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Sample records for 64-detector row ct

  1. Whole tumour perfusion of peripheral lung carcinoma: evaluation with first-pass CT perfusion imaging at 64-detector row CT

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    Li, Y. [Department of Radiology, West China Hospital, Sichuan University, Chengdu, Sichuan (China); Yang, Z.-G. [Department of Radiology, West China Hospital, Sichuan University, Chengdu, Sichuan (China); National Key Laboratory of Biotherapy Center, West China Hospital, Sichuan University, Chengdu, Sichuan (China)], E-mail: yangzg1117@yahoo.com.cn; Chen, T.-w.; Deng, Y.-p.; Yu, J.-q.; Li, Z.-l. [Department of Radiology, West China Hospital, Sichuan University, Chengdu, Sichuan (China)

    2008-06-15

    Aim: To prospectively assess the feasibility of a whole-tumour perfusion technique using 64-detector row computed tomography (CT) and to analyse the variation of CT perfusion parameters in different histological types, sizes, and metastases in patients with peripheral lung carcinoma. Methods and materials: Ninety-seven pathologically proved peripheral lung carcinomas (less than 5 cm in largest diameter) underwent dynamic contrast-enhanced CT using a 64-detector row CT machine. Small amounts of iodinated contrast medium with a sharp bolus profile (50 ml, 6-7 ml/s), and 12 repeated fast acquisitions encompassing the entire tumour lesion were adopted to quantify perfusion of the whole-tumour during first-pass of contrast medium. Four kinetic parameters, including perfusion, peak enhancement intensity (PEI), time to peak (TTP), and blood volume (BV), were measured and statistically compared among different histological types, sizes, and metastases. Results: Mean values for perfusion, PEI, TTP, and BV of the 97 lung carcinomas were 57.5 {+-} 45.4 ml/min/ml (range 5.9-243 ml/min/ml), 53.4 {+-} 40.6 HU (range 10.3-234.4 HU), 34 {+-} 11 s (range 11-60 s), and 30.1 {+-} 21.7 ml/100 g (range 3.9-113.4 ml/100 g), respectively. No statistical differences were found between the histological types regarding the perfusion parameters (p > 0.05). Perfusion, PEI, and BV of stage T2 tumours were significantly lower than those of stage T1 tumours (all p < 0.05), whereas no statistically significant differences was found between other stages of tumours (all p > 0.05). Perfusion of the tumours with distant metastasis was significantly higher than that of the tumours without distant metastasis (p < 0.05), but there was no statistically significant difference between nodal metastasis positive and negative groups (p > 0.05). Conclusion: The present study of first-pass perfusion imaging using 64-detector row CT could provide a feasible method for assessment of whole-tumour perfusion. CT

  2. [Peripheral lung adenocarcinoma versus squamous cell carcinoma: evaluation with first-pass perfusion imaging using 64-detector row CT].

    Science.gov (United States)

    Li, Yuan; Yang, Zhigang; Chen, Tianwu; Yu, Jianqun; Deng, Yuping; Li, Zhenlin

    2009-04-01

    The aim of this study was to elucidate the characteristics of time attenuation curve and CT perfusion parameters for pulmonary adenocarcinomas and squamous cell carcinomas. 58 cases of pulmonary adenocarcinomas and 27 cases of squamous cell carcinomas underwent first pass CT perfusion imaging with 64-row MDCT. Data were analyzed using commercial software to generate time attenuation curve (TAC) and CT perfusion parameters, including perfusion, peak enhanced (PE), time to peak (TTP), and blood volume (BV). For TAC, there were 36.2% of type I and 63.8% of type II in adenocarcinomas, while there were 22.2% of type I and 77.8% of type II in squamous cell carcinomas. There was not significant difference (P>0.05). Perfusion, PE, TTP and BV of adenocarcinomas were 63.2 +/- 45.4 ml x min(-1) x ml(-1), 60.2 +/- 46.6 Hu, 34.8 +/- 10.2 s and 34.3 +/- 23.6 ml x 100 g(-1), respectively, while 54.3 +/- 50.2 ml x min(-1) x ml(-1), 48.5 +/- 34.9 Hu, 36.1 +/- 11.2 s and 27.6 +/- 21.7 ml x 100 g(-1), for squamous cell carcinoma, respectively. No significant differences were found between groups (P>0.05). No significant differences in TAC and CT perfusion parameters were found between adenocarcinomas and squamous cell carcinomas.

  3. 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?

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    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.)

  4. 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?

    International Nuclear Information System (INIS)

    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.)

  5. 不同剂量对比剂在64排螺旋CT脑动脉成像中的比较研究%Comparative study on various dosage contrast agents in 64-detector row CT cerebral angiography

    Institute of Scientific and Technical Information of China (English)

    石林平; 黎雪琴; 李长英; 郝光远; 罗红亮; 郑石林

    2014-01-01

    Objective To compare the imaging quality of various dosage contrast agents,and explore the effect of various dosage contrast agents on vascular enhancement in 64-detector row CT cerebral angiography(CTA).Methods A total of 183 patients with suspected or confirmed intracranial vascular disease were enrolled,included 97 males and 86 females,aged 41-75 years old with mean age of 56.All of them were performed CTA with Iopromide(370 mgI/mL) as the contrast agents.They were divided into 3 groups in injection quantity,with group A(n =64),B(n =60) and C(n =59) received 50 mL,70 mL and 90 mL contrast agents,respectively.After injection of the contrast agents,30 mL 0.9 % sodium chloride solution was used for flushing at the same flow rate of contrast agents injection(4.5 mL/s).The CT values were measured on transverse images at right and left internal carotid arteries,A2 segment,M2 segment,and P2 segment,basilar artery,great cerebral vein,superior sagittal sinus,and dominant sigmoid sinus.The image quality parameters (intra-arterial contrast,arterial delineation,venous contamination,and confidence in diagnosis) were graded by 2 experienced doctors in consensus with the 5-point scale.Results The differences in age,gender,heart rates and body mass indexes were not significant among 3 groups(P > 0.05),and the examination of 183 cases were all successful with the image quality were not significant difference among 3 groups (P > 0.05).The CT values at right A2 segment,superior sagittal sinus and sigmoid sinus of group A were significantly lower than those of group B and C(t =-2.365,P =0.033; t =-2.576,P =0.021; t =-2.782,P=0.019; t =-3.014,P=0.006),whereas the remaining intracranial vessels were not significantly different among 3 groups (P > 0.05).In qualitative evaluation,arterial delineation in group B and C was better than that of group A,but intravenous contrast was less displayed in group A.Conclusion It is demonstrated that use of 50 mL(370 mgI / mL) contrast agent

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

    International Nuclear Information System (INIS)

    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

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

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    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

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

    International Nuclear Information System (INIS)

    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

  9. 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

    Institute of Scientific and Technical Information of China (English)

    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

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

    International Nuclear Information System (INIS)

    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)

  11. Peripheral Lung Adenocarcinoma versus Squamous Cell Carcinoma: Evaluation with First-pass Perfusion Imaging Using 64-detector Row CT%周围型肺腺癌与鳞癌64层螺旋CT首过时间灌注特征对比研究

    Institute of Scientific and Technical Information of China (English)

    李媛; 杨志刚; 陈天武; 余建群; 邓瑜萍; 李真林

    2009-01-01

    明确周围型肺腺癌与鳞癌首过时间CT灌注成像时间密度曲线及灌注值特征.对58例周围型肺腺癌和27例周围型肺鳞癌行64层螺旋CT首过时间灌注扫描,测定和评价病灶时间密度曲线(Time attenuation curve, TAC)、灌注值(perfusion)、强化峰值(PEI)、对比剂到达峰值时间(TTP)及血容量(BV)等灌注参数.周围型腺癌TACⅠ型占36.2%,Ⅱ型占63.8%;而周围型鳞癌TACⅠ型占22.2%,Ⅱ型占77.8%,两者构成比无显著差异(P>0.05).58例周围型腺癌首过时间CT perfusion值为63.2±45.4 ml·min-1·ml-1,PE值为60.2±46.6 Hu,TTP值为34.8±10.2 s,BV值为34.3±23.6 ml·100 g-1;27例周围型腺癌首过时间CT perfusion值为54.3±50.2 ml·min-1·ml-1,PE值为48.5±34.9 Hu,TTP值为36.1±11.2 s,BV值为27.6±21.7 ml·100g-1,两组间CT灌注值的差异均无统计学意义(P>0.05).表明周围型肺腺癌和鳞癌在TAC表现和CT灌注值均无显著差别.

  12. Estimation of organ-absorbed radiation doses during 64-detector CT coronary angiography using different acquisition techniques and heart rates: a phantom study

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    Matsubara, Kosuke; Koshida, Kichiro; Kawashima, Hiroko (Dept. of Quantum Medical Technology, Faculty of Health Sciences, Kanazawa Univ., Kanazawa (Japan)), email: matsuk@mhs.mp.kanazawa-u.ac.jp; Noto, Kimiya; Takata, Tadanori; Yamamoto, Tomoyuki (Dept. of Radiological Technology, Kanazawa Univ. Hospital, Kanazawa (Japan)); Shimono, Tetsunori (Dept. of Radiology, Hoshigaoka Koseinenkin Hospital, Hirakata (Japan)); Matsui, Osamu (Dept. of Radiology, Faculty of Medicine, Kanazawa Univ., Kanazawa (Japan))

    2011-07-15

    Background: Though appropriate image acquisition parameters allow an effective dose below 1 mSv for CT coronary angiography (CTCA) performed with the latest dual-source CT scanners, a single-source 64-detector CT procedure results in a significant radiation dose due to its technical limitations. Therefore, estimating the radiation doses absorbed by an organ during 64-detector CTCA is important. Purpose: To estimate the radiation doses absorbed by organs located in the chest region during 64-detector CTCA using different acquisition techniques and heart rates. Material and Methods: Absorbed doses for breast, heart, lung, red bone marrow, thymus, and skin were evaluated using an anthropomorphic phantom and radiophotoluminescence glass dosimeters (RPLDs). Electrocardiogram (ECG)-gated helical and ECG-triggered non-helical acquisitions were performed by applying a simulated heart rate of 60 beats per minute (bpm) and ECG-gated helical acquisitions using ECG modulation (ECGM) of the tube current were performed by applying simulated heart rates of 40, 60, and 90 bpm after placing RPLDs on the anatomic location of each organ. The absorbed dose for each organ was calculated by multiplying the calibrated mean dose values of RPLDs with the mass energy coefficient ratio. Results: For all acquisitions, the highest absorbed dose was observed for the heart. When the helical and non-helical acquisitions were performed by applying a simulated heart rate of 60 bpm, the absorbed doses for heart were 215.5, 202.2, and 66.8 mGy for helical, helical with ECGM, and non-helical acquisitions, respectively. When the helical acquisitions using ECGM were performed by applying simulated heart rates of 40, 60, and 90 bpm, the absorbed doses for heart were 178.6, 139.1, and 159.3 mGy, respectively. Conclusion: ECG-triggered non-helical acquisition is recommended to reduce the radiation dose. Also, controlling the patients' heart rate appropriately during ECG-gated helical acquisition with

  13. Multidetector-row CT for spinal diseases

    International Nuclear Information System (INIS)

    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)

  14. Experience with volumetric (320 rows) pediatric CT

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    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.

  15. Experience with volumetric (320 rows) pediatric CT

    International Nuclear Information System (INIS)

    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

  16. 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

    International Nuclear Information System (INIS)

    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

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

    International Nuclear Information System (INIS)

    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

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

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    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)

  19. 320-detector row CT coronary angiography in patients with arrhythmia

    International Nuclear Information System (INIS)

    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)

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

    International Nuclear Information System (INIS)

    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)

  1. Esophageal injuries: Spectrum of multidetector row CT findings

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    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.

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

    International Nuclear Information System (INIS)

    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.)

  3. 64排螺旋CT脑血管成像在烟雾病诊断中的应用价值%The application of 64 detector spiral CT brain angiography in the diagnosis of moyamoya disease

    Institute of Scientific and Technical Information of China (English)

    祝洪福; 任千里; 张芳; 王立乾

    2014-01-01

    Objective:To investigate the clinical value of 64 detector spiral CT angiography(CTA) in the diagnosis of moyamoya disease. Methods:The CT scan and CTA examination data of 16 cases with moyamoya disease were retrospectively analyzed. their imaging features were compared. Results:Cerebral hemorrhage in 8 cases. cerebral infarction in 2 cases. cerebral hemorrhage and infarction in 2 cases. and brain atrophy and cerebral hemorrhage in 2 cases were found,2 cases with no obvious abnormalities. The CTA showed that bilateral anterior and middle cerebral artery stenosis and occlusion in 4 cases and unilateral stenosis and occlusion in 3 cases. The different degree of stenosis and occlusion in bilateral internal carotid artery and C1. A1 or A1-A3 and M1 segment of anterior and middle cerebral artery of 9 cases were found. The merger of posterior cerebral artery stenosis in 3 cases and moyamoya in 16 cases were found. The large increasing and circuity and extending blood vessel in collateral vessels were showed. Conclusions:CTA is an efficient and practical technique in diagnosing moyamoya disease. which has great clinical value.%目的::探讨64排螺旋CT血管成像( CTA)在烟雾病诊断中的应用价值。方法:回顾CT平扫和CTA检查的16例烟雾病患者资料,分析其影像学特点。结果:脑出血8例,脑梗死2例,脑出血及脑梗死2例,脑萎缩及脑出血2例,2例未见明显异常。 CTA显示双侧大脑前中动脉狭窄、闭塞4例,单侧3例。双侧颈内动脉、大脑前、中动脉C1段、A1或A1~A3段、M1段不同程度狭窄、闭塞9例。合并大脑后动脉狭窄3例。16例均显示脑底异常血管网。侧支血管表现为相应血管及其分支粗大、增多,迂曲延长。结论:CTA可提供烟雾病确切的诊断,是一项实用、有效的技术,对烟雾病分析评价有重大临床价值。

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2009-03-15

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

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

    International Nuclear Information System (INIS)

    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)

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

    International Nuclear Information System (INIS)

    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)

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

    International Nuclear Information System (INIS)

    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

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

    International Nuclear Information System (INIS)

    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)

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

    Directory of Open Access Journals (Sweden)

    Atif N Khan

    2014-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    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.)

  11. Multidetector row-CT in evaluation of living renal donors

    Institute of Scientific and Technical Information of China (English)

    ZHANG Ji-qing; HU Xiao-peng; WANG Wei; LI Xiao-bei; YIN Hang; ZHANG Xiao-dong

    2010-01-01

    Background Multidetector-row CT (MDCT) has been evolving to the standard evaluating method of potential living donor in most centers, and can provide excellent details for selecting candidates and determining surgical technique.This study aimed to assess the value of MDCT in evaluation of the anatomy of living kidney donors and to reveal the prevalence of renal vascular variations in a Chinese population.Methods One hundred and four potential donors underwent MDCT and the data sets were post-processed for reformatted images with various techniques, such as maximum intensity projection (MIP), a volume-rendering technique (VR), and multiplanar reformation (MPR). Donor nephrectomies were performed on 97 candidates after MDCT evaluation with the findings during surgery constituting the standard of reference. Resulting MDCT images were compared with actual anatomy found during surgery. Results The MDCT images accurately displayed the anatomic structure of the main renal arteries and veins as well as the upper ureters, except in one case with horseshoe kidney. The prevalence of accessory arteries revealed in images was 27.2% (28/103) and early branching was found in 12.6% (13/103). Compared with findings during surgery, the detection of accessory arteries in MDCT images was 85.7% (6/7), and the detection of larger accessory arteries (>1.5 mm in diameter) was 100%. Detection of early branching was 100%.Conclusion MDCT helps accurately evaluate the renal anatomy of potential donors thus facilitating the planning of surgery.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2008-03-15

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

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

    International Nuclear Information System (INIS)

    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.)

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

    International Nuclear Information System (INIS)

    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

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

    International Nuclear Information System (INIS)

    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

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

    International Nuclear Information System (INIS)

    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.)

  17. Multislice CT of the pelvis: dose reduction with regard to image quality using 16-row CT

    Energy Technology Data Exchange (ETDEWEB)

    Gurung, Jessen; Khan, M. Fawad; Maataoui, Adel; Herzog, C.; Vogl, Thomas J. [Johann Wolfgang Goethe University, Institute for Diagnostic and Interventional Radiology, Frankfurt am Main (Germany); Bux, R.; Bratzke, H. [Johann Wolfgang Goethe University, Institute for Forensic Medicine, Frankfurt am Main (Germany); Ackermann, Hanns [Johann Wolfgang Goethe University, Institute for Epidemiology and Medical Statistics, Frankfurt am Main (Germany)

    2005-09-01

    To optimize examination protocols of 16-row multi-detector CT (MDCT) of pelvis for dose reduction with regard to image quality. MDCT of pelvis was performed on 12 cadaver specimens with stepwise reduction of tube current from 160 mA (113, 80, 56, 40, 28) to 20 mA at 120 kV. Scan parameters were 16 x 1.5 mm collimation. Reconstructions of axial and coronal images were used for evaluation of cortex, trabeculum, image quality, image noise, acetabulum and iliosacral (ISJ) joints. After data were blinded, evaluation of images was done by three radiologists according to 5-point Likert scale. Accuracy of the observers in sorting films according to dose reduction was determined with kappa coefficient. Mean values of image evaluation were determined. Pronounced deterioration of image quality for all criteria was observed between 80 and 28 mA. Adequate image quality was obtained at 40 mA [effective dose (E): 2.2 mSv, CTDI{sub w}: 2.8 mGy] for criterion detailed definition of acetabulum and ISJ and at 80 mA (E: 4.4 mSv, CTDI{sub w}: 5.6 mGy) for remaining criteria. Moderate agreement was observed between the three observers (kappa coefficient: 0.31). All observers were excellent in arranging images according to decreasing dose. Using 16-row MDCT image quality of pelvis is acceptable at 80 mA and 120 kV. This translates into a dose reduction of 33% of average value of the nationwide survey of the German Roentgen Society (1999) for this type of examination. (orig.)

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

    International Nuclear Information System (INIS)

    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)

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

    NARCIS (Netherlands)

    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

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

    International Nuclear Information System (INIS)

    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)

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    International Nuclear Information System (INIS)

    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

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

    International Nuclear Information System (INIS)

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-11-15

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

  5. Comparison of cerebral blood flow data obtained by computed tomography (CT) perfusion with that obtained by xenon CT using 320-row CT.

    Science.gov (United States)

    Takahashi, Satoshi; Tanizaki, Yoshio; Kimura, Hiroaki; Akaji, Kazunori; Kano, Tadashige; Suzuki, Kentaro; Takayama, Youhei; Kanzawa, Takao; Shidoh, Satoka; Nakazawa, Masaki; Yoshida, Kazunari; Mihara, Ban

    2015-03-01

    Cerebral blood flow (CBF) data obtained by computed tomography perfusion (CTP) imaging have been shown to be qualitative data rather than quantitative, in contrast with data obtained by other imaging methods, such as xenon CT (XeCT) imaging. Thus, interpatient comparisons of CBF values themselves obtained by CTP may be inaccurate. In this study, we have compared CBF ratios as well as CBF values obtained from CTP-CBF data to those obtained from XeCT-CBF data for the same patients to determine CTP-CBF parameters that can be used for interpatient comparisons. The data used in the present study were obtained as volume data using 320-row CT. The volume data were applied to an automated region of interest-determining software (3DSRT, version 3.5.2 ) and converted to 59 slices of 2 mm interval standardized images. In the present study, we reviewed 10 patients with occlusive cerebrovascular diseases (CVDs) undergoing both CTP and XeCT in the same period. Our study shows that ratios of CBF measurements, such as hemodynamic stress distribution (perforator-to-cortical flow ratio of middle cerebral artery [MCA] region) or the left/right ratio for the region of the MCA, calculated using CTP data have been shown to correlate well with the same ratios calculated using XeCT data. These results suggest that such CBF ratios could be useful for generating interpatient comparisons of CTP-CBF data obtained by 320-row CT among patients with occlusive CVD.

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

    Science.gov (United States)

    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

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

    International Nuclear Information System (INIS)

    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.)

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

    International Nuclear Information System (INIS)

    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

  9. Assessment of 82 Live Potential Renal Donors with Multi Detector Row Helical CT Angiography (MDCTA

    Directory of Open Access Journals (Sweden)

    R. Javadrashid

    2008-01-01

    Full Text Available Background/Objective: To retrospectively review the authors' experience with multi-detector row helical computed tomography (CT in assessing 82 consecu-tive alive potential renal donors."nPatients and Methods: Eighty-two potential renal donors underwent multi-detector row CT assess-ment, using a 64-slice scanner (Somatom Sensation, Siemens with 0.6-mm slice thickness followed by maximum intensity projection and volume rendering techniques post-processing algorithms. Arterial phase and venous phase examinations were performed. De-layed tomograms were acquired to visualize the col-lecting system anatomy. Two vascular radiologists prospectively interpreted the multi-detector row CT images. Forty candidates subsequently underwent donor nephrectomy. Surgical findings served as the reference standard for 40 kidneys. The imaging find-ings in all 82 candidates (164 kidneys were reviewed, although these findings were considered observa-tional data only because there was no reference stan-dard for 124 kidneys."nResults: Identification of vascular anomalies was best on direct viewing of the axial images using interactive scrolling through the images and cine-loop paging. In 164 kidneys evaluated, a single renal artery was pre-sent in 74.5% and a single renal vein in 87.5%. Mul-tiple renal arteries were more common on the right side (37.8% vs. the left side (20.7%. Early branching of the arteries was seen with equal frequency (10% on either side. Multiple renal veins were more often on the right side (20% vs. the left side (5%. CT an-giographic findings were concordant with the intra-operative findings in 100% of the cases that under-went nephrectomy. CT also revealed cortical cysts (four cases, duplex collecting system (two cases, hy-dronephrosis (one case, renal stone (one case, and liver hemangiomas (two cases. There was no signifi-cant interobserver disagreement between the vascular radiologists."nConclusion: CT angiography is highly accurate for

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

    International Nuclear Information System (INIS)

    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

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

    International Nuclear Information System (INIS)

    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.)

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

    International Nuclear Information System (INIS)

    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)

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

    DEFF Research Database (Denmark)

    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....... Median Agatston score was 510. Two data sets were reconstructed: a conventional CCTA (CCTAconv) and a subtracted CCTA (CCTAsub), where calcifications detected on noncontrast images were subtracted from the CCTA. Reader confidence and concordance with ICA for identification of >50% stenosis were recorded....... We defined target segments on CCTAconv as motion-free coronary segments with calcification or stent and low reader confidence. The effect of CCTAsub was assessed. No approval from the ethics committee was required according to Danish law. RESULTS: A total of 76 target segments were identified...

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

    OpenAIRE

    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...

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

    OpenAIRE

    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...

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

    Energy Technology Data Exchange (ETDEWEB)

    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.)

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

    International Nuclear Information System (INIS)

    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.)

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

    International Nuclear Information System (INIS)

    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

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

    International Nuclear Information System (INIS)

    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.)

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

    International Nuclear Information System (INIS)

    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

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

    International Nuclear Information System (INIS)

    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)

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-02-15

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

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

    International Nuclear Information System (INIS)

    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.

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

    International Nuclear Information System (INIS)

    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

    Energy Technology Data Exchange (ETDEWEB)

    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

    International Nuclear Information System (INIS)

    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

    International Nuclear Information System (INIS)

    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

    Energy Technology Data Exchange (ETDEWEB)

    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

    International Nuclear Information System (INIS)

    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. Evaluation of angiogenesis in colorectal carcinoma with multidetector-row CT multislice perfusion imaging

    Energy Technology Data Exchange (ETDEWEB)

    Feng Shiting, E-mail: fst1977@163.co [Department of Radiology, First Affiliated Hospital of SunYat-sen University, Guangzhou 510080 (China); Sun Canhui, E-mail: canhuisun@sina.co [Department of Radiology, First Affiliated Hospital of SunYat-sen University, Guangzhou 510080 (China); Li Ziping, E-mail: liziping163@tom.co [Department of Radiology, First Affiliated Hospital of SunYat-sen University, Guangzhou 510080 (China); Mak, Henry Ka-Fung, E-mail: makkf@hkucc.hku.h [Department of Diagnostic Radiology, University of Hong Kong, Hong Kong (China); Peng Zhenpeng, E-mail: ppzhen@21cn.co [Department of Radiology, First Affiliated Hospital of SunYat-sen University, Guangzhou 510080 (China); Guo Huanyi, E-mail: guohuanyi@163.co [Department of Radiology, First Affiliated Hospital of SunYat-sen University, Guangzhou 510080 (China); Meng Quanfei, E-mail: mzycoco@gmail.co [Department of Radiology, First Affiliated Hospital of SunYat-sen University, Guangzhou 510080 (China)

    2010-08-15

    To evaluate the correlation between 64 multidetector-row CT (64MDCT) perfusion imaging in colorectal carcinoma and microvessel density (MVD) and vascular endothelial growth factor (VEGF), 64MDCT perfusion imaging was performed in 33 patients with pathologically verified colorectal carcinoma. These images were analyzed with perfusion functional software, and time-density curves (TDC) were created for the region of interest (ROI) encompassing the tumor, the target artery and vein. The individual perfusion maps generated indicated blood flow (BF), blood volume (BV), mean transit time (MTT), and permeability-surface area product (PS). MVD and VEGF were evaluated by immunohistochemical staining with anti-CD34 and anti-VEGF, respectively. Correlations between MVD or VEGF with CT perfusion parameters and clinicopathological factors (Dukes' stages, invasion depth, and lymph node and liver metastasis) were also investigated. MVD in the colorectal carcinoma was 22.61 {+-} 9.01 per x200 field. The scores obtained for VEGF expression were 4.15 {+-} 1.09. VEGF staining was positive in 25 of 29 tumors (86.2%). There was no significant correlation between the presence of MVD, VEGF expression and clinicopathological factors (P > 0.05). There was also no correlation between MVD, VEGF expression, and any dynamic CT parameters (P > 0.05). The BV and MTT were significantly higher in tumors demonstrating serous coat invasion than in those without it (t = -2.63, -2.24, P = 0.0137, 0.0331, respectively). BV was also significantly correlated with tumor size (r = 0.41, P = 0.02). Neither BF nor PS was correlated with clinicopathological factors. In conclusion, 64MDCT perfusion imaging, MVD, and VEGF may reflect angiogenic activity, but no significant correlation among these factors.

  11. Multi-detector row CT scanning in Paleoanthropology at various tube current settings and scanning mode.

    Science.gov (United States)

    Badawi-Fayad, J; Yazbeck, C; Balzeau, A; Nguyen, T H; Istoc, A; Grimaud-Hervé, D; Cabanis, E- A

    2005-12-01

    The purpose of this study was to determine the optimal tube current setting and scanning mode for hominid fossil skull scanning, using multi-detector row computed tomography (CT). Four fossil skulls (La Ferrassie 1, Abri Pataud 1, CroMagnon 2 and Cro-Magnon 3) were examined by using the CT scanner LightSpeed 16 (General Electric Medical Systems) with varying dose per section (160, 250, and 300 mAs) and scanning mode (helical and conventional). Image quality of two-dimensional (2D) multiplanar reconstructions, three-dimensional (3D) reconstructions and native images was assessed by four reviewers using a four-point grading scale. An ANOVA (analysis of variance) model was used to compare the mean score for each sequence and the overall mean score according to the levels of the scanning parameters. Compared with helical CT (mean score=12.03), the conventional technique showed sustained poor image quality (mean score=4.17). With the helical mode, we observed a better image quality at 300 mAs than at 160 in the 3D sequences (P=0.03). Whereas in native images, a reduction in the effective tube current induced no degradation in image quality (P=0.05). Our study suggests a standardized protocol for fossil scanning with a 16 x 0.625 detector configuration, a 10 mm beam collimation, a 0.562:1 acquisition mode, a 0.625/0.4 mm slice thickness/reconstruction interval, a pitch of 5.62, 120 kV and 300 mAs especially when a 3D study is required. PMID:16211320

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

    International Nuclear Information System (INIS)

    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

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

    Science.gov (United States)

    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

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

    International Nuclear Information System (INIS)

    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)

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

    International Nuclear Information System (INIS)

    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

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

    International Nuclear Information System (INIS)

    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.)

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

    International Nuclear Information System (INIS)

    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

  18. Optimized image reconstruction for detection of deep venous thrombosis at multidetector-row CT venography

    Energy Technology Data Exchange (ETDEWEB)

    Das, Marco; Muehlenbruch, Georg; Mahnken, Andreas Horst; Guenther, Rolf W.; Wildberger, Joachim Ernst [University Hospital, University of Technology (RWTH), Department of Diagnostic Radiology, Aachen (Germany); Weiss, Claudia [RWTH Aachen, Institute of Medical Statistics, Aachen (Germany); Schoepf, U. Joseph [Medical University of South Carolina, Department of Radiology, Charleston, SC (United States); Leidecker, Christianne [Institute of Medical Physics, University of Erlangen, Erlangen (Germany)

    2006-02-01

    The aims of this study were to optimize image quality for indirect CT venography (sequential versus spiral), and to evaluate different image reconstruction parameters for patients with suspected deep venous thrombosis (DVT). Fifty-one patients (26/25 with/without DVT) were prospectively evaluated for pulmonary embolism (PE) with standard multidetector-row computed tomography (MDCT) protocols. Retrospective image reconstruction was done with different slice thicknesses and reconstruction increments in sequential and spiral modes. All reconstructions were read for depiction of DVT and to evaluate best reconstruction parameters in comparison with the thinnest reconstruction (''gold standard''). Image noise and venous enhancement were measured as objective criteria for image quality. Subjective image quality was rated on a four-point scale. Effective dose was estimated for all reconstructions. In sequential 10/50 reconstruction DVT was completely detected in 13/26 cases, partially in 10/26 cases and was not detected at all in 3/26 cases, and 15/26, 9/26 and 2/26 cases for the 10/20 reconstruction, respectively. DVT was completely detected in all spiral reconstructions. Image noise ranged between 14.8-29.1 HU. Median image quality was 2. Estimated effective dose ranged between 2.3 mSv and 11.8 mSv. Gaps in sequential protocols may lead to false negative results. Therefore, spiral scanning protocols for complete depiction of DVT are mandatory. (orig.)

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

    International Nuclear Information System (INIS)

    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

  20. Carotid artery wall thickness and ischemic symptoms: evaluation using multi-detector-row CT angiography

    Energy Technology Data Exchange (ETDEWEB)

    Saba, Luca; Caddeo, Giancarlo; Mallarini, Giorgio [Azienda Ospedaliero Universitaria Polo di Monserrato, Department of Radiology, Cagliari (Italy); Sanfilippo, Roberto; Montisci, Roberto [Azienda Ospedaliero Universitaria Polo di Monserrato, Department of Vascular Surgery, Cagliari (Italy); Pascalis, Luigi [Azienda Ospedaliero Universitaria Polo di Cagliari, Division of II Internal Medicine, Cagliari (Italy)

    2008-09-15

    The purpose of this study was to determine if carotid artery wall thickness (CAWT) studied by using multi-detector-row CT angiography (MDCTA) can be considered an effective parameter predictive of increased risk of stroke. A total of 217 patients were retrospectively studied by using MDCTA. In all patients CAWT was measured with an internal digital caliper. Continuous data were described as the mean value {+-} standard deviation (SD), and they were compared with Student's t-test. Scatter plots to determine interobserver agreement were performed, and correlation coefficient was calculated with Pearson statistics. A P value <0.05 was considered to mean statistical significance. Measurements of the distal common CAWT ranged from 0.5 to 1.6 mm. In the patient group without stroke, average CAWT was 0.82 mm (0.22 SD), whereas in patient group with stroke it was 1.096 mm (0.21 SD). CAWT in patients without stroke showed statistical difference (P<0.0001) when compared to patients with stroke. By using a threshold of 1 mm, an important statistical association between thick CAWT and stroke was found (P<0.0001). In fact, patients with {>=}1 mm CAWT had stroke with an odds ratio of 8.16 when compared with patients with <1 mm CAWT. Resulting data suggested that an increased CAWT is an indicator for risk of stroke. This parameter should be considered in addition to other well-known risk factors such as diabetes, hypertension, smoking, and dyslipidemia. (orig.)

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

    International Nuclear Information System (INIS)

    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

  2. Image analysis of intracranial high perfusion lesion by whole brain one-stop imaging technique with 320 detector rows CT

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    Fei-zhou DU

    2014-03-01

    Full Text Available Objective  The perfusion and vascular architecture features were investigated and evaluated by use of one-stop imaging technique with 320 rows CT for exploring the clinical value of one-stop imaging technique in the diagnosis of intracranial lesions. Methods  The perfusion parameters and vascular architecture of intracranial high perfusion lesions of 52 patients were collected in General Hospital of Chengdu Command from Oct. 2010 to Apr. 2013, who were examined by one-stop imaging technique with 320 rows CT, were retrospectively analyzed. The perfusion values of normal contralateral cerebral tissue were used as control to analyze the perfusion and vascular architecture features of injured parts. Results  Of the 52 patients, there were 16 cases of subacute cerebral infarction, 9 cases of arteriovenous malformation, 7 cases of hemangioma, 12 cases of meningioma, and 8 cases of glioma. All the patients showed elevated CBV and/or CBF and different changes in mean transit time (MTT, time to peak (TTP and delay time (Delay. In the cases of subacute cerebral infarction, the parameters of MTT, TTP and Delay increased. In the cases of arteriovenous malformation, all the parameters decreased. In the cases of hemangioma, the MTT decreased, while TTP and Delay increased. In the cases of glioma, the TTP and Delay increased, while the change of MTT varied. Meanwhile, abnormality of vascular structures was found in all the cases by CT angiography. Conclusion  With whole brain perfusion and one-stop vascular imaging with 320 rows CT, the perfusion characteristics of intracranial lesions can be revealed completely, including blood supply and microcirculation changes in the lesions, and it may be of benefit in guiding the clinical diagnosis and treatment. DOI: 10.11855/j.issn.0577-7402.2014.03.10

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

    International Nuclear Information System (INIS)

    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)

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

    Energy Technology Data Exchange (ETDEWEB)

    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.)

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

    International Nuclear Information System (INIS)

    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.)

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

    International Nuclear Information System (INIS)

    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

  7. 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

    International Nuclear Information System (INIS)

    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.

  8. 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

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-08-15

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

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

    International Nuclear Information System (INIS)

    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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2006-05-15

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

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

    International Nuclear Information System (INIS)

    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)

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

    OpenAIRE

    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 ...

  15. The diagnostic accuracy of multidetector row CT for evaluating the axillary lymph nodes in patients with breast cancer

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Doo Kyung; Kim, Jun Man; Yim, Hyun Ee [Ajou University, College of Medicine, Suwon (Korea, Republic of)

    2007-08-15

    We investigated the CT (computed tomography) findings of metastatic lymph nodes (LNs), and we analyzed the diagnostic performance of multidetector row CT (MDCT) for detecting axillary LN metastases in patients with breast cancer. We investigated 59 patients who preoperatively underwent chest MDCT, and they underwent sentinel LN biopsy ro whole axillary LN dissection. We analyzed the morphologic features, the degree of enhancement and the delayed enhancement pattern. We classified the patients into the non-metastatic LN group and the metastatic LN group, and we calculated the diagnostic performance of MDCT for detecting metastatic LNs. When both the morphologic and quantitative criteria were consistent, the sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were 58.1%, 100%, 100% and 68.3%, respectively, and MDCT accurately detected metastatic LNs in 2 patients that were false negative on sentinel LN biopsy. When the morphologic and quantitative criteria were consistent, the sensitivity, specificity, PPV and NPV were 87.1%, 53.6%, 67.5% and 78.9%, respectively. However, MDCT could not detect metastatic LNs, including two micrometastases (a total of 8 micrometastases) that were in each of four patients. MDCT can be used to perform the morphology and quantitative analysis of axillary LNs, and this modality has excellent specificity and a PPV for detecting metastatic LNs when the both of the diagnostic criteria are consistent.

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

    International Nuclear Information System (INIS)

    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

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

    International Nuclear Information System (INIS)

    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.)

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

    International Nuclear Information System (INIS)

    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.)

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-08-06

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

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

    Energy Technology Data Exchange (ETDEWEB)

    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

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.)

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2011-09-15

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

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

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    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.

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

    International Nuclear Information System (INIS)

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

    International Nuclear Information System (INIS)

    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.)

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

    Directory of Open Access Journals (Sweden)

    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

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

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    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.)

  9. Technical note: Electrocardiogram electrode repositioning for 320-row coronary CT angiography in patients with regular and recurrent premature ventricular contractions.

    Science.gov (United States)

    Kondo, Takeshi; Matsutani, Hideyuki; Groarke, John; Takamura, Kazuhisa; Fujimoto, Shinichiro; Rybicki, Frank J; Kumamaru, Kanako K

    2014-01-01

    Arrhythmias can compromise image quality and increase radiation exposure during coronary CT angiography (CTA). However, premature ventricular contractions (PVCs) can occur in a predictable recurrent and regular pattern (ie, bigeminy, trigeminy, quadrigeminy) with post-PVC compensatory pauses. Electrocardiographic (ECG) electrode repositioning can achieve relative amplification of the R waves of PVCs compared with R waves of sinus beats. This technical note describes how simple ECG electrode repositioning, combined with an absolute-delay strategy, facilitated selective R waves of PVC ECG triggering of image acquisition in 6 patients with PVC bigeminy or quadrigeminy at the time of 320-row coronary CTA. All 6 studies were single heartbeat acquisition scans with excellent image quality and a median effective radiation dose of 2.9 mSv (interquartile range, 2.1-3.8 mSv). Standard ECG electrode positions used for 2 patients with PVC bigeminy undergoing coronary CTA were associated with an acquisition over 2 heartbeats and effective radiation doses of 6.8 and 10.3 mSv, respectively. In conclusion, ECG electrode repositioning combined with an absolute-delay strategy for regularly recurring PVCs, such as ventricular bigeminy, facilitates high image quality and lower radiation dose during coronary CTA. This simple and straightforward technique can be considered for all patients with regular and recurrent PVCs undergoing coronary CTA.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2008-07-15

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

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

    International Nuclear Information System (INIS)

    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.)

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

    International Nuclear Information System (INIS)

    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

    Energy Technology Data Exchange (ETDEWEB)

    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

    International Nuclear Information System (INIS)

    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

    International Nuclear Information System (INIS)

    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

    International Nuclear Information System (INIS)

    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. Influence of 320-detector-row volume scanning and AAPM report 111 CT dosimetry metrics on size-specific dose estimate: a Monte Carlo study.

    Science.gov (United States)

    Haba, Tomonobu; Koyama, Shuji; Kinomura, Yutaka; Ida, Yoshihiro; Kobayashi, Masanao

    2016-09-01

    The American Association of Physicists in Medicine (AAPM) task group 204 has recommended the use of size-dependent conversion factors to calculate size-specific dose estimate (SSDE) values from volume computed tomography dose index (CTDIvol) values. However, these conversion factors do not consider the effects of 320-detector-row volume computed tomography (CT) examinations or the new CT dosimetry metrics proposed by AAPM task group 111. This study aims to investigate the influence of these examinations and metrics on the conversion factors reported by AAPM task group 204, using Monte Carlo simulations. Simulations were performed modelling a Toshiba Aquilion ONE CT scanner, in order to compute dose values in water for cylindrical phantoms with 8-40-cm diameters at 2-cm intervals for each scanning parameter (tube voltage, bow-tie filter, longitudinal beam width). Then, the conversion factors were obtained by applying exponential regression analysis between the dose values for a given phantom diameter and the phantom diameter combined with various scanning parameters. The conversion factors for each scanning method (helical, axial, or volume scanning) and CT dosimetry method (i.e., the CTDI100 method or the AAPM task group 111 method) were in agreement with those reported by AAPM task group 204, within a percentage error of 14.2 % for phantom diameters ≥11.2 cm. The results obtained in this study indicate that the conversion factors previously presented by AAPM task group 204 can be used to provide appropriate SSDE values for 320-detector-row volume CT examinations and the CT dosimetry metrics proposed by the AAPM task group 111.

  18. Influence of 320-detector-row volume scanning and AAPM report 111 CT dosimetry metrics on size-specific dose estimate: a Monte Carlo study.

    Science.gov (United States)

    Haba, Tomonobu; Koyama, Shuji; Kinomura, Yutaka; Ida, Yoshihiro; Kobayashi, Masanao

    2016-09-01

    The American Association of Physicists in Medicine (AAPM) task group 204 has recommended the use of size-dependent conversion factors to calculate size-specific dose estimate (SSDE) values from volume computed tomography dose index (CTDIvol) values. However, these conversion factors do not consider the effects of 320-detector-row volume computed tomography (CT) examinations or the new CT dosimetry metrics proposed by AAPM task group 111. This study aims to investigate the influence of these examinations and metrics on the conversion factors reported by AAPM task group 204, using Monte Carlo simulations. Simulations were performed modelling a Toshiba Aquilion ONE CT scanner, in order to compute dose values in water for cylindrical phantoms with 8-40-cm diameters at 2-cm intervals for each scanning parameter (tube voltage, bow-tie filter, longitudinal beam width). Then, the conversion factors were obtained by applying exponential regression analysis between the dose values for a given phantom diameter and the phantom diameter combined with various scanning parameters. The conversion factors for each scanning method (helical, axial, or volume scanning) and CT dosimetry method (i.e., the CTDI100 method or the AAPM task group 111 method) were in agreement with those reported by AAPM task group 204, within a percentage error of 14.2 % for phantom diameters ≥11.2 cm. The results obtained in this study indicate that the conversion factors previously presented by AAPM task group 204 can be used to provide appropriate SSDE values for 320-detector-row volume CT examinations and the CT dosimetry metrics proposed by the AAPM task group 111. PMID:27444155

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

    International Nuclear Information System (INIS)

    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.

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

    Directory of Open Access Journals (Sweden)

    Daniela Stoisa

    2009-03-01

    Full Text Available Objetivo: Mostrar las diversas variantes anatómicas vasculares tanto arteriales como venosas en el estudio angiográfico renal por tomografìa computada multidetector (TCMD de 64 canales, dada su implicancia en un eventual planeamiento quirúrgico. Material y métodos: Evaluamos retrospectivamente 26 estudios realizados con tomógrafo Philips Brilliance de 64 canales. Se obtuvieron secuencias sin contraste y postcontraste e.v. en fases arterial y venosa, administrado con bomba inyectora doble cabezal. Para una fase arterial apropiada se utilizó técnica de bolus track. Las imágenes fueron posteriormente procesadas en Workstation Philips Brilliance 190P en un tiempo promedio de 30 minutos y reconstruidas con técnicas MIP y volumétrica. Resultados: Dentro de las variantes anatómicas arteriales, encontramos: bifurcaciones prehiliares (n=3, arterias accesorias (n=4 y arterias polares (n=9. Dentro de las variantes venosas fueron halladas: venas renales múltiples (n=5, venas circumaórticas (n=2, retroaórticas (n=2 y vena tributaria lumbar prominente (n=1. Conclusión: El estudio vascular renal adquiere importancia en el planeamiento quirúrgico en casos de nefrectomías parciales, laparoscópicas y en el transplante renal. Esto otorga suma utilidad al estudio de TCMD de 64 canales por su eficacia diagnóstica, dada la alta calidad de las reconstrucciones obtenidas, llegando a igualar a la angiografía digital, sin ser un método invasivo.Purpose: To show the wide range of anatomical vascular variants, arterial and venous, that can be seen in the angiographic renal study using 64-multidetector-row computed tomography (64-MDCT, due to its importance in an eventual surgical planning. Material and Methods: We have evaluated retrospectively 26 studies that have been done using a 64 channels Philips Brilliance CT scanner. We have obtained non enhanced and both in arterial and venous enhanced sequences. For the injection of the contrast material we

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

    International Nuclear Information System (INIS)

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

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, WeiGuo [The First Affiliated Hospital of Soochow University, Department of Radiology, SuZhou (China); Fudan University, Department of Radiology, Zhongshan Hospital, Shanghai (China); Jin, Hang; Chen, Gang; Chen, Wenfang; Gu, Junying; Zeng, Mengsu [Fudan University, Department of Radiology, Zhongshan Hospital, Shanghai (China)

    2014-07-15

    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.)

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

    International Nuclear Information System (INIS)

    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.)

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

    International Nuclear Information System (INIS)

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    International Nuclear Information System (INIS)

    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.)

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

    International Nuclear Information System (INIS)

    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

  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

    International Nuclear Information System (INIS)

    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. 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

    Energy Technology Data Exchange (ETDEWEB)

    Motosugi, Utaroh, E-mail: utaroh-motosugi@nifty.com [Department of Radiology, University of Yamanashi, 1110 Shimokato, Chuo-shi, Yamanashi (Japan); Ichikawa, Tomoaki, E-mail: ichikawa@yamanashi.ac.jp [Department of Radiology, University of Yamanashi, 1110 Shimokato, Chuo-shi, Yamanashi (Japan); Sou, Hironobu, E-mail: fffun0300@yahoo.ac.jp [Department of Radiology, University of Yamanashi, 1110 Shimokato, Chuo-shi, Yamanashi (Japan); Morisaka, Hiroyuki, E-mail: morisakahiroyuki@hotmail.co.jp [Department of Radiology, University of Yamanashi, 1110 Shimokato, Chuo-shi, Yamanashi (Japan); Sano, Katsuhiro, E-mail: snkthr@yahoo.co.jp [Department of Radiology, University of Yamanashi, 1110 Shimokato, Chuo-shi, Yamanashi (Japan); Araki, Tsutomu, E-mail: arakit@yamanashi.ac.jp [Department of Radiology, University of Yamanashi, 1110 Shimokato, Chuo-shi, Yamanashi (Japan)

    2012-10-15

    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{sup −1} 100 mL{sup −1}, respectively) was significantly less than that in patients without cirrhosis (213 and 174 mL min{sup −1} 100 mL{sup −1}, respectively; p = 0.0081 and 0.0294, respectively). Arterial perfusion of the spleen (111 mL min{sup −1} 100 mL{sup −1}) and the body of the pancreas (112 mL min{sup −1} 100 mL{sup −1}) in patients with cirrhosis was also significantly decreased compared with that in patients without cirrhosis (spleen, 162 mL min{sup −1} 100 mL{sup −1}, p = 0.0020; body of pancreas, 133 mL min{sup −1} 100 mL{sup −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.

  10. Diagnostic Value of 16-row CT Angiography in Aortic Dissection%16排CT血管成像对主动脉夹层的诊断价值

    Institute of Scientific and Technical Information of China (English)

    曹禹

    2012-01-01

    Objective: To evaluate the diagnostic value of 16-row angiography in aortic dissection. Methods:32 cases of patients recieved with aortic dissection from June.2010. to April.2012 were selected for the 16-row CT scan and combined with angiography processing method for diagnosis. Results: The classification of aortic dissection of this group cases as follows:9 cases for type I (28.1%),4 cases for type II (12.5%),19 cases for type III (59.4%). In the plain 16-row CT scan of this group cases,11 cases of patients with vascular intima calcification displace to the cavity larger than 5mm(34.3%). All cases of this group performed enhanced angiography, and showed tearing intimal flap, presented linear low density image, tomography presented an arc image,reconstructed two dimensional images presented a straight-line or spiral low density linear image. Conclusion: In the clinical diagnosis of aortic dissection patients,16-row angiography technique has a rapid, accurate and non-invasive advantage, and could be the preferred method for diagnosis.%目的探讨16排CT血管成像对主动脉夹层的诊断价值.方法选取本组2010年6月到2012年4月收治的主动脉夹层患者32例,均行16排CT扫描,并结合相关血管成像处理方法进行诊断.结果本组病例的主动脉夹层分型结果为:Ⅰ型9例(28.1%),Ⅱ型4例(12.5%),Ⅲ型19例(59.4%).在本组病例的16排CT平扫中,血管内膜钙化向腔内移位≥5mm者11例(34.3%).本组病例均行血管造影增强扫描,全部显示撕裂的内膜片,呈现线形低密度影,断层像上呈现弧形,二维重建像呈现直线状或螺旋状低密度线状影.结论在主动脉夹层患者的临床诊断中,16排CT血管成像技术的应用具有准确、快速、无创等优点,可以作为首选的诊断方法.

  11. 320层容积CT心肌灌注成像对心肌灌注缺损的诊断价值%Detection of myocardial perfusion defect with 320-row volume CT myocardial perfusion imaging

    Institute of Scientific and Technical Information of China (English)

    张传臣; 张兆琪; 王蒨; 徐磊; 于薇; 焦健; 王瑞

    2012-01-01

    目的 探讨320层容积CT心肌灌注成像(CT-MPI)的可行性及其对心肌灌注缺损的诊断价值.方法 对14例经SPECT心肌灌注成像(SPECT-MPI)阳性的已知或可疑冠心病患者行静息和腺苷负荷320层容积CT-MPI检查,使用专用心肌灌注软件对CT-MPI进行分析.以心肌16节段标准分段方法(心尖除外)分别分析核素和容积CT-MPI的固定或可逆性灌注缺损.以SPECT-MPI为参考标准评价CT-MPI对心肌灌注缺损诊断的敏感度、特异度.结果 所有患者均成功完成320层容积CT-MPI.SPECT-MPI显示14例患者中共有39段心肌出现固定或可逆性灌注缺损,CT-MPI正确显示了其中12例患者的34段心肌灌注缺损.320层容积CT-MPI诊断心肌灌注缺损的敏感度、特异度分别为87.2%( 34/39)和91.4%(169/185).结论 320层容积CT-MPI对诊断心肌灌注缺损有较高的敏感度和特异度.%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

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

    International Nuclear Information System (INIS)

    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

  13. 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

    International Nuclear Information System (INIS)

    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)

  14. Rowing Injuries

    OpenAIRE

    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...

  15. 急性脑梗死320排 CT 脑灌注成像分析%The analysis of whole-brain CT perfusion imaging with 320-detector row CT in acute cerebral infarction

    Institute of Scientific and Technical Information of China (English)

    阮志兵; 段庆红

    2014-01-01

    Objective To explore the clinical value of whole-brain CT perfusion imaging with 320-detector row CT in early acute cerebral infarction.Methods The CTP parameters(CBF,CBV,MTT,TTP)and its pseudo color map of 25 patients with early acute cerebral infarction were retrospectively analysed and compared between infarction area,ischemic penumbra (IP)and the con-tralateral normal region.Results The abnormal perfusion area were found on CTP in 25 patients with early acute cerebral infarction. CTP showed cerebral blood flow (CBF)and cerebral blood volume (CBV)decreased significantly,mean transit time (MTT)short-ened significantly,time to peak (TTP)was significantly longer than those of the contralateral normal region in 7 cases of acute cere-bral infarct core.18 cases of IP lesions showed CBF decreased slightly,CBV increased slightly or maintain normal,MTT and TTP extension compared with contralateral.CBF,CBV,MTT,TTP values had significantly differences between infarct region and the contralateral corresponding normal region,between the infarct core area and IP of acute cerebral infarction (P 0.05)between IP region and the contralateral corresponding normal region,but showed a downward trend in blood flow.Parameter color maps of CTP could di-rectly,clearly and sensitively show abnormal changes region about cerebral blood flow.In particular,MTT and TTP maps shows ab-normal region clearer and sensitively.Follow-up 18 cases of IP,active lesions deduced in 6 cases,the lesions disappeared in 5 pa-tients (CT/ MRI showed no abnormal,and the clinical symptoms disappeared)after thrombolytic therapy,7 cases of MRI and CT scans confirmed infarction stove.Conclusion Whole-brain CTP with 320-detector row CT can early show the acute cerebral infarc-tion and its ischemic penumbra,it has significant important clinical value for early acute cerebral infarction.%目的:探讨320排 CT 全脑灌注成像(CTP)在早期急性脑梗死中的临床应用价值。方法回顾性分析25

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    International Nuclear Information System (INIS)

    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

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  19. 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

    International Nuclear Information System (INIS)

    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.)

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

    International Nuclear Information System (INIS)

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

    International Nuclear Information System (INIS)

    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.)

  2. Quantification of myocardial blood flow using dynamic 320-row multi-detector CT as compared with {sup 15}O-H{sub 2}O PET

    Energy Technology Data Exchange (ETDEWEB)

    Kikuchi, Yasuka; Oyama-Manabe, Noriko; Kudo, Kohsuke [Hokkaido University Hospital, Department of Diagnostic and Interventional Radiology, Sapporo (Japan); Naya, Masanao [Hokkaido University Graduate School of Medicine, Department of Cardiovascular Medicine, Sapporo (Japan); Manabe, Osamu; Tomiyama, Yuuki; Tamaki, Nagara [Hokkaido University Graduate School of Medicine, Department of Nuclear Medicine, Sapporo (Japan); Sasaki, Tsukasa [Hokkaido University Hospital, Department of Radiology, Sapporo (Japan); Katoh, Chietsugu [Hokkaido University Faculty of Health Sciences, Sapporo (Japan); Shirato, Hiroki [Hokkaido University Graduate School of Medicine, Department of Radiation Medicine, Sapporo (Japan)

    2014-07-15

    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 {sup 15}O-H{sub 2}O positron-emission tomography (PET) and assesses the CFRs of coronary artery disease (CAD) patients. Thirty-two subjects underwent both dynamic CT perfusion (CTP) and PET perfusion imaging at rest and during pharmacological stress. In 12 normal subjects (pilot group), the calculation method for MBF and CFR was established. In the other 13 normal subjects (validation group), MBF and CFR obtained by dynamic CTP and PET were compared. Finally, the CFRs obtained by dynamic CTP and PET were compared between the validation group and CAD patients (n = 7). Correlation between MBF of MDCT and PET was strong (r = 0.95, P < 0.0001). CFR showed good correlation between dynamic CTP and PET (r = 0.67, P = 0.0126). CFR{sub CT} in the CAD group (2.3 ± 0.8) was significantly lower than that in the validation group (5.2 ± 1.8) (P = 0.0011). We established a method for measuring MBF and CFR with the relatively low-dose dynamic MDCT. Lower CFR was well demonstrated in CAD patients by dynamic CTP. (orig.)

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

    International Nuclear Information System (INIS)

    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.)

  4. Rowing Physiology.

    Science.gov (United States)

    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…

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

    International Nuclear Information System (INIS)

    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

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

    International Nuclear Information System (INIS)

    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.)

  7. Coronary artery anomalies: Assessment with electrocardiography-gate multidetector-row CT at a single center in Korea

    Energy Technology Data Exchange (ETDEWEB)

    Yi, Bo Ram; Sun, Joo Sung; Yang, Hyoung Mo; Kang, Doo Kyoung [Ajou University School of Medicine, Suwon (Korea, Republic of)

    2015-04-15

    To determine the prevalence of coronary anomalies using coronary computed tomography angiography (CCTA) and to evaluate the relationship between coronary artery anomalies and chest pain. A total of 12676 patients underwent CCTA scans at our institution between December 2006 and April 2013 using a 64-slice CT and a 128-slice dual-source CT. We determined the prevalence of coronary artery anomalies according to the classification system proposed by Greenberg. The presence or absence of chest pain with each coronary artery anomaly was also evaluated. Coronary anomalies were found in 176 patients (1.39%) at our institute. Anomalies of origination, course, and termination were detected in 118 (0.93%), 28 (0.22%), and 30 (0.24%) patients, respectively. After the exclusion of 32 patients with combined heart disease, typical (n = 16; 11.1%) or atypical (n = 28; 19.4%) chest pain was present in 44 (30.6%) of the 144 patients at the time of diagnosis. The prevalence of coronary artery anomalies was 1.39% at our hospital. After the exclusion of patients with combined heart disease, 11.1% had typical chest pain at the time of diagnosis.

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

    International Nuclear Information System (INIS)

    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.

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

    International Nuclear Information System (INIS)

    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.)

  10. 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

    Energy Technology Data Exchange (ETDEWEB)

    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

  11. 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

    International Nuclear Information System (INIS)

    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

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

    International Nuclear Information System (INIS)

    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. 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

    OpenAIRE

    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 ...

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

    Energy Technology Data Exchange (ETDEWEB)

    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.)

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

    International Nuclear Information System (INIS)

    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

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

    International Nuclear Information System (INIS)

    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)

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

    Energy Technology Data Exchange (ETDEWEB)

    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

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

    Science.gov (United States)

    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

  19. 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

    International Nuclear Information System (INIS)

    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.)

  20. 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

    Energy Technology Data Exchange (ETDEWEB)

    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.)

  1. 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

    International Nuclear Information System (INIS)

    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)

  2. 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

    Energy Technology Data Exchange (ETDEWEB)

    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)

  3. 320排 CTA 诊断大脑后动脉成窗变异%320-detector row CT angiography in diagnosis of the posterior cerebral artery fenestration

    Institute of Scientific and Technical Information of China (English)

    张力; 于淑靖

    2015-01-01

    目的:探讨大脑后动脉成窗变异的C T血管成像(CTA)特征,提高对该血管变异的认识。方法2011年11月~2013年12月本院共有7326例患者行头颈联合320排 CTA 检查,其中8例确诊为大脑后动脉成窗变异。回顾性分析大脑后动脉成窗的部位、形态等 CTA 特征及其合并症。结果①8例患者中共有8个大脑后动脉成窗,P1段成窗7个,P1、P2段移行部联合同侧后交通动脉成窗1个;②其中1例合并基底动脉成窗,1例伴一侧大脑前动脉 A1段缺如;③2个成窗变异的“窗”径微小(<2mm),呈裂隙状。6个“窗”径较大(>2mm ,最大径约12mm),呈凸透镜样。8例患者均未发现颅内动脉瘤。结论大脑后动脉成窗变异是一种罕见的血管畸形,320排 CTA 能快速、直观、准确的判断大脑后动脉成窗变异及其合并症。%Objective To analyze the CT angiography (CTA) features of the fenestrations variation of posterior cerebral artery ,and to improve diagnosis .Methods The imaging data of 7326 patients performed 320‐detector row CTA of the cranio cervical arteries in our hospital between November 2011 and December 2013 were evaluated retrospectively ,and 8 of them were diagnosed as the fenestration variation of posterior cerebral arteries .The location ,morphological characteristics of the fenestration of posterior cerebral artery and its coexisting abnormalities were analyzed .Results ① 8 fenestrations of posterior cerebral arteries in 8 patients were found .7 fenestrations were located at the P1 segments .One fenestration was located at the junctional zone between P1 and P2 segment ,and linked with the ipsilateral posterior communicating ar‐tery ; ② One case associated with fenestration of the basilar artery ,one case associated with absence of the A 1 segment of the anterior cerebral artery ;③ Two small fenestrations (less than 2 mm) presented slit‐shaped ,and 6 larger fenestrations

  4. 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

    Institute of Scientific and Technical Information of China (English)

    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.

  5. 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

    International Nuclear Information System (INIS)

    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)

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

    International Nuclear Information System (INIS)

    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

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

    Energy Technology Data Exchange (ETDEWEB)

    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

  8. The Value of Multi-detector row CT in Gastroenteropathy and Application of Contrast Agents%MDCT在胃肠道检查中的价值及对比剂的应用

    Institute of Scientific and Technical Information of China (English)

    鲁桂青; 陈克敏; 刘林祥

    2007-01-01

    胃肠道疾患在过去以传统的检查方法 (主要为消化道钡剂透视及纤维内窥镜)为主,随着多层螺旋CT(multi-detector row CT,MDCT)的快速发展以及各种不同腔内对比剂的研究与应用,CT对胃肠道的检查价值显著提高。

  9. Application of 320-detector row CT in postoperative evaluation of intracranial aneurysm%320排动态容积CT在颅内动脉瘤术后评价中的应用

    Institute of Scientific and Technical Information of China (English)

    孙志强; 陈信坚; 陈友三; 邹佳妮; 黄文才; 田龙海; 罗金香

    2012-01-01

    目的:探讨320排动态容积CT在颅内动脉瘤术后评价中的价值.方法:2010年5月~2011年9月97例颅内动脉瘤术后患者行320排动态容积CT-DSA检查,其中行开颅夹闭术63例,血管介入栓塞术33例,栓塞并夹闭术1例.对未减影和减影图像采用容积再现(VR)、最大密度投影(MIP)、多平面重组(MPR)方法进行后处理.结果:本组97例患者图像优良率为96%,63例夹闭术及1例栓塞并夹闭术后患者共显示瘤夹65个,CTA均清晰显示动脉瘤夹位置、形态及与载瘤血管的关系;33例介入栓塞术后患者弹簧圈20例完全减掉,13例残留少许弹簧圈,但伪影较小.共发现动脉瘤残留3例,均为夹闭术后患者.此外,CTA显示2例载瘤动脉远端血管分支稀少,2例合并烟雾病,3例发现颅内其它部位动脉瘤,1例合并脑血管畸形.结论:320排动态容积CT可清晰显示动脉瘤术后有无瘤体残留、动脉瘤夹及栓塞材料与载瘤血管的关系,可以作为术后随访的首选检查方法.%Objective:To investigate the value of 320 detector row CT in postoperative evaluation of intracranial aneu rysm. Methods: Retrospective analysis was reviewed in 97 patients after intracranial aneurysm surgery from May 2010 to September 2011 ,of which 63 cases of craniotomy clipping surgery,vascular embolization in 33 cases,thrombosis and occlu sion in 1 case. All patients underwent 320 detector row CT scan,the data were recontructed with subtraction technique and reformated with volume rendering (VR) ,maximum intensity projection (MIP) and multi planar reformation (MPR) tech nique. Results:The imaging quality of 97 patients was good in 94% of patients,including 63 cases of clipping surgery and 1 case of aneurysm clipping and embolization treatment. The 65 clips were clearly showed for the location,shape and relation ship with aneurysm parent vessel on CT reformation images. The artifacts of coil on CT images were totally eliminated in 20 of 33 cases

  10. Multi-row detectors: a significant advance towards volumetric CT; Multidetection: une veritable avancee vers l'imagerie volumique en TDM

    Energy Technology Data Exchange (ETDEWEB)

    Laissy, J.P. [Groupe Hospitalier Bichat - Claude Bernard, Service de Radiologie Viscerale, 75 - Paris (France)

    2000-08-01

    The multi row detectors is an advance in the computerized tomography evolution, and the volumetric imaging must be considered as a new perspective in medical imaging. This must not make forget that the irradiation is more important because of the thinner cuts, in spite of the efforts made by the constructors to reduce the dosimetry. (N.C.)

  11. 经胃镜胃黏膜下注射64排螺旋CT胃周淋巴结造影初探%Lymphatic Drainage from Gastric Tract:Preliminary Investigating Feasibility of Endoscopic 64-row Spiral CT Lymphography

    Institute of Scientific and Technical Information of China (English)

    朱建兵; 陈光强; 李勇; 朱江涛; 张伟; 龚建平

    2012-01-01

    目的 初步探讨胃黏膜下注射64排螺旋CT胃周淋巴结造影的应用价值.方法 征集21例志愿患者,进行胃镜下胃黏膜下造影剂注射,然后进行64排螺旋CT扫描.结果 16例患者均在完成64排螺旋CT的扫描获得相应图像.CT图像显示5例患者可见肝脏及血管旁线性致密影呈现;14例非胃癌患者仅8例发现可辨别的淋巴结影,其中2例患者发现胃周淋巴结密度增高.结论 胃镜辅助下64排螺旋CT胃周淋巴结造影作为一种潜在的术前淋巴结造影的选择具有一定优越性,但是应用于临床需要进一步的研究.%Objective To investigate feasibility of endoscopic 64-row spiral CT lymphography of the gastric tract preliminarily.Methods With institutional committee approval,a total of 2mL of undiluted iopamidol was injected into the gastric submucosa by endoscope in 21 volunteer patients,then scanning with 64-row spiral CT. Result 16 patients completed CT scan and got the imaging needed;5 patients were found the line high attenuation nearby liver and vascular;8 of the 14 patients were found lymphatic nodes identified;2 patients were found high attenuation lymphatic nodes nearby stomach.Conclusion Endoscopic 64-row spiral CT lymphography of stomach as a potentially lymphography of the stomach,still needs more investigation for clinic application.

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

    International Nuclear Information System (INIS)

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-03-15

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

  14. High-concentration contrast media in neurological multidetector-row CT applications: implications for improved patient management in neurology and neurosurgery

    Energy Technology Data Exchange (ETDEWEB)

    Schramm, Peter [University of Heidelberg Medical Center, Department of Neuroradiology, Heidelberg (Germany)

    2007-07-15

    Dynamic CT scanning after intravenous injection of iodine contrast medium (CM) was proposed in the very early days of CT. The goal was to characterize tissue by extracting information from the temporal course of enhancement. In the early 1980s, modeling algorithms were already described in the literature for the quantitative calculation of cerebral blood flow (CBF). However, cerebral applications suffered from the insufficient temporal resolution available at that time and the central nervous system was already seen primarily as an MRI domain. The renaissance of dynamic CT in neurological applications came in the middle of the 1990s with the introduction of thrombolytic therapy in acute stroke. With CT being the primary imaging modality, getting additional hemodynamic information from the same device without having to move the patient appeared attractive. Multimodal CT protocols allow a comprehensive diagnosis of the emergency stroke patient in less than 15 minutes by combining nonenhanced CT (NECT), perfusion CT (PCT) and CT angiography (CTA). Dynamic PCT can also render important information in patients with intraaxial brain tumors, allowing differentiation not only between lymphoma and glioma but also between low-grade and high-grade glioma by quantifying local cerebral blood volume (CBV) and permeability of the blood-brain barrier (BBB). Hoever, even if a shorter imaging time permits a reduction in volume of CM, adequate total iodine levels must be preserved for dynamic CT applications. Increased concentrations of iodine are therefore helpful to obtain adequate total iodine levels for imaging. (orig.)

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    International Nuclear Information System (INIS)

    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

  17. Row Row Row Your Boat%划船歌

    Institute of Scientific and Technical Information of China (English)

    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)

  18. 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

    International Nuclear Information System (INIS)

    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)

  19. 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

    Institute of Scientific and Technical Information of China (English)

    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

  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

    Energy Technology Data Exchange (ETDEWEB)

    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. 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

    International Nuclear Information System (INIS)

    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)

  2. Diagnosis and Treatment Value of 64 Row CT in Children With Secretory Otitis Media%64排CT在儿童分泌性中耳炎诊疗中的作用

    Institute of Scientific and Technical Information of China (English)

    付高尚; 徐艳霞; 韩富根

    2015-01-01

    目的:探讨64排CT在儿童分泌性中耳炎诊断、治疗过程中的意义。方法对2012年8月~2014年8月在本院治疗的76例(131耳)分泌性中耳炎患儿的临床资料进行回顾性分析。结果76例(131耳)分泌性中耳炎患儿当中,其中部分患儿3月后复查CT乳突密度影降低,避免了不必要的手术。结论64排颞骨CT检查对儿童分泌性中耳炎病情严重程度准确诊断提供重要的参考价值。%Objective To investigate the 64 slice CT in the diagnosis of children with secretory otitis media,in the course of treatment significance.Methods From August 2012 to August 2014 in our hospital(76 cases(131 ears)of secretory otitis media in children with clinical data were retrospectively analyzed.Results 76 cases(131 ears)with secretory otitis media in children,including review of CT significantly decreased the mastoid density in march part of the children,to avoid unnecessary operation.Conclusion The diagnostic accuracy of 64 row CT scanning of temporal bone of children with secretory otitis media disease severity and provides an important reference value.

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

    International Nuclear Information System (INIS)

    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

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

    International Nuclear Information System (INIS)

    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.)

  5. 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

    Institute of Scientific and Technical Information of China (English)

    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

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

    Directory of Open Access Journals (Sweden)

    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.

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

    OpenAIRE

    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...

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

    International Nuclear Information System (INIS)

    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).

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

    Energy Technology Data Exchange (ETDEWEB)

    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.)

  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

    Institute of Scientific and Technical Information of China (English)

    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. CT动脉造影定位脊髓跟大动脉的应用研究%Application of row CT angiography on locating the artery of Adamkiewicz

    Institute of Scientific and Technical Information of China (English)

    贾英斌; 文慧岚; 苏永辉; 潘海燕; 刘汉伟

    2011-01-01

    目的 利用CT主动脉造影,分析、定位脊髓跟大动脉(the artery of Adamkiewicz,AKA).方法 对拟诊主动脉疾病的92例患者行螺旋CT主动脉造影,对扫描图片进行横断面、冠状面多维重建,并显示最大强度投影,根据AKA的连续性及“发卡”样特征对其定位分析.结果 51例(55.4%)患者共显影54支AKA(3例显示双支AKA,5.9%),其中87.0%位于T8至T11节段,77.8%发自主动脉左侧.累及胸主动脉的夹层和动脉瘤的AKA检出率分别为44.7%和37.5%,未累及胸主动脉的腹主动脉瘤和主动脉仅呈现粥样斑块者的AKA检出率是67.6%和66.7%,两者差异具有统计学意义(P<0.05).结论 AKA源自胸腰段的具体位置存在很大变异,螺旋CT主动脉造影为定位AKA提供了可依赖的手段.%Objective To locate and analyze the artery of Adamkiewicz using row CT angiography.Methods 92 patients with snspicion for aortic lesions underwent row CT angiography.Transverse sections,coronal multiplanar reformations (MPR) and maximum intensity projections(MIP) were generated and displayed.AKA was identified according to its continuity of the intercostal or lumbar artery and "hairpin"configuration.Results 54 A K A were detected in 51 of 92 patients(55.4%),3 patients (5.9%) had a second AKA.87.0% of AKA originated at the T8 through T(1 1) level and 77.8% occurred on the left side of aorta.The detected ratio of AKA in patients with thoracic aorta lesions (aortic dissection or thoracic aortic aneurysms) were 44.7%,37.5% respectively.However,the ratio in patients without thoracic aorta lesions (abdominal aortic aneurysm or atherosclerotic plaques) was 67.6% or 66.7%.There was statistically significant difference hetween the two kinds of lesions(P < 0.05).Conclusions The accurate level of AKA has more variations.CT angiography scan is a reliable non-invasive technique to locate AKA.

  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

    Energy Technology Data Exchange (ETDEWEB)

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

    Science.gov (United States)

    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

  14. 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

    Institute of Scientific and Technical Information of China (English)

    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

  15. The Incidence and Anatomy of Accessory Pudendal Arteries as Depicted on Multidetector-Row CT Angiography: Clinical Implications of Preoperative Evaluation for Laparoscopic and Robot-Assisted Radical Prostatectomy

    International Nuclear Information System (INIS)

    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

  16. Rowing with FES

    OpenAIRE

    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...

  17. 64排螺旋CT血管成像在脑AVM术后评价的应用研究%Postoperative Evaluation of Brain AVM with the 64-row Spiral CT Augiography

    Institute of Scientific and Technical Information of China (English)

    关国信; 名强; 程彦; 张永生; 王岩; 翁志蓬; 刘海平; 黄正旺; 郑晓昀; 李强

    2015-01-01

    目的:探讨64排螺旋CT血管成像(CTA)在脑动静脉畸形(AVM)术后评价的应用价值。方法:39例脑AVM患者,术前均完善CTA检查,术后1周行CTA随访,术后1个月行DSA随访,由放射科医师与神经外科医师对术后CTA进行共同阅片,并与术前CTA及术后DSA进行对比分析。结果:CTA显示39例脑AVM均为单发,均行开颅切除,4例使用了动脉夹辅助;CTA对脑AVM术后残留评价的敏感度和准确度分别为100%、97.4%,DSA对脑AVM术后残留评价的敏感度和准确度均为100%,两者的诊断敏感度和准确度比较,差异无统计学意义(P>0.05)。结论:应用CTA与DSA对脑AVM术后评价,CTA更为安全、方便,可作为首选方法。%Objective: To study the value of 64-row spiral CT Augiography (CTA) in postoperative of brain AVM. Method:39 patients with brain AVM were completed the CTA examination of preoperative, and they all completed the CTA examination of postoperative review after 1 week, complete the DSA examination of postoperative review after 1 month, and to compare the images together by radiologists and neurosurgeons.Result:39 patients with brain AVM were single, and removal of by craniotomy, 4 cases used the artery clamp in surgery; The postoperative residual of brain AVM that the sensitivity and accuracy of CTA was 100% and 97.4% respectively, and the sensitivity and accuracy of DSA was both 100%. There was no significant difference in the diagnostic sensitivity and accuracy (P>0.05). Conclusion: For application of cerebral AVM postoperative evaluation results of CTA and DSA, the CTA is more safe, convenient, can be used as the preferred method.

  18. Hereditary haemorrhagic telangiectasia: study of hepatic vascular alterations with multi-detector row helical CT and reconstruction programs; Telangiectasia emorragica ereditaria: TC multidetettore multifasica e programmi di ricostruzione nello studio delle alterazioni vascolari epatiche

    Energy Technology Data Exchange (ETDEWEB)

    Memeo, Maurizio; Stabile Ianora, Amato Antonio; Scaldapane, Arnaldo; Rotondo, Antonio; Angelelli, Giuseppe [Policlinico Universitario, Bari (Italy). DiMIMP Sezione di Diagnostica per Immagini; Suppressa, Patrizia; Cirulli, Anna; Sabba' , Carlo [Policlinico Universitario, Bari (Italy). Centro Interdipartimentale per lo studio dell' HHT

    2005-02-01

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

  19. Rowing with FES

    Directory of Open Access Journals (Sweden)

    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.

  20. Biomechanics of Rowing

    Science.gov (United States)

    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.

  1. Application of Whole-brain Perfusion CT with 320-detector Row CT System in Staging of Cerebral Ischemic Penumbra%320排动态容积CT全脑灌注成像在脑梗死缺血半暗带分期中的应用

    Institute of Scientific and Technical Information of China (English)

    向永华; 王波; 金科; 杨伟; 汪春红

    2012-01-01

    Purpose To investigate the feasibility of staging cerebral ischemic penumbra using 320-detector row CT whole-brain perfusion imaging. Materials and Methods The values of cerebral blood volume (CBV), cerebral blood flow (CBF), mean transit time (MTT) and time to peak (TTP) were measured in infarct core area, ischemic penumbra, and mirror area in 18 cases with ischemic penumbra. The staging of the ischemic penumbra was made according to the criteria of pre-infarction period staging. Results In 18 cases with ischemic penumbra, MTT and TTP were delayed; CBF was decreased; CBV was slightly decreased, normal or slightly increased. Compared with infarct core area, CBV and CBF were increased, MTT was delayed and TTP was shortened in ischemic penumbra (P 0.05). In 18 cases, three cases were in stage I 2, nine cases in stage Ⅱ1, six cases in stage Ⅱ2. Conclusion Application of whole-brain perfusion CT with 320-detector row CT system can identify the area of cerebral lesions and the existence of ischemic penumbra.%目的 应用320排动态容积CT全脑灌注成像探讨脑梗死缺血半暗带分期的可行性.资料与方法 测量18例存在缺血半暗带脑梗死患者的梗死核心区、缺血半暗带区及其镜像对侧脑血容量(CBV)、脑血流量(CBF)、平均通过时间(MTT)及达峰时间(TTP),按脑梗死前期分期标准对缺血半暗带进行分期.结果 18例缺血半暗带区表现为MTT、TTP延长,CBF降低,CBV轻度升高、正常或轻度降低.与梗死核心区比较,缺血半暗带区CBV、CBF升高,MTT延长,TTP缩短(P<0.05);与健侧对应区比较,CBF降低,MTT及TTP延长(P<0.05),而CBV无显著差异(P>0.05).缺血半暗带分期:Ⅰ2期3例,Ⅱ1期9例,Ⅱ2期6例.结论 应用320排动态容积CT全脑灌注成像可明确脑梗死患者的病变部位、范围以及有无缺血半暗带存在,并可对缺血半暗带进行分期.

  2. Application and its clinical significance of 16 row spiral CT enhanced scanning in the diagnosis of pulmonary embolism%16排螺旋CT增强扫描在肺动脉栓塞诊断中的应用及其临床意义

    Institute of Scientific and Technical Information of China (English)

    杨震杰

    2015-01-01

    Objective:To explore the application and its clinical significance of 16 row spiral CT enhanced scanning in the diagnosis of pulmonary embolism.Methods:28 patients with pulmonary embolism were selected from May 2011 to April 2014.They were diagnosed using 16 slice spiral CT enhanced scan.We evaluated the clinical application.Results:By 16 slice spiral CT scan, we could find out the exact location and morphology of pulmonary embolism.Conclusion:The 16 row spiral CT scan can clearly diagnose pulmonary embolism,and timely provide the advantageous basis for treatment,and it has important clinical significance.%目的:探讨16排螺旋CT增强扫描在肺动脉栓塞诊断中的应用及其临床意义.方法:2011年5月-2014年4月收治肺动脉栓塞患者28例,采用16排螺旋CT增强扫描后进行肺动脉栓塞的诊断,并对其在临床上的应用进行评价.结果:经过16排螺旋CT扫描能准确找出肺动脉栓塞发生的部位和形态.结论:采用16排螺旋CT增强扫描能明确诊断肺动脉栓塞的情况,并为治疗提供及时有利的依据,具有重要的临床意义.

  3. Evaluation of retrospectively ECG-gated 4-row multidetector CT in patients planned for minimal invasive coronary artery bypass grafting; Die EKG-getriggerte 4-Zeilen-Spiral-CT des Herzens in der praeoperativen Bildgebung vor minimalinvasiver koronarer Bypass-Operation

    Energy Technology Data Exchange (ETDEWEB)

    Begemann, P.G.C.; Ittrich, H.; Koops, A.; Adam, G.; Weber, C. [Klinik und Poliklinik fuer Diagnostische und Interventionelle Radiologie, Radiologisches Zentrum, Universitaetsklinikum, Hamburg (Germany); Arnold, M.; Detter, C.; Boehm, D.H.; Reichenspurner, H. [Universitaetsklinikum Hamburg-Eppendorf, Herzzentrum, Herz und Gefaesschirurgie, Hamburg (Germany)

    2005-08-01

    Purpose: Minimal invasive direct coronary artery bypass grafting (MIDCAB) or off-pump coronary artery bypass grafting (OPCAB) on the beating heart with full or mini-sternotomy are becoming more common in coronary bypass surgery of the left anterior descending (LAD). In the decision, which surgical approach (MIDCAB, OPCAB or conventional surgery with cardiopulmonary bypass) will be best used, knowledge of the anatomical field is of major importance. The aim of the study was to evaluate retrospective ECG-gated 4-row multidetector CT (MDCT) in patients planned for MIDCAB as additional imaging to coronary angiography. Material and methods: The study included 25 consecutive patients. MSCT was performed as unenhanced (collimation 4 x 2.5 mm) and contrast-enhanced examination (140-170 ml, 300 mg Iodine/ml, collimation 4 x 1 mm). The evaluation included presence of LAD calcifications, distance of LAD and left internal mammarian artery (LIMA), coursek of LAD and LIMA, the presence or absence of bridging through myocardium or epicardial fat and the presence of pleural fibrosis. The MDCT results were correlated with intra-operative findings. Results: All MDCTs could be assessed with reference to the demands. In 20/25 operations, MDCT had direct influence as to the selection of the surgical approach (11 MIDCAB, 7 OPCAB with mini-sternotomy and 5 with full sternotomy, 2 conventional surgeries). The distance of LAD and LIMA varied from 0.9 to 4.5 cm in MDCT. As to calcifications, 3/25 correlated patients had calcifications and 10 patients had no calcifications in the middle LAD. Seven patients had intraoperative fibrosis of the vessel wall without calcification of the middle LAD, which could not be detected with MDCT. Another 5 patients had single calcified plaques in the middle LAD, 4 of these had a fibrosis of the vessel and 1 had a normal vessel at surgery. In these cases, the anastomosis was done between the calcified plaques. No myocardial bridging was detected by MDCT and

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

    International Nuclear Information System (INIS)

    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

  5. 64 row CT cerebral perfusion applied research of brain ischemia%64排CT脑灌注对脑组织缺血程度的应用研究

    Institute of Scientific and Technical Information of China (English)

    刘贯清; 肖新兰; 李晓; 黄小宁; 李五根

    2015-01-01

    Objective Application of 64 row CT cerebral perfusion brain tissue ischemia. Methods 40 cases of clinical diag-nosis of acute cerebral infarction,patients with unilateral lobe brain perfusion CT perfusion showed abnormal,in combination with MRI to determine infarct,according to the cerebral blood flow group,group A (low perfusion group) and group B (infarction group), respectively,evaluation of two groups of cerebral blood flow perfusion parameters and comparison analysis. Results Of 40 cases, 18 cases of group A,CTP anomaly low perfusion of figure is determined by MTT extend approximately 1.28 (R),decreased CBF mild,CBV basic no change Or moderately reduced,only determined by MTT extension was statistically significant (P<0.01);Infarc-tion group,22 cases of group B,infarction area surrounding IP abnormal perfusion is determined by MTT extend approximately 1. 48(R),CBF significantly decreased approximately 0.45(R),CBV moderately reduced,which extended determined by MTT was sta-tistically significant (P<0.001),decrease CBF was statistically significant (P<0.01);Infarction district performance is determined by MTT extend approximately 1.64(R),CBF significantly decreased approximately 0.36(R),significantly lower CBV (approximately 0. 37)R. Which determined by MTT extension was statistically significant (P<0.001),CBF decline was statistically significant(P<0.01). Conclusion Brain tissue hypoperfusion area with the infarction in central and peripheral IP area the perfusion parameters have significant differences,according to the variation of perfusion parameters characteristics can make the image on the degree of is-chemic infarction assessment,when rCBF<0.5,suggesting infarction risk is extremely high,the clinical guidance for early interven-tion treatment.%目的:探讨应用64排CT脑灌注评价脑组织缺血程度。方法40例临床诊断急性脑梗塞,CT灌注显示单侧脑叶灌注异常患者,结合MRI判断梗塞,根据脑血流量进行分组,A

  6. Application of CT angiography of carotid atherosclerotic plaque in patients with ischemic cerebral stroke%颈动脉斑块 CT 血管成像在缺血性脑卒中患者中的应用

    Institute of Scientific and Technical Information of China (English)

    郑玉飞; 朱丽丽; 王卓群; 徐辉

    2014-01-01

    Objective To analysis 64-slice CT angiography imaging features of carotid atherosclerotic plaque and explore the relationship between different types of carotid atherosclerotic plaque and ischemic cerebral stroke. Methods The clinical data of 60 cases of ischemic cerebral stroke were retrospectively analyzed, all the cases were underwent 64-detector row CT angiography, and the distribution, character and morphological characteristics of carotid atherosclerotic plaque, and morphological characteristics and the extent of stenosis were observed with the original ax -ial image,volume rendering ( VR) and curved planar reconstruction ( CPR). Results In the 60 cases of ischemic cer-ebral stroke,58 cases with carotid atherosclerotic plaque were found. A total of 228 plaques were detected, including 43 non-calcified plaque, 125 calcified plaque and 60 mixed plaque. In 60 cases, 170 mild stenosis, 20 moderate ste-nosis, 12 severe stenosis and 1 occlusion were found, no significant stenosis were found in 20 sites. Five calcified plaques were found in intracranial segment of internal carotid artery, and CT can′t evaluate the severity of the steno-sis. There was significantly statistical difference in unstable plaque between non-lacunar infarct and lacunar infarct (P<0. 05 ). Conclusion 64-detector row CT angiography of carotid atherosclerotic plaques can accurately detect the dis -tribution, character and morphological characteristics of carotid atherosclerotic plaque and the degree of stenosis of ca -rotid artery,it is a valuable method in prevention, treatment, and prognosis judgement of ischemic cerebral stroke.%目的:通过分析颈动脉斑块64排CT血管成像特点,探讨不同类型颈动脉斑块与缺血性脑卒中的相关性。方法回顾分析60例缺血性脑卒中患者头颈部64排CT血管成像资料,轴位原始图像结合容积再现( VR)及曲面重建( CPR),观察颈动脉斑块的分布、性质及形态特征,测量

  7. Rowing to Barbados

    OpenAIRE

    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.

  8. Rowing competitions and perspective

    Science.gov (United States)

    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.

  9. Non-invasiv, Multi Detector Row (MDR) based Computational Fluid Dynamics (CFD) analysis of hemodynamics in infrarenal Abdominal Aortic Aneurysm (AAA) before and after endovascular repair; Blutflusssimulation mittels Computational-Fluid-Dynamics an aus CT-Daten rekonstruierten Aortenaneurysmata vor und nach Stent-Graft Implantation

    Energy Technology Data Exchange (ETDEWEB)

    Juchems, M.S.; Pless, D.; Fleiter, T.R.; Gabelmann, A.; Brambs, H.J.; Aschpoff, A J. [Ulm Univ. (Germany). Abt. fuer diagnostische Radiologie; Liewald, F. [Ulm Univ. (Germany). Abt. fuer Thorax-und Gefaesschirurgie

    2004-01-01

    Purpose: Simulation, description and analysis of dynamic pressure in infrarenal abdominal aortic aneurysms (AAA) before and after endovascular repair. Materials and Methods: During March 1996 and May 2001, 13 patients with AAA underwent endovascular treatment. The MDR-CT scans of these patients were used for the non-invasive analysis of the hemodynamics in the aorta with CFD software before and after endovascular repair. One pre-interventional and three post-interventional CT scans were analyzed for each patient. Results: Compared to the pre-interventional simulation, endovascular treatment led to an average dynamic pressure decrease of 1057 Pa in 10 of 13 patients. During the subsequent course, the median of the dynamic pressure decreased in 8 of 13 patients. Vulnerable regions initially identified as high-pressure regions, like the docking area or the second stent limb, adapted to the pressure in the surrounding tissue in the course of time. (orig.) [German] Ziel: Simulation, Beschreibung und Entwicklung dynamischer Druckverhaeltnisse auf die Aorten- bzw. Stentgraftwand im zeitlichen Verlauf vor und nach stentgestuetzter Ausschaltung infrarenaler Bauchaortenaneurysmata. Patienten und Methode: Zwischen Maerz 1996 und Mai 2001 wurden 13 Patienten mit einem infrarenalen Bauchaortenaneurysma einer transfemoralen Stent-Graft-Implantation unterzogen. Basierend auf Multi Detector Row (MDR) -CT Datensaetzen dieser 13 Patienten wurde mithilfe einer ''Computational Fluid Dynamics'' (CFD) Software eine Blutflusssimulation der abdominellen Aorta vor und nach Stentimplantation durchgefuehrt. Von jedem Patienten wurden Simulationen von einer prae- und drei postoperativen Follow-up CT-Serien erstellt. Ergebnisse: Die Stentimplantation fuehrte bei 10/13 Patienten zu einer Senkung des dynamischen Spitzendrucks um durchschnittlich 1057 Pa von der prae- zur postoperativen Untersuchung. Im weiteren Verlauf sank auch der Median des dynamischen Druckes bei 8

  10. Training Rowing with Virtual Environments

    OpenAIRE

    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.

  11. 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

    Institute of Scientific and Technical Information of China (English)

    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.

  12. Clinical application with 16-row spiral CT in diagnosis of esophageal hiatal hernia%16层螺旋CT在食管裂孔疝诊断中的应用

    Institute of Scientific and Technical Information of China (English)

    黄婷

    2013-01-01

    目的:探讨16层螺旋CT在食管裂孔疝诊断中的应用价值.方法:回顾25例经胃镜、手术或上消化道造影证实的食管裂孔疝患者的16层螺旋CT资料并加以分析.结果:16层螺旋CT可以清晰显示食管裂孔疝的疝囊大小、部位、形态、密度、膈肌裂孔情况及病变与邻近结构的关系.结论:16层螺旋CT通过薄层断面和多平面重建技术(MPR)可以多角度显示疝囊及内容物,可为肿瘤性病变及其他不明原因膈肌膨隆的鉴别诊断提供有价值的诊断信息.%Objective: To investigate diagnostic value of 16 slice spiral CT in esophageal hiatal hernia. Methods: We reviewed 25 cases by gastroscope, operation or upper gastrointestinal radiography confirmed esophageal hiatal hernia in patients with 16 slice spiral CT data, and analyzed. Results: Image of 16 slice spiral CT could clearly show the esophageal hiatal hernia hernia sac size, position, shape, density, the diaphragmatic hiatus and pathological relationship with adjacent structures. Conclusion: 16 slice spiral CT through thin section and multiplanar reconstruction (MPR) can be multi-angle display hernia sac and contents, especially in the display of the diaphragmatic hiatus of broadening and lesions and their relation to the adjacent tissues have irreplaceable role.At the same time and neoplastic lesions and other unexplained diaphragm bulge in the differential diagnosis of provide valuable diagnostic information.

  13. 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

    International Nuclear Information System (INIS)

    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.)

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

    Directory of Open Access Journals (Sweden)

    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.

  15. Training Rowing with Virtual Environments

    Directory of Open Access Journals (Sweden)

    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.

  16. Application of 64-row spiral CT in the evaluation of invasion of trachea,bronchi,and hilar vessels in central type of lung cancer%MSCT在判断中央型肺癌对气管、支气管及肺门血管侵犯中的价值

    Institute of Scientific and Technical Information of China (English)

    黄宝泉; 郑悦; 张庆武; 曾向廷; 林惠如

    2013-01-01

    Objective: To investigate the value of 64 row spiral computed tomography (MSCT) in the diagnosis of tra chea,bronchi and hilar vascular invasion by central type of lung cancer (CLC). Methods:Seventy five cases of CLC under went MSCT examination with post processing techniques including multiplanar reformation (MPR) ,curved planar reforma tion (CPR) ,volume rendering (VR) ,minimum intensity projection (MinIP) ,maximum intensity projection (MIP) and CT virtual endoscopy (CTVE). The relationship of trachea,bronchi,pulmonary hilar vessels with the neoplasm was studied. Results :Invasion of trachea and bronchi by CLC included extraluminal compression type (38 cases,50. 7%) ,which was showed on CT as compression and/or invasion of bronchi led to uneven stenosis;infiltration of bronchial wall(28 cases,37.3%)12. 0%) showed as protruding of neoplasm into the lumen which led to eccentric stenosis of trachea/bronchi. Altogether 117 hilar vessels were invaded by CLC,of which,95 (81. 2%) could be assessed on CT,showing obvious narrowing or oblitera tion; blood vessels encircled by tumor (n = 12,10. 3%) , and tumor thrombosis (n=10,8. 5%). Conclusion: The anatomic features of trachea,bronchi,and hilar vessels and their spacial relationship with CLC could be accurately assessed on 64 row spiral CT with post processing techniques, which provides significant information in judging whether there are trachea, bronchi, and hilar vessel invasion by CLC.%目的:探讨64排螺旋CT及后处理技术在判断中央型肺癌(CLC)对气管、支气管及肺门血管侵犯中的价值.方法:75例经纤支镜或病理确诊的CLC患者行64排螺旋CT扫描,运用多平面重组、曲面重组、容积再现、最大密度投影、CT仿真内窥镜等后处理技术观察肿瘤与气管、支气管及肺门血管的关系.结果:肿瘤对气管、支气管的侵犯表现为管外压迫型38例(50.7%),CT表现为肿瘤压迫并侵犯支气管,管腔内呈不均匀狭窄;管壁浸润型(28

  17. 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

    Institute of Scientific and Technical Information of China (English)

    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.

  18. 320排CT灌注成像在头面部皮瓣移植前血供评价方面的应用价值%Value of 320-detector row perfusion CT in the pre-transplantation evaluation of head and facial skin flaps

    Institute of Scientific and Technical Information of China (English)

    许开元; 肖丹丹; 王彬; 王春梅; 杨思奋; 张雪林; 高芳琴

    2014-01-01

    目的:应用320排动态容积灌注CT扫描技术分析其在评估头颈面部皮瓣血供中的价值。方法研究对象为2011年8月~2013年4月间行全脑灌注的患者,共576例患者行320排CT全脑灌注CT检查。所有纳入研究的患者均无颈外动脉系统异常,因其他原因行头颅灌注CT检查的患者。获得的容积灌注数据通过体部灌注软件进行分析,并测量扫描区域内不同皮瓣的血流量值。皮瓣的供血动脉也可同时获得。获得的容积扫描数据经后处理后得到伪彩图,可进行兴趣区灌注血流(BF)值测量,测量时尽可能避开血管。动态容积扫描技术同时可获得扫描区域的血管信息,为穿支皮瓣移植提供基本信息。结果测量所有患者头面部皮瓣的BF值,包括额部、眼睑、鼻背部、颊部、颞部、枕部、颈部皮瓣,BF值分别为(127±7.7)、(268.0±31.1)、(229.0±50.9)、(67.8±9.5)、(140.3±5.5)、(163.8±15.5)、(123.5±12.5)ml/min。不同区域的皮瓣血供差别较大,眼睑与鼻背部皮瓣BF值较高,颊部BF值较低。检查同时也可获得不同期相皮瓣供血动静脉的图像,显示率为100%。结论320排动态容积灌注扫描技术可为接受头面部自体皮瓣移植患者提供有效的术前血供评估。灌注与解剖图像的融合有助于皮瓣术前设计。%Objective To investigate the value of 320-detector row perfusion CT in the pre-transplantation evaluation of blood supply of head and facial flaps.Methods Whole-head perfusion CT was performed on 576 patients with normal external carotid arteries using a 320-detector row CT system from August 2011 to April 2013.The number of visible feeding arteries and draining veins in the skin flaps on CTA was recorded.Pseudo color map was generated from the volume data using the body perfusion software.Blood flow of each skin flap within the scan region was measured.Results The blood flow

  19. CT urography

    Energy Technology Data Exchange (ETDEWEB)

    Korobkin, M. [Dept. of Radiology, Univ. of Michigan, Ann Arbor, MI (United States)

    2005-11-15

    With the advent of multidetector row CT scanners, evaluation of the urothelium of the entire urinary tract with high-resolution thin sections during a single breath-hold has become a reality. Multidetector CT urography (MDCTU) is a single examination that allows evaluation of potential urinary tract calculi, renal parenchymal masses, and both benign and malignant urothelial lesions. Initial results with this new technique are encouraging. Current investigations of MDCTU focus on methods to improve opacification and distension of the upper urinary tract - the collecting systems, pelvis, and ureters. The role of abdominal compression, infusion of saline and/or furosemide, and optimal time delay of excretory phase imaging is being explored. Upper tract urothelial malignancies, including small lesions less the 5 mmin diameter, can be detected with high sensitivity. Methods to reduce radiation exposure are being explored, including split-bolus contrast injection techniques that combine nephrographic and excretory phases into a single phase. It is likely that in the near future, radiological evaluation of significant unexplained hematuria or of known or prior urothelial malignancy will consist of a single examination - MDCTU. (orig.)

  20. 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

    Institute of Scientific and Technical Information of China (English)

    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.

  1. Beyond Rows of Little Men

    DEFF Research Database (Denmark)

    Pedersen, Pia

    2016-01-01

    information into visual arguments based on pictograms. While the philosophical aspects of the role of the transformer have successfully inspired the model of the modern information designer, many aspects of the transformation process remain elusive for today’s designers, misunderstood and imitated as ‘rows...

  2. Slide-based ergometer rowing

    DEFF Research Database (Denmark)

    Vinther, Anders; Alkjær, T; Kanstrup, I-L;

    2012-01-01

    Force production profile and neuromuscular activity during slide-based and stationary ergometer rowing at standardized submaximal power output were compared in 14 male and 8 female National Team rowers. Surface electromyography (EMG) was obtained in selected thoracic and leg muscles along...

  3. Rowing faster by surface treatment

    NARCIS (Netherlands)

    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

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

    Science.gov (United States)

    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

  5. 肝癌患者活体肝移植术后并发症的MDCT和MRI评价%Postoperative Complications after Living Donor Liver Transplantation for Patients with Hepatocellular Carcinoma:Evaluation by Multi-Detector Row Spiral CT and Magnetic Resonance Imaging

    Institute of Scientific and Technical Information of China (English)

    陈光文; 刘曦娇; 宋彬; 黄子星

    2011-01-01

    Objective To investigate the radiological appearances of postoperative complications after living donor liver transplantation for patients with hepatocellular carcinoma under multi-detector row spiral computed tomography (MDCT) and magnetic resonance imaging (MRI) examination. Methods Thirty-nine imaging data in 20 patients with hepatocellular carcinoma after living donor liver transplantation from January 2008 to June 2010 in the West China Hospital were included and analyzed by two radiologists respectively. The relations between the types of complications and radiological appearances were especially recorded. Results All the cases experienced complications to different extent. Common surgical complications occured in 20 cases, including pertitoneal fluid collection (14 cases), pneumoperitoneum (2 cases), swelling of peritoneum, omentum, and mesentery (1 case), abdominal wall swelling (2 cases), pleural effusion (9 cases), and pericardial fluid collection (2 cases). Hepatic vascular complications involved hepatic artery in 3 cases, portal vein in 5 cases. Biliary complications presented in 7 cases, including anastomotic stenosis of biliary duct (6 cases) and bile leak (1 case). Graft parenchymal complications included intrahepatic lymph retention (11 cases), infarction (3 cases), and infection (2 cases). Intrahepatic recurrence in 5 cases, intraperitoneal metastasis in 3 csses and pulmonary metastasis in 2 cases. Conclusion MDCT and MRI have important diagnostic values for postoperative complications after living donor liver transplantation for patients with hepatocellular carcinoma.%目的 分析肝癌患者行活体肝移植(living donor liver transplantation,LDLT)术后并发症的多层螺旋CT(multi-detector row spiral CT,MDCT)和磁共振成像(magnetic resonance imaging,MRI)表现.方法 纳入2008年1月至2010年6月期间在四川大学华西医院接受LDLT的肝癌患者20例共计39份影像资料,由两位放射科医师回顾性分析图像,观察

  6. Economic impact World Rowing Championships 2014

    NARCIS (Netherlands)

    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

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

    NARCIS (Netherlands)

    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

  8. 多排螺旋CT双动脉期增强扫描对比剂浓度对肝癌检出率的影响%Detection of Hepatocellular Carcinoma with Multi - detector Row CT by Using Double- arterial Phase Enhanced Scanning: Effect of Iodine Concentration of Contrast Material

    Institute of Scientific and Technical Information of China (English)

    周建收; 宦怡; 景建梅

    2011-01-01

    目的:通过多排螺旋CT双动脉期及门脉期增强扫描,以评估对比剂浓度对肝癌检出率的影响.方法:95例肝癌患者随机分为两组行多排螺旋CT肝脏平扫及双动脉期、门脉期增强扫描,其中一组(48例)注射碘帕醇370 mgI/ml( 1.5 ml/kg),另外一组(47例)注射碘帕醇300 mgI/ml (1.85ml/kg),均于30 s注射完毕.扫描后图像由放射科医生阅片并与病理结果进行对比,统计分析两组患者> 2cm及≤2cm的肝癌病灶的诊断敏感性.结果:95例患者中共证实有259个肝癌病灶,其中87个≤2cm,172个>2cm.对于≤2cm的病灶及所有病灶动脉早期及晚期370 mgI/ml组诊断敏感性高于300 mgI/ml组,差别有统计学意义;在门脉期两组患者的诊断敏感性无显著性差异.结论:高浓密度对比剂在动脉早期、晚期可提高肝癌的检出率,特别是对于较小的肝癌病灶(≤2cm).%Purpose: To evaluate the effect of iodine concentration of contrast material on detection of hepatocellular carcinoma (HCC) with multi - detector row CT by using double - arterial phase and portal venous phase enhanced scanning. Methods: Ninety - five patients with HCC were examined by hepatic plain CT and contrast - enhanced CT including early arterial phase(EAP), late arterial phase (LAP) and hepatic parenchymal phase (HPP) scanning prospectively. Patients were randomized into two groups to receive Iopamidol 370 mgl/ml (48 patients, 1.5 ml/kg body weight) and 300 mg I/ml (47 patients, 1.85 ml/ kg body weight) respectively with a fixed injection duration of 30 seconds. The images were interpreted by radiologists and the CT results were compared with the pathological results. The detection sensitivity for tumors of two size categories (=£ 2 cm or > 2 cm) and iodine concentration groups were calculated and analyzed.Results: A total of 259 lesions were detected with 87 less than 2 cm in size and 172 larger than 2cm in size.For EAP and LAP, the sensitivity of Iopamidol 370

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  10. 64-Row Detector CT Angiography of Aortoiliac and Lower Extremity Arteries:Effect of Using a Monitoring Scan at Knee Level on Image Quality%64层螺旋CT下肢动脉血管造影:腘动脉监测触发对图像质量的影响

    Institute of Scientific and Technical Information of China (English)

    周淑琴; 彭振鹏; 周旭辉; 严超贵; 高樱; 林少春; 李树荣

    2011-01-01

    Purpose: To evaluate the effect of using a monitoring scan at knee level on image quality for 64 - row detector CT angiography of aortoiliac and lower extremity arteries.Methods: The study was performed with approval of the institutional review board and with informed consent of the subjects.A total of 62 subjects were included in this prospective study.The monitoring trigger was sited at knee level of the popliteal artery for CT angiography.Image analysis was performed as follows: Subjective evaluation of the image quality of aorto - iliac area, femoro - popliteal district and run - off vessels with VR and MIP reconstruction respectively; Calculation of the CT value of aorto - iliac area, femoro -popliteal district and run - off vessels; and evaluation of the data by variance analysis; Evalution of the distal arterial and venous visibility.Results: The monitoring scan at the level of the popliteal artery was unavailable in 1 case.The overall quality of VR images in 33 of the 61 patients (54.1%) were categorized as excellent, in 23(37.7% ) as good, in 4(6.6% ) as fair, and in 1(1.6% ) as poor, the rate of excellent and good was 91.8%; MIP images in 41(67.2%)as excellent, in 17(27.9%)as good, for 2(3.3%)as fair, and for 1(1.6%) as poor, the rate of excellent and good was 95.1%.There was a high consistency between two observers (VR: Kappa = 0.719; MIP: Kappa = 0.678).The mean CT values measured at aorto - iliac area, femoro - popliteal district and run - off vessels were 536.42Hu ± 99.68 Hu(352.43 ~ 742.71Hu),541.72Hu ± 119.05 Hu(338.38 ~ 800.75Hu) and 421.29Hu ± 97.15 Hu(264.58 ~ 739.00Hu), respectively.There were significant differences among these three segments(F = 25.25, P = 0.00).The rate of distal arterial and venous visibility were 98.9% (1531/1549)and 22.9% (14/61), respectively.Conclusion: Using a monitoring scan at knee level was useful for 64- row detector CT angiography of aortoiliac and lower extremity arteries

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

    International Nuclear Information System (INIS)

    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

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

    Directory of Open Access Journals (Sweden)

    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.

  13. Ergometer rowing with and without slides

    DEFF Research Database (Denmark)

    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...

  14. Autoand heterosuggestion in boat rowing

    Directory of Open Access Journals (Sweden)

    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.

  15. 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

    Institute of Scientific and Technical Information of China (English)

    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

  16. 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

    Institute of Scientific and Technical Information of China (English)

    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

  17. 64层螺旋CT脑灌注成像联合CT血管造影评价颅内外血管搭桥术后疗效%Assessment of cerebral internal and external vascular bypass graft in patients with single middle cerebral artery stenosis or occlusion by combining 64-row CT cerebral perfusion with angiography

    Institute of Scientific and Technical Information of China (English)

    陈天金; 朱栓庄; 温有信; 王耀彬; 韩向东; 白莹; 于旋

    2012-01-01

    Objective To assess the curative effect of cerebral internal and external vascular bypass graft in patients with sin -gle middle cerebral artery (MCA) stenosis or occlusion by combining 64 -row CT cerebral perfusion (CTP) with angiography ( CTA ). Methods Patients with middle cerebral artery stenosis or occlusion were recruited and underwent superficial temporal artery and mid -die cerebral artery(STA -MCA) bypass graft between March 2009 and Mar 2011. CTP and CTA examinations were performed in all patients before and after operation. The cerebral perfusion parameters were analyzed quantitatively and qualitatively . The origin, travel and anastomotic stoma of bypass grafts were evaluated by reconstructed CTA images . Results 46 patients were found with severe MCA stenosis or occlusion. The time to peak (TTP) and relative mean transit time (rMTT) images before therapy displayed the existence of perfusion delay. The relative cerebral blood flow (rCBF) and relative cerebral blood volume (rCRV) images did not change significantly. The decrease of TTP and rMTT after therapy was of statistical significance ( P 0.05). In reconstructed CTA images , 82 bridge vessels were well displayed, including double bridges in 39 patients. The accuracy of CTA examination was 96.5%. All the bypass grafts were well shown and the anastomotic stomas were unobstructed. Conclusions It is feasible to evaluate the curative effects of cerebral internal and ex — ternal vascular bypass graft by combining CTP images of cerebral perfusion after therapy with CTA images of cerebral internal and exter -nal bypass grafts.%目的 探讨64层螺旋CT脑灌注成像(CT perfusion,CTP)联合CT血管造影(CT angiography,CTA)评价单侧大脑中动脉(middle cerebral artery,MCA)重度狭窄(闭塞)颅内外血管搭桥术后疗效的可行性.方法 46例拟行颅内外血管搭桥术患者,术前、后均行CTP及CTA检查.计算脑灌注参数图,对治疗前后脑灌注参数进行定量和定性对

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

    OpenAIRE

    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...

  19. Economic impact World Rowing Championships 2014

    OpenAIRE

    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...

  20. Mechanical performance of aquatic rowing and flying.

    OpenAIRE

    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...

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

    International Nuclear Information System (INIS)

    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)

  2. Is metabolic syndrome predictive of prevalence, extent, and risk of coronary artery disease beyond its components? Results from the multinational coronary CT angiography evaluation for clinical outcome: an international multicenter registry (CONFIRM.

    Directory of Open Access Journals (Sweden)

    Amir Ahmadi

    Full Text Available Although metabolic syndrome is associated with increased risk of cardiovascular disease and events, its added prognostic value beyond its components remains unknown. This study compared the prevalence, severity of coronary artery disease (CAD, and prognosis of patients with metabolic syndrome to those with individual metabolic syndrome components. The study cohort consisted of 27125 consecutive individuals who underwent ≥ 64-detector row coronary CT angiography (CCTA at 12 centers from 2003 to 2009. Metabolic syndrome was defined as per NCEP/ATP III criteria. Metabolic syndrome patients (n = 690 were matched 1:1:1 to those with 1 component (n = 690 and 2 components (n = 690 of metabolic syndrome for age, sex, smoking status, and family history of premature CAD using propensity scoring. Major adverse cardiac events (MACE were defined by a composite of myocardial infarction (MI, acute coronary syndrome, mortality and late target vessel revascularization. Patients with 1 component of metabolic syndrome manifested lower rates of obstructive 1-, 2-, and 3-vessel/left main disease compared to metabolic syndrome patients (9.4% vs 13.8%, 2.6% vs 4.5%, and 1.0% vs 2.3%, respectively; p 0.05. At 2.5 years, metabolic syndrome patients experienced a higher rate of MACE compared to patients with 1 component (4.4% vs 1.6%; p = 0.002, while no difference observed compared to individuals with 2 components (4.4% vs 3.2% p = 0.25 of metabolic syndrome. In conclusion, Metabolic syndrome patients have significantly greater prevalence, severity, and prognosis of CAD compared to patients with 1 but not 2 components of metabolic syndrome.

  3. Rasch models with exchangeable rows and columns

    DEFF Research Database (Denmark)

    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...

  4. On Row Rank Equal Column Rank

    Science.gov (United States)

    Khalili, Parviz

    2009-01-01

    We will prove a well-known theorem in Linear Algebra, that is, for any "m x n" matrix the dimension of row space and column space are the same. The proof is based on the subject of "elementary matrices" and "reduced row-echelon" form of a matrix.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-08-15

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

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

    International Nuclear Information System (INIS)

    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

  7. Memory hierarchy using row-based compression

    Energy Technology Data Exchange (ETDEWEB)

    Loh, Gabriel H.; O' Connor, James M.

    2016-10-25

    A system includes a first memory and a device coupleable to the first memory. The device includes a second memory to cache data from the first memory. The second memory includes a plurality of rows, each row including a corresponding set of compressed data blocks of non-uniform sizes and a corresponding set of tag blocks. Each tag block represents a corresponding compressed data block of the row. The device further includes decompression logic to decompress data blocks accessed from the second memory. The device further includes compression logic to compress data blocks to be stored in the second memory.

  8. Does a virtual audience influence rowing?

    OpenAIRE

    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,...

  9. Machine Learning Analysis of Binaural Rowing Sounds

    OpenAIRE

    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...

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

    International Nuclear Information System (INIS)

    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)

  11. A New Hoe Blade for Inter-Row Weeding

    DEFF Research Database (Denmark)

    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. Th...

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

    Science.gov (United States)

    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

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

    Institute of Scientific and Technical Information of China (English)

    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

  14. Optical RAM row access using WDM-enabled all-passive row/column decoders

    Science.gov (United States)

    Papaioannou, Sotirios; Alexoudi, Theoni; Kanellos, George T.; Miliou, Amalia; Pleros, Nikos

    2014-03-01

    Towards achieving a functional RAM organization that reaps the advantages offered by optical technology, a complete set of optical peripheral modules, namely the Row (RD) and Column Decoder (CD) units, is required. In this perspective, we demonstrate an all-passive 2×4 optical RAM RD with row access operation and subsequent all-passive column decoding to control the access of WDM-formatted words in optical RAM rows. The 2×4 RD exploits a WDM-formatted 2-bit-long memory WordLine address along with its complementary value, all of them encoded on four different wavelengths and broadcasted to all RAM rows. The RD relies on an all-passive wavelength-selective filtering matrix (λ-matrix) that ensures a logical `0' output only at the selected RAM row. Subsequently, the RD output of each row drives the respective SOA-MZI-based Row Access Gate (AG) to grant/block the entry of the incoming data words to the whole memory row. In case of a selected row, the data word exits the row AG and enters the respective CD that relies on an allpassive wavelength-selective Arrayed Waveguide Grating (AWG) for decoding the word bits into their individual columns. Both RD and CD procedures are carried out without requiring any active devices, assuming that the memory address and data word bits as well as their inverted values will be available in their optical form by the CPU interface. Proof-of-concept experimental verification exploiting cascaded pairs of AWGs as the λ-matrix is demonstrated at 10Gb/s, providing error-free operation with a peak power penalty lower than 0.2dB for all optical word channels.

  15. CT Scans

    Science.gov (United States)

    ... 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 ...

  16. Neutron camera employing row and column summations

    Science.gov (United States)

    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).

  17. Usefulness of 320-Row Area Detector Computed Tomography for the Diagnosis of Cystic Falx Meningioma

    Directory of Open Access Journals (Sweden)

    Sadaharu Tabuchi

    2013-07-01

    Full Text Available We present a case of cystic falx meningioma. Cystic meningioma is rare and not easy to diagnose preoperatively; it is often misdiagnosed as other tumors, including glial or metastatic tumors with cystic or necrotic changes. This study showed the potential impact of 320-row computed tomography (CT on image-based diagnostic evaluation of cystic meningioma with special attention to the novel techniques of 4-dimensional CT angiography (4D-CTA and CT whole-brain perfusion (CTP. 4D-CTA showed the arterial supply feeding the tumor and late enhancement of the tumor nodule, similar to that seen in meningioma by conventional angiography. CTP showed that the tumor had a higher cerebral blood flow and cerebral blood volume and a longer mean transit time than adjacent brain tissue. These findings were consistent with meningioma and reinforced the other imaging findings, resulting in the correct preoperative diagnosis. The new techniques available for 320-row CT can potentially be used to improve differential diagnosis and preoperative assessment of cystic tumors with nodules.

  18. Machine learning analysis of binaural rowing sounds

    DEFF Research Database (Denmark)

    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....

  19. Machine Learning Analysis of Binaural Rowing Sounds

    Directory of Open Access Journals (Sweden)

    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.

  20. Flexible frontiers for text division into rows

    Directory of Open Access Journals (Sweden)

    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.

  1. A spectral directional reflectance model of row crops

    NARCIS (Netherlands)

    Zhao, F.J.; Gu, X.F.; Verhoef, W.; Wang, Q.; Yu, T.; Liu, Q.; Huang, H.A.; Qin, W.; Chen, Liangfu; Zhao, H.

    2010-01-01

    A computationally efficient reflectance model for row planted canopies is developed in this paper through separating the contributions of incident direct and diffuse radiation scattered by row canopies. The row model allows calculating the reflectance spectrum in any given direction for the optical

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

    Directory of Open Access Journals (Sweden)

    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.

  3. Principle and applications of dual source CT

    Science.gov (United States)

    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.

  4. Compressed Multiple-Row Storage Format

    CERN Document Server

    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%.

  5. Strength and conditioning practices in rowing

    OpenAIRE

    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...

  6. SVD row or column symmetric matrix

    Institute of Scientific and Technical Information of China (English)

    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.

  7. Strength and conditioning practices in rowing

    OpenAIRE

    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...

  8. Extended abstract: Partial row projection methods

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    OpenAIRE

    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...

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2005-10-01

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

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

    International Nuclear Information System (INIS)

    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)

  12. A row-by-row off-design performance calculation method for turbines

    Science.gov (United States)

    Schobeiri, T.; Abouelkheir, M.

    1991-01-01

    The turbine component of a gas turbine engine is frequently subjected to extreme operation conditions associated with significant changes in mass flow, turbine inlet temperature, pressure and rotational speed. These off-design operation conditions significantly affect the flow deflection within the turbine stage, which consists of individual stator and rotor rows. As a result, the stage parameters representing the velocity diagram will change and affect the efficiency and performance of the stage and, thus, the turbine. A row-by-row calculation method is presented for predicting the performance behavior of turbines under extreme off-design conditions. The method is applied to a multistage turbine for which the off-design performance is calculated and compared with the measurement.

  13. CT pelvimetry

    International Nuclear Information System (INIS)

    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

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

    Institute of Scientific and Technical Information of China (English)

    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. CT scan

    Science.gov (United States)

    ... 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 ...

  16. Row charge cratering calculations. [Feasibility studies

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.)

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

    Science.gov (United States)

    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

  19. Interactive motion tracing for Rowing Training

    DEFF Research Database (Denmark)

    Dai, Zheng

    2011-01-01

    This paper studies motion tracking and team coordination for the training of rowers. The design research is drawn upon the division of contribution between the designers input and the user input in a design process. We built a training system that can record and show the action of a rower’s hand....... 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.......This paper studies motion tracking and team coordination for the training of rowers. The design research is drawn upon the division of contribution between the designers input and the user input in a design process. We built a training system that can record and show the action of a rower’s hand...... 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...

  20. Nonparallelism of cambium cells in neighboring rows

    Directory of Open Access Journals (Sweden)

    Wiesław Włoch

    2014-02-01

    Full Text Available The periclinal walls of cambial cells in neighboring lineages (rows may not be parallel when viewed in their radial aspect. This lack of longitudinal parallelism may be so extensive that in active cambium pairs of cells from neighboring rows may be in contact only along restricted segments. This means that the initial cells, rather than farming a continuous layer, may be arranged in an irregular network pattern from which some parts project inward or outward from the layer of their mutual cantacts. The longitudinal nonparallelism of cambial cells becomes more pronounced during symplasitic radial growth. Unequal periclinal divisions counteract this, and in initial cells abscission of the parts projecting from the layer of mutual contact occurs. When the cambium passes from a period of activity to a Period of rest a continuous layer of initials is reestabhshed. This involves elongation by intrusive growth of those cells previously shortened as the result of irregular periclinal divisions. The division walls in cambial cells may be warped, that is they change their orientation along the longitudinal direction perhaps even similar to an aircraft propeller. A division wall may thus be periclinal in one part of the cell and anticlinal in another.

  1. NUMERICAL MODEL APPLICATION IN ROWING SIMULATOR DESIGN

    Directory of Open Access Journals (Sweden)

    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. The Adaptive Control of FES-assisted Indoor Rowing Exercise

    OpenAIRE

    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...

  3. Characteristics of paraesophageal varices: A study with 64-row multidetector computed tomograghy portal venography

    Institute of Scientific and Technical Information of China (English)

    Li-Qin Zhao; Wen He; Guang Chen

    2008-01-01

    AIM:To identify the charactedsUcs of morphology,location and collateral circulation involved in paraesophageal varices (para-EV) of portal hypertension patients with 64-row multidetector computed tomograghy (MDCT).METHODS:Fifty-two of 501 patients with portal hypertensive cirrhosis accompanied with esophageal varices were selected for 64-row MDCT examination after the observation of para-EV.The CT protocol included unenhanced,arterial and portal phases with a slice thickness of 0.625 mm and a scanning field of 2 cm above the bifurcation to the lower edge of kidney.The CT portal venography (CTPV) was reformatted on AW4.3 workstation.The characteristics of origination,location,morphology and collateral circulation in para-EV were observed.RESULTS:Among the 52 cases of para-EV,50 showed the originations from the posterior branch of left gastric vein,while the others from the anterior branch.Fifty cases demonstrated their locations close to the esophagealgastric junction,and the other two cases were extended to the inferior bifurcation of the trachea.The circuitous pattern was observed in 16 cases,while reticulated pattern was seen in 36 cases.Collateral circulation identified 4 cases of single periesophageal varices (peri-EV) communication,3 cases of single hemiazygous vein,one case of single inferior vena cava,41 cases of mixed type (collateral communications of at least 2 of above mentioned types) and 3 cases of undetermined communications.Among all the cases,43 patients showed the communications between para-EV and peri-EV,while hemiazygous vein (43 cases) and inferior vena cava (5 cases) were also involved.CONCLUSION:Sixty-four-row multidetector computed tomograghy portal venography could display the location,morphology,origin,and collateral types of paraEV,which provides important and referable information for clinical management and disease prognosis.

  4. Innovation in mechanical weed control in crop rows

    NARCIS (Netherlands)

    Weide, van der R.Y.; Bleeker, P.O.; Achten, V.T.J.M.; Lotz, L.A.P.; Melander, B.; Fogelberg, F.

    2008-01-01

    Weed control within crop rows is one of the main problems in organic farming. For centuries, different weed removal tools have been used to reduce weeds in the crop rows. Stimulated by the demand from organic farmers, research in several European countries over the last decade has focused on mechani

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

    DEFF Research Database (Denmark)

    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 directions. ©1967 The American Institute of Physics...

  6. Analysis of indoor rowing motion using wearable inertial sensors

    NARCIS (Netherlands)

    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

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

    OpenAIRE

    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.

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

    NARCIS (Netherlands)

    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. Technical principles of dual source CT

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    International Nuclear Information System (INIS)

    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.)

  12. The Application of 64-detector Helical CT Angiography in the Evaluation of Artery of Lower Extremity in Follow-up after Artificial Vascular Graft%64排螺旋CT血管造影在下肢动脉病变人工血管旁路移植术后随访的价值

    Institute of Scientific and Technical Information of China (English)

    吴戈; 常鑫; 徐同江; 曾庆玉; 张藜莉; 霍健伟; 班润义; 邓茂松; 祖德贵; 李俊秋; 王军; 李坚

    2007-01-01

    目的 探讨64排螺旋CT血管造影在下肢动脉人工血管旁路移植术后随访的价值. 方法 2004-06-2006-05对连续68例下肢动脉人工血管旁路移植术后患者进行了64排螺旋CT血管造影检查,采用曲面重建(CPR),最大密度投影(MIP)及容积显示(VR)等多种后处理技术并结合原始图像进行综合分析. 结果 多种后处理图像相结合共显示移植血管87条,包括人工移植血管的位置及形态、内腔狭窄程度、侧枝循环和并发症等,符合临床诊断要求. 结论 64排螺旋CT血管造影术对人工移植血管的评价是可靠和准确的,可作为目前在下肢动脉病变人工血管旁路移植术后随访的首选影像诊断方法.

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

    International Nuclear Information System (INIS)

    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.)

  14. Computed Tomography (CT) -- Sinuses

    Science.gov (United States)

    ... 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 ...

  15. Computed Tomography (CT) -- Sinuses

    Medline Plus

    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 ...

  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

    Institute of Scientific and Technical Information of China (English)

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

    Energy Technology Data Exchange (ETDEWEB)

    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.)

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

    International Nuclear Information System (INIS)

    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.)

  19. Soft tissue imaging with photon counting spectroscopic CT

    Science.gov (United States)

    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

  20. 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

    Institute of Scientific and Technical Information of China (English)

    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.

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

    OpenAIRE

    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...

  2. Cardiac CT

    Energy Technology Data Exchange (ETDEWEB)

    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.)

  3. Biomechanical determinants of elite rowing technique and performance.

    Science.gov (United States)

    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

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

    International Nuclear Information System (INIS)

    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.)

  5. Recent Update on Radiation Dose Assessment for the State-of-the-Art Coronary Computed Tomography Angiography Protocols

    Science.gov (United States)

    Tan, Sock Keow; Yeong, Chai Hong; Ng, Kwan Hoong; Abdul Aziz, Yang Faridah; Sun, Zhonghua

    2016-01-01

    Objectives This study aimed to measure the absorbed doses in selected organs for prospectively ECG-triggered coronary computed tomography angiography (CCTA) using five different generations CT scanners in a female adult anthropomorphic phantom and to estimate the effective dose (HE). Materials and Methods Prospectively ECG-triggered CCTA was performed using five commercially available CT scanners: 64-detector-row single source CT (SSCT), 2 × 32-detector-row-dual source CT (DSCT), 2 × 64-detector-row DSCT and 320-detector-row SSCT scanners. Absorbed doses were measured in 34 organs using pre-calibrated optically stimulated luminescence dosimeters (OSLDs) placed inside a standard female adult anthropomorphic phantom. HE was calculated from the measured organ doses and compared to the HE derived from the air kerma-length product (PKL) using the conversion coefficient of 0.014 mSv∙mGy-1∙cm-1 for the chest region. Results Both breasts and lungs received the highest radiation dose during CCTA examination. The highest HE was received from 2 × 32-detector-row DSCT scanner (6.06 ± 0.72 mSv), followed by 64-detector-row SSCT (5.60 ± 0.68 and 5.02 ± 0.73 mSv), 2 × 64-detector-row DSCT (1.88 ± 0.25 mSv) and 320-detector-row SSCT (1.34 ± 0.48 mSv) scanners. HE calculated from the measured organ doses were about 38 to 53% higher than the HE derived from the PKL-to-HE conversion factor. Conclusion The radiation doses received from a prospectively ECG-triggered CCTA are relatively small and are depending on the scanner technology and imaging protocols. HE as low as 1.34 and 1.88 mSv can be achieved in prospectively ECG-triggered CCTA using 320-detector-row SSCT and 2 × 64-detector-row DSCT scanners. PMID:27552224

  6. 64-row MDCT perfusion of head and neck squamous cell carcinoma: technical feasibility and quantitative analysis of perfusion parameters

    Energy Technology Data Exchange (ETDEWEB)

    Faggioni, Lorenzo; Neri, Emanuele; Cerri, Francesca; Picano, Eugenia; Bartolozzi, Carlo [University of Pisa, Diagnostic and Interventional Radiology, Pisa (Italy); Seccia, Veronica; Muscatello, Luca; Franceschini, Stefano Sellari [University of Pisa, Division of Otorhinolaryngology, Pisa (Italy)

    2011-01-15

    To evaluate the technical feasibility of 64-row computed tomography (CT) quantitative perfusion imaging of head and neck squamous cell carcinoma (SCC). Twenty-nine patients with a total of 29 pathologically proven SCC underwent a cine-mode CT perfusion acquisition covering the lesion site. The acquisition started 10 s after intravenous injection of iodinated contrast material and lasted 50 s. On a dedicated workstation, regions of interest (ROI) were traced within the SCC, on a healthy portion of tissue (H), and on the ipsilateral sternocleidomastoid muscle (M). Blood flow (BF), blood volume (BV), mean transit time (MTT) and permeability-surface product (PS) were calculated. In SCC, BF, BV and PS were higher compared with H (p < 0.0001, p = 0.002 and p = 0.004, respectively) and M (p < 0.0001). Conversely, MTT was lower in SCC than in H (p = 0.0009) and M (p = 0.0003). All datasets were free from substantial motion artefacts and ROI misregistration phenomena. No substantial discomfort or adverse events were experienced by any of the patients. 64-row CT quantitative perfusion imaging allows head and neck SCC to be distinguished from normal tissues. (orig.)

  7. 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

    Institute of Scientific and Technical Information of China (English)

    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

  8. A Spider That Lays Its Eggs in Rows

    Directory of Open Access Journals (Sweden)

    Robert L. Edwards

    2000-01-01

    Full Text Available The small (2.5-3.0 mm, colorful metine spider, Homalometa nigritarsis Simon 1897, Family Tetragnathidae, has previously been reported from northern Mexico, Panama and the southern islands of the Lesser Antilles (Levi 1986. In the rain forest of northeastern Puerto Rico it is most frequently found with webbing on the larger outer concave surfaces of pendulous leaves. H. nigritarsis typically makes a circular, relatively flat retreat within which the female deposits two parallel rows of naked eggs. The rows are produced at intervals; as one row hatches another replaces it shortly thereafter. Evidence of up to four generations of rows has been observed. Above the retreat, and closely aligned with it, the spider builds a nearly invisible, delicate orb web, typically from edge to edge of the leaf (Fig. 1a and b. While retaining the traditional orb-web, H. nigritarsis has adopted a unique habitat and set of life history features.

  9. Effect of BMI on knee joint torques in ergometer rowing.

    Science.gov (United States)

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

    2013-12-01

    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 biomechanics during rowing in 10 normal weight (BMI 18-25), 10 overweight (BMI 25-30 kg·m⁻²), and 10 obese (BMI > 30 kg·m⁻²) participants. The results showed that BMI affects joint kinematics and primarily knee joint kinetics. The data revealed that high BMI leads to unfavorable knee joint torques, implying increased loads of the medial compartment in the knee joint that could be avoided by allowing more variable foot positioning on future designs of rowing ergometers.

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

    OpenAIRE

    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.

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

    Science.gov (United States)

    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)

  12. Hydrodynamic performance of multiple-row slotted breakwaters

    Science.gov (United States)

    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.

  13. Analysis of indoor rowing motion using wearable inertial sensors

    OpenAIRE

    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...

  14. QR factorization for row or column symmetric matrix

    Institute of Scientific and Technical Information of China (English)

    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.

  15. Clontarf to Curtin: Row AHEAD and Tertiary Affinity

    OpenAIRE

    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...

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

    DEFF Research Database (Denmark)

    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....

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

    Directory of Open Access Journals (Sweden)

    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.

  18. Evaluation of multimodal feedback effects on improving rowing competencies

    OpenAIRE

    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...

  19. New measuring and on water coaching device for rowing

    OpenAIRE

    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...

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

    Directory of Open Access Journals (Sweden)

    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.

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

    NARCIS (Netherlands)

    de Brouwer, Anouk J.; de Poel, Harjo J.; Hofmijster, Mathijs J.

    2013-01-01

    It is generally accepted that crew rowing requires perfect synchronization between the movements of the rowers. However, a long-standing and somewhat counterintuitive idea is that out-of-phase crew rowing might have benefits over in-phase (i.e., synchronous) rowing. In synchronous rowing, 5 to 6% of

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

    Science.gov (United States)

    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)

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

    Institute of Scientific and Technical Information of China (English)

    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.

  4. Preoperative assessment value of enhanced CT for axillary lymph node in breast cancer%增强CT对乳腺癌腋窝淋巴结术前评估的价值

    Institute of Scientific and Technical Information of China (English)

    高洋; 张文海; 李建一; 张扬; 贾实

    2013-01-01

    Objective To study the assessment value of enhanced CT for axillary lymph node in breast cancer.Methods 71 patients meeting the inclusion criteria in our hospital were reviewed.They had level Ⅲ lymph nodes pathologically confirmed for almost 2 years.CT scan by a 64-detector row scanner were performed from the lower edge of breast to neck.CT images were analyzed from these aspects:with or without lymph node enlargement; the size and shape of the lymph nodes; lymph node with or without enhancement.Through the determination of CT net increase value,the metastasizing lymph node signs were explored.Diagnostic index of axillary lymph nodes imaged by breast sonography and enhanced CT were calculated separately.The size of level Ⅲ lymph node and CT net increase value were statistically analyzed.The correlation of metastasizing level Ⅲ lymph node and tumor location was analyzed.Results The accuracy,sensitivity,specificity,and positive predictive value of diagnosed axillary lymph node was 70.4%,85.7%,64.0%,and 50.0% by three-dimensional ultrasound and 88.7%,90.6%,83.3%,and 94.1% by enhanced CT.The accuracy,sensitivity,specificity,and positive predictive value of diagnosed level Ⅲ lymph node was 95.8%,90.5%,98.0%,and 95.0% by enhanced CT.The maximal diameter of level Ⅲ lymph node was > (8.7 ± 1.3) mm and the short diameter was > (5.3 ±0.5) mm.CT net increase value was > (50.0 ±9.0) HU.The shape of lymph nodes was mainly round or oval solid.Conclusions The diagnosis rate for level Ⅲ lymph node is obviously higher by enhanced CT than by three-dimensional ultrasound.There is no obvious correlation between level Ⅲ lymph node and tumor location.%目的 研究增强CT对乳腺癌腋窝淋巴结评估的价值.方法 选择中国医科大学附属盛京医院乳腺外科近2年71例已病理证实第三站淋巴结(LevelⅢ)有转移的女性乳腺癌患者.采用Siemens64排CT,扫描范围自颈部至乳房下缘.分析增强CT影像:

  5. Computed Tomography (CT) -- Head

    Medline Plus

    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 ...

  6. Computed Tomography (CT) -- Sinuses

    Medline Plus

    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 ...

  7. Using the 64-slice Perfusion CT to Evaluate the Oxygen Tension(pO2) in the Rabbit VX2 Tumor Model: An Experimental Study%64层灌注CT评价兔VX2体部肿瘤模型氧分压的实验研究

    Institute of Scientific and Technical Information of China (English)

    孙昌进; 肖明勇; 阴俊; 于金明; 郞锦义; 王光辉; 李超; 李涛; 罗云秀; 吕海波; 张德康; 李彦; 黄建鸣

    2013-01-01

    Objective: To investigate the role of the 64-slice perfusion CT in the evaluation of the oxygen tension ( pO2 ) in the rabbit VX2 tumor model. Methods: Forty-five rabbit VX2 brain tumor model established successfully were examined with 64-detector row CT. Tumor specimens were assessed for the oxygen tension ( pO2 ) , perfusion, blood volume ( BV) , peak enhancement intensity ( PEI) and time to peak (TTP) , and Pearson correlation coefficients were conducted to represent the relationships between the perfusion parameters and pO2 of the tumor. pO2was measured by oxygen-sensitive electrodes guided by perfusion CT images. Results: Mean values for perfusion,BV,PEI, TTP and pO2 of the 45 tumors were 27. 102 ± 26. 723ml/min, 22. 1 96 ± 13. 680ml/100g,43. 456 ±28.73 HU, 38.823 ±14.759 sec,and 15.981 ± 14.815mmHg, respectively. BV,PEI, TTP were not significant correlated with pO2 (r =0.271, 0. 253 、- 0. 18 , P > 0. 05 ) , whereas positively correlation was found between perfusion with pO2 ( r = 0. 673, P = 0. 00 ). Conclusion: The perfusion value from 64-slice spiral CT perfusion imaging might to have ability to evaluate the tumor pO2%目的:利用64层灌注CT评价兔VX2肿瘤模型氧分压并与氧微电极法对照.方法:对45只成功建模兔VX2脑瘤模型行灌注CT检查.测量脑瘤兴趣区灌注值(perfusion)、血容量(blood volume,BV)、达峰时间(time to peak TTP)、最大峰值(peak enhancement intensity,PEI).结果与该兴趣区氧微电极法测得氧分压(PO2)对照.结果:45例成功建模兔VX2脑瘤兴趣区灌注值范围为1.3 ml/min~127.0 ml/min,平均为27.102 ml/min±26.723 ml/min;BV为1.2 ml/100g~53.1ml/100g,平均为22.196 ml/100g±13.680ml/100g,PEI为8.7 HU~124.6HU,平均为43.456 HU±28.73 HU; TTP为8.2 sec~62.5 sec,平均为38.823 sec±14.759 sec;对应区域PO2为0.14 mmHg~46.70mmHg,平均为15.981 mmHg±14.815mmHg.灌注值与对应区域PO2相关系数为0.673,有统计学意义(P=0.00).BV

  8. Row Spacing, Landscape Position, and Maize Grain Yield

    Directory of Open Access Journals (Sweden)

    Gustavo Ángel Maddonni

    2014-01-01

    Full Text Available The use of narrow row spacing for the different landscape positions of a field could punish maize (Zea mays L. grain yield. Two experiments were conducted (2006/07 and 2007/08 at different landscape positions in the Inland Pampas of Argentina. Hybrid DK190MG was grown at the commonest plant density used at each landscape position (approximately 5.1 plants/m2 at the summit, 6.5 plants/m2 at shoulder-slope position, and 7.6 plants/m2 at foot-slope position with three row spacings (0.38 m, 0.52 m, and 0.38 m in a 2×1 skip-row pattern. At the silking stage of maize crops, soil water content (0–200 cm depth and maximum light capture differed (0.05row spacings. Differences in grain yield among landscape positions (mean 806, 893, and 1104 g/m2 at the summit, shoulder-slope position, and foot-slope position, resp. were related to kernel number/m2 (r=0.94, which was closely related (r=0.90 to light capture around silking. Grain yield reductions (6 to 20% were recorded when crops were cultivated in rows 0.38 m apart. The skip-row pattern did not improve grain yield. Maize grain yield was optimized in rows 0.52 m apart along the sandy landscape positions of the fields.

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

    International Nuclear Information System (INIS)

    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.)

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

    International Nuclear Information System (INIS)

    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

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

    OpenAIRE

    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...

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

    OpenAIRE

    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...

  13. Plant population and row spacing on biomass sorghum yield performance

    Directory of Open Access Journals (Sweden)

    Andre May

    2015-01-01

    Full Text Available ABSTRACT: Biomass sorghum is one of the most promising crops for the production of electricity through the burning in high-pressure boilers, due to its high calorific value, high yield, seed propagation, short cycle, and to the possibility of full mechanization of its agricultural processes. However, there is still a lack of information about its cultural practices. To this end, this research aimed to evaluate the influence of row spacing and plant population on the yield performance of biomass sorghum. The experimental design was a randomized block, in factorial scheme of 4 x 4, with four row spacings (0.5, 0.7, 0.9 and 1.1m, and four plant populations (80,000; 100,000; 120,000 and 140,000 plants ha-1, with three replications. The characteristics evaluated were: plant height, stem diameter, number of leaves, number of tillers per plant, fresh weight per plant and biomass. Total biomass yield was greatly influenced by the row spacing, showing a sharp reduction when row spacing increased, in the two years of study, changing from 180.27 to 114.42t ha-1 in the 2012/13 crop year, and from 146.50 to 102.56t ha-1 in the 2013/14 crop year, for 0.5 and 1.1m between rows, respectively. The lowest yields observed in the second year of the study were due to unfavorable weather conditions in the period.

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

    Science.gov (United States)

    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

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

    Science.gov (United States)

    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

  16. Low-dose multidetector-row CT-angiography of abdominal aortic aneurysm after endovascular repair

    Energy Technology Data Exchange (ETDEWEB)

    Iezzi, R., E-mail: iezzir@virgilio.it [Department of Bioimaging and Radiological Sciences, Institute of Radiology, ' A. Gemelli' Hospital - Catholic University, L.go A Gemelli 8, 00168 Rome (Italy); Department of Clinical Science and Bioimaging, Section of Radiology, University ' G. D' Annunzio' , Chieti (Italy); Cotroneo, A.R.; Giammarino, A. [Department of Clinical Science and Bioimaging, Section of Radiology, University ' G. D' Annunzio' , Chieti (Italy); Spigonardo, F. [Department of Vascular Surgery, University ' G. D' Annunzio' , Chieti (Italy); Storto, M.L. [Department of Clinical Science and Bioimaging, Section of Radiology, University ' G. D' Annunzio' , Chieti (Italy)

    2011-07-15

    Purpose: To investigate the possibility of reducing radiation dose exposure while maintaining image quality using multidetector computed tomography angiography (MDCTA) with high-concentration contrast media in patients undergoing follow-up after endovascular aortic repair (EVAR) to treat abdominal aortic aneurysm. Materials and methods: In this prospective, single center, intra-individual study, patients underwent two consecutive MDCTA scans 6 months apart, one with a standard acquisition protocol (130 mAs/120 kV) and 120 mL of iomeprol 300, and one using a low dose protocol (100 mAs/80 kV) and 90 mL of iomeprol 400. Images acquired during the arterial phase of contrast enhancement were evaluated both qualitatively and quantitatively for image noise and intraluminal contrast enhancement. Results: Thirty adult patients were prospectively enrolled. Statistically significantly higher attenuation values were measured in the low-dose acquisition protocol compared to the standard protocol, from the suprarenal abdominal aorta to the common femoral artery (p < 0.0001; all vascular segments). Qualitatively, image quality was judged significantly (p = 0.0002) better with the standard protocol than with the low-dose protocol. However, no significant differences were found between the two protocols in terms of contrast-to-noise ratio (CNR) (13.63 {+-} 6.97 vs. 11.48 {+-} 8.13; p = 0.1058). An overall dose reduction of up to 74% was observed for the low-dose protocol compared with the standard protocol. Conclusion: In repeat follow-up examinations of patients undergoing EVAR for abdominal aortic aneurysm, a low-dose radiation exposure acquisition protocol provides substantially reduced radiation exposure while maintaining a constant CNR and good image quality.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2008-05-15

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

  18. A parallelization of the row-searching algorithm

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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

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

    Science.gov (United States)

    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.

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

    International Nuclear Information System (INIS)

    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. Computed Tomography (CT) -- Head

    Medline Plus

    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 ...

  3. Clontarf to Curtin: Row AHEAD and Tertiary Affinity

    Directory of Open Access Journals (Sweden)

    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.

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

    OpenAIRE

    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...

  5. Murphy elements from the double-row transfer matrix

    International Nuclear Information System (INIS)

    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)

  6. Row Spacing, Landscape Position, and Maize Grain Yield

    OpenAIRE

    Gustavo Ángel Maddonni; Joaquín Martínez-Bercovich

    2014-01-01

    The use of narrow row spacing for the different landscape positions of a field could punish maize (Zea mays L.) grain yield. Two experiments were conducted (2006/07 and 2007/08) at different landscape positions in the Inland Pampas of Argentina. Hybrid DK190MG was grown at the commonest plant density used at each landscape position (approximately 5.1 plants/m2 at the summit, 6.5 plants/m2 at shoulder-slope position, and 7.6 plants/m2 at foot-slope position) with three row spacings (0.38 m, 0....

  7. Evaluation of multimodal feedback effects on improving rowing competencies

    Directory of Open Access Journals (Sweden)

    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.

  8. Commercial software upgrades may significantly alter Perfusion CT parameter values in colorectal cancer

    Energy Technology Data Exchange (ETDEWEB)

    Goh, Vicky [Mount Vernon Hospital, Paul Strickland Scanner Centre, Northwood, Middlesex (United Kingdom); Shastry, Manu; Endozo, Raymondo; Groves, Ashley M. [University College Hospital, Institute of Nuclear Medicine, London (United Kingdom); Engledow, Alec; Peck, Jacqui [University College Hospital, Department of Surgery, London (United Kingdom); Reston, Jonathan; Wellsted, David M. [University of Hertfordshire, Centre for Lifespan and Chronic Illness Research (CLiCIR), Hatfield (United Kingdom); Rodriguez-Justo, Manuel [University College Hospital, Department of Histopathology, London (United Kingdom); Taylor, Stuart A.; Halligan, Steve [University College Hospital, Specialist Radiology, London (United Kingdom)

    2011-04-15

    To determine how commercial software platform upgrades impact on derived parameters for colorectal cancer. Following ethical approval, 30 patients with suspected colorectal cancer underwent Perfusion CT using integrated 64 detector PET/CT before surgery. Analysis was performed using software based on modified distributed parameter analysis (Perfusion software version 4; Perfusion 4.0), then repeated using the previous version (Perfusion software version 3; Perfusion 3.0). Tumour blood flow (BF), blood volume (BV), mean transit time (MTT) and permeability surface area product (PS) were determined for identical regions-of-interest. Slice-by-slice and 'whole tumour' variance was assessed by Bland-Altman analysis. Mean BF, BV and PS was 20.4%, 59.5%, and 106% higher, and MTT 14.3% shorter for Perfusion 4.0 than Perfusion 3.0. The mean difference (95% limits of agreement) were +13.5 (-44.9 to 72.0), +2.61 (-0.06 to 5.28), -1.23 (-6.83 to 4.36), and +14.2 (-4.43 to 32.8) for BF, BV, MTT and PS respectively. Within subject coefficient of variation was 36.6%, 38.0%, 27.4% and 60.6% for BF, BV, MTT and PS respectively indicating moderate to poor agreement. Software version upgrades of the same software platform may result in significantly different parameter values, requiring adjustments for cross-version comparison. (orig.)

  9. Three-dimensional CT laryngography: clinical application

    Energy Technology Data Exchange (ETDEWEB)

    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. Brain perfusion CT for acute stroke using a 256-slice CT: improvement of diagnostic information by large volume coverage

    Energy Technology Data Exchange (ETDEWEB)

    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.)

  11. Cooperative catalysis with first-row late transition metals

    NARCIS (Netherlands)

    J.I. van der Vlugt

    2012-01-01

    Cooperative catalysis with first-row transition metals holds much promise for future developments regarding sustainable, selective transformations, including e.g. alkenes, dienes and a variety of small molecules such as CO2, N2 and water. This non-exhaustive analysis of the current state-of-the-art

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

    Science.gov (United States)

    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…

  13. Rowing Crew Coordination Dynamics at Increasing Stroke Rates

    NARCIS (Netherlands)

    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

  14. Effect of row orientation on energy balance components

    Science.gov (United States)

    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...

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

    Institute of Scientific and Technical Information of China (English)

    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.

  16. Optimization of Inter-Row Spacing and Nitrogen Rate for the Application of Vision Guided Inter-Row weeding in Organic Spring Cereals

    DEFF Research Database (Denmark)

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

    2016-01-01

    -row spacing and nitrogen rate on weed and crop growth. Results are reported from two years field experiments with spring barley and spring wheat. It was aimed to maintain a constant seed rate for all five row spacing studied (12.5, 15, 20, 25 and 30 cm), which gave a higher crop density in the rows...... with increasing row spacing. A denser intra-row crop stand would improve the suppression of surviving intra-row weeds and partly compensate for the more weed growth that wider row spacing would cause by allowing more light penetration into the crop canopy. It was found that maintaining the seed rate when...... tall-growing and tap-rooted weed species have been major drawbacks. New camera technology capable of detecting crop rows makes it possible to employ selective weed control in spring cereals. Normally cereals are grown at 12.5 cm row spacing in Northern Europe but even a moderate extension of the row...

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

    Directory of Open Access Journals (Sweden)

    M Gol Mohammadi

    2014-04-01

    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

  18. Vision-GPS Fusion for Guidance of an Autonomous Vehicle in Row Crops

    DEFF Research Database (Denmark)

    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...... 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 generation...... is thus controlled by location relative to the local field while the actual path execution is carried out in absolute GPS coordinates. The solution is a system that fuse data from a relative and an absolute measurement system while ensuring accurate row operation at high work rates....

  19. Acquiring 4D Thoracic CT Scans Using Ciné CT Acquisition

    Science.gov (United States)

    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).

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

    OpenAIRE

    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...

  1. A Comparison of Kinematics and Performance Measures of Two Rowing Ergometers

    OpenAIRE

    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...

  2. Mildew-resistant mutants induced in North American two- and six-rowed malting barley cultivars

    DEFF Research Database (Denmark)

    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...

  3. 77 FR 25073 - Special Local Regulation; Hebda Cup Rowing Regatta, Trenton Channel; Detroit River, Wyandotte, MI

    Science.gov (United States)

    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...

  4. 33 CFR 100.724 - Annual Augusta Invitational Rowing Regatta; Savannah River, Augusta, GA.

    Science.gov (United States)

    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,...

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    International Nuclear Information System (INIS)

    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.

  7. CT and MR imaging of the thoracic aorta

    Directory of Open Access Journals (Sweden)

    Di Cesare Ernesto

    2016-06-01

    Full Text Available At present time, both CT and MRI are valuable techniques in the study of the thoracic aorta. Nowadays, CT represents the most widely employed technique for the study of the thoracic aorta. The new generation CTs show sensitivities up to 100% and specificities of 98-99%. Sixteen and wider row detectors provide isotropic pixels, mandatory for the ineludible longitudinal reconstruction. The main limits are related to the X-ray dose expoure and the use of iodinated contrast media. MRI has great potential in the study of the thoracic aorta. Nevertheless, if compared to CT, acquisition times remain longer and movement artifact susceptibility higher. The main MRI disadvantages are claustrophobia, presence of ferromagnetic implants, pacemakers, longer acquisition times with respect to CT, inability to use contrast media in cases of renal insufficiency, lower spatial resolution and less availability than CT. CT is preferred in the acute aortic disease. Nevertheless, since it requires iodinated contrast media and X-ray exposure, it may be adequately replaced by MRI in the follow up of aortic diseases. The main limitation of MRI, however, is related to the scarce visibility of stents and calcifications.

  8. CT lymphography-guided sentinel lymph node biopsy

    International Nuclear Information System (INIS)

    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.)

  9. Computed Tomography (CT) -- Sinuses

    Medline Plus

    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 ...

  10. Computed Tomography (CT) -- Head

    Medline Plus

    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 ...

  11. Computed Tomography (CT) -- Sinuses

    Medline Plus

    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- ...

  12. Computed Tomography (CT) -- Head

    Medline Plus

    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- ...

  13. Computed Tomography (CT) -- Sinuses

    Medline Plus

    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 ...

  14. Computed Tomography (CT) -- Sinuses

    Medline Plus

    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 ...

  15. Computed Tomography (CT) -- Head

    Medline Plus

    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 ...

  16. Computed Tomography (CT) -- Sinuses

    Medline Plus

    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 ...

  17. Computed Tomography (CT) -- Head

    Medline Plus

    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 ...

  18. Computed Tomography (CT) -- Sinuses

    Medline Plus

    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, ...

  19. Computed Tomography (CT) -- Head

    Medline Plus

    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 ...

  20. Computed Tomography (CT) -- Head

    Medline Plus

    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, ...

  1. Computed Tomography (CT) -- Sinuses

    Medline Plus

    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, ...

  2. Computed Tomography (CT) -- Head

    Medline Plus

    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 ...

  3. Computed Tomography (CT) -- Sinuses

    Medline Plus

    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 ...

  4. CT angiography and CT perfusion in acute ischemic stroke

    NARCIS (Netherlands)

    Seeters, T. van

    2016-01-01

    CT angiography and CT perfusion are used in patients with acute ischemic stroke for diagnostic purposes and to select patients for treatment. In this thesis, the reproducibility of CT angiography and CT perfusion is examined, the additional value of CT angiography and CT perfusion for stroke outcome

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

    Energy Technology Data Exchange (ETDEWEB)

    Wiesner, Walter [University Hospital Basel, Institute of Diagnostic Radiology, Basel (Switzerland); Clinic Stephanshorn, Medical Radiology Center, St. Gallen (Switzerland); Hauser, Andreas; Steinbrich, Wolfgang [University Hospital Basel, Institute of Diagnostic Radiology, Basel (Switzerland)

    2004-12-01

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

  6. CT Colonography (Virtual Colonoscopy)

    Science.gov (United States)

    ... 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 ...

  7. Computed Tomography (CT) -- Head

    Medline Plus

    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 ...

  8. Computed Tomography (CT) -- Sinuses

    Medline Plus

    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 ...

  9. Evaluation of pituitary adenomas by multidirectional multislice dynamic CT

    International Nuclear Information System (INIS)

    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

  10. Generalized Row-Action Methods for Tomographic Imaging

    DEFF Research Database (Denmark)

    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...... us to derive new incremental algorithms for tomographic imaging that incorporate different types of prior information via regularization. We demonstrate the efficacy of the approach with some numerical examples....

  11. Monitoring and evaluation of rowing performance using mobile mapping data

    Science.gov (United States)

    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.

  12. Don’t Rock the Boat: How Antiphase Crew Coordination Affects Rowing

    OpenAIRE

    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. Policing Rock Bottom: Regulation, Rehabilitation, and Resistance on Skid Row

    OpenAIRE

    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...

  14. Three-Dimensional Turbomachine-Blade-Row Analysis Code

    Science.gov (United States)

    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.

  15. Random matrix ensembles with column/row constraints: II

    International Nuclear Information System (INIS)

    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. Rowing Crew Coordination Dynamics at Increasing Stroke Rates

    OpenAIRE

    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...

  17. Marketing cardiac CT programs.

    Science.gov (United States)

    Scott, Jason

    2010-01-01

    There are two components of cardiac CT discussed in this article: coronary artery calcium scoring (CACS) and coronary computed tomography angiography (CCTA).The distinctive advantages of each CT examination are outlined. In order to ensure a successful cardiac CT program, it is imperative that imaging facilities market their cardiac CT practices effectively in order to gain a competitive advantage in this valuable market share. If patients receive quality care by competent individuals, they are more likely to recommend the facility's cardiac CT program. Satisfied patients will also be more willing to come back for any further testing.

  18. Optimization of Rowing Specific Training by Studying the Stages Evaluation

    Directory of Open Access Journals (Sweden)

    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.

  19. The use of IR barrier film for row covers in vegetable crops

    International Nuclear Information System (INIS)

    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)

  20. Vision-GPS Fusion for Guidance of an Autonomous Vehicle in Row Crops

    DEFF Research Database (Denmark)

    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 generation...

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

    Institute of Scientific and Technical Information of China (English)

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

    2009-01-01

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

  2. Row, Row, Row Your Boat...

    Institute of Scientific and Technical Information of China (English)

    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.

  3. Congenital tracheoesophageal fistula successfully diagnosed by CT esophagography

    Institute of Scientific and Technical Information of China (English)

    Koichi Nagata; Yoshito Kamio; Tamaki Ichikawa; Mitsutaka Kadokura; Akihiko Kitami; Shungo Endo; Haruhiro Inoue; Shin-Ei Kudo

    2006-01-01

    Tracheoesophageal fistula (TEF) or bronchoesophageal fistula may be congenital, inflammatory, neoplastic,or secondary to trauma. Congenital TEF or bronchoesophageal fistula is usually associated with esophageal atresia and is readily diagnosed in infancy.But if it is not associated with esophageal atresia, it may persist until adulthood. Some theories have been proposed to explain this delay in diagnosis. We present a case of a 70-year-old man with congenital TEF. The TEF was successfully diagnosed by multidetector-row CT esophagography.

  4. Application of large aperture spiral CT in radiotherapy simulation positioning%大孔径螺旋CT在放疗模拟定位中的应用研究

    Institute of Scientific and Technical Information of China (English)

    李雪南; 修霞; 李高峰

    2013-01-01

    目的:探讨大孔径16排螺旋CT在放疗模拟定位中的应用。方法:应用大孔径16排螺旋CT进行乳腺癌保乳术后根治性放疗乳腺切线野的CT模拟定位,并对CT模拟定位技术与传统X射线模拟定位技术进行比较,同时与单排螺旋CT的图像进行比较。结果:大孔径16排螺旋CT在放疗模拟定位中的应用避免了因患者体位受限而造成的误差;大孔径16排螺旋CT模拟机的定位验证误差均优于传统X射线模拟机;其图像质量优于单排螺旋CT。结论:大孔径16排螺旋CT模拟定位机的应用,使得放疗定位更加精确,计划和治疗更加准确。%Objective:To discuss application of large aperture 16 row spiral CT in radiotherapy simulation positioning. Methods: To apply CT simulation positioning with large aperture 16 row spiral CT for the breast tangential field by early breast cancer after breast conserving surgery and radical radiotherapy. Compare CT-simulation and X-ray conventional positioning technique and Compare large aperture 16 row spiral CT and single row spiral CT image. Results: The application of large aperture 16 row spiral CT avoided the error because of body limited. Large aperture 16 row spiral CT simulation position validation error is superior to X-ray positioning. Its image quality is better than that of single row spiral CT. Conclusion:The application of large aperture 16 row spiral CT make simulation positioning more accurate, planned and treatment more accurate, it can provide guarantee of accurate simulation positioning for accurate plan and treatment.

  5. Beziehung zwischen primären Multi-Slice-CT-Befunden und posttraumatischer Lebensqualität bei polytraumatisierten Patienten

    OpenAIRE

    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...

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

    Energy Technology Data Exchange (ETDEWEB)

    Symersky, Petr [Onze Lieve Vrouwe Gasthuis, Department of Cardiothoracic Surgery, Oosterpark 9, P.O box 95500, Amsterdam (Netherlands); Academic Medical Center, Department of Cardiothoracic Surgery, Amsterdam (Netherlands); Budde, Ricardo P.J. [University Medical Center, Department of Radiology, Utrecht (Netherlands); Westers, Paul [Julius Center for Health Sciences and Primary Care, Department of Biostatistics, Utrecht (Netherlands); Mol, Bas A.J.M. de [Academic Medical Center, Department of Cardiothoracic Surgery, Amsterdam (Netherlands); University of Technology Eindhoven, Department of Biomedical Engineering, Eindhoven (Netherlands); Prokop, Mathias [Radboud University Nijmegen Medical Center, Department of Radiology, Nijmegen (Netherlands)

    2011-10-15

    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. 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 stationary and pulsatile conditions. Artifacts and radiopaque component volumes were quantified with thresholds based on surrounding structures and valvular components. Hypodense artifacts volumes (mm{sup 3}) were 1,029 {+-} 147, 535 {+-} 53, 371 {+-} 16, and 366 {+-} 18 for the SJM, MH, CM and ON-X valves (p < 0.001 except for the latter two valves p = 0.43). Hyperdense artifact volumes were 3,546 {+-} 141, 2,387 {+-} 103, 2,003 {+-} 102, and 3,033 {+-} 31 for the SJM, MH, CM and ON-X valve, respectively (all differences p < 0.001). Leaflet motion affected hypodense (F = 41.5, p < 0.001) and hyperdense artifacts (F = 53.7, p < 0.001). Closed and moving leaflets were associated with the least and the most artifacts respectively (p < 0.001, both artifact types). Both valve design and leaflet motion affect PHV-induced artifacts. Best imaging results may be expected for the CM valve during phases in which the leaflets are closed. (orig.)

  7. Role of Multidetector CT in Evaluation of Acute Chest Pain: Non-Cardiac Vascular and Pulmonary Causes

    Directory of Open Access Journals (Sweden)

    Rania S Sayed *, Hisham M Mansour **, Mohammad H Khaleel ***, Sherif H Abo Gamra ** and Merhan A Nasr

    2013-04-01

    Full Text Available Background: Triage of patients with acute chest pain is one of the most important issues currently facing physicians in the emergency department. Acute chest pain may be a symptom of a number of serious conditions and is generally considered a medical emergency. The causes of acute chest pain range from non-serious to life threatening. A rapid, accurate and cost-effective approach for the evaluation of emergency department patients with chest pain is needed. Aim of the work: This work aims to emphasize the role of multidetector CT in assessment of non-cardiac vascular and pulmonary causes of acute chest pain.Method: The studied group included 89 patients (59 men and 30 women presented by acute chest pain. All patients were subjected to MDCT and/or MDCT angiography using a Toshiba 64 detectors CT scanner. Results: The high spatial resolution and relatively non-invasive nature make MSCT angiography a strong and serious competitor to established vascular imaging techniques. Having the additional ability to simultaneously acquire information on other organs, which enables the early diagnosis of complications. Conclusion: Continued technical improvements in acquisition speed and spatial resolution of computed tomography images, and development of more efficient image reconstruction algorithms which reduce patient exposure to radiation and contrast result in increased popularity of MDCT.

  8. New frontiers in CT imaging of airway disease

    Energy Technology Data Exchange (ETDEWEB)

    Grenier, Philippe A.; Beigelman-Aubry, Catherine [Department of Radiology, University Pierre et Marie Curie, Paris (France); Fetita, Catalin; Preteux, Francoise [Institut National des Telecommunications, Department ARTEMIS, Evry (France); Brauner, Michel W. [Avicenne Hospital, UFR SMBH Paris XIII, Bobigny (France); Lenoir, Stephane [Institut Mutualiste Montsouris, Paris (France)

    2002-05-01

    Combining helical volumetric CT acquisition and thin-slice thickness during breath hold provides an accurate assessment of both focal and diffuse airway diseases. With multiple detector rows, compared with single-slice helical CT, multislice CT can cover a greater volume, during a simple breath hold, and with better longitudinal and in-plane spatial resolution and improved temporal resolution. The result in data set allows the generation of superior multiplanar and 3D images of the airways, including those obtained from techniques developed specifically for airway imaging, such as virtual bronchography and virtual bronchoscopy. Complementary CT evaluation at suspended or continuous full expiration is mandatory to detect air trapping that is a key finding for depicting an obstruction on the small airways. Indications for CT evaluation of the airways include: (a) detection of endobronchial lesions in patients with an unexplained hemoptysis; (b) evaluation of extent of tracheobronchial stenosis for planning treatment and follow-up; (c) detection of congenital airway anomalies revealed by hemoptysis or recurrent infection; (d) detection of postinfectious or postoperative airway fistula or dehiscence; and (e) diagnosis and assessment of extent of bronchiectasis and small airway disease. Improvement in image analysis technique and the use of spirometrically control of lung volume acquisition have made possible accurate and reproducible quantitative assessment of airway wall and lumen areas and lung density. This contributes to better insights in physiopathology of obstructive lung disease, particularly in chronic obstructive pulmonary disease and asthma. (orig.)

  9. Mode of inheritance and combining abilities for kernel row number, kernel number per row and grain yield in maize (Zea mays L.

    Directory of Open Access Journals (Sweden)

    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.

  10. Multidetector-row spiral computed tomography in chest emergencies; MSCT bei thorakalen Notfaellen

    Energy Technology Data Exchange (ETDEWEB)

    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

  11. Appearance and impact of post-operative intracranial clips and coils on whole-brain CT angiography and perfusion

    International Nuclear Information System (INIS)

    Background: To evaluate the effect of vascular clips and endovascular coils placed for intracranial aneurysms and arteriovenous malformations on whole-brain computed tomography (CT) angiography and perfusion. Methods: A 320-detector row dynamic volume CT system imaged 11 patients following surgical placement of vascular clips or endovascular coils. The extent of clip and coil subtraction by automated software was evaluated using CT digital subtraction angiography and CT perfusion. Impact on CT perfusion values by retained intracranial devices was compared to age- and gender-matched controls. Results: Clip and coil subtraction on CT angiography was graded as good in 8 and moderate in 3 cases. A residual neck and additional aneurysm were noted in 1 of 11 patients. Post-procedural axial slice level CT perfusion values decreased in reliability with increasing proximity to the metallic devices secondary to beam hardening. However, the intracranial devices did not affect axial slice level CTP values of cerebral blood volume, cerebral blood flow and mean transit time outside of the level of the device. Time to peak values was globally decreased outside of the immediate vascular intervention region. Conclusions: Advances in CT technology have provided clinically useful subtraction of intracranial clips and coils. While CT perfusion values were altered in device subtraction areas and within beam hardening artifact areas; they can provide valuable postoperative information on whole-brain hemodynamics. In selected cases, the combination of CT angiography and whole-brain CT perfusion can offer an alternative to conventional angiography that is a more invasive option.

  12. Plant, soil, and shadow reflectance components of row crops

    Science.gov (United States)

    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.

  13. Quality Function Deployment For Row House Construction In Real Estate

    Directory of Open Access Journals (Sweden)

    Sukhlal Mujalda

    2015-06-01

    Full Text Available Abstract House construction for real state is the current demand to satisfy the different categories of customer. Various techniques are available to satisfy the customer demand like QFD. Using the QFD house of quality modal we were able to understand the fundamental customer quality and care requirement within the real estate construction. This paper represent a simple case using QFD on the design phase of a real estate construction project as a tool of improvement for feature of middle class row house unit.

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

    Medline Plus

    Full Text Available ... 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 ...

  15. Validity of blood flow measurement using 320 multi-detectors CT and first-pass distribution theory: a phantom study

    Science.gov (United States)

    Chen, Jun; Yu, Xuefang; Xu, Shaopeng; Zhou, Kenneth J.

    2015-03-01

    To evaluate the feasibility of measuring the myocardial blood flow using 320 row detector CT by first-pass technique. Heart was simulated with a container that was filled with pipeline of 3mm diameter; coronary artery was simulated with a pipeline of 2 cm diameter and connected with the simulated heart. The simulated coronary artery was connected with a big container with 1500 ml saline and 150ml contrast agent. One pump linking with simulated heart will withdraw with a speed of 10 ml/min, 15 ml/min, 20 ml/min, 25 ml/min and 30 ml/min. First CT scan starts after 30 s of pumpback with certain speed. The second CT scan starts 5 s after first CT scans. CT images processed as follows: The second CT scan images subtract first CT scan images, calculate the increase of CT value of simulated heart and the CT value of the unit volume of simulated coronary artery and then to calculate the total inflow of myocardial blood flow. CT myocardial blood flows were calculated as: 0.94 ml/s, 2.09 ml/s, 2.74 ml/s, 4.18 ml/s, 4.86 ml/s. The correlation coefficient is 0.994 and r2 = 0.97. The method of measuring the myocardial blood flow using 320 row detector CT by 2 scans is feasible. It is possible to develop a new method for quantitatively and functional assessment of myocardial perfusion blood flow with less radiation does.

  16. Emergencies in the retroperitoneum: assessment of spread of disease by helical CT

    Energy Technology Data Exchange (ETDEWEB)

    Scialpi, M. E-mail: michelescialpi@libero.it; Scaglione, M.; Angelelli, G.; Lupattelli, L.; Resta, M.C.; Resta, M.; Rotondo, A

    2004-04-01

    Acute pancreatitis, leaking abdominal aortic aneurysm, and renal trauma frequently occur in the setting of patients with abdominal nontraumatic and traumatic injury; it represents the most urgent conditions that may determine the presence of fluid collections or haematoma in the retroperitoneum. Single spiral CT and multidetector-row CT (MDCT) play an important role in diagnosis of retroperitoneal emergencies, providing useful informations on the type, site, extent and management of the fluid collections. An accurate CT assessment requires the awareness of the existence of dissectable retroperitoneal fascial planes. Fluid collections or haematoma tends to escape the retroperitoneal site of origin into planes extend from the diaphragm to the pelvic floor. We assess the multicompartimental anatomy of the retroperitoneum and the pathway of spread of the most frequent retroperitoneal fluid collections or haematoma by helical CT.

  17. Rectosigmoid endometriosis: Comparison between CT water enema and video laparoscopy

    International Nuclear Information System (INIS)

    Aim: To evaluate the accuracy of water enema computed tomography (CT) for predicting the location of endometriosis in patients with contraindications to magnetic resonance imaging (MRI), focusing on rectosigmoid lesions and having laparoscopic and histological data as the reference standard. Materials and methods: Thirty-three women (mean age 33.4 ± 3.1 years) suspected of having deep pelvic endometriosis underwent 64-row CT and video laparoscopy within 4 weeks. Two radiologists blinded to the clinical data evaluated the CT images obtained after colonic retrograde distension using water as the contrast medium, and a comparison with laparoscopic and histological findings was performed. CT sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and diagnostic accuracy were calculated. The radiation dose to patients was estimated. Cohen's weighted kappa (κ) test was used to evaluate the interobserver agreement. Results: In 23 out of 33 patients (69%) intestinal implants were found at surgery and pathological examinations. CT confirmed the diagnosis of rectosigmoid endometriosis in 20 out of 23 implants. Three nodules located on the proximal sigmoid colon (two serosal lesions and one infiltrating the muscularis layer) with a diameter of less than 1 cm were not diagnosed. CT sensitivity, specificity, PPV, NPV, and accuracy values were 87, 100, 100, 77, and 91%, respectively. The mean effective dose estimate was 6.30 ± 1.7 mSv. Almost perfect agreement between the two readers was found (k = 0.84). Conclusion: Water enema CT can play a role in the diagnosis of bowel endometriosis and represents another accurate potential tool for video laparoscopic approaches, especially in patients for whom MRI is contraindicated

  18. Fixed versus free-floating stretcher mechanism in rowing ergometers : mechanical aspects

    OpenAIRE

    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...

  19. Prediction of Rowing Ergometer Performance from Functional Anaerobic Power, Strength and Anthropometric Components

    OpenAIRE

    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...

  20. (Originals) Anthropometric and Physiological Factors Predicting 2000 m Rowing Ergometer Performance Time

    OpenAIRE

    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...

  1. Changes in Rowing Technique Over a Routine One Hour Low Intensity High Volume Training Session

    OpenAIRE

    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...

  2. Muscle Synergies of Untrained Subjects during 6 min Maximal Rowing on Slides and Fixed Ergometer

    OpenAIRE

    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...

  3. A COMPARISON OF KINEMATICS AND PERFORMANCE MEASURES OF TWO ROWING ERGOMETERS

    Directory of Open Access Journals (Sweden)

    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

  4. Cross-sectional analysis of rowing power and technique of German junior women in the eight

    OpenAIRE

    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...

  5. Knee CT scan

    Science.gov (United States)

    Risks of CT scans include: Exposure to radiation Allergy to contrast dye CT scans give off more radiation than ... injected contrast dye. The most common type of contrast contains ... you have this an iodine allergy. If you need to have this kind of ...

  6. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... image recording plate. Bones appear white on the x-ray; soft tissue, such as organs like the heart or ... of CT is its ability to image bone, soft tissue and blood vessels all at the same time. Unlike conventional x-rays, CT scanning provides very detailed images of many ...

  7. Computed Tomography (CT) -- Sinuses

    Medline Plus

    Full Text Available ... image recording plate. Bones appear white on the x-ray; soft tissue, such as organs like the heart or ... of CT is its ability to image bone, soft tissue and blood vessels all at the same time. Unlike conventional x-rays, CT scanning provides very detailed images of many ...

  8. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... detailed images of many types of tissue as well as the lungs, bones, and blood vessels. 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 ...

  9. Computed Tomography (CT) -- Sinuses

    Medline Plus

    Full Text Available ... detailed images of many types of tissue as well as the lungs, bones, and blood vessels. 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 ...

  10. CT of Gastric Emergencies.

    Science.gov (United States)

    Guniganti, Preethi; Bradenham, Courtney H; Raptis, Constantine; Menias, Christine O; Mellnick, Vincent M

    2015-01-01

    Abdominal pain, nausea, and vomiting are common presenting symptoms among adult patients seeking care in the emergency department, and, with the increased use of computed tomography (CT) to image patients with these complaints, radiologists will more frequently encounter a variety of emergent gastric pathologic conditions on CT studies. Familiarity with the CT appearance of emergent gastric conditions is important, as the clinical presentation is often nonspecific and the radiologist may be the first to recognize gastric disease as the cause of a patient's symptoms. Although endoscopy and barium fluoroscopy remain important tools for evaluating patients with suspected gastric disease in the outpatient setting, compared with CT these modalities enable less comprehensive evaluation of patients with nonspecific complaints and are less readily available in the acute setting. Endoscopy is also more invasive than CT and has greater potential risks. Although the mucosal detail of CT is relatively poor compared with barium fluoroscopy or endoscopy, CT can be used with the appropriate imaging protocols to identify inflammatory conditions of the stomach ranging from gastritis to peptic ulcer disease. In addition, CT can readily demonstrate the various complications of gastric disease, including perforation, obstruction, and hemorrhage, which may direct further clinical, endoscopic, or surgical management. We will review the normal anatomy of the stomach and discuss emergent gastric disease with a focus on the usual clinical presentation, typical imaging appearance, and differentiating features, as well as potential imaging pitfalls.

  11. Circular law for random discrete matrices of given row sum

    CERN Document Server

    Nguyen, Hoi H

    2012-01-01

    Let $M_n$ be a random matrix of size $n\\times n$ and let $\\lambda_1,...,\\lambda_n$ be the eigenvalues of $M_n$. The empirical spectral distribution $\\mu_{M_n}$ of $M_n$ is defined as $$\\mu_{M_n}(s,t)=\\frac{1}{n}# \\{k\\le n, \\Re(\\lambda_k)\\le s; \\Im(\\lambda_k)\\le t\\}.$$ The circular law theorem in random matrix theory asserts that if the entries of $M_n$ are i.i.d. copies of a random variable with mean zero and variance $\\sigma^2$, then the empirical spectral distribution of the normalized matrix $\\frac{1}{\\sigma\\sqrt{n}}M_n$ of $M_n$ converges almost surely to the uniform distribution $\\mu_\\cir$ over the unit disk as $n$ tends to infinity. In this paper we show that the empirical spectral distribution of the normalized matrix of $M_n$, a random matrix whose rows are independent random $(-1,1)$ vectors of given row-sum $s$ with some fixed integer $s$ satisfying $|s|\\le (1-o(1))n$, also obeys the circular law. The key ingredient is a new polynomial estimate on the least singular value of $M_n$.

  12. Urbanization: the pipelines ROW (Right-of-Way) future

    Energy Technology Data Exchange (ETDEWEB)

    Ribeiro, Gilberto; Malzone, Vivian de Araujo Oliveira [TRANSPETRO - PETROBRAS Transporte S.A., Rio de Janeiro, RJ (Brazil)

    2009-07-01

    The accelerated process of urbanization that is shifting the aspects of Brazilian cities - most clearly in South East and South region states - is inherently involved with decayed levels of quality of life and little or any concern at all with the sustainability of such urban expansion. Besides the social difficulties generated from this non-planned growth - mainly in the cities' outskirts - there are many questions related to urbanization that should be reconsidered such as water, soil and air pollution; lack of water resources; floods, insufficient public transport and traffic problems; urban infra-structure and lodging privations and inadequate soil installment. This paper aims at showing how this disordered urban growth plays an important role on PETROBRAS' pipeline right of way located at the great cities urban areas, more specifically the Urban Right Of Way that cross the metropolitan region of the city of Sao Paulo. Also, it is an objective to express how such urbanization propitiate the execution of basic infra-structure in a way of integrating habitation, sanitation, environment and geotechnical sectors with the purposes of PETROBRAS of maintaining as priority the integrity of the pipelines located on the ROW as well as the integrity of these ROW themselves. (author)

  13. Development of Magnetorheological Resistive Exercise Device for Rowing Machine

    Science.gov (United States)

    Žiliukas, Pranas

    2016-01-01

    Training equipment used by professional sportsmen has a great impact on their sport performance. Most universal exercisers may help only to improve the general physical condition due to the specific kinematics and peculiar resistance generated by their loading units. Training of effective techniques and learning of psychomotor skills are possible only when exercisers conform to the movements and resistance typical for particular sports kinematically and dynamically. Methodology of developing a magnetorheological resistive exercise device for generating the desired law of passive resistance force and its application in a lever-type rowing machine are described in the paper. The structural parameters of a controllable hydraulic cylinder type device were found by means of the computational fluid dynamics simulation performed by ANSYS CFX software. Parameters describing the magnetorheological fluid as non-Newtonian were determined by combining numerical and experimental research of the resistance force generated by the original magnetorheological damper. A structural scheme of the device control system was developed and the variation of the strength of magnetic field that affects the magnetorheological fluid circulating in the device was determined, ensuring a variation of the resistance force on the oar handle adequate for the resistance that occurs during a real boat rowing stroke. PMID:27293479

  14. Mastering Energy Management During Rowing Using Virtual Reality

    Directory of Open Access Journals (Sweden)

    Verbrugge Luc

    2011-12-01

    Full Text Available This study focused on one of the most important factors in rowing performance which is the ability demonstrated by elite rowers to regulate their effort during a 2000m race in order to produce their best performance. Experts are known to adopt a particular pacing strategy with a fast-start profile. The purpose of our study was to test by using virtual reality whether novice rowers were able to acquire this energy management skill during a 2000m race, with positive consequences for their rowing performance. Participants from the Avatar group were instructed to track a virtual boat, which velocity was previously calibrated to follow the appropriate to-be-learned velocity profile. This group was contrasted with a control group, which followed a classic training procedure. Our results indicate that the avatar group improved its performance (decrease in race duration, learned and maintained the expert profile. These effects were absent in the control group. Together, these results indicate that virtual reality can be used to accelerate the learning of energy-related skills.

  15. Development of Magnetorheological Resistive Exercise Device for Rowing Machine

    Directory of Open Access Journals (Sweden)

    Vytautas Grigas

    2016-01-01

    Full Text Available Training equipment used by professional sportsmen has a great impact on their sport performance. Most universal exercisers may help only to improve the general physical condition due to the specific kinematics and peculiar resistance generated by their loading units. Training of effective techniques and learning of psychomotor skills are possible only when exercisers conform to the movements and resistance typical for particular sports kinematically and dynamically. Methodology of developing a magnetorheological resistive exercise device for generating the desired law of passive resistance force and its application in a lever-type rowing machine are described in the paper. The structural parameters of a controllable hydraulic cylinder type device were found by means of the computational fluid dynamics simulation performed by ANSYS CFX software. Parameters describing the magnetorheological fluid as non-Newtonian were determined by combining numerical and experimental research of the resistance force generated by the original magnetorheological damper. A structural scheme of the device control system was developed and the variation of the strength of magnetic field that affects the magnetorheological fluid circulating in the device was determined, ensuring a variation of the resistance force on the oar handle adequate for the resistance that occurs during a real boat rowing stroke.

  16. Development of Magnetorheological Resistive Exercise Device for Rowing Machine.

    Science.gov (United States)

    Grigas, Vytautas; Šulginas, Anatolijus; Žiliukas, Pranas

    2015-01-01

    Training equipment used by professional sportsmen has a great impact on their sport performance. Most universal exercisers may help only to improve the general physical condition due to the specific kinematics and peculiar resistance generated by their loading units. Training of effective techniques and learning of psychomotor skills are possible only when exercisers conform to the movements and resistance typical for particular sports kinematically and dynamically. Methodology of developing a magnetorheological resistive exercise device for generating the desired law of passive resistance force and its application in a lever-type rowing machine are described in the paper. The structural parameters of a controllable hydraulic cylinder type device were found by means of the computational fluid dynamics simulation performed by ANSYS CFX software. Parameters describing the magnetorheological fluid as non-Newtonian were determined by combining numerical and experimental research of the resistance force generated by the original magnetorheological damper. A structural scheme of the device control system was developed and the variation of the strength of magnetic field that affects the magnetorheological fluid circulating in the device was determined, ensuring a variation of the resistance force on the oar handle adequate for the resistance that occurs during a real boat rowing stroke. PMID:27293479

  17. Rowing, the ultimate challenge to the human body - implications for physiological variables

    DEFF Research Database (Denmark)

    Volianitis, S.; Secher, Niels H.

    2009-01-01

    Clinical diagnoses depend on a variety of physiological variables but the full range of these variables is seldom known. With the load placed on the human body during competitive rowing, the physiological range for several variables is illustrated. The extreme work produced during rowing is expla......Clinical diagnoses depend on a variety of physiological variables but the full range of these variables is seldom known. With the load placed on the human body during competitive rowing, the physiological range for several variables is illustrated. The extreme work produced during rowing...

  18. Muscle Synergies of Untrained Subjects during 6 min Maximal Rowing on Slides and Fixed Ergometer

    Directory of Open Access Journals (Sweden)

    Shazlin Shaharudin

    2014-12-01

    Full Text Available 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.

  19. Essential oil and composition of anise (pimpinella anisum l.) with varying seed rates and row spacing

    International Nuclear Information System (INIS)

    Two year study was carried out to explore the effect of seed rate and row spacing on the fruit yield, essential oil yield and composition of aniseed. The study factors included seed rate (6 g, 12 g, 24 g/10 m2) and row spacing (15 cm, 25 cm, 37.5 cm. A significantly higher fruit yield was produced at narrow row spacing of 15 cm among treatments. Wider row spacing produced markedly higher essential oil than narrow row spacing. Essential oil accumulation decreased as planting densities increased. The major constituent of anise oil was trans-anethole (82.1%) followed by himachalene (7.0%). The quality parameters including estragol, himachalene and trans-anethole were significantly affected by different row spacing. Plant grown at 37.5 cm row spacing accumulated the highest estragol and trans-anethole concentration among the row spacing treatments. It can be concluded that higher plant density and wider row spacing increased the disease infestation and lodging cultivar Enza Zaden in current study exhibited high concentration trans-anethole in essential oil composition therefore is a good quality chemotype. (author)

  20. Effects of Row-Spacing on Canopy Structure and Yield in Different Plant Type Rice Cultivars

    Institute of Scientific and Technical Information of China (English)

    Zhao Hai-xin; Wang Xiao-xue; Guo Zhen-hua; Huang Xiao-qun; Liu Hua-long

    2012-01-01

    Two japonica rice varieties, Longjing 20 (more tillers and curved panicle type, MCP) and Longjing 21 (few tillers and half erect panicle type, FEP), were used to study the effects of row-spacing on canopy structure, morphological characteristics and yield. The results showed that the percentage of productive tiller reduced first, and increased afterwards as row-spacing increasing. The relationship between row spacing and the percentage of productive tiller fitted a quadratic regression. The effects of row spacing on leaf area index (LAI) at later tillering stage and the highest stem number per square meter also followed a quadratic regression relationship with increasing first and then reducing. The effects of row-spacing on primary branch were larger than the secondary branch in Longjing 20. However, the trend in Longjing 21 was opposite. The relationship between row spacing and seed setting rate of the secondary branch or panicle was negatively correlated. An extreme significant negative correlation was obtained between seed setting rate of secondary branch in Longjing 20. There was no significant positive correlation between row-spacing and yield in Longjing 20 (R2=0.68). However, the negative correlation between row-spacing and yield of Longjing 21 was extremely significant (R2=–0.96**). The canopy structure of MCP was more sensitive to row-spacing. The positive correlation between row spacing and the length of the flag leaf (R2=0.89**), the width of the flag leaf (R2=0.85*), the length of the last internode (R2=0.85*), the length of the last 2nd internode (R2=0.96**) or the length of the panicle (R2=0.91**) was significant or extremely significant in Longjing 20, but not in Longjing 21. The wider row-spacing promoted the accumulation of the dry matter of panicle, stem and leaf and the yield formation in MCP. The best row-spacing in Longjing 20 was 30 cm. For Longjing 21, the narrower row-spacing was better. The best row-spacing of it was 21 cm. These results

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

    Medline Plus

    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. CT imaging provides real-time imaging, making it ...

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

    NARCIS (Netherlands)

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

    2007-01-01

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

  3. CT of tracheal agenesis

    International Nuclear Information System (INIS)

    Tracheal agenesis is a rare and usually lethal anomaly. In the past, opaque contrast medium was injected via the esophagus to demonstrate the anatomy. To demonstrate the utility of helical and multidetector CT in delineating the aberrant anatomy in newborns with tracheal agenesis. Four newborns with tracheal agenesis were identified from three institutions. Imaging studies and medical records were reviewed. Each child was imaged with chest radiography. One child was imaged on a single-detector helical CT scanner and the other three on multidetector scanners. Helical and multidetector CT with 2D and 3D reconstructions clearly delineated the aberrant tracheobronchial and esophageal anatomy in each infant. Minimum intensity projection reformatted CT images were particularly helpful. One infant each had type I and type II tracheal agenesis. Two infants had type III tracheal agenesis. All four infants died. CT is a useful tool for delineating the aberrant anatomy of newborns with tracheal agenesis and thus helps in making rational clinical decisions. (orig.)

  4. CT of tracheal agenesis

    Energy Technology Data Exchange (ETDEWEB)

    Strouse, Peter J.; Hernandez, Ramiro J. [C.S. Mott Children' s Hospital, Department of Radiology, Ann Arbor, MI (United States); Newman, Beverley [Children' s Hospital of Pittsburgh, PA (United States). Department of Pediatric Radiology; Afshani, Ehsan [Children' s Hospital of Buffalo, NY (United States). Departments of Radiology and Pediatrics; Bommaraju, Mahesh [Women' s and Children' s Hospital of Buffalo, Division of Neonatology, University Pediatrics Associates, Buffalo, NY (United States)

    2006-09-15

    Tracheal agenesis is a rare and usually lethal anomaly. In the past, opaque contrast medium was injected via the esophagus to demonstrate the anatomy. To demonstrate the utility of helical and multidetector CT in delineating the aberrant anatomy in newborns with tracheal agenesis. Four newborns with tracheal agenesis were identified from three institutions. Imaging studies and medical records were reviewed. Each child was imaged with chest radiography. One child was imaged on a single-detector helical CT scanner and the other three on multidetector scanners. Helical and multidetector CT with 2D and 3D reconstructions clearly delineated the aberrant tracheobronchial and esophageal anatomy in each infant. Minimum intensity projection reformatted CT images were particularly helpful. One infant each had type I and type II tracheal agenesis. Two infants had type III tracheal agenesis. All four infants died. CT is a useful tool for delineating the aberrant anatomy of newborns with tracheal agenesis and thus helps in making rational clinical decisions. (orig.)

  5. Biomechanical comparison of double-row versus transtendon single-row suture anchor technique for repair of the grade Ⅲ partial articular-sided rotator cuff tears

    Institute of Scientific and Technical Information of China (English)

    ZHANG Chun-gang; ZHAO De-wei; WANG Wei-ming; REN Ming-fa; LI Rui-xin; YANG Sheng; LIU Yu-peng

    2010-01-01

    Background For partial-thickness tears of the rotator cuff, double-row fixation and transtendon single-row fixation restore insertion site anatomy, with excellent results. We compared the biomechanical properties of double-row and transtendon single-row suture anchor techniques for repair of grade Ⅲ partial articular-sided rotator cuff tears.Methods In 10 matched pairs of fresh-frozen sheep shoulders, the infraspinatus tendon from 1 shoulder was repaired with a double-row suture anchor technique. This comprised placement of 2 medial anchors with horizontal mattress sutures at an angle of .≤45° into the medial margin of the infraspinatus footprint, just lateral to the articular surface, and 2 lateral anchors with horizontal mattress sutures. Standardized, 50% partial, articular-sided infraspinatus lesions were created in the contralateral shoulder. The infraspinatus tendon from the contralateral shoulder was repaired using two anchors with transtendon single-row mattress sutures. Each specimen underwent cyclic loading from 10 to 100 N for 50 cycles, followed by tensile testing to failure. Gap formation and strain over the footprint area were measured using a motion capture system; stiffness and failure load were determined from testing data.Results Gap formation for the transtendon single-row repair was significantly smaller (P <0.05) when compared with the double-row repair for the first cycle ((1.74±0.38) mm vs. (2.86±0.46) mm, respectively) and the last cycle ((3.77±0.45) mm vs. (5.89±0.61) mm, respectively). The strain over the footprint area for the transtendon single-row repair was significantly smaller (P <0.05) when compared with the double-row repair. Also, it had a higher mean ultimate tensile load and stiffness.Conclusions For grade Ⅲ partial articular-sided rotator cuff tears, transtendon single-row fixation exhibited superior biomechanical properties when compared with double-row fixation.

  6. 多层螺旋CT低剂量CTA评价大脑动脉的可行性%Feasibility of low-dose cerebral CT angiography

    Institute of Scientific and Technical Information of China (English)

    方林; 王秋霞; 陈世贵

    2014-01-01

    Objective To assess the feasibility of low-dose cerebral CT angiography(CTA).Methods From August 2012 through June 2013,62 patients who underwent 64-detector-row CTA were randomly divided to two groups using conventional method of 120 kV and 80 mL of intravenous Iohexol(17 men,14 women,age range:37-76 years,median:63 years,body weight:40-71 kg)or low-dose method of 80 kV and 50 mL of intravenous Iohexol followed by 30 mL of normal saline(16 men,15 women,age range:36-74 years,median:59 years,body weight:38-73 kg).The CT values of the M1 segments of the middle cerebral arteries(MCA), basilar arteries,noise and signal-to-noise ratios on the axial images were determined.The quality of the circles of Willis on the 3 D volume rendered images was scored.The radiation dose indexes including CTDIvol and DLP were recorded.Results The CT values of the M1 segments of MCA and basilar arteries were significantly(P<0.05)higher using the low-dose method(307.19,306.38)than those of conventional method(303.01,302.25).The noise was lower and the image quality scores of the circles of Willis were higher with the low-dose method as well.Conclusion Low-dose cerebral CTA improves the image quality and significantly decrease the dose of radiation and iodinated contrast.%目的:探讨64层MSCT 80 kV扫描使用低剂量对比剂的CTA评价大脑动脉的可行性。方法2012年8月~2013年6月间住院拟做大脑动脉检查的患者62例,随机分成Ⅰ组(使用120 kV CT扫描和注射80 ml碘海醇)和Ⅱ组(使用80 kV CT扫描和注射50 ml碘海醇加30 ml生理盐水)。其中Ⅰ组31例(男17例,女14例,年龄37~76岁,中位年龄63岁,体重40~71 kg),Ⅱ组31例(男16例,女15例,年龄36~74岁,中位年龄59岁,体重38~73 kg)。扫描后测量CTA图像中大脑中动脉M1段及基底动脉内的CT值、横轴位图像噪声及信噪比,并对大脑Willis环的VR三维图像进行3级评分;记录辐射剂量指标CTDIvol

  7. Row Spacing in Relation to Competition for Limited Resources in Soybean (Glycine Max L.Merrill)

    Institute of Scientific and Technical Information of China (English)

    LIU Xiao-bing; S J Herbert; JIN Jian; M Hashemi; WANG Guang-hua

    2004-01-01

    Growing soybeans in different row-spacings introduces competition. Competition begins when the immediate supply of a single necessary factor falls below the combined demands of all plants. This paper reviews the main competition factors of genotypes, light, water, nutrients and weed in responses to row spacings for the past four decades. It demonstrated that responses of soybean genotypes to row width differ among cultivars, which depend on seasonal rainfall and irrigation. Determinate types produce more yield in narrow-rows, and cultivars with lodging resistance should be adopted in narrow-spacings, but indeterminate soybean should also be used to optimize yields in certain system. Narrow-compared with wide-row soybean (Glycine max) cultivation increases light interception (LI) and dominant components for the increase come from LAI, light extinction coefficients and branch types. Water use efficiency (WUE) and evapotranspiration are not influenced by row spacing, but seed yield could be increased if irrigation is applied. Nutrient uptake is significantly affected by row spacing, seed yields and uptake of N, P, K in plants increases with decreasing row spacing, and the effects depend on the fertilizer levels. Other factors rather than row spacing affect nitrogen fixation. Weed density, peak time and periodicity of weed emergence are not affected by row spacing, but better complementary weed control by the herbicides at the used doses can be obtained in narrow spacing due to the reduced weed number and dry weight. More researches are required to investigate the physiological responses, nutrient and water uptake and translocation, light utilization at different layers of canopy and soil environment changes in different row-spacings.

  8. CT in alveolar proteinosis

    International Nuclear Information System (INIS)

    Nine patients with pulmonary alveolar proteinosis (PAP) were scanned with CT. Results were not specific for PAP but may be help0ful in the differential diagnosis is visualization of pulmonary vessels is maintained and air bronchograms are scarce in diseased areas. CT is better than conventional radiography in identifying infectious complications and evaluating disease extent and may help in deciding whether or not therapeutic lavage is indicated. CT has also identified an interstitial component of PAP that correlates histologically with an inflammatory cell infiltrate. The cellular infiltrate may play a role in the development of the interstitial fibrosis seen in some cases of PAP

  9. Comparison of digital subtraction angiography, CT angiography, and ultrasonic doppler examination in the evaluation of penile arterial lesions

    Energy Technology Data Exchange (ETDEWEB)

    Kawanisi, Yasuo; Kimura, Kazunori; Lee, Kyong Soo; Koizumi, Takahiro; Nakatsuji, Hiroyoshi; Kojima, Keiji; Yamamoto, Akira; Numata, Akira [Takamatsu Red Cross Hospital (Japan)

    2001-11-01

    CT angiography reconstructed by a multidetector-row helical CT scanner is a newly developed form of imaging. We compared CT angiography and ultrasonic Doppler examination with digital subtraction angiography (DSA) in the diagnosis of arterial lesion. Eighteen patients with arteriogenic erectile dysfunction (ED) underwent color Doppler study DSA, and CT angiography after providing informed consent. The CT angiography images were obtained by a multidetector-row helical CT scanner, Asteion TSX021A (TOSHIBA). We injected prostaglandin E{sub 1} into the penile cavernous body, and then rapidly infused nonionic contrast medium into the antecubital vein. DSA and CT angiography images of the bilateral internal pudendal arteries and cavernous arteries were examined for stenotic lesions or occlusion. We also compared the peak systolic blood flow velocity in the cavernous artery measured by color Doppler ultrasound with CT angiography and DSA. The CT anigography and color Doppler studies were performed on an outpatient basis, but DSA required hospitalization. In the 36 internal pudendal arteries, DSA represented 22 normal arteries and 14 stenosis or occlusions. CT angiography showed 15 normal arteries and 21 occlusions. For the diagnosis of stenosis or occlusion in the internal pudendal artery, the CT angiography image had a good agreement, with a sensitivity of 1.00, specificity of 0.68, and accuracy of 0.81. For diagnosis in the cavernous artery, CT angiography image also showed a good agreement with DSA; however, the quality of the images of fine arteries was better in the DSA images. The inferior view and internal view of the pelvis in CT angiography were helpful for visulaizing the internal pudendal artery, especially at the pubic bone. There was insufficient correlation between peak systolic blood flow velocity and DSA findings. There were no serious complications involved in either examination. CT angiography has not yet reached the same level as DSA in the evaluation

  10. MOTION CAPTURE AS A MODERN TECHNOLOGY FOR ANALYSING ERGOMETER ROWING

    Directory of Open Access Journals (Sweden)

    Maria Skublewska-Paszkowska

    2016-03-01

    Full Text Available The paper presents a purpose-built laboratory stand consisting of a Vicon motion capture system with reference video cameras, wireless EMG system, Concept 2 Indoor Rower ergometer, wireless heart rate monitor and the Nexus software. A pilot study of people who exercise on the ergometer helped to create a proper configuration of all the components of the laboratory. Moreover, a procedure for carrying out research was developed, which consists of several steps divided into 4 stages: preparation of the motion acquisition system; preparation of the participant; familiarising participants with the technique of rowing, recording their movements and acquiring other measurement signals. Preliminary analysis of the results obtained from heterogeneous signals from various devices showed that all the components of the research stand are mutually compatible and the received signals do not interfere with one another.

  11. Developmental changing in the form and function of rowing hydromedusae

    Science.gov (United States)

    Colin, S. P.; Weston, J.; Costello, J. H.; Dabiri, J. O.

    2007-12-01

    Among medusan lineages bell morphology and propulsion appear to be interdependent traits. In general, taxa that possess large oblate bells swim via rowing propulsion and taxa with small prolate bells swim via jet propulsion. However, hydromedusae from the order, Leptomedusae, experience large changes in bell size and shape throughout their development, metamorphosing from small prolate juveniles into large oblate adults. To examine how propulsion changes throughout the development of leptomedusae, we investigated the fluid interactions and swimming characteristics of two leptomedusan species, Aequorea victorea and Eutonina indicans, throughout their development. As expected, these species start off as small prolate juveniles ( 1.5 cm diameter). In addition to changes in morphology, we observed changes in Reynolds number, wake structure, propulsion and swimming kinematics. These changes were consistent with the previously described relationship between bell morphology and function.

  12. Response of rainfed chickpea (cicer arietnum L.) to tween row spatial arrangement at multiple densities

    International Nuclear Information System (INIS)

    Plant density and arrangement are important factors affecting rainfed chickpea yield. A field experiment was conducted under the Eastern Mediterranean conditions for two consecutive growing seasons (2009-2010 and 2010-2011) to evaluate the effects of plant density (20, 25, 35 and 55 plants per m 2) and spatial configuration (conventional single 36-cm row width vs 18-cm twin rows spaced 72-cm between paired-rows). The experiment was laid out in a randomized complete block design in a factorial arrangement with three replications. Light interception (LI) and leaf area index (LAI) were significantly affected by plant density. Twin-row arrangement had higher light interception efficiency (LIE) than the single-row. Plants grown in the higher plant densities had greater LAI and LI; however, they had inefficient use of incident solar radiation. The number of primary branches was significantly affected by both planting patterns and plant densities, but the number of secondary branches was significantly affected only by the plant densities. The number of pods and seeds/plant decreased with the increasing plant density. The highest seed weight/plant was recorded at the lowest density (20 plants/m2) while the lowest one was recorded at the highest plant density (55 plants/m2). Seed weight and harvest index in the twin row were significantly higher in tween row than in the single row. (author)

  13. Building Generalized Inverses of Matrices Using Only Row and Column Operations

    Science.gov (United States)

    Stuart, Jeffrey

    2010-01-01

    Most students complete their first and only course in linear algebra with the understanding that a real, square matrix "A" has an inverse if and only if "rref"("A"), the reduced row echelon form of "A", is the identity matrix I[subscript n]. That is, if they apply elementary row operations via the Gauss-Jordan algorithm to the partitioned matrix…

  14. Plastic Mulches and Row Covers on the grow and production of Summer Squash.

    Science.gov (United States)

    Summer squash [Cucurbita pepo (L) ‘Prelude II’] was grown on an Orangeburg sandy loam soil in Shorter, AL. The summer squash was direct seeded in single rows. The experiment consisted of twelve experimental treatments as follows: (1) Black plastic mulch (BPM) + spunbonded row cover (RC), (2) BPM, (...

  15. The effects of color plastic mulches and row covers on the growth and yield of okra

    Science.gov (United States)

    Okra [Abelmoschus esculentus (l.) Moench'Clemson Spineless'] was grown on an Orangeburg sandy loam soil in shorter, AL. Okra was direct seeded in single rows. The experiment consisted of twelve experimental treatments as follows: (1) Black plastic mulch (BPM) + spunbonded row cover (RC), (2) BPM, (3...

  16. Row Reduction Applied to Decoding of Rank Metric and Subspace Codes

    DEFF Research Database (Denmark)

    Puchinger, Sven; Nielsen, Johan Sebastian Rosenkilde; Li, Wenhui;

    2016-01-01

    We show that decoding of ℓ-Interleaved Gabidulin codes, as well as list-ℓ decoding of Mahdavifar–Vardy (MV) codes can be performed by row reducing skew polynomial matrices. Inspired by row reduction of F[x] matrices, we develop a general and flexible approach of transforming matrices over skew po...

  17. Effects of an Aerobic Rowing Training Regimen in Young Adults with Down Syndrome.

    Science.gov (United States)

    Varela, Ana Maria; Sardinha, Luis Bettencount; Pitetti, Kenneth H.

    2001-01-01

    Eight young adult males with Down syndrome received a 16-week rowing ergometry training regimen. Following training, no changes in cardiovascular fitness were found but participants did achieve significantly higher levels of work performance on both treadmill and rowing ergometer tests than did a control group. (Contains references.) (Author/DB)

  18. STS-42 Commander Grabe uses DTO 653 MK1 Rowing Machine on OV-103's middeck

    Science.gov (United States)

    1992-01-01

    STS-42 Commander Ronald J. Grabe exercises using MK1 Rowing Machine on the middeck of Discovery, Orbiter Vehicle (OV) 103. Grabe is using the exercise device as part of Development Test Objective (DTO) 653, Evaluation of MK1 Rowing Machine. The forward lockers appear at Grabe's right and the sleep station behind him.

  19. Transfer of complex skill learning from virtual to real rowing.

    Directory of Open Access Journals (Sweden)

    Georg Rauter

    Full Text Available Simulators are commonly used to train complex tasks. In particular, simulators are applied to train dangerous tasks, to save costs, and to investigate the impact of different factors on task performance. However, in most cases, the transfer of simulator training to the real task has not been investigated. Without a proof for successful skill transfer, simulators might not be helpful at all or even counter-productive for learning the real task. In this paper, the skill transfer of complex technical aspects trained on a scull rowing simulator to sculling on water was investigated. We assume if a simulator provides high fidelity rendering of the interactions with the environment even without augmented feedback, training on such a realistic simulator would allow similar skill gains as training in the real environment. These learned skills were expected to transfer to the real environment. Two groups of four recreational rowers participated. One group trained on water, the other group trained on a simulator. Within two weeks, both groups performed four training sessions with the same licensed rowing trainer. The development in performance was assessed by quantitative biomechanical performance measures and by a qualitative video evaluation of an independent, blinded trainer. In general, both groups could improve their performance on water. The used biomechanical measures seem to allow only a limited insight into the rowers' development, while the independent trainer could also rate the rowers' overall impression. The simulator quality and naturalism was confirmed by the participants in a questionnaire. In conclusion, realistic simulator training fostered skill gains to a similar extent as training in the real environment and enabled skill transfer to the real environment. In combination with augmented feedback, simulator training can be further exploited to foster motor learning even to a higher extent, which is subject to future work.

  20. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... microphone. top of page How does the procedure work? In many ways CT scanning works very much ... the best way to see if treatment is working or if an abnormality is stable or changed ...

  1. Computed Tomography (CT) -- Sinuses

    Medline Plus

    Full Text Available ... microphone. top of page How does the procedure work? In many ways CT scanning works very much ... the best way to see if treatment is working or if an abnormality is stable or changed ...

  2. Computed Tomography (CT) -- Head

    Science.gov (United States)

    ... the head is typically used to detect: bleeding, brain injury and skull fractures in patients with head injuries. ... medically necessary because of potential risk to the baby. This risk is, however, minimal with head CT ...

  3. Computed Tomography (CT) -- Sinuses

    Medline Plus

    Full Text Available ... up in shades of gray, and air appears black. With CT scanning, numerous x-ray beams and ... be removed by the technologist, and the tiny hole made by the needle will be covered with ...

  4. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... up in shades of gray, and air appears black. With CT scanning, numerous x-ray beams and ... be removed by the technologist, and the tiny hole made by the needle will be covered with ...

  5. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... resulting in more detail and additional view capabilities. Modern CT scanners are so fast that they can ... the scanning. Any motion, whether breathing or body movements, can lead to artifacts on the images. This ...

  6. Computed Tomography (CT) -- Sinuses

    Medline Plus

    Full Text Available ... resulting in more detail and additional view capabilities. Modern CT scanners are so fast that they can ... the scanning. Any motion, whether breathing or body movements, can lead to artifacts on the images. This ...

  7. Computed Tomography (CT) -- Head

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    Full Text Available ... Videos related to Computed Tomography (CT) - Head About this Site RadiologyInfo.org is produced by: Please note ... you can search the ACR-accredited facilities database . This website does not provide cost information. The costs ...

  8. Computed Tomography (CT) -- Sinuses

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    Full Text Available ... Images related to Computed Tomography (CT) - Sinuses About this Site RadiologyInfo.org is produced by: Please note ... you can search the ACR-accredited facilities database . This website does not provide cost information. The costs ...

  9. Computed Tomography (CT) -- Head

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    Full Text Available ... See the Safety page for more information about pregnancy and x-rays. top of page What does ... See the Safety page for more information about pregnancy and x-rays. CT scanning is, in general, ...

  10. Computed Tomography (CT) -- Sinuses

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    Full Text Available ... See the Safety page for more information about pregnancy and x-rays. top of page What does ... See the Safety page for more information about pregnancy and x-rays. CT scanning is, in general, ...

  11. CT head in children

    Energy Technology Data Exchange (ETDEWEB)

    Rao, Padma, E-mail: padma.rao@rch.org.au [Royal Children' s Hospital and the University of Melbourne, Medical Imaging Department, Flemington Road, Parkville, Melbourne, Victoria 3052 (Australia); Bekhit, Elhamy, E-mail: elhamy.bekhit@rch.org.au [Royal Children' s Hospital and the University of Melbourne, Medical Imaging Department, Flemington Road, Parkville, Melbourne, Victoria 3052 (Australia); Ramanauskas, Fiona, E-mail: fiona.ramanauskas@rch.org.au [Royal Children' s Hospital and the University of Melbourne, Medical Imaging Department, Flemington Road, Parkville, Melbourne, Victoria 3052 (Australia); Kumbla, Surekha, E-mail: surekha.kumbla@rch.org.au [Royal Children' s Hospital and the University of Melbourne, Medical Imaging Department, Flemington Road, Parkville, Melbourne, Victoria 3052 (Australia)

    2013-07-15

    The advances in computerized technology (CT) technique over the last few decades have greatly modified imaging protocols in children. The range of pathologies that can now be demonstrated has broadened with the advent of newer techniques such as CT perfusion and the ability to perform complex reconstructions. Increasing speed of scanning and reduction in scan time have influenced the need for sedation and general anaesthetic as well as impacting on motion artefact. Additionally, concerns about radiation safety and avoidance of unnecessary radiation have further impacted on the inclusion of CT in the imaging armamentarium. Justification and image optimisation are essential. It is important to familiarize oneself with the appearances of normal variants or age related developmental changes. CT does however remain an appropriate investigation in a number of conditions.

  12. Computed Tomography (CT) -- Sinuses

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    Full Text Available ... artifacts on the images. This loss of image quality can resemble the blurring seen on a photograph ... verifies that the images are of high enough quality for accurate interpretation. The actual CT scan takes ...

  13. Pediatric CT Scans

    Science.gov (United States)

    The Radiation Epidemiology Branch and collaborators have initiated a retrospective cohort study to evaluate the relationship between radiation exposure from CT scans conducted during childhood and adolescence and the subsequent development of cancer.

  14. CT urography and hematuria

    DEFF Research Database (Denmark)

    Bretlau, Thomas; Hansen, Rasmus H; Thomsen, Henrik S

    2015-01-01

    BACKGROUND: Computed tomography (CT) urography is now used in the work-up of patients with hematuria. The dose of contrast medium and radiation varies considerably between the different CT protocols. PURPOSE: To study the disease prevalence in a consecutive group of patients with hematuria...... undergoing CT urography with a low dose of contrast medium and radiation. MATERIAL AND METHODS: From 1 April 2007 to 31 March 2008, using the Radiological Information System (RIS) as well as electronic patient records, demographic data, reason for referral, and diagnosis were obtained for all patients...... undergoing CT urography due to hematuria. The patients were followed for 3 years. RESULTS: A total of 771 patients had hematuria diagnosed at the time of referral. In 137 patients (18%), a tumor and / or a complex cyst was found in the urinary tract (renal, ureteral, or bladder), in 68 (9%) a calculi, in 118...

  15. Computed Tomography (CT) -- Head

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    Full Text Available ... CT exam to be stressful. The technologist or nurse, under the direction of a physician, may offer ... and send an official report to your primary care physician or physician who referred you for the ...

  16. Computed Tomography (CT) -- Sinuses

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    Full Text Available ... visibility of certain tissues or blood vessels. A nurse or technologist will insert an intravenous (IV) line ... CT exam to be stressful. The technologist or nurse, under the direction of a physician, may offer ...

  17. Computed Tomography (CT) -- Head

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    Full Text Available ... CD or DVD. CT images of internal organs, bones, soft tissue and blood vessels typically provide greater ... is also performed to: evaluate the extent of bone and soft tissue damage in patients with facial ...

  18. Computed Tomography (CT) -- Head

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    Full Text Available ... seconds, and even faster in small children. Such speed is beneficial for all patients but especially children, ... When you enter the CT scanner room, special light lines may be seen projected onto your body, ...

  19. Computed Tomography (CT) -- Sinuses

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    Full Text Available ... seconds, and even faster in small children. Such speed is beneficial for all patients but especially children, ... When you enter the CT scanner room, special light lines may be seen projected onto your body, ...

  20. Computed Tomography (CT) -- Sinuses

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    Full Text Available ... its ability to image bone, soft tissue and blood vessels all at the same time. Unlike conventional x-rays, CT scanning provides very detailed images of many types of tissue as well as the lungs, bones, ...

  1. Computed Tomography (CT) -- Head

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    Full Text Available ... its ability to image bone, soft tissue and blood vessels all at the same time. Unlike conventional x-rays, CT scanning provides very detailed images of many types of tissue as well as the lungs, bones, ...

  2. Computed Tomography (CT) -- Head

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    Full Text Available ... hours prior to your exam. Leave jewelry at home and wear loose, comfortable clothing. You may be ... the CT images and should be left at home or removed prior to your exam. You may ...

  3. Computed Tomography (CT) -- Sinuses

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    Full Text Available ... hours prior to your exam. Leave jewelry at home and wear loose, comfortable clothing. You may be ... the CT images and should be left at home or removed prior to your exam. You may ...

  4. Computed Tomography (CT) -- Head

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    Full Text Available ... you are pregnant and discuss any recent illnesses, medical conditions, medications you’re taking, and allergies. You ... a CT or CAT scan, is a diagnostic medical test that, like traditional x-rays, produces multiple ...

  5. Computed Tomography (CT) -- Sinuses

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    Full Text Available ... you are pregnant and discuss any recent illnesses, medical conditions, medications you’re taking, and allergies. You ... a CT or CAT scan, is a diagnostic medical test that, like traditional x-rays, produces multiple ...

  6. Computed Tomography (CT) -- Head

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    Full Text Available ... to plan radiation therapy for brain cancer. In emergency cases, it can reveal internal injuries and bleeding ... vessels. CT examinations are fast and simple; in emergency cases, they can reveal internal injuries and bleeding ...

  7. Computed Tomography (CT) -- Sinuses

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    Full Text Available ... that are filled with fluid or thickened sinus membranes . detect the presence of inflammatory diseases. provide additional ... view of the body's interior. Refinements in detector technology allow nearly all CT scanners to obtain multiple ...

  8. Computed Tomography (CT) -- Sinuses

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    Full Text Available ... by defining anatomy. 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 ...

  9. Computed Tomography (CT) -- Head

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    Full Text Available ... look like? The CT scanner is typically a large, box-like machine with a hole, or short ... spiral path. A special computer program processes this large volume of data to create two-dimensional cross- ...

  10. Computed Tomography (CT) -- Sinuses

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    Full Text Available ... look like? The CT scanner is typically a large, box-like machine with a hole, or short ... spiral path. A special computer program processes this large volume of data to create two-dimensional cross- ...

  11. Computed Tomography (CT) -- Sinuses

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    Full Text Available ... vessels. CT examinations are fast and simple; in emergency cases, they can reveal internal injuries and bleeding ... About Us | Contact Us | FAQ | Privacy | Terms of Use | Links | Site Map Copyright © 2016 Radiological Society of ...

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    Full Text Available Toggle navigation Test/Treatment Patient Type Screening/Wellness Disease/Condition Safety En Español More Info Images/Videos News Physician Resources Professions Site Index A-Z Computed Tomography (CT) - Sinuses ...

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    Full Text Available Toggle navigation Test/Treatment Patient Type Screening/Wellness Disease/Condition Safety En Español More Info Images/Videos News Physician Resources Professions Site Index A-Z Computed Tomography (CT) - Head ...

  14. Computed Tomography (CT) -- Sinuses

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    Full Text Available ... over time. top of page What are the benefits vs. risks? Benefits A CT scan is one of the safest ... cancer from excessive exposure to radiation. However, the benefit of an accurate diagnosis far outweighs the risk. ...

  15. Computed Tomography (CT) -- Head

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    Full Text Available ... over time. top of page What are the benefits vs. risks? Benefits CT scanning is painless, noninvasive and accurate. A ... cancer from excessive exposure to radiation. However, the benefit of an accurate diagnosis far outweighs the risk. ...

  16. Computed Tomography (CT) -- Sinuses

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    Full Text Available ... over time. top of page What are the benefits vs. risks? Benefits A CT scan is one of the safest ... the possible charges you will incur. Web page review process: This Web page is reviewed regularly by ...

  17. Computed Tomography (CT) -- Head

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    Full Text Available ... over time. top of page What are the benefits vs. risks? Benefits CT scanning is painless, noninvasive and accurate. A ... the possible charges you will incur. Web page review process: This Web page is reviewed regularly by ...

  18. Computed Tomography (CT) -- Sinuses

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    Full Text Available ... during the procedure. Metal objects, including jewelry, eyeglasses, dentures and hairpins, may affect the CT images and ... for? Yes No To submit a comment, please complete the following form: Comment: E-mail: Area code: ...

  19. Computed Tomography (CT) -- Head

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    Full Text Available ... during the procedure. Metal objects, including jewelry, eyeglasses, dentures and hairpins, may affect the CT images and ... for? Yes No To submit a comment, please complete the following form: Comment: E-mail: Area code: ...

  20. Computed Tomography (CT) -- Sinuses

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    Full Text Available ... a relatively short time, especially when compared to magnetic resonance imaging (MRI). CT scanning is painless, noninvasive and ... the extent of soft tissue of the tumor, magnetic resonance imaging (MRI) may be helpful. A person who ...