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Sample records for prospective ecg-triggered 64-slice

  1. Dose reduction using prospective electrocardiograph-triggered axial coronary scan on the 64-slice spiral CT

    International Nuclear Information System (INIS)

    Wang Yanyan; Wu Guogeng; Zhou Cheng; Gao Jianhua; Jiao Sheng; Cao Huizhi

    2008-01-01

    Objective: To compare radiation dose and image quality between prospective electrocardiograph (ECG)-triggered axial scan and retrospective ECG-gated helical scan in coronary 64-slice CT angiography (CTA). Methods: Seventy-seven consecutive patients [group A. Average body mass index (BMI): 24.6, heart rate 0.05). Conclusion: Prospective ECG-triggered axial scan in 64-slice coronary CTA can significantly reduce radiation exposure and the image quality can fulfill clinical diagnostic needs. (authors)

  2. Coronary artery visibility in free-breathing young children with congenital heart disease on cardiac 64-slice CT: dual-source ECG-triggered sequential scan vs. single-source non-ECG-synchronized spiral scan

    Energy Technology Data Exchange (ETDEWEB)

    Goo, Hyun Woo; Yang, Dong Hyun [University of Ulsan College of Medicine, Department of Radiology and Research Institute of Radiology, Asan Medical Center, Seoul (Korea, Republic of)

    2010-10-15

    The potential impact of dual-source ECG-triggered sequential CT scan on coronary artery visibility has not been evaluated in free-breathing young children. To compare coronary artery visibility in free-breathing young children with congenital heart disease on cardiac 64-slice CT between dual-source ECG-triggered sequential (DSET) scan and single-source non-ECG-synchronized spiral (SSNE) scan. In 93 young children, 108 cardiac 64-slice CT examinations were performed during free-breathing. Visibility of coronary arteries and side branches was compared between SSNE and DSET scans. Heart rates and trigger delays for DSET scan were recorded. Effective dose of each scan technique was calculated. Visual grades were significantly higher (P < 0.001 or =0.011) on DSET scan than on SSNE scan except for the distal left anterior descending artery. Coronary arteries were traceable in 79.3% on DSET scan and 54.3% on SSNE scan in the overlapped scan range (P < 0.0001), and 97.1% and 71.9% for the origins and proximal segments (P < 0.0001). Visibility of side branches was improved on DSET scan by a factor of 2.0. Heart rates and trigger delays for DSET scan were 131 {+-} 24 beats per min and 199 {+-} 44 ms, respectively. Effective doses of DSET and SSNE scans were 0.36 {+-} 0.12 mSv and 0.99 {+-} 0.23 mSv, respectively. DSET scan improves visibility of coronary arteries on cardiac 64-slice CT in free-breathing young children with congenital heart disease, compared with SSNE scan. (orig.)

  3. Diagnostic accuracy of sub-mSv prospective ECG-triggering cardiac CT in young infant with complex congenital heart disease.

    Science.gov (United States)

    Gao, Wei; Zhong, Yu Min; Sun, Ai Min; Wang, Qian; Ouyang, Rong Zhen; Hu, Li Wei; Qiu, Han Sheng; Wang, Shi Yu; Li, Jian Ying

    2016-06-01

    To explore the clinical value and evaluate the diagnostic accuracy of sub-mSv low-dose prospective ECG-triggering cardiac CT (CCT) in young infants with complex congenital heart disease (CHD). A total of 102 consecutive infant patients (53 boys and 49 girls with mean age of 2.9 ± 2.4 m and weight less than 5 kg) with complex CHD were prospectively enrolled. Scans were performed on a 64-slice high definition CT scanner with low dose prospective ECG-triggering mode and reconstructed with 80 % adaptive statistical iterative reconstruction algorithm. All studies were performed during free breathing with sedation. The subjective image quality was evaluated by 5-point grading scale and interobserver variability was calculated. The objective image noise (standard deviation, SD) and contrast to noise ratio (CNR) was calculated. The effective radiation dose from the prospective ECG-triggering mode was recorded and compared with the virtual conventional retrospective ECG-gating mode. The detection rate for the origin of coronary artery was calculated. All patients also underwent echocardiography before CCT examination. 81 patients had surgery and their preoperative CCT and echocardiography findings were compared with the surgical results and sensitivity, specificity, positive and negative predictive values and accuracy were calculated for separate cardiovascular anomalies. Heart rates were 70-161 beats per minute (bpm) with mean value of 129.19 ± 14.52 bpm. The effective dose of 0.53 ± 0.15 mSv in the prospective ECG-triggering cardiac CT was lower than the calculated value in a conventional retrospective ECG-gating mode (2.00 ± 0.35 mSv) (p ECG-triggering CCT with sub-mSv effective dose provides excellent imaging quality and high diagnostic accuracy for young infants with complex CHD.

  4. Cerebral angiography with prospective ECG triggering preliminary study of dual-source CT

    International Nuclear Information System (INIS)

    Xue Yuejun; Qian Nong; Shao Yanhui; Pan Changjie; Rong Weiliang; Xu Yiqun

    2012-01-01

    Objective: To study the image quality and radiation dose in dual-source CT cerebral angiography with prospective ECG-triggered sequence mode (step-and-shoot, SAS). Methods: A total of forty-three patients with clinically suspected cerebral vascular disease underwent cerebral CT angiography with prospective ECG-triggering (step-and-shoot, SAS). Data acquisition was at 60% R-R interval of the ECG presentation mode. The post-processing included maximum intensity projection (MIP), multiplanar reformation (MPR) and volume rendering (VR). The CTA image quality, radiation dose and rates of excellent images were evaluated. Results: The CTA image quality score was 4.72 ± 0.50 and 97.7% (42/43) patients had excellent CTA images. The average effective dose of SAS-CTA was (0.22 ± 0.01)mSv, which was lower by 76.31% than that of DE-CTA. Conclusions: Prospective ECG-triggering sequence could be used in cerebral angiography with a significant reduction in radiation dose and diagnostic image quality. (authors)

  5. Impact of heart rate and rhythm on radiation exposure in prospectively ECG triggered computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Luecke, Christian, E-mail: neep@gmx.de [University of Leipzig – Heart Center, Department of Diagnostic and Interventional Radiology, Strümpellstrasse 39, D-04289, Leipzig (Germany); Andres, Claudia; Foldyna, Borek [University of Leipzig – Heart Center, Department of Diagnostic and Interventional Radiology, Strümpellstrasse 39, D-04289, Leipzig (Germany); Nagel, Hans Dieter [Wissenschaft and Technik für die Radiologie, Buchhholz i.d.N (Germany); Hoffmann, Janine; Grothoff, Matthias; Nitzsche, Stefan; Gutberlet, Matthias; Lehmkuhl, Lukas [University of Leipzig – Heart Center, Department of Diagnostic and Interventional Radiology, Strümpellstrasse 39, D-04289, Leipzig (Germany)

    2012-09-15

    Purpose: To evaluate the influence of different heart rates and arrhythmias on scanner performance, image acquisition and applied radiation exposure in prospectively ECG triggered computed tomography (pCT). Materials and methods: An ECG simulator (EKG Phantom 320, Müller and Sebastiani Elektronik GmbH, Munich, Germany) was used to generate different heart rhythms and arrhythmias: sinus rhythm (SR) at 45, 60, 75, 90 and 120/min, supraventricular arrhythmias (e.g. sinus arrhythmia, atrial fibrillation) and ventricular arrhythmias (e.g. ventricular extrasystoles), pacemaker-ECGs, ST-changes and technical artifacts. The analysis of the image acquisition process was performed on a 64-row multidetector CT (Brilliance, Philips Medical Systems, Cleveland, USA). A prospectively triggered scan protocol as used for routine was applied (120 kV; 150 mA s; 0.4 s rotation and exposure time per scan; image acquisition predominantly in end-diastole at 75% R-R-interval, in arrythmias with a mean heart rate above 80/min in systole at 45% of the R-R-interval; FOV 25 cm). The mean dose length product (DLP) and its percentage increase from baseline (SR at 60/min) were determined. Result: Radiation exposure can increase significantly when the heart rhythm deviates from sinus rhythm. ECG-changes leading to a significant DLP increase (p < 0.05) were bifocal pacemaker (61%), pacemaker dysfunction (22%), SVES (20%), ventricular salvo (20%), and atrial fibrillation (14%). Significantly (p < 0.05) prolonged scan time (>8 s) could be observed in bifocal pacemaker (12.8 s), pacemaker dysfunction (10.7 s), atrial fibrillation (10.3 s) and sinus arrhythmia (9.3 s). Conclusion: In prospectively ECG triggered CT, heart rate and rhythm can provoke different types of scanner performance, which can significantly alter radiation exposure and scan time. These results might have an important implication for indication, informed consent and contrast agent injection protocols.

  6. Impact of heart rate and rhythm on radiation exposure in prospectively ECG triggered computed tomography

    International Nuclear Information System (INIS)

    Luecke, Christian; Andres, Claudia; Foldyna, Borek; Nagel, Hans Dieter; Hoffmann, Janine; Grothoff, Matthias; Nitzsche, Stefan; Gutberlet, Matthias; Lehmkuhl, Lukas

    2012-01-01

    Purpose: To evaluate the influence of different heart rates and arrhythmias on scanner performance, image acquisition and applied radiation exposure in prospectively ECG triggered computed tomography (pCT). Materials and methods: An ECG simulator (EKG Phantom 320, Müller and Sebastiani Elektronik GmbH, Munich, Germany) was used to generate different heart rhythms and arrhythmias: sinus rhythm (SR) at 45, 60, 75, 90 and 120/min, supraventricular arrhythmias (e.g. sinus arrhythmia, atrial fibrillation) and ventricular arrhythmias (e.g. ventricular extrasystoles), pacemaker-ECGs, ST-changes and technical artifacts. The analysis of the image acquisition process was performed on a 64-row multidetector CT (Brilliance, Philips Medical Systems, Cleveland, USA). A prospectively triggered scan protocol as used for routine was applied (120 kV; 150 mA s; 0.4 s rotation and exposure time per scan; image acquisition predominantly in end-diastole at 75% R-R-interval, in arrythmias with a mean heart rate above 80/min in systole at 45% of the R-R-interval; FOV 25 cm). The mean dose length product (DLP) and its percentage increase from baseline (SR at 60/min) were determined. Result: Radiation exposure can increase significantly when the heart rhythm deviates from sinus rhythm. ECG-changes leading to a significant DLP increase (p 8 s) could be observed in bifocal pacemaker (12.8 s), pacemaker dysfunction (10.7 s), atrial fibrillation (10.3 s) and sinus arrhythmia (9.3 s). Conclusion: In prospectively ECG triggered CT, heart rate and rhythm can provoke different types of scanner performance, which can significantly alter radiation exposure and scan time. These results might have an important implication for indication, informed consent and contrast agent injection protocols

  7. Double prospectively ECG-triggered high-pitch spiral acquisition for CT coronary angiography: Initial experience

    International Nuclear Information System (INIS)

    Wang, Q.; Qin, J.; He, B.; Zhou, Y.; Yang, J.-J.; Hou, X.-L.; Yang, X.-B.; Chen, J.-H.; Chen, Y.-D.

    2013-01-01

    Aim: To evaluate the feasibility of double prospectively electrocardiogram (ECG)-triggered high-pitch spiral acquisition mode (double high-pitch mode) for coronary computed tomography angiography (CTCA). Materials and methods: One hundred and forty-nine consecutive patients [40 women, 109 men; mean age 58.2 ± 9.2 years; sinus rhythm ≤70 beats/min (bpm) after pre-medication, body weight ≤100 kg] were enrolled for CTCA examinations using a dual-source CT system with 2 × 128 × 0.6 mm collimation, 0.28 s rotation time, and a pitch of 3.4. Double high-pitch mode was prospectively triggered first at 60% and later at 30% of the R–R interval within two cardiac cycles. Image quality was evaluated using a four-point scale (1 = excellent, 4 = non-assessable). Results: From 2085 coronary artery segments, 86.4% (1802/2085) were rated as having a score of 1, 12.3% (257/2085) as score of 2, 1.2% (26/2085) as score of 3, and none were rated as “non-assessable”. The average image quality score was 1.15 ± 0.26 on a per-segment basis. The effective dose was calculated by multiplying the coefficient factor of 0.028 by the dose–length product (DLP); the mean effective dose was 3.5 ± 0.8 mSv (range 1.7–7.6 mSv). The total dosage of contrast medium was 78.7 ± 2.9 ml. Conclusion: Double prospectively ECG-triggered high-pitch spiral acquisition mode provides good image quality with an average effective dose of less than 5 mSv in patients with a heart rate ≤70 bpm

  8. 64-slice spiral CT coronary angiography with prospective electrocardiogram-gating: an initial study

    International Nuclear Information System (INIS)

    Yuan Xuchun; Wang Xianzhu; Liao Wenling; Chen Qin; Deng Huiyi

    2008-01-01

    Objective: To evaluate the feasibility of prospective electrocardiogram (ECG)-gating computed tomography coronary angiography (CTCA). Methods: Sixty patients with suspected or known coronary artery disease underwent 64-slice CTCA using prospective ECG-gating. Multi-planar reconstruction ( MPR), curved-planar reconstruction (CPR), maximum intensity projection (MIP) and volume rendering (VR) were used to demonstrate the coronary arteries. The image quality and radiation dose was evaluated. Results: The mean effective radiation dose was (2.7±0.2) mSv. 93.3% (720/772) segments of all coronary arteries were of diagnostic image quality, 44.2% (341/772)was classified as excellent and 49.1% (379/772)was good. Non-diagnostic coronary segments were found in 6.7% (52/772) of all coronary arteries. There were 5(8.3%) cases with severe coronary stenosis(>75%) or occlusion, 17 (28.4%) cases with moderate stenosis (50%-75%), 18 (30.0%) cases with mild stenosis (<50% )or irregular lumen, 20(33.3%) cases with normal coronary, artery. Conclusion: With a low radiation dose, prospective electrocardiogram (ECG)-gated coronary 64-MSCT angiography has a good potential for the detection of coronary stenosis, especially for excluding coronary artery disease. (authors)

  9. Coronary CT angiography using prospective ECG triggering. High diagnostic accuracy with low radiation dose

    International Nuclear Information System (INIS)

    Arnoldi, E.; Ramos-Duran, L.; Abro, J.A.; Costello, P.; Zwerner, P.L.; Schoepf, U.J.; Nikolaou, K.; Reiser, M.F.

    2010-01-01

    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.) [de

  10. Imaging of pulmonary vein anatomy using low-dose prospective ECG-triggered dual-source computed tomography

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    Blanke, Philipp; Baumann, Tobias; Langer, Mathias; Pache, Gregor [University Hospital Freiburg, Department of Diagnostic Radiology, Freiburg (Germany)

    2010-08-15

    To prospectively investigate the feasibility, image quality and radiation dose estimates for computed tomography angiography (CTA) of the pulmonary veins and left atrium using prospective electrocardiography (ECG)-triggered sequential dual-source (DS) data acquisition at end-systole in patients with paroxysmal atrial fibrillation undergoing radiofrequency ablation. Thirty-five patients (mean age 66.2 {+-} 12.6 years) with paroxysmal atrial fibrillation underwent prospective ECG-triggered sequential DS-CTA with tube current (250 mAs/rotation) centred 250 ms past the R-peak. Tube voltage was adjusted to the BMI (<25 kg/m{sup 2}: 100 kV, >25 kg/m{sup 2}: 120 kV). Presence of motion or stair-step artefacts was assessed. Effective radiation dose was calculated from the dose-length product. All data sets could be integrated into the electroanatomical mapping system. Twenty-two patients (63%) were in sinus rhythm (mean heart rate 69.2 {+-} 11.1 bpm, variability 1.0 {+-} 1.7 bpm) and 13 (37%) showed an ECG pattern of atrial fibrillation (mean heart rate 84.8 {+-} 16.6 bpm, variability 17.9 {+-} 7.5 bpm). Minor step artefacts were observed in three patients (23%) with atrial fibrillation. Mean estimated effective dose was 1.1 {+-} 0.3 and 3.0 {+-} 0.5 mSv for 100 and 120 kV respectively. Imaging of pulmonary vein anatomy is feasible using prospective ECG-triggered sequential data acquisition at end-systole regardless of heart rate or rhythm at the benefit of low radiation dose. (orig.)

  11. Imaging of pulmonary vein anatomy using low-dose prospective ECG-triggered dual-source computed tomography

    International Nuclear Information System (INIS)

    Blanke, Philipp; Baumann, Tobias; Langer, Mathias; Pache, Gregor

    2010-01-01

    To prospectively investigate the feasibility, image quality and radiation dose estimates for computed tomography angiography (CTA) of the pulmonary veins and left atrium using prospective electrocardiography (ECG)-triggered sequential dual-source (DS) data acquisition at end-systole in patients with paroxysmal atrial fibrillation undergoing radiofrequency ablation. Thirty-five patients (mean age 66.2 ± 12.6 years) with paroxysmal atrial fibrillation underwent prospective ECG-triggered sequential DS-CTA with tube current (250 mAs/rotation) centred 250 ms past the R-peak. Tube voltage was adjusted to the BMI ( 2 : 100 kV, >25 kg/m 2 : 120 kV). Presence of motion or stair-step artefacts was assessed. Effective radiation dose was calculated from the dose-length product. All data sets could be integrated into the electroanatomical mapping system. Twenty-two patients (63%) were in sinus rhythm (mean heart rate 69.2 ± 11.1 bpm, variability 1.0 ± 1.7 bpm) and 13 (37%) showed an ECG pattern of atrial fibrillation (mean heart rate 84.8 ± 16.6 bpm, variability 17.9 ± 7.5 bpm). Minor step artefacts were observed in three patients (23%) with atrial fibrillation. Mean estimated effective dose was 1.1 ± 0.3 and 3.0 ± 0.5 mSv for 100 and 120 kV respectively. Imaging of pulmonary vein anatomy is feasible using prospective ECG-triggered sequential data acquisition at end-systole regardless of heart rate or rhythm at the benefit of low radiation dose. (orig.)

  12. Calcium scoring with prospectively ECG-triggered CT: Using overlapping datasets generated with MPR decreases inter-scan variability

    International Nuclear Information System (INIS)

    Rutten, A.; Isgum, I.; Prokop, M.

    2011-01-01

    Objective: To examine the feasibility of reducing the inter-scan variability of prospectively ECG-triggered calcium-scoring scans by using overlapping 3-mm datasets generated from multiplanar reformation (MPR) instead of non-overlapping 3-mm or 1.5-mm datasets. Patients and methods: Seventy-five women (59-79 years old) underwent two sequential prospectively ECG-triggered calcium-scoring scans with 16 mm x 1.5 mm collimation in one session. Between the two scans patients got off and on the table. We performed calcium scoring (Agatston and mass scores) on the following datasets: contiguous 3-mm sections reconstructed from the raw data (A), contiguous 3-mm sections from MPR (B), overlapping 3-mm sections from MPR (C) and contiguous 1.5-mm sections from the raw data (D). To determine the feasibility of the MPR approach, we compared MPR (B) with direct raw data reconstruction (A). Inter-scan variability was calculated for each type of dataset (A-D). Results: Calcium scores ranged from 0 to 1455 (Agatston) and 0 to 279 mg (mass) for overlapping 3-mm sections (C). Calcium scores (both Agatston and mass) were nearly identical for MPR (B) and raw data approaches (A), with inter-quartile ranges of 0-1% for inter-scan variability. Median inter-scan variability with contiguous 3-mm sections (B) was 13% (Agatston) and 11% (mass). Median variability was reduced to 10% (Agatston and mass) with contiguous 1.5-mm sections (D) and to 8% (Agatston) and 7% (mass) with overlapping 3-mm MPR (A). Conclusion: Calcium scoring on MPR yields nearly identical results to calcium scoring on images directly reconstructed from raw data. Overlapping MPR from prospectively ECG-triggered scans improve inter-scan variability of calcium scoring without increasing patient radiation dose.

  13. Impact of 64-slice coronary CT on the management of patients presenting with acute chest pain: results of a prospective two-centre study

    Energy Technology Data Exchange (ETDEWEB)

    Christiaens, Luc [Departement d' imagerie Cardiovasculaire, Assistance Publique- Hopitaux de Paris, Hopital Lariboisiere, Paris (France); CHU de Poitiers, Departement de Cardiologie, Poitiers (France); Duchat, Florent; Boudiaf, Mourad; Fargeaudou, Yann; Ledref, Olivier; Soyer, Philippe [Departement d' imagerie Cardiovasculaire, Assistance Publique- Hopitaux de Paris, Hopital Lariboisiere, Paris (France); Tasu, Jean-Pierre [CHU de Poitiers, Departement de Radiologie, Poitiers (France); Sirol, Marc [Departement d' imagerie Cardiovasculaire, Assistance Publique- Hopitaux de Paris, Hopital Lariboisiere, Paris (France); INSERM UFR U942, Insuffisance Cardiaque et Biomarqueurs, Universite Paris 7 - Denis Diderot, Hopital Lariboisiere, Paris (France); Universite Paris VII - Denis Diderot, Assistance Publique - Hopitaux de Paris, Service de Radiologie Vasculaire, Hopital Lariboisiere, Paris (France)

    2012-05-15

    Our two-centre prospective study evaluates the usefulness of 64-slice coronary computed tomography (CCT) to rule out significant coronary artery stenosis in patients admitted in emergency departments (ED) for acute coronary syndromes (ACS) with low-to-intermediate risk score. Patients (175) admitted for acute chest pain (ACP), unmodified electrocardiogram and first troponin measurement within normal ranges were included. A second troponin measurement and a 64-slice CCT within 24 h were performed. Major adverse cardiac events (MACE) were recorded during follow-up (6 months {+-} 2). 64-slice CCT was either normal or showed non-significant coronary stenosis in the majority of patients (78%). 64-slice CCT depicted significant stenosis (>50% diameter) in 22% of patient whereas initial clinical and biological evaluation was reassuring. For negative CCTs, elevated troponin at second measurement did not modify the strategy or treatment of patients. No MACEs were noted during follow up. In 12% of patients CCT identified unsuspected non-coronary abnormalities. Our study confirms 64-slice CCT utility to rule out significant coronary artery stenosis in 8/10 patients admitted in ED with ACP or ACS with low-to-intermediate risk score. Early discharge with a negative 64-slice CCT is associated with very low risk of cardiac events at 6 months. (orig.)

  14. Prospective ECG-triggered axial CT at 140-kV tube voltage improves coronary in-stent restenosis visibility at a lower radiation dose compared with conventional retrospective ECG-gated helical CT

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    Horiguchi, Jun; Fujioka, Chikako; Kiguchi, Masao; Kohno, Shingo [Hiroshima University Hospital, Department of Clinical Radiology, Hiroshima (Japan); Yamamoto, Hideya; Kitagawa, Toshiro [Hiroshima University, Department of Molecular and Internal Medicine, Division of Clinical Medical Science, Programs for Applied Biomedicine, Graduate School of Biomedical Sciences, Hiroshima (Japan); Ito, Katsuhide [Hiroshima University, Department of Radiology, Division of Medical Intelligence and Informatics, Programs for Applied Biomedicine, Graduate School of Biomedical Sciences, Hiroshima (Japan)

    2009-10-15

    The purpose of this study was to compare coronary 64-slice CT angiography (CTA) protocols, specifically prospective electrocardiograph (ECG)-triggered and retrospective ECG-gated CT acquisition performed using a tube voltage of 140 kV and 120 kV, regarding intracoronary stent imaging. Coronary artery stents (n=12) with artificial in-stent restenosis (50% luminal reduction, 40 HU) on a cardiac phantom were examined by CT at heart rates of 50-75 beats per minute (bpm). The subjective visibility of in-stent restenosis was evaluated with a three-point scale (1 clearly visible, 2 visible, and 3 not visible), and artificial lumen narrowing [(inner stent diameter - measured lumen diameter)/inner stent diameter], lumen attenuation increase ratio [(in-stent attenuation - coronary lumen attenuation)/coronary lumen attenuation], and signal-to-noise ratio of in-stent lumen were determined. The effective dose was estimated. The artificial lumen narrowing (mean 43%), the increase of lumen attenuation (mean 46%), and signal-to-noise ratio (mean 7.8) were not different between CT acquisitions (p=0.12-0.91). However, the visibility scores of in-stent restenosis were different (p<0.05) between ECG-gated CTA techniques: (a) 140-kV prospective (effective dose 4.6 mSv), 1.6; (b) 120-kV prospective (3.3 mSv), 1.8; (c) 140-kV retrospective (16.4-18.8 mSv), 1.9; and (d) 120-kV retrospective (11.0-13.4 mSv), 1.9. Thus, 140-kV prospective ECG-triggered CTA improves coronary in-stent restenosis visibility at a lower radiation dose compared with retrospective ECG-gated CTA. (orig.)

  15. Feasibility and diagnostic accuracy of a low radiation exposure protocol for prospective ECG-triggering coronary MDCT angiography

    International Nuclear Information System (INIS)

    Pontone, G.; Andreini, D.; Bartorelli, A.L.; Bertella, E.; Mushtaq, S.; Foti, C.; Formenti, A.; Chiappa, L.; Annoni, A.; Cortinovis, S.; Baggiano, A.; Conte, E.; Bovis, F.; Veglia, F.; Ballerini, G.; Agostoni, P.; Fiorentini, C.; Pepi, M.

    2012-01-01

    Aim: To compare the feasibility, accuracy, and effective radiation dose (ED) of multidetector computed tomography (MDCT) in the detection of coronary artery disease using a combined ED-saving strategy including prospective electrocardiogram (ECG) triggering with a short x-ray window and a body mass index (BMI)-adapted imaging protocol using adaptive statistical iterative reconstruction (ASIR; group 1), in comparison with a prospective ECG triggering strategy alone (group 2). Materials and methods: One hundred and seventy patients scheduled for invasive coronary angiography (ICA) were evaluated. Fourteen patients were not eligible for MDCT. The remaining 156 patients were randomized to group 1 (78 patients) and group 2 (78 patients). Eight and 11 patients in groups 1 and 2, respectively, were excluded after randomization because the patients’ heart rates were >65 beats/min. MDCT images were assessed for feasibility, signal-to-noise ration (SNR), and contrast-to-noise ratio (CNR), accuracy in detection of coronary stenoses >50% versus ICA and for ED. Results: The feasibility, SNR, CNR, accuracy in a segment-based and patient-based model were similar in both groups (97 versus 95%, 14.5 ± 3.9 versus 14.2 ± 4.1, 16 ± 4.6 versus 16.5 ± 4.4, 95 versus 94% and 97 versus 99%, respectively). The ED in group 1 was 72% lower than in group 2 (2.1 ± 1.2 versus 7.5 ± 1.8 mSv, respectively; p < 0.01). Conclusions: The use of a multi-parametric ED saving protocol results in a significant reduction in ED without a negative impact on accuracy.

  16. Feasibility and diagnostic accuracy of a low radiation exposure protocol for prospective ECG-triggering coronary MDCT angiography

    Energy Technology Data Exchange (ETDEWEB)

    Pontone, G., E-mail: gianluca.pontone@ccfm.it [Centro Cardiologico Monzino, IRCCS, Milan (Italy); Andreini, D. [Centro Cardiologico Monzino, IRCCS, Milan (Italy); Bartorelli, A.L. [Centro Cardiologico Monzino, IRCCS, Milan (Italy); Department of Cardiovascular Sciences, University of Milan, Milan (Italy); Bertella, E.; Mushtaq, S.; Foti, C.; Formenti, A.; Chiappa, L.; Annoni, A.; Cortinovis, S.; Baggiano, A.; Conte, E.; Bovis, F.; Veglia, F.; Ballerini, G. [Centro Cardiologico Monzino, IRCCS, Milan (Italy); Agostoni, P.; Fiorentini, C. [Centro Cardiologico Monzino, IRCCS, Milan (Italy); Department of Cardiovascular Sciences, University of Milan, Milan (Italy); Pepi, M. [Centro Cardiologico Monzino, IRCCS, Milan (Italy)

    2012-03-15

    Aim: To compare the feasibility, accuracy, and effective radiation dose (ED) of multidetector computed tomography (MDCT) in the detection of coronary artery disease using a combined ED-saving strategy including prospective electrocardiogram (ECG) triggering with a short x-ray window and a body mass index (BMI)-adapted imaging protocol using adaptive statistical iterative reconstruction (ASIR; group 1), in comparison with a prospective ECG triggering strategy alone (group 2). Materials and methods: One hundred and seventy patients scheduled for invasive coronary angiography (ICA) were evaluated. Fourteen patients were not eligible for MDCT. The remaining 156 patients were randomized to group 1 (78 patients) and group 2 (78 patients). Eight and 11 patients in groups 1 and 2, respectively, were excluded after randomization because the patients' heart rates were >65 beats/min. MDCT images were assessed for feasibility, signal-to-noise ration (SNR), and contrast-to-noise ratio (CNR), accuracy in detection of coronary stenoses >50% versus ICA and for ED. Results: The feasibility, SNR, CNR, accuracy in a segment-based and patient-based model were similar in both groups (97 versus 95%, 14.5 {+-} 3.9 versus 14.2 {+-} 4.1, 16 {+-} 4.6 versus 16.5 {+-} 4.4, 95 versus 94% and 97 versus 99%, respectively). The ED in group 1 was 72% lower than in group 2 (2.1 {+-} 1.2 versus 7.5 {+-} 1.8 mSv, respectively; p < 0.01). Conclusions: The use of a multi-parametric ED saving protocol results in a significant reduction in ED without a negative impact on accuracy.

  17. Comparative study of image quality and radiation dose between prospective and retrospective ECG gating technique in coronary artery imaging with 64-slice spiral CT

    International Nuclear Information System (INIS)

    Liu Jianxin; Liu Jian; Dou Yanbin; Wang Jichen; Sun Hongyue

    2009-01-01

    Objective: To compare the image quality and radiation dose between prospective ECG-trigering and retrospective ECG gating technique in coronary artery imaging. Methods: 33 patients suspected coronary artery disease were included in this study and divided into experimental group (prospective ECG-triggering coronary artery imaging, heart rate 0.05). The mean DLP of experimental group (234.4 mGy · cm) was DLP of control group (974.4 mGy · cm) 24.1%. The mean effective dose of prospective ECG gating coronary artery imaging was 3.2 mSv. Effective dose reduced 76.47 %. Conclusions: Prospective ECG gating coronary artery imaging can obtain the similar image quality compared with prospective ECG gating coronary artery imaging but the effective dose reduced 76.47 %. Prospective ECG gating coronary artery imaging has clinical value to peoples who are able to not accept high radiation dose and with low heart rate. (authors)

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

    International Nuclear Information System (INIS)

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

    2010-01-01

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

  19. Feasibility of prospectively ECG-triggered high-pitch coronary CT angiography with 30 mL iodinated contrast agent at 70 kVp: initial experience

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Long Jiang; Qi, Li; Tang, Chun Xiang; Zhou, Chang Sheng; Ji, Xue Man; Lu, Guang Ming [Medical School of Nanjing University, Department of Medical Imaging, Jinling Hospital, Nanjing, Jiangsu (China); Wang, Jing [Medical School of Nanjing University, Department of Cardiology, Jinling Hospital, Nanjing, Jiangsu (China); Spearman, James V.; De Cecco, Carlo Nicola; Meinel, Felix G. [Medical University of South Carolina, Department of Radiology and Radiological Science, Charleston, SC (United States); Schoepf, U.J. [Medical School of Nanjing University, Department of Medical Imaging, Jinling Hospital, Nanjing, Jiangsu (China); Medical University of South Carolina, Department of Radiology and Radiological Science, Charleston, SC (United States)

    2014-07-15

    To evaluate the feasibility, image quality and radiation dose of prospectively ECG-triggered high-pitch coronary CT angiography (CCTA) with 30 mL contrast agent at 70 kVp. Fifty-eight patients with suspected coronary artery disease, a body mass index (BMI) of less than 25 kg/m{sup 2}, sinus rhythm and a heart rate (HR) of less than 70 beats per minute (bpm) were prospectively enrolled in this study. Thirty mL of 370 mg I/mL iodinated contrast agent was administrated at a flow rate of 5 mL/s. All patients underwent prospectively ECG-triggered high-pitch CCTA on a second-generation dual-source CT system at 70 kVp using automated tube current modulation. Fifty-six patients (96.6 %) had diagnostic CCTA images and two patients (3.4 %) had one vessel with poor image quality each rated as non-diagnostic. No significant effects of HR, HR variability and BMI on CCTA image quality were observed (all P > 0.05). Effective dose was 0.17 ± 0.02 mSv and the size-specific dose estimate was 1.03 ± 0.13 mGy. Prospectively ECG-triggered high-pitch CCTA at 70 kVp with 30 mL of contrast agent can provide diagnostic image quality at a radiation dose of less than 0.2 mSv in patients with a BMI of less than 25 kg/m{sup 2} and an HR of less than 70 bpm. (orig.)

  20. Prospectively ECG-triggered sequential dual-source coronary CT angiography in patients with atrial fibrillation: comparison with retrospectively ECG-gated helical CT

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Lei; Yang, Lin; Zhang, Zhaoqi [Capital Medical University, Department of Radiology, Beijing Anzhen Hospital, Beijing (China); Wang, Yining; Jin, Zhengyu [Chinese Academy of Medical Sciences, Department of Radiology, Peking Union Medical College Hospital, Beijing (China); Zhang, Longjiang; Lu, Guangming [Nanjing University, Department of Medical Imaging, Jinling Hospital, Clinical School of Medical College, Nanjing, Jiangsu (China)

    2013-07-15

    To investigate the feasibility of applying prospectively ECG-triggered sequential coronary CT angiography (CCTA) to patients with atrial fibrillation (AF) and evaluate the image quality and radiation dose compared with a retrospectively ECG-gated helical protocol. 100 patients with persistent AF were enrolled. Fifty patients were randomly assigned to a prospective protocol and the other patients to a retrospective protocol using a second-generation dual-source CT (DS-CT). Image quality was evaluated using a four-point grading scale (1 = excellent, 2 = good, 3 = moderate, 4 = poor) by two reviewers on a per-segment basis. The coronary artery segments were considered non-diagnostic with a quality score of 4. The radiation dose was evaluated. Diagnostic segment rate in the prospective group was 99.4 % (642/646 segments), while that in the retrospective group was 96.5 % (604/626 segments) (P < 0.001). Effective dose was 4.29 {+-} 1.86 and 11.95 {+-} 5.34 mSv for each of the two protocols (P < 0.001), which was a 64 % reduction in the radiation dose for prospective sequential imaging compared with retrospective helical imaging. In AF patients, prospectively ECG-triggered sequential CCTA is feasible using second-generation DS-CT and can decrease >60 % radiation exposure compared with retrospectively ECG-gated helical imaging while improving diagnostic image quality. (orig.)

  1. The optimal dose reduction level using iterative reconstruction with prospective ECG-triggered coronary CTA using 256-slice MDCT

    International Nuclear Information System (INIS)

    Hou, Yang; Xu, Shu; Guo, Wenli; Vembar, Mani; Guo, Qiyong

    2012-01-01

    Aim: To assess the image quality (IQ) of an iterative reconstruction (IR) technique (iDose 4 ) from prospective electrocardiography (ECG)-triggered coronary computed tomography angiography (coronary CTA) on a 256-slice multi-detector CT (MDCT) scanner and determine the optimal dose reduction using IR that can provide IQ comparable to filtered back projection (FBP). Method and materials: 110 consecutive patients (69 men, 41 women; age: 54 ± 10 years) underwent coronary CTA on a 256-slice MDCT (Brilliance iCT, Philips Healthcare). The control group (Group A, n = 21) were scanned using the conventional tube output (120 kVp, 210 mAs) and reconstructed using FBP. The other 4 groups were scanned with the same kVp but successively reduced tube output as follows: B[n = 15]: 125 mAs; C[n = 22]: 105 mAs; D[n = 36]: 84 mAs: E[n = 16]: 65 mAs) and reconstructed using IR levels of L3 (Group B), L4 (Group C) and L5 (Groups D and E), to compensate for the noise increase. All images were reconstructed using the same kernel (XCB). Two radiologists graded IQ in a blinded fashion on a 4-point scale (4 – excellent, 3 – good, 2 – fair and 1 – poor). Quantitative measurements of CT values, image noise and contrast-to-noise (CNR) were measured in each group. A receiver-operating characteristic (ROC) analysis was performed to determine a radiation reduction threshold up to which excellent IQ was maintained. Results: There were no significant differences in objective noise, SNR and CNR values among Groups A, B, C, D, and E (P = 0.14, 0.09, 0.17, respectively). There were no significant differences in the scores of the subjective IQ between Group A, and Groups B, C, D, E (P = 0.23–0.97). Significant differences in image sharpness and study acceptability were observed between groups A and E (P < 0.05). Using the criterion of excellent IQ (score 4), the ROC curve of dose levels and IQ acceptability established a reduction of 60% of tube output (Group D) as optimum cutoff point (AUC

  2. Prospective ECG triggering reduces prosthetic heart valve-induced artefacts compared with retrospective ECG gating on 256-slice CT

    NARCIS (Netherlands)

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

    2012-01-01

    Objectives Multidetector computed tomography (MDCT) has diagnostic value for the evaluation of prosthetic heart valve (PHV) dysfunction but it is hampered by artefacts. We hypothesised that image acquisition using prospective triggering instead of retrospective gating would reduce artefacts related

  3. Image quality, radiation dose, and diagnostic accuracy of prospectively ECG-triggered high-pitch coronary CT angiography at 70 kVp in a clinical setting: comparison with invasive coronary angiography

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Long Jiang; Qi, Li; Zhou, Chang Sheng; Zhao, Yan E.; Li, Xie; Lu, Guang Ming [Jinling Hospital, Medical School of Nanjing University, Department of Medical Imaging, Nanjing, Jiangsu (China); Wang, Yining; Cao, Jian; Jin, Zhengyu [Peking Union Medical College Hospital, Department of Radiology, Beijing (China); Schoepf, U.J. [Jinling Hospital, Medical School of Nanjing University, Department of Medical Imaging, Nanjing, Jiangsu (China); Medical University of South Carolina, Division of Cardiovascular Imaging, Charleston, SC (United States); Meinel, Felix G. [Medical University of South Carolina, Division of Cardiovascular Imaging, Charleston, SC (United States); Ludwig-Maximilians-University Hospital, Institute for Clinical Radiology, Munich (Germany); Bayer, Richard R. [Medical University of South Carolina, Division of Cardiovascular Imaging, Charleston, SC (United States); Gong, Jian Bin [Jinling Hospital, Medical School of Nanjing University, Department of Cardiology, Nanjing, Jiangsu (China)

    2016-03-15

    To investigate image quality, radiation dose, and diagnostic performance of prospectively ECG-triggered high-pitch coronary CT angiography (CCTA) at 70 kVp compared to invasive coronary angiography (ICA) as reference standard. Forty-three patients underwent prospectively ECG-triggered high-pitch CCTA at 70 kVp using 30 cc (11 g iodine) contrast medium and ICA. Subjective and objective image quality was evaluated for each CCTA study. CCTA performance for diagnosing ≥50 % stenosis was assessed. Results were stratified according to heart rate (HR), body mass index (BMI), Agatston score, and image quality. At CCTA, 94.3 % (500/530) of coronary segments were of diagnostic quality. Using ICA as reference standard, sensitivity and accuracy were 100 % and 93.0 % on a per-patient basis. Per-vessel and per-segment performances were 92.2 % and 89.5 %; 79.5 % and 88.3 %, respectively. No differences were found in diagnostic accuracy between different HR, BMI, and calcification subgroups (all P > 0.05) on a per-patient basis. However, low image quality reduced diagnostic accuracy on a per-patient, per-vessel and per-segment basis (all P < 0.05). The mean effective radiation dose was 0.2 ± 0.0 mSv. Our presented protocol results in an effective radiation dose of 0.2 mSv and high diagnostic accuracy for stenosis detection in a selected, non-obese population. (orig.)

  4. Italian multicenter, prospective study to evaluate the negative predictive value of 16- and 64-slice MDCT imaging in patients scheduled for coronary angiography (NIMISCAD-non invasive multicenter Italian study for coronary artery disease)

    International Nuclear Information System (INIS)

    Marano, Riccardo; Cobelli, Francesco de; Maschio, Alessandro del; Becker, Christoph; Herzog, Christopher; Centonze, Maurizio; Morana, Giovanni; Gualdi, Gian Franco; Ligabue, Guido; Pontone, Gianluca; Catalano, Carlo; Chiappino, Dante; Midiri, Massimo; Simonetti, Giovanni; Marchisio, Filippo; Olivetti, Lucio; Fattori, Rossella; Bonomo, Lorenzo

    2009-01-01

    This was a prospective, multicenter study designed to evaluate the utility of MDCT in the diagnosis of coronary artery disease (CAD) in patients scheduled for elective coronary angiography (CA) using different MDCT systems from different manufacturers. Twenty national sites prospectively enrolled 367 patients between July 2004 and June 2006. Computed tomography (CT) was performed using a standardized/optimized scan protocol for each type of MDCT system (≥16 slices) and compared with quantitative CA performed within 2 weeks of MDCT. A total of 284 patients (81%) were studied by 16-slice MDCT systems, while 66 patients (19%) by 64-slice MDCT scanners. The primary analysis was on-site/off-site evaluation of the negative predictive value (NPV) on a per-patient basis. Secondary analyses included on-site evaluation on a per-artery and per-segment basis. On-site evaluation included 327 patients (CAD prevalence 58%). NPV, positive predictive value (PPV), sensitivity, specificity, and diagnostic accuracy (DA) were 0.91 (95% CI 0.85-0.95), 0.91 (95% CI 0.86-0.95), 0.94 (95% CI 0.89-0.97), 0.88 (95% CI 0.81-0.93), and 0.91 (95% CI 0.88-0.94), respectively. Off-site analysis included 295 patients (CAD prevalence 56%). NPV, PPV, sensitivity, specificity, and DA were 0.73 (95% CI 0.65-0.79), 0.93 (95% CI 0.87-0.97), 0.73 (95% CI 0.65-0.79), 0.93 (95% CI 0.87-0.97), and 0.82 (95% CI 0.77-0.86), respectively. The results of this study demonstrate the utility of MDCT in excluding significant CAD even when conducted by centers with varying degrees of expertise and using different MDCT machines. (orig.)

  5. Prospective ECG triggering versus low-dose retrospective ECG-gated 128-channel CT coronary angiography: comparison of image quality and radiation dose

    International Nuclear Information System (INIS)

    Feng, Q.; Yin, Y.; Hua, X.; Zhu, R.; Hua, J.; Xu, J.

    2010-01-01

    Aim: To evaluate image quality and radiation dose for 128-detector prospective electrocardiogram (ECG)-gated computed tomography coronary angiography (CTCA) compared with a low-dose retrospective ECG-gated imaging protocol. Materials and methods: Thirty-one and 47 patients suspected of having coronary artery disease were enrolled into groups examined using prospective and low-dose retrospective ECG-gated CT protocols respectively. All examinations were performed on a 128-detector CT system (Definition AS, Siemens Healthcare, Forchheim, Germany). Prospective CTCA was performed using following parameters: tube voltage 100 kV; tube current 205 mAs; centre of acquisition window 70% of the RR interval. The tube current for low-dose retrospective ECG-gated CTCA was full dose during 40-70% of the RR interval and partial dose for the rest of RR interval. The pitch varied between 0.2 and 0.5 depending on heart rate and patient size. Image quality of coronary arteries was evaluated using a four-point grading scale. The signal-to-noise ratios (SNRs) of enhanced arteries and myocardium were also measured, corresponding contrast-to-noise ratios (CNRs) were calculated, and the radiation doses received were recorded. Results: There was a significant difference in the image quality scores between the retrospective and prospective gating protocols (Chi-square = 15.331, p = 0.009). There was no significant difference between the SNRs of the contrasted artery and myocardium in these two groups, but the CNRs were increased in the prospective group. The mean radiation dose of prospective gating group was 2.71 ± 0.67 mSv (range, 1.67-3.59 mSv), which was significantly lower than that of the retrospective group (p < 0.001). Conclusion: Prospective CT angiography can achieve lower radiation dose than that of low-dose retrospective CT angiography, with preserved image quality.

  6. Prospective ECG triggering versus low-dose retrospective ECG-gated 128-channel CT coronary angiography: comparison of image quality and radiation dose

    Energy Technology Data Exchange (ETDEWEB)

    Feng, Q.; Yin, Y.; Hua, X.; Zhu, R.; Hua, J. [Department of Radiology, Renji Hospital, Shanghai Jiaotong University School of Medicine, Shanghai (China); Xu, J., E-mail: xujianr@hotmail.co [Department of Radiology, Renji Hospital, Shanghai Jiaotong University School of Medicine, Shanghai (China)

    2010-10-15

    Aim: To evaluate image quality and radiation dose for 128-detector prospective electrocardiogram (ECG)-gated computed tomography coronary angiography (CTCA) compared with a low-dose retrospective ECG-gated imaging protocol. Materials and methods: Thirty-one and 47 patients suspected of having coronary artery disease were enrolled into groups examined using prospective and low-dose retrospective ECG-gated CT protocols respectively. All examinations were performed on a 128-detector CT system (Definition AS, Siemens Healthcare, Forchheim, Germany). Prospective CTCA was performed using following parameters: tube voltage 100 kV; tube current 205 mAs; centre of acquisition window 70% of the RR interval. The tube current for low-dose retrospective ECG-gated CTCA was full dose during 40-70% of the RR interval and partial dose for the rest of RR interval. The pitch varied between 0.2 and 0.5 depending on heart rate and patient size. Image quality of coronary arteries was evaluated using a four-point grading scale. The signal-to-noise ratios (SNRs) of enhanced arteries and myocardium were also measured, corresponding contrast-to-noise ratios (CNRs) were calculated, and the radiation doses received were recorded. Results: There was a significant difference in the image quality scores between the retrospective and prospective gating protocols (Chi-square = 15.331, p = 0.009). There was no significant difference between the SNRs of the contrasted artery and myocardium in these two groups, but the CNRs were increased in the prospective group. The mean radiation dose of prospective gating group was 2.71 {+-} 0.67 mSv (range, 1.67-3.59 mSv), which was significantly lower than that of the retrospective group (p < 0.001). Conclusion: Prospective CT angiography can achieve lower radiation dose than that of low-dose retrospective CT angiography, with preserved image quality.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2011-07-15

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

  8. Different contrast injection protocols for 64-slice spiral CT coronary angiography

    International Nuclear Information System (INIS)

    Lu Jinguo; Lv Bing; Bai Hua; Tang Xiang; Yang Xinling; Jiang Shiliang; Dai Ruiping; Qiu Jinhai; Chen Tao

    2008-01-01

    Objective: To determine the optimal contrast protocols for 64-slice spiral CT coronary angiography in order to reduce the volume of contrast injection. Methods: One hundred fifty patients scheduled to undergo 64-slice spiral CT coronary angiography were prospectively randomized into the following five groups with different injection protocols: group 1: uniphasic injection without a flush; group 2: biphasic injection with a flush; group 3, group 4 and group 5 : triphasic injection with a diluted contrast material with 3:7, 5:5, 7:3 contrast/saline ratio respectively. Attenuation was measured in the right atrium, right ventricle, left atrium, left ventricle, ascending aorta, right coronary artery and left coronary artery and analyzed with single factor variance test (ANOVA). The quality of the coronary artery images was evaluated and compared using person Chi-Square. Results: The total contrast material volume were (67.0±5.3) ml, (59.9±4.9) ml, (62.9±3.2) ml, (69.2±5.7) ml and (70.9±4.6) ml in five groups respectively (F=27.43, P 2 =18.81, P 2 =31.44, P<0.01). The artifacts in the superior vena cava in group 1 was the most, and in group 2 was the least. The mean enhancement values of right and left coronary arteries in group 2 were significantly greater than those in other groups (F=2.47 and 4.10, P<0.05). The visualization of both left ventricle and right ventricle cavities was the best in group 3. Conclusion: Biphasic injection and triphasic injection are better than uniphasic injection for 64-slice spiral CT coronary angiography and triphasic injection is better than biphasic injection for the visualization of both left ventricle and right ventricle cavities. (authors)

  9. In the workup of patients with obscure gastrointestinal bleed, does 64-slice MDCT have a role?

    International Nuclear Information System (INIS)

    Kulkarni, Chinmay; Moorthy, Srikanth; Sreekumar, KP; Rajeshkannan, R; Nazar, PK; Sandya, CJ; Sivasubramanian, S; Ramchandran, PV

    2012-01-01

    The purpose was to prospectively determine the sensitivity of 64-slice MDCT in detecting and diagnosing the cause of obscure gastrointestinal bleed (OGIB). Our study included 50 patients (male 30, female 20) in the age range of 3–82 years (average age: 58.52 years) who were referred to our radiology department as part of their workup for clinically evident gastrointestinal (GI) bleed or as part of workup for anemia (with and without positive fecal occult blood test). All patients underwent conventional upper endoscopy and colonoscopy before undergoing CT scan. Following a noncontrast scan, all patients underwent triple-phase contrast CT scan using a 64-slice CT scan system. The diagnostic performance of 64-slice MDCT was compared to the results of capsule endoscopy, 99m-technetium-labeled red blood cell scintigraphy (99mTc-RBC scintigraphy), digital subtraction angiography, and surgery whenever available. CT scan showed positive findings in 32 of 50 patients. The sensitivity, specificity, positive predictive value, and negative predictive values of MDCT for detection of bleed were 72.2%, 42.8%, 81.2%, and 44.4%, respectively. Capsule endoscopy was done in 15 patients and was positive in 10 patients; it had a sensitivity of 71.4%. Eleven patients had undergone 99mTc-RBC scintigraphy prior to CT scan, and the result was positive in seven patients (sensitivity 70%). Digital subtraction angiography was performed in only eight patients and among them all except one patient showed findings consistent with the lesions detected on MDCT. MDCT is a sensitive and noninvasive tool that allows rapid detection and localization of OGIB. It can be used as the first-line investigation in patients with negative endoscopy and colonoscopy studies. MDCT and capsule endoscopy have complementary roles in the evaluation of OGIB

  10. Evaluation of dose exposure in 64-slice CT colonography

    Energy Technology Data Exchange (ETDEWEB)

    Luz, O.; Trabold, T.; Kopp, A.F.; Claussen, C.D.; Heuschmid, M. [University Hospital Tuebingen, Department of Diagnostic Radiology, Tuebingen (Germany); Buchgeister, M.; Klabunde, M. [University of Tuebingen, Institute of Medical Physics, Tuebingen (Germany)

    2007-10-15

    The radiation exposure of four different 64-slice MDCT-colonography (CTC) protocols was evaluated using an Alderson-Rando phantom. Protocols using 30 mAs (collimation 20 x 1.2mm), 50 mAs (collimation 20 x 1.2 and 64 x 0.6mm) and 80 mAs (20 x 1.2 mm) representing screening low-dose, routine, narrow collimation and oncologic staging setups were measured with an Alderson-Rando phantom (Alderson Research Laboratories Inc.). Scans were performed on a 64-row MDCT (SOMATOM Sensation 64, Siemens) simulating the prone and supine positions with a constant voltage of 120 kV. Dose values (male/female) were 2.5/2.9, 3.8/4.2, 4.2/4.5 and 5.7/6.4 mSv for 30, 50 (20 x 1.2 and 64 x 0.6 mm) and 80 mAs, respectively. Measurements showed an elevated dose for females (11.5% mean; compared to males). Use of narrow collimation combined with 50 mAs resulted in a small increase of dose exposure of 10.5 (male) and 7.1% (female). Gonad doses ranged from 0.9 to 2.6 mSv (male) and from 1.5 to 3.5 mSv (female). In all protocols, the stomach wall, lower colon, urinary bladder and liver were slightly more highly exposed (all <2.3 mSv) than the other organs, and the breast dose was <0.3 mSv in every setup. Values of radiation exposure in 64- and 16-slice CTC differ only marginally when using the narrow collimation. In 64-slice CTC, the use of narrow (64 x 0.6 mm) collimation shows slightly elevated dose values compared to wider (20 x 1.2 mm) collimation. (orig.)

  11. Evaluation of dose exposure in 64-slice CT colonography

    International Nuclear Information System (INIS)

    Luz, O.; Trabold, T.; Kopp, A.F.; Claussen, C.D.; Heuschmid, M.; Buchgeister, M.; Klabunde, M.

    2007-01-01

    The radiation exposure of four different 64-slice MDCT-colonography (CTC) protocols was evaluated using an Alderson-Rando phantom. Protocols using 30 mAs (collimation 20 x 1.2mm), 50 mAs (collimation 20 x 1.2 and 64 x 0.6mm) and 80 mAs (20 x 1.2 mm) representing screening low-dose, routine, narrow collimation and oncologic staging setups were measured with an Alderson-Rando phantom (Alderson Research Laboratories Inc.). Scans were performed on a 64-row MDCT (SOMATOM Sensation 64, Siemens) simulating the prone and supine positions with a constant voltage of 120 kV. Dose values (male/female) were 2.5/2.9, 3.8/4.2, 4.2/4.5 and 5.7/6.4 mSv for 30, 50 (20 x 1.2 and 64 x 0.6 mm) and 80 mAs, respectively. Measurements showed an elevated dose for females (11.5% mean; compared to males). Use of narrow collimation combined with 50 mAs resulted in a small increase of dose exposure of 10.5 (male) and 7.1% (female). Gonad doses ranged from 0.9 to 2.6 mSv (male) and from 1.5 to 3.5 mSv (female). In all protocols, the stomach wall, lower colon, urinary bladder and liver were slightly more highly exposed (all <2.3 mSv) than the other organs, and the breast dose was <0.3 mSv in every setup. Values of radiation exposure in 64- and 16-slice CTC differ only marginally when using the narrow collimation. In 64-slice CTC, the use of narrow (64 x 0.6 mm) collimation shows slightly elevated dose values compared to wider (20 x 1.2 mm) collimation. (orig.)

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

    International Nuclear Information System (INIS)

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

    2003-01-01

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

  13. Comparison of 64-slice computed tomography angiography and coronary angiography for the detection and assessment of coronary artery disease in patients with angina: A systematic review

    International Nuclear Information System (INIS)

    Powell, H.; Cosson, P.

    2013-01-01

    Background: Coronary artery disease (CAD) is the leading cause of death in Western countries. It presents itself in various ways, the commonest being angina. According to the Royal College of Radiologist referral guidelines, Coronary Angiography (CA) is currently the gold standard for diagnosis and evaluation of CAD. However, due to the invasive nature and expense of CA there is a perceived need for a primary non-invasive imaging modality to supersede it. Computed tomography angiography (CTA), utilising 64-slice technology, may be a less invasive alternative to CA. Aim: To consider the research evidence for the current gold standard diagnostic test for CAD. Specifically, which is more sensitive and specific for detecting CAD in patients with angina; 64-slice CTA or CA? Inclusion Criteria: Prospective, non-randomised control trials and diagnostic accuracy studies comparing 64-slice CTA and CA were included. Participants were adults with angina with suspected or known CAD. Method: An electronic search of the databases; AMED, CINAHL, Cochrane Library, EMBASE, MEDLINE and Science Direct, was conducted between January 2004 and April 2012. Secondary hand-searching of grey literature was undertaken. Two reviewers independently determined studies for inclusion, assessed quality, using SIGN50, and extracted data. Diagnostic value of 64-slice CTA and CA was compared and analysed at patient and segment level. Results: Ten studies were included in the critical review enrolling 1188 patients. At patient level sensitivity for 64-slice CTA ranged from 88% to 100%, specificity 64–92%, PPV 86–97% and NPV 76.9–100%. At segment level sensitivity for 64-slice CTA ranged from 73% to 100%, specificity 83–98%, PPV 47–90% and NPV 89–100% Conclusion: At both patient and segment level, 64-slice CTA is a highly sensitive and specific non-invasive alternative to CA for diagnosis of significant stenosis in patients with angina. For standalone diagnosis of CAD current research would

  14. Comparison between retrospective gating and ECG triggering in magnetic resonance velocity mapping

    DEFF Research Database (Denmark)

    Søndergaard, L; Ståhlberg, F; Thomsen, C

    1993-01-01

    ECG-triggered cinematographic studies of the cardiovascular system are hampered by several technical restrictions such as the inability to image end-diastole, ghosting, varying signal intensity, and phase contributions from eddy currents. Retrospective gating may solve these problems, but involves...... of flow pulses. However, by reducing the time window retrospectively gated flow measurements were in good agreement with those that are ECG triggered. When fulfilling the demand of a narrow time window for interpolation, retrospective gating offers several advantages in MR velocity mapping....

  15. Role of whole-body 64-slice multidetector computed tomography in treatment planning for multiple myeloma.

    Science.gov (United States)

    Razek, Ahmed Abdel Khalek Abdel; Ezzat, Amany; Azmy, Emad; Tharwat, Nehal

    2013-08-01

    The authors evaluated the role of whole-body 64-slice multidetector computed tomography (WB-MDCT) in treatment planning for multiple myeloma. This was a prospective study of 28 consecutive patients with multiple myeloma (19 men, nine women; age range, 51-73 years; mean age, 60 years) who underwent WB-MDCT and conventional radiography (CR) of the skeleton. The images were interpreted for the presence of bony lesions, medullary lesions, fractures and extraosseous lesions. We evaluated any changes in treatment planning as a result of WB-MDCT findings. WB-MDCT was superior to CR for detecting bony lesions (p=0.001), especially of the spine (p=0.001) and thoracic cage (p=0.006). WB-MDCT upstaged 14 patients, with a significant difference in staging (p=0.002) between WB-MDCT and CR. Medullary involvement either focal (n=6) or diffuse (n=3) had a positive correlation with the overall score (r=0.790) and stage (r=0.618) of disease. Spine fractures were better detected at WB-MDCT (n=4) than at CR (n=2). Extraosseous soft tissue lesions (n=7) were detected only at WB-MDCT. Findings detected at the WB-MDCT led to changes in the patient's treatment plan in 39% of cases. Upstaging of seven patients (25%) altered the medical treatment plan, and four of 28 (14%) patients required additional radiotherapy (7%) and vertebroplasty (7%). We conclude that WB-MDCT has an impact on treatment planning and prognosis in patients with multiple myeloma, as it has high rate of detecting cortical and medullary bone lesions, spinal fracture and extraosseous lesions. This information may alter treatment planning in multiple myeloma due to disease upstaging and detection of spine fracture and extraosseous spinal lesions.

  16. Reverse Redistribution in Myocardial Perfusion Imaging: Revisited with 64-slice MDCT

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Min Kyung; Kim, Jeong Ho; Hwang, Kyung Hoon; Choi, In Suck; Choi, Soo Jin; Choe, Won Sick [Gachon University Gil Hospital, Incheon (Korea, Republic of); Yoon, Min Ki [Good Samaritan Hospital, Pohang (Korea, Republic of)

    2010-06-15

    The authors report myocardial perfusion imaging of a patient showing reverse redistribution (RR) and a 64-slice multidetector-row computed tomography (MDCT) with corresponding findings. The patient had subendocardial myocardial infarction (MI) with positive electrocardiogram (EMG) findings and elevated levels of cardiac isoenzymes. Experiencing this case emphasizes the importance of complementary correlation of a new diagnostic modality that helps us to understand the nature of RR.

  17. Diagnostic accuracy of 64-slice multidetector CT for detection of in-stent restenosis in an unselected, consecutive patient population

    Energy Technology Data Exchange (ETDEWEB)

    Haraldsdottir, Sigurdis, E-mail: sigurdisha@gmail.com [Boston Medical Center, 72 East Concord Street (Evans 124), Boston, MA, 02118 (United States); Gudnason, Thorarinn, E-mail: thorgudn@landspitali.is [Landspitali University Hospital, Hringbraut, 101 Reykjavik (Iceland); Sigurdsson, Axel F., E-mail: axelfsig@landspitali.is [Landspitali University Hospital, Hringbraut, 101 Reykjavik (Iceland); Gudjonsdottir, Jonina, E-mail: jonina@rd.is [Rontgen Domus Medica, Egilsgata 3, 101 Reykjavik (Iceland); Lehman, Sam J., E-mail: slehman@partners.org [Massachusetts General Hospital, 165 Cambridge Street, Suite 400, Boston, MA 02114 (United States); Eyjolfsson, Kristjan, E-mail: kristey@landspitali.is [Landspitali University Hospital, Hringbraut, 101 Reykjavik (Iceland); Scheving, Sigurpall S., E-mail: sigurpal@landspitali.is [Landspitali University Hospital, Hringbraut, 101 Reykjavik (Iceland); Gibson, C. Michael, E-mail: mgibson@perfuse.org [Beth Israel Deaconess Medical Center, 330 Brookline Avenue, Boston, MA 02115 (United States); Hoffmann, Udo, E-mail: uhoffmann@partners.org [Massachusetts General Hospital, 165 Cambridge Street, Suite 400, Boston, MA 02114 (United States); Jonsdottir, Birna, E-mail: birna@rd.is [Rontgen Domus Medica, Egilsgata 3, 101 Reykjavik (Iceland); Andersen, Karl, E-mail: andersen@landspitali.is [Landspitali University Hospital, Hringbraut, 101 Reykjavik (Iceland)

    2010-11-15

    Objectives: To investigate the diagnostic accuracy of 64-slice multidetector computed tomography (64-CT) for detection of in-stent restenosis (ISR) in an unselected, consecutive patient population. Background: Detection of in-stent restenosis by cardiac CT would be a major advance for the evaluation of patients suspected of having ISR. However, the diagnostic accuracy of current generation 64-CT in this context is not fully established. Methods: We conducted a prospective study on patients with stable angina or acute coronary syndrome with no prior history of coronary artery disease. Six months after percutaneous coronary intervention (PCI) with stent placement they underwent a 64-CT scan (Toshiba Multi-Slice Aquilion 64) and consequently a repeat coronary angiography for comparison. Cardiac CT data sets were analyzed for the presence of in-stent restenosis by two independent expert readers blinded to the coronary angiographic data. Results: Ninety-three patients with a total of 140 stents were evaluated. Males comprised 82% of the study group and the mean age was 63 {+-} 10 years. The mean time from PCI to the repeat coronary angiography was 208 {+-} 37 days and the mean time from 64-CT to repeat coronary angiography was 3.7 {+-} 4.9 days. The restenosis rate according to coronary angiography was 26%. Stent diameter, strut thickness, heart rate and body mass index (BMI) significantly affected image quality. The sensitivity, specificity, positive and negative predictive values of 64-CT for detection of in-stent restenosis were 27%, 95%, 67% and 78%, respectively. Conclusions: Current generation, 64-slice CT, remains limited in its ability to accurately detect in-stent restenosis.

  18. Adolescent Kawasaki disease: usefulness of 64-slice CT coronary angiography for follow-up investigation

    Energy Technology Data Exchange (ETDEWEB)

    Carbone, Iacopo; Cannata, David; Algeri, Emanuela; Galea, Nicola; Napoli, Alessandro; Catalano, Carlo; Passariello, Roberto; Francone, Marco [Sapienza University of Rome, Department of Radiological, Onchological and Anatomopathological Sciences, Policlinico Umberto I, Rome (Italy); De Zorzi, Andrea [Bambino Gesu Hospital, Cardiology Division, Rome (Italy); Bosco, Giovanna; D' Agostino, Rita [Sapienza University of Rome, Unit of Paediatric Cardiology, Policlinico Umberto I, Rome (Italy); Menezes, Leon [University College of London, Institute of Nuclear Medicine, London (United Kingdom)

    2011-09-15

    Kawasaki disease (KD) is a systemic vasculitis that mainly affects coronary arteries in children, and requires regular follow-up from the time of diagnosis. To evaluate the feasibility of 64-slice CT angiography (CTA) for follow-up of patients with KD using previously performed invasive catheter coronary angiography (CCA) as reference standard. The study group comprised 12 patients (age 17.6 {+-} 2.9 years, mean{+-}SD) with a diagnosis of KD and a previously performed CCA (interval, 32.6 {+-} 13.5 months) who underwent 64-slice cardiac CTA. The quality of the images for establishing the presence of coronary abnormalities was determined by two observers. The CTA findings were compared with those from the prior CCA. Adequate image quality was obtained in all patients. Mean effective dose for CTA was 6.56 {+-} 0.95 mSv. CTA allowed accurate identification, characterization and measurement of all coronary aneurysms (n = 32), stenoses (n = 3) and occlusions (n = 9) previously demonstrated by CCA. One patient with disease progression went on to have percutaneous coronary intervention. Coronary lesions were reliably evaluated by 64-slice CTA in the follow-up of compliant patients with KD, reducing the need for repeated diagnostic invasive CCA. Hence, in an adequately selected patient population, the role of CCA could be limited almost only to therapeutic procedures. (orig.)

  19. Measurement of slice sensitivity profile for a 64-slice spiral CT system

    International Nuclear Information System (INIS)

    Liu Chuanya; Qin Weichang; Wang Wei; Lu Chuanyou

    2006-01-01

    Objective: To measure and evaluate slice sensitivity profile (SSP) and the full width at half-maximum(FWHM) for a 64-slice spiral CT system. Methods: Using the same CT technique and body mode as those used for clinical CT, delta phantom was scanned with Somatom Sensation 64-slice spiral CT. SSPs and FWHM were measured both with reconstruction slice width of 0.6 mm at pitch=0.50, 0.75, 1.00, 1.25, 1.50 and with reconstruction slice width of 0.6, 1.0, 1.5 mm at pitch=1 respectively. Results: For normal slice width of 0. 6 mm, the measured FWHM, i.e. effective slice width, is 0.67, 0.67, 0.66, 0.69, 0.69 mm at different pitch. All the measured FWHM deviate less than 0.1 mm from the nominal slice width. The measured SSPs are symmetrical, bell-shaped curves without far-reaching tails, and show only slight variations as a function of the spiral pitch. When reconstruction slice width increase, relative SSP become wider. Conclusions: The variation of pitch hardly has effect all on SSP, effective slice width, and z-direction spatial resolution for Sensation 64-slice spiral CT system, which is helpful to optimize CT scanning protocol. (authors)

  20. Clinical application of 64-slice spiral CT in the diagnosis of the Tetralogy of Fallot

    International Nuclear Information System (INIS)

    Wang Ximing; Wu Lebin; Sun Cong; Liu Cheng; Chao, Bao-Ting; Han Bo; Zhang Yunting; Chen Haisong; Li Zhenjia

    2007-01-01

    Objective: To explore the clinical application of 64-slice spiral CT in the diagnosis of the Tetralogy of Fallot. Methods: Eighteen patients with diagnosed Tetralogy of Fallot underwent cardiac CT angiography with 64-slice CT (CTA). Two- and three-dimensional images were used for diagnosing in all cases by means of MPR (coronal, sagital and oblique), cMPR, MIP and VRT. Results: All patients had ventricular septal defect, pulmonary stenosis and hypertrophy of right ventricle. The morphologic features of Tetralogy of Fallot were equal to echocardiography. Patent ductus arteriosus (PDA) were detected on eight patients. Main coronary artery branches and partial sub-branches were visualized in all patients. Abnormal coronary arteries were found in seven cases: both left and right main coronary artery arising from the right aortic sinus one case, right main coronary artery and circumflex (CX) arising from the right aortic sinus one case, left anterior descending (LAD) and CX arising from left aortic sinus directly one case, left and right coronary artery arising from back and front of the aortic sinus, respectively, three cases. Pulmonary artery branch stenosis was found in 12 cases and branch pulmonary artery dilation noticed in 1 case. Double superior vena cava was also found in one case. According to the surgery the diagnostic accuracy of CT and Echocardiography was 95.45 and 83.33%, respectively. Conclusion: Two- and three-dimensional 64-slice CTA not only show the overall anatomical structure of the heart, but also show coronary and pulmonary arteries. With these results, evaluation of coronary anomalies and pulmonary artery stenosis with 64-MSCT is extremely valuable for planning the operative procedure on the patients with Tetralogy of Fallot

  1. Clinical application of 64-slice spiral CT in the diagnosis of the Tetralogy of Fallot

    Energy Technology Data Exchange (ETDEWEB)

    Wang Ximing [Tianjin Medical University, Tianjin City (China) and Shandong Medical Imaging Research Institute, Jinan City, Shandong Province 250021 (China)], E-mail: wxming369@163.com.cn; Wu Lebin [Shandong Medical Imaging Research Institute, Jinan City, Shandong Province 250021 (China); Sun Cong [Shandong Medical Imaging Research Institute, Jinan City, Shandong Province 250021 (China); Shandong University Medical College, Shandong Jinan 250012 (China); Liu Cheng [Shandong Medical Imaging Research Institute, Jinan City, Shandong Province 250021 (China); Chao, Bao-Ting [Shandong University Medical College, Shandong Jinan 250012 (China); Han Bo [Shandong Provincial Hospital Pediatric Department, Shandong, Jinan 250021 (China); Zhang Yunting [Tianjin Medical University, General Hospital MR Department, Tianjin City (China); Chen Haisong [Shandong Medical Imaging Research Institute, Jinan City, Shandong Province 250021 (China); Shandong University Medical College, Shandong Jinan 250012 (China); Li Zhenjia [Shandong Medical Imaging Research Institute, Jinan City, Shandong Province 250021 (China)

    2007-11-15

    Objective: To explore the clinical application of 64-slice spiral CT in the diagnosis of the Tetralogy of Fallot. Methods: Eighteen patients with diagnosed Tetralogy of Fallot underwent cardiac CT angiography with 64-slice CT (CTA). Two- and three-dimensional images were used for diagnosing in all cases by means of MPR (coronal, sagital and oblique), cMPR, MIP and VRT. Results: All patients had ventricular septal defect, pulmonary stenosis and hypertrophy of right ventricle. The morphologic features of Tetralogy of Fallot were equal to echocardiography. Patent ductus arteriosus (PDA) were detected on eight patients. Main coronary artery branches and partial sub-branches were visualized in all patients. Abnormal coronary arteries were found in seven cases: both left and right main coronary artery arising from the right aortic sinus one case, right main coronary artery and circumflex (CX) arising from the right aortic sinus one case, left anterior descending (LAD) and CX arising from left aortic sinus directly one case, left and right coronary artery arising from back and front of the aortic sinus, respectively, three cases. Pulmonary artery branch stenosis was found in 12 cases and branch pulmonary artery dilation noticed in 1 case. Double superior vena cava was also found in one case. According to the surgery the diagnostic accuracy of CT and Echocardiography was 95.45 and 83.33%, respectively. Conclusion: Two- and three-dimensional 64-slice CTA not only show the overall anatomical structure of the heart, but also show coronary and pulmonary arteries. With these results, evaluation of coronary anomalies and pulmonary artery stenosis with 64-MSCT is extremely valuable for planning the operative procedure on the patients with Tetralogy of Fallot.

  2. Cardiac CT angiography after coronary artery surgery in children using 64-slice CT scan

    International Nuclear Information System (INIS)

    Marini, Davide; Agnoletti, Gabriella; Brunelle, Francis; Sidi, Daniel; Bonnet, Damien; Ou, Phalla

    2009-01-01

    Objective: The purpose of this study was to compare the diagnostic accuracy of 64-slice CT with that of invasive angiography in the detection of graft and/or coronary angioplasty stenosis in children who had undergone coronary artery surgery. Population and methods: Fifteen consecutive children (8 male and 7 female; age 9.2 ± 6.1 years) underwent 64-slice CT because of chest pain or ECG changes mean 4.8 ± 3.7 years after surgical coronary artery surgery; 10 patients had coronary angioplasty using a patch from the saphenous vein, four had mammary artery bypass, and one had saphenous vein bypass. Six main segments of the coronary arteries and all the bypass graft considered as a single segment were analyzed and compared with invasive angiography used as the reference standard. Results: CT correctly identified the four children with coronary angioplasty and mammary graft lesions that were confirmed by conventional angiography: one patient had a significant stenosis (>50% stenosis) at the mammary bypass graft anastomosis site; three other had non-significant stenosis (<50% stenosis) including a mild lesion of the saphenous vein patch in two patients and a mild lesion at the anastomosis site of the mammary bypass in one. All segments identified as normal by CT in the other 11 children were also found to be normal by conventional angiography. Conclusion: In centers expert in this technique, 64-slice CT scanning is a promising, rapid, and useful diagnostic technique for evaluating both coronary angioplasty and bypass graft lesions in children who had undergone coronary artery surgery.

  3. The preliminary exploration of 64-slice volume computed tomography in the accurate measurement of pleural effusion.

    Science.gov (United States)

    Guo, Zhi-Jun; Lin, Qiang; Liu, Hai-Tao; Lu, Jun-Ying; Zeng, Yan-Hong; Meng, Fan-Jie; Cao, Bin; Zi, Xue-Rong; Han, Shu-Ming; Zhang, Yu-Huan

    2013-09-01

    Using computed tomography (CT) to rapidly and accurately quantify pleural effusion volume benefits medical and scientific research. However, the precise volume of pleural effusions still involves many challenges and currently does not have a recognized accurate measuring. To explore the feasibility of using 64-slice CT volume-rendering technology to accurately measure pleural fluid volume and to then analyze the correlation between the volume of the free pleural effusion and the different diameters of the pleural effusion. The 64-slice CT volume-rendering technique was used to measure and analyze three parts. First, the fluid volume of a self-made thoracic model was measured and compared with the actual injected volume. Second, the pleural effusion volume was measured before and after pleural fluid drainage in 25 patients, and the volume reduction was compared with the actual volume of the liquid extract. Finally, the free pleural effusion volume was measured in 26 patients to analyze the correlation between it and the diameter of the effusion, which was then used to calculate the regression equation. After using the 64-slice CT volume-rendering technique to measure the fluid volume of the self-made thoracic model, the results were compared with the actual injection volume. No significant differences were found, P = 0.836. For the 25 patients with drained pleural effusions, the comparison of the reduction volume with the actual volume of the liquid extract revealed no significant differences, P = 0.989. The following linear regression equation was used to compare the pleural effusion volume (V) (measured by the CT volume-rendering technique) with the pleural effusion greatest depth (d): V = 158.16 × d - 116.01 (r = 0.91, P = 0.000). The following linear regression was used to compare the volume with the product of the pleural effusion diameters (l × h × d): V = 0.56 × (l × h × d) + 39.44 (r = 0.92, P = 0.000). The 64-slice CT volume-rendering technique can

  4. The preliminary exploration of 64-slice volume computed tomography in the accurate measurement of pleural effusion

    International Nuclear Information System (INIS)

    Guo, Zhi-Jun; Lin, Qiang; Liu, Hai-Tao

    2013-01-01

    Background: Using computed tomography (CT) to rapidly and accurately quantify pleural effusion volume benefits medical and scientific research. However, the precise volume of pleural effusions still involves many challenges and currently does not have a recognized accurate measuring. Purpose: To explore the feasibility of using 64-slice CT volume-rendering technology to accurately measure pleural fluid volume and to then analyze the correlation between the volume of the free pleural effusion and the different diameters of the pleural effusion. Material and Methods: The 64-slice CT volume-rendering technique was used to measure and analyze three parts. First, the fluid volume of a self-made thoracic model was measured and compared with the actual injected volume. Second, the pleural effusion volume was measured before and after pleural fluid drainage in 25 patients, and the volume reduction was compared with the actual volume of the liquid extract. Finally, the free pleural effusion volume was measured in 26 patients to analyze the correlation between it and the diameter of the effusion, which was then used to calculate the regression equation. Results: After using the 64-slice CT volume-rendering technique to measure the fluid volume of the self-made thoracic model, the results were compared with the actual injection volume. No significant differences were found, P = 0.836. For the 25 patients with drained pleural effusions, the comparison of the reduction volume with the actual volume of the liquid extract revealed no significant differences, P = 0.989. The following linear regression equation was used to compare the pleural effusion volume (V) (measured by the CT volume-rendering technique) with the pleural effusion greatest depth (d): V = 158.16 X d - 116.01 (r = 0.91, P = 0.000). The following linear regression was used to compare the volume with the product of the pleural effusion diameters (l X h X d): V = 0.56 X (l X h X d) + 39.44 (r = 0.92, P = 0

  5. The preliminary exploration of 64-slice volume computed tomography in the accurate measurement of pleural effusion

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Zhi-Jun [Dept. of Radiology, North China Petroleum Bureau General Hospital, Renqiu, Hebei (China)], e-mail: Gzj3@163.com; Lin, Qiang [Dept. of Oncology, North China Petroleum Bureau General Hospital, Renqiu, Hebei (China); Liu, Hai-Tao [Dept. of General Surgery, North China Petroleum Bureau General Hospital, Renqiu, Hebei (China)] [and others])

    2013-09-15

    Background: Using computed tomography (CT) to rapidly and accurately quantify pleural effusion volume benefits medical and scientific research. However, the precise volume of pleural effusions still involves many challenges and currently does not have a recognized accurate measuring. Purpose: To explore the feasibility of using 64-slice CT volume-rendering technology to accurately measure pleural fluid volume and to then analyze the correlation between the volume of the free pleural effusion and the different diameters of the pleural effusion. Material and Methods: The 64-slice CT volume-rendering technique was used to measure and analyze three parts. First, the fluid volume of a self-made thoracic model was measured and compared with the actual injected volume. Second, the pleural effusion volume was measured before and after pleural fluid drainage in 25 patients, and the volume reduction was compared with the actual volume of the liquid extract. Finally, the free pleural effusion volume was measured in 26 patients to analyze the correlation between it and the diameter of the effusion, which was then used to calculate the regression equation. Results: After using the 64-slice CT volume-rendering technique to measure the fluid volume of the self-made thoracic model, the results were compared with the actual injection volume. No significant differences were found, P = 0.836. For the 25 patients with drained pleural effusions, the comparison of the reduction volume with the actual volume of the liquid extract revealed no significant differences, P = 0.989. The following linear regression equation was used to compare the pleural effusion volume (V) (measured by the CT volume-rendering technique) with the pleural effusion greatest depth (d): V = 158.16 X d - 116.01 (r = 0.91, P = 0.000). The following linear regression was used to compare the volume with the product of the pleural effusion diameters (l X h X d): V = 0.56 X (l X h X d) + 39.44 (r = 0.92, P = 0

  6. Coronary ostial involvement in acute aortic dissection: detection with 64-slice cardiac CT.

    LENUS (Irish Health Repository)

    Ryan, E Ronan

    2012-02-01

    A 41-year-old man collapsed after lifting weights at a gym. Following admission to the emergency department, a 64-slice cardiac computed tomography (CT) revealed a Stanford Type A aortic dissection arising from a previous coarctation repair. Multiphasic reconstructions demonstrated an unstable, highly mobile aortic dissection flap that extended proximally to involve the right coronary artery ostium. Our case is an example of the application of electrocardiogram-gated cardiac CT in directly visualizing involvement of the coronary ostia in acute aortic dissection, which may influence surgical management.

  7. Diagnostic performance of 64-slice multidetector coronary computed tomographic angiography in women.

    Science.gov (United States)

    Jug, Borut; Gupta, Mohit; Papazian, Jenny; Li, Dong; Tsang, Janet; Bhatia, Harpreet; Karlsberg, Ronald; Budoff, Matthew

    2012-12-01

    Diagnostic approach to chest pain in women is challenging, but still under-investigated. The purpose of this study was to assess the diagnostic performance of 64-slice multidetector coronary computed tomographic angiography (CCTA) in women with chest pain. We included 606 patients--255 women and 351 men (mean age 61 ± 12 years for both)--who had been referred for a CCTA and an invasive coronary angiography (diagnostic standard) because of chest pain, either as part of clinical work-up in two urban medical centers or as part of the multicenter ACCURACY trial. On a patient-based model, the sensitivity, specificity, and positive predictive value (PPV) and negative predictive value to detect ≥50% and ≥70% stenosis were 98%, 84%, 87%, and 97% and 96%, 83%, 77%, and 97%, respectively, for women and 97%, 83%, 89%, and 95% and 94%, 91%, 90%, and 94%, respectively, for men. There were no statistically significant differences between men and women in diagnostic performance measures except for the PPV of detecting a ≥70% stenosis (P = .007). In women with chest pain, 64-slice multidetector CCTA is at least as sensitive and specific as in men. Our findings suggest that CCTA is a promising diagnostic tool for timely detection and/or exclusion of CAD in symptomatic intermediate-risk female populations.

  8. Assessment of maximal myocardial perfusion by ECG-triggered digital subtraction angiography

    Energy Technology Data Exchange (ETDEWEB)

    Pijls, N.H.J.; Uijen, G.J.H.; Werf, T. van der (Katholieke Univ. Nijmegen (Netherlands). Cardiology Dept.)

    1991-01-01

    Early studies about calculation of coronary blood flow by analysis of contrast agent passage on the coronary arteriogram were reported more than 2 decades ago by Rutishauser et al. and Smith et al. Thereafter is was shown that visualization of contrast passage through the myocardium could be enhanced by ECG-triggered digital subtraction imaging and it was suggested that myocardial flow could be calculated by studying the temporal changes in contrast intensity in a myocardial region of interest (ROI) as a function of time: the time density curve (TDC). (orig./GDG).

  9. 64-slice multidetector coronary CT angiography: in vitro evaluation of 68 different stents

    International Nuclear Information System (INIS)

    Maintz, David; Seifarth, Harald; Rink, Michael; Oezguen, Murat; Heindel, Walter; Fischbach, Roman; Raupach, Rainer; Flohr, Thomas; Sommer, Torsten

    2006-01-01

    The purpose of this study was to test a large sample of different coronary artery stents using four image reconstruction approaches with respect to lumen visualization, lumen attenuation, and image noise in 64-slice multidetector-row computed tomography (MDCT) in vitro and to provide a catalogue of currently used coronary artery stents when imaged with state-of the-art MDCT. We examined 68 different coronary artery stents (57 stainless steel, four cobalt-chromium, one cobalt-alloy, two nitinol, four tantalum) in a coronary artery phantom (vessel diameter 3 mm, intravascular attenuation 250 HU, extravascular density -70). Stents were imaged in axial orientation with standard parameters: 32x0.6 collimation, pitch 0.24, 680 mAs, 120 kV, rotation time 0.37 s. Four different image reconstructions were obtained with varying convolution kernels and section thicknesses: (1) soft, 0.6 mm, (2) soft, 0.75, (3) medium soft, 0.6, and (4) stent-optimized sharp, 0.6. To evaluate visualization characteristics of of the stent, the lumen diameter, intraluminal density and noise were measured. The high-resolution kernel offered significantly better average lumen visualization (57% ±10%) and more realistic lumen attenuation (222 HU ±66 HU) at the expense of increased noise (15.3 HU ±3.7 HU) compared with the soft and medium-soft CT angiography (CTA) protocol (p<0.001 for all). Stents with a lumen visibility of more than 66% were: Arthos pico, Driver, Flex, Nexus2, S7, Tenax complete, Vision (all 67%), Symbiot, Teneo (70%), and Radius (73%). Only ten stents showed a lumen visibility of less than 50%. Stent lumen visibility largely varies depending on the stent type. Even with the improved spatial resolution of 64-slice CT, a stent-optimized kernel remains beneficial for stent visualization when compared with the standard medium-soft CTA protocol. Using 64-slice CT and high-resolution kernel, the majority of stent products show a lumen visibility of more than 50% of the stent

  10. Quantitative parameters of image quality in 64-slice computed tomography angiography of the coronary arteries

    International Nuclear Information System (INIS)

    Ferencik, Maros; Nomura, Cesar H.; Maurovich-Horvat, Pal; Hoffmann, Udo; Pena, Antonio J.; Cury, Ricardo C.; Abbara, Suhny; Nieman, Koen; Fatima, Umaima; Achenbach, Stephan; Brady, Thomas J.

    2006-01-01

    We explored quantitative parameters of image quality in consecutive patients undergoing 64-slice multi-detector computed tomography (MDCT) coronary angiography for clinical reasons. Forty-two patients (36 men, mean age 61 ± 11 years, mean heart rate 63 ± 10 bpm) underwent contrast-enhanced MDCT coronary angiography with a 64-slice scanner (Siemens Sensation 64, 64 mmx 0.6 mm collimation, 330 ms tube rotation, 850 mAs, 120 kV). Two independent observers measured the overall visualized vessel length and the length of the coronary arteries visualized without motion artifacts in curved multiplanar reformatted images. Contrast-to-noise ratio was measured in the proximal and distal segments of the coronary arteries. The mean length of visualized coronary arteries was: left main 12 ± 6 mm, left anterior descending 149 ± 25 mm, left circumflex 89 ± 30 mm, and right coronary artery 161 ± 38 mm. On average, 97 ± 5% of the total visualized vessel length was depicted without motion artifacts (left main 100 ± 0%, left anterior descending 97 ± 6%, left circumflex 98 ± 5%, and right coronary artery 95 ± 6%). In 27 patients with a heart rate ≤65 bpm, 98 ± 4% of the overall visualized vessel length was imaged without motion artifacts, whereas 96 ± 6% of the overall visualized vessel length was imaged without motion artifacts in 15 patients with a heart rate >65 bpm (p < 0.001). The mean contrast-to-noise ratio in all measured coronary arteries was 14.6 ± 4.7 (proximal coronary segments: range 15.1 ± 4.4 to 16.1 ± 5.0, distal coronary segments: range 11.4 ± 4.2 to 15.9 ± 4.9). In conclusion, 64-slice MDCT permits reliable visualization of the coronary arteries with minimal motion artifacts and high CNR in consecutive patients referred for non-invasive MDCT coronary angiography. Low heart rate is an important prerequisite for excellent image quality

  11. Clinical value of 64-slice spiral CT for classification of femoral neck fracture

    International Nuclear Information System (INIS)

    Zhu Jiangtao; Gong Jianping; Cai Wu; Zhu Jianbing; Chen Guangqiang; Qian Minghui

    2011-01-01

    Objective: To evaluate the clinical application of 64-slice spiral CT for classification of femoral neck fracture. Methods: The survey was comprised of 46 patients with femoral neck fractures detected with plain radiographs and CT images. Cases were randomly presented in 2 formats: plain radiographs and CT. Garden classification was queried. Modification of garden classification (nondisplaced vs displaced) was taken to compare with plain radiographs and CT in the study. Results: The results of classification for plain radiographs were 2 cases of Garden Ⅰ, 10 cases of Ⅱ, 22 cases of Ⅲ, and 12 cases of Ⅳ. Those for CT were 1 cases of Garden Ⅰ, 4 cases of Ⅱ, 26 cases of Ⅲ, and 15 cases of Ⅳ. CT improved the accuracy of Garden Classification (P<0.05). Conclusion: Garden classification using CT images shows good conformation with results of surgery. 64-Slic CT is better plain radiographs for Garden classification of femoral neck fracture. (authors)

  12. Coronary artery imaging with 64-slice spiral CT in atrial fibrillation patients: initial experience

    International Nuclear Information System (INIS)

    Zhou Xuhui; Yan Chaogui; Xie Hongbo; Li Xiangmin; Li Ziping; Meng Quanfei; Chen Xing

    2008-01-01

    Objective: To discuss the clinical value of coronary artery imaging using 64-slice spiral CT in patient with atrial fibrillation. Methods: The images of 31 patients with atrial fibrillation who underwent contrast-enhanced CT coronary angiography were evaluated. The presence of stenosis on each segment of coronary arteries was recorded and their degree of stenosis was measured using the vessel analysis software. Ten patients additionally underwent conventional coronary angiography. The results of conventional coronary angiography were compared with CT coronary angiography of the 10 patients. Results: Image reconstruction was based on absolute timing. The image quality of 364 coronary vessel segments on the images from 31 patients was evaluated and defined as excellent, fine, moderate or poor. The image quality was excellent, fine, moderate and poor in 85, 41, 5, and 8 vessel segments respectively in patient group with heart rate between 47 beat per minent (bpm) and 69 bpm; and in 63, 16, 13, and 15 vessel segments respectively in patent group with heart rate between 70 bpm and 79 bpm;and in 46, 25, 23, and 24 vessel segments in patient group with heart rate between 80 bpm and 105 bpm. There was significant difference among the three patient groups (H=22.08, P<0.01). Comparison was carried out between CT angiographic findings and conventional angiographic findings of the 125 segments of the coronary arteries in the 10 patients who underwent conventional coronary angiography. The sensitivity and specificity of CT angiography for diagnosing vessel with significant coronary stenosis (≥50% narrowing) was 85.0% (17/20) and 95.2% (100/105), respectively. Positive predictive value was 77.3% (17/22), and negative predictive value was 97.1% (100/103). Coronary CTA underestimated the lesions of 3 vessel segments and overestimated the lesions of 5 vessel segments. Conclusion: Coronary artery imaging with 64-slice row CT had clinical value for patients with atrial fibrillation

  13. Calculation of the Scattered Radiation Profile in 64 Slice CT Scanners Using Experimental Measurement

    Directory of Open Access Journals (Sweden)

    Afshin Akbarzadeh

    2009-06-01

    Full Text Available Introduction: One of the most important parameters in x-ray CT imaging is the noise induced by detected scattered radiation. The detected scattered radiation is completely dependent on the scanner geometry as well as size, shape and material of the scanned object. The magnitude and spatial distribution of the scattered radiation in x-ray CT should be quantified for development of robust scatter correction techniques. Empirical methods based on blocking the primary photons in a small region are not able to extract scatter in all elements of the detector array while the scatter profile is required for a scatter correction procedure. In this study, we measured scatter profiles in 64 slice CT scanners using a new experimental measurement. Material and Methods: To measure the scatter profile, a lead block array was inserted under the collimator and the phantom was exposed at the isocenter. The raw data file, which contained detector array readouts, was transferred to a PC and was read using a dedicated GUI running under MatLab 7.5. The scatter profile was extracted by interpolating the shadowed area. Results: The scatter and SPR profiles were measured. Increasing the tube voltage from 80 to 140 kVp resulted in an 80% fall off in SPR for a water phantom (d=210 mm and 86% for a polypropylene phantom (d = 350 mm. Increasing the air gap to 20.9 cm caused a 30% decrease in SPR. Conclusion: In this study, we presented a novel approach for measurement of scattered radiation distribution and SPR in a CT scanner with 64-slice capability using a lead block array. The method can also be used on other multi-slice CT scanners. The proposed technique can accurately estimate scatter profiles. It is relatively straightforward, easy to use, and can be used for any related measurement.

  14. Assessment of extracranial-intracranial bypass patency with 64-slice multidetector computerized tomography angiography

    Energy Technology Data Exchange (ETDEWEB)

    Thines, Laurent [Lille University Hospital, Department of Neurosurgery, Lille (France); Toronto Western Hospital, Division of Neurosurgery and Department of Surgery, Toronto, ON (Canada); Toronto Western Hospital, University of Toronto Brain Vascular Malformation Study Group, Toronto, ON (Canada); Agid, Ronit; Da Costa, Leodante; Terbrugge, Karel G. [Toronto Western Hospital, Division of Neuroradiology, Department of Medical Imaging, Toronto, ON (Canada); Toronto Western Hospital, University of Toronto Brain Vascular Malformation Study Group, Toronto, ON (Canada); Dehdashti, Amir R.; Wallace, M.C.; Tymianski, Michael [Toronto Western Hospital, Division of Neurosurgery and Department of Surgery, Toronto, ON (Canada); Toronto Western Hospital, University of Toronto Brain Vascular Malformation Study Group, Toronto, ON (Canada)

    2009-08-15

    Extracranial-intracranial (EC/IC) bypass is a useful procedure for the treatment of cerebral vascular insufficiency or complex aneurysms. We explored the role of multidetector computed tomography angiography (MDCTA), instead of digital subtraction angiography (DSA), for the postoperative assessment of EC/IC bypass patency. We retrospectively analyzed a consecutive series of 21 MDCTAs from 17 patients that underwent 25 direct or indirect EC/IC bypass procedures between April 2003 and November 2007. Conventional DSA was available for comparison in 13 cases. MDCTA used a 64-slice MDCT scanner (Aquilion 64, Toshiba). The proximal and distal patencies were analyzed independently on MDCTA and DSA by a neuroradiologist and a neurosurgeon. The bypass was considered patent when the entire donor vessel was opacified without discontinuity from proximal to distal ends and was visibly in contact with the recipient vessel. MDCTA depicted the patency status in every patient. Bypasses were patent in 22 cases, stenosed in one, and occluded in two. DSA always confirmed the results of the MDCTA (sensitivity = 100%, 95% CI = 0.655-1.0; specificity 100%, 95% CI = 0.05-1.0). MDCTA is a non-invasive and accurate exam to assess the postoperative EC/IC bypass patency and is a promising technique in routine follow-up. (orig.)

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

    International Nuclear Information System (INIS)

    Kim, Eun Young; Kang, Doo Kyoung; Sun, Joo Sung; Choi, So Yeon

    2013-01-01

    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 3 , 90.4%) than in calcified plaque (median, 0.7 mm 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.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-12-15

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

  17. Analysis of hepatic vein variations in healthy people with 64-slice spiral CT

    International Nuclear Information System (INIS)

    Zhang Rong; Li Yong; Shen Jun; Zeng Weike; Li Jieting; Huang Suiqiao; Liang Biling; Liu Chao

    2007-01-01

    Objective: To analyze variations of hepatic vein in healthy people with 64-slice spiral CT. Methods: Seventy-five healthy subjects underwent multi-slice spiral computed (MSCT) hepatic venography. The anatomy of the junction of the hepatic veins with the inferior vena cava and the intrahepatic drainage territory of the hepatic veins and tributaries were evaluated. The hepatic veins were classified according to three anatomic classification (Nakamura's, Marcos's and Kawasaki's classification) methods respectively. Results: There was a common trunk of the middle and left hepatic veins before joining the IVC in 86.7% (65/75)of the cases. In 13.3% (10/75)of the cases, the three main hepatic veins joined the IVC separately. The ratios of Nakamma's classification type A, B, C of hepatic veins were 49.4% (37/75), 37.3% (28/75), and 13.3% (10/75) respectively. The ratios of Marcos's classification type A, B, C of hepatic veins were 56.0% (42/75), 24.0% (18/75), and 20.0% (15/75) respectively. The ratios of Kawasaki's classification type I, II of hepatic vein were 40.0% (30/75) and 60.0% (45/75). Conclusion: Multi-slice spiral CT hepatic venography can provide visualization of peripheral hepatic venous branches in details. (authors)

  18. Coronary 64-slice CT angiography predicts outcome in patients with known or suspected coronary artery disease

    Energy Technology Data Exchange (ETDEWEB)

    Gaemperli, Oliver; Valenta, Ines; Schepis, Tiziano [University Hospital Zurich NUK C 32, Cardiovascular Center, Zurich (Switzerland); Husmann, Lars; Scheffel, Hans; Desbiolles, Lotus; Leschka, Sebastian; Alkadhi, Hatem [University Hospital Zurich, Institute of Diagnostic Radiology, Zurich (Switzerland); Kaufmann, Philipp A. [University Hospital Zurich NUK C 32, Cardiovascular Center, Zurich (Switzerland); University of Zurich, Zurich Center for Integrative Human Physiology (ZIHP), Zurich (Switzerland)

    2008-06-15

    The aim of this study was to assess the prognostic value of 64-slice CT angiography (CTA) in patients with known or suspected coronary artery disease (CAD). Sixty-four-slice coronary CTA was performed in 220 patients [mean age 63 {+-} 11 years, 77 (35%) female] with known or suspected CAD. CTA images were analyzed with regard to the presence and number of coronary lesions. Patients were followed-up for the occurrence of the following clinical endpoints: death, nonfatal myocardial infarction, unstable angina, and coronary revascularization. During a mean follow-up of 14 {+-} 4 months, 59 patients (27%) reached at least one of the predefined clinical endpoints. Patients with abnormal coronary arteries on CTA (i.e., presence of coronary plaques) had a 1st-year event rate of 34%, whereas in patients with normal coronary arteries no events occurred (event rate, 0%, p < 0.001). Similarly, obstructive lesions ({>=}50% luminal narrowing) on CTA were associated with a high first-year event rate (59%) compared to patients without stenoses (3%, p < 0.001). The presence of obstructive lesions was a significant independent predictor of an adverse cardiac outcome. Sixty-four-slice CTA predicts cardiac events in patients with known or suspected CAD. Conversely, patients with normal coronary arteries on CTA have an excellent mid-term prognosis. (orig.)

  19. Congenital Left Circumflex Coronary Artery Atresia Detected by 64-Slice Computed Tomography: A Case Report

    Directory of Open Access Journals (Sweden)

    Chen-Yuan Liu

    2007-06-01

    Full Text Available A variety of coronary artery disorders, including intramyocardial coronary segments and coronary artery anomalies, can result in sudden cardiac death, especially in young adults. The detection of structural coronary artery abnormalities is important in the management of patients at risk of sudden cardiac death. Coronary artery anomalies occur in about 1% of the population. Congenital absence of left circumflex coronary artery (LCX is a very rare vascular anomaly, and few cases have been reported in the literature, with a frequency of only 0.003% in all patients who underwent coronary angiography. Although coronary catheterization is the gold standard for the evaluation of coronary arterial patency disease, noninvasive computed tomography (CT is considered the diagnostic method of choice for the detection and evaluation of coronary artery anomaly. Herein, we report the case of a 17-year-old girl who presented with exertional dyspnea and chest pain and who was studied at our emergency department with the final diagnosis of LCX atresia detected by 64-slice CT. She may be the first case of congenital LCX atresia proved by multislice CT.

  20. In vitro imaging of coronary artery stents: Are there differences between 16- and 64-slice CT scanners?

    International Nuclear Information System (INIS)

    Wolf, Florian; Feuchtner, Gudrun M.; Homolka, Peter; Langenberger, Herbert; Stadler, Alfred; Bader, Till R.; Weber, Michael; Lammer, Johannes; Loewe, Christian

    2008-01-01

    Purpose: To compare the performance of 64-slice with 16-slice CT scanners for the in vitro evaluation of coronary artery stents. Methods and materials: Twelve different coronary artery stents were placed in the drillings of a combined heart and chest phantom, which was scanned with a 16- and 64-slice CT scanner. Coronal reformations were evaluated for artificial lumen narrowing, intraluminal attenuation values, and false widening of the outer stent diameter as an indicator of artifacts outside the stent. Results: Mean artificial lumen narrowing was not significantly different between the 16- and 64-slice CT scanner (44% versus 39%; p = 0.408). The differences between the Hounsfield Units (HU) measurements inside and outside the stents were significantly lower (p = 0.001) with 64- compared to 16-slice CT. The standard deviation of the HU measurements inside the stents was significantly (p = 0.002) lower with 64- than with 16-slice CT. Artifacts outside the stents were not significantly different between the scanners (p = 0.866). Conclusion: Visualization of the in-stent lumen is improved with 64-slice CT when compared with 16-slice CT as quantified by significantly lesser intraluminal image noise and less artificial rise in intraluminal HU measurement, which is the most important parameter for the evaluation of stent patency in vivo

  1. Ditection of coronary artery disease: accuracy of 64- slice computed tomography versus converntional invasive angiography

    Directory of Open Access Journals (Sweden)

    Taghizadeh M

    2008-11-01

    Full Text Available "nBackground: Multislice computed tomography (MSCT is a noninvasive method of detecting coronary artery disease (CAD. The purpose of the present study was to investigate the accuracy of 64-slice MSCT (64-MSCT in daily practice, without patient selection. "nMethods: Sixty-four consecutive suspected CAD patients underwent both 64-MSCT and quantitative coronary angiography (QCA. The CT system The mean time span between MSCT and QCA was 7.2±3.9 days. For the 64-MSCT, detection or exclusion of CAD, defined as one or more areas of >50% stenosis within major epicardial coronary arteries, the sensitivity, specificity, diagnostic accuracy, positive predictive value (PPV, and negative predictive value (NPV were evaluated both per patient and per segment. "nResults: Sixty-one of the 64 coronary CT angiograms (95% were of diagnostic image quality. QCA showed significant CAD in 64% (39/61 of the patients, with the other 36% (22/61 showing nonsignificant disease or no disease. Sensitivity, specificity, accuracy, PPV, and NPV of 64-MSCT per patient were 92%, 86%, 90%, 92% and 96%, respectively. By the per-segment analysis, 695 of 791 coronary artery segments were assessable (88%. Of these, 64-MSCT showed a sensitivity of 80%, specificity of 92%, accuracy of 90%, PPV of 65%, and NPV of 96%, respectively, in detecting CAD. "nConclusions: Both per patient and per segment analyses for coronary 64-MSCT showed a higher diagnostic accuracy than QCA. This suggests 64-MSCT should primarily be used for risk stratification on a per patient basis as a noninvasive gate-keeper diagnostic method.

  2. Radiation dose and cancer risk from pediatric CT examinations on 64-slice CT: A phantom study

    International Nuclear Information System (INIS)

    Feng Shiting; Law, Martin Wai-Ming; Huang Bingsheng; Ng, Sherry; Li Ziping; Meng Quanfei; Khong, Pek-Lan

    2010-01-01

    Objective: To measure the radiation dose from CT scans in an anthropomorphic phantom using a 64-slice MDCT, and to estimate the associated cancer risk. Materials and methods: Organ doses were measured with a 5-year-old phantom and thermoluminescent dosimeters. Four protocols; head CT, thorax CT, abdomen CT and pelvis CT were studied. Cancer risks, in the form of lifetime attributable risk (LAR) of cancer incidence, were estimated by linear extrapolation using the organ radiation doses and the LAR data. Results: The effective doses for head, thorax, abdomen and pelvis CT, were 0.7 mSv, 3.5 mSv, 3.0 mSv, 1.3 mSv respectively. The organs with the highest dose were; for head CT, salivary gland (22.33 mGy); for thorax CT, breast (7.89 mGy); for abdomen CT, colon (6.62 mGy); for pelvis CT, bladder (4.28 mGy). The corresponding LARs for boys and girls were 0.015-0.053% and 0.034-0.155% respectively. The organs with highest LARs were; for head CT, thyroid gland (0.003% for boys, 0.015% for girls); for thorax CT, lung for boys (0.014%) and breast for girls (0.069%); for abdomen CT, colon for boys (0.017%) and lung for girls (0.016%); for pelvis CT, bladder for both boys and girls (0.008%). Conclusion: The effective doses from these common pediatric CT examinations ranged from 0.7 mSv to 3.5 mSv and the associated lifetime cancer risks were found to be up to 0.16%, with some organs of higher radiosensitivity including breast, thyroid gland, colon and lungs.

  3. Accessory left atrial diverticulae: contractile properties depicted with 64-slice cine-cardiac CT.

    LENUS (Irish Health Repository)

    Killeen, Ronan P

    2012-02-01

    To assess the contractility of accessory left atrial appendages (LAAs) using multiphasic cardiac CT. We retrospectively analyzed the presence, location, size and contractile properties of accessory LAAs using multiphasic cardiac 64-slice CT in 102 consecutive patients (63 males, 39 females, mean age 57). Multiplanar reformats were used to create image planes in axial oblique, sagittal oblique and coronal oblique planes. For all appendages with an orifice diameter >or= 10 mm, axial and sagittal diameters and appendage volumes were recorded in atrial diastole and systole. Regression analysis was performed to assess which imaging appearances best predicted accessory appendage contractility. Twenty-three (23%) patients demonstrated an accessory LAA, all identified along the anterior LA wall. Dimensions for axial oblique (AOD) and sagittal oblique (SOD) diameters and sagittal oblique length (SOL) were 6.3-19, 3.4-20 and 5-21 mm, respectively. All appendages (>or=10 mm) demonstrated significant contraction during atrial systole (greatest diameter reduction was AOD [3.8 mm, 27%]). Significant correlations were noted between AOD-contraction and AOD (R = 0.57, P < 0.05) and SOD-contraction and AOD, SOD and SOL (R = 0.6, P < 0.05). Mean diverticulum volume in atrial diastole was 468.4 +\\/- 493 mm(3) and in systole was 171.2 +\\/- 122 mm(3), indicating a mean change in volume of 297.2 +\\/- 390 mm(3), P < 0.0001. Stepwise multiple regression analysis revealed SOL to be the strongest independent predictor of appendage contractility (R(2) = 0.86, P < 0.0001) followed by SOD (R(2) = 0.91, P < 0.0001). Accessory LAAs show significant contractile properties on cardiac CT. Those accessory LAAs with a large sagittal height or depth should be evaluated for contractile properties, and if present should be examined for ectopic activity during electrophysiological studies.

  4. Evaluation of temporal windows for coronary artery bypass graft imaging with 64-slice CT

    International Nuclear Information System (INIS)

    Desbiolles, Lotus; Leschka, Sebastian; Scheffel, Hans; Husmann, Lars; Garzoli, Elisabeth; Marincek, Borut; Alkadhi, Hatem; Plass, Andre; Gaemperli, Oliver; Kaufmann, Philipp A.

    2007-01-01

    Temporal windows providing the best image quality of different segments and types of coronary artery bypass grafts (CABGs) with 64-slice computed tomography (CT) were evaluated in an experimental set-up. Sixty-four-slice CT with a rotation time of 330 ms was performed in 25 patients (four female; mean age 59.9 years). A total of 84 CABGs (62 individual and 22 sequential grafts) were evaluated, including 28 internal mammary artery (33.3%), one radial artery with sequential grafting (2.4%), and 54 saphenous vein grafts (64.3%). Ten data sets were reconstructed in 10% increments of the RR-interval. Each graft was separated into segments (proximal and distal anastomosis, and body), and CABG types were grouped according to target arteries. Two readers independently assessed image quality of each CABG segment in each temporal window. Diagnostic image quality was found with good inter-observer agreement (kappa=0.62) in 98.5% (202/205) of all graft segments. Image quality was significantly better for saphenous vein grafts versus arterial grafts (P<0.001) and for distal anastomosis to the right coronary compared with other target coronary arteries (P<0.05). Overall, best image quality was found at 60%. Image quality of proximal segments did not significantly vary with the temporal window, whereas for all other segments image quality was significantly better at 60% compared with other temporal windows (P<0.05). Sixty-four-slice CT provides best image quality of various segments and types of CABG at 60% of the RR-interval. (orig.)

  5. In vitro measurement of CT density and estimation of stenosis related to coronary soft plaque at 100 kV and 120 kV on ECG-triggered scan

    Energy Technology Data Exchange (ETDEWEB)

    Horiguchi, Jun, E-mail: horiguch@hiroshima-u.ac.jp [Department of Clinical Radiology, Hiroshima University Hospital, 1-2-3, Kasumi-cho, Minami-ku, Hiroshima 734-8551 (Japan); Fujioka, Chikako, E-mail: fujioka@hiroshima-u.ac.jp [Department of Clinical Radiology, Hiroshima University Hospital, 1-2-3, Kasumi-cho, Minami-ku, Hiroshima 734-8551 (Japan); Kiguchi, Masao, E-mail: kiguchi@hiroshima-u.ac.jp [Department of Clinical Radiology, Hiroshima University Hospital, 1-2-3, Kasumi-cho, Minami-ku, Hiroshima 734-8551 (Japan); Yamamoto, Hideya, E-mail: hideyayama@hiroshima-u.ac.jp [Department of Cardiovascular Medicine, Hiroshima University Graduate School of Biomedical Sciences and Hiroshima University Hospital, 1-2-3, Kasumi-cho, Minami-ku, Hiroshima 734-8551 (Japan); Shen, Yun, E-mail: Yuna.Shen@ge.com [CT Lab of Great China, GE Healthcare, L12 and L15, Office Tower, Langham Place, 8 Argyle Street, Mongkok Kowloon (Hong Kong); Kihara, Yasuki, E-mail: ykihara@hiroshima-u.ac.jp [Department of Cardiovascular Medicine, Hiroshima University Graduate School of Biomedical Sciences and Hiroshima University Hospital, 1-2-3, Kasumi-cho, Minami-ku, Hiroshima 734-8551 (Japan)

    2011-02-15

    Purpose: The purpose of the study was to compare 100 kV and 120 kV prospective electrocardiograph (ECG)-triggered axial coronary 64-detector CT angiography (64-MDCTA) in soft plaque diagnosis. Materials and methods: Coronary artery models (n = 5) with artificial soft plaques (-32 HU to 53 HU at 120 kV) with three stenosis levels (25%, 50% and 75%) on a cardiac phantom (mimicking slim patient's environment) were scanned in heart rates of 55, 60 and 65 beats per minute (bpm). Four kinds of intracoronary enhancement (205 HU, 241 HU, 280 HU and 314 HU) were simulated. The soft plaque density and the measurement error of stenosis (in percentage), evaluated by two independent observers, were compared between 100 kV and 120 kV. The radiation dose was estimated. Results: Interobserver correlation of the measurement was excellent (density; r = 0.95 and stenosis measure; r = 0.97). Neither the density of soft plaque nor the measurement error of stenosis was different between 100 kV and 120 kV (p = 0.22 and 0.08). The estimated radiation doses were 2.0 mSv and 3.3 mSv (in 14 cm coverage) on 100 kV and 120 kV prospective ECG-triggered axial scans, respectively. Conclusion: The 100 kV prospective ECG-triggered coronary MDCTA has comparable performance to 120 kV coronary CTA in terms of soft plaque densitometry and measurement of stenosis, with a reduced effective dose of 2 mSv.

  6. Comparative evaluation of 64-slice CT angiography and digital subtraction angiography in assessing the cervicocranial vasculature

    Directory of Open Access Journals (Sweden)

    Randolf Klingebiel

    2008-08-01

    Full Text Available Randolf Klingebiel1, Max Kentenich3, Hans-Christian Bauknecht3, Florian Masuhr2, Eberhard Siebert1, Markus Busch2, Georg Bohner11Department of Neuroradiology, 2Department of Neurology, 3Department of Radiology, Charité Universitary Medicine Berlin, GermanyBackground: Noninvasive 64-slice computed tomography angiography (64-MSCTA closely approximates conventional catheter angiography (DSA in terms of detail resolution. Objective: Retrospective evaluation of cervicocranial (cc 64-MSCTA in comparison with DSA in patients with presumptive cc vascular disorders.Material and methods: Twenty-four 64-MSCTA studies (32 mm detector width, slice thickness 0.5 mm, 120 kv, 150 mAs, pitch 0.75 of patients with presumptive cc vascular pathology (13 men, 11 women, mean age 38.3 ± 11.3 yrs, range 19–54 yrs were assessed in comparison with DSA studies without abnormal findings in age-matched patients (11 men, 13 women, mean age 39.7 ± 11.9 yrs, range 18–54 yrs. Study readings were performed in a blinded manner by two neuroradiologists with respect to image quality and assessibility of various cc vascular segments by using a five-point scale. Radiation exposure was calculated for 64-MSCTA.Results: Each reader assessed 384/528 different vessel segments (64-MSCTA/DSA. Superior image quality was attributed to DSA with respect to the C1 ICA–C6 ICA, A3 ACA, and P3 PCA segments as well the AICA and SCA. 64-MSCTA was scored superior for C7 ICA and V4 VA segments. A significantly increased number of nonassessable V2- and V3 VA segments in DSA studies was noted. The effective dose for 64-MSCTA amounted to 2.2 mSv.Conclusions: 64-MSCTA provides near-equivalent diagnostic information of the cc vasculature as compared with DSA. According to our results, DSA should be considered primarily when peripheral vessels (A3/P3 or ICA segments close to the skull base (C2-5 are of interest, such as in primary angiitis or stenoocclusive ICA disease, respectively.Keywords: CT

  7. Performance evaluation of a 64-slice CT system with z-flying focal spot.

    Science.gov (United States)

    Flohr, T; Stierstorfer, K; Raupach, R; Ulzheimer, S; Bruder, H

    2004-12-01

    The meanwhile established generation of 16-slice CT systems enables routine sub-millimeter imaging at short breath-hold times. Clinical progress in the development of multidetector row CT (MDCT) technology beyond 16 slices can more likely be expected from further improvement in spatial and temporal resolution rather than from a mere increase in the speed of volume coverage. We present an evaluation of a recently introduced 64-slice CT system (SOMATOM Sensation 64, Siemens AG, Forchheim, Germany), which uses a periodic motion of the focal spot in longitudinal direction (z-flying focal spot) to double the number of simultaneously acquired slices. This technique acquires 64 overlapping 0.6 mm slices per rotation. The sampling scheme corresponds to that of a 64 x 0.3 mm detector, with the goal of improved longitudinal resolution and reduced spiral artifacts. After an introduction to the detector design, we discuss the basics of z-flying focal spot technology (z-Sharp). We present phantom and specimen scans for performance evaluation. The measured full width at half maximum (FWHM) of the thinnest spiral slice is 0.65 mm. All spiral slice widths are almost independent of the pitch, with deviations of less than 0.1 mm from the nominal value. Using a high-resolution bar pattern phantom (CATPHAN, Phantom Laboratories, Salem, NY), the longitudinal resolution can be demonstrated to be up to 15 lp/cm at the isocenter independent of the pitch, corresponding to a bar diameter of 0.33 mm. Longitudinal resolution is only slightly degraded for off-center locations. At a distance of 100 mm from the isocenter, 14 lp/cm can be resolved in the z-direction, corresponding to a bar diameter of 0.36 mm. Spiral "windmill" artifacts presenting as hyper- and hypodense structures around osseous edges are effectively reduced by the z-flying focal spot technique. Cardiac scanning benefits from the short gantry rotation time of 0.33 s, providing up to 83 ms temporal resolution with 2-segment ECG

  8. Diagnostic accuracy of non-invasive 64-slice CT coronary angiography in patients with stable angina pectoris

    Energy Technology Data Exchange (ETDEWEB)

    Pugliese, Francesca; Krestin, Gabriel P. [Erasmus Medical Center, Department of Radiology, Rotterdam (Netherlands); Mollet, Nico R.A.; deFeyter, Pim J. [Erasmus Medical Center, Department of Radiology, Rotterdam (Netherlands); Erasmus Medical Center, Department of Cardiology, Rotterdam (Netherlands); Runza, Giuseppe [University of Palermo, Department of Radiology, Palermo (Italy); Azienda Ospedaliera di Parma, Department of Radiology, Parma (Italy); Mieghem, Carlos van; Meijboom, Willem B.; Baks, Timo [Erasmus Medical Center, Department of Cardiology, Rotterdam (Netherlands); Malagutti, Patrizia [Erasmus Medical Center, Department of Cardiology, Rotterdam (Netherlands); University of Ferrara, Department of Cardiology, Ferrara (Italy); Cademartiri, Filippo [Erasmus Medical Center, Department of Radiology, Rotterdam (Netherlands); Azienda Ospedaliera di Parma, Department of Radiology, Parma (Italy)

    2006-03-15

    Multislice computed tomography (CT) is an emerging technique for the non-invasive detection of coronary stenoses. While the diagnostic accuracy of 4-slice scanners was limited, 16-slice CT imagers showed promising results due to increased temporal and spatial resolution. These technical advances prompted us to evaluate the diagnostic performance of 64-slice CT coronary angiography in the detection of significant stenoses (defined as {>=} 50% luminal diameter reduction) versus invasive quantitative coronary angiography (QCA). Thirty-five patients with stable angina pectoris underwent CT coronary angiography performed with a 64-slice scanner (gantry rotation time 330 ms, individual detector width 0.6 mm) prior to conventional coronary angiography. Patients with heart rates >70 beats/min received 100 mg metoprolol orally. One hundred millilitres of contrast agent with an iodine concentration of 400 mgl/ml were injected at a rate of 5 ml/s into the antecubital vein. The CT scan was triggered with the bolus tracking technique. The sensitivity, specificity and the positive and negative predictive values of 64-slice CT were 99%, 96%, 78% and 99%, respectively, on a per-segment basis. The values obtained on a per-patient basis were 100%, 90%, 96% and 100%, respectively. When referral to catheterisation is questionable, CT coronary angiography may identify subjects with normal angiograms and consistently decrease the number of unnecessary invasive procedures. (orig.)

  9. Diagnostic accuracy of non-invasive 64-slice CT coronary angiography in patients with stable angina pectoris

    International Nuclear Information System (INIS)

    Pugliese, Francesca; Krestin, Gabriel P.; Mollet, Nico R.A.; DeFeyter, Pim J.; Runza, Giuseppe; Mieghem, Carlos van; Meijboom, Willem B.; Baks, Timo; Malagutti, Patrizia; Cademartiri, Filippo

    2006-01-01

    Multislice computed tomography (CT) is an emerging technique for the non-invasive detection of coronary stenoses. While the diagnostic accuracy of 4-slice scanners was limited, 16-slice CT imagers showed promising results due to increased temporal and spatial resolution. These technical advances prompted us to evaluate the diagnostic performance of 64-slice CT coronary angiography in the detection of significant stenoses (defined as ≥ 50% luminal diameter reduction) versus invasive quantitative coronary angiography (QCA). Thirty-five patients with stable angina pectoris underwent CT coronary angiography performed with a 64-slice scanner (gantry rotation time 330 ms, individual detector width 0.6 mm) prior to conventional coronary angiography. Patients with heart rates >70 beats/min received 100 mg metoprolol orally. One hundred millilitres of contrast agent with an iodine concentration of 400 mgl/ml were injected at a rate of 5 ml/s into the antecubital vein. The CT scan was triggered with the bolus tracking technique. The sensitivity, specificity and the positive and negative predictive values of 64-slice CT were 99%, 96%, 78% and 99%, respectively, on a per-segment basis. The values obtained on a per-patient basis were 100%, 90%, 96% and 100%, respectively. When referral to catheterisation is questionable, CT coronary angiography may identify subjects with normal angiograms and consistently decrease the number of unnecessary invasive procedures. (orig.)

  10. Optimization of individualized abdominal scan protocol with 64-slice CT scanner

    International Nuclear Information System (INIS)

    Hu Minxia; Zhao Xinming; Song Junfeng; Zhou Chunwu

    2012-01-01

    Objective: To explore an individualized abdominal scan protocol with a 64-slice CT scanner. Methods: From Sep. 2010 to Nov. 2010, one hundred consecutive patients, who underwent twice non-contrast-enhanced abdominal CT scans within 3 months, were enrolled in this study. For each patient, the tube current of 274 eff. mAs and 207 eff. mAs were applied respectively in the first and second abdominal scan. The imaging qualities of the two scans were evaluated retrospectively by 3 reviewers. All the individual variants,including height, weight, body mass index (BMI), the maximum transverse diameter, the anteroposterior diameter and the average maximum diameter of abdomen were recorded. A five-point scale was used for grading the image noise of eight organs, including abdominal aorta, portal vein, liver, spleen, gallbladder, pancreas, renal cortex and renal medulla. Diagnostic acceptability of CT images at three anatomic levels,including porta hepatis, pancreas and the upper pole of renal, was also evaluated by using a five-point scale. The noise value of abdominal aorta was defined as the standard deviation (SD) of CT values of aorta at the level of porta hepatis. Scatter diagram and Pearson correlation analysis were used for evaluating the linear relationship between the individual variants and the noise value of abdominal aorta, and multivariate linear regression analysis was used for evaluating the relevance between the individual variants and the noise value of aorta. Results: In this patients group, the average height was (164.6 ± 7.5) cm,the average weight was (64.3 ± 11.0) kg, the BMI was (23.7 ±3.3) kg/m 2 , the maximum transverse diameter of abdomen was (29.8 ± 2.3) cm, the anteroposterior diameter of abdomen was (23.1 ± 2.9) cm, and the average maximum diameter of abdomen was (26.5 ± 2.5) cm. Pearson correlation analysis showed significant positive linear correlation between the noise value of abdominal aorta (1 1.7 ± 3.0) and patients' weight (r=0

  11. Demonstration of the pulmonary interlobar fissures on multiplanar reformatted images with 64-slices spiral CT

    International Nuclear Information System (INIS)

    Wang Yafei; Chen Yerong; Shan Xiuhong; Tang Zhiyang; Ni Enzhen; Huang Hao; Wu Shuchun

    2009-01-01

    Objective: To determine the optimal orientation and slice thickness of reformatted images to visualize the interlobar fissures on multiplanar reformation (MPR) images and to recommend MPR imaging protocal for visualizing interlobar fissures in clinical practise. Methods: 64-slices CT scans of chest were obtained in 300 patients without pulmonary diseases. Axial, sagittal and coronal images were reformatted at 1, 2, 3, 7 mm slice thickness respectively from the raw volume data. Three experienced radiologists evaluated all of the MPR images in the lung window and compared the differences in visualization of the interlohar fissures among the three reformatted orientations and at the different slice thicknesses with Fisher test and Friedman test. Results: Fissures on sagittal MPR images using 1, 2, 3, and 7 mm reformatted slice thickness appeared as a fine line and the preference value analysis showed the MPR images with a 3 mm reformatted slice thickness is the best for visualizing the interlobar fissure. Compared to the sagittal orientation, the coronal was not as good and the axial was the worst among the three orientations. The coronal images with a 3 mm reformatted slice thickness were slightly inferior to sagittal images. The right horizontal fissures were observed as a fine line in all coronal image in 94.0% (282)of cases and in some of the images in 6.0% (18) of cases, the right oblique fissures were displayed as a fine line in coronal images in 2.3% (7) of cases and in some images in 85.0% (255) of cases, the left oblique fissures were displayed as a fine line in some coronal images in 35.7% (107) of cases and displayed as a coarse line in 64.3% (193) of cases. On axial MPR images using 3 mm reformation slice thickness, the right oblique fissures and the left oblique fissures were displayed as a fine line in some axial images in 79.3% (238) and 81.0% (243) of cases respectively, none of the images showed horizontal fissures as a fine line. There was

  12. Application of triple rule-out with 64-slice spiral CT in the diagnosis of acute chest pain

    International Nuclear Information System (INIS)

    Li Pengyu; Li Kuncheng; Du Xiangyin; Cao Lizhen; Liu Jiabin; Yang Yanhuui; Liang Zhigang; Zhu Xiaolian; Liu Jian

    2007-01-01

    Objective: To investigate the performance of triple rule-out with 64-slice spiral CT in the combined examination of pulmonary artery, thoracic aorta and coronary artery for patients with acute chest pain. Methods: Seventy patients who presented with acute chest pain were included in the study. All of the patients underwent retrospective ECG-gated 64-slice computed tomography triple rule-out examination to evaluate the pulmonary arteries, thoracic aorta and coronary arteries. Multi-planar reconstruction (MPR), maximum intensity projection (MIP), curved-planar reconstruction (CPR) and volume rendering (VR) were used to display pulmonary arteries, thoracic aorta and coronary arteries. We evaluated the image quality of coronary artery and the enhancement of the pulmonary artery and thoracic aorta to estimate if the examination can fulfill the clinical demand for the differential diagnosis of acute chest pain. Results: The mean scan time was (8.5±1.0) s, and the dose of contrast medium injected was 100 ml. There were 95.7% (67/70) of patients whose CT values detected in the pulmonary artery and thoracic aorta after enhancement Were ≥200 HU. The image quality of 85.8% (720/839) coronary segments was classified as excellent, 8.6% (72/839) as good, and 5.6% (47/839) as poor. There were 20 eases with coronary stenoses ≥50%, 2 cases with pulmonary embolism, and 2 cases with aortic dissection. Conclusion: The triple rule-out examination with 64-slice spiral CT could depict pulmonary artery, thoracic aorta, and coronary artery in 8 s with good image quality. It has great potential in the etiological diagnosis for the patients with acute chest pain. (authors)

  13. Assessment of global and regional left ventricular function using 64-slice multislice computed tomography and 2D echocardiography: A comparison with cardiac magnetic resonance

    International Nuclear Information System (INIS)

    Annuar, Bin Rapaee; Liew, Chee Khoon; Chin, Sze Piaw; Ong, Tiong Kiam; Seyfarth, M. Tobias; Chan, Wei Ling; Fong, Yean Yip; Ang, Choon Kiat; Lin, Naing; Liew, Houng Bang; Sim, Kui Hian

    2008-01-01

    Objectives: To compare the assessment of global and regional left ventricular (LV) function using 64-slice multislice computed tomography (MSCT), 2D echocardiography (2DE) and cardiac magnetic resonance (CMR). Methods: Thirty-two consecutive patients (mean age, 56.5 ± 9.7 years) referred for evaluation of coronary artery using 64-slice MSCT also underwent 2DE and CMR within 48 h. The global left ventricular function which include left ventricular ejection fraction (LVEF), left ventricular end diastolic volume (LVdV) and left ventricular end systolic volume (LVsV) were determine using the three modalities. Regional wall motion (RWM) was assessed visually in all three modalities. The CMR served as the gold standard for the comparison between 64-slice MSCT with CMR and 2DE with CMR. Statistical analysis included Pearson correlation coefficient, Bland-Altman plots and κ-statistics. Results: The 64-slice MSCT agreed well with CMR for assessment of LVEF (r = 0.92; p < 0.0001), LVdV (r = 0.98; p < 0.0001) and LVsV (r = 0.98; p < 0.0001). In comparison with 64-slice MSCT, 2DE showed moderate correlation with CMR for the assessment of LVEF (r = 0.84; p < 0.0001), LVdV (r = 0.83; p < 0.0001) and LVsV (r = 0.80; p < 0.0001). However in RWM analysis, 2DE showed better accuracy than 64-slice MSCT (94.3% versus 82.4%) and closer agreement (κ = 0.89 versus 0.63) with CMR. Conclusion: 64-Slice MSCT correlates strongly with CMR in global LV function however in regional LV function 2DE showed better agreement with CMR than 64-slice MSCT

  14. Assessment of global and regional left ventricular function using 64-slice multislice computed tomography and 2D echocardiography: A comparison with cardiac magnetic resonance

    Energy Technology Data Exchange (ETDEWEB)

    Annuar, Bin Rapaee [Faculty of Medicine, University Malaysia Sarawak (Malaysia); Department of Cardiology, Sarawak General Hospital (Malaysia)], E-mail: rannuar@fmhs.unimas.my; Liew, Chee Khoon; Chin, Sze Piaw; Ong, Tiong Kiam [Department of Cardiology, Sarawak General Hospital (Malaysia); Seyfarth, M. Tobias [Sieman Medical Solution (Germany); Chan, Wei Ling; Fong, Yean Yip; Ang, Choon Kiat [Department of Cardiology, Sarawak General Hospital (Malaysia); Lin, Naing [Universiti Sains Malaysia (Malaysia); Liew, Houng Bang; Sim, Kui Hian [Department of Cardiology, Sarawak General Hospital (Malaysia)

    2008-01-15

    Objectives: To compare the assessment of global and regional left ventricular (LV) function using 64-slice multislice computed tomography (MSCT), 2D echocardiography (2DE) and cardiac magnetic resonance (CMR). Methods: Thirty-two consecutive patients (mean age, 56.5 {+-} 9.7 years) referred for evaluation of coronary artery using 64-slice MSCT also underwent 2DE and CMR within 48 h. The global left ventricular function which include left ventricular ejection fraction (LVEF), left ventricular end diastolic volume (LVdV) and left ventricular end systolic volume (LVsV) were determine using the three modalities. Regional wall motion (RWM) was assessed visually in all three modalities. The CMR served as the gold standard for the comparison between 64-slice MSCT with CMR and 2DE with CMR. Statistical analysis included Pearson correlation coefficient, Bland-Altman plots and {kappa}-statistics. Results: The 64-slice MSCT agreed well with CMR for assessment of LVEF (r = 0.92; p < 0.0001), LVdV (r = 0.98; p < 0.0001) and LVsV (r = 0.98; p < 0.0001). In comparison with 64-slice MSCT, 2DE showed moderate correlation with CMR for the assessment of LVEF (r = 0.84; p < 0.0001), LVdV (r = 0.83; p < 0.0001) and LVsV (r = 0.80; p < 0.0001). However in RWM analysis, 2DE showed better accuracy than 64-slice MSCT (94.3% versus 82.4%) and closer agreement ({kappa} = 0.89 versus 0.63) with CMR. Conclusion: 64-Slice MSCT correlates strongly with CMR in global LV function however in regional LV function 2DE showed better agreement with CMR than 64-slice MSCT.

  15. Assessment of global and regional left ventricular function using 64-slice multislice computed tomography and 2D echocardiography: a comparison with cardiac magnetic resonance.

    Science.gov (United States)

    Annuar, Bin Rapaee; Liew, Chee Khoon; Chin, Sze Piaw; Ong, Tiong Kiam; Seyfarth, M Tobias; Chan, Wei Ling; Fong, Yean Yip; Ang, Choon Kiat; Lin, Naing; Liew, Houng Bang; Sim, Kui Hian

    2008-01-01

    To compare the assessment of global and regional left ventricular (LV) function using 64-slice multislice computed tomography (MSCT), 2D echocardiography (2DE) and cardiac magnetic resonance (CMR). Thirty-two consecutive patients (mean age, 56.5+/-9.7 years) referred for evaluation of coronary artery using 64-slice MSCT also underwent 2DE and CMR within 48h. The global left ventricular function which include left ventricular ejection fraction (LVEF), left ventricular end diastolic volume (LVdV) and left ventricular end systolic volume (LVsV) were determine using the three modalities. Regional wall motion (RWM) was assessed visually in all three modalities. The CMR served as the gold standard for the comparison between 64-slice MSCT with CMR and 2DE with CMR. Statistical analysis included Pearson correlation coefficient, Bland-Altman plots and kappa-statistics. The 64-slice MSCT agreed well with CMR for assessment of LVEF (r=0.92; p<0.0001), LVdV (r=0.98; p<0.0001) and LVsV (r=0.98; p<0.0001). In comparison with 64-slice MSCT, 2DE showed moderate correlation with CMR for the assessment of LVEF (r=0.84; p<0.0001), LVdV (r=0.83; p<0.0001) and LVsV (r=0.80; p<0.0001). However in RWM analysis, 2DE showed better accuracy than 64-slice MSCT (94.3% versus 82.4%) and closer agreement (kappa=0.89 versus 0.63) with CMR. 64-Slice MSCT correlates strongly with CMR in global LV function however in regional LV function 2DE showed better agreement with CMR than 64-slice MSCT.

  16. Coronary artery imaging with 64-slice CT in atrial fibrillation patients: scanning method and post-processing techniques

    International Nuclear Information System (INIS)

    Xie Hongbo; Li Xiangmin; Peng Zhenpeng; Zhou Xuhui; Yan Chaogui; Li Ziping

    2010-01-01

    Objective: To discuss the clinical value of coronary artery imaging using 64-slice CT in patient with atrial fibrillation. Methods: All the cardiac volume data of 31 patients with atrial fibrillation were reconstructed using absolute time method. The images of 12 patients. The images of 31 patients who undeiwent contrast-enhanced CT coronary angiography were evaluated. The presence of stenosis on each segment of coronary arteries was recorded and their degree of stenosis was measured using the vessel analysis software.. The results of conventional coronary angiography (CAG) of the 10 patients were compared with CT coronary angiography. Results: The image quality of 364 coronary vessel segments on the images from 31 patients was evaluated and defined as excellent, fine, moderate or poor. The image quality was excellent, fine, moderate and poor in 194(53.3%), 82(22.5%), 41(11.3%) and 47(12.9%) vessel segments. Comparison was carried out between CTA findings and CAG findings of the 125 segments of the coronary arteries in the 10 patients who underwent CAG. The sensitivity and specificity of CTA for diagnosing vessel with stenosis (≥ 50% narrowing) was 85%(17/20) and 95.2% (100/105). Conclusion: Coronary artery imaging using 64-slice CT is useful in patient with atrial fibrillation. (authors)

  17. Individualized radiation dose control in 256-slice CT coronary angiography (CTCA) in retrospective ECG-triggered helical scans: Using a measure of body size to adjust tube current selection

    Energy Technology Data Exchange (ETDEWEB)

    Li, Jing-Lei, E-mail: lijinglei80@126.com [Department of Radiology, Guangdong Academy of Medical Sciences, Guangdong General Hospital, 106 Zhongshan Er Road, Guangzhou 510080 (China); Huang, Mei-Ping, E-mail: huang_meiping@yahoo.com.cn [Department of Radiology, Guangdong Academy of Medical Sciences, Guangdong General Hospital, 106 Zhongshan Er Road, Guangzhou 510080 (China); Liang, Chang-Hong, E-mail: cjr.lchh@vip.163.com [Department of Radiology, Guangdong Academy of Medical Sciences, Guangdong General Hospital, 106 Zhongshan Er Road, Guangzhou 510080 (China); Zhao, Zhen-Jun, E-mail: junabc2006@hotmail.com [Department of Radiology, Guangdong Academy of Medical Sciences, Guangdong General Hospital, 106 Zhongshan Er Road, Guangzhou 510080 (China); Liu, Hui, E-mail: liuhuijiujiu@gmail.com [Department of Radiology, Guangdong Academy of Medical Sciences, Guangdong General Hospital, 106 Zhongshan Er Road, Guangzhou 510080 (China); Cui, Yan-Hai, E-mail: yanhai_cui@126.com [Department of Radiology, Guangdong Academy of Medical Sciences, Guangdong General Hospital, 106 Zhongshan Er Road, Guangzhou 510080 (China); Liu, Qi-Shun, E-mail: liuqishun@yeah.net [Department of Radiology, Guangdong Academy of Medical Sciences, Guangdong General Hospital, 106 Zhongshan Er Road, Guangzhou 510080 (China); Zhang, Jin-E., E-mail: zhjine@yahoo.com.cn [Department of Radiology, Guangdong Academy of Medical Sciences, Guangdong General Hospital, 106 Zhongshan Er Road, Guangzhou 510080 (China); Yang, Lin, E-mail: yanglin001517@163.com [Department of Radiology, Guangdong Academy of Medical Sciences, Guangdong General Hospital, 106 Zhongshan Er Road, Guangzhou 510080 (China); Ivanc, Thomas B., E-mail: Thomas.ivanc@philips.com [CT Clinical Science, Philips Healthcare, Highland Heights, OH (United States); Yanof, Jeffrey H., E-mail: Jeffrey.yanof@philips.com [CT Clinical Science, Philips Healthcare, Highland Heights, OH (United States)

    2012-11-15

    Purpose: To reduce radiation dose for retrospective ECG-triggered helical 256-slice CTCA by determining an optimal body size index to prospectively adjust tube current. Methods: 102 consecutive patients with suspected CAD underwent retrospective ECG-triggered CTCA using 256-slice CT scanner. Six body size indexes including BMI, nipple level (NL) bust, thoracic anteroposterior diameter at NL, chest circumference (CC) at NL, left main and right coronary artery (RCA) origin level were measured and their correlation with noise was evaluated using linear regression. An equation was developed to use this index to adjust tube current. Additional 102 consecutive patients were scanned with the index-based mA s adjustment. A t-test for independent samples was used to compare radiation dose levels with and without the index-based mA s selection method. Results: Linear regression indicated that CC RCA had the best correlation with noise (R{sup 2} = 0.603). Effective radiation dose was reduced from 16.6 {+-} 0.9 to 9.8 {+-} 2.7 mSv (p < 0.01), i.e. 40.9% lower dose with the CC RCA-adapted tube current method. The image quality scores indicated no significant difference with and without the size-based mA s selection method. Conclusion: An accessible measure of body size, such as CC RCA, can be used to adapt tube current for individualized radiation dose control.

  18. Individualized radiation dose control in 256-slice CT coronary angiography (CTCA) in retrospective ECG-triggered helical scans: Using a measure of body size to adjust tube current selection

    International Nuclear Information System (INIS)

    Li, Jing-Lei; Huang, Mei-Ping; Liang, Chang-Hong; Zhao, Zhen-Jun; Liu, Hui; Cui, Yan-Hai; Liu, Qi-Shun; Zhang, Jin-E.; Yang, Lin; Ivanc, Thomas B.; Yanof, Jeffrey H.

    2012-01-01

    Purpose: To reduce radiation dose for retrospective ECG-triggered helical 256-slice CTCA by determining an optimal body size index to prospectively adjust tube current. Methods: 102 consecutive patients with suspected CAD underwent retrospective ECG-triggered CTCA using 256-slice CT scanner. Six body size indexes including BMI, nipple level (NL) bust, thoracic anteroposterior diameter at NL, chest circumference (CC) at NL, left main and right coronary artery (RCA) origin level were measured and their correlation with noise was evaluated using linear regression. An equation was developed to use this index to adjust tube current. Additional 102 consecutive patients were scanned with the index-based mA s adjustment. A t-test for independent samples was used to compare radiation dose levels with and without the index-based mA s selection method. Results: Linear regression indicated that CC RCA had the best correlation with noise (R 2 = 0.603). Effective radiation dose was reduced from 16.6 ± 0.9 to 9.8 ± 2.7 mSv (p < 0.01), i.e. 40.9% lower dose with the CC RCA-adapted tube current method. The image quality scores indicated no significant difference with and without the size-based mA s selection method. Conclusion: An accessible measure of body size, such as CC RCA, can be used to adapt tube current for individualized radiation dose control.

  19. Evaluation of coronary calcifications with 64-slice CT - variability of the scores and the influence of the reconstruction interval

    International Nuclear Information System (INIS)

    Weininger, M.; Ritter, C.O.; Beer, M.; Hahn, D.; Beissert, M.

    2007-01-01

    Purpose: To evaluate the variability of coronary calcium scores depending on the image reconstruction interval using a 64-slice CT scanner. Materials and Methods: 30 patients (18 male, 12 female; mean age 57 ± 9 yrs; mean heart rate 66 ± 10 bpm) underwent coronary calcium scoring using a 64-slice CT scanner (Somatom Sensation 64, Siemens Medical Solutions, Erlangen) and a standardized scanning protocol. Oral β-blockers were administered to 12 patients with a baseline heart rate > 70 bpm. Images were reconstructed in 10 % increments from 10 - 100 % of the RR interval. Two blinded experienced observers independently calculated Agatston (AS), calcium mass (MS) and volume scores (VS) for every reconstructed image series. The results were compared to similar studies for 16-slice CT scanners. Results: The mean values and mean coefficients of variation among all patients were as follows: AS, 397 ± 829, 109 % MS, 88 ± 225, 154 % VS, 335 ± 669, 100 %. Regarding the reconstruction intervals, the mean coefficients of variation were as follows: 107 % (AS), 97 % (VS), 116 % (MS). No specific image reconstruction interval with statistically significant lower variability for each score could be identified. High inter-observer agreement was achieved (K = 0.98). With statistical significance (p < 0.05) 10/30 patients (pts) were able to be allocated to more than one risk group (RG): 6 pts = 2 RG; 3 pts 3 RG; 1 pts = 4 RG. The scores for 5/30 patients were zero for at least one reconstruction interval, but further reconstructions revealed calcifications. The number of patients assignable to different risk groups was significantly lower compared to published data using a 16-slice scanner (p < 0.05). Conclusion: Coronary calcium scores determined using a 64-slice scanner display a wide range of variability depending on the image reconstruction interval as already described for 16-slice CT scanners. However, compared to previous studies, our data indicate that this vendor

  20. Acute subarachnoid hemorrhage: using 64-slice multidetector CT angiography to ''triage'' patients' treatment

    Energy Technology Data Exchange (ETDEWEB)

    Agid, R.; Lee, S.K.; Willinsky, R.A.; Farb, R.I.; TerBrugge, K.G. [Toronto Western Hospital, Division of Neuroradiology, Department of Medical Imaging, Toronto, Ontario (Canada)

    2006-11-15

    To evaluate the clinical role of CT angiography (CTA) in patients with acute subarachnoid hemorrhage (SAH) for treatment decision-making. Consecutive patients with acute SAH had CTA using a 64-slice scanner for initial clinical decision-making. Image processing included multiplanar volume reformatted (MPVR) maximum intensity projections (MIP) and 3D volume-rendered reconstructions. CTAs were used for (1) evaluating the cause of SAH, and (2) triaging aneurysm-bearing patients to the more appropriate management, either surgical clipping or endovascular coiling. CTA findings were confirmed by neurosurgical exploration or catheter angiography (digital subtraction angiography, DSA). Successful coiling provided evidence that triaging to endovascular treatment was correct. Included in the study were 73 patients. CTA findings were confirmed by DSA or neurosurgical operation in 65 patients, and of these 65, 47 had aneurysmal SAH, 3 had vasculitis, 1 had arterial dissection and 14 had no underlying arterial abnormality. The cause of SAH was detected with CTA in 62 out of the 65 patients (95.4%, sensitivity 94%, specificity 100%). CTA revealed the aneurysm in 46 of 47 patients (98%, sensitivity 98%, specificity 100%, positive predictive value 100%, negative predictive value 82.3%), 1 of 3 vasculitides and 1 of 1 dissection. Of the 46 patients with aneurysm, 44 (95.7%) were referred for treatment based on CTA. In 2 patients (2 of 46, 4.4%) CTA was not informative enough to choose treatment requiring DSA. Of the 44 patients, 27 (61.4%) were referred to endovascular treatment and successful coiling was achieved in 25 (25 of 27, 92.6%). CTA using a 64-slice scanner is an accurate tool for detecting and characterizing aneurysms in acute SAH. CTA is useful in the decision process whether to coil or clip an aneurysm. (orig.)

  1. Understanding about diagnosis of acute small bowel retrograde intussusception in adults by means of 64-slice-spinal CT

    International Nuclear Information System (INIS)

    Jiang Ruizhou; Chen Jincheng

    2009-01-01

    Objective: To have a further study of the value of MSCT in diagnosing acute small bowel retrograde intussusception in adults by means of 64-slice-spinal CT. Methods: A 46-year-old female patient with the history of abdominal operation was found having acute mechanical small bowel obstruction through plain X-ray radiograph. 64-slice MSCT was performed afterwards (plain scan + 3 stage contrast scans). Hence, evidence is provided for operation. Results: Using the technique of MSCT for the patient can promptly approach the diagnosis of jejuno-jejunal intussusception with severe bowel obstruction; no small bowel tumor or other organic lesion found in this case. With the patient who has the history of abdominal operations, MSCT can predict the reason of adhesion causing bowel intussusception, and provide the evidence for operation; whereas MSCT with contrast media offers a further investigation of the blood supply to the bowels through SMA, and observation of blood circulation through the intussuscepting site, which represents venous congestion of intussusception. This case is a retrograde small bowel intussusception and confirmed with operation evidence. A greater amount of gas and fluid is accumulated between the dilated space of middle-distal portion of intussusceptum and intussuscipiens. Nevertheless, less gas at the proximal portion and that can be an important sign for retrograde intussusception. Conclusion: MSCT is a good choice of examination for diagnosis of adult's intussusception. As the literature mentioned the advantages of MSCT for observing the circulation of intussusceptum and whether the diagnosis is antegrade or retrograde intussusception is also essential. (authors)

  2. High-resolution ex vivo imaging of coronary artery stents using 64-slice computed tomography - initial experience

    International Nuclear Information System (INIS)

    Rist, Carsten; Nikolaou, Konstantin; Wintersperger, Bernd J.; Reiser, Maximilian F.; Becker, Christoph R.; Flohr, Thomas

    2006-01-01

    The aim of the study was to evaluate the potential of new-generation multi-slice computed tomography (CT) scanner technology for the delineation of coronary artery stents in an ex vivo setting. Nine stents of various diameters (seven stents 3 mm, two stents 2.5 mm) were implanted into the coronary arteries of ex vivo porcine hearts and filled with a mixture of an iodine-containing contrast agent. Specimens were scanned with a 16-slice CT (16SCT) machine; (Somatom Sensation 16, Siemens Medical Solutions), slice thickness 0.75 mm, and a 64-slice CT (64SCT, Somatom Sensation 64), slice-thickness 0.6 mm. Stent diameters as well as contrast densities were measured, on both the 16SCT and 64SCT images. No significant differences of CT densities were observed between the 16SCT and 64SCT images outside the stent lumen: 265±25HU and 254±16HU (P=0.33), respectively. CT densities derived from the 64SCT images and 16SCT images within the stent lumen were 367±36HU versus 402±28HU, P<0.05, respectively. Inner and outer stent diameters as measured from 16SCT and 64SCT images were 2.68±0.08 mm versus 2.81±0.07 mm and 3.29±0.06 mm versus 3.18±0.07 mm (P<0.05), respectively. The new 64SCT scanner proved to be superior in the ex vivo assessment of coronary artery stents to the conventional 16SCT machine. Increased spatial resolution allows for improved assessment of the coronary artery stent lumen. (orig.)

  3. Preoperative assessment of gastric artery in patients with gastric cancer by CT angiography on 64-slice spiral CT

    International Nuclear Information System (INIS)

    Tang Lei; Zhang Xiaopeng; Sun Yingshi; Cao Kun; Qi Liping; Cui Yong; Wang Ning

    2010-01-01

    Objective: To evaluate the efficacy of different three-dimensional CTA methods on 64-slice sprial CT in the preoperative assessment of gastric arteries and their variations. Methods: Sixty-six consecutive patients with gastric cancer who underwent 64-slice spiral CT examinations preoperatively were retrospectively studied. To get the STS-MIP images, the thickness of slab was adjusted according to the inner diameter of targeted blood vessels and their cross-layer distribution. After four weeks, the AVVR images of all cases was got by the auto-vessel technique. The demonstration rates and origins of the direct and indirect feeding arteries were analyzed on AVVR and STS-MIP. McNemar tests were used to compare the detection rates of gastric feeding arteries by STS-MIP and AVVR. The relationship between CT value and display rate of vessels was analyzed using independent-samples t test. The variations of blood vessels were analyzed. Results: The display rate of indirect feeding arteries were all 100% (66/66) by STS-MIP and AVVR. The display rates of left gastric artery (LGA) and right gastroepiploic artery (RGEA) were 98.5% (65/66), 100.0% (66/66) and 97.0% (64/66), 100.0% (66/66) by STS-MIP and AVVR respectively. The display rates of right artery (RGA), left gastroepiploic artery (LGEA), short gastric artery (SGA) and posterior gastric artery (RGA), left gastroepiploic artery (LGEA), short gastric artery (SGA) and posterior gastric artery (PGA) by AVVR were lower than those of STS-MIP with statistical significances [RGA: 68.2% (45/66) vs. 98.5% (65/66), P<0.01; LGEA: 53.0% (35/66) vs. 97.0% (64/66), P<0.01; SGA: 7.6%(5/66) vs. 59.1% (39/66), P<0.01; PGA: 18.2% (12/66) vs. 63.6% (42/66), P<0.01]. The demonstration rates of LGEA, RGEA and SGA increased accompanied with the increasing of CT value in celiac axis (LGEA: 35 cases displayed with mean CT value of (272 ± 44) HU, 31 cases did not display with mean CT value of (229 ± 42) HU, t=4.043, P<0.01; RGEA: 64 cases

  4. Beam hardening artifacts by dental implants: Comparison of cone-beam and 64-slice computed tomography scanners

    Directory of Open Access Journals (Sweden)

    Farzad Esmaeili

    2013-01-01

    Full Text Available Background: Cone beam computed tomography (CBCT is an alternative to a computed tomography (CT scan, which is appropriate for a wide range of craniomaxillofacial indications. The long-term use of metallic materials in dentistry means that artifacts caused by metallic restorations in the oral cavity should be taken into account when utilizing CBCT and CT scanners. The aim of this study was to quantitatively compare the beam hardening artifacts produced by dental implants between CBCT and a 64-Slice CT scanner. Materials and Methods: In this descriptive study , an implant drilling model similar to the human mandible was used in the present study. The implants (Dentis were placed in the canine, premolar and molar areas. Three series of scans were provided from the implant areas using Somatom Sensation 64-slice and NewTom VGi (CBCT CT scanners. Identical images were evaluated by three radiologists. The artifacts in each image were determined based on pre-determined criteria. Kruskal-Wallis test was used to compare mean values; Mann-Whitney U test was used for two-by-two comparisons when there was a statistical significance ( P < 0.05. Results: The images of the two scanners had similar resolutions in axial sections ( P = 0.299. In coronal sections, there were significant differences in the resolutions of the images produced by the two scanners ( P < 0.001, with a higher resolution in the images produced by NewTom VGi scanner. On the whole, there were significant differences between the resolutions of the images produced by the two CT scanners ( P < 0.001, with higher resolution in the images produced by NewTom VGi scanner in comparison to those of Somatom Sensation. Conclusion: Given the high quality of the images produced by NewTom VGi and the lower costs in comparison to CT, the use of the images of this scanner in dental procedures is recommended, especially in patients with extensive restorations, multiple prostheses and previous implants.

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

    International Nuclear Information System (INIS)

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

    2006-01-01

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

  6. The comparison of coronary arteries imaging features between Uygur and Han populations in Xinjiang with 64-slice spiral CT

    International Nuclear Information System (INIS)

    Pan Cunxue; Zhao Yanping; Liu Wenya; Wang Haitao; Dang Jun; Yang Wen; Sun Yajing; Li Xiaoyu

    2010-01-01

    Objective: To analyze the imaging findings of coronary angiography using 64-slice row CT and investigate the difference of coronary artery's morphological characteristics between Uygur and Han populations. Methods: A retrospective study was made to coronary CT angiographic images of 88 Uygur cases matched with 88 Han cases. The data were analyzed with X 2 test and paired Wilcoxon test. Results: The coronary CT angiographic findings were different between Uygur population and Han population in the following aspects: there were 62, 18, and 8 cases with the left coronary artery originating from intra-sinus, para-sinus and extra-sinus location respectively in Uygur population, while there were 73, 14, and 8 cases in Han population respectively (t=8319, P 2 =5.8381, P 2 =5.1948, P<0.05). The cases with LCA variations were 28 and 49 cases in the two populations respectively (t=2692, P<0.05) and the number with RCA variations were 33 and 27 cases in the two populations respectively (t=968, P<0.05). Conclusions: There are lots of differences of the coronary artery morphology between the Uygur and Han populations. Firstly, these differences may be related to different patterns in coronary angiography. Secondly, these differences may be related to differences between Uygur and Han populations in the incidence and severity of coronary heart disease. (authors)

  7. Clinical evaluation of 64-slice CT assessment of global left ventricular function using automated cardiac phase selection

    International Nuclear Information System (INIS)

    Joemai, Raoul M.S.; Geleijns, Joemai; Veldkamp, Wouter J.H.; Kroft, Lucia J.M.

    2008-01-01

    Left ventricular (LV) function provides prognostic information regarding the morbidity and mortality of patients. An automated cardiac phase selection algorithm has the potential to support the assessment of LV function with computed tomography (CT). This algorithm is clinically evaluated for 64-slice cardiac CT. Examinations of twenty consecutive patients were selected. Electrocardiogram gated contrast-enhanced CT was performed. Reconstructions were performed using an automated and a manual method, followed by the determination of the global LV function. Significances were tested using 2-sided Student's t-tests. Reduction in post processing time and storage capacity were estimated. A slightly smaller mean end-systolic volume was found with the automated method (52±18 ml vs 54±17 ml, p=0.02, r=0.99). The mean LV ejection fraction was slightly larger with the automated method (65±8% vs 64±8%, p=0.004, r=0.99). The estimated reduction in post processing time was maximal 5 min per patient with a potential 80% data storage reduction. Results of the automated phase selection algorithm are similar to the manual method. The automated tool reduces post processing time, reconstruction time and transfer time. (author)

  8. Non-invasive detection of aortic and coronary atherosclerosis in homozygous familial hypercholesterolemia by 64 slice multi-detector row computed tomography angiography

    Science.gov (United States)

    Homozygous familial hypercholesterolemia (HoFH) is a rare disorder characterized by the early onset of atherosclerosis, often at the ostia of coronary arteries. In this study we document for the first time that aortic and coronary atherosclerosis can be detected using 64 slice multiple detector row ...

  9. Prognostic value of absence or presence of coronary artery disease determined by 64-slice computed tomography coronary angiography A systematic review and meta-analysis

    DEFF Research Database (Denmark)

    Abdulla, Jawdat; Asferg, Camilla Lundegaard; Kofoed, Klaus Fuglsang

    2011-01-01

    To determine via a meta-analysis the prognostic value of 64-slice computed tomography angiography (CTA) by quantifying risk of major adverse cardiac events (MACE) in different patient groups classified according to CT angiographic findings. A systematic literature search and meta...

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

    International Nuclear Information System (INIS)

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

    2008-01-01

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

  11. Quantification of coronary artery stenoses. Comparison of 64-slice and dual source CT angiography with cardiac catheterization

    International Nuclear Information System (INIS)

    Busch, Stephanie; Nikolaou, K.; Johnson, T.; Rist, C.; Knez, A.; Reiser, M.; Becker, C.

    2007-01-01

    Until now stenoses of the coronary arteries have been evaluated visually with CT angiography. Therefore, the results were highly dependent on subjective factors inherent in the examiner. New software tools for semiquantitative analysis (CT-QCA, quantitative coronary assessment) might be adequate to improve the diagnostic accuracy und reproducibility. CTAs of 20 patients were analyzed. Ten patients each were evaluated using 64-slice CT (64SCT) and dual source CT (DSCT) (Somatom Sensation 64 and Somatom Definition, Siemens Medical Solutions, Forchheim), respectively. Two radiologists independently evaluated the data visually and with the help of a software tool (Syngo Circulation, Siemens Medical Solutions, Forchheim). The results of the quantitative assessment of the invasive heart catheterization served as the reference standard. Sensitivity and specificity as well as the correlation coefficient, the systematic error, and the interobserver agreement (kappa) were determined. In each of both patient groups 12 stenoses were detected. For the detection of stenoses >75%, sensitivity and specificity for the visual evaluation using the 64SCT were 100% and 90%, and with the CT-QCA both were 100%. For the DSCT sensitivity and specificity were 100% for both the visual and semiautomated evaluation. The Bland-Altman plot of the results of the 64SCT showed an overestimation of 3.3% (±62.7%/56.2%) compared to the heart catheterization. The results of the DSCT exhibited an overestimation of 6.2% (±33.1%/19.8%). The interobserver agreement of the CT-QCA and the visual evaluation showed a kappa value of 0.75 and for DSCT of 1.0. The results showed a good correlation of grading stenosis between the software-assisted evaluation and the results of the coronary catheter angiography. The promising results of the DSCT are due to a superior temporal resolution compared to the 64SCT. Confirmation of these data by trials in larger patient collectives is warranted. (orig.) [de

  12. 64-Slice multidetector row CT angiography of the abdomen: comparison of low versus high concentration iodinated contrast media in a porcine model

    Science.gov (United States)

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

    2011-01-01

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

  13. Association of traditional cardiovascular risk factors with coronary plaque sub-types assessed by 64-slice computed tomography angiography in a large cohort of asymptomatic subjects.

    Science.gov (United States)

    Rivera, Juan J; Nasir, Khurram; Cox, Pedro R; Choi, Eue-Keun; Yoon, Yeonyee; Cho, Iksung; Chun, Eun-Ju; Choi, Sang-Il; Blumenthal, Roger S; Chang, Hyuk-Jae

    2009-10-01

    Although prior studies have shown that traditional cardiovascular (CV) risk factors are associated with the burden of coronary atherosclerosis, less is known about the relationship of risk factors with coronary plaque sub-types. Coronary computed tomography angiography (CCTA) allows an assessment of both, total disease burden and plaque characteristics. In this study, we investigate the relationship between traditional CV risk factors and the presence and extent of coronary plaque sub-types in a large group of asymptomatic individuals. The study population consisted of 1015 asymptomatic Korean subjects (53+/-10 years; 64% were males) free of known CV disease who underwent 64-slice CCTA as part of a health screening evaluation. We analyzed plaque characteristics on a per-segment basis according to the modified American Heart Association classification. Plaques in which calcified tissue occupied more than 50% of the plaque area were classified as calcified (CAP), NCAP). A total of 215 (21%) subjects had coronary plaque while 800 (79%) had no identifiable disease. Multivariate regression analysis demonstrated that increased age (per decade) and gender are the strongest predictors for the presence of any coronary plaque or the presence of at least one segment of CAP and MCAP (any plaque-age: OR 2.89; 95% CI 2.34, 3.56; male gender: OR 5.21; 95% CI 3.20, 8.49; CAP-age: OR 2.75; 95% CI 2.12, 3.58; male gender: 4.78; 95% CI 2.48, 9.23; MCAP-age: OR 2.62; 95% CI 2.02, 3.39; male gender: OR 4.15; 95% CI 2.17, 7.94). The strongest predictors for the presence of any NCAP were gender (OR 3.56; 95% CI 1.96-6.55) and diabetes mellitus (OR 2.87; 95% CI 1.63-5.08). When looking at the multivariate association between the presence of >/=2 coronary segments with a plaque sub-type and CV risk factors, male gender was the strongest predictor for CAP (OR 7.31; 95% CI 2.12, 25.20) and MCAP (OR 5.54; 95% CI 1.84, 16.68). Alternatively, smoking was the strongest predictor for the presence

  14. Coronary calcium score as gatekeeper for 64-slice computed tomography coronary angiography in patients with chest pain: per-segment and per-patient analysis

    International Nuclear Information System (INIS)

    Palumbo, Anselmo Alessandro; Cademartiri, Filippo; Maffei, Erica; Martini, Chiara; Tarantini, Giuseppe; Di Tanna, Gian Luca; Berti, Elena; Grilli, Roberto; Casolo, Giancarlo; Brambilla, Valerio; Cerrato, Marcella; Rotondo, Antonio; Weustink, Annick C.; Mollet, Nico R.A.

    2009-01-01

    We sought to investigate the performance of 64-slice CT in symptomatic patients with different coronary calcium scores. Two hundred patients undergoing 64-slice CT coronary angiography for suspected coronary artery disease were enrolled into five groups based on Agatston calcium score using the Mayo Clinic risk stratification: group 1: score 0, group 2: score 1-10, group 3: score 11-100, group 4: score 101-400, and group 5: score > 401. Diagnostic accuracy for the detection of significant (≥50% lumen reduction) coronary artery stenosis was assessed on a per-segment and per-patient base using quantitative coronary angiography as the gold standard. For groups 1 through 5, sensitivity was 97, 96, 91, 90, 92%, and specificity was 99, 98, 96, 88, 90%, respectively, on a per-segment basis. On a per-patient basis, the best diagnostic performance was obtained in group 1 (sensitivity 100% and specificity 100%) and group 5 (sensitivity 95% and specificity 100%). Progressively higher coronary calcium levels affect diagnostic accuracy of CT coronary angiography, decreasing sensitivity and specificity on a per-segment base. On a per-patient base, the best results in terms of diagnostic accuracy were obtained in the populations with very low and very high cardiovascular risk. (orig.)

  15. Usefulness of 64-slice MDCT for follow-up of young children with coronary artery aneurysm due to Kawasaki disease: initial experience.

    Science.gov (United States)

    Peng, Yun; Zeng, Jinjin; Du, Zhongdong; Sun, Guoqiang; Guo, Huling

    2009-03-01

    To evaluate the initial application and value of 64-slice multidetector computed tomography as an alternative diagnostic modality in the follow-up of young children with coronary artery aneurysm due to Kawasaki disease. Twelve boys (mean age 5.1 years, range 1.8-7.8 years) for follow-up (time range from 1.1 to 5.1 years) of known Kawasaki disease and coronary artery aneurysm underwent 64-slice MDCT ECG-gated coronary angiography. All data were acquired without breath holding. Two pediatric radiologists independently assessed image quality and the diameter of all coronary segments were measured for each patient. The number, position, shape and size of each coronary artery aneurysm were observed and compared with those of ECHO performed previously. A total of 118/156 segments permitted visualization with diagnostic image quality, the CT measurements showed good inter-observer and intra-observer reliability, coefficients were 0.93 and 0.88, respectively. A total of 30 coronary artery aneurysms were identified with measured mean of 7.5+/-3.8 mm in diameter, and of 12.4+/-9.1 mm in longitudinal lengths.10 tumors were small, 8 tumors were medium and 12 tumors were giant aneurysm. The affected segments included LM7/12(58.3%), 9/12(75%) of LAD1, 4/12(33.3%) of LAD2, 2/12(16.7%) of LCX1; 6/12(50%) of RCA1, 9/12(75%) of RCA2 and 4/12(33.3%) of RCA3, including affected two segments in 9 tumors and three segments in 1 tumor. Calcifications were found in 5 aneurysms and 3/5 with thrombosis; six stenotic segments were found. ECHO failed to detect 8 tumors with 2/8 in LAD, 1/8 in LCX and 5/8 in RCA, and those included 4 small aneurysms. The use of 64-slice MDCT angiography proved valuable for monitoring young children with Kawasaki disease. However, further study is necessary to specify the sensitivity and specificity of MDCT in the follow-up.

  16. Usefulness of 64-slice MDCT for follow-up of young children with coronary artery aneurysm due to Kawasaki disease: Initial experience

    International Nuclear Information System (INIS)

    Peng Yun; Zeng Jinjin; Du Zhongdong; Sun Guoqiang; Guo Huling

    2009-01-01

    To evaluate the initial application and value of 64-slice multidetector computed tomography as an alternative diagnostic modality in the follow-up of young children with coronary artery aneurysm due to Kawasaki disease. Twelve boys (mean age 5.1 years, range 1.8-7.8 years) for follow-up (time range from 1.1 to 5.1 years) of known Kawasaki disease and coronary artery aneurysm underwent 64-slice MDCT ECG-gated coronary angiography. All data were acquired without breath holding. Two pediatric radiologists independently assessed image quality and the diameter of all coronary segments were measured for each patient. The number, position, shape and size of each coronary artery aneurysm were observed and compared with those of ECHO performed previously. A total of 118/156 segments permitted visualization with diagnostic image quality, the CT measurements showed good inter-observer and intra-observer reliability, coefficients were 0.93 and 0.88, respectively. A total of 30 coronary artery aneurysms were identified with measured mean of 7.5 ± 3.8 mm in diameter, and of 12.4 ± 9.1 mm in longitudinal lengths.10 tumors were small, 8 tumors were medium and 12 tumors were giant aneurysm. The affected segments included LM7/12(58.3%), 9/12(75%) of LAD1, 4/12(33.3%) of LAD2, 2/12(16.7%) of LCX1; 6/12(50%) of RCA1, 9/12(75%) of RCA2 and 4/12(33.3%) of RCA3, including affected two segments in 9 tumors and three segments in 1 tumor. Calcifications were found in 5 aneurysms and 3/5 with thrombosis; six stenotic segments were found. ECHO failed to detect 8 tumors with 2/8 in LAD, 1/8 in LCX and 5/8 in RCA, and those included 4 small aneurysms. The use of 64-slice MDCT angiography proved valuable for monitoring young children with Kawasaki disease. However, further study is necessary to specify the sensitivity and specificity of MDCT in the follow-up.

  17. Feasibility study of automatic tube current modulation in low-dose thoracic imaging for young children with 64-slice spiral CT

    International Nuclear Information System (INIS)

    Peng Yun; Li Jianyin; Zhang Qifeng; Liu Yue; Wang Bei; Zheng Jinjin

    2008-01-01

    Objective: To assess the feasibility of using an automatic tube current modulation (ATCM) method to obtain consistent image quality with reduced radiation dose for young children undergoing chest scans with a set of 64-slice spiral CT. Methods: Fifty young children underwent chest scans on a GE 64-slice VCT with automatic tube current modulation. The noise index (NI) for this study group was set to 8 or 9 based on the proposed reference for pediatric chest imaging in our hospital. We compared image quality and radiation dose for the study group with the age-matched control group of 50 young children acquired with standard protocol of fixed-mAs (120 and 150 mAs for under 1 and above 1 year old, respectively). The volume CT dose index(CTDIvol) values were recorded for both groups. Two experienced pediatric radiologists assessed image quality on a 5-point scale with 5 being the best. Scores greater than or equal to 3 were considered clinically acceptable. The degree of interobserver concordance was determined by Kappa statistics. Results: The average objective image noise and CTDIvol for control group was (4.78±0.58) and (6.68±0.62) mGy, respectively. For the study group the mean value of objective mAs was (41.6±11.6) (20-79 mAs) with mean CTDIvol of (2.34±0.71) mGy, and the use of ATCM produced mean noise of (7.84±0.66). The average CTDIvol with the use of NI of 8-9 was about 65% lower than that with the fixed mAs setting. The mean image quality score for the study group and control group was (3.46±0.40) and (4.65±0.46) respectively. All studies had acceptable image quality, and there was good inter-observer agreement in diagnostic acceptability (Kappa=0.474 and 0.536). Conclusion: The automatic tube current modulation method could be used to obtain consistent image quality for young children undergoing 64-slice MSCT chest scans. With proper noise level setting (NI=8 or 9), one may obtain clinically acceptable images with much reduced radiation dose. (authors)

  18. Quantitative parameters to compare image quality of non-invasive coronary angiography with 16-slice, 64-slice and dual-source computed tomography

    International Nuclear Information System (INIS)

    Burgstahler, Christof; Reimann, Anja; Brodoefel, Harald; Tsiflikas, Ilias; Thomas, Christoph; Heuschmid, Martin; Daferner, Ulrike; Drosch, Tanja; Schroeder, Stephen; Herberts, Tina

    2009-01-01

    Multi-slice computed tomography (MSCT) is a non-invasive modality to visualize coronary arteries with an overall good image quality. Improved spatial and temporal resolution of 64-slice and dual-source computed tomography (DSCT) scanners are supposed to have a positive impact on diagnostic accuracy and image quality. However, quantitative parameters to compare image quality of 16-slice, 64-slice MSCT and DSCT are missing. A total of 256 CT examinations were evaluated (Siemens, Sensation 16: n=90; Siemens Sensation 64: n=91; Siemens Definition: n=75). Mean Hounsfield units (HU) were measured in the cavum of the left ventricle (LV), the ascending aorta (Ao), the left ventricular myocardium (My) and the proximal part of the left main (LM), the left anterior descending artery (LAD), the right coronary artery (RCA) and the circumflex artery (CX). Moreover, the ratio of intraluminal attenuation (HU) to myocardial attenuation was assessed for all coronary arteries. Clinical data [body mass index (BMI), gender, heart rate] were accessible for all patients. Mean attenuation (CA) of the coronary arteries was significantly higher for DSCT in comparison to 64- and 16-slice MSCT within the RCA [347±13 vs. 254±14 (64-MSCT) vs. 233±11 (16-MSCT) HU], LM (362±11/275 ± 12/262±9), LAD (332±17/248±19/219±14) and LCX (310±12/210±13/221±10, all p<0.05), whereas there was no significant difference between DSCT and 64-MSCT for the LV, the Ao and My. Heart rate had a significant impact on CA ratio in 16-slice and 64-slice CT only (p<0.05). BMI had no impact on the CA ratio in DSCT only (p<0.001). Improved spatial and temporal resolution of dual-source CT is associated with better opacification of the coronary arteries and a better contrast with the myocardium, which is independent of heart rate. In comparison to MSCT, opacification of the coronary arteries at DSCT is not affected by BMI. The main advantage of DSCT lies with the heart rate independency, which might have a

  19. Usefulness of 64-slice MDCT for follow-up of young children with coronary artery aneurysm due to Kawasaki disease: Initial experience

    Energy Technology Data Exchange (ETDEWEB)

    Peng Yun [Imaging Center, Beijing Children' s Hospital Affiliated to Capital Medical University, 56, Nanlishi Road, Xicheng District, Beijing 100045 (China)], E-mail: ppengyun@yahoo.com; Zeng Jinjin [Imaging Center, Beijing Children' s Hospital Affiliated to Capital Medical University, 56, Nanlishi Road, Xicheng District, Beijing 100045 (China); Du Zhongdong [Pediatric Cardiovascular Department, Beijing Children' s Hospital Affiliated to Capital Medical University, 56, Nanlishi Road, Xicheng District, Beijing 100045 (China); Sun Guoqiang [Imaging Center, Beijing Children' s Hospital Affiliated to Capital Medical University, 56, Nanlishi Road, Xicheng District, Beijing 100045 (China); Guo Huling [Pediatric Cardiovascular Department, Beijing Children' s Hospital Affiliated to Capital Medical University, 56, Nanlishi Road, Xicheng District, Beijing 100045 (China)

    2009-03-15

    To evaluate the initial application and value of 64-slice multidetector computed tomography as an alternative diagnostic modality in the follow-up of young children with coronary artery aneurysm due to Kawasaki disease. Twelve boys (mean age 5.1 years, range 1.8-7.8 years) for follow-up (time range from 1.1 to 5.1 years) of known Kawasaki disease and coronary artery aneurysm underwent 64-slice MDCT ECG-gated coronary angiography. All data were acquired without breath holding. Two pediatric radiologists independently assessed image quality and the diameter of all coronary segments were measured for each patient. The number, position, shape and size of each coronary artery aneurysm were observed and compared with those of ECHO performed previously. A total of 118/156 segments permitted visualization with diagnostic image quality, the CT measurements showed good inter-observer and intra-observer reliability, coefficients were 0.93 and 0.88, respectively. A total of 30 coronary artery aneurysms were identified with measured mean of 7.5 {+-} 3.8 mm in diameter, and of 12.4 {+-} 9.1 mm in longitudinal lengths.10 tumors were small, 8 tumors were medium and 12 tumors were giant aneurysm. The affected segments included LM7/12(58.3%), 9/12(75%) of LAD1, 4/12(33.3%) of LAD2, 2/12(16.7%) of LCX1; 6/12(50%) of RCA1, 9/12(75%) of RCA2 and 4/12(33.3%) of RCA3, including affected two segments in 9 tumors and three segments in 1 tumor. Calcifications were found in 5 aneurysms and 3/5 with thrombosis; six stenotic segments were found. ECHO failed to detect 8 tumors with 2/8 in LAD, 1/8 in LCX and 5/8 in RCA, and those included 4 small aneurysms. The use of 64-slice MDCT angiography proved valuable for monitoring young children with Kawasaki disease. However, further study is necessary to specify the sensitivity and specificity of MDCT in the follow-up.

  20. Imaging of Herniated Discs of the Cervical Spine: Inter-Modality Differences between 64-Slice Multidetector CT and 1.5-T MRI

    Energy Technology Data Exchange (ETDEWEB)

    Yi, Ji Sook; Cha, Jang Gyu [Dept. of Radiology, Soonchunhyang University Bucheon Hospital, Bucheon (Korea, Republic of); Han, Jong Kyu [Dept. of Radiology, Soonchunhyang University Cheonan Hospital, Cheonan (Korea, Republic of); Kim, Hyun Joo [Dept. of Radiology, Soonchunhyang University Seoul Hospital, Seoul (Korea, Republic of)

    2015-08-15

    To assess inter-modality variability when evaluating cervical intervertebral disc herniation using 64-slice multidetector-row computed tomography (MDCT) and magnetic resonance imaging (MRI). Three musculoskeletal radiologists independently reviewed cervical spine 1.5-T MRI and 64-slice MDCT data on C2-3 though C6-7 of 51 patients in the context of intervertebral disc herniation. Interobserver and inter-modality agreements were expressed as unweighted kappa values. Weighted kappa statistics were used to assess the extents of agreement in terms of the number of involved segments (NIS) in disc herniation and epicenter measurements collected using MDCT and MRI. The interobserver agreement rates upon evaluation of disc morphology by the three radiologists were in fair to moderate agreement (k = 0.39-0.53 for MDCT images; k = 0.45-0.56 for MRIs). When the disc morphology was categorized into two and four grades, the inter-modality agreement rates were moderate (k-value, 0.59) and substantial (k-value, 0.66), respectively. The inter-modality agreements for evaluations of the NIS (k-value, 0.78) and the epicenter (k-value, 0.79) were substantial. Also, the interobserver agreements for the NIS (CT; k-value, 0.85 and MRI; k-value, 0.88) and epicenter (CT; k-value, 0.74 and MRI; k-value, 0.70) evaluations by two readers were substantial. MDCT tended to underestimate the extent of herniated disc lesions compared with MRI. Multidetector-row computed tomography and MRI showed a moderate-to-substantial degree of inter-modality agreement for the assessment of herniated cervical discs. MDCT images have a tendency to underestimate the anterior/posterior extent of the herniated disc compared with MRI.

  1. Diagnostic Value of 64-Slice Dual-Source CT Coronary Angiography in Patients with Atrial Fibrillation: Comparison with Invasive Coronary Angiography

    International Nuclear Information System (INIS)

    Zhang, Jian Jun; Liu, Tie; Feng, Yue; Wu, Wei Feng; Mou, Cai Yun; Zhai, Li Hao

    2011-01-01

    We wanted to evaluate the image quality and diagnostic value of 64-slice dual-source computed tomography (DSCT) coronary angiography in patients with atrial fibrillation (Afib). The coronary arteries of 22 Afib patients seen on DSCT were classified into 15 segments and the imaging quality (excellent, good, moderate and poor) and significant stenoses (≥ 50%) were evaluated by two radiologists who were blinded to the conventional coronary angiography (CAG) results. The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) for detecting important coronary artery stenosis were calculated. McNemar test was used to determine any significant difference between DSCT and CAG, and Cohen's Kappa statistics were calculated for the intermodality and interobserver agreement. The mean heart rate was 89 ± 8.3 bpm (range: 80-118 bpm). A range from 250 msec to 300 msec within the RR interval was the optimal reconstruction interval for the patients with Afib. The respective overall sensitivity, specificity, PPV and NPV values were 74%, 97%, 81% and 96% for reader 1 and 72%, 98%, 85% and 96% for reader 2. No significant difference between DSCT and CAG was found for detecting a significant stenosis (reader 1, p = 1.0; reader 2, p = 0.727). Cohen's Kappa statistics demonstrated good intermodality and interobserver agreement. 64-slice DSCT coronary angiography provides good image quality in patients with atrial fibrillation without the need for controlling the heart rate. DSCT can be used for ruling out significant stenosis in patients with atrial fibrillation with its high NPV for detecting in important stenosis.

  2. Diagnostic Value of 64-Slice Dual-Source CT Coronary Angiography in Patients with Atrial Fibrillation: Comparison with Invasive Coronary Angiography

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Jian Jun; Liu, Tie; Feng, Yue; Wu, Wei Feng; Mou, Cai Yun; Zhai, Li Hao [Zhejiang Hospital, Hangzhou (China)

    2011-08-15

    We wanted to evaluate the image quality and diagnostic value of 64-slice dual-source computed tomography (DSCT) coronary angiography in patients with atrial fibrillation (Afib). The coronary arteries of 22 Afib patients seen on DSCT were classified into 15 segments and the imaging quality (excellent, good, moderate and poor) and significant stenoses ({>=} 50%) were evaluated by two radiologists who were blinded to the conventional coronary angiography (CAG) results. The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) for detecting important coronary artery stenosis were calculated. McNemar test was used to determine any significant difference between DSCT and CAG, and Cohen's Kappa statistics were calculated for the intermodality and interobserver agreement. The mean heart rate was 89 {+-} 8.3 bpm (range: 80-118 bpm). A range from 250 msec to 300 msec within the RR interval was the optimal reconstruction interval for the patients with Afib. The respective overall sensitivity, specificity, PPV and NPV values were 74%, 97%, 81% and 96% for reader 1 and 72%, 98%, 85% and 96% for reader 2. No significant difference between DSCT and CAG was found for detecting a significant stenosis (reader 1, p = 1.0; reader 2, p = 0.727). Cohen's Kappa statistics demonstrated good intermodality and interobserver agreement. 64-slice DSCT coronary angiography provides good image quality in patients with atrial fibrillation without the need for controlling the heart rate. DSCT can be used for ruling out significant stenosis in patients with atrial fibrillation with its high NPV for detecting in important stenosis.

  3. Three-dimensional echocardiography in various types of heart disease: a comparison study of magnetic resonance imaging and 64-slice computed tomography in a real-world population.

    Science.gov (United States)

    Squeri, Angelo; Censi, Stefano; Reverberi, Claudio; Gaibazzi, Nicola; Baldelli, Marco; Binno, Simone Maurizio; Properzi, Enrico; Bosi, Stefano

    2017-03-01

    Accurate quantification of left ventricular (LV) volumes [end-diastolic volume (EDV) and end-systolic volume (ESV)] and ejection fraction (EF) is of critical importance. The development of real-time three-dimensional echocardiography (RT3DE) has shown better correlation than two-dimensional (2D) echocardiography with magnetic resonance imaging (MRI) measurements. The aim of our study was to assess the accuracy of RT3DE and 64-slice computed tomography (CT) in the evaluation of LV volumes and function using MRI as the reference standard in a real-world population with various types of heart disease with different chamber geometry. The study population consisted of 66 patients referred for cardiac MRI for various pathologies. All patients underwent cardiac MRI, and RT3DE and 64 slices CT were then performed on a subsequent day. The study population was then divided into 5 clinical groups depending on the underlying heart disease. RT3DE volumes correlated well with MRI values (R 2 values: 0.90 for EDV and 0.94 for ESV). RT3DE measurements of EF correlated well with MRI values (R 2  = 0.86). RT3DE measurements resulted in slightly underestimated values of both EDV and ESV, as reflected by biases of -9.18 and -4.50 mL, respectively. Comparison of RT3DE and MRI in various types of cardiomyopathies showed no statistical difference between different LV geometrical patterns. These results confirm that RT3DE has good accuracy in everyday clinical practice and can be of clinical utility in all types of cardiomyopathy independently of LV geometric pattern, LV diameter or wall thickness, taking into account a slight underestimation of LV volumes and EF compared to MRI.

  4. Combined 201Th myocardial scintiscanning and ECG-triggered ventricular scintiscanning for an evaluation of the left ventricular function after myocardial infarction

    International Nuclear Information System (INIS)

    Nuetzel, W.

    1978-01-01

    74 patients in whom old transmural myocardial infarctions had been detected by catheterisation of the heart were examined by 201 Th myocardial scintiscanning and ECG-triggered ventricular scintiscanning. There was a control group of 16 patients where coronary disease was excluded by the catheter examination. The findings of the nuclear methods are compared with those of invasive and non-invasive cardiological diagnostics. Nuclear techniques were more sensitive (95%) than ECG (77%) in detecting old infarctions. In volumina determination, there was a satisfactory correlation with angiography for the telediastolic volume (r = 0.77) and a good correlation for the telesystolic volume (r = 0.84) and the ejection fraction (r = 0.89). (orig./AJ) [de

  5. Bicuspid aortic valves: Diagnostic accuracy of standard axial 64-slice chest CT compared to aortic valve image plane ECG-gated cardiac CT

    Energy Technology Data Exchange (ETDEWEB)

    Murphy, David J., E-mail: david.murphy@st-vincents.ie [Department of Radiology, St Vincent' s University Hospital, Elm Park, Dublin 4 (Ireland); McEvoy, Sinead H., E-mail: s.mcevoy@st-vincents.ie [Department of Radiology, St Vincent' s University Hospital, Elm Park, Dublin 4 (Ireland); Iyengar, Sri, E-mail: sri.iyengar@nhs.net [Department of Radiology, Plymouth Hospitals NHS Trust, Plymouth Devon PL6 8DH (United Kingdom); Feuchtner, Gudrun, E-mail: Gudrun.Feuchtner@i-med.ac.at [Department of Radiology, Innsbruck Medical University, Anichstr. 35, A-6020 Innsbruck (Austria); Cury, Ricardo C., E-mail: r.cury@baptisthealth.net [Department of Radiology, Baptist Cardiac and Vascular Institute, 8900 North Kendall Drive, Miami, FL 33176 (United States); Roobottom, Carl, E-mail: carl.roobottom@nhs.net [Department of Radiology, Plymouth Hospitals NHS Trust, Plymouth Devon PL6 8DH (United Kingdom); Plymouth University Peninsula Schools of Medicine and Dentistry (United Kingdom); Baumueller, Stephan, E-mail: Hatem.Alkadhi@usz.ch [Institute for Diagnostic and Interventional Radiology, University Hospital Zurich, Raemistrasse 100, CH-8091 Zurich (Switzerland); Alkadhi, Hatem, E-mail: stephan.baumueller@usz.ch [Institute for Diagnostic and Interventional Radiology, University Hospital Zurich, Raemistrasse 100, CH-8091 Zurich (Switzerland); Dodd, Jonathan D., E-mail: jonniedodd@gmail.com [Department of Radiology, St Vincent' s University Hospital, Elm Park, Dublin 4 (Ireland)

    2014-08-15

    Objectives: To assess the diagnostic accuracy of standard axial 64-slice chest CT compared to aortic valve image plane ECG-gated cardiac CT for bicuspid aortic valves. Materials and methods: The standard axial chest CT scans of 20 patients with known bicuspid aortic valves were blindly, randomly analyzed for (i) the appearance of the valve cusps, (ii) the largest aortic sinus area, (iii) the longest aortic cusp length, (iv) the thickest aortic valve cusp and (v) valve calcification. A second blinded reader independently analyzed the appearance of the valve cusps. Forty-two age- and sex-matched patients with known tricuspid aortic valves were used as controls. Retrospectively ECG-gated cardiac CT multiphase reconstructions of the aortic valve were used as the gold-standard. Results: Fourteen (21%) scans were scored as unevaluable (7 bicuspid, 7 tricuspid). Of the remainder, there were 13 evaluable bicuspid valves, ten of which showed an aortic valve line sign, while the remaining three showed a normal Mercedes-Benz appearance owing to fused valve cusps. The 35 evaluable tricuspid aortic valves all showed a normal Mercedes-Benz appearance (P = 0.001). Kappa analysis = 0.62 indicating good interobserver agreement for the aortic valve cusp appearance. Aortic sinus areas, aortic cusp lengths and aortic cusp thicknesses of ≥3.8 cm{sup 2}, 3.2 cm and 1.6 mm respectively on standard axial chest CT best distinguished bicuspid from tricuspid aortic valves (P < 0.0001 for all). Of evaluable scans, the sensitivity, specificity, positive and negative predictive values of standard axial chest CT in diagnosing bicuspid aortic valves was 77% (CI 0.54–1.0), 100%, 100% and 70% respectively. Conclusion: The aortic valve is evaluable in approximately 80% of standard chest 64-slice CT scans. Bicuspid aortic valves may be diagnosed on evaluable scans with good diagnostic accuracy. An aortic valve line sign, enlarged aortic sinuses and elongated, thickened valve cusps are specific CT

  6. Multicenter Comparison of Contrast-Enhanced FDG PET/CT and 64-Slice Multi-Detector-Row CT for Initial Staging and Response Evaluation at the End of Treatment in Patients With Lymphoma.

    Science.gov (United States)

    Gómez León, Nieves; Delgado-Bolton, Roberto C; Del Campo Del Val, Lourdes; Cabezas, Beatriz; Arranz, Reyes; García, Marta; Cannata, Jimena; González Ortega, Saturnino; Pérez Sáez, Mª Ángeles; López-Botet, Begoña; Rodríguez-Vigil, Beatriz; Mateo, Marta; Colletti, Patrick M; Rubello, Domenico; Carreras, José L

    2017-08-01

    To compare staging correctness between contrast-enhanced FDG PET/ceCT and 64-slice multi-detector-row CT (ceCT64) for initial staging and response evaluation at the end of treatment (EOT) in patients with Hodgkin lymphoma, diffuse large B cell lymphoma (DLBCL), and follicular lymphoma. This prospective study compared initial staging and response evaluation at EOT. One hundred eighty-one patients were randomly assigned to either ceCT64 or FDG PET/ceCT. A nuclear medicine physician and a radiologist read FDG PET/ceCT scans independently and achieved post hoc consensus, whereas another independent radiologist interpreted ceCT64 separately. The reference standard included all clinical information, all tests, and follow-up. Ethics committees of the participating centers approved the study, and all participants provided written consent. Ninety-one patients were randomized to ceCT64 and 90 to FDG PET/ceCT; 72 had Hodgkin lymphoma, 72 had DLBCL, and 37 had follicular lymphoma. There was excellent correlation between the reference standard and initial staging for both FDG PET/ceCT (κ = 0.96) and ceCT64 (κ = 0.84), although evaluation of the response at EOT was excellent only for FDG PET/ceCT (κ = 0.91). Our study demonstrated satisfactory agreement between FDG PET/ceCT (κ = 0.96) and ceCT64 (κ = 0.84) in initial staging compared with the reference standard (P = 0.16). Response evaluation at EOT with FDG PET/ceCT (κ = 0.91) was superior compared with ceCT64 (κ = 0.307) (P < 0.001).

  7. Evaluation of diffuse large B-cell lymphoma patients with 64-slice multidetector computed tomography versus 18FDG positron emission tomography/computed tomography in initial staging and restaging after treatment.

    Science.gov (United States)

    Gómez León, Nieves; Vega, Gema; Rodríguez-Vigil Junco, Beatriz; Suevos Ballesteros, Carlos

    2018-04-25

    To prospectively compare the accuracy in initial staging and end-of-treatment restaging of diffuse large B-cell lymphoma (DLBCL) between 64-slice multidetector computed tomography (64MDCT) and 18FDG positron emission tomography/computed tomography (18FGD PET/CT) with intravenous contrast injection. Randomised and blind controlled clinical multicentric trial that included biopsy-proven DLBCL patients. Seventy-two patients from five different hospitals in the region of Madrid, Spain, were enrolled in the study between January 2012 and June 2015. Thirty-six were randomly allocated to 18FDG PET/TC and the other 36 to 64MDCT for initial staging and end-of-treatment restaging. A nuclear medicine physician and a radiologist independently analysed 18FDG PET/TC images and reached an agreement post-hoc. 64MDCT images were separately evaluated by a different radiologist. Every set of images was compared to the reference standard that included clinical data, complementary tests and follow-up. The study was approved by participating centres' ethics committees and written informed consent was obtained from all the participants. A good agreement was observed between both diagnostic techniques and the reference standard in initial staging [18FDG PET/CT (k=0.5) and 64MDCT (k=0.6)], although only the 18FDG PET/TC showed a good agreement with the reference standard for the end-of-treatment restaging (k=0.7). In DLBCL, both 18FDG PET/TC and 64MDCT have shown good agreement with the reference standard in initial staging. Nevertheless, 18FDG PET/CT has shown to be superior to 64MDCT in end-of-treatment response assessment. Copyright © 2018 Elsevier España, S.L.U. All rights reserved.

  8. Coronary imaging quality in routine ECG-gated multidetector CT examinations of the entire thorax: preliminary experience with a 64-slice CT system in 133 patients

    International Nuclear Information System (INIS)

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

    2007-01-01

    To evaluate image quality in the assessment of the coronary arteries during routine ECG-gated multidetector CT (MDCT) of the chest. One hundred and thirty three patients in sinus rhythm underwent an ECG-gated CT angiographic examination of the entire chest without β-blockers with a 64-slice CT system. In 127 patients (95%), it was possible to assess the coronary arteries partially or totally; coronary artery imaging failed in six patients (5%), leading to a detailed description of the coronary arteries in 127 patients. Considering ten coronary artery segments per patient, 75% of coronary segments were assessable (948/1270 segments). When the distal segments were excluded from the analysis (i.e., seven coronary segments evaluated per patient), the percentage of assessable segments was 86% (768/889 proximal and mid coronary segments) and reached 93% (474/508) when assessing proximal segments exclusively. The mean number of assessable segments was significantly higher in patients with a heart rate ≤80 bpm (n=95) than in patients with a heart rate >80 bpm (n=38) (p<0.002). Proximal and mid-coronary segments can be adequately assessed during a whole-chest ECG-gated CT angiographic examination without administration of β-blockers in patients with a heart rate below 80 bpm. (orig.)

  9. Safety and efficacy of a drug regimen to control heart rate during 64-slice ECG-gated coronary CTA in children

    International Nuclear Information System (INIS)

    Rigsby, Cynthia K.; Nicholas, Angela C.; deFreitas, R.A.; Leidecker, Christianne; Johanek, Andrew J.; Anley, Peter; Wang, Deli; Uejima, Tetsu

    2010-01-01

    The adult practice for ECG-gated single-source 64-slice coronary CTA (CCTA) includes administering beta-blockers to reduce heart rate. There are limited data on this process in children. To evaluate the safety and efficacy of a drug regimen to decrease heart rate before performing CCTA in children. IV remifentanil and esmolol infusion were chosen to decrease heart rate in 41 children (mean age 6.5 years) while they were under general anesthesia (GA) for CCTA. Drug doses, changes in heart rate and procedural complications were recorded. CCTA image quality was graded on a scale of 1 to 5. The relationships between image quality and heart rate and image quality and age were evaluated. Patient effective radiation doses were calculated. Heart rates were lowered utilizing esmolol (4 children), remifentanil (2 children) or both (35 children); 26 children received nitroglycerin for coronary vasodilation. The mean decrease in heart rate was 26%. There were no major complications. The average image-quality score was 4.4. Higher heart rates were associated with worse image quality (r = 0.67, P < 0.0001). Older age was associated with better image quality (r = 0.66, P < 0.0001). Effective radiation doses were 0.7 to 7.0 mSv. Heart rate reduction for pediatric CCTA can be safely and effectively achieved while yielding high-quality images. (orig.)

  10. Influence of heart rate on image quality of 64-slice spiral computed coronary angiography and optimization on reconstruction of phase window

    International Nuclear Information System (INIS)

    Luo Xuemao; Lan Yong; Li Wei; Long Wansheng; Zhang Chaotong; Zhong Xiangyang; Yi Lan

    2009-01-01

    Objective: To evaluate the influence of heart rate on the image quality of 64-slice spiral computed coronary angiography (MSCTCA) and optimize the image reconstruction window. Methods: According to the heart rate, 86 patients were classified into 5 groups: group A, the heart rate ≤60 beat per minute(BMP); group B,61-70BMP, group C,71-80BMP, and group D>80BMP. The image quality of MSCTCA was scored 5 grades from 1-5 according to heart motion artifact. The influences of heart rate and reconstruction phase on the image quality of MSCTCA were evaluated. Results: Average heart rate was 64.4 ±10.1BMP. Diagnostic image quality (score>3) was attained in 277 of 344 segments at the best reconstruction interval. There was a significant corxelation between average heart rate and image quality, but there was no difference between relative delay (%) reconstruction and absolute delay (ms) reconstruction on the image quality. Conclusion: Reducing average heart rate is beneficial for improving the image quality. (authors)

  11. Diagnostic value of 64-slice spiral computed tomography imaging of the urinary tract during the excretory phase for urinary tract obstruction.

    Science.gov (United States)

    Zhao, De-Li; Jia, Guang-Sheng; Chen, Peng; Liu, Xin-Ding; Shu, Sheng-Jie; Ling, Zai-Sheng; Fan, Ting-Ting; Shen, Xiu-Fen; Zhang, Jin-Ling

    2017-11-01

    The present study aimed to assess the diagnostic value of 64-slice spiral computed tomography (CT) imaging of the urinary tract during the excretory phase for urinary tract obstruction. CT imaging of the urinary tract during the excretory phase was performed in 46 patients that had been diagnosed with urinary tract obstruction by B-mode ultrasound imaging or clinical manifestations. It was demonstrated that out of the 46 patients, 18 had pelvic and ureteral calculi, 12 cases had congenital malformations, 3 had ureteral stricture caused by urinary tract infection and 13 cases had malignant tumors of the urinary tract. The average X-ray dose planned for the standard CT scan of the urinary tract group 1 was 14.11±5.45 mSv, while the actual X-ray dose administered for the CT scan during the excretory phase group 2 was 9.01±4.56 mSv. The difference between the two groups was statistically significant (t=15.36; Purinary tract during the excretory phase has a high diagnostic value for urinary tract obstruction.

  12. Cochlear Implant Electrode Localization Using an Ultra-High Resolution Scan Mode on Conventional 64-Slice and New Generation 192-Slice Multi-Detector Computed Tomography.

    Science.gov (United States)

    Carlson, Matthew L; Leng, Shuai; Diehn, Felix E; Witte, Robert J; Krecke, Karl N; Grimes, Josh; Koeller, Kelly K; Bruesewitz, Michael R; McCollough, Cynthia H; Lane, John I

    2017-08-01

    A new generation 192-slice multi-detector computed tomography (MDCT) clinical scanner provides enhanced image quality and superior electrode localization over conventional MDCT. Currently, accurate and reliable cochlear implant electrode localization using conventional MDCT scanners remains elusive. Eight fresh-frozen cadaveric temporal bones were implanted with full-length cochlear implant electrodes. Specimens were subsequently scanned with conventional 64-slice and new generation 192-slice MDCT scanners utilizing ultra-high resolution modes. Additionally, all specimens were scanned with micro-CT to provide a reference criterion for electrode position. Images were reconstructed according to routine temporal bone clinical protocols. Three neuroradiologists, blinded to scanner type, reviewed images independently to assess resolution of individual electrodes, scalar localization, and severity of image artifact. Serving as the reference standard, micro-CT identified scalar crossover in one specimen; imaging of all remaining cochleae demonstrated complete scala tympani insertions. The 192-slice MDCT scanner exhibited improved resolution of individual electrodes (p implant imaging compared with conventional MDCT. This technology provides important feedback regarding electrode position and course, which may help in future optimization of surgical technique and electrode design.

  13. Volumetric evaluation of dual-energy perfusion CT by the presence of intrapulmonary clots using a 64-slice dual-source CT

    International Nuclear Information System (INIS)

    Okada, Munemasa; Nakashima, Yoshiteru; Kunihiro, Yoshie; Nakao, Sei; Matsunaga, Naofumi; Morikage, Noriyasu; Sano, Yuichi; Suga, Kazuyoshi

    2013-01-01

    Background: Dual-energy perfusion CT (DE p CT) directly represents the iodine distribution in lung parenchyma and low perfusion areas caused by intrapulmonary clots (IPCs) are visualized as low attenuation areas. Purpose: To evaluate if volumetric evaluation of DE p CT can be used as a predictor of right heart strain by the presence of IPCs. Material and Methods: One hundred and ninety-six patients suspected of having acute pulmonary embolism (PE) underwent DE p CT using a 64-slice dual-source CT. DE p CT images were three-dimensionally reconstructed with four threshold ranges: 1-120 HU (V 120 ), 1-15 HU (V 15 ), 1-10 HU (V 10 ), and 1-5 HU (V 5 ). Each relative ratio per V 120 was expressed as the %V 15 , %V 10 , and %V 5 . Volumetric data-sets were compared with D-dimer, pulmonary arterial (PA) pressure, right ventricular (RV) diameter, RV/left ventricular (RV/LV) diameter ratio, PA diameter, and PA/aorta (PA/Ao) diameter ratio. The areas under the ROC curves (AUCs) were examined for their relationship to the presence of IPCs. This study was approved by the local ethics committee. Results: PA pressure and D-dimer were significantly higher in the patients who had IPCs. In the patients with IPCs, V 15 , V 10 , V 5 , %V 15 , %V 10 , and %V 5 were also significantly higher than those without IPC (P = 0.001). %V 5 had a better correlation with D-dimer (r = 0.30, P p CT had a correlation with D-dimer and RV/LV diameter ratio, and the relative ratio of volumetric CT measurements with a lower attenuation threshold might be recommended for the analysis of acute PE

  14. Non-invasive assessment of congenital pulmonary vein stenosis in children using cardiac-non-gated CT with 64-slice technology

    International Nuclear Information System (INIS)

    Ou, Phalla; Marini, Davide; Celermajer, David S.; Agnoletti, Gabriella; Vouhe, Pascal; Sidi, Daniel; Bonnet, Damien; Brunelle, Francis

    2009-01-01

    Background: Management of congenital pulmonary vein stenosis is a diagnostic challenge. Echocardiography may be insufficient and thus cardiac catheterization remains the reference standard in this setting. The aim of the study was to investigate the accuracy of cardiac-non-gated CT using 64-slice technology in detecting congenital pulmonary vein stenosis in children. Materials and methods: CT examinations were consecutively performed from May 2005 to December 2006 in 13 children aged 1.5-12 months (median 5 months) for suspected congenital pulmonary vein stenosis. Cardiac-non-gated CT acquisitions were performed after the peripheral injection of contrast agent. Pulmonary veins were evaluated for their pattern of connectivity from the lung to the left atrium and for the presence of stenosis. CT findings of pulmonary vein stenosis were compared with combined findings available from echocardiography, catheterization and surgery. Results: Pulmonary veins from the right lung (n = 29) and left lung (n = 26) were evaluated as separate structures (N = 55). Of the 55 structures, 32 had surgical and/or catheterization data and 45 had echocardiography for comparison. CT visualized 100% (55/55) of the investigated structures, while echocardiography visualized 82% (45/55). In the 13 subjects CT identified 10 stenotic pulmonary veins. CT confirmed the echocardiography suspicion of pulmonary vein stenosis in 100% (7/7) and established a new diagnosis in 3 other patients. CT agreed with surgery/catheterization in 100% (10/10) of the available comparisons. Conclusion: Cardiac-non-gated CT assessed the pulmonary veins more completely than echocardiography and should be considered as a viable alternative for invasive pulmonary venography for detecting pulmonary vein stenosis in children.

  15. Comparing culprit lesions in ST-segment elevation and non-ST-segment elevation acute coronary syndrome with 64-slice multidetector computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Huang, W.-C. [School of Medicine, National Yang-Ming University, Taipei, Taiwan (China); Cardiovascular Medical Center, Kaohsiung Veterans General Hospital, No. 386, Dar-Chung First Road, Kaohsiung, Taiwan (China)], E-mail: w.c.huang@yahoo.com.tw; Liu, C.-P. [School of Medicine, National Yang-Ming University, Taipei, Taiwan (China); Cardiovascular Medical Center, Kaohsiung Veterans General Hospital, No. 386, Dar-Chung First Road, Kaohsiung, Taiwan (China)], E-mail: cpliu@isca.vghks.gov.tw; Wu, M.-T. [School of Medicine, National Yang-Ming University, Taipei, Taiwan (China); Department of Radiology, Kaohsiung Veterans General Hospital, No. 386, Dar-Chung First Road, Kaohsiung, Taiwan (China)], E-mail: wu.mingting@gmail.com; Mar, G.-Y. [Cardiovascular Medical Center, Kaohsiung Veterans General Hospital, No. 386, Dar-Chung First Road, Kaohsiung, Taiwan (China)], E-mail: gymar@isca.vghks.gov.tw; Lin, S.-K. [Cardiovascular Medical Center, Kaohsiung Veterans General Hospital, No. 386, Dar-Chung First Road, Kaohsiung, Taiwan (China)], E-mail: skyii89@yahoo.com.tw; Hsiao, S.-H. [Cardiovascular Medical Center, Kaohsiung Veterans General Hospital, No. 386, Dar-Chung First Road, Kaohsiung, Taiwan (China)], E-mail: a841120@ms3.hinet.net; Lin, S.-L. [School of Medicine, National Yang-Ming University, Taipei, Taiwan (China); Cardiovascular Medical Center, Kaohsiung Veterans General Hospital, No. 386, Dar-Chung First Road, Kaohsiung, Taiwan (China)], E-mail: sllin@isca.vghks.gov.tw; Chiou, K.-R. [School of Medicine, National Yang-Ming University, Taipei, Taiwan (China); Cardiovascular Medical Center, Kaohsiung Veterans General Hospital, No. 386, Dar-Chung First Road, Kaohsiung, Taiwan (China)], E-mail: krchiou@isca.vghks.gov.tw

    2010-01-15

    Background: Classifying acute coronary syndrome (ACS) as ST elevation ACS (STE-ACS) or non-ST elevation ACS (NSTE-ACS) is critical for clinical prognosis and therapeutic decision-making. Assessing the differences in composition and configuration of culprit lesions between STE-ACS and NSTE-ACS can clarify their pathophysiologic differences. Objective: This study focused on evaluating the ability of 64-slice multidetector computed tomography (MDCT) to investigate these differences in culprit lesions in patients with STE-ACS and NSTE-ACS. Methods: Of 161 ACS cases admitted, 120 who fit study criteria underwent MDCT and conventional coronary angiography. The following MDCT data were analyzed: calcium volume, Agatston calcium scores, plaque area, plaque burden, remodeling index, and plaque density. Results: The MDCT angiography had a good correlation with conventional coronary angiography regarding the stenotic severity of culprit lesions (r = 0.86, p < 0.001). The STE-ACS culprit lesions (n = 54) had significantly higher luminal area stenosis (78.6 {+-} 21.2% vs. 66.7 {+-} 23.9%, p = 0.006), larger plaque burden (0.91 {+-} 0.10 vs. 0.84 {+-} 0.12, p = 0.007) and remodeling index (1.28 {+-} 0.34 vs. 1.16 {+-} 0.22, p = 0.021) than those with NSTE-ACS (n = 66). The percentage of expanding remodeling index (remodeling index >1.05) was significantly higher in the STE-ACS group (81.5% vs. 63.6%, p = 0.031). The patients with STE-ACS had significantly lower MDCT density of culprit lesions than patients with NSTE-ACS (25.8 {+-} 13.9 HU vs. 43.5 {+-} 19.1 HU, p < 0.001). Conclusions: Sixty-four-slice MDCT can accurately evaluate the stenotic severity and composition of culprit lesions in selected patients with either STE-ACS or NSTE-ACS. Culprit lesions in NSTE-ACS patients had significantly lower luminal area stenosis, plaque burden, remodeling index and higher MDCT density, which possibly reflect differences in the composition of vulnerable culprit plaques and thrombi.

  16. Volumetric evaluation of dual-energy perfusion CT by the presence of intrapulmonary clots using a 64-slice dual-source CT

    Energy Technology Data Exchange (ETDEWEB)

    Okada, Munemasa; Nakashima, Yoshiteru; Kunihiro, Yoshie; Nakao, Sei; Matsunaga, Naofumi [Dept. of Radiology, Yamaguchi Univ. Graduate School of Medicine, Yamaguchi (Japan)], e-mail: radokada@yamaguchi-u.ac.jp; Morikage, Noriyasu [Medical Bioregulation Dept. of Organ Regulatory Surgery, Yamaguchi Univ. Graduate School of Medicine, Yamaguchi (Japan); Sano, Yuichi [Dept. of Radiology, Yamaguchi Univ. Hospital, Yamaguchi (Japan); Suga, Kazuyoshi [Dept. of Radiology, St Hills Hospital, Yamaguchi (Japan)

    2013-07-15

    Background: Dual-energy perfusion CT (DE{sub p}CT) directly represents the iodine distribution in lung parenchyma and low perfusion areas caused by intrapulmonary clots (IPCs) are visualized as low attenuation areas. Purpose: To evaluate if volumetric evaluation of DE{sub p}CT can be used as a predictor of right heart strain by the presence of IPCs. Material and Methods: One hundred and ninety-six patients suspected of having acute pulmonary embolism (PE) underwent DE{sub p}CT using a 64-slice dual-source CT. DE{sub p}CT images were three-dimensionally reconstructed with four threshold ranges: 1-120 HU (V{sub 120}), 1-15 HU (V{sub 15}), 1-10 HU (V{sub 10}), and 1-5 HU (V{sub 5}). Each relative ratio per V{sub 120} was expressed as the %V{sub 15}, %V{sub 10}, and %V{sub 5}. Volumetric data-sets were compared with D-dimer, pulmonary arterial (PA) pressure, right ventricular (RV) diameter, RV/left ventricular (RV/LV) diameter ratio, PA diameter, and PA/aorta (PA/Ao) diameter ratio. The areas under the ROC curves (AUCs) were examined for their relationship to the presence of IPCs. This study was approved by the local ethics committee. Results: PA pressure and D-dimer were significantly higher in the patients who had IPCs. In the patients with IPCs, V{sub 15}, V{sub 10}, V{sub 5}, %V{sub 15}, %V{sub 10}, and %V{sub 5} were also significantly higher than those without IPC (P = 0.001). %V{sub 5} had a better correlation with D-dimer (r = 0.30, P < 0.001) and RV/LV diameter ratio (r = 0.27, P < 0.001), and showed a higher AUC (0.73) than the other CT measurements. Conclusion: The volumetric evaluation by DE{sub p}CT had a correlation with D-dimer and RV/LV diameter ratio, and the relative ratio of volumetric CT measurements with a lower attenuation threshold might be recommended for the analysis of acute PE.

  17. Does slice thickness affect diagnostic performance of 64-slice CT coronary angiography in stable and unstable angina patients with a positive calcium score?

    Energy Technology Data Exchange (ETDEWEB)

    Meijs, Matthijs F.L.; Vos, Alexander M. de; Cramer, Maarten J.; Doevendans, Pieter A.; Vries, Jan J.J. de; Rutten, Annemarieke; Budde, Ricardo P.J.; Prokop, Mathias (Dept. of Radiology, Univ. Medical Center Utrecht, Utrecht (Netherlands)), e-mail: m.meijs@umcutrecht.nl; Meijboom, W. Bob; Feyter, Pim J. de (Dept. of Cardiology, Erasmus Medical Center, Rotterdam (Netherlands))

    2010-05-15

    Background: Coronary calcification can lead to over-estimation of the degree of coronary stenosis. Purpose: To evaluate whether thinner reconstruction thickness improves the diagnostic performance of 64-slice CT coronary angiography (CTCA) in angina patients with a positive calcium score. Material and Methods: We selected 20 scans from a clinical study comparing CTCA to conventional coronary angiography (CCA) in stable and unstable angina patients based on a low number of motion artifacts and a positive calcium score. All images were acquired at 64 x 0.625 mm and each CTCA scan was reconstructed at slice thickness/increment 0.67 mm/0.33 mm, 0.9 mm/0.45 mm, and 1.4 mm/0.7 mm. Two reviewers blinded for CCA results independently evaluated the scans for the presence of significant coronary artery disease (CAD) in three randomly composed series, with =2 weeks in between series. The diagnostic performance of CTCA was compared for the different slice thicknesses using a pooled analysis of both reviewers. Significant CAD was defined as >50% diameter narrowing on quantitative CCA. Image noise (standard deviation of CT numbers) was measured in all scans. Inter-observer variability was assessed with kappa. Results: Significant CAD was present in 8% of 304 available segments. Median total Agatston calcium score was 181.8 (interquartile range 34.9-815.6). Sensitivity at 0.67 mm, 0.9 mm, and 1.4 mm slice thickness was 70% (95% confidence interval 57-83%), 74% (62-86%), and 70% (57-83%), respectively. Specificity was 85% (82-88%), 84% (81-87%), and 84% (81-87%), respectively. The positive predictive value was 30 (21-38%), 29 (21-37%), and 28 (20-36%), respectively. The negative predictive value was 97% (95-98%), 97% (96-99%), and 97% (96-99%), respectively. Kappa for inter-observer agreement was 0.56, 0.58, and 0.59. Noise decreased from 32.9 HU at 0.67 mm, to 23.2 HU at 1.4 mm (P<0.001). Conclusion: Diagnostic performance of CTCA in angina patients with a positive calcium score

  18. Combined use of 64-slice computed tomography angiography and gated myocardial perfusion SPECT for the detection of functionally relevant coronary artery stenoses. First results in a clinical setting concerning patients with stable angina

    International Nuclear Information System (INIS)

    Hacker, M.; Hack, N.; Tiling, R.; Jakobs, T.; Nikolaou, K.; Becker, C.; Ziegler, F. von; Knez, A.; Koenig, A.; Klauss, V.

    2007-01-01

    Aim: In patients with stable angina pectoris both morphological and functional information about the coronary artery tree should be present before revascularization therapy is performed. High accuracy was shown for spiral computed tomography (MDCT) angiography acquired with a 64-slice CT scanner compared to invasive coronary angiography (ICA) in detecting obstructive'' coronary artery disease (CAD). Gated myocardial SPECT (MPI) is an established method for the noninvasive assessment of functional significance of coronary stenoses. Aim of the study was to evaluate the combination of 64-slice CT angiography plus MPI in comparison to ICA plus MPI in the detection of hemodynamically relevant coronary artery stenoses in a clinical setting. Patients, methods: 30 patients (63 ± 10.8 years, 23 men) with stable angina (21 with suspected, 9 with known CAD) were investigated. MPI, 64-slice CT angiography and ICA were performed, reversible and fixed perfusion defects were allocated to determining lesions separately for MDCT angiography and ICA. The combination of MDCT angiography plus MPI was compared to the results of ICA plus MPI. Results: Sensitivity, specificity, negative and positive predictive value for the combination of MDCT angiography plus MPI was 85%, 97%, 98% and 79%, respectively, on a vessel-based and 93%, 87%, 93% and 88%, respectively, on a patient-based level. 19 coronary arteries with stenoses =50% in both ICA and MDCT angiography showed no ischemia in MPI. Conclusion: The combination of 64-slice CT angiography and gated myocardial SPECT enabled a comprehensive non-invasive view of the anatomical and functional status of the coronary artery tree. (orig.)

  19. Combined use of 64-slice computed tomography angiography and gated myocardial perfusion SPECT for the detection of functionally relevant coronary artery stenoses. First results in a clinical setting concerning patients with stable angina

    Energy Technology Data Exchange (ETDEWEB)

    Hacker, M.; Hack, N.; Tiling, R. [Klinikum Grosshadern (Germany). Dept. of Nuclear Medicine; Jakobs, T.; Nikolaou, K.; Becker, C. [Klinikum Grosshadern (Germany). Dept. of Clinical Radiology; Ziegler, F. von; Knez, A. [Klinikum Grosshadern (Germany). Dept. of Cardiology; Koenig, A.; Klauss, V. [Medizinische Poliklinik-Innenstadt, Univ. of Munich (Germany). Dept. of Cardiology

    2007-07-01

    Aim: In patients with stable angina pectoris both morphological and functional information about the coronary artery tree should be present before revascularization therapy is performed. High accuracy was shown for spiral computed tomography (MDCT) angiography acquired with a 64-slice CT scanner compared to invasive coronary angiography (ICA) in detecting ''obstructive'' coronary artery disease (CAD). Gated myocardial SPECT (MPI) is an established method for the noninvasive assessment of functional significance of coronary stenoses. Aim of the study was to evaluate the combination of 64-slice CT angiography plus MPI in comparison to ICA plus MPI in the detection of hemodynamically relevant coronary artery stenoses in a clinical setting. Patients, methods: 30 patients (63 {+-} 10.8 years, 23 men) with stable angina (21 with suspected, 9 with known CAD) were investigated. MPI, 64-slice CT angiography and ICA were performed, reversible and fixed perfusion defects were allocated to determining lesions separately for MDCT angiography and ICA. The combination of MDCT angiography plus MPI was compared to the results of ICA plus MPI. Results: Sensitivity, specificity, negative and positive predictive value for the combination of MDCT angiography plus MPI was 85%, 97%, 98% and 79%, respectively, on a vessel-based and 93%, 87%, 93% and 88%, respectively, on a patient-based level. 19 coronary arteries with stenoses =50% in both ICA and MDCT angiography showed no ischemia in MPI. Conclusion: The combination of 64-slice CT angiography and gated myocardial SPECT enabled a comprehensive non-invasive view of the anatomical and functional status of the coronary artery tree. (orig.)

  20. Low-dose ECG-gated 64-slices helical CT angiography of the chest: evaluation of image quality in 105 patients

    International Nuclear Information System (INIS)

    D'Agostino, A.G.; Remy-Jardin, M.; Khalil, C.; Remy, J.; Delannoy-Deken, V.; Duhamel, A.; Flohr, T.

    2006-01-01

    was significantly linked to a low heart rate in affected patients. The overall image quality of CT scans was rated as diagnostic in 94 patients (89.5%) while 11 examinations (10.5%) were found to be partially nondiagnostic owing to the cyclic presence of severe interpolation artefacts, which can be compensated for by additional reconstructions at a different temporal window. In these cases, interpolation artefacts could have been avoided by reducing the pitch from 0.3 to 0.2 at the expense of increased patient dose. Low-dose ECG-gated CT angiograms of the chest can be obtained in routine clinical practice with 64-slice CT technology without altering the diagnostic value of CT scans. (orig.)

  1. Detection of Airway Anomalies in?Pediatric?Patients with Cardiovascular Anomalies with Low Dose Prospective ECG-Gated Dual-Source CT

    OpenAIRE

    Jiao, Hui; Xu, Zhuodong; Wu, Lebin; Cheng, Zhaoping; Ji, Xiaopeng; Zhong, Hai; Meng, Chen

    2013-01-01

    OBJECTIVES: To assess the feasibility of low-dose prospective ECG-gated dual-source CT (DSCT) in detecting airway anomalies in pediatric patients with cardiovascular anomalies compared with flexible tracheobronchoscopy (FTB). METHODS: 33 pediatrics with respiratory symptoms who had been revealed cardiovascular anomalies by transthoracic echocardiography underwent FTB and contrast material-enhanced prospective ECG-triggering CT were enrolled. The study was approved by our institution review bo...

  2. Prospectively ECG-triggered high-pitch coronary angiography with third-generation dual-source CT at 70 kVp tube voltage: feasibility, image quality, radiation dose, and effect of iterative reconstruction.

    Science.gov (United States)

    Hell, Michaela M; Bittner, Daniel; Schuhbaeck, Annika; Muschiol, Gerd; Brand, Michael; Lell, Michael; Uder, Michael; Achenbach, Stephan; Marwan, Mohamed

    2014-01-01

    Low tube voltage reduces radiation exposure in coronary CT angiography (CTA). Using 70 kVp tube potential has so far not been possible because CT systems were unable to provide sufficiently high tube current with low voltage. We evaluated feasibility, image quality (IQ), and radiation dose of coronary CTA using a third-generation dual-source CT system capable of producing 450 mAs tube current at 70 kVp tube voltage. Coronary CTA was performed in 26 consecutive patients with suspected coronary artery disease, selected for body weight Image noise was lower in IR vs FBP (60 ± 10 HU vs 74 ± 8 HU; P < .001). In patients <100 kg and with a regular heart rate <60 beats/min, third-generation dual-source CT using high-pitch spiral acquisition and 70 kVp tube voltage is feasible and provides both robust IQ and very low radiation exposure. Copyright © 2014 Society of Cardiovascular Computed Tomography. Published by Elsevier Inc. All rights reserved.

  3. Assessment of the right ventricular function in patients with chronic obstructive pulmonary disease and cor pulmonale using cardiac 64-slice spiral CT comparing with 1.7 T MRI

    International Nuclear Information System (INIS)

    Gao Yan; Li Kuncheng; Du Xiangying; Liang Lei; Cao Lizhen; Li Yan; Zhao Shen; Guo Ying

    2009-01-01

    Objective: To assess the right ventricular function in patients with moderate to severe chronic obstructive pulmonary disease (COPD) and eor pulmonale using cardiac 64 MSCT comparing with MRI. Methods: Forty-six patients with COPD determined by pulmonary function test (PFT) were prospectively studied. According to the Global Initiative for COPD classification, the COPD patients were divided into three groups depending on the severity of the disease: mild COPD (16 cases), moderate COPD (16 cases) and severe COPD (14 cases). Twenty age-matched subjects were included as the controls. The RV function was assessed by 64-MSCT and 1.5 T cardiac MRI in all four groups. Pearson correlation analysis was used to evaluate the relationship between the right ventricular ejection fraction (RVEF), myocardial mass (MM) and the PFT results in COPD patients. AP value of less than 0.05 was considered statistically significant. End-diastolic volume (EDV), end-systolic volume (ESV), RVEF and MM on MSCT were compared with that on MRI using Pearson correlation analysis. Bland-Airman plot was used to evaluate the correlation between MSCT and MRI. Results: The RVEF was (51.6 ± 5.6)% in mild COPD, (49.8 ± 6.0)% in moderate COPD, (39.4 ± 7.2)% in severe COPD, and (53 ± 5.9)% in controls, respectively. The MM was (44.5 ± 5.4) g in mild COPD, (49.6 ± 5.0) g in moderate COPD, (57.1 ± 3.4) g in severe COPD, and (40.8 ± 3.9) g in controls, respectively. The EDV was (139.9 ± 25.0), (130.2 ± 21.2), (107.6 ± 18.4) and (149.2 ± 27.9) ml, the SV was (72.1 ± 16.1), (64.3 ± 11.0), (42.5 ± 16.5) and (77.0 ± 11.7) ml in four groups, respectively. The values of RVEF and RVEDV were significantly lower in severe COPD than that in mild COPD, moderate COPD and controls (F RVEF =143, F RVEDV =38.07, P RVEF = 1.03, F EDV =3.22, F EFV =0.44, F SV =2.77, P>0.05). The MM of the RV was significantly different between controls and the other three groups (F=66.34, P<0.01). All parameters of the RV

  4. Image Quality, Overall Evaluability, and Effective Radiation Dose of Coronary Computed Tomography Angiography With Prospective Electrocardiographic Triggering Plus Intracycle Motion Correction Algorithm in Patients With a Heart Rate Over 65 Beats Per Minute.

    Science.gov (United States)

    Pontone, Gianluca; Muscogiuri, Giuseppe; Baggiano, Andrea; Andreini, Daniele; Guaricci, Andrea I; Guglielmo, Marco; Fazzari, Fabio; Mushtaq, Saima; Conte, Edoardo; Annoni, Andrea; Formenti, Alberto; Mancini, Elisabetta; Verdecchia, Massimo; Fusini, Laura; Bonfanti, Lorenzo; Consiglio, Elisa; Rabbat, Mark G; Bartorelli, Antonio L; Pepi, Mauro

    2018-01-16

    Recently, a new intracycle motion correction algorithm (MCA) was introduced to reduce motion artifacts from heart rate (HR) in coronary computed tomography angiography (cCTA). The aim of the study was to evaluate the image quality, overall evaluability, and effective radiation dose (ED) of cCTA with prospective electrocardiographic (ECG) triggering plus MCA as compared with standard protocol with retrospective ECG triggering in patients with HR≥65 bpm. One hundred consecutive patients (67±10 y) scheduled for cCTA with 65Ethics Committee and a written informed consent was obtained from all patients. Image noise, signal to noise ratio, contrast to noise ratio, Likert image quality score (score 1, nondiagnostic; score 2, adequate; score 3, good; score 4, excellent), overall image evaluability, and ED were measured and compared between the 2 groups. Both vessel-based and patient-based analyses were evaluated. Student test or Wilcoxon test were used to evaluate differences of continuous variables, whereas the χ test was used to study differences with regard to categorical data. A P-value <0.05 was considered statistically significant. cCTA was successfully performed in all patients. In a segment-based model, group 1 compared with group 2 showed a lower rate of overall artifacts (67% vs. 83%; P<0.001) and motion artifacts (49% vs. 66%; P<0.001), resulting in a better Likert image quality score (2.83±1.03 vs. 2.37±1.02; P<0.01) and overall evaluability (85% vs. 75%; P<0.01). Group 1 showed a lower ED as compared with group 2 (3.1±1.9 vs. 11.9±3.3 mSv; P<0.01). MCA and cCTA with prospective ECG-triggering acquisition in patients with high HR improves image quality and overall evaluability compared with cCTA with standard retrospective ECG triggering.

  5. 128-slice Dual-source Computed Tomography Coronary Angiography in Patients with Atrial Fibrillation: Image Quality and Radiation Dose of Prospectively Electrocardiogram-triggered Sequential Scan Compared with Retrospectively Electrocardiogram-gated Spiral Scan.

    Science.gov (United States)

    Lin, Lu; Wang, Yi-Ning; Kong, Ling-Yan; Jin, Zheng-Yu; Lu, Guang-Ming; Zhang, Zhao-Qi; Cao, Jian; Li, Shuo; Song, Lan; Wang, Zhi-Wei; Zhou, Kang; Wang, Ming

    2013-01-01

    Objective To evaluate the image quality (IQ) and radiation dose of 128-slice dual-source computed tomography (DSCT) coronary angiography using prospectively electrocardiogram (ECG)-triggered sequential scan mode compared with ECG-gated spiral scan mode in a population with atrial fibrillation. Methods Thirty-two patients with suspected coronary artery disease and permanent atrial fibrillation referred for a second-generation 128-slice DSCT coronary angiography were included in the prospective study. Of them, 17 patients (sequential group) were randomly selected to use a prospectively ECG-triggered sequential scan, while the other 15 patients (spiral group) used a retrospectively ECG-gated spiral scan. The IQ was assessed by two readers independently, using a four-point grading scale from excel-lent (grade 1) to non-assessable (grade 4), based on the American Heart Association 15-segment model. IQ of each segment and effective dose of each patient were compared between the two groups. Results The mean heart rate (HR) of the sequential group was 96±27 beats per minute (bpm) with a variation range of 73±25 bpm, while the mean HR of the spiral group was 86±22 bpm with a variationrange of 65±24 bpm. Both of the mean HR (t=1.91, P=0.243) and HR variation range (t=0.950, P=0.350) had no significant difference between the two groups. In per-segment analysis, IQ of the sequential group vs. spiral group was rated as excellent (grade 1) in 190/244 (78%) vs. 177/217 (82%) by reader1 and 197/245 (80%) vs. 174/214 (81%) by reader2, as non-assessable (grade 4) in 4/244 (2%) vs. 2/217 (1%) by reader1 and 6/245 (2%) vs. 4/214 (2%) by reader2. Overall averaged IQ per-patient in the sequential and spiral group showed equally good (1.27±0.19 vs. 1.25±0.22, Z=-0.834, P=0.404). The effective radiation dose of the sequential group reduced significantly compared with the spiral group (4.88±1.77 mSv vs. 10.20±3.64 mSv; t=-5.372, P=0.000). Conclusion Compared with retrospectively

  6. Cardiac carcinoid: tricuspid delayed hyperenhancement on cardiac 64-slice multidetector CT and magnetic resonance imaging.

    LENUS (Irish Health Repository)

    Martos, R

    2012-02-01

    INTRODUCTION: Carcinoid heart disease is a rare condition in adults. Its diagnosis can be easily missed in a patient presenting to a primary care setting. We revised the advantages of using coronary multidetector computed tomography (MDCT) and cardiac magnetic resonance imaging (MRI) in diagnosing this condition. MATERIALS AND METHODS: We studied a 65-year-old patient with carcinoid heart disease and right heart failure using transthoracic Doppler-echocardiogram, cardiac MDCT and MRI. Cardiac echocardiogram revealed marked thickening and retraction of the tricuspid leaflets with dilated right atrium and ventricle. Cardiac MDCT and MRI demonstrated fixation and retraction of the tricuspid leaflets with delayed contrast hyperenhancement of the tricuspid annulus. CONCLUSION: This case demonstrates fascinating imaging findings of cardiac carcinoid disease and highlights the increasing utility of contrast-enhanced MRI and cardiac MDCT in the diagnosis of this interesting condition.

  7. Congenital anomalies of coronary arteries: Diagnosis with 64 slice multidetector CT

    Energy Technology Data Exchange (ETDEWEB)

    Tariq, Rukhsana, E-mail: drrukhsanatariq@hotmail.com [Consultant Radiologists, Advanced Radiology Clinic, Behind Hamdard University Hospital, Off M.A. Jinnah Road, Karachi (Pakistan); Kureshi, Shahzad Babar [Consultant Radiologists, Advanced Radiology Clinic, Behind Hamdard University Hospital, Off M.A. Jinnah Road, Karachi (Pakistan); Siddiqui, Usman T. [Medical College, Aga Khan University, Karachi (Pakistan); Ahmed, Rashid [Consultant Radiologists, Advanced Radiology Clinic, Behind Hamdard University Hospital, Off M.A. Jinnah Road, Karachi (Pakistan)

    2012-08-15

    Objective: Congenital coronary artery anomalies are generally incidental, uncommon and asymptomatic. Some can cause severe potentially life threatening symptoms. The common mode of studying the coronary arteries is Conventional Coronary Angiogram. ECG-gated-multidetector CT is a non invasive modality. The objective of our study was to identify rare congenital coronary artery anomalies and discuss their clinical significance. Material and methods: A total number of 900 MDCT coronary angiograms were carried out at our institution between the period of April 2006 and October 2010. Patients with coronary artery anomaly constituted the subject of study. Results: The incidence of anomalous anatomical origin and course of the coronary arteries in our study was 1.55%. Hemodynamical significance was seen in five patients. 3 cases of single coronary artery originating from right coronary sinus were seen. 1 case of anomalous left coronary artery arising from main pulmonary artery was seen. 4 cases of anomalous RCA arising from left aortic cusp, 6 cases of absent LMCA with separate origin of LAD and LCX were seen. Conclusion: Multidetector row CT is a noninvasive modality in cardiac imaging. It provides superior resolution of coronary tree and its variant. No projectional vascular overlap is seen. Various postprocessing techniques outclass catheter angiography imaging. Definition of ostia and proximal course of the coronary arteries by Multidetector CT is better than catheter angiography.

  8. Congenital anomalies of coronary arteries: Diagnosis with 64 slice multidetector CT

    International Nuclear Information System (INIS)

    Tariq, Rukhsana; Kureshi, Shahzad Babar; Siddiqui, Usman T.; Ahmed, Rashid

    2012-01-01

    Objective: Congenital coronary artery anomalies are generally incidental, uncommon and asymptomatic. Some can cause severe potentially life threatening symptoms. The common mode of studying the coronary arteries is Conventional Coronary Angiogram. ECG-gated-multidetector CT is a non invasive modality. The objective of our study was to identify rare congenital coronary artery anomalies and discuss their clinical significance. Material and methods: A total number of 900 MDCT coronary angiograms were carried out at our institution between the period of April 2006 and October 2010. Patients with coronary artery anomaly constituted the subject of study. Results: The incidence of anomalous anatomical origin and course of the coronary arteries in our study was 1.55%. Hemodynamical significance was seen in five patients. 3 cases of single coronary artery originating from right coronary sinus were seen. 1 case of anomalous left coronary artery arising from main pulmonary artery was seen. 4 cases of anomalous RCA arising from left aortic cusp, 6 cases of absent LMCA with separate origin of LAD and LCX were seen. Conclusion: Multidetector row CT is a noninvasive modality in cardiac imaging. It provides superior resolution of coronary tree and its variant. No projectional vascular overlap is seen. Various postprocessing techniques outclass catheter angiography imaging. Definition of ostia and proximal course of the coronary arteries by Multidetector CT is better than catheter angiography.

  9. Reduction of radiation exposure and improvement of image quality with BMI-adapted prospective cardiac computed tomography and iterative reconstruction

    International Nuclear Information System (INIS)

    Hosch, Waldemar; Stiller, Wolfram; Mueller, Dirk; Gitsioudis, Gitsios; Welzel, Johanna; Dadrich, Monika; Buss, Sebastian J.; Giannitsis, Evangelos; Kauczor, Hans U.; Katus, Hugo A.; Korosoglou, Grigorios

    2012-01-01

    Purpose: To assess the impact of body mass index (BMI)-adapted protocols and iterative reconstruction algorithms (iDose) on patient radiation exposure and image quality in patients undergoing prospective ECG-triggered 256-slice coronary computed tomography angiography (CCTA). Methods: Image quality and radiation exposure were systematically analyzed in 100 patients. 60 Patients underwent prospective ECG-triggered CCTA using a non-tailored protocol and served as a ‘control’ group (Group 1: 120 kV, 200 mA s). 40 Consecutive patients with suspected coronary artery disease (CAD) underwent prospective CCTA, using BMI-adapted tube voltage and standard (Group 2: 100/120 kV, 100–200 mA s) versus reduced tube current (Group 3: 100/120 kV, 75–150 mA s). Iterative reconstructions were provided with different iDose levels and were compared to filtered back projection (FBP) reconstructions. Image quality was assessed in consensus of 2 experienced observers and using a 5-grade scale (1 = best to 5 = worse), and signal- and contrast-to-noise ratios (SNR and CNR) were quantified. Results: CCTA was performed without adverse events in all patients (n = 100, heart rate of 47–87 bpm and BMI of 19–38 kg/m 2 ). Patients examined using the non-tailored protocol in Group 1 had the highest radiation exposure (3.2 ± 0.4 mSv), followed by Group 2 (1.7 ± 0.7 mSv) and Group 3 (1.2 ± 0.6 mSv) (radiation savings of 47% and 63%, respectively, p < 0.001). Iterative reconstructions provided increased SNR and CNR, particularly when higher iDose level 5 was applied with Multi-Frequency reconstruction (iDose5 MFR) (14.1 ± 4.6 versus 21.2 ± 7.3 for SNR and 12.0 ± 4.2 versus 18.1 ± 6.6 for CNR, for FBP versus iDose5 MFR, respectively, p < 0.001). The combination of BMI adaptation with iterative reconstruction reduced radiation exposure and simultaneously improved image quality (subjective image quality of 1.4 ± 0.4 versus 1.9 ± 0.5 for Group 2 reconstructed using iDose5 MFR versus

  10. Clinical usefullness of ECG-triggered single photon emission comuter tomography of blood-pool

    International Nuclear Information System (INIS)

    Eilles, Chr.; Boerner, W.; Strauss, P.; Gerhards, W.; Reiners, Ch.

    1982-01-01

    ECT allows direct measurement of the volume of an organ and imaging without disturbing background-superposition. This makes ECT to an useful instrument for ECG-gated blood-pool imaging. Acquisition is made after the injection of 25 mCi Tc-99m HSA with a rotating Anger-Camera-System. ECG-gated imaging is done for each projection; herewith 50-70 cycles per projection are added according to the phase of the heart-cycle. Transversal-Sections of the heart are reconstructed with filtered-back-projection. For each slice a representative cycle, consisting of 10-16 frames, is computed. As shown by our group before a good quality of the reconstructed images can be obtained. Comparison is made with the results of the ECG-gated blood-pool-ECT, the results of the conventional blood-pool-studies and with the results of Laevo-Cardiography. (Author)

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

    International Nuclear Information System (INIS)

    Ketelsen, Dominik; Fenchel, Michael; Thomas, Christoph; Boehringer, Nadine; Tsiflikas, Ilias; Kaempf, Michael; Claussen, Claus D; Heuschmid, Martin; Buchgeister, Markus

    2011-01-01

    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

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

    Energy Technology Data Exchange (ETDEWEB)

    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

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    International Nuclear Information System (INIS)

    Arai, Kosuke; Ishii, Hideki; Amano, Tetasuya

    2010-01-01

    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 mm 3 , 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 mm 3 ), 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)

  15. Evaluation of organ doses and specific k effective dose of 64-slice CT thorax examination using an adult anthropomorphic phantom

    International Nuclear Information System (INIS)

    Hashim, S.; Karim, M.K.A.; Bakar, K.A.; Sabarudin, A.; Chin, A.W; Saripan, M.I.; Bradley, D.A.

    2016-01-01

    The magnitude of radiation dose in computed tomography (CT) depends on the scan acquisition parameters, investigated herein using an anthropomorphic phantom (RANDO®) and thermoluminescence dosimeters (TLD). Specific interest was in the organ doses resulting from CT thorax examination, the specific k coefficient for effective dose estimation for particular protocols also being determined. For measurement of doses representing five main organs (thyroid, lung, liver, esophagus and skin), TLD-100 (LiF:Mg, Ti) were inserted into selected holes in a phantom slab. Five CT thorax protocols were investigated, one routine (R1) and four that were modified protocols (R2 to R5). Organ doses were ranked from greatest to least, found to lie in the order: thyroid>skin>lung>liver>breast. The greatest dose, for thyroid at 25 mGy, was that in use of R1 while the lowest, at 8.8 mGy, was in breast tissue using R3. Effective dose (E) was estimated using three standard methods: the International Commission on Radiological Protection (ICRP)-103 recommendation (E103), the computational phantom CT-EXPO (E(CTEXPO)) method, and the dose-length product (DLP) based approach. E103 k factors were constant for all protocols, ~8% less than that of the universal k factor. Due to inconsistency in tube potential and pitch factor the k factors from CTEXPO were found to vary between 0.015 and 0.010 for protocols R3 and R5. With considerable variation between scan acquisition parameters and organ doses, optimization of practice is necessary in order to reduce patient organ dose. - Highlights: • Using TLD-100 dosimeters and a RANDO phantom 5 CT thorax protocol organ doses were assessed. • The specific k coefficient for effective dose estimation of protocols differed with approach. • Organ dose was observed to decrease in the order: thyroid>skin>lung>liver>breast. • E103 k factors were constant for all protocols, lower by ~8% compared to the universal k factor.

  16. The optimization of low-dose scanning protocols of 64-slice spiral CT in the adult chest: a multicenter study

    International Nuclear Information System (INIS)

    Tang Wei; Huang Yao; Wu Ning

    2011-01-01

    Objective: To compare the image quality of chest low dose CT (LDCT) using automatic exposure control (AEC) and constant current. control (CCC) and explore a more reasonable scanning protocol. Methods: Two hundred and eighty participants were examined with 64 CT scanner at 7 centers in China. All were divided into 4 groups. Two groups underwent LDCT using AEC with standard deviation set at 25 (Al) and 30 (A2) respectively and the tube current ranged from 10 mA to 80 mA. The other two groups underwent LDCT using CCC with tube current set at 40 mA (Cl) and 50 mA (C2) respectively. The axial and MPR images were evaluated by two radiologists who were blinded to the scanning protocols. The radiation dose, noise and the image quality of the 4 groups were compared and analyzed statistically. Differences of radiation dose and noise among groups were determined with variance analysis and t test, image quality with Mann- Whitney test and the consistency of diagnosis with Kappa test. Results: There was a significant lower DLP in AEC group than in CCC group [(82.62±40.31) vs (110.81±18.21) mGy · cm (F=56.88, P 0.05]. The noisy of AEC group was higher than that of CCC group both on lung window (41.50±9.58 vs 40.86±7.03) and mediastinum window (41.19±7.83 vs 40.92±9.89), but there was no significant difference (F lung =0.835, P=0.476, F wediastinum =1.910, P=0.128). The quality score of axial image in AEC group was higher than that in CCC group (superior margin of the brachiocephalic vein level: 4.49± 0.56 vs 4.38±0.64, superior margin of the aortic arch: 4.86±0.23 vs 4.81±0.32, the right superior lobar bronchus Level: 4.87±0.27 vs 4.84±0.22, the right middle lobar bronchus Level: 4.90±0.25 vs 4.88±0.21) except on the right inferior pulmonary vein level (4.92±0.25 vs 4.93±0.17) and superior margin of the left diaphragmatic dome level (4.91±0.27 vs 4.93±0.22) on lung window, but no significant differences (F=0.076-1.748, P>0.05) were observed. A significant higher score in AEC group was observed on mediastinum window compared with CCC group on superior margin of' brachiocephalic vein level (2.57±0.77 vs 2.46±0.59, F=8.459, P 0.05). The MPR image quality of AEC group was better than that of CCC group both on lung window and mediastinum window (Z lung =-2.258, Z mediastinum =-1.330, P>0.05). For all participants including the underweighted group, the normal group and the overweighted group, the image quality of Al group was better than that of A2 group without significant differences (the underweighted group: Z lung = 0.000, P=1.000, Z mediastinum =0.000, P=1.000; the normal group: Z lung =-0.062, P= 0.950, Z mediastinum =-0.746, P=0.456; the overweighted group: Z lung =-1.177, P=0.239, Z mediastinum =-1.715, P=0.144) both on lung and mediastinum windows, and for the higher BMI participants, a better image quality was obtained in Al group than in A2 group on the mediastinum window (Z=-1.715, P=0.144). Conclusions: The total radiation exposure dose of AEC group is significantly lower than that of CCC group, but no statistical significant differences are observed between both groups in image quality and noise level. The AEC technique is highly recommended in thoracic LDCT scan for screening program, and the SD25 (SD value =25) scan protocol is suggested for higher BMI population while the SD30 (SD value = 30) scan protocol for lower BMI population. (authors)

  17. Left coronary to right ventricle fistula in a child: management strategy based on cardiac-gated 64-slice CT

    Energy Technology Data Exchange (ETDEWEB)

    Marini, Davide; Agnoletti, Gabriella; Bonnet, Damien [University Rene Descartes-Paris V, Department of Paediatric Cardiology, Hopital Necker-Enfants Malades, AP-HP, Paris (France); Brunelle, Francis; Ou, Phalla [University Rene Descartes-Paris V, Department of Paediatric Radiology, Hopital Necker-Enfants Malades, AP-HP, Paris (France)

    2008-03-15

    Congenital coronary fistulae are a diagnostic challenge. A prerequisite for best management is accurate anatomical evaluation, traditionally provided by invasive catheter angiography. Multislice CT (MSCT) is an emerging noninvasive technique for coronary artery evaluation. We present a 3-year-old boy and highlight the clinical usefulness of new-generation MSCT to study coronary artery fistulae in children. Multiplanar and 3-D reconstruction offer invaluable information to plan the best therapeutic strategy in this setting. We provide evidence for the expanding clinical role of MSCT for coronary artery imaging in children. (orig.)

  18. Left coronary to right ventricle fistula in a child: management strategy based on cardiac-gated 64-slice CT

    International Nuclear Information System (INIS)

    Marini, Davide; Agnoletti, Gabriella; Bonnet, Damien; Brunelle, Francis; Ou, Phalla

    2008-01-01

    Congenital coronary fistulae are a diagnostic challenge. A prerequisite for best management is accurate anatomical evaluation, traditionally provided by invasive catheter angiography. Multislice CT (MSCT) is an emerging noninvasive technique for coronary artery evaluation. We present a 3-year-old boy and highlight the clinical usefulness of new-generation MSCT to study coronary artery fistulae in children. Multiplanar and 3-D reconstruction offer invaluable information to plan the best therapeutic strategy in this setting. We provide evidence for the expanding clinical role of MSCT for coronary artery imaging in children. (orig.)

  19. Experimental measurement of the scatter fraction in skull and body CT for teams 64- slice computed tomography

    International Nuclear Information System (INIS)

    Sanchez, G.; Haro, G.; Herrador, M.

    2011-01-01

    Different formalisms for the calculation of shielding in Cf equipment, the proposed document 147 of NCRP are widely accepted. Of the three methods mentioned in the protocol, two involve the use of two independent factor a of equipment, called scatter fraction CT in skull and body. Interestingly, the experimental measurement of the same, especially in those models following the publication of the document, which are also coincides with the highest number of detector channels and overall a greater radiation beam in the z axis.

  20. Comparison of the image quality between volumetric and conventional high-resolution CT with 64-slice row CT

    International Nuclear Information System (INIS)

    Gao Yanli; Zhang Lei; Zhao Xia; Ma Min; Zhai Renyou

    2008-01-01

    Objective: To compare the image quality between volumetric high-resolution CT (VHRCT) and conventional high-resolution CT (CHRCT), and investigate the feasibility of VHRCT. Methods: Catphan 412 phantom was scanned with protocols of CHRCT and VHRCT on a set of GE Lightspeed VCT. The spatial-resolution (LP/cm), noise (standard deviation in an ROI) and radiation close (CTDI) were recorded for each CT scan. Difference of noise between CHRCT and VHRCT were evaluated by paired t test. In clinical study, 32 patients were scanned with VHRCT and CHRCT protocols. The image quality of CHRCT and VHRCT was rated and compared. The quality difference between CHRCT and VHRCT was assessed by Wilcoxon paired signed rank sum test. Results: In phantom study, the in-plane spatial-resolution of both VHRCT and CHRCT was 11 LP/cm for axial images and 12 LP/cm for coronal reformatted images. The noise of VHRCT and CHRCT was (69.18±2.77)HU and (54.62±2.12) HU respectively (t=-15.929, P 0.05). The quality assessment scores of VHRCT coronal reformatted images and CHRCT coronal reformatted images were 3.05 and 1.88 respectively with significant difference (Z= -5.088, P<0.01). Conclusion: The image quality of VHRCT cross-sectional image is similar to that of CHRCT. Multiplanar images with high resolution of VHRCT are recommended. The radiation dose of VHRCT remains to be optimized. (authors)

  1. Interobserver agreement in fusion status assessment after instrumental desis of the lower lumbar spine using 64-slice multidetector computed tomography

    DEFF Research Database (Denmark)

    Laoutliev, Borislav; Havsteen, Inger; Bech, Birthe Højlund

    2012-01-01

    Persistent lower back pain after instrumental posterolateral desis may arise from incomplete fusion. We investigate the impact of experience on interobserver agreement in fusion estimation.......Persistent lower back pain after instrumental posterolateral desis may arise from incomplete fusion. We investigate the impact of experience on interobserver agreement in fusion estimation....

  2. Three-dimensional surface reconstruction imaging for evaluation of congenital heart disease from ECG-triggered MR images

    International Nuclear Information System (INIS)

    Vannier, M.W.; Laschinger, J.; Knapp, R.H.; Gutierrez, F.R.; Gronnemeyer, S.A.

    1987-01-01

    Three-dimensional surface reconstruction images of the heart and great vessels were produced from contiguous sequences of electrocardiographically triggered MR images in 25 patients with congenital heart disease and in three healthy subjects. The imaging data were semiautomatically processed to separate the epicardial and endocardial surfaces and to define the outline of the enclosed blood volumes on a section by section basis. Images were obtained at 5-mm intervals in patients aged 3 months to 30 years with anomalies of the great vessels, tetralogy of Fallot, septal defects, pulmonary atresia, and other congenital heart malformations. The results were used to facilitate the surgical treatment of these patients and were compared with echocardiographic and cineradiographic studies, and with surgical findings or pathologic specimens. These surface reconstruction images were useful for communicating the results of diagnostic examinations to cardiac surgeons, for sizing and location of intracardiac defects, for imaging the pulmonary venous drainage, and for assessing regional and global function

  3. Long-term prognostic performance of low-dose coronary computed tomography angiography with prospective electrocardiogram triggering

    Energy Technology Data Exchange (ETDEWEB)

    Clerc, Olivier F.; Kaufmann, Basil P.; Possner, Mathias; Liga, Riccardo; Vontobel, Jan; Mikulicic, Fran; Graeni, Christoph; Benz, Dominik C.; Fuchs, Tobias A.; Stehli, Julia; Pazhenkottil, Aju P.; Gaemperli, Oliver; Kaufmann, Philipp A.; Buechel, Ronny R. [University Hospital Zurich, Cardiac Imaging, Department of Nuclear Medicine, Zurich (Switzerland)

    2017-11-15

    To assess long-term prognosis after low-dose 64-slice coronary computed tomography angiography (CCTA) using prospective electrocardiogram-triggering. We included 434 consecutive patients with suspected or known coronary artery disease referred for low-dose CCTA. Patients were classified as normal, with non-obstructive or obstructive lesions, or previously revascularized. Coronary artery calcium score (CACS) was assessed in 223 patients. Follow-up was obtained regarding major adverse cardiac events (MACE): cardiac death, myocardial infarction and elective revascularization. We performed Kaplan-Meier analysis and Cox regressions. Mean effective radiation dose was 1.7 ± 0.6 mSv. At baseline, 38% of patients had normal arteries, 21% non-obstructive lesions, 32% obstructive stenosis and 8% were revascularized. Twenty-nine patients (7%) were lost to follow-up. After a median follow-up of 6.1 ± 0.6 years, MACE occurred in 0% of patients with normal arteries, 6% with non-obstructive lesions, 30% with obstructive stenosis and 39% of those revascularized. MACE occurrence increased with increasing CACS (P < 0.001), but 4% of patients with CACS = 0 experienced MACE. Multivariate Cox regression identified obstructive stenosis, lesion burden in CCTA and CACS as independent MACE predictors (P ≤ 0.001). Low-dose CCTA with prospective electrocardiogram-triggering has an excellent long-term prognostic performance with a warranty period >6 years for patients with normal coronary arteries. (orig.)

  4. Long-term prognostic performance of low-dose coronary computed tomography angiography with prospective electrocardiogram triggering

    International Nuclear Information System (INIS)

    Clerc, Olivier F.; Kaufmann, Basil P.; Possner, Mathias; Liga, Riccardo; Vontobel, Jan; Mikulicic, Fran; Graeni, Christoph; Benz, Dominik C.; Fuchs, Tobias A.; Stehli, Julia; Pazhenkottil, Aju P.; Gaemperli, Oliver; Kaufmann, Philipp A.; Buechel, Ronny R.

    2017-01-01

    To assess long-term prognosis after low-dose 64-slice coronary computed tomography angiography (CCTA) using prospective electrocardiogram-triggering. We included 434 consecutive patients with suspected or known coronary artery disease referred for low-dose CCTA. Patients were classified as normal, with non-obstructive or obstructive lesions, or previously revascularized. Coronary artery calcium score (CACS) was assessed in 223 patients. Follow-up was obtained regarding major adverse cardiac events (MACE): cardiac death, myocardial infarction and elective revascularization. We performed Kaplan-Meier analysis and Cox regressions. Mean effective radiation dose was 1.7 ± 0.6 mSv. At baseline, 38% of patients had normal arteries, 21% non-obstructive lesions, 32% obstructive stenosis and 8% were revascularized. Twenty-nine patients (7%) were lost to follow-up. After a median follow-up of 6.1 ± 0.6 years, MACE occurred in 0% of patients with normal arteries, 6% with non-obstructive lesions, 30% with obstructive stenosis and 39% of those revascularized. MACE occurrence increased with increasing CACS (P < 0.001), but 4% of patients with CACS = 0 experienced MACE. Multivariate Cox regression identified obstructive stenosis, lesion burden in CCTA and CACS as independent MACE predictors (P ≤ 0.001). Low-dose CCTA with prospective electrocardiogram-triggering has an excellent long-term prognostic performance with a warranty period >6 years for patients with normal coronary arteries. (orig.)

  5. Reduction of the estimated radiation dose and associated patient risk with prospective ECG-gated 256-slice CT coronary angiography

    International Nuclear Information System (INIS)

    Efstathopoulos, E P; Kelekis, N L; Pantos, I; Brountzos, E; Argentos, S; Grebac, J; Ziaka, D; Seimenis, I; Katritsis, D G

    2009-01-01

    Computed tomography (CT) coronary angiography has been widely used since the introduction of 64-slice scanners and dual-source CT technology, but high radiation doses have been reported. Prospective ECG-gating using a 'step-and-shoot' axial scanning protocol has been shown to reduce radiation exposure effectively while maintaining diagnostic accuracy. 256-slice scanners with 80 mm detector coverage have been currently introduced into practice, but their impact on radiation exposure has not been adequately studied. The aim of this study was to assess radiation doses associated with CT coronary angiography using a 256-slice CT scanner. Radiation doses were estimated for 25 patients scanned with either prospective or retrospective ECG-gating. Image quality was assessed objectively in terms of mean CT attenuation at selected regions of interest on axial coronary images and subjectively by coronary segment quality scoring. It was found that radiation doses associated with prospective ECG-gating were significantly lower than retrospective ECG-gating (3.2 ± 0.6 mSv versus 13.4 ± 2.7 mSv). Consequently, the radiogenic fatal cancer risk for the patient is much lower with prospective gating (0.0176% versus 0.0737%). No statistically significant differences in image quality were observed between the two scanning protocols for both objective and subjective quality assessments. Therefore, prospective ECG-gating using a 'step-and-shoot' protocol that covers the cardiac anatomy in two axial acquisitions effectively reduces radiation doses in 256-slice CT coronary angiography without compromising image quality.

  6. PROspective Multicenter Imaging Study for Evaluation of chest pain: rationale and design of the PROMISE trial.

    Science.gov (United States)

    Douglas, Pamela S; Hoffmann, Udo; Lee, Kerry L; Mark, Daniel B; Al-Khalidi, Hussein R; Anstrom, Kevin; Dolor, Rowena J; Kosinski, Andrzej; Krucoff, Mitchell W; Mudrick, Daniel W; Patel, Manesh R; Picard, Michael H; Udelson, James E; Velazquez, Eric J; Cooper, Lawton

    2014-06-01

    Suspected coronary artery disease (CAD) is one of the most common, potentially life-threatening diagnostic problems clinicians encounter. However, no large outcome-based randomized trials have been performed to guide the selection of diagnostic strategies for these patients. The PROMISE study is a prospective, randomized trial comparing the effectiveness of 2 initial diagnostic strategies in patients with symptoms suspicious for CAD. Patients are randomized to either (1) functional testing (exercise electrocardiogram, stress nuclear imaging, or stress echocardiogram) or (2) anatomical testing with ≥64-slice multidetector coronary computed tomographic angiography. Tests are interpreted locally in real time by subspecialty certified physicians, and all subsequent care decisions are made by the clinical care team. Sites are provided results of central core laboratory quality and completeness assessment. All subjects are followed up for ≥1 year. The primary end point is the time to occurrence of the composite of death, myocardial infarction, major procedural complications (stroke, major bleeding, anaphylaxis, and renal failure), or hospitalization for unstable angina. More than 10,000 symptomatic subjects were randomized in 3.2 years at 193 US and Canadian cardiology, radiology, primary care, urgent care, and anesthesiology sites. Multispecialty community practice enrollment into a large pragmatic trial of diagnostic testing strategies is both feasible and efficient. The PROMISE trial will compare the clinical effectiveness of an initial strategy of functional testing against an initial strategy of anatomical testing in symptomatic patients with suspected CAD. Quality of life, resource use, cost-effectiveness, and radiation exposure will be assessed. Copyright © 2014 Mosby, Inc. All rights reserved.

  7. Quantitative analysis of orthopedic metal artefact reduction in 64-slice computed tomography scans in large head metal-on-metal total hip replacement, a phantom study

    NARCIS (Netherlands)

    Boomsma, Martijn F.; Warringa, Niek; Edens, Mireille A.; Mueller, Dirk; Ettema, Harmen B.; Verheyen, Cees C. P. M.; Maas, Mario

    2016-01-01

    Purpose: Quantification of the effect of O-MAR on decreasing metal artefacts caused by large head metal on metal total hip arthroplasty (MoM THA) in a dedicated phantom setup of the hip. Background: Pathological reactions of the hip capsule on Computed tomography (CT) can be difficult to diagnose

  8. Comparison of determinations of left atrial volume by the biplane area-length and Simpson's methods using 64-slice computed tomography

    International Nuclear Information System (INIS)

    Takagi, Yasuhiro; Ehara, Shoichi; Okuyama, Takuhiro

    2009-01-01

    There is increasing evidence that left atrial (LA) size is an important predictor of adverse cardiovascular outcomes such as atrial fibrillation, stroke, and congestive heart failure. The aim of this study was to determine whether there is a difference in results of quantification of LA volume by the area-length and Simpson's methods using multislice computed tomography (MSCT). The study population consisted of 51 patients with sinus rhythm (sinus group) and 20 patients with atrial fibrillation (af group) clinically indicated for MSCT angiography for evaluation of coronary arteries. Maximum LA volume, obtained at end-systole from the phase immediately preceding mitral valve opening, was measured using the area-length and Simpson's methods. In the sinus group, the mean LA volumes, indexed to body surface area, were 48.4±17.9 ml/m 2 with the area-length method and 48.3±17.0 ml/m 2 with the Simpson's method. In the af group, the mean indexed LA volumes with the area-length method and the Simposon's method were 91.5±47.5 ml/m 2 and 90.3±45.9 ml/m 2 , respectively. LA volumes calculated by the area-length method exhibited a strong linear relationship and agreement with those calculated using Simpson's method in both the groups (sinus group: r=0.99, P<0.0001, af group: r=0.99, P<0.0001). The area-length method is a simple and reproducible means of assessment of LA volume. Standardization of LA volume assessment using MSCT is important for serial follow-up and meaningful communication of results of testing among institutions and physicians. (author)

  9. Comparison of findings of spontaneous splenorenal shunt in color Doppler sonography with multislice CT scan (64 slices) in liver transplant candidates

    Energy Technology Data Exchange (ETDEWEB)

    Bagheri, Mohammadhadi, E-mail: Bagherimh@gmail.com [Department of Radiology, Shiraz University of Medical Sciences, Namazi Hospital, Shiraz (Iran, Islamic Republic of); Hajati, Azadeh, E-mail: azadeh.hajati@gmail.com [Department of Radiology, Shiraz University of Medical Sciences, Namazi Hospital, Shiraz (Iran, Islamic Republic of); Hosseini, Mohammadkazem, E-mail: hosseiniaslm@sums.ac.ir [Department of Radiology, Shiraz University of Medical Sciences, Namazi Hospital, Shiraz (Iran, Islamic Republic of); Ostad, Seyed Pouria, E-mail: Pouria.Ostad@gmail.com [Department of Radiology, Shiraz University of Medical Sciences, Namazi Hospital, Shiraz (Iran, Islamic Republic of)

    2012-09-15

    Background: Liver transplantation is the only definite treatment for end stage liver disease and it has high costs for the medical system so decreasing its complication and increasing its effectiveness is crucial. One of the factors that affect liver transplantation is the presence of spontaneous splenorenal shunt. Its diagnosis is mainly overlooked in pre-liver transplant patients. Main modality for its diagnosis is multislice CT scan however this is more expensive than sonography. Also, it exposes the patients to ionizing radiation. Considering the advantages of color Doppler ultrasound, studies to determine the sensitivity and specificity for detection of spontaneous splenorenal shunt is essential. Materials and methods: In our study 70 cirrhotic patients who were referred by liver transplant surgeons for evaluation of abdomen by CT and sonograhy were assessed for presence of spontaneous splenorenal shunt, left adrenal varix and left renal vein diameter and velocity and sensitivity and specificity of both modalities were checked. Patients in whom left renal vein could not evaluated by sonography and patients with splenectomy and nutcracker syndrome were excluded. Results: In the point of 10 mm diameter of left renal vein in CT scan there was 78.6% sensitivity and 67.9% specificity for the presence of spontaneous splenorenal shunt. Left adrenal varix in CT had sensitivity of 71.4%, specificity of 100%, and positive predictive value of 100% and negative predictive value of 70% and varix below spleen in CT had sensitivity of 54.8%, specificity of 96.4%, and positive predictive value of 95.8% and negative predictive value of 58.7% for the presence of spontaneous splenorenal shunt. In the point of 8 mm diameter of left renal vein in sonography there was 66.7% sensitivity and 85.7% specificity for the presence of spontaneous splenorenal shunt. For the velocity of more than 35 cm/s of left renal vein in sonography there was 61.9% sensitivity and 82.1% specificity for the presence of spontaneous splenorenal shunt. Left adrenal varix in sonography had sensitivity of 45.2%, specificity of 96.4%, positive predictive value of 95% and negative predictive value of 54% for the presence of spontaneous splenorenal shunt. Conclusion: There was moderate agreement between CT scan and sonography for detection of spontaneous splenorenal shunt. CT scan is choice for detection of SSRS but sonography is somehow useful. It means that if sonograhy is positive it is sufficient, if negative, then CT should be performed. This is due to low sensitivity of sonography.

  10. Feasibility of epicardial adipose tissue quantification in non-ECG-gated low-radiation-dose CT: comparison with prospectively ECG-gated cardiac CT

    Energy Technology Data Exchange (ETDEWEB)

    Simon-Yarza, Isabel; Viteri-Ramirez, Guillermo; Saiz-Mendiguren, Ramon; Slon-Roblero, Pedro J.; Paramo, Maria [Dept. of Radiology, Clinica Univ. de Navarra, Pamplona (Spain); Bastarrika, Gorka [Dept. of Radiology, Clinica Univ. de Navarra, Pamplona (Spain); Cardiac Imaging Unit, Clinica Univ. de Navarra, Pamplona (Spain)], e-mail: bastarrika@unav.es

    2012-06-15

    Background: Epicardial adipose tissue (EAT) is an important indicator of cardiovascular risk. This parameter is generally assessed on ECG-gated computed tomography (CT) images. Purpose: To evaluate feasibility and reliability of EAT quantification on non-gated thoracic low-radiation-dose CT examinations with respect to prospectively ECG-gated cardiac CT acquisition. Material and Methods: Sixty consecutive asymptomatic smokers (47 men; mean age 64 {+-} 9.8 years) underwent low-dose CT of the chest and prospectively ECG-gated cardiac CT acquisitions (64-slice dual-source CT). The two examinations were reconstructed with the same range, field of view, slice thickness, and convolution algorithm. Two independent observers blindly quantified EAT volume using commercially available software. Data were compared with paired sample Student t-test, concordance correlation coefficients (CCC), and Bland-Altman plots. Results: No statistically significant difference was observed for EAT volume quantification with low-dose-CT (141.7 {+-} 58.3 mL) with respect to ECG-gated CT (142.7 {+-} 57.9 mL). Estimation of CCC showed almost perfect concordance between the two techniques for EAT-volume assessment (CCC, 0.99; mean difference, 0.98 {+-} 5.1 mL). Inter-observer agreement for EAT volume estimation was CCC: 0.96 for low-dose-CT examinations and 0.95 for ECG-gated CT. Conclusion: Non-gated low-dose CT allows quantifying EAT with almost the same concordance and reliability as using dedicated prospectively ECG-gated cardiac CT acquisition protocols.

  11. Feasibility of epicardial adipose tissue quantification in non-ECG-gated low-radiation-dose CT: comparison with prospectively ECG-gated cardiac CT

    International Nuclear Information System (INIS)

    Simon-Yarza, Isabel; Viteri-Ramirez, Guillermo; Saiz-Mendiguren, Ramon; Slon-Roblero, Pedro J.; Paramo, Maria; Bastarrika, Gorka

    2012-01-01

    Background: Epicardial adipose tissue (EAT) is an important indicator of cardiovascular risk. This parameter is generally assessed on ECG-gated computed tomography (CT) images. Purpose: To evaluate feasibility and reliability of EAT quantification on non-gated thoracic low-radiation-dose CT examinations with respect to prospectively ECG-gated cardiac CT acquisition. Material and Methods: Sixty consecutive asymptomatic smokers (47 men; mean age 64 ± 9.8 years) underwent low-dose CT of the chest and prospectively ECG-gated cardiac CT acquisitions (64-slice dual-source CT). The two examinations were reconstructed with the same range, field of view, slice thickness, and convolution algorithm. Two independent observers blindly quantified EAT volume using commercially available software. Data were compared with paired sample Student t-test, concordance correlation coefficients (CCC), and Bland-Altman plots. Results: No statistically significant difference was observed for EAT volume quantification with low-dose-CT (141.7 ± 58.3 mL) with respect to ECG-gated CT (142.7 ± 57.9 mL). Estimation of CCC showed almost perfect concordance between the two techniques for EAT-volume assessment (CCC, 0.99; mean difference, 0.98 ± 5.1 mL). Inter-observer agreement for EAT volume estimation was CCC: 0.96 for low-dose-CT examinations and 0.95 for ECG-gated CT. Conclusion: Non-gated low-dose CT allows quantifying EAT with almost the same concordance and reliability as using dedicated prospectively ECG-gated cardiac CT acquisition protocols

  12. Korea prospects

    International Nuclear Information System (INIS)

    Wyman, V.

    1990-01-01

    Contacts between the South Korean nuclear industry and a combined United Kingdom mission representing AEA Technology and British Nuclear Fuels Limited (BNFL) are reported. Prospects for entering the Korean market in two areas are perceived. The first is waste management and the second is the Safe Integral Reactor (SIR), an advanced pressurized water reactor design. AEA Technology and three collaborators have been promoting SIR as an inherently safe reactor design. Korean interest could be expressed in financial backing for the building of SIR stations in Korea and the opportunity could arise for BNFL to win fuel supply contracts. (UK)

  13. ECG-triggered {sup 18}F-fluorodeoxyglucose positron emission tomography imaging of the rat heart is dramatically enhanced by acipimox

    Energy Technology Data Exchange (ETDEWEB)

    Poussier, Sylvain [Experimental Imaging Platform, Nancyclotep, Nancy (France); CHU-Nancy, Department of Nuclear Medicine, Nancy (France); Nancy University, Faculty of Medicine, Nancy (France); Hopital de Brabois, Nancyclotep, Service de Medecine Nucleaire, Vandoeuvre-les-Nancy (France); Maskali, Fatiha [Experimental Imaging Platform, Nancyclotep, Nancy (France); CHU-Nancy, Department of Nuclear Medicine, Nancy (France); Tran, Nguyen [Nancy University, Faculty of Medicine, Nancy (France); Surgery School, Faculty of Medicine, Nancy (France); INSERM U961, Nancy (France); Person, Christophe; Boutley, Henri; Karcher, Gilles [Experimental Imaging Platform, Nancyclotep, Nancy (France); CHU-Nancy, Department of Nuclear Medicine, Nancy (France); Nancy University, Faculty of Medicine, Nancy (France); Maureira, Pablo [Nancy University, Faculty of Medicine, Nancy (France); Surgery School, Faculty of Medicine, Nancy (France); CHU-Nancy, Department of Cardiac Surgery, Nancy (France); Lacolley, Patrick; Regnault, Veronique [Nancy University, Faculty of Medicine, Nancy (France); INSERM U961, Nancy (France); Fay, Renaud [Centre d' Investigation Clinique, INSERM, U9501, Nancy (France); Marie, Pierre Yves [Experimental Imaging Platform, Nancyclotep, Nancy (France); CHU-Nancy, Department of Nuclear Medicine, Nancy (France); Nancy University, Faculty of Medicine, Nancy (France); INSERM U961, Nancy (France)

    2010-09-15

    {sup 18}F-Fluorodeoxyglucose (FDG) imaging, provided by current positron emission tomography (PET) systems dedicated to small animals, might provide a precise functional assessment of the left ventricle (LV) in rats, although conventional metabolic conditioning by hyperinsulinaemic glucose clamping is not well adapted to this setting. This study was aimed at assessing cardiac FDG PET in rats pre-medicated with acipimox, a potent nicotinic acid derivative yielding comparable image quality to clamping in man. Metabolic conditioning was compared in Wistar rats between a conventional oral glucose loading (1.5 mg/kg) and acipimox, which was given at high but well tolerated doses subcutaneously (25 mg/kg) or orally (50 mg/kg). Myocardial to blood (M/B) activity ratio and myocardial signal to noise (S/N) ratio were analysed on gated FDG PET images. The S/N ratio of the gated cardiac images evolved in parallel with the M/B activity ratio and these two ratios were independently enhanced by glucose loading and acipimox. However, these enhancements were: (1) dramatic for acipimox, especially for the high oral dose of 50 mg/kg (from 2.85 {+-} 0.57 to 10.73 {+-} 0.54 for the M/B ratio of rats with or without glucose loading; p < 0.0001) and (2) much more limited for glucose loading (from 6.61 {+-} 0.49 to 7.89 {+-} 0.41 for the M/B ratio of rats with or without acipimox administration; p = 0.049). With the high oral dose of acipimox, the gated cardiac FDG PET images had very high S/N ratios, at least equivalent to those currently documented in man. Metabolic conditioning by oral doses of acipimox is highly efficient for experimental studies planned with cardiac FDG PET in rats. (orig.)

  14. Energy prospects

    International Nuclear Information System (INIS)

    Lyall, K.

    1991-01-01

    The Business Council of Australia's study on Prospects for Improved Energy Efficiency and the Application of Renewable Energy Resources is summarised. The study estimates that replacement of all off-peak electric units in Australia with solar gas boosted systems would reduce electricity consumption for residential water heating by approximately 25% and almost halve carbon dioxide emissions resulting from residential water heating. Furthermore, substitution of all water heating units in Australia with solar gas systems would reduce total emissions by about 80%. The study concludes that while substitution on such a scale could not readily be achieved even within several decades, the estimates do indicate the significant benefits that might be realised by a long term program. 2 refs., 3 tabs

  15. Application of iterative reconstruction in prospective electrocardiography-triggered CT coronary angiography

    International Nuclear Information System (INIS)

    Hou Yang; Yu Bing; Guo Qiyong; Wang Yuke; Yu Mei

    2013-01-01

    Objective: To assess the image quality (IQ) of an iterative reconstruction (IR) technique (iDose"4) from prospective electrocardiography (ECG)-triggered coronary CTA on a 256 MSCT scanner and determine the optimal dose reduction using IR that can provide IQ comparable to filtered back projection (FBP). Methods: Prospectively ECG gated CCTA were performed on 120 patients [76 men, 44 women; age: (53 ± 10) y] using a 256-slice MSCT (Brilliance iCT, Philips Healthcare). The control group (Group A , n = 30) were scanned using the conventional tube output (120 kVp, 210 mAs) and reconstructed using FBP. The other 3 groups were scanned with the same kVp but successively reduced tube output as follows: B (n = 30) : 105 mAs , C (n = 30) : 84 mAs: D (n = 30) : 65 mAs and reconstructed using IR levels of L4 to L6, respectively. All images were reconstructed using the same kernel (XCB). Two radiologists graded IQ in a blinded fashion on a 4-point scale (4-excellent, 3-good, 2-fair and 1-poor). Quantitative measurements of CT values, image noise, Signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were obtained in each group. Analysis of variance (ANOVA) was used for comparisons of objective evaluation indices (noise, CNR) and radiation dose (CTDIvol, DLP, ED) between the four groups. The Kruskal-Wallis test was used for comparisons of demographic data and for detection of differences in subjective evaluation of IQ among groups. A level of P < 0.05 was considered statistically significant. A ROC analysis was performed to determine a radiation reduction threshold up to which excellent IQ was maintained. Results: There was no significant differences in objective noise among Groups A (37.4 ± 7.9) HU, B (33.2 ± 7.1) HU, C (35.7 ± 9.8) HU, and D (36.0 ± 6.8) HU (F = 1.48, P = 0.22). There was no significant differences in CNR among Groups A (15.0 ± 2.3), B (16.5 ± 3.6), C (16.3 ± 3.5), and D (15.3 ± 2.8) (F = 1.70, P = 0.17). Group B and C had good and excellent

  16. Uranium project. Geochemistry prospection

    International Nuclear Information System (INIS)

    Lambert, J.

    1983-01-01

    Geochemistry studies the distribution of the chemicals elements in the terrestrial crust and its ways to migrate. The terminology used in this report is the following one: 1) Principles of the prospection geochemistry 2) Stages of the prospection geochemistry 3)utility of the prospection geochemistry 4) geochemistry of uranium 5) procedures used within the framework of uranium project 6) Average available 7) Selection of the zones of prospection geochemistry 8) Stages of the prospection, Sample preparation and analisis 9) Presentation of the results

  17. Geochemical prospecting in Guiana

    International Nuclear Information System (INIS)

    Coulomb, R.

    1957-01-01

    During the last few years geochemical prospecting techniques have become common usage in the field of mineral deposit prospecting. The real scope of these methods lies in their use in the prospecting of large areas. The most promising use of the geochemistry and hydro-geochemistry of uranium is in heavily forested tropical territories, with few outcrops, where radiometry is strongly handicapped. (author) [fr

  18. Endogenous Prospect Theory

    OpenAIRE

    Schmidt, Ulrich; Zank, Horst

    2010-01-01

    In previous models of (cumulative) prospect theory reference-dependence of preferences is imposed beforehand and the location of the reference point is exogenously determined. This paper provides an axiomatization of a new specification of cumulative prospect theory, termed endogenous prospect theory, where reference-dependence is derived from preference conditions and a unique reference point arises endogenously.

  19. Comprehensive low-dose imaging of carotid and coronary arteries with a single-injection dual-source CT angiography protocol

    International Nuclear Information System (INIS)

    Tognolini, A.; Arellano, C.S.; Marfori, W.; Heidari, G.; Sayre, J.W.; Krishnam, M.S.; Ruehm, S.G.

    2014-01-01

    Aim: To assess the feasibility of a fast single-bolus combined carotid and coronary computed tomography angiography (CTA) protocol in asymptomatic patients. Materials and methods: Thirty-three consecutive patients (18 women and 15 men) with a median age of 61 ± 14 years old (range 37–87 years) with known or suspected atherosclerotic disease were enrolled in this prospective study. A single breath-hold, single biphasic injection protocol (50 ml at 3 ml/s, 50 ml at 5 ml/s, 50 ml saline flush at 5 ml/s) was used for combined CTA imaging of the supra-aortic (SAA) and coronary arteries (CA) on a 64-slice dual-source CT (DSCT) machine. Helical CTA acquisition of the SAA was followed by prospective electrocardiography (ECG)-triggered coronary CTA. Subjective (four-point scale) image quality and objective signal-to-noise (SNR) and contrast-to-noise (CNR) measurements were performed. Vascular disease was graded on a four-point scale (grade 1: absent; grade 2: mild, grade 3: moderate; grade 4: severe). The radiation dose was recorded for each patient. Results: The average enhancement and subjective quality score of SAA and CA segments were 396 HU/358 HU and 1.2 ± 0.3/1.72 ± 0.4, respectively. The SNR was 27.1 ± 1.7 in the SAA and 21.6 ± 1.6 in the CA (p < 0.0001). The CNR was 18.1 ± 1.2 and 15.9 ± 1.8, respectively (p = 0.4). Four percent of SAA and 14% of CA segments (mostly due to peri-venous streak artefacts and small calibre, respectively) produced non-diagnostic images. SAA findings were as follows: 26/33 (79%) patients showed no disease and 6/33 (18%) had grade 2 and 1/33 (3%) had grade 3 disease. CA findings were as follows: 25/33 (76%) showed no disease and 6/33 (18%) patients had grade 2 and 2/33 (6%) had grade 3 disease. Five patients had disease in both districts. The average radiation dose for the combined CTA angiogram was 4.3 ± 0.6 mSv. Conclusion: A fast, low-dose combined DSCT angiography protocol appears technically feasible for imaging carotid and

  20. Comprehensive low-dose imaging of carotid and coronary arteries with a single-injection dual-source CT angiography protocol.

    Science.gov (United States)

    Tognolini, A; Arellano, C S; Marfori, W; Heidari, G; Sayre, J W; Krishnam, M S; Ruehm, S G

    2014-03-01

    To assess the feasibility of a fast single-bolus combined carotid and coronary computed tomography angiography (CTA) protocol in asymptomatic patients. Thirty-three consecutive patients (18 women and 15 men) with a median age of 61 ± 14 years old (range 37-87 years) with known or suspected atherosclerotic disease were enrolled in this prospective study. A single breath-hold, single biphasic injection protocol (50 ml at 3 ml/s, 50 ml at 5 ml/s, 50 ml saline flush at 5 ml/s) was used for combined CTA imaging of the supra-aortic (SAA) and coronary arteries (CA) on a 64-slice dual-source CT (DSCT) machine. Helical CTA acquisition of the SAA was followed by prospective electrocardiography (ECG)-triggered coronary CTA. Subjective (four-point scale) image quality and objective signal-to-noise (SNR) and contrast-to-noise (CNR) measurements were performed. Vascular disease was graded on a four-point scale (grade 1: absent; grade 2: mild, grade 3: moderate; grade 4: severe). The radiation dose was recorded for each patient. The average enhancement and subjective quality score of SAA and CA segments were 396 HU/358 HU and 1.2 ± 0.3/1.72 ± 0.4, respectively. The SNR was 27.1 ± 1.7 in the SAA and 21.6 ± 1.6 in the CA (p grade 2 and 1/33 (3%) had grade 3 disease. CA findings were as follows: 25/33 (76%) showed no disease and 6/33 (18%) patients had grade 2 and 2/33 (6%) had grade 3 disease. Five patients had disease in both districts. The average radiation dose for the combined CTA angiogram was 4.3 ± 0.6 mSv. A fast, low-dose combined DSCT angiography protocol appears technically feasible for imaging carotid and coronary atherosclerotic disease. Copyright © 2013 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.

  1. Psychophysiology of prospective memory.

    Science.gov (United States)

    Rothen, Nicolas; Meier, Beat

    2014-01-01

    Prospective memory involves the self-initiated retrieval of an intention upon an appropriate retrieval cue. Cue identification can be considered as an orienting reaction and may thus trigger a psychophysiological response. Here we present two experiments in which skin conductance responses (SCRs) elicited by prospective memory cues were compared to SCRs elicited by aversive stimuli to test whether a single prospective memory cue triggers a similar SCR as an aversive stimulus. In Experiment 2 we also assessed whether cue specificity had a differential influence on prospective memory performance and on SCRs. We found that detecting a single prospective memory cue is as likely to elicit a SCR as an aversive stimulus. Missed prospective memory cues also elicited SCRs. On a behavioural level, specific intentions led to better prospective memory performance. However, on a psychophysiological level specificity had no influence. More generally, the results indicate reliable SCRs for prospective memory cues and point to psychophysiological measures as valuable approach, which offers a new way to study one-off prospective memory tasks. Moreover, the findings are consistent with a theory that posits multiple prospective memory retrieval stages.

  2. Approaches to ultra-low radiation dose coronary artery calcium scoring based on 3rd generation dual-source CT : A phantom study

    NARCIS (Netherlands)

    McQuiston, Andrew D.; Muscogiuri, Giuseppe; Schoepf, U. Joseph; Meinel, Felix G.; Canstein, Christian; Varga-Szemes, Akos; Cannao, Paola M.; Wichmann, Julian L.; Allmendinger, Thomas; Vliegenthart, Rozemarijn; De Cecco, Carlo N.

    Objectives: To investigate to what extent 3rd generation dual-source computed tomography (DSCT) can reduce radiation dose in coronary artery calcium scoring. Methods: Image acquisition was performed using a stationary calcification phantom. Prospectively electrocardiogram (ECG)-triggered 120 kV

  3. CANDU market prospects

    International Nuclear Information System (INIS)

    Kakaria, B.K.

    1994-01-01

    This 1994 survey of prospective markets for CANDU reactors discusses prospects in Turkey, Thailand, the Philippines, Korea, Indonesia, China and Egypt, and other opportunities, such as in fuel cycles and nuclear safety. It was concluded that foreign partners would be needed to help with financing

  4. Sharpening Intertemporal Prospect Theory

    OpenAIRE

    Pushpa, Rathie; Carlos, Radavelli; Sergio, Da Silva

    2006-01-01

    Prospect theory [4] of risky choices has been extended to encompass intertemporal choices [6]. Presentation of intertemporal prospect theory suffers from minor mistakes, however [2]. To clarify the theory we restate it and show further mistakes in current presentations ([6], [2]) of value and discount functions.

  5. Perceiving prospects properly

    Czech Academy of Sciences Publication Activity Database

    Steiner, Jakub; Stewart, C.

    2016-01-01

    Roč. 106, č. 7 (2016), s. 1601-1631 ISSN 0002-8282 Institutional support: RVO:67985998 Keywords : evolution * perception bias * prospect theory Subject RIV: AH - Economics Impact factor: 4.026, year: 2016

  6. The effect of low-dose β-blocker on heart rate and heart rate variability in health subjects wth a resting heart rate of less than 65 beats per minute: Effect on the quality of prospective electrocardiography-gated coronary CT angiography

    International Nuclear Information System (INIS)

    Park, Chul Hwan; Kim, Tae Hoon; Lee, Sang Min; Hong, Yoo Jin

    2015-01-01

    We assessed the effect of a low-dose β-blocker on heart rate (HR), HR variability (HRV) and image quality of prospective electrocardiography-gated coronary CT angiography (CCTA) in healthy subjects with low HR. CCTA was performed with a 64-slice CT in 75 subjects with a HR of less than 65 beats per minute (bpm). Subjects were divided into 2 groups: Group 1 (G1), 35 with a low dose β-blocker; and Group 2 (G2), 40 without pre-medication. The image quality (IQ) of the CCTA was assessed on a 4-point grading scale (1, poor; 4, excellent). Initial HR (bpm) was not different between the 2 groups. HR during CCTA was lower in G1 than G2 (50.3 ± 5.6 vs. 53.3 ± 4.8, p = 0.016). HRV was not different between the 2 groups. Per-segment analysis showed better IQ at the mid-segment of the right coronary artery (3.0 ± 0.9 vs. 2.5 ± 1.1, p = 0.039) and the first diagonal branch (3.4 ± 0.6 vs. 3.1 ± 0.7, p = 0.024), in the G1 than the G2 group, respectively. The IQ was negatively correlated with HR, but no correlation was found between HRV and IQ. The IQs in the per-vessel analysis were not different between the 2 groups. Low-dose β-blocker reduced HR and improved the IQ of CCTA in a few segments, even at a HR of less than 65 bpm. However the effect was limited.

  7. The effect of low-dose β-blocker on heart rate and heart rate variability in health subjects wth a resting heart rate of less than 65 beats per minute: Effect on the quality of prospective electrocardiography-gated coronary CT angiography

    Energy Technology Data Exchange (ETDEWEB)

    Park, Chul Hwan; Kim, Tae Hoon [Dept. of Radiology and Research Institute of Radiological Science, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul (Korea, Republic of); Lee, Sang Min [Dept. of Radiology and Research Institute of Radiology, Asan Medical Center, University of Ulsan College of Medicine, Seoul (Korea, Republic of); Hong, Yoo Jin [Dept. of Radiology and Research Institute of Radiological Science, Severance Hospital, Yonsei University College of Medicine, Seoul (Korea, Republic of)

    2015-02-15

    We assessed the effect of a low-dose β-blocker on heart rate (HR), HR variability (HRV) and image quality of prospective electrocardiography-gated coronary CT angiography (CCTA) in healthy subjects with low HR. CCTA was performed with a 64-slice CT in 75 subjects with a HR of less than 65 beats per minute (bpm). Subjects were divided into 2 groups: Group 1 (G1), 35 with a low dose β-blocker; and Group 2 (G2), 40 without pre-medication. The image quality (IQ) of the CCTA was assessed on a 4-point grading scale (1, poor; 4, excellent). Initial HR (bpm) was not different between the 2 groups. HR during CCTA was lower in G1 than G2 (50.3 ± 5.6 vs. 53.3 ± 4.8, p = 0.016). HRV was not different between the 2 groups. Per-segment analysis showed better IQ at the mid-segment of the right coronary artery (3.0 ± 0.9 vs. 2.5 ± 1.1, p = 0.039) and the first diagonal branch (3.4 ± 0.6 vs. 3.1 ± 0.7, p = 0.024), in the G1 than the G2 group, respectively. The IQ was negatively correlated with HR, but no correlation was found between HRV and IQ. The IQs in the per-vessel analysis were not different between the 2 groups. Low-dose β-blocker reduced HR and improved the IQ of CCTA in a few segments, even at a HR of less than 65 bpm. However the effect was limited.

  8. Inadequate increase in the volume of major epicardial coronary arteries compared with that in left ventricular mass. Novel concept for characterization of coronary arteries using 64-slice computed tomography.

    Science.gov (United States)

    Ehara, Shoichi; Okuyama, Takuhiro; Shirai, Nobuyuki; Sugioka, Kenichi; Oe, Hiroki; Itoh, Toshihide; Matsuoka, Toshiyuki; Ikura, Yoshihiro; Ueda, Makiko; Naruko, Takahiko; Hozumi, Takeshi; Yoshiyama, Minoru

    2009-08-01

    Previous studies have shown a correlation between coronary artery cross-sectional diameter and left ventricular (LV) mass. However, no studies have examined the correlation between actual coronary artery volume (CAV) and LV mass. In the present study, measurements of CAV by 64-multislice computed tomography (MSCT) were validated and the relationship between CAV and LV mass was investigated. First, coronary artery phantoms consisting of syringes filled with solutions of contrast medium moving at simulated heart rates were scanned by 64-MSCT. Display window settings permitting accurate calculation of small volumes were optimized by evaluating volume-rendered images of the segmented contrast medium at different window settings. Next, 61 patients without significant coronary artery stenosis were scanned by 64-MSCT with the same protocol as for the phantoms. Coronary arteries were segmented on a workstation and the same window settings were applied to the volume-rendered images to calculate total CAV. Significant correlations between total CAV and LV mass (r=0.660, Pconcept of "CAV" for the characterization of coronary arteries may prove useful for future research, particularly on the causes of LV hypertrophy.

  9. Experimental measurement of the scatter fraction in skull and body CT for teams 64- slice computed tomography; Medida experimental de la fraccion de dispersion TC en craneo y cuerpo para equipo de tomografia computarizada de 64 cortes

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez, G.; Haro, G.; Herrador, M.

    2011-07-01

    Different formalisms for the calculation of shielding in Cf equipment, the proposed document 147 of NCRP are widely accepted. Of the three methods mentioned in the protocol, two involve the use of two independent factor a of equipment, called scatter fraction CT in skull and body. Interestingly, the experimental measurement of the same, especially in those models following the publication of the document, which are also coincides with the highest number of detector channels and overall a greater radiation beam in the z axis.

  10. Low fingertip temperature rebound measured by digital thermal monitoring strongly correlates with the presence and extent of coronary artery disease diagnosed by 64-slice multi-detector computed tomography.

    Science.gov (United States)

    Ahmadi, Naser; Nabavi, Vahid; Nuguri, Vivek; Hajsadeghi, Fereshteh; Flores, Ferdinand; Akhtar, Mohammad; Kleis, Stanley; Hecht, Harvey; Naghavi, Morteza; Budoff, Matthew

    2009-10-01

    Previous studies showed strong correlations between low fingertip temperature rebound measured by digital thermal monitoring (DTM) during a 5 min arm-cuff induced reactive hyperemia and both the Framingham Risk Score (FRS), and coronary artery calcification (CAC) in asymptomatic populations. This study evaluates the correlation between DTM and coronary artery disease (CAD) measured by CT angiography (CTA) in symptomatic patients. It also investigates the correlation between CTA and a new index of neurovascular reactivity measured by DTM. 129 patients, age 63 +/- 9 years, 68% male, underwent DTM, CAC and CTA. Adjusted DTM indices in the occluded arm were calculated: temperature rebound: aTR and area under the temperature curve aTMP-AUC. DTM neurovascular reactivity (NVR) index was measured based on increased fingertip temperature in the non-occluded arm. Obstructive CAD was defined as >or=50% luminal stenosis, and normal as no stenosis and CAC = 0. Baseline fingertip temperature was not different across the groups. However, all DTM indices of vascular and neurovascular reactivity significantly decreased from normal to non-obstructive to obstructive CAD [(aTR 1.77 +/- 1.18 to 1.24 +/- 1.14 to 0.94 +/- 0.92) (P = 0.009), (aTMP-AUC: 355.6 +/- 242.4 to 277.4 +/- 182.4 to 184.4 +/- 171.2) (P = 0.001), (NVR: 161.5 +/- 147.4 to 77.6 +/- 88.2 to 48.8 +/- 63.8) (P = 0.015)]. After adjusting for risk factors, the odds ratio for obstructive CAD compared to normal in the lowest versus two upper tertiles of FRS, aTR, aTMP-AUC, and NVR were 2.41 (1.02-5.93), P = 0.05, 8.67 (2.6-9.4), P = 0.001, 11.62 (5.1-28.7), P = 0.001, and 3.58 (1.09-11.69), P = 0.01, respectively. DTM indices and FRS combined resulted in a ROC curve area of 0.88 for the prediction of obstructive CAD. In patients suspected of CAD, low fingertip temperature rebound measured by DTM significantly predicted CTA-diagnosed obstructive disease.

  11. Effectiveness of Adaptive Statistical Iterative Reconstruction for 64-Slice Dual-Energy Computed Tomography Pulmonary Angiography in Patients With a Reduced Iodine Load: Comparison With Standard Computed Tomography Pulmonary Angiography.

    Science.gov (United States)

    Lee, Ji Won; Lee, Geewon; Lee, Nam Kyung; Moon, Jin Il; Ju, Yun Hye; Suh, Young Ju; Jeong, Yeon Joo

    2016-01-01

    The aim of the study was to assess the effectiveness of the adaptive statistical iterative reconstruction (ASIR) for dual-energy computed tomography pulmonary angiography (DE-CTPA) with a reduced iodine load. One hundred forty patients referred for chest CT were randomly divided into a DE-CTPA group with a reduced iodine load or a standard CTPA group. Quantitative and qualitative image qualities of virtual monochromatic spectral (VMS) images with filtered back projection (VMS-FBP) and those with 50% ASIR (VMS-ASIR) in the DE-CTPA group were compared. Image qualities of VMS-ASIR images in the DE-CTPA group and ASIR images in the standard CTPA group were also compared. All quantitative and qualitative indices, except attenuation value of pulmonary artery in the VMS-ASIR subgroup, were superior to those in the VMS-FBP subgroup (all P ASIR images were superior to those of ASIR images in the standard CTPA group (P ASIR images of the DE-CTPA group than in ASIR images of the standard CTPA group (P = 0.001). The ASIR technique tends to improve the image quality of VMS imaging. Dual-energy computed tomography pulmonary angiography with ASIR can reduce contrast medium volume and produce images of comparable quality with those of standard CTPA.

  12. Worldwide prospects of uranium prospection and production

    International Nuclear Information System (INIS)

    Beaumont, Claude; Duval, B.C.; Sarcia, J.A.

    1978-01-01

    The reserves of uranium ores, at present known in the western world, at a mining price below 80 US dollars per kilo, permit the needs corresponding to the life of the existing reactors to be satisfied until 1988; the more expensive estimated resources taken into account would permit an extension beyond the end of the century. But the transition from available reserves and their renewal to the evaluated reserves necessitates from now a considerable prospecting effort. There are great geological possibilities to cover needs: beside the known types of deposits which give the present production, there exist numerous other prospects which appear of interest to underline; nevertheless, they require a certain amount of progress, other methods of detection such as the metal extractive processes which are not necessarily beyond the reach of science and techniques. Obstacles are due to the fact that the scrupules of ecologic necessities are often slightly inconsiderate, and that states intervene more and more in the extractive industry when the object is not to satisfy their own needs. Lastly, the uncertainty of the long market (breeder or not) risk to discourage the effort of investors [fr

  13. Prospects after Major Trauma

    NARCIS (Netherlands)

    Holtslag, H.R.

    2007-01-01

    Introduction. After patients survived major trauma, their prospects, in terms of the consequences for functioning, are uncertain, which may impact severely on patient, family and society. The studies in this thesis describes the long-term outcomes of severe injured patients after major trauma. In

  14. A Prospective Observational Study

    African Journals Online (AJOL)

    Methods: This was a prospective, questionnaire-based observational study. Printed questionnaires were distributed to the visitors of medical, surgical and neurosurgical ICU patients to determine awareness of basic infection control practices among visitors to an ICU. All the ICU staff, including nurses, doctors, consultant ...

  15. Prospects for Tau Physics

    International Nuclear Information System (INIS)

    Lafferty, George D.

    2009-01-01

    The tau lepton is a powerful tool with which to study a wide variety of physics in and beyond the Standard Model. We review the prospects for tau physics in the light of recent progress at the B factories and elsewhere, and we consider the tau physics that may come from future accelerators.

  16. Perceiving prospects properly

    Czech Academy of Sciences Publication Activity Database

    Steiner, Jakub; Stewart, C.

    2016-01-01

    Roč. 106, č. 7 (2016), s. 1601-1631 ISSN 0002-8282 R&D Projects: GA ČR(CZ) GA13-34759S; GA ČR(CZ) GA16-00703S Institutional support: PRVOUK-P23 Keywords : evolution * perception bias * prospect theory Subject RIV: AH - Economics Impact factor: 4.026, year: 2016

  17. Indochina area mineral prospects

    Energy Technology Data Exchange (ETDEWEB)

    1990-10-05

    Prospects for commercial mining of various minerals are considered for Kampuchea (Cambodia), Laos, Vietnam, Myanmar (Burma) and Thailand. Mineral production is much below its geologic potential for economic and political reasons. Resource potential is limited to tin, tungsten, lead and zinc, barytes and gemstones, and coal. 1 fig.

  18. Energy prospects for industry

    Energy Technology Data Exchange (ETDEWEB)

    Hartley, P P; Roberts, G F.I.; Thomas, V E; Davies, D; Crow, L M

    1983-01-01

    Contents: Electricity today and tomorrow; Gas--supply prospects for the future; Petroleum based energy--the UK perspective; Future markets for coal; Flexibility--the key to Dunlop's energy strategy; Energy conservation in Alcan; Present and future energy patterns in Courtaulds PLC; New energy technology for the quarrying industry.

  19. Nuclear power prospects

    International Nuclear Information System (INIS)

    Staebler, K.

    1994-01-01

    The technical, economic and political prospects of nuclear power are described with regard to ecological aspects. The consensus talks, which failed in spite of the fact that they were stripped of emotional elements and in spite of major concessions on the part of the power industry, are discussed with a view to the political and social conditions. (orig.) [de

  20. Radimetric autotransported prospecting survey

    International Nuclear Information System (INIS)

    Coco, A.L.; Azamor, L.A.; Agost, E.J.

    1977-10-01

    A procedure of prospection of minerals (''carborne''). It is characterized to be rapid and low costly if a sufficiently dense highway network is available or if transit with a vehicle across the fields is possible. Instruments, methods and results that may be obtained are given. The detector, a scintillation counter, is mounted on the top of an appropiate car registering continuously the measured values. Subsequently data are put on cartography, obtaining thus the values of iso-radiactivity which determine the values of ''background'' and the favorable zones for pursuing prospection work by other methods. The application of the method to the zone of the Chihuidos, province of Neuquen, is described in details and the obtained conclusions are given. (author) [es

  1. The uranium market prospects

    International Nuclear Information System (INIS)

    Lloyd, R.

    1981-01-01

    A historical analysis of the uranium market points out the cyclical nature of the market and suggests that the spot price, exploration levels, and mill capacity utilization rate are dependent on economic factors. An examination of the current uranium market suggests that the effects of the forecasted surplus supply, the diminishing returns in exploration and the long lead times and high costs of development may mean that future production levels are uncertain. The general prospects for the uranium industry are also uncertain because of barriers to trade, environmental regulations and public opinion. The paper concludes that by the use of long term contracts, appropriate inventory policy and greater discussion between producers and consumers the prospects for the uranium market can be made more certain and further imbalances in demand and supply can be avoided. (author)

  2. Future prospects of pregeometry

    International Nuclear Information System (INIS)

    Terazawa, Hidezumi.

    1991-06-01

    Pregeometry is a theory, first suggested by Sakharov in 1967, in which gravity is taken as a quantum effect of matter fields and in which Einstein's theory of general relativity for gravity appears as an approximate and effective theory at long distances. It is shown by reviewing the extensive developments of pregeometric theories of gravity for the last more than a decade that the original idea by Sakharov is really working. Many future prospects of the theories are discussed in some detail. (author)

  3. Health values and prospect theory.

    Science.gov (United States)

    Treadwell, J R; Lenert, L A

    1999-01-01

    Health values are important components of medical decisions. Experimental data suggest that people value health in complex and dynamic ways. Prospect theory is a descriptive theory of choice that may accurately characterize how people assign values to health states. The authors first provide background on prospect theory and how it can be applied to health values. Next, they review the relevant health research and find mixed support for prospect theory. Last, they discuss implications of prospect theory for cost-effectiveness analysis. The application of prospect theory to health deserves further research because it may help clarify the link between health and values.

  4. SVX b physics prospects

    International Nuclear Information System (INIS)

    Dell'Agnello, S.

    1992-11-01

    CDF has enhanced its capabilities for b-physics with the installation of a silicon vertex detector (SVX), which provides precise 2-dimensional tracking. The SVX impact parameter (IP) resolution (∼ 13μm for P t > 10 GeV) is well suited to detecting displaced secondary vertices (SV) from b-hadron decays (cτ B ≅ 390μm). In this paper we show evidence of SV detection using the Ψ → μ + μ - sample, which is b-enriched, and describe some prospects of b physics opened by the SVX with 25 pb -1 , the goal integrated luminosity of present run

  5. Geography, prospects, problems

    International Nuclear Information System (INIS)

    Fischer, D.A.V.

    1982-01-01

    In assessing the application of IAEA safeguards to the world's nuclear industry it is shown that the continuing success of the system depends to a large degree on the political will of the Agency's Member States and of other parties to the Treaty on the Non-Proliferation of Nuclear Weapons in ensuring both that adequate resources are provided for the safeguards operation and also that safeguards are effectively and impartially applied. The present positions concerning NPT membership, non-NPT safeguards and future prospects with respect to the operation of safeguarded and unsafeguarded facilities are discussed. Political problems which impede the effective application of safeguards are considered. (U.K.)

  6. Astronautics summary and prospects

    CERN Document Server

    Kiselev, Anatoly Ivanovich; Menshikov, Valery Alexandrovich

    2003-01-01

    The monograph by A.I.Kiselev, A.A. Medvedev and Y.A.Menshikov, Astronautics: Summary and Prospects, aroused enthusiasm both among experts and the public at large. This is due to the felicitous choice of presentation that combines a simple description of complex space matters with scientificsubstantiation of the sub­ jectmatter described. The wealth of color photos makes the book still more attractive, and it was nominated for an award at the 14th International Moscow Book Fair, being singled out as the "best publication of the book fair". The book's popularity led to a second edition, substantially revised and enlarged. Since the first edition did not sufficiently cover the issues of space impact on ecology and the prospective development of space systems, the authors revised the entire volume, including in it the chapter "Space activity and ecology" and the section "Multi-function space systems". Using the federal monitoring system, now in the phase of system engi­ neering, as an example, the authors consi...

  7. Summary and Prospect.

    Science.gov (United States)

    Wei, Zhengde; Chen, Xueli; Zhang, Xiaochu

    2017-01-01

    In this chapter, the main content is to summarize the similarities and differences between substance and non-substance addictions in several aspects, involving definition, mechanisms, diagnosis and treatment. We try to display the complete picture of addictions in a brief but comprehensive way. Mechanism includes molecule and neural circuit, genetics, neuroimaging and cognitive psychology; diagnosis includes diagnostic criterion, diagnostic scales, biochemical diagnosis and new diagnostic techniques; treatment includes drug therapy, physical therapy, traditional Chinese medical therapy, nutrition support therapy, psychotherapy and cognitive-behavioral therapy. This chapter also covers some prospect which will induct future studies on addiction. We aim at providing the researchers and graduate students with better understanding of substance and non-substance addictions.

  8. Prospects for HTS applications

    International Nuclear Information System (INIS)

    Gamble, B.B.; Snitchler, G.L.; Schwall, R.E.

    1996-01-01

    High temperature superconductor (HTS) wire is rapidly maturing into a working material being produced in ever larger quantities and being used in more significant demonstrations and prototypes. Conductor is now produced routinely in several hundred meter lengths with reproducible results. Current density has progressed to a level suitable for demonstration of many applications. Wire strength has improved and large prototypes fabricated or under consideration using HTS include Superconducting Magnetic Energy Storage (SMES), rotating electrical machines including synchronous ac and dc homopolar motors and drives, generators and condensers, underground transmission cables, utility distribution equipment such as transformers and current limiters, commercial processing applications such as magnetic separation, and specialty magnets such as high field inserts. In this paper the requirements, progress toward these requirements, and the prospects for the future are reviewed

  9. Prospects for future climate

    International Nuclear Information System (INIS)

    Anon.

    1990-01-01

    The different climates of the past and model simulations of future climates convincingly indicate that the continuing emissions of greenhouse gases will lead to significant global warming and to changes in precipitation and other climatic variables. The projected changes in atmospheric composition and, consequently, in climatic conditions will be unique and more rapid than at any time in the past. The developing understanding of the chemical cycles controlling atmospheric composition and of the processes and behavior controlling the climate system can provide significant guidance about how the future climate will change. This chapter first summarizes the many scientific advances described in the preceding chapters that can help one better understand and describe the climate system and the resulting agricultural and hydrological impacts of these changes in climate. The chapter then draws from this understanding to outline the prospects for future climate

  10. Prospects at high energies

    International Nuclear Information System (INIS)

    Quigg, C.

    1988-11-01

    I discuss some possibilities for neutrino experiments in the fixed-target environment of the SPS, Tevatron, and UNK, with their primary proton beams of 0.4, 0.9, and 3.0 TeV. The emphasis is on unfinished business: issues that have been recognized for some time, but not yet resolved. Then I turn to prospects for proton-proton colliders to explore the 1-TeV scale. I review the motivation for new physics in the neighborhood of 1 TeV and mention some discovery possibilities for high-energy, high-luminosity hadron colliders and the implications they would have for neutrino physics. I raise the possibility of the direct study of neutrino interactions in hadron colliders. I close with a report on the status of the SSC project. 38 refs., 17 figs

  11. Prospects for gauge theories

    International Nuclear Information System (INIS)

    Bailin, D.

    1980-01-01

    The author reviews the present status of the standard model of weak and electromagnetic interactions and of QCD and examines the likely avenues of future development. The most attractive possibility is that there is a ''grand unified theory'' (GUT) which describes all known interactions except gravity, and in which the only input energy scale is the Planck mass. The GUTs so far proposed share the deficiency that they offer no explanation of the (>=3) observed fermion generations. The author reviews the 'horizontal' symmetries invented to bring order to the fermion sector. Typically such theories have non-minimal Higgs content, so he reviews the processes whereby charged or neutral scalars may be found. The incorporation of supersymmetry into the gauge theory of strong, weak and electromagnetic interactions is another attractive prospect and he discusses briefly the attempts to do this and the likely experimental signatures of such a scheme. (Auth.)

  12. Oil price prospects

    International Nuclear Information System (INIS)

    Toalster, J.

    1992-01-01

    In this paper, four different, popular approaches to the analysis of oil price movements will be considered and an alternative method will be proposed. Whilst we await the development of a rigorous theoretical framework within which to evaluate the phenomenon of oil price movements some progress may be effected by an amalgam of approaches, with the traditional supply and demand model being supplemented by observations regarding political and social developments in particular countries or regions, together with an assessment of emerging and prospective technological achievements. In this way it should be possible to identify the critical influences at work, from which it should also be possible to select either the single most important variable or combination of variables, affecting the oil price. Moreover, it is my belief that the crucial variables influencing the oil price almost certainly, are more likely to be political and social, rather than economic. In this context and notwithstanding the fact that there is only a minimal level of surplus productive capacity in the world oil industry at present (perhaps 1-2 million b/d albeit rising rapidly), it is reasonable to conclude that oil prices will average around $18-19 a barrel for North Sea Brent in 1992 and 1993, with oscillations of $2-4 a barrel either side, rising slightly in 1994 to $19-20 a barrel and to $20-21 a barrel in 1995. Thereafter, the most likely outcome is for a rise in line with inflation (say $ a barrel/annum) with no prospect of an upward spike, because demand will be weaker than most commentators expect up to the year 2000, whilst OPEC oil supplies will be substantially higher than the consensus forecast. (author)

  13. Location-based prospective memory.

    Science.gov (United States)

    O'Rear, Andrea E; Radvansky, Gabriel A

    2018-02-01

    This study explores location-based prospective memory. People often have to remember to do things when in a particular location, such as buying tissues the next time they are in the supermarket. For event cognition theory, location is important for structuring events. However, because event cognition has not been used to examine prospective memory, the question remains of how multiple events will influence prospective memory performance. In our experiments, people delivered messages from store to store in a virtual shopping mall as an ongoing task. The prospective tasks were to do certain activities in certain stores. For Experiment 1, each trial involved one prospective memory task to be done in a single location at one of three delays. The virtual environment and location cues were effective for prospective memory, and performance was unaffected by delay. For Experiment 2, each trial involved two prospective memory tasks, given in either one or two instruction locations, and to be done in either one or two store locations. There was improved performance when people received instructions from two locations and did both tasks in one location relative to other combinations. This demonstrates that location-based event structure influences how well people perform on prospective memory tasks.

  14. Prospect Theory and Coercive Bargaining

    Science.gov (United States)

    Butler, Christopher K.

    2007-01-01

    Despite many applications of prospect theory's concepts to explain political and strategic phenomena, formal analyses of strategic problems using prospect theory are rare. Using Fearon's model of bargaining, Tversky and Kahneman's value function, and an existing probability weighting function, I construct a model that demonstrates the differences…

  15. Endogenizing Prospect Theory's Reference Point

    OpenAIRE

    Ulrich Schmidt; Horst Zank

    2010-01-01

    In previous models of (cumulative) prospect theory reference-dependence of preferences is imposed beforehand and the location of the reference point is exogenously determined. This note provides a foundation of prospect theory, where reference-dependence is derived from preference conditions and a unique reference point arises endogenously.

  16. Priorities and prospect theory.

    Science.gov (United States)

    Happich, M; Mazurek, B

    2002-01-01

    Whose preferences are to be used for cost-effectiveness analysis? It has been recommended that community preferences for health states are the most appropriate ones for use in a reference case analysis. However, critics maintain that persons are not able properly to judge a health state if they have not experienced the condition themselves. This problem is analyzed here in the framework of Prospect Theory. It can be argued that the differing reference points of patients and the general public are responsible for deviating results. In addition, we argue that risk attitudes with respect to health-related quality of life are an indicator of reference points. If patients and the general public refer to the same reference point, i.e., they have the same risk attitude, the hypothesis is that deviations no longer significantly differ. Evaluations of the health condition of tinnitus by 210 patients and 210 unaffected persons were compared. The Time Tradeoff and Standard Gamble methods were applied to elicit preferences. Risk attitude was measured with the question of whether participants would undergo a treatment that could either improve or worsen their health condition, both with an equal chance (five possible answers between "in no case" and "in any case"). Affected persons indicated significantly higher values for tinnitus-related quality of life according to the Standard Gamble method. The difference between Time Tradeoff values was less dramatic but still significant. In addition, nonaffected persons are more risk-averse than affected persons. However, differences in evaluations are not significant considering single risk groups (e.g., those who answered "in no case"). Prospect Theory is a reasonable framework for considering the question of whose preferences count. If this result can be generalized for other diseases as well, it allows the mathematical combination of "objective" evaluations by the general public with the illness experience of patients. These

  17. IPY Progress and Prospects

    Science.gov (United States)

    Carlson, D.

    2008-12-01

    We can summarize the IPY goals as: (a) make major advances in polar knowledge and understanding; (b) leave a legacy of new or enhanced observational systems, facilities and infrastructure; (c) excite a new generation of polar scientists and engineers, and (d) elicit exceptional interest and participation from polar residents, schoolchildren, the general public, and decision-makers, worldwide. This talk reports on the progress and prospects in each of those areas from an overall international view; separate talks will describe details of future researcher and the IPY outreach efforts. To achieve major advances in knowledge, IPY has entrained the intellectual resources of thousands of scientists, many more than expected, often from 'non- polar' nations, and representing an unprecedented breadth of scientific specialties; integration of those efforts across disciplines to achieve integrated system-level understanding remains a substantial challenge. Many national and international organizations prepare plans to sustain new and improved observational systems, but clear outcomes and the necessary resources remain elusive. International outreach networks gradually build breadth and strength, largely through IPY Polar Science Days and other internationally- coordinated IPY events. A new Association of Polar Early Career Scientists (APECS) devotes talent and energy to shaping the future of polar research. These activities and networks may, with time and with continued international coordination, achieve an exceptional level of interest and participation. In all areas, much work remains.

  18. Biotechnology: challenges and prospects

    Energy Technology Data Exchange (ETDEWEB)

    Sasson, A.

    1985-04-01

    Rapidly occurring technological breakthroughs in the wake of numerous discoveries in different fields, such as biochemistry, genetic engineering as well as cellular and molecular biology as described in this paper have a variety of industrial applications, and forcasts covering these and various other fields have been made. The emerging bio-industry, covering diverse industries, such as chemical, food, pharmaceutical, etc., as well as the domains of health, environmental protection and abatement of pollution present challenging prospects. Several biotechnology processes relating to bioenergy, fermentation, waste transformation, vaccines, etc. are of particular interest to the developing countries. The 'functioning systems' resulting from the breakthrouth in genetic engineering, entailing extraordinary refinement of analytical techniques and technological progress, pose the challenging task of harnessing them to the advantage of mankind. Providing effective legal protection, conducive to the development of biotechnologies-their innovative process and technological change-is a matter of serious concern, involving practical and economical considerations. Several other issues and questions, such as risk prevention and management of potential dangers and hazards in genetic recombination operation by way of safety regulations and necessary guidelines, questions relating to the clinical trials of the interferons-the wonder drug-as well as questions of professional ethics are raised by biotechnologies. Industry-funded research in biotechnology, where scientific and commercial imperatives are interlocked, has for instance, its repercussions on the traditional thrust of university system, specially the sanctity of autonomy for basic research.

  19. ATLAS Detector Upgrade Prospects

    International Nuclear Information System (INIS)

    Dobre, M

    2017-01-01

    After the successful operation at the centre-of-mass energies of 7 and 8 TeV in 2010-2012, the LHC was ramped up and successfully took data at the centre-of-mass energies of 13 TeV in 2015 and 2016. Meanwhile, plans are actively advancing for a series of upgrades of the accelerator, culminating roughly ten years from now in the high-luminosity LHC (HL-LHC) project, which will deliver of the order of five times the LHC nominal instantaneous luminosity along with luminosity levelling. The ultimate goal is to extend the dataset from about few hundred fb −1 expected for LHC running by the end of 2018 to 3000 fb −1 by around 2035 for ATLAS and CMS. The challenge of coping with the HL-LHC instantaneous and integrated luminosity, along with the associated radiation levels, requires further major changes to the ATLAS detector. The designs are developing rapidly for a new all-silicon tracker, significant upgrades of the calorimeter and muon systems, as well as improved triggers and data acquisition. ATLAS is also examining potential benefits of extensions to larger pseudorapidity, particularly in tracking and muon systems. This report summarizes various improvements to the ATLAS detector required to cope with the anticipated evolution of the LHC luminosity during this decade and the next. A brief overview is also given on physics prospects with a pp centre-of-mass energy of 14 TeV. (paper)

  20. Prospects of particle physics

    International Nuclear Information System (INIS)

    Meyer-Berkhout, U.

    1986-01-01

    Remarkable progress has been achieved in the last two decades in the field of particle physics. From the insight gained by the many experimental data, physicists derive a framework picture of matter on the sub-nuclear level, consisting of fundamental components which interact with each other in a defined and quantitatively detectable manner. The data now available allowed a quantum field theory of strong interactions to be set up for the first time, and a unified theory of electromagnetic and weak interaction. Particle physicists today take particular interest in the problem of whether the strong interaction might fit into an extended unified theory. Such a grand unified theory would have a far-reaching impact on the conceptual models both of the cosmic and sub-nuclear dimensions, and possibly lead to observable effects in domains of energy and mass which will be opened up for experiments by the new accelerator generation underway. Current activities throughout the world for constructing or projecting the new high-energy particle accelerators are outlined in the article, together with the prospects expected by particle physicists, and a look back on the history and achievements of this field of science. (orig.) [de

  1. Uranium prospecting; La prospection de l'uranium

    Energy Technology Data Exchange (ETDEWEB)

    Roubault, M. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1955-07-01

    This report is an instruction book for uranium prospecting. It appeals to private prospecting. As prospecting is now a scientific and technical research, it cannot be done without preliminary studies. First of all, general prospecting methods are given with a recall of fundamental geologic data and some general principles which are common with all type of prospecting. The peculiarities of uranium prospecting are also presented and in particular the radioactivity property of uranium as well as the special aspect of uranium ores and the aspect of neighbouring ores. In a third part, a description of the different uranium ores is given and separated in two different categories: primary and secondary ores, according to the place of transformation, deep or near the crust surface respectively. In the first category, the primary ores include pitchblende, thorianite and rare uranium oxides as euxenite and fergusonite for example. In the second category, the secondary ores contain autunite and chalcolite for example. An exhaustive presentation of the geiger-Mueller counter is given with the presentation of its different components, its functioning and utilization and its maintenance. The radioactivity interpretation method is showed as well as the elaboration of a topographic map of the measured radioactivity. A brief presentation of other detection methods than geiger-Mueller counters is given: the measurement of fluorescence and a chemical test using the fluorescence properties of uranium salts. Finally, the main characteristics of uranium deposits are discussed. (M.P.)

  2. Uranium prospecting; La prospection de l'uranium

    Energy Technology Data Exchange (ETDEWEB)

    Roubault, M [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1955-07-01

    This report is an instruction book for uranium prospecting. It appeals to private prospecting. As prospecting is now a scientific and technical research, it cannot be done without preliminary studies. First of all, general prospecting methods are given with a recall of fundamental geologic data and some general principles which are common with all type of prospecting. The peculiarities of uranium prospecting are also presented and in particular the radioactivity property of uranium as well as the special aspect of uranium ores and the aspect of neighbouring ores. In a third part, a description of the different uranium ores is given and separated in two different categories: primary and secondary ores, according to the place of transformation, deep or near the crust surface respectively. In the first category, the primary ores include pitchblende, thorianite and rare uranium oxides as euxenite and fergusonite for example. In the second category, the secondary ores contain autunite and chalcolite for example. An exhaustive presentation of the geiger-Mueller counter is given with the presentation of its different components, its functioning and utilization and its maintenance. The radioactivity interpretation method is showed as well as the elaboration of a topographic map of the measured radioactivity. A brief presentation of other detection methods than geiger-Mueller counters is given: the measurement of fluorescence and a chemical test using the fluorescence properties of uranium salts. Finally, the main characteristics of uranium deposits are discussed. (M.P.)

  3. PROSPECTS AND CHALLENGES FOR CORPORATE ...

    African Journals Online (AJOL)

    Fr. Ikenga

    Key words: Proxy contest, Corporate governance, Prospects, Challenges, Nigeria ... this advantage, cumulative voting is rare in publicly traded firms and most ..... framework needs to be put in place in Nigeria, which will highlight the gains of ...

  4. LHC physics results and prospects

    CERN Document Server

    Kono, Takanori; The ATLAS collaboration

    2018-01-01

    This talk presents the latest results from LHC Run-2 as of May 2018 which include Standard Model measurements, Higgs boson properties and beyond Standard Model search results. The prospects for future LHC runs are also shown.

  5. Prospect of ultralight airplanes development

    Directory of Open Access Journals (Sweden)

    Adam KONICZEK

    2015-09-01

    Full Text Available The article presents characteristic of ultralight airplanes, rules and current interest of them. The purpose is to determine prospect of ultralight airplanes development on the basis of Civil Aviation Authority statistics analysis and trend of aviation market.

  6. An Agent for the Prospect Presentation Problem

    Science.gov (United States)

    2014-05-01

    Economics, 12:133–158. [18] Daniel Kahneman . Thinking , fast and slow . Allen Lane, London, 2011. [19] Daniel Kahneman and Amos Tversky. Prospect theory...u(X) = log(X) (2) 2.2 Prospect Theory The Prospect Theory was presented by Kahneman and Tversky in [19] and later refined to the Cumulative Prospect...fully rationally, but rather use their own de- cision weights when deciding whether to reject or accept a gamble. In his book, Kahneman [18] (p.314

  7. Domestic kraudfandinh: problems and prospects

    Directory of Open Access Journals (Sweden)

    L.V. Mihalchuk

    2015-03-01

    Full Text Available The description kraudfandinh as an innovative tool to attract private investment in promising business projects as a special type of financing over the Internet. Powered its classification and kraud lists of successful projects, clearly illustrated by comparison of the normal business process to create a product and a similar process using kraudfandinh, given the differences between them and the main advantages. Based on the summaries of the literature and current practices of foreign companies and kraud platforms, defined the prospects of its application by domestic enterprises in various industries, proved its positive impact on the economy of Ukraine. The main problem of the use of this instrument in the domestic business, according to national circumstances, given their explanations. Described the prospects for its implementation at Ukrainian enterprises in terms of economic instability. The characteristic of the first Ukrainian kraudfandinh platforms by their future prospects in this direction

  8. Integrated prospecting model in Jinguanchong uranium deposit

    International Nuclear Information System (INIS)

    Xie Yongjian

    2006-01-01

    Jinguanchong uranium deposit is large in scale, which brings difficulties to prospecting and researches. Based on conditions of mineral-formation, geophysics and geochemistry, this paper summarizes a few geophysical and geochemical prospecting methods applied to this deposit. The principles, characteristics, application condition and exploration phases of these prospecting methods are discussed and some prospecting examples are also given in the prospecting for Jinguanchong uranium deposit. Based on summarizing the practice and effects of different methods such as gamma and electromagnetic method, soil emanation prospecting, track etch technique and polonium method used in uranium prospecting, the author finally puts forward a primary uranium prospecting model for the further prospecting in Jinguanchong uranium deposit through combining the author's experience with practice. (authors)

  9. Rose breeding: past, present, prospects

    NARCIS (Netherlands)

    Vries, de D.P.; Dubois, L.A.M.

    1996-01-01

    In this review the PAST, PRESENT and PROSPECT will be considered as three separate periods in the history of the breeding and development of rose cultivars. The recurring theme is the genetic variation. This theme was chosen because there is justified doubt as to sufficient genetic variation

  10. Future prospects for electron colliders

    CERN Document Server

    Toge, N

    2001-01-01

    An overview on the future prospects for electron colliders is presented. In the first part of this paper we will walk through the status of current development of next-generation electron linear colliders of sub-TeV to TeV energy range. Then we will visit recent results from technological developments which aim at longer term future for higher energy accelerators.

  11. PROFESSIONAL INSECURITIES OF PROSPECTIVE TEACHERS.

    Science.gov (United States)

    LUECK, WILLIAM R.

    TO DETERMINE WHICH COMMON TEACHING PROBLEMS CAUSE THE GREATEST CONCERN OR INSECURITY AMONG PROSPECTIVE TEACHERS, 445 JUNIORS (243 IN 1962-63 AND 205 IN 1963-64) TAKING A SECONDARY SCHOOL METHODS COURSE WERE ASKED TO RANK TWELVE MAJOR PROBLEMS IN THE ORDER IN WHICH THEY CAUSED CONCERN. THE PROBLEMS WERE COMPILED FROM THOSE OCCURRING FREQUENTLY IN…

  12. Job Prospects for Metallurgical Engineering.

    Science.gov (United States)

    Basta, Nicholas

    1985-01-01

    Job prospects in mining, metal-extraction, steel, and refining industries are depressed, but technological discoveries are opening up new fields for metallurgical engineers. Enrollment/employment opportunities and salaries in these areas are discussed a well as the roles of foreign competition, plastics applications, and ceramics research and…

  13. Job Prospects for Electrical Engineers.

    Science.gov (United States)

    Basta, Nicholas

    1986-01-01

    Discusses the career outlook for electrical/electronics engineers. Explains that the number of bachelor degree graduates continues to rise, along with average starting salaries. Reveals that although the availability of jobs in the computer industry is leveling off, prospects in the robotics and telecommunication fields are growing. (TW)

  14. Saudi Arabia: Problems and prospects

    International Nuclear Information System (INIS)

    Granata, V.; Palermo, M.

    1993-01-01

    Saudi Arabia has a central role in the world oil market. After analyzing the country's political and economic situation with all its possible outgrowths, this article indicates the various development prospects relevant to Saudi oil production and its future impacts on the market

  15. Job Prospects for Civil Engineers.

    Science.gov (United States)

    Basta, Nicholas

    1985-01-01

    Government programs and renewed industrial activity have combined with stable enrollments to create bright job prospects for civil engineers. Areas with good opportunities include highway reconstruction and rehabilitation, water-resource management, and new factory construction. The subspecialty of structural engineering has a growing need in…

  16. Scientific knowledge and modern prospecting

    Science.gov (United States)

    Neuerburg, G.J.

    1985-01-01

    Modern prospecting is the systematic search for specified and generally ill-exposed components of the Earth's crust known as ore. This prospecting depends entirely on reliable, or scientific knowledge for guidance and for recognition of the search objects. Improvement in prospecting results from additions and refinements to scientific knowledge. Scientific knowledge is an ordered distillation of observations too numerous and too complex in themselves for easy understanding and for effective management. The ordering of these observations is accomplished by an evolutionary hierarchy of abstractions. These abstractions employ simplified descriptions consisting of characterization by selected properties, sampling to represent much larger parts of a phenomenon, generalized mappings of patterns of geometrical and numerical relations among properties, and explanation (theory) of these patterns as functional relations among the selected properties. Each abstraction is predicated on the mode of abstraction anticipated for the next higher level, so that research is a deductive process in which the highest level, theory, is indispensible for the growth and refinement of scientific knowledge, and therefore of prospecting methodology. ?? 1985 Springer-Verlag.

  17. Subsurface Prospecting by Planetary Drones, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — The proposed program innovates subsurface prospecting by planetary drones to seek a solution to the difficulty of robotic prospecting, sample acquisition, and sample...

  18. Mathematical geology studies of deposit prospect types

    International Nuclear Information System (INIS)

    Liu Guangping

    1998-08-01

    Exact certainty prospect type of uranium deposit, not only can assure the quality of deposit prospects, but also increase economic benefits. Based on the standard of geological prospect of uranium deposit, the author introduces a method of Fuzzy Synthetical Comment for dividing prospect type of uranium deposit. The practical applications demonstrate that the regression accuracy, discriminated by Zadeh operator, of 15 known deposits is 100%

  19. Prospects of the international energy market

    International Nuclear Information System (INIS)

    Schneider, H.K.

    1977-01-01

    The findings of two studies on the international prospects of energy development are discussed: 1) Energy: Global Prospects 1985-2000. Report of the Workshop on Alternative Energy Strategies (WAES) and 2) World Energy Outlook, a recent OECD energy study which is a supplement to the Energy prospects to 1985 study, which was completed in 1974. (UA) [de

  20. Prospects for Future Collider Physics

    CERN Document Server

    Ellis, John

    2016-10-20

    One item on the agenda of future colliders is certain to be the Higgs boson. What is it trying to tell us? The primary objective of any future collider must surely be to identify physics beyond the Standard Model, and supersymmetry is one of the most studied options. it Is supersymmetry waiting for us and, if so, can LHC Run 2 find it? The big surprise from the initial 13-TeV LHC data has been the appearance of a possible signal for a new boson X with a mass ~750 GeV. What are the prospects for future colliders if the X(750) exists? One of the most intriguing possibilities in electroweak physics would be the discovery of non-perturbative phenomena. What are the prospects for observing sphalerons at the LHC or a future collider?

  1. Capital financing in prospective payment.

    Science.gov (United States)

    Oszustowicz, R J; Dreachslin, J L

    1984-03-01

    In the era of prospective payment, arranging financing for hospital capital projects is expected to become even more complicated than under cost-based reimbursement systems. This article outlines the information needed for a bond issue in the prospective payment environment, defines the roles and duties of several external persons and organizations involved with planning a major capital financing, and provides an overview of the entire process. This article assumes for illustrative purposes that a tax-exempt bond issue is going to be used to finance a facility expansion. This method was chosen since over 70% of all major capital financing for hospitals use the tax-exempt bond as the principal vehicle for attracting the necessary debt to finance a major construction project. The tax-exempt bond issue also requires the most detail in documentation and legal provisions.

  2. Prospects for nuclear safety research

    Energy Technology Data Exchange (ETDEWEB)

    Beckjord, E.S.

    1995-04-01

    This document is the text of a paper presented by Eric S. Beckjord (Director, Nuclear Regulatory Research/NRC) at the 22nd Water Reactor Safety Meeting in Bethesda, MD in October 1994. The following topics are briefly reviewed: (1) Reactor vessel research, (2) Probabilistic risk assessment, (3) Direct containment heating, (4) Advanced LWR research, (5) Nuclear energy prospects in the US, and (6) Future nuclear safety research. Subtopics within the last category include economics, waste disposal, and health and safety.

  3. Cosmic Humanity: Utopia, Realities, Prospects

    OpenAIRE

    Sergey Krichevsky

    2017-01-01

    The philosophical foundations of the theory and practice of the creation of cosmic humanity as a process of the evolution of human civilization, the emergence into space, with the prospect of resettlement outside the Earth are considered. There is a connection between myths, fantasies, ideas, concepts and projects aimed at the exploration of outer space, the creation of cosmic humanity. A new and voluminous definition of cosmic humanity in the evolutionary paradigm is given. Cosmic humanity i...

  4. Uranium project. Geochemistry prospection[Study of Uranium geochemical prospection in Uruguay]; Proyecto Uranio. Prospeccion geoquimica

    Energy Technology Data Exchange (ETDEWEB)

    Lambert, J

    1983-07-01

    Geochemistry studies the distribution of the chemicals elements in the terrestrial crust and its ways to migrate. The terminology used in this report is the following one: 1) Principles of the prospection geochemistry 2) Stages of the prospection geochemistry 3)utility of the prospection geochemistry 4) geochemistry of uranium 5) procedures used within the framework of uranium project 6) Average available 7) Selection of the zones of prospection geochemistry 8) Stages of the prospection, Sample preparation and analisis 9) Presentation of the results.

  5. Prospects for oil and gas

    International Nuclear Information System (INIS)

    Laherrere, J.

    2011-01-01

    It was five years ago, in January 2006, that Futuribles devoted a major special issue (no. 315) to energy prospects and the greenhouse effect. That was already a time of great concern about this question and several articles offered analyses of the gloomy prospects for the development of energy resources and the issues around climate change. Among these, an article by Jean Laherrere outlined the prospects for oil resources, showing the extent to which information in this area was disparate, unreliable and even questionable, being often highly political. As one of the more pessimistic writers on the question, Laherrere reminded us of the imminence of 'peak oil' (the prelude to a decline in global oil production) and the need to re-think our styles of consumption to adapt to a new age in which, as energy becomes scarcer, it will be increasingly expensive. Five years later, Jean Laherrere returns to the columns of Futuribles on the occasion of a new special issue on energy and the climate, to update us on the global prospects for oil and gas production. He begins by recalling how politically slanted and unreliable information in this area can be, depending on its source, the units of measurement employed etc. He stresses, too, that in the view of many experts peak oil was reached in 2006 and the situation is currently plateau-ing, just ahead of a decline in oil production (gradual or sudden, depending on whether measures of economic constraint are implemented). For its part, gas production should peak around 2025-2030. Jean Laherrere specifies what reserves remain, how these are currently exploited and marketed, and the prospects that ensue in the longer term (he also shows how wrong gas-price forecasts have been in the past). As he stresses, in conclusion, with both oil and gas we must be aware that the world does not have infinite resources and, since the alternatives do not allow us, at the moment, to make up for future energy-resource shortages, it is for

  6. Prospective

    International Nuclear Information System (INIS)

    Wagner, H.N. Jr.

    1984-01-01

    All living systems are characterized by an S-shaped growth curve, representing a lag phase, a phase of exponential growth and a plateau. Nuclear medicine is no exception. In one sense, medical imaging modalities, such as plain film and contrast studies, computerized tomography (CT), ultrasound, digital subtraction angiography, conventional nuclear imaging, and PET, are competitive. They compete for space, funds, people, enthusiasm, and interest. For example, in the 1970s the use of radionuclide brain scans dropped sharply in hospitals when CT became available; ultrasound and nuclear medicine studies of the biliary system led to a significant decrease in the use of oral cholecystograpy and intravenous cholangiography. Some predict that nuclear magnetic resonance (NMR) and digital radiography may have a significant impact on CT scanning by 1990, because current NMR images are comparable in anatomic resolution to CT without bone artifacts and, especially important in the 1980s, without ionizing radiation. In the face of all this competition, the continued growth and well-being of the field of nuclear medicine will depend on the degree to which the field can adapt itself to the changing circumstances of medical practice and research in the 1980s. The forces that will shape the future of nuclear medicine will continue to come from both within and outside the field

  7. PROSPECTS

    African Journals Online (AJOL)

    which is their second foreign language after English. This paper, seeks to ... taught, but very little has been done beyond the teaching and learning of French as an ... condemns the attitude of Blacks at home and abroad who defraud those who ...

  8. Prospects of uranium in Baluchistan

    International Nuclear Information System (INIS)

    Aslam, M.; Rehman, M.A.

    1981-01-01

    A review of the geology of Baluchistan indicates that sedimentary rocks consisting of sandstones and conglomerates ranging from Paleocene to Miocene age were formed under the fluviatile conditions. The region underwent Late Cretaceous-Early Cenozic continent to continent collision resulting in varied metallogenic environments. Considering the criteria of favourability for the environments of uranium deposition, it is found that these rocks and the acidicigneous rocks of Cretaceous age are favourable for the occurrence of uranium. A radiometric prospecting programme is suggested to locate possible mineralization in the region. (author)

  9. Prospects for inherently safe reactors

    International Nuclear Information System (INIS)

    Barkenbus, J.N.

    1988-01-01

    Public fears over nuclear safety have led some within the nuclear community to investigate the possibility of producing inherently safe nuclear reactors; that is, reactors that are transparently incapable of producing a core melt. While several promising designs of such reactors have been produced, support for large-scale research and development efforts has not been forthcoming. The prospects for commercialization of inherently safe reactors, therefore, are problematic; possible events such as further nuclear reactor accidents and superpower summits, could alter the present situation significantly. (author)

  10. Renewable energy prospects for implementation

    CERN Document Server

    Jackson, Tim

    1993-01-01

    Renewable Energy: Prospects for Implementation contains papers that were originally commissioned by the journal Energy Policy for a series on renewable energy appearing between January 1991 to September 1992. In view of the fast-changing demands on conventional energy supply to meet environmental imperatives, it seemed timely to reproduce here a selection of those papers with a new introduction and a revised concluding chapter by the Editor of the series, Dr Tim Jackson, a research fellow with the Stockholm Environment Institute. The book is organized into four parts. The papers in Part I

  11. Prospects for alternative Fusion Fuels

    International Nuclear Information System (INIS)

    Glancy, J.

    1986-01-01

    The author has worked on three different magnetic confinement concepts for alternate fusion fueled reactors: tokamaks; tanden mirrors, and reversed field pinches. The focus of this article is on prospects for alternate fusion fuels as the author sees them relative to the other choices: increased numbers of coal plants, fission reactors, renewables, and D-T fusion. Discussion is limited on the consideration of alternate fusion fuels to the catalyzed deuterium-deuterium fuel cycle. Reasons for seeking an alternate energy source are cost, a more secure fuel supply, environmental impact and safety. The technical risks associated with development of fusion are examined briefly

  12. Lattice QCD: Status and Prospect

    International Nuclear Information System (INIS)

    Ukawa, Akira

    2006-01-01

    A brief review is given of the current status and near-future prospect of lattice QCD studies of the Standard Model. After summarizing a bit of history, we describe current attempts toward inclusion of dynamical up, down and strange quarks. Recent results on the light hadron mass spectrum as well as those on the heavy quark quantities are described. Recent work on lattice pentaquark search is summarized. We touch upon the PACS-CS Project for building our next machine for lattice QCD, and conclude with a summary of computer situation and the physics possibilities over the next several years

  13. A test of prospect theory.

    Science.gov (United States)

    Feeny, David; Eng, Ken

    2005-01-01

    Prospect theory (PT) hypothesizes that people judge states relative to a reference point, usually assumed to be their current health. States better than the reference point are valued on a concave portion of the utility function; worse states are valued on a convex portion. Using prospectively collected utility scores, the objective is to test empirically implications of PT. Osteoarthritis (OA) patients undergoing total hip arthroplasty periodically provided standard gamble scores for three OA hypothetical states describing mild, moderate, and severe OA as well as their subjectively defined current state (SDCS). Our hypothesis was that most patients improved between the pre- and postsurgery assessments. According to PT, scores for hypothetical states previously > SDCS but now < SDCS should be lower at the postsurgery assessment. Fourteen patients met the criteria for testing the hypothesis. Predictions were confirmed for 0 patients; there was no change or mixed results for 6 patients (42.9 percent); and scores moved in the direction opposite to that predicted by PT for 8 patients (57.1 percent). In general, the direction and magnitude of the changes in hypothetical-state scores do not conform to the predictions of PT.

  14. Randomized, interventional, prospective, comparative study to ...

    African Journals Online (AJOL)

    Randomized, interventional, prospective, comparative study to evaluate the antihypertensive efficacy and tolerability of ramipril versus telmisartan in stage 1 hypertensive patients with diabetes mellitus.

  15. Feasibility of low-dose contrast medium high pitch CT angiography for the combined evaluation of coronary, head and neck arteries.

    Directory of Open Access Journals (Sweden)

    Zhiwei Wang

    Full Text Available PURPOSE: To evaluate the image quality and radiation dose of combined heart, head, and neck CT angiography (CTA using prospectively electrocardiography (ECG-triggered high-pitch spiral scan protocol, compared with single coronary CTA. MATERIALS AND METHODS: 151 consecutive patients were prospectively included and randomly divided into three groups. Group 1 (n = 47 underwent combined heart, neck, and head CTA using prospectively ECG-triggered high-pitch spiral (Flash scan protocol with a single-phase intravenous injection of iodinated contrast and saline flush; Group 2 (n = 51 underwent single coronary CTA with Flash scan protocol; and Group 3 (n = 53 underwent single coronary CTA with prospective sequence scan protocol. All patients were examined on a dual source CT (Definition FLASH. The image quality was determined for each CT study. RESULTS: Patients of scanning protocol Group 1, 2, and 3 showed no significant differences in age, sex, heart rates, and BMI. Evaluation of coronary artery image quality showed comparable results in the three scanning protocol groups on a per patient-based analysis. In group 1, image quality was found to be sufficient to be diagnostic in all arterial segments of carotid arteries. The mean dose-length product (DLP for group 1 was 256.3±24.5 mGy×cm and was significantly higher in comparison with group 2 (93.4±19.9 mGy×cm; p < 0.001. However, there was no significant difference of DLP between group 1 and group 3 (254.1±69.9 mGy×cm. CONCLUSIONS: The combined heart, neck, and head arteries scan using prospectively electrocardiography (ECG-triggered high-pitch spiral scan protocol in 1 single examination resulted in an excellent opacification of the aorta, the carotid arteries, and the coronary arteries and provided a good image quality with low radiation dose.

  16. Kenaf: its prospect in Indonesia

    Directory of Open Access Journals (Sweden)

    Estri Laras Arumingtyas

    2015-09-01

    Full Text Available Kenaf is a plant fibre with high potential as source of material industry. Originally, kenaf usage in Indonesia is still limited only for jute sacks material, which is then displaced by plastic sacks production. While at international scale, kenaf has been started to be developed as pulp material, polypropylene composite, fibreglass replacement, and particle board for automotive industry materials. Indonesia is a tropical country this condition which suitable for kenaf cultivation. However, research reports about kenaf potential usages are still few and limited in domestic level only. Whereas, Indonesian kenaf plant information is needed by international community to understand comprehensively about the potential of tropical plants. This article aims to provide an overview about kenaf cultivation potential and usages in Indonesia as well as the possibility of future development. Key words: kenaf, fibre, prospect, potential.

  17. Radiation detectors: needs and prospects

    International Nuclear Information System (INIS)

    Armantrout, G.A.

    1981-01-01

    Important applications for x- and γ-ray spectroscopy are found in prospecting, materials characterization, environmental monitoring, the life sciences, and nuclear physics. The specific requirements vary for each application with varying degrees of emphasis on either spectrometer resolution, detection efficiency, or both. Since no one spectrometer is ideally suited to this wide range of needs, compromises are usually required. Gas and scintillation spectrometers have reached a level of maturity, and recent interest has concentrated on semiconductor spectrometers. Germanium detectors are showing continuing refinement and are the spectrometers of choice for high resolution applications. The new high-Z semiconductors, such as CdTe and HgI 2 , have shown steady improvement but are limited in both resolution and size and will likely be used only in applications which require their unique properties

  18. Nuclear cooperation: challenges and prospects

    International Nuclear Information System (INIS)

    Ollapally, Deepa; Rajagopal, S.

    1997-01-01

    In this era of globalisation and technology flows, the nuclear field continues to retain strong barriers to international collaboration. From nuclear energy to non-proliferation however, the potential for concerted action exists. The International and Strategic Studies Unit of the National Institute of Advanced Studies (NIAS) held a two day seminar exploring the challenges and prospects for achieving mutual cooperation between states relating to all aspects of nuclear technology. This volume is based on the proceedings of the seminar. The broad themes that the seminar considered included disarmament and the security link; implementation and verification of nonproliferation regimes; transfer of technology and nuclear energy. The seminar culminated with a round table on confidence building

  19. Radioactive wastes. Management prospects. Appendixes

    International Nuclear Information System (INIS)

    Guillaumont, R.

    2003-01-01

    These appendixes complete the article BN3661 entitled 'Radioactive wastes. Management prospects'. They develop the principles of the different separation processes under study and make a status of the conditioning matrices that are envisaged: 1 - principles of advanced separation (separation of U, Np, Pu, Tc and I; separation of Am and Cm in two extraction steps (Diamex and Sanex processes); separation of Am and Cm in a single extraction step (Paladin process); separation of Am and Cm (Sesame process); separation of Cs (Calixarene process); 2 - principles of separation in pyro-chemistry: separation under inert atmosphere (non-oxidizing); separation in oxidizing conditions; 3 - conditioning matrices under study for separate elements: objectives and methodology, matrices for iodine, for cesium and for actinides. (J.S.)

  20. Prospective outcomes of injury study.

    Science.gov (United States)

    Derrett, S; Langley, J; Hokowhitu, B; Ameratunga, S; Hansen, P; Davie, G; Wyeth, E; Lilley, R

    2009-10-01

    In New Zealand (NZ), 20% of adults report a disability, of which one-third is caused by injury. No prospective epidemiological studies of predictors of disability following all-cause injury among New Zealanders have been undertaken. Internationally, studies have focused on a limited range of predictors or specific injuries. Although these studies provide useful insights, applicability to NZ is limited given the importance of NZ's unique macro-social factors, such as NZ's no-fault accident compensation and rehabilitation scheme, the Accident Compensation Corporation (ACC). (1) To quantitatively determine the injury, rehabilitation, personal, social and economic factors leading to disability outcomes following injury in NZ. (2) To qualitatively explore experiences and perceptions of injury-related outcomes in face-to-face interviews with 15 Māori and 15 other New Zealanders, 6 and 12 months after injury. Four geographical regions within NZ. Prospective cohort study with telephone interviews 1, 4 and 12 months after injury. 2500 people (including 460 Māori), aged 18-64 years, randomly selected from ACC's entitlement claims register (people likely to be off work for at least 1 week or equivalent). Telephone interviews, electronic hospital and ACC injury data. Exposures include demographic, social, economic, work-related, health status, participation and/or environmental factors. Primary: disability (including WHODAS II) and health-related quality of life (including EQ-5D). Secondary: participation (paid and unpaid activities), life satisfaction and costs. Separate regression models will be developed for each of the outcomes. Repeated measures outcomes will be modelled using general estimating equation models and generalised linear mixed models.

  1. Prospective Elemantary Science Teachers' Epistemological Beliefs

    Science.gov (United States)

    Macaroglu Akgul, Esra; Oztuna Kaplan, Aysun

    2009-01-01

    This research study examined "prospective elementary science teachers' epistemological beliefs". Forty-nine prospective elementary science teachers participated into research. The research was designed in both quantitative and qualitative manner, within the context of "Special Methods in Science Teaching I" course.…

  2. Prospective Teachers' Personal Characteristics to Multicultural Education

    Science.gov (United States)

    Eskici, Menekse

    2016-01-01

    The aim of this paper is to determine prospective teachers' personal characteristics to multicultural education. It is also aimed to reveal whether there are meaningful differences in prospective teachers' personal characteristics to multicultural education according to their genders, age and number of siblings. The descriptive model was chosen to…

  3. Functional correlates of prospective memory in stroke

    NARCIS (Netherlands)

    Kant, N.; Van den Berg, E.; van Zandvoort, M.J.E.; Frijns, C.J.M.; Kappelle, L.J.; Postma, A.

    2014-01-01

    NTRODUCTION: Prospective memory is the ability to remember actions to be performed later in time or when a certain event occurs. Multiple cognitive processes are involved in prospective memory, and the degree to which automatic or effortful processes are involved may differ for different types of

  4. Perceptions of Prospective Teachers about Tolerance Education

    Science.gov (United States)

    Sahin, Cavus

    2011-01-01

    The purpose of this study is to ascertain the perceptions of prospective teachers about tolerance education. This research is a descriptive, qualitative study. A semi-structured and non-directive interview technique is used for collecting data. Research is carried out with 30 prospective teachers who attend Canakkale Onsekiz Mart University…

  5. Status and development of uranium prospection methods

    International Nuclear Information System (INIS)

    Barthel, F.

    1978-01-01

    In radiometric prospection, gamma measuring equipment is widely used. Simple instruments, so-called scintillometers, can only measure total radiation while spectrometers permit separate measurements of uranium, thorium, or calcium via daughter products of their decay chains. Depending on the target investigated, airborne, carborne, or footborne methods are employed. In radon prospection the gaseous decay product radon is measured as a sign of hidden uranium enrichment in ground air or water from springs. Due to its high solubility, uranium is well suited for geochemical prospection where uranium concentrations in bodies of water, river sediments, soil and rock types are determined. There is a trend in uranium prospection towards the discovery of hidden orifications. Novel techniques, e.g. airborne geochemistry, isotope chemistry, tracer element measurement, etc. are being tested with a view to their suitability for uranium prospection. (orig./HP) 891 HP/orig.- 892 MKO [de

  6. Antiaging therapy: a prospective hypothesis

    Directory of Open Access Journals (Sweden)

    Shahidi Bonjar MR

    2015-01-01

    Full Text Available Mohammad Rashid Shahidi Bonjar,1 Leyla Shahidi Bonjar2 1School of Dentistry, Kerman University of Medical Sciences, Kerman Iran; 2Department of Pharmacology, College of Pharmacy, Kerman University of Medical Sciences, Kerman, Iran Abstract: This hypothesis proposes a new prospective approach to slow the aging process in older humans. The hypothesis could lead to developing new treatments for age-related illnesses and help humans to live longer. This hypothesis has no previous documentation in scientific media and has no protocol. Scientists have presented evidence that systemic aging is influenced by peculiar molecules in the blood. Researchers at Albert Einstein College of Medicine, New York, and Harvard University in Cambridge discovered elevated titer of aging-related molecules (ARMs in blood, which trigger cascade of aging process in mice; they also indicated that the process can be reduced or even reversed. By inhibiting the production of ARMs, they could reduce age-related cognitive and physical declines. The present hypothesis offers a new approach to translate these findings into medical treatment: extracorporeal adjustment of ARMs would lead to slower rates of aging. A prospective “antiaging blood filtration column” (AABFC is a nanotechnological device that would fulfill the central role in this approach. An AABFC would set a near-youth homeostatic titer of ARMs in the blood. In this regard, the AABFC immobilizes ARMs from the blood while blood passes through the column. The AABFC harbors antibodies against ARMs. ARM antibodies would be conjugated irreversibly to ARMs on contact surfaces of the reaction platforms inside the AABFC till near-youth homeostasis is attained. The treatment is performed with the aid of a blood-circulating pump. Similar to a renal dialysis machine, blood would circulate from the body to the AABFC and from there back to the body in a closed circuit until ARMs were sufficiently depleted from the blood. The

  7. Geochemical methodology for gold prospect ion in Uruguay

    International Nuclear Information System (INIS)

    Spangenber, J.

    1987-01-01

    This work is about the history of gold prospection in Uruguay. In this study there are considered the geochemical aspects, the gold performance, the applicability to mining prospection and the gold prospection aluvionar

  8. Prospects for Tokamak Fusion Reactors

    International Nuclear Information System (INIS)

    Sheffield, J.; Galambos, J.

    1995-01-01

    This paper first reviews briefly the status and plans for research in magnetic fusion energy and discusses the prospects for the tokamak magnetic configuration to be the basis for a fusion power plant. Good progress has been made in achieving fusion reactor-level, deuterium-tritium (D-T) plasmas with the production of significant fusion power in the Joint European Torus (up to 2 MW) and the Tokamak Fusion Test Reactor (up to 10 MW) tokamaks. Advances on the technologies of heating, fueling, diagnostics, and materials supported these achievements. The successes have led to the initiation of the design phases of two tokamaks, the International Thermonuclear Experimental Reactor (ITER) and the US Toroidal Physics Experiment (TPX). ITER will demonstrate the controlled ignition and extended bum of D-T plasmas with steady state as an ultimate goal. ITER will further demonstrate technologies essential to a power plant in an integrated system and perform integrated testing of the high heat flux and nuclear components required to use fusion energy for practical purposes. TPX will complement ITER by testing advanced modes of steady-state plasma operation that, coupled with the developments in ITER, will lead to an optimized demonstration power plant

  9. Dual Pathways to Prospective Remembering

    Directory of Open Access Journals (Sweden)

    Mark A Mcdaniel

    2015-07-01

    Full Text Available According to the multiprocess framework (McDaniel & Einstein, 2000, the cognitive system can support prospective memory (PM retrieval through two general pathways. One pathway depends on top-down attentional control processes that maintain activation of the intention and/or monitor the environment for the triggering or target cues that indicate that the intention should be executed. A second pathway depends on (bottom-up spontaneous retrieval processes, processes that are often triggered by a PM target cue; critically spontaneous retrieval is assumed to not require monitoring or active maintenance of the intention. Given demand characteristics associated with experimental settings, however, participants are often inclined to monitor, thereby potentially masking discovery of bottom-up spontaneous retrieval processes. In this article, we discuss parameters of laboratory PM paradigms to discourage monitoring and review recent behavioral evidence from such paradigms that implicate spontaneous retrieval in PM. We then re-examine the neuro-imaging evidence from the lens of the multiprocess framework and suggest some critical modifications to existing neuro-cognitive interpretations of the neuro-imaging results. These modifications illuminate possible directions and refinements for further neuro-imaging investigations of PM.

  10. Dual pathways to prospective remembering

    Science.gov (United States)

    McDaniel, Mark A.; Umanath, Sharda; Einstein, Gilles O.; Waldum, Emily R.

    2015-01-01

    According to the multiprocess framework (McDaniel and Einstein, 2000), the cognitive system can support prospective memory (PM) retrieval through two general pathways. One pathway depends on top–down attentional control processes that maintain activation of the intention and/or monitor the environment for the triggering or target cues that indicate that the intention should be executed. A second pathway depends on (bottom–up) spontaneous retrieval processes, processes that are often triggered by a PM target cue; critically, spontaneous retrieval is assumed not to require monitoring or active maintenance of the intention. Given demand characteristics associated with experimental settings, however, participants are often inclined to monitor, thereby potentially masking discovery of bottom–up spontaneous retrieval processes. In this article, we discuss parameters of laboratory PM paradigms to discourage monitoring and review recent behavioral evidence from such paradigms that implicate spontaneous retrieval in PM. We then re-examine the neuro-imaging evidence from the lens of the multiprocess framework and suggest some critical modifications to existing neuro-cognitive interpretations of the neuro-imaging results. These modifications illuminate possible directions and refinements for further neuro-imaging investigations of PM. PMID:26236213

  11. [Prospective study in 2 hospitals].

    Science.gov (United States)

    Jiménez-Buñuales, M T; Martínez-Sáenz, M S; González-Diego, P; Vallejo-García, M; Gallardo-Anciano, J; Cestafe-Martínez, A

    2016-06-01

    The purpose of this study is to know the incidence rate of medication reconciliation at admission and discharge in patients of La Rioja and to improve the patient safety on medication reconciliation. An observational prospective study, part of the Joint Action PaSQ, Work Package 5, European Union Network for Patient Safety and Quality of Care. The study has taken into account the definitions of the Institute for Safe Medication Practices. Any unintended discrepancy in medication between chronic treatment and the treatment prescribed in the hospital was considered as a reconciliation error. A total of 750 patients were included, 9 (1.2%) of whom showed at least one discrepancy. The patients had a total of 3,156 mediations registered: 2,313 prescriptions (73.4%) showed no differences, while 821 prescriptions (26%) were intended discrepancies and 21 prescriptions (0.6%) unintended discrepancies were considered by the physician as reconciliation errors. A percentage of 1.2 of the patients, which represents 0.6% of the medicines (one in 166 medications registered) had reconciliation errors during their hospital stay. A proceeding has been implemented by means of the physician doing the medication reconciliation and reviewing it with the help of a medication reconciliation form. The medication reconciliation is a priority strategic objective to improve the safety of patients. Copyright © 2016 SECA. Published by Elsevier Espana. All rights reserved.

  12. Prospects of Single Tax Payers

    Directory of Open Access Journals (Sweden)

    Tofan Ivan M.

    2014-03-01

    Full Text Available The article speaks about problem aspects of taxation, which were set by the state for the single tax administering due to permanent and system changes in the tax legislation. It shows the necessity of search for alternative methods of administering in the process of taxation of single tax payers by fiscal services. The goal of the article is the study of prospects of further taxation of entrepreneurs – single tax payers on the basis of analysis of conditions and principles created by the state for the business. The article used methods of system analysis, comparison, forecasting and modelling. It analyses the process of evolution of the simplified taxation system, accounting and reporting from the moment of its adoption until today. The article presents the structure of the quantitative composition of single tax payers depending on the selected groups. It marks out and characterises administrative and fiscal factors that do not facilitate further development of entrepreneurship in Ukraine. In the result of the conducted studies the article outlines problem aspects of organisation of taxation of the small business and offers specific and real ways of their overcoming or partial solution.

  13. Prospects of geothermal resource exploitation

    International Nuclear Information System (INIS)

    Bourrelier, P.H.; Cornet, F.; Fouillac, C.

    1994-01-01

    The use of geothermal energy to generate electricity has only occurred during the past 50 years by drilling wells in aquifers close to magmas and producing either dry steam or hot water. The world's production of electricity from geothermal energy is over 6000 MWe and is still growing. The direct use of geothermal energy for major urban communities has been developed recently by exploitation of aquifers in sedimentary basins under large towns. Scaling up the extraction of heat implies the exploitation of larger and better located fields requiring an appropriate method of extraction; the objective of present attempts in USA, Japan and Europe is to create heat exchangers by the circulation of water between several deep wells. Two field categories are considered: the extension of classical geothermal fields beyond the aquifer areas, and areas favoured by both a high geothermal gradient, fractures inducing a natural permeability at large scale, and good commercial prospects (such as in the Rhenan Graben). Hot dry rocks concept has gained a large interest. 1 fig., 5 tabs., 11 refs

  14. Soap production: A green prospective.

    Science.gov (United States)

    Félix, Sandra; Araújo, Joana; Pires, Ana Maria; Sousa, Ana Cláudia

    2017-08-01

    A green prospective based on the reuse of waste materials such as almond shells, orange peel and used cooking oil to manufacture soap is presented. In Portugal, thousands of tons of waste are generated from used cooking oil and production of nut shells' residues is growing every year. In addition, the high consumption of citrus fruits, oranges in particular, generates large amounts of citrus peel. Therefore, it is necessary to diversify reuse mechanisms of these wastes, in order to make them back into raw materials. Complying with this trend, this work was carried out by processing and grinding almond shells, treating used oil, processing orange peels and extracting limonene, formulating and producing soap, and performing an acceptance study of the final product. Results validated a high potential of the idea in the field of environmental education, so it can be replicated in practical classes. It can also be useful for waste management, and it can support the development of community projects on an ecological approach. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Status and prospects for reprocessing

    International Nuclear Information System (INIS)

    Rossney, G.K.

    1977-01-01

    Following the formation of United Reprocessors (U.R.G.) in 1976 by British Nuclear Fuels Limited (B.N.F.L.) in the United Kingdom, the Commissariat a l'Energie Atomique (C.E.A.) in France and K.E.W.A. Kernbrennstoff-Wiederaufarbeitungs-Gesellschaft MBH (K.E.W.A.) in Germany, collaboration is now well established for the marketing of their reprocessing services for irradiated oxide fuel from thermal reactors. In addition collaboration in the continued evolution of the technology has progressed and an extensive research and development programme has been established, the results of which are exchanged between the shareholders. During 1976 the U.K. Government has given approval to B.N.F.L. to sign further contracts with foreign customers, subject to certain conditions. In France, the fuel cycle activities of the C.E.A. have been vested in a new company (Compagnie Generale Des Matieres Nucleaires (C.O.G.E.M.A.)) and their La Hague plant has commenced reprocessing operations on irradiated oxide fuel. In Germany, an agreement has been signed between K.E.W.A. and P.W.K. for the pre-project study for the proposed German plant. Against this background this paper reviews the present status of reprocessing by the shareholders of U.R.G. and the prospects for reprocessing

  16. Jojoba: an assessment of prospects

    Energy Technology Data Exchange (ETDEWEB)

    Walters, P.R.; MacFarlane, W.; Spensley, P.C.

    1979-01-01

    Jojoba (Simmondsia chinensis) is a crop that might be cultivated profitably in the arid and semi-arid zones of certain cultivated profitably in the arid and semi-arid zones of certain developing countries. This report assesses the present state of research on the crop and gives an opinion as to its prospects of being of economic benefit to these areas. The report is divided into five sections. In Section 1 the plant and its natural habitats are described and current research and the problems to be overcome in cultivating the crop are outlined. In Section 2 the chemistry of jojoba and other waxes is discussed. In Section 3 consideration is given to the end-use potential of jojoba and an attempt is made to forecast the future market demand and price for jojoba oil, both as a liquid and as a solid wax. In Section 4 the economics of jojoba production are discussed in light of the findings in the earlier sections. Finally, in Section 5, the wider aspects of plant introductions are considered briefly and conclusions drawn regarding jojoba's potential and its future research needs. It will be essential to increase jojoba yield significantly before cultivation will be viable except on a small scale. A satisfactory mechanized harvesting system also needs to be developed. The market for jojoba oil at various levels of production is estimated at production of less than 1000 tons (pounds-sterling 5500- pounds-sterling 7700 per ton); production of 2000 to 5000 tons (pounds-sterling 900- pounds-sterling 950 per ton); and production up to 20,000 tons (pounds-sterling 500-pounds-sterling 600 per ton).

  17. Energy intensities: Prospects and potential

    International Nuclear Information System (INIS)

    Anon.

    1992-01-01

    In the previous chapter, the author described how rising activity levels and structural change are pushing toward higher energy use in many sectors and regions, especially in the developing countries. The extent to which more activity leads to greater energy use will depend on the energy intensity of end-use activities. In this chapter, the author presents an overview of the potential for intensity reductions in each sector over the next 10-20 years. It is not the author's intent to describe in detail the various technologies that could be employed to improve energy efficiency, which has been done by others (see, for example, Lovins ampersand Lovins, 1991; Goldembert et al., 1987). Rather, he discusses the key factors that will shape future energy intensities in different parts of the world, and gives a sense for the changes that could be attained if greater attention were given to accelerate efficiency improvement. The prospects for energy intensities, and the potential for reduction, vary among sectors and parts of the world. In the majority of cases, intensities are tending to decline as new equipment and facilities come into use and improvements are made on existing stocks. The effect of stock turnover will be especially strong in the developing countries, where stocks are growing at a rapid pace, and the Former East Bloc, where much of the existing industrial plant will eventually be retired and replaced with more modern facilities. While reductions in energy intensity are likely in most areas, there is a large divergence between the technical and economic potential for reducing energy intensities and the direction in which present trends are moving. In the next chapter, the author presents scenarios that illustrate where trends are pointing, and what could be achieved if improving energy efficiency were a focus of public policies. 53 refs., 4 figs., 2 tabs

  18. Prospective Optimization with Limited Resources.

    Science.gov (United States)

    Snider, Joseph; Lee, Dongpyo; Poizner, Howard; Gepshtein, Sergei

    2015-09-01

    The future is uncertain because some forthcoming events are unpredictable and also because our ability to foresee the myriad consequences of our own actions is limited. Here we studied how humans select actions under such extrinsic and intrinsic uncertainty, in view of an exponentially expanding number of prospects on a branching multivalued visual stimulus. A triangular grid of disks of different sizes scrolled down a touchscreen at a variable speed. The larger disks represented larger rewards. The task was to maximize the cumulative reward by touching one disk at a time in a rapid sequence, forming an upward path across the grid, while every step along the path constrained the part of the grid accessible in the future. This task captured some of the complexity of natural behavior in the risky and dynamic world, where ongoing decisions alter the landscape of future rewards. By comparing human behavior with behavior of ideal actors, we identified the strategies used by humans in terms of how far into the future they looked (their "depth of computation") and how often they attempted to incorporate new information about the future rewards (their "recalculation period"). We found that, for a given task difficulty, humans traded off their depth of computation for the recalculation period. The form of this tradeoff was consistent with a complete, brute-force exploration of all possible paths up to a resource-limited finite depth. A step-by-step analysis of the human behavior revealed that participants took into account very fine distinctions between the future rewards and that they abstained from some simple heuristics in assessment of the alternative paths, such as seeking only the largest disks or avoiding the smaller disks. The participants preferred to reduce their depth of computation or increase the recalculation period rather than sacrifice the precision of computation.

  19. Prospective Optimization with Limited Resources.

    Directory of Open Access Journals (Sweden)

    Joseph Snider

    2015-09-01

    Full Text Available The future is uncertain because some forthcoming events are unpredictable and also because our ability to foresee the myriad consequences of our own actions is limited. Here we studied how humans select actions under such extrinsic and intrinsic uncertainty, in view of an exponentially expanding number of prospects on a branching multivalued visual stimulus. A triangular grid of disks of different sizes scrolled down a touchscreen at a variable speed. The larger disks represented larger rewards. The task was to maximize the cumulative reward by touching one disk at a time in a rapid sequence, forming an upward path across the grid, while every step along the path constrained the part of the grid accessible in the future. This task captured some of the complexity of natural behavior in the risky and dynamic world, where ongoing decisions alter the landscape of future rewards. By comparing human behavior with behavior of ideal actors, we identified the strategies used by humans in terms of how far into the future they looked (their "depth of computation" and how often they attempted to incorporate new information about the future rewards (their "recalculation period". We found that, for a given task difficulty, humans traded off their depth of computation for the recalculation period. The form of this tradeoff was consistent with a complete, brute-force exploration of all possible paths up to a resource-limited finite depth. A step-by-step analysis of the human behavior revealed that participants took into account very fine distinctions between the future rewards and that they abstained from some simple heuristics in assessment of the alternative paths, such as seeking only the largest disks or avoiding the smaller disks. The participants preferred to reduce their depth of computation or increase the recalculation period rather than sacrifice the precision of computation.

  20. The prospect of conventional disarmament

    International Nuclear Information System (INIS)

    Adeniji, O.

    1989-01-01

    The prospect of conventional disarmament in Europe holds out great consequences not only for the continent but also for the entire world. The arms race both in its nuclear and conventional aspects has been the single most important element of the destabilizing factors in international relations since 1945. Though initially borne out of the ideological division of Europe and the consequent quest for strategic military superiority, it soon developed a technological momentum of its own, becoming more the cause than the effect of the distrust in the relationship of the two alliances. The issue of conventional weapons was raised for negotiations side by side with that of nuclear weapons when the United Nations took up the question of disarmament in 1946. Due, however, to the unforeseen and most dangerous advance in nuclear weaponry, the fear engendered shifted all attention at the multilateral level to nuclear weapons. Except in Europe where the Mutual and Balanced Force Reduction Talks in Central Europe were initiated, conventional weapons disarmament did not attract multilateral attention again until the First Special Session of the United nations General Assembly Devoted to Disarmament in 1978. The Final Document of the Special Session did accord highest priority to negotiations on nuclear weapons. However, it also affirmed that side by side with negotiations on nuclear weapons, the limitation and gradual reduction of armed forces and conventional weapons should be resolutely pursued within the framework of general and complete disarmament. States with the largest military arsenals, it was stated, had a special responsibility in pursuing conventional armaments reduction. Underscoring the central role of Europe further, the Final Document postulated that the achievement of a more stable situation at a lower level of military potential would contribute toward strengthening of security in Europe and constitute a significant step toward international peace and security

  1. Cosmic Humanity: Utopia, Realities, Prospects

    Directory of Open Access Journals (Sweden)

    Sergey Krichevsky

    2017-07-01

    Full Text Available The philosophical foundations of the theory and practice of the creation of cosmic humanity as a process of the evolution of human civilization, the emergence into space, with the prospect of resettlement outside the Earth are considered. There is a connection between myths, fantasies, ideas, concepts and projects aimed at the exploration of outer space, the creation of cosmic humanity. A new and voluminous definition of cosmic humanity in the evolutionary paradigm is given. Cosmic humanity is (essence and 4 stages of evolution: 1. Humanity living on Earth, sensing, knowing, understanding its cosmic origin, relationship with the cosmos and cosmic destiny. 2. Humanity living on Earth, leading aerospace activity for the purposes of exploration and use of aerospace space (Heaven, Space for survival and development. 3. Humanity living on Earth and outside the Earth — in the solar system, preserving the Earth and mastering the Cosmos for survival and development. 4. Humanity, settled and living in the Cosmos. Now humanity is in the process of transition from the second to the third stage. In the process of this evolution, a complex transformation of man and society takes place. The problem-semantic field of cosmic humanity is described and its general model is presented. The meta-goal-setting is the justification of cosmic humanity with the application of the anthropic principle and its “active” super (post anthropic supplement: “Cosmic humanity has an evolutionary purpose to actively manage evolution: change man, humanity and the universe.” The evolution of the “cosmic dream”, goals and technologies of space activities is formalized in the form of a conceptual model. Challenges and negative trends are considered in connection with the crisis of space activity, criticism and attempts to limit the flights of people into space. The prototype of cosmic humanity, its basis and acting model is the cosmonauts’ community. The main

  2. Procreative beneficence and the prospective parent.

    Science.gov (United States)

    Herissone-Kelly, P

    2006-03-01

    Julian Savulescu has given clear expression to a principle-that of "procreative beneficence"-which underlies the thought of many contemporary writers on bioethics. The principle of procreative beneficence (PPB) holds that parents or single reproducers are at least prima facie obliged to select the child, out of a range of possible children they might have, who will be likely to lead the best life. My aim in this paper is to argue that prospective parents, just by dint of their being prospective parents, are in fact not obliged to act on PPB. That is, there is something about their filling the role of prospective parents that exempts them from selecting the child with the best life. I urge that it is more realistic to view prospective parents as bound by a principle of acceptable outlook, which holds that they ought not to select children whose lives will contain an unacceptable amount of suffering.

  3. Current status and prospects for Chernobyl Ukritiye

    International Nuclear Information System (INIS)

    Jampsin, B.

    1996-01-01

    Current status and prospects for Chernobyl Ukritiye (sarcophagus) are described, including the following issues: the accident; the sarcophagus; the radioactive inventory; the design basis criteria; the analysis of the present state; a way forward

  4. Caolines Program. N1 area prospective soundings

    International Nuclear Information System (INIS)

    Coronel, N.; Mari, C.

    1984-01-01

    This work is about The Caolines program. After several stages was designed a network of drilling to be developed in prospective areas. The support of this network was a geological cartography performed in a devonian region.

  5. BIO PROSPECTING IN NIGERIA: EVALUATING THE ADEQUACY ...

    African Journals Online (AJOL)

    in strategic planning and policy formulation on bio prospecting, amongst ... into the challenging field of exploring biological diversity for commercially ...... sions of these regulations, such body corporate, or any person who was purporting to act.

  6. Technical development of seismic imaging prospecting

    International Nuclear Information System (INIS)

    Xu Guilai

    2006-01-01

    Geophysical methods and apparatus for shallow engineering geophysical prospecting and mining related in-roadway geophysical prospecting are important research fields which has been studied for long time, unfortunately, little significant advancement has been made compared with the demand of engineering geology. The seismic imaging method and its corresponding equipment are viewed as the most hopeful choice for 0-50 m depth and are studied in this research systematically. The recording equipment CSA is made and the related in-situ data processing software is also developed. Field application experiment for shallow seismic prospecting has been finished, the results show that the CSA seismic imaging and its application technology are effective and practical for the engineering geophysical prospecting of 0-50 m depth, and can meet the demand of engineering geology investigation. Hence, the geophysical method and equipment, which can meet the demand for 0-50 m depth engineering geology investigation have been formed through this research. (authors)

  7. Prospective teachers information and communication technology metaphors

    Directory of Open Access Journals (Sweden)

    Ömür Akdemir

    2015-04-01

    Full Text Available Determination of the perceptions of the prospective teachers for the Information and Communications Technology (ICT terms have a remarkable potential to provide input for technology integration plans and ICT trainings. Within this context, the purpose of this study is to discover the metaphors constructed by prospective teachers for the ICT terms. Data were gathered from 180 prospective teachers through survey. 977 valid metaphors constructed by the participants were grouped into conceptual categories for the six ICT terms. The most common conceptual categories are “developing and changing” for technology, “making life easy” for computers and search engines, “limitless and endless” for the Internet, “means of communication” for social networks, and “addictive items” for video games. Future research should concentrate on investigating the match and mismatches between intended use of the ICT tools and the perception of the prospective teachers.

  8. Overview of the uranium prospecting in Uruguay

    International Nuclear Information System (INIS)

    Rossi, P; Vaz Chaves, N.; Pirelli, H.

    1985-01-01

    The report is about Uranium prospection in Uruguay by DINAMIGE experts. They were explained the radioactive properties elements in Uranium and its importance as a fuel oil for electric energy generation

  9. Hospital Outpatient Prospective Payment System (OPPS) Lim...

    Data.gov (United States)

    U.S. Department of Health & Human Services — Hospital Outpatient Prospective Payment System (OPPS) Limited Data Set This file contains select claim level data and is derived from 2010 hospital outpatient PPS...

  10. Present status and physics prospects of SSC

    International Nuclear Information System (INIS)

    Sugimoto, Shojiro

    1990-01-01

    Physics prospects of Superconducting Super Collider (SSC) are discussed, referring to other coming colliders. In addition, the present status of the SSC project and detector proposals for the experiments are described. (author)

  11. Uranium prospection methods illustrated with examples

    International Nuclear Information System (INIS)

    Valsardieu, C.

    1985-01-01

    Uranium exploration methods are briefly reviewed: aerial (radiometric, spectrometric), surface (mapping, radiometric, geophysical, geochemical), sub-surface (well logging, boring) and mining methods in the different steps of a mine project: preliminary studies, general prospecting, detailed prospecting deposit area and deposit estimation. Choice of methods depends strongly on geographic and geologic environment. Three examples are given concerning: an intragranitic deposit Limousin (France), a deposit spatially related to a discordance Athabasca (Canada) and a sedimentary deposit Manyingee (Western Australia) [fr

  12. Essence and prospects of internet banking

    OpenAIRE

    Popova I.; Fesenko Ya.

    2017-01-01

    The paper discussed the current state and prospects of development of internet banking. The aim of the article is to define the “Internet banking” concept of the disclosure of its essence, the study of the current state and prospects of development. The advantages and disadvantages of the system. In the following general research methods were used: analysis, to reveal the concept of “Internet Banking” analyzes the main advantages and disadvantages, comparison, generalization. A number of ...

  13. Training course on radiometric prospecting techniques

    International Nuclear Information System (INIS)

    1979-01-01

    A training course on radiometric prospecting techniques was presented by the Atomic Energy Board in collaboration with the South African Geophysical Association and the Geological Society of South Africa. Various aspects related to uranium prospecting were discussed e.g. the uranium supply and demand position, the basic physics of radioactivity, uranium geochemistry, mineralogy and mobility, the instrumentation and techniques used in uranium exploration, for example, borehole logging, radon emanometry and airborne radiometric surveys and also data processing and interpretation methods

  14. The commercial prospects for tidal stream power

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-07-01

    The prospects for obtaining energy from tidal currents were examined in 1993 when it was concluded that, although the UK resource is large, the unit cost of energy would be relatively high. Interest has continued, however, and in December 2000 the Energy Technology Support Unit (ETSU), on behalf of the Department of Trade and Industry (DTI), commissioned Binnie Black and Veatch (BBV) to re-examine these prospects from a commercial point of view. (author)

  15. Health values and prospect theory: a comment.

    Science.gov (United States)

    Stratmann-Schoene, D; Klose, T

    2001-01-01

    In a recent volume of Medical Decision Making, Treadwell and Lenert stated that under prospect theory, community members compared with patients underestimate the utility of health improvements. In this comment, the authors show that this statement holds only for a subset of possible preference functions. Furthermore, the authors provide arguments that, in general, the rater's current health state is not the appropriate reference level if applying prospect theory to health valuations.

  16. Prospect Theory for Online Financial Trading

    Science.gov (United States)

    Liu, Yang-Yu; Nacher, Jose C.; Ochiai, Tomoshiro; Martino, Mauro; Altshuler, Yaniv

    2014-03-01

    Prospect theory is widely viewed as the best available descriptive model of how people evaluate risk in experimental settings. According to prospect theory, people make decisions based on the potential value of losses and gains rather than the final outcome. People are risk-averse with respect to gains and risk-seeking with respect to losses, a phenomenon called ``loss aversion''. Despite of the fact that prospect theory has been well studied in behavioral economics at the theoretical level, there exist very few empirical research and most of them has been undertaken with micro-panel data. Here we analyze the trading activities of over 1.5 million members of an online financial trading community over 28 months, aiming to explore the large-scale empirical aspect of prospect theory. By analyzing and comparing the behaviour of ``winners'' and ``losers'', i.e., traders with positive or negative final net profit, we find clear evidence of the loss aversion phenomenon, an essence in prospect theory. This work demonstrates an unprecedented large-scale empirical evidence of prospect theory. It has immediate implication in financial trading, e.g., developing new trading strategies by minimizing the effect of loss aversion. It also provides opportunity to augment online social trading, where users are allowed to watch and follow the trading activity of others, by predicting potential winners based on their historical trading behaviour.

  17. DADOS-Prospective: an open source application for Web-based prospective data collection

    Directory of Open Access Journals (Sweden)

    Nguyen Lam

    2006-11-01

    Full Text Available Abstract Background Randomized, prospective trials involving multi-institutional collaboration have become a central part of clinical and translational research. However, data management and coordination of multi-center studies is a complex process that involves developing systems for data collection and quality control, tracking data queries and resolutions, as well as developing communication procedures. We describe DADOS-Prospective, an open-source Web-based application for collecting and managing prospective data on human subjects for clinical and translational trials. DADOS-Prospective not only permits users to create new clinical research forms (CRF and supports electronic signatures, but also offers the advantage of containing, in a single environment, raw research data in downloadable spreadsheet format, source documentation and regulatory files stored in PDF format, and audit trails. Results Feedback from formal and field usability tests was used to guide the design and development of DADOS-Prospective. To date, DADOS-Prospective has been implemented in five prospective clinical studies at our institution. Four of these studies are still in the CRF creation phase and one study has been entirely launched. Conclusion DADOS-Prospective has significant advantages over existing Web-based data collecting programs. At our institution, it has been demonstrated to be an efficient tool for prospective clinical studies.

  18. Age effects in emotional prospective memory: cue valence differentially affects the prospective and retrospective component.

    Science.gov (United States)

    Schnitzspahn, Katharina M; Horn, Sebastian S; Bayen, Ute J; Kliegel, Matthias

    2012-06-01

    While first studies suggested that emotional task material may enhance prospective memory performance in young and older adults, the extent and mechanisms of this effect are under debate. The authors explored possible differential effects of cue valence on the prospective and retrospective component of prospective memory in young and older adults. Forty-five young and 41 older adults performed a prospective memory task in which emotional valence of the prospective memory cue was manipulated (positive, negative, neutral). The multinomial model of event-based prospective memory was used to analyze effects of valence and age on the two prospective memory components separately. Results revealed an interaction indicating that age differences were smaller in both emotional valence conditions. For older adults positive cues improved the prospective component, while negative cues improved the retrospective component. No main effect of valence was found for younger adults on an overt accuracy measure, but model-based analyses showed that the retrospective component was enhanced in the positive compared with the negative cue condition. The study extends the literature in demonstrating that processes underlying emotional effects on prospective memory may differ depending on valence and age. PsycINFO Database Record (c) 2012 APA, all rights reserved

  19. Prospect for extreme field science

    Energy Technology Data Exchange (ETDEWEB)

    Tajima, T. [Ludwig Maximilian Univ. and Max Planck Institute for Quantum Optics, Garching (Germany); Japan Atomic Energy Agency, Kyoto and KEK, Tsukuba (Japan)

    2009-11-15

    The kind of laser extreme light infrastructure (ELI) provides will usher in a class of experiments we have only dreamed of for years. The characteristics that ELI brings in include: the highest intensity ever, large fluence, and relatively high repetition rate. A personal view of the author on the prospect of harnessing this unprecedented opportunity for advancing science of extreme fields is presented. The first characteristic of ELI, its intensity, will allow us to access, as many have stressed already, extreme fields that hover around the Schwinger field or at the very least the neighboring fields in which vacuum begins to behave as a nonlinear medium. In this sense, we are seriously probing the 'material' property of vacuum and thus the property that theory of relativity itself described and will entail. We will probe both special theory and general theory of relativity in regimes that have been never tested so far. We may see a glimpse into the reach of relativity or even its breakdown in some extreme regimes. We will learn Einstein and may even go beyond Einstein, if our journey is led. Laser-driven acceleration both by the laser field itself and by the wakefield that is triggered in a plasma is huge. Energies, if not luminosity, we can access, may be unprecedented going far beyond TeV. The nice thing about ELI is that it has relatively high repetition rate and average fluence as compared with other extreme lasers. This high fluence can be a key element that leads to applications to high energy physics, such as gamma-gamma collider driver experiment, and some gamma ray experiments that may be relevant in the frontier of photo-nuclear physics, and atomic energy applications. Needless to say, high fluence is one of most important features that industrial and medical applications may need. If we are lucky, we may see a door opens at the frontier of novel physics that may not be available by any other means. (authors)

  20. Neurocutaneous syndrome: A prospective study

    Directory of Open Access Journals (Sweden)

    Radheshyam Purkait

    2011-01-01

    Full Text Available Background: Neurocutaneous syndromes (NCS are a group of genetic disorders that produce a variety of developmental abnormalities of the skin along with an increased risk of neurological complications. Cutaneous manifestations usually appear early in life and progress with time, but neurological features generally present at a later age. There is a paucity of data regarding the evolution of skin lesions and their correlation with the central nervous system involvement in children. Aim: The primary objective was to track the course of skin lesions in various forms of NCS in the pediatric age group. Our secondary aim was to assess whether there was any predictive value of the lesions in relation to the neurological manifestations. Materials and Methods: This prospective longitudinal study was conducted at a tertiary care pediatric dermatology referral clinic of the Institute of Child Health, Kolkata, West Bengal. Children between the age group 0 and 12 years were included in the study on the basis of standard diagnostic criteria for different NCS, during the period from March, 2000 to February, 2004, and each of the enrolled cases were followed up for a duration of six years. Results: The study population comprised of 67 children (35 boys, 32 girls.The mean age of presentation was 33.8±27.8 months (range 10 days to 111 months. The various forms of NCS observed was neurofibromatosis 1(NF1 (n=33, tuberous sclerosis complex (TSC (n=23, Sturge Weber syndrome (n=6, ataxia telangiectasia (n=2, PHACE syndrome (n=1, incontinentia pigmenti (n=1, and hypomelanosis of Ito (n=1. The presentations were varied, ranging from predominantly cutaneous to primarily neurological, depending on the disease entity and age group concerned. There was a significant increase in the number of café au lait macules (CALMs with time (P=0.0002 in NF1, unlike that of hypopigmented macules of TSC (P=0.15. Statistically, no relation was documented between the evolution of skin

  1. Prospective Ukrainian lunar orbiter mission

    Science.gov (United States)

    Shkuratov, Y.; Litvinenko, L.; Shulga, V.; Yatskiv, Y.; Kislyuk, V.

    Ukraine has launch vehicles that are able to deliver about 300 kg to the lunar orbit. Future Ukrainian lunar program may propose a polar orbiter. This orbiter should fill principal information gaps in our knowledge about the Moon after Clementine and Lunar Prospector missions and the future missions, like Smart-1, Lunar-A, and Selene. We consider that this can be provided by radar studies of the Moon with supporting optical polarimetric observations from lunar polar orbit. These experiments allow one to better understand global structure of the lunar surface in a wide range of scales, from microns to kilometers. We propose three instruments for the prospective lunar orbiter. They are: a synthetic aperture imaging radar (SAR), ground-penetrating radar (GPR), and imaging polarimeter (IP). The main purpose of SAR is to study with high resolution (50 m) the permanently shadowed sites in the lunar polar regions. These sites are cold traps for volatiles, and have a potential of resource utilization. Possible presence of water ice in the regolith in the sites makes them interesting for permanent manned bases on the Moon. Radar imaging and mapping of other interesting regions could be also planned. Multi-frequencies multi-polarization soun d ing of the lunar surface with GPR can provide information about internal structure of the lunar surface from meters to several hundred meters deep. GPR can be used for measuring the megaregolith layer properties, detection of cryptomaria, and studies of internal structure of the largest craters. IP will be a CCD camera with an additional suite of polarizers. Modest spatial resolution (100 m) should provide a total coverage or a large portion of the lunar surface in oblique viewing basically at large phase angles. Polarization degree at large (>90°) phase angles bears information about characteristic size of the regolith particles. Additional radiophysical experiments are considered with the use of the SAR system, e.g., bistatic radar

  2. A prospective treatment for sepsis

    Directory of Open Access Journals (Sweden)

    Shahidi Bonjar MR

    2015-05-01

    Full Text Available Mohammad Rashid Shahidi Bonjar,1 Leyla Shahidi Bonjar2 1School of Dentistry, 2College of Pharmacy, Kerman University of Medical Sciences, Kerman, Iran Abstract: The present paper proposes a prospective auxiliary treatment for sepsis. There exists no record in the published media on the subject. As an auxiliary therapy, efficacious extracorporeal removal of sepsis-causing bacterial antigens and their toxins (BATs from the blood of septic patients is discussed. The principal component to this approach is a bacterial polyvalent antibody-column (BPVAC, which selectively traps wide spectrum of BATs from blood in an extracorporeal circuit, and detoxified blood returns back to the patient’s body. BPVAC treatment would be a device of targeted medicine. Detoxification is performed under supervision of trained personnel using simple blood-circulating machines in which blood circulates from the patient to BPVAC and back to the patient aseptically. BPVACs’ reactive sites consist of carbon nanotubes on which a vast spectra of polyvalent BATs-antibodies are bond to. The devise acts as a biological filter that selectively immobilizes harmful BATs from intoxicated blood; however, no dialysis is involved. For effective neutralization, BPVAC provides large contact surface area with blood. BPVAC approach would have advantages of: 1 urgent neutralization of notorious BATs from blood of septic patients; 2 applicability in parallel with conventional treatments; 3 potential to minimize side effects of the malady; 4 applicability for a vast range of BATs; 5 potential to eliminate contact of BATs with internal tissues and organs; 6 tolerability by patients sensitive to antiserum injections; 7 capability for universal application; 8 affectivity when antibiotic-resistant bacteria are involved and the physician has no or limited access to appropriate antibiotics; and 10 being a single-use, disposable, and stand-alone device. Before using it for clinical trials in

  3. Original and cumulative prospect theory: a discussion of empirical differences

    NARCIS (Netherlands)

    Wakker, P.P.; Fennema, H.

    1997-01-01

    This note discusses differences between prospect theory and cumulative prospect theory. It shows that cumulative prospect theory is not merely a formal correction of some theoretical problems in prospect theory, but it also gives different predictions. Experiments are described that favor cumulative

  4. Military nuclear activities. Strategic prospects

    International Nuclear Information System (INIS)

    Coldefy, Alain; Wodka-Gallien, Philippe; Tertrais, Bruno; Rouillard, Gwendal; Widemann, Thierry; Guillaume, Louis-Michel; Steininger, Philippe; Guillemette, Alain; Amabile, Jean-Christophe; Granger-Veyron, Nicolas; Carbonnieres, Hubert de; Roche, Nicolas; Guillou, Herve; Bouvier, Antoine; Pastre, Bertrand; Baconnet, Alexis; Monsonis, Guillem; Brisset, Jean-Vincent; Hemez, Remy; Tchernega, Vladimir; Wedin, Lars; Dumoulin, Andre; Razoux, Pierre; Migault, Philippe; Wilson, Ward; Maillard, Benjamin de; Aichi, Leila; Charvoz, Ivan; Rousset, Valery; Lespinois, Jerome de; Kempf, Olivier; Dufourcq, Jean; Gere, Francois; Mauro, Frederic; Delort Laval, Gabriel; Charaix, Patrick; Norlain, Bernard; Collin, Jean-Marie; Jourdier, Francois

    2015-01-01

    This special dossier aims at providing some key articles about France's deterrence doctrine. It provides a comprehensive overview of the challenges and questions about military nuclear activities and opens up some future prospects about this question. The dossier comprises 37 papers dealing with: 1 - Military nuclear activities: yesterday, today, tomorrow (Coldefy, A.); 2 - Deterrence according to French President Francois Hollande: continuation, precision and inflexions (Tertrais, B.); 3 - French deterrence warrantor of our independence in the 21. century (Rouillard, G.); 4 - The deterrence concept prior to the nuclear weapon era (Widemann, T.); 5 - France: the strategic marine force in operation (Guillaume, L.M.); 6 - Relevance of the airborne component in the nuclear deterrence strategy (Steininger, P.); 7 - Deterrence stakes for the Directorate General of Armaments (Guillemette, A.); 8 - The Charles-de-Gaulle aircraft carrier: the deterrence voice from the sea (Wodka-Gallien, P.); 9 - Deterrence: missions of the army's radiation protection department (Amabile, J.C.; Granger-Veyron, N.; Carbonnieres, H. de); 10 - The French Atomic Energy Commission (CEA) and the French defense strategy (Roche, N.); 11 - DCNS, general contractor in the service of deterrence (Guillou, H.); 12 - The airborne nuclear component for MBDA (Bouvier, A.); 13 - Ballistic missile of the marine nuclear component: industrial stakes (Pastre, B.); 14 - Beyond defense against missiles: a US anti-deterrence strategy (Baconnet, A.); 15 - Deterrence dynamics in South Asia (Monsonis, G.); 16 - Military nuclear activities in East Asia (Brisset, J.V.); 17 - North Korea would own nuclear weapons, so what? (Hemez, R.); 18 - About the risk of nuclear warfare in Europe (Tchernega, V.); 19 - Present day nuclear activities: deterrence and gesticulation (Wedin, L.); 20 - Belgian F-16 replacement: nuclear dimension (Dumoulin, A.); 21 - Israel and nuclear deterrence (Razoux, P.); 22 - Nuclear

  5. Uranium prospecting through radon detection; La prospection de l'uranium par le radon

    Energy Technology Data Exchange (ETDEWEB)

    Pradel, J [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1956-07-01

    Prospecting rests on the determination of the concentration of ground air in radon. Radon diffusing from deep uranium bearing layers is detected in upper ground layers. (author) [French] La prospection est basee sur l'etude de la concentration en radon dans l'air du sol. Dans les terrains superficiels, on decele le radon qui diffuse a partir des couches profondes uraniferes. (auteur)

  6. The data of Lelvy and Levy , "Prospect theory: much ado about nothing??", support prospect theory

    NARCIS (Netherlands)

    Wakker, P.P.

    2003-01-01

    Levy and Levy (Management Science, 2002) present data that, according to their claims, violate prospect theory. They suggest that prospect theoryys hypothesis of an S-shaped value function, concave for gains and convex for losses, is incorrect. However, all of the data of Levy and Levy are perfectly

  7. Basic data for uranium prospecting in Argentina

    International Nuclear Information System (INIS)

    Belluco, A.; Rodriguez, E.; Martinez, C.; Marinkeff, K.

    1977-01-01

    After dealing briefly with the geochemical cycle of uranium in the earth's crust, and indicating the principal conditions under which different types of deposits are formed, the paper goes on to determine the uraniferous are of mainland Argentina (approximately 900000 km 2 ). Since evidence for the presence of uranium and other radioactive elements in many parts of the country has long been available, an attempt was made to systemize the existing information and classify the uraniferous sites so as to determine their temporal, spatial and genetic relationships with the different containing rocks. In addition, a study was made of the factors which contribute to the concentration of uranium in rocks which are accessible to prospecting (litho-stratigraphy, geological history, mettallogenic cycles, etc.). On the basis of these studies and considering the regional geology of Argentina, 21 ''regional environments'' were defined with varying degrees of probability of containing uranium; these environments will be submitted to long-term regional prospecting studies. It was necessary, however, to make a further sub-division into more homogeneous units with more clearly graded levels of priority, with the result that there are 65 ''prospecting units''. Each of these units, in order of priority, will be subjected to systematic prospecting. Exploratory work on a suitable scale will be carried out in the ''uraniferous'' districts of the ''prospecting units''. The main features of Argentine geology relating to the likelihood of uranium occurrences are briefly described, and maps of the large geotechtonic areas and the ''regional environments'' are included. (author)

  8. Developing Mathematical Resilience of Prospective Math Teachers

    Science.gov (United States)

    Ariyanto, L.; Herman, T.; Sumarmo, U.; Suryadi, D.

    2017-09-01

    Prospective math teachers need to develop positive adaptive attitudes toward mathematics that will enable them to continue learning despite having to deal with obstacles and difficulties. This research focuses on the resilience improvement of the prospective mathematic teachers after being treated using problem-based learning based on their basic knowledge on mathematic and their overall knowledge on math. This research used only one group for pre-test and post-test. The result of this research shows that there is improvement on prospective teachers’ resilience after they were given treatment using problem-based learning. One of the factors causing the resilience improvement of the prospective mathematic teachers is the instructions on students’ work sheet. In the instructions, stud ents were asked to write difficulties in solving math problems as well as write down the solution they take to overcome them. This research can be used as a reference for other researchers who want to do the same research related on students’ resiliency o n math and or math lecturers to improve the resilience of prospective teachers to be resilient teachers on math in the future.

  9. Prospect theory in the valuation of health.

    Science.gov (United States)

    Moffett, Maurice L; Suarez-Almazor, Maria E

    2005-08-01

    Prospect theory is the prominent nonexpected utility theory in the estimation of health state preference scores for quality-adjusted life year calculation. Until recently, the theory was not considered to be developed to the point of implementation in economic analysis. This review focuses on the research and evidence that tests the implementation of prospect theory into health state valuation. The typical application of expected utility theory assumes that a decision maker has stable preferences under conditions of risk and uncertainty. Under prospect theory, preferences are dependent on whether the decision maker regards the outcome of a choice as a gain or loss, relative to a reference point. The conceptual preference for standard gamble utilities in the valuation of health states has led to the development of elicitation techniques. Empirical evidence using these techniques indicates that when individual preferences are elicited, a prospect theory consistent framework appears to be necessary for adequate representation of individual health utilities. The relevance of prospect theory to policy making and resource allocation remains to be established. Societal preferences may not need the same attitudes towards risks as individual preferences, and may remain largely risk neutral.

  10. The application actualities and prospects of geophysical methods to uranium prospecting

    International Nuclear Information System (INIS)

    Liu Qingcheng

    2010-01-01

    Basic principles of geophysical methods to uranium prospect are briefly introduced, and the effects as well as problems in using those methods are analysed respectively. Combining with the increasing demand of uranium resources for Chinese nuclear power development and the higher requirements of geophysical techniques, the developing directions and the thoughts of geophysical techniques in uranium prospecting were proposed. A new pattern with producing, teaching and researching together is brought forward to develop advancing uranium prospecting key technologies and to break through technological bottlenecks depending on independent innovation. Integrated geophysical methods for prospecting uranium deposits are suggested. The method includes geophysical techniques as follows: gravity, magnetic, seismic, radioactive, remote sensing, and geochemical method in some proving grounds. Based on the experimental research, new uranium deposits prospecting models with efficient integrated geophysical methods can be established. (authors)

  11. Scenarios planning: the evolution of prospective thinking

    Directory of Open Access Journals (Sweden)

    Maurício Fernandes Pereira

    2005-01-01

    Full Text Available The world is changing even more than before. Around the world, the organizational stability is in face of threats unnoticed before, due to technologic innovations, uncontrolled financial markets, up to date customers, and an observant society and government, in order to control the organizations’ social and environmental responsibilities. To face this threats, organizations needs to worry even more, renew its long range planning systems, and use Prospective Scenaries to find out, in a better way, the dynamic forces that will preveil in the next years. This paper seeks to clarify the source of prospective thinking that has created and developed this tool. Prospective Thinking is considered, nowadays, one of most innovatives tools used by the strategic management in organizations.

  12. Prospect theory for online financial trading.

    Science.gov (United States)

    Liu, Yang-Yu; Nacher, Jose C; Ochiai, Tomoshiro; Martino, Mauro; Altshuler, Yaniv

    2014-01-01

    Prospect theory is widely viewed as the best available descriptive model of how people evaluate risk in experimental settings. According to prospect theory, people are typically risk-averse with respect to gains and risk-seeking with respect to losses, known as the "reflection effect". People are much more sensitive to losses than to gains of the same magnitude, a phenomenon called "loss aversion". Despite of the fact that prospect theory has been well developed in behavioral economics at the theoretical level, there exist very few large-scale empirical studies and most of the previous studies have been undertaken with micro-panel data. Here we analyze over 28.5 million trades made by 81.3 thousand traders of an online financial trading community over 28 months, aiming to explore the large-scale empirical aspect of prospect theory. By analyzing and comparing the behavior of winning and losing trades and traders, we find clear evidence of the reflection effect and the loss aversion phenomenon, which are essential in prospect theory. This work hence demonstrates an unprecedented large-scale empirical evidence of prospect theory, which has immediate implication in financial trading, e.g., developing new trading strategies by minimizing the impact of the reflection effect and the loss aversion phenomenon. Moreover, we introduce three novel behavioral metrics to differentiate winning and losing traders based on their historical trading behavior. This offers us potential opportunities to augment online social trading where traders are allowed to watch and follow the trading activities of others, by predicting potential winners based on their historical trading behavior.

  13. Prospect theory for online financial trading.

    Directory of Open Access Journals (Sweden)

    Yang-Yu Liu

    Full Text Available Prospect theory is widely viewed as the best available descriptive model of how people evaluate risk in experimental settings. According to prospect theory, people are typically risk-averse with respect to gains and risk-seeking with respect to losses, known as the "reflection effect". People are much more sensitive to losses than to gains of the same magnitude, a phenomenon called "loss aversion". Despite of the fact that prospect theory has been well developed in behavioral economics at the theoretical level, there exist very few large-scale empirical studies and most of the previous studies have been undertaken with micro-panel data. Here we analyze over 28.5 million trades made by 81.3 thousand traders of an online financial trading community over 28 months, aiming to explore the large-scale empirical aspect of prospect theory. By analyzing and comparing the behavior of winning and losing trades and traders, we find clear evidence of the reflection effect and the loss aversion phenomenon, which are essential in prospect theory. This work hence demonstrates an unprecedented large-scale empirical evidence of prospect theory, which has immediate implication in financial trading, e.g., developing new trading strategies by minimizing the impact of the reflection effect and the loss aversion phenomenon. Moreover, we introduce three novel behavioral metrics to differentiate winning and losing traders based on their historical trading behavior. This offers us potential opportunities to augment online social trading where traders are allowed to watch and follow the trading activities of others, by predicting potential winners based on their historical trading behavior.

  14. Prospects for stability in a nuclear subcontinent

    International Nuclear Information System (INIS)

    Rajagopal, S; Chari, Sridhar K.

    2003-01-01

    This book explore the prospects for stability in a nuclear sub-continent. The nonproliferation regimes and nuclear threat reduction, nonproliferation regimes and south asia - is there a meeting point?; maintaining a threshold of strategic autonomy at least cost: continuity in the evolution of India's nuclear policies; role of nuclear doctrines and the state of the armed forces in South Asia; nuclear weapons, deterrence and stability in the international system: South Asian dynamics; assessing China's Asian role and security policies; Kargil war to current threat of war: prospects for stability; discussion; international terrorism and its impact on South Asian stability; a view from Bangladesh etc. are some of the topics covered

  15. Academic decision making and prospect theory.

    Science.gov (United States)

    Mowrer, Robert R; Davidson, William B

    2011-08-01

    Two studies are reported that investigate the applicability of prospect theory to college students' academic decision making. Exp. 1 failed to provide support for the risk-seeking portion of the fourfold pattern predicted by prospect theory but did find the greater weighting of losses over gains. Using a more sensitive dependent measure, in Exp. 2 the results of the first experiment were replicated in terms of the gain-loss effect and also found some support for the fourfold pattern in the interaction between probabilities and gain versus loss. The greatest risk-seeking was found in the high probability loss condition.

  16. Prospective associations between loneliness and emotional intelligence.

    Science.gov (United States)

    Wols, A; Scholte, R H J; Qualter, P

    2015-02-01

    Loneliness has been linked cross-sectionally to emotional skill deficits (e.g., Zysberg, 2012), but missing from the literature is a longitudinal examination of these relationships. The present study fills that gap by examining the prospective relationships between loneliness and emotional functioning in young adolescents in England. One hundred and ninety-six adolescents aged 11-13 years (90 females) took part in the study and completed the youth version of the Mayer-Salovey-Caruso Emotional Intelligence Test (MSCEIT-YV) and the peer-related subscale of the Loneliness and Aloneness Scale for Children and Adolescents (LACA) at two time points, which were 10 months apart. Prospective associations were obtained for male and female adolescents separately using cross-lagged statistical techniques. Our results showed prospective links between understanding and managing emotions and loneliness for both females and males. Perceiving and using emotions were prospectively linked to loneliness in males only. Possible explanations and directions for future research are discussed. Copyright © 2014 The Foundation for Professionals in Services for Adolescents. Published by Elsevier Ltd. All rights reserved.

  17. Prospects of solar desalination in Pakistan

    Energy Technology Data Exchange (ETDEWEB)

    Saif-ur-Rehman, M; Bhatti, M R; Malik, M A

    1973-01-01

    This paper deals with the present state-of-the-art of solar desalination and evaluates the possibility of using solar stills in Pakistan. Along with the world survey of solar desalination units a brief description of the process and solar still is described. The areas of prospective users, i.e., having acute shortage of freshwater, even for drinking, are outlined.

  18. Book Review Microfinance: Perils and Prospects

    African Journals Online (AJOL)

    African Review of Economics and Finance, Vol 4, No. 2, June ... This book explores the perils and prospects of microfinance by looking at the issue ... qualitative data, and a list of references that could be useful to readers who want to learn ...

  19. Prospect Theory in the Heterogeneous Agent Model

    Czech Academy of Sciences Publication Activity Database

    Polach, J.; Kukačka, Jiří

    (2018) ISSN 1860-711X R&D Projects: GA ČR(CZ) GBP402/12/G097 Institutional support: RVO:67985556 Keywords : Heterogeneous Agent Model * Prospect Theory * Behavioral finance * Stylized facts Subject RIV: AH - Economic s OBOR OECD: Finance Impact factor: 0.931, year: 2016 http://library.utia.cas.cz/separaty/2018/E/kukacka-0488438.pdf

  20. Prospects and Constraints of Household Irrigation Practices ...

    African Journals Online (AJOL)

    Constraints and prospects of hand dug wells related to household irrigation were assessed in Hayelom watershed (~1045 ha), by evaluating groundwater suitability for irrigation, soil quality and impact of intervention. 181 hand dug wells have come into existence in the watershed due to intervention and benefiting about ...

  1. Prospective associations between loneliness and emotional intelligence

    NARCIS (Netherlands)

    Wols, A.C.; Scholte, R.H.J.; Qualter, P.

    2015-01-01

    Loneliness has been linked cross-sectionally to emotional skill deficits (e.g., Zysberg, 2012), but missing from the literature is a longitudinal examination of these relationships. The present study fills that gap by examining the prospective relationships between loneliness and emotional

  2. Mathematics Courses for the Prospective Teacher.

    Science.gov (United States)

    Kistler, Barbara C.

    This paper suggests that faculty at two-year institutions need to become partners with colleges of education and K-12 teachers of mathematics in preparing future mathematics teachers. The paper presents the following: a summary of recommendations on programs for prospective teachers; a summary of recommendations about mathematics courses for…

  3. Prospect of small modular reactor development

    International Nuclear Information System (INIS)

    Li Huailin; Zhu Qingyuan; Wang Suli; Xia Haihong

    2014-01-01

    Small modular reactor has the advantages of modular construction, enhanced safety/robustness from simplified designs, better ecomonic, clean and carbon free, compatible with the needs of smaller utilities and diversified application. In this paper, the prospect of small modular reactor is discussed from technology development status, constraints, economic. (authors)

  4. A prospective study of gentamicin ototoxicity

    DEFF Research Database (Denmark)

    Winkel, O; Hansen, M M; Kaaber-Bühler, Søren

    2010-01-01

    of gentamicin did not rule out the possiblity of ototoxicity. These results urge the continuing of prospective studies and indicate that gentamicin should be used only as a link in the primary treatment of severe infection or in cases in which other, less toxic agents have failed....

  5. A prospective study of gentamicin ototoxicity

    DEFF Research Database (Denmark)

    Winkel, O; Hansen, M M; Kaaber-Bühler, Søren

    1978-01-01

    of gentamicin did not rule out the possiblity of ototoxicity. These results urge the continuing of prospective studies and indicate that gentamicin should be used only as a link in the primary treatment of severe infection or in cases in which other, less toxic agents have failed....

  6. Are Prospective English Teachers Linguistically Intelligent?

    Science.gov (United States)

    Tezel, Kadir Vefa

    2017-01-01

    Language is normally associated with linguistic capabilities of individuals. In the theory of multiple intelligences, language is considered to be related primarily to linguistic intelligence. Using the theory of Multiple Intelligences as its starting point, this descriptive survey study investigated to what extent prospective English teachers'…

  7. School Food Practices of Prospective Teachers

    Science.gov (United States)

    Rossiter, Melissa; Glanville, Theresa; Taylor, Jennifer; Blum, Ilya

    2007-01-01

    Background: Schoolteachers can affect students' eating habits in several ways: through nutrition knowledge, positive role modeling, and avoidance of unhealthy classroom food practices. In this study, the knowledge, attitudes, and eating behaviors of prospective teachers as determinants of intended classroom food practices and the school…

  8. Ecological value orientations of prospective secondary school ...

    African Journals Online (AJOL)

    A

    ecological balance is believed to depend largely on values acquired in the course of his/her life. Putnam .... North American culture and the more ecological vision of the Latin American .... ecological/environmental value orientations of different segments of .... of prospective teachers in Ethiopia as compared to participants of.

  9. Silicon drift detectors, present and future prospects

    Science.gov (United States)

    Takahashi, J.; Bellwied, R.; Beuttenmuller, R.; Caines, H.; Chen, W.; Dyke, H.; Hoffmann, G. W.; Humanic, T.; Kotov, I.; Kuczewski, P.; Leonhardt, W.; Li, Z.; Lynn, D.; Minor, R.; Munhoz, M.; Ott, G.; Pandey, S. U.; Schambach, J.; Soja, R.; Sugarbaker, E.; Willson, R. M.

    2001-04-01

    Silicon drift detectors provide unambiguous two-dimensional position information for charged particle detection with a single detector layer. A large area silicon drift detector was developed for the inner tracking detector of the STAR experiment at RHIC. In this paper, we discuss the lessons learned and the future prospects of this technology.

  10. Rural renewable energy (prospects) in Estonia

    Energy Technology Data Exchange (ETDEWEB)

    Tomson, T. [Estonian Energy Research Institute, Tallinn (Estonia); Kaeaermann, L. [Estonian National Maritime Board, Tallinn (Estonia); Raesaar, P. [Tallinn Technological University, Tallinn (Estonia)

    1997-12-31

    Total potential share of renewables (biomass, wind, hydropower and solar) in Estonia is 35 %. Total real share (wood, wood chips) of renewables is only about 4.5 % (1995). The constrains and prospects of the development are discussed. The attention is focused on rural conditions

  11. International conference on Asian nuclear prospects 2010

    International Nuclear Information System (INIS)

    2010-10-01

    The proceedings of the second international conference on Asian nuclear prospects was held during October 10-13, 2010. The topics covered were atomic minerals exploration, fuels and fuel fabrication, fast reactor engineering and technology, thermal reactors, fuel reprocessing, materials development, nuclear instrumentation and electronics, reactor and environmental safety, waste management, knowledge management and HRD. Papers relevant to INIS are indexed separately

  12. Labelling of Students by Prospective Teachers.

    Science.gov (United States)

    Frerichs, Allen H.; Adelman, Stan I.

    The basic purpose of this study was to determine the effects of telling prospective teachers that a classroom of adolescents, viewed on video tape, were low-achieving students. An experimental group was informed that the adolescents were slow learners having considerable difficulty in school. A control group, observing the same video tape was told…

  13. Future Prospects for Geographical Education in Slovenia

    Science.gov (United States)

    Resnic Planinc, Tatjana

    2011-01-01

    This paper deals with future prospects for geographical education in Slovenia, with special emphasis on the development and aims of the didactics of geography. The author discusses the past development of geographical curricula and of competencies of geography teachers, and the education of future teachers of the subject in Slovenia. Her ideas are…

  14. Do Marital Prospects Dissuade Unmarried Fertility?

    DEFF Research Database (Denmark)

    Kennes, John; Knowles, John

    is that weaker marriage-market prospects may be strong enough to explain higher unmarried birth rates. Relative to the existing literature, the essential contributions of the model are to allow for accumulation of children over the lifecycle and for the marriage of single mothers. We use the model...

  15. Pattern recognition applied to uranium prospecting

    Energy Technology Data Exchange (ETDEWEB)

    Briggs, P L; Press, F [Massachusetts Inst. of Tech., Cambridge (USA). Dept. of Earth and Planetary Sciences

    1977-07-14

    It is stated that pattern recognition techniques provide one way of combining quantitative and descriptive geological data for mineral prospecting. A quantified decision process using computer-selected patterns of geological data has the potential for selecting areas with undiscovered deposits of uranium or other minerals. When a natural resource is mined more rapidly than it is discovered, its continued production becomes increasingly difficult, and it has been noted that, although a considerable uranium reserve may remain in the U.S.A., the discovery rate for uranium is decreasing exponentially with cumulative exploration footage drilled. Pattern recognition methods of organising geological information for prospecting may provide new predictive power, as well as insight into the occurrence of uranium ore deposits. Often the task of prospecting consists of three stages of information processing: (1) collection of data on known ore deposits; (2) noting any regularities common to the known examples of an ore; (3) selection of new exploration targets based on the results of the second stage. A logical pattern recognition algorithm is here described that implements this geological procedure to demonstrate the possibility of building a quantified uranium prospecting guide from diverse geologic data.

  16. Hydrokinetic Energy Conversion Systems: Prospects and ...

    African Journals Online (AJOL)

    Being also a variant of the small hydropower scheme, which are usually site specific, much of the studies done on the technology are suited to specific sites and the peculiar hydrology of those localities. This paper, thus, explores this new emerging technology and its prospects, potentials, challenges and frameworks for its ...

  17. Neutrino experiments: Status, recent progress, and prospects

    International Nuclear Information System (INIS)

    Brice, S

    2008-01-01

    Neutrino physics has seen an explosion of activity and new results in the last decade. In this report the current state of the field is summarized, with a particular focus on progress in the last two years. Prospects for the near term (roughly 5 years) are also described

  18. Decision analysis with cumulative prospect theory.

    Science.gov (United States)

    Bayoumi, A M; Redelmeier, D A

    2000-01-01

    Individuals sometimes express preferences that do not follow expected utility theory. Cumulative prospect theory adjusts for some phenomena by using decision weights rather than probabilities when analyzing a decision tree. The authors examined how probability transformations from cumulative prospect theory might alter a decision analysis of a prophylactic therapy in AIDS, eliciting utilities from patients with HIV infection (n = 75) and calculating expected outcomes using an established Markov model. They next focused on transformations of three sets of probabilities: 1) the probabilities used in calculating standard-gamble utility scores; 2) the probabilities of being in discrete Markov states; 3) the probabilities of transitioning between Markov states. The same prophylaxis strategy yielded the highest quality-adjusted survival under all transformations. For the average patient, prophylaxis appeared relatively less advantageous when standard-gamble utilities were transformed. Prophylaxis appeared relatively more advantageous when state probabilities were transformed and relatively less advantageous when transition probabilities were transformed. Transforming standard-gamble and transition probabilities simultaneously decreased the gain from prophylaxis by almost half. Sensitivity analysis indicated that even near-linear probability weighting transformations could substantially alter quality-adjusted survival estimates. The magnitude of benefit estimated in a decision-analytic model can change significantly after using cumulative prospect theory. Incorporating cumulative prospect theory into decision analysis can provide a form of sensitivity analysis and may help describe when people deviate from expected utility theory.

  19. Prospects on electroweak physics from the LHC

    International Nuclear Information System (INIS)

    Vikas, Pratibha

    2001-01-01

    The abundant production of gauge bosons, gauge boson pairs and top quarks at the LHC will offer the opportunity for comprehensive and challenging tests of theoretical predictions in the electroweak sector. Some issues which influence these measurements followed by prospects on some possible measurements by the ATLAS and CMS experiments at the Large Hadron Collider (LHC), at CERN are discussed. (author)

  20. Challenges and Prospects of Traditional Food Processing ...

    African Journals Online (AJOL)

    This paper focuses on challenges and prospects of traditional food processing technologies and their products in Nigeria. The major objective of the paper is to identify the challenges confronting traditional food processing technologies as well as the potentials the traditional food processing technologies has in boosting the ...

  1. Prospective Teachers' Understandings: Function and Composite Function.

    Science.gov (United States)

    Meel, David E.

    2003-01-01

    The current education reform efforts place greater emphasis on conceptual understanding and focus attention on teacher preparation, especially on the adequacy of teachers' mathematical knowledge of the material they will be teaching. This paper discusses the responses of 20 prospective elementary and special education mathematics specialists to…

  2. A prospective toxicology analysis in alcoholics

    DEFF Research Database (Denmark)

    Thomsen, Jørgen Lange; Simonsen, Kirsten Wiese; Felby, Søren

    1997-01-01

    A prospective and comprehensive investigation was done on 73 medico–legal autopsies in alcoholics. The results of the toxicology analyses are described. Alcohol intoxication was the cause of death in 8%, combined alcohol/drug intoxication in 15% and drugs alone in 19%. Alcoholic ketoacidosis...

  3. Prospective Teachers' Opinions Concerning Children's Rights

    Science.gov (United States)

    Faiz, Melike; Kamer, Selman Tunay

    2017-01-01

    Consideration of the child as a social being and his/her not having the power of self-protection have propounded the significance of children's rights. Teachers are important to educate the individual. Prospective teachers who will be teachers of the future will have a considerable amount of presidency. Thus, the main objective of this research is…

  4. Rural renewable energy (prospects) in Estonia

    Energy Technology Data Exchange (ETDEWEB)

    Tomson, T [Estonian Energy Research Institute, Tallinn (Estonia); Kaeaermann, L [Estonian National Maritime Board, Tallinn (Estonia); Raesaar, P [Tallinn Technological University, Tallinn (Estonia)

    1998-12-31

    Total potential share of renewables (biomass, wind, hydropower and solar) in Estonia is 35 %. Total real share (wood, wood chips) of renewables is only about 4.5 % (1995). The constrains and prospects of the development are discussed. The attention is focused on rural conditions

  5. Technology development and application research of remote sensing in uranium geological prospecting

    International Nuclear Information System (INIS)

    Liu Dechang; Dong Xiuzhen; Wang Zitao

    2012-01-01

    From the application, the concept, the theory study and application effect, this article discusses technology development and application research of remote sensing in uranium geological prospecting. The prospecting way from 'information prospecting' to 'theoretical prospecting' to 'simulated prospecting' to 'technology prospecting' with remote sensing is provided and achieved significant prospecting effect. (authors)

  6. Geochemical prospect ion results of Mariscala aerial photo

    International Nuclear Information System (INIS)

    Filippini, J.

    1989-01-01

    This report shows the geochemical prospect ion results carried out within the framework of the metalical mining prospect ion in Mariscala aerial photo. Lavalleja district belong to the Mining inventory programme of Uruguay.

  7. Electronic Banking in Nigeria: Concepts, Challenges and Prospects ...

    African Journals Online (AJOL)

    Electronic Banking in Nigeria: Concepts, Challenges and Prospects. ... examined its prospects for Nigerian banks and discussed associated risks. ... E banking, it also observed, holds enormous potentials for the banking industry in Nigeria.

  8. Some problems on remote sensing geology for uranium prospecting

    International Nuclear Information System (INIS)

    Yang Tinghuai.

    1988-01-01

    Remote sensing is a kind of very effective method which can be used in all stages of geological prospecting. Geological prospecting with remote sensing method must be based on different genetic models of ore deposits, characteristics of geology-landscape and comprehensive analysis for geophysical and geochemical data, that is, by way of conceptual model prospecting. The prospecting results based on remote sensing geology should be assessed from three aspects such as direct, indirect and potential ones

  9. Prospective Memory in a Language-Trained Chimpanzee ("Pan Troglodytes")

    Science.gov (United States)

    Beran, Michael J.; Perdue, Bonnie M.; Bramlett, Jessica L.; Menzel, Charles R.; Evans, Theodore A.

    2012-01-01

    Prospective memory involves the encoding, retention, and implementation of an intended future action. Although humans show many forms of prospective memory, less is known about the future oriented processes of nonhuman animals, or their ability to use prospective memory. In this experiment, a chimpanzee named Panzee, who had learned to associate…

  10. Turkish Prospective Teachers' Understanding and Misunderstanding on Global Warming

    Science.gov (United States)

    Ocal, A.; Kisoglu, M.; Alas, A.; Gurbuz, H.

    2011-01-01

    The key objective of this study is to determine the Turkish elementary prospective teachers' opinions on global warming. It is also aimed to establish prospective teachers' views about the environmental education in Turkish universities. A true-false type scale was administered to 564 prospective teachers from science education, social studies…

  11. Effects of Learned Episodic Event Structure on Prospective Duration Judgments

    Science.gov (United States)

    Faber, Myrthe; Gennari, Silvia P.

    2017-01-01

    The field of psychology of time has typically distinguished between prospective timing and retrospective duration estimation: in prospective timing, participants attend to and encode time, whereas in retrospective estimation, estimates are based on the memory of what happened. Prior research on prospective timing has primarily focused on…

  12. 50 CFR 27.64 - Prospecting and mining.

    Science.gov (United States)

    2010-10-01

    ... 50 Wildlife and Fisheries 6 2010-10-01 2010-10-01 false Prospecting and mining. 27.64 Section 27.64 Wildlife and Fisheries UNITED STATES FISH AND WILDLIFE SERVICE, DEPARTMENT OF THE INTERIOR... Property § 27.64 Prospecting and mining. Prospecting, locating, or filing mining claims on national...

  13. Turkish Prospective Chemistry Teachers' Alternative Conceptions about Acids and Bases

    Science.gov (United States)

    Boz, Yezdan

    2009-01-01

    The purpose of this study was to obtain prospective chemistry teachers' conceptions about acids and bases concepts. Thirty-eight prospective chemistry teachers were the participants. Data were collected by means of an open-ended questionnaire and semi-structured interviews. Analysis of data indicated that most prospective teachers did not have…

  14. Prospect theory, reference points, and health decisions

    Directory of Open Access Journals (Sweden)

    Alan Schwartz

    2008-02-01

    Full Text Available In preventative health decisions, such as the decision to undergo an invasive screening test or treatment, people may be deterred from selecting the test because its perceived disutility relative to not testing is greater than the utility associated with prevention of possible disease. The prospect theory editing operation, by which a decision maker's reference point is determined, can have important effects on the disutility of the test. On the basis of the prospect theory value function, this paper develops two approaches to reducing disutility by directing the decision maker's attention to either (actual past or (expected future losses that result in shifted reference points. After providing a graphical description of the approaches and a mathematical proof of the direction of their effect on judgment, we briefly illustrate the potential value of these approaches with examples from qualitative research on prostate cancer treatment decisions.

  15. 2009 PNST prospective - Book of abstracts

    International Nuclear Information System (INIS)

    Aulanier, Guillaume; Jacquey, Christian; Bocchialini, Karine; Savoini, Philippe; Mazelle, Christian; Galtier, Sebastien; Passot, Thierry; Appourchaux, Thierry; Pincon, Jean-Louis; Lathuillere, Chantal; Dudok de Wit, Thierry; Lignieres, Francois; Malherbe, Jean-Marie; Jacquey, Christian; Fontaine, Dominique; Vilmer, Nicole

    2009-09-01

    PNST (Programme National Soleil-Terre/Sun-Earth National Program) is dedicated to analysis of the Sun-Earth system, from generation of the solar magnetic field, flares and coronal mass ejections, until impact on the terrestrial magnetosphere, ionosphere and thermosphere. Research activities carried out in the frame of Programme National Soleil-Terre (PNST) rely on both ground-based and space-borne instruments. One of the main objectives of PNST is to stimulate coordinated studies and to optimize scientific return of these instruments. The 2009 PNST prospective colloquium comprised 9 sessions: 1 - Eruptive activity in plasmas; 2 - Particles heating and acceleration; 3 - Energy transfers at different scales and turbulence; 4 - Coupling between the different envelopes; 5 - Sun-Earth relations and space meteorology; 6 - Sun and star prototypes; 7 - Databases, services; 8 - Instrumentation; 9 - Prospective. This document is the book of abstracts of the colloquium

  16. Synchrotron radiation and prospects of its applications

    Energy Technology Data Exchange (ETDEWEB)

    Kulipanov, G; Skrinskii, A

    1981-04-01

    Current and prospective applications are described of synchrotron radiation resulting from the motion of high-energy electrons or positrons in a magnetic field and covering a wide spectral range from the infrared to X-ray. The advantages of the synchrotron radiation include a big source luminance, a small angular divergence, the possibility of calculating the absolute intensity and the spectral distribution of the radiation. Special storage rings are most suitable as a source. Synchrotron radiation is applied in X-ray microscopy, energy diffractometry, atomic and molecular spectroscopy, in the structural analysis of microcrystals, very rapid diffractometry of biological objects and crystals, and in Moessbauer spectroscopy. The prospective applications include uses in metrology, medicine, X-ray lithography, elemental analysis, molecular microsurgery, and in radiation technology.

  17. Cogeneration in Australia. Situation and prospects

    International Nuclear Information System (INIS)

    1997-01-01

    This Research Paper is mainly concerned with the status and prospects for cogeneration in Australia. An introductory chapter reviews the fundamentals of cogeneration, covering both technical and institutional aspects. A range of technologies are employed in cogeneration: these technologies and their efficiency and environmental impact effects are discussed in Chapter 2. The economics of cogeneration are a major factor in the profitability of current and potential plants. Potential factors affecting cogeneration economics are discussed .The status of cogeneration in Australia is reviewed for each State and Territory, and includes a number of case studies of existing plants. Government (federal, state, territory) policies that have a significant impact on the attractiveness of cogeneration are reviewed. Finally, the future prospects for cogeneration in Australia, drawing on the preceding chapters and a review of estimated potentials for cogeneration in Australia are presented

  18. Geochemical prospecting for uranium and thorium deposits

    International Nuclear Information System (INIS)

    Boyle, R.W.

    1980-01-01

    A brief review of analytical geochemical prospecting methods for uranium and thorium is given excluding radiometric techniques, except those utilized in the determination of radon. The indicator (pathfinder) elements useful in geochemical surveys are listed for each of the types of known uranium and thorium deposits; this is followed by sections on analytical geochemical surveys based on rocks (lithochemical surveys), unconsolidated materials (pedochemical surveys), natural waters and sediments (hydrochemical surveys), biological materials (biogeochemical surveys) and gases (atmochemical surveys). All of the analytical geochemical methods are applicable in prospecting for thorium and uranium, particularly where radiometric methods fail due to attenuation by overburden, water, deep leaching and so on. Efficiency in the discovery of uranium and/or thorium orebodies is promoted by an integrated methods approach employing geological pattern recognition in the localization of deposits, analytical geochemical surveys, and radiometric surveys. (author)

  19. Geochemical prospecting for thorium and uranium deposits

    International Nuclear Information System (INIS)

    Boyle, R.W.

    1982-01-01

    The basic purpose of this book is to present an analysis of the various geochemical methods applicable in the search for all types of thorium and uranium deposits. The general chemistry and geochemistry of thorium and uranium are briefly described in the opening chapter, and this is followed by a chapter on the deposits of the two elements with emphasis on their indicator (pathfinder) elements and on the primary and secondary dispersion characteristics of thorium and uranium in the vicinity of their deposits. The next seven chapters form the main part of the book and describe geochemical prospecting for thorium and uranium, stressing selection of areas in which to prospect, radiometric surveys, analytical geochemical surveys based on rocks (lithochemical surveys), unconsolidated materials (pedochemical surveys), natural waters and sediments (hydrochemical surveys), biological materials (biogeochemical surveys), gases (atmochemical surveys), and miscellaneous methods. A final brief chapter reviews radiometric and analytical methods for the detection and estimation of thorium and uranium. (Auth.)

  20. Problems and prospects of neutron imaging

    International Nuclear Information System (INIS)

    Kobayashi, Hisao

    2008-01-01

    Technical problems and future prospects of neutron imaging and neutron radiography are reviewed and discussed for further development. For technical problems, neutron sources together with cold neutron, ultra-cold neutron, epithermal and fast-neutron beams, energy converters, and the intensity of neutron beam, dynamic range associated with imaging procedure, etc, are reviewed. As standardization, such indicators as beam purity, sensitivity, image quality, and beam quality are discussed and limitation of neutron radiography is also presented. As neutron imaging has developed as a nondestructive testing technique in industrial applications, further problems and prospects of quality control and qualification to perform neutron radiography, standardization and international cooperation of neutron imaging are discussed. (S. Ohno)

  1. What Prospects for the World Trading System?

    Directory of Open Access Journals (Sweden)

    Agnes Ghibuțiu

    2014-07-01

    Full Text Available New developments and dramatic changes are under way in the world trading system. This paper aims to take stock of the latest and most relevant developments and highlight the prospects for global trade governance. The focus is on three major issues, i.e. : (1 the outcome of the Ninth WTO Ministerial Conference in December 2013 in Bali (Indonesia and especially its significance for enhancing the multilateral trading system; (2 the accelerated pace and scale of negotiations on regional trade agreements (RTAs and their wider impact; and (3 the positive results of continued unilateral trade liberalization efforts, in contrast with the pervasiveness of crisis-related protectionist measures. The paper concludes that, despite improved prospects for multilateral trade liberalization following the last WTO Ministerial Conference, the world trading system is becoming more fragmented and less coherent, and also more uncertain, being increasingly driven by RTAs and a variable geometry approach to WTO trade agreements.

  2. Renewable Energy: Markets and Prospects by Technology

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2011-07-01

    This information paper accompanies the IEA publication Deploying Renewables 2011: Best and Future Policy Practice (IEA, 2011a). It provides more detailed data and analysis, and explores the markets, policies and prospects for a number of renewable energy technologies. This paper provides a discussion of ten technology areas: bioenergy for electricity and heat, biofuels, geothermal energy, hydro energy, ocean energy, solar energy (solar photovoltaics, concentrating solar power, and solar heating), and wind energy (onshore and offshore). Each technology discussion includes: the current technical and market status; the current costs of energy production and cost trends; the policy environment; the potential and projections for the future; and an analysis of the prospects and key hurdles to future expansion.

  3. Complications of ERCP: a prospective study

    DEFF Research Database (Denmark)

    Christensen, Merete; Matzen, Peter; Schulze, Svend

    2004-01-01

    included in this prospective study. Complications were assessed at the time of ERCP and by postal/telephone contact at 30-days after the procedure. RESULTS: A total of 1177 ERCPs were included in the analysis, of which 56.2% were therapeutic. The 30-day complication rate was 15.9%; the procedure...... occurred in relation to 5% of the ERCP procedures (3 deaths). Cardiorespiratory complications occurred in 2.3% (2 deaths). Dilated bile duct ( p = 0.0001), placement of stent ( p = 0.001), and use of more than 40 mg of hyoscine-N-butyl bromide ( p ... analysis. Risk of pancreatitis was increased with age under 40 years ( p = 0.0078), placement of stent ( p = 0.031), and a dilated bile duct ( p = 0.036). CONCLUSIONS: This prospective study confirms that the complication rate of ERCP including therapeutic procedures is high. Cardiopulmonary complications...

  4. Experience and Prospects of Nuclear Heat Application

    International Nuclear Information System (INIS)

    Woite, G.; Konishi, T.; Kupitz, J.

    1998-01-01

    Relevant technical characteristics of nuclear reactors and heat application facilities for district heating, process heat and seawater desalination are presented and discussed. The necessity of matching the characteristics of reactors and heat applications has consequences for their technical and economic viability. The world-wide operating experience with nuclear district heating, process heating, process heat and seawater desalination is summarised and the prospects for these nuclear heat applications are discussed. (author)

  5. The prospective uses of solar energy

    International Nuclear Information System (INIS)

    Masi, M.; Carra, S.

    2007-01-01

    Some aspects inherent the prospective uses of solar energy as renewable energy source are here addressed with particular reference to the technical and economical aspects affecting its use of today and tomorrow. It emerges that neither technical nor availability limitation exist for the extensive use of that primary energy source, but only limitations of economical nature that are indeed under resolution with the installation volumes increase [it

  6. Status and prospects from the LHC

    International Nuclear Information System (INIS)

    Hawkings, Richard

    2010-01-01

    This article reviews the status of the CERN Large Hadron Collider and associated experiments as of July 2010. After a brief discussion of the progress in accelerator and experiment commissioning, the LHC physics landscape is presented, together with a selection of the experimental results achieved so far. Finally the prospects for the 2010-11 LHC physics run are reviewed, with an emphasis on possible discoveries in the Higgs and supersymmetry sectors.

  7. Status and prospects of nuclear desalination

    International Nuclear Information System (INIS)

    Kupitz, J.; Konishi, T.

    2000-01-01

    While availability of potable water is an important prerequisite for socio-economic development, about 1/3 of the world's population is suffering from inadequate potable water supplies. Seawater desalination with nuclear energy could help to cope with the fresh water shortages and several countries are investigating nuclear desalination. Status and future prospects of nuclear desalination and the role of the IAEA in this area are discussed in this paper. (author)

  8. Prospects for Inflationary B-Mode Detection

    Science.gov (United States)

    Kogut, Alan J.

    2011-01-01

    Measurements of the linear polarization of the cosmic microwave background provide a direct window into the physics of inflation. The experimental challenges are daunting: not only is the predicted signal faint compared to the photon noise limit, but it is hidden behind competing foregrounds from both local and cosmic sources. I will discuss the experimental response to these challenges and the prospects for eventual detection and characterization of the inflationary signal.

  9. Regularity effect in prospective memory during aging

    OpenAIRE

    Blondelle, Geoffrey; Hainselin, Mathieu; Gounden, Yannick; Heurley, Laurent; Voisin, Hélène; Megalakaki, Olga; Bressous, Estelle; Quaglino, Véronique

    2016-01-01

    Background: Regularity effect can affect performance in prospective memory (PM), but little is known on the cognitive processes linked to this effect. Moreover, its impacts with regard to aging remain unknown. To our knowledge, this study is the first to examine regularity effect in PM in a lifespan perspective, with a sample of young, intermediate, and older adults.Objective and design: Our study examined the regularity effect in PM in three groups of participants: 28 young adults (18–30), 1...

  10. Geothermal Energy and its Prospects in Lithuania

    International Nuclear Information System (INIS)

    Radeckas, B.

    1995-01-01

    Data on the geothermal resources in lithuania and on their prospective usage are presented. The analysis covers water horizons of the geothermal anomaly in West Lithuania and their hydrogeology. The energy of the 3 km thick geothermal source was evaluated. Technical and economical possibilities of using geothermal energy in West Lithuania are described. Some aspects of the investment and of the project of a geothermal power plant in Klaipeda are considered. (author). 6 refs., 6 tabs., 2 figs

  11. Management situation and prospect of radioactive waste

    International Nuclear Information System (INIS)

    Han, Pil Jun

    1985-04-01

    This book tell US that management situation and prospect of radioactive waste matter, which includes importance of energy, independence, limitation of fossil fuel energy, density of nuclear energy, strategy of supply of energy resource in Korea, nuclear energy development and radioactive waste matter, summary of management of radioactive waste, statistics of radioactive waste, disposal principle of radioactive waste, management on radioactive waste after using, disposal of Trench, La Marche in French, and Asse salt mine in Germany.

  12. AN ECONOMIC FORECAST AND POLICY PROSPECTS

    OpenAIRE

    Brinner, Roger E.

    1992-01-01

    The economy is stagnating today because everyone is waiting for someone else to restart the recovery. Consumers are deferring major purchases until job prospects are rosier. Businesses are pushing down their inventories and payrolls until their order books surge. In essence the economic fundamentals are sound, but at this point, we need a new catalyst for recovery. It is time to implement policies that directly stimulate investment including a self-financing equipment tax credit for productiv...

  13. Development and Prospect of Nanoarchitectured Solar Cells

    OpenAIRE

    Zhang, Bo; Xie, Wenxu; Xiang, Yong

    2015-01-01

    This paper gives an overview of the development and prospect of nanotechnologies utilized in the solar cell applications. Even though it is not clearly pointed out, nanostructures indeed have been used in the fabrication of conventional solar cells for a long time. However, in those circumstances, only very limited benefits of nanostructures have been used to improve cell performance. During the last decade, the development of the photovoltaic device theory and nanofabrication technology enab...

  14. Prospects for early SUSY searches at Lhc

    International Nuclear Information System (INIS)

    Borjanovic, I.

    2009-01-01

    Search for the physics beyond the Standard Model is one of the most relevant goals of the CMS and Atlas experiments at the Large Hadron Collider at CERN. Prospects for early R-parity conserving supersymmetry discovery and mass measurements with the CMS and Atlas detector for the first fb -1 of data are presented. All the presented studies are based on realistic Monte Carlo simulations.

  15. Prospective analysis. Nuclear deterrence in 2030

    International Nuclear Information System (INIS)

    Tertrais, B.

    2006-12-01

    This study is a prospective analysis of the long-term future of nuclear weapons, and particularly the future of French nuclear deterrence after 2015. The selected time period is 2025-2030. The principal objective is to reflect on what the nuclear world might look like during the first part of the 21 st century, beyond the modernization decisions already planned or envisaged, and to draw conclusions for the future of the French deterrent. (author)

  16. Asteroids. Prospective energy and material resources

    Energy Technology Data Exchange (ETDEWEB)

    Badescu, Viorel (ed.) [Bucharest Polytechnic Univ. (Romania). Candida Oancea Institute

    2013-11-01

    Recent research on Prospective Energy and Material Resources on Asteroids. Carefully edited book dedicated to Asteroids prospective energy and material resources. Written by leading experts in the field. The Earth has limited material and energy resources while these resources in space are virtually unlimited. Further development of humanity will require going beyond our planet and exploring of extraterrestrial resources and sources of unlimited power. Thus far, all missions to asteroids have been motivated by scientific exploration. However, given recent advancements in various space technologies, mining asteroids for resources is becoming ever more feasible. A significant portion of asteroids value is derived from their location; the required resources do not need to be lifted at a great expense from the surface of the Earth. Resources derived from Asteroid not only can be brought back to Earth but could also be used to sustain human exploration of space and permanent settlements in space. This book investigates asteroids' prospective energy and material resources. It is a collection of topics related to asteroid exploration, and utilization. It presents past and future technologies and solutions to old problems that could become reality in our life time. The book therefore is a great source of condensed information for specialists involved in current and impending asteroid-related activities and a good starting point for space researchers, inventors, technologists and potential investors. Written for researchers, engineers, and businessmen interested in asteroids' exploration and exploitation.

  17. Examining Media Literacy Levels of Prospective Teachers

    Directory of Open Access Journals (Sweden)

    Taskın INAN

    2012-04-01

    Full Text Available As in many other countries, following the 2007-2008 education year when media literacy courses began to be included in the curricula, media literacy has become one of the discussion topics among educators and decision makers in Turkey. Discussion topics related to media literacy have included who is going to give the media literacy courses, what qualifications will be sought out in media literacy education teachers, what will be included in the media literacy curriculum in terms of its content, and at what level the media literacy course will be given. The current study which aims to examine media literacy levels of prospective teachers utilized thesurvey method. The sample of the study included prospective teachers (480 attending Elementary School Education, Social Studies Education and Turkish Language Education departments in the Education Faculty at the Dumlupinar University in the 2008-2009 education year. The results of the study showed that prospective teachers have a low level of reaction to media messages, do not educate people around enough about the effects of media, but make use of different sources of media to gain information, and are cognizant of media literacy.

  18. Examining media literacy levels of prospective teachers

    Directory of Open Access Journals (Sweden)

    Taşkın İnan

    2012-03-01

    Full Text Available As in many other countries, following the 2007-2008 education year when media literacy courses began to be included in the curricula, media literacy has become one of the discussion topics among educators and decision makers in Turkey. Discussion topics related to media literacy have included who is going to give the media literacy courses, what qualifications will be sought out in media literacy education teachers, what will be included in the media literacy curriculum in terms of its content, and at what level the media literacy course will be given. The current study which aims to examine media literacy levels of prospective teachers utilized the survey method. The sample of the study included prospective teachers (480 attending Elementary School Education, Social Studies Education and Turkish Language Education departments in the Education Faculty at the Dumlupinar University in the 2008-2009 education year. The results of the study showed that prospective teachers have a low level of reaction to media messages, do not educate people around enough about the effects of media, but make use of different sources of media to gain information, and are cognizant of media literacy.

  19. Transparent meta-analysis of prospective memory and aging.

    Directory of Open Access Journals (Sweden)

    Bob Uttl

    Full Text Available Prospective memory (ProM refers to our ability to become aware of a previously formed plan at the right time and place. After two decades of research on prospective memory and aging, narrative reviews and summaries have arrived at widely different conclusions. One view is that prospective memory shows large age declines, larger than age declines on retrospective memory (RetM. Another view is that prospective memory is an exception to age declines and remains invariant across the adult lifespan. The present meta-analysis of over twenty years of research settles this controversy. It shows that prospective memory declines with aging and that the magnitude of age decline varies by prospective memory subdomain (vigilance, prospective memory proper, habitual prospective memory as well as test setting (laboratory, natural. Moreover, this meta-analysis demonstrates that previous claims of no age declines in prospective memory are artifacts of methodological and conceptual issues afflicting prior research including widespread ceiling effects, low statistical power, age confounds, and failure to distinguish between various subdomains of prospective memory (e.g., vigilance and prospective memory proper.

  20. Prospect relativity: how choice options influence decision under risk.

    Science.gov (United States)

    Stewart, Neil; Chater, Nick; Stott, Henry P; Reimers, Stian

    2003-03-01

    In many theories of decision under risk (e.g., expected utility theory, rank-dependent utility theory, and prospect theory), the utility of a prospect is independent of other options in the choice set. The experiments presented here show a large effect of the available options, suggesting instead that prospects are valued relative to one another. The judged certainty equivalent for a prospect is strongly influenced by the options available. Similarly, the selection of a preferred prospect is strongly influenced by the prospects available. Alternative theories of decision under risk (e.g., the stochastic difference model, multialternative decision field theory, and range frequency theory), where prospects are valued relative to one another, can provide an account of these context effects.

  1. Prospective of petroleum products 2002-2011

    International Nuclear Information System (INIS)

    2002-01-01

    This prospective provides a complete panorama of the requirements in the refining industry of Mexico at short, medium and long terms. Here subjects such as: fuels quality, historical and expected investments and prices, International situation of the installed refining capacity, the demand and regional balance of petroleum products at year 2001, the regulatory framework and the organization of the petroleum sector, the realized investments in the last nine years, Saving programs and efficient use of energy and the applicable regulations to this sector for its optimum use are treated. At the end of this book there are annexes with the abbreviations, acronyms and, conversion factors as well as the fundamental definitions. (Author)

  2. Prospects of nuclear industry in Latin American

    International Nuclear Information System (INIS)

    Brito, S.; Consentino, J.; Eibenschuts, J.; Gasparian, A.E.; Lepecki, W.; Mueller, A.E.F.; Spitalnik, J.

    1984-01-01

    The prospects of nuclear generation in Latin America are presented. It is mentioned that prior to the implementation of a nuclear power programme a legal, organizational and industrial infrastructure has to be developed as a condition for an effetive technology transfer. It is also mentioned that by the expansion of regional cooperation, existing experience and know-how in Latin America nuclear industry, specially regarding small and medium power reactors, could become an important development factor for the whole region. (R.S.) [pt

  3. Atomic prospects in four African states

    International Nuclear Information System (INIS)

    1961-01-01

    A preliminary assistance mission of the International Atomic Energy Agency visited Ghana in March-April this year; members of the mission also visited three other African States: Dahomey, Liberia and Nigeria. As in the case of the six earlier Agency missions of this kind, the visits were made at the request of the Governments of these countries. The purpose was to study at first hand the prospects of atomic development in these countries, to advise the Governments on the broad formulation of atomic energy programs, and to determine how the Agency could assist in the carrying out of these programs

  4. Prospects and challenges for the FPSO

    International Nuclear Information System (INIS)

    Henery, D.; Inglis, R.B.

    1995-01-01

    The reasons for the recent growth of interest in the use of the Floating Production Storage and Off-loading (FPSO) system in oil field developments are examined. An evaluation of oil field characteristics that influence concept selection is made which shows that the FPSO is a very flexible solution in a wide range of situations. Costs and cost drivers are discussed and some measures of cost effectiveness are proposed to serve as benchmarks for the future. Some technology development challenges are identified. The findings give a high level view of the techno-economic prospects for the FPSO in field developments over the next decade

  5. The Development Prospects of Magnetically Levitated Trains

    Directory of Open Access Journals (Sweden)

    Mladen Nikšić

    2012-10-01

    Full Text Available The paper analyses the up-to-date research in developingmagnetically levitated (MAGLEV motorcars. It presents thehistorical overview of the development of the most famousmagnetic levitation systems of today.Apart from describing the operation method and the technicalfeatures of each system, the paper ana(vses the advantagesand drawbacks of certain systems, as well as the advantagesand drawbacks of magnetically levitated motorcars comparedto conventional railway.The paper presents the plans for the future as well as the systemswhich have the highest prospects of being also commerciallyand not just experimentally used.

  6. Food irradiation and its future prospects

    International Nuclear Information System (INIS)

    MacQueen, K.F.

    1967-01-01

    Radiation for food preservation is a way of alleviating problems of food deficiencies in a large part of the world. A review of progress achieved and future prospects was made at the eleventh session of the General Conference in a scientific lecture by Kenneth F. MacQueen, Head of the Food Irradiation Section, Atomic Energy of Canada Ltd. A pioneer in the subject, Mr. MacQueen prepared the petition which led to official acceptance of irradiated potatoes for human consumption in Canada in 1960

  7. Neutron activation analysis in minerals prospecting

    International Nuclear Information System (INIS)

    Gomez, H.; Duque O, J.

    1988-01-01

    One method multielemental analysis in geological samples has been developed by neutron activation analysis without using standards and by eliminating many of the error sources of the absolute method. It uses the ratio of the activities induced by mass unit, between the element in the sample and one cobalt monitor. The detection limits are good for more than thirty elements in many prospecting programs, with a standard deviation less than 7%. The neutron flux used is 2x10 11 nxcm -2 .S -1 and the HPGE detector has a relative efficiency of 20% and an energy resolution of 1.9 KeV in 1332 KeV photopeak

  8. The Telescope Array experiment: status and prospects

    Energy Technology Data Exchange (ETDEWEB)

    Tokuno, H; Cohen, F [Institute for Cosmic Ray Research, University of Tokyo, Kashiwa (Japan); Abbasi, R U; Abu-Zayyad, T; Belz, J W; Blake, S A; Brusova, O; Cady, R; Cao, Z [University of Utah, Salt Lake City (United States); Azuma, R [Tokyo Institute of Technology, Tokyo (Japan); Benno, T; Chikawa, M; Doura, K [Kinki University, Osaka (Japan); Bergman, D R [Rutgers University, Piscataway (United States); Cheon, B G [Hanyang University, Seoul (Korea, Republic of); Chiba, J [Tokyo University of Science, Noda (Japan); Cho, I S [Yonsei University, Seoul (Korea, Republic of); Chung, T [Ewha Womans University, Seoul (Korea, Republic of); Doyle, T [Utah State University, Logan (United States); Endo, A [Saitama University, Saitama (Japan)], E-mail: htokuno@icrr.u-tokyo.ac.jp (and others)

    2008-07-15

    Telescope Array (TA) is a hybrid detector of a surface detector array and fluorescence telescopes. This hybrid detector will measure the energy spectrum, anisotropy and composition of ultra-high energy cosmic rays (UHECRs) to identify their origin. The almost construction of the detector has been completed in May 2007, and the detector is running under test and adjustments. The first hybrid observation with the full configuration is planned in beginning of 2008. In this paper the status and prospects of TA detector is described.

  9. Medicaid prospective payment: Case-mix increase

    Science.gov (United States)

    Baker, Samuel L.; Kronenfeld, Jennie J.

    1990-01-01

    South Carolina Medicaid implemented prospective payment by diagnosis-related group (DRG) for inpatient care. The rate of complications among newborns and deliveries doubled immediately. The case-mix index for newborns increased 66.6 percent, which increased the total Medicaid hospital expenditure 5.5 percent. Outlier payments increased total expenditure further. DRG distribution change among newborns has a large impact on spending because newborn complication DRGs have high weights. States adopting a DRG-based payment system for Medicaid should anticipate a greater increase in case mix than Medicare experienced. PMID:10113463

  10. Prospective needs for decommissioning commercial nuclear facilities

    International Nuclear Information System (INIS)

    Stevens, G.H.; Yasui, M.; Laraia, M.

    1992-01-01

    The answers to the questions: How many reactors will face the end of their operating lifetime over the next few decades? To what extent are the issues of decommissioning urgent? The answers will lead us to those issues that should be tackled now in order to complete smoothly the decommissioning of commercial nuclear power plants. The prospective needs for decommissioning of nuclear power plants are illustrated from the viewpoint of reactor age, and some of the issues to be tackled, in particular by governments, in this century are discussed, to prepare for the future decommissioning activities. (author) 18 refs.; 2 figs.; 2 tabs

  11. Potential Prospects of Turkey in Africa

    OpenAIRE

    Gorgulu, Mehmet Emre

    2010-01-01

    As the global crisis surrounds us, Turkey, as a country with huge prospects, needs to establish new political and commercial links with the rest of the world in order to lessen the effects of the global crisis. This can be a way to take the load off Turkey’s shoulders. These links can be found in the continent Africa. As the host of world’s several fastest growing economies, the continent offers new opportunities for Turkey. These opportunities can be utilized as either in the form of Foreign...

  12. Prospects of the surfatron laser plasma accelerator

    International Nuclear Information System (INIS)

    Katsouleas, T.; Joshi, C.; Mori, W.; Dawson, J.M.

    1983-01-01

    The surfatron concept is proposed as a possible solution to the problem of staging in the laser-plasma beat wave accelerator scheme. Prospects of a 100 GeV particle accelerator based on the surfatron concept are explored. Finite angle optical mixing appears to be a promising solution for drastically reducing the width of the plane wave, thereby, making the required laser power and the device size realizable for a proof-of-principle experiment. Our conclusions are based mainly on analytical theory and one-dimensional particle simulations

  13. The technological prospective of the nuclear sector

    International Nuclear Information System (INIS)

    Schapira, J.P.; Bergeron, J.; Simon, A.; Thomas, J.B.

    2000-06-01

    This prospective analysis of the nuclear park for the period 200-2050 is particularly devoted to scenario of the park evolution, allowing a gradually control of the plutonium inventory and as the same time the minimization of long life radioactive wastes production as the plutonium content. Scenario with multi-recycling illustrate the long dated interest of the reprocessing to acquire and keep the control of the plutonium inventory and decrease the volume and the possible radiotoxicity of ultimate wastes and to optimize the use of natural energy resources in the perspective of the nuclear energy contribution to the sustainable development. (A.L.B.)

  14. Application of solar chargers to prospection instruments

    International Nuclear Information System (INIS)

    Caille, G.

    1960-01-01

    The use of conventional batteries has certain disadvantages, and for this reason high-voltage batteries have been gradually replaced in all prospection instruments by transistor supply systems, using less cumbersome sources of energy. All the same low voltages are still necessary, and in hot or damp countries the use of these batteries leads to consumptions out of all proportion to the services rendered. This is why the use of solar energy possesses real advantages. After a brief review of the basic ideas on semiconductors, this article describes a selenium solar battery which was developed by the Westinghouse brakes and signals society. (author) [fr

  15. Coal industry - problems and prospects. [United Kingdom

    Energy Technology Data Exchange (ETDEWEB)

    Siddall, N

    1984-01-01

    Presidential Address by Sir Norman Siddall is presented which considers the problems and prospects facing the UK coal industry. The range of changes which business management is subject to are outlined together with the coal industry's response to these changes. Fluctuations in the energy market and the economy have resulted in a customer orientated approach to marketing, and improved efficiency throughout the industry. New technology has increased the efficiency of some aspects of operations but at the some time developments in the areas of industrial relations and public accountability have limited management's ability to respond to changes in the commercial environment.

  16. Prospects of protected ground in Russia

    Directory of Open Access Journals (Sweden)

    M. I. Mamedov

    2014-01-01

    Full Text Available The article analyzes the current state and prospects of  protected  ground development in the Russian Federation based on the data of the Ministry  of Agriculture and  the Federal State Statistics Service. The indexes of production of vegetable crops in different regions of the  Russian Federation are given. The problems, which  are  holding back the greenhouse business, are  discussed. The possibilities of increasing the  area of protected ground and vegetable production are shown.

  17. Higgs results and prospects at ATLAS

    International Nuclear Information System (INIS)

    Rosati, S.

    2015-01-01

    Highlights of a selection of the recent results of Run-1 measurements of the Higgs boson properties, with the ATLAS experiment at LHC, are presented. The results have been obtained with up to 25 fb −1 of proton-proton collisions at center of mass energy of 7 and 8TeV. Prospects in the field of Higgs properties measurements, with the data that will be collected at the future LHC runs, with up to 3000 fb −1 , are also discussed.

  18. A prospect theory perspective on terrorism

    Directory of Open Access Journals (Sweden)

    Cind Du Bois

    2017-06-01

    Full Text Available This paper presents a new approach for the study of terrorist behaviour and argues that a framework based on Prospect Theory can provide novel, useful insights into the understanding of the terrorist mind-set. Such a framework allows different pathways to become a terrorist and although individual decisions are studied, the model also takes into account environmental factors. By changing these environmental factors and/or framing the choice differently, PT provides insights as to how the terrorist group and/or a charismatic leader can influence the individual’s whether or not to turn to terrorism.

  19. Panel discussion on prospects for fusion power

    International Nuclear Information System (INIS)

    Sheffield, J.

    1986-01-01

    Although substantial progress is made every year in fusion research, the projected time to realize the ultimate goal of commercial fusion always seems to be 25 to 30 years away. This shifting schedule reflects the underlying difficulty of developing fusion. Every new technology improves the prospects for success, yet as each fusion mountain is scaled, it serves mainly to bring a better view of the next mountain. Two questions are considered: (1) why are so many configurations studied, and (2) what constitutes an economic power density

  20. Development environmental attitude of prospective science teachers

    International Nuclear Information System (INIS)

    Iqbal, H.M.

    2000-01-01

    Since the last three decades or so, we have witnessed the growing concern of human beings, all over the world, to adopt measures to conserve and preserve environment of the planet earth, because the same has been threatened by human activity and by way of our unparalleled intervention in the otherwise balanced environment. This awareness and concern has emerged as a need of incorporating environmental Issues into the normal curricula, so that we can educate the young generation to become informed decision-makers of the future. UNESCO and UNEP have advocated (since the last three decades) to teach environmentalised science to students. In Pakistan, there have been attempts to change curricula in accordance with the need of the time. Teachers need new kinds of skills, attitudes and commitment to teach science in an environmentalised fashion. This article discusses the impact of a semester-course on change in environmental attitudes of prospective science-teachers. A pre-test, post-test method was used to ascertain any change in environmental attitude of prospective science-teachers, after studying the environmental education course. It has been shown that there was a change in the environmental attitude of science-teachers as a result of the one-semester course, but the change or the level of attitude was not substantial or satisfactory. There seems to be a need of adopting a comprehensive approach to environmental education, and introducing teaching of environmental concepts at a very early age. (author)

  1. Nuclear energy : Present situation and future prospects

    International Nuclear Information System (INIS)

    Gray, J.E.

    1986-01-01

    In 1953, President Eisenhower announced the U.S. ''Atoms for Peace'' program. After slightly more than 30 years, there are in operation, under construction or on order more than 400,000 MW of commercial nuclear power generation capacity located in 35 nations, representing a total investment around a trillion U.S. dollars. The situation is noteworthy in terms of the rate of technical development, deployment and transfer, the magnitude of the financial investment, economic benefits, the favorable impact on public health and safety, and the usual and positive character of cooperation among all concerned. The fundamentals of nuclear power generation with regard to economics, safety and environmental impact are likely to favor the increased use of nuclear power. The future prospect of the nuclear power in the U.S. also will be clarified positively. In many ways, U.S. commercial nuclear power continues to benefit from the Navy nuclear propulsion program. The prospect of supply demand situation in the conversion, enrichment and fabrication of uranium fuel is explained. The amount of spent fuel arising in OECD countries and their storage capability up to 2000 are shown, and the storage capability projected is well in excess. (Kako, I.)

  2. Prospective Lymphedema Surveillance in a Clinic Setting

    Directory of Open Access Journals (Sweden)

    Janet Chance-Hetzler

    2015-08-01

    Full Text Available The potential impact of breast cancer-related lymphedema (LE is quite extensive, yet it often remains under-diagnosed until the later stages. This project examines the effectiveness of prospective surveillance in post-surgical breast cancer patients. A retrospective analysis of 49 out of 100 patients enrolled in a longitudinal prospective study at a Midwestern breast center evaluates: (1 time required for completion of bilateral limb measurements and Lymphedema Breast Cancer Questionnaire (LBCQ; (2 referral to LE management with limb volume increase (LVI and/or LBCQ symptoms; and (3 cost of LE management at lower LVI (≥5%–≤10% versus traditional (≥10%. Findings revealed a visit timeframe mean of 40.3 min (range = 25–60; 43.6% of visits were ≤30-min timeframe. Visit and measurement times decreased as clinic staff gained measurement experience; measurement time mean was 17.9 min (range = 16.9–18.9. LBCQ symptoms and LVI were significantly (p < 0.001 correlated to LE referral; six of the nine patients referred (67% displayed both LBCQ symptoms/LVI. Visits with no symptoms reported did not result in referral, demonstrating the importance of using both indicators when assessing early LE. Lower threshold referral provides compelling evidence of potential cost savings over traditional threshold referral with reported costs of: $3755.00 and $6353.00, respectively (40.9% savings.

  3. Roboethics: Fundamental Concepts and Future Prospects

    Directory of Open Access Journals (Sweden)

    Spyros G. Tzafestas

    2018-06-01

    Full Text Available Many recent studies (e.g., IFR: International Federation of Robotics, 2016 predict that the number of robots (industrial, service/social, intelligent/autonomous will increase enormously in the future. Robots are directly involved in human life. Industrial robots, household robots, medical robots, assistive robots, sociable/entertainment robots, and war robots all play important roles in human life and raise crucial ethical problems for our society. The purpose of this paper is to provide an overview of the fundamental concepts of robot ethics (roboethics and some future prospects of robots and roboethics, as an introduction to the present Special Issue of the journal Information on “Roboethics”. We start with the question of what roboethics is, as well as a discussion of the methodologies of roboethics, including a brief look at the branches and theories of ethics in general. Then, we outline the major branches of roboethics, namely: medical roboethics, assistive roboethics, sociorobot ethics, war roboethics, autonomous car ethics, and cyborg ethics. Finally, we present the prospects for the future of robotics and roboethics.

  4. Expression of future prospective in indirect speech

    Directory of Open Access Journals (Sweden)

    Bodnaruk Elena Vladimirovna

    2015-03-01

    Full Text Available The article analyzes the characteristics and use of grammatical semantics and lexical and grammatical means used to create future prospects in double indirect discourse. The material for the study were epic works by contemporary German writers. In the analysis of the empirical material it has been pointed out that indirect discourse has preterial basis and is the kind of most frequent inner speech of characters. The most widely used form with future semantics in preterial indirect speech is conditional I, formally having a conjunctive basis, but is mostly used with the indicative semantics. Competitive to conditional I in indirect speech is preterial indicative. A characteristic feature of the indirect speech is the use of modal verbs, which, thanks to its semantics is usually referred as an action at a later term, creating the prospect of future statements. The most frequent were modal verbs wollen and sollen in the form of the preterite, more rare verbs were m ssen and k nnen. German indirect speech distinguishes the ability to use forms on the basis of conjunctive: preterite and plusquamperfect of conjunctive. Both forms express values similar to those of the indicative. However, conjunctive forms the basis of the data shown in a slightly more pronounced seme of uncertainty that accompanies future uses of these forms in indirect speech. In addition, plusquamperfect conjunctive differs from others by the presence of the seme of completeness.

  5. Thorium: Issues and prospects in Malaysia

    Energy Technology Data Exchange (ETDEWEB)

    AL-Areqi, Wadeeah M.; Majid, Amran Ab.; Sarmani, Sukiman; Bahri, Che Nor Aniza Che Zainul [Nuclear Science Programme, School of Applied Physics, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Malaysia. walareqi@yahoo.com (Malaysia)

    2015-04-29

    In Malaysia, thorium exists in minerals and rare earth elements production residue. The average range of thorium content in Malaysian monazite and xenotime minerals was found about 70,000 and 15,000 ppm respectively. About 2,636 tonnes of Malaysian monazite was produced for a period of 5 years (2006-2010) and based on the above data, it can be estimated that Malaysian monazite contains about 184.5 tonnes of thorium. Although thorium can become a major radiological problem to our environment, but with the significant deposit of thorium in Malaysian monazite, it has a prospect as a future alternative fuel in nuclear technology. This paper will discuss the thorium issues in Malaysia especially its long term radiological risks to public health and environment at storage and disposal stages, the prospect of exploring and producing high purity thorium from our rare earth elements minerals for future thorium based reactor. This paper also highlights the holistic approach in thorium recovery from Malaysian rare earth element production residue to reduce its radioactivity and extraction of thorium and rare earth elements from the minerals with minimum radiological impact to health and environment.

  6. Thorium: Issues and prospects in Malaysia

    International Nuclear Information System (INIS)

    AL-Areqi, Wadeeah M.; Majid, Amran Ab.; Sarmani, Sukiman; Bahri, Che Nor Aniza Che Zainul

    2015-01-01

    In Malaysia, thorium exists in minerals and rare earth elements production residue. The average range of thorium content in Malaysian monazite and xenotime minerals was found about 70,000 and 15,000 ppm respectively. About 2,636 tonnes of Malaysian monazite was produced for a period of 5 years (2006-2010) and based on the above data, it can be estimated that Malaysian monazite contains about 184.5 tonnes of thorium. Although thorium can become a major radiological problem to our environment, but with the significant deposit of thorium in Malaysian monazite, it has a prospect as a future alternative fuel in nuclear technology. This paper will discuss the thorium issues in Malaysia especially its long term radiological risks to public health and environment at storage and disposal stages, the prospect of exploring and producing high purity thorium from our rare earth elements minerals for future thorium based reactor. This paper also highlights the holistic approach in thorium recovery from Malaysian rare earth element production residue to reduce its radioactivity and extraction of thorium and rare earth elements from the minerals with minimum radiological impact to health and environment

  7. Thorium: Issues and prospects in Malaysia

    Science.gov (United States)

    AL-Areqi, Wadeeah M.; Majid, Amran Ab.; Sarmani, Sukiman; Bahri, Che Nor Aniza Che Zainul

    2015-04-01

    In Malaysia, thorium exists in minerals and rare earth elements production residue. The average range of thorium content in Malaysian monazite and xenotime minerals was found about 70,000 and 15,000 ppm respectively. About 2,636 tonnes of Malaysian monazite was produced for a period of 5 years (2006-2010) and based on the above data, it can be estimated that Malaysian monazite contains about 184.5 tonnes of thorium. Although thorium can become a major radiological problem to our environment, but with the significant deposit of thorium in Malaysian monazite, it has a prospect as a future alternative fuel in nuclear technology. This paper will discuss the thorium issues in Malaysia especially its long term radiological risks to public health and environment at storage and disposal stages, the prospect of exploring and producing high purity thorium from our rare earth elements minerals for future thorium based reactor. This paper also highlights the holistic approach in thorium recovery from Malaysian rare earth element production residue to reduce its radioactivity and extraction of thorium and rare earth elements from the minerals with minimum radiological impact to health and environment.

  8. Forestry: Prospective Scenarios for Generating Eletricity

    Directory of Open Access Journals (Sweden)

    Henrique Dias Blois

    2017-05-01

    Full Text Available Forestry generates in all production segments a lot of waste which is a potential power source and an opportunity for electricity generation by the use of this material. Therefore, this study represents the construction of future scenarios for the power generation sector from alternative and renewable sources in the region of Vale do Taquari and Alto da Serra do Botucaraí, in the Northern-Central region of the Stat of Rio Grande do Sul, aiming for the application of waste and by-products from forestry present in a intensive and tendentious way in economic activities within the region. By way of prospective scenarios, one will be able to observe which events are impactful on the viability of an environmental project for recovery of forestry waste to generate electricity in the region. Thereby, we used the method described by Grumbach (2000, a methodology that prospects scenarios from the participation of experts, who collaborated analyzing and proposing events that impact as strengths and weaknesses, opportunities and threats and their interrelationships. Also, it was evident the degree of influence and dependence between the events, which create a matrix of cross impacts. Moreover, possible future scenarios have been constructed and analyzed for demonstrating that the study area has potential events that could serve as alternatives to the sector. However, no ideal scenario has been identified for the next five years, a fact that is due to the large amount of adverse events in six out of the ten final events.

  9. A Prospective Evaluation of Helical Tomotherapy

    International Nuclear Information System (INIS)

    Bauman, Glenn; Yartsev, Slav; Rodrigues, George; Lewis, Craig; Venkatesan, Varagur M.; Yu, Edward; Hammond, Alex; Perera, Francisco; Ash, Robert; Dar, A. Rashid; Lock, Michael; Baily, Laura; Coad, Terry C; Trenka, Kris C.; Warr, Barbara; Kron, Tomas; Battista, Jerry; Van Dyk, Jake

    2007-01-01

    Purpose: To report results from two clinical trials evaluating helical tomotherapy (HT). Methods and Materials: Patients were enrolled in one of two prospective trials of HT (one for palliative and one for radical treatment). Both an HT plan and a companion three-dimensional conformal radiotherapy (3D-CRT) plan were generated. Pretreatment megavoltage computed tomography was used for daily image guidance. Results: From September 2004 to January 2006, a total of 61 sites in 60 patients were treated. In all but one case, a clinically acceptable tomotherapy plan for treatment was generated. Helical tomotherapy plans were subjectively equivalent or superior to 3D-CRT in 95% of plans. Helical tomotherapy was deemed equivalent or superior in two thirds of dose-volume point comparisons. In cases of inferiority, differences were either clinically insignificant and/or reflected deliberate tradeoffs to optimize the HT plan. Overall imaging and treatment time (median) was 27 min (range, 16-91 min). According to a patient questionnaire, 78% of patients were satisfied to very satisfied with the treatment process. Conclusions: Helical tomotherapy demonstrated clear advantages over conventional 3D-CRT in this diverse patient group. The prospective trials were helpful in deploying this technology in a busy clinical setting

  10. Prospective and retrospective timing by pigeons.

    Science.gov (United States)

    Fetterman, J Gregor; Killeen, P Richard

    2010-05-01

    Pigeons discriminated between two pairs of durations: a short set (2.5 and 5 sec) and a long set (5 and 10 sec). The pairs were intermixed within sessions and identified by the colors on the signal and choice keys. Once the task was learned, the pigeons experienced the following three conditions seriatim: (1) The signal key was made ambiguous about the test change, but the choice keys were informative (retrospective); (2) the signal key identified the test range, but the choice keys did not (prospective); (3) probe trials were introduced in which the color of the center key signaled one test range, but the color of the choice keys signaled the other test range (inconsistent). Accuracy of choice decreased in the retrospective condition and, returned to baseline levels, was higher under the prospective condition than under the retrospective condition. In a final condition, referred to as conflict trials, the center-key color signified one test range and the choice-key colors the other range. The results from these conflict-inconsistent tests indicate that choice behavior was largely controlled by the signal-key color and not by the choice-key color. We relate these findings to different approaches to timing in animals.

  11. Discussion on some problems in uranium hydrogeochemical prospecting

    International Nuclear Information System (INIS)

    Shi Weijun.

    1989-01-01

    The requirements for sampling density in uranium hydrogeochemical prospecting are discussed in this paper. The scales for regional hydrogeochemical survey, prospetcing survey and detailed prospecting survey are 1 : 200,000 - 1 : 100,000, 1 : 50,000 - 1 : 25,000 and 1 : 10,000 - 1 : 5,000 respectively. On the basis of explanation to the geological meaning of hydrogeochemical field defined in different stage, the principle, effect and technical requirements of small-medium scale hydrogeochemical prospecting are studied. The reason and advantage of the dispersion train prospecting using in the wet and rainy regions have been suggested. The key to the dispersion train prospecting is the sensitivity and precision of analytic methods. The general indications and salinity (conductivity) should be paid attention to in hydrogeochemical prospecting

  12. Loads and loads and loads: The influence of prospective load, retrospective load, and ongoing task load in prospective memory

    Directory of Open Access Journals (Sweden)

    Beat eMeier

    2015-06-01

    Full Text Available In prospective memory tasks different kinds of load can occur. Adding a prospective memory task can impose a load on ongoing task performance. Adding ongoing task load can affect prospective memory performance. The existence of multiple target events increases prospective load and adding complexity to the to-be-remembered action increases retrospective load. In two experiments, we systematically examined the effects of these different types of load on prospective memory performance. Results showed an effect of prospective load on costs in the ongoing task for categorical targets (Experiment 2, but not for specific targets (Experiment 1. Retrospective load and ongoing task load both affected remembering the retrospective component of the prospective memory task. We suggest that prospective load can enhance costs in the ongoing task due to additional monitoring requirements. Retrospective load and ongoing task load seem to impact the division of resources between the ongoing task and retrieval of the retrospective component, which may affect disengagement from the ongoing task. In general, the results demonstrate that the different types of load affect prospective memory differentially.

  13. Prospects of the high power iodine laser

    International Nuclear Information System (INIS)

    Hohla, K.; Brederlow, G.; Fill, E.; Volk, R.; Witte, K.J.

    1976-09-01

    The characteristic properties of the iodine laser (gaseous laser substance, photolytic pump mechanism, variable stimulated emission cross-section) made it possible in a relatively short time to generate ns pulses in the kJ range. The Asterix II and III iodine laser systems at IPP are working successfully, and the question arises what prospects are afforded for further iodine laser development. What are the problems that have to be clarified in order to build 10 or 100 kJ systems for laser fusion experiments. According to our experience these can be classified as follows: 1) Short pulse generation and contrast ratio, 2) pulse shaping in a high-gain laser and amplification in the coherent time range, 3) non-linear properties at high intensities, 4) scalable pumping schemes and chemical processes. (orig./WL) [de

  14. PROSPECTIVE ROMANIAN LEADERS' VIEW ON LEADERSHIP DIMENSIONS

    Directory of Open Access Journals (Sweden)

    CATANA DOINA

    2010-07-01

    Full Text Available This study deals with Romanian prospective leaders' view on outstanding leadership dimensions (styles. It is a part of a European research project, GLOBE Students, dealing with the interrelations between societal culture and leadership. The basic theoretical constructs and methodological framework of investigation are those developed by GLOBE international research project. The sample consists in 429 students in business/economics and engineering, belonging to three Romanian universities. The findings show that the most preferred leadership styles are team oriented and charismatic (value based. Only a few leadership styles seem to have weak, but statistically significant correlations against a sig. = 0.50 probability threshold with important socialization agents for the students.

  15. Prospects of High Energy Laboratory Astrophysics

    International Nuclear Information System (INIS)

    Ng, Johnny S.T.; SLAC

    2006-01-01

    Ultra high energy cosmic rays (UHECR) have been observed but their sources and production mechanisms are yet to be understood. We envision a laboratory astrophysics program that will contribute to the understanding of cosmic accelerators with efforts to: (1) test and calibrate UHECR observational techniques, and (2) elucidate the underlying physics of cosmic acceleration through laboratory experiments and computer simulations. Innovative experiments belonging to the first category have already been done at the SLAC FFTB. Results on air fluorescence yields from the FLASH experiment are reviewed. Proposed future accelerator facilities can provided unprecedented high-energy-densities in a regime relevant to cosmic acceleration studies and accessible in a terrestrial environment for the first time. We review recent simulation studies of nonlinear plasma dynamics that could give rise to cosmic acceleration, and discuss prospects for experimental investigation of the underlying mechanisms

  16. Development and Prospect of Nanoarchitectured Solar Cells

    Directory of Open Access Journals (Sweden)

    Bo Zhang

    2015-01-01

    Full Text Available This paper gives an overview of the development and prospect of nanotechnologies utilized in the solar cell applications. Even though it is not clearly pointed out, nanostructures indeed have been used in the fabrication of conventional solar cells for a long time. However, in those circumstances, only very limited benefits of nanostructures have been used to improve cell performance. During the last decade, the development of the photovoltaic device theory and nanofabrication technology enables studies of more complex nanostructured solar cells with higher conversion efficiency and lower production cost. The fundamental principles and important features of these advanced solar cell designs are systematically reviewed and summarized in this paper, with a focus on the function and role of nanostructures and the key factors affecting device performance. Among various nanostructures, special attention is given to those relying on quantum effect.

  17. The first signs of prospective memory.

    Science.gov (United States)

    Ślusarczyk, Elżbieta; Niedźwieńska, Agnieszka; Białecka-Pikul, Marta

    2018-06-05

    We conducted a study to examine the impact of motivation and length of delay on performance on prospective memory (PM) tasks in 2-year of children. A total of 158 children aged exactly 24 months were asked to perform a naturalistic PM task. Length of delay (10 min; 35 min) and motivation (high; very high) were between-subjects factors. Two thirds of children had to be excluded from the analysis because of poor retrospective memory for the PM task instructions which were no longer remembered at the end of the session. For the children who did remember the instructions, both motivation and delay had significant effects on PM. Also, their PM performance was reliably above zero, even after the long delay. The findings indicate that when children as young as 24 months are able to remember the PM task instructions they can reliably succeed in PM tasks that are intrinsically motivating for them.

  18. Moon Prospective Energy and Material Resources

    CERN Document Server

    2012-01-01

    The Earth has limited material and energy resources. Further development of the humanity will require going beyond our planet for mining and use of extraterrestrial mineral resources and search of power sources. The exploitation of the natural resources of the Moon is a first natural step on this direction. Lunar materials may contribute to the betterment of conditions of people on Earth but they also may be used to establish permanent settlements on the Moon. This will allow developing new technologies, systems and flight operation techniques to continue space exploration.   In fact, a new branch of human civilization could be established permanently on Moon in the next century. But, meantime, an inventory and proper social assessment of Moon’s prospective energy and material resources is required. This book investigates the possibilities and limitations of various systems supplying manned bases on Moon with energy and other vital resources. The book collects together recent proposals and innovative optio...

  19. Prospects for neutron-antineutron transition search

    International Nuclear Information System (INIS)

    Kamyshkov, Y.; Tennessee Univ., Knoxville, TN

    1996-01-01

    Presently-available sources of free neutrons can allow an improvement in the discovery potential of a neutron-antineutron transition search by four orders of magnitude as compared to that of the most recent reactor-based search experiment performed at ILL in Grenoble. This would be equivalent to a characteristic neutron-antineutron transition time limit of >10 10 seconds. With future dedicated neutron-source Facilities, with further progress in cold-neutron- moderator techniques, and with a vertical experiment layout, the discovery potential could ultimately be pushed by another factor of ∼100 corresponding to a characteristic transition time limit of ∼10 11 seconds. Prospects for, and relative merits of, a neutron-antineutron oscillation search in intranuclear transitions are also discussed

  20. Earth Rotation Dynamics: Review and Prospects

    Science.gov (United States)

    Chao, Benjamin F.

    2004-01-01

    Modem space geodetic measurement of Earth rotation variations, particularly by means of the VLBI technique, has over the years allowed studies of Earth rotation dynamics to advance in ever-increasing precision, accuracy, and temporal resolution. A review will be presented on our understanding of the geophysical and climatic causes, or "excitations", for length-of-day change, polar motion, and nutations. These excitations sources come from mass transports that constantly take place in the Earth system comprised of the atmosphere, hydrosphere, cryosphere, lithosphere, mantle, and the cores. In this sense, together with other space geodetic measurements of time-variable gravity and geocenter motion, Earth rotation variations become a remote-sensing tool for the integral of all mass transports, providing valuable information about the latter on a wide range of spatial and temporal scales. Future prospects with respect to geophysical studies with even higher accuracy and resolution will be discussed.

  1. Prospects in MPGDs development for neutron detection

    CERN Document Server

    Guerard, Bruno; Murtas, Fabrizio

    2014-01-01

    Compared to Multi Wires Proportional Chambers (MWPC), Micro-Pattern Gas Detectors (MPGD) used in HEP to detect MIPs offer better spatial resolution, counting rate capability, and radiation hardness; their fabrication is also more reproducible. Provided similar advantages are applicable to detect neutrons, MPGDs might contribute significantly to the development of neutron scientific instrumentation. In order to evaluate the prospects of neutron MPGDs, it is worth knowing the applications which would benefit from a gain in performance, and if they offer a competitive alternative to conventional 3He detectors. These questions have been at the focus of the workshop "Neutron Detection with Micro-Pattern Gaseous Detectors" organized by RD51 in collaboration with HEPTech, which took place at CERN on October 14-15, 2013. The goal of this workshop was to help disseminating MPGD technologies beyond High Energy Physics, and to give the possibility to academic institutions, potential users and industry to meet together. ...

  2. Nuclear material management: challenges and prospects

    International Nuclear Information System (INIS)

    Rieu, J.; Besnainou, J.; Leboucher, I.; Chiguer, M.; Capus, G.; Greneche, D.; Durret, L.F.; Carbonnier, J.L.; Delpech, M.; Loaec, Ch.; Devezeaux de Lavergne, J.G.; Granger, S.; Devid, S.; Bidaud, A.; Jalouneix, J.; Toubon, H.; Pochon, E.; Bariteau, J.P.; Bernard, P.; Krellmann, J.; Sicard, B.

    2008-01-01

    The articles in this dossier were derived from the papers of the yearly S.F.E.N. convention, which took place in Paris, 12-13 March 2008. They deal with the new challenges and prospects in the field of nuclear material management, throughout the nuclear whole fuel cycle, namely: the institutional frame of nuclear materials management, the recycling, the uranium market, the enrichment market, the different scenarios for the management of civil nuclear materials, the technical possibilities of spent fuels utilization, the option of thorium, the convention on the physical protection of nuclear materials and installations, the characterisation of nuclear materials by nondestructive nuclear measurements, the proliferation from civil installations, the use of plutonium ( from military origin) and the international agreements. (N.C.)

  3. The UFE Prospective scenarios for energy demand

    International Nuclear Information System (INIS)

    2013-01-01

    After an overview of the French energy consumption in 2011 (final energy consumption, distribution of CO 2 emissions related to energy consumption), this Power Point presentation proposes graphs and figures illustrating UFE's prospective scenarios for energy demand. The objective is to foresee energy demand in 2050, to study the impact of possible actions on energy demand, and to assess the impact on greenhouse gas emissions. Hypotheses relate to demographic evolution, economic growth, energy intensity evolution, energy efficiency, and use transfers. Factors of evolution of energy demand are discussed: relationship between demography and energy consumption, new uses of electricity (notably with TICs), relationship between energy intensity and economic growth. Actions on demand are discussed. The results of different scenarios of technical evolution are presented

  4. Prospects of joining multi-material structures

    Science.gov (United States)

    Sankaranarayanan, R.; Hynes, N. Rajesh Jesudoss

    2018-05-01

    Spring up trends and necessities make the pipelines for the brand new Technologies. The same way, Multimaterial structures emerging as fruitful alternatives for the conventional structures in the manufacturing sector. Especially manufacturing of transport vehicles is placing a perfect platform for these new structures. Bonding or joining technology plays a crucial role in the field of manufacturing for sustainability. These latest structures are purely depending on such joining technologies so that multi-material structuring can be possible practically. The real challenge lies on joining dissimilar materials of different properties and nature. Escalation of thermoplastic usage in large structural components also faces similar ambiguity for joining multi-material structures. Adhesive bonding, mechanical fastening and are the answering technologies for multi-material structures. This current paper analysis the prospects of these bonding technologies to meet the challenges of tomorrow.

  5. Prospects for recovering gallium from extracted coal

    Energy Technology Data Exchange (ETDEWEB)

    Ratynskiy, V M; Reznik, A M; Zekel, L A; Zharov, Yu N

    1979-01-01

    The authors conducted research in order to establish the physical-chemical mechanisms governing the behavior of rare and dispersed elements within the thermal treatment processes used to treat coal and enrichment waste. New means are proposed for obtaining concentrations of gallium. These methods are under consideration primarily for the isolation of gallium as a by-product during the production of aggloporite from coal waste. The authors examine in detail the results of research dealing with the transfer of gallium compounds in a solution, the extraction of gallium from solutions, the separation of impurities from gallium, and the isolation of gallium from extract. Utilizing research results, the authors determine the expenditure coefficient and costs for additives used to extract gallium from waste by-products. The realization of this gallium extraction process from those products having the best prospects for gallium content resulted in economic savings.

  6. PROSPECTIVE LEADERS' VIEW ON ROMANIAN SOCIETAL CULTURE

    Directory of Open Access Journals (Sweden)

    CATANA GHEORGHE ALEXANDRU

    2010-07-01

    Full Text Available This study deals with Romanian prospective leaders’ perceptions and expectations concerning the societal culture. It is a part of a European research project, GLOBE Students, dealing with the interrelations between societal culture and leadership. The basic theoretical constructs and methodological framework of investigation are those developed by GLOBE international research project. In adapting our research to student population peculiarities, GLOBE Beta questionnaire was altered through adding new items (scales. The sample consists in 429 students in business/economics and engineering, belonging to three Romanian universities. The findings show that in student’s opinion there are significant differences between societal culture practices and values (expectations on all nine cultural dimensions in GLOBE model.

  7. [Valuation and prospect of function preserving gastrectomy].

    Science.gov (United States)

    Wang, Shuchang; Yu, Site; Xu, Jia; Zhao, Gang

    2017-10-25

    Preserving gastric function and improving quality of life (QOL) is the tendency of surgery for early gastric cancer. Function preserving gastrectomy (FPG) is applied to modify the extent of surgery and to achieve better quality of life at the premise of radical resection. Pylorus-preserving gastrectomy is the most favorable approach of FPG with oncological safety, which can improve nutritional status and QOL via preserving pylorus and vagal nerve. Proximal gastrectomy is widely accepted as FPG for early upper 1/3 gastric cancer. However, the most optimal way of anastomosis is not yet solved. Sentinel node navigation is currently the most accurate approach for intraoperative diagnosis of lymph node metastasis, which stimulates the development of many kinds of FPG procedures for individual treatment. Nevertheless, more efforts should be made to reduce false negative rate of sentinel node biopsy. Herein we discuss the valuation and prospect of FPG.

  8. Reproducibility principles, problems, practices, and prospects

    CERN Document Server

    Maasen, Sabine

    2016-01-01

    Featuring peer-reviewed contributions from noted experts in their fields of research, Reproducibility: Principles, Problems, Practices, and Prospects presents state-of-the-art approaches to reproducibility, the gold standard sound science, from multi- and interdisciplinary perspectives. Including comprehensive coverage for implementing and reflecting the norm of reproducibility in various pertinent fields of research, the book focuses on how the reproducibility of results is applied, how it may be limited, and how such limitations can be understood or even controlled in the natural sciences, computational sciences, life sciences, social sciences, and studies of science and technology. The book presents many chapters devoted to a variety of methods and techniques, as well as their epistemic and ontological underpinnings, which have been developed to safeguard reproducible research and curtail deficits and failures. The book also investigates the political, historical, and social practices that underlie repro...

  9. Asteroids prospective energy and material resources

    CERN Document Server

    2013-01-01

    The Earth has limited material and energy resources while these resources in space are virtually unlimited. Further development of humanity will require going beyond our planet and exploring of extraterrestrial resources and sources of unlimited power.   Thus far, all missions to asteroids have been motivated by scientific exploration. However, given recent advancements in various space technologies, mining asteroids for resources is becoming ever more feasible. A significant portion of asteroids value is derived from their location; the required resources do not need to be lifted at a great expense from the surface of the Earth.   Resources derived from Asteroid not only can be brought back to Earth but could also be used to sustain human exploration of space and permanent settlements in space.   This book investigates asteroids' prospective energy and material resources. It is a collection of topics related to asteroid exploration, and utilization. It presents past and future technologies and solutions t...

  10. Prospects for antiproton physics, my perspective

    International Nuclear Information System (INIS)

    Oelert, Walter

    2012-01-01

    These closing remarks are not supposed to be a summary talk, for this please have a look to the individual contributions to be published in the proceedings, but rather some considerations on future prospects for antiproton physics. However, first I would like to appreciate the organizers idea for giving me the opportunity to thank them for a well balanced, exciting and interesting conference LEAP-2011 in this marvelous city of Vancouver. I am sure we all loved to be here and enjoyed the hospitality and the bond of friendship we could experience during these days. We appreciate the patience and help of all the local organizers where I especially would like to mention Jana Thomson for her endless and helpful assignment. Thank you all—the participants, the speakers, the conference chair, the sponsors—for making this conference a success and we are looking forward to the next occasion in this series of meetings which will be celebrated in Uppsala.

  11. Endodontic flare-ups: a prospective study.

    Science.gov (United States)

    Alves, Vanessa de Oliveira

    2010-11-01

    The objective of this prospective clinical study was to evaluate the incidence of flare-ups (pain and/or swelling requiring endodontic interappointment and emergency treatment) and identify the risk factors associated with their occurrence in patients who received endodontic treatment from June 2006 to June 2007 at the endodontics clinic of the São Paulo Dental Association (APCD), Jardim Paulista branch, São Paulo, Brazil. The incidence of flare-ups was 1.71% out of 408 teeth that had received endodontic therapy. Statistical analysis using the chi-squared test (P flare-up rate and the presence of a periradicular radiolucency. Copyright © 2010 Mosby, Inc. All rights reserved.

  12. The world nuclear market and its prospects

    International Nuclear Information System (INIS)

    Anon.

    2010-07-01

    This market study of the nuclear industry presents: 1 - the dynamics of nuclear markets: organisation of the nuclear industry (fuel cycle, reactors), market analysis and key figures (uranium production, conversion and enrichment, fuel fabrication, reactor manufacturing, spent fuel reprocessing), strengths in presence and competition structure (companies ranking, market shares, positioning); 2 - nuclear renaissance and its basis: a suitable answer to the present day energy and environmental challenges (carbon-free energy and low volatility of fuel price), conjunction of favourable conditions (security of fuel supplies, political support, necessity of plants renewal), three main uncertainties (waste management, safety aspect, public opinion weight); 3 - perspectives of development at the 2030 prospects: data (scope of renaissance, market size), sector reconfiguration scenarios (evolution of competition, reconfiguration paths, concentration trend); 4 - analysis of the strategy of 13 companies, suppliers of the nuclear industry, with their key figures, positioning and strategy (production capacity, partnerships, external growth investments, new technical developments etc.). (J.S.)

  13. The prospects for dry fuel storage

    International Nuclear Information System (INIS)

    Harris, G.G.; Elliott, D.

    1994-01-01

    Dry storage of spent nuclear fuels is one method of dealing with radioactive waste. This article reports from a one day seminar on future prospects for dry fuel storage held in November 1993. Dry storage in an inert gas or air environment in vaults or casks, is an alternative to wet storage in water-filled ponds. Both wet and dry storage form part of the Interim Storage option for radioactive waste materials, and form alternatives to reprocessing or direct disposal in a deep repository. It has become clear that a large market for dry fuel storage will exist in the future. It will therefore be necessary to ensure that the various technical, safety, commercial, legislative and political constraints associated with it can be met effectively. (UK)

  14. Prospects for antiproton physics, my perspective

    Energy Technology Data Exchange (ETDEWEB)

    Oelert, Walter, E-mail: w.oelert@fz-juelich.de [Forschungszentrum Juelich (Germany)

    2012-12-15

    These closing remarks are not supposed to be a summary talk, for this please have a look to the individual contributions to be published in the proceedings, but rather some considerations on future prospects for antiproton physics. However, first I would like to appreciate the organizers idea for giving me the opportunity to thank them for a well balanced, exciting and interesting conference LEAP-2011 in this marvelous city of Vancouver. I am sure we all loved to be here and enjoyed the hospitality and the bond of friendship we could experience during these days. We appreciate the patience and help of all the local organizers where I especially would like to mention Jana Thomson for her endless and helpful assignment. Thank you all-the participants, the speakers, the conference chair, the sponsors-for making this conference a success and we are looking forward to the next occasion in this series of meetings which will be celebrated in Uppsala.

  15. Renewable energy development and prospects in Australia

    International Nuclear Information System (INIS)

    Ahmad Zahedi

    2000-01-01

    Development of renewable energies in Australia is still in its infancy and will require active support by government, utilities and financing institutions to ensure a steady growth. Much has been done to increase the utilisation of renewable energies in the energy supply, but much still remains to be done, especially in the areas of promotion, demonstration, training and technology transfer. This process will lead to meeting the energy needs of the population in rural areas and to contributing to a suitable development of the region during the next century. Australia is endowed with a wealth of renewable energy resources that hold great promise for addressing a host of important environmental, employment and socioeconomic issues. Australia has a set of climate, geographic and other factors that provide favourable conditions for many specific renewable energy applications. The objectives of this paper is to look at the current situation of renewable energies in Australia, opportunities, constraints, current projects, available potential and future prospects. (Author)

  16. Laser ignited engines: progress, challenges and prospects.

    Science.gov (United States)

    Dearden, Geoff; Shenton, Tom

    2013-11-04

    Laser ignition (LI) has been shown to offer many potential benefits compared to spark ignition (SI) for improving the performance of internal combustion (IC) engines. This paper outlines progress made in recent research on laser ignited IC engines, discusses the potential advantages and control opportunities and considers the challenges faced and prospects for its future implementation. An experimental research effort has been underway at the University of Liverpool (UoL) to extend the stratified speed/load operating region of the gasoline direct injection (GDI) engine through LI research, for which an overview of some of the approaches, testing and results to date are presented. These indicate how LI can be used to improve control of the engine for: leaner operation, reductions in emissions, lower idle speed and improved combustion stability.

  17. Universal doomsday: analyzing our prospects for survival

    Energy Technology Data Exchange (ETDEWEB)

    Gerig, Austin [CABDyN Complexity Centre, Saïd Business School, University of Oxford, Oxford OX1 1HP (United Kingdom); Olum, Ken D.; Vilenkin, Alexander, E-mail: austin.gerig@sbs.ox.ac.uk, E-mail: kdo@cosmos.phy.tufts.edu, E-mail: vilenkin@cosmos.phy.tufts.edu [Institute of Cosmology, Department of Physics and Astronomy, Tufts University, Medford MA 02155 (United States)

    2013-05-01

    Given a sufficiently large universe, numerous civilizations almost surely exist. Some of these civilizations will be short-lived and die out relatively early in their development, i.e., before having the chance to spread to other planets. Others will be long-lived, potentially colonizing their galaxy and becoming enormous in size. What fraction of civilizations in the universe are long-lived? The ''universal doomsday'' argument states that long-lived civilizations must be rare because if they were not, we should find ourselves living in one. Furthermore, because long-lived civilizations are rare, our civilization's prospects for long-term survival are poor. Here, we develop the formalism required for universal doomsday calculations and show that while the argument has some force, our future is not as gloomy as the traditional doomsday argument would suggest, at least when the number of early existential threats is small.

  18. Banking Sector of Ukraine: Realities, Tendencies, Prospects

    Directory of Open Access Journals (Sweden)

    Doroshenko Hanna O.

    2014-01-01

    Full Text Available The article analyses the modern state of the banking sector of Ukraine, its sources and prospects. It identifies that the main obstacle for stable development is dissociation of banking segments, absence of functional unity and orientation at formation of optimal conditions for satisfaction of financial requirements of the domestic economy. In order to create the efficient banking system it is necessary to introduce new banking supervision standards oriented at specialisation of the banking activity. The banking market should be segmented and both major banks that form the nucleus of the segment and minor ones operating in their niches should co-operate within each segment. Universal banks that have a developed branch network should unite specialised segments. Moreover, it is necessary to introduce changes into the mechanism of application of some instruments of money and loan regulation with respect to specialised banks and introduce some restrictions upon spheres of activity of the foreign capital.

  19. Prospects for Precision Neutrino Cross Section Measurements

    Energy Technology Data Exchange (ETDEWEB)

    Harris, Deborah A. [Fermilab

    2016-01-28

    The need for precision cross section measurements is more urgent now than ever before, given the central role neutrino oscillation measurements play in the field of particle physics. The definition of precision is something worth considering, however. In order to build the best model for an oscillation experiment, cross section measurements should span a broad range of energies, neutrino interaction channels, and target nuclei. Precision might better be defined not in the final uncertainty associated with any one measurement but rather with the breadth of measurements that are available to constrain models. Current experience shows that models are better constrained by 10 measurements across different processes and energies with 10% uncertainties than by one measurement of one process on one nucleus with a 1% uncertainty. This article describes the current status of and future prospects for the field of precision cross section measurements considering the metric of how many processes, energies, and nuclei have been studied.

  20. Energy in developing countries: prospects and problems

    International Nuclear Information System (INIS)

    Baum, V.

    1977-01-01

    This paper analyses requirements for primary energy and electric power in the developing countries in the light of projections of population and economic growth. It evaluates the availability of indigenous energy resources and focuses on input requirements (capital, technology, trained personnel) for accelerated energy development; it reviews possible supplies for such inputs from domestic sources, transnational corporations, multilateral institutions, and through co-operation among the developing countries themselves and between the developing and the developed countries. The paper analyses the findings of the United Nations study ''The Future of the World Economy. A Study on the Impact of the Prospective Economic Issues and Policies on the International Development Strategy'' as far as they relate to energy and the developing countries in the light of the objectives of the Declaration on the Establishment of a New International Economic Order

  1. Introducing the new meat. Problems and prospects

    Directory of Open Access Journals (Sweden)

    Stellan Welin

    2013-05-01

    Full Text Available Cultured meat, or in vitro meat, is one of the ideas that are being proposed to help solve the problems associated with the ever-growing global meat consumption. The prospect may bring benefit for the environment, climate, and animal ethics, but has also generated doubts and criticism. A discussion of the possible environmental benefit and of animal ethics issues in relation to cultured meat production will be given. A perceived 'unnaturalness' of cultured meat may be one of the strongest barriers for public acceptance. This will be discussed and rejected. As to our relations with nature and animals, it is plausible that cultured meat will lead to improvement rather than to deterioration. The issue of public acceptance and some of the problems of introducing this new product on the market will also be discussed.http://dx.doi.org/10.5324/eip.v7i1.1788

  2. Higgs searches and prospects at CDF

    International Nuclear Information System (INIS)

    Pavel A Murat

    2003-01-01

    The Standard model of electroweak interactions (SM) has been extremely successful in describing interactions of elementary particles over the last decades. The Higgs scalar boson is one of the key elements of the SM: Higgs interactions with the other particles generate the particle masses and allow to keep the theory renormalizable at electroweak scale. All the particles predicted by the SM but the Higgs boson have already been observed experimentally and therefore search for the Higgs is one of the most important scientific goals for high energy physics. The current lower limit on the SM Higgs mass M H > 114.4 GeV at 95% CL has been established by LEP experiments. In this paper we review CDF Run I results on Higgs searches including the Higgs bosons predicted by the minimal supersymmetric extention of the Standard Model (MSSM) and discuss the Run II prospects

  3. Detection prospects of the cosmic neutrino background

    Science.gov (United States)

    Li, Yu-Feng

    2015-04-01

    The existence of the cosmic neutrino background (CνB) is a fundamental prediction of the standard Big Bang cosmology. Although current cosmological probes provide indirect observational evidence, the direct detection of the CνB in a laboratory experiment is a great challenge to the present experimental techniques. We discuss the future prospects for the direct detection of the CνB, with the emphasis on the method of captures on beta-decaying nuclei and the PTOLEMY project. Other possibilities using the electron-capture (EC) decaying nuclei, the annihilation of extremely high-energy cosmic neutrinos (EHECνs) at the Z-resonance, and the atomic de-excitation method are also discussed in this review (talk given at the International Conference on Massive Neutrinos, Singapore, 9-13 February 2015).

  4. Innovation and design approaches within prospective ergonomics.

    Science.gov (United States)

    Liem, André; Brangier, Eric

    2012-01-01

    In this conceptual article the topic of "Prospective Ergonomics" will be discussed within the context of innovation, design thinking and design processes & methods. Design thinking is essentially a human-centred innovation process that emphasises observation, collaboration, interpretation, visualisation of ideas, rapid concept prototyping and concurrent business analysis, which ultimately influences innovation and business strategy. The objective of this project is to develop a roadmap for innovation, involving consumers, designers and business people in an integrative process, which can be applied to product, service and business design. A theoretical structure comprising of Innovation perspectives (1), Worldviews supported by rationalist-historicist and empirical-idealistic dimensions (2) and Models of "design" reasoning (3) precedes the development and classification of existing methods as well as the introduction of new ones.

  5. Heavy ion fusion: Prospects and status

    International Nuclear Information System (INIS)

    Herrmannsfeldt, W.B.

    1995-01-01

    Key events in the Heavy Ion Fusion (HIF) field are usually marked by the dates for the International Symposium series which began in 1976 at the Claremont Hotel, and most recently in the eleventh meeting in the series at the Princeton Plasma Physics Laboratory in September 1995. The main purpose of this talk will be to review the status of HIF as it was presented at Princeton, and also to try to deduce something about the prospects for HIF in particular, and fusion in general, from the world and US political scene. The status of the field is largely, though not entirely, expressed through presentations from the two leading HIF efforts: (1) The US program is primarily concerned with applying induction linac technology for HIF drivers; (2) The European program, centered at GSI, Darmstadt, but including several other laboratories, is primarily directed towards the rf linac approach using storage rings for energy compression

  6. Magnetic mirror fusion: status and prospects

    International Nuclear Information System (INIS)

    Post, R.F.

    1980-01-01

    Two improved mirror systems, the tandem mirror (TM) and the field-reversed mirror (FRM) are being intensively studied. The twin practical aims of these studies: to improve the economic prospects for mirror fusion power plants and to reduce the size and/or complexity of such plants relative to earlier approaches to magnetic fusion. While at the present time the program emphasis is still strongly oriented toward answering scientific questions, the emphasis is shifting as the data accumulates and as larger facilities - ones with a heavy technological and engineering orientation - are being prepared. The experimental and theoretical progress that led to the new look in mirror fusion research is briefly reviewed, the new TM and the FRM ideas are outlined, and the projected future course of mirror fusion research is discussed

  7. Nuclear power: Status report and future prospects

    International Nuclear Information System (INIS)

    Budnitz, Robert J.

    2016-01-01

    This article reviews the current status and future prospects of commercial nuclear electric power, with emphasis on issues of safety, physical security, proliferation, and economics. Discussions of these issues are presented separately for the current operating fleet, for new reactor designs similar in size to the current fleet, and for prospective new reactors of substantially smaller size. This article also discusses the issue of expansion of commercial nuclear power into new countries. The article concludes with recommendations, related both to technical issues and policy considerations. The major implications for policy are that although the level of safety and security achieved in today's operating reactor fleet worldwide is considered broadly acceptable, some advanced designs now under development potentially offer demonstrably safer performance, and may offer improved financial performance also. Management and safety culture are vital attributes for achieving adequate safety and security, as are a strong political culture that includes an absence of corruption, an independent regulatory authority, and a separation of nuclear operation from day-to-day politics. In some countries that are now considering a nuclear-power program for the first time, careful attention to these attributes will be essential for success. - Highlights: •Current status of nuclear reactor safety and security is judged to be adequate. •Strong management and safety culture are vital to achieve adequate nuclear safety. •Advanced reactor designs offer important safety advantages. •Maintaining and strengthening international nuclear institutions is important. •Achieving nuclear safety in “newcomer” countries requires a strong political culture.

  8. Prospection for natural 231Pa in India

    International Nuclear Information System (INIS)

    Anupama, P.; Gantayet, L.M.; Verma, R.; Parthasarathy, R.; Anil Kumar, S.; Dingankar, M.V.; Ghosh, S.K.; Patra, R.N.

    2001-08-01

    Protactinium-231 ( 231 Pa) occurs in nature as a member of the decay chain of naturally occuring 235 U of the 4n+ 3 radioactive series. The expected protactinium concentration in the Jaduguda ore body (with uranium concentration of 0.03-0.06 %) is around 0.2 parts per billion (ppb) and that in monazite ore (uranium concentration 0.3%) is 0.9 ppb. The process at uranium ore processing plant at Jaduguda was studied. 231 Pa content in samples from the process streams of the plant was determined. The gamma ray spectrometry method was chosen and standardised in our laboratory to detect and measure 231 Pa in parts per billion levels in these samples. A concentrated source of protactinium could not be found among the assessed streams of Jaduguda uranium plant. The Monazite processing plant at IRE, Aluva was then studied. From the known chemistry of protactinium, the possible distribution of the 231 Pa was guessed at. Accordingly, the process streams of IRE process plant were selected to prospect for 231 Pa and determine the fractionation of protactinium. For analysis of 231 Pa, the thorium bearing samples were chemically treated to remove the thorium daughter products, which interfere in gamma spectrometry. This report describes the planning for prospecting, sample selection, the standardisation of the analysis procedure for determination of 231 Pa content, and the analysis results. The 231 Pa content in various streams of Indian Rare Earths plant was found in the range 0.2 -6.5 ppb. Some of the streams did not carry any protactinium. The fractionation of 231 Pa in the various streams of the plant and the selection of source for recovery of protactinium are discussed in detail. (author)

  9. Shale gas exploitation: Status, problems and prospect

    Directory of Open Access Journals (Sweden)

    Shiqian Wang

    2018-02-01

    Full Text Available Over the past five years, great progress has been made in shale gas exploitation, which has become the most driving force for global gas output growth. Hydrocarbon extraction from shale helps drive the USA on the road to energy independence. Besides, shale oil & gas production has been kept in a sustained growth by continuous improvement in drilling efficiency and well productivity in the case of tumbling oil prices and rig counts. Shale gas reserves and production have been in a rapid growth in China owing to the Lower Paleozoic Wufeng and Longmaxi shale gas exploitation in the Sichuan Basin, which has become an important sector for the future increment of gas reserves and output in China. However, substantial progress has been made neither in non-marine shale gas exploitation as previously expected nor in the broad complicated tectonic areas in South China for which a considerable investment was made. Analysis of the basic situation and issues in domestic shale gas development shows that shale gas exploitation prospects are constrained by many problems in terms of resources endowment, horizontal well fracturing technology, etc. especially in non-marine shale deposits and complicated tectonic areas in South China where hot shales are widely distributed but geological structures are found severely deformed and over matured. Discussion on the prospects shows that the sustained and steady growth in shale gas reserves and production capacity in the coming years lies in the discovery and supersession of new shale plays in addition to Wufeng and Longmaxi shale plays, and that a technological breakthrough in ultra-high-pressure and ultra-deep (over 3500 m buried in the Sichuan Basin marine shale gas exploitation is the key and hope. Keywords: Shale gas, Exploitation, Marine facies, Hot shale, Resource endowment, Sichuan Basin, South China, Complicated tectonic area, Gas play

  10. MARICULTURE DEVELOPMENT IN INDONESIA: Prospects and Constraints

    Directory of Open Access Journals (Sweden)

    Michael A. Rimmer

    2010-12-01

    Full Text Available Mariculture is an important component of Indonesian fisheries and aquaculture production, directly contributing an estimated US$ 320 million in 2008. Because most mariculture production is focussed on producing for export markets, mariculture production is an important source of foreign earnings for the Indonesian economy. This paper reviews the current status and prospects for continuing development of mariculture in Indonesia. Currently the major mariculture commodity in Indonesia is seaweed for carrageenan production. Seaweed production accounts for 98% of total Indonesian mariculture production and 84% of value. The other major commodity groups are marine finfish and pearl oysters. Commodities being developed for mariculture in Indonesia include abalone and spiny lobsters. Prospects for continued development of mariculture in Indonesia appear positive. Indonesia has several advantages for mariculture development, including many potential mariculture sites, a stable tropical climate, and does not suffer from cyclonic storms. The Government of Indonesia is planning to increase aquaculture production substantially over the next four years, including mariculture production. Globally, demand for seafood products is expanding due to increasing population and increased per capita consumption of fish products. Constraints to the continued development of mariculture in Indonesia include: limited seed supply, particularly of species which cannot be economically produced in hatcheries, such as spiny lobsters; need to develop more efficient production systems for some marine finfish; the need to improve environmental sustainability by improving feeds and reducing environmental impacts; and market issues relating to environmental sustainability.

  11. Dual source multidetector CT-angiography before transcatheter aortic valve implantation (TAVI) using a high-pitch spiral acquisition mode

    Energy Technology Data Exchange (ETDEWEB)

    Wuest, W.; Anders, K.; May, M.S.; Uder, M. [University of Erlangen, Department of Radiology, Erlangen (Germany); Schuhbaeck, A.; Gauss, S.; Marwan, M.; Arnold, M.; Muschiol, G.; Daniel, W.G.; Achenbach, S. [University of Erlangen, Department of Cardiology, Erlangen (Germany); Ensminger, S. [University of Erlangen, Department of Cardiac Surgery, Erlangen (Germany)

    2012-01-15

    Transcatheter Aortic Valve Implantation (TAVI) is an alternative to surgical valve replacement in high risk patients. Angiography of the aortic root, aorta and iliac arteries is required to select suitable candidates, but contrast agents can be harmful due to impaired renal function. We evaluated ECG-triggered high-pitch spiral dual source Computed Tomography (CT) with minimized volume of contrast agent to assess aortic root anatomy and vascular access. 42 patients (82 {+-} 6 years) scheduled for TAVI underwent dual source (DS) CT angiography (CTA) of the aorta using a prospectively ECG-triggered high-pitch spiral mode (pitch = 3.4) with 40 mL iodinated contrast agent. We analyzed aortic root/iliac dimensions, attenuation, contrast to noise ratio (CNR), image noise and radiation exposure. Aortic root/iliac dimensions and distance of coronary ostia from the annulus could be determined in all cases. Mean aortic and iliac artery attenuation was 320 {+-} 70 HU and 340 {+-} 77 HU. Aortic/iliac CNR was 21.7 {+-} 6.8 HU and 14.5 {+-} 5.4 HU using 100 kV (18.8 {+-} 4.1 HU and 8.7 {+-} 2.6 HU using 120 kV). Mean effective dose was 4.5 {+-} 1.2 mSv. High-pitch spiral DSCTA can be used to assess the entire aorta and iliac arteries in TAVI candidates with a low volume of contrast agent while preserving diagnostic image quality. (orig.)

  12. Prospective analysis. Nuclear deterrence in 2030; Essai de prospective. La dissuasion nucleaire en 2030

    Energy Technology Data Exchange (ETDEWEB)

    Tertrais, B

    2006-12-15

    This study is a prospective analysis of the long-term future of nuclear weapons, and particularly the future of French nuclear deterrence after 2015. The selected time period is 2025-2030. The principal objective is to reflect on what the nuclear world might look like during the first part of the 21 st century, beyond the modernization decisions already planned or envisaged, and to draw conclusions for the future of the French deterrent. (author)

  13. The technological prospective of non nuclear channels; La prospective technologique des filieres non nucleaires

    Energy Technology Data Exchange (ETDEWEB)

    Claverie, M.; Clement, D.; Girard, C

    2000-07-15

    This prospective study concerns the electric power demand in 2050. It examines the three non nuclear sectors of production: the natural gas combined cycle power plants, the wind turbines among the renewable energies and the cogeneration electric power - heat in the ternary and building sector. The necessity of the network adaptation to the european competition and the decentralized production of electric power will suppose new investments of transport and storage. (A.L.B.)

  14. Prospective SAH Study in Japan, 2005(Prospective SAH Study)

    OpenAIRE

    塩川, 芳昭; 栗田, 浩樹; 藤井, 清孝; Yoshiaki, SHIOKAWA; Hiroki, KURITA; Kiyotaka, FUJII; 杏林大学脳神経外科; 杏林大学脳神経外科; 北里大学脳神経外科; Department of Neurosurgery, Kyorin University School of Medicine; Department of Neurosurgery, Kyorin University School of Medicine

    2009-01-01

    To clarify current treatment status of ruptured cerebral aneurysms in Japan, a prospective multicenter observational study on the treatment results for aneurysmal subarachnoid hemorrhage was conducted over calendar year 2005 and final 1-year outcomes were collected. Studied centers were selected from among institutes of committee member of Japanese stroke surgery organization or symposium of vasospasm in Japan. A total of 927 patients were enrolled in this study and treatment policies were le...

  15. Analyzing Perceptions of Prospective Teachers about Their Media Literacy Competencies

    Science.gov (United States)

    Recepoglu, Ergun; Ergun, Muammer

    2013-01-01

    The purpose of this study is to analyze perceptions of prospective teachers about their media literacy competencies in terms of different variables. This is a descriptive research in the survey model which tries to detect the current situation. Study group includes 580 prospective teachers from Turkish, Primary School, Social Studies, Science,…

  16. Skill Levels of Prospective Physics Teachers on Problem Posing

    Science.gov (United States)

    Cildir, Sema; Sezen, Nazan

    2011-01-01

    Problem posing is one of the topics which the educators thoroughly accentuate. Problem posing skill is defined as an introvert activity of a student's learning. In this study, skill levels of prospective physics teachers on problem posing were determined and their views on problem posing were evaluated. To this end, prospective teachers were given…

  17. Preparing Elementary Prospective Teachers to Teach Early Algebra

    Science.gov (United States)

    Hohensee, Charles

    2017-01-01

    Researchers have argued that integrating early algebra into elementary grades will better prepare students for algebra. However, currently little research exists to guide teacher preparation programs on how to prepare prospective elementary teachers to teach early algebra. This study examines the insights and challenges that prospective teachers…

  18. A Study on Chocolate Consumption in Prospective Teachers

    Science.gov (United States)

    Ozgen, Leyla

    2016-01-01

    This study was planned and conducted to determine the chocolate consumption habits of prospective teachers. The study population was comprised of students attending the Faculty of Education at Gazi University in Ankara and the sample consisted of 251 prospective teachers selected with simple random sampling. 96.4% and 3.6% of the prospective…

  19. Support vector machine: a tool for mapping mineral prospectivity

    NARCIS (Netherlands)

    Zuo, R.; Carranza, E.J.M

    2011-01-01

    In this contribution, we describe an application of support vector machine (SVM), a supervised learning algorithm, to mineral prospectivity mapping. The free R package e1071 is used to construct a SVM with sigmoid kernel function to map prospectivity for Au deposits in western Meguma Terrain of Nova

  20. Do Prospective Teachers Have Anxieties about Teaching Mathematics?

    Science.gov (United States)

    Yavuz, Günes

    2018-01-01

    The purpose of this study is to analyse the level of prospective classroom and mathematics teachers' anxieties about teaching mathematics. Freshman and junior prospective teachers from educational faculties of two different universities participated in this study. "Anxieties About Teaching Mathematics Scale" which was developed by Peker…

  1. Polyp prevalence at colonoscopy among Nigerians: A prospective ...

    African Journals Online (AJOL)

    Polyp prevalence at colonoscopy among Nigerians: A prospective observational study. ... Materials and Methods: This is a prospective study of all colonoscopy examinations performed at the endoscopy unit of our hospital from January, 2007 to December 2013. The patient demographics, indications for colonoscopy, ...

  2. Prospective Physics Teachers' Awareness of Radiation and Radioactivity

    Science.gov (United States)

    Tasoglu, Aslihan Kartal; Ates, Özlem; Bakaç, Mustafa

    2015-01-01

    The purpose of this study is to investigate prospective physics teachers' knowledge of and attitude towards radiation and radioactivity. Participants of this study are 56 prospective physics teachers. A questionnaire related with the knowledge about radiation and radiation fear was conducted. The results of this study showed that most of the…

  3. Prospective Pre-School Teachers' Attitudes towards Astronomy

    Science.gov (United States)

    Türk, Cumhur; Demir, Esra

    2016-01-01

    The purpose of this study is to examine the changes in prospective pre-school teachers' attitudes towards astronomy in terms of their grades. The study was conducted with 205 prospective teachers (1st, 2nd, 3rd, 4th graders) studying in the education faculty of a university in Eastern Anatolia region of Turkey. Astronomy Attitude Scale (AAS) was…

  4. Prospective Teachers' Views about Video-Enhanced General Biology Instruction

    Science.gov (United States)

    Çetin, Gülcan

    2014-01-01

    The aim of the study is to determine the views of the prospective physics and chemistry teachers about the video-enhanced General Biology instruction. The participants included 19 second-year prospective teachers (10 in Physics and 9 in Chemistry Education) at Necatibey Faculty of Education, Balikesir University, Turkey in the 2011-2012 academic…

  5. Premarital HIV Testing on Prospective Couples in A Teaching ...

    African Journals Online (AJOL)

    Premarital HIV Testing on Prospective Couples in A Teaching Hospital in Sub Saharan Africa. ... Background: Most religious bodies insist on premarital screening for prospective couples. Aim: To determine the level of voluntary screening, prevalence and risk factors of HIV among premarital couples. Material and methods: ...

  6. Examining the Image of Prospective Teachers towards Mathematicians

    Science.gov (United States)

    Yazlik, Derya Ozlem; Erdogan, Ahmet

    2018-01-01

    The aim of this study is to identify how prospective teachers see mathematicians by the pictures they visualized. In accordance with this purpose phenomenology pattern which is one of the qualitative patterns was used. The study was carried out with 160 volunteered prospective teachers. The data collection tool to be used in this study consists of…

  7. Improving the effectiveness of geological prospecting with neutron activation analysis

    International Nuclear Information System (INIS)

    Fardy, J.J.

    1984-01-01

    Two examples of the use of neutron activation analysis to improve the effectiveness of geological prospecting are examined. The first is application to the direct hydrogeochemical prospecting for gold in surface waters. The second shows how multielement data banks produced by NAA for a geological formation provide a powerful method for the classification of ore bodies and sedimentary materials

  8. Prospective Memory in Context: Moving through a Familiar Space

    Science.gov (United States)

    Smith, Rebekah E.; Hunt, R. Reed; Murray, Amy E.

    2017-01-01

    Successful completion of delayed intentions is a common but important aspect of daily behavior. Such behavior requires not only memory for the intended action but also recognition of the opportunity to perform that action, known collectively as prospective memory. The fact that prospective memory tasks occur in the midst of other activities is…

  9. 37 CFR 10.33 - Direct contact with prospective clients.

    Science.gov (United States)

    2010-07-01

    ... 37 Patents, Trademarks, and Copyrights 1 2010-07-01 2010-07-01 false Direct contact with prospective clients. 10.33 Section 10.33 Patents, Trademarks, and Copyrights UNITED STATES PATENT AND... clients. A practitioner may not solicit professional employment from a prospective client with whom the...

  10. Prospective Secondary Mathematics Teachers' Perspectives and Mathematical Knowledge for Teaching

    Science.gov (United States)

    Karagöz-Akar, Gülseren

    2016-01-01

    This study investigated the relationship between prospective secondary mathematics teachers' perspectives and their mathematical knowledge for teaching in action. Data from two prospective teachers' practice-teachings, one in geometry and one in algebra, their lesson plans and self-reflections were analyzed with Teacher Perspectives and Knowledge…

  11. An Axiomatization of Cumulative Prospect Theory for Decision under Risk

    NARCIS (Netherlands)

    Wakker, P.P.; Chateauneuf, A.

    1999-01-01

    Cumulative prospect theory was introduced by Tversky and Kahneman so as to combine the empirical realism of their original prospect theory with the theoretical advantages of Quiggin's rank-dependent utility. Preference axiomatizations were provided in several papers. All those axiomatizations,

  12. Prospective Science Teachers' Subject-Matter Knowledge about Overflow Container

    Science.gov (United States)

    Ültay, Eser

    2016-01-01

    The purpose of this study was to determine prospective science teachers' subject-matter knowledge (SMK) about overflow container. This study was carried out in the form of a case study in spring term of the academic year of 2013-2014 with seven sophomore prospective science teachers who were studying at Elementary Science Teaching Department in…

  13. Prospective memory: effects of divided attention on spontaneous retrieval.

    Science.gov (United States)

    Harrison, Tyler L; Mullet, Hillary G; Whiffen, Katie N; Ousterhout, Hunter; Einstein, Gilles O

    2014-02-01

    We examined the effects of divided attention on the spontaneous retrieval of a prospective memory intention. Participants performed an ongoing lexical decision task with an embedded prospective memory demand, and also performed a divided-attention task during some segments of lexical decision trials. In all experiments, monitoring was highly discouraged, and we observed no evidence that participants engaged monitoring processes. In Experiment 1, performing a moderately demanding divided-attention task (a digit detection task) did not affect prospective memory performance. In Experiment 2, performing a more challenging divided-attention task (random number generation) impaired prospective memory. Experiment 3 showed that this impairment was eliminated when the prospective memory cue was perceptually salient. Taken together, the results indicate that spontaneous retrieval is not automatic and that challenging divided-attention tasks interfere with spontaneous retrieval and not with the execution of a retrieved intention.

  14. The contribution of retrospective memory, attention and executive functions to the prospective and retrospective components of prospective memory following TBI.

    LENUS (Irish Health Repository)

    Clune-Ryberg, Melanie

    2011-01-01

    Despite the prevalence of prospective memory (PM) problems, relatively little is known about the processes underlying impairment following TBI. This study sought to examine PM performance, using a multiple-task, multiple-response video-based paradigm in which initial encoding of the cue-action associations was ensured (Video-Assessment of Prospective Memory; VAPM).

  15. Prospective mental imagery in patients with major depressive disorder or anxiety disorders

    NARCIS (Netherlands)

    Morina, N.; Deeprose, C.; Pusowski, C.; Schmid, M.; Holmes, E.A.

    2011-01-01

    Prospective negative cognitions are suggested to play an important role in maintaining anxiety disorders and major depressive disorder (MDD). However, little is known about positive prospective mental imagery. This study investigated differences in prospective mental imagery among 27 patients with

  16. Heavy ion fusion: Prospects and status

    International Nuclear Information System (INIS)

    Herrmannsfeldt, W.B.

    1995-10-01

    The main purpose of this talk is to review the status of HIF as it was presented at Princeton, and also to try to deduce something about the prospects for HIF in particular, and fusion in general, from the world and US political scene. The status of the field is largely, though not entirely, expressed through presentations from the two leading HIF efforts: (1) the US program, centered at LBNL and LLNL, is primarily concerned with applying induction linac technology for HIF drivers; (2) the European program, centered at GSI, Darmstadt, but including several other laboratories, is primarily directed towards the rf linac approach using storage rings for energy compression. Several developments in the field of HIF should be noted: (1) progress towards construction of the National Ignition Facility (NIF) gives strength to the whole rational for developing a driver for Inertial Fusion Energy; (2) the field of accelerator science has matured far beyond the status that it had in 1976; (3) Heavy Ion Fusion has passed some more reviews, including one by the Fusion Energy Advisory Committee (FEAC), and has received the usual good marks; (5) as the budgets for Magnetic Fusion have fallen, the pressures on the Office of Fusion energy (OFE) have intensified, and a move is underway to shift the HIF program out of the IFE program and back into the ICF program in the Defense Programs (DP) side of the DOE

  17. Prospective memory, personality, and individual differences.

    Science.gov (United States)

    Uttl, Bob; White, Carmela A; Wong Gonzalez, Daniela; McDouall, Joanna; Leonard, Carrie A

    2013-01-01

    A number of studies investigating the relationship between personality and prospective memory (ProM) have appeared during the last decade. However, a review of these studies reveals little consistency in their findings and conclusions. To clarify the relationship between ProM and personality, we conducted two studies: a meta-analysis of prior research investigating the relationships between ProM and personality, and a study with 378 participants examining the relationships between ProM, personality, verbal intelligence, and retrospective memory. Our review of prior research revealed great variability in the measures used to assess ProM, and in the methodological quality of prior research; these two factors may partially explain inconsistent findings in the literature. Overall, the meta-analysis revealed very weak correlations (rs ranging from 0.09 to 0.10) between ProM and three of the Big Five factors: Openness, Conscientiousness, and Agreeableness. Our experimental study showed that ProM performance was related to individual differences such as verbal intelligence as well as to personality factors and that the relationship between ProM and personality factors depends on the ProM subdomain. In combination, the two studies suggest that ProM performance is relatively weakly related to personality factors and more strongly related to individual differences in cognitive factors.

  18. PROSPECTS OF CURCUMIN USE IN NANOBIOTECHNOLOGY

    Directory of Open Access Journals (Sweden)

    M. I. Kaniuk

    2016-06-01

    Full Text Available The aim of the work was a generalization of literature data on the prospects for curcumin usage in biotechnology as a component for biologically active nanocomplexes with anti-inflammatory and antioxidant activity creation. It is emphasized that their effectiveness depends on the solubility in aqueous medium and on the metabolism rate decreasing in the body. Current trend is the development of creation methods of hydrophilic curcumin-based nanostructures to increase the time of its biological action. Its nanostructures with silicium, polylysine, copolymers of lactic and glycolic acids and metal ions are the most promising in this respect. For multicomponent hybrid nanoparticles effective usage the substantiation of their component combined use features is necessary. The practical task is to create and to study the functional properties of such combined nanocomplexes. Curcumin complex with metal ions creation contributes to its water solubility and to increase the efficiency of biological action. These complexes have specific characteristics depending on the nature of metal ion. The creation of curcumin-based biocompatible nanocomposites with amplifiers of its action that are known pharmaceuticals is perspective. Such multifunctional nanocomplexes will facilitate the targeted medicines delivery to the places of pathological processes localization and the reduction of their side effects.

  19. Pediatric neurocysticercosis: current challenges and future prospects

    Directory of Open Access Journals (Sweden)

    Singhi P

    2016-03-01

    Full Text Available Pratibha Singhi, Arushi Gahlot SainiDepartment of Pediatrics, Pediatric Neurology and Neurodevelopment Unit, Advanced Pediatrics Centre, Post Graduate Institute of Medical Education and Research, Chandigarh, IndiaAbstract: Neurocysticercosis (NCC is an acquired infection of the nervous system caused by encysted larvae of Taenia solium. It is a major cause of epilepsy in the tropics and the commonest cause of focal seizures in North Indian children. T. solium teniasis-cysticercosis is considered a parasitic “Neglected Tropical Diseases” endemic throughout Southeast Asia. NCC in children has pleomorphic manifestations depending on the location, number and viability of the cysts, and host response. Even with advancing knowledge of the disease manifestations, many aspects related to diagnosis and treatment, particularly in children, still remain controversial and pose challenges to clinical practice. There is no gold standard test to diagnose NCC and the management recommendations are still emerging. This review provides an overview of diagnosis of NCC in children and its management with special focus on current challenges and future prospects.Keywords: neurocysticercosis, children, epilepsy, ring enhancing lesions, pigs

  20. Radiopharmaceuticals in China. Current status and prospects

    Energy Technology Data Exchange (ETDEWEB)

    Jia, Hong-Mei; Liu, Bo-Li [Beijing Normal Univ. (China). Key Laboratory of Radiopharmaceuticals

    2014-04-01

    The review provides an overview of the current status of radiopharmaceuticals in China for in vivo clinical use and also describes some important advances in the past three decades. Development of the diagnostic and therapeutic radiopharmaceuticals as well as basic research on radiopharmaceutical chemistry are being introduced. The radiotracers developed in China include: (1) Brain perfusion imaging agents and CNS radiotracers for β-amyloid plaques, σ{sub 1} receptors, and dopamine D{sub 2} or D{sub 4} receptors; (2) {sup 99m}Tc- and {sup 18}F-labeled myocardial perfusion imaging agents; (3) tumor imaging agents including integrin-targeting radiotracer, novel sentinel lymph node imaging agents, hypoxia imaging agents, {sup 99m}Tc-labeled glucose derivatives, σ{sub 2} receptor imaging agents, folate receptor imaging agents, and potential radiotracers for imaging of human telomerase reverse transcriptase expression; (4) Potential infection imaging agents; (5) Potential asialoglycoprotein receptor imaging agents; (6) Other imaging agents. Moreover, some prospects of research and development of radiopharmaceuticals in the near future are discussed. (orig.)

  1. Livestock Environment Prospects for the 90's

    Directory of Open Access Journals (Sweden)

    W. W. Thatcher

    1996-01-01

    Full Text Available When projecting livestock environmental prospects for the 1990's. it is critical to recognize the multidimensional nature of managing livestock species under hot environments. This paper identifies potential critical physiological windows during the life cycle of the animal that are sensitive to heat stress and responsive to environmental modification. Ovarian follicular development appears to be sensitive to heat stress leading to reductions in intensity of oestrus and subsequent fertility. Periods of follicular development that are sensitive to heat stress have not been defined. With current improved systems to alter the microenvironment of animals. the period of embryonic sensitivity to heat stress has shifted so that early embryonic losses are less. Potential recombinant proteins that may enhance embryo survival and correct deficiencies in placental function that are induced by heat stress warrant additional investigation. The postpartum period is a critical period in which a multitude of factors interact to influence animal productivity and its sensitivity to heat stress. Nutritional strategies to improve animal performance with the use of fat-supplementation are discussed. Environmental modification and housing systems need to not only maximize the efficiency of animal production but need to consider the potential impact on the environment relative to water use. soil and water pollution. Animal production and management systems need to consider both animal health and well-being issues. To optimize profit under conditions of greater societal constraints and available management alternatives, computer assisted management systems will become a critical tool.

  2. Main prospects of EDF's nuclear program

    International Nuclear Information System (INIS)

    Pierre Bacher, M.; Jean Pierrard, M.

    1994-01-01

    Today, EDF is at a half way point in its third major standardized series, the N4 1400 MW series. The main objective agreed upon for this N4 series, was to improve the insertion of man in the control loop. After the TMI accident in 1979, selective improvements had already been introduced in the 900 series ; the 1300 series, which was the underway, was also the object of more significant improvements (for instance a digital control system) ; but it still seemed desirable that all the lessons to be learned from the accident be reflected in the third series : the fully computerized instrumentation and control system developed for the N4 series ?comparable to the one developed for Airbus ?is today the first of its kind in the world. The demand increase for electric energy dramatically stopped in 1993. However, the prospect for the coming years is more optimistic. Electricity consumption is expected to increase slowly by an average 2% per year. In this context, EDF is preparing its energy program for the nest century and takes into account that hydraulic generation capacity will remain stable and that the French thermal units fueled with coal are rather old and will have to be replaced.

  3. Moon. Prospective energy and material resources

    Energy Technology Data Exchange (ETDEWEB)

    Badescu, Viorel (ed.) [Polytechnic Univ. of Bucharest (Romania). Candida Oancea Inst.

    2012-07-01

    The Earth has limited material and energy resources. Further development of the humanity will require going beyond our planet for mining and use of extraterrestrial mineral resources and search of power sources. The exploitation of the natural resources of the Moon is a first natural step on this direction. Lunar materials may contribute to the betterment of conditions of people on Earth but they also may be used to establish permanent settlements on the Moon. This will allow developing new technologies, systems and flight operation techniques to continue space exploration. In fact, a new branch of human civilization could be established permanently on Moon in the next century. But, meantime, an inventory and proper social assessment of Moon's prospective energy and material resources is required. This book investigates the possibilities and limitations of various systems supplying manned bases on Moon with energy and other vital resources. The book collects together recent proposals and innovative options and solutions. It is a useful source of condensed information for specialists involved in current and impending Moon-related activities and a good starting point for young researchers. (orig.)

  4. Nuclear industry prospects: A Canadian perspective

    International Nuclear Information System (INIS)

    Morden, Reid

    1995-01-01

    Canada, with its proven, safe and versatile CANDU reactor is well poised for the second half-century of nuclear fission. Canada's nuclear pedigree goes back to the turn-of-the-century work of Ernest Rutherford in Montreal. This year, Canada's nuclear industry celebrates the 50th anniversary of the start-up of its first research reactor at Chalk River. Last year, the pioneering work of Bert ram Blockhouse in Physics was honoured with a Nobel Prize. Future international success for the nuclear industry, such as has been achieved here in Korea, depends on continued cooperative and collaborative team work between the public and private sectors, continued strong research and development backing by the government, and new strategic partnerships. The biggest challenge is financing for the emerging markets. The brightness or dimness of future prospects are relative to the intensity of the lessons learned from history. In Canada we have a fairly long nuclear pedigree, It goes back almost a century to 1898, when Ernest Rutherford set up a world centre at McGill University in Montreal for research into the structure of the atom and into radioactivity

  5. Prospective safety performance evaluation on construction sites.

    Science.gov (United States)

    Wu, Xianguo; Liu, Qian; Zhang, Limao; Skibniewski, Miroslaw J; Wang, Yanhong

    2015-05-01

    This paper presents a systematic Structural Equation Modeling (SEM) based approach for Prospective Safety Performance Evaluation (PSPE) on construction sites, with causal relationships and interactions between enablers and the goals of PSPE taken into account. According to a sample of 450 valid questionnaire surveys from 30 Chinese construction enterprises, a SEM model with 26 items included for PSPE in the context of Chinese construction industry is established and then verified through the goodness-of-fit test. Three typical types of construction enterprises, namely the state-owned enterprise, private enterprise and Sino-foreign joint venture, are selected as samples to measure the level of safety performance given the enterprise scale, ownership and business strategy are different. Results provide a full understanding of safety performance practice in the construction industry, and indicate that the level of overall safety performance situation on working sites is rated at least a level of III (Fair) or above. This phenomenon can be explained that the construction industry has gradually matured with the norms, and construction enterprises should improve the level of safety performance as not to be eliminated from the government-led construction industry. The differences existing in the safety performance practice regarding different construction enterprise categories are compared and analyzed according to evaluation results. This research provides insights into cause-effect relationships among safety performance factors and goals, which, in turn, can facilitate the improvement of high safety performance in the construction industry. Copyright © 2015 Elsevier Ltd. All rights reserved.

  6. Ukrainian-Chinese collaboration: Prospects of development

    Directory of Open Access Journals (Sweden)

    Kratt Oleh

    2017-01-01

    Full Text Available In article the current state of the Chinese-Ukrainian relations is analysed, the priority directions of strategic cooperation are considered. The analysis of economic development of Ukraine and China with definition of positive and negative tendencies is carried out. It is certain that there is a mutual aspiration of the parties before increase in volumes of bilateral trade, diversification of its structure, development of long-term forms of economic cooperation, deepening of investment interaction between Ukraine and China. The analysis of the study is conducted during 2010-2016 years. We have identified prospective investment sectors within the framework of cooperation between Ukraine and China - Transport Infrastructure, Agriculture, Renewable energy, Telecommunications, IT, educational sphere. The current dynamics of the trade balance between Ukraine and the People’s Republic of China, taking into account the considerable predominance of imports, requires a thorough review of trade policy measures: to improve the structure of trade, introducing new forms of trade relations, To develop the institutional framework for cooperation, To search for ways to reduce the energy intensity of export industries, To stimulate the means of tariff and non-tariff regulation of imports into Ukraine of mainly investment high-tech goods. The forecast of possible risks according to each perspective direction of development is made.

  7. Hybrid Perovskites: Prospects for Concentrator Solar Cells.

    Science.gov (United States)

    Lin, Qianqian; Wang, Zhiping; Snaith, Henry J; Johnston, Michael B; Herz, Laura M

    2018-04-01

    Perovskite solar cells have shown a meteoric rise of power conversion efficiency and a steady pace of improvements in their stability of operation. Such rapid progress has triggered research into approaches that can boost efficiencies beyond the Shockley-Queisser limit stipulated for a single-junction cell under normal solar illumination conditions. The tandem solar cell architecture is one concept here that has recently been successfully implemented. However, the approach of solar concentration has not been sufficiently explored so far for perovskite photovoltaics, despite its frequent use in the area of inorganic semiconductor solar cells. Here, the prospects of hybrid perovskites are assessed for use in concentrator solar cells. Solar cell performance parameters are theoretically predicted as a function of solar concentration levels, based on representative assumptions of charge-carrier recombination and extraction rates in the device. It is demonstrated that perovskite solar cells can fundamentally exhibit appreciably higher energy-conversion efficiencies under solar concentration, where they are able to exceed the Shockley-Queisser limit and exhibit strongly elevated open-circuit voltages. It is therefore concluded that sufficient material and device stability under increased illumination levels will be the only significant challenge to perovskite concentrator solar cell applications.

  8. Bruxism in craniocervical dystonia: a prospective study.

    Science.gov (United States)

    Borie, Laetitia; Langbour, Nicolas; Guehl, Dominique; Burbaud, Pierre; Ella, Bruno

    2016-09-01

    Bruxism pathophysiology remains unclear, and its occurrence has been poorly investigated in movement disorders. The aim of this study was to compare the frequency of bruxism in patients with craniocervical dystonia vs. normal controls and to determine its associated clinical features. This is a prospective-control study. A total of 114 dystonic subjects (45 facial dystonia, 69 cervical dystonia) and 182 controls were included. Bruxism was diagnosed using a hetero-questionnaire and a clinical examination performed by trained dentists. Occurrence of bruxism was compared between the different study populations. A binomial logistic regression analysis was used to determine which clinical features influenced bruxism occurrence in each population. The frequency of bruxism was significantly higher in the dystonic group than in normal controls but there was no difference between facial and cervical dystonia. It was also higher in women than in men. Bruxism features were similar between normal controls and dystonic patients except for a higher score of temporomandibular jaw pain in the dystonic group. The higher frequency of bruxism in dystonic patients suggests that bruxism is increased in patients with basal ganglia dysfunction but that its nature does not differ from that seen in bruxers from the normal population.

  9. Implications and Prospects of the GNEP

    International Nuclear Information System (INIS)

    Ryu, Jae-Soo; Lee, Byung-Wook; Lee, Han-Myung; Ko, Han-Suk; Lee, Kwang-Seok; Kim, Hak-Ro

    2008-01-01

    As increased recognition for a role of an economical carbon-free nuclear energy, it is expected that possibility for introduction and an expansion of nuclear power plants (NPPs) will be increased around the world,1) with pursuing self-reliant nuclear fuel cycle in certain states to secure assurances of nuclear fuel supply. However, the pursuit of sensitive nuclear technology such as enrichment and reprocessing has led to concerns about nuclear proliferation. The disclosure of nuclear black market has threatened the current global nonproliferation regime.2) To respond to these concerns, efforts have been made to overcome the loophole of the existing nuclear nonproliferation regime. In February 2004, US President Bush proposed that nuclear exporters refuse to transfer sensitive nuclear technology to prevent new states from producing fissile material to close a loophole in the NPT.3) Meanwhile as the amount of spent nuclear fuel (SNF) by once-through fuel cycle increases, the US needs multiple repositories by the end of the century.4) In February 2006, therefore, Bush administration announced the Global Nuclear Energy Partnership (GNEP), which can bring about expansion of nuclear energy including SNF management while decreasing the risk of nuclear proliferation. It is expected that the GNEP will have an effect on national nuclear programs of participating countries as well as nuclear international cooperation. In this regard, this paper discusses the implication of the GNEP and its prospects

  10. Prospects of Nuclear Power for Developing Countries

    International Nuclear Information System (INIS)

    Mourogov, V. M.; Khan, A. M.; Rogner, H-H.; Kagramanian, V. S.

    1998-01-01

    The demand for electricity in developing countries of the world is expected to grow rapidly in the coming decades as these countries undergo the process of industrialization, accompanied by increased urbanization, and seek to improve the living standards of their growing population. The continued heavy reliance of the power sector on fossil fuels will result in an increased dependence of a number of the developing countries on energy imports, with consequentbalance of payment difficulties and implications in terms of reduced energy security, cause severe degradation of the local and regional environment, and will also lead to increasing emissions of greenhouse gases. Increasing the share of hydropower in most of the developing countries is constrained by the limited potential of hydro resources as well as environmental considerations. Other renewable energy technologies such as solar PV and wind power are not expected to play a significant role in the commercial supply of electricity in the foreseeable future in the most part of the developing world. Thus nuclear power as a non-fossil alternative with a proven and mature technology may be called upon to play an increasing role in the future supply of electricity to developing countries. The paper discusses the main factors that are likely to affect, both positively and negatively, the deployment of nuclear power in developing countries and presents the results of the recent IAEA projections on nuclear power capacity growth up to the 2020. The paper also briefly reviews the prospects of nuclear power in Central and Eastern European countries. (author)

  11. Prospects for nuclear power international after Fukushima

    International Nuclear Information System (INIS)

    Kidd, Steve

    2012-01-01

    Full-text: The Fukushima accident in March 2011 has imposed a number of significant challenges for the world nuclear industry, in terms of enhancing safety at both existing and prospective reactor sites and in regaining public trust for its operations. Yet despite setbacks in a number of countries (notably Germany in addition to Japan itself) the overall outlook for nuclear power around the world is little changed from before the accident. The front end of the nuclear fuel cycle is fully internationalised and operates as a series of competitive markets, guaranteeing economic supply to the operating reactors around the world. Although new reactor types with potentially different fuelling modes are on the horizon, nothing much is likely to change before 2030. The back end is, however, comparatively less developed and there remain substantial uncertainties how it will develop in the future. Technical solutions exist, but governments have failed to grasp realities in used fuel management and waste disposal. Although many commentators argue that low levels of public acceptance are the prime reason for nuclear power failing to take a more substantial part of the energy mix, the root cause is relatively poor economics (at least in much of the Western world). Plants cost too much to build, essentially taking too long to complete, by comparison with rival generating technologies. Additionally, cheap natural gas has become a barrier in certain markets. The risk profile of nuclear projects therefore makes it difficult to attract financing but there are some possible solutions to these issues. (author)

  12. Prospect of nuclear application in food technology

    Energy Technology Data Exchange (ETDEWEB)

    Maha, M [National Atomic Energy Agency, Jakarta (Indonesia). Pasar Djumat Research Centre

    1982-04-01

    Irradiation changes the normal living process of cells and the structure of molecules. It is good for food preservation because it kills off many of the microorganisms in the product and makes the remainder more sensitive to antimicrobial factors prevailing after the radiation treatment. It offers more benefits than conventional preservation in that it increases storage stability and quality of foodstuffs with the minimum use of energy. Good storage quality gives way to wider distribution of food, alleviates the world's food shortage, and improves food supplies. Research proved that irradiation increased the quality of subtropical fruits, spices, fish, and meat. No refrigeration is needed to store meat, poultry and fish preserved by the combination of irradiation and mild heat treatment. Nuclear technology can also be applied to destroy harmful insects, to sterilize food, to inhibit the sprouting of root crops, and to control ripening in stored fruits and vegetables. Based on the above potentials of irradiation, the prospect of nuclear application in food technology is promising.

  13. Prospects of ceramic tritium breeder materials

    International Nuclear Information System (INIS)

    Roth, E.; Roux, N.; Conservatoire National des Arts et Metiers; CEA Centre d'Etudes Nucleaires de Saclay, 91 - Gif-sur-Yvette

    1989-01-01

    In this paper the authors examine the prospects of the main ceramics proposed as breeder materials for fusion reactors, i.e. Li-2O, Li-2ZrO-3, LiAlO-2, Li-4SiO-4. To do so they review terms of reference of contemplated blankets for NET, ITER and DEMO, and the proposed blanket concepts and materials. Issues respective to the use of each breeder material are examined, and from this review it is concluded that ceramics are the most favorable breeder materials whose use can be contemplated as well for a driver blanket for NET or ITER and for a DEMO blanket. Ceramics are then compared between themselves and it is seen that, subject to the confirmation of recent experimental results, lithium zirconate could be used with advantage in any of the present blanket concepts, except in those employing lithium at its natural isotopic abundance, in which case only Li-2O can be used. However in specific cases, or in parts of a blanket, other ceramics may be profitably employed. As a general conclusion suggestions are made to further improve ceramic breeder performances, and it is recommended to intensify also work on problems that have to be solved in order to operate ceramic breeder blankets e.g. tritium extraction and recovery systems and conditions of beryllium use. (author). 37 refs.; 12 tabs

  14. Prospects of Cooperation between Russia and Turkey

    Directory of Open Access Journals (Sweden)

    Elvin Aghayev

    2017-06-01

    Full Text Available Russian – Turkish relations go deep into the past. From the Cold War and the relations between the Soviet Union and the United States certainly there has not been a more complicated relationship in international relations. Both countries have different strategic positions, a different dominant religion, a different past, but their relationship largely depends on the future of Eurasia. This paper will deal with relations between the two countries since the establishment of the first diplomatic contacts in the 15th century, through the relationship during the time of Peter the Great, and will mention the periods of the First and Second World Wars, as well as the Cold War era. Special attention will be focused on the current relations between the two countries, especially after the conflict in 2015, when Turkey shot down a Russian plane over Syria. Special attention will be focused on energy policy and the potential for building a nuclear power plant in Mersin, and the continuation of Turkish stream. The paper will deal with economics and trade exchange, which have almost disappeared following the 2015 incident, security cooperation and Turkey’s plans to buy the defense system S-400 from Russia, as well as relations between the two countries towards NATO. The paper will end with the projection of the prospects for the economic relations between the two countries.

  15. Social Entrepreneurship in Ukraine: Problems and Prospects

    Directory of Open Access Journals (Sweden)

    Rodchenko Volodymyr B.

    2017-09-01

    Full Text Available The aim of the article is to identify the current trends in the development of social entrepreneurship in Ukraine as a new form of doing business in the context of socio-economic transformations. By analyzing and generalizing scientific works of many scientists, the evolution of the development of social enterprises is considered, the views of researchers on the definition of the concept of “social entrepreneurship” and its key factors are systematized. The modern tendencies, main barriers and opportunities for the development of social entrepreneurship in Ukraine are revealed. As a result of the research, differentiation of social enterprises according to the level of social and business activity is proposed. The experience of formation and development of social entrepreneurship in European countries is studied. It is substantiated that under the current conditions of transition from the resource-oriented paradigm of economic development to the value-oriented one, the motivational component of human labor changes: money loses the role of a key motivational factor; possibility of creating economic values for others by implementing own plans and initiatives comes to the fore. A prospect for further research in this area is studying regulatory and legal aspects of the emergence of social entrepreneurship in Ukraine as a driver of sustainable economic development of the country.

  16. Uterus transplantation: current progress and future prospects

    Directory of Open Access Journals (Sweden)

    Johannesson L

    2016-02-01

    Full Text Available Liza Johannesson, Stina Järvholm Department of Obstetrics and Gynecology, Sahlgrenska Academy, University of Gothenburg, Sahlgrenska University Hospital, Gothenburg, Sweden Abstract: Even if reproductive medicine has been remarkably successful during the past few decades, with the introduction of in vitro fertilization in the late 1970s and intracytoplasmic sperm injection in the early 1990s, it has been repeatedly mocked by infertility due to an absolute uterine factor. No treatment has been available for the women suffering from an absent or dysfunctional uterus, in terms of carrying a pregnancy. Approximately one in 500 women suffer from absolute uterine infertility, and the option so far to become a mother has been to either adopt or utilize gestational surrogacy. As of today, a total of eleven cases of human uterus transplantations have been reported worldwide, conducted in three different countries. The results of these initial experimental cases far exceed what might be expected of a novel surgical method. Many more uterus transplantations are to be expected in the near future, as other research teams’ preparations are being ready to be put into clinical practice. In this review, we summarize the current worldwide experience of uterus transplantation as a treatment of absolute uterine factor infertility and the future prospects of human uterus transplantation. Keywords: uterus, transplantation, infertility

  17. International nuclear markets: Problems and prospects

    International Nuclear Information System (INIS)

    Skjoeldebrand, R.

    1984-01-01

    International nuclear trade is now of considerable importance for the energy balances of a number of countries. From the start, it has been regulated by bilateral or multilateral agreements, ones that always included conditions to obtain non-proliferation assurances with verification requirements, now based on IAEA safeguards. Nuclear trade indeed would have been impossible without the non-proliferation regime that has been developed. Recently, non-proliferation objectives and conditions have come to dominate discussions about international nuclear trade through restrictions introduced in the 1970s as a result of developing national policies. The International Nuclear Fuel Cycle Evaluation (INFCE) 1977-1980, and most recently the Committee of Assurances of Supply (CAS) established by the IAEA Board of Governors in 1980, have studied these matters in detail. It sometimes seems, however, that other and possibly more fundamental problems and limitations are given secondary importance. This article discusses some of these factors as regards international trade in nuclear plants and the fuel cycle, and looks at some prospects for the future

  18. Nuclear proliferation: prospects, problems, and proposals

    International Nuclear Information System (INIS)

    Anon.

    1977-01-01

    This issue of the ANNALS addresses itself to three aspects of nuclear proliferation: the prospect that new nuclear powers will come on the scene, the problems that their arrival may create, and ways of coping with those problems. In an introductory paper, ''Quo Vadimus,'' Joseph I. Coffey investigates the pros and cons of proliferation, concluding that it is not a question of whether there will be nuclear proliferation, but in what countries. Part I, Where We Are, contains five papers preceded by introductory comments by Joseph I. Coffey. The papers and their authors are: Why States Go--and Don't Go--Nuclear, William Epstein; How States Can ''Go Nuclear,'' Frank C. Barnaby; What Happens If. . .Terrorists, Revolutionaries, and Nuclear Weapons, David Kreiger; Safeguards Against Diversion of Nuclear Material: An Overview, Ryukichi Imai; and Reducing the Incentives to Proliferation, George H. Quester. Part II, And Where We May Go, again includes some introductory remarks by Joseph I. Coffey. The seven succeeding papers are: Nth Powers of the Future, Ashok Kapur; Nuclear Proliferation and World Politics, Lewis A. Dunn; Arms Control in a Nuclear Armed World, Colin Gray; The United Nations, the Superpowers, and Proliferation, Abraham Bargman; Proliferation and the Future: Destruction or Transformation, Frederick C. Thayer; Decision Making in a Nuclear Armed World, Michael Brenner; and The United States in a World of Nuclear Powers, Michael Nacht. This special report is concluded with a glossary

  19. Petroleum products : part 1 - overview and prospects

    International Nuclear Information System (INIS)

    1996-01-01

    The petroleum products industry represents the downstream (refining and products marketing) portion of the oil industry. It includes companies that refine crude oil into petroleum products, transport them to distribution storage terminals and sell them directly to major users or wholesale and retail outlets. Issues regarding investment and financing, trade and export strategies, technological innovation and adaptation, human resources, the environment and sustainable development within the sector are discussed, illustrating, among other things, how government and industry can commit to mutually beneficial goals and actions. The petroleum industry is a major source of revenue for Canadian governments which collect about $9 billion annually in federal and provincial taxes on gasoline alone. The industry is capital-intensive and very competitive, with a strong domestic focus. Key points relevant to the sector are examined from the global, North American and Canadian perspectives, highlighting changing conditions and industry responses in both the refining and retailing segments of the sector. Growth prospects in terms of profitability and environmental issues were also analyzed. 11 figs

  20. Endogenous antispermatogenic agents: prospects for male contraception.

    Science.gov (United States)

    Ewing, L L; Robaire, B

    1978-01-01

    A review of endogenous antispermatogenic agents as prospects for male contraception is reported. It is demonstrated that endogenous compounds exert regulatory influences at 4 major levels in the male: 1) between germ cells; 2) between Sertoli and germ cells; 3) between Leydig cells and seminiferous tubules; and 4) between the central nervous system and the testis. Efforts to interrupt spermatogenesis have failed to find application as male contraceptives for various reasons: 1) some investigators ignored the vulnerable control points by utilizing nonspecific agents; 2) others attacked a vulnerable control point but used synthetic drugs that had deleterious side effects; and 3) still others attacked a vulnerable control point with a relatively innocuous drug but used an impractical mode of drug administration. The potential for devising innovative techniques for administering relatively innocuous drugs at dosages sufficient to produce sterility without causing deleterious side effects is demonstrated. The most promising solution for the development of an antispermatogenic male contraceptive is the interference with the adenohypophyseal-gonadal axis via the subcutaneous sustained release of steroid formulations containing either androgen-danazol, androgen-progestin, or androgen-estrogen formulations. Another promising agent would be luteinizing releasing hormone agonist-androgen formulation.

  1. Prospect of radioisotopes and radiation utilization

    International Nuclear Information System (INIS)

    Tabata, Yoneho

    1994-01-01

    Radiation Utilization in Japan has been positioned, together with nuclear power generation, as one of the important cornerstones, and research and development and practical usage of it has been proceeded with steadily in the fields of industry, agriculture, medicine, and so on. In the field of medicine, SPECT and PET facilities, radio-immunoassay, radiotherapy has come widely to practical use. In the field of agriculture and fisheries, improvement of breed, sterile insect technique have been implemented, and eradication of melon fly has been achieved. In the field of industry, it is expected that the practical use of neutron radiography technique and research and development of synthesizing high performance, high function materials are progressed. In the environment preservation area, a pilot test using electron beam to treat the exhaust gases out of coal fired power plants, city garbages combustion facilities, city high way tunnels in order to establish de- sulphur/de-nitrogen technique is carried out. As the international contribution in the field of radiation utilization, the cooperation with developing countries and the cooperation among advanced countries are reported. In this paper, a prospect of radioisotopes and radiation utilization is described. (J.P.N.)

  2. Particle physics - Recent successes and future prospects

    International Nuclear Information System (INIS)

    Wojcicki, S.

    1985-01-01

    The situation in particle physics today is highly analogous to that which existed in chemistry towards the end of the 19th century. During the preceding two centuries, remarkable progress has been achieved in that discipline, progress that culminated in the periodic table of Mendeleyev. This paper summarized not only the realization that the everyday matter is composed of basic building blocks, called elements, but also that these different elements had certain similarities which could be used to properly arrange them in the periodic table. Thus the inert gases (helium, neon, argon, etc.) had very similar chemical properties, namely chemical inertness; the halogens (chlorine, iodine, florine) on the other hand were highly reactive. Other similarities were seen among the rare earth group of elements, alkaline earths, and alkali metals. In this paper the author attempts to summarize briefly the historical background that led us to the present level of understanding, or more specifically to the ''standard model'' of particle physics. He also describes several difficulties with this picture, continues with some possible indications of new physics, and finally end with the discussion of the prospects for the future

  3. Ossiculoplasty: A Prospective Study of 80 Cases

    Directory of Open Access Journals (Sweden)

    Shrinivas Shripatrao Chavan

    2014-07-01

    Full Text Available Introduction: The use of ossicular graft material in ossicular chain reconstruction has significantly improved hearing results hearing after tympanoplasty and tympanomastoid surgery for chronic otitis media. Today, otologists have a wide array of tools from which to choose, but may find it difficult to know which middle ear implant works best.   Materials and Methods: A prospective study of 80 patients who underwent ossiculoplasty was performed in the ear, nose, and throat (ENT department at a tertiary health care facility from 2011 to 2013. Patients with chronic suppurative otitis media with an air-bone gap (ABG of >25 dB with ossicular involvement were included in the study. Total ossicular replacement prosthesis (TORP, partial ossicular replacement prosthesis (PORP, and refashioned incus were used. Success was defined as ABG   Results: The majority patients were of middle age with moderate conductive hearing loss. Incus was the most susceptible ossicle. Overall success rate in this study was 80.0% with an average change of 15.76 dB in ABG.   Conclusion:  With continuing advances in our understanding of middle ear mechanics, the results of ossiculoplasty are improving and results can be very rewarding in experienced hands. Severity of preoperative ear discharge, preoperative mastoid cellularity, presence of disease, and surgical procedure proved to be significant prognostic factors. Autograft incus and PORP fared better when the malleus handle was present while TORP gave better results when the malleus handle was eroded.  

  4. Physics prospects with the upgraded ATLAS detector

    CERN Document Server

    Rizatdinova, Flera; The ATLAS collaboration

    2015-01-01

    Run-I at the LHC has been very successful, including the discovery of a new particle with a mass of about 125 GeV and with properties compatible with those of the Standard Model Higgs boson within uncertainties. Precise measurements of the properties of this boson, and the discovery of new physics beyond the Standard Model, are primary goals of future running at the LHC. The physics prospects based on 300/fb and 3000/fb protonproton collision data to be collected at 14 TeV are presented. The ultimate precision attainable on measurements of the couplings of the 125 GeV particle to elementary fermions and bosons is discussed, as well as perspectives on the searches for partners associated with this new object, predicted by several extensions of the standard theory. Supersymmetry is one of the best motivated and well-studied extensions of the Standard Model. The current searches at the LHC have yielded sensitivity to TeV scale gluinos and 1st and 2nd generation squarks, as well as to 3rd generation squarks and e...

  5. Physics prospects with the upgraded ATLAS detector

    CERN Document Server

    Volpi, Guido; The ATLAS collaboration

    2015-01-01

    Run-I at the LHC has been very successful, including the discovery of a new particle with a mass of about 125 GeV and with properties compatible with those of the Standard Model Higgs boson within uncertainties. Precise measurements of the properties of this boson, and the discovery of new physics beyond the Standard Model, are primary goals of future running at the LHC. The physics prospects based on 300/fb and 3000/fb proton-proton collision data to be collected at 14 TeV are presented. The ultimate precision attainable on measurements of the couplings of the 125 GeV particle to elementary fermions and bosons is discussed, as well as perspectives on the searches for partners associated with this new object, predicted by several extensions of the standard theory. Supersymmetry is one of the best motivated and well-studied extensions of the Standard Model. The current searches at the LHC have yielded sensitivity to TeV scale gluinos and 1st and 2nd generation squarks, as well as to 3rd generation squarks and ...

  6. Uranium geology and prospecting in Greenland

    International Nuclear Information System (INIS)

    Steenfelt, A.; Neilson, B.L.; Secher, K.

    1977-01-01

    The Geological Survey of Greenland is responsible for most of the uranium and thorium prospecting activity in Greenland, which involves airborne gamma spectrometry and scintillometry, geochemical sampling, geological investigations and ground scintillometry. Since 1971 large areas of east and west Greenland have been investigated by aerial surveys, geochemical sampling and most of the detailed scintillometric work having been restricted to small areas in east Greenland. Anomalous radioactivity in west Greenland is recorded from carbonatite intrusions, and from units in Proterozoic and Archaean gneisses. No mineralization has been found to date. In south Greenland investigations have been centred on the uranium and thorium deposit at Kvanefjeld, which is situated in a corner of the Ilimaussaq alkaline intrusion. The coincidence of favourable conditions during the differentiation and crystallization of the magma led to an extreme enrichment of uranium and thorium in the rocks that were last formed - the lujavrites. The deposit comprises parts of the lujavrites and a secondary enrichment zone in the contact between lujavrite and basaltic cover rocks. Reasonably assured reserves are 5800 t U with a grade of 310 ppm U. In the Caledonides of east Greenland some gneisses in basement cores, a dark siltstone in late Precambrian sediments and the Devonian acid magmatic rocks are characterized by a higher radiation level. A number of small mineral occurrences have been found, the majority of which are associated with the Devonian acid magmatic rocks. (author)

  7. Forest biomass observation: current state and prospective

    Directory of Open Access Journals (Sweden)

    D. G. Schepaschenko

    2017-08-01

    Full Text Available With this article, we provide an overview of the methods, instruments and initiatives for forest biomass observation at global scale. We focus on the freely available information, provided by both remote and in-situ observations. The advantages and limitation of various space borne methods, including optical, radar (C, L and P band and LiDAR, as well as respective instruments available on the orbit (MODIS, Proba-V, Landsat, Sentinel-1, Sentinel-2 , ALOS PALSAR, Envisat ASAR or expecting (BIOMASS, GEDI, NISAR, SAOCOM-CS are discussed. We emphasize the role of in-situ methods in the development of a biomass models, providing calibration and validation of remote sensing data. We focus on freely available forest biomass maps, databases and empirical models. We describe the functionality of Biomass.Geo-Wiki.org portal, which provides access to a collection of global and regional biomass maps in full resolution with unified legend and units overplayed with high-resolution imagery. The Forest-Observation-System.net is announced as an international cooperation to establish a global in-situ forest biomass database to support earth observation and to encourage investment in relevant field-based observations and science. Prospects of unmanned aerial vehicles in the forest inventory are briefly discussed. The work was partly supported by ESA IFBN project (contract 4000114425/15/NL/FF/gp.

  8. The Prospects of Radical Change Today

    Directory of Open Access Journals (Sweden)

    Slavoj Žižek

    2018-05-01

    Full Text Available In this contribution, Slavoj Žižek takes the occasion of Marx’s bicentenary for reflecting on the prospects of radical change today. First, it is shown that under Stalinism, Lenin’s works were quoted out of context in an arbitrary way in order to legitimise arbitrary political measures. Marxism thereby became an ideology that justified brutal subjective interventions. Second, this contribution poses the question of the revolutionary subject and democracy today. It stresses the role of both contingency and strategy in revolutions. In political assemblages taking place on public squares, the inert mass of ordinary people is transubstantiated into a politically engaged united force. The basic political problem today is how to best reconfigure democracy. Third, this contribution analyses the “interesting times” we live in. These are times that feature multiple crises, right-wing populism à la Donald Trump and Marine Le Pen, the lower classes’ opposition to immigration, and the refugee crisis. Questions about human rights and their violation and about radical change need to be asked in this context.

  9. Iran's petrochemical industry : status and prospects

    International Nuclear Information System (INIS)

    Jazayeri, S.

    2006-01-01

    This presentation provided some basic information, current status and prospects for Iran's petrochemical industry with particular reference to Iran's National Petrochemical Company (NPC), one of the fastest growing chemical producers and exporters in the world. According to Chemical Marketing Associates Inc. (CMAI), NPC will become the second largest commodity chemical producer in the world by 2015, ranking only behind Dow Chemical. Product categories include chemicals and aromatics; fertilizers; polymers; feedstocks and gas. Opportunities for cooperation with North America were also identified. Iran's domestic markets were shown to be well developed downstream petrochemical industries producing a broad range of industrial and consumer goods. Iran's foreign markets include Asia (66 per cent), Middle East (25 per cent), and Europe (9 per cent). This presentation examined Iran's comparative advantage in the further development of its petrochemical/chemical industries. Some details of NPC's organizational structure were also provided, along with production, domestic sales, exports and ongoing expansion and development projects. Remarks on the projected and potential growth in NPC's position in the world markets were included with reference to potential for foreign participation and investment into the petrochemical industry in Iran. tabs., figs

  10. Depression after CABG: a prospective study

    Directory of Open Access Journals (Sweden)

    Joana Kátya Veras Rodrigues Sampaio Nunes

    2013-12-01

    Full Text Available INTRODUCTION: Depression during or shortly after hospitalization elevated two to three times the risk of mortality or nonfatal cardiac events, significantly increasing the morbidity and mortality of these patients. OBJECTIVE: To assess the impact of revascularization on symptoms of depression in patients with coronary artery disease. METHODS: A prospective cohort study of 57 patients of both sexes undergoing coronary artery bypass grafting between June 2010 and June 2011. We used the SF-36 to assess quality of life, and the Beck Depression Inventory to detect depressive symptoms, applied preoperatively and six months. RESULTS: The prevalence of patients aged 60-69 years was 22 patients (38.60%, 39 men (68.42%, 26 described themselves as mixed race (45.61%, 16 literate (28.07 % and 30 married (52.63%. The beck depression inventory score demonstrated increased after revascularization: 15 patients mild (26.32% at time zero to 17 (29.82% after. And with moderate, seven patients (12.28% before and 10 (17.54% after. In the categories of individuals with decreased minimum degree of 32 (56.14% to 28 (49.12%, and severe of three (5.26% for two (3.51% patients. Association was observed between beck depression inventory, gender, age, lifestyle, comorbidities and quality of life. CONCLUSION: There was a high prevalence of elevated beck depression inventory scores, lowest scores of depressive symptoms among men and association between the improvement of quality of life scores and beck depression inventory.

  11. Prospects for ethanol production from whey

    Energy Technology Data Exchange (ETDEWEB)

    Marshall, K R

    1978-05-01

    Whey is a by-product of the manufacture of cheese and casein. Casein whey is not as fully utilized as cheese whey although in the last five years commercial processes have been developed to recover the whey proteins, either in denatured form as lactalbumin or in their soluble form as Solac. The removal of the whey proteins makes little difference to the polluting strength or volume of the whey and a crude lactose solution - serum or permeate - remains to be processed. Many processes have been evaluated for the use of this crude lactose solution; one is microbial transformation to produce products such as methane, ethanol, acetone and butanol and etc. The technologies for these processes are well known and it is the economic evaluation which ultimately determines the feasibility of the process being considered. For the purposes of this paper, the prospects for ethanol production have been evaluated. Unless there is a significant reduction in capital costs, it is concluded that ethanol production from whey is not a viable proposition as an energy source for New Zealand. Industrial ethanol (annual imports; 3.5 x 10/sup 6/ 1 CIF value 32 c/1) and potable ethanol production may be worth contemplating.

  12. Employment Change and Business Prospects in Serbia

    Directory of Open Access Journals (Sweden)

    Kosovka Đ Ognjenovic

    2013-11-01

    Full Text Available The aim of this article is to examine whether some previous knowledge about business prospects affects companies’ decisions about new employment in Serbia. In order to investigate this assumption a set of firm level data for 2012 is used. Following the theoretical approach that put an employer in a position to make various decisions about employment within the company, the trichotomous logit model is employed for the estimation of outcomes of possible companies’ decisions with respect to a set of independent variables. We find that the level of employment in the year that precedes companies’ decisions and relative changes in the number of employees in two successive years, as well as age and size of the company to some extent, affect companies’ decisions about new employment. The most important finding of our research is that the companies that experienced fluctuations in the number of employees and upgraded their business opportunities in the previous period hesitate to make decisions on the engagement of new workers, whereas those companies that lost some business opportunities rather decide to downsize the total number of employees.

  13. Prospect of coal liquefaction in Indonesia

    International Nuclear Information System (INIS)

    Hartiniati; Dasuki, A.S.; Artanto, Yu.; Sulaksono, D.; Gunanjar

    1997-01-01

    With the current known oil reserves of about 11 billion barrel and annual production of approximately 500 million barrel, the country's oil reserves will be depleted by 2010, and Indonesia would have become net oil importer if no major oil fields be found somewhere in the archipelago. Under such circumstances the development of new sources of liquid fuel becomes a must, and coal liquefaction can be one possible solution for the future energy problem in Indonesia, particularly in the transportation sector due to the availability of coal in huge amount. This paper present the prospect of coal liquefaction in Indonesia and look at the possibility of integrating the process with HTR as a heat supplier. Evaluation of liquidability of several low grade Indonesian coals will also be presented. Coal from South Banko-Tanjung Enim is found to be one of the most suitable coal for liquefaction. Several studies show that an advanced coal liquefaction technology recently developed has the potential to reduce not only the environmental impact but also the production cost. The price of oil produced in the year 2000 is expected to reach US $ 17.5 ∼ 19.2/barrel and this will compete with the current oil price. Not much conclusion can be drawn from the idea of integrating HTR with coal liquefaction plant due to limited information available. (author). 7 figs, 3 tabs

  14. Injuries in competitive boxing. A prospective study.

    Science.gov (United States)

    Siewe, J; Rudat, J; Zarghooni, K; Sobottke, R; Eysel, P; Herren, C; Knöll, P; Illgner, U; Michael, J

    2015-03-01

    Boxing remains a subject of controversy and is often classified as dangerous. But the discussion is based mostly on retrospective studies. This survey was conducted as a prospective study. From October 2012 to September 2013, 44 competitive boxers were asked to report their injuries once a month. The questionnaire collected general information (training, competition) and recorded the number of bouts fought, injuries and resulting lost days. A total of 192 injuries were recorded, 133 of which resulted in interruption of training or competition. Each boxer sustained 3 injuries per year on average. The injury rate was 12.8 injuries per 1 000 h of training. Boxers fighting more than 3 bouts per year sustain more injuries (p=0.0075). The injury rate does is not a function of age (age≤19 vs. > 19a, p=0.53). Injuries to the head and the upper limbs occur most frequently. The most common injuries are soft tissue lacerations and contusions. Head injuries with neurological symptoms rarely occur (4.2%). Boxing has a high injury rate that is comparable with other contact sports, but most injuries are minor. Injury frequency is not a function of whether the boxer competes in the junior or adult category. Athletes fighting many bouts per year have a greater risk of injury. © Georg Thieme Verlag KG Stuttgart · New York.

  15. Content knowledge of prospective elementary school teacher for fractional concepts

    Science.gov (United States)

    Pattimukay, N.; Juniati, D.; Budiarto, M. T.

    2018-03-01

    The aim of this study was to describe the content knowledge especially the concept of fraction of prospective elementary school teacher. The purpose of this study is to describe the content knowledge, especially the concept of fraction of prospective elementary school teacher. The subject of the study was one of prospective elementary school teacher of Pattimura University. This research is qualitative research. Data were collected through the provision of tests to explore the knowledge content of primary school teacher candidates about fractional concepts. Then continued with qualitative data analysis. The results of this study are as follows: that the prospective primary school teacher defines fractions as part of the whole if an object is divided into equal parts, so that the part that has been divided is part of the whole. Furthermore, the prospective elementary school teacher understood the fractions as division shown in two ways, namely the prospective elementary school teacher understood the fraction as a division operation, the primary school teacher candidate interpreted the fraction as a division when an object is divided be part of the same. Meanwhile, the fraction as a ratio is interpreted as the relationship between a pair of numbers. Then, the denominations are interpreted as a ratio between the numerator and the denominator of the same value. The prospective elementary school teacher also understands fractions of value when simplifying fractions. Primary school teacher candidates understand the concept of fractional operations.

  16. Prospecting for coal in China with remote sensing

    Energy Technology Data Exchange (ETDEWEB)

    Ke-long Tan; Yu-qing Wan; Sun-xin Sun; Gui-bao Bao; Jing-shui Kuang [Aerophotogrammetry and Remote Sensing Center of China Coal, Xi' an (China)

    2008-12-15

    In China it is important to explore coal prospecting by taking advantage of modern remote sensing and geographic information system technologies. Given a theoretical basis for coal prospecting by remote sensing, the methodologies and existing problems are demonstrated systematically by summarizing past practices of coal prospecting with remote sensing. A new theory of coal prospecting with remote sensing is proposed. In uncovered areas, coal resources can be prospected by direct interpretation. In coal bearing strata of developed areas covered by thin Quaternary strata or vegetation, prospecting for coal can be carried out by indirect interpretation of geomorphology and vegetation. For deeply buried underground deposits, coal prospecting can rely on tectonic structures, interpretation and analysis of new tectonic clues and regularity of coal formation and preservation controlled by tectonic structures. By applying newly hyper-spectral, multi-polarization, multi-angle, multi-temporal and multi-resolution remote sensing data and carrying out integrated analysis of geographic attributes, ground attributes, geophysical exploration results, geochemical exploration results, geological drilling results and remote sensing data by GIS tools, coal geology resources and mineralogical regularities can be explored and coal resource information can be acquired with some confidence. 12 refs., 4 figs., 3 tabs.

  17. Inventory of uranium prospect area Rantau Prapat North Sumatra: general prospection stage

    International Nuclear Information System (INIS)

    Wusana, Y.; Djalil, A.; Sriyono; Sutriyono, A.; Sajiyo

    2000-01-01

    The research has been carried out to gain knowledge of geology, radiometry, geochemistry to bound U prospect area scale 1:50.000. Based on investigation result of preliminary prospection was obtained indication of uranium mineralization as stream sediment anomalies in meta sandstone (Perm-Carboniferous) 0.86-28.00 ppm, sandstone (Middle-Upper Miosen) 1.192-7.20 ppm, granite (Upper Permian) 10.71-12.00 ppm; The total U content in sandstone until 10.29 ppm, granite 33.24 ppm, and radiometry of stand stone 25-150 cps, granite 200-500 cps. Lithology of the prospect area consist of quartzite, phyllitte, sandstone, siltstone, clay stone, conglomerate, granite, quartz feldspatic veins, andesite, tufaceous. Strike slip fault, normal fault, foliation and folding has been obtained in these area. Uranium anomalies of stream sediments were found in Conglomerate-Stand stone (1.04-4.80) ppm, Quartzite-Phyllite (0.91-1.90) ppm and Granite units (9.81-13.20) ppm. Uranium content of Conglomerate-stand stone (2.5-5) ppm, quartzite-phyllite (3.0-46.0) ppm, tuffaceous (9.0-22.0) ppm and granite (biotite muscovite) (23.5-40.0) ppm. Granite in these area is as uranium source. Based on anomaly of stream sediments on Conglomerate-Stand stone unit only about 7.64 km 2 , Quartzite-Phyllite 12.04 km 2 , Granite 10.20 km 2 and no supported by heavy mineral anomalies, radiometry and U rock content, so it was advised to not investigate follow up. (author)

  18. Carbon and prospective: international colloquium jointly organized by the prospective modeling chair and ETSAP

    International Nuclear Information System (INIS)

    Maizi, N.; Hourcade, J.Ch.; Selosse, S.

    2009-01-01

    The inauguration of the prospective modeling chair in favour of sustainable development is the result of the joint effort of several schools, organizations and companies, in particular: Mines ParisTech, Ponts ParisTech, Agro ParisTech, the higher education and research pole of ParisTech, the Ecole des Ponts foundation, the mineral, mining and metallurgic industries foundation (FI3M), with the partnership of Ademe, EdF, Renault, Schneider Electric and Total. The main goal of this chair is to perpetuate modeling tools with sustainable development stakes. The scientific program and the expertise of this chair are based on the joint and complementary experience of its two co-founder research teams in the domain of long-term prospective of energy, economy and environment-related questions: the applied mathematics centre (CMA - Mines ParisTech) and the international centre of environment and sustainable development research (CIRED). An inaugural colloquium was organized at the occasion of the launching of this chair. During round tables, representatives of the different intervening parties explained the stakes of this huge project and their expectations, in particular from the scientific, economical and societal point of view. A workshop on the topic 'carbon and prospective' followed the round tables. Six presentations were given about the following topics: energy policy scenarios for 2050 (Moncomble, J.E.), the shadow price of carbon (Chambolle T.), mitigation targets and carbon values: insights from TIMES-FR (Assoumou E.), climate protection and infrastructures (Sassi O.), China's energy and carbon options (Wenying C.), EU 20-20 policy implications on the energy system of Germany - an analysis with TIMES PanEU (Blesl M.). This book gathers the proceedings of both parts of this colloquium, the debates during the round tables (in French) and the presentations given during the workshop (in English). (J.S.)

  19. Computing risk for oil prospects: principles and programs

    International Nuclear Information System (INIS)

    Harbaugh, J.W.; Davis, J.C.; Wendebourg, J.

    1995-01-01

    This volume in the series Computer Methods in the Geosciences examines the challenge of risk assessment, field size distributions, and success, sequence and gambler's ruin. The estimation of the discovery size from the prospect size, outcome probabilities and success ratios, modeling prospects, and mapping properties and uncertainties are reviewed, and discriminating discoveries and dry holes, forecasting cash flow for a prospect, the worth of money, and use of risk analysis tables, decision tables and trees are considered. Appendices cover the installation of the RISK program and user manuals, and two disks are included with the volume. (UK)

  20. Loads and loads and loads: the influence of prospective load, retrospective load, and ongoing task load in prospective memory

    Science.gov (United States)

    Meier, Beat; Zimmermann, Thomas D.

    2015-01-01

    In prospective memory tasks different kinds of load can occur. Adding a prospective memory task can impose a load on ongoing task performance. Adding ongoing task load (OTL) can affect prospective memory performance. The existence of multiple target events increases prospective load (PL) and adding complexity to the to-be-remembered action increases retrospective load (RL). In two experiments, we systematically examined the effects of these different types of load on prospective memory performance. Results showed an effect of PL on costs in the ongoing task for categorical targets (Experiment 2), but not for specific targets (Experiment 1). RL and OTL both affected remembering the retrospective component of the prospective memory task. We suggest that PL can enhance costs in the ongoing task due to additional monitoring requirements. RL and OTL seem to impact the division of resources between the ongoing task and retrieval of the retrospective component, which may affect disengagement from the ongoing task. In general, the results demonstrate that the different types of load affect prospective memory differentially. PMID:26082709