WorldWideScience

Sample records for 64-detector row ct

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

    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.

  2. Coronary CT angiography using 64 detector rows: methods and design of the multi-centre trial CORE-64

    Multislice computed tomography (MSCT) for the noninvasive detection of coronary artery stenoses is a promising candidate for widespread clinical application because of its non-invasive nature and high sensitivity and negative predictive value as found in several previous studies using 16 to 64 simultaneous detector rows. A multi-centre study of CT coronary angiography using 16 simultaneous detector rows has shown that 16-slice CT is limited by a high number of nondiagnostic cases and a high false-positive rate. A recent meta-analysis indicated a significant interaction between the size of the study sample and the diagnostic odds ratios suggestive of small study bias, highlighting the importance of evaluating MSCT using 64 simultaneous detector rows in a multi-centre approach with a larger sample size. In this manuscript we detail the objectives and methods of the prospective ''CORE-64'' trial (''Coronary Evaluation Using Multidetector Spiral Computed Tomography Angiography using 64 Detectors''). This multi-centre trial was unique in that it assessed the diagnostic performance of 64-slice CT coronary angiography in nine centres worldwide in comparison to conventional coronary angiography. In conclusion, the multi-centre, multi-institutional and multi-continental trial CORE-64 has great potential to ultimately assess the per-patient diagnostic performance of coronary CT angiography using 64 simultaneous detector rows. (orig.)

  3. Coronary CT angiography using 64 detector rows: methods and design of the multi-centre trial CORE-64

    Miller, Julie M.; Vavere, Andrea L.; Arbab-Zadeh, Armin; Bush, David E.; Lardo, Albert C.; Texter, John; Brinker, Jeffery; Lima, Joao A.C. [Johns Hopkins Hospital, Johns Hopkins University, Department of Medicine, Division of Cardiology, Baltimore, MD (United States); Dewey, Marc [Charite - Universitaetsmedizin Berlin, Medical School, Humboldt-Universitaet und Freie Universitaet zu Berlin, Department of Radiology, Berlin, PO Box 10098 (Germany); Rochitte, Carlos E.; Lemos, Pedro A. [University of Sao Paulo Medical School, Heart Institute (InCor), Sao Paulo (Brazil); Niinuma, Hiroyuki [Iwate Medical University, Department of Cardiology, Morioka (Japan); Paul, Narinder [Toronto General Hospital, Department of Medical Imaging, Toronto (Canada); Hoe, John [Medi-Rad Associates Ltd, CT Centre, Mt Elizabeth Hospital, Singapore (Singapore); Roos, Albert de [Leiden University Medical Center, Department of Radiology, Leiden (Netherlands); Yoshioka, Kunihiro [Iwate Medical University, Department of Radiology, Morioka (Japan); Cox, Christopher [Johns Hopkins Bloomberg School of Public Health, Department of Epidemiology, Baltimore, MD (United States); Clouse, Melvin E. [Harvard University, Department of Radiology, Beth Israel Deaconess, Boston, MA (United States)

    2009-04-15

    Multislice computed tomography (MSCT) for the noninvasive detection of coronary artery stenoses is a promising candidate for widespread clinical application because of its non-invasive nature and high sensitivity and negative predictive value as found in several previous studies using 16 to 64 simultaneous detector rows. A multi-centre study of CT coronary angiography using 16 simultaneous detector rows has shown that 16-slice CT is limited by a high number of nondiagnostic cases and a high false-positive rate. A recent meta-analysis indicated a significant interaction between the size of the study sample and the diagnostic odds ratios suggestive of small study bias, highlighting the importance of evaluating MSCT using 64 simultaneous detector rows in a multi-centre approach with a larger sample size. In this manuscript we detail the objectives and methods of the prospective ''CORE-64'' trial (''Coronary Evaluation Using Multidetector Spiral Computed Tomography Angiography using 64 Detectors''). This multi-centre trial was unique in that it assessed the diagnostic performance of 64-slice CT coronary angiography in nine centres worldwide in comparison to conventional coronary angiography. In conclusion, the multi-centre, multi-institutional and multi-continental trial CORE-64 has great potential to ultimately assess the per-patient diagnostic performance of coronary CT angiography using 64 simultaneous detector rows. (orig.)

  4. 3D automatic exposure control for 64-detector row CT: Radiation dose reduction in chest phantom study

    Purpose: The purpose of this study was to determine the utility of three-dimensional (3D) automatic exposure control (AEC) for low-dose CT examination in a chest phantom study. Materials and methods: A chest CT phantom including simulated focal ground-glass opacities (GGOs) and nodules was scanned with a 64-detector row CT with and without AEC. Performance of 3D AEC included changing targeted standard deviations (SDs) of image noise from scout view. To determine the appropriate targeted SD number for identification, the capability of overall identification with the CT protocol adapted to each of the targeted SDs was compared with that obtained with CT without AEC by means of receiver operating characteristic analysis. Results: When targeted SD values equal to or higher than 250 were used, areas under the curve (Azs) of nodule identification with CT protocol using AEC were significantly smaller than that for CT protocol without AEC (p < 0.05). When targeted SD numbers at equal to or more than 180 were adapted, Azs of CT protocol with AEC had significantly smaller than that without AEC (p < 0.05). Conclusion: This phantom study shows 3D AEC is useful for low-dose lung CT examination, and can reduce the radiation dose while maintaining good identification capability and good image quality.

  5. 3D automatic exposure control for 64-detector row CT: Radiation dose reduction in chest phantom study

    Matsumoto, Keiko, E-mail: palm_kei@yahoo.co.jp [Department of Radiology, Kobe University Graduate School of Medicine, Kobe, Hyogo (Japan); Department of Radiology, Yamanashi University, Shimokato, Yamanashi (Japan); Ohno, Yoshiharu; Koyama, Hisanobu; Kono, Atsushi [Department of Radiology, Kobe University Graduate School of Medicine, Kobe, Hyogo (Japan); Inokawa, Hiroyasu [Toshiba Medical Systems, Ohtawara, Tochigi (Japan); Onishi, Yumiko [Department of Radiology, Kobe University Graduate School of Medicine, Kobe, Hyogo (Japan); Nogami, Munenobu [Department of Radiology, Kobe University Graduate School of Medicine, Kobe, Hyogo (Japan); Division of Image-Based Medicine, Institute of Biomedical Research and Innovation, Kobe, Hyogo (Japan); Takenaka, Daisuke [Department of Radiology, Kobe University Graduate School of Medicine, Kobe, Hyogo (Japan); Araki, Tsutomu [Department of Radiology, Yamanashi University, Shimokato, Yamanashi (Japan); Sugimura, Kazuro [Department of Radiology, Kobe University Graduate School of Medicine, Kobe, Hyogo (Japan)

    2011-03-15

    Purpose: The purpose of this study was to determine the utility of three-dimensional (3D) automatic exposure control (AEC) for low-dose CT examination in a chest phantom study. Materials and methods: A chest CT phantom including simulated focal ground-glass opacities (GGOs) and nodules was scanned with a 64-detector row CT with and without AEC. Performance of 3D AEC included changing targeted standard deviations (SDs) of image noise from scout view. To determine the appropriate targeted SD number for identification, the capability of overall identification with the CT protocol adapted to each of the targeted SDs was compared with that obtained with CT without AEC by means of receiver operating characteristic analysis. Results: When targeted SD values equal to or higher than 250 were used, areas under the curve (Azs) of nodule identification with CT protocol using AEC were significantly smaller than that for CT protocol without AEC (p < 0.05). When targeted SD numbers at equal to or more than 180 were adapted, Azs of CT protocol with AEC had significantly smaller than that without AEC (p < 0.05). Conclusion: This phantom study shows 3D AEC is useful for low-dose lung CT examination, and can reduce the radiation dose while maintaining good identification capability and good image quality.

  6. Chronic thromboembolic pulmonary hypertension: Evaluation with 64-detector row CT versus digital substraction angiography

    The aim of the study was to evaluate the role of 64-row CT in the diagnostic workup of patients with chronic thromboembolic pulmonary hypertension (CTEPH) using digital substraction angiography (DSA) as the method of diagnostic reference. CT and DSA studies of 27 patients (54 main, 162 lobar and 540 segmental arteries) with a clinical suspicion of CTEPH were included in this retrospective and blinded analysis. Axial images and multiplanar thin maximum intensity projections (MIPs) (3 mm) were consequently used for exact image interpretation whereas additional reconstructed thick MIPs gave an overview of the entire vascular tree comparable to DSA. Sensitivity and specificity of CT regarding CTEPH-related pathological changes in general were 98.3% and 94.8% at main/lobar level and 94.1% and 92.9% at segmental level, respectively. Sensitivity and specificity of CT regarding the different pathological criteria of CTEPH (complete obstruction, intimal irregularities, bands and webs, indirect signs) were 88.9-100% and 96.1-100% at main/lobar level and 84.3-90.5% and 92-98.7% at segmental level, respectively. Our results show that CT is an accurate and reliable non-invasive alternative to conventional DSA in the diagnostic workup in patients with CTEPH.

  7. Thin-section CT of lung without ECG gating: 64-detector row CT can markedly reduce cardiac motion artifact which can simulate lung lesions

    Purpose: Motion artifacts, which can mimic thickened bronchial wall and the cystic appearance of bronchiectasis, constitute a potential pitfall in the diagnosis of interstitial or bronchial disease. Therefore, purpose of our study was to evaluate whether 64-detector row CT (64-MDCT) enables a reduction in respiratory or cardiac motion artifacts in the lung area on thin-section CT without ECG gating, and to examine the correlation between cardiac motion artifact and heart rate. Materials and methods: Thirty-two patients with suspected diffuse lung disease, who underwent both 8- and 64-MDCT (gantry rotation time, 0.5 and 0.4 s, respectively), were included. The heart rates of an additional 155 patients were measured (range, 48-126 beats per minute; mean, 76 beats per minute) immediately prior to 64-MDCT, and compared to the degree of cardiac motion artifact. Two independent observers evaluated the following artifacts on a monitor without the knowledge of relevant clinical information: (1) artifacts on 8- and 64-MDCT images with 1.25-mm thickness and those on 64-MDCT images with 0.625-mm thickness in 32 patients; and (2) artifacts on 64-MDCT images with 0.625-mm thickness in 155 patients. Results: Interobserver agreement was good in evaluating artifacts on 8-MDCT images with 1.25-mm thickness (weighted Kappa test, κ = 0.61-0.71), and fair or poor in the other evaluations (κ < 0.31). Two observers stated that cardiac motion artifacts were more significant on 8-MDCT than on 64-MDCT in all 32 patients. Statistically significant differences were found at various checkpoints only in comparing artifacts between 8- and 64-MDCT for 1.25-mm thickness (Wilcoxon's signed-rank test, p < 0.0017). Cardiac motion artifacts on 64-MDCT had no significant correlation with heart rate (Spearman's correlation coefficient by rank test). Conclusion: The high temporal resolution of 64-MDCT appears to reduce cardiac motion artifact that can affect thin-section scans of the lung parenchyma

  8. Does Gadoxetic acid-enhanced 3.0T MRI in addition to 64-detector-row contrast-enhanced CT provide better diagnostic performance and change the therapeutic strategy for the preoperative evaluation of colorectal liver metastases?

    Sofue, Keitaro [National Cancer Center Hospital, Division of Diagnostic Radiology, Tokyo (Japan); Kobe University, Department of Radiology, Graduate School of Medicine, Kobe (Japan); Tsurusaki, Masakatsu [National Cancer Center Hospital, Division of Diagnostic Radiology, Tokyo (Japan); Kinki University, Department of Radiology, Faculty of Medicine, Osakasayama, Osaka (Japan); Murakami, Takamichi [Kinki University, Department of Radiology, Faculty of Medicine, Osakasayama, Osaka (Japan); Onoe, Shunsuke [National Cancer Center Hospital, Department of Hepatobiliary and Pancreatic Surgery, Tokyo (Japan); Tokue, Hiroyuki; Shibamoto, Kentaro; Arai, Yasuaki [National Cancer Center Hospital, Division of Diagnostic Radiology, Tokyo (Japan); Sugimura, Kazuro [Kobe University, Department of Radiology, Graduate School of Medicine, Kobe (Japan)

    2014-10-15

    To compare diagnostic performance in the detection of colorectal liver metastases between 64-detector-row contrast-enhanced CT (CE-CT) alone and the combination of CE-CT and gadoxetic acid-enhanced MRI (EOB-MRI) at 3.0T, and to assess whether EOB-MRI in addition to CE-CT results in a change to initially planned operative strategy. A total of 39 patients (27 men, mean age 65 years) with 85 histopathologically confirmed liver metastases were included. At EOB-MRI, unenhanced (T1- and T2-weighted), dynamic, and hepatocyte-phase images were obtained. At CE-CT, four-phase dynamic contrast-enhanced images were obtained. One on-site reader and three off-site readers independently reviewed both CE-CT alone and the combination of CE-CT and EOB-MRI. Sensitivity, positive predictive value, and alternative free-response receiver operating characteristic (AFROC) method were calculated. Differences in therapeutic strategy before and after the EOB-MRI examination were also evaluated. Sensitivity and area under the AFROC curve with the combination of CE-CT and EOB-MRI were significantly superior to those with CE-CT alone. Changes in surgical therapy were documented in 13 of 39 patients. The combination of CE-CT and EOB-MRI may provide better diagnostic performance than CE-CT alone for the detection of colorectal liver metastases, and EOB-MRI in addition to CE-CT resulted in changes to the planned operative strategy in one-third of the patients. (orig.)

  9. Does Gadoxetic acid-enhanced 3.0T MRI in addition to 64-detector-row contrast-enhanced CT provide better diagnostic performance and change the therapeutic strategy for the preoperative evaluation of colorectal liver metastases?

    To compare diagnostic performance in the detection of colorectal liver metastases between 64-detector-row contrast-enhanced CT (CE-CT) alone and the combination of CE-CT and gadoxetic acid-enhanced MRI (EOB-MRI) at 3.0T, and to assess whether EOB-MRI in addition to CE-CT results in a change to initially planned operative strategy. A total of 39 patients (27 men, mean age 65 years) with 85 histopathologically confirmed liver metastases were included. At EOB-MRI, unenhanced (T1- and T2-weighted), dynamic, and hepatocyte-phase images were obtained. At CE-CT, four-phase dynamic contrast-enhanced images were obtained. One on-site reader and three off-site readers independently reviewed both CE-CT alone and the combination of CE-CT and EOB-MRI. Sensitivity, positive predictive value, and alternative free-response receiver operating characteristic (AFROC) method were calculated. Differences in therapeutic strategy before and after the EOB-MRI examination were also evaluated. Sensitivity and area under the AFROC curve with the combination of CE-CT and EOB-MRI were significantly superior to those with CE-CT alone. Changes in surgical therapy were documented in 13 of 39 patients. The combination of CE-CT and EOB-MRI may provide better diagnostic performance than CE-CT alone for the detection of colorectal liver metastases, and EOB-MRI in addition to CE-CT resulted in changes to the planned operative strategy in one-third of the patients. (orig.)

  10. Prevalence of Congenital Coronary Artery Anomalies and Variants in 2697 Consecutive Patients Using 64-Detector Row Coronary CTAngiography

    Farzaneh Fattahi Masrour; Reza Tayebivaljozi,; Shahram Akhlaghpoor; Abbas Arjmand Shabestari

    2012-01-01

    Background: Coronary artery anomalies are not common, but could be very serious.Objectives: This study determines the frequency of coronary anomalies and normal variants by multi-detector-row computed tomography (MDCT).Patients and Methods: The results of cardiac MDCT study in 2697 consecutive patients were analyzed retrospectively. Acquisition was performed by a 64-detector row CT machine. Imaging results were assessed by experienced radiologists.Results: Myocardial bridging was by far the m...

  11. Prevalence of Congenital Coronary Artery Anomalies and Variants in 2697 Consecutive Patients Using 64-Detector Row Coronary CTAngiography

    Shabestari, Abbas Arjmand; Akhlaghpoor, Shahram; Tayebivaljozi, Reza; Fattahi Masrour, Farzaneh

    2012-01-01

    Background Coronary artery anomalies are not common, but could be very serious. Objectives This study determines the frequency of coronary anomalies and normal variants by multi-detector-row computed tomography (MDCT). Patients and Methods The results of cardiac MDCT study in 2697 consecutive patients were analyzed retrospectively. Acquisition was performed by a 64-detector row CT machine. Imaging results were assessed by experienced radiologists. Results Myocardial bridging was by far the mo...

  12. Prevalence of Congenital Coronary Artery Anomalies and Variants in 2697 Consecutive Patients Using 64-Detector Row Coronary CTAngiography

    Coronary artery anomalies are not common, but could be very serious. This study determines the frequency of coronary anomalies and normal variants by multi-detector-row computed tomography (MDCT). The results of cardiac MDCT study in 2697 consecutive patients were analyzed retrospectively. Acquisition was performed by a 64-detector row CT machine. Imaging results were assessed by experienced radiologists. Myocardial bridging was by far the most frequent coronary variant (n = 576, 21.3%). Eighty-three subjects (3.1%) showed other coronary anomalies and variants. Anomalies of origination and course of the left main coronary artery (LMCA) were detected in 1.09% of the subjects. The frequency of these anomalies in the right coronary artery (RCA), left circumflex artery (LCx), left anterior descending artery (LAD), posterior descending artery (PDA) and obtuse marginal (OM) artery were 1.24%, 0.33%, 0.1%, 0.07% and 0.03%, respectively. The single coronary pattern was seen in 0.18% and coronary fistulas in 0.07%. Based on the fact that coronary CT-angiography using MDCT can display different coronary anomalies, this study shows similar results to other reports on the subject. Future advances in the performance of CT machines will further improve the quality of CT-based cardiac imaging

  13. Prevalence of Congenital Coronary Artery Anomalies and Variants in 2697 Consecutive Patients Using 64-Detector Row Coronary CTAngiography

    Farzaneh Fattahi Masrour

    2012-01-01

    Full Text Available Background: Coronary artery anomalies are not common, but could be very serious.Objectives: This study determines the frequency of coronary anomalies and normal variants by multi-detector-row computed tomography (MDCT.Patients and Methods: The results of cardiac MDCT study in 2697 consecutive patients were analyzed retrospectively. Acquisition was performed by a 64-detector row CT machine. Imaging results were assessed by experienced radiologists.Results: Myocardial bridging was by far the most frequent coronary variant (n = 576, 21.3%. Eighty-three subjects (3.1% showed other coronary anomalies and variants. Anomalies of origination and course of the left main coronary artery (LMCA were detected in 1.09% of the subjects. The frequency of these anomalies in the right coronary artery (RCA, left circumflex artery (LCx, left anterior descending artery (LAD, posterior descending artery (PDA and obtuse marginal (OM artery were 1.24%, 0.33%, 0.1%, 0.07% and 0.03%, respectively. The single coronary pattern was seen in 0.18% and coronary fistulas in 0.07%.Conclusion: Based on the fact that coronary CT-angiography using MDCT can display different coronary anomalies, this study shows similar results to other reports on the subject. Future advances in the performance of CT machines will further improve the quality of CT-based cardiac imaging.Keywords: Coronary Artery Disease,Tomography,X-Ray Computed,Patients

  14. Noninvasive Coronary Angiography using 64-Detector-Row Computed Tomography in Patients with a Low to Moderate Pretest Probability of Significant Coronary Artery Disease

    Schlosser, T.; Mohrs, O.K.; Magedanz, A.; Nowak, B.; Voigtlaender, T.; Barkhausen, J.; Schmermund, A. [Dept. of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen, Essen (Germany)

    2007-04-15

    Purpose: To evaluate the value of 64-detector-row computed tomography for ruling out high-grade coronary stenoses in patients with a low to moderate pretest probability of significant coronary artery disease. Material and Methods: The study included 61 patients with a suspicion of coronary artery disease on the basis of atypical angina or ambiguous findings in noninvasive stress testing and a class II indication for invasive coronary angiography (ICA). All patients were examined by 64-detector-row computed tomography angiography (CTA) and ICA. On a coronary segmental level, the presence of significant (>50% diameter) stenoses was examined. Results: In a total of 915 segments, CTA detected 62 significant stenoses. Thirty-four significant stenoses were confirmed by ICA, whereas 28 stenoses could not be confirmed by ICA. Twenty-two of them showed wall irregularities on ICA, and six were angiographically normal. Accordingly, on a coronary segmental basis, 28 false-positive and 0 false-negative findings resulted in a sensitivity of 100%, a specificity of 96.8%, a positive predictive value of 54.8%, and a negative predictive value of 100%. The diagnostic accuracy was 96.9%. Conclusion: Sixty-four-detector-row computed tomography reliably detects significant coronary stenoses in patients with suspected coronary artery disease and appears to be helpful in the selection of patients who need to undergo ICA. Calcified and non-calcified plaques are detected. Grading of stenoses in areas with calcification is difficult. Frequently, stenosis severity is overestimated by 64-detector-row computed tomography.

  15. In-Vitro Evaluation of Coronary Stents and 64-Detector-Row Computed Tomography Using a Newly Developed Model of Coronary Artery Stenosis

    Background: Stent implantation is the predominant therapy for non-surgical myocardial revascularization in patients with coronary artery disease. However, despite substantial advances in multidetector computed tomography (MDCT) coronary imaging, a reliable detection of coronary in-stent restenosis is currently not possible. Purpose: To examine the ability of 64-detector-row CT to detect and to grade in-stent stenosis in coronary stents using a newly developed ex-vivo vessel phantom with a realistic CT density pattern, artificial stenosis, and a thorax phantom. Material and Methods: Four different stents (Liberte and Lunar ROX, Boston Scientific; Driver, Medtronic; Multi-Link Vision, Guidant) were examined. The stents were placed on a polymer tube with a diameter of 2.5, 3.0, 3.5, or 4.0 mm. Different degrees of stenosis (0%, 30%, 50%, 70-80%) were created inside the tube. For quantitative analysis, attenuation values were measured in the non-stenotic vessel outside the stent, in the non-stenotic vessel inside the stent, and in the stenotic area inside the stent. The grade of stenosis was visually assessed by two observers. Results: All stents led to artificial reduction of attenuation, the least degree of which was found in the Liberte stent (11.3±10.2 HU) and the Multi-Link Vision stent (17.6±17.9 HU; P 0.25). Overall, the non-stenotic vessel was correctly diagnosed in 55.5%, the low-grade stenosis in 58.3%, the intermediate stenosis in 63.8%, and the high-grade stenosis in 80.5%. In the 3.0-, 3.5-, and 4.0-mm vessels, in none of the cases was a non-stenotic or low-grade stenotic vessel misdiagnosed as intermediate or high-grade stenosis. The average deviation from the real grade of stenosis was 0.40 for the Liberte stent, 0.46 for the Lunar ROX stent, 0.45 for the Driver stent, and 0.58 for the Multi-Link Vision stent. Conclusion: Our ex-vivo data show that non-stenotic stents and low-grade in-stent stenosis can be reliably differentiated from intermediate and

  16. 64-detector row CT coronary angiography:clinical application of retrospective electrocardiographic gating technique combined with electrocardiographic editing%心电编辑技术在64层螺旋CT冠状动脉成像中的临床应用分析

    虞凌明; 叶晓丹; 朱莉; 陈群慧

    2015-01-01

    目的:探讨心电编辑技术在64层螺旋C T冠状动脉成像检查中心电信号异常患者中的应用价值。方法病例选取我院行64层螺旋C T经静脉冠状动脉造影,且心率不齐,常规重组伪影严重,影响影像诊断的患者共36例。对常规CT重组影像和心电编辑后重组影像质量进行比较,根据节段显示情况及是否存在伪影将图像质量分为I~Ⅳ级,I~Ⅲ级符合影像学评价要求,I~Ⅱ级为优良阶段。比较64层螺旋C T回顾性心电门控结合心电编辑技术对心电获得异常患者的冠状动脉影像质量的影响。结果36例患者心电编辑前后可显示冠脉总数分别为521段和528段,心电编辑前图像质量Ⅰ、Ⅱ、Ⅲ、Ⅳ级节段分别为133段(25.5%)、162段(31.1%)、120段(23.0%)、106段(20.3%),图像质量符合诊断要求的共415段(79.6%)。心电编辑后图像质量Ⅰ、Ⅱ、Ⅲ、Ⅳ级节段分别为439段(83.1%)、70段(13.3%)、8段(1.5%)、11段(2.1%),冠状动脉显影优良节段为509段(96.4%),符合诊断要求节段共517段(97.9%),冠状动脉各段在心电编辑前后的影像质量差异均有统计学意义( P <0.05)。结论心电信号编辑能明显改善部分期前收缩和心电信号中出现触发点异常患者的冠状动脉MSCTA图像质量,具有一定的临床实用价值。%Objective To prospectively evaluate to what extent image quality in 64‐detector row computed tomographic (CT ) coronary angiography is a function of electrocardiographic editing and the image reconstruction technique used . Methods A total of 36 patients (14 men ,22 women ;mean age ,61 .0 years ± 9 .1) in department of radiology consecutive‐ly underwent multi‐detector row CT coronary angiography .Their electrocardiographic trigger points were proved to be in‐accurately or absent ,which caused unequal R

  17. Evaluation of Enteroneovesical Fistula by 64-Detector CT Enterography: A Case Report

    Algin, Oktay; Metin, Melike Rusen; Karaoglanoglu, Mustafa

    2015-01-01

    Enterovesical fistula is an abnormal communication between the bladder and the intestine. The accurate localization of leakage is important for accurate treatment planning. Some imaging techniques can not demonstrate the fistula; therefore, choosing the appropriate imaging technique is necessary. CT enterography (CTE) is a new technique for evaluation of the small bowel and the entire abdomen. CTE examination with multi-detector CT (MDCT) enables us to get excellent quality reformatted images...

  18. Desmoid Tumor Associated With Familial Adenomatous Polyposis: Evaluation With 64-Detector CT Enterography

    Oktay Algin; Sehnaz Evrimler; Evrim Ozmen; Melike Metin; Osman Ersoy; Mustafa Karaoglanoglu

    2012-01-01

    Desmoid tumors (DTs) are benign tumors which are not seen very often, and most of the radiologists and clinicians do not know the characteristics of them very well. Correct and early diagnosis of DTs is important for decreasing mortality and morbidity. Computed tomography enterography (CTE) is a new modality for small bowel imaging which combines the improved spatial and temporal resolution of multidetector computed tomography (CT) with large volumes of ingested enteric contrast material to p...

  19. Comparison of radiation dose estimates, image noise, and scan duration in pediatric body imaging for volumetric and helical modes on 320-detector CT and helical mode on 64-detector CT

    Advanced multidetector CT systems facilitate volumetric image acquisition, which offers theoretic dose savings over helical acquisition with shorter scan times. Compare effective dose (ED), scan duration and image noise using 320- and 64-detector CT scanners in various acquisition modes for clinical chest, abdomen and pelvis protocols. ED and scan durations were determined for 64-detector helical, 160-detector helical and volume modes under chest, abdomen and pelvis protocols on 320-detector CT with adaptive collimation and 64-detector helical mode on 64-detector CT without adaptive collimation in a phantom representing a 5-year-old child. Noise was measured as standard deviation of Hounsfield units. Compared to 64-detector helical CT, all acquisition modes on 320-detector CT resulted in lower ED and scan durations. Dose savings were greater for chest (27-46%) than abdomen/pelvis (18-28%) and chest/abdomen/pelvis imaging (8-14%). Noise was similar across scanning modes, although some protocols on 320-detector CT produced slightly higher noise. Dose savings can be achieved for chest, abdomen/pelvis and chest/abdomen/pelvis examinations on 320-detector CT compared to helical acquisition on 64-detector CT, with shorter scan durations. Although noise differences between some modes reached statistical significance, this is of doubtful diagnostic significance and will be studied further in a clinical setting. (orig.)

  20. Initial study of 3D perfused blood volume imaging using 64-detector CT in hyperacute cerebral infarction

    Objective: To evaluate the value of three dimensional CT whole brain perfused blood volume (3D-PBV) based on CTA row data in hyperacute cerebral infarction. Methods: 38 patients with stroke within 12 hours performed plain CT and CTA scans. 3D software Neuro PBV was applied to process the CTA row data and 3D-PBV of brain was obtained. MR examinations were performed within 2 hours after CT scans. The numbers of ischemic lesions on plain CT, 3D-PBV and MRI-DWI were recorded. The volumes of ischemic lesions on 3D-PBV and MR -DWI were measured. Results: In 38 patients, the number of infarct lesion detected by MRI-DWI, PBV, and plain CT was 45, 41, and 16 respectively. Kappa test showed a substantial agreement (κ=0.78) between 3D-PBV and MRI-DWI in detecting ischemic lesions. The detectability of plain CT showed fair or slight agreements to 3D-PBV and MR-DWI (κ=0.24, 0.18, respectively). The lesion volumes did not differ on 3D-PBV and MR-DWI (t=7.249, P>0.05). Conclusion: 3D-PBV combined with CTA can detect ischemic lesion and evaluate perfusion. It had important value in diagnosing hyperacute cerebral infarction. (authors)

  1. Desmoid Tumor Associated With Familial Adenomatous Polyposis: Evaluation With 64-Detector CT Enterography

    Desmoid tumors (DTs) are benign tumors which are not seen very often, and most of the radiologists and clinicians do not know the characteristics of them very well. Correct and early diagnosis of DTs is important for decreasing mortality and morbidity. Computed tomography enterography (CTE) is a new modality for small bowel imaging which combines the improved spatial and temporal resolution of multidetector computed tomography (CT) with large volumes of ingested enteric contrast material to permit evaluation of the small bowel wall and lumen and also the entire abdomen. We report a familial adenomatous polyposis (FAP) patient with localized mesentery and abdominal wall DTs. We showed the exact location of the DTs and their relation with the small bowel by CTE. In conclusion, CTE is a useful technique for DT localization, the degree of extension and invasion to local structures, presence of partial and complete small bowel obstruction, and the relationship of the tumors with vasculature and whether ischemia has occurred as a result or not

  2. Desmoid Tumor Associated With Familial Adenomatous Polyposis: Evaluation With 64-Detector CT Enterography

    Oktay Algin

    2012-03-01

    Full Text Available Desmoid tumors (DTs are benign tumors which are not seen very often, and most of the radiologists and clinicians do not know the characteristics of them very well. Correct and early diagnosis of DTs is important for decreasing mortality and morbidity. Computed tomography enterography (CTE is a new modality for small bowel imaging which combines the improved spatial and temporal resolution of multidetector computed tomography (CT with large volumes of ingested enteric contrast material to permit evaluation of the small bowel wall and lumen and also the entire abdomen. We report a familial adenomatous polyposis (FAP patient with localized mesentery and abdominal wall DTs. We showed the exact location of the DTs and their relation with the small bowel by CTE. In conclusion, CTE is a useful technique for DT localization, the degree of extension and invasion to local structures, presence of partial and complete small bowel obstruction, and the relationship of the tumors with vasculature and whether ischemia ha s occurred as a result or not.

  3. How many CT detector rows are necessary to perform adequate three dimensional visualization?

    Fischer, Lars, E-mail: lars.fischer@med.uni-heidelberg.d [Department of Surgery, University of Heidelberg (Germany); Tetzlaff, Ralf; Schoebinger, Max [DKFZ Heidelberg (Germany); Radeleff, Boris [Department of Interventional and Diagnostic Radiology, University of Heidelberg (Germany); Bruckner, Thomas [Institute for Medical Biometry and Informatics, Heidelberg (Germany); Meinzer, H.P. [DKFZ Heidelberg (Germany); Buechler, M.W.; Schemmer, Peter [Department of Surgery, University of Heidelberg (Germany)

    2010-06-15

    Introduction: The technical development of computer tomography (CT) imaging has experienced great progress. As consequence, CT data to be used for 3D visualization is not only based on 4 row CTs and 16 row CTs but also on 64 row CTs, respectively. The main goal of this study was to examine whether the increased amount of CT detector rows is correlated with improved quality of the 3D images. Material and Methods: All CTs were acquired during routinely performed preoperative evaluation. Overall, there were 12 data sets based on 4 detector row CT, 12 data sets based on 16 detector row CT, and 10 data sets based on 64 detector row CT. Imaging data sets were transferred to the DKFZ Heidelberg using the CHILI teleradiology system. For the analysis all CT scans were examined in a blinded fashion, i.e. both the name of the patient as well as the name of the CT brand were erased. For analysis, the time for segmentation of liver, both portal and hepatic veins as well as the branching depth of portal veins and hepatic veins was recorded automatically. In addition, all results were validated in a blinded fashion based on given quality index. Results: Segmentation of the liver was performed in significantly shorter time (p < 0.01, Kruskal-Wallis test) in the 16 row CT (median 479 s) compared to 4 row CT (median 611 s), and 64 row CT (median 670 s), respectively. The branching depth of the portal vein did not differ significantly among the 3 different data sets (p = 0.37, Kruskal-Wallis test). However, the branching depth of the hepatic veins was significantly better (p = 0.028, Kruskal-Wallis test) in the 4 row CT and 16 row CT compared to 64 row CT. The grading of the quality index was not statistically different for portal veins and hepatic veins (p = 0.80, Kruskal-Wallis test). Even though the total quality index was better for the vessel tree based on 64 row CT data sets (mean scale 2.6) compared to 4 CT row data (mean scale 3.25) and 16 row CT data (mean scale 3.0), these

  4. How many CT detector rows are necessary to perform adequate three dimensional visualization?

    Introduction: The technical development of computer tomography (CT) imaging has experienced great progress. As consequence, CT data to be used for 3D visualization is not only based on 4 row CTs and 16 row CTs but also on 64 row CTs, respectively. The main goal of this study was to examine whether the increased amount of CT detector rows is correlated with improved quality of the 3D images. Material and Methods: All CTs were acquired during routinely performed preoperative evaluation. Overall, there were 12 data sets based on 4 detector row CT, 12 data sets based on 16 detector row CT, and 10 data sets based on 64 detector row CT. Imaging data sets were transferred to the DKFZ Heidelberg using the CHILI teleradiology system. For the analysis all CT scans were examined in a blinded fashion, i.e. both the name of the patient as well as the name of the CT brand were erased. For analysis, the time for segmentation of liver, both portal and hepatic veins as well as the branching depth of portal veins and hepatic veins was recorded automatically. In addition, all results were validated in a blinded fashion based on given quality index. Results: Segmentation of the liver was performed in significantly shorter time (p < 0.01, Kruskal-Wallis test) in the 16 row CT (median 479 s) compared to 4 row CT (median 611 s), and 64 row CT (median 670 s), respectively. The branching depth of the portal vein did not differ significantly among the 3 different data sets (p = 0.37, Kruskal-Wallis test). However, the branching depth of the hepatic veins was significantly better (p = 0.028, Kruskal-Wallis test) in the 4 row CT and 16 row CT compared to 64 row CT. The grading of the quality index was not statistically different for portal veins and hepatic veins (p = 0.80, Kruskal-Wallis test). Even though the total quality index was better for the vessel tree based on 64 row CT data sets (mean scale 2.6) compared to 4 CT row data (mean scale 3.25) and 16 row CT data (mean scale 3.0), these

  5. Multidetector-row CT for spinal diseases

    Multi-detector-row CT is called second stage helical CT because it produces multi-volume slices in a short time. We have observed sagittal, coronal images for spinal diseases by this CT. Thirty-three sagittal images out of 39 post-myelography for spinal diseases were good images of compression of the dural sac, and 8 coronal images post myelography were good images of compression of the dural sac and spinal nerve roots. We obtained 11 sagittal images for OPLL, and all images were nearly equal to that of tomography. However, spinal tumors and inflammatory diseases are more easily obtained using MRI. Multi-detector-row CT is useful for spinal degenerative diseases. (author)

  6. Experience with volumetric (320 rows) pediatric CT

    Sorantin, E., E-mail: erich.sorantin@medunigraz.at [Division of Pediatric Radiology, Department of Radiology, Medical University Graz (Austria); Riccabona, M. [Division of Pediatric Radiology, Department of Radiology, Medical University Graz (Austria); Stücklschweiger, G.; Guss, H. [Competence Centre for Medical Physics and Radiation Protection, Univ.-Hospital Graz (Austria); Fotter, R. [Division of Pediatric Radiology, Department of Radiology, Medical University Graz (Austria)

    2013-07-15

    The introduction of helical computer tomography (CT) and further progress to multi-slice CT enabled new applications. Most recent developments like the 320-row detector facilitate volume CT, which avoids the over-beaming effect of helical scanning. The 320-row multi-slice detector CT (MDCT) is based on a 16 cm detector; a special acquisition mode allows reconstructing 640 slices from these 16 cm. The shortest tube rotation time is in cardiac mode 0.35 s, otherwise 0.4 s and 0.5 s used. At 0.5 s the machine already reaches the maximum numbers of sub-second projections. Scan modes can be volume, helical and single slice mode. For image acquisition all dose savings technologies like variable tube position for scano-view, active collimation, automated exposure control, bolus and ECG tracking are available. Additionally special acquisition and post-processing techniques like head and body perfusion CT are ready for use on the console. For image reconstruction properties like filtered back projection as well as the latest development of iterative algorithms, an appropriate number of kernels and multi-planar reconstruction in all directions from the volume data at every increment are available. Volume CT allows sub second scanning of 16 cm z-coverage which, however, makes administration of intravenous contrast medium to “hit or miss” event. The aim of this paper is to present the application of volume CT to body scanning in children. Representative examples of neck, cardiac and skeletal investigations are given.

  7. Experience with volumetric (320 rows) pediatric CT

    The introduction of helical computer tomography (CT) and further progress to multi-slice CT enabled new applications. Most recent developments like the 320-row detector facilitate volume CT, which avoids the over-beaming effect of helical scanning. The 320-row multi-slice detector CT (MDCT) is based on a 16 cm detector; a special acquisition mode allows reconstructing 640 slices from these 16 cm. The shortest tube rotation time is in cardiac mode 0.35 s, otherwise 0.4 s and 0.5 s used. At 0.5 s the machine already reaches the maximum numbers of sub-second projections. Scan modes can be volume, helical and single slice mode. For image acquisition all dose savings technologies like variable tube position for scano-view, active collimation, automated exposure control, bolus and ECG tracking are available. Additionally special acquisition and post-processing techniques like head and body perfusion CT are ready for use on the console. For image reconstruction properties like filtered back projection as well as the latest development of iterative algorithms, an appropriate number of kernels and multi-planar reconstruction in all directions from the volume data at every increment are available. Volume CT allows sub second scanning of 16 cm z-coverage which, however, makes administration of intravenous contrast medium to “hit or miss” event. The aim of this paper is to present the application of volume CT to body scanning in children. Representative examples of neck, cardiac and skeletal investigations are given

  8. CT angiography of the neck: Value of contrast medium dose reduction with low tube voltage and high tube current in a 64–detector row CT

    Aim: To evaluate the feasibility of a low-dose contrast medium protocol for 64-detector row computed tomography angiography (CTA) of the neck using a low-tube-voltage/high-tube-current setting. Materials and methods: A phantom study was performed using 64-detector row spiral CT at multiple tube voltage and current settings. Iodine contrast medium attenuation curves were acquired by processing and used to select the best contrast medium-to-noise ratio (CNR). A prospective clinical study was then performed on 84 patients requiring neck CTA. Patients were randomly divided into two groups of 42. Group A was examined using the conventional imaging protocol (120 kV, 400 mAs) and group B was examined at 80 kV and 600 mAs along with a 50% reduction in contrast medium dose. The CT dose index-volume (CTDIvol), background noise (BN), and CNR were measured and statistically analysed. Various image quality criteria were evaluated by two senior radiologists using a qualitative five-point scale. Results: Comparing group B with A, CTDIvol decreased by 54% (B: 27.48 mGy, A: 59.11 mGy), however, the CNR increased by 50%. The mean attenuation, which was caused by venous streak artefacts, was significantly lower in group B than A. Qualitative image analysis found that all criteria were significantly better for group B than A. Conclusion: At 64-detector row spiral CT, the low-tube-voltage/high-tube-current with low-dose contrast medium protocol was superior to the conventional protocol regarding radiation dose, venous streak artefacts, and image quality, and is feasible for CTA of the neck

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

    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

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

    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)

  11. 320-detector row CT coronary angiography in patients with arrhythmia

    Objective: To evaluate the feasibility of CT coronary angiography (CTCA) in patients with arrhythmia using 320-detector row CT. Methods: Thirty-one patients with persistent atrial fibrillation and 8 patients with premature ventricular contraction were enrolled in this study. All patients underwent 320- detector row CTCA. CT image quality was evaluated with 4-point grading scale by two radiologists. Inter- observer agreement was evaluated by Kappa statistics. The radiation dose was calculated. Results: In total 510 coronary segments, 496 (97.2%) segments met diagnostic standard. The mean effective dose was (12.7±4.8) mSv in this study. There was a good agreement in image quality scoring between the two reviewers (Kappa = 0.72). Conclusion: 320-detector row CTCA is feasible in patients with atrial fibrillation and premature ventricular contraction. Arrhythmia may not be considered as a contraindication to CTCA. (authors)

  12. A study of chest CT examinations by 8 DAS multi detector row CT

    High-resolution CT images of 1.25 mm in slice thickness and routine images of 7.5 mm in slice thickness are usually obtained for lung examinations in our hospital. However these can't be obtained in one scan, and lead to increase CT dose. We considered that we could obtain their images in one scan and could decrease CT dose, if we scan the whole lung field by detector row 1.25 mm. We confirmed availability of thin detector row scans in consideration of Slice Sensitivity Profiles in z-direction (SSPz) and Standard Deviation (SD), and CT Dose Index (CTDI) under each condition. (author)

  13. Esophageal injuries: Spectrum of multidetector row CT findings

    Lutio di Castelguidone, Elisabetta de [Department of Radiology, I.N.T., IRCCS Fondazione G. Pascale, Via M. Semmola, I-80131 Naples (Italy)]. E-mail: e.delutio@virgilio.it; Merola, Stefanella [Department of Diagnostic Imaging, ' A. Cardarelli' Hospital, I-80131 Naples (Italy); Pinto, Antonio [Department of Diagnostic Imaging, ' A. Cardarelli' Hospital, I-80131 Naples (Italy); Raissaki, Maria [Department of Radiology, University Hospital of Iraklion, University of Crete Medical School, P.O. Box 1352, 711 10 Iraklion Crete (Greece); Gagliardi, Nicola [Department of Diagnostic Imaging, ' A. Cardarelli' Hospital, I-80131 Naples (Italy); Romano, Luigia [Department of Diagnostic Imaging, ' A. Cardarelli' Hospital, I-80131 Naples (Italy)

    2006-09-15

    Background: Aim of this study is to illustrate the multidetector row computed tomographic findings related to oesophageal injuries and their significance for therapeutic decisions. Method: From April 2002 to April 2005 we studied 16 patients with suspected oesophageal injury. Ten patients underwent standard chest radiograph, while five patients with suspected foreign body ingestion were submitted to cervical plain film and gastrografin swallow study. All 16 patients underwent multidetector row CT examination. Results: In six patients with cervical, thoracic and abdominal trauma, CT showed the presence of thoracic traumatic lesions and findings suggestive of perforation of the oesophagus. In five patients with foreign body ingestion cervical radiography was positive in only one case, while CT showed the presence of a foreign body in all cases. In three patients with post-intubation complications, CT showed the presence of perioesophageal fluid collection containing small gas bubbles in two cases and an oesophageal-aortic fistula in one case. In the remaining two patients with suspected spontaneous oesophageal perforation, CT demonstrated an oesophageal wall oedema and thickening in one case, and oesophageal fluid distension with perioesophageal small bubbles gas and fluid in the second case. Conclusion: Oesophageal injuries, when complicated with perforation, constitute a life-threatening condition. Knowledge of the CT signs of oesophageal injuries has important implications for the role of imaging at the time of initial diagnosis.

  14. New abdominal CT angiography protocol on a 16 detector-row CT scanner - first results

    Purpose. Purpose of this study was the implementation of a new abdominal CT angiography protocol on a 16 detector-row CT scanner and the comparison to selective catheter angiography.Methods. 76 patients with various vascular disorders underwent abdominal CT angiography on a recently developed 16 detector-row CT scanner using submillimeter slice collimation (16 x 0.75 mm). Results were compared with mesenteric and/or hepatic angiography in 17 patients performed during tumor embolization. Opacification was provided using individually tailored contrast application with a test bolus setting. To evaluate the contrast injection protocol density measurements within the vessel lumen were performed.Results. Diagnostic image quality was achieved in all patients with angiographic comparison (n = 17). Within the hepatic and mesenteric vasculature up to 4th generation vessels could be identified. Compared to selctive angiography CT angiography provided equivalent morphologic information up to the detectable vessel generation. With the applied contrast application regimen there were no significant differences in vessel enhancement along the abdominal aorta and iliac arteries.Conclusion. 16 detector-row CT enables whole abdominal angiographic studies with submillimeter resolution in a single breath-hold. The improved spatial resolution enables for high quality 3D visualization. Compared to invasive angiography, 16 detector-row CT reveals equivalent morphologic information. (orig.)

  15. d3D-CTA (dynamic 3D-CTA) for cerebral infarction using multi-detector row CT (MDCT)

    Since three-dimensional-CT angiography (3D-CTA) can demonstrate occlusion or stenosis of the arteries, it has been employed for the diagnosis of patients with cerebral infarction. However, it does not provide information on the blood-flow dynamics. We therefore developed a new technique, d3D-CTA (dynamic 3D-CTA), that yields 3D images of the vessels and hemodynamics. We assessed whether or not our technique could be applied to patients with cerebral infarction. We subjected 41 patients with cerebral infarction to d3D-CTA (17 lacunar infarctions, 14 cardioembolisms and 10 atherosclerotic infarctions). d3D-CTA was performed using a multi-detector row CT scanner with 64 detectors. Contrast medium was injected at a speed of 6 ml/s (a total volume of 30 ml). The scanning was performed for 30 sec with a scan delay of 5 sec. In all cases, we successfully developed d3D-CTA. The d3D-CTA provided us with information on the vascular structures, hemodynamics and cerebral perfusion. Although our technique, d3D-CTA, has some disadvantages such as a limited scan range (32 mm) and relatively high radiation dose, it does facilitate the acquisition of information on the vascular anatomy, flow dynamics on 3D images and cerebral perfusion. We conclude that d3D-CTA can be applied for the diagnosis and treatment of patients with cerebral infarction. (author)

  16. Coronal reformations of the chest on 64-row multi-detector row CT: Evaluation of image quality in comparison with 16-, 8- and 4-row multi-detector row CT

    Purpose: To evaluate image quality of coronal reformations of chest performed on 64-row MDCT in comparison with 16-, 8- and 4-row MDCT. Materials and methods: Consecutive patients who underwent pulmonary CT angiography using four different MDCT scanners were retrospectively studied with IRB approval: (1) n = 30, 64-row MDCT; (2) n = 30, 16-row MDCT; (3) n = 30, 8-row MDCT; (4) n = 30, 4-row MDCT. Coronal reformatted images (2 mm thickness and 2 mm intervals for 64-row MDCT; 5 mm thickness and 5 mm intervals for 16-, 8- and 4-row MDCT) were evaluated by consensus reading of two board-certified radiologists who were blinded to scanner type. The image quality of overall chest appearance and individual thoracic structures including heart, aorta and pulmonary arteries was graded using five-point scale. Grades from four different scanners were compared using Kruskal-Wallis test. A second evaluation was performed in 48 randomly selected patients (12 patients for each scanner). Reproducibility was assessed using weighted-kappa analysis. Result: Significant reproducibility was observed between the first and second evaluations in 48 patients both for image quality of overall chest (weighted kappa = 0.826) and each thoracic structure (mean weighted kappa = 0.803; range, 0.729-0.858). Image quality of overall chest and individual thoracic structures differed significantly among four different MDCT groups, with 64-row MDCT having the highest grades, followed by 16-, 8- and 4-row MDCT (mean grades for overall chest in each scanner: 3.9, 3.0, 2.4 and 1.9, respectively) (P < 0.0001 for overall chest and each thoracic structure). Conclusion: When comparing coronal reformations of chest using four different MDCT scanners, the 64-row MDCT had the highest image quality for overall chest appearance and individual thoracic structures, followed by 16-, 8- and finally 4-row MDCT

  17. Detection of myocardial perfusion defect with 320-row volume CT myocardial perfusion imaging

    Objective: To evaluate the feasibility of 320-row volume CT myocardial perfusion imaging (CT-MPI) in detecting myocardial perfusion defect. Methods: Fourteen patients with positive single-positron emission computed tomography myocardial perfusion imaging (SPECT-MPI) findings underwent both rest and adenosine stress 320-row volume CT-MPI. Rest and stress CT perfusion images were analyzed by employing dedicated software in 320-row CT workstation. Both SPECT-MPI and CT-MPI were evaluated for fixed and reversible perfusion defects using a 16-segment model (apex was excluded). The sensitivity, specificity of 320-row volume CT-MPI in detecting myocardial perfusion defect were evaluated by taking SPECT-MPI as a reference standard. Results: Both rest and stress 320-row volume CT-MPI were successfully performed in all patients. Thirty nine segments with fixed or reversible perfusion defects in all patients were depicted by SPECT-MPI, while 34 perfusion defects in 12 patients were identified by CT-MPI. The sensitivity, specificity of 320-row volume CT-MPI for detection of perfusion defects were 87.2%(34/39), 91.4% (169/185), respectively. Conclusion: 320-row volume CT-MPI has high sensitivity and specificity for detection of myocardial perfusion defects. (authors)

  18. Usefulness of multidetector-row CT (MD-CT) for assessment of coronary artery stenosis

    Coronary arteries stenosis were evaluated in 49 cases by volume rendering (VR) and partial maximum intensity projection (partial MIP) using multidetector-row CT (MD-CT). Left main trunk (LMT) and left anterior descending artery (LAD) were less affected by cardiac pulsation artifact and presented good images. Right coronary artery (RCA) was affected by cardiac pulsation artifact and image quality was inferior as compared to left coronary artery (LCA). It is suggested that MD-CT is useful for assessment of coronary artery stenosis, especially LCA. (author)

  19. Dosimetric evaluation of a 320 detector row CT scanner unit

    The technologic improvements in Multislice scanners include the increment in the X-ray beam width. Some new CT scanners are equipped with a 320 detector row which allows a longitudinal coverage of 160 mm and a total of 640 slices for a single rotation. When such parameters are used the length of the traditional pencil chamber (10 cm) is no more appropriate to measure the standard weighted computed tomography dose index (CTDIw) value. Dosimetric measurements were performed on a 640 slices Toshiba Aquilion One CT scanner using common instrumentation available in Medical Physics Departments. For the measurements in air, two different ionization chambers were completely exposed to the beam. Dosimeters showed an acceptable agreement in the measurements. To evaluate the actual shape of the dose profile strips of Gafchromic XRQA film were used. Films were previously calibrated on site. From the graphic response of the scanned film it is possible to evaluate the full width at half maximum (FWHM) of the dose profile which represent the actual beam width. Computed Tomography Dose Index (CTDI) and Dose Length Product (DLP) need to be changed when the beam width of the CT scanner is over 100 mm. To perform dose evaluation with the conventional instrumentation, two parameters should be considered: the average absorbed dose and the actual beam width. To measure the average absorbed dose, the conventional ionization chamber can be used. For the measurement of the width of the dose profile, Gafchromic XRQA film seemed to be suitable

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

    Atif N Khan

    2014-01-01

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

  1. Minimizing the acquisition phase in coronary CT angiography using the second generation 320-row CT

    We aimed to compare the radiation dose and image quality of a minimal phase window centered at 77% compared with a wide phase window in coronary CT angiography using the second-generation 320-row CT. Eighty patients with heart rate ≤75 bpm were retrospectively included. The first 40 patients underwent scanning with a wide phase window (65-85%), while the last 40 patients underwent scanning with a minimal phase window centered at 77%. Subjective image quality was graded using a 4-point scale (4=excellent). Image noise and contrast-to-noise ratio at the proximal segments were also analyzed. The mean effective dose was derived from the dose length product multiplied by a chest conversion coefficient (κ=0.014 mSv mGy-1 cm-1). Minimal phase window scanning centered at 77% reduced the radiation dose by 30% compared with wide phase window scanning (1.7 vs 2.4 mSv, p=0.0009). The subjective image quality showed no significant difference (3.75 vs 3.76, p=0.77). No significant difference was observed in the image noise, CT number, and contrast-to-noise ratio. Radiation dose could be reduced while maintaining image quality by use of a minimal phase window centered at 77% compared with a wide phase window in coronary CT angiography using the second generation 320-row CT. (author)

  2. Comparison of 64-row and 16-row multidetector CT in the perfusion CT evaluation of acute ischemic stroke patients receiving intravenous thrombolytic therapy

    Sillanpaa, Niko; Dastidar, Prasun; Soimakallio, Seppo [Tampere University Hospital, Medical Imaging Centre, PL 2000, Tampere (Finland); Rusanen, Harri [Oulu University Hospital, Department of Neurology, Oulu (Finland); Saarinen, Jukka T. [Tampere University Hospital, Department of Neurology, Tampere (Finland)

    2012-09-15

    Perfusion computed tomography (PCT) is increasingly performed in multimodal CT evaluation of acute ischemic stroke. We compared the technical quality of perfusion studies performed with a 16-row and a 64-row scanner and analyzed the differences between the scanners in their ability to detect perfusion defects. We analyzed retrospectively the clinical and imaging data of 140 consecutive acute (<3 h) stroke patients who underwent multimodal CT evaluation and received intravenous rtPA. Alberta Stroke Program Early CT Score (ASPECTS) was assigned to PCT maps. Clinical and imaging parameters were compared between the two scanners. There were more motion artifacts in the 16-row studies (p = 0.04), and the analysis software was able to completely correct significantly fewer of these (p < 0.001). Both ASPECTS levels were optimally covered in only 29% of the 16-row studies, whereas in the 64-row studies, both levels were invariably optimally visualized (p < 0.001). This significantly decreased the sensitivity of the 16-row scanner to detect perfusion defects in the upper ASPECTS level (p = 0.02). The 64-row scanner was able to detect more perfusion defects that were located entirely outside the ASPECTS regions (p = 0.03). There was no significant difference in the 3-month functional outcome. The 16-row scanner suffered from limited anatomic coverage that decreased the sensitivity to detect perfusion defects in the cranial parts of the middle cerebral artery region. The 16-row studies had poorer technical quality that was in part attributable to higher sampling frequency and smaller slice thickness making the imaging more sensitive to small-scale movement of the patient. (orig.)

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

    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.)

  4. Application of 64-detector computed tomography myelography in the diagnostics of the spinal canal

    Background. The most important imaging modality of the spine and spinal canal is magnetic resonance (MRI). In a relatively large group of patients with contraindications to MR, the alternative method is computed tomography myelography (myelo-CT). The development of multi-detector spiral CT, especially 64-detector scanners, could potentially increase the diagnostic possibilities of myelo-CT. Objectives. Evaluation of usefulness of 64-detector myelo-CT in diagnostics of the spinal canal. Material and Methods. Myelo-CT studies were performed with a 64-detector CT scanner in 31 patients (29 males, 2 females, age 17-71, mean age 31.9). The patients were referred with diagnoses of brachial plexus injury (27 cases), spinal canal stenosis (2 cases), suspected communication with fluid space in sacral region (1 case), and suspected intraspinal lesions after vertebral stabilization (1 case). A contrast medium (300 mg iodine/ml) was injected into the dural sac via sucoccipital (14 patients) or lumbar (17 patients) puncture. After that, a spiral acquisition (slice thickness 0.625 mm, pitch 0.9) was performed with a 64-detector CT scanner, followed by multiplanar MIP (Maximum Intensity Projection) reconstruction. In 26 patients, a comparison with operative results was performed. Results. Among the 27 patients with traumatic injury of the brachial plexus, nerve root lesions were revealed (preganglionic brachial plexus injury) in 14 patients, and in 13 cases myelo-CT was normal (postganglionic injury). In the 4 patients referred with diagnoses other than brachial plexus injury, myelo-CT contributed to therapeutic decisions, e.g. of reoperation in the patient with intraspinal haematoma, diagnosed on the basis of the myelo-CT scan. In the 14 patients with the features of preganglionic brachial plexus injury in myelo-CT, we analyzed C5-T1 nerve roots in detail on the side of the injury (overall 140 roots). We found a lack of the outlines or continuity of 57 roots in 13 patients

  5. Application of multi-detector row helical scanning to postmyelographic CT

    The advent of a multi-detector row helical CT has made it possible to attain images over a broader area with good spatial resolution. We assessed whether postmyelographic CT scans obtained using this system provided more information than conventional imaging techniques. Postmyelographic CT scans were preoperatively obtained in 46 patients using a multi-detector row helical CT system. Reconstructed images in the sagittal and coronal planes in all patients and curved reformation images along the dural sac in 37 patients were compared with myelograms and conventional postmyelographic CT scans. In 34 patients comparison was also made with MR images. The multi-detector row CT images demonstrated deformities of the dural sac more clearly than the other modalities in 39 of the 46 patients. They also provided the best visualization of nerve root abnormalities in 24 of the 46 patients and clearly revealed the presence of spurs in all 22 patients with spinal canal stenosis. Postmyelographic CT scans made using a multi-detector row helical CT system provide more information on the dural sac, nerve sleeves, and their contents than other imaging techniques. (orig.)

  6. Multidetector row CT study of percutaneous transhepatic intrahepatic portosystemic shunt

    Objective: To investigate imaging features of the liver, portal vein and hepatic vein or transhepatic inferior vena cava in patients with severe liver cirrhosis in multidetector row computed tomography (MDCT), and assess the feasibility, safety and clinical significance of percutaneous transhepatic intrahepatic portosystemic, shunt (PTIPS). Methods: Fifty patients with severe liver cirrhosis confirmed by clinical data and imaging examination were enrolled in this study. Simulation of intrahepatic portosystemic shunt by percutaneous transhepatic, approach is as follows. The right midaxillary line (the eighth oi ninth intercostal space) was selected as puncture point A the right branch of portal vein was puncture point B, transhepatic inferior vena cava was puncture point C, and the distal part of right portal vein was D. A-B-C connection is simulated as percutaneous transhepatic puncture tract, C-B-D connection is simulated as portosystemic shunt tract. After tri-phase contrast-enhanced CT scanning, postprocessing images through multiple planner reconstruction (MPR) were obtained. The data were indicated statistically by x-bar±s. And 9.5% confidence interval for mean was calculated. Anatomic relationship among the right portal vein, transhepatic inferior vena cava, hepatic artery and bile duct were analyzed for all patients. Results: The length of the needle (A-B-C) is (145.7±14.8) mm. The curvature of the needle (the angle of A-B line and B-C line) is (145.0±9.9) . The length of transhepatic shunt tract (B-C) is (42.7±7.2) mm. The length of the shunt tract (C-B-D) is (117.7±11.6) mm; The angle of the shunt tract (the angle of B-C line and B-D line) is (108.5±5.9)°. In 24/50 patients, transhepatic inferior vena cava locate in the dorsal of the right portal vein, in 26/50 patients they are in the same plane. In all patients, the right branches of hepatic artery and bile duct locate in the ventral of the right portal vein. Conclusion: The procedure of PTIPS is

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

    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

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

    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.)

  9. The structures mimicking aneurysm on 3-dimensional volume rendering CT angiography using a 16-row detector CT

    This study was conducted to identify the structures that can mimic aneurysm on CT angiography with using the 3-D volume rendering technique and a 16-row detector CT. This study examined 206 patients who underwent CT angiography with a 16-row detector CT from May 2003 to July 2004. For the CT angiography, the contrast media was injected at a rate of 4 cc per second. The scanning was then done when 5 seconds delay time had elapsed after the CT number of the common carotid artery had reached 150. The baseline images were obtained by reconstructing the row data with a kernel value of H31f, a slice thickness of 1 mm and an increment of 0.5 mm. Finally, the 3-D images were constructed by using a volume rendering technique. The structures that were confused with aneurysm on CT angiography were further evaluated by MPR or MIP to ascertain whether they were aneurysms. For comparison, digital subtraction angiography was done in 86 patients and surgery was done in 5 patients. On CT angiography, 51 patients did not show any abnormalities, and 80 patients showed definitive aneurysms, as was ascertained by their sizes, shapes and locations, or by the aneurysm clips only. The remaining 75 patients showed 90 aneurysm mimicking structures that were 35 infundibular dilatations or preaneurysmal blebs, 24 focal dilatations of the branches of the deep middle cerebral veins, 6 focal dilatations of the sphenoparietal sinuses adjacent to the middle cerebral artery, 18 focal dilatations of the inferior sagittal sinuses adjacent to the pericallosal artery and 7 low density calcifications of the vessel walls that were adjacent to the aneurysm-prevalent arteries. CT angiography based on volume rendering technique was able to identify the structures that were confused with aneurysm. Accordingly, careful observation is required for interpreting the reconstructing 3-D images since a wide variety of structures can be confused with aneurysm on CT angiography

  10. Three-dimensional CT angiographic assessment of pelvic and lower-extremity occlusive disease using single detector-row and multidetector-row CT scanners

    Three-dimensional CT angiography (3D-CTA) using a single detector-row CT (SDCT) scanner has become an important technique in the evaluation of the vascular system. A multidetector-row CT (MDCT) scanner, that is, a more advanced CT scanner which can acquire up to four channels of data simultaneously, has been recently introduced. With the use of this robust CT scanner, it is expected that more efficient 3D-CTAs will be obtained thanks to the superior temporal and spatial resolution provided by this technology. The purpose of this study was to assess the usefulness of 3D-CTA reconstructed from the data sets obtained using both SDCT and MDCT scanners, and to evaluate new software which was originally developed for the assessment of vascular wall pathology and vessel tortuosity. Twenty patients with pelvic arterial occlusive disease underwent 3D-CTA using a SDCT scanner. For stenoses and occlusions, 3D-CTA had a sensitivity of 93%, and a specificity of 89% as compared to digital subtraction angiography. Long anatomical range 3D-CT angiographic evaluations, from the pelvic artery to the lower legs, were performed in five patients with peripheral arterial occlusive disease using an MDCT scanner. All significant stenoses and occlusions were nicely depicted by the 3D-CTAs using the MDCT scanner. A new method for semiautomatically produced, curvedplanar reconstructed images along the vessel length based on a virtual CT endoscopic technique (CEV-CPR method) provided smoothly reformatted longitudinal images of the vessel. Using a new technique for assessing vessel tortuosity, we were able to quantitatively evaluate vessel tortuosity by calculating vessel curvature. In conclusion, 3D-CTA using SDCT and MDCT scanners and newly developed software provided useful qualitative and quantitative information concerning vascular pathology in patients with pelvic and lower-extremity occlusive disease. (author)

  11. Assessment of feasibility of endovascular treatment of ruptured intracranial aneurysms with 16-detector row CT angiography

    M. van der Jagt (Mathieu); H.Z. Flach (Zwenneke); H.L.J. Tanghe (Hervé); S.L.M. Bakker (Stef); M.G.M. Hunink (Myriam); P.J. Koudstaal (Peter Jan); A. van der Lugt (Aad)

    2008-01-01

    textabstractBackground: It is unclear whether 16-detector row CT angiography (CTA) can replace digital subtraction angiography (DSA) to assess the feasibility of endovascular treatment (EVT) in the acute phase after aneurysmal subarachnoid hemorrhage. Methods: We studied 80 consecutive patients with

  12. Feasibility of coronary calcium and stent image subtraction using 320-detector row CT angiography

    Fuchs, Andreas; Kühl, J Tobias; Chen, Marcus Y;

    2015-01-01

    severity leading to false-positive results. In a pilot study, we tested the feasibility of a new coronary calcium image subtraction algorithm in relation to reader confidence and diagnostic accuracy. METHODS: Forty-three patients underwent clinically indicated ICA and CCTA using a 320-detector row CT...

  13. 64-Row multidetector CT virtual hysterosalpingography. Findings in 2500 patients

    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

  14. Detectability of the appendix with multidetector-row CT scanning and multiplanar reconstruction

    Twenty-six consecutive patients with the clinical diagnosis of appendicitis underwent multidetector-row CT (MD-CT) in order to detect entire longitudinal configuration of the appendix. While axial CT failed to detect the appendix in 7 patients, multiplanar reconstruction (MPR) demonstrated a longitudinal tubular structure continuous from the cecal caput in 25 patients (96.2%), including 7 patients whose post-surgical pathology were available. It is summarized that scanning and MPR images are advantageous to finding inflammatory processes in the appendix when the diagnosis of appendicitis remains ambiguous even with US. (author)

  15. Pancreatico-colonicfistula-demonstrated by multidtector-row CT

    Srinivasan, Sivasubramanian; Subramanian, Manickam; Lim, Tze Chwan; Shenoy, Jagadish; Majumder, Arunesh [Khoo Teck Puat Hospital, Singapore (Singapore)

    2015-04-15

    A 25-year-old man presented to the emergency department with a history of corrosive (turpentine) ingestion. Clinically, the patient had metabolic acidosis and his total white cell count was 28600/mm{sup 3}. Computed tomography (CT) scan of the thorax and abdomen revealed diffuse thickening of the esophagus, stomach and duodenum. Minimal free fluid was present in the abdomen. The patient was first stabilised and step wise reconstruction of the gastro-intestinal tract was performed after esophagectomy, gastrectomy, pancreatic oduodenectomy, cholecystectomy, choledocho-jejenostomy and creation of a feeding jejenostomy.

  16. Analysis of main influence factors on coronary artery image quality with 64-multidetector row helical CT using a pulsating cardiac phantom

    Objective: To explore the main influence factors (heart rate, rotation speed, and reconstruction algorithm) on the image quality of coronary artery with 40 mm VCT (64-detector row helical CT) using a pulsating cardiac phantom. Methods: An adjustable pulsating cardiac phantom (GE) containing predetermined simulated coronary arteries was scanned using a 40 mm VCT (GE LightSpeed CT) with cardiac pulsating rates of 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100, 105, 110, and 115 beats per minute (bpm). The variable rotation speeds technique of 0.35 s, 0.40 s, and 0.45 s were used, respectively. The raw data were reconstructed using both one-sector and multi-sector reconstruction algorithm at optimal window of the R-R interval. The image quality score (IQS) was evaluated by two radiologists according to the same evaluation standard of reformated image. The correlation between heart rate (HR), roation speed, reconstruction algorithm, and IQS were analyzed. The IQS as independent variable and the HR, rotation speed, reconstruction algorithm as dependent variables were analyzed by multiple linear regression analysis. Results: The heart rate and the reconstruction algorithm had significant influence on IQS. The rotation speed (0.35s, 0.40 s, and 0.45 s) didn't have significant influence on IQS. There was linear regression relationship between heart rate, reconstruction algorithm and IQS (P<0.01). The equation of multiple regression was IQS=5.154-0.046 x (HR) + 0.500 x (reconstruction algorithm). The multi-sector reconstruction algorithm improved the image quality than one-sector did. Conclusion: The main influence factors on the image quality of coronary artery can be evaluated with 40 mm VCT using a pulsating cardiac phantom. It plays an important role in clinical research and application. (authors)

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

    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

  18. Computed tomography dose assessment for a 160 mm wide, 320 detector row, cone beam CT scanner

    Computed tomography (CT) dosimetry should be adapted to the rapid developments in CT technology. Recently a 160 mm wide, 320 detector row, cone beam CT scanner that challenges the existing Computed Tomography Dose Index (CTDI) dosimetry paradigm was introduced. The purpose of this study was to assess dosimetric characteristics of this cone beam scanner, to study the appropriateness of existing CT dose metrics and to suggest a pragmatic approach for CT dosimetry for cone beam scanners. Dose measurements with a small Farmer-type ionization chamber and with 100 mm and 300 mm long pencil ionization chambers were performed free in air to characterize the cone beam. According to the most common dose metric in CT, namely CTDI, measurements were also performed in 150 mm and 350 mm long CT head and CT body dose phantoms with 100 mm and 300 mm long pencil ionization chambers, respectively. To explore effects that cannot be measured with ionization chambers, Monte Carlo (MC) simulations of the dose distribution in 150 mm, 350 mm and 700 mm long CT head and CT body phantoms were performed. To overcome inconsistencies in the definition of CTDI100 for the 160 mm wide cone beam CT scanner, doses were also expressed as the average absorbed dose within the pencil chamber (D-bar100). Measurements free in air revealed excellent correspondence between CTDI300air and D-bar100air, while CTDI100air substantially underestimates CTDI300air. Results of measurements in CT dose phantoms and corresponding MC simulations at centre and peripheral positions were weighted and revealed good agreement between CTDI300w, D-bar100w and CTDI600w, while CTDI100w substantially underestimates CTDI300w. D-bar100w provides a pragmatic metric for characterizing the dose of the 160 mm wide cone beam CT scanner. This quantity can be measured with the widely available 100 mm pencil ionization chamber within 150 mm long CT dose phantoms. CTDI300w measured in 350 mm long CT dose phantoms serves as an appropriate

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

    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.

  20. [Multidetector row CT in assessment of coronary artery calcification on hemodialisis].

    Caro, P; Delgado, R; Dapena, F; Núñez, A

    2007-01-01

    Vascular calcification is a strong predictor of cardiovascular and all-cause mortality. Coronary artery calcification is more frequent, more extensive and progresses more rapidly in CKD than in general population. They are also considered a marker of coronary heart disease, with high prevalence and functional significance. It suggests that detection and surveillance may be worthwhile in general clinical practice. New non-invasive image techniques, like Multi-detector row CT, a type of spiral scanner, assess density and volume of calcification at multiple sites and allow quantitative scoring of vascular calcification using calcium scores analogous to those from electron-beam CT. We have assessed and quantified coronary artery calcification with 16 multidetector row CT in 44 patients on hemodialysis and their relationship with several cardiovascular risk factors. Coronary artery calcification prevalence was of 84 % with mean calcium score of 1580 +/- 2010 ( r 0-9844) with calcium score > 400 in 66% of patients. It was usually multiple, affecting more than two vessels in more than 50%. In all but one patient, left anterior descending artery was involved with higher calcium score level at right coronary artery. Advanced age, male, diabetes, smoking, more morbidity, cerebrovascular disease previous, and calcium-binders phosphate and analogous vitamin D treatment would seem to be associated with coronary artery calcification. Coronary artery calcification is very frequent and extensive, usually multiple and associated to modifiable risk factors in hemodialysis patients. Multi-detector-row CT seems an effective, suitable, readily applicable method to assess and quantify coronary artery calcification. PMID:18336102

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

    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.)

  2. Automatic tube current modulation for volume scan in a 320-detector row CT scanner

    The x-y plane combined with z-axis automatic tube current modulation (ATCM) technique is one of the most comprehensive approaches to CT dose reduction because the radiation dose is adjusted according to patient attenuation in three dimensions. The 320-detector row CT scanner has the widest scan range (16 cm) within one axial rotation and equips with volume scan ATCM (VS-ATCM) mode. Special attention is needed while utilizing VS-ATCM mode in CT acquisitions especially scanning different anatomical regions, such as neck and shoulder in a single volume. However, the mechanism of VS-ATCM of the 320-detector row CT scanner remains unclear. This study aims to evaluate the performance of VS-ATCM mode in a 320-detector row CT scanner. A phantom set consists of three simple-shaped phantoms was scanned with the VS-ATCM mode. A solid-state detector was inserted into the central position of the phantom set to measure the real-time dose profiles at seven positions within five scan volumes. The effective tube-current time product of each slice was recorded. The standard deviation of the CT numbers measured at each image slice was used as a noise measurement. The performance of helical scan ATCM (HS-ATCM) mode was in comparison of VS-ATCM mode. The results indicated that VS-ATCM mode can provide a less dose CT scanning to a patient but resulted in a higher image noise in comparison with those of HS-ATCM mode. In clinical practice, radiologists or radiological technologists should pay more attention on the volume position when using VS-ATCM mode for patient imaging. Our experience can be a reference to others for implementation of clinical practices. -- Highlights: •Real-time dose profiles were measured for volume-scan ATCM mode. •Comparison of tube current variation between volume- and helical-scan ATCM modes. •Comparison of image noise between volume- and helical-scan ATCM modes

  3. Coronary arteriovenous fistula complicated with dilated pulmonary sinus confirmed by multidetector-row CT

    Kim, Dong Hun [Chosun University Hospital, Gwangju (Korea, Republic of); Kim, Sung Koo; Bang, Duk Won; Yum, Wook [Soonchunhyang University Hospital, Bucheon (Korea, Republic of); Ryu, Sang Wan [Chonnam National University Hospital, Gwangju (Korea, Republic of)

    2005-07-15

    Congenital coronary arteriovenuos fistula (CAVF) is a rare condition which is characterized by abnormal communication of the coronary artery with the right ventricle, right atrium, left atrium, left ventricle or pulmonary artery. In this paper, we report a case of a 68-year-old woman complaining of resting chest pain for one week. Initially, after performing a coronary arteriogram, the case was diagnosed as a CAVF combined with a pulmonary artery aneurysm. However, a multidetector-row CT (MDCT) was also performed, and the structure initially diagnosed as a pulmonary artery aneurysm was identified as a dilated pulmonary sinus. Subsequently, the patient was treated successfully with a simple ligation.

  4. Multiple detector-row CT angiography of the renal and mesenteric vessels

    Computed tomography angiography (CTA) of the abdomen with multiple detector-row computed tomography (MD-CT) is an effective technique for minimally invasive imaging of the renal arteries and the visceral vasculature. This article reviews the clinical and technical aspects of MD-CT angiography in terms of image acquisition and reconstruction parameters, contrast medium application, and three-dimensional visualization with special attention to renal and mesenteric vascular imaging. Because of its high sensitivity to detect renal artery stenosis on the one hand, and because a normal renal CTA virtually excludes the presence of a significant renal artery stenosis on the other hand, renal CTA plays a useful role in the management of patients with suspected renovascular hypertension. Mesenteric CTA is a useful tool for visualizing normal vascular anatomy and its variants--particularly in the setting of organ transplantation. Vascular pathology, e.g. atherosclerotic disease (abdominal angina), or aneurysms of the visceral arteries are reliably assessed with CTA. Mesenteric CTA is an invaluable adjunct to abdominal CT in the setting of abdominal emergencies, because of its ability to detect the causes of acute intestinal ischemia (superior mesenteric artery embolism or thrombosis, superior mesenteric vein thrombosis). Accurate timing of the CTA acquisition and the subsequent parenchymal phase acquisition relative to the contrast medium transit time is critical to obtain excellent image quality in double-pass abdominal CT acquisitions

  5. Diagnostic Performance of Transluminal Attenuation Gradient and Noninvasive Fractional Flow Reserve Derived from 320-Detector Row CT Angiography to Diagnose Hemodynamically Significant Coronary Stenosis

    Ko, Brian S; Wong, Dennis T L; Nørgaard, Bjarne L; Leong, Darryl P; Cameron, James D; Gaur, Sara; Marwan, Mohamed; Achenbach, Stephan; Kuribayashi, Sachio; Kimura, Takeshi; Meredith, Ian T; Seneviratne, Sujith K

    2015-01-01

    Purpose To compare the diagnostic performance of 320-detector row computed tomography (CT) coronary angiography-derived computed fractional flow reserve (FFR; FFRCT), transluminal attenuation gradient (TAG; TAG320), and CT coronary angiography alone to diagnose hemodynamically significant stenosis...

  6. A prospective study comparing different iodine concentrations for triphasic multidetector row CT of the upper abdomen

    Objectives: To investigate the effect of different iodine concentrations at either constant injection or iodine administration rates but constant total iodine load on contrast enhancement of liver, pancreas and spleen by multidetector row CT. Materials and methods: One hundred and twenty consecutive patients (70 ± 6 years) underwent triphasic liver CT at a four-channel multidetector-row CT using the non-ionic contrast medium iopromide. Patients were divided into six equal groups-I: 150 ml, 240 mg/ml at 4 ml/s; II: 120 ml, 300 mg/ml at 4 ml/s; III: 97.3 ml, 370 mg/ml at 4 ml/s; IV: 150 ml, 240 mg/ml at 5 ml/s; V: 120 ml, 300 mg/ml, 60 ml at 6 ml/s, 60 ml at 3 ml/s; VI: 97.3 ml, 370 mg/ml at 3.3 ml/s. ROIs were measured in the liver, the pancreas, and the spleen in unenhanced, arterial, portal venous, and equilibrium phase. Results: At a constant injection rate of 4 ml/s, pancreatic enhancement over baseline only in the arterial phase was significantly higher at 370 mg/ml (58 ± 15 HU versus 59 ± 18 HU versus 74 ± 20 HU for groups I-III, respectively (p < 0.02)). Comparison of different iodine concentrations at constant iodine administration rate (groups II, IV and VI) and of all six protocols revealed no significant differences at either phase. Conclusions: At a constant iodine load and constant injection rates, the high-iodinated contrast agent iopromide at 370 mg/ml improves pancreatic enhancement in the arterial phase. At constant iodine load and constant iodine administration rates, there is no significant effect of different iodine concentrations

  7. Ex vivo coronary atherosclerotic plaque characterization with multi-detector-row CT

    Multi-detector-row CT angiography (CTA) is a new technology that allows for non-invasive investigation of coronary atherosclerosis in patients. The relation between the morphology of atherosclerotic plaques assessed by CTA and histopathology is unknown. We investigated 11 human cadaver heart specimens. A mixture of methylcellulose and CT contrast media was injected into the coronary arteries to achieve in-vivo-like contrast enhancement within the coronary artery lumen. The morphologic pattern of atherosclerotic lesions found on CTA images and the tissue attenuation of non-calcified plaques were determined. After CTA imaging, atherosclerotic lesions in the coronary arteries were macroscopically identified and characterized histopathologically according to American Heart Association criteria. A total of 50 and 40 lesions were found macroscopically and by CTA, respectively. Thirty-three lesions could have been compared directly. The sensitivity of CTA compared with macroscopic detection of atheromas, fibroatheromas, fibrocalcified, and calcified lesions was 73, 70, 86, and 100%, respectively. The mean CT attenuation of predominantly lipid-rich and fibrous-rich plaques was significantly different (47±9 and 104±28 HU, respectively; p<0.01). Atherosclerotic coronary plaques detected by CTA may represent different stages of coronary atherosclerosis. The tissue attenuation of non-calcified plaques may allow for assessment of their predominant component. (orig.)

  8. Evaluation of different small bowel contrast agents by multi - detector row CT

    Wang, Yong-Ren; Yu, Xiao-Li; Peng, Zhi-Yi

    2015-01-01

    Objective: This study aims to evaluate the effects of different oral small bowel contrast agents towards the intestinal dilatation and intestinal wall structure exhibition by the abdominal multi - detector row CT (MDCT) examination. Methods: 80 patients were performed the whole abdominal CT examination, then randomly divided into four groups, with 20 patients in each group. 45 minutes before the CT examination, the patients were served with a total of 1800 ml pure water, pure milk, dilute lactulose solution and isotonic mannitol solution, respectively. Results: The images were blinded read by two experienced abdominal radiologists in the workstation, the cross-sectional diameters of duodenum, jejunum, proximal and terminal ends of ileum of each patient were measured, then the analysis of variance was performed to analyze the differences in the intestinal dilatation among the experimental groups. The scoring method was used to score the intestinal dilatation and intestinal structure exhibition. The diluted lactulose solution and 2.5% mannitol exhibited the best intestinal dilation degrees. Similarly, the diluted lactulose solution and 2.5% mannitol exhibited the highest scores in the entire small bowel dilatation degree and intestinal structure exhibition. Conclusions: 2.5% osmotic mannitol and the diluted lactulose solution enabled the full dilatation of small bowel, and could clearly exhibit the wall structure. PMID:26629131

  9. Initial study of optimal reconstruction windows in 320-detector row CT coronary angiography

    Objective: To investigate the optimal reconstruction windows for coronary angiography using 320-detector row dynamic volume CT (DVCT) and evaluate their effects on image quality, radiation dose and diagnostic accuracy. Methods: From 77 patients [mean heart rate (70±13) bpm, range: 46- 102 bmp] were scanned with retrospective ECG-gating 320-detector row DVCT. The relationship between heart rate and optimal reconstruction windows was analyzed. From 53 patients [mean heart rate (75± 11) bpm, range: 57-114 bpm] were scanned with prospective ECG-gating 320-detector row DVCT. The effects of prospective ECG-gating on image quality, radiation dose and diagnostic accuracy were evaluated. Friedman test was performed for image quality scores in random groups. Linear regression and Spearman correlation were performed to test bivariate data. Results: The proportion of systolic duration in the cardiac cycle increased significantly with higher heart rate (r=0.78, P 90 bpm, 35%-50%. Compared with retrospective ECG-gating, prospective ECC-gating which preset reconstruction windows according to the phases mentioned above, could decrease radiation dose [(6.1±3.8) vs (12.4± 7.0) mSv], without deteriorating the image quality (t=6.5, P<0.01). However, in higher heart rate, the radiation dose of prospective ECG-gating DVCT was still higher (r=0.64, P<0.01). Conclusions: DVCT can provide high image quality in a wide range of heart rate with prospective ECG gating. It is still recommended to control heart rate strictly since the radiation dose increases significantly in high heart rate. (authors)

  10. A novel iterative reconstruction algorithm allows reduced dose multidetector-row CT imaging of mechanical prosthetic heart valves

    Habets, Jesse; Symersky, Petr; de Mol, Bas A. J. M.; Willem P Th M Mali; Leiner, Tim; Budde, Ricardo P.J.

    2011-01-01

    Multidetector-row CT is promising for prosthetic heart valve (PHV) assessment but retrospectively ECG-gated scanning has a considerable radiation dose. Recently introduced iterative reconstruction (IR) algorithms may enable radiation dose reduction with retained image quality. Furthermore, PHV image quality on the CT scan mainly depends on extent of PHV artifacts. IR may decrease streak artifacts. We compared image noise and artifact volumes in scans of mechanical PHVs reconstructed with conv...

  11. Volumetric Measurements of Lung Nodules with Multi-Detector Row CT: Effect of Changes in Lung Volume

    Goo, Jin Mo; Kim, Kwang Gi; Gierada, David S.; Castro, Mario; Bae, Kyongtae T.

    2006-01-01

    Objective To evaluate how changes in lung volume affect volumetric measurements of lung nodules using a multi-detector row CT. Materials and Methods Ten subjects with asthma or chronic bronchitis who had one or more lung nodules were included. For each subject, two sets of CT images were obtained at inspiration and at expiration. A total of 33 nodules (23 nodules ≥ 3 mm) were identified and their volume measured using a semiautomatic volume measurement program. Differences between nodule volu...

  12. Comparison among ultrasonography, multidetector-row CT and MRA for precise diagnosis of carotid stenosis

    We evaluated lesions at the common carotid artery bifurcation and in the internal carotid artery of patients with carotid stenosis employing carotid ultrasonography, multidetector-row CT (MDCT) and magnetic resonance angiography (MRA). We calculated the degree of stenosis with both the area methods and the North American Symptomatic Carotid Endarterectomy Trial (NASCET) methods. The findings of MDCT and MRA were analyzed with reconstruction images as the multiplanar reconstruction (MPR) and maximum intensity projection (MIP). In the short axis area method, we recognized a strong correlation in stenosis rates between MDCT and MRA, and between MRA and ultrasonography. In the NASCET methods, a correlation of stenosis rates was noted only between MDCT and MRA. We recognized a correlation only between MRA and ultrasonography by the short axis area method in the calcification group. It is inferred that MDCT is as useful as the other two methods. (author)

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

    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

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

    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

  15. Carotid artery wall thickness: comparison between sonography and multi-detector row CT angiography

    Saba, Luca [University of Cagliari, Department of Radiology, Policlinico Universitario, Cagliari (Italy); Sanfilippo, Roberto; Montisci, Roberto [Policlinico Universitario, Department of Vascular Surgery, Cagliari (Italy); Mallarini, Giorgio [University of Cagliari, Department of Radiology, Policlinico Universitario, Cagliari (Italy); Ospedale San Giovanni di Dio, Institute of Radiology, Cagliari (Italy)

    2010-02-15

    Prospective studies have shown that an increased thickness of the carotid wall is a significant predictor of coronary and cerebrovascular complications. Our purpose was to assess the agreement between multi-detector row computed tomography (CT) angiography (MDCTA) and colour Doppler ultrasound (CD-US) in measuring carotid artery wall thickness (CAWT) and the intima-media thickness (IMT). Altogether, 97 subjects (age range 64-84 years) were prospectively analysed using a four-detector row CT and a sonographic scanner. In total, 46 subjects had shown cerebral ischaemic symptoms. CAWT and IMT were measured in each patient using MDCTA and CD-US (by applying a digital calliper), respectively. Continuous data were described as the mean value {+-} standard deviation and were compared using the Mann-Whitney U test. A p value <0.05 was considered significant. Bland-Altman statistics was employed to measure the agreement between MDCTA and CD-US. CAWT ranged from 0.5 to 1.53 mm, with a mean value of 0.9072 mm. IMT ranged from 0.46 to 1.5 mm, with a mean value of 0.8839 mm. By analysing the Bland-Altman plot, we observed an excellent agreement between CD-US and MDCTA with a bias between methods of 0.023 {+-} 0.0424 mm. A limit of agreement from -0.06 to 0.106 was recorded. Correlation coefficient r was 0.9855 (95% confidence interval 0.9808-0.989). Mann-Whitney U test indicated a p value of 0.377. Obtained results indicated a significant agreement between MDCTA and CD-US in the measurement of CAWT and IMT. (orig.)

  16. Carotid artery wall thickness: comparison between sonography and multi-detector row CT angiography

    Prospective studies have shown that an increased thickness of the carotid wall is a significant predictor of coronary and cerebrovascular complications. Our purpose was to assess the agreement between multi-detector row computed tomography (CT) angiography (MDCTA) and colour Doppler ultrasound (CD-US) in measuring carotid artery wall thickness (CAWT) and the intima-media thickness (IMT). Altogether, 97 subjects (age range 64-84 years) were prospectively analysed using a four-detector row CT and a sonographic scanner. In total, 46 subjects had shown cerebral ischaemic symptoms. CAWT and IMT were measured in each patient using MDCTA and CD-US (by applying a digital calliper), respectively. Continuous data were described as the mean value ± standard deviation and were compared using the Mann-Whitney U test. A p value <0.05 was considered significant. Bland-Altman statistics was employed to measure the agreement between MDCTA and CD-US. CAWT ranged from 0.5 to 1.53 mm, with a mean value of 0.9072 mm. IMT ranged from 0.46 to 1.5 mm, with a mean value of 0.8839 mm. By analysing the Bland-Altman plot, we observed an excellent agreement between CD-US and MDCTA with a bias between methods of 0.023 ± 0.0424 mm. A limit of agreement from -0.06 to 0.106 was recorded. Correlation coefficient r was 0.9855 (95% confidence interval 0.9808-0.989). Mann-Whitney U test indicated a p value of 0.377. Obtained results indicated a significant agreement between MDCTA and CD-US in the measurement of CAWT and IMT. (orig.)

  17. Xenon/CT blood flow mapping of the liver using multidetector-row computed tomography. Compensation of respiratory misregistration by volume data

    For improvement in the accuracy of xenon/CT blood flow mapping of the liver, this study was conducted to assess whether volume-data obtained by multidetector-row helical CT could compensate for the slice misregistration caused by inconstant breath depth. Using imaging phantoms scanned on both multidetector-row and single-detector CT, suitable parameters were decided. In the phantom studies, axial scan with multidetector-row CT showed significantly greater variance of CT value than that of single detector row CT (SDCT). On multidetector-row CT, variances of the CT values maintained in low (80 kV) tube voltage, which is advantageous for detecting subtle enhancement of the liver. Images reconstructed with 10-mm thickness showed smaller variance than those of 5-mm thickness on low-pitch helical scan. Remarkable helical artifacts were seen on the high-pitch helical scan. Following the phantom studies, 7 examinees were scanned using xenon/CT with a predetermined scan protocol (80 kV, collimation 5 mm, thickness 10 mm, low-pitch helical scan). In all cases, slice compensation was necessary and was successfully performed. The number of pixels which constituted blood flow map increased after the compensation. No patients showed any significant adverse effects. In conclusion, multidetector-row helical CT has the potential for providing accurate quantification of xenon/CT blood flow mapping of liver by compensating for respiratory misregistration. (author)

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

    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.

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

    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.

  20. Low dose 320-row CT for left atrium and pulmonary veins imaging—the feasibility study

    Objective: To evaluate the feasibility of low dose target-CTA volume scan for left atrium and pulmonary veins imaging using 320-row CT. Methods: Forty-two patients (females 12, males 30; mean age 55.2 years; mean body mass index (BMI) 25.7 kg/m2) with persistent or intermittent atrial fibrillation before catheter ablation were enrolled in this study. Scan protocol was target-CTA volume scan under prospective ECG-gating. The target of the exposure was only set at 40% of the R–R interval (which was at the left atrium maximal volume). The exposure time was minimal setting (350 ms). Tube voltage 100 kV (BMI ≤ 25 kg/m2) or 120 kV (BMI > 25 kg/m2), tube current 350–420 mA, and field of view of 180 mm × 180 mm–200 mm × 200 mm were used. The scanning range was from the level of the tracheal bifurcation to the diaphragm, and enabled to cover the left atrium and central pulmonary veins (120–140 mm). All of patients were divided into two groups according kV setting (100 kV and 120 kV). The image quality (good, moderate and poor) was evaluated by two reviewers. The CT-attenuation, image noise and contrast to noise ratio (CNR) of left atrium and every pulmonary vein branch were evaluated, respectively. The effective dose (ED) was calculated using a conversion coefficient for the chest 0.017. Results: Of 42 patients, the image quality was good in 26 cases (62%) and moderate in 16 cases (38%). There was no statistical difference in the CT-attenuation and CNR of left atrium and central pulmonary veins between the two groups (P > 0.05). The mean ED was 1.90 ± 0.19 mSv (range 1.57–2.25 mSv) in 100 kV group, and 3.83 ± 0.31 mSv (range 3.39–4.54 mSv) in 120 kV group. Conclusions: The low dose target-CTA volume scan is feasible in pulmonary veins and left atrium imaging using 320-row CT. Slim patients can be scanned at 100 kV setting without loss of image quality.

  1. Whole-brain CT digital subtraction angiography of cerebral dural arteriovenous fistula using 320-detector row CT

    The purpose of this study was to evaluate the usefulness of CT digital subtraction angiography (CTDSA) by using 320-detector row CT in the diagnosis and classification of cerebral dural arteriovenous fistula (dAVF) and comparing it with DSA as the standard reference. A total of 29 CTDSA/DSA from 25 patients with dAVF were retrospectively evaluated by two neuroradiologists. The presence, Cognard classification, and feeding arteries of dAVFs on CTDSA were assessed according to DSA. DSA depicted 33 dAVFs in 28 cases. By consensus reading, CTDSA correctly detected 32 dAVFs in 27 cases and properly graded 31 lesions. The intermodality agreement for the presence and classification of dAVFs was excellent (kappa = 0.955 and 0.921, respectively). CTDSA detected 77 of 109 feeding arteries (70.6 %) in 25 cases. The intermodality agreement for the feeding arteries was good (kappa = 0.713). Although CTDSA is limited in temporal and spatial resolution in comparison with DSA, it is an effective non-invasive tool for the detection and classification of dAVF. (orig.)

  2. Overbeaming and overlapping of volume-scan CT with tube current modulation in a 320-detector row CT scanner

    The purpose of this study was to evaluate the performance of volume scan tube current modulation (VS-ATCM) with adaptive iterative dose reduction 3D (AIDR3D) technique in abdomen CT examinations. We scanned an elliptical cone-shaped phantom utilizing AIDR3D technique combined with VS-ATCM mode in a 320-detector row CT scanner. The image noise distributions with conventional filtered back-projction (FBP) technique and those with AIDR3D technique were compared. The radiation dose profile and tube current time product (mAs) in three noise levels of VS-ATCM modes were compared. The radiation beam profiles of five preset scan lengths were measured using Gafchromic film strips to assess the effects of overbeaming and everlapping. The results indicated that the image noises with AIDR3D technique was 13–74% lower than those in FBP technique. The mAs distributions can be a prediction for various abdominal sizes when undergoing a VS-ATCM mode scan. Patients can receive the radiation dose of overbeaming and overlapping during the VS-ATCM mode scans. - Highlights: • Noise reduction with AIDR3D in VS-ATCM is 13–74%. • We provide mAs prediction in VS-ATCM for all sizes. • We observe the effect of overbeaming and overlapping

  3. Whole-brain CT digital subtraction angiography of cerebral dural arteriovenous fistula using 320-detector row CT

    Fujiwara, Hirokazu; Momoshima, Suketaka; Kuribayashi, Sachio [Keio University, Department of Diagnostic Radiology, School of Medicine, Tokyo (Japan); Akiyama, Takenori [Keio University, Department of Neurosurgery, School of Medicine, Tokyo (Japan)

    2013-07-15

    The purpose of this study was to evaluate the usefulness of CT digital subtraction angiography (CTDSA) by using 320-detector row CT in the diagnosis and classification of cerebral dural arteriovenous fistula (dAVF) and comparing it with DSA as the standard reference. A total of 29 CTDSA/DSA from 25 patients with dAVF were retrospectively evaluated by two neuroradiologists. The presence, Cognard classification, and feeding arteries of dAVFs on CTDSA were assessed according to DSA. DSA depicted 33 dAVFs in 28 cases. By consensus reading, CTDSA correctly detected 32 dAVFs in 27 cases and properly graded 31 lesions. The intermodality agreement for the presence and classification of dAVFs was excellent (kappa = 0.955 and 0.921, respectively). CTDSA detected 77 of 109 feeding arteries (70.6 %) in 25 cases. The intermodality agreement for the feeding arteries was good (kappa = 0.713). Although CTDSA is limited in temporal and spatial resolution in comparison with DSA, it is an effective non-invasive tool for the detection and classification of dAVF. (orig.)

  4. Study on scan conditions in the chest by four multi detector-row CT

    In our hospital, Toshiba's Aquilion (AQ) and Siemens' Volume Zoom (VZ) that are both four multi detector-row CT (MDCT) are working at present. In the lung CT, when pulmonary nodules or diffuse lung diseases are detected on CT images obtained by the use of beam collimation of 2.0 mm x 4 in AQ or 2.5 mm x 4 in VZ, the patient needs additional scans by using thinner beam collimation. However, this technique involves a problem that cannot scan the same target region as the first examination. High-resolution CT (HRCT) is generally defined to an image obtained by slice thickness of 1 mm to 3 mm. In this paper, however, we especially refers HRCT as an image obtained by slice thickness of 1 mm or less in the case of acquiring more detailed patient's data. Beam collimation of two MDCT scanners was set to 1.0 mm x 4 in order to efficiently employ a feature of MDCT that images of various slice thickness obtained by one scan can be reconstructed. We compared the images reconstructed from 5 mm slice-thickness images and 1 mm slice-thickness images in terms of changing of standard deviation (SD) and the occurrence of artifacts. As the results, the increase of SD and streak artifacts were confirmed under some conditions. The beam collimation of 1 mm x 4 needed to increase helical pitch, allowing for the patient's breath-holding time. We conclude to be useful for setting the beam collimation to 1 mm x 4, considering the reduction of the patient's exposure dose, the improvement of shape reappearance, and a shortening in examination time. (author)

  5. Effect of saline flush on enhancement of proximal and distal segments using 320-row coronary CT angiography

    Tomizawa, Nobuo, E-mail: tomizawa-tky@umin.ac.jp [Department of Radiology, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan); Suzuki, Fumio; Akahane, Masaaki [Department of Radiology, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan); Torigoe, Rumiko [Toshiba Medical Systems Corporation, Tokyo Metropolitan Regional Office, 1-6, Tsukuda 2-Chome, Chuo-ku, Tokyo 104-0051 (Japan); Kiryu, Shigeru [Department of Radiology, Institute of Medical Science, The University of Tokyo, 4-6-1 Shirokanedai, Minato-ku, Tokyo 108-8639 (Japan); Ohtomo, Kuni [Department of Radiology, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan)

    2013-08-15

    Objective: To investigate the effect of saline flush on coronary CT angiography of proximal, middle, and distal coronary artery segments, using 320-row CT, and to compare two injection duration protocols as to amount of contrast in the right heart chambers. Methods: This retrospective study was approved by the local ethics committee, and the requirement for informed consent to participate in this study was waived. The final study group included 108 patients who underwent coronary CT angiography. The first 36 patients received contrast medium without saline flush (group 1); the next 36 patients received contrast medium for 14 s and saline flush (group 2); the last 36 patients received contrast medium for 12 s and saline flush (group 3). The CT number, noise, contrast-to-noise ratio (CNR), and number of segments with a CT number greater than 325 Hounsfield units (HU) were recorded for proximal, middle, and distal segments. Results: The CT numbers and the CNR in groups 2 and 3 were significantly higher than that in group 1 (p < 0.005); the difference between groups 2 and 3 was not significant. The proportion of segments greater than 325 HU improved with saline flush (p < 0.05), with a larger improvement in the distal segments. Conclusions: Saline flush improves enhancement and CNR of coronary arteries, particularly of distal segments, in coronary CT angiography using 320-row CT. An average contrast medium injection of 44 mL was feasible using a saline flush.

  6. Effect of saline flush on enhancement of proximal and distal segments using 320-row coronary CT angiography

    Objective: To investigate the effect of saline flush on coronary CT angiography of proximal, middle, and distal coronary artery segments, using 320-row CT, and to compare two injection duration protocols as to amount of contrast in the right heart chambers. Methods: This retrospective study was approved by the local ethics committee, and the requirement for informed consent to participate in this study was waived. The final study group included 108 patients who underwent coronary CT angiography. The first 36 patients received contrast medium without saline flush (group 1); the next 36 patients received contrast medium for 14 s and saline flush (group 2); the last 36 patients received contrast medium for 12 s and saline flush (group 3). The CT number, noise, contrast-to-noise ratio (CNR), and number of segments with a CT number greater than 325 Hounsfield units (HU) were recorded for proximal, middle, and distal segments. Results: The CT numbers and the CNR in groups 2 and 3 were significantly higher than that in group 1 (p < 0.005); the difference between groups 2 and 3 was not significant. The proportion of segments greater than 325 HU improved with saline flush (p < 0.05), with a larger improvement in the distal segments. Conclusions: Saline flush improves enhancement and CNR of coronary arteries, particularly of distal segments, in coronary CT angiography using 320-row CT. An average contrast medium injection of 44 mL was feasible using a saline flush

  7. Prevalence and configuration of pulmonary nodules on multi-row CT in children without malignant diseases

    To assess the prevalence and morphologic characterization of pulmonary nodules in children on a chest computed tomography (CT). Two hundred and fifty-nine trauma chest CTs in children aged 0-18 years were retrospectively reviewed by two radiologists, each with more than 10 years of experience. Images were acquired on a 64-row CT. Pulmonary lobes with trauma affections such as contusion or haemorrhage were excluded. All pulmonary nodules were evaluated for distance from the pleural surface, location, calcification and size on axial slices. A total of 1,190/1,295 (92 %) pulmonary lobes without traumatic injury were included in this study. In 86 of 259 (33 %) patients, 131 pulmonary nodules were detected. Number of nodules per patient ranged from 1 to 4. Calcifications were seen in 19 % (25) of all nodules. Diameters ranged from 1 to 5 mm. 59 % (77) were located in the lower lobes, 9 % (12) in the middle lobe and 32 % (42) in the upper lobes. 84 % of the non-calcified nodules >2 mm showed a slightly angular or triangular (mostly pleural nodes) shape. Pulmonary nodules smaller than 5 mm can be detected frequently in children without malignant disease and are predominantly located in the lower lobes. (orig.)

  8. Prevalence and configuration of pulmonary nodules on multi-row CT in children without malignant diseases

    Renne, Julius; Wacker, Frank; Berthold, Lars-Daniel; Weidemann, Juergen [Hannover Medical School, Institute for Diagnostic and Interventional Radiology, Hannover (Germany); Linderkamp, Christin [Hannover Medical School, Pediatric Oncology, Hannover (Germany)

    2015-09-15

    To assess the prevalence and morphologic characterization of pulmonary nodules in children on a chest computed tomography (CT). Two hundred and fifty-nine trauma chest CTs in children aged 0-18 years were retrospectively reviewed by two radiologists, each with more than 10 years of experience. Images were acquired on a 64-row CT. Pulmonary lobes with trauma affections such as contusion or haemorrhage were excluded. All pulmonary nodules were evaluated for distance from the pleural surface, location, calcification and size on axial slices. A total of 1,190/1,295 (92 %) pulmonary lobes without traumatic injury were included in this study. In 86 of 259 (33 %) patients, 131 pulmonary nodules were detected. Number of nodules per patient ranged from 1 to 4. Calcifications were seen in 19 % (25) of all nodules. Diameters ranged from 1 to 5 mm. 59 % (77) were located in the lower lobes, 9 % (12) in the middle lobe and 32 % (42) in the upper lobes. 84 % of the non-calcified nodules >2 mm showed a slightly angular or triangular (mostly pleural nodes) shape. Pulmonary nodules smaller than 5 mm can be detected frequently in children without malignant disease and are predominantly located in the lower lobes. (orig.)

  9. Radiation Dose and Image Quality from Coronary Angiography in 320-Detecor Row CT

    Introduction: Coronary Computed Tomography Angiography examinations are increasing rapidly. New Computed Tomography has been developed to improve image quality with the patient dose reduction. The purpose of this study is to evaluate radiation dose and image quality of Coronary Computed Tomography Angiography in patients using 320-detector row CT. Methods: Forty-one patients referred for cardiac CT examinations at King Chulalongkorn Memorial Hospital were included in this study. All coronary computed tomographic angiography (CCTA) examinations were performed on the 320-detector row CT, Toshiba Aquilion One. Scanning protocol was investigated on dose estimates and image quality. Patients were scanned base on heart rate (HR) by HR75 bpm use retrospective with dose modulation. Scanning parameters, kVp, mAs, HR, BMI, CTDIvol(mGy) and DLP(mGy.cm), were recorded to study the factors affecting the image quality and patient dose. And mA and kVp setting depend on BMI of the patient. Effective dose is calculated from DLP using specific conversion factor. The image quality was evaluated in 4 vessels by two radiologists. Noise assessment was also studied quantitatively. Results: The patient effective dose in prospective gating 70-80% was 3.6 ± 0.9 mSv, prospective gating 30-80% (1R-R) was 6.3 ± 1.9 mSv, and 30-80% (2R-R) was 10.8 ± 1.8 mSv and in retrospective with tube current modulation was 12.1± 7.7 mSv. Image noise was highest in PGT 70-80% 1R-R and decreased in RGT with tube current modulation, PGT 30-80% 1R-R and lowest in PGT 30-80% 2 R-R. And overall qualitative image quality was mostly good to excellent score. Discussion: The heart rate, heart rate variability and disease of the patient are affecting in the radiation dose and image quality so the suitable acquisition protocol used could be necessary. the effective dose and the image noise for the image quality. (author)

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

    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

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

    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.

  12. Detection and evaluation of intracranial aneurysms with 16-row multislice CT angiography

    AIM: The aim of this study was to assess the usefulness of 16-row multislice CT angiography (CTA) in evaluating intracranial aneurysms, by comparison with conventional digital subtraction angiography (DSA) and intraoperative findings. METHODS: A consecutive series of 57 patients, scheduled for DSA for suspected intracranial aneurysm, was prospectively recruited to have CTA. This was performed with a 16-detector row machine, detector interval 0.75 mm, 0.5 rotation/s, table speed 10 mm/rotation and reconstruction interval 0.40 mm. CTA studies were independently and randomly assessed by two neuroradiologists and a vascular neurosurgeon blinded to the DSA and surgical findings. Review of CTA was performed on workstations with an interactive 3D volume-rendered algorithm. RESULTS: DSA or intraoperative findings or both confirmed 53 aneurysms in 44 patients. For both independent readers, sensitivity and specificity per aneurysm of DSA were 96.2% and 100%, respectively. Sensitivity and specificity of CTA were also 96.2% and 100%, respectively. Mean diameter of aneurysms was 6.3 mm (range 1.9 to 28.1 mm, SD 5.2 mm). For aneurysms of less than 3 mm, CTA had a sensitivity of 91.7% for each reader. Although the neurosurgeon would have been happy to proceed to surgery on the basis of CTA alone in all cases, he judged that DSA might have provided helpful additional anatomical information in 5 patients. CONCLUSION: The diagnostic accuracy of 16-slice CTA is promising and appears equivalent to that of DSA for detection and evaluation of intracranial aneurysms. A strategy of using CTA as the primary imaging method, with DSA reserved for cases of uncertainty, appears to be practical and safe

  13. Evaluation of visibility of lumen of coronary stents by CT coronary angiography using multi-detector row CT in our hospital

    Many experiments of evaluation of coronary stents by CT coronary angiography (CTCA) using multi-detector row computed tomography (MDCT) are reported since the appearance of 16-row and 64-row CT. However, blooming artifact makes the assessment of lumen of coronary stent (LCS) difficult at present. The purpose of this study is to investigate the evaluation of visibility of LCS by CTCA. CTCA was performed in 25 patients who had previously undergone stent implantation scanned using 64-row CT, and images of 32 stents were obtained. All images were classified into 4 grades (4: excellent, 3: good, 2: fair, 1: poor) according to their visibility of LCS. We investigated the correlation of stent characteristics and backgrounds (diameter, material and thickness of strut, the period from stent implantation to CTCA, the location of stent, and whether calcification or not) with the grade of visibility. We found the conditions of good visibility of LCS were the diameter >3.5 mm (ratio of ≥grade 3 was 77.8%=14/18 stents), thin strut (<100 μm), and no calcification (ratio of ≥grade 3 was 87.5%=14/16 stents). We expected that CTCA using MDCT will be established useful examination of evaluation of LCS in future. (author)

  14. An unusual combination of myocardial bridging and coronary artery aneurysm identified on 64-detector coronary angiography.

    Meraj, Perwaiz M; Makaryus, Amgad N; Boxt, Lawrence M

    2007-10-01

    Coronary artery aneurysm is an uncommon finding. It is defined as a dilated coronary artery which exceeds the diameter of the normal adjacent vessel by 1.5-2 times. Although theorized mechanisms include atherosclerotic coronary artery disease (CAD) and iatrogenic causes such as the use of percutaneous coronary interventions (PCI), the natural history and prognosis of this disease remain obscure. We describe a case of a 75 year old man who was found to have a long segmental myocardial bridge immediately followed by a 5 mm inner diameter aneurysm in the left anterior descending artery (LAD) detected on 64-detector cardiac computed tomography (64-CT). The post myocardial bridge aneurysmal dilatation in this case is unique, and has not been previously described. With the advent of 64-CT, more incidental cardiac anomalies and irregularities are likely to be found. In the end, the question as to the clinical significance of these findings and their treatment remains controversial. We report this novel case and review the literature for recommendations on treatment and management of patients with coronary aneurysms. PMID:17043905

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

    Ma Ensen [Department of Radiology, West China Hospital, Sichuan University, 37 Guo Xue Xiang, Chengdu, Sichuan 610041 (China); Yang Zhigang [Department of Radiology, West China Hospital, Sichuan University, 37 Guo Xue Xiang, Chengdu, Sichuan 610041 (China) and National Key Laboratory of Biotherapy Center, West China Hospital, Sichuan University, 37 Guo Xue Xiang, Chengdu, Sichuan 610041 (China)]. E-mail: zgyang1117@yahoo.com.cn; Li Yuan [Department of Radiology, West China Hospital, Sichuan University, 37 Guo Xue Xiang, Chengdu, Sichuan 610041 (China); Guo Yingkun [Department of Radiology, West China Hospital, Sichuan University, 37 Guo Xue Xiang, Chengdu, Sichuan 610041 (China); Deng Yuping [Department of Radiology, West China Hospital, Sichuan University, 37 Guo Xue Xiang, Chengdu, Sichuan 610041 (China); Zhang Xiaochun [Department of Radiology, West China Hospital, Sichuan University, 37 Guo Xue Xiang, Chengdu, Sichuan 610041 (China)

    2007-06-15

    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 {delta}CT 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.

  16. Multidetector-row spiral CT for detection of coronary artery stenosis

    Objective: To evaluate the feasibility and accuracy of multidetector-row spiral CT (MDCT) in the detection of coronary artery stenosis. Methods: Sixty-five consecutive patients with suspected coronary artery disease (CAD) underwent the retrospectively ECG-gated MDCT angiography for visualization of coronary artery lumen changes, and 32 of them were also investigated with selective coronary angiography (SCA). The images quality of MDCTA was analyzed. Presence and percentage of stenosis in coronary artery segments were determined. Results of determination of >50% stenosis of the vessel diameter with MDCTA were compared to the findings of SCA. Results: With MDCT angiography significant better image quality was achieved in patients with a heart rate below 70 beats per minute (W = 539, P50% stenosis with MDCTA were 95%, 80%, 89% and 90%, respectively. Conclusion: Even if its effective exposure time of 250 ms is limited by faster heart rates, MDCT is capable of achieving high image quality and high accuracy for detection of coronary artery stenosis

  17. ECG-gated multi-detector row CT for assessment of mitral valve disease: initial experience

    Our objective was to evaluate applicability and image quality of contrast-enhanced, retrospectively ECG-gated multi-detector row CT (MDCT) for visualization of anatomical details of the mitral valve and its apparatus, and to determine the value of MDCT for diagnosing abnormal findings of the mitral valve. Twenty consecutive patients with mitral valve disease underwent MDCT preoperatively. Two readers assessed visibility of the mitral valve annulus, mitral valve leaflets, tendinous cords, and papillary muscles by using a four-point Likert grading scale. Abnormal mitral valve findings [thickening of the mitral valve leaflets, presence of mitral annulus calcification (MAC), and calcification of the valvular leaflets] were compared with preoperative echocardiography and intraoperative findings. Visibility of the mitral valve annulus and mitral valve leaflets was good or excellent in 15 patients (75%) and in 19 patients (95%) for papillary muscles. The MDCT yielded a 95-100% agreement compared with echocardiography and surgery with regard to the assessment of mitral valve leaflet thickening and the presence of calcifications of the mitral valve annulus or mitral valve leaflets. Intermodality agreement between MDCT and echocardiography was excellent with regard to classification of mitral valve leaflet thickness (κ=1.00) and good regarding classification of MAC thickness (κ=0.73). Contrast-enhanced, retrospectively ECG-gated MDCT allows good to excellent visualization of anatomical details of the mitral valve and its apparatus, and demonstrates good agreement with echocardiography and surgery in diagnosing mitral valve abnormalities. (orig.)

  18. Optimal iodine dose for 3-dimensional multidetector-row CT angiography of the liver

    Purpose: To clarify the optimal iodine dose of contrast material for 3-dimensional multidetector-row CT angiography (3D-MDCTA) of the venous vasculature of the liver using volume rendering technique. Materials and methods: This study included 103 patients who were randomly assigned to 5 contrast-enhanced MDCT protocol groups with different body-weight-tailored doses of contrast material: 500, 600, 630, 650, and 700 mgI/kg body weight. The arterial, portal, and hepatic parenchymal phases were obtained to evaluate enhancement values of the aorta, portal vein, and hepatic vein. Visualization of the portal and hepatic veins on the volume-rendering images of 3D-MDCTA was evaluated using a 5-point grade. Dunnett's test was used to compare the mean enhancement value and mean grades of image quality (700 mgI/kg dose group was control). Results: The mean enhancement values of portal and hepatic vein in the group with 500 and 600 mgI/kg were significantly lower than those of the control group. During visual assessment, a significantly lower mean grades were observed in 500 mgI/kg groups for the portal vein, and 500 and 600 mgI/kg groups for hepatic vein. There were no significant intergroup differences in mean enhancement values and visual assessment among the groups using 630 mgI/kg or more. Conclusion: Iodine doses of 630 mgI/kg was recommended for 3D-MDCTA

  19. Computer-Assisted Detection of Pulmonary Nodules: Preliminary Observations Using a Prototype System with Multidetector-Row CT Data Sets

    Lawler, Leo P.; Wood, Susan A.; Pannu, Harpreet S.; Fishman, Elliot K.

    2003-01-01

    The continued revolution in multidetector-row CT (MDCT) scanning increases the quality of lung imaging but at the cost of a greater burden of data for review and interpretation. This article discusses our preliminary experience with prototype software for lung nodule detection and characterization using MDCT data sets. We discuss the potential role of computer-assisted detection (CAD) as applied to the automatic detection of lung nodules. We also review the process of CAD, outline its potenti...

  20. Detection of hepatocelluar carcinoma on triple-phase images of liver using multi-detector row helical CT

    To determine whether triple-phase multi-detector-row helical CT images of liver improves the detection rate of hepatocellular carcinoma (HCC). Forty-one patients with 103 HCCs underwent triple-detector-row helical CT imaging of the entire liver after contrast administration. Early and late arterial phase images were obtained serially during a single breath-hold, and portal venous-phase images were then obtained. Each image set was independently assessed for the presence of HCC by two radiologists unaware of the possible presence of tumors, and for each phase the detection rate was determined. For each arterial-phase image, lesion conspicuity (attenuation of a tumor compared with that of its parenchyma) was calculated. For reader 1, the detection rates for the early arterial, late arterial, and portal venous phase were 81%, 77%, and 55%, respectively, and for reader 2 were 83%, 81% and 68%, respectively (p>0.05). When triple-phase imaging findings were combined, the detection rate was significantly higher than when only those of the early or late arterial, and portal venous, phase were used (p0.05). Triple-phase imaging of the liver, involving the early arterial, late arterial, and portal venous phase, and using multi-detector-row helical CT, increases the detection rate of HCC

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

    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)

  2. Non-invasive 16-row multislice CT coronary angiography: usefulness of saline chaser

    The aim of this study was to investigate the usefulness of saline chaser in 16-row multislice CT (16-MSCT) coronary angiography. Forty-two patients were divided into two groups for contrast material (CM) administration: group 1 (140 ml at 4 ml/s) and group 2 (100 ml at 4 ml/s followed by 40 ml of saline chaser at 4 ml/s). All patients underwent retrospectively ECG-gated 16-MSCT coronary angiography. The attenuation at the origin coronary vessels was assessed. Three regions of interest (ROIs) were drawn throughout the data set: (a) ascending aorta (ROI 1); (b) descending aorta (ROI 2); and (c) pulmonary artery (ROI 3). The attenuation in the superior vena cava was recorded (ROI 4). The average attenuation and the slope were calculated in each ROI and differences were assessed with a Student's t test. The average attenuation in the coronary vessels was not significantly different in the two groups. The average attenuations in ROI 1 were 325 and 327 HU, in ROI 2 were 328 and 329 HU and in ROI 3 were 357 and 320 HU, for groups 1 and 2, respectively (p>0.05). The slopes in ROI 1 were -0.2 and 1.1, in ROI 2 were 2.8 and 2.1 (p>0.05) and in ROI3 were 3.9 and -9.0 (p<0.05), for groups 1 and 2, respectively. The average attenuations in ROI 4 were 927 and 643 HU (p<0.05), for groups 1 and 2, respectively. One hundred milliliters of CM with 40 ml of saline chaser provides the same attenuation as 140 ml of CM (35% less) with decreased hyper-attenuation in the superior vena cava. (orig.)

  3. Vulnerable plaque: Detection of agreement between multi-detector-row CT angiography and US-ECD

    Objectives: The purpose of this work was to evaluate the agreement between ultra-sound echo-color Doppler (US-ECD) and multi-detector-row CT angiography (MDCTA) in the characterization of vulnerable plaque. Methods: From January 2004 to January 2007 658 patients who underwent both MDCTA and US-ECD for the study of carotid arteries, were retrospectively evaluated (453 males, 205 females). For all subjects the following parameters were analysed: plaque morphology (regular versus irregular), type of the plaque (fatty, mixed and calcified) and presence of ulcerations. Statistical analysis was performed to calculate concordance between the two techniques employed. Results: In the definition of the type of plaque, the observed agreements were 77.2% and the kappa value was 0.657 (95% confidence interval: 0.615-0.699). The weighted kappa resulted 0.644. In the definition of ulceration plaque, the observed agreements were 88.4% but the kappa value was only 0.325 (95% confidence interval: 0.201-0.449). Agreement observed in the evaluation of plaque morphology was 78.3% with a kappa value of 0.513 (95% confidence interval: 0.452-0.574). Conclusion: We observed a good agreement between US-ECD and MDCTA in the assessment of plaque type whereas a poor agreement resulted in the evaluation of plaque ulceration. The use of US-ECD and MDCTA provides different results in the evaluation of plaque. Our results suggest that information deriving from US-ECD should be always critically compared with other diagnostic techniques.

  4. Vulnerable plaque: Detection of agreement between multi-detector-row CT angiography and US-ECD

    Saba, Luca, E-mail: lucasaba@tiscali.it [Department of Radiology Azienda Ospedaliera del Policlinico Universitario, University of Cagliari, s.s. 554 Monserrato (Cagliari) 09045 (Italy); Sanfilippo, Roberto; Montisci, Roberto [Department of Vascular Surgery, Policlinico Universitario, s.s. 554 Monserrato (Cagliari) 09045 (Italy); Atzeni, Matteo; Ribuffo, Diego [Section of Plastic Surgery, Department of Surgery, Policlinico Universitario, s.s. 554 Monserrato (Cagliari) 09045 (Italy); Mallarini, Giorgio [Department of Radiology Azienda Ospedaliera del Policlinico Universitario, University of Cagliari, s.s. 554 Monserrato (Cagliari) 09045 (Italy)

    2011-03-15

    Objectives: The purpose of this work was to evaluate the agreement between ultra-sound echo-color Doppler (US-ECD) and multi-detector-row CT angiography (MDCTA) in the characterization of vulnerable plaque. Methods: From January 2004 to January 2007 658 patients who underwent both MDCTA and US-ECD for the study of carotid arteries, were retrospectively evaluated (453 males, 205 females). For all subjects the following parameters were analysed: plaque morphology (regular versus irregular), type of the plaque (fatty, mixed and calcified) and presence of ulcerations. Statistical analysis was performed to calculate concordance between the two techniques employed. Results: In the definition of the type of plaque, the observed agreements were 77.2% and the kappa value was 0.657 (95% confidence interval: 0.615-0.699). The weighted kappa resulted 0.644. In the definition of ulceration plaque, the observed agreements were 88.4% but the kappa value was only 0.325 (95% confidence interval: 0.201-0.449). Agreement observed in the evaluation of plaque morphology was 78.3% with a kappa value of 0.513 (95% confidence interval: 0.452-0.574). Conclusion: We observed a good agreement between US-ECD and MDCTA in the assessment of plaque type whereas a poor agreement resulted in the evaluation of plaque ulceration. The use of US-ECD and MDCTA provides different results in the evaluation of plaque. Our results suggest that information deriving from US-ECD should be always critically compared with other diagnostic techniques.

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

    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

  6. Intravenous three-dimensional CT portography using multi-detector row CT in patients with hepatic cirrhosis. Evaluation of scan timing and image quality

    The purpose of this study was to evaluate the scan timing and image quality of intravenous three-dimensional (3D) CT portography using multi-detector row CT (MDCT) and to assess the influence of patients' body weight on enhancement of the portal vein (PV). One hundred nine patients with hepatic cirrhosis underwent triple-phase contrast enhanced CT using MDCT. The early, portal, and late phases were started at 30 sec, 60 sec, and 90 sec, respectively, after the beginning of intravenous injection of contrast medium (300 mgI/mL, 100 mL total). The CT value of the PV was assessed in the three phases: precontrast, portal phase, and late phase. 3D-portography of the MIP image was evaluated by three-point scale based on vessel visualization. The relationship between these data and body weight was investigated. The mean CT value of PV at 60 sec was 172.01±25.94 HU, which was significantly higher than that at 90 sec. Good or excellent 3D-CT portography was obtained in 97/109 patients (89%). Heavy patients tended to show less opacification of PV. Intravenous 3D-CT portography using MDCT at a 60 sec delay provided adequate PV images for patients with hepatic cirrhosis. Enhancement of PV was affected by patients' body weight. (author)

  7. Whole-brain 320-detector row dynamic volume CT perfusion detected crossed cerebellar diaschisis after spontaneous intracerebral hemorrhage

    The purpose of this study was to evaluate the value of 320-detector row CT used to detect crossed cerebellar diaschisis (CCD) in patients with unilateral supratentorial spontaneous intracerebral hemorrhage (SICH). We investigated 62 of 156 patients with unilateral supratentorial SICH using 320-detector row CT scanning. Regional cerebral blood flow (rCBF), cerebral blood volume (rCBV), mean transit time (rMTT), and time to peak (rTTP) levels were measured in different regions of interest (ROIs) that were manually outlined on computed tomography perfusion (CTP) for the cerebrum, including normal-appearing brain tissue that surrounded the perilesional low-density area (NA) and the perihematomal low-density area (PA) in all patients and the cerebellum (ipsilateral and contralateral) in CCD-positive patients. Of 62 cases, a total of 14 met the criteria for CCD due to cerebellar perfusion asymmetry on CTP maps. In the quantitative analysis, significant differences were found in the perfusion parameters between the contralateral and ipsilateral cerebellum in CCD-positive cases. No significant differences were found between the CCD-positive group and the CCD-negative group according to the hematoma volume, NIHSS scores, and cerebral perfusion abnormality (each P > 0.05). The correlation analysis of the degree of NA, PA perfusion abnormality, and the degree of CCD severity showed negative and significant linear correlations (R, -0.66∝-0.56; P < 0.05). 320-detector row CT is a robust and practicable method for the comprehensive primary imaging work-up of CCD in unilateral supratentorial SICH patients. (orig.)

  8. Whole-brain 320-detector row dynamic volume CT perfusion detected crossed cerebellar diaschisis after spontaneous intracerebral hemorrhage

    Fu, Jun; Chen, Wei-jian; Wang, Mei-hao; Li, Jian-ce; Zhang, Qian; Xia, Neng-zhi; Yang, Yun-jun [Wenzhou Medical University, Department of Radiology, First Affiliated Hospital, Wenzhou (China); Wu, Gui-yun [Cleveland Clinics Foundation, Department of Nuclear Medicine, Imaging Institute, Cleveland, OH (United States); Cheng, Jing-liang; Zhang, Yong [Zhengzhou University, Department of Radiology, First Affiliated Hospital, Zhengzhou (China); Zhuge, Qichuan [Wenzhou Medical University, Department of Neurosurgery, First Affiliated Hospital, Wenzhou (China)

    2014-11-09

    The purpose of this study was to evaluate the value of 320-detector row CT used to detect crossed cerebellar diaschisis (CCD) in patients with unilateral supratentorial spontaneous intracerebral hemorrhage (SICH). We investigated 62 of 156 patients with unilateral supratentorial SICH using 320-detector row CT scanning. Regional cerebral blood flow (rCBF), cerebral blood volume (rCBV), mean transit time (rMTT), and time to peak (rTTP) levels were measured in different regions of interest (ROIs) that were manually outlined on computed tomography perfusion (CTP) for the cerebrum, including normal-appearing brain tissue that surrounded the perilesional low-density area (NA) and the perihematomal low-density area (PA) in all patients and the cerebellum (ipsilateral and contralateral) in CCD-positive patients. Of 62 cases, a total of 14 met the criteria for CCD due to cerebellar perfusion asymmetry on CTP maps. In the quantitative analysis, significant differences were found in the perfusion parameters between the contralateral and ipsilateral cerebellum in CCD-positive cases. No significant differences were found between the CCD-positive group and the CCD-negative group according to the hematoma volume, NIHSS scores, and cerebral perfusion abnormality (each P > 0.05). The correlation analysis of the degree of NA, PA perfusion abnormality, and the degree of CCD severity showed negative and significant linear correlations (R, -0.66∝-0.56; P < 0.05). 320-detector row CT is a robust and practicable method for the comprehensive primary imaging work-up of CCD in unilateral supratentorial SICH patients. (orig.)

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

    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)

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

    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

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

    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.

  12. Volumetric Measurements of Lung Nodules with Multi-Detector Row CT: Effect of Changes in Lung Volume

    To evaluate how changes in lung volume affect volumetric measurements of lung nodules using a multi-detector row CT. Ten subjects with asthma or chronic bronchitis who had one or more lung nodules were included. For each subject, two sets of CT images were obtained at inspiration and at expiration. A total of 33 nodules (23 nodules ≥3 mm) were identified and their volume measured using a semiautomatic volume measurement program. Differences between nodule volume on inspiration and expiration were compared using the paired t-test. Percent differences, between on inspiration and expiration, in nodule attenuation, total lung volume, whole lung attenuation, and regional lung attenuation, were computed and compared with percent difference in nodule volume determined by linear correlation analysis. The difference in nodule volume observed between inspiration and expiration was significant (p < 0.01); the mean percent difference in lung nodule volume was 23.1% for all nodules and for nodules ≥3 mm. The volume of nodules was measured to be larger on expiration CT than on inspiration CT (28 out of 33 nodules; 19 out of 23 nodules ≥3 mm). A statistically significant correlation was found between the percent difference of lung nodule volume and lung volume or regional lung attenuation (p < 0.05) for nodules ≥3 mm. Volumetric measurements of pulmonary nodules were significantly affected by changes in lung volume. The variability in this respiration-related measurement should be considered to determine whether growth has occurred in a lung nodule

  13. Cardiac multidetector row CT before percutaneous coronary intervention as a treatment guide for chronic total occlusion cardiac multidetector row CT before percutaneous coronary intervention as a treatment guide for chronic total occlusion

    The goal of this study was to investigate imaging results from a coronary CT angiography (CCTA) in chronic coronary total occlusion (CTO) before percutaneous coronary intervention (PCI). In 74 patients with CTO, 34 patients was evaluated by using a 64-row multidetector CT scanner prior to the PCI and 40 control subjects with CTO, who only took PCI, were included. The multiplanar reformation of the heart chambers and three-dimensional CT images were used for determining an optimal view. We analyzed and evaluated the success rates of PCI, length of occluded vessel, calcified plaques, occluded side-branches, tapered occlusion, > 45 degrees angulation of occluded artery, and myocardial density < 50 Hounsfield unit (HU). Success rates of PCI in the two groups, the control group and the experimental group, were not statistically different (p > 0.05). The mean length of occluded arteries was measured as 25 +/- 11 mm and 26 cases (74%) had an occlusion length > 2 cm. Calcified plaques proximal to occlusion were detected in 19 cases (54%). Occluded side branches, tapered occlusion, > 45 degrees angulation of occluded artery, and myocardial density < 50 HU were in 11 cases (32%), 9 cases (27%), 6 cases (18%), and 5 cases (15%), respectively. Although there was no correlation between the CCTA findings before PCI and the success rate of PCI, common findings of CCTA in CTO included an occlusion length > 2 cm and calcified plaques proximal to occluded arteries.

  14. Cardiac multidetector row CT before percutaneous coronary intervention as a treatment guide for chronic total occlusion cardiac multidetector row CT before percutaneous coronary intervention as a treatment guide for chronic total occlusion

    Kim, Dong Hun; Choi, Dong Hyun [Dept. of Radiology, Chosun University Hospital, Gwangju (Korea, Republic of); Lee, Nae Hee [Dept. of Internal Medicine, Soonchunhyang University Bucheon Hospital, Bucheon (Korea, Republic of)

    2015-03-15

    The goal of this study was to investigate imaging results from a coronary CT angiography (CCTA) in chronic coronary total occlusion (CTO) before percutaneous coronary intervention (PCI). In 74 patients with CTO, 34 patients was evaluated by using a 64-row multidetector CT scanner prior to the PCI and 40 control subjects with CTO, who only took PCI, were included. The multiplanar reformation of the heart chambers and three-dimensional CT images were used for determining an optimal view. We analyzed and evaluated the success rates of PCI, length of occluded vessel, calcified plaques, occluded side-branches, tapered occlusion, > 45 degrees angulation of occluded artery, and myocardial density < 50 Hounsfield unit (HU). Success rates of PCI in the two groups, the control group and the experimental group, were not statistically different (p > 0.05). The mean length of occluded arteries was measured as 25 +/- 11 mm and 26 cases (74%) had an occlusion length > 2 cm. Calcified plaques proximal to occlusion were detected in 19 cases (54%). Occluded side branches, tapered occlusion, > 45 degrees angulation of occluded artery, and myocardial density < 50 HU were in 11 cases (32%), 9 cases (27%), 6 cases (18%), and 5 cases (15%), respectively. Although there was no correlation between the CCTA findings before PCI and the success rate of PCI, common findings of CCTA in CTO included an occlusion length > 2 cm and calcified plaques proximal to occluded arteries.

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

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

    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

  17. Multidetector-Row CT Angiography of Cerebral Vasospasm after Aneurysmal Subarachnoid Hemorrhage: Comparison of Bone Subtraction and Standard CT Angiography with Digital Subtraction Angiography

    Lee, Yong Hee; You, Jin Jong; Choi, Ho Cheol; Kim, Ji Eun [Dept. of Radiology, Gyeongsang National University Hospital, Jinju (Korea, Republic of); Choi, Dae Seob [Gyeongsang Institue of Health Science, Gyeongsang National University School of Medicine, Jinju (Korea, Republic of); Ryoo, Jae Wook [Dept. of Radiology, Samsung Seoul Hospital, Seoul (Korea, Republic of)

    2011-10-15

    To evaluate the usefulness of multidetector-row CT angiography (MDCTA) for the diagnosis of cerebral vasospasm after aneurysmal subarachnoid hemorrhage (SAH) by comparison of digital subtraction angiography (DSA) and to compare the bone subtraction CT angiography (BS-CTA) and standard CT angiography (S-CTA). Thirty-three patients who were treated with intraarterial nimodipine infusion for the cerebral vasospasm after aneurysmal SAH were evaluated with MDCTA and DSA. BS-CTA images were reconstructed from the S-CTA and unenhanced CT source images. A total of 207 vascular segments were evaluated. A four-step scale for the degree of stenosis was applied for each segment. With DSA as the standard images, BS-CTA and S-CTA images were comparied. On DSA, 56 segments (27%) presented vasospasm. Concordance between the DSA and S-CTA and between DSA and BS-CTA were 94.7% and 82.1%, respectively. Overestimation for the degree of stenosis was shown in 37 segments on BS-CTA and in 8 segments on S-CTA, but underestimated segments were only shown on S-CTA (n = 4). MDCTA with standard technique seems to be a useful imaging tool for the evaluation of the cerebral vasospasm after aneurysmal SAH. However, BS-CTA is not needed because of additional radiation and overestimation of the degree of stenosis.

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

    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

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

    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.

  20. Characteristics of artifacts in two kinds of multi detector-row CT. An examination of the angle dependence for a slice plane

    We examined using the phantom whether there would be the tendency of artifact generated by Multi Detector-row CT (MD-CT) and the angle dependence between artifact and the structure to a slice side. In addition whether it is artifact peculiar to MD-CT with use of Single Detector-row CT. Even if images are obtained by pith-up, to set the thin collimation is one of the methods reduce artifact. When we take clinical usefulness into consideration the images cannot be obtain by sufficient S/N ratio, duration of respiratory suspension and more thin-section. It is necessary to carry out further experiment and examinations obtain images into consideration. (author)

  1. A pictorial review of acute aortic syndrome: discriminating and overlapping features as revealed by ECG-gated multidetector-row CT angiography

    Ueda, Takuya; Chin, Anne; Petrovitch, Ivan; Fleischmann, Dominik

    2012-01-01

    Background The term "acute aortic syndrome" (AAS) encompasses a spectrum of life-threatening conditions characterized by acute aortic pain. AAS traditionally embraces three abnormalities including classic aortic dissection, intramural haematoma, and penetrating atherosclerotic ulcer. Although the underlying etiologies and conditions predisposing to AAS are diverse, the clinical features are indistinguishable. Methods Multidetector-row computed tomography (CT) with electrocardiographic gating ...

  2. Physical evaluation of CT scan methods for radiation therapy planning: comparison of fast, slow and gating scan using the 256-detector row CT scanner

    Mori, Shinichiro [Department of Medical Physics, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba (Japan); Kanematsu, Nobuyuki [Department of Medical Physics, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba (Japan); Mizuno, Hideyuki [Department of Medical Physics, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba (Japan); Sunaoka, Masayoshi [Hospital, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba (Japan); Endo, Masahiro [Department of Medical Physics, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba (Japan)

    2006-02-07

    Although slow-rotation CT scanning (slow-scan CT: SSCT) has been used for radiation therapy planning, based on the rationale that the average duration of the human respiratory cycle is 4 s, a number of physical and quantitative questions require answering before it can be adopted for clinical use. This study was performed to evaluate SSCT physically in comparison with other scan methods, including respiratory-gated CT (RGCT), and to develop procedures to improve treatment accuracy. Evaluation items were geometrical accuracy, volume accuracy, water equivalent length and dose distribution using the 256-detector row CT with three scan methods. Fast-scan CT (FSCT) was defined as obtaining all respiratory phases in cine scan mode at 1.0 s per rotation. FSCT-ave was the averaged FSCT images in all respiratory phases, obtained by reconstructing short time intervals. SSCT has been defined as scanning with slow gantry rotation to capture the whole respiratory cycle in one rotation. RGCT was scanned at the most stable point in the respiratory cycle, which provides the same image as that by FSCT at the most stable point. Results showed that all evaluation items were dependent on motion characteristics. The findings of this study indicate that 3D planning based solely on SSCT under free breathing may result in underdosing of the target volume and increase toxicity to surrounding normal tissues. Of the three methods, RGCT showed the best ability to significantly increase the accuracy of dose distribution, and provided more information to minimize the margins. FSCT-ave is a satisfactory radiotherapy planning alternative if RGCT is not available.

  3. Detection, characterization and endovascular therapy planning of intracranial aneurysms with 16-channel multidetector row CT angiography

    Amr Badry

    2014-03-01

    Conclusion: Sixteen channel Multidetector CT angiography offers high diagnostic accuracy nearly equivalent to that of DSA in the detection of intracranial aneurysms. However, 16 channel- MDCTA still has limited sensitivity in detecting aneurysms of 3 mm or less, despite its technical advances. MDCT can be used as a reliable alternative imaging technique to DSA in selected cases.

  4. Diagnostic Performance of Transluminal Attenuation Gradient and Noninvasive Fractional Flow Reserve Derived from 320-Detector Row CT Angiography to Diagnose Hemodynamically Significant Coronary Stenosis: An NXT Substudy.

    Ko, Brian S; Wong, Dennis T L; Nørgaard, Bjarne L; Leong, Darryl P; Cameron, James D; Gaur, Sara; Marwan, Mohamed; Achenbach, Stephan; Kuribayashi, Sachio; Kimura, Takeshi; Meredith, Ian T; Seneviratne, Sujith K

    2016-04-01

    Purpose To compare the diagnostic performance of 320-detector row computed tomography (CT) coronary angiography-derived computed fractional flow reserve (FFR; FFRCT), transluminal attenuation gradient (TAG; TAG320), and CT coronary angiography alone to diagnose hemodynamically significant stenosis as determined by invasive FFR. Materials and Methods This substudy of the prospective NXT study (no. NCT01757678) was approved by each participating institution's review board, and informed consent was obtained from all participants. Fifty-one consecutive patients who underwent 320-detector row CT coronary angiographic examination and invasive coronary angiography with FFR measurement were included. Independent core laboratories determined coronary artery disease severity by using CT coronary angiography, TAG320, FFRCT, and FFR. TAG320 is defined as the linear regression coefficient between luminal attenuation and axial distance from the coronary ostium. FFRCT was computed from CT coronary angiography data by using computational fluid dynamics technology. Diagnostic performance was evaluated and compared on a per-vessel basis by the area under the receiver operating characteristic (ROC) curve (AUC). Results Among 82 vessels, 24 lesions (29%) had ischemia by FFR (FFR ≤ 0.80). FFRCT exhibited a stronger correlation with invasive FFR compared with TAG320 (Spearman ρ, 0.78 vs 0.47, respectively). Overall per-vessel accuracy, sensitivity, specificity, and positive and negative predictive values for TAG320 (<15.37) were 78%, 58%, 86%, 64%, and 83%, respectively; and those of FFRCT were 83%, 92%, 79%, 65%, and 96%, respectively. ROC curve analysis showed a significantly larger AUC for FFRCT (0.93) compared with that for TAG320 (0.72; P = .003) and CT coronary angiography alone (0.68; P = .008). Conclusion FFRCT computed from 320-detector row CT coronary angiography provides better diagnostic performance for the diagnosis of hemodynamically significant coronary stenoses

  5. Accuracy of multidetector-row CT for restaging after neoadjuvant treatment in patients with oesophageal cancer

    Konieczny, Agnieszka; Weishaupt, Dominik [Triemli Hospital, Institute of Radiology, Zuerich (Switzerland); Meyer, Philipp; Schnider, Annelies [Triemli Hospital, Department of Visceral Surgery, Zuerich (Switzerland); Komminoth, Paul [Triemli Hospital, Institute of Pathology, Zuerich (Switzerland); Schmid, Mathias [Triemli Hospital, Clinic of Medical Oncology and Hematology, Zuerich (Switzerland); Lombriser, Norbert [Triemli Hospital, Department of Radio-Oncology, Zuerich (Switzerland)

    2013-09-15

    To assess the diagnostic accuracy of 64-multidetector CT (MDCT) for restaging of patients with oesophageal cancer undergoing neoadjuvant therapy. Results of pathological staging were correlated with those from 64-MDCT before and after neoadjuvant treatment in 35 patients using the American Joint Committee on Cancer/TNM classification (7th edition). CT response was determined using the Response Evaluation Criteria in Solid Tumours (RECIST) method, modified for one-dimensional tumour diameter measurement. 64-MDCT predicted T stage correctly in 34 % (12/35), overstaged in 49 % (17/35) and understaged in 17 % (6/35). Sensitivity/specificity values were as follows: T0, 20 %/92 %; T1-T2, 31 %/59 %; T3, 60 %/64 %; T4, 100 %/4 %. Negative predictive values for T3/T4 were 80 %/100 %. MDCT accurately predicted complete histopathological response in 20 % (accuracy 74 %) and overstaged in 80 %. Tumour regression grade was predicted correctly in only 8 % (2/25) and underestimated in 68 % (17/25). Accurate N stage was noted in 69 % (24/35). Although MDCT tends to be able to exclude advanced tumour stages (T3, T4) with a higher likelihood, the diagnostic accuracy of high resolution MDCT for restaging oesophageal cancer and assessing the response to neoadjuvant therapy has not improved in comparison to older-generation CT. Therefore, the future assessment of oesophageal tumour response should focus on combined morphologic and metabolic imaging. (orig.)

  6. The effects of misinterpretation of an artefact on multidetector row CT scans in children

    Artefacts reflect problems with radiographic technique rather than true pathology. These may be misinterpreted as pathology with serious consequences. An artefact caused such problems in one paediatric imaging department. To determine the incidence, and consequences of misinterpretation, of a CT artefact in a paediatric imaging department. A retrospective review of images and reports of paediatric CT scans over a set period with a known artefact was performed. Reports were correlated with reviewers' evaluation of the presence of artefact and reviewed for correct identification of artefact, misinterpretation as pathology, and action taken as a result. A total of 74 CT scans had been performed over the study period and an artefact detected by reviewers on 32 (43%). Six (18.75%) of these were misinterpreted as pathology, of which three (9.4%) were reported as tuberculous granulomas, two (6.2%) as haemorrhages and one (3.1%) as an unknown hyperdensity. Two patients (6.2%) had subsequent MRI studies performed, and treatment for tuberculosis was continued in one patient (3.1%). No initial report identified the artefact. One-fifth of the scans with the artefact were misinterpreted as pathology and half of these misinterpretations led to further action. Artefacts result in false diagnoses and unnecessary investigations; vigilance is needed. (orig.)

  7. Value of Virtual Colonoscopy with 64 Row CT in Evaluation of Colorectal Cancer

    Virtual colonoscopy (VC) enables three-dimensional view of walls and internal lumen of the colon as a result of reconstruction of multislice CT images. The role of VC in diagnosis of the colon abnormalities systematically increases, and in many medical centers all over the world is carried out as a screening test of patients with high risk of colorectal cancer. We analyzed results of virtual colonoscopy of 360 patients with clinical suspicion of colorectal cancer. Sensitivity and specificity of CT colonoscopy for detection of colon cancers and polyps were assessed. Results of our research have shown high diagnostic efficiency of CT colonoscopy in detection of focal lesions in large intestine of 10 mm or more diameter. Sensitivity was 85.7%, specificity 89.2%. Virtual colonoscopy is noninvasive and well tolerated by patients imaging method, which permits for early detection of the large intestine lesions with specificity and sensitivity similar to classical colonoscopy in screening exams in patients suspected for colorectal cancer. Good preparation of the patients for the examination is very important for proper diagnosis and interpretation of this imaginge procedure

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

    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.)

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

    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.)

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

    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.)

  11. Dose related, comparative evaluation of a novel bone-subtraction algorithm in 64-row cervico-cranial CT angiography

    Siebert, E.; Bohner, G. [Department of Neuroradiology, Charite Universitary Medicine Berlin (Germany); Dewey, M.; Bauknecht, C. [Department of Radiology, Charite Universitary Medicine Berlin (Germany); Klingebiel, R. [Department of Neuroradiology, Charite Universitary Medicine Berlin (Germany)], E-mail: randolf.klingebiel@charite.de

    2010-01-15

    Purpose: Comparative evaluation of a low-dose scan protocol for a novel bone-subtraction (BS) algorithm, applicable to 64-row cervico-cranial (cc) CT angiography (MSCTA). Methods and patients: BS algorithm assessment was performed in cadaveric phantom studies by stepwise variation of tube current and head malrotation using a 64-row CT scanner. In order to define minimum dose requirements and the rotation correction capacity, a low dose BS MSCTA protocol was defined and evaluated in 12 patients in comparison to a common manual bone removal algorithm. Standard MIPs of both modalities were evaluated in a blinded manner by two neuroradiologists for image quality composed, of vessel contour sharpness and bony vessel superposition, by using a five-point score each. Effective Dose (E) and data post-processing times were defined. Results: In experimental studies prescan tube current could be cut down to one-sixth of post-contrast scan doses without compromise of bone-subtraction whereas incomplete subtraction appeared from four degrees head malrotation on. Prescan E amounted to additional 1.1 mSv (+25%) in clinical studies. BS MSCTA performed significantly superior in terms of bony superposition for vascular segments C3-C7 (p < 0.001), V1-V2, V3-V4 (p < 0.05, p < 0.001 respectively) and the ophthalmic artery (p < 0.05), whereas vessel contour sharpness in BS MSCTA only proved superior for arterial segments V3-V4 (p < 0.001) and C3-C7 (p < 0.001). MBR MSCTA received higher ratings in vessel contour sharpness for C1-C2 (p < 0.001), callosomarginal artery (p < 0.001), M1, M2, M3 (p < 0.001 each) and the basilar artery (p < 0.001). Reconstruction times amounted to an average of 1.5 (BS MSCTA) and 3 min (MBR MSCTA) respectively. Conclusion: The novel BS algorithm provides superior skull base artery visualisation as compared to common manual bone removal algorithms, increasing the Effective Dose by one-fourth. Yet, inferior vessel contour sharpness was noted intracranially, thus

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

    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. Multi-detector row CT for depicting anatomic features of cephalothoracopagus varieties: revised approach.

    Grassi, Roberto; Esposito, Vincenzo; Scaglione, Mariano; Cirillo, Mario; Cappabianca, Salvatore; Guglielmi, Giuseppe; Sasso, Francesco Silvano; Rotondo, Antonio

    2004-01-01

    Conjoined twins can be classified on the basis of the site of union; thus, three main types can be described: (a) ventral union, (b) dorsal union, and (c) rarer forms of union. Ventral union is characterized by the fusion of the two embryos on the ventral side (eg, the abdomen). Dorsal union twins are joined on the dorsal aspect (eg, the vertebral column or occipital bone). Ventral union twins include the group of crucipage twins (ventral midline structures at 90 degrees to the dorsal midline structures), which show interesting features in the organization of the midline. Twins conjoined at the head and chest are called cephalothoracopagus twins. The cephalothoracopagus variety called "Janus" is characterized by the presence of two opposite faces, which are composite structures half of which belong to one twin and half to the other. A complete set of five variants of cephalothoracopagus is presented and, to the authors' knowledge, analyzed for the first time with multi-detector row helical computed tomography. This modality is an invaluable tool for obtaining high-resolution images of the brain, chest, abdomen, and spine and for demonstrating organ position, shared viscera, and limited vascular anatomy. In addition, data acquired in three-dimensional volumes can further be manipulated and then reconstructed. For this purpose, the authors developed dedicated software for three-dimensional reconstruction to analyze data from specimens preserved in formalin. The anatomic findings are discussed here for their embryologic value and to revise the classification of cephalothoracopagus twins. These data offer detailed information for accurate comprehension of imaging studies and for theoretical studies concerning the formation of several anatomic structures. PMID:15249653

  14. Are pancreatic calcifications specific for the diagnosis of chronic pancreatitis? A multidetector-row CT analysis

    Campisi, A. [Department of Radiology, University of Palermo, via del Vespro 127, 90127 Palermo (Italy); Brancatelli, G. [Department of Radiology, University of Palermo, via del Vespro 127, 90127 Palermo (Italy); Department of Radiology, University of Pittsburgh School of Medicine, 200 Lothrop street, 15213, Pittsburgh, PA (United States); Radiology Unit, La Maddalena hospital, 90146, Palermo (Italy)], E-mail: gbranca@yahoo.com; Vullierme, M.-P.; Levy, P.; Ruzniewski, P. [Universite Paris 7 Denis Diderot, Paris, F-75018 (France); AP-HP, Hopital Beaujon, Department of Radiology, Clichy F-92100 (France); Vilgrain, V. [Universite Paris 7 Denis Diderot, Paris, F-75018 (France); AP-HP, Hopital Beaujon, Department of Radiology, Clichy F-92100 (France); INSERM, U773, Centre de recherche biomedicale Bichat-Beaujon, CRB3, Paris F-75018 (France)

    2009-09-15

    Aim: To retrospectively establish the most frequently encountered diagnoses in patients with pancreatic calcifications and to investigate whether the association of certain findings could be helpful for diagnosis. Materials and methods: One hundred and three patients were included in the study. The location and distribution of calcifications; presence, nature, and enhancement pattern of pancreatic lesions; pancreatic atrophy and ductal dilatation were recorded. Differences between patients with chronic pancreatitis and patients with other entities were compared by using Fisher's exact test. Results: Patients had chronic pancreatitis (n = 70), neuroendocrine tumours (n = 14), intraductal papillary mucinous neoplasm (n = 11), pancreatic adenocarcinoma (n = 4), serous cystadenoma (n = 4). Four CT findings had a specificity of over 60% for the diagnosis of chronic pancreatitis: parenchymal calcifications, intraductal calcifications, parenchymal atrophy, and cystic lesions. When at least two of these four criteria were used in combination, 54 of 70 (77%) patients with chronic pancreatitis could be identified, but only 17 of 33 (51%) patients with other diseases. When at least three of these four criteria were present, a specificity of 79% for the diagnosis of chronic pancreatitis was achieved. Conclusion: Certain findings are noted more often in chronic pancreatitis than in other pancreatic diseases. The presence of a combination of CT findings can suggest chronic pancreatitis and be helpful in diagnosis.

  15. Are pancreatic calcifications specific for the diagnosis of chronic pancreatitis? A multidetector-row CT analysis

    Aim: To retrospectively establish the most frequently encountered diagnoses in patients with pancreatic calcifications and to investigate whether the association of certain findings could be helpful for diagnosis. Materials and methods: One hundred and three patients were included in the study. The location and distribution of calcifications; presence, nature, and enhancement pattern of pancreatic lesions; pancreatic atrophy and ductal dilatation were recorded. Differences between patients with chronic pancreatitis and patients with other entities were compared by using Fisher's exact test. Results: Patients had chronic pancreatitis (n = 70), neuroendocrine tumours (n = 14), intraductal papillary mucinous neoplasm (n = 11), pancreatic adenocarcinoma (n = 4), serous cystadenoma (n = 4). Four CT findings had a specificity of over 60% for the diagnosis of chronic pancreatitis: parenchymal calcifications, intraductal calcifications, parenchymal atrophy, and cystic lesions. When at least two of these four criteria were used in combination, 54 of 70 (77%) patients with chronic pancreatitis could be identified, but only 17 of 33 (51%) patients with other diseases. When at least three of these four criteria were present, a specificity of 79% for the diagnosis of chronic pancreatitis was achieved. Conclusion: Certain findings are noted more often in chronic pancreatitis than in other pancreatic diseases. The presence of a combination of CT findings can suggest chronic pancreatitis and be helpful in diagnosis.

  16. Prospective ECG-gated 320-row CT angiography of the whole aorta and coronary arteries

    Li, Yu.; Fan, Zhanming; Xu, Lei; Yang, Lin; Xin, Haiyan; Zhang, Nan [Capital Medical University, Department of Radiology, Beijing An Zhen Hospital, Beijing (China); Capital Medical University, Ministry of Education, The Key Laboratory of Remodeling-Related Cardiovascular Diseases, Beijing An Zhen Hospital, Beijing (China); Zhang, Zhaoqi [Capital Medical University, Department of Radiology, Beijing An Zhen Hospital, Beijing (China)

    2012-11-15

    To investigate the feasibility of using a prospective ECG-gated wide-volume protocol in CT angiography (CTA) of the whole aorta and coronary arteries (CA). A total of 61 consecutive patients with suspected acute aortic diseases underwent CTA of the whole aorta using a prospective ECG-gated wide-volume CT protocol without heart rate (HR) control. The exposure window was set at 40-50 % of R-R interval (HR {>=}70 bpm) or 70-80 % of R-R interval (HR <70 bpm) in a single heartbeat. The image quality of the ascending aorta, aortic valve and CA was evaluated for motion artefacts. The mean attenuation was measured at different levels of the aorta. The radiation dose and contrast medium volume were recorded. All of the examinations were performed successfully. The image quality was acceptable in the ascending aorta, aortic valve (100 %) and CA (94.4 %). The mean radiation dose was 18.42 {+-} 5.02 mSv. Of 61 patients, 14 were diagnosed with aortic aneurysm and 35 were diagnosed with aortic dissection or intramural haematoma. Coronary artery stenosis was detected in 12 patients. For patients with aortic diseases, CTA of the whole aorta using a prospective ECG-gated wide-volume protocol has the potential to provide additional information about the CA and aortic valve with lower radiation exposure. (orig.)

  17. Scan time and patient dose for thoracic imaging in neonates and small children using axial volumetric 320-detector row CT compared to helical 64-, 32-, and 16- detector row CT acquisitions

    Recently a 320-detector-row CT (MDCT) scanner has become available that allows axial volumetric scanning of a 16-cm-long range (50 cm field of view) in a single 0.35-s rotation. For imaging neonates and small children, volume scanning is potentially of great advantage as the entire scan range can be acquired in 0.35 s, which can reduce motion artefacts and may reduce the need for sedation in clinical CT imaging. Also, because there is no over-ranging associated with axial volumetric scanning, this may reduce patient radiation dose. To evaluate, by means of a phantom study, scan time and patient dose for thoracic imaging in neonates and small children by using axial cone-beam and helical fan-beam MDCT acquisitions. Paediatric imaging protocols were assessed for a 320-MDCT volumetric scanner (Aquilion ONE, Toshiba, Otawara, Japan). The 320-MDCT scanner allows for cone-beam acquisitions with coverage up to 160 mm, but it also allows for helical fan-beam acquisitions in 64-, 32-, or 16-MDCT modes. The acquisition configurations that were evaluated were 320 x 0.5 mm, 240 x 0.5 mm, and 160 x 0.5 mm for axial volumetric scanning, and 64 x 0.5 mm, 32 x 0.5 mm, and 16 x 0.5 mm for helical scanning. Dose assessment was performed for clinically relevant paediatric angiographic or chest/mediastinum acquisition protocols with tube voltages of 80 or 100 kVp and tube currents between 40 and 80 mA. Scan time was 0.35 s for 320-MDCT acquisitions, scan times varied between 1.9 s and 8.3 s for helical acquisitions. Dose savings varying between 18% and 40% were achieved with axial volumetric scanning as compared to helical scanning (for 320- versus 64-MDCT at 160 mm and 80 kVp, and for 320- versus 16-MDCT at 80 mm and 100 kVp, respectively). Statistically significant reduction in radiation dose was found for axial 320-MDCT volumetric scanning compared to helical 64-, 32-, and 16-MDCT scanning. Axial thoracic CT of neonates and small children with volumetric 320-MDCT can be performed

  18. Localization of bleeding using 4-row detector-CT in patients with clinical signs of acute gastrointestinal hemorrhage

    Purpose: There is no gold-standard regarding the diagnostic work-up and therapy of an acute gastrointestinal (GI) hemorrhage. In most cases endoscopy provides the diagnosis but in a low percentage this modality is not feasible or negative. Purpose of this study was to evaluate the role of multi-phase Multi-Slice-Computertomography (MSCT) as a modality to diagnose and locate the site of acute GI hemorrhage in case of unfeasible or technically difficult endoscopy. Materials and methods: 58 patients, presenting with clinical signs of lower GI hemorrhage, were examined through a 24-month period. Preliminary endoscopy was either negative or unfeasible. Images were obtained with a four-detector row CT with an arterial (4 x 1 mm collimation, 0.8 mm increment, 1.25 mm slice width, 120 kV, 165 mAs) and portal venous series (4 x 2,5 mm collimation, 2 mm increment, 3 mm slice width, 120 kV, 165 mAs). Time interval between endoscopy and CT varied between 30 minutes and 3 hours. The results of the MSCT were correlated with clinical course and surgical or endoscopical treatment. Results: 20 of the 58 patients (34%) undergoing MSCT had a bleeding site identified, thus providing decisive information for the following intervention. In case of a following therapeutic intervention there was 100% correlation regarding the bleeding site. In 38 of the 58 patients (66%), a bleeding site was not identified by MSCT. Twenty of these 38 patients (53%) were stable and required no further treatment. In 18 of these 38 patients further interventional therapy was required due to continuing hemorrhage and in all of those patients the bleeding site was detected by intervention. (orig.)

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

    Li Xiaoming, E-mail: lixiaoming55@hotmail.co [Department of Radiology, Changhai Hospital, Second Military Medical University, Shanghai 200433 (China); Department of Radiology, Xin Hua Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200092 (China); Li Yuhua, E-mail: liyuhua2000@hotmail.co [Department of Radiology, Xin Hua Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200092 (China); Tian Jianming, E-mail: tianjianming1952@hotmail.co [Department of Radiology, Changhai Hospital, Second Military Medical University, Shanghai 200433 (China); Xiao Yi, E-mail: xiaoyi@188.co [Department of Radiology, Changhai Hospital, Second Military Medical University, Shanghai 200433 (China); Lu Jianping, E-mail: lujianping2000@hotmail.co [Department of Radiology, Changhai Hospital, Second Military Medical University, Shanghai 200433 (China); Jing Zaiping, E-mail: jingzaiping@hotmail.co [Department of Vascular Surgery, Changhai Hospital, Second Military Medical University, Shanghai 200433 (China); Sheng Jing, E-mail: shengjing1997@hotmail.co [Department of Radiology, Changhai Hospital, Second Military Medical University, Shanghai 200433 (China); Edwin, Angela, E-mail: angiedwin@yahoo.co [Department of Emergency, 34 Military Hospital, Wilberforce Barracks, Republic of Sierra Leone Armed Forces, Freetown (Sierra Leone); Wu Fanghong, E-mail: fanghong.wu@siemens.co [Medical Solutions, Shanghai Branch, Siemens Ltd. (China)

    2010-07-15

    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.

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

    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.

  1. Brain volume perfusion CT performed with 128-detector row CT system in patients with cerebral gliomas: A feasibility study

    Validation of the feasibility and efficacy of volume perfusion computed tomography (VPCT) in the preoperative assessment of cerebral gliomas by applying a 128-slice CT covering the entire tumour. Forty-six patients (25 men, 21 women; mean age 52.8 years) with cerebral gliomas were evaluated with VPCT. Two readers independently evaluated VPCT data, drawing volumes of interest (VOIs) around the tumour according to maximum intensity projection volumes, which were mapped automatically onto the cerebral blood volume (CBV), flow (CBF) and permeability (Ktrans) perfusion datasets. As control, a second VOI was placed in the contralateral healthy cortex. Correlation among perfusion parameters, tumour grade, hemisphere and VOIs was assessed. The diagnostic power of perfusion parameters was analysed by receiver operating characteristics curve analyses. VPCT was feasible in the assessment of the entire tumour extent. Mean values of Ktrans, CBV, CBF in high-grade gliomas were significantly higher compared with low-grade (p < 0.01). Ktrans demonstrated the highest diagnostic (97% sensitivity), positive (100%) and negative (94%) prognostic values. VPCT was feasible in all subjects. All areas of different perfusion characteristics are depicted and quantified in colour-coded 3D maps. The derived parameters correlate well with tumour histopathology, differentiating low- from high-grade gliomas. (orig.)

  2. Brain volume perfusion CT performed with 128-detector row CT system in patients with cerebral gliomas: A feasibility study

    Xyda, Argyro [University Hospital of Goettingen, Department of Neuroradiology, Georg-August University, Goettingen (Germany); University Hospital of Heraklion, Department of Radiology, Crete (Greece); Haberland, Ulrike; Klotz, Ernst [Computed Tomography, Siemens AG Healthcare Sector, Forchheim (Germany); Bock, Hans Christoph [University Hospital of Goettingen, Department of Neurosurgery, Georg-August University, Goettingen (Germany); Jung, Klaus [University Hospital of Goettingen, Department of Medical Statistics, Georg-August University, Goettingen (Germany); Knauth, Michael; Schramm, Ramona; Psychogios, Marios Nikos; Schramm, Peter [University Hospital of Goettingen, Department of Neuroradiology, Georg-August University, Goettingen (Germany); Erb, Gunter [Bracco Imaging Deutschland GmbH, Konstanz (Germany)

    2011-09-15

    Validation of the feasibility and efficacy of volume perfusion computed tomography (VPCT) in the preoperative assessment of cerebral gliomas by applying a 128-slice CT covering the entire tumour. Forty-six patients (25 men, 21 women; mean age 52.8 years) with cerebral gliomas were evaluated with VPCT. Two readers independently evaluated VPCT data, drawing volumes of interest (VOIs) around the tumour according to maximum intensity projection volumes, which were mapped automatically onto the cerebral blood volume (CBV), flow (CBF) and permeability (Ktrans) perfusion datasets. As control, a second VOI was placed in the contralateral healthy cortex. Correlation among perfusion parameters, tumour grade, hemisphere and VOIs was assessed. The diagnostic power of perfusion parameters was analysed by receiver operating characteristics curve analyses. VPCT was feasible in the assessment of the entire tumour extent. Mean values of Ktrans, CBV, CBF in high-grade gliomas were significantly higher compared with low-grade (p < 0.01). Ktrans demonstrated the highest diagnostic (97% sensitivity), positive (100%) and negative (94%) prognostic values. VPCT was feasible in all subjects. All areas of different perfusion characteristics are depicted and quantified in colour-coded 3D maps. The derived parameters correlate well with tumour histopathology, differentiating low- from high-grade gliomas. (orig.)

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

    Goetschi, Stefan, E-mail: goetschi@gmx.net [Institute of Radiology, Triemli Hospital, Birmensdorferstrasse 497, 8063 Zuerich (Switzerland); Umbehr, Martin, E-mail: martin.umbehr@triemli.ch [Urology Clinic, Department of Surgery, Triemli Hospital, Birmensdorferstrasse 497, 8063 Zuerich (Switzerland); Ullrich, Stephan, E-mail: stephan.ullrich@triemli.ch [Institute of Radiology, Triemli Hospital, Birmensdorferstrasse 497, 8063 Zuerich (Switzerland); Glenck, Michael, E-mail: michael.glenck@triemli.ch [Institute of Radiology, Triemli Hospital, Birmensdorferstrasse 497, 8063 Zuerich (Switzerland); Suter, Stefan, E-mail: stefan.suter@triemli.ch [Urology Clinic, Department of Surgery, Triemli Hospital, Birmensdorferstrasse 497, 8063 Zuerich (Switzerland); Weishaupt, Dominik, E-mail: dominik.weishaupt@triemli.ch [Institute of Radiology, Triemli Hospital, Birmensdorferstrasse 497, 8063 Zuerich (Switzerland)

    2012-11-15

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

  4. Multidetector-row CT of tumour–bowel fistula: Experience at a tertiary cancer centre

    Aim: To study the clinical and multidetector computed tomography (MDCT) features of tumour–bowel fistula (TBF). Materials and methods: Fifty-one patients (27 women; mean age 57.4 years, range 30–77years) with TBF presenting to our institution between January 2005 and February 2012 were identified retrospectively from the radiology database. MDCT images before, at, and subsequent to diagnosis of TBF were reviewed by three radiologists in consensus; clinical presentation, management, and outcome were documented from electronic medical records. Results: Of 51 patients, small bowel (n = 22) was the most common site with gastrointestinal stromal tumour (GIST) being the most common sarcoma subtype (n = 10). TBF was treatment-associated (TTBF) in 40 patients [78%; 22 of whom had received molecular targeted therapy (MTT)], and spontaneous (STBF) in 11 patients (22%). Thirty-one patients (61%) were symptomatic at the time of TBF detection. TTBF was more often asymptomatic (19/40 versus 1/11; Fisher's exact test p = 0.03). In the TTBF group, 16 had a partial response, seven had stable disease, and 17 had progressive disease. Treatment was discontinued or changed to an alternative regimen in 27/40 patients, and 13/40 patients continued with the same regimen. TBF persisted in 27/33 patients (82%) who underwent CT follow-up. Thirty-one of the 51 patients were deceased at the time of analysis. Time from diagnosis of TBF to death was shorter with STBF (1.8 months) than with TTBF (6.4 months). Conclusion: TBF is often associated with MTT and can be seen with treatment response or progression. TTBF is more frequently asymptomatic. TBF is usually managed conservatively by discontinuing treatment, but often persists on CT follow-up

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

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

  6. Study of optimal exposure windows using 320-Detector rows dynamic volume CT

    Gang Sun

    2010-12-01

    Full Text Available Gang Sun1, Min Li1, Li Li1, Guo-ying Li1, Zhi-wei Jing21Departments of Medical Imaging, 2Medical Statistics, Jinan Military General Hospital, Shandong Province, ChinaAbstract: The purpose of this study was to determine the optimal electrocardiographic (ECG pulsing windows and evaluate the effect on reduced dose and accuracy using 320-detector rows dynamic volume computed tomography (DVCT. A total of 170 patients were prospectively studied. The optimal reconstruction windows were analyzed in 76 patients scanned using retrospective ECG gating. Forty-seven patients were scanned by the predicted triggering windows. The optimal positions of exposure intervals according to different heart rates were evaluated. Optimal image quality, radiation dose, and diagnostic accuracy were then investigated by applying optimal triggering windows. The optimal ECG pulsing windows were determined as follows: when heart rate was <70 beats per minute, the exposure windows should be preset at 60%–80%; for a heart rate 70–90 beats per minute at 70%–90%; and for a heart rate ≥90 beats per minute at 30%–50%. The radiation dose for patients scanned with prospective ECG gating was significantly lower (5.9 versus 12.9 mSv, P < 0.001. However, because two or three heart beats were needed when heart rate was >70 beats per minute, the radiation dose increased with increasing heart rate for both retrospective and prospective ECG gating (r = 0.64, P < 0.001 and r = 0.59, P < 0.001, respectively. On the basis of a per segment analysis, overall sensitivity was 98.0% (49/50, specificity was 99.2% (602/607, the positive predictive value was 90.7% (49/54, and the negative predictive value was 99.8% (602/603. In conclusion, DVCT has the potential to provide high image quality across a wide range of heart rates using an optimized ECG pulsing window. However, it is recommended to control heart rate below 70 beats per minute, if possible, to decrease the radiation dose

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

    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.)

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

    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.)

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

    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.)

  10. Multiphasic multidetector-row CT (MDCT) in detection and staging of transitional cell carcinomas of the upper urinary tract

    The aim of this study was to evaluate the potential of multiphasic multidetector-row CT (MDCT) in the detection and staging of transitional cell carcinomas (TCC) of the upper urinary tract. We performed a retrospective chart review of 39 consecutive patients with 41 histologically verified TCC of the renal pelvis and/or the ureter. The urinary tract was examined using MDCT performing unenhanced and contrast-enhanced scans during the corticomedullary (CMP), nephrographic (NP) and pyelographic phase (PP). Tumors were staged according to the TNM classification. MDCT and histopathological findings were correlated. The attenuation of the lesions was documented in Hounsfield units (HU). In MDCT, all 41 TCC - including two multicentric TCC - were detected. TCC confined to the organ (stage 0a-II) was correctly staged in 28/29 tumors (96.6%). Stage III-IV tumors were correctly staged in 8/12 patients (66.6%). Overall, MDCT was accurate in predicting pathologic TNM stage in 36/41 upper urinary tract TCC (87.8%). There was no significant difference of mean attenuation of TCC between CMP, NP and PP (P>0.05). MDCT with its high spatial and temporal resolution is an accurate tool for detection TCC of the upper urinary tract, with 87.8% accuracy in predicting its stage. (orig.)

  11. Quantitative Features of Liver Lesions, Lung Nodules, and Renal Stones at Multi-Detector Row CT Examinations: Dependency on Radiation Dose and Reconstruction Algorithm.

    Solomon, Justin; Mileto, Achille; Nelson, Rendon C; Roy Choudhury, Kingshuk; Samei, Ehsan

    2016-04-01

    Purpose To determine if radiation dose and reconstruction algorithm affect the computer-based extraction and analysis of quantitative imaging features in lung nodules, liver lesions, and renal stones at multi-detector row computed tomography (CT). Materials and Methods Retrospective analysis of data from a prospective, multicenter, HIPAA-compliant, institutional review board-approved clinical trial was performed by extracting 23 quantitative imaging features (size, shape, attenuation, edge sharpness, pixel value distribution, and texture) of lesions on multi-detector row CT images of 20 adult patients (14 men, six women; mean age, 63 years; range, 38-72 years) referred for known or suspected focal liver lesions, lung nodules, or kidney stones. Data were acquired between September 2011 and April 2012. All multi-detector row CT scans were performed at two different radiation dose levels; images were reconstructed with filtered back projection, adaptive statistical iterative reconstruction, and model-based iterative reconstruction (MBIR) algorithms. A linear mixed-effects model was used to assess the effect of radiation dose and reconstruction algorithm on extracted features. Results Among the 23 imaging features assessed, radiation dose had a significant effect on five, three, and four of the features for liver lesions, lung nodules, and renal stones, respectively (P stones, respectively (P stones, respectively (P stones with MBIR was significantly different than those for the other two algorithms (P < .002 for all comparisons). Although lesion texture was significantly affected by the reconstruction algorithm used (average of 3.33 features affected by MBIR throughout lesion types; P < .002, for all comparisons), no significant effect of the radiation dose setting was observed for all but one of the texture features (P = .002-.998). Conclusion Radiation dose settings and reconstruction algorithms affect the extraction and analysis of quantitative imaging features in

  12. Effect of computer-aided detection as a second reader in multidetector-row CT colonography

    Our purpose was to assess the effect of computer-aided detection (CAD) on lesion detection as a second reader in computed tomographic colonography, and to compare the influence of CAD on the performance of readers with different levels of expertise. Fifty-two CT colonography patient data-sets (37 patients: 55 endoscopically confirmed polyps ≥0.5 cm, seven cancers; 15 patients: no abnormalities) were retrospectively reviewed by four radiologists (two expert, two nonexpert). After primary data evaluation, a second reading augmented with findings of CAD (polyp-enhanced view, Siemens) was performed. Sensitivities and reading time were calculated for each reader without CAD and supported by CAD findings. The sensitivity of expert readers was 91% each, and of nonexpert readers, 76% and 75%, respectively, for polyp detection. CAD increased the sensitivity of expert readers to 96% (P = 0.25) and 93% (P = 1), and that of nonexpert readers to 91% (P = 0.008) and 95% (P = 0.001), respectively. All four readers diagnosed 100% of cancers, but CAD alone only 43%. CAD increased reading time by 2.1 min (mean). CAD as a second reader significantly improves sensitivity for polyp detection in a high disease prevalence population for nonexpert readers. CAD causes a modest increase in reading time. CAD is of limited value in the detection of cancer. (orig.)

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

    Salem, Randa; Remy-Jardin, Martine; Delhaye, Damien; Khalil, Chadi; Teisseire, Antoine; Remy, Jacques [Hospital Calmette, University Center of Lille, Department of Thoracic Imaging, LILLE cedex (France); Delannoy-Deken, Valerie; Duhamel, Alain [University of Lille, Place de Verdun, Department of Medical Statistics, LILLE cedex (France)

    2006-09-15

    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 {beta}-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

  14. Pathologic/high-resolution CT correlation of focal lung lesions 5 mm or less in diameter. Detection and identification by multidetector-row CT

    The purpose of this study was to clarify the limitations of multidetector-row CT (MDCT) in detecting focal lung lesions of 5 mm or less in diameter by pathologic/high-resolution CT (HRCT) correlation. Twenty-two patients who underwent both preoperative HRCT of the entire lobe using MDCT (MD-HRCT) and lobectomy for primary (n=21) or metastatic (n=1) lung tumor were studied. The author attempted to locate any focal lung lesions other than the main tumor throughout the resected and sliced specimens and to identify the opacities corresponding to the macroscopic lesions on MD-HRCT before histopathologic evaluation. Then two observers without pathologic information attempted to detect the lesions on MD-HRCT. Ninety-one lesions of 5 mm or less in diameter were found in 15 patients. Histopathologically, 13 lesions were classified as bronchioloalveolar carcinoma (BAC), 38 as atypical adenomatous hyperplasia (AAH), 9 as reactive hyperplasia (RH), 19 as inflammatory lesion (INF), 8 as solid lesion (SL), and 4 as showing no organizing change. The author, who had knowledge of the gross pathologic examinations, identified the opacities at rates of 100%, 82%, 56%, 42%, and 88% for BAC, AAH, RH, INF, and SL, respectively. The rates of lesion detection in the absence of knowledge of the pathologic examinations were 85%, 58%, 22%, 32%, and 75% for BAC, AAH, RH, INF, and SL, respectively. The rates of identification and detection of lesions more than 3 mm in diameter were 90% and 57%, respectively, while those of lesions less than 2 mm in diameter were 71% and 35%, respectively. MD-HRCT proved to be useful in detecting focal lung lesions of 5 mm or less in diameter; however, it is still difficult to detect lesions of less than 2 mm in diameter. (author)

  15. Evaluation of retrospectively ECG-gated 4-row multidetector CT in patients planned for minimal invasive coronary artery bypass grafting

    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

  16. Differentiation of a Femoral Hernia from an Inguinal Hernia on Isotropic Multidetector-Row CT (MDCT): the Benefit of Inguinal Ligament Coronal-Oblique Images

    This study was designed to evaluate the diagnostic value of the use of inguinal ligament coronal-oblique CT images in the differentiation of femoral hernias from inguinal hernias. A total of 32 patients (with 11 femoral hernias and 21 inguinal hernias) underwent CT imaging. All of the examinations were performed with a 16- multidetector row CT (MDCT) scanner with contrast enhancement, and transverse sections, coronal sections and coronal-oblique CT images were reformed along an imaginary inguinal ligament plane. Two independent observers retrospectively evaluated the CT scans. Image analysis was first performed with only transverse and coronal images. A second analysis was then performed with transverse, coronal and coronal- oblique images. The mean angle difference between coronal and coronal-oblique CT images was 8.0 degrees (range, 0-22 degrees). A radiologist correctly diagnosed the presence of a femoral hernia in nine (82%) of 11 patients and a radiology fellow correctly diagnosed the presence of a femoral hernia in seven (64%) of 11 patients in the first session. Both of the reviewers made the correct diagnosis in all patients in the second session. For inguinal hernias, both reviewers correctly diagnosed all patients during both sessions. The coronal-oblique CT images were the most valuable images for the evaluation of the relationship between hernias of the neck and inguinal ligament. Inguinal ligament coronal-oblique CT images can provide additional diagnostic value in the evaluation of groin hernias

  17. Assessment of vertebral artery stents using 16-slice multi-detector row CT angiography in vivo evaluation: Comparison of a medium-smooth kernel and a sharp kernel

    Objectives: To assess the lumen visibility of extracranial vertebral artery stents examined with 16-slice multi-detector row computed tomography (MDCT) angiography in vivo using a medium-smooth kernel (B30s) and a sharp kernel (B60s), and to compare these with digital subtraction angiography (DSA) after stent placement. Methods: Twenty stents from 20 patients (14 men, 6 women; mean age, 62.7 ± 10.1 years) who underwent CT angiography (CTA) with 16-slice MDCT were retrospectively analyzed. In CT angiograms using a B30s and a B60s, the lumen diameters and CT attenuations of the stented vessels were measured three times by three observers, and artificial luminal narrowing (ALN) was calculated. To assess measurement reliability on CT angiograms, the intraclass correlation coefficient (ICC) was used. DSA served as the reference standard for the in-stent luminal measurements on CT angiography. The median interval between CT angiography and DSA was 1 day (range 1-10). Results: For interobserver reliability, intraclass correlation coefficients for the lumen diameters on CT angiograms with a B30s and a B60s were 0.90 and 0.96, respectively. The lumen diameters on CT angiograms using a B30s were consistently smaller than that on CT angiograms using a B60s (p < 0.01). The mean ALN was 37 ± 7% on CT angiograms using a B30s and 25 ± 9% on CT angiograms using a B60s. The mean CT attenuation in in-stent lumen was 347 ± 55 HU on CT angiograms using a B30s and 295 ± 46 HU on CT angiograms using a B60s. The ALN and CT attenuation within the stented vessels between CT angiograms using a B30s and a B60s was significant (p < 0.01). Conclusions: 16-slice MDCT using a sharp kernel allows good visualization of the stented vessels and is useful in the assessment of vertebral artery stent patency after stent placement.

  18. Patient radiation dose in prospectively gated axial CT coronary angiography and retrospectively gated helical technique with a 320-detector row CT scanner

    Purpose: The aim of this study was to evaluate radiation dose to patients undergoing computed tomography coronary angiography (CTCA) for prospectively gated axial (PGA) technique and retrospectively gated helical (RGH) technique. Methods: Radiation doses were measured for a 320-detector row CT scanner (Toshiba Aquilion ONE) using small sized silicon-photodiode dosimeters, which were implanted at various tissue and organ positions within an anthropomorphic phantom for a standard Japanese adult male. Output signals from photodiode dosimeters were read out on a personal computer, from which organ and effective doses were computed according to guidelines published in the International Commission on Radiological Protection Publication 103. Results: Organs that received high doses were breast, followed by lung, esophagus, and liver. Breast doses obtained with PGA technique and a phase window width of 16% at a simulated heart rate of 60 beats per minute were 13 mGy compared to 53 mGy with RGH technique using electrocardiographically dependent dose modulation at the same phase window width as that in PGA technique. Effective doses obtained in this case were 4.7 and 20 mSv for the PGA and RGH techniques, respectively. Conversion factors of dose length product to the effective dose in PGA and RGH were 0.022 and 0.025 mSv mGy-1 cm-1 with a scan length of 140 mm. Conclusions: CTCA performed with PGA technique provided a substantial effective dose reduction, i.e., 70%-76%, compared to RGH technique using the dose modulation at the same phase windows as those in PGA technique. Though radiation doses in CTCA with RGH technique were the same level as, or some higher than, those in conventional coronary angiography (CCA), the use of PGA technique reduced organ and effective doses to levels less than CCA except for breast dose.

  19. Patient radiation dose in prospectively gated axial CT coronary angiography and retrospectively gated helical technique with a 320-detector row CT scanner

    Seguchi, Shigenobu; Aoyama, Takahiko; Koyama, Shuji; Fujii, Keisuke; Yamauchi-Kawaura, Chiyo [Graduate School of Medicine, Nagoya University, Daikominami, Higashi-ku, Nagoya 461-8673 (Japan) and Department of Medical Technology, Nagoya Daini Red Cross Hospital, Myouken-chou, Showa-ku, Nagoya 466-8650 (Japan); Graduate School of Medicine, Nagoya University, Daikominami, Higashi-ku, Nagoya 461-8673 (Japan); Section of Radiological Protection, National Institute of Radiological Sciences, Anagawa, Inage-ku, Chiba 263-8555 (Japan); Graduate School of Medicine, Nagoya University, Daikominami, Higashi-ku, Nagoya 461-8673 (Japan)

    2010-11-15

    Purpose: The aim of this study was to evaluate radiation dose to patients undergoing computed tomography coronary angiography (CTCA) for prospectively gated axial (PGA) technique and retrospectively gated helical (RGH) technique. Methods: Radiation doses were measured for a 320-detector row CT scanner (Toshiba Aquilion ONE) using small sized silicon-photodiode dosimeters, which were implanted at various tissue and organ positions within an anthropomorphic phantom for a standard Japanese adult male. Output signals from photodiode dosimeters were read out on a personal computer, from which organ and effective doses were computed according to guidelines published in the International Commission on Radiological Protection Publication 103. Results: Organs that received high doses were breast, followed by lung, esophagus, and liver. Breast doses obtained with PGA technique and a phase window width of 16% at a simulated heart rate of 60 beats per minute were 13 mGy compared to 53 mGy with RGH technique using electrocardiographically dependent dose modulation at the same phase window width as that in PGA technique. Effective doses obtained in this case were 4.7 and 20 mSv for the PGA and RGH techniques, respectively. Conversion factors of dose length product to the effective dose in PGA and RGH were 0.022 and 0.025 mSv mGy{sup -1} cm{sup -1} with a scan length of 140 mm. Conclusions: CTCA performed with PGA technique provided a substantial effective dose reduction, i.e., 70%-76%, compared to RGH technique using the dose modulation at the same phase windows as those in PGA technique. Though radiation doses in CTCA with RGH technique were the same level as, or some higher than, those in conventional coronary angiography (CCA), the use of PGA technique reduced organ and effective doses to levels less than CCA except for breast dose.

  20. Evaluation of right ventricular function by 64-row CT in patients with chronic obstructive pulmonary disease and cor pulmonale

    Purpose: The aim of this study was to investigate the clinical application value of right ventricle (RV) function measured by 64 multi-detector row CT (MDCT) in patients with chronic obstructive pulmonary disease (COPD) and cor pulmonale. Materials and methods: Sixty-three consecutive patients with COPD and cor pulmonale were referred for electrocardiographically gated MDCT for evaluation of suspected or known coronary artery disease. Magnetic resonance imaging (MRI) for cardiac function analysis was performed on the same day. The MDCT and MRI examinations were successfully completed in 58 patients. Forty-six patients with COPD were divided into three groups according to the severity of disease by the pulmonary function test (PFT). Twelve patients diagnosed as cor pulmonale and 32 control subjects were also included. The RV function and myocardial mass (MM) were obtained by 64-MDCT and 1.5 T cardiac MRI in all of the groups. The results were compared among the groups using the Newman–Keuls method. Pearson's correlation was used to evaluate the relationship between the right ventricular ejection fraction (RVEF) and MM with the PFT results in COPD and cor pulmonale patients. Results: The RVEF was significantly lower in patients with severe COPD and cor pulmonale than it was in those patients with mild or moderate COPD (P < 0.01). There were strong correlations between MDCT and MRI (r = 0.826 for RV MM, r = 0.982 and 0.969 for RV EDV and RV ESV, r = 0.899 for RVEF) and between MDCT results and forced expiratory volume in 1 s (r = 0.787 for RVEF, r = −0.774 for RV MM) in all patients. Conclusion: MDCT can accurately quantify RV function and MM. The RVEF and RV MM measured by MDCT correlate well with the severity of disease as determined by PFT in patients with COPD and cor pulmonale. The assessment of right ventricular function is clinically important for evaluation of the severity of COPD, which may provide an objective basis for therapeutic strategy.

  1. Computed tomography angiography of carotid and coronary artery via a single-bolus injection protocol: a feasibility study using 320-row multidetector CT

    To investigate the feasibility of using a single-dose injection protocol in CT angiography (CTA) of the carotid and coronary artery with 320-row multidetector CT. A total of 82 consecutive patients with suspected carotid artery disease underwent an original CTA protocol aiming at capturing the extra-cranial carotid arteries and coronary arteries simultaneously using 320-row MDCT. The image quality, attenuation, and CNRs of the carotid and coronary arteries were assessed. The lag time (between two separated volumetric acquisitions) was compared between patients with and without cardiac venous opacification (CVO). The contrast medium volume and radiation dose were recorded. The image quality was 99.4 % diagnostic in carotid and 86.9 % in coronary artery segments. The mean attenuation of carotid and coronary arteries ranged from 462.2 Hu to 533.7 Hu, 415.9 Hu to 454.7 Hu respectively. The mean CNR of the carotid and coronary artery ranged from 15.8 to 18.9 and 17.7 to 20.4 respectively. The lag time in patients with and without CVO was 5.75 ± 1.64 s vs. 4.21 ± 1.14 s (p < 0.05). The mean radiation dose was 6.6 ± 4.1 mSv.The mean contrast media volume was 71.9 ± 9.1 ml. The carotid and coronary artery can be imaged simultaneously via our original single-dose injection CTA protocol using 320-row CT with adequate image quality. (orig.)

  2. Heart-rate-adapted image reconstruction in multidetector-row cardiac CT: influence of physiological and technical prerequisite on image quality

    The purpose of this study was to develop strategies for optimal image reconstruction in multidetector-row cardiac CT and to discuss the results in the context of individual heart rate, cardiac physiology, and technical prerequisite. Sixty-four patients underwent multidetector-row cardiac CT. Depending on the heart rate either a single-segmental reconstruction (SSR) or an adaptive two-segmental reconstruction (ASR) was applied. Image reconstruction was done either antegrade (a) or retrograde (r) in relation to the R-peak. Reconstruction of all data sets was performed at multiple time points within the t-wave/p-wave interval, differing from each other by 50 ms. In addition, each reconstruction was assigned to one of six reconstruction intervals (A-F), each corresponding to a specific event in the cardiac cycle. While no significant time points were found for absolute values, the following interval/reconstruction technique combinations provided significant better image quality: F/r at HR 65 bpm for all segments (p≤0.002). The results show that in order to achieve optimal image quality, image reconstruction has to be adjusted to each patient's ECG curve and heart rate individually. The moment of reconstruction should be determined as absolute rather than as relative distance from the previous R-peak. (orig.)

  3. Perfusion measurement of the whole upper abdomen of patients with and without liver diseases: Initial experience with 320-detector row CT

    Objectives: To report initial experience of upper abdominal perfusion measurement with 320-detector row CT (CTP) for assessment of liver diseases and therapeutic effects. Materials and methods: Thirty-eight patients who were suspected of having a liver disease underwent CTP. There were two patients with liver metastases, two with hemangiomas, and four with cirrhosis (disease group). CTP was repeated for four patients with cirrhosis or hepatocellular carcinoma (HCC) after therapy. Hepatic arterial and portal perfusion (HAP and HPP) and arterial perfusion fraction (APF), and arterial perfusion (AP) of pancreas, spleen, stomach, and intra-portal HCC were calculated. For disease-free patients (normal group), the values were compared among liver segments and among pancreatic and gastric parts. The values were compared between groups and before and after therapy. Results: No significant differences were found in the normal group except between APFs for liver segments 3 and 5, and fundus and antrum. Mean HAP and APF for the disease group were significantly higher than for the normal group. APF increased after partial splenic embolization or creation of a transjugular intrahepatic portosystemic shunt. HPP increased and AP of intra-portal HCC decreased after successful radiotherapy. Conclusions: 320-Detector row CT makes it possible to conduct perfusion measurements of the whole upper abdomen. Our preliminary results suggested that estimated perfusion values have the potential to be used for evaluation of hepatic diseases and therapeutic effects

  4. Perfusion measurement of the whole upper abdomen of patients with and without liver diseases: Initial experience with 320-detector row CT

    Kanda, Tomonori, E-mail: k_a@hotmail.co.jp [Department of Radiology, Kobe University Graduate School of Medicine, 7-5-2 Kusunokicho, Chuoku, Kobe 650-0017 (Japan); Yoshikawa, Takeshi, E-mail: yoshikaw@med.kobe-u.ac.jp [Department of Radiology, Kobe University Graduate School of Medicine, 7-5-2 Kusunokicho, Chuoku, Kobe 650-0017 (Japan); Ohno, Yoshiharu, E-mail: yosirad@kobe-u.ac.jp [Department of Radiology, Kobe University Graduate School of Medicine, 7-5-2 Kusunokicho, Chuoku, Kobe 650-0017 (Japan); Fujisawa, Yasuko, E-mail: yasuko1.fujisawa@toshiba.co.jp [Toshiba Medical Systems Co., 1385 Shimoishigami, Otawara 324-0036 (Japan); Kanata, Naoki, E-mail: takikina12345@yahoo.co.jp [Department of Radiology, Kobe University Graduate School of Medicine, 7-5-2 Kusunokicho, Chuoku, Kobe 650-0017 (Japan); Yamaguchi, Masato, E-mail: masato03310402@yahoo.co.jp [Department of Radiology, Kobe University Graduate School of Medicine, 7-5-2 Kusunokicho, Chuoku, Kobe 650-0017 (Japan); Seo, Yasushi, E-mail: yseo@med.kobe-u.ac.jp [Division of Gastroenterology, Department of Internal Medicine, Kobe University Graduate, School of Medicine, 7-5-2 Kusunokicho, Chuoku, Kobe 650-0017 (Japan); Yano, Yoshihiko, E-mail: yanoyo@med.kobe-u.ac.jp [Division of Gastroenterology, Department of Internal Medicine, Kobe University Graduate, School of Medicine, 7-5-2 Kusunokicho, Chuoku, Kobe 650-0017 (Japan); Koyama, Hisanobu, E-mail: hkoyama@med.kobe-u.ac.jp [Department of Radiology, Kobe University Graduate School of Medicine, 7-5-2 Kusunokicho, Chuoku, Kobe 650-0017 (Japan); Kitajima, Kazuhiro, E-mail: kazu10041976@yahoo.co.jp [Department of Radiology, Kobe University Graduate School of Medicine, 7-5-2 Kusunokicho, Chuoku, Kobe 650-0017 (Japan); Takenaka, Daisuke, E-mail: daisuket@med.kobe-u.ac.jp [Department of Radiology, Kobe University Graduate School of Medicine, 7-5-2 Kusunokicho, Chuoku, Kobe 650-0017 (Japan); and others

    2012-10-15

    Objectives: To report initial experience of upper abdominal perfusion measurement with 320-detector row CT (CTP) for assessment of liver diseases and therapeutic effects. Materials and methods: Thirty-eight patients who were suspected of having a liver disease underwent CTP. There were two patients with liver metastases, two with hemangiomas, and four with cirrhosis (disease group). CTP was repeated for four patients with cirrhosis or hepatocellular carcinoma (HCC) after therapy. Hepatic arterial and portal perfusion (HAP and HPP) and arterial perfusion fraction (APF), and arterial perfusion (AP) of pancreas, spleen, stomach, and intra-portal HCC were calculated. For disease-free patients (normal group), the values were compared among liver segments and among pancreatic and gastric parts. The values were compared between groups and before and after therapy. Results: No significant differences were found in the normal group except between APFs for liver segments 3 and 5, and fundus and antrum. Mean HAP and APF for the disease group were significantly higher than for the normal group. APF increased after partial splenic embolization or creation of a transjugular intrahepatic portosystemic shunt. HPP increased and AP of intra-portal HCC decreased after successful radiotherapy. Conclusions: 320-Detector row CT makes it possible to conduct perfusion measurements of the whole upper abdomen. Our preliminary results suggested that estimated perfusion values have the potential to be used for evaluation of hepatic diseases and therapeutic effects.

  5. Suitability of helical multislice acquisition technique for routine unenhanced brain CT: an image quality study using a 16-row detector configuration

    Subjective and objective image quality (IQ) criteria, radiation doses, and acquisition times were compared using incremental monoslice, incremental multislice, and helical multislice acquisition techniques for routine unenhanced brain computed tomography (CT). Twenty-four patients were examined by two techniques in the same imaging session using a 16-row CT system equipped with 0.75-width detectors. Contiguous ''native'' 3-mm-thick slices were reconstructed for all acquisitions from four detectors for each slice (4 x 0.75 mm), with one channel available per detector. Two protocols were tailored to compare: (1) one-slice vs four-slice incremental images; (2) incremental vs helical four-slice images. Two trained observers independently scored 12 subjective items of IQ. Preference for the technique was assessed by one-tailed t test and the interobserver variation by two-tailed t test. The two observers gave very close IQ scores for the three techniques without significant interobserver variations. Measured IQ parameters failed to reveal any difference between techniques, and an approximate half radiation dose reduction was obtained by using the full 16-row configuration. Acquisition times were cumulatively shortened by using the multislice and the helical modality. (orig.)

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

    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 × 10−3mm2/s) differed significantly from that of normal gastric wall (1.77 ± 0.25 × 10−3 mm2/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 detection of

  7. Rowing Injuries

    Hosea, Timothy M.; Hannafin, Jo A.

    2012-01-01

    Context: Rowing is one of the original modern Olympic sports and was one of the most popular spectator sports in the United States. Its popularity has been increasing since the enactment of Title IX. The injury patterns in this sport are unique because of the stress applied during the rowing stroke. Evidence Acquisition: This review summarizes the existing literature describing the biomechanics of the rowing stroke and rowing-related injury patterns. Data were obtained from previously publish...

  8. Multi-organ perfusion CT in the abdomen using a 320-detector row CT scanner: Preliminary results of perfusion changes in the liver, spleen, and pancreas of cirrhotic patients

    Purpose: To utilize 320-detector row CT in perfusion CT of multiple abdominal organs and to compare the tissue perfusion between patients with and without liver cirrhosis. Materials and methods: This study included 21 patients with cirrhosis and 20 without cirrhosis. The 320-detector row CT scanner enabled multi-organ perfusion CT without requiring the scanner table to be moved. Perfusion was calculated using the maximum slope model for the aorta, the portal vein, the right and left lobes of the liver, the head and body of the pancreas, the spleen, and the corpus and antrum of the stomach. Perfusion in each organ of patients with and without cirrhosis was compared. Results: Portal venous perfusion of the right and left lobes of the liver in patients with cirrhosis (117 and 100 mL min−1 100 mL−1, respectively) was significantly less than that in patients without cirrhosis (213 and 174 mL min−1 100 mL−1, respectively; p = 0.0081 and 0.0294, respectively). Arterial perfusion of the spleen (111 mL min−1 100 mL−1) and the body of the pancreas (112 mL min−1 100 mL−1) in patients with cirrhosis was also significantly decreased compared with that in patients without cirrhosis (spleen, 162 mL min−1 100 mL−1, p = 0.0020; body of pancreas, 133 mL min−1 100 mL−1, p = 0.0405). Conclusion: The results of the perfusion CT suggest that arterial perfusion of the spleen and the body of the pancreas, as well as portal perfusion of the liver, in cirrhotic patients was decreased compared with that in non-cirrhotic patients

  9. Coronal multiplanar reconstruction view from isotropic voxel data sets obtained with multidetector-row CT. Assessment of detection and size of mediastinal and hilar lymph nodes

    To assess the detection and size of mediastinal and hilar lymph nodes by multiplanar reconstruction (MPR) view from isotropic voxel data sets obtained with multidetector-row computed tomography (MDCT). Thin-section CT of 27 patients with mediastinal or hilar lymph node swelling was obtained with a 25.6-cm field of view (FOV), 512 x 512 matrix, and two protocols: 0.5-mm collimation, 0.3-mm interval (Set A), and 2-mm collimation, 1-mm interval (Set B). MPR views with a 0.5-mm slice thickness were obtained from these two data sets. Postcontrast axial CT used 5-mm collimation (set C). Two observers evaluated the presence and cranio-caudal length of swollen lymph nodes. Two other board-certified chest radiologists evaluated all three sets and established a gold standard by consensus. The accuracy of detection was 76%, 73%, and 68% for sets A, B, and C, respectively. There was a significant difference between sets A and C (McNemar's test: p0.05). The cranio-caudal length of lymph nodes was significantly correlated with the gold standard only in set A (Pearson's correlation coefficient: r=0.53, p<0.05). Non-contrast enhanced coronal MPR views constructed from isotropic voxel data sets may be substituted for axial enhanced CT for the evaluation of mediastinal and hilar lymph nodes. (author)

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

    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.)

  11. Intra-individual comparison of patient acceptability of multidetector-row CT colonography and double-contrast barium enema

    AIMS: To compare the subjective acceptability of CT colonography in comparison with barium enema in older symptomatic patients, and to ascertain preferences for future colonic investigation. MATERIALS AND METHODS: The study population comprised 78 persons aged 60 years or over with symptoms suggestive of colorectal neoplasia, who underwent CT colonography followed the same day by barium enema. A 25-point questionnaire was administered after each procedure and an additional follow-up questionnaire a week later. Responses were compared using Wilcoxon matched pairs testing, Mann-Whitney test statistics and binomial exact testing. RESULTS: Participants suffered less physical discomfort during CT colonography (p=0.03) and overall satisfaction was greater compared with barium enema (p=0.03). On follow-up, respondents reported significantly better tolerance of CT colonography (p=0.002), and were less prepared to undergo barium enema again (p<0.001). Of 52 subjects expressing an opinion, all preferred CT to barium enema. CONCLUSION: Patient satisfaction was higher with CT colonography than barium enema. CT colonography caused significantly less physical discomfort and was overwhelmingly preferred by patients

  12. Adult Moyamoya disease: 320-Multidetector row CT for evaluation of revascularization in STA–MCA bypasses surgery

    Purpose: To evaluate the utility of 320-multidetector row whole-brain computed tomography perfusion (WBCTP) and whole-head subtracted dynamic angiography (WHSDCTA) for assessing the revascularization of blood flow after superficial temporal artery (STA) to middle cerebral artery (MCA) bypass surgery in adults with Moyamoya disease (MD) in the short and long term. Patients and methods: 320-multidetector row WBCTP and WHSDCTA were applied in 20 patients with MD before and after surgery (for an average of 3 days and 3 months). The bypass arteries were investigated using WHSDCTA and compared with DSA. The regions of interests (ROIs) in the surgical and mirror sides of the cerebral cortex were drawn on a Vitrea Workstation. Cerebral blood volume (CBV), time to peak (TTP), cerebral blood flow (CBF), mean transit time (MTT), and delay time were recorded. Preoperative and postoperative perfusion parameters in the MCA distribution were compared using the paired t-test. Results: WHSDCTA could clearly demonstrate 24 bypass arteries in 26 arteries for 20 patients, results which were in accordance with the results of digital subtraction angiography (DSA). When comparing preoperative values to those within 3 days after surgery, only TTP and delay time were significantly different (P < 0.05). Values of CBV, TTP, CBF, delay time, and MTT 3 months after surgery were significantly different (P < 0.05) from those of preoperative perfusion. Conclusion: These data suggest that 320-multidetector row WBCTP and WHSDCTA can be used to evaluate the revascularization of blood flow after STA–MCA bypass surgery in patients with MD in the short and long term

  13. Adult Moyamoya disease: 320-Multidetector row CT for evaluation of revascularization in STA–MCA bypasses surgery

    Tian, Bing; Xu, Bing; Liu, Qi; Hao, Qiang; Lu, Jianping, E-mail: cjr.lujianping@vip.163.com

    2013-12-01

    Purpose: To evaluate the utility of 320-multidetector row whole-brain computed tomography perfusion (WBCTP) and whole-head subtracted dynamic angiography (WHSDCTA) for assessing the revascularization of blood flow after superficial temporal artery (STA) to middle cerebral artery (MCA) bypass surgery in adults with Moyamoya disease (MD) in the short and long term. Patients and methods: 320-multidetector row WBCTP and WHSDCTA were applied in 20 patients with MD before and after surgery (for an average of 3 days and 3 months). The bypass arteries were investigated using WHSDCTA and compared with DSA. The regions of interests (ROIs) in the surgical and mirror sides of the cerebral cortex were drawn on a Vitrea Workstation. Cerebral blood volume (CBV), time to peak (TTP), cerebral blood flow (CBF), mean transit time (MTT), and delay time were recorded. Preoperative and postoperative perfusion parameters in the MCA distribution were compared using the paired t-test. Results: WHSDCTA could clearly demonstrate 24 bypass arteries in 26 arteries for 20 patients, results which were in accordance with the results of digital subtraction angiography (DSA). When comparing preoperative values to those within 3 days after surgery, only TTP and delay time were significantly different (P < 0.05). Values of CBV, TTP, CBF, delay time, and MTT 3 months after surgery were significantly different (P < 0.05) from those of preoperative perfusion. Conclusion: These data suggest that 320-multidetector row WBCTP and WHSDCTA can be used to evaluate the revascularization of blood flow after STA–MCA bypass surgery in patients with MD in the short and long term.

  14. Carotid artery stenosis quantification: Concordance analysis between radiologist and semi-automatic computer software by using Multi-Detector-Row CT angiography

    Saba, Luca, E-mail: lucasaba@tiscali.it [Department of Radiology, Policlinico Universitario, A.O.U. Cagliari, s.s. 554 Monserrato, Cagliari 09045 (Italy); Department of Vascular Surgery, Policlinico Universitario, A.O.U. Cagliari, s.s. 554 Monserrato, Cagliari 09045 (Italy); Sanfilippo, Roberto; Montisci, Roberto [Department of Vascular Surgery, Policlinico Universitario, A.O.U. Cagliari, s.s. 554 Monserrato, Cagliari 09045 (Italy); Calleo, Giancarlo [Institute of Radiology, Ospedale San Giovanni di Dio, A.O.U. Cagliari 46 Hospital Street, 09126 Cagliari (Italy); Mallarini, Giorgio [Department of Radiology, Policlinico Universitario, A.O.U. Cagliari, s.s. 554 Monserrato, Cagliari 09045 (Italy); Institute of Radiology, Ospedale San Giovanni di Dio, A.O.U. Cagliari 46 Hospital Street, 09126 Cagliari (Italy)

    2011-07-15

    Purpose: Carotid artery stenosis quantification is still considered a leading parameter in the choice of the therapeutic option. Our purpose was to asses the concordance between radiologist and a semi-automatic computer software in the stenosis quantification of carotid artery studied by using a Multi-Detector-Row CT angiography (MDCTA). Methods and material: 45 patients studied by using a 40-detector row CT scanner were retrospectively analyzed. Carotid artery stenosis was quantified by one high experienced radiologist in vessel analysis and by using a dedicated software. Carotid artery stenosis was calculated according to the ECST method. Bland-Altman statistics was used to measure the inter- and intra-concordance between radiologist and software and correlation coefficient between measures were performed by using nonparametric Spearmann correlation statistic. A p value < 0.05 was considered to mean statistical significance. Results: A strength correlation according to linear regression (correlation Spearman'{rho} coefficient = 0.975; p < 0.0001) between radiologist and software of vessel analysis was observed. Between first and second stenosis of carotid artery quantification performed by radiologist and software of vessel analysis we observed a Spearman'{rho} coefficient = 0.943 (p < 0.0001) and a Spearman'{rho} coefficient = 0.9879; (p < 0.0001) respectively. Conclusions: Our results indicated that there is a strength correlation according to linear regression between stenosis of carotid artery quantification performed by radiologist and semi-automatic software. Reproducibility between measurements performed by semi-automatic software are higher compared to radiologist.

  15. Comparison of 16-row multislice CT angiography with conventional angiography for detection and evaluation of intracranial aneurysms

    Donmez, Halil; Serifov, Elman; Kahriman, Guven [University of Erciyes, School of Medicine, Department of Radiology, Kayseri (Turkey); Mavili, Ertugrul, E-mail: ertmavili@yahoo.com [University of Erciyes, School of Medicine, Department of Radiology, Kayseri (Turkey); Durak, Ahmet Candan [University of Erciyes, School of Medicine, Department of Radiology, Kayseri (Turkey); Menkue, Ahmet [University of Erciyes, School of Medicine, Department of Neurosurgery, Kayseri (Turkey)

    2011-11-15

    Purpose: The aim of this study is to compare the diagnostic performance of 16-row computed tomographic angiography (MDCTA) with digital subtraction angiography (DSA) for the detection and characterization of intracranial aneurysms in patients with nontraumatic subarachnoid hemorrhages (SAH). Materials and methods: One-hundred and twelve consecutive patients with suspected intracranial aneurysm underwent both 16-row MDCTA and DSA. The MDCT angiograms were interpreted in a blinded fashion by using combination with VRI, MIP and MPR techniques. Sensitivity specificity and accuracy were calculated for the CTA and DSA. The results were compared with each other. The DSA reader's interpretation was accepted as the reference standard. Results: A total of 164 aneurysms were detected at DSA in 112 patients, no aneurysms were detected by DSA and MDCTA in 16 patients. Eight aneurysms were missed by MDCTA. The overall sensitivity, specificity, and accuracy of MDCTA on a per-aneurysm basis were 95.1%, 94.1%, and 95%, respectively. According to the size of the aneurysm less than 3 mm; sensitivity, specificity and diagnostic accuracy of MDCTA were 86.1%, 94.1%, 88.6%, respectively. Conclusion: This study suggests that MDCTA is equally as sensitive as DSA in the detection of intracranial aneurysms of greater than 3 mm, and it also reveals 100% detection rate for ruptured aneurysms.

  16. Added diagnostic benefit of 16-row whole-body spiral CT in patients with multiple trauma differentiated by region and injury severity according to the ATLS registered concept

    Purpose: to determine the added diagnostic benefit of using MS-CT in multiple trauma patients differentiated by severity of injury and affected body region. Materials and methods: a retrospective analysis was performed of the 16-row whole-body spiral CT findings in 275 multiple trauma patients (73% men, 27% women; age 39.6 ± 18.9 years) with regard to additional findings and new findings obtained with CT compared to the findings obtained by conventional projection radiography and abdominal ultrasound in the emergency room. The additional and new findings were differentiated by body region (head, face, chest, pelvis, abdomen, spine) and the degree of severity according to the three classes of injuries distinguished by the ATLS registered concept (class 1: simple injury, class 2: potentially life threatening, class 3: immediately life threatening). Results: a total of 921 additional findings (findings potentially relevant for further diagnosis and therapy in addition to the findings obtained by conventional radiography or ultrasound) were obtained by MS-CT in all patients. The distribution by number of patients and body region was as follows: 22 neck, 76 face, 125 chest, 112 abdomen, 50 pelvis, and 91 spine. Most additional findings were categorized as potentially life threatening (ATLS class 2). In addition, there were 439 completely new findings, involving the head in 128 patients (mostly ATLS class 3), the face in 18, the chest in 47, the abdomen in 26, and the spine in 9 patients. Most new findings involving the face, abdomen, and spine were ATLS class 2 injuries. (orig.)

  17. 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

    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.)

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

    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 15O-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 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.)

  19. Detection rate and efficiency of lymph node assessment with axial and coronal image reading based on 16 row multislice CT of the neck

    Schreyer, A.G.; Scheibl, K.; Zorger, N.; Dorenbeck, U.; Retzl, G.; Feuerbach, S.; Seitz, J. [Universitaetsklinikum Regensburg - Inst. fuer Roentgendiagnostik (Germany)

    2005-10-01

    Purpose: multislice CT (MSCT) has the advantage of isotropic volumetric data acquisition which allows high resolution data reconstruction in the axial and coronal plane. We evaluate the accuracy and efficiency of coronal reconstruction compared to axial reconstructions of a routinely performed CT scan exemplary in neck lymph node assessment performed on a 16 row MSCT. Material and methods: contrast enhanced neck MSCT of 24 patients with known lymphoma were evaluated prospectively for lymph node assessment. 4 blinded readers evaluated the axial and coronal reconstructions of the same patient. Neck lymph nodes larger than 10 mm were evaluated by their anatomical region (deep jugular chain, submandibular, nuchal). Time for axial and coronal image evaluation was assessed. Detection rate was compared with consensus reading as gold standard. Results: in consensus reading 169 enlarged lymph nodes in the deep jugular chain were found. Detection rate for axial image interpretation was 36.1% with 54.9% in coronal reading. Assessing the submandibular lymph nodes (n = 45) axial interpretation revealed 53.9% with 36.1% in coronal reading. Evaluation time for axial reading was in all but one reader significantly longer (mean 176 seconds) than in coronal reading (mean 129 seconds). (orig.)

  20. Detection rate and efficiency of lymph node assessment with axial and coronal image reading based on 16 row multislice CT of the neck

    Purpose: multislice CT (MSCT) has the advantage of isotropic volumetric data acquisition which allows high resolution data reconstruction in the axial and coronal plane. We evaluate the accuracy and efficiency of coronal reconstruction compared to axial reconstructions of a routinely performed CT scan exemplary in neck lymph node assessment performed on a 16 row MSCT. Material and methods: contrast enhanced neck MSCT of 24 patients with known lymphoma were evaluated prospectively for lymph node assessment. 4 blinded readers evaluated the axial and coronal reconstructions of the same patient. Neck lymph nodes larger than 10 mm were evaluated by their anatomical region (deep jugular chain, submandibular, nuchal). Time for axial and coronal image evaluation was assessed. Detection rate was compared with consensus reading as gold standard. Results: in consensus reading 169 enlarged lymph nodes in the deep jugular chain were found. Detection rate for axial image interpretation was 36.1% with 54.9% in coronal reading. Assessing the submandibular lymph nodes (n = 45) axial interpretation revealed 53.9% with 36.1% in coronal reading. Evaluation time for axial reading was in all but one reader significantly longer (mean 176 seconds) than in coronal reading (mean 129 seconds). (orig.)

  1. Experimental 16-row CT evaluation of in-stent restenosis using new stationary and moving cardiac stent phantoms: experimental examination

    Purpose: The aim of this study was to evaluate in-stent restenosis using a newly developed stationary and moving cardiac stent phantom with three built-in artificial stenoses and a 16-row MDCT. Materials and Methods: A newly developed coronary stent phantom with three artificial stenoses - low (approx. 30%), medium (approx. 50%) and high (approx. 70%) - was attached to a moving heart phantom and used to evaluate the ability of 16-row MDCT to visualize in-stent restenosis. High resolution scans (16 x 0.75 mm, 250 mm FOV) were made to identify the baseline for image quality. The non-moving phantom was scanned (16 x 0.75 mm, routine cardiac scan protocol) first without and then with implementation of an ECG signal at various simulated heart rates (HR 40 to 120 bpm) and pitches (0.15 to 0.3). The moving cardiac phantom was scanned at the same simulated heart rates but at a pitch of 0.15. Images were reconstructed at every 10% of the RR interval using a multi-cycle real cone-beam reconstruction algorithm. Multi-planar reformations (MPR) were made for the image evaluation. The image quality was assessed using a three-point scale, and stent patency and stenoses detection were evaluated using a four-point scale. To evaluate the image quality and to grade the stent stenoses, the median values were calculated while considering the reconstruction interval. Results: The image quality for the static phantom was adequate in 97% of the measurements. In this phantom, every stenosis was detected independent of the pitch and heart rate used. The dynamic stent phantom yielded the best results at 0%, 40%, and 50% of the RR interval at a pitch of 0.15. The low stenosis was visible at a simulated heart rate of up to 80 bpm. Patency can be detected at heart rates greater than 80 bpm. (orig.)

  2. Diagnosis of Small-Bowel Diseases: Prospective Comparison of Multi-Detector Row CT Enterography with MR Enterography.

    Masselli, Gabriele; Di Tola, Marco; Casciani, Emanuele; Polettini, Elisabetta; Laghi, Francesca; Monti, Riccardo; Bernieri, Maria Giulia; Gualdi, Gianfranco

    2016-05-01

    Purpose To prospectively compare the accuracies of computed tomographic (CT) enterography and magnetic resonance (MR) enterography for the detection and characterization of small-bowel diseases. Materials and Methods The institutional review board approved the study protocol, and informed consent was obtained from all participants. From June 2009 to July 2013, 150 consecutive patients (81 men and 69 women; mean age, 38.8 years; range, 18-74 years), who were suspected of having a small-bowel disease on the basis of clinical findings and whose previous upper and lower gastrointestinal endoscopy findings were normal, underwent CT and MR enterography. Two independent readers reviewed CT and MR enterographic images for the presence of small-bowel diseases, for differentiating between inflammatory and noninflammatory diseases, and for extraenteric complications. The histopathologic findings of surgical (n = 23) and endoscopic (n = 32) biopsy specimens were used as the reference standard; the results of video-capsule endoscopy (n = 36) and clinical follow-up (n = 59) were used only to confirm the absence of small-bowel disease. Results MR and CT enterography were successfully performed in all 150 patients. Overall sensitivity, specificity, and accuracy, respectively, in identifying patients with small-bowel lesions were 75.9% (41 of 54), 94.8% (91 of 96), and 88.0% (132 of 150) for CT enterography and 92.6% (50 of 54), 99.0% (95 of 96), and 96.7% (145 of 150) for MR enterography. The sensitivity of MR enterography was significantly higher than that of CT enterography for the detection of both overall small-bowel diseases (P = .0159) and neoplastic diseases (P = .0412) but not for the detection of inflammatory diseases (P > .99) or noninflammatory and nonneoplastic diseases (P = .6171). Conclusion MR enterography is more accurate than CT enterography in the detection of small-bowel diseases; MR enterography was more accurate in detecting neoplastic diseases in particular

  3. Rowing Physiology.

    Spinks, W. L.

    This review of the literature discusses and examines the methods used in physiological assessment of rowers, results of such assessments, and future directions emanating from research in the physiology of rowing. The first section discusses the energy demands of rowing, including the contribution of the energy system, anaerobic metabolism, and the…

  4. CT angiography of the coronary arteries with a 16-row spiral tomograph. Effect of spatial resolution on image quality

    Purpose. To evaluate image quality of coronary CT angiography with retrospectively ECG-gated 16 multi-slice spiral CT (MSCT), reconstructed with 0.75 mm slice thickness for optimal spatial resolution and with 1.3 mm slice thickness, to produce spatial resolution comparable to a 4-MSCT.Materials and methods. Ten patients underwent coronary CT angiography with a 16-MSCT (Siemens Sensation 16, Forchheim, Germany) with 0.75 mm detector collimation. Raw helical CT data were retrospectively reconstructed using two different settings. Setting A: B20f smooth kernel, axial MPR with 1.3 mm slice thickness and 0.7 mm increment. Setting B: B35f ''HeartView'' medium-smooth kernel, 0.75 mm slice thickness, 0.5 mm increment. In the axial slices two regions of interest (ROIs) were placed in the area of the aortic root (AR) and more caudal in the area of the left ventricle (LV). Image noise was determined by the standard deviation of the CT numbers.Two readers determined visibility of coronary arteries by standardized maximum intensity projections (MIP) post-processing in left, right anterior and left anterior oblique projection plane from setting A and B. Each projection was rated on a five point rating scale concerning plaque delineation. Points determined for each data set were summed up and used for comparison.Results. No significant difference between the CT-numbers was found for setting A and B (A: 283.0 in AR/295.9 in LV and B: 282,9 in AR/297.2 in LV; p >0.2). However, the image noise was significantly different for setting A and B (A: 4.46 in AR/1.67 in LV and B: 8.16 in AR/7.38 in LV; p <0.01). Better delineation of the coronary arteries and atherosclerotic lesions could be achieved from MIP projections in setting B compared to setting A.Conclusion. Higher image noise is present in coronary 16-MSCT with thin-slice reconstruction compared to simulated 4-MSCT. However the MIP-reconstructions benefit most from the higher spatial resolution. (orig.)

  5. Coronary computed tomography angiography using prospective electrocardiography-gated axial scans with 64-detector computed tomography. Evaluation of stair-step artifacts and padding time

    We compared stair-step artifacts and radiation dose between prospective electrocardiography (ECG)-gated coronary computed tomography angiography (prospective CCTA) and retrospective CCTA using 64-detector CT and determined the optimal padding time (PT) for prospective CCTA. We retrospectively evaluated 183 patients [mean heart rate (HR) <65 beats/min, maximum HR instability <5 beats/min] who had undergone CCTA. We scored stair-step artifacts from 1 (severe) to 5 (none) and evaluated the effective dose in 53 patients with retrospective CCTA and 130 with prospective CCTA (PT 200 ms, n=32; PT 50 ms, n=98). Mean artifact scores were 4.3 in both retrospective and prospective CCTAs. However, statistically more arteries scored <3 (nonassessable) on prospective CCTA (P<0.001). Mean scores for prospective CCTA with 200- and 50-ms PT were 4.1 and 4.3, respectively (no significant difference). The radiation dose of prospective CCTA was reduced by 59.1% to 80.7%. Prospective CCTA reduces the radiation dose and allows diagnostic imaging in most cases but shows more nonevaluable artifacts than retrospective CCTA. Use of 50-ms instead of 200-ms PT appears to maintain image quality in patients with a mean HR <65 beats/min and HR instability of <5 beats/min. (author)

  6. Impaired left ventricular function has a detrimental effect on image quality in multi-detector row CT coronary angiography

    Aim: To determine whether there is a relationship between left ventricular (LV) haemodynamic parameters, circulation times, and arterial contrast opacification that might affect the image quality of computed tomography (CT) coronary angiography. Methods: Thirty-six patients were included in the study: 18 with cardiomyopathy (CM) and LV dilatation of suspected ischaemic aetiology [age 57.9 ± 13.7 years, range 30-77 years; 14 male, four female; body mass index (BMI) = 27.7 ± 4.5, range 25.5-31.8] and 18 controls (age 62.3 ± 9.4 years, range 47-89 years; 10 male, eight female; BMI 27.8 ± 6.6; range 19.2-33.6). Coronary artery image quality was assessed using a three-point visual scale; contrast medium circulation times, aortic root contrast attenuation, and LV functional parameters were studied. Results: Visually reduced contrast opacification impaired image quality more often in the CM group than the control group (27.4 versus 5.1%). A total of 55.6% CM patients had a contrast transit time ranging from 30-75 s; the number of 'unassessable' segments increased with increasing transit time conforming to a fitted quadratic model (R2 = 0.74). The relationship between LV ejection fraction and contrast attenuation may also conform to a quadratic model (R2 = 0.71). Conclusion: LV haemodynamics influence coronary artery opacification using cardiac CT, and users imaging this subgroup must do so with the knowledge of this potential pitfall. The results indicate the need for further studies examining CT protocols in this clinical subgroup

  7. Time efficiency and diagnostic accuracy of new automated myocardial perfusion analysis software in 320-row CT cardiac imaging

    We aimed to evaluate the time efficiency and diagnostic accuracy of automated myocardial computed tomography perfusion (CTP) image analysis software. 320-row CTP was performed in 30 patients, and analyses were conducted independently by three different blinded readers by the use of two recent software releases (version 4.6 and novel version 4.71GR001, Toshiba, Tokyo, Japan). Analysis times were compared, and automated epi- and endocardial contour detection was subjectively rated in five categories (excellent, good, fair, poor and very poor). As semi-quantitative perfusion parameters, myocardial attenuation and transmural perfusion ratio (TPR) were calculated for each myocardial segment and agreement was tested by using the intraclass correlation coefficient (ICC). Conventional coronary angiography served as reference standard. The analysis time was significantly reduced with the novel automated software version as compared with the former release (Reader 1: 43:08 ± 11:39 min vs. 09:47 ± 04:51 min, Reader 2: 42:07 ± 06:44 min vs. 09:42 ± 02:50 min and Reader 3: 21:38 ± 3:44 min vs. 07:34 ± 02:12 min; p < 0.001 for all). Epi- and endocardial contour detection for the novel software was rated to be significantly better (p < 0.001) than with the former software. ICCs demonstrated strong agreement (≥ 0.75) for myocardial attenuation in 93% and for TPR in 82%. Diagnostic accuracy for the two software versions was not significantly different (p 0.169) as compared with conventional coronary angiography. The novel automated CTP analysis software offers enhanced time efficiency with an improvement by a factor of about four, while maintaining diagnostic accuracy.

  8. Improvement of parenchymal and vascular enhancement using saline flush and power injection for multiple-detector-row abdominal CT

    The aim of this study was to determine if a saline solution flush following low dose contrast material bolus improves parenchymal and vascular enhancement during abdominal multiple detector-row computed tomography (MDCT). Forty-one patients (24 men and 17 women; mean age 49 years, age range 27-86 years) underwent abdominal MDCT (collimation 4 x 5 mm, 15-mm table increment, reconstruction interval 5 mm, gantry rotation period 0.8 s) with a single- as well as with a double syringe power injector. Indication for examination were benign and malignant tumors and inflammatory diseases. Patients received 100 ml nonionic contrast material (300 mgI/ml) alone or pushed with 20 ml saline solution. Mean enhancement values for both protocols were measured in the liver, the spleen, the pancreas, the renal cortex, the portal vein, the inferior vena cava and the abdominal aorta. Double syringe power-injector protocol led to significantly higher parenchymal and vascular enhancement than single syringe power-injector protocol (p<0.05). The improvement in mean enhancement of the liver was 9±9 HU, of the spleen 8±10 HU, of the pancreas 7±9 HU, and of the renal cortex 8±20 HU. The improvement in mean enhancement of the portal vein was 10±17 HU of the inferior vena cava 8±13 HU and of the abdominal aorta 10±17 HU. The use of a double syringe power injector with saline flush following contrast material bolus significantly improves parenchymal and vascular enhancement during contrast-enhanced abdominal MDCT with low iodine doses. (orig.)

  9. Accuracy of hydro-multidetector row CT in the local T staging of oesophageal cancer compared to postoperative histopathological results

    To evaluate the accuracy of multidetector computed tomography with water filling (Hydro-MDCT) in the T-staging of patients with oesophageal cancer. There were 131 consecutive patients who were preoperatively and prospectively examined in the prone position on arterial phase contrast-enhanced MDCT, after ingestion of 1,000-1,500 ml tap water and effervescent granules. Two readers staged the local tumour growth (T-staging) independently. They assessed tumour location, size, presence of stenosis, and morphology of the outer border of the oesophageal wall and perioesophageal fat planes on CT. CT findings were compared with histopathological results from resected specimens. Data were analyzed using the SPSS statistical package. Both readers obtained a high sensitivity of 95% and a high positive predictive value of 96%. Accurate local staging was achieved in 76.3% and 68.7% for readers 1 and 2, respectively. Inter-reader agreement was excellent (weighted κ value of 0.93 and un-weighted κ of 0.89). Using the hydro-technique and applying specific assessment criteria, MDCT appears to be an accurate, non-invasive diagnostic tool for local tumour staging of oesophageal cancer. (orig.)

  10. Accuracy of hydro-multidetector row CT in the local T staging of oesophageal cancer compared to postoperative histopathological results

    Ba-Ssalamah, Ahmed; Matzek, Wolfgang; Baroud, Susanne; Bastati, Nina; Weber, Michael; Herold, Christian J. [Medical University of Vienna, Department of Radiology, Vienna (Austria); Zacherl, Johannes; Schoppmann, Sebastian F. [Medical University of Vienna, Department of Radiology, Vienna (Austria); Medical University of Vienna, Department of Surgery, Vienna (Austria); Hejna, Michael [Medical University of Vienna, Department of Radiology, Vienna (Austria); Medical University of Vienna, Department of Oncology, Vienna (Austria); Wrba, Fritz [Medical University of Vienna, Department of Radiology, Vienna (Austria); Medical University of Vienna, Department of Pathology, Vienna (Austria); Gore, Richard M. [University of Chicago Pritzker School of Medicine, Department of Radiology, Chicago, IL (United States)

    2011-11-15

    To evaluate the accuracy of multidetector computed tomography with water filling (Hydro-MDCT) in the T-staging of patients with oesophageal cancer. There were 131 consecutive patients who were preoperatively and prospectively examined in the prone position on arterial phase contrast-enhanced MDCT, after ingestion of 1,000-1,500 ml tap water and effervescent granules. Two readers staged the local tumour growth (T-staging) independently. They assessed tumour location, size, presence of stenosis, and morphology of the outer border of the oesophageal wall and perioesophageal fat planes on CT. CT findings were compared with histopathological results from resected specimens. Data were analyzed using the SPSS statistical package. Both readers obtained a high sensitivity of 95% and a high positive predictive value of 96%. Accurate local staging was achieved in 76.3% and 68.7% for readers 1 and 2, respectively. Inter-reader agreement was excellent (weighted {kappa} value of 0.93 and un-weighted {kappa} of 0.89). Using the hydro-technique and applying specific assessment criteria, MDCT appears to be an accurate, non-invasive diagnostic tool for local tumour staging of oesophageal cancer. (orig.)

  11. Multidetector row CT angiography of the abdominal aorta and lower extremities in patients with peripheral arterial occlusive disease: diagnostic accuracy and interobserver agreement

    Romano, Maurizio E-mail: maurizio.romano@mailcmn.area.na.cnr.it; Mainenti, Pier Paolo; Imbriaco, Massimo; Amato, Bruno; Markabaoui, Karim; Tamburrini, Oscar; Salvatore, Marco

    2004-06-01

    Purpose: To evaluate the accuracy of four channel multidetector row CT angiography (MDCTA) of the abdominal aorta and lower extremities arteries compared with digital subtraction angiography (DSA). Materials and methods: In our prospective study 42 patients with peripheral vascular occlusive disease (27 M, 15 F, age range 40-79 years) underwent MDCTA and DSA within 5 days. Images were blindly interpreted by two radiologists. Maximum intensity projections (MIP), multiplanar (MPR) reformations, three-dimensional (3D) reconstructions as well as axial images were available for analysis of MDCTA. DSA were analyzed on hard copies. Results: Overall sensitivity and specificity of MDCTA were 93 and 95%, respectively, with positive and negative predictive values of 90 and 97%. Overall diagnostic accuracy was 94%. Normal arterial segments and 100% occlusions were correctly identified in all cases by MDCTA. Moderately stenotic segments interpretation in the calves appeared to be more controversial, but no statistical difference in accuracy of MDCTA in the infrapopliteal district arteries was noted with respect to accuracy in the more proximal arterial bed. Good to excellent interobserver and intraobserver agreement were observed, with k values greater than 0.80. Conclusions: MDCTA of the abdominal aorta and lower extremities is an accurate imaging modality in clinical practice when compared with DSA.

  12. Evaluation of time-related changes in lung detail findings after radiation therapy to the chest using multidetector-row CT. Usefulness of precision scanning

    Time-related changes in lung detail findings after radiation therapy to the chest were evaluated using multidetector-row CT. The frequency of individual findings and time-related changes in percent incidence of findings were compared between ordinary scanning at 3 mm raw thickness and 8 mm recon thickness, and precision scanning set at 0.5 mm for both parameters. For both scanning methods, the most frequently detected finding was ground-glass opacity (GGO). For all findings other than GGO and consolidation, the frequency of detection was greater with precision scanning than with ordinary scanning. GGO was also the finding showing the greatest difference in frequency of detection between the two scanning methods; because ordinary scanning tended to overvalue GGO, a demonstrative experiment was conducted using a lung detail phantom. Regarding time-related changes in percent incidence of findings, precision scanning was equivalent or superior to ordinary scanning at all time points except after 3 months. These results, combined with the more accurate evaluation of various lung detail changes after radiation therapy to the chest, including GGO (reversible lesion), suggest the usefulness of precision scanning in combination with ordinary scanning. (author)

  13. Usefulness of the long-axis and short-axis reformatted images of multidetector-row CT in evaluating T-factor of the surgically resected pancreaticobiliary malignancies

    Purpose: To evaluate the diagnostic efficacy of curved planar reformations along the duct (long-axis CPR) and series of reformations perpendicular to the duct (short-axis MPR) in evaluating T-factors of pancreaticobiliary malignancy. Materials and methods: Twenty-five patients with surgically proven pancreaticobiliary malignancy (12 bile duct cancers and 13 pancreas cancers) were evaluated. A dynamic study was performed with multidetector-row CT with four detectors, and reconstructed with 1 mm thickness and intervals. Tracing the center of the duct system on axial images, long-axis CPR images and serial short-axis MPR images were obtained. Two radiologists interpreted the T factor of the diseases three times: session (1), axial images only; session (2), axial, coronal and sagittal multiplanar reformation images; and session (3), axial, long-axis CPR, and short-axis MPR images. Receiver operating characteristic curves were analyzed. Results: In evaluations of bile duct cancer, Az values of (3) (0.95, 0.92) were higher than those of (1) (0.89, 0.88) and (2) (0.92, 0.89), with some significant differences. In evaluations of pancreas cancer, Az values of all interpretations were almost equal. Conclusion: Long-axis CPR and short-axis MPR images were suggested to be useful as additional images to the original axial images in evaluating the local extension of bile duct carcinomas

  14. Chronic thromboembolic pulmonary hypertension (CTEPH). Potential role of multidetector-row CT (MD-CT) and MR imaging in the diagnosis and differential diagnosis of the disease

    Wirth, G.; Brueggemann, K.; Bostel, T.; Dueber, C.; Kreitner, K.F. [Universitaetsmedizin Mainz (Germany). Dept. of Radiology; Mayer, E. [Kerckhoff Hospital, Bad Nauheim (Germany). Dept. of Thoracic Surgery

    2014-08-15

    Chronic thromboembolic pulmonary hypertension (CTEPH) can be defined as pulmonary hypertension (resting mean pulmonary arterial pressure of 25 mm Hg or more determined at right heart catheterization) with persistent pulmonary perfusion defects. It is a rare, but underdiagnosed disease with estimated incidences ranging from 0.5% to 3.8% of patients after an acute pulmonary embolism (PE), and in up to 10% of those with a history of recurrent PE. CTEPH is the only form of pulmonary hypertension that can be surgically treated leading to normalization of pulmonary hemodynamics and exercise capacity in the vast majority of patients. The challenges for imaging in patients with suspected CTEPH are fourfold: the imaging modality should have a high diagnostic accuracy with regard to the presence of CTEPH and allow for differential diagnosis. It should enable detection of patients suitable for PEA with great certainty, and allow for quantification of PH by measuring pulmonary hemodynamics (mPAP and PVR), and finally, it can be used for therapy monitoring. This overview tries to elucidate the potential role of ECG-gated multidetector CT pulmonary angiography (MD-CTPA) and MR imaging, and summarizes the most important results that have been achieved so far. Generally speaking, ECG-gated MD-CTPA is superior to MR in the assessment of parenchymal and vascular pathologies of the lung, and allows for the assessment of cardiac structures. The implementation of iodine maps as a surrogate for lung perfusion enables functional assessment of lung perfusion by CT. MR imaging is the reference standard for the assessment of right heart function and lung perfusion, the latter delineating typical wedge-shaped perfusion defects in patients with CTEPH. New developments show that with MR techniques, an estimation of hemodynamic parameters like mean pulmonary arterial pressure and pulmonary vascular resistance will be possible. CT and MR imaging should be considered as complementary

  15. Chronic thromboembolic pulmonary hypertension (CTEPH). Potential role of multidetector-row CT (MD-CT) and MR imaging in the diagnosis and differential diagnosis of the disease

    Chronic thromboembolic pulmonary hypertension (CTEPH) can be defined as pulmonary hypertension (resting mean pulmonary arterial pressure of 25 mm Hg or more determined at right heart catheterization) with persistent pulmonary perfusion defects. It is a rare, but underdiagnosed disease with estimated incidences ranging from 0.5% to 3.8% of patients after an acute pulmonary embolism (PE), and in up to 10% of those with a history of recurrent PE. CTEPH is the only form of pulmonary hypertension that can be surgically treated leading to normalization of pulmonary hemodynamics and exercise capacity in the vast majority of patients. The challenges for imaging in patients with suspected CTEPH are fourfold: the imaging modality should have a high diagnostic accuracy with regard to the presence of CTEPH and allow for differential diagnosis. It should enable detection of patients suitable for PEA with great certainty, and allow for quantification of PH by measuring pulmonary hemodynamics (mPAP and PVR), and finally, it can be used for therapy monitoring. This overview tries to elucidate the potential role of ECG-gated multidetector CT pulmonary angiography (MD-CTPA) and MR imaging, and summarizes the most important results that have been achieved so far. Generally speaking, ECG-gated MD-CTPA is superior to MR in the assessment of parenchymal and vascular pathologies of the lung, and allows for the assessment of cardiac structures. The implementation of iodine maps as a surrogate for lung perfusion enables functional assessment of lung perfusion by CT. MR imaging is the reference standard for the assessment of right heart function and lung perfusion, the latter delineating typical wedge-shaped perfusion defects in patients with CTEPH. New developments show that with MR techniques, an estimation of hemodynamic parameters like mean pulmonary arterial pressure and pulmonary vascular resistance will be possible. CT and MR imaging should be considered as complementary

  16. Diagnostic Phase of Calcium Scoring Scan Applied as the Center of Acquisition Window of Coronary Computed Tomography Angiography Improves Image Quality in Minimal Acquisition Window Scan (Target CTA Mode) Using the Second Generation 320-Row CT

    Eriko Maeda; Kodai Yamamoto; Shigeaki Kanno; Kenji Ino; Nobuo Tomizawa; Masaaki Akahane; Rumiko Torigoe; Kuni Ohtomo

    2016-01-01

    Objective. To compare the image quality of coronary computed tomography angiography (CCTA) acquired under two conditions: 75% fixed as the acquisition window center (Group 75%) and the diagnostic phase for calcium scoring scan as the center (CS; Group CS). Methods. 320-row cardiac CT with a minimal acquisition window (scanned using “Target CTA” mode) was performed on 81 patients. In Group 75% (n = 40), CS was obtained and reconstructed at 75% and the center of the CCTA acquisition window was ...

  17. Depiction of variants of the portal confluence venous system using multidetector row CT. Analysis of 916 cases

    Krumm, P.; Schraml, C.; Bretschneider, C.; Seeger, A.; Klumpp, B.; Kramer, U.; Claussen, C.D.; Miller, S. [Universitaetsklinikum Tuebingen (Germany). Abt. fuer Diagnostische und Interventionelle Radiologie

    2011-12-15

    Purpose: Detailed knowledge of the venous mesenteric system is important for gastrointestinal surgery, particularly for transplantation planning and surgery and for the comprehension of perioperative complications that may influence patient outcome. Data about the mesenteric venous anatomy in the literature varies substantially. The purpose of this study was to categorize venous mesenteric variants and to determine their incidence. Materials and Methods: We included 916 patients requiring diagnostic abdominal CT in the portal venous phase. The mesenteric vein anatomy was categorized as follows: 1. the inferior mesenteric vein (IMV) enters the splenic vein (SV); 2. the IMV enters into the angle of the confluence of the SV and superior mesenteric vein (SMV) forming the portal vein (PV); 3. the IMV enters the SMV; 4. seven rare variants. We measured the diameters of the veins and distances from the confluence to the IMV origins. Results: The frequency of variants was: 1. 37.6 %, 2. 28.8 %; 3. 19.2 %. The rare variants totaled 14.4 %. The average vessel diameters measured in cm: PV 1.48; SV 1.02; SMV 1.2; IMV 0.5. The mean IMV entering distances were 1.66 cm in variant 1 and 0.75 cm in variant 3. Conclusion: The three common variants (1, 2 and 3) are the most relevant ones. 14.4 % of patients had different anatomic variants. The variability of the mesenteric venous system was higher than previously published. Knowledge of rare variants is important to avoid complications in abdominal surgery. (orig.)

  18. Evaluation of middle cerebral artery stents using multidetector row CT angiography in vivo study: comparison of the three different kernels

    Background: There are very few reports assessing middle cerebral artery (MCA) stents using multidetector computed tomography (MDCT). Purpose: To assess MCA stents using multidetector CT angiography (CTA) in vivo evaluation: the differences in the CTA results according to the three different kernels. Material and Methods: We retrospectively evaluated 27 MCA stents from 26 patients who underwent CTA with 16- and 64-slice MDCT after percutaneous transluminal angioplasty and stenting (PTAS). By CTA, using medium-smooth kernel (B30), medium-sharp kernel (B50), and sharp kernel (B60), the lumen diameter, artificial luminal narrowing (ALN), and subjective visibility score of the stented vessels were evaluated. The subjective visibility score ranged from 1 (poor quality) to 5 (excellent) using a five-point scale. Results: There were excellent inter-observer agreements for the lumen diameter measurements (P < 0.001). The mean diameter of the stented vessels was 2.10 ± 0.31 mm on digital subtraction angiography (DSA), 0.93 ± 0.20 mm on CTA using B30, 1.18 ± 0.27 mm on CTA using B50, and 1.29 ± 0.29 mm on CTA using B60. The mean ALN was 55.7 ± 6.0% on CTA using B30, 43.8 ± 7.5% on CTA using B50, and 38.7 ± 8.3% on CTA using B60. CTA with higher kernels had a smaller ALN than images with smaller kernels. The median subjective visibility score on the CTA using B50 was 3, which was higher than for the other kernels. The differences in the lumen diameter, ALN, and the subjective visibility score of the stented vessels on CTA using the three different kernels was statistically significant (P < 0.001). Conclusion: The sharp kernel was better to assess the lumen diameter and ALN, but was inferior to the medium-sharp kernel for in-stent evaluation due to high image-to-noise. CTA with medium-sharp kernel showed good lumen visibility and acceptable ALN for MCA stents. This could therefore be a non-invasive, readily applicable clinical method for assessing MCA stent patency after

  19. Evaluation of middle cerebral artery stents using multidetector row CT angiography in vivo study: comparison of the three different kernels

    Jang, Jin Hee; Lim, Yeon Soo; Lee, Youn Joo; Yoo, Won Jong; Sung, Mi Sook (Dept. of Radiology, Bucheon St Mary' s Hospital, Coll. of Medicine, The Catholic Univ. of Korea, Bucheon (Korea, Republic of)), email: wjyu@catholic.ac.kr; Kim, Bum Soo (Dept. of Radiology, Seoul St Mary' s Hospital, Coll. of Medicine, The Catholic Univ. of Korea, Seoul (Korea, Republic of))

    2012-05-15

    Background: There are very few reports assessing middle cerebral artery (MCA) stents using multidetector computed tomography (MDCT). Purpose: To assess MCA stents using multidetector CT angiography (CTA) in vivo evaluation: the differences in the CTA results according to the three different kernels. Material and Methods: We retrospectively evaluated 27 MCA stents from 26 patients who underwent CTA with 16- and 64-slice MDCT after percutaneous transluminal angioplasty and stenting (PTAS). By CTA, using medium-smooth kernel (B30), medium-sharp kernel (B50), and sharp kernel (B60), the lumen diameter, artificial luminal narrowing (ALN), and subjective visibility score of the stented vessels were evaluated. The subjective visibility score ranged from 1 (poor quality) to 5 (excellent) using a five-point scale. Results: There were excellent inter-observer agreements for the lumen diameter measurements (P < 0.001). The mean diameter of the stented vessels was 2.10 +- 0.31 mm on digital subtraction angiography (DSA), 0.93 +- 0.20 mm on CTA using B30, 1.18 +- 0.27 mm on CTA using B50, and 1.29 +- 0.29 mm on CTA using B60. The mean ALN was 55.7 +- 6.0% on CTA using B30, 43.8 +- 7.5% on CTA using B50, and 38.7 +- 8.3% on CTA using B60. CTA with higher kernels had a smaller ALN than images with smaller kernels. The median subjective visibility score on the CTA using B50 was 3, which was higher than for the other kernels. The differences in the lumen diameter, ALN, and the subjective visibility score of the stented vessels on CTA using the three different kernels was statistically significant (P < 0.001). Conclusion: The sharp kernel was better to assess the lumen diameter and ALN, but was inferior to the medium-sharp kernel for in-stent evaluation due to high image-to-noise. CTA with medium-sharp kernel showed good lumen visibility and acceptable ALN for MCA stents. This could therefore be a non-invasive, readily applicable clinical method for assessing MCA stent patency after

  20. Reducing radiation dose in 64-row spiral CT coronary angiography: study based on individualized scan dosage protocol

    Objective: To investigate the methods of reducing radiation dose in CT coronary angiography through optimizing individualized scan dosage protocol. Methods: Two hundred patients (group A) underwent coronary CTA examination which was performed with fixed 120 kV and variable mA according to their BMI. The mA was set as 150-300 mA (BMI < 18.5 kg/m2), 300-500 mA (18.5 kg/m2 ≤ BMI < 25.0 kg/m2), and 500-800 mA (BMI ≥ 25.0 kg/m2). When all examinations were finished, a linear regression was employed to analyze the correlation between mA and BMI, body surface (Suf), image noise (SD) respectively. The results of the analysis were used to formulate a regression equation, which was further used to establish a table list for quick search on how much mA that individualized coronary CTA scan would need. Another 200 patients (group B) enrolled for the individualized scan were scanned under new protocol that previous study established. The tube voltage was 100 and 120 kV. The tube current was variable according to the data in the table list. One-way ANOVA and Kruskal-wallis H test were used for statistics. Results: Regression equation between mA and BMI, Suf, SD was: mA =17.984 × BMI + 169.149 × Suf-2.282 × SD-361.039. The SD (group A: 32.08 ± 5.80, group B: 28.60±4.47), dose index volume (CTDIvol) [group A: (41.97 ± 11.37) mGy, group B: (33.18±10.07) mGy], effective dose(ED) [group A: (10.91 ±3.07) mSy, group B: (8.83 ±2.72)mSv] had significant differences between the two groups (F=43.45, 63.71, 49.07 respectively, P<0.01 for all). The SD and ED results obtained in group B were better than those in group A. Conclusion: Better performances were obtained when BMI combined Suf was used as a new individualized protocol than when BMI was used only, which means good image quality and lower radiation dosage in coronary CTA examination. (authors)

  1. On-the-fly generation of multiplanar reformation images independent of CT scanner type.

    Jeong, Dong Kyun; Lee, Kyoung Ho; Kim, Bo Hyoung; Kim, Kil Joong; Kim, Young Hoon; Bajpai, Vasundhara; Shin, Yeong Gil

    2008-09-01

    We propose a system that automatically generates multiplanar reformation (MPR) images on-the-fly, which is independent of computed tomography (CT) scanner type. Triggered by digital imaging communication in medicine (DICOM) Storage Commitment or in a time threshold manner, this system generates MPR images from received thin-section CT data sets with predefined reformation parameters and then sends MPR images to DICOM stations. Users can specify the reformation parameters and the destination of the resulting MPR images for each CT study description. A pilot system was tested for 3 months. From thin-section data sets received from two 16- and one 64-detector-row CT scanners, this system generated MPR images and sent them to the picture archiving and communication system (PACS) without failure or any additional human operation. For 143 test thin-section CT studies (172-4,761 images in each study), the time to store reformatted images (axial and coronal with 5-mm thicknesses and 4-mm intervals) in PACS after the completion of the CT scan ranged from 92 to 1,772 s (mean +/- SD, 555.1 +/- 509.4). PMID:17384976

  2. The added diagnostic value of 64-row multidetector CT combined with contrast-enhanced US in the evaluation of hepatocellular nodule vascularity: implications in the diagnosis of malignancy in patients with liver cirrhosis

    The aim of this study was to assess the added diagnostic value of contrast-enhanced US (CEUS) combined with 64-row multidetector CT (CT) in the assessment of hepatocellular nodule vascularity in patients with liver cirrhosis. One hundred and six cirrhotic patients (68 male, 38 female; mean age ± SD, 70 ± 7 years) with 121 biopsy-proven hepatocellular nodules (72 hepatocellular carcinomas, 10 dysplastic and 15 regenerative nodules, 12 hemangiomas, and 12 other benignancies) detected during US surveillance were prospectively recruited. Each nodule was scanned by CEUS during the arterial (10-40 s), portal venous (45-90 s), and delayed sinusoidal phase (from 100 s after microbubble injection to microbubble disappearance). Nodule vascularity at CEUS, CT, and combined CEUS/CT was evaluated side-by-side by two independent blinded readers who classified nodules as benign or malignant according to reference diagnostic criteria. The combined assessment of CEUS/CT provided higher sensitivity (97%, both readers) than did separate assessment of CEUS (88% reader 1; 87% reader 2) and CT (74% reader 1; 71% reader 2; P < 0.05), while no change in specificity was provided by combined analysis. The combined assessment of hepatocellular nodule vascularity at CT and CEUS improved sensitivity in the diagnosis of malignancy in patients with liver cirrhosis. (orig.)

  3. Evaluation of image quality and spatial resolution of low-dose high-pitch multidetector-row helical high-resolution CT in 11 autopsy lungs and a wire phantom

    The aim of this study was to evaluate whether low-dose high-pitch (6:1) multidetector-row helical high-resolution CT is appropriate for the evaluation of various pulmonary abnormalities, including faint opacities. Eleven autopsy lungs were scanned with a multidetector-row CT scanner using 2.5 mm x 4 beam collimation, effective slice thickness 3 mm, 6:1 pitch, 0.8 second gantry rotation speed, 20 cm Display Fov, high spatial frequency (bone) algorithm, and various radiation doses (120 kVp; 160, 80, 40, 24, and 8 mAs). The image quality of each CT set was assessed as adequate or inadequate for diagnosis by two independent observers. In addition, a wire phantom was scanned with the same parameters in order to describe the modular transfer function (MTF) curves. There was excellent agreement between the observers for the evaluation of image quality (kappa statistic, 0.84). The ratio of images evaluated as inadequate for 8 mAs and 24 mAs was significantly higher than that for 160, 80, and 40 mAs (p<0.01: chi-square test). MTF curves of both 8 and 24 mAs were significantly inferior to those of 40, 80, and 160 mAs (p<0.01, Friedman test), while the MTF curve of 40 mAs was relatively inferior to that of 160 mAs (p<0.05, Friedman test). More than 40 mAs in combination with 120 kVp is preferable for the evaluation of details of lung parenchyma by high-pitch. multidetector-row helical high-resolution CT. (author)

  4. Evaluation of image quality and spatial resolution of low-dose high-pitch multidetector-row helical high-resolution CT in 11 autopsy lungs and a wire phantom

    Johkoh, Takeshi; Honda, Osamu; Yamamoto, Shuji [Osaka Univ., Suita (Japan). Medical School] (and others)

    2001-12-01

    The aim of this study was to evaluate whether low-dose high-pitch (6:1) multidetector-row helical high-resolution CT is appropriate for the evaluation of various pulmonary abnormalities, including faint opacities. Eleven autopsy lungs were scanned with a multidetector-row CT scanner using 2.5 mm x 4 beam collimation, effective slice thickness 3 mm, 6:1 pitch, 0.8 second gantry rotation speed, 20 cm Display Fov, high spatial frequency (bone) algorithm, and various radiation doses (120 kVp; 160, 80, 40, 24, and 8 mAs). The image quality of each CT set was assessed as adequate or inadequate for diagnosis by two independent observers. In addition, a wire phantom was scanned with the same parameters in order to describe the modular transfer function (MTF) curves. There was excellent agreement between the observers for the evaluation of image quality (kappa statistic, 0.84). The ratio of images evaluated as inadequate for 8 mAs and 24 mAs was significantly higher than that for 160, 80, and 40 mAs (p<0.01: chi-square test). MTF curves of both 8 and 24 mAs were significantly inferior to those of 40, 80, and 160 mAs (p<0.01, Friedman test), while the MTF curve of 40 mAs was relatively inferior to that of 160 mAs (p<0.05, Friedman test). More than 40 mAs in combination with 120 kVp is preferable for the evaluation of details of lung parenchyma by high-pitch. multidetector-row helical high-resolution CT. (author)

  5. Localization of bleeding using 4-row detector-CT in patients with clinical signs of acute gastrointestinal hemorrhage; Blutungslokalisation mittels 4-Zeilen-Spiral-CT bei Patienten mit klinischen Zeichen einer akuten gastrointestinalen Haemorrhagie

    Ko, H.S.; Tesdal, K.; Dominguez, E.; Kaehler, G.; Sadick, M.; Dueber, C.; Diehl, S. [Universitaetsklinikum Heidelberg (Germany). Kinderklinik

    2005-12-15

    Purpose: There is no gold-standard regarding the diagnostic work-up and therapy of an acute gastrointestinal (GI) hemorrhage. In most cases endoscopy provides the diagnosis but in a low percentage this modality is not feasible or negative. Purpose of this study was to evaluate the role of multi-phase Multi-Slice-Computertomography (MSCT) as a modality to diagnose and locate the site of acute GI hemorrhage in case of unfeasible or technically difficult endoscopy. Materials and methods: 58 patients, presenting with clinical signs of lower GI hemorrhage, were examined through a 24-month period. Preliminary endoscopy was either negative or unfeasible. Images were obtained with a four-detector row CT with an arterial (4 x 1 mm collimation, 0.8 mm increment, 1.25 mm slice width, 120 kV, 165 mAs) and portal venous series (4 x 2,5 mm collimation, 2 mm increment, 3 mm slice width, 120 kV, 165 mAs). Time interval between endoscopy and CT varied between 30 minutes and 3 hours. The results of the MSCT were correlated with clinical course and surgical or endoscopical treatment. Results: 20 of the 58 patients (34%) undergoing MSCT had a bleeding site identified, thus providing decisive information for the following intervention. In case of a following therapeutic intervention there was 100% correlation regarding the bleeding site. In 38 of the 58 patients (66%), a bleeding site was not identified by MSCT. Twenty of these 38 patients (53%) were stable and required no further treatment. In 18 of these 38 patients further interventional therapy was required due to continuing hemorrhage and in all of those patients the bleeding site was detected by intervention. (orig.)

  6. Multiple Row Helical CT Enhancement Liver Phase Scanning Techniques Discussed in This Paper%多排螺旋CT肝脏增强多期扫描技术的探讨

    邓永绍

    2014-01-01

    目的:探讨多排螺旋 CT 扫描肝脏增强的临床技术研究。方法随机抽取本院2010年4月至2011年8月收治的136例肝脏疾病患者,将其分为两组研究组与对照组各68例,研究组患者给予 GE64排128层螺旋 CT 扫描术进行肝脏增强扫描,对照组患者给予普通螺旋 CT扫描术进行肝脏扫描。结果研究组患者检测率(100%)明显高于对照组(81.5%),两组患者经统计学分析,有显著性差异(P <0.05)。结论 GE64排128层螺旋 CT 扫描技术在扫描肝脏增强的临床应用中,可为肝脏类疾病患者提供明确诊断和治疗可靠的依据。%Objective To explore the multiple row helical CT scanning of liver enhanced clinical technology research. Methods Randomly in April 2010-August 2011 at our hospital treated 136 cases of patients with liver disease, it can be divided into two groups of research group and the control group (n=68), group patients give file row 128 layer spiral CT scanning in hepatic enhancement scan, control group patients give ordinary helical CT scanning of the liver scan. Results The test group patients (100%) is significantly higher than control group (81.5%), two groups of patients after statistics analysis, there are significant differences(P<0.05). Conclusion File row 128 layer spiral CT scanning technique in scanning to enhance the clinical application of liver, for patients with liver diseases to provide reliable basis for diagnosis and therapy.

  7. Estimation of radiation dose and image quality of coronary 320-row area detector CT angiography by optimal prospective ECG-gated protocols for different heart rate

    The purpose of this study is to estimate radiation dose and image quality of electrocardiogram (ECG)-gated coronary 320-area detector CT (ADCT) angiography which was acquired using the protocols that were considered as optimal methods for different heart rates (HR) in 1031 consecutive patients (M/F =580/451, 65±12 yr) without arrhythmias. We set up 5 protocols for 320-ADCT based on the relationship among heart rates, temporal resolution, gantry rotation speed, optimal reconstruction phase and slow filling phase on 64-multidetector-row computed tomography (MDCT), id est (ie), 1) mid-diastolic (75% of risk ratio (RR)) 1 beat scan (moderate disability (MD) 1 beat, N=761 (73.8%)) for HR ≤60, 2) mid-diastolic (75% of RR) 2 beat scan (MD 2 beat, N=135) for 61≤ HR ≤65, 3) end-systolic and mid-diastolic (37-80% of RR) 2 beat scan (embryonic stem (ES)-MD 2 beat, N=92) for 66≤ HR ≤75, 4) end-systolic (R +280-430 ms) 2 beat scan (ES 2 beat, N=21) for 76≤ HR ≤80, and 5) end-systolic (R +250-400 ms) 3 beat scan (ES 3 beat, N=22) for 81≤ HR ≤105. Image quality was classified into 3 categories (excellent (3 points), acceptable (2 points), and unacceptable (1 point)). Scanning time, DLP.e and image quality score were 1.4±0.1 s, 220±59 mGy·cm, 3.0±0.2 points in MD 1 beat, 2.2±0.2 s, 434±118 mGy·cm, 2.9±0.3 points in MD 2 beat, 2.1±0.2 s, 729±229 mGy·cm, 2.7±0.5 points in ES-MD 2 beat, 1.9±0.1 s, 432±148 mGy·cm, 2.2±0.6 points in ES 2 beat, and 2.4±0.2 s, 669±152 mGy·cm, 2.3±0.6 points in ES 3 beat respectively. In conclusion, the prospective ECG-gated scan protocol for coronary 320-ADCT angiography in any HR group was considered reasonable and proper for image quality and radiation dose. (author)

  8. Whole-body low-dose multidetector row-CT in the diagnosis of multiple myeloma: an alternative to conventional radiography

    Horger, Marius; Claussen, Claus D.; Bross-Bach, Ulrike; Vonthein, Reinhard; Trabold, Tobias; Heuschmid, Martin; Pfannenberg, Christina

    2005-05-01

    Objective: The goal of this study was to establish the feasibility of a low-dose whole-body multidetector row-CT (MDCT) protocol in the diagnosis of multiple myeloma (MM), as an alternative to conventional X-ray imaging, which is currently still state-of-the-art in these patients, with emphasis on the comparison of image resolution on axial and multiplanar reformatted (MPR) scans and reduction of radiation dose. Material and methods: 100 patients with known MM, or monoclonal gammopathy of unknown significance (MGUS) underwent unenhanced whole-body MDCT on a 16-slice scanner in a randomised fashion, using a 16 x 1.5 mm collimation and four different energy parameters (40, 50, 60 and 70 mAs). Three different reconstruction algorithms were used in every patient (B40f, B50f and B60f kernel). CT scans were reviewed independently by two radiologists, with regard to correct classification into one of the three known MM stages, and recognition of fracture risk. Thereafter, axial and MPR images were evaluated in consensus by both readers, with respect to image resolution. Diagnosis of osteolytic lesions was performed on the basis of axial and multiplanar reformatted images, whereas the assessment of spinal misalignment and fracture was done only on MPR images. The distribution of image resolution categories (very good, good, sufficient, insufficient for diagnosis) was evaluated depending on following parameters: current time product, patient's weight, bone density and reconstruction algorithm. The effective radiation dose was determined with the aid of an anthropomorphic Alderson Rando-Phantom, using a tube current time product of 40 mAs, and then extrapolating it on all current time products applied in this study on a commercially available software program WinDose (Institute of Medical Physics, Erlangen, Germany). Results: In all 100 patients, image resolution was diagnostic, regardless of scanning parameters, enabling correct classification of multiple myeloma

  9. Whole-body low-dose multidetector row-CT in the diagnosis of multiple myeloma: an alternative to conventional radiography

    Objective: The goal of this study was to establish the feasibility of a low-dose whole-body multidetector row-CT (MDCT) protocol in the diagnosis of multiple myeloma (MM), as an alternative to conventional X-ray imaging, which is currently still state-of-the-art in these patients, with emphasis on the comparison of image resolution on axial and multiplanar reformatted (MPR) scans and reduction of radiation dose. Material and methods: 100 patients with known MM, or monoclonal gammopathy of unknown significance (MGUS) underwent unenhanced whole-body MDCT on a 16-slice scanner in a randomised fashion, using a 16 x 1.5 mm collimation and four different energy parameters (40, 50, 60 and 70 mAs). Three different reconstruction algorithms were used in every patient (B40f, B50f and B60f kernel). CT scans were reviewed independently by two radiologists, with regard to correct classification into one of the three known MM stages, and recognition of fracture risk. Thereafter, axial and MPR images were evaluated in consensus by both readers, with respect to image resolution. Diagnosis of osteolytic lesions was performed on the basis of axial and multiplanar reformatted images, whereas the assessment of spinal misalignment and fracture was done only on MPR images. The distribution of image resolution categories (very good, good, sufficient, insufficient for diagnosis) was evaluated depending on following parameters: current time product, patient's weight, bone density and reconstruction algorithm. The effective radiation dose was determined with the aid of an anthropomorphic Alderson Rando-Phantom, using a tube current time product of 40 mAs, and then extrapolating it on all current time products applied in this study on a commercially available software program WinDose (Institute of Medical Physics, Erlangen, Germany). Results: In all 100 patients, image resolution was diagnostic, regardless of scanning parameters, enabling correct classification of multiple myeloma patients

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

    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.)

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

    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.)

  12. Thin-section chest CT findings in systemic lupus erythematosus with antiphospholipid syndrome: A comparison with systemic lupus erythematosus without antiphospholipid syndrome

    Purpose: To assess thin-section chest CT findings in systemic lupus erythematosus (SLE) with antiphospholipid syndrome (APS), in comparison with SLE without APS. Materials and methods: We retrospectively reviewed the medical records and thin-section CT findings of 17 consecutive patients with an established diagnosis of SLE with APS, comparing with 37 consecutive SLE patients without APS, between 2004 and 2008, and patients who had other autoimmune disease, such as Sjögren syndrome, were excluded. No significant differences were seen between the two groups in age, gender, smoking habits, or history of steroid pulse and biological therapy. CT images of 2 mm thickness obtained with a 16- or 64-detector row CT were retrospectively evaluated by two radiologists in consensus on ultra high-resolution gray-scale monitors. Results: The frequency of thin-section CT abnormalities was higher in SLE with APS group (82%) than in SLE without APS group (43%). Ground-glass opacity (59%), architectural distortion (47%), reticulation (41%), enlarged peripheral pulmonary artery (29%), and mosaic attenuation (29%) were significantly more common in the SLE with APS group than in the SLE without APS group (Fisher's exact test, p < 0.01). Conclusion: SLE patients with APS have increased prevalence of thin-section chest CT abnormalities than those without APS.

  13. Row Row Row Your Boat%划船歌

    Twins

    2011-01-01

    划,划,划起船,顺流而下。乐哈哈,乐哈哈,乐哈哈,乐哈哈,生活只是一个梦。(重复五次)%Row, row, row your boat,Gently down the stream.Merrily, merrily, merrily, merrily,Life is but a dream.(Repeat 5 times)

  14. Use of multidetector-row CT colonography for detection of colorectal neoplasia in patients referred via the Department of Health '2-week-wait' initiative

    Taylor, S.A.; Halligan, S. E-mail: s.halligan@ic.ac.uk; Saunders, B.P.; Morley, S.; Riesewyk, C.; Atkin, W.; Bartram, C.I

    2003-11-01

    AIM: Patients referred under the Department of Health 2-week wait initiative with symptoms of colorectal cancer frequently undergo whole-colon examination. We investigated the use of computed tomography (CT) colonography as an alternative to colonoscopy in this scenario. MATERIALS AND METHODS: Fifty-four consecutive patients, referred via the 2-week wait initiative and scheduled for colonoscopy, consented to undergo multidetector CT colonography immediately before endoscopy. The site and morphology of any polyp or cancer detected by CT was noted and comparison made with subsequent colonoscopy. RESULTS: Colonoscopy detected polyps or cancer in 29 patients (53.7%). CT colonography prospectively detected 18 of 41 (44%) polyps of 1-5 mm, three of four (75%) polyps of 6-9 mm, four of four (100%) polyps 10 mm or larger, and five of six (83%) cancers. The missed cancer occurred early in the series and was a perceptive error. The overall sensitivity, specificity, positive predictive value and negative predictive value of CT colonography for cancer and polyps 10 mm or greater on a per patient basis were 90, 100, 100 and 98%, respectively. CT detected one renal cancer and one colonic cancer, initially missed due to incomplete colonoscopy. CONCLUSION: CT colonography is a robust technique for investigation of symptomatic patients. The learning curve must be overcome for optimal performance.

  15. Use of multidetector-row CT colonography for detection of colorectal neoplasia in patients referred via the Department of Health '2-week-wait' initiative

    AIM: Patients referred under the Department of Health 2-week wait initiative with symptoms of colorectal cancer frequently undergo whole-colon examination. We investigated the use of computed tomography (CT) colonography as an alternative to colonoscopy in this scenario. MATERIALS AND METHODS: Fifty-four consecutive patients, referred via the 2-week wait initiative and scheduled for colonoscopy, consented to undergo multidetector CT colonography immediately before endoscopy. The site and morphology of any polyp or cancer detected by CT was noted and comparison made with subsequent colonoscopy. RESULTS: Colonoscopy detected polyps or cancer in 29 patients (53.7%). CT colonography prospectively detected 18 of 41 (44%) polyps of 1-5 mm, three of four (75%) polyps of 6-9 mm, four of four (100%) polyps 10 mm or larger, and five of six (83%) cancers. The missed cancer occurred early in the series and was a perceptive error. The overall sensitivity, specificity, positive predictive value and negative predictive value of CT colonography for cancer and polyps 10 mm or greater on a per patient basis were 90, 100, 100 and 98%, respectively. CT detected one renal cancer and one colonic cancer, initially missed due to incomplete colonoscopy. CONCLUSION: CT colonography is a robust technique for investigation of symptomatic patients. The learning curve must be overcome for optimal performance

  16. The whole liver perfusion imaging by using 320-row dynamic volume CT scanning with low-dose in evaluating the short-term effect of argon-helium knife treatment for hepatocellular carcinoma

    Objective: To investigate the application of the whole liver perfusion imaging by using 320-row dynamic volume CT scanning with low-dose in evaluating the short-term effect of argon-helium (Ar- He) knife treatment for hepatocellular carcinoma (HCC). Methods: The whole liver CT perfusion scanning was carried out in 20 patients with HCC at 2-3 days before and 30-45 days after Ar-He knife treatment The perfusion scanning parameters were determined before and after the treatment. The results were compared with those obtained from another 20 patients who received plain and enhanced CT scanning. Results: (1) Before Ar-He knife treatment, the HAP and HAPI value of tumor were higher than those of peritumoral and normal liver tissues, while the PVP value of tumor was lower than that of peritumoral and normal liver tissue (P<0.05). No significant difference in the values of HAP, HAPI and PVP existed between peritumoral liver tissue and normal liver tissue, with the P values being 0.394, 0.084 and 0.988 respectively. (2) After Ar-He knife treatment, the HAP and HAPI values of tumor decreased, and the difference was statistically significant (both P<0.05), and PVP value decreased slightly with no statistical significance (P=0.970). All HAP, HAPI and PVP values of peritumoral liver tissues decreased, and the differences between each other were significant difference (all P<0.05); while the values of HAP, HAPI and PVP of normal liver tissue showed no significant significance (all P>0.05). (3) The dosage used for the whole liver perfusion scanning was lower than that used for conventional abdominal plain and enhanced scanning, and the difference was statistically significant (P<0.05). Conclusion: The whole liver perfusion imaging by using 320-row dynamic volume CT scanning with low-dose is an effective method to evaluate the short-term curative effect of Ar-He knife for HCC. (authors)

  17. Value of 64-row spiral CT three-dimensional reconstruction in the repair of tibial plateau fractures%64排螺旋CT三维重建在胫骨平台骨折修复中的价值

    丁燕萍; 杨莹

    2015-01-01

    背景:胫骨平台骨折会抑制膝关节正常功能,严重损伤患者下肢功能,而早期诊断措施对预后效果具有关键作用。以往研究虽已存在多层螺旋 CT 三维重建技术对胫骨平台骨折诊断的相关报道,但将其诊断效果与 X射线检查方式对比较为鲜见。  目的:分析64排螺旋CT三维重建在胫骨平台骨折修复诊治中的应用效果,并与传统X射线诊治结果进行对比。  方法:选择无锡市第九人民医院2012年10月至2013年10月收治的30例胫骨平台骨折患者,对患者进行64排螺旋CT扫描三维重建以及X射线片检查,对检查结果进行分析对比。CT扫描应用GE64排螺旋CT机,扫描范围为胫骨近端,三维重建间距为1 mm,完成扫描后上传工作平台完成图像重建。  结果与结论:通过64排螺旋CT三维重建检查,胫骨平台骨折的程度、有无塌陷、碎骨片存在及移位等均可清晰显示,按照HOHI分型:8例Ⅰ型,7例Ⅱ型,4例Ⅲ型,5例Ⅳ型,3例Ⅴ型,3例Ⅵ型,确诊率为100%;X射线诊断结果显示有25例确诊,有3例为疑似诊断,2例不能确诊,确诊率为83%,两种方式确诊率比较差异有显著性意义(P OBJECTIVE:To analyze the application effect of 64-row spiral CT three-dimensional reconstruction in the repair, diagnosis and treatment of tibial plateau fractures, and compare with diagnostic outcomes of traditional X-ray. METHODS:A total of 30 patients with tibial plateau fractures were selected from Ninth People’s Hospital of Wuxi City from October 2012 to October 2013. Patients were subjected to 64-row spiral CT scanning, three-dimensional reconstruction and X-ray plain film inspection. The inspection results were analyzed and compared. CT scanning used GE64 row spiral CT. Scanning range was the proximal tibia. Spacing of reconstruction was 1 mm. After completing the scan, data were uploaded to a working platform, and

  18. Dose evaluation for foetal computed tomography with a 320-row unit in wide-volume mode and an 80-row unit in helical scanning mode: a phantom study

    The purpose of this study was to evaluate the maternal and foetal effective doses during foetal computed tomography (CT) and to compare the radiation dose, dose profile and image noise on 80-row CT in helical scanning mode and 320-row CT in wide-volume scanning mode. The radiation doses were measured using thermoluminescent dosemeters implanted at various organ sites of an anthropomorphic pregnant phantom. The foetal doses in the 320-row multi-detector CT (MDCT) and 80-row MDCT units were higher than the volume CT dose index (CTDIvol). The dose profile in the 320-row MDCT overlapped in two places but showed no overlap in the 80-row MDCT. There were no significant differences in image noise between the two scanning modes. The foetal dose evaluation by CTDIvol may underestimate the foetal radiation risk. When using the wide-volume mode, operators must take into account the number of scans and overlap between volumetric sections. (authors)

  19. Assessment of coronary artery aneurysms in paediatric patients with Kawasaki disease by multidetector row CT angiography: feasibility and comparison with 2D echocardiography

    Transthoracic ECHO is the locally accepted method for coronary surveillance of patients with Kawasaki disease but it may have limited visualization in the older child. To assess the feasibility of multidetector CT (MDCT) angiography in the follow-up of coronary artery aneurysms in children with previous Kawasaki disease. Six children (5 boys, 1 girl; mean age 11.5 years) with known Kawasaki disease and coronary artery involvement underwent CT coronary angiography using 16-detector MDCT. The visualized lengths and diameter of all coronary segments were measured. The number, size and location of coronary artery aneurysms were recorded and compared with recent ECHO. Twelve coronary artery aneurysms (seven saccular, five fusiform) were identified by MDCT angiography. One saccular aneurysm at the junction of the distal right coronary artery and posterior descending artery was not detected by ECHO while the remaining six in proximal segments were detected by both modalities. Two of five fusiform aneurysms were not detected by ECHO due to their small sizes. Excellent agreement was found between CT and ECHO for maximal diameter and length of the visualized aneurysms. MDCT angiography accurately defines coronary artery aneurysms. It is more sensitive for detecting aneurysms at distal coronary segments and fusiform aneurysms of small size

  20. Characterization of Dose in a TC of 64-Detectors used in pediatrics. Evaluation of the effects of the Over beaming and Over ranging; Caracterizacion de dosis en un TC de 64 detectores utilizado en pediatria. Evaluacion de los efectos del Overbeaming y Overranging

    Garcia Castanon, P.; Roch Gonzalez, M.; Rodriguez Martin, G.; Espana Lopez, M. L.; Giner Sala, M.

    2013-07-01

    The objective of this study is to evaluate the contribution of effects over beaming and over ranging dose received by the patient in a TC multislice with 64 detectors, installed at a children's hospital, for the different acquisition modes available, in order to assess the adequacy of the protocols pre-set for Pediatrics and more accurately assess the received dose. (Author)

  1. Diagnostic evaluation of the craniocervical vascular system with a 16-slice multi-detector row spiral CT - protocols and first experiences

    Purpose. The newly developed 16-slice multi detector row computed tomography (MDCT) allows for isotropic imaging at rotation times under 500 ms. We aim to describe our first experiences with this novel technology in the diagnostic imaging of the craniocervical vascular system.Methods. The craniocervical vascular system of 8 consecutive patients was examined with a standardized protocol with the new 16-slice MDCT. The volume covered included the carotid arteries from their origin at the aortic arch and the intracranial arterial and venous vessels in their entirety. Homogeneity of contrast, contrast-to-parenchyma ratios, image quality and radiation doses were assessed.Results. A homogeneous vessel-to-parenchyma ratio was reached in the carotids as well as in the intracranial arterial and venous vessels. Image quality was rated as excellent in all patients. The estimated mean effective radiation dose amounted to 2.31 mSv +/-0.57, the mean dose length product to 608 mGy*cm +/-151.Conclusion. The newly developed 16-slice MDCT technology appears to be a promising tool in the diagnostic assessment of the cervicocranial vessels. (orig.)

  2. 64排CT气道成像技术在气道异物检查中的临床应用%Clinical application of 64 rows CT airway imaging in the diagnosis of tracheal bronchus foreign body

    赵庆; 齐晨晖; 金艳

    2014-01-01

    目的:评价64排CT气道成像技术对气管支气管异物检查的诊断价值。方法对50例临床怀疑气道异物的患者应用GE Light Speed 64排容积CT(VCT)进行容积扫描,将所得的容积数据经0.625 mm重建后传至工作站,运用CT仿真内窥镜(CTVE)、多平面重组技术(MPR)、容积再现技术+透明化处理(VR+Raysum)、最小密度投影(MinP)对图像进行后处理重建,以支气管镜检查为金标准,评估64排CT检查的敏感性和特异性,并采用χ2检验比较不同后处理方法与支气管镜诊断气管异物形态符合率。结果64排CT扫描结合气道成像技术诊断气道异物的敏感性为100%,特异性为60%,准确率为96%;不同后处理方法(CTVE、MPR、VR+Ray-sum、MinP 4种方法结合)诊断异物形态与支气管镜检查的符合率分别为:98%、87%、82%、42%、100%,不同后处理方法与支气管镜诊断气管异物形态符合率之间差异有统计学意义(χ2=4.810,P<0.05)。结论64排CT气道成像结合不同后处理方法能够提高气道异物诊断的准确性,不同后处理方法联合应用诊断异物形态对指导内窥镜检查或手术有重要意义。%Objective To evaluate the value of 64 rows CT airway imaging in the diagnosis of tracheal bronchus foreign body. Methods Fifty patients with suspected airway foreign body underwent GE Light Speed 64 rows VCT volume scan. The volume data after 0.625 mm reconstruction was send to the workstation, and was recon-structed with CTVE, MPR,VR+ Raysum, MinP. Then taking bronchoscopy as a gold standard, we assessed the sensi-tivity and specificity of 64 rows CT. And we compared the coincidence rate between various post-processing method of airway foreign body and bronchoscopy by Chi square test. Results The sensitivity of 64 rows CT airway imaging in the diagnosis of airway foreign body was 100%, the specificity of it was 60%, and the accuracy of it was 96% . The

  3. Comparison between Carotid Artery Wall Thickness Measured by Multidetector Row Computed Tomography Angiography and Intimae-Media Thickness Measured by Sonography

    Živorad N. Savić; Ivan I. Soldatović; Milan D. Brajović; Aleksandra M. Pavlović; Dušan R. Mladenović; Vesna D. Škodrić-Trifunović

    2011-01-01

    The increased thickness of the carotid wall >1 mm is a significant predictor of coronary and cerebrovascular diseases. The purpose of our study was to assess the agreement between multidetector row computed tomography angiography (MDCTA) in measuring carotid artery wall thickness (CAWT) and color Doppler ultrasound (CD-US) in measuring intimae-media thickness (IMT). Eighty-nine patients (aged 35–81) were prospectively analyzed using a 64-detector MDCTA and a CD-US scanner. Continuous data wer...

  4. Non-invasive evaluation of the coronary venous system in patients with chronic systolic heart failure by 64-detector computed tomography

    Background: Imaging coronary venous systems to guide transcatheter cardiac interventions are becoming increasingly important, particularly in heart failure patients who are selected for cardiac resynchronization therapy (CRT). Failure of left ventricular (LV) lead placement during the procedure has been attributed to the inability to insert catheters into the coronary sinus and the lack of suitable side branches. Purpose To comparatively assess the value of a 64-detector MDCT examination in visualizing the cardiac veins and evaluating the morphological characteristics of the coronary venous system in patients with and without chronic systolic heart failure (SHF). Material and Methods A 64-detector MDCT examination of the heart was performed in 26 consecutive patients (five women, 21 men; mean age 57.80 ± 12.05 years; range 27-81 years) with chronic SHF. The morphological characteristics of the coronary venous system, such as the diameter, the distances between the venous tributaries, the angle and the tortuosity, were evaluated. The group was compared with a subgroup of 52 subjects without SHF (LV ejection fraction >40%) matched for age, sex, and the risk factors for coronary artery disease. Results: The coronary sinus (CS), great cardiac vein (GCV), anterior interventricular vein (AIV), and posterior interventricular vein (PIV) were visualized in all 78 individuals. The posterior vein of the left ventricle (PVLV) (63/78), left marginal vein (LMV) (72/78), and the small cardiac vein (SCV) (50/78) were visualized in SHF and control patients (p = NS). The lengths between venous tributaries were higher (p > 0.05) and more dilated (P < 0.001 for CS, GCV, AIV, PVLV, LMV; p = 0.001 for PIV) in the cases with SHF compared with the control population. The angle between the CS-GCV axis and the venous branches was wider (p = 0.02 for LMV and PIV, p = 0.001 for PVLV) and did not have any correlation with the LV diameter in cases with SHF. There was no difference between the

  5. The relevance of image quality indices for dose optimization in abdominal multi-detector row CT in children: experimental assessment with pediatric phantoms

    This study assessed and compared various image quality indices in order to manage the dose of pediatric abdominal MDCT protocols and to provide guidance on dose reduction. PMMA phantoms representing average body diameters at birth, 1 year, 5 years, 10 years and 15 years of age were scanned in a four-channel MDCT with a standard pediatric abdominal CT protocol. Image noise (SD, standard deviation of CT number), noise derivative (ND, derivative of the function of noise with respect to dose) and contrast-to-noise ratio (CNR) were measured. The 'relative' low-contrast detectability (rLCD) was introduced as a new quantity to adjust LCD to the various phantom diameters on the basis of the LCD1% assessed in a Catphan (registered) phantom and a constant central absorbed dose. The required variations of CTDIvol16 with respect to phantom size were analyzed in order to maintain each image quality index constant. The use of a fixed SD or CNR level leads to major dose ratios between extreme patient sizes (factor 22.7 to 44 for SD, 31.7 to 51.5 for CNR2.8%), whereas fixed ND and rLCD result in acceptable dose ratios ranging between factors of 2.9 and 3.9 between extreme phantom diameters. For a 5-9 mm rLCD1%, adjusted ND values range between -0.84 and -0.11 HU mGy-1. Our data provide guidance on dose reduction on the basis of patient dimensions and the required rLCD (e.g., to get a constant 7 mm rLCD1% for abdominal diameters of 10, 13, 16, 20 and 25 cm, tube current-time product should be adjusted in order to obtain CTDIvol16 values of 6.2, 7.2, 8.8, 11.6 and 17.7 mGy, respectively).

  6. Estudio del oído con TC Multidetector de 64 canales 64 - Detector CT findings in the study of the ear

    María Lourdes Mallo; Cecilia C. Giordanengo; Carlos A. Bertona; Juan José Bertona; Cecilia Gigena; María Paula Florez

    2010-01-01

    El oído es una estructura anatómica compleja. Su estudio y comprensión resultan un reto diario para el radiólogo, siendo la tomografía computada una herramienta esencial para su estudio. La tomografía computada convencional con cortes finos en planos axiales y coronales permite una buena visualización de las diferentes estructuras. Sin embargo, se necesitan tiempos prolongados para su realización y posicionamientos incómodos o intolerables para muchos pacientes. Además la visualización de alg...

  7. Estudio del oído con TC Multidetector de 64 canales 64 - Detector CT findings in the study of the ear

    María Lourdes Mallo

    2010-12-01

    Full Text Available El oído es una estructura anatómica compleja. Su estudio y comprensión resultan un reto diario para el radiólogo, siendo la tomografía computada una herramienta esencial para su estudio. La tomografía computada convencional con cortes finos en planos axiales y coronales permite una buena visualización de las diferentes estructuras. Sin embargo, se necesitan tiempos prolongados para su realización y posicionamientos incómodos o intolerables para muchos pacientes. Además la visualización de algunas de sus estructuras es limitada. La tomografía axial computada multidetector de 64 canales a nuestro medio permite optimizar el estudio de la compleja y pequeña anatomía del oído. La realización de adquisiciones volumétricas con cortes de 0,5 mm, con reconstrucciones multiplanares en los tres planos básicos, en planos curvos y reconstrucciones tridimensionales, hacen posible la visualización detallada de las estructuras en escasos segundos y en condiciones cómodas para el paciente. Nuestro propósito en este artículo es demostrar la utilidad de las reconstrucciones, particularmente en planos oblicuos, para identificar y analizar los diferentes reparos anatómicos del oído y alcanzar la visualización óptima de la anatomía relevante del hueso temporal.The ear is a complex anatomic structure. Its study and understanding represent a constant challenge for the radiologist. As a consequence the computed tomography becomes an essential tool for its examination. Conventional tomographic examination with both axial and coronal reconstruction of the image allows a satisfactory visualization of the different structures. However, the study requires long periods of time for its acquisition and uncomfortable or intolerable positions for the patients. Moreover, the characterization of some structures of the ear becomes limited. Sixty-four slice multidetector computed tomography allows the optimal study of the small and complex ear anatomy. Volumetric acquisitions with 0.5 mm slices, with multiplanar reconstructions in the three basic plans, in tri-dimensional reconstructions and curved plans, allow detailed visualization of structures in a few seconds, thuf avoiding patient discomfort. Our purpose in this article is to demonstrate the utility of reconstructions particularly in oblique planes, and reaching an optimal visualization of the temporal bone.

  8. Preoperative volume calculation of the hepatic venous draining areas with multi-detector row CT in adult living donor liver transplantation: impact on surgical procedure

    Frericks, Bernd B.J. [Hanover Medical School, Departments of Radiology and Surgery, Hannover (Germany); University of Berlin, Department of Radiology, Berlin (Germany); Charite - University Medicine Berlin, Department of Radiology and Nuclear Medicine, Berlin (Germany); Kirchhoff, Timm D.; Shin, Hoen-Oh; Stamm, Georg; Merkesdal, Sonja; Abe, Takehiko; Galanski, Michael [Hanover Medical School, Departments of Radiology and Surgery, Hannover (Germany); Hanover Medical School, Department of Diagnostic Radiology, Hannover (Germany); Schenk, Andrea; Peitgen, Heinz-Otto [Hanover Medical School, Departments of Radiology and Surgery, Hannover (Germany); MeVis - Center for Medical Diagnostic Systems and Visualization, Bremen (Germany); Klempnauer, Juergen [Hanover Medical School, Departments of Radiology and Surgery, Hannover (Germany); Hanover Medical School, Department of Visceral- and Transplantation Surgery, Hannover (Germany); Nashan, Bjoern [Hanover Medical School, Departments of Radiology and Surgery, Hannover (Germany); Hanover Medical School, Department of Visceral- and Transplantation Surgery, Hannover (Germany); Dalhousie University, Multi Organ Transplant Program, Halifax, Nova Scotia (Canada)

    2006-12-15

    The purpose was to assess the volumes of the different hepatic territories and especially the drainage of the right paramedian sector in adult living donor liver transplantation (ALDLT). CT was performed in 40 potential donors of whom 28 underwent partial living donation. Data sets of all potential donors were postprocessed using dedicated software for segmentation, volumetric analysis and visualization of liver territories. During an initial period, volumes and shapes of liver parts were calculated based on the individual portal venous perfusion areas. After partial hepatic congestion occurring in three grafts, drainage territories with special regard to MHV tributaries from the right paramedian sector, and the IRHV were calculated additionally. Results were visualized three-dimensionally and compared to the intraoperative findings. Calculated graft volumes based on hepatic venous drainage and graft weights correlated significantly (r=0.86,P<0.001). Mean virtual graft volume was 930 ml and drained as follows: RHV: 680 ml, IRHV: 170 ml (n=11); segment 5 MHV tributaries: 100 ml (n=16); segment 8 MHV tributaries: 110 ml (n=20). When present, the mean aberrant venous drainage fraction of the right liver lobe was 28%. The evaluated protocol allowed a reliable calculation of the hepatic venous draining areas and led to a change in the hepatic venous reconstruction strategy at our institution. (orig.)

  9. Effect of contrast injection protocol with dose tailored to patient weight and fixed injection duration on aortic and hepatic enhancement at multidetector-row helical CT

    The aim of this study was to investigate the effect of a contrast material injection protocol with dose and injection rate of contrast material tailored to patient weight (dose tailored to patient weight and fixed injection duration). Hepatic helical CT was performed in 92 patients with chronic liver damage with a dose of 1.4 ml (518 mgI) at a rate of 0.056 ml/s per kilogram body weight of Iopamidol 370. Attenuation values of liver and aorta were measured for calculation of maximum aortic and hepatic enhancement, time to maximum hepatic enhancement, and end of hepatic arterial phase. Correlation coefficients between the injection rate and the four parameters were r=0.008, 0.057, 0.167, and 0.036, and there were no statistically significant correlations between the injection rates and the four parameters. In our injection protocol, uniform temporal scan window may be achieved and the injection rate can be reduced in lighter patients without reducing the degree of enhancement in the aorta and the liver. (orig.)

  10. Clinical Application of 16 Row CT in the Diagnosis of Lumbar Disc Herniation%16排CT在腰椎间盘突出诊断中的临床应用价值

    徐廷忠

    2015-01-01

    Objective To explore the effect of clinical diagnosis of 16 slice CT in patients with lumbar disc protrusion.Methods 998 cases of lumbar disc herniation were selected from January 2012 to December 2014 in our hospital, carries on the 16 row CT diagnosis, and after operation and MBI examination confirmed the diagnosis coincidence rate, calculation, comparison and analysis.ResultsThe diagnosis of 998 patients, 252 cases of genera in the bulge type, 388 cases of protrusion type, 305 cases of prolapse of free type, 53 cases of schmorl with bone nodules and prominent, with surgery and MBI diagnosis of consistent with the results of 910 cases, the coincidence rate is 91.2%.Conclusion16 slice CT has better use value in the diagnosis of lumbar disc herniation patients.%目的:探讨16排CT对临床腰椎间盘突出患者的诊断效果。方法选取2012年1月~2014年12月期间来我院就诊的998例腰椎间盘突出患者为研究对象,对其进行16排CT诊断,并经过手术及MBI检查证实,计算该诊断的符合率,对比分析。结果经诊断,998例患者中,有252例属中膨隆型,388例突出型,305例脱垂游离型,53例Schmorl结节及经骨突出型,与手术和MBI诊断结果相符的有910例,相符率为91.2%。结论16排CT在腰椎间盘突出患者的诊断中具有较好的使用价值。

  11. CFD simulation of hemodynamics in sequential and individual coronary bypass grafts based on multislice CT scan datasets.

    Hajati, Omid; Zarrabi, Khalil; Karimi, Reza; Hajati, Azadeh

    2012-01-01

    There is still controversy over the differences in the patency rates of the sequential and individual coronary artery bypass grafting (CABG) techniques. The purpose of this paper was to non-invasively evaluate hemodynamic parameters using complete 3D computational fluid dynamics (CFD) simulations of the sequential and the individual methods based on the patient-specific data extracted from computed tomography (CT) angiography. For CFD analysis, the geometric model of coronary arteries was reconstructed using an ECG-gated 64-detector row CT. Modeling the sequential and individual bypass grafting, this study simulates the flow from the aorta to the occluded posterior descending artery (PDA) and the posterior left ventricle (PLV) vessel with six coronary branches based on the physiologically measured inlet flow as the boundary condition. The maximum calculated wall shear stress (WSS) in the sequential and the individual models were estimated to be 35.1 N/m(2) and 36.5 N/m(2), respectively. Compared to the individual bypass method, the sequential graft has shown a higher velocity at the proximal segment and lower spatial wall shear stress gradient (SWSSG) due to the flow splitting caused by the side-to-side anastomosis. Simulated results combined with its surgical benefits including the requirement of shorter vein length and fewer anastomoses advocate the sequential method as a more favorable CABG method. PMID:23365974

  12. Added diagnostic benefit of 16-row whole-body spiral CT in patients with multiple trauma differentiated by region and injury severity according to the ATLS {sup registered} concept; Diagnostischer Zugewinn der 16-Zeilen-Ganzkoerper-Spiral-CT bei polytraumatisierten Patienten differenziert nach Koerperregion und Verletzungsschwere gemaess ATLS {sup registered} -Konzept

    Maurer, M.H.; Knopke, S.; Schroeder, R.J. [Klinik fuer diagnostische und interventionelle Radiologie, Charite-Universitaetsmedizin Berlin (Germany)

    2008-12-15

    Purpose: to determine the added diagnostic benefit of using MS-CT in multiple trauma patients differentiated by severity of injury and affected body region. Materials and methods: a retrospective analysis was performed of the 16-row whole-body spiral CT findings in 275 multiple trauma patients (73% men, 27% women; age 39.6 {+-} 18.9 years) with regard to additional findings and new findings obtained with CT compared to the findings obtained by conventional projection radiography and abdominal ultrasound in the emergency room. The additional and new findings were differentiated by body region (head, face, chest, pelvis, abdomen, spine) and the degree of severity according to the three classes of injuries distinguished by the ATLS {sup registered} concept (class 1: simple injury, class 2: potentially life threatening, class 3: immediately life threatening). Results: a total of 921 additional findings (= findings potentially relevant for further diagnosis and therapy in addition to the findings obtained by conventional radiography or ultrasound) were obtained by MS-CT in all patients. The distribution by number of patients and body region was as follows: 22 neck, 76 face, 125 chest, 112 abdomen, 50 pelvis, and 91 spine. Most additional findings were categorized as potentially life threatening (ATLS class 2). In addition, there were 439 completely new findings, involving the head in 128 patients (mostly ATLS class 3), the face in 18, the chest in 47, the abdomen in 26, and the spine in 9 patients. Most new findings involving the face, abdomen, and spine were ATLS class 2 injuries. (orig.)

  13. 放松训练对320排动态容积CT冠状动脉成像的效果观察%Effect observation of relaxation training on imaging quality of 320-row dynamic volume CT coronary angiography

    耿跃然

    2012-01-01

    [Objective]To study the influence of relaxation training on imaging quality of 320-row dynamic volume CT coronary an-giography. [Methods] 100 patients who received the examination of coronary angiography were randomly divided into the relaxation training group and the control group. The control group was given the routine instruction before examination, and the relaxation training group was given the systemic relaxation training. The duration of heart rates control, duration of breath cooperation training, incidence of heart rates fluctuation over 10 times/min in the process of examination and success rate of examination of two groups were compared. [ Results ] The duration of heart rates control and duration of breath cooperation training of patients in the relaxation training group were shorted than those in the control group significantly (P < 0.01). The incidence of heart rates fluctuation over 10 times/min in the process of examination of the relaxation training group was lower than that of the control group, and the success rate of examination of the relaxation training group was higher than that of the control group. [ Conclusion ] The comprehensive relaxation training can effectively reduce the time consumption of heart rates control and breath cooperation training in patients who received the examination of 320-row dynamic volume CT coronary angiography, decrease the range of heart rates fluctuation in the process of examination, and significantly improve the imaging quality.%目的 探讨放松训练对320排动态容积CT冠状动脉成像的效果.方法 样本为100例进行冠状动脉成像造影检查的患者,随机分为疏导组和对照组.对照组检查前给予一般性造影检查指导,疏导组在检查前给予系统的放松训练,比较在行检查时两组患者心率控制速度、呼吸配合训练时间和检查过程心率波动>10次/min的发生率、检查成功率情况.结果 疏导组受检者心率控制速度及呼吸配

  14. 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

    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

  15. Rowing with FES

    Davoodi Rahman

    2008-01-01

    People with spinal cord injury (SCI) need to increase their level of physical activity to reduce the risk of cardiovascular disease but their exercise options are very limited. Functional electrical stimulation (FES) assisted indoor rowing has been developed as a total body exercise option that combines the exercise of the innervated upper body with the exercise of the electrically stimulated leg muscles in a natural manner. An existing indoor rowing machine was modified for use by the parapl...

  16. MR angiography and determination of the flow reserve after minimal invasive direct coronary artery bypass (MIDCAB) surgery of the left internal mammary arteria in comparison to the multidetector-row CT

    Purpose: To evaluate graft patency, flow and flow reserve in patients with minimal invasive direct coronary artery bypass (MIDCAB) of internal mammary artery (IMA) grafts using a combined MR protocol with phase-contrast technique and MR angiography. Material and methods: At a 1.5T Magnetom Sonata (SIEMENS), 19 symptomatic (angina CCS I-III, intermittent thoracic discomfort, scar disorders) patients (59.9±7.9 years old) with 19 left internal mammary artery (LIMA) grafts implanted in minimal invasive technique were examined 6.9±1.5 years post surgery. Contrast enhanced MR angiography (TR 2.5 ms, TE 1 ms, flip angle 20 , spatial resolution 1.4 x 0.9 x 1.0 mm3, breath hold technique, no ECG-triggering, 25 ml Gd-DTPA) was performed to assess bypass patency. Phase-contrast flow measurements with retrospective gating (TR 41 msec, TE 3.2 msec, flip angle 30 , spatial resolution 1.1 x 1.1 x 5 mm3, temporal resolution 42 msec, venc 90 cm/sec) were applied in the IMA grafts at rest and after stress induction with dipyridamole (0.56 mg/kg/BW). For comparison, graft patency was evaluated by multidetector-row computed tomography (16-row CT). In 9 patients a selective catheter angiography was performed. Results: MIDCAB grafts were occluded in 4/19 patients. In 4 patients the anastomosis to LAD was highly stenotic (>70%) at MDCT (2 experienced investigators in consensus reading). In MRA 9 grafts could be delineated completely including the distal anastomosis to LAD (47%). In 9 patients the distal part could not be evaluated. In patients with patent grafts (MDCT), a significant improvement of graft flow (at rest 75.4±33.3 ml/min; after stress 202.7±49.6; P<0.002) and flow reserve (patent grafts 3.0±1.1; stenotic grafts 1.5±0.2, P<0.02; occluded grafts 0.9±0.2, P<0.01) after stress induction was detected. Diastolic-to-systolic peak velocity ratios (D/S-PVR) at baseline were not significant between patent and stenotic grafts. Mean flow at baseline and after stress induction

  17. Rowing with FES

    Davoodi Rahman

    2008-01-01

    Full Text Available People with spinal cord injury (SCI need to increase their level of physical activity to reduce the risk of cardiovascular disease but their exercise options are very limited. Functional electrical stimulation (FES assisted indoor rowing has been developed as a total body exercise option that combines the exercise of the innervated upper body with the exercise of the electrically stimulated leg muscles in a natural manner. An existing indoor rowing machine was modified for use by the paraplegic users and two types of FES controllers were developed to control the level of stimulation to the paralyzed leg muscles. Manual FES controller was operated by the users thumb presses on the two control buttons on the handlebar, was easy to implement and operate, and has been the most widely used form of control in FES rowing. Automatic FES controllers produced rowing movement comparable to manual control strategy but did not require the user's thumb presses, could be used by the users with higher level of SCI, and could potentially be used to control more leg muscles to further increase the intensity and cardiovascular training effects of FES rowing exercise.

  18. Biomechanics of Rowing

    Hase, Kazunori; Andrews, Brian J.; Zavatsky, Amy B.; Halliday, Suzanne E.

    A new control model for the study of biomechanical simulation of human movement was investigated using rowing as an example. The objectives were to explore biological and mechanical alternatives to optimal control methods. The simulation methods included simple control mechanisms based on proportional and derivative (PD) control, consideration of a simple neural model, introduction of an inverse dynamics system for feedback, and computational adjustment of control parameters by using an evaluative criterion and optimization method. By using simulation, appropriate rowing motions were synthesized. The generated rowing motion was periodic, continuous, and adaptable so that the pattern was stable against the mechanical force and independent of the initial condition. We believe that the simulation model is not only practical as a computational research tool from a biomechanical-engineering viewpoint but also significant from the point of view of fundamental biological theories of movement.

  19. 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

    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

  20. Noise-based tube current reduction method with iterative reconstruction for reduction of radiation exposure in coronary CT angiography

    Purpose: To investigate the potential of noise-based tube current reduction method with iterative reconstruction to reduce radiation exposure while achieving consistent image quality in coronary CT angiography (CCTA). Materials and methods: 294 patients underwent CCTA on a 64-detector row CT equipped with iterative reconstruction. 102 patients with fixed tube current were assigned to Group 1, which was used to establish noise-based tube current modulation formulas, where tube current was modulated by the noise of test bolus image. 192 patients with noise-based tube current were randomly assigned to Group 2 and Group 3. Filtered back projection was applied for Group 2 and iterative reconstruction for Group 3. Qualitative image quality was assessed with a 5 point score. Image noise, signal intensity, volume CT dose index, and dose-length product were measured. Results: The noise-based tube current modulation formulas were established through regression analysis using image noise measurements in Group 1. Image noise was precisely maintained at the target value of 35.00 HU with small interquartile ranges for Group 2 (34.17–35.08 HU) and Group 3 (34.34–35.03 HU), while it was from 28.41 to 36.49 HU for Group 1. All images in the three groups were acceptable for diagnosis. A relative 14% and 41% reduction in effective dose for Group 2 and Group 3 were observed compared with Group 1. Conclusion: Adequate image quality could be maintained at a desired and consistent noise level with overall 14% dose reduction using noise-based tube current reduction method. The use of iterative reconstruction further achieved approximately 40% reduction in effective dose

  1. Rowing to Barbados

    Philpott, Andy; Leyland, Geoff

    2005-01-01

    In October 2003, sixteen boats set off from La Gomera in the Canary Islands headed for Barbados 4800 km distant. Each boat was manned by two oarsmen who were competing in the Transatlantic Challenge, an ocean rowing endurance event. This paper describes an optimization model developed for route planning in this event. It was used successfully by the Holiday Shoppe team to win the race in world record time. We describe the tool, its history, and the way it was used in the race.

  2. Rowing competitions and perspective

    Flores, Alfinio; Bernhardt, Stephen A.; Shipman, Henry L.

    2015-02-01

    This paper is about integrating the use of graphing technology (specifically, GeoGebra) with principles of motion, principles of perspective, and the concept of vanishing points to model a dynamic event. Students were asked to analyse video images of a rowing competition filmed with a single camera positioned perpendicular to the race. The fixed position of the camera in such races makes it difficult to determine whether a scull closer to the camera is actually overtaking another, more distant scull. The paper illustrates how students in their first year at the university can integrate the use of technology, science, mathematics, and writing to solve a real world problem involving motion.

  3. MR angiography and determination of the flow reserve after minimal invasive direct coronary artery bypass (MIDCAB) surgery of the left internal mammary arteria in comparison to the multidetector-row CT; MR-Angiographie und Flussreservenbestimmung nach minimalinvasiver direkter Koronararterien-Bypass(MIDCAB)-Operation der linken Arteria mammaria interna im Vergleich zur Mehrzeilen-CT

    Stauder, N.I.; Fenchel, M.; Kuettner, A.; Kramer, U.; Claussen, C.D.; Miller, S. [Abt. Radiologische Diagnostik, Universitaetsklinik Tuebingen (Germany); Stauder, H.; Scheule, A.M. [Abt. Thorax-, Herz- und Gefaesschirurgie, Universitaetsklinik Tuebingen (Germany)

    2005-08-01

    Purpose: To evaluate graft patency, flow and flow reserve in patients with minimal invasive direct coronary artery bypass (MIDCAB) of internal mammary artery (IMA) grafts using a combined MR protocol with phase-contrast technique and MR angiography. Material and methods: At a 1.5T Magnetom Sonata (SIEMENS), 19 symptomatic (angina CCS I-III, intermittent thoracic discomfort, scar disorders) patients (59.9{+-}7.9 years old) with 19 left internal mammary artery (LIMA) grafts implanted in minimal invasive technique were examined 6.9{+-}1.5 years post surgery. Contrast enhanced MR angiography (TR 2.5 ms, TE 1 ms, flip angle 20 , spatial resolution 1.4 x 0.9 x 1.0 mm{sup 3}, breath hold technique, no ECG-triggering, 25 ml Gd-DTPA) was performed to assess bypass patency. Phase-contrast flow measurements with retrospective gating (TR 41 msec, TE 3.2 msec, flip angle 30 , spatial resolution 1.1 x 1.1 x 5 mm{sup 3}, temporal resolution 42 msec, venc 90 cm/sec) were applied in the IMA grafts at rest and after stress induction with dipyridamole (0.56 mg/kg/BW). For comparison, graft patency was evaluated by multidetector-row computed tomography (16-row CT). In 9 patients a selective catheter angiography was performed. Results: MIDCAB grafts were occluded in 4/19 patients. In 4 patients the anastomosis to LAD was highly stenotic (>70%) at MDCT (2 experienced investigators in consensus reading). In MRA 9 grafts could be delineated completely including the distal anastomosis to LAD (47%). In 9 patients the distal part could not be evaluated. In patients with patent grafts (MDCT), a significant improvement of graft flow (at rest 75.4{+-}33.3 ml/min; after stress 202.7{+-}49.6; P<0.002) and flow reserve (patent grafts 3.0{+-}1.1; stenotic grafts 1.5{+-}0.2, P<0.02; occluded grafts 0.9{+-}0.2, P<0.01) after stress induction was detected. Diastolic-to-systolic peak velocity ratios (D/S-PVR) at baseline were not significant between patent and stenotic grafts. Mean flow at baseline and

  4. CT enteroclysis in the diagnostics of small bowel diseases

    Background: The role of CT enteroclysis is gaining on importance in the diagnostics of small bowel diseases. The aim of the study was to present own experiences in CT enteroclysis application, with the use of a 64-detector CT unit. Material/Methods: CT enteroclyses were performed in 60 patients: 53 with the suspicion of the Crohns disease, 2 suspected for carcinoid, 1 with suspicion of the fistula between the small bowel and the bladder, 2 suspected for the tumor of the ileo-caecal region, and in 1 case, the aim of examination was to carry out an evaluation of the postsurgical state of the bowel-bowel anastomosis. We used own endoscopic technique of catheter insertion into the bowel, which shortens the examination time and improves patients comfort. Results: The catheter was correctly introduced into the small bowel in 58 patients (endoscopy had to be repeated in 4 cases). Only 2 examinations failed, because patients refused repeated endoscopy. Radiological signs of the Crohns disease were found in 50 out of 53 patients. In the 3 remaining patients, the appearance of the small bowel was normal. In 5 non-Crohns disease patients, CT enteroclysis enabled a good visualization of the pathology (tumors, fistula). Conclusions: CT enteroclysis with the use of the 64-detector CT unit is a valuable method in the diagnostics of small bowel diseases. It could supplement or precede capsule endoscopy. (authors)

  5. Training Rowing with Virtual Environments

    Gopher Daniel; Korman Maria; Hoffmann Charles; Varlet Manuel; Marin Ludovic; Bardy Benoît; Filippeschi Alessandro; Ruffaldi Emanuele; Bergamasco Massimo

    2011-01-01

    This paper presents the results of the design, implementation and evaluation of a platform for rowing training in Virtual Reality called SPRINT. The paper discusses how various aspects of the rowing skill can be analyzed and trained over a single common methodology and system platform. The result is a vision for new directions in the domain of sport training with Virtual Reality.

  6. 颞骨64排CT低剂量扫描及不同重建函数对图像质量的影响%Effects of Different Function Convolution on Image Quality in Low-dose 64-Detector Computed Tomography of Petrous Bone

    关丽明; 李祥胜; 李松柏; 徐克

    2011-01-01

    目的 旨在评价不同重建函数的低剂量64排CT的颞骨图像质量.方法 选取临床怀疑颞骨病变而来放射科行64排CT检查的患者63例并随机分为2组:重建函数为FC30组和FC81组,均以30 mA管电流进行扫描,其他扫描条件固定.双盲法测量各组重建图像的噪声、评价图像质量及各解剖结构的显示情况并进行统计学分析.结果 随着管电流量的降低,各组图像噪声均增加.同一重建函数的轴位图像噪声大于冠状位图像噪声,FC30图像噪声低于FC81噪声,各组内以及组间差异具有统计学意义(P0.05).结论 颞骨采用64排CT低剂量扫描后图像噪声增加,且重建函数和重建方向对图像噪声影响较大,但是图像质量和各解剖结构的显示能够满足诊断要求.%Objective To evaluate the image quality of the petrous bone using low-dose scams of 64-detector computer tomography with different function convolution (FC). Methods Totally 63 cases of the petrous bone examined by Toshiba Aquilion 64-detector CT were collected and divided into 2 groups ( FC30 and FC81 ) randomly. Other scan parameters were fixed. The image noises and quality as well as the visualization of anatomical landmarks of the petrous bone were evaluated by two advanced radiologists with double-blind method.Results Following the reduction of the tube current, the image noise increased in both groups. There were significant statistical differences of image noise not only between the axial images and coronal images of the same FC but also the images of different FC ( P < 0.05 ).Moreover, there were no statistical difference in the scores of image and anatomical landmarks between the two groups ( P > 0.05 ). Conclusion The use of low-current protocol resulted in a significant increase in the image noise in petrous bone CT, which was also affected by FC, with the satisfied diagnostic results.

  7. Hemobilia in a child due to right hepatic artery pseudoaneurysm: Multidetector-row computed tomography demonstration

    Nisar A Wani

    2011-01-01

    Full Text Available We present a case of a 12-year-old boy who developed upper gastrointestinal bleeding in the form of hematemesis and melena 1 month after blunt trauma to liver. Computed tomography (CT angiography with multidetector-row CT demonstrated pseudoaneurysm of right hepatic artery related to old liver laceration to be the cause of the bleeding. Pseudoaneurysm was resected using the roadmap provided by CT angiography findings.

  8. Training Rowing with Virtual Environments

    Gopher Daniel

    2011-12-01

    Full Text Available This paper presents the results of the design, implementation and evaluation of a platform for rowing training in Virtual Reality called SPRINT. The paper discusses how various aspects of the rowing skill can be analyzed and trained over a single common methodology and system platform. The result is a vision for new directions in the domain of sport training with Virtual Reality.

  9. Twin Row Conservation Tillage Corn Production

    Corn (Zea mays L.) seeded in narrow row patterns can increase yields and accelerate canopy closure; however, costly equipment modifications make narrow rows impractical. Twin row patterns are a compromise to enhance the benefit of narrow rows with fewer equipment modifications. We compared yield, ...

  10. 320-row CT coronary angiography predicts freedom from revascularisation and acts as a gatekeeper to defer invasive angiography in stable coronary artery disease: a fractional flow reserve-correlated study

    To determine the accuracy of 320-row multidetector coronary computed tomography angiography (M320-CCTA) to detect functional stenoses using fractional flow reserve (FFR) as the reference standard and to predict revascularisation in stable coronary artery disease. One hundred and fifteen patients (230 vessels) underwent M320-CCTA and FFR assessment and were followed for 18 months. Diameter stenosis on invasive angiography (ICA) and M320-CCTA were assessed by consensus by two observers and significant stenosis was defined as ≥50 %. FFR ≤0.8 indicated functionally significant stenoses. M320-CCTA had 94 % sensitivity and 94 % negative predictive value (NPV) for FFR ≤0.8. Overall accuracy was 70 %, specificity 54 % and positive predictive value 65 %. On receiver operating characteristic (ROC) curve analysis, the area under the curve (AUC) for CCTA to predict FFR ≤0.8 was 0.74 which was comparable with ICA. The absence of a significant stenosis on M320-CCTA was associated with a 6 % revascularisation rate. M320-CCTA predicted revascularisation with an AUC of 0.71 which was comparable with ICA. M320-CCTA has excellent sensitivity and NPV for functional stenoses and therefore may act as an effective gatekeeper to defer ICA and revascularisation. Like ICA, M320-CCTA lacks specificity for functional stenoses and only has moderate accuracy to predict the need for revascularisation. (orig.)

  11. Using Multidetector Row Computed Tomography to Diagnose and Stage Pancreatic Carcinoma: the Problems and the Possibilities

    Rotondo A

    2005-01-01

    Full Text Available The sensitivity of computed tomography (CT in the diagnosis of pancreatic neoplasms and accurate tumor staging has significantly been improved by the use of thin-section multi-detector row CT techniques. Greater table speed, improved tube cooling, high resolution imaging and the possibility of isotropic voxels have led to optimal multiplanar reconstruction in any arbitrary plane and particularly along the pancreatic duct and peripancreatic vessels, significantly improving the detection of small pancreatic tumors and surgical resectability where imaging modalities have so far yielded disappointing results. Nonetheless, while multi-detector row CT has greatly enhanced the imaging capabilities of CT, early diagnosis is practically impossible to achieve, since the tumor remains asymptomatic until the surrounding structures are involved. Furthermore, even when treated with radical surgery, the incidence of recurrence is high and the prognosis of pancreatic carcinoma still remains extremely poor and has not changed over the past years. In this article, the recent technical developments of multi-detector row CT in diagnosing pancreatic neoplasms and staging are considered, with special emphasis on multi-detector row CT angiography techniques and curved planar reformations. Some remaining challenging problems such as the pre-operative identification and characterization of small hepatic lesions and detection of omental and peritoneal metastasis, the diagnosis of small isoattenuating pancreatic adenocarcinomas and promising strategies to differentiate between pancreatic adenocarcinoma and chronic inflammatory changes are also presented.

  12. Comparison between multi-detector row CT angiography and Doppler ultrasound on detecting carotid artery wall thickness%多层螺旋CT与Doppler超声对颈动脉壁层厚度的对比性研究

    赵刚; 查云飞; 王弘; 洪玮; 邱晓明; 王珍; 肖友梅

    2013-01-01

    Objective To explore the relationship and consistency between multi-detector row computed tomography angiography (MDCTA) and color Doppler ultrasound (CD-US) in measuring carotid artery wall thickness (CAWT) and intima-media thickness (IMT). Methods CAWT and IMT of 38 subjects were measured using MDCTA and CD-US, respectively. Linear correlation analysis was performed to analyze the correlation between the results from CAWT and IMT,and Bland-Altman statistics was employed to analyze the consistency between them. Results The IMT value measured by CD-US was (0.85+0.16) mm, and the CAWT value measured by MDCTA was (0.87.± 0.18) mm (P > 0.05), and there was a high degree of correlation between them (correlation coefficient was 0.958,P< 0.01). An excellent consistency between CAWT and IMT was found by Bland-Altman plot, with a bias of 0.026 mm and the limit of consistency from -0.023 to 0.075. Conclusions There were significant correlation and consistency between MDCTA and CD-US in detecting CAWT and IMT. As a more objective and comprehensive new method, MDCTA can replace CD-US in the evaluation of early carotid atherosclerosis.%目的:探讨多层螺旋CT血管造影(MDCTA)和彩色多普勒超声(CD-US)在检测颈总动脉壁厚度(CAWT)和颈总动脉内膜-中层厚度(IMT)中的相关性和一致性.方法:应用MDCTA和CD-US分别对38例受试者颈总动脉的CAWT和IMT进行检测,用Pearson直线相关分析比较CAWT和IMT的相关性,用Bland-Altman分析比较两者的一致性.结果:MDCTA测量的颈总动脉CAWT为(0.87±0.18)mm,CD-US测量的颈总动脉IMT为(0.85±0.16)mm,两者比较无统计学差异,有高度相关性,相关系数为0.958,P<0.01,Bland-Altman分析两者间存在良好一致性,偏倚为0.026 mm,一致性界限为-0.023 ~ 0.075.结论:MDCTA和CD-US在检测颈总动脉CAWT和IMT时存在良好的相关性和一致性,MDCTA可以替代CD-US,作为一种评价颈动脉早期粥样硬化的更加客观全面的新方法.

  13. Detection of hypervascular malignant foci in borderline lesions of hepatocellular carcinoma: comparison of dynamic multi-detector row CT, dynamic MR imaging and superparamagnetic iron oxide-enhanced MR imaging

    The study object was to retrospectively compare the detection rate of hypervascular foci visualized by CT during hepatic arteriography (CTHA) in borderline nodules, which was observed upon cirrhotic livers, on dynamic MDCT, dynamic gadolinium-enhanced MR (dynamic MR), and SPIO-enhanced MR imaging. Eighty-five nodules in 49 patients with cirrhosis were evaluated. When a part of the nodule showed hyperdensity relative to the surrounding areas of the nodule on CTHA, it was defined as ''hypervascular focus.'' The relationships between the dynamic MDCT and dynamic MR and SPIO-enhanced MR imaging findings of these foci were analyzed using X2 test. Hypervascular foci were detected in 17 (53%) of 32 on the arterial dominant phase of dynamic MDCT, in 19 (37%) of 51 on the arterial dominant phase of dynamic MR and in 6 (26%) of 23 on SPIO-enhanced MR imaging. Arterial dominant phase of dynamic MDCT demonstrated a significantly higher detection rate of hypervascular foci less than 5 mm in diameter than did dynamic and SPIO MR imaging (p<0.05). Hypervascular foci in borderline nodules could be better visualized by dynamic MDCT than by gadolinium- and SPIO-enhanced MR imaging. Dynamic MDCT is recommended for the follow-up examination of hypovascular borderline lesions. (orig.)

  14. Rowing faster by surface treatment

    Greidanus, A.J.; Delfos, R.; Westerweel, J.

    2012-01-01

    The largest part of hydrodynamic drag during rowing, sailing or canoeing is the turbulent skin friction (80-90%). Higher velocities can be achieved by reducing the friction drag as a result of surface treatment. This research focuses on the development, characterization, and testing of drag-reducing

  15. Bilateral Second Carpal Row Duplication Associated with Multiple Epiphyseal Dysplasia.

    Cladiere-Nassif, Victoire; Delaroche, Caroline; Pottier, Edwige; Feron, Jean-Marc

    2015-11-01

    We report a case of a 75-year-old woman presenting a hitherto undescribed condition of bilateral second carpal row duplication. She was diagnosed in childhood with both Marfan and Ehlers-Danlos syndromes, with no clear evidence and no further medical follow-up. She presented throughout her life with various articular symptoms, which appeared to be compatible with a diagnosis of multiple epiphyseal dysplasia, and underwent several surgical procedures on her knees and hips. Most recently, she was reporting pain at the base of the fifth metacarpal bone of the left hand. X-ray images and computed tomography (CT) were obtained for exploration and showed a total second row duplication in both carpi, with a total number of 18 carpal bones in each wrist. PMID:26649258

  16. Economic impact World Rowing Championships 2014

    Faille Deutekom, Marije de la; Verhoogt, Pieter

    2014-01-01

    Economische impact World Rowing Championships 2014 Van 24 tot 31 augustus 2014 vond op de Bosbaan in Amsterdam de World Rowing Championships (WRC) plaats. Met het oog op de verdere ontwikkeling van het evenement wil de World Rowing Federation (FISA inzicht krijgen in de economische impact van dit ev

  17. A New Submaximal Rowing Test to Predict 2,000-m Rowing Ergometer Performance

    Otter, Ruby T. A.; Brink, Michel S.; Lamberts, Robert P.; Lemmink, Koen A. P. M.

    2015-01-01

    Otter, RTA, Brink, MS, Lamberts, RP, and Lemmink, KAPM. A new submaximal rowing test to predict 2,000-m rowing ergometer performance. J Strength Cond Res 29(9): 2426-2433, 2015-The purpose of this study was to assess predictive value of a new submaximal rowing test (SmRT) on 2,000-m ergometer rowing

  18. Three - dimensional Study of the Bronchial Tree on Multiple Detector - row Spiral CT: Evaluation of Imaging Protocols%支气管树的多排螺旋CT三维研究

    强金伟; 周康荣; 廖治河; 鲁刚; 陈刚; 陈锦

    2005-01-01

    目的评价多排螺旋CT(MDSCT)三维重建显示段以下中小气道的能力.方法20例健康志愿者行准直1 mm,Pitch 1.75的螺旋高分辨率扫描,分别用标准(Filter B)和高滤过重建算法(Filter D)重建横断面图像,间隔0.6 mm.其中10例同时做增强扫描.16个新鲜肺叶充气标本,用3组方案扫描,准直分别为0.5 mm、1.0 mm和2.5 mm,Pitch 1.75,Filter D重建,间隔相应为0.3 mm、0.6 mm和1.3 mm.用种子技术行支气管表面遮盖显示(SSD)重建,比较平扫与增强、不同滤过算法和不同层厚显示支气管的等级和长度.结果在活体,采用平扫重建的SSD图像优于增强,用Filter D重建的SSD图像优于Filter B,其中以平扫Filter D图像所做SSD最佳,能显示99.8%的4级、大部分5级及部分6级支气管.在肺标本,0.5 mm组显示5~8级支气管明显优于1.0 mm和2.5 mm组,能显示全部7级和部分8级支气管.结论采用MDSCT、0.5~1.0 mm准直的高分辨率扫描后行SSD重建能从平面和立体直观地显示4~7级支气管,评价该范围内的支气管病变.

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

    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

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

    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.

  1. Ergometer rowing with and without slides

    Larsen, Anders Holsgaard; Jensen, K

    2010-01-01

    A rowing ergometer can be placed on a slide to imitate 'on-water' rowing. The present study examines I) possible differences in biomechanical and physiological variables of ergometer rowing with and without slides and II) potential consequences on training load during exercise. 7 elite oars......-women rowed in a randomized order in a slide or stationary ergometer at 3 predefined submaximal and at maximal intensity. Oxygen uptake was measured and biomechanical variables of the rowing were calculated based upon handle force (force transducer) and velocity/length (potentiometer) of the stroke. Stroke...

  2. Autoand heterosuggestion in boat rowing

    Omelyanenko V.I.

    2013-12-01

    Full Text Available Purpose. Creation of a complex integrated person-centered psychological model of sportsmen preparation for competitions in rowing and canoeing on base of geterosuggestion which includes psychological methods and their modifications as well as Rajah yoga system mindset trainings. Material, methods. In research took part 20 sportsmen in boat rowing of 1st juinor category aged 15 and 16 years old with parental consent. Different variants of combinations of psychological techniques developed psychotherapist with the participation of the team's coach, taking into account specific situations arising for each athlete individually. Results. Found that the experimental group was superior to the competition in scoring control group. Correction rowing technique was observed within 1-3 sessions. An efficiency of use of the developed model in the psychological preparation of rowers. Successfully carried out programming, simulation , correction of motor skills and psycho-emotional state of athletes in training and competitive periods. Conclusions. Stability of high sports results observed on the background of the post-hypnotic suggestion and formed a positive psycho-emotional and motivational attitude. The advantage over geterosuggestion under autosuggestion.

  3. Vascular air embolism after contrast administration on 64 row multiple detector computed tomography: A prospective analysis

    Kushaljit S Sodhi

    2015-01-01

    Full Text Available Background: Vascular air embolism is being progressively reported as a nonfatal event with increase in use of computed tomography (CT as a diagnostic modality. This study was undertaken to study the frequency and site of vascular air embolism in patients undergoing contrast-enhanced CT (CECT and analyze CT parameters that influence its prevalence and final outcome. Materials and Methods: This was a prospective study approved by departmental ethics committee. Presence and location of air emboli in 200 patients who underwent CT scan of chest on a 64 detector scanner was recorded. We analyzed the role of various factors that could influence the prevalence of air embolism after injection of contrast in CECT scans. These factors included the amount of contrast injected, rate of flow of injection of contrast, site of injection of contrast, and size of intravenous access line. Results: Iatrogenic vascular air emboli were seen in 14 patients (7% of total. The locations of air emboli were main pulmonary artery in 12 (6% of total, left brachiocephalic vein in 3 (1.5% of total, right atrial appendage in 4 (2% of total, and superior vena cava (SVC in 1 (0.5% patient. There was no association between volume of contrast, flow rate, site and size of intravenous access, and presence of air emboli. Conclusion: Radiologists as well as referring physicians should be aware of vascular air embolism, which can occur after contrast injection in patients undergoing CT scan. Age, volume of contrast, flow rate of pressure injector, and site and size of venous cannula do not influence the likelihood or incidence of detection of venous air emboli on CT scans.

  4. Detection and classification of different liver lesions: Comparison of Gd-EOB-DTPA-enhanced MRI versus multiphasic spiral CT in a clinical single centre investigation

    Böttcher, Joachim [Institute of Diagnostic and Interventional Radiology, SRH Clinic Gera, Str. des Friedens 122, 07548 Gera (Germany); Hansch, Andreas [Institute of Diagnostic and Interventional Radiology, Friedrich-Schiller-University, Jena University Hospital, Erlanger Allee 101, 07740 Jena (Germany); Pfeil, Alexander [Department of Internal Medicine III, Friedrich-Schiller-University, Jena University Hospital, Erlanger Allee 101, 07740 Jena (Germany); Schmidt, Peter [Institute of Diagnostic and Interventional Radiology, Friedrich-Schiller-University, Jena University Hospital, Erlanger Allee 101, 07740 Jena (Germany); Malich, Ansgar [Institute of Diagnostic Radiology, Suedharz Clinic Nordhausen, Dr. Robert-Koch-Str. 39, 99734 Nordhausen (Germany); Schneeweiss, Albrecht [Institute of Diagnostic and Interventional Radiology, Friedrich-Schiller-University, Jena University Hospital, Erlanger Allee 101, 07740 Jena (Germany); Maurer, Martin H.; Streitparth, Florian [Department of Radiology, Charité University Medicine Berlin, Campus Virchow Clinic, Augustenburger Platz 1, 13353 Berlin (Germany); Teichgräber, Ulf K. [Institute of Diagnostic and Interventional Radiology, Friedrich-Schiller-University, Jena University Hospital, Erlanger Allee 101, 07740 Jena (Germany); Renz, Diane M., E-mail: diane.renz@charite.de [Department of Radiology, Charité University Medicine Berlin, Campus Virchow Clinic, Augustenburger Platz 1, 13353 Berlin (Germany)

    2013-11-01

    Objective: To compare the diagnostic efficacy of Gd-EOB-DTPA-enhanced magnetic resonance imaging (MRI) vs. multidetector computed tomography (MDCT) for the detection and classification of focal liver lesions, differentiated also for lesion entity and size; a separate analysis of pre- and postcontrast images as well as T2-weighted MRI sequences of focal and exclusively solid lesions was integrated. Methods: Twenty-nine patients with 130 focal liver lesions underwent MDCT (64-detector-row; contrast medium iopromide; native, arterial, portalvenous, venous phase) and MRI (1.5-T; dynamic and tissue-specific phase 20 min after application of Gd-EOB-DTPA). Hepatic lesions were verified against a standard of reference (SOR). CT and MR images were independently analysed by four blinded radiologists on an ordinal 6-point-scale, determining lesion classification and diagnostic confidence. Results: Among 130 lesions, 68 were classified as malignant and 62 as benign by SOR. The detection of malignant and benign lesions differed significantly between combined and postcontrast MRI vs. MDCT; overall detection rate was 91.5% for combined MRI and 80.4% for combined MDCT (p < 0.05). Considering all four readers together, combined MDCT achieved sensitivity of 66.2%, specificity of 79.0%, and diagnostic accuracy of 72.3%; combined MRI reached superior diagnostic efficacy: sensitivity 86.8%, specificity 94.4%, accuracy 90.4% (p < 0.05). Differentiated for lesion size, in particular lesions <20 mm revealed diagnostic benefit by MRI. Postcontrast MRI also achieved higher overall sensitivity, specificity, and accuracy compared to postcontrast MDCT for focal and exclusively solid liver lesions (p < 0.05). Conclusion: Combined and postcontrast Gd-EOB-DTPA-enhanced MRI provided significantly higher overall detection rate and diagnostic accuracy, including low inter-observer variability, compared to MDCT in a single centre study.

  5. Detection of hypervascular hepatocellular carcinoma: Comparison of multi-detector CT with digital subtraction angiography and Lipiodol CT

    Zheng, Xiao-Hua; Guan, Yong-Song; Zhou, Xiang-Ping; Huang, Juan; Sun, Long; Li, Xiao; Liu, Yuan

    2005-01-01

    AIM: The purpose of this study was to compare the diagnostic accuracy of biphasic multi-detector row helical computed tomography (MDCT), digital subtraction angiography (DSA) and Lipiodol computed tomography (CT) in detection of hypervascular hepatocellular carcinoma (HCC).

  6. 320排动态容积CT冠状动脉成像在川崎病冠状动脉瘤远期随访中应用%Application of 320-detector row dynamic volume CT angiography in follow up of coronary artery aneurysms caused by Kawasaki disease

    刘俊; 于明华; 许开元; 向峰; 周乾潮

    2015-01-01

    ObjectiveTo assess the values of 320-detector row dynamic volume CT angiography (CTA) and transthoracic echocardiography (TTE) in follow up of coronary artery aneurysm (CAA) caused by Kawasaki disease (KD).Methods320-de-tector row CTA and TTE were applied in long-term follow-up of 8 patients with CAA caused by KD.ResultsIn 8 patients, the mean age at onset was 41.63±22.70 months and the mean follow up time was 43.50±10.99 months. In acute phase, 3 cases of giant coronary artery aneurysms (GCAA) and 5 cases of mid-small CAA were diagnosed by TTE. A total of 16/32 arteries (50%) were involved. At the end of follow-up, 3 cases of GCAA and 2 cases of mid-small CAA were still diagnosed by TTE, and small CAAs were regressed in another 3 cases. A total of 6/32 arteries (18.75%) were involved. Simultaneously at the end of follow-up, a total of 7/32 arteries (21.9%) were involved by 320-detector row CTA. The distribution was consistent with that of TTE. Mean-while, there were one case of left circumlfex artery, one case of GCAA at distal of the right coronary artery, 2 cases of thrombus, 1 case of coronary stenosis and 2 cases of calciifcation.ConclusionsCAA caused by KD may be persistent for a long time. The thrombus, stenosis, and calciifcation of coronary can occurr at late phase in GCAA. TTE is sensitive and reliable to detect proxi-mal and middle segment of coronary lesions, but has limitations in detection of distal segment of coronary arteries. 320-detector row CTA has more comprehensively view of each coronary artery lesions and is especially sensitive and reliable to detect coro-nary thrombosis, calciifcation and narrowing in proximal and distal coronary arteries after acute phase.%目的:探讨320排动态容积CT冠状动脉成像(CTA)及经胸超声心动图(TTE)对川崎病(KD)合并冠状动脉瘤(CAA)中远期随访的应用价值。方法采用320排CTA、TTE进行中远期追踪随访8例KD合并CAA患儿。结果8例患儿平均发病年龄(41.63±22

  7. 320排动态容积CT冠状动脉成像在川崎病冠状动脉瘤远期随访中应用%Application of 320-detector row dynamic volume CT angiography in follow up of coronary artery aneurysms caused by Kawasaki disease

    刘俊; 于明华; 许开元; 向峰; 周乾潮

    2015-01-01

    目的:探讨320排动态容积CT冠状动脉成像(CTA)及经胸超声心动图(TTE)对川崎病(KD)合并冠状动脉瘤(CAA)中远期随访的应用价值。方法采用320排CTA、TTE进行中远期追踪随访8例KD合并CAA患儿。结果8例患儿平均发病年龄(41.63±22.70)月,随访时间(43.50±10.99)月。急性期TTE诊断冠状动脉巨大瘤(GCAA)3例,中小瘤5例,共累及冠状动脉16/32支(50.0%)。随访观察终点时TTE示GCAA 3例及中小瘤2例仍存在,另3例小瘤消退,仍累及冠状动脉6/32支(18.6%)。随访观察终点时320排CTA检查示累及冠状动脉7/32支(21.9%),分布部位与TTE基本一致;另发现左回旋支扩张1例,右冠状动脉(RCA)远段GCAA 1处、血栓2处、狭窄1处、钙化2处。结论KD引起的CAA可长期存在, GCAA后期可发生冠状动脉血栓、狭窄或钙化。TTE观察近中段冠脉改变敏感可靠,但对于中远段冠脉损害的观察有局限性。320排CTA能较全面地观察各支冠状动脉的病变,尤其对急性期后冠状动脉血栓,钙化及近、远端狭窄的观察敏感可靠。%ObjectiveTo assess the values of 320-detector row dynamic volume CT angiography (CTA) and transthoracic echocardiography (TTE) in follow up of coronary artery aneurysm (CAA) caused by Kawasaki disease (KD).Methods320-de-tector row CTA and TTE were applied in long-term follow-up of 8 patients with CAA caused by KD.ResultsIn 8 patients, the mean age at onset was 41.63±22.70 months and the mean follow up time was 43.50±10.99 months. In acute phase, 3 cases of giant coronary artery aneurysms (GCAA) and 5 cases of mid-small CAA were diagnosed by TTE. A total of 16/32 arteries (50%) were involved. At the end of follow-up, 3 cases of GCAA and 2 cases of mid-small CAA were still diagnosed by TTE, and small CAAs were regressed in another 3 cases. A total of 6/32 arteries (18.75%) were involved. Simultaneously at the end of follow-up, a total of 7/32 arteries (21

  8. Economic impact World Rowing Championships 2014

    Faille Deutekom, Marije de la; Verhoogt, Pieter

    2014-01-01

    Economische impact World Rowing Championships 2014 Van 24 tot 31 augustus 2014 vond op de Bosbaan in Amsterdam de World Rowing Championships (WRC) plaats. Met het oog op de verdere ontwikkeling van het evenement wil de World Rowing Federation (FISA inzicht krijgen in de economische impact van dit evenement. Zij heeft de Hogeschool van Amsterdam in samenwerking met Hogeschool Inholland en Sport2B gevraagd hier onderzoek naar te doen. Daarnaast heeft de FISA enkele aanvullende vragen geformulee...

  9. Mechanical performance of aquatic rowing and flying.

    Walker, J.A.; Westneat, M. W.

    2000-01-01

    Aquatic flight, performed by rowing or flapping fins, wings or limbs, is a primary locomotor mechanism for many animals. We used a computer simulation to compare the mechanical performance of rowing and flapping appendages across a range of speeds. Flapping appendages proved to be more mechanically efficient than rowing appendages at all swimming speeds, suggesting that animals that frequently engage in locomotor behaviours that require energy conservation should employ a flapping stroke. The...

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

    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 TM64 (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)

  11. : Light Interception in Single Row, Twin Row, and Diamond Planting Patterns of Valencia Peanut

    A field study was conducted on a growers farm South of Clovis, NM in 2006 to compare light interception and radiation use efficiency in single row, twin row, and diamond planted Valencia peanuts with line quantum sensors (Apogee instruments, Logan) installed across the crop row. Data were recorded ...

  12. YIELD AND GRADE OF VALENCIA PEANUT IN SINGLE ROW, TWIN ROW, AND DIAMOND PLANTING PATTERNS

    A study was conducted at Wayne Baker’s farm South of Clovis in 2006 to compare single row, twin row, and diamond planting patterns in Valencia peanut on 36 inch beds. The twin row and diamond pattern treatments were planted with an experimental planter developed at the USDA-ARS National Peanut Rese...

  13. Multidetector CT imaging of mechanical prosthetic heart valves: quantification of artifacts with a pulsatile in-vitro model

    Symersky, P.; Budde, R. P. J.; Westers, P.; Mol, de, B.A.J.M.; Prokop, M

    2011-01-01

    Objectives Multidetector computed tomography (MDCT) can detect the cause of prosthetic heart valve (PHV) dysfunction but is hampered by valve-induced artifacts. We quantified artifacts of four PHV using a pulsatile in-vitro model and assessed the relation to leaflet motion and valve design. Methods A Medtronic Hall tilting disc (MH), and Carbomedics (CM), St Jude (SJM), and ON-X bileaflet valves underwent CT in an in-vitro model using retrospective gating with a 64 detector CT system in stati...

  14. Rows=Wildlife Corridors: An Urban Resource.

    Young, Darrell D.

    1983-01-01

    Linear strips of land associated with highways, electrical transmission lines, gas/oil pipelines (called right-of-way or ROWs) are inhibited by a variety of wildlife and offer a unique opportunity to study the wildlife in the urban setting. Types of wildlife found in and importance of ROWs are discussed. (JN)

  15. Rasch models with exchangeable rows and columns

    Lauritzen, Steffen Lilholt

    The article studies distributions of doubly infinite binary matrices with exchangeable rows and columns which satify the further property that the probability of any $m \\times n$ submatrix is a function of the row- and column sums of that matrix. We show that any such distribution is a (unique...

  16. CT findings in Crohn's disease

    Objective: To evaluate the CT features and the role of CT in the diagnosis of Crohn's disease. Methods: CT manifestations of 18 patients with pathology confirmed Crohn's disease were retrospectively analyzed. The majority of the patients were scanned with spiral CT or multidetector row CT. Results: All 18 patients, segmental thickening of the bowel wall was detected. There were two different appearances in contrast-enhanced CT scans: (1) mural thickening without enhancement or mural stratification, and homogeneous attenuation in the thickened wall were observed in 7 patients; (2) mural thickening and stratification, resulting in the target or double-halo appearance, were detected in 11 patients, and the bowel wall thickening ranged from 5 to 10 mm. Nine patients had perienteric abnormalities including fibrofatty proliferation, phlegmon and mesenteric hypervascularity. According to the CT manifestations, 5 patients were initially diagnosed as other diseases including intestinal obstruction (1 case), tuberculosis (1 case), cancer (2 cases), and abscess (1 case), respectively. Conclusion: CT has the unparalleled ability to depict the abnormalities in the bowel wall, mesentery, abdominal and pelvic viscera, and contrast- enhanced CT can distinguish active Crohn's disease from quiescent Crohn's disease. These features make CT particularly valuable in the management of Crohn's disease. (authors)

  17. Colin Rowe and ' Dynamic Equilibrium'

    Pablo López Marín

    2015-05-01

    Full Text Available AbstractIn 1944 Gyorgy Kepes published what undoubtless will be his most influential text, "The language of vision". What Kepes tried to do was a guide of grammar and syntax of vision, which allows to face art as purely sensory experience or just visual, devisted of any literary , semantic or sentimental meaning.Among all the concepts that Kepes developes in his essay perhaps the most decisive one is the so called dynamic equilibrium, which is introduced in this work for fi rst time, verbalizing something that was in the air, orbiting around the entire modern plastic but far only explained in an empirical way.Colin Rowe reverberates the recent readed kepesian ideas on his own writings Transparency: Literal and Phenomenal and Neo-'Classicism' and Modern Architecture I and II, when the author tries to highlight the founding principles of the modern movement refusing the plastic  dimension of the discipline . The article will try to expose and explain this influence.

  18. Subsecond spiral CT: new developments

    X-ray computerized tomography (CT) scanning with continuous patient transport has been established under the name spiral CT since several years as the standard clinical examination procedure. Presently this technique is being improved dramatically with respect to scan speed, temporal response and z-axis resolution. This is achieved by the use of latest technical developments: rotation speed up to 2 s-1 and multi-row detector array systems. Today detector systems with M = 4 simultaneously measured slices are available. We report about recent investigations on new algorithms that are based on multi-slice spiral data. It is shown that the new technology not only provides significant reduction in overall scan times and thereby of the CT scanner's X-ray tube load; beyond that, the new technology makes CT imaging of the beating heart with high level image quality feasible in standard clinical routine. (author)

  19. A concept of row crater enhancement

    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

  20. Hepatobiliary diseases in small animals: a comparison of ultrasonography and multidetector-row computed tomography

    Borsetto, Antonella

    2011-01-01

    Ultrasonography (US) is an essential imaging tool for identifying abnormalities of the liver parenchyma, biliary tract and vascular system. US has replaced radiography as the initial imaging procedure in screening for liver disease in small animals. There are few reports of the use of conventional and helical computed tomography (CT) to assess canine or feline parenchymal and neoplastic liver disease and biliary disorders. In human medicine the development of multidetector- row helical comput...

  1. Does a virtual audience influence rowing?

    Wellner, M; Sigrist, R; von Zitzewitz, J.; P. Wolf; Riener, R

    2010-01-01

    The performance of athletes is often influenced by the presence of an audience. This pressure situation, which is common for competition, cannot be trained for on available simulators. Therefore, a novel rowing simulator with virtual reality technology was developed and evaluated. Ten participants of different skill levels were rowing 3 × 1000 m with positive, neutral, and negative virtual audience tribunes in blocks of random order. The analysis of movement variables, physiological response,...

  2. Interactive motion tracing for Rowing Training

    Dai, Zheng

    2011-01-01

    can correct the path immediately and save the corrected path for the rower to try to imitate and train. The members in a rowing team train with the same path from to coordinate and synchronize their actions for the best performance. The training system was developed through a user-centered design...... process with Danske Studenters Roklub. It was designed in iterations to provide a new experience for rowing sport training by coaching in real-time, training interactively, and perceiving directly....

  3. Machine Learning Analysis of Binaural Rowing Sounds

    Filippeschi Alessandro; Hoffmann Pablo; Ruffaldi Emanuele; Johard Leonard

    2011-01-01

    Techniques for machine hearing are increasing their potentiality due to new application domains. In this work we are addressing the analysis of rowing sounds in natural context for the purpose of supporting a training system based on virtual environments. This paper presents the acquisition methodology and the evaluation of different machine learning techniques for classifying rowing-sound data. We see that a combination of principal component analysis and shallow networks perform equally wel...

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

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

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

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

    2013-08-15

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

  6. Evaluation of 320-row area detector computed tomography (ADCT) coronary angiography for patients with atrial fibrillation

    The aim of this study was to evaluate 320-row area detector CT (ADCT) for patients with atrial fibrillation (Af) based on simulated exposure using electrocardiogram RR intervals and comparison with the findings of coronary CT angiography (CCTA) using 64-row multi slice CT (MSCT). The probability of including RR intervals of 900 ms or more was calculated when the acquisition time was varied from 1 to 4 beats. Overall, 51 patients with Af who underwent CCTA were examined. The exposure time for CCTA, the total dose length product (DLP) for the examination, and the image quality (scored 0 to 3: poor to excellent) were compared between ADCT and MSCT. The probability of including RR intervals of 900 ms or more was highly significantly increased at 3 beats of acquisition time. The exposure time using ADCT was reduced by 75% compared with MSCT (ADCT/MSCT: 2.8/11.3 s), and the total DLP was reduced by 40% (ADCT/MSCT: 1398/2277 mGy·cm). Moreover, ADCT provided diagnosable images in all cases, and the mean image quality score for ADCT was significantly higher than that for MSCT (ADCT/MSCT: 2.8/2.4). Thus, 320-row ADCT at 3 beats of acquisition time can provide CCTA images of acceptable quality for patients with Af. (author)

  7. Study on the law of radiant directionality of row crops

    陈良富; 庄家礼; 柳钦火; 徐希孺; 田国良

    2000-01-01

    The style of crops planting is frequently in row-structure, the row-structure style may result in big difference among the sunlit, shaded soil surface and foliage temperatures and cause pixel component to vary in azimuth orientation, these further lead to the change of radiant directionality of row crops in the zenith and azimuth orientations. Since the row crops are often tackled as isotropic in the azimuth orientation based on continuous vegetation assumption, big errors will be brought about. In order to eliminate the errors, it is necessary to study the law of radiant directionality of the row crops. In this paper, Monte Carlo method has been employed to simulate the angular effects on radiation caused by row architecture parameters. The simulated results show that the parameters, for example, row height, row width, row interval between the neighbor rows and the leaf area index have significant influences on the radiant directionality, but the azimuth orientation ranks the first among the parameters

  8. Management controls on nitrous oxide emissions from row crop agriculture

    Gelfand, I.; Shcherbak, I.; Millar, N.; Robertson, G. P.

    2011-12-01

    Agriculture is a significant source of the potent greenhouse gas (GHG) nitrous oxide (N2O), accounting for ~70% of total anthropic N2O emissions in the US primarily as a result of N fertilizer application. Emissions of N2O are the largest contributor to the global warming potential of row-crop agriculture. Management, including choice of crop type and rotation strongly impacts N2O emissions, but continuous emissions data from row-crops over multiple rotations are lacking. Empirical quantification of these long-term emissions and the development of crop- and rotation-specific N2O emission factors are vital for improving estimates of agricultural GHG emissions, important for informing management practices to reduce agriculture's GHG footprint, and developing mitigation protocols for environmental markets. Over 20 years we measured soil N2O emissions and calculated crop and management specific emission factors in four continuous rotations of corn (Zea mays) - soybean (Glycine max) - wheat (Triticum aestivum) under conventional tillage (CT), zero tillage (NT), low chemical input (LI), and biologically (Org) based management. Two of these systems (LI and Org) included winter cover crops, red clover (Trifolium pratense) or ray (Secale cereale). While average soil N2O fluxes in all systems where similar (2.9±0.2 to 3.8±0.5 g N2O-N ha-1 d-1), there was a significant interaction of total emissions with crop and phase. Surprisingly, the lowest total emissions from the corn period of the rotation were from CT, and the highest from LI, with 608±4 and 983±8 g N2O-N ha-1 crop year-1, respectively. Total emissions during the wheat period of the rotation showed the opposite trend, with total emissions of 942±7 and 524±38 g N2O-N ha-1 crop year-1, for CT ant LI, respectively. Total emissions from the soybean period of the rotation were highest under NT and lowest under CT management (526±5 and 296±2 g N2O-N ha-1 crop year-1, respectively). Emission efficiency, N2O emitted

  9. Comparison of Single Row, Twin Row, and Diamond Planting Patterns in Valencia Peanut

    Most Valencia peanuts are grown in single rows on 36 to 40 inch beds. Because of their bunch-type and erect growth habit, Valencia peanuts do not spread over the whole bed and have the opportunity to benefit from multiple row planting arrangements. This study was conducted at locations near Portal...

  10. Neutron camera employing row and column summations

    Clonts, Lloyd G.; Diawara, Yacouba; Donahue, Jr, Cornelius; Montcalm, Christopher A.; Riedel, Richard A.; Visscher, Theodore

    2016-06-14

    For each photomultiplier tube in an Anger camera, an R.times.S array of preamplifiers is provided to detect electrons generated within the photomultiplier tube. The outputs of the preamplifiers are digitized to measure the magnitude of the signals from each preamplifier. For each photomultiplier tube, a corresponding summation circuitry including R row summation circuits and S column summation circuits numerically add the magnitudes of the signals from preamplifiers for each row and for each column to generate histograms. For a P.times.Q array of photomultiplier tubes, P.times.Q summation circuitries generate P.times.Q row histograms including R entries and P.times.Q column histograms including S entries. The total set of histograms include P.times.Q.times.(R+S) entries, which can be analyzed by a position calculation circuit to determine the locations of events (detection of a neutron).

  11. Automatic crop row detection from UAV images

    Midtiby, Henrik; Rasmussen, Jesper

    Images from Unmanned Aerial Vehicles can provide information about the weed distribution in fields. A direct way is to quantify the amount of vegetation present in different areas of the field. The limitation of this approach is that it includes both crops and weeds in the reported num- bers. To get a...... considered weeds. We have used a Sugar beet field as a case for evaluating the proposed crop detection method. The suggested image processing consists of: 1) locating vegetation regions in the image by thresholding the excess green image derived from the orig- inal image, 2) calculate the Hough transform of...... the segmented image 3) determine the dominating crop row direction by analysing output from the Hough transform and 4) use the found crop row direction to locate crop rows....

  12. Role of multidetector row computed tomography in the assessment of adrenal gland injuries

    Objective: To determine the prevalence of adrenal injuries in a group of patients submitted to multidetector row CT evaluation after blunt trauma and to assess the impact of CT findings on clinical management decisions. Materials and method: During a 4-year period, 2026 emergency CT examinations were performed in the setting of major blunt trauma. A total of 82 patients were retrospectively identified as having adrenal gland traumatic lesions. At multidetector row CT the following findings were considered specific of adrenal injury: round or oval hematoma expanding the adrenal gland, irregular hemorrhage obliterating the gland, uniform adrenal gland swelling, active extravasation of contrast material from the adrenal vessels and adrenal gland rupture. Associated CT findings were: stranding of the periadrenal fat, diffuse hemorrhage in the adjacent retroperitoneum and compression of the adrenal gland by adjacent traumatic lesions. Results: We identified 82 patients (46 males and 36 females, age ranging from 15 to 86 years) with adrenal injuries. The right adrenal gland was injured in 60/82 patients, while the left adrenal gland was injured in 21 cases; in 1 patient bilateral adrenal gland traumatic lesions occurred. In 76 patients with non-isolated adrenal injuries concomitant injuries to the liver (49 cases), ipsilateral kidney (18 cases) and spleen (9 cases) were observed. Round or oval hematoma expanding the adrenal gland (61 cases), irregular hemorrhage obliterating the gland (14 cases), stranding of the periadrenal fat (9 cases) and diffuse hemorrhage in the adjacent retroperitoneum (8 cases) were the more frequent findings detected at CT. Six patients underwent surgical intervention for the presence of major injuries to the spleen (three cases), to the liver (one), to the right kidney (one), to the left kidney (one). Seventy-six patients were conservatively treated. Conclusion: Blunt adrenal injuries typically present as part of a multiorgan trauma

  13. Machine learning analysis of binaural rowing sounds

    Johard, Leonard; Ruffaldi, Emanuele; Hoffmann, Pablo F.;

    2011-01-01

    Techniques for machine hearing are increasing their potentiality due to new application domains. In this work we are addressing the analysis of rowing sounds in natural context for the purpose of supporting a training system based on virtual environments. This paper presents the acquisition metho...... methodology and the evaluation of different machine learning techniques for classifying rowing-sound data. We see that a combination of principal component analysis and shallow networks perform equally well as deep architectures, while being much faster to train....

  14. Machine Learning Analysis of Binaural Rowing Sounds

    Filippeschi Alessandro

    2011-12-01

    Full Text Available Techniques for machine hearing are increasing their potentiality due to new application domains. In this work we are addressing the analysis of rowing sounds in natural context for the purpose of supporting a training system based on virtual environments. This paper presents the acquisition methodology and the evaluation of different machine learning techniques for classifying rowing-sound data. We see that a combination of principal component analysis and shallow networks perform equally well as deep architectures, while being much faster to train.

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

    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)

  16. Flexible frontiers for text division into rows

    Dan L. Lacrămă

    2009-01-01

    Full Text Available This paper presents an original solution for flexible hand-written text division into rows. Unlike the standard procedure, the proposed method avoids the isolated characters extensions amputation and reduces the recognition error rate in the final stage.

  17. Rowing complex in Račice

    Švácha, Rostislav

    Prague: Prostor - architektura, interiér, design, 2012 - (Švácha, R.), s. 236-239 ISBN 978-80-87064-09-2 Institutional support: RVO:68378033 Keywords : Račice * architecture * rowing Subject RIV: AL - Art, Architecture, Cultural Heritage

  18. Conventional and CT angiography in children: dosimetry and dose comparisons

    Tremendous advances have been made in imaging in children with both congenital and acquired heart disease. These include technical advances in cardiac catheterization and conventional angiography, especially with advancements in interventional procedures, as well as noninvasive imaging with MR and CT angiography. With rapid advances in multidetector CT (MDCT) technology, most recently 64-detector array systems (64-slice MDCT), have come a number of advantages over MR. However, both conventional and CT angiography impart radiation dose to children. Although the presence of radiation exposure to children has long been recognized, it is apparent that our ability to assess this dose, particularly in light of the rapid advancements, has been limited. Traditional methods of dosimetry for both conventional and CT angiography are somewhat cumbersome or involve a potential for substantial uncertainty. Recent developments in dosimetry, including metal oxide semiconductor field effect transistors (MOSFET) and the availability of anthropomorphic, tissue-equivalent phantoms have provided new opportunities for dosimetric assessments. Recent work with this technology in state-of-the-art cardiac angiography suites as well as with MDCT have offered direct comparisons of doses in infants and children undergoing diagnostic cardiac evaluation. It is with these dose data that assessment of risks, and ultimately the assessment of risk-benefit, can be better achieved. (orig.)

  19. Radiation model for row crops: II. Model evaluation

    Relatively few radiation transfer studies have considered the impact of varying vegetation cover that typifies row crops, and meth¬ods to account for partial row crop cover have not been well investigated. Our objective was to evaluate a widely used radiation model that was modified for row crops ha...

  20. CT Scans

    ... cross-sectional pictures of your body. Doctors use CT scans to look for Broken bones Cancers Blood clots Signs of heart disease Internal bleeding During a CT scan, you lie still on a table. The table ...

  1. Integrated control of annual weeds by inter-row hoeing and intra-row herbicide treatment in spring oilseed rape

    Nilsson, Anders

    2014-02-01

    Full Text Available The aim of this project is to develop an integrated weed control strategy against annual weeds in spring oilseed rape by means of a combined mechanical and chemical weed control which will be performed concurrently and separately. The project encompasses field experiments in which different combinations of inter-row hoeing and intra-row herbicide treatments will be evaluated and compared to conventional weed control treatments with broadcast spraying of herbicides, and experiments in which an implement for concurrent inter-row hoeing and intra-row herbicide treatment will be refined and evaluated. In 2012, an implement for intra-row spraying combined with row hoeing was developed and evaluated in two field experiments in spring oilseed rape in the southern part of Sweden. The effects of inter-row hoeing, intra row spraying, and combination of the two methods were compared with conventional broadcast spraying. Preliminary results showed that the best weed control effects were obtained with the combination of inter-row hoeing and intra-row spraying in both experiments. Regarding crop yield, the yield was significantly higher in the combined treatment in one of the experiments while no effects on the yields were obtained in the other experiment. We envisage that the inter-row hoeing and intra-row herbicide treatment will diminish the overall use of herbicides to less than one third in comparison with the more conventional chemical weed control methods, while having the same weed control effect.

  2. Row-strict quasisymmetric Schur functions

    Mason, Sarah

    2011-01-01

    Haglund, Luoto, Mason, and van Willigenburg introduced a basis for quasisymmetric functions called the quasisymmetric Schur function basis, generated combinatorially through fillings of composition diagrams in much the same way as Schur functions are generated through reverse column-strict tableaux. We introduce a new basis for quasisymmetric functions called the row-strict quasisymmetric Schur function basis, generated combinatorially through fillings of composition diagrams in much the same way as Schur functions are generated through row-strict tableaux. We describe the relationship between this new basis and other known bases for quasisymmetric functions, as well as its relationship to Schur polynomials. We obtain a refinement of the omega transform operator as a result of these relationships.

  3. Compressed Multiple-Row Storage Format

    Koza, Zbigniew; Szkoda, Sebastian; Mirosław, Łukasz

    2012-01-01

    A new format for storing sparse matrices is proposed for efficient sparse matrix-vector (SpMV) product calculation on modern throughput-oriented computer architectures. This format extends the standard compressed row storage (CRS) format and is easily convertible to and from it without any memory overhead. Computational performance of an SpMV kernel for the new format is determined for over 140 sparse matrices on two Fermi-class graphics processing units (GPUs) and the efficiency of the kernel, which peaks at 36 and 25 GFLOPS at single and double precision, respectively, is compared with that of five existing generic algorithms and industrial implementations. The efficiency of the new format is also measured as a function of the mean (\\mu) and of the standard deviation (\\sigma) of the number of matrix nonzero elements per row. The largest speedup is found for matrices with \\mu > 20 and \\mu > \\sigma > 1.5 and can be as high as 43%.

  4. PET/CT - Current status

    From autoradiography to planar X rays, computed tomography (CT) and Magnetic Resonance (MR), morphology and structure has been the mainstay of biological and medical imaging for over a century. While structural changes may suggest the presence of disease, functional changes are more sensitive indicators of early-stage pathology, and with cancer, early detection is the key to a favorable prognosis. Since molecular imaging offers the potential to quantitatively image functional changes in vivo, it is assuming an increasingly important role in the identification, staging and re-staging of human disease. Specifically, Positron Emission Tomography (PET) and Single Photon Emission Computed Tomography (SPECT) are sensitive techniques to map human physiology non-invasively through the use of high-resolution imaging devices and appropriate radioactively-labeled biomarkers. However, such metabolic maps do not offer the structural detail associated with anatomical imaging techniques such as CT and MR and therefore dual modality devices such as PET/CT, SPECT/CT or PET/MR that combine both structural and functional information offer a more complete and accurate assessment of the status of disease. PET/CT instrumentation, for example, was first introduced into the clinic in 2001 and since then, progress has been rapid. Technological advances in each modality, CT and PET, have been consistently incorporated into the combined device ensuring state-of-the-art performance for PET/CT. Recent advances in CT include an increase in the number of detector rows or slices (from 1 to 64), a reduction in rotation times (to less than 0.5 s), and the emergence of the first CT scanner incorporating dual X ray sources. Paralleling these advances, PET instrumentation has witnessed the introduction of new faster scintillators, higher resolution detectors, increased sensitivity through extended axial coverage, and the resurgence of time-of-flight information to improve image signal-to-noise. A

  5. SVD row or column symmetric matrix

    2000-01-01

    A new architecture for row or column symmetric matrix called extended matrix is defined, and a precise correspondence of the singular values and singular vectors between the extended matrix and its original (namely, the mother matrix) is derived. As an illustration of potential, we show that, for a class of extended matrices, the singular value decomposition using the mother matrix rather than the extended matrix per se can save the CPU time and memory without loss of numerical precision.

  6. Strength and conditioning practices in rowing

    Gee, Thomas

    2008-01-01

    There is minimal research on the practices of strength and conditioning coaches in England. Information about training programme design could be useful in developing models of good practice and ecologically valid intervention studies. The aim of the research was to quantify the training practices of coaches responsible for the strength and conditioning of rowing athletes. A questionnaire was developed and consisted of six sections: (a) personal details, (b) physical testing, (c) strength/powe...

  7. Proximal Row Carpectomy Combined with Wrist Hemiarthroplasty

    Culp, Randall W.; Bachoura, Abdo; Gelman, Scott E.; Jacoby, Sidney M.

    2012-01-01

    Proximal row carpectomy (PRC) combined with distal radius hemiarthroplasty is a relatively novel procedure that rivals total wrist arthrodesis and offers a new surgical treatment option for select patients with painful, end-stage wrist disease. We present our early experience with this procedure. A retrospective chart review was conducted for nonrheumatoid patients diagnosed with wrist arthritis and subsequently treated with wrist hemiarthroplasty combined with PRC. The minimum follow-up dura...

  8. Strength and conditioning practices in rowing

    Gee, Thomas I.; Olsen, Peter D.; Berger, Nicolas J.; Golby, Jim; Thompson, Kevin G.

    2011-01-01

    There is limited published research on the practices of strength and conditioning (S &C) coaches in Great Britain. Information about training program design would be useful in developing models of good practice and ecologically valid intervention studies. The aim of this research was to quantify the training practices of coaches responsible for the S&C of rowing athletes. A questionnaire was developed that consisted of 6 sections: (a) personal details, (b) physical testing, (c) strength and p...

  9. Extended abstract: Partial row projection methods

    Bramley, R.; Lee, Y. [Indiana Univ., Bloomington, IN (United States)

    1996-12-31

    Accelerated row projection (RP) algorithms for solving linear systems Ax = b are a class of iterative methods which in theory converge for any nonsingular matrix. RP methods are by definition ones that require finding the orthogonal projection of vectors onto the null space of block rows of the matrix. The Kaczmarz form, considered here because it has a better spectrum for iterative methods, has an iteration matrix that is the product of such projectors. Because straightforward Kaczmarz method converges slowly for practical problems, typically an outer CG acceleration is applied. Definiteness, symmetry, or localization of the eigenvalues, of the coefficient matrix is not required. In spite of this robustness, work has generally been limited to structured systems such as block tridiagonal matrices because unlike many iterative solvers, RP methods cannot be implemented by simply supplying a matrix-vector multiplication routine. Finding the orthogonal projection of vectors onto the null space of block rows of the matrix in practice requires accessing the actual entries in the matrix. This report introduces a new partial RP algorithm which retains advantages of the RP methods.

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

    Jong Gyu Kim; Soo Hyang Lee

    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...

  11. Diagnostic performance of combined noninvasive coronary angiography and myocardial perfusion imaging using 320 row detector computed tomography

    Vavere, Andrea L; Simon, Gregory G; George, Richard T;

    2013-01-01

    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...... disease compared with (1) the combination of conventional coronary angiography and SPECT-MPI and (2) conventional coronary angiography alone. If successful, the technology could revolutionize the management of patients with symptomatic CAD....

  12. Cardiac CT: a one-stop-shop procedure?

    Becker, C.R. [Dept. of Clinical Radiology, Univ. Hospital Grosshaderm, Munich (Germany)

    2006-01-10

    Multidetector row CT of the heart and coronary arteries is now a robust clinical method. It may be used in a number of different clinical scenarios, such as in the presence of an equivocal stress test or ambiguous clinical symptoms. Cardiac CT is also increasingly being developed as a diagnostic option for acute care such as in acute coronary syndrome. Here CT may serve as a tool to triage patients to appropriate therapy or to discharge them immediately after the investigation. The newest dual source CT also allows the assessment of cardiac function, helping to specify the diagnosis. Valve assessment by CT is still under investigation. However multidetector CT is of limited value in myocardial perfusion or for late myocardial enhancement scanning. Appropriate selection of patients for cardiac multidetector CT is mandatory so that the procedure is carried out only in those in whom it can provide clinically valuable information. (orig.)

  13. Principle and applications of dual source CT

    Flohr, Thomas

    2008-08-01

    Dual source CT (DSCT) has the potential to solve remaining limitations of conventional multi-detector row CT (MDCT)-scanners, such as insufficient temporal resolution for ECG-controlled cardiac imaging. A DSCT is equipped with two X-ray tubes and two corresponding detectors that are mounted onto the rotating gantry with an angular offset of 90°. The key benefit of DSCT for cardiac scanning is improved temporal resolution equivalent to a quarter of the gantry rotation time (83 ms at 0.33 s rotation time). Additionally, both X-ray tubes can be operated at different kV- and mA-settings, enabling the acquisition of dual energy data. The acquisition of dual energy CT data can add functional information to the morphological information based on different X-ray attenuation coefficients that is usually obtained in a CT examination.

  14. Study on the law of radiant directionality of row crops

    2000-01-01

    The style of crops planting is frequently in row-structure,the row-structure style may result in big difference among the sunlit,shaded soil surface and foliage temperatures and cause pixel component to vary in azimuth orientation,these further lead to the change of radiant directionality of row crops in the zenith and azimuth orientations.Since the row crops are often tackled as isotropic in the azimuth orientation based on continuous vegetation assumption,big errors will be brought about.In order to eliminate the errors,it is necessary to study the law of radiant directionality of the row crops.In this paper,Monte Carlo method has been employed to simulate the angular effects on radiation caused by row architecture parameters.The simulated results show that the parameters,for example,row height,row width,row interval between the neighbor rows and the leaf area index have significant influences on the radiant directionality,but the azimuth orientation ranks the first among the parameters.

  15. Coronary computed tomography angiography with 320-row detector and using the AIDR-3D: initial experience

    Coronary computed tomography angiography (coronary CTA) is a powerful non-invasive imaging method to evaluate coronary artery disease. Nowadays, coronary CTA estimated effective radiation dose can be dramatically reduced using state-of-the-art scanners, such as 320-row detector CT (320-CT), without changing coronary CTA diagnostic accuracy. To optimize and further reduce the radiation dose, new iterative reconstruction algorithms were released recently by several CT manufacturers, and now they are used routinely in coronary CTA. This paper presents our first experience using coronary CTA with 320-CT and the Adaptive Iterative Dose Reduction 3D (AIDR-3D). In addition, we describe the current indications for coronary CTA in our practice as well as the acquisition standard protocols and protocols related to CT application for radiation dose reduction. In conclusion, coronary CTA radiation dose can be dramatically reduced following the 'as low as reasonable achievable' principle by combination of exam indication and well-documented technics for radiation dose reduction, such as beta blockers, low-kV, and also the newest iterative dose reduction software as AIDR-3D. (author)

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

    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.

  17. Row charge cratering calculations. [Feasibility studies

    Miller, L.W.; Matuska, W.

    1978-06-01

    Two-dimensional calculations have been done to determine the feasibility of constructing deep canals with nuclear explosives subject to the limitation in the proposed PNE Treaty. The conditions under which a series of explosives set in a row can be approximated by a cylindrical line source have been determined. Using this result, the possibility of lifting 250 m of overburden with 150-kt charges spaced at 50-m intervals has been investigated. This study shows that for a variety of equations of state for the geological medium, there appears little possibility that such an excavation can be accomplished.

  18. Cultivar and row distance interactions in perennial ryegrass

    Deleuran, Lise C; Gislum, René; Boelt, Birte

    2009-01-01

    was not affected in the first-year seed production in three perennial ryegrass cultivars. Regardless of row distance the seed rate was 6 kg ha-1 and hence in-row plant density in autumn and spring was higher at 48 compared with 12 cm; however, in all three cultivars the highest number of reproductive...... tillers was recorded at 12-cm row distance. Row distance affected seed yields of only the diploid amenity cultivar 'Allegro', where a row distance of 48 cm reduced the seed yield compared with 12- and 24-cm row distance. When data from the three cultivars were merged there was a positive correlation...... between the seed yield and seed weight (r=0.72***), whereas the correlation between seed yield and the number of reproductive tillers was negatively correlated (r= - 0.49***). This may reflect choice of cultivars in the experiment with the tetraploid forage cultivar 'Tivoli' having the lowest number of...

  19. A New Submaximal Rowing Test to Predict 2,000-m Rowing Ergometer Performance.

    Otter, Ruby T A; Brink, Michel S; Lamberts, Robert P; Lemmink, Koen A P M

    2015-09-01

    The purpose of this study was to assess predictive value of a new submaximal rowing test (SmRT) on 2,000-m ergometer rowing time-trial performance in competitive rowers. In addition, the reliability of the SmRT was investigated. Twenty-four competitive male rowers participated in this study. After determining individual HRmax, all rowers performed an SmRT followed by a 2,000-m rowing ergometer time trial. In addition, the SmRT was performed 4 times (2 days in between) to determine the reliability. The SmRT consists of two 6-minute stages of rowing at 70 and 80% HRmax, followed by a 3-minute stage at 90% HRmax. Power was captured during the 3 stages, and 60 seconds of heart rate recovery (HRR60s) was measured directly after the third stage. Results showed that predictive value of power during the SmRT on 2,000-m rowing time also increased with stages. CVTEE% is 2.4, 1.9, and 1.3%. Pearson correlations (95% confidence interval [95% CI]) were -0.73 (-0.88 to -0.45), -0.80 (-0.94 to -0.67), and -0.93 (-0.97 to -0.84). 2,000-m rowing time and HRR60s showed no relationship. Reliability of power during the SmRT improved with the increasing intensity of the stages. The coefficient of variation (CVTEM%) was 9.2, 5.6, and 0.4%. Intraclass correlation coefficients (ICC) and 95% CI were 0.91 (0.78-0.97), 0.92 (0.81-0.97), and 0.99 (0.97-1.00). The CVTEM% and ICC of HRR60s were 8.1% and 0.93 (0.82-0.98). In conclusion, the data of this study shows that the SmRT is a reliable test that it is able to accurately predict 2,000-m rowing time on an ergometer. The SmRT is a practical and valuable submaximal test for rowers, which can potentially assist with monitoring, fine-tuning and optimizing training prescription in rowers. PMID:25774627

  20. The Adaptive Control of FES-assisted Indoor Rowing Exercise

    Hussain, Zakaria; Bin Zaidan, Martha Arbayani; M.O. Tokhi; Jailani, Rozita

    2009-01-01

    This paper describes the development of an adaptive control mechanism for FES-assisted indoor rowing exercise (FES-rowing). The FES-rowing is intro-duced as a total body exercise for rehabilitation of function of lower body through the application of functional elec-trical stimulation (FES). A model of the rowing ergometer with humanoid is developed using the visual Nastran soft-ware environment (vN4D). A fuzzy logic control (FLC) scheme is designed in Matlab/Simulink and adapted online by pr...

  1. NUMERICAL MODEL APPLICATION IN ROWING SIMULATOR DESIGN

    Petr Chmátal

    2016-04-01

    Full Text Available The aim of the research was to carry out a hydraulic design of rowing/sculling and paddling simulator. Nowadays there are two main approaches in the simulator design. The first one includes a static water with no artificial movement and counts on specially cut oars to provide the same resistance in the water. The second approach, on the other hand uses pumps or similar devices to force the water to circulate but both of the designs share many problems. Such problems are affecting already built facilities and can be summarized as unrealistic feeling, unwanted turbulent flow and bad velocity profile. Therefore, the goal was to design a new rowing simulator that would provide nature-like conditions for the racers and provide an unmatched experience. In order to accomplish this challenge, it was decided to use in-depth numerical modeling to solve the hydraulic problems. The general measures for the design were taken in accordance with space availability of the simulator ́s housing. The entire research was coordinated with other stages of the construction using BIM. The detailed geometry was designed using a numerical model in Ansys Fluent and parametric auto-optimization tools which led to minimum negative hydraulic phenomena and decreased investment and operational costs due to the decreased hydraulic losses in the system.

  2. Standardized CT protocols and nomenclature: better, but not yet there

    Radiation dose associated with CT is an important safety concern in patient care, especially in children. Technical advancements in multidetector-row CT scanner technology offer several advantages for clinical applications; these advancements have considerably increased CT utilization and enhanced the complexity of CT scanning protocols. Furthermore there are several scan manufacturers spearheading these technical advancements, leading to different commercial names causing confusion among the users, especially at imaging sites with scanners from different vendors. Several scientific studies and the National Council on Radiation Protection and Measurements (NCRP) have shown variation in CT radiation doses for same body region and similar scanning protocols. Therefore there is a need for standardization of scanning protocols and nomenclature of scan parameters. The following material reviews the status and challenges in standardization of CT scanning and nomenclature. (orig.)

  3. Quantitative thoracic CT techniques in adults: can they be applied in the pediatric population?

    Yoon, Soon Ho [Seoul National University Medical Research Center, Department of Radiology, Seoul National University College of Medicine, and Institute of Radiation Medicine, Seoul (Korea, Republic of); Goo, Jin Mo [Seoul National University Medical Research Center, Department of Radiology, Seoul National University College of Medicine, and Institute of Radiation Medicine, Seoul (Korea, Republic of); Seoul National University College of Medicine, Cancer Research Institute, Jongno-gu, Seoul (Korea, Republic of); Goo, Hyun Woo [University of Ulsan College of Medicine, Department of Radiology and Research Institute of Radiology, Asan Medical Center, Seoul (Korea, Republic of)

    2013-03-15

    With the rapid evolution of the multidetector row CT technique, quantitative CT has started to be used in clinical studies for revealing a heterogeneous entity of airflow limitation in chronic obstructive pulmonary disease that is caused by a combination of lung parenchymal destruction and remodeling of the small airways in adults. There is growing evidence of a good correlation between quantitative CT findings and pathological findings, pulmonary function test results and other clinical parameters. This article provides an overview of current quantitative thoracic CT techniques used in adults, and how to translate these CT techniques to the pediatric population. (orig.)

  4. CT pelvimetry

    Pelvimetry aims at providing the obstetrician with information on the size and morphology of the female pelvis, thus enabling him to assess the obstetrical prognosis as accurately as possible. Computed tomography (CT) has several advantages, in particular the lower mother and fetus radiation dose. After a brief description of obstetrical anatomy, the usual CT exploration method is presented and its results are considered in terms of measurements, indices and morphological findings. If performed with a very strict exploration procedure, CT pelvimetry is a very reliable, fact and comfortable method of examination. All these advantages, combined with the minimized patient dose, should lead to an increasingly widespread use of this technique

  5. Exploratory analysis on the binaural characteristics of the rowing sound

    Fillipeschi Alessandro; Ruffaldi Emanuele; Hammershøi Dorte; Hoffmann Pablo F.

    2011-01-01

    Differences between the signals captured at the entrances to the left and right ears are generally quantified by interaural time differences (ITDs), interaural level differences (ILDs) and interaural crosscorrelation (IC). Here, we attempt to gain knowledge on the changes of these interaural parameters during rowing and to evaluate their potential as source of information to determine rowing expertise exclusively from acoustic signals.

  6. Rows of Dislocation Loops in Aluminium Irradiated by Aluminium Ions

    Henriksen, L.; Johansen, A.; Koch, J.;

    1967-01-01

    Single-crystal aluminium specimens, irradiated with 50-keV aluminium ions, contain dislocation loops that are arranged in regular rows along <110 > directions. ©1967 The American Institute of Physics......Single-crystal aluminium specimens, irradiated with 50-keV aluminium ions, contain dislocation loops that are arranged in regular rows along <110 > directions. ©1967 The American Institute of Physics...

  7. Analysis of indoor rowing motion using wearable inertial sensors

    Bosch, Stephan; Shoaib, Muhammad; Geerlings, Stephen; Buit, Lennart; Meratnia, Nirvana; Havinga, Paul

    2015-01-01

    In this exploratory work the motion of rowers is analyzed while rowing on a rowing machine. This is performed using inertial sensors that measure the orientation at several positions on the body. Using these measurements, this work provides a preliminary analysis of the differences between experienc

  8. Effect of BMI on Knee Joint Torques in Ergometer Rowing

    Roemer, Karen; Hortobagyi, Tibor; Richter, Chris; Munoz-Maldonado, Yolanda; Hamilton, Stephanie

    2013-01-01

    Although an authoritative panel recommended the use of ergometer rowing as a non-weight-bearing form of exercise for obese adults, the biomechanical characterization of ergometer rowing is strikingly absent. We examined the interaction between body mass index (BMI) relative to the lower extremity bi

  9. System manual for the University of Pennsylvania retrofitted solar heated Philadelphia row home (SolaRow)

    Zinnes, I.; Lior, N.

    1980-05-01

    The University of Pennsylvania SolaRow house, an urban row home retrofitted for comfort and domestic hot water heating, was extensively instrumented for performance monitoring and acquisition of weather and solar radiation data. This report describes the heating and instrumentation systems, provides the details for instrumentation, piping and valve identification, and specifies the operation and maintenance of the heating and data acquisition systems. The following are included: (1) system flow diagrams; (2) valve and cable identification tables; (3) wiring diagrams; and (4) start-up, normal operation, shut-down, maintenance and trouble-shooting procedures. It thus provides the necessary technical information to permit system operation and monitoring, overall system performance analysis and optimization, and acquisition of climatological data.

  10. CT scan

    ... come from a CT scan. Some people have allergies to contrast dye. Let your doctor know if you have ... vein contains iodine. If you have an iodine allergy, a type of contrast may cause nausea or vomiting , sneezing , itching , or ...

  11. Frequently asked questions in the interpretation of preoperative and postoperative chest CT scans related to lung cancer imaging

    With the advent of multidetector-row CT, lung cancer imaging is much more promising than before. However, the effectiveness of multidetector-row CT in making an initial diagnosis, staging, and evaluating post-treatment changes of lung cancer still remains to be proved. Fast imaging along with volumetric data set and attendant multi-planar imaging provide much more details on the anatomic changes and pathology associated with lung cancer. However, with images showing anatomic and pathologic changes only, radiologists confront with several questions the answers of which may help evaluate lung cancer more thoroughly. The frequent questions that I have in daily practice of chest CT interpretation are as follows

  12. Estimation of radiation exposure in 16-detector row computed tomography of the heart with retrospective ECG-gating

    Purpose: We sought to evaluate the radiation exposure of cardiac CT scans with 16-row multidetector computed tomography (MDCT). Additionally the possibility of dose reduction by using a ECG-controlled tube current modulation technique was evaluated. Methods and Material: An Alderson Rando phantom equipped with thermoluminescent dosimeters was used for dose measurements. Effective dose was calculated according to ICRP 60. Exposure was performed on a 16-row MDCT scanner with standard protocols for CT coronary calcium scoring (120 kV, 133 mAs, 12 x 1,5 mm) and CT coronary angiography (120 kV, 400 mAs, 12 x 0,75 mm). Exposure was repeated at a simulated heart rate of 60 bpm with ECG-pulsed tube current modulation. Results: Effective dose was 2,9 mSv (male) and 3,6 mSv (female) for the calcium scoring protocol. CT coronary angiography resulted in an effective dose of 8,1 mSv (male) and 10,9 mSv (female). Using ECG-pulsed tube current modulation radiation exposure can significant reduced: by 46% (1,6 mSv) in calcium scoring and by 47% (4,3 mSv) in CT coronary angiography. Conclusion: MDCT of the heart shows a significant radiation exposure, which can significantly be reduced by ECG-pulsed tube current modulation. Radiation exposure of cardiac MDCT is comparable to CT-examinations of chest or abdomen, but seem to be slightly higher compared to conventional coronary angiography. (orig.)

  13. Head CT scan

    Brain CT; Cranial CT; CT scan - skull; CT scan - head; CT scan - orbits; CT scan - sinuses; Computed tomography - cranial ... The x-rays produced by the CT scan are painless. Some people may ... hard table. Contrast given through a vein may cause a: Slight ...

  14. Biomechanical determinants of elite rowing technique and performance.

    Buckeridge, E M; Bull, A M J; McGregor, A H

    2015-04-01

    In rowing, the parameters of injury, performance, and technique are all interrelated and in dynamic equilibrium. Whilst rowing requires extreme physical strength and endurance, a high level of skill and technique is essential to enable an effective transfer of power through the rowing sequence. This study aimed to determine discrete aspects of rowing technique, which strongly influence foot force production and asymmetries at the foot-stretchers, as these are biomechanical parameters often associated with performance and injury risk. Twenty elite female rowers performed an incremental rowing test on an instrumented rowing ergometer, which measured force at the handle and foot-stretchers, while three-dimensional kinematic recordings of the ankle, knee, hip, and lumbar-pelvic joints were made. Multiple regression analyses identified hip kinematics as a key predictor of foot force output (R(2)  = 0.48), whereas knee and lumbar-pelvic kinematics were the main determinants in optimizing the horizontal foot force component (R(2)  = .41). Bilateral asymmetries of the foot-stretchers were also seen to significantly influence lumbar-pelvic kinematics (R(2)  = 0.43) and pelvic twisting (R(2)  = 0.32) during the rowing stroke. These results provide biomechanical evidence toward aspects of technique that can be modified to optimize force output and performance, which can be of direct benefit to coaches and athletes. PMID:25039605

  15. A New Hoe Blade for Inter-Row Weeding

    Green, O.; Znova, L.; Melander, Bo

    2016-01-01

    New camera-based systems for automatic steering of inter-row cultivators have made it possible to conduct inter-row weeding in small inter-row spaces at reasonable work rates. This has motivated organic growers to shift from full-width weed harrowing of small grain cereals to inter-row hoeing. The...... aim is mainly to improve weeding effectiveness against tall-growing and tap-rooted weed species. The ‘Ducksfoot’ hoe blade is commonly used for traditional inter-row weeding in row crops such as sugar beets and maize. This blade usually provides satisfactory weed control, if soils are not too wet and...... weeds are relatively small. The term ‘Ducksfoot’ covers a range of hoe blade configurations where all have some resemblance with the shape of a ducks foot. However, the ‘Ducksfoot’ blade is not an optimal solution for weed control in narrow inter-row spaces. Several disadvantages have been encountered...

  16. 64排探测器CT冠状动脉成像对心肌桥伴冠心病的诊断价值探讨%Diagnositic value of 64 multi-detector rows CT coronary angiography in myocardial bridge and coronal artery disease

    刘静; 周茂义; 杨春波; 李立新; 赵兴圣; 岳奎涛; 邵伟光

    2009-01-01

    目的:探讨64排探测器CT(MDCT)对心肌桥伴冠心病的诊断价值及临床意义.方法:对217例拟诊冠心病(CAD)患者行64MDCT冠状动脉血管成像(CCTA),根据CCTA上冠状动脉的走行部位,诊断47例心肌桥,测最心肌桥的长度、厚度,分析各支粥样斑块性质和狭窄程度,判断血管硬化与心肌桥的关系.结果:64MDCTA发现心肌桥51处/47例,检出率为21.66%;34例位于左前降支中段(66.67%),肌桥长度为5.6~27.6 mm;厚度为0.52~4.8mm;其中22例伴有不同程度的粥样硬化斑块,管腔狭窄<50%者19例.结论:64MDCT冠脉成像可无创性检出心肌桥,显示其MDCT表现特点、邻近血管硬化狭窄等,可为临床治疗提供有价值的信息.

  17. CT of pulmonary emphysema - current status, challenges, and future directions

    Pulmonary emphysema is characterized by irreversible destruction of lung parenchyma. Emphysema is a major contributor to chronic obstructive pulmonary disease (COPD), which by itself is a major cause of morbidity and mortality in the western world. Computed tomography (CT) is an established method for the in-vivo analysis of emphysema. This review first details the pathological basis of emphysema and shows how the subtypes of emphysema can be characterized by CT. The review then shows how CT is used to quantify emphysema, and describes the requirements and foundations for quantification to be accurate. Finally, the review discusses new challenges and their potential solution, notably focused on multi-detector-row CT, and emphasizes the open questions that future research on CT of pulmonary emphysema will have to address. (orig.)

  18. CT of blunt pancreatic trauma-A pictorial essay

    Venkatesh, Sudhakar Kundapur [Diagnostic Radiology, National University Hospital, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 119074 (Singapore)], E-mail: dnrskv@nus.edu.sg; Wan, John Mun Chin [Diagnostic Radiology, National University Hospital, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 119074 (Singapore)

    2008-08-15

    Blunt trauma to pancreas is uncommon and clinical features are often non-specific and unreliable leading to possible delays in diagnosis and therefore increased morbidity. CT has been established as the imaging modality of choice for the diagnosis of abdominal solid-organ injury in the blunt trauma patient. The introduction of multidetector-row CT allows for high resolution scans and multiplanar reformations that improve diagnosis. Detection of pancreatic injuries on CT requires knowledge of the subtle changes produced by pancreatic injury. The CT appearance of pancreatic injury ranges from a normal initial appearance of the pancreas to active pancreatic bleeding. Knowledge of CT signs of pancreatic trauma and a high index of suspicion is required in diagnosing pancreatic injury.

  19. Technical principles of dual source CT

    Petersilka, Martin [Siemens Health Care, Forchheim (Germany)], E-mail: martin.petersilka@siemens.com; Bruder, Herbert; Krauss, Bernhard; Stierstorfer, Karl [Siemens Health Care, Forchheim (Germany); Flohr, Thomas G. [Siemens Health Care, Forchheim (Germany); Department of Diagnostic Radiology, Eberhard-Karls-Universitaet, Tuebingen (Germany)

    2008-12-15

    During the past years, multi-detector row CT (MDCT) has evolved into clinical practice with a rapid increase of the number of detector slices. Today's 64 slice CT systems allow whole-body examinations with sub-millimeter resolution in short scan times. As an alternative to adding even more detector slices, we describe the system concept and design of a CT scanner with two X-ray tubes and two detectors (mounted on a CT gantry with a mechanical offset of 90 deg.) that has the potential to overcome limitations of conventional MDCT systems, such as temporal resolution for cardiac imaging. A dual source CT (DSCT) scanner provides temporal resolution equivalent to a quarter of the gantry rotation time, independent of the patient's heart rate (83 ms at 0.33 s rotation time). In addition to the benefits for cardiac scanning, it allows to go beyond conventional CT imaging by obtaining dual energy information if the two tubes are operated at different voltages. Furthermore, we discuss how both acquisition systems can be used to add the power reserve of two X-ray tubes for long scan ranges and obese patients. Finally, future advances of DSCT are highlighted.

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

    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

  1. 心肌桥伴冠心病的64排探测器CT诊断及临床意义%Clinical Significance of 64 Multi-Detector Rows CT Coronary Angiography in Diagnosing Myocardial Bridge and Coronal Artery Disease

    刘静; 周茂义; 杨春波; 李丽新; 赵兴圣; 邵伟光; 岳奎涛

    2008-01-01

    目的 探讨64排螺旋CT(MDCT)对心肌桥的诊断价值及与冠状动脉硬化的关系.方法 对217例拟诊冠心病(CAD)者行64MDCT冠状动脉血管成像(CCTA),采用回顾性心电门控扫描,获取最大密度投影、曲面重组、容积重组图像,诊断51处/47例心肌桥.测量肌桥的长度、厚度,分析各支粥样斑块性质和狭窄程度,判断血管硬化与心肌桥的关系.纳果 64MDCTA发现心肌桥51处/47例检出率为21.66%;肌桥位于左前降支者66.67%(34/51),心肌桥长度为5.6~27.6(15.3±8.6)mm;厚度为0.52~4.8(1.8±1.3)mm;22例可见血管硬化并狭窄征象,其中发生于前降支中段的34处中,13例近段管腔伴有不同程度的粥样硬化斑块和狭窄,管腔狭窄<50%者11例(32.35%),>50%2例.结论 64排螺旋CT冠状动脉血管成像无创性诊断心肌桥和壁冠状动脉,还可显示壁冠状动脉有无硬化狭窄,可为临床提供心肌缺血的原因和为治疗提供更具价值的信息.

  2. Developmental venous anomalies: appearance on whole-brain CT digital subtraction angiography and CT perfusion

    Hanson, Eric H. [Advanced Medical Imaging and Genetics (Amigenics), Las Vegas, NV (United States); Touro University Nevada College of Osteopathic Medicine, Henderson, NV (United States); University of Nevada Las Vegas, Department of Health Physics and Diagnostic Sciences, 4505 Maryland Parkway, Box 453037, Las Vegas, NV (United States); Amigenics, Inc, Las Vegas, NV (United States); Roach, Cayce J. [Advanced Medical Imaging and Genetics (Amigenics), Las Vegas, NV (United States); University of Nevada Las Vegas, School of Life Sciences, Las Vegas, NV (United States); Ringdahl, Erik N. [University of Nevada Las Vegas, Department of Psychology, Las Vegas, NV (United States); Wynn, Brad L. [Family Medicine Spokane, Spokane, WA (United States); DeChancie, Sean M.; Mann, Nathan D. [Touro University Nevada College of Osteopathic Medicine, Henderson, NV (United States); Diamond, Alan S. [CHW Nevada Imaging Company, Nevada Imaging Centers, Spring Valley, Las Vegas, NV (United States); Orrison, William W. [Touro University Nevada College of Osteopathic Medicine, Henderson, NV (United States); University of Nevada Las Vegas, Department of Health Physics and Diagnostic Sciences, 4505 Maryland Parkway, Box 453037, Las Vegas, NV (United States); CHW Nevada Imaging Company, Nevada Imaging Centers, Spring Valley, Las Vegas, NV (United States); University of Nevada School of Medicine, Department of Medical Education, Reno, NV (United States)

    2011-05-15

    Developmental venous anomalies (DVA) consist of dilated intramedullary veins that converge into a large collecting vein. The appearance of these anomalies was evaluated on whole-brain computed tomography (CT) digital subtraction angiography (DSA) and CT perfusion (CTP) studies. CT data sets of ten anonymized patients were retrospectively analyzed. Five patients had evidence of DVA and five age- and sex-matched controls were without known neurovascular abnormalities. CT angiograms, CT arterial-venous views, 4-D CT DSA and CTP maps were acquired on a dynamic volume imaging protocol on a 320-detector row CT scanner. Whole-brain CTP parameters were evaluated for cerebral blood flow (CBF), cerebral blood volume (CBV), time to peak (TTP), mean transit time (MTT), and delay. DSA was utilized to visualize DVA anatomy. Radiation dose was recorded from the scanner console. Increased CTP values were present in the DVA relative to the unaffected contralateral hemisphere of 48%, 32%, and 26%; and for the control group with matched hemispheric comparisons of 2%, -10%, and 9% for CBF, CBV, and MTT, respectively. Average effective radiation dose was 4.4 mSv. Whole-brain DSA and CTP imaging can demonstrate a characteristic appearance of altered DVA hemodynamic parameters and capture the anomalies in superior cortices of the cerebrum and the cerebellum. Future research may identify the rare subsets of patients at increased risk of adverse outcomes secondary to the altered hemodynamics to facilitate tailored imaging surveillance and application of appropriate preventive therapeutic measures. (orig.)

  3. Developmental venous anomalies: appearance on whole-brain CT digital subtraction angiography and CT perfusion

    Developmental venous anomalies (DVA) consist of dilated intramedullary veins that converge into a large collecting vein. The appearance of these anomalies was evaluated on whole-brain computed tomography (CT) digital subtraction angiography (DSA) and CT perfusion (CTP) studies. CT data sets of ten anonymized patients were retrospectively analyzed. Five patients had evidence of DVA and five age- and sex-matched controls were without known neurovascular abnormalities. CT angiograms, CT arterial-venous views, 4-D CT DSA and CTP maps were acquired on a dynamic volume imaging protocol on a 320-detector row CT scanner. Whole-brain CTP parameters were evaluated for cerebral blood flow (CBF), cerebral blood volume (CBV), time to peak (TTP), mean transit time (MTT), and delay. DSA was utilized to visualize DVA anatomy. Radiation dose was recorded from the scanner console. Increased CTP values were present in the DVA relative to the unaffected contralateral hemisphere of 48%, 32%, and 26%; and for the control group with matched hemispheric comparisons of 2%, -10%, and 9% for CBF, CBV, and MTT, respectively. Average effective radiation dose was 4.4 mSv. Whole-brain DSA and CTP imaging can demonstrate a characteristic appearance of altered DVA hemodynamic parameters and capture the anomalies in superior cortices of the cerebrum and the cerebellum. Future research may identify the rare subsets of patients at increased risk of adverse outcomes secondary to the altered hemodynamics to facilitate tailored imaging surveillance and application of appropriate preventive therapeutic measures. (orig.)

  4. Method for Automatic Tube Current Selection for Obtaining a Consistent Image Quality and Dose Optimization in a Cardiac Multidetector CT

    Qi, Weiwei; Li, Jianying; Du, Xiangke

    2009-01-01

    Objective To evaluate a quantitative method for individually adjusting the tube current to obtain images with consistent noise in electrocardiogram (ECG)-gated CT cardiac scans. Materials and Methods The image noise from timing bolus and cardiac CT scans of 80 patients (Group A) who underwent a 64-row multidetector (MD) CT cardiac examination with patient-independent scan parameters were analyzed. A formula was established using the noise correlation between the timing bolus and cardiac scans...

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

    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 < 5 mm was 64% higher in ECG-triggered scans. The median demarcation rating of all pulmonary findings was 2 for ECG-MDR-CT and 3 for MDR-CT. The median demarcation rating of tumors < 5 mm was 3 for ECG-MDR-CT and 4 for MDR-CT. Mediastinal structures were better delineated by ECG-triggering. The median demarcation rating of the vessels and left bronchus was 2 for ECG-MDR-CT and 4 for MDR-CT. Detection rate and demarcation rating of pulmonary tumors and the delineation of mediastinal structures were not significant different for either CT technique. Conclusion: Our study indicates superiority for ECG-MDR-CT. (orig.)

  6. Outbreak of Salmonella food poisoning at Junior World Rowing Championships.

    Anderson, A C

    1996-01-01

    This paper describes an outbreak of Salmonella enteriditis occurring at the Junior World Rowing Championships at Poznan, Poland, in August 1995 which was to have a significant effect on the performance of several of the largest national teams.

  7. Comparison of Exercise Performance on Rowing and Cycle Ergometers.

    Mahler, Donald A.; And Others

    1987-01-01

    The purpose of this study was to compare exercise performance and cardiorespiratory responses on the rowing ergometer with those on the cycle ergometer. Findings are presented and explained. (Author/MT)

  8. Computed Tomography (CT) -- Head

    Full Text Available ... News Physician Resources Professions Site Index A-Z Computed Tomography (CT) - Head What is CT Scanning of the ... Head? What is CT Scanning of the Head? Computed tomography, more commonly known as a CT or CAT ...

  9. Computed Tomography (CT) -- Sinuses

    Full Text Available ... News Physician Resources Professions Site Index A-Z Computed Tomography (CT) - Sinuses What is CT (Computed Tomography) of ... of CT of the Sinuses? What is CT (Computed Tomography) of the Sinuses? Computed tomography, more commonly known ...

  10. Cervical spine CT scan

    ... cervical spine; Computed tomography scan of cervical spine; CT scan of cervical spine; Neck CT scan ... Risks of CT scans include: Being exposed to radiation Allergic reaction to contrast dye CT scans expose you to more radiation than ...

  11. Computed Tomography (CT) -- Sinuses

    ... Physician Resources Professions Site Index A-Z Computed Tomography (CT) - Sinuses Computed tomography (CT) of the sinuses ... CT of the Sinuses? What is CT (Computed Tomography) of the Sinuses? Computed tomography, more commonly known ...

  12. Computed Tomography (CT) -- Head

    ... Physician Resources Professions Site Index A-Z Computed Tomography (CT) - Head Computed tomography (CT) of the head uses special x-ray ... What is CT Scanning of the Head? Computed tomography, more commonly known as a CT or CAT ...

  13. Computed Tomography (CT) -- Sinuses

    Full Text Available ... Physician Resources Professions Site Index A-Z Computed Tomography (CT) - Sinuses Computed tomography (CT) of the sinuses ... CT of the Sinuses? What is CT (Computed Tomography) of the Sinuses? Computed tomography, more commonly known ...

  14. Soft tissue imaging with photon counting spectroscopic CT

    Shikhaliev, Polad M.

    2015-03-01

    The purpose of this work was experimental investigation of photon counting spectroscopic CT (PCS-CT) imaging of anatomical soft tissue with clinically relevant size. The imaging experiments were performed using a spectroscopic CT system based on CdZnTe photon counting detector with two rows of pixels, 256 pixels in each row, 1  ×  1 mm2 pixel size, and 25.6 cm detector length. The detector could split the x-ray energy spectrum to 5 regions (energy bins), and acquire 5 multi-energy (spectroscopic) CT images in a single CT scan. A sample of round shaped anatomical soft tissue of 14 cm diameter including lean and fat was used for imaging. To avoid the negative effect of anatomical noise on quantitative analysis, a spectroscopic CT phantom with tissue equivalent solid materials was used. The images were acquired at 60, 90, and 120 kVp tube voltages, and spectroscopic image series were acquired with 3 and 5 energy bins. Spectroscopic CT numbers were introduced and used to evaluate an energy selective image series. The anatomical soft tissue with 14 cm diameter was visualized with good quality and without substantial artifacts by the photon counting spectroscopic CT system. The effects of the energy bin crosstalk on spectroscopic CT numbers were quantified and analyzed. The single and double slice PCS-CT images were acquired and compared. Several new findings were observed, including the effect of soft tissue non-uniformity on image artifacts, unique status of highest energy bin, and material dependent visualization in spectroscopic image series. Fat-lean decomposition was performed using dual energy subtraction and threshold segmentation methods, and compared. Using K-edge filtered x-rays improved fat-lean decomposition as compared to conventional x-rays. Several new and important aspects of the PCS-CT were investigated. These include imaging soft tissue with clinically relevant size, single- and double-slice PCS-CT imaging, using spectroscopic CT

  15. Comparative evaluation of multidetector CT and MR imaging in the differentiation of adnexal masses

    The purpose was to compare the accuracy of multidetector CT (MDCT) on a 16-row CT scanner and magnetic resonance (MR) imaging in the characterization of ovarian masses. Preoperative CT examination of the abdomen and MR imaging of the pelvis was performed in 67 women, with clinically or sonographically detected adnexal masses. The CT examinations were performed on a 16-row CT scanner, and the protocol included scanning of the abdomen during the portal phase, using a detector collimation of 16 x 0.75 mm and a pitch of 1.2. We used a 1.5-T magnet unit to perform T1, T2 and fat-suppressed T1-weighted sequences, before and after intravenous administration of gadolinium chelate compounds. The accuracy of multidetector CT and MR imaging in the differentiation between benign and malignant ovarian masses was evaluated, using histopathologic results as the standard of reference. The sensitivity, specificity and accuracy of MDCT in the characterization of ovarian masses were 90.5%, 93.7% and 92.9%, respectively, and that of MR imaging 95.2%, 98.4% and 97.6%, respectively. Although MRI performed slightly better, this did not reach statistical significance. In conclusion, both MDCT on a 16-row CT scanner and MR imaging demonstrated satisfactory results in the characterization of ovarian masses. (orig.)

  16. Hydrodynamic performance of multiple-row slotted breakwaters

    Elbisy, Moussa S.; Mlybari, Ehab M.; Helal, Medhat M.

    2016-06-01

    This study examines the hydrodynamic performance of multiple-row vertical slotted breakwaters. We developed a mathematical model based on an eigenfunction expansion method and a least squares technique for Stokes second-order waves. The numerical results obtained for limiting cases of double-row and triple-row walls are in good agreement with results of previous studies and experimental results. Comparisons with experimental measurements of the reflection, transmission, and dissipation coefficients ( C R , C T , and C E ) for double-row walls show that the proposed mathematical model adequately reproduces most of the important features. We found that for double-row walls, the C R increases with increasing wave number, kd, and with a decreasing permeable wall part, dm. The C T follows the opposite trend. The C E slowly increases with an increasing kd for lower kd values, reaches a maximum, and then decreases again. In addition, an increasing porosity of dm would significantly decrease the C R , while increasing the C T . At lower values of kd, a decreasing porosity increases the C E , but for high values of kd, a decreasing porosity reduces the C E . The numerical results indicate that, for triple-row walls, the effect of the arrangement of the chamber widths on hydrodynamic characteristics is not significant, except when kd0.5, where by the horizontal wave force may be smaller than that of a single wall. On the other hand, the difference between double-row and triple-row vertical slotted breakwaters is marginal.

  17. Analysis of indoor rowing motion using wearable inertial sensors

    Bosch, Stephan; Shoaib, Muhammad; Geerlings, Stephen; Buit, Lennart; Meratnia, Nirvana; Havinga, Paul

    2015-01-01

    In this exploratory work the motion of rowers is analyzed while rowing on a rowing machine. This is performed using inertial sensors that measure the orientation at several positions on the body. Using these measurements, this work provides a preliminary analysis of the differences between experienced and novice rowers, or between a good and a bad technique. The analysis shows that the measured postural angles show no clear trend that would set apart experienced and novice rowers or a bad and...

  18. Incarceration on Death Row: A Microcosm of Communication?

    Pettigrew, Mark

    2013-01-01

    Death row is a space across the United States that continues to expand, not only in numbers, but in the length of time inmates spend confined there. Fewer and fewer inmates are executed and death row is now increasingly the only punishment of capital convicts. This thesis examines the retributive and punitive treatment of death-sentenced offenders within that space and, by viewing that form of imprisonment as part of a communication process, it assesses the contribution it makes to the death ...

  19. QR factorization for row or column symmetric matrix

    ZOU; Hongxing(邹红星); WANG; Dianjun(王殿军); DAI; Qionghai(戴琼海); LI; Yanda(李衍达)

    2003-01-01

    The problem of fast computing the QR factorization of row or column symmetric matrix isconsidered. We address two new algorithms based on a correspondence of Q and R matrices between the rowor column symmetric matrix and its mother matrix. Theoretical analysis and numerical evidence show that, fora class of row or column symmetric matrices, the QR factorization using the mother matrix rather than therow or column symmetric matrix per se can save dramatically the CPU time and memory without loss of anynumerical precision.

  20. Clontarf to Curtin: Row AHEAD and Tertiary Affinity

    Cameron Thorn; Charles Flodin

    2015-01-01

    In Western Australia, and around the world, rowing is a sport that is often associated with elite private schools and tertiary institutions (Cambridge University Boat Club, 2013; Yale Athletics, 2010; Oxford University Boat Club, 2015; Melbourne University Boat Club, 2015). Events like the Boat Race, an annual rowing event for the top Oxford and Cambridge University crews, and the Henley Royal Regatta, held on the Thames River since 1839, serve to reinforce the elitist history of the sport. I...

  1. Exploratory analysis on the binaural characteristics of the rowing sound

    Hoffmann, Pablo F.; Hammershøi, Dorte; Ruffaldi, Emanuele;

    2011-01-01

    Differences between the signals captured at the entrances to the left and right ears are generally quantified by interaural time differences (ITDs), interaural level differences (ILDs) and interaural crosscorrelation (IC). Here, we attempt to gain knowledge on the changes of these interaural param...... parameters during rowing and to evaluate their potential as source of information to determine rowing expertise exclusively from acoustic signals....

  2. Exploratory analysis on the binaural characteristics of the rowing sound

    Fillipeschi Alessandro

    2011-12-01

    Full Text Available Differences between the signals captured at the entrances to the left and right ears are generally quantified by interaural time differences (ITDs, interaural level differences (ILDs and interaural crosscorrelation (IC. Here, we attempt to gain knowledge on the changes of these interaural parameters during rowing and to evaluate their potential as source of information to determine rowing expertise exclusively from acoustic signals.

  3. Evaluation of multimodal feedback effects on improving rowing competencies

    Korman Maria; Ruffaldi Emanuele; Gopher Daniel; Filippeschi Alessandro; Shorr Yifat

    2011-01-01

    This study focused on the selection and preliminary evaluation of different types of modal and information feedback in virtual environment to facilitate acquisition and transfer of a complex motor-cognitive skill of rowing. Specifically, we addressed the effectiveness of immediate information feedback provided visually as compared to sensory haptic feedback on the improvement in hands kinematics and changes in cognitive load during the course of learning the basic rowing technique. Several pi...

  4. New measuring and on water coaching device for rowing

    Mattes, Klaus; Schaffert, Nina

    2010-01-01

    This article presents a new measuring and on water coaching device for rowing called “Accrow” which measures the boat acceleration with an acceleration sensor (50 Hz) and boat velocity with GPS (4 Hz). The data were analysed with the special software “Regatta”, based on scientific criteria and broad knowledge in biomechanical analysis of rowing training and races. In particular, “Regatta” performs three special analysis routines including every stroke: the boat motion for on-water training or...

  5. Traumatic Lumbar Artery Arteriovenous Fistula: Preclinically Detected by 16-Multidetector-Row Computed Tomography and Post-processing Techniques

    Chou, C.P.; Pan, H.B.; Wu, T.H.; Huang, F.D.; Wu, M.T. [Dept. of Radiology, Dept. of Vascular Surgery, and Dept. of Emergency, Kaohsiung Veterans General Hospital, Kaohsiung, Taiwan (China); National Yang-Ming Univ. School of Medicine, Taipei, Taiwan (China)

    2007-04-15

    We report a 21-year-old woman with a penetrating abdominal wound. Injuries of the abdominal aorta and alimentary tract were found during emergency surgery. The patient had a follow-up computed tomography (CT) scan 3 months after surgery. Arterial-phase 16-row multidetector computed tomography (MDCT) showed a suspicious dilated vessel adjacent to the repaired aorta on 5-mm transverse images. A fistula between a lumbar artery and the inferior vena cava was clearly demonstrated on images reformatted with two- (2D) and three-dimensional (3D) techniques. The patient suffered from symptoms of high-output heart failure 8 months after surgery.

  6. 16排螺旋CT胆道及血管造影在肝门部胆管癌可切除性术前评估中的应用%Preoperative evaluation in resectability of Klatskin tumor with 16-row spiral CT cholangiography and angiography

    陈焕伟; 潘爱珍; 陈涛; 廖珊; 甄作均

    2010-01-01

    目的 通过16排螺旋CT血管和胆管造影检查,对肝门部胆管癌的可切除性进行前瞻性术前评估,评价其临床应用价值.方法 从2002年1月至2009年1月,笔者对75例经影像学检查诊断为肝门部胆管癌的病人于术前进行了CT直接胆道造影和血管造影检查,并通过VR、MPR、MIP技术三维重建肝动脉、门静脉及胆道系统.然后根据肿瘤与肝门部重要血管及胆管的关系,进行Bismuth-Corlette分型和T分期,并对肝门部胆管癌可切除性进行术前评估.最后将术前评估结果 与手术探查结果 进行对照分析.结果 所有病人均能耐受CT检查,其评估门静脉受侵犯的敏感性、特异性和准确性分别为92.9%,100%和96%,评估肝动脉受侵犯的敏感性、特异性和准确性分别为83.3%、100%和93.3%.按Bismuth-Corlette分型标准,其判断肿瘤浸润胆道范围的准确性为96%;预测肿瘤可切除的敏感性、特异性和准确性分别为95.7%、82.1%和90.7%.结论 术前螺旋CT血管和胆管造影对于判断肝门部胆管癌侵犯血管和胆管具有较高的准确性,有助于预测肝门部胆管癌可切除性.%Objective To evaluate prospectively the preoperative use of 16-multidetector computed tomography (MDCT) with cholangiography and angiography in determining the resectability of hilar cholangiocarcinoma.Methods From January 2002 to January 2009,75 consecutive patients with hilar cholangiocarcinoma underwent preoperative MDCT with cholangiography and angiography.3D images of the portal vein,hepatic artery,and bile ducts were created and viewed simultaneously.The accuracy of MDCT with cholangiography and angiography was determined by comparison with intraoperative and pathologic findings.Results All patients tolerated the CT imaging well.The sensitivity,specificity,and accuracy rates were 92.9%,100%,and 96%for portal invasion and 83.3%,100 %,and 93.3%for hepatic arterialinvasion.The accuracy rate of longitudinal tumor

  7. Comparison between Carotid Artery Wall Thickness Measured by Multidetector Row Computed Tomography Angiography and Intimae-Media Thickness Measured by Sonography

    Živorad N. Savić

    2011-01-01

    Full Text Available The increased thickness of the carotid wall >1 mm is a significant predictor of coronary and cerebrovascular diseases. The purpose of our study was to assess the agreement between multidetector row computed tomography angiography (MDCTA in measuring carotid artery wall thickness (CAWT and color Doppler ultrasound (CD-US in measuring intimae-media thickness (IMT. Eighty-nine patients (aged 35–81 were prospectively analyzed using a 64-detector MDCTA and a CD-US scanner. Continuous data were described as the mean value ± standard deviation, and were compared using the Mann–Whitney U test. A p value <0.05 was considered significant. Bland–Altman statistics were employed to measure the agreement between MDCTA and CD-US. CAWT ranged from 0.62 to 1.60 mm, with a mean value of 1.09 mm. IMT ranged from 0.60 to 1.55 mm, with a mean value of 1.06 mm. We observed an excellent agreement between CD-US and MDCTA in the evaluation of the common carotid artery thickness, with a bias between methods of 0.029 mm (which is a highly statistically important difference of absolute values [t = 43.289; p < 0.01] obtained by paired T test, and limits of agreement from 0.04 to 0.104. Pearson correlation coefficient was 0.9997 (95% CI 0.9996–0.9998; p < 0.01. We conclude that there is an excellent correlation between CAWT and IMT measurements obtained with the MDCTA and CD-US.

  8. Don't Rock the Boat : How Antiphase Crew Coordination Affects Rowing

    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

  9. Dad Vail Regatta, 52 on the Schuylkill, Is the World's Biggest College Rowing Event.

    Farrell, Charles S.

    1986-01-01

    The Dad Vail Regatta, the world's largest intercollegiate rowing regatta, attracted teams from 73 colleges in 1986 in a broad-based competition, requiring women to row the same race that men row. It is evidence of a growing interest in rowing as an intercollegiate sport. (MSE)

  10. A Theoretical Study of Clusters: Realizing Differences between the Second-Row and the Third-Row Elements

    XU Ya-Ge; JI Dong; SHEN Xu-Yang; WANG Xiao-Lu; LI Jia-Ming

    2006-01-01

    @@ Based on the characteristics of valence bonds and the first-principle molecular dynamics simulation we present an optimum valence bond scheme to study properties of important critical clusters with limited computational effort. The differences between the second-row and the third-row elements belonging to the same families can be understood by examining electronic structures and geometric structures even for small size clusters.

  11. Cardiac CT

    Dewey, Marc [Charite - Universitaetsmedizin Berlin (Germany). Inst. fuer Radiologie

    2011-07-01

    Computed tomography of the heart has become a highly accurate diagnostic modality that is attracting increasing attention. This extensively illustrated book aims to assist the reader in integrating cardiac CT into daily clinical practice, while also reviewing its current technical status and applications. Clear guidance is provided on the performance and interpretation of imaging using the latest technology, which offers greater coverage, better spatial resolution, and faster imaging. The specific features of scanners from all four main vendors, including those that have only recently become available, are presented. Among the wide range of applications and issues to be discussed are coronary artery bypass grafts, stents, plaques, and anomalies, cardiac valves, congenital and acquired heart disease, and radiation exposure. Upcoming clinical uses of cardiac CT, such as plaque imaging and functional assessment, are also explored. (orig.)

  12. CT fluoroscopy

    Percutaneous biopsy of pulmonary nodules requires precise needle placement, with the goal of attaining a secure position of the needle for therapeutic or diagnostic purposes as quickly as possible and with minimal tissue damage along the access route. The requirements from the image guidance system during the intervention are, in addition to universal applicability, a quick reaction time and a user-friendly interface. CT fluoroscopy fulfils these requirements, although radiation protection for the patient and radiologist becomes an important issue. (orig.)

  13. [CT fluoroscopy].

    Rogalla, P; Juran, R

    2004-07-01

    Percutaneous biopsy of pulmonary nodules requires precise needle placement, with the goal of attaining a secure position of the needle for therapeutic or diagnostic purposes as quickly as possible and with minimal tissue damage along the access route. The requirements from the image guidance system during the intervention are, in addition to universal applicability, a quick reaction time and a user-friendly interface. CT fluoroscopy fulfils these requirements, although radiation protection for the patient and radiologist becomes an important issue. PMID:15232690

  14. Low-dose triple-rule-out using 320-row-detector volume MDCT - less contrast medium and lower radiation exposure

    To investigate image quality of triple-rule-out (TRO) computed tomography (CT) using a 320-row-detector CT system with substantially reduced contrast medium volume at 100 kV. Forty-six consecutive patients with noncritical, acute chest pain underwent 320-row-detector CT using a two-step TRO protocol consisting of a non-spiral, non-gated chest CT acquisition (150 mA) followed by a non-spiral, electrocardiography-gated cardiac acquisition (200-500 mA based on body mass index (BMI)). Data were acquired using a biphasic injection protocol with a total iodinated contrast medium volume of 60 ml (370 mg/ml). Vessel attenuation and effective doses were recorded. Image quality was scored independently by two readers. Mean attenuation was 584 ± 114 Hounsfield units (HU) in the ascending aorta, 335 ± 63HU in the aortic arch, 658 ± 136HU in the pulmonary trunk, and 521 ± 97HU and 549 ± 102HU in the right and left coronary artery, respectively. In all but one patient, attenuation and image quality allowed accurate visualization of the pulmonary arteries, thoracic aorta, and coronary arteries in a single examination. Ninety-six percent of all coronary artery segments were rated diagnostic. Radiation exposure ranged between 2.0 and 3.3 mSv. Using 320-row-detector CT the investigated low-dose TRO protocol resulted in excellent opacification and image quality with substantial reduction of contrast medium volume compared to recently published TRO protocols. (orig.)

  15. On the origin of Spanish two-rowed barleys.

    Moralejo, M; Romagosa, I; Salcedo, G; Sánchez-Monge, R; Molina-Cano, J L

    1994-02-01

    To investigate the phylogenetic origin of Spanish two-rowed barleys, we studied 44 accessions of old land-races both morphologically and biochemically to ascertain their similarity with 51 entries of old cultivars and land-races of widespread origin across Europe. They were also compared with 20 accessions of Hordeum spontaneum from the Mediterranean basin and other regions of its distribution range, 14 accessions of Moroccan cultivated six-rowed barley land-races, and different six-rowed Spanish and two-and six-rowed European cultivars. CM-(trypsin inhibitors and subunits of the barley tetrameric α-amylase inhibitor) proteins and hordeins, all of which are endosperm proteins, were used as biochemical markers. The appearance of separate clusters of the Spanish barleys in the numerical classifications for both protein systems as a result of the existence of characteristic gene combinations that do not exist in entries from other origins permitted us to postulate the existence of local ancestors for most of the Spanish two-rowed barleys studied, and, therefore, a possible in situ domestication. PMID:24190469

  16. Influence of Ergometer Design on Physiological Responses during Rowing.

    Rossi, J; Piponnier, E; Vincent, L; Samozino, P; Messonnier, L

    2015-11-01

    The aim of this study was to compare the physiological responses and rowing efficiency on 2 different rowing ergometers: stationary vs. dynamic ergometers manufactured by Concept2. 11 oarswomen and oarsmen rowed 4 min at 60% and 70% of peak power output on both ergometers (randomized order). Power output, stroke rate, heart rate, oxygen uptake, carbon dioxide production, lactate accumulation and rating of perceived exertion were recorded at each stage on the 2 ergometers. Gross and net efficiencies were computed. Exercise intensity was associated with increases in all parameters. Rowing on dynamic ergometer was associated with higher heart rate, oxygen uptake, carbon dioxide production and stroke rate, concomitantly to lower blood lactate accumulation but also to lower gross and net efficiencies. The present study showed that rowing efficiency and blood lactate accumulation were lower on the Concept2 dynamic ergometer than on its stationary counterpart. If the use of the Concept2 dynamic ergometer may provide some advantages (reduced risk of injuries), its utilization requires a specific evaluation of physiological responses during an incremental exercise for an adapted management of training. PMID:26212249

  17. Ultra-High-Resolution Computed Tomography of the Lung: Image Quality of a Prototype Scanner

    Kakinuma, Ryutaro; Moriyama, Noriyuki; Muramatsu, Yukio; Gomi, Shiho; Suzuki, Masahiro; Nagasawa, Hirobumi; Kusumoto, Masahiko; Aso, Tomohiko; Muramatsu, Yoshihisa; Tsuchida, Takaaki; Tsuta, Koji; Maeshima, Akiko Miyagi; Tochigi, Naobumi; Watanabe, Shun-ichi; SUGIHARA, Naoki

    2015-01-01

    Purpose: The image noise and image quality of a prototype ultra-high-resolution computed tomography (U-HRCT) scanner was evaluated and compared with those of conventional high-resolution CT (C-HRCT) scanners. Materials and Methods: This study was approved by the institutional review board. A U-HRCT scanner prototype with 0.25 mm × 4 rows and operating at 120 mAs was used. The C-HRCT images were obtained using a 0.5 mm × 16 or 0.5 mm × 64 detector-row CT scanner operating at 150 mAs. Images fr...

  18. Ultra-High-Resolution Computed Tomography of the Lung: Image Quality of a Prototype Scanner

    Ryutaro Kakinuma; Noriyuki Moriyama; Yukio Muramatsu; Shiho Gomi; Masahiro Suzuki; Hirobumi Nagasawa; Masahiko Kusumoto; Tomohiko Aso; Yoshihisa Muramatsu; Takaaki Tsuchida; Koji Tsuta; Akiko Miyagi Maeshima; Naobumi Tochigi; Shun-Ichi Watanabe; Naoki Sugihara

    2015-01-01

    Purpose The image noise and image quality of a prototype ultra-high-resolution computed tomography (U-HRCT) scanner was evaluated and compared with those of conventional high-resolution CT (C-HRCT) scanners. Materials and Methods This study was approved by the institutional review board. A U-HRCT scanner prototype with 0.25 mm x 4 rows and operating at 120 mAs was used. The C-HRCT images were obtained using a 0.5 mm x 16 or 0.5 mm x 64 detector-row CT scanner operating at 150 mAs. Images from...

  19. Screening for Carotid Injury in Trauma Patients: Image Quality of 16-Detector-Row Computed Tomography Angiography

    Background: The introduction of multidetector-row computed tomography (MDCT) has revolutionized the initial management of multiply injured patients. This technology has the potential to improve the imaging of traumatic vascular injuries. Purpose: To evaluate the quality of multidetector-row computed tomography angiography (MDCTA) of the carotid arteries in the setting of a routine whole-body trauma scan. Material and Methods: 87 trauma patients underwent a routine whole-body CT scan in a 16-detector-row scanner including an MDCTA with a reconstructed axial slice thickness of 3 mm. Images were reviewed by three experienced radiologists with emphasis on image quality. Contrast density, severity, and origin of artifacts and the occurrence of vessel lesions were assessed for different vessel segments. Results: 3642 separate vessel segments were evaluated. Contrast density was rated good or sufficient for diagnosis in 99.8%. A total of 67.3% of vessel segments were free of artifacts, while 27.9% of vessel segments showed minor artifacts not impairing diagnostic evaluation. Clinically relevant artifacts obscuring a vessel segment occurred in 4.7% and were mostly caused by dental hardware. Four dissections of the internal carotid artery were diagnosed by all three radiologists. Conclusion: As a rapid screening test for blunt carotid artery injury, integration of MDCTA in the routine imaging workup of trauma patients utilizing a whole-body CT trauma scan is possible and practicable. Image quality is mostly sufficient for diagnosis, but impaired in a few cases by artifacts deriving primarily from dental hardware

  20. Screening for Carotid Injury in Trauma Patients: Image Quality of 16-Detector-Row Computed Tomography Angiography

    Borisch, I.; Boehme, T.; Butz, B.; Hamer, O.W.; Feuerbach, S.; Zorger, N. [Dept. of Diagnostic Radiology, Univ. Hospital Regensburg, Regensburg (Germany)

    2007-09-15

    Background: The introduction of multidetector-row computed tomography (MDCT) has revolutionized the initial management of multiply injured patients. This technology has the potential to improve the imaging of traumatic vascular injuries. Purpose: To evaluate the quality of multidetector-row computed tomography angiography (MDCTA) of the carotid arteries in the setting of a routine whole-body trauma scan. Material and Methods: 87 trauma patients underwent a routine whole-body CT scan in a 16-detector-row scanner including an MDCTA with a reconstructed axial slice thickness of 3 mm. Images were reviewed by three experienced radiologists with emphasis on image quality. Contrast density, severity, and origin of artifacts and the occurrence of vessel lesions were assessed for different vessel segments. Results: 3642 separate vessel segments were evaluated. Contrast density was rated good or sufficient for diagnosis in 99.8%. A total of 67.3% of vessel segments were free of artifacts, while 27.9% of vessel segments showed minor artifacts not impairing diagnostic evaluation. Clinically relevant artifacts obscuring a vessel segment occurred in 4.7% and were mostly caused by dental hardware. Four dissections of the internal carotid artery were diagnosed by all three radiologists. Conclusion: As a rapid screening test for blunt carotid artery injury, integration of MDCTA in the routine imaging workup of trauma patients utilizing a whole-body CT trauma scan is possible and practicable. Image quality is mostly sufficient for diagnosis, but impaired in a few cases by artifacts deriving primarily from dental hardware.

  1. Comparisons of solar radiation interception, albedo and net radiation as influenced by row orientations of crops

    Field experiments were conducted on soybean (Glycin max L.) in summer and potato (Solanum tuberosum L.) in autumn to evaluate the effect of row orientations of crops on some selected micro meteorological factors during 1994 and 1995. The intercepted solar radiation was the largest in the plants growing in bidirection in summer and it exhibited intermediate trend in autumn as compared to E-W or N-S row orientations. In summer, penetrated solar radiation between two plants and near the stem base of a N-S row was larger than that of E-W row. While in autumn, the observed solar radiation between two plants and near the stem base of a E-W row was markedly larger than that of N-S row. The area weighted mean of penetrated solar radiation was larger in E-W soybean rows but lower in potato rows as compared to N-S row orientations. Soil surface temperature between N-S potato rows was larger than that of E-W potato rows and the upper canopy surface temperature of potato was larger in E-W rows as compared to N-S rows. Net radiation observed over E-W potato rows was larger as compared to N-S potato rows but net radiation measured under canopy of E-W potato rows was smaller than that of in N-S rows. Net radiation measured over N-S soybean rows was larger than that of E-W soybean rows and it was smaller between N-S soybean rows when measured under canopy as compared to E-W rows. The albedo observed over potato was larger over E-W rows as compared to N-S rows. Albedos over soybean canopy showed opposite trend with the albedos observed over potato canopy. It was larger over N-S rows as compared to E-W rows. High harvest index was associated with larger interception of radiation. (author)

  2. Nutrition and Supplements for Elite Open-Weight Rowing.

    Boegman, Susan; Dziedzic, Christine E

    2016-01-01

    Competitive rowing events are raced over 2,000 m requiring athletes to have highly developed aerobic and anaerobic systems. Elite rowers therefore undertake training sessions focused on lactate tolerance, strength and power as well as aerobic and anaerobic capacity development, that can amount to a 24-h training week. The training stimuli and consequent metabolic demands of each session in a rowing training program differ depending on type, length, and intensity. Nutrition guidelines for endurance- and power-based sports should be drawn upon; however, individualized and flexible nutrition plans are critical to successfully meet the daily, weekly, and cyclic nutrient requirements of a rower. This review will provide an overview of key nutritional strategies to optimize training and enhance adaptation, and briefly discuss supplement strategies that may support health and enhance performance in elite rowing. PMID:27399822

  3. Numerical study of rowing hydrofoil performance at low Reynolds numbers

    Chung, M.-H.

    2008-04-01

    In this paper, the hydrodynamic performance of a 2-D flat-plate hydrofoil in rowing motion is numerically studied by a Cartesian grid method with the cut-cell approach. Adaptive mesh refinement is used to save on the number of mesh cells without harming spatial resolution in critical regions. The rowing kinematics of the hydrofoil is the same for all simulations in this work. The design parameters studied are the reduced frequency of the rowing motion, the heave amplitude, and the time lags of the feathered-to-broadside rotation and the broadside-to-feathered rotation. Results show that larger thrust and efficiency can be attained if the feathered-to-broadside rotation is started right after the beginning of the power stroke and the broadside-to-feathered rotation is finished right before the end of the power stroke. Finally, both the thrust and the efficiency increase with Reynolds number.

  4. A parallelization of the row-searching algorithm

    Yaici, Malika; Khaled, Hayet; Khaled, Zakia; Bentahar, Athmane

    2012-11-01

    The problem dealt in this paper concerns the parallelization of the row-searching algorithm which allows the search for linearly dependant rows on a given matrix and its implementation on MPI (Message Passing Interface) environment. This algorithm is largely used in control theory and more specifically in solving the famous diophantine equation. An introduction to the diophantine equation is presented, then two parallelization approaches of the algorithm are detailed. The first distributes a set of rows on processes (processors) and the second makes a distribution per blocks. The sequential algorithm and its two parallel forms are implemented using MPI routines, then modelled using UML (Unified Modelling Language) and finally evaluated using algorithmic complexity.

  5. Evaluation of the CT dose index for scans with an ECG using a 320-row multiple-detector CT scanner

    The relationship between heart rate (HR) and computed tomography dose index (CTDI) was evaluated using an electrocardiogram (ECG) gate scan for scan applications such as prospective triggering, Ca scoring, target computed tomography angiography (CTA), prospective CTA and retrospective gating, continuous CTA/CFA (cardiac functional analysis) and CTA/CFA modulation. Even in the case of a volume scan, doses for the multiple scan average dose were similar to those for CTDI. Moreover, it was found that the ECG gate scan yields significantly different doses. When selecting the optimum scan, the doses were dependent on many factors such as HR, scan rotation time, active time, pre-specified cardiac phase and modulation rate. Therefore, it is necessary to take these results into consideration when selecting the scanning parameters. (authors)

  6. Clontarf to Curtin: Row AHEAD and Tertiary Affinity

    Cameron Thorn

    2015-10-01

    Full Text Available In Western Australia, and around the world, rowing is a sport that is often associated with elite private schools and tertiary institutions (Cambridge University Boat Club, 2013; Yale Athletics, 2010; Oxford University Boat Club, 2015; Melbourne University Boat Club, 2015. Events like the Boat Race, an annual rowing event for the top Oxford and Cambridge University crews, and the Henley Royal Regatta, held on the Thames River since 1839, serve to reinforce the elitist history of the sport. In a more local context, rowing in Western Australia is predominantly facilitated by a number of high-fee-paying secondary schools running their own competitions for male and female students throughout the year. Despite the majority of these schools supporting Indigenous students via full academic and boarding scholarships, it is estimated that a maximum of 20 Indigenous students have participated in rowing in some way over the past 10 years. On a national level, Indigenous participation is estimated to be about 0.01% (L. Callier, pers. comm. May 8, 2014. The program designers believed it was worth noting that Indigenous higher education students make up around 2% of the national higher education student body (Australian Bureau of Statistics, 2011. The designers believed that these participation rates were worth highlighting, given the historical development of the sport of rowing, and could add value to the delivery of the program and narrative of the participant journey, resulting from an increase in engagement. A program was designed to engage Indigenous students in the sport of rowing, and support them through an aspiration and awareness-raising curriculum.

  7. Simulation Of Seed Distribution Uniformity In Row On Seeding Machines

    TAŞER, Ö. Faruk

    1996-01-01

    : In this research, it was determined the uniformity of seed distribution in row on the machines by using a simulation programme which made for this purpose. It was tested the truth of simulation programme by the applications of seeding in row. It was conducted the applications of controling in a closed area and it was made seeding machine constant and stick band system active. In the control applications, lentil seeds were used and application paramétrés were accepted on two different types...

  8. Murphy elements from the double-row transfer matrix

    We consider the double-row (open) transfer matrix constructed from generic tensor-type representations of Hecke algebras of various types. For different choices of boundary conditions for the relevant integrable lattice model we express the double-row transfer matrix solely in terms of generators of the corresponding Hecke algebra (tensor-type realizations). We then expand the open transfer matrix and extract the associated Murphy elements from the first/last terms of the expansion. Suitable combinations of the Murphy elements, as has been shown, commute with the corresponding Hecke algebra. (letter)

  9. Generalized Row-Action Methods for Tomographic Imaging

    Andersen, Martin Skovgaard; Hansen, Per Christian

    2014-01-01

    Row-action methods play an important role in tomographic image reconstruction. Many such methods can be viewed as incremental gradient methods for minimizing a sum of a large number of convex functions, and despite their relatively poor global rate of convergence, these methods often exhibit fast...... initial convergence which is desirable in applications where a low-accuracy solution is acceptable. In this paper, we propose relaxed variants of a class of incremental proximal gradient methods, and these variants generalize many existing row-action methods for tomographic imaging. Moreover, they allow...

  10. Evaluation of multimodal feedback effects on improving rowing competencies

    Korman Maria

    2011-12-01

    Full Text Available This study focused on the selection and preliminary evaluation of different types of modal and information feedback in virtual environment to facilitate acquisition and transfer of a complex motor-cognitive skill of rowing. Specifically, we addressed the effectiveness of immediate information feedback provided visually as compared to sensory haptic feedback on the improvement in hands kinematics and changes in cognitive load during the course of learning the basic rowing technique. Several pilot experiments described in this report lead to the evaluation and optimization of the training protocol, to enhance facilitatory effects of adding visual and haptic feedback during training.

  11. Assessment of myocardial perfusion and viability from routine contrast-enhanced 16-detector-row computed tomography of the heart: preliminary results

    To assess the diagnostic accuracy of 16-detector-row computed tomography (16DCT) of the heart in the assessment of myocardial perfusion and viability in comparison to stress perfusion magnetic resonance imaging (SP-MRI) and delayed-enhancement magnetic resonance imaging (DE-MRI). A number of 30 patients underwent both 16DCT and MRI of the heart. Contrast-enhanced 16DCT data sets were reviewed for areas of myocardium with reduced attenuation. Both CT and MRI data were examined by independent reviewers for the presence of myocardial perfusion defects or myocardial infarctions (MI). Volumetric analysis of the hypoperfusion areas in CT and the infarct sizes in DE-MRI were performed. According to MRI, myocardial infarctions were detected in 11 of 30 cases, and perfusion defects not corresponding to an MI were detected in six of 30 patients. CTA was able to detect ten of 11 MI correctly (sensitivity 91%, specificity 79%, accuracy 83%), and detected three of six hypoperfusions correctly (sensitivity 50%, specificity 92%, accuracy 79%). Assessing the volume of perfusion defects correlating to history of MI on the CT images, a systematic underestimation of the true infarct size as compared to the results of DE-MRI was found (P<0.01). Routine, contrast-enhanced 16-detector row CT of the heart can detect chronic myocardial infarctions in the majority of cases, but ischemic perfusion defects are not reliably detected under resting conditions. (orig.)

  12. Computed Tomography (CT) -- Sinuses

    Full Text Available ... dose technique. top of page What are the limitations of CT of the Sinuses? While CT is ... CT scanner or may be over the weight limit—usually 450 pounds—for the moving table. top ...

  13. Pelvic CT scan

    ... axial tomography scan - pelvis; Computed tomography scan - pelvis; CT scan - pelvis ... Risks of CT scans include: Being exposed to radiation Allergic reaction to contrast dye CT scans do expose you to more radiation ...

  14. Sinus CT scan

    ... axial tomography scan - sinus; Computed tomography scan - sinus; CT scan - sinus ... Risks of a CT scan includes: Being exposed to radiation Allergic reaction to contrast dye CT scans expose you to more radiation than regular ...

  15. Abdominal CT scan

    Computed tomography scan - abdomen; CT scan - abdomen; CAT scan - abdomen; CT abdomen and pelvis ... An abdominal CT scan makes detailed pictures of the structures inside your belly (abdomen) very quickly. This test may be used to ...

  16. Computed Tomography (CT) -- Head

    Full Text Available ... CT is less sensitive to patient movement than MRI. CT can be performed if you have an implanted medical device of any kind, unlike MRI. A diagnosis determined by CT scanning may eliminate ...

  17. Computed Tomography (CT) -- Sinuses

    Full Text Available ... a relatively short time, especially when compared to magnetic resonance imaging (MRI). CT scanning is painless, noninvasive and accurate. A ... CT is less sensitive to patient movement than MRI. CT can be performed if you have an ...

  18. [The features of adults' coronary artery anomalies shown by 64-multi-detector rows CT].

    Yuan, Zhentuan; Yu, Jianqun; Zhang, Youyi; Yuan, Hongmei

    2009-06-01

    To analyze the adults' coronary artery anomalies revealed by 64-MDCT, we retrospectively analyzed 34 cases of coronary artery anomalies (26 males and 8 females, averagely aged 53. 4 years with a range from 30 to 72 years). Multi-plannar reconstruction (MPR), maximum intensity projection (MIP), surface shadow display (SSD) and volume rendering (VR) were used to demonstrate the anomalous coronary artery. We found 4 cases of RCA from the left coronary sinus, 8 cases with secondary RCA, 1 case with high locations of left main (LM) segments from left sinus of valves, 1 case with LAD originated from main pulmonary artery, 3 cases with separate origin of LAD and LCX. Ten cases with myocardial bridge were shown (9 cases in LAD, 1 case in LCX); coronary fistula was seen in 2 cases (one was RCA-RA fistula, another was LAD-RV fistula), coronary aneurysm was found in 2 cases. Three cases in RCA were short and small. In conclusion, 64-MDCT is a good choice for diagnosing the anomalous coronary artery. PMID:19634659

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

    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. Correlative Imaging in a Patient with Cystic Thymoma: CT, MR and PET/CT Comparison

    Cystic thymoma is a rare variant of thymic neoplasm characterized by almost complete cystic degeneration with mixed internal structure. We describe a case of a 60 year-old woman with a cystic thymoma studied with advanced tomographic imaging stydies. CT, MRI and PET/CT with 18F-FDG were performed; volumetric CT and MRI images provided better anatomic evaluation for pre-operative assessment, while PET/CT was helpful for lesion characterization based on 18F-FDG uptake. Although imaging studies are mandatory for pre-operative evaluation of cystic thymoma, final diagnosis still remains surgical. A 60-year-old woman with recent chest pain and no history of previous disease was admitted to our departement to investigate the result of a previous chest X-ray that showed bilateral mediastinal enlargement; for this purpose, enhanced chest CT scan was performed using a 64-rows scanner (Toshiba, Aquilion 64, Japan) before and after intravenous bolus administration of iodinated non ionic contrast agent; CT images demonstrated the presence of a large mediastinal mass (11×8 cm) located in the anterior mediastinum who extended from the anonymous vein to the cardio-phrenic space, compressing the left atrium and causing medium lobe atelectasis; bilateral pleural effusion was also present. In conclusion, correlative imaging plays a foundamental role for the diagnostic evaluation of patient with cystic thymoma. In particular, volumetric CT and MRI studies can provide better anatomic informations regarding internal structure and local tumor spread for pre-operative assessment. Conversely, metabolic imaging using 18F-FDG PET/CT is helpful for lesion characterization differentiating benign from malignant lesion on the basis of intense tracer uptake. The role of PET/MRI is still under investigation. However, final diagnosis still remains surgical even though imaging studies are mandatory for pre-operative patient management

  1. CT colonography with and without butyl scopolamine

    The purpose of this study was to compare colorectal distention with and without butyl scopolamine (Buscopan) during CT colonography. A sixty-four-detector row CT colonography was performed without the administration of butyl scopolamine in 75 subjects (group without buscopan). These subjects were compared to 75 subjects who were premedicated with 20 mg of butyl scopolamine (group with buscopan). The large intestine was divided into six segments, and three observers recorded the degrees of colorectal distention using a 4-point scale for both dual positions (1=completely collapsed, 2=partially collapsed, 3=adequately but not optimally distended, 4=optimally distended). A total of 1,800 segments were evaluated. The average colorectal distention scores for the group without and with buscopan were 3.59 and 3.57, respectively. There was no significant difference between the two groups in terms of colorectal distention (p=0.48). Butyl scopolamine administration before CT colonography does not improve the overall adequacy of colorectal distention and our results do not support its routine use for CT colonography for screening purposes. (author)

  2. CT fluoroscopy; CT-Durchleuchtung

    Rogalla, P.; Juran, R. [Institut fuer Radiologie - Campus Charite Mitte, Universitaetsmedizin Berlin (Germany)

    2004-07-01

    Percutaneous biopsy of pulmonary nodules requires precise needle placement, with the goal of attaining a secure position of the needle for therapeutic or diagnostic purposes as quickly as possible and with minimal tissue damage along the access route. The requirements from the image guidance system during the intervention are, in addition to universal applicability, a quick reaction time and a user-friendly interface. CT fluoroscopy fulfils these requirements, although radiation protection for the patient and radiologist becomes an important issue. (orig.) [German] Die perkutane Punktion von Rundherden in der Lunge erfordert eine praezise Steuerung der Nadel mit dem Ziel, in moeglichst kurzer Zeit unter Schonung des Gewebes entlang des Zugangsweges eine sichere Positionierung der Nadel zur Gewebeentnahme oder Therapie zu erreichen. Die Anforderungen an die Bildsteuerung der Intervention sind neben der universellen Einsetzbarkeit eine schnelle Reaktionszeit der Bildkontrolle und eine flexible Handhabung waehrend der Punktion. Die CT-Durchleuchtung erfuellt diese Anforderungen, wenngleich dem Strahlenschutz fuer Patient und Radiologen eine besondere Bedeutung zukommt. (orig.)

  3. Findings of multidetector row computed tomography of HCCs treated by HIFU ablation

    Purpose: We evaluated the efficacy of high-intensity focused ultrasound (HIFU) ablation for hepatocellular carcinoma (HCC), and a long-term study by follow-up multidetector-row computed tomography (CT) was conducted to evaluate the changes occurring in the treatment area following the HIFU ablation. Materials and methods: HIFU ablation was carried out in 14 patients with small HCCs (≤3 lesions, ≤3 cm in diameter). The HIFU system (Chongqing Haifu Tech) was used under ultrasound guidance. The evaluations were performed by follow-up CT at 1 week, 1, 3, 6 and 12 months after the HIFU ablation. Results: HIFU ablation was carried out successfully in 11 of the 14 patients. At 1 week after the HIFU, a peripheral rim enhancement was found in all cases (100%). This finding was persistent in 6 of the 11 cases (54.5%) at 1 month, and in 1 of the 11 (9%) cases at 3 months after HIFU ablation. In all cases, the rim enhancement disappeared by 6 or 12 months after the HIFU ablation. At the 12 months follow-up, a decrease in the diameter of the ablated lesions was found. The enhancement around the treated area was found to be persistent at the 12 months follow-up in the one case of recurrence of the treated site in which the safety margin was not sufficiently wide. During the follow-up period, there were 2 cases with residual of HCC tumors. We performed radiofrequency ablation (RFA) for these residual tumors after the HIFU ablation. Conclusion: To ascertain the cause of the peripheral enhancement on follow-up CT images after the HIFU ablation, in particular, to determine whether it might be caused by residual tumor or recurrence at the treated site, careful follow-up is important, especially in cases where the safety margin of the ablated area was not sufficiently wide.

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

    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)

  5. Power, Consent and Resistance: An Autoethnography of Competitive Rowing

    Purdy, Laura; Potrac, Paul; Jones, Robyn

    2008-01-01

    This study builds upon existing socio-cultural work into sports coaching by probing the meanings and varieties of the shared coach-athlete experience. Specifically, the paper utilises an autoethnographic approach in an attempt to chart the complex and dynamic relationship that existed between me, the principal author, as a rowing coxswain and my…

  6. Rowing Crew Coordination Dynamics at Increasing Stroke Rates

    Cuijpers, Laura S.; Zaal, Frank T. J. M.; de Poel, Harjo J.

    2015-01-01

    In rowing, perfect synchronisation is important for optimal performance of a crew. Remarkably, a recent study on ergometers demonstrated that antiphase crew coordination might be mechanically more efficient by reducing the power lost to within-cycle velocity fluctuations of the boat. However, couple

  7. ROW (Right-of-Way) interfering construction activities management program

    Rosito, Roberta; Oliveira, Marisa; Lima, Shirley [TRANSPETRO - PETROBRAS Transporte S.A., Rio de Janeiro, RJ (Brazil)

    2009-07-01

    A significant portion of pipeline failures occurs due to external damage. This includes third party right of way (ROW) encroachment, which shall be identified and avoided. However, injuries caused by known and planned activities do happen. Construction of crossing or sharing ROW pipelines, crossing roads and bridges, neighboring buildings and excavations of any kind might put existing pipelines in risk. This paper presents how the TRANSPETRO ROW Interfering Construction Activities Management Program is implemented by a regional ROW maintenance department responsible for more than 3,000 km of pipelines, mostly in Rio de Janeiro and Minas Gerais states. This program is based on a TRANSPETRO procedure that was written after the publication of the Official Order number 125 of ANP (Oil, Gas and Biofuel Brazilian National Agency). Tasks from design review and approval to field construction supervision are performed by the staff responsible for the routine patrols and maintenance management. The ability of foreseeing risky activities is improved by expertise gained from day-to-day work on site. (author)

  8. Effect of row orientation on energy balance components

    Solar irradiance is the primary source of energy that is converted into sensible and latent heat fluxes in the soil-plant-atmosphere continuum. The orientation of agricultural crop rows relative to the sun’s zenith angle determines the amount of solar irradiance reaching the plant and soil surfaces...

  9. Intracranial carotid calcification on CT images as an indicator of atheromatous plaque. Analysis of high-resolution CTA images using a 64-multidetector scanner

    Intracranial arterial wall calcifications are frequently observed on routine head computed tomography (CT) images. The purpose of this study was to evaluate whether calcification of the intracranial carotid artery on CT images could predict atheromatous plaque and luminal stenosis. A total of 259 patients were examined using three-dimensional CT angiography using high-resolution 64 detector scanners. We examined patients from the petrous portion to the top of the internal carotid arteries. We evaluated the existence of calcification and atheromatous plaque based on our criteria retrospectively. The thickness of calcification was measured in each vessel, and the shape of calcification was classified into three types. There was low correlation between the thickness of the calcification and luminal stenosis, but the shape of the calcification corresponded well to the stenosis. The population of patients with >50% stenosis of the intracranial carotid artery differed statistically significantly for each calcification shape. There was a high negative predictive value (97.7%) in the correlation between the existence of calcification and atheromatous plaque on the multidetector CT images. Calcification of the intracranial carotid artery on CT images shows a high negative predictive value for the existence of atheromatous plaque in the same artery. The thickness of the calcification did not correlate well with luminal stenosis, but its shape seemed to predict luminal stenosis. (author)

  10. Optimization of detector sampling for mutlislice CT scanners

    Hsieh, Jiang

    1999-05-01

    In computed tomography (CT), the elapsed time of a complete organ coverage is an important parameter for many clinical applications. This requirement has let to the development of both sub-second and multi-slice CT scanners. Examples of the multi-slice scanners include twin beam CT and quad CT (QCT). Although they are different in terms of number of detector rows employed in the design, they share the common property that the spacing between adjacent detector rows is essentially identical to the detector cell size, and the spacing remains constant regardless of the scanning conditions. This restriction has led to a sub-optimal sampling along the patient axis. In this paper, we present an optimized detector sampling scheme. In the proposed scheme, the detector spacing is dynamically adjusted based on the helical pitch. This allows an improved sampling pattern along the patient axis. In conjunction with the proposed sampling scheme, an helical interpolation reconstruction algorithm is proposed. Detailed analysis and computer simulations are performed to validate our approach.

  11. Design, Construction and Evaluation of a Row Crop Thinning Machine

    M Gol Mohammadi

    2016-04-01

    Full Text Available Equipment availability is necessary in the development of Agriculture mechanization. Crop thinning is one of the most important stages in row crop production which is laborious and costly. The objective of this project is design and construction of a row crop thinning machine. Four main system units are plant sensors, ground sensors, control and thinning platforms. In this machine the unwanted plants on the rows are randomly removed by employing a pneumatically system. A blade on a vertical arm with pendulum motion removes the plant from the rows. The machine control system consists of an arm and a blade which is activated by a double acting cylinder and equipped with a relay and a timer. The pneumatic cylinder is controlled via a solenoid valve. Laboratory tests were conducted to validate the machine performance. Some other preliminary tests also were performed for optimization of parameters such as cinematic index and cutting length of blades. The laboratory tests (totally 9 tests were performed with a constant forward speed and three levels of plant density, using artificial plants. The data were analyzed using SPSS software. The results show that satisfactory performance of the machine is achieved when the plant density is moderate i.e. the thinning performance reduces with higher plant distance in the row. The other effective variable on machine performance is the adjustment of sensor sensitivity, which is used to distinguish between week and strong plants. In general the machine performance is sensitive to plant shape and morphology, plant distribution pattern in the field, growing stage of the plants, time of thinning and the effectiveness of previous weeding operations

  12. Children's (Pediatric) CT (Computed Tomography)

    ... Site Index A-Z Children's (Pediatric) CT (Computed Tomography) Pediatric computed tomography (CT) is a fast, painless exam that uses ... of Children's CT? What is Children's CT? Computed tomography, more commonly known as a CT or CAT ...

  13. The column and row immanants of matrices over a split quaternion algebra

    Kyrchei, Ivan

    2014-01-01

    The theory of the column-row determinants has been considered for matrices over a non-split quaternion algebra. In this paper the concepts of column-row determinants are extending to a split quaternion algebra. New definitions of the column and row immanants (permanents) for matrices over a non-split quaternion algebra are introduced, and their basic properties are investigated. The key theorem about the column and row immanants of a Hermitian matrix over a split quaternion algebra is proved....

  14. The investigation and design of a wireless augmented feedback rowing system.

    Collins, Daniel J.

    2011-01-01

    peer-reviewed The majority of research associated with the analysis of the rowing stroke is concentrated in laboratories due to the aquatic nature of rowing. The limitations of the tethered connection between the boat and land, has meant that on-water data collection of the rowing stroke has been severely limited. The stroke is a fundamental facet of rowing and can be considered a closed cyclic motor skill which is both physically and technically challenging. Therefore the analysis and opt...

  15. A Comparison of Kinematics and Performance Measures of Two Rowing Ergometers

    Rebecca R. Steer; McGregor, Alison H.; Bull, Anthony M. J.

    2006-01-01

    Rowing injuries have been attributed to poor technique, suggesting a need to understand the mechanics of rowing and the influence on technique of different training regimes and ergometers. The aims of this study were to investigate the repeatability of the kinematics of the lumbopelvic region during rowing and to compare these kinematics between rowing on two different ergometers. An electromagnetic motion measuring device in conjunction with a load cell was used to determine the ergometer ro...

  16. Comparative Analysis of Lossless Image Compression Based On Row By Row Classifier and Various Encoding Schemes on Color Images

    Ramandeep Kaur,

    2014-08-01

    Full Text Available Lossless image compression is needed in many fields like medical imaging, telemetry, geophysics, remote sensing and other applications, which require exact replica of original image and loss of information is not tolerable. In this paper, a near lossless image compression algorithm based on row by row classifier with encoding schemes like Lempel Ziv Welch (LZW, Huffman and Run Length Encoding (RLE on color images is proposed. The algorithm divides the image into three parts R, G and B, apply row by row classification on each part and result of this classification is records in the mask image. After classification the image data is decomposed into two sequences each for R, G and B and mask image is hidden in them. These sequences are encoded using different encoding schemes like LZW, Huffman and RLE. An exhaustive comparative analysis is performed to evaluate these techniques, which reveals that the proposed algorithm have smaller bits per pixel (bpp than simple LZW, Huffman and RLE encoding techniques.

  17. 77 FR 15597 - Special Local Regulation; USAT Triathlon/Race Rowing Competition; Black Warrior River; Tuscaloosa...

    2012-03-16

    ... SECURITY Coast Guard 33 CFR Part 100 RIN 1625-AA08 Special Local Regulation; USAT Triathlon/Race Rowing... the USAT Triathlon/Race Rowing Competition. Entry into, transiting in or anchoring in this area is... from safety hazards associated with the USAT Triathlon and Race Rowing Competition. Basis and...

  18. Mildew-resistant mutants induced in North American two- and six-rowed malting barley cultivars

    Molina-Cano, J.L.; Simiand, J.P.; Sopena, A.;

    2003-01-01

    Mildew-resistant mutants were induced with sodium azide in three North American malting barley cultivars, two in the six-rowed Ursula (URS1 and URS2), one in the six-rowed Gertrud (GER1), and one in the two-rowed Prudentia (PRU1). Two of the mutants, URS1 and PRU1, showed complete resistance and...

  19. 77 FR 25073 - Special Local Regulation; Hebda Cup Rowing Regatta, Trenton Channel; Detroit River, Wyandotte, MI

    2012-04-27

    ... SECURITY Coast Guard 33 CFR Part 100 RIN 1625-AA08 Special Local Regulation; Hebda Cup Rowing Regatta... on the navigable waters immediately prior to, during, and immediately after the Hebda Cup Rowing... Purpose On April 28, 2012, the Wyandotte Boat Club is holding a rowing race that will require...

  20. 33 CFR 100.724 - Annual Augusta Invitational Rowing Regatta; Savannah River, Augusta, GA.

    2010-07-01

    ... Rowing Regatta; Savannah River, Augusta, GA. 100.724 Section 100.724 Navigation and Navigable Waters... WATERS § 100.724 Annual Augusta Invitational Rowing Regatta; Savannah River, Augusta, GA. (a) Definitions... all non-participants. (2) After the termination of the Invitational Rowing Regatta each day,...

  1. Growth and yield of valencia, spanish, virginia and runner market type peanuts in various row spacings

    Currently, the majority of peanuts grown in New Mexico and West Texas are planted in single rows on beds 36 to 40 inches apart. In 2006-2008, several field studies were conducted with Valencia peanuts comparing single row, twin row, and diamond planting patterns in various populations. The basic c...

  2. YIELD RESPONSE TO PEANUT ROW ORIENTATION AND SEEDING RATE WHEN IRRIGATED USING SDI

    Peanut (Arachis hypogaea L.) are typically planted in a single or twin row orientation, however, research indicates that peanut planted at equidistance between rows and plants in alternating rows (diamond shape) and using the same planting rate can increase pod yield. A study was conducted to eval...

  3. HYBRID, ROW PATTERN, AND PLANT POPULATION COMPARISONS FOR CONSERVATION TILLAGE CORN PRODUCTION

    Corn (Zea mays L.) produced in narrow rows can increase yields and result in a quicker canopy closure. Costly equipment modifications make narrow rows impractical, but a twin row configuration may boost production with fewer equipment modifications. We compared yield, leaf area index, and weed bioma...

  4. Row Spacing and Plant Population Effects on Cotton Produced With or Without Irrigation

    Field studies were conducted from 2006 through 2008 to evaluate the effects of twin-row spacings, populations, and irrigation on cotton (Gossypium hirsutum L.) lint yields. Twin row systems, consisting of twin 18-, 25- and 38-cm rows on a 1-m bed at populations of 111,000 and 148,000 plants/acre, w...

  5. Brain perfusion CT for acute stroke using a 256-slice CT: improvement of diagnostic information by large volume coverage

    Dorn, F. [Technical University, Department of Radiology, Klinikum rechts der Isar, Munich (Germany); Institut fuer Radiologie, Klinikum rechts der Isar der Technischen Universitaet Muenchen, Muenchen (Germany); Muenzel, D.; Meier, R.; Rummeny, E.J.; Huber, A. [Technical University, Department of Radiology, Klinikum rechts der Isar, Munich (Germany); Poppert, H. [Technical University, Department of Neurology, Klinikum rechts der Isar, Munich (Germany)

    2011-09-15

    To compare a 256-slice CT with a simulated standard CT for brain CT perfusion (CTP). CTP was obtained in 51 patients using a 256-slice CT (128 detector rows, flying z-focus, 8-cm detector width, 80 kV, 120mAs, 20 measurements, 1 CT image/2.5 s). Signal-to-noise ratios (SNR) were compared in grey and white matter. Perfusion maps were evaluated for cerebral blood flow (CBF), cerebral blood volume (CBV) and mean transit time (MTT) in hypoperfused areas and corresponding contralateral regions. Two reconstructed 10-mm slices for simulation of a standard CT (SDCT) were compared with the complete data sets (large-volume CT, LVCT). Adequate image quality was achieved in 50/51 cases. SNR were significantly different in grey and white matter. A perfusion deficit was present in 27 data sets. Differences between the hypoperfusions and the control regions were significant for MTT and CBF, but not for CBV. Three lesions were missed by SDCT but detected by LVCT; 24 lesions were covered incompletely by SDCT, and 6 by LVCT. 21 lesions were detected completely by LVCT, but none by SDCT. CTP imaging of the brain using an increased detector width can detect additional ischaemic lesions and cover most ischaemic lesions completely. (orig.)

  6. Computed Tomography (CT) -- Head

    Full Text Available ... Physician Resources Professions Site Index A-Z Computed Tomography (CT) - Head Computed tomography (CT) of the head uses special x-ray ... What is CT Scanning of the Head? Computed tomography, more commonly known as a CT or CAT ...

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

    Chandrashekhar, Guruprasadh, E-mail: cguruprasadh@gmail.com [Departments of Radiodiagnosis and Imaging, Post Graduate Institute of Medical Education and Research, Sector-12, Chandigarh 160012 (India); Sodhi, Kushaljit Singh, E-mail: sodhiks@gmail.com [Departments of Radiodiagnosis and Imaging, Post Graduate Institute of Medical Education and Research, Sector-12, Chandigarh 160012 (India); Saxena, Akshay Kumar, E-mail: fatakshay@yahoo.com [Departments of Radiodiagnosis and Imaging, Post Graduate Institute of Medical Education and Research, Sector-12, Chandigarh 160012 (India); Rohit, Manoj Kumar, E-mail: rohitmanoj@gmail.com [Department of Pediatric Cardiology, Post Graduate Institute of Medical Education and Research, Sector-12, Chandigarh 160012 (India); Khandelwal, Niranjan, E-mail: khandelwaln@hotmail.com [Departments of Radiodiagnosis and Imaging, Post Graduate Institute of Medical Education and Research, Sector-12, Chandigarh 160012 (India)

    2012-12-15

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

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

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

  9. Three-dimensional CT laryngography: clinical application

    Kim, Yong; Kim, Jong Gi; Kim, Hak Jin; Lee, Suck Hong; Wang, Soo Guen [College of Medicine, Pusan National Univ., Pusan (Korea, Republic of)

    2003-10-01

    To evaluate the clinical usefulness of 3D volume-rendering (VR) CT laryngography during quiet breathing, Valsalva, and modified Valsalva maneuvers, in those with laryngeal and pyriform sinus lesions. Twenty-seven patients with various laryngeal and hypopharyngeal lesions were examined by means of four-channel multidetector-row helical CT (LightSpeed QX/i; GE Medical Systems, Milwaukee, Wis., U.S.A.) during quiet breathing, Valsalva, and modified Valsalva maneuvers. The protocol included 1.25-mm slice thickness, 3.75-mm rotation, 1.25 mm interval, and a pitch ratio of 3:1. Using an Advantage Windows 3.1 workstation (GE Medical Systems), 3D VR was generated in regions of interest, including all structures with a CT attenuation of between-1022 and -125 HU. Visual assessment of the findings of 3D CT laryngography, including the images obtained during the three different breathing maneuvers, were analyzed by three radiologists, who reached a consensus. These results were then compared with the findings of axial CT. The lesions discovered, in descending order of frequency, included laryngeal cancer (n=12), pyriform sinus cancer with an intact apex (n=6), pyriform sinus cancer with apex involvement (n=6), laryngeal papilloma (n=2), and hypopharyngeal obstruction with (n=1) and without (n=2) associated vocal cord palsy. In each case, the findings were confirmed by surgical biopsy, direct laryngoscopy, or CT. 3D CT laryngography using the VR technique can supplement the information provided by axial images, and in the assessment of subglottic invasion and pyriform sinus apical invasion, its findings are consistent. In many of our cases, its use during quiet breathing was able to determine whether or not glottic cancer involved subglottic invasion. In laryngeal cancer cases, furthormore, modified Valasalva can be used to clarify the condition of the pyriform sinus apex. Dynamic-phase 3D CT laryngography can be used to elucidate the condition of a patient with vocal cord

  10. Effects of Row-Type, Row-Spacing, Seeding Rate, Soil-Type, and Cultivar Differences on Soybean Seed Nutrition under US Mississippi Delta Conditions

    Bellaloui, Nacer; Bruns, Herbert A.; Abbas, Hamed K.; Mengistu, Alemu; Daniel K. Fisher; Reddy, Krishna N.

    2015-01-01

    The new Early Soybean Production System (ESPS), developed in the Midsouth USA, including the Mississippi delta, resulted in higher yield under irrigated and non-irrigated conditions. However, information on the effects of the agricultural practices such as row-type (RT: twin- vs. single-row), row-spacing, (RS), seeding rate (SR), soil-type (ST) on seed nutrition under the ESPS environment in the Mississippi delta is very limited. Our previous research in the Mississippi delta showed these agr...

  11. ROW1 maintains quiescent centre identity by confining WOX5 expression to specific cells

    Zhang, Yuzhou; Jiao, Yue; Liu, Zhaohui; Zhu, Yu-Xian

    2015-01-01

    The quiescent centre (QC) in the Arabidopsis root apical meristem is essential for stem cell organization. Here we show that the loss of REPRESSOR OF WUSCHEL1 (ROW1), a PHD domain-containing protein, leads to QC failure, defects in cell differentiation and ectopic expression of WUSCHEL-RELATED HOMEOBOX 5 (WOX5) in cells that normally express ROW1. The wox5-1/row1-3 double mutants show similar phenotypes to wox5-1 indicating that WOX5 is epistatic to ROW1. ROW1 specifically binds trimethylated...

  12. Don’t Rock the Boat: How Antiphase Crew Coordination Affects Rowing

    de Brouwer, Anouk J.; De Poel, Harjo J.; Mathijs J Hofmijster

    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 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 th...

  13. Detection of hypervascular hepatocellular carcinoma: Comparison of multi-detector CT with digital subtraction angiography and Lipiodol CT

    Xiao-Hua Zheng; Yong-Song Guan; Xiang-Ping Zhou; Juan Huang; Long Sun; Xiao Li; Yuan Liu

    2005-01-01

    AIM: The purpose of this study was to compare the diagnostic accuracy of biphasic multi-detector row helical computed tomography (MDCT), digital subtraction angiography (DSA)and Lipiodol computed tomography (CT) in detection of hypervascular hepatocellular carcinoma (HCC).METHODS: Twenty-eight patients with nodular HCC underwent biphasic MDCT examination: hepatic arterial phase (HAP) 25 s and portal venous phase (PVP) 70 s after injection of the contrast medium (1.5 mL/kg). They also underwent hepatic angiography and intra-arterial infusion of iodized oil. Lipiodol CT was performed 3-4 wk after infusion. MDCT images were compared with DSA and Lipiodol CT images for detection of hepatic nodules.RESULTS: The three imaging techniques had the same sensitivity in detecting nodules >20 mm in diameter. There was no significant difference in the sensitivity among HAP-MDCT, Lipiodol CT and DSA for nodules of 10-20 mm in diameter. For the nodules <10 mm in diameter, HAP-MDCT identified 47, Lipiodol CT detected 27 (X2= 11.3, P= 0.005<0.01, HAP-MDCT vs Lipiodol CT) and DSA detected 16(X2= 9.09, P= 0.005<0.01 vs Lipiodol CT and X2= 29.03,P = 0.005<0.01 vs HAP-MDCT). However, six nodules <10 mm in diameter were detected only by Lipiodol CT.CONCLUSION: MDCT and Lipiodol CT are two complementary modalities. At present, MDCT does not obviate the need for DSA and subsequent Lipiodol CT as a preoperative examination for HCC.

  14. Monitoring and evaluation of rowing performance using mobile mapping data

    Mpimis, A.; Gikas, V.

    2011-12-01

    Traditionally, the term mobile mapping refers to a means of collecting geospatial data using mapping sensors that are mounted on a mobile platform. Historically, this process was mainly driven by the need for highway infrastructure mapping and transportation corridor inventories. However, the recent advances in mapping sensor and telecommunication technologies create the opportunity that, completely new, emergent application areas of mobile mapping to evolve rapidly. This article examines the potential of mobile mapping technology (MMT) in sports science and in particular in competitive rowing. Notably, in this study the concept definition of mobile mapping somehow differs from the traditional one in a way that, the end result is not relevant to the geospatial information acquired as the moving platform travels in space. In contrast, the interest is placed on the moving platform (rowing boat) itself and on the various subsystems which are also in continuous motion.

  15. Random matrix ensembles with column/row constraints: II

    We numerically analyze the random matrix ensembles of real-symmetric matrices with column/row constraints for many system conditions e.g. disorder type, matrix-size and basis-connectivity. The results reveal a rich behavior hidden beneath the spectral statistics and also confirm our analytical predictions, presented in part I of this paper, about the analogy of their spectral fluctuations with those of a critical Brownian ensemble which appears between Poisson and Gaussian orthogonal ensemble. (paper)

  16. Three-Dimensional Turbomachine-Blade-Row Analysis Code

    Glassman, A. J.; Wood, J. R.

    1986-01-01

    Computer program (MERNEW3D) developed that prepares bulk of input data set required for Denton three-dimensional inviscid turbomachine-blade-row analysis code. Denton input generated from minimum of geometry and flow-variable information by using cubic spline curve fits for interpolation and extrapolation. Curve-fitting procedures taken from previously developed and widely used NASA computer program (MERIDL), which performs meridional streamsurface analysis.

  17. Policing Rock Bottom: Regulation, Rehabilitation, and Resistance on Skid Row

    Stuart, Forrest Daniel

    2012-01-01

    This dissertation engages a fundamental concern for sociologists, criminologists, and scholars of urban poverty: how authorities attempt to better control marginal social groups, and how those populations counteract and even resist these efforts. Drawing on five years of ethnographic fieldwork, interviews, and archival research, the dissertation analyzes daily life on the streets of Los Angeles' Skid Row district, a neighborhood widely-regarded as the "homeless capital of America," distinguis...

  18. Experimental studies on seismic behavior of PWR fuel assembly rows

    To qualify fuel assembly seismic resistance and to promote the development of new spacer grid designs, FRAMATOME (fuel division) and CEA have launched a large scale experimental program which will lead to improved models for safety analyses. The tests performed on reduced scale fuel assemblies were devoted to analyzing the assembly behavior during seismic motion. The aim of this paper is to present the main results of tests performed on rows of 5 and 13 assemblies

  19. Rowing Crew Coordination Dynamics at Increasing Stroke Rates

    Cuijpers, Laura S.; Zaal, Frank T.J.M.; De Poel, Harjo J.

    2015-01-01

    In rowing, perfect synchronisation is important for optimal performance of a crew. Remarkably, a recent study on ergometers demonstrated that antiphase crew coordination might be mechanically more efficient by reducing the power lost to within-cycle velocity fluctuations of the boat. However, coupled oscillator dynamics predict the stability of the coordination to decrease with increasing stroke rate, which in case of antiphase may eventually yield breakdowns to in-phase. Therefore, this stud...

  20. Acquiring 4D Thoracic CT Scans Using Ciné CT Acquisition

    Low, Daniel

    One method for acquiring 4D thoracic CT scans is to use ciné acquisition. Ciné acquisition is conducted by rotating the gantry and acquiring x-ray projections while keeping the couch stationary. After a complete rotation, a single set of CT slices, the number corresponding to the number of CT detector rows, is produced. The rotation period is typically sub second so each image set corresponds to a single point in time. The ciné image acquisition is repeated for at least one breathing cycle to acquire images throughout the breathing cycle. Once the images are acquired at a single couch position, the couch is moved to the abutting position and the acquisition is repeated. Post-processing of the images sets typically resorts the sets into breathing phases, stacking images from a specific phase to produce a thoracic CT scan at that phase. Benefits of the ciné acquisition protocol include, the ability to precisely identify the phase with respect to the acquired image, the ability to resort images after reconstruction, and the ability to acquire images over arbitrarily long times and for arbitrarily many images (within dose constraints).

  1. Vision-GPS Fusion for Guidance of an Autonomous Vehicle in Row Crops

    Bak, Thomas

    2001-01-01

    This paper presents a real-time localization system for an autonomous vehicle passing through 0.25 m wide crop rows at 6 km/h. Localization is achieved by fusion of mea-surements from a row guidance sensor and a GPS receiver. Conventional agricultural practice applies inputs such as herbicide at a...... constant rate ignoring the spatial variability in weed, soil, and crop. Sensing with a guided vehicle allow cost effective mapping of field variability and inputs may be adjusted accordingly. Essential to such a vehicle is real-time localization. GPS allow precise absolute sensing but it is not practical...... to guide the vehicle relative to the crop rows on an absolute coordinate. A row guidance sensor is therefore included to sense the position relative to the rows. The vehicle path in the field is re-planned online in order to allow for crop row irregularities sensed by the row sensor. The path...

  2. The use of IR barrier film for row covers in vegetable crops

    An experiment was conducted to study the effectiveness of IR barrier polyethylene film as a row cover. Earliness and yield of tomatoes in 4 replications was determined and ambient and soil temperatures monitored. Results indicate that the maximum average soil temperature was 3°C higher under the IR barrier cover than that under the clear plastic row cover. Average ambient air temperature was also approximately 5°C higher at night under the IR row cover than under the clear row cover. These increases resulted in a leaf area increase of 23% and a total weight of one month old plants of 33% under the IR barrier row covers. During the first two weeks of harvest, average yield per replication with IR barrier row cover was found to be 12% higher than the replications worth clear plastic row cover. (author)

  3. Optimization of Rowing Specific Training by Studying the Stages Evaluation

    Sanda T Urichianu

    2011-01-01

    Full Text Available Problem statement: We intended to analyze and systematize the most valuable ways through which is achieved the optimization in rowing training by the evaluation of control norms, trials and tests during some stages of the training plan. We consider that the sports performances can become better and better thanks to a continuous improvement of the working methodology during the main periods of training. Approach: The study was conducted over a period of 10 months (December 1, 2009-September 1, 2010 within the Sports Clubs, Juniors Department, men, of Falticeni and Iasi and it was made during the pre-competitive and competitive training period. The subjects of our research represent a group of 24 athletes from the two clubs: CS Falticeni and CS Iasi, out of which only 9 subjects have been able to obtained significant results. The study emphasizes the performances achieved during the control tests on ergometer rowing machines and on water (6000 and 2000 m events. Results: The study results confirmed that there is a significant relationship of the control tests results, erg and the competitive performance. The athletes’ performance is determined by the level of physical training specific to the rowing. Conclusion: To further enhance the performances, one should not neglect the study of any side which could help coaches and methods specialists in their work with the athletes.

  4. Intraoperative CT with integrated navigation system in spinal neurosurgery

    Zausinger, S.; Heigl, T.; Scheder, B.; Schnell, O.; Tonn, J.C.; Uhl, E. [Neurochirurgische Klinik, Ludwig-Maximilians-Univ. Muenchen (Germany); Morhard, D. [Inst. fuer Klinische Radiologie, Klinikum Grosshadern, Ludwig-Maximilians-Univ. Muenchen (Germany)

    2007-06-15

    For spinal surgery navigational system images are usually acquired before surgery with patients positioned supine. The aim of this study was to evaluate prospectively navigated procedures in spinal surgery with data acquisition by intraoperative computed tomography (iCT). CT data of 38 patients [thoracolumbar instability (n = 24), C1/2 instability (n = 6), cervicothoracic stabilization (n = 7), disk herniation (n = 1)] were acquired after positioning the patient in prone position. A sliding gantry 24 detector row CT was used for image acquisition. Data were imported to the frameless infrared-based neuronavigation station. A postprocedural CT was obtained to assess the extent of decompression and the accuracy of instrumentation. Intraoperative registration revealed computed accuracy <1 mm (0.9 {+-} 0.1 mm) in all cases. Control-iCT revealed incorrect screw position > 2 mm in 9/158 screws (5.6%), allowing immediate correction in five screws without any damage to vessels or nerves. There were three transient complications with clinical improvement in all patients. Intraoperative CT in combination with neuronavigation provides high accuracy of screw placement and thus safety for patients undergoing spinal stabilization. The procedure is rapid and easy to perform and - by replacing pre- and postoperative imaging-is not associated with additional exposure to radiation. (orig.)

  5. CT lymphography-guided sentinel lymph node biopsy

    Authors summarized their feasibility studies for clinical significance of CT lymphography-guided sentinel lymph node (SLN) mapping and biopsy in the breast, lung and esophageal cancers, with use of a recently developed water-soluble contrast medium, iopamidol. Subjects with breast cancers were 68 patients of the mean age 58 years old with the mean tumor size 21 mm. Local anesthesia was done by intradermal and subcutaneous injections of lidocaine, iopamidol was injected around the tumor, and 3D-CT was then conducted 20-30 sec later with the 4-row multidetector CT equipment, Siemens Somatom Volume Zoom. The CT was completed within 10-15 min with exposure doses of 14-18 mGy. Biopsy was then performed according to the 3D-CT map. Subjects with early stage lung and esophageal cancers were each 9 patients (mean ages 63 and 66 y) with the mean tumor size 21 mm and operable one, respectively. 3D-CT and biopsy were conducted essentially similarly to above. Shortly after injection of the contrast medium, all pathways of lymph ducts from the tumor to SLN were imaged, based on whose map biopsy was possible. This procedure can be practically useful for identification and biopsy of SLN in those cancers. (T.I.)

  6. Spinal CT scan, 1

    Methods of CT of the cervical and thoracic spines were explained, and normal CT pictures of them were described. Spinal CT was evaluated in comparison with other methods in various spinal diseases. Plain CT revealed stenosis due to spondylosis or ossification of posterior longitudinal ligament and hernia of intervertebral disc. CT took an important role in the diagnosis of spinal cord tumors with calcification and destruction of the bone. CT scan in combination with other methods was also useful for the diagnosis of spinal injuries, congenital anomalies and infections. (Ueda, J.)

  7. Row, Row, Row Your Boat...

    PHILIP JONES

    2010-01-01

    @@ My afternoon plans to go dragon boat racing on Houhai Lake in downtown Beijing could have started better. Cycling across town, a pedal snapped off my bicycle as I was aggressively building up speed across a Second Ring Road junction.

  8. Evaluation of pituitary adenomas by multidirectional multislice dynamic CT

    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

  9. Optimization of Inter-Row Spacing and Nitrogen Rate for the Application of Vision Guided Inter-Row weeding in Organic Spring Cereals

    Melander, Bo; Green, O.; Znova, L.

    2016-01-01

    increasing row spacing was important for preserving crop yields. The best results in terms of weeding effectiveness and crop yield were achieved with 15 and 20 cm row spacing and high N rate; most evident in spring barley. It was seen that the traditional ‘Ducksfoot’ blade is not an optimal solution for...

  10. Mode of inheritance and combining abilities for kernel row number, kernel number per row and grain yield in maize (Zea mays L.

    Boćanski Jan

    2010-01-01

    Full Text Available Utilization of heterosis requires the study of combining abilities of potential parents. In view of this, the objective of this paper was to study combining abilities and determine the mode of inheritance and gene effects for the main agronomic character, grain yield, and its components, kernel row number and kernel number per row. Six inbred lines were used in the study, three of which originated in the U.S., while the other three were developed at the Institute of Field and Vegetable Crops in Novi Sad. Kernel row number was inherited by superdominance, partial dominance, complete dominance and intermediacy. The mode of inheritance of kernel number per row and grain yield was superdominance. Additive gene action had the greatest influence on the expression of kernel row number, while the other two traits were influenced the most by nonadditive gene.

  11. Computed Tomography (CT) -- Sinuses

    Full Text Available ... to a CD or DVD. CT images of internal organs, bones, soft tissue and blood vessels typically ... clicking and whirring sounds as the CT scanner's internal parts, not usually visible to you, revolve around ...

  12. Computed Tomography (CT) -- Head

    Full Text Available ... to a CD or DVD. CT images of internal organs, bones, soft tissue and blood vessels typically ... clicking and whirring sounds as the CT scanner's internal parts, not usually visible to you, revolve around ...

  13. Computed Tomography (CT) -- Sinuses

    Full Text Available ... or DVD. CT images of internal organs, bones, soft tissue and blood vessels typically provide greater detail than traditional x-rays, particularly of soft tissues and blood vessels. A CT scan of the ...

  14. Computed Tomography (CT) -- Head

    Full Text Available ... or DVD. CT images of internal organs, bones, soft tissue and blood vessels typically provide greater detail than traditional x-rays, particularly of soft tissues and blood vessels. CT scanning provides more detailed ...

  15. Computed Tomography (CT) -- Head

    Full Text Available ... resulting in more detail and additional view capabilities. Modern CT scanners are so fast that they can ... to ensure that you are properly positioned. With modern CT scanners, you will hear only slight buzzing, ...

  16. Computed Tomography (CT) -- Sinuses

    Full Text Available ... resulting in more detail and additional view capabilities. Modern CT scanners are so fast that they can ... to ensure that you are properly positioned. With modern CT scanners, you will hear only slight buzzing, ...

  17. Computed Tomography (CT) -- Head

    Full Text Available ... view of the body's interior. Refinements in detector technology allow nearly all CT scanners to obtain multiple ... scanning is painless, noninvasive and accurate. A major advantage of CT is its ability to image bone, ...

  18. Computed Tomography (CT) -- Sinuses

    Full Text Available ... view of the body's interior. Refinements in detector technology allow nearly all CT scanners to obtain multiple ... scanning is painless, noninvasive and accurate. A major advantage of CT is its ability to image bone, ...

  19. Computed Tomography (CT) -- Sinuses

    Full Text Available ... actual CT scanning is performed. Depending on the type of CT scan, the machine may make several passes. You may be asked to hold your breath during the scanning. Any motion, whether breathing ...

  20. Computed Tomography (CT) -- Head

    Full Text Available ... actual CT scanning is performed. Depending on the type of CT scan, the machine may make several passes. You may be asked to hold your breath during the scanning. Any motion, whether breathing ...

  1. Computed Tomography (CT) -- Sinuses

    Full Text Available ... be viewed on a computer monitor, printed on film or transferred to a CD or DVD. CT ... distinguished from one another on an x-ray film or CT electronic image. In a conventional x- ...

  2. Computed Tomography (CT) -- Head

    Full Text Available ... be viewed on a computer monitor, printed on film or transferred to a CD or DVD. CT ... distinguished from one another on an x-ray film or CT electronic image. In a conventional x- ...

  3. Computed Tomography (CT) -- Sinuses

    Full Text Available ... air-filled spaces within the bones of the face surrounding the nasal cavity. CT scanning is painless, ... and blood vessels. A CT scan of the face produces images that also show a patient's paranasal ...

  4. Computed Tomography (CT) -- Head

    Full Text Available ... dose technique. top of page What are the limitations of CT Scanning of the Head? A person ... CT scanner or may be over the weight limit—usually 450 pounds—for the moving table. Compared ...

  5. Computed Tomography (CT) -- Sinuses

    Full Text Available ... body. The cross-sectional images generated during a CT scan can be reformatted in multiple planes, and can ... particularly of soft tissues and blood vessels. A CT scan of the face produces images that also show ...

  6. Computed Tomography (CT) -- Head

    Full Text Available ... body. The cross-sectional images generated during a CT scan can be reformatted in multiple planes, and can ... scanning is performed. Depending on the type of CT scan, the machine may make several passes. You may ...

  7. Computed Tomography (CT) -- Head

    Full Text Available ... DVD. CT images of internal organs, bones, soft tissue and blood vessels typically provide greater detail than traditional x-rays, particularly of soft tissues and blood vessels. CT scanning provides more detailed ...

  8. Computed Tomography (CT) -- Sinuses

    Full Text Available ... DVD. CT images of internal organs, bones, soft tissue and blood vessels typically provide greater detail than traditional x-rays, particularly of soft tissues and blood vessels. A CT scan of the ...

  9. Computed Tomography (CT) -- Head

    Full Text Available ... CT Angiography page . top of page How should I prepare? You should wear comfortable, loose-fitting clothing ... within 10 minutes. top of page What will I experience during and after the procedure? CT exams ...

  10. Computed Tomography (CT) -- Sinuses

    Full Text Available ... sinus cavities – hollow, air-filled spaces within the bones of the face surrounding the nasal cavity. CT ... CD or DVD. CT images of internal organs, bones, soft tissue and blood vessels typically provide greater ...

  11. Computed Tomography (CT) -- Sinuses

    Full Text Available ... top of page What are the benefits vs. risks? Benefits A CT scan is one of the ... CT scans should have no immediate side effects. Risks There is always a slight chance of cancer ...

  12. Computed Tomography (CT) -- Head

    Full Text Available ... top of page What are the benefits vs. risks? Benefits CT scanning is painless, noninvasive and accurate. ... CT scans should have no immediate side effects. Risks There is always a slight chance of cancer ...

  13. Computed Tomography (CT) -- Sinuses

    Full Text Available ... the scanning. Any motion, whether breathing or body movements, can lead to artifacts on the images. This ... clinical problems. CT is less sensitive to patient movement than MRI. CT can be performed if you ...

  14. Computed Tomography (CT) -- Head

    Full Text Available ... the scanning. Any motion, whether breathing or body movements, can lead to artifacts on the images. This ... clinical problems. CT is less sensitive to patient movement than MRI. CT can be performed if you ...

  15. Computed Tomography (CT) -- Sinuses

    Full Text Available ... vessels. CT examinations are fast and simple; in emergency cases, they can reveal internal injuries and bleeding ... See the Safety page for more information about pregnancy and x-rays. CT scanning is, in general, ...

  16. Computed Tomography (CT) -- Head

    Full Text Available ... microphone. top of page How does the procedure work? In many ways CT scanning works very much ... many types of tissue as well as the lungs, bones, and blood vessels. CT examinations are fast ...

  17. Computed Tomography (CT) -- Sinuses

    Full Text Available ... microphone. top of page How does the procedure work? In many ways CT scanning works very much ... many types of tissue as well as the lungs, bones, and blood vessels. CT examinations are fast ...

  18. Computed Tomography (CT) -- Head

    Full Text Available ... Contrast Media and its references. The risk of serious allergic reaction to contrast materials that contain iodine ... of soft tissue (particularly the brain, including the disease processes) are less visible on CT scans . CT ...

  19. Gallstone ileus: CT findings

    Delabrousse, E.; Bartholomot, B.; Sohm, O.; Kastler, B. [Dept. of Radiology A, CHU Jean Minjoz, University of Besancon (France); Wallerand, H. [Dept. of Surgery, CHU Jean Minjoz, University of Besancon (France)

    2000-06-01

    Gallstone ileus is a rare complication of recurrent gallstone cholecystitis. The classic radiographic triad of small bowel obstruction, pneumobilia and ectopic gallstone on abdominal plain radiograph is described with CT imaging. Because of the better resolution of CT compared with abdominal radiography and its recent accession to emergency use, radiologists should be aware of CT findings of gallstone ileus. We report a case in which gallstone ileus was initially diagnosed by CT. (orig.)

  20. CT Colonography (Virtual Colonoscopy)

    ... how do I get them? What are the benefits vs. risks? What are the limitations of CT Colonography? What is CT Colonography? Computed tomography, more commonly known as a CT or CAT scan, is a diagnostic medical test that, like traditional ...

  1. Computed Tomography (CT) -- Head

    Full Text Available ... CT examinations are fast and simple; in emergency cases, they can reveal internal injuries and bleeding quickly enough to help save lives. CT has been shown to be a cost-effective imaging tool for a wide range of clinical problems. CT is less sensitive to patient movement ...

  2. Computed Tomography (CT) -- Sinuses

    Full Text Available ... CT examinations are fast and simple; in emergency cases, they can reveal internal injuries and bleeding quickly enough to help save lives. CT has been shown to be a cost-effective imaging tool for a wide range of clinical problems. CT is less sensitive to patient movement ...

  3. Multidetector-row spiral computed tomography in chest emergencies; MSCT bei thorakalen Notfaellen

    Wildberger, J.E.; Leiner, T. [Maastricht University Medical Center (MUMC) (Netherlands). Department of Radiology; Mahnken, A.H. [Universitaetsklinikum Aachen (Germany). Klinik fuer Radiologische Diagnostik; RWTH Aachen (Germany). Angewandte Medizintechnik, Helmholtz-Institut fuer Biomedizinische Technik

    2009-06-15

    With ongoing advances in multidetector-row computed tomography (MDCT) using ECG gating, differentiated examination protocols have become technically feasible. For acute chest pain assessment a strict triage of patients is indispensable, as the radiation dose is approximately 3 times higher for a dedicated protocol compared to a standard chest MDCT. Clinical requests considering pathologies of the pulmonary arteries, the aortic arch and the descending aorta can safely be answered with a standard CT data set. However, for the coronary arteries as well as for the ascending aorta, ECG synchronization of the data set is required. Initial reports regarding MDCT assessment for acute chest pain report a high negative predictive value. With the latest MDCT platforms available, medical preparation is no longer necessary with the exception of sublingual application of nitroglycerine. Dedicated contrast injection protocols, however, are necessary for simultaneous opacification of the pulmonary arteries as well as of the aorta and the coronary arteries. Further prospective studies will have to provide more evidence-based data for acute chest pain assessment with MDCT and will also have to outline the cost-effectiveness of this imaging technique. (orig.) [German] Die Weiterentwicklung der Mehrschichtspiralcomputertomographie (MSCT) mit EKG-Synchronisation ermoeglicht differenzierte Untersuchungsprotokolle zur Abklaerung unklarer thorakaler Schmerzereignisse, erfordert jedoch aufgrund der gegenueber einer herkoemmlichen CT des Thorax ca. 3-fach hoeheren Strahlenexposition eine enge Indikationsstellung. Fragestellungen, die isoliert die Lungengefaesse, den Aortenbogen bzw. die deszendierende Aorta betreffen, koennen meist bereits mit einem Standard-CT-Datensatz beantwortet werden, fuer Pathologien der Aorta ascendens und zum Ausschluss einer koronaren Herzerkrankung (KHK) ist eine Submillimeterkollimation mit EKG-Synchronisation hingegen unerlaesslich. Erste Studienergebnisse

  4. Plant, soil, and shadow reflectance components of row crops

    Richardson, A. J.; Wiegand, C. L.; Gausman, H. W.; Cuellar, J. A.; Gerbermann, A. H.

    1975-01-01

    Data from the first Earth Resource Technology Satellite (LANDSAT-1) multispectral scanner (MSS) were used to develop three plant canopy models (Kubelka-Munk (K-M), regression, and combined K-M and regression models) for extracting plant, soil, and shadow reflectance components of cropped fields. The combined model gave the best correlation between MSS data and ground truth, by accounting for essentially all of the reflectance of plants, soil, and shadow between crop rows. The principles presented can be used to better forecast crop yield and to estimate acreage.

  5. Random matrix ensembles with column/row constraints: I

    We analyze statistical properties of a complex system subjected to conditions which manifests through specific constraints on the column/row sum of the matrix elements of its Hermitian operators. The presence of additional constraints besides real-symmetric nature leads to new correlations among their eigenfunctions, hinders a complete delocalization of dynamics and affects the eigenvalues too. The statistical analysis of the latter indicates the presence of a new universality class analogous to that of a special type of Brownian ensemble appearing between Poisson and Gaussian orthogonal ensemble. (paper)

  6. Beziehung zwischen primären Multi-Slice-CT-Befunden und posttraumatischer Lebensqualität bei polytraumatisierten Patienten

    Knopke, Steffen

    2010-01-01

    Purpose: To determine the added diagnostic benefit of using MS-CT and to determine the quality of life in multiple trauma patients differentiated by severity of injury and affected body region. Materials and Methods: A retrospective analysis was performed of the 16-row whole-body spiral CT findings in 275 multiple trauma patients (73.1% men, 26.9% women; age 39.6 ± 18.9 years) with regard to additional findings and new findings obtained with CT compared to the findings obtained by conventi...

  7. Multislice CT: technical principles and future trends

    Multislice scanning has substantially improved the performance of CT scanners, and thus the relation between scan duration, available scan length, and spatial resolution along the patient axis (z-axis). Near-isotropic imaging of whole organ systems is already possible with 4-slice scanners, but only with 8- to 16-slice scanners can the scan duration be shortened as well. Reconstructing overlapping thin-section data (''secondary raw data set'') provides the basis for image reconstruction in any desired plane. By using thick multiplanar reformation (MPR) techniques, image quality can be improved while keeping patient dose low. Using unfavorable scanning parameters, exposure dose can be substantially increased compared with single-slice scanning, but thick MPR and individual-dose modulation techniques can provide the basis for dose reduction. Low-kVp scanning, in particular, is useful in children and slim adults and is an excellent technique to improve image contrast in CT angiographic studies. Short spiral scans should be avoided with multislice CT since overranging (extra rotations at the beginning and end of the scan, used for data interpolation) can substantially increase patient dose. Future trends include the introduction of thinner detector rows, wider detector arrays, faster tube rotation, and area detectors than can also be used for fluoroscopy. Noise-reduction techniques and individual dose modulation will gain importance with higher isotropic resolution. Functional and perfusion imaging, as well as advanced image processing and computer-aided diagnosis programs, will add to the possibilities of the next generation of multislice CT scanners. (orig.)

  8. Pediatric metrizamide CT cisternography and CT ventriculography

    We have studied the diagnostic value of computed tomography with metrizamide CSF enhancement in 37 infants. According to the method of injection, we called CT cisternography, CT ventriculography and CT cystography. These methods were useful for the morphologic and dynamic evaluation of the CSF pathways. We used them especially for the evaluation of hydrocephalus, skull base tumor, infantile subdural hematoma and its allied diseases, or congenital cystic lesion such as Dandy-Walker syndrome. The side effects in children are much less than those in adults. (author)

  9. Multislice CT angiography

    The introduction of multislice CT into clinical radiology constitutes a quantum leap that significantly widens the scope of vascular CT imaging. The advances over conventional spiral CT have been quantitative, mainly in terms of increased image acquisition speed which provides unprecedented volume coverage and spatial resolution. Moreover, significant technical innovations, such as cardiac scanning capabilities, have brought about a qualitative shift towards applications that were thought to be beyond the scope of CT imaging. This way multislice CT offers a wealth of new opportunities for quickly and accurately diagnosing suspected vascular disease in all organ systems; however, as we move towards faster and faster image acquisition techniques, we are also facing new challenges that require development of novel strategies in order to take full advantage of the increased capabilities of multislice CT in its current form and future generations of CT scanners. (orig.)

  10. Distal Row Carpectomy—A Possible Salvage Procedure of Severe Carpal Trauma

    Brodbeck, Rebekka; Horch, Raymund E.; Arkudas, Andreas

    2015-01-01

    Summary: Complex fracture dislocations of the wrist often result in posttraumatic arthrosis. In trying to avoid total arthrodesis, alternative treatment strategies have been investigated. For this purpose, we present the case of a 56-year-old male patient who sustained a direct trauma during a circular saw accident, resulting in the destruction of the distal carpal row among other things. However, the proximal carpal row was found completely intact. We indicated an emergency distal row carpec...

  11. Distal Row Carpectomy—A Possible Salvage Procedure of Severe Carpal Trauma

    Brodbeck, Rebekka; Horch, Raymund E.; Arkudas, Andreas

    2015-01-01

    Complex fracture dislocations of the wrist often result in posttraumatic arthrosis. In trying to avoid total arthrodesis, alternative treatment strategies have been investigated. For this purpose, we present the case of a 56-year-old male patient who sustained a direct trauma during a circular saw accident, resulting in the destruction of the distal carpal row among other things. However, the proximal carpal row was found completely intact. We indicated an emergency distal row carpectomy. Eig...

  12. Fixed versus free-floating stretcher mechanism in rowing ergometers : mechanical aspects

    COLLOUD, F; BAHUAUD, P; DORIOT, N; CHAMPELY, S; Cheze, L.

    2006-01-01

    The mechanical responses (i.e. external contact forces and external power) of 25 elite rowers to a race-pace rowing protocol were investigated on the traditional fixed stretcher mechanism and the more recently introduced free-floating stretcher mechanism rowing ergometers. Using a Rowperfect rowing ergometer for both conditions, external contact forces at the handle, stretcher and sliding seat, as well as the displacements of the handle and stretcher, were recorded. The external power was cal...

  13. Prediction of Rowing Ergometer Performance from Functional Anaerobic Power, Strength and Anthropometric Components

    Akça Firat

    2014-01-01

    The aim of this research was to develop different regression models to predict 2000 m rowing ergometer performance with the use of anthropometric, anaerobic and strength variables and to determine how precisely the prediction models constituted by different variables predict performance, when conducted together in the same equation or individually. 38 male collegiate rowers (20.17 ± 1.22 years) participated in this study. Anthropometric, strength, 2000 m maximal rowing ergometer and rowing an...

  14. (Originals) Anthropometric and Physiological Factors Predicting 2000 m Rowing Ergometer Performance Time

    Yoshiga, Chie; Kawakami, Yasuo; Fukunaga, Tetsuo; Okamura, Kohji; Higuchi, Mitsuru

    2000-01-01

    YOSHIGA, C., KAWAKAMI, Y., FUKUNAGA, T., OKAMURA, K. and HIGUCHI, M., Anthropometric and Physiological Factors Predicting 2000 m Rowing Ergometer Performance Time. Adv. Exerc. Sports Physiol., Vol.6, No.2 pp51-57, 2000. In attempt to prediet 2000 m rowing ergometer performance time, we studied anthropometric and physilogical l limiting factors among 78 collegiate male rowers. Among variables that we measured, 2000 m rowing performance time was significantly and inversely related to lean body...

  15. Changes in Rowing Technique Over a Routine One Hour Low Intensity High Volume Training Session

    Mackenzie, Hugh A.M.; Bull, Anthony M. J.; McGregor, Alison H.

    2008-01-01

    High volume low intensity training sessions such as one hour rowing ergometer sessions are frequently used to improve the fitness of elite rowers. Early work has suggested that technique may decline over this time period. This study sought to test the hypothesis that “elite rowers can maintain technique over a one hour rowing ergometer session”. An electromagnetic device, in conjunction with a load cell, was used to assess rowing technique in terms of force generation and spinal kinematics in...

  16. Muscle Synergies of Untrained Subjects during 6 min Maximal Rowing on Slides and Fixed Ergometer

    Shaharudin, Shazlin; Zanotto, Damiano; Agrawal, Sunil

    2014-01-01

    The slides ergometer (SE) was an improvisation from fixed ergometer (FE) to bridge the gap of mechanics between ergometer rowing and on-water rowing. The specific mechanical constraints of these two types of ergometers may affect the pattern of muscle recruitment, coordination and adaptation. The main purpose of this study was to evaluate the muscle synergy during 6 minutes maximal rowing on slides (SE) and fixed ergometers (FE). The laterality of muscle synergy was also examined. Surface ele...

  17. A COMPARISON OF KINEMATICS AND PERFORMANCE MEASURES OF TWO ROWING ERGOMETERS

    Rebecca R. Steer

    2006-03-01

    Full Text Available Rowing injuries have been attributed to poor technique, suggesting a need to understand the mechanics of rowing and the influence on technique of different training regimes and ergometers. The aims of this study were to investigate the repeatability of the kinematics of the lumbopelvic region during rowing and to compare these kinematics between rowing on two different ergometers. An electromagnetic motion measuring device in conjunction with a load cell was used to determine the ergometer rowing kinematics of 12 rowers. Subjects were tested on three occasions at two different stroke rates, with an interval of one week between testing. Two datasets were obtained for the Concept II, to establish the repeatability of the kinematics, and one for the WaterRower. Bland and Altman's mean difference technique was used to test for consistency of technique, and the difference between ergometers was assessed using Students' paired T-tests. The kinematic measures of the lumbo pelvic region during rowing demonstrated high repeatability. The two ergometers showed a similarity in force profiles but some significant differences in rowing kinematics. There was greater rotation of the thigh segment in the sagittal plane throughout the stroke on the WaterRower (p < 0.01. There were also trends indicating that rotation of the pelvis in the sagittal plane was different between the two ergometers, for example on the Concept the mean angle of the pelvis at the catch was 5.4° and on the WaterRower it was 2.4° (p < 0.05. Measurement of lumbopelvic kinematics during rowing on a Concept II ergometer is repeatable. However, rowing kinematics varies between ergometers. Because a full analysis comparing rowing kinematics on water with rowing ergometers has not been made in this study, no conclusions regarding which ergometer simulates rowing on water can be made. The implications of the effect of these differences in technique requires further investigation

  18. Cross-sectional analysis of rowing power and technique of German junior women in the eight

    Mattes, Klaus; Schaffert, Nina; Manzer, Stefanie; Böhmert, Wolfgang

    2015-01-01

    Since ten years, the German Rowing Federation (DRV) annually conducted 2000-m-race-tests with the best-performing athletes at the beginning of the immediate-pre-competition-preparation (IPCP) for the World-Rowing-Junior-Championships (WRJC). According to previous findings, differences between year-groups, correlations between anthropometric-data, rowing-power and technique development were tested to identify trends and to define a performance-strategy. Twenty test-runs of the junior-women’s-E...

  19. Muscle Synergies of Untrained Subjects during 6 min Maximal Rowing on Slides and Fixed Ergometer.

    Shaharudin, Shazlin; Zanotto, Damiano; Agrawal, Sunil

    2014-12-01

    The slides ergometer (SE) was an improvisation from fixed ergometer (FE) to bridge the gap of mechanics between ergometer rowing and on-water rowing. The specific mechanical constraints of these two types of ergometers may affect the pattern of muscle recruitment, coordination and adaptation. The main purpose of this study was to evaluate the muscle synergy during 6 minutes maximal rowing on slides (SE) and fixed ergometers (FE). The laterality of muscle synergy was also examined. Surface electromyography activity, power output, heart rate, stroke length and stroke rate were analyzed from nine physically active subjects to assess the rowing performance. Physically active subjects, who were not specifically trained in rowing, were chosen to exclude the training effect on muscle synergy. Principal component analysis (PCA) with varimax rotation was applied to extract muscle synergy. Three muscle synergies were sufficient to explain the majority of variance in SE (94.4 ± 2.2 %) and FE (92.8 ± 1.7 %). Subjects covered more rowing distance, exerted greater power output and attained higher maximal heart rate during rowing on SE than on FE. The results proved the flexibility of muscle synergy to adapt to the mechanical constraints. Rowing on SE emphasized on bi-articular muscles contrary to rowing on FE which relied on cumulative effect of trunk and upper limb muscles during propulsive phase. Key pointsThree muscle synergies were extracted during maximal rowing on both fixed and slides ergometerUntrained subjects emphasized leg muscles while rowing on SEUntrained subjects focused on back muscles during FE rowing. PMID:25435771

  20. Comparison of dynamic CT and dynamic MR imaging for detection of hepatocellular carcinoma

    Dynamic study using contrast agents have been used to detection of the hepatocellular carcinoma (HCC). Some reports indicated that the detectability of small nodules in liver with MRI-dynamic study is significantly superior to that with CT-dynamic study. However, these reasons are unknown. Therefore, the contrast, temporal and spatial resolutions were compared for dynamic studies of MRI and CT. Two contrast phantoms were made for MRI and CT. Both phantoms were constructed using same dilute rates of contrast material: Gd-DTPA and Iodine. The signal intensity of some different dilute rate's contrast media was measured for comparison of signal to noise ratio (SNR), contrast to noise ratio (CNR) and contrast. Time-intensity curves simulated with pharmacokinetic compartment model were evaluated for temporal resolution. In addition, the spatial resolution of CT and MR images were compared using the modulation transfer function (MTF). In the results, contrasts of phantoms with MRI and CT-dynamic study were almost same. However, MRI-dynamic study were superior to CT-dynamic study for SNR and contrast. For the distributed rates of contrast media at aortic phase, MRI-dynamic study was higher than helical CT-dynamic study but same as Multi detector-row CT (MDCT). For spatial resolution, CT images were superior to MR images. Therefore, it was recommended that MRI-dynamic study should be examined for fatty patients and MDCT-dynamic study should be examined for thin patients. (author)