artery stenoses were assigned to two groups and. Group A (n=74) underwent a low tube voltage, low molecular weight dextran enhanced multi-detector row spiral CT (MDCT) (80 kVp, 270 mg I/mL contrast agent), and the raw data were reconstructed with standard filtered back projection (FBP) and ASIR at four different levels of blending (20%, 40%, 60% and 80%, respectively). The control group (Group B, n=74) underwent conventional MDCT (120 kVp, 370 mg I/mL contrast agent), and the data were reconstructed with FBP. The CT values, standard deviation (SD), signal-noise-ratio (SNR) and contrast-noise-ratio (CNR) were measured in the renal vessels, normal adrenal tissue, adrenal neoplasms and subcutaneous fat. The volume CT dose index (CTDIvol ) and dose length product (DLP) were recorded, and an effective dose (ED) was obtained. Two-tailed independent t-tests, paired Chi-square tests and Kappa consistency tests were used for statistical analysis of the data. The CTDIvol , DLP and total iodine dose in group A were decreased by 47.8%, 49.0% and 26.07%, respectively, compared to group B (Pcontrast media and 60% ASIR provides similar enhancement and image quality with a reduced radiation dose and contrast iodine dose. © 2016 John Wiley & Sons Ltd.

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

    International Nuclear Information System (INIS)

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

    2012-01-01

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

  2. Evaluation of residual hepatocellular carcinoma after transcatheter arterial chemoembolization: Comparison between contrast-enhanced helical CT and contrast-enhanced power doppler ultrasonography

    International Nuclear Information System (INIS)

    Kim, Seung Hoon; Lim, Hyo Keun; Lee, Won Jae

    2001-01-01

    To evaluate the effectiveness of contrast-enhanced helical CT and contrast-enhanced power doppler ultrasonography (PDUS) in assessing the therapeutic effect of transcatheter arterial chemoembolization (TACE) in hepatocellular carcinomas (HCCs). The follow-up contrast-enhanced helical CT and contrast-enhanced PDUS were performed for twenty-nine nodular HCCs from twelve patients previously treated with TACE. We defined the residual HCCs as intratumoral enhancing area on contrast-enhanced helical CT and color signal on contrast-enhanced PDUS. The interval between two examinations was less than 2 weeks (mean, 9 days). Two radiologists evaluated two examinations by consensus, and the results of these two examination were compared with the findings of other examinations including CT, angiography, and/or pathology to calculate the sensitivity, specificity and accuracy of two examinations. Of the 29 HCCs, 20 had residual HCCs whereas no residual HCCs in 9 HCCs on pathologic examination and/or follow-up radiologic study. The sensitivity, sensitivity and accuracy of contrast-enhanced helical CT were 65 (13/20), 89 (8/9), and 72% (21/29) while those of contrast-enhanced PDUS were 100 (20/20), 89 (8/9) and 97% (28/29), respectively. A microbubble contrast-enhanced PDUS was more effective in the detection of residual tumor in HCCs following TACE than contrast-enhanced helical CT.

  3. Multidetector computed tomography virtual hysterosalpingography in the investigation of the uterus and fallopian tubes

    International Nuclear Information System (INIS)

    Carrascosa, Patricia; Baronio, Mariano; Capunay, Carlos; Lopez, Elba Martin; Vallejos, Javier; Borghi, Mario; Sueldo, Carlos; Papier, Sergio

    2008-01-01

    Objective: To compare the efficacy of multidetector CT virtual hysterosalpingography (MDCT-VH) with conventional X-ray hysterosalpingography (HSG) in the evaluation of patients with diagnosis of infertility. Methods: Sixty patients with diagnosis of infertility scheduled to perform a HSG, were evaluated with 16-row (n = 50) and 64-row (n = 10) MDCT-VH. In 35 patients the examination was performed without a tenaculum. The HSGs were carried out using standard technique. The HSG and MDCT-VH findings were compared. The duration for both examinations and patient discomfort were documented. The sensitivity and specificity of MDCT-VH for the detection of uterine pathology and tubal obstruction were calculated using the exact binomial method. Agreement between the two methods was assessed by the Cohen's kappa method (k). Results: The mean duration for MDCT-VH (16 and 64-rows) was 5 ± 3 min, whereas for HSG was 28 ± 3. The MDCT-VH without a tenaculum was the procedure with less patient discomfort. Sensitivity, specificity and inter-method agreement for the detection of uterine pathology were 100%, 92% and k = 0.92 for 16-row MDCT-VH and 100%, 100% and k = 1 for 64-row MDCT-VH, respectively. Sensitivity and specificity for detection of tubal obstruction were 80% and 80% for 16-row MDCT-VH and 100% and 100% for 64-row MDCT-VH, respectively; inter-method agreement for the visualization of the tubes was k = 0.54 for 16-row MDCT-VH and k = 1 for 64-row MDCT-VH. Conclusion: This study demonstrated the feasibility of evaluating the female reproductive system by MDCT-VH. 64-Row MDCT-VH could be an alternative diagnostic technique in the infertility workup algorithm. A larger study is in progress to validate these encouraging results

  4. Multidetector computed tomography virtual hysterosalpingography in the investigation of the uterus and fallopian tubes

    Energy Technology Data Exchange (ETDEWEB)

    Carrascosa, Patricia [Diagnostico Maipu, Av. Maipu 1668, Vicente Lopez B1602ABQ, Buenos Aires (Argentina)], E-mail: patriciacarrascosa@diagnosticomaipu.com.ar; Baronio, Mariano [CEGYR, Viamonte 1438, Capital Federal C1055ABB (Argentina); Capunay, Carlos; Lopez, Elba Martin; Vallejos, Javier [Diagnostico Maipu, Av. Maipu 1668, Vicente Lopez B1602ABQ, Buenos Aires (Argentina); Borghi, Mario; Sueldo, Carlos; Papier, Sergio [CEGYR, Viamonte 1438, Capital Federal C1055ABB (Argentina)

    2008-09-15

    Objective: To compare the efficacy of multidetector CT virtual hysterosalpingography (MDCT-VH) with conventional X-ray hysterosalpingography (HSG) in the evaluation of patients with diagnosis of infertility. Methods: Sixty patients with diagnosis of infertility scheduled to perform a HSG, were evaluated with 16-row (n = 50) and 64-row (n = 10) MDCT-VH. In 35 patients the examination was performed without a tenaculum. The HSGs were carried out using standard technique. The HSG and MDCT-VH findings were compared. The duration for both examinations and patient discomfort were documented. The sensitivity and specificity of MDCT-VH for the detection of uterine pathology and tubal obstruction were calculated using the exact binomial method. Agreement between the two methods was assessed by the Cohen's kappa method (k). Results: The mean duration for MDCT-VH (16 and 64-rows) was 5 {+-} 3 min, whereas for HSG was 28 {+-} 3. The MDCT-VH without a tenaculum was the procedure with less patient discomfort. Sensitivity, specificity and inter-method agreement for the detection of uterine pathology were 100%, 92% and k = 0.92 for 16-row MDCT-VH and 100%, 100% and k = 1 for 64-row MDCT-VH, respectively. Sensitivity and specificity for detection of tubal obstruction were 80% and 80% for 16-row MDCT-VH and 100% and 100% for 64-row MDCT-VH, respectively; inter-method agreement for the visualization of the tubes was k = 0.54 for 16-row MDCT-VH and k = 1 for 64-row MDCT-VH. Conclusion: This study demonstrated the feasibility of evaluating the female reproductive system by MDCT-VH. 64-Row MDCT-VH could be an alternative diagnostic technique in the infertility workup algorithm. A larger study is in progress to validate these encouraging results.

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

    Directory of Open Access Journals (Sweden)

    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.

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

    International Nuclear Information System (INIS)

    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

    2013-01-01

    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. (author)

  7. Histopathologic diversity of gastric cancers: Relationship between enhancement pattern on dynamic contrast-enhanced CT and histological type.

    Science.gov (United States)

    Tsurumaru, Daisuke; Miyasaka, Mitsutoshi; Muraki, Toshio; Nishie, Akihiro; Asayama, Yoshiki; Oki, Eiji; Oda, Yoshinao; Honda, Hiroshi

    2017-12-01

    To evaluate the diagnostic value of contrast-enhanced computed tomography gastrography (CE-CTG) to predict the histological type of gastric cancer. We analyzed 47 consecutive patients with resectable advanced gastric cancer preoperatively evaluated by multiphasic dynamic contrast-enhanced CT. Two radiologists independently reviewed the CT images and they determined the peak enhancement phase, and then measured the CT attenuation value of the gastric lesion for each phase. The histological types of gastric cancers were assigned to three groups as differentiated-type, undifferentiated-type, and mixed-type. We compared the peak enhancement phase of the three types and compared the CT attenuation values in each phase. The peak enhancement was significantly different between the three types of gastric cancers for both readers (reader 1, p=0.001; reader 2, p=0.009); most of the undifferentiated types had peak enhancement in the delayed phase. The CT attenuation values of undifferentiated type were significantly higher than those of differentiated or mixed type in the delayed phase according to both readers (reader 1, p=0.002; reader 2, p=0.004). CE-CTG could provide helpful information in diagnosing the histological type of gastric cancers preoperatively. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. Single-source dual-energy spectral multidetector CT of pancreatic adenocarcinoma: Optimization of energy level viewing significantly increases lesion contrast

    International Nuclear Information System (INIS)

    Patel, B.N.; Thomas, J.V.; Lockhart, M.E.; Berland, L.L.; Morgan, D.E.

    2013-01-01

    Aim: To evaluate lesion contrast in pancreatic adenocarcinoma patients using spectral multidetector computed tomography (MDCT) analysis. Materials and methods: The present institutional review board-approved, Health Insurance Portability and Accountability Act of 1996 (HIPAA)-compliant retrospective study evaluated 64 consecutive adults with pancreatic adenocarcinoma examined using a standardized, multiphasic protocol on a single-source, dual-energy MDCT system. Pancreatic phase images (35 s) were acquired in dual-energy mode; unenhanced and portal venous phases used standard MDCT. Lesion contrast was evaluated on an independent workstation using dual-energy analysis software, comparing tumour to non-tumoural pancreas attenuation (HU) differences and tumour diameter at three energy levels: 70 keV; individual subject-optimized viewing energy level (based on the maximum contrast-to-noise ratio, CNR); and 45 keV. The image noise was measured for the same three energies. Differences in lesion contrast, diameter, and noise between the different energy levels were analysed using analysis of variance (ANOVA). Quantitative differences in contrast gain between 70 keV and CNR-optimized viewing energies, and between CNR-optimized and 45 keV were compared using the paired t-test. Results: Thirty-four women and 30 men (mean age 68 years) had a mean tumour diameter of 3.6 cm. The median optimized energy level was 50 keV (range 40–77). The mean ± SD lesion contrast values (non-tumoural pancreas – tumour attenuation) were: 57 ± 29, 115 ± 70, and 146 ± 74 HU (p = 0.0005); the lengths of the tumours were: 3.6, 3.3, and 3.1 cm, respectively (p = 0.026); and the contrast to noise ratios were: 24 ± 7, 39 ± 12, and 59 ± 17 (p = 0.0005) for 70 keV, the optimized energy level, and 45 keV, respectively. For individuals, the mean ± SD contrast gain from 70 keV to the optimized energy level was 59 ± 45 HU; and the mean ± SD contrast gain from the optimized energy level to 45 ke

  9. Contrast-enhanced computed tomography does not improve the diagnostic value of parathyroid dual-phase MIBI SPECT/CT

    DEFF Research Database (Denmark)

    Andersen, Trine B; Aleksyniene, Ramune; Boldsen, Søren K

    2018-01-01

    OBJECTIVE: The aim of this study was to investigate the contribution of contrast-enhanced computed tomography (CE-CT) to the localization of parathyroid adenomas compared with the dual-phase Tc-99m MIBI SPECT with low-dose CT (LD-CT). PATIENTS AND METHODS: This retrospective study included...... consecutive patients with primary hyperparathyroidism who underwent a preoperative dual-phase MIBI SPECT/CT followed by surgical resection. The standard of care was dual-phase MIBI SPECT/CT, acquired with LD-CT in the early phase and CE-CT in the late phase (SPECT/CE-CT). The presence and localization...... of positive sites were extracted from study reports. To examine the role of CE-CT, patient cases were independently re-reviewed, with the early LD-CT fused with early and late SPECT (SPECT/LD-CT). The two SPECT/CT methods were compared for sensitivity, and the positive predictive value and histopathology were...

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

    DEFF Research Database (Denmark)

    Thomsen, Henrik S; Morcos, Sameh K

    2009-01-01

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

  11. Evaluation of radiation dose in 64-row whole-body CT of multiple injured patients compared to 4-row CT

    International Nuclear Information System (INIS)

    Harrieder, A.; Geyer, L.L.; Koerner, M.; Deak, Z.; Wirth, S.; Reiser, M.; Linsenmaier, U.

    2012-01-01

    Purpose: To evaluate radiation exposure in whole-body CT (WBCT) of multiple injured patients comparing 4-row multidetector computed tomography (MDCT) to 64-row MDCT. Materials and Methods: 200 WBCT studies were retrospectively evaluated: 92 4-row MDCT scans and 108 64-row MDCT scans. Each CT protocol was optimized for the particular CT system. The scan length, CT dose index (CTDI), and dose length product (DLP) were recorded and analyzed for radiation exposure. The mean effective dose was estimated based on conversion factors. Student's t-test was used for statistical analysis. Results: The mean CTDI vol values (mGy) of the thorax and abdomen were significantly reduced with 64-row MDCT (10.2 ± 2.5 vs. 11.4 ± 1.4, p < 0.001; 14.2 ± 3.7 vs. 16.1 ± 1.7, p < 0.001). The DLP values (mGy x cm) of the head and thorax were significantly increased with 64-row MDCT (1305.9 ± 201.1 vs. 849.8 ± 90.9, p < 0,001; 504.4 ± 134.4 vs. 471.5 ± 74.1, p = 0.030). The scan lengths (mm) were significantly increased with 64-row MDCT: head 223.6 ± 35.8 vs. 155.5 ± 12.3 (p < 0.001), thorax 427.4 ± 44.5 vs. 388.3 ± 57.5 (p < 0.001), abdomen 520.3 ± 50.2 vs. 490.8 ± 51.6 (p < 0.001). The estimated mean effective doses (mSv) were 22.4 ± 2.6 (4-row MDCT) and 24.1 ± 4.6 (64-row MDCT; p = 0.001), resulting in a percentage increase of 8 %. Conclusion: The radiation dose per slice of the thorax and abdomen can be significantly decreased by using 64-row MDCT. Due to the technical advances of modern 64-row MDCT systems, the scan field can be adapted to the clinical demands and, if necessary, enlarged without time loss. As a result, the estimated mean effective dose might be increased in WBCT. (orig.)

  12. Contrast enhanced ultrasound in liver imaging

    International Nuclear Information System (INIS)

    Nielsen, Michael Bachmann; Bang, Nanna

    2004-01-01

    Ultrasound contrast agents were originally introduced to enhance the Doppler signals when detecting vessels with low velocity flow or when imaging conditions were sub-optimal. Contrast agents showed additional properties, it was discovered that a parenchymal enhancement phase in the liver followed the enhancement of the blood pool. Contrast agents have made ultrasound scanning more accurate in detection and characterization of focal hepatic lesions and the sensitivity is now comparable with CT and MRI scanning. Further, analysis of the transit time of contrast agent through the liver seems to give information on possible hepatic involvement, not only from focal lesions but also from diffuse benign parenchymal disease. The first ultrasound contrast agents were easily destroyed by the energy from the sound waves but newer agents have proved to last for longer time and hereby enable real-time scanning and make contrast enhancement suitable for interventional procedures such as biopsies and tissue ablation. Also, in monitoring the effect of tumour treatment contrast agents have been useful. A brief overview is given on some possible applications and on different techniques using ultrasound contrast agents in liver imaging. At present, the use of an ultrasound contrast agent that allows real-time scanning with low mechanical index is to be preferred

  13. Evaluation of Deep Vein Thrombosis with Multidetector Row CT after Orthopedic Arthroplasty: a Prospective Study for Comparison with Doppler Sonography

    International Nuclear Information System (INIS)

    Byun, Sung Su; Kim, Youn Jeong; Chun, Yong Sun; Kim, Won Hong; Kim, Jeong Ho; Park, Chul Hi

    2008-01-01

    This prospective study evaluated the ability of indirect 16-row multidetector CT venography, in comparison with Doppler sonography, to detect deep vein thrombosis after total hip or knee replacement. Sixty-two patients had undergone orthopedic replacement surgery on a total of 30 hip joints and 54 knee joints. The CT venography (scan delay time: 180 seconds; slice thickness/increment: 2/1.5 mm) and Doppler sonography were performed 8 to 40 days after surgery. We measured the z-axis length of the beam hardening artifact that degraded the image quality so that the presence of deep vein thrombosis couldn't be evaluated on the axial CT images. The incidence and location of deep vein thrombosis was analyzed. The diagnostic performance of the CT venograms was evaluated and compared with that of Doppler sonography as a standard of reference. The z-axis length (mean±standard deviation) of the beam hardening artifact was 4.5±0.8 cm in the arthroplastic knees and 3.9±2.9 cm in the arthroplastic hips. Deep vein thrombosis (DVT) was found in the popliteal or calf veins on Doppler sonography in 30 (48%) of the 62 patients. The CT venography has a sensitivity, specificity, positive predictive value, negative predictive value and accuracy of 90%, 97%, 96%, 91% and 94%, respectively. The ability of CT venography to detect DVT was comparable to that of Doppler sonography despite of beam hardening artifact. Therefore, CT venography is feasible to use as an alternative modality for evaluating postarthroplasty patients

  14. Evaluation of Deep Vein Thrombosis with Multidetector Row CT after Orthopedic Arthroplasty: a Prospective Study for Comparison with Doppler Sonography

    Energy Technology Data Exchange (ETDEWEB)

    Byun, Sung Su; Kim, Youn Jeong; Chun, Yong Sun; Kim, Won Hong [Inha University, College of Medicine, Incheon (Korea, Republic of); Kim, Jeong Ho; Park, Chul Hi [Gachon University, Gil Medical Center, Incheon (Korea, Republic of)

    2008-02-15

    This prospective study evaluated the ability of indirect 16-row multidetector CT venography, in comparison with Doppler sonography, to detect deep vein thrombosis after total hip or knee replacement. Sixty-two patients had undergone orthopedic replacement surgery on a total of 30 hip joints and 54 knee joints. The CT venography (scan delay time: 180 seconds; slice thickness/increment: 2/1.5 mm) and Doppler sonography were performed 8 to 40 days after surgery. We measured the z-axis length of the beam hardening artifact that degraded the image quality so that the presence of deep vein thrombosis couldn't be evaluated on the axial CT images. The incidence and location of deep vein thrombosis was analyzed. The diagnostic performance of the CT venograms was evaluated and compared with that of Doppler sonography as a standard of reference. The z-axis length (mean{+-}standard deviation) of the beam hardening artifact was 4.5{+-}0.8 cm in the arthroplastic knees and 3.9{+-}2.9 cm in the arthroplastic hips. Deep vein thrombosis (DVT) was found in the popliteal or calf veins on Doppler sonography in 30 (48%) of the 62 patients. The CT venography has a sensitivity, specificity, positive predictive value, negative predictive value and accuracy of 90%, 97%, 96%, 91% and 94%, respectively. The ability of CT venography to detect DVT was comparable to that of Doppler sonography despite of beam hardening artifact. Therefore, CT venography is feasible to use as an alternative modality for evaluating postarthroplasty patients.

  15. A concept of row crater enhancement

    International Nuclear Information System (INIS)

    Redpath, B.B.

    1970-01-01

    Linear craters formed by the simultaneous detonation of a row of buried explosives will probably have a wider application than single charges in the explosive excavation of engineering structures. Most cratering experience to date has been with single charges, and an analytical procedure for the design of a row of charges to excavate a crater with a specified configuration has been lacking. There are no digital computer codes having direct application to a row of charges as there are for single charges. This paper derives a simple relationship which can be used to design row charges with some assurance of achieving the desired result and with considerable flexibility in the choice of explosive yield of the individual charges

  16. Effect of contrast-enhanced ultrasound on differential diagnosis of intrahepatic cholangiocarcinoma and arterial phase enhanced hepatic inflammatory lesions

    Institute of Scientific and Technical Information of China (English)

    Shanshan Yin; Qiuli Cui; Kun Yan; Wei Yang; Wei Wu; Liping Bao; Minhua Chen

    2017-01-01

    Objective:To investigate differential diagnosis between intrahepatic cholangiocarcinoma (ICC) and arterial phase enhanced hepatic inflammatory lesions in patients without liver cirrhosis using contrast-enhanced ultrasound (CEUS).Methods:ICC and hepatic inflammatory lesions cases with CEUS and pathological diagnosis between Sep 2013 and Oct 2016 were investigated retrospectively.Imaging features of conventional ultrasound and CEUS were analyzed.The parameters of time intensity curve (TIC),including the arrival time,peak intensity (PI) in the lesions,the starting time for washout,and the intensity difference at 3 min (△I3) after contrast agent infection between the lesion and the liver parenchyma,were compared between ICC and hepatic inflammatory lesions.Results:Twenty-five ICC and fifteen inflammatory patients were included in this study.Seventeen ICC (68.0%) and two inflammatory cases (13.3%) showed bile duct dilatation on conventional ultrasound.Using CEUS,three ICC cases (12.0%) were misdiagnosed as inflammatory lesions and three inflammatory lesions (20.0%) as ICC;two ICC (8.0%) and one inflammatory case (6.7%) could not be made definite diagnosis.Washout started at 34.5±3.5 s and 61.5± 12.9 s for ICC and inflammatory lesions respectively (P<0.001).The intensity difference between lesion and liver parenchyma at 3 min after contrast agent injection was 10.8±3.1 dB in ICC and 4.2±2.3 dB in inflammatory group (P<0.00 1).The sensitivity and specificity differentiating ICC and inflammatory lesions were 76% and 87% if the cut-offvalue of the intensity difference was 7.7 dB.Conclusions:Combined with TIC analysis,and particularly with the characteristic of the early-starting and obvious washout in ICC,CEUS can be useful in differential diagnosis between hepatic inflammatory lesions and ICC.

  17. Generalized phase contrast:

    DEFF Research Database (Denmark)

    Glückstad, Jesper; Palima, Darwin

    Generalized Phase Contrast elevates the phase contrast technique not only to improve phase imaging but also to cross over and interface with diverse and seemingly disparate fields of contemporary optics and photonics. This book presents a comprehensive introduction to the Generalized Phase Contrast...

  18. Contrast enhanced liver MRI in patients with primary sclerosing cholangitis: inverse appearance of focal confluent fibrosis on delayed phase MR images with hepatocyte specific versus extracellular gadolinium based contrast agents.

    Science.gov (United States)

    Husarik, Daniela B; Gupta, Rajan T; Ringe, Kristina I; Boll, Daniel T; Merkle, Elmar M

    2011-12-01

    To assess the enhancement pattern of focal confluent fibrosis (FCF) on contrast-enhanced hepatic magnetic resonance imaging (MRI) using hepatocyte-specific (Gd-EOB-DTPA) and extracellular (ECA) gadolinium-based contrast agents in patients with primary sclerosing cholangitis (PSC). After institutional review board approval, 10 patients with PSC (6 male, 4 female; 33-61 years) with 13 FCF were included in this retrospective study. All patients had a Gd-EOB-DTPA-enhanced liver MRI exam, and a comparison ECA-enhanced MRI. On each T1-weighted dynamic dataset, the signal intensity (SI) of FCF and the surrounding liver as well as the paraspinal muscle (M) were measured. In the Gd-EOB-DTPA group, hepatocyte phase images were also included. SI FCF/SI M, SI liver/SI M, and [(SI liver - SI FCF)/SI liver] were compared between the different contrast agents for each dynamic phase using the paired Student's t-test. There was no significant difference in SI FCF/SI M in all imaging phases. SI liver/SI M was significantly higher for the Gd-EOB-DTPA group in the delayed phase (P DTPA group, mean [(SI liver - SI FCF)/SI liver] were as follows (values for ECA group in parentheses): unenhanced phase: 0.26 (0.26); arterial phase: 0.01 (-0.31); portal venous phase (PVP): -0.05 (-0.26); delayed phase (DP): 0.14 (-0.54); and hepatocyte phase: 0.26. Differences were significant for the DP (P DTPA-enhanced images. Copyright © 2011 AUR. Published by Elsevier Inc. All rights reserved.

  19. Acute pulmonary embolism: prediction of cor pulmonale and short-term patient survival from assessment of cardiac dimensions in routine multidetector-row CT

    International Nuclear Information System (INIS)

    Engeike, C.; Rummeny, E.; Marten, K.

    2006-01-01

    Purpose: evaluation of the prognostic value of morphological cardiac parameters in patients with suspected and incidental acute pulmonary embolism (PE) using multidetector-row chest CT (MSCT). Materials and methods: 2335 consecutive MSCT scans were evaluated for the presence of PE. The arterial enhancement and analysability of pulmonary arteries and the heart were assessed as parameters of the scan quality. The diastolic right and left ventricular short axes (RV D , LV D ) and the interventricular septal deviation (ISD) were measured in all PE-positive patients and the echocardiography reports were reviewed. The clinical data assessment included cardio-respiratory and other co-morbidities, systemic anticoagulant therapy (ACT), and the 30-day outcome. Predictors of acute cor pulmonale and the short-term outcome were calculated by univariate and multivariate logistic regressions including odds ratios (OR) and ROC analyses using positive (PPV) and negative predictive values (NPV). Results: 90 patients with acute PE were included (36 with clinically suspected PE, 54 with incidental PE). 26 patients had cardio-respiratory co-morbidities. Four patients underwent systemic thrombolysis, 43 underwent anticoagulation in therapeutic doses, 19 underwent anticoagulation in prophylactic doses, and 24 patients did not undergo ACT. 15 of 41 patients had echocardiographic evidence of acute cor pulmonale. 8 patients died within 30 days. The RV D was the best independent predictor of acute cor pulmonale (p = 0,002, OR = 9.16, PPV = 0.68, NPV=1 at 4.49 cm cut off) and short-term outcome (p= 0,0005, OR = 2.82, PPV = 0.23, NPV = 0.98 at 4.75 cm cut off). The RV D /LV D ratio had a PPV of 0.85 for cor pulmonale. (orig.)

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

    Directory of Open Access Journals (Sweden)

    Vajjalla Ravikumar

    2013-04-01

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

  1. Assessment of myocardial viability using multidetector computed tomography in patients with reperfused acute myocardial infarction

    International Nuclear Information System (INIS)

    Kim, T.; Choi, B.J.; Kang, D.K.; Sun, J.S.

    2012-01-01

    Aim: To assess the prognostic value of 64-section multidetector computed tomography (MDCT) to predict follow-up myocardial dysfunction and functional recovery after reperfusion therapy in patients with acute myocardial infarction (MI) as defined by echocardiography. Materials and methods: After reperfusion therapy for acute MI, 71 patients underwent two-phase contrast-enhanced MDCT and follow-up echocardiography. MDCT findings were compared with echocardiographic findings using kappa statistics. The areas under the receiver operating characteristic curves (AUCs) and the odds ratios (ORs) of early perfusion defects (EPD), delayed enhancement (DE), and residual perfusion defects (RPD) for predicting follow-up myocardial dysfunction and functional recovery were calculated on a segmental basis. Results: The presence of transmural EPD (EPD TM ) or RPD showed good agreement (k = 0.611 and 0.658, respectively) with follow-up myocardial dysfunction, while subendocardial EPD (EPD sub ) or subendocardial DE (DE sub ) showed fair agreement with follow-up myocardial dysfunction (k = 0.235 and 0.234, respectively). The AUC of RPD (0.796) was superior (p TM (0.761) and DE TM (0.771). The presence of EPD TM , DE TM , and RPD were significant, independent positive predictors of follow-up myocardial dysfunction (OR = 6.4, 1.9, and 9.8, respectively). EPD TM was a significant, independent negative predictor of myocardial functional recovery (OR = 0.13). Conclusion: Abnormal myocardial attenuation on two-phase MDCT after reperfusion therapy may provide promising information regarding myocardial viability in patients with acute MI.

  2. Contrast enhancement of cranial lesions in computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Lewander, R; Bergstroem, M; Bergvall, U [Kungliga Karolinska Mediko-Kirurgiska Inst., Stockholm (Sweden)

    1978-01-01

    The time course of enhancement in apparently normal brain tissue, edema and focal lesions during 30 to 60 min after intravenous injection of vascular contrast medium was evaluated in a series of 41 pateints with differnt intracranial lesions. The attenuation of apparently normal unenhanced brain tissue varied with the level of the scan, mainly an effect of beam hardening. Different types of enhancement response are discussed in terms of a 3-compartment model. The differential diagnostic potential of contrast enhancement in the early phase needs further evaluation using instruments with short scanning time, while the late phase of enhancement must be recorded with the use of a reliable head fixation to provide reproducibility of repeat measurements.

  3. Computer-assisted lung nodule volumetry from multi-detector row CT: Influence of image reconstruction parameters

    International Nuclear Information System (INIS)

    Honda, Osamu; Sumikawa, Hiromitsu; Johkoh, Takeshi; Tomiyama, Noriyuki; Mihara, Naoki; Inoue, Atsuo; Tsubamoto, Mitsuko; Natsag, Javzandulam; Hamada, Seiki; Nakamura, Hironobu

    2007-01-01

    Purpose: To investigate differences in volumetric measurement of pulmonary nodules caused by changing the reconstruction parameters for multi-detector row CT. Materials and methods: Thirty-nine pulmonary nodules less than 2 cm in diameter were examined by multi-slice CT. All nodules were solid, and located in the peripheral part of the lungs. The resultant 48 parameters images were reconstructed by changing slice thickness (1.25, 2.5, 3.75, or 5 mm), field of view (FOV: 10, 20, or 30 cm), algorithm (high-spatial frequency algorithm or low-spatial frequency algorithm) and reconstruction interval (reconstruction with 50% overlapping of the reconstructed slices or non-overlapping reconstruction). Volumetric measurements were calculated using commercially available software. The differences between nodule volumes were analyzed by the Kruskal-Wallis test and the Wilcoxon Signed-Ranks test. Results: The diameter of the nodules was 8.7 ± 2.7 mm on average, ranging from 4.3 to 16.4 mm. Pulmonary nodule volume did not change significantly with changes in slice thickness or FOV (p > 0.05), but was significantly larger with the high-spatial frequency algorithm than the low-spatial frequency algorithm (p < 0.05), except for one reconstruction parameter. The volumes determined by non-overlapping reconstruction were significantly larger than those of overlapping reconstruction (p < 0.05), except for a 1.25 mm thickness with 10 cm FOV with the high-spatial frequency algorithm, and 5 mm thickness. The maximum difference in measured volume was 16% on average between the 1.25 mm slice thickness/10 cm FOV/high-spatial frequency algorithm parameters and overlapping reconstruction. Conclusion: Volumetric measurements of pulmonary nodules differ with changes in the reconstruction parameters, with a tendency toward larger volumes in high-spatial frequency algorithm and non-overlapping reconstruction compared to the low-spatial frequency algorithm and overlapping reconstruction

  4. Don't rock the boat: how antiphase crew coordination affects rowing.

    Directory of Open Access Journals (Sweden)

    Anouk J de Brouwer

    Full Text Available It is generally accepted that crew rowing requires perfect synchronization between the movements of the rowers. However, a long-standing and somewhat counterintuitive idea is that out-of-phase crew rowing might have benefits over in-phase (i.e., synchronous rowing. In synchronous rowing, 5 to 6% of the power produced by the rower(s is lost to velocity fluctuations of the shell within each rowing cycle. Theoretically, a possible way for crews to increase average boat velocity is to reduce these fluctuations by rowing in antiphase coordination, a strategy in which rowers perfectly alternate their movements. On the other hand, the framework of coordination dynamics explicates that antiphase coordination is less stable than in-phase coordination, which may impede performance gains. Therefore, we compared antiphase to in-phase crew rowing performance in an ergometer experiment. Nine pairs of rowers performed a two-minute maximum effort in-phase and antiphase trial at 36 strokes min(-1 on two coupled free-floating ergometers that allowed for power losses to velocity fluctuations. Rower and ergometer kinetics and kinematics were measured during the trials. All nine pairs easily acquired antiphase rowing during the warm-up, while one pair's coordination briefly switched to in-phase during the maximum effort trial. Although antiphase interpersonal coordination was indeed less accurate and more variable, power production was not negatively affected. Importantly, in antiphase rowing the decreased power loss to velocity fluctuations resulted in more useful power being transferred to the ergometer flywheels. These results imply that antiphase rowing may indeed improve performance, even without any experience with antiphase technique. Furthermore, it demonstrates that although perfectly synchronous coordination may be the most stable, it is not necessarily equated with the most efficient or optimal performance.

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

    International Nuclear Information System (INIS)

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

    2009-01-01

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

  6. Benchtop phase-contrast X-ray imaging

    Energy Technology Data Exchange (ETDEWEB)

    Gundogdu, O. [Department of Physics, University of Surrey, Guildford, Surrey GU2 7XH (United Kingdom)], E-mail: o.gundogdu@surrey.ac.uk; Nirgianaki, E.; Che Ismail, E.; Jenneson, P.M.; Bradley, D.A. [Department of Physics, University of Surrey, Guildford, Surrey GU2 7XH (United Kingdom)

    2007-12-15

    Clinical radiography has traditionally been based on contrast obtained from absorption when X-rays pass through the body. The contrast obtained from traditional radiography can be rather poor, particularly when it comes to soft tissue. A wide range of media of interest in materials science, biology and medicine exhibit very weak absorption contrast, but they nevertheless produce significant phase shifts with X-rays. The use of phase information for imaging purposes is therefore an attractive prospect. Some of the X-ray phase-contrast imaging methods require highly monochromatic plane wave radiation and sophisticated X-ray optics. However, the propagation-based phase-contrast imaging method adapted in this paper is a relatively simple method to implement, essentially requiring only a microfocal X-ray tube and electronic detection. In this paper, we present imaging results obtained from two different benchtop X-ray sources employing the free space propagation method. X-ray phase-contrast imaging provides higher contrast in many samples, including biological tissues that have negligible absorption contrast.

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

    International Nuclear Information System (INIS)

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

    2010-01-01

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

  8. Comparison of the Multidetector-row Computed Tomographic Angiography Axial and Coronal Planes' Usefulness for Detecting Thoracodorsal Artery Perforators

    Science.gov (United States)

    Kim, Jong Gyu

    2012-01-01

    Background During the planning of a thoracodorsal artery perforator (TDAP) free flap, preoperative multidetector-row computed tomographic (MDCT) angiography is valuable for predicting the locations of perforators. However, CT-based perforator mapping of the thoracodorsal artery is not easy because of its small diameter. Thus, we evaluated 1-mm-thick MDCT images in multiple planes to search for reliable perforators accurately. Methods Between July 2010 and October 2011, 19 consecutive patients (13 males, 6 females) who underwent MDCT prior to TDAP free flap operations were enrolled in this study. Patients ranged in age from 10 to 75 years (mean, 39.3 years). MDCT images were acquired at a thickness of 1 mm in the axial, coronal, and sagittal planes. Results The thoracodorsal artery perforators were detected in all 19 cases. The reliable perforators originating from the descending branch were found in 14 cases, of which 6 had transverse branches. The former were well identified in the coronal view, and the latter in the axial view. The location of the most reliable perforators on MDCT images corresponded well with the surgical findings. Conclusions Though MDCT has been widely used in performing the abdominal perforator free flap for detecting reliable perforating vessels, it is not popular in the TDAP free flap. The results of this study suggest that multiple planes of MDCT may increase the probability of detecting the most reliable perforators, along with decreasing the probability of missing available vessels. PMID:22872839

  9. Improved specimen reconstruction by Hilbert phase contrast tomography.

    Science.gov (United States)

    Barton, Bastian; Joos, Friederike; Schröder, Rasmus R

    2008-11-01

    The low signal-to-noise ratio (SNR) in images of unstained specimens recorded with conventional defocus phase contrast makes it difficult to interpret 3D volumes obtained by electron tomography (ET). The high defocus applied for conventional tilt series generates some phase contrast but leads to an incomplete transfer of object information. For tomography of biological weak-phase objects, optimal image contrast and subsequently an optimized SNR are essential for the reconstruction of details such as macromolecular assemblies at molecular resolution. The problem of low contrast can be partially solved by applying a Hilbert phase plate positioned in the back focal plane (BFP) of the objective lens while recording images in Gaussian focus. Images recorded with the Hilbert phase plate provide optimized positive phase contrast at low spatial frequencies, and the contrast transfer in principle extends to the information limit of the microscope. The antisymmetric Hilbert phase contrast (HPC) can be numerically converted into isotropic contrast, which is equivalent to the contrast obtained by a Zernike phase plate. Thus, in-focus HPC provides optimal structure factor information without limiting effects of the transfer function. In this article, we present the first electron tomograms of biological specimens reconstructed from Hilbert phase plate image series. We outline the technical implementation of the phase plate and demonstrate that the technique is routinely applicable for tomography. A comparison between conventional defocus tomograms and in-focus HPC volumes shows an enhanced SNR and an improved specimen visibility for in-focus Hilbert tomography.

  10. Is contrast-enhanced CT indicated in acute head injury

    International Nuclear Information System (INIS)

    Mauser, H.W.; Nieuwenhuizen, O. van; Veiga-Pires, J.A.

    1984-01-01

    The authors discuss the value of intravenous contrast enhancement in CT scanning in acute head injury. In a series of seventy consecutive patients they conclude that no incremental information was obtained by performing contrast-enhanced CT scans in the acute phase of the head injury. (orig.)

  11. Integrated cardio-thoracic imaging with ECG-Gated 64-slice multidetector-row CT: initial findings in 133 patients

    International Nuclear Information System (INIS)

    Salem, Randa; Remy-Jardin, Martine; Delhaye, Damien; Khalil, Chadi; Teisseire, Antoine; Remy, Jacques; Delannoy-Deken, Valerie; Duhamel, Alain

    2006-01-01

    The purpose of this study was to investigate the possibility of assessing the underlying respiratory disease as well as cardiac function during ECG-gated CT angiography of the chest with 64-slice multidetector-row CT (MDCT). One hundred thirty-three consecutive patients in sinus rhythm with known or suspected ventricular dysfunction underwent an ECG-gated CT angiographic examination of the chest without β-blockers using the following parameters: (1) collimation: 32 x 0.6 mm with z-flying focal spot for the acquisition of 64 overlapping 0.6-mm slices (Sensation 64; Siemens); rotation time: 0.33 s; pitch: 0.3; 120 kV; 200 mAs; ECG-controlled dose modulation (ECG-pulsing) and (2) 120 ml of a 35% contrast agent. Data were reconstructed: (1) to evaluate the underlying respiratory disease (1-mm thick lung and mediastinal scans reconstructed at 55% of the R-R interval; i.e., ''morphologic scans'') and (2) to determine right (RVEF) and left (LVEF) ventricular ejection fractions (short-axis systolic and diastolic images; Argus software; i.e., ''functional scans''). The mean heart rate was 73 bpm (range: 42-120) and the mean scan time was 18.11±2.67 s (range: 10-27). A total of 123 examinations (92%) had both lung and mediastinal images rated as diagnostic scans, whereas 10 examinations (8%) had non-diagnostic images altered by the presence of respiratory-motion artifacts (n=4) or cyclic artifacts related to the use of a pitch value of 0.3 in patients with a very low heart rate during data acquisition (n=6). Assessment of right and left ventricular function was achievable in 124 patients (93%, 95% CI: 88-97%). For these 124 examinations, the mean RVEF was 46.10% (±9.5; range: 20-72) and the mean LVEF was 58.23% (±10.88; range: 20-83). In the remaining nine patients, an imprecise segmentation of the right and left ventricular cavities was considered as a limiting factor for precise calculation of end-systolic and end-diastolic ventricular volumes. The mean (±SD) DLP

  12. Comparison of post contrast CT urography phases in bladder cancer detection

    Energy Technology Data Exchange (ETDEWEB)

    Helenius, Malin; Dahlman, Par; Lonnemark, Maria; Magnusson, Anders [Uppsala University Hospital, Department of Surgical Sciences, Section of Radiology, Uppsala (Sweden); Brekkan, Einar [Uppsala University Hospital, Department of Surgical Sciences, Section of Urology, Uppsala (Sweden); Wernroth, Lisa [Uppsala University Hospital, Uppsala Clinical Research Center, Uppsala (Sweden)

    2016-02-15

    The aim of this study was to investigate which post-contrast phase(s) in a four-phase CT urography protocol is (are) most suitable for bladder cancer detection. The medical records of 106 patients with visible haematuria who underwent a CT urography examination, including unenhanced, enhancement-triggered corticomedullary (CMP), nephrographic (NP) and excretory (EP) phases, were reviewed. The post-contrast phases (n = 318 different phases) were randomized into an evaluation order and blindly reviewed by two uroradiologists. Twenty-one patients were diagnosed with bladder cancer. Sensitivity for bladder cancer detection was 0.95 in CMP, 0.83 in NP and 0.81 in EP. Negative predictive value (NPV) was 0.99 in CMP, 0.96 in NP and 0.95 in EP. The sensitivity was higher in CMP than in both NP (p-value 0.016) and EP (p-value 0.0003). NPV was higher in CMP than in NP (p-value 0.024) and EP (p-value 0.002). In the CT urography protocol with enhancement-triggered scan, sensitivity and NPV were highest in the corticomedullary phase, and this phase should be used for bladder assessment. (orig.)

  13. Comparison of post contrast CT urography phases in bladder cancer detection

    International Nuclear Information System (INIS)

    Helenius, Malin; Dahlman, Par; Lonnemark, Maria; Magnusson, Anders; Brekkan, Einar; Wernroth, Lisa

    2016-01-01

    The aim of this study was to investigate which post-contrast phase(s) in a four-phase CT urography protocol is (are) most suitable for bladder cancer detection. The medical records of 106 patients with visible haematuria who underwent a CT urography examination, including unenhanced, enhancement-triggered corticomedullary (CMP), nephrographic (NP) and excretory (EP) phases, were reviewed. The post-contrast phases (n = 318 different phases) were randomized into an evaluation order and blindly reviewed by two uroradiologists. Twenty-one patients were diagnosed with bladder cancer. Sensitivity for bladder cancer detection was 0.95 in CMP, 0.83 in NP and 0.81 in EP. Negative predictive value (NPV) was 0.99 in CMP, 0.96 in NP and 0.95 in EP. The sensitivity was higher in CMP than in both NP (p-value 0.016) and EP (p-value 0.0003). NPV was higher in CMP than in NP (p-value 0.024) and EP (p-value 0.002). In the CT urography protocol with enhancement-triggered scan, sensitivity and NPV were highest in the corticomedullary phase, and this phase should be used for bladder assessment. (orig.)

  14. Diffractive generalized phase contrast for adaptive phase imaging and optical security

    DEFF Research Database (Denmark)

    Palima, Darwin; Glückstad, Jesper

    2012-01-01

    We analyze the properties of Generalized Phase Contrast (GPC) when the input phase modulation is implemented using diffractive gratings. In GPC applications for patterned illumination, the use of a dynamic diffractive optical element for encoding the GPC input phase allows for onthe- fly optimiza...... security applications and can be used to create phasebased information channels for enhanced information security....

  15. Single-source dual-energy spectral multidetector CT of pancreatic adenocarcinoma: optimization of energy level viewing significantly increases lesion contrast.

    Science.gov (United States)

    Patel, B N; Thomas, J V; Lockhart, M E; Berland, L L; Morgan, D E

    2013-02-01

    To evaluate lesion contrast in pancreatic adenocarcinoma patients using spectral multidetector computed tomography (MDCT) analysis. The present institutional review board-approved, Health Insurance Portability and Accountability Act of 1996 (HIPAA)-compliant retrospective study evaluated 64 consecutive adults with pancreatic adenocarcinoma examined using a standardized, multiphasic protocol on a single-source, dual-energy MDCT system. Pancreatic phase images (35 s) were acquired in dual-energy mode; unenhanced and portal venous phases used standard MDCT. Lesion contrast was evaluated on an independent workstation using dual-energy analysis software, comparing tumour to non-tumoural pancreas attenuation (HU) differences and tumour diameter at three energy levels: 70 keV; individual subject-optimized viewing energy level (based on the maximum contrast-to-noise ratio, CNR); and 45 keV. The image noise was measured for the same three energies. Differences in lesion contrast, diameter, and noise between the different energy levels were analysed using analysis of variance (ANOVA). Quantitative differences in contrast gain between 70 keV and CNR-optimized viewing energies, and between CNR-optimized and 45 keV were compared using the paired t-test. Thirty-four women and 30 men (mean age 68 years) had a mean tumour diameter of 3.6 cm. The median optimized energy level was 50 keV (range 40-77). The mean ± SD lesion contrast values (non-tumoural pancreas - tumour attenuation) were: 57 ± 29, 115 ± 70, and 146 ± 74 HU (p = 0.0005); the lengths of the tumours were: 3.6, 3.3, and 3.1 cm, respectively (p = 0.026); and the contrast to noise ratios were: 24 ± 7, 39 ± 12, and 59 ± 17 (p = 0.0005) for 70 keV, the optimized energy level, and 45 keV, respectively. For individuals, the mean ± SD contrast gain from 70 keV to the optimized energy level was 59 ± 45 HU; and the mean ± SD contrast gain from the optimized energy level to 45 keV was 31 ± 25 HU (p = 0

  16. Evaluation of peripheral artery stent with 64-slice multi-detector row CT angiography: Prospective comparison with digital subtraction angiography

    International Nuclear Information System (INIS)

    Li Xiaoming; Li Yuhua; Tian Jianming; Xiao Yi; Lu Jianping; Jing Zaiping; Sheng Jing; Edwin, Angela; Wu Fanghong

    2010-01-01

    Purpose: To assess the accuracy of 64-slice multi-detector row computed tomography (MDCT) angiography in the evaluation of peripheral artery in-stent or peristent restenosis, with conventional digital subtraction angiography (DSA) as the reference standard. Materials and methods: Forty-one patients (30 men, 11 women; mean age, 69.8 ± 9.2 years) with symptomatic peripheral arterial occlusive disease after peripheral artery stenting (81 stented lesions) underwent both conventional DSA and 64-slice MDCT angiography. Each stent was classified as evaluable or unevaluable, and every stent was divided into three segments (proximal stent, stent body, and distal stent), resulting in 243 segments. For evaluation, stenosis was graded as follows: 1, none or slight stenosis (<25%); 2, mild stenosis (25-49%); 3, moderate stenosis (50-74%); 4, severe stenosis or total occlusion (≥75%). Two readers evaluated all CT angiograms with regard to narrowing of in-stent or peristent restenosis by consensus. Results were compared with findings of the DSA. Results: Of 81 stents, 62 (76.5%) were determined to be assessable. The metal artifact of the gold marker and motion artifact increased uninterpretability of the images of stents. Overall, 24 of 28 in-stent restenosis and 38 of 53 persistent restenosis were correctly detected by MDCT (85.7% and 71.7% sensitivity). In evaluable stents, 21 of 22 in-stent restenoses and 27 of 28 persistent restenosis were correctly detected (95.4% and 96.4% sensitivity). Additionally, as the grade of stenosis increases, the mean level of CT values in the stent lumina decreases linearly accordingly. Conclusion: 64-Slice MDCT has a high accuracy for the detection of significant in-stent or peristent restenosis of assessable stents in patients with peripheral artery stent implantation and therefore can be considered as a valuable noninvasive technique for stent surveillance.

  17. Accuracy of multidetector row computed tomography for the diagnosis of acute bowel ischemia in a non-selected study population

    International Nuclear Information System (INIS)

    Wiesner, Walter; Hauser, Andreas; Steinbrich, Wolfgang

    2004-01-01

    The diagnostic accuracy of multidetector row computed tomography for the prospective diagnosis of acute bowel ischemia in the daily clinical routine was analyzed. Two hundred ninety-one consecutive patients with an acute or subacute abdomen, examined by MDCT over a time period of 5 months, were included in the study. All original CT diagnoses made during the daily routine by radiological generalists were compared to the final diagnoses made by using all available medical information from endoscopies, surgical interventions, autopsies and follow-up. Finally, all CT examinations of patients with an initial CT diagnosis or a final diagnosis of bowel ischemia were reread by a radiologist specialized in abdominal imaging in order to analyze the CT findings and the reasons for initially false negative or false positive CT readings. Twenty-four patients out of 291 (8.2%) had acute bowel ischemia. The age of affected patients ranged from 50 to 94 years (mean age: 75.7 years). Eleven patients were male, and 13 female. Reasons for acute bowel ischemia were: arterio-occlusive (n=11), non-occlusive (n=5), strangulation (n=2), over-distension (n=3) and radiation (n=3). The prospective sensitivity, specificity, PPV and NPV of MDCT for the diagnosis of acute bowel ischemia in the daily routine were 79.17, 98.51, 90.48 and 98.15%. MDCT reaches a similarly high sensitivity in diagnosing acute bowel as angiography. Furthermore, it has the advantage of being helpful in most of its clinical differential diagnoses and of being less invasive with the consecutive possibility of being used earlier in the diagnostic process with all the resulting positive effects on the patients prognosis. Therefore, nowadays MDCT should probably be used as the first step imaging modality of choice in patients with suspected acute bowel ischemia. (orig.)

  18. Accuracy of intermediate dose of furosemide injection to improve multidetector row CT urography

    International Nuclear Information System (INIS)

    Roy, Catherine; Jeantroux, Jeremy; Irani, Farah G.; Sauer, Benoit; Lang, Herve; Saussine, Christian

    2008-01-01

    Objective: Evaluate the usefulness of intermediate dose furosemide to improve visualization of the intrarenal collecting system and ureter using MDCTU. Materials and methods: Two groups of 100 patients without urinary tract disease or major abdominal pathology underwent MDCTU. Group I (various abdominal indications) was performed without any additional preparation and Group II (suspicion of urinary tract disease) 10 min after injection of furosemide (20 mg). MIP images of the excretory phase were post-processed. Maximal short-axis diameter of the pelvis and ureter were measured on axial images for all phases. Visualization of the collecting system wall and the identification of the whole ureter were assessed. Results: Mean pelvic diameter before contrast was (7.4 mm, S.D. ± 2.7; 13.4 mm, S.D. ± 4.1), on cortico-medullary phase (8.4 mm, S.D. ± 4.2; 14.3 mm, S.D. ± 4), on nephrographic phase (8.1 mm, S.D. ± 2.5; 14.8 mm, S.D. ± 4) and on excretory phase (9.7 mm, S.D. ± 3.4; 14.9 mm, S.D. ± 4.5), respectively, for Groups I and II. Intrarenal collecting system wall was clearly identified on both corticomedullary and nephrographic phases in 91% of Group II against 20% of Group I. Opacification of the entire ureter was excellent on excretory phase in 96% of Group II against 13% of Group I. The difference between the mean values for the two groups was statistically significant for all phases (p -9 ). Conclusion: Intermediate-dose furosemide (20 mg) before MDCTU is a very simple add-on for accurate depiction of pelvicalyceal details and collecting system wall without artefacts. The procedure is associated with a constant and complete visualisation of the entire urete

  19. Accuracy of intermediate dose of furosemide injection to improve multidetector row CT urography

    Energy Technology Data Exchange (ETDEWEB)

    Roy, Catherine [Department of Radiology B, Universitary Hospital of Strasbourg-Civil Hospital, 1, Place de l' hopital BP 426, 67091 Strasbourg Cedex (France)], E-mail: catherine.roy@chru-strasbourg.fr; Jeantroux, Jeremy; Irani, Farah G.; Sauer, Benoit [Department of Radiology B, Universitary Hospital of Strasbourg-Civil Hospital, 1, Place de l' hopital BP 426, 67091 Strasbourg Cedex (France); Lang, Herve; Saussine, Christian [Department of Urology, Universitary Hospital of Strasbourg-Civil Hospital, 1, Place de l' hopital BP 426, 67091 Strasbourg Cedex (France)

    2008-05-15

    Objective: Evaluate the usefulness of intermediate dose furosemide to improve visualization of the intrarenal collecting system and ureter using MDCTU. Materials and methods: Two groups of 100 patients without urinary tract disease or major abdominal pathology underwent MDCTU. Group I (various abdominal indications) was performed without any additional preparation and Group II (suspicion of urinary tract disease) 10 min after injection of furosemide (20 mg). MIP images of the excretory phase were post-processed. Maximal short-axis diameter of the pelvis and ureter were measured on axial images for all phases. Visualization of the collecting system wall and the identification of the whole ureter were assessed. Results: Mean pelvic diameter before contrast was (7.4 mm, S.D. {+-} 2.7; 13.4 mm, S.D. {+-} 4.1), on cortico-medullary phase (8.4 mm, S.D. {+-} 4.2; 14.3 mm, S.D. {+-} 4), on nephrographic phase (8.1 mm, S.D. {+-} 2.5; 14.8 mm, S.D. {+-} 4) and on excretory phase (9.7 mm, S.D. {+-} 3.4; 14.9 mm, S.D. {+-} 4.5), respectively, for Groups I and II. Intrarenal collecting system wall was clearly identified on both corticomedullary and nephrographic phases in 91% of Group II against 20% of Group I. Opacification of the entire ureter was excellent on excretory phase in 96% of Group II against 13% of Group I. The difference between the mean values for the two groups was statistically significant for all phases (p < 10{sup -9}). Conclusion: Intermediate-dose furosemide (20 mg) before MDCTU is a very simple add-on for accurate depiction of pelvicalyceal details and collecting system wall without artefacts. The procedure is associated with a constant and complete visualisation of the entire urete.

  20. Noninvasive imaging of coronary arteries: current and future role of multidetector row computer tomography

    International Nuclear Information System (INIS)

    Nedevska, M.; Stoinova, V.

    2006-01-01

    Full text: This review will present the current and future role of cardiac computer tomography (CCT), and particular multidetector CCT, for imaging of atherosclerotic pathologic changes of the coronary arteries. Atherosclerosis and its cardio-vascular complications represent one of the major issues of public health in industrial countries. Different imaging modalities, including invasive coronarography, have been aimed to the diagnosis of the disease, when it provokes symptomatic decrease of the blood flow. In spite of development of surgical and percutaneous methods for coronary revascularization, coronary artery disease remains the major cause of death in North America and Europe. This demonstrates the need of novel, complementary diagnostic strategies, aimed to identify asymptomatic stages as the basis of pharmacological interventions. Noninvasive coronary angiography with multidetector CT allows both assessment of luminal stenosis and subclinical disease of arterial wall. Large trails are missing now to understand and present what will be the role of this technology in the comprehensive assessment of patients, suspected of having CAD. Based on experience and current potentials we will describe how tomographic coronary imaging may eventually supplement traditional angiographic techniques in understanding the patterns of atherosclerotic CAD development

  1. Fluid-elastic vibration in two-phase cross flow

    International Nuclear Information System (INIS)

    Sasakawa, T.; Serizawa, A.; Kawara, Z.

    2003-01-01

    The present work aims at clarifying the mechanisms of fluid elastic vibration of tube bundles in two-phase cross flow. The experiment is conducted using air-water two-phase flow under atmospheric pressure. The test section is a 1.03m long transparent acrylic square duct with 128 x 128 mm 2 cross section, which consists of 3 rod-rows with 5 rods in each row. The rods are 125mm long aluminum rods with 22 mm in diameter (p/D=1.45). The natural frequency of rod vibration is about 30Hz. The result indicated a diversion of observed trend in vibration behavior depending on two-phase flow patterns either bubbly flow or churn flow. Specifically, in churn flow, the fluid elastic vibration has been observed to occur when the frequency in void fraction fluctuation approached to the natural frequency of the rods, but this was not the case in fluid elastic vibration in bubbly flow. This fact suggests the existence of mechanisms closely coupled with two-phase flow structures depending on the flow patterns, that is, static two-phase character-controlled mechanism in bubbly flow and dynamic character- controlled in churn flow

  2. Generalized Phase Contrast

    CERN Document Server

    Glückstad, Jesper

    2009-01-01

    Generalized Phase Contrast elevates the phase contrast technique not only to improve phase imaging but also to cross over and interface with diverse and seemingly disparate fields of contemporary optics and photonics. This book presents a comprehensive introduction to the Generalized Phase Contrast (GPC) method including an overview of the range of current and potential applications of GPC in wavefront sensing and phase imaging, structured laser illumination and image projection, optical trapping and manipulation, and optical encryption and decryption. The GPC method goes further than the restrictive assumptions of conventional Zernike phase contrast analysis and achieves an expanded range of validity beyond weak phase perturbations. The generalized analysis yields design criteria for tuning experimental parameters to achieve optimal performance in terms of accuracy, fidelity and light efficiency. Optimization can address practical issues, such as finding an optimal spatial filter for the chosen application, ...

  3. Contrast-to-noise ratio optimization for a prototype phase-contrast computed tomography scanner

    International Nuclear Information System (INIS)

    Müller, Mark; Yaroshenko, Andre; Velroyen, Astrid; Tapfer, Arne; Bech, Martin; Pauwels, Bart; Bruyndonckx, Peter; Sasov, Alexander; Pfeiffer, Franz

    2015-01-01

    In the field of biomedical X-ray imaging, novel techniques, such as phase-contrast and dark-field imaging, have the potential to enhance the contrast and provide complementary structural information about a specimen. In this paper, a first prototype of a preclinical X-ray phase-contrast CT scanner based on a Talbot-Lau interferometer is characterized. We present a study of the contrast-to-noise ratios for attenuation and phase-contrast images acquired with the prototype scanner. The shown results are based on a series of projection images and tomographic data sets of a plastic phantom in phase and attenuation-contrast recorded with varying acquisition settings. Subsequently, the signal and noise distribution of different regions in the phantom were determined. We present a novel method for estimation of contrast-to-noise ratios for projection images based on the cylindrical geometry of the phantom. Analytical functions, representing the expected signal in phase and attenuation-contrast for a circular object, are fitted to individual line profiles of the projection data. The free parameter of the fit function is used to estimate the contrast and the goodness of the fit is determined to assess the noise in the respective signal. The results depict the dependence of the contrast-to-noise ratios on the applied source voltages, the number of steps of the phase stepping routine, and the exposure times for an individual step. Moreover, the influence of the number of projection angles on the image quality of CT slices is investigated. Finally, the implications for future imaging purposes with the scanner are discussed

  4. Phantom-Calibrated versus Automatic Coronary Artery Mass Quantification with Multidetector-Row Computed Tomography: In Vitro and In Vivo Study

    International Nuclear Information System (INIS)

    Serafin, Z.; Lasek, W.; Laskowska, K.

    2008-01-01

    Background: Coronary artery calcium scoring is used as a method for cardiovascular risk stratification and monitoring of coronary heart disease. Automatic software-based calcium mass calculation has been proposed to improve the performance of the procedure. Purpose: To compare two algorithms of calcium mass measurement, automatic and phantom calibrated, with respect to correlation, measurement error, and accuracy in vitro and in vivo. Material and Methods: A cardiac phantom with calcium cylinder inserts was scanned with sequential non-overlapping collimation 4x2.5 mm, at 120 kV and 165 mAs. Fifty adults (37 men; mean age 46.2 years) were examined with the same settings using prospective electrocardiographic triggering to detect and quantify coronary artery calcifications. Calculations were performed with two methods: software-based automatic calcium mass measurement (ACM) and phantom-calibrated calcium mass measurement (CCM). Results: The total phantom calcium masses measured with ACM and CCM were 175.0±13.8 mg and 163.0±4.4 mg, respectively (P<0.0001), and ACM produced a higher mean error (4.5 vs. 3.2; P<0.05). Results of ACM and CCM were strongly correlated to each other (R=0.73-0.96; P<0.0001). Mean image noise in the patient study was 8.72±1.68 HU. Results of patient calcium scoring with ACM and CCM were significantly different (median 70.3 mg and 59.7 mg, respectively; P<0.0001), with a mean systematic error of 17.5% (limit of agreement between 14.6% and 20.4%). The use of ACM resulted in an altered quartile classification for 14% of patients, as compared to CCM; all of these patients were classified into a higher category. Conclusion: Our data indicate that multidetector-row computed tomography coronary calcium mass determination based on dedicated phantom calibration shows lower measurement error than an automatic software-based calculation method. The tested automatic software does not yet seem to be a reliable option for calcium mass measurement

  5. Phantom-Calibrated versus Automatic Coronary Artery Mass Quantification with Multidetector-Row Computed Tomography: In Vitro and In Vivo Study

    Energy Technology Data Exchange (ETDEWEB)

    Serafin, Z.; Lasek, W.; Laskowska, K. (Dept. of Radiology and Diagnostic Imaging, Nicolaus Copernicus Univ., Collegium Medicum, Bydgoszcz (Poland))

    2008-11-15

    Background: Coronary artery calcium scoring is used as a method for cardiovascular risk stratification and monitoring of coronary heart disease. Automatic software-based calcium mass calculation has been proposed to improve the performance of the procedure. Purpose: To compare two algorithms of calcium mass measurement, automatic and phantom calibrated, with respect to correlation, measurement error, and accuracy in vitro and in vivo. Material and Methods: A cardiac phantom with calcium cylinder inserts was scanned with sequential non-overlapping collimation 4x2.5 mm, at 120 kV and 165 mAs. Fifty adults (37 men; mean age 46.2 years) were examined with the same settings using prospective electrocardiographic triggering to detect and quantify coronary artery calcifications. Calculations were performed with two methods: software-based automatic calcium mass measurement (ACM) and phantom-calibrated calcium mass measurement (CCM). Results: The total phantom calcium masses measured with ACM and CCM were 175.0+-13.8 mg and 163.0+-4.4 mg, respectively (P<0.0001), and ACM produced a higher mean error (4.5 vs. 3.2; P<0.05). Results of ACM and CCM were strongly correlated to each other (R=0.73-0.96; P<0.0001). Mean image noise in the patient study was 8.72+-1.68 HU. Results of patient calcium scoring with ACM and CCM were significantly different (median 70.3 mg and 59.7 mg, respectively; P<0.0001), with a mean systematic error of 17.5% (limit of agreement between 14.6% and 20.4%). The use of ACM resulted in an altered quartile classification for 14% of patients, as compared to CCM; all of these patients were classified into a higher category. Conclusion: Our data indicate that multidetector-row computed tomography coronary calcium mass determination based on dedicated phantom calibration shows lower measurement error than an automatic software-based calculation method. The tested automatic software does not yet seem to be a reliable option for calcium mass measurement

  6. Multidetector computed tomography for the assessment of adnexal Mass: Is unenhenced CT scan necessary?

    International Nuclear Information System (INIS)

    Jung, Sung Il; Park, Hee Sun; Kim, Young Jun; Jeon, Hae Jeong

    2014-01-01

    To compare the diagnostic performance and radiation dose between contrast-enhanced CT (ECT) alone, and combined unenhanced and contrast-enhanced CT (UE + ECT) for the assessment of adnexal mass. This retrospective study was approved by the Institutional Review Board. A total of 146 consecutive patients (mean age, 41.1 years) who underwent preoperative unenhanced and contrast-enhanced multidetector CT of the pelvis and had adnexal masses found at surgery were included. Two readers independently evaluated the likelihood of adnexal malignancy on a 5-point scale on two different imaging datasets (ECT alone and UE + ECT). The area under the receiver operating characteristic curve (AUC) was used to evaluate diagnostic performance. Radiation dose to patients was calculated by the volume CT dose index (CTDIvol) and the dose length products (DLP) on each dataset. Of the total 178 adnexal masses, 133 masses were benign and 45 masses were malignant. For both readers, there is no significant difference of AUC values between ECT alone and UE + ECT for the detection of adnexal malignancy (reader 1, 0.93 vs. 0.95; reader 2, 0.92 vs. 0.91) (p > 0.05). The mean CTDIvol (12.6 ± 2.2 mGy) and DLP (641.2 ± 137.2 mGy) of ECT alone was significantly lower than the mean CTDIvol (21.5 ± 2.7 mGy) and DLP (923.6 ± 158.8 mGy) of UE + ECT (p < 0.0001). The use of unenhanced CT scan in addition to contrast-enhanced CT scan does not improve the detection of adnexal malignancy, but increases radiation exposure.

  7. Whole tumour first-pass perfusion using a low-dose method with 64-section multidetector row computed tomography in oesophageal squamous cell carcinoma

    International Nuclear Information System (INIS)

    Chen Tianwu; Yang Zhigang; Dong Zhihui; Li Yuan; Yao Jin; Wang Qiling; Qian Lingling

    2011-01-01

    Purpose: To propose a low-dose method at tube current-time product of 50 mAs for whole tumour first-pass perfusion of oesophageal squamous cell carcinoma using 64-section multidetector row computed tomography (MDCT), and to assess the original image quality and accuracy of perfusion parameters. Materials and methods: Fifty-nine consecutive patients with confirmed oesophageal squamous cell carcinomas were enrolled into our study, and underwent whole tumour first-pass perfusion scan with 64-section MDCT at 50 mAs. Image data were statistically reviewed focusing on original image quality demonstrated by image-quality scores and signal-to-noise (S/N) ratios; and perfusion parameters including perfusion (PF, in ml/min/ml), peak enhanced density (PED, in HU), time to peak (TTP, in seconds) and blood volume (BV, in ml/100 g) for the tumour. To test the interobserver agreement of perfusion measurements, perfusion analyses were repeatedly performed. Results: Original image-quality scores were 4.71 ± 0.49 whereas S/N ratios were 5.21 ± 2.05, and the scores were correlated with the S/N ratios (r = 0.465, p < 0.0001). Mean values for PF, PED, TTP and BV of the tumour were 33.27 ± 24.15 ml/min/ml, 24.06 ± 9.87 HU, 29.42 ± 8.61 s, and 12.45 ± 12.22 ml/100 g, respectively. Intraclass correlation coefficient between the replicated measurements of each perfusion parameter was greater than 0.99, and mean difference of the replicated measurements of each parameter was close to zero. Conclusion: Whole tumour first-pass perfusion with 64-section MDCT at low-dose radiation could be reproducible to assess microcirculation in oesophageal squamous cell carcinoma without compromising subjective original image quality of the tumour.

  8. Multidetector computerized tomography enema versus magnetic resonance enema in the diagnosis of rectosigmoid endometriosis

    Energy Technology Data Exchange (ETDEWEB)

    Biscaldi, Ennio, E-mail: ennio.biscaldi@gmail.com [Department of Radiology, Galliera Hospital, via Mura delle Capuccine 14, 16128 Genoa (Italy); Ferrero, Simone, E-mail: simone.ferrero@unige.it [Department of Obstetrics and Gynecology, San Martino Hospital and National Institute for Cancer Research, University of Genoa, Largo Rosanna Benzi, 1, 16132 Genoa (Italy); Leone Roberti Maggiore, Umberto, E-mail: ulrm@libero.it [Department of Obstetrics and Gynecology, San Martino Hospital and National Institute for Cancer Research, University of Genoa, Largo Rosanna Benzi, 1, 16132 Genoa (Italy); Remorgida, Valentino, E-mail: vremorgida@yahoo.it [Department of Obstetrics and Gynecology, San Martino Hospital and National Institute for Cancer Research, University of Genoa, Largo Rosanna Benzi, 1, 16132 Genoa (Italy); Venturini, Pier Luigi, E-mail: venturini@unige.it [Department of Obstetrics and Gynecology, San Martino Hospital and National Institute for Cancer Research, University of Genoa, Largo Rosanna Benzi, 1, 16132 Genoa (Italy); Rollandi, Gian Andrea, E-mail: rollandi@galliera.it [Department of Radiology, Galliera Hospital, via Mura delle Capuccine 14, 16128 Genoa (Italy)

    2014-02-15

    Purpose: To compare the accuracy of multidetector computerized tomography enema (MDCT-e) and magnetic resonance enema (MRI-e) in determining the presence of sigmoid and rectal endometriotic nodules. Materials and methods: 260 women (32.6 ± 4.3 years) with symptoms suggestive of rectosigmoid endometriosis underwent MDCT-e and MRI-e prior to laparoscopy. After retrograde colonic distention and injection of intravenous contrast medium, patients were scanned on a 64-row MDCT scanner. MRI-e was performed on a 1.5 T magnet using an 8 channels phased array coil; intestinal distention was achieved by introducing in the rectum 250–300 ml of ultrasonographic gel diluted with saline solution. Radiological findings were compared with surgical and histological results. Results: 176 women had rectosigmoid endometriosis at surgery. There was no significant difference in the accuracy of MDCT-e (98.5%) and MRI-e (96.9%) in the diagnosis of sigmoid and rectal endometriosis (p = 0.248). The sensitivity, specificity, positive predictive value, negative predictive value, positive likelihood ratio and negative likelihood ratio of MDCT-e and MRI-e were respectively 98.3%, 98.8%, 99.4%, 96.5%, 81.59, 0.02 and 97.2%, 96.4%, 98.3%, 94.1%, 26.89, 0.03. Conclusions: Both MDCT-e and MRI-e are accurate in the diagnosis of rectal and sigmoid endometriosis.

  9. Multidetector computerized tomography enema versus magnetic resonance enema in the diagnosis of rectosigmoid endometriosis

    International Nuclear Information System (INIS)

    Biscaldi, Ennio; Ferrero, Simone; Leone Roberti Maggiore, Umberto; Remorgida, Valentino; Venturini, Pier Luigi; Rollandi, Gian Andrea

    2014-01-01

    Purpose: To compare the accuracy of multidetector computerized tomography enema (MDCT-e) and magnetic resonance enema (MRI-e) in determining the presence of sigmoid and rectal endometriotic nodules. Materials and methods: 260 women (32.6 ± 4.3 years) with symptoms suggestive of rectosigmoid endometriosis underwent MDCT-e and MRI-e prior to laparoscopy. After retrograde colonic distention and injection of intravenous contrast medium, patients were scanned on a 64-row MDCT scanner. MRI-e was performed on a 1.5 T magnet using an 8 channels phased array coil; intestinal distention was achieved by introducing in the rectum 250–300 ml of ultrasonographic gel diluted with saline solution. Radiological findings were compared with surgical and histological results. Results: 176 women had rectosigmoid endometriosis at surgery. There was no significant difference in the accuracy of MDCT-e (98.5%) and MRI-e (96.9%) in the diagnosis of sigmoid and rectal endometriosis (p = 0.248). The sensitivity, specificity, positive predictive value, negative predictive value, positive likelihood ratio and negative likelihood ratio of MDCT-e and MRI-e were respectively 98.3%, 98.8%, 99.4%, 96.5%, 81.59, 0.02 and 97.2%, 96.4%, 98.3%, 94.1%, 26.89, 0.03. Conclusions: Both MDCT-e and MRI-e are accurate in the diagnosis of rectal and sigmoid endometriosis

  10. Phase- and size-adjusted CT cut-off for differentiating neoplastic lesions from normal colon in contrast-enhanced CT colonography

    International Nuclear Information System (INIS)

    Luboldt, W.; Kroll, M.; Wetter, A.; Vogl, T.J.; Toussaint, T.L.; Hoepffner, N.; Holzer, K.; Kluge, A.

    2004-01-01

    A computed tomography (CT) cut-off for differentiating neoplastic lesions (polyps/carcinoma) from normal colon in contrast-enhanced CT colonography (CTC) relating to the contrast phase and lesion size is determined. CT values of 64 colonic lesions (27 polyps 0 . The slope m was determined by linear regression in the correlation (lesion ∝[xA + (1 - x)V]//H) and the Y-intercept y 0 by the minimal shift of the line needed to maximize the accuracy of separating the colonic wall from the lesions. The CT value of the lesions correlated best with the intermediate phase: 0.4A+ 0.6V(r=0.8 for polyps ≥10 mm, r=0.6 for carcinomas, r=0.4 for polyps <10 mm). The accuracy in the differentiation between lesions and normal colonic wall increased with the height implemented as divisor, reached 91% and was obtained by the dynamic cut-off described by the formula: cut-off(A,V,H) = 1.1[0.4A + 0.6V]/H + 69.8. The CT value of colonic polyps or carcinomas can be increased extrinsically by scanning in the phase in which 0.4A + 0.6V reaches its maximum. Differentiating lesions from normal colon based on CT values is possible in contrast-enhanced CTC and improves when the cut-off is adjusted (normalized) to the contrast phase and lesion size. (orig.)

  11. Multidetector-row computed tomography for evaluating the branching angle of the celiac artery: a descriptive study

    International Nuclear Information System (INIS)

    Tokue, Hiroyuki; Tokue, Azusa; Tsushima, Yoshito

    2012-01-01

    We performed this study in order to investigate the shape of the origin of the celiac artery in maximum intensity projection (MIP) using routine 64 multidetector-row computed tomography (MDCT) data in order to plan for the implantation of an intra-arterial hepatic port system. A total of 1,104 patients with hepatocellular carcinoma were assessed with MDCT. In the definition of the branching angle, the anterior side of the abdominal aorta was considered the baseline, and the cranial and caudal sides were designated as 0 and 180 degrees, respectively. The angles between 0 and 90 degrees and between 90 and 180 degrees from the cranial side were considered upward and downward, respectively, and the branching angle of the celiac artery was classified every 30 degrees. The subclavian arterial route was used for the implantation of an intra-arterial hepatic port system in patients with branching angles of 150 degrees or more (sharp downward). The median branching angle was (median ± standard deviation) 135 ± 23 (range, 51–174) degrees. The branching was upward in 77 patients (7%) and downward in 1,027 patients (93%). The branching was downward with an angle of 120 to150 degrees in most patients (n = 613). The branching was sharply downward with an angle of 150 degrees or more in 177 patients (16%). A total of 10 patients were referred for interventional placement of an intra-arterial hepatic port system. The subclavian arterial route was used for implantation of an intra-arterial hepatic port system in 2 patients with sharp downward branching. The branching angle of the celiac artery can be easily determined by the preparation of MIP images from routine MDCT data. MIP may provide useful information for the selection of the catheter insertion route in order to avoid a sharp branching angle of the celiac artery

  12. Phase contrast STEM for thin samples: Integrated differential phase contrast.

    Science.gov (United States)

    Lazić, Ivan; Bosch, Eric G T; Lazar, Sorin

    2016-01-01

    It has been known since the 1970s that the movement of the center of mass (COM) of a convergent beam electron diffraction (CBED) pattern is linearly related to the (projected) electrical field in the sample. We re-derive a contrast transfer function (CTF) for a scanning transmission electron microscopy (STEM) imaging technique based on this movement from the point of view of image formation and continue by performing a two-dimensional integration on the two images based on the two components of the COM movement. The resulting integrated COM (iCOM) STEM technique yields a scalar image that is linear in the phase shift caused by the sample and therefore also in the local (projected) electrostatic potential field of a thin sample. We confirm that the differential phase contrast (DPC) STEM technique using a segmented detector with 4 quadrants (4Q) yields a good approximation for the COM movement. Performing a two-dimensional integration, just as for the COM, we obtain an integrated DPC (iDPC) image which is approximately linear in the phase of the sample. Beside deriving the CTFs of iCOM and iDPC, we clearly point out the objects of the two corresponding imaging techniques, and highlight the differences to objects corresponding to COM-, DPC-, and (HA) ADF-STEM. The theory is validated with simulations and we present first experimental results of the iDPC-STEM technique showing its capability for imaging both light and heavy elements with atomic resolution and a good signal to noise ratio (SNR). Copyright © 2015 Elsevier B.V. All rights reserved.

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

    International Nuclear Information System (INIS)

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

    2008-01-01

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

  14. Normal mediastinal and hilar lymph nodes in children on multi-detector row chest computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Jong, Pim A. de; Nievelstein, Rutger-Jan A. [University Medical Center Utrecht and Wilhelmina Children' s Hospital, Department of Radiology, Utrecht (Netherlands)

    2012-02-15

    To study normal mediastinal and hilar lymph nodes on multi-detector chest computed tomography (CT). A cohort of 120 children aged 1-17 years underwent emergency CT, including the chest, after high-energy trauma. Axial 5-mm reconstructions were evaluated for lymph nodes at hilar and various mediastinal levels and the short-axis diameters were measured. At least one lymph node was found in 115 (96%) children, with subcarinal (69%), lower paratracheal (64%) and hilar (60%) nodes being most common. Up to 10 years of age most lymph nodes were smaller than or equal to 7 mm. In older children lymph nodes measuring up to 10-mm-short-axis diameter were found. Lymph nodes were rare along the mammary vessels, at lower oesophageal and at prevascular and posterior mediastinal levels in children. Mediastinal and hilar lymph nodes are more common than previously thought, probably because of increased detection by modern multi-detector CT. Lymph node location and age have to be taken into account when evaluating lymph nodes in the paediatric chest. (orig.)

  15. Normal mediastinal and hilar lymph nodes in children on multi-detector row chest computed tomography

    International Nuclear Information System (INIS)

    Jong, Pim A. de; Nievelstein, Rutger-Jan A.

    2012-01-01

    To study normal mediastinal and hilar lymph nodes on multi-detector chest computed tomography (CT). A cohort of 120 children aged 1-17 years underwent emergency CT, including the chest, after high-energy trauma. Axial 5-mm reconstructions were evaluated for lymph nodes at hilar and various mediastinal levels and the short-axis diameters were measured. At least one lymph node was found in 115 (96%) children, with subcarinal (69%), lower paratracheal (64%) and hilar (60%) nodes being most common. Up to 10 years of age most lymph nodes were smaller than or equal to 7 mm. In older children lymph nodes measuring up to 10-mm-short-axis diameter were found. Lymph nodes were rare along the mammary vessels, at lower oesophageal and at prevascular and posterior mediastinal levels in children. Mediastinal and hilar lymph nodes are more common than previously thought, probably because of increased detection by modern multi-detector CT. Lymph node location and age have to be taken into account when evaluating lymph nodes in the paediatric chest. (orig.)

  16. Peliosis Hepatis with Hemorrhagic Necrosis and Rupture: a Case Report with Emphasis on the Multi-Detector CT Findings

    OpenAIRE

    Kim, Eun-A; Yoon, Kwon-Ha; Jeon, Se-Jung; Cai, Quan-Yu; Lee, Young-Whan; Yoon, Seong Eon; Yoon, Ki-Jung; Juhng, Seon-Kwan

    2007-01-01

    We report here on an uncommon case of peliosis hepatis with hemorrhagic necrosis that was complicated by massive intrahepatic bleeding and rupture, and treated by emergent right lobectomy. We demonstrate the imaging findings, with emphasis on the triphasic, contrast-enhanced multidetector CT findings, as well as reporting the clinical outcome in a case of peliosis hepatis with fatal hemorrhage.

  17. 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; (dogs. Short-term and diffuse heterogeneity of the spleen in the early venous phase was determined to be a normal finding. © 2016 American College of Veterinary Radiology.

  18. Ectopic origin of bronchial arteries: assessment with multidetector helical CT angiography

    International Nuclear Information System (INIS)

    Hartmann, Ieneke J.C.; Remy-Jardin, Martine; Menchini, Laura; Teisseire, Antoine; Khalil, Chadi; Remy, Jacques

    2007-01-01

    The purpose of this study was to determine non-invasively the frequency of ectopic bronchial arteries (BA) (i.e., bronchial arteries originating at a level of the descending aorta other than T5-T6 or from any aortic collateral vessel) on multidetector-row CT angiograms (CTA) obtained in patients with hemoptysis. Over a 5-year period (2000-2005), 251 consecutive patients with hemoptysis underwent multidetector-row CT angiography of the thorax. From this population, 37 patients were excluded because of a suboptimal CTA examination (n = 19), the presence of extensive mediastinal disease (n = 15) or severe chest deformation (n = 3) precluding any precise analysis of the bronchial arteries at CTA. Our final study group included 214 patients who underwent a thin-collimated CT angiogram (contrast agent: 300 to 350 mg/ml) on a 4- (n = 56), 16- (n = 119) and 64- (n = 39) detector-row scanner. The site of origin and distribution of bronchial arteries were analyzed on transverse CT scans, maximum intensity projections and volume-rendered images. The site of the ostium of a bronchial artery was coded as orthotopic when the artery originated from the descending aorta between the levels of the fifth and sixth thoracic vertebrae; all other bronchial arteries were considered ectopic. From the studied population, 137 (64%) patients had only orthotopic bronchial arteries, whereas 77 patients (36%) had at least one bronchial artery of ectopic origin. A total of 147 ectopic arteries were depicted, originating as common bronchial trunks (n = 23; 19%) or isolated right or left bronchial arteries (n = 101; 81%). The most frequent sites of origin of the 124 ostiums were the concavity of the aortic arch (92/124; 74%), the subclavian artery (13/124; 10.5%) and the descending aorta (10/124; 8.5%). The isolated ectopic bronchial arteries supplied the ipsilateral lung in all but three cases. Bronchial artery embolization was indicated in 26 patients. On the basis of CTA information, (1

  19. Pilot experimental study on continual spectrum thermal neutron in-line phase contrast radiography

    International Nuclear Information System (INIS)

    Tang Bin; Huo Heyong; Wu Yang

    2009-01-01

    The in-line phase contrast radiography is one of phase contrast imaging methods. The neutron in-line phase contrast is developed with X-rays phase contrast radiography. In the paper, the principle of in-line phase contrast is introduced briefly and the experimental result of thermal neutron in-line contrast at SPRR-300 is analysed. It shows that thermal neutron can be used as in-line phase contrast radiography and enhances the edge of some sample in radiography and complements the disadvantage of conventional neutron radiography. (authors)

  20. Volume-rendered hemorrhage-responsible arteriogram created by 64 multidetector-row CT during aortography: utility for catheterization in transcatheter arterial embolization for acute arterial bleeding.

    Science.gov (United States)

    Minamiguchi, Hiroki; Kawai, Nobuyuki; Sato, Morio; Ikoma, Akira; Sanda, Hiroki; Nakata, Kouhei; Tanaka, Fumihiro; Nakai, Motoki; Sonomura, Tetsuo; Murotani, Kazuhiro; Hosokawa, Seiki; Nishioku, Tadayoshi

    2014-01-01

    Aortography for detecting hemorrhage is limited when determining the catheter treatment strategy because the artery responsible for hemorrhage commonly overlaps organs and non-responsible arteries. Selective catheterization of untargeted arteries would result in repeated arteriography, large volumes of contrast medium, and extended time. A volume-rendered hemorrhage-responsible arteriogram created with 64 multidetector-row CT (64MDCT) during aortography (MDCTAo) can be used both for hemorrhage mapping and catheter navigation. The MDCTAo depicted hemorrhage in 61 of 71 cases of suspected acute arterial bleeding treated at our institute in the last 3 years. Complete hemostasis by embolization was achieved in all cases. The hemorrhage-responsible arteriogram was used for navigation during catheterization, thus assisting successful embolization. Hemorrhage was not visualized in the remaining 10 patients, of whom 6 had a pseudoaneurysm in a visceral artery; 1 with urinary bladder bleeding and 1 with chest wall hemorrhage had gaze tamponade; and 1 with urinary bladder hemorrhage and 1 with uterine hemorrhage had spastic arteries. Six patients with pseudoaneurysm underwent preventive embolization and the other 4 patients were managed by watchful observation. MDCTAo has the advantage of depicting the arteries responsible for hemoptysis, whether from the bronchial arteries or other systemic arteries, in a single scan. MDCTAo is particularly useful for identifying the source of acute arterial bleeding in the pancreatic arcade area, which is supplied by both the celiac and superior mesenteric arteries. In a case of pelvic hemorrhage, MDCTAo identified the responsible artery from among numerous overlapping visceral arteries that branched from the internal iliac arteries. In conclusion, a hemorrhage-responsible arteriogram created by 64MDCT immediately before catheterization is useful for deciding the catheter treatment strategy for acute arterial bleeding.

  1. Multidetector computed tomography arteriography in the preoperative assessment of patients with ureteropelvic junction obstruction

    Energy Technology Data Exchange (ETDEWEB)

    Braun, Petra [Department of Radiology, Hospital de la Plana, Ctra. de Vila-real a Borriana KM. 0.5, 12540 Vila-real (Spain)]. E-mail: PetraBraun@gmx.de; Guilabert, Jose Pamies [Department of Radiology, Hospital de la Plana, Ctra. de Vila-real a Borriana KM. 0.5, 12540 Vila-real (Spain); Kazmi, Faaiza [Department of Radiology, Penn State Milton S. Hershey Medical Center (United States)

    2007-01-15

    Background: Nowadays, endoscopic management of ureteropelvic junction (UPJ) obstruction is the treatment of choice. However, in the presence of crossing vessels, the success rate of endoscopic management decreases and the risk of hemorrhagic and vascular complications rises. The purpose of this study is to evaluate patients with UPJ obstruction using contrast enhanced multidetector computed tomography (CT) angiography to aid in surgical planning and management. Patients and methods: Between 2001 and 2005, 27 patients (mean age: 43 years; age range: 17-75 years) with UPJ obstruction were studied with multidetector CT angiography. Identification and characterization of crossing vessels was performed with multidirectional images and three-directional reconstructions. Results: 12 patients (44%) were found to have 16 crossing vessels (vessels in contact with the UPJ or within a vicinity of less than 2 mm). Nine of these vessels were arteries and seven were veins. Nine vessels crossed anteriorly, two posteriorly, and one anteromedially. Endopyelotomy was contraindicated in these 12 patients due to the presence of crossing vessels. Eleven out of the 12 patients underwent a pyeloplasty by open surgery or laparoscopy, where the presence of crossing vessels was confirmed. One of the 12 patients did not undergo surgery. Conclusion: Multidetector CT angiography permits an adequate preoperative assessment of patients with UPJ obstruction as it is able to identify the presence and location of crossing vessels. Furthermore, it allows to study in detail the anatomy of the renal area and its vascular variants.

  2. Evaluation of edge enhancement effect of phase contrast imaging using newly-developed photostimulable phosphor plate

    International Nuclear Information System (INIS)

    Matsuo, Satoru; Morishita, Junji; Katafuchi, Tetsuro; Fujita, Hiroshi

    2012-01-01

    We investigated whether the use of a newly developed columnar-crystal-type photostimulable-phosphor plate (CP1M200, referred to as system C) helps to provide improved edge-enhanced effect in phase contrast imaging. Physical characteristics of 2 conventional particulate-crystal-type photostimulable-phosphor plates (RP-5PM, referred to as system A and RP-6M, referred to as system B) and system C were measured. Then, an acrylic plate phantom and RMI152 phantom were imaged using 3 types of plates, and the edge-enhancement effects were evaluated based on the profile curve of the acrylic plate phantom. Visual evaluation of the RMI152 phantom images was conducted. The results showed that the modulation transfer function (MTF) of system C was superior to those of the other systems. The WS of system C was superior to those of the other systems in the low frequency band region, and inferior to those of the other systems in the high frequency band region. The presence of an edge-enhanced image was not detectable in the profile curve of the acrylic plate in system A, although that was shown in systems B and C due to their excellent sharpness. In the visual image evaluation of the RMI152 phantom, image quality of system C was superior to those of the other systems. Phase contrast imaging with a digital detector of a columnar-crystal-type photostimulable-phosphor plate is considered to provide improved edge-enhancement over that of conventional plates. (author)

  3. Characterizing the contrast of white matter and grey matter in high-resolution phase difference enhanced imaging of human brain at 3.0 T

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Li [Fudan University, Department of Radiology, Shanghai Institute of Medical Imaging, Zhongshan Hospital, Shanghai (China); Shandong University, Shandong Medical Imaging Research Institute, Shandong Provincial Key Laboratory of Diagnosis and Treatment of Cardio-cerebral Vascular Diseases, Jinan, Shandong (China); Wang, Shanshan; Yao, Bin; Li, Lili; Guo, Lingfei; Zhang, Xinjuan; Wang, Guangbin [Shandong University, Shandong Medical Imaging Research Institute, Shandong Provincial Key Laboratory of Diagnosis and Treatment of Cardio-cerebral Vascular Diseases, Jinan, Shandong (China); Xu, Xiaofei [Erasmus University Rotterdam, Laboratory of Experimental Tumor Immunology, Department of Medical Oncology, Erasmus Medical Center Cancer Institute, Rotterdam (Netherlands); Zhao, Lianxin [Shandong University, Department of Radiology, Qilu Hospital, Jinan, Shandong (China); Chen, Weibo; Chan, Queenie [Philips Healthcare, Shanghai (China)

    2015-04-01

    The purpose of this study was to address the feasibility of characterizing the contrast both between and within grey matter and white matter using the phase difference enhanced (PADRE) technique. PADRE imaging was performed in 33 healthy volunteers. Vessel enhancement (VE), tissue enhancement (TE), and PADRE images were reconstructed from source images and were evaluated with regard to differentiation of grey-to-white matter interface, the stria of Gennari, and the two layers, internal sagittal stratum (ISS) and external sagittal stratum (ESS), of optic radiation. White matter regions showed decreased signal intensity compared to grey matter regions. Discrimination was sharper between white matter and cortical grey matter in TE images than in PADRE images, but was poorly displayed in VE images. The stria of Gennari was observed on all three image sets. Low-signal-intensity bands displayed in VE images representing the optic radiation were delineated as two layers of different signal intensities in TE and PADRE images. Statistically significant differences in phase shifts were found between frontal grey and white matter, as well as between ISS and ESS (p < 0.01). The PADRE technique is capable of identifying grey-to-white matter interface, the stria of Gennari, and ISS and ESS, with improved contrast in PADRE and TE images compared to VE images. (orig.)

  4. Characterizing the contrast of white matter and grey matter in high-resolution phase difference enhanced imaging of human brain at 3.0 T

    International Nuclear Information System (INIS)

    Yang, Li; Wang, Shanshan; Yao, Bin; Li, Lili; Guo, Lingfei; Zhang, Xinjuan; Wang, Guangbin; Xu, Xiaofei; Zhao, Lianxin; Chen, Weibo; Chan, Queenie

    2015-01-01

    The purpose of this study was to address the feasibility of characterizing the contrast both between and within grey matter and white matter using the phase difference enhanced (PADRE) technique. PADRE imaging was performed in 33 healthy volunteers. Vessel enhancement (VE), tissue enhancement (TE), and PADRE images were reconstructed from source images and were evaluated with regard to differentiation of grey-to-white matter interface, the stria of Gennari, and the two layers, internal sagittal stratum (ISS) and external sagittal stratum (ESS), of optic radiation. White matter regions showed decreased signal intensity compared to grey matter regions. Discrimination was sharper between white matter and cortical grey matter in TE images than in PADRE images, but was poorly displayed in VE images. The stria of Gennari was observed on all three image sets. Low-signal-intensity bands displayed in VE images representing the optic radiation were delineated as two layers of different signal intensities in TE and PADRE images. Statistically significant differences in phase shifts were found between frontal grey and white matter, as well as between ISS and ESS (p < 0.01). The PADRE technique is capable of identifying grey-to-white matter interface, the stria of Gennari, and ISS and ESS, with improved contrast in PADRE and TE images compared to VE images. (orig.)

  5. High contrast enhancement aspect of dynamic computed tomography with arterial infusion - DCT-AI

    International Nuclear Information System (INIS)

    Kato, Seishi; Iwasaki, Naoya; Matsumura, Yoshimitsu; Kuramae, Shigeru; Mishiro, Tadashi

    1983-01-01

    Dynamic computed tomography was performed on 112 cases possibly having hepatic tumors with intraarterial infusion of undiluted contrast into a selectively placed catheter following angiographies. Our dynamic program could evaluate not only early phase of enhancement but also late phase up to 120 sec. Reconstructed views from early scans and magnified views were very useful to evaluate minute sequential changes. Hepatic masses less than 5 cm in size were found in thirty-one cases. Patterns of tumor enhancement and time-density curves have been analysed to correlate them with histology. Four types of tumor enhancement were noted: (1) homogeneous (2) patchy (3) mottled (4) ringed. Characteristic changes were observed in hepatocellular carcinoma - HCC - (mostly mottled) and haemangioma (mostly patchy). The former was divided in two groups reflecting the cellular maturity. The metastatic tumor could be enhanced in a ringed form with dendritic pattern of supplying vascularities in some cases. To support the use of undiluted contrast and to investigate the diagnostic efficacy of high contrast enhancement, experiments were performed by taking transaxial views of an acrylic phantom immersed in different concentrations of contrast. Analysis of CT images taken at different HU values ranging from 0 to 450 demonstrated that the higher the concentration of contrast, the better the spatial resolution was. Also larger magnification could be expected by using higher concentration of contrast. Although our Dynamic Computed Tomography with Arterial Infusion of Contrast still has drawbacks and limited indications, we advocate it as a better way of enhancement to detect and evaluate the hepatic masses, which sometimes elude the examiner's grasp with conventional way of enhancement. (author)

  6. Dynamic contrast-enhanced MRI of the prostate. Comparison of two different post-processing algorithms

    International Nuclear Information System (INIS)

    Beyersdorff, Dirk; Franiel, T.; Luedemann, L.; Dietz, E.; Galler, D.; Marchot, P.

    2011-01-01

    Purpose: To evaluate the usefulness of a commercially available post-processing software tool for detecting prostate cancer on dynamic contrast-enhanced magnetic resonance imaging (MRI) and to compare the results to those obtained with a custom-made post-processing algorithm already tested under clinical conditions. Materials and Methods: Forty-eight patients with proven prostate cancer were examined by standard MRI supplemented by dynamic contrast-enhanced dual susceptibility contrast (DCE-DSC) MRI prior to prostatectomy. A custom-made post-processing algorithm was used to analyze the MRI data sets and the results were compared to those obtained using a post-processing algorithm from Invivo Corporation (Dyna CAD for Prostate) applied to dynamic T 1-weighted images. Histology was used as the gold standard. Results: The sensitivity for prostate cancer detection was 78 % for the custom-made algorithm and 60 % for the commercial algorithm and the specificity was 79 % and 82 %, respectively. The accuracy was 79 % for our algorithm and 77.5 % for the commercial software tool. The chi-square test (McNemar-Bowker test) yielded no significant differences between the two tools (p = 0.06). Conclusion: The two investigated post-processing algorithms did not differ in terms of prostate cancer detection. The commercially available software tool allows reliable and fast analysis of dynamic contrast-enhanced MRI for the detection of prostate cancer. (orig.)

  7. Phase retrieval for X-ray in-line phase contrast imaging

    International Nuclear Information System (INIS)

    Scattarella, F.; Bellotti, R.; Tangaro, S.; Gargano, G.; Giannini, C.

    2011-01-01

    A review article about phase retrieval problem in X-ray phase contrast imaging is presented. A simple theoretical framework of Fresnel diffraction imaging by X-rays is introduced. A review of the most important methods for phase retrieval in free-propagation-based X-ray imaging and a new method developed by our collaboration are shown. The proposed algorithm, Combined Mixed Approach (CMA) is based on a mixed transfer function and transport of intensity approach, and it requires at most an initial approximate estimate of the average phase shift introduced by the object as prior knowledge. The accuracy with which this initial estimate is known determines the convenience speed of algorithm. The new proposed algorithm is based on the retrieval of both the object phase and its complex conjugate. The results obtained by the algorithm on simulated data have shown that the obtained reconstructed phase maps are characterized by particularly low normalized mean square errors. The algorithm was also tested on noisy experimental phase contrast data, showing a good efficiency in recovering phase information and enhancing the visibility of details inside soft tissues.

  8. Dynamic contrast-enhanced MR of the prostatic cancer and benign prostatic hyperplasia: correlation with angiogenesis

    International Nuclear Information System (INIS)

    Ni Xinchu; Shen Junkang; Lu Zhian; Zhou Lijuan; Yang Xiaochun; Wang Guanzhong; Zhang Caiyuan; Wang Shuizhen; Qian Minghui; Chan Yuxi; Qian Nong; Xiang Jianpo; Pan Changjie; Rong Weiliang; Chen Jianguo

    2005-01-01

    Objective: To evaluate the role of dynamic contrast-enhanced magnetic resonance imaging (MRI) in the diagnose of prostatic cancer and benign prostatic hyperplasia (BPH), and to determine the correlation between dynamic MRI findings with angiogenesis. Methods: Thirty-two cases of prostatic cancer and 40 cases of BPH underwent dynamic contrast-enhanced MRI. All the patients in this study were diagnosed by histopathology. The results of dynamic contrast-enhanced MRI were evaluated by early-phase enhancement parameters and time-signal intensity curves (SI-T curves), and the curves were classified according to their shapes as type I, which had steady enhancement; type II, plateau of signal intensity; and type III, washout of signal intensity. The pathologic specimens of region of interest (ROI ) were obtained, and HE staining, immunohistochemical vascular endothelial growth factor (VEGF), and microvessel density (MVD) measurements were performed. The relationships among dynamic contrast-enhanced MRI features, VEGF, and MVD expression were analyzed. Results: In the early-phase enhancement parameters of dynamic contrast-enhanced MRI, onset time, maximum signal intensity, and early-phase enhancement rate differed between prostatic cancer and BPH (P<0.01, 0.05, 0.01), but there were some overlaps between them. The intermediate and late post-contrast periods were characterized with the lesion SI-T curves. The SI-T curve of prostatic cancer was mainly type III (21 cases). Type II could be seen in both prostatic cancer (8 cases) and BPH (19 cases). Type I most appeared in BPH (18 cases). The distributions proved to have significant difference (P<0.001). The mean VEGF and MVD level of 32 prostatic cancer patients were significantly higher than those of 40 BPH patients (P<0.001). MVD level of prostatic cancer and BPH showed an association with VEGF level (P<0.01). The maximum signal intensity and early-phase enhancement rate in both prostatic cancer and BPH showed an association

  9. Development of an automated extraction method for liver tumors in three dimensional multiphase multislice CT images

    International Nuclear Information System (INIS)

    Nakagawa, Junya; Shimizu, Akinobu; Kobatake, Hidefumi

    2004-01-01

    This paper proposes a tumor detection method using four phase three dimensional (3D) CT images of livers, i.e. non-contrast, early, portal, and late phase images. The method extracts liver regions from the four phase images and enhances tumors in the livers using a 3D adaptive convergence index filter. Then it detects local maximum points and extracts tumor candidates by a region growing method. Subsequently several features of the candidates are measured and each candidate is classified into true tumor or normal tissue based on Mahalanobis distances. Above processes except liver region extraction are applied to four phase images, independently and four resultant images are integrated into one. We applied the proposed method to 3D abdominal CT images of ten patients obtained with multi-detector row CT scanner and confirmed that tumor detection rate was 100% without false positives, which was quite promising results. (author)

  10. Findings in multidetector computed tomography in the diagnosis of hepatocellular carcinoma in patients with cirrhosis and correlation with pathology of liver explants

    International Nuclear Information System (INIS)

    Haberman, D.; Castignola, M.; Mela, M.; Paladini, H.; Santilli, J.P.; Gruz, F.; Gondolesi, G.

    2013-01-01

    Objectives: To describe the imagenological behavior of hepatocellular carcinoma in cirrhotic patients using a dynamic multidetector computed tomography (MDCT) technique, and correlate these findings with histological tumor grades. Materials and methods: A retrospective, descriptive observational study was conducted to evaluate 51 nodules in 32 liver transplant patients diagnosed with liver cirrhosis. The pathology of liver explants was used as a reference. Nodules with hepatocellular carcinoma histopathology were retrospectively analyzed by computed tomography scans performed pre-transplant. Using a dynamic multidetector computed tomography technique, we evaluated the most common imagenological behavior reported in the literature: arterial enhancement, washout, capsule, and intratumoral arterial vessels. Results: Forty-six of 51 (90%) tumors showed arterial enhancement. Of the 46 tumors with arterial enhancement, 39 (85%) had washout in portal-late phase. Five of 51 (10%) were hypovascular. Twenty-two of 51 (43%) had capsule and 12 of 51 (24%) showed intratumoral arterial vessels. The more frequent image combination was the combination of arterial enhancement and washout (39 of 51 tumors or 76%). The most frequent histological grade was II (35 of 51 tumors or 69%). Statistically significant relationships were found between histological grade tumors and imagenological behavior: arterial enhancement and hypovascular. Conclusion: In our population, arterial enhancement with washout in portal-late phases was observed in most of the tumors. Our results are consistent with previously reported studies, demonstrating the high reliability of this imaging pattern for the diagnosis of hepatocellular carcinoma. (authors) [es

  11. Multidetector Computed Tomography in the Preoperative Workup of Hilar Cholangiocarcinoma

    International Nuclear Information System (INIS)

    Kim, Hyoung Jung; Lee, Dong Ho; Lim, Joo Won; Ko, Young Tae

    2009-01-01

    Hilar cholangiocarcinoma is associated with a dismal prognosis; however, curative resection may offer a chance of cure. Various factors should be considered in the surgical planning for curative resection. These factors include extent of bile duct involvement, relationship between portal vein and tumor involvement, diffuse hepato duodenal ligament infiltration, vascular invasion, lymph node metastasis, peritoneal seeding, and hepatic volume. Using high-quality volume data from multidetector-row computed tomography (MDCT) and adequate postprocessing images, radiologists can provide various types of information, imperative for curative resection of a hilar cholangiocarcinoma. This review illustrates the role of MDCT in the preoperative workup of hilar cholangiocarcinoma

  12. Spline based iterative phase retrieval algorithm for X-ray differential phase contrast radiography.

    Science.gov (United States)

    Nilchian, Masih; Wang, Zhentian; Thuering, Thomas; Unser, Michael; Stampanoni, Marco

    2015-04-20

    Differential phase contrast imaging using grating interferometer is a promising alternative to conventional X-ray radiographic methods. It provides the absorption, differential phase and scattering information of the underlying sample simultaneously. Phase retrieval from the differential phase signal is an essential problem for quantitative analysis in medical imaging. In this paper, we formalize the phase retrieval as a regularized inverse problem, and propose a novel discretization scheme for the derivative operator based on B-spline calculus. The inverse problem is then solved by a constrained regularized weighted-norm algorithm (CRWN) which adopts the properties of B-spline and ensures a fast implementation. The method is evaluated with a tomographic dataset and differential phase contrast mammography data. We demonstrate that the proposed method is able to produce phase image with enhanced and higher soft tissue contrast compared to conventional absorption-based approach, which can potentially provide useful information to mammographic investigations.

  13. Phase contrast image synthesis

    DEFF Research Database (Denmark)

    Glückstad, J.

    1996-01-01

    A new method is presented for synthesizing arbitrary intensity patterns based on phase contrast imaging. The concept is grounded on an extension of the Zernike phase contrast method into the domain of full range [0; 2 pi] phase modulation. By controlling the average value of the input phase funct...... function and by choosing appropriate phase retardation at the phase contrast filter, a pure phase to intensity imaging is accomplished. The method presented is also directly applicable in dark field image synthesis....

  14. Combined mixed approach algorithm for in-line phase-contrast x-ray imaging

    International Nuclear Information System (INIS)

    De Caro, Liberato; Scattarella, Francesco; Giannini, Cinzia; Tangaro, Sabina; Rigon, Luigi; Longo, Renata; Bellotti, Roberto

    2010-01-01

    Purpose: In the past decade, phase-contrast imaging (PCI) has been applied to study different kinds of tissues and human body parts, with an increased improvement of the image quality with respect to simple absorption radiography. A technique closely related to PCI is phase-retrieval imaging (PRI). Indeed, PCI is an imaging modality thought to enhance the total contrast of the images through the phase shift introduced by the object (human body part); PRI is a mathematical technique to extract the quantitative phase-shift map from PCI. A new phase-retrieval algorithm for the in-line phase-contrast x-ray imaging is here proposed. Methods: The proposed algorithm is based on a mixed transfer-function and transport-of-intensity approach (MA) and it requires, at most, an initial approximate estimate of the average phase shift introduced by the object as prior knowledge. The accuracy in the initial estimate determines the convergence speed of the algorithm. The proposed algorithm retrieves both the object phase and its complex conjugate in a combined MA (CMA). Results: Although slightly less computationally effective with respect to other mixed-approach algorithms, as two phases have to be retrieved, the results obtained by the CMA on simulated data have shown that the obtained reconstructed phase maps are characterized by particularly low normalized mean square errors. The authors have also tested the CMA on noisy experimental phase-contrast data obtained by a suitable weakly absorbing sample consisting of a grid of submillimetric nylon fibers as well as on a strongly absorbing object made of a 0.03 mm thick lead x-ray resolution star pattern. The CMA has shown a good efficiency in recovering phase information, also in presence of noisy data, characterized by peak-to-peak signal-to-noise ratios down to a few dBs, showing the possibility to enhance with phase radiography the signal-to-noise ratio for features in the submillimetric scale with respect to the attenuation

  15. Imaging of Acute Mesenteric Ischemia Using Multidetector CT and CT Angiography in a Porcine Model

    OpenAIRE

    Rosow, David E.; Sahani, Dushyant; Strobel, Oliver; Kalva, Sanjeeva; Mino-Kenudson, Mari; Holalkere, Nagaraj S.; Alsfasser, Guido; Saini, Sanjay; Lee, Susanna I.; Mueller, Peter R.; Castillo, Carlos Fernández-del; Warshaw, Andrew L.; Thayer, Sarah P.

    2005-01-01

    Acute mesenteric ischemia, a frequently lethal disease, requires prompt diagnosis and intervention for favorable clinical outcomes. This goal remains elusive due, in part, to lack of a noninvasive and accurate imaging study. Traditional angiography is the diagnostic gold standard but is invasive and costly. Computed tomography (CT) is readily available and noninvasive but has shown variable success in diagnosing this disease. The faster scanning time of multidetector row CT (M.D.CT) greatly f...

  16. Congenital anomalies of coronary arteries: Diagnosis with 64 slice multidetector CT

    Energy Technology Data Exchange (ETDEWEB)

    Tariq, Rukhsana, E-mail: drrukhsanatariq@hotmail.com [Consultant Radiologists, Advanced Radiology Clinic, Behind Hamdard University Hospital, Off M.A. Jinnah Road, Karachi (Pakistan); Kureshi, Shahzad Babar [Consultant Radiologists, Advanced Radiology Clinic, Behind Hamdard University Hospital, Off M.A. Jinnah Road, Karachi (Pakistan); Siddiqui, Usman T. [Medical College, Aga Khan University, Karachi (Pakistan); Ahmed, Rashid [Consultant Radiologists, Advanced Radiology Clinic, Behind Hamdard University Hospital, Off M.A. Jinnah Road, Karachi (Pakistan)

    2012-08-15

    Objective: Congenital coronary artery anomalies are generally incidental, uncommon and asymptomatic. Some can cause severe potentially life threatening symptoms. The common mode of studying the coronary arteries is Conventional Coronary Angiogram. ECG-gated-multidetector CT is a non invasive modality. The objective of our study was to identify rare congenital coronary artery anomalies and discuss their clinical significance. Material and methods: A total number of 900 MDCT coronary angiograms were carried out at our institution between the period of April 2006 and October 2010. Patients with coronary artery anomaly constituted the subject of study. Results: The incidence of anomalous anatomical origin and course of the coronary arteries in our study was 1.55%. Hemodynamical significance was seen in five patients. 3 cases of single coronary artery originating from right coronary sinus were seen. 1 case of anomalous left coronary artery arising from main pulmonary artery was seen. 4 cases of anomalous RCA arising from left aortic cusp, 6 cases of absent LMCA with separate origin of LAD and LCX were seen. Conclusion: Multidetector row CT is a noninvasive modality in cardiac imaging. It provides superior resolution of coronary tree and its variant. No projectional vascular overlap is seen. Various postprocessing techniques outclass catheter angiography imaging. Definition of ostia and proximal course of the coronary arteries by Multidetector CT is better than catheter angiography.

  17. Congenital anomalies of coronary arteries: Diagnosis with 64 slice multidetector CT

    International Nuclear Information System (INIS)

    Tariq, Rukhsana; Kureshi, Shahzad Babar; Siddiqui, Usman T.; Ahmed, Rashid

    2012-01-01

    Objective: Congenital coronary artery anomalies are generally incidental, uncommon and asymptomatic. Some can cause severe potentially life threatening symptoms. The common mode of studying the coronary arteries is Conventional Coronary Angiogram. ECG-gated-multidetector CT is a non invasive modality. The objective of our study was to identify rare congenital coronary artery anomalies and discuss their clinical significance. Material and methods: A total number of 900 MDCT coronary angiograms were carried out at our institution between the period of April 2006 and October 2010. Patients with coronary artery anomaly constituted the subject of study. Results: The incidence of anomalous anatomical origin and course of the coronary arteries in our study was 1.55%. Hemodynamical significance was seen in five patients. 3 cases of single coronary artery originating from right coronary sinus were seen. 1 case of anomalous left coronary artery arising from main pulmonary artery was seen. 4 cases of anomalous RCA arising from left aortic cusp, 6 cases of absent LMCA with separate origin of LAD and LCX were seen. Conclusion: Multidetector row CT is a noninvasive modality in cardiac imaging. It provides superior resolution of coronary tree and its variant. No projectional vascular overlap is seen. Various postprocessing techniques outclass catheter angiography imaging. Definition of ostia and proximal course of the coronary arteries by Multidetector CT is better than catheter angiography.

  18. 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.

  19. Domain decomposition parallel computing for transient two-phase flow of nuclear reactors

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jae Ryong; Yoon, Han Young [KAERI, Daejeon (Korea, Republic of); Choi, Hyoung Gwon [Seoul National University, Seoul (Korea, Republic of)

    2016-05-15

    KAERI (Korea Atomic Energy Research Institute) has been developing a multi-dimensional two-phase flow code named CUPID for multi-physics and multi-scale thermal hydraulics analysis of Light water reactors (LWRs). The CUPID code has been validated against a set of conceptual problems and experimental data. In this work, the CUPID code has been parallelized based on the domain decomposition method with Message passing interface (MPI) library. For domain decomposition, the CUPID code provides both manual and automatic methods with METIS library. For the effective memory management, the Compressed sparse row (CSR) format is adopted, which is one of the methods to represent the sparse asymmetric matrix. CSR format saves only non-zero value and its position (row and column). By performing the verification for the fundamental problem set, the parallelization of the CUPID has been successfully confirmed. Since the scalability of a parallel simulation is generally known to be better for fine mesh system, three different scales of mesh system are considered: 40000 meshes for coarse mesh system, 320000 meshes for mid-size mesh system, and 2560000 meshes for fine mesh system. In the given geometry, both single- and two-phase calculations were conducted. In addition, two types of preconditioners for a matrix solver were compared: Diagonal and incomplete LU preconditioner. In terms of enhancement of the parallel performance, the OpenMP and MPI hybrid parallel computing for a pressure solver was examined. It is revealed that the scalability of hybrid calculation was enhanced for the multi-core parallel computation.

  20. 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.

  1. Iodine quantification to distinguish clear cell from papillary renal cell carcinoma at dual-energy multidetector CT: a multireader diagnostic performance study.

    Science.gov (United States)

    Mileto, Achille; Marin, Daniele; Alfaro-Cordoba, Marcela; Ramirez-Giraldo, Juan Carlos; Eusemann, Christian D; Scribano, Emanuele; Blandino, Alfredo; Mazziotti, Silvio; Ascenti, Giorgio

    2014-12-01

    To investigate whether dual-energy multidetector row computed tomographic (CT) imaging with iodine quantification is able to distinguish between clear cell and papillary renal cell carcinoma ( RCC renal cell carcinoma ) subtypes. In this retrospective, HIPAA-compliant, institutional review board-approved study, 88 patients (57 men, 31 women) with diagnosis of either clear cell or papillary RCC renal cell carcinoma at pathologic analysis, who underwent contrast material-enhanced dual-energy nephrographic phase study between December 2007 and June 2013, were included. Five readers, blinded to pathologic diagnosis, independently evaluated all cases by determining the lesion iodine concentration on color-coded iodine maps. The receiving operating characteristic curve analysis was adopted to estimate the optimal threshold for discriminating between clear cell and papillary RCC renal cell carcinoma , and results were validated by using a leave-one-out cross-validation. Interobserver agreement was assessed by using an intraclass correlation coefficient. The correlation between tumor iodine concentration and tumor grade was investigated. A tumor iodine concentration of 0.9 mg/mL represented the optimal threshold to discriminate between clear cell and papillary RCC renal cell carcinoma , and it yielded the following: sensitivity, 98.2% (987 of 1005 [95% confidence interval: 97.7%, 98.7%]); specificity, 86.3% (272 of 315 [95% confidence interval: 85.0%, 87.7%]); positive predictive value, 95.8% (987 of 1030 [95% confidence interval: 95.0%, 96.6%]); negative predictive value, 93.7% (272 of 290 [95% confidence interval: 92.8%, 94.7%]); overall accuracy of 95.3% (1259 of 1320 [95% confidence interval: 94.6%, 96.2%]), with an area under the curve of 0.923 (95% confidence interval: 0.913, 0.933). An excellent agreement was found among the five readers in measured tumor iodine concentration (intraclass correlation coefficient, 0.9990 [95% confidence interval: 0. 9987, 0.9993). A

  2. Diagnostic performance of combined noninvasive coronary angiography and myocardial perfusion imaging using 320 row detector computed tomography

    DEFF Research Database (Denmark)

    Vavere, Andrea L; Simon, Gregory G; George, Richard T

    2013-01-01

    Multidetector coronary computed tomography angiography (CTA) is a promising modality for widespread clinical application because of its noninvasive nature and high diagnostic accuracy as found in previous studies using 64 to 320 simultaneous detector rows. It is, however, limited in its ability...... to detect myocardial ischemia. In this article, we describe the design of the CORE320 study ("Combined coronary atherosclerosis and myocardial perfusion evaluation using 320 detector row computed tomography"). This prospective, multicenter, multinational study is unique in that it is designed to assess...... the diagnostic performance of combined 320-row CTA and myocardial CT perfusion imaging (CTP) in comparison with the combination of invasive coronary angiography and single-photon emission computed tomography myocardial perfusion imaging (SPECT-MPI). The trial is being performed at 16 medical centers located in 8...

  3. X-ray phase-contrast tomosynthesis for improved breast tissue discrimination

    International Nuclear Information System (INIS)

    Schleede, Simone; Bech, Martin; Grandl, Susanne; Sztrókay, Aniko; Herzen, Julia; Mayr, Doris; Stockmar, Marco; Potdevin, Guillaume

    2014-01-01

    Purpose: Attenuation-based tomosynthesis has proven to successfully resolve the glandular tissue overlap present in mammography. However, the ability of tomosynthesis to differentiate tumorous and glandular tissue remains limited, due to the small differences in X-ray attenuation in breast tissue. One possibility to overcome this limitation and to further increase the diagnostic value of tomosynthesis exams, is the application of recently developed grating-based phase-contrast methods, which provide complementary information on the phase shift and the local scattering power of the sample. In this study, we report on first phase-contrast breast tomosynthesis results of a mastectomy sample slice with an invasive ductal carcinoma. Material and methods: A slice of a mastectomy sample with histologically proven invasive ductal cancer was imaged at the synchrotron radiation source ESRF (Grenoble, France). We used a two-grating interferometer setup at the ninth fractional Talbot distance and with an X-ray energy of 23 keV. In grating interferometry absorption, differential phase, and scattering images are recorded simultaneously. The tomosynthesis scan comprises 61 projections. Multimodal tomosynthesis results were reconstructed using a standard filtered back-projection approach. Our findings are supported by a comparison of tomographic views to histopathology. Results: Phase-contrast tomosynthesis combines the advantage of improved soft-tissue discrimination in phase-contrast imaging with the ability of tomosynthesis to provide a third dimension so that improved feature visibility is not hampered by superposition artifacts. Our results indicate superior diagnostic value due to the depth resolution supplied in tomosynthesis imaging; a region of necrotic tissue that is obscured in a projection image can clearly be depicted in one single tomosynthesis slice. Compared to absorption tomosynthesis alone, soft tissue contrast is significantly enhanced in phase-contrast

  4. X-ray phase-contrast tomosynthesis for improved breast tissue discrimination.

    Science.gov (United States)

    Schleede, Simone; Bech, Martin; Grandl, Susanne; Sztrókay, Aniko; Herzen, Julia; Mayr, Doris; Stockmar, Marco; Potdevin, Guillaume; Zanette, Irene; Rack, Alexander; Weitkamp, Timm; Pfeiffer, Franz

    2014-03-01

    Attenuation-based tomosynthesis has proven to successfully resolve the glandular tissue overlap present in mammography. However, the ability of tomosynthesis to differentiate tumorous and glandular tissue remains limited, due to the small differences in X-ray attenuation in breast tissue. One possibility to overcome this limitation and to further increase the diagnostic value of tomosynthesis exams, is the application of recently developed grating-based phase-contrast methods, which provide complementary information on the phase shift and the local scattering power of the sample. In this study, we report on first phase-contrast breast tomosynthesis results of a mastectomy sample slice with an invasive ductal carcinoma. A slice of a mastectomy sample with histologically proven invasive ductal cancer was imaged at the synchrotron radiation source ESRF (Grenoble, France). We used a two-grating interferometer setup at the ninth fractional Talbot distance and with an X-ray energy of 23 keV. In grating interferometry absorption, differential phase, and scattering images are recorded simultaneously. The tomosynthesis scan comprises 61 projections. Multimodal tomosynthesis results were reconstructed using a standard filtered back-projection approach. Our findings are supported by a comparison of tomographic views to histopathology. Phase-contrast tomosynthesis combines the advantage of improved soft-tissue discrimination in phase-contrast imaging with the ability of tomosynthesis to provide a third dimension so that improved feature visibility is not hampered by superposition artifacts. Our results indicate superior diagnostic value due to the depth resolution supplied in tomosynthesis imaging; a region of necrotic tissue that is obscured in a projection image can clearly be depicted in one single tomosynthesis slice. Compared to absorption tomosynthesis alone, soft tissue contrast is significantly enhanced in phase-contrast tomosynthesis views, where fibrous structures

  5. MDCT urography: retrospective determination of optimal delay time after intravenous contrast administration

    International Nuclear Information System (INIS)

    Meindl, Thomas; Coppenrath, Eva; Kahlil, Rami; Reiser, Maximilian F.; Mueller-Lisse, U.G.; Mueller-Lisse, Ulrike L.

    2006-01-01

    The optimal delay time after intravenous (i.v.) administration of contrast medium (CM) for opacifcation of the upper urinary tract (UUT) for multidetector computed tomography urography (MDCTU) was investigated. UUT opacification was retrospectively evaluated in 36 four-row MDCTU examinations. Single- (n=10) or dual-phase (n=26) MDCTU was performed with at least 5-min delay after i.v. CM. UUT was divided into four sections: intrarenal collecting system (IRCS), proximal, middle and distal ureter. Two independent readers rated UUT opacification: 1, none; 2, partial; 3, complete. Numbers and percentages of scores, and the 5%, 25%, 50%, 75% and 95% percentiles of delay time were calculated for each UUT section. After removing diseased segments, 344 segments were analysed. IRCS, proximal and middle ureter were completely opacified in 94% (81/86), 93% (80/86) and 77% (66/86) of cases, respectively. Median delay time was 15 min for complete opacification. The distal ureter was completely opacified in 37% (32/86) of cases and not opacified in 26% (22/86). Median delay time for complete opacification was 11 min with 25% and 75% percentiles of 10 and 16 min, respectively. At MDCTU, opacification of the IRCS, proximal and middle ureter was hardly sensitive to delay time. Delay times between 10 and 16 min were favourable in the distal ureter. (orig.)

  6. Experimental validation of the Wigner distributions theory of phase-contrast imaging

    International Nuclear Information System (INIS)

    Donnelly, Edwin F.; Price, Ronald R.; Pickens, David R.

    2005-01-01

    Recently, a new theory of phase-contrast imaging has been proposed by Wu and Liu [Med. Phys. 31, 2378-2384 (2004)]. This theory, based upon Wigner distributions, provides a much stronger foundation for the evaluation of phase-contrast imaging systems than did the prior theories based upon Fresnel-Kirchhoff diffraction theory. In this paper, we compare results of measurements made in our laboratory of phase contrast for different geometries and tube voltages to the predictions of the Wu and Liu model. In our previous publications, we have used an empirical measurement (the edge enhancement index) to parametrize the degree of phase-contrast effects in an image. While the Wu and Liu model itself does not predict image contrast, it does measure the degree of phase contrast that the system can image for a given spatial frequency. We have found that our previously published experimental results relating phase-contrast effects to geometry and x-ray tube voltage are consistent with the predictions of the Wu and Liu model

  7. Contrast-enhanced ultrasound in diagnosis and characterization of focal hepatic lesions.

    Science.gov (United States)

    Molins, Inés Gómez; Font, Juan Manuel Fernández; Alvaro, Juan Carrero; Navarro, Jose Luís Lledó; Gil, Marta Fernández; Rodríguez, Conrado M Fernández

    2010-12-28

    The extensive use of imaging techniques in differential diagnosis of abdominal conditions and screening of hepatocellular carcinoma in patients with chronic hepatic diseases, has led to an important increase in identification of focal liver lesions. The development of contrast-enhanced ultrasound (CEUS) opens a new window in the diagnosis and follow-up of these lesions. This technique offers obvious advantages over the computed tomography and magnetic resonance, without a decrease in its sensitivity and specificity. The new second generation contrast agents, due to their intravascular distribution, allow a continuous evaluation of the enhancement pattern, which is crucial in characterization of liver lesions. The dual blood supply in the liver shows three different phases, namely arterial, portal and late phases. The enhancement during portal and late phases can give important information about the lesion's behavior. Each liver lesion has a different enhancement pattern that makes possible an accurate approach to their diagnosis. The role of emerging techniques as a contrast-enhanced three-dimensional US is also discussed. In this article, the advantages, indications and technique employed during CEUS and the different enhancement patterns of most benign and malignant focal liver lesions are discussed.

  8. Phase-contrast X-ray CT imaging of the kidney. Differences between ethanol fixation and formalin fixation

    International Nuclear Information System (INIS)

    Shirai, Ryota; Kunii, Takuya; Maruyama, Hiroko; Takeda, Tohoru; Yoneyama, Akio; Lwin, Thet Thet

    2012-01-01

    A phase-contrast X-ray imaging technique using an X-ray interferometer that provides approximately 1000 times higher sensitivity than the conventional X-ray imaging method for low-atomic number elements based on the difference in the mass attenuation coefficient has recently been developed. In the present study, we compared rat kidneys fixed in 100% ethanol and in 10% formalin to evaluate the effects of ethanol in enhancing image contrast in phase-contrast imaging because ethanol causes significant dehydration of tissues and enhances density differences between tissue components. The experiments were conducted at the Photon Factory in Tsukuba, and the X-ray energy was set at 35 keV. Fine anatomical structures in the kidney such as the glomeruli, tubules, and vessels were observed. Particularly clear renal images were obtained with ethanol fixation. The pixel value ratio between the cortex and medulla was about 43% in ethanol-fixed kidneys and 21% in formalin-fixed kidneys. In other words, the contrast in ethanol-fixed kidneys was about two times higher than that in formalin-fixed kidneys. Histological examination showed significantly condensed features in the cortex. The results of this study suggest that the ethanol fixation technique may be useful for enhancing the image contrast of renal structures in the phase-contrast X-ray imaging technique. (author)

  9. Contrast-enhanced MR angiography in Leriche's syndrome

    International Nuclear Information System (INIS)

    Link, J.; Steffens, J.C.; Brossmann, J.; Heller, M.; Loose, R.

    1998-01-01

    Purpose: To determine the usefulness of contrast-enhanced MR angiography for the diagnosis of Leriche's syndrome. Material and methods: Leriche's syndrome was seen in 7 patients via DSA. In [dition, contrast-enhanced MR angiography was performed (T R 7.8 ms/T E 2.1 ms, flip angle 30 , slab thickness 116 mm, slice thickness 1.82 mm, 64 partitions, FOV 500x438 mm, matrix 224x512). Results: Diagnosis of Leriche's syndrome was possible by contrast-enhanced MR angiography in each case. Visualisation of the femoral arteries was not possible in two patients by intraarterial DSA, in three other patients there was an insufficient contrast in the femoral arteries with DSA. Contrast-enhanced MR angiography revealed good visualisation of the femoral arteries in these patients. In [dition, contrast-enhanced MR angiography allowed complete visualisation of the patent lower limb arteries. In intraarterial DSA visualisation of the lower limb arteries was achieved reached in only one patient, but was incomplete. Conclusion: Contrast-enhanced MR angiography yielded the correct diagnosis of Leriche's syndrome in all 7 patients. Contrast-enhanced MR angiography was superior to DSA in the assessment of the distal run-off vessels in five of seven patients. (orig.) [de

  10. Multidetector-row computed tomography for evaluating the branching angle of the celiac artery: a descriptive study

    Directory of Open Access Journals (Sweden)

    Tokue Hiroyuki

    2012-12-01

    Full Text Available Abstract Background We performed this study in order to investigate the shape of the origin of the celiac artery in maximum intensity projection (MIP using routine 64 multidetector-row computed tomography (MDCT data in order to plan for the implantation of an intra-arterial hepatic port system. Methods A total of 1,104 patients with hepatocellular carcinoma were assessed with MDCT. In the definition of the branching angle, the anterior side of the abdominal aorta was considered the baseline, and the cranial and caudal sides were designated as 0 and 180 degrees, respectively. The angles between 0 and 90 degrees and between 90 and 180 degrees from the cranial side were considered upward and downward, respectively, and the branching angle of the celiac artery was classified every 30 degrees. The subclavian arterial route was used for the implantation of an intra-arterial hepatic port system in patients with branching angles of 150 degrees or more (sharp downward. Results The median branching angle was (median ± standard deviation 135 ± 23 (range, 51–174 degrees. The branching was upward in 77 patients (7% and downward in 1,027 patients (93%. The branching was downward with an angle of 120 to150 degrees in most patients (n = 613. The branching was sharply downward with an angle of 150 degrees or more in 177 patients (16%. A total of 10 patients were referred for interventional placement of an intra-arterial hepatic port system. The subclavian arterial route was used for implantation of an intra-arterial hepatic port system in 2 patients with sharp downward branching. Conclusions The branching angle of the celiac artery can be easily determined by the preparation of MIP images from routine MDCT data. MIP may provide useful information for the selection of the catheter insertion route in order to avoid a sharp branching angle of the celiac artery.

  11. Developmental constraints revealed by co-variation within and among molar rows in two murine rodents.

    Science.gov (United States)

    Renaud, Sabrina; Pantalacci, Sophie; Quéré, Jean-Pierre; Laudet, Vincent; Auffray, Jean-Christophe

    2009-01-01

    Morphological integration corresponds to interdependency between characters that can arise from several causes. Proximal causes of integration include that different phenotypic features may share common genetic sets and/or interact during their development. Ultimate causes may be the prolonged effect of selection favoring integration of functionally interacting characters, achieved by the molding of these proximal causes. Strong and direct interactions among successive teeth of a molar row are predicted by genetic and developmental evidences. Functional constraints related to occlusion, however, should have selected more strongly for a morphological integration of occluding teeth and a corresponding evolution of the underlying developmental and genetic pathways. To investigate how these predictions match the patterns of phenotypic integration, we studied the co-variation among the six molars of the murine molar row, focusing on two populations of house mice (Mus musculus domesticus) and wood mice (Apodemus sylvaticus). The size and shape of the three upper and lower molars were quantified and compared. Our results evidenced similar patterns in both species, size being more integrated than shape among all the teeth, and both size and shape co-varying strongly between adjacent teeth, but also between occluding teeth. Strong co-variation within each molar row is in agreement with developmental models showing a cascade influence of the first molar on the subsequent molars. In contrast, the strong co-variation between molars of the occluding tooth rows confirms that functional constraints molded patterns of integration and probably the underlying developmental pathways despite the low level of direct developmental interactions occurring among molar rows. These patterns of co-variation are furthermore conserved between the house mouse and the wood mouse that diverged >10 Ma, suggesting that they may constitute long-running constraints to the diversification of the murine

  12. Present diagnostic strategies for acute pulmonary thromboembolism. Results of a questionnaire in a retrospective trial conducted by the Respiratory Nuclear Medicine Working Group of the Japanese Society of Nuclear Medicine

    International Nuclear Information System (INIS)

    Kawamoto, Masami; Inoue, Tomio; Honda, Norinari; Suga, Kazuyoshi; Imai, Teruhiko

    2002-01-01

    The aim of this study is to re-evaluate and clarify the diagnostic role of ventilation/perfusion lung scintigraphy in Japan, now that single-detector-row helical CT and multidetector-row CT are available in clinical practice. The Respiratory Nuclear Medicine Working Group of the Japanese Society of Nuclear Medicine distributed a questionnaire to institutions in Japan equipped with scintillation cameras as of September 2001. Of 1,222 institutions, 239 returned effective answers (19.6%). The most frequent combination for initial diagnosis of acute pulmonary thromboembolism was chest radiography, perfusion lung scintigraphy, and contrast-enhanced CT (111 institutions, 46.4%). The questionnaire revealed that the validity and usage of perfusion lung scintigraphy and those of contrast-enhanced CT were equivalent in the present clinical situation. On the other hand, the diagnostic value of ventilation lung scintigraphy in suspected pulmonary thromboembolism has not been established in Japan. Even though contrast-enhanced CT is widely used in Japan, perfusion lung scintigraphy is still required to determine disease severity and monitor its progress. (author)

  13. Bi-directional x-ray phase-contrast mammography.

    Directory of Open Access Journals (Sweden)

    Kai Scherer

    Full Text Available Phase-contrast x-ray imaging is a promising improvement of conventional absorption-based mammography for early tumor detection. This potential has been demonstrated recently, utilizing structured gratings to obtain differential phase and dark-field scattering images. However, the inherently anisotropic imaging sensitivity of the proposed mono-directional approach yields only insufficient diagnostic information, and has low diagnostic sensitivity to highly oriented structures. To overcome these limitations, we present a two-directional x-ray phase-contrast mammography approach and demonstrate its advantages by applying it to a freshly dissected, cancerous mastectomy breast specimen. We illustrate that the two-directional scanning procedure overcomes the insufficient diagnostic value of a single scan, and reliably detects tumor structures, independently from their orientation within the breast. Our results indicate the indispensable diagnostic necessity and benefit of a multi-directional approach for x-ray phase-contrast mammography.

  14. Preoperative differentiation between T1a and ≥T1b gallbladder cancer: combined interpretation of high-resolution ultrasound and multidetector-row computed tomography

    International Nuclear Information System (INIS)

    Joo, Ijin; Baek, Jee Hyun; Kim, Jung Hoon; Han, Joon Koo; Choi, Byung Ihn; Lee, Jae Young; Park, Hee Sun

    2014-01-01

    To determine the diagnostic value of combined interpretation of high-resolution ultrasound (HRUS) and multidetector-row computed tomography (MDCT) for preoperative differentiation between T1a and ≥T1b gallbladder (GB) cancer. Eighty-seven patients with pathologically confirmed GB cancers (T1a, n = 15; ≥T1b, n = 72), who preoperatively underwent both HRUS and MDCT, were included in this retrospective study. Two reviewers independently determined the T-stages of the GB cancers on HRUS and MDCT using a five-point confidence scale (5, definitely T1a; 1, definitely ≥T1b). For individual modality interpretation, the lesions with scores ≥4 were classified as T1a, and, for combined modality interpretation, the lesions with all scores ≥4 in both modalities were classified as T1a. The McNemar test was used to compare diagnostic performance. The diagnostic accuracy of differentiation between T1a and ≥T1b GB cancer was higher using combined interpretation (90.8 % and 88.5 % for reviewers 1 and 2, respectively) than individual interpretation of HRUS (82.8 % and 83.9 %) or MDCT (74.7 % and 82.8 %) (P < 0.05, reviewer 1). Combined interpretations demonstrated 100 % specificity for both reviewers, which was significantly higher than individual interpretations (P < 0.05, both reviewers). Combined HRUS and MDCT interpretation may improve the diagnostic accuracy and specificity for differentiating between T1a and ≥T1b GB cancers. circle Differentiating between T1a and ≥T1b gallbladder cancer can help surgical planning. (orig.)

  15. Strong enhancement of streaming current power by application of two phase flow

    NARCIS (Netherlands)

    Xie, Yanbo; Sherwood, John D.; Shui, Lingling; van den Berg, Albert; Eijkel, Jan C.T.

    2011-01-01

    We show that the performance of a streaming-potential based microfluidic energy conversion system can be strongly en-hanced by the use of two phase flow. In single-phase systems, the internal conduction current induced by the streaming poten-tial limits the output power, while in a two-phase system

  16. Contrast Dose and Radiation Dose Reduction in Abdominal Enhanced Computerized Tomography Scans with Single-phase Dual-energy Spectral Computerized Tomography Mode for Children with Solid Tumors.

    Science.gov (United States)

    Yu, Tong; Gao, Jun; Liu, Zhi-Min; Zhang, Qi-Feng; Liu, Yong; Jiang, Ling; Peng, Yun

    2017-04-05

    Contrast dose and radiation dose reduction in computerized tomography (CT) scan for adult has been explored successfully, but there have been few studies on the application of low-concentration contrast in pediatric abdominal CT examinations. This was a feasibility study on the use of dual-energy spectral imaging and adaptive statistical iterative reconstruction (ASiR) for the reduction of radiation dose and iodine contrast dose in pediatric abdominal CT patients with solid tumors. Forty-five patients with solid tumors who had initial CT (Group B) and follow-up CT (Group A) after chemotherapy were enrolled. The initial diagnostic CT scan (Group B) was performed using the standard two-phase enhanced CT with 320 mgI/ml concentration contrast, and the follow-up scan (Group A) was performed using a single-phase enhanced CT at 45 s after the beginning of the 270 mgI/ml contrast injection using spectral mode. Forty percent ASiR was used for the images in Group B and monochromatic images with energy levels ≥60 keV in Group A. In addition, filtered back-projection (FBP) reconstruction was used for monochromatic images hounsfield unit (HU). The abdominal organs of Groups A and B had similar degrees of absolute and relative enhancement (t = 0.36 and -1.716 for liver, -0.153 and -1.546 for pancreas, and 2.427 and 0.866 for renal cortex, all P> 0.05). Signal-to-noise ratio of the abdominal organs was significantly lower in Group A than in Group B (t = -8.11 for liver, -7.83 for pancreas, and -5.38 for renal cortex, all P 3, indicating clinically acceptable image quality. Single-phase, dual-energy spectral CT used for children with solid abdominal tumors can reduce contrast dose and radiation dose and can also maintain clinically acceptable image quality.

  17. Phase-contrast tomographic imaging using an X-ray interferometer

    Energy Technology Data Exchange (ETDEWEB)

    Momose, A. [Hitachi Ltd, Advanced Research Lab., Saitama (Japan); Takeda, T.; Itai, Y. [Univ. of Tsukuba, Inst. of Clinical Medicine, Ibaraki (Japan); Yoneyama, A. [Hitachi Ltd, Central Resarch Lab., Tokyo (Japan); Hirano, K. [High Energy Accelerator Research Organization, Inst. of Materials Structure Science, Ibaraki (Japan)

    1998-05-01

    Apparatus for phase-contrast X-ray computed tomography using a monolithic X-ray interferometer is presented with some observational results for human breast tissues. Structures characteristic of the tissues were revealed in the phase-contrast tomograms. The procedure of image analysis consists of phase retrieval from X-ray interference patterns and tomographic image reconstruction from the retrieved phase shift. Next, feasibility of phase-contrast imaging using a two-crystal X-ray interferometer was studied aiming at in vivo observation in the future. In a preliminary study, the two-crystal X-ray interferometer was capable of generating fringes of 70% visibility using synchrotron X-rays. 35 refs.

  18. Phase-contrast tomographic imaging using an X-ray interferometer

    International Nuclear Information System (INIS)

    Momose, A.; Takeda, T.; Itai, Y.; Yoneyama, A.; Hirano, K.

    1998-01-01

    Apparatus for phase-contrast X-ray computed tomography using a monolithic X-ray interferometer is presented with some observational results for human breast tissues. Structures characteristic of the tissues were revealed in the phase-contrast tomograms. The procedure of image analysis consists of phase retrieval from X-ray interference patterns and tomographic image reconstruction from the retrieved phase shift. Next, feasibility of phase-contrast imaging using a two-crystal X-ray interferometer was studied aiming at in vivo observation in the future. In a preliminary study, the two-crystal X-ray interferometer was capable of generating fringes of 70% visibility using synchrotron X-rays

  19. In silico optimization of phase-change materials for digital memories: a survey of first-row transition-metal dopants for Ge₂Sb₂Te₅.

    Science.gov (United States)

    Skelton, J M; Elliott, S R

    2013-05-22

    Phase-change materials are the alloys at the heart of an emerging class of next-generation, non-volatile digital memory technologies. However, the widely studied Ge-Sb-Te system possesses several undesirable properties, and enhancing its properties, e.g. by doping, is an area of active research. Various first-row transition-metal dopants have been shown to impart useful property enhancements, but a systematic study of the entire period has yet to be undertaken, and little has been done to investigate their interaction with the host material at the atomic level. We have carried out first-principles computer simulations of the complete phase-change cycle in Ge2Sb2Te5 doped with each of the ten first-row transition metals. In this article, we present a comprehensive survey of the electronic, magnetic and optical properties of these doped materials. We discuss in detail their atomic-level structure, and relate the microscopic behaviours of the dopant atoms to their influence on the Ge2Sb2Te5 host. By considering an entire family of similar materials, we identify trends and patterns which might be used to predict suitable dopants for optimizing materials for specific phase-change applications. The computational method employed here is general, and this materials-discovery approach could be applied in the future to study other families of potential dopants for such materials.

  20. Multidetector CT angiography in living donor renal transplantation: accuracy and discrepancies in right venous anatomy.

    Science.gov (United States)

    Kulkarni, S; Emre, S; Arvelakis, A; Asch, W; Bia, M; Formica, R; Israel, G

    2011-01-01

    Multidetector computed tomography (MDCT) angiography is a reliable technique for assessing pre-operative renal anatomy in living kidney donors. The method has largely evolved into protocols that eliminate dedicated venous phase and instead utilize a combined arterial/venous phase to delineate arterial and venous anatomy simultaneously. Despite adoption of this protocol, there has been no study to assess its accuracy. To assess whether or not MDCT angiography compares favorably to intra-operative findings, 102 donors underwent MDCT angiography without a dedicated venous phase with surgical interpretation of renal anatomy. Anatomical variants included multiple arteries (12%), multiple veins (7%), early arterial bifurcation (13%), late venous confluence (5%), circumaortic renal veins (5%), retroaortic vein (1%), and ureteral duplication (2%). The sensitivity and specificity of multiple arterial anomalies were 100% and 97%, respectively. The sensitivity and specificity of multiple venous anomalies were 92% and 98%, respectively. The most common discrepancy was noted exclusively in the interpretation of right venous anatomy as it pertained to the renal vein/vena cava confluence (3%). MDCT angiography using a combined arterial/venous contrast-enhanced phase provides suitable depiction of renal donor anatomy. Careful consideration should be given when planning a right donor nephrectomy whether the radiographic interpretation is suggestive of a late confluence. © 2010 John Wiley & Sons A/S.

  1. Comparison of neuroendocrine tumor detection and characterization using DOTATOC-PET in correlation with contrast enhanced CT and delayed contrast enhanced MRI

    International Nuclear Information System (INIS)

    Giesel, F.L.; Kratochwil, C.; Mehndiratta, A.; Wulfert, S.; Moltz, J.H.; Zechmann, C.M.; Kauczor, H.U.; Haberkorn, U.; Ley, S.

    2012-01-01

    Purpose: We evaluated the rate of successful characterization of gastroenteropancreatic neuroendocrine tumors (NETs) present with an increased somatostatin receptor, comparing CE-CT with CE-MRI, each in correlation with DOTATOC-PET. Methods and materials: 8 patients with GEP-NET were imaged using CE-MRI (Gd-EOB-DTPA), CE-CT (Imeron 400) and DOTATOC-PET. Contrast-enhancement of normal liver-tissue and metastasis was quantified with ROI-technique. Tumor delineation was assessed with visual-score in blind-read-analysis by two experienced radiologists. Results: Out of 40 liver metastases in patients with NETs, all were detected by CE-MRI and the lesion extent could be adequately assessed, whereas CT failed to detect 20% of all metastases. The blind-read-score of CT in arterial and portal phase was median −0.65 and −1.4, respectively, and 2.7 for delayed-MRI. The quantitative ROI-analysis presented an improved contrast-enhancement-ratio with a median of 1.2, 1.6 and 3.3 for CE-CT arterial, portal-phase and delayed-MRI respectively. Conclusion: Late CE-MRI was superior to CE-CT in providing additionally morphologic characterization and exact lesion extension of hepatic metastases from neuroendocrine tumor detected with DOTATOC-PET. Therefore, late enhanced Gd-EOB-DTPA-MRI seems to be the adequate imaging modality for combination with DOTATOC-PET to provide complementary (macroscopic and molecular) tumor characterization in hepatic metastasized NETs

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-04-15

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

  3. Technique for arterial-phase contrast-enhanced three-dimensional MR angiography of the carotid and vertebral arteries.

    Science.gov (United States)

    Isoda, H; Takehara, Y; Isogai, S; Takeda, H; Kaneko, M; Nozaki, A; Sun, Y; Foo, T K

    1998-08-01

    Our goal was to evaluate whether contrast-enhanced three-dimensional MR angiography using the MR Smartprep technique would enable us to obtain arterial-phase MR angiograms of the carotid and vertebral arteries. The study included 35 patients with suspected lesions of the neck in whom the MR Smartprep technique was used for MR angiography performed with a 1.5-T superconducting system. The tracker volume was placed primarily in the middle part of the right common carotid artery. The imaging volume was placed in a coronal direction to include the carotid and vertebral arteries from the aortic arch to the skull base. A centric phase-ordering scheme was used. Imaging times were 20 to 38 seconds for 14 patients and 11 to 16 seconds for 21 patients. By using a smaller tracker volume and an imaging time of less than 16 seconds, we were able to achieve a 100% successful triggering rate and to delineate selectively arterial-phase carotid and vertebral arteries with almost no venous contamination. Contract-enhanced 3-D MR angiography with the MR Smartprep technique was useful for showing arterial-phase carotid and vertebral arteries selectively.

  4. 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)

  5. Phase contrast STEM for thin samples: Integrated differential phase contrast

    International Nuclear Information System (INIS)

    Lazić, Ivan; Bosch, Eric G.T.; Lazar, Sorin

    2016-01-01

    It has been known since the 1970s that the movement of the center of mass (COM) of a convergent beam electron diffraction (CBED) pattern is linearly related to the (projected) electrical field in the sample. We re-derive a contrast transfer function (CTF) for a scanning transmission electron microscopy (STEM) imaging technique based on this movement from the point of view of image formation and continue by performing a two-dimensional integration on the two images based on the two components of the COM movement. The resulting integrated COM (iCOM) STEM technique yields a scalar image that is linear in the phase shift caused by the sample and therefore also in the local (projected) electrostatic potential field of a thin sample. We confirm that the differential phase contrast (DPC) STEM technique using a segmented detector with 4 quadrants (4Q) yields a good approximation for the COM movement. Performing a two-dimensional integration, just as for the COM, we obtain an integrated DPC (iDPC) image which is approximately linear in the phase of the sample. Beside deriving the CTFs of iCOM and iDPC, we clearly point out the objects of the two corresponding imaging techniques, and highlight the differences to objects corresponding to COM-, DPC-, and (HA) ADF-STEM. The theory is validated with simulations and we present first experimental results of the iDPC-STEM technique showing its capability for imaging both light and heavy elements with atomic resolution and a good signal to noise ratio (SNR). - Highlights: • First DPC-based atomic resolution images of potential and charge density are obtained. • This is enabled by integration and differentiation of 2D DPC signals, respectively. • Integrated DPC (iDPC) based on 4 quadrant imaging is compared to iCOM imaging. • Noise analysis and comparison with standard STEM imaging modes is provided. • iDPC allows direct imaging of light (C, N, O …) and heavy (Ga, Au …) atoms together.

  6. Phase contrast STEM for thin samples: Integrated differential phase contrast

    Energy Technology Data Exchange (ETDEWEB)

    Lazić, Ivan, E-mail: ivan.lazic@fei.com; Bosch, Eric G.T.; Lazar, Sorin

    2016-01-15

    It has been known since the 1970s that the movement of the center of mass (COM) of a convergent beam electron diffraction (CBED) pattern is linearly related to the (projected) electrical field in the sample. We re-derive a contrast transfer function (CTF) for a scanning transmission electron microscopy (STEM) imaging technique based on this movement from the point of view of image formation and continue by performing a two-dimensional integration on the two images based on the two components of the COM movement. The resulting integrated COM (iCOM) STEM technique yields a scalar image that is linear in the phase shift caused by the sample and therefore also in the local (projected) electrostatic potential field of a thin sample. We confirm that the differential phase contrast (DPC) STEM technique using a segmented detector with 4 quadrants (4Q) yields a good approximation for the COM movement. Performing a two-dimensional integration, just as for the COM, we obtain an integrated DPC (iDPC) image which is approximately linear in the phase of the sample. Beside deriving the CTFs of iCOM and iDPC, we clearly point out the objects of the two corresponding imaging techniques, and highlight the differences to objects corresponding to COM-, DPC-, and (HA) ADF-STEM. The theory is validated with simulations and we present first experimental results of the iDPC-STEM technique showing its capability for imaging both light and heavy elements with atomic resolution and a good signal to noise ratio (SNR). - Highlights: • First DPC-based atomic resolution images of potential and charge density are obtained. • This is enabled by integration and differentiation of 2D DPC signals, respectively. • Integrated DPC (iDPC) based on 4 quadrant imaging is compared to iCOM imaging. • Noise analysis and comparison with standard STEM imaging modes is provided. • iDPC allows direct imaging of light (C, N, O …) and heavy (Ga, Au …) atoms together.

  7. Contrast enhancement in an optical time-domain reflectometer via self-phase modulation compensation by chirped probe pulses

    International Nuclear Information System (INIS)

    Alekseev, A E; Potapov, V T; Vdovenko, V S; Simikin, D E; Gorshkov, B G

    2016-01-01

    In the present paper we propose a novel method for optical time-domain reflectometer (OTDR)–reflectogram contrast enhancement via compensation of nonlinear distortions of propagating probe pulse, which arise due to the self-phase modulation (SPM) effect in optical fiber. The compensation is performed via preliminary frequency modulation (chirp) of the initial probe pulse according to the specific law. As a result the OTDR contrast at some distant predefined fiber point is fully restored to the value of non-distorted probe pulse at the beginning of the fiber line. As a result, the performance of the phase OTDR increases. The point of full SPM compensation could be shifted to any other point of the fiber line via preliminary frequency modulation index change. The feasibility of the proposed method is theoretically proved and experimentally demonstrated. (paper)

  8. Missed rib fractures on evaluation of initial chest CT for trauma patients: pattern analysis and diagnostic value of coronal multiplanar reconstruction images with multidetector row CT.

    Science.gov (United States)

    Cho, S H; Sung, Y M; Kim, M S

    2012-10-01

    The objective of this study was to review the prevalence and radiological features of rib fractures missed on initial chest CT evaluation, and to examine the diagnostic value of additional coronal images in a large series of trauma patients. 130 patients who presented to an emergency room for blunt chest trauma underwent multidetector row CT of the thorax within the first hour during their stay, and had follow-up CT or bone scans as diagnostic gold standards. Images were evaluated on two separate occasions: once with axial images and once with both axial and coronal images. The detection rates of missed rib fractures were compared between readings using a non-parametric method of clustered data. In the cases of missed rib fractures, the shapes, locations and associated fractures were evaluated. 58 rib fractures were missed with axial images only and 52 were missed with both axial and coronal images (p=0.088). The most common shape of missed rib fractures was buckled (56.9%), and the anterior arc (55.2%) was most commonly involved. 21 (36.2%) missed rib fractures had combined fractures on the same ribs, and 38 (65.5%) were accompanied by fracture on neighbouring ribs. Missed rib fractures are not uncommon, and radiologists should be familiar with buckle fractures, which are frequently missed. Additional coronal imagescan be helpful in the diagnosis of rib fractures that are not seen on axial images.

  9. 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.

  10. 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.

  11. The Incidence and Anatomy of Accessory Pudendal Arteries as Depicted on Multidetector-Row CT Angiography: Clinical Implications of Preoperative Evaluation for Laparoscopic and Robot-Assisted Radical Prostatectomy

    International Nuclear Information System (INIS)

    Park, Beom Jin; Sung, Deuk Jae; Kim, Min Ju; Cho, Sung Bum; Kim, Yun Hwan; Chung, Kyoo Byung; Kang, Seok Ho; Cheon, Jun

    2009-01-01

    To help preserve accessory pudendal arteries (APAs) and to ensure optimal postoperative sexual function after a laparoscopic or robot-assisted radical prostatectomy, we have evaluated the incidence of APAs as detected on multidetector-row CT (MDCT) angiography and have provided a detailed anatomical description. The distribution of APAs was evaluated in 121 consecutive male patients between February 2006 and July 2007 who underwent 64- channel MDCT angiography of the lower extremities. We defined an APA as any artery located within the periprostatic region running parallel to the dorsal vascular complex. We also subclassified APAs into lateral and apical APAs. Two radiologists retrospectively evaluated the origin, course and number of APAs; the final APA subclassification based on MDCT angiography source data was determined by consensus. We identified 44 APAs in 36 of 121 patients (30%). Two distinct varieties of APAs were identified. Thirty-three APAs (75%) coursed near the anterolateral region of the prostatic apex, termed apical APAs. The remaining 11 APAs (25%) coursed along the lateral aspect of the prostate, termed lateral APAs. All APAs originated from the internal obturator artery and iliac artery or a branch of the iliac artery such as the inferior vesical artery. The majority of apical APAs arose from the internal obturator artery (84%). Seven patients (19%) had multiple APAs. APAs are more frequently detected by the use of MDCT angiography than as suggested by previous surgical studies. The identification of APAs on MDCT angiography may provide useful information for the surgical preservation of APAs during a laparoscopic or robot-assisted radical prostatectomy

  12. X-ray elastography: Modification of x-ray phase contrast images using ultrasonic radiation pressure

    International Nuclear Information System (INIS)

    Hamilton, Theron J.; Bailat, Claude; Rose-Petruck, Christoph; Diebold, Gerald J.; Gehring, Stephan; Laperle, Christopher M.; Wands, Jack

    2009-01-01

    The high resolution characteristic of in-line x-ray phase contrast imaging can be used in conjunction with directed ultrasound to detect small displacements in soft tissue generated by differential acoustic radiation pressure. The imaging method is based on subtraction of two x-ray images, the first image taken with, and the second taken without the presence of ultrasound. The subtraction enhances phase contrast features and, to a large extent, removes absorption contrast so that differential movement of tissues with different acoustic impedances or relative ultrasonic absorption is highlighted in the image. Interfacial features of objects with differing densities are delineated in the image as a result of both the displacement introduced by the ultrasound and the inherent sensitivity of x-ray phase contrast imaging to density variations. Experiments with ex vivo murine tumors and human tumor phantoms point out a diagnostic capability of the method for identifying tumors.

  13. Generalized image contrast enhancement technique based on Heinemann contrast discrimination model

    Science.gov (United States)

    Liu, Hong; Nodine, Calvin F.

    1994-03-01

    This paper presents a generalized image contrast enhancement technique which equalizes perceived brightness based on the Heinemann contrast discrimination model. This is a modified algorithm which presents an improvement over the previous study by Mokrane in its mathematically proven existence of a unique solution and in its easily tunable parameterization. The model uses a log-log representation of contrast luminosity between targets and the surround in a fixed luminosity background setting. The algorithm consists of two nonlinear gray-scale mapping functions which have seven parameters, two of which are adjustable Heinemann constants. Another parameter is the background gray level. The remaining four parameters are nonlinear functions of gray scale distribution of the image, and can be uniquely determined once the previous three are given. Tests have been carried out to examine the effectiveness of the algorithm for increasing the overall contrast of images. It can be demonstrated that the generalized algorithm provides better contrast enhancement than histogram equalization. In fact, the histogram equalization technique is a special case of the proposed mapping.

  14. Generalized image contrast enhancement technique based on the Heinemann contrast discrimination model

    Science.gov (United States)

    Liu, Hong; Nodine, Calvin F.

    1996-07-01

    This paper presents a generalized image contrast enhancement technique, which equalizes the perceived brightness distribution based on the Heinemann contrast discrimination model. It is based on the mathematically proven existence of a unique solution to a nonlinear equation, and is formulated with easily tunable parameters. The model uses a two-step log-log representation of luminance contrast between targets and surround in a luminous background setting. The algorithm consists of two nonlinear gray scale mapping functions that have seven parameters, two of which are adjustable Heinemann constants. Another parameter is the background gray level. The remaining four parameters are nonlinear functions of the gray-level distribution of the given image, and can be uniquely determined once the previous three are set. Tests have been carried out to demonstrate the effectiveness of the algorithm for increasing the overall contrast of radiology images. The traditional histogram equalization can be reinterpreted as an image enhancement technique based on the knowledge of human contrast perception. In fact, it is a special case of the proposed algorithm.

  15. High-dose contrast-enhanced MRI in multiple sclerosis

    International Nuclear Information System (INIS)

    Koudriavtseva, T.; Pozzilli, C.; Di Biasi, C.; Iannilli, M.; Trasimeni, G.; Gasperini, C.; Argentino, C.; Gualdi, G.F.

    1996-01-01

    Contrast-enhanced MRI is effective for assessing disease activity in multiple sclerosis (MS) and may provide an outcome measure for testing the efficacy of treatment in clinical trials. To compare the sensitivity of high-dose gadolinium-HP-DO3A with that of a standard dose of gadolinium-DTPA, we studied 16 patients with relapsing-remitting MS in the acute phase of the disease. Each underwent two MRI examinations within at most 48 h. The initial MRI study was with a standard dose of gadolinium-DTPA (0.1 mmol/kg), and the second one an experimental dose of gadolinium-HP-DO3A (0.3 mmol/kg). No adverse effects were attributed to the contrast media. The high-dose study revealed more enhancing lesions than the standard-dose study (56 vs 38). This difference was found to be more relevant for infratentorial and small lesions. Furthermore, with the higher dose, there was a marked qualitative improvement in the visibility and delineation of the lesions. (orig.). With 4 figs., 2 tabs

  16. High-dose contrast-enhanced MRI in multiple sclerosis

    Energy Technology Data Exchange (ETDEWEB)

    Koudriavtseva, T. [Department of Neurosciences, University of Rome ``La Sapienza`` Rome (Italy); Pozzilli, C. [Department of Neurosciences, University of Rome ``La Sapienza`` Rome (Italy); Di Biasi, C. [MR Unit, Clinica Medica 1, University of Rome ``La Sapienza``, Rome (Italy); Iannilli, M. [MR Unit, Clinica Medica 1, University of Rome ``La Sapienza``, Rome (Italy); Trasimeni, G. [MR Unit, Clinica Medica 1, University of Rome ``La Sapienza``, Rome (Italy); Gasperini, C. [Department of Neurosciences, University of Rome ``La Sapienza`` Rome (Italy); Argentino, C. [Department of Neurosciences, University of Rome ``La Sapienza`` Rome (Italy); Gualdi, G.F. [MR Unit, Clinica Medica 1, University of Rome ``La Sapienza``, Rome (Italy)

    1996-05-01

    Contrast-enhanced MRI is effective for assessing disease activity in multiple sclerosis (MS) and may provide an outcome measure for testing the efficacy of treatment in clinical trials. To compare the sensitivity of high-dose gadolinium-HP-DO3A with that of a standard dose of gadolinium-DTPA, we studied 16 patients with relapsing-remitting MS in the acute phase of the disease. Each underwent two MRI examinations within at most 48 h. The initial MRI study was with a standard dose of gadolinium-DTPA (0.1 mmol/kg), and the second one an experimental dose of gadolinium-HP-DO3A (0.3 mmol/kg). No adverse effects were attributed to the contrast media. The high-dose study revealed more enhancing lesions than the standard-dose study (56 vs 38). This difference was found to be more relevant for infratentorial and small lesions. Furthermore, with the higher dose, there was a marked qualitative improvement in the visibility and delineation of the lesions. (orig.). With 4 figs., 2 tabs.

  17. Clinical evaluation of contrast-enhanced digital mammography and contrast enhanced tomosynthesis--Comparison to contrast-enhanced breast MRI.

    Science.gov (United States)

    Chou, Chen-Pin; Lewin, John M; Chiang, Chia-Ling; Hung, Bao-Hui; Yang, Tsung-Lung; Huang, Jer-Shyung; Liao, Jia-Bin; Pan, Huay-Ben

    2015-12-01

    To compare the diagnostic accuracy of contrast-enhanced digital mammography (CEDM) and contrast-enhanced tomosynthesis (CET) to dynamic contrast enhanced breast MRI (DCE-MRI) using a multireader-multicase study. Institutional review board approval and informed consents were obtained. Total 185 patients (mean age 51.3) with BI-RADS 4 or 5 lesions were evaluated before biopsy with mammography, tomosynthesis, CEDM, CET and DCE-MRI. Mediolateral-oblique and cranio-caudal views of the target breast CEDM and CET were acquired at 2 and 4 min after contrast agent injection. A mediolateral-oblique view of the non-target breast was taken at 6 min. Each lesion was scored with forced BI-RADS categories by three readers. Each reader interpreted lesions in the following order: mammography, tomosynthesis, CEDM, CET, and DCE-MRI during a single reading session. Histology showed 81 cancers and 144 benign lesions in the study. Of the 81 malignant lesions, 44% (36/81) were invasive and 56% (45/81) were non-invasive. Areas under the ROC curve, averaged for the 3 readers, were as follows: 0.897 for DCE-MRI, 0.892 for CET, 0.878 for CEDM, 0.784 for tomosynthesis and 0.740 for mammography. Significant differences in AUC were found between the group of contrast enhanced modalities (CEDM, CET, DCE-MRI) and the unenhanced modalities (all p0.05). CET and CEDM may be considered as an alternative modality to MRI for following up women with abnormal mammography. All three contrast modalities were superior in accuracy to conventional digital mammography with or without tomosynthesis. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  18. The Effect of the Degree of Luminal Contrast-Enhancement on CT Measurement of Plaque Size: A Comparison with T1-weighted Magnetic Resonance Imaging

    International Nuclear Information System (INIS)

    Choi, Byoung Wook; Hur, Jin; Lee, Hye Jeong; Kim, Young Jin; Choe, Kyu Ok; Kim, Tae Hoon

    2010-01-01

    We studied early and delayed contrast-enhanced CT to determine the effects of the degree of luminal enhancement on the measurement of plaque size compared to T1-weighted MRI. T1-weighted MRI and a two-phase contrast-enhanced CT was performed in 5 New Zealand white rabbits with atherosclerosis. Early-phase images were acquired during an expected peak enhancement period of the lumen; delayed-phase images were acquired 240 sec after administration of the contrast media. Anteroposterior and lateral luminal diameters (APD, LD), luminal area (LA), total vessel area (TVA), and plaque area (PA) of the aorta were measured on MRI and CT, respectively and compared to each other. A total of 78 slices of the aorta were analyzed. PA, measured on T1-weighted MR images, was significantly greater than PA for both early-phase and delayed-phase CT (p 2 (p 2 (p 2 (p = 0.159) for MRI vs. early-phase CT, MRI vs. delayed-phase CT, and early-phase CT vs. delayed-phase CT, respectively. Different luminal densities by contrast enhancement do not affect the CT measurement of plaque area for the detection of obstructive coronary artery disease

  19. The use of contrast-enhanced post Mortem CT in the detection of cardiovascular deaths.

    Directory of Open Access Journals (Sweden)

    Jonas Christoph Apitzsch

    Full Text Available OBJECTIVES: To evaluate the diagnostic value of contrast enhanced post mortem computed tomography (PMCT in comparison to non-enhanced post mortem CT in the detection of cardiovascular causes of death (COD. BACKGROUND: As autopsy rates decline, new methods to determine CODs are necessary. So contrast enhanced PMCT shall be evaluated in comparison to established non-enhanced PMCT in order to further improve the method. METHODS: In a prospective study, 20 corpses were examined using a 64-row multisclice CT (MSCT before and after intraarterial perfusion with a newly developed, barium-bearing contrast agent and ventilation of the lungs. The cause of death was determined in enhanced and unenhanced scans and a level of confidence (LOC was given by three experienced radiologists on a scale between 0 and 4. Results were compared to autopsy results as gold standard. Autopsy was performed blinded to PMCT-findings. RESULTS: The method allowed visualization of different types of cause of death. There was a significant improvement in LOC in enhanced scans compared to unenhanced scans as well as an improvement in the detection of COD. The cause of death could be determined in 19 out of 20 patients. CONCLUSIONS: PMCT is feasible and appears to be robust for diagnosing cardiovascular causes of death. When compared with unenhanced post-mortem CT intraarterial perfusion and pulmonary ventilation significantly improve visualization and diagnostic accuracy. These promising results warrant further studies.

  20. Contrast between hypervascularized liver lesions and hepatic parenchyma. Early dynamic PET versus contrast-enhanced CT

    International Nuclear Information System (INIS)

    Freesmeyer, M.; Winkens, T.; Schierz, J.-H.

    2014-01-01

    To detect hypervascularized liver lesions, early dynamic (ED) 18 F-FDG PET may be an alternative when contrast-enhanced (CE) imaging is infeasible. This retrospective pilot analysis compared contrast between such lesions and liver parenchyma, an important objective image quality variable, in ED PET versus CE CT. Twenty-eight hypervascularized liver lesions detected by CE CT [21 (75%) hepatocellular carcinomas; mean (range) diameter 4.9 ± 3.5 (1-14) cm] in 20 patients were scanned with ED PET. Using regions of interest, maximum and mean lesional and parenchymal signals at baseline, arterial and venous phases were calculated for ED PET and CE CT. Lesional/parenchymal signal ratio was significantly higher (P < 0.005) with ED PET versus CE CT at the arterial phase and similar between the methods at the venous phase. In liver imaging, ED PET generates greater lesional-parenchymal contrast during the arterial phase than does CE CT; these observations should be formally, prospectively evaluated. (author)

  1. Phase contrast image segmentation using a Laue analyser crystal

    International Nuclear Information System (INIS)

    Kitchen, Marcus J; Paganin, David M; Lewis, Robert A; Pavlov, Konstantin M; Uesugi, Kentaro; Allison, Beth J; Hooper, Stuart B

    2011-01-01

    Dual-energy x-ray imaging is a powerful tool enabling two-component samples to be separated into their constituent objects from two-dimensional images. Phase contrast x-ray imaging can render the boundaries between media of differing refractive indices visible, despite them having similar attenuation properties; this is important for imaging biological soft tissues. We have used a Laue analyser crystal and a monochromatic x-ray source to combine the benefits of both techniques. The Laue analyser creates two distinct phase contrast images that can be simultaneously acquired on a high-resolution detector. These images can be combined to separate the effects of x-ray phase, absorption and scattering and, using the known complex refractive indices of the sample, to quantitatively segment its component materials. We have successfully validated this phase contrast image segmentation (PCIS) using a two-component phantom, containing an iodinated contrast agent, and have also separated the lungs and ribcage in images of a mouse thorax. Simultaneous image acquisition has enabled us to perform functional segmentation of the mouse thorax throughout the respiratory cycle during mechanical ventilation.

  2. Evaluation of pituitary adenomas by multidirectional multislice dynamic CT

    International Nuclear Information System (INIS)

    Abe, T.; Izumiyama, H.; Fujisawa, I.

    2002-01-01

    Purpose: Multidetector-row CT is a new technology with a short scanning time. Multislice dynamic CT (MSDCT) in various directions can be obtained using the multidetector-row CT with multiplanar reformatting (MPR) technique. Material and Methods: We evaluated the initial results of sagittal and coronal MSDCT images reconstructed by MPR (MSDCT-MPR) in 3 pituitary adenoma patients with a pacemaker. Results: In a patient with microadenoma, the maximum contrast between the normal anterior pituitary gland and the adenoma occurred approximately 50 s after the start of the contrast medium injection. A microadenoma was depicted as a less enhanced area relative to normal pituitary tissue. The macroadenomas were depicted as a less enhanced mass with cavernous sinus invasion in 1 patient and as a non-uniformly enhanced mass in another patient. Bone destruction and incomplete opening of the sellar floor during previous surgery were clearly detected in 2 patients with macroadenomas. These pituitary adenomas were removed via the transnasal route based on information from the MSDCT-MPR images only. The findings were verified surgically. Conclusion: The MSDCT-MPR provided the information needed for surgery with good image quality in the 3 patients with pacemakers. MSDCT-MPR appears to be a useful technique for patients with a pituitary adenoma in whom MR imaging is not available. This is the first report, to our knowledge, of the MSDCT-MPR technique being used to demonstrate pituitary disorders

  3. Evaluation of pituitary adenomas by multidirectional multislice dynamic CT

    Energy Technology Data Exchange (ETDEWEB)

    Abe, T.; Izumiyama, H. [Showa Univ. School of Medicine, Tokyo (Japan). Dept. of Neurosurgery; Fujisawa, I. [Kishiwada City Hospital, Kishiwada (Japan). Dept. of Radiology

    2002-11-01

    Purpose: Multidetector-row CT is a new technology with a short scanning time. Multislice dynamic CT (MSDCT) in various directions can be obtained using the multidetector-row CT with multiplanar reformatting (MPR) technique. Material and Methods: We evaluated the initial results of sagittal and coronal MSDCT images reconstructed by MPR (MSDCT-MPR) in 3 pituitary adenoma patients with a pacemaker. Results: In a patient with microadenoma, the maximum contrast between the normal anterior pituitary gland and the adenoma occurred approximately 50 s after the start of the contrast medium injection. A microadenoma was depicted as a less enhanced area relative to normal pituitary tissue. The macroadenomas were depicted as a less enhanced mass with cavernous sinus invasion in 1 patient and as a non-uniformly enhanced mass in another patient. Bone destruction and incomplete opening of the sellar floor during previous surgery were clearly detected in 2 patients with macroadenomas. These pituitary adenomas were removed via the transnasal route based on information from the MSDCT-MPR images only. The findings were verified surgically. Conclusion: The MSDCT-MPR provided the information needed for surgery with good image quality in the 3 patients with pacemakers. MSDCT-MPR appears to be a useful technique for patients with a pituitary adenoma in whom MR imaging is not available. This is the first report, to our knowledge, of the MSDCT-MPR technique being used to demonstrate pituitary disorders.

  4. Contrast enhancement by differently sized paramagnetic MRI contrast agents in mice with two phenotypes of atherosclerotic plaque

    NARCIS (Netherlands)

    van Bochove, Glenda S.; Paulis, Leonie E. M.; Segers, Dolf; Mulder, Willem J. M.; Krams, Rob; Nicolay, Klaas; Strijkers, Gustav J.

    2011-01-01

    Interest in the use of contrast-enhanced MRI to enable in vivo specific characterization of atherosclerotic plaques is increasing. In this study the intrinsic ability of three differently sized gadolinium-based contrast agents to permeate different mouse plaque phenotypes was evaluated with MRI. A

  5. Analyzer-based x-ray phase-contrast microscopy combining channel-cut and asymmetrically cut crystals

    International Nuclear Information System (INIS)

    Hoennicke, M. G.; Cusatis, C.

    2007-01-01

    An analyzer-based x-ray phase-contrast microscopy (ABM) setup combining a standard analyzer-based x-ray phase-contrast imaging (ABI) setup [nondispersive 4-crystal setup (Bonse-Hart setup)] and diffraction by asymmetrically cut crystals is presented here. An attenuation-contrast microscopy setup with conventional x-ray source and asymmetrically cut crystals is first analyzed. Edge-enhanced effects attributed to phase jumps or refraction/total external reflection on the fiber borders were detected. However, the long exposure times and the possibility to achieve high contrast microscopies by using extremely low attenuation-contrast samples motivated us to assemble the ABM setup using a synchrotron source. This setup was found to be useful for low contrast attenuation samples due to the low exposure time, high contrast, and spatial resolution found. Moreover, thanks to the combination with the nondispersive ABI setup, the diffraction-enhanced x-ray imaging algorithm could be applied

  6. Fungal Distribution and Varieties Resistance to Kernel Discoloration in Korean Two-rowed Barley

    OpenAIRE

    Sang-Hyun Shin; Eun-Jo Seo; Jae-Seong Choi; JungKwan Lee; Jong-Chul Park; Chun-Sik Kang

    2013-01-01

    Barley kernel discoloration (KD) leads to substantial loss in value through downgrading and discounting of malting barley. The objective of this research is to investigate fungal distribution and varieties resistance to KD in Korean two-rowed barley. Several fungal organisms including Alternaria spp., Fusarium spp., Aspergillus spp., Epicoccum spp. and Rhizopus spp. were isolated from Korean two-rowed barley representing KD. The symptoms of KD were brown and black discolorations o...

  7. Patent foramen ovale: diagnosis with multidetector CT--comparison with transesophageal echocardiography.

    Science.gov (United States)

    Kim, Young Jin; Hur, Jin; Shim, Chi-Young; Lee, Hye-Jeong; Ha, Jong-Won; Choe, Kyu Ok; Heo, Ji Hoe; Choi, Eui-Young; Choi, Byoung Wook

    2009-01-01

    To evaluate the clinical feasibility and accuracy of 64-section multidetector computed tomography (CT) compared with transesophageal echocardiography (TEE) for diagnosis of a patent foramen ovale (PFO). Institutional review board approval was obtained for this retrospective study. The study included 152 consecutive stroke patients (mean age, 61.7 years; 98 men, 54 women) who underwent both cardiac multidetector CT and TEE. Electrocardiographically gated cardiac CT was performed with a 64-section CT scanner by using a saline-chaser contrast agent injection technique. A contrast agent jet from the contrast agent-filled left atrium (LA) to the saline-filled right atrium (RA) and channel-like appearance of the interatrial septum (IAS) were evaluated on axial and oblique sagittal CT images. Two-dimensional and Doppler TEE were performed to detect PFO. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of CT were obtained with TEE as the reference standard. A PFO was present in 26 patients at TEE. On CT images, a left-to-right contrast agent jet toward the inferior vena cava was noted in 21 patients (sensitivity, 73.1%; specificity, 98.4%; PPV, 90.5%; NPV, 94.7%). Channel-like appearance of the IAS was detected in 38 patients (sensitivity, 76.9%; specificity, 85.7%; PPV, 52.6%; NPV, 94.7%). Channel-like appearance of the IAS was noted in all patients who had a contrast agent jet. A contrast agent jet from LA to RA toward the inferior vena cava with channel-like appearance of the IAS on CT images confirms the presence of a PFO. (c) RSNA, 2008.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-08-15

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

  9. 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.

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

    International Nuclear Information System (INIS)

    Yang, Ik; Chung, Soo Young; Park, Hai Jung; Lee, Yul; Chung, Bong Wha; Shim, Jeong Won

    1997-01-01

    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

  11. Don't Rock the Boat : How Antiphase Crew Coordination Affects Rowing

    NARCIS (Netherlands)

    de Brouwer, Anouk J.; de Poel, Harjo J.; Hofmijster, Mathijs J.

    2013-01-01

    It is generally accepted that crew rowing requires perfect synchronization between the movements of the rowers. However, a long-standing and somewhat counterintuitive idea is that out-of-phase crew rowing might have benefits over in-phase (i.e., synchronous) rowing. In synchronous rowing, 5 to 6% of

  12. Contrast-enhanced ultrasound in the diagnosis of nodules in liver cirrhosis.

    Science.gov (United States)

    Kim, Tae Kyoung; Jang, Hyun-Jung

    2014-04-07

    Contrast-enhanced ultrasound (CEUS) using microbubble contrast agents are useful for the diagnosis of the nodules in liver cirrhosis. CEUS can be used as a problem-solving method for indeterminate nodules on computed tomography (CT) or magnetic resonance imaging (MRI) or as an initial diagnostic test for small newly detected liver nodules. CEUS has unique advantages over CT and MRI including no renal excretion of contrast, real-time imaging capability, and purely intravascular contrast. Hepatocellular carcinoma (HCC) is characterized by arterial-phase hypervascularity and later washout (negative enhancement). Benign nodules such as regenerative nodules or dysplastic nodules are usually isoechoic or slightly hypoechoic in the arterial phase and isoechoic in the late phase. However, there are occasional HCC lesions with atypical enhancement including hypovascular HCC and hypervascular HCC without washout. Cholangiocarcinomas are infrequently detected during HCC surveillance and mostly show rim-like or diffuse hypervascularity followed by rapid washout. Hemangiomas are often found at HCC surveillance and are easily diagnosed by CEUS. CEUS can be effectively used in the diagnostic work-up of small nodules detected at HCC surveillance. CEUS is also useful to differentiate malignant and benign venous thrombosis and to guide and monitor the local ablation therapy for HCC.

  13. Phase-enhanced defect sensitivity for EUV mask inspection

    Science.gov (United States)

    Wang, Yow-Gwo; Miyakawa, Ryan; Chao, Weilun; Goldberg, Kenneth; Neureuther, Andy; Naulleau, Patrick

    2014-10-01

    In this paper, we present a complete study on mask blank and patterned mask inspection utilizing the Zernike phase contrast method. The Zernike phase contrast method provides in-focus inspection ability to study phase defects with enhanced defect sensitivity. However, the 90 degree phase shift in the pupil will significantly reduce the amplitude defect signal at focus. In order to detect both types of defects with a single scan, an optimized phase shift instead of 90 degree on the pupil plane is proposed to achieve an acceptable trade-off on their signal strengths. We can get a 70% of its maximum signal strength at focus for both amplitude and phase defects with a 47 degree phase shift. For SNR, the tradeoff between speckle noise and signal strength has to be considered. The SNR of phase and amplitude defects at focus can both reach 11 with 13 degree phase shift and 50% apodization. Moreover, the simulation results on patterned mask inspection of partially hidden phase defects with die-to-database inspection approach on the blank inspection tool show that the improvement of the Zernike phase method is more limited. A 40% enhancement of peak signal strength can be achieved with the Zernike phase contrast method when the defect is centered in the space, while the enhancement drops to less than 10% when it is beneath the line.

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

    DEFF Research Database (Denmark)

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

    2009-01-01

    in humans. PURPOSE: To investigate the possible use of CEUS in detecting SN in patients with malignant melanomas (MM), and to improve the method by using different concentrations of contrast agent and various positions of the extremity. MATERIAL AND METHODS: Ten patients with MM on an extremity and one...... healthy volunteer were included. One milliliter of a contrast agent (Sonovue; Bracco, Milan, Italy) was injected subcutaneously on both sides of the scar from the excised tumor. Contrast-enhanced lymph channels and lymph nodes (LNs) were searched for using low-mechanical-index CEUS and by stimulated...... tissue damage, as the contrast agent was not registered for subcutaneous administration. RESULTS: In one patient, two contrast-enhanced inguinal LNs were visualized by CEUS, corresponding to two inguinal SNs found by scintigraphic imaging. No contrast-enhanced lymph channels or LNs were visualized in any...

  15. Predicting IDH mutation status of intrahepatic cholangiocarcinomas based on contrast-enhanced CT features

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Yong [Nanjing Drum Tower Hospital Clinical College of Traditional Chinese and Western Medicine, Nanjing University of Chinese Medicine, Department of Radiology, Nanjing, Jiangsu Province (China); Chen, Jun [Nanjing Drum Tower Hospital, the Affiliated Hospital of Nanjing University Medical School, Department of Pathology, Nanjing, Jiangsu Province (China); Kong, Weiwei [Nanjing Drum Tower Hospital, the Affiliated Hospital of Nanjing University Medical School, Department of Oncology, Nanjing, Jiangsu Province (China); Mao, Liang; Qiu, Yudong [Nanjing Drum Tower Hospital, the Affiliated Hospital of Nanjing University Medical School, Department of Hepatopancreatobiliary Surgery, Nanjing, Jiangsu Province (China); Kong, Wentao [Nanjing Drum Tower Hospital, the Affiliated Hospital of Nanjing University Medical School, Department of Ultrasonography, Nanjing, Jiangsu Province (China); Zhou, Qun [Nanjing Drum Tower Hospital Clinical College of Nanjing Medical University, Department of Radiology, Nanjing, Jiangsu Province (China); Zhou, Zhengyang; Zhu, Bin; He, Jian [Nanjing Drum Tower Hospital, the Affiliated Hospital of Nanjing University Medical School, Department of Radiology, Nanjing, Jiangsu Province (China); Wang, Zhongqiu [Jiangsu Province Hospital of Traditional Chinese Medicine, the Affiliated Hospital of Nanjing University of Chinese Medicine, Department of Radiology, Nanjing, Jiangsu Province (China)

    2018-01-15

    To explore the difference in contrast-enhanced computed tomography (CT) features of intrahepatic cholangiocarcinomas (ICCs) with different isocitrate dehydrogenase (IDH) mutation status. Clinicopathological and contrast-enhanced CT features of 78 patients with 78 ICCs were retrospectively analysed and compared based on IDH mutation status. There were 11 ICCs with IDH mutation (11/78, 14.1%) and 67 ICCs without IDH mutation (67/78, 85.9%). IDH-mutated ICCs showed intratumoral artery more often than IDH-wild ICCs (p = 0.023). Most ICCs with IDH mutation showed rim and internal enhancement (10/11, 90.9%), while ICCs without IDH mutation often appeared diffuse (26/67, 38.8%) or with no enhancement (4/67, 6.0%) in the arterial phase (p = 0.009). IDH-mutated ICCs showed significantly higher CT values, enhancement degrees and enhancement ratios in arterial and portal venous phases than IDH-wild ICCs (all p < 0.05). The CT value of tumours in the portal venous phase performed best in distinguishing ICCs with and without IDH mutation, with an area under the curve of 0.798 (p = 0.002). ICCs with and without IDH mutation differed significantly in arterial enhancement mode, and the tumour enhancement degree on multiphase contrast-enhanced CT was helpful in predicting IDH mutation status. (orig.)

  16. Unusual presentation of a pancreatic insulinoma in helical CT and dynamic contrast-enhanced MR imaging: case report

    Energy Technology Data Exchange (ETDEWEB)

    Iglesias, A.; Arias, M.; Brasa, J. [Unidad de Resonancia Magnetica (Medtec), Hospital Xeral-Cies, Vigo (Spain); Casal, M. [Unidad de Radiologia Intervencionista, Hospital Xeral-Cies, Vigo (Spain); Paramo, C. [Servicio de Endocrinologia, Hospital Xeral-Cies, Vigo (Spain); Fiano, C. [Servicio de Anatomia Patologica, Hospital Xeral-Cies, Vigo (Spain)

    2001-06-01

    Insulinomas are pancreatic neoplasms that can be radiologically characterized typically because of their tendency to present intense and early contrast enhancement with a wash-out phenomenon. In this sense, we report an unusual case of a hypovascular solid pancreatic insulinoma confirmed with surgery and pathologic analysis, in a patient with normal serum insulin levels. In the two-phase helical CT, the mass behaved as a hypodense lesion with respect to the surrounding pancreatic parenchyma during the arterial phase and as a hypointense lesion during the dynamic contrast-enhanced MR imaging. Pathologic examination demonstrated a hypercellular tumor with poor vascularization of intervening stroma which showed prominent amyloid deposits. (orig.)

  17. Unusual presentation of a pancreatic insulinoma in helical CT and dynamic contrast-enhanced MR imaging: case report

    International Nuclear Information System (INIS)

    Iglesias, A.; Arias, M.; Brasa, J.; Casal, M.; Paramo, C.; Fiano, C.

    2001-01-01

    Insulinomas are pancreatic neoplasms that can be radiologically characterized typically because of their tendency to present intense and early contrast enhancement with a wash-out phenomenon. In this sense, we report an unusual case of a hypovascular solid pancreatic insulinoma confirmed with surgery and pathologic analysis, in a patient with normal serum insulin levels. In the two-phase helical CT, the mass behaved as a hypodense lesion with respect to the surrounding pancreatic parenchyma during the arterial phase and as a hypointense lesion during the dynamic contrast-enhanced MR imaging. Pathologic examination demonstrated a hypercellular tumor with poor vascularization of intervening stroma which showed prominent amyloid deposits. (orig.)

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2005-12-15

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

  19. Contrast-enhanced turbo spin-echo(TSE) T1-weighted imaging: improved contrast of enhancing lesions

    International Nuclear Information System (INIS)

    Choi, Sung Wook; Lee, Ghi Jai; Shim, Jae Chan; Lee, Young Ju; Jeong, Se Hyung; Kim, Ho kyun

    1997-01-01

    The purpose of this study was to evaluate the effect of contrast improvement of enhancing brain lesions by inherent magnetization transfer effect in turbo spin-echo(TSE)T1-weighted MR imaging. Twenty-six enhancing lesions of 19 patients were included in this study. Using a 1.0T superconductive MR unit, contrast-enhanced SE T1-weighted images(TR=3D600 msec, TE=3D12 msec, NEX=3D2, acquistition time=3D4min 27sec) and contrast-enhanced TSE T1-weighted images(TR=3D600 msec, TE=3D12, acquistition time=3D1min 44sec) were obtained. Signal intensities at enhancing lesions and adjacent white matter were measured in the same regions of both images. Signal-to-noise ratio(SNR) of enhancing lesions and adjacent white matter, and con-trast-to-noise ratio(CNR) and lesion-to-background contrast (LBC) of enhancing lesions were calculated and statistically analysed using the paired t-test. On contrast-enhanced TSE T1-weighted images, SNR of enhancing lesions and adjacent white matter decreased by 18%(p<0.01) and 32%(p<0.01), respectively, compared to contrast-enhanced SE T1-weighted images. CNR and LBC of enhancing lesions increased by 16%(p<0.05) and 66%(p<0.01), respectively. Due to the proposed inherent magnetization transfer effects in TSE imaging, con-trast-enhanced T1-weighted TSE images demonstrated a statistically significant improvement in CNR and LBC, compared to conventional contrast-enhanced T1-weighted SE images, and scan time was much shorter

  20. Accurate estimation of global and regional cardiac function by retrospectively gated multidetector row computed tomography. Comparison with cine magnetic resonance imaging

    International Nuclear Information System (INIS)

    Belge, Benedicte; Pasquet, Agnes; Vanoverschelde, Jean-Louis J.; Coche, Emmanuel; Gerber, Bernhard L.

    2006-01-01

    Retrospective reconstruction of ECG-gated images at different parts of the cardiac cycle allows the assessment of cardiac function by multi-detector row CT (MDCT) at the time of non-invasive coronary imaging. We compared the accuracy of such measurements by MDCT to cine magnetic resonance (MR). Forty patients underwent the assessment of global and regional cardiac function by 16-slice MDCT and cine MR. Left ventricular (LV) end-diastolic and end-systolic volumes estimated by MDCT (134±51 and 67±56 ml) were similar to those by MR (137±57 and 70±60 ml, respectively; both P=NS) and strongly correlated (r=0.92 and r=0.95, respectively; both P<0.001). Consequently, LV ejection fractions by MDCT and MR were also similar (55±21 vs. 56±21%; P=NS) and highly correlated (r=0.95; P<0.001). Regional end-diastolic and end-systolic wall thicknesses by MDCT were highly correlated (r=0.84 and r=0.92, respectively; both P<0.001), but significantly lower than by MR (8.3±1.8 vs. 8.8±1.9 mm and 12.7±3.4 vs. 13.3±3.5 mm, respectively; both P<0.001). Values of regional wall thickening by MDCT and MR were similar (54±30 vs. 51±31%; P=NS) and also correlated well (r=0.91; P<0.001). Retrospectively gated MDCT can accurately estimate LV volumes, EF and regional LV wall thickening compared to cine MR. (orig.)

  1. Independent component analysis of dynamic contrast-enhanced computed tomography images

    Energy Technology Data Exchange (ETDEWEB)

    Koh, T S [School of Electrical and Electronic Engineering, Nanyang Technological University, 50 Nanyang Ave, Singapore 639798 (Singapore); Yang, X [School of Electrical and Electronic Engineering, Nanyang Technological University, 50 Nanyang Ave, Singapore 639798 (Singapore); Bisdas, S [Department of Diagnostic and Interventional Radiology, Johann Wolfgang Goethe University Hospital, Theodor-Stern-Kai 7, D-60590 Frankfurt (Germany); Lim, C C T [Department of Neuroradiology, National Neuroscience Institute, 11 Jalan Tan Tock Seng, Singapore 308433 (Singapore)

    2006-10-07

    Independent component analysis (ICA) was applied on dynamic contrast-enhanced computed tomography images of cerebral tumours to extract spatial component maps of the underlying vascular structures, which correspond to different haemodynamic phases as depicted by the passage of the contrast medium. The locations of arteries, veins and tumours can be separately identified on these spatial component maps. As the contrast enhancement behaviour of the cerebral tumour differs from the normal tissues, ICA yields a tumour component map that reveals the location and extent of the tumour. Tumour outlines can be generated using the tumour component maps, with relatively simple segmentation methods. (note)

  2. Four-channel multidetector-row computed tomography in the evaluation of facial fractures - optimized parameters for acquisition and multiplanar reformation

    International Nuclear Information System (INIS)

    Omid, P. M.

    2002-08-01

    The first part of this thesis is designed to give the reader a comprehensive survey on the complex basic principles of computed tomography (CT), from the early beginning to the recent development of multidetector-row CT (MD-CT). Attention is focused on imaging of trauma in general and on imaging of facial fractures in particular. The second part of this thesis describes a clinical study performed to optimize acquisition protocols and multiplanar reformation (MPR) algorithms for the evaluation of facial fractures using MD-CT, which has not been yet described in literature. For this study, a cadaver head with artificial blunt facial trauma was examined using a 4-channel MD-CT scanner. The influence of acquisition parameters (collimation: 2x0.5 mm/4x1 mm/4x2.5 mm; tube current: 120 mAs/90 mAs/60 mAs), image reconstruction algorithms (standard vs. ultra-high resolution (UHR) modes; reconstructed slice thicknesses: 0.5 mm/1 mm/3 mm; increment: 0.3 mm/0.6 mm/1.5 mm), and reformation algorithms (slice thicknesses: 0.5 mm/1 mm/3 mm; overlap: 0.5 mm/1 mm/3 mm) on detectability of facial fractures in MPRs with MD-CT was analyzed. Effects of algorithms and parameters on image noise, artifacts and delineation of soft tissues were evaluated. The results of this study reliably demonstrate that fracture detection was significantly higher with thin MPRs (0.5/0.5 mm, 1/0.5 mm, 1/1 mm) (p = 0 .014) acquired with 2x0.5 mm collimation (p = 0 .046), in UHR mode (p .0005) with 120 mAs (p = 0 .025). Inter-observer variability showed very good agreement (κ > = 0 .942). Non-UHR mode, lower mAs and thick MPRs (3/0.5 mm, 3/1 mm, 3/0.5 mm) showed significantly decreased detectability. (author)

  3. Phase contrast imaging with coherent high energy X-rays

    Energy Technology Data Exchange (ETDEWEB)

    Snigireva, I. [ESRF, Grenoble (France)

    1997-02-01

    X-ray imaging concern high energy domain (>6 keV) like a contact radiography, projection microscopy and tomography is used for many years to discern the features of the internal structure non destructively in material science, medicine and biology. In so doing the main contrast formation is absorption that makes some limitations for imaging of the light density materials and what is more the resolution of these techniques is not better than 10-100 {mu}m. It was turned out that there is now way in which to overcome 1{mu}m or even sub-{mu}m resolution limit except phase contrast imaging. It is well known in optics that the phase contrast is realised when interference between reference wave front and transmitted through the sample take place. Examples of this imaging are: phase contrast microscopy suggested by Zernike and Gabor (in-line) holography. Both of this techniques: phase contrast x-ray microscopy and holography are successfully progressing now in soft x-ray region. For imaging in the hard X-rays to enhance the contrast and to be able to resolve phase variations across the beam the high degree of the time and more importantly spatial coherence is needed. Because of this it was reasonable that the perfect crystal optics was involved like Bonse-Hart interferometry, double-crystal and even triple-crystal set-up using Laue and Bragg geometry with asymmetrically cut crystals.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2009-02-15

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

  5. Algorithms for contrast enhancement of electronic portal images

    International Nuclear Information System (INIS)

    Díez, S.; Sánchez, S.

    2015-01-01

    An implementation of two new automatized image processing algorithms for contrast enhancement of portal images is presented as suitable tools which facilitate the setup verification and visualization of patients during radiotherapy treatments. In the first algorithm, called Automatic Segmentation and Histogram Stretching (ASHS), the portal image is automatically segmented in two sub-images delimited by the conformed treatment beam: one image consisting of the imaged patient obtained directly from the radiation treatment field, and the second one is composed of the imaged patient outside it. By segmenting the original image, a histogram stretching can be independently performed and improved in both regions. The second algorithm involves a two-step process. In the first step, a Normalization to Local Mean (NLM), an inverse restoration filter is applied by dividing pixel by pixel a portal image by its blurred version. In the second step, named Lineally Combined Local Histogram Equalization (LCLHE), the contrast of the original image is strongly improved by a Local Contrast Enhancement (LCE) algorithm, revealing the anatomical structures of patients. The output image is lineally combined with a portal image of the patient. Finally the output images of the previous algorithms (NLM and LCLHE) are lineally combined, once again, in order to obtain a contrast enhanced image. These two algorithms have been tested on several portal images with great results. - Highlights: • Two Algorithms are implemented to improve the contrast of Electronic Portal Images. • The multi-leaf and conformed beam are automatically segmented into Portal Images. • Hidden anatomical and bony structures in portal images are revealed. • The task related to the patient setup verification is facilitated by the contrast enhancement then achieved.

  6. Boundary-enhancement in propagation-based x-ray phase-contrast tomosynthesis improves depth position characterization.

    Science.gov (United States)

    Guan, Huifeng; Xu, Qiaofeng; Garson, Alfred B; Anastasio, Mark A

    2015-04-21

    Propagation-based x-ray phase-contrast (PB XPC) tomosynthesis combines the concepts of tomosynthesis and XPC imaging to realize the advantages of both for biological imaging applications. Tomosynthesis permits reductions in acquisition times compared with full-view tomography, while XPC imaging provides the opportunity to resolve weakly absorbing structures. In this note, an investigation of the depth resolving properties of PB XPC tomosynthesis is conducted. The results demonstrate that in-plane structures display strong boundary-enhancement while out-of-plane structures do not. This effect can facilitate the identification of in-plane structures in PB XPC tomosynthesis that could normally not be distinguished from out-of-plane structures in absorption-based tomosynthesis.

  7. Boundary-enhancement in propagation-based x-ray phase-contrast tomosynthesis improves depth position characterization

    International Nuclear Information System (INIS)

    Guan, Huifeng; Xu, Qiaofeng; Garson, Alfred B III; Anastasio, Mark A

    2015-01-01

    Propagation-based x-ray phase-contrast (PB XPC) tomosynthesis combines the concepts of tomosynthesis and XPC imaging to realize the advantages of both for biological imaging applications. Tomosynthesis permits reductions in acquisition times compared with full-view tomography, while XPC imaging provides the opportunity to resolve weakly absorbing structures. In this note, an investigation of the depth resolving properties of PB XPC tomosynthesis is conducted. The results demonstrate that in-plane structures display strong boundary-enhancement while out-of-plane structures do not. This effect can facilitate the identification of in-plane structures in PB XPC tomosynthesis that could normally not be distinguished from out-of-plane structures in absorption-based tomosynthesis. (note)

  8. Contrast enhancement by lipid-based MRI contrast agents in mouse atherosclerotic plaques; a longitudinal study

    NARCIS (Netherlands)

    den Adel, Brigit; van der Graaf, Linda M.; Que, Ivo; Strijkers, Gustav J.; Löwik, Clemens W.; Poelmann, Robert E.; van der Weerd, Louise

    2013-01-01

    The use of contrast-enhanced MRI to enable in vivo specific characterization of atherosclerotic plaques is increasing. In this study the intrinsic ability of two differently sized gadolinium-based contrast agents to enhance atherosclerotic plaques in ApoE(-/-) mice was evaluated with MRI. We

  9. Contrast-enhanced ultrasound study of primary hepatic angiosarcoma: A pitfall of non-enhancement

    International Nuclear Information System (INIS)

    Wang, Liang; Lv, Ke; Chang, Xiao-Yan; Xia, Yu; Yang, Zhi-Ying; Jiang, Yu-Xin; Dai, Qing; Tan, Li; Li, Jian-Chu

    2012-01-01

    Highlights: ► The contrast-enhanced ultrasound (CEUS) characteristics of primary hepatic angiosarcoma (PHA) in three patients were retrospectively analyzed. ► PHA appeared similar peripheral enhancement pattern in our series. ► Non-necrotic tumor tissue of PHA unexpectedly demonstrated non-enhancement on CEUS. ► It may be associated with the very low velocity of blood flow in the central region of tumors. ► This interesting finding warrants further investigations, particularly on intratumoral hemodynamics. -- Abstract: Objective: To investigate the contrast-enhanced ultrasound (CEUS) characteristics of primary hepatic angiosarcoma (PHA). Methods: The sonographic findings and CEUS images of PHA in three patients were retrospectively analyzed. Results: In our study, 3 cases of PHA (2 multiple nodules and 1 solitary mass) showed similar enhancement pattern on CEUS, characterized by remarkable central non-enhancement and peripheral irregular enhancement in the arterial and portal phase, and complete wash-out in the late phase. Furthermore, we unexpectedly found that abundant neoplastic tissues were present in the central area of non-enhancement on pathological evaluation. Based on literature review, we supposed that the unusual finding may be associated with the very low velocity of blood flow in the central region of tumors. Conclusion: CEUS could well depict PHA with some common features, which may provide valuable clues in diagnosis of this rare disease. And non-necrotic tumor tissue of PHA could also demonstrate non-enhancement on CEUS, which warrant further investigations

  10. Investigation of physical image characteristics and phenomenon of edge enhancement by phase contrast using equipment typical for mammography

    International Nuclear Information System (INIS)

    Yamazaki, Asumi; Ichikawa, Katsuhiro; Kodera, Yoshie

    2008-01-01

    A technique called phase contrast mammography (PCM) has only recently been applied in clinical examination. In this application, PCM images are acquired at a 1.75x magnification using an x-ray tube for clinical use, and then reduced to the real size of the object by image processing. The images showed enhanced object edges; reportedly, this enhancement occurred because of the refraction of x rays through a cylindrical object. The authors measured the physical image characteristics of PCM to compare the image characteristics of PCM with those of conventional mammography. More specifically, they measured the object-edge-response characteristics and the noise characteristics in the spatial frequency domain. The results revealed that the edge-response characteristics of PCM outperformed those of conventional mammography. In addition, the characteristics changed with the object-placement conditions and the object shapes. The noise characteristics of PCM were better than those of conventional mammography. Subsequently, to verify why object edges were enhanced in PCM images, the authors simulated image profiles that would be obtained if the x rays were refracted and totally reflected by using not only a cylindrical substance but also a planar substance as the object. So, they confirmed that the object edges in PCM images were enhanced because x rays were refracted irrespective of the object shapes. Further, they found that the edge enhancements depended on the object shapes and positions. It was also proposed that the larger magnification than 1.75 in the commercialized system might be more suitable for PCM. Finally, the authors investigated phase-contrast effects to breast tissues by the simulation and demonstrated that PCM would be helpful in the diagnoses of mammography.

  11. Dual-energy CT for detection of contrast enhancement or leakage within high-density haematomas in patients with intracranial haemorrhage

    Energy Technology Data Exchange (ETDEWEB)

    Watanabe, Yoshiyuki; Tsukabe, Akio; Kunitomi, Yuki; Nishizawa, Mitsuo; Arisawa, Atsuko; Tanaka, Hisashi; Tomiyama, Noriyuki [Osaka University Graduate School of Medicine, Department of Diagnostic and Interventional Radiology, Suita, Osaka (Japan); Yoshiya, Kazuhisa; Shimazu, Takeshi [Osaka University Graduate School of Medicine, Department of Traumatology and Acute Critical Medicine, Osaka (Japan)

    2014-04-15

    Our study aimed to elucidate the diagnostic performance of dual-energy CT (DECT) in the detection of contrast enhancement in intracranial haematomas (ICrH) with early phase dual-energy computed tomography angiography (CTA) and compare the results with those obtained by delayed CT enhancement. Thirty-six patients with ICrH were retrospectively included in this study. All patients had undergone single-energy non-contrast CT and contrast-enhanced dual-source DECT. DECT images were post-processed with commercial software, followed by obtaining iodine images and virtual non-contrast images and generating combined images that created the impression of 120-kVp images. Two neuroradiologists, blinded to the patients' data, reviewed two reading sessions: session A (non-contrast CT and combined CT) and session B (non-contrast CT, combined CT, and iodine images) for detection of contrast enhancement in the haematomas. Contrast leakage or enhancement was detected in 23 (57.5 %) out of 40 haemorrhagic lesions in 36 patients on delayed CT. Three enhanced lesions were depicted only in the DECT iodine images. The sensitivity, specificity, positive predictive value, and negative predictive value of session A were 82.6, 94.1, 95.0, and 80.0 %, respectively, and those of session B were 95.7, 94.1, 95.7, and 94.1 %, respectively. DECT emphasised the iodine enhancement and facilitated the detection of contrast enhancement or leakage. (orig.)

  12. Dual-energy CT for detection of contrast enhancement or leakage within high-density haematomas in patients with intracranial haemorrhage.

    Science.gov (United States)

    Watanabe, Yoshiyuki; Tsukabe, Akio; Kunitomi, Yuki; Nishizawa, Mitsuo; Arisawa, Atsuko; Tanaka, Hisashi; Yoshiya, Kazuhisa; Shimazu, Takeshi; Tomiyama, Noriyuki

    2014-04-01

    Our study aimed to elucidate the diagnostic performance of dual-energy CT (DECT) in the detection of contrast enhancement in intracranial haematomas (ICrH) with early phase dual-energy computed tomography angiography (CTA) and compare the results with those obtained by delayed CT enhancement. Thirty-six patients with ICrH were retrospectively included in this study. All patients had undergone single-energy non-contrast CT and contrast-enhanced dual-source DECT. DECT images were post-processed with commercial software, followed by obtaining iodine images and virtual non-contrast images and generating combined images that created the impression of 120-kVp images. Two neuroradiologists, blinded to the patients' data, reviewed two reading sessions: session A (non-contrast CT and combined CT) and session B (non-contrast CT, combined CT, and iodine images) for detection of contrast enhancement in the haematomas. Contrast leakage or enhancement was detected in 23 (57.5 %) out of 40 haemorrhagic lesions in 36 patients on delayed CT. Three enhanced lesions were depicted only in the DECT iodine images. The sensitivity, specificity, positive predictive value, and negative predictive value of session A were 82.6, 94.1, 95.0, and 80.0 %, respectively, and those of session B were 95.7, 94.1, 95.7, and 94.1 %, respectively. DECT emphasised the iodine enhancement and facilitated the detection of contrast enhancement or leakage.

  13. Dual-energy CT for detection of contrast enhancement or leakage within high-density haematomas in patients with intracranial haemorrhage

    International Nuclear Information System (INIS)

    Watanabe, Yoshiyuki; Tsukabe, Akio; Kunitomi, Yuki; Nishizawa, Mitsuo; Arisawa, Atsuko; Tanaka, Hisashi; Tomiyama, Noriyuki; Yoshiya, Kazuhisa; Shimazu, Takeshi

    2014-01-01

    Our study aimed to elucidate the diagnostic performance of dual-energy CT (DECT) in the detection of contrast enhancement in intracranial haematomas (ICrH) with early phase dual-energy computed tomography angiography (CTA) and compare the results with those obtained by delayed CT enhancement. Thirty-six patients with ICrH were retrospectively included in this study. All patients had undergone single-energy non-contrast CT and contrast-enhanced dual-source DECT. DECT images were post-processed with commercial software, followed by obtaining iodine images and virtual non-contrast images and generating combined images that created the impression of 120-kVp images. Two neuroradiologists, blinded to the patients' data, reviewed two reading sessions: session A (non-contrast CT and combined CT) and session B (non-contrast CT, combined CT, and iodine images) for detection of contrast enhancement in the haematomas. Contrast leakage or enhancement was detected in 23 (57.5 %) out of 40 haemorrhagic lesions in 36 patients on delayed CT. Three enhanced lesions were depicted only in the DECT iodine images. The sensitivity, specificity, positive predictive value, and negative predictive value of session A were 82.6, 94.1, 95.0, and 80.0 %, respectively, and those of session B were 95.7, 94.1, 95.7, and 94.1 %, respectively. DECT emphasised the iodine enhancement and facilitated the detection of contrast enhancement or leakage. (orig.)

  14. Angiogenesis and dynamic contrast enhanced MRI of benign and malignant breast lesions: preliminary results

    International Nuclear Information System (INIS)

    Liu Peifang; Bao Runxian; Niu Yun; Yu Yong

    2002-01-01

    Objective: To determine whether dynamic contrast enhanced MRI features of 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: Thirty-eight patients with histopathologically verified breast lesions underwent dynamic contrast enhanced MRI. SI changes during dynamic scanning were assessed quantitatively. Early-phase enhancement rate and enhancement amplitude were calculated. Time-SI 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 7.5 min), 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 immuno-histochemical staining method in all the histologic specimens by pathologists without the knowledge of the results of the MR examination. 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 21 malignant lesions were statistically higher than the mean MVD and VEGF expression for 17 benign lesions. High VEGF expression of benign and malignant breast lesions showed an association with increased MVD. Among all 38 lesions, greater (> 60%) MR early-phase enhancement rate and time-SI curve type II and III showed an association with increased MVD and higher VEGF expression level. All the differences mentioned above showed statistical significance except that the difference between VEGF expression and the distribution of curve types had no statistical significance. No significant relationships were observed between the mean of enhancement

  15. Zernike phase contrast cryo-electron tomography of whole bacterial cells.

    Science.gov (United States)

    Guerrero-Ferreira, Ricardo C; Wright, Elizabeth R

    2014-01-01

    Cryo-electron tomography (cryo-ET) provides three-dimensional (3D) structural information of bacteria preserved in a native, frozen-hydrated state. The typical low contrast of tilt-series images, a result of both the need for a low electron dose and the use of conventional defocus phase-contrast imaging, is a challenge for high-quality tomograms. We show that Zernike phase-contrast imaging allows the electron dose to be reduced. This limits movement of gold fiducials during the tilt series, which leads to better alignment and a higher-resolution reconstruction. Contrast is also enhanced, improving visibility of weak features. The reduced electron dose also means that more images at more tilt angles could be recorded, further increasing resolution. Copyright © 2013 Elsevier Inc. All rights reserved.

  16. Multidetector computer tomography in the pancreatic adenocarcinoma assessment: an update

    Directory of Open Access Journals (Sweden)

    Vincenza Granata

    2016-11-01

    Full Text Available Abstract Ductal adenocarcinoma of the pancreas is one of the most aggressive forms of cancer, with only a minority of cases being resectable at the moment of their diagnosis. The accurate detection and characterization of pancreatic carcinoma is very important for patient management. Multidetector-row computed tomography (MDCT has become the cross-sectional modality of choice in the diagnosis, staging, treatment planning, and follow-up of patients with pancreatic tumors. However, approximately 11% of ductal adenocarcinomas still remain undetected at MDCT because of the lack of attenuation gradient between the lesion and the adjacent pancreatic parenchyma. In this systematic literature review we investigate the current evolution of the CT technique, limitations, and perspectives in the evaluation of pancreatic carcinoma.

  17. Visual Contrast Enhancement Algorithm Based on Histogram Equalization

    Science.gov (United States)

    Ting, Chih-Chung; Wu, Bing-Fei; Chung, Meng-Liang; Chiu, Chung-Cheng; Wu, Ya-Ching

    2015-01-01

    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. PMID:26184219

  18. 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.

  19. Robustness of phase retrieval methods in x-ray phase contrast imaging: A comparison

    International Nuclear Information System (INIS)

    Yan, Aimin; Wu, Xizeng; Liu, Hong

    2011-01-01

    Purpose: The robustness of the phase retrieval methods is of critical importance for limiting and reducing radiation doses involved in x-ray phase contrast imaging. This work is to compare the robustness of two phase retrieval methods by analyzing the phase maps retrieved from the experimental images of a phantom. Methods: Two phase retrieval methods were compared. One method is based on the transport of intensity equation (TIE) for phase contrast projections, and the TIE-based method is the most commonly used method for phase retrieval in the literature. The other is the recently developed attenuation-partition based (AP-based) phase retrieval method. The authors applied these two methods to experimental projection images of an air-bubble wrap phantom for retrieving the phase map of the bubble wrap. The retrieved phase maps obtained by using the two methods are compared. Results: In the wrap's phase map retrieved by using the TIE-based method, no bubble is recognizable, hence, this method failed completely for phase retrieval from these bubble wrap images. Even with the help of the Tikhonov regularization, the bubbles are still hardly visible and buried in the cluttered background in the retrieved phase map. The retrieved phase values with this method are grossly erroneous. In contrast, in the wrap's phase map retrieved by using the AP-based method, the bubbles are clearly recovered. The retrieved phase values with the AP-based method are reasonably close to the estimate based on the thickness-based measurement. The authors traced these stark performance differences of the two methods to their different techniques employed to deal with the singularity problem involved in the phase retrievals. Conclusions: This comparison shows that the conventional TIE-based phase retrieval method, regardless if Tikhonov regularization is used or not, is unstable against the noise in the wrap's projection images, while the AP-based phase retrieval method is shown in these

  20. 64-Row multidetector CT virtual hysterosalpingography. Findings in 2500 patients

    International Nuclear Information System (INIS)

    Carrascosa, Patricia; Capunay, Carlos; Baronio, Mariano; Vallejos, Javier; Papier, Sergio; Carrascosa, Jorge

    2011-01-01

    Objective. To depict typical features of virtual hysterosalpingography (VHSG) in infertile patients. Material and methods: 2500 VHSG performed using a 64-row MOCT were evaluated. Results: Cervical abnormalities visualized corresponded to parietal irregularities (21%); thickened folds (9%); polyps (11%); diverticula (5%); cervical strictures (8%), and synechiae (1.5%). At the level of uterine cavity, polyps (44%); submucous myomas (8%); intramural and subserosal fibroids (11%); synechiae (10%); malformations (10%); adenomyosis (4%), and cesarean section scar (3%). Unilateral hydrosalpinx (7%) and bilateral hydrosalpinx (2%). Tubal obstruction was reported in 6% of cases. The average radiation dose was 0.94 mSv. Eighty-four percent of the patients reported mild pain or no postoperative discomfort. Conclusions: The virtual hysterosalpingography allowed a proper assessment of the internal genital organs, providing useful diagnostic information on infertility and other gynecological disorders. It constitutes a virtually painless, low-dose radiation technique, besides being well tolerated by patients

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

    International Nuclear Information System (INIS)

    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 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

  2. Contrast-enhanced CT and diffusion-weighted MR imaging: Performance as a prognostic factor in patients with pancreatic ductal adenocarcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Fukukura, Yoshihiko, E-mail: fukukura@m.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); Takumi, Koji [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); Shinchi, Hiroyuki [Department of Surgical Oncology and Digestive Surgery, Kagoshima University Graduate School of Medical and Dental Sciences, 8-35-1 Sakuragaoka, Kagoshima City 890-8544 (Japan); Kamimura, Kiyohisa; Yoneyama, Tomohide; Tateyama, Akihiro [Department of Radiology, Kagoshima University Graduate School of Medical and Dental Sciences, 8-35-1 Sakuragaoka, Kagoshima City 890-8544 (Japan)

    2014-04-15

    Objective: To determine whether contrast enhancement of CT and apparent diffusion coefficient on diffusion-weighted MR imaging are important parameters that can predict outcomes for patients with pancreatic ductal adenocarcinoma. Materials and methods: Ninety-two patients with histologically confirmed pancreatic ductal adenocarcinoma who underwent quadriphasic CT (including unenhanced, pancreatic parenchymal, portal venous and delayed phases) and fat-suppressed single-shot echo-planar diffusion-weighted MR imaging at 3.0 T were retrospectively analyzed to investigate prognostic factors. Overall survival curves were drawn using the Kaplan–Meier method. Effects on survival of variables including age, sex, tumor location, tumor size, TNM stage, carbohydrate antigen 19-9, carcinoembryonic antigen, treatment, tumor contrast enhancement and apparent diffusion coefficient values were analyzed in univariate analysis using the log-rank test. Variables were analyzed in multivariate analyses using the Cox proportional hazards regression model. Results: Median survival for the entire patient population was 18.2 months. Higher contrast enhancement during all phases was associated with significantly longer overall survival (P < 0.001 for all phases). The difference in overall survival between groups divided by median apparent diffusion coefficient value was not significant (P = 0.672). TNM stage (P = 0.026) and tumor contrast enhancement on CT (P = 0.027) were significantly related to survival in multivariate analysis. Conclusions: Poor enhancement of pancreatic adenocarcinomas on enhanced CT is associated with reduced patient survival.

  3. Contrast-enhanced CT and diffusion-weighted MR imaging: Performance as a prognostic factor in patients with pancreatic ductal adenocarcinoma

    International Nuclear Information System (INIS)

    Fukukura, Yoshihiko; Takumi, Koji; Higashi, Michiyo; Shinchi, Hiroyuki; Kamimura, Kiyohisa; Yoneyama, Tomohide; Tateyama, Akihiro

    2014-01-01

    Objective: To determine whether contrast enhancement of CT and apparent diffusion coefficient on diffusion-weighted MR imaging are important parameters that can predict outcomes for patients with pancreatic ductal adenocarcinoma. Materials and methods: Ninety-two patients with histologically confirmed pancreatic ductal adenocarcinoma who underwent quadriphasic CT (including unenhanced, pancreatic parenchymal, portal venous and delayed phases) and fat-suppressed single-shot echo-planar diffusion-weighted MR imaging at 3.0 T were retrospectively analyzed to investigate prognostic factors. Overall survival curves were drawn using the Kaplan–Meier method. Effects on survival of variables including age, sex, tumor location, tumor size, TNM stage, carbohydrate antigen 19-9, carcinoembryonic antigen, treatment, tumor contrast enhancement and apparent diffusion coefficient values were analyzed in univariate analysis using the log-rank test. Variables were analyzed in multivariate analyses using the Cox proportional hazards regression model. Results: Median survival for the entire patient population was 18.2 months. Higher contrast enhancement during all phases was associated with significantly longer overall survival (P < 0.001 for all phases). The difference in overall survival between groups divided by median apparent diffusion coefficient value was not significant (P = 0.672). TNM stage (P = 0.026) and tumor contrast enhancement on CT (P = 0.027) were significantly related to survival in multivariate analysis. Conclusions: Poor enhancement of pancreatic adenocarcinomas on enhanced CT is associated with reduced patient survival

  4. In silico optimization of phase-change materials for digital memories: a survey of first-row transition-metal dopants for Ge2Sb2Te5

    International Nuclear Information System (INIS)

    Skelton, J M; Elliott, S R

    2013-01-01

    Phase-change materials are the alloys at the heart of an emerging class of next-generation, non-volatile digital memory technologies. However, the widely studied Ge–Sb–Te system possesses several undesirable properties, and enhancing its properties, e.g. by doping, is an area of active research. Various first-row transition-metal dopants have been shown to impart useful property enhancements, but a systematic study of the entire period has yet to be undertaken, and little has been done to investigate their interaction with the host material at the atomic level. We have carried out first-principles computer simulations of the complete phase-change cycle in Ge 2 Sb 2 Te 5 doped with each of the ten first-row transition metals. In this article, we present a comprehensive survey of the electronic, magnetic and optical properties of these doped materials. We discuss in detail their atomic-level structure, and relate the microscopic behaviours of the dopant atoms to their influence on the Ge 2 Sb 2 Te 5 host. By considering an entire family of similar materials, we identify trends and patterns which might be used to predict suitable dopants for optimizing materials for specific phase-change applications. The computational method employed here is general, and this materials-discovery approach could be applied in the future to study other families of potential dopants for such materials. (paper)

  5. Value of fat suppression and dynamic contrast-enhanced MRI in the diagnosis of insulinoma

    International Nuclear Information System (INIS)

    Xu Zengbin; Ruan Lingxiang; Peng Zhiyi; Zhang Minming; Xu Shunliang; Zhang Xidao

    2003-01-01

    Objective: To evaluate the value of fat suppression and dynamic contrast-enhanced MRI in the preoperative localization of insulinoma. Methods: Twelve cases with pathologically proven insulinoma were evaluated with MRI. SE T 1 WI, FSE T 2 WI, T 1 WI and T 2 WI with fat suppression, dynamic contrast-enhanced FMPSPGR sequences were used in MR scanning. Results: On SE T 1 WI, the lesions displayed hypointense in 4, isointense in 8 cases. Lesions showed hyperintense in 4, isointense in 8 cases on FSE T 2 WI. In contrast, 7 cases appeared as hypointense on T 1 WI with fat suppression and 6 cases appeared as hyperintense on T 2 WI with fat suppression. With dynamic contrast-enhanced FMPSPGR sequence 11 of 12 insulinomas were detected. In the arterial phase, the lesions presented as hyperintense with different degrees in 11 cases and isointense in 1 case. 6 cases remained hyperintense and 6 cases were isointense in pancreatic parenchymal and portal phase. 4 lesions were identified only in dynamic enhancement images. The diagnostic accuracy of insulinoma by dynamic contrast-enhanced MRI was 91.7% (11/12) as compared with histological study. Conclusion: The results indicate that dynamic contrast-enhanced MRI is an sensitive and accurate method for the preoperative localization of insulinoma

  6. Evaluation of 16 detector row spiral CT in diagnosing pulmonary embolism

    International Nuclear Information System (INIS)

    Yu Xiaokun; Li Lei

    2008-01-01

    Objective: To investigate the value of 16 detector row spiral CT in the diagnosis of pulmonary embolism(PE). Methods: Imaging data of 20 patients (plain 16 detector row spiral CT scanning plus enhanced scanning imaging) highly suspected of PE was retrospectively analyzed. Results: Among the 20 cases, embolism was showed in 13 patients on 16 detector row spiral CT pulmonary angiography (MSCTPA). 6 cases of the 13 PE's patients have masculine findings on plain MSCT scanning images. Localized tenuous lung markings, dilated pulmonary artery, 'mosaic' sign, pleural or pericardial effusion, local high attenuation centrally in the pulmonary arteries and lung infarction occurred respectively. Conclusion: MSCTPA may be an effective, simple and safe technique for the diagnosis of PE. It was a reliable means in defecting PE However, for the cases unfit for contrast media and cases only suitable for unenhanced CT because of nonspecific heart-pulmonary symptom, noticeable abnormal signs of plain MSCT scanning could suggest the occurrence of pulmonary embolism. (authors)

  7. A two-stage multi-view learning framework based computer-aided diagnosis of liver tumors with contrast enhanced ultrasound images.

    Science.gov (United States)

    Guo, Le-Hang; Wang, Dan; Qian, Yi-Yi; Zheng, Xiao; Zhao, Chong-Ke; Li, Xiao-Long; Bo, Xiao-Wan; Yue, Wen-Wen; Zhang, Qi; Shi, Jun; Xu, Hui-Xiong

    2018-04-04

    With the fast development of artificial intelligence techniques, we proposed a novel two-stage multi-view learning framework for the contrast-enhanced ultrasound (CEUS) based computer-aided diagnosis for liver tumors, which adopted only three typical CEUS images selected from the arterial phase, portal venous phase and late phase. In the first stage, the deep canonical correlation analysis (DCCA) was performed on three image pairs between the arterial and portal venous phases, arterial and delayed phases, and portal venous and delayed phases respectively, which then generated total six-view features. While in the second stage, these multi-view features were then fed to a multiple kernel learning (MKL) based classifier to further promote the diagnosis result. Two MKL classification algorithms were evaluated in this MKL-based classification framework. We evaluated proposed DCCA-MKL framework on 93 lesions (47 malignant cancers vs. 46 benign tumors). The proposed DCCA-MKL framework achieved the mean classification accuracy, sensitivity, specificity, Youden index, false positive rate, and false negative rate of 90.41 ± 5.80%, 93.56 ± 5.90%, 86.89 ± 9.38%, 79.44 ± 11.83%, 13.11 ± 9.38% and 6.44 ± 5.90%, respectively, by soft margin MKL classifier. The experimental results indicate that the proposed DCCA-MKL framework achieves best performance for discriminating benign liver tumors from malignant liver cancers. Moreover, it is also proved that the three-phase CEUS image based CAD is feasible for liver tumors with the proposed DCCA-MKL framework.

  8. Image contrast enhancement of Ni/YSZ anode during the slice-and-view process in FIB-SEM.

    Science.gov (United States)

    Liu, Shu-Sheng; Takayama, Akiko; Matsumura, Syo; Koyama, Michihisa

    2016-03-01

    Focused ion beam-scanning electron microscopy (FIB-SEM) is a widely used and easily operational equipment for three-dimensional reconstruction with flexible analysis volume. It has been using successfully and increasingly in the field of solid oxide fuel cell. However, the phase contrast of the SEM images is indistinct in many cases, which will bring difficulties to the image processing. Herein, the phase contrast of a conventional Ni/yttria stabilized zirconia anode is tuned in an FIB-SEM with In-Lens secondary electron (SE) and backscattered electron detectors. Two accessories, tungsten probe and carbon nozzle, are inserted during the observation. The former has no influence on the contrast. When the carbon nozzle is inserted, best and distinct contrast can be obtained by In-Lens SE detector. This method is novel for contrast enhancement. Phase segmentation of the image can be automatically performed. The related mechanism for different images is discussed. © 2015 The Authors Journal of Microscopy © 2015 Royal Microscopical Society.

  9. Multidetector helical CT plus superparamagnetic iron oxide-enhanced MR imaging for focal hepatic lesions in cirrhotic liver: A comparison with multi-phase CT during hepatic arteriography

    International Nuclear Information System (INIS)

    Yukisawa, Seigo; Okugawa, Hidehiro; Masuya, Yoshio; Okabe, Shinichirou; Fukuda, Hiroyuki; Yoshikawa, Masaharu; Ebara, Masaaki; Saisho, Hiromitsu

    2007-01-01

    The aim of this study was to evaluate multidetector helical computed tomography (MDCT), superparamagnetic iron oxide (SPIO)-enhanced magnetic resonance (MR) imaging, and CT arterial portography (CTAP) and CT during hepatic arteriography (CTHA) for the detection and diagnosis of hepatocellular carcinomas (HCC). This included visual correlations of MDCT and SPIO-MR imaging in the detection of HCC using receiver operating characteristic (ROC) analysis. Twenty-five patients with 57 nodular HCCs were retrospectively analyzed. A total of 200 segments, including 49 segments with 57 HCCs, were reviewed independently by three observers. Each observer read four sets of images (set 1, MDCT; set 2, unenhanced and SPIO-enhanced MR images; set 3, combined MDCT and SPIO-enhanced MR images; set 4, combined CTAP and CTHA). The mean Az values representing the diagnostic accuracy for HCCs of sets 1, 2, 3, and 4 were 0.777, 0.814, 0.849, and 0.911, respectively, and there was no significant difference between sets 3 and 4. The sensitivity of set 4 was significantly higher than those of set 3 for all the lesions and for lesions 10 mm or smaller (p < 0.05); however, for lesions larger than 10 mm, the sensitivities of the two sets were similar. No significant difference in positive predictive value and specificity was observed between set 3 and set 4. Combined MDCT and SPIO-enhanced MR imaging may obviate the need for more invasive CTAP and CTHA for the pre-therapeutic evaluation of patients with HCC more than 10 mm

  10. Comparison of Allergic Adverse Effects and Contrast Enhancement Between Iodixanol and Iopromide

    International Nuclear Information System (INIS)

    Gharekhanloo, Farideh; Torabian, Saadat

    2012-01-01

    Iodinated X-ray contrast media are the most commonly used contrast agents in the world with an annual application of 40-50 million. New non-ionic contrast agents are subdivided into low osmolar agents such as iopromide and iso-osmolar agents such as iodixanol. Regarding different biochemical characteristics, these agents are different in the allergic reactions and contrast enhancement and final lesion conspicuity. This study was carried out to compare allergic adverse effects and contrast enhancement between iodixanol and iopromide. One-hundred and twenty patients who were referred for abdominal CT scan to Besat Hospital were included in this study. Patients were randomly divided into two groups (A and B). Group A received 100 cc iodixanol (300 mgI/mL) and group B received 100 cc iopromide (300 mgI/ml) by power injector. CT examination was performed using Helical CT Scanner (Somatom, Siemens, Germany). Sixty seconds after injection, images were obtained and enhancement of port, liver and aorta were determined. Allergic adverse effects were recorded one hour and up to one week after injection. Iodixanol produced a significantly greater enhancement of the hepatic, aorta and portal vein than iopromide (P < 0.01). Sixty seconds after injection, associated pain and heat sensation were less frequent in iodixanol in comparison with iopromide (P = 0.03). Immediate reactions such as nausea and vomiting were less frequent in iodixanol (P = 0.01). Late skin reactions such as rash was more frequent in iodixanol (P < 0.01). Iodixanol is safe and is better tolerated in the early phase of injection with better contrast enhancement and lesion conspicuity. Mild late skin rash is its disadvantage

  11. Archaeogenetic evidence of ancient nubian barley evolution from six to two-row indicates local adaptation.

    Directory of Open Access Journals (Sweden)

    Sarah A Palmer

    Full Text Available BACKGROUND: Archaeobotanical samples of barley (Hordeum vulgare L. found at Qasr Ibrim display a two-row phenotype that is unique to the region of archaeological sites upriver of the first cataract of the Nile, characterised by the development of distinctive lateral bracts. The phenotype occurs throughout all strata at Qasr Ibrim, which range in age from 3000 to a few hundred years. METHODOLOGY AND FINDINGS: We extracted ancient DNA from barley samples from the entire range of occupancy of the site, and studied the Vrs1 gene responsible for row number in extant barley. Surprisingly, we found a discord between the genotype and phenotype in all samples; all the barley had a genotype consistent with the six-row condition. These results indicate a six-row ancestry for the Qasr Ibrim barley, followed by a reassertion of the two-row condition. Modelling demonstrates that this sequence of evolutionary events requires a strong selection pressure. CONCLUSIONS: The two-row phenotype at Qasr Ibrim is caused by a different mechanism to that in extant barley. The strength of selection required for this mechanism to prevail indicates that the barley became locally adapted in the region in response to a local selection pressure. The consistency of the genotype/phenotype discord over time supports a scenario of adoption of this barley type by successive cultures, rather than the importation of new barley varieties associated with individual cultures.

  12. Non-contrast enhanced magnetic resonance angiography techniques in candidates for kidney transplantation: A comparative study

    International Nuclear Information System (INIS)

    Blankholm, Anne Dorte; Ginnerup-Pedersen, Bodil; Stausbøl-Grøn, Brian; Haislund, Margit; Laustsen, Sussie; Ringgaard, Steffen

    2013-01-01

    Aim: Detailed knowledge of vessel status in potential candidates for kidney transplantation is essential for the surgeon. Contrast enhanced magnetic resonance angiography has previously been used intensively for assessing this, but the discovery that use of gadolinium based contrast agents in magnetic resonance imaging can cause Nephrogenic Systemic Fibrosis in patients suffering from severe kidney disease has lead to renewed interest in non-contrast enhanced magnetic resonance angiography. The aim of this study was to find a non-contrast enhanced magnetic resonance angiography method for preoperative evaluation of the pelvic vessels prior to kidney transplantation, providing a sufficient image quality. Method: In a prospective study we consecutively included 54 patients undergoing examinations prior to kidney transplantation. The patients were examined with the following magnetic resonance angiography sequences: A 2D Time of flight (n = 54), 3D Time of flight (n = 52) patients, 3D Phase Contrast (n = 54), 3D Balanced Steady State Free Precession (n = 52) and a 2D TRiggered Angiography Non-Contrast Enhanced (TRANCE) (a Spin Echo sequence with subtraction) (n = 48). The sequences were evaluated with respect to contrast, diagnostic performance and artefact burden. Results: Evaluating contrast, 3D Phase Contrast was significantly better than 2D Time of flight (p 0.2). The 2D Time of flight was significantly better than the other sequences (p < 0.001) in all cases. The artefact score was lowest for the Phase Contrast images and significantly superior to the 2D Time of flight (p < 0.005). The 2D Time of flight was significantly better than the three other sequences (p < 0.001) in all cases. Conclusion: Non-contrast enhanced magnetic resonance angiography offers a safe preoperative examination for assessment of vessel status before kidney transplantation. A combination of 2D Time of flight and 3D Phase Contrast acquisitions is recommended and can be performed within a

  13. 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...... initially used as Doppler signal enhancers, second-generation microbubble contrast agents are now used with specific contrast harmonic imaging techniques, which benefit from the highly nonlinear behavior of the microbubbles. Contrast-specific modes based on multi-pulse technology are used to perform...... 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...

  14. Strong enhancement of straeming current power by application of two phase flow

    NARCIS (Netherlands)

    Xie, Yanbo; Sherwood, John D.; Shui, Lingling; van den Berg, Albert; Eijkel, Jan C.T.

    2011-01-01

    We show that the performance of a streaming-potential based microfluidic energy conversion system can be strongly enhanced by the use of two phase flow. Injection of gas bubbles into a liquid-filled channel increases both the maximum output power and the energy conversion efficiency. In single-phase

  15. The usefulness of contrast material injection at the dorsal vein of the hand in 64-detecter row helical CT coronary angiography

    International Nuclear Information System (INIS)

    Kawano, Youji; Yakabe, Kazuaki; Urata, Jungo; Eto, Miyuki; Yamaguchi, Hiroichiro

    2011-01-01

    In 315 cases of multi detector row CT (MDCT) coronary angiography contrast material were injected at the dorsal vein of the hand. Early 168 cases were used 80 ml of 370 mgI/ml contrast material and later 147 cases were used 350-480 mgI/kg contrast material. In all cases contrast material was injected by 4 ml/sec with post injection of 30-40 ml physiologic saline. The attenuation of RCA No.3 and other coronary arteries or coronary artery bypass graft (CABG) graft was measured. In later cases the usefulness of above 300 HU was 95.2%. In all cases the usefulness was 92.6%. (author)

  16. Contrast Enhanced US in the Abdomen

    International Nuclear Information System (INIS)

    Chung, Yong Eun; Kim, Ki Whang

    2012-01-01

    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.

  17. Carcinoma of the uterine cervix. High-resolution turbo spin-echo MR imaging with contrast-enhanced dynamic scanning and T2-weighting

    International Nuclear Information System (INIS)

    Abe, Y.; Yamashita, Y.; Namimoto, T.; Takahashi, M.; Katabuchi, H.; Tanaka, N.; Okamura, H.

    1998-01-01

    Purpose: To compare high-resolution contrast-enhanced (Gd-DTPA) dynamic MR imaging with T2-weighted turbo spin-echo (TSE) imaging in the evaluation of uterine cervical carcinoma. Material and Methods: Thirty-two patients with cervical carcinoma underwent MR imaging on a 1.5 T superconductive unit to have the extension of the disease assessed before treatment. A phased-array coil was used in all patients. In 25 patients, surgical confirmation of the diagnosis was obtained after imaging. Radiation therapy was selected for the remaining 7 patients with advanced carcinoma. Qualitative and quantitative image analyses were also performed. Results: The cervical carcinomas showed maximum contrast in the cervical stroma and myometrium in the early dynamic phase. The tumor/cervical-stroma contrast in the early dynamic phase obtained with the T1-weighted TSE technique (contrast-to-noise ratio 22.6) was significantly higher than that obtained in T2-weighted TSE imaging (contrast-to-noise ratio 4.3). In the evaluation of parametrial invasion, the accuracy of T2-weighted imaging was 71.8% and contrast-enhanced dynamic imaging 81.2%. Conclusion: High-resolution contrast-enhanced (Gd-DTPA) dynamic MR imaging in cervical cancer offers improved tumor/cervical-stroma contrast and provides useful information on parametrial invasion. (orig.)

  18. In-line phase-contrast stereoscopic X-ray imaging for radiological purposes: An initial experimental study

    International Nuclear Information System (INIS)

    Siegbahn, E.A.; Coan, P.; Zhou, S.-A.; Bravin, A.; Brahme, A.

    2011-01-01

    We report results from a pilot study in which the in-line propagation-based phase-contrast imaging technique is combined with the stereoscopic method. Two phantoms were imaged at several sample-detector distances using monochromatic, 30 keV, X-rays. High contrast- and spatial-resolution phase-contrast stereoscopic pairs of X-ray images were constructed using the anaglyph approach and a vivid stereoscopic effect was demonstrated. On the other hand, images of the same phantoms obtained with a shorter sample-to-detector distance, but otherwise the same experimental conditions (i.e. the same X-ray energy and absorbed radiation dose), corresponding to the conventional attenuation-based imaging mode, hardly revealed stereoscopic effects because of the lower image contrast produced. These results have confirmed our hypothesis that stereoscopic X-ray images of samples with objects composed of low-atomic-number elements are considerably improved if phase-contrast imaging is used. It is our belief that the high-resolution phase-contrast stereoscopic method will be a valuable new medical imaging tool for radiologists and that it will be of help to enhance the diagnostic capability in the examination of patients in future clinical practice, even though further efforts will be needed to optimize the system performance.

  19. Adaptive multiscale processing for contrast enhancement

    Science.gov (United States)

    Laine, Andrew F.; Song, Shuwu; Fan, Jian; Huda, Walter; Honeyman, Janice C.; Steinbach, Barbara G.

    1993-07-01

    This paper introduces a novel approach for accomplishing mammographic feature analysis through overcomplete multiresolution representations. We show that efficient representations may be identified from digital mammograms within a continuum of scale space and used to enhance features of importance to mammography. Choosing analyzing functions that are well localized in both space and frequency, results in a powerful methodology for image analysis. We describe methods of contrast enhancement based on two overcomplete (redundant) multiscale representations: (1) Dyadic wavelet transform (2) (phi) -transform. Mammograms are reconstructed from transform coefficients modified at one or more levels by non-linear, logarithmic and constant scale-space weight functions. Multiscale edges identified within distinct levels of transform space provide a local support for enhancement throughout each decomposition. We demonstrate that features extracted from wavelet spaces can provide an adaptive mechanism for accomplishing local contrast enhancement. We suggest that multiscale detection and local enhancement of singularities may be effectively employed for the visualization of breast pathology without excessive noise amplification.

  20. Characterizing string-of-pearls colloidal silica by multidetector hydrodynamic chromatography and comparison to multidetector size-exclusion chromatography, off-line multiangle static light scattering, and transmission electron microscopy.

    Science.gov (United States)

    Brewer, Amandaa K; Striegel, André M

    2011-04-15

    The string-of-pearls-type morphology is ubiquitous, manifesting itself variously in proteins, vesicles, bacteria, synthetic polymers, and biopolymers. Characterizing the size and shape of analytes with such morphology, however, presents a challenge, due chiefly to the ease with which the "strings" can be broken during chromatographic analysis or to the paucity of information obtained from the benchmark microscopy and off-line light scattering methods. Here, we address this challenge with multidetector hydrodynamic chromatography (HDC), which has the ability to determine, simultaneously, the size, shape, and compactness and their distributions of string-of-pearls samples. We present the quadruple-detector HDC analysis of colloidal string-of-pearls silica, employing static multiangle and quasielastic light scattering, differential viscometry, and differential refractometry as detection methods. The multidetector approach shows a sample that is broadly polydisperse in both molar mass and size, with strings ranging from two to five particles, but which also contains a high concentration of single, unattached "pearls". Synergistic combination of the various size parameters obtained from the multiplicity of detectors employed shows that the strings with higher degrees of polymerization have a shape similar to the theory-predicted shape of a Gaussian random coil chain of nonoverlapping beads, while the strings with lower degrees of polymerization have a prolate ellipsoidal shape. The HDC technique is contrasted experimentally with multidetector size-exclusion chromatography, where, even under extremely gentle conditions, the strings still degraded during analysis. Such degradation is shown to be absent in HDC, as evidenced by the fact that the molar mass and radius of gyration obtained by HDC with multiangle static light scattering detection (HDC/MALS) compare quite favorably to those determined by off-line MALS analysis under otherwise identical conditions. The

  1. Contrast-enhanced 3D MR angiography of the chest and abdomen with breath-holding using phase reordering

    International Nuclear Information System (INIS)

    Amanuma, Makoto; Sugimoto, Eiichi; Enomoto, Kyoko; Watabe, Tsuneya; Heshiki, Atsuko; Hirata, Hisashi; Kimura, Toshihiko; Takizawa, Osamu.

    1995-01-01

    This report presents the feasibility of phase-reordered contrast-enhanced three-dimensional MR angiography in 32 consecutive patients with vascular abnormalities in the chest and abdomen. To suppress motion artifacts due to respiratory corruption, a phase-reordering technique was introduced so that the low frequency components of the phase data were obtained first during the imaging period. Image quality and degree of motion suppression were assessed by four radiologists independently without information on breath-holding time. Abnormalities were detected in 30 cases (93.8%), and their extent was correctly assessed in 28 cases (87.5%). More confident assessment was possible in abnormalities of the pulmonary vessels and thoracic aorta than in those of the abdominal aorta and portal venous system. With phase reordering, more than 20 seconds of breath-holding ensured image quality sufficient to correctly assess the vascular abnormalities. While this technique is easy and requires only single breath-holding, it can provide excellent MRA without slice-to-slice spatial misregistration. (author)

  2. Role of (18)F-fluorodeoxyglucose positron emission tomography/computed tomography in diagnosis and management of pancreatic cancer; comparison with multidetector row computed tomography, magnetic resonance imaging and endoscopic ultrasonography.

    Science.gov (United States)

    Ergul, N; Gundogan, C; Tozlu, M; Toprak, H; Kadıoglu, H; Aydin, M; Cermik, T F

    2014-01-01

    We aimed to analyze the contribution of (18)F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT) imaging to the diagnosis and management of pancreatic cancer compared with multidetector row computed tomography (MDCT), magnetic resonance imaging (MRI) and endoscopic ultrasonography (EUS). We retrospectively scanned the data of 52 patients who were referred for FDG PET/CT imaging for evaluation of pancreatic lesions greater than 10mm. The diagnostic performances of 4 imaging methods and the impact of PET/CT on the management of pancreatic cancer were defined. Pancreatic adenocarcinoma was diagnosed in 33 of 52 patients (63%), 15 patients had benign diseases of pancreas (29%), and 4 patients were normal (8%). Sensitivity and NPV of EUS and PET/CT were equal (100%) and higher than MDCT and MRI. Specificity, PPV and NPV of PET/CT were significantly higher than MDCT. However, sensitivities of two imaging methods were not significantly different. There was no significant difference between PET/CT and MRI and EUS for these values. When the cut-off value of SUVmax was 3.2, the most effective sensitivity and specificity values were obtained. PET/CT contributed to the management of pancreatic cancer in 30% of patients. FDG PET/CT is a valuable imaging method for the diagnosis and management of pancreatic cancer, especially when applied along with EUS as first line diagnostic tools. Copyright © 2013 Elsevier España, S.L. and SEMNIM. All rights reserved.

  3. Preoperative staging of esophageal carcinoma with multidetector CT and virtual endoscopy

    International Nuclear Information System (INIS)

    Onbas, Omer; Eroglu, Atilla; Kantarci, Mecit; Polat, Pinar; Alper, Fatih; Karaoglanoglu, Nurettin; Okur, Adnan

    2006-01-01

    Purpose: The aim of this study was to assess the accuracy of multidetector computed tomography (MDCT), including virtual endoscopy (VE) for detection, precise localization, preoperative evaluation and staging of esophageal cancer (EC) by comparison with surgical and histopathological findings. Materials and methods: Between September 2003 and April 2005, 44 patients with histologically proven EC underwent MDCT and VE. Among 44 patients, the findings were confirmed in 24 at surgery. The accuracy of three-dimensional MDCT for detection, localization, and staging of EC was determined, and compared with surgical finding and histopathology. Results: The overall accuracy of three-dimensional multidetector row CT for detection of EC was 100% (24/24). MDCT staging was correct in 20 patients (83.3%). The T parameter was correctly assessed in 22 (91.7%) cases (understaged in 1 and overstaged in 1). The N parameter was correctly evaluated in 20 (83.4%) patients (understaged in 2 and overstaged in 2). The overall accuracy of VE for the morphologic classification of EC was 81.5%. Conclusions: Three-dimensional MDCT, along with VE is a promising method for preoperative evaluation and staging of EC. Although accuracy in N staging remains low in comparison to PET, it provides a larger amount of diagnostic and staging information

  4. 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...

  5. Statistical iterative reconstruction for streak artefact reduction when using multidetector CT to image the dento-alveolar structures.

    Science.gov (United States)

    Dong, J; Hayakawa, Y; Kober, C

    2014-01-01

    When metallic prosthetic appliances and dental fillings exist in the oral cavity, the appearance of metal-induced streak artefacts is not avoidable in CT images. The aim of this study was to develop a method for artefact reduction using the statistical reconstruction on multidetector row CT images. Adjacent CT images often depict similar anatomical structures. Therefore, reconstructed images with weak artefacts were attempted using projection data of an artefact-free image in a neighbouring thin slice. Images with moderate and strong artefacts were continuously processed in sequence by successive iterative restoration where the projection data was generated from the adjacent reconstructed slice. First, the basic maximum likelihood-expectation maximization algorithm was applied. Next, the ordered subset-expectation maximization algorithm was examined. Alternatively, a small region of interest setting was designated. Finally, the general purpose graphic processing unit machine was applied in both situations. The algorithms reduced the metal-induced streak artefacts on multidetector row CT images when the sequential processing method was applied. The ordered subset-expectation maximization and small region of interest reduced the processing duration without apparent detriments. A general-purpose graphic processing unit realized the high performance. A statistical reconstruction method was applied for the streak artefact reduction. The alternative algorithms applied were effective. Both software and hardware tools, such as ordered subset-expectation maximization, small region of interest and general-purpose graphic processing unit achieved fast artefact correction.

  6. Diagnostic Accuracy of Dynamic Contrast Enhanced Magnetic Resonance Imaging in Characterizing Lung Masses

    Science.gov (United States)

    Inan, Nagihan; Arslan, Arzu; Donmez, Muhammed; Sarisoy, Hasan Tahsin

    2016-01-01

    Background Imaging plays a critical role not only in the detection, but also in the characterization of lung masses as benign or malignant. Objectives To determine the diagnostic accuracy of dynamic magnetic resonance imaging (MRI) in the differential diagnosis of benign and malignant lung masses. Patients and Methods Ninety-four masses were included in this prospective study. Five dynamic series of T1-weighted spoiled gradient echo (FFE) images were obtained, followed by a T1-weighted FFE sequence in the late phase (5th minutes). Contrast enhancement patterns in the early (25th second) and late (5th minute) phase images were evaluated. For the quantitative evaluation, signal intensity (SI)-time curves were obtained and the maximum relative enhancement, wash-in rate, and time-to-peak enhancement of masses in both groups were calculated. Results The early phase contrast enhancement patterns were homogeneous in 78.2% of the benign masses, while heterogeneous in 74.4% of the malignant tumors. On the late phase images, 70.8% of the benign masses showed homogeneous enhancement, while most of the malignant masses showed heterogeneous enhancement (82.4%). During the first pass, the maximum relative enhancement and wash-in rate values of malignant masses were significantly higher than those of the benign masses (P = 0.03 and 0.04, respectively). The cutoff value at 15% yielded a sensitivity of 85.4%, specificity of 61.2%, and positive predictive value of 68.7% for the maximum relative enhancement. Conclusion Contrast enhancement patterns and SI-time curve analysis of MRI are helpful in the differential diagnosis of benign and malignant lung masses. PMID:27703654

  7. Recent advances in contrast-enhanced magnetic resonance angiography

    International Nuclear Information System (INIS)

    Meaney, J.F.M.; Goyen, M.

    2007-01-01

    Magnetic resonance angiography (MRA) provides a means of visualizing vascular structures noninvasively and is increasingly replacing conventional X-ray angiography in routine use. Contrast-enhanced MRA (CE-MRA), in which gadolinium contrast agents are used to shorten the T1 relaxation, offers increased resolution and higher signal-to-noise ratio compared with earlier flow-dependent [time-of-flight (TOF) or phase-contrast (PC)] techniques. Currently available contrast agents differ in their ability to lower T1 values, and hence the choice of contrast agent is an important consideration in the successful use of CE-MRA. Gadofosveset trisodium (Vasovist, Bayer Schering Pharma AG, Berlin, Germany) is the first of a new class of intravascular contrast agents. This agent is extensively (approximately 85%) and reversibly bound to human serum albumin and is retained within the vasculature thus allowing steady-state imaging to be perform-ed. An additional benefit is that gado0fosveset offers higher relaxivity compared with other contrast agents, thus giving a lower blood T1 values which also makes it ideal for first-pass imaging. Clinical trials have consistently shown that gadofosveset enhanced MRA is more sensitive, specific and accurate than time-of-flight MRA, gives fewer uninterpretable scans and affords greater diagnostic confidence. Intravascular contrast agents such as gadofosveset, therefore, offer the potential for improved vascular imaging. (orig.)

  8. Contrast-enhanced ultrasound imaging and in vivo circulatory kinetics with low-boiling-point nanoscale phase-change perfluorocarbon agents.

    Science.gov (United States)

    Sheeran, Paul S; Rojas, Juan D; Puett, Connor; Hjelmquist, Jordan; Arena, Christopher B; Dayton, Paul A

    2015-03-01

    Many studies have explored phase-change contrast agents (PCCAs) that can be vaporized by an ultrasonic pulse to form microbubbles for ultrasound imaging and therapy. However, few investigations have been published on the utility and characteristics of PCCAs as contrast agents in vivo. In this study, we examine the properties of low-boiling-point nanoscale PCCAs evaluated in vivo and compare data with those for conventional microbubbles with respect to contrast generation and circulation properties. To do this, we develop a custom pulse sequence to vaporize and image PCCAs using the Verasonics research platform and a clinical array transducer. Results indicate that droplets can produce contrast enhancement similar to that of microbubbles (7.29 to 18.24 dB over baseline, depending on formulation) and can be designed to circulate for as much as 3.3 times longer than microbubbles. This study also reports for the first time the ability to capture contrast washout kinetics of the target organ as a measure of vascular perfusion. Copyright © 2015 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

  9. The multidetector computed tomography angiography (MDCTA) in the diagnosis of splenic artery aneurysm and pseudoaneurysm

    International Nuclear Information System (INIS)

    Saba, Luca; Mallarini, Giorgio; Anzidei, Michele; Lucatelli, Pierleone

    2011-01-01

    Splenic artery aneurysm is the most frequent visceral artery aneurysm and rupture of the aneurysm is associated with a high mortality rate. It is important to discriminate between a true aneurysm and a pseudoaneurysm that may be caused by pancreatitis, iatrogenic and postoperative causes, trauma and peptic ulcer disease. Multidetector-row CT angiography (MDCTA) allows detailed visualization of the vascular anatomy and may allow identification of aneurysms and pseudoaneurysms that affect the splenic artery. The objective of this article is to provide a review of the general characteristics of splenic artery aneurysms and pseudoaneurysms and to describe the findings of MDCTA

  10. The multidetector computed tomography angiography (MDCTA) in the diagnosis of splenic artery aneurysm and pseudoaneurysm

    Energy Technology Data Exchange (ETDEWEB)

    Saba, Luca; Mallarini, Giorgio (Dept. of Radiology, Azienda Ospedaliero Universitaria (AOU), Cagliari (Italy)), email: lucasaba@tiscali.it; Anzidei, Michele; Lucatelli, Pierleone (Dept. of Radiological Sciences, Univ. of Rome La Sapienza, Rome (Italy))

    2011-06-15

    Splenic artery aneurysm is the most frequent visceral artery aneurysm and rupture of the aneurysm is associated with a high mortality rate. It is important to discriminate between a true aneurysm and a pseudoaneurysm that may be caused by pancreatitis, iatrogenic and postoperative causes, trauma and peptic ulcer disease. Multidetector-row CT angiography (MDCTA) allows detailed visualization of the vascular anatomy and may allow identification of aneurysms and pseudoaneurysms that affect the splenic artery. The objective of this article is to provide a review of the general characteristics of splenic artery aneurysms and pseudoaneurysms and to describe the findings of MDCTA

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

    International Nuclear Information System (INIS)

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

    2010-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2010-11-15

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

  13. MDCT angiography of the pulmonary arteries: intravascular contrast enhancement does not depend on iodine concentration when injecting equal amounts of iodine at standardized iodine delivery rates

    International Nuclear Information System (INIS)

    Keil, S.; Plumhans, C.; Behrendt, F.F.; Das, M.; Muehlenbruch, G.; Mahnken, A.H.; Guenther, R.W.; Stanzel, S.; Seidensticker, P.; Knackstedt, C.; Wildberger, J.E.

    2008-01-01

    To compare the impact of iodine concentration using two different contrast materials (CM) at standardized iodine delivery rate (IDR) and overall iodine load in 16-multidetector-row-CT-angiography (MDCTA) of the pulmonary arteries of 192 patients with known or suspected pulmonary embolism. One hundred three patients (group A) received 148 ml of a CM containing 300 mg iodine/ml (Ultravist 300 trademark, BayerScheringPharma) at a flow rate of 4.9 ml/s. Eighty-nine patients (group B) received 120 ml of a CM with a concentration of 370 mg iodine/ml (Ultravist370 trademark) at a flow rate of 4.0 ml/s, resulting in a standardized IDR (∝1.5 gI/s) and the same overall amount of iodine (44.4 g). Both CM injections were followed by a saline chaser. Mean density values were determined in the pulmonary trunk, the ascending and the descending aorta, respectively. Applying repeated-measures ANOVA, no statistically significant differences between both MDCTA protocols were found (p=0.5790): the mean density in the pulmonary trunk was 355±116 Hounsfield Units (group A) and 358±115 (group B). The corresponding values for the ascending and descending aorta were 295±79 (group A) and 284±65 (group B) as well as 272±71 and 262±70. In conclusion, the use of standardized IDR and overall iodine load provides comparable intravascular CM density in pulmonary 16-MDCTA for delivering contrast materials with different iodine concentrations. (orig.)

  14. 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.

  15. Multiplanar and two-dimensional imaging of central airway stenting with multidetector computed tomography

    Directory of Open Access Journals (Sweden)

    Ozgul Mehmet

    2012-08-01

    Full Text Available Abstract Background Multidetector computed tomography (MDCT provides guidance for primary screening of the central airways. The aim of our study was assessing the contribution of multidetector computed tomography- two dimensional reconstruction in the management of patients with tracheobronchial stenosis prior to the procedure and during a short follow up period of 3 months after the endobronchial treatment. Methods This is a retrospective study with data collected from an electronic database and from the medical records. Patients evaluated with MDCT and who had undergone a stenting procedure were included. A Philips RSGDT 07605 model MDCT was used, and slice thickness, 3 mm; overlap, 1.5 mm; matrix, 512x512; mass, 90 and kV, 120 were evaluated. The diameters of the airways 10 mm proximal and 10 mm distal to the obstruction were measured and the stent diameter (D was determined from the average between D upper and D lower. Results Fifty-six patients, 14 (25% women and 42 (75% men, mean age 55.3 ± 13.2 years (range: 16-79 years, were assessed by MDCT and then treated with placement of an endobronchial stent. A computed tomography review was made with 6 detector Philips RSGDT 07605 multidetector computed tomography device. Endobronchial therapy was provided for the patients with endoluminal lesions. Stents were placed into the area of stenosis in patients with external compression after dilatation and debulking procedures had been carried out. In one patient the migration of a stent was detected during the follow up period by using MDCT. Conclusions MDCT helps to define stent size, length and type in patients who are suitable for endobronchial stinting. This is a non-invasive, reliable method that helps decisions about optimal stent size and position, thus reducing complications.

  16. Evaluation of retrospectively ECG-gated 4-row multidetector CT in patients planned for minimal invasive coronary artery bypass grafting; Die EKG-getriggerte 4-Zeilen-Spiral-CT des Herzens in der praeoperativen Bildgebung vor minimalinvasiver koronarer Bypass-Operation

    Energy Technology Data Exchange (ETDEWEB)

    Begemann, P.G.C.; Ittrich, H.; Koops, A.; Adam, G.; Weber, C. [Klinik und Poliklinik fuer Diagnostische und Interventionelle Radiologie, Radiologisches Zentrum, Universitaetsklinikum, Hamburg (Germany); Arnold, M.; Detter, C.; Boehm, D.H.; Reichenspurner, H. [Universitaetsklinikum Hamburg-Eppendorf, Herzzentrum, Herz und Gefaesschirurgie, Hamburg (Germany)

    2005-08-01

    Purpose: Minimal invasive direct coronary artery bypass grafting (MIDCAB) or off-pump coronary artery bypass grafting (OPCAB) on the beating heart with full or mini-sternotomy are becoming more common in coronary bypass surgery of the left anterior descending (LAD). In the decision, which surgical approach (MIDCAB, OPCAB or conventional surgery with cardiopulmonary bypass) will be best used, knowledge of the anatomical field is of major importance. The aim of the study was to evaluate retrospective ECG-gated 4-row multidetector CT (MDCT) in patients planned for MIDCAB as additional imaging to coronary angiography. Material and methods: The study included 25 consecutive patients. MSCT was performed as unenhanced (collimation 4 x 2.5 mm) and contrast-enhanced examination (140-170 ml, 300 mg Iodine/ml, collimation 4 x 1 mm). The evaluation included presence of LAD calcifications, distance of LAD and left internal mammarian artery (LIMA), coursek of LAD and LIMA, the presence or absence of bridging through myocardium or epicardial fat and the presence of pleural fibrosis. The MDCT results were correlated with intra-operative findings. Results: All MDCTs could be assessed with reference to the demands. In 20/25 operations, MDCT had direct influence as to the selection of the surgical approach (11 MIDCAB, 7 OPCAB with mini-sternotomy and 5 with full sternotomy, 2 conventional surgeries). The distance of LAD and LIMA varied from 0.9 to 4.5 cm in MDCT. As to calcifications, 3/25 correlated patients had calcifications and 10 patients had no calcifications in the middle LAD. Seven patients had intraoperative fibrosis of the vessel wall without calcification of the middle LAD, which could not be detected with MDCT. Another 5 patients had single calcified plaques in the middle LAD, 4 of these had a fibrosis of the vessel and 1 had a normal vessel at surgery. In these cases, the anastomosis was done between the calcified plaques. No myocardial bridging was detected by MDCT and

  17. Initial studies of synchrotron radiation phase-contrast imaging in the field of medicine

    International Nuclear Information System (INIS)

    Chen Shaoliang; Zhang Xi; Peng Yifeng; Li Beilei; Cheng Aiping; Zhu Peiping; Yuan Xiqing; Huang Wanxia

    2010-01-01

    Recently,research on using X-ray phase information in medicine has been growing remarkably fast. Phase-contrast imaging with synchrotron radiation can reveal inner soft tissues such as tendons, cartilage, ligaments, adipose tissue, vessels and nerves without a contrast agent. We have visualized the liver, bile duct, lung, kidney, stomach and intestine, heart, blood vessel, bone and arthrosis, and tumor tissues using 'in-line' phase contrast imaging and diffraction-enhanced imaging. It is seen that the synchrotron radiation graphs show much higher resolution. This method is especially suitable for studying soft tissue structure and blood vessels. (authors)

  18. Outcomes of single-row and double-row arthroscopic rotator cuff repair: a systematic review.

    Science.gov (United States)

    Saridakis, Paul; Jones, Grant

    2010-03-01

    Arthroscopic rotator cuff repair is a common procedure that is gaining wide acceptance among orthopaedic surgeons because it is less invasive than open repair techniques. However, there is little consensus on whether to employ single-row or double-row fixation. The purpose of the present study was to systematically review the English-language literature to see if there is a difference between single-row and double-row fixation techniques in terms of clinical outcomes and radiographic healing. PubMed, the Cochrane Central Register of Controlled Trials, and EMBASE were reviewed with the terms "arthroscopic rotator cuff," "single row repair," and "double row repair." The inclusion criteria were a level of evidence of III (or better), an in vivo human clinical study on arthroscopic rotator cuff repair, and direct comparison of single-row and double-row fixation. Excluded were technique reports, review articles, biomechanical studies, and studies with no direct comparison of arthroscopic rotator cuff repair techniques. On the basis of these criteria, ten articles were found, and a review of the full-text articles identified six articles for final review. Data regarding demographic characteristics, rotator cuff pathology, surgical techniques, biases, sample sizes, postoperative rehabilitation regimens, American Shoulder and Elbow Surgeons scores, University of California at Los Angeles scores, Constant scores, and the prevalence of recurrent defects noted on radiographic studies were extracted. Confidence intervals were then calculated for the American Shoulder and Elbow Surgeons, University of California at Los Angeles, and Constant scores. Quality appraisal was performed by the two authors to identify biases. There was no significant difference between the single-row and double-row groups within each study in terms of postoperative clinical outcomes. However, one study divided each of the groups into patients with small-to-medium tears ( or = 3 cm in length), and the

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

    International Nuclear Information System (INIS)

    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

    2004-01-01

    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

  20. Low-tube-voltage selection for non-contrast-enhanced CT: Comparison of the radiation dose in pediatric and adult phantoms.

    Science.gov (United States)

    Shimonobo, Toshiaki; Funama, Yoshinori; Utsunomiya, Daisuke; Nakaura, Takeshi; Oda, Seitaro; Kiguchi, Masao; Masuda, Takanori; Sakabe, Daisuke; Yamashita, Yasuyuki; Awai, Kazuo

    2016-01-01

    We used pediatric and adult anthropomorphic phantoms to compare the radiation dose of low- and standard tube voltage chest and abdominal non-contrast-enhanced computed tomography (CT) scans. We also discuss the optimal low tube voltage for non-contrast-enhanced CT. Using a female adult- and three differently-sized pediatric anthropomorphic phantoms we acquired chest and abdominal non-contrast-enhanced scans on a 320-multidetector CT volume scanner. The tube voltage was set at 80-, 100-, and 120 kVp. The tube current was automatically assigned on the CT scanner in response to the set image noise level. On each phantom and at each tube voltage we measured the surface and center dose using high-sensitivity metal-oxide-semiconductor field-effect transistor detectors. The mean surface dose of chest and abdominal CT scans in 5-year olds was 4.4 and 5.3 mGy at 80 kVp, 4.5 and 5.4 mGy at 100 kV, and 4.0 and 5.0 mGy at 120 kVp, respectively. These values were similar in our 3-pediatric phantoms (p > 0.05). The mean surface dose in the adult phantom increased from 14.7 to 19.4 mGy for chest- and from 18.7 to 24.8 mGy for abdominal CT as the tube voltage decreased from 120 to 80 kVp (p voltage and the low tube voltage technique can be used for non-contrast-enhanced chest- and abdominal scanning. Copyright © 2015 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

  1. Recent advances in synchrotron-based hard x-ray phase contrast imaging

    International Nuclear Information System (INIS)

    Liu, Y; Nelson, J; Andrews, J C; Pianetta, P; Holzner, C

    2013-01-01

    Ever since the first demonstration of phase contrast imaging (PCI) in the 1930s by Frits Zernike, people have realized the significant advantage of phase contrast over conventional absorption-based imaging in terms of sensitivity to ‘transparent’ features within specimens. Thus, x-ray phase contrast imaging (XPCI) holds great potential in studies of soft biological tissues, typically containing low Z elements such as C, H, O and N. Particularly when synchrotron hard x-rays are employed, the favourable brightness, energy tunability, monochromatic characteristics and penetration depth have dramatically enhanced the quality and variety of XPCI methods, which permit detection of the phase shift associated with 3D geometry of relatively large samples in a non-destructive manner. In this paper, we review recent advances in several synchrotron-based hard x-ray XPCI methods. Challenges and key factors in methodological development are discussed, and biological and medical applications are presented. (paper)

  2. Recent advances in synchrotron-based hard x-ray phase contrast imaging

    Science.gov (United States)

    Liu, Y.; Nelson, J.; Holzner, C.; Andrews, J. C.; Pianetta, P.

    2013-12-01

    Ever since the first demonstration of phase contrast imaging (PCI) in the 1930s by Frits Zernike, people have realized the significant advantage of phase contrast over conventional absorption-based imaging in terms of sensitivity to ‘transparent’ features within specimens. Thus, x-ray phase contrast imaging (XPCI) holds great potential in studies of soft biological tissues, typically containing low Z elements such as C, H, O and N. Particularly when synchrotron hard x-rays are employed, the favourable brightness, energy tunability, monochromatic characteristics and penetration depth have dramatically enhanced the quality and variety of XPCI methods, which permit detection of the phase shift associated with 3D geometry of relatively large samples in a non-destructive manner. In this paper, we review recent advances in several synchrotron-based hard x-ray XPCI methods. Challenges and key factors in methodological development are discussed, and biological and medical applications are presented.

  3. MR imaging of the pulmonary vasculature - an update

    Energy Technology Data Exchange (ETDEWEB)

    Pedersen, Mark R.; Fisher, Mark T. [University of Iowa, Department of Radiology, Carver College of Medicine, Iowa City, Iowa (United States); Beek, Edwin J.R. van [University of Iowa, Department of Radiology, Carver College of Medicine, Iowa City, Iowa (United States); University of Iowa Hospitals and Clinics, JPP 3895, Department of Radiology, Iowa City, Iowa (United States)

    2006-06-15

    Although the advent of multi-detector row computed tomography (CT) angiography has been at the heart of improving the diagnostic management of pulmonary vascular disease, MR technology has also moved forward. This review outlines the current state of affairs of MR techniques for the assessment of pulmonary vascular diseases such as pulmonary hypertension, pulmonary arteritis and arteriovenous malformations. It highlights the main areas of MR angiography and MR perfusion imaging and discusses novel methods, such as non-contrast enhanced direct thrombus imaging, and will discuss its merits in the context of other diagnostic modalities. (orig.)

  4. Volumetric dynamic contrast enhanced Computed Tomography (DCE-CT) for preoperative assessment of the vascularity of spinal metastases

    DEFF Research Database (Denmark)

    Lauridsen, Carsten Ammitzbøl

    Purpose To investigate the feasibility of measuring and grading the vascularity of spinal metastases using dynamic contrast enhanced CT (DCE-CT). Materials and methods Prior to surgical treatment of symptomatic metastatic spinal cord compression, 20 patients were examined using DCE-CT. The 320......–detector row CT scanner allowed a volumetric acquisition over a range of 16 cm, covering three to four vertebrae. Image analysis was performed at a dedicated workstation, encompassing quantitative and qualitative measurement of the arterial flow (AF) in mL/min/100mL of the vertebrae. The perfusion values...... were analysed using a single input, maximum slope model. The AF assessed by DCE-CT of affected and non-affected vertebrae will be compared, and furthermore, the correlation between AF and intraoperative blood loss will be examined. Results Preliminary results for 5 patients: In two patients the AF...

  5. Evaluation of radiation dose in 64-row whole-body CT of multiple injured patients compared to 4-row CT; Evaluation der Strahlendosis bei Polytrauma-CT-Untersuchungen eines 64-Zeilen-CT im Vergleich zur 4-Zeilen-CT

    Energy Technology Data Exchange (ETDEWEB)

    Harrieder, A.; Geyer, L.L.; Koerner, M.; Deak, Z.; Wirth, S.; Reiser, M.; Linsenmaier, U. [Ludwig-Maximilians-Univ. Muenchen (Germany). Inst. fuer Klinische Radiologie

    2012-05-15

    Purpose: To evaluate radiation exposure in whole-body CT (WBCT) of multiple injured patients comparing 4-row multidetector computed tomography (MDCT) to 64-row MDCT. Materials and Methods: 200 WBCT studies were retrospectively evaluated: 92 4-row MDCT scans and 108 64-row MDCT scans. Each CT protocol was optimized for the particular CT system. The scan length, CT dose index (CTDI), and dose length product (DLP) were recorded and analyzed for radiation exposure. The mean effective dose was estimated based on conversion factors. Student's t-test was used for statistical analysis. Results: The mean CTDI{sub vol} values (mGy) of the thorax and abdomen were significantly reduced with 64-row MDCT (10.2 {+-} 2.5 vs. 11.4 {+-} 1.4, p < 0.001; 14.2 {+-} 3.7 vs. 16.1 {+-} 1.7, p < 0.001). The DLP values (mGy x cm) of the head and thorax were significantly increased with 64-row MDCT (1305.9 {+-} 201.1 vs. 849.8 {+-} 90.9, p < 0,001; 504.4 {+-} 134.4 vs. 471.5 {+-} 74.1, p = 0.030). The scan lengths (mm) were significantly increased with 64-row MDCT: head 223.6 {+-} 35.8 vs. 155.5 {+-} 12.3 (p < 0.001), thorax 427.4 {+-} 44.5 vs. 388.3 {+-} 57.5 (p < 0.001), abdomen 520.3 {+-} 50.2 vs. 490.8 {+-} 51.6 (p < 0.001). The estimated mean effective doses (mSv) were 22.4 {+-} 2.6 (4-row MDCT) and 24.1 {+-} 4.6 (64-row MDCT; p = 0.001), resulting in a percentage increase of 8 %. Conclusion: The radiation dose per slice of the thorax and abdomen can be significantly decreased by using 64-row MDCT. Due to the technical advances of modern 64-row MDCT systems, the scan field can be adapted to the clinical demands and, if necessary, enlarged without time loss. As a result, the estimated mean effective dose might be increased in WBCT. (orig.)

  6. 64-section multidetector CT of the upper abdomen: optimization of a saline chaser injection protocol for improved vascular and parenchymal contrast enhancement

    Energy Technology Data Exchange (ETDEWEB)

    Marin, Daniele [Duke University Medical Center, Department of Radiology, Durham, NC (United States); University of Rome Sapienza, Department of Radiological Sciences, Rome (Italy); Nelson, Rendon C. [Duke University Medical Center, Department of Radiology, Durham, NC (United States); Guerrisi, Antonino; Passariello, Roberto; Catalano, Carlo [University of Rome Sapienza, Department of Radiological Sciences, Rome (Italy); Barnhart, Huiman [Duke University Medical Center, Department of Biostatistics and Bioinformatics, Durham, NC (United States); Schindera, Sebastian T. [University Hospital of Bern, Institute for Diagnostic, Interventional and Pediatric Radiology, Bern (Switzerland)

    2011-09-15

    To prospectively investigate the effect of varying the injection flow rates of a saline chaser on vascular and parenchymal contrast enhancement during abdominal MDCT. 100 consecutive patients were randomly assigned to four injection protocols. A fixed dose of contrast medium was administered followed by no saline (Protocol A) or 50 mL of saline at 2, 4, or 8 mL/s (Protocols B, C, and D). Peak, time-to-peak, and duration of 90% peak enhancement were determined for aorta, pancreas, and liver. Aortic peak enhancement was significantly higher for Protocol D (369.5 HU) compared with Protocols A and B (332.9 HU and 326.0 HU, respectively; P < 0.05). Pancreatic peak enhancement was significantly higher for Protocols C and D (110.6 HU and 110.9 HU, respectively) compared to Protocol A (92.5 HU; P < 0.05). Aortic and pancreatic time-to-peak enhancement occurred significantly later for Protocol D compared with Protocol A (42.8 s vs. 36.1 s [P < 0.001] and 49.7 s vs. 45.3 s [P = 0.003]). Injecting a saline chaser at high flow rates yields significantly higher peak aortic and pancreatic enhancement, with a slight longer time-to-peak enhancement. (orig.)

  7. Non-enhanced CT versus contrast-enhanced CT in integrated PET/CT studies for nodal staging of rectal cancer

    International Nuclear Information System (INIS)

    Tateishi, Ukihide; Maeda, Tetsuo; Morimoto, Tsuyoshi; Miyake, Mototaka; Arai, Yasuaki; Kim, E.E.

    2007-01-01

    The purpose of the present study was to determine the diagnostic accuracy of non-enhanced CT and contrast-enhanced CT in integrated PET/CT studies for preoperative nodal staging of rectal cancer. Retrospective analysis was performed in 53 patients with pathologically proven rectal cancer who had been referred for preoperative staging. All patients underwent integrated PET/CT consisting of non-enhanced and contrast-enhanced CT followed by whole-body fluorine-18-fluorodeoxyglucose ([ 18 F]FDG) PET. Both non-enhanced and contrast-enhanced PET/CT images were evaluated separately by two observers in consensus. The reference standard was histopathologic results. For nodal staging of rectal cancer, we compared diagnostic accuracy on a per-patient basis between the two modalities. Nodal staging was correctly determined with non-enhanced studies in 37 patients (70%) and with contrast-enhanced studies in 42 patients (79%). On a per-patient basis, sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of regional lymph node staging were 85%, 68%, 83%, 72%, and 79%, respectively, with contrast-enhanced studies, and 85%, 42%, 73%, 62%, and 70%, respectively, with non-enhanced studies. The difference in the accuracy of nodal staging between the two modalities was not significant (p = 0.063). Compared with non-enhanced studies, contrast-enhanced studies determined more correctly the status of pararectal lymph nodes (p 0.002), internal iliac lymph nodes (p = 0.004), and obturator lymph nodes (p < 0.0001). Contrast-enhanced PET/CT is superior to non-enhanced PET/CT for precise definition of regional nodal status in rectal cancer. (orig.)

  8. A numerical approach to the simulation of one-phase and two phase reactor coolant flow around nuclear fuel spacers

    International Nuclear Information System (INIS)

    Stosic, Z.V.; Stevanovic, V.D.

    2001-01-01

    A methodology for the simulation and analysis of one-phase and two-phase coolant flows around one or a row of spacers is presented. It is based on the multidimensional two-fluid mass, momentum and energy balance equations and application of adequate turbulence models. Necessary closure laws for interfacial transfer processes are presented. The stated general approach enables simulation and analyses of reactor coolant flow around spacers on different scale levels of the rod bundle geometry: detailed modelling of coolant flow around spacers and investigation of the influence of spacer's geometry on the coolant thermal-hydraulics, as well as prediction of global thermal-hydraulic parameters within the whole rod bundle with the investigation of the influence of rows of spacers on the bulk thermal-hydraulic processes. Sample problems are included illustrating these different modelling approaches. (author)

  9. Multiphasic contrast-enhanced CT and MRI findings of adult mesoblastic nephroma: A report of two cases

    Directory of Open Access Journals (Sweden)

    Yuqin Ding

    2013-01-01

    Full Text Available Mesoblastic nephroma (MN presenting in an adult is extremely rare. The computed tomography (CT and magnetic resonance imaging (MRI features of this tumor in adulthood have not been widely reported. We present two additional cases of adult MN and describe the multiphasic contrast-enhanced CT and MRI findings.

  10. Comparison of calcium scoring with 4-multidetector computed tomography (4-MDCT) and 64-MDCT: a phantom study.

    Science.gov (United States)

    Serafin, Zbigniew; Rusak, Grazyna; Strześniewski, Piotr; Laskowska, Katarzyna; Lasek, Władysław

    2012-01-01

    To determine differences in coronary artery calcium (CAC) measurement performed with the use of 2 generations of multidetector computed tomography (CT) scanners of the same manufacturer. Agatston Score (AS) and calcium mass (CM) were measured with a 4-row scanner (AS4 and CM4) and a 64-row scanner (AS64 and CM64) using a cardiac phantom with calcium inserts. The results of the AS measurements (mean ± SD) varied significantly between the equipment: 880.6 ± 30.1 (AS4) vs 586.5 ± 24.0 (AS64; P < 0.0001). The AS interscanner variability was 31.6% for the phantom and from 25.5% to 110.1% for particular inserts. Mean ± SD CM values were different as well: 192.8 ± 5.0 mg (CM4) vs 152.4 ± 2.6 mg (CM64; P < 0.0001). Determination of CM with 64-row CT was more accurate than that with an older scanner; the mean relative error was -9.1% and 15.0%, respectively (P < 0.0001). The CM interscanner variability was 23.3% for the phantom and from 19.0% to 122.8% for particular inserts. The interexamination variability ranged from 1.7% (CM64) to 5.6% (AS4). Coronary artery calcium scoring with the 64-row CT scanner is more accurate than with the 4-row device The difference between the results of AS and CM measurements carried out with both scanners is statistically significant.

  11. 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.

  12. CT colonography: Diagnostic role of contrast enhancement of benign polyps and colorectal carcinoma

    International Nuclear Information System (INIS)

    Stoinova, V.; Nedevska, M.

    2006-01-01

    Full text: The aim of this study was to compare pre- and postcontrast CT attenuation values of benign colorectal polyps and carcinoma lesions detected by CT colonography, and to investigate whether contrast enhancement of these lesions can be potentially used for differentiation from residual fluid and feces. We retrospectively reviewed CT colonographic dataset of 120 patients. 35 benign polyps and 22 colorectal carcinomas were included in our study. All lesions were confirmed by colonoscopic biopsy or surgery. The difference in attenuation value between precontrast and postcontrast studies of polyps was statistically significant; the same was true for colorectal cancers. In the precontrast phase no statistically significant difference was observed between stool, polyps and cancers. The mean attenuation value of solid fecal residuals was 37 HU before and after contrast enhancement. Residual fluid do not take up contrast and the density does not change in the contrast-enhanced phase. The difference between postcontrast density of polyps and cancers with respect to density of stools and residual fluid was significant. The use of contrast medium could be helpful in CT colonography for discriminating polypoid benign lesions and colorectal cancer from fecal and fluid residuals

  13. Preliminary studies of enhanced contrast radiography in anatomy and embryology of insects with Elettra synchrotron light

    International Nuclear Information System (INIS)

    Hoennicke, M.G.; Foerster, L.A.; Navarro-Silva, M.A.; Menk, R.-H.; Rigon, L.; Cusatis, C.

    2005-01-01

    Enhanced contrast X-ray imaging is achieved by exploiting the real part of the refraction index, which is responsible for the phase shifts, in addition to the imaginary part, which is responsible for the absorption. Such techniques are called X-ray phase contrast imaging. An analyzer-based X-ray phase contrast imaging set-up with Diffraction Enhanced Imaging processing (DEI) were used for preliminary studies in anatomy and embryology of insects. Parasitized stinkbug and moth eggs used as control agents of pests in vegetables and adult stinkbugs and mosquitoes (Aedes aegypti) were used as samples. The experimental setup was mounted in the SYRMEP beamline at ELETTRA. Images were obtained using a high spatial resolution CCD detector (pixel size 14x14μm 2 ) coupled with magnifying optics. Analyzer-based X-ray phase contrast images (PCI) and edge detection images show contrast and details not observed with conventional synchrotron radiography and open the possibility for future study in the embryonic development of insects

  14. Real-time contrast-enhanced ultrasound in diagnosing of focal spleen lesions

    International Nuclear Information System (INIS)

    Yu Xiaoling; Yu Jie; Liang Ping; Liu Fangyi

    2012-01-01

    Objective: To investigate the features of focal spleen lesions (FSLs) on contrast-enhanced ultrasound (CEUS) imaging. Materials and methods: CEUS with a blot injection of SonoVue was performed in 48 patients with 75 FSLs (median diameter 2.6 cm) and their perfusion characteristics were analyzed by using contrast pulse sequences (CPS) technique. Results: Among 19 malignant lesions (10 metastases, 7 lymphoma, 1 hemangiosarcoma, 1 epithelioid hemangioendothelioma) and 56 benign lesion (23 hemangiomas, 14 cysts, 8 infarctions, 4 splenic ruptures, 3 tuberculosis, 2 abscess, 1 pseudoaneurysm, 1 lymphangioma), 25 benign lesions were demonstrated nonenhancement. For malignancy, 50.0% (5/10) metastases and 57.1% (4/7) lymphomas were showed hypoenhancement in the arterial phase, and 18 (94.7%) of malignant lesions were hypo-enhancement in the parenchymal phase. Among 31 benign lesions with enhancement, 27 (87.1%) were showed isoenhancement or hyperenhancement in the arterial phase and 22 (71.0%) lesions were isoenhancement or hyperenhancement in the parenchymal phase. The sensitivity, specificity and accuracy of diagnosis for FSLs were 91.1%, 95.0% and 92.0% for CEUS and 75.0%, 84.2% and 77.3% respectively, for the conventional baseline ultrasound (BUS). Conclusion: Real-time CEUS can provide valuable information for the diagnosis and differential diagnosis of FSLs.

  15. X-ray phase-contrast CT of a pancreatic ductal adenocarcinoma mouse model.

    Directory of Open Access Journals (Sweden)

    Arne Tapfer

    Full Text Available To explore the potential of grating-based x-ray phase-contrast computed tomography (CT for preclinical research, a genetically engineered mouse model of pancreatic ductal adenocarcinoma (PDAC was investigated. One ex-vivo mouse specimen was scanned with different grating-based phase-contrast CT imaging setups covering two different settings: i high-resolution synchrotron radiation (SR imaging and ii dose-reduced imaging using either synchrotron radiation or a conventional x-ray tube source. These experimental settings were chosen to assess the potential of phase-contrast imaging for two different types of application: i high-performance imaging for virtual microscopy applications and ii biomedical imaging with increased soft-tissue contrast for in-vivo applications. For validation and as a reference, histological slicing and magnetic resonance imaging (MRI were performed on the same mouse specimen. For each x-ray imaging setup, attenuation and phase-contrast images were compared visually with regard to contrast in general, and specifically concerning the recognizability of lesions and cancerous tissue. To quantitatively assess contrast, the contrast-to-noise ratios (CNR of selected regions of interest (ROI in the attenuation images and the phase images were analyzed and compared. It was found that both for virtual microscopy and for in-vivo applications, there is great potential for phase-contrast imaging: in the SR-based benchmarking data, fine details about tissue composition are accessible in the phase images and the visibility of solid tumor tissue under dose-reduced conditions is markedly superior in the phase images. The present study hence demonstrates improved diagnostic value with phase-contrast CT in a mouse model of a complex endogenous cancer, promoting the use and further development of grating-based phase-contrast CT for biomedical imaging applications.

  16. Registration of ‘Kardia’, a Two-Rowed Spring Food Barley

    Science.gov (United States)

    ‘Kardia’ (Reg. No. XXXX, XXXX), a two-rowed spring food barley (Hordeum vulgare L.) developed by the USDA-ARS, Aberdeen, ID, in cooperation with the University of Idaho Agricultural Experiment Station, was released in 2015. Kardia is derived from the cross of ‘03AH3054 / 98Ab12019’ and was advanced...

  17. Pancreatic neuroendocrine tumors containing areas of iso- or hypoattenuation in dynamic contrast-enhanced computed tomography: Spectrum of imaging findings and pathological grading.

    Science.gov (United States)

    Hyodo, Ryota; Suzuki, Kojiro; Ogawa, Hiroshi; Komada, Tomohiro; Naganawa, Shinji

    2015-11-01

    To evaluate dynamic contrast-enhanced computed tomography (CT) features of pancreatic neuroendocrine tumors (PNETs) containing areas of iso- or hypoattenuation and the relationship with pathological grading. Between June 2006 and March 2014, 61 PNETs in 58 consecutive patients (29 male, 29 female; median-age 55 years), which were surgically diagnosed, underwent preoperative dynamic contrast-enhanced CT. PNETs were classified based on contrast enhancement patterns in the pancreatic phase: iso/hypo-PNETs were defined as tumors containing areas of iso- or hypoattenuation except for cystic components, and hyper-PNETs were tumors showing hyperattenuation over the whole area. CT findings and contrast-enhancement patterns of the tumors were evaluated retrospectively by two radiologists and compared with the pathological grading. Iso/hypo-PNETs comprised 26 tumors, and hyper-PNETs comprised 35 tumors. Not only hyper-PNETs but also most iso/hypo-PNETs showed peak enhancement in the pancreatic phase and a washout from the portal venous phase to the delayed phase. Iso/hypo-PNETs showed larger tumor size than the hyper-PNETs (mean, 3.7 cm vs. 1.6 cm; PIso/hypo-PNETs also showed significantly higher pathological grading (WHO 2010 classification; iso/hypo, G1=14, G2=11, G3=1; hyper, G1=34, G2=1; Piso/hypo-areas showed a rapid enhancement pattern as well as hyper-PNETs, various radiological features and higher malignant potential. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  18. Representations in Calculus: Two Contrasting Cases.

    Science.gov (United States)

    Aspinwall, Leslie; Shaw, Kenneth L.

    2002-01-01

    Illustrates the contrasting thinking processes of two beginning calculus students' geometric and analytic schemes for the derivative function. Suggests that teachers can enhance students' understanding by continuing to demonstrate how different representations of the same mathematical concept provide additional information. (KHR)

  19. Detection of hepatocellular carcinoma by Gd-EOB-DTPA-enhanced liver MRI: Comparison with triple phase 64 detector row helical CT

    International Nuclear Information System (INIS)

    Akai, Hiroyuki; Kiryu, Shigeru; Matsuda, Izuru; Satou, Jirou; Takao, Hidemasa; Tajima, Taku; Watanabe, Yasushi; Imamura, Hiroshi; Kokudo, Norihiro; Akahane, Masaaki; Ohtomo, Kuni

    2011-01-01

    Purpose: To compare the diagnostic performance of Gd-EOB-DTPA-enhanced MRI with that of triple phase 64-MDCT in the detection of hepatocellular carcinoma (HCC). Patients and methods: Thirty-four patients with 52 surgically proven lesions underwent Gd-EOB-DTPA-enhanced MRI and triple phase 64-MDCT. Two observers independently evaluated MR and CT imaging on a lesion-by-lesion basis. Sensitivity, positive and negative predictive values and reproducibility were evaluated. The diagnostic accuracy of each modality was assessed with alternative-free response receiver operating characteristic (ROC) analysis. Results: Both observers showed higher sensitivity in detecting lesions with MRI compared to CT, however, only the difference between the two imaging techniques for observer 2 was significant (P = 0.034). For lesions 1 cm or smaller, MRI and CT showed equal sensitivity (both 62.5%) with one observer, and MRI proved superior to CT with the other observer (MRI 75% vs. CT 56.3%), but the latter difference was not significant (P = 0.083). The difference in positive and negative predictive value between the two imaging techniques for each observer was not significant (P > 0.05). The areas under the ROC curve for each observer were 0.843 and 0.861 for MRI vs. 0.800 and 0.833 for CT and the differences were not significant. Reproducibility was higher using MRI for both observers, but the result was not significant (MRI 32/33 vs. CT 29/33, P = 0.083). Conclusion: Gd-EOB-DTPA-enhanced MRI tended to show higher diagnostic accuracy, sensitivity and reproducibility compared to triple phase 64-MDCT in the detection of hepatocellular carcinoma, however statistical significance was not achieved.

  20. CT urography

    Energy Technology Data Exchange (ETDEWEB)

    Korobkin, M. [Dept. of Radiology, Univ. of Michigan, Ann Arbor, MI (United States)

    2005-11-15

    With the advent of multidetector row CT scanners, evaluation of the urothelium of the entire urinary tract with high-resolution thin sections during a single breath-hold has become a reality. Multidetector CT urography (MDCTU) is a single examination that allows evaluation of potential urinary tract calculi, renal parenchymal masses, and both benign and malignant urothelial lesions. Initial results with this new technique are encouraging. Current investigations of MDCTU focus on methods to improve opacification and distension of the upper urinary tract - the collecting systems, pelvis, and ureters. The role of abdominal compression, infusion of saline and/or furosemide, and optimal time delay of excretory phase imaging is being explored. Upper tract urothelial malignancies, including small lesions less the 5 mmin diameter, can be detected with high sensitivity. Methods to reduce radiation exposure are being explored, including split-bolus contrast injection techniques that combine nephrographic and excretory phases into a single phase. It is likely that in the near future, radiological evaluation of significant unexplained hematuria or of known or prior urothelial malignancy will consist of a single examination - MDCTU. (orig.)

  1. Contrast medium enhancement of soft tissues and brain in CT examinations of dogs

    International Nuclear Information System (INIS)

    Pavlicek, M.

    2000-11-01

    CT is an x-ray based method which shows less contrast for soft tissue as has been known from radiography. Therefore, it is necessary to use intravenously administered iodine contrast media to detect and localize tumors, fistulas or other pathologic lesions. Usually contrast medium is administered manually which yields random patterns of media distribution due to varying application pressure during varying administration time, therefore enhancement of parenchymous organs could not be used to the optimum extent. The use of an automatic injection pump guarantees the necessary constancy during the examination procedure to undoubtedly detect pathologic enhancement of organs in the CT-image as known from human medicine. The standards which are expected of the injection pump and the contrast media are: a good contrast enhancement, a good accumulation in the examined organs, an accumulation, which lasts long enough during the diagnostic phase, and a rapid excretion without side effects. Because of the short scan time of the modern CT-scanner, the best contrast enhancement can be administered by a short bolus injection, which can be applied by the automatic injection pump with a defined flow and a defined quantity of contrast media. This guarantees a good enhancement in the chosen region for the duration of the scan. The main aim of this study is to find a standardized flow and quantity of contrast media for defined regions and organs considering the speed of the scanner. In a subsequent step, the existing scan-protocols are then updated using the newly found information. This study showed, that CT examination of the head and brain in middle-sized dogs can be administered with a flow of 0.5 ml/s and a dose of 2 ml of contrast medium per kg weight. The contrast enhancement of the brain is caused by the enhancement of the vessels, the parenchym is free of contrast media - brain shows a low increase of density. Only if the blood-brain-barrier is destroyed, it is possible that

  2. Contrast medium enhancement of soft tissues and brain in CT examinations of dogs

    International Nuclear Information System (INIS)

    Pavlicek, M.

    2000-11-01

    CT is a x-ray based method which shows less contrast for soft tissue as has been known from radiography. Therefore, it is necessary to use intravenously administered iodine contrast media to detect and localize tumors, fistulas or other pathologic lesions. Usually contrast medium is administered manually which yields random patterns of media distribution due to varying application pressure during varying administration time, therefore enhancement of parenchymous organs could not be used to the optimum extent. The use of an automatic injection pump guarantees the necessary constancy during the examination procedure to undoubtedly detect pathologic enhancement of organs in the CT-image as known from human medicine. The standards which are expected of the injection pump and the contrast media are: a good contrast enhancement, a good accumulation in the examined organs, an accumulation, which lasts long enough during the diagnostic phase, and a rapid excretion without side effects. Because of the short scan time of the modern CT-scanner, the best contrast enhancement can be administered by a short bolus injection, which can be applied by the automatic injection pump with a defined flow and a defined quantity of contrast media. This guarantees a good enhancement in the chosen region for the duration of the scan. The main aim of this study is to find a standardized flow and quantity of contrast media for defined regions and organs considering the speed of the scanner. In a subsequent step, the existing scan-protocols are then updated using the newly found information. This study showed, that CT examination of the head and brain in middle-sized dogs can be administered with a flow of 0.5 ml/s and a dose of 2 ml of contrast medium per kg weight. The contrast enhancement of the brain is caused by the enhancement of the vessels, the parenchym is free of contrast media - brain shows a low increase of density. Only if the blood-brain-barrier is destroyed, it is possible that

  3. Contrast enhanced CT of spinal cord angioma

    International Nuclear Information System (INIS)

    Nakamura, Takahiko; Ebitani, Tsutomu; Honma, Takao; Sofue, Muroto; Nakamura, Shigeru

    1982-01-01

    Contrast enhanced CT on 6 patients with spinal cord angioma showed enhancement in 2 of them. The conditions to produce contrast enhancement were the window width of 100 - 200, and the window level of 0 - 50. In spinal cord angioma, contrast enhanced CT is presently only an adjunct to angiography and myelography. Nevertheless, contrast enhanced CT is useful in the screening test for spinal cord angioma, in the patients who are nonindicated to angiography, and in the postoperative follow-up. (Ueda, J.)

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

    Science.gov (United States)

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

    2017-06-01

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

  5. Biomechanical comparison of four double-row speed-bridging rotator cuff repair techniques with or without medial or lateral row enhancement.

    Science.gov (United States)

    Pauly, Stephan; Fiebig, David; Kieser, Bettina; Albrecht, Bjoern; Schill, Alexander; Scheibel, Markus

    2011-12-01

    Biomechanical comparison of four different Speed-Bridge configurations with or without medial or lateral row reinforcement. Reinforcement of the knotless Speed-Bridge double-row repair technique with additional medial mattress- or lateral single-stitches was hypothesized to improve biomechanical repair stability at time zero. Controlled laboratory study: In 36 porcine fresh-frozen shoulders, the infraspinatus tendons were dissected and shoulders were randomized to four groups: (1) Speed-Bridge technique with single tendon perforation per anchor (STP); (2) Speed-Bridge technique with double tendon perforation per anchor (DTP); (3) Speed-Bridge technique with medial mattress-stitch reinforcement (MMS); (4) Speed-Bridge technique with lateral single-stitch reinforcement (LSS). All repairs were cyclically loaded from 10-60 N up to 10-200 N (20 N stepwise increase) using a material testing device. Forces at 3 and 5 mm gap formation, mode of failure and maximum load to failure were recorded. The MMS-technique with double tendon perforation showed significantly higher ultimate tensile strength (338.9 ± 90.0 N) than DTP (228.3 ± 99.9 N), LSS (188.9 ± 62.5 N) and STP-technique (122.2 ± 33.8 N). Furthermore, the MMS-technique provided increased maximal force resistance until 3 and 5 mm gap formation (3 mm: 77.8 ± 18.6 N; 5 mm: 113.3 ± 36.1 N) compared with LSS, DTP and STP (P row defect by tendon sawing first, then laterally. No anchor pullout occurred. Double tendon perforation per anchor and additional medial mattress stitches significantly enhance biomechanical construct stability at time zero in this ex vivo model when compared with the all-knotless Speed-Bridge rotator cuff repair.

  6. Vascularization of liver tumors - preliminary results with Coded Harmonic Angio (CHA), phase inversion imaging, 3D power Doppler and contrast medium-enhanced B-flow with second generation contrast agent (Optison).

    Science.gov (United States)

    Jung, E M; Kubale, R; Jungius, K-P; Jung, W; Lenhart, M; Clevert, D-A

    2006-01-01

    To investigate the dynamic value of contrast medium-enhanced ultrasonography with Optison for appraisal of the vascularization of hepatic tumors using harmonic imaging, 3D-/power Doppler and B-flow. 60 patients with a mean age of 56 years (range 35-76 years) with 93 liver tumors, including histopathologically proven hepatocellular carcinoma (HCC) [15 cases with 20 lesions], liver metastases of colorectal tumors [17 cases with 33 lesions], metastases of breast cancer [10 cases with 21 lesions] and hemangiomas [10 cases with 19 lesions] were prospectively investigated by means of multislice CT as well as native and contrast medium-enhanced ultrasound using a multifrequency transducer (2.5-4 MHz, Logig 9, GE). B scan was performed with additional color and power Doppler, followed by a bolus injection of 0.5 ml Optison. Tumor vascularization was evaluated with coded harmonic angio (CHA), pulse inversion imaging with power Doppler, 3D power Doppler and in the late phase (>5 min) with B-flow. In 15 cases with HCC, i.a. DSA was performed in addition. The results were also correlated with MRT and histological findings. Compared to spiral-CT/MRT, only 72/93 (77%) of the lesions could be detected in the B scan, 75/93 (81%) with CHA and 93/93 (100%) in the pulse inversion mode. Tumor vascularization was detectable in 43/93 (46%) of lesions with native power Doppler, in 75/93 (81%) of lesions after administering contrast medium in the CHA mode, in 81/93 (87%) of lesions in the pulse inversion mode with power Doppler and in 77/93 (83%) of lesions with contrast-enhanced B-flow. Early arterial and capillary perfusion was best detected with CHA, particularly in 20/20 (100%) of the HCC lesions, allowing a 3D reconstruction. 3D power Doppler was especially useful in investigating the tumor margins. Up to 20 min after contrast medium injection, B-flow was capable of detecting increased metastatic tumor vascularization in 42/54 (78%) of cases and intratumoral perfusion in 17/20 (85

  7. 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.

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

    International Nuclear Information System (INIS)

    Erdem, C. Zuhal; Bayar, Ulku; Erdem, L. Oktay; Barut, Aykut; Gundogdu, Sadi; Kaya, Erdal

    2004-01-01

    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 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 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

  9. Cardiac carcinoid: tricuspid delayed hyperenhancement on cardiac 64-slice multidetector CT and magnetic resonance imaging.

    LENUS (Irish Health Repository)

    Martos, R

    2012-02-01

    INTRODUCTION: Carcinoid heart disease is a rare condition in adults. Its diagnosis can be easily missed in a patient presenting to a primary care setting. We revised the advantages of using coronary multidetector computed tomography (MDCT) and cardiac magnetic resonance imaging (MRI) in diagnosing this condition. MATERIALS AND METHODS: We studied a 65-year-old patient with carcinoid heart disease and right heart failure using transthoracic Doppler-echocardiogram, cardiac MDCT and MRI. Cardiac echocardiogram revealed marked thickening and retraction of the tricuspid leaflets with dilated right atrium and ventricle. Cardiac MDCT and MRI demonstrated fixation and retraction of the tricuspid leaflets with delayed contrast hyperenhancement of the tricuspid annulus. CONCLUSION: This case demonstrates fascinating imaging findings of cardiac carcinoid disease and highlights the increasing utility of contrast-enhanced MRI and cardiac MDCT in the diagnosis of this interesting condition.

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

    International Nuclear Information System (INIS)

    Farina, Davide; Bodin, Christiane; Gandolfi, Silvia; De Gasperi, Werner; Borghesi, Andrea; Maroldi, Roberto

    2009-01-01

    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.

  11. 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); 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.

  12. Characterization of a high-energy in-line phase contrast tomosynthesis prototype.

    Science.gov (United States)

    Wu, Di; Yan, Aimin; Li, Yuhua; Wong, Molly D; Zheng, Bin; Wu, Xizeng; Liu, Hong

    2015-05-01

    In this research, a high-energy in-line phase contrast tomosynthesis prototype was developed and characterized through quantitative investigations and phantom studies. The prototype system consists of an x-ray source, a motorized rotation stage, and a CMOS detector with a pixel pitch of 0.05 mm. The x-ray source was operated at 120 kVp for this study, and the objects were mounted on the rotation stage 76.2 cm (R1) from the source and 114.3 cm (R2) from the detector. The large air gap between the object and detector guarantees sufficient phase-shift effects. The quantitative evaluation of this prototype included modulation transfer function and noise power spectrum measurements conducted under both projection mode and tomosynthesis mode. Phantom studies were performed including three custom designed phantoms with complex structures: a five-layer bubble wrap phantom, a fishbone phantom, and a chicken breast phantom with embedded fibrils and mass structures extracted from an ACR phantom. In-plane images of the phantoms were acquired to investigate their image qualities through observation, intensity profile plots, edge enhancement evaluations, and/or contrast-to-noise ratio calculations. In addition, the robust phase-attenuation duality (PAD)-based phase retrieval method was applied to tomosynthesis for the first time in this research. It was utilized as a preprocessing method to fully exhibit phase contrast on the angular projection before reconstruction. The resolution and noise characteristics of this high-energy in-line phase contrast tomosynthesis prototype were successfully investigated and demonstrated. The phantom studies demonstrated that this imaging prototype can successfully remove the structure overlapping in phantom projections, obtain delineate interfaces, and achieve better contrast-to-noise ratio after applying phase retrieval to the angular projections. This research successfully demonstrated a high-energy in-line phase contrast tomosynthesis

  13. Comparison radiation dose of Z-axis automatic tube current modulation technique with fixed tube current multi-detector row CT scanning of lower extremity venography

    International Nuclear Information System (INIS)

    Yoo, Beong Gyu; Kweon, Dae Cheol; Lee, Jong Seok; Jang, Keun Jo; Jeon, Sang Hwan; Kim, Yong Soo

    2007-01-01

    Z-axis automatic tube current modulation technique automatically adjusts tube current based on size of body region scanned. The purpose of the current study was to compare noise, and radiation dose of Multi-Detector row CT (MDCT) of lower extremity performed with Z-axis modulation technique of automatic tube current modulation with manual selection fixed tube current. Fifty consecutive underwent MDCT venography of lower extremity with use of a MDCT scanner fixed tube current and Z-axis automatic tube current modulation technique (10, 11 and 12 HU noise index, 70∼450 mA). Scanning parameters included 120 kVp, 0.5 second gantry rotation time, 1.35:1 beam pitch, and 1 mm reconstructed section thickness. For each subject, images obtained with Z-axis modulation were compared with previous images obtained with fixed tube current (200, 250, 300 mA) and with other parameters identical. Images were compared for noise at five levels: iliac, femoral, popliteal, tibial, and peroneal vein of lower extremity. Tube current and gantry rotation time used for acquisitions at these levels were recorded. All CT examinations of study and control groups were diagnostically acceptable, though objective noise was significantly more with Z-axis automatic tube current modulation. Compared with fixed tube current, Z-axis modulation resulted in reduction of CTDIvol (range, -6.5%∼-35.6%) and DLP (range,-0.2%∼-20.2%). Compared with manually selected fixed tube current, Z-axis automatic tube current modulation resulted in reduced radiation dose at MDCT of lower extremity venography

  14. Quantitative assessment of bone defect healing by multidetector CT in a pig model

    International Nuclear Information System (INIS)

    Riegger, Carolin; Kroepil, Patric; Lanzman, Rotem S.; Miese, Falk R.; Antoch, Gerald; Scherer, Axel; Jungbluth, Pascal; Hakimi, Mohssen; Wild, Michael; Hakimi, Ahmad R.

    2012-01-01

    To evaluate multidetector CT volumetry in the assessment of bone defect healing in comparison to histopathological findings in an animal model. In 16 mini-pigs, a circumscribed tibial bone defect was created. Multidetector CT (MDCT) of the tibia was performed on a 64-row scanner 42 days after the operation. The extent of bone healing was estimated quantitatively by MDCT volumetry using a commercially available software programme (syngo Volume, Siemens, Germany).The volume of the entire defect (including all pixels from -100 to 3,000 HU), the nonconsolidated areas (-100 to 500 HU), and areas of osseous consolidation (500 to 3,000 HU) were assessed and the extent of consolidation was calculated. Histomorphometry served as the reference standard. The extent of osseous consolidation in MDCT volumetry ranged from 19 to 92% (mean 65.4 ± 18.5%). There was a significant correlation between histologically visible newly formed bone and the extent of osseous consolidation on MDCT volumetry (r = 0.82, P < 0.0001). A significant negative correlation was detected between osseous consolidation on MDCT and histological areas of persisting defect (r = -0.9, P < 0.0001). MDCT volumetry is a promising tool for noninvasive monitoring of bone healing, showing excellent correlation with histomorphometry. (orig.)

  15. Quantitative assessment of bone defect healing by multidetector CT in a pig model

    Energy Technology Data Exchange (ETDEWEB)

    Riegger, Carolin; Kroepil, Patric; Lanzman, Rotem S.; Miese, Falk R.; Antoch, Gerald; Scherer, Axel [University Duesseldorf, Medical Faculty, Department of Diagnostic and Interventional Radiology, Duesseldorf (Germany); Jungbluth, Pascal; Hakimi, Mohssen; Wild, Michael [University Duesseldorf, Medical Faculty, Department of Traumatology and Hand Surgery, Duesseldorf (Germany); Hakimi, Ahmad R. [Universtity Duesseldorf, Medical Faculty, Department of Oral Surgery, Duesseldorf (Germany)

    2012-05-15

    To evaluate multidetector CT volumetry in the assessment of bone defect healing in comparison to histopathological findings in an animal model. In 16 mini-pigs, a circumscribed tibial bone defect was created. Multidetector CT (MDCT) of the tibia was performed on a 64-row scanner 42 days after the operation. The extent of bone healing was estimated quantitatively by MDCT volumetry using a commercially available software programme (syngo Volume, Siemens, Germany).The volume of the entire defect (including all pixels from -100 to 3,000 HU), the nonconsolidated areas (-100 to 500 HU), and areas of osseous consolidation (500 to 3,000 HU) were assessed and the extent of consolidation was calculated. Histomorphometry served as the reference standard. The extent of osseous consolidation in MDCT volumetry ranged from 19 to 92% (mean 65.4 {+-} 18.5%). There was a significant correlation between histologically visible newly formed bone and the extent of osseous consolidation on MDCT volumetry (r = 0.82, P < 0.0001). A significant negative correlation was detected between osseous consolidation on MDCT and histological areas of persisting defect (r = -0.9, P < 0.0001). MDCT volumetry is a promising tool for noninvasive monitoring of bone healing, showing excellent correlation with histomorphometry. (orig.)

  16. Contrast-enhanced ultrasound features of hepatocellular carcinoma not detected during the screening procedure.

    Science.gov (United States)

    Dong, Yi; Wang, Wen-Ping; Mao, Feng; Dietrich, Christoph

    2017-08-01

    Aim  The aim of this retrospective study is to report on the characteristics of contrast-enhanced ultrasound (CEUS) of primarily not detected hepatocellular carcinoma (HCC) during the screening procedure of patients at risk. Methods  Sixty-four patients with a finally solitary and histologically proven HCC not detected HCC during the screening procedure were retrospectively analyzed. Most of HCC lesions (90.6 %, 58/64) measured < 20 mm in diameter. All HCC lesions were not detected during the initial screening procedure but suspected using contrast-enhanced magnetic resonance imaging. The final gold standard was biopsy or surgery with histological examination. Results  On CEUS, 62/64 (96.8 %) of HCC were characterized as an obviously hyperenhanced lesion in arterial phase, and 41/64 (64.1 %) of HCC were characterized as hypoenhancing lesions in the portal venous and late phases. During the arterial phase of CEUS, 96.8 % of HCC displayed homogeneous hyperenhancement. Knowing the CEUS and magnetic resonance imaging findings, 45/64 (70.3 %) could have been detected using B-mode ultrasound (BMUS). Conclusion  BMUS as a screening procedure is generally accepted. Contrast-enhanced imaging modalities have improved detection and characterization of HCC. Homogeneous hyperenhancement during the arterial phase and mild washout are indicative for HCC in liver cirrhosis. © Georg Thieme Verlag KG Stuttgart · New York.

  17. Fungal Distribution and Varieties Resistance to Kernel Discoloration in Korean Two-rowed Barley

    Directory of Open Access Journals (Sweden)

    Sang-Hyun Shin

    2013-09-01

    Full Text Available Barley kernel discoloration (KD leads to substantial loss in value through downgrading and discounting of malting barley. The objective of this research is to investigate fungal distribution and varieties resistance to KD in Korean two-rowed barley. Several fungal organisms including Alternaria spp., Fusarium spp., Aspergillus spp., Epicoccum spp. and Rhizopus spp. were isolated from Korean two-rowed barley representing KD. The symptoms of KD were brown and black discolorations of the lemma and palea. The most frequently detected fungal species was Alternaria spp. which exhibited 69.1% and 72.2% in 2011 and 2012, respectively. Epicoccum spp., Fusarium spp., and Aspergillus spp. were also detected. Fusarium spp., primary pathogen of barley head blight, were rarely occurred in the 2011 and their occurrence increased to 4.7% in 2012. Twenty cultivars of Korean two-rowed barely were evaluated to KD. The average percentage of KD was 8.0−36.0% in 2011 and 5.2−36.6% in 2012. Two cultivars (‘Sacheon 6’ and ‘Dajinbori’ showed KD of 6.2% to 8.8% and determined resistant, however ‘Samdobori’ and ‘Daeyeongbori’ demonstrating KD of 22.2−36.6% were highly susceptible. ‘Jinyangbori’, ‘Danwonbori’, ‘Sinhobori’ and ‘Kwangmaegbori’ showing KD of less than 15% were moderately resistant cultivar.

  18. Comparison of Oral Contrast-Enhanced Transabdominal Ultrasound Imaging With Transverse Contrast-Enhanced Computed Tomography in Preoperative Tumor Staging of Advanced Gastric Carcinoma.

    Science.gov (United States)

    He, Xuemei; Sun, Jing; Huang, Xiaoling; Zeng, Chun; Ge, Yinggang; Zhang, Jun; Wu, Jingxian

    2017-12-01

    This study assessed the diagnostic performance of transabdominal oral contrast-enhanced ultrasound (US) imaging for preoperative tumor staging of advanced gastric carcinoma by comparing it with transverse contrast-enhanced computed tomography (CT). This retrospective study included 42 patients with advanced gastric cancer who underwent laparoscopy, radical surgery, or palliative surgery because of serious complications and had a body mass index of less than 25 kg/m 2 . A cereal-based oral contrast agent was used for transabdominal oral contrast-enhanced US. Retrospective analyses were conducted using preoperative tumor staging data acquired by either transabdominal oral contrast-enhanced US or transverse contrast-enhanced CT. Both contrast-enhanced US and contrast-enhanced CT examinations were reviewed by 2 experienced radiologists independently for preoperative tumor staging according to the seventh edition of the TNM classification. The accuracy, sensitivity, and specificity were calculated by comparing the results of contrast-enhanced US and contrast-enhanced CT with pathologic findings. The overall accuracies of the imaging modalities were compared by the McNemar test. No significant difference was noted in the overall accuracy of transabdominal oral contrast-enhanced US (86% [36 of 42]) and transverse contrast-enhanced CT (83% [35 of 42] P > .999). For stage T2 to T4 gastric cancer, the accuracies of transabdominal oral contrast-enhanced US were 88%, 86%, and 98%, respectively, and those of transverse contrast-enhanced CT were 93%, 83%, and 90%. The overall accuracy of transabdominal oral contrast-enhanced US was comparable with that of transverse contrast-enhanced CT for preoperative tumor staging of advanced gastric cancer. © 2017 by the American Institute of Ultrasound in Medicine.

  19. Multidetector-row computed tomography in the preoperative diagnosis of intestinal complications caused by clinically unsuspected ingested dietary foreign bodies: a case series emphasizing the use of volume rendering techniques

    Energy Technology Data Exchange (ETDEWEB)

    Teixeira, Augusto Cesar Vieira; Torres, Ulysses dos Santos; Oliveira, Eduardo Portela de; Gual, Fabiana; Bauab Junior, Tufik, E-mail: usantor@yahoo.com.br [Faculdade de Medicina de Sao Jose do Rio Preto (FAMERP), SP (Brazil). Hospital de Base. Serv. de Radiologia e Diagnostico por Imagem; Westin, Carlos Eduardo Garcia [Faculdade de Medicina de Sao Jose do Rio Preto (FAMERP), SP (Brazil). Hospital de Base. Cirurgia Geral; Cardoso, Luciana Vargas [Faculdade de Medicina de Sao Jose do Rio Preto (FAMERP), SP (Brazil). Hospital de Base. Setor de Tomografia Computadorizada

    2013-11-15

    Objective: the present study was aimed at describing a case series where a preoperative diagnosis of intestinal complications secondary to accidentally ingested dietary foreign bodies was made by multidetector-row computed tomography (MDCT), with emphasis on complementary findings yielded by volume rendering techniques (VRT) and curved multiplanar reconstructions (MPR). Materials and Methods: The authors retrospectively assessed five patients with surgically confirmed intestinal complications (perforation and/or obstruction) secondary to unsuspected ingested dietary foreign bodies, consecutively assisted in their institution between 2010 and 2012. Demographic, clinical, laboratory and radiological data were analyzed. VRT and curved MPR were subsequently performed. Results: preoperative diagnosis of intestinal complications was originally performed in all cases. In one case the presence of a foreign body was not initially identified as the causal factor, and the use of complementary techniques facilitated its retrospective identification. In all cases these tools allowed a better depiction of the entire foreign bodies on a single image section, contributing to the assessment of their morphology. Conclusion: although the use of complementary techniques has not had a direct impact on diagnostic performance in most cases of this series, they may provide a better depiction of foreign bodies' morphology on a single image section. (author)

  20. Triphasic contrast enhanced CT simulation with bolus tracking for pancreas SBRT target delineation.

    Science.gov (United States)

    Godfrey, Devon J; Patel, Bhavik N; Adamson, Justus D; Subashi, Ergys; Salama, Joseph K; Palta, Manisha

    Bolus-tracked multiphasic contrast computed tomography (CT) is often used in diagnostic radiology to enhance the visibility of pancreas tumors, but is uncommon in radiation therapy pancreas CT simulation, and its impact on gross tumor volume (GTV) delineation is unknown. This study evaluates the lesion conspicuity and consistency of pancreas stereotactic body radiation therapy (SBRT) GTVs contoured in the different contrast phases of triphasic CT simulation scans. Triphasic, bolus-tracked planning CT simulation scans of 10 consecutive pancreas SBRT patients were acquired, yielding images of the pancreas during the late arterial (LA), portal venous (PV), and either the early arterial or delayed phase. GTVs were contoured on each phase by a gastrointestinal-specialized radiation oncologist and reviewed by a fellowship-trained abdominal radiologist who specializes in pancreatic imaging. The volumes of the registered GTVs, their overlap ratio, and the 3-dimensional margin expansions necessary for each GTV to fully encompass GTVs from the other phases were calculated. The contrast difference between tumor and normal pancreas was measured, and 2 radiation oncologists rank-ordered the phases according to their value for the lesion-contouring task. Tumor-to-pancreas enhancement was on average much larger for the LA and PV than the delayed phase or early arterial phases; the LA and PV phases were also consistently preferred by the radiation oncologists. Enhancement differences among the phases resulted in highly variable GTV volumes with no observed trends. Overlap ratios ranged from 18% to 75% across all 3 phases, improving to 43% to 91% when considering only the preferred LA and PV phases. GTV expansions necessary to encompass all GTVs ranged from 0.3 to 1.8 cm for all 3 phases, improving slightly to 0.1 to 1.4 cm when considering just the LA and PV phases. For pancreas SBRT, we recommend combining the GTVs from a multiphasic CT simulation with bolus-tracking, including