WorldWideScience

Sample records for 128-slice multi-detector ct

  1. Case report: Isolated unilateral pulmonary vein atresia diagnosed on 128-slice multidetector CT

    Rashmi Dixit

    2011-01-01

    Full Text Available Unilateral pulmonary venous atresia is an uncommon entity that is generally believed to be congenital. Most patients present in infancy or childhood with recurrent chest infections or hemoptysis. Pulmonary angiography is usually used for definitive diagnosis. However, the current multislice CT scanners may obviate the need for pulmonary angiography. We report two cases diagnosed using 128-slice CT angiography. On the CT angiography images both these cases demonstrated absent pulmonary veins on the affected side, with a small pulmonary artery and prominent bronchial or other systemic arterial supply.

  2. A 128-slice CT scanner helpful in localising coronary sinus ostium during CRT-D implantation – case report

    Cardiac resynchronization therapy (CRT) has become a successful treatment option for symptomatic heart failure in patients with poor left ventricular (LV) systolic function and broad QRS complex in the surface electrocardiogram (ECG). In this report we present a case of a 70-year-old woman with advanced heart failure due to ischaemic heart disease who underwent an upgrade from VVIR stimulator (pacemaker, PM) to cardiac resynchronization therapy defibrillator (CRT-D). The first attempt was unsuccessful due to problems with inefficient cannulation of the orifice of the coronary sinus (CS). After performing a 3D reconstruction with a 128-slice CT scanner, it was possible to carry out the up-grade to CRT-D resulting in enormous clinical improvement. The case represents an example of the usefulness of 3D reconstruction with the 128-slice CT scanner used after failed CRT-D implantation due to difficulties with efficient cannulation of the coronary sinus orifice in a rare anatomical variant

  3. Assessment of Left Ventricular Function and Volume in Patients Undergoing 128-Slice Coronary CT Angiography with ECG-Based Maximum Tube Current Modulation: a Comparison with Echocardiography

    To compare multi-detector CT (MDCT) using 128-slice coronary CT angiography (Definition AS+, Siemens Medical Solution, Forchheim, Germany) with ECG-based maximum tube current modulation with echocardiography for the determination of left ventricular ejection fraction (LVEF), end-diastolic volume (EDV), end-systolic volume (ESV), as well as assessing coronary artery image quality and patient radiation dose. Thirty consecutive patients (M:F = 20:10: mean age, 57.9 ± 11.4 years) were referred for MDCT for evaluation of atypical chest pain. EF, EDV and ESV were determined for both MDCT and echocardiography, and the correlation coefficients were assessed. Coronary artery segment subjective image quality (1, excellent: 4, poor) and radiation dose were recorded. Left ventricular EF, EDV, and ESV were calculated by MDCT and echocardiography and the comparison showed a significant correlation with those estimated by echocardiography (p < 0.05). Consistently, the LVEFs calculated by MDCT and echocardiography were not statistically different. However, LV, EDV and ESV from MDCT were statistically higher than those from echocardiography (p < 0.05). The average image quality score of the coronary artery segment was 1.10 and the mean patient radiation dose was 3.99 ± 1.85 mSv. Although LV volume was overestimated by MDCT, MDCT provides comparable results to echocardiography for LVEF and LVV, with a low radiation dose

  4. 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

    To describe prospective ECG-triggered dual-source CT dual-step pulsing (pECGdualstep) 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 (pECGdual-step) 128-slice dual-source CT without heart rate control (main padding window: 40% RR interval >65 bpm/70% RR interval dual-step128-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.)

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

    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.

  6. 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.

    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

  7. Estimation of radiation exposure of retrospective gated and prospective triggered 128-slice triple-rule-out CT angiography

    Ketelsen, Dominik; Fenchel, Michael; Thomas, Christoph; Boehringer, Nadine; Tsiflikas, Ilias; Kaempf, Michael; Claussen, Claus D; Heuschmid, Martin (Dept. of Diagnostic and Interventional Radiology, Univ. Hospital Tuebingen, Tuebingen (Germany)), email: dominik.ketelsen@med.uni-tuebingen.de; Buchgeister, Markus (Depts. of Radiotherapy and Radiooncology, Univ. Hospital Tuebingen, Tuebingen (Germany))

    2011-09-15

    Background: CT has become an important role in the differential diagnosis of acute chest pain to exclude an aortic dissection, pulmonary embolism and acute coronary artery syndrome. However, the additional radiation exposure is a cause of concern and dose saving strategies should be applied, if possible. Purpose: To estimate effective dose of retrospective gated and prospective ECG-triggered triple-rule-out computed tomography angiography (TRO-CTA). Material and Methods: An Alderson-Rando-phantom equipped with thermoluminescent dosimeters was used for dose measurements. Exposure was performed on a 128-slice single source scanner. The following scan parameters were used (retrospective ECG-gated): 120 kV, 190 mAs/rot., collimation 128x0.6 mm, rotation time 0.3 s. Protocols with a simulated heart rate (HR) of 60 and 100 bpm were performed using the standard ECG-pulsing as well as MinDose. Additionally, a prospective triggered TRO-CTA was acquired (HR 60 bpm). Results: The estimated effective dose of retrospective ECG-gated TRO-CTA ranged from 7.4-13.4 mSv and from 10.1-17.5 mSv for men and women, respectively. Due to radiosensitive breast tissue, women received a significant increased effective dose of up to 64.7% +- 0.03% (p = 0.028) compared to men. MinDose reduces radiation exposure of up to 33.0% +- 6.5% in comparison to standard ECG-pulsing (p < 0.001). The effective dose increased significantly with lower heart rates (p < 0.001). Prospective ECG-triggered TRO-CTA showed an effective dose of 5.9 mSv and 8.2 mSv for men and women, respectively. Compared to retrospective ECG-gated TRO-CTA a significant dose reduction was observed (p < 0.001). Conclusion: Due to the significant different dose exposure, scan protocols should be specifically adapted in a patient- and problem-oriented manner

  8. 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

    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.)

  9. 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

    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.)

  10. 128-slice acceletated-pitch dual energy CT angiography of the head and neck: comparison of different low contrast medium volumes.

    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.

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

    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

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

    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.

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

    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

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

    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.

  15. 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

    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

  16. 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

    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

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

    Vajjalla Ravikumar

    2013-04-01

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

  18. Step-and-shoot prospectively ECG-gated vs. retrospectively ECG-gated with tube current modulation coronary CT angiography using 128-slice MDCT patients with chest pain: diagnostic performance and radiation dose

    Background With increasing awareness for radiation exposure, the study of diagnostic accuracy of coronary CT angiography (CCTA) with low radiation dose techniques is mandatory to both radiologist and clinician. Purpose To compare diagnostic performance and effective radiation dose between step-and-shoot prospectively ECG-gated and retrospectively ECG-gated with tube current modulation (TCM) CCTA using 128-slice multidetector computed tomography (MDCT). Material and Methods We retrospectively evaluated 60 patients who underwent CCTA with either of two different low-dose techniques using 128-slice MDCT (23 patients for step-and shoot-prospectively ECG-gated and 37 patients for retrospectively ECG-gated with TCM CCTA) followed by conventional coronary angiography. All coronary arteries and all segments thereof, except anatomical variants or small size (< 1.5 mm) ones, were included in analysis. Results In per-segment analysis, sensitivity, specificity, positive predictive value, and negative predictive value were 91/96%, 95/94%, 75/73%, and 98/99% for step-and-shoot prospectively ECG-gated and retrospectively ECG gated with TCM CCTA, respectively, relative to conventional coronary angiography. Effective radiation dose were 1.75 ± 0.83 mSv, 4.91 ± 1.71 mSv in the step-and-shoot prospectively ECG-gated and retrospectively ECG-gated with TCM CCTA groups, respectively. Conclusion The two low-radiation dose CCTA techniques using 128-slice MDCT yields comparable diagnostic performance for coronary artery disease in symptomatic patients with low heart rates

  19. Multi-detector CT knee arthrography - initial experience

    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

  20. 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

    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。

  1. 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

    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.)

  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

    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. 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

    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.)

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

    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.

  5. 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

    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。

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

    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.

  7. 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

    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.)

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

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

    2005-01-01

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

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

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

  10. Predicting Resectability of Pancreatic Head Cancer with Multi-Detector CT. Surgical and Pathologic Correlation

    Damien Olivié

    2007-11-01

    Full Text Available Context Computed tomography is widely used to pre-operatively evaluate patients with ductal carcinoma of the pancreas. Objective To prospectively evaluate the ability of multi-detector computed tomography to predict resectability of pancreatic head cancer. Patients Ninety-one consecutive patients (53 men, 38 women; mean age, 61 years referred to our department with a diagnosis of cancer of the head of the pancreas underwent a preoperative contrast enhanced triphasic 16- slice multi-detector computed tomography. Sixty-three were considered inoperable because of advanced local disease, metastatic disease, or poor surgical risk. Intervention Of the remaining 28 patients, 23 underwent a Whipple procedure, whereas 5 patients underwent a palliative procedure. Main outcome measures Surgical and pathologic reports were reviewed and compared to CT results. Results Of the 91 patients evaluated, 25% had successful resection of pancreatic head carcinoma; while only 5% had a palliative procedure. When compared to surgical outcome, the positive predictive value of multi-detector computed tomography for resectability was 100%. On the basis of pathologic results, the positive predictive value of multi-detector computed tomography for resectability fell to 83%, Four patients deemed resectable following multi-detector computed tomography had positive margins at pathology. Conclusion The positive predictive value of multi-detector computed tomography for resectable disease is lower when pathologic correlation, as opposed to surgical correlation, is used as the gold standard. Compared to previous studies, there was a lower rate of palliative surgery in our cohort.

  11. Accuracy of the CT numbers of simulated lung nodules imaged with multi-detector CT scanners

    A study was performed to determine the accuracies and reproducibilities of the CT numbers of simulated lung nodules imaged with multi-detector CT scanners. The nodules were simulated by spherical balls of three diameters (4.8, 9.5, and 16 mm) and two compositions (50 and 100 mg/cc CaCO3 in water-equivalent plastic). All were scanned in a liquid-water-filled container at the center of a water-equivalent-plastic phantom and in air cavities within the same phantom using GE multi-detector CT scanners. The nodules were also scanned within simulated lung regions in an anthropomorphic thorax section phantom that was bolused on both sides with water-equivalent slabs. Results were compared for three scanning protocols--the protocol for the National Lung Screening Trial (NLST), the protocol for the Lung Tissue Research Consortium (LTRC) study, and a high resolution (small pitch, thin slice and small scan interval) higher dose ''gold standard'' protocol. Scans were repeated three times with each protocol to assess reproducibility. The CT numbers of the nodules in water were found to be nearly independent of nodule size. However, the presence and the size of an air cavity surrounding a nodule had a significant effect (e.g., the CT number of a 50 mg/cc nodule was 64 HU in water, 37 HU in a 1.8 cm diameter air cavity, and 19 HU in a 4.4 cm diameter air cavity). This variability of CT number with size of air cavity may affect the results of the LTRC study in which patients are scanned at both full inspiration and full expiration. The CT numbers of the 9.5 and 16 mm diameter nodules within the anthropomorphic phantom were highly reproducible (average standard deviations of 2 HU or less) for all protocols. On the other hand, both accuracy and reproducibility were significantly degraded for the 4.8 mm diameter nodules, especially for the NLST (2.5 mm thickness, 2 mm slice interval) technique. Use of thinner slice (1.25 mm) and slice interval (1.25 mm) scans that can be reconstructed

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

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

    2007-06-15

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

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

    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.

  14. Determination of the weighted CT dose index in modern multi-detector CT scanners

    The aim of the present study was to (a) evaluate the underestimation in the value of the free-in-air (CTDIair) and the weighted CT dose index (CTDIw) determined with the standard 100 mm pencil chamber, i.e. the CTDI100 concept, for the whole range of nominal radiation beam collimations selectable in a modern multi-slice CT scanner (b) estimate the optimum length of the pencil-chamber and phantoms for accurate CTDIw measurements and (c) provide CTDIw values normalized to free-in-air CTDI for different tube-voltage, nominal radiation beam collimations and beam filtration values. The underestimation in the determination of CTDIair and CTDIw using the CTDI100 concept was determined from measurements obtained with standard polymethyl-methacrylate (PMMA) phantoms and arrays of thermoluminescence dosimeters. The Monte Carlo N-Particle transport code was used to simulate standard CTDI measurements on a 16-slice CT scanner. The optimum pencil-chamber length for accurate determination of CTDIw was estimated as the minimum chamber length for which a further increase in length does not alter the value of the CTDI. CTDIw/CTDIair ratios were determined using Monte Carlo simulation and the optimum detector length for all selectable tube-voltage values and for three different values of beam filtration. To verify the Monte Carlo results, measured values of CTDIw/CTDIair ratios using the standard 100 mm pencil ionization chamber were compared with corresponding values calculated with Monte Carlo experiments. The underestimation in the determination of CTDIair using the 100 mm pencil chamber was less than 1% for all beam collimations. The underestimation in CTDIw was 15% and 27% for head and body phantoms, respectively. The optimum detector length for accurate CTDIw measurements was found to be 50 cm for the beam collimations commonly employed in modern multi-detector (MD) CT scanners. The ratio of CTDIw/CTDIair determined using the optimum detector length was found to be independent

  15. The initial clinical application of multi-detector CT on spinal angiography

    Objective: To explore the value of Multi-detector CT in spinal cord angiography. Methods: Ten patients with initial MR and clinical findings suggestive of spinal cord vessel disease were performed CT spinal cord angiography. Among these, 7 patients were performed DSA later within 1 week, and 4 patients were therapy by operation. CT protocol: Toshiba Aquilion 64 slice CT scanner, 0.5 mm thickness, 0.5/r, 120 kV, 350 mA, choose aortic arch level as inspection position, and use 'surestart' technique with CT threshold 180 HU. Contrast medium was Iohexol (370 mg I/ml), with injection velocity of 6 ml/s. The total volume was 80 ml. The CT spinal cord angiography images were analyzed according to disease model, disease range, feeding artery, fistula, draining veins, and were compared with DSA and operation results. Results: All CT spinal cord angiography images displayed spinal vessel malformation. Among these, 3 patients were inner-medullary arteriovenous malformation; 2 patients were peri-medullary arteriovenous fistula; 5 patients were spinal dural arteriovenous fistula. All cases showed disease range, and draining veins clearly, one patient had two vessels that were false positive, and all the other cases showed feeding arteries clearly, which were confirmed by DSA. Conclusion: There are great values for CT spinal angiography in diagnosing spinal vessel disease, it can be a screening exam before DSA. (authors)

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

    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.)

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

    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.)

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

    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)

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

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

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

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

    2015-01-01

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

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

    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.

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

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

    2006-01-01

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

  3. Carotid stenosis assessment with multi-detector CT angiography: comparison between manual and automatic segmentation methods.

    Zhu, Chengcheng; Patterson, Andrew J; Thomas, Owen M; Sadat, Umar; Graves, Martin J; Gillard, Jonathan H

    2013-04-01

    Luminal stenosis is used for selecting the optimal management strategy for patients with carotid artery disease. The aim of this study is to evaluate the reproducibility of carotid stenosis quantification using manual and automated segmentation methods using submillimeter through-plane resolution Multi-Detector CT angiography (MDCTA). 35 patients having carotid artery disease with >30 % luminal stenosis as identified by carotid duplex imaging underwent contrast enhanced MDCTA. Two experienced CT readers quantified carotid stenosis from axial source images, reconstructed maximum intensity projection (MIP) and 3D-carotid geometry which was automatically segmented by an open-source toolkit (Vascular Modelling Toolkit, VMTK) using NASCET criteria. Good agreement among the measurement using axial images, MIP and automatic segmentation was observed. Automatic segmentation methods show better inter-observer agreement between the readers (intra-class correlation coefficient (ICC): 0.99 for diameter stenosis measurement) than manual measurement of axial (ICC = 0.82) and MIP (ICC = 0.86) images. Carotid stenosis quantification using an automatic segmentation method has higher reproducibility compared with manual methods. PMID:23135615

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

    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.

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

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

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

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

    2005-01-01

    AIM: The purpose of this study was to compare the diagnostic accuracy of biphasic multi-detector row helical computed tomography (MDCT), digital subtraction angiography (DSA)and Lipiodol computed tomography (CT) in detection of hypervascular hepatocellular carcinoma (HCC).METHODS: Twenty-eight patients with nodular HCC underwent biphasic MDCT examination: hepatic arterial phase (HAP) 25 s and portal venous phase (PVP) 70 s after injection of the contrast medium (1.5 mL/kg). They also underwent hepatic angiography and intra-arterial infusion of iodized oil. Lipiodol CT was performed 3-4 wk after infusion. MDCT images were compared with DSA and Lipiodol CT images for detection of hepatic nodules.RESULTS: The three imaging techniques had the same sensitivity in detecting nodules >20 mm in diameter. There was no significant difference in the sensitivity among HAP-MDCT, Lipiodol CT and DSA for nodules of 10-20 mm in diameter. For the nodules <10 mm in diameter, HAP-MDCT identified 47, Lipiodol CT detected 27 (X2= 11.3, P= 0.005<0.01, HAP-MDCT vs Lipiodol CT) and DSA detected 16(X2= 9.09, P= 0.005<0.01 vs Lipiodol CT and X2= 29.03,P = 0.005<0.01 vs HAP-MDCT). However, six nodules <10 mm in diameter were detected only by Lipiodol CT.CONCLUSION: MDCT and Lipiodol CT are two complementary modalities. At present, MDCT does not obviate the need for DSA and subsequent Lipiodol CT as a preoperative examination for HCC.

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

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

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

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

    2004-08-01

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

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

    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)

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

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

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

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

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

    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.

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

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

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

    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.

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

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

    2010-02-15

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

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

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

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

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

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

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

    2011-03-15

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

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

    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.

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

    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 μSv), followed by AZ3000CT (332.4 μSv), Somatom Emotion 6 (199.38 μSv), and 3D eXaM (111.6 μSv); it was the lowest for Implagraphy (83.09 μSv). 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.

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

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

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

    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.

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

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

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

    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...

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

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

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

    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.

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

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

    2004-01-01

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

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

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

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

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

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

    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

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

    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.

  12. Acute pulmonary embolism in the era of multi-detector CT: a reality in sub-Saharan Africa

    The advantages of multi-detector computed tomography (MDCT) have made it the imaging modality of choice for some patients with suspected cardiothoracic disease, of which pulmonary embolism (PE) is an exponent. The aim of this study was to assess the incidence of PE in patients with clinical suspicion of acute PE using MDCT in a sub-Saharan setting, and to describe the demographic characteristics of these patients. Consecutive records of patients who underwent MDCT pulmonary angiography for suspected acute PE over a two-year period at the Radiology Department of a university-affiliated hospital were systematically reviewed. All MDCT pulmonary angiograms were performed with a 16-detector computed tomography (CT) scanner using real-time bolus tracking technique. Authorization for the study was obtained from the institutional authorities. Forty-one MDCT pulmonary angiograms were reviewed of which 37 were retained. Of the 4 excluded studies, 3 were repeat angiograms and 1 study was not technically adequate. Twelve of 37 patients (32.4%) had CT angiograms that were positive for PE, of which 7 were males. The mean age of these patients was 47.6±10.5 years (age range from 33 to 65 years). Twenty five patients out of 37 (67.6%) had CT angiograms that were negative for PE. Eleven PE-positive patients (91.7%) had at least 1 identifiable thromboembolic risk factor whilst 5 PE-negative patients (20%) also had at least a thromboembolic risk factor. The relative risk of the occurrence of PE in patients with at least a thromboembolic risk factor was estimated at 14.4. Acute PE is a reality in sub-Saharan Africa, with an increased likelihood of MDCT evidence in patients with clinical suspicion of PE who have at least a thromboembolic risk factor. The increasing availability of MDCT will help provide more information on the occurrence of PE in these settings

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

    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.)

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

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

    2008-07-15

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

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

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

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

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

    2010-07-15

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

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

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

  18. Morphometric evaluation of subaxial cervical spine using multi-detector computerized tomography (MD-CT) scan: the consideration for cervical pedicle screws fixation

    Chanplakorn, Pongsthorn; Kraiwattanapong, Chaiwat; Aroonjarattham, Kitti; Leelapattana, Pittavat; Keorochana, Gun; Jaovisidha, Suphaneewan; Wajanavisit, Wiwat

    2014-01-01

    Background Cervical pedicle screw (CPS) insertion is a technically demanding procedure. The quantitative understanding of cervical pedicle morphology, especially the narrowest part of cervical pedicle or isthmus, would minimize the risk of catastrophic damage to surrounding neurovascular structures and improve surgical outcome. The aim of this study was to investigate morphology and quantify cortical thickness of the cervical isthmus by using Multi-detector Computerized Tomography (MD-CT) sca...

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

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

    2016-04-01

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

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

    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

  1. The study of multi-detector CT on the grouping and measuring of the hepatic veins

    Objective: To study the three-dimensional topography of the hepatic vein (HV), the inferior vena cava(IVC) and the inferior right hepatic vein(IRHV) in the retrohepatic and pre-IVC tunnel in human beings, and to provide an anatomic reference for liver surgery. Methods: One hundred and ten volunteers underwent CT scanning at 60 to 75 s after injection of contrast medium, and their HV, IVC and IRHV were reconstructed into MPR and 3D-MIP images. The hepatic veins were grouped according to the way by which the hepatic vein enters IVC. The angle between the right hepatic vein and the middle hepatic vein or the trunk of hepatic vein was measured, and the width from right hepatic vein to middle hepatic vein or to the trunk of hepatic vein on IVC was recorded. The frequency of IRHV was observed, and the length of the tunnel was measured. Results: Among the 110 volunteers, there were 6 cases (5.45%) with three hepatic veins respectively entering IVC, 98 cases (89.10%) with right hepatic vein and a common trunk of the middle hepatic vein and the left hepatic vein entering IVC, and 6 cases (5.45%) with left hepatic vein and a common trunk of the right hepatic vein and the middle hepatic vein entering IVC. The mean value of the angles between the right hepatic vein and the middle hepatic vein or the mink of hepatic vein was (55 ± 18) degree. The width from the right hepatic vein to the middle hepatic vein or to the trunk of hepatic vein was (21 ± 7)mm. The IRHV was observed in 30 cases(27.27%). The mean value of the tunnel length was (53 ± 11) mm. Conclusion: The parameters of the retrohepatic and pre-IVC tunnel in human beings can be measured accurately by the imaging of MPR, which can provide an anatomic reference for the liver surgery. (authors)

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

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

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

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

    2006-05-15

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

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

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

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

    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.

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

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

    2012-03-15

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

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

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

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

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

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

    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.

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

    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

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

    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.

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

    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

  13. Preoperative Gross Classification of Gastric Adenocarcinoma: Comparison of Double Contrast-Enhanced Ultrasound and Multi-Detector Row CT.

    Yan, Caoxin; Bao, Xiaofeng; Shentu, Weihui; Chen, Jian; Liu, Chunmei; Ye, Qin; Wang, Liuhong; Tan, Yangbin; Huang, Pintong

    2016-07-01

    The aim of this study was to compare the accuracy of multi-detector computed tomography (MDCT) with double contrast-enhanced ultrasound (DCEUS), in which intravenous microbubbles are used alongside oral contrast-enhanced ultrasound, in determining the gross classification of patients with gastric carcinoma (GC). Altogether, 239 patients with GC proved by histology after endoscopic biopsy were included in this study. DCEUS and MDCT were performed pre-operatively. The diagnostic accuracies of DCEUS and MDCT in determining the gross classification were calculated and compared. The overall accuracy of DCEUS in determining the gross appearance of GC was higher than that of MDCT (84.9% vs. 79.9%, p cancer (χ(2), p = 0.323 for Borrmann type I, p = 0.141 for Borrmann type IV). The accuracy of DCEUS for early GC and Borrmann II and III classifications of GC was higher than that of MDCT (χ(2), p = 0.000 for all). DCEUS may be regarded as a valuable complementary tool to MDCT in determining the gross appearance of gastric adenocarcinoma pre-operatively. PMID:27072076

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

    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

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

    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.)

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

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

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

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

    2016-05-01

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

  18. Multi-Detector CT Findings of the Normal Appendix in Children: Evaluation of the Position, Diameter, and Presence or Absence of Intraluminal Gas

    Park, Woon Ju; Kim, Jong Chul [Dept. of Radiology, Chungnam National University College of Medicine, Daejeon (Korea, Republic of)

    2011-08-15

    To assess the usefulness of multi-detector CT (MDCT) with multiplanar reformations (MPR) for the evaluation of the position, diameter and presence or absence of intraluminal gas in the normal appendix in children. From 2007 to 2010, we retrospectively analyzed the MDCT images of normal appendices in 133 children, and evaluated the position, diameter, and presence or absence of intraluminal gas in the appendix. Among the 133 appendices, type I (postileal and medial paracecal position) was found in 64 children, type II (subcecal position) in 22, type III (retrocecal and retrocolic/laterocolic position) in 15, type IV (preileal and medial colic position) in 16, and type V (lower pelvic position) in 16 children. The mean diameter was 5.8 mm {+-} 1.2 (SD) (range; 3.2-8.7 mm). There was a high correlation between the appendiceal diameter and age (p = 0.000).There was no statistically significant difference in the appendiceal diameter between boys and girls (p = 0.470). Intraluminal gas was found in 115 appendices and there was no statistically significant correlation between the appendiceal diameter and intraluminal gas (p = 0.502). The MDCT with MPR was useful for the evaluation of the normal appendices in children. The procedure may be useful for the diagnosis of equivocal or unusual appendicitis in children.

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

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

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

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

    2011-07-15

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

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

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

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

    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.

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

    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.)

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

    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.)

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

    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.)

  6. Assessment of a CT image of the oral cavity with use of an aid focusing on a neck examination

    Lee, Hyo-Jong; Goo, Eun-Hoe; Kim, Sung-Soo; Dong, Kyung-Rae; Chung, Woon-Kwan

    2013-11-01

    The aim of this study was to provide clinical information on an oral cavity disease assessment that was conducted using a self-manufactured aid in a computed tomography (CT) oral examination. The study subjects included 30 patients, who were examined using a multi-detector CT (MDCT) 128-slice CT Scanner. Rapidia software was used for quantitative analysis, while a questionnaire and qualitative analysis were used to assess the convenience. The significance was evaluated using a Student's t-test and a Wilcoxon signed rank test. A p value oral cavity. In particular, the patients considered the use of the aid to be convenient. Overall, the aid is recommended for use in a head/neck examination.

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

    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

  8. 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

    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

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

    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.

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

    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

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

    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.

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

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

  13. Pulmonary malignant focal ground-glass opacity nodules and solid nodules of 3 cm or less: comparison of multi-detector CT features

    To evaluate the different multi-detector computed tomography (MDCT) features between pulmonary malignant focal ground-glass opacity (fGGO) nodules and solid nodules of 3 cm or less in diameter. One hundred and five malignant solid nodules and 48 malignant fGGOs confirmed by pathology were retrospectively analysed with regard to the patient's demographic data, nodule size and MDCT features (shape, margin, interface, internal characteristics and adjacent structure). Differences were analysed using the Fisher exact test or Mann–Whitney U-test. The male to female ratio of patients with malignant solid nodules (60:45) was higher than that with malignant fGGOs (18:30) (P < 0.05). There was no significant difference in either patient's age (P > 0.05) or nodule size (P > 0.05). The frequency of irregular shape (4% vs. 21%), spiculation (57% vs. 40%), vacuole sign (11% vs. 52%) and natural air bronchograms (0% vs. 24%) was significantly different between malignant solid nodules and fGGOs. No differences were found in the frequency of lobulation, cusp angle, spine-like process, interface and adjacent structure between the two groups (P > 0.05). Malignant fGGOs and solid nodules showed mostly similar MDCT features. For malignant fGGOs, the frequency of irregular shape, vacuole sign and natural air bronchograms was higher than that in solid nodules, but the frequency of spiculation was lower than that in solid nodules.

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

    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.)

  15. Assessment of right ventricular dysfunction and the metergasis before and after therapy of thrombolysis with electrocardiography gated multi-detector spiral CT in acute pulmonary embolism

    Objective: To prospectively assess right ventricular dysfunction and the metergasis before and after therapy of thrombolysis with ECG gated multi-detector spiral computed tomography (MSCT) in patients with acute pulmonary embolism. Methods: Triple rule-out ECG gated MSCT examination was performed in 96 consecutive patients suspected of PE. 25 patients with central PE were confirmed. 25 age- matched subjects without cardiac and pulmonary disease were recruited as control group. Triple rule-out ECG gated MSCT were performed again to assess cardiac function after therapy of thrombolysis. Dimension ratios for the right ventricle (RV) and left ventricle (LV), main pulmonary artery and aorta were measured. Furthermore, the RV and LV end-diastolic volumes (EDV), end-systolic volume (ESV) and ejection fraction (EF) were also measured. The mean values were compared with analysis of variance (ANOVA) and Newman-Keuls test before and after thrombolysis. Results: The mean values of RVEDV, RVESV, RVEF, RV/LV ESV volume ratio, RV/LV dimension ratio and main pulmonary artery/aorta dimension ratio in control group were (150.5±24.1) ml, (71.5±18.5) ml, (53.5±4.2)%, 1.08±0.04, 1.01±0.04 and 0.99±0.02, respectively. While those in PE group were (190.3±16.2) ml, (128.1±13.2) ml, (32.7±3.6)%, 2.00±0.26, 1.30±0.09 and 1.34±0.11, respectively. Those after therapy of thrombolysis were (159.2±21.5) ml, (80.7±9.4) ml, (49.2±5.9)%, 1.22±0.25, 1.02±0.02 and 1.02±0.11, respectively. ESV and EDV of RV were larger (q=6.28, P<0.01; q=7.59, P<0.01), EF value was lower (q=4.82, P<0.01) in PE group than those in control group. RV/LV ESV volume ratio, the RV/LV dimension ratio and main pulmonary artery/aorta dimension ratio were larger (q=6.04, P<0.01; q=4.43, P<0.01; q=4.36, P<0.01) and EDV of LV was lower in PE group than those in control group. However, ESV and EDV of RV and RV/LV ESV volume ratio were lower (q=5.03, P< 0.01; q=6.11, P<0.01; q=4.74, P<0.01), EF value was larger (q

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

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

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

    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 mAseff) 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 quality.

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

    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.

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

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

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

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

    2006-12-15

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

  1. Dual-source 128-slice MDCT neck: Radiation dose and image quality estimation of three different protocols

    Purpose: To estimate the radiation dose and image quality of single-source (SSCT), high-pitch (HPCT), and dual-energy (DECT) protocols of a dual-source CT (DSCT) system for the examination of neck. Materials and methods: 180 patients were randomized to one of the three protocols: 60 patients (age: 55.4 ± 12 years; range: 44–84 years) were examined with a SSCT, other 60 (59.5 ± 16.4years; R: 40–85) with HPCT, and the last 60 (61.1 ± 14.9 years; R: 47–84) were examined with a DECT protocol. All examinations were performed using a DSCT system. The used protocols: Group-1 (SSCT: 120 kV; effective mAs: 185.4 ± 17.7), Group-2 (HPCT: 120 kV; eff. mAs: 97.7 ± 11.8), and Group-3 (DECT: 80 kV/140 kV with tin-filter; eff. mAs: 248.5 ± 25.7; 187 ± 21.2). A 100 ml iomeprol non-ionic contrast material was injected in to the patients during examination. Results: Insignificant results were yielded regarding SNR and CNR between the groups (group-1 vs. 2: 0.3125, group-1 vs. 0.6W: 0.6875, group-2 vs. 0.6W: 0.3125), except DECT-80 (group-1 vs. 80 kV: 0.04289, group-2 vs. 80 kV: 0.025, group-0.6W vs.80 kV: 0.04567) and 140 kV data, moreover, qualitative analysis yielded the same results. Mean effective-dose was significantly lower (p < 0.05) in group-2 (1.06 ± 0.16 mSv) compared to group-1 (2.05 ± 0.22 mSv) or group-3 (1.76 ± 0.2 mSv). Single- and dual-energy comparison showed a significant difference (group-1 vs. 3: p = 0.00001 and group-2 vs. 3: p = 0.00001) for CTDIvol (percent difference: 16%, 64%) or DLP (PD: 15.5%, 50.5%). Conclusion: Quantitative and qualitative analysis showed similar results for SSCT, HPCT, and DECT-0.6W datasets regarding quality. HPCT yielded lower dose compared to other groups, however, the DECT achieved a lower and significant dose difference from the SSCT protocol. HPCT and DECT can be used with similar image quality and lower radiation dose compared to SSCT for the scans and can be utilized to various clinical advantages

  2. Instrumentation for multi-detector arrays

    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.

  3. 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

    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)

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

    赵刚; 查云飞; 王弘; 洪玮; 邱晓明; 王珍; 肖友梅

    2013-01-01

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

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

    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.)

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

    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.)

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

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

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

    In April 2006, a new affiliated hospital opened at Nihon University School of Dentistry at Matsudo, and the latest model was introduced into the department of radiology. CT examinations for preoperative dental implant going on 64 multi-detector row CT, the number of cases has increased. CT examination is useful for preoperative dental implant, and many studies of concerning clinical studies using CT images have been reported. The purpose of this study was to the clinico-statistical studies of preoperative CT examinations for dental implant at our radiology department using 64 multi-detector row CT. The subjects consisted of 5174 regions in 1312 cases of preoperative CT examinations, between April 2006 and December 2007. CT machine used was the Aquilion TM64 (Toshiba Medical Systems, Japan), and the workstation used was the ZIOSTATION (ZIOSOFT, Japan). All of CT examinations were performed the position of implant placement and disease examined from CT findings. The following results were obtained: The 1312 cases consisted of 426 males and 886 females. Patient age ranged from 16 yrs to 86 yrs old, the average age were 55.5 yrs old. Six hundred and seventy four cases were ordered at another private dental office not our hospital, and 638 cases were ordered at our hospital. The numbers of implant placement were on the average of 3.9, and the rate got higher with age. The lesions which detected by preoperative CT examination were maxillary sinusitis, periodontitis, ectopic calcification, and mucous retention cyst. (author)

  9. Data acquisition for experiments with multi-detector arrays

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

    2001-07-01

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

  10. Normal mediastinal and hilar lymph nodes in children on multi-detector row chest computed tomography

    To study normal mediastinal and hilar lymph nodes on multi-detector chest computed tomography (CT). A cohort of 120 children aged 1-17 years underwent emergency CT, including the chest, after high-energy trauma. Axial 5-mm reconstructions were evaluated for lymph nodes at hilar and various mediastinal levels and the short-axis diameters were measured. At least one lymph node was found in 115 (96%) children, with subcarinal (69%), lower paratracheal (64%) and hilar (60%) nodes being most common. Up to 10 years of age most lymph nodes were smaller than or equal to 7 mm. In older children lymph nodes measuring up to 10-mm-short-axis diameter were found. Lymph nodes were rare along the mammary vessels, at lower oesophageal and at prevascular and posterior mediastinal levels in children. Mediastinal and hilar lymph nodes are more common than previously thought, probably because of increased detection by modern multi-detector CT. Lymph node location and age have to be taken into account when evaluating lymph nodes in the paediatric chest. (orig.)

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

    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

  12. 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

    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

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

    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

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

    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.

  15. Neutron multi-detector system: mutual influence of its modules

    A position-sensitive neutron detector (PSND) has been designed and tested as a module of a multi-detector array. ''Cross-talk'' effects, contributing a major distortion factor for all closely packed neutron detector systems, have been measured. It was established, using neutrons from the spontaneous fission of 252Cf (setting neutron energy threshold at 0.7 MeV), that the distortions of neutron energy and of neutron angular distribution are insignificant (within the level of statistical accuracy). The influence of cross-talk on the coincidence counting rate was measured to range from 48% to 16% for distances between detector's axes of 12 to 24 cm. ((orig.))

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

    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

  17. Dose and image quality of high-pitch dual source computed tomography for the evaluation of cervical lymph node status – Comparison to regular 128-slice single source computed tomography

    Purpose: A high-pitch dual-source CT (DSCT) was compared to a standard single-source CT protocol in terms of dose and image quality for malignant lymphoma staging. Materials and methods: Data from 43 patients who underwent DSCT (group 1) of the neck for staging of malignant lymphoma and 40 patients who underwent regular single source CT (group 2) were investigated retrospectively. Volume CT dose index (CTDIvol), dose length product (DLP), background noise (BN), attenuation values, signal-to-noise-ratio (SNR), scan time, effective tube current-time product (eff. mAs), subjective diagnostic image quality and artifact burden were compared. Results: CTDIvol (5.5 ± 0.8 mGy vs. 12.4 ± 1.4 mGy), DLP (172 ± 27 mGycm vs. 344 ± 60 mGycm, p < 0.0001), eff. mAs (98 ± 15 mAs vs. 183 ± 20 mAs, p < 0.0001) and scan time (0.64 ± 0.05 s vs. 8.21 ± 0.72 s) were lower for group 1. BN was higher (p < 0.001) for group 1 with a mean difference of 2.6 HU. SNR for sternocleidomastoid and pectoral muscle was lower (6.6–12.3 vs. 7.8–19.1) for group 1. Subjective image quality (1.55 ± 0.6 vs. 1.42 ± 0.5) and artifact burden (1.62 ± 1.0 vs. 1.57 ± 0.9) were not rated significantly different (p = 0.47 and p = 0.80) with a good inter-observer agreement (κ = 0.59–0.90). Conclusion: High-pitch DSCT allows reduction of patient dose for cervical lymphoma staging while diagnostic image quality is preserved

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

    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

  19. A Multicenter, Open-Label Study of an Intravenous Short-Acting β1-Adrenergic Receptor Antagonist Landiolol Hydrochloride for Coronary Computed Tomography Angiography by 16-Slice Multi-Detector Computed Tomography in Japanese Patients with Suspected Ischemic Cardiac Disease

    Hirano, Masaharu; Yamashina, Akira; Hara, Kazuhiro; Ikari, Yuji; Jinzaki, Masahiro; Iino, Misako; Yamaguchi, Takuhiro; Tanimoto, Mitsunobu; Kuribayashi, Sachio; ,

    2014-01-01

    Background During coronary computed tomography (CT) angiography (CCTA), β-blockers (β-adrenergic receptor antagonists) have commonly been used to lower heart rate and improve image quality. Objectives The aim of this study was to investigate the image quality-improving effect as well as the heart rate-lowering effect of landiolol hydrochloride (an intravenous short-acting β1-adrenergic receptor antagonist) in CCTA by 16-slice multi-detector CT (MDCT). Methods A total of 39 subjects suspected ...

  20. Australian diagnostic reference levels for multi detector computed tomography

    The Australian Radiation Protection and Nuclear Safety Agency (ARPANSA) is undertaking web based surveys to obtain data to establish national diagnostic reference levels (DRLs) for diagnostic imaging. The first set of DRLs to be established are for multi detector computed tomography (MDCT). The survey samples MDCT dosimetry metrics: dose length product (DLP, mGy.cm) and volume computed tomography dose index (CTDIvol, mGy), for six common protocols/habitus: Head, Neck, Chest, AbdoPelvis, ChestAbdoPelvis and Lumbar Spine from individual radiology clinics and platforms. A practice reference level (PRL) for a given platform and protocol is calculated from a compliant survey containing data collected from at least ten patients. The PRL is defined as the median of the DLP/CTDIvol values for a single compliant survey. Australian National DRLs are defined as the 75th percentile of the distribution of the PRLs for each protocol and age group. Australian National DRLs for adult MDCT have been determined in terms of DLP and CTDIvol. In terms of DLP the national DRLs are 1,000 mGy cm, 600 mGy cm, 450 mGy cm, 700 mGy cm, 1,200 mGy cm, and 900 mGy cm for the protocols Head, Neck, Chest, AbdoPelvis, ChestAbdoPelvis and Lumbar Spine respectively. Average dose values obtained from the European survey Dose Datamed I reveal Australian doses to be higher by comparison for four out of the six protocols. The survey is ongoing, allowing practices to optimise dose delivery as well as allowing the periodic update of DRLs to reflect changes in technology and technique.

  1. Inter-scan reproducibility of coronary calcium measurement using Multi Detector-Row Computed Tomography (MDCT)

    Purpose. To assess inter-scan reproducibility of coronary calcium measurements obtained from Multi Detector-Row CT (MDCT) images and to evaluate whether this reproducibility is affected by different measurement protocols, slice thickness, cardiovascular risk factors and/or technical variables.Design. Cross-sectional study with repeated measurements. Materials and methods. The study population comprised 76 healthy women. Coronary calcium was assessed in these women twice in one session using 16-MDCT (Philips Mx 8000 IDT 16). Images were reconstructed with 1.5 mm slice thickness and 3.0 mm slice thickness. The 76 repeated scans were scored. The Agatston score, a volume measurement and a mass measurement were assessed. Reproducibility was determined by estimation of mean, absolute, relative difference, the weighted kappa value for agreement and the Intra-class correlation coefficient (ICCC).Results. Fifty-five participants (72.4%) had a coronary calcification of more than zero in Agatston (1.5 mm slice thickness). The reproducibility of coronary calcium measurements between scans in terms of ranking was excellent with Intra-class correlation coefficients of >0.98, and kappa values above 0.80. The absolute difference in calcium score between scans increased with increasing calcium levels, indicating that measurement error increases with increasing calcium levels. However, no relation was found between the mean difference in scores and calcium levels, indicating that the increase in measurement error is likely to result in random misclassification in calcium score. Reproducibility results were similar for 1.5 mm slices and for 3.0 mm slices, and equal for Agatston, volume and mass measurements.Conclusion. Inter-scan reproducibility of measurement of coronary calcium using images from MDCT is excellent, irrespective of slice thickness and type of calcium parameter

  2. 64排探测器CT冠状动脉成像对心肌桥伴冠心病的诊断价值探讨%Diagnositic value of 64 multi-detector rows CT coronary angiography in myocardial bridge and coronal artery disease

    刘静; 周茂义; 杨春波; 李立新; 赵兴圣; 岳奎涛; 邵伟光

    2009-01-01

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

  3. Automated attenuation-based tube voltage selection for body CTA: Performance evaluation of 192-slice dual-source CT

    Winklehner, Anna; Gordic, Sonja; Lauk, Eliane; Frauenfelder, Thomas; Alkadhi, Hatem; Husarik, Daniela B. [University Hospital Zurich, Institute for Diagnostic and Interventional Radiology, Zurich (Switzerland); Leschka, Sebastian [University Hospital Zurich, Institute for Diagnostic and Interventional Radiology, Zurich (Switzerland); Division of Radiology and Nuclear Medicine, St. Gallen (Switzerland)

    2015-08-15

    To assess radiation dose and image quality in body CT-angiography (CTA) with automated attenuation-based tube voltage selection (ATVS) on a 192-slice dual-source CT (DSCT). Forty patients (69.5 ± 9.6 years) who had undergone body CTA with ATVS (ref.kVp 100, ref.mAs 90) using a 2x192-slice CT in single-source mode were retrospectively included. All patients had undergone prior CTA with a 2x128-slice CT and ATVS with identical imaging and contrast media protocols, serving for comparison. Images were reconstructed with iterative reconstruction at similar strength levels. Radiation dose was determined. Image quality was assessed semi-quantitatively (1:excellent, 5:non-diagnostic), aortic attenuation, noise and CNR were determined. As compared to 128-slice DSCT, 192-slice DSCT selected tube voltages were lower in 30 patients (75 %), higher in 3 (7.5 %), and similar in 7 patients (17.5 %). CTDI{sub vol} was lower with 192-slice DSCT (4.7 ± 1.9 mGy vs. 5.8 ± 2.1 mGy; p < 0.001). Subjective image quality, mean aortic attenuation (342 ± 67HU vs. 268 ± 67HU) and CNR (9.8 ± 2.5 vs. 8.2 ± 2.9) were higher with 192-slice DSCT (all p < 0.01), all datasets being diagnostic. Our study suggests that ATVS of 192-slice DSCT for body CTA is associated with an improved image quality and further radiation dose reduction of 19 % compared to 128-slice DSCT. (orig.)

  4. Automated attenuation-based tube voltage selection for body CTA: Performance evaluation of 192-slice dual-source CT

    To assess radiation dose and image quality in body CT-angiography (CTA) with automated attenuation-based tube voltage selection (ATVS) on a 192-slice dual-source CT (DSCT). Forty patients (69.5 ± 9.6 years) who had undergone body CTA with ATVS (ref.kVp 100, ref.mAs 90) using a 2x192-slice CT in single-source mode were retrospectively included. All patients had undergone prior CTA with a 2x128-slice CT and ATVS with identical imaging and contrast media protocols, serving for comparison. Images were reconstructed with iterative reconstruction at similar strength levels. Radiation dose was determined. Image quality was assessed semi-quantitatively (1:excellent, 5:non-diagnostic), aortic attenuation, noise and CNR were determined. As compared to 128-slice DSCT, 192-slice DSCT selected tube voltages were lower in 30 patients (75 %), higher in 3 (7.5 %), and similar in 7 patients (17.5 %). CTDIvol was lower with 192-slice DSCT (4.7 ± 1.9 mGy vs. 5.8 ± 2.1 mGy; p < 0.001). Subjective image quality, mean aortic attenuation (342 ± 67HU vs. 268 ± 67HU) and CNR (9.8 ± 2.5 vs. 8.2 ± 2.9) were higher with 192-slice DSCT (all p < 0.01), all datasets being diagnostic. Our study suggests that ATVS of 192-slice DSCT for body CTA is associated with an improved image quality and further radiation dose reduction of 19 % compared to 128-slice DSCT. (orig.)

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

    刘静; 周茂义; 杨春波; 李丽新; 赵兴圣; 邵伟光; 岳奎涛

    2008-01-01

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

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

    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...

  7. Development of the third generation ICT multi-detector sub-step equipment

    The multi-detector sub-step equipment, realizing the interpolation movement of the detector system, has been developed for studying the third generation industrial computed tomography (ICT). The projection data of size 1024 x 1024 can be gotten by 15 interpolation operations of the detector system when the number of detector array is 64. (authors)

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

    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)

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

    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

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

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

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

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

    2009-06-01

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

  12. Validation of optimal coronary angiography angle for the branch form of the left main trunk by use of multi detector computed tomography

    The aim of this study was to derive optimal coronary angiography (CAG) angle for the form information on the left main trunk (LMT) by use of multi detector computed tomography (MDCT). To verify the accuracy of angle measurement with MDCT, the angle of phantom with known angle was compared with MDCT (CT method) and angiography (AG method). The take-off angle of LMT was derived using CT method from 200 cases who underwent cardiac CT in this institution. In the phantom, both CT and AG methods were indicated to have high accuracy and the errors were very small (0.3%, 0.3%). The take-off mean angle of LMT was 130.7±19.0 degrees in male, and 139.1±19.3 degrees in female. The optimal CAG angle was indicated at left anterior oblique (LAO) 41 degrees (male) and LAO 49 degrees (female). The optimal CAG angle of LMT was derived from the CT method. (author)

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

    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)

  14. Form reappearance of the section sensitivity profile on Z-axis in multi-detector spiral computed tomography

    The filter is hung in the direction of slice thickness (Z-axis) in the reconstruction of multi-detector spiral CT. Because of this, performing several time scans is considered useful from the standpoint of reappearance of the section sensitivity profile curves. However, when examination is done at full width half maximum (FWHM) and the position of the center of FWHM, there is non-symmetry and the level of hem extent of the section sensitivity profile curves. Change in FWHM and the position of the center of FWHM increases as pitch increases. Although the change in FWHM was less when the reconstruction slice thickness was increased, the change became larger in the center of FWHM as well. As for the non-symmetry of the section sensitivity profile curves and the level of hem extent, the change decreased when the reconstruction slice thickness was increased, although it increased when pitch was enlarged. It is considered that the cause of these changes is change in table movement speed during scanning. (author)

  15. Identifying the most infectious lesions in pulmonary tuberculosis by high-resolution multi-detector computed tomography

    This study aimed to determine whether characteristics detected by multi-detector computed tomography (MDCT) were predictive of highly infectious, smear-positive, active pulmonary tuberculosis (PTB). Among 124 patients with active PTB, 84 had positive (group 1) and 40 had negative (group 2) smear results for acid-fast bacilli. Multiplanar MDCT, axial conventional CT and chest X-ray images were analysed retrospectively for morphology, number, and segmental (lobe) distribution of lesions. By multivariate analysis, consolidation over any segment of the upper, middle, or lingual lobes, cavitations, and clusters of nodules were associated with group 1, while centrilobular nodules were predictive of group 2. Using five independent variables associated with risk in group 1, a prediction model was created to distinguish between group 1 and group 2. ROC curve analysis showed an area under the curve of 0.951 ± 0.021 for this prediction model. With the ideal cutoff point score of 1, the sensitivity, specificity, and positive predictive values were 84.5%, 97.5%, and 98.0%, respectively. A model to predict smear-positive active PTB on the basis of findings from MDCT may be a useful tool for clinical decisions about isolating patients pending sputum smear results. (orig.)

  16. Identifying the most infectious lesions in pulmonary tuberculosis by high-resolution multi-detector computed tomography

    Yeh, Jun Jun [Pingtung Christian Hospital, Pingtung (China); Mei-Ho Institute of Technology, Pingtung (China); China Medical University, Taichung (China); Chen, Solomon Chih-Cheng [Pingtung Christian Hospital, Pingtung (China); National Taiwan University, Institute of Occupational Medicine and Industrial Hygiene, College of Public Health, Taipei (China); Teng, Wen-Bao; Chou, Chun-Hsiung; Hsieh, Shih-Peng; Lee, Tsung-Lung [Pingtung Christian Hospital, Pingtung (China); Wu, Ming-Ting [National Yang Ming University, Faculty of Medicine, School of Medicine, Taipei (China); Kaohsiung Veterans General Hospital, Section of Thoracic and Circulation Imaging, Department of Radiology, Kaohsiung (China)

    2010-09-15

    This study aimed to determine whether characteristics detected by multi-detector computed tomography (MDCT) were predictive of highly infectious, smear-positive, active pulmonary tuberculosis (PTB). Among 124 patients with active PTB, 84 had positive (group 1) and 40 had negative (group 2) smear results for acid-fast bacilli. Multiplanar MDCT, axial conventional CT and chest X-ray images were analysed retrospectively for morphology, number, and segmental (lobe) distribution of lesions. By multivariate analysis, consolidation over any segment of the upper, middle, or lingual lobes, cavitations, and clusters of nodules were associated with group 1, while centrilobular nodules were predictive of group 2. Using five independent variables associated with risk in group 1, a prediction model was created to distinguish between group 1 and group 2. ROC curve analysis showed an area under the curve of 0.951 {+-} 0.021 for this prediction model. With the ideal cutoff point score of 1, the sensitivity, specificity, and positive predictive values were 84.5%, 97.5%, and 98.0%, respectively. A model to predict smear-positive active PTB on the basis of findings from MDCT may be a useful tool for clinical decisions about isolating patients pending sputum smear results. (orig.)

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

    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...

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

    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...

  19. 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

    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

  20. Contribution to data acquisition software of Eurogram and Diamant multi detectors in an Unix/VXWorks environment

    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

  1. Multidetector-row CT for spinal diseases

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

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

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

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

    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.)

  4. Multi detector computed tomography (MDCT) of the aortic root; ECG-gated verses non-ECG-gated examinations

    Purpose: Motion artifacts may degrade a conventional CT examination of the ascending aorta and hinder accurate diagnosis. We quantitatively compared retrospectively electrocardiographic (ECG) -gated multi detector computed tomography (MDCT) with non-ECG-gated MDCT in order to demonstrate whether or not one of the methods should be preferred. Method: The study included seventeen patients with surgically reconstructed aortic root and reimplanted coronary arteries. All patients had undergone both non-gated MDCT and retrospectively ECG-gated MDCT employing a stringently modulated tube current with single phase image reconstruction. The incidence of motion artifacts in the left main coronary artery (LM), proximal right coronary artery (RCA), and aortic root and ascending aorta were rated using a four point scale. The effective dose for each scan was calculated and normalized to a 15 cm scan length. Statistical analysis of motion artifacts and radiation dose was performed using Wilcoxon matched pairs signed rank sum test. Results: A significant reduction in motion artifacts was found in all three vessels in images from the retrospectively ECG-gated scans (LM: P = 0.005, RCA: P = 0.015, aorta: P = 0.003). The mean normalized effective radiation dose was 3.69 mSv (±1.03) for the non-ECG-gated scans and 16.37 mSv (±2.53) for the ECG-gated scans. Conclusion: Retrospective ECG-gating with single phase reconstruction significantly reduces the incidence of motion artifacts in the aortic root and the proximal portion of the coronary arteries but at the expense of a fourfold increase in radiation dose.

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

    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.

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

    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.)

  7. Efficiency corrections for the γ-γ coincidence counting rates measured by the multi-detector correlation system

    A new method of determination of the efficiency corrections for the γ-γ coincidence rates measured by the multi-detector system is described. The method uses the random coincidence counting rates and is based on two assumptions: a) the counting rates of both true and random coincidences for a given pair of γ-quanta are proportional to the efficiencies of the registration of γ-quanta in the detectors; b) there is no correlation between the gammas which coincide at random. Results of the test of the method applied to the multi-detector correlation system are presented. (orig.)

  8. 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

    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.

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

    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.)

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

    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...

  11. Collimated prompt gamma TOF measurements with multi-slit multi-detector configurations

    Longitudinal prompt-gamma ray profiles have been measured with a multi-slit multi-detector configuration at a 75 MeV/u 13C beam and with a PMMA target. Selections in time-of-flight and energy have been applied in order to discriminate prompt-gamma rays produced in the target from background events. The ion ranges which have been extracted from each individual detector module agree amongst each other and are consistent with theoretical expectations. In a separate dedicated experiment with 200 MeV/u 12C ions the fraction of inter-detector scattering has been determined to be on the 10%-level via a combination of experimental results and simulations. At the same experiment different collimator configurations have been tested and the shielding properties of tungsten and lead for prompt-gamma rays have been measured

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

    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

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

    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.

  14. Anatomical characteristics of myocardial bridge in patients with myocardial infarction by multi-detector computed tomography

    Recent development of multi-detector computed tomography (MDCT) has made the detection of myocardial bridge (MB) easier on the left anterior descending coronary artery (LAD). The LAD segment proximal to the MB is well known to be susceptible to atherosclerosis. Anatomical characteristics of MB on LAD in patients with myocardial infarction (MI) were examined by MDCT. Subjects were 43 MI patients who had MB in the LAD and comprised 2 groups: 14 with culprit lesions in the LAD proximal to MB (culprit group) and 29 without culprit lesions in the LAD (non-culprit group). MB length, MB thickness, and the distance from the orifice of left main trunk (LMT) to MB entrance were compared. Age and coronary risk factors showed no significant difference between the 2 groups. MB length (P=0.011), MB thickness (P=0.035), and index of the length multiplied by thickness of MB (P=0.031) were significantly greater in the culprit group. The distance from the orifice of the LMT to MB entrance was significantly shorter in the culprit group (P=0.006). Anatomical properties of MB, such as length and thickness of MB as well as MB location, are associated with the formation of culprit lesions of LAD proximal to MB in MI. (author)

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

    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)

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

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

    2005-12-15

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

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

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

  18. Chest CT in infants and children

    Computed tomography (CT) is a powerful and irreplaceable imaging technique in the evaluation of thoracic disease in infants and children. Recent advances in CT technology, with multi-detector equipment now widely available in most institutions, allowing a highly detailed evaluation of the chest in a short time period has resulted in expanding indications of chest CT in paediatric patients. Its improved diagnostic yield along with a widespread availability has also resulted in an increased number of CT examinations in children, not always with beneficial impact on patient management and outcome. Accordingly with the ALARA concept, a judicious and correct use of CT is strongly advisable in order to reduce unnecessary high dose radiation exposure. The objective of this paper is to review the use of chest CT in paediatric patients focused mainly on basic technical aspects and clinical applications in the evaluation of the lungs, mediastinum and chest wall

  19. Radiation dose reduction of coronary CT angiography at low tube voltage on an integrated circuit detector with iterative reconstruction

    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 sonogram affirmed iterative reconstruction (SAFIRE) (Subgroup B2). The differences in background noise, signal-to-noise 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 χ2 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

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

    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.

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

    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

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

    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

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

    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

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

    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

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

    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.

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

    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

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

    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...

  8. Correlation between human and model observer performance for discrimination task in CT

    Although physical metrics can objectively characterize computed tomography (CT) image quality, quantitative approaches to predict human observer performance are more accurate and clinically relevant. This study compared a modified channelized Hotelling model observer (CHO) with human observers in a shape discrimination task. Eight lesion-mimicking rods (two contrasts, two sizes and two shapes) were inserted into a 35 × 26 cm2 torso-shaped water phantom and scanned 100 times on a 128-slice CT scanner at five dose levels. CT images were reconstructed using filtered backprojection (FBP) and iterative reconstruction (IR) techniques. Two-alternative forced choice studies were constructed with hexagonal and circular rod images put side-by-side in a randomized order. An edge mask was introduced to CHO to reflect the human observers' emphasis on lesion boundaries in discriminating shape. For small size lesions, the performance of three human observers and the modified CHO was highly correlated across lesion contrasts, CT doses and reconstruction algorithms; while for large size lesions, a ceiling effect was observed for both human and model observers' performance at high doses. Our result suggests the potential of CHO to predict human observer performance for both FBP and IR. For this shape discrimination task with uniform background, IR significantly improved human and model observer performance compared to FBP, with the amount of improvement depending on lesion size, contrast and dose. (paper)

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

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

    2015-01-01

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

  10. Principle and applications of dual source CT

    Flohr, Thomas

    2008-08-01

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

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

    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

  12. Attenuation-based automatic kilovoltage selection and sonogram-affirmed iterative reconstruction: Effects on radiation exposure and image quality of portal-phase liver CT

    To compare the radiation dose and image quality between standard-dose CT and a low-dose CT obtained with the combined use of an attenuation-based automatic kilovoltage (kV) selection tool (CARE kV) and sonogram-affirmed iterative reconstruction (SAFIRE) for contrast-enhanced CT examination of the liver. We retrospectively reviewed 67 patients with chronic liver disease in whom both, standard-dose CT with 64-slice multidetector-row CT (MDCT) (protocol A), and low-dose CT with 128-slice MDCT using CARE kV and SAFIRE (protocol B) were performed. Images from protocol B during the portal phase were reconstructed using either filtered back projection or SAFIRE with 5 different iterative reconstruction (IR) strengths. We performed qualitative and quantitative analyses to select the appropriate IR strength. Reconstructed images were then qualitatively and quantitatively compared with protocol A images. Qualitative and quantitative analysis of protocol B demonstrated that SAFIRE level 2 (S2) was most appropriate in our study. Qualitative and quantitative analysis comparing S2 images from protocol B with images from protocol A, showed overall good diagnostic confidence of S2 images despite a significant radiation dose reduction (47% dose reduction, p < 0.001). Combined use of CARE kV and SAFIRE allowed significant reduction in radiation exposure while maintaining image quality in contrast-enhanced liver CT.

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

    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.

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

    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.

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

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

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

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

    2011-09-15

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

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

    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

  18. Evidence for lower variability of coronary artery calcium mineral mass measurements by multi-detector computed tomography in a community-based cohort-Consequences for progression studies

    Purpose: To compare the measurement variability for coronary artery calcium (CAC) measurements using mineral mass compared with a modified Agatston score (AS) or volume score (VS) with multi-detector CT (MDCT) scanning, and to estimate the potential impact of these methods on the design of CAC progression studies. Materials and methods: We studied 162 consecutive subjects (83 women, 79 men, mean age 51 ± 11 years) from a general Caucasian community-based cohort (Framingham Heart Study) with duplicate runs of prospective electrocardiographically-triggered MDCT scanning. Each scan was independently evaluated for the presence of CAC by four experienced observers who determined a 'modified' AS, VS and mineral mass. Results: Of the 162 subjects, CAC was detected in both scans in 69 (42%) and no CAC was detected in either scan in 72 (45%). Calcium scores were low in the 21/162 subjects (12%) for whom CAC was present in one but not the other scan (modified AS 0.96). However, the mean interscan variability was significantly different between mineral mass, modified AS, and VS (coefficient of variation 26 ± 19%, 41 ± 28% and 34 ± 25%, respectively; p < 0.04), with significantly smaller mean differences in pair-wise comparisons for mineral mass compared with modified AS (p < 0.002) or with VS (p < 0.03). The amount of CAC but not heart rate was an independent predictor of interscan variability (r = -0.638, -0.614 and -0.577 for AS, VS, and mineral mass, respectively; all p < 0.0001). The decreased interscan variability of mineral mass would allow a sample size reduction of 5.5% compared with modified AS for observational studies of CAC progression and for randomized clinical trials. Conclusion: There is significantly reduced interscan variability of CAC measurements with mineral mass compared with the modified AS or VS. However, the measurement variability of all quantification methods is predicted by the amount of CAC and is inversely correlated to the extent of partial

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

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

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

    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.)

  1. X-ray induced DNA double-strand breaks in coronary CT angiography: Comparison of sequential, low-pitch helical and high-pitch helical data acquisition

    Background: Aim of this study was to compare DNA double-strand breaks (DSBs) in blood lymphocytes of patients undergoing high-pitch helical, low-pitch helical and sequential coronary CT angiography. Methods and results: 66 patients were examined with various scan protocols and modes (low-pitch helical scan: 100–120 kV, 320–438 mAs/rot, pitch 0.18–0.39, with or without ECG-pulsing, n = 35; prospectively ECG-triggered high-pitch helical scan: 100–120 kV, 320–456 mAs/rotation, pitch 3.2–3.4, n = 19; prospectively ECG-triggered sequential scan: 100–120 kV, 150–300 mAs or 320–370 mAs/rotation, n = 12) either using a 64-slice or 128-slice dual-source CT or a 128-slice single source CT scanner. Blood samples were obtained before and 30 min after CT and DSBs were analyzed in isolated lymphocytes using γ-H2AX immunofluorescence microscopy. A significant increase of DSBs was measurable 30 min after CTA (range 0.01–0.71/cell). CT induced DSBs showed a significant correlation with the estimated effective dose (ρ = 0.90, p < 0.00001). Both prospectively ECG-triggered sequential (0.10 DSBs/cell, 176 mGy cm, p < 0.00001) and high-pitch helical scan protocols (0.03 DSBs/cell, 109 mGy cm, p < 0.00001) led to a significant reduction of median DLP and DSB levels compared to low-pitch helical scans (0.34 DSBs/cell, 828 mGy cm). A reduction of the tube voltage resulted in significantly lower whereas additional calcium scoring resulted in elevated DLP and DNA damages (p < 0.05 each). Conclusion: In coronary CTA, data acquisition protocols have a significant influence on the X-ray induced DSB levels. Using γ-H2AX immunofluorescence microscopy different scan modes in different CT generations can be compared concerning their biological impact.

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

    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.)

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

    Kuefner, M.A.; Hamann, J.; Lell, Michael; Anders, K.; Schwab, S.A.; Uder, M. [University of Erlangen-Nuernberg, Department of Radiology, Erlangen (Germany); Grudzenski, S.; Loebrich, M. [Darmstadt University of Technology, Radiation Biology and DNA Repair, Darmstadt (Germany); Achenbach, S. [University of Erlangen-Nuernberg, Department of Cardiology, Erlangen (Germany); Haeberle, L. [University of Erlangen-Nuernberg, Department of Medical Informatics, Biometry and Epidemiology, Erlangen (Germany)

    2010-12-15

    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 {gamma}-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 ({rho} = 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 ({rho} = 0.53, p = 0.01) and a negative correlation to the body mass index of the patients ({rho} = -0.37, p = 0.06). {gamma}-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.)

  4. Feasibility of 320-row multi-detector computed tomography angiography to assess bioabsorbable everolimus-eluting vascular scaffolds.

    Asami, Masahiko; Aoki, Jiro; Serruys, Patrick W; Abizaid, Alexandre; Saito, Shigeru; Onuma, Yoshinobu; Kimura, Takeshi; Simonton, Charles A; Tanabe, Kengo

    2016-04-01

    Coronary computer tomographic angiography (CCTA) for screening intra-arterial vessel disease is gaining rapid clinical acceptance in recent years, but its use for such assessments in metal-stented vessel segments is very limited due to blooming artifacts introduced by the metal. However, vessel segments treated by the polymeric everolimus-eluting bioresorbable vascular scaffolds (Absorb) are readily monitored for intravascular disease over time with CCTA. The data on the accuracy of multi-detector computed tomography (MDCT) in patients treated with Absorb is still sparse. Results on 5 Japanese case studies from ABSORB EXTEND are presented here. Five patients were treated with Absorb, and follow-up angiography was conducted at 8 to 14 months as per routine site standard of practice. 320-row MDCT scan was performed within 1 month before the angiography. By MDCT, all Absorb-treated lesions were clearly evaluated and restenosis were not observed. Minimal diameter and % diameter stenosis were similar between MDCT and quantitative angiography (2.07 ± 0.13 vs. 2.03 ± 0.06 mm, P = 0.86, and 22.5 ± 5.0 vs. 21.5 ± 4.5 %, P = 0.88, respectively). MDCT appears to be feasible and useful for evaluating lumen patency and vessel disease in segments implanted with Absorb at follow-up. PMID:26445951

  5. 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

    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.

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

    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.

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

    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...

  8. Technical principles of dual source CT

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

    2008-12-15

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

  9. Volumetric analysis of coronary plaque characterization in patients with metabolic syndrome using 64-slice multi-detector computed tomography

    Metabolic syndrome (MetS) is associated with adverse cardiovascular events and mortality, where acute coronary syndrome significantly impacts on mortality and morbidity. In contrast, evidences have accumulated that the lipid-rich plaque might play a critical role in acute coronary syndrome. The study population consisted of 94 patients with suspected angina pectoris who underwent multi-detector computed tomography (MDCT). Of those, we identified 41 with MetS. In MDCT analysis, low-density plaque volume (LDPV) (42±28 vs 24±18 mm3, P=0.0003), moderate-density plaque volume (105±41 vs 82±33 mm(3), P=0.003), total plaque volume (164±70 vs 118±59 mm3), P=0.0008) and %LDPV (24.2±10.0 vs 18.3±7.1%, P=0.01) were significantly increased in the MetS group compared to the non-MetS group. Multivariate linear regression analysis after adjusting for confounding variables revealed that MetS was significantly correlated with an increase in %LDPV (β=0.48, P=0.0001). Multivariate logistic regression analysis for lipid-rich plaque after adjusting for confounding variables indicated that MetS was significantly associated with lipid-rich plaque (odds ratio: 5.99, 95% confidence intervals: 1.94-18.6, P=0.002). Patients with MetS were strongly related to having a lipid-rich composition in their coronary plaque, as detected by MDCT. (author)

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

    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)

  11. 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

    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.

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

    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

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

    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.

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

    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

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

    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

  16. Topogram-based automated selection of the tube potential and current in thoraco-abdominal trauma CT - a comparison to fixed kV with mAs modulation alone

    Frellesen, Claudia; Stock, Wenzel; Kerl, J.M.; Lehnert, Thomas; Wichmann, Julian L.; Beeres, Martin; Schulz, Boris; Bodelle, Boris; Vogl, Thomas J. [Clinic of the Goethe University, Department of Diagnostic and Interventional Radiology, Frankfurt (Germany); Nau, Christoph; Geiger, Emanuel; Wutzler, Sebastian [Clinic of the Goethe University, Department of Trauma, Hand and Reconstructive Surgery, Frankfurt (Germany); Ackermann, Hanns [Clinic of the Goethe University, Department of Biostatistics and Mathematical Modelling, Frankfurt (Germany); Bauer, Ralf W. [Clinic of the Goethe University, Department of Diagnostic and Interventional Radiology, Frankfurt (Germany); Klinikum der Goethe-Universitaet, Institut fuer Diagnostische und Interventionelle Radiologie, Frankfurt am Main (Germany)

    2014-07-15

    To investigate the impact of automated attenuation-based tube potential selection on image quality and exposure parameters in polytrauma patients undergoing contrast-enhanced thoraco-abdominal CT. One hundred patients were examined on a 16-slice device at 120 kV with 190 ref.mAs and automated mA modulation only. Another 100 patients underwent 128-slice CT with automated mA modulation and topogram-based automated tube potential selection (autokV) at 100, 120 or 140 kV. Volume CT dose index (CTDI{sub vol}), dose-length product (DLP), body diameters, noise, signal-to-noise ratio (SNR) and subjective image quality were compared. In the autokV group, 100 kV was automatically selected in 82 patients, 120 kV in 12 patients and 140 kV in 6 patients. Patient diameters increased with higher kV settings. The median CTDI{sub vol} (8.3 vs. 12.4 mGy; -33 %) and DLP (594 vs. 909 mGy cm; -35 %) in the entire autokV group were significantly lower than in the group with fixed 120 kV (p < 0.05 for both). Image quality remained at a constantly high level at any selected kV level. Topogram-based automated selection of the tube potential allows for significant dose savings in thoraco-abdominal trauma CT while image quality remains at a constantly high level. (orig.)

  17. Topogram-based automated selection of the tube potential and current in thoraco-abdominal trauma CT - a comparison to fixed kV with mAs modulation alone

    To investigate the impact of automated attenuation-based tube potential selection on image quality and exposure parameters in polytrauma patients undergoing contrast-enhanced thoraco-abdominal CT. One hundred patients were examined on a 16-slice device at 120 kV with 190 ref.mAs and automated mA modulation only. Another 100 patients underwent 128-slice CT with automated mA modulation and topogram-based automated tube potential selection (autokV) at 100, 120 or 140 kV. Volume CT dose index (CTDIvol), dose-length product (DLP), body diameters, noise, signal-to-noise ratio (SNR) and subjective image quality were compared. In the autokV group, 100 kV was automatically selected in 82 patients, 120 kV in 12 patients and 140 kV in 6 patients. Patient diameters increased with higher kV settings. The median CTDIvol (8.3 vs. 12.4 mGy; -33 %) and DLP (594 vs. 909 mGy cm; -35 %) in the entire autokV group were significantly lower than in the group with fixed 120 kV (p < 0.05 for both). Image quality remained at a constantly high level at any selected kV level. Topogram-based automated selection of the tube potential allows for significant dose savings in thoraco-abdominal trauma CT while image quality remains at a constantly high level. (orig.)

  18. 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

    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.

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

    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.

  20. Agreement between multi-detector-row CT angiography and US-ECD in quantification of carotid artery stenosis and plaque characterization

    Sameh Abd El Raouf

    2014-03-01

    Conclusion: We observed a good agreement between US-ECD and MDCTA in the quantification of carotid artery stenosis and the assessment of plaque type. There was, however, a poor agreement in the evaluation of plaque ulceration. The use of US-ECD and MDCTA provides different results in the evaluation of plaque. Our results suggest that information derived from US-ECD should be always critically compared with other diagnostic techniques.

  1. Significance of CT examination in a dental hospital

    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)

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

    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 = 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) Dabove = (1.3 ±0.8) .10 -5 Pa -1 (DAAA (0.6 ±0.5) .10 -5 Pa -1) t-test pD<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.)

  3. Application of an asymmetric flow field flow fractionation multi-detector approach for metallic engineered nanoparticle characterization - Prospects and limitations demonstrated on Au nanoparticles

    Highlights: → In this study we present a size- and element selective method, outlined to characterize metallic ENPs, and demonstrated on engineered Au-NP. → A method for quantification of ionic- and particular fraction for nanoparticles in dispersions is presented. → Influence of membrane materials, carrier liquid and flow parameters for A4F was studied. → Comparison of MALLS and DLS for nanoparticle size determination was performed. → Coupling of ICPMS to the A4F, UV/vis and light scattering apparatus is shown. - Abstract: In this work we discuss about the method development, applicability and limitations of an asymmetric flow field flow fractionation (A4F) system in combination with a multi-detector setup consisting of UV/vis, light scattering, and inductively coupled plasma mass spectrometry (ICPMS). The overall aim was to obtain a size dependent-, element specific-, and quantitative method appropriate for the characterization of metallic engineered nanoparticle (ENP) dispersions. Thus, systematic investigations of crucial method parameters were performed by employing well characterized Au nanoparticles (Au-NPs) as a defined model system. For good separation performance, the A4F flow-, membrane-, and carrier conditions were optimized. To obtain reliable size information, the use of laser light scattering based detectors was evaluated, where an online dynamic light scattering (DLS) detector showed good results for the investigated Au-NP up to a size of 80 nm in hydrodynamic diameter. To adapt large sensitivity differences of the various detectors, as well as to guarantee long term stability and minimum contamination of the mass spectrometer a split-flow concept for coupling ICPMS was evaluated. To test for reliable quantification, the ICPMS signal response of ionic Au standards was compared to that of Au-NP. Using proper stabilization with surfactants, no difference for concentrations of 1-50 μg Au L-1 in the size range from 5 to 80 nm for citrate

  4. 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

    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...

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

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

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

    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.

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

    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.

  8. Interferometry of light particles with a CsI(Tl) multi-detector in the collision: 16O(93.6 MeV/A) + 197Au

    Back angle emissions of light particles have been studied by interferometry in the 160 + 197Au reaction. The experiment was performed at GANIL at 93,6 MeV/A. To achieve the correlation functions in the average backward direction we built entirely a compact multi-detector of Csl scintillators which was set up at 115 degrees to the beam direction. This work describes the relevant tests of the detector, data taking and data processing. The p-p, α-α, d-d, α-d, α-t correlations that we studied exhibit a complete damping of two body resonant nuclear effects. The most surprising result concerns the p-p correlation which, by its new shape, could be the signature of a de-excitation process in two steps. The ordering time of the 2 proton cascade would be of the order of 1.5*10-21 s. (author)

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

    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.

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

    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.

  11. CT Scans

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

  12. Analysis of Left Anterior Descending Coronary Artery Myocardial Bridging as Detected by Multi-Detector Row Computed Tomography

    Hong, Seung Jeong; Koh, Kyung Hun [Chosun University Hospital, Gwangju (Korea, Republic of); Kim, Dong Hun [Soonchunhyang University Bucheon Hospital, Bucheon (Korea, Republic of); Ko, Sung Min [Konkuk University Hospital, Seoul (Korea, Republic of)

    2009-05-15

    We wanted to review the various MDCT findings of myocardial bridging (MB) and we analyzed the correlation of the symptoms with the degree of diastolic compression of the coronary segments with MB. We retrospectively reviewed 1,588 consecutive patients who were referred for coronary MDCT angiography between March 4, 2005, and January 31, 2008. Of the 1,588 patients, 85 patients with MB in the left anterior descending coronary artery (LAD) were included in this study. 16-slice and 64- slice CT scanners were used. Multiplanar reformation, maximal intensity projection, 3-dimensional reconstruction images were used for evaluating MB. We recorded the involved segments, the depth and length of the MB and we compared the CTA findings with the symptoms and those findings of ECG and conventional coronary angiography. Of the 85 patients, myocardial ischemia or infarction was detected in 26 patients, atypical chest pain was detected in 2, and no symptoms were detected in 38. The MB was mostly seen in the LAD mid segment in 92%, 85% and 82% of each symptom group. We found no difference in the prevalence of atypical chest pain when comparing the length of the involved segments (p = 0.08) and the depth of the buried segments (p = 0.59). MBs are mostly seen in the LAD mid segments and the combined chest pain does not correlate with the length and depth of the involved segments.

  13. Analysis of Left Anterior Descending Coronary Artery Myocardial Bridging as Detected by Multi-Detector Row Computed Tomography

    We wanted to review the various MDCT findings of myocardial bridging (MB) and we analyzed the correlation of the symptoms with the degree of diastolic compression of the coronary segments with MB. We retrospectively reviewed 1,588 consecutive patients who were referred for coronary MDCT angiography between March 4, 2005, and January 31, 2008. Of the 1,588 patients, 85 patients with MB in the left anterior descending coronary artery (LAD) were included in this study. 16-slice and 64- slice CT scanners were used. Multiplanar reformation, maximal intensity projection, 3-dimensional reconstruction images were used for evaluating MB. We recorded the involved segments, the depth and length of the MB and we compared the CTA findings with the symptoms and those findings of ECG and conventional coronary angiography. Of the 85 patients, myocardial ischemia or infarction was detected in 26 patients, atypical chest pain was detected in 2, and no symptoms were detected in 38. The MB was mostly seen in the LAD mid segment in 92%, 85% and 82% of each symptom group. We found no difference in the prevalence of atypical chest pain when comparing the length of the involved segments (p = 0.08) and the depth of the buried segments (p = 0.59). MBs are mostly seen in the LAD mid segments and the combined chest pain does not correlate with the length and depth of the involved segments

  14. Correlation between model observer and human observer performance in CT imaging when lesion location is uncertain

    Purpose: The purpose of this study was to investigate the correlation between model observer and human observer performance in CT imaging for the task of lesion detection and localization when the lesion location is uncertain.Methods: Two cylindrical rods (3-mm and 5-mm diameters) were placed in a 35 × 26 cm torso-shaped water phantom to simulate lesions with −15 HU contrast at 120 kV. The phantom was scanned 100 times on a 128-slice CT scanner at each of four dose levels (CTDIvol = 5.7, 11.4, 17.1, and 22.8 mGy). Regions of interest (ROIs) around each lesion were extracted to generate images with signal-present, with each ROI containing 128 × 128 pixels. Corresponding ROIs of signal-absent images were generated from images without lesion mimicking rods. The location of the lesion (rod) in each ROI was randomly distributed by moving the ROIs around each lesion. Human observer studies were performed by having three trained observers identify the presence or absence of lesions, indicating the lesion location in each image and scoring confidence for the detection task on a 6-point scale. The same image data were analyzed using a channelized Hotelling model observer (CHO) with Gabor channels. Internal noise was added to the decision variables for the model observer study. Area under the curve (AUC) of ROC and localization ROC (LROC) curves were calculated using a nonparametric approach. The Spearman's rank order correlation between the average performance of the human observers and the model observer performance was calculated for the AUC of both ROC and LROC curves for both the 3- and 5-mm diameter lesions.Results: In both ROC and LROC analyses, AUC values for the model observer agreed well with the average values across the three human observers. The Spearman's rank order correlation values for both ROC and LROC analyses for both the 3- and 5-mm diameter lesions were all 1.0, indicating perfect rank ordering agreement of the figures of merit (AUC) between the

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

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

  16. Comparison of dynamic CT and dynamic MR imaging for detection of hepatocellular carcinoma

    Dynamic study using contrast agents have been used to detection of the hepatocellular carcinoma (HCC). Some reports indicated that the detectability of small nodules in liver with MRI-dynamic study is significantly superior to that with CT-dynamic study. However, these reasons are unknown. Therefore, the contrast, temporal and spatial resolutions were compared for dynamic studies of MRI and CT. Two contrast phantoms were made for MRI and CT. Both phantoms were constructed using same dilute rates of contrast material: Gd-DTPA and Iodine. The signal intensity of some different dilute rate's contrast media was measured for comparison of signal to noise ratio (SNR), contrast to noise ratio (CNR) and contrast. Time-intensity curves simulated with pharmacokinetic compartment model were evaluated for temporal resolution. In addition, the spatial resolution of CT and MR images were compared using the modulation transfer function (MTF). In the results, contrasts of phantoms with MRI and CT-dynamic study were almost same. However, MRI-dynamic study were superior to CT-dynamic study for SNR and contrast. For the distributed rates of contrast media at aortic phase, MRI-dynamic study was higher than helical CT-dynamic study but same as Multi detector-row CT (MDCT). For spatial resolution, CT images were superior to MR images. Therefore, it was recommended that MRI-dynamic study should be examined for fatty patients and MDCT-dynamic study should be examined for thin patients. (author)

  17. CT findings in patients with chronic thromboembolic pulmonary hypertension

    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.)

  18. CT findings in patients with chronic thromboembolic pulmonary hypertension; Spiral-CT bei chronisch thromboembolischer pulmonaler Hypertonie

    Heinrich, M.; Grgic, A.; Heckmann, M.; Kramann, B. [Abt. fuer Radiodiagnostik, Universitaetsklinikum des Saarlandes, Homburg (Germany); Tscholl, D.; Schaefers, H.J. [Abt. fuer Herz-, Thorax- und Gefaesschirurgie, Universitaetsklinikum des Saarlandes, Homburg (Germany); Uder, M. [Inst. fuer Diagnostische Radiologie, Friedrich Alexander-Univ. Erlangen-Nuernberg, Erlangen (Germany)

    2005-07-01

    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.)

  19. Development of an automated extraction method for liver tumors in three dimensional multiphase multislice CT images

    This paper proposes a tumor detection method using four phase three dimensional (3D) CT images of livers, i.e. non-contrast, early, portal, and late phase images. The method extracts liver regions from the four phase images and enhances tumors in the livers using a 3D adaptive convergence index filter. Then it detects local maximum points and extracts tumor candidates by a region growing method. Subsequently several features of the candidates are measured and each candidate is classified into true tumor or normal tissue based on Mahalanobis distances. Above processes except liver region extraction are applied to four phase images, independently and four resultant images are integrated into one. We applied the proposed method to 3D abdominal CT images of ten patients obtained with multi-detector row CT scanner and confirmed that tumor detection rate was 100% without false positives, which was quite promising results. (author)

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

    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.

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

    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.

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

    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)

  3. 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

    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.

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

    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.)

  5. Multi-Detector Row Computed Tomographic Evaluation of a Rare Type of Complete Vascular Ring: Double Aortic Arch with Atretic Left Arch Distal to the Origin of Left Subclavian Artery

    Hung, Ying-Ying; Fu, Yun-Ching; Wei, Hao-Ji; Tsai, I-Chen; Chen, Clayton Chi-Chang

    2013-01-01

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

  6. Investigation of temporal resolution required for CT coronary angiography

    Ohashi, Kazuya; Ichikawa, Katsuhiro; Kawai, Tatsuya; Shibamoto, Yuta

    2012-03-01

    Sub-second multi-detector computed tomography systems (MDCTs) offer great potentials for improving cardiac imaging. However, since the temporal resolution of such CT systems is not sufficient, blurring and artifacts produced by fast cardiac motion are still problematic. The purposes of this study were to investigate the accurate method for measurement of temporal resolution (TR) of the cardiac CT and required TR for obtaining better CT coronary angiography (CTCA). We employed a dual source CT system (Somatom Definition, Siemens), which has various temporal resolution modes (83, 125, and 165 msec) for electro-cardiogram (ECG)-gated scanning. The temporal sensitivity profiles (TSPs) were measured by a new method using temporal impulse generated by metal ball (impulse method). The CTCA images of 200 patients with heart rates (HRs) ranging from 36 to 117 beat per minute (bpm) were visually evaluated using a 4-point scale. The 165-msec TR mode, which is mostly available on recent MDCTs, showed a sufficient image quality only at low HR (80 bpm).

  7. Patient dosimetry study of a paediatric CT examination

    Dosimetry studies are of increasing interest in diagnostic high-dose applications such as computed tomography especially for examinations of children. A routine CT scan protocol for paediatric head and neck imaging was investigated at a new multi-detector CT scanner using LiF:Mg,Cu,P thermoluminescence dosemeters (TLDs) and a 0.125 cm3 thimble ionization chamber. Calibrations of the detectors in terms of absorbed dose to water were carried out at the Dosimetry Laboratory Seibersdorf in standard radiation fields. The dosimetry method was validated in the spiral CT X-ray field by comparing TLD and ionization chamber measurement results in cylindrical PMMA phantoms. Absorbed dose results were within stated uncertainties. An anthropomorphic phantom representing a child of about 5 years was loaded with TLD chips at various organ and tissue positions in the head and neck region as well as at some critical organ locations. Organ dose values were calculated from TLD based average absorbed dose with about 5% total uncertainty, e.g. 22 mGy (eyes), 21 mGy (thyroid), 19 mGy (brain), 3.4 mGy (thymus), and 0.03 mGy (testes). For comparison purposes an effective dose of 1.9 mSv was estimated for the investigated paediatric CT examination based on ICRP-103 age-independent tissue-weighting factors.

  8. CT pelvimetry

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

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

    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.

  10. Clinical utility of ultra high pitch dual source thoracic CT imaging of acute pulmonary embolism in the emergency department: Are we one step closer towards a non-gated triple rule out?

    Hou, Daniel J., E-mail: danieljameshou@gmail.com; Tso, David K., E-mail: david.k.tso@gmail.com; Davison, Chris, E-mail: chrisdavison100@gmail.com; Inacio, Joao, E-mail: joao.r.inacio@gmail.com; Louis, Luck J., E-mail: lucklouis@gmail.com; Nicolaou, Savvakis, E-mail: savvas.nicolaou@vch.ca; Reimann, Anja J., E-mail: anja.reimann@gmx.de

    2013-10-01

    Objectives/Purpose: Aim of this study was to retrospectively compare the image quality and the radiation dose of an ultra high pitch CT scan for the evaluation of pulmonary embolism and visualization of cardiac structures in comparison to our institution's standard pulmonary embolism protocol. Method and materials: The study cohort consisted of 115 consecutive patients, 57 underwent CT pulmonary angiography on a dual source 128 slice scanner (Siemens Somatom Definition FLASH) via an ultra high pitch mode (Pitch 2.8) while 58 were scanned on a dual source 64 slice scanner (Siemens Somatom Definition Dual Source) with standard pitch (Pitch 0.9). Qualitative image assessment was determined by two blinded radiologists with 3 and 15 years’ experience in chest and cardiac CT. Quantitative image assessment was determined by the signal to noise ratio (SNR) and contrast to noise ratio (CNR). Effective radiation dose was calculated via the product of the dose length product. Results: For the ultra high pitch protocol, 14% (8/57) were positive for pulmonary embolus compared to 13.7% (8/58) for the standard pitch group. 98.2% of the ultra high pitch scans were diagnostic for pulmonary embolus vs. 94.8% of the standard protocol. Visualization of cardiac structures was significantly improved with the ultra high pitch protocol (p < 0.0001). Significantly more lung parenchymal motion was observed on the standard protocol (p < 0.0001). The mean pulmonary vessel attenuation, SNR, and CNR were not significantly different. The mean effective dose was lower for the ultra high pitch studies (4.09 mSv ± 0.78 vs. 7.72 mSv ± 2.60, p < 0.0001). Conclusion: Ultra high pitch CT imaging for pulmonary embolus is a technique which has potential to assess motion free evaluation of most cardiac structures and proximal coronary arteries at lower radiation doses.

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

    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.

  12. Assessment of the Right Ventricular Function and Mass Using Cardiac Multi-Detector Computed Tomography in Patients with Chronic Obstructive Pulmonary Disease

    We wanted to assess the relationship between measurements of the right ventricular (RV) function and mass, with using cardiac multi-detector computed tomography (MDCT) and the severity of chronic obstructive pulmonary disease (COPD) as determined by the pulmonary function test (PFT). Measurements of PFT and cardiac MDCT were obtained in 33 COPD patients. Using the Global Initiative for Chronic Obstructive Lung Disease (GOLD) classification, the patients were divided into three groups according to the severity of the disease: stage I (mild, n = 4), stage II (moderate, n = 15) and stage III (severe, n = 14). The RV function and the wall mass were obtained by cardiac MDCT. The results were compared among the groups using the Student-Newman-Keuls method. Person's correlation was used to evaluate the relationship between the right ventricular ejection fraction (RVEF) and the wall mass results with the PFT results. P-values less than 0.05 were considered statistically significant. The RVEF and mass were 47 ±3% and 41 ±2 g in stage I, 46 ±6% and 46 ±5 g in stage II, and 35 ±5% and 55 ±6 g in stage III, respectively. The RVEF was significantly lower in stage III than in stage I and II (p < 0.01). The RV mass was significantly different among the three stages, according to the disease severity of COPD (p < 0.05). The correlation was excellent between the MDCT results and forced expiratory volume in 1 sec (r = 0.797 for RVEF and r -0.769 for RV mass) and forced expiratory volume in 1 sec to the forced vital capacity (r = 0.745 for RVEF and r = -0.718 for RV mass). Our study shows that the mean RV wall mass as measured by cardiac MDCT correlates well with the COPD disease severity as determined by PFT

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

    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

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

    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.

  15. Comparison of 64-slice multi-detector computed tomography coronary angiography between asymptomatic, type 2 diabetes mellitus and impaired glucose tolerance patients

    Cardiovascular disease is the most frequent cause of death and disability for diabetic patients, and patients with diabetes are more likely to have silent ischemia. Multi-detector computed tomography (MDCT) allows non-invasive assessment of coronary artery stenosis and plaque properties. In this study, we investigated whether 64-slice MDCT can non-invasively identify significant coronary artery stenosis in asymptomatic, type 2 diabetes mellitus (T2DM) and impaired glucose tolerance (IGT) patients. The study population consisted of 154 consecutive asymptomatic patients [IGT (n=93), T2DM (n=61)]. All patients underwent contrast-enhanced 64-slice MDCT. The number of diseased coronary segments was classified as showing obstructive (≥50% luminal narrowing) disease or not. Significant coronary stenosis was detected in 43 (27.9%) of 154 enrolled patients. Patients with T2DM showed significantly more coronary stenosis than patients with IGT (41% vs. 19.4%; p<0.01). Twenty-three patients [14.9%; IGT (n=9), T2DM (n=14)] underwent percutaneous coronary intervention (PCI) for severe stenosis. Patients with T2DM showed significantly more calcified plaque than IGT (47.5% vs. 29%; p<0.05), but not significantly more soft plaque (19.7% vs. 15.1%; ns), or significantly different remodeling index (1.05±0.18 vs. 1.04±0.21; ns), respectively. 64-Slice MDCT can non-invasively identify significant coronary artery stenosis in asymptomatic, T2DM and IGT patients. (author)

  16. CT scan

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

  17. Trabecular structure analysis using C-arm CT: comparison with MDCT and flat-panel volume CT

    This paper assesses interscan, interreader, and intrareader variability of C-arm CT and compares it to that of flat-panel volume-CT (fpVCT) and high-definition multi-detector-CT (HD-MDCT). Five cadaver knee specimens were imaged using C-arm-CT, fpVCT, and HD-MDCT. Apparent (app.) trabecular bone volume fraction (BV/TV), app. trabecular number (TbN), app. trabecular spacing (TbSp), and app. trabecular thickness (TbTh) of the proximal tibia were measured by three readers. Interreader, intrareader, and interscan variability for C-arm CT was expressed as coefficient of variation (CV), standard deviation (SD), and intraclass correlation coefficient (ICC). With the exception of app.TbSp (CV: 7.05-9.35%, SD: 0.06-0.09, ICC: 0.89-0.94), the variability of C-arm CT was low (CV: 2.41-6.43%, SD: 0.01-0.048, ICC: 0.65-0.98). Its interreader reliability (CV: 2.66-4.55%, SD: 0.01-0.03, ICC: 0.81-0.95) was comparable to that of HD-MDCT (CV: 2.41-4.08%, SD: 0.014-0.016, ICC: 0.95-0.96), and fpVCT (CV: 3.13-5.63%, SD: 0.009-0.036, ICC: 0.64-0.98) for all parameters except app.TbSp. C-arm CT is a reliable method for assessing trabecular bone architectural parameters with the exception of app.TbSp due to spatial resolution limitation. (orig.)

  18. Trabecular structure analysis using C-arm CT: comparison with MDCT and flat-panel volume CT

    Phan, Catherine M.; Bredella, Miriam A.; Yoo, Albert J.; Hirsch, Joshua A.; Gupta, Rajiv [Massachusetts General Hospital Neuroradiology, Department of Radiology, Boston, MA (United States); Harvard Medical School, Boston, MA (United States); Macklin, Eric A. [Harvard Medical School, Boston, MA (United States); Massachusetts General Hospital, Biostatistics Center, Department of Medicine, Boston, MA (United States); Dadrich, Monica; Flechsig, Paul [German Cancer Research Center, Heidelberg (Germany)

    2011-08-15

    This paper assesses interscan, interreader, and intrareader variability of C-arm CT and compares it to that of flat-panel volume-CT (fpVCT) and high-definition multi-detector-CT (HD-MDCT). Five cadaver knee specimens were imaged using C-arm-CT, fpVCT, and HD-MDCT. Apparent (app.) trabecular bone volume fraction (BV/TV), app. trabecular number (TbN), app. trabecular spacing (TbSp), and app. trabecular thickness (TbTh) of the proximal tibia were measured by three readers. Interreader, intrareader, and interscan variability for C-arm CT was expressed as coefficient of variation (CV), standard deviation (SD), and intraclass correlation coefficient (ICC). With the exception of app.TbSp (CV: 7.05-9.35%, SD: 0.06-0.09, ICC: 0.89-0.94), the variability of C-arm CT was low (CV: 2.41-6.43%, SD: 0.01-0.048, ICC: 0.65-0.98). Its interreader reliability (CV: 2.66-4.55%, SD: 0.01-0.03, ICC: 0.81-0.95) was comparable to that of HD-MDCT (CV: 2.41-4.08%, SD: 0.014-0.016, ICC: 0.95-0.96), and fpVCT (CV: 3.13-5.63%, SD: 0.009-0.036, ICC: 0.64-0.98) for all parameters except app.TbSp. C-arm CT is a reliable method for assessing trabecular bone architectural parameters with the exception of app.TbSp due to spatial resolution limitation. (orig.)

  19. Head CT scan

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

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

    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

  1. Assessment of carotid arteri calcification using 3D-CT angiography

    The aim of this study was to evaluate carotid arteri calcifications using 3D-CT angiography. We performed a retrospective review of 181 patients referred for 64-slice multi-detector row computed tomography. Using curved multiplanar reformation (curved MPR) images of ZIOSOFT M900 QUADRA, we evaluated the distribution of calcifications around the carotid bifurcation. Among the 181 patients, 66 patients (36%) had arterial calcifications. The present study found that almost arterial calcifications localized at the carotid bifurcation. Furthermore, in the group with carotid arterial stenosis, we found arterial calcifications localized not only at the carotid bifurcation, but also at the distal side of internal carotid artery. Curved MPR imaging using 3D-CT angiography is a helpful tool for evaluating calcification of carotid arteries. (author)

  2. Noise power spectrum studies of CT systems with off-centered image object and bowtie filter

    Gomez-Cardona, Daniel; Cruz-Bastida, Juan P.; Li, Ke; Budde, Adam; Hsieh, Jiang; Chen, Guang-Hong

    2016-03-01

    In previous studies of the noise power spectrum (NPS) of multi-detector CT (MDCT) systems, the image object was usually placed at the iso-center of the CT system; therefore, the bowtie filter had negligible impact on the shape of the two-dimensional (2D) NPS of MDCT. This work characterized the NPS of off-centered objects when a bowtie filter is present. It was found that the interplay between the bowtie filter and object position has significant impact on the rotational symmetry of the 2D NPS. Depending on the size of the bowtie filter, the degree of object off-centering, and the location of the region of interest (ROI) used for the NPS measurements, the symmetry of the 2D NPS can be classified as circular, dumbbell, and a peculiar cloverleaf symmetry. An anisotropic NPS corresponds to structured noise texture, which may directly influence the detection performance of certain low contrast detection tasks.

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

    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)

  4. 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

    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

  5. 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

    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

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

    Ferencik, Maros [Department of Radiology, Massachusetts General Hospital and Harvard Medical School, 165 Cambridge Street, Suite 400, Boston, MA 02114 (United States)]. E-mail: maros_ferencik@hms.harvard.edu; Lisauskas, Jennifer B. [Department of Radiology, Massachusetts General Hospital and Harvard Medical School, 165 Cambridge Street, Suite 400, Boston, MA 02114 (United States); Cury, Ricardo C. [Department of Radiology, Massachusetts General Hospital and Harvard Medical School, 165 Cambridge Street, Suite 400, Boston, MA 02114 (United States); Hoffmann, Udo [Department of Radiology, Massachusetts General Hospital and Harvard Medical School, 165 Cambridge Street, Suite 400, Boston, MA 02114 (United States); Abbara, Suhny [Department of Radiology, Massachusetts General Hospital and Harvard Medical School, 165 Cambridge Street, Suite 400, Boston, MA 02114 (United States); Achenbach, Stephan [Department of Medicine II, University of Erlangen, Ulmenweg 18, Erlangen (Germany); Karl, W. Clem [Department of Electrical and Computer Engineering, 8 Saint Mary' s Street, Boston University, Boston, MA (United States); Brady, Thomas J. [Department of Radiology, Massachusetts General Hospital and Harvard Medical School, 165 Cambridge Street, Suite 400, Boston, MA 02114 (United States); Chan, Raymond C. [Department of Radiology, Massachusetts General Hospital and Harvard Medical School, 165 Cambridge Street, Suite 400, Boston, MA 02114 (United States)

    2006-03-15

    Multi-detector computed tomography (MDCT) permits detection of coronary plaque. However, noise and blurring impair accuracy and precision of plaque measurements. The aim of the study was to evaluate MDCT post-processing based on non-linear image deblurring and edge-preserving noise suppression for measurements of plaque size. Contrast-enhanced MDCT coronary angiography was performed in four subjects (mean age 55 {+-} 5 years, mean heart rate 54 {+-} 5 bpm) using a 16-slice scanner (Siemens Sensation 16, collimation 16 x 0.75 mm, gantry rotation 420 ms, tube voltage 120 kV, tube current 550 mAs, 80 mL of contrast). Intravascular ultrasound (IVUS; 40 MHz probe) was performed in one vessel in each patient and served as a reference standard. MDCT vessel cross-sectional images (1 mm thickness) were created perpendicular to centerline and aligned with corresponding IVUS images. MDCT images were processed using a deblurring and edge-preserving noise suppression algorithm. Then, three independent blinded observers segmented lumen and outer vessel boundaries in each modality to obtain vessel cross-sectional area and wall area in the unprocessed MDCT cross-sections, post-processed MDCT cross-sections and corresponding IVUS. The wall area measurement difference for unprocessed and post-processed MDCT images relative to IVUS was 0.4 {+-} 3.8 mm{sup 2} and -0.2 {+-} 2.2 mm{sup 2} (p < 0.05), respectively. Similarly, Bland-Altman analysis of vessel cross-sectional area from unprocessed and post-processed MDCT images relative to IVUS showed a measurement difference of 1.0 {+-} 4.4 and 0.6 {+-} 4.8 mm{sup 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.

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

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

    2007-01-01

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

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

    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. Cardiac CT diagnosis in acute coronary syndrome. Significance of delayed enhancement effect in myocardium

    Authors have found that the effect in the title (DEE) exists in cardiac CT images due to the contrasting agent used for percutaneous coronary intervention (PCI) done shortly after the onset of acute coronary syndrome (ACS). To confirm the finding, they compared images of the cardiac CT and blood flow single photon emission computed tomography (SPECT) obtained several days after ACS. The cardiac CT images of 17 patients (M 15, F 2; average age 63.6 y) with ACS were obtained 20-30 min after the successfully attained emergent enhanced PCI, with the 4-row multi detector low CT (MDCT) machine Aquilion (Toshiba) in synchronization to R-R interval for processing to multiplanar reconstructed (MPR) images. Thereafter (5.5 days in average), myocardial SPECT was conducted with 99mTc-tetrofosmin (740 MBq), of which images were also processed to MPR ones. The CT and SPECT images were compared in coronary arterial territories assigned to 17 segments in the left ventricle and to 20 areas in the Bull's-eye Map. Findings due to DEE in the former CT images were confirmed well correspondent with the lesion found in the latter SPECT, indicating that DEE is a useful tool for evaluation of ACS severity. (R.T.)

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

    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.

  11. Computed Tomography (CT) -- Head

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

  12. Computed Tomography (CT) -- Sinuses

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

  13. Cervical spine CT scan

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

  14. Computed Tomography (CT) -- Sinuses

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

  15. Computed Tomography (CT) -- Head

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

  16. Computed Tomography (CT) -- Sinuses

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

  17. Cardiac CT

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

    2011-07-01

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

  18. CT fluoroscopy

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

  19. [CT fluoroscopy].

    Rogalla, P; Juran, R

    2004-07-01

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

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

    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

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

    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 (CTDIvol)-normalized organ doses and abdominopelvic diameter. We then compared results with values obtained from independent studies. We found that CTDIvol-normalized organ dose correlated strongly with exponentially decreasing abdominopelvic diameter (R2 > 0.8 for most organs). A similar relationship was determined for effective dose when normalized by dose-length product (R2 = 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 CTDIvol prior to CT examination. This information provides an improved method for patient dose estimation. (orig.)

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

    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.)

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

    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.

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

    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.

  5. Computed Tomography (CT) -- Sinuses

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

  6. Pelvic CT scan

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

  7. Sinus CT scan

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

  8. Abdominal CT scan

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

  9. Computed Tomography (CT) -- Head

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

  10. Computed Tomography (CT) -- Sinuses

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

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

    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

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

    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

  13. CT fluoroscopy; CT-Durchleuchtung

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

    2004-07-01

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

  14. Trabecular bone class mapping across resolutions: translating methods from HR-pQCT to clinical CT

    Valentinitsch, Alexander; Fischer, Lukas; Patsch, Janina M.; Bauer, Jan; Kainberger, Franz; Langs, Georg; DiFranco, Matthew

    2015-03-01

    Quantitative assessment of 3D bone microarchitecture in high-resolution peripheral quantitative computed tomography (HR-pQCT) has shown promise in fracture risk assessment and biomechanics, but is limited to the distal radius and tibia. Trabecular microarchitecture classes (TMACs), based on voxel-wise clustering texture and structure tensor features in HRpQCT, is extended in this paper to quantify trabecular bone classes in clinical multi-detector CT (MDCT) images. Our comparison of TMACs in 12 cadaver radii imaged using both HRpQCT and MDCT yields a mean Dice score of up to 0.717+/-0.40 and visually concordant bone quality maps. Further work to develop clinically viable bone quantitative imaging using HR-pQCT validation could have a significant impact on overall bone health assessment.

  15. Percutaneous sacroplasty with the use of C-arm flat-panel detector CT: technical feasibility and clinical outcome

    Kang, Sung Eun; Lee, Joon Woo; Kim, Joo Hyung; Kang, Heung Sik [Seoul National University Bundang Hospital, Department of Radiology, Gyeonggi-do (Korea, Republic of); Park, Kun Woo; Yeom, Jin S. [Seoul National University Bundang Hospital, Department of Orthopaedic Surgery, Gyeonggi-do (Korea, Republic of)

    2011-04-15

    Sacroplasty for sacral insufficiency fractures (SIFs) has been performed mostly under computed tomography (CT) or fluoroscopy guidance. The purposes of this study are to describe technical tips and clinical outcomes of sacroplasty under C-arm flat panel detector CT (C-arm CT) guidance, and to compare the cement distributions shown on C-arm CT with those on multi-detector CT (MDCT). This study consisted of patients who underwent sacroplasty for SIF using C-arm CT from May 2006 to May 2009. Technical success was assessed in terms of cement filling and leakage. Clinical outcome was assessed at short-term (less than 1 month) and long-term (more than 1 month) follow-up using a four-grade patient satisfaction scale: poor, fair, good, and excellent. After sacroplasty, all patients underwent MDCT and three radiologists compared MDCT images with C-arm CT images in consensus, focusing on the cement distribution and cement leakage. Sacroplasties were performed on both sacral alae in all 8 patients (male:female = 2:6, mean age = 76.9, range = 63-82). The technical success rate was 100%. At short-term follow up, 6 patients (87.5%) reported significant improvement. Five patients (62.5%) were available for long-term follow-up and all 5 patients reported a reduced pain and an improved ability to ambulate. Using MDCT as the standard of reference, the cement distribution was visualized equally well by C-arm CT. Sacroplasty under C-arm CT showed excellent technical success and good clinical outcome. There was an excellent correlation between C-arm CT and MDCT in evaluating cement distribution and cement leakage. (orig.)

  16. Percutaneous sacroplasty with the use of C-arm flat-panel detector CT: technical feasibility and clinical outcome

    Sacroplasty for sacral insufficiency fractures (SIFs) has been performed mostly under computed tomography (CT) or fluoroscopy guidance. The purposes of this study are to describe technical tips and clinical outcomes of sacroplasty under C-arm flat panel detector CT (C-arm CT) guidance, and to compare the cement distributions shown on C-arm CT with those on multi-detector CT (MDCT). This study consisted of patients who underwent sacroplasty for SIF using C-arm CT from May 2006 to May 2009. Technical success was assessed in terms of cement filling and leakage. Clinical outcome was assessed at short-term (less than 1 month) and long-term (more than 1 month) follow-up using a four-grade patient satisfaction scale: poor, fair, good, and excellent. After sacroplasty, all patients underwent MDCT and three radiologists compared MDCT images with C-arm CT images in consensus, focusing on the cement distribution and cement leakage. Sacroplasties were performed on both sacral alae in all 8 patients (male:female = 2:6, mean age = 76.9, range = 63-82). The technical success rate was 100%. At short-term follow up, 6 patients (87.5%) reported significant improvement. Five patients (62.5%) were available for long-term follow-up and all 5 patients reported a reduced pain and an improved ability to ambulate. Using MDCT as the standard of reference, the cement distribution was visualized equally well by C-arm CT. Sacroplasty under C-arm CT showed excellent technical success and good clinical outcome. There was an excellent correlation between C-arm CT and MDCT in evaluating cement distribution and cement leakage. (orig.)

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

    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%.

  18. Evaluation for urinary tract lesions by CT urography. Comparison with excretory urography

    The purpose of study is to evaluate urinary tract lesions by CT urography (CTU). The axial images from the acquired raw data of CTU are compared with conventional CT images in 31 renal lesions. CTU is compared with excretory urography (EU) in 25 urinary tract lesions. On 8 min after oral administration of 200 ml of water and intravenous injection of 100 ml of iopamidol (300 mgI/ml), the whole abdomen is scanned for CTU in collimation 1.0 mm x4, pitch 6, effective slice thickness 1.25 mm using multi-detector CT (Siemens, Volume Zoom). Volume rendering images of the upper urinary tract are reconstructed from the acquired raw data by 3D image console (Azemoto, Virtual Place, Tokyo). The axial images from acquired raw data of CTU were equal to the conventional CT images of the kidney in detection of the renal lesions except for renal stones. CTU was equal or superior to EU in detection of urinary tract lesions except for ureteral stones and calyceal deformity. CTU is superior to EU in evaluation of urinary tract lesions except for stones. However, the axial images from the acquired raw data of CTU are necessary for suitable evaluation. (author)

  19. 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

    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。

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

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

  1. Triple rule-out CT in the emergency department: protocols and spectrum of imaging findings

    Frauenfelder, Thomas; Appenzeller, Philippe; Karlo, Christoph; Scheffel, Hans; Desbiolles, Lotus; Stolzmann, Paul; Marincek, Borut; Alkadhi, Hatem; Schertler, Thomas [University Hospital Zurich, Department of Medical Radiology, Institute of Diagnostic Radiology, Zurich (Switzerland)

    2009-04-15

    Triage decisions in patients suffering from acute chest pain remain a challenge. The patient's history, initial cardiac enzyme levels, or initial electrocardiograms (ECG) often do not allow selecting the patients in whom further tests are needed. Numerous vascular and non-vascular chest problems, such as pulmonary embolism (PE), aortic dissection, or acute coronary syndrome, as well as pulmonary, pleural, or osseous lesions, must be taken into account. Nowadays, contrast-enhanced multi-detector-row computed tomography (CT) has replaced previous invasive diagnostic procedures and currently represents the imaging modality of choice when the clinical suspicion of PE or acute aortic syndrome is raised. At the same time, CT is capable of detecting a multitude of non-vascular causes of acute chest pain, such as pneumonia, pericarditis, or fractures. Recent technical advances in CT technology have also shown great advantages for non-invasive imaging of the coronary arteries. In patients with acute chest pain, the optimization of triage decisions and cost-effectiveness using cardiac CT in the emergency department have been repetitively demonstrated. Triple rule-out CT denominates an ECG-gated protocol that allows for the depiction of the pulmonary arteries, thoracic aorta, and coronary arteries within a single examination. This can be accomplished through the use of a dedicated contrast media administration regimen resulting in a simultaneous attenuation of the three vessel territories. This review is intended to demonstrate CT parameters and contrast media administration protocols for performing a triple rule-out CT and discusses radiation dose issues pertinent to the protocol. Typical life-threatening and non-life-threatening diseases causing acute chest pain are illustrated. (orig.)

  2. Computed Tomography (CT) -- Head

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

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

    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.)

  4. Evaluation of Ultra-Low Dose CT in the Diagnosis of Pediatric-Like Fractures Using an Experimental Animal Study

    Mortiz, Joerg D.; Hoffmann, Beata; Sehr, Dirk; Keil, Katrin; Eggerking, Juiliane; Groth, Godro; Caliebe, Amke; Heller, Martin; Bolte, Hendrik [University Hospital Schleswig-Holstein, Campus Kiel, Kiel (Germany); Dischinger, Jens [University Kiel, Kiel (Germany)

    2012-03-15

    The aim of this prospective study was to evaluate the performance of ultra-low dose CT for the diagnosis of pediatric-like fractures and ascertain the lowest dose level sufficient for diagnostics. Fifty-one bones of young pig cadavers were artificially fractured and subsequently examined by using a 64 multi-detector CT with 36 various dose levels down to a dose comparable with that of X-rays. Two pediatric radiologists analysed the CT scans according to the presence or absence of a fracture, determination of the fracture type and the displacement as well as the diagnostic certainty. For each dose protocol, a success rate for the correct determination of the above-mentioned CT analyses was calculated. A success rate of at least 95% was considered sufficient for diagnostics. All but the lowest dose levels were sufficient to identify the fracture. Only the two lowest dose levels were insufficient to detect the fracture type. All dose levels were adequate for the identification of the displacement. The lowest dose level sufficient for diagnostics was 120 kVp, 11 mAs, and pitch 1.5, with a CTDIvol of 10% of a standard dose and an effective dose three times as large as that of X-rays. Ultra-low dose CT provides the feasibility of a significant dose reduction, still allowing sufficient diagnostics of pediatric-like fractures.

  5. Spinal CT scan, 1

    Methods of CT of the cervical and thoracic spines were explained, and normal CT pictures of them were described. Spinal CT was evaluated in comparison with other methods in various spinal diseases. Plain CT revealed stenosis due to spondylosis or ossification of posterior longitudinal ligament and hernia of intervertebral disc. CT took an important role in the diagnosis of spinal cord tumors with calcification and destruction of the bone. CT scan in combination with other methods was also useful for the diagnosis of spinal injuries, congenital anomalies and infections. (Ueda, J.)

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

    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 doses were 0

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

    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.

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

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

    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.)

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

    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.)

  11. Computed Tomography (CT) -- Sinuses

    Full Text Available ... to a CD or DVD. CT images of internal organs, bones, soft tissue and blood vessels typically ... clicking and whirring sounds as the CT scanner's internal parts, not usually visible to you, revolve around ...

  12. Computed Tomography (CT) -- Head

    Full Text Available ... to a CD or DVD. CT images of internal organs, bones, soft tissue and blood vessels typically ... clicking and whirring sounds as the CT scanner's internal parts, not usually visible to you, revolve around ...

  13. Computed Tomography (CT) -- Sinuses

    Full Text Available ... or DVD. CT images of internal organs, bones, soft tissue and blood vessels typically provide greater detail than traditional x-rays, particularly of soft tissues and blood vessels. A CT scan of the ...

  14. Computed Tomography (CT) -- Head

    Full Text Available ... or DVD. CT images of internal organs, bones, soft tissue and blood vessels typically provide greater detail than traditional x-rays, particularly of soft tissues and blood vessels. CT scanning provides more detailed ...

  15. Computed Tomography (CT) -- Head

    Full Text Available ... resulting in more detail and additional view capabilities. Modern CT scanners are so fast that they can ... to ensure that you are properly positioned. With modern CT scanners, you will hear only slight buzzing, ...

  16. Computed Tomography (CT) -- Sinuses

    Full Text Available ... resulting in more detail and additional view capabilities. Modern CT scanners are so fast that they can ... to ensure that you are properly positioned. With modern CT scanners, you will hear only slight buzzing, ...

  17. Computed Tomography (CT) -- Head

    Full Text Available ... view of the body's interior. Refinements in detector technology allow nearly all CT scanners to obtain multiple ... scanning is painless, noninvasive and accurate. A major advantage of CT is its ability to image bone, ...

  18. Computed Tomography (CT) -- Sinuses

    Full Text Available ... view of the body's interior. Refinements in detector technology allow nearly all CT scanners to obtain multiple ... scanning is painless, noninvasive and accurate. A major advantage of CT is its ability to image bone, ...

  19. Computed Tomography (CT) -- Sinuses

    Full Text Available ... actual CT scanning is performed. Depending on the type of CT scan, the machine may make several passes. You may be asked to hold your breath during the scanning. Any motion, whether breathing ...

  20. Computed Tomography (CT) -- Head

    Full Text Available ... actual CT scanning is performed. Depending on the type of CT scan, the machine may make several passes. You may be asked to hold your breath during the scanning. Any motion, whether breathing ...

  1. Computed Tomography (CT) -- Sinuses

    Full Text Available ... be viewed on a computer monitor, printed on film or transferred to a CD or DVD. CT ... distinguished from one another on an x-ray film or CT electronic image. In a conventional x- ...

  2. Computed Tomography (CT) -- Head

    Full Text Available ... be viewed on a computer monitor, printed on film or transferred to a CD or DVD. CT ... distinguished from one another on an x-ray film or CT electronic image. In a conventional x- ...

  3. Computed Tomography (CT) -- Sinuses

    Full Text Available ... air-filled spaces within the bones of the face surrounding the nasal cavity. CT scanning is painless, ... and blood vessels. A CT scan of the face produces images that also show a patient's paranasal ...

  4. Computed Tomography (CT) -- Head

    Full Text Available ... dose technique. top of page What are the limitations of CT Scanning of the Head? A person ... CT scanner or may be over the weight limit—usually 450 pounds—for the moving table. Compared ...

  5. Computed Tomography (CT) -- Sinuses

    Full Text Available ... body. The cross-sectional images generated during a CT scan can be reformatted in multiple planes, and can ... particularly of soft tissues and blood vessels. A CT scan of the face produces images that also show ...

  6. Computed Tomography (CT) -- Head

    Full Text Available ... body. The cross-sectional images generated during a CT scan can be reformatted in multiple planes, and can ... scanning is performed. Depending on the type of CT scan, the machine may make several passes. You may ...

  7. Computed Tomography (CT) -- Head

    Full Text Available ... DVD. CT images of internal organs, bones, soft tissue and blood vessels typically provide greater detail than traditional x-rays, particularly of soft tissues and blood vessels. CT scanning provides more detailed ...

  8. Computed Tomography (CT) -- Sinuses

    Full Text Available ... DVD. CT images of internal organs, bones, soft tissue and blood vessels typically provide greater detail than traditional x-rays, particularly of soft tissues and blood vessels. A CT scan of the ...

  9. Computed Tomography (CT) -- Head

    Full Text Available ... CT Angiography page . top of page How should I prepare? You should wear comfortable, loose-fitting clothing ... within 10 minutes. top of page What will I experience during and after the procedure? CT exams ...

  10. Computed Tomography (CT) -- Sinuses

    Full Text Available ... sinus cavities – hollow, air-filled spaces within the bones of the face surrounding the nasal cavity. CT ... CD or DVD. CT images of internal organs, bones, soft tissue and blood vessels typically provide greater ...

  11. Computed Tomography (CT) -- Sinuses

    Full Text Available ... top of page What are the benefits vs. risks? Benefits A CT scan is one of the ... CT scans should have no immediate side effects. Risks There is always a slight chance of cancer ...

  12. Computed Tomography (CT) -- Head

    Full Text Available ... top of page What are the benefits vs. risks? Benefits CT scanning is painless, noninvasive and accurate. ... CT scans should have no immediate side effects. Risks There is always a slight chance of cancer ...

  13. Computed Tomography (CT) -- Sinuses

    Full Text Available ... the scanning. Any motion, whether breathing or body movements, can lead to artifacts on the images. This ... clinical problems. CT is less sensitive to patient movement than MRI. CT can be performed if you ...

  14. Computed Tomography (CT) -- Head

    Full Text Available ... the scanning. Any motion, whether breathing or body movements, can lead to artifacts on the images. This ... clinical problems. CT is less sensitive to patient movement than MRI. CT can be performed if you ...

  15. Computed Tomography (CT) -- Sinuses

    Full Text Available ... vessels. CT examinations are fast and simple; in emergency cases, they can reveal internal injuries and bleeding ... See the Safety page for more information about pregnancy and x-rays. CT scanning is, in general, ...

  16. Computed Tomography (CT) -- Head

    Full Text Available ... microphone. top of page How does the procedure work? In many ways CT scanning works very much ... many types of tissue as well as the lungs, bones, and blood vessels. CT examinations are fast ...

  17. Computed Tomography (CT) -- Sinuses

    Full Text Available ... microphone. top of page How does the procedure work? In many ways CT scanning works very much ... many types of tissue as well as the lungs, bones, and blood vessels. CT examinations are fast ...

  18. Computed Tomography (CT) -- Head

    Full Text Available ... Contrast Media and its references. The risk of serious allergic reaction to contrast materials that contain iodine ... of soft tissue (particularly the brain, including the disease processes) are less visible on CT scans . CT ...

  19. Gallstone ileus: CT findings

    Delabrousse, E.; Bartholomot, B.; Sohm, O.; Kastler, B. [Dept. of Radiology A, CHU Jean Minjoz, University of Besancon (France); Wallerand, H. [Dept. of Surgery, CHU Jean Minjoz, University of Besancon (France)

    2000-06-01

    Gallstone ileus is a rare complication of recurrent gallstone cholecystitis. The classic radiographic triad of small bowel obstruction, pneumobilia and ectopic gallstone on abdominal plain radiograph is described with CT imaging. Because of the better resolution of CT compared with abdominal radiography and its recent accession to emergency use, radiologists should be aware of CT findings of gallstone ileus. We report a case in which gallstone ileus was initially diagnosed by CT. (orig.)

  20. CT Colonography (Virtual Colonoscopy)

    ... how do I get them? What are the benefits vs. risks? What are the limitations of CT Colonography? What is CT Colonography? Computed tomography, more commonly known as a CT or CAT scan, is a diagnostic medical test that, like traditional ...

  1. Computed Tomography (CT) -- Head

    Full Text Available ... CT examinations are fast and simple; in emergency cases, they can reveal internal injuries and bleeding quickly enough to help save lives. CT has been shown to be a cost-effective imaging tool for a wide range of clinical problems. CT is less sensitive to patient movement ...

  2. Computed Tomography (CT) -- Sinuses

    Full Text Available ... CT examinations are fast and simple; in emergency cases, they can reveal internal injuries and bleeding quickly enough to help save lives. CT has been shown to be a cost-effective imaging tool for a wide range of clinical problems. CT is less sensitive to patient movement ...

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

    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)

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

    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.

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

    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)

  6. Automated coronary CT angiography plaque-lumen segmentation

    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.

  7. Pediatric metrizamide CT cisternography and CT ventriculography

    We have studied the diagnostic value of computed tomography with metrizamide CSF enhancement in 37 infants. According to the method of injection, we called CT cisternography, CT ventriculography and CT cystography. These methods were useful for the morphologic and dynamic evaluation of the CSF pathways. We used them especially for the evaluation of hydrocephalus, skull base tumor, infantile subdural hematoma and its allied diseases, or congenital cystic lesion such as Dandy-Walker syndrome. The side effects in children are much less than those in adults. (author)

  8. Multislice CT angiography

    The introduction of multislice CT into clinical radiology constitutes a quantum leap that significantly widens the scope of vascular CT imaging. The advances over conventional spiral CT have been quantitative, mainly in terms of increased image acquisition speed which provides unprecedented volume coverage and spatial resolution. Moreover, significant technical innovations, such as cardiac scanning capabilities, have brought about a qualitative shift towards applications that were thought to be beyond the scope of CT imaging. This way multislice CT offers a wealth of new opportunities for quickly and accurately diagnosing suspected vascular disease in all organ systems; however, as we move towards faster and faster image acquisition techniques, we are also facing new challenges that require development of novel strategies in order to take full advantage of the increased capabilities of multislice CT in its current form and future generations of CT scanners. (orig.)

  9. Patient-specific dose estimation for pediatric chest CT

    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 dose for

  10. Patient-specific dose estimation for pediatric chest CT

    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

  11. Spinal CT scan, 2

    Plain CT described fairly accurately the anatomy and lesions of the lumbar and sacral spines on their transverse sections. Since hernia of the intervertebral disc could be directly diagnosed by CT, indications of myelography could be restricted. Spinal-canal stenosis of the lumbar spine occurs because of various factors, and CT not only demonstrated the accurate size and morphology of bony canals, but also elucidated thickening of the joints and yellow ligament. CT was also useful for the diagnosis of tumors in the lumbar and sacral spines, visualizing the images of bone changes and soft tissues on the trasverse sections. But the diagnosis of intradural tumors required myelography and metrizamide CT. CT has become important for the diagnosis of spinal and spinal-cord diseases and for selection of the route of surgical arrival. (Chiba, N.)

  12. Coronary CT Angiography: Current Applications in Clinical Practice Promise for the Future

    S. Wann

    2007-05-01

    Full Text Available The use of computed tomography for cardiac diagno-sis has a long history. CT was first used experimentally to measure myocardial perfusion and to detect infarcation nearly 25 years ago, but poor temporal resolution and high radiation dosage pre-cluded its use in clinical medicine. Later electron beam computed tomography provided sufficiently high temporal resolution to precisely measure cal-cium depositions in the coronary arteries as a marker of coronary atherosclerosis. Large epidemiologic stud-ies have now shown that the coronary artery calcium score gives incremental predictive power to conven-tional risk factor analysis such as the Framinghan score. While its temporal resolution is unchallenged, electron beam CT lacks the spatial resolution to per-form clinically useful coronary angiography. The re-cent development of multi-detector computed tomo-graphy (MDCT has enabled non-invasive coronary angiography, capturing the excitement and enthusi-asm of clinicians around the world. This lecture will briefly review the technology underlying MDCT, dis-cussing limitations related to radiation dosimetry, calcium and gating, as well as other fundamental dif-ferences from conventional angiography. Current clinical indications and appropriate application of MDCT will be discussed, with an emphasis on evi-dence based practice. MDCT is a rapidly evolving field. Areas of research and technical development will be described.

  13. The application and advantages of multi-slice CT in the diagnosis of myocardial bridging

    Objective: To investigate the ability of electrocardiogram-gated multislice CT (MSCT) in the diagnosis of myocardial bridging. Methods: Fifty-one patients (82 coronary arteries) with suspected coronary artery disease underwent multi-detector row CT, conventional coronary angiography and intravascular ultrasonography as well. The sensitivity, specificity and accuracy of MSCT for the detection of myocardial bridging were determined. The interobserver agreement was calculated by using Cohen's Kappa test. Results: A total of 26 tunneled arteries exclusively located near the middle segment of left anterior descending coronary artery were found by coronary angiography and intravascular ultrasonography. Compared to the invasive methods, MSCT correctly detected 23 of 26 myocardial bridges with a sensitivity of 88% (23/26), specificity of 96% (52/54) and accuracy of 94% (75/80). The Kappa value for overall interobserver variation was 0. 62. Two myocardial bridges diagnosed by MSCT were missed with the invasive method. With the results of invasive and non-invasive methods combined as the standard of reference, the overall sensitivity, specificity, and accuracy of MSCT in detecting myocardial bridging were 89% (25/28) , 91% (21/23), and 90% (46/51), respectively. Conclusion: As a non-invasive imaging modality, MSCT is feasible and reliable in the detection of myocardial bridging. (authors)

  14. Computer-aided detection of small bowel strictures in CT enterography

    Sainani, Nisha I.; Näppi, Janne J.; Sahani, Dushyant V.; Yoshida, Hiroyuki

    2011-03-01

    The workflow of CT enterography in an emergency setting could be improved significantly by computer-aided detection (CAD) of small bowel strictures to enable even non-expert radiologists to detect sites of obstruction rapidly. We developed a CAD scheme to detect strictures automatically from abdominal multi-detector CT enterography image data by use of multi-scale template matching and a blob detector method. A pilot study was performed on 15 patients with 22 surgically confirmed strictures to study the effect of the CAD scheme on observer performance. The 77% sensitivity of an inexperienced radiologist assisted by CAD was comparable with the 81% sensitivity of an unaided expert radiologist (p=0.07). The use of CAD reduced the reading time to identify strictures significantly (p<0.0001). Most of the false-positive CAD detections were caused by collapsed bowel loops, approximated bowel wall, muscles, or vessels, and they were easy to dismiss. The results indicate that CAD could provide radiologists with a rapid and accurate interpretation of strictures to improve workflow in an emergency setting.

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

    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 ...

  16. 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

    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

  17. Assessment of two different software solutions for the evaluation of CT colonography

    Purpose: To compare a commercial CT colonography software ('Colonography', Siemens, Forchheim) with a non-commercial post-processing system ('Colotux', Department of Informatics). Material and methods: Identical data sets of 10 patients, who underwent an ultra-low-dose multi-detector CT colonography (ULD-MDCTC) (4 x 1 mm collimation, 8 mm pitch, 120 kVp, 10 mAs) were analyzed retrospectively. Assessment was performed using both software solutions by two resident radiologists, who did not have any experience with any colonography software tool before and who did not know the clinical symptoms of the patients or the results of the conventional colonoscopy. Both systems were analyzed using several subjective quality criteria including workflow, handling, image quality, endoluminal navigation and analysis of lesions with grading on a 5-point-scale. Results concerning polyps were compared between the two systems as well as with conventional colonoscopy. Results: Both colonography systems detected the same number of polyps. Although both showed some advantages for single criteria, no relevant difference was noted in general for subjective assessment. The time for calculation of three dimensional interactive volumes was three times longer for 'Colotux' compared to 'Colonography'. Linux-based 'Colotux' showed a trend towards better subjective image quality and easier measurement of polyp size. An intuitive desktop and 'Syngo'-workflow integration were advantages of 'Colonography'. Conclusion: The analysis of CT colonographies (4-detector-row-CT-scanner, ultra low dose technique, supine position) can adequately be achieved by both software solutions. There was no significant subjective or objective difference of quality between a 'stand-alone' individual system and a commerical workflow-integrated solution. A relevant factor for decision between the two systems may be the difference in time needed for the 3D volume calculation, especially in institutes with a high frequency

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

    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 (CTDIvol) 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

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

    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.

  20. Non-small cell lung cancer: evaluation of the relationship between fibrosis and washout feature at dynamic contrast enhanced CT

    Objective: To correlate dynamic parameters at contrast enhanced CT and interstitial fibrosis grade of' non-small cell lung cancer (NSCLC). Methods: Twenty-nine patients with NSCLC were evaluated by multi-slice CT. Images were obtained before and at 20, 30, 45, 60, 75, 90, 120, 180, 300, 540, 720, 900 and 1200 s after the injection of contrast media, which was administered at a rate of 4 ml/s for a total of 420 mg I/kg body weight. Washout parameters were calculated. Lung cancer specimens were stained with hematoxylin-eosin stain and collagen and elastic double stain. Spearman test was made to analyze correlation between dynamic parameters and interstitial fibrosis grade of tumor. Results: Twenty- nine NSCLC demonstrated washout at 20 min 12.1 (0.32-58.0) HU, washout ratio at 20 minutes 15.3% (0.3%-39.2%), slope of washout at 20 minutes 0.0152%/s (0.0007%/s-0.0561%/s). Interstitial fibrosis of 29 lesions was graded as grade Ⅰ (10), grade Ⅱ (14) and grade Ⅲ (5). There were significant correlation between washout at 20 min (r=-0.402, P<0.05), washout ratio at 20 min (r= -0.372, P<0.05), slope of washout ratio (r=-0.459, P<0.05) and interstitial fibrosis grade in tumors. Conclusion: NSCLC washout features at dynamic multi-detector CT correlates with interstitial fibrosis in the tumor. (authors)

  1. Spiral CT of pancreas. Clinical comparison with conventional CT and dynamic CT; Spiral-CT des Pankreas. Klinischer Vergleich mit der konventionellen CT und der dynamischen CT

    Hidajat, N. [Strahlenklinik und Poliklinik, Universitaetsklinikum Rudolf Virchow, Freie Univ. Berlin (Germany); Schedel, H. [Strahlenklinik und Poliklinik, Universitaetsklinikum Rudolf Virchow, Freie Univ. Berlin (Germany); Vogl, T. [Strahlenklinik und Poliklinik, Universitaetsklinikum Rudolf Virchow, Freie Univ. Berlin (Germany); Schroeder, R.J. [Strahlenklinik und Poliklinik, Universitaetsklinikum Rudolf Virchow, Freie Univ. Berlin (Germany); Keck, H. [Chirurgische Klinik und Poliklinik, Universitaetsklinikum Rudolf Virchow, Freie Univ. Berlin (Germany); Feix, R. [Strahlenklinik und Poliklinik, Universitaetsklinikum Rudolf Virchow, Freie Univ. Berlin (Germany)

    1995-07-01

    Spiral CT is compared with the dynamic CT and the conventional CT with regard to the enhancement of the pancreas and peripancreatic vessels and the visualisation of anatomic details. Compared with dynamic CT, spiral CT of the pancreatic region in the arterial phase (flow 4 ml/s, delay 15-18 s) leads to a stronger contrast of the peripancreatic vessels and the pancreas (108 vs. 86 HU). In the following spiral CT of the upper abdomen (flow 1 ml/s, delay 70 s), a high enhancement of both arteries and veins could be achieved. Intrapancreatic structures and peripancreatic vessels were better seen in the spiral CT than in the conventional CT. The combination of spiral CT of the pancreatic region in the arterial perfusion phase and spiral CT of the upper abdomen in the arterial-venous phase enables an optimal enhancement of the pancreas and the abdominal vessels and a reliable visualisation of anatomic details. (orig./MG) [Deutsch] Es werden die Spiral-CT, die dynamische CT (Dynamic Sequence) und die konventionelle CT im Hinblick auf die Kontrastierung der Pankreasregion und die Visualisierung von anatomischen Details miteinander verglichen. Die Spiral-CT der Pankreasregion fuehrte im Vergleich zur dynamischen CT (Fluss 4 ml/s, Verzoegerung 15-18 s) zu einer hoeheren Dichtesteigerung der peripankreatischen Arterien und des Pankreas (108 vs. 86 HE). Bei der anschliessend durchgefuehrten Spiral-CT des Oberbauches (Fluss 1 ml/s, Verzoegerung 70 s) wurde ein hoher Kontrast sowohl der Arterien als auch der Venen erreicht. Mit dieser gelang eine bessere Erkennbarkeit von intrapankreatischen Strukturen und peripankreatischen Gefaessen als mit der konventionellen CT. Die Kombination der Spiral-CT des Pankreas in der arteriellen Perfusionsphase und der Spiral-CT des Oberbauches in der arteriell-venoesen Phase ermoeglicht eine optimale Kontrastierung des Pankreas und der Oberbauchgefaesse sowie eine zuverlaessige Erfassung von anatomischen Details. (orig./MG)

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

    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 ...

  3. CT features of adenomyosis

    Woodfield, Courtney A. [Department of Diagnostic Imaging, Brown Medical School/Rhode Island Hospital, 593 Eddy Street, Providence, RI 02903 (United States)], E-mail: cwoodfield@lifespan.org; Siegelman, Evan S. [Department of Radiology, University of Pennsylvania School of Medicine, 3400 Spruce Street, Philadelphia, PA 19104 (United States)], E-mail: Evan.Siegelman@uphs.upenn.edu; Coleman, Beverly G. [Department of Radiology, University of Pennsylvania School of Medicine, 3400 Spruce Street, Philadelphia, PA 19104 (United States)], E-mail: Beverly.Coleman@uphs.upenn.edu; Torigian, Drew A. [Department of Radiology, University of Pennsylvania School of Medicine, 3400 Spruce Street, Philadelphia, PA 19104 (United States)], E-mail: Drew.Torigian@uphs.upenn.edu

    2009-12-15

    Objectives: To determine the computed tomography (CT) features of adenomyosis in patients with known adenomyosis as established with magnetic resonance (MR) imaging. Methods: A computerized search identified 16 women with pelvic MR diagnosis of adenomyosis who also had enhanced pelvic CT. Original CT reports were reviewed for potential prospective diagnosis of adenomyosis. CT images were reviewed for enhancement phase, inner and outer myometrium attenuation, uterine enlargement (width>6 cm), inner myometrial thickening ({>=}12 mm), and myometrial cysts. Results: Adenomyosis was detectable on CT in 8 of 16 patients. For these 8 patients, inner and outer myometrium distinction was excellent in 7 (88%) and limited in 1 (12%), and mean inner myometrial thickness was 25 mm (range 14-47 mm). CT enhancement phase was parenchymal in 7 (88%), uterus was enlarged in 8 (100%), and 7 (88%) had myometrial cysts. Adenomyosis was focal in 5 (63%), diffuse in 2 (25%), and both in 1 (12%). None of the original CT reports included adenomyosis as a diagnosis. Conclusions: CT can suggest a diagnosis of adenomyosis based on uterine enlargement, thickened inner myometrium, and/or myometrial cysts.

  4. CT features of adenomyosis

    Objectives: To determine the computed tomography (CT) features of adenomyosis in patients with known adenomyosis as established with magnetic resonance (MR) imaging. Methods: A computerized search identified 16 women with pelvic MR diagnosis of adenomyosis who also had enhanced pelvic CT. Original CT reports were reviewed for potential prospective diagnosis of adenomyosis. CT images were reviewed for enhancement phase, inner and outer myometrium attenuation, uterine enlargement (width>6 cm), inner myometrial thickening (≥12 mm), and myometrial cysts. Results: Adenomyosis was detectable on CT in 8 of 16 patients. For these 8 patients, inner and outer myometrium distinction was excellent in 7 (88%) and limited in 1 (12%), and mean inner myometrial thickness was 25 mm (range 14-47 mm). CT enhancement phase was parenchymal in 7 (88%), uterus was enlarged in 8 (100%), and 7 (88%) had myometrial cysts. Adenomyosis was focal in 5 (63%), diffuse in 2 (25%), and both in 1 (12%). None of the original CT reports included adenomyosis as a diagnosis. Conclusions: CT can suggest a diagnosis of adenomyosis based on uterine enlargement, thickened inner myometrium, and/or myometrial cysts.

  5. Computed Tomography (CT) -- Head

    Full Text Available ... the CT Angiography page . top of page How should I prepare? You should wear comfortable, loose-fitting clothing to your exam. ... and hairpins, may affect the CT images and should be left at home or removed prior to ...

  6. Computed Tomography (CT) -- Head

    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 What is CT Scanning of the Head? What are some ...

  7. Computed Tomography (CT) -- Sinuses

    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 What is CT (Computed Tomography) of the Sinuses? What are ...

  8. Knee CT scan

    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 ...

  9. Knee CT scan

    A computed tomography (CT) scan of the knee is a test that uses x-rays to take detailed images of the knee. ... A CT scan can quickly create more detailed pictures of the knee than standard x-rays. The test may be ...

  10. Computed Tomography (CT) -- Head

    Full Text Available ... Español More Info Images/Videos News Physician Resources Professions Site Index A-Z Computed Tomography (CT) - Head ... CT exam to be stressful. The technologist or nurse, under the direction of a physician, may offer ...

  11. CT of pleural abnormalities

    Briefly discussed were CT diagnosis of pleural thickening, CT technique for examining the pleura or pleuro-pulmonary disease, diagnosis of pleural collections, diagnosis of pleural fluid abnormalities in patients with pneumonia, pleural neoplasms, malignant (diffuse) mesothelioma, metastases, local fibrous tumor of the pleura (benign mesothelioma) (21 refs.)

  12. Computed Tomography (CT) -- Head

    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 ...

  13. Computed Tomography (CT) -- Sinuses

    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 ...

  14. Computed Tomography (CT) -- Head

    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 ...

  15. Computed Tomography (CT) -- Sinuses

    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 ...

  16. Computed Tomography (CT) -- Sinuses

    Full Text Available ... materials that contain iodine is extremely rare, and radiology departments are well-equipped to deal with them. Because children are more sensitive to radiation, they should have a CT exam only if it is essential for making a diagnosis and should not have repeated CT exams unless ...

  17. Computed Tomography (CT) -- Head

    Full Text Available ... materials that contain iodine is extremely rare, and radiology departments are well-equipped to deal with them. Because children are more sensitive to radiation, they should have a CT exam only if it is essential for making a diagnosis and should not have repeated CT exams unless ...

  18. 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

    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)

  19. CT of tracheal agenesis

    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.)

  20. CT of tracheal agenesis

    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.)

  1. Measurement of radiation dose in cerebral CT perfusion study

    The purpose of this study was to evaluate radiation dose in cerebral perfusion studies with a multi-detector row CT (MDCT) scanner on various voltage and current settings by using a human head phantom. Following the CT perfusion study protocol, continuous cine scans (1 sec/rotation x 60 sec) consisting of four 5-mm-thick contiguous slices were performed three times at variable tube voltages of 80 kV, 100 kV, 120 kV, and 140 kV with the same tube current setting of 200 mA and on variable current settings of 50 mA, 100 mA, 150 mA, and 200 mA with the same tube voltage of 80 kV. Radiation doses were measured using a total of 41 thermoluminescent dosimeters (TLDs) placed in the human head phantom. Thirty-six TLDs were inside and three were on the surface of the slice of the X-ray beam center, and two were placed on the surface 3 cm caudal assuming the lens position. Average radiation doses of surface, inside, and lens increased in proportion to the increases of tube voltage and tube current. The lowest inside dose was 87.6±15.3 mGy, and the lowest surface dose was 162.5±6.7 mGy at settings of 80 kV and 50 mA. The highest inside dose was 1,591.5±179.7 mGy, and the highest surface dose was 2,264.6±123.7 mGy at 140 kV-200 mA. At 80 kV-50 mA, the average radiation dose of lens was the lowest at 5.5±0.0 mGy. At 140 kV-200 mA the radiation dose of lens was the highest at 127.2±0.6 mGy. In cerebral CT perfusion study, radiation dose can vary considerably. Awareness of the patient's radiation dose is recommended. (author)

  2. CT in Peyronie's disease

    The diagnostic capabilities of Computed Tomography (CT) in the study of Peyronie's disease are discussed. Twenty-four patients, with different symptoms and a variety of findings on physical examination (from normal to large painful plaques), were studied with thirdgeneration CT equipment. CT defined the normal pattern of the albuginea, as a hyperdense (ranging from 80 to 100 HU) thin and regular line on the periphery of the corpora cavernosa. Pathologic features such as irregularities, disruptions and calcifications of the tunica can be identified; irregularities are shown as circumscribed zones of hyper or hypodensity, disruptions as small or large areas of complete absence of the thin regular line of albuginea. Calcifications are identified as hyperdense nodular or plaquelike areas of 200-300 HU. When physical examination and CT patterns are compared, the reliability of the method is revealed. It provides an accurate definition of the albugineal lesions, imaging all abnormalities detected on physical examination and demostrating additional, non-palpable and doubtful lesions. Phisical examination ans CT findings concurred in 19 cases (79%), whereas disagreement was observed in 5 (12%). In 3 cases CT showed calcified plaques not revealed on physical examination; in 2 cases the plaques revealed by palpation were not confirmed by CT. Furthermore there may be a connection between CT aspects of the albuginea andthe hystological findings in the disease: irregularities could represent the early stage, interruption the mid-stage and calcification irreversible final abnormalities. CT, being a non-traumatic, harmless diagnostic method, improves the clinical evaluation of the patient and can facilitate the choice of most suitable therapeutic modalities, as well as the follow-up of their results

  3. CT of the Stomach

    Mohammad Khajavi

    2011-05-01

    Full Text Available CT of the stomach could be performed with different"nCT modalities and also four-detector CT scan. Stomach"nCT should be used adjunct to barium studies and"nendoscopy. Stomach CT would be used for different"nporposes; primary pathologic conditions, extention"nof the disease and staging. Pathologies studied by CT"ninclude lymphom, leiomyoma, Menetrier's disease,"nHelicobacter pylori Gastritis and esosinophlic Ulrices"nvarices. The stomach is involved by a spectrum of"npatholgic processes ranging from inflammation,"ninfection, benign and malignant diseases. CT is aquired"nto better demonstrate a pathologic process seen or to"nfollow a known lesion. Differential diagnosis is given"nand various criteria are discussed. Distention of the"nstomach by water or 3 percent of contrast as used"nin abdominal and pelvic CT scan is the technique of"ngastric CT. The amount of the contrast would be 1000"ncc of the contrast given in 15-30 min. The last 250 cc is"ngiven immediately before the patient is placed in the"ngantry. You can also use an effervescent given as 4-5"ngm in 3-4 ml of water immediately before scanning."npitfalls. If the stomach is not distended well, the"ngastric wall appears thickened. So a second dose of oral"ncontrast should be given. The normal thickness of the"nwall of the stomach is 7-10 mm. The IV contrast 100-"n110 cc 2-3 mil/sec.

  4. CT in alveolar proteinosis

    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

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

    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

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

    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

  7. Coronary calcium scoring: modelling, predicting and correcting for the effect of CT scanner spatial resolution on Agatston and volume scores

    The purpose of this study was to evaluate the impact of spatial resolution on coronary calcium scoring by x-ray CT, to assess the scoring performance of different CT scanners as they are operated in the field and to correct for the effects of CT scanner spatial resolution on coronary calcium scoring. A phantom consisting of five aluminium wires of known diameter in water was used to measure spatial resolution and to assess scoring performance. Fourteen CT scanners (three helical, two dual, two electron-beam and seven multi-detector) from four manufacturers were evaluated, some under different operating conditions. One scanner was monitored over a 3 month period and again 6 months later. Both spatial resolution and image pixel size significantly affect calcium scoring results. Spatial resolution can be measured with a precision of about 2%. Scanner spatial resolution ranged from 1 to 1.7 mm full-width-half-maximum (FWHM), and pixel size from 0.25 to 0.86 mm. Spatial resolution differences introduce systematic scoring differences that range from 38% to 1100% depending on wire size. Significant temporal variations in spatial resolution were observed in the monitored scanner. By correcting all the scanners to the same target spatial resolution, the standard deviation of individual scanners with respect to a mean value (the spread) can be reduced by 25-70% for different wires. In conclusion, scanner spatial resolution significantly affects calcium scoring and should be controlled for. Scanner performance can change over time. Under ideal conditions, CT scanners should be operated with a standard spatial resolution for calcium scoring. When this is not possible, post-processing correction is a viable alternative

  8. Computed Tomography (CT) -- Sinuses

    Full Text Available ... small amount of radiation is aimed at and passes through the part of the body being examined, ... of CT scan, the machine may make several passes. You may be asked to hold your breath ...

  9. Computed Tomography (CT) -- Head

    Full Text Available ... small amount of radiation is aimed at and passes through the part of the body being examined, ... of CT scan, the machine may make several passes. You may be asked to hold your breath ...

  10. Computed Tomography (CT) -- Sinuses

    Full Text Available ... openings. top of page What are some common uses of the procedure? CT of the sinuses primarily ... to hear and talk to you with the use of a speaker and microphone. top of page ...

  11. Computed Tomography (CT) -- Sinuses

    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 ...

  12. Computed Tomography (CT) -- Head

    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 ...

  13. Computed Tomography (CT) -- Head

    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 ...

  14. Computed Tomography (CT) -- Sinuses

    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 ...

  15. Computed Tomography (CT) -- Head

    Full Text Available ... view of the body's interior. Refinements in detector technology allow nearly all CT scanners to obtain multiple ... a few seconds, and even faster in small children. Such speed is beneficial for all patients but ...

  16. Computed Tomography (CT) -- Sinuses

    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) -- Head

    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: ...

  18. Computed Tomography (CT) -- Head

    Full Text Available ... soft tissue and blood vessels typically provide greater detail than traditional x-rays, particularly of soft tissues ... a shorter period of time, resulting in more detail and additional view capabilities. Modern CT scanners are ...

  19. Computed Tomography (CT) -- Sinuses

    Full Text Available ... soft tissue and blood vessels typically provide greater detail than traditional x-rays, particularly of soft tissues ... a shorter period of time, resulting in more detail and additional view capabilities. Modern CT scanners are ...

  20. Computed Tomography (CT) -- Sinuses

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

  1. Computed Tomography (CT) -- Head

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

  2. Computed Tomography (CT) -- Head

    Full Text Available ... CT scanning provides more detailed information on head injuries, stroke , brain tumors and other brain diseases than ... head is typically used to detect: bleeding, brain injury and skull fractures in patients with head injuries. ...

  3. Computed Tomography (CT) -- Head

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

  4. Computed Tomography (CT) -- Sinuses

    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 ...

  5. Computed Tomography (CT) -- Head

    Full Text Available ... provides more detailed information on head injuries, stroke , brain tumors and other brain diseases than regular radiographs (x- ... especially with a new technique called Perfusion CT. brain tumors. enlarged brain cavities (ventricles) in patients with hydrocephalus . ...

  6. Computed Tomography (CT) -- Head

    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 ...

  7. Computed Tomography (CT) -- Sinuses

    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 ...

  8. Computed Tomography (CT) -- Sinuses

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

  9. Computed Tomography (CT) -- Head

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

  10. Computed Tomography (CT) -- Sinuses

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

  11. CT- and MR colonography

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

    2002-01-01

    . Lately, CT- and MR colonography have emerged as non-invasive methods for colon imaging. METHODS: At present, CTC and MRC require bowel preparation. However, preliminary studies have been carried out without colon preparation. After the colon has been filled with air or contrast, the patient is scanned in...... enema. CONCLUSIONS: With the exponential development in computer processing power, CT- and MR colonography holds the promise for future colon examination with the advantages of non-invasiveness, no need for sedation, and probably no bowel preparation. A major disadvantage, however, is the radiation dose...... during CT 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....

  12. Computed Tomography (CT) -- Sinuses

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

  13. Computed Tomography (CT) -- Head

    Full Text Available ... objects, including jewelry, eyeglasses, dentures and hairpins, may affect the CT images and should be left at ... of the examination the same way that it affects photographs. If contrast material is used, depending on ...

  14. Computed Tomography (CT) -- Sinuses

    Full Text Available ... objects, including jewelry, eyeglasses, dentures and hairpins, may affect the CT images and should be left at ... and whether you have a history of heart disease, asthma, diabetes, kidney disease or thyroid problems. Any ...

  15. Computed Tomography (CT) -- Sinuses

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

  16. Computed Tomography (CT) -- Sinuses

    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 ...

  17. Pediatric CT Scans

    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.

  18. CT urography and hematuria

    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...

  19. Computed Tomography (CT) -- Head

    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 ...

  20. Computed Tomography (CT) -- Sinuses

    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 ...

  1. Computed Tomography (CT) -- Head

    Full Text Available ... medical device of any kind, unlike MRI. A diagnosis determined by CT scanning may eliminate the need ... to radiation. However, the benefit of an accurate diagnosis far outweighs the risk. The effective radiation dose ...

  2. Computed Tomography (CT) -- Sinuses

    Full Text Available ... particularly the lungs, abdomen, pelvis and bones. A diagnosis determined by CT scanning may eliminate the need ... to radiation. However, the benefit of an accurate diagnosis far outweighs the risk. The effective radiation dose ...

  3. Computed Tomography (CT) -- Head

    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 ...

  4. Computed Tomography (CT) -- Head

    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, ...

  5. Computed Tomography (CT) -- Sinuses

    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, ...

  6. CT head in children

    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

  7. Computed Tomography (CT) -- Head

    Full Text Available ... a monitor. CT imaging is sometimes compared to looking into a loaf of bread by cutting the ... feedback Did you find the information you were looking for? Yes No To submit a comment, please ...

  8. Computed Tomography (CT) -- Sinuses

    Full Text Available ... a monitor. CT imaging is sometimes compared to looking into a loaf of bread by cutting the ... feedback Did you find the information you were looking for? Yes No To submit a comment, please ...

  9. Computed Tomography (CT) -- Sinuses

    Full Text Available ... is the procedure performed? The technologist begins by positioning patients on the CT examination table. For a ... understanding of the possible charges you will incur. Web page review process: This Web page is reviewed ...

  10. Computed Tomography (CT) -- Head

    Full Text Available ... is the procedure performed? The technologist begins by positioning you on the CT examination table, usually lying ... understanding of the possible charges you will incur. Web page review process: This Web page is reviewed ...

  11. Computed Tomography (CT) -- Head

    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. ...

  12. Computed Tomography (CT) -- Sinuses

    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 ...

  13. Computed Tomography (CT) -- Head

    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 ...

  14. Computed Tomography (CT) -- Sinuses

    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 ...

  15. Computed Tomography (CT) -- Head

    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 ...

  16. Computed Tomography (CT) -- Sinuses

    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. ...

  17. CT of abdominal trauma

    Soon after it became available for clinical use, cranial CT became the method of choice for evaluating head trauma. Only relatively recently have newer generation full-body scanners been installed at major trauma centers, but experience is rapidly being gained in the utilization of CT for abdominal trauma. CT has proved highly accurate in diagnosing a wide variety of injuries to both intra- and retroperitoneal organs in pediatric and adult patient populations. The impact has been evident not only in decreasing utilization of other diagnostic tests, such as angiography, but also in practical management decisions, such as whether to perform exploratory laparotomy. This chapter details the authors' approach to evaluation of abdominal trauma by CT

  18. Computed Tomography (CT) -- Sinuses

    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 ...

  19. Computed Tomography (CT) -- Head

    Full Text Available ... a gantry. The computer workstation that processes the imaging information is located in a separate control room, ... which are then displayed on a monitor. CT imaging is sometimes compared to looking into a loaf ...

  20. Computed Tomography (CT) -- Sinuses

    Full Text Available ... a gantry. The computer workstation that processes the imaging information is located in a separate control room, ... which are then displayed on a monitor. CT imaging is sometimes compared to looking into a loaf ...

  1. Computed Tomography (CT) -- Sinuses

    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 ...

  2. Computed Tomography (CT) -- Head

    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 ...

  3. Computed Tomography (CT) -- Sinuses

    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) -- Head

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

  5. Computed Tomography (CT) -- Sinuses

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

  6. Computed Tomography (CT) -- Sinuses

    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 ...

  7. Computed Tomography (CT) -- Sinuses

    Full Text Available ... that lasts for at most a minute or two. You may experience a sensation like you have ... CT scanning provides very detailed images of many types of tissue as well as the lungs, bones, ...

  8. Computed Tomography (CT) -- Head

    Full Text Available ... that lasts for at most a minute or two. You may experience a sensation like you have ... CT scanning provides very detailed images of many types of tissue as well as the lungs, bones, ...

  9. Computed Tomography (CT) -- Sinuses

    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 ...

  10. Computed Tomography (CT) -- Head

    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 ...

  11. Computed Tomography (CT) -- Head

    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, ...

  12. Computed Tomography (CT) -- Sinuses

    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, ...

  13. Computed Tomography (CT) -- Head

    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 ...

  14. Computed Tomography (CT) -- Sinuses

    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 ...

  15. Computed Tomography (CT) -- Head

    Full Text Available ... detailed images of many types of tissue as well as the lungs, bones, and blood vessels. CT ... iodine is extremely rare, and radiology departments are well-equipped to deal with them. Because children are ...

  16. Computed Tomography (CT) -- Sinuses

    Full Text Available ... detailed images of many types of tissue as well as the lungs, bones, and blood vessels. CT ... iodine is extremely rare, and radiology departments are well-equipped to deal with them. Because children are ...

  17. Computed Tomography (CT) -- Sinuses

    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 ...

  18. Shoulder CT scan

    CAT scan - shoulder; Computed axial tomography scan - shoulder; Computed tomography scan - shoulder; CT scan - shoulder ... stopping.) A computer creates separate images of the shoulder area. These are called slices. These images can ...

  19. Computed Tomography (CT) -- Head

    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 ...

  20. Computed Tomography (CT) -- Sinuses

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

  1. CT number definition

    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.

  2. CT-Urography

    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

  3. CT spotlight falls on safety

    A brief overview is given on computed tomography (CT). Aspects discussed include the extent of CT use in the UK, the core technology, the 3D information, its applications in diagnostic and radiotherapy procedures and finally patient dose since CT examinations now represent 20% of the total collective dose from all medical and dental x-rays in the UK. The use of CT in the future is then discussed. A CT equipment listing is also provided. (UK)

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

    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.)

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

    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

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

    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.)

  7. 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

    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

  8. Spiral CT of pancreas. Clinical comparison with conventional CT and dynamic CT

    Spiral CT is compared with the dynamic CT and the conventional CT with regard to the enhancement of the pancreas and peripancreatic vessels and the visualisation of anatomic details. Compared with dynamic CT, spiral CT of the pancreatic region in the arterial phase (flow 4 ml/s, delay 15-18 s) leads to a stronger contrast of the peripancreatic vessels and the pancreas (108 vs. 86 HU). In the following spiral CT of the upper abdomen (flow 1 ml/s, delay 70 s), a high enhancement of both arteries and veins could be achieved. Intrapancreatic structures and peripancreatic vessels were better seen in the spiral CT than in the conventional CT. The combination of spiral CT of the pancreatic region in the arterial perfusion phase and spiral CT of the upper abdomen in the arterial-venous phase enables an optimal enhancement of the pancreas and the abdominal vessels and a reliable visualisation of anatomic details. (orig./MG)

  9. CT and MR urography

    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.

  10. Helical CT defecography

    The purpose of this work is to investigate the possible role of Helical CT defecography in pelvic floor disorders by comparing the results of the investigations with those of conventional defecography. The series analyzed consisted of 90 patients, namely 62 women and 28 men, ranging in age 24-82 years. They were all submitted to conventional defecography, and 18 questionable cases were also studied with Helical CT defecography. The conventional examination was performed during the 4 standard phases of resting, squeezing, Valsalva and straining; it is used a remote-control unit. The parameters for Helical CT defecography were: 5 mm beam collimation, pitch 2, 120 KV, 250 m As and 18-20 degrees gantry inclination to acquire coronal images of the pelvic floor. The rectal ampulla was distended with a bolus of 300 mL nonionic iodinated contrast agent (dilution: 3g/cc). The patient wore a napkin and was seated on the table, except for those who could not hold the position and were thus examined supine. Twenty-second helical scans were performed at rest and during evacuation; multiplanar reconstructions were obtained especially on the sagittal plane for comparison with conventional defecographic images. Coronal Helical CT defecography images permitted to map the perineal floor muscles, while sagittal reconstructions provided information on the ampulla and the levator ani. To conclude, Helical CT defecography performed well in study of pelvic floor disorders and can follow conventional defecography especially in questionable cases

  11. CT of thymoma

    Sone, S.; Higashihara, T.; Morimoto, S.; Ikezoe, J.; Arisawa, J. (Osaka Univ. (Japan). Faculty of Medicine)

    1982-08-01

    Based on 17 patients with thymoma (8 with myasthenia gravis and 9 free from it); 1. The effectiveness of CT, conventional radiography and pneumomediastinography in the detection of thymomas was determined and the results compared. 2. The CT findings of thymomas were discussed and the CT features which seemed to suggest malignant thymomas were evaluated. The results were as follows: 1. Of the 17 cass with thymomas, 13 were diagnosed from p-a films, 13 from lateral films, and 16 from CT. Of the 16 thymomas, 14 were diagnosed from lateral tomography. Mass densities were shown in all 15 cases in which pneumomediastinography were performed. 2. Benign thymomas showed round or oval smoothly marginated mass. The fatty plane between the mass and the mediastinal structures was nicely preserved. 3. Malignant thymoma frequently showed a plaque-like mass with more or less irregular or lobulated contours with obliteration of the fatty planes of the cardiovascular structures. Tumor calcification was shown in 4 of 10 malignant thymomas. 4. Slight tumor invasion to the mediastinal pleura and lung was difficult to predict from the CT images.

  12. PET-CT; PET-CT

    Schober, O. [Univeritaetsklinikum Muenster (Germany). Klinik und Poliklinik fuer Nuklearmedizin; Heindel, W. [Univeritaetsklinikum Muenster (Germany). Inst. fuer Klinische Radiologie

    2008-07-01

    Positron emission tomography - computerized tomography (PET-CT) is the fusion of two modern imaging techniques. The book includes the following chapters: 1. fundamentals: radiation protection aspects, radionuclide production, contrast agents, patient preparation, image interpretation; 2. diagnostics of carcinomas: carcinomas in brain, head-throat, thyroid, lungs, intestinal tract, gynecological carcinomas, urinary tract and bladder carcinomas, prostate carcinomas, malignant lymphomas, malignant malinomas, carcinomas in the skeletal system; 3. infections; 4. diagnostics of cardiovascular diseases; 5. diagnostics of neurodegenerative diseases; 6. developments and perspectives, 7. attachments: internet links, glossary, abbreviations.

  13. Axial skeletal CT densitometry

    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.)

  14. CT in dental osseointegration

    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

  15. Normal cranial CT anatomy

    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

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

    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.)

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

    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...

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

    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, ...

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

    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 ...

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

    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 ...

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

    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)

    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 ...

  3. CT of abdominal blunt trauma

    We studied CT findings and interventional radiology including therapeutic procedures in 43 cases with abdominal blunt trauma, retrospectively. All of parenchymal organ's injuries, and injuries of duodenum and retroperitoneum were correctly diagnosed by CT. In 14 cases with only hemoperitoneum or no positive findings on CT, 4 cases were jejunal perforations, and remaining 10 cases were conservatively treated and relieved. We have to take care that the similar CT findings include the opposite results to need surgery and not. (author)

  4. Abdominal CT scan

    ... 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

    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. Computed Tomography (CT) -- Head

    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 ...

  7. Computed Tomography (CT) -- Sinuses

    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. Computed Tomography (CT) -- Sinuses

    Full Text Available ... membranes . help diagnose sinusitis . top of page How should I prepare? You should wear comfortable, loose-fitting clothing to your exam. ... and hairpins, may affect the CT images and should be left at home or removed prior to ...

  9. Abdominal aspergillosis: CT findings

    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. Abdominal aspergillosis: CT findings

    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.

  11. Computed Tomography (CT) -- Head

    Full Text Available ... with a new technique called Perfusion CT. brain tumors. enlarged brain cavities (ventricles) in patients with hydrocephalus . diseases or ... Information and Resources RTAnswers.org Radiation Therapy for Brain Tumors Radiation Therapy for Head and Neck Cancer Others ...

  12. Refining CT colonography methods

    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

  13. Computed Tomography (CT) -- Sinuses

    Full Text Available ... Español More Info Images/Videos News Physician Resources Professions Site Index A-Z Computed Tomography (CT) - Sinuses ... visibility of certain tissues or blood vessels. A nurse or technologist will insert an intravenous (IV) line ...

  14. CT- and MR colonography

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

    2002-01-01

    . Lately, CT- and MR colonography have emerged as non-invasive methods for colon imaging. METHODS: At present, CTC and MRC require bowel preparation. However, preliminary studies have been carried out without colon preparation. After the colon has been filled with air or contrast, the patient is scanned in...

  15. Computed Tomography (CT) -- Sinuses

    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 ...

  16. Computed Tomography (CT) -- Head

    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 ...

  17. Computed Tomography (CT) -- Head

    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

    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 ...

  19. CT image of thymoma

    Morioka, Nobuo; Shudo, Yuji; Jahana, Masanobu; Matsuki, Tsutomu; Kotani, Kazuhiko (Tottori Univ., Yonago (Japan). School of Medicine)

    1983-10-01

    Computor tomographic images of 11 patients who had had thymectomy for myasthenia gravis or thymoma were studied retrospectively. Of those 11 patients, malignant thymoma and benign condition including normal thymus were 6 and 5 respectively. On CT, calcification and lobulation with irregular margin seem to be reliable findings of malignancy. Defect or abscence of fatty plane and non-homogenous density are ancillary.

  20. Computed Tomography (CT) -- Head

    Full Text Available ... back. Straps and pillows may be used to help you maintain the correct position and to help you remain still during the exam. Many scanners ... a physician, may offer you some medication to help you tolerate the CT scanning procedure. If an ...