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Sample records for 128-slice multi-detector ct

  1. An evaluation of the feasibility of assessment of volume perfusion for the whole lung by 128-slice spiral CT

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    Sun, Haitao [Imaging Center of Taian Central Hospital, Taian, Shandong (China); Gao, Fei; Li, Ning; Liu, Cheng [Shandong Univ., Shandong Medical Imaging Research Inst., CT Room, Shandong (China)], e-mail: liucheng491025@sina.com

    2013-10-15

    Background: Lung perfusion based on dynamic scanning cannot provide a quantitative assessment of the whole lung because of the limited coverage of the current computed tomography (CT) detector designs. Purpose: To evaluate the feasibility of dynamic volume perfusion CT (VPCT) of the whole lung using a 128-slice CT for the quantitative assessment and visualization of pulmonary perfusion. Material and Methods: Imaging was performed in a control group of 17 subjects who had no signs of disturbance of pulmonary function or diffuse lung disease, and 15 patients (five patients with acute pulmonary embolism and 10 with emphysema) who constituted the abnormal lung group. Dynamic VPCT was performed in all subjects, and pulmonary blood flow (PBF), pulmonary blood volume (PBV), and mean transit time (MTT) were calculated from dynamic contrast images with a coverage of 20.7 cm. Regional and volumetric PBF, PBV, and MTT were statistically evaluated and comparisons were made between the normal and abnormal lung groups. Results: Regional PBF (94.2{+-}36.5, 161.8 {+-}29.6, 185.7 {+-}38.1 and 125.5 {+-}46.1, 161.9 {+-}31.4, 169.3 {+-}51.7), PBV (6.7 {+-}2.8, 10.9 {+-}3.0, 12.9 {+-}4.5 and 9.9 {+-}4.6, 10.3 {+-}2.9, 11.9 {+-}4.5), and MTT (5.8 {+-}2.4, 4.5 {+-}1.3, 4.7 {+-}2.1 and 5.6 {+-}2.3, 4.3 {+-}1.5, 4.9 {+-}1.5) demonstrated significant differences in the gravitational and isogravitational directions in the normal lung group (P < 0.05). The PBF (154.2 {+-}30.6 vs. 94.9 {+-}15.9) and PBV (11.1 {+-}4.0 vs. 6.6 {+-}1.7) by dynamic VPCT showed significant differences between normal and abnormal lungs (P < 0.05), notwithstanding the four large lungs that had coverage > 20.7 cm. Conclusion: Dynamic VPCT of the whole lung is feasible for the quantitative assessment of pulmonary perfusion by 128-slice CT, and may in future permit the evaluation of both morphological and functional features of the whole lung in a single examination.

  2. Assessments of Coronary Artery Visibility and Radiation Dose in Infants with Congenital Heart Disease on Cardiac 128-slice CT and on Cardiac 64-slice CT.

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    Cui, Y; Huang, M; Zheng, J; Li, J; Liu, H; Liang, C

    2016-01-01

    The aim of this study was to compare the coronary artery visibility and radiation dose in infants with CHD on cardiac 128-slice CT and on cardiac 64-slice CT. The images of 200 patients were analyzed in this study, 100 patients were selected randomly from a group of 789 infants (ECG-triggered axial scan, and 100 were selected randomly from 911 infants with CHD undergoing 64-slice CT retrospective ECG-gated spiral scan. The visibility of coronary artery segments was graded on a four-point scale. The coronary arteries were considered to be detected or visible when grade was 2 or higher. The visibility of the coronary artery segments and the radiation dose was compared between the two groups. Except for the rate of LM (96 vs. 99%), the detection rates of the total, LAD, LCX, RCA, and the proximal segment of the RCA in the 256-slice CT group were significantly higher than those in the 64-slice CT group (51.7, 53.33, 33.67, 53.33, and 99 vs. 34.8, 34.33, 18, 30.67, and 75%, respectively). The counts of visibility score (4/3/2/1) for the LM and the proximal segment of the RCA were 62/22/12/4 and 56/20/17/7, respectively, in the 128-slice CT group and 17/42/30/1 and 9/30/38/25, respectively, in the 64-slice CT group. There were significant differences, especially for score 4 and 3, between the two groups. The radiation dose in the 128-slice CT group was significantly decreased than those in the 64-slice CT group (CTDIvol 1.88 ± 0.51 vs. 5.61 ± 0.63 mGy; SSDE 4.48 ± 1.15 vs. 13.97 ± 1.52 mGy; effective radiation dose 1.36 ± 0.44 vs. 4.06 ± 0.7 mSv). With reduced radiation dose, the visibility of the coronary artery in infants with CHD via prospective ECG-triggered mode on a 128-slice CT is superior to that of the 64-slice CT using retrospective ECG-gated spiral mode. PMID:26271472

  3. Assessments of Coronary Artery Visibility and Radiation Dose in Infants with Congenital Heart Disease on Cardiac 128-slice CT and on Cardiac 64-slice CT.

    Science.gov (United States)

    Cui, Y; Huang, M; Zheng, J; Li, J; Liu, H; Liang, C

    2016-01-01

    The aim of this study was to compare the coronary artery visibility and radiation dose in infants with CHD on cardiac 128-slice CT and on cardiac 64-slice CT. The images of 200 patients were analyzed in this study, 100 patients were selected randomly from a group of 789 infants (coronary artery segments was graded on a four-point scale. The coronary arteries were considered to be detected or visible when grade was 2 or higher. The visibility of the coronary artery segments and the radiation dose was compared between the two groups. Except for the rate of LM (96 vs. 99%), the detection rates of the total, LAD, LCX, RCA, and the proximal segment of the RCA in the 256-slice CT group were significantly higher than those in the 64-slice CT group (51.7, 53.33, 33.67, 53.33, and 99 vs. 34.8, 34.33, 18, 30.67, and 75%, respectively). The counts of visibility score (4/3/2/1) for the LM and the proximal segment of the RCA were 62/22/12/4 and 56/20/17/7, respectively, in the 128-slice CT group and 17/42/30/1 and 9/30/38/25, respectively, in the 64-slice CT group. There were significant differences, especially for score 4 and 3, between the two groups. The radiation dose in the 128-slice CT group was significantly decreased than those in the 64-slice CT group (CTDIvol 1.88 ± 0.51 vs. 5.61 ± 0.63 mGy; SSDE 4.48 ± 1.15 vs. 13.97 ± 1.52 mGy; effective radiation dose 1.36 ± 0.44 vs. 4.06 ± 0.7 mSv). With reduced radiation dose, the visibility of the coronary artery in infants with CHD via prospective ECG-triggered mode on a 128-slice CT is superior to that of the 64-slice CT using retrospective ECG-gated spiral mode.

  4. Estimation of Radiation Exposure of 128-Slice 4D-Perfusion CT for the Assessment of Tumor Vascularity

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    Ketelsen, Dominik; Horger, Marius; Buchgeister, Markus; Fenchel, Michael; Thomas, Christoph; Boehringer, Nadine; Schulze, Maximilian; Tsiflikas, Ilias; Claussen, Claus D.; Heuschmid, Martin [University Hospital Tuebingen, Tuebingen (Germany)

    2010-10-15

    We aimed to estimate the effective dose of 4D-Perfusion-CT protocols of the lung, liver, and pelvis for the assessment of tumor vascularity. An Alderson-Rando phantom equipped with thermoluminescent dosimeters was used to determine the effective dose values of 4D Perfusion-CT. Phantom measurements were performed on a 128-slice single source scanner in adaptive 4D-spiral-mode with bidirectional table movement and a total scan range of 69 mm over a time period of nearly 120 seconds (26 scans). Perfusion measurements were simulated for the lung, liver, and pelvis under the following conditions: lung (80 kV, 60 mAs), liver (80 kV/80 mAs and 80 kV/120 mAs), pelvis (100 kV/80 mAs and 100 kV/120 mAs). Depending on gender, the evaluated body region and scan protocol, an effective whole-body dose between 2.9-12.2 mSv, was determined. The radiation exposure administered to gender-specific organs like the female breast tissue (lung perfusion) or to the ovaries (pelvic perfusion) led to an increase in the female specific dose by 86% and 100% in perfusion scans of the lung and the pelvis, respectively. Due to a significant radiation dose of 4D-perfusion-CT protocols, the responsible use of this new promising technique is mandatory. Gender- and organ-specific differences should be considered for indication and planning of tumor perfusion scans

  5. 128-slice CT angiography of the aorta without ECG-gating: efficacy of faster gantry rotation time and iterative reconstruction in terms of image quality and radiation dose

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    Russo, Vincenzo; Garattoni, Monica; Buia, Francesco; Attina, Domenico; Lovato, Luigi; Zompatori, Maurizio [University Hospital ' ' S.Orsola' ' , Cardio-Thoracic-Vascular Department, Cardio-Thoracic Radiology Unit, Bologna (Italy)

    2016-02-15

    To evaluate image quality and radiation dose of non ECG-gated 128-slice CT angiography of the aorta (CTAA) with fast gantry rotation time and iterative reconstruction. Four hundred and eighty patients underwent non ECG-gated CTAA. Qualitative and quantitative image quality assessments were performed. Radiation dose was assessed and compared with the dose of patients who underwent ECG-gated CTAA (n = 126) and the dose of previous CTAA performed with another CT (n = 339). Image quality (aortic root-ascending portion) was average-to-excellent in more than 94 % of cases, without any non-diagnostic scan. For proximal coronaries, image quality was average-to-excellent in more than 50 %, with only 21.5 % of non-diagnostic cases. Quantitative analysis results were also good. Mean radiation dose for thoracic CTAA was 5.6 mSv versus 20.6 mSv of ECG-gated protocol and 20.6 mSv of 16-slice CTAA scans, with an average dose reduction of 72.8 % (p < 0.001). Mean radiation dose for thoracic-abdominal CTAA was 9.7 mSv, versus 20.9 mSv of 16-slice CTAA scans, with an average dose reduction of 53.6 % (p < 0.001). Non ECG-gated 128-slice CTAA is feasible and able to provide high quality visualization of the entire aorta without significant motion artefacts, together with a considerable dose and contrast media volume reduction. (orig.)

  6. Dual-step prospective ECG-triggered 128-slice dual-source CT for evaluation of coronary arteries and cardiac function without heart rate control: a technical note

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    Feuchtner, Gudrun [University Hospital Zurich, Institute of Diagnostic Radiology, Zurich (Switzerland); Innsbruck Medical University, Department of Radiology II, Innsbruck (Austria); Goetti, Robert; Marincek, Borut; Alkadhi, Hatem; Leschka, Sebastian [University Hospital Zurich, Institute of Diagnostic Radiology, Zurich (Switzerland); Plass, Andre; Wieser, Monika [University Hospital Zurich, Clinic for Cardiovascular Surgery, Zurich (Switzerland); Baumueller, Stephan; Stolzmann, Paul; Scheffel, Hans [University Hospital Zurich, Institute of Diagnostic Radiology, Zurich (Switzerland); University Hospital Zurich, Clinic for Cardiovascular Surgery, Zurich (Switzerland)

    2010-09-15

    To describe prospective ECG-triggered dual-source CT dual-step pulsing (pECG{sub dual-step}) for evaluation of coronary arteries and cardiac function. Fifty-one consecutive patients pre- or post-cardiovascular surgery were examined with adaptive sequential tube current modulated (pECG{sub dual-step}) 128-slice dual-source CT without heart rate control (main padding window: 40% RR interval >65 bpm/70% RR interval <65 bpm). Image quality of coronary arteries was graded (4-point scale), and cardiac function was evaluated. Mean HR was 68 bpm. Thirty-seven patients were in stable sinus rhythm (SR); 14 had arrhythmia. Image quality of coronary arteries was diagnostic in 804/816 (98%) of segments. The number of non-diagnostic segments was higher in patients with arrhythmia as compared to those in SR (4% vs. 0.5%; p = 0.01), and there were fewer segments with excellent image quality (79% vs. 94%; p < 0.001) and more segments with impaired image quality (p < 0.001 and p = 0.002). Global and regional LV function could be evaluated in 41 (80%) and 47 (92%) patients, and valvular function in 48 (94%). In 11/14 of patients with arrhythmia, the second step switched to full mAs, increasing radiation exposure to 8.6 mAs (p < 0.001). The average radiation dose was 3.8 mSv (range, 1.7-7.9) in patients in SR. pECG{sub dual-step}128-slice DSCT is feasible for the evaluation of coronary arteries and cardiac function without heart rate control in patients in stable sinus rhythm at a low radiation dose. (orig.)

  7. 128-slice CT angiography of the aorta without ECG-gating: efficacy of faster gantry rotation time and iterative reconstruction in terms of image quality and radiation dose

    International Nuclear Information System (INIS)

    To evaluate image quality and radiation dose of non ECG-gated 128-slice CT angiography of the aorta (CTAA) with fast gantry rotation time and iterative reconstruction. Four hundred and eighty patients underwent non ECG-gated CTAA. Qualitative and quantitative image quality assessments were performed. Radiation dose was assessed and compared with the dose of patients who underwent ECG-gated CTAA (n = 126) and the dose of previous CTAA performed with another CT (n = 339). Image quality (aortic root-ascending portion) was average-to-excellent in more than 94 % of cases, without any non-diagnostic scan. For proximal coronaries, image quality was average-to-excellent in more than 50 %, with only 21.5 % of non-diagnostic cases. Quantitative analysis results were also good. Mean radiation dose for thoracic CTAA was 5.6 mSv versus 20.6 mSv of ECG-gated protocol and 20.6 mSv of 16-slice CTAA scans, with an average dose reduction of 72.8 % (p < 0.001). Mean radiation dose for thoracic-abdominal CTAA was 9.7 mSv, versus 20.9 mSv of 16-slice CTAA scans, with an average dose reduction of 53.6 % (p < 0.001). Non ECG-gated 128-slice CTAA is feasible and able to provide high quality visualization of the entire aorta without significant motion artefacts, together with a considerable dose and contrast media volume reduction. (orig.)

  8. 128-slice acceletated-pitch dual energy CT angiography of the head and neck: comparison of different low contrast medium volumes.

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    Yu Chen

    Full Text Available BACKGROUND: Our study aims to evaluate the image quality and feasibility of 128-slice dual-energy CTA (DE-CTA for supra-aortic arteries using reduced amounts of contrast medium (CM. METHODS: A prospective study was performed in 54 patients receiving CTA of the head and neck with a 128-slice dual-source CT system. Patients were randomized into two groups with a volume of either 40 mL of CM (Group I or 50 mL of CM (Group II. Arterial and venous enhancements were recorded for quantitative assessment. Qualitative assessments for images without bone removal (BR were based on a the visualization of the circle of Willis and b streak artifacts due to residual CM in the subclavian or internal jugular veins ipsilateral to injection of CM. Qualitative assessment of dual-energy images using BR was based on the presence of bone remnants and vessel integrity. Quantitative data was compared using the Student t test. The χ(2 test was used for the qualitative measurements of streak artifacts in veins while the Mann-Whitney U test was used for the qualitative measurements of images with BR. RESULTS: Arterial and venous attenuation was significantly higher in Group II (P=0.000. Image quality regarding the circle of Willis was excellent in both groups (3.90±0.30 for Group I and 4.00±0 for Group II . Imaging of the internal jugular veins was scored higher in Group I (1.87±0.72 compared with Group II (1.48±0.51 (P=0.021. Within Group I using BR, mean scores for bone remnants did not differ significantly (P>0.05 but mean scores of vessel integrity (P<0.05 did. CONCLUSIONS: Contrast-enhanced head and neck CTA is feasible using a scan protocol with low amounts of contrast medium (40 mL on a 128-slice dual-energy CTA. The 40-mL protocol provides satisfactory image quality before and after dual-energy bone-removal post-processing.

  9. Carotid CT-angiography: Low versus standard volume contrast media and low kV protocol for 128-slice MDCT

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    Kayan, Mustafa, E-mail: drkayan32@hotmail.com [Süleyman Demirel University, Faculty of Medicine, Dept. of Radiology, Isparta (Turkey); Köroğlu, Mert; Yeşildağ, Ahmet; Ceylan, Ergun; Aktaş, Aykut Recep; Yasar, Selçuk [Süleyman Demirel University, Faculty of Medicine, Dept. of Radiology, Isparta (Turkey); Aynali, Giray [Suleyman Demirel University, Faculty of Medicine, Dept. of Otorhinolaryngology, Isparta (Turkey); Parlak, Cem [Antalya Education and Research Hospital, Dept. of Radiation Oncology, Antalya (Turkey); Munduz, Mehmet [Süleyman Demirel University, Faculty of Medicine, Dept. of Radiology, Isparta (Turkey); Gürses, Cemil [Antalya Education and Research Hospital, Dept. of Radiology, Antalya (Turkey)

    2012-09-15

    Availability and utilization of computed tomography angiography has been increasing recently. We aimed to assess the effectiveness of low amount of contrast media and low kV value in order to reduce possible side effects of contrast media and to provide optimization of kV value in the evaluation of the carotid artery with multi-detector computed tomography angiography. Forty one patients were randomized into two groups. Contrast media was administered at a dose of 1 ml/kg in group A patients and of 0.5 ml/kg in group B patients. kV value of 120 in group A and 100 in group B were chosen. Bolus tracking technique was used. Attenuation values of certain arterial segments were measured, and values over 200 HU were considered as significant. North American Symptomatic Carotid Endartherectomy Trial criteria were utilized in the evaluation of stenosis. Image quality in arterial segments of all cases was found to be sufficient for diagnosis. Arterial attenuation values were found to be higher in group B than group A. When compared separately in all arterial segments, there was no statistically significant difference between the groups. For stenosis, 615 arterial segments were evaluated. Moderate stenosis in eight segments and severe stenosis in three segments were identified in group A. Occlusion in three segments, severe stenosis in three segments, and moderate stenosis in 25 segments were detected in group B. Better image quality can be obtained, and the amount of contrast media can be reduced using low kV technique in carotid artery multi-detector computed tomography angiography examination.

  10. Comparison of 128-Slice Low-Dose Prospective ECG-Gated CT Scanning and Trans-Thoracic Echocardiography for the Diagnosis of Complex Congenital Heart Disease

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    Bu, Guilin; Miao, Ying; Bin, Jingwen; Deng, Sheng; Liu, Taowen; Jiang, Hongchun; Chen, Weiping

    2016-01-01

    Objective To compare prospective ECG-gated multi-slice computed tomography (MSCT) and trans-thoracic echocardiography (TTE) in the diagnosis of complex congenital heart disease (CHD). Methods This was a prospective study of consecutive patients with complex CHD (age ECG-gated 128-slice spiral CT in the week before surgery. Effective radiation dose (ED) was calculated from volume CT dose index (CTDIvol) and dose length product (DLP). Image quality (5-point scale) was assessed independently by two radiologists. Using surgical findings as the reference, the diagnostic capabilities of MSCT and TTE were compared. Results Thirty-five patients (19 males) aged 1.59±1.58 years (range, 3 days to 74 months) were included. CTDIvol, DLP and ED were 0.90±0.24 mGy, 12.9±4.7 mGy∙cm and 0.64±0.21 mSv (range, 0.358–1.196 mSv), respectively. Image quality score was 4.3±0.5, and all images met the diagnostic requirements. The sensitivity, specificity, positive predictive value, and negative predictive value for diagnosing CHD were 97.2%, 99.8%, 99.0%, and 99.5%, respectively, for MSCT, and 90.6%, 99.8%, 99.0%, and 98.4%, respectively, for TTE. MSCT not only had a higher sensitivity than TTE overall (97.2% vs. 90.6%; PECG-gated CT scanning has important clinical value in the diagnosis of complex CHD in children, complementing and extending the findings of TTE. PMID:27788237

  11. Evaluation of high-pitch flash scan for pulmonary venous CTA on a 128-slice dual source CT: compared with prospective ECG-triggered sequence scan.

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    Cao, Li Xiu; Zhang, Huan; Liu, Bo; Yang, Wen Jie; Zhang, Yan Yan; Pan, Zi Lai; Yan, Fu Hua; Chen, Ke Min

    2013-10-01

    To compare the image quality (IQ) and radiation dose of high-pitch scan and prospective ECG-triggered sequence scan on a 128-slice DSCT system for patients with atrial fibrillation (AF). Pulmonary venous (PV) CTA was performed with two protocols, including high-pitch scan and prospective ECG-triggered sequence scan. For each protocol, 20 sex, age and body-mass-index (mean 24.2 kg/m(2)) matched patients were identified. Two experienced radiologists, who were blinded to the scan protocols, independently graded the CT images of the two groups by a 5-point scale for subjective IQ assessment. Measured CT attenuation (Hounsfield units ± standard deviation), signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) at various anatomic locations were also recorded for objective IQ evaluation. Radiation exposure parameters [dose length product (DLP) and effective radiation dose (ERD)] were compared. Twenty-three patients (57.5 %) showed an ECG pattern of AF in total. Subjective IQ was rated excellent in 100 % for the high-pitch scan group, while minor step artifacts were observed in two patients (10 %) with arrhythmia for the prospective ECG-triggered sequence group. There was no significant difference on IQ, neither by subjective, nor by objective measures (SNR, CNR) between the two groups. The ERD of high-pitch flash scan and prospective ECG-triggered sequence scan were 0.9 (± 0.25) and 2.9 (± 0.69) mSv, respectively. Significantly lower radiation was achieved by using high-pitch flash scan (P < 0.05). High-pitch flash scan can provide similar subjective and objective IQ compared with prospective ECG-triggered sequence scan for PV CTA, while radiation exposure was significantly reduced. PMID:23645131

  12. Evaluation of a Chest Circumference-Adapted Protocol for Low-Dose 128-Slice Coronary CT Angiography with Prospective Electrocardiogram Triggering

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    Lu, Chenying; Wang, Zufei; Ji, Jiansong; Wang, Hailin; Hu, Xianghua; Chen, Chunmiao [Department of Radiology, Lishui Central Hospital, The Fifth Affiliated Hospital of Wenzhou Medical College, Lishui, Zhejiang 323000 (China)

    2015-11-01

    To assess the effect of chest circumference-adapted scanning protocol on radiation exposure and image quality in patients undergoing prospective electrocardiogram (ECG)-triggered coronary CT angiography (CCTA). One hundred-eighty-five consecutive patients, who had undergone prospective ECG triggering CCTA with a 128-slice CT, were included in the present study. Nipple-level chest circumference, body weight and height were measured before CT examinations. Patients were divided into four groups based on kV/ref·mAs = 100/200, 100/250, 120/200, and 120/250, when patient's chest circumference was ≤ 85.0 (n = 56), 85.0-90.0 (n = 53), 90.0-95.0 (n = 44), and > 95.0 (n = 32), respectively. Image quality per-segment was independently assessed by two experienced observers. Image noise and attenuation were also measured. Signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were calculated. The effective radiation dose was calculated using CT dose volume index and the dose-length product. A significant correlation was observed between patients' chest circumference and body mass index (r = 0.762, p < 0.001). Chest circumference ranged from 74 to 105 cm, and the mean effective radiation dose was 1.9-3.8 mSv. Diagnostic image quality was obtained in 98.5% (2440/2478) of all evaluated coronary segments without any significant differences among the four groups (p = 0.650). No significant difference in image noise was observed among the four groups (p = 0.439), thus supporting the validity of the chest circumference-adapted scanning protocol. However, vessel attenuation, SNR and CNR were significantly higher in the 100 kV groups than in the 120 kV groups (p < 0.05). A measure of chest circumference can be used to adapt tube voltage and current for individualized radiation dose control, with resultant similar image noise and sustained diagnostic image quality.

  13. Step-and-shoot prospectively ECG-gated versus retrospectively ECG-gated with tube current modulation coronary CT angiography using the 128-slice MDCT: comparison of image quality and radiation dose

    International Nuclear Information System (INIS)

    Background: Little is known regarding image quality and the required radiation dose for step-and-shoot and retrospective coronary computed tomography angiography (CCTA) with tube current modulation (TCM) in 128-slice multidetector CT (MDCT) coronary angiography. Purpose: To compare image quality and radiation dose in patients who underwent 128-slice MDCT by the step-and- shoot method with those in patients who underwent 128-slice MDCT with retrospective CCTA with TCM. Material and Methods: CCTA obtained with 128-slice MDCT was retrospectively evaluated in 160 patients. Two independent reviewers separately scored the subjective image quality of the coronary artery segments (1, excellent; 4, poor) for step-and-shoot (68, mean heart rate [HR]: 59.3±6.8) and retrospective CCTA with TCM (77, mean HR: 59.1±9.8). Interobserver variability was calculated. Effective radiation doses of both scan techniques were calculated with dose-length product. Results: There was good agreement for quality scores of coronary artery segment images between the independent reviewers (k=0.72). The number of coronary artery segments that could not be evaluated was 2.85% (27 of 947) in the step-and-shoot and 1.87% (20 of 1071) in retrospective CCTA with TCM. Image quality scores were not significantly different (P>.05). Mean patient radiation dose was 63% lower for step-and-shoot (1.94±0.70 mSv) than for retrospective CCTA with TCM (4.51±1.18 mSv) (P<0.0001). For patients who underwent step-and-shoot or retrospective CCTA with TCM, an average HR of 63.5 beats per minute was identified as the threshold for the prediction of non-diagnostic image quality for both protocols. There were no significant differences in the image quality of both methods between obese (body mass index [BMI≥25) and non-obese patients (BMI<25), but radiation doses were higher in the obesity group than in the non-obesity group for both methods. Conclusion: Both step-and-shoot and retrospective CCTA with TCM using 128

  14. Step-and-shoot prospectively ECG-gated versus retrospectively ECG-gated with tube current modulation coronary CT angiography using the 128-slice MDCT: comparison of image quality and radiation dose

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    Jeong, Dong Wook (Dept. of Family Medicine, Medial Research Institute, Pusan National Univ. Yangsan Hospital, School of Medicine, Gyeongsangnam-do, (Korea, Republic of)); Choo, Ki Seok; Baik, Seung Kug; Kim, Yong Woo; Jeon, Ung Bae (Dept. of Radiology, Medial Research Institute, Pusan National Univ. Yangsan Hospital, School of Medicine, Gyeongsangnam-do, (Korea, Republic of)), email: kschoo0618@naver.com; Kim, Jeong Soo (Dept. of Cardiology, Medial Research Institute, Pusan National Univ. Yangsan Hospital, School of Medicine, Gyeongsangnam-do (Korea, Republic of)); Lim, Soo Jin (Dept. of Cardiology, Kim Hae Joongang Hospital, Gyeongsangnam-do (Korea, Republic of))

    2011-02-15

    Background: Little is known regarding image quality and the required radiation dose for step-and-shoot and retrospective coronary computed tomography angiography (CCTA) with tube current modulation (TCM) in 128-slice multidetector CT (MDCT) coronary angiography. Purpose: To compare image quality and radiation dose in patients who underwent 128-slice MDCT by the step-and- shoot method with those in patients who underwent 128-slice MDCT with retrospective CCTA with TCM. Material and Methods: CCTA obtained with 128-slice MDCT was retrospectively evaluated in 160 patients. Two independent reviewers separately scored the subjective image quality of the coronary artery segments (1, excellent; 4, poor) for step-and-shoot (68, mean heart rate [HR]: 59.3+-6.8) and retrospective CCTA with TCM (77, mean HR: 59.1+-9.8). Interobserver variability was calculated. Effective radiation doses of both scan techniques were calculated with dose-length product. Results: There was good agreement for quality scores of coronary artery segment images between the independent reviewers (k=0.72). The number of coronary artery segments that could not be evaluated was 2.85% (27 of 947) in the step-and-shoot and 1.87% (20 of 1071) in retrospective CCTA with TCM. Image quality scores were not significantly different (P>.05). Mean patient radiation dose was 63% lower for step-and-shoot (1.94+-0.70 mSv) than for retrospective CCTA with TCM (4.51+-1.18 mSv) (P<0.0001). For patients who underwent step-and-shoot or retrospective CCTA with TCM, an average HR of 63.5 beats per minute was identified as the threshold for the prediction of non-diagnostic image quality for both protocols. There were no significant differences in the image quality of both methods between obese (body mass index [BMI>=25) and non-obese patients (BMI<25), but radiation doses were higher in the obesity group than in the non-obesity group for both methods. Conclusion: Both step-and-shoot and retrospective CCTA with TCM using 128

  15. Multi-detector CT knee arthrography - initial experience

    International Nuclear Information System (INIS)

    Full text: Traditional plain film arthrography can achieve reasonable accuracy and is an accepted method of investigation of patients with knee pain and possible meniscal tear. Multi-detector CT can potentially provide a more detailed and accurate examination due to its high-resolution crosssectional and multi-planar capabilities. The aim of this study was to assess the accuracy of our technique. All patients who underwent a multi-detector CT knee arthrogram in an initial 8 month period were identified. Initially the referring clinician was contacted. If the patient was referred to an orthopaedic surgeon the outcome of orthopaedic review was recorded using clinical, arthroscopic and / or MRI follow-up of the patient population. One hundred and twelve patients had a Multi-detector CT knee arthrogram performed within and 8 month period. Follow-up information was received in 69.7% of patients. Of these 68.9% had orthopaedic assessment - of which 69.2% underwent a knee arthroscopy.There was total agreement of findings in 67%, agreement of meniscal findings in 67% and chondral findings in 100%. Overall, orthopaedic opinion agreed with CT findings in 76.9%. At this stage, all meniscal tears not described in the initial CT arthrogram report have in retrospect been visible. Multi-detector CT knee arthrography is an accurate and elegant technique for investigation of knee pain, providing information in a format familiar to those reporting knee MRI. There is an initial learning curve. The technique is particularly useful in chondral assessment. It is accurate for meniscal pathology, although caution and recognition of potential pitfalls is required. Copyright (2002) Blackwell Science Pty Ltd

  16. Contrastive Research on the Reliability of 128-Slice Spiral CT in the Measurement of Normal Occlusion Model%128层螺旋CT在正常模型测量中的可靠性研究

    Institute of Scientific and Technical Information of China (English)

    常捷; 李武; 滕永健; 赵晶帆

    2014-01-01

    Objective To verify the reliability, repeatability and accuracy of 128-slice spiral CT through comparing the measurement results of 128-slice spiral CT of 20 normal chin models with those of traditional manual measurement results.Methods The volume scanning with its data collection of normal chin models were conducted with 128-slice spiral CT. Then the images whose slice thicknesses were 0.6 mm were obtained through function reconstruction and then were transferred to various softwares including the 3D workstation, Dental and Inspace. The related indicators including the teeth width, dental arch length and dental arch width of maxillary and mandibular teeth were measured with axial images, MPR (Multiplanar Reconstruction), CPR (Curve Planar Reconstruction) and VR (Volume Reconstruction) while these indicators were also measured with vernier caliper manually. The measurement data collected from those two methods were analyzed and compared.Results The parallel validity of manual measurement was similar to CT measurement whose measurement error was-0.02~0.02 mm.Conclusion 128-slice spiral CT can meet the clinical orthodontic requirements.%目的:通过对20副正常模型的128层螺旋CT测量结果与传统手工测量结果进行比较,验证128层螺旋CT系统的可靠性、可重复性、精确性。方法应用128层螺旋CT机对正常模型进行容积扫描、数据采集,并进行函数重建得到0.6 mm层厚图像,传送至配套3D工作站、Dental(齿科软件)、Inspace(4D无间断实时互动三维成像技术)等软件,利用轴位图像、MPR(多平面重建)、CPR (曲面重建)、VR(容积重建)等方法测量正常模型的上、下颌牙的牙齿宽度,牙弓长度、宽度等相关指标;同时用游标卡尺手工测量上述指标,将两种测量方法所得数据进行比较。结果两种测量方法具有相似的平行效度。CT系统的测量误差为-0.02~0.02 mm,精确度较高。结论128层

  17. Research on 128-slice CT perfusion imaging of perigastric lymph node metastases of advanced gastric cancer%进展期胃癌胃周淋巴结的128层CT灌注成像研究

    Institute of Scientific and Technical Information of China (English)

    左晓娜; 曲红光; 王治民

    2016-01-01

    Objective:By studying the 128-slice spiral CT perfusion imaging of gastric cancer, this study aimed to investigate the per⁃fusion curves and perfusion imaging features of metastatic perigastric lymph nodes, reactive lymphoid hyperplasia (RLH) in the active stage and RLH in the quiescent stage;to find out the differences of the perfusion indexes including blood flow (BF), blood volume (BV), mean transit time (MTT) and permeability surface (PS) of the different types of lymph nodes in advanced gastric cancer. Methods:From the 30 patients with gastric cancer diagnosed by surgery and pathological examination admitted in Gansu Provincial Hospital, 35 metastatic lymph nodes (Group A), 53 lymph nodes with reactive lymphoid hyperplasia (RLH) in the active stage (Group B) and 27 RLH lymph nodes in the quiescent stage were selected, and the time-density curves (TDC) of the three groups were compared, then the differences of the perfusion indexes were com⁃pared and analyzed by one-way analysis of variance (one-way ANOVA). Results:①The 128-slice spiral CT perfusion imaging of gastric can⁃cer could demonstrate the perfusion information inside the different types of perigastric lymph nodes, and could reflect the physiological func⁃tions of the lymph nodes precisely;②The results of BF, BV, MTT and PS of metastatic perigastric lymph nodes, RLH lymph nodes in the reac⁃tive stage and RLH lymph nodes in the quiescent stage were statistically different. Conclusion: The 128-slice spiral CT perfusion imaging of gastric cancer can reflect the changes of the perfusion indexes of perigastric lymph nodes visually, and can provide the objective and quantita⁃tive information of thehemodynamic changes of the lymph nodes. Combined with enhanced imaging and various post-processing technologies, the 128-slice spiral CT perfusion imaging can provide more valuable information for thelocating and the qualitative diagnosis of the perigastric lymph nodes and the preoperative staging

  18. Initial experience with prospectively triggered, sequential CT coronary angiography on a 128-slice scanner; Erste Erfahrungen mit der sequenziellen, prospektiv getriggerten CT-Koronarangiografie an einem 128-Schicht-Computertomografen

    Energy Technology Data Exchange (ETDEWEB)

    Anders, K.; Baum, U.; Kuefner, M.A.; Kuettner, A.; Uder, M. [Universitaetsklinikum Erlangen (Germany). Radiologisches Inst.; Gauss, S.; Achenbach, S.; Daniel, W.G.; Ropers, D. [Universitaetsklinikum Erlangen (Germany). Medizinische Klinik 2

    2009-04-15

    Purpose: Spiral CT angiography (CTA) of the coronaries using low-pitch scanning and ECG-gated image reconstruction is a robust method for detecting or excluding relevant coronary plaque. However, the resulting dose exposure is considerable. The aim of the present study was to evaluate image quality and artifacts as well as to record dose values for sequential coronary CTA using a 128-slice scanner with a temporal resolution of 150 ms. Materials und Methods: 20 patients with a regular heart rate and without contraindications for oral/I.V. beta blockers, who were referred for CTA of the coronaries for exclusion or detection of relevant plaques, were examined by sequential CTA with the following parameters: 120 kV, 200 ref mAs, collimation 2 x 64 x 0.6, table feed of 34.5 mm at a detector width of 38.4 mm. A total acquisition time of 380 ms per table position allowed for mild shifting of the reconstruction window within the cardiac cycle of {+-} 5 %. 50 ml of contrast agent were injected at 5 ml/s followed by a 50 ml split bolus (20 % contrast). The individual start delay was determined by a test bolus scan (10 ml contrast + 50 ml saline flush at 5 ml/s). The image quality for each segment, coronary artery, and patient was determined on a 4-point scale. Dose values were estimated based on the individual dose length product as provided by the scanner's patient protocol. Artifacts were evaluated to determine the cause (calcium vs. motion). Results: All patients received beta blocker pretreatment. The mean heart rate was 62 {+-} 5 beats/min. 5 % (13/286) of all segments in 5/20 patients were rated as non-diagnostic. The mean dose length product was 213 mGy x cm, and the mean effective dose was 3.6 mSv. Calcifications were the major cause of non-diagnostic images. However breathing or other motion artifacts occurred as well. (orig.)

  19. 128层螺旋CT对肠扭转的诊断价值%Value of 128 Slice Spiral CT in Diagnosis of Intestinal Volvulus

    Institute of Scientific and Technical Information of China (English)

    范胜坤

    2015-01-01

    Objective Study 128 F spiral the CT turn round to the bowel of diagnosis value. Methods Review analysis 40 before the Shu the CT explicit diagnosis combine through surgical operation confirmation turn round for the bowel of clinical and image data. Results 40s are al through surgical operation confirmation, among them, the smal intestines turn round 31, 12 the bowel turn round 1 and the colon turn round 8.26 bowel tube has whirlpool to advertise for and 28 bowel fasten film blood vessel to have whirlpool to advertise for and 21 have banana to advertise for and 28 have beak to advertise for and 3 have bowel to fasten a film to change to advertise for up vein and artery, 32 have Ba wreath to advertise for, and 10 bowel fasten film artery to have blood to bolt formation. Conclusion 128 F spiral CT and empress processing technique of comprehensive usage turn round to the bowel of fixed position and set le sex have importance value, Be that the head choose check method.%目的探讨128层螺旋CT对肠扭转的诊断价值。方法回顾性分析40例术前CT明确诊断并经手术证实为肠扭转的临床及影像资料。结果40例全部经手术证实,其中小肠扭转31例,十二指肠扭转1例,结肠扭转8例。26例肠管有漩涡征,28例肠系膜血管有漩涡征,21例有香蕉征,28例有鸟喙征,3例有肠系膜上静脉和动脉换位征,32例有靶环征,10例肠系膜动脉有血栓形成。结论128层螺旋CT及后处理技术的综合运用对肠扭转的定位及定性有重要价值,可作为首选检查方法。

  20. Comparison of CT numbers between cone-beam CT and multi-detector CT

    International Nuclear Information System (INIS)

    To compare the CT numbers on 3 cone-beam CT (CBCT) images with those on multi-detector CT (MDCT) image using CT phantom and to develop linear regressive equations using CT numbers to material density for all the CT scanner each. Mini CT phantom comprised of five 1 inch thick cylindrical models with 1.125 inches diameter of materials with different densities (polyethylene, polystyrene, plastic water, nylon and acrylic) was used. It was scanned in 3 CBCTs (i-CAT, Alphard VEGA, Implagraphy SC) and 1 MDCT (Somatom Emotion). The images were saved as DICOM format and CT numbers were measured using OnDemand 3D. CT numbers obtained from CBCTs and MDCT images were compared and linear regression analysis was performed for the density, ρ(g/cm3), as the dependent variable in terms of the CT numbers obtained from CBCTs and MDCT images. CT numbers on i-CAT and Implagraphy CBCT images were smaller than those on Somatom Emotion MDCT image (p<0.05). Linear relationship on a range of materials used for this study were ρ=0.001 H+1.07 with R2 value of 0.999 for Somatom Emotion, ρ=0.002 H+1.09 with R2 value of 0.991 for Alphard VEGA, ρ=0.001 H+1.43 with R2 value of 0.980 for i-CAT and ρ=0.001 H+1.30 with R2 value of 0.975 for Implagraphy. CT numbers on i-CAT and Implagraphy CBCT images were not same as those on Somatom Emotion MDCT image. The linear regressive equations to determine the density from the CT numbers with very high correlation coefficient were obtained on three CBCT and MDCT scan.

  1. 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.

  2. Radiation dose for thoracic and coronary step-and-shoot CT using a 128-slice dual-source machine in infants and small children with congenital heart disease

    Energy Technology Data Exchange (ETDEWEB)

    Paul, Jean-Francois; Rohnean, Adela; Elfassy, Eric; Sigal-Cinqualbre, Anne [Radiology-Centre Chirurgical Marie Lannelongue, Plessis-Robinson (France)

    2011-02-15

    For coronary artery visualization, retrospective ECG-gated acquisition by dual-source computed tomography (DSCT) was superior to spiral non-ECG-gated acquisition in a paediatric population of congenital heart disease (CHD) patients. However, retrospective cardiac CT is associated with substantial radiation doses to the patient. Recently, DSCT with end-systolic reconstruction was found to be robust for imaging the coronary arteries in patients with high heart rates. To evaluate step-and-shoot DSCT with end-systolic reconstruction for evaluating the heart, coronary arteries and other thoracic structures in young children with CHD. All neonates and children younger than 6 years of age who were referred to our institution for CHD evaluation between September and October 2009 were included in the study. ECG-gated DSCT was performed in sequential prospective mode centred on the systolic phase identified by ECG analysis. To assess the radiation dose, we recorded the dose-length product (DLP) in mGy.cm and the effective dose in mSv estimated from the DLP. Overall image quality was evaluated using a 5-grade scoring system and was assessed by looking at cardiac and vascular structures. The image quality for the proximal and middle segments of the right and left coronary arteries was also evaluated using a 5-grade scale. Images of diagnostic quality (grade {>=} 3) were obtained in all 30 children with a mean image quality grade of 4.7 {+-} 0.6 (range, 3-5). Mean DLP was 5.7 {+-} 4.8 mGy*cm (range, 1-22 mGy cm) and mean effective radiation dose was 0.26 {+-} 0.16 mSv (range, 0.05-0.8 mSv). Prospective ECG-gated thoracic DSCT at end-systole usually provides adequate thoracic and coronary artery image quality in neonates, infants and young children with CHD, independent of heart rate. This new method is associated with lower radiation doses compared to previous literature (mean effective dose, 0.26 mSv). (orig.)

  3. Multi-detector CT/CT angiogram assessment of acute pancreatic graft dysfunction

    International Nuclear Information System (INIS)

    Simultaneous pancreatic-kidney transplantation is the definitive treatment for patients with type 1 diabetes mellitus and renal failure. Pancreatic graft failure is an important postoperative complication and most commonly occurs as a result of pancreatitis, graft thrombosis or rejection. Distinguishing between these causes is necessary to determine timely, appropriate management and thereby potentially minimising graft loss. Multi-detector CT imaging may be used to identify the cause of pancreatic graft dysfunction when renal function is not markedly impaired.

  4. Research of reducing radiation quantity in abdominal CT by 128 slices spiral CT and axial scanning technology%研究128层螺旋CT和轴扫技术降低腹部CT检查辐射量的作用

    Institute of Scientific and Technical Information of China (English)

    吴鸿

    2014-01-01

    Objective To investigate the effect of reducing radiation quantity in abdominal CT by 128 slices spiral CT and axial scanning technology. Methods A total of 27 patients receiving abdominal CT were taken as study subjects, and they were randomly divided into two groups. Group A with 14 cases received 128 slices spiral CT scanning, and group B with 13 cases received axial scanning. Plain scan and enhancement scan were performed in both groups, and the image quality, noise level and radiation dose were observed. Results There was no statistically significant difference of image quality and noise level in plain scan and enhancement scan between the two groups (P>0.05). Group A had a higher radiation dose of X-Ray than group B, and the difference had statistical significance (P0.05), A组X线的辐射剂量明显比B组高,差异有统计学意义(P<0.05)。结论患者使用128层螺旋CT和轴扫技术所获得的图像均有较高质量,但是轴扫技术的腹部CT的辐射剂量明显低于128层螺旋CT扫描,更值得在临床应用和推广。

  5. 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.)

  6. Accuracy, image quality and radiation dose comparison of high-pitch spiral and sequential acquisition on 128-slice dual-source CT angiography in children with congenital heart disease

    Energy Technology Data Exchange (ETDEWEB)

    Nie, Pei; Wang, Ximing; Cheng, Zhaoping; Ji, Xiaopeng; Duan, Yanhua [Shandong University, Shandong Provincial Key Laboratory of Diagnosis and Treatment of Cardio-cerebral Vascular Diseases, Shandong Medical Imaging Research Institute, Jinan, Shandong (China); Chen, Jiuhong [CT Research Collaboration, Siemens Ltd. China, Beijing (China)

    2012-10-15

    To compare accuracy, image quality and radiation dose between high-pitch spiral and sequential modes on 128-slice dual-source computed tomographic (DSCT) angiography in children with congenital heart disease (CHD). Forty patients suspected with CHD underwent 128-slice DSCT angiography with high-pitch mode and sequential mode respectively. All the anomalies were confirmed by the surgical and/or the conventional cardiac angiography (CCA) findings. The diagnostic accuracy, the subjective and objective image quality and effective radiation doses were compared. There was no significant difference in diagnostic accuracy ({chi}{sup 2} = 0.963, P > 0.05), the objective parameters for image quality (P > 0.05) and the image quality of great vessels (u = 167.500, P > 0.05) between the two groups. The image quality of intracardiac structures and coronary arteries was significantly better in the sequential mode group than that in the high-pitch group (u = 112.500 and 100.000, P < 0.05). The mean effective dose in high-pitch group (0.17 {+-} 0.05 mSv) was significantly lower (t = 5.287, P < 0.05) than that in the sequential mode group (0.29 {+-} 0.09 mSv). Both the high-pitch and the sequential modes for 128-slice DSCT angiography provide high accuracy for the assessment of CHD in children, while the high-pitch mode, even with some image quality decrease, further significantly lowers the radiation dose. (orig.)

  7. Multi-detector CT imaging in the postoperative orthopedic patient with metal hardware

    Energy Technology Data Exchange (ETDEWEB)

    Vande Berg, Bruno [Department of Radiology, Cliniques Universitaires Saint-Luc, 10 Avenue Hippocrate, 1200 Brussels (Belgium)]. E-mail: vandeberg@rdgn.ucl.ac.be; Malghem, Jacques [Department of Radiology, Cliniques Universitaires Saint-Luc, 10 Avenue Hippocrate, 1200 Brussels (Belgium); Maldague, Baudouin [Department of Radiology, Cliniques Universitaires Saint-Luc, 10 Avenue Hippocrate, 1200 Brussels (Belgium); Lecouvet, Frederic [Department of Radiology, Cliniques Universitaires Saint-Luc, 10 Avenue Hippocrate, 1200 Brussels (Belgium)

    2006-12-15

    Multi-detector CT imaging (MDCT) becomes routine imaging modality in the assessment of the postoperative orthopedic patients with metallic instrumentation that degrades image quality at MR imaging. This article reviews the physical basis and CT appearance of such metal-related artifacts. It also addresses the clinical value of MDCT in postoperative orthopedic patients with emphasis on fracture healing, spinal fusion or arthrodesis, and joint replacement. MDCT imaging shows limitations in the assessment of the bone marrow cavity and of the soft tissues for which MR imaging remains the imaging modality of choice despite metal-related anatomic distortions and signal alteration.

  8. Value of low-dose 128 slice spiral CT in diagnosis and treatment of endo-tracheal and bronchial negative foreign bodies of children%128层CT低剂量扫描在幼儿气管、支气管非金属异物诊断中的价值

    Institute of Scientific and Technical Information of China (English)

    蒋洪春; 林薇

    2012-01-01

    目的:探讨128层螺旋CT低剂量扫描在幼儿气管支气管阴性异物诊治中的临床应用价值.方法:回顾性分析经支气管内镜检取异物的16例幼儿气管支气管非金属异物患者的128层螺旋CT影像学资料.128层CT低剂量扫描选用个体化方案(100或120kV; Eft.mAs:30~40mA;CARE D()SE 4D:打开);层厚3mm;螺距:1.4;时间1.33s;常规1mm原始重组,记录每位患儿的平均有效剂量(mGy),将容积数据进行多平面重组(MPR)、曲面重组(CPR)、最小密度投影(Min-IP),并将CT与内镜结果对比分析.结果:16例低剂量扫描图像均符合诊断要求,128层CT发现异物位于气管5例,气管分叉上方1例,右侧主支气管及分支异物5例,左侧主支气管及分支异物4例,双侧支气管均有异物1例.128层螺旋CT低剂量扫描技术在幼儿气管支气管非金属异物诊断中的敏感度、准确度分别为100%、94.2%.结论:幼儿气管支气管非金属异物128层CT低剂量扫描能满足诊断,准确评估异物大小、位置、形态及肺部并发症,能减少不必要的支气管镜检及弥补X线平片的不足,具有重要的临床应用价值.%Objective:To investigate the value of low dose 128-slice spiral CT in diagnosis and treatment of endo-tracheal/ bronchial negative foreign bodies for children in clinical application. Methods: 16 children, who underwent tracheoscopy for taking out negative foreign body in endo-trachea/bronchi, were reviewed with their imaging data of 128-slice spiral CT. The low dose 128-slice spiral CT choose the individualized programs (100 or 120 kV; Eft. mAs 30~40 mA; CAREDose: 4D: open); with layer thickness of 3 mm; helical pitch 1. 4; time of 1. 33 s; and conventional original reconstruction interval of 1 mm. The mean effective dosage of radiation (mGy) was measured for all patients. Post-processing techniques included multi-planar reconstruction (MPR), curved planar reformation (CPR) , and minimum intensity projection (Min

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2009-12-15

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

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

    International Nuclear Information System (INIS)

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

  12. The clinical value on the pre-operation of styloid process syndrome diagnosed by 128-slice spiral CT%128层螺旋 CT 在茎突综合征术前诊断中的临床价值

    Institute of Scientific and Technical Information of China (English)

    左开荣

    2014-01-01

    目的:探讨128层螺旋 CT 在茎突综合征术前诊断中的临床价值。方法回顾性分析50例(100侧)正常成人(对照组)和48例(96侧)经手术证实的茎突综合征患者(SPS 组)的临床及影像资料,并对两组患者的茎突长度和倾角分布的差异进行统计分析。结果对照组中,茎突过长(长度>30mm)8侧(8%),前倾角过大(角度>25°)2侧(2%),内倾角过大(角度>25°)4侧(4%);而 SPS 组中,茎突过长56侧(58.3%),前倾角过大14侧(14.6%),内倾角过大18侧(18.8%),茎突过长伴倾角异常10侧(10.4%)。经统计学分析,SPS 组的茎突过长及倾角过大的检出率明显高于对照组,差异具有统计学意义(P<0.05)。结论茎突综合征在影像学上主要表现为茎突过长和(或)倾角过大,128层螺旋 CT 三维重建技术能为临床提供可靠的影像学依据,在茎突综合征术前诊断中具有重要临床价值。%Objective To explore the clinical value on the pre-operation of styloid process syndrome diagnosed by 128-slice spiral CT. Methods Retrospectively analyzed 50 cases (100sides) of normal adult (control group) and 48 cases(96 sides) of styloid process syndrome diagnosed by operation (SPS group). The differences between two groups in the length and angle distribution of the styloid process were analyzed statistically. Results Eight sides of control group (8%) had the elon-gated styloid process (the lenght was more than 30mm),two sides (2%) had the larger anteversion angle (the angle was more than 25°),four sides (4%) had the larger inclination angle (more than 25°);48 cases of SPS group, 56 sides (58.3%) had the elongated styloid process,14 sides (14.6%) had the larger anteversion angle, 18 sides (18.8%) had the larger inclination an-gle,10 sides (10.4%) had the elongated styloid process coupled with abnormal inclination. Analyzed by statistics, the detection

  13. Neutron CT with a multi-detector system leading to drastical reduction of the measuring time

    International Nuclear Information System (INIS)

    By means of numerical simulation methods and their verification with measurements it could be shown that such a detector system can be realized for a line beam and 1-2 detectors per cm. With the maximum available beam width of the fast neutron field at the FRM approximately 20 detectors can be used leading to a reduction of the measuring time to 0,5 - 1 hour. A multi detector system for a line beam of thermal neutrons was constructed, tested and used for CT-measurements. This detector system for the measurement of thinner layers with better spatial resolution could be realized. The electronic discrimination between neutrons and gamma rays has been improved. This discrimination was used in all CT-measurements to get transmission values of both kinds of radiation and to reconstruct to complementary CT-images. The use of a polyenergetic radiation causes spectral shifts in the transmission spectrum leading to artifacts in the reconstructed CT-image. The transmission values must be spectral corrected before image reconstruction, because the image artifacts complicate the image evaluation or make it impossible. A new energy selective procedure for the online spectral correction was developed. This method is based on the concept to measure additionally to the integral transmission value his pulse height spectrum and to do the correction depending on the changes in this pulse height spectrum. (orig./HP)

  14. 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.)

  15. Paratracheal air cysts: prevalence and correlation with lung disease using multi-detector CT

    International Nuclear Information System (INIS)

    The purpose of this study was to determine the prevalence of paratracheal air cysts (PACs), their correlation with different lung diseases and their connection with the trachea by chest multi detector computed tomography (MDCT). We retrospectively reviewed chest MDCT images of 8240 consecutive patients obtained from January 2010 to December 2011 with a 16-detector multi-detector CT scanner. PACs were assessed for prevalence, location, level, size and the presence of visible communication with the trachea. MDCT diagnoses were classified as normal, primary or metastatic malignancies, chronic obstructive pulmonary disease (COPD), pneumonia and other lung diseases. We randomly selected 330 patients who had no visible PACs for the control group. We evaluated the associations between patients' demographic findings (age and sex), MDCT findings of lung and the presence of PACs. The findings of the PACs and control groups were compared. Statistical analysis used chi-squared test and Mann - Whitney U-test for evaluation. PACs were presented in 301 patients (4%); 204 men and 97 women, ranging in age from 14 to 91 years (median=57 years). There was no significant difference in the presence of PACs by age (P>0.05). Male subjects showed higher prevalence (P=0.005). Fifty PACs (16.6%) showed communication with the trachea or main bronchus. Although the relation between COPD and PACs was statistically significant (P<0.001), there was no relation between primary or metastatic malignancies, pneumonia and other lung diseases and PACs. PACs are common in MDCT and should not be misdiagnosed as pneumomediastinum. It should be kept in mind that PACs may be associated with COPD.

  16. 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...

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

    Institute of Scientific and Technical Information of China (English)

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

    2014-01-01

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

  18. Diagnosis of deep vein thrombosis using multi-detector helical CT

    Energy Technology Data Exchange (ETDEWEB)

    Kimura, Masashi; Minamiguchi, Hiroki; Sahara, Shinya [Wakayama Medical Coll. (Japan)] [and others

    2002-11-01

    The purpose of this study was to evaluate the usefulness of multi-detector helical CT (MDHCT) with contrast medium in the diagnosis of deep vein thrombosis (DVT). The bilateral veins of the dorsal pedis in 45 patients (12 men, 33 women; average age, 64 years) under clinical suspicion of DVT were first punctured using 22-G needles. Then CT scanning from the level of the foot to the inferior vena cava was started 20 sec after the initial injection of 200 mL of dilute contrast medium (50 mL nonionic iodinated contrast medium of 300 mgI/mL and 150 mL saline) at a rate of 5 mL/sec. Two patients were excluded because of unsuccessful venous puncture. The average scanning time in 43 patients was 38.5{+-}7.9 seconds. Images of veins from the foot to the inferior vena cava were clearly demonstrated in each case. MDHCT showed DVT in 32 cases and patent deep vein in 11 cases. Simultaneous venography of the lower extremity in 18 patients clearly visualized DVT at the same level detected by contrast MDHCT. MDHCT for the diagnosis of DVT has the advantages of wider scanning rage, shorter scanning time, and finer Z-axis resolution than the other diagnostic modalities. (author)

  19. 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)

  20. 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.

  1. 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

  2. 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

  3. 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.)

  4. 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)

  5. Multi-detector CT angiography for lower gastrointestinal bleeding: can it select patients for endovascular intervention?

    International Nuclear Information System (INIS)

    Full text: This is a retrospective review of the results at our institution of using multi-detector CT angiography (CTA) to localise lower gastrointestinal (GI) bleeding. We hypothesised that in our patient population: (i) CTA was unlikely to demonstrate bleeding in patients who were haemodynamically stable; (ii) in haemodynamically unstable patients in whom CTA was undertaken, the results could be used to select patients who would benefit from catheter angiography; and (iii) in haemodynamically unstable patients in whom CTA was undertaken, a subgroup of patients could be identified who would benefit from primary surgical treatment, avoiding invasive angiography completely. A retrospective review was conducted of the clinical records of all patients undergoing CTA for lower GI haemorrhage at our institution between 1 January 2005 and 30 June 2007. Out of the 20 patients examined, 10 had positive CTAs demonstrating the bleeding site. Nine were haemodynamically unstable at the time of the study. Four patients with positive CT angiograms were able to be treated directly with surgery and avoided invasive angiography. Ten patients had negative CTAs. Four of these were haemodynamically unstable, six haemodynamically stable. Only one required intervention to secure haemostasis, the rest stopped spontaneously. No haemodynamically stable patient who had a negative CTA required intervention. CTA is a useful non-invasive technique for localising the site of lower GI bleeding. In our patient population, in the absence of haemodynamic instability, the diagnostic yield of CTA was low and bleeding was likely to stop spontaneously. In haemodynamically unstable patients, a positive CTA allowed patients to be triaged to surgery or angiography, whereas there was a strong association between a negative CTA and spontaneous cessation of bleeding.

  6. Correlation between Acute Coronary Syndrome Classification and Multi-detector CT Characterization of Plaque

    Institute of Scientific and Technical Information of China (English)

    Zhi-guo Wang; Lu-yue Gai; Jing-jing Gai; Ping Li; Xia Yang; Qin-hua Jin; Yun-dai Chen; Zhi-jun Sun; Zhi-wei Guan

    2011-01-01

    Objective To determine if multi-detector CT (MDCT) characterization of plaque is correlated with the classification of acute coronary syndrome (ACS). Methods Altogether 1900 patients were examined by MDCT from December 2007 to May 2009,of whom 95 patients fulfilled the criteria of ACS. Those patients were divided into the discrete plaque group (n=61) and diffuse plaque group (n=34) based on the findings in MDCT. The clinical diagnosis of ACS and CT results were analyzed, including segment stenosis score, segment involvement score, 3-vessel plaque score, left main score, calcification score, and remodeling index. The incidences of major adverse cardiac events in follow-up period were also recorded.Results The patients of the diffuse plaque group were older than those of the discrete plaque group (P<0.0001). The diffuse plaque group presented more cases of hypertension, peripheral artery disease, diabetes, and heart failure than discrete plaque group (all P<0.05). All the 5 patients with ST-segment elevation myocardial infarction were found in discrete plaque group. The segment stenosis score of the discrete plaque group was lower than that of the diffuse plaque group (5.15+3.55 vs. 14.91+5.37, P<0.001). The other four scores demonstrated significant inter-group difference as well (all P<0.05). The remodeling index of the discrete plaque group was higher (1.12+0.16 vs. 0.97+0.20, P<0.05). Follow-up data showed that major adverse cardiac events occurred more frequently in diffuse plaque group than in discrete group (29.41% vs.11.48%, P=0.0288).Conclusions Characteristics of discrete and diffuse plaques may be significandy different among different classes of ACS. The diffuse plaque may present higher risk, correlated to higher mortality. The diagnosis of discrete and diffuse plaques by MDCT would provide a new insight into the prognosis and treatment of ACS.

  7. 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.)

  8. 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.)

  9. Evaluation of accuracy of 3D reconstruction images using multi-detector CT and cone-beam CT

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Mi Ja [Graduate School of Clinical Dentistry, Hallym University, Seoul (Korea, Republic of); Huh, Kyung Hoe; Yi, Won Jin; Heo, Min Suk; Lee, Sam Sun; Choi, Soon Chul [School of Dentistry, Seoul National University, Seoul (Korea, Republic of)

    2012-03-15

    This study was performed to determine the accuracy of linear measurements on three-dimensional (3D) images using multi-detector computed tomography (MDCT) and cone-beam computed tomography (CBCT). MDCT and CBCT were performed using 24 dry skulls. Twenty-one measurements were taken on the dry skulls using digital caliper. Both types of CT data were imported into OnDemand software and identification of landmarks on the 3D surface rendering images and calculation of linear measurements were performed. Reproducibility of the measurements was assessed using repeated measures ANOVA and ICC, and the measurements were statistically compared using a Student t-test. All assessments under the direct measurement and image-based measurements on the 3D CT surface rendering images using MDCT and CBCT showed no statistically difference under the ICC examination. The measurements showed no differences between the direct measurements of dry skull and the image-based measurements on the 3D CT surface rendering images (P>.05). Three-dimensional reconstructed surface rendering images using MDCT and CBCT would be appropriate for 3D measurements.

  10. 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.)

  11. Comparison of effective dose for imaging of mandible between multi-detector CT and cone-beam CT

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Dae Kyo; Lee, Sang Chul; Huh, Kyung Hoe; Yi, Won Jin; Lee, Sam Sun; Choi, Soon Chul [School of Dentistry, Seoul National University, Seoul (Korea, Republic of)

    2012-06-15

    The aim of this study was to compare the effective dose for imaging of mandible between multi-detector computed tomography (MDCT) and cone-beam computed tomography (CBCT). An MDCT with low dose technique was also compared with them. Thermoluminescent dosimeter (TLD) chips were placed at 25 organ sites of an anthropomorphic phantom. The mandible of the phantom was exposed using 2 different types of MDCT units (Somatom Sensation 10 for standard-dose MDCT, Somatom Emotion 6 for low-dose MDCT) and 3 different CBCT units (AZ3000CT, Implagraphy, and Kavo 3D eXaM). The radiation absorbed dose was measured and the effective dose was calculated according to the ICRP 2007 report. The effective dose was the highest for Somatom Sensation 10 (425.84 {mu}Sv), followed by AZ3000CT (332.4 {mu}Sv), Somatom Emotion 6 (199.38 {mu}Sv), and 3D eXaM (111.6 {mu}Sv); it was the lowest for Implagraphy (83.09 {mu}Sv). The CBCT showed significant variation in dose level with different device. The effective doses of MDCTs were not significantly different from those of CBCTs for imaging of mandible. The effective dose of MDCT could be markedly decreased by using the low-dose technique.

  12. 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

  13. The feasibility study of 80 kV in 128-slice MSCT pulmonary angiography

    International Nuclear Information System (INIS)

    Objective: To investigate the influence of 80 kV on dose reduction and image quality in 128-slice CT pulmonary angiography (CTPA) compared with the conventional 120 kV. Methods: Sixty patients suspected of pulmonary embolism (PE) who underwent CTPA were randomly divided into 80 kV and 120 kV groups by random digits table method. All the patients underwent CTPA with automatic tube current modulation. The values of volume CT dose index (CTDIvol),dose length product (DLP) were recorded and effective dose (E) was calculated. The attenuation was measured in central and peripheral pulmonary arteries as well as background noise (BN), then signal-to-noise-ratio (SNR) and contrast-to-noise-ratio (CNR) were calculated. The radiation exposure, pulmonary arterial enhancement, background noise, SNR, CNR and scores of image quality by a 5-point scale were compared between two groups. Results: E value was significantly lower at 80 kV [(0.99 ± 0.27) mSv] compared with 120 kV [(3.02 ± 0.87) mSv, t =12.281, P<0.05]. The mean attenuation value of pulmonary arteries as well as BN in 80 kV group were significantly higher than in 120 kV group (P<0.05). SNR and CNR did not differ significantly between two groups. No significant difference was detected on scores of image quality (P>0.05). Conclusions: The application of 80 kV protocol combined with automatic tube current modulation scanning in 128-slice MSCT pulmonary angiography could significantly reduce radiation dose compared with the conventional 120 kV protocol without deterioration in diagnostic image quality. (authors)

  14. Multi-detector CT enterography with iso-osmotic mannitol as oral contrast for detecting small bowel disease

    Institute of Scientific and Technical Information of China (English)

    Lian-He Zhang; Shi-Zheng Zhang; Hong-Jie Hu; Min Gao; Ming Zhang; Qian Cao; Qiao-wei Zhang

    2005-01-01

    AIM: To assess the feasibility and usefulness of multi-detector CT enterography with orally administered iso-osmotic mannitol as negative contrast in demonstrating small bowel disease.METHODS: Thirteen volunteers and 38 patients with various kinds of small bowel disease were examined. We administered about 1 500 mL iso-osmotic mannitol as negative contrast agent and then proceeded with helical CT scanning on a Siemens Sensation 16 scanner. All volunteers and patients were interviewed about their tolerance of the procedure. Two radiologists postprocessed imaging data with MPR, thin MIP, VRT and INSPACE when necessary and then interpreted the scans,and adequacy of luminal distention was evaluated on a four-point scale. Demonstration of features of various kinds of small bowel disease was analyzed.RESULTS: The taste of iso-osmotic mannitol is good (slightly sweet) and acceptable by all. Small bowel distention was excellent and moderate in most volunteers and patients. CT features of many kinds of diseases such as tumors, Crohn's disease,and small bowel obstruction,etc. were clearly displayed.CONCLUSION: Multi-detector CT enterography with iso-osmotic mannitol as negative contrast to distend the small bowel is a simple, rapid, noninvasive and effective method of evaluating small bowel disease.

  15. 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

  16. Correlation between 128-slice CT angiography of the anterior communicating artery complex variation and incidence of anterior communicating artery aneurysm%前交通动脉复合体变异的128排CT血管成像及其与前交通动脉瘤发病的相关性

    Institute of Scientific and Technical Information of China (English)

    张鹏举

    2012-01-01

    目的 探讨前交通动脉复合体变异的128排CT血管成像的影像表现及其与前交通动脉瘤发病的相关性.方法 选择本院行CT颅脑血管成像的患者60例,其中前交通动脉瘤患者26例(研究组),无交通动脉瘤患者34例(对照组),比较两组患者前交通动脉及与其相连的A1段的造影表现差异,分析前交通动脉瘤的发病与交通动脉复合体变异的关系.结果 ①两组A1段形态表现主要为直线型和成窗形,其中直线型共54例(研究组24例,对照组30例),成窗型6例(研究组2例,对照组4例),两组A1段分型比较差异无统计学意义(P>0.05).②两组共发生A1段变异21例,其中左侧优势14例(研究组10例,对照组4例),右侧优势7例(研究组2例,对照组5例),研究组A1段变异左侧优势发生率明显高于对照组及本组右侧优势发生率(P<0.05).③研究组前交通动脉变异率明显高于对照组,两组差异有统计学意义(P<0.05).结论 128排颅脑CT血管成像可以清晰显示前交通动脉复合体的变异情况,并且复合体的变异与前交通动脉瘤的发生有重要关系.%Objective To explore the 128-slice CT anglography of the anterior communicating artery complex variation and its correlation with incidence of anterior communicating artery aneurysm. Methods 60 cases of patients underwent. CT brain angiograpby in our hospital were selected, 26 cases (study group) with anterior communicating artery aneurysm, 34 patients (control group) with no anterior communicating artery aneurysm, imaging performance of anterior communicating artery and anterior cerebral artery Al pail of two groups were compared, the relationship between anterior communicating artery aneurysm communicating and communicating arteiy complex variation was analyzed. Results vlJ'Al segment, manifestations of two groups main were straight and the window-shaped, of which 54 cases (24 cases of study group, 30 cases of control group) were straight, 6 cases

  17. Improving Image Quality of On-Board Cone-Beam CT in Radiation Therapy Using Image Information Provided by Planning Multi-Detector CT: A Phantom Study

    OpenAIRE

    Yang, Ching-Ching; Chen, Fong-Lin; Lo, Yeh-Chi

    2016-01-01

    Purpose The aim of this study was to improve the image quality of cone-beam computed tomography (CBCT) mounted on the gantry of a linear accelerator used in radiation therapy based on the image information provided by planning multi-detector CT (MDCT). Methods MDCT-based shading correction for CBCT and virtual monochromatic CT (VMCT) synthesized using the dual-energy method were performed. In VMCT, the high-energy data were obtained from CBCT, while the low-energy data were obtained from MDCT...

  18. 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

  19. Evaluation of the effective dose and image quality of low-dose multi-detector CT for orthodontic treatment planning

    International Nuclear Information System (INIS)

    This study was designed to compare the effective doses from low-dose and standard-dose multi-detector CT (MDCT) scanning protocols and evaluate the image quality and the spatial resolution of the low-dose MDCT protocols for clinical use. 6-channel MDCT scanner (Siemens Medical System, Forschheim, Germany), was used for this study. Protocol of the standard-dose MDCT for the orthodontic analysis was 130 kV, 35 mAs, 1.25 mm slice width, 0.8 pitch. Those of the low-dose MDCT for orthodontic analysis and orthodontic surgery were 110 kV, 30 mAs, 1.25 mm slice width, 0.85 pitch and 110 kV, 45 mAs, 2.5 mm slice width, 0.85 pitch. Thermoluminescent dosimeters (TLDs) were placed at 31 sites throughout the levels of adult female ART head and neck phantom. Effective doses were calculated according to ICRP 1990 and 2007 recommendations. A formalin-fixed cadaver and AAPM CT performance phantom were scanned for the evaluation of subjective image quality and spatial resolution. Effective doses in μSv (E2007) were 699.1, 429.4 and 603.1 for standard-dose CT of orthodontic treatment, low-dose CT of orthodontic analysis, and low-dose CT of orthodontic surgery, respectively. The image quality from the low-dose protocol were not worse than those from the standard-dose protocol. The spatial resolutions of both standard-dose and low-dose CT images were acceptable. From the above results, it can be concluded that the low-dose MDCT protocol is preferable in obtaining CT images for orthodontic analysis and orthodontic surgery.

  20. Assessment of the anterior spinal artery and the artery of Adamkiewicz using multi-detector CT angiography

    Institute of Scientific and Technical Information of China (English)

    ZHAO Shao-hong; Laura Logan; Pamela Schraedley; Geoffrey D. Rubin

    2009-01-01

    Background Damage to the spinal cord after the treatment of the descending thoracic and thoracoabdominal aortic aneurysms is an uncommon but devastating complication. The artery of Adamkiewicz (AKA) is the principal arterial supply of the anterior spinal artery (ASA) in the lower thoracic and lumbar level. The purpose of this study was to evaluate the visualization of the anterior spinal artery and the artery of Adamkiewicz, the affecting factors for the detection rate using multi-detector row CT (MDCT). Methods Ninety-nine consecutive patients (31 women and 68 men; age range, 25-90 years; average age 61.3 years), with suspicion for thoracic aortic lesions necessitating surgical intervention (31 aortic aneurysm, 45 dissection, 5 intramural hematoma, and 18 normal), underwent CT angiography from the aortic arch to the aortic bifurcation. Transverse sections, multiplanar reformations and thin maximum intensity projections were used to assess the ASA and AKA. The level of the ASA and AKA origins and CT acquisition parameters were recorded. The contrast-to-noise ratio of the image, an index of the mass of the T11 body (vertebral mass index), the subcutaneous fat thickness, and the CT value within the aortic arch and at the T11 level were measured. The detection of the ASA and AKA were evaluated relative to the acquisition parameters, scan characteristics, and aortic lesion type. Differences were assessed with the Wilcoxon rank-sum and t tests. Results The ASA was visualized in 51 patients (52%) and the AKA in 18 patients (18%). The ASA was identified in 36/67 patients (54%) with 1.25 mm thickness and in 15/32 patients (47%) with 2.5-3.0 mm thickness. This difference did not achieve significance (P=0.13). The detection rate of the ASA and the AKA was influenced by the vertebral mass index and the contrast-to-noise ratio (P<0.05). The amount of subcutaneous fat affected the detection rate of the ASA (P <0.05) but not the AKA. In CT scans of ASA detection, the mean CT

  1. 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)

  2. A retrospective comparison of smart prep and test bolus multi-detector CT pulmonary angiography protocols

    International Nuclear Information System (INIS)

    Optimal arterial opacification is crucial in imaging the pulmonary arteries using computed tomography (CT). This poses the challenge of precisely timing data acquisition to coincide with the transit of the contrast bolus through the pulmonary vasculature. The aim of this quality assurance exercise was to investigate if a change in CT pulmonary angiography (CTPA) scanning protocol resulted in improved opacification of the pulmonary arteries. Comparison was made between the smart prep protocol (SPP) and the test bolus protocol (TBP) for opacification in the pulmonary trunk. A total of 160 CTPA examinations (80 using each protocol) performed between January 2010 and February 2011 were assessed retrospectively. CT attenuation coefficients were measured in Hounsfield Units (HU) using regions of interest at the level of the pulmonary trunk. The average pixel value, standard deviation (SD), maximum, and minimum were recorded. For each of these variables a mean value was then calculated and compared for these two CTPA protocols. Minimum opacification of 200 HU was achieved in 98% of the TBP sample but only 90% of the SPP sample. The average CT attenuation over the pulmonary trunk for the SPP was 329 (SD = ±21) HU, whereas for the TBP it was 396 (SD = ±22) HU (P = 0.0017). The TBP also recorded higher maximum (P = 0.0024) and minimum (P = 0.0039) levels of opacification. This study has found that a TBP resulted in significantly better opacification of the pulmonary trunk than the SPP

  3. A retrospective comparison of smart prep and test bolus multi-detector CT pulmonary angiography protocols

    Energy Technology Data Exchange (ETDEWEB)

    Suckling, Tara [Medical Imaging Department, Tamworth Rural Referral Hospital, Tamworth, New South Wales (Australia); Smith, Tony [University Department of Rural Health, The University of Newcastle, Tamworth, New South Wales (Australia); Reed, Warren [Discipline of Medical Radiation Sciences, The University of Sydney, Lidcombe (Australia); Medical Imaging Department, Tamworth Rural Referral Hospital, Tamworth, New South Wales (Australia)

    2013-06-15

    Optimal arterial opacification is crucial in imaging the pulmonary arteries using computed tomography (CT). This poses the challenge of precisely timing data acquisition to coincide with the transit of the contrast bolus through the pulmonary vasculature. The aim of this quality assurance exercise was to investigate if a change in CT pulmonary angiography (CTPA) scanning protocol resulted in improved opacification of the pulmonary arteries. Comparison was made between the smart prep protocol (SPP) and the test bolus protocol (TBP) for opacification in the pulmonary trunk. A total of 160 CTPA examinations (80 using each protocol) performed between January 2010 and February 2011 were assessed retrospectively. CT attenuation coefficients were measured in Hounsfield Units (HU) using regions of interest at the level of the pulmonary trunk. The average pixel value, standard deviation (SD), maximum, and minimum were recorded. For each of these variables a mean value was then calculated and compared for these two CTPA protocols. Minimum opacification of 200 HU was achieved in 98% of the TBP sample but only 90% of the SPP sample. The average CT attenuation over the pulmonary trunk for the SPP was 329 (SD = ±21) HU, whereas for the TBP it was 396 (SD = ±22) HU (P = 0.0017). The TBP also recorded higher maximum (P = 0.0024) and minimum (P = 0.0039) levels of opacification. This study has found that a TBP resulted in significantly better opacification of the pulmonary trunk than the SPP.

  4. 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.)

  5. 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.)

  6. Multi-detector spiral CT study of the relationships between pulmonary ground-glass nodules and blood vessels

    Energy Technology Data Exchange (ETDEWEB)

    Gao, Feng; Li, Ming; Ge, Xiaojun; Ren, Qingguo; Hua, Yanqing [Huadong Hospital Fudan University, Department of Radiology, Shanghai (China); Zheng, Xiangpeng [Huadong Hospital Fudan University, Department of Radiation Oncology, Shanghai (China); Chen, Yan [Huadong Hospital Fudan University, Department of Pathology, Shanghai (China); Lv, Fangzhen [Huadong Hospital Fudan University, Department of Thoracic Surgery, Shanghai (China)

    2013-12-15

    To investigate the relationships between pulmonary ground-glass nodules (GGN) and blood vessels and their diagnostic values in differentiating GGNs. Multi-detector spiral CT imaging of 108 GGNs was retrospectively reviewed. The spatial relationships between GGNs and supplying blood vessels were categorized into four types: I, vessels passing by GGNs; II, intact vessels passing through GGNs; III, distorted, dilated or tortuous vessels seen within GGNs; IV, more complicated vasculature other than described above. Relationship types were correlated to pathologic and/or clinical findings of GGNs. Of 108 GGNs, 10 were benign, 24 preinvasive nodules and 74 adenocarcinomas that were pathologically proven. Types I, II, III and IV vascular relationships were observed in 9, 58, 21 and 20 GGNs, respectively. Type II relationship was the dominating relationship for each GGN group, but significant differences were shown among them. Correlation analysis showed strong correlation between invasive adenocarcinoma and type III and IV relationships. Subgroup analysis indicated that type III was more commonly seen in IAC with comparison to type IV more likely seen in MIA. Different GGNs have different relationships with vessels. Understanding and recognising characteristic GGN-vessel relationships may help identify which GGNs are more likely to be malignant. (orig.)

  7. In vitro evaluation of 56 coronary artery stents by 256-slice multi-detector coronary CT

    Energy Technology Data Exchange (ETDEWEB)

    Steen, Henning, E-mail: henning.steen@med.uni-heidelberg.de [University of Heidelberg, Department of Cardiology, Im Neuenheimer Feld 410, Heidelberg 69120 (Germany); Andre, Florian, E-mail: Florian.Andre@med.uni-heidelberg.de [University of Heidelberg, Department of Cardiology, Im Neuenheimer Feld 410, Heidelberg 69120 (Germany); Korosoglou, Grigorios, E-mail: Grigorios.Korosoglou@med.uni-heidelberg.de [University of Heidelberg, Department of Cardiology, Im Neuenheimer Feld 410, Heidelberg 69120 (Germany); Mueller, Dirk, E-mail: Dirk.Mueller@philips.com [Philips GmbH Healthcare Division, Luebeckertordamm 5, Hamburg 20099 (Germany); Hosch, Waldemar, E-mail: Waldemar.Hosch@med.uni-heidelberg.de [University of Heidelberg, Department of Diagnostic and Interventional Radiology, Im Neuenheimer Feld 410, Heidelberg 69120 (Germany); Kauczor, Hans-Ulrich, E-mail: Hans-Ulrich.Kauczor@med.uni-heidelberg.de [University of Heidelberg, Department of Diagnostic and Interventional Radiology, Im Neuenheimer Feld 410, Heidelberg 69120 (Germany); Giannitsis, Evangelos, E-mail: Evangelos.Giannitsis@med.uni-heidelberg.de [University of Heidelberg, Department of Cardiology, Im Neuenheimer Feld 410, Heidelberg 69120 (Germany); Katus, Hugo A., E-mail: Hugo.Katus@med.uni-heidelberg.de [University of Heidelberg, Department of Cardiology, Im Neuenheimer Feld 410, Heidelberg 69120 (Germany)

    2011-10-15

    Objective: We sought to investigate stent lumen visibility of 56 coronary stents with the newest 256-multi-slice-CT (256-MDCT) technology for different reconstruction algorithms in an in vitro model. Background: Early identification of in-stent restenosis (ISR) is important to avoid recurrent ischemia and prevent acute myocardial infarction (AMI). Since angiography has the disadvantage of high costs and its invasiveness, MDCT could be a convenient and safe non-invasive alternative for detection of ISR. Material and methods: Percentages of in-stent lumen diameter and in-stent signal attenuation (measured as contrast-to-noise ratio (CNR)) of 56 coronary stents (group A {<=}2.5 mm; group B = 2.75-3.0 mm; group C = 3.5-4.0 mm) were evaluated in a coronary vessel in vitro phantom (iodine-filled plastic tubes) employing four different reconstruction algorithms (XCD, CC, CD, XCB) on a novel 256-MDCT (Philips-iCT, collimation = 128 mm x 0.625 mm; rotation time = 270 ms; tube current = 800 mA s with 120 kV). Analysis was conducted with the semi-automatical full-width-at-half-maximum (FWHM) method. P-values <0.05 were regarded statistically significant. Results: In-stent lumen diameter >60% for group C stents was significantly larger and CNR was significantly lower (both p < 0.05) for sharp kernels (CD; XCD) when compared to groups A/B. The FWHM-method showed significantly smaller in-stent lumen diameter (p < 0.05) when compared to the manual method. Conclusion: 256-MDCT could potentially be employed for clinical assessment of stent patency in stents >3.0 mm when analysed with cardio-dedicated sharp kernels, although clinical studies corroborating this claim should be performed. However, stents {<=}3.0 mm reconstructed by soft kernels revealed insufficient in-stent lumen visualisation and should not be used in clinical practice. Further improvements in spatial and temporal image resolution as well as reductions of radiation exposure and image noise have to be accomplished

  8. 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

  9. 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.

  10. 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)

  11. Comparison of two-dimensional CT with virtual gastrography using multi-detector CT in the diagnosis of early gastric cancer

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jee Eun; Eun, Hyo Won [Ewha Womans University Dongdaemoon Hospital, Seoul (Korea, Republic of); Kim, Jung Hoon [Soon Chun Hyan University Hospital, Seoul (Korea, Republic of)

    2006-12-15

    We compared the performance of virtual gastrography (VG) using multi-detector (MDCT) with two-dimensional (2D) in the diagnosis of early gastric cancer (EGC). We performed conventional gastroscopy and MDCT examination after gaseous distension of the stomach in 50 consecutive patients who were confirmed as EGC by surgery and endoscopic mucosal resection. Unenhanced images were obtained in the prone position and contrast enhanced images were obtained in the supine position. Contrast enhanced imaging was done 70 seconds after intravenous injection of 150 mL of ionic contrast material at the rate of 3 mL/sec. 2D CT and VG images were analyzed by two radiologist with consensus to assess the location and gross morphologic type of EGC. Crosstabs were used to determine the diagnostic accuracy of EGC on 2D CT and VG. The diagnostic specificity for 50 patients with EGC was significantly higher with VG (72%) than with 2D CT (88%) ({rho} < ). VG depicted EGC in eight patients (type I = 1; type IIa = 3; type IIb 1; type IIc = 2; type IIa + IIc = 1) that were missed on the 2D CT. The lesions were located in the antrum (n = 6), angle (n = 1), and body (n = 1). However, VG frequently misdiagnosed EGCs of type IIb (n = 4), IIc (n = 1), and III (n = 1), as well as the location at the angle (n = 3), antrum (n 1), and body (n = 1). VG showed excellent result in the detection of EGC compared with 2D CT. However, it had limitations in the diagnosis of EGC type IIb or gastric angle tumor.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-03-15

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

  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. Multi-detector CT-colonography in inflammatory bowel disease: Prospective analysis of CT-findings to high-resolution video colonoscopy

    Energy Technology Data Exchange (ETDEWEB)

    Andersen, Kjel [Institute of Diagnostic Radiology, University Hospital Duesseldorf (Germany)]. E-mail: kjel_andersen@web.de; Vogt, Christoph [Department of Gastroenterology, Hepatology and Infectiology, University Hospital Duesseldorf (Germany); Blondin, Dirk [Institute of Diagnostic Radiology, University Hospital Duesseldorf (Germany); Beck, Andreas [Institute of Informatics, Heinrich-Heine-University, Duesseldorf (Germany); Heinen, Wolfram [Institute of Diagnostic Radiology, University Hospital Duesseldorf (Germany); Aurich, Volker [Institute of Informatics, Heinrich-Heine-University, Duesseldorf (Germany); Haeussinger, Dieter [Department of Gastroenterology, Hepatology and Infectiology, University Hospital Duesseldorf (Germany); Moedder, Ulrich [Institute of Diagnostic Radiology, University Hospital Duesseldorf (Germany); Cohnen, Mathias [Institute of Diagnostic Radiology, University Hospital Duesseldorf (Germany)

    2006-04-15

    Aim: Prospective analysis of multi-detector CT-colonography (MDCTC) in patients with inflammatory bowel disease (IBD) compared to high-resolution video-endoscopy (HRVC). Materials and methods: Twenty-one patients (mean age 49.6 years) with Crohn's disease or ulcerative colitis underwent MDCTC (Somatom Volume Zoom, Siemens, Erlangen; 1 mm collimation, Pitch 8, 100 mAs, 120 kVp). HRVC was performed within 2 h after MDCTC. MDCTC was analyzed by two blinded readers. MDCTC-findings including bowel wall alterations and extraintestinal changes were compared to results of HRVC. Results: Over-all-sensitivity was 100% for endoluminal lesions with correct diagnosis of two cancers. Acute and chronic IBD were correctly identified by MDCTC in 63.6%, and 100%, respectively, with a specificity of 75%, and 100%. Sensitivity, specificity, positive and negative predictive values of MDCTC for diagnosis of acute and chronic disease were best for chronic disease. Sensitivity was worst for acute ulcerative colitis and specificity was worst for acute Crohn's disease. Haustral loss was seen only in ulcerative colitis. Pseudopolyps and fistulae were findings exclusive to Crohn's disease. Particularly extraintestinal findings as increased vascularization and local lymphadenopathy correlated well with endoscopic definition of acute disease. Because of the possibly more vulnerable colonic wall in acute inflammatory bowel disease, the air inflation for MDCTC should be performed most carefully to avoid any risk of colonic perforation. Conclusion: MDCTC may help to distinguish between patients with acute and chronic IBD. Especially extraintestinal complications, tumorous as well as pseudo-tumorous lesions can be detected with high sensitivity and specificity.

  15. Detection of blebs and bullae in patients with primary spontaneous pneumothorax by multi-detector CT reconstruction using different slice thicknesses

    International Nuclear Information System (INIS)

    The aim of this study was to compare the diagnostic performances of multi-detector computed tomography (MDCT) reconstruction at two different slice thicknesses (1mm, 'high resolution' vs. 5mm, 'routine') with respect to the detection of blebs and bullae (BBs) in patients with primary spontaneous pneumothorax (PSP). Thirty-one patients underwent wedge resection of BBs (29 unilateral and 2 bilateral) for PSP from January 2010 to January 2013. Two observers assessed the presence and locations of BBs independently using high-resolution CT (HRCT) and routine CT reconstruction, and compared the sensitivities of each reconstruction method for BB detection using operative findings as a standard reference. In addition, the number of BBs in each CT image set was recorded and inter-observer agreements were evaluated. Sensitivity for the detection of BBs was significantly better for HRCT than routine CT (97.0% vs. 63.6% for observer 1 and 94.0% vs. 57.6% for observer 2, respectively, both P-values<0.001). On a per-bleb and a per-bulla basis, inter-observer agreements regarding BBs by HRCT were good and very good (k=0.66 and 0.94, respectively) and superior to those determined by routine CT (k=0.59 and 0.60, respectively). Different slice thickness reconstructions influence the diagnostic efficacy of MDCT for the detection of BBs in patients with PSP. High-resolution thin slice CT reconstruction was found to have a significantly greater sensitivity than routine thicker slice thickness reconstruction for the detection of BBs.

  16. The effects of emphysema on airway disease: Correlations between multi-detector CT and pulmonary function tests in smokers

    Energy Technology Data Exchange (ETDEWEB)

    Yahaba, Misuzu, E-mail: mis_misuzu@yahoo.co.jp; Kawata, Naoko, E-mail: chumito_03@yahoo.co.jp; Iesato, Ken, E-mail: iesato_k@yahoo.co.jp; Matsuura, Yukiko, E-mail: matsuyuki_future@yahoo.co.jp; Sugiura, Toshihiko, E-mail: sugiura@js3.so-net.ne.jp; Kasai, Hajime, E-mail: daikasai6075@yahoo.co.jp; Sakurai, Yoriko, E-mail: yoliri@nifty.com; Terada, Jiro, E-mail: jirotera@chiba-u.jp; Sakao, Seiichiro, E-mail: sakao@faculty.chiba-u.jp; Tada, Yuji, E-mail: ytada@faculty.chiba-u.jp; Tanabe, Nobuhiro, E-mail: ntanabe@faculty.chiba-u.jp; Tatsumi, Koichiro, E-mail: tatsumi@faculty.chiba-u.jp

    2014-06-15

    Background: Chronic obstructive pulmonary disease (COPD) is characterized by airflow limitation caused by emphysema and small airway narrowing. Quantitative evaluation of airway dimensions by multi-detector computed tomography (MDCT) has revealed a correlation between airway dimension and airflow limitation. However, the effect of emphysema on this correlation is unclear. Objective: The goal of this study was to determine whether emphysematous changes alter the relationships between airflow limitation and airway dimensions as measured by inspiratory and expiratory MDCT. Methods: Ninety-one subjects underwent inspiratory and expiratory MDCT. Images were evaluated for mean airway luminal area (Ai), wall area percentage (WA%) from the third to the fifth generation of three bronchi (B1, B5, B8) in the right lung, and low attenuation volume percent (LAV%). Correlations between each airway index and airflow limitation were determined for each patient and compared between patients with and without evidence of emphysema. Results: In patients without emphysema, Ai and WA% from both the inspiratory and expiratory scans were significantly correlated with FEV{sub 1.} No correlation was detected in patients with emphysema. In addition, emphysematous COPD patients with GOLD stage 1 or 2 disease had significantly lower changes in B8 Ai than non-emphysematous patients. Conclusions: A significant correlation exists between airway parameters and FEV{sub 1} in patients without emphysema. Emphysema may influence airway dimensions even in patients with mild to moderate COPD.

  17. Cardiac Multi-detector CT Segmentation Based on Multiscale Directional Edge Detector and 3D Level Set.

    Science.gov (United States)

    Antunes, Sofia; Esposito, Antonio; Palmisano, Anna; Colantoni, Caterina; Cerutti, Sergio; Rizzo, Giovanna

    2016-05-01

    Extraction of the cardiac surfaces of interest from multi-detector computed tomographic (MDCT) data is a pre-requisite step for cardiac analysis, as well as for image guidance procedures. Most of the existing methods need manual corrections, which is time-consuming. We present a fully automatic segmentation technique for the extraction of the right ventricle, left ventricular endocardium and epicardium from MDCT images. The method consists in a 3D level set surface evolution approach coupled to a new stopping function based on a multiscale directional second derivative Gaussian filter, which is able to stop propagation precisely on the real boundary of the structures of interest. We validated the segmentation method on 18 MDCT volumes from healthy and pathologic subjects using manual segmentation performed by a team of expert radiologists as gold standard. Segmentation errors were assessed for each structure resulting in a surface-to-surface mean error below 0.5 mm and a percentage of surface distance with errors less than 1 mm above 80%. Moreover, in comparison to other segmentation approaches, already proposed in previous work, our method presented an improved accuracy (with surface distance errors less than 1 mm increased of 8-20% for all structures). The obtained results suggest that our approach is accurate and effective for the segmentation of ventricular cavities and myocardium from MDCT images. PMID:26319010

  18. The effects of emphysema on airway disease: Correlations between multi-detector CT and pulmonary function tests in smokers

    International Nuclear Information System (INIS)

    Background: Chronic obstructive pulmonary disease (COPD) is characterized by airflow limitation caused by emphysema and small airway narrowing. Quantitative evaluation of airway dimensions by multi-detector computed tomography (MDCT) has revealed a correlation between airway dimension and airflow limitation. However, the effect of emphysema on this correlation is unclear. Objective: The goal of this study was to determine whether emphysematous changes alter the relationships between airflow limitation and airway dimensions as measured by inspiratory and expiratory MDCT. Methods: Ninety-one subjects underwent inspiratory and expiratory MDCT. Images were evaluated for mean airway luminal area (Ai), wall area percentage (WA%) from the third to the fifth generation of three bronchi (B1, B5, B8) in the right lung, and low attenuation volume percent (LAV%). Correlations between each airway index and airflow limitation were determined for each patient and compared between patients with and without evidence of emphysema. Results: In patients without emphysema, Ai and WA% from both the inspiratory and expiratory scans were significantly correlated with FEV1. No correlation was detected in patients with emphysema. In addition, emphysematous COPD patients with GOLD stage 1 or 2 disease had significantly lower changes in B8 Ai than non-emphysematous patients. Conclusions: A significant correlation exists between airway parameters and FEV1 in patients without emphysema. Emphysema may influence airway dimensions even in patients with mild to moderate COPD

  19. 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.

  20. Multi-detector computed tomography in non-traumatic urologic emergencies; Multidetektor-CT bei nichttraumatischen urologischen Notfaellen

    Energy Technology Data Exchange (ETDEWEB)

    Scherr, M.K. [Ludwig-Maximilians-Universitaet Muenchen (Germany). Institut fuer Klinische Radiologie

    2009-06-15

    Today's modern multi-detector computer tomography (MDCT) with its fast gantry rotation enables scanning of large body volumes with high temporal and spatial resolution. The fast acquisition of data and subsequent data reconstruction enables multiphase protocols with short time gaps between consecutive scan series so that large numbers of scans within one respiratory pause are possible and even in cases of non-cooperative patients acceptable quality of image data is provided. The acquired thin-slice raw data with isotropic submillimeter voxels can be visualized with different reconstruction algorithms. The aadvantages of imaging for diagnostics in urologic emergencies are the excellent visualization of acute arterial and venous pathologies, detailed assessment of renal parenchyma and the precise depiction of the urinary tract. In non-trauma settings this enables detailed visualization of inflammatory diseases and differentiation of obstructive or post-therapeutic pathologies along the upper and lower urinary tract. Based on these MDCT findings adequate therapy planning and planning of interventional or surgical procedures can be carried out. (orig.) [German] Durch den Einsatz moderner Multidetektor-Computertomographen (MDCT) mit schnellen Gantryrotationszeiten sind heute grosse Scanvolumina in hoher zeitlicher und mit hoher raeumlicher Aufloesung moeglich. Die schnelle Bilddatenakquisition und -verarbeitung ermoeglichen Mehrphasenprotokolle mit mehreren kurz aufeinander folgenden Scanserien innerhalb jeweils eines Atemanhalts und eine akzeptable Bildqualitaet bei unkooperativen Patienten. Diese fuehren zu duennschichtigen Rohdaten mit isotropen Voxel im Submillimeterbereich, die mit verschiedenen Nachrekonstruktionsverfahren optimal visualisiert werden koennen. Die urologische Notfalldiagnostik profitiert hier von der hervorragenden Darstellbarkeit akuter Gefaesspathologien in der arteriellen und venoesen Vaskularisation der Nieren. Die renale

  1. Usefulness of multi-detector CT in boyd-Griffin type 2 intertrochanteric fractures with clinical correlation

    Energy Technology Data Exchange (ETDEWEB)

    Han, Suk-Ku; Choi, Nam-Yong [College of Medicine, Catholic University of Korea, Department of Orthopaedic Surgery, St. Paul' s Hospital, Seoul (Korea); Lee, Bae-Young; Kim, Yong-Sik [College of Medicine, Catholic University of Korea, Department of Radiology, St. Paul' s Hospital, Seoul (Korea)

    2010-06-15

    To investigate the usefulness of multi-detector computed tomography (MDCT) in three-part intertrochanteric fractures of proximal femur. Twenty-six patients with Boyd-Griffin type 2 intertrochanteric fractures with MDCT (group 1) and 36 patients of the same type fracture without MDCT (group 2) were compared. Lesser trochanter (LT)/greater trochanter (GT) volume ratio above 0.5 or the volumetric proportion of GT in total volume of proximal femur below 25% was considered an unstable fracture. The fractures were fixed with dynamic compression hip screws (DCS). Additional greater trochanter stabilizing (GTS) plate or bone cement augmentation of the femoral head was performed in unstable fractures. Clinical outcome between the two groups by fixation failure and radiological results was compared. The volume ratio of the LT/GT was 0.33 (range, 0.13-0.73). The volume of the LT was inversely correlated with that of the GT (p < 0.001). The volume of the GT was significantly correlated with the LT/GT ratio or the head and neck (HN)/GT ratio (p < 0.001). Seven cases were regarded as unstable fractures in group 1. Fixation failures happened in one case in group 1 and five cases in group 2. There was significantly lower failure rate in group 1 than group 2 (p=0.03). Neck-shaft angle at last follow-up was 134.8 {+-} 5.3 in group 1 and 131.3 {+-} 5.1 in group 2 (p = 0.01). The sliding length of lag screws were 5.6 {+-} 2.9 mm in group 1 and 8.3 {+-} 3.2 in group 2 (p=0.03). Preoperative use of MDCT provides useful information about the fracture pattern and the geometry of the proximal femur in unstable intertrochanteric fractures and helps surgical planning. The ratio of the LT to the GT is inversely correlated with fracture stability. (orig.)

  2. 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.)

  3. 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.)

  4. Can outer-to-outer diameter be used alone in diagnosing appendicitis on 128-slice MDCT?

    Institute of Scientific and Technical Information of China (English)

    Jamal; Yaqoob; Muhammad; Idris; Muhammad; Shahbaz; Alam; Nazia; Kashif

    2014-01-01

    AIM: To assess the frequency of visualization, position and diameter of normal appendix on 128-slice multidetector computed tomography(MDCT) in adult population.METHODS: Retrospective cross sectional study conducted at Radiology Department, Dallah Hospital, Riyadh, Saudi Arabia from March 2013 to October 2013. Non-enhanced computed tomography scans of abdomen and pelvis of 98 patients presenting with hematuria(not associated with abdominal pain, fever or colonic disease) were reviewed by two radiologists, blinded to patient history. The study group included 55 females and 43 males with overall mean age of 54.7 years(range 21 to 94 years). The coronal reformatted images were reviewed in addition to the axial images. The frequency of visualization of appendix was recorded with assessment of position, diameter and luminal contents.RESULTS: The appendix was recorded as definitely visualized in 99% of patients and mean outer-to-outer diameter of the appendix was 5.6 ± 1.3 mm(range 3.0-11.0 mm).CONCLUSION: MDCT with its multiplanar reformation display is extremely useful for visualization of normal appendix. The normal appendix is very variable in its position and diameter. In the absence of other signs, the diagnosis of acute appendix should not be made solely on outer-to-outer appendiceal diameter.

  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. Exposure (mAs) optimisation of a multi-detector CT protocol for hepatic lesion detection: are thinner slices better?

    International Nuclear Information System (INIS)

    The purpose of this work was to determine the exposure-optimised slice thickness for hepatic lesion detection with CT. A phantom containing spheres (diameter 9.5, 4.8 and 2.4mm) with CT density 10 HU below the background (50 HU) was scanned at 125, 100, 75 and 50 mAs. Data were reconstructed at 5-, 3- and 1-mm slice thicknesses. Noise, contrast-to-noise ratio (CNR), area under the curve (AUC) as calculated using receiver operating characteristic analysis and sensitivity representing lesion detection were calculated and compared. Compared with the 125 mAs/5mm slice thickness setting, significant reductions in AUC were found for 75 mAs (P<0.01) and 50 mAs (P<0.05) at 1- and 3-mm thicknesses, respectively; sensitivity for the 9.5-mm sphere was significantly reduced for 75 (P<0.05) and 50 mAs (P<0.01) at 1-mm thickness; sensitivity for the 4.8-mm sphere was significantly lower for 100, 75 and 50 mAs at all three slice thicknesses (P<0.05). The 2.4-mm sphere was rarely detected. At each slice thickness, noise at 100, 75 and 50 mAs exposures was approximately 10, 30 and 50% higher, respectively, than that at 125 mAs exposure. CNRs decreased in an irregular manner with reductions in exposure and slice thickness. This study demonstrated no advantage to using slices below 5mm thickness, and consequently thinner slices are not necessarily better.

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

    International Nuclear Information System (INIS)

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

  8. Evaluation of image quality and radiation dose at prospective ECG-triggered axial 256-slice multi-detector CT in infants with congenital heart disease

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Mei-ping; Liang, Chang-hong; Zhao, Zhen-jun; Liu, Hui; Li, Jing-lei; Zhang, Jin-e; Cui, Yan-hai; Yang, Lin; Liu, Qi-shun [Guangdong Academy of Medical Sciences, Guangdong General Hospital, Department of Radiology, Guangzhou (China); Ivanc, Thomas B.; Vembar, Mani [Philips Healthcare, CT Clinical Science, Highland Heights, OH (United States)

    2011-07-15

    There are a limited number of reports on the technical and clinical feasibility of prospective electrocardiogram (ECG)-gated multi-detector computed tomography (MDCT) in infants with congenital heart disease (CHD). To evaluate image quality and radiation dose at weight-based low-dose prospectively gated 256-slice MDCT angiography in infants with CHD. From November 2009 to February 2010, 64 consecutive infants with CHD referred for pre-operative or post-operative CT were included. All were scanned on a 256-slice MDCT system utilizing a low-dose protocol (80 kVp and 60-120 mAs depending on weight: 60 mAs for {<=}3 kg, 80 mAs for 3.1-6 kg, 100 mAs for 6.1-10 kg, 120 mAs for 10.1-15 kg). No serious adverse events were recorded. A total of 174 cardiac deformities, confirmed by surgery or heart catheterization, were studied. The sensitivity of MDCT for cardiac deformities was 97.1%; specificity, 99.4%; accuracy, 95.9%. The mean heart rate during scan was 136.7 {+-} 14.9/min (range, 91-160) with a corresponding heart rate variability of 2.8 {+-} 2.2/min (range, 0-8). Mean scan length was 115.3 {+-} 11.7 mm (range, 93.6-143.3). Mean volume CT dose index, mean dose-length product and effective dose were 2.1 {+-} 0.4 mGy (range, 1.5-2.8), 24.7 {+-} 5.9 mGy.cm (range, 14.7-35.8) and 1.6 {+-} 0.3 mSv (range, 1.1-2.5), respectively. Diagnostic-quality images were achieved in all cases. Satisfactory diagnostic quality for visualization of all/proximal/distal coronary artery segments was achieved in 88.4/98.8/80.0% of the scans. Low-dose prospectively gated axial 256-slice CT angiography is a valuable tool in the routine clinical evaluation of infants with CHD, providing a comprehensive three-dimensional evaluation of the cardiac anatomy, including the coronary arteries. (orig.)

  9. Multi-detector CT perfusion

    Directory of Open Access Journals (Sweden)

    Ashraf M. Enite

    2016-09-01

    Conclusion: CTP is a promising non-invasive technique assessing the efficacy, predicting early response to local treatment therapies and monitoring tumor recurrence. It assesses the degree of post therapy tumor perfusion especially the degree of arterialization.

  10. 药物性肝损害的多层螺旋CT影像表现%Drug-induced liver injury: spectrum of multi-detector spiral CT findings

    Institute of Scientific and Technical Information of China (English)

    宋文艳; 赵大伟; 陈煜; 刘旭华; 孟欣; 陈枫

    2010-01-01

    目的 探讨药物性肝损伤的MSCT表现.方法 回顾性分析2008年5月至2010年1月间经临床及病理证实的40例药物性肝损伤患者的MSCT影像及临床资料,总结其影像表现特征.结果 药物性肝损伤的MSCT影像表现主要有3种类型.(1)弥漫性肝脏损害2例:平扫肝脏密度均匀性减低,增强扫描肝实质轻度均匀强化.病理表现为肝细胞脂肪变性;混合炎性细胞浸润,点状坏死,毛细胆管淤胆.(2)灶性肝脏损害6例:肝内大片或多发小片状坏死灶5例.平扫肝脏密度不均匀,病变区为低密度改变;增强后病变区强化,特别是静脉期与平扫图像比较呈反转表现.另1例病程20 d的移植肝显示肝内弥漫的结节样再生.CT平扫可见肝内弥漫分布的稍高密度结节灶,增强后动脉期病灶强化,静脉期及延迟期近似于肝实质密度.5例患者病理表现为肝细胞片状及桥接坏死,大量混合炎性细胞浸润;1例重度淤胆,假小叶形成,肝细胞羽毛变性.(3)肝硬化表现2例:平扫肝脏表面呈结节状,肝叶比例失调,肝裂增宽.增强后肝脏强化一致,同时伴有脾大、腹水、侧支循环.病理为纤维组织增生,点状坏死和毛细胆管淤胆.结论 药物性肝损伤的MSCT影像表现具有一定的特征性,对临床诊断具有重要的参考价值.%Objective To demonstrate the spectrum of multi-detector spiral CT (MSCT) findings of drug-induced liver injury (DILI). Methods From May 2008 to January 2010, DILI was identified in 10 cases based on their clinical and pathological results. The spectrum of CT findings was analyzed retrospectively. Results According to the CT features, DILI were divided into three types. ( 1 ) Two cases presented diffuse hepatic injury, which appeared as homogeneous hypo-attenuation in precontrast CT scan and mild enhancement after contrast injection. The histopathological findings of the involved 1ivers include hepatocellular steatosis, neutrophil and

  11. 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。

  12. Monte Carlo simulations in multi-detector CT (MDCT) for two PET/CT scanner models using MASH and FASH adult phantoms

    Energy Technology Data Exchange (ETDEWEB)

    Belinato, W., E-mail: wbfisica@gmail.com [Bahia Federal Institute of Education, Science and Technology – IFBA, Vitória da Conquista, 45.100-000 (Brazil); Department of Physics, Federal University of Sergipe – UFS, São Cristóvão, 49.100-000 (Brazil); Santos, W.S. [Department of Physics, Federal University of Sergipe – UFS, São Cristóvão, 49.100-000 (Brazil); Paschoal, C.M.M., E-mail: cinthiam.paschoal@gmail.com [Department of Civil Engineering, Vale do Acarau State University – UVA, Sobral 62.040-730 (Brazil); Souza, D.N. [Department of Physics, Federal University of Sergipe – UFS, São Cristóvão, 49.100-000 (Brazil)

    2015-06-01

    The combination of positron emission tomography (PET) and computed tomography (CT) has been extensively used in oncology for diagnosis and staging of tumors, radiotherapy planning and follow-up of patients with cancer, as well as in cardiology and neurology. This study determines by the Monte Carlo method the internal organ dose deposition for computational phantoms created by multidetector CT (MDCT) beams of two PET/CT devices operating with different parameters. The different MDCT beam parameters were largely related to the total filtration that provides a beam energetic change inside the gantry. This parameter was determined experimentally with the Accu-Gold Radcal measurement system. The experimental values of the total filtration were included in the simulations of two MCNPX code scenarios. The absorbed organ doses obtained in MASH and FASH phantoms indicate that bowtie filter geometry and the energy of the X-ray beam have significant influence on the results, although this influence can be compensated by adjusting other variables such as the tube current–time product (mAs) and pitch during PET/CT procedures.

  13. Monte Carlo simulations in multi-detector CT (MDCT) for two PET/CT scanner models using MASH and FASH adult phantoms

    Science.gov (United States)

    Belinato, W.; Santos, W. S.; Paschoal, C. M. M.; Souza, D. N.

    2015-06-01

    The combination of positron emission tomography (PET) and computed tomography (CT) has been extensively used in oncology for diagnosis and staging of tumors, radiotherapy planning and follow-up of patients with cancer, as well as in cardiology and neurology. This study determines by the Monte Carlo method the internal organ dose deposition for computational phantoms created by multidetector CT (MDCT) beams of two PET/CT devices operating with different parameters. The different MDCT beam parameters were largely related to the total filtration that provides a beam energetic change inside the gantry. This parameter was determined experimentally with the Accu-Gold Radcal measurement system. The experimental values of the total filtration were included in the simulations of two MCNPX code scenarios. The absorbed organ doses obtained in MASH and FASH phantoms indicate that bowtie filter geometry and the energy of the X-ray beam have significant influence on the results, although this influence can be compensated by adjusting other variables such as the tube current-time product (mAs) and pitch during PET/CT procedures.

  14. Quantitative hepatic CT perfusion measurement: Comparison of Couinaud's hepatic segments with dual-source 128-slice CT

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Xuan [The Department of Radiology, Peking Union Medical College Hospital, Dongcheng District, Beijing, 100730 (China); Xue, Hua-dan, E-mail: bjdanna95@hotmail.com [The Department of Radiology, Peking Union Medical College Hospital, Dongcheng District, Beijing, 100730 (China); Jin, Zheng-yu, E-mail: jin_zhengyu@163.com [The Department of Radiology, Peking Union Medical College Hospital, Dongcheng District, Beijing, 100730 (China); Su, Bai-yan; Li, Zhuo; Sun, Hao; Chen, Yu; Liu, Wei [The Department of Radiology, Peking Union Medical College Hospital, Dongcheng District, Beijing, 100730 (China)

    2013-02-15

    Purpose: To compare the quantitative liver computed tomography perfusion (CTP) differences among eight hepatic segments. Materials and methods: This retrospective study was based on 72 acquired upper abdomen CTP scans for detecting suspected pancreas tumor. Patients with primary or metastatic liver tumor, any focal liver lesions except simple cyst (<3 cm in diameter), history of liver operation or splenectomy, evidence of liver cirrhosis or invasion of portal vein were excluded. The final analysis included 50 patients (M:F = 21:29, mean age = 43.2 years, 15–76 years). Arterial liver perfusion (ALP), portal-venous perfusion (PVP), total hepatic perfusion (THP = ALP + PVP), and hepatic perfusion index (HPI) of each hepatic segment were calculated and compared by means of one-way analysis of variance (ANOVA) and the Bonferonni correction method. Results: Compared to hepatic segments 5, 6, 7 and 8, segments 2 and 3 showed a tendency of higher ALPs, lower PVPs, and higher HPIs, most of which were statistically significant (p < 0.05). Hepatic segments 1 and 4 had higher mean values of ALP and HPI and lower mean values of PVP than segments 5, 6, 7 and 8 as well, although no significant differences were detected except for ALP and HPI for liver segments 1 and 7 (p = 0.001 and 0.035 respectively), and ALP for liver segments 1 and 5 (p = 0.039). Higher ALP and HPI were showed in hepatic segment 3 compared to segment 4 (p = 0.000 and 0.000 respectively). No significant differences were found for THP among eight segments. Conclusions: Intra-hepatic perfusion differences exist in normal hepatic parenchyma especially between lateral sector (segments 2 and 3) and right lobe (segments 5, 6, 7 and 8). This might have potential clinical significance in liver-perfusion-related protocol design and result analysis.

  15. Diagnostic Value of Brain Perfusion Imaging with 64 Multi-Detector Spiral CT in Early Cerebral Infarction%64排螺旋 CT 脑灌注成像对早期脑梗死的诊断价值

    Institute of Scientific and Technical Information of China (English)

    奚彬; 盛伟华; 唐建伟; 黄松; 宋黎涛

    2014-01-01

    目的:探讨64排螺旋 CT 脑灌注成像(CT perfusion imaging,CTP)对早期脑梗死的诊断价值。方法:临床拟诊早期脑梗死患者38例,均在症状出现24 h 内行头颅 CT 平扫及 CTP 检查。将脑梗死核心区、缺血半暗带(ischemic penumbra,IP)区与健侧对应区的情况做对比分析。结果:38例患者中,15例头颅 CT 平扫发现可疑脑梗死区,主要位于大脑半球,表现为密度轻度减低、局部脑沟稍变浅等;其余23例患者 CT 平扫未发现异常。38例患者的 CTP 检查均发现灌注异常区,表现为脑梗死区脑血流量(cerebral blood flow,CBF)与脑血容量(cerebral blood volume,CBV)均较健侧对应区明显下降,对比剂平均通过时间(mean transit time,MTT)较健侧对应区缩短,对比剂达峰时间(time to peak,TTP)较健侧对应区明显延长,差异均有统计学意义(P <0.01)。早期脑梗死患者 IP 区与梗死核心区比较,CBF、CBV、MTT 及 TTP 差异均有统计学意义(P <0.01);IP区与健侧对应区比较,CBF、MTT、TTP 差异均有统计学意义(P <0.05、0.01),CBV 差异无统计学意义(P >0.05)。获得随访的18例患者中,经积极溶栓等治疗后梗死区缩小6例,梗死区消失5例,仅表现为梗死区 TTP 和 MTT 延长、CBF 和 CBV 变化不大3例,梗死区无明显变化4例。结论:64排螺旋 CTP 检查可以准确地提示早期脑梗死。%Objective:To explore the diagnostic value of CT perfusion imaging(CTP)with 64 multi-detector spiral CT in early cerebral infarction.Methods:A total of 38 patients with suspected early cerebral infarction underwent plain CT and CTP within 24 h after the onset of related symptoms.The imaging results in infarction core area,ischemic penumbra (IP) and the contralateral normal region were comparatively analyzed.Results:Early cerebral infarction,mainly in cerebral hemispheres, were suspected

  16. 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.)

  17. Multi-detector thoracic CT findings in cerebro-costo-mandibular syndrome: rib gaps and failure of costo-vertebral separation

    Energy Technology Data Exchange (ETDEWEB)

    Watson, Tom Anthony; Arthurs, Owen John; Calder, Alistair Duncan [Great Ormond Street Hospital for Children NHS Foundation Trust, Department of Radiology, London (United Kingdom); Muthialu, Nagarajan [Great Ormond Street Hospital for Children NHS Foundation Trust, Department of Cardiothoracic surgery, London (United Kingdom)

    2014-02-15

    Cerebro-costo-mandibular syndrome (CCMS) describes a triad of mandibular hypoplasia, brain dysfunction and posterior rib defects (''rib gaps''). We present the CT imaging for a 2-year-old girl with CCMS that highlights the rib gap defects and shows absent transverse processes with abnormal fusion of the ribs directly to the vertebral bodies. We argue that this is likely to relate to abnormal lateral sclerotome development in embryology, with the failure of normal costo-vertebral junctions compounding impaired thoracic function. The case also highlights the use of CT for specific indications in skeletal dysplasia. (orig.)

  18. Multi-detector CT angiography for the assessment of anterior spinal artery and artery of Adamkiewicz patency in patients suspected of having thoracic aortic pathology

    Institute of Scientific and Technical Information of China (English)

    Shaohong ZHAO; Laura Logan; Pamela Schraedley; Geoffrey D.Rubin

    2006-01-01

    Objective To evaluate the visualization of the anterior spinal artery (ASA) and the artery of Adamkiewicz (AKA) as well as the affecting factors for the detection rate using multidetector row CT (MDCT). Methods Ninety-nine consecutive patients (31 women and 68 men; age range, 25-90 years; average age 61.3 years) with suspicion for thoracic aortic lesions necessitating surgical intervention (31 aortic aneurysm, 45 dissection, 5 intramural hematoma, and 18 normal), underwent 16-slice MDCT angiography from the aortic arch to the aortic bifurcation. Transverse sections, multiplanar reformations (MPR) and thin maximum intensity projections (MIP) were used to assess the ASA and AKA. The level of the ASA and AKA origins and CT acquisition parameters were recorded. The contrast-to-noise ratio (CNR) of the image, an index of the mass of the T11 body (vertebral mass index), the subcutaneous fat thickness,and the CT value within the aortic arch and at the T11 level were measured. The detection of the ASA and AKA was evaluated relative to the acquisition parameters, scan characteristics, and aortic lesion type. Differences were assessed with Wilcoxon rank-sum and t tests. Results The ASA was visualized in 51 patients (52%) and the AKA in 18 patients (18 %). The ASA was identified in 36/67 (54%)patients with 1.25 mm thickness and in15/32 (47%) patients with 2.5-3.0 mm thickness. This difference did not achieve significance (P=0.13). The detection rate of the ASA and the AKA was influenced by vertebral mass index and the CNR (P<0.05). The amount of subcutaneous fat affected the detection rate of the ASA (P<0.05) but not the AKA. In CT scans with ASA detection, the mean CT values in the aorta at the arch and at T11 were 360 and 358 HU, respectively; whereas in CT scans without ASA detection, the CT values in the aorta at the arch and at T11 were lower (297 and 317 HU, respectively; both P<0.05). Conclusion The ASA and AKA were less frequently detected in our cohorts than

  19. Low dose multi-detector CT of the chest (iLEAD Study): Visual ranking of different simulated mAs levels

    Energy Technology Data Exchange (ETDEWEB)

    Ley-Zaporozhan, Julia [Department of Diagnostic and Interventional Radiology, Ruprecht-Karls-University, Heidelberg (Germany); Department of Radiology (E010), German Cancer Research Center, Heidelberg (Germany)], E-mail: julia.leyzaporozhan@gmail.com; Ley, Sebastian [Department of Diagnostic and Interventional Radiology, Ruprecht-Karls-University, Heidelberg (Germany); Department of Radiology (E010), German Cancer Research Center, Heidelberg (Germany); Krummenauer, Frank [Clinical Epidemiology and Health Economy Unit, Carl Gustav Carus University Hospital, Dresden (Germany); Ohno, Yoshiharu [Department of Radiology, Kobe University Graduate School of Medicine, Kobe (Japan); Hatabu, Hiroto [Department of Radiology, Brigham and Women' s Hospital, Boston, MA (United States); Kauczor, Hans-Ulrich [Department of Diagnostic and Interventional Radiology, Ruprecht-Karls-University, Heidelberg (Germany)

    2010-02-15

    Purpose: Detailed evaluation of the lung parenchyma might be impaired by use of low dose CT as image noise increases and subsequently image quality decreases. The aim of our study was to determine the accuracy of visual perception of differences in image quality and noise at low dose chest CT. Materials and methods: Forty-four patients suffering from emphysema underwent CT (Aquilion-16, 120 kV, 150 mAs, 1 mm-collimation). Original raw data were used for simulation of 10 different mAs settings from 10 mAs to 100 mAs in 10 mAs increments. Three representative hard copy images (carina, 4 cm above, 5 cm below) were printed for evaluation of lung parenchyma (high-resolution kernel, lung window) and mediastinum (soft-kernel, soft tissue window). Ranking of expected low mAs level was performed for lung and soft tissue separately based on visual perception by three-blinded chest radiologist independently. Results were compared to the real simulated mAs. Results: The accuracy for correct ranking of the original 150 mAs scan was 89% for lung and 86% for soft tissue while it was 99% for the simulated 10 mAs for both windows. In comparison to the lowest mAs a significant error increase was found for the lung at 60-100 mAs (with error increase of 30-47%) for reader-I; 60-100 mAs for (33-64%) for reader-II and 70-100 mAs (38-57%) for reader-III. For the soft tissue: 60-150 mAs (with error increase of 28-63%) for reader-I; 50-100 mAs (35-56%) for reader-II and 50-90 mAs (35-40%) for reader-III. Conclusion: Simulated dose levels below 60 mAs (=42 mAs{sub eff}) were clearly differentiated from higher dose levels by all readers. Therefore, imaging doses could be lowered down to 60 mAs without a diagnostically relevant increase in noise impairing image quali0008.

  20. 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).

  1. 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.)

  2. 多排螺旋CT 诊断小网膜囊病变的价值%Diagnostic value of multi-detector CT for abnormalities in lesser omental bursa

    Institute of Scientific and Technical Information of China (English)

    成峰; 吴凯宏; 李孝虎

    2011-01-01

    目的 探讨小网膜囊正常解剖及病变的多排螺旋CT(MDCT)表现,评价小网膜囊病变的CT 诊断价值.方法 对24 例小网膜囊病变进行上腹部CT 平扫及三期增强扫描检查,均经手术病理证实.结果 小网膜囊病变中:原发肿瘤6 例(神经鞘瘤2 例,平滑肌瘤1 例,血管瘤1 例,脂肪肉瘤1 例,淋巴瘤1 例),CT 表现为小网膜囊内边界清晰肿块.邻近脏器的良、恶性肿瘤8 例(胰头癌4 例,肝左叶肝细胞癌2 例,胃间质瘤2 例),CT 表现为小网膜囊肿块与邻近相应肿瘤边界不清.转移性肿瘤2 例.结核1 例,CT 表现多个病灶融合,内见钙化.积液(腹水漏出液、炎性渗出液、脓液、血液、胆汁、淋巴液)6 例;假性囊肿1 例;CT 均表现为小网膜囊内液性密度灶.结论 多排螺旋CT对小网膜囊病变具有重要的诊断价值.%Objective To investigate the normal CT anatomy and diagnostic value of CT for abnormalities of lesser omental bursa. Methods Twenty-four patients with 6 primary neoplasms (2 neurinomas, 1 leiomyoma, 1 cavernous hemangioma, 1 liposarcoma, 1 lymphoma), 8 local spread from adjacent benign or malignant neoplasms (4 carcinomas of head of pancreas, 2 left hepatic tumors, 2 gastrointestinal stromal tumors of the stomach), 2 metastatic tumors, 1 tuberculosis, 6 fluid collections (transudate ascites, inflammatory infiltrate, pus, blood, bile, lymph), lpseudocyst were enrolled in the study. All of the lesions were confirmed by operation and pathology. The pre- and post-contrast abdominal CT scans were reviewed. Results The borders of the 6 primary neoplasms were well-defined on CT whereas the 8 benign or malignant neoplasms originating from adjacent structures were contiguous with the primary tumors. CT showed multiple aggregated lesions on 2 patients with metastases and 1 patient with tuberculosis. The 6 fluid collections and lpseudocyst displayed fluid density within lesser omental bursa on CT. Conclusion CT is valuable in

  3. 自发性腹腔干夹层的 MSCT 血管成像表现%Imaging manifestations of spontaneous celiac artery trunk dissection with multi-detector CT angiography

    Institute of Scientific and Technical Information of China (English)

    宁辉; 张龙江

    2015-01-01

    Objective:To summarize the multi-detector CT angiography (MDCTA)manifestations of spontaneous ce-liac artery trunk dissection.Methods:The clinical and MDCTA manifestations of 14 patients with spontaneous celiac artery trunk dissection were retrospectively analyzed.Results:Of the 14 patients,10 patients (71.4%,10/14)had spontaneous ce-liac artery trunk dissection,4 patients (28.6%,4/14)had both celiac artery trunk and superior mesenteric artery dissec-tion.Intimal plaque,orifice of dissection,true and false lumen were displayed in all involved 14 celiac artery trunk and 4 su-perior mesenteric artery dissections.Three dissected arteries were associated with thrombosis,2 dissected arteries with mu-ral calcification,2 dissected arteries with adjacent hematoma,and 1 with splenic infarct.Of the 14 celiac artery trunk dissec-tion,6 associated with aneurymal protrusion,and all 4 superior mesenteric artery dissection had aneurysmal protrusion asso-ciated.Two patients had celiac artery Digital Subtraction Angiography performed,the manifestations were similar to that of MSCT angiography.Intra-stent thrombosis was found in one patient underwent stent implantation.Conclusion:MDCT angi-ography can detect the pathology of celiac artery trunk dissection sensitively,which might used as the first choice modality for the diagnosis and follow up of this disease entity.%目的:总结自发性腹腔干夹层的 MSCT 血管成像表现。方法:回顾性分析14例自发性腹腔干夹层患者的临床及 MSCT 血管成像表现。结果:14例患者中自发性腹腔干夹层10例(71.4%,10/14),腹腔干和肠系膜上动脉夹层4例(28.6%,4/14)。14条腹腔干血管和4条肠系膜上动脉夹层均显示了内膜片、破口及真假腔,3条血管夹层合并血栓,2条夹层血管合并钙化,2例患者合并周围血肿,1例合并脾梗死。14条腹腔干夹层中6条血管夹层伴有动脉瘤样突起,4条肠系膜上动脉夹层

  4. Instrumentation for multi-detector arrays

    Indian Academy of Sciences (India)

    R K Bhowmik

    2001-07-01

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

  5. Double Chooz Improved Multi-Detector Measurements

    CERN Document Server

    CERN. Geneva

    2016-01-01

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

  6. The relationship between coronary artery calcification detected by non-gated multi-detector CT in patients with suspected ischemic heart disease and myocardial ischemia detected by thallium exercise stress testing

    International Nuclear Information System (INIS)

    The objective of this study was to examine whether we could predict myocardial ischemia when coronary artery calcification is detected by non-gated multidetector CT in patients with suspected ischemic heart disease. Eighty-three patients suspected of having ischemic heart disease (55 men, 28 women; age range 36-83 years; mean age 68 years) underwent multidetector CT and Tl-201 single photon emission computed tomography. Prediction of myocardial ischemia by coronary arterial calcification detected on CT was evaluated by comparing the coronary artery territories that showed calcification with the area of myocardial ischemia determined by SPECT. The sensitivity, specificity, positive predictive value, and negative predictive value of multidetector CT for predicting myocardial ischemia were calculated. Coronary angiography was also examined and compared with multidetector CT. Risk factors, including hypertension, smoking, hyperlipidemia, diabetes, and family history, were compared for evidence of coronary artery calcification detected by multidetector CT and myocardial ischemia detected by thallium nuclear scans. For analysis by patients, the sensitivity, specificity, positive predictive value, and negative predictive value of coronary artery calcification for myocardial ischemia detection were 65, 63, 56, and 71%, respectively. Similarly, for analysis by coronary arterial territories, those values were 56, 77, 41 and 86%, respectively. Coronary stenosis on CAG was also related to the ischemia determined by SPECT and calcification on multidetector CT. Ischemia was better influenced by risk factors than was coronary arterial calcification. For analysis by coronary arterial territories, the specificity and negative predictive value of coronary arterial calcification seen by multidetector CT are relatively high. (author)

  7. 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

  8. 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.

  9. Third-generation dual-source 70-kVp chest CT angiography with advanced iterative reconstruction in young children: image quality and radiation dose reduction

    Energy Technology Data Exchange (ETDEWEB)

    Rompel, Oliver; Janka, Rolf; Lell, Michael M.; Uder, Michael; Hammon, Matthias [University Hospital Erlangen, Department of Radiology, Erlangen (Germany); Gloeckler, Martin; Dittrich, Sven [University Hospital Erlangen, Department of Pediatric Cardiology, Erlangen (Germany); Cesnjevar, Robert [University Hospital Erlangen, Department of Pediatric Cardiac Surgery, Erlangen (Germany)

    2016-04-15

    Many technical updates have been made in multi-detector CT. To evaluate image quality and radiation dose of high-pitch second- and third-generation dual-source chest CT angiography and to assess the effects of different levels of advanced modeled iterative reconstruction (ADMIRE) in newborns and children. Chest CT angiography (70 kVp) was performed in 42 children (age 158 ± 267 days, range 1-1,194 days). We evaluated subjective and objective image quality, and radiation dose with filtered back projection (FBP) and different strength levels of ADMIRE. For comparison were 42 matched controls examined with a second-generation 128-slice dual-source CT-scanner (80 kVp). ADMIRE demonstrated improved objective and subjective image quality (P <.01). Mean signal/noise, contrast/noise and subjective image quality were 11.9, 10.0 and 1.9, respectively, for the 80 kVp mode and 11.2, 10.0 and 1.9 for the 70 kVp mode. With ADMIRE, the corresponding values for the 70 kVp mode were 13.7, 12.1 and 1.4 at strength level 2 and 17.6, 15.6 and 1.2 at strength level 4. Mean CTDI{sub vol}, DLP and effective dose were significantly lower with the 70-kVp mode (0.31 mGy, 5.33 mGy*cm, 0.36 mSv) compared to the 80-kVp mode (0.46 mGy, 9.17 mGy*cm, 0.62 mSv; P <.01). The third-generation dual-source CT at 70 kVp provided good objective and subjective image quality at lower radiation exposure. ADMIRE improved objective and subjective image quality. (orig.)

  10. Third-generation dual-source 70-kVp chest CT angiography with advanced iterative reconstruction in young children: image quality and radiation dose reduction

    International Nuclear Information System (INIS)

    Many technical updates have been made in multi-detector CT. To evaluate image quality and radiation dose of high-pitch second- and third-generation dual-source chest CT angiography and to assess the effects of different levels of advanced modeled iterative reconstruction (ADMIRE) in newborns and children. Chest CT angiography (70 kVp) was performed in 42 children (age 158 ± 267 days, range 1-1,194 days). We evaluated subjective and objective image quality, and radiation dose with filtered back projection (FBP) and different strength levels of ADMIRE. For comparison were 42 matched controls examined with a second-generation 128-slice dual-source CT-scanner (80 kVp). ADMIRE demonstrated improved objective and subjective image quality (P <.01). Mean signal/noise, contrast/noise and subjective image quality were 11.9, 10.0 and 1.9, respectively, for the 80 kVp mode and 11.2, 10.0 and 1.9 for the 70 kVp mode. With ADMIRE, the corresponding values for the 70 kVp mode were 13.7, 12.1 and 1.4 at strength level 2 and 17.6, 15.6 and 1.2 at strength level 4. Mean CTDIvol, DLP and effective dose were significantly lower with the 70-kVp mode (0.31 mGy, 5.33 mGy*cm, 0.36 mSv) compared to the 80-kVp mode (0.46 mGy, 9.17 mGy*cm, 0.62 mSv; P <.01). The third-generation dual-source CT at 70 kVp provided good objective and subjective image quality at lower radiation exposure. ADMIRE improved objective and subjective image quality. (orig.)

  11. 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

  12. 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

  13. 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)

  14. Experimental study about the effect of different scan parameters and post-processing methods of multi-detector CT on metallic artifacts%多排螺旋 CT 不同扫描参数及图像后处理方式对金属伪影的影响

    Institute of Scientific and Technical Information of China (English)

    储斌; 邹月芬; 王传兵

    2015-01-01

    目的:探讨多排螺旋 CT(MDCT)扫描参数及图像后处理方式对金属植入物伪影的影响,以期获得最佳方案减少金属伪影。方法制作钛合金钢板水模,将其置入 MDCT 下通过调节不同参数进行扫描(包括管电压、管电流、螺距、焦点),然后测定所得图像伪影面积大小并评价其相关性;对常规扫描参数下获得的15例椎体内固定术后患者图像进行后处理,分别使用常规方式和优化方式重建,包括多平面重建(MPR)、调节窗宽窗位及容积再现技术(VRT),然后评价图像质量。结果不同管电压、螺距、焦点下,伪影面积差异有统计学意义,随着管电压升高,伪影面积逐渐减小;随着螺距减小,伪影面积逐渐减小;使用小焦点扫描较大焦点伪影面积小;不同管电流下,伪影面积差异无统计学意义。图像后处理时骨窗重建选择软组织算法(Kernel B40f)、观察时选择窗位600 HU、窗宽2000 HU 及 VRT 三维重建可减少金属伪影。结论选择适当的 MDCT 扫描参数及图像后处理方式可以减少金属伪影,提高图像质量,有助于影像诊断。%Objective To explore the effect of multi-detector computed tomography (MDCT)scan parameters and imaging post-processing methods on metallic artifacts,so as to achieve the perfection in reduction of artifacts caused by metallic implants.Methods Water phantom with titanium alloy steel plate was scanned under MDCT with alternating scan parameters including tube voltage, tube current,pitch and focal spot.The areas of image artifacts were measured and correlated with the scan parameters.Another 1 5 postoperative patients with vertebral implantation scaned with the conventional scan parameters were also included in the study.Ima-ging post-processing including multi-planar reconstruction (MPR),window width and level adjustment,and volume rendering tech-nique (VRT)was performed by using optimized and

  15. Data acquisition for experiments with multi-detector arrays

    Indian Academy of Sciences (India)

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

    2001-07-01

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

  16. 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

  17. Middle and Long-term Follow-up of Multi-Detector Helical CT(HD 750)Angiography in the Evaluation of Artery of Lower Extremity Follow up after Artiifcial Vascular Graft%多排螺旋CT(HD750)血管造影在下肢动脉病变人工血管旁路移植术后中长期随访的应用价值

    Institute of Scientific and Technical Information of China (English)

    邓刚; 吴戈; 张藜莉; 王旭; 杨英; 刘戬; 金光暐; 尹晓明; 刘建新

    2016-01-01

    Objective To investigated the diagnostic value of 64 multi-detector helical CT angiography in artery of lower extremity middle and long-term follow up after artificial vascular graft.Methods 108 cases with artery of lower extremity postoperative artificial vascular graft after 3 years were performed with MDCTA. The data was transmitted to ADW4.3 workstation, and reconstructed by MIP, VR, CPR and generally analyzed with orginal axial images.Results In 108 cases with 147 grafts, MDCTA is can revealing the location and shape of artificial vascular graft, and evaluating collateral circulation and complication exactly.Conclusion 64 MDCTA is reliable and accurate in evaluating the artificial vascular graft, gradually become the first modality diagnose and evaluate artery of lower extremity follow up after artificial vascular graft at present.%目的 探讨多排螺旋CT(HD750)血管造影在下肢动脉人工血管旁路移植术后中长期随访的价值.方法 2004年7月至2011年2月对连续108例下肢动脉人工血管旁路移植术后3年以上患者进行了多排螺旋CT(HD750)血管造影检查,采用容积显示(VR);最大密度投影(MIP);曲面重建(CPR);仿真内窥镜(VE)及高级血管分析(AVA)等多种后处理技术并结合原始横轴位图像进行综合分析.结果 多种后处理图像相结合共显示移植血管147条,可以准确评估人工移植血管的位置及形态、吻合口处病变情况、移植血管腔内狭窄程度、侧支循环开放和并发症等.其中53例患者(64条移植血管)与同期DSA检查进行了比较研究.全部病例MDCTA检查结果均符合临床诊断要求.结论 多排螺旋CT(HD750)血管造影术对人工移植血管的评价是安全、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中长期随访的首选影像诊断方法.

  18. Myocardial perfusion with multi-detector computed tomography: quantitative evaluation

    International Nuclear Information System (INIS)

    The objective of this work is to evaluate the skill of multidetector computer tomography, to quantify the different patterns of intensification during the evaluation of the myocardial perfusion. 45 patients were studied with suspicion of cardiovascular disease. Multi-detector computed tomography was utilized on patients at rest and in effort with pharmacological stress, after the administration of dipyridamole. Also they were evaluated using nuclear medicine

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2005-08-01

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

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

    Institute of Scientific and Technical Information of China (English)

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

    2013-01-01

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

  1. 64排128层螺旋CT图像重建技术对胆脂瘤型中耳炎的术前评估价值%The Value of Preoperative Assessment about Otitis Media with Cholesteatoma by Image Reconstruction of 64-Multidetector 128-Slice Computer Tomography

    Institute of Scientific and Technical Information of China (English)

    相丽; 郑穗生

    2011-01-01

    Obiective To explore the advantages and disadvantages of post-processing techniques of MSCT to the manifestation of bone destruction in ears with otitis media with cholesteatoma. Materials and Methods fmage reconstruction of 64-multidetector 128-slice CT were performed to middle and internal ears of 42 ears with otitis media with cholesteatoma in different ways. The images were compared to intraoperative findings, and the concordance of the two underwent Kappa test. SPSS was used to deal with the results. High concordance was defined as Kappa ≥0.75. Acceptable concordance was defined as 0. 41/Ukappa"00.75. Low concordance was defined as Kappa"U0.4. Results Kappa values of head of malleus, long crus of incus, short crus of incus, body of incus body, bone destruction of meningeal board, aditus ad antrum expanding and structure defects of horizontal segment of facial nerve canal were greater than 0.75L?Kappa values of handle of malleus, incudomelleolar joints, horizontal and labyrinthin segment of facial nerve canal, semicircular canal, scutum, bone wall of sigmoid sinus and bone destruction of labyrinth were between 0.4 and 0.75, but Kappa values of incudostapedial joint, anterior crus of stapes, posterior crus of stapes and bone destruction of footplate of stapes were less than 0.4. Conclusions Images of bone destruction in middle and internal ears with otitis media with cholesteatoma have important reference value for the operation.%目的 探讨MSCT后处理技术对胆脂瘤型中耳炎骨质破坏情况显示的优劣势.材料与方法 采用64排128层螺旋CT对42耳胆脂瘤型中耳炎中耳及内耳结构进行多种方式重建,结果与术中所见对照,Kappa检验二者的一致性,采用SPSS11.0软件包处理,规定 Kappa值大于或等于0.75为两者有很高的一致程度,其值在0.4-0.75说明一致程度尚可.小于0.4则说明一致程度不够理想.结果 锤骨头、砧骨长脚、砧骨短脚、砧骨体、脑膜板骨壁骨质破坏

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2008-03-15

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

  3. Toroid cavity/coil NMR multi-detector

    Science.gov (United States)

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

    2007-09-18

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

  4. Azygos system on multi detector computed tomography: Pictorial essay

    International Nuclear Information System (INIS)

    Since three dimensional and reformatted CT images can show changes in the location and size of the azygos system, changes in the surrounding vessels, and combined anomalies of vessels or organs, CT is useful for diagnosing congenital and acquired abnormalities of the azygos system. In this article, we review CT findings in regards to various disorders involving the azygos system

  5. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2011-09-15

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

  7. 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.

  8. 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.

  9. Search for continuous gravitational waves: metric of the multi-detector F-statistic

    OpenAIRE

    Prix, R.

    2007-01-01

    We derive the parameter-space metric of the multi-detector F-statistic, which is the optimal detection statistic for continuous gravitational waves in stationary Gaussian noise. We find that there is a family of F-statistic metrics, parametrized by the (unknown) amplitude parameters. We explicitly derive the maximal mismatch-range of this metric family, and we introduce a corresponding "average" F-metric. We show that the multi-detector metric consists of noise-weighted averages of single-det...

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

    Directory of Open Access Journals (Sweden)

    Zhi-hui Dong

    2011-01-01

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

  11. 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

  12. Multi-detector setup for nuclear astrophysical reaction studies on the low energy ion beam

    International Nuclear Information System (INIS)

    The multi-detector setup assembled on the basis of the ion beam from 'SOKOL' electrostatic accelerator is described. The setup allows one to measure three various spectra in a single experiment: prompt gamma-quanta from nuclear reactions, positrons from the decays of radioactive nuclei formed in the reactions and coincidence spectrum of annihilation gamma-quanta. (authors)

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

    Institute of Scientific and Technical Information of China (English)

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

    2010-01-01

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

  14. [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

  15. Multi-detector CT and 3D imaging in a multi-vendor PACS environment

    NARCIS (Netherlands)

    van Ooijen, PMA; Witkamp, R; Oudkerk, M; Lemke, HU; Inamura, K; Doi, K; Vannier, MW; Farman, AG; Reiber, JHC

    2003-01-01

    Introduction of new hard- and software techniques like Multi-Dectector Computed Tomography (MDCT) and 3D imaging has put new demands on the Picture Archiving and Communications System (PACS) environment within the radiology department. The daily use of these new techniques requires a good integratio

  16. Assessment of left ventricular volumes using multi-detector row computed tomography (MDCT). Phantom and human studies

    International Nuclear Information System (INIS)

    Multi-detector row CT (MDCT) is a new noninvasive modality for coronary artery imaging. Using the same MDCT data obtained for coronary artery assessment, left ventricular (LV) volumes such as end-diastolic (ED) and end-systolic (ES) volumes (EDV and ESV, respectively) and ejection fraction (EF) can potentially be assessed when ED and ES datasets are extracted. The purpose of this study was to evaluate the feasibility of MDCT in the assessment of LV volumes. Using a pulsating heart phantom (EDV=143 ml, ESV=107 ml, stroke volume=36 ml, EF=25%) and MDCT, EDV and ESV were measured and EF was calculated. Clinical materials consisted of 11 consecutive human subjects who underwent MDCT. MDCT data were acquired during a single breathhold, using an intravenous injection of contrast medium. Left ventriculography (LVG) was performed in all patients as a gold standard. LV-EF was calculated by measuring ESV and EDV in all patients. In the phantom study, LV volumes were: EDV=137 ml, ESV=101 ml, stroke volume=36 ml, and EF=26%. Close correlations were observed between MDCT values and LVG values (EDV: r=0.95, ESV: r=0.98, EF: r=0.93, p<0.001). MDCT was useful for the assessment of LV volumes and EF in various patients with cardiovascular diseases (CVD). (author)

  17. Bent Si monochromator—multi-detector neutron diffractometer installed at B4 super-mirror thermal guide tube in KUR

    Science.gov (United States)

    Achiwa, N.; Kawano, S.; Hino, M.; Mikula, P.; Ono, M.; Fukunaga, T.

    2004-08-01

    A new multi-detector neutron diffractometer has been installed at B4 thermal supermirror neutron guide in KUR, using a new bent Si monochromator developed by Mikula et al. and Ono et al.. Here we report resolutions of powder diffraction patterns by the multi-detector neutron diffractometer, which mainly depend on a radius of sample. Bragg diffraction optics by bent perfect crystal shows improvement of resolution without loss of luminosity and the multi- detector on the same 2 θ arm can gain the intensity without loosing resolution.

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

    Institute of Scientific and Technical Information of China (English)

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

    2009-01-01

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

  19. Evaluation of spinal trauma by multi detector computed tomography and magnetic resonance imaging

    OpenAIRE

    Gihan Hassan Gamal

    2014-01-01

    Aim of work: The aim of this work is to assess the role of multi-detector computed tomography (MDCT) and magnetic resonance imaging (MRI) in evaluation of spinal trauma. Patients and methods: Between January 2013 and April 2014, 98 patients (78 males and 20 females) with spinal injuries were investigated by MDCT and MRI. Assessment of the radiological findings of spinal injury was performed and the following were investigated: vertebral compression fractures, bursts and dislocations, poste...

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

    CERN Document Server

    Haris, K

    2015-01-01

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

  1. 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)

  2. Cardiac pathologies incidentally detected with non-gated chest CT; Inzidentelle Pathologien des Herzens im Thorax-CT

    Energy Technology Data Exchange (ETDEWEB)

    Scherer, Axel; Kroepil, P.; Lanzman, R.S.; Moedder, U. [Inst. fuer Radiologie, Universitaetsklinikum Duesseldorf, Heinrich-Heine-Univ. (Germany); Choy, G.; Abbara, S. [Cardiovascular Imaging Section, Massachusetts General Hospital, Harvard Medical School (United States)

    2009-12-15

    Cardiac imaging using electrocardiogram-gated multi-detector computed tomography (MDCT) permits noninvasive diagnosis of congenital and acquired cardiac pathologies and has thus become increasingly important in the last years. Several studies investigated the incidence and relevance of incidental extracardiac structures within the lungs, mediastinum, chest wall, and abdomen with gated coronary CT. This resulted in the general acceptance of the review of extracardiac structures as a routine component of coronary CT interpretation. On the other hand radiologists tend to neglect pericardial and cardiac pathologies in non-gated chest CT, which is primarily performed for the evaluation of the respiratory system or for tumor staging. Since the introduction of multi-detector spiral CT technology, the incidental detection of cardiac and pericardial findings has become possible using non-gated chest CT. This article reviews the imaging appearances and differential diagnostic considerations of incidental cardiac entities that may be encountered in non-gated chest CT. (orig.)

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-03-15

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

  4. Comparison of 16 slice multi-detector computed tomography and breath hold 3D magnetic resonance angiography in the detection of coronary stenosis

    Institute of Scientific and Technical Information of China (English)

    Xin LIU; Zulong CAI; Youquan CAI; Shaohong ZHAO; Ningyu AN; Yuangui GAO

    2006-01-01

    Objective To compare 16-slice multi-detector spiral computed tomography (MDCT) and breathhold 3D magnetic resonance (MR) coronary angiography in the visualization of coronary arteries and the accuracy of detecting significant (> 50%) coronary stenoses in patients with suspected coronary artery disease. Methods Forty patients were examined by 16-slice CT (GE, Lightspeedl6)and MR (GE,Twinspeed) within 3 days; 31 of them underwent conventional coronary angiography (CAG) within 2 weeks after CT and MR scan. CT was performed with 16× 1.25 mm detector collimation, 0.5 s rotation time and images were reconstructed at 60%-75% of the cardiac cycle. MR was performed with breath hold 3D FIESTA (TR4.0 ms, TE1.7 ms, flip angle 65, slice thickness 3 mm, FOV 280 mm, matrix 256× 192). Mean heart rate was 63 ± 5.8 bpm and β-blocker was used in 24 patients. MR and CT image quality was evaluated in 9 coronary segments (RCA1, RCA2, RCA3, LM, LAD1, LAD2, LAD3, LCX1, LCX2) using a four-point grading scale.Sensitivity, specificity, positive predictive value, negative predictive value and accuracy were calculated for detection of significant stenosis using CAG as the gold standard. Results 16-slice CT showed higher image quality in most coronary segments except RCA2.Forty-three segments were diagnosed as significant stenosis by CAG, 36 and 27 of these were correctly detected by CT and MR respectively. Sensitivity, specificity, positive predictive value, and negative predictive value of 16-slice CT and MR for detecting significant stenosis were 83 %, 84 %, 49 %, 97 % and 63 %, 90 %, 55 %, 93 %, respectively. Conclusion Sixteen-slice CT showed higher image quality in most coronary segments excepted for middle RCA. 16-slice CT had higher sensitivity than MR for detection of coronary significant stenosis, whereas MR had higher specificity than CT. Both CT and MR showed high negative predictive value,which is useful for excluding coronary stenosis in symptomatic patients.

  5. Control electronics for a multi-laser/multi-detector scanning system

    Science.gov (United States)

    Kennedy, W.

    1980-01-01

    The Mars Rover Laser Scanning system uses a precision laser pointing mechanism, a photodetector array, and the concept of triangulation to perform three dimensional scene analysis. The system is used for real time terrain sensing and vision. The Multi-Laser/Multi-Detector laser scanning system is controlled by a digital device called the ML/MD controller. A next generation laser scanning system, based on the Level 2 controller, is microprocessor based. The new controller capabilities far exceed those of the ML/MD device. The first draft circuit details and general software structure are presented.

  6. Double Chooz: optimizing the sensitivity to {theta}{sub 13} with a multi-detector setup

    Energy Technology Data Exchange (ETDEWEB)

    Novella, P. [CIEMAT, Av. Complutense 22, 28040 Madrid (Spain)

    2012-08-15

    The best upper limit to the neutrino mixing angle {theta}{sub 13} is set by the CHOOZ experiment. The eventual measurement of {theta}{sub 13} in reactor neutrino experiments relies on a reduction of the CHOOZ systematics of about 1 order of magnitude, along with a major increase of the luminosity. Provided that enough statistics are achieved, fighting the systematics becomes the key towards {theta}{sub 13}. The Double Chooz experiment engages this fight with a multi-detector set up.

  7. 阻塞性睡眠呼吸暂停低通气综合征上气道舌骨位置改变的研究%The clinical significance of the changed positions of hyoid bone in the upper airway of OSAHS patients by 128-slice computed tomography

    Institute of Scientific and Technical Information of China (English)

    徐蓉; 吴绯红; 苏筱芮; 张博薇; 粟丽; 李海军; 彭德昌

    2015-01-01

    目的:探讨阻塞性睡眠呼吸暂停低通气综合征(OSAHS)患者舌骨位置的变化对该病发病机制的影响及指导治疗的价值。方法:采用128层螺旋CT分别对52例重度OSAHS 成年男性行清醒和Muller 试验状态及32例正常人行清醒状态上气道扫描,分别测量舌骨位置,进行统计学分析,并与 AHI、MSaO2进行线性相关分析。结果:与正常组相比,清醒状态OSAHS组颏结节、硬腭平面至舌骨距离较长,差异具有统计学意义(P <0.001)。与清醒期相比,Muller状态下OSAHS组颏结节至舌骨距离增加,差异具有统计学意义(P <0.001)。硬腭平面至舌骨距离与AHI呈正相关;硬腭平面、颏结节至舌骨距离与MSaO2呈负相关。结论:舌骨位置的改变对OSAHS的发病及病情严重程度具有重要影响,对指导临床治疗有重要意义。%Objective To discuss the clinical diagnostic and guiding treatment value of changed positions of hyoid bonein the upper airway of patients with obstructive sleep apnea hypopnea syndrome. Methods 128-slice computed tomography was performed for 52 patients with severe OSAHS and 32normal healthy people to measure thehyoid bone in the upper airway in sober state and Muller maneuver. The correlationsbetweenthese indexes were analyzed under linear relation. Results (1)In comparison of the Muller maneuver with sober state , chinnodules and palatal plane to the hyoid in the OSAHS group were statistically higher than the healthy controlgroup (P < 0.001). (2)The distance of hyoid to chinnodules in the OSAHS group was significantlylonger and greater than that of the healthy control group (P < 0.001).(3)The distance of palatal plane to the hyoid was positively correlated with AHI , while thedistances of palatal plane andchinnodules to the hyoidwere both negatively correlated with MSaO2. Conclusion The changes ofhyoid positionare indicative for the clinical diagnosis and is helpful for

  8. Novel wearable and wireless ring-type pulse oximeter with multi-detectors.

    Science.gov (United States)

    Huang, Cheng-Yang; Chan, Ming-Che; Chen, Chien-Yue; Lin, Bor-Shyh

    2014-01-01

    The pulse oximeter is a popular instrument to monitor the arterial oxygen saturation (SPO2). Although a fingertip-type pulse oximeter is the mainstream one on the market at present, it is still inconvenient for long-term monitoring, in particular, with respect to motion. Therefore, the development of a wearable pulse oximeter, such as a finger base-type pulse oximeter, can effectively solve the above issue. However, the tissue structure of the finger base is complex, and there is lack of detailed information on the effect of the light source and detector placement on measuring SPO2. In this study, the practicability of a ring-type pulse oximeter with a multi-detector was investigated by optical human tissue simulation. The optimal design of a ring-type pulse oximeter that can provide the best efficiency of measuring SPO2 was discussed. The efficiency of ring-type pulse oximeters with a single detector and a multi-detector was also discussed. Finally, a wearable and wireless ring-type pulse oximeter was also implemented to validate the simulation results and was compared with the commercial fingertip-type pulse oximeter.

  9. Novel Wearable and Wireless Ring-Type Pulse Oximeter with Multi-Detectors

    Directory of Open Access Journals (Sweden)

    Cheng-Yang Huang

    2014-09-01

    Full Text Available The pulse oximeter is a popular instrument to monitor the arterial oxygen saturation (SPO2. Although a fingertip-type pulse oximeter is the mainstream one on the market at present, it is still inconvenient for long-term monitoring, in particular, with respect to motion. Therefore, the development of a wearable pulse oximeter, such as a finger base-type pulse oximeter, can effectively solve the above issue. However, the tissue structure of the finger base is complex, and there is lack of detailed information on the effect of the light source and detector placement on measuring SPO2. In this study, the practicability of a ring-type pulse oximeter with a multi-detector was investigated by optical human tissue simulation. The optimal design of a ring-type pulse oximeter that can provide the best efficiency of measuring SPO2 was discussed. The efficiency of ring-type pulse oximeters with a single detector and a multi-detector was also discussed. Finally, a wearable and wireless ring-type pulse oximeter was also implemented to validate the simulation results and was compared with the commercial fingertip-type pulse oximeter.

  10. Excess radiation and organ dose in chest and abdominal CT due to CT acquisition beyond expected anatomical boundaries

    Energy Technology Data Exchange (ETDEWEB)

    Zanca, Federica; Demeter, Martine; Oyen, Raymond; Bosmans, Hilde [University Hospitals Leuven, Department of Radiology, Leuven (Belgium)

    2012-04-15

    To assess the extent of extra imaging beyond the prescribed anatomical margins for chest and abdominal CT and to determine associated extra patient and organ dose estimates. For 167 consecutive patients undergoing routine chest and/or abdominal examination with 128-slice CT, extra imaging length was evaluated on coronal images. Effective and organ doses (thyroid, liver, breasts, testes) were calculated. Paired t-test was applied to evaluate statistically significant differences between prescribed and actual imaging length, and associated doses. 133 (80%) examinations had extra coverage (mean 4.6 cm, range 1-19.5 cm). Significantly higher (P < 0.05) effective doses for chest CT (mean 4.8 mSv vs 4.2 mSv for actual vs prescribed volume of interest), abdominal CT (8.4 mSv vs 7.9 mSv) or thorax-abdominal CT (12.8 mSv vs 11.9 mSv) were found. A significantly higher (P < 0.001) organ dose was estimated for thyroid (extra dose 99% corresponding to 5.1 mSv), liver (56%, 2.2 mSv), testes (115%, 7.6 mSv), and breasts (163%, 1.5 mSv). Imaging beyond anatomical limits during routine chest and abdominal CT results in higher organ and effective doses. Continuous training of the technologists remains important. Physicians and technologists must be kept aware of the additional dose associated with extra imaging. (orig.)

  11. A cardiac phantom study on quantitative correction of coronary calcium score on multi-detector, dual source, and electron beam tomography for velocity, calcification density, and acquisition time

    Science.gov (United States)

    Greuter, Marcel J. W.; Groen, Jaap M.; Nicolai, Lieuwe J.; Dijkstra, Hildebrand; Oudkerk, Matthijs

    2009-02-01

    Objective: To quantify the influence of velocity, calcification density and acquisition time on coronary calcium determination using multi-detector CT, dual-source CT and EBT. Materials and Methods: Artificial arteries with four calcifications of increasing density were attached to a robotic arm to which a linear movement was applied between 0 and 120 mm/s (step 10 mm/s). The phantom was scanned five times on 64-slice MDCT, DSCT and EBT using a standard acquisition protocol and the average Agatston score was determined. Results: Increasing motion artifacts were observed at increasing velocities on all scanners, with increasing severity from EBT to DSCT to 64-slice MDCT. The Agatston score showed a linear dependency on velocity from which a correction factor was derived. This correction factor showed a linear dependency on calcification density (0.92density of individual calcifications. The dependency of the Agatston score on velocity shows a linear behaviour on calcification density. A quantitative method could be derived which corrects the measured calcium score for the influence of velocity, calcification density and acquisition time.

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

    International Nuclear Information System (INIS)

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

  13. Performance comparison of multi-detector detection statistics in targeted compact binary coalescence GW search

    CERN Document Server

    Haris, K

    2016-01-01

    Global network of advanced Interferometric gravitational wave (GW) detectors are expected to be on-line soon. Coherent observation of GW from a distant compact binary coalescence (CBC) with a network of interferometers located in different continents give crucial information about the source such as source location and polarization information. In this paper we compare different multi-detector network detection statistics for CBC search. In maximum likelihood ratio (MLR) based detection approaches, the likelihood ratio is optimized to obtain the best model parameters and the best likelihood ratio value is used as statistic to make decision on the presence of signal. However, an alternative Bayesian approach involves marginalization of the likelihood ratio over the parameters to obtain the average likelihood ratio. We obtain an analytical expression for the Bayesian statistic using the two effective synthetic data streams for targeted search of non-spinning compact binary systems with an uninformative prior on...

  14. Quantitative assessment of lung volumes using multi-detector row computed tomography (MDCT) in patients with chronic obstructive pulmonary disease (COPD)

    International Nuclear Information System (INIS)

    To evaluate the clinical value of the multi-detector row computed tomography (MDCT) in the quantitative assessment of lung volumes and to assess the relationship between the MDCT results and disease severity as determined by a pulmonary function test (PFT) in Chronic Obstructive Pulmonary Disease (COPD) patients. We performed a PFT and MDCT on 39 COPD patients. Using the GOLD classifications, we divided the patients into three groups according to disease severity; stage I (mild, n = 10), stage II (moderate, n = 15), and stage III (severe, n = 14). Using the pulmo-CT software program, we measured the proportion of lung volumes with attenuation values below -910 and -950 HU. The mean FEV1 (% of predicted) and FEV1/FVC was 82.2 ± 2% and 66.2 ± 3% in stage I, 53.5 ± 11% and 52 ± 6% in stage II, and 32.3 ± 7% and 44.2% ± 13% in stage III, respectively. Differences in lung volume percentage at each of the thresholds (-910 and -950 HU) among the 3 stages were statistically significant (ρ < 0.01, ρ < 0.01) and correlated well with the FEV1 and FEV1/FVC (r = -0.803, r -0.766, r = -0.817, and r = -0.795, respectively). The volumetric measurement obtained by MDCT provides an accurate means of quantifying pulmonary emphysema

  15. Quantitative assessment of lung volumes using multi-detector row computed tomography (MDCT) in patients with chronic obstructive pulmonary disease (COPD)

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Sang Min; Hur, Jin; Kim, Tae Hoon; Kim, Sang Jin; Kim, Hyung Jung [Yonsei University College of Medicine, Seoul (Korea, Republic of)

    2008-08-15

    To evaluate the clinical value of the multi-detector row computed tomography (MDCT) in the quantitative assessment of lung volumes and to assess the relationship between the MDCT results and disease severity as determined by a pulmonary function test (PFT) in Chronic Obstructive Pulmonary Disease (COPD) patients. We performed a PFT and MDCT on 39 COPD patients. Using the GOLD classifications, we divided the patients into three groups according to disease severity; stage I (mild, n = 10), stage II (moderate, n = 15), and stage III (severe, n = 14). Using the pulmo-CT software program, we measured the proportion of lung volumes with attenuation values below -910 and -950 HU. The mean FEV1 (% of predicted) and FEV1/FVC was 82.2 {+-} 2% and 66.2 {+-} 3% in stage I, 53.5 {+-} 11% and 52 {+-} 6% in stage II, and 32.3 {+-} 7% and 44.2% {+-} 13% in stage III, respectively. Differences in lung volume percentage at each of the thresholds (-910 and -950 HU) among the 3 stages were statistically significant ({rho} < 0.01, {rho} < 0.01) and correlated well with the FEV1 and FEV1/FVC (r = -0.803, r -0.766, r = -0.817, and r = -0.795, respectively). The volumetric measurement obtained by MDCT provides an accurate means of quantifying pulmonary emphysema.

  16. Measurement of radon, radon daughters and thoron concentrations by multi-detector devices. No. E/12

    International Nuclear Information System (INIS)

    There is a growing interest in collection of data concerning human exposures to naturally occurring alpha-emitting radionuclides (e.g. in mines, dwellings, building materials, industrial wastes, coal fuel cycle, water supply, soil, plants, etc.). Most of such studies are incomplete for the following reasons: in radon measurements the contribution of thoron is generally neglected, the determination of equilibrium factor is complicated or not possible at all, short- and long-term concentration fluctuations cause difficulties in obtaining representative mean values, the plate-out effect is generally not taken into account. A variety of simple methods were studied that could be used to overcome some of these difficulties by using cups equipped with two or more alpha-sensitive nuclear track detectors. A theoretical foundation of the quantitative measurements with such devices is presented. Experimental data are reported on radon, radon daughters and thoron concentrations measured by multi-detector devices in cave soil gas and in air of Hungarian dwellings. (author)

  17. Use of multi-detector CT angiography in identification and classification of aorto-iliac diseases; clinical and surgical application

    Directory of Open Access Journals (Sweden)

    Reda Abdelsamie Alarabawy

    2016-03-01

    Conclusions: MDCT angiography is excellent noninvasive scanning technique for patients suspected of having aorto-iliac occlusive disease, with higher spatial resolution and faster acquisition times, allowing assessment of the aorta and its branches with greater accuracy than other modalities.

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

    Directory of Open Access Journals (Sweden)

    Rakesh

    2014-01-01

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

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

    International Nuclear Information System (INIS)

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-05-15

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

  1. Multi-detector and systematic imaging system designed and developed within the New AGLAE project

    International Nuclear Information System (INIS)

    Full text: The New AGLAE project aims to establish a world-class facility for non invasive analysis of Cultural Heritage materials. One of the objectives of the New AGLAE project is to increase the x-ray measurement detection, enabling to reduce the beam intensity thus the interaction with sensitive artworks by a ten. Multidisciplinary, the New AGLAE project will provide an exceptional and multipurpose beam line with a performance in spatial resolution, beam stability and a capability of multi-particle detection much higher than for the previous facility. The New AGLAE will give fundamental elements for the understanding of the structure of materials, their composition, properties, and change over time. One of the objectives of this project is to design and set up a new data acquisition system. To reach that purpose, the surface and the number of PIXE detectors have been increased. Indeed, a 10 mm2 and a 30 mm3 Si(Li) detectors respectively dedicated to low and high energy measurements, were replaced by a cluster of five 50 mm2 S.D.D. detectors. If this multi detector enables to decrease the intensity of the incident beam by one order of magnitude, involving less irradiation during the analysis, it can also provide large and/or fast maps. So as to digital the preamp pulses obtained from the detectors, a custom Digital X-ray Processor provides both digital data and control signals compatible to a multiparameter multichannel system. This multiparameter system saves each event from x-ray, gamma and particle detectors and simultaneously the X, Y positions of the beam on the sample as a list file. Furthermore, to draw several-cm-sized maps with a 20/40μm resolution, the scanning of the area originally combines a fast vertical magnetic deflection of the beam and a mechanical movement of the target. To process the data, several homemade software have been developed or updated so as to rebuild any matrix of spectra, to re-bin maps, to process a series of single spectra by

  2. Multi-detector computer tomography venography (MDCTV as a diagnostic tool in the management of patients with atypical, complicated and/or recurrent varicose veins

    Directory of Open Access Journals (Sweden)

    Andrew Lawson

    2012-12-01

    Full Text Available Aim. To evaluate the role of multi-detector computer tomography venography (MDCTV, compared with conventional venography, as a diagnostic tool in the management of patients with atypical, complicated and/or recurrent varicose veins. Materials and methods. Retrospective review of 21 patients who had undergone both MDCTV and conventional transfemoral or transpopliteal venography between January 2008 and April 2011 for the management of recurrent varicose veins and/or chronic venous ulcers. MDCTV was performed using a 16-slice CT scanner. Spiral acquisition was commenced 180 seconds after intravenous injection of 150 ml of 350 mmol/l iodinated contrast medium. A reconstruction interval of 1.5 mm was used. Conventional venography was performed by the resident vascular surgeon and was followed by stenting or coiling where appropriate. Results. MDCTV and venography were compared in 21 patients (6 male, 15 female; average age 55 years, range 33 - 78 years; 8 also underwent endovascular iliac vein stenting. The area under the receiver operator curve (ROC for percentage iliac vein stenosis determined on MDCTV versus venography was 0.75. Four (19% false-positive iliac vein stenoses were reported on MDCTV. Ten patients underwent gonadal vein coil embolisation. Gonadal vein size >5.2 mm (range 1 - 11 mm on MDCTV predicted significant venographic reflux requiring coil embolisation. Three (30% patients who underwent embolisation did not have gonadal vein enlargement on MDCTV. Conclusion. MDCTV plays an important adjunctive role in the diagnostic workup of patients with complex venous disease. The findings at MDCTV correlate well with conventional venography.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2008-03-15

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

  4. An F-statistic based multi-detector veto for detector artifacts in continuous-wave gravitational wave data

    OpenAIRE

    Keitel, D.; Prix, R.; Papa, M.; Siddiqi, M.

    2012-01-01

    Continuous gravitational waves (CW) are expected from spinning neutron stars with non-axisymmetric deformations. A network of interferometric detectors (LIGO, Virgo and GEO600) is looking for these signals. They are predicted to be very weak and retrievable only by integration over long observation times. One of the standard methods of CW data analysis is the multi-detector F-statistic. In a typical search, the F-statistic is computed over a range in frequency, spin-down and sky position, and...

  5. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2006-03-15

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

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

    International Nuclear Information System (INIS)

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

  8. Multi-detector computed tomography (MDCT findings of chemotherapy induced hepatic chan

    Directory of Open Access Journals (Sweden)

    Sieza Samir Abd-Allah

    2016-09-01

    Results: Forty patients (32 females and 8 males had hepatic changes due to effect of chemotherapy. The most common CT finding was fatty liver. Hepatic fatty changes were detected in 36/40 patients. These fatty changes were diffuse, focal fatty and diffuse with fatty spare area. Four patients had capsular retraction: 1 patient with HD and 3 patients with metastatic cancer breast. Veno-occlusive disease and biliary sclerosis were not detected.

  9. Serial changes of coronary atherosclerotic plaque: Assessment with 64-slice multi-detector computed tomography

    International Nuclear Information System (INIS)

    Evaluate the progression of coronary atherosclerotic plaque during follow-up, and its association with cardiovascular risk factors. Fifty-six atherosclerotic patients with plaque were enrolled in this retrospective study. Patient's plaque was detected on repeat 64-slice multidetector CT scans with a mean interval of 25 ± 10 months changes in calcified and non-calcified plaque volumes and cardiovascular risk factors were assessed over time. Absolute and relative changes in plaque volume were compared, and the association between rapid progression and cardiovascular risk factors was determined. Diameter of the stenosis, length, calcified and non-calcified lesion plaque volumes increased significantly on follow-up CT. Absolute and relative annual changes in plaque volumes were significantly greater in non-calcified plaque (median, 22.7 mm3, 90.4%) than in calcified plaque (median, 0.7 mm3, 0%). Obesity, smoking, hypertension, hypercholesterolemia, and low high-density lipoprotein were significant predictors of progression of non-calcified plaque. Progression of calcified plaque was not associated with any cardiovascular risk factors. Coronary plaque volume increased significantly on follow-up CT. The rate of progression is related to non-calcified plaque than to calcified plaque. Cardiovascular risk factors are independently associated with the rapid progression of non-calcified plaque volume, but not associated with the progression of calcified plaque.

  10. Serial changes of coronary atherosclerotic plaque: Assessment with 64-slice multi-detector computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Eun Young; Kang, Doo Kyoung; Sun, Joo Sung; Choi, So Yeon [Ajou University School of Medicine, Suwon (Korea, Republic of)

    2013-12-15

    Evaluate the progression of coronary atherosclerotic plaque during follow-up, and its association with cardiovascular risk factors. Fifty-six atherosclerotic patients with plaque were enrolled in this retrospective study. Patient's plaque was detected on repeat 64-slice multidetector CT scans with a mean interval of 25 ± 10 months changes in calcified and non-calcified plaque volumes and cardiovascular risk factors were assessed over time. Absolute and relative changes in plaque volume were compared, and the association between rapid progression and cardiovascular risk factors was determined. Diameter of the stenosis, length, calcified and non-calcified lesion plaque volumes increased significantly on follow-up CT. Absolute and relative annual changes in plaque volumes were significantly greater in non-calcified plaque (median, 22.7 mm{sup 3}, 90.4%) than in calcified plaque (median, 0.7 mm{sup 3}, 0%). Obesity, smoking, hypertension, hypercholesterolemia, and low high-density lipoprotein were significant predictors of progression of non-calcified plaque. Progression of calcified plaque was not associated with any cardiovascular risk factors. Coronary plaque volume increased significantly on follow-up CT. The rate of progression is related to non-calcified plaque than to calcified plaque. Cardiovascular risk factors are independently associated with the rapid progression of non-calcified plaque volume, but not associated with the progression of calcified plaque.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2004-08-01

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

  12. 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.)

  13. 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

  14. Multilayer CT. A guideline; Mehrschicht-CT. Ein Leitfaden

    Energy Technology Data Exchange (ETDEWEB)

    Bruening, R. [Asklepios Klinik Barmbek, Hamburg (Germany). Roentgeninstitut; Kuettner, A. [Universitaetsklinikum Erlangen (Germany). Inst. fuer Diagnostische Radiologie; Flohr, T. [Siemens Medizin Systeme, Forchheim (Germany). MED CTE PA

    2008-07-01

    This book provides structured and actual information concerning all routine applications of multi-detector computer tomography, including the latest device generation dual slice or dual layer devices, respectively. The book contains extensive chapters on the technical background and discusses systematically all important organ systems: heart, head and neck, thorax and abdomen including parenchymal organs and the gastrointestinal tract. Each protocol is presented in tabular form, thus allowing a fast overview on the favoured applications and the required settings of the CT device. All contributions are provided by approved CT experts, who do not only introduce their vast clinical experience into every topic, but have also worked out guidelines for indications, operational sequences, post-processing and reconstruction algorithms. [German] Dieses Buch bietet strukturierte und aktuellste Informationen zu allen Routineanwendungen der Mehrschicht- (Multidetektor-) Computertomographie, auch der neuesten Geraetegeneration (Dual-Slice bzw. Dual-Layer). Es enthaelt ausfuehrliche Kapitel zum technischen Hintergrund und behandelt systematisch alle wichtigen Organsysteme: Herz, Kopf und Hals, Thorax und Abdomen mit parenchymalen Organen und Gastrointestinaltrakt. Jedes Protokoll wird tabellarisch praesentiert; dies ermoeglicht dem Benutzer einen schnellen Ueberblick ueber die gewuenschten Anwendungen und die notwendigen Einstellungen des CT-Geraets. Alle Beitraege sind verfasst von anerkannten Experten auf dem Gebiet der CT, die nicht nur ihre reiche klinische Erfahrung in jedem Anwendungsgebiet einbringen, sondern auch Anleitungen fuer Indikationen, Arbeitsablauf, Nachbearbeitung und Rekonstruktionsalgorithmen erarbeitet haben. (orig.)

  15. 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.)

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

    Directory of Open Access Journals (Sweden)

    Manal H. Wahba

    2015-03-01

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

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

    Directory of Open Access Journals (Sweden)

    Jeongmin Lee

    2011-05-01

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

  18. Three-dimensional contrasted visualization of pancreas in rats using clinical MRI and CT scanners.

    Science.gov (United States)

    Yin, Ting; Coudyzer, Walter; Peeters, Ronald; Liu, Yewei; Cona, Marlein Miranda; Feng, Yuanbo; Xia, Qian; Yu, Jie; Jiang, Yansheng; Dymarkowski, Steven; Huang, Gang; Chen, Feng; Oyen, Raymond; Ni, Yicheng

    2015-01-01

    The purpose of this work was to visualize the pancreas in post-mortem rats with local contrast medium infusion by three-dimensional (3D) magnetic resonance imaging (MRI) and computed tomography (CT) using clinical imagers. A total of 16 Sprague Dawley rats of about 300 g were used for the pancreas visualization. Following the baseline imaging, a mixed contrast medium dye called GadoIodo-EB containing optimized concentrations of Gd-DOTA, iomeprol and Evens blue was infused into the distally obstructed common bile duct (CBD) for post-contrast imaging with 3.0 T MRI and 128-slice CT scanners. Images were post-processed with the MeVisLab software package. MRI findings were co-registered with CT scans and validated with histomorphology, with relative contrast ratios quantified. Without contrast enhancement, the pancreas was indiscernible. After infusion of GadoIodo-EB solution, only the pancreatic region became outstandingly visible, as shown by 3D rendering MRI and CT and proven by colored dissection and histological examinations. The measured volume of the pancreas averaged 1.12 ± 0.04 cm(3) after standardization. Relative contrast ratios were 93.28 ± 34.61% and 26.45 ± 5.29% for MRI and CT respectively. We have developed a multifunctional contrast medium dye to help clearly visualize and delineate rat pancreas in situ using clinical MRI and CT scanners. The topographic landmarks thus created with 3D demonstration may help to provide guidelines for the next in vivo pancreatic MRI research in rodents.

  19. Effect of CT scan protocols on x-ray-induced DNA double-strand breaks in blood lymphocytes of patients undergoing coronary CT angiography

    International Nuclear Information System (INIS)

    To compare in vivo DNA lesions induced during helical and sequential coronary computed tomography angiography (CTA) and to evaluate the effect of CT parameters on double-strand break (DSB) levels. Thirty-six patients were examined with various CT protocols and modes (helical scan, n = 27; sequential scan, n = 9) either using a 64-slice dual-source or a 128-slice CT system. Blood samples were obtained before and 30 min after CT. Lymphocytes were isolated, stained against the phosphorylated histone variant γ-H2AX, and DSBs were visualised by using fluorescence microscopy. DSB yields 30 min after CTA ranged from 0.04 to 0.71 per cell and showed a significant correlation to DLP (ρ = 0.81, p < 0.00001). Median DSB yield and median DLP were significantly lower after sequential compared to helical CT examinations (0.11 vs. 0.37 DSBs/cell and 249 vs. 958 mGy cm, p < 0.00001). Additional calcium scoring led to an increase in DLP (p = 0.15) and DSB levels (p = 0.04). DSB levels normalised to the DLP showed a significant correlation to the attenuation of the blood (ρ = 0.53, p = 0.01) and a negative correlation to the body mass index of the patients (ρ = -0.37, p = 0.06). γ-H2AX immunofluorescence microscopy allows one to determine dose-related effects on x-ray-induced DSB levels and to consider individual factors which cannot be monitored by physical dose measurements. (orig.)

  20. Relation of Pulmonary Function Impairment and Coronary Artery Calcification by Multi-detector Computed Tomography in Group Exposed to Inorganic Dusts

    OpenAIRE

    Lee, Won-Jeong; Shin, Jae Hoon; Park, So Young

    2013-01-01

    Background The purpose of this study was to evaluate the relationship of pulmonary function impairment (PFI) and coronary artery calcification (CAC) by multi-detector computed tomography (MDCT), and the effect of pneumoconiosis on CAC or PFI. Methods Seventy-six subjects exposed to inorganic dusts underwent coronary artery calcium scoring by MDCT, spirometry, laboratory tests, and a standardized questionnaire. CAC was quantified using a commercial software (Rapidia ver. 2.8), and all the subj...

  1. 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.

  2. Study of radiation dose to the eye lens by multi-detector row computed tomography of the temporal bone

    International Nuclear Information System (INIS)

    The exposure of the eye lens caused by multi-detector row computed tomography (MDCT) of the temporal bone is a serious problem. Our aim was to evaluate the radiation dose to the eye lens by different scan baselines (orbitomeatal line; OML, acanthiomeatal line; AML) and examine the difference of the depiction of the temporal bone structures. Measurement of the exposure to the eye lens was performed by means of MDCT of the temporal bone with a radio-photoluminescence glass dosimeter using a rand phantom. Moreover, we studied only one volunteer (58-year-old male) who had no symptom and was not suspected of having any ear abnormalities with a two scan baseline. Visualization of the major anatomical structures of the temporal bone (the tympanic portion of the facial nerve canal, the body of the incus, stapes superstructures, vestibule etc.) was performed on the volunteer. The average absorbed dose was 6.42 mGy by the OML and 1.59 mGy by the AML, respectively. With regard to visualization of the temporal bone structures, all structures were of equal quality with the two scan baseline. With the AML line, the radiation dose to the eye lens was reduced to 75%. Therefore, the authors recommended an AML for use for MDCT of the temporal bone. In clinical practice, the optimization of scanning factor (kVp, mAs etc.) and the use of the radio-protection should be implemented for radiation dose reduction of the eye lens by MDCT of the temporal bone. (author)

  3. Cost-effective pediatric head and body phantoms for computed tomography dosimetry and its evaluation using pencil ion chamber and CT dose profiler

    Directory of Open Access Journals (Sweden)

    A Saravanakumar

    2015-01-01

    Full Text Available In the present work, a pediatric head and body phantom was fabricated using polymethyl methacrylate (PMMA at a low cost when compared to commercially available phantoms for the purpose of computed tomography (CT dosimetry. The dimensions of head and body phantoms were 10 cm diameter, 15 cm length and 16 cm diameter, 15 cm length, respectively. The dose from a 128-slice CT machine received by the head and body phantom at the center and periphery were measured using a 100 mm pencil ion chamber and 150 mm CT dose profiler (CTDP. Using these values, the weighted computed tomography dose index (CTDIw and in turn the volumetric CTDI (CTDIv were calculated for various combinations of tube voltage and current-time product. A similar study was carried out using standard calibrated phantom and the results have been compared with the fabricated ones to ascertain that the performance of the latter is equivalent to that of the former. Finally, CTDIv measured using fabricated and standard phantoms were compared with respective values displayed on the console. The difference between the values was well within the limits specified by Atomic Energy Regulatory Board (AERB, India. These results indicate that the cost-effective pediatric phantom can be employed for CT dosimetry.

  4. Contribution to data acquisition software of Eurogram and Diamant multi detectors in an Unix/VXWorks environment; Contribution aux logiciels d`acquisition de donnees des multidetecteurs Eurogam et Diamant dans un environnement reparti Unix/VXWorks

    Energy Technology Data Exchange (ETDEWEB)

    Diarra, C.

    1994-06-01

    Questions on nuclear matter, need to have new performant equipments. Eurogram is a 4 PI gamma radiations multi detector and a precious tool in gamma spectroscopy, but it is necessary to use a charged particles detector and in this aim Diamant is an Eurogram partner. These two multi detectors needed special software data acquisition systems. The whole of acquisition control and management is based on sun stations with unix system. 56 figs., 64 refs.

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

    Institute of Scientific and Technical Information of China (English)

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

    2015-01-01

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

  6. Perfusion CT in childhood stroke—Initial observations and review of the literature

    Energy Technology Data Exchange (ETDEWEB)

    Zebedin, D., E-mail: doris.zebedin@medunigraz.at [Division of Pediatric Radiology, Department of Radiology, University Hospital LKH Graz (Austria); Sorantin, E.; Riccabona, M. [Division of Pediatric Radiology, Department of Radiology, University Hospital LKH Graz (Austria)

    2013-07-15

    Introduction: To report the preliminary results of contrast-enhanced perfusion multi-detector CT for diagnoses of perfusion disturbances in children with clinical suspicion of stroke. Patients and methods: Within the last two years emergency perfusion CT was performed in ten children (age: 8–17 years, male:female = 3:7) for assessment of suspected childhood stroke. These intracranial perfusion CT, intracranial CT-digital subtraction angiography (CT-DSA) and extracranial CT-angiography (CTA) studies were retrospectively reviewed and compared with MRI, follow-up CT, catheter angiography and final clinical diagnosis. The total dose length product (DLP) for the entire examination was recorded. The image quality of perfusion CT-maps, CT-DSA and CTA were evaluated with a subjective three-point scale ranging from very good to non-diagnostic image quality rating perfusion disturbance, intracranial peripheral vessel depiction, and motion- or streak artifacts. Results: In nine of ten children perfusion CT showed no false positive or false negative results. In one of ten children suffering from migraine focal hypo-perfusion was read as perfusion impairment potentially indicating early stroke, but MRI and MRA follow-up were negative. Overall, perfusion-CT with CT-DSA was rated very good in 80% of cases for the detection of perfusion disturbances and vessel anatomy. Conclusions: In comparison to standard CT, contrast-enhanced perfusion CT improves CTs’ diagnostic capability in the emergency examination of children with a strong suspicion of ischemic cerebral infarction.

  7. Perfusion CT in childhood stroke—Initial observations and review of the literature

    International Nuclear Information System (INIS)

    Introduction: To report the preliminary results of contrast-enhanced perfusion multi-detector CT for diagnoses of perfusion disturbances in children with clinical suspicion of stroke. Patients and methods: Within the last two years emergency perfusion CT was performed in ten children (age: 8–17 years, male:female = 3:7) for assessment of suspected childhood stroke. These intracranial perfusion CT, intracranial CT-digital subtraction angiography (CT-DSA) and extracranial CT-angiography (CTA) studies were retrospectively reviewed and compared with MRI, follow-up CT, catheter angiography and final clinical diagnosis. The total dose length product (DLP) for the entire examination was recorded. The image quality of perfusion CT-maps, CT-DSA and CTA were evaluated with a subjective three-point scale ranging from very good to non-diagnostic image quality rating perfusion disturbance, intracranial peripheral vessel depiction, and motion- or streak artifacts. Results: In nine of ten children perfusion CT showed no false positive or false negative results. In one of ten children suffering from migraine focal hypo-perfusion was read as perfusion impairment potentially indicating early stroke, but MRI and MRA follow-up were negative. Overall, perfusion-CT with CT-DSA was rated very good in 80% of cases for the detection of perfusion disturbances and vessel anatomy. Conclusions: In comparison to standard CT, contrast-enhanced perfusion CT improves CTs’ diagnostic capability in the emergency examination of children with a strong suspicion of ischemic cerebral infarction

  8. The role of 64-slice multi-detector computed tomography in the detection of subclinical atherosclerosis of the coronary artery.

    Science.gov (United States)

    Jeong, Hae Chang; Ahn, Youngkeun; Ko, Jum Suk; Lee, Min Goo; Sim, Doo Sun; Park, Keun Ho; Yoon, Nam Sik; Youn, Hyun Ju; Hong, Young Joon; Kim, Kye Hun; Park, Hyung Wook; Kim, Ju Han; Kim, Yun-Hyeon; Jeong, Myung Ho; Cho, Jeong Gwan; Park, Jong Chun; Kang, Jung Chaee

    2010-12-01

    Multi-detector computed tomography (MDCT) has been used for detecting or excluding coronary atherosclerotic stenosis in symptomatic patients. However, the role of MDCT for routine medical examination in asymptomatic, high-risk patients has not been established. We therefore conducted the present study to test the hypothesis that MDCT could be a valuable method for detecting subclinical coronary artery stenosis in asymptomatic patients. An observational, retrospective, single-centre study was conducted with a cohort of 1,529 patients (mean age, 56.4 ± 8.3 years; 1,353 males) who had undergone MDCT as part of their general medical checkups from November 2005 to April 2008. The patients who had a past history of coronary artery disease, typical chest pain, or evidence of myocardial ischemia were excluded. During clinical follow up of these patients, the incidence of subclinical coronary stenosis and the usefulness of MDCT for routine medical examination in asymptomatic patients were investigated. Of the 1,529 enrolled patients, 42.3% had hypertension, 13.5% had diabetes mellitus, 7.7% had hyperlipidemia, and 40.4% were current smokers. Abnormal MDCT findings were noted in 560 (36.6%) patients, who were classified into two groups. One group had the presence coronary calcium with a luminal diameter stenosis of the coronary artery of bridge, and 23 patients (1.5%) presented with significant stenosis. The patients with significant stenosis underwent percutaneous coronary intervention (PCI) with stent implantation. Major adverse cardiac events occurred in only 2 patients who had been treated with PCI during a mean follow-up period of 387 ± 253 days. The incidence of significant subclinical coronary stenosis as detected by MDCT in a general medical check-up was 3.4%, and the false-positive rate of MDCT for detecting significant coronary artery stenosis was 55.8% (29/52). 64-Slice MDCT can be a useful tool for noninvasive evaluation of coronary arteries in

  9. 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.

  10. Low-dose protocol for head CT in evaluation of hydrocephalus in children

    International Nuclear Information System (INIS)

    A suspicion of ventriculo–peritoneal shunt failure is classified as the most common indication for CT in children with hydrocephalus. The main target of the study was to evaluate the diagnostic value of a low-dose protocol and to compare a total DLP received by patients in compared protocols. Our retrospective analysis included 256 examinations performed in patients aged from 1 month to 18 years, with body mass ranging from 3 to 100 kg. The examinations were conducted in the years 2009–2011. A total number of 128 examinations were performed on the basis of the low-dose protocol and 128 according to a standard protocol using the Siemens SOMATOM Definition AS 128-slice scanner. The analysis showed a full value of the diagnostic low-dose protocol with a simultaneous decrease of the total dose of DLP to the average of 40%. Application protocol with lower mAs in assessing the causes of ventriculo-peritoneal shunt failure in children with hydrocephalus is coherent with the valid principles of radiation protection in pediatrics and reduces the total DLP while maintaining a very good diagnostic value

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

    Science.gov (United States)

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

    2012-12-01

    The safety of gadolinium-ethoxybenzyl-diethylenetriamine-pentaacetic-acid (Gd-EOB-DTPA) has been confirmed, but more study is needed to assess the diagnostic accuracy of Gd-EOB-DTPA-enhanced magnetic resonance imaging (MRI) in patients with a hepatocellular carcinoma (HCC) for whom surgical treatment is considered or with a metastatic hepatoma. Research is also needed to examine the rate of detection of hepatic lesions compared to multi-detector computed tomography (MDCT), which is used most frequently to localize and characterize a HCC. Gd-EOB-DTPA-enhanced MRI and iodine-enhanced MDCT imaging were compared for the preoperative detection of focal liver lesions. The clinical usefulness of each method was examined. The current study enrolled 79 patients with focal liver lesions who preoperatively underwent MRI and MDCT. In these patients, there was less than one month between the two diagnostic modalities. Imaging data were taken before and after contrast enhancement in both methods. To evaluate the images, we analyzed the signal-to-noise ratio (SNR) and the contrast-to-noise ratio (CNR) in the lesions and the liver parenchyma. To compare the sensitivity of the two methods, we performed a quantitative analysis of the percentage signal intensity of the liver (PSIL) on a high resolution picture archiving and communication system (PACS) monitor (paired-samples t-test, p Rim enhancement was detected in all metastases (30/30). During the arterial and the delayed phases, good overall agreement between the gadoxetic-acid-enhanced MR and CT was observed (x2 test, p < 0.05). For the preoperative detection of focal liver lesions, Gd-EOB-DTPA-enhanced MRI had a higher diagnostic value and higher detection rate than iodine-enhanced MDCT. The arterial and the delayed dynamic enhancement patterns, and the gadoxetic-acid-enhanced MR imaging can provide information on the possible degree of cellular differentiation of a HCC, adenoma or metastatic tumor.

  12. Significance of CT examination in a dental hospital

    International Nuclear Information System (INIS)

    Computed Tomography (CT) is one of the diagnostic modalities utilized in diagnosing oral, maxillofacial disorders. The Showa University Dental Hospital installed a CT in 1990 and replaced it with a multi-detector CT (MDCT) in 2003. During the last 15 years, the number of maxillofacial disorder cases has increased, and around 1,200 cases per year have been referred to CT in the past five years. The reasons for referral include diagnosis and estimation of the extension of the malignancies in the oral region and the presurgical assessment of dental implant. In addition, cases of cellulitis/abscess induced by odontogenic infection were also referred for CT. The balance of the cost of CT and the payments made by the patients has resulted in profitability. In the future, although other modalities such as MRI and ultrasonography or volumetric CT using a cone-beam can be applied, CT may still play an important role in the management of patients at our dental hospital and some institutions referred to us. (author)

  13. Estimation of frequency and pretest probability of CAD in patients presenting with recent onset chest pain by multi-detector CT angiography

    Directory of Open Access Journals (Sweden)

    Omar Muayad Sultan

    2016-03-01

    Conclusion: CAD was seen in 77.5% in those with recent onset chest pain. Higher incidence of significant CAD was seen in hypertensive and diabetic patients. Family history is still not a reliable factor in our society. Male patient <60 years old has higher incidence of CAD than female in same age group. Pretest probability for CAD is a simple and important test as all patients in higher probability have CAD and most of them have significant disease so it is better to direct referral of them to conventional angiography to gain a benefit from direct intervention, radiation and cost benefit.

  14. Quantification of aortic distensibility in abdominal aortic aneurysm using ECG-gated multi-detector computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Ganten, Maria-Katharina [Deutsches Krebsforschungszentrum, Department of Radiology, Medical Physics in Radiology, Heidelberg (Germany); Ruprecht-Karls-University of Heidelberg, Department of Diagnostic Radiology, Heidelberg (Germany); Krautter, Ute; Tengg-Kobligk, Hendrik von; Delorme, Stefan; Kauczor, Hans-Ulrich [Deutsches Krebsforschungszentrum, Department of Radiology, Medical Physics in Radiology, Heidelberg (Germany); Boeckler, Dittmar; Schumacher, Hardy [Ruprecht-Karls-University of Heidelberg, Department of Vascular and Endovascular Surgery, Heidelberg (Germany); Stiller, Wolfram; Bock, Michael [Deutsches Krebsforschungszentrum, Department of Medical Physics in Radiology, Medical Physics in Radiology, Heidelberg (Germany); Kauffmann, Guenter W. [Ruprecht-Karls-University of Heidelberg, Department of Diagnostic Radiology, Heidelberg (Germany)

    2008-05-15

    To detect distensibility changes that might be an indicator for an increased risk of rupture, cross-sectional area changes of abdominal aortic aneurysms (AAA) have been determined using ECG-gated CT. Distensibility measurements of the aorta were performed in 67 patients with AAA. Time-resolved images were acquired with a four detector-row CT system using a modified CT-angiography protocol. Pulsatility-related cross-sectional area changes were calculated above and at AAA level by semiautomatic segmentation; distensibility values were obtained using additional systemic blood pressure measurements. Values were compared for small Oe< 5 cm (n=44) and large Oe> 5 cm (n = 23) aneurysms. The aorta could be segmented successfully in all patients. Upstream AAA distensibility D was significantly higher than at AAA level for both groups: means above AAA (at AAA) D{sub above} = (1.3 {+-}0.8) .10 {sup -5} Pa {sup -1} (D{sub AAA} = (0.6 {+-}0.5) .10 {sup -5} Pa {sup -1}) t-test p{sub D}<0.0001. Differences of the distensibility between smaller and larger aneurysms were not found to be significant. Distensibility can be measured non-invasively with ECG-gated CT. The reduction of distensibility within aneurysms compared to normal proximal aorta is subtle; the lack of difference between both small and large aneurysms suggests that this reduction occurs early in the aneurysm's development. Hence, reduced distensibility might be a predictive parameter in patients with high risk of aortic disease. (orig.)

  15. Endobronchial valves in severe emphysematous patients: CT evaluation of lung fissures completeness, treatment radiological response and quantitative emphysema analysis Valvas endobrônquicas em pacientes com enfisema grave: avaliação por TC da completude das fissuras pulmonares, resposta radiológica ao tratamento e análise quantitativa do enfisema

    OpenAIRE

    Marcel Koenigkam-Santos; Wagner Diniz de Paula; Daniela Gompelmann; Hans-Ulrich Kauczor; Claus Peter Heussel; Michael Puderbach

    2013-01-01

    OBJECTIVE: To evaluate lung fissures completeness, post-treatment radiological response and quantitative CT analysis (QCTA) in a population of severe emphysematous patients submitted to endobronchial valves (EBV) implantation. MATERIALS AND METHODS: Multi-detectors CT exams of 29 patients were studied, using thin-section low dose protocol without contrast. Two radiologists retrospectively reviewed all images in consensus; fissures completeness was estimated in 5% increments and post-EBV radio...

  16. Cardiac CT for the assessment of chest pain: Imaging techniques and clinical results

    Energy Technology Data Exchange (ETDEWEB)

    Becker, Hans-Christoph, E-mail: christoph.becker@med.uni-muenchen.de [Ludwig-Maximilians-University, Grosshadern Clinic, Department of Clinical Radiology, Marchioninistr. 15, 81377 Munich (Germany); Johnson, Thorsten [Ludwig-Maximilians-University, Grosshadern Clinic, Department of Clinical Radiology, Marchioninistr. 15, 81377 Munich (Germany)

    2012-12-15

    Immediate and efficient risk stratification and management of patients with acute chest pain in the emergency department is challenging. Traditional management of these patients includes serial ECG, laboratory tests and further on radionuclide perfusion imaging or ECG treadmill testing. Due to the advances of multi-detector CT technology, dedicated coronary CT angiography provides the potential to rapidly and reliably diagnose or exclude acute coronary artery disease. Life-threatening causes of chest pain, such as aortic dissection and pulmonary embolism can simultaneously be assessed with a single scan, sometimes referred to as “triple rule out” scan. With appropriate patient selection, cardiac CT can accurately diagnose heart disease or other sources of chest pain, markedly decrease health care costs, and reliably predict clinical outcomes. This article reviews imaging techniques and clinical results for CT been used to evaluate patients with chest pain entering the emergency department.

  17. 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 ...

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

    Directory of Open Access Journals (Sweden)

    Diego Haberman

    2008-09-01

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

  19. Visualization of congenital thoracic vascular anomalies using multi-detector row computed tomography and two- and three-dimensional post-processing

    Energy Technology Data Exchange (ETDEWEB)

    Schertler, Thomas [Department of Medical Radiology, Institute of Diagnostic Radiology, University Hospital Zurich (Switzerland); Wildermuth, Simon [Institute of Diagnostic Radiology, Kantonsspital St.Gallen (Switzerland)]. E-mail: Simon.Wildermuth@kssg.ch; Teodorovic, Ninoslav [Department of Medical Radiology, Institute of Diagnostic Radiology, University Hospital Zurich (Switzerland); Mayer, Dieter [Division of Cardiovascular Surgery, University Hospital Zurich (Switzerland); Marincek, Borut [Department of Medical Radiology, Institute of Diagnostic Radiology, University Hospital Zurich (Switzerland); Boehm, Thomas [Department of Medical Radiology, Institute of Diagnostic Radiology, University Hospital Zurich (Switzerland); Department of Medical Radiology, Institute of Diagnostic Radiology, Kantonsspital Chur (Switzerland)

    2007-01-15

    Anomalies of the vascular system are caused by false embryogenesis and are therefore present from birth. Single-detector row spiral computed tomography angiography (CTA) and multi-detector row computed tomography angiography (MDCTA) have gained increasing importance in the non-invasive assessment of vascular pathologies and replace conventional angiography in many cases. High-resolution volumetric datasets that are acquired during a single breath-hold give the possibility of two- (2D) and three-dimensional (3D)-post-processing. Due to post-processing, even complex vascular malformations are visualized in an understandable way. Furthermore, CTA, in contrast to conventional angiography, depicts not only the vascular structures but also allows assessment of the surrounding anatomical structures. We present cases of rare congenital anomalies of the thoracic vessels using MDCT with special respect to 2D- and 3D-post-processing.

  20. Guideline for appropriate use of cardiac CT in heart disease

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Young Jin; Hong, Yoo Jin [Dept. of Radiology, Severance Hospital, Yonsei University College of Medicine, Seoul (Korea, Republic of); Yong, Hwan Seok [Dept. of Radiology, Korea University Guro Hospital, Korea University College of Medicine, Seoul (Korea, Republic of); Kim, Sung Mok [Dept. of Radiology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of); Kim, Jeong A [Dept. of Radiology, Ilsan Paik Hospital, Inje University College of Medicine, Goyang (Korea, Republic of); Yang, Dong Hyun [Dept. of Radiology, Asan Medical Center, University of Ulsan College of Medicine, Seoul (Korea, Republic of)

    2014-02-15

    Heart disease is one of the leading causes of deaths in Korea, along with malignant neoplasms and cerebrovascular diseases. The proper diagnosis and management for patients with suspected heart diseases should be warranted for the public health care. Advances in CT technology have allowed detailed images of the heart to be obtained, which enable evaluations not only of the coronary arteries but also of other cardiac structures. Currently, the latest multi-detector CT machines are widespread around Korea. The appropriate use of cardiac CT may lead to improvements of the physicians' medical performances and to reduce medical costs which eventually contribute to promotions of public health. However, until now, there has been no guidelines regarding the appropriate use of cardiac CT in Korea. We intend to provide guidelines for the appropriate use of cardiac CT in heart diseases based on scientific data. The purpose of this guideline is to assist the clinicians and other health professionals when using cardiac CT for diagnosis and treatments of heart diseases.

  1. CT findings in patients with chronic thromboembolic pulmonary hypertension

    International Nuclear Information System (INIS)

    Chronic thromboembolic pulmonary hypertension (CTEPH) is thought to be a rare complication of pulmonary embolism. However, it was recently demonstrated that CTEPH is more common than previously thought after pulmonary embolism. Without treatment, CTEPH is associated with a very high mortality rate. Making the correct diagnosis early is essential, because there is a potential curative treatment in the form of pulmonary thromboendarterectomy (PTE). Because of the unspecific clinical symptoms of CTEPH, the different imaging modalities play a crucial role in diagnosis making. Since the introduction of the multi-detector CT technology, CT has become an important part in the diagnostic work up of pulmonary embolism and CTEPH and is often used as a first-line diagnostic tool. CT is not only a reliable tool for the diagnosis of CTEPH, but also is helpful in estimating the operability of these patients. PTE is still associated with a mortality rate of about 10%. Particularly an insufficient decrease of the pulmonary vascular resistance after PTE leads to a very high mortality rate. Therefore, it is crucial to correlate the degree of the surgical accessible obstruction of the pulmonary vasculature with the degree of pulmonary hypertension in deciding for or against PTE. The aim of this review is to describe the CT findings in patients with CTEPH and their use in differentiating CTEPH from other diseases like acute pulmonary embolism and primary pulmonary hypertension. Moreover, the correlation of different CT imaging features with surgical success after PTE will be discussed. (orig.)

  2. Serial CT Findings of Paragonimus Infested Dogs and the Micro-CT Findings of the Worm Cysts

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Chang Hyun; Im, Jung Gi; Goo, Jin Mo; Lee, Hyun Ju; Hong, Sung Tae; Shen, Cheng Hua; Chung, Doo Hyun; Son, Kyu Ri; Chang, Jung Min; Eo, Hong [Seoul National University College of Medicine, Seoul (Korea, Republic of)

    2007-10-15

    To investigate the serial CT findings of Paragonimus westermani infected dogs and the microscopic structures of the worm cysts using Micro-CT. This study was approved by the committee on animal research at our institution. Fifteen dogs infected with P. westermani underwent serial contrast-enhanced CT scans at pre-infection, after 10 days of infection, and monthly thereafter until six months for determining the radiologic-pathologic correlation. Three dogs (one dog each time) were sacrificed at 1, 3 and 6 months, respectively. After fixation of the lungs, both multi-detector CT and Micro-CT were performed for examining the worm cysts. The initial findings were pleural effusion and/or subpleural groundglass opacities or linear opacities at day 10. At day 30, subpleural and peribronchial nodules appeared with hydropneumothorax and abdominal or chest wall air bubbles. Cavitary change and bronchial dilatation began to be seen on CT scan at day 30 and this was mostly seen together with mediastinal lymphadenopathy at day 60. Thereafter, subpleural ground-glass opacities and nodules with or without cavitary changes were persistently observed until day 180. After cavitary change of the nodules, the migratory features of the subpleural or peribronchial nodules were seen on all the serial CT scans. Micro-CT showed that the cyst wall contained dilated interconnected tubular structures, which had communications with the cavity and the adjacent distal bronchus. The CT findings of paragonimiasis depend on the migratory stage of the worms. The worm cyst can have numerous interconnected tubular channels within its own wall and these channels have connections with the cavity and the adjacent distal bronchus.

  3. Comparison of ventilation/perfusion scintigraphy and multi-detector computerized tomography in diagnosis of asymptomatic pulmonary embolism after deep vein thrombosis

    Directory of Open Access Journals (Sweden)

    Eflatun Yücedağ

    2014-03-01

    Full Text Available Objective: Pulmonary thromboembolism (PTE named due to migration of clots formed in systemic venous system to pulmonary vascular bed is a serious clinical table. After acute DVT, asymptomatic PTE is seen about 40-60% and this situation can not be discovered because of silent clinical course. In this study, we aimed to compare sensivity and spesifity of multi detector computerized tomography (MDCT, which is used extensively in recent years, with ventilation-perfusion (V/P scintigraphy which is used formerly for diagnosis of asymptomatic PTE developed after acute lower extremity DVT. Methods: The study was carried out 25 patients who were admitted to our clinic and treated for lower extremity acute DVT. Pregnants, and cases with recurrent DVT, presence of symptomatic PTE during admission, thrombosis extending to vena cava, and history of passed PTE were excluded from the study. DVTs in patients were diagnosed by color doppler, and confirmed by D-dimer test. After patients’s admission, V/P scintigraphy and MDCT were used to detects asymptomatic PTE at 1st and 8 th day of the admission. Results: D-dimer was measured as higher in 24 of 25 patients with asemptomatic PTE. Ten patients were diagnosed by MDCT. Development of asymptomatic PTE related to acute DVT was determined as 40%. Conclusion: In terms of diagnostic value, MDCT was found more useful than V/P scintigraphy.

  4. Right atrial volume calculated by multi-detector computed tomography. Useful predictor of atrial fibrillation recurrence after pulmonary vein catheter ablation

    International Nuclear Information System (INIS)

    We investigated whether right atrial (RA) volume could be used to predict the recurrence of atrial fibrillation (AF) after pulmonary vein catheter ablation (CA). We evaluated 65 patients with paroxysmal AF (mean age, 60+10 years, 81.5% male) and normal volunteers (57±14 years, 41.7% male). Sixty-four-slice multi-detector computed tomography was performed for left atrial (LA) and RA volume estimations before CA. The recurrence of AF was assessed for 6 months after the ablation. Both left and right atrial volumes were larger in the AF patients than the normal volunteers (LA: 99.7+33.2 ml vs. 59.7+17.4 ml; RA: 82.9+35.7 ml vs. 43.9+12 ml; P100 ml) for predicting the recurrence of AF was 81.3% in 13 of 16 patients with AF recurrence, and the specificity was 69.4% in 34 of 49 patients without recurrence. The sensitivity with large RA volumes (>87 ml) was 81.3% in 13 of 16 patients with AF recurrence, and the specificity was 75.5% in 37 of 49 patients without recurrence. RA volume is a useful predictor of the recurrence of AF, similar to LA volume. (author)

  5. The feasibility of axial and coronal combined imaging using multi-detector row computed tomography for the diagnosis and treatment of a primary spontaneous pneumothorax

    Directory of Open Access Journals (Sweden)

    Kim Do

    2011-05-01

    Full Text Available Abstract Background The preoperative detection of emphysema like changes (ELCs is necessary for the successful treatment of pneumothorax. High resolution computed tomography (HRCT has been used for the preoperative detection of ELCs. However, the traditional HRCT method uses only the axial view, which is perpendicular to the distribution of ELCs. This is not an ideal diagnostic method for the evaluation of ELCs. Methods Forty-eight patients with pneumothorax had multi-detector computed tomography (MDCT reconstruction using the coronal view. ELCs were evaluated in the axial and coronal view by a radiologist. A surgeon performed intra-operative examinations of the ELCs. The sensitivity of the different views was compared. Results The detection sensitivity was 74.4% (70/94 for the axial view and 91.5% (86/94 for the axial-coronal combined view. The intra-operative detection rate was 95.7% (90/94. The preoperative detection of ELCs on the axial-coronal combined view was significantly higher than on the conventional axial view alone (p Conclusions Evaluation of ELCs on the axial and coronal combined HRCT improved the sensitivity of preoperative detection of ELCs compared to the conventional single axial HRCT. This increased sensitivity will help decrease the recurrence with VATS.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2007-11-15

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

  7. The Interobserver Agreement between Residents and Experienced Radiologists for Detecting Pulmonary Embolism and DVT with Using CT Pulmonary Angiography and Indirect CT Venography

    Energy Technology Data Exchange (ETDEWEB)

    Yavas, Ulas Savas; Calisir, Cuneyt; Ozkan; Ibrahim Ragip [Eskisehir Osmangazi University, Eskisehir (Turkmenistan)

    2008-12-15

    We wanted to prospectively evaluate the interobserver agreement between radiology residents and expert radiologists for interpreting CT images for making the diagnosis of pulmonary embolism (PE). We assessed 112 consecutive patients, from April 2007 to August 2007, who were referred for combined CT pulmonary angiography and indirect CT venography for clinically suspected acute PE. CT scanning was performed with a 64x0.5 collimation multi-detector CT scanner. The CT studies were initially interpreted by the radiology residents alone and then the CT images were subsequently interpreted by a consensus of the resident plus an experienced general radiologist and an experienced chest radiologist. Two of the 112 CTs were unable to be interpreted (1.7%). Pulmonary artery clots were seen on 36 of the thoracic CT angiographies (32%). The interobserver agreement between the radiology residents and the consensus interpretation was good (a kappa index of 0.73). All of the disagreements (15 cases) were instances of overcall by the resident on the initial interpretation. Deep venous thrombosis was detected in 72% (26 of 36) of the patients who had PE seen on thoracic CT. The initial and consensus interpretations of the CT venography images disagreed for two cases (kappa statistic: 0.96). It does not seem adequate to base the final long-term treatment of PE on only the resident's reading, as false positives occurred in 13% of such cases. Timely interpretation of the CT pulmonary angiography and CT venography images should be performed by experienced radiologists for the patients with suspected PE.

  8. Perfusion computed tomography for diffuse liver diseases; Perfusions-CT bei diffusen Lebererkrankungen

    Energy Technology Data Exchange (ETDEWEB)

    Schmidt, S.A.; Juchems, M.S. [Universitaetsklinikum Ulm, Klinik fuer Diagnostische und Interventionelle Radiologie, Ulm (Germany)

    2012-08-15

    Perfusion computed tomography (CT) has its main application in the clinical routine diagnosis of neuroradiological problems. Polyphase multi-detector spiral computed tomography is primarily used in liver diagnostics. The use of perfusion CT is also possible for the diagnostics and differentiation of diffuse hepatic diseases. The differentiation between cirrhosis and cirrhosis-like parenchymal changes is possible. It also helps to detect early stages of malignant tumors. However, there are some negative aspects, particularly that of radiation exposure. This paper summarizes the technical basics and possible applications of perfusion CT in cases of diffuse liver disease and weighs up the advantages and disadvantages of the examinations. (orig.) [German] Die Perfusions-CT hat ihren hauptsaechlichen Stellenwert bislang in der klinischen Routinediagnostik bei neuroradiologische Fragestellungen. In der Leberdiagnostik kommt v. a. die mehrphasige Multidetektor-Spiral-CT-Untersuchung zum Einsatz. Die Anwendung der Perfusions-CT ist auch bei der Diagnostik und Differenzierung diffuser Lebererkrankungen moeglich. Die Unterscheidung zwischen einer Leberzirrhose und zirrhoseaehnlichen Parenchymveraenderungen ist mit der Perfusions-CT moeglich. Ebenso liefert sie einen wertvollen Beitrag zur Diagnostik bei der Frueherkennung entstehender maligner Herdbefunde. Diesen Vorteilen stehen jedoch auch einige negative Aspekte gegenueber, insbesondere die relativ hohe Strahlenexposition. Die vorliegende Arbeit soll einen Ueberblick ueber die technischen Grundlagen und die Anwendungsmoeglichkeiten der Perfusions-CT bei diffusen Lebererkrankungen geben sowie die Vor- und Nachteile der Untersuchung gegeneinander abwaegen. (orig.)

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-01-15

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

  10. 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

  11. 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 ...

  12. Evaluation to Obtain the Image According to the Spatial Domain Filtering of Various Convolution Kernels in the Multi-Detector Row Computed Tomography

    International Nuclear Information System (INIS)

    Our objective was to evaluate the image of spatial domain filtering as an alternative to additional image reconstruction using different kernels in MDCT. Derived from thin collimated source images were generated using water phantom and abdomen B10(very smooth), B20(smooth), B30(medium smooth), B40 (medium), B50(medium sharp), B60(sharp), B70(very sharp) and B80(ultra sharp) kernels. MTF and spatial resolution measured with various convolution kernels. Quantitative CT attenuation coefficient and noise measurements provided comparable HU(Hounsfield) units in this respect. CT attenuation coefficient(mean HU) values in the water were values in the water were 1.1∼1.8 HU, air(-998∼-1000 HU) and noise in the water(5.4∼44.8 HU), air(3.6∼31.4 HU). In the abdominal fat a CT attenuation coefficient(-2.2∼0.8 HU) and noise(10.1∼82.4 HU) was measured. In the abdominal was CT attenuation coefficient(53.3∼54.3 HU) and noise(10.4∼70.7 HU) in the muscle and in the liver parenchyma of CT attenuation coefficient(60.4∼62.2 HU) and noise (7.6∼63.8 HU) in the liver parenchyma. Image reconstructed with a convolution kernel led to an increase in noise, whereas the results for CT attenuation coefficient were comparable. Image scanned with a high convolution kernel(B80) led to an increase in noise, whereas the results for CT attenuation coefficient were comparable. Image medications of image sharpness and noise eliminate the need for reconstruction using different kernels in the future. Adjusting CT various kernels, which should be adjusted to take into account the kernels of the CT undergoing the examination, may control CT images increase the diagnostic accuracy.

  13. Assessment of right ventricular function for patients with rheumatic mitral stenosis by 64-slice multi-detector row computed tomography: comparison with magnetic resonance imaging

    Institute of Scientific and Technical Information of China (English)

    ZHANG Xiao-chun; YANG Zhi-gang; GUO Yin-kun; ZHANG Rui-ming; WANG Jian; ZHOU Dai-quan; CHENG Lin; CHEN Lin

    2012-01-01

    Background Right ventricular (RV) dysfunction ensues due to rheumatic mitral stenosis (RMS).The evaluation of RV function is clinically important for the diagnosis,treatment,and follow-up for patients with different degrees of RMS.Thepurpose of this study was to determine whether the 64-slice multi-detector row computed tomography (64-slice MDCT)can assess the RV function in RMS with high accuracy and reproducibility when compared to MR imaging (MRI).Methods Right ventricular end-diastolic and end-systolic volumes (RV-EDV and RV-ESV),stroke volume (RV-SV),ejection fraction (RV-EF),cardiac output (RV-CO),and wall mass (RV-Mass) were measured with dedicated cardiac analysis software on 64-slice MDCT and compared with values measured with MRI in 43 consecutive patients with RMS.Agreement between MRI and 64-MDCT results were compared with Bland and Altman analysis and linear regression analysis.Repeated measurements were performed to determine intraobserver and interobserver variability.Results No significant differences were revealed in calculated RV function parameters between the two methods.RV-EDV,RV-ESV,RV-SV,RV-EF,RV-CO,and RV-Mass by 64-slice MDCT were similar to those by MRI (P>0.05).There were good correlations (r=0.98,0.97,0.96,0.96,0.95 and 0.77,respectively) and close agreement (bias=-0.2 ml,-1.0ml,0.8 ml,0.5%,26.1 ml,and 0.5 g,respectively,P>0.05).The variability in 64-slice MDCT measurements was similar to that in MRI values.Conclusion ECG-gated 64-slice MDCT could assess the RV function in RMS with high accuracy and reproducibility when compared to MRI.

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

    International Nuclear Information System (INIS)

    Multi-detector computed tomography (MDCT) permits detection of coronary plaque. However, noise and blurring impair accuracy and precision of plaque measurements. The aim of the study was to evaluate MDCT post-processing based on non-linear image deblurring and edge-preserving noise suppression for measurements of plaque size. Contrast-enhanced MDCT coronary angiography was performed in four subjects (mean age 55 ± 5 years, mean heart rate 54 ± 5 bpm) using a 16-slice scanner (Siemens Sensation 16, collimation 16 x 0.75 mm, gantry rotation 420 ms, tube voltage 120 kV, tube current 550 mAs, 80 mL of contrast). Intravascular ultrasound (IVUS; 40 MHz probe) was performed in one vessel in each patient and served as a reference standard. MDCT vessel cross-sectional images (1 mm thickness) were created perpendicular to centerline and aligned with corresponding IVUS images. MDCT images were processed using a deblurring and edge-preserving noise suppression algorithm. Then, three independent blinded observers segmented lumen and outer vessel boundaries in each modality to obtain vessel cross-sectional area and wall area in the unprocessed MDCT cross-sections, post-processed MDCT cross-sections and corresponding IVUS. The wall area measurement difference for unprocessed and post-processed MDCT images relative to IVUS was 0.4 ± 3.8 mm2 and -0.2 ± 2.2 mm2 (p 2, respectively. In conclusion, MDCT permitted accurate in vivo measurement of wall area and vessel cross-sectional area as compared to IVUS. Post-processing to reduce blurring and noise reduced variability of wall area measurements and reduced measurement bias for both wall area and vessel cross-sectional area

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

    Institute of Scientific and Technical Information of China (English)

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

    2006-01-01

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

  16. Estimation of absorbed doses from paediatric cone-beam CT scans: MOSFET measurements and Monte Carlo simulations.

    Science.gov (United States)

    Kim, Sangroh; Yoshizumi, Terry T; Toncheva, Greta; Frush, Donald P; Yin, Fang-Fang

    2010-03-01

    The purpose of this study was to establish a dose estimation tool with Monte Carlo (MC) simulations. A 5-y-old paediatric anthropomorphic phantom was computed tomography (CT) scanned to create a voxelised phantom and used as an input for the abdominal cone-beam CT in a BEAMnrc/EGSnrc MC system. An X-ray tube model of the Varian On-Board Imager((R)) was built in the MC system. To validate the model, the absorbed doses at each organ location for standard-dose and low-dose modes were measured in the physical phantom with MOSFET detectors; effective doses were also calculated. In the results, the MC simulations were comparable to the MOSFET measurements. This voxelised phantom approach could produce a more accurate dose estimation than the stylised phantom method. This model can be easily applied to multi-detector CT dosimetry. PMID:19889800

  17. Ambient dose measurement in some CT departments in Khartoum State

    International Nuclear Information System (INIS)

    Computerized Tomography (CT) is now one of the most important radiological examinations world wide.The frequency of CT examinations is increasing rapidly from 2% of all radiological examinations in some countries a decade age to 10-15% now. During the imaging procedure, staff may expose to a significant dose. Therefore, ambient dose measurement is important in the shortage of regular personal monitoring in sudan. This study intended to evaluate the ambient dose at some CT departments (Medical Military hospital, Alamal National Hospital, Elnelin Diagnostic Center and Modern Medical Centre). These departments were equipped with daul, 16 and 64 multi detector CT machines. A survey meter (Radios) was used to measure ambient doses in three locations: Doors, Control Rooms and Adjacent Rooms. The ambient dose equivalent (scatter dose) was measured at various distances from the isocenter of the CT unit at various angles to establish isodose cartography. The mean and range of radiation at control room is 10.00-0.20 and mean (7.05μSv/hr,) reception 1.0-0 (0.40) and doors 4.00-100.00 (73.5) for height 1 meter above the ground. For height 2 meters at control room 0-10.00 (6,75), reception 0-90.00 (30) at door 9.00-90.00 (49.50). This study confirms that low levels of radiation dose are received by staff during CT imaging and these levels are within safe limits as prescribed by the national and international regulations. (Author)

  18. [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

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

    Directory of Open Access Journals (Sweden)

    Sarno Giovanna

    2007-12-01

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

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

    Institute of Scientific and Technical Information of China (English)

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

    2014-01-01

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

  1. Iodized oil uptake assessment with cone-beam CT in chemoembolization of small hepatocellular carcinomas

    Institute of Scientific and Technical Information of China (English)

    Ung Bae Jeon; Jun Woo Lee; Ki Seok Choo; Chang Won Kim; Suk Kim; Tae Hong Lee; Yeon Joo Jeong; Dae Hwan Kang

    2009-01-01

    AIM: To evaluate the utility of assessing iodized oil uptake with cone-beam computed tomography (CT) in transarterial chemoembolization (TACE) for small hepatocellular carcinoma (HCC). METHODS: Cone-beam CT provided by a biplane flatpanel detector angiography suite was performed on eighteen patients (sixteen men and two women; 41-76 years; mean age, 58.9 years) directly after TACE for small HCC (26 nodules under 30 mm; mean diameter, 11.9 mm; range, 5-28 mm). The pre-procedural locations of the tumors were evaluated using triphasic multi-detector row helical computed tomography (MDCT). The tumor locations on MDCT and the iodized oil uptake by the tumors were analyzed on cone-beam CT and on spot image directly after the procedures. RESULTS: All lesions on preprocedural MDCT were detected using iodized oil uptake in the lesions on conebeam CT (sensitivity 100%, 26/26). Spot image depicted iodized oil uptake in 22 of the lesions (sensitivity 85%). The degree of iodized oil uptake was overestimated (9%, 2/22) or underestimated (14%, 3/22) on spot image in five nodules compared with that of cone-beam CT. CONCLUSION: Cone-beam CT is a useful and convenient tool for assessing the iodized oil uptake of small hepatic tumors (< 3 cm) directly after TACE.

  2. CT liver volumetry using geodesic active contour segmentation with a level-set algorithm

    Science.gov (United States)

    Suzuki, Kenji; Epstein, Mark L.; Kohlbrenner, Ryan; Obajuluwa, Ademola; Xu, Jianwu; Hori, Masatoshi; Baron, Richard

    2010-03-01

    Automatic liver segmentation on CT images is challenging because the liver often abuts other organs of a similar density. Our purpose was to develop an accurate automated liver segmentation scheme for measuring liver volumes. We developed an automated volumetry scheme for the liver in CT based on a 5 step schema. First, an anisotropic smoothing filter was applied to portal-venous phase CT images to remove noise while preserving the liver structure, followed by an edge enhancer to enhance the liver boundary. By using the boundary-enhanced image as a speed function, a fastmarching algorithm generated an initial surface that roughly estimated the liver shape. A geodesic-active-contour segmentation algorithm coupled with level-set contour-evolution refined the initial surface so as to more precisely fit the liver boundary. The liver volume was calculated based on the refined liver surface. Hepatic CT scans of eighteen prospective liver donors were obtained under a liver transplant protocol with a multi-detector CT system. Automated liver volumes obtained were compared with those manually traced by a radiologist, used as "gold standard." The mean liver volume obtained with our scheme was 1,520 cc, whereas the mean manual volume was 1,486 cc, with the mean absolute difference of 104 cc (7.0%). CT liver volumetrics based on an automated scheme agreed excellently with "goldstandard" manual volumetrics (intra-class correlation coefficient was 0.95) with no statistically significant difference (p(Fliver volumes.

  3. 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 ...

  4. 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 ...

  5. The Value and Reason in CT Diagnosis of Transient Hepatic Perfusion Disorders in Patients with Hepatic Abscess%肝脓肿不同时相一过性灌注的 CT 表现及原因探讨

    Institute of Scientific and Technical Information of China (English)

    孙瑜

    2014-01-01

    目的:探讨肝脓肿CT 三期增强检查中伴发的异常灌注(THPD)征象的表现及产生机制。方法:回顾性分析27例经临床证实、CT 增强显示 T HPD征象的图像资料,对不同时相出现 T HPD病例的CT 表现、原因及其发生机制进行分析。结果:CT 增强显示动脉期17例高灌注 T HPD ,2例同时有高灌注和低灌注 T HPD两种表现,1例单纯低灌注 T HPD ;门脉期表现为高灌注 T HPD 者3例,单纯低灌注 T HPD 者4例。结论:动脉期T HPD有助于肝脓肿诊断,T HPD表现多样,与其产生机制多种、病程长短有关。%Objective:ToevaluatethetriphasicMSCTfeaturesoftransienthepaticperfusiondisorders (THPD)inpatientswithhepaticabscessand explore its main mechanism .Methods :Analyze the pre-contrast and dynamic contrast scan T HPD feature of 27 hepatic abscess patients (12 male ,15 female ,age ranging from 40 to 83 ,mean 60 .7 ± 11 .9 years) who were scaned by a 128 -slice MSCT scanner and confirmed by clinical .Results :Hyper-perfusion THPD in 17 patients ,hyper -and hypo -perfusion THPD in 2 patients ,and hypo -perfusion THPD in 1 patient were shown on arterial phase scans .Others were only shown on portal venous phase scans ,including hyper -perfusion THPD in 3 patients ,and hypo -perfusion THPD in 4 patients .Conclusion:The THPD accompanied with hepatic abscess shows various features ,which may be caused by different pathogenic mechanisms and courses of disease .

  6. Coronary CT angiography using prospective ECG triggering. High diagnostic accuracy with low radiation dose; CT-Angiographie der Koronarien mit prospektivem EKG-Triggering. Hohe diagnostische Genauigkeit bei niedriger Strahlendosis

    Energy Technology Data Exchange (ETDEWEB)

    Arnoldi, E. [Medical University of South Carolina, Charleston, Department of Radiology and Radiological Science, Charleston (United States); Klinikum der Ludwigs-Maximilians-Universitaet Muenchen, Campus Grosshadern, Institut fuer Klinische Radiologie, Muenchen (Germany); Ramos-Duran, L.; Abro, J.A.; Costello, P. [Medical University of South Carolina, Charleston, Department of Radiology and Radiological Science, Charleston (United States); Zwerner, P.L.; Schoepf, U.J. [Medical University of South Carolina, Charleston, Department of Radiology and Radiological Science, Charleston (United States); Medical University of South Carolina, Charleston, Department of Medicine, Division of Cardiology, Charleston (United States); Nikolaou, K.; Reiser, M.F. [Klinikum der Ludwigs-Maximilians-Universitaet Muenchen, Campus Grosshadern, Institut fuer Klinische Radiologie, Muenchen (Germany)

    2010-06-15

    The purpose of this study was to evaluate the diagnostic performance of coronary CT angiography (coronary CTA) using prospective ECG triggering (PT) for the detection of significant coronary artery stenosis compared to invasive coronary angiography (ICA). A total of 20 patients underwent coronary CTA with PT using a 128-slice CT scanner (Definition trademark AS+, Siemens) and ICA. All coronary CTA studies were evaluated for significant coronary artery stenoses ({>=}50% luminal narrowing) by 2 observers in consensus using the AHA-15-segment model. Findings in CTA were compared to those in ICA. Coronary CTA using PT had 88% sensitivity in comparison to 100% with ICA, 95% to 88% specificity, 80% to 92% positive predictive value and 97% to 100% negative predictive value for diagnosing significant coronary artery stenosis on per segment per patient analysis, respectively. Mean effective radiation dose-equivalent of CTA was 2.6{+-}1 mSv. Coronary CTA using PT enables non-invasive diagnosis of significant coronary artery stenosis with high diagnostic accuracy in comparison to ICA and is associated with comparably low radiation exposure. (orig.) [German] Ziel unserer Untersuchungen war es, die CT-Angiographie der Koronarien (Koronar-CTA) unter Verwendung des prospektiven EKG-Triggerings (PT) hinsichtlich ihrer diagnostischen Genauigkeit zur Detektion signifikanter Koronarstenosen mit der Herzkatheteruntersuchung (HK) zu vergleichen. Bei 20 Patienten wurden eine Koronar-CTA mit PT an einem 128-Zeilen-CT-Scanner (Definition trademark, AS+, Siemens) und eine HK durchgefuehrt. Alle CTA-Studien wurden von 2 Radiologen bzgl. signifikanter Koronarstenosen ({>=}50% Lumeneinengung) anhand des 15-Segment-Modells der American Heart Association (AHA) im Konsensus ausgewertet. Die Ergebnisse der CTA wurden mit den Befunden der HK verglichen. Die Koronar-CTA mit PT zeigte fuer die Diagnose signifikanter Stenosen im Vergleich zur HK eine Sensitivitaet von 88 bzw. 100%, eine Spezifitaet

  7. 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.)

  8. Technical Note: Measuring contrast- and noise-dependent spatial resolution of an iterative reconstruction method in CT using ensemble averaging

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Lifeng, E-mail: yu.lifeng@mayo.edu; Vrieze, Thomas J.; Leng, Shuai; Fletcher, Joel G.; McCollough, Cynthia H. [Department of Radiology, Mayo Clinic, Rochester, Minnesota 55905 (United States)

    2015-05-15

    Purpose: The spatial resolution of iterative reconstruction (IR) in computed tomography (CT) is contrast- and noise-dependent because of the nonlinear regularization. Due to the severe noise contamination, it is challenging to perform precise spatial-resolution measurements at very low-contrast levels. The purpose of this study was to measure the spatial resolution of a commercially available IR method using ensemble-averaged images acquired from repeated scans. Methods: A low-contrast phantom containing three rods (7, 14, and 21 HU below background) was scanned on a 128-slice CT scanner at three dose levels (CTDI{sub vol} = 16, 8, and 4 mGy). Images were reconstructed using two filtered-backprojection (FBP) kernels (B40 and B20) and a commercial IR method (sinogram affirmed iterative reconstruction, SAFIRE, Siemens Healthcare) with two strength settings (I40-3 and I40-5). The same scan was repeated 100 times at each dose level. The modulation transfer function (MTF) was calculated based on the edge profile measured on the ensemble-averaged images. Results: The spatial resolution of the two FBP kernels, B40 and B20, remained relatively constant across contrast and dose levels. However, the spatial resolution of the two IR kernels degraded relative to FBP as contrast or dose level decreased. For a given dose level at 16 mGy, the MTF{sub 50%} value normalized to the B40 kernel decreased from 98.4% at 21 HU to 88.5% at 7 HU for I40-3 and from 97.6% to 82.1% for I40-5. At 21 HU, the relative MTF{sub 50%} value decreased from 98.4% at 16 mGy to 90.7% at 4 mGy for I40-3 and from 97.6% to 85.6% for I40-5. Conclusions: A simple technique using ensemble averaging from repeated CT scans can be used to measure the spatial resolution of IR techniques in CT at very low contrast levels. The evaluated IR method degraded the spatial resolution at low contrast and high noise levels.

  9. Epstein-Barr Virus-Associated Lymphoepithelioma-Like Gastric Carcinoma Presenting as a Submucosal Mass: CT Findings with Pathologic Correlation

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Sang Won; Shin, Hyeong Cheol; Kim, Il Young; Kim, Chang Jin; Lee, Ji Hye; Lee, Chang Kyun; Jeong, Dong Jun [Soonchunhyang University Cheonan Hospital, Cheonan(Korea, Republic of)

    2010-12-15

    A lymphoepithelioma-like carcinoma, characterized by a carcinoma with heavy lymphocyte infiltration, is one of the histological patterns observed in patients with Epstein-Barr virus (EBV)-associated gastric carcinoma. Less than half of invasive carcinomas with lymphoepithelioma-like histology can grow to make a submucosal mass. These tumors generally have a better prognosis than conventional adenocarcinomas. We report a case of an EBV-associated lymphoepitheliomalike gastric carcinoma that presented as a submucosal mass on multi-detector (MD) CT and correlate them with the pathology

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

    Directory of Open Access Journals (Sweden)

    Christopher T. Sikwila

    2014-05-01

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

  11. Patient-specific dose calculations for pediatric CT of the chest, abdomen and pelvis

    Energy Technology Data Exchange (ETDEWEB)

    Kost, Susan D.; Carver, Diana E.; Stabin, Michael G. [Vanderbilt University, Physics and Astronomy Department, Nashville, TN (United States); Vanderbilt University Medical Center, Department of Radiology and Radiological Sciences, Nashville, TN (United States); Fraser, Nicholas D.; Pickens, David R.; Price, Ronald R.; Hernanz-Schulman, Marta [Vanderbilt University Medical Center, Department of Radiology and Radiological Sciences, Nashville, TN (United States)

    2015-11-15

    Organ dose is essential for accurate estimates of patient dose from CT. To determine organ doses from a broad range of pediatric patients undergoing diagnostic chest-abdomen-pelvis CT and investigate how these relate to patient size. We used a previously validated Monte Carlo simulation model of a Philips Brilliance 64 multi-detector CT scanner (Philips Healthcare, Best, The Netherlands) to calculate organ doses for 40 pediatric patients (M:F = 21:19; range 0.6-17 years). Organ volumes and positions were determined from the images using standard segmentation techniques. Non-linear regression was performed to determine the relationship between volume CT dose index (CTDI{sub vol})-normalized organ doses and abdominopelvic diameter. We then compared results with values obtained from independent studies. We found that CTDI{sub vol}-normalized organ dose correlated strongly with exponentially decreasing abdominopelvic diameter (R{sup 2} > 0.8 for most organs). A similar relationship was determined for effective dose when normalized by dose-length product (R{sup 2} = 0.95). Our results agreed with previous studies within 12% using similar scan parameters (e.g., bowtie filter size, beam collimation); however results varied up to 25% when compared to studies using different bowtie filters. Our study determined that organ doses can be estimated from measurements of patient size, namely body diameter, and CTDI{sub vol} prior to CT examination. This information provides an improved method for patient dose estimation. (orig.)

  12. National Survey of Radiation Dose and Image Quality in Adult CT Head Scans in Taiwan.

    Directory of Open Access Journals (Sweden)

    Chung-Jung Lin

    Full Text Available The purpose of the present study was to evaluate the influence of different variables on radiation dose and image quality based on a national database.Taiwan's Ministry of Health and Welfare requested all radiology departments to complete a questionnaire for each of their CT scanners. Information gathered included all scanning parameters for CT head scans. For the present analysis, CT machines were divided into three subgroups: single slice CT (Group A; multi-detector CT (MDCT with 2-64 slices (Group B; and MDCT with more than 64 slices (Group C. Correlations between computed tomography dose index (CTDI and signal-to-noise ratio (SNR with cumulated tube rotation number (CTW(n and cumulated tube rotation time (CTW(s, and sub group analyses of CTDI and SNR across the three groups were performed.CTDI values demonstrated a weak correlation (r = 0.33 with CTW(n in Group A. SNR values demonstrated a weak negative correlation (r = -0.46 with CTW(n in Group C. MDCT with higher slice numbers used more tube potential resulting in higher effective doses. There were both significantly lower CTDI and SNR values in helical mode than in axial mode in Group B, but not Group C.CTW(n and CTW(s did not influence radiation output. Helical mode is more often used in MDCT and results in both lower CTDI and SNR compared to axial mode in MDCT with less than 64 slices.

  13. 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.)

  14. Optimizing CT for the evaluation of vestibular aqueduct enlargement:Inter-rater reproducibility and predictive value of reformatted CT measurements

    Institute of Scientific and Technical Information of China (English)

    Misun Hwang; Ryan Marovich; Samuel S. Shin; David Chi; Barton F. Branstetter IV

    2015-01-01

    Enlarged vestibular aqueduct (EVA), the most frequent identifiable cause of congenital hearing loss, is evaluated with high-definition multi-detector CT in the axial plane. Our purpose was to determine which reformatted CT measurements are most reproducible. Seven multiplanar reformatted images were created for each of the 64 temporal bones in patients with EVA. Intraclass correlation coefficients (ICC) were used to assess inter-observer variability, and both linear regression and ROC analyses were used to compare the measurements with severity of hearing loss, as assessed by pure tone audiometry. All seven measurements had excellent inter-observer variability, with average-measure ICC ranging from 0.92 to 0.98. There was no statistically significant correlation between the radiologic degree of aqueduct enlargement and severity of hearing loss using any of the seven measurements;ROC analyses revealed areas under the curves ranging from 0.57 to 0.73. Optimal accuracy was obtained with a threshold of 1.75 mm as measured at the aqueductal aperture in the P€oschl plane, with sensitivity of 0.75 and specificity of 0.63. Although the radiologic measurement may not serve as a reliable tool for assessing severity of EVA, P€oschl plane reformatting has proven to be better than conventional axial acquisition plane for identifying patients with clinically significant hearing loss.

  15. 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 ...

  16. 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 ...

  17. Evaluation of CT Angiography in the Diagnosis of Renal Artery Fiber Muscular Dysplasia%肾动脉纤维肌性发育不良的CTA诊断价值

    Institute of Scientific and Technical Information of China (English)

    曹茂盛; 黄卫华; 陈爱华; 尚斌

    2014-01-01

    Objective To evaluate multi-slice spiral CT angiography (MSCTA) in diagnosing renal artery fibromuscular dysplasia (RAFMD).Methods A total of 16 patients with surgically-or DSA-proved RAFMD were enrolled in this study.All patients received 64-row 128-slice spiral CT angiography.The clinical data and imaging manifestations,focusing on the lesion' s location,degree of stenosis and secondary changes,were retrospectively analyzed.Results Of the 16 cases,RAFMD occurred in the right renal artery in 8,in the left renal artery in4,and in the bilateral renal arteries in 4.In 14 cases the lesion was located at the middle-distal segment of renal artery,and in two cases the lesion was located at the proximal segment of renal artery.In 12 cases,the middle-distal segment of renal artery took the form of string-of-beads,with the diameter of bead being larger than the normal arterial lurnen in 10 and less than the normal arteriallumen in 2.Long segment smooth stenosis of the renal artery lumen was seen in 2 cases,and localized concentric stenosis was observed in other two cases.RAFMD associated with aneurysm formation was found in 8 cases and with arterial dissection in one case.Renal infarction caused by RAFMD was observed in one case.RAFMD complicated by superior mesenteric artery fibromuscular dysplasia was seen in 2 cases.Conclusion The 64-row 128-slice spiral CT angiography can distinctly display the various pathological changes of renal artery fibromuscular dysplasia.Therefore,CT angiography should be the imaging examination of first choice for the diagnosis of RAFMD.%目的 探讨多层螺旋CT血管成像(MSCTA)对肾动脉纤维肌性发育不良(RAFMD)的诊断价值.方法 回顾性研究经手术或数字减影血管造影(DSA)确认的RAFMD 16例CTA表现并分析其病变部位、狭窄程度及继发改变等.结果 16例RAFMD中单独发生于右肾动脉8例,单独发生于左肾动脉4例,双侧肾动脉均发生4例.14例发生于肾动脉中远段,2例发生

  18. Detection of Small Hepatocellular Carcinoma with Multi- detector Row CT:Effect of Iodine Concentration of Contrast Material%多排螺旋CT增强扫描对比剂浓度对小肝癌检出率的影响

    Institute of Scientific and Technical Information of China (English)

    田洪梓

    2012-01-01

      目的:通过多排螺旋CT动脉期及门脉期增强扫描,以评估对比剂浓度对小肝癌(≤3cm)检出率的影响.方法:95例肝癌患者随机分为2组行多排螺旋CT肝脏平扫及动脉期、门脉期增强扫描,其中1组(48例)注射碘帕醇370mg I/ml(1.5ml/kg),另外1组(47例)注射碘帕醇300mg I/ml(1.85ml/kg),均于30秒注射完毕.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2组≤3cm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101个≤3cm.对于≤3cm的病灶动脉期370mg I/ml组诊断敏感性高于300mg I/ml组,差别有统计学意义;在门脉期2组病人的诊断敏感性无显著性差异.结论:高浓密度对比剂在动脉期可提高小肝癌(≤3cm)的检出率.%  Objective:To evaluate the effect of iodine concentration of contrast material on detection of small hepatocellular carcinoma (SHCC) with multi-detector row CT by using 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 arterial phase (AP) and hepatic parenchymal phase (HPP) scanning prospectively. Patients were randomized into two groups to receive Iopamidol 370 mg I/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 small tumors (≤3 cm) and iodine concentration groups were calculated and analyzed.Results:A total of 259 lesions were detected with 101 ≤3 cm in size. For AP, the sensitivity of Iopamidol 370 mg I/ml group was significantly higher than Iopamidol 300 mg I/ml. For HPP, there were no significant differences between groups. Conclusions:High iodine concentration contrast material

  19. Dynamic CT myocardial perfusion imaging: detection of ischemia in a porcine model with FFR verification

    Science.gov (United States)

    Fahmi, Rachid; Eck, Brendan L.; Vembar, Mani; Bezerra, Hiram G.; Wilson, David L.

    2014-03-01

    Dynamic cardiac CT perfusion (CTP) is a high resolution, non-invasive technique for assessing myocardial blood ow (MBF), which in concert with coronary CT angiography enable CT to provide a unique, comprehensive, fast analysis of both coronary anatomy and functional ow. We assessed perfusion in a porcine model with and without coronary occlusion. To induce occlusion, each animal underwent left anterior descending (LAD) stent implantation and angioplasty balloon insertion. Normal ow condition was obtained with balloon completely de ated. Partial occlusion was induced by balloon in ation against the stent with FFR used to assess the extent of occlusion. Prospective ECG-triggered partial scan images were acquired at end systole (45% R-R) using a multi-detector CT (MDCT) scanner. Images were reconstructed using FBP and a hybrid iterative reconstruction (iDose4, Philips Healthcare). Processing included: beam hardening (BH) correction, registration of image volumes using 3D cubic B-spline normalized mutual-information, and spatio-temporal bilateral ltering to reduce partial scan artifacts and noise variation. Absolute blood ow was calculated with a deconvolutionbased approach using singular value decomposition (SVD). Arterial input function was estimated from the left ventricle (LV) cavity. Regions of interest (ROIs) were identi ed in healthy and ischemic myocardium and compared in normal and occluded conditions. Under-perfusion was detected in the correct LAD territory and ow reduction agreed well with FFR measurements. Flow was reduced, on average, in LAD territories by 54%.

  20. Diagnostic Value of 64 Multi-detector Spiral CT Angiography on Myocardial Bridge and Mural Coronary Artery%64排螺旋CT对冠状动脉心肌桥的诊断价值

    Institute of Scientific and Technical Information of China (English)

    孙新峰; 张俊; 骆宾; 关文华

    2014-01-01

    Objective To investigate the diagnostic value of 64 MSCT angiography in determining Myocardial Bridge(MB) and Mural Coronary Artery (MCA). Methods 416 patients were performed with ECG-gated CCTA by 64 MSCT scanner. The presence of MB and the deepth, lenghth and diametre of intramural coronary artery in CCTA images were evaluated and recorded. Results The detection rate of MB was 20.4% (85/416). The detection rate of MB was 24.5% (63/257) in male patients and 13.8% (22/159) in female patients. The detection rate of MB by CCTA was 20.4%in this study. The most common location of MB was in the LAD, and 83.7% of the intramural coronary artery are located in the shalow part. Atherosclerotic plaques were found in 6.7% of MB cases. Conclusion Myocardial bridge detection rate of CCTA was significantly higher than that of conventional coronary angiography. And the study does not prove any relationship between myocardial bridge and cardiovascular events.%目的:探讨64排螺旋CT冠状动脉成像(CCTA)对壁冠状动脉-心肌桥的诊断价值。方法共416例CCTA纳入本研究,观察有无心肌桥的发生,并测量壁冠状动脉的深度、长度、直径。结果85例病人发现有心肌桥,CCTA心肌桥发现率为20.4%(85/416)。冠状动脉心肌桥平均发病年龄为56.3±14.2岁。男性发病率为24.5%(63/257),女性为13.8%(22/159)。发生率最高的血管为前降支(LAD),并且87.3%的壁冠状动脉位置浅表,6.7%的桥血管伴有动脉粥样硬化斑块。结论心肌桥的CCTA检出率明显高于传统冠状动脉造影,本次研究没有证明心肌桥与心血管事件存在相互关系。

  1. MDCT定量评价腔内血栓形成的腹主动脉瘤瘤体弹性%Quantitative Assessment of Abdominal Aortic Aneurysm Sac Distensibility with Intraluminal Thrombus Using Multi-Detector CT

    Institute of Scientific and Technical Information of China (English)

    李莉丽; 查云飞; 李亮; 彭宙峰; 陆雪松

    2013-01-01

    Objective To noninvasively and quantitatively evaluate the distensibility of abdominal aortic aneurysm sac(AAAs) with intraluminal thrombus using 64 MDCT.Methods 31 patients with AAAs underwent computed tomography angiography (CTA)examination.Time resolved images were acquired with the retrospective ECG-gated technology and section data acquisition mode.Scan data were reconstructed at 20 phases between 0% and 95% of the R-R intervals with an increment of 5%.All reconstructed images were analyzed using algorithm developed Matlab 7.5 (Version R2007b,the MathWorks,Natick,MA,USA).At different phases,AAA sac diameter,max and minimal area,distensibility values were calculated in the lumen and wall.Results Aneurysm sac diameter had not any correlation with distensibility(rwall =-0.315,rlumen =-0.251,Pwall,lumen > 0.05).Mean distensibility of Dlumen and Dwall were (1.15 ± 0.47) ×10-5Pa-1 and (0.95 ± 0.48) × 10-5 pa-1,respectively.A significant difference of distensibility between AAA wall and AAA lumen was proved (P < 0.05) also by use of the Wilcoxon test.Distensibility of the AAA wall was significantly lower than that of AAA lumen.Conclusion AAA distensibility is completely independent of the aneurysm size,and the distensibility of lumen is significantly higher than that of wall.Distensibility assessment could be a valuble method for the diagnosis and treatment for abdominal aortic aneurysm.%目的 探讨64排CT定量评价腔内血栓腹主动脉瘤瘤体弹性.方法 对31例含腔内血栓腹主动脉瘤患者采用回顾性心电门控技术和分段数据采集方式行腹主动脉64排螺旋CT血管成像.将获得的原始数据在0%~ 95% R-R间期,间隔5%分别重组图像,采用MATLAB 7.5软件行半自动图像分割方法,然后分别测量各期相内瘤体直径、最大和最小面积及弹性D值等指标在管腔及管壁方面的变化.结果 腹主动脉瘤瘤体最大直径与管壁、管腔弹性值间均无显著相关性(r分别为-0.315、-0.251,P均>0.05).瘤体管腔弹性D值为(1.15 ±0.47)×10-5Pa-1,管壁弹性D值为(0.95±0.48)×10-5Pa-1,瘤体管腔D值明显高于管壁,差异具有统计学意义(P<0.05).结论 腔内血栓形成的腹主动脉瘤瘤体弹性的大小并不依赖于瘤体直径的变化,且瘤体管腔的弹性要明显高于管壁.弹性评估可以为腹主动脉瘤的诊断和治疗提供帮助.

  2. MO-E-17A-06: Organ Dose in Abdomen-Pelvis CT: Does TG 111 Equilibrium Dose Concept Better Accounts for KVp Dependence Than Conventional CTDI?

    Energy Technology Data Exchange (ETDEWEB)

    Li, X [Cleveland State University, Cleveland, OH (United States); Morgan, A; Davros, W [Cleveland State University, Cleveland, OH (United States); Cleveland Clinic, Cleveland, Ohio (United States); Dong, F [Cleveland Clinic, Cleveland, Ohio (United States); Primak, A [Siemens Medical Solutions USA, Inc. (United States); Segars, W [Duke University, Durham, NC (United States)

    2014-06-15

    Purpose: In CT imaging, a desirable quality assurance (QA) dose quantity should account for the dose variability across scan parameters and scanner models. Recently, AAPM TG 111 proposed to use equilibrium dose-pitch product, in place of CT dose index (CTDI100), for scan modes involving table translation. The purpose of this work is to investigate whether this new concept better accounts for the kVp dependence of organ dose than the conventional CTDI concept. Methods: The adult reference female extended cardiac-torso (XCAT) phantom was used for this study. A Monte Carlo program developed and validated for a 128-slice CT system (Definition Flash, Siemens Healthcare) was used to simulate organ dose for abdomenpelvis scans at five tube voltages (70, 80, 100, 120, 140 kVp) with a pitch of 0.8 and a detector configuration of 2x64x0.6 mm. The same Monte Carlo program was used to simulate CTDI100 and equilibrium dose-pitch product. For both metrics, the central and peripheral values were used together with helical pitch to calculate a volume-weighted average, i.e., CTDIvol and (Deq)vol, respectively. Results: While other scan parameters were kept constant, organ dose depended strongly on kVp; the coefficient of variation (COV) across the five kVp values ranged between 70–75% for liver, spleen, stomach, pancreas, kidneys, colon, small intestine, bladder, and ovaries, all of which were inside the primary radiation beam. One-way analysis of variance (ANOVA) for the effect of kVp was highly significant (p=3e−30). When organ dose was normalized by CTDIvol, the COV across the five kVp values reduced to 7–16%. The effect of kVp was still highly significant (p=4e−4). When organ dose was normalized by (Deq)vol, the COV further reduced to 4−12%. The effect of kVp was borderline significant (p=0.04). Conclusion: In abdomen-pelvis CT, TG 111 equilibrium dose concept better accounts for kVp dependence than the conventional CTDI. This work is supported by a faculty startup

  3. MO-E-17A-06: Organ Dose in Abdomen-Pelvis CT: Does TG 111 Equilibrium Dose Concept Better Accounts for KVp Dependence Than Conventional CTDI?

    International Nuclear Information System (INIS)

    Purpose: In CT imaging, a desirable quality assurance (QA) dose quantity should account for the dose variability across scan parameters and scanner models. Recently, AAPM TG 111 proposed to use equilibrium dose-pitch product, in place of CT dose index (CTDI100), for scan modes involving table translation. The purpose of this work is to investigate whether this new concept better accounts for the kVp dependence of organ dose than the conventional CTDI concept. Methods: The adult reference female extended cardiac-torso (XCAT) phantom was used for this study. A Monte Carlo program developed and validated for a 128-slice CT system (Definition Flash, Siemens Healthcare) was used to simulate organ dose for abdomenpelvis scans at five tube voltages (70, 80, 100, 120, 140 kVp) with a pitch of 0.8 and a detector configuration of 2x64x0.6 mm. The same Monte Carlo program was used to simulate CTDI100 and equilibrium dose-pitch product. For both metrics, the central and peripheral values were used together with helical pitch to calculate a volume-weighted average, i.e., CTDIvol and (Deq)vol, respectively. Results: While other scan parameters were kept constant, organ dose depended strongly on kVp; the coefficient of variation (COV) across the five kVp values ranged between 70–75% for liver, spleen, stomach, pancreas, kidneys, colon, small intestine, bladder, and ovaries, all of which were inside the primary radiation beam. One-way analysis of variance (ANOVA) for the effect of kVp was highly significant (p=3e−30). When organ dose was normalized by CTDIvol, the COV across the five kVp values reduced to 7–16%. The effect of kVp was still highly significant (p=4e−4). When organ dose was normalized by (Deq)vol, the COV further reduced to 4−12%. The effect of kVp was borderline significant (p=0.04). Conclusion: In abdomen-pelvis CT, TG 111 equilibrium dose concept better accounts for kVp dependence than the conventional CTDI. This work is supported by a faculty startup

  4. 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 ...

  5. Assessment of image quality in soft tissue and bone visualization tasks for a dedicated extremity cone-beam CT system

    Energy Technology Data Exchange (ETDEWEB)

    Demehri, S. [Johns Hopkins University, The Russell H. Morgan Department of Radiology and Radiological Science, Baltimore, MD (United States); Johns Hopkins Outpatient Center, JHOC 5168, Musculoskeletal Radiology, Baltimore, MD (United States); Muhit, A.; Zbijewski, W.; Stayman, J.W. [Johns Hopkins University, Department of Biomedical Engineering, Baltimore, MD (United States); Yorkston, J.; Packard, N.; Senn, R.; Yang, D.; Foos, D. [Carestream Health, Rochester, NY (United States); Thawait, G.K.; Fayad, L.M.; Chhabra, A.; Carrino, J.A. [Johns Hopkins University, The Russell H. Morgan Department of Radiology and Radiological Science, Baltimore, MD (United States); Siewerdsen, J.H. [Johns Hopkins University, The Russell H. Morgan Department of Radiology and Radiological Science, Baltimore, MD (United States); Johns Hopkins University, Department of Biomedical Engineering, Baltimore, MD (United States)

    2015-06-01

    To assess visualization tasks using cone-beam CT (CBCT) compared to multi-detector CT (MDCT) for musculoskeletal extremity imaging. Ten cadaveric hands and ten knees were examined using a dedicated CBCT prototype and a clinical multi-detector CT using nominal protocols (80kVp-108mAs for CBCT; 120kVp- 300mAs for MDCT). Soft tissue and bone visualization tasks were assessed by four radiologists using five-point satisfaction (for CBCT and MDCT individually) and five-point preference (side-by-side CBCT versus MDCT image quality comparison) rating tests. Ratings were analyzed using Kruskal-Wallis and Wilcoxon signed-rank tests, and observer agreement was assessed using the Kappa-statistic. Knee CBCT images were rated ''excellent'' or ''good'' (median scores 5 and 4) for ''bone'' and ''soft tissue'' visualization tasks. Hand CBCT images were rated ''excellent'' or ''adequate'' (median scores 5 and 3) for ''bone'' and ''soft tissue'' visualization tasks. Preference tests rated CBCT equivalent or superior to MDCT for bone visualization and favoured the MDCT for soft tissue visualization tasks. Intraobserver agreement for CBCT satisfaction tests was fair to almost perfect (κ ∝ 0.26-0.92), and interobserver agreement was fair to moderate (κ ∝ 0.27-0.54). CBCT provided excellent image quality for bone visualization and adequate image quality for soft tissue visualization tasks. (orig.)

  6. Comparison of Multidetector CT Angiographic Findings with Operative Findings of Renal Vasculature in Living Renal Donors

    Directory of Open Access Journals (Sweden)

    Soodeh Sagheb

    2010-05-01

    Full Text Available Background/Objective: In kidney transplantation, decision about donation of the proper kidney is not the same between different surgeons. One of the most important factors for choosing the best kidney for transplantation is a simple vasculature anatomy and a kidney without abnormalities. In laparoscopic nephrectomy, the left kidney is preferred, because it has a longer renal vein and the renal artery is not behind the inferior vena cava (IVC. In other situations, in order to reduce the vascular morbidity of the surgery, nephrectomy is on the side which has a simpler vascular anatomy."nAssessment of renal vasculature of a live donor with noninvasive techniques is a necessity for live donors. For delineation of vascular anomalies of the kidney as well as urinary system abnormalities, Multi-Detector CT seems to be an excellent method for evaluation."nPatients and Methods: In this study, 59 live donors were assessed with multi-detector CT angiography. After injection of 80 ml contrast media, we acquired CT images with 0.6 mm slice thickness. Finally, processing and three dimensional reconstructions were performed and the accessory arteries, early branching of the main renal artery, the number of main renal vessels and the ureters were assessed. Findings were compared with the nephrectomy results."nResults: In multi slice CT angiography the prevalence of accessory renal artery was 3.4% with 98% accuracy, early branching of the main renal artery was 8.4% with 100% accuracy. Multiplicity of renal veins was seen in 8.4% of donors with 98% accuracy. Duplicated ureter was not seen in any of the donors."nDiscussion: The accuracy of CT angiography is 95% for depicting accessory renal artery and multiple renal artery and 100% for early branching. These results were comparable with the findings in conventional angiography and the studies showed that this method is more valuable in comparison with MR angiography and digital subtraction angiography. Also, it is

  7. 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.)

  8. Ultra-high resolution flat-panel volume CT: fundamental principles, design architecture, and system characterization

    Energy Technology Data Exchange (ETDEWEB)

    Gupta, Rajiv; Brady, Tom [Massachusetts General Hospital, Department of Radiology, Founders House, FND-2-216, Boston, MA (United States); Grasruck, Michael; Suess, Christoph; Schmidt, Bernhard; Stierstorfer, Karl; Popescu, Stefan; Flohr, Thomas [Siemens Medical Solutions, Forchheim (Germany); Bartling, Soenke H. [Hannover Medical School, Department of Neuroradiology, Hannover (Germany)

    2006-06-15

    Digital flat-panel-based volume CT (VCT) represents a unique design capable of ultra-high spatial resolution, direct volumetric imaging, and dynamic CT scanning. This innovation, when fully developed, has the promise of opening a unique window on human anatomy and physiology. For example, the volumetric coverage offered by this technology enables us to observe the perfusion of an entire organ, such as the brain, liver, or kidney, tomographically (e.g., after a transplant or ischemic event). By virtue of its higher resolution, one can directly visualize the trabecular structure of bone. This paper describes the basic design architecture of VCT. Three key technical challenges, viz., scatter correction, dynamic range extension, and temporal resolution improvement, must be addressed for successful implementation of a VCT scanner. How these issues are solved in a VCT prototype and the modifications necessary to enable ultra-high resolution volumetric scanning are described. The fundamental principles of scatter correction and dose reduction are illustrated with the help of an actual prototype. The image quality metrics of this prototype are characterized and compared with a multi-detector CT (MDCT). (orig.)

  9. Morphometrical dimensions of the sheep thoracolumbar vertebrae as seen on digitised CT images.

    Science.gov (United States)

    Mageed, Mahmoud; Berner, Dagmar; Jülke, Henriette; Hohaus, Christian; Brehm, Walter; Gerlach, Kerstin

    2013-09-01

    The sheep spine is widely used as a model for preclinical research in human medicine to test new spinal implants and surgical procedures. Therefore, precise morphometric data are needed. The present study aimed to provide computed tomographic (CT) morphometry of sheep thoracolumbar spine. Five adult normal Merino sheep were included in this study. Sheep were anaesthetised and positioned in sternal recumbency. Subsequently, transverse and sagittal images were obtained using a multi-detector-row helical CT scanner. Measurements of the vertebral bodies, pedicles, intervertebral disc and transverse processes were performed with dedicated software. Vertebral bodies and the spinal canal were wider than they were deep, most obviously in the lumbar vertebrae. The intervertebral discs were as much as 57.4% thicker in the lumbar than in the thoracic spine. The pedicles were higher and longer than they were wide over the entire thoracolumbar spine. In conclusion, the generated data can serve as a CT reference for the ovine thoracolumbar spine and may be helpful in using sheep spine as a model for human spinal research.

  10. Automated characterization of normal and pathologic lung tissue by topological texture analysis of multidetector CT

    Science.gov (United States)

    Boehm, H. F.; Fink, C.; Becker, C.; Reiser, M.

    2007-03-01

    Reliable and accurate methods for objective quantitative assessment of parenchymal alterations in the lung are necessary for diagnosis, treatment and follow-up of pulmonary diseases. Two major types of alterations are pulmonary emphysema and fibrosis, emphysema being characterized by abnormal enlargement of the air spaces distal to the terminal, nonrespiratory bronchiole, accompanied by destructive changes of the alveolar walls. The main characteristic of fibrosis is coursening of the interstitial fibers and compaction of the pulmonary tissue. With the ability to display anatomy free from superimposing structures and greater visual clarity, Multi-Detector-CT has shown to be more sensitive than the chest radiograph in identifying alterations of lung parenchyma. In automated evaluation of pulmonary CT-scans, quantitative image processing techniques are applied for objective evaluation of the data. A number of methods have been proposed in the past, most of which utilize simple densitometric tissue features based on the mean X-ray attenuation coefficients expressed in terms of Hounsfield Units [HU]. Due to partial volume effects, most of the density-based methodologies tend to fail, namely in cases, where emphysema and fibrosis occur within narrow spatial limits. In this study, we propose a methodology based upon the topological assessment of graylevel distribution in the 3D image data of lung tissue which provides a way of improving quantitative CT evaluation. Results are compared to the more established density-based methods.

  11. 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 ...

  12. 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 ...

  13. 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- ...

  14. 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- ...

  15. 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 ...

  16. Computed Tomography (CT) -- Sinuses

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    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 ...

  17. Computed Tomography (CT) -- Head

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    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 ...

  18. Computed Tomography (CT) -- Sinuses

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    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 ...

  19. Computed Tomography (CT) -- Head

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    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 ...

  20. 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 ... See the Safety page for more information about pregnancy and x-rays. CT scanning is, in general, ...

  1. 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 ...

  2. Computed Tomography (CT) -- Head

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    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, ...

  3. Computed Tomography (CT) -- Sinuses

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    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, ...

  4. Computed Tomography (CT) -- Head

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    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 ...

  5. 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 ...

  6. Are contrast media required for (68)Ga-DOTATOC PET/CT in patients with neuroendocrine tumours of the abdomen?

    Energy Technology Data Exchange (ETDEWEB)

    Mayerhoefer, Marius E.; Magnaldi, Silvia; Weber, Michael; Trattnig, Siegfried [Medical University of Vienna, Vienna General Hospital, Department of Radiology, PET/CT Center, Vienna (Austria); Schuetz, Matthias; Karanikas, Georgios [Medical University of Vienna, Vienna General Hospital, Department of Nuclear Medicine, PET/CT Center, Vienna (Austria)

    2012-04-15

    To determine the value of intravenous contrast medium in (68)Ga-DOTA-Phe(1)-Tyr(3)-octreotide - (68)Ga-DOTATOC - PET/CT for the detection of abdominal neuroendocrine tumours (NET). In fifty-five patients with known or suspected NETs of the abdomen PET/CT was performed on a 64-row multi-detector hybrid system. For PET, 150 MBq of (68)Ga-DOTATOC were injected intravenously. Full-dose unenhanced, and arterial- and venous-phase contrast-enhanced CT images were obtained. Unenhanced and contrast-enhanced PET/CT images were evaluated separately for the presence of NETs on a per-region basis, by two separate teams with different experience levels. On unenhanced PET/CT, sensitivity and specificity ranged from 89.3% (junior team) to 92% (senior team), and 99.1% (junior team) to 99.2% (senior team), respectively. On contrast-enhanced PET/CT, sensitivity and specificity ranged from 92.3% (junior team) to 98.5% (senior team), and 99.4% (junior team) to 99.5% (senior team), respectively. These increases in sensitivity and specificity, due to the use of contrast-enhanced images, were statistically significant (P < 0.05). Intravenous contrast medium only moderately, aleit significantly, improves the sensitivity of (68)Ga-DOTATOC PET/CT for the detection of abdominal NETs, and hardly affects specificity. Thus, while contrast enhancement is justified to achieve maximum sensitivity, unenhanced images may be sufficient for routine PET/CT in NET patients. (orig.)

  7. 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

  8. 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 ...

  9. 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 ...

  10. 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 ...

  11. Evaluation on the feasibility of assessment of volume perfusion for the whole lung by multi-slice spiral CT%应用多层螺旋CT对全肺容积灌注评价的可行性研究

    Institute of Scientific and Technical Information of China (English)

    孙海涛; 朱小飞; 张霞; 谢元忠; 柳澄

    2015-01-01

    Objective The aim of this study was to evaluate the feasibility of dynamic volume perfusion CT (VPCT) of the whole lung using a 128-slice CT for the quantitative assessment and visualization of pulmonary perfusion.Methods Imaging was performed in a control group of 17 subjects who had no signs of disturbance of pulmonary function or diffuse lung disease, and 15 patients (5 patients with acute pulmonary embolism and 10 with emphysema) who constituted the abnormal lung group. Dynamic VPCT was performed in all subjects, with calculation of pulmonary blood flow (PBF), pulmonary blood volume (PBV), and mean transit time (MTT) generated from dynamic contrast images with a coverage of 20.7 cm. Regional and volumetric PBF, PBV, and MTT were statistically evaluated and compared made between the normal and abnormal lung groups, not with standing a few lungs in big size beyond the coverage of 20.7 cm.Results Regional PBF, PBV, and MTT demonstrated significant differences in the gravitational and was ogravitational directions in the normal lung group (P20.7 cm的覆盖范围,但是在肺实质正常组和肺实质异常组间动态容积灌注CT的PBF和PBV均存在统计学差异(P<0.05).结论 应用128层螺旋CT定量及可视化定性评价全肺动态容积灌注具有可行性,对于全肺的形态和功能学特征仅用一种检查就能进行全面评价.

  12. Whole spine CT for evaluation of scoliosis in children - Feasibility of sub-milli Sievert scanning protocol

    Energy Technology Data Exchange (ETDEWEB)

    Kalra, Mannudeep K. [Center for Medical Image Science and Visualization (CMIV), Linkoeping Univ., Linkoeping Univ. Hospital, Linkoeping (Sweden); Massachusetts General Hospital Imaging, Massachusetts General Hospital, Boston (United States); Quick, Petter; Persson, Anders [Center for Medical Image Science and Visualization (CMIV), Linkoeping Univ., Linkoeping Univ. Hospital, Linkoeping (Sweden)], e-mail: anders.persson@cmiv.liu.se; Singh, Sarabjeet [Massachusetts General Hospital Imaging, Massachusetts General Hospital, Boston (United States); Sandborg, Michael [Center for Medical Image Science and Visualization (CMIV), Linkoeping Univ., Linkoeping Univ. Hospital, Linkoeping (Sweden); Department of Radiophysics, Linkoeping Univ. Hospital, Linkoeping (Sweden)

    2013-03-15

    Background: Optimization of CT radiation dose is important for children due to their higher risk of radiation-induced adverse effects. Anatomical structures with high inherent contrast, such as bones can be imaged at very low radiation doses by optimizing scan parameters. Purpose: To assess feasibility of sub-milli Sievert whole spine CT scanning protocol for evaluation of scoliosis in children. Material and Methods: With approval of the ethical board, we performed whole spine CT for evaluation of scoliosis in 22 children (age range, 3-18 years; mean age, 13 years; 13 girls, 9 boys) on a 128-slice dual source multidetector-row CT scanner. Lowest possible quality reference mAs value (image quality factor for xy-z automatic exposure control or xyz-AEC, CARE Dose 4D) was selected on a per patient basis. Remaining parameters were held constant at 3.0:1 pitch, 128 X 0.6 mm detector collimation, 115.2 mm table feed per gantry rotation, 100 kVp, and 1 and 3 mm reconstructed sections. Average mAs, projected estimated dose savings with AEC, computed tomography dose index volume (CTDI vol), and dose length product (DLP) were recorded. Artifacts were graded on a four-point scale (1, no artifacts; 4, severe artifacts). Ability to identify vertebral and pedicular contours, and measure pedicular width and degree of vertebral rotation was graded on a three-point scale (1, unacceptable; 3, excellent). Results: All CT examinations were deemed as reliable for identifying vertebral and pedicular contours as well as for measuring pedicular width (5.9 {+-} 1.6 mm) and degree of vertebral rotation (28.7{+-} 23.4 deg). Mean objective image noise and signal to noise ratio (SNR) were 57.5 {+-} 21.5 {+-} 4.7 2.3, respectively. With a mean quality reference mAs of 13, the scanner employed an average actual effective mAs of 10 {+-} 3.8 (range, 6-18 mAs) with an estimated radiation dose saving of 43.5 {+-} 16.3% with xyz-AEC compared with fixed mAs. The mean CTDI, DLP, and estimated effective

  13. 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.

  14. Endobronchial valves in severe emphysematous patients: CT evaluation of lung fissures completeness, treatment radiological response and quantitative emphysema analysis

    Energy Technology Data Exchange (ETDEWEB)

    Koenigkam-Santos, Marcel, E-mail: marcelk46@yahoo.com.br, E-mail: marcelk46@usp.b [Universidade de Sao Paulo (HCFMRP/USP), Ribeirao Preto, SP (Brazil). Hospital das Clinicas da Faculdade de Medicina; Paula, Wagner Diniz de [University of Brasilia (UnB), DF (Brazil). Brasilia University Hospital; Gompelmann, Daniela [University of Heidelberg (Germany). Department of Pneumology and Respiratory Medicine of the Chest Clinic (Thoraxklinik); Kauczor, Hans-Ulrich [University of Heidelberg (Germany). Department of Diagnostic and Interventional Radiology; Heussel, Claus Peter; Puderbach, Michael [University of Heidelberg (Germany). Department of Diagnostic and Interventional Radiology with Nuclear Medicine of the Chest Clinic (Thoraxklinik)

    2013-01-15

    Objective: To evaluate lung fissures completeness, post-treatment radiological response and quantitative CT analysis (QCTA) in a population of severe emphysematous patients submitted to endobronchial valves (EBV) implantation. Materials and Methods: Multi-detectors CT exams of 29 patients were studied, using thin-section low dose protocol without contrast. Two radiologists retrospectively reviewed all images in consensus; fissures completeness was estimated in 5% increments and post-EBV radiological response (target lobe atelectasis/volume loss) was evaluated. QCTA was performed in pre and post-treatment scans using a fully automated software. Results: CT response was present in 16/29 patients. In the negative CT response group, all 13 patients presented incomplete fissures, and mean oblique fissures completeness was 72.8%, against 88.3% in the other group. QCTA most significant results showed a reduced post-treatment total lung volume (LV) (mean 542 ml), reduced EBV-submitted LV (700 ml) and reduced emphysema volume (331.4 ml) in the positive response group, which also showed improved functional tests. Conclusion: EBV benefit is most likely in patients who have complete interlobar fissures and develop lobar atelectasis. In patients with no radiological response we observed a higher prevalence of incomplete fissures and a greater degree of incompleteness. The fully automated QCTA detected the post-treatment alterations, especially in the treated lung analysis. (author)

  15. Endobronchial valves in severe emphysematous patients: CT evaluation of lung fissures completeness, treatment radiological response and quantitative emphysema analysis

    Directory of Open Access Journals (Sweden)

    Marcel Koenigkam-Santos

    2013-02-01

    Full Text Available OBJECTIVE: To evaluate lung fissures completeness, post-treatment radiological response and quantitative CT analysis (QCTA in a population of severe emphysematous patients submitted to endobronchial valves (EBV implantation. MATERIALS AND METHODS: Multi-detectors CT exams of 29 patients were studied, using thin-section low dose protocol without contrast. Two radiologists retrospectively reviewed all images in consensus; fissures completeness was estimated in 5% increments and post-EBV radiological response (target lobe atelectasis/volume loss was evaluated. QCTA was performed in pre and post-treatment scans using a fully automated software. RESULTS: CT response was present in 16/29 patients. In the negative CT response group, all 13 patients presented incomplete fissures, and mean oblique fissures completeness was 72.8%, against 88.3% in the other group. QCTA most significant results showed a reduced post-treatment total lung volume (LV (mean 542 ml, reduced EBV-submitted LV (700 ml and reduced emphysema volume (331.4 ml in the positive response group, which also showed improved functional tests. CONCLUSION: EBV benefit is most likely in patients who have complete interlobar fissures and develop lobar atelectasis. In patients with no radiological response we observed a higher prevalence of incomplete fissures and a greater degree of incompleteness. The fully automated QCTA detected the post-treatment alterations, especially in the treated lung analysis.

  16. Automated coronary CT angiography plaque-lumen segmentation

    Science.gov (United States)

    Cline, Harvey E.; Krishnan, Karthik; Napel, Sandy; Rubin, Geoffrey D.; Turner, Wesley D.; Avila, Ricardo S.

    2009-02-01

    We are investigating the feasibility of a computer-aided detection (CAD) system to assist radiologists in diagnosing coronary artery disease in ECG gated cardiac multi-detector CT scans having calcified plaque. Coronary artery stenosis analysis is challenging if calcified plaque or the iodinated blood pool hides viable lumen. The research described herein provides an improved presentation to the radiologist by removing obscuring calcified plaque and blood pool. The algorithm derives a Gaussian estimate of the point spread function (PSF) of the scanner responsible for plaque blooming by fitting measured CTA image profiles. An initial estimate of the extent of calcified plaque is obtained from the image evidence using a simple threshold. The Gaussian PSF estimate is then convolved with the initial plaque estimate to obtain an estimate of the extent of the blooming artifact and this plaque blooming image is subtracted from the CT image to obtain an image largely free of obscuring plaque. In a separate step, the obscuring blood pool is suppressed using morphological operations and adaptive region growing. After processing by our algorithm, we are able to project the segmented plaque-free lumen to form synthetic angiograms free from obstruction. We can also analyze the coronary arteries with vessel tracking and centerline extraction to produce cross sectional images for measuring lumen stenosis. As an additional aid to radiologists, we also produce plots of calcified plaque and lumen cross-sectional area along selected blood vessels. The method was validated using digital phantoms and actual patient data, including in one case, a validation against the results of a catheter angiogram.

  17. Patient-specific dose estimation for pediatric chest CT

    Energy Technology Data Exchange (ETDEWEB)

    Li Xiang; Samei, Ehsan; Segars, W. Paul; Sturgeon, Gregory M.; Colsher, James G.; Frush, Donald P. [Medical Physics Graduate Program, Duke University, Durham, North Carolina 27705 and Department of Radiology, Duke Advanced Imaging Laboratories, Duke University Medical Center, Durham, North Carolina 27705 (United States); Medical Physics Graduate Program, Duke University, Durham, North Carolina 27705 (United States); Department of Radiology, Duke Advanced Imaging Laboratories, Duke University Medical Center, Durham, North Carolina 27705 (United States); Department of Physics, Duke University, Durham, North Carolina 27710 (United States); and Department of Biomedical Engineering, Duke University, Durham, North Carolina 27708 (United States); Medical Physics Graduate Program, Duke University, Durham, North Carolina 27705 and Department of Radiology, Duke Advanced Imaging Laboratories, Duke University Medical Center, Durham, North Carolina 27705 (United States); Department of Radiology, Duke Advanced Imaging Laboratories, Duke University Medical Center, Durham, North Carolina 27705 (United States); Medical Physics Graduate Program, Duke University, Durham, North Carolina 27705 and Global Applied Science Laboratory, GE Healthcare, Waukesha, Wisconsin 53188 (United States); Medical Physics Graduate Program, Duke University, Durham, North Carolina 27705 and Department of Radiology, Division of Pediatric Radiology, Duke University Medical Center, Durham North Carolina 27710 (United States)

    2008-12-15

    Current methods for organ and effective dose estimations in pediatric CT are largely patient generic. Physical phantoms and computer models have only been developed for standard/limited patient sizes at discrete ages (e.g., 0, 1, 5, 10, 15 years old) and do not reflect the variability of patient anatomy and body habitus within the same size/age group. In this investigation, full-body computer models of seven pediatric patients in the same size/protocol group (weight: 11.9-18.2 kg) were created based on the patients' actual multi-detector array CT (MDCT) data. Organs and structures in the scan coverage were individually segmented. Other organs and structures were created by morphing existing adult models (developed from visible human data) to match the framework defined by the segmented organs, referencing the organ volume and anthropometry data in ICRP Publication 89. Organ and effective dose of these patients from a chest MDCT scan protocol (64 slice LightSpeed VCT scanner, 120 kVp, 70 or 75 mA, 0.4 s gantry rotation period, pitch of 1.375, 20 mm beam collimation, and small body scan field-of-view) was calculated using a Monte Carlo program previously developed and validated to simulate radiation transport in the same CT system. The seven patients had normalized effective dose of 3.7-5.3 mSv/100 mAs (coefficient of variation: 10.8%). Normalized lung dose and heart dose were 10.4-12.6 mGy/100 mAs and 11.2-13.3 mGy/100 mAs, respectively. Organ dose variations across the patients were generally small for large organs in the scan coverage (<7%), but large for small organs in the scan coverage (9%-18%) and for partially or indirectly exposed organs (11%-77%). Normalized effective dose correlated weakly with body weight (correlation coefficient: r=-0.80). Normalized lung dose and heart dose correlated strongly with mid-chest equivalent diameter (lung: r=-0.99, heart: r=-0.93); these strong correlation relationships can be used to estimate patient-specific organ

  18. The effect of CT scanner parameters and 3D volume rendering techniques on the accuracy of linear, angular, and volumetric measurements of the mandible

    Science.gov (United States)

    Whyms, B.J.; Vorperian, H.K.; Gentry, L.R.; Schimek, E.M.; Bersu, E.T.; Chung, M.K.

    2013-01-01

    Objectives This study investigates the effect of scanning parameters on the accuracy of measurements from three-dimensional multi-detector computed tomography (3D-CT) mandible renderings. A broader range of acceptable parameters can increase the availability of CT studies for retrospective analysis. Study Design Three human mandibles and a phantom object were scanned using 18 combinations of slice thickness, field of view, and reconstruction algorithm and three different threshold-based segmentations. Measurements of 3D-CT models and specimens were compared. Results Linear and angular measurements were accurate, irrespective of scanner parameters or rendering technique. Volume measurements were accurate with a slice thickness of 1.25 mm, but not 2.5 mm. Surface area measurements were consistently inflated. Conclusions Linear, angular and volumetric measurements of mandible 3D-CT models can be confidently obtained from a range of parameters and rendering techniques. Slice thickness is the primary factor affecting volume measurements. These findings should also apply to 3D rendering using cone-beam-CT. PMID:23601224

  19. 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 ...

  20. The measurement of position of retromandibular vein with multi-detector row helical CTA in relation to the mandibular angle plasty.%下颌角手术相关颌后静脉走行的CTA研究

    Institute of Scientific and Technical Information of China (English)

    王燕; 华泽权; 刘文元; 李树华

    2012-01-01

    目的:应用CTA(血管造影术)影像测量颌后静脉与下颌角手术相关解剖,为避免手术中损伤颌后静脉提供指导.方法:选择30名正常成人下颌角及周围血管CTA扫描图像,应用ADW4.2图像处理软件测量颌后静脉距下颌角处颌骨各边缘的三维解剖位置.结果:颌后静脉距下颌角点的距离为(11.26±2.34) mm;在下颌角点上10 mm处距下颌骨后缘为(8.18±2.12) mm;在下颌角点上20 mm处距下颌骨后缘为(6.38±2.12) mm;在下颌角点上30 mm处距下颌骨后缘为(3.18±2.12) mm,在下颌角点上40 mm处距下颌骨后缘为(2.18±1.16) mm.结论:在下颌骨后缘手术时位置越高颌后静脉距下颌骨越近,手术越容易损伤颌后静脉;参照测量获得的解剖数据在下颌角成型手术中能避免损伤面前静脉及颌后静脉.%Objective: The aim of this study was to investigate the position and course of retromandibular vein using multi-detector row helical computed tomographic angiography (CTA)imaging and to relate the findings to performing the mandibular angle ptasty. Method: thirty of adulty human were selected for multi-detector row helical CTA measurement and ADW4.2 software analysis, according with a distance from the retromandibular vein to mandibular angle.at 10 mm urper the mandibular angletat 20 mm urper the mandibular angle,at 30 mm urper the mandibular angle, and at 40 mm urper the mandibular angle, retromandibular vein was examined. Result: the distance from the retromandibular vein to the mandibular angle is(11.26±2.34)mm.al 10 mm urper the mandibular angle is (8.18±2.12)mm.at 20 mm urper the mandibular angle is (6.38±2.12)mm,at 30 mm urper the mandibular angle is (3.18±2.12)mm,at 40 mm urper the mandibular angle is (2.18± 1.16)mm.Conclusion:The study is to provide further understanding of the retromandibular vein anatomy in relation to the design of the mandibuler angle plasty and to create clinical safety guidelines in order to avoid damaging

  1. Comparison of adaptive statistical iterative and filtered back projection reconstruction techniques in brain CT

    Energy Technology Data Exchange (ETDEWEB)

    Ren, Qingguo, E-mail: renqg83@163.com [Department of Radiology, Hua Dong Hospital of Fudan University, Shanghai 200040 (China); Dewan, Sheilesh Kumar, E-mail: sheilesh_d1@hotmail.com [Department of Geriatrics, Hua Dong Hospital of Fudan University, Shanghai 200040 (China); Li, Ming, E-mail: minli77@163.com [Department of Radiology, Hua Dong Hospital of Fudan University, Shanghai 200040 (China); Li, Jianying, E-mail: Jianying.Li@med.ge.com [CT Imaging Research Center, GE Healthcare China, Beijing (China); Mao, Dingbiao, E-mail: maodingbiao74@163.com [Department of Radiology, Hua Dong Hospital of Fudan University, Shanghai 200040 (China); Wang, Zhenglei, E-mail: Williswang_doc@yahoo.com.cn [Department of Radiology, Shanghai Electricity Hospital, Shanghai 200050 (China); Hua, Yanqing, E-mail: cjr.huayanqing@vip.163.com [Department of Radiology, Hua Dong Hospital of Fudan University, Shanghai 200040 (China)

    2012-10-15

    Purpose: To compare image quality and visualization of normal structures and lesions in brain computed tomography (CT) with adaptive statistical iterative reconstruction (ASIR) and filtered back projection (FBP) reconstruction techniques in different X-ray tube current–time products. Materials and methods: In this IRB-approved prospective study, forty patients (nineteen men, twenty-one women; mean age 69.5 ± 11.2 years) received brain scan at different tube current–time products (300 and 200 mAs) in 64-section multi-detector CT (GE, Discovery CT750 HD). Images were reconstructed with FBP and four levels of ASIR-FBP blending. Two radiologists (please note that our hospital is renowned for its geriatric medicine department, and these two radiologists are more experienced in chronic cerebral vascular disease than in neoplastic disease, so this research did not contain cerebral tumors but as a discussion) assessed all the reconstructed images for visibility of normal structures, lesion conspicuity, image contrast and diagnostic confidence in a blinded and randomized manner. Volume CT dose index (CTDI{sub vol}) and dose-length product (DLP) were recorded. All the data were analyzed by using SPSS 13.0 statistical analysis software. Results: There was no statistically significant difference between the image qualities at 200 mAs with 50% ASIR blending technique and 300 mAs with FBP technique (p > .05). While between the image qualities at 200 mAs with FBP and 300 mAs with FBP technique a statistically significant difference (p < .05) was found. Conclusion: ASIR provided same image quality and diagnostic ability in brain imaging with greater than 30% dose reduction compared with FBP reconstruction technique.

  2. 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 ...

  3. 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 ...

  4. 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 ...

  5. 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 ...

  6. 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 ...

  7. 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.

  8. 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 ...

  9. C-arm flat-panel CT arthrography of the wrist and elbow: first experiences in human cadavers

    Energy Technology Data Exchange (ETDEWEB)

    Guggenberger, Roman; Morsbach, Fabian; Alkadhi, Hatem; Pfammatter, Thomas; Hodler, Juerg; Andreisek, Gustav [University Hospital Zurich, Department of Radiology, Zurich (Switzerland); Vich, Magdalena [University Zurich, Institute of Anatomy, Zurich (Switzerland)

    2013-03-15

    To determine the optimal intra-articular iodine concentration for C-arm flat-panel computed tomography (FPCT) arthrography using advanced joint phantoms and to evaluate its application in human cadaveric wrists and elbows. Multi-detector (MD) CT served as the standard of reference. Joint phantoms and 10 human cadaveric wrist and elbow joints were scanned with C-arm FPCT (5-s, 8-s, and 20-s runs) and standard MDCT using different and optimal concentrations of iodinated contrast material. CT numbers of contrast material, tissue, and noise were measured and contrast-to-noise ratios (CNR) calculated for quantitative analysis. Image and depiction of cartilage, bone, and soft tissues were rated. Radiation doses were compared. In FPCT, iodine concentrations positively correlated with CT numbers and noise of contrast material and with radiation dose (r = 0.713-0.996, p < 0.05 each). At an iodine concentration of 45 mg/ml, CNR of cartilage and soft tissues were highest for all FPCT acquisitions and higher than in MDCT. The 20-s FPCT run performed best for image quality and depiction of anatomical structures and was rated overall equal to MDCT (p = 0.857). The optimal iodine concentration for C-arm FPCT arthrography in this study is 45 mg/ml, leading to superior CNR and image quality for an optimal FPCT protocol compared with standard MDCT arthrography in human cadaveric joints. (orig.)

  10. 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.)

  11. 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.)

  12. Comparison of 2 accelerators of Monte Carlo radiation transport calculations, NVIDIA tesla M2090 GPU and Intel Xeon Phi 5110p coprocessor: a case study for X-ray CT Imaging Dose calculation

    International Nuclear Information System (INIS)

    Hardware accelerators are currently becoming increasingly important in boosting high performance computing systems. In this study, we tested the performance of two accelerator models, NVIDIA Tesla M2090 GPU and Intel Xeon Phi 5110p coprocessor, using a new Monte Carlo photon transport package called ARCHER-CT we have developed for fast CT imaging dose calculation. The package contains three code variants, ARCHER-CT(CPU), ARCHER-CT(GPU) and ARCHER-CT(COP) to run in parallel on the multi-core CPU, GPU and coprocessor architectures respectively. A detailed GE LightSpeed Multi-Detector Computed Tomography (MDCT) scanner model and a family of voxel patient phantoms were included in the code to calculate absorbed dose to radiosensitive organs under specified scan protocols. The results from ARCHER agreed well with those from the production code Monte Carlo N-Particle eXtended (MCNPX). It was found that all the code variants were significantly faster than the parallel MCNPX running on 12 MPI processes, and that the GPU and coprocessor performed equally well, being 2.89-4.49 and 3.01-3.23 times faster than the parallel ARCHER-CT(CPU) running with 12 hyper-threads. (authors)

  13. Establishment of a semi-biological phantom model for the study of the effect of dose reducing measures on radiation-induced DNA double strand breaks in CT using the example of risk organ based tube current modulation; Etablierung eines semibiologischen Phantommodells zur Untersuchung des Effekts dosisreduzierender Massnahmen auf strahleninduzierte DNA-Doppelstrangbrueche in der CT am Beispiel der risikoorganbasierten Roehrenstrommodulation

    Energy Technology Data Exchange (ETDEWEB)

    Sommer, Matthias

    2013-12-12

    The number of computed tomography (CT) examinations has been rising during the last decades. Therefore techniques for dose reduction receive increasing attention. Risk organ-based tube current modulation (RCM) in CT is a new approach and works by lowering the tube current, while the tube is in front of the patient's body. Therefore it should lead to a dose reduction for radiosensitive organs like the female breast, the eye lenses and the thyroid gland. Biological radiation effects cannot be estimated by physical-based dose measurements. γ-H2AX is a sensitive marker for the determination of x-ray induced DNA double-strand breaks (DSB). Hence the aim of this study was to establish a biological phantom model based on the γ-H2AX immunofluorescence microscopy method and to investigate the effect of RCM on radiation induced DNA damages. The γ-H2AX method is based on the phosphorylation of the histone variant H2AX. The phosphorylated histone γ-H2AX can be visualised using antibodies and is specific for radiation induced DSB. Blood lymphocytes from healthy volunteers, skin fibroblasts (LN) and mammary epithelial cells (HMEpC-p) were placed in different positions of an Alderson-phantom and exposed to x-rays using a 128-slice dual-source CT scanner. Standard head, neck and chest-CT scan protocols either with or without risk-organ based tube current modulation were used. RCM reduces the tube current to 20 percent at an angle of 130 degree anterior to the body, whereas tube current is increased at an angle of 230 degree posterior to the body. Afterwards cells were isolated, fixed on slides und stained with specific primary γ-H2AX antibodies and fluorescent secondary antibodies. Tiny green dots (named foci) can be detected and quantified with a fluorescence microscope and represent distinct DSB. Non-irradiated samples served as controls and CT-induced DSB were calculated by subtraction of pre- from post-exposure values. In this study a semibiological phantom model

  14. 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

  15. CT-MR image data fusion for computer assisted navigated neurosurgery of temporal bone tumors

    International Nuclear Information System (INIS)

    Purpose: To demonstrate the value of multi detector computed tomography (MDCT) and magnetic resonance imaging (MRI) in the preoperative work up of temporal bone tumors and to present, especially, CT and MR image fusion for surgical planning and performance in computer assisted navigated neurosurgery of temporal bone tumors. Materials and methods: Fifteen patients with temporal bone tumors underwent MDCT and MRI. MDCT was performed in high-resolution bone window level setting in axial plane. The reconstructed MDCT slice thickness was 0.8 mm. MRI was performed in axial and coronal plane with T2-weighted fast spin-echo (FSE) sequences, un-enhanced and contrast-enhanced T1-weighted spin-echo (SE) sequences, and coronal T1-weighted SE sequences with fat suppression and with 3D T1-weighted gradient-echo (GE) contrast-enhanced sequences in axial plane. The 3D T1-weighted GE sequence had a slice thickness of 1 mm. Image data sets of CT and 3D T1-weighted GE sequences were merged utilizing a workstation to create CT-MR fusion images. MDCT and MR images were separately used to depict and characterize lesions. The fusion images were utilized for interventional planning and intraoperative image guidance. The intraoperative accuracy of the navigation unit was measured, defined as the deviation between the same landmark in the navigation image and the patient. Results: Tumorous lesions of bone and soft tissue were well delineated and characterized by CT and MR images. The images played a crucial role in the differentiation of benign and malignant pathologies, which consisted of 13 benign and 2 malignant tumors. The CT-MR fusion images supported the surgeon in preoperative planning and improved surgical performance. The mean intraoperative accuracy of the navigation system was 1.25 mm. Conclusion: CT and MRI are essential in the preoperative work up of temporal bone tumors. CT-MR image data fusion presents an accurate tool for planning the correct surgical procedure and is a

  16. CT-MR image data fusion for computer assisted navigated neurosurgery of temporal bone tumors

    Energy Technology Data Exchange (ETDEWEB)

    Nemec, Stefan Franz [Department of Radiology/Osteology, Medical University Vienna, Waehringerguertel 18-20, A-1090 Vienna (Austria)]. E-mail: stefan.nemec@meduniwien.ac.at; Donat, Markus Alexander [Department of Neurosurgery, Medical University Vienna, Waehringerguertel 18-20, A-1090 Vienna (Austria); Mehrain, Sheida [Department of Radiology/Osteology, Medical University Vienna, Waehringerguertel 18-20, A-1090 Vienna (Austria); Friedrich, Klaus [Department of Radiology/Osteology, Medical University Vienna, Waehringerguertel 18-20, A-1090 Vienna (Austria); Krestan, Christian [Department of Radiology/Osteology, Medical University Vienna, Waehringerguertel 18-20, A-1090 Vienna (Austria); Matula, Christian [Department of Neurosurgery, Medical University Vienna, Waehringerguertel 18-20, A-1090 Vienna (Austria); Imhof, Herwig [Department of Radiology/Osteology, Medical University Vienna, Waehringerguertel 18-20, A-1090 Vienna (Austria); Czerny, Christian [Department of Radiology/Osteology, Medical University Vienna, Waehringerguertel 18-20, A-1090 Vienna (Austria)

    2007-05-15

    Purpose: To demonstrate the value of multi detector computed tomography (MDCT) and magnetic resonance imaging (MRI) in the preoperative work up of temporal bone tumors and to present, especially, CT and MR image fusion for surgical planning and performance in computer assisted navigated neurosurgery of temporal bone tumors. Materials and methods: Fifteen patients with temporal bone tumors underwent MDCT and MRI. MDCT was performed in high-resolution bone window level setting in axial plane. The reconstructed MDCT slice thickness was 0.8 mm. MRI was performed in axial and coronal plane with T2-weighted fast spin-echo (FSE) sequences, un-enhanced and contrast-enhanced T1-weighted spin-echo (SE) sequences, and coronal T1-weighted SE sequences with fat suppression and with 3D T1-weighted gradient-echo (GE) contrast-enhanced sequences in axial plane. The 3D T1-weighted GE sequence had a slice thickness of 1 mm. Image data sets of CT and 3D T1-weighted GE sequences were merged utilizing a workstation to create CT-MR fusion images. MDCT and MR images were separately used to depict and characterize lesions. The fusion images were utilized for interventional planning and intraoperative image guidance. The intraoperative accuracy of the navigation unit was measured, defined as the deviation between the same landmark in the navigation image and the patient. Results: Tumorous lesions of bone and soft tissue were well delineated and characterized by CT and MR images. The images played a crucial role in the differentiation of benign and malignant pathologies, which consisted of 13 benign and 2 malignant tumors. The CT-MR fusion images supported the surgeon in preoperative planning and improved surgical performance. The mean intraoperative accuracy of the navigation system was 1.25 mm. Conclusion: CT and MRI are essential in the preoperative work up of temporal bone tumors. CT-MR image data fusion presents an accurate tool for planning the correct surgical procedure and is a

  17. 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 ...

  18. 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 ...

  19. 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 ...

  20. 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 ...

  1. 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 ...

  2. 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 ...

  3. 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 ...

  4. 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 ...

  5. 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 ...

  6. 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, ...

  7. Computed Tomography (CT) -- Sinuses

    Medline Plus

    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, ...

  8. 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.

  9. Computed Tomography (CT) -- Sinuses

    Medline Plus

    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 ...

  10. 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.

  11. 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...

  12. Computed Tomography (CT) -- Head

    Medline Plus

    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 ...

  13. Computed Tomography (CT) -- Sinuses

    Medline Plus

    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 ...

  14. 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 ...

  15. 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, ...

  16. 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, ...

  17. Computed Tomography (CT) -- Sinuses

    Medline Plus

    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, ...

  18. Computed Tomography (CT) -- Head

    Medline Plus

    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, ...

  19. Computed Tomography (CT) -- Head

    Medline Plus

    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 ...

  20. 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 ...

  1. Computed Tomography (CT) -- Head

    Medline Plus

    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 ...

  2. 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 ...

  3. 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 ...

  4. 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 ...

  5. Computed Tomography (CT) -- Sinuses

    Medline Plus

    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 ...

  6. 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- ...

  7. 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- ...

  8. 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 ...

  9. 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) - Sinuses ...

  10. Computed Tomography (CT) -- Head

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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 ...

  11. 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. ...

  12. 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. ...

  13. 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 ...

  14. 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 ...

  15. 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: ...

  16. 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: ...

  17. 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 ...

  18. Computed Tomography (CT) -- Sinuses

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    Full Text Available ... have special pediatric considerations. The teddy bear denotes child-specific content. Related Articles and Media Magnetic Resonance Imaging (MRI) - Head Head and Neck Cancer Treatment Radiation Dose in X-Ray and CT ...

  19. Computed Tomography (CT) -- Sinuses

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    Full Text Available ... microphone. top of page How does the procedure work? In many ways CT scanning works very much ... a few seconds, and even faster in small children. Such speed is beneficial for all patients but ...

  20. Computed Tomography (CT) -- Head

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    Full Text Available ... microphone. top of page How does the procedure work? In many ways CT scanning works very much ... a few seconds, and even faster in small children. Such speed is beneficial for all patients but ...

  1. Computed Tomography (CT) -- Sinuses

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    Full Text Available ... will analyze the images and send an official report to your primary care physician or physician who ... can be performed if you have an implanted medical device of any kind, unlike MRI. CT imaging ...

  2. Computed Tomography (CT) -- Sinuses

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    Full Text Available ... many types of tissue as well as the lungs, bones, and blood vessels. CT examinations are fast ... of many areas of the body, particularly the lungs, abdomen, pelvis and bones. A diagnosis determined by ...

  3. Computed Tomography (CT) -- Head

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    Full Text Available ... pictures of the inside of the body. The cross-sectional images generated during a CT scan can ... large volume of data to create two-dimensional cross-sectional images of your body, which are then ...

  4. Computed Tomography (CT) -- Sinuses

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    Full Text Available ... pictures of the inside of the body. The cross-sectional images generated during a CT scan can ... large volume of data to create two-dimensional cross-sectional images of your body, which are then ...

  5. Computed Tomography (CT) -- Sinuses

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    Full Text Available ... cavity. CT scanning is painless, noninvasive and accurate. It’s also the most reliable imaging technique for determining ... parts absorb the x-rays in varying degrees. It is this crucial difference in absorption that allows ...

  6. CT number definition

    International Nuclear Information System (INIS)

    The accuracy of CT number plots has been found lacking in several medical applications. This is of concern since the ability to compare and evaluate results on a reproducible and standard basis is essential to long term development. Apart from the technical limitations arising from the CT scanner and the data treatment, there are fundamental issues with the definition of the Hounsfield number, namely the absence of a standard photon energy and the need to specify the attenuation mechanism for standard measurements. This paper presents calculations to demonstrate the shortcomings of the present definition with a brief discussion. The remedy is straightforward, but probably of long duration as it would require an international agreement. - Highlights: ► The dependence of the CT number definition on photon energy is examined. ► Graphical examples of the CT number variation with photon energy are given. ► The influence of absorption edges and scattering on CT numbers is discussed. ► A proposal is made for an international standard devoted to CT number evaluation.

  7. CT-Urography

    International Nuclear Information System (INIS)

    In this paper we present an overview of CT-Urography. With the advent of multislice CT scanners and the evolution of image processing methods this technique now affords optimal urographic images comparable to those obtained with conventional techniques. We describe the acquisition techniques and protocols used by the various authors. Effective radiation dose has conditioned the use of CT-Urography so that the tendency today is to reduce the number of scans by performing, after the non enhanced scan, a single contrast-enhanced scan comprising both the nephrographic and urographic phase. With the use of multislice CT the quality of the urogram improves with the number of slices. We illustrate a variety of processing techniques, multiplanar reconstruction (MPR), maximum (MIP) and average intensity projection (AIP) and volume rendering (VR) and present a series of upper urinary tract tumours testifying to the superiority of the AIP technique over MIP. We then review the results of comparative studies of CT-Urography with conventional urography in upper urinary tract diagnostics. Finally, we describe the advantages and limitations of CT-Urography

  8. Wavelet-based calculation of cerebral angiographic data from time-resolved CT perfusion acquisitions

    Energy Technology Data Exchange (ETDEWEB)

    Havla, Lukas; Dietrich, Olaf [Ludwig-Maximilians-University Hospital Munich, Josef-Lissner-Laboratory for Biomedical Imaging, Institute for Clinical Radiology, Munich (Germany); Thierfelder, Kolja M.; Beyer, Sebastian E.; Sommer, Wieland H. [Ludwig-Maximilians-University Hospital Munich, Institute for Clinical Radiology, Munich (Germany)

    2015-08-15

    To evaluate a new approach for reconstructing angiographic images by application of wavelet transforms on CT perfusion data. Fifteen consecutive patients with suspected stroke were examined with a multi-detector CT acquiring 32 dynamic phases (∇t = 1.5s) of 99 slices (total slab thickness 99mm) at 80kV/200mAs. Thirty-five mL of iomeprol-350 was injected (flow rate = 4.5mL/s). Angiographic datasets were calculated after initial rigid-body motion correction using (a) temporally filtered maximum intensity projections (tMIP) and (b) the wavelet transform (Paul wavelet, order 1) of each voxel time course. The maximum of the wavelet-power-spectrum was defined as the angiographic signal intensity. The contrast-to-noise ratio (CNR) of 18 different vessel segments was quantified and two blinded readers rated the images qualitatively using 5pt Likert scales. The CNR for the wavelet angiography (501.8 ± 433.0) was significantly higher than for the tMIP approach (55.7 ± 29.7, Wilcoxon test p < 0.00001). Image quality was rated to be significantly higher (p < 0.001) for the wavelet angiography with median scores of 4/4 (reader 1/reader 2) than the tMIP (scores of 3/3). The proposed calculation approach for angiography data using temporal wavelet transforms of intracranial CT perfusion datasets provides higher vascular contrast and intrinsic removal of non-enhancing structures such as bone. (orig.)

  9. Dose reduction and image quality optimizations in CT of pediatric and adult patients: phantom studies

    Science.gov (United States)

    Jeon, P.-H.; Lee, C.-L.; Kim, D.-H.; Lee, Y.-J.; Jeon, S.-S.; Kim, H.-J.

    2014-03-01

    Multi-detector computed tomography (MDCT) can be used to easily and rapidly perform numerous acquisitions, possibly leading to a marked increase in the radiation dose to individual patients. Technical options dedicated to automatically adjusting the acquisition parameters according to the patient's size are of specific interest in pediatric radiology. A constant tube potential reduction can be achieved for adults and children, while maintaining a constant detector energy fluence. To evaluate radiation dose, the weighted CT dose index (CTDIw) was calculated based on the CT dose index (CTDI) measured using an ion chamber, and image noise and image contrast were measured from a scanned image to evaluate image quality. The dose-weighted contrast-to-noise ratio (CNRD) was calculated from the radiation dose, image noise, and image contrast measured from a scanned image. The noise derivative (ND) is a quality index for dose efficiency. X-ray spectra with tube voltages ranging from 80 to 140 kVp were used to compute the average photon energy. Image contrast and the corresponding contrast-to-noise ratio (CNR) were determined for lesions of soft tissue, muscle, bone, and iodine relative to a uniform water background, as the iodine contrast increases at lower energy (i.e., k-edge of iodine is 33 keV closer to the beam energy) using mixed water-iodine contrast normalization (water 0, iodine 25, 100, 200, and 1000 HU, respectively). The proposed values correspond to high quality images and can be reduced if only high-contrast organs are assessed. The potential benefit of lowering the tube voltage is an improved CNRD, resulting in a lower radiation dose and optimization of image quality. Adjusting the tube potential in abdominal CT would be useful in current pediatric radiography, where the choice of X-ray techniques generally takes into account the size of the patient as well as the need to balance the conflicting requirements of diagnostic image quality and radiation dose

  10. CT and MR urography

    International Nuclear Information System (INIS)

    Full text: Learning objectives:1) To describe the techniques of CT Urography and of MR urography; 2) To illustrate the benefit of the methods in clinical practice; 3)To present typical cases from the daily practice CT has become the mainstay of uroradiology in adults. CT urography is an excellent technique for the evaluation of urinary tract calculi, trauma, infections, complicated cysts, renal masses, having high sensitivity and specificity for both conditions facilitated by the possibilities for multiplanar imaging of the urinary system. It resembles excretory urography and consists of unenhanced, nephrographic, and pyelographic phases and can be used even as routine investigation. MR urography is a new, modern modality for evaluation of various urological abnormalities providing both morphological and functional information by means of different sequences with or without injection of gadolinium. The method is clinically useful in the evaluation of the collecting system, various variants and congenital abnormalities of the kidney, different cases of obstruction of the excretory system, tumors and inflammatory processes, hematuria. Compared to CT urography, MR urography is particularly beneficial in pediatric group or pregnant patients. It can also be performed in patients with renal insufficiency, iodine allergy and other cases of contraindications to the use of ionizing radiation. CT and MR urography are promising diagnostic methods of the wide spectrum of pathological conditions affecting the urinary tract. They are highly informative and overcome a lot of limitations of the other imaging modalities with the potential to become leading modalities to diagnose kidney diseases and other urogenital disorders.

  11. CT in dental osseointegration

    International Nuclear Information System (INIS)

    Computerised tomography (CT) plays a key role in the pre-surgical evaluation of the alveolar process for titanium dental implants. The successful replacement of lost teeth by tissue integrated tooth root implants is a major advance in clinical dentistry. The paper will discuss briefly the history of osseointegration and how CT is now involved in helping the edentulous patient. CT is considered as a quick and convenient method of obtaining excellent anatomical information about the maxilla. Conventional tomography is difficult to obtain and does not provide valuable cross-sectional images. Exact height and width calculations can be made as well as screening out patients with advanced bone resorption. 3 refs. 6 figs

  12. Axial skeletal CT densitometry

    International Nuclear Information System (INIS)

    Since the discovery of the Roentgen ray a precise and accurate assessment of bone mineral content has been a challenge to many investigators. A number of methods have been developed but no one satisfied. Considering its technical possibilities computed tomography is very promising in determination of bone mineral content (BMC). The new modality enables BMC estimations in the axial skeletal trabecular bone. CT densitometry can be performed on a normal commercially available third generation whole body CT scanner. No dedicated device in a special clinical set-up is necessary. In this study 106 patients, most of them clinically suspected of osteoporosis, were examined. The new method CT densitometry has been evaluated. The results have been correlated to alternative BMC determination methods. (Auth.)

  13. CT findings of fibromatoses

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hak Nam; Choi, Yeon Hwa; Shin, Hyun Jun [Lee Rha Hospital, Chung Ju (Korea, Republic of)

    1991-03-15

    Fibromatoses constitute a group of benign fibroblastic soft tissue tumors with a tendency for local invasion and recurrence. CT provides excellent anatomic detail of soft tissue tumors and precise location, size, and extent of the tumors. The authors evaluated 7 CT scans of 6 pathologically proven aggressive fibromatoses during the last 4 years. Five lesions arose in the lower extremities: 4 in the buttocks and 1 in the thigh. One lesion arose in the upper back. The tumors were lobulated in contour and varied in size from 3.7 cm to 10.7 cm. Fibromatosis tumors were usually hypodense with muscle when no contrast medium was used and hyperdense with better delineation during infusion of the contrast medium. Three patients had recurrent disease after surgical removal. Fibromatosis may infiltrate the surrounding tissue beyond the margins, indicated on CT scans and by palpation at operation. Therefore the surgeon should plan a wide resection around the apparent limits of the fibromatosis.

  14. Normal cranial CT anatomy

    International Nuclear Information System (INIS)

    The human brain consists of well-known anatomical components. Some parts of these components have been shown to be concerned with certain functions. A complete cranial CT examination consists of a series of several slices obtained in a sequence usually from the base to the vertex of the cranial vault, in the axial mode. The ultimate goal of this chapter is to pinpoint those slices that depict a given anatomical structure or several structures that deal with a given function. To achieve this goal, the discussion of CT cranial anatomy is presented in three sections

  15. PET-CT in oncology: making the most of CT

    OpenAIRE

    Miles, K. A.

    2008-01-01

    Abstract Combined positron emission tomography–computed tomography (PET-CT) has made a significant impact on cancer imaging. The use of CT to map tissue attenuation for correction of PET images and the ability to co-register the functional information provided by PET with the anatomical data afforded by CT, has resulted in demonstrable improvements in diagnostic accuracy. However, attenuation correction and anatomical localisation may not represent the full benefits of integrating CT with PET...

  16. Effect of x-ray tube current on the accuracy of cerebral perfusion parameters obtained by CT perfusion studies

    Science.gov (United States)

    Murase, Kenya; Nanjo, Takafumi; Satoshi, Ii; Miyazaki, Shohei; Hirata, Masaaki; Sugawara, Yoshifumi; Kudo, Masayuki; Sasaki, Kousuke; Mochizuki, Teruhito

    2005-11-01

    The purpose of this study was to investigate the effect of x-ray tube current on the accuracy of cerebral perfusion parameters obtained by CT perfusion studies using multi-detector row CT (MDCT). Following the standard CT perfusion study protocol, continuous (cine) scans (1 s/rotation × 60 s) consisting of four 5 mm thick contiguous slices were performed using an MDCT scanner with a tube voltage of 80 kVp and a tube current of 200 mA. We generated the simulated images with tube currents of 50 mA, 100 mA and 150 mA by adding the corresponding noise to the raw scan data of the original image acquired above using a noise simulation tool. From the original and simulated images, we generated the functional images of cerebral blood flow (CBF), cerebral blood volume (CBV) and mean transit time (MTT) in seven patients with cerebrovascular disease, and compared the correlation coefficients (CCs) between the perfusion parameter values obtained from the original and simulated images. The coefficients of variation (CVs) in the white matter were also compared. The CC values deteriorated with decreasing tube current. There was a significant difference between 50 mA and 100 mA for all perfusion parameters. The CV values increased with decreasing tube current. There were significant differences between 50 mA and 100 mA and between 100 mA and 150 mA for CBF. For CBV and MTT, there was also a significant difference between 150 mA and 200 mA. This study will be useful for understanding the effect of x-ray tube current on the accuracy of cerebral perfusion parameters obtained by CT perfusion studies using MDCT, and for selecting the tube current.

  17. MSCT重组技术对气管破裂的诊断价值%Multi-slice CT and advanced reconstruction techniques in the diagnosis of tracheal rupture

    Institute of Scientific and Technical Information of China (English)

    杨鸿; 杨文; 蒋洪春; 彭湘晖; 曹林德

    2012-01-01

    Objective:To assess the value of multi slice CT (MSCT) with reconstruction techniques in the diagnosis of tracheal rupture. Methods: 128 slice spiral CT (MSCT) scanning was performed in 7 patients with tracheal rupture caused by severe trauma to the neck and thorax,iatrogenic injury and spontaneous tracheal rupture. The images of multipla nar reconstruction (MPR) ,CT virtual endoscopy (CTVE) were obtained on a postprocessing workstation. Results: CT ap pearances of tracheal rupture included defect in trachea with deep cervical air or air tracking into the mediastinum. MPR clearly displayed the shape and size of tracheal defect,the distances between the tracheal defect to some important anatomic landmarks such as tracheal carina, epiglottis and superior border of the manubrium. CTVE showed the tracheal defects in the 5 patients with trauma to the neck and thorax and spontaneous tracheal ruptures. However,the image of CTVE was a little blurred than MPR. Color coded volume rendered images provided realistic 3D views of air leak distribution of the tra cheal rupture. Conclusion: MSCT with reconstruction techniques play an important role in the diagnosis and treatment of tra cheal rupture.%目的:探讨MSCT重组技术对气管破裂的诊断及临床应用价值.方法:回顾性分析7例气管破裂患者的CT资料,病因分别为颈胸部严重外伤、医源性损伤、自发性因素.采用128层螺旋CT对7例患者行颈胸部平扫,原始数据行减薄重组,将减薄重组后的图像传输到工作站进行多平面重组及CT仿真内窥镜(CTVE)观察.结果:气管破口以及溢出的气体均表现为低密度影,气管壁连续性中断,MPR重组可以完整显示破裂口形态和大小、距气管隆突、会厌或胸骨柄上缘等重要解剖标志的距离;2例严重患者在双侧颜面部、颈部、颞下窝、咽旁组织间隙、前后胸壁皮下、纵隔内均有广泛分布的低密度气影;最轻的1例仅见裂口附近的后纵隔内

  18. Assessment of lobar perfusion in smokers according to the presence and severity of emphysema: preliminary experience with dual-energy CT angiography

    Energy Technology Data Exchange (ETDEWEB)

    Pansini, Vittorio; Remy-Jardin, Martine; Faivre, Jean-Baptiste; Remy, Jacques [University Center of Lille (EA 2694), Department of Thoracic Imaging, Hospital Calmette, Lille cedex (France); Schmidt, Bernhard [Siemens Medical Systems, Department of Research and Development, Forchheim (Germany); Dejardin-Bothelo, Alexis; Perez, Thierry [University Center of Lille, Department of Pulmonary Function Tests, Hospital Calmette, Lille cedex (France); Delannoy, Valerie; Duhamel, Alain [University Center of Lille (EA 2694), Department of Biostatistics, Lille cedex (France)

    2009-12-15

    The purpose of the study was to assess pulmonary perfusion on a lobar level in smokers using dual-energy computed tomography (CT). Forty-seven smokers and ten non-smokers underwent a dual-energy multi-detector CT angiogram of the chest that allowed automatic quantification of emphysema and determination of the iodine content at the level of the microcirculation (i.e. ''perfusion imaging''). Emphysema was present in 37 smokers and absent in ten smokers. Smokers with an upper lobe predominance of emphysema (n = 8) had: (1) significantly lower attenuation enhancement values in the upper lobes compared with smokers without emphysema; (2) the lobes with the most severe emphysematous changes had a statistically significantly higher percentage of emphysema (p = 0.0001) and lower mean attenuation enhancement values (p = 0.0001) than the ipsilateral lobes with less severe emphysema, matching parenchymal destruction; (3) a correlation was found between the difference in percentage of emphysema between the upper and lower lobes and the difference in attenuation attenuation enhancement values in the corresponding lobes (p = 0.0355; r = -0.54). Regional alterations of lung perfusion can be depicted by dual-energy CT in smokers with predominant emphysema. (orig.)

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

    Medline Plus

    Full Text Available ... with the CT technologist or nurse at the time of the CT examination. If your child has ... detectors rotate around the patient. At the same time, the examination table is moving through the scanner, ...

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

    Medline Plus

    Full Text Available ... the body, in a shorter period of time. Modern CT scanners are so fast that they can ... ensure that he/she is properly positioned. With modern CT scanners, your child will hear only slight ...

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

    Medline Plus

    Full Text Available ... top of page What are the benefits vs. risks? Benefits Using a multidetector CT unit to examine ... CT scans should have no immediate side effects. Risks The risk of serious allergic reaction to contrast ...

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

    Medline Plus

    Full Text Available ... sensitive to radiation, they should have a CT study only if it is essential for making a diagnosis and should not have repeated CT studies unless absolutely necessary. top of page What are ...

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

    Medline Plus

    Full Text Available ... obtain CT images. It is known that high levels of radiation may cause cancer. However, CT scans result in a low-level exposure. Whether such levels cause cancer is debatable ...

  4. Abdominal CT scan

    Science.gov (United States)

    ... than regular x-rays. Many x-rays or CT scans over time may increase your risk for cancer. However, the risk from any one scan is small. Talk to your doctor about this risk and the benefit of the test for getting a correct diagnosis ...

  5. Computed Tomography (CT) -- Sinuses

    Medline Plus

    Full Text Available ... Rotating around you, the x-ray tube and electronic x-ray detectors are located opposite each other ... another on an x-ray film or CT electronic image. In a conventional x-ray exam, a ...

  6. Hepatic angiosarcoma: CT findings

    Institute of Scientific and Technical Information of China (English)

    余日胜; 章士正; 华建明

    2003-01-01

    @@ Hepatic angiosarcoma is a rare malignant vascular tumor. Accurate preoperative diagnosis of this tumor is very difficult if the patient does not have any history of exposure to specific carcinogens including thorotrast, arsenicals and vinyl chloride monomer. We describe CT findings in two cases of hepatic angiosarcoma in combination with a review of the literature.

  7. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... can be performed if you have an implanted medical device of any kind, unlike MRI. A diagnosis determined by CT scanning may eliminate the need for exploratory surgery and surgical biopsy. No radiation remains ... is not a medical facility. Please contact your physician with specific medical ...

  8. Computed Tomography (CT) -- Sinuses

    Medline Plus

    Full Text Available ... can be performed if you have an implanted medical device of any kind, unlike MRI. CT imaging provides real-time imaging, making it a good tool for guiding minimally invasive procedures such as needle ... is not a medical facility. Please contact your physician with specific medical ...

  9. Abdominal aspergillosis: CT findings

    Energy Technology Data Exchange (ETDEWEB)

    Yeom, Suk Keu, E-mail: pagoda20@hanmail.net [Department of Radiology and Research Institute of Radiology, Asan Medical Center, University of Ulsan College of Medicine, 388-1, Poongnap2-dong, Songpa-gu, Seoul, 138-736 (Korea, Republic of); Kim, Hye Jin, E-mail: kimhyejin@amc.seoul.kr [Department of Radiology and Research Institute of Radiology, Asan Medical Center, University of Ulsan College of Medicine, 388-1, Poongnap2-dong, Songpa-gu, Seoul, 138-736 (Korea, Republic of); Byun, Jae Ho, E-mail: jhbyun@amc.seoul.kr [Department of Radiology and Research Institute of Radiology, Asan Medical Center, University of Ulsan College of Medicine, 388-1, Poongnap2-dong, Songpa-gu, Seoul, 138-736 (Korea, Republic of); Kim, Ah Young, E-mail: aykim@amc.seoul.kr [Department of Radiology and Research Institute of Radiology, Asan Medical Center, University of Ulsan College of Medicine, 388-1, Poongnap2-dong, Songpa-gu, Seoul, 138-736 (Korea, Republic of); Lee, Moon-Gyu, E-mail: mglee@amc.seoul.kr [Department of Radiology and Research Institute of Radiology, Asan Medical Center, University of Ulsan College of Medicine, 388-1, Poongnap2-dong, Songpa-gu, Seoul, 138-736 (Korea, Republic of); Ha, Hyun Kwon, E-mail: hkha@amc.seoul.kr [Department of Radiology and Research Institute of Radiology, Asan Medical Center, University of Ulsan College of Medicine, 388-1, Poongnap2-dong, Songpa-gu, Seoul, 138-736 (Korea, Republic of)

    2011-03-15

    Objective: In order to retrospectively evaluate the CT findings of abdominal aspergillosis in immunocompromised patients. Materials and methods: CT scans were reviewed with regard to the sites, number, morphologic appearance, attenuation, and the contrast enhancement patterns of the lesions in six patients (5 women, 1 man; mean age, 43.4 years; range, 23-59 years) with pathologically proved abdominal aspergillosis by two gastrointestinal radiologists in consensus. Medical records were also reviewed to determine each patient's clinical status and outcome. Results: All patients were immunocompromised state: 4 patients received immunosuppressive therapy for solid organ transplantation and 2 patients received chemotherapy for acute myeloid leukemia. Aspergillosis involved blood vessels (n = 3), liver (n = 2), spleen (n = 2), gastrointestinal tract (n = 2), native kidney (n = 1), transplanted kidney (n = 1), peritoneum (n = 1), and retroperitoneum (n = 1). CT demonstrated solid organ or bowel infarction or perforation secondary to vascular thrombosis or pseudoaneurysm, multiple low-attenuating lesions of solid organs presenting as abscesses, concentric bowel wall thickening mimicking typhlitis, or diffuse or nodular infiltration of the peritoneum and retroperitoneum. Conclusion: Familiarity with findings commonly presenting as angioinvasive features or abscesses on CT, may facilitate the diagnosis of rare and fatal abdominal aspergillosis.

  10. Computed Tomography (CT) -- Sinuses

    Medline Plus

    Full Text Available ... of data to create two-dimensional cross-sectional images of your body, which are then displayed on a monitor. CT ... during the scanning. Any motion, whether breathing or body movements, can lead to artifacts on the images. This loss of image quality can resemble the ...

  11. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... of data to create two-dimensional cross-sectional images of your body, which are then displayed on a monitor. CT ... during the scanning. Any motion, whether breathing or body movements, can lead to artifacts on the images. This loss of image quality can resemble the ...

  12. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... Rotating around you, the x-ray tube and electronic x-ray detectors are located opposite each other ... another on an x-ray film or CT electronic image. In a conventional x-ray exam, a ...

  13. Refining CT colonography methods

    NARCIS (Netherlands)

    T.N. Boellaard

    2013-01-01

    CT-colografie is een structurele radiologische techniek om de dikke darm te onderzoeken op poliepen en kanker. De techniek wordt in de klinische praktijk gebuikt wanneer coloscopie incompleet is, maar ook als alternatief voor coloscopie. Alle technieken hebben hun beperkingen en voor sommige aspecte

  14. Pulmonary hypertension CT imaging

    International Nuclear Information System (INIS)

    Full text: The right heart catheterization is the gold standard in the diagnosis and determines the severity of pulmonary hypertension. The significant technical progress of noninvasive diagnostic imaging methods significantly improves the pixel density and spatial resolution in the study of cardiovascular structures, thus changes their role and place in the overall diagnostic plan. Learning points: What is the etiology, clinical manifestation and general pathophysiological disorders in pulmonary hypertension. What are the established diagnostic methods in the diagnosis and follow-up of patients with pulmonary hypertension. What is the recommended protocol for CT scanning for patients with clinically suspected or documented pulmonary hypertension. What are the important diagnostic findings in CT scan of a patient with pulmonary hypertension. Discussion: The prospect of instantaneous complex - anatomical and functional cardiopulmonary and vascular diagnostics seems extremely attractive. The contrast enhanced multislice computed (CT ) and magnetic resonance imaging are very suitable methods for imaging the structures of the right heart, with the possibility of obtaining multiple projections and three-dimensional imaging reconstructions . There are specific morphological features that, if carefully analyzed, provide diagnostic information. Thus, it is possible to avoid or at least reduce the frequency of use of invasive diagnostic cardiac catheterization in patients with pulmonary hypertension. Conclusion: This review focuses on the use of contrast-enhanced CT for comprehensive evaluation of patients with pulmonary hypertension and presents the observed characteristic changes in the chest, lung parenchyma , the structures of the right half of the heart and pulmonary vessels

  15. Abdominal aspergillosis: CT findings

    International Nuclear Information System (INIS)

    Objective: In order to retrospectively evaluate the CT findings of abdominal aspergillosis in immunocompromised patients. Materials and methods: CT scans were reviewed with regard to the sites, number, morphologic appearance, attenuation, and the contrast enhancement patterns of the lesions in six patients (5 women, 1 man; mean age, 43.4 years; range, 23-59 years) with pathologically proved abdominal aspergillosis by two gastrointestinal radiologists in consensus. Medical records were also reviewed to determine each patient's clinical status and outcome. Results: All patients were immunocompromised state: 4 patients received immunosuppressive therapy for solid organ transplantation and 2 patients received chemotherapy for acute myeloid leukemia. Aspergillosis involved blood vessels (n = 3), liver (n = 2), spleen (n = 2), gastrointestinal tract (n = 2), native kidney (n = 1), transplanted kidney (n = 1), peritoneum (n = 1), and retroperitoneum (n = 1). CT demonstrated solid organ or bowel infarction or perforation secondary to vascular thrombosis or pseudoaneurysm, multiple low-attenuating lesions of solid organs presenting as abscesses, concentric bowel wall thickening mimicking typhlitis, or diffuse or nodular infiltration of the peritoneum and retroperitoneum. Conclusion: Familiarity with findings commonly presenting as angioinvasive features or abscesses on CT, may facilitate the diagnosis of rare and fatal abdominal aspergillosis.

  16. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... other medical conditions and whether you have a history of heart disease, asthma, diabetes, kidney disease or ... gantry. The computer workstation that processes the imaging information is located ... in detector technology allow nearly all CT scanners to obtain multiple ...

  17. Computed Tomography (CT) -- Sinuses

    Medline Plus

    Full Text Available ... other medical conditions and whether you have a history of heart disease, asthma, diabetes, kidney disease or ... gantry. The computer workstation that processes the imaging information is located ... in detector technology allow nearly all CT scanners to obtain multiple ...

  18. Computed Tomography (CT) -- Sinuses

    Medline Plus

    Full Text Available ... Computed tomography (CT) of the sinuses uses special x-ray equipment to evaluate the paranasal sinus cavities – hollow, ... is a diagnostic medical test that, like traditional x-rays, produces multiple images or pictures of the inside ...

  19. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... Computed tomography (CT) of the head uses special x-ray equipment to help assess head injuries, severe headaches, ... is a diagnostic medical test that, like traditional x-rays, produces multiple images or pictures of the inside ...

  20. Seventh-generation CT

    Science.gov (United States)

    Besson, G. M.

    2016-03-01

    A new dual-drum CT system architecture has been recently introduced with the potential to achieve significantly higher temporal resolution than is currently possible in medical imaging CT. The concept relies only on known technologies; in particular rotation speeds several times higher than what is possible today could be achieved leveraging typical x-ray tube designs and capabilities. However, the architecture lends itself to the development of a new arrangement of x-ray sources in a toroidal vacuum envelope containing a rotating cathode ring and a (optionally rotating) shared anode ring to potentially obtain increased individual beam power as well as increase total exposure per rotation. The new x-ray source sub-system design builds on previously described concepts and could make the provision of multiple conventional high-power cathodes in a CT system practical by distributing the anode target between the cathodes. In particular, relying on known magnetic-levitation technologies, it is in principle possible to more than double the relative speed of the electron-beam with respect to the target, thus potentially leading to significant individual beam power increases as compared to today's state-of-the-art. In one embodiment, the proposed design can be naturally leveraged by the dual-drum CT concept previously described to alleviate the problem of arranging a number of conventional rotating anode-stem x-ray tubes and power conditioners on the limited space of a CT gantry. In another embodiment, a system with three cathodes is suggested leveraging the architecture previously proposed by Franke.

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

    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 ...

  2. Technical aspects of CT scanning.

    Science.gov (United States)

    Maravilla, K R; Pastel, M S

    1978-01-01

    The advent of computed tomography (CT) has initiated a technological revolution which continues to the present time. A brief review of basic principles of CT scanning is presented, and the evolution of modern CT scanner systems is traced. Some early indications of future trends are also presented.

  3. Venous thromboembolic disease. CT evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Goodman, L. R. [Medical College of Wisconsin, Pulmonary Medicine and Intensive Care, Dept. of Diagnostic Radiology, Milwaukee, WI (United States)

    2001-12-01

    Helical and multidetector CT has proven to be a valuable imaging modality for both pulmonary embolism and deep venous thrombosis. This paper will review the sensitivity and specificity of CT and discuss diagnostic algorithms utilizing CT and more established imaging technologies.

  4. Development of a Radiation Dose Reporting Software for X-ray Computed Tomography (CT)

    Science.gov (United States)

    Ding, Aiping

    X-ray computed tomography (CT) has experienced tremendous technological advances in recent years and has established itself as one of the most popular diagnostic imaging tools. While CT imaging clearly plays an invaluable role in modern medicine, its rapid adoption has resulted in a dramatic increase in the average medical radiation exposure to the worldwide and United States populations. Existing software tools for CT dose estimation and reporting are mostly based on patient phantoms that contain overly simplified anatomies insufficient in meeting the current and future needs. This dissertation describes the development of an easy-to-use software platform, “VirtualDose”, as a service to estimate and report the organ dose and effective dose values for patients undergoing the CT examinations. “VirtualDose” incorporates advanced models for the adult male and female, pregnant women, and children. To cover a large portion of the ignored obese patients that frequents the radiology clinics, a new set of obese male and female phantoms are also developed and applied to study the effects of the fat tissues on the CT radiation dose. Multi-detector CT scanners (MDCT) and clinical protocols, as well as the most recent effective dose algorithms from the International Commission on Radiological Protection (ICRP) Publication 103 are adopted in “VirtualDose” to keep pace with the MDCT development and regulatory requirements. A new MDCT scanner model with both body and head bowtie filter is developed to cover both the head and body scanning modes. This model was validated through the clinical measurements. A comprehensive slice-by-slice database is established by deriving the data from a larger number of single axial scans simulated on the patient phantoms using different CT bowtie filters, beam thicknesses, and different tube voltages in the Monte Carlo N-Particle Extended (MCNPX) code. When compared to the existing CT dose software packages, organ dose data in this

  5. Dynamic CT myocardial perfusion imaging.

    Science.gov (United States)

    Caruso, Damiano; Eid, Marwen; Schoepf, U Joseph; Jin, Kwang Nam; Varga-Szemes, Akos; Tesche, Christian; Mangold, Stefanie; Spandorfer, Adam; Laghi, Andrea; De Cecco, Carlo N

    2016-10-01

    Non-invasive cardiac imaging has rapidly evolved during the last decade due to advancements in CT based technologies. Coronary CT angiography has been shown to reliably assess coronary anatomy and detect high risk coronary artery disease. However, this technique is limited to anatomical assessment, thus non-invasive techniques for functional assessment of the heart are necessary. CT myocardial perfusion is a new CT based technique that provides functional assessment of the myocardium and allows for a comprehensive assessment of coronary artery disease with a single modality when combined with CTA. This review aims to discuss dynamic CT myocardial perfusion as a new technique in the assessment of CAD.

  6. Regularization design for high-quality cone-beam CT of intracranial hemorrhage using statistical reconstruction

    Science.gov (United States)

    Dang, H.; Stayman, J. W.; Xu, J.; Sisniega, A.; Zbijewski, W.; Wang, X.; Foos, D. H.; Aygun, N.; Koliatsos, V. E.; Siewerdsen, J. H.

    2016-03-01

    Intracranial hemorrhage (ICH) is associated with pathologies such as hemorrhagic stroke and traumatic brain injury. Multi-detector CT is the current front-line imaging modality for detecting ICH (fresh blood contrast 40-80 HU, down to 1 mm). Flat-panel detector (FPD) cone-beam CT (CBCT) offers a potential alternative with a smaller scanner footprint, greater portability, and lower cost potentially well suited to deployment at the point of care outside standard diagnostic radiology and emergency room settings. Previous studies have suggested reliable detection of ICH down to 3 mm in CBCT using high-fidelity artifact correction and penalized weighted least-squared (PWLS) image reconstruction with a post-artifact-correction noise model. However, ICH reconstructed by traditional image regularization exhibits nonuniform spatial resolution and noise due to interaction between the statistical weights and regularization, which potentially degrades the detectability of ICH. In this work, we propose three regularization methods designed to overcome these challenges. The first two compute spatially varying certainty for uniform spatial resolution and noise, respectively. The third computes spatially varying regularization strength to achieve uniform "detectability," combining both spatial resolution and noise in a manner analogous to a delta-function detection task. Experiments were conducted on a CBCT test-bench, and image quality was evaluated for simulated ICH in different regions of an anthropomorphic head. The first two methods improved the uniformity in spatial resolution and noise compared to traditional regularization. The third exhibited the highest uniformity in detectability among all methods and best overall image quality. The proposed regularization provides a valuable means to achieve uniform image quality in CBCT of ICH and is being incorporated in a CBCT prototype for ICH imaging.

  7. Association between coronary artery calcification score as assessed by multi-detector row computed tomography and cardiovascular risk factors%冠状动脉钙化积分与冠心病危险因素的相关性

    Institute of Scientific and Technical Information of China (English)

    张剑; 韩雅玲; 荆全民; 王效增; 李毅; 张磊; 霍勇; 张岩

    2011-01-01

    Objective The coronary artery calcification (CAC) score determined by multi-detector row computed tomography ( MDCT) predicts the onset of coronary artery disease (CAD). In addition, cardiovascular risk factors also predict the mortality of CAD. Therefore, the aim of this study was to assess whether or not the CAC score is associated with cardiovascular risk factors. Methods A total of 9847 consecutive patients with suspected coronary artery disease underwent coronary angiography between January 2001 and March 2007 at 20 centers of China were enrolled. The subjects consisted of 311 consecutive patients with suspected CAD who underwent MDCT. The body mass index, blood pressure, blood glucose, and serum total cholesterol, triglyceride and low-density lipoprotein cholesterol ( LDL-C) and high-density lipoprotein cholesterol ( HDL-C) were measured. Results When the patients were divided into three groups according to the CAC score [low (0-12 IU), intermediate ( 13 - 445 ) and high ( 5* 446) ], the classification score was significantly associated with age, prevalence of cardiovascular history and diabetes mellitus and HDL-C. In multivariate logistic regression analysis, age ( P = 0. 013) and plasma levels of high-density lipoprotein cholesterol ( P = 0.020 ) remained significant independent variables for the classification. Conclusions Age, prevalence of cardiovascular history and diabetes mellitus and HDL-C were significantly associated with the classification according to the CAC score. The detection of CACS by MSCT could provide reliable and efective evidence for diagnosis of CHD in patients with cardiovascular risk factors.%目的 经多层冠状动脉CT检查测定的冠状动脉钙化积分对冠心病的诊断具有一定预测价值.而冠心病的危险因素与冠心病的发生、发展、结局和预后密切相关.我们旨在探讨冠状动脉钙化积分与冠心病诸多危险因素之间是否具有相关性.方法 入选2001年1月至2007年3

  8. CT findings in mucopolysaccharidoses

    International Nuclear Information System (INIS)

    The CT findings for four patients with mucopolysaccharidosis were analyzed using a Delta scan-25 (Ohio Nuclear). In three cases of Hunter's syndrome (MPS IIA 13-year-old male, MPS IIB 12-year-old male, and 25-year-old male), a dilatation of the cortical sulci was observed. Moderate dilatations were also seen in the basal cistern, the quadrigeminal cistern, and the ambient cistern. In one case of Hunter's syndrome, a low-density area was observed in the bilateral tharamic regions. An irregular low-density area was also seen in the white matter in some cases. PVL was not apparent in any case. Marked ventricular dilations were observed in cases with mental retardation, for example, in one case of Hurler's syndrome (8-year-old male) and one case of MPS IIA. The circulation and absorbtion of CSF in cortical snbarachnoid spaces were supposed to be moderately retarded by metrizamide CT cisternography. (author)

  9. CT colonography: an update

    Energy Technology Data Exchange (ETDEWEB)

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

    2008-03-15

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

  10. CT findings of ganglioneuroma

    Energy Technology Data Exchange (ETDEWEB)

    Jeon, Tae Joo; Yoon, Choon Sik; Kim, Myung Jun; Kim, Sang Jin; Oh, Ki Keun [Yonsei Univ., College of Medicine, Seoul (Korea, Republic of)

    1998-09-01

    Ganglioneuroma is a relatively uncommon benign tumor and has no pathognomonic radiological findings;diagnosis is therefore difficult. In order to better diagnose this tumor we analysed its CT findings and pathologic correlation. Seventeen tumors in 16 patients(M:F=3D9:7) diagnosed as ganglioneuroma between 1992 and 1996 were retrospectively analysed with regard to location, size, contour, long axis of the mass, enhancement pattern, calcification, necrosis and capsulation, all as seen on CT, and compared with histo-pathologic findings. Tumors were 1.5 to 10(mean, 5.6) cm in size, and their location was mediastinal(n=3D12), cervical(n=3D2), retroperitoneal (n=3D2) or adrenal(n=3D1). Fifteen had an oval or round contour and two were dumb-bell-shaped. The long axis of the lesion was craniocaudal in 14 cases and non-specific in three. Thirteen lesions showed heterogeneous enhancement, and four homogeneous. Capsule-like enhancement was noted on CT scans in eight cases;there was no definite correlation between enhancement pattern and pathologic findings. Calcification was seen in six cases and an inner low-density lesion in two. Ganglioneuroma is a benign neurogenic tumor, occurring most frequently at the posterior mediastinum. General CT findings of this tumor are a well-defined oval shape with a variable enhancement pattern, but several cases showed focal calcification or inner low density. For accurate diagnosis of ganglioneuroma both common and uncommon findings must therefore be considered.=20.

  11. Quantitative micro-CT

    Science.gov (United States)

    Prevrhal, Sven

    2005-09-01

    Micro-CT for bone structural analysis has progressed from an in-vitro laboratory technique to devices for in-vivo assessment of small animals and the peripheral human skeleton. Currently, topological parameters of bone architecture are the primary goals of analysis. Additional measurement of the density or degree of mineralization (DMB) of trabecular and cortical bone at the microscopic level is desirable to study effects of disease and treatment progress. This information is not commonly extracted because of the challenges of accurate measurement and calibration at the tissue level. To assess the accuracy of micro-CT DMB measurements in a realistic but controlled situation, we prepared bone-mimicking watery solutions at concentrations of 100 to 600 mg/cm3 K2PO4H and scanned them with micro-CT, both in glass vials and microcapillary tubes with inner diameters of 50, 100 and 150 μm to simulate trabecular thickness. Values of the linear attenuation coefficients μ in the reconstructed image are commonly affected by beam hardening effects for larger samples and by partial volume effects for small volumes. We implemented an iterative reconstruction technique to reduce beam hardening. Partial voluming was sought to be reduced by excluding voxels near the tube wall. With these two measures, improvement on the constancy of the reconstructed voxel values and linearity with solution concentration could be observed to over 90% accuracy. However, since the expected change in real bone is small more measurements are needed to confirm that micro-CT can indeed be adapted to assess bone mineralization at the tissue level.

  12. Cine CT for Attenuation Correction in Cardiac PET/CT

    OpenAIRE

    Alessio, Adam M.; Kohlmyer, Steve; Branch, Kelley; Chen, Grace; Caldwell, James; Kinahan, Paul

    2007-01-01

    In dual-modality PET/CT systems, the CT scan provides the attenuation map for PET attenuation correction. The current clinical practice of obtaining a single helical CT scan provides only a snapshot of the respiratory cycle, whereas PET occurs over multiple respiratory cycles. Misalignment of the attenuation map and emission image because of respiratory motion causes errors in the attenuation correction factors and artifacts in the attenuation-corrected PET image. To rectify this problem, we ...

  13. Methods of selection in heavy ion collisions at Fermi energies and de-excitation modes with the INDRA multi-detector; Methodes de tri dans les collisions d'ions lourds aux energies de Fermi et modes de desexcitation avec le multidetecteur INDRA

    Energy Technology Data Exchange (ETDEWEB)

    Lautesse, Ph

    2005-11-15

    The progress made in particle detection, particularly the design of multi-detectors, like INDRA, that cover a solid angle of almost 4{pi}, have given a new impetus to heavy ion collisions. These detectors are demanding for an efficient way of selecting events that have a common history or similar features, for instance the events representing the de-excitation of a unique emitter. The problem is to find the adequate variable on which the discrimination can be based. Different methods are proposed in this work, the common point is that they require efficient models to reproduce and analyse experimental data in order to apprehend the equation of state of nuclear matter. Most of these models are based on the numerically solving of the nuclear Boltzmann equation. The application to the Ni + Ni reaction with an energy ranging from a few A.MeV to more than 50 A.MeV illustrates this work. (A.C.)

  14. Dose reduction assessment in dynamic CT myocardial perfusion imaging in a porcine balloon-induced-ischemia model

    Science.gov (United States)

    Fahmi, Rachid; Eck, Brendan L.; Vembar, Mani; Bezerra, Hiram G.; Wilson, David L.

    2014-03-01

    We investigated the use of an advanced hybrid iterative reconstruction (IR) technique (iDose4, Philips Health- care) for low dose dynamic myocardial CT perfusion (CTP) imaging. A porcine model was created to mimic coronary stenosis through partial occlusion of the left anterior descending (LAD) artery with a balloon catheter. The severity of LAD occlusion was adjusted with FFR measurements. Dynamic CT images were acquired at end-systole (45% R-R) using a multi-detector CT (MDCT) scanner. Various corrections were applied to the acquired scans to reduce motion and imaging artifacts. Absolute myocardial blood flow (MBF) was computed with a deconvolution-based approach using singular value decomposition (SVD). We compared a high and a low dose radiation protocol corresponding to two different tube-voltage/tube-current combinations (80kV p/100mAs and 120kV p/150mAs). The corresponding radiation doses for these protocols are 7.8mSv and 34.3mSV , respectively. The images were reconstructed using conventional FBP and three noise-reduction strengths of the IR method, iDose. Flow contrast-to-noise ratio, CNRf, as obtained from MBF maps, was used to quantitatively evaluate the effect of reconstruction on contrast between normal and ischemic myocardial tissue. Preliminary results showed that the use of iDose to reconstruct low dose images provide better or comparable CNRf to that of high dose images reconstructed with FBP, suggesting significant dose savings. CNRf was improved with the three used levels of iDose compared to FBP for both protocols. When using the entire 4D dynamic sequence for MBF computation, a 77% dose reduction was achieved, while considering only half the scans (i.e., every other heart cycle) allowed even further dose reduction while maintaining relatively higher CNRf.

  15. CT number variations in micro CT imaging systems

    Science.gov (United States)

    Tu, Shu-Ju; Hsieh, Hui-Ling; Chao, Tsi-Chian

    2008-03-01

    CT numbers can be directly computed from the linear attenuation coefficients in the reconstructed CT images and are correlated to the electron densities of the chemical elements with specific atomic numbers. However, the computed CT numbers can be varied when different imaging parameters are used. Phantoms composed of clinically relevant and tissue-equivalent materials (lung, bone, muscle, and adipose) were scanned with a commercial circular-scanning micro CT imager. This imaging system is composed with a micro-focused x-ray tube and charged-coupled device (CCD) camera as the detector. The mean CT numbers and the corresponding standard deviations in terms of Hounsfield units were then computed from a pre-defined region of interest located within the reconstructed volumetric images. The variations of CT number were then identified from a series of imaging parameters. Those parameters include imaging acquisition modes (e.g., the metal filter used in the x-ray tube), reconstruction methods (e.g., Feldkamp and iterative algorithm), and post-image processing techniques (e.g., ring artifact, beam-hardening artifact, and smoothing processing). These variations of CT numbers are useful and important in tissue characterization, quantitative bone structure analysis, bone marrow density evaluation, and Monte Carlo dose calculations for the pilot small animal study when micro CT imaging systems are employed. Also these variations can be used as the quantification for the performance of the micro CT imaging systems.

  16. Optimization of CT procedures

    International Nuclear Information System (INIS)

    Full text: In recent years computed tomography (CT) became a powerful diagnostic method. The technology advances in CT allowed improvement of the image quality, but set a number of challenges to all professionals working in the field of diagnostic imaging. CT capabilities expand, and thus increase the need for better training and qualification of staff and engineers responsible for the optimal functioning of the CT system. Despite the variety of technical innovations for dose reduction, obtaining of images with good diagnostic quality is often associated with increased dose. There is a lack of consensus in radiological practice about the use of contrast media and the image quality requirements. A common opinion is that the manufacturer setting is optimal. All this leads to large variations of doses for the same examinations and shows the need to optimize procedures. Learning objectives: optimization is not a single act but a process involving all the experts conducting the study. The presence of qualified medical physicist as a part of the team is important. Responsibility of the team is to choose which procedures have to be optimized. In most cases, the choice is between the most common procedures performed and those suspected in the diagnostic value of the image. Special attention should be paid to the study of children in order to exclude the use of protocols for adults, which leads to unnecessary high doses.each member of the team must be aware of the relationship between patient dose and image quality. the choice how to conduct the study depends on the diagnostic purpose. In some examinations, such as CT urography, obtaining high quality image at the cost of a higher dose does not improve the diagnostic outcome. On the other hand optimization is not necessarily associated with dose reduction. In cases where the images are not with adequate diagnostic quality, it is necessary to use a CT protocol with higher dose. Several international documents show the

  17. CT findings of automastoidectomy

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hyung Jin; Chung, Hae Gyeong; Kim, Jae Hyoung; Hwang, Eui Gee; Ma, Yong Woon; Chung, Sung Hoon [College of Medicine, Gyeongsang National University, Jinju (Korea, Republic of)

    1992-01-15

    Cholesteatoma of the middle ear and mastoid sometimes destroys the posterior wall of the external auditory canal(EAC), and this phenomenon is termed as 'automastoidectomy'. During the past two years the authors reviewed the CT features of automastoidectomy in eight patients with middle ear cholesteatoma, There was a variable amount of the cholesteatomatous mass or debris within the mastoid cavity in all patients, of whom air collection was found in four. Interestingly, the site and pattern of the erosion of the EAC were nearly identical between patients with air in the mastoid cavity and those without it. Air in the mastiod cavity was the only clue of the expulsion of the cholesteatoma. So, we think that the expulsion of the cholesteatoma might be predicted when the erosion of the EAC is present in patients with cholesteatoma in the mastoid cavity. CT clearly depicted associated complications caused by the cholesteatoma, such as ossicular destruction (n=8), the erosion of the facial nerve canal (n=2), the erosion of the lateral semicircular canal (n=2), the erosion of the tegmen (n=1), the erosion of the sigmoid sinus plate (n=1), the erosion of the superior semicircular canal (n=1), and the erosion of the vestibule (n=1). Although much of the natural history of the middle ear cholesteatoma still remains to be determined, we thick that careful evaluation of one type of possible progression of the disease will help us understand its clinical course. Moreover, our findings strongly support the use of CT for evaluation of 'automastoidectomy' seen in many cases of cholesteatoma.

  18. CT studies in hyperprolactinemia

    International Nuclear Information System (INIS)

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

  19. CT appearances of pleural tumours

    Energy Technology Data Exchange (ETDEWEB)

    Salahudeen, H.M. [Department of Radiology, Leeds Teaching Hospitals NHS Trust (United Kingdom)], E-mail: hmdsal@gmail.com; Hoey, E.T.D. [Department of Radiology, Leeds Teaching Hospitals NHS Trust (United Kingdom); Department of Radiology, Papworth Hospital, Cambridge (United Kingdom); Robertson, R.J.; Darby, M.J. [Department of Radiology, Leeds Teaching Hospitals NHS Trust (United Kingdom)

    2009-09-15

    Computed tomography (CT) is the imaging technique of choice for characterizing pleural masses with respect to their location, composition, and extent. CT also provides important information regarding invasion of the chest wall and surrounding structures. A spectrum of tumours can affect the pleura of which metastatic adenocarcinoma is the commonest cause of malignant pleural disease, while malignant mesothelioma is the most common primary pleural tumour. Certain CT features help differentiate benign from malignant processes. This pictorial review highlights the salient CT appearances of a range of tumours that may affect the pleura.

  20. Children, CT Scan and Radiation

    OpenAIRE

    Morteza Bajoghli; Farshad Bajoghli; Nazila Tayari; Reza Rouzbahani

    2010-01-01

    Children are more sensitive to radiation than adults. Computer-ized tomography (CT) consists of 25 % of all medical imaging. It was estimated that more than 2% of all carcinomas in the USA are due to CT scans. There is an ongoing focus on the reduction of CT scan radiation dose. Awareness about risk-benefits of CT has increased. Reduction of radiological exam is an important issue because the accumulation effects of radiation can be hazardous. In addition, proper protocol should be followed f...

  1. CT dosimetry and risk estimates

    International Nuclear Information System (INIS)

    Conventional approaches to CT dosimetry are inadequate because they fail to evaluate the risk to the patient. A risk related approach to CT dosimetry is developed which explicitly takes into account the non-uniform dose distribution in the body and the relative sensitivities of different organs and tissues. The principal radiological risks to patients undergoing CT examinations are the stochastic processes of carcinogenesis and genetic effects. Radiation risk estimates have been obtained for an EMI 5005 CT scanner by measuring the mean organ doses in a Rando phantom for CT studies on the head, chest, abdomen and pelvis. The application of these risk estimates to the population served by this CT scanner indicates that during the lifetime of the CT scanner, approximately 50,000 patients will undergo CT scanning and 60% will result in a positive diagnosis. The radiation detriment is estimated to be about 1 induced cancer and a negligible genetic effect. The radiation detriment is considerably smaller than the total detriment associated with contrast material used in 76% of the CT studies. (author)

  2. Practical pediatric abdominal CT

    International Nuclear Information System (INIS)

    This course is designed to help the radiologist in a hospital setting successfully approach abdominal CT in the infant and child. Emphasis is placed on techniques necessary for a high-quality examination of the upper abdomen, as applied to common pediatric problems such as trauma, tumor, and infection. Material is presented on technical considerations, including patient sedation, preparation, and potential pitfalls and helpful hints for imaging. An emphasis is placed on dynamic scanning with table incrementation. The section on trauma focuses on an approach to imaging the abdomen in the injured child, typical injuries, patterns of injury in the upper abdomen, and why CT is the best imaging modality for blunt upper abdominal trauma. The discussion of tumor imaging reviews the appearance of typical childhood neoplasia including Wilms tumor, neuroblastoma, non-Hodgkin and Burkitt lymphoma, and disseminated solid tumors such as rhabdomyosarcoma. The authors emphasize what to look for and where, both on initial and on later (for recurrences) examinations. The discussion of infection addresses detection of abscesses and occult infections in children, as well as imaging of abscesses prior to intervention

  3. CT in vascular pathologies

    Energy Technology Data Exchange (ETDEWEB)

    Bartolozzi, C.; Neri, E.; Caramella, D. [Diagnostic and Interventional Radiology Department of Oncology, University of Pisa, Via Roma 67, I-56100 Pisa (Italy)

    1998-06-02

    Since the introduction of helical scanners, CT angiography (CTA) has achieved an essential role in many vascular applications that were previously managed with conventional angiography. The performance of CTA is based on the accurate selection of collimation width, pitch, reconstruction spacing and scan delay, which must be modulated on the basis of the clinical issue. However, the major improvement of CT has been provided by the recent implementation of many post-processing techniques, such as multiplanar reformatting, shaded surface display, maximum intensity projections, 3D perspectives of surface and volume rendering, which simulate virtual intravascular endoscopy. The integration of the potentialities of the scanner and of the image processing techniques permitted improvement of: (a) the evaluation of aneurysms, dissection and vascular anomalies involving the thoracic aorta; (b) carotid artery stenosis; (c) aneurysms of abdominal aorta; (d) renal artery stenosis; (e) follow-up of renal artery stenting; and (f) acute or chronic pulmonary embolism. Our experience has shown that the assessment of arterial pathologies with CTA requires the integration of 3D post-processing techniques in most applications. (orig.) With 4 figs., 34 refs.

  4. A virtual spectral CT scanner

    International Nuclear Information System (INIS)

    Full text: Spectral computed tomography (sCT) brings a promise of improved tissue discrimination when compared to conventional CT. At the heart of this new technology are energy selective photon counting detectors (PCD) combined with theorics on how to select optimal energy bins for discriminating two or more materials. Several theories have been published on how to select these energy bins, but so far the diagnostic utility of optimised sCT has not been fully exploited. This work presents a first step towards a virtual sCT scanner based on the well bench marked BEAMnrc Monte Carlo code and the computer power of the University of Canterbury BlueFern supe computer. A computational model of a recently developed sCT scanner (MARS-CT) has been developed to produce virtual X-ray projection data through an imaging object. The energy and position of all transmitted photons impinging on the detector plane can be extracted without the additional complications introduced by non ideal behaviour (such as charge-sharing) of current detectors. The photons are grouped into selective energy bins to produce energy selective projection images of the imaging object (see Fig. I). This enables the comparison of conventional CT with optimised spectral CT. Furthermore, the virtual sCT scanner is an ideal tool to compare and evaluate the different theoretical models (which optimise different metrics) in terms of relevant clinical parameters such as image contrast. In further work we are planning to include the physical limitations of the detector so the virtual sCT scanner closely resembles the MARS CT scanner.

  5. CT of the skull base

    International Nuclear Information System (INIS)

    For the middle ear only the crus longus incudis and the stapedius still requires conventional tomography. This substitution of CT for classical tomography, welcome in itself is limited by financial considerations. However, when CT is necessary it should be done before tomography thus possibly limiting both expense and radiation dose. (orig./AJ)

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

    Science.gov (United States)

    ... not fit into the opening of a conventional CT scanner or may be over the weight limit—usually 450 pounds—for the moving table. Other imaging methods such as ultrasound or magnetic resonance (MR) imaging ... obtained by CT scanning. Working together, your primary care physician or ...

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

    Medline Plus

    Full Text Available ... image recording plate . Bones appear white on the x-ray; soft tissues show up in shades of gray and ... 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. Three-Section Expiratory CT:

    DEFF Research Database (Denmark)

    Loeve, Martine; de Bruijne, Marleen; Hartmann, Ieneke C. J.;

    2012-01-01

    Purpose: To estimate the effect of the number of computed tomography (CT) sections on trapped air (TA) assessment in patients with cystic fibrosis (CF) by using an established scoring system and a new quantitative scoring system and to compare CT and pulmonary function test (PFT) estimates of TA...

  9. Cardiac Computed Tomography (Multidetector CT, or MDCT)

    Science.gov (United States)

    ... Blood Pressure Tools & Resources Stroke More Cardiac Computed Tomography (Multidetector CT, or MDCT) Updated:Sep 3,2015 What is Computerized Tomography (CT)? CT is a noninvasive test that uses ...

  10. Preoperative assessment of vascular anatomy of inferior mesenteric artery by volume-rendered 3D-CT for laparoscopic lymph node dissection with left colic artery preservation in lower sigmoid and rectal cancer

    Institute of Scientific and Technical Information of China (English)

    Michiya Kobayashi; Satoshi Morishita; Takehiro Okabayashi; Kana Miyatake; Ken Okamoto; Tsutomu Namikawa; Yasuhiro Ogawa; Keijiro Araki

    2006-01-01

    AIM: To determine the distance between the branching point of the left colic artery (LCA) and the inferior mesenteric artery (IMA) by computed tomography (CT) scanning, for preoperative evaluation before laparoscopic colorectal operation.METHODS: From February 2004 to May 2005, 100patients (63 men, 37 women) underwent angiography performed with a 16-scanner multi-detector row CT unit (Toshiba, Aquilion 16). All images were analyzed on a workstation (AZE Ltd, Virtual Place Advance 300). The distance from the root of the IMA to the bifurcation of the LCA was measured by curved multi-planar reconstruction on a workstation.RESULTS: The IMA could be visualized in all the cases,but the LCA was missing in two patients. The mean distance from the root of the IMA to the root of the LCA was 42.0 mm (range, 23.2-75.0 mm). There were no differences in gender, arterial branching types, body weight, height, and body mass index.CONCLUSION: Volume-rendered 3D-CT is helpful to assess the vascular branching anatomy for laparoscopic surgery.

  11. Innovations in PET/CT

    DEFF Research Database (Denmark)

    Levin Klausen, T; Høgild Keller, S; Vinter Olesen, O;

    2012-01-01

    impressive anatomical details. PET/CT designs are facing many challenges such as the conversion of CT numbers to attenuation coefficients, giving rise to artefacts due to the presence of high Zeff material. Patient motion during scans degrades image quality and subsequent analysis, and is a challenge......There has been a longstanding interest in positron emission tomography (PET) in combination with computed tomography (CT). Mostly because of the lack of structural information in PET which makes it difficult to assess the precise location of tissue with metabolic uptake, whereas CT can provide...... especially as spatial resolution improves. Software based image fusion remains a complex issue outside the brain. State of the art image quality in a modern PET/CT system includes incorporation of point spread function (PSF) and time-of-flight (TOF) information into the reconstruction leading to the high...

  12. The stylohyoid chain: CT imaging

    Energy Technology Data Exchange (ETDEWEB)

    Uysal Ramadan, Selma, E-mail: uysalselma@yahoo.co [Department of Radiology, Ankara Training and Research Hospital, Ankara 06590 (Turkey); Goekharman, Dilek, E-mail: gokharman@ttnet.net.t [Department of Radiology, Ankara Training and Research Hospital, Ankara 06590 (Turkey); Kosar, Pinar, E-mail: pkosar@hotmail.co [Department of Radiology, Ankara Training and Research Hospital, Ankara 06590 (Turkey); Kacar, Mahmut, E-mail: mkacar1961@gamil.co [Department of Radiology, Ankara Training and Research Hospital, Ankara 06590 (Turkey); Kosar, Ugur, E-mail: ugurkosar@hotmail.co [Department of Radiology, Ankara Training and Research Hospital, Ankara 06590 (Turkey)

    2010-09-15

    We aimed in this report to discuss the embryology, anatomy, theories of ossification and symptoms, clinical presentation, and diagnosis of the stylohyoid chain (SHC) variations, together with the role of radiographs, computed tomography (CT) and three-dimensional (3D)-CT in showing these variations. Because CT/3D-CT additionally facilitates visualization of the entire SHC with different axes, it is the most valuable method for establishing the relationship between the SHC and the surrounding tissue. SHC variation can be discovered during CT performed for indications other than ossified SHC. It is important to diagnose whether or not the SHC is ossified, since one of the treatment procedures in ossified SHC is total excision. If the clinician and radiologist are aware of these variations observed in the SHC, patients with vague symptoms may be spared unnecessary investigations and may be properly diagnosed earlier.

  13. CT- and MR colonography

    DEFF Research Database (Denmark)

    Achiam, Michael Patrick; Bülow, Steffen; Rosenberg, J

    2002-01-01

    BACKGROUND: Colorectal cancer is the second most frequent cancer and adenomas are widely accepted as precursors to colorectal cancer. Diagnosis and removal of adenomas are recommended to reduce cancer incidence and mortality. The current diagnostic methods include sigmoidoscopy and colonoscopy...... in the supine and prone positions. Data are then downloaded to a workstation for post processing and image-analysis. RESULTS: Results have shown a high sensitivity and specificity for polyps > or = 10 mm, comparable to the sensitivity of conventional colonoscopy and superior to double contrast barium enema...... colonography. Future developments with the use of "intelligent" computers, better resolution and faster examinations will make CT and/or MR colonography realistic options to replace conventional diagnostic colonoscopy....

  14. Thoracic textilomas: CT findings

    International Nuclear Information System (INIS)

    Objective: the aim of this study was to analyze chest CT scans of patients with thoracic textiloma. Methods: this was a retrospective study of 16 patients (11 men and 5 women) with surgically confirmed thoracic textiloma. The chest CT scans of those patients were evaluated by two independent observers, and discordant results were resolved by consensus. Results: the majority (62.5%) of the textilomas were caused by previous heart surgery. The most common symptoms were chest pain (in 68.75%) and cough (in 56.25%). In all cases, the main tomographic finding was a mass with regular contours and borders that were well-defined or partially defined. Half of the textilomas occurred in the right hemithorax and half occurred in the left. The majority (56.25%) were located in the lower third of the lung. The diameter of the mass was ≤ 10 cm in 10 cases (62.5%) and > 10 cm in the remaining 6 cases (37.5%). Most (81.25%) of the textilomas were heterogeneous in density, with signs of calcification, gas, radiopaque marker, or sponge-like material. Peripheral expansion of the mass was observed in 12 (92.3%) of the 13 patients in whom a contrast agent was used. Intraoperatively, pleural involvement was observed in 14 cases (87.5%) and pericardial involvement was observed in 2 (12.5%). Conclusions: it is important to recognize the main tomographic aspects of thoracic textilomas in order to include this possibility in the differential diagnosis of chest pain and cough in patients with a history of heart or thoracic surgery, thus promoting the early identification and treatment of this postoperative complication. (author)

  15. Holoprosencephaly and CT

    Energy Technology Data Exchange (ETDEWEB)

    Asada, M.; Tamaki, N.; Ebara, K.; Shirakuni, T.; Yamashita, H. (Kobe Univ. (Japan). School of Medicine)

    1981-02-01

    Holoprosencephaly, so termed by DeMyer, is a cerebral malformation in which the prosencephalon fails to divide into cerebral hemispheres early in fetal life. According to the degree of division in the prosencephalon and the presence of the associated facial anomalies, he classified holoprosencephaly into three types; alobar, semilobar, and lobar. We have had experience with six cases with holoprosencephaly: one alobar, one semilobar, and four lobar. No significant facial abnormalities were found in any case, but one had hyperterolism. All cases had hydrocephalus and had undergone an operation for a ventriculo-peritoneal shunt. The outcome of the shunt operation in two cases with alobar and semilobar holoprosencephaly was miserable. On the other hand, the cases with lobar type showed a fairly good prognosis. They were only mildly mentally retarded on a follow-up examination. It seemed, therefore, that the ventriculo-peritoneal shunt is indicated for this lobar type of holoprosencephaly. For this reason, it is important to make a precise diagnosis before any shunt operation. CT is a useful and safe diagnostic procedure for evaluating the intracranial structures of holoprosencephaly: the degree of division in the prosencephalon, the ventricular configuration, the dorsal sac, and the absence of falx. When the hydrocephalus associated with this disease is severe, the interhemispheric fissure is not clearly delineated, and it may sometimes be difficult to differentiate the semilobar from the lobar type of holoprosencephaly. The course of the azygos anterior cerebral artery on angiograms is useful in distinguishing one from the other. It is hoped that a multi-directional approach on CT will reveal a more precise structure of holoprosencephaly and that a definitive diagnosis can be made without angiography or other invasive procedures.

  16. Thoracic textilomas: CT findings

    Energy Technology Data Exchange (ETDEWEB)

    Machado, Dianne Melo; Zanetti, Glaucia; Araujo Neto, Cesar Augusto; Nobre, Luiz Felipe; Meirelles, Gustavo de Souza Portes; Silva, Jorge Luiz Pereira e; Guimaraes, Marcos Duarte; Escuissato, Dante Luiz; Souza Junior, Arthur Soares; Hochhegger, Bruno; Marchiori, Edson, E-mail: edmarchiori@gmail.com [Hospital Universitario Antonio Pedro (HUAP/UFF), Niteroi, RJ (Brazil)

    2014-09-15

    Objective: the aim of this study was to analyze chest CT scans of patients with thoracic textiloma. Methods: this was a retrospective study of 16 patients (11 men and 5 women) with surgically confirmed thoracic textiloma. The chest CT scans of those patients were evaluated by two independent observers, and discordant results were resolved by consensus. Results: the majority (62.5%) of the textilomas were caused by previous heart surgery. The most common symptoms were chest pain (in 68.75%) and cough (in 56.25%). In all cases, the main tomographic finding was a mass with regular contours and borders that were well-defined or partially defined. Half of the textilomas occurred in the right hemithorax and half occurred in the left. The majority (56.25%) were located in the lower third of the lung. The diameter of the mass was ≤ 10 cm in 10 cases (62.5%) and > 10 cm in the remaining 6 cases (37.5%). Most (81.25%) of the textilomas were heterogeneous in density, with signs of calcification, gas, radiopaque marker, or sponge-like material. Peripheral expansion of the mass was observed in 12 (92.3%) of the 13 patients in whom a contrast agent was used. Intraoperatively, pleural involvement was observed in 14 cases (87.5%) and pericardial involvement was observed in 2 (12.5%). Conclusions: it is important to recognize the main tomographic aspects of thoracic textilomas in order to include this possibility in the differential diagnosis of chest pain and cough in patients with a history of heart or thoracic surgery, thus promoting the early identification and treatment of this postoperative complication. (author)

  17. Role of multi-detector computed tomography (MDCT in management of post percutaneous nephrolithotomy (PCNL bleeding [v1; ref status: indexed, http://f1000r.es/205

    Directory of Open Access Journals (Sweden)

    Arvind P Ganpule

    2013-11-01

    Full Text Available Objective: To evaluate the role of multidetector computerized tomography (MDCT angiography in post percutaneous nephrolithotomy (PCNL bleed and compare findings with conventional angiography (CA. Material and methods: We conducted a retrospective analysis of patients who had post PCNL bleeding and subsequently underwent a MDCT angiography followed by CA. We reviewed eight patients, who presented between January 2009 and January 2013. We performed a MDCT angiography on a 16 slice GE bright speed CT scanner. All angiographies were done by using the Digital Subtraction Angiography Suite. The angioembolisation, if required, was conducted by an interventional nephrologist, specializing in therapeutic embolisation. Results: The mean age of the patients was 42±17 years. Mean time of post PCNL bleed presentation was 10.06±7.9 days. Five patients presented with aneurysm and three presented with an AV fistula with pseudoaneurysm. The right renal unit was involved in six cases and the left in two cases. The lower polar segmental artery was involved in six cases and the upper polar artery in two cases. The CA and MDCT findings matched in all cases and the MDCT helped the clinician to assess and embolise the appropriate arterial tree. Conclusion: MDCT is rapid, reproducible and noninvasive. MDCT angiography performed in the setting of post PCNL bleeding provides an accurate assessment of the site and nature of bleeding. The MDCT angiography matched the CA findings in all patients in the present study.

  18. Optimization of Protocol CT, PET-CT, whole body

    International Nuclear Information System (INIS)

    The objective of this study was to optimize the acquisition protocols and processing existing of the CT PET/CT scanner for clinical use of Nuclear Diagnostic Center Foundation, a way to minimize the radiation dose while maintaining diagnostic image quality properly. Dosimetric data of PET / CT service were surveyed and obtained the baseline against which we compare and define strategies and modifications to develop online. We selected transaxial up to the pulmonary hilum and liver slices as the anatomical regions of interest that led to the standardization of the study

  19. 高灵敏度探测器结合迭代重建在低管电压冠状动脉CT血管成像的价值%Radiation dose reduction of coronary CT angiography at low tube voltage on an integrated circuit detector with iterative reconstruction

    Institute of Scientific and Technical Information of China (English)

    王怡宁; 曹剑; 孔令燕; 林路; 薛华丹; 李烁; 宋兰; 王志伟; 周慷

    2014-01-01

    Objective To investigate the value of low tube voltage (80 kV) for coronary computed tomography angiography (CCTA) in patients with normal body mass index (BMI) on 128-slice dual-source CT with novel high sensitive integrated circuit (IC) detector.Methods One hundred and three consecutive patients were scanned using prospectively ECG-triggered sequential CCTA protocol.All patients were randomly divided into group A and B.Group A was examined on a conventional 128-slice dual-source CT,while group B on a 128-slice dual-source CT with high sensitive integrated circuit detector.The tube voltage of group A was 100 kV and raw data was reconstructed with filtered back projection (FBP),while tube voltage of group B was 80 kV and raw data was reconstructed with both FBP (Subgroup B1) and sonogramaffirmed iterative reconstruction (SAFIRE) (Subgroup B2).The differences in background noise,signal-tonoise ratio (SNR),contrast-to-noise ratio (CNR),CT dose index volume (CTDIvol),effective dose (ED),and image quality between the groups were compared by using t test,ANOVA and x2 test.Results There were no significant differences in age,BMI or heart rate between the two groups (Group A,n =52 vs.Group B,n =51).Radiation exposure (CTDIvol and ED) of group B was significantly lower than that of group A [(8.93 ±2.55) vs.(13.87 ±4.62) mGy and (1.77 ±0.51)vs.(2.65 ±0.89) mSv,t =6.71,6.09,all P < 0.01].SNR and CNR of proximal coronary arteries in group B2 were significantly higher than group A and B1,and there was no significant difference between the latter two.In group A,mean score of total 839 coronary artery segments was 1.29 ± 0.23,and the number of evaluable segments was 813 (96.9%).In group B1,mean score of total 820 coronary artery segments was 1.34 ± 0.29,and the number of evaluable segments was 789 (96.2%).In group B2,mean score of total 820 coronary artery segments was 1.33 ± 0.31,and the number of was 791 (96.5%).There were no significant differences in both mean

  20. Dose coefficients in pediatric and adult abdominopelvic CT based on 100 patient models

    Science.gov (United States)

    Tian, Xiaoyu; Li, Xiang; Segars, W. Paul; Frush, Donald P.; Paulson, Erik K.; Samei, Ehsan

    2013-12-01

    Recent studies have shown the feasibility of estimating patient dose from a CT exam using CTDIvol-normalized-organ dose (denoted as h), DLP-normalized-effective dose (denoted as k), and DLP-normalized-risk index (denoted as q). However, previous studies were limited to a small number of phantom models. The purpose of this work was to provide dose coefficients (h, k, and q) across a large number of computational models covering a broad range of patient anatomy, age, size percentile, and gender. The study consisted of 100 patient computer models (age range, 0 to 78 y.o.; weight range, 2-180 kg) including 42 pediatric models (age range, 0 to 16 y.o.; weight range, 2-80 kg) and 58 adult models (age range, 18 to 78 y.o.; weight range, 57-180 kg). Multi-detector array CT scanners from two commercial manufacturers (LightSpeed VCT, GE Healthcare; SOMATOM Definition Flash, Siemens Healthcare) were included. A previously-validated Monte Carlo program was used to simulate organ dose for each patient model and each scanner, from which h, k, and q were derived. The relationships between h, k, and q and patient characteristics (size, age, and gender) were ascertained. The differences in conversion coefficients across the scanners were further characterized. CTDIvol-normalized-organ dose (h) showed an exponential decrease with increasing patient size. For organs within the image coverage, the average differences of h across scanners were less than 15%. That value increased to 29% for organs on the periphery or outside the image coverage, and to 8% for distributed organs, respectively. The DLP-normalized-effective dose (k) decreased exponentially with increasing patient size. For a given gender, the DLP-normalized-risk index (q) showed an exponential decrease with both increasing patient size and patient age. The average differences in k and q across scanners were 8% and 10%, respectively. This study demonstrated that the knowledge of patient information and CTDIvol/DLP values may

  1. Optimization of Protocol CT, PET-CT, whole body; Optimizacion de protocolo CT, en PET-CT, de cuerpo entero

    Energy Technology Data Exchange (ETDEWEB)

    Gutierrez, Fredys Santos, E-mail: fsantos@ccss.sa.cr [Caja Costarricense de Seguro Social (ACCPR/CCSS), San Jose (Costa Rica). Area Control de Calidade Y Proteccion Radiologica; Namias, Mauro, E-mail: mnamias@gmail.com [Comision Nacional de Energia Atomica (FCDN/CNEA), Buenos Aires (Argentina). Fundacion Centro Diagnostico Nuclear

    2013-11-01

    The objective of this study was to optimize the acquisition protocols and processing existing of the CT PET/CT scanner for clinical use of Nuclear Diagnostic Center Foundation, a way to minimize the radiation dose while maintaining diagnostic image quality properly. Dosimetric data of PET / CT service were surveyed and obtained the baseline against which we compare and define strategies and modifications to develop online. We selected transaxial up to the pulmonary hilum and liver slices as the anatomical regions of interest that led to the standardization of the study.

  2. CT features of retroperitoneal neurilemmoma

    Energy Technology Data Exchange (ETDEWEB)

    Kinoshita, T.; Ishii, K. [Department of Radiology, Sendai City Hospital, 3-1 Shimizukouji, Wakabayashi-ku Sendai 984 (Japan); Naganuma, H. [Department of Pathology, Sendai City Hospital, 3-1 Shimizukouji, Wakabayashi-ku, Sendai 984 (Japan); Itoh, H. [Department of Radiology, Miyagi Prefectural Semine Hospital, 55-2 Funegishi, Semine 989-45 (Japan)

    1998-03-01

    Purpose: The aim of this study was to characterize the CT features of retroperitoneal neurilemmoma. Methods: The CT findings were reviewed in seven patients with retroperitoneal neurilemmoma. Results: All of the tumours were well-demarcated round or oval masses. In five cases, heterogeneous contrast enhancement was noted after contrast medium administration. Areas of minimal enhancement reflected diffuse edema in one tumour. Areas without definite enhancement represented prominent cyst formation in three tumours. There were three cases with tumour calcification (two with punctate calcification and one with mottled calcification). Conclusion: CT findings may suggest the diagnosis of retroperitoneal neurilemmoma preoperatively. (Copyright (c) 1998 Elsevier Science B.V., Amsterdam. All rights reserved.)

  3. CT perfusion in acute stroke

    International Nuclear Information System (INIS)

    Stroke is a heterogeneous syndrome caused by multiple mechanisms, all of which result in disruption of normal cerebral blood flow and thereby cause cerebral dysfunction. Its early diagnosis is important as its treatment is dependent on the time elapsed since ictus. Delay in diagnosis and treatment translates into increase neuronal loss and thereby increased morbidity. CT scan, and in particular perfusion CT, has helped greatly in the early diagnosis of stroke. This article is an endeavor to explain the pathophysiology of cerebral ischemia and the role of CT perfusion in detecting it

  4. Targeted dual-energy single-source CT for characterisation of urinary calculi: experimental and clinical experience

    Energy Technology Data Exchange (ETDEWEB)

    Eiber, Matthias; Holzapfel, Konstantin; Rummeny, Ernst J.; Dobritz, Martin; Huber, Armin [Technische Universitaet Muenchen, Institute of Radiology, Klinikum rechts der Isar, Munich (Germany); Frimberger, Markus; Straub, Michael [Technische Universitaet Muenchen, Department of Urology, Munich (Germany); Schneider, Heike [Technische Universitaet Muenchen, Institute of Clinical Chemistry and Pathobiochemistry, Munich (Germany)

    2012-01-15

    To assess the accuracy of targeted dual-energy single-source multi-detector CT (MDCT) for characterisation of urinary calculi. For proof of principle, 71 ex-vivo calculi underwent single-source 256-slice MDCT. Low-dose CT was performed in 154 patients with suspected urinary calculi. In 104 patients with urinary calculi targeted dual-energy imaging within one breath-hold was added. 46 patients with sufficient material for infrared-spectroscopy were analysed. Potential anatomical misregistrations between 80- and 140-kV{sub p}-images and HU-values were measured. DEIs (dual-energy-indices) were compared with the standard of reference. Effective doses were calculated. In 26 of 46 patients no misregistration was present. Mean deviations were 2.7 mm in the z-axis (16 patients) and 4.3 mm in the axial plane (10 patients). The DEIs were 0.018 {+-} 0.016 for uric acid (UA), 0.035 {+-} 0.015 for mixed UA and 0.102 {+-} 0.015 for calcified stones in-vitro and 0.017 {+-} 0.002 for UA, 0.050 {+-} 0.019 for mixed UA and 0.122 {+-} 0.024 for calcified calculi in-vivo. Significant differences were noted among calcium, mixed UA and UA stones (p < 0.05). For the low-dose examination mean effective dose was 3.11 mSv. Targeted dual-energy resulted in an extra dose of 1.84 mSv (additional 59.1%). Targeted dual-energy imaging within one breath-hold is feasible for characterisation of urinary calculi using single-source MDCT allowing minimal anatomical discordance. (orig.)

  5. Size-based emphysema cluster analysis on low attenuation area in 3D volumetric CT: comparison with pulmonary functional test

    Science.gov (United States)

    Lee, Minho; Kim, Namkug; Lee, Sang Min; Seo, Joon Beom; Oh, Sang Young

    2015-03-01

    To quantify low attenuation area (LAA) of emphysematous regions according to cluster size in 3D volumetric CT data of chronic obstructive pulmonary disease (COPD) patients and to compare these indices with their pulmonary functional test (PFT). Sixty patients with COPD were scanned by a more than 16-multi detector row CT scanner (Siemens Sensation 16 and 64) within 0.75mm collimation. Based on these LAA masks, a length scale analysis to estimate each emphysema LAA's size was performed as follows. At first, Gaussian low pass filter from 30mm to 1mm kernel size with 1mm interval on the mask was performed from large to small size, iteratively. Centroid voxels resistant to the each filter were selected and dilated by the size of the kernel, which was regarded as the specific size emphysema mask. The slopes of area and number of size based LAA (slope of semi-log plot) were analyzed and compared with PFT. PFT parameters including DLco, FEV1, and FEV1/FVC were significantly (all p-value< 0.002) correlated with the slopes (r-values; -0.73, 0.54, 0.69, respectively) and EI (r-values; -0.84, -0.60, -0.68, respectively). In addition, the D independently contributed regression for FEV1 and FEV1/FVC (adjust R sq. of regression study: EI only, 0.70, 0.45; EI and D, 0.71, 0.51, respectively). By the size based LAA segmentation and analysis, we evaluated the Ds of area, number, and distribution of size based LAA, which would be independent factors for predictor of PFT parameters.

  6. Intracranial tuberculoma: CT and MRI

    International Nuclear Information System (INIS)

    The appearances of intracranial tuberculoma on CT and MRI are described. Eight patients (6 males and 2 females) with intracranial tuberculomas studied over the past 4 years are presented. Four patients had AIDS and among the four non-AIDS patients 1 had undergone hepatic transplantation. All the cases were studied with CT and 6 underwent MRI. Five lesions were infratentorial, and 2 patients had double lesions. In 2 patients obstructive triventricular hydrocephalus was present. No patient had meningeal involvement. The stage of evolution was cerebritis in 1 case, incipient tuberculoma in 3 cases, mature tuberculoma in 1 case and tuberculous abscess in 5 cases. Diagnosis of intracranial tuberculoma was determined histologically in 5 patients and by good response to specific therapy in the remaining patients. Although CT allows differentiation between incipient and mature tuberculoma, MRI allows a better determination of the evolutonary stage. In most cases combined CT and MRI examinations provide an accurate diagnosis of intracranial tuberculoma. (orig.)

  7. Intracranial tuberculoma: CT and MRI

    Energy Technology Data Exchange (ETDEWEB)

    Bargallo, N. [Dept. of Radiology, Hospital Clinic i Provincial de Barcelona (Spain); Berenguer, J. [Dept. of Radiology, Hospital Clinic i Provincial de Barcelona (Spain); Tomas, X. [Dept. of Radiology, Hospital Clinic i Provincial de Barcelona (Spain); Nicolau, C. [Dept. of Radiology, Hospital Clinic i Provincial de Barcelona (Spain); Cardenal, C. [Dept. of Radiology, Hospital Clinic i Provincial de Barcelona (Spain); Mercader, J.M. [Dept. of Radiology, Hospital Clinic i Provincial de Barcelona (Spain)

    1993-04-01

    The appearances of intracranial tuberculoma on CT and MRI are described. Eight patients (6 males and 2 females) with intracranial tuberculomas studied over the past 4 years are presented. Four patients had AIDS and among the four non-AIDS patients 1 had undergone hepatic transplantation. All the cases were studied with CT and 6 underwent MRI. Five lesions were infratentorial, and 2 patients had double lesions. In 2 patients obstructive triventricular hydrocephalus was present. No patient had meningeal involvement. The stage of evolution was cerebritis in 1 case, incipient tuberculoma in 3 cases, mature tuberculoma in 1 case and tuberculous abscess in 5 cases. Diagnosis of intracranial tuberculoma was determined histologically in 5 patients and by good response to specific therapy in the remaining patients. Although CT allows differentiation between incipient and mature tuberculoma, MRI allows a better determination of the evolutonary stage. In most cases combined CT and MRI examinations provide an accurate diagnosis of intracranial tuberculoma. (orig.)

  8. Multiplanar CT of the spine

    Energy Technology Data Exchange (ETDEWEB)

    Rothman, S.L.G.; Glenn, W.V. Jr.

    1986-01-01

    This is an illustrated text on computed tomography (CT) of the lumbar spine with an emphasis on the role and value of multiplanar imaging for helping determine diagnoses. The book has adequate discussion of scanning techniques for the different regions, interpretations of various abnormalities, degenerative disk disease, and different diagnoses. There is a 50-page chapter on detailed sectional anatomy of the spine and useful chapters on the postoperative spine and the planning and performing of spinal surgery with CT multiplanar reconstruction. There are comprehensive chapters on spinal tumors and trauma. The final two chapters of the book are devoted to CT image processing using digital networks and CT applications of medical computer graphics.

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

    Medline Plus

    Full Text Available ... particularly the lungs, abdomen, pelvis and bones. Sometimes ultrasound is substituted for CT as a method of ... to consider other tests, such as MRI or ultrasound which might give the same information. Other measures ...

  10. Children, CT scan and radiation

    Directory of Open Access Journals (Sweden)

    Morteza Bajoghli

    2010-01-01

    Full Text Available Children are more sensitive to radiation than adults. Computer-ized tomography (CT consists of 25 % of all medical imaging. It was estimated that more than 2% of all carcinomas in the USA are due to CT scans. There is an ongoing focus on the reduction of CT scan radiation dose. Awareness about risk-benefits of CT has increased. Reduction of radiological exam is an important issue because the accumulation effects of radiation can be hazardous. In addition, proper protocol should be followed for diagnostic pro-cedures of ionization radiation and computerized tomography. Effective radiation dose should range from 0.8 to 10.5 millisievert. The same protocol should be followed in different hospitals as well. Basic principles of radiation protection should be monitored. As much as possible, both technician and radiologist must be pre-sent during computerized tomography for children, and MRI and ultrasound should be replaced if possible.

  11. Multiple myeloma: evaluation by CT

    International Nuclear Information System (INIS)

    Although patients who have multiple myeloma usually have straightforward clinical symptoms and corroborative radiographs, in some instances, these patients will present atypically, with symptoms suggesting active disease but radiographs that are normal or nonspecific. The authors reviewed the records of 32 patients who had documented multiple myeloma and had undergone CT examinations, assessing the value of those examinations. Although CT is not indicated in all patients who have multiple myeloma, it is especially useful in patients who have bone pain and normal or nonspecific radiographs. CT provided confirmatory information in all cases in which lesions were seen on radiographs. CT also frequently demonstrated a greater extent of disease than could be appreciated on the radiographs

  12. Principles of viewing in CT

    International Nuclear Information System (INIS)

    Colour CT should not be routinely used but be reserved for certain cases presenting difficulties of interpretation and for certain types of images. However, side by side viewing in monochrome and colour is of considerable diagnostic interest. (orig./AJ)

  13. Your Radiologist Explains CT Colonography

    Medline Plus

    Full Text Available ... Pediatric Ultrasound Video: Angioplasty & vascular stenting Video: Arthrography Radiology and You About this Site RadiologyInfo.org is ... Explains CT Colonography (Virtual colonoscopy) Transcript Welcome to Radiology Info dot org! Hi, I’m Dr. Elliot ...

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

    Medline Plus

    Full Text Available ... create detailed images of your child’s internal organs, bones, soft tissues and blood vessels. It may be ... CD or DVD. CT images of internal organs, bones, soft tissue and blood vessels typically provide greater ...

  15. CT findings of muscular dystrophy

    International Nuclear Information System (INIS)

    CT scans of muscles in patients with limb girdle type (LG), myotonic type (MYD) and Duchenne type (DMD) dystrophies were obtained at five different body levels: the neck, L3 vertebral body, pelvic girdle, thigh and lower leg. CT numbers, cross sectional areas (CSA) and %CSA of muscle or fat were evaluated in each muscle. The characteristic CT patterns for each type of muscular dystrophy were obtained. Compared with DMD, the gracilis and soleus were more severely damaged in LG and the biceps femoris remained relatively preserved among the hamstrings. In addition, the multifidus of the neck and sternocleidomastoid also were more severely damaged in MYD. This study suggests that CT scan will be useful in the differential diagnosis of these types of muscular dystrophy as well as in planning appropriate rehabilitation and detecting damaged muscles. (author)

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

    Medline Plus

    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, ...

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

    Medline Plus

    Full Text Available ... a CT or CAT scan, is a diagnostic medical test that, like traditional x-rays, produces multiple ... your doctor of any recent illnesses or other medical conditions your child may have, and if there ...

  18. Your Radiologist Explains CT Colonography

    Medline Plus

    Full Text Available ... this Site RadiologyInfo.org is produced by: Image/Video Gallery Your Radiologist Explains CT Colonography (Virtual colonoscopy) ... Recently posted: Focused Ultrasound for Uterine Fibroids Dementia Video: General Ultrasound Video: Pediatric Nuclear Medicine Radiology and ...

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

    Medline Plus

    Full Text Available ... pain, evaluate for injury after trauma, diagnose and stage cancer, monitor response to treatment for cancer, and ... possible and to "fine tune" the CT settings based on the reason for the exam, the body ...

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

    Medline Plus

    Full Text Available ... scanner. top of page How does the procedure work? In many ways, CT scanning is like other ... instructions on any limitations in activity for the day. top of page Who interprets the results and ...

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

    Medline Plus

    Full Text Available ... view of the body's interior. Refinements in detector technology allow new CT scanners to obtain multiple slices ... the need for sedation and general anesthesia. New technologies that will make even faster scanning possible are ...

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

    Medline Plus

    Full Text Available ... vessels. CT examinations are fast and simple; in emergency cases, they can reveal internal injuries and bleeding ... and the child's size. Radiologists generally attempt to use the lowest radiation dose that will provide the ...

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

    Medline Plus

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

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

    Medline Plus

    Full Text Available ... over time. top of page What are the benefits vs. risks? Benefits Using a multidetector CT unit to examine children ... that will provide the needed diagnostic information. The benefit of an accurate diagnosis far outweighs the risk. ...

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

    Medline Plus

    Full Text Available ... over time. top of page What are the benefits vs. risks? Benefits Using a multidetector CT unit to examine children ... the possible charges you will incur. Web page review process: This Web page is reviewed regularly by ...

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

    Medline Plus

    Full Text Available ... internal organs, bones, soft tissues and blood vessels. It may be used to help diagnose abdominal pain ... evaluate blood vessels throughout the body. With CT, it is possible to obtain very detailed pictures of ...

  7. Comparison of two accelerators for Monte Carlo radiation transport calculations, Nvidia Tesla M2090 GPU and Intel Xeon Phi 5110p coprocessor: A case study for X-ray CT imaging dose calculation

    International Nuclear Information System (INIS)

    Highlights: • A new Monte Carlo photon transport code ARCHER-CT for CT dose calculations is developed to execute on the GPU and coprocessor. • ARCHER-CT is verified against MCNP. • The GPU code on an Nvidia M2090 GPU is 5.15–5.81 times faster than the parallel CPU code on an Intel X5650 6-core CPU. • The coprocessor code on an Intel Xeon Phi 5110p coprocessor is 3.30–3.38 times faster than the CPU code. - Abstract: Hardware accelerators are currently becoming increasingly important in boosting high performance computing systems. In this study, we tested the performance of two accelerator models, Nvidia Tesla M2090 GPU and Intel Xeon Phi 5110p coprocessor, using a new Monte Carlo photon transport package called ARCHER-CT we have developed for fast CT imaging dose calculation. The package contains three components, ARCHER-CTCPU, ARCHER-CTGPU and ARCHER-CTCOP designed to be run on the multi-core CPU, GPU and coprocessor architectures respectively. A detailed GE LightSpeed Multi-Detector Computed Tomography (MDCT) scanner model and a family of voxel patient phantoms are included in the code to calculate absorbed dose to radiosensitive organs under user-specified scan protocols. The results from ARCHER agree well with those from the production code Monte Carlo N-Particle eXtended (MCNPX). It is found that all the code components are significantly faster than the parallel MCNPX run on 12 MPI processes, and that the GPU and coprocessor codes are 5.15–5.81 and 3.30–3.38 times faster than the parallel ARCHER-CTCPU, respectively. The M2090 GPU performs better than the 5110p coprocessor in our specific test. Besides, the heterogeneous computation mode in which the CPU and the hardware accelerator work concurrently can increase the overall performance by 13–18%

  8. CT findings of necrotizing jejunitis

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Pyo Nyun; Lee, Kyung Soo; Bae, Won Kyung; Kim, Il Young; Lee, Byoung Ho [College of Medicine, Soonchunhyang Univ., Chunan (Korea, Republic of)

    1990-07-15

    Necrotizing enterocolitis, which is localized only in the jejunum, is very rare and this entity cannot be found in the English medical literature. We report the computed tomographic(CT) findings of necrotizing jejunitis in a 45-year-old man, which showed ring like and mottled air shadows between the contrast filled bowel lumen and its wall, dirty mesenteric fat and prominent mesenteric vascular enhancement. We regard CT is a useful diagnostic method of necrotizing jejunitis.

  9. CT anatomy of the spine

    International Nuclear Information System (INIS)

    Effective CT scanning of the spine requires gantry opening greater than 50 cm, spatial resolution of less than 1 mm, contrast resolution of better than 0.5%, and a method for exact localization and selection of cut levels. With a suitable scanner, excellent images of the intervertebral disc, dural sac, spinal cord, facet joints, ligamentum flavum, and epidural veins can be obtained. The purpose of this report is to describe the normal CT appearance of the spinal soft tissues. (orig.)

  10. CT imaging of the pancreas

    International Nuclear Information System (INIS)

    Full text: Introduction: CT is the method of choice for differential and preoperative diagnosis of the pancreatic diseases. This presentation will be presented main CT imaging characteristics of the most common pancreatic diseases, as well as the advantages, disadvantages and indications for conducting of a computer imaging study of the pancreatic diseases. What you will learn: To know and to describe the main nosological units ( tumors and pancreatitis) affecting the pancreas; How to distinguish benign from malignant lesions of the pancreas; To know benign pancreatic diseases that mimic malignancy; Advantages and limitations of CT in diagnosing of the pancreatic diseases, Correctly interpretation and clear description of imaging findings in pancreatic diseases for the purposes of subsequent conservative or surgery treatment, To assess the need to carry out further research and control studies. Discussion: CT study makes possible the presentation of the feature density structure, limits and the contrasting of pathological changes in the pancreas, their anatomical position in it and the position toward the neighboring structures. CT provides information for the vascularisation of the described lesions by the mode of change in the post-contrast stenograms density. CT is an indispensable method for preoperative assessment of the anatomical course of blood vessels and vascular invasion in tumor diseases. CT is a valuable tool in the differential diagnosis between solid malignant (adenocarcinoma, neuroendocrine tumors, lymphoma, metastasis) and benign nosological entities such as certain forms of pancreatitis (autoimmune, paraduodenal) between benign and malignant pancreatic cystic lesions, etc. Conclusion: CT is an essential method in the diagnostic algorithm of pancreatic diseases due to continuous improvement and the possibility to meet the ever more questions in one-step assay

  11. CT manifestations of ileal dysgenesis

    Energy Technology Data Exchange (ETDEWEB)

    Oberhelman, Amy P.; Herman, Thomas E.; McAlister, William H. [St. Louis Children' s Hospital, Mallinckrodt Institute of Radiology, Washington University School of Medicine, Department of Radiology, St. Louis, MO (United States); Keating, James P. [St. Louis Children' s Hospital, Mallinckrodt Department of Pediatrics, Washington University School of Medicine, Division of Gastroenterology, St. Louis, MO (United States); Rollins, Michael D.; Dillon, Patrick A. [St. Louis Children' s Hospital, Department of Surgery, Washington University School of Medicine, St. Louis, MO (United States)

    2007-02-15

    Ileal dysgenesis is an uncommon condition of unknown etiology occurring in the distal ileum in the region of the vitelline duct. The CT appearance of this lesion, although not previously described to our knowledge, is characteristic. We report a patient with ileal dysgenesis who had an abdominal CT scan to evaluate chronic iron deficiency anemia and protein-losing enteropathy. Recognition of this lesion by pediatric radiologists is important; so that surgical treatment, which is simple and effective, can be initiated quickly. (orig.)

  12. Necessity and clinical application of diagnostic CT in PET-CT scanner

    International Nuclear Information System (INIS)

    PET scanning has a definite clinical impact on diagnosis, initial staging, restaging, monitoring therapeutic effects of malignancies, and on assessment of myocardial viability. Whereas, PET scans has false positive diagnosis and false negative diagnosis of malignant lesions. It leads to reduce specifity in PET imaging. application of diagnostic CT, especially applying contrast enhanced CT scans, three dimensional technique, CTA(CT angiography), CT perfusion and CT virtual endoscopy can realize dominance complementation with PET and CT, PET-CT imaging diagnosis combines with PET and CT diagnostic technique, it improves sensitivity, specifity, and accuracy in clinical application of PET-CT scanner. (authors)

  13. Application of 256 Multi-Detector Computed Tomography Enterography in Small Bowel Inflammatory Diseases%256层多排螺旋CT小肠成像对小肠炎症性病变的临床应用研究

    Institute of Scientific and Technical Information of China (English)

    解骞; 窦娅芳; 梁宗辉; 朱全东; 祝瑞江

    2013-01-01

    To discuss the utility of MDCTE for evaluating inflammatory diseases of the small bowel. Materials and methods: At our institution, 118 patients (male 53; female 65; mean age 48.5 years) with symptoms of suspected small bowel diseases underwent 256-MDCTE. Pertinent MDCTE and histopathology reports were reviewed. The CT appearances characteristic of small-bowel inflammatory bowel disease are described and illustrated in detail. Associated complications and extraenteric manifestations also are described. Results: Of 118 MDCTEs performed, there were 25 cases of small bowel inflammations (male 13; female 12; mean age 45.5 years). In all 12 cases of Crohn's diseases, small bowel involvement was typically transmural, with characteristic skip lesions. CT features of active Crohn^s disease include mucosal hyper-enhancement, irregular wall thickening, mural stratification with a prominent vasa recta (comb sign), and mesenteric fat stranding. 2 cases of ulceratiiwe colitis characterized by a continuous pattern of bowel wall involvement, starting from the rectum, without evidence of skip lesions. Ulcerative colitis predominantly involved the large bowel but may extend to the terminal ileum. Extra-intestinal manifestations may occur but were uncommon. Mucosal hyper-enhancement along with circumferential and symmetric boweli wall thickening was- present. There was mural stratification witto enhancement of the inner mucosa and outer muscularis propria. Mesenteric hyperemia was present in the pericolonic fat; MDCTE demonstrated findings suggestive of intestinal tuberculosis in one patient by depicting ulcero-nodular with strictures, edema and thickening of the ileocecal region, the presence of neexotic mesenteric lymph nodes that were adjacent to a small-bowel thickening; There-was 1 case of viral gastroenteritis and 7 cases of generalized small bowel enteritis withsnon-specific MDCTE features include bowej thickening and submucosai edema appreciable in the entire intestine

  14. CT findings of Japanese encephalitis

    Energy Technology Data Exchange (ETDEWEB)

    Shoji, Hiroshi; Toyomasu, Teruo; Fukada, Makiko; Nakashima, Kenichi; Kaji, Masaro; Kobayashi, Kenji

    1984-04-01

    In this study, CT findings of eight patients with Japanese encephalitis were analyzed. In principle, CT scans were done at the acute stage, within 3 weeks of the onset, and at the convalescent stage, after from 1 month to 1 year. The results may be divided into three groups: normal scans, low-density lesions, and ventricular abnormalities. 1) Normal scans: CT findings in Cases 1 and 5, showed no abnormalities, although patient 5 had clinically severe encephalitis. 2) Low-density lesions: In Case 3, a slight low-density area was observed in the bilateral thalami only at the acute stage. CT scans in Case 4, obtained 2 and 4 months after the onset, exhibited low-density areas in the bilateral thalami, the left basal ganglia, and the left substantia nigra. In Case 7, diffuse low-density areas in the white matter were found 3 months after the onset. 3) Ventricular abnormalities: CT in Case 2 revealed a moderate dilatation of the ventricular system, which probably suggests normal-pressure hydrocephalus. In 2 other cases, a narrowing or dilatation of the lateral ventricle was observed. The CT findings regarding Japanese encephalitis were discussed in comparison with those of other viral encephalitides, particularly herpes simplex encephalitis.

  15. The attenuation coefficients in CT: Didactic review

    International Nuclear Information System (INIS)

    The review article refers details about the derivation of the Attenuation coefficient of the CT-Number, the electron density and physical density, the effective atomic number, dual KV scanning, the performance of different scanners, furtheron the CT-numbers of intracranial structures, the attempts of characterization of tissue by CT, measurements of effective atomic number and electron density, distribution and probability of occurance of CT-numbers, and distribution of CT-numbers in space. (AJ)

  16. Ct2 Bladder Cancer.

    Science.gov (United States)

    Soloway, Mark S

    2016-09-01

    The patient is an 80-year-old man who presented with gross hematuria. His past medical history indicates he was a cigarette smoker with 50 pack/years. He was successfully treated for carcinoma of the lung 7 years ago. He received chemotherapy, radiation, and surgery. He has mild COPD but has a good performance status. His laboratory studies do not indicate any abnormalities in terms of renal function. He does not have any significant cardiac disease. He has a medium build. He had prostate cancer and underwent a successful radical prostatectomy 10 years ago. His PSA is undetectable. He has some urinary incontinence and wears two pads/day. He underwent the appropriate investigations for gross hematuria. A CT scan of the abdomen and pelvis was normal with the exception of a 4-cm posterior mass in the bladder. There was no hydronephrosis and no enlarged lymph nodes. He underwent a transurethral resection of a solitary bladder tumor performed by another urologist. The tumor was described as large and sessile. It was located on the posterior wall and was approximately 4 cm. The bimanual examination did not reveal a mass. The pathology report stated that the tumor was a high-grade urothelial carcinoma with invasion into the muscularis propria. There was no lymphovascular invasion. I performed a reTURBT, and at that procedure, I did not identify any obvious tumor but the prior resection site was evident. I resected the prior tumor site quite extensively both in depth and width. The pathology revealed only focal carcinoma in situ. There was ample muscle in the specimen and there was some fat as well. As stated, they were free of any cancer. The patient is receptive to any treatment approach. PMID:27457483

  17. Validation of a method to differentiate arterial and venous vessels in CT perfusion data using linear combinations of quantitative time-density curve characteristics

    Energy Technology Data Exchange (ETDEWEB)

    Havla, Lukas; Schneider, Moritz; Dietrich, Olaf [Ludwig-Maximilians-University Hospital Munich, Josef Lissner Laboratory for Biomedical Imaging, Institute for Clinical Radiology, Munich (Germany); Thierfelder, Kolja M.; Beyer, Sebastian E.; Ertl-Wagner, Birgit; Sommer, Wieland H. [Ludwig-Maximilians-University Hospital Munich, Institute for Clinical Radiology, Munich (Germany)

    2015-10-15

    We aimed to develop and evaluate a new method that reliably differentiates between cerebral arteries and veins using voxel-wise CT-perfusion-derived parameters. Fourteen consecutive patients with suspected stroke but without pathological findings were examined on a multi-detector CT system: 32 dynamic phases (∇t = 1.5 s) during application of 35 mL iomeprol-350 were acquired at 80 kV/200mAs. Three hemodynamic parameters were calculated for 18 arterial and venous vessel segments: A (maximum of the time-density-curve), T (time-to-peak), and W (full-width-at-half-maximum). Using receiver operator characteristic (ROC) curve analysis and Fisher's linear discriminant analysis (FLDA), the performance of every classifier (A, T, W) and of all linear combinations for the differentiation of arterial and venous vessels was determined. A maximum area under the ROC-curve (AUC) of 0.945 (accuracy = 86.8 %) was obtained using the FLDA combination of A and T or the triplet FLDA of A and T and W for the classification of venous and arterial vessels. The best single parameter was T with an AUC of 0.871 (accuracy = 79.0 %), which performed significantly worse than the combination A and T (p < 0.001). Arteries and veins can be accurately differentiated based on dynamic CT perfusion data using the maximum of the time-density curve, its time-to-peak, its width, and FLDA combinations of these parameters, which yield accuracies up to 87 %. (orig.)

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

    Directory of Open Access Journals (Sweden)

    Markiet Karolina

    2011-04-01

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

  19. CT of pelvic fractures

    International Nuclear Information System (INIS)

    Although magnetic resonance imaging has become the dominant modality for cross-sectional musculo-skeletal imaging, the widespread availability, speed, and versatility of computed tomography (CT) continue to make it a mainstay of emergency room (ER) diagnostic imaging. Pelvic ring and acetabular fractures occur as the result of significant trauma secondary to either a motor vehicle accident or a high-velocity fall. These injuries are correlated with significant morbidity and mortality, both from the complications of pelvic ring fractures and from commonly associated injuries. The most commonly used classification of pelvic and acetabular fractures has been based on conventional radiographs that are, in the majority of cases, sufficient to determine the type of injury. However, because of the complexity of pelvic and acetabular fractures, precise pathological anatomy is not easily demonstrated by routine radiographs and in many cases details of fractures are not visible. Moreover, the insufficient co-operation of the patient or the difficulty of maintaining special positions can be overcome by using computed tomography. Spiral computed tomography provides information regarding the extent of the fractures and is complementary to radiography for ascertaining the spatial arrangement of fracture fragments. Spiral computed tomography is an effective tool for understanding complex fracture patterns, particularly when combined with multi-planar reconstruction two-dimensional (MPR 2D) reformatted images or three-dimensional images (3D) images. Including these techniques of reconstruction in routine pelvic imaging protocols can change management in a significant number of cases. Subtle fractures, particularly those oriented in the axial plane, are better seen on MPR images or 3D volume-rendered images. Complex injuries can be better demonstrated with 3D volume-rendered images, and complicated spatial information about the relative positions of fracture fragments can be easily

  20. CT of pelvic fractures

    Energy Technology Data Exchange (ETDEWEB)

    Falchi, Marco E-mail: marcofalchi@yahoo.it; Rollandi, Gian Andrea

    2004-04-01

    Although magnetic resonance imaging has become the dominant modality for cross-sectional musculo-skeletal imaging, the widespread availability, speed, and versatility of computed tomography (CT) continue to make it a mainstay of emergency room (ER) diagnostic imaging. Pelvic ring and acetabular fractures occur as the result of significant trauma secondary to either a motor vehicle accident or a high-velocity fall. These injuries are correlated with significant morbidity and mortality, both from the complications of pelvic ring fractures and from commonly associated injuries. The most commonly used classification of pelvic and acetabular fractures has been based on conventional radiographs that are, in the majority of cases, sufficient to determine the type of injury. However, because of the complexity of pelvic and acetabular fractures, precise pathological anatomy is not easily demonstrated by routine radiographs and in many cases details of fractures are not visible. Moreover, the insufficient co-operation of the patient or the difficulty of maintaining special positions can be overcome by using computed tomography. Spiral computed tomography provides information regarding the extent of the fractures and is complementary to radiography for ascertaining the spatial arrangement of fracture fragments. Spiral computed tomography is an effective tool for understanding complex fracture patterns, particularly when combined with multi-planar reconstruction two-dimensional (MPR 2D) reformatted images or three-dimensional images (3D) images. Including these techniques of reconstruction in routine pelvic imaging protocols can change management in a significant number of cases. Subtle fractures, particularly those oriented in the axial plane, are better seen on MPR images or 3D volume-rendered images. Complex injuries can be better demonstrated with 3D volume-rendered images, and complicated spatial information about the relative positions of fracture fragments can be easily

  1. CT Imaging: Basics and New Trends

    Science.gov (United States)

    Peyrin, Françoise; Engelke, Klaus

    This chapter presents the principle of X-ray CT and its evolution during the last 40 years. The first section describes the physical basis of X-ray CT, tomographic image reconstruction algorithms, and the source of artifacts in X-ray CT images. The second section is devoted to the evolution of CT technology from the first translation-rotation systems to multi-slice spiral CTs currently used today. The next section addresses specific developments of CT technology and applications, like perfusion CT, quantitative CT, and spectral CT. The fourth section introduces the problem of radiation exposure delivered to the patient and its evaluation. Finally the last section addresses the development in micro- and even nano-CT which is a rapidly evolving area in preclinical imaging and biology.

  2. CT of malignant pleural mesothelioma

    International Nuclear Information System (INIS)

    Malignant pleural mesothelioma is a rare tumor. Although the chest film findings of pleural mesothelioma are well described, there are few descriptions of the findings of computed tomography (CT). This report describes the CT findings in five cases of pleural mesothelioma. In each case the CT showed an extensive, irregular, pleural-based mass surrounding the lung, spreading into the fissures, and extending into the mediastinum. In two cases there was also extension into the contralateral chest, and in one case each there was extension into the abdomen and chest wall. In each case the chest radiographs underestimated the extent of disease, when compared to CT. When an irregular, pleural-based mass involving most of the hemithorax is identified on CT, the diagnosis of mesothelioma can be suggested and at the same time the extent of the tumor may be evaluated. This is important because the diagnosis of mesothelioma is difficult and because treatment and prognosis may depend on the extent of the disease

  3. New horizons in cardiac CT.

    Science.gov (United States)

    den Harder, A M; Willemink, M J; de Jong, P A; Schilham, A M R; Rajiah, P; Takx, R A P; Leiner, T

    2016-08-01

    Until recently, cardiovascular computed tomography angiography (CCTA) was associated with considerable radiation doses. The introduction of tube current modulation and automatic tube potential selection as well as high-pitch prospective ECG-triggering and iterative reconstruction offer the ability to decrease dose with approximately one order of magnitude, often to sub-millisievert dose levels. In parallel, advancements in computational technology have enabled the measurement of fractional flow reserve (FFR) from CCTA data (FFRCT). This technique shows potential to replace invasively measured FFR to select patients in need of coronary intervention. Furthermore, developments in scanner hardware have led to the introduction of dual-energy and photon-counting CT, which offer the possibility of material decomposition imaging. Dual-energy CT reduces beam hardening, which enables CCTA in patients with a high calcium burden and more robust myocardial CT perfusion imaging. Future-generation CT systems will be capable of counting individual X-ray photons. Photon-counting CT is promising and may result in a substantial further radiation dose reduction, vastly increased spatial resolution, and the introduction of a whole new class of contrast agents. PMID:26932775

  4. CT appearances of talc pleurodesis

    Energy Technology Data Exchange (ETDEWEB)

    Narayanaswamy, S. [Department of Radiology, Derriford Hospital, Plymouth (United Kingdom); Kamath, S. [Department of Radiology, Derriford Hospital, Plymouth (United Kingdom)]. E-mail: srikanthmn@yahoo.com; Williams, M. [Department of Radiology, Derriford Hospital, Plymouth (United Kingdom)

    2007-03-15

    Aim: To report the computed tomography (CT) appearances of talc pleurodesis in the management of patients with pleural effusions and spontaneous pneumothorax. Materials and methods: The post-pleurodesis CT studies of 16 patients obtained over a 5-year period were reviewed. The mean age was 63 years (range 41-79 years). Ten patients were male. After pleurodesis, nine patients underwent a single chest CT examination and seven patients underwent more than one. Results: The characteristic finding observed in all patients, except one, was the presence of high-density deposits in the posterior basal regions of the pleural space. These were typically linear in seven patients, nodular in two, and a combination of linear and nodular in six. In five patients talc deposits were present on both the visceral and parietal pleura separated by an effusion (a variant of the split pleura sign). Talc deposits extended into an interlobar fissure with associated fissural thickening in five patients. In patients who underwent more than one CT study, the appearances remained stable. Conclusions: The typical finding was the presence of high attenuation areas in the posterior basal regions of the pleural space. Two new appearances were observed: extension of talc deposits into the fissure and the presence of a variant of the split pleura sign. It is important to recognize these CT appearances so as not to confuse them with other conditions such as asbestos exposure.

  5. CT appearances of talc pleurodesis

    International Nuclear Information System (INIS)

    Aim: To report the computed tomography (CT) appearances of talc pleurodesis in the management of patients with pleural effusions and spontaneous pneumothorax. Materials and methods: The post-pleurodesis CT studies of 16 patients obtained over a 5-year period were reviewed. The mean age was 63 years (range 41-79 years). Ten patients were male. After pleurodesis, nine patients underwent a single chest CT examination and seven patients underwent more than one. Results: The characteristic finding observed in all patients, except one, was the presence of high-density deposits in the posterior basal regions of the pleural space. These were typically linear in seven patients, nodular in two, and a combination of linear and nodular in six. In five patients talc deposits were present on both the visceral and parietal pleura separated by an effusion (a variant of the split pleura sign). Talc deposits extended into an interlobar fissure with associated fissural thickening in five patients. In patients who underwent more than one CT study, the appearances remained stable. Conclusions: The typical finding was the presence of high attenuation areas in the posterior basal regions of the pleural space. Two new appearances were observed: extension of talc deposits into the fissure and the presence of a variant of the split pleura sign. It is important to recognize these CT appearances so as not to confuse them with other conditions such as asbestos exposure

  6. CT of metastatic spinal tumor

    International Nuclear Information System (INIS)

    CT findings of metastatic spinal tumor were classified into 6 types, i.e., consolidation, dissolution, mottle, doughnut, and ring types, and mixed type of these, and that of no findings. Some statistically significant relationship was found between prostatic cancer and consolidation type, and unknown primary cancer and dissolution type. Abnormal findings of bone scintigraphy was suspected to have metastatic spinal tumor by plain radiography and CT scan in 64/128 (50.0%) and 113/145 (78.6%), respectively. There was some relationship between plain radiographic findings and CT findings; between consolidation type of the former and consolidation type of the latter, dissolution type and dissolution type, compression fracture type and mixed type, the type of no findings and consolidation or mixed type. The most of lesions detected by CT as consolidation or mixed type were revealed by plain radiography. Changes in Ca ammount was not detected by plain radiography and CT scan if it was approximately less than 30% and 18% of the initial Ca respectively. (Ueda, J.)

  7. Functional CT of the kidney

    Energy Technology Data Exchange (ETDEWEB)

    Tsushima, Yoshito. E-mail: yoshito@xa2.so-net.ne.jp

    1999-06-01

    The iodinated contrast agents used for computed tomography (CT) are filtered at the glomerulus and not reabsorbed by the tubules and have pharmacokinetics comparable to inulin. They can thus measure physiological indices such as contrast clearance per unit volume, which is closely related to glomerular filtration rate per unit renal volume of kidney, after due allowance for the difference between blood and plasma clearance. In this review, we show how dynamic CT can be used to measure both regional and global blood clearance of contrast material. A single slice of kidney is scanned sequentially after bolus intravenous (i.v.) injection of contrast material. Next, time-attenuation curves are constructed and contrast clearance per unit volume is calculated using a Patlak graphical analysis. CT determination of renal volume is made and global contrast clearance can be then also calculated. In normal kidneys, clearance/volume averaged 0.49{+-}0.11 ml min{sup -1} ml{sup -1} (mean {+-}S.D.), and these values agreed with literature data obtained using other techniques. A negative correlation between patient's age and clearance/volume was seen. A strong correlation was observed between creatinine whole blood clearance and the global contrast clearance (the product of renal volume determined by CT and contrast clearance/volume). Dynamic CT can provide quantitative renal physiological information on a regional basis non-invasively.

  8. CT findings of exophageal perforation

    Energy Technology Data Exchange (ETDEWEB)

    Heo, Jeong Nam; Choi, Yo Won; Jeon, Seok Chol; Park, Choong Ki; Hahm, Chang Kok [Hanyang University College of Medicine, Seoul (Korea, Republic of)

    2002-09-01

    To determine which CT findings are useful for the early disgnosis of esophageal perforation, and on the basis of these findings, to assess the accuracy of prediction of the perforation site. A review of medical records indicated that between January 1995 and December 2001, 36 patients with esophageal perforation were admitted to our hospital. Thirteen of these [M:F=8:5, age; 28-69 (mean, 52.4) years], who had undergone CT chest scanning, were included in this study. The causes of esophageal perforation were trauma (n=5), infectious diseases (n=4), Boerhaave syndrome (n=1), lung cancer (n=1), esophageal cancer (n=1), and idiopathic. Two chest radiologists unaware of the clinical findings reviewed the CT scans and predicted whether the upper or lower esophagus was perforated. The most common CT finding was extraluminal air at the posterior mediastinum (n=11), while other findings included pulmonary consolidation (n=10), pleural effusion (n=7), discontinuity of the esophageal wall (n=6) and subcutaneous emphysema (n=4), fluid collection around the esophagus (n-4), esophageal wall thickening (n=4), pneumothorax (n=2), and lung abscess (n=2). The perforation site was accurately predicted in 76.9% of cases (10/13). The CT findings which help the diagnosis of esophageal perforation, and prediction of the sites at which it occurs, are extraluminal air of fluid collection, focal defect of the esophageal wall, and esophageal wall thickening.

  9. Cerebral CT of ischaemic lesions

    Energy Technology Data Exchange (ETDEWEB)

    Aulich, A.

    1981-11-25

    The diagnosis of stroke must first be established by clinical examination. CT has proved useful for confirmation of the diagnosis and provides a global intracranial picture of morphological changes in cerebral vascular diseases. A hemorrhage can be recognized with certainty at the first CT examination as the cause of the stroke, but in the detection of a lesion due to ischemia an important role is played by the correct choice of the time of examination, and in some cases also of the check-up with contrast medium. The differential diagnosis between infarct in the acute stage and encephalitis or gliomas of low-grade malignity can be difficult. A decision can often only be made after a series of examinations. Postmalacial conditions are often difficult to differentiate from defects due to other causes, such as hemorrhage, head injury, postoperative states and after encephalitis. A knowledge of the anamnesis and the clinical findings is indispensable for CT evaluation. In assessing the prognosis before vascular surgery on the extracranial brain-supplying vessels the performance of a CT examination should be advised. A warning is given against the use of CT as a screening method.

  10. SPECT-CT and PET-CT progress in the research of computer analysis method

    OpenAIRE

    Jingang Guo; Shuming Xu; Xiaoli Zhang; Hongyu Zhang

    2015-01-01

    The development of multimodal imaging equipment is milestone in the development of imaging, after the PET-CT, American GE company launched a Discovery 670 NM/CT, CT and SPECT, the organic integration of the formation of SPECT-CT new molecular medical imaging equipment, with SPECT, CT and PET-CT is getting more and more widely attention and application, many of SPECT-CT and PET-CT image analysis computer method arises at the historic moment, getting increasing attention of the clinical and ima...

  11. Semi-automated scoring of pulmonary emphysema from X-ray CT: Trainee reproducibility and accuracy

    Energy Technology Data Exchange (ETDEWEB)

    Owrangi, Amir M., E-mail: aowrangi@robarts.ca [Imaging Research Laboratories, Robarts Research Institute, London (Canada); Entwistle, Brandon, E-mail: Brandon.Entwistle@londonhospitals.ca; Lu, Andrew, E-mail: Andrew.Lu@londonhospitals.ca; Chiu, Jack, E-mail: Jack.Chiu@londonhospitals.ca; Hussain, Nabil, E-mail: Nabil.Hussain@londonhospitals.ca; Etemad-Rezai, Roya, E-mail: Roya.EtemadRezai@lhsc.on.ca; Parraga, Grace, E-mail: gparraga@robarts.ca [Imaging Research Laboratories, Robarts Research Institute, London (Canada); Graduate Program in Biomedical Engineering, Department of Medical Imaging, Department of Medical Biophysics, The University of Western Ontario, London (Canada)

    2013-11-01

    Objective: We developed a semi-automated tool to quantify emphysema from thoracic X-ray multi-detector (64-slice) computed tomography (CT) for training purposes and multi-reader studies. Materials and Methods: Thoracic X-ray CT was acquired in 93 ex-smokers, who were evaluated by six trainees with little or no expertise (trainees) and a single experienced thoracic radiologist (expert). A graphic user interface (GUI) was developed for emphysema quantification based on the percentile of lung where a score of 0 = no abnormalities, 1 = 1–25%, 2 = 26–50%, 3 = 51–75% and 4 = 76–100% for each lung side/slice. Trainees blinded to subject characteristics scored randomized images twice; accuracy was determined by comparison to expert scores, density histogram 15th percentile (HU{sub 15}), relative area at −950 HU (RA{sub 950}), low attenuation clusters at −950 HU (LAC{sub 950}), −856 HU (LAC{sub 856}) and the diffusing capacity for carbon monoxide (DL{sub CO%pred}). Intra- and inter-observer reproducibility was evaluated using coefficients-of-variation (COV), intra-class (ICC) and Pearson correlations. Results: Trainee–expert correlations were significant (r = 0.85–0.97, p < 0.0001) and a significant trainee bias (0.15 ± 0.22) was observed. Emphysema score was correlated with RA{sub 950} (r = 0.88, p < 0.0001), HU{sub 15} (r = −0.77, p < 0.0001), LAC{sub 950} (r = 0.76, p < 0.0001), LAC{sub 856} (r = 0.74, p = 0.0001) and DL{sub CO%pred} (r = −0.71, p < 0.0001). Intra-observer reproducibility (COV = 4–27%; ICC = 0.75–0.94) was moderate to high for trainees; intra- and inter-observer COV were negatively and non-linearly correlated with emphysema score. Conclusion: We developed a GUI for rapid and interactive emphysema scoring that allows for comparison of multiple readers with clinical and radiological standards.

  12. Semi-automated scoring of pulmonary emphysema from X-ray CT: Trainee reproducibility and accuracy

    International Nuclear Information System (INIS)

    Objective: We developed a semi-automated tool to quantify emphysema from thoracic X-ray multi-detector (64-slice) computed tomography (CT) for training purposes and multi-reader studies. Materials and Methods: Thoracic X-ray CT was acquired in 93 ex-smokers, who were evaluated by six trainees with little or no expertise (trainees) and a single experienced thoracic radiologist (expert). A graphic user interface (GUI) was developed for emphysema quantification based on the percentile of lung where a score of 0 = no abnormalities, 1 = 1–25%, 2 = 26–50%, 3 = 51–75% and 4 = 76–100% for each lung side/slice. Trainees blinded to subject characteristics scored randomized images twice; accuracy was determined by comparison to expert scores, density histogram 15th percentile (HU15), relative area at −950 HU (RA950), low attenuation clusters at −950 HU (LAC950), −856 HU (LAC856) and the diffusing capacity for carbon monoxide (DLCO%pred). Intra- and inter-observer reproducibility was evaluated using coefficients-of-variation (COV), intra-class (ICC) and Pearson correlations. Results: Trainee–expert correlations were significant (r = 0.85–0.97, p < 0.0001) and a significant trainee bias (0.15 ± 0.22) was observed. Emphysema score was correlated with RA950 (r = 0.88, p < 0.0001), HU15 (r = −0.77, p < 0.0001), LAC950 (r = 0.76, p < 0.0001), LAC856 (r = 0.74, p = 0.0001) and DLCO%pred (r = −0.71, p < 0.0001). Intra-observer reproducibility (COV = 4–27%; ICC = 0.75–0.94) was moderate to high for trainees; intra- and inter-observer COV were negatively and non-linearly correlated with emphysema score. Conclusion: We developed a GUI for rapid and interactive emphysema scoring that allows for comparison of multiple readers with clinical and radiological standards

  13. A New Proton CT Scanner

    CERN Document Server

    Coutrakon, G; Boi, S; Dyshkant, A; Erdelyi, B; Hedin, D; Johnson, E; Krider, J; Rykalin, V; Uzunyan, S A; Zutshi, V; Fordt, R; Sellberg, G; Rauch, J E; Roman, M; Rubinov, P; Wilson, P; Naimuddin, M

    2014-01-01

    The design, construction, and preliminary testing of a second generation proton CT scanner is presented. All current treatment planning systems at proton therapy centers use X-ray CT as the primary imaging modality for treatment planning to calculate doses to tumor and healthy tissues. One of the limitations of X-ray CT is in the conversion of X-ray attenuation coefficients to relative (proton) stopping powers, or RSP. This results in more proton range uncertainty, larger target volumes and therefore, more dose to healthy tissues. To help improve this, we present a novel scanner capable of high dose rates, up to 2~MHz, and large area coverage, 20~x~24~cm$^2$, for imaging an adult head phantom and reconstructing more accurate RSP values.

  14. Bowel preparation for CT colonography

    Energy Technology Data Exchange (ETDEWEB)

    Neri, Emanuele, E-mail: emanuele.neri@med.unipi.it [Diagnostic and Interventional Radiology, University of Pisa (Italy); Lefere, Philippe; Gryspeerdt, Stefaan [Department of Radiology, Stedelijk Ziekenhuis, Roeselare (Belgium); Bemi, Pietro; Mantarro, Annalisa; Bartolozzi, Carlo [Diagnostic and Interventional Radiology, University of Pisa (Italy)

    2013-08-15

    Bowel preparation represents an essential part of CT colonography, as the accuracy of the exam is strongly related to the adequacy of colonic cleansing, and a poor bowel preparation may compromise the diagnostic quality even despite optimization of all other acquisition parameters. Residual stool and fluid in the large bowel may affect the interpretation of the exam and may increase the number of false positives and false negatives. In this regard, the majority of patients having undergone CT colonography state that bowel preparation is the most unpleasant part. Unfortunately, to date no definite consensus has been reached about the ideal bowel preparation technique, and there is great variability in preparation strategies across diagnostic centers. The purpose of this review article is to describe the development and evolution of bowel preparation techniques in order to choose the best approach for optimizing the diagnostic quality of CT colonography in each patient.

  15. CT findings in cerebellar hemangioblastomas

    Energy Technology Data Exchange (ETDEWEB)

    Heiss, E.; Albert, F.

    1982-02-01

    The computed tomographic (CT) findings in 16 personal cases of cerebellar hemangioblastomas are presented. Accordings to other reports in the literature, three-quarters of the tumours were cystic, containing a small mural nodule, whereas the others were predominantly solid. By CT scan the cystic tumours were always identified as roundish or oval space-occupying lesions, sharply demarcated from the surrounding tissue. The solid portion of these tumours, projecting into the cystic part, was delineated more precisely by contrast enhancement, but sometimes escaped identification. On the contrary, even after contrast enhancement the predominantly solid tumours could not be clearly identified as hemangioblastomas. Calcification could not be demonstrated. Additional angiographic investigations were imperative in order to establish the diagnosis, besides visualizing further hypervascular nodules of hemangioblastoma, which CT scanning failed to reveal.

  16. CT diagnosis of abdominal abscesses

    International Nuclear Information System (INIS)

    The noninvasive nature and amount of information obtained using computed tomography have very quickly put this method of diagnosis to the forefront of the interest of the medical public. So far the authors examined 21 cases of intraabdominal abscess. The successful detection of the abscess depends on the site of the abscess, the stage of development, the size, the choice of measuring program and the experience of the examining physician. The diagnostic possibilities of CT as compared with other radiological methods are by far the best. Ultrasound and scintigraphy are also highly successful but CT also allows the physician to localize the abscess, to determine its size, shape and distance from neighbouring organs which is very important in targeted aspiration biopsy. CT also makes it possible to estimate the stage of development, to make a choice of therapy and to evaluate the state of healing or the success of drainage. (author)

  17. Primary hepatic sarcomas: CT findings

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Ri-Sheng; Chen, Ying; Jiang, Biao; Wang, Liu-Hong [Zhejiang University School of Medicine, Department of Radiology, Hangzhou (China); Xu, Xiu-Fang [Zhejiang Medical College, Teaching and Research Group of Radiology, Hangzhou (China)

    2008-10-15

    Primary hepatic sarcomas are rare tumors that are difficult to diagnose clinically. Different primary hepatic sarcomas may have different clinical, morphologic, and radiological features. In this pictorial review, we summarized computed tomography (CT) findings of some relatively common types of hepatic sarcomas, including angiosarcoma, epithelioid hemangioendothelioma (EHE), liposarcoma, undifferentiated embryonal sarcoma (UES), leiomyosarcoma, malignant fibrous histiocytoma (MFH), and carcinosarcoma (including cystadenocarcinosarcoma). To our knowledge, hepatic cystadenocarcinosarcoma has not been described in the English literature. The CT findings in our case are similar to that of cystadenocarcinoma, a huge, multilocular cystic mass with a large mural nodule and solid portion. The advent of CT has allowed earlier detection of primary hepatic sarcomas as well as more accurate diagnosis and characterization. In addition, we briefly discuss the MRI findings and diagnostic value of primary hepatic sarcomas. (orig.)

  18. Normal pediatric postmortem CT appearances

    International Nuclear Information System (INIS)

    Postmortem radiology is a rapidly developing specialty that is increasingly used as an adjunct to or substitute for conventional autopsy. The goal is to find patterns of disease and possibly the cause of death. Postmortem CT images bring to light processes of decomposition most radiologists are unfamiliar with. These postmortem changes, such as the formation of gas and edema, should not be mistaken for pathological processes that occur in living persons. In this review we discuss the normal postmortem thoraco-abdominal changes and how these appear on CT images, as well as how to differentiate these findings from those of pathological processes. (orig.)

  19. Normal pediatric postmortem CT appearances

    Energy Technology Data Exchange (ETDEWEB)

    Klein, Willemijn M.; Bosboom, Dennis G.H.; Koopmanschap, Desiree H.J.L.M. [Radboud University Medical Center, Department of Radiology and Nuclear Medicine, Nijmegen (Netherlands); Nievelstein, Rutger A.J. [University Medical Center Utrecht, Department of Radiology, Utrecht (Netherlands); Nikkels, Peter G.J. [University Medical Center Utrecht, Department of Pathology, Utrecht (Netherlands); Rijn, Rick R. van [Academic Medical Center, Department of Radiology, Amsterdam (Netherlands)

    2015-04-01

    Postmortem radiology is a rapidly developing specialty that is increasingly used as an adjunct to or substitute for conventional autopsy. The goal is to find patterns of disease and possibly the cause of death. Postmortem CT images bring to light processes of decomposition most radiologists are unfamiliar with. These postmortem changes, such as the formation of gas and edema, should not be mistaken for pathological processes that occur in living persons. In this review we discuss the normal postmortem thoraco-abdominal changes and how these appear on CT images, as well as how to differentiate these findings from those of pathological processes. (orig.)

  20. CT findings of pulmonary aspergillosis

    Energy Technology Data Exchange (ETDEWEB)

    Cheon, Jung Eun; Im, Jung Gi; Goo, Jin Mo; Kim, Hong Dae; Han, Man Chung [Seoul National University College of Medicine, Seoul (Korea, Republic of)

    1995-10-15

    The fungus aspergillus can cause a variety of pulmonary disorders. Aspergilloma is a noninvasive aspergillus colonization of virtually any type of preexisting pulmonary cavity or cystic space. Invasive pulmonary aspergillosis is serious, usually fatal infection in patients being treated with immunosuppressants or who have chronic debilitating disease. Allergic bronchopulmonary aspergillosis is characterized clinically by asthma, blood and sputum eosinophilia and positive immunologic reaction to aspergillus antigen. Awareness of the radiographic and CT findings of pulmonary aspergillosis is important in making the diagnosis of aspergillus-caused pulmonary disorders. In this pictorial essay, we illustrated various radiological findings of pulmonary aspergillosis focused on CT findings correlated with gross pathologic specimens.

  1. Low-dose interpolated average CT for attenuation correction in cardiac PET/CT

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Tung-Hsin [Department of Biomedical Imaging and Radiological Sciences, National Yang Ming University, Taiwan (China); Zhang, Geoffrey [Department of Radiation Oncology, Moffitt Cancer Center, Florida (United States); Wang, Shyh-Jen [Department of Biomedical Imaging and Radiological Sciences, National Yang Ming University, Taiwan (China); Department of Nuclear Medicine, Taipei Veterans General Hospital, Taiwan (China); Chen, Chih-Hao [Department of Nuclear Medicine, Taipei Veterans General Hospital, Taiwan (China); Yang, Bang-Hung [Department of Biomedical Imaging and Radiological Sciences, National Yang Ming University, Taiwan (China); Department of Nuclear Medicine, Taipei Veterans General Hospital, Taiwan (China); Wu, Nien-Yun [Department of Nuclear Medicine, Taipei Veterans General Hospital, Taiwan (China); Huang, Tzung-Chi, E-mail: tzungchi.huang@mail.cmu.edu.t [Department of Biomedical Imaging and Radiological Science, China Medical University, Taiwan (China)

    2010-07-21

    Because of the advantages in the use of high photon flux and thus the short scan times of CT imaging, the traditional {sup 68}Ge scans for positron emission tomography (PET) image attenuation correction have been replaced by CT scans in the modern PET/CT technology. The combination of fast CT scan and slow PET scan often causes image misalignment between the PET and CT images due to respiration motion. Use of the average CT derived from cine CT images is reported to reduce such misalignment. However, the radiation dose to patients is higher with cine CT scans. This study introduces a method that uses breath-hold CT images and their interpolations to generate the average CT for PET image attenuation correction. Breath-hold CT sets are taken at end-inspiration and end-expiration. Deformable image registration is applied to generate a voxel-to-voxel motion matrix between the two CT sets. The motion is equally divided into 5 steps from inspiration to expiration and 5 steps from expiration to inspiration, generating a total of 8 phases of interpolated CT sets. An average CT image is generated from all the 10 phase CT images, including original inhale/exhale CT and 8 interpolated CT sets. Quantitative comparison shows that the reduction of image misalignment artifacts using the average CT from the interpolation technique for PET attenuation correction is at a similar level as that using cine average CT, while the dose to the patient from the CT scans is reduced significantly. The interpolated average CT method hence provides a low dose alternative to cine CT scans for PET attenuation correction.

  2. Low-dose interpolated average CT for attenuation correction in cardiac PET/CT

    International Nuclear Information System (INIS)

    Because of the advantages in the use of high photon flux and thus the short scan times of CT imaging, the traditional 68Ge scans for positron emission tomography (PET) image attenuation correction have been replaced by CT scans in the modern PET/CT technology. The combination of fast CT scan and slow PET scan often causes image misalignment between the PET and CT images due to respiration motion. Use of the average CT derived from cine CT images is reported to reduce such misalignment. However, the radiation dose to patients is higher with cine CT scans. This study introduces a method that uses breath-hold CT images and their interpolations to generate the average CT for PET image attenuation correction. Breath-hold CT sets are taken at end-inspiration and end-expiration. Deformable image registration is applied to generate a voxel-to-voxel motion matrix between the two CT sets. The motion is equally divided into 5 steps from inspiration to expiration and 5 steps from expiration to inspiration, generating a total of 8 phases of interpolated CT sets. An average CT image is generated from all the 10 phase CT images, including original inhale/exhale CT and 8 interpolated CT sets. Quantitative comparison shows that the reduction of image misalignment artifacts using the average CT from the interpolation technique for PET attenuation correction is at a similar level as that using cine average CT, while the dose to the patient from the CT scans is reduced significantly. The interpolated average CT method hence provides a low dose alternative to cine CT scans for PET attenuation correction.

  3. Low-dose interpolated average CT for attenuation correction in cardiac PET/CT

    Science.gov (United States)

    Wu, Tung-Hsin; Zhang, Geoffrey; Wang, Shyh-Jen; Chen, Chih-Hao; Yang, Bang-Hung; Wu, Nien-Yun; Huang, Tzung-Chi

    2010-07-01

    Because of the advantages in the use of high photon flux and thus the short scan times of CT imaging, the traditional 68Ge scans for positron emission tomography (PET) image attenuation correction have been replaced by CT scans in the modern PET/CT technology. The combination of fast CT scan and slow PET scan often causes image misalignment between the PET and CT images due to respiration motion. Use of the average CT derived from cine CT images is reported to reduce such misalignment. However, the radiation dose to patients is higher with cine CT scans. This study introduces a method that uses breath-hold CT images and their interpolations to generate the average CT for PET image attenuation correction. Breath-hold CT sets are taken at end-inspiration and end-expiration. Deformable image registration is applied to generate a voxel-to-voxel motion matrix between the two CT sets. The motion is equally divided into 5 steps from inspiration to expiration and 5 steps from expiration to inspiration, generating a total of 8 phases of interpolated CT sets. An average CT image is generated from all the 10 phase CT images, including original inhale/exhale CT and 8 interpolated CT sets. Quantitative comparison shows that the reduction of image misalignment artifacts using the average CT from the interpolation technique for PET attenuation correction is at a similar level as that using cine average CT, while the dose to the patient from the CT scans is reduced significantly. The interpolated average CT method hence provides a low dose alternative to cine CT scans for PET attenuation correction.

  4. Your Radiologist Explains CT Colonography

    Medline Plus

    Full Text Available ... test that is used to screen the large intestine or colon for cancer and growths called polyps. This procedure uses low-dose CT or CAT scanning to produce pictures of the colon and the rectum. During the examination, a small tube is inserted a short distance into the rectum to allow for inflation ...

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

    Medline Plus

    Full Text Available ... detailed images of your child’s internal organs, bones, soft tissues and blood vessels. It may be used to ... or DVD. CT images of internal organs, bones, soft tissue and blood vessels typically provide greater detail than ...

  6. Recent developments in CT colonography

    International Nuclear Information System (INIS)

    CT colonography allows reliable, non-invasive, rapid, high resolution imaging of the whole large bowel. Recent advances in technology such as computer-aided detection (CAD), scanning with or without bowel preparation, and low radiation are continually developing to improve the efficacy of this technique. This review will update the reader as to ongoing developments while presenting current thinking from the gastroenterological perspective

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

    Medline Plus

    Full Text Available ... can be performed if you have an implanted medical device of any kind, unlike MRI. CT imaging provides real-time imaging, making it a good tool for guiding minimally invasive procedures such as needle ... is not a medical facility. Please contact your physician with specific medical ...

  8. Physiology and physiopathology at CT

    International Nuclear Information System (INIS)

    Although CT is essentially a morphological technique, it should theoretically enable investigation of certain physiological and physiopathological phenomena to be made, for example by the study of (i) CT numbers and (ii) the nature and evolution of enhancements. Intravenous injection of iodine contrast agent increases the attenuation coefficients of cerebral parenchyma, which is theoretically due only to the enhancement of the vascular compartment and in direct correlation with the cerebral blood volume (CBV). The authors have measured the attenuation coefficients of the blood and the parenchyma at varying times after contrast injection. Two contrast agents with differing osmolarities were studied. Two scanners were used - an ACTA scanner and an ND 8000. Twenty CTs were performed on five patients after a bolus injection of a solution of 38% iodine: sodium ioxithalamate 25.69 g; methylglucamine oxithalamate 51.3 osmolarity 1800 mosmol/12 ml/kg were injected. Leakage of the iodine contrast agent, however, considerably increases the density coefficient of cerebral parenchyma and rules out any accurate measurement of the CBV. CT study of cerebral physiopathology is also discussed. This is dependent on two techniques - measurement of attenuation coefficients and observation of enhancements - neither of which are shown to give results characteristic of any one physiopathology. The application of CT in physiological and physiopathological cerebral phenomena is currently extremely limited. (Auth.)

  9. CT Findings of Malarial Spleens

    Energy Technology Data Exchange (ETDEWEB)

    Jang, Ji Yeon; Kwon, Jung Hyeok; Kim, Mi Jeong; Rho, Byung Hak; Lee, Mi Young [Keimyung University School of Medicine, Daegu (Korea, Republic of)

    2009-10-15

    The purpose of our study was to evaluate the CT findings of malarial spleens. We reviewed the patient records of 44 patients with malaria during a recent 3.5-year period and we selected 18 patients who underwent an abdominal CT scan. We retrospectively evaluated the CT findings of the malarial spleens and we compared then with those of a control group of 18 men. We analyzed the splenic size, whether or not there was mottled striped splenic enhancement during the arterial phase and the differences of splenic attenuation and the attenuation between the liver and spleen during the precontrast phase, the arterial phase and the portal phase between the two groups. In malarial patients, the spleen was enlarged in all cases (p < 0.001), and splenic attenuation and the degree of enhancement were significantly decreased during the precontrast phase, the arterial phase and the portal phase (p < 0.001). Loss of mottled striped enhancement during the arterial phase was seen in 11 cases (61.1%) (p < 0.001). The attenuation of the spleen was lower than that of the liver in 13 cases (72.2%) during the portal phase (p = 0.003) and in 1 case (5.6%) during the arterial phase (p = 1.000). Splenomegaly, decreased splenic enhancement, the lack of mottled striped enhancement during the arterial phase and lower attenuation than that of the liver during the portal phase are helpful CT findings to diagnose the malarial spleen.

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

    Medline Plus

    Full Text Available ... tool for guiding minimally invasive procedures such as needle biopsies and needle aspirations of many areas of the body, particularly the lungs, abdomen, pelvis and bones. Sometimes ultrasound is substituted for CT ... and surgical biopsy. No radiation remains in a patient's body after ...

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

    Medline Plus

    Full Text Available ... to help diagnose abdominal pain or evaluate for injury after trauma. Tell your doctor about your child’s medications and ... diagnose a wide range of conditions due to injury or illness. In children, CT is typically used ...

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

    Medline Plus

    Full Text Available ... minimally invasive procedures such as needle biopsies and needle aspirations of many areas of the body, particularly the ... area scanned as much as possible and to "fine tune" the CT settings based ... information. The benefit of an accurate diagnosis far outweighs the risk. ...

  13. Your Radiologist Explains CT Colonography

    Medline Plus

    Full Text Available ... Test/Treatment Patient Type Screening/Wellness Disease/Condition Safety En Español More Info Images/Videos News Physician ... back to work the same day in most cases. Perhaps you might have some concerns about CT ...

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

    Medline Plus

    Full Text Available ... child may have, and if there is a history of heart disease, asthma, diabetes, kidney disease or ... the patient. The computer that processes the imaging information and monitor are ... in detector technology allow new CT scanners to obtain multiple slices ...

  15. CT "halo sign" in pulmonary tuberculoma.

    Science.gov (United States)

    Gaeta, M; Volta, S; Stroscio, S; Romeo, P; Pandolfo, I

    1992-01-01

    The CT halo sign has been described as the CT finding of a low-attenuation zone surrounding a pulmonary nodule. It is an early clue to the diagnosis of invasive pulmonary aspergillosis. We describe a case of CT halo sign associated with a pulmonary tuberculoma. Therefore, we think that a diagnosis other than invasive pulmonary aspergillosis should be considered in the presence of the CT halo sign in immunocompetent patients.

  16. CT findings of peritoneal carcinomatosis

    International Nuclear Information System (INIS)

    CT findings in 137 patients with peritoneal cacinomatosis were reviewed to determine the CT signs of peritoneal malignancy. CT of the 20 liver cirrhosis and 17 tuberculous peritonitis were also reviewed to define the differential point between benign and malignant peritoneal change. The results were as follows. 1. The most common primary malignancy encountered in peritoneal carcinomatosis was stomach Ca.(50.4%), followed by pancreas Ca, hepatoma, colon Ca. and ovarian Ca. 2. Ascites was the most common CT feature of peritoneal malignancy, present in 99 cases (72.3%). The amount of ascites was voluminous, grade III in 70% of cases and showed high density ascites with average 23 Hounsfield units. 3. Greater omentum involvement was noted in 88 patients, peritoneum in 71 patients and mesentery in 65% patients. There was no correlation of the primary malignancy type with the incidence or pattern of the above mentioned site. 4. Bowel wall thickenings were observed in 51 patients, among which transverse colon was most frequently involved. 5. Mean attenuation value of ascites in liver cirrhosis was 10.7 HU, which was much lower than that of peritoneal carcinomatosis. 6. Even though intraperitoneal findings in Tbc. Peritonitis showed tendency of relatively small amount of ascites with more predominant mesenteric change, but, the findings of high density ascites, change of peritoneum and omentum etc. were very similar to those of peritoneal carcinomatosis. Therefore, based on only intraperitoneal change, differential diagnosis between them was difficult. 7. False negatives in CT diagnosis of peritoneal carcinomatosis occurred in 7 cases. There were tiny nodular changes in intraperitoneal cavity without ascites on operative findings

  17. CT findings of acoustic neuroma

    Energy Technology Data Exchange (ETDEWEB)

    Sim, Do Choul; Lee, Jae Mun; Shinn, Kyung Sub; Bahk, Yong Whee [Catholic Univ., Seoul (Korea, Republic of)

    1987-10-15

    Computed Tomography (CT) is very accurate in evaluating the location, size, shape and extension of acoustic neuroma. We analysed CT findings of 23 acoustic neuromas seen at Department of Radiology, Kangnam St. Mary's Hospital, Catholic University Medical College during the period of from January 1981 to June 1987. 1. Five (22%) were men and 18 (78%) were women with the high incidence occurring in the 4th and 5th decades. 2. Twenty two cases were diagnosed satisfactorily by CT examinations which included axial, coronal and reconstruction images. One with the smallest dimension of 8 mm in diameter could not be detected by the conventional CT scan. But is could be seen after metrizamide cisternography. mean size of the tumor masses was estimated 3.6 cm in diameter. 3. The shape of the tumor was oval in 50%, round in 27% and lobulated in 23%. The masses were presented as hypodense in 50%, isodense in 32% and hyperdense in 18%. All tumors were extended from the internal acoustic and toward the cerebellopontine angle. The internal acoustic canal was widened in 77%. Hydrocephalus was associated in 45%. Widening of cerebellopontine angle cistern was noted in 50%. 4. After contrast infusion the tumors were enhanced markedly in 45%, moderately in 32% and mildly in 23%. The enhanced pattern was homogeneous in 41%, mixed in 41% and rim in 18%. The margin of the tumors was sharply defined in 82%. The tumors were attached to the petrous bone with acute angle in 73%. Cystic change within the tumor was found in 27%. The peritumoral edema was noted in 45%. In conclusion, CT is of most effective modalities to evaluate size, shape, extent and internal architecture of acoustic neuroma as well as relationship with adjacent anatomic structures including the internal acoustic canal.

  18. Usefulness of CT for mediastinal lesions

    Energy Technology Data Exchange (ETDEWEB)

    Matsuoka, Shoji; Okayasu, Toshiki; Yoshida, Tsukasa; Yaoi, Hiromi; Watanabe, Tatsuo (Iwate Prefectural Central Hospital (Japan))

    1982-03-01

    According to the authors' four and a half years' experience with the second-generation CT equipment, the usefulness of CT was described and cases were presented. CT will be even more valuable with improving the equipment.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1999-11-01

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

  20. A comparison of seminal vesicle size on CT between autosomal dominant polycystic kidney disease (ADPKD) patients and normal subjects

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    Joo, Ijin; Kim, Seung Hyup; Cho, Jeong Yeon (Dept. of Radiology, Seoul National Univ. College of Medicine, Inst. of Radiation Medicine, Seoul National Univ., Seoul (Korea)), e-mail: kimsh@radcom.snu.ac.kr

    2010-06-15

    Background: Extrarenal manifestations are common in autosomal dominant polycystic kidney disease (ADPKD). Although seminal vesicles can also be involved in patients with ADPKD, little is known about the size differences of the seminal vesicles between ADPKD patients and normal subjects. Purpose: To determine whether the size of seminal vesicles in ADPKD patients is larger than that in normal subjects with the use of three-dimensional (3D) CT. Material and Methods: Using a retrospective case-control study design, we reviewed the findings of 696 male patients with an age range of 20-69 years who underwent contrast enhanced multi-detector computed tomography (MDCT) imaging of the kidney in our institution from August 2007 to July 2008. A total of 68 male patients with ADPKD comprised the study group. Another 68 age-matched non-ADPKD male patients comprised the control group. The size of bilateral seminal vesicles was assessed by measurement of the short dimension on axial, coronal, and sagittal images by the use of a picture archiving and communication system (PACS). Results: The mean width of seminal vesicles in ADPKD patients was 1.70+-0.40 cm (axial images), 1.86+-0.45 cm (coronal), and 1.59+-0.39 cm (sagittal). For control group subjects, the mean width was 1.53+-0.29 cm (axial), 1.68+-0.43 cm (coronal), and 1.48+-0.31 cm (sagittal). The mean size differences between the ADPKD and control groups for the measured widths on axial and coronal images were statistically significant (P=0.01 and P=0.02, respectively). The width as measured on axial images showed a decrease with age in the control group subjects (linear trend, P=0.005), but no significant decrease was noted in ADPKD patients. Conclusion: The seminal vesicles were demonstrated to be larger in ADPKD patients as compared with normal subjects as determined with the use of 3D CT . Keywords: Autosomal dominant polycystic kidney disease (ADPKD), seminal vesicle, computed tomography, CT