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Sample records for angiography quantitative assessment

  1. Coronary CT Angiography in the Quantitative Assessment of Coronary Plaques

    Directory of Open Access Journals (Sweden)

    Zhonghua Sun

    2014-01-01

    Full Text Available Coronary computed tomography angiography (CCTA has been recently evaluated for its ability to assess coronary plaque characteristics, including plaque composition. Identification of the relationship between plaque composition by CCTA and patient clinical presentations may provide insight into the pathophysiology of coronary artery plaque, thus assisting identification of vulnerable plaques which are associated with the development of acute coronary syndrome. CCTA-generated 3D visualizations allow evaluation of both coronary lesions and lumen changes, which are considered to enhance the diagnostic performance of CCTA. The purpose of this review is to discuss the recent developments that have occurred in the field of CCTA with regard to its diagnostic accuracy in the quantitative assessment of coronary plaques, with a focus on the characterization of plaque components and identification of vulnerable plaques.

  2. Diagnostic accuracy of stress perfusion CMR in comparison with quantitative coronary angiography: fully quantitative, semiquantitative, and qualitative assessment.

    Science.gov (United States)

    Mordini, Federico E; Haddad, Tariq; Hsu, Li-Yueh; Kellman, Peter; Lowrey, Tracy B; Aletras, Anthony H; Bandettini, W Patricia; Arai, Andrew E

    2014-01-01

    This study's primary objective was to determine the sensitivity, specificity, and accuracy of fully quantitative stress perfusion cardiac magnetic resonance (CMR) versus a reference standard of quantitative coronary angiography. We hypothesized that fully quantitative analysis of stress perfusion CMR would have high diagnostic accuracy for identifying significant coronary artery stenosis and exceed the accuracy of semiquantitative measures of perfusion and qualitative interpretation. Relatively few studies apply fully quantitative CMR perfusion measures to patients with coronary disease and comparisons to semiquantitative and qualitative methods are limited. Dual bolus dipyridamole stress perfusion CMR exams were performed in 67 patients with clinical indications for assessment of myocardial ischemia. Stress perfusion images alone were analyzed with a fully quantitative perfusion (QP) method and 3 semiquantitative methods including contrast enhancement ratio, upslope index, and upslope integral. Comprehensive exams (cine imaging, stress/rest perfusion, late gadolinium enhancement) were analyzed qualitatively with 2 methods including the Duke algorithm and standard clinical interpretation. A 70% or greater stenosis by quantitative coronary angiography was considered abnormal. The optimum diagnostic threshold for QP determined by receiver-operating characteristic curve occurred when endocardial flow decreased to qualitative methods: Duke algorithm: 70%; and clinical interpretation: 78% (p quantitative stress perfusion CMR has high diagnostic accuracy for detecting obstructive coronary artery disease. QP outperforms semiquantitative measures of perfusion and qualitative methods that incorporate a combination of cine, perfusion, and late gadolinium enhancement imaging. These findings suggest a potential clinical role for quantitative stress perfusion CMR. Copyright © 2014 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

  3. Videodensitometric quantitative angiography after coronary balloon angioplasty, compared to edge-detection quantitative angiography and intracoronary ultrasound imaging

    NARCIS (Netherlands)

    Peters, R. J.; Kok, W. E.; Pasterkamp, G.; von Birgelen, C.; Prins, M. [=Martin H.; Serruys, P. W.

    2000-01-01

    AIMS: To assess the value of videodensitometric quantification of the coronary lumen after angioplasty by comparison to two other techniques of coronary artery lumen quantification. METHODS AND RESULTS: Videodensitometric quantitative angiography, edge detection quantitative angiography and 30 MHz

  4. Is quantitative coronary angiography reliable in assessing the lumen gain after treatment with the everolimus-eluting bioresorbable polylactide scaffold?

    NARCIS (Netherlands)

    Sotomi, Yohei; Onuma, Yoshinobu; Suwannasom, Pannipa; Tateishi, Hiroki; Tenekecioglu, Erhan; Zeng, Yaping; Cavalcante, Rafael; Jonker, Hans; Dijkstra, Jouke; Foin, Nicolas; Koon, Jaryl Ng Chen; Collet, Carlos; de Winter, Robbert J.; Wykrzykowska, Joanna J.; Stone, Gregg W.; Popma, Jeffrey J.; Kozuma, Ken; Tanabe, Kengo; Serruys, Patrick W.; Kimura, Takeshi

    2016-01-01

    The current study aimed to assess the difference in lumen dimension measurements between optical coherence tomography (OCT) and quantitative coronary angiography (QCA) in the polymeric bioresorbable scaffold and metallic stent. In the randomised ABSORB Japan trial, 87 lesions in the Absorb arm and

  5. Quantitative assessment technique of HyperEye medical system angiography for coronary artery bypass grafting.

    Science.gov (United States)

    Yamamoto, Masaki; Nishimori, Hideaki; Handa, Takemi; Fukutomi, Takashi; Kihara, Kazuki; Tashiro, Miwa; Sato, Takayuki; Orihashi, Kazumasa

    2017-02-01

    The HyperEye Medical System (HEMS) uses indocyanine green (ICG) to visualize blood vessels in coronary artery bypass grafting (CABG). We performed quantitative HEMS assessment to detect grafts at risk of occlusion. We assessed the HEMS angiograms of 177 grafts from 69 patients who underwent CABG and compared the results with those of fluoroscopic coronary angiography, by measuring the increasing rate of ICG intensity, average acceleration value, and time to peak luminance intensity. Grafts in the patent and failed groups showed significant differences in their increasing rate of intensity and average acceleration value. The average accelerations value of ICG intensity of internal thoracic artery (ITA) and saphenous vein (SV) grafts were 112.3 and 144.9 intensity/s 2 in the patent group, and 71.0 and 91.8 intensity/s 2 in the failed group. The time to peak luminance intensity was 1.7 and 1.4 s in the patent group and 2.3 and 1.9 s in the failed group; these values were not significantly different. Significant reductions in the ICG intensity rate and average acceleration value can occur in failed grafts. Therefore, quantifiable changes in ICG intensity may help detect minute changes in blood flow.

  6. Diagnostic Accuracy of Angiography-Based Quantitative Flow Ratio Measurements for Online Assessment of Coronary Stenosis.

    Science.gov (United States)

    Xu, Bo; Tu, Shengxian; Qiao, Shubin; Qu, Xinkai; Chen, Yundai; Yang, Junqing; Guo, Lijun; Sun, Zhongwei; Li, Zehang; Tian, Feng; Fang, Weiyi; Chen, Jiyan; Li, Wei; Guan, Changdong; Holm, Niels R; Wijns, William; Hu, Shengshou

    2017-12-26

    Quantitative flow ratio (QFR) is a novel angiography-based method for deriving fractional flow reserve (FFR) without pressure wire or induction of hyperemia. The accuracy of QFR when assessed online in the catheterization laboratory has not been adequately examined to date. The goal of this study was to assess the diagnostic performance of QFR for the diagnosis of hemodynamically significant coronary stenosis defined by FFR ≤0.80. This prospective, multicenter trial enrolled patients who had at least 1 lesion with a diameter stenosis of 30% to 90% and a reference diameter ≥2 mm according to visual estimation. QFR, quantitative coronary angiography (QCA), and wire-based FFR were assessed online in blinded fashion during coronary angiography and re-analyzed offline at an independent core laboratory. The primary endpoint was that QFR would improve the diagnostic accuracy of coronary angiography such that the lower boundary of the 2-sided 95% confidence interval (CI) of this estimate exceeded 75%. Between June and July 2017, a total of 308 patients were consecutively enrolled at 5 centers. Online QFR and FFR results were both obtained in 328 of 332 interrogated vessels. Patient- and vessel-level diagnostic accuracy of QFR was 92.4% (95% CI: 88.9% to 95.1%) and 92.7% (95% CI: 89.3% to 95.3%), respectively, both of which were significantly higher than the pre-specified target value (p difference: 32.0% [p difference: 36.1% [p Quantitative Flow Ratio in Online Assessment of Coronary Stenosis] II China study]; NCT03191708). Copyright © 2017 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

  7. Visual and Quantitative Assessment of Coronary Stenoses at Angiography Versus Fractional Flow Reserve: The Impact of Risk Factors.

    Science.gov (United States)

    Adjedj, Julien; Xaplanteris, Panagiotis; Toth, Gabor; Ferrara, Angela; Pellicano, Mariano; Ciccarelli, Giovanni; Floré, Vincent; Barbato, Emanuele; De Bruyne, Bernard

    2017-07-01

    The correlation between angiographic assessment of coronary stenoses and fractional flow reserve (FFR) is weak. Whether and how risk factors impact the diagnostic accuracy of angiography is unknown. We sought to evaluate the diagnostic accuracy of angiography by visual estimate and by quantitative coronary angiography when compared with FFR and evaluate the influence of risk factors (RF) on this accuracy. In 1382 coronary stenoses (1104 patients), percent diameter stenosis by visual estimation (DS VE ) and by quantitative coronary angiography (DS QCA ) was compared with FFR. Patients were divided into 4 subgroups, according to the presence of RFs, and the relationship between DS VE , DS QCA , and FFR was analyzed. Overall, DS VE was significantly higher than DS QCA ( P <0.0001); nonetheless, when examined by strata of DS, DS VE was significantly smaller than DS QCA in mild stenoses, although the reverse held true for severe stenoses. Compared with FFR, a large scatter was observed for both DS VE and DS QCA . When using a dichotomous FFR value of 0.80, C statistic was significantly higher for DS VE than for DS QCA (0.712 versus 0.640, respectively; P <0.001). C statistics for DS VE decreased progressively as RFs accumulated (0.776 for ≤1 RF, 0.750 for 2 RFs, 0.713 for 3 RFs and 0.627 for ≥4 RFs; P =0.0053). In addition, in diabetics, the relationship between FFR and angiographic indices was particularly weak (C statistics: 0.524 for DS VE and 0.511 for DS QCA ). Overall, DS VE has a better diagnostic accuracy than DS QCA to predict the functional significance of coronary stenosis. The predictive accuracy of angiography is moderate in patients with ≤1 RFs, but weakens as RFs accumulate, especially in diabetics. © 2017 American Heart Association, Inc.

  8. Quantitative angiography methods for bifurcation lesions

    DEFF Research Database (Denmark)

    Collet, Carlos; Onuma, Yoshinobu; Cavalcante, Rafael

    2017-01-01

    Bifurcation lesions represent one of the most challenging lesion subsets in interventional cardiology. The European Bifurcation Club (EBC) is an academic consortium whose goal has been to assess and recommend the appropriate strategies to manage bifurcation lesions. The quantitative coronary...... angiography (QCA) methods for the evaluation of bifurcation lesions have been subject to extensive research. Single-vessel QCA has been shown to be inaccurate for the assessment of bifurcation lesion dimensions. For this reason, dedicated bifurcation software has been developed and validated. These software...

  9. Data on the quantitative assessment pulmonary ground-glass opacification from coronary computed tomography angiography datasets

    DEFF Research Database (Denmark)

    Kühl, J Tobias; Kristensen, Thomas S; Thomsen, Anna F

    2017-01-01

    We assessed the CT attenuation density of the pulmonary tissue adjacent to the heart in patients with acute non-ST segment elevation myocardial infarction (J.T. Kuhl, T.S. Kristensen, A.F. Thomsen et al., 2016) [1]. This data was related to the level of ground-glass opacification evaluated by a r...

  10. Visual-Functional Mismatch Between Coronary Angiography, Fractional Flow Reserve, and Quantitative Coronary Angiography.

    Science.gov (United States)

    Safi, Morteza; Eslami, Vahid; Namazi, Mohammad Hasan; Vakili, Hossain; Saadat, Habib; Alipourparsa, Saeid; Adibi, Ali; Movahed, Mohammad Reza

    2016-12-01

    Anatomical and functional mismatches are not uncommon in the assessment of coronary lesions. The aim of this study was to identify clinical and lesion-specific factors affecting angiographic, anatomical, and functional mismatch in intermediate coronary lesions. In patients who underwent coronary angiography for clinical reasons, fractional flow reserve (FFR), and quantitative coronary angiography (QCA) analyses for intermediate stenotic lesions were performed simultaneously. Mismatches between the measured values were analyzed. A total of 95 intermediate lesions were assessed simultaneously by visual angiography, FFR, and QCA. The visual-FFR mismatch was found in 40% of the lesions while reverse visual-FFR mismatch was determined in nearly 14% of the lesions. Mismatch and reverse mismatch between FFR and QCA parameters were observed in 10 and 23% of the lesions. FFR value was significant in 32% of the lesions while visually significant stenosis was shown in 61% of the lesions. Among the visual-FFR reverse mismatch group, the prevalence of culprit lesions within the left anterior descending (LAD) was significantly higher than other vessels ( p value mismatches in analyses of intermediate coronary lesions. LAD lesions showed the highest mismatch. Angiographic or QCA estimation of lesion severity has consistently resulted in inappropriate stenting of functionally nonsignificant lesions or undertreatment of significant lesions based on FFR.

  11. Is quantitative coronary angiography reliable in assessing the late lumen loss of the everolimus-eluting bioresorbable polylactide scaffold in comparison with the cobalt-chromium metallic stent?

    NARCIS (Netherlands)

    Sotomi, Yohei; Onuma, Yoshinobu; Miyazaki, Yosuke; Asano, Taku; Katagiri, Yuki; Tenekecioglu, Erhan; Jonker, Hans; Dijkstra, Jouke; de Winter, Robbert J.; Wykrzykowska, Joanna J.; Stone, Gregg W.; Popma, Jeffrey J.; Kozuma, Ken; Tanabe, Kengo; Serruys, Patrick W.; Kimura, Takeshi

    2017-01-01

    Aims: Immediately after stent/scaffold implantation, quantitative coronary angiography (QCA) in comparison to optical coherence tomography (OCT) more severely underestimates the lumen diameter (LD) in Absorb than in XIENCE. This OCT-QCA discrepancy has not been evaluated at long-term follow-up. The

  12. Noninvasive quantitative assessment of cerebral blood flow (CBF) using Tc-99m ECD SPECT with adjunctive radionuclide angiography in ischemic stroke

    International Nuclear Information System (INIS)

    Yim, Jun Sung; Choi, Yun Young; Kim, Seung Hyun; Kim, Myung Ho; Cho, Suk Shin

    1999-01-01

    Quantitative CBF measurements are essential for diagnosing ischemic lesion, evaluating the therapeutic effects and predicting the prognosis of cerebral ischemia. Even though several methods have been introduced, these techniques are too cumbersome and invasive to be applied to routine studies. In this study, a non-invasive simple method for the quantitative angiography. Fifteen normal controls and 27 patients with unilateral carotid ischemic stoke were selected. Brain perfusion index (BPI) of each hemisphere was measured in each subject by acquisition of serial radionuclide angiography after injection of 20mCi of Tc-99m ECD. With Lassen's correction algorithm of curve-linear relationship between the brain activity and blood flow, rCBF on transaxial SPECT slice corresponding with MRI lesion sites (ischemic core, border zone and contralateral mirror locus) were calculated. BPI values for normal controls showed a significant negative correlation with advantage age (r=-0.64, p=0.021) and hemisphric BPI were 11.02±1.6 and 7.8±1.4 for normal controls and patient, respectively. Significant differences were observed between two groups (p=0.0012). rCBF obtained from core zone (12±2.5 ml/100/min), boneder zone (29.2±8.1) and contralateral mirror locus (52.1±15.1) were clearly defined in each subject of patient group. Measurement of BPI and rCBF using Tc-99m ECD SPECT with adjunctive radionuclide angiography could be an useful, simple and non-invasive method in evaluation of the cerebral flood in the ischemic stroke

  13. Optimization of Ecg Gating in Quantitative Femoral Angiography

    International Nuclear Information System (INIS)

    Nilsson, S.; Berglund, I.; Erikson, U.; Johansson, J.; Walldius, G.

    2003-01-01

    Purpose: To determine which phase of the heart cycle would yield the highest reproducibility in measuring atherosclerosis-related variables such as arterial lumen volume and edge roughness. Material and Methods: 35 patients with hypercholesterolemia underwent select ive femoral angiography, repeated four times at 10-min intervals. The angiographies were performed with Ecg-gated exposures. In angiographies 1 and 2 the delay from R-wave maximum to each exposure was 0.1 s, in angiographies 3 and 4 the delay was 0.1, 0.3, 0.5 or 0.7 s or the exposures were performed 1/s without Ecg gating. Arterial lumen volume and edge roughness were measured in a 20-cm segment of the superficial femoral artery using a computer-based densitometric method. Measurement reproducibility was determined by comparing angiographies 1-2 and angiographies 3-4. Results: When measuring arterial lumen volume and edge roughness of a 20-cm segment of the femoral artery, reproducibility was not dependent on Ecg gating. In measuring single arterial diameters and cross-sectional areas, the reproducibility was better when exposures were made 0.1 s after the R-wave maximum than when using other settings of the Ecg gating device or without Ecg gating. Conclusion: The influence of pulsatile flow upon quantitative measurement in femoral angiograms seems to be the smallest possible in early systole, as can be demonstrated when measuring single diameters and cross-sectional areas. In variables based on integration over longer segments, measurement reproducibility seems to be independent of phase

  14. Optimization of Ecg Gating in Quantitative Femoral Angiography

    Energy Technology Data Exchange (ETDEWEB)

    Nilsson, S.; Berglund, I.; Erikson, U. [Univ. Hospital, Uppsala (Sweden). Dept. of Oncology, Radiology and Clinical Immunology; Johansson, J.; Walldius, G. [Karolinska Hospital, Stockholm (Sweden). King Gustav V Research Inst.

    2003-09-01

    Purpose: To determine which phase of the heart cycle would yield the highest reproducibility in measuring atherosclerosis-related variables such as arterial lumen volume and edge roughness. Material and Methods: 35 patients with hypercholesterolemia underwent select ive femoral angiography, repeated four times at 10-min intervals. The angiographies were performed with Ecg-gated exposures. In angiographies 1 and 2 the delay from R-wave maximum to each exposure was 0.1 s, in angiographies 3 and 4 the delay was 0.1, 0.3, 0.5 or 0.7 s or the exposures were performed 1/s without Ecg gating. Arterial lumen volume and edge roughness were measured in a 20-cm segment of the superficial femoral artery using a computer-based densitometric method. Measurement reproducibility was determined by comparing angiographies 1-2 and angiographies 3-4. Results: When measuring arterial lumen volume and edge roughness of a 20-cm segment of the femoral artery, reproducibility was not dependent on Ecg gating. In measuring single arterial diameters and cross-sectional areas, the reproducibility was better when exposures were made 0.1 s after the R-wave maximum than when using other settings of the Ecg gating device or without Ecg gating. Conclusion: The influence of pulsatile flow upon quantitative measurement in femoral angiograms seems to be the smallest possible in early systole, as can be demonstrated when measuring single diameters and cross-sectional areas. In variables based on integration over longer segments, measurement reproducibility seems to be independent of phase.

  15. Quantitation of left ventricular asynchrony on radionuclide angiography phase images

    International Nuclear Information System (INIS)

    Alfano, B.; Betocchi, S.; Pace, L.; Perrone-Filardi, P.; Chiariello, M.; Salvatore, M.; Naples Univ.

    1990-01-01

    Quantitation of left ventricular (LV) asynchrony is relevant in clinical cardiology, as well as in evaluating LV mechanical properties. Radionuclide angiography (RA) phase images are extensively used, and asynchrony is usually assessed by computing the standard deviation of phase angle distribution (SD). However, SD is dependent on count statistics and does not take into account the spatial distribution of asynchrony. In this study a new index to evaluate asynchrony on phase images is presented (differential uniformity parameter, DUP). DUP is based on the frequency analysis of phase images. Diagnostic accuracy and reproducibility of either SD or DUP were tested. Reproducibility was evaluated in 15 patients studied by RA twice within a few minutes. DUP showed a better reproducibility than SD. Diagnostic accuracy was estimated in 84 patients, divided into four subgroups on the basis of coronary arteriography and contrast ventriculogrpahy findings: (a) 25 control subjects, (b) 16 patients with coronary artery disease (CAD) and normal LV wall motion, (c) 23 patients with CAD and LV hypokinesia and (d) 20 patients with CAD and LV dyskinesia. Relative diagnostic ability was assessed by comparing the areas under receiver-operating characteristic curves. DUP's area was larger than SD's when group D was tested against all the other groups (DUP's area=87%±5%, SD's area=76%±7%; P<0.01). Thus, our study indicates that DUP is more reproducible and more accurate than SD in identifying patients with CAD and LV dyskinesia. (orig.)

  16. Quantitative fluorescein angiography following diode laser retinal photocoagulation.

    Science.gov (United States)

    Mordon, S; Desmettre, T; Devoisselle, J M

    1999-01-01

    An in vivo study was done to establish if laser-induced damage of the retina could be quantified using fluorescein angiography. This study was carried out on rabbit eyes (n = 6) with an 810 nm diode laser (spot diameter: 500 microm, pulse duration: 1 second, power: 100 mW-400 mW) adapted on a slit lamp. Fluorescence measurements were performed with a fundus camera connected to a fluorescence imaging system. Fluorescence staining of the retina was evaluated by mathematical modeling. Lesions were correlated to laser parameters and to histologic data. Image analysis shows that the laser lesions stained progressively. Fluorescence appears first at the borders of the lesion exhibiting a fluorescent ring. A progressive increase of the fluorescence into the central zone is observed. The maximum fluorescence intensity into the center of the laser spot is obtained after a delay depending on the laser energy. Below 100 +/- 20 mW, lesions are detectable by fluorescence imaging only. A fluorescence plateau appears for a threshold light dose above 200 +/- 20 mW. Mathematical modeling demonstrates that quantitative assessment of laser-induced damage to the retina is feasible using fluorescence imaging. The quantification of fluorescence staining in terms of both intensity and time can contribute to a better quantification of laser-induced damage. At last, since laser damage may mimic naturally occurring pathology, this method should also be considered to quantify different types of lesions.

  17. Quantitative radionuclide angiography in assessment of hemodynamic changes during upright exercise: observations in normal subjects, patient with coronary artery disease and patients with aortic regurgitation

    International Nuclear Information System (INIS)

    Iskandrian, A.S.; Hakki, A.H.; Kane, S.A.; Segal, B.L.

    1981-01-01

    Quantitative radionuclide angiography was used to evaluate hemodynamic changes in three subject groups during symptom-limited upright exercise. The 12 normal subjects had significant increases in heart rate, stroke volume, left ventricular ejection fraction and cardiac output during exercise; changes in end-diastolic and end-systolic volumes were not significant. In the 24 patients with coronary artery disease there were significant increases in heart rate and cardiac output during exercise, but insignificant changes in end-diastolic, end-systolic and stroke volumes and ejection fraction. The change in diastolic volume in these patients was determined by the extent of coronary artery disease, propranolol therapy, end point of exercise and presence of collateral vessels. Furthermore, patients with previous myocardial infarction had a lower ejection fraction and higher end-diastolic and end-systolic volumes during exercise than those without myocardial infarction. In the 12 patients with chronic aortic regurgitation of moderate to severe degree, there was a decrease in the end-diastolic volume during exercise. This response was distinctly different from that of the normal subjects or the patients with coronary artery disease. All three groups had a significant decrease in pulmonary transit time during exercise. It is concluded that changes in cardiac output in normal subjects during upright exercise are related to augmentation of stroke volume and tachycardia, whereas in patients with coronary artery disease they are related mainly to tachycardia

  18. Assessment of anemia during CT pulmonary angiography

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    Jung, Caroline, E-mail: cjung@uke.de [Department of Diagnostic and Interventional Radiology, University Hospital Eppendorf, Martinistrasse 52, 20246 Hamburg (Germany); Groth, Michael; Bley, Thorsten A.; Henes, Frank O. [Department of Diagnostic and Interventional Radiology, University Hospital Eppendorf, Martinistrasse 52, 20246 Hamburg (Germany); Treszl, András [Department of Medical Biometry and Epidemiology, University Hospital Eppendorf, Martinistrasse 52, 20246 Hamburg (Germany); Adam, Gerhard; Bannas, Peter [Department of Diagnostic and Interventional Radiology, University Hospital Eppendorf, Martinistrasse 52, 20246 Hamburg (Germany)

    2012-12-15

    Objectives: Anemia is associated with increased mortality in patients with acute symptomatic pulmonary embolism (PE). The purpose of this study was to evaluate the feasibility of Hounsfield unit (HU) measurements on the single unenhanced trigger slice of pulmonary CT angiography scans for diagnosis of anemia. Material and Methods: 150 consecutive patients (median age 64 ± 16 years) with suspected PE underwent pulmonary CT angiography. Two radiologists, blinded to laboratory results, performed HU measurements in the single unenhanced trigger scan independently by region-based analysis (ROI). HU values from ascending and descending aorta and the calculated mean of both were correlated with serum hemoglobin levels. Inter- and intraobserver variability was determined for HU measurements, and ROC analysis was performed for diagnosis of anemia. Calculated linear models were used to assess formulas for estimation of hemoglobin levels from HU measurements. Results: HU measurements revealed high intra- and interrater reliability (ICC > 0.981 and ICC > 0.965, respectively). Calculated mean HU values showed a strong correlation with serum hemoglobin levels (r = 0.734), which allowed generation of different formulas for calculation of hemoglobin levels from HU measurements. ROC analyses confirmed a high sensitivity (80.4 for men; 91.3 for women) and specificity (84.0 for men; 84.9 for women) for diagnosing anemia. Conclusion: Diagnosis of anemia and quantification of hemoglobin levels upon a single unenhanced trigger scan of pulmonary CT angiography is feasible. We suggest disclosing the anemic state in the radiological report, independent of the presence of PE, since anemia carries increased risks of morbidity and mortality.

  19. Assessment of anemia during CT pulmonary angiography

    International Nuclear Information System (INIS)

    Jung, Caroline; Groth, Michael; Bley, Thorsten A.; Henes, Frank O.; Treszl, András; Adam, Gerhard; Bannas, Peter

    2012-01-01

    Objectives: Anemia is associated with increased mortality in patients with acute symptomatic pulmonary embolism (PE). The purpose of this study was to evaluate the feasibility of Hounsfield unit (HU) measurements on the single unenhanced trigger slice of pulmonary CT angiography scans for diagnosis of anemia. Material and Methods: 150 consecutive patients (median age 64 ± 16 years) with suspected PE underwent pulmonary CT angiography. Two radiologists, blinded to laboratory results, performed HU measurements in the single unenhanced trigger scan independently by region-based analysis (ROI). HU values from ascending and descending aorta and the calculated mean of both were correlated with serum hemoglobin levels. Inter- and intraobserver variability was determined for HU measurements, and ROC analysis was performed for diagnosis of anemia. Calculated linear models were used to assess formulas for estimation of hemoglobin levels from HU measurements. Results: HU measurements revealed high intra- and interrater reliability (ICC > 0.981 and ICC > 0.965, respectively). Calculated mean HU values showed a strong correlation with serum hemoglobin levels (r = 0.734), which allowed generation of different formulas for calculation of hemoglobin levels from HU measurements. ROC analyses confirmed a high sensitivity (80.4 for men; 91.3 for women) and specificity (84.0 for men; 84.9 for women) for diagnosing anemia. Conclusion: Diagnosis of anemia and quantification of hemoglobin levels upon a single unenhanced trigger scan of pulmonary CT angiography is feasible. We suggest disclosing the anemic state in the radiological report, independent of the presence of PE, since anemia carries increased risks of morbidity and mortality.

  20. Semi-automatic quantitative measurements of intracranial internal carotid artery stenosis and calcification using CT angiography

    International Nuclear Information System (INIS)

    Bleeker, Leslie; Berg, Rene van den; Majoie, Charles B.; Marquering, Henk A.; Nederkoorn, Paul J.

    2012-01-01

    Intracranial carotid artery atherosclerotic disease is an independent predictor for recurrent stroke. However, its quantitative assessment is not routinely performed in clinical practice. In this diagnostic study, we present and evaluate a novel semi-automatic application to quantitatively measure intracranial internal carotid artery (ICA) degree of stenosis and calcium volume in CT angiography (CTA) images. In this retrospective study involving CTA images of 88 consecutive patients, intracranial ICA stenosis was quantitatively measured by two independent observers. Stenoses were categorized with cutoff values of 30% and 50%. The calcification in the intracranial ICA was qualitatively categorized as absent, mild, moderate, or severe and quantitatively measured using the semi-automatic application. Linear weighted kappa values were calculated to assess the interobserver agreement of the stenosis and calcium categorization. The average and the standard deviation of the quantitative calcium volume were calculated for the calcium categories. For the stenosis measurements, the CTA images of 162 arteries yielded an interobserver correlation of 0.78 (P < 0.001). Kappa values of the categorized stenosis measurements were moderate: 0.45 and 0.58 for cutoff values of 30% and 50%, respectively. The kappa value for the calcium categorization was 0.62, with a good agreement between the qualitative and quantitative calcium assessment. Quantitative degree of stenosis measurement of the intracranial ICA on CTA is feasible with a good interobserver agreement ICA. Qualitative calcium categorization agrees well with quantitative measurements. (orig.)

  1. Quantitative coronary angiography in the estimation of the functional significance of coronary stenosis: correlations with dobutamine-atropine stress test

    NARCIS (Netherlands)

    J.M.P. Baptista da Silva (José); M. Arnese (Mariarosaria); J.R.T.C. Roelandt (Jos); P.M. Fioretti (Paolo); D.T.J. Keane (David); J. Escaned (Javier); C. di Mario (Carlo); P.W.J.C. Serruys (Patrick); H. Boersma (Eric)

    1994-01-01

    textabstractOBJECTIVES. The purpose of this study was to determine the predictive value of quantitative coronary angiography in the assessment of the functional significance of coronary stenosis as judged from the development of left ventricular wall motion abnormalities during dobutamine-atropine

  2. Angiography

    International Nuclear Information System (INIS)

    Grinnell, V.S.; Mehringer, C.M.; Hieshima, G.B.

    1987-01-01

    The history of angiography is short, with its centennial approaching. A very brief review of milestones begins with the discovery of x-rays in 1895. Only a few months later contrast agents too toxic for human use were being injected into cadavers, severed limbs, and animals. The next major developments came in the late 1970s when percutaneous translumbar aortography and cerebral angiography were described. Contrast agents were now less toxic, and clinically useful angiography was a reality. In 1953 a technique for percutaneous vascular catheterization which formed the basis of many catheterization techniques to follow was described. In the 1970s the development of less invasive diagnostic methods such as computed tomography and diagnostic ultrasound decreased the indications for angiography, but newer interventional techniques such as embolization therapy and angioplasty have taken up the slack. Angiography remains the most important way to demonstrate vascular diseases graphically. Specific techniques such as angioplasty and digital subtraction angiography will be dealt with in other chapters. The authors hope to provide an overview of major areas of angiographic utilization. The basic techniques of arterial puncture and catheterization have been well described elsewhere

  3. ROLE OF ULTRASONOGRAPHY, CONVENTIONAL ANGIOGRAPHY, CT AND CT ANGIOGRAPHY IN ASSESSMENT OF MESENTERIC ISCHAEMIA

    Directory of Open Access Journals (Sweden)

    Reena

    2016-05-01

    Full Text Available AIM The aim of the study was to evaluate efficacy, sensitivity, specificity of ultrasonography, conventional angiography, CT Angiography in mesenteric ischaemia. MATERIALS AND METHODS Prospective study was performed. 35 patients with clinically suspected mesenteric ischaemia were included in the study. The study was conducted from month of November 2013 to August 2015. The patients age ranged from 35 to 70 years (Mean age was 57±11.2 years. All cases met the criteria of acute nontraumatic or chronic abdominal pain and suspected mesenteric vascular ischaemia. All 35 cases were evaluated in surgery department, then underwent USG, conventional angiography, CTA. Out of 20 patients, 2 patients were inconclusive and 4 patients had other findings of abdominal pain. USG and CT angiographic findings were correlated with surgical findings in acute mesenteric ischaemia (AMI cases & conventional angiography in chronic mesenteric ischaemia (CMI cases. RESULT Ultrasonography has lower sensitivity and high specificity. Conventional angiography has moderate sensitivity and high specificity. CT angiography is highly sensitive and specific in detecting mesenteric ischaemia. CONCLUSION Conventional angiography is considered as the gold standard test for patients with acute and chronic mesenteric ischaemia except for hemodynamically unstable patients with acute mesenteric ischaemia. CTA is an emerging diagnostic test with high sensitivity and specificity in the setting of both acute and chronic mesenteric ischaemia and should be considered the first-line imaging test. CT can also accurately assess for other causes of acute and chronic abdominal pain, and it provides excellent anatomic mapping of the mesenteric vasculature, which is essential in the preoperative planning. US of the abdomen with Doppler waveform analysis can depict proximal mesenteric thrombosis and secondary signs of bowel compromise, but it is limited in the diagnosis of distal occlusions

  4. Novel bifurcation phantoms for validation of quantitative coronary angiography algorithms.

    Science.gov (United States)

    Girasis, Chrysafios; Schuurbiers, Johan C H; Onuma, Yoshinobu; Serruys, Patrick W; Wentzel, Jolanda J

    2011-05-01

    Validation is lacking for two- and three-dimensional (2D and 3D) bifurcation quantitative coronary angiography (QCA) algorithms. Six plexiglas phantoms were designed, each of them mimicking a coronary vessel with three successive bifurcations lesions, wherein at least one vessel segment had a percent diameter stenosis (DS) of ≥60%. The five most frequently occurring Medina classes (1,1,1), (1,1,0), (0,1,0), (0,1,1), and (1,0,0) were used in the design. Diameters of the daughter vessels in every bifurcation were dictated by the scaling law of Finet. Lesions were cosinus-shaped in longitudinal view and circular-shaped in cross-sectional view. At the level of the carina, lesions were becoming eccentric, favoring "plaque" at the outer bifurcation walls. Adjacent bifurcation lesions were kept distant by nontapering, stenosis-free segments of ≥10 mm length. The direction of the side branch relative to the main vessel was based on relevant literature. The phantoms were precision manufactured using computer-aided design and machining techniques. Because of the high drilling accuracy (within 10 μm), the 3D luminal surface description of the phantom could be used to determine the true lumen dimensions and bifurcation angle (BA) values of the final geometry. Our series of bifurcation phantoms comprised 33 narrowed and 21 stenosis-free vessel segments with a mean true minimal lumen diameter (MLD) value of 0.98 ± 0.40 mm (range, 0.53-1.96 mm) and 2.29 ± 0.74 mm (range, 1.40-4.00 mm), respectively. Overall, the mean true values for MLD, reference diameter, and DS were 1.49 ± 0.85 mm, 2.70 ± 0.71 mm, and 40.9% ± 34.2%. The mean true values for the proximal and the distal BA were 123.6° ± 19.0° and 69.6° ± 19.9°, respectively. Six plexiglas phantoms containing a total of 18 bifurcations lesions with variable anatomy and Medina class were designed and precision manufactured to facilitate the validation of bifurcation QCA algorithms. Copyright © 2010 Wiley-Liss, Inc.

  5. Quantitative angiography methods for bifurcation lesions: a consensus statement update from the European Bifurcation Club.

    Science.gov (United States)

    Collet, Carlos; Onuma, Yoshinobu; Cavalcante, Rafael; Grundeken, Maik; Généreux, Philippe; Popma, Jeffrey; Costa, Ricardo; Stankovic, Goran; Tu, Shengxian; Reiber, Johan H C; Aben, Jean-Paul; Lassen, Jens Flensted; Louvard, Yves; Lansky, Alexandra; Serruys, Patrick W

    2017-05-15

    Bifurcation lesions represent one of the most challenging lesion subsets in interventional cardiology. The European Bifurcation Club (EBC) is an academic consortium whose goal has been to assess and recommend the appropriate strategies to manage bifurcation lesions. The quantitative coronary angiography (QCA) methods for the evaluation of bifurcation lesions have been subject to extensive research. Single-vessel QCA has been shown to be inaccurate for the assessment of bifurcation lesion dimensions. For this reason, dedicated bifurcation software has been developed and validated. These software packages apply the principles of fractal geometry to address the "step-down" in the bifurcation and to estimate vessel diameter accurately. This consensus update provides recommendations on the QCA analysis and reporting of bifurcation lesions based on the most recent scientific evidence from in vitro and in vivo studies and delineates future advances in the field of QCA dedicated bifurcation analysis.

  6. Three dimensional quantitative coronary angiography can detect reliably ischemic coronary lesions based on fractional flow reserve.

    Science.gov (United States)

    Chung, Woo-Young; Choi, Byoung-Joo; Lim, Seong-Hoon; Matsuo, Yoshiki; Lennon, Ryan J; Gulati, Rajiv; Sandhu, Gurpreet S; Holmes, David R; Rihal, Charanjit S; Lerman, Amir

    2015-06-01

    Conventional coronary angiography (CAG) has limitations in evaluating lesions producing ischemia. Three dimensional quantitative coronary angiography (3D-QCA) shows reconstructed images of CAG using computer based algorithm, the Cardio-op B system (Paieon Medical, Rosh Ha'ayin, Israel). The aim of this study was to evaluate whether 3D-QCA can reliably predict ischemia assessed by myocardial fractional flow reserve (FFR) < 0.80. 3D-QCA images were reconstructed from CAG which also were evaluated with FFR to assess ischemia. Minimal luminal diameter (MLD), percent diameter stenosis (%DS), minimal luminal area (MLA), and percent area stenosis (%AS) were obtained. The results of 3D-QCA and FFR were compared. A total of 266 patients was enrolled for the present study. FFR for all lesions ranged from 0.57 to 1.00 (0.85 ± 0.09). Measurement of MLD, %DS, MLA, and %AS all were significantly correlated with FFR (r = 0.569, 0609, 0.569, 0.670, respectively, all P < 0.001). In lesions with MLA < 4.0 mm(2), %AS of more than 65.5% had a 80% sensitivity and a 83% specificity to predict FFR < 0.80 (area under curve, AUC was 0.878). 3D-QCA can reliably predict coronary lesions producing ischemia and may be used to guide therapeutic approach for coronary artery disease.

  7. Difference of coronary stenosis severity between systolic and diastolic phases in quantitative CT angiography.

    Science.gov (United States)

    Gu, Hui; Gao, Yang; Wang, Haiping; Li, Zhennan; Xu, Liang; Xu, Bo; Wang, Ximing; Lu, Bin

    To compare the difference of coronary diameter stenosis by quantitative analysis of CT angiography (QCT) in the systolic (QCT-S) and diastolic phase (QCT-D) of the cardiac cycle, with invasive catheter angiography (QCA) as reference standard. A total of 109 patients (57.5 ± 10.6 years, 78.9% male) with suspected coronary artery disease (CAD) who underwent both CT angiography and invasive catheter angiography were retrospectively included in this study. Coronary diameter stenoses in systolic and diastolic coronary CTA reconstructions were compared with QCA. Mean time interval between CT angiography and invasive angiography was 17.4 ± 4.4 days. QCT-D overestimated coronary diameter stenosis by 5.7%-8.5% while QCT-S overestimated coronary diameter stenosis by 9.4%-11.9% (p < 0.05). In calcified lesions, QCT-D overestimated coronary diameter stenosis by 13.2 ± 4.3%, while QCT-S overestimated by stenosis by 16.6 ± 4.3% (p < 0.05). Coronary diameter stenosis was overestimated by QCT-D as well as QCT-S, respectively, when compared with QCA. Overestimation was more pronounced in calcified lesions. Copyright © 2017 Society of Cardiovascular Computed Tomography. Published by Elsevier Inc. All rights reserved.

  8. Assessment of "silent" restenosis and long-term follow-up after successful angioplasty in single vessel coronary artery disease: the value of quantitative exercise electrocardiography and quantitative coronary angiography

    NARCIS (Netherlands)

    Laarman, G.; Luijten, H. E.; van Zeyl, L. G.; Beatt, K. J.; Tijssen, J. G.; Serruys, P. W.; de Feyter, J.

    1990-01-01

    Exercise electrocardiographic (ECG) testing during follow-up after coronary angioplasty is widely applied to evaluate the efficacy of angioplasty, even in asymptomatic patients. One hundred forty-one asymptomatic patients without previous myocardial infarction underwent quantitative exercise ECG

  9. MR angiography and flow quantitation in the portal venous system

    International Nuclear Information System (INIS)

    Edelman, R.R.; Finn, J.P.; Wentz, K.U.; Zhao, B.; Liu, C.; Mattle, H.; Longmaid, H.E.; McArdle, C.

    1989-01-01

    MR angiography was used to image the portal venous system. Projection venograms were produced from a series of two-dimensional flow-compensated gradient-echo images obtained during breath holding. The authors determined flow direction and velocity by means of dynamic bolus tracking. Six healthy subjects and four patients with portal hypertension were studied. This technique was able to demonstrate consistently the main portal vein and intrahepatic branches, the splenic vein, and the superior and inferior mesenteric veins. Peak flow velocities as determined with MR imaging (17.9 cm/sec ± 2.8) correlated closely with those measured with duplex US (17.5 cm/sec ± 2.2) (r = .846, P<.04). Reversal of portal flow, portal vein thrombosis, and portosystemic collaterals were well shown

  10. Integrated prediction of lesion-specific ischaemia from quantitative coronary CT angiography using machine learning

    DEFF Research Database (Denmark)

    Dey, Damini; Gaur, Sara; Ovrehus, Kristian A

    2018-01-01

    OBJECTIVES: We aimed to investigate if lesion-specific ischaemia by invasive fractional flow reserve (FFR) can be predicted by an integrated machine learning (ML) ischaemia risk score from quantitative plaque measures from coronary computed tomography angiography (CTA). METHODS: In a multicentre...

  11. Atherosclerotic carotid plaque assessment with multidetector computed tomography angiography

    NARCIS (Netherlands)

    T.T. de Weert (Thomas)

    2009-01-01

    textabstractThis thesis evaluates the role of MDCT angiography in 1) the depiction of atherosclerotic disease and subsequent luminal stenosis in the arteries that supplies the brain with blood, and 2) the assessment of atherosclerotic plaque features that have been related to plaque vulnerability.

  12. Reproducibility and Reliability of Repeated Quantitative Fluorescence Angiography

    DEFF Research Database (Denmark)

    Nerup, Nikolaj; Knudsen, Kristine Bach Korsholm; Ambrus, Rikard

    2017-01-01

    that the camera can detect. As the emission of fluorescence is dependent of the excitatory light intensity, reduction of this may solve the problem. The aim of the present study was to investigate the reproducibility and reliability of repeated quantitative FA during a reduction of excitatory light....

  13. Influence of radiographic contrast agents on quantitative coronary angiography

    International Nuclear Information System (INIS)

    Jost, Stefan; Hausmann, Dirk; Lippolt, Peter; Gerhardt, Uwe; Lichtlen, Paul R.

    1997-01-01

    Purpose. Quantitative angiographic studies on the vasomotility of epicardial coronary arteries are gaining increasing relevance. We investigated whether radiographic contrast agents might influence coronary vasomotor tone and thereby the results of such studies. Methods. Coronary angiograms were taken in 12 patients with coronary artery disease at intervals of 5, 3, 2, and 1 min with the low-osmolar, nonionic contrast agent iopamidol 300, and were repeated at identical intervals with the high-osmolar, ionic agent diatrizoate 76%. Results. Quantitative cine film analysis demonstrated no significant diameter changes in angiographically normal and stenotic coronary arteries with iopamidol. With diatrizoate, however, normal segments were dilated 2%±2% (p<0.01) after 2 min and 10%±3% after the 1 min interval (p<0.001). Stenoses showed no uniform responses to diatrizoate. Conclusion. Low-osmolar, nonionic contrast agents should be preferred for quantitative angiographic studies on epicardial coronary vasomotility. When using ionic contrast agents, injection intervals of at least 3 min are required

  14. 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-angiography

  15. Clinical Assessment of a New Stereoscopic Digital Angiography System

    International Nuclear Information System (INIS)

    Moll, Thierry; Douek, Philippe; Finet, Gerard; Turjman, Francis; Picard, Catherine; Revel, Didier; Amiel, Michel

    1998-01-01

    Purpose: To assess the clinical feasibility of an experimental modified angiographic system capable of real-time digital stereofluoroscopy and stereography in X-ray angiography, using a twin-focus tube and a stereoscopic monitor. Methods: We report the experience obtained in 37 patients with a well-documented examination. The patients were examined for coronary angiography (11 cases), aortography (7 cases), pulmonary angiography (6 cases), inferior vena cava filter placement (2 cases), and cerebral angiography (11 cases). Six radiologists were asked to use stereoscopic features for fluoroscopy and angiography. A questionnaire was designed to record their subjective evaluation of stereoscopic image quality, ergonomics of the system, and its medical interest. Results: Stereofluoroscopy was successfully used in 25 of 37 cases; diplopia and/or ghost images were reported in 6 cases. It was helpful for aortic catheterization in 10 cases and for selective catheterization in 5 cases. In stereoangiography, depth was easily and accurately perceived in 27 of 37 cases; diplopia and/or ghost images were reported in 4 cases. A certain gain in the three-dimensional evaluation of the anatomy and relation between vessels and lesions was noted. As regards ergonomic considerations, polarized spectacles were not considered cumbersome. Visual fatigue and additional work were variously reported. Stereoshift tuning before X-ray acquisition was not judged to be a limiting factor. Conclusion: A twin-focus X-ray tube and a polarized shutter for stereoscopic display allowed effective real-time three-dimensional perception of angiographic images. Our clinical study suggests no clear medical interest for diagnostic examinations, but the field of interventional radiology needs to be investigated

  16. Influence of vessel stenosis on indocyanine green fluorescence intensity assessed by near-infrared fluorescence angiography.

    Science.gov (United States)

    Yamamoto, Masaki; Nishimori, Hideaki; Fukutomi, Takashi; Handa, Takemi; Kihara, Kazuki; Tashiro, Miwa; Sato, Takayuki; Orihashi, Kazumasa

    2017-07-01

    Although useful for visualizing blood flow during revascularization surgery, the permeability of near-infrared fluorescence (NIR) angiography using indocyanine green (ICG) does not allow for vessel stenosis visualization. We hypothesized that changes in ICG fluorescence intensity reflect vessel stenosis, and evaluated the influence of stenosis on blood flow by ex vivo experimentation. The vessel stenosis model comprised a silicon tube, a graft occluder, and artificial blood. During near-infrared angiography, the fluorescense intensity was calculated during pre- and post-stenosis of an artificial circuit, using a NIR angiography. We measured the maximum fluorescence intensity and the time to maximum fluorescence intensity. Severe stenosis (≥75%) attenuated the increase in ICG fluorescence intensity in the tube significantly, pre- and post-stenosis. The time to maximum fluorescence intensity did not differ between sites pre- and post-stenosis, irrespective of stenosis severity. Stenosis affected the ICG fluorescence intensity through the vessel. Thus, quantitative analysis using NIR angiography may detect severe vessel stenosis (≥75%), and the extinction curve of indocyanine fluorescence intensity may support the evaluation of blood flow. The absence of differences in the time to maximum fluorescence intensity for degrees of stenosis might suggest a limitation of previous conventional qualitative assessments.

  17. Digital subtraction angiography in the assessment of cardiovascular disease

    International Nuclear Information System (INIS)

    Harrington, D.P.; Boxt, L.M.

    1985-01-01

    Digital subtraction angiography (DSA) is a new radiographic method for evaluating the cardiovascular system. It represents another in a continuing series of computer-assisted diagnostic imaging modalities. The advantages of this technique are its relatively noninvasive nature combined with diagnostically acceptable angiographic images of a variety of cardiovascular structures. Major clinical applications of DSA include its use in imaging of localized regions of peripheral arterial disease and as a screening procedure in evaluating extracranial carotid and vertebral artery disease and renovascular hypertension. Cardiac applications of DSA include assessment of ventricular function, recognition and quantification of intracardiac shunts, visualization of coronary artery bypass grafts, and the study of complex congenital cardiac malformations. Digital subtraction angiography may also be used to evaluate intracranial aneurysms and vascular tumors

  18. Assessment of vessel diameters for MR brain angiography processed images

    Science.gov (United States)

    Moraru, Luminita; Obreja, Cristian-Dragos; Moldovanu, Simona

    2015-12-01

    The motivation was to develop an assessment method to measure (in)visible differences between the original and the processed images in MR brain angiography as a method of evaluation of the status of the vessel segments (i.e. the existence of the occlusion or intracerebral vessels damaged as aneurysms). Generally, the image quality is limited, so we improve the performance of the evaluation through digital image processing. The goal is to determine the best processing method that allows an accurate assessment of patients with cerebrovascular diseases. A total of 10 MR brain angiography images were processed by the following techniques: histogram equalization, Wiener filter, linear contrast adjustment, contrastlimited adaptive histogram equalization, bias correction and Marr-Hildreth filter. Each original image and their processed images were analyzed into the stacking procedure so that the same vessel and its corresponding diameter have been measured. Original and processed images were evaluated by measuring the vessel diameter (in pixels) on an established direction and for the precise anatomic location. The vessel diameter is calculated using the plugin ImageJ. Mean diameter measurements differ significantly across the same segment and for different processing techniques. The best results are provided by the Wiener filter and linear contrast adjustment methods and the worst by Marr-Hildreth filter.

  19. Assessment Of Coronary Arterial Stents By Multislice-CT Angiography

    International Nuclear Information System (INIS)

    Maintz, D.; Fallenberg, E. M.; Heindel, W.; Fischbach, R.; Grude, M.

    2003-01-01

    Purpose: To assess patency and lumen visibility of coronary artery stents by multislice-CT angiography (MSCTA) in comparison with conventional coronary angiography as the standard of reference. Material and Methods: 47 stents of 13 different types were evaluated in 29 patients. MSCTA was performed on a 4-slice scanner with a standard coronary protocol (detector collimation 4 x 1 mm; table feed 1.5 mm/rotation, 400 mAs, 120 kV). Image evaluation was performed by two readers who were blinded to the reports from the catheter angiography. MIP reconstructions were evaluated for image quality on a 4-point scale (1 = poor, 4 = excellent) and stent patency (contrast distal to the stent as an indirect patency sign). Axial images and multiplanar reformations through the stents were used for assessment of stent lumen visibility (measurement of the visible stent lumen diameter) and detection of relevant in-stent stenosis (50%). Results: Image quality was fair to good on average (score 2.64 ± 1.0) and depended on the heart rate (heart rate 45-60: average score 3.2, heart rate 61-70: average score 2.8, heart rate >71: average score 1.4). Thirty-seven stents were correctly classified as patent, 1 was correctly classified as occluded and 9 stents were not assessable due to insufficient image quality because of triggering artifacts. Parts of the stent lumen could be visualized in 30 cases. On average, 20-40% of the stent lumen diameter was visible. Twenty-five stents were correctly classified as having no stenosis, 1 was falsely classified as stenosed, 1 was correctly classified as occluded. In 20 stents lumen visibility was not sufficient for stenosis evaluation. Conclusion: Although the stent lumen may be partly visualized in most stents, a reliable evaluation of in-stent stenoses does not seem practical by 4-slice MSCT. Nevertheless, for stent patency evaluation, MS-CTA might provide valuable clinical information. With submillimeter MSCT (e.g. 16-slice scanners) and more

  20. OCT Angiography: Assessment of Retinal Ischemia in Susac's Syndrome.

    Science.gov (United States)

    Spiess, Karina; Martínez, Jesús Ramón García

    2017-06-01

    Descriptive study of two patients affected by Susac's syndrome (SuS) focusing on the chronic retinal tissue damage assessed by optical coherence tomography (OCT) and OCT angiography (OCTA). To the authors' knowledge, this is the first case series reporting OCTA in SuS. OCTA imaging revealed secondary hypoxia due to branch retinal artery occlusion of the deep capillary plexus, with additional involvement of the superficial capillary network in one case. OCTA is a noninvasive and quick diagnostic tool for detecting hypoxic retinal damage in SuS. With further development of OCTA, as wide-field imaging, a better understanding of the retinal and choroidal blood supply will be gained. [Ophthalmic Surg Lasers Imaging Retina. 2017;48:505-508.]. Copyright 2017, SLACK Incorporated.

  1. Quantitative plaque features from coronary computed tomography angiography to identify regional ischemia by myocardial perfusion imaging.

    Science.gov (United States)

    Diaz-Zamudio, Mariana; Fuchs, Tobias A; Slomka, Piotr; Otaki, Yuka; Arsanjani, Reza; Gransar, Heidi; Germano, Guido; Berman, Daniel S; Kaufmann, Philipp A; Dey, Damini

    2017-05-01

    We aimed to investigate whether quantitative plaque features measured from coronary CT angiography (CCTA) predict ischemia by myocardial perfusion SPECT imaging (MPI). Hundred and eighty-four consecutive patients (63% males) with suspected-coronary artery disease, undergoing hybrid CCTA, and attenuation corrected solid state 99mTc stress/rest MPI and single vessel ischemia were considered. Quantitative analysis of CCTA derived non-calcified plaque (NCP), low-density NCP [difference (CD, maximum difference in HU/lumen area within lesion). Normal thresholds for plaque features were defined as 95th percentile thresholds, from 40% of vessels with non-ischemic MPI regions. These vessels were excluded from further analysis. Regional ischemia (≥ 2%) was quantified from MPI. All plaque features were higher in arteries corresponding to ischemia (P Quantitative plaque features obtained from CCTA, LDNCP, and CD, are associated with ischemia by MPI independent of stenosis. LDNCP burden and CD are associated with ischemia in stenosis 30-69% and ≥ 70%, respectively. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2016. For permissions, please email: journals.permissions@oup.com.

  2. American College of Cardiology/ European Society of Cardiology international study of angiographic data compression phase II. The effects of varying JPEG data compression levels on the quantitative assessment of the degree of stenosis in digital coronary angiography.

    Science.gov (United States)

    Tuinenburg, J C; Koning, G; Hekking, E; Zwinderman, A H; Becker, T; Simon, R; Reiber, J H

    2000-04-01

    This report describes whether lossy Joint Photographic Experts Group (JPEG) image compression/decompression has an effect on the quantitative assessment of vessel sizes by state-of-the-art quantitative coronary arteriography (QCA). The Digital Imaging and Communications in Medicine (DICOM) digital exchange standard for angiocardiography prescribes that images must be stored loss free, thereby limiting JPEG compression to a maximum ratio of 2:1. For practical purposes it would be desirable to increase the compression ratio (CR), which would lead to lossy image compression. A series of 48 obstructed coronary segments were compressed/decompressed at CR 1:1 (uncompressed), 6:1, 10:1 and 16:1 and analyzed blindly and in random order using the QCA-CMS analytical software. Similar catheter and vessel start- and end-points were used within each image quartet, respectively. All measurements were repeated after several weeks using newly selected start- and end-points. Three different sub-analyses were carried out: the intra-observer, fixed inter-compression and variable inter-compression analyses, with increasing potential error sources, respectively. The intra-observer analysis showed significant systematic and random errors in the calibration factor at JPEG CR 10:1. The fixed inter-compression analysis demonstrated systematic errors in the calibration factor and recalculated vessel parameter results at CR 16:1 and for the random errors at CR 10:1 and 16:1. The variable inter-compression analysis presented systematic and random errors in the calibration factor and recalculated parameter results at CR 10:1 and 16:1. Any negative effect at CR 6:1 was found only for the calibration factor of the variable inter-compression analysis, which did not show up in the final vessel measurements. Compression ratios of 10:1 and 16:1 affected the QCA results negatively and therefore should not be used in clinical research studies. Copyright 2000 The European Society of Cardiology.

  3. Assessment of the Circle of Willis with Cranial Tomography Angiography.

    Science.gov (United States)

    Karatas, Ayse; Coban, Gokmen; Cinar, Celal; Oran, Ismail; Uz, Aysun

    2015-09-06

    The circle of Willis is a major collateral pathway important in ischemic conditions. The aim of our study was to assess the structural characteristics of the circle of Willis within the Turkish adult population, along with variations and arteries involved in the measurement of diameters and lengths on cranial computed tomography angiography (CTA). One hundred adult patients who underwent CTA images were evaluated retrospectively. Results of the study revealed 82% adult, 17% fetal, and 1% transitional configurations. A complete polygonal structure was observed in 28% of cases. Variations of the circle of Willis were more common in the posterior portion. Hypoplasia was found to be the most common variation and was observed as a maximum in the posterior communicating artery (AComP). The patency and size of arteries in the circle of Willis are important in occlusive cerebrovascular diseases and cerebrovascular surgery. Although CTA is an easily accessible non-invasive clinical method for demonstrating the vascular structure, CTA should be evaluated taking into account image resolution quality and difficulties in the identification of small vessels.

  4. Contribution of quantitative coronary angiography in Palmaz-Schatz optimal stent liberation strategy for subacute occlusion control

    International Nuclear Information System (INIS)

    Sousa, Amanda Guerra de Moraes Rego

    1995-01-01

    This study examines whether a single method, quantitative coronary angiography with automated edge detection, could efficiently guide optimal stent liberation, assuring good clinical results and eliminating the need for anticoagulation therapy. This investigation includes 101 patients with optimal implantation of 104 Palmaz-stents. Their mean age was 58.62 years and 79.2% were male. Most of them presented unstable angina (61.39%) and had single vessel disease (85.15%) The treated vessel was the left anterior descending artery in 39.60%; the right coronary artery in 34.66%; the left circumflex artery in 7.92% and saphenous vein grafts in 17.82%. The mean reference diameter of the target vessel was 3.43 mm. Each implantation comprehended two phases: initial stent liberation and additional high pressure balloon inflation, guided by quantitative coronary angiography. Arterial quantification showed an important increase in the mean luminal diameter (p<0.001), characterized by an immediate gain of 2.37 mm [standard deviation (SD): 0.55 m]. Quantitative angiography permitted to identify a further gain in the luminal diameter following the high pressure balloon inflation, o.49 mm 9 SD:0.53 mm). Therefore, the total mean immediate gain was 2.85 mm (SD:0.64 mm). The mean diameter stenosis changed from 80.21% (SD:14.56%) to 11.81% (SD: 7.59% - p<0.001) after initial stent delivery; and to 0.16% (SD:3.45% - p<,0.001), after high pressure balloon inflation. Quantitative coronary angiography performed detailed measurements of the minimal caliber variations along the entire prosthesis due to the high pressure balloon inflations, similarly to the intracoronary ultrasound. This guided the optimal stent implantation and helped the clinical management of these cases. In this series, even maintained only under antiaggregant agents, no patient presented major ischemic complications and only one (0.99%) had a hemorrhage in the puncture site that required blood transfusion. The mean in

  5. Cerebrovascular reactivity by quantitative magnetic resonance angiography with a co{sub 2} challenge. Validation as a new imaging biomarker

    Energy Technology Data Exchange (ETDEWEB)

    Caputi, Luigi, E-mail: lcaputi@istituto-besta.it [Department of Cerebrovascular Diseases, Fondazione IRCCS Neurological Institute C. Besta, Via Celoria 11, 20133 Milan (Italy); Ghielmetti, Francesco, E-mail: Francesco.Ghielmetti@istituto-besta.it [Department of Neuroradiology, Fondazione IRCCS Neurological Institute C. Besta, Via Celoria 11, 20133 Milan (Italy); Faragò, Giuseppe, E-mail: Giuseppe.Farago@istituto-besta.it [Department of Neuroradiology, Fondazione IRCCS Neurological Institute C. Besta, Via Celoria 11, 20133 Milan (Italy); Longaretti, Fabio, E-mail: fabio.longaretti@libero.it [Department of Neuroradiology, Fondazione IRCCS Neurological Institute C. Besta, Via Celoria 11, 20133 Milan (Italy); Lamperti, Massimo, E-mail: docmassimomd@gmail.com [Department of Neuroanesthesia and Intensive Care, Fondazione IRCCS Neurological Institute C. Besta, Via Celoria 11, 20133 Milan (Italy); Anzola, Gian Paolo, E-mail: gpanzola@speedyposta.it [Service of Neurology, S. Orsola Hospital, Fondazione Poliambulanza, Via Vittorio Emanuele II 27, 25122 Brescia (Italy); Carriero, Maria Rita, E-mail: MariaRita.Carriero@istituto-besta.it [Department of Cerebrovascular Diseases, Fondazione IRCCS Neurological Institute C. Besta, Via Celoria 11, 20133 Milan (Italy); Charbel, Fady T., E-mail: fcharbel@uic.edu [Department of Neurosurgery, University of Illinois at Chicago College of Medicine, Chicago, IL 60612 (United States); Bruzzone, Maria Grazia, E-mail: Maria.Bruzzone@istituto-besta.it [Department of Neuroradiology, Fondazione IRCCS Neurological Institute C. Besta, Via Celoria 11, 20133 Milan (Italy); Parati, Eugenio, E-mail: Eugenio.Parati@istituto-besta.it [Department of Cerebrovascular Diseases, Fondazione IRCCS Neurological Institute C. Besta, Via Celoria 11, 20133 Milan (Italy); Ciceri, Elisa, E-mail: Elisa.Ciceri@istituto-besta.it [Department of Neuroradiology, Fondazione IRCCS Neurological Institute C. Besta, Via Celoria 11, 20133 Milan (Italy)

    2014-06-15

    Assessment of cerebrovascular reactivity (CVR) is essential in cerebrovascular diseases, as exhausted CVR may enhance the risk of cerebral ischemic events. Transcranial Doppler (TCD) with a vasodilatory stimulus is currently used for CVR evaluation. Scanty data are available for Quantitative Magnetic Resonance Angiography (QMRA), which supplies higher spatial resolution and quantitative cerebral blood flow values. Aims of our pilot study were: (a) to assess safety and feasibility of CO{sub 2} administration during QMRA, (b) evaluation of CVR under QMRA compared to TCD, and (c) quantitative evaluation of blood flow from the major intracranial arterial vessels both at rest and after CO{sub 2}. CVR during 5% CO{sub 2} air breathing was measured with TCD as a reference method and compared with QMRA. Fifteen healthy subjects (age 60.47 ± 2.24; male 11/15) were evaluated at rest and during CO{sub 2} challenge. Feasibility and safety of QMRA under CO{sub 2} were ensured in all subjects. CVR from middle cerebral artery territory was not statistically different between TCD and MRI (p > 0.05). Mean arterial pressure (MAP) and heart rate (HR) increased during QMRA and TCD (MAP p = 0.007 and p = 0.001; HR p = 0.043 and p = 0.068, respectively). Blood flow values from all intracranial vessels increased after CO{sub 2} inhalation (p < 0.001). CO{sub 2} administration during QMRA sessions is safe and feasible. Good correlation in terms of CVR was obtained comparing TCD and QMRA. Blood flow values significantly increased from all intracranial arterial vessels after CO{sub 2}. Studies regarding CVR in physiopathological conditions might consider the utilization of QMRA both in routine clinical settings and in research projects.

  6. Cerebrovascular reactivity by quantitative magnetic resonance angiography with a co2 challenge. Validation as a new imaging biomarker

    International Nuclear Information System (INIS)

    Caputi, Luigi; Ghielmetti, Francesco; Faragò, Giuseppe; Longaretti, Fabio; Lamperti, Massimo; Anzola, Gian Paolo; Carriero, Maria Rita; Charbel, Fady T.; Bruzzone, Maria Grazia; Parati, Eugenio; Ciceri, Elisa

    2014-01-01

    Assessment of cerebrovascular reactivity (CVR) is essential in cerebrovascular diseases, as exhausted CVR may enhance the risk of cerebral ischemic events. Transcranial Doppler (TCD) with a vasodilatory stimulus is currently used for CVR evaluation. Scanty data are available for Quantitative Magnetic Resonance Angiography (QMRA), which supplies higher spatial resolution and quantitative cerebral blood flow values. Aims of our pilot study were: (a) to assess safety and feasibility of CO 2 administration during QMRA, (b) evaluation of CVR under QMRA compared to TCD, and (c) quantitative evaluation of blood flow from the major intracranial arterial vessels both at rest and after CO 2 . CVR during 5% CO 2 air breathing was measured with TCD as a reference method and compared with QMRA. Fifteen healthy subjects (age 60.47 ± 2.24; male 11/15) were evaluated at rest and during CO 2 challenge. Feasibility and safety of QMRA under CO 2 were ensured in all subjects. CVR from middle cerebral artery territory was not statistically different between TCD and MRI (p > 0.05). Mean arterial pressure (MAP) and heart rate (HR) increased during QMRA and TCD (MAP p = 0.007 and p = 0.001; HR p = 0.043 and p = 0.068, respectively). Blood flow values from all intracranial vessels increased after CO 2 inhalation (p < 0.001). CO 2 administration during QMRA sessions is safe and feasible. Good correlation in terms of CVR was obtained comparing TCD and QMRA. Blood flow values significantly increased from all intracranial arterial vessels after CO 2 . Studies regarding CVR in physiopathological conditions might consider the utilization of QMRA both in routine clinical settings and in research projects

  7. Microbiological Quantitative Risk Assessment

    Science.gov (United States)

    Dominguez, Silvia; Schaffner, Donald W.

    The meat and poultry industry faces ongoing challenges due to the natural association of pathogens of concern (e.g., Salmonella, Campylobacter jejuni, Escherichia coli O157:H7) with a variety of domesticated food animals. In addition, pathogens such as Listeria monocytogenes pose a significant cross-contamination risk during further meat and poultry processing, distribution, and storage. Furthermore, the meat and poultry industries are constantly changing with the addition of new products, use of new raw materials, and targeting of new consumer populations, each of which may give rise to potential new risks. National and international regulations are increasingly using a “risk-based” approach to food safety (where the regulatory focus is driven by the magnitude of the risk), so risk assessment is becoming a valuable tool to systematically organize and evaluate the potential public health risk posed by food processing operations.

  8. Assessment of myocardial collateral circulation by intracoronary injection of radioactive microspheres and selective coronary angiography

    International Nuclear Information System (INIS)

    Uhde, W.

    1986-01-01

    In 46 patients selective coronary angiography was performed followed by selective coronary perfusion scintigraphy and a comparative assessment was made of the contralateral coronary collateral circulation. Intracoronary injection of radioactively marked imcrospheres resulted in the detection of microcirculatory processes and made it possible to evaluate the relative efficiency of coronary collaterals. This in turn meant a low-risk supplement and extension of the findings of coronary angiography. This holds particularly true for the area of the left ventricular myocardium. (author)

  9. Quantitative coronary plaque analysis predicts high-risk plaque morphology on coronary computed tomography angiography: results from the ROMICAT II trial.

    Science.gov (United States)

    Liu, Ting; Maurovich-Horvat, Pál; Mayrhofer, Thomas; Puchner, Stefan B; Lu, Michael T; Ghemigian, Khristine; Kitslaar, Pieter H; Broersen, Alexander; Pursnani, Amit; Hoffmann, Udo; Ferencik, Maros

    2018-02-01

    Semi-automated software can provide quantitative assessment of atherosclerotic plaques on coronary CT angiography (CTA). The relationship between established qualitative high-risk plaque features and quantitative plaque measurements has not been studied. We analyzed the association between quantitative plaque measurements and qualitative high-risk plaque features on coronary CTA. We included 260 patients with plaque who underwent coronary CTA in the Rule Out Myocardial Infarction/Ischemia Using Computer Assisted Tomography (ROMICAT) II trial. Quantitative plaque assessment and qualitative plaque characterization were performed on a per coronary segment basis. Quantitative coronary plaque measurements included plaque volume, plaque burden, remodeling index, and diameter stenosis. In qualitative analysis, high-risk plaque was present if positive remodeling, low CT attenuation plaque, napkin-ring sign or spotty calcium were detected. Univariable and multivariable logistic regression analyses were performed to assess the association between quantitative and qualitative high-risk plaque assessment. Among 888 segments with coronary plaque, high-risk plaque was present in 391 (44.0%) segments by qualitative analysis. In quantitative analysis, segments with high-risk plaque had higher total plaque volume, low CT attenuation plaque volume, plaque burden and remodeling index. Quantitatively assessed low CT attenuation plaque volume (odds ratio 1.12 per 1 mm 3 , 95% CI 1.04-1.21), positive remodeling (odds ratio 1.25 per 0.1, 95% CI 1.10-1.41) and plaque burden (odds ratio 1.53 per 0.1, 95% CI 1.08-2.16) were associated with high-risk plaque. Quantitative coronary plaque characteristics (low CT attenuation plaque volume, positive remodeling and plaque burden) measured by semi-automated software correlated with qualitative assessment of high-risk plaque features.

  10. Corrected coronary opacification decrease from coronary computed tomography angiography: Validation with quantitative 13N-ammonia positron emission tomography.

    Science.gov (United States)

    Benz, Dominik C; Gräni, Christoph; Ferro, Paola; Neumeier, Luis; Messerli, Michael; Possner, Mathias; Clerc, Olivier F; Gebhard, Catherine; Gaemperli, Oliver; Pazhenkottil, Aju P; Kaufmann, Philipp A; Buechel, Ronny R

    2017-07-06

    To assess the functional relevance of a coronary artery stenosis, corrected coronary opacification (CCO) decrease derived from coronary computed tomography angiography (CCTA) has been proposed. The present study aims at validating CCO decrease with quantitative 13N-ammonia positron emission tomography (PET) myocardial perfusion imaging (MPI). This retrospective study consists of 39 patients who underwent hybrid CCTA/PET-MPI. From CCTA, attenuation in the coronary lumen was measured before and after a stenosis and corrected to the aorta to calculate CCO and its decrease. Relative flow reserve (RFR) was calculated by dividing the stress myocardial blood flow (MBF) of a vessel territory subtended by a stenotic coronary by the stress MBF of the reference territories without stenoses. RFR was abnormal in 11 vessel territories (27%). CCO decrease yielded a sensitivity, specificity, negative predictive value, positive predictive value, and accuracy for prediction of an abnormal RFR of 73%, 70%, 88%, 47%, and 70%, respectively. CCTA-derived CCO decrease has moderate diagnostic accuracy to predict an abnormal RFR in PET-MPI. However, its high negative predictive value to rule out functional relevance of a given lesion may confer clinical implications in the diagnostic work-up of patients with a coronary stenosis.

  11. Post-mortem MR angiography: quantitative investigation and intravascular retention of perfusates in ex situ porcine hearts.

    Science.gov (United States)

    Webb, Bridgette; Widek, Thomas; Scheicher, Sylvia; Schwark, Thorsten; Stollberger, Rudolf

    2018-03-01

    As the implementation of minimally invasive imaging techniques in both forensic and pathological practice increases, research in this area focuses on addressing recognised diagnostic weaknesses of current approaches. Assessment of sudden cardiac death (SCD) can be considered one such area in which post-mortem imaging still shows diagnostic weaknesses. We hypothesise that magnetic resonance imaging (MRI) with an angiographic adjunct may improve the visualisation and interpretation of cardiac pathologies in a post-mortem setting. To systematically investigate this hypothesis, selected perfusates (paraffin oil, Gadovist®;-doped physiological solution and polyethylene glycol (PEG)) were injected into the left anterior descending (LAD) artery of ex situ porcine hearts to assess the visualisation of perfusates in MRI as well as their intravascular retention over 12 h. Morphological images were acquired and quantitative T 1 maps were generated from inversion recovery data. Visualisation of vascular structure and image quality were assessed using signal-to-noise and contrast-to-noise ratios. Intravascular retention was assessed both visually and statistically using a volume of interest (VOI) approach to analyse significant changes in signal intensity in and around the filled LAD artery, as well as changes in the longitudinal relaxation time (T 1 ) in adjacent myocardium. In addition to presenting possible mechanisms explaining perfusate extravasation given the increased permeability of post-mortem vessels, the potential diagnostic consequences of this phenomenon and the importance of contrast stability and extended intravascular retention are discussed. In light of our findings and these considerations, paraffin oil emerged as the preferred perfusate for use in post-mortem MR angiography.

  12. Quantitative blood flow measurements in the small animal cardiopulmonary system using digital subtraction angiography

    International Nuclear Information System (INIS)

    Lin Mingde; Marshall, Craig T.; Qi, Yi; Johnston, Samuel M.; Badea, Cristian T.; Piantadosi, Claude A.; Johnson, G. Allan

    2009-01-01

    Purpose: The use of preclinical rodent models of disease continues to grow because these models help elucidate pathogenic mechanisms and provide robust test beds for drug development. Among the major anatomic and physiologic indicators of disease progression and genetic or drug modification of responses are measurements of blood vessel caliber and flow. Moreover, cardiopulmonary blood flow is a critical indicator of gas exchange. Current methods of measuring cardiopulmonary blood flow suffer from some or all of the following limitations--they produce relative values, are limited to global measurements, do not provide vasculature visualization, are not able to measure acute changes, are invasive, or require euthanasia. Methods: In this study, high-spatial and high-temporal resolution x-ray digital subtraction angiography (DSA) was used to obtain vasculature visualization, quantitative blood flow in absolute metrics (ml/min instead of arbitrary units or velocity), and relative blood volume dynamics from discrete regions of interest on a pixel-by-pixel basis (100x100 μm 2 ). Results: A series of calibrations linked the DSA flow measurements to standard physiological measurement using thermodilution and Fick's method for cardiac output (CO), which in eight anesthetized Fischer-344 rats was found to be 37.0±5.1 ml/min. Phantom experiments were conducted to calibrate the radiographic density to vessel thickness, allowing a link of DSA cardiac output measurements to cardiopulmonary blood flow measurements in discrete regions of interest. The scaling factor linking relative DSA cardiac output measurements to the Fick's absolute measurements was found to be 18.90xCO DSA =CO Fick . Conclusions: This calibrated DSA approach allows repeated simultaneous visualization of vasculature and measurement of blood flow dynamics on a regional level in the living rat.

  13. Quantitative blood flow measurements in the small animal cardiopulmonary system using digital subtraction angiography

    Energy Technology Data Exchange (ETDEWEB)

    Lin Mingde; Marshall, Craig T.; Qi, Yi; Johnston, Samuel M.; Badea, Cristian T.; Piantadosi, Claude A.; Johnson, G. Allan [Department of Radiology, Center for In Vivo Microscopy and Department of Biomedical Engineering, Duke University Medical Center, Box 3302, Durham, North Carolina 27710 (United States); Division of Pulmonary and Critical Care Medicine and Center for Hyperbaric Medicine and Environmental Physiology, Duke University Medical Center, Box 3823, Durham, North Carolina 27710 (United States); Department of Radiology, Center for In Vivo Microscopy, Duke University Medical Center, Box 3302, Durham, North Carolina 27710 (United States); Department of Radiology, Center for In Vivo Microscopy and Department of Biomedical Engineering, Duke University Medical Center, Box 3302, Durham, North Carolina 27710 (United States); Department of Radiology, Center for In Vivo Microscopy, Duke University Medical Center, Box 3302, Durham, North Carolina 27710 (United States); Division of Pulmonary and Critical Care Medicine and Center for Hyperbaric Medicine and Environmental Physiology, Duke University Medical Center, Box 3823, Durham, North Carolina 27710 (United States); Department of Radiology, Center for In Vivo Microscopy and Department of Biomedical Engineering, Duke University Medical Center, Box 3302, Durham, North Carolina 27710 (United States)

    2009-11-15

    Purpose: The use of preclinical rodent models of disease continues to grow because these models help elucidate pathogenic mechanisms and provide robust test beds for drug development. Among the major anatomic and physiologic indicators of disease progression and genetic or drug modification of responses are measurements of blood vessel caliber and flow. Moreover, cardiopulmonary blood flow is a critical indicator of gas exchange. Current methods of measuring cardiopulmonary blood flow suffer from some or all of the following limitations--they produce relative values, are limited to global measurements, do not provide vasculature visualization, are not able to measure acute changes, are invasive, or require euthanasia. Methods: In this study, high-spatial and high-temporal resolution x-ray digital subtraction angiography (DSA) was used to obtain vasculature visualization, quantitative blood flow in absolute metrics (ml/min instead of arbitrary units or velocity), and relative blood volume dynamics from discrete regions of interest on a pixel-by-pixel basis (100x100 {mu}m{sup 2}). Results: A series of calibrations linked the DSA flow measurements to standard physiological measurement using thermodilution and Fick's method for cardiac output (CO), which in eight anesthetized Fischer-344 rats was found to be 37.0{+-}5.1 ml/min. Phantom experiments were conducted to calibrate the radiographic density to vessel thickness, allowing a link of DSA cardiac output measurements to cardiopulmonary blood flow measurements in discrete regions of interest. The scaling factor linking relative DSA cardiac output measurements to the Fick's absolute measurements was found to be 18.90xCO{sub DSA}=CO{sub Fick}. Conclusions: This calibrated DSA approach allows repeated simultaneous visualization of vasculature and measurement of blood flow dynamics on a regional level in the living rat.

  14. Quantitative coronary CT angiography: absolute lumen sizing rather than %stenosis predicts hemodynamically relevant stenosis

    Energy Technology Data Exchange (ETDEWEB)

    Plank, Fabian [Innsbruck Medical University, Department of Radiology, Innsbruck (Austria); Innsbruck Medical University, Department of Internal Medicine III - Cardiology, Innsbruck (Austria); Burghard, Philipp; Mayr, Agnes; Klauser, Andrea; Feuchtner, Gudrun [Innsbruck Medical University, Department of Radiology, Innsbruck (Austria); Friedrich, Guy; Dichtl, Wolfgang [Innsbruck Medical University, Department of Internal Medicine III - Cardiology, Innsbruck (Austria); Wolf, Florian [Vienna Medical University, Department of Cardiovascular and Interventional Radiology, Vienna (Austria)

    2016-11-15

    To identify the most accurate quantitative coronary stenosis parameter by CTA for prediction of functional significant coronary stenosis resulting in coronary revascularization. 160 consecutive patients were prospectively examined with CTA. Proximal coronary stenosis was quantified by minimal lumen area (MLA) and minimal lumen diameter (MLD), %area and %diameter stenosis. Lesion length (LL) was measured. The reference standard was invasive coronary angiography (ICA) (>70 % stenosis, FFR <0.8). 210 coronary segments were included (59 % positive). MLA of ≤1.8 mm{sup 2} was identified as the optimal cut-off (c = 0.97, p < 0.001; 95 % CI 0.94-0.99) (sensitivity 90.9 %, specificity 89.3 %) for prediction of functional-relevant stenosis (for MLA >2.1 mm{sup 2} sensitivity was 100 %). The optimal cut-off for MLD was 1.2 mm (c = 0.92; p < 0.001; 95 % CI 0.88-95) (sensitivity 90.9, specificity 85.2) while %area and %diameter stenosis were less accurate (c = 0.89; 95 % CI 0.84-93, c = 0.87; 95 % CI 0.82-92, respectively, with thresholds at 73 % and 61 % stenosis). Accuracy for LL was c = 0.74 (95 % CI 0.67-81), and for LL/MLA and LL/MLD ratio c = 0.90 and c = 0.84. MLA ≤1.8 mm{sup 2} and MLD ≤1.2 mm are the most accurate cut-offs for prediction of haemodynamically significant stenosis by ICA, with a higher accuracy than relative % stenosis. (orig.)

  15. Novel fluorescein angiography-based computer-aided algorithm for assessment of retinal vessel permeability.

    Directory of Open Access Journals (Sweden)

    Yonatan Serlin

    Full Text Available PURPOSE: To present a novel method for quantitative assessment of retinal vessel permeability using a fluorescein angiography-based computer algorithm. METHODS: Twenty-one subjects (13 with diabetic retinopathy, 8 healthy volunteers underwent fluorescein angiography (FA. Image pre-processing included removal of non-retinal and noisy images and registration to achieve spatial and temporal pixel-based analysis. Permeability was assessed for each pixel by computing intensity kinetics normalized to arterial values. A linear curve was fitted and the slope value was assigned, color-coded and displayed. The initial FA studies and the computed permeability maps were interpreted in a masked and randomized manner by three experienced ophthalmologists for statistical validation of diagnosis accuracy and efficacy. RESULTS: Permeability maps were successfully generated for all subjects. For healthy volunteers permeability values showed a normal distribution with a comparable range between subjects. Based on the mean cumulative histogram for the healthy population a threshold (99.5% for pathological permeability was determined. Clear differences were found between patients and healthy subjects in the number and spatial distribution of pixels with pathological vascular leakage. The computed maps improved the discrimination between patients and healthy subjects, achieved sensitivity and specificity of 0.974 and 0.833 respectively, and significantly improved the consensus among raters for the localization of pathological regions. CONCLUSION: The new algorithm allows quantification of retinal vessel permeability and provides objective, more sensitive and accurate evaluation than the present subjective clinical diagnosis. Future studies with a larger patients' cohort and different retinal pathologies are awaited to further validate this new approach and its role in diagnosis and treatment follow-up. Successful evaluation of vasculature permeability may be used for

  16. Acoustic Angiography: A New Imaging Modality for Assessing Microvasculature Architecture

    Directory of Open Access Journals (Sweden)

    Ryan C. Gessner

    2013-01-01

    Full Text Available The purpose of this paper is to provide the biomedical imaging community with details of a new high resolution contrast imaging approach referred to as “acoustic angiography.” Through the use of dual-frequency ultrasound transducer technology, images acquired with this approach possess both high resolution and a high contrast-to-tissue ratio, which enables the visualization of microvascular architecture without significant contribution from background tissues. Additionally, volumetric vessel-tissue integration can be visualized by using b-mode overlays acquired with the same probe. We present a brief technical overview of how the images are acquired, followed by several examples of images of both healthy and diseased tissue volumes. 3D images from alternate modalities often used in preclinical imaging, contrast-enhanced micro-CT and photoacoustics, are also included to provide a perspective on how acoustic angiography has qualitatively similar capabilities to these other techniques. These preliminary images provide visually compelling evidence to suggest that acoustic angiography may serve as a powerful new tool in preclinical and future clinical imaging.

  17. OCT-angiography: A qualitative and quantitative comparison of 4 OCT-A devices.

    Science.gov (United States)

    Munk, Marion R; Giannakaki-Zimmermann, Helena; Berger, Lieselotte; Huf, Wolfgang; Ebneter, Andreas; Wolf, Sebastian; Zinkernagel, Martin S

    2017-01-01

    To compare the quality of four OCT-angiography(OCT-A) modules. The retina of nineteen healthy volunteers were scanned with four OCT-devices (Topcon DRI-OCT Triton Swept-source OCT, Optovue RTVue-XR, a prototype Spectralis OCT2, Heidelberg-Engineering and Zeiss Cirrus 5000-HD-OCT). The device-software generated en-face OCT-A images of the superficial (SCP) and deep capillary plexuses (DCP) were evaluated and scored by 3 independent retinal imaging experts. The SCP vessel density was assessed using Angiotool-software. After the inter-grader reliability assessment, a consensus grading was performed and the modules were ranked based on their scoring. There was no significant difference in the vessel density among the modules (Zeiss 48.7±4%, Optovue 47.9±3%, Topcon 48.3±2%, Heidelberg 46.5±4%, p = 0.2). The numbers of discernible vessel-bifurcations differed significantly on each module (Zeiss 2±0.9 bifurcations, Optovue 2.5±1.2, Topcon 1.3±0.7 and Heidelberg 0.5±0.6, p≤0.001). The ranking of each module differed depending on the evaluated parameter. In the overall ranking, the Zeiss module was superior and in 90% better than the median (Bonferroni corrected p-value = 0.04). Optovue was better than the median in 60%, Topcon in 40% and Heidelberg module in 10%, however these differences were not statistically significant. Each of the four evaluated OCT-A modules had particular strengths, which differentiated it from their competitors.

  18. Integrated prediction of lesion-specific ischaemia from quantitative coronary CT angiography using machine learning: a multicentre study.

    Science.gov (United States)

    Dey, Damini; Gaur, Sara; Ovrehus, Kristian A; Slomka, Piotr J; Betancur, Julian; Goeller, Markus; Hell, Michaela M; Gransar, Heidi; Berman, Daniel S; Achenbach, Stephan; Botker, Hans Erik; Jensen, Jesper Moller; Lassen, Jens Flensted; Norgaard, Bjarne Linde

    2018-01-19

    We aimed to investigate if lesion-specific ischaemia by invasive fractional flow reserve (FFR) can be predicted by an integrated machine learning (ML) ischaemia risk score from quantitative plaque measures from coronary computed tomography angiography (CTA). In a multicentre trial of 254 patients, CTA and invasive coronary angiography were performed, with FFR in 484 vessels. CTA data sets were analysed by semi-automated software to quantify stenosis and non-calcified (NCP), low-density NCP (LD-NCP, difference (CDD, maximum difference in luminal attenuation per unit area) and plaque length. ML integration included automated feature selection and model building from quantitative CTA with a boosted ensemble algorithm, and tenfold stratified cross-validation. Eighty patients had ischaemia by FFR (FFR ≤ 0.80) in 100 vessels. Information gain for predicting ischaemia was highest for CDD (0.172), followed by LD-NCP (0.125), NCP (0.097), and total plaque volumes (0.092). ML exhibited higher area-under-the-curve (0.84) than individual CTA measures, including stenosis (0.76), LD-NCP volume (0.77), total plaque volume (0.74) and pre-test likelihood of coronary artery disease (CAD) (0.63); p quantitative plaque measures • Integrated ischaemia risk score showed higher prediction of ischaemia than standard approach • Contrast density difference had the highest information gain to identify lesion-specific ischaemia.

  19. Quantitative depth resolved microcirculation imaging with optical coherence tomography angiography (Part ΙΙ): Microvascular network imaging.

    Science.gov (United States)

    Gao, Wanrong

    2017-04-17

    In this work, we review the main phenomena that have been explored in OCT angiography to image the vessels of the microcirculation within living tissues with the emphasis on how the different processing algorithms were derived to circumvent specific limitations. Parameters are then discussed that can quantitatively describe the depth-resolved microvascular network for possible clinic diagnosis applications. Finally,future directions in continuing OCT development are discussed. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  20. Catheter Angiography

    Medline Plus

    Full Text Available ... News Physician Resources Professions Site Index A-Z Catheter Angiography Catheter angiography uses a catheter, x-ray ... are the limitations of Catheter Angiography? What is Catheter Angiography? Angiography is a minimally invasive medical test ...

  1. Assessment of acute myocarditis by cardiac magnetic resonance imaging: Comparison of qualitative and quantitative analysis methods.

    Science.gov (United States)

    Imbriaco, Massimo; Nappi, Carmela; Puglia, Marta; De Giorgi, Marco; Dell'Aversana, Serena; Cuocolo, Renato; Ponsiglione, Andrea; De Giorgi, Igino; Polito, Maria Vincenza; Klain, Michele; Piscione, Federico; Pace, Leonardo; Cuocolo, Alberto

    2017-10-26

    To compare cardiac magnetic resonance (CMR) qualitative and quantitative analysis methods for the noninvasive assessment of myocardial inflammation in patients with suspected acute myocarditis (AM). A total of 61 patients with suspected AM underwent coronary angiography and CMR. Qualitative analysis was performed applying Lake-Louise Criteria (LLC), followed by quantitative analysis based on the evaluation of edema ratio (ER) and global relative enhancement (RE). Diagnostic performance was assessed for each method by measuring the area under the curves (AUC) of the receiver operating characteristic analyses. The final diagnosis of AM was based on symptoms and signs suggestive of cardiac disease, evidence of myocardial injury as defined by electrocardiogram changes, elevated troponin I, exclusion of coronary artery disease by coronary angiography, and clinical and echocardiographic follow-up at 3 months after admission to the chest pain unit. In all patients, coronary angiography did not show significant coronary artery stenosis. Troponin I levels and creatine kinase were higher in patients with AM compared to those without (both P qualitative (T2-weighted STIR 0.92, EGE 0.87 and LGE 0.88) and quantitative (ER 0.89 and global RE 0.80) analyses were also similar. Qualitative and quantitative CMR analysis methods show similar diagnostic accuracy for the diagnosis of AM. These findings suggest that a simplified approach using a shortened CMR protocol including only T2-weighted STIR sequences might be useful to rule out AM in patients with acute coronary syndrome and normal coronary angiography.

  2. A comparison between magnetic resonance angiography at 3 teslas (time-of-flight and contrast-enhanced) and flat-panel digital subtraction angiography in the assessment of embolized brain aneurysms

    Energy Technology Data Exchange (ETDEWEB)

    Nakiri, Guilherme S.; Santos, Antonio C.; Abud, Thiago G.; Abud, Daniel G., E-mail: gsnakiri@yahoo.com.b [University of Sao Paulo (USP), Ribeirao Preto, SP (Brazil). Medical School. Div. of Radiology; Aragon, Davi C. [University of Sao Paulo (USP), Ribeirao Preto, SP (Brazil). Medical School. Div. of Statistics; Colli, Benedicto O. [University of Sao Paulo (USP), Ribeirao Preto, SP (Brazil). Medical School. Div. of Neurosurgery

    2011-07-01

    Purpose: to compare the time-of-flight and contrast-enhanced- magnetic resonance angiography techniques in a 3 Tesla magnetic resonance unit with digital subtraction angiography with the latest flat-panel technology and 3D reconstruction in the evaluation of embolized cerebral aneurysms. Introduction: many embolized aneurysms are subject to a recurrence of intra-aneurysmal filling. Traditionally, imaging surveillance of coiled aneurysms has consisted of repeated digital subtraction angiography. However, this method has a small but significant risk of neurological complications, and many authors have advocated the use of noninvasive imaging methods for the surveillance of embolized aneurysms. Methods: forty-three aneurysms in 30 patients were studied consecutively between November 2009 and May 2010. Two interventional neuro radiologists rated the time-of-flight-magnetic resonance angiography, the contrast enhanced-magnetic resonance angiography, and finally the digital subtraction angiography, first independently and then in consensus. The status of aneurysm occlusion was assessed according to the Raymond scale, which indicates the level of recanalization according to degrees: Class 1: excluded aneurysm; Class 2: persistence of a residual neck; Class 3: persistence of a residual aneurysm. The agreement among the analyses was assessed by applying the Kappa statistic. Results: inter-observer agreement was excellent for both methods (K = 0.93; 95 % CI: 0.84-1). Inter-technical agreement was almost perfect between time-of-flight-magnetic resonance angiography and digital subtraction angiography (K = 0.98; 95 % CI: 0.93-1) and between time-of-flight-magnetic resonance angiography and contrast enhanced-magnetic resonance angiography (K = 0.98; 95% CI: 0.93-1). Disagreement occurred in only one case (2.3%), which was classified as Class I by time-of-flight-magnetic resonance angiography and Class II by digital subtraction angiography. The agreement between contrast

  3. A comparison between magnetic resonance angiography at 3 teslas (time-of-flight and contrast-enhanced and flat-panel digital subtraction angiography in the assessment of embolized brain aneurysms

    Directory of Open Access Journals (Sweden)

    Guilherme S. Nakiri

    2011-01-01

    Full Text Available PURPOSE: To compare the time-of-flight and contrast-enhanced- magnetic resonance angiography techniques in a 3 Tesla magnetic resonance unit with digital subtraction angiography with the latest flat-panel technology and 3D reconstruction in the evaluation of embolized cerebral aneurysms. INTRODUCTION: Many embolized aneurysms are subject to a recurrence of intra-aneurismal filling. Traditionally, imaging surveillance of coiled aneurysms has consisted of repeated digital subtraction angiography. However, this method has a small but significant risk of neurological complications, and many authors have advocated the use of noninvasive imaging methods for the surveillance of embolized aneurysms. METHODS: Forty-three aneurysms in 30 patients were studied consecutively between November 2009 and May 2010. Two interventional neuroradiologists rated the time-of-flight-magnetic resonance angiography, the contrast-enhanced-magnetic resonance angiography, and finally the digital subtraction angiography, first independently and then in consensus. The status of aneurysm occlusion was assessed according to the Raymond scale, which indicates the level of recanalization according to degrees: Class 1: excluded aneurysm; Class 2: persistence of a residual neck; Class 3: persistence of a residual aneurysm. The agreement among the analyses was assessed by applying the Kappa statistic. RESULTS: Inter-observer agreement was excellent for both methods (K = 0.93; 95 % CI: 0.84-1. Inter-technical agreement was almost perfect between time-of-flight-magnetic resonance angiography and digital subtraction angiography (K = 0.98; 95 % CI: 0.93-1 and between time-of-flight-magnetic resonance angiography and contrast-enhanced-magnetic resonance angiography (K = 0.98; 95% CI: 0.93-1. Disagreement occurred in only one case (2.3%, which was classified as Class I by time-of-flight-magnetic resonance angiography and Class II by digital subtraction angiography. The agreement between

  4. A quantitative framework for assessing ecological resilience

    Science.gov (United States)

    Quantitative approaches to measure and assess resilience are needed to bridge gaps between science, policy, and management. In this paper, we suggest a quantitative framework for assessing ecological resilience. Ecological resilience as an emergent ecosystem phenomenon can be dec...

  5. The choroidal circulation assessed by laser-targeted angiography.

    Science.gov (United States)

    Hirata, Yuya; Nishiwaki, Hirokazu

    2006-03-01

    The choroid plays an important role in supplying nutrients to and removing waste products from the outer region of the retina. Abnormal choroidal blood flow can disrupt normal retinal function and lead to alterations in visual function. Visualization of the choriocapillaris in vivo is a great challenge to understanding its normal physiology and involvement in the disease process. Laser-targeted angiography (LTA) is a relatively new method used to visualize and analyze the choroidal circulation. Carboxyfluorescein (CF), encapsulated in heat-sensitive liposomes, is released locally in the choroid through the application of a heat beam provided by an infrared laser. Video angiograms are generated with excitation illumination provided by an argon laser. Obtained images are highly selective to the choriocapillaris and are sharply contrasted against underlying and overlying structures. The images can be obtained repetitively, during which period the circulating liposome concentration is sufficient to generate adequate angiograms. These high-quality images have revealed three distinct phases (filling, plateau, and draining) of the choriocapillaris. In the plateau phase, a cluster of lobules fed by a common arteriole has been uniformly illuminated. This defined cluster area does not change in size while an infrared laser is continuously applied to the same spot, which demonstrates that each cluster is functionally independent and no physiological communication exists between them. Only in posterior regions do the angiograms demonstrate during the filling and draining phases that each lobule is filled from a central spot and drained along a peripheral ring, showing honeycomb flow patterns. The regional differences in choriocapillaris flow patterns revealed by LTA suggests that the choriocapillaris provides a more highly efficient system of outflow in posterior regions than in peripheral regions. LTA is useful in analyzing choroidal circulation in vivo and has the potential

  6. Catheter Angiography

    Medline Plus

    Full Text Available ... Angiography is performed using: x-rays with catheters computed tomography (CT) magnetic resonance imaging (MRI) In catheter angiography, ... a tumor; this is called superselective angiography. Unlike computed tomography (CT) or magnetic resonance (MR) angiography , use of ...

  7. Re-examining minimal luminal diameter relocation and quantitative coronary angiography - Intravascular ultrasound correlations in stented saphenous vein grafts: Methodological insights from the randomised RRISC trial

    NARCIS (Netherlands)

    O. Semeraro (Oscar); P. Agostoni (Pierfrancesco); S. Verheye (Stefan); G.J.J. van Langenhove (Glenn); P.A. van den Heuvel (Paul); C. Convens (Carl); F. van den Branden (Frank); N. Bruining (Nico); P. Vermeersch (Paul)

    2009-01-01

    textabstractAims: Angiographic parameters (such as late luminal loss) are common endpoints in drug-eluting stent trials, but their correlation with the neointimal process and their reliability in predicting restenosis are debated. Methods and results: Using quantitative coronary angiography (QCA)

  8. Assessment of right ventricular afterload in mitral valve diseases with radionuclide angiography

    International Nuclear Information System (INIS)

    Shimizu, Mitsuharu; Nakagawa, Tomio; Kohno, Yoshihiro; Kuroda, Masahiro; Takeda, Yoshihiro; Hiraki, Yoshio; Nagaya, Isao; Senoh, Yoshimasa; Teramoto, Shigeru

    1991-01-01

    Right ventricular function at rest and during exercise was studied in 33 patients with mitral valve disease by equilibrium gated radionuclide angiography using 99m Tc in vivo labeled red blood cells. Radionuclide measurements of right ventricular ejection fraction (RVEF) were correlated with mean pulmonary arterial pressure (mPAP). RVEF decreased significantly with exercise. There was no significant correlation between RVEF at rest and mPAP. However, mPAP showed significant negative correlation with RVEF during exercise and with the changes of RVEF from rest to exercise. It is concluded that RVEF during exercise in mitral valve disease is affected by right ventricular afterload, and the measurements of RVEF at rest and during exercise by equilibrium gated radionuclide angiography is useful to assess right ventricular afterload. (author)

  9. Optical coherence tomography angiography retinal vascular network assessment in multiple sclerosis.

    Science.gov (United States)

    Lanzillo, Roberta; Cennamo, Gilda; Criscuolo, Chiara; Carotenuto, Antonio; Velotti, Nunzio; Sparnelli, Federica; Cianflone, Alessandra; Moccia, Marcello; Brescia Morra, Vincenzo

    2017-09-01

    Optical coherence tomography (OCT) angiography is a new method to assess the density of the vascular networks. Vascular abnormalities are considered involved in multiple sclerosis (MS) pathology. To assess the presence of vascular abnormalities in MS and to evaluate their correlation to disease features. A total of 50 MS patients with and without history of optic neuritis (ON) and 46 healthy subjects were included. All underwent spectral domain (SD)-OCT and OCT angiography. Clinical history, Expanded Disability Status Scale (EDSS), Multiple Sclerosis Severity Score (MSSS) and disease duration were collected. Angio-OCT showed a vessel density reduction in eyes of MS patients when compared to controls. A statistically significant reduction in all SD-OCT and OCT angiography parameters was noticed both in eyes with and without ON when compared with control eyes. We found an inverse correlation between SD-OCT parameters and MSSS ( p = 0.003) and between vessel density parameters and EDSS ( p = 0.007). We report a vessel density reduction in retina of MS patients. We highlight the clinical correlation between vessel density and EDSS, suggesting that angio-OCT could be a good marker of disease and of disability in MS.

  10. Elimination of variable vasomotor tone in studies with repeated quantitative coronary angiography.

    Science.gov (United States)

    Jost, S; Rafflenbeul, W; Reil, G H; Trappe, H J; Gulba, D; Hecker, H; Gerhardt, U; Knop, I

    1990-01-01

    In quantitative coronary angiographic studies, unintentional changes of coronary vasomotor tone may have a significant influence on the coronary artery diameters, thereby increasing the variability in the measurements. To obtain objective data on these measurement variabilities, two protocols were designed to assess the influences of ionic and nonionic radiographic contrast media on the mean diameters of angiographically normal coronary arteries. The vessel sizes were determined with the CAAS using automated edge detection techniques. In 21 patients (study no. I), coronary angiograms were taken in identical angiographic projections before (control), and immediately following several (at average 7) subsequent diagnostic dye injections administered over a period of about 7 min. The ionic contrast agent diatrizoate 76% induced a coronary dilation of 19 +/- 7% (mean +/- s.d., p less than 0.001; n = 10); the nonionic agent iopromide 370 increased the coronary artery diameters by only 6 +/- 4% (p less than 0.01; n = 11). In another 11 patients (study no. II) coronary angiograms were obtained using the nonionic contrast medium iopamidol 300 at 5, 8, 10 and 11 min after the control acquisition; this protocol was repeated in the same patients with diatrizoate 76%. With iopamidol, coronary diameter changes were not significant at any time; with diatrizoate, however, coronary dilation was measured at 10 min (2 +/- 2%; p less than 0.01) and at 11 min (10 +/- 3%; p less than 0.001). In a third study it was tested, whether standardization of coronary vasomotor tone (e.g. in coronary angiographic follow-up studies) is possible by the induction of a reproducible maximum coronary dilation with nitrocompounds. In 12 patients, the mean diameters of angiographically normal coronary segments were analyzed before and at various times after i.v. administration (over 4 min) of 0.025 mg SIN-1/kg bodyweight. Coronary dilation was maximal at 10 or 15 min after the onset of the SIN-1-infusion

  11. Need for Quantitative Measurement Methods for Posterior Uveitis: Comparison of Dual FA/ICGA Angiography, EDI-OCT Choroidal Thickness and SUN Vitreous Haze Evaluation in Stromal Choroiditis.

    Science.gov (United States)

    Fabro, Filippo; Herbort, Carl P

    2018-04-01

    Quantitative methods for posterior uveitis are necessary for precise appraisal and follow-up of inflammation in practice and in clinical trials. The aim of this study was to assess fluorescein angiography (FA), indocanine green angiography (ICGA), and enhanced depth imaging optical coherence tomography choroidal thickness (EDI-OCT CT) in two stromal choroiditis entities, birdshot retinochoroiditis (BRC), and Vogt-Koyanagi-Harada disease (VKH), as well as to determine (1) disease patterns, (2) respective response to therapy, and (3) their potential utility in clinical trials in comparison to vitreous haze, the present standard outcome used in clinical trials. This retrospective study included newly diagnosed patients with BRC and VKH, seen at the Centre for Ophthalmic Specialized Care, Lausanne, Switzerland. Angiographic signs were quantified using an established dual FA/ICGA scoring system for uveitis at presentation and on follow-up. FA/ICGA score ratios were compared between diseases to determine disease patterns. EDI-OCT CT was determined using a spectral domain instrument. Vitreous haze was determined using the SUN (Standardization of Uveitis Nomenclature) method. Among 1872 uveitis patients seen from 1995 to 2016, 8 newly diagnosed BRC patients (16 eyes) and 6 newly diagnosed VKH patients (12 eyes) had sufficient data for study inclusion. Patients with BRC and VKH at initial onset had mean FA scores of 16.1 ± 7.0 vs. 4.6 ± 2.1 (p measurement of inflammation at onset and upon follow-up. EDI-OCT CT responded to therapy in both diseases but was found to be of limited use in this early/subacute disease phase because it lacked sensitivity to detect subclinical recurrences and was therefore only useful for long-term follow-up. Vitreous haze was low in both entities and thus useless as an inflammatory parameter. Georg Thieme Verlag KG Stuttgart · New York.

  12. Evaluation of Coronary Artery Stenosis by Quantitative Flow Ratio During Invasive Coronary Angiography: The WIFI II Study (Wire-Free Functional Imaging II).

    Science.gov (United States)

    Westra, Jelmer; Tu, Shengxian; Winther, Simon; Nissen, Louise; Vestergaard, Mai-Britt; Andersen, Birgitte Krogsgaard; Holck, Emil Nielsen; Fox Maule, Camilla; Johansen, Jane Kirk; Andreasen, Lene Nyhus; Simonsen, Jo Krogsgaard; Zhang, Yimin; Kristensen, Steen Dalby; Maeng, Michael; Kaltoft, Anne; Terkelsen, Christian Juhl; Krusell, Lars Romer; Jakobsen, Lars; Reiber, Johan H C; Lassen, Jens Flensted; Bøttcher, Morten; Bøtker, Hans Erik; Christiansen, Evald Høj; Holm, Niels Ramsing

    2018-03-01

    Quantitative flow ratio (QFR) is a novel diagnostic modality for functional testing of coronary artery stenosis without the use of pressure wires and induction of hyperemia. QFR is based on computation of standard invasive coronary angiographic imaging. The purpose of WIFI II (Wire-Free Functional Imaging II) was to evaluate the feasibility and diagnostic performance of QFR in unselected consecutive patients. WIFI II was a predefined substudy to the Dan-NICAD study (Danish Study of Non-Invasive Diagnostic Testing in Coronary Artery Disease), referring 362 consecutive patients with suspected coronary artery disease on coronary computed tomographic angiography for diagnostic invasive coronary angiography. Fractional flow reserve (FFR) was measured in all segments with 30% to 90% diameter stenosis. Blinded observers calculated QFR (Medis Medical Imaging bv, The Netherlands) for comparison with FFR. FFR was measured in 292 lesions from 191 patients. Ten (5%) and 9 patients (5%) were excluded because of FFR and angiographic core laboratory criteria, respectively. QFR was successfully computed in 240 out of 255 lesions (94%) with a mean diameter stenosis of 50±12%. Mean difference between FFR and QFR was 0.01±0.08. QFR correctly classified 83% of the lesions using FFR with cutoff at 0.80 as reference standard. The area under the receiver operating characteristic curve was 0.86 (95% confidence interval, 0.81-0.91) with a sensitivity, specificity, negative predictive value, and positive predictive value of 77%, 86%, 75%, and 87%, respectively. A QFR-FFR hybrid approach based on the present results enables wire-free and adenosine-free procedures in 68% of cases. Functional lesion evaluation by QFR assessment showed good agreement and diagnostic accuracy compared with FFR. Studies comparing clinical outcome after QFR- and FFR-based diagnostic strategies are required. URL: https://www.clinicaltrials.gov. Unique identifier: NCT02264717. © 2018 The Authors.

  13. Prospectively electrocardiogram-triggered high-pitch spiral acquisition coronary computed tomography angiography for assessment of biodegradable vascular scaffold expansion: Comparison with optical coherence tomography

    Energy Technology Data Exchange (ETDEWEB)

    D’Alfonso, Maria Grazia [Interventional Cardiology Unit University Of Florence, Heart and Vessels department, AOU Careggi, Florence (Italy); Mattesini, Alessio, E-mail: amattesini@gmail.com [Interventional Cardiology Unit University Of Florence, Heart and Vessels department, AOU Careggi, Florence (Italy); Meucci, Francesco [Interventional Cardiology Unit University Of Florence, Heart and Vessels department, AOU Careggi, Florence (Italy); Acquafresca, Manlio [Radiology Unit 4, Radiology Department, AOU Careggi, Florence (Italy); Gensini, Gian Franco; Valente, Serafina [Interventional Cardiology Unit University Of Florence, Heart and Vessels department, AOU Careggi, Florence (Italy)

    2014-11-15

    BVS polymeric struts are transparent to the light so that the vessel wall contour can be easily visualized using optical coherence tomography (OCT). Therefore OCT represents a unique tool for both the evaluation of the resorption process and for the assessment of acute BVS mechanical failure. Similarly, the metal-free struts allow unrestricted coronary computed tomography angiography (CCTA), thus this non invasive method might become the gold standard for a non invasive assessment of BVS. In this case we show the ability of CCTA, performed with a low X-Ray dose, to provide a good evaluation of scaffold expansion. The quantitative measurements were in agreement with those obtained with OCT.

  14. Online Angiography Image-Based FFR Assessment During Coronary Catheterization: A Single-Center Study.

    Science.gov (United States)

    Kornowski, Ran; Vaknin-Assa, Hana; Assali, Abid; Greenberg, Gabriel; Valtzer, Orna; Lavi, Ifat

    2018-03-15

    To assess the diagnostic performance of angiography-derived fractional flow reserve (FFRangio) measurements in patients with stable coronary artery disease when used online in the catheterization laboratory during routine coronary angiography. FFR, an index of the hemodynamic severity of coronary stenosis, is derived from invasive measurements using a pressure-monitoring guidewire and hyperemic stimulus. While FFR is the gold standard, it remains under-utilized. FFRangio may have several advantages owing to the reduced operator time, no wire-related or procedural complications, and no need for administration of vasodilators. FFRangio is a novel technology that uses a patient's hemodynamic data and routine angiograms to generate FFR values at each point along the coronary tree. We present the online application of the system where FFRangio was successfully used in the catheterization laboratory during routine coronary angiography and compared to invasive FFR. Fifty-three patients (79% men) and 60 coronary lesions were analyzed. Values derived using FFRangio ranged from 0.58-0.96 and correlated closely (Pearson's correlation coefficient, r=0.91; Psystem. In this single-center experience, FFRangio values showed high correlation rates to invasive FFR.

  15. CT and CT angiography in massive haemoptysis with emphasis on pre-embolization assessment

    International Nuclear Information System (INIS)

    Noe, G.D.; Jaffe, S.M.; Molan, M.P.

    2011-01-01

    Massive haemoptysis is a respiratory emergency. Computed tomography angiography (CTA) can play a crucial role in assessing the cause and origin of the haemoptysis and directing the interventional radiologist prior to treatment. The bronchial arterial supply and to a lesser extent the non-bronchial systemic arterial supply are responsible for the majority of cases of massive haemoptysis, but uncommon causes of massive haemoptysis should be considered to avoid misdiagnosis and delayed treatment. Failure to assess the imaging appropriately prior to endovascular treatment may result in early recurrent massive haemoptysis or patient death.

  16. Value of Quantitative Collateral Scoring on CT Angiography in Patients with Acute Ischemic Stroke.

    Science.gov (United States)

    Boers, A M M; Sales Barros, R; Jansen, I G H; Berkhemer, O A; Beenen, L F M; Menon, B K; Dippel, D W J; van der Lugt, A; van Zwam, W H; Roos, Y B W E M; van Oostenbrugge, R J; Slump, C H; Majoie, C B L M; Marquering, H A

    2018-04-19

    Many studies have emphasized the relevance of collateral flow in patients presenting with acute ischemic stroke. Our aim was to evaluate the relationship of the quantitative collateral score on baseline CTA with the outcome of patients with acute ischemic stroke and test whether the timing of the CTA acquisition influences this relationship. From the Multicenter Randomized Clinical Trial of Endovascular Treatment of Acute Ischemic Stroke in the Netherlands (MR CLEAN) data base, all baseline thin-slice CTA images of patients with acute ischemic stroke with intracranial large-vessel occlusion were retrospectively collected. The quantitative collateral score was calculated as the ratio of the vascular appearance of both hemispheres and was compared with the visual collateral score. Primary outcomes were 90-day mRS score and follow-up infarct volume. The relation with outcome and the association with treatment effect were estimated. The influence of the CTA acquisition phase on the relation of collateral scores with outcome was determined. A total of 442 patients were included. The quantitative collateral score strongly correlated with the visual collateral score (ρ = 0.75) and was an independent predictor of mRS (adjusted odds ratio = 0.81; 95% CI, .77-.86) and follow-up infarct volume (exponent β = 0.88; P collateral score showed areas under the curve of 0.71 and 0.69 for predicting functional independence (mRS 0-2) and follow-up infarct volume of >90 mL, respectively. We found significant interaction of the quantitative collateral score with the endovascular therapy effect in unadjusted analysis on the full ordinal mRS scale ( P = .048) and on functional independence ( P = .049). Modification of the quantitative collateral score by acquisition phase on outcome was significant (mRS: P = .004; follow-up infarct volume: P collateral scoring in patients with acute ischemic stroke is a reliable and user-independent measure of the collateral capacity on baseline CTA and

  17. CT Coronary Angiography vs. Coronary Artery Calcium Scoring for the Occupational Assessment of Military Aircrew.

    Science.gov (United States)

    Parsons, Iain; Pavitt, Chris; Chamley, Rebecca; d'Arcy, Jo; Nicol, Ed

    2017-02-01

    To ensure flight safety military aircrew undergo regular clinical and occupational assessment. Coronary artery calcium scoring (CACS) has been established as an imaging modality to noninvasively assess coronary artery disease (CAD). CT coronary angiography (CTCA) potentially offers a more accurate assessment of CAD, but has not been formally assessed in military aircrew. This retrospective cohort study is designed to compare the theoretical differences in downstream investigations and occupational outcomes in aircrew with suspected CAD comparing CTCA with existing CACS pathways. A 2-yr retrospective cohort study of consecutive UK military patients who underwent a CTCA and CACS was undertaken. Patient demographics, CTCA and CACS results, and initial and final occupational restrictions were analyzed comparing current UK, Canadian, and U.S. pathways. There were 44 patients who underwent CACS and CTCA. The commonest indication for a CTCA was a positive exercise ECG. Increasing CACS, stenosis severity, and stenosis burden were associated with significantly greater likelihood of occupational restriction (P = Nicol E. CT coronary angiography vs. coronary artery calcium scoring for the occupational assessment of military aircrew. Aerosp Med Hum Perform. 2017; 88(2):76-81.

  18. Qualitative and Quantitative Coronary Angiography in patients with Acute Coronary Syndrome (ACS

    Directory of Open Access Journals (Sweden)

    Ahmed H.H. El-Adawey

    2012-07-01

    Conclusion: The qualitative angiographic assessment represents an essential tool in the evaluation and risk stratification of patients with ACS, through the demonstration of the presence of thrombus and lumen irregularity that correlated more with ACS than the other studded criteria. In addition, QCA although added accurate assessment of the degree of luminal narrowing, thus helping in assessment of the severity of the disease.

  19. Catheter Angiography

    Medline Plus

    Full Text Available ... using: x-rays with catheters computed tomography (CT) magnetic resonance imaging (MRI) In catheter angiography, a thin ... called superselective angiography. Unlike computed tomography (CT) or magnetic resonance (MR) angiography , use of a catheter makes ...

  20. Catheter Angiography

    Medline Plus

    Full Text Available ... x-rays with catheters computed tomography (CT) magnetic resonance imaging (MRI) In catheter angiography, a thin plastic ... superselective angiography. Unlike computed tomography (CT) or magnetic resonance (MR) angiography , use of a catheter makes it ...

  1. Catheter Angiography

    Medline Plus

    Full Text Available ... risks? What are the limitations of Catheter Angiography? What is Catheter Angiography? Angiography is a minimally invasive ... of ionizing radiation ( x-rays ). top of page What are some common uses of the procedure? Catheter ...

  2. Quantitative changes in flow density in patients with adult-onset foveomacular vitelliform dystrophy: an OCT angiography study.

    Science.gov (United States)

    Treder, Maximilian; Lauermann, Jost Lennart; Alnawaiseh, Maged; Heiduschka, Peter; Eter, Nicole

    2018-01-01

    To quantitatively compare the flow density, the retinal thickness, and the area of the foveal avascular zone (FAZ) between patients with adult-onset foveomacular vitelliform dystrophy (AOFVD) and a healthy controls. Thirteen eyes (eight patients) with AOFVD and 13 matched eyes (13 patients) without any ocular pathology were included in this study. A 6 × 6 mm optical coherence tomography angiography (OCTA) scan was performed for every included eye. The flow density (superficial retinal vascular layer, deep retinal vascular layer and choriocapillary layer), retinal thickness and FAZ (superficial retinal vascular layer and deep retinal vascular layer) were subsequently analyzed. The mean flow density was decreased in the AOFVD patients in all measured vascular layers. The difference from the control group was statistically significant in the parafoveal sector of the deep retinal vascular layer (P = 0.02), and a clear trend was found in the superficial retinal vascular layer (P = 0.05). Both groups had comparable FAZs in the superficial and deep retinal vascular layers. The retinal thickness values were higher in the fovea (P = 0.840) and lower in the parafoveal sectors (P = 0.125). The difference was significant in the superior parafoveal sector (P = 0.034). Flow densities as measured by OCTA are decreased in the superficial retinal vascular layer and the deep retinal vascular layer in patients with AOFVD. These findings could be helpful for diagnosing and understanding the pathogenesis of this disease.

  3. Evaluation of Coronary Artery Stenosis by Quantitative Flow Ratio During Invasive Coronary Angiography

    DEFF Research Database (Denmark)

    Westra, Jelmer; Tu, Shengxian; Winther, Simon

    2018-01-01

    BACKGROUND: Quantitative flow ratio (QFR) is a novel diagnostic modality for functional testing of coronary artery stenosis without the use of pressure wires and induction of hyperemia. QFR is based on computation of standard invasive coronary angiographic imaging. The purpose of WIFI II (Wire......-Free Functional Imaging II) was to evaluate the feasibility and diagnostic performance of QFR in unselected consecutive patients. METHODS AND RESULTS: WIFI II was a predefined substudy to the Dan-NICAD study (Danish Study of Non-Invasive Diagnostic Testing in Coronary Artery Disease), referring 362 consecutive...

  4. Comparison of contrast and noncontrast magnetic resonance angiography for quantitative analysis of thoracic arteries in young patients with congenital heart defects

    Directory of Open Access Journals (Sweden)

    Pasqua Alessia

    2011-01-01

    Full Text Available Background : Contrast MRA (C-MRA is the standard for quantitative analysis of thoracic vessels. We evaluated a noncontrast MRA (NC-MRA sequence (3-D EKG and navigator-gated SSFP for quantitative evaluation of the thoracic aorta and branch pulmonary arteries in young patients with congenital heart disease. Objective : To compare contrast and noncontrast magnetic resonance angiography for quantitative analysis of thoracic arteries in young patients with congenital heart defects. Methods : Measurements of thoracic aorta and branch pulmonary arteries were obtained from C-MRA and NC-MRA images in 51 patients, ages 2-35 years. Vessel diameters were compared using correlation and Bland-Altman analysis. Interobserver variability was assessed using percent variation. Results : C-MRA and NC-MRA measurements were highly correlated (r = 0.91-0.98 except for the right pulmonary artery (r = 0.74, 0.78. Agreement of measurements was excellent (mean difference -0.07 to -0.53 mm; mean % difference -1.8 to -4.9% except for the right pulmonary artery which was less good (mean difference 0.73, -1.38 mm; -3, -10%. Interobserver variability ranged from 5% to 8% for aortic and from 10% to 16% for pulmonary artery measures. The worse agreement and greater variability of the pulmonary artery measures appears due to difficulty standardizing the measurements in patients with abnormal and irregular vessels. Conclusion : These data indicate that C-MRA and NC-MRA measures are comparable and could be used interchangeably, avoiding administration of contrast in selected patients.

  5. Environmental probabilistic quantitative assessment methodologies

    Science.gov (United States)

    Crovelli, R.A.

    1995-01-01

    In this paper, four petroleum resource assessment methodologies are presented as possible pollution assessment methodologies, even though petroleum as a resource is desirable, whereas pollution is undesirable. A methodology is defined in this paper to consist of a probability model and a probabilistic method, where the method is used to solve the model. The following four basic types of probability models are considered: 1) direct assessment, 2) accumulation size, 3) volumetric yield, and 4) reservoir engineering. Three of the four petroleum resource assessment methodologies were written as microcomputer systems, viz. TRIAGG for direct assessment, APRAS for accumulation size, and FASPU for reservoir engineering. A fourth microcomputer system termed PROBDIST supports the three assessment systems. The three assessment systems have different probability models but the same type of probabilistic method. The type of advantages of the analytic method are in computational speed and flexibility, making it ideal for a microcomputer. -from Author

  6. Relationship Between Quantitative Adverse Plaque Features From Coronary Computed Tomography Angiography and Downstream Impaired Myocardial Flow Reserve by 13N-Ammonia Positron Emission Tomography: A Pilot Study.

    Science.gov (United States)

    Dey, Damini; Diaz Zamudio, Mariana; Schuhbaeck, Annika; Juarez Orozco, Luis Eduardo; Otaki, Yuka; Gransar, Heidi; Li, Debiao; Germano, Guido; Achenbach, Stephan; Berman, Daniel S; Meave, Aloha; Alexanderson, Erick; Slomka, Piotr J

    2015-10-01

    We investigated the relationship of quantitative plaque features from coronary computed tomography (CT) angiography and coronary vascular dysfunction by impaired myocardial flow reserve (MFR) by (13)N-Ammonia positron emission tomography (PET). Fifty-one patients (32 men, 62.4±9.5 years) underwent combined rest-stress (13)N-ammonia PET and CT angiography scans by hybrid PET/CT. Regional MFR was measured from PET. From CT angiography, 153 arteries were evaluated by semiautomated software, computing arterial noncalcified plaque (NCP), low-density NCP (NCP<30 HU), calcified and total plaque volumes, and corresponding plaque burden (plaque volumex100%/vessel volume), stenosis, remodeling index, contrast density difference (maximum difference in luminal attenuation per unit area in the lesion), and plaque length. Quantitative stenosis, plaque burden, and myocardial mass were combined by boosted ensemble machine-learning algorithm into a composite risk score to predict impaired MFR (MFR≤2.0) by PET in each artery. Nineteen patients had impaired regional MFR in at least 1 territory (41/153 vessels). Patients with impaired regional MFR had higher arterial NCP (32.4% versus 17.2%), low-density NCP (7% versus 4%), and total plaque burden (37% versus 19.3%, P<0.02). In multivariable analysis with 10-fold cross-validation, NCP burden was the most significant predictor of impaired MFR (odds ratio, 1.35; P=0.021 for all). For prediction of impaired MFR with 10-fold cross-validation, receiver operating characteristics area under the curve for the composite score was 0.83 (95% confidence interval, 0.79-0.91) greater than for quantitative stenosis (0.66, 95% confidence interval, 0.57-0.76, P=0.005). Compared with stenosis, arterial NCP burden and a composite score combining quantitative stenosis and plaque burden from CT angiography significantly improves identification of downstream regional vascular dysfunction. © 2015 American Heart Association, Inc.

  7. Assessment of blood supply to intracranial pathologies in children using MR digital subtraction angiography

    International Nuclear Information System (INIS)

    Chooi, Weng Kong; Coley, Stuart C.; Connolly, Dan J.A.; Griffiths, Paul D.

    2006-01-01

    MR digital subtraction angiography (MR-DSA) is a contrast-enhanced MR angiographic sequence that enables time-resolved evaluation of the cerebral circulation. We describe the feasibility and technical success of our attempts at MR-DSA for the assessment of intracranial pathology in children. We performed MR-DSA in 15 children (age range 5 days to 16 years) referred for MR imaging because of known or suspected intracranial pathology that required a dynamic assessment of the cerebral vasculature. MR-DSA consisted of a thick (6-10 mm) slice-selective RF-spoiled fast gradient-echo sequence (RF-FAST) acquired before and during passage of an intravenously administered bolus of Gd-DTPA. The images were subtracted and viewed as a cine loop. MR-DSA was performed successfully in all patients. High-flow lesions were shown in four patients; these included vein of Galen aneurysmal malformation, dural fistula, and two partially treated arteriovenous malformations (AVMs). Low-flow lesions were seen in three patients, all of which were tumours. Normal flow was confirmed in eight patients including two with successfully treated AVMs, and in three patients with cavernomas. Our early experience suggests that MR-DSA is a realistic, non-invasive alternative to catheter angiography in certain clinical settings. (orig.)

  8. Quantitative Risk Assessment of Contact Sensitization

    DEFF Research Database (Denmark)

    Api, Anne Marie; Belsito, Donald; Bickers, David

    2010-01-01

    Background: Contact hypersensitivity quantitative risk assessment (QRA) for fragrance ingredients is being used to establish new international standards for all fragrance ingredients that are potential skin sensitizers. Objective: The objective was to evaluate the retrospective clinical data...

  9. Feasibility of 320-row area detector CT coronary angiography using 40 mL of contrast material: assessment of image quality and diagnostic accuracy

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Rihyeon; Park, Eun-Ah; Lee, Whal; Chung, Jin Wook [Seoul National University Hospital, Department of Radiology, Seoul (Korea, Republic of)

    2016-11-15

    To assess the image quality and diagnostic accuracy of 320-row area detector CT (320-ADCT) coronary angiography using 40 mL of contrast material in comparison with 60-mL protocol. This retrospective study included 183 patients who underwent 320-ADCT coronary angiography using 40 mL of contrast and additional 183 sex- and body mass index-matched patients using 60 mL of contrast constituting the control group. Both groups used the same 5-mL/sec injection rate. Quantitative image quality measurements and diagnostic accuracies were calculated and compared. Mean attenuation and contrast-to-noise ratio (CNR) at the aorta and all coronary arteries were lower in the 40-mL group than in the 60-mL group (all, p < 0.05), except for the CNR at proximal coronary arteries at 100 kVp (p = 0.073). However, the proportion of coronary segments with vessel attenuation >250 HU was not different between groups (all, p > 0.05), except for distal coronary arteries at 80 kVp (p = 0.001). Furthermore, there were no differences in per-patient and per-segment diagnostic accuracies between the groups (all, p > 0.05). 320-ADCT coronary angiography using 40 mL of contrast showed image quality and diagnostic accuracy comparable to the 60-mL protocol, demonstrating the clinical feasibility of lowering the risk of contrast-induced nephropathy through contrast volume reduction. (orig.)

  10. Diagnostic value of quantitative stenosis predictors with coronary CT angiography compared to invasive fractional flow reserve

    International Nuclear Information System (INIS)

    Wang, Rui; Renker, Matthias; Schoepf, U. Joseph; Wichmann, Julian L.; Fuller, Stephen R.; Rier, Jeremy D.; Bayer, Richard R.; Steinberg, Daniel H.; De Cecco, Carlo N.; Baumann, Stefan

    2015-01-01

    Highlights: • Evaluation of the diagnostic performance of CCTA predictors for coronary stenosis. • TAG was unable to detect hemodynamically significant coronary lesions. • CT-FFR, LL/MLD 4 and CCO provide enhanced diagnostic performance over CCTA. • CT-FFR was the best parameter. - Abstract: Objective: To evaluate the diagnostic performance of CCTA-derived stenosis predictors including CT-FFR for the detection of ischemia-inducing stenosis compared to invasive FFR. Materials and methods: Stenosis parameters were assessed using dual-source CT (DSCT). All patients underwent both CCTA and invasive FFR within 3 months and were retrospectively analyzed. Observers visually assessed all CCTA studies and performed multiple lesion measurements. Lesion length/minimal luminal diameter 4 (LL/MLD 4 ), transluminal attenuation gradient (TAG), corrected coronary attenuation (CCO) and CT-FFR were calculated. Results: The cohort included 32 patients (58 ± 12 years, 66%male). Among 32 coronary lesions, 8 (25%) were considered hemodynamically significant with an FFR <0.80. Compared to invasive FFR, the per-vessel sensitivity and specificity of CCTA, CT-FFR, LL/MLD 4 , CCO and TAG for detecting hemodynamically significant lesions were 100% and 54%, 100% and 91%, 85% and 92%, 66% and 88%, 37% and 58%, respectively. Receiver operating characteristics analysis resulted in an area under the curve of 0.91 for CT-FFR (p = 0.0005), 0.88 for LL/MLD 4 (p < 0.0001), 0.85 for CCO (p < 0.0001). TAG with an AUC of 0.67 (p = 0.152) was unable to discriminate between vessels with or without hemodynamically significant lesions. Conclusion: CT-FFR, LL/MLD 4 and CCO provide enhanced diagnostic performance over CCTA analysis alone for discrimination of hemodynamically significant coronary stenosis

  11. Diagnostic value of quantitative stenosis predictors with coronary CT angiography compared to invasive fractional flow reserve

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Rui [Heart & Vascular Center, Medical University of South Carolina, Ashley River Tower, 25 Courtenay Drive Charleston, SC 29425-2260 (United States); Department of Radiology, Beijing Anzhen Hospital, Capital Medical University, 100029 Beijing (China); Renker, Matthias [Heart & Vascular Center, Medical University of South Carolina, Ashley River Tower, 25 Courtenay Drive Charleston, SC 29425-2260 (United States); Kerckhoff Heart and Thorax Center, Benekestrasse 2-8, 61231 Bad Nauheim (Germany); Schoepf, U. Joseph, E-mail: schoepf@musc.edu [Heart & Vascular Center, Medical University of South Carolina, Ashley River Tower, 25 Courtenay Drive Charleston, SC 29425-2260 (United States); Wichmann, Julian L. [Heart & Vascular Center, Medical University of South Carolina, Ashley River Tower, 25 Courtenay Drive Charleston, SC 29425-2260 (United States); Department of Diagnostic and Interventional Radiology, University Hospital Frankfurt, Theodor-Stern-Kai 7, 60590 Frankfurt (Germany); Fuller, Stephen R.; Rier, Jeremy D.; Bayer, Richard R.; Steinberg, Daniel H. [Heart & Vascular Center, Medical University of South Carolina, Ashley River Tower, 25 Courtenay Drive Charleston, SC 29425-2260 (United States); De Cecco, Carlo N. [Heart & Vascular Center, Medical University of South Carolina, Ashley River Tower, 25 Courtenay Drive Charleston, SC 29425-2260 (United States); Departments of Radiological Sciences, Oncology, and Pathology, University of Rome “Sapienza”-Polo Pontino, Latina, Viale Regina Elena, 324-00161 Roma (Italy); Baumann, Stefan [Heart & Vascular Center, Medical University of South Carolina, Ashley River Tower, 25 Courtenay Drive Charleston, SC 29425-2260 (United States); First Department of Medicine, University Medical Centre Mannheim, University of Heidelberg, Theodor-Kutzer-Ufer 1-3, 68167 Mannheim (Germany)

    2015-08-15

    Highlights: • Evaluation of the diagnostic performance of CCTA predictors for coronary stenosis. • TAG was unable to detect hemodynamically significant coronary lesions. • CT-FFR, LL/MLD{sup 4} and CCO provide enhanced diagnostic performance over CCTA. • CT-FFR was the best parameter. - Abstract: Objective: To evaluate the diagnostic performance of CCTA-derived stenosis predictors including CT-FFR for the detection of ischemia-inducing stenosis compared to invasive FFR. Materials and methods: Stenosis parameters were assessed using dual-source CT (DSCT). All patients underwent both CCTA and invasive FFR within 3 months and were retrospectively analyzed. Observers visually assessed all CCTA studies and performed multiple lesion measurements. Lesion length/minimal luminal diameter{sup 4} (LL/MLD{sup 4}), transluminal attenuation gradient (TAG), corrected coronary attenuation (CCO) and CT-FFR were calculated. Results: The cohort included 32 patients (58 ± 12 years, 66%male). Among 32 coronary lesions, 8 (25%) were considered hemodynamically significant with an FFR <0.80. Compared to invasive FFR, the per-vessel sensitivity and specificity of CCTA, CT-FFR, LL/MLD{sup 4}, CCO and TAG for detecting hemodynamically significant lesions were 100% and 54%, 100% and 91%, 85% and 92%, 66% and 88%, 37% and 58%, respectively. Receiver operating characteristics analysis resulted in an area under the curve of 0.91 for CT-FFR (p = 0.0005), 0.88 for LL/MLD{sup 4} (p < 0.0001), 0.85 for CCO (p < 0.0001). TAG with an AUC of 0.67 (p = 0.152) was unable to discriminate between vessels with or without hemodynamically significant lesions. Conclusion: CT-FFR, LL/MLD{sup 4} and CCO provide enhanced diagnostic performance over CCTA analysis alone for discrimination of hemodynamically significant coronary stenosis.

  12. Renal artery and parenchymal changes after renal denervation: assessment by magnetic resonance angiography

    Energy Technology Data Exchange (ETDEWEB)

    Sanders, Margreet F.; Vink, Eva E.; Blankestijn, Peter J. [University Medical Center Utrecht, Department of Nephrology and Hypertension, PO Box 85500, Utrecht (Netherlands); Doormaal, Pieter Jan van; Habets, Jesse; Vonken, Evert-Jan; Leiner, Tim [University Medical Center Utrecht, Department of Radiology, Utrecht (Netherlands); Beeftink, Martine M.A.; Verloop, Willemien L.; Voskuil, Michiel [University Medical Center Utrecht, Department of Cardiology, Utrecht (Netherlands); Bots, Michiel L. [University Medical Center Utrecht, Julius Center for Health Sciences and Primary Care, Utrecht (Netherlands); Fadl Elmula, Fadl Elmula M. [Oslo University Hospital, Department of Internal Medicine and Department of Cardiology, Ullevaal, Oslo (Norway); Hammer, Frank [Cliniques Universitaires Saint-Luc, Universite Catholique de Louvain, Department of Radiology, Brussels (Belgium); Hoffmann, Pavel [Oslo University Hospital, Section for Interventional Cardiology, Department of Cardiology, Ullevaal, Oslo (Norway); Jacobs, Lotte; Staessen, Jan A. [University of Leuven, Studies Coordinating Centre, Research Unit Hypertension and Cardiovascular Epidemiology, KU Leuven Department of Cardiovascular Sciences, Leuven (Belgium); Mark, Patrick B.; Taylor, Alison H. [University of Glasgow, Institute of Cardiovascular and Medical Sciences, Glasgow, Scotland (United Kingdom); Persu, Alexandre; Renkin, Jean [Universite Catholique de Louvain, Pole of Cardiovascular Research, Institut de Recherche Experimentale et Clinique, Brussels (Belgium); Cliniques Universitaires Saint-Luc, Universite Catholique de Louvain, Cardiology Department, Brussels (Belgium); Roditi, Giles [Glasgow Royal Infirmary, Department of Radiology, Glasgow (United Kingdom); Spiering, Wilko [University Medical Centre Utrecht, Department of Vascular Medicine, Utrecht (Netherlands); Collaboration: on behalf of the European Network COordinating research on Renal Denervation (ENCOReD) Consortium

    2017-09-15

    Relatively little is known about the incidence of long-term renal damage after renal denervation (RDN), a potential new treatment for hypertension. In this study the incidence of renal artery and parenchymal changes, assessed with contrast-enhanced magnetic resonance angiography (MRA) after RDN, is investigated. This study is an initiative of ENCOReD, a collaboration of hypertension expert centres. Patients in whom an MRA was performed before and after RDN were included. Scans were evaluated by two independent, blinded radiologists. Primary outcome was the change in renal artery morphology and parenchyma. MRAs from 96 patients were analysed. Before RDN, 41 renal anomalies were observed, of which 29 mostly mild renal artery stenoses. After a median time of 366 days post RDN, MRA showed a new stenosis (25-49% lumen reduction) in two patients and progression of pre-existing lumen reduction in a single patient. No other renal changes were observed and renal function remained stable. We observed new or progressed renal artery stenosis in three out of 96 patients, after a median time of 12 months post RDN (3.1%). Procedural angiographies showed that ablations were applied near the observed stenosis in only one of the three patients. (orig.)

  13. Diagnostic value of multislice computed tomography angiography in coronary artery disease: A meta-analysis

    International Nuclear Information System (INIS)

    Sun Zhonghua; Jiang Wen

    2006-01-01

    Purpose: To perform a meta-analysis of the diagnostic value of multislice CT (MSCT) angiography in the detection of coronary artery disease (CAD) when compared to conventional coronary angiography. Materials and methods: A search of PubMed and MEDLINE databases for English literature was performed. Only studies with at least 10 patients comparing MSCT angiography with conventional coronary angiography in the detection of CAD were included. Diagnostic value of MSCT angiography compared to coronary angiography was compared and analyzed at segment-, vessel- and patient-based assessment. Results: 47 studies (67 comparisons) met the criteria and were included in our study. Pooled overall sensitivity, specificity and 95% confidence interval for MSCT angiography in the detection of CAD were 83% (79%, 89%), 93% (91%, 96%) at segment-based analysis; 90% (87%, 94%), 87% (80%, 93%) at vessel-based analysis; and 91% (88%, 95%), 86% (81%, 92%) at patient-based analysis, respectively. Diagnostic accuracy of MSCT angiography in evaluating assessable segments was significantly improved with 64-slice scanners when compared to that with 4- and 16-slice scanners (p < 0.05). Conclusion: Our meta-analysis showed that MSCT angiography has potential diagnostic accuracy in the detection of CAD. Diagnostic performance of MSCT angiography has been significantly improved with the latest 64-slice CT, with resultant high qualitative and quantitative diagnostic accuracy. 16-slice CT was limited in spatial resolution which makes it difficult to perform quantitative assessment of coronary artery stenoses

  14. Challenges in Risk Assessment: Quantitative Risk Assessment

    OpenAIRE

    Jacxsens, Liesbeth; Uyttendaele, Mieke; De Meulenaer, Bruno

    2016-01-01

    The process of risk analysis consists out of three components, risk assessment, risk management and risk communication. These components are internationally well spread by Codex Alimentarius Commission as being the basis for setting science based standards, criteria on food safety hazards, e.g. setting maximum limits of mycotoxins in foodstuffs. However, the technical component risk assessment is hard to elaborate and to understand. Key in a risk assessment is the translation of biological or...

  15. Teaching quantitative biology: goals, assessments, and resources.

    Science.gov (United States)

    Aikens, Melissa L; Dolan, Erin L

    2014-11-05

    More than a decade has passed since the publication of BIO2010, calling for an increased emphasis on quantitative skills in the undergraduate biology curriculum. In that time, relatively few papers have been published that describe educational innovations in quantitative biology or provide evidence of their effects on students. Using a "backward design" framework, we lay out quantitative skill and attitude goals, assessment strategies, and teaching resources to help biologists teach more quantitatively. Collaborations between quantitative biologists and education researchers are necessary to develop a broader and more appropriate suite of assessment tools, and to provide much-needed evidence on how particular teaching strategies affect biology students' quantitative skill development and attitudes toward quantitative work. © 2014 Aikens and Dolan. This article is distributed by The American Society for Cell Biology under license from the author(s). Two months after publication it is available to the public under an Attribution–Noncommercial–Share Alike 3.0 Unported Creative Commons License (http://creativecommons.org/licenses/by-nc-sa/3.0).

  16. Fallopian tube recanalisation using dedicated radiographic tubal assessment set in angiography suite

    International Nuclear Information System (INIS)

    Al-Omari, M.H; Rousan, L.; Al-balas, H.; Alawneh, K.; El-heis, M.; Al-mnayyis, A.; Obeidat, N.; Amarin, Z.; Zayed, F.; Omari, Z.; Hanania, R.

    2014-01-01

    Fallopian tube recanalisation (FTR) for proximal fallopian tube obstruction (PFTO) is considered a good treatment option for tubal infertility. The aim of this study was to assess the safety and the technical and clinical success rates of FTR using a dedicated radiographic tubal assessment set (FluoroSet®) in the angiography suite. This study is a retrospective analysis of data prospectively collected between February 2007 and June 2011 at King Abdullah University Hospital, Irbid, Jordan. During this period, 61 patients affected by PFTO underwent FTR using FluoroSet® at our institution. The mean age of patients was 34 years (range 20-45 years), and the mean duration of infertility was 4 years (range 2-14 years). The procedure was performed with conscious sedation under fluoroscopic guidance in the angiography suite. The obstructed tube was accessed with a 5-Fr multipurpose catheter, and the obstruction was crossed with a 0.35-Fr hydrophilic guide wire until the wire coiled freely into the peritoneal cavity. Patency of the tube was then confirmed by selective salpingiogram. Technical success rate was recorded, and patients were followed up for evidence of pregnancy over 12 months. The procedure was technically successful in all patients. Minor bleeding and postprocedural pain occurred in most patients; however, there were no major complications encountered. Twenty-five patients (41%) became pregnant. Successful deliveries of full-term infants were reported in 21 patients (84%). Miscarriage was reported in four patients (16%). No ectopic pregnancies were detected, and all deliveries were full-term. The technical success rate was 100% and the clinical success rate was 41%. Selective salpingography and FTR using FluoroSet® is a safe and effective method. FTR is recommended as the first intervention in patients with PFTO. In experienced hands with dedicated equipment and in an appropriate setting, the success rate is high, and this treatment should be offered to

  17. The Quantitative Measurements of Vascular Density and Flow Areas of Macula Using Optical Coherence Tomography Angiography in Normal Volunteers.

    Science.gov (United States)

    Ghassemi, Fariba; Fadakar, Kaveh; Bazvand, Fatemeh; Mirshahi, Reza; Mohebbi, Masoumeh; Sabour, Siamak

    2017-06-01

    The quantification of the density of macular vascular networks and blood flow areas in the foveal and parafoveal area in healthy subjects using optical coherence tomography angiography (OCTA). Cross-sectional, prospective study in an institutional setting at the Retina Services of Farabi Eye Hospital. One hundred twelve normal volunteers with no known ocular or systemic disease were included, including patient numbers (one or both eyes), selection procedures, inclusion/exclusion criteria, randomization procedure, and masking. En face angiogram OCTA was performed on a 3 mm × 3 mm region centered on the macula. Automated thresholding and measuring algorithm method for foveal and parafoveal blood flow and vascular density (VD) were used. The density of macular vascular networks and blood flow area in the foveal and parafoveal area were measured. A total of 224 healthy eyes from 112 subjects with a mean age of 36.4 years ± 11.3 years were included. In the foveal region, the VD of the superficial capillary network (sCN) was significantly higher than that of the deep capillary network (dCN) (31.1% ± 5.5% vs. 28.3% ± 7.2%; P < .001), whereas in the parafoveal area, VD was higher in the dCN (62.24% ± 2.8% vs. 56.5% ± 2.5%; P < .001). Flow area in the 1-mm radius circle in the sCN was less than in the dCN. Superficial foveal avascular zone (sFAZ) size was negatively correlated with the VD of the foveal sCN, but in the deep FAZ (dFAZ) was not correlated with VD or blood flow area of the fovea. There was no difference between measured VD and blood flow surface area in both eyes of the subjects. OCTA could be used as a noninvasive, repeatable, layer-free method in quantitative evaluation of VD and blood flow of macular area. The normal quantities of the vascular plexus density and flow will help in better understanding the pathophysiological basis of the vascular disease of retina. [Ophthalmic Surg Lasers Imaging Retina. 2017;48:478-486.]. Copyright 2017, SLACK

  18. Groundwater quantitative status assessment in Slovenia

    Directory of Open Access Journals (Sweden)

    Mišo Andjelov

    2006-12-01

    Full Text Available The framework for the integrated water management of the entire EU area has been set, when the European Parliament and Council passed the Directive 2000/60/EC in 2000. According to the directive, the evaluation of meeting the environmental objectives is based also upon the assessment of quantitative and chemical status of individual groundwater body.The assessment of quantitative status of groundwater bodies under the Groundwater Directive of EU is based on the definition of the available groundwater quantity.Thisisalong period mean annual renewable quantity of water in the groundwater body, reduced by the quantity of the long period annual groundwater discharge, which is required for sustaining ecological objectives concerning surface water bodies and preservation of the ecosistems, connected with the groundwater bodies.Methodological approach and the results of the first groundwater quantitive status assessment for 21 groundwater bodies in Slovenia are given in this paper. The assessment of the available groundwater quantity in Slovenian groundwater bodies in the period from 1990 to 2001 are 1,43 ⋅ 109 m3 per year, and 727,4 m3 per capita per year respectively. In the year 2002 abstracted groundwater (0,23 ⋅ 109 m3 per year represents 15 percent of the available groundwater reserves in Slovenia. For all Slovenian groundwater bodies quantitative status was assessed as good.

  19. Accuracy of unenhanced magnetic resonance angiography for the assessment of renal artery stenosis

    Directory of Open Access Journals (Sweden)

    Carmen Sebastià

    2016-01-01

    Conclusion: U-MRA is a reliable diagnostic method to depict normal and stenotic main renal arteries. U-MRA can be used as an alternative to contrast-enhanced magnetic resonance angiography or computer tomography angiography in patients with renal insufficiency unless FMD is suspected.

  20. Indocyanine green fluorescence angiography for quantitative evaluation of in situ parathyroid gland perfusion and function after total thyroidectomy.

    Science.gov (United States)

    Lang, Brian Hung-Hin; Wong, Carlos K H; Hung, Hing Tsun; Wong, Kai Pun; Mak, Ka Lun; Au, Kin Bun

    2017-01-01

    Because the fluorescent light intensity on an indocyanine green fluorescence angiography reflects the blood perfusion within a focused area, the fluorescent light intensity in the remaining in situ parathyroid glands may predict postoperative hypocalcemia risk after total thyroidectomy. Seventy patients underwent intraoperative indocyanine green fluorescence angiography after total thyroidectomy. Any parathyroid glands with a vascular pedicle was left in situ while any parathyroid glands without pedicle or inadvertently removed was autotransplanted. After total thyroidectomy, an intravenous 2.5 mg indocyanine green fluorescence angiography was given and real-time fluorescent images of the thyroid bed were recorded using the SPY imaging system (Novadaq, Ontario, Canada). The fluorescent light intensity of each indocyanine green fluorescence angiography as well as the average and greatest fluorescent light intensity in each patient were calculated. Postoperative hypocalcemia was defined as adjusted calcium 150% developed postoperative hypocalcemia while 9 (81.8%) patients with a greatest fluorescent light intensity ≤150% did. Similarly, no patients with an average fluorescent light intensity >109% developed PH while 9 (30%) with an average fluorescent light intensity ≤109% did. The greatest fluorescent light intensity was more predictive than day-0 postoperative hypocalcemia (P = .027) and % PTH drop day-0 to 1 (P parathyroid glands function and predicting postoperative hypocalcemia risk after total thyroidectomy. Copyright © 2016 Elsevier Inc. All rights reserved.

  1. Catheter Angiography

    Medline Plus

    Full Text Available ... Videos About Us News Physician Resources Professions Site Index A-Z Catheter Angiography Catheter angiography uses a ... few millimeters) in the skin where the catheter can be inserted into an artery. The catheter is ...

  2. Catheter Angiography

    Medline Plus

    Full Text Available ... story about radiology? Share your patient story here Images × Image Gallery Interventional radiologist performing an angiography exam View ... ray, Interventional Radiology and Nuclear Medicine Radiation Safety Images related to Catheter Angiography Sponsored by Please note ...

  3. Catheter Angiography

    Medline Plus

    Full Text Available ... you are pregnant and discuss any recent illnesses, medical conditions, medications you're taking and allergies, especially ... is Catheter Angiography? Angiography is a minimally invasive medical test that helps physicians diagnose and treat medical ...

  4. Catheter Angiography

    Medline Plus

    Full Text Available ... angiography exam View full size with caption Related Articles and Media Angioplasty and Vascular Stenting MR Angiography ( ... facilities database . This website does not provide cost information. The costs for specific medical imaging tests, treatments ...

  5. Catheter Angiography

    Medline Plus

    Full Text Available ... resonance imaging (MRI) In catheter angiography, a thin plastic tube, called a catheter , is inserted into an ... The catheter used in angiography is a long plastic tube about as thick as a strand of ...

  6. Assessment of 64-row computed tomographic angiography for diagnosis and pretreatment planning in pulmonary sequestration.

    Science.gov (United States)

    Ren, Jian-Zhuang; Zhang, Kai; Huang, Guo-Hao; Zhang, Meng-Fan; Zhou, Peng-Li; Han, Xin-Wei; Duan, Xu-Hua; Li, Zhen

    2014-01-01

    This study was done to evaluate the clinical implications and results of a prospective protocol using 64-row computed tomographic angiography (CTA) for diagnosis and pre-treatment planning in pulmonary sequestration (PS). Forty-five patients with suspected PS were referred for CTA examination. The accuracy, sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of measures used to detect PS were determined by patient-based and aberrant systemic artery-based evaluations. The location, the size and the number of aberrant systemic arteries, and the feasibility of endovascular treatment were analysed. The capability of CTA to provide a working view and the accuracy of measurements in choosing a coil were also assessed. Digital subtraction angiography and/or surgery revealed PS in 38 patients, and 7 patients had no PS. The patient-based evaluation yielded an accuracy of 97.8 %, sensitivity of 97.4 %, specificity of 100 %, PPV of 100 % and NPV of 87.5 %, in the detection of PS. CTA clearly depicted the PS in all 38 patients, and the aberrant systemic artery was accurately demonstrated in 37 out of 38 patients where endovascular treatment was possible. Working views for endovascular treatment were found in all patients with PS, and the choice of coil was correct in 37 out of 38 patients using CTA. 64-row CTA appears to be effective in terms of supporting accurate diagnosis and pre-treatment planning in PS. CTA is not only able to provide clear visualisation of aberrant systemic arteries but also provides detailed images of abnormal lung parenchyma and the airways.

  7. Deforestation since independence: A quantitative assessment of ...

    African Journals Online (AJOL)

    Deforestation since independence: A quantitative assessment of four decades of land-cover change in Malawi. ... pressure and demographic factors are important predictors of deforestation rate within our study area. Keywords: afforestation, Africa, deforestation, drivers, land-use change, reforestation, rural, urban ...

  8. Quantitative Assessment of Banned Corticosteroids in Cosmetic ...

    African Journals Online (AJOL)

    Quantitative Assessment of Banned Corticosteroids in Cosmetic Creams in Lagos Metropolis. B O Silva. Abstract. Background: Cosmetic creams are widely used for good causes. They however pose dangers when they contain banned corticosteroids. As part of its control measures and its effort on public safety, NAFDAC ...

  9. Catheter Angiography

    Medline Plus

    Full Text Available ... Z Catheter Angiography Catheter angiography uses a catheter, x-ray imaging guidance and an injection of contrast material ... vessels in the body. Angiography is performed using: x-rays with catheters computed tomography (CT) magnetic resonance imaging ( ...

  10. Quantitative Real-Time Fluoroscopy Analysis on Measurement of the Hepatic Arterial Flow During Transcatheter Arterial Chemoembolization of Hepatocellular Carcinoma: Comparison with Quantitative Digital Subtraction Angiography Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Yi-Yang; Lee, Rheun-Chuan, E-mail: rclee@vghtpe.gov.tw; Guo, Wan-Yuo, E-mail: wyguo@vghtpe.gov.tw; Chu, Wei-Fa [Taipei Veterans General Hospital, Department of Radiology (China); Wu, Frank Chun-Hsien [Siemens Healthcare Ltd. (China); Gehrisch, Sonja [Siemens Healthcare GmbH (Germany)

    2016-11-15

    PurposeTo quantify the arterial flow change during transcatheter arterial chemoembolization (TACE) for hepatocellular carcinoma (HCC) using digital subtraction angiography, quantitative color-coding analysis (d-QCA), and real-time subtraction fluoroscopy QCA (f-QCA).Materials and MethodsThis prospective study enrolled 20 consecutive patients with HCC who had undergone TACE via a subsegmental approach between February 2014 and April 2015. The TACE endpoint was a sluggish antegrade tumor-feeding arterial flow. d-QCA and f-QCA were used for determining the relative maximal density time (rT{sub max}) of the selected arteries. The rT{sub max} of the selected arteries was analyzed in d-QCA and f-QCA before and after TACE, and its correlation in both analyses was evaluated.ResultsThe pre- and post-TACE rT{sub max} of the embolized segmental artery in d-QCA and f-QCA were 1.59 ± 0.81 and 2.97 ± 1.80 s (P < 0.001) and 1.44 ± 0.52 and 2.28 ± 1.02 s (P < 0.01), respectively. The rT{sub max} of the proximal hepatic artery did not significantly change during TACE in d-QCA and f-QCA. The Spearman correlation coefficients of the pre- and post-TACE rT{sub max} of the embolized segmental artery between d-QCA and f-QCA were 0.46 (P < 0.05) and 0.80 (P < 0.001). Radiation doses in one series of d-QCA and f-QCA were 140.7 ± 51.5 milligray (mGy) and 2.5 ± 0.7 mGy, respectively.Conclusionsf-QCA can quantify arterial flow changes with a higher temporal resolution and lower radiation dose. Flow quantification of the embolized segmental artery using f-QCA and d-QCA is highly correlated.

  11. Radiological interpretation 2020: Toward quantitative image assessment

    International Nuclear Information System (INIS)

    Boone, John M.

    2007-01-01

    The interpretation of medical images by radiologists is primarily and fundamentally a subjective activity, but there are a number of clinical applications such as tumor imaging where quantitative imaging (QI) metrics (such as tumor growth rate) would be valuable to the patient’s care. It is predicted that the subjective interpretive environment of the past will, over the next decade, evolve toward the increased use of quantitative metrics for evaluating patient health from images. The increasing sophistication and resolution of modern tomographic scanners promote the development of meaningful quantitative end points, determined from images which are in turn produced using well-controlled imaging protocols. For the QI environment to expand, medical physicists, physicians, other researchers and equipment vendors need to work collaboratively to develop the quantitative protocols for imaging, scanner calibrations, and robust analytical software that will lead to the routine inclusion of quantitative parameters in the diagnosis and therapeutic assessment of human health. Most importantly, quantitative metrics need to be developed which have genuine impact on patient diagnosis and welfare, and only then will QI techniques become integrated into the clinical environment.

  12. Coronary stent on coronary CT angiography: Assessment with model-based iterative reconstruction technique

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Eun Chae; Kim, Yeo Koon; Chun, Eun Ju; Choi, Sang IL [Dept. of of Radiology, Seoul National University Bundang Hospital, Seongnam (Korea, Republic of)

    2016-05-15

    To assess the performance of model-based iterative reconstruction (MBIR) technique for evaluation of coronary artery stents on coronary CT angiography (CCTA). Twenty-two patients with coronary stent implantation who underwent CCTA were retrospectively enrolled for comparison of image quality between filtered back projection (FBP), adaptive statistical iterative reconstruction (ASIR) and MBIR. In each data set, image noise was measured as the standard deviation of the measured attenuation units within circular regions of interest in the ascending aorta (AA) and left main coronary artery (LM). To objectively assess the noise and blooming artifacts in coronary stent, we additionally measured the standard deviation of the measured attenuation and intra-luminal stent diameters of total 35 stents with dedicated software. All image noise measured in the AA (all p < 0.001), LM (p < 0.001, p = 0.001) and coronary stent (all p < 0.001) were significantly lower with MBIR in comparison to those with FBP or ASIR. Intraluminal stent diameter was significantly higher with MBIR, as compared with ASIR or FBP (p < 0.001, p = 0.001). MBIR can reduce image noise and blooming artifact from the stent, leading to better in-stent assessment in patients with coronary artery stent.

  13. Ferumoxytol-enhanced magnetic resonance angiography for the assessment of potential kidney transplant recipients

    Energy Technology Data Exchange (ETDEWEB)

    Stoumpos, Sokratis; Mark, Patrick B. [Queen Elizabeth University Hospital, Renal and Transplant Unit, Glasgow (United Kingdom); University of Glasgow, Institute of Cardiovascular and Medical Sciences, BHF Glasgow Cardiovascular Research Centre, Glasgow (United Kingdom); Hennessy, Martin; Kasthuri, Ram; Roditi, Giles [Queen Elizabeth University Hospital, Department of Radiology, Glasgow (United Kingdom); Vesey, Alex T.; Kingsmore, David B. [Queen Elizabeth University Hospital, Renal and Transplant Unit, Glasgow (United Kingdom); Radjenovic, Aleksandra [University of Glasgow, Institute of Cardiovascular and Medical Sciences, BHF Glasgow Cardiovascular Research Centre, Glasgow (United Kingdom)

    2018-01-15

    Traditional contrast-enhanced methods for scanning blood vessels using magnetic resonance imaging (MRI) or CT carry potential risks for patients with advanced kidney disease. Ferumoxytol is a superparamagnetic iron oxide nanoparticle preparation that has potential as an MRI contrast agent in assessing the vasculature. Twenty patients with advanced kidney disease requiring aorto-iliac vascular imaging as part of pre-operative kidney transplant candidacy assessment underwent ferumoxytol-enhanced magnetic resonance angiography (FeMRA) between December 2015 and August 2016. All scans were performed for clinical indications where standard imaging techniques were deemed potentially harmful or inconclusive. Image quality was evaluated for both arterial and venous compartments. First-pass and steady-state FeMRA using incremental doses of up to 4 mg/kg body weight of ferumoxytol as intravenous contrast agent for vascular enhancement was performed. Good arterial and venous enhancements were achieved, and FeMRA was not limited by calcification in assessing the arterial lumen. The scans were diagnostic and all patients completed their studies without adverse events. Our preliminary experience supports the feasibility and utility of FeMRA for vascular imaging in patients with advanced kidney disease due for transplant listing, which has the advantages of obtaining both arteriography and venography using a single test without nephrotoxicity. (orig.)

  14. Contrast-enhanced MR 3D angiography in the assessment of brain AVMs

    International Nuclear Information System (INIS)

    Unlu, Ercument; Temizoz, Osman; Albayram, Sait; Genchellac, Hakan; Hamamcioglu, M. Kemal; Kurt, Imran; Demir, M. Kemal

    2006-01-01

    Background and purpose: Digital subtraction angiography (DSA) is the current reference standard for the diagnosis, assessment, and management of brain arteriovenous malformations (AVMs). The purpose of this study was to compare the diagnostic utility of three-dimensional (3D) time-of-flight (TOF) magnetic resonance angiography (MRA) and contrast-enhanced 3D MRA in patients with intracranial arteriovenous malformations (AVMs) in different sizes and locations. The AVM diagnosis was proved via DSA and almost half of the patients had also hematoma. Materials and methods: Two radiologists, experienced on neurovascular imaging and independent from each other, retrospectively reviewed two MRA techniques and DSA with regard to the assessment of feeding arteries, AVM nidus, and venous drainage patterns on 20 patients with 23 examinations by scoring system. Disagreements were resolved by consensus. Results: An excellent agreement between contrast-enhanced MRA and DSA was found in order to assess the numbers of arterial feeders and draining veins (Spearman r = 0.913, P < 0.001). The average scores in contrast-enhanced MRA for feeders, nidi, and drainers were respectively 2.26, 2.69, and 2.48, while in TOF-MRA they are 1.96, 1.35, and 0.89, respectively. Conclusion: Compared to TOF-MRA, 3D contrast-enhanced MRA is useful for visualization by subtraction technique of malformation components presented by hematoma or by haem product. On the other hand, for the cases presented by slow or complex flow that is especially in around or nidi or around the venous portion is also advantageous because of the independence from flow-related enhancement. Therapeutic effects were clearly demonstrated in three follow-up patients. A major limitation of this technique is the low spatial resolution. Since there is such a limitation, arterial feeder of a case with micro-AVM is not detected by contrast-enhanced MRA and nidus for the same case was observed retrospectively. In this respect, we

  15. Contrast-enhanced MR 3D angiography in the assessment of brain AVMs

    Energy Technology Data Exchange (ETDEWEB)

    Unlu, Ercument [Department of Radiology, Trakya University Medicine School, Edirne (Turkey)]. E-mail: drercument@yahoo.com; Temizoz, Osman [Department of Radiology, Trakya University Medicine School, Edirne (Turkey); Albayram, Sait [Department of Radiology, Istanbul University, Cerrahpasa Medicine School, Istanbul (Turkey); Genchellac, Hakan [Department of Radiology, Trakya University Medicine School, Edirne (Turkey); Hamamcioglu, M. Kemal [Department of Neurosurgery, Trakya University Medicine School, Edirne (Turkey); Kurt, Imran [Department of Biostatistics, Trakya University Medicine School, Edirne (Turkey); Demir, M. Kemal [Department of Radiology, Trakya University Medicine School, Edirne (Turkey)

    2006-12-15

    Background and purpose: Digital subtraction angiography (DSA) is the current reference standard for the diagnosis, assessment, and management of brain arteriovenous malformations (AVMs). The purpose of this study was to compare the diagnostic utility of three-dimensional (3D) time-of-flight (TOF) magnetic resonance angiography (MRA) and contrast-enhanced 3D MRA in patients with intracranial arteriovenous malformations (AVMs) in different sizes and locations. The AVM diagnosis was proved via DSA and almost half of the patients had also hematoma. Materials and methods: Two radiologists, experienced on neurovascular imaging and independent from each other, retrospectively reviewed two MRA techniques and DSA with regard to the assessment of feeding arteries, AVM nidus, and venous drainage patterns on 20 patients with 23 examinations by scoring system. Disagreements were resolved by consensus. Results: An excellent agreement between contrast-enhanced MRA and DSA was found in order to assess the numbers of arterial feeders and draining veins (Spearman r = 0.913, P < 0.001). The average scores in contrast-enhanced MRA for feeders, nidi, and drainers were respectively 2.26, 2.69, and 2.48, while in TOF-MRA they are 1.96, 1.35, and 0.89, respectively. Conclusion: Compared to TOF-MRA, 3D contrast-enhanced MRA is useful for visualization by subtraction technique of malformation components presented by hematoma or by haem product. On the other hand, for the cases presented by slow or complex flow that is especially in around or nidi or around the venous portion is also advantageous because of the independence from flow-related enhancement. Therapeutic effects were clearly demonstrated in three follow-up patients. A major limitation of this technique is the low spatial resolution. Since there is such a limitation, arterial feeder of a case with micro-AVM is not detected by contrast-enhanced MRA and nidus for the same case was observed retrospectively. In this respect, we

  16. American College of Cardiology/European Society of Cardiolgoy International Study of Angiographic Data Compression Phase II: the effects of varying JPEG data compression levels on the quantitative assessment of the degree of stenosis in digital coronary angiography. Joint Photographic Experts Group.

    Science.gov (United States)

    Tuinenburg, J C; Koning, G; Hekking, E; Zwinderman, A H; Becker, T; Simon, R; Reiber, J H

    2000-04-01

    This report describes whether lossy Joint Photographic Experts Group (UPEG) image compression/decompression has an effect on the quantitative assessment of vessel sizes by state-of-the-art quantitative coronary arteriography (QCA). The Digital Imaging and Communications in Medicine (DICOM) digital exchange standard for angiocardiography prescribes that images must be stored loss free, thereby limiting JPEG compression to a maximum ratio of 2:1. For practical purposes it would be desirable to increase the compression ratio (CR), which would lead to lossy image compression. A series of 48 obstructed coronary segments were compressed/decompressed at CR 1:1 (uncompressed), 6:1, 10:1 and 16:1 and analyzed blindly and in random order using the QCA-CMS analytical software. Similar catheter and vessel start- and end-points were used within each image quartet, respectively. All measurements were repeated after several weeks using newly selected start- and end-points. Three different sub-analyses were carried out: the intra-observer, fixed inter-compression and variable inter-compression analyses, with increasing potential error sources, respectively. The intra-observer analysis showed significant systematic and random errors in the calibration factor at JPEG CR 10:1. The fixed inter-compression analysis demonstrated systematic errors in the calibration factor and recalculated vessel parameter results at CR 16:1 and for the random errors at CR 10:1 and 16:1. The variable inter-compression analysis presented systematic and random errors in the calibration factor and recalculated parameter results at CR 10:1 and 16:1. Any negative effect at CR 6:1 was found only for the calibration factor of the variable inter-compression analysis, which did not show up in the final vessel measurements. Compression ratios of 10:1 and 16:1 affected the QCA results negatively and therefore should not be used in clinical research studies.

  17. Quantitative myocardial perfusion by O-15-water PET

    DEFF Research Database (Denmark)

    Thomassen, Anders; Petersen, Henrik; Johansen, Allan

    2015-01-01

    disease (CAD). METHODS AND RESULTS: Forty-four patients with suspected CAD were included prospectively and underwent coronary CT-angiography and quantitative MBF assessment with O-15-water PET followed by invasive, quantitative coronary angiography, which served as reference. MBF was calculated...

  18. [Novel Examination Procedures for the Assessment of Retinal Artery Occlusion by OCT Angiography].

    Science.gov (United States)

    Loidl, Max; Enders, Christian; Werner, Jens Ulrich; Lang, Gerhard K; Lang, Gabriele E

    2017-09-01

    Background Retinal artery occlusion (RAO) is the most common primary angiopathy of the retina. With an incidence of 0.01 - 0.15%, this it is a rather rare disease, but is associated with irreversible damage to the retina and a poor prognosis for visual acuity. Since the 1960s - when fluorescence angiography (FA) was developed -, there has been little change in diagnostic investigations. FA is still the standard procedure for the assessment of retinal artery occlusions. With the development of OCT angiography (OCT-A), new multimodal imaging procedures have become possible. Patients/Methods We used Zeiss AngioPlex ® -OCT-A technology in combination with the CIRRUS ™ HD-OCT 5000 (Carl Zeiss Meditec, Inc., Dublin, USA) to create 6 × 6 mm and 3 × 3 mm volume scans of the area of non-perfusion in patients with RAO. Qualitative OCT-A analysis was performed on retinal images segmented into the superficial and deep retinal capillary plexus. In addition to this, volumetric scans can be segmented to any specific depth of the retina. On the basis of 4 cases, we demonstrate that OCT-A can be used to evaluate RAO. We present typical OCT-A findings. Results OCT-A images allow the detection of non-perfused areas in patients with acute and chronic RAO. The zones of reduced vascular perfusion are differently distributed in the superficial and deep retinal capillary plexus. In both acute and chronic cases of RAO, OCT-A offers important information on retinal vascular perfusion. Conclusion OCT-A can be used in the diagnosis and monitoring of acute and chronic cases of RAO. The advantages of OCT-A are that this technique is non-invasive and allows three dimensional microvascular visualisation within seconds. Although artefacts and the currently limited field of view can make it difficult to interpret OCT-A images reliably, these findings suggest that OCT-A may in future replace FA in the assessment of RAO in most patients. Georg Thieme Verlag KG Stuttgart · New

  19. Coronary Computed Tomography Angiography in the Assessment of Acute Chest Pain in the Emergency Room

    International Nuclear Information System (INIS)

    Prazeres, Carlos Eduardo Elias dos; Cury, Roberto Caldeira; Carneiro, Adriano Camargo de Castro; Rochitte, Carlos Eduardo

    2013-01-01

    The coronary computed tomography angiography has recently emerged as an accurate diagnostic tool in the evaluation of coronary artery disease, providing diagnostic and prognostic data that correlate directly with the data provided by invasive coronary angiography. The association of recent technological developments has allowed improved temporal resolution and better spatial coverage of the cardiac volume with significant reduction in radiation dose, and with the crucial need for more effective protocols of risk stratification of patients with chest pain in the emergency room, recent evaluation of the computed tomography coronary angiography has been performed in the setting of acute chest pain, as about two thirds of invasive coronary angiographies show no significantly obstructive coronary artery disease. In daily practice, without the use of more efficient technologies, such as coronary angiography by computed tomography, safe and efficient stratification of patients with acute chest pain remains a challenge to the medical team in the emergency room. Recently, several studies, including three randomized trials, showed favorable results with the use of this technology in the emergency department for patients with low to intermediate likelihood of coronary artery disease. In this review, we show data resulting from coronary angiography by computed tomography in risk stratification of patients with chest pain in the emergency room, its diagnostic value, prognosis and cost-effectiveness and a critical analysis of recently published multicenter studies

  20. Assessment of Effective Dose Associated with Coronary Computed Tomography Angiography in Isfahan Province, Iran.

    Science.gov (United States)

    Tavakoli, Mohammadbagher; Faraji, Reihane; Alirezaei, Zahra; Nateghian, Zohre

    2018-01-01

    Computed tomography coronary angiography (CTCA) has generated a great interest over the past two decades, due to its high diagnostic accuracy and efficacy in the assessment of patients having coronary artery disease. This method is associated with high radiation dose and this has raised serious concerns in the literature. Effective dose (E) is a single parameter meant to reflect the relative risk from exposure to ionizing radiation. Therefore, it is necessary to calculate this parameter to indicate ionizing radiation relative risk. The aim of this study was to calculate the effective dose from 64-slice CTCA in Isfahan. To calculate the effective dose, an ionization chamber and a body phantom with diameter of 32 cm and length of 15 cm were used. CTCA radiation conditions commonly used in two centers were applied for this work. For all scans, computed tomography volume dose index (CTDI v ), dose-length product (DLP), and effective dose were obtained using dose-length-product method. The obtained CTDI v , DLP, and effective dose were compared in two centers, and mean, maximum, and minimum values of effective dose for heart coronary CT angiography (CCTA) examinations and calcium score were compared with other studies. The amount of average, maximum, and minimum effective doses for heart CCTA examinations in two centers are 4.65 ± 0.06, 6.0489, and 3.492 mSv, respectively, and for calcium score test are, 1.04 ± 0.04, 2.155, and 0.98 mSv, respectively. CTDI v , DLP, and effective dose values did not show any significant difference in two centers. Although the effective dose of CTCA and calcium score was lower than that of other studies, it is reasonable to reduce the effective dose to the minimum possible value to reduce the risk of cancer associated with ionizing radiation. The results of this study can be used to introduce the effective dose as a local diagnostic reference dose (DRL) for CTCA examinations in Isfahan Province.

  1. Coronary Artery Disease: Analysis of Diagnostic Performance of CT Perfusion and MR Perfusion Imaging in Comparison with Quantitative Coronary Angiography and SPECT-Multicenter Prospective Trial.

    Science.gov (United States)

    Rief, Matthias; Chen, Marcus Y; Vavere, Andrea L; Kendziora, Benjamin; Miller, Julie M; Bandettini, W Patricia; Cox, Christopher; George, Richard T; Lima, João; Di Carli, Marcelo; Plotkin, Michail; Zimmermann, Elke; Laule, Michael; Schlattmann, Peter; Arai, Andrew E; Dewey, Marc

    2018-02-01

    Purpose To compare the diagnostic performance of stress myocardial computed tomography (CT) perfusion with that of stress myocardial magnetic resonance (MR) perfusion imaging in the detection of coronary artery disease (CAD). Materials and Methods All patients gave written informed consent prior to inclusion in this institutional review board-approved study. This two-center substudy of the prospective Combined Noninvasive Coronary Angiography and Myocardial Perfusion Imaging Using 320-Detector Row Computed Tomography (CORE320) multicenter trial included 92 patients (mean age, 63.1 years ± 8.1 [standard deviation]; 73% male). All patients underwent perfusion CT and perfusion MR imaging with either adenosine or regadenoson stress. The predefined reference standards were combined quantitative coronary angiography (QCA) and single-photon emission CT (SPECT) or QCA alone. Results from coronary CT angiography were not included, and diagnostic performance was evaluated with the Mantel-Haenszel test stratified by disease status. Results The prevalence of CAD was 39% (36 of 92) according to QCA and SPECT and 64% (59 of 92) according to QCA alone. When compared with QCA and SPECT, per-patient diagnostic accuracy of perfusion CT and perfusion MR imaging was 63% (58 of 92) and 75% (69 of 92), respectively (P = .11); sensitivity was 92% (33 of 36) and 83% (30 of 36), respectively (P = .45); and specificity was 45% (25 of 56) and 70% (39 of 56), respectively (P CT perfusion and MR perfusion imaging was 82% (75 of 92) and 74% (68 of 92), respectively (P = .27); sensitivity was 90% (53 of 59) and 69% (41 of 59), respectively (P perfusion CT is similar to that of perfusion MR imaging in the detection of CAD. © RSNA, 2017 Online supplemental material is available for this article.

  2. Does routine pressure wire assessment influence management strategy at coronary angiography for diagnosis of chest pain? The RIPCORD Study

    OpenAIRE

    Curzen, Nick; Rana, Omar; Nicholas, Zoe; Golledge, Peter; Zaman, Azfar; Oldroyd, Keith; Hanratty, Colm; Banning, Adrian; Wheatcroft, Stephen; Hobson, Alex; Chitkara, Kam; Hildick-Smith, David; McKenzie, Dan; Calver, Alison; Dimitrov, Borislav D.

    2014-01-01

    Background — The use of coronary angiography (CA) for diagnosis and management of chest pain (CP) has several flaws. The assessment of coronary artery disease using fractional flow reserve (FFR) is a well-validated technique for describing lesion-level ischemia and improves clinical outcome in the context of percutaneous coronary intervention. The impact of routine FFR at the time of diagnostic CA on patient management has not been determined.Method and Results — Two hundred patients with sta...

  3. Assessment of injection bolus in first-pass radionuclide angiography. Evaluation of injection site and needle size

    International Nuclear Information System (INIS)

    Tonami, Syuichi; Inagaki, Syoichi; Yasui, Masakazu; Sugishita, Kouki; Yoshita, Hisashi; Nakamura, Mamoru; Kuranishi, Makoto

    1996-01-01

    First-pass radionuclide angiography (FPRNA) using a multi-crystal gamma camera can correctly provide many quantitative and qualitative indices of left ventricular function as well as anatomic information. A compact injection bolus of radiotracer is, however, essential to the first-pass study since the temporal separation of cardiac chambers is required for the first-pass acquisition. To examine which factors affect the quality of an injection bolus, 327 patients who had FPRNA in the anterior projection were randomized for injection site of radiotracer (right or left external jugular veins, and right antecubital vein) and needle size (19- or 21-gauge). The injected bolus was assessed from the full width at half maximum (FWHM) of the bolus time-activity curve in the superior vena cava. As to injection site using a 19-gauge needle, an attemption through right external jugular vein (EJV) revealed the shortest FWHM of an injection bolus, followed by left EJV and right antecubital vein (AV). In right EJV 91% of injected bolus FWHM was less than 1.5 sec, which was significantly higher (p<0.001) than those of the other sites (left EJV: 70%. right AV: 65%). Approximately 7% of injection from left EJV and right AV, showed a split bolus of radiotracer. However, no split bolus was observed from right EJV. There was no significant difference in FWHM of an injection bolus between 19- and 21-gauge needle from EJV. Our present study demonstrated that the quality of an injection bolus from left EJV and AV was affected by RVEF in a case of low right ventricular function. In conclusion, right EJV is the first choice of injection site to obtain a compact bolus of radiotracer for the first-pass cardiac study. A 21-gauge needle can also be inserted from the external jugular vein to perform a good bolus injection. (author)

  4. Assessment of injection bolus in first-pass radionuclide angiography. Evaluation of injection site and needle size

    Energy Technology Data Exchange (ETDEWEB)

    Tonami, Syuichi; Inagaki, Syoichi; Yasui, Masakazu; Sugishita, Kouki; Yoshita, Hisashi; Nakamura, Mamoru; Kuranishi, Makoto [Toyama Medical and Pharmaceutical Univ. (Japan). Hospital

    1996-09-01

    First-pass radionuclide angiography (FPRNA) using a multi-crystal gamma camera can correctly provide many quantitative and qualitative indices of left ventricular function as well as anatomic information. A compact injection bolus of radiotracer is, however, essential to the first-pass study since the temporal separation of cardiac chambers is required for the first-pass acquisition. To examine which factors affect the quality of an injection bolus, 327 patients who had FPRNA in the anterior projection were randomized for injection site of radiotracer (right or left external jugular veins, and right antecubital vein) and needle size (19- or 21-gauge). The injected bolus was assessed from the full width at half maximum (FWHM) of the bolus time-activity curve in the superior vena cava. As to injection site using a 19-gauge needle, an attemption through right external jugular vein (EJV) revealed the shortest FWHM of an injection bolus, followed by left EJV and right antecubital vein (AV). In right EJV 91% of injected bolus FWHM was less than 1.5 sec, which was significantly higher (p<0.001) than those of the other sites (left EJV: 70%. right AV: 65%). Approximately 7% of injection from left EJV and right AV, showed a split bolus of radiotracer. However, no split bolus was observed from right EJV. There was no significant difference in FWHM of an injection bolus between 19- and 21-gauge needle from EJV. Our present study demonstrated that the quality of an injection bolus from left EJV and AV was affected by RVEF in a case of low right ventricular function. In conclusion, right EJV is the first choice of injection site to obtain a compact bolus of radiotracer for the first-pass cardiac study. A 21-gauge needle can also be inserted from the external jugular vein to perform a good bolus injection. (author)

  5. Correlation between dual-axis rotational coronary angiography and intravascular ultrasound in a coronary lesion assessment.

    Science.gov (United States)

    Jin, Zhi-Geng; Zhang, Zhuo-Qi; Jing, Li-Min; Wei, Yu-Jie; Zhang, Jiao; Luo, Jian-Ping; Yang, Sheng-Li; Ma, Dong-Xing; Liu, Ying; Han, Wei; Yang, Yong; Liu, Hui-Liang

    2017-02-01

    The purpose of this study was to evaluate the accuracy of dual-axis rotational coronary angiography (DARCA) for coronary lesion assessment by directly comparing with intravascular ultrasound (IVUS). From October 2014 to December 2015, 40 patients (58 lesions) who had undergone both DARCA and IVUS were included in the image analysis. The minimum lumen diameter (MLD), lesion length, reference vessel diameter (RVD) and percent diameter stenosis at the same lesion, were identified and assessed. Significant correlation with IVUS was found for DARCA in either lesion length (r = 0.90, P < 0.001) or RVD (r = 0.81, P < 0.001) comparison. DARCA had fair correlation with IVUS for both MLD (r = 0.65, P < 0.001) and diameter stenosis (r = 0.48, P < 0.001). From the Bland-Altman plots, there was a good agreement between DARCA and IVUS regarding MLD (mean difference: -0.23 mm, 95 % limits of agreement: -0.96 to 0.50 mm) and RVD (mean difference: -0.15 mm, 95 % limits of agreement: -0.85 to 0.55 mm), while lesser agreement was found on lesion length (mean difference: -3.39 mm, 95 % limits of agreement: -12.63 to 5.85 mm) and diameter stenosis (mean difference: 4.82 %, 95 % limits of agreement: -17.05 to 26.68 %). There is an adequate correlation and agreement between DARCA and IVUS in coronary lesion assessment.

  6. Response of left ventricular volume to exercise in man assessed by radionuclide equilibrium angiography

    International Nuclear Information System (INIS)

    Slutsky, R.; Karliner, J.; Ricci, D.; Schuler, G.; Pfisterer, M.; Peterson, K.; Ashburn, W.

    1979-01-01

    To assess the effects of exercise on left ventricular volumes we studied 10 normal men, 15 patients with coronary disease who developed angina pectoris during exercise, and 10 patients with known coronary disease who did not develop angina during exercise. Each subject performed supine bicycle exercise under a mobile, single-crystal scintillation camera until angina or fatigue occurred. Technetium-99m bound to human serum albumin was the imaging agent. Data were collected at rest and during the last 2 minutes of each 3-minute stage of exercise and for 10 minutes after exercise. Volumes were calculated by a new radionuclide technique that correlated well with cineangiography and is expressed in nondimensional units. In normal subjects, the end-diastolic volume (EDV) at rest was not different from that a peak exercise. The end-systolic volume (ESV) decreased at peak exercise. ESV decreased progressively in all but two of 30 exercise periods. Angina patients had a larger EDV at rest and during chest pain than normals. Angina patients increased their ESV during chest pain resulting in a decreased ejection fraction (EF). All angina patients had a higher ESV during chest pain than during the exercise stage before chest pain. As a group, patients who did not develop angina had a lower EDV at rest and peak exercise than those who did develop angina. We conclude: that the EF increases during exercise due to a decrease in ESV; that the EF in patients with angina decreases because of an increase in ESV; and that the EF in coronary disease patients without angina shows no change because there is no significant change in the ESV. Radionuclide equilibrium angiography may prove useful for assessing EF and volume changes in patients with coronary artery disease

  7. Catheter Angiography

    Medline Plus

    Full Text Available Toggle navigation Test/Treatment Patient Type Screening/Wellness Disease/Condition Safety En Español More Info Images/Videos About Us News Physician Resources Professions Site Index A-Z Catheter Angiography Catheter angiography ...

  8. Catheter Angiography

    Medline Plus

    Full Text Available ... imaging technologies and, in most cases, a contrast material injection is needed to produce pictures of blood vessels in the body. Angiography is performed using: x-rays with catheters computed tomography (CT) magnetic resonance imaging (MRI) In catheter angiography, a thin ...

  9. Catheter Angiography

    Medline Plus

    Full Text Available ... further information please consult the ACR Manual on Contrast Media and its references. The risk of serious allergic ... View full size with caption Related Articles and Media Angioplasty and Vascular Stenting MR Angiography (MRA) Contrast Materials CT Angiography (CTA) X-ray, Interventional Radiology ...

  10. Catheter Angiography

    Medline Plus

    Full Text Available Toggle navigation Test/Treatment Patient Type Screening/Wellness Disease/Condition Safety En Español More Info Images/Videos About Us News Physician ... Catheter Angiography? Angiography is a minimally invasive medical test that helps physicians diagnose and treat medical conditions. ...

  11. Observer reliability of CT angiography in the assessment of acute ischaemic stroke: data from the Third International Stroke Trial

    Energy Technology Data Exchange (ETDEWEB)

    Mair, Grant; Farrall, Andrew J.; Sellar, Robin J.; Mollison, Daisy; Sakka, Eleni; Palmer, Jeb; Wardlaw, Joanna M. [University of Edinburgh, Western General Hospital, Division of Neuroimaging Sciences, Edinburgh (United Kingdom); Kummer, Ruediger von [Dresden University Stroke Centre, University Hospital, Department of Neuroradiology, Dresden (Germany); Adami, Alessandro [Sacro Cuore-Don Calabria Hospital, Stroke Center, Department of Neurology, Negrar (Italy); White, Philip M. [Stroke Research Group, Newcastle upon Tyne (United Kingdom); Adams, Matthew E. [National Hospital for Neurology and Neurosurgery, Department of Neuroradiology, London (United Kingdom); Yan, Bernard [Royal Melbourne Hospital, Neurovascular Research Group, Parkville (Australia); Demchuk, Andrew M. [Calgary Stroke Program, Department of Clinical Neurosciences, Calgary (Canada); Ramaswamy, Rajesh; Rodrigues, Mark A.; Samji, Karim; Baird, Andrew J. [Royal Infirmary of Edinburgh, Department of Radiology, Edinburgh (United Kingdom); Boyd, Elena V. [Northwick Park Hospital, Department of Radiology, Harrow (United Kingdom); Cohen, Geoff; Perry, David; Sandercock, Peter A.G. [University of Edinburgh, Western General Hospital, Division of Clinical Neurosciences, Edinburgh (United Kingdom); Lindley, Richard [University of Sydney, Westmead Hospital Clinical School and The George Institute for Global Health, Sydney (Australia); Collaboration: The IST-3 Collaborative Group

    2014-10-07

    CT angiography (CTA) is often used for assessing patients with acute ischaemic stroke. Only limited observer reliability data exist. We tested inter- and intra-observer reliability for the assessment of CTA in acute ischaemic stroke. We selected 15 cases from the Third International Stroke Trial (IST-3, ISRCTN25765518) with various degrees of arterial obstruction in different intracranial locations on CTA. To assess inter-observer reliability, seven members of the IST-3 expert image reading panel (>5 years experience reading CTA) and seven radiology trainees (<2 years experience) rated all 15 scans independently and blind to clinical data for: presence (versus absence) of any intracranial arterial abnormality (stenosis or occlusion), severity of arterial abnormality using relevant scales (IST-3 angiography score, Thrombolysis in Cerebral Infarction (TICI) score, Clot Burden Score), collateral supply and visibility of a perfusion defect on CTA source images (CTA-SI). Intra-observer reliability was assessed using independently repeated expert panel scan ratings. We assessed observer agreement with Krippendorff's-alpha (K-alpha). Among experienced observers, inter-observer agreement was substantial for the identification of any angiographic abnormality (K-alpha = 0.70) and with an angiography assessment scale (K-alpha = 0.60-0.66). There was less agreement for grades of collateral supply (K-alpha = 0.56) or for identification of a perfusion defect on CTA-SI (K-alpha = 0.32). Radiology trainees performed as well as expert readers when additional training was undertaken (neuroradiology specialist trainees). Intra-observer agreement among experts provided similar results (K-alpha = 0.33-0.72). For most imaging characteristics assessed, CTA has moderate to substantial observer agreement in acute ischaemic stroke. Experienced readers and those with specialist training perform best. (orig.)

  12. Observer reliability of CT angiography in the assessment of acute ischaemic stroke: data from the Third International Stroke Trial

    International Nuclear Information System (INIS)

    Mair, Grant; Farrall, Andrew J.; Sellar, Robin J.; Mollison, Daisy; Sakka, Eleni; Palmer, Jeb; Wardlaw, Joanna M.; Kummer, Ruediger von; Adami, Alessandro; White, Philip M.; Adams, Matthew E.; Yan, Bernard; Demchuk, Andrew M.; Ramaswamy, Rajesh; Rodrigues, Mark A.; Samji, Karim; Baird, Andrew J.; Boyd, Elena V.; Cohen, Geoff; Perry, David; Sandercock, Peter A.G.; Lindley, Richard

    2015-01-01

    CT angiography (CTA) is often used for assessing patients with acute ischaemic stroke. Only limited observer reliability data exist. We tested inter- and intra-observer reliability for the assessment of CTA in acute ischaemic stroke. We selected 15 cases from the Third International Stroke Trial (IST-3, ISRCTN25765518) with various degrees of arterial obstruction in different intracranial locations on CTA. To assess inter-observer reliability, seven members of the IST-3 expert image reading panel (>5 years experience reading CTA) and seven radiology trainees (<2 years experience) rated all 15 scans independently and blind to clinical data for: presence (versus absence) of any intracranial arterial abnormality (stenosis or occlusion), severity of arterial abnormality using relevant scales (IST-3 angiography score, Thrombolysis in Cerebral Infarction (TICI) score, Clot Burden Score), collateral supply and visibility of a perfusion defect on CTA source images (CTA-SI). Intra-observer reliability was assessed using independently repeated expert panel scan ratings. We assessed observer agreement with Krippendorff's-alpha (K-alpha). Among experienced observers, inter-observer agreement was substantial for the identification of any angiographic abnormality (K-alpha = 0.70) and with an angiography assessment scale (K-alpha = 0.60-0.66). There was less agreement for grades of collateral supply (K-alpha = 0.56) or for identification of a perfusion defect on CTA-SI (K-alpha = 0.32). Radiology trainees performed as well as expert readers when additional training was undertaken (neuroradiology specialist trainees). Intra-observer agreement among experts provided similar results (K-alpha = 0.33-0.72). For most imaging characteristics assessed, CTA has moderate to substantial observer agreement in acute ischaemic stroke. Experienced readers and those with specialist training perform best. (orig.)

  13. Quantitative wear particle analysis for osteoarthritis assessment.

    Science.gov (United States)

    Guo, Meizhai; Lord, Megan S; Peng, Zhongxiao

    2017-12-01

    Osteoarthritis is a degenerative joint disease that affects millions of people worldwide. The aims of this study were (1) to quantitatively characterise the boundary and surface features of wear particles present in the synovial fluid of patients, (2) to select key numerical parameters that describe distinctive particle features and enable osteoarthritis assessment and (3) to develop a model to assess osteoarthritis conditions using comprehensive wear debris information. Discriminant analysis was used to statistically group particles based on differences in their numerical parameters. The analysis methods agreed with the clinical osteoarthritis grades in 63%, 50% and 61% of particles for no osteoarthritis, mild osteoarthritis and severe osteoarthritis, respectively. This study has revealed particle features specific to different osteoarthritis grades and provided further understanding of the cartilage degradation process through wear particle analysis - the technique that has the potential to be developed as an objective and minimally invasive method for osteoarthritis diagnosis.

  14. Factors associated with coronary artery disease progression assessed by serial coronary computed tomography angiography

    Energy Technology Data Exchange (ETDEWEB)

    Camargo, Gabriel Cordeiro; Gottlieb, Ilan, E-mail: ilangottlieb@gmail.com [Casa de Saúde São José, Rio de Janeiro, RJ (Brazil); Rothstein, Tamara; Derenne, Maria Eduarda; Sabioni, Leticia; Lima, Ronaldo de Souza Leão [Centro de Diagnóstico por Imagem CDPI, Rio de Janeiro, RJ (Brazil); Lima, João A. C. [Johns Hopkins University, Baltimore (United States)

    2017-05-15

    Background: Coronary computed tomography angiography (CCTA) allows for noninvasive coronary artery disease (CAD) phenotyping. Factors related to CAD progression are epidemiologically valuable. Objective: To identify factors associated with CAD progression in patients undergoing sequential CCTA testing. Methods: We retrospectively analyzed 384 consecutive patients who had at least two CCTA studies between December 2005 and March 2013. Due to limitations in the quantification of CAD progression, we excluded patients who had undergone surgical revascularization previously or percutaneous coronary intervention (PCI) between studies. CAD progression was defined as any increase in the adapted segment stenosis score (calculated using the number of diseased segments and stenosis severity) in all coronary segments without stent (in-stent restenosis was excluded from the analysis). Stepwise logistic regression was used to assess variables associated with CAD progression. Results: From a final population of 234 patients, a total of 117 (50%) had CAD progression. In a model accounting for major CAD risk factors and other baseline characteristics, only age (odds ratio [OR] 1.04, 95% confidence interval [95%CI] 1.01–1.07), interstudy interval (OR 1.03, 95%CI 1.01–1.04), and past PCI (OR 3.66, 95%CI 1.77–7.55) showed an independent relationship with CAD progression. Conclusions: A history of PCI with stent placement was independently associated with a 3.7-fold increase in the odds of CAD progression, excluding in-stent restenosis. Age and interstudy interval were also independent predictors of progression. (author)

  15. Accuracy of CT angiography in the assessment of the circle of Willis: comparison of volume-rendered images and digital subtraction angiography

    Energy Technology Data Exchange (ETDEWEB)

    Han, Ari; Yoon, Dae Young; Chang, Suk Ki (Dept. of Radiology, Kangdong Seong-Sim Hospital, Hallym Univ. College of Medicine, Seoul (Korea, Republic of)), email: evee0914@chollian.net; Lim, Kyoung Ja (Dept. of Radiology, Kangdong Seong-Sim Hospital, Hallym Univ. College of Medicine, Seoul (Korea, Republic of); Dept. of Radiology, Kangwon National Univ. College of Medicine, Chuncheon, Kangwon-do (Korea, Republic of)); Cho, Byung-Moon (Dept. of Neurosurgery, Kangdong Seong-Sim Hospital, Hallym Univ. College of Medicine, Seoul (Korea, Republic of)); Shin, Yoon Cheol (Dept. of Thoracic Surgery, Kangdong Seong-Sim Hospital, Hallym Univ. College of Medicine, Seoul (Korea, Republic of)); Kim, Sam Soo (Dept. of Radiology, Kangwon National Univ. College of Medicine, Chuncheon, Kangwon-do (Korea, Republic of)); Kim, Keon Ha (Dept. of Radiology, Samsung Medical Center, Sungkyunkwan Univ. College of Medicine, Seoul (Korea, Republic of))

    2011-10-15

    Background Computed tomography angiography (CTA) is increasingly used for non-invasive imaging of the cerebrovascular diseases. Purpose To evaluate the accuracy of CTA in the assessment of the variation of the segment calibers of the circle of Willis. Material and Methods One hundred and 17 patients with acute SAH (51 men and 66 women, mean age 50.9 years) who underwent CTA using a 16 detector-row CT scanner and DSA were evaluated retrospectively. The CTA and DSA studies were performed within 24 h after the onset of symptoms and within 24 h of each other. A total of 819 arterial segments (A-comA, right and left A1 segment, right and left P-com A, and right and left P1 segment) of the circle of Willis were determined to be aplastic (grade 1), hypoplastic (grade 2), or normal-sized (grade 3) by blinded observers evaluating CTA volume-rendered images. The CTA results were then compared with findings on the corresponding DSA images (reference standard). Results The overall agreement between CTA and DSA was 92.4%. We had 62 (7.6%) cases of disagreement (58 cases of under-estimation and four cases of over-estimation by CTA) between tow modalities. The sensitivity and specificity of CTA in the detection of aplastic and normal-sized segments were more than 90%. In contrast, subgroup analysis of the hypoplastic segments showed a sensitivity of 52.6% and a specificity of 98.2%. Conclusion CTA is highly accurate in the assessment of anatomical variations of the circle of Willis; however, its sensitivity is limited in depicting hypoplastic segments

  16. Flat Panel Angiography in the Cross-Sectional Imaging of the Temporal Bone: Assessment of Image Quality and Radiation Dose Compared with a 64-Section Multisection CT Scanner.

    Science.gov (United States)

    Conte, G; Scola, E; Calloni, S; Brambilla, R; Campoleoni, M; Lombardi, L; Di Berardino, F; Zanetti, D; Gaini, L M; Triulzi, F; Sina, C

    2017-10-01

    Cross-sectional imaging of the temporal bone is challenging because of the complexity and small dimensions of the anatomic structures. We evaluated the role of flat panel angiography in the cross-sectional imaging of the temporal bone by comparing its image quality and radiation dose with a 64-section multisection CT scanner. We retrospectively collected 29 multisection CT and 29 flat panel angiography images of normal whole-head temporal bones. Image quality was assessed by 2 neuroradiologists, who rated the visualization of 30 anatomic structures with a 3-point ordinal scale. The radiation dose was assessed with an anthropomorphic phantom. Flat panel angiography showed better image quality than multisection CT in depicting the anterior and posterior crura of the stapes, the footplate of the stapes, the stapedius muscle, and the anterior ligament of the malleus ( P panel angiography in assessing the tympanic membrane, the bone marrow of the malleus and incus, the tendon of the tensor tympani, the interscalar septum, and the modiolus of the cochlea ( P panel angiography had a significantly higher overall image quality rating than multisection CT ( P = .035). A reduction of the effective dose of approximately 40% was demonstrated for flat panel angiography compared with multisection CT. Flat panel angiography shows strengths and weaknesses compared with multisection CT. It is more susceptible to artifacts, but due to the higher spatial resolution, it shows equal or higher image quality in assessing some bony structures of diagnostic interest. The lower radiation dose is an additional advantage of flat panel angiography. © 2017 by American Journal of Neuroradiology.

  17. Relationship between coronary contrast-flow quantitative flow ratio and myocardial ischemia assessed by SPECT MPI

    Energy Technology Data Exchange (ETDEWEB)

    Smit, Jeff M.; Rosendael, Alexander R. van; Jukema, J.W.; Delgado, Victoria; Bax, Jeroen J.; Scholte, Arthur J. [Leiden University Medical Center, Department of Cardiology, Leiden (Netherlands); Koning, Gerhard [Medis Medical Imaging Systems B.V., Leiden (Netherlands); Dibbets-Schneider, Petra [Leiden University Medical Center, Department of Nuclear Medicine, Leiden (Netherlands); Mertens, Bart J. [Leiden University Medical Center, Department of Medical Statistics, Leiden (Netherlands); Reiber, Johan H.C. [Medis Medical Imaging Systems B.V., Leiden (Netherlands); Leiden University Medical Center, Department of Radiology, Leiden (Netherlands)

    2017-10-15

    A new method has been developed to calculate fractional flow reserve (FFR) from invasive coronary angiography, the so-called ''contrast-flow quantitative flow ratio (cQFR)''. Recently, cQFR was compared to invasive FFR in intermediate coronary lesions showing an overall diagnostic accuracy of 85%. The purpose of this study was to investigate the relationship between cQFR and myocardial ischemia assessed by single-photon emission computed tomography myocardial perfusion imaging (SPECT MPI). Patients who underwent SPECT MPI and coronary angiography within 3 months were included. The cQFR computation was performed offline, using dedicated software. The cQFR computation was based on 3-dimensional quantitative coronary angiography (QCA) and computational fluid dynamics. The standard 17-segment model was used to determine the vascular territories. Myocardial ischemia was defined as a summed difference score ≥2 in a vascular territory. A cQFR of ≤0.80 was considered abnormal. Two hundred and twenty-four coronary arteries were analysed in 85 patients. Overall accuracy of cQFR to detect ischemia on SPECT MPI was 90%. In multivariable analysis, cQFR was independently associated with ischemia on SPECT MPI (OR per 0.01 decrease of cQFR: 1.10; 95% CI 1.04-1.18, p = 0.002), whereas clinical and QCA parameters were not. Furthermore, cQFR showed incremental value for the detection of ischemia compared to clinical and QCA parameters (global chi square 48.7 to 62.6; p <0.001). A good relationship between cQFR and SPECT MPI was found. cQFR was independently associated with ischemia on SPECT MPI and showed incremental value to detect ischemia compared to clinical and QCA parameters. (orig.)

  18. Assessment of single vessel coronary artery disease: results of exercise electrocardiography, thallium-201 myocardial perfusion imaging and radionuclide angiography

    International Nuclear Information System (INIS)

    Port, S.C.; Oshima, M.; Ray, G.; McNamee, P.; Schmidt, D.H.

    1985-01-01

    The sensitivity of the commonly used stress tests for the diagnosis of coronary artery disease was analyzed in 46 patients with significant occlusion (greater than or equal to 70% luminal diameter obstruction) of only one major coronary artery and no prior myocardial infarction. In all patients, thallium-201 perfusion imaging (both planar and seven-pinhole tomographic) and 12 lead electrocardiography were performed during the same graded treadmill exercise test and radionuclide angiography was performed during upright bicycle exercise. Exercise rate-pressure (double) product was 22,307 +/- 6,750 on the treadmill compared with 22,995 +/- 5,622 on the bicycle (p = NS). Exercise electrocardiograms were unequivocally abnormal in 24 patients (52%). Qualitative planar thallium images were abnormal in 42 patients (91%). Quantitative analysis of the tomographic thallium images were abnormal in 41 patients (89%). An exercise ejection fraction of less than 0.56 or a new wall motion abnormality was seen in 30 patients (65%). Results were similar for the right (n = 11) and left anterior descending (n = 28) coronary arteries while all tests but the planar thallium imaging showed a lower sensitivity for isolated circumflex artery disease (n = 7). The specificity of the tests was 72, 83, 89 and 72% for electrocardiography, planar thallium imaging, tomographic thallium imaging and radionuclide angiography, respectively. The results suggest that exercise thallium-201 perfusion imaging is the most sensitive noninvasive stress test for the diagnosis of single vessel coronary artery disease

  19. Catheter Angiography

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    Full Text Available ... spaghetti. top of page How does the procedure work? Catheter angiography works much the same as a ... and x-rays. Manufacturers of intravenous contrast indicate mothers should not breastfeed their babies for 24-48 ...

  20. Catheter Angiography

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    Full Text Available ... medical conditions. Angiography uses one of three imaging technologies and, in most cases, a contrast material injection ... a tendency to bleed. top of page Additional Information and Resources Society of Interventional Radiology (SIR) - Patient ...

  1. Catheter Angiography

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    Full Text Available ... examine blood vessels in key areas of the body for abnormalities such as aneurysms and disease such ... to produce pictures of blood vessels in the body. Angiography is performed using: x-rays with catheters ...

  2. Catheter Angiography

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    Full Text Available ... medical conditions. Angiography uses one of three imaging technologies and, in most cases, a contrast material injection ... identify a small aneurysm or arteriovenous malformation (abnormal communications between blood vessels) inside the brain or other ...

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    Full Text Available ... physicians diagnose and treat medical conditions. Angiography uses one of three imaging technologies and, in most cases, ... evaluating a stent after implantation. detect injury to one or more arteries in the neck, chest, abdomen, ...

  4. Catheter Angiography

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    Full Text Available ... the body for abnormalities such as aneurysms and disease such as atherosclerosis (plaque). The use of a catheter makes it possible to combine diagnosis and treatment in a single procedure. Catheter angiography ...

  5. Catheter Angiography

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    Full Text Available ... Survey Do you have a personal story about radiology? Share your patient story here Images × Image Gallery ... Contrast Materials CT Angiography (CTA) X-ray, Interventional Radiology and Nuclear Medicine Radiation Safety Images related to ...

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    Full Text Available ... medical conditions. Angiography uses one of three imaging technologies and, in most cases, a contrast material injection ... that might interfere with the x-ray images. Women should always inform their physician and x-ray ...

  7. Catheter Angiography

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    Full Text Available ... the body absorb the x-rays in varying degrees. Dense bone absorbs much of the radiation while ... by angioplasty and placement of a stent . The degree of detail displayed by catheter angiography may not ...

  8. Catheter Angiography

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    Full Text Available ... medical conditions. Angiography uses one of three imaging technologies and, in most cases, a contrast material injection ... are a form of radiation like light or radio waves. X-rays pass through most objects, including ...

  9. Catheter Angiography

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    Full Text Available ... rays ). top of page What are some common uses of the procedure? Catheter angiography is used to ... Society of Urogenital Radiology note that the available data suggest that it is safe to continue breastfeeding ...

  10. Catheter Angiography

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    Full Text Available ... View full size with caption Related Articles and Media Angioplasty and Vascular Stenting MR Angiography (MRA) Contrast ... or your insurance provider to get a better understanding of the possible charges you will incur. Web ...

  11. Catheter Angiography

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    Full Text Available ... spaghetti. top of page How does the procedure work? Catheter angiography works much the same as a ... material injection, you should immediately inform the technologist. Women should always inform their physician or x-ray ...

  12. Catheter Angiography

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    Full Text Available ... blood flow to the brain and cause a stroke. identify a small aneurysm or arteriovenous malformation (abnormal ... you. top of page What are the benefits vs. risks? Benefits Angiography may eliminate the need for ...

  13. Catheter Angiography

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    Full Text Available ... of a catheter makes it possible to combine diagnosis and treatment in a single procedure. Catheter angiography ... of a catheter makes it possible to combine diagnosis and treatment in a single procedure. An example ...

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    Full Text Available ... diagnosis and treatment in a single procedure. An example is finding an area of severe arterial narrowing, ... contrast material, your radiologist may advise that you take special medication for 24 hours before catheter angiography ...

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    Full Text Available ... identify a small aneurysm or arteriovenous malformation (abnormal communications between blood vessels) inside the brain or other ... iodine. If angiography is essential, a variety of methods is used to decrease risk of allergy: You ...

  16. Catheter Angiography

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    Full Text Available ... in patients after trauma. evaluate arteries feeding a tumor prior to surgery or other procedures such as ... supplying a small area of tissue or a tumor; this is called superselective angiography. Unlike computed tomography ( ...

  17. Catheter Angiography

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    Full Text Available ... with you. top of page What are the benefits vs. risks? Benefits Angiography may eliminate the need for surgery. If ... cancer from excessive exposure to radiation. However, the benefit of an accurate diagnosis far outweighs the risk. ...

  18. Catheter Angiography

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    Full Text Available ... medical conditions. Angiography uses one of three imaging technologies and, in most cases, a contrast material injection ... branches. show the extent and severity of the effects of coronary artery disease and plan for a ...

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  20. Catheter Angiography

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    Full Text Available ... disease). evaluate obstructions of vessels. top of page How should I prepare? You should inform your physician ... as a strand of spaghetti. top of page How does the procedure work? Catheter angiography works much ...

  1. Catheter Angiography

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    Full Text Available ... pictures of the blood vessels and may eliminate the need for surgery. Tell your doctor if there's a ... the benefits vs. risks? Benefits Angiography may eliminate the need for surgery. If surgery remains necessary, it can ...

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  4. Catheter Angiography

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  5. Catheter Angiography

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    Full Text Available ... serious allergic reaction to contrast materials that contain iodine is extremely rare, and radiology departments are well- ... having a reaction to contrast materials that contain iodine. If angiography is essential, a variety of methods ...

  6. Quantitative risk assessment of drinking water contaminants

    International Nuclear Information System (INIS)

    Cothern, C.R.; Coniglio, W.A.; Marcus, W.L.

    1986-01-01

    The development of criteria and standards for the regulation of drinking water contaminants involves a variety of processes, one of which is risk estimation. This estimation process, called quantitative risk assessment, involves combining data on the occurrence of the contaminant in drinking water and its toxicity. The human exposure to a contaminant can be estimated from occurrence data. Usually the toxicity or number of health effects per concentration level is estimated from animal bioassay studies using the multistage model. For comparison, other models will be used including the Weibull, probit, logit and quadratic ones. Because exposure and toxicity data are generally incomplete, assumptions need to be made and this generally results in a wide range of certainty in the estimates. This range can be as wide as four to six orders of magnitude in the case of the volatile organic compounds in drinking water and a factor of four to five for estimation of risk due to radionuclides in drinking water. As examples of the differences encountered in risk assessment of drinking water contaminants, discussions are presented on benzene, lead, radon and alachlor. The lifetime population risk estimates for these contaminants are, respectively, in the ranges of: <1 - 3000, <1 - 8000, 2000-40,000 and <1 - 80. 11 references, 1 figure, 1 table

  7. Role of 320-slice multislice computed tomography coronary angiography in the assessment of coronary artery stenosis

    Directory of Open Access Journals (Sweden)

    Mohamed Ahmed Youssef

    2014-06-01

    Conclusion: In conclusion, MSCT coronary angiography is a very helpful and rapid non-invasive coronary imaging modality that was able to detect and grade coronary artery stenosis better than other noninvasive examinations used to detect CAD, such as exercise stress testing. Due to its very high negative predictive value, it may eliminate the need for invasive coronary procedures in the presence of normal coronary imaging.

  8. Intracranial aneurysm segmentation in 3D CT angiography: Method and quantitative validation with and without prior noise filtering

    International Nuclear Information System (INIS)

    Firouzian, Azadeh; Manniesing, Rashindra; Flach, Zwenneke H.; Risselada, Roelof; Kooten, Fop van; Sturkenboom, Miriam C.J.M.; Lugt, Aad van der; Niessen, Wiro J.

    2011-01-01

    Intracranial aneurysm volume and shape are important factors for predicting rupture risk, for pre-surgical planning and for follow-up studies. To obtain these parameters, manual segmentation can be employed; however, this is a tedious procedure, which is prone to inter- and intra-observer variability. Therefore there is a need for an automated method, which is accurate, reproducible and reliable. This study aims to develop and validate an automated method for segmenting intracranial aneurysms in Computed Tomography Angiography (CTA) data. Also, it is investigated whether prior smoothing improves segmentation robustness and accuracy. The proposed segmentation method is implemented in the level set framework, more specifically Geodesic Active Surfaces, in which a surface is evolved to capture the aneurysmal wall via an energy minimization approach. The energy term is composed of three different image features, namely; intensity, gradient magnitude and intensity variance. The method requires minimal user interaction, i.e. a single seed point inside the aneurysm needs to be placed, based on which image intensity statistics of the aneurysm are derived and used in defining the energy term. The method has been evaluated on 15 aneurysms in 11 CTA data sets by comparing the results to manual segmentations performed by two expert radiologists. Evaluation measures were Similarity Index, Average Surface Distance and Volume Difference. The results show that the automated aneurysm segmentation method is reproducible, and performs in the range of inter-observer variability in terms of accuracy. Smoothing by nonlinear diffusion with appropriate parameter settings prior to segmentation, slightly improves segmentation accuracy.

  9. Assessment of the image quality and diagnostic accuracy of coronary CT angiography: effect of sublingual administration of nitroglycerin

    International Nuclear Information System (INIS)

    Kang, Doo Kyung; Rho, Hyun Woo; Park, Kyung Joo; Choi, So Yeon

    2007-01-01

    We wanted to investigate the effect of sublingual nitroglycerin (NTG) on improving the image quality and diagnostic accuracy of coronary computed tomographic angiography (CTA) for detecting atherosclerosis and significant stenosis. We retrospectively assessed the data of 81 patients who underwent coronary CTA. Forty three patients underwent coronary CTA without medication (the non-administrated group), while 38 patients were given 0.6 mg NTG sublingually before coronary CTA (the administrated group). Image quality was assessed using a five-point grading scale. We evaluated the diagnostic performance of coronary CTA for assessing atherosclerosis and significant stenosis (≥ 50%) in the 42 patients who underwent invasive coronary angiography. The mean image-quality grades were 4.09 ± 0.72 and 4.50 ± 0.60 in the non-administrated and administrated groups, respectively (ρ 0.008). On the per-artery analysis, the accuracy percentages for detecting coronary CTA were 65 and 88% for atherosclerosis and 82 and 80% for significant stenosis in the non-administrated and administrated groups, respectively. On the per-patient analysis, the positive predictive values for coronary CTA were 80% and 100% for atherosclerosis and 77% and 88% for significant stenosis in the non-administrated and administrated groups, respectively. Coronary CTA with NTG administration improved the image quality. The accuracy of coronary CTA for detecting atherosclerosis was higher in the administrated group than in the non-administrated group

  10. MR angiography

    International Nuclear Information System (INIS)

    Masaryk, T.J.; Ross, J.S.

    1991-01-01

    This paper reports on preliminary research and recent clinical experience which indicates that MR angiography can play a role in routine scanning by providing useful information regarding the anatomy of the cerebral circulation. Used in conjunction with conventional spin-echo studies it may improve the overall sensitivity and specificity of MRI in a cost-effective fashion. It does not, however, replace conventional arteriography at this time for either extracranial or intracranial disease. The use of intravascular contrast agents with new fast-scan techniques also provides dynamic information regarding tissue perfusion in a fashion analogous to that of xenon CT. While this work is preliminary, and the exact agents and mathematical models have yet to be defined, the ability to perform parenchymal, angiographic, and physiologic imaging at a single setting is potentially very powerful. Clearly, the role of MR flow techniques deserves further investigation into possible technical refinements, so that accuracy relative to other diagnostic studies and impact upon patient management can be assessed in a meaningful way

  11. Quantitative angiography of the left anterior descending coronary artery: correlations with pressure gradient and results of exercise thallium scintigraphy

    NARCIS (Netherlands)

    W. Wijns (William); P.W.J.C. Serruys (Patrick); J.H.C. Reiber (Johan); M.J.B.M. van den Brand (Marcel); M.L. Simoons (Maarten); C.J. Kooijman; K. Balakumaran (Kulasekaram); P.G. Hugenholtz (Paul)

    1985-01-01

    textabstractTo evaluate, during cardiac catheterization, what constitutes a physiologically significant obstruction to blood flow in the human coronary system, computer-based quantitative analysis of coronary angiograms was performed on the angiograms of 31 patients with isolated disease of the

  12. Laser Gingival Retraction: A Quantitative Assessment

    Science.gov (United States)

    Krishna Ch, Vamsi; Gupta, Nidhi; Reddy, K. Mahendranadh; Sekhar, N. Chandra; Aditya, Venkata; Reddy, G.V.K. Mohan

    2013-01-01

    Background: Proper gingival retraction improves the prognosis of crowns and bridges with sub gingival finishlines.Use of lasers assists the operator to achieve proper retraction with good clinical results. Aims: The present study was intended to assess the amount of lateral gingival retraction achieved quantitatively by using diode lasers. Settings and Design: Study was carried on 20 patients attended to a dental institution that underwent root canal treatment and indicated for fabrication of crowns. Material and Methods: Gingival retraction was carried out on 20 teeth and elastomeric impressions were obtained. Models retrieved from the impressions were sectioned and the lateral distance between finish line and the marginal gingival was measured using tool makers microscope. Retraction was measured in mid buccal, mesio buccal and disto buccal regions. Statistical Analysis: The values obtained were used to calculate the mean lateral retraction in microns. Results: Mean retraction values of 399.5 μm, 445.5 μm and 422.5μm were obtained in mid buccal, mesio buccal and disto buccal regions respectively. Conclusions: Gingival Retraction achieved was closer to the thickness of sulcular epithelium and greater than the minimum required retraction of 200um. PMID:24086914

  13. Expert judgement models in quantitative risk assessment

    International Nuclear Information System (INIS)

    Rosqvist, T.; Tuominen, R.

    1999-01-01

    Expert judgement is a valuable source of information in risk management. Especially, risk-based decision making relies significantly on quantitative risk assessment, which requires numerical data describing the initiator event frequencies and conditional probabilities in the risk model. This data is seldom found in databases and has to be elicited from qualified experts. In this report, we discuss some modelling approaches to expert judgement in risk modelling. A classical and a Bayesian expert model is presented and applied to real case expert judgement data. The cornerstone in the models is the log-normal distribution, which is argued to be a satisfactory choice for modelling degree-of-belief type probability distributions with respect to the unknown parameters in a risk model. Expert judgements are qualified according to bias, dispersion, and dependency, which are treated differently in the classical and Bayesian approaches. The differences are pointed out and related to the application task. Differences in the results obtained from the different approaches, as applied to real case expert judgement data, are discussed. Also, the role of a degree-of-belief type probability in risk decision making is discussed

  14. Contribution of quantitative coronary angiography in Palmaz-Schatz optimal stent liberation strategy for subacute occlusion control; Contribuicao da angiografia coronaria quantitativa na estrategia de liberacao otima da endoprotese de Palmaz-Schatz para o controle da oclusao subaguda

    Energy Technology Data Exchange (ETDEWEB)

    Sousa, Amanda Guerra de Moraes Rego

    1995-07-01

    This study examines whether a single method, quantitative coronary angiography with automated edge detection, could efficiently guide optimal stent liberation, assuring good clinical results and eliminating the need for anticoagulation therapy. This investigation includes 101 patients with optimal implantation of 104 Palmaz-stents. Their mean age was 58.62 years and 79.2% were male. Most of them presented unstable angina (61.39%) and had single vessel disease (85.15%) The treated vessel was the left anterior descending artery in 39.60%; the right coronary artery in 34.66%; the left circumflex artery in 7.92% and saphenous vein grafts in 17.82%. The mean reference diameter of the target vessel was 3.43 mm. Each implantation comprehended two phases: initial stent liberation and additional high pressure balloon inflation, guided by quantitative coronary angiography. Arterial quantification showed an important increase in the mean luminal diameter (p<0.001), characterized by an immediate gain of 2.37 mm [standard deviation (SD): 0.55 m]. Quantitative angiography permitted to identify a further gain in the luminal diameter following the high pressure balloon inflation, o.49 mm 9 SD:0.53 mm). Therefore, the total mean immediate gain was 2.85 mm (SD:0.64 mm). The mean diameter stenosis changed from 80.21% (SD:14.56%) to 11.81% (SD: 7.59% - p<0.001) after initial stent delivery; and to 0.16% (SD:3.45% - p<,0.001), after high pressure balloon inflation. Quantitative coronary angiography performed detailed measurements of the minimal caliber variations along the entire prosthesis due to the high pressure balloon inflations, similarly to the intracoronary ultrasound. This guided the optimal stent implantation and helped the clinical management of these cases. In this series, even maintained only under antiaggregant agents, no patient presented major ischemic complications and only one (0.99%) had a hemorrhage in the puncture site that required blood transfusion. The mean in

  15. Quantitative Risk Assessment for Enhanced Geothermal Systems

    Science.gov (United States)

    Lowry, T. S.; McKenna, S. A.; Hadgu, T.; Kalinina, E.

    2011-12-01

    This study uses a quantitative risk-assessment approach to place the uncertainty associated with enhanced geothermal systems (EGS) development into meaningful context and to identify points of attack that can reduce risk the most. Using the integrated geothermal assessment tool, GT-Mod, we calculate the complimentary cumulative distribution function of the levelized cost of electricity (LCOE) that results from uncertainty in a variety of geologic and economic input parameter values. EGS is a developing technology that taps deep (2-10km) geologic heat sources for energy production by "enhancing" non-permeable hot rock through hydraulic stimulation. Despite the promise of EGS, uncertainties in predicting the physical end economic performance of a site has hindered its development. To address this, we apply a quantitative risk-assessment approach that calculates risk as the sum of the consequence, C, multiplied by the range of the probability, ΔP, over all estimations of a given exceedance probability, n, over time, t. The consequence here is defined as the deviation from the best estimate LCOE, which is calculated using the 'best-guess' input parameter values. The analysis assumes a realistic but fictitious EGS site with uncertainties in the exploration success rate, the sub-surface thermal gradient, the reservoir fracture pattern, and the power plant performance. Uncertainty in the exploration, construction, O&M, and drilling costs are also included. The depth to the resource is calculated from the thermal gradient and a target resource temperature of 225 °C. Thermal performance is simulated using the Gringarten analytical solution. The mass flow rate is set to produce 30 MWe of power for the given conditions and is adjusted over time to maintain that rate over the plant lifetime of 30 years. Simulations are conducted using GT-Mod, which dynamically links the physical systems of a geothermal site to simulate, as an integrated, multi-system component, the

  16. urrent status and assessment of quantitative and qualitative one leg ...

    African Journals Online (AJOL)

    ... of only a quantitative assessment. These findings indicate that, when evaluating the one leg balance in children aged 3-6 years, a quantitative and qualitative assessment should be used in combination together to assure a more accurate assessment. (S. African J. for Research in Sport, Physical Ed. and Recreation: 2001 ...

  17. Dynamic 3D-MR-angiography for assessing rheumatoid disease of the hand—A feasibility study

    International Nuclear Information System (INIS)

    Notohamiprodjo, Mike; Glaser, Christian; Horng, Annie; Helck, Andreas; Bauner, Kerstin U.; Reiser, Maximilian F.; Hatz, Hans J.; Weckbach, Sabine

    2012-01-01

    Purpose: To investigate highly temporally resolved MR-angiography (MRA) with time-resolved imaging with stochastic trajectories (TWIST) of the hand as supplementary tool for dynamic assessment of synovitis and vascular pathologies in rheumatoid diseases. Material and methods: A coronal dynamic TWIST–MRA-sequence (0.7 mm × 0.7 mm × 1.4 mm, temporal resolution 2.5 s, time of acquisition 4 min) of the predominantly affected hand of 17 patients with suspected rheumatoid disease was acquired after contrast administration (Multihance, Bracco Imaging SpA) at 3 T (Magnetom VERIO, 8-channel-knee-coil, Siemens Healthcare). As standard of reference, contrast enhanced non fat-saturated coronal and fat-saturated axial T1-w sequences were acquired. These static sequences and the dynamic TWIST–MRA–maximum-intensity-projections (MIP) were separately assessed by two readers in consensus, recording the number of synovial lesions (wrist, intercarpal, metacarpophaleangal/proximal/distal interphalangeal joints), signs of tenosynovitis and vasculitis. Diagnostic confidence was rated (4-point-scale: 4 = excellent; 1 = non-diagnostic). Statistical significance was tested using the Wilcoxon-rank-sum-test. Results: An insignificantly lower number of synovial lesions (n = 72 vs. 89; p = 0.1) and only 3/9 cases with tenosynovitis were identified by the TWIST–MRA. For detected lesions, diagnostic confidence was comparable (MRA: 3.64; static T1-w post contrast: 3.47). In patients with high clinical activity dynamic MRA showed very early synovial enhancement. Only dynamic MRA detected 3 cases of vasculitis (subsequently confirmed with digital-subtraction-angiography). Conclusion: TWIST–MRA facilitates fast detection of synovitis. Although dynamic MRA of the hand is inferior to static contrast enhanced sequences in assessing the number of synovitic and tenosynovitic lesions, its high temporal resolution allows for fast visual grading of disease activity and assessment of vasculitis

  18. Catheter Angiography

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    Full Text Available ... of a catheter makes it possible to combine diagnosis and treatment in a single procedure. Catheter angiography produces very ... of a catheter makes it possible to combine diagnosis and treatment in a single procedure. An example is finding ...

  19. Catheter Angiography

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    Full Text Available ... the equipment look like? How does the procedure work? How is the procedure performed? What will I experience during and after the procedure? Who interprets the results and how do I get them? What are the benefits vs. risks? What are the limitations of Catheter Angiography? What ...

  20. Catheter Angiography

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    Full Text Available ... small burst of radiation that passes through the body, recording an image on photographic film or a special detector. Different ... about radiology? Share your patient story here Images × ... Related Articles and Media Angioplasty and Vascular Stenting MR Angiography (MRA) Contrast ...

  1. Catheter Angiography

    Medline Plus

    Full Text Available ... spaghetti. top of page How does the procedure work? Catheter angiography works much the same as a regular x-ray ... any possibility that they are pregnant. See the Safety page for more information about pregnancy and x- ...

  2. Catheter Angiography

    Medline Plus

    Full Text Available ... stents or evaluating a stent after implantation. detect injury to one or more arteries in the neck, ... of the radiation while soft tissue, such as muscle, fat and organs, allow more of the ... is called superselective angiography. Unlike computed tomography ( ...

  3. Hemodynamic Change in Pulmonary Vein Stenosis after Radiofrequency Ablation: Assessment with Magnetic Resonance Angiography

    Energy Technology Data Exchange (ETDEWEB)

    Yun, Doyoung; Jung, Jung Im; Oh, Yong Seog; Youn, Ho Joong [Seoul St. Mary' s Hospital, College of Medicine, The Catholic University of Korea, Seoul (Korea, Republic of)

    2012-11-15

    We present a case of pulmonary vein (PV) stenosis after radio-frequency (RF) ablation, in which a hemodynamic change in the pulmonary artery was similar to that of congenital PV atresia on time-resolved contrast-enhanced magnetic resonance angiography (TR-MRA). A 48-year-old man underwent RF ablation due to atrial fibrillation. The patient subsequently complained of hemoptysis, dyspnea on exertion, and right chest pain. Right PV stenosis after catheter ablation was diagnosed through chest computed tomography and lung perfusion scan. Pulmonary TR-MRA revealed the pulmonary artery via systemic arterial collaterals and draining systemic collateral veins. On a velocity-encoded cine image, the flow direction of the right pulmonary artery was reversed in the diastolic phase and the left pulmonary artery demonstrated continuous forward flow throughout the cardiac cycle. These hemodynamic changes were similar to those seen in congenital unilateral PV atresia.

  4. The value of radionuclide angiography for risk assessment of patients following acute myocardial infarction

    International Nuclear Information System (INIS)

    Morris, K.G.

    1985-01-01

    Radionuclide angiography (RNA) is an accurate noninvasive method for the evaluation of left ventricular function at rest and exercise. Both the change in ejection fraction from rest to exercise and the exercise ejection fraction correlate with the severity of coronary artery disease and are more sensitive than ST-segment changes for detecting abnormalities due to exercise-induced myocardial ischemia. The amount of left ventricular dysfunction produced acutely by myocardial ischemia appears to vary linearly with the severity of ischemia produced. Thus rest and exercise RNA provide information noninvasively regarding both the severity of left ventricular dysfunction and the amount of potentially ischemic myocardium, two of the three major pathophysiologic mechanisms related to prognosis. It is reasonable to hypothesize that rest and exercise RNA may provide useful prognostic information concerning subsequent mortality and morbidity in survivors of acute myocardial infarction

  5. Left ventricular dimensions during isometric exercise in aortic valve incompetence assessed by M-mode echocardiography and gated equilibrium radionuclide angiography

    International Nuclear Information System (INIS)

    Groundstroem, K.; Huikuri, H.; Korhonen, U.; Ikaeheimo, M.; Torniainen, P.; Heikkilae, J.; Linnaluoto, M.; Takkunen, J.; Oulu Univ.; Oulu Univ.

    1989-01-01

    We compared M-mode echocardiographic and gated equilibrium radionuclide angiography assessment of the left ventricular (LV) dimensions at rest and during isometric exercise in 18 patients with chronic aortic valve incompetence. The two methods showed a satisfactory correlation when comparing LV size at rest and during exercise (LV end-diastolic dimension in echocardiography vs LV end-diastolic volume in radionuclide angiography, r=0.80, P<0.01 at rest and r=0.81, P<0.01 during exercise; LV end-systolic dimension in echocardiography vs LV end-systolic volume in radionuclide angiography, r=0.81, P<0.01 at rest and r=0.75; P<0.01 during exercise), but fractional shortening in echocardiography and ejection fraction in radionuclide angiography did not correlate (r=0.27, not significant (NS) at rest and r=0.34, NS during exercise). Thus echocardiography and radionuclide angiography describe LV dimensions at rest and during handgrip exercise in a similar fashion, documenting the concordance of these noninvasive methods to describe LV size in aortic incompetence at rest and during exercise. (orig.)

  6. Quantitative angiography of the left anterior descending coronary artery: correlations with pressure gradient and exercise thallium scintigraphy

    International Nuclear Information System (INIS)

    Reiber, J.H.C.; Serruys, P.W.; Slager, C.J.; Erasmus Univ., Rotterdam

    1986-01-01

    In order to evaluate during cardiac catheterization what constitutes a physiologically significant obstruction to blood flow in the human coronary system, computer based quantitative analysis of coronary angiograms was performed in 31 patients with isolated proximal left anterior descending coronary artery disease. The angiographic severity of the stenosis was compared with the transstenotic pressure gradient measured with the dilatation catheter during angioplasty and the results of exercise thallium scintigraphy. A curvilinear relation was found between the pressure gradient across the stenosis (normalized for the mean aortic pressure) and the residual minimal obstruction area (after subtracting the area of the angioplasty catheter). This relation was best fitted by the equation: normalized mean pressure gradient = a + b · log [obstruction area], r = 0.74. The measurements of the percent area stenosis (cut-off 80%) and of the transstenotic pressure gradient (cut-off 0.30) obtained at rest, correctly predicted the occurrence of thallium perfusion defects induced by exercise in 83% of the patients. (Auth.)

  7. Quantitative angiography of the left anterior descending coronary artery: correlations with pressure gradient and results of exercise thallium scintigraphy

    International Nuclear Information System (INIS)

    Wijns, W.; Serruys, P.W.; Reiber, J.H.; van den Brand, M.; Simoons, M.L.; Kooijman, C.J.; Balakumaran, K.; Hugenholtz, P.G.

    1985-01-01

    To evaluate, during cardiac catheterization, what constitutes a physiologically significant obstruction to blood flow in the human coronary system, computer-based quantitative analysis of coronary angiograms was performed on the angiograms of 31 patients with isolated disease of the proximal left anterior descending coronary artery. The angiographic severity of stenosis was compared with the transstenotic pressure gradient measured with the dilation catheter during angioplasty and with the results of exercise thallium scintigraphy. A curvilinear relationship was found between the pressure gradient across the stenosis (normalized for the mean aortic pressure) and the residual minimal area of obstruction (after subtracting the area of the angioplasty catheter). This relationship was best fitted by the equation: normalized mean pressure gradient . a + b . log [obstruction area], r . .74. The measurements of the percent area of stenosis (cutoff 80%) and of the transstenotic pressure gradient (cutoff 0.30) obtained at rest correctly predicted the occurrence of thallium perfusion defects induced by exercise in 83% of the patients

  8. Computed tomographic pulmonary angiography in the assessment of severity of chronic thromboembolic pulmonary hypertension and right ventricular dysfunction

    International Nuclear Information System (INIS)

    Liu Min; Ma Zhanhong; Guo Xiaojuan; Zhang Hongxia; Yang Yuanhua; WangChen

    2011-01-01

    Purpose: The aim was to investigate the role of computed tomographic pulmonary angiography (CTPA) in the assessment of severity and right ventricular function in chronic thromboembolic pulmonary hypertension (CTEPH). Materials and methods: Clinical and radiological data of 56 patients with CTEPH January 2006–October 2009 were retrospectively reviewed in the present study. All patients received CTPA with a 64-row CT using the retrospective ECG-Gated mode before digital subtraction pulmonary angiography and right-heart catheterization. CTPA findings including Right Ventricular diameter (RVd) and left ventricular diameter (LVd) were measured at the end diastole. CT Pulmonary Artery Obstruction Indexes including Qanadli Index and Mastora Index were used in the assessment of severity of pulmonary arterial obstruction. Hemodynamic parameters and pulmonary hypertension classification were evaluated by right-heart catheterization in all patients. Right ventricular function was measured with echocardiography in 49 patients. Results: Qanadli Index and Mastora Index respectively were (37.93 ± 14.74)% and (30.92 ± 16.91)%, which showed a significant difference (Z = −5.983, P = 0.000) and a good correlation (r = 0.881, P = 0.000). Neither Qanadli nor Mastora Index correlated with pulmonary hypertension classification (r = −0.009, P = 0.920) or New York Heart Association heart function classification (r = −0.031, P = 0.756). Neither Qanadli nor Mastora Index correlated with any echocardiographic right ventricular parameters (P > 0.05), while RVd/LVd by CTPA correlated with echocardiographic right ventricular functional parameters (P 2 . CTPA findings correlated with hemodynamic variables. Backward linear regression analysis revealed that the RVd/LVd, Right Ventricular Anterior Wall Thickness (RVAWT), Main Pulmonary Artery trunk diameter (MPAd) were shown to be independently associated with mean Pulmonary Artery Pressure (mPAP) levels (model: r 2 = 0.351, P = 0.025; RVd

  9. Videodensitometric assessment of right and left ventricular functions by digital subtraction angiography

    International Nuclear Information System (INIS)

    Ikeda, Hisao; Yoshiga, Osamu; Shibao, Keigo

    1987-01-01

    Intravenous digital subtraction (DS) ventriculography was performed in a series of 50 patients with heart diseases to determine right and left ventricular volumes and systolic indices. Right ventricular volume and right ventricular ejection fraction obtained by DS ventriculography were well correlated with those by geometric methods. In 43 patients with left ventricular ejection fraction of 55 % or greater, end-diastolic volume, stroke volume, and ejection fraction in the right ventricle did not differ from those in the left ventricle ; however, both the 1/3 ejection fraction and the peak ejection rate of the right ventricle were significantly lower than those of the left ventricle, suggesting the different modes of left and right ventricular contraction. In the other seven patients with chronic left ventricular failure, right ventricular systolic function may be preserved, even when left ventricular function is severely impaired. Digital subtraction ventriculography has proved to be a simple, useful method in the quanlitative and quantitative assessments of the right and left ventricles. (Namekawa, K.)

  10. Coronary Plaque Volume and Composition Assessed by Computed Tomography Angiography in Patients With Late-Onset Major Depression

    DEFF Research Database (Denmark)

    Devantier, T. A.; Norgaard, B. L.; Ovrehus, K. A.

    2014-01-01

    in 28 patients with late-onset major depression and 27 controls. The calcified plaque proportion, i.e., the calcified plaque volume divided by the total plaque volume, was used to assess the plaque composition. Results: There was no statistically significant difference in the total (p = 0.48), calcified......Background: Depression is a stronger predictor for the onset of or death from clinical coronary artery disease than traditional cardiovascular risk factors. The association between depression and coronary artery disease has previously been investigated in non-contrast enhanced computed tomography...... studies with conflicting results. The aim of this study was to further elucidate the depression-coronary artery disease relation by use of coronary computed tomography angiography. Methods: The calcified and noncalcified coronary plaque volumes were determined by semiautomatic volumetric quantification...

  11. State of the art: coronary angiography.

    Science.gov (United States)

    Collet, Carlos; Grundeken, Maik J; Asano, Taku; Onuma, Yoshinobu; Wijns, William; Serruys, Patrick W

    2017-08-25

    In the early days of coronary angiography, the precise quantification of luminal narrowing was challenging. The introduction of balloon angioplasty (percutaneous transluminal coronary angioplasty [PTCA]) by Andreas Grüntzig in 1977 was perhaps the greatest incentive to the development of quantitative coronary angiography (QCA). QCA has played a crucial role in evaluating interventional techniques and assessing the results of new technologies. With the advent of drug-eluting stents (DES), QCA metrics such as late lumen loss and diameter stenosis (restenosis) proved to be instrumental in assessing new technologies. Refinements in QCA with the advent of dedicated bifurcation analysis and three-dimensional (3D) QCA have broadened the application of QCA. Beyond angiographic metrics, new developments in the field of QCA have introduced the functional component in the assessment of coronary lesions. Angiography-derived fractional flow reserve (FFR) may be a good tool for diagnosing ischaemia-producing lesions in patients with non-complex coronary artery disease. Furthermore, the incremental functional information can be used to expand the traditional late lumen loss (LLL) and restenosis concepts.

  12. Assessment of image quality of 64-row Dual Source versus Single Source CT coronary angiography on heart rate : A phantom study

    NARCIS (Netherlands)

    Dikkers, R.; Greuter, M. J. W.; Kristanto, W.; van Ooijen, P. M. A.; Sijens, P. E.; Willems, T. P.; Oudkerk, M.

    Purpose: To assess the influence of temporal resolution on image quality of computed tomographic (CT) coronary angiography by comparing 64-row Dual Source CT (DSCT) and Single Source CT (SSCT) at different heart rates. Methods: An anthropomorphic moving heart phantom was scanned at rest, and at 50

  13. Quantitative Assessment of the IT Agile Transformation

    Directory of Open Access Journals (Sweden)

    Orłowski Cezary

    2017-03-01

    Full Text Available The aim of this paper is to present the quantitative perspective of the agile transformation processes in IT organisations. The phenomenon of agile transformation becomes a complex challenge for an IT organisation since it has not been analysed in detail so far. There is no research on the readiness of IT organisations to realise agile transformation processes. Such processes also prove to have uncontrolled character. Therefore, to minimise the risk of failure referring to the realisation of transformation processes, it is necessary to monitor them. It is also necessary to identify and analyse such processes to ensure their continuous character.

  14. Improved left ventricular function after growth hormone replacement in patients with hypopituitarism: assessment with radionuclide angiography

    International Nuclear Information System (INIS)

    Cuocolo, A.; Nicolai, E.; Colao, A.; Longobardi, S.; Cardei, S.; Fazio, S.; Merola, B.; Lombardi, G.; Sacca, L.; Salvatore, M.

    1996-01-01

    Prolonged growth hormone deficiency (GHD) leads to marked cardiac dysfunction; however, whether reversal of this abnormality may be achieved after specific replacement therapy has not yet been completely clarified. Fourteen patients with childhood-onset GHD (nine men and five women, mean age 27±4 years) and 12 normal control subjects underwent equilibrium radionuclide angiography under control conditions at rest. Patients with GHD were also studied 6 months after recombinant human (rh) GH treatment (0.05 IU/kg per day). Normal control subjects and patients with GHD did not differ with respect to age, gender and heart rate. In contrast, left ventricular ejection fraction (53%±9% vs 66%±6%, P 2 , P 2 , P 2 , P 2 , P <0.01) was observed in GHD patients. In conclusion, prolonged lack of GH leads to impaired left ventricular function at rest. Reversal of this abnormality may be observed after 6 months of specific replacement therapy in patients with childhood-onset GHD. (orig.). With 4 figs., 1 tab

  15. One-stop shop assessment for atrial septal defect closure using 256-slice coronary CT angiography

    Energy Technology Data Exchange (ETDEWEB)

    Yamasaki, Yuzo; Kamitani, Takeshi; Sagiyama, Koji; Yamanouchi, Torahiko; Honda, Hiroshi [Kyushu University, Department of Clinical Radiology, Graduate School of Medical Sciences, 3-1-1 Maidashi, Higashi-ku, Fukuoka (Japan); Nagao, Michinobu; Kawanami, Satoshi [Kyushu University, Department of Molecular Imaging and Diagnosis, Graduate School of Medical Sciences, Fukuoka (Japan); Sakamoto, Ichiro [Kyushu University, Department of Cardiovascular Medicine, Graduate School of Medical Sciences, Fukuoka (Japan); Yamamura, Kenichiro [Kyushu University, Department of Pediatrics, Graduate School of Medical Sciences, Fukuoka (Japan); Yabuuchi, Hidetake [Kyushu University, Department of Health Sciences, Graduate School of Medical Sciences, Fukuoka (Japan)

    2017-02-15

    To investigate the feasibility and accuracy of measurement of the pulmonary to systemic blood flow ratio (Qp/Qs) and defect and rim sizes in secundum atrial septal defects (ASDs) using 256-slice CT, compared to the reference transoesophageal echocardiography (TEE) and right heart catheterization (RHC) measurements. Twenty-three consecutive adult patients with secundum ASDs who underwent retrospective ECG-gated coronary CT angiography (CCTA), TEE and RHC were enrolled in this study. Right ventricular (RV) and left ventricular (LV) stroke volumes (SV) were calculated by biventricular volumetry of CCTA. Qp/Qs-CT was defined as RVSV/LVSV. The sizes of the defect and rim were measured by multi-planar reconstruction CT images. Correlations between Qp/Qs-CT and Qp/Qs-RHC and between the defect diameter obtained by CT and TEE were analyzed by Pearson's coefficient analysis. Rim sizes by CT and TEE were compared by paired t-test. Qp/Qs-CT was significantly correlated with Qp/Qs-RHC (r = 0.83, p < 0.0001), and the defect diameter by CT was significantly correlated with that by TEE (r = 0.95, p < 0.0001). There was no significant difference between CT and TEE in measurements of rim size. 256-slice CCTA allows measuring Qp/Qs and size of defects and rims in patients with secundum ASDs, accomplishing pretreatment evaluation non-invasively and comprehensively. (orig.)

  16. Periodontal disease, tooth loss and coronary heart disease assessed by coronary angiography: a cross-sectional observational study.

    Science.gov (United States)

    Zanella, S M; Pereira, S S; Barbisan, J N; Vieira, L; Saba-Chujfi, E; Haas, A N; Rösing, C K

    2016-04-01

    To evaluate the association between periodontal disease, tooth loss and coronary heart disease (CHD). There is still controversy about the relationship between periodontal disease and tooth loss with vessel obstruction assessed using coronary angiography. This cross-sectional study included 195 patients that underwent coronary angiography and presented with at least six teeth. Patients were classified into three categories of coronary obstruction severity: absence; one or more vessels with ≤ 50% obstruction; and one or more vessels with ≥ 50% obstruction. The extent of coronary obstruction was dichotomized into 0 and ≥ 1 affected vessels. A periodontist blinded to patient CHD status conducted a full mouth examination to determine mean clinical attachment loss, mean periodontal probing depth and tooth loss. Multiple logistic regression models were applied adjusting for age, gender, hypertension, smoking, body mass index, low-density lipoprotein cholesterol and C-reactive protein. Most patients were males (62.1%) older than 60 years (50.8%), and 61% of them had CHD. Mean periodontal probing depth, clinical attachment loss and tooth loss were 2.64 ± 0.72 mm, 4.40 ± 1.31 mm and 12.50 ± 6.98 teeth respectively. In the multivariable models, tooth loss was significantly associated with a higher chance of having at least one obstructed vessel (odds ratio = 1.04; 95% confidence interval 1.01-1.09) and with vessel obstruction ≥ 50% (odds ratio = 1.06; 95% confidence interval 1.01-1.11). No significant associations were found between periodontal variables and vessel obstruction. Tooth loss was found to be a risk indicator for CHD. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  17. A Quantitative Software Risk Assessment Model

    Science.gov (United States)

    Lee, Alice

    2002-01-01

    This slide presentation reviews a risk assessment model as applied to software development. the presentation uses graphs to demonstrate basic concepts of software reliability. It also discusses the application to the risk model to the software development life cycle.

  18. Regional myocardial coronary blood flow reserve in hypertrophic cardiomyopathy assessed by digital subtraction coronary angiography

    Energy Technology Data Exchange (ETDEWEB)

    Terashima, Satoshi; Nakamura, Takashi; Furukawa, Keizo (Kyoto Prefectural Univ. of Medicine (Japan)) (and others)

    1992-01-01

    Using digital subtraction coronary angiography (DSA), we evaluated the regional myocardial coronary blood flow reserve (rMFR) in 18 patients with hypertrophic cardiomyopathy (HCM). There were 13 patients with asymmetrical septal hypertrophy (ASH), and 5 with asymmetrical apical hypertrophy (AAH). Eight subjects without apparent cardiac abnormality served as controls. Relations between the rMFR and regional wall thickness, as determined by echocardiography, were also investigated. Peak contrast density (Cm) and time to Cm (Tm) were measured from digital angiograms at the middle and distal ventricular septum (VS) and at the apical and left ventricular posterior wall (PW). The rMFR of each region of interest was expressed as the ratio of Cm/Tm at the baseline and at peak hyperemic response induced by intracoronary administration of papaverine. The rMFR was significantly lower at the VS and apex in HCM than in controls: middle VS, 1.9[+-]0.5 vs 3.9[+-]0.5, p<0.001; distal VS, 2.0[+-]0.5 vs 4.4[+-]0.9, p<0.001; and the apex, 2.0[+-]0.7 vs 4.5[+-]1.6, p<0.01. However, it did not differ at the PW; 2.6[+-]0.9 vs 3.0[+-]0.9 between the 3 groups. The middle VS and apex, where the wall was the thickest, had the lowest rMFR in ASH and AAH. Furthermore, at the VS and apex, a curvilinear relationship was observed between the rMFR and wall thickness (rMFR=-0.88 ln WT+2.39, r=-0.57, p<0.001). These results indicated that disproportionate hypertrophy contributes to impairment of the rMFR, and that the decreased rMFR may be one of the significant causes of reversible myocardial ischemia in patients with HCM. (author).

  19. Quantitative Ultrasond in the assessment of Osteoporosis

    International Nuclear Information System (INIS)

    Guglielmi, Giuseppe; Terlizzi, Francesca de

    2009-01-01

    Quantitative ultrasound (QUS) is used in the clinical setting to identify changes in bone tissue connected with menopause, osteoporosis and bone fragility. The versatility of the technique, its low cost and lack of ionizing radiation have led to the use of this method worldwide. Furthermore, with increased clinical interest among clinicians, QUS has been applied to several field of investigation of bone, in various pathologies of bone metabolism, in paediatrics, neonatology, genetics and other fields. Several studies have been carried out in recent years to investigate the potential of QUS, with important positive results. The technique is able to predict osteoporotic fractures; some evidence of the ability to monitor therapies has been reported; the usefulness in the management of secondary osteoporosis has been confirmed; studies in paediatrics have reported reference curves for some QUS devices, and there have been relevant studies in conditions involving metabolic bone disorders. This article is an overview of the most relevant developments in the field of QUS, both in the clinical and in the experimental settings. The advantages and limitations of the present technique have been outlined, together with suggestions for the use in the clinical practice.

  20. Quantitative Ultrasond in the assessment of Osteoporosis

    Energy Technology Data Exchange (ETDEWEB)

    Guglielmi, Giuseppe [Department of Radiology, University of Foggia, Viale L. Pinto, 71100 Foggia (Italy); Department of Radiology, Scientific Institute Hospital, San Giovanni Rotondo (Italy)], E-mail: g.guglielmi@unifg.it; Terlizzi, Francesca de [IGEA srl, Via Parmenide 10/A 41012 Carpi, MO (Italy)], E-mail: f.deterlizzi@igeamedical.com

    2009-09-15

    Quantitative ultrasound (QUS) is used in the clinical setting to identify changes in bone tissue connected with menopause, osteoporosis and bone fragility. The versatility of the technique, its low cost and lack of ionizing radiation have led to the use of this method worldwide. Furthermore, with increased clinical interest among clinicians, QUS has been applied to several field of investigation of bone, in various pathologies of bone metabolism, in paediatrics, neonatology, genetics and other fields. Several studies have been carried out in recent years to investigate the potential of QUS, with important positive results. The technique is able to predict osteoporotic fractures; some evidence of the ability to monitor therapies has been reported; the usefulness in the management of secondary osteoporosis has been confirmed; studies in paediatrics have reported reference curves for some QUS devices, and there have been relevant studies in conditions involving metabolic bone disorders. This article is an overview of the most relevant developments in the field of QUS, both in the clinical and in the experimental settings. The advantages and limitations of the present technique have been outlined, together with suggestions for the use in the clinical practice.

  1. Quantitative health impact assessment: current practice and future directions

    NARCIS (Netherlands)

    J.L. Veerman (Lennert); J.J.M. Barendregt (Jan); J.P. Mackenbach (Johan)

    2005-01-01

    textabstractSTUDY OBJECTIVE: To assess what methods are used in quantitative health impact assessment (HIA), and to identify areas for future research and development. DESIGN: HIA reports were assessed for (1) methods used to quantify effects of policy on determinants of health

  2. Quantitative assessment of periodontal bone defects

    International Nuclear Information System (INIS)

    Stelt, P.F. van der; Geraets, W.G.M.

    1987-01-01

    Radiographs are a well-accepted tool in diagnosing periodontal bone lesions and making an accurate evaluation of the treatment. However, the assessment of bone is hampered by the complicated and as it were unpredictable pattern of bone structure. Therefore, and to compensate for the bias always present in human observations, a computer aided procedure was developed to detect and describe periodontal bone lesions. This paper describes a comparison of the performance by human observers and of the computer program. Two series of artificial periodontal bone lesions served as material for the assessments. This study shows that the automated lesion detection program enables an assessment of periodontal bone lesions, which is at least comparable with the results of a group of experienced observers and probably better. It is considerably better than the results of observers individually, and decreases the time-dependent variability appearing in repeated assessments of a single observer. The computer aided detection of periodontal lesions can be considered as a useful and reliable tool in periodontal diagnosis. 9 ref.; 2 figs

  3. Quantitative assessment of structural image quality.

    Science.gov (United States)

    Rosen, Adon F G; Roalf, David R; Ruparel, Kosha; Blake, Jason; Seelaus, Kevin; Villa, Lakshmi P; Ciric, Rastko; Cook, Philip A; Davatzikos, Christos; Elliott, Mark A; Garcia de La Garza, Angel; Gennatas, Efstathios D; Quarmley, Megan; Schmitt, J Eric; Shinohara, Russell T; Tisdall, M Dylan; Craddock, R Cameron; Gur, Raquel E; Gur, Ruben C; Satterthwaite, Theodore D

    2017-12-24

    Data quality is increasingly recognized as one of the most important confounding factors in brain imaging research. It is particularly important for studies of brain development, where age is systematically related to in-scanner motion and data quality. Prior work has demonstrated that in-scanner head motion biases estimates of structural neuroimaging measures. However, objective measures of data quality are not available for most structural brain images. Here we sought to identify quantitative measures of data quality for T1-weighted volumes, describe how these measures relate to cortical thickness, and delineate how this in turn may bias inference regarding associations with age in youth. Three highly-trained raters provided manual ratings of 1840 raw T1-weighted volumes. These images included a training set of 1065 images from Philadelphia Neurodevelopmental Cohort (PNC), a test set of 533 images from the PNC, as well as an external test set of 242 adults acquired on a different scanner. Manual ratings were compared to automated quality measures provided by the Preprocessed Connectomes Project's Quality Assurance Protocol (QAP), as well as FreeSurfer's Euler number, which summarizes the topological complexity of the reconstructed cortical surface. Results revealed that the Euler number was consistently correlated with manual ratings across samples. Furthermore, the Euler number could be used to identify images scored "unusable" by human raters with a high degree of accuracy (AUC: 0.98-0.99), and out-performed proxy measures from functional timeseries acquired in the same scanning session. The Euler number also was significantly related to cortical thickness in a regionally heterogeneous pattern that was consistent across datasets and replicated prior results. Finally, data quality both inflated and obscured associations with age during adolescence. Taken together, these results indicate that reliable measures of data quality can be automatically derived from T1

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

    International Nuclear Information System (INIS)

    Chu, W.C.W.; Lam, W.W.M.; Mok, G.C.F.; Yam, M.; Sung, R.Y.T.

    2006-01-01

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

  5. Nonlinear registration of serial coronary CT angiography (CCTA) for assessment of changes in atherosclerotic plaque

    International Nuclear Information System (INIS)

    Woo, Jonghye; Dey, Damini; Cheng, Victor Y.; Hong, Byung-Woo; Ramesh, Amit; Sundaramoorthi, Ganesh; Nakazato, Ryo; Berman, Daniel S.; Germano, Guido; Kuo, C.-C. Jay; Slomka, Piotr J.

    2010-01-01

    Purpose: Coronary CT angiography (CCTA) is a high-resolution three-dimensional imaging technique for the evaluation of coronary arteries in suspected or confirmed coronary artery disease (CAD). Coregistration of serial CCTA scans would allow precise superimposition of images obtained at two different points in time, which could aid in recognition of subtle changes and precise monitoring of coronary plaque progression or regression. To this end, the authors aimed at developing a fully automatic nonlinear volume coregistration for longitudinal CCTA scan pairs. Methods: The algorithm combines global displacement and local deformation using nonlinear volume coregistration with a volume-preserving constraint. Histogram matching of intensities between two serial scans is performed prior to nonlinear coregistration with dense nonparametric local deformation in which sum of squared differences is used as a similarity measure. The approximate segmentation of coronary arteries obtained from commercially available software provides initial anatomical landmarks for the coregistration algorithm that help localize and emphasize the structure of interest. To avoid possible bias caused by incorrect segmentation, the authors convolve the Gaussian kernel with the segmented binary coronary tree mask and define an extended weighted region of interest. A multiresolution approach is employed to represent coarse-to-fine details of both volumes and the energy function is optimized using a gradient descent method. The authors applied the algorithm in ten paired CCTA datasets (20 scans in total) obtained within 10.7±5.7 months from each other on a dual source CT scanner to monitor progression of CAD. Results: Serial CCTA coregistration was successful in 9/10 cases as visually confirmed. The global displacement and local deformation of target registration error obtained from four anatomical landmarks were 2.22±1.15 and 1.56±0.74 mm, respectively, and the inverse consistency error of local

  6. Quantitative perfusion computed tomography measurements of cerebral hemodynamics: Correlation with digital subtraction angiography identified primary and secondary cerebral collaterals in internal carotid artery occlusive disease

    International Nuclear Information System (INIS)

    Cheng Xiaoqing; Tian Jianming; Zuo Changjing; Liu Jia; Zhang Qi; Lu Guangming

    2012-01-01

    Background: The aim of the present study was to assess hemodynamic variations in symptomatic unilateral internal carotid artery occlusion (ICAO) patients with primary collateral flow via circle of Willis or secondary collateral flow via ophthalmic artery and/or leptomeningeal collaterals. Methods: Thirty-eight patients with a symptomatic unilateral ICAO were enrolled in the study. Based on digital subtraction angiography (DSA) findings, patients were classified into 2 groups: primary collateral (n = 14) and secondary collateral (n = 24) groups. Collateral flow hemodynamics were investigated with perfusion computed tomography (PCT) by measuring the cerebral blood flow (CBF), cerebral blood volume (CBV) and time to peak (TTP) in the hemispheres ipsilateral and contralateral to ICAO. Based on the measurements, the ipsilateral to contralateral ratio for each parameter was calculated and compared. Results: Irrespective of the collateral patterns, ipsilateral CBF was not significantly different from that of the contralateral hemisphere (P = 0.285); ipsilateral CBV and TTP was significantly increased compared with those of the contralateral hemisphere (P = 0.000 and P = 0.000 for CBV and TTP, respectively). Furthermore, patients with secondary collaterals had significantly larger ipsilateral-to-contralateral ratios for both CBV (rCBV, P = 0.0197) and TTP (rTTP, P = 0.000) than those of patients with only primary collaterals. These two groups showed no difference in ipsilateral-to-contralateral ratio for CBF (rCBF, P = 0.312). Conclusion: Patients with symptomatic unilateral ICAO in our study were in an autoregulatory vasodilatation status. Moreover, secondary collaterals in ICAO patients were correlated with ipsilateral CBV and delayed TTP that suggested severe hemodynamic impairment, presumably increasing the risk of ischemic events.

  7. Quantitative assessment of limb blood flow using Tc-99m labeled red blood cells

    International Nuclear Information System (INIS)

    Itoh, Kazuo; Shougase, Takashi; Kawamura, Naoyuki; Tsukamoto, Eriko; Nakada, Kunihiro; Sakuma, Makoto; Furudate, Masayori

    1987-01-01

    A quantitative assessment of limb blood flow using a non-diffusible radioindicator, Tc-99m labeled red blood cells, was reported. This was an application of venous occlusion plethysmography using radionuclide which was originally proposed by M. Fukuoka et al. The peripheral blood flow (mean ± s.e.) of 30 legs in a normal control group was 1.87 ± 0.08 ml/100 ml/min. In heart diseases (46 legs), it was 1.49 ± 0.13 ml/100 ml/min. The limb blood flow between a control group and heart diseases was statistically significant (p < 0.01) in the t-test. The peripheral blood flow at rest between diseased legs and normal legs in occlusive arterial disorders was also statistically significant (p < 0.01) in a paired t-test. RAVOP was done after the completion of objective studies such as radionuclide angiography or ventriculography. Technique and calculation of a blood flow were very easy and simple. RAVOP study which was originally proposed by Fukuoka et al. was reappraised to be hopeful for quantitative measurement of limb blood flow as a non-invasive technique using Tc-99m labeled red blood cells. (author)

  8. Pediatric angiography

    International Nuclear Information System (INIS)

    Fitz, A.R.

    1987-01-01

    Angiography of the cerebral and visceral arterial systems is performed much less frequently than it was before the advent of computed tomographic scanning (CT). Most institutions have experienced at least a 50% reduction in the number of angiograms performed since installing a CT scanner. However, angiography still plays an important role in the confirmation of diagnoses made using a scanner, and in providing valuable information to the surgeon prior to excision of tumors or the repair of traumatized organs. Recently a number of sophisticated therapeutic procedures requiring vascular catheterization and the injection of contrast agents have been developed. In these procedures catheters are selectively placed in blood vessels perfusing a pathological process, such as an arteriovenous malformation, or at the site of an arterial stenosis; embolization of the arteriovenous malformation or tumor, or dilatation of the stenotic segment, is then performed. Whether the vessel catheterization is for diagnostic or therapeutic purposes, the basic approach is the same, and the technologist's duties are similar. The principal difference between a diagnostic and a therapeutic procedure is the length of time required to carry out the study; therapeutic procedures often require significantly longer periods of general anesthesia or sedation than do diagnostic studies

  9. Value of Myocardial Perfusion Assessment With Coronary Computed Tomography Angiography in Patients With Recent Acute-Onset Chest Pain

    DEFF Research Database (Denmark)

    Sørgaard, Mathias H; Linde, Jesper J; Kühl, J Tobias

    2018-01-01

    OBJECTIVES: The authors sought to perform a randomized controlled trial to evaluate the clinical efficacy of combined examination with coronary computed tomography angiography (CTA) and computed tomography perfusion imaging (CTP) compared to coronary CTA alone. BACKGROUND: Stress myocardial CTP may...

  10. Comparison of volume and diameter measurement in assessing small abdominal aortic aneurysm expansion examined using computed tomographic angiography

    International Nuclear Information System (INIS)

    Parr, Adam; Jayaratne, Chanaka; Buttner, Petra; Golledge, Jonathan

    2011-01-01

    Aim: First we aimed to assess the reproducibility of a computer tomography angiography (CTA) based technique for measuring infra-renal aortic volume and diameter. Second we sought to investigate whether changes in aortic volume and diameter were similar during follow-up. Materials and methods: A prospective series of 57 patients, with aortic diameter initially measuring between 25 and 55 mm, were assessed with 2 CTAs a median of 14 months apart. Aortic volume and maximum diameter (both axial and orthogonal) were measured by a semi-automated workstation protocol based on previously defined techniques. Intra- and inter-observer reproducibility were assessed by repeat assessment of the initial CTA images of the first 33 patients included in the study, in order to estimate the 95% limits of agreements. Changes in aortic dimensions between the first and follow-up CTA, were defined for volume and diameter separately as changes greater than their respective 95% limits of agreement. Results: Reproducibility of aortic volume and diameter was excellent with an average coefficient of variation 3 (0.01-14.18), 1.2 mm (0.40-3.50) and 1.4 mm (-0.15 to 3.55) respectively. Forty-two percent of patients who had increased aortic volume above the 95% limit of agreement did not display corresponding axial or orthogonal diameter changes. Conclusions: Infra-renal total aortic volume, axial and orthogonal diameter can all be measured reproducibly from CTA. Aortic volume changes are not always reflected by similar changes in diameter and therefore provide complementary information when assessing AAA expansion over time.

  11. [Quantitative echographic assessment of muscular physiopathology].

    Science.gov (United States)

    Talia, B; Casini, A; Fabbri, F; Lotti, F; Masotti, L

    1993-05-01

    The evaluation of muscular contraction is one of the main variables in muscular reeducation treatment protocols. US depicts muscular structure and size, as well as changes in both. A real-time US unit with 5/7.5 MHz probes and a computer with advanced software were used; the US unit was modified so as to reduce scanning times and to yield a high number of images/second (about 45). During endoscopy, a higher number of intermediate positions can thus be found between rest and contraction, which yields more statistically significant results. The US unit is connected to a video-recorder and to an electrostimulator to obtain isometric and isotonic contractions; the latter unit is connected to the US unit so that the electric and the US energies can be emitted simultaneously and the synchronism of the contraction and of the beginning of the electric stimulation can be assessed. Besides normal control subjects, patients with hypotrophic recto-femoral muscle were examined: the results were collected in a databank useful to choose the most appropriate treatment, to follow patients during therapy, to evaluate the final results and finally to be used in sports activities.

  12. Time of flight MR angiography assessment casts doubt on the association between transient global amnesia and intracranial jugular venous reflux

    International Nuclear Information System (INIS)

    Kang, Yeonah; Kim, Eunhee; Kim, Jae Hyoung; Choi, Byung Se; Jung, Cheolkyu; Bae, Yun Jung; Lee, Kyung Mi; Lee, Dong Hoon

    2015-01-01

    Evidence of intracranial venous reflux flow due to jugular venous reflux (JVR) on time of flight (TOF) MR angiography (MRA) is thought to be highly associated with transient global amnesia (TGA) - evidence that supports the venous congestion theory of TGA pathophysiology. However, recent studies indicate that intracranial JVR on TOF MRA is occasionally observed in normal elderly. Therefore, the purpose of this study was to compare the prevalence of intracranial JVR on TOF MRA in patients with TGA and two control groups. Three age- and sex-matched groups of subjects that received MRI and MRA were enrolled. The groups comprised 167 patients with TGA, 167 visitors to the emergency room (ER) and 167 visitors to a health promotion centre (HPC). Intracranial JVR was defined as abnormal venous signals in the inferior petrosal, sigmoid and/or transverse sinuses on TOF MRA. The prevalence of intracranial JVR was assessed across the three groups. Intracranial JVR was seen in seven (4.2 %) TGA patients, eight (4.8 %) ER visitors and three (1.8 %) HPC visitors, respectively. No statistically significant differences were observed among the three groups. TGA patients showed a low prevalence of intracranial JVR on TOF MRA, and no statistical differences were found in comparison with control groups. (orig.)

  13. Time of flight MR angiography assessment casts doubt on the association between transient global amnesia and intracranial jugular venous reflux

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Yeonah; Kim, Eunhee; Kim, Jae Hyoung; Choi, Byung Se; Jung, Cheolkyu; Bae, Yun Jung; Lee, Kyung Mi [Seoul National University College of Medicine, Seoul National University Bundang Hospital, Department of Radiology, Seongnam-si, Gyeonggi-do (Korea, Republic of); Lee, Dong Hoon [Seoul Medical Center, Department of Radiology, Seoul (Korea, Republic of)

    2014-10-03

    Evidence of intracranial venous reflux flow due to jugular venous reflux (JVR) on time of flight (TOF) MR angiography (MRA) is thought to be highly associated with transient global amnesia (TGA) - evidence that supports the venous congestion theory of TGA pathophysiology. However, recent studies indicate that intracranial JVR on TOF MRA is occasionally observed in normal elderly. Therefore, the purpose of this study was to compare the prevalence of intracranial JVR on TOF MRA in patients with TGA and two control groups. Three age- and sex-matched groups of subjects that received MRI and MRA were enrolled. The groups comprised 167 patients with TGA, 167 visitors to the emergency room (ER) and 167 visitors to a health promotion centre (HPC). Intracranial JVR was defined as abnormal venous signals in the inferior petrosal, sigmoid and/or transverse sinuses on TOF MRA. The prevalence of intracranial JVR was assessed across the three groups. Intracranial JVR was seen in seven (4.2 %) TGA patients, eight (4.8 %) ER visitors and three (1.8 %) HPC visitors, respectively. No statistically significant differences were observed among the three groups. TGA patients showed a low prevalence of intracranial JVR on TOF MRA, and no statistical differences were found in comparison with control groups. (orig.)

  14. Magnetic resonance angiography virtual endoscopy in the assessment of pulmonary veins before radiofrequency ablation procedures for atrial fibrillation

    International Nuclear Information System (INIS)

    Cirillo, S.; Tosetti, Irene; Giuseppe, M.De; Longo, M.; Regge, D.; Bonamini, R.; Gaita, F.; Bianchi, F.; Vivalda, L.

    2004-01-01

    Magnetic resonance angiography (MRA) is a safe and non-invasive imaging method that can readily depict the pulmonary veins (PV), whose imaging has acquired momentum with the advent of new techniques for radiofrequency ablation of atrial fibrillation (AF). We evaluated whether virtual endoscopy from 3D MRA images (MRA-VE) is feasible in studying the morphology of PV. Fifty patients with AF underwent pre-ablative MRA (1.5 T). Images were acquired with axial T-2 weighted and 3D-SPGR sequences after intravenous administration of Gd-DTPA and automatic triggering. Postprocessing was performed by an experienced radiologist with maximum intensity projection (MIP) and virtual endoscopy software (Navigator, GEMS). The venoatrial junction was visualized with MRA-VE in 49 of 50 patients (98.0%). Twenty-seven patients (55.1%) had two ostia on both sides, 13 patients (26.5%) had two ostia on the right and a single common ostium on the left, 5 patients (10.2%) had accessory PV and 4 patients (8.2%) had both an accessory right PV and a single common ostium on the left. Flythrough navigation showed the number and spatial disposition of second-order PV branches in 48 out of 49 patients (98.0%). MRA-VE is an excellent tool for at-a-glance visualization of ostia morphology, navigation of second-generation PV branches and easy endoluminal assessment of left atrial structures in pre-ablative imaging. (orig.)

  15. Assessment of renal artery stenosis: Comparison of captopril renography and gadolinium-enhanced breath-hold MR angiography

    Energy Technology Data Exchange (ETDEWEB)

    Bongers, V.; Bakker, J.; Beutler, J.J.; Beek, F.J.A.; De Klerk, J.M.H

    2000-05-01

    AIM: To determine the accuracy of captopril renography (CR) and gadolinium-enhanced breath-hold magnetic resonance (MR) angiography in the diagnosis of 50-99% renal artery stenosis (RAS). MATERIALS AND METHODS: Forty-three patients with possible RAS, of whom 53% had renal function impairment (creatinine >130 {mu}mol/l), were included.{sup 99m}Tc-mercaptoacetyl triglycine (MAG{sub 3}) renography was performed after an oral dose of 25 mg captopril. Gadolinium-enhanced MR angiography was performed on a standard 1.5 Tesla system: TR 13.5, TE 3.5, flip angle 60 deg. , matrix 195 x 512. Intra-arterial digital subtraction angiography (DSA) was the standard of reference. RESULTS: Captropril renography accurately categorized 22 of 26 patients who had either uni- or bilateral RAS of 50-99%. The sensitivity and specificity of CR for the detection of 50-99% stenosis were 85 and 71%, respectively. With MR angiography one occluded artery was incorrectly diagnosed as a stenosis. Sensitivity and specificity were 100 and 94%, respectively. The difference between the accuracies of MR angiography and CR was statistically significant (P = 0.02). The accuracy of CR was lower in patients with renal impairment (70%) than in those with normal renal function (90%). CONCLUSION: MR angiography showed a high accuracy in diagnosing RAS of between 50 and 99%. CR was less accurate than MR angiography, especially in patients with renal function impairment. In patients with normal renal function, however, CR remains a useful diagnostic test. Bongers, V. (2000)

  16. Accuracy of multislice CT angiography for the assessment of in-stent restenoses in the iliac arteries at reduced dose: a phantom study.

    Science.gov (United States)

    Perisinakis, K; Manousaki, E; Zourari, K; Tsetis, D; Tzedakis, A; Papadakis, A; Karantanas, A; Damilakis, J

    2011-03-01

    We investigated the potential of low-dose CT angiography for accurate assessment of in-stent restenoses (ISRs) of the iliac artery. A Rando anthropomorphic phantom (Alderson Research Labs, Stanford, CA), custom-made wax simulating hyperplastic tissue and a nitinol stent were used to simulate a patient with clinically relevant iliac artery ISRs. The cylindrical lumen was filled with a solution of iodine contrast medium diluted in saline, representing a patient's blood during CT angiography. The phantom was subjected to standard- and low-dose angiographic exposures using a modern multidetector (MD) CT scanner. The percentage of ISR was determined using the profile along a line normal to the lumen axis on reconstructed images of 2 and 5 mm slice thickness. Percentage ISRs derived using the standard- and low-dose protocols were compared. In a preliminary study, seven patients with stents were subjected to standard- and low-dose MDCT angiography during follow-up. The resulting images were assessed and compared by two experienced radiologists. The accuracy in measuring the percentage ISR was found to be better than 12% for all simulated stenoses. The differences between percentage ISRs measured on images obtained at 120 kVp/160 mAs and 80 kVp/80 mAs were below 6%. Patient image sets acquired using low-exposure factors were judged to be of satisfactory diagnostic quality. The assessment of ISR did not differ significantly between image sets acquired using the standard factors and those acquired using the low-exposure factors, although the mean reduction in patient effective dose was 48%. A reduction in exposure factors during MDCT angiography of the iliac artery is possible without affecting the accuracy in the determination of ISRs.

  17. Indocyanine green fluorescence angiography for intraoperative assessment of gastrointestinal anastomotic perfusion

    DEFF Research Database (Denmark)

    Degett, Thea Helene; Andersen, Helene Schou; Gögenur, Ismail

    2016-01-01

    was to systematically review the literature concerning ICG-FA to assess perfusion during the construction of a primary gastrointestinal anastomosis in order to predict anastomotic leakage. METHODS: The following four databases PubMed, Scopus, Embase, and Cochrane were independently searched by two authors. Studies were...

  18. BBN based Quantitative Assessment of Software Design Specification

    International Nuclear Information System (INIS)

    Eom, Heung-Seop; Park, Gee-Yong; Kang, Hyun-Gook; Kwon, Kee-Choon; Chang, Seung-Cheol

    2007-01-01

    Probabilistic Safety Assessment (PSA), which is one of the important methods in assessing the overall safety of a nuclear power plant (NPP), requires quantitative reliability information of safety-critical software, but the conventional reliability assessment methods can not provide enough information for PSA of a NPP. Therefore current PSA which includes safety-critical software does not usually consider the reliability of the software or uses arbitrary values for it. In order to solve this situation this paper proposes a method that can produce quantitative reliability information of safety-critical software for PSA by making use of Bayesian Belief Networks (BBN). BBN has generally been used to model an uncertain system in many research fields including the safety assessment of software. The proposed method was constructed by utilizing BBN which can combine the qualitative and the quantitative evidence relevant to the reliability of safety critical software. The constructed BBN model can infer a conclusion in a formal and a quantitative way. A case study was carried out with the proposed method to assess the quality of software design specification (SDS) of safety-critical software that will be embedded in a reactor protection system. The intermediate V and V results of the software design specification were used as inputs to the BBN model

  19. Coronary CT angiography in coronary artery disease: Opportunities and challenges

    Directory of Open Access Journals (Sweden)

    Zhonghua Sun

    2016-06-01

    Full Text Available Coronary CT angiography is widely recognised as a reliable imaging modality for the diagnosis of coronary artery disease. Coronary CT angiography not only provides excellent visualisation of anatomical changes in the coronary artery with high diagnostic value in the detection of lumen stenosis or occlusion, but also offers quantitative characterisation of coronary plaque components. Furthermore, coronary CT angiography allows myocardial perfusion imaging with diagnostic value comparable to the reference standard method. Coronary CT angiography-derived haemodynamic analysis has the potential to evaluate functional significance of coronary lesions. This review article aims to provide an overview of clinical applications of coronary CT angiography in coronary artery disease.

  20. Qualitative and Quantitative Hippocampal MRI Assessments in Intractable Epilepsy

    Directory of Open Access Journals (Sweden)

    Paramdeep Singh

    2013-01-01

    Full Text Available Aims. To acquire normative data of hippocampal volumes and T2 relaxation times, to evaluate and compare qualitative and quantitative assessments in evaluating hippocampi in patients with different durations of intractable epilepsy, and to propose an imaging protocol based on performance of these techniques. Methods. MRI analysis was done in 50 nonepileptic controls and 30 patients with intractable epilepsy on 1.5T scanner. Visual assessment and hippocampal volumetry were done on oblique coronal IR/T2W and T1W MP-RAGE images, respectively. T2 relaxation times were measured using 16-echo Carr-Purcell-Meiboom-Gill sequence. Volumetric data was normalized for variation in head size between individuals. Patients were divided into temporal ( and extratemporal ( groups based on clinical and EEG localization. Results. In controls, right hippocampal volume was slightly more than the left with no effect of age or gender. In TLE patients, hippocampal volumetry provided maximum concordance with EEG. Visual assessment of unilateral pathology concurred well with measured quantitative values but poorly in cases with bilateral pathologies. There were no significant differences of mean values between extratemporal group and controls group. Quantitative techniques detected mild abnormalities, undetected on visual assessment. Conclusions. Quantitative techniques are more sensitive to diagnose bilateral and mild unilateral hippocampal abnormalities.

  1. Method for quantitative assessment of nuclear safety computer codes

    International Nuclear Information System (INIS)

    Dearien, J.A.; Davis, C.B.; Matthews, L.J.

    1979-01-01

    A procedure has been developed for the quantitative assessment of nuclear safety computer codes and tested by comparison of RELAP4/MOD6 predictions with results from two Semiscale tests. This paper describes the developed procedure, the application of the procedure to the Semiscale tests, and the results obtained from the comparison

  2. Modeling Logistic Performance in Quantitative Microbial Risk Assessment

    NARCIS (Netherlands)

    Rijgersberg, H.; Tromp, S.O.; Jacxsens, L.; Uyttendaele, M.

    2010-01-01

    In quantitative microbial risk assessment (QMRA), food safety in the food chain is modeled and simulated. In general, prevalences, concentrations, and numbers of microorganisms in media are investigated in the different steps from farm to fork. The underlying rates and conditions (such as storage

  3. Does routine pressure wire assessment influence management strategy at coronary angiography for diagnosis of chest pain?: the RIPCORD study.

    Science.gov (United States)

    Curzen, Nick; Rana, Omar; Nicholas, Zoe; Golledge, Peter; Zaman, Azfar; Oldroyd, Keith; Hanratty, Colm; Banning, Adrian; Wheatcroft, Stephen; Hobson, Alex; Chitkara, Kam; Hildick-Smith, David; McKenzie, Dan; Calver, Alison; Dimitrov, Borislav D; Corbett, Simon

    2014-04-01

    The use of coronary angiography (CA) for diagnosis and management of chest pain (CP) has several flaws. The assessment of coronary artery disease using fractional flow reserve (FFR) is a well-validated technique for describing lesion-level ischemia and improves clinical outcome in the context of percutaneous coronary intervention. The impact of routine FFR at the time of diagnostic CA on patient management has not been determined. Two hundred patients with stable CP underwent CA for clinical indications. The supervising cardiologist (S.C.) made a management plan based on CA (optimal medical therapy alone, percutaneous coronary intervention, coronary artery bypass grafting, or more information required) and also recorded which stenoses were significant. An interventional cardiologist then measured FFR in all patent coronary arteries of stentable diameter (≥2.25 mm). S.C. was then asked to make a second management plan when FFR results were disclosed. Overall, after disclosure of FFR data, management plan based on CA alone was changed in 26% of patients, and the number and localization of functional stenoses changed in 32%. Specifically, of 72 cases in which optimal medical therapy was recommended after CA, 9 (13%) were actually referred for revascularization with FFR data. By contrast, of 89 cases in whom management plan was optimal medical therapy based on FFR, revascularization would have been recommended in 25 (28%) based on CA. Routine measurement of FFR at CA has important influence both on which coronary arteries have significant stenoses and on patient management. These findings could have important implications for clinical practice. http://www.clinicaltrial.gov. Unique identifier: NCT01070771.

  4. Assessing a narrated white board animation as part of the consent process for intravenous fluorescein angiography: a randomized educational study.

    Science.gov (United States)

    Mednick, Zale; Irrcher, Isabella; Hopman, Wilma M; Sharma, Sanjay

    2016-12-01

    To determine if a narrated white board animation (nWBA) video as part of the consent process for intravenous fluorescein angiography (IVFA) improves patient comprehension compared with a standard consent process. Prospective, randomized study. Patients undergoing an initial IVFA investigation. Three groups of 26 patients (N = 78) naïve to the IVFA procedure were included. Groups 1 and 2 consisted of patients undergoing IVFA for diagnostic purposes. Group 1 received the IVFA information via standard physician-patient interaction to obtain standard consent. Group 2 received IVFA information by watching an nWBA explaining the purpose, method, and risks of the diagnostic test to obtain informed consent. Group 3 comprised patients who were not scheduled to undergo IVFA. This group was exposed to both the standard and nWBA consent. All groups completed a 6-question knowledge quiz to assess retained information and a survey to reflect on the consent experience. Participants receiving information via standard physician-patient interaction to obtain informed consent had a lower mean knowledge score (4.38 out of 6; 73%) than participants receiving the information to obtain consent via nWBA (5.04 out of 6, 84%; P = 0.023). Of participants receiving both forms of information (group 3) to obtain informed consent, 73% preferred the nWBA to the standard consent process. Participants receiving consent information for an IVFA diagnostic test via nWBA have better knowledge retention regarding the IVFA procedure and preferred this medium compared with participants receiving the standard physician-patient interaction for obtaining consent. Incorporation of multimedia into the informed consent process should be explored for other diagnostic tests. Copyright © 2016 Canadian Ophthalmological Society. Published by Elsevier Inc. All rights reserved.

  5. Automatic assessment of coronary artery calcium score from contrast-enhanced 256-row coronary computed tomography angiography.

    Science.gov (United States)

    Rubinshtein, Ronen; Halon, David A; Gaspar, Tamar; Lewis, Basil S; Peled, Nathan

    2014-01-01

    The coronary artery calcium score (CS), an independent predictor of cardiovascular events, can be obtained from a stand-alone nonenhanced computed tomography (CT) scan (CSCT) or as an additional nonenhanced procedure before contrast-enhanced coronary CT angiography (CCTA). We evaluated the accuracy of a novel fully automatic tool for computing CS from the CCTA examination. One hundred thirty-six consecutive symptomatic patients (aged 59 ± 11 years, 40% female) without known coronary artery disease who underwent both 256-row CSCT and CCTA were studied. Original scan reconstruction (slice thickness) was maintained (3 mm for CSCT and 0.67 mm for CCTA). CS was computed from CCTA by an automatic tool (COR Analyzer, rcadia Medical Imaging, Haifa, Israel) and compared with CS results obtained by standard assessment of nonenhanced CSCT (HeartBeat CS, Philips, Cleveland, Ohio). We also compared both methods for classification into 5 commonly used CS categories (0, 1 to 10, 11 to 100, 101 to 400, >400 Agatston units). All scans were of diagnostic quality. CS obtained by the COR Analyzer from CCTA classified 111 of 136 (82%) of patients into identical categories as CS by CSCT and 24 of remaining 25 into an adjacent category. Overall, CS values from CCTA showed high correlation with CS values from CSCT (Spearman rank correlation = 0.95, p automatically computed from 256-row CCTA correlated highly with standard CS values obtained from nonenhanced CSCT. CS obtained directly from CCTA may obviate the need for an additional scan and attendant radiation. Copyright © 2014 Elsevier Inc. All rights reserved.

  6. Assessment of coronary artery disease risk in 5463 patients undergoing cardiac surgery: when is preoperative coronary angiography necessary?

    Science.gov (United States)

    Thalji, Nassir M; Suri, Rakesh M; Daly, Richard C; Dearani, Joseph A; Burkhart, Harold M; Park, Soon J; Greason, Kevin L; Joyce, Lyle D; Stulak, John M; Huebner, Marianne; Li, Zhuo; Frye, Robert L; Schaff, Hartzell V

    2013-11-01

    We sought to critically analyze the routine use of conventional coronary angiography (CCA) before noncoronary cardiac surgery and to assess clinical prediction models that might allow more selective use of CCA in this setting. We studied 5463 patients undergoing aortic valve surgery, mitral valve surgery, or septal myectomy with or without coronary artery bypass grafting from 2001 to 2010. Preoperative CCAs were evaluated for the presence of significant coronary artery disease (CAD). Random forests and logistic regression methods were used to determine the predictors of significant (≥50%) coronary stenosis. Preoperative CCA was performed in 4711 patients (86%). Two thirds of those with angina, previous myocardial infarction, or percutaneous coronary intervention had significant CAD found on CCA, versus one third of patients free of these risk factors (P < .001). Among 3019 patients without angina, previous myocardial infarction or percutaneous coronary intervention, older age, male gender, diabetes, and peripheral vascular disease independently predicted significant CAD (P < .001 for all; C-index = 0.74). Specifically, a multivariate model with these variables identified 10% (301 of 3019) of patients as having a low (≤10%) probability of coronary stenosis, of whom fewer than 5% had significant CAD and fewer than 1% had left main or triple-vessel coronary disease. In the absence of angina, previous myocardial infarction, or percutaneous coronary intervention, preoperative CCA identified significant CAD in only one third of patients. Our clinical prediction models could enhance the identification of patients at low risk of significant CAD for whom CCA might potentially be avoided before cardiac surgery. This strategy may improve the efficiency of cardiac surgical care delivery by diminishing procedure-related morbidity and offering significant cost savings. Copyright © 2013 The American Association for Thoracic Surgery. Published by Mosby, Inc. All rights

  7. Assessment of myocardial enhancement during coronary CT angiography in critically ill patients

    International Nuclear Information System (INIS)

    Mírka, Hynek; Ferda, Jiří; Baxa, Jan

    2016-01-01

    Highlights: • There are still unmet needs for the imaging, such as conditions with unknown cause that are not associated with dominant symptoms indicating primarily cardiac cause. • The contribution of the myocardial enhancement evaluation improves to determining the diagnosis of acute myocardial injury and choosing appropriate treatment. • When incorporating the myocardial enhancement assessment into the imaging algorithm, emphasis is placed on a uniform evaluation approach. • The color coded images of the myocardial enhancement in emergency situations help identify the most serious pathologies and shorten the time to adequate therapy. - Abstract: There are still challenges and unmet needs for the imaging techniques, such as conditions of uncertain origin in patients with clinically serious, life-threatening conditions with unknown cause that are not associated with dominant chest pain, ECG changes or other symptoms indicating a possible primarily cardiac or coronary cause. The contribution of the myocardial enhancement evaluation of urgent cardiac CTA scans significantly improves to determining the diagnosis of acute myocardial injury and choosing appropriate treatment. When incorporating the myocardial enhancement assessment into the imaging algorithm of an emergency department, emphasis is placed on a uniform imaging procedure and a uniform evaluation approach. The color coded images of the myocardial enhancement in emergency situations helps identify the most serious pathologies and shorten the time to adequate targeted therapy in patients.

  8. Assessment of myocardial enhancement during coronary CT angiography in critically ill patients

    Energy Technology Data Exchange (ETDEWEB)

    Mírka, Hynek, E-mail: mirka@fnplzen.cz [Department of Imaging Methods, Faculty of Medicine and University Teaching Hospital in Pilsen, Alej Svobody 80, 304 60 Plzeň (Czech Republic); Biomedical Centre, Faculty of Medicine in Plzen, Charles University in Prague, Alej Svobody 76, 304 60 Plzeň (Czech Republic); Ferda, Jiří, E-mail: ferda@fnplzen.cz [Department of Imaging Methods, Faculty of Medicine and University Teaching Hospital in Pilsen, Alej Svobody 80, 304 60 Plzeň (Czech Republic); Baxa, Jan, E-mail: baxaj@fnplzen.cz [Department of Imaging Methods, Faculty of Medicine and University Teaching Hospital in Pilsen, Alej Svobody 80, 304 60 Plzeň (Czech Republic)

    2016-10-15

    Highlights: • There are still unmet needs for the imaging, such as conditions with unknown cause that are not associated with dominant symptoms indicating primarily cardiac cause. • The contribution of the myocardial enhancement evaluation improves to determining the diagnosis of acute myocardial injury and choosing appropriate treatment. • When incorporating the myocardial enhancement assessment into the imaging algorithm, emphasis is placed on a uniform evaluation approach. • The color coded images of the myocardial enhancement in emergency situations help identify the most serious pathologies and shorten the time to adequate therapy. - Abstract: There are still challenges and unmet needs for the imaging techniques, such as conditions of uncertain origin in patients with clinically serious, life-threatening conditions with unknown cause that are not associated with dominant chest pain, ECG changes or other symptoms indicating a possible primarily cardiac or coronary cause. The contribution of the myocardial enhancement evaluation of urgent cardiac CTA scans significantly improves to determining the diagnosis of acute myocardial injury and choosing appropriate treatment. When incorporating the myocardial enhancement assessment into the imaging algorithm of an emergency department, emphasis is placed on a uniform imaging procedure and a uniform evaluation approach. The color coded images of the myocardial enhancement in emergency situations helps identify the most serious pathologies and shorten the time to adequate targeted therapy in patients.

  9. Multiparametric Quantitative Ultrasound Imaging in Assessment of Chronic Kidney Disease.

    Science.gov (United States)

    Gao, Jing; Perlman, Alan; Kalache, Safa; Berman, Nathaniel; Seshan, Surya; Salvatore, Steven; Smith, Lindsey; Wehrli, Natasha; Waldron, Levi; Kodali, Hanish; Chevalier, James

    2017-11-01

    To evaluate the value of multiparametric quantitative ultrasound imaging in assessing chronic kidney disease (CKD) using kidney biopsy pathologic findings as reference standards. We prospectively measured multiparametric quantitative ultrasound markers with grayscale, spectral Doppler, and acoustic radiation force impulse imaging in 25 patients with CKD before kidney biopsy and 10 healthy volunteers. Based on all pathologic (glomerulosclerosis, interstitial fibrosis/tubular atrophy, arteriosclerosis, and edema) scores, the patients with CKD were classified into mild (no grade 3 and quantitative ultrasound parameters included kidney length, cortical thickness, pixel intensity, parenchymal shear wave velocity, intrarenal artery peak systolic velocity (PSV), end-diastolic velocity (EDV), and resistive index. We tested the difference in quantitative ultrasound parameters among mild CKD, moderate to severe CKD, and healthy controls using analysis of variance, analyzed correlations of quantitative ultrasound parameters with pathologic scores and the estimated glomerular filtration rate (GFR) using Pearson correlation coefficients, and examined the diagnostic performance of quantitative ultrasound parameters in determining moderate CKD and an estimated GFR of less than 60 mL/min/1.73 m 2 using receiver operating characteristic curve analysis. There were significant differences in cortical thickness, pixel intensity, PSV, and EDV among the 3 groups (all P quantitative ultrasound parameters, the top areas under the receiver operating characteristic curves for PSV and EDV were 0.88 and 0.97, respectively, for determining pathologic moderate to severe CKD, and 0.76 and 0.86 for estimated GFR of less than 60 mL/min/1.73 m 2 . Moderate to good correlations were found for PSV, EDV, and pixel intensity with pathologic scores and estimated GFR. The PSV, EDV, and pixel intensity are valuable in determining moderate to severe CKD. The value of shear wave velocity in

  10. Digital subtraction angiography in ischemic cerebrovascular accidents

    International Nuclear Information System (INIS)

    Manelfe, C.; Bonafe, A.; Ducos de Lahitte, M.; Rascol, A.; Prere, J.; Guiraud, B.; Marc-Vergnes, J.P.

    1983-01-01

    Recent advances in computer and radiological technology have permitted reassessment of intravenous angiography in the evaluation of cerebrovascular disorders. Although digital subtraction angiography is a relatively new technique, it has rapidly gained a widespread acceptance. It has extended the use of angiography to outpatients and to people in whom conventional angiography is contraindicated. This reliable, safe, and relatively noninvasive technique offers the user two benefits: real-time subtraction and enhanced image quality. The system allows angiographic evaluation of the extracranial and intracranial vessels by means of intravenous injection of contrast material. Extracranial studies clearly demonstrate stenoses and occlusions of the major cervicocephalic arteries. Intracranial studies usually detect major cerebrovascular occlusions and provide insight into the collateral flow patterns. Intravenous digital subtraction angiography permits accurate assessment of cervicocephalic vessels after surgical repair. Although intravenous digital subtraction angiography obviates the need for conventional angiography in many cases, movements from the patients, or superimposition of vascular structures can substantially degrade the quality of the images. Digital subtraction angiography with intra-arterial injection of contrast medium will be contemplated in patients with poor intravenous digital subtraction angiography studies prior to surgery [fr

  11. Intraindividual assessment of the thoracic aorta using contrast and non-contrast-enhanced MR angiography

    International Nuclear Information System (INIS)

    Tengg-Kobligk, Hendrik von; Gruenberg, K.M.; Giesel, F.L.; Ley-Zaporozhan, J.; Ley, S.; Henninger, V.; Kauczor, H.U.; Radiologische Universitaetsklinik Heidelberg; Boeckler, D.; Krummenauer, F.

    2009-01-01

    To avoid intravenous contrast media application, new MRA sequences using inherent blood contrast are available. The clinical use of these non-contrast-enhanced MRA (non-CE-MRA) sequences is still limited for the aorta. Thus, the goal was to compare a standard CE-MRA with a non-CE-MRA for the thoracic aorta. Ethics committee approval and informed consent were obtained. CE-MRA and non-CE-MRA (1.5T) were performed in the same 50 healthy volunteers (mean age: 48). CE-MRA: GRE-Turbo-Flash-3D (1.2 x 1.2 x 1.6 mm 3 ), 0.15 mmol Gd/kg, TA 22 ± 2sec. Non-CE-MRA: Respiratory-and cardiac-gated, T 2-prepared 3D-trueFISP (1.2 x 1.2 x 1.3 mm 3 ), TA 14 ± 5 min. Assessment included (3 readers, consensus): image quality (sharpness of vessel wall, signal homogeneity, artifacts) at the ascending aorta, arch, descending aorta and supra-aortic vessels. The image quality in the ascending aorta was rated 'excellent' in 78 %, 'moderate' in 22 %, 'poor' in 0 % for non-CE-MRA versus 22 %, 50 %, and 28 % for CE-MRA (Cohen's kappa = 29 %, McNemar p < 0.001). In a comparison of non-CE-MRA versus CE-MRA, the aortic arch and descending aorta showed no significant difference (kappa = 58 %/p = 0.250 and kappa = 100 %/p 1.000, respectively). Supra-aortic vessels were rated 'excellent' 45 %/49 %, 'moderate' 30 %/49 % and 'poor' 13 %/2 %, 12 % of supra-aortic vessels were visualized < 1 cm at non-CE-MRA. (orig.)

  12. Comparison of spiral CT angiography vs digital subtraction angiography in the evaluation of living kidney donors

    Directory of Open Access Journals (Sweden)

    Santosh Kumar

    2002-01-01

    Full Text Available Recent reports suggest that spiral computed tomographic (CT angiography could replace conventional angiogra-phy and intravenous urography (IVU for the assessment of potential live kidney donors. The purpose of this study was to assess the accuracy of spiral CT in kidney donor workup. 10 consecutive renal donors had IVU, percutane-ous transfemoral selective renal angiography and spiral CT angiography between January and March 2001. The spiral CT and renal angiograms were assessed independ-ently by two radiologists. The number of renal arteries, pres-ence or absence of renal artery stenoses and associated parenchymal abnormalities were assessed. A total of 27 renal arteries were detected. Transverse scans viewed in a tine loop format with maximum intensity projection and shaded surface display detected all 27 vessels. All 27 ves-sels were detected by conventional catheter angiography. A simple renal cyst was noted in both spiral CT and con-ventional angiogram. Venous anatomy including a retroaortic renal vein was visualized in spiral CT angiogram but not visualized by conventional angiography. Spiral CT angiography performed as an outpatient procedure is less invasive, less expensive, and provides good images of the arterial and venous anatomy in addition to the visualiza-tion of the other abdominal viscera. A plain X-ray of the abdomen was taken 15 rains after injection of contrast to acquire an IVU like image. Spiral CT angiography has the potential to replace conventional catheter angiography and IVU in the assessment of renal donors.

  13. Assessment of left ventricular function and mass in dual-source computed tomography coronary angiography

    Energy Technology Data Exchange (ETDEWEB)

    Jensen, Christoph J., E-mail: c.jensen@contilia.d [Department of Cardiology and Angiology, Elisabeth Hospital, Essen (Germany); Jochims, Markus [Department of Cardiology and Angiology, Elisabeth Hospital, Essen (Germany); Hunold, Peter; Forsting, Michael; Barkhausen, Joerg [Department of Diagnostic and Interventional Radiology and Neuroradiology, University of Essen (Germany); Sabin, Georg V.; Bruder, Oliver [Department of Cardiology and Angiology, Elisabeth Hospital, Essen (Germany); Schlosser, Thomas [Department of Diagnostic and Interventional Radiology and Neuroradiology, University of Essen (Germany)

    2010-06-15

    Purpose: To quantify left ventricular (LV) function and mass (LVM) derived from dual-source computed tomography (DSCT) and the influence of beta-blocker administration compared to cardiac magnetic resonance imaging (CMR). Methods: Thirty-two patients undergoing cardiac DSCT and CMR were included, where of fifteen received metoprolol intravenously before DSCT. LV parameters were calculated by the disc-summation method (DSM) and by a segmented region-growing algorithm (RGA). All data sets were analyzed by two blinded observers. Interobserver agreement was tested by the intraclass correlation coefficient. Results.: 1. Using DSM LV parameters were not statistically different between DSCT and CMR in all patients (DSCT vs. CMR: EF 63 {+-} 8% vs. 64 {+-} 8%, p = 0.47; EDV 136 {+-} 36 ml vs. 138 {+-} 35 ml, p = 0.66; ESV 52 {+-} 21 ml vs. 52 {+-} 22 ml, p = 0.61; SV 83 {+-} 22 ml vs. 87 {+-} 19 ml, p = 0.22; CO 5.4 {+-} 0.9 l/min vs. 5.7 {+-} 1.2 l/min, p = 0.09, LVM 132 {+-} 33 g vs. 132 {+-} 33 g, p = 0.99). 2. In a subgroup of 15 patients beta-blockade prior to DSCT resulted in a lower ejection fraction (EF), stroke volume (SV), cardiac output (CO) and increase in end systolic volume (ESV) in DSCT (EF 59 {+-} 8% vs. 62 {+-} 9%; SV 73 {+-} 17 ml vs. 81 {+-} 15 ml; CO 5.7 {+-} 1.2 l/min vs. 5.0 {+-} 0.8 l/min; ESV 52 {+-} 27 ml vs. 57 {+-} 24 ml, all p < 0.05). 3. Analyzing the RGA parameters LV volumes were not significantly different compared to DSM, whereas LVM was higher using RGA (177 {+-} 31 g vs. 132 {+-} 33 g, p < 0.05). Interobserver agreement was excellent comparing DSM values with best agreement between RGA calculations. Conclusion: Left ventricular volumes and mass can reliably be assessed by DSCT compared to CMR. However, beta-blocker administration leads to statistically significant reduced EF, SV and CO, whereas ESV significantly increases. DSCT RGA reliably analyzes LV function, whereas LVM is overestimated compared to DSM.

  14. Assessment of left ventricular function and mass in dual-source computed tomography coronary angiography

    International Nuclear Information System (INIS)

    Jensen, Christoph J.; Jochims, Markus; Hunold, Peter; Forsting, Michael; Barkhausen, Joerg; Sabin, Georg V.; Bruder, Oliver; Schlosser, Thomas

    2010-01-01

    Purpose: To quantify left ventricular (LV) function and mass (LVM) derived from dual-source computed tomography (DSCT) and the influence of beta-blocker administration compared to cardiac magnetic resonance imaging (CMR). Methods: Thirty-two patients undergoing cardiac DSCT and CMR were included, where of fifteen received metoprolol intravenously before DSCT. LV parameters were calculated by the disc-summation method (DSM) and by a segmented region-growing algorithm (RGA). All data sets were analyzed by two blinded observers. Interobserver agreement was tested by the intraclass correlation coefficient. Results.: 1. Using DSM LV parameters were not statistically different between DSCT and CMR in all patients (DSCT vs. CMR: EF 63 ± 8% vs. 64 ± 8%, p = 0.47; EDV 136 ± 36 ml vs. 138 ± 35 ml, p = 0.66; ESV 52 ± 21 ml vs. 52 ± 22 ml, p = 0.61; SV 83 ± 22 ml vs. 87 ± 19 ml, p = 0.22; CO 5.4 ± 0.9 l/min vs. 5.7 ± 1.2 l/min, p = 0.09, LVM 132 ± 33 g vs. 132 ± 33 g, p = 0.99). 2. In a subgroup of 15 patients beta-blockade prior to DSCT resulted in a lower ejection fraction (EF), stroke volume (SV), cardiac output (CO) and increase in end systolic volume (ESV) in DSCT (EF 59 ± 8% vs. 62 ± 9%; SV 73 ± 17 ml vs. 81 ± 15 ml; CO 5.7 ± 1.2 l/min vs. 5.0 ± 0.8 l/min; ESV 52 ± 27 ml vs. 57 ± 24 ml, all p < 0.05). 3. Analyzing the RGA parameters LV volumes were not significantly different compared to DSM, whereas LVM was higher using RGA (177 ± 31 g vs. 132 ± 33 g, p < 0.05). Interobserver agreement was excellent comparing DSM values with best agreement between RGA calculations. Conclusion: Left ventricular volumes and mass can reliably be assessed by DSCT compared to CMR. However, beta-blocker administration leads to statistically significant reduced EF, SV and CO, whereas ESV significantly increases. DSCT RGA reliably analyzes LV function, whereas LVM is overestimated compared to DSM.

  15. Angiography in angiology

    International Nuclear Information System (INIS)

    Zeitler, E.; Grosse-Vorholt, R.

    1980-01-01

    A review is given of recent developments in angiography including advances in the equipment, in the technique and in image processing. Indications for and interpretation of angiography are discussed and angiographic-therapeutic procedures are considered. (C.F.)

  16. Diagnostic Accuracy of Quantitative Flow Ratio for Assessing Myocardial Ischemia in Prior Myocardial Infarction.

    Science.gov (United States)

    Emori, Hiroki; Kubo, Takashi; Kameyama, Takeyoshi; Ino, Yasushi; Matsuo, Yoshiki; Kitabata, Hironori; Terada, Kosei; Katayama, Yosuke; Aoki, Hiroshi; Taruya, Akira; Shimamura, Kunihiro; Ota, Shingo; Tanaka, Atsushi; Hozumi, Takeshi; Akasaka, Takashi

    2018-02-23

    A novel index of the functional severity of coronary stenosis, quantitative flow ratio (QFR), may not consider the amount of viable myocardium in prior myocardial infarction (MI) because QFR is calculated from 3D quantitative coronary angiography.Methods and Results:We analyzed QFR (fixed-flow QFR [fQFR] and contrast-flow QFR [cQFR]) and fractional flow reserve (FFR) in prior-MI-related coronary arteries (n=75) and non-prior-MI-related coronary arteries (n=75). Both fQFR and cQFR directly correlated with FFR in the prior-MI-related coronary arteries (fQFR: r=0.84, Pdifference between fQFR and FFR in the non-prior-MI-related coronary arteries. The value of cQFR minus FFR was significantly lower in the prior-MI-related coronary arteries compared with the non-prior-MI-related coronary arteries (-0.02±0.06 vs. 0.00±0.04, P=0.010). The diagnostic accuracy of fQFR ≤0.8 and cQFR ≤0.8 for predicting FFR ≤0.80 was numerically lower in the prior-MI-related coronary arteries compared with the non-prior-MI-related coronary arteries (fQFR: 77% vs. 87%; and cQFR: 87% vs. 92%). When FFR is used as the gold standard, the accuracy of QFR for assessing the functional severity of coronary stenosis might be reduced in the prior-MI-related coronary arteries compared with non-prior-MI-related coronary arteries.

  17. Towards Developing a Quantitative Literacy/Reasoning Assessment Instrument

    Directory of Open Access Journals (Sweden)

    Eric Gaze

    2014-07-01

    Full Text Available This article reports on the development and implementation of a non-proprietary assessment instrument for Quantitative Literacy/Reasoning. This instrument was based on prior work by Bowdoin College, Colby-Sawyer College, and Wellesley College and was piloted in 2012 and 2013. This article presents a discussion of its development as well as the results of the pilot implementation. This work was supported by a TUES Type 1 grant from the National Science Foundation.

  18. Comprehensive wellbore stability analysis utilizing Quantitative Risk Assessment

    Energy Technology Data Exchange (ETDEWEB)

    Moos, Daniel; Peska, Pavel; Finkbeiner, Thomas [GeoMechanics International, Palo Alto, CA 94303 (United States); Zoback, Mark [Stanford University, Stanford, CA 94305 (United States)

    2003-06-01

    A comprehensive geomechanical approach to wellbore stability requires knowledge of rock strength, pore pressure and the magnitude and orientation of the three principal stresses. These parameters are often uncertain, making confidence in deterministic predictions of the risks associated with instabilities during drilling and production difficult to assess. This paper demonstrates the use of Quantitative Risk Assessment (QRA) to formally account for the uncertainty in each input parameter to assess the probability of achieving a desired degree of wellbore stability at a given mud weight. We also utilize QRA to assess how the uncertainty in each parameter affects the mud weight calculated to maintain stability. In one case study, we illustrate how this approach allows us to compute optimal mud weight windows and casing set points at a deep-water site. In another case study, we demonstrate how to assess the feasibility of underbalanced drilling and open-hole completion of horizontal wells utilizing a comprehensive stability analysis that includes application of QRA.

  19. Assessment of radiation exposure on a dual-source computed tomography-scanner performing coronary computed tomography-angiography

    Energy Technology Data Exchange (ETDEWEB)

    Kirchhoff, S., E-mail: sonja.kirchhoff@med.uni-muenchen.d [Institute of Clinical Radiology, University Hospital Munich - Grosshadern, Ludwig Maximilians-Universitaet Muenchen, Klinikum Grosshadern, Marchioninistrasse 15, 81377 Munich (Germany); Herzog, P., E-mail: peter.herzog@med.uni-muenchen.d [Institute of Clinical Radiology, University Hospital Munich - Grosshadern, Ludwig Maximilians-Universitaet Muenchen, Klinikum Grosshadern, Marchioninistrasse 15, 81377 Munich (Germany); Johnson, T., E-mail: Thorsten.johnson@med.uni-muenchen.d [Institute of Clinical Radiology, University Hospital Munich - Grosshadern, Ludwig Maximilians-Universitaet Muenchen, Klinikum Grosshadern, Marchioninistrasse 15, 81377 Munich (Germany); Boehm, H., E-mail: holger.boehm@med.uni-muenchen.d [Institute of Clinical Radiology, University Hospital Munich - Grosshadern, Ludwig Maximilians-Universitaet Muenchen, Klinikum Grosshadern, Marchioninistrasse 15, 81377 Munich (Germany); Nikolaou, K., E-mail: konstantin.nikolaou@med.uni-muenchen.d [Institute of Clinical Radiology, University Hospital Munich - Grosshadern, Ludwig Maximilians-Universitaet Muenchen, Klinikum Grosshadern, Marchioninistrasse 15, 81377 Munich (Germany); Reiser, M.F., E-mail: maximilian.reiser@med.uni-muenchen.d [Institute of Clinical Radiology, University Hospital Munich - Grosshadern, Ludwig Maximilians-Universitaet Muenchen, Klinikum Grosshadern, Marchioninistrasse 15, 81377 Munich (Germany); Becker, C.H., E-mail: christoph.becker@med.uni-muenchen.d [Institute of Clinical Radiology, University Hospital Munich - Grosshadern, Ludwig Maximilians-Universitaet Muenchen, Klinikum Grosshadern, Marchioninistrasse 15, 81377 Munich (Germany)

    2010-06-15

    Objective: The radiation exposure of a dual-source-64-channel multi-detector-computed-tomography-scanner (Somatom-Defintion, Siemens, Germany) was assessed in a phantom-study performing coronary-CT-angiography (CTCA) in comparison to patients' data randomly selected from routine scanning. Methods: 240 CT-acquisitions of a computed tomography dose index (CTDI)-phantom (PTW, Freiburg, Germany) were performed using a synthetically generated Electrocardiography (ECG)-signal with variable heart rates (30-180 beats per minute (bpm)). 120 measurements were acquired using continuous tube-output; 120 measurements were performed using ECG-synchronized tube-modulation. The pulsing window was set at minimum duration at 65% of the cardiac cycle between 30 and 75 bpm. From 90-180 bpm the pulsing window was set at 30-70% of the cardiac cycle. Automated pitch adaptation was always used. A comparison between phantom CTDI and two patient groups' CTDI corresponding to the two pulsing groups was performed. Results: Without ECG-tube-modulation CDTI-values were affected by heart-rate-changes resulting in 85.7 mGray (mGy) at 30 and 45 bpm, 65.5 mGy/60 bpm, 54.7 mGy/75 bpm, 46.5 mGy/90 bpm, 34.2 mGy/120 bpm, 27.0 mGy/150 bpm and 22.1 mGy/180 bpm equal to effective doses between 14.5 mSievert (mSv) at 30/45 bpm and 3.6 mSv at 180 bpm. Using ECG-tube-modulation these CTDI-values resulted: 32.6 mGy/30 bpm, 36.6 mGy/45 bpm, 31.4 mGy/60 bpm, 26.8 mGy/75 bpm, 23.7 mGy/90 bpm, 19.4 mGy/120 bpm, 17.2 mGy/150 bpm and 15.6 mGy/180 bpm equal to effective doses between 5.5 mSv at 30 bpm and 2.6 mSv at 180 bpm. Significant CTDI-differences were found between patients with lower/moderate and higher heart rates in comparison to the phantom CTDI-results. Conclusions: Dual source CTCA is particularly dose efficient at high heart rates when automated pitch adaptation, especially in combination with ECG-based tube-modulation is used. However in clinical routine scanning for patients with higher

  20. Quantitative reliability assessment for safety critical system software

    International Nuclear Information System (INIS)

    Chung, Dae Won; Kwon, Soon Man

    2005-01-01

    An essential issue in the replacement of the old analogue I and C to computer-based digital systems in nuclear power plants is the quantitative software reliability assessment. Software reliability models have been successfully applied to many industrial applications, but have the unfortunate drawback of requiring data from which one can formulate a model. Software which is developed for safety critical applications is frequently unable to produce such data for at least two reasons. First, the software is frequently one-of-a-kind, and second, it rarely fails. Safety critical software is normally expected to pass every unit test producing precious little failure data. The basic premise of the rare events approach is that well-tested software does not fail under normal routine and input signals, which means that failures must be triggered by unusual input data and computer states. The failure data found under the reasonable testing cases and testing time for these conditions should be considered for the quantitative reliability assessment. We will present the quantitative reliability assessment methodology of safety critical software for rare failure cases in this paper

  1. Off-pump Versus On-pump Coronary Artery Bypass Surgery: Graft Patency Assessment With Coronary Computed Tomographic Angiography: A Prospective Multicenter Randomized Controlled Pilot Study.

    Science.gov (United States)

    Noiseux, Nicolas; Stevens, Louis-Mathieu; Chartrand-Lefebvre, Carl; Soulez, Gilles; Prieto, Ignacio; Basile, Fadi; Mansour, Samer; Dyub, Adel M; Kieser, Teresa M; Lamy, André

    2017-11-01

    A large multicenter randomized trial (RCT) is needed to assess off-pump coronary artery bypass graft (CABG) patency when performed by skilled surgeons. This prospective multicenter randomized pilot study compares graft patency after on-pump and off-pump techniques and addresses the feasibility of such an RCT. Consecutive patients were prospectively recruited for ≥64-slice computed tomography angiography graft patency assessment 1 year after randomization to off-pump or on-pump CABG. Blinded assessment of graft patency was performed, and the results were categorized as normal, ≥50% stenosis, or occlusion. A multilevel model with random effects on the patient was used to account for correlation of results in patients with multiple grafts. A total of 157 patients (3 centers, 84 off-pump and 73 on-pump patients, 512 grafts, assessability rate 98.4%) were included. Patency index (% nonoccluded grafts) was 89% for the off-pump technique and 95% for the on-pump technique (P=0.09). Patency was similar for arterial and vein grafts (both 92%; P=0.88), as well as between target territories (89% to 94%; P=0.53). In this pilot study, 1-year graft patency results after off-pump and on-pump surgery were similar. This feasibility trial demonstrates that a large multicenter RCT to compare CABG patency after on-pump with that after off-pump techniques is feasible and can be reliably undertaken using computed tomography angiography.

  2. Computed tomography angiography and perfusion to assess coronary artery stenosis causing perfusion defects by single photon emission computed tomography

    DEFF Research Database (Denmark)

    Rochitte, Carlos E; George, Richard T; Chen, Marcus Y

    2014-01-01

    AIMS: To evaluate the diagnostic power of integrating the results of computed tomography angiography (CTA) and CT myocardial perfusion (CTP) to identify coronary artery disease (CAD) defined as a flow limiting coronary artery stenosis causing a perfusion defect by single photon emission computed...... tomography (SPECT). METHODS AND RESULTS: We conducted a multicentre study to evaluate the accuracy of integrated CTA-CTP for the identification of patients with flow-limiting CAD defined by ≥50% stenosis by invasive coronary angiography (ICA) with a corresponding perfusion deficit on stress single photon...... myocardial infarction, the AUC was 0.90 (95% CI: 0.87-0.94) and in patients without prior CAD the AUC for combined CTA-CTP was 0.93 (95% CI: 0.89-0.97). For the combination of a CTA stenosis ≥50% stenosis and a CTP perfusion deficit, the sensitivity, specificity, positive predictive, and negative predicative...

  3. Non invasive assessment of renal artery using dual MRA techniques compared with invasive renal angiography in cases of renovascular hypertension

    Directory of Open Access Journals (Sweden)

    Y. Ragab

    2011-03-01

    Conclusion: The combined approach of non-invasive CE MRA and PC MRA techniques achieves a very high specificity, PPV and NPV for the detection of renal arterial pathomorphologic features as compared to standard renal angiography. Adding PC MRA to CE MRA helps to differentiate between mild and moderate stenoses as well as moderate and sever arterial stenotic lesions. So, CE MRA is a morphological test while PC MRA helps in grading the arterial stenoses.

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

    Energy Technology Data Exchange (ETDEWEB)

    Chandrashekhar, Guruprasadh, E-mail: cguruprasadh@gmail.com [Departments of Radiodiagnosis and Imaging, Post Graduate Institute of Medical Education and Research, Sector-12, Chandigarh 160012 (India); Sodhi, Kushaljit Singh, E-mail: sodhiks@gmail.com [Departments of Radiodiagnosis and Imaging, Post Graduate Institute of Medical Education and Research, Sector-12, Chandigarh 160012 (India); Saxena, Akshay Kumar, E-mail: fatakshay@yahoo.com [Departments of Radiodiagnosis and Imaging, Post Graduate Institute of Medical Education and Research, Sector-12, Chandigarh 160012 (India); Rohit, Manoj Kumar, E-mail: rohitmanoj@gmail.com [Department of Pediatric Cardiology, Post Graduate Institute of Medical Education and Research, Sector-12, Chandigarh 160012 (India); Khandelwal, Niranjan, E-mail: khandelwaln@hotmail.com [Departments of Radiodiagnosis and Imaging, Post Graduate Institute of Medical Education and Research, Sector-12, Chandigarh 160012 (India)

    2012-12-15

    Objective: To study the correlation of low-dose 64-row multi-detector computed tomography (MDCT) with echocardiography and cardiac catheterization angiography (CCA) in the assessment of pulmonary arterial anatomy in children with cyanotic congenital heart disease (CCHD). Materials and methods: This prospective study included 105 children (74 males, 31 females) with CCHD, in the age group of 2 months to 20 years, who underwent 64-row MDCT examination (low-dose CT protocol), echocardiography and CCA for the assessment of pulmonary arteries, including visualization, presence of confluence, stenosis and collaterals. Statistical analysis was performed using the non-parametric statistical analysis test to evaluate the concordance or discordance between echocardiography, MDCT and CCA. Results: 64-row MDCT detected significantly more main and branch pulmonary arteries, patent pulmonary confluences, and more cases of pulmonary artery stenosis. CCA detected more major aorto-pulmonary collaterals than MDCT, whereas echocardiography failed to identify these major aorto-pulmonary collaterals. The effective CT radiation dose to patients less than 2 years of age was in the range of 0.7–2.5 mSv, where as the dose in patients more than 2 years of age ranged from that of 2.1 to 4.2 mSv, which is much less than the radiation dose reported in cardiac catheterization angiography. Conclusion: In cases where cardiac MRI cannot be performed, or is not sufficiently informative, low-dose 64-row MDCT correlates well with CCA and can provide adequate information about pulmonary arterial anatomy in children with cyanotic congenital heart disease, and can replace invasive cardiac catheterization angiography with markedly reduced radiation dosage to the patient.

  5. Non-contrast-enhanced 4D MR angiography with STAR spin labeling and variable flip angle sampling: a feasibility study for the assessment of Dural Arteriovenous Fistula

    International Nuclear Information System (INIS)

    Jang, Jinhee; Kim, Bom-yi; Choi, Hyun Seok; Jung, So-Lyung; Ahn, Kook-Jin; Kim, Bum-soo; Schmitt, Peter; Kim, Inseong; Paek, Munyoung

    2014-01-01

    This study aimed to evaluate the feasibility of non-contrast-enhanced 4D magnetic resonance angiography (NCE 4D MRA) with signal targeting with alternative radiofrequency (STAR) spin labeling and variable flip angle (VFA) sampling in the assessment of dural arteriovenous fistula (DAVF) in the transverse sinus. Nine patients underwent NCE 4D MRA for the evaluation of DAVF in the transverse sinus at 3 T. One patient was examined twice, once before and once after the interventional treatment. All patients also underwent digital subtraction angiography (DSA) and/or contrast-enhanced magnetic resonance angiography (CEMRA). For the acquisition of NCE 4D MRA, a STAR spin tagging method was used, and a VFA sampling was applied in the data readout module instead of a constant flip angle. Two readers evaluated the NCE 4D MRA data for the diagnosis of DAVF and its type with consensus. The results were compared with those from DSA and/or CEMRA. All patients underwent NCE 4D MRA without any difficulty. Among seven patients with patent DAVFs, all cases showed an early visualization of the transverse sinus on NCE 4D MRA. Except for one case, the type of DAVF of NCE 4D MRA was agreed with that of reference standard study. Cortical venous reflux (CVR) was demonstrated in two cases out of three patients with CVR. NCE 4D MRA with STAR tagging and VFA sampling is technically and clinically feasible and represents a promising technique for assessment of DAVF in the transverse sinus. Further technical developments should aim at improvements of spatial and temporal coverage. (orig.)

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

    International Nuclear Information System (INIS)

    Chandrashekhar, Guruprasadh; Sodhi, Kushaljit Singh; Saxena, Akshay Kumar; Rohit, Manoj Kumar; Khandelwal, Niranjan

    2012-01-01

    Objective: To study the correlation of low-dose 64-row multi-detector computed tomography (MDCT) with echocardiography and cardiac catheterization angiography (CCA) in the assessment of pulmonary arterial anatomy in children with cyanotic congenital heart disease (CCHD). Materials and methods: This prospective study included 105 children (74 males, 31 females) with CCHD, in the age group of 2 months to 20 years, who underwent 64-row MDCT examination (low-dose CT protocol), echocardiography and CCA for the assessment of pulmonary arteries, including visualization, presence of confluence, stenosis and collaterals. Statistical analysis was performed using the non-parametric statistical analysis test to evaluate the concordance or discordance between echocardiography, MDCT and CCA. Results: 64-row MDCT detected significantly more main and branch pulmonary arteries, patent pulmonary confluences, and more cases of pulmonary artery stenosis. CCA detected more major aorto-pulmonary collaterals than MDCT, whereas echocardiography failed to identify these major aorto-pulmonary collaterals. The effective CT radiation dose to patients less than 2 years of age was in the range of 0.7–2.5 mSv, where as the dose in patients more than 2 years of age ranged from that of 2.1 to 4.2 mSv, which is much less than the radiation dose reported in cardiac catheterization angiography. Conclusion: In cases where cardiac MRI cannot be performed, or is not sufficiently informative, low-dose 64-row MDCT correlates well with CCA and can provide adequate information about pulmonary arterial anatomy in children with cyanotic congenital heart disease, and can replace invasive cardiac catheterization angiography with markedly reduced radiation dosage to the patient.

  7. HERMES docking/berthing system pilot study. Quantitative assessment

    International Nuclear Information System (INIS)

    Munoz Blasco, J.; Goicoechea Sanchez, F.J.

    1993-01-01

    This study falls within the framework of the incorporation of quantitative risk assessment to the activities planned for the ESA-HERMES project (ESA/ CNES). The main objective behind the study was the analysis and evaluation of the potential contribution of so-called probabilistic or quantitative safety analysis to the optimization of the safety development process for the systems carrying out the safety functions required by the new and complex HERMES Space Vehicle. For this purpose, a pilot study was considered a good start in quantitative safety assessments (QSA), as this approach has been frequently used in the past to establish a solid base in large-scale QSA application programs while avoiding considerable economic risks. It was finally decided to select the HERMES docking/berthing system with Man Tender Free Flyer as the case-study. This report describes the different steps followed in the study, along with the main insights obtained and the general conclusions drawn from the study results. (author)

  8. Qualitative and quantitative ultrasound assessment of gastric content.

    Science.gov (United States)

    Bisinotto, Flora Margarida Barra; Pansani, Patrícia Luísa; Silveira, Luciano Alves Matias da; Naves, Aline de Araújo; Peixoto, Ana Cristina Abdu; Lima, Hellen Moreira de; Martins, Laura Bisinotto

    2017-02-01

    Pulmonary aspiration of the gastric contents is one of the most feared complications in anesthesia. Its prevention depends on preoperative fasting as well as identification of risky patients. A reliable diagnostic tool to assess gastric volume is currently lacking. The aim of this study performed on volunteers was to evaluate the feasibility of ultrasonography to identify qualitative and quantitative gastric content. A standardized gastric scanning protocol was applied on 67 healthy volunteers to assess the gastric antrum in four different situations: fasting, after ingesting clear fluid, milk and a solid meal. A qualitative and quantitative assessment of the gastric content in the antrum was performed by a blinded sonographer. The antrum was considered either as empty, or containing clear or thick fluid, or solids. Total gastric volume was predicted based on a cross-sectional area of the antrum. A p-value less than 0.05 was considered statistically significant. For each type of gastric content, the sonographic characteristics of the antrum and its content were described and illustrated. Sonographic qualitative assessment allowed to distinguish between an empty stomach and one with different kinds of meal. The predicted gastric volume was significantly larger after the consumption of any food source compared to fasting. Bedside sonography can determine the nature of gastric content. It is also possible to estimate the difference between an empty gastric antrum and one that has some food in it. Such information may be useful to estimate the risk of aspiration, particularly in situations when prandial status is unknown or uncertain.

  9. Simulation evaluation of quantitative myocardial perfusion assessment from cardiac CT

    Science.gov (United States)

    Bindschadler, Michael; Modgil, Dimple; Branch, Kelley R.; La Riviere, Patrick J.; Alessio, Adam M.

    2014-03-01

    Contrast enhancement on cardiac CT provides valuable information about myocardial perfusion and methods have been proposed to assess perfusion with static and dynamic acquisitions. There is a lack of knowledge and consensus on the appropriate approach to ensure 1) sufficient diagnostic accuracy for clinical decisions and 2) low radiation doses for patient safety. This work developed a thorough dynamic CT simulation and several accepted blood flow estimation techniques to evaluate the performance of perfusion assessment across a range of acquisition and estimation scenarios. Cardiac CT acquisitions were simulated for a range of flow states (Flow = 0.5, 1, 2, 3 ml/g/min, cardiac output = 3,5,8 L/min). CT acquisitions were simulated with a validated CT simulator incorporating polyenergetic data acquisition and realistic x-ray flux levels for dynamic acquisitions with a range of scenarios including 1, 2, 3 sec sampling for 30 sec with 25, 70, 140 mAs. Images were generated using conventional image reconstruction with additional image-based beam hardening correction to account for iodine content. Time attenuation curves were extracted for multiple regions around the myocardium and used to estimate flow. In total, 2,700 independent realizations of dynamic sequences were generated and multiple MBF estimation methods were applied to each of these. Evaluation of quantitative kinetic modeling yielded blood flow estimates with an root mean square error (RMSE) of ~0.6 ml/g/min averaged across multiple scenarios. Semi-quantitative modeling and qualitative static imaging resulted in significantly more error (RMSE = ~1.2 and ~1.2 ml/min/g respectively). For quantitative methods, dose reduction through reduced temporal sampling or reduced tube current had comparable impact on the MBF estimate fidelity. On average, half dose acquisitions increased the RMSE of estimates by only 18% suggesting that substantial dose reductions can be employed in the context of quantitative myocardial

  10. Catheter Angiography

    Medline Plus

    Full Text Available ... machine produces a small burst of radiation that passes through the body, recording an image on photographic ... By selecting the arteries through which the catheter passes, it is possible to assess vessels in several ...

  11. New developments in quantitative risk assessment of campylobacteriosis

    DEFF Research Database (Denmark)

    Havelaar, Arie; Nauta, Maarten

    Quantitative microbiological risk assessment (QMRA) is now broadly accepted as an important decision support tool in food safety risk management. It has been used to support decision making at the global level (Codex Alimentarius, FAO and WHO), at the European level (European Food Safety Authority...... technical information is now available in CRAF- the Campylobacter Risk Assessment Framework (www.rivm.nl/craf). Newly published QMRA studies on broiler meat arrive at similar conclusions. A general conclusion of all models is that highly contaminated carcasses contribute most to risk, and that reducing......), in many contries world wide and by the industry. The human health risks associated with Campylobacter on broiler meat have been the subject of many different risk assessment studies, whereas only a few studies have considered other exposure pathways. Models are now available for all stages of the farm...

  12. Objective, Quantitative, Data-Driven Assessment of Chemical Probes.

    Science.gov (United States)

    Antolin, Albert A; Tym, Joseph E; Komianou, Angeliki; Collins, Ian; Workman, Paul; Al-Lazikani, Bissan

    2018-02-15

    Chemical probes are essential tools for understanding biological systems and for target validation, yet selecting probes for biomedical research is rarely based on objective assessment of all potential compounds. Here, we describe the Probe Miner: Chemical Probes Objective Assessment resource, capitalizing on the plethora of public medicinal chemistry data to empower quantitative, objective, data-driven evaluation of chemical probes. We assess >1.8 million compounds for their suitability as chemical tools against 2,220 human targets and dissect the biases and limitations encountered. Probe Miner represents a valuable resource to aid the identification of potential chemical probes, particularly when used alongside expert curation. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  13. Integrating a quantitative risk appraisal in a health impact assessment

    DEFF Research Database (Denmark)

    Adám, Balázs; Molnár, Agnes; Gulis, Gabriel

    2013-01-01

    BACKGROUND: Although the quantification of health outcomes in a health impact assessment (HIA) is scarce in practice, it is preferred by policymakers, as it assists various aspects of the decision-making process. This article provides an example of integrating a quantitative risk appraisal...... in an HIA performed for the recently adopted Hungarian anti-smoking policy which introduced a smoking ban in closed public places, workplaces and public transport vehicles, and is one of the most effective measures to decrease smoking-related ill health. METHODS: A comprehensive, prospective HIA...

  14. Quantitative proteomic assessment of very early cellular signaling events

    DEFF Research Database (Denmark)

    Dengjel, Joern; Akimov, Vyacheslav; Olsen, Jesper V

    2007-01-01

    Technical limitations have prevented proteomic analyses of events occurring less than 30 s after signal initiation. We developed an automated, continuous quench-flow system allowing quantitative proteomic assessment of very early cellular signaling events (qPACE) with a time resolution of 1 s....... Using this technique, we determined that autophosphorylation of the epidermal growth factor receptor occurs within 1 s after ligand stimulation and is followed rapidly by phosphorylation of the downstream signaling intermediates Src homologous and collagen-like protein and phospholipase C gamma 1....

  15. Spiral CT angiography of splanchnic artery aneurysms. Technique and results

    International Nuclear Information System (INIS)

    Squillaci, E.; Ciolfi, M.G.; Maspes, F.; Simonetti, G.

    1999-01-01

    The aneurysm of visceral vessel are characterized by few or no symptoms and the diagnosis is often occasional. The authors investigated the usefulness of CT angiography in the diagnosis and preoperative assessment in this conditions. In the experience of the authors CT angiography can replace digital subtraction angiography in the diagnosis and preoperative work-up of visceral vessel aneurysms. CT angiography was superior to digital angiography to the evaluation of the lesion exact dimensions in case with large thrombotic component and diffuse wall calcifications [it

  16. Detection of hemodynamic impairment using magnetic resonance angiography in patients with internal carotid artery stenoocclusive disease. Comparison with quantitative brain perfusion single-photon emission computed tomography

    International Nuclear Information System (INIS)

    Hirooka, Ryonoshin; Ogasawara, Kuniaki

    2008-01-01

    Cerebrovascular reactivity (CVR) to acetazolamideis a key parameter in determining the severity of hemodynamic impairment in patients with major cerebral artery occlusive disease. The aim of the present study is to validate the accuracy of magnetic resonance angiography (MRA) for detecting hemodynamic impairment by correlating detectability of the middle cerebral artery obtained by MRA with CVR measured by single-photon emission computed tomography (SPECT) in patients with internal carotid artery (ICA) occlusive disease. Ninety-four patients with chronic ICA occlusion underwent single slab three-dimensional time-of-flight MRA and SPECT. SPECT-CVR was calculated by measured cerebral blood flow before and after acetazolamide challenge. CVR was significantly lower in patients without detection of any portion (M1, M2 or M3) of the MCA than in those with detection of all portions. When SPECT-CVR lower than the mean- 2 standard deviation (SD) obtained in normal subjects was defined as reduced and the SPECT-CVR was assumed as the true determinant of hemodynamic impairment, MRA provided 92% sensitivity and 73% specificity, with 96% negative predictive value for detecting patients with reduced CVR. The present MRA method is effective for the identification of patients with hemodynamic impairment. (author)

  17. Relationship between diverse patient body size- and image acquisition-related factors, and quantitative and qualitative image quality in coronary computed tomography angiography: a multicenter observational study.

    Science.gov (United States)

    Utsunomiya, Daisuke; Tanaka, Ryoichi; Yoshioka, Kunihiro; Awai, Kazuo; Mochizuki, Teruhito; Matsunaga, Naofumi; Ichikawa, Tomoaki; Kanematsu, Masayuki; Kim, Tonsok; Yamashita, Yasuyuki

    2016-08-01

    We investigated the effects of patient- and image acquisition-related factors on the image quality in coronary CT angiography (CCTA). We enrolled 1197 patients (728 men; 65 ± 12 years). All underwent CCTA under the routine scan protocol in 23 participating hospitals. The subjective image quality (3-point Likert scale: excellent, good, and poor) and the attenuation of the left and right coronary artery (LCA, RCA) were recorded; the effects of patient and image acquisition-related factors on vascular attenuation were then compared. The mean LCA attenuation was 515.2 ± 65.8 (excellent), 401.4 ± 63.4 (good), and 319.5 ± 47.6 HU (poor). The corresponding RCA attenuation was 496.6 ± 67.6, 390.5 ± 58.5, and 308.5 ± 50.7 HU, respectively. Univariate analysis revealed significant associations between sufficient coronary attenuation (> 400 HU) and the age, gender, body surface area (BSA), number of detectors, contrast synchronization, scan mode, and the fractional contrast dose. Multivariate analysis revealed that the bolus tracking method, prospective electrocardiogram gating, and fractional contrast dose were significantly associated with sufficient coronary enhancement. BSA and fractional contrast dose are the most important patient- and image acquisition-related factors for sufficient coronary attenuation in CCTA.

  18. Short Course Introduction to Quantitative Mineral Resource Assessments

    Science.gov (United States)

    Singer, Donald A.

    2007-01-01

    This is an abbreviated text supplementing the content of three sets of slides used in a short course that has been presented by the author at several workshops. The slides should be viewed in the order of (1) Introduction and models, (2) Delineation and estimation, and (3) Combining estimates and summary. References cited in the slides are listed at the end of this text. The purpose of the three-part form of mineral resource assessments discussed in the accompanying slides is to make unbiased quantitative assessments in a format needed in decision-support systems so that consequences of alternative courses of action can be examined. The three-part form of mineral resource assessments was developed to assist policy makers evaluate the consequences of alternative courses of action with respect to land use and mineral-resource development. The audience for three-part assessments is a governmental or industrial policy maker, a manager of exploration, a planner of regional development, or similar decision-maker. Some of the tools and models presented here will be useful for selection of exploration sites, but that is a side benefit, not the goal. To provide unbiased information, we recommend the three-part form of mineral resource assessments where general locations of undiscovered deposits are delineated from a deposit type's geologic setting, frequency distributions of tonnages and grades of well-explored deposits serve as models of grades and tonnages of undiscovered deposits, and number of undiscovered deposits are estimated probabilistically by type. The internally consistent descriptive, grade and tonnage, deposit density, and economic models used in the design of the three-part form of assessments reduce the chances of biased estimates of the undiscovered resources. What and why quantitative resource assessments: The kind of assessment recommended here is founded in decision analysis in order to provide a framework for making decisions concerning mineral

  19. Quantitative cholescintigraphy in the assessment of choledochoduodenal bile flow

    Energy Technology Data Exchange (ETDEWEB)

    Cicala, M.; Scopinaro, F.; Corazziari, E.; Vignoni, A.; Viscardi, A.; Habib, F.I.; Torsoli, A. (Universita La Sapienza, Rome (Italy))

    1991-04-01

    Quantitative cholescintigraphy has been proposed as a noninvasive method to assess function of the sphincter of Oddi in cholecystectomized subjects. The present study evaluated several quantitative cholescintigraphic variables to assess their time-related variability as well as their capability to detect delay of choledochoduodenal bile flow. Cholescintigraphy with 2,6-diethylphenylcarbahoylmethyl diacetic acid 99mTc was performed in 24 cholecystectomized patients with recurrent biliary-like pain, laboratory evidence of bile stasis, normal hepatocellular function tests, and no evidence of choledocholithiasis. The study was also performed in 26 asymptomatic cholecystectomized subjects and repeated at 2-week intervals during identical experimental conditions in 10 of them. Of the following quantitative cholescintigraphic variables investigated, (a) hepatic T peak, (b) 50% hepatic retention (T peak, 1/2), (c) percent hepatic retention at 30 minutes, (d) percent hepatic retention at 40 minutes, (e) vein-hepatic hilum transit time, (f) vein-duodenum transit time, and (g) hepatic hilum-duodenum transit time, only the hepatic hilum-duodenum transit time showed a statistically significant correlation between the duplicate studies. Only vein-duodenum transit time and hepatic hilum-duodenum transit time discriminated the symptomatic from the asymptomatic patients; of the two variables, however, hepatic hilum-duodenum transit time showed less intrasubject variability and no overlap between the two groups of patients. Hepatic hilum-duodenum transit time showed a positive linear correlation with the maximum diameter of the choledochus. It is concluded that in cholecystectomized patients, the hepatic hilum-duodenum transit time appears to detect a delay of bile flow into the intestine better than any other cholescintigraphic variable.

  20. Placental characteristics in monochorionic twins with selective intrauterine growth restriction assessed by gradient angiography and three-dimensional reconstruction.

    Science.gov (United States)

    Gou, Chenyu; Li, Meizhi; Zhang, Xiaoling; Liu, Xiangzhen; Huang, Xuan; Zhou, Yi; Fang, Qun

    2017-11-01

    To investigate the placental characteristics in selective intrauterine growth restriction (sIUGR) using gradient angiography and three-dimensional (3D) reconstruction from computed tomography (CT) scan data. This study included 23 sIUGR cases and 16 monochorionic twin-pregnancies without sIUGR. We injected nonionic iodinated contrast agents into the umbilical arteries and veins. Placental characteristics were analyzed after CT scanning and 3D reconstruction. 73.9% of smaller twins in sIUGR cases had marginal or velamentous cord insertions and less placental sharing. The terminal branch of the arterial tree was scored III-IV in smaller sIUGR twins, while it was scored V-VII in normal monochorionic twins and larger sIUGR twins. Arterio-arterial (A-A) anastomoses presented in all monochorionic placentas. Veno-venous (V-V) anastomoses present in 83.3% (5/6) of Type III sIUGR cases, which was higher than observed in Type I-II cases. The mean diameters of A-A and V-V anastomoses were larger in Type III sIUGR cases. Gradient angiography and 3D placental models displayed different placental angioarchitectures and voluminal placental sharing among three types of sIUGR cases. Placental dysplasia in the smaller twin may cause abnormal cord insertion and unequal placental sharing. The inter-twin anatomoses influence the umbilical cord artery (UA) Doppler and natural pathogenesis of sIUGR.

  1. Use of indigo carmine angiography to qualitatively assess adequate distal perfusion after endovascular revascularization in critical limb ischemia.

    Science.gov (United States)

    Higashimori, Akihiro; Yokoi, Yoshiaki

    2015-06-01

    To report a novel technique to visualize the efficacy of revascularization in critical limb ischemia patients with ischemic foot ulcers. An 80-year-old man was admitted with nonhealing ulcers on his left second toe and lateral border of the foot owing to in-stent restenosis of the left popliteal artery. After dilation of the popliteal in-stent restenosis, below-the-knee angiography revealed that the anterior tibial artery (ATA) was occluded, the posterior tibial artery was hypoplastic, and the peroneal artery was enlarged, with 2 plantar arteries. To evaluate the foot circulation before performing additional procedures, a 4-F multipurpose catheter was advanced into the peroneal artery, and 5 mL of indigo carmine was injected. Immediately, the patient's second toe and lateral border ulcers were dyed blue. We concluded that sufficient blood flow had been obtained to the ulcerated area by balloon angioplasty alone, so the procedure was terminated. The ulcers completely healed at 1 month. Indigo carmine angiography provides visual information on foot perfusion, yielding new insights into microcirculation and helping to determine the effectiveness of treatment and procedure endpoint. © The Author(s) 2015.

  2. Quantitative Vulnerability Assessment of Cyber Security for Distribution Automation Systems

    Directory of Open Access Journals (Sweden)

    Xiaming Ye

    2015-06-01

    Full Text Available The distribution automation system (DAS is vulnerable to cyber-attacks due to the widespread use of terminal devices and standard communication protocols. On account of the cost of defense, it is impossible to ensure the security of every device in the DAS. Given this background, a novel quantitative vulnerability assessment model of cyber security for DAS is developed in this paper. In the assessment model, the potential physical consequences of cyber-attacks are analyzed from two levels: terminal device level and control center server level. Then, the attack process is modeled based on game theory and the relationships among different vulnerabilities are analyzed by introducing a vulnerability adjacency matrix. Finally, the application process of the proposed methodology is illustrated through a case study based on bus 2 of the Roy Billinton Test System (RBTS. The results demonstrate the reasonability and effectiveness of the proposed methodology.

  3. NecroQuant: quantitative assessment of radiological necrosis

    Science.gov (United States)

    Hwang, Darryl H.; Mohamed, Passant; Varghese, Bino A.; Cen, Steven Y.; Duddalwar, Vinay

    2017-11-01

    Clinicians can now objectively quantify tumor necrosis by Hounsfield units and enhancement characteristics from multiphase contrast enhanced CT imaging. NecroQuant has been designed to work as part of a radiomics pipelines. The software is a departure from the conventional qualitative assessment of tumor necrosis, as it provides the user (radiologists and researchers) a simple interface to precisely and interactively define and measure necrosis in contrast-enhanced CT images. Although, the software is tested here on renal masses, it can be re-configured to assess tumor necrosis across variety of tumors from different body sites, providing a generalized, open, portable, and extensible quantitative analysis platform that is widely applicable across cancer types to quantify tumor necrosis.

  4. Qualitative and quantitative assessment of interior moisture buffering by enclosures

    DEFF Research Database (Denmark)

    Janssen, Hans; Roels, Staf

    2009-01-01

    The significance of interior humidity in attaining sustainable, durable, healthy and comfortable buildings is increasingly recognised. Given their significant interaction, interior humidity appraisals need a qualitative and/or quantitative assessment of interior moisture buffering. While...... suggested protocols for the simple and fast measurement of the moisture buffer potential of interior elements allow qualitative assessment, none of these are currently dependable for a wide range of moisture production regimes. In response to these flaws, this paper introduces the production......-adaptive characterisation of the moisture buffer potential of interior elements and corroborates their superposition toward a room-enclosure moisture buffer potential. It is verified that this enables qualitative comparison of enclosures in relation to interior moisture buffering. It is moreover demonstrated that it forms...

  5. Magnetic resonance angiography (MRA)

    International Nuclear Information System (INIS)

    Arlart, I.P.; Guhl, L.

    1992-01-01

    An account is given in this paper of the physical and technical principles underlying the 'time-of-flight' technique for imaging of vessels by magnetic resonance tomography. Major indications for the new procedure of magnetic resonance angiography at present are intracerebral and extracerebral vessels, with digital subtraction angiography quite often being required to cope with minor alterations (small aneurysms, small occlusions). Magnetic resonance angiography and digital subtraction angiography are compared to each other for advantages and disadvantages. Basically, replacement of radiological angiography by magnetic resonance angiography appears to be possible only within limits, since X-ray diagnostics primarily provides morphological information about vessels, whereas flow dynamics is visualized by the 'time-of-flight' technique. (orig.) [de

  6. Quantitative Cardiac Assessment in Fetal Tetralogy of Fallot.

    Science.gov (United States)

    Jatavan, Phudit; Tongprasert, Fuanglada; Srisupundit, Kasemsri; Luewan, Suchaya; Traisrisilp, Kuntharee; Tongsong, Theera

    2016-07-01

    The purpose of this study was to quantitatively assess cardiac function and biometric parameters in fetuses with a diagnosis of tetralogy of Fallot and compare them to those in healthy fetuses. Two hundred healthy fetuses and 20 fetuses with a diagnosis of classic tetralogy of Fallot were quantitatively assessed for 16 cardiac parameters, including morphologic characteristics and functions. All recruited fetuses were in the second trimester with correct gestational ages. The measured values that were out of normal reference ranges were considered abnormal. Rates of abnormalities of these parameters were compared between the groups. The significant parameters were further analyzed for their sensitivity, specificity, and likelihood ratio. Of the 16 parameters, rates of abnormalities in 7 parameters, including right ventricular wall thickness, peak systolic velocities (PSVs) in the pulmonary artery and aorta, time to peak velocity, or acceleration time, in the pulmonary artery, aortic valve diameter, pulmonary valve diameter, and aortic-to-pulmonary valve diameter ratio, were significantly higher in fetuses with tetralogy of Fallot (P tetralogy of Fallot.

  7. Quantitative assessment with improved FFTBM by signal mirroring

    International Nuclear Information System (INIS)

    Prosek, A.; Leskovar, M.

    2006-01-01

    In the last years the number of quantitative comparisons between experimental and calculated data in the area of nuclear technology has increased. The most widely used was the Fast Fourier Transform Based Method (FFTBM) for accuracy quantification of thermal-hydraulic code calculations, which is being continuously improved. However, when preliminary applying the original FFTBM to a severe accident test in 2005 the need for further optimization was identified. It was observed that FFTBM favours certain trends (e.g. monotonic increasing function). The purpose of the present study was therefore to improve the FFTBM in this respect. This was achieved by signal mirroring. Signal mirroring was proposed for eliminating the edge effect from the signal. The edge effect is present in the signal when the first and the last data point of the time signal are different and the aperiodic signal is treated like a periodic signal in the fast Fourier transform. For the demonstration of the improved FFTBM by signal mirroring the LOFT L2-5 test (large break loss-of-coolant accident) calculations performed in the frame of the Best-Estimate Methods Uncertainty and Sensitivity Evaluation (BEMUSE) programme were used. The results of the quantitative assessment showed that with the improved FFTBM by signal mirroring the analyst can get a better picture how much each discrepancy contributes to the accuracy as assessed by FFTBM. (author)

  8. Relationship of the duke jeopardy score combined with minimal lumen diameter as assessed by computed tomography angiography to the hemodynamic relevance of coronary artery stenosis.

    Science.gov (United States)

    Yu, Mengmeng; Zhao, Yonghong; Li, Wenbin; Lu, Zhigang; Wei, Meng; Zhou, Wenxiao; Zhang, Jiayin

    2018-03-02

    To study the diagnostic performance of the ratio between the Duke jeopardy score (DJS) and the minimal lumen diameter (MLD) (DJS/MLD CT ratio) as assessed by coronary computed tomographic angiography (CTA) for differentiating functionally significant from non-significant coronary artery stenoses, with reference to invasive fractional flow reserve (FFR). Patients who underwent both coronary CTA and FFR measurement during invasive coronary angiography (ICA) within 2 weeks were retrospectively included in the study. Invasive FFR measurement was performed in patients with intermediate to severe coronary stenoseis. DJS/MLD CT ratio and anatomical parameters were recorded. Lesions with FFR ≤0.80 were considered to be functionally significant. One hundred and sixty-one patients with 175 lesions were included into the analysis. Diameter stenosis in CT, area stenosis, plaque burden, lesion length (LL), ICA-based stenosis degree, DJS, LL/MLD 4 ratio, DJS/MLA ratio as well as DJS/MLD ratio were all significantly different between hemodynamically significant and non-significant lesions (pvalue for DJS/MLD CT ratio to be 1.96 (area under curve = 0.863, 95 % confidence interval = 0.803-0.910), yielding a high diagnostic accuracy (86.9%, 152/175). In coronary artery stenoses detected by coronary CTA, the DJS/MLD ratio is able to predict hemodynamic relevance. Copyright © 2018 Society of Cardiovascular Computed Tomography. Published by Elsevier Inc. All rights reserved.

  9. Qualitative and quantitative ultrasound assessment of gastric content

    Directory of Open Access Journals (Sweden)

    Flora Margarida Barra Bisinotto

    Full Text Available Summary Objective: Pulmonary aspiration of the gastric contents is one of the most feared complications in anesthesia. Its prevention depends on preoperative fasting as well as identification of risky patients. A reliable diagnostic tool to assess gastric volume is currently lacking. The aim of this study performed on volunteers was to evaluate the feasibility of ultrasonography to identify qualitative and quantitative gastric content. Method: A standardized gastric scanning protocol was applied on 67 healthy volunteers to assess the gastric antrum in four different situations: fasting, after ingesting clear fluid, milk and a solid meal. A qualitative and quantitative assessment of the gastric content in the antrum was performed by a blinded sonographer. The antrum was considered either as empty, or containing clear or thick fluid, or solids. Total gastric volume was predicted based on a cross-sectional area of the antrum. A p-value less than 0.05 was considered statistically significant. Results: For each type of gastric content, the sonographic characteristics of the antrum and its content were described and illustrated. Sonographic qualitative assessment allowed to distinguish between an empty stomach and one with different kinds of meal. The predicted gastric volume was significantly larger after the consumption of any food source compared to fasting. Conclusion: Bedside sonography can determine the nature of gastric content. It is also possible to estimate the difference between an empty gastric antrum and one that has some food in it. Such information may be useful to estimate the risk of aspiration, particularly in situations when prandial status is unknown or uncertain.

  10. Abdominal MR angiography

    International Nuclear Information System (INIS)

    Wegmueller, H.; Vock, P.

    1993-01-01

    The two techniques currently most often used for MR angiography, those based on time-of-flight effects and on phase-contrast, are introduced, and our results with three-dimensional phase contrast angiography of the abdomen are presented. Several basic differences from other imaging procedures render MR angiography clinically useful for screening for renal artery stenosis in critical situations, such as renal failure or intolerance to contrast agents. In the future, the spectrum of applications of MR angiography will broaden and include other indications, such as portal venous hypertension and follow-up studies after surgical portal systemic shunting. (orig.) [de

  11. Clinical validation of a software for quantitative follow-up of abdominal aortic aneurysm maximal diameter and growth by CT angiography

    International Nuclear Information System (INIS)

    Kauffmann, Claude; Tang, An; Dugas, Alexandre; Therasse, Eric; Oliva, Vincent; Soulez, Gilles

    2011-01-01

    Purpose: To compare the reproducibility and accuracy of abdominal aortic aneurysm (AAA) maximal diameter (D-max) measurements using segmentation software, with manual measurement on double-oblique MPR as a reference standard. Materials and methods: The local Ethics Committee approved this study and waived informed consent. Forty patients (33 men, 7 women; mean age, 72 years, range, 49-86 years) had previously undergone two CT angiography (CTA) studies within 16 ± 8 months for follow-up of AAA ≥35 mm without previous treatment. The 80 studies were segmented twice using the software to calculate reproducibility of automatic D-max calculation on 3D models. Three radiologists reviewed the 80 studies and manually measured D-max on double-oblique MPR projections. Intra-observer and inter-observer reproducibility were calculated by intraclass correlation coefficient (ICC). Systematic errors were evaluated by linear regression and Bland-Altman analyses. Differences in D-max growth were analyzed with a paired Student's t-test. Results: The ICC for intra-observer reproducibility of D-max measurement was 0.992 (≥0.987) for the software and 0.985 (≥0.974) and 0.969 (≥0.948) for two radiologists. Inter-observer reproducibility was 0.979 (0.954-0.984) for the three radiologists. Mean absolute difference between semi-automated and manual D-max measurements was estimated at 1.1 ± 0.9 mm and never exceeded 5 mm. Conclusion: Semi-automated software measurement of AAA D-max is reproducible, accurate, and requires minimal operator intervention.

  12. 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

  13. Quantitative assessment of breast density: comparison of different methods

    International Nuclear Information System (INIS)

    Qin Naishan; Guo Li; Dang Yi; Song Luxin; Wang Xiaoying

    2011-01-01

    Objective: To Compare different methods of quantitative breast density measurement. Methods: The study included sixty patients who underwent both mammography and breast MRI. The breast density was computed automatically on digital mammograms with R2 workstation, Two experienced radiologists read the mammograms and assessed the breast density with Wolfe and ACR classification respectively. Fuzzy C-means clustering algorithm (FCM) was used to assess breast density on MRI. Each assessment method was repeated after 2 weeks. Spearman and Pearson correlations of inter- and intrareader and intermodality were computed for density estimates. Results: Inter- and intrareader correlation of Wolfe classification were 0.74 and 0.65, and they were 0.74 and 0.82 for ACR classification respectively. Correlation between Wolfe and ACR classification was 0.77. High interreader correlation of 0.98 and intrareader correlation of 0.96 was observed with MR FCM measurement. And the correlation between digital mammograms and MRI was high in the assessment of breast density (r=0.81, P<0.01). Conclusion: High correlation of breast density estimates on digital mammograms and MRI FCM suggested the former could be used as a simple and accurate method. (authors)

  14. 3D fusion of coronary CT angiography and CT myocardial perfusion imaging: Intuitive assessment of morphology and function.

    Science.gov (United States)

    von Spiczak, Jochen; Manka, Robert; Mannil, Manoj; Oebel, Sabrina; Hamada, Sandra; Higashigaito, Kai; Klotz, Ernst; Ruschitzka, Frank; Alkadhi, Hatem

    2017-11-01

    The objective of this work was to support three-dimensional fusion of coronary CT angiography (coronary CTA) and CT myocardial perfusion (CT-Perf) data visualizing coronary artery stenoses and corresponding stress-induced myocardial perfusion deficits for diagnostics of coronary artery disease. Twelve patients undergoing coronary CTA/CT-Perf after heart transplantation were included (56 ± 12 years, all males). CT image quality was rated. Coronary diameter stenoses >50% were documented for coronary CTA. Stress-induced perfusion deficits were noted for CT-Perf. A software was implemented facilitating 3D fusion imaging of coronary CTA/CT-Perf data. Coronary arteries and heart contours were segmented automatically. To overcome anatomical mismatch of coronary CTA/CT-Perf image acquisition, perfusion values were projected on the left ventricle as visualized in coronary CTA. Three resulting datasets (coronary tree/heart contour/perfusion values) were fused for combined three-dimensional rendering. 3D fusion was compared with conventional analysis of coronary CTA/CT-Perf data and to results from catheter coronary angiography. CT image quality was rated good-excellent (3.5 ± 0.5, scale 1-4). 3D fusion imaging of coronary CTA/CT-Perf data was feasible in 11/12 patients (92%). One patient (8%) was excluded from further analysis due to severe motion artifacts. 2 of 11 remaining patients (18%) showed both stress-induced perfusion deficits and relevant coronary stenoses. Using 3D fusion imaging, the ischemic region could be correlated to a culprit coronary lesion in one case (1/2 = 50%) and diagnostic findings could be rectified in the other case (1/2 = 50%). Coronary CTA was in full correspondence with catheter coronary angiography. A method for 3D fusion of coronary CTA/CT-Perf is introduced correlating relevant coronary lesions and corresponding stress-induced myocardial perfusion deficits. Copyright © 2017 Society of Cardiovascular Computed Tomography. Published

  15. Quantitative assessment of limb blood flow using Tc-99m labeled red blood cells. Radionuclide venous occlusion plethysmography (RAVOP)

    Energy Technology Data Exchange (ETDEWEB)

    Itoh, Kazuo; Shougase, Takashi; Kawamura, Naoyuki; Tsukamoto, Eriko; Nakada, Kunihiro; Sakuma, Makoto; Furudate, Masayori

    1987-10-01

    A quantitative assessment of limb blood flow using a non-diffusible radioindicator, Tc-99m labeled red blood cells, was reported. This was an application of venous occlusion plethysmography using radionuclide which was originally proposed by M. Fukuoka et al. The peripheral blood flow (mean +- s.e.) of 30 legs in a normal control group was 1.87 +- 0.08 ml/100 ml/min. In heart diseases (46 legs), it was 1.49 +- 0.13 ml/100 ml/min. The limb blood flow between a control group and heart diseases was statistically significant (p < 0.01) in the t-test. The peripheral blood flow at rest between diseased legs and normal legs in occlusive arterial disorders was also statistically significant (p < 0.01) in a paired t-test. RAVOP was done after the completion of objective studies such as radionuclide angiography or ventriculography. Technique and calculation of a blood flow were very easy and simple. RAVOP study which was originally proposed by Fukuoka et al. was reappraised to be hopeful for quantitative measurement of limb blood flow as a non-invasive technique using Tc-99m labeled red blood cells.

  16. Preliminary quantitative assessment of earthquake casualties and damages

    DEFF Research Database (Denmark)

    Badal, J.; Vázquez-Prada, M.; González, Á.

    2005-01-01

    Prognostic estimations of the expected number of killed or injured people and about the approximate cost associated with the damages caused by earthquakes are made following a suitable methodology of wide-ranging application. For the preliminary assessment of human life losses due to the occurrence...... of a relatively strong earthquake we use a quantitative model consisting of a correlation between the number of casualties and the earthquake magnitude as a function of population density. The macroseismic intensity field is determined in accordance with an updated anelastic attenuation law, and the number...... the local social wealth as a function of the gross domestic product of the country. This last step is performed on the basis of the relationship of the macroseismic intensity to the earthquake economic loss in percentage of the wealth. Such an approach to the human casualty and damage levels is carried out...

  17. Assessing the Reliability of Quantitative Imaging of Sm-153

    Science.gov (United States)

    Poh, Zijie; Dagan, Maáyan; Veldman, Jeanette; Trees, Brad

    2013-03-01

    Samarium-153 is used for palliation of and recently has been investigated for therapy for bone metastases. Patient specific dosing of Sm-153 is based on quantitative single-photon emission computed tomography (SPECT) and knowing the accuracy and precision of image-based estimates of the in vivo activity distribution. Physical phantom studies are useful for estimating these in simple objects, but do not model realistic activity distributions. We are using realistic Monte Carlo simulations combined with a realistic digital phantom modeling human anatomy to assess the accuracy and precision of Sm-153 SPECT. Preliminary data indicates that we can simulate projection images and reconstruct them with compensation for various physical image degrading factors, such as attenuation and scatter in the body as well as non-idealities in the imaging system, to provide realistic SPECT images.

  18. Quantitative assessment of bone scintigraphy in the hip joint disease

    Energy Technology Data Exchange (ETDEWEB)

    Hasegawa, Yukiharu

    1985-05-01

    Quantitative assessment of bone scintigraphy was performed in fifty-six patients with hip joint disease including femoral neck fracture, aseptic necrosis of the femoral head, traumatic dislocation of the hip, Perthes disease, and transient synovitis of the hip. In the static study, bone scintigraphy was obtained 3 hours after injection of sup(99m)Tc-MDP by gamma camera equipped with a computer and uptake ratios were calculated. In the dynamic study, bone scintigraphy was performed in one, 3 and 5 hours after injection of radionuclide. Femoral head uptake ratio was markedly decreased in osteonecrosis following femoral neck fracture and characteristically increased in aseptic necrosis of the femoral head but prolonged retention of sup(99m)Tc-MDP could be observed. Uptake ratios of epiphysis were decreased in Perthes disease but normal in transient synovitis of the hip. Static and dynamic study of bone scintigraphy may be useful for early diagnosis and treatment in the hip joint disease. (author).

  19. Quantitative assessment of bone scintigraphy in the hip joint disease

    International Nuclear Information System (INIS)

    Hasegawa, Yukiharu

    1985-01-01

    Quantitative assessment of bone scintigraphy was performed in fifty-six patients with hip joint disease including femoral neck fracture, aseptic necrosis of the femoral head, traumatic dislocation of the hip, Perthes disease, and transient synovitis of the hip. In the static study, bone scintigraphy was obtained 3 hours after injection of sup(99m)Tc-MDP by gamma camera equipped with a computer and uptake ratios were calculated. In the dynamic study, bone scintigraphy was performed in one, 3 and 5 hours after injection of radionuclide. Femoral head uptake ratio was markedly decreased in osteonecrosis following femoral neck fracture and characteristically increased in aseptic necrosis of the femoral head but prolonged retention of sup(99m)Tc-MDP could be observed. Uptake ratios of epiphysis were decreased in Perthes disease but normal in transient synovitis of the hip. Static and dynamic study of bone scintigraphy may be useful for early diagnosis and treatment in the hip joint disease. (author)

  20. Comparison of Subjective Assessment and Precise Quantitative Assessment of Lesion Distribution in Diabetic Retinopathy.

    Science.gov (United States)

    Sears, Connie Martin; Nittala, Muneeswar G; Jayadev, Chaitra; Verhoek, Michael; Fleming, Alan; van Hemert, Jano; Tsui, Irena; Sadda, SriniVas R

    2018-02-22

    Predominantly peripheral disease in eyes with nonproliferative diabetic retinopathy (DR) is suggested as a potential strong risk factor for progression to proliferative disease. However, the reliability and optimal method for the assessment of lesion distribution are still uncertain. To compare agreement between subjective assessment and precise quantification of lesion burden in ultrawidefield (UWF) images of eyes with DR. This multisite cross-sectional study examines UWF pseudocolor images acquired from DR screening clinic patients from December 20, 2014, through August 1, 2014. Of 104 cases, 161 eyes with DR were included. Data analysis was conducted from June 1, 2016, through December 1, 2016 at the Doheny Image Reading Center. Distribution of DR lesions in eyes was assessed subjectively and quantitatively, and eyes were classified as having predominantly central lesions (PCLs) or predominantly peripheral lesions (PPLs). The frequency and surface area (SA) of each lesion type were quantified. Intergrader and subjective vs quantitative classification were compared for level of agreement. Several methods of determining PPL distribution were also compared. On subjective frequency-based evaluation by graders, 133 eyes were classified as having PCL, and 28 eyes as having PPL. On exact quantification of lesion SA, 121 eyes were classified as PCL, and 40 eyes as having PPL. On SA-based quantification, 134 eyes were classified as having PCL, and 27 eyes as having PPL. There was a significant difference between qualitative and quantitative classification of DR lesion distribution for both frequency-based (mean difference [SD]: PCL, 6 [2]; PPL, 13 [6]; P difference [SD]: PCL, 6 [1]; PPL, 20 [7]; P quantitative agreement were higher with frequency-based classification. Subjective assessment of PPL DR lesions on UWF images differed in some cases from precise quantitative assessments, particularly when considering the area of lesions. These findings highlight the

  1. Intravenous volume tomographic pulmonary angiography imaging

    Science.gov (United States)

    Ning, Ruola; Strang, John G.; Chen, Biao; Conover, David L.; Yu, Rongfeng

    1999-05-01

    This study presents a new intravenous (IV) tomographic angiography imaging technique, called intravenous volume tomographic digital angiography (VTDA) for cross sectional pulmonary angiography. While the advantages of IV-VTDA over spiral CT in terms of volume scanning time and resolution have been validated and reported in our previous papers for head and neck vascular imaging, the superiority of IV-VTDA over spiral CT for cross sectional pulmonary angiography has not been explored yet. The purpose of this study is to demonstrate the advantage of isotropic resolution of IV-VTDA in the x, y and z directions through phantom and animal studies, and to explore its clinical application for detecting clots in pulmonary angiography. A prototype image intensifier-based VTDA imaging system has been designed and constructed by modifying a GE 8800 CT scanner. This system was used for a series of phantom and dog studies. A pulmonary vascular phantom was designed and constructed. The phantom was scanned using the prototype VTDA system for direct 3D reconstruction. Then the same phantom was scanned using a GE CT/i spiral CT scanner using the routine pulmonary CT angiography protocols. IV contrast injection and volume scanning protocols were developed during the dog studies. Both VTDA reconstructed images and spiral CT images of the specially designed phantom were analyzed and compared. The detectability of simulated vessels and clots was assessed as the function of iodine concentration levels, oriented angles, and diameters of the vessels and clots. A set of 3D VTDA reconstruction images of dog pulmonary arteries was obtained with different IV injection rates and isotropic resolution in the x, y and z directions. The results of clot detection studies in dog pulmonary arteries have also been shown. This study presents a new tomographic IV angiography imaging technique for cross sectional pulmonary angiography. The results of phantom and animal studies indicate that IV-VTDA is

  2. Thermography as a quantitative imaging method for assessing postoperative inflammation

    Science.gov (United States)

    Christensen, J; Matzen, LH; Vaeth, M; Schou, S; Wenzel, A

    2012-01-01

    Objective To assess differences in skin temperature between the operated and control side of the face after mandibular third molar surgery using thermography. Methods 127 patients had 1 mandibular third molar removed. Before the surgery, standardized thermograms were taken of both sides of the patient's face using a Flir ThermaCam™ E320 (Precisions Teknik AB, Halmstad, Sweden). The imaging procedure was repeated 2 days and 7 days after surgery. A region of interest including the third molar region was marked on each image. The mean temperature within each region of interest was calculated. The difference between sides and over time were assessed using paired t-tests. Results No significant difference was found between the operated side and the control side either before or 7 days after surgery (p > 0.3). The temperature of the operated side (mean: 32.39 °C, range: 28.9–35.3 °C) was higher than that of the control side (mean: 32.06 °C, range: 28.5–35.0 °C) 2 days after surgery [0.33 °C, 95% confidence interval (CI): 0.22–0.44 °C, p 0.1). After 2 days, the operated side was not significantly different from the temperature pre-operatively (p = 0.12), whereas the control side had a lower temperature (0.57 °C, 95% CI: 0.29–0.86 °C, p Thermography seems useful for quantitative assessment of inflammation between the intervention side and the control side after surgical removal of mandibular third molars. However, thermography cannot be used to assess absolute temperature changes due to normal variations in skin temperature over time. PMID:22752326

  3. Quantitative assessment of time trends: influence of time window selection

    International Nuclear Information System (INIS)

    Prosek, A.; Mavko, B.

    2004-01-01

    Quantitative assessment of thermalhydraulic system code predictions is today indispensable for code verification and validation. It is also needed for standard nuclear power plant nodalization development and qualification. Initially the Fast Fourier Transform Based Method (FFTBM) was proposed for accuracy quantification. Later a few new methods were proposed like Automated Code Assessment Program (ACAP) and Stochastic Approximation Ratio Based Method (SARBM). Recently, the review of FFTBM applications was done and reference FFTBM database was proposed consisting of most accurate international standard problems, standard problem exercises or organization calculations as judged by FFTBM. The calculations were presented by primary pressure average amplitude and total accuracy for the whole transient duration. The objective of this study was to investigate how the time window selection influences on the results. For the quantitative assessment various BETHSY experiments and Mochovce plant transient were selected and calculations obtained by RELAP5/MOD3.2 and RELAP5/MOD3.2.2 code, respectively. In the accuracy analysis each transient is subdivided into phases that define the time window and time interval. The time window is time duration of phase. The time interval is time window from the start time of first phase to the end time of selected phase. The analysis was performed for moving time window (sequence of narrow time windows) and increasing time interval (sequence of time intervals). The results for moving time window showed that accuracy measures were very time dependent and they efficiently showed the instantaneous discrepancies occurring in the calculated signal. They also give picture how complex is the transient. The average amplitude (AA) was compared with relative error function (the difference between calculated and measured signal divided by measured signal) and SARBM results. The trends for accuracy measures were similar. These results suggest that for

  4. Quantitative Assessment of Left Ventricular Function and Myocardial Mass: A Comparison of Coronary CT Angiography with Cardiac MRI and Echocardiography

    International Nuclear Information System (INIS)

    Kara, Bedia; Nayman, Alaaddin; Guler, Ibrahim; Gul, Enes Elvin; Koplay, Mustafa; Paksoy, Yahya

    2016-01-01

    The purpose of this study was to compare the left ventricular parameters obtained from multi-detector row computed tomography (MDCT) studies with two-dimensional echocardiography (2DE), and magnetic resonance imaging (MRI), which is accepted as the gold standard in the evaluation of left ventricular functions. The study also aimed to evaluate whether or not there is a relationship between the MR-Argus and CMR tools software programs which are used in post-process calculations of data obtained by MRI. Forty patients with an average age of 51.4±14.9 years who had been scanned with cardiac MDCT were evaluated with cardiac MRI and 2DE. End-diastolic volume (EDV), end-systolic volume (ESV), stroke volume (SV), ejection fraction (EF), cardiac output (CO), and myocardial mass values calculated by MDCT, MRI, and 2DE were compared with each other. Two different MR software programs were used to compare left ventricular functions. The CMR tools LV tutorials method is accepted as the gold standard because it can be used in three-dimensional functional evaluation. The Pearson Correlation and Bland-Altman analysis were performed to compare the results from the two MR methods (MR-Argus and CMR tools) and the results from both the MDCT and the 2DE with the CMR tools results. Strong positive correlations for EF values were found between the MDCT and CMR tools (r=0.702 p<0.001), and between the MR-Argus and CMR tools (r=0.746 p<0.001). The correlation between the 2DE and CMR tools (r=0.449 p<0.004), however, was only moderate. Similar results were obtained for the other parameters. The strongest correlation for ESV, EDV, and EF was between the two MR software programs. The correlation coefficient between the MDCT and CMR tools is close to the correlation coefficient between the two software programs. While the correlation between 2DE and CMR tools was satisfactory for ESV, EDV, and CO values, it was at a moderate level for the other parameters. Left ventricular functional analysis can be performed easily and reliably with cardiac MDCT used for coronary artery evaluation and it also gives more accurate results than 2DE

  5. Computational technique for stepwise quantitative assessment of equation correctness

    Science.gov (United States)

    Othman, Nuru'l Izzah; Bakar, Zainab Abu

    2017-04-01

    Many of the computer-aided mathematics assessment systems that are available today possess the capability to implement stepwise correctness checking of a working scheme for solving equations. The computational technique for assessing the correctness of each response in the scheme mainly involves checking the mathematical equivalence and providing qualitative feedback. This paper presents a technique, known as the Stepwise Correctness Checking and Scoring (SCCS) technique that checks the correctness of each equation in terms of structural equivalence and provides quantitative feedback. The technique, which is based on the Multiset framework, adapts certain techniques from textual information retrieval involving tokenization, document modelling and similarity evaluation. The performance of the SCCS technique was tested using worked solutions on solving linear algebraic equations in one variable. 350 working schemes comprising of 1385 responses were collected using a marking engine prototype, which has been developed based on the technique. The results show that both the automated analytical scores and the automated overall scores generated by the marking engine exhibit high percent agreement, high correlation and high degree of agreement with manual scores with small average absolute and mixed errors.

  6. A quantitative method for assessing resilience of interdependent infrastructures

    International Nuclear Information System (INIS)

    Nan, Cen; Sansavini, Giovanni

    2017-01-01

    The importance of understanding system resilience and identifying ways to enhance it, especially for interdependent infrastructures our daily life depends on, has been recognized not only by academics, but also by the corporate and public sectors. During recent years, several methods and frameworks have been proposed and developed to explore applicable techniques to assess and analyze system resilience in a comprehensive way. However, they are often tailored to specific disruptive hazards/events, or fail to properly include all the phases such as absorption, adaptation, and recovery. In this paper, a quantitative method for the assessment of the system resilience is proposed. The method consists of two components: an integrated metric for system resilience quantification and a hybrid modeling approach for representing the failure behavior of infrastructure systems. The feasibility and applicability of the proposed method are tested using an electric power supply system as the exemplary infrastructure. Simulation results highlight that the method proves effective in designing, engineering and improving the resilience of infrastructures. Finally, system resilience is proposed as a proxy to quantify the coupling strength between interdependent infrastructures. - Highlights: • A method for quantifying resilience of interdependent infrastructures is proposed. • It combines multi-layer hybrid modeling and a time-dependent resilience metric. • The feasibility of the proposed method is tested on the electric power supply system. • The method provides insights to decision-makers for strengthening system resilience. • Resilience capabilities can be used to engineer interdependencies between subsystems.

  7. Assessing quantitative EEG spectrograms to identify non-epileptic events.

    Science.gov (United States)

    Goenka, Ajay; Boro, Alexis; Yozawitz, Elissa

    2017-09-01

    To evaluate the sensitivity and specificity of quantitative EEG (QEEG) spectrograms in order to distinguish epileptic from non-epileptic events. Seventeen patients with paroxysmal non-epileptic events, captured during EEG monitoring, were retrospectively assessed using QEEG spectrograms. These patients were compared to a control group of 13 consecutive patients (ages 25-60 years) with epileptic seizures of similar semiology. Assessment of raw EEG was employed as the gold standard against which epileptic and non-epileptic events were validated. QEEG spectrograms, available using Persyst 12 EEG system integration software, were each assessed with respect to their usefulness to distinguish epileptic from non-epileptic seizures. The given spectrogram was interpreted as indicating a seizure if, at the time of the clinically identified event, it showed a visually significant change from baseline. Eighty-two clinically identified paroxysmal events were analysed (46 non-epileptic and 36 epileptic). The "seizure detector trend analysis" spectrogram correctly classified 33/46 (71%) non-epileptic events (no seizure indicated during a clinically identified event) vs. 29/36 (81%) epileptic seizures (seizure indicated during a clinically identified event) (p=0.013). Similarly, "rhythmicity spectrogram", FFT spectrogram, "asymmetry relative spectrogram", and integrated-amplitude EEG spectrogram detected 28/46 (61%), 30/46 (65%), 22/46 (48%) and 27/46 (59%) non-epileptic events vs. 27/36 (75%), 25/36 (69%), 25/36 (69%) and 27/36 (75%) epileptic events, respectively. High sensitivities and specificities for QEEG seizure detection analyses suggest that QEEG may have a role at the bedside to facilitate early differentiation between epileptic seizures and non-epileptic events in order to avoid unnecessary administration of antiepileptic drugs and possible iatrogenic consequences.

  8. Approaches to quantitative risk assessment with applications to PP

    International Nuclear Information System (INIS)

    Geiger, G.; Schaefer, A.

    2002-01-01

    Full text: Experience with accidents such as Goiania in Brazil and indications of a considerable number of orphan sources suggest that improved protection would be desirable for some types of radioactive material of wide-spread use such as radiation sources for civil purposes. Regarding large potential health and economic consequences (in particular, if terrorists attacks cannot be excluded), significant costs of preventive actions, and large uncertainties about both the likelihood of occurrence and the potential consequences of PP safety and security incidents, an optimum relationship between preventive and mitigative efforts is likely to be a key issue for successful risk management in this field. Thus, possible violations of physical protection combined with threats of misuse of nuclear materials, including terrorist attack, pose considerable challenges to global security from various perspectives. In view of these challenges, recent advance in applied risk and decision analysis suggests methodological and procedural improvements in quantitative risk assessment, the demarcation of acceptable risk, and risk management. Advance is based on a recently developed model of optimal risky choice suitable for assessing and comparing the cumulative probability distribution functions attached to safety and security risks. Besides quantification of risk (e. g., in economic terms), the standardization of various risk assessment models frequently used in operations research can be approached on this basis. The paper explores possible applications of these improved methods to the safety and security management of nuclear materials, cost efficiency of risk management measures, and the establishment international safety and security standards of PP. Examples will be presented that are based on selected scenarios of misuse involving typical radioactive sources. (author)

  9. Assessment of chronic thromboembolic pulmonary hypertension by three-dimensional contrast-enhanced MR angiography - comparison with selective intraarterial DSA

    International Nuclear Information System (INIS)

    Kreitner, K.F.; Ley, S.; Kauczor, H.U.; Kalden, P.; Pitton, M.B.; Thelen, M.; Mayer, E.; Laub, G.

    2000-01-01

    Purpose: This study compares contrast-enhanced 3D-MR angiography (MRA) of the pulmonary arteries with selective intraarterial DSA in patients with chronic thromboembolic pulmonary hypertension. Materials and methods: 20 patients preoperatively underwent a contrast-enhanced 3D-MRA of the pulmonary arteries at 1.5 T using the phased-array body coil. For MRA, we used a 3D-Flash-sequence after bolus timing. 2 radiologists analyzed the acquired image material in consensus with respect to the detection of central thromboembolic material and the visualization of the pulmonary arterial tree. Finally, the MR angiograms were compared with selective DSA images using surgical findings as the definitive standard. Results: MRA demonstrated central thromboembolic material, vessel cut-offs and abnormal proximal-to-distal tapering in all patients. Compared to DSA, MRA depicted the pulmonary vessels up to the segmental level in all cases, it was inferior to DSA in delineation of the subsegmental arteries (sensitivity 87%, specificity 100%). The central beginning of the thromboembolic occlusions seen at MRA corresponded to the beginning of the deobliteration procedure during pulmonary thromboendarterectomy in every case. (orig.) [de

  10. Time-resolved assessment of collateral flow using 4D CT angiography in large-vessel occlusion stroke

    International Nuclear Information System (INIS)

    Froelich, Andreas M.J.; Wolff, Sarah Lena; Psychogios, Marios N.; Schramm, Ramona; Knauth, Michael; Schramm, Peter; Klotz, Ernst; Wasser, Katrin

    2014-01-01

    In acute stroke patients with large vessel occlusion, collateral blood flow affects tissue fate and patient outcome. The visibility of collaterals on computed tomography angiography (CTA) strongly depends on the acquisition phase, but the optimal time point for collateral imaging is unknown. We analysed collaterals in a time-resolved fashion using four-dimensional (4D) CTA in 82 endovascularly treated stroke patients, aiming to determine which acquisition phase best depicts collaterals and predicts outcome. Early, peak and late phases as well as temporally fused maximum intensity projections (tMIP) were graded using a semiquantitative regional leptomeningeal collateral score, compared with conventional single-phase CTA and correlated with functional outcome. The total extent of collateral flow was best visualised on tMIP. Collateral scores were significantly lower on early and peak phase as well as on single-phase CTA. Collateral grade was associated with favourable functional outcome and the strength of this relationship increased from earlier to later phases, with collaterals on tMIP showing the strongest correlation with outcome. Temporally fused tMIP images provide the best depiction of collateral flow. Our findings suggest that the total extent of collateral flow, rather than the velocity of collateral filling, best predicts clinical outcome. (orig.)

  11. Assessment of Myocardial Bridge and Mural Coronary Artery Using ECG-Gated 256-Slice CT Angiography: A Retrospective Study

    Directory of Open Access Journals (Sweden)

    En-sen Ma

    2013-01-01

    Full Text Available Recent clinical reports have indicated that myocardial bridge and mural coronary artery complex (MB-MCA might cause major adverse cardiac events. 256-slice CT angiography (256-slice CTA is a newly developed CT system with faster scanning and lower radiation dose compared with other CT systems. The objective of this study is to evaluate the morphological features of MB-MCA and determine its changes from diastole to systole phase using 256-slice CTA. The imaging data of 2462 patients were collected retrospectively. Two independent radiologists reviewed the collected images and the diagnosis of MB-MCA was confirmed when consistency was obtained. The length, diameter, and thickness of MB-MCA in diastole and systole phases were recorded, and changes of MB-MCA were calculated. Our results showed that among the 2462 patients examined, 336 have one or multiple MB-MCA (13.6%. Out of 389 MB-MCA segments, 235 sites were located in LAD2 (60.41%. The average diameter change of MCA in LAD2 from systole phase to diastole phase was  mm, and 34.9% of MCA have more than 50% diameter stenosis in systole phase. This study suggested that 256-slice CTA multiple-phase reconstruction technique is a reliable method to determine the changes of MB-MCA from diastole to systole phase.

  12. Readability of Wikipedia Pages on Autoimmune Disorders: Systematic Quantitative Assessment

    Science.gov (United States)

    Bragazzi, Nicola Luigi; Brigo, Francesco; Sharif, Kassem; Amital, Howard; McGonagle, Dennis; Shoenfeld, Yehuda; Adawi, Mohammad

    2017-01-01

    Background In the era of new information and communication technologies, the Internet is being increasingly accessed for health-related information. Indeed, recently published patient surveys of people with autoimmune disorders confirmed that the Internet was reported as one of the most important health information sources. Wikipedia, a free online encyclopedia launched in 2001, is generally one of the most visited websites worldwide and is often consulted for health-related information. Objective The main objective of this investigation was to quantitatively assess whether the Wikipedia pages related to autoimmune disorders can be easily accessed by patients and their families, in terms of readability. Methods We obtained and downloaded a list of autoimmune disorders from the American Autoimmune Related Diseases Association (AARDA) website. We analyzed Wikipedia articles for their overall level of readability with 6 different quantitative readability scales: (1) the Flesch Reading Ease, (2) the Gunning Fog Index, (3) the Coleman-Liau Index, (4) the Flesch-Kincaid Grade Level, (5) the Automated Readability Index (ARI), and (6) the Simple Measure of Gobbledygook (SMOG). Further, we investigated the correlation between readability and clinical, pathological, and epidemiological parameters. Moreover, each Wikipedia analysis was assessed according to its content, breaking down the readability indices by main topic of each part (namely, pathogenesis, treatment, diagnosis, and prognosis plus a section containing paragraphs not falling into any of the previous categories). Results We retrieved 134 diseases from the AARDA website. The Flesch Reading Ease yielded a mean score of 24.34 (SD 10.73), indicating that the sites were very difficult to read and best understood by university graduates, while mean Gunning Fog Index and ARI scores were 16.87 (SD 2.03) and 14.06 (SD 2.12), respectively. The Coleman-Liau Index and the Flesch-Kincaid Grade Level yielded mean scores of 14

  13. Quantitative assessment of periimplant bone density (HU) on CBCT image

    International Nuclear Information System (INIS)

    Goo, Jong Gook; Kim, Jin Soo; Kim, Jae Duk

    2008-01-01

    The primary aims of this retrospective study were to compare subjective bone quality and bone quality based on the Hounsfield scale in different segments of the edentulous jaw, and to establish quantitative and objective assessment of the bone quality. Twenty eight randomly selected cone-beam computed tomographic (CBCT) scans were analyzed. For evaluation one hundred and twelve edentulous areas were selected. Implant recipient sites were evaluated visually for Lekholm and Zarb classification. The same sites were subsequently evaluated digitally using the Hounsfield scale with Vimplant 2.0 TM , and the results were correlated with visual classification. Data was subject for statistical analysis in order to determine correlation between recorded HU and the regions of the mouth with the Kruskal-Wallis test. The highest unit/mean density value (311 HU) was found in the anterior mandible, followed by 259 HU for the posterior mandible, 216 HU for the anterior maxilla, and 127 HU for the posterior maxilla. These results demonstrate a strong correlation for HU depending on the region of the mouth (p TM with Vimplant TM software.

  14. Quantitative assessment in thermal image segmentation for artistic objects

    Science.gov (United States)

    Yousefi, Bardia; Sfarra, Stefano; Maldague, Xavier P. V.

    2017-07-01

    The application of the thermal and infrared technology in different areas of research is considerably increasing. These applications involve Non-destructive Testing (NDT), Medical analysis (Computer Aid Diagnosis/Detection- CAD), Arts and Archaeology among many others. In the arts and archaeology field, infrared technology provides significant contributions in term of finding defects of possible impaired regions. This has been done through a wide range of different thermographic experiments and infrared methods. The proposed approach here focuses on application of some known factor analysis methods such as standard Non-Negative Matrix Factorization (NMF) optimized by gradient-descent-based multiplicative rules (SNMF1) and standard NMF optimized by Non-negative least squares (NNLS) active-set algorithm (SNMF2) and eigen decomposition approaches such as Principal Component Thermography (PCT), Candid Covariance-Free Incremental Principal Component Thermography (CCIPCT) to obtain the thermal features. On one hand, these methods are usually applied as preprocessing before clustering for the purpose of segmentation of possible defects. On the other hand, a wavelet based data fusion combines the data of each method with PCT to increase the accuracy of the algorithm. The quantitative assessment of these approaches indicates considerable segmentation along with the reasonable computational complexity. It shows the promising performance and demonstrated a confirmation for the outlined properties. In particular, a polychromatic wooden statue and a fresco were analyzed using the above mentioned methods and interesting results were obtained.

  15. Arterial anomalies of the celiac trunk and median arcuate ligament compression in dogs and cats assessed by computed tomography angiography.

    Science.gov (United States)

    Le Pommellet, Hélène M; Scansen, Brian A; Mathys, Dimitria A; Mollenkopf, Dixie F; Reeves, Lauren; Skinas, Melissa L; Patel, Mira

    2018-02-01

    To identify abnormalities of the celiac artery (CA) and major branches in dogs and cats by computed tomography angiography (CTA). Multi-institutional retrospective case series. Two hundred fifty-four dogs and 13 cats. Abdominal CTA images from 2009 to 2017 were reviewed. Logistic regression models were used to evaluate the relationship between CA abnormalities and sex, age, size of dog, concurrent venous anomaly, or presence of gastrointestinal signs. Abnormalities in the CA were observed in 32 animals (11.9%) including 9 with abnormal branching (3.4%) and 23 with CA compression (8.6%). A celiacomesenteric trunk was observed in 8 (2.9%; 6 dogs, 2 cats). The splenic artery originated from the cranial mesenteric artery in 1 dog; the hepatic arterial branches originated from the left gastric artery in another. Four out of 32 animals (12.5%) with an arterial anomaly had another vascular abnormality. Large breed dogs were more likely to have an arterial anomaly (OR 4.3, 95% CI: 1.18-15.5, P = .02) and 12 times more likely to have CA compression (OR 12.0, 95% CI: 1.4-97.7, P = .02) compared to small breed dogs. Dogs with CA compression were more likely to present for gastrointestinal signs (OR 3.6, 95% CI: 1.2-10.3, P = .01). Anomalies of the celiac trunk are apparent on CTA and may impact surgical or image-guided intervention. Compression at the origin of the CA was apparent on imaging, similar to the median arcuate ligament syndrome in people, although the significance of this finding in dogs is unknown. © 2017 The American College of Veterinary Surgeons.

  16. MR angiography in pediatric neurological disorders

    International Nuclear Information System (INIS)

    Lee, B.C.P.; Park, T.S.; Kaufman, B.A.

    1995-01-01

    MR angiography using 3D and 2D time-of-flight techniques were used to evaluate pediatric neurological disorders. MRA (arteriography) and MRV (venography) were abnormal in 63 and 45 cases, respectively. Conventional cerebral angiography was performed in 30 cases. These techniques were compared with MRI and conventional angiography. In addition, the value of MR angiography for surgical planning was subjectively evaluated. Our results showed that intracranial vessels were invariably better shown on MR angiography than on MRI. MRA and MRV were most useful in evaluating vascular distortions related to congenital brain malformations and intracranial tumors. MRA was valuable in detecting arterial narrowing but overestimated the degree of stenosis compared with conventional angiography. MRV was the technique of choice for evaluation of dural sinus and cerebral venous thrombosis and compression. MRA played little to no role in preoperative planning of vascular malformations and aneurysms. It did not appear to be accurate in assessing tumor vascularity or lesions in small arteries and arteritis. (orig.)

  17. COMPARING FUNDUS FLUORESCEIN ANGIOGRAPHY AND SWEPT-SOURCE OPTICAL COHERENCE TOMOGRAPHY ANGIOGRAPHY IN THE EVALUATION OF DIABETIC MACULAR PERFUSION.

    Science.gov (United States)

    La Mantia, Alberto; Kurt, Rengin A; Mejor, Samantha; Egan, Catherine A; Tufail, Adnan; Keane, Pearse A; Sim, Dawn A

    2018-01-16

    To compare fundus fluorescein angiography (FFA) and swept-source optical coherence tomography angiography (SS-OCTA) in the evaluation of macular perfusion in diabetic patients. Forty-one eyes (21 diabetic patients) seen at Moorfields Eye Hospital (London) over a 1-month interval underwent color fundus photography, FFA, and SS-OCTA imaging of the capillary superficial plexus using 2 different protocols: 3 × 3 mm and 4.5 × 4.5 mm. Quantitative assessment (foveal avascular zone diameters and area), qualitative analysis (macroscopic and microscopic levels) and Early Treatment Diabetic Retinopathy Study diabetic macular ischemia grading were performed. Artifacts were recorded. Intraclass correlation coefficients and weighted kappa values were calculated. Mean (SD) foveal avascular zone area was 0.695 (0.52) mm on FFA, 0.627 (0.54) mm on SS-OCTA 3 × 3 and 0.701 (0.54) mm on SS-OCTA 4.5 × 4.5 protocol. Intraclass correlation coefficients showed good agreement between FFA and SS-OCTA for both vertical diameter and foveal avascular zone area measurements. The agreement between SS-OCTA 3 × 3 and 4.5 × 4.5 was good for all quantitative measurements. Weighted kappa for diabetic macular ischemia grading showed low to fair agreement between FFA and SS-OCTA, whereas the agreement was good between two different SS-OCTA protocols. Swept-source OCTA is a reproducible technique in the assessment of macular perfusion in diabetic patients with special regards to foveal avascular zone analysis. The agreement with FFA is limited especially for diabetic macular ischemia grading. Fundus fluorescein angiography is more sensitive in identifying microaneurysms.

  18. MR angiography as a screening tool for intracranial aneurysms: feasibility, test characteristics, and interobserver agreement

    NARCIS (Netherlands)

    Raaymakers, T. W.; Buys, P. C.; Verbeeten, B.; Ramos, L. M.; Witkamp, T. D.; Hulsmans, F. J.; Mali, W. P.; Algra, A.; Bonsel, G. J.; Bossuyt, P. M.; Vonk, C. M.; Buskens, E.; Limburg, M.; van Gijn, J.; Gorissen, A.; Greebe, P.; Albrecht, K. W.; Tulleken, C. A.; Rinkel, G. J.

    1999-01-01

    OBJECTIVE: MR angiography may be an appropriate tool to screen for unruptured intracranial aneurysms. Feasibility, test characteristics, and interobserver agreement in evaluation of MR angiograms were assessed by members of the MARS (Magnetic resonance Angiography in Relatives of patients with

  19. Quantitative assessment of the effectiveness of a rockfall warning system

    Science.gov (United States)

    Bründl, Michael; Sättele, Martina; Krautblatter, Michael; Straub, Daniel

    2016-04-01

    Rockslides and rockfalls can pose high risk to human settlements and traffic infrastructure. In addition to structural mitigation measures like rockfall nets, warning systems are increasingly installed to reduce rockfall risks. Whereas for structural mitigation measures with reducing effects on the spatial extent a structured evaluation method is existing, no or only few approaches to assess the effectiveness for warning systems are known. Especially for higher magnitude rockfalls structural mitigation measures are not effective, and reliable early warning systems will be essential in future. In response to that, we developed a classification and a framework to assess the reliability and effectiveness of early warning systems (Sättele et al, 2015a; 2016). Here, we demonstrate an application for the rockfall warning system installed in Preonzo prior to a major rockfall in May 2012 (Sättele et al., 2015b). We show that it is necessary to design such a warning system as fail-safe construction, which has to incorporate components with low failure probabilities, high redundancy, low warning thresholds, and additional control systems. With a hypothetical probabilistic analysis, we investigate the effect of the risk attitude of decision makers and of the number of sensors on the probability of detecting an event and on initiating a timely evacuation, as well as on related intervention cost. We conclude that it is possible to quantitatively assess the effectiveness of warning systems, which helps to optimize mitigation strategies against rockfall events. References Sättele, M., Bründl, M., and Straub, D.: Reliability and effectiveness of warning systems for natural hazards: concept and application to debris flow warning, Rel. Eng. Syst. Safety, 142, 192-202, 2015a. Sättele, M., Krautblatter, M., Bründl, M., and Straub, D.: Forecasting rock slope failure: How reliable and effective are warning systems?, Landslides, 605, 1-14, 2015b. Sättele, M., Bründl, M., and

  20. CT angiography after carotid artery stenting: assessment of the utility of adaptive statistical iterative reconstruction and model-based iterative reconstruction

    Energy Technology Data Exchange (ETDEWEB)

    Kuya, Keita; Shinohara, Yuki; Fujii, Shinya; Ogawa, Toshihide [Tottori University, Division of Radiology, Department of Pathophysiological Therapeutic Science, Faculty of Medicine, Yonago (Japan); Sakamoto, Makoto; Watanabe, Takashi [Tottori University, Division of Neurosurgery, Department of Brain and Neurosciences, Faculty of Medicine, Yonago (Japan); Iwata, Naoki; Kishimoto, Junichi [Tottori University, Division of Clinical Radiology Faculty of Medicine, Yonago (Japan); Kaminou, Toshio [Osaka Minami Medical Center, Department of Radiology, Osaka (Japan)

    2014-11-15

    Follow-up CT angiography (CTA) is routinely performed for post-procedure management after carotid artery stenting (CAS). However, the stent lumen tends to be underestimated because of stent artifacts on CTA reconstructed with the filtered back projection (FBP) technique. We assessed the utility of new iterative reconstruction techniques, such as adaptive statistical iterative reconstruction (ASIR) and model-based iterative reconstruction (MBIR), for CTA after CAS in comparison with FBP. In a phantom study, we evaluated the differences among the three reconstruction techniques with regard to the relationship between the stent luminal diameter and the degree of underestimation of stent luminal diameter. In a clinical study, 34 patients who underwent follow-up CTA after CAS were included. We compared the stent luminal diameters among FBP, ASIR, and MBIR, and performed visual assessment of low attenuation area (LAA) in the stent lumen using a three-point scale. In the phantom study, stent luminal diameter was increasingly underestimated as luminal diameter became smaller in all CTA images. Stent luminal diameter was larger with MBIR than with the other reconstruction techniques. Similarly, in the clinical study, stent luminal diameter was larger with MBIR than with the other reconstruction techniques. LAA detectability scores of MBIR were greater than or equal to those of FBP and ASIR in all cases. MBIR improved the accuracy of assessment of stent luminal diameter and LAA detectability in the stent lumen when compared with FBP and ASIR. We conclude that MBIR is a useful reconstruction technique for CTA after CAS. (orig.)

  1. Automated quantification of epicardial adipose tissue (EAT) in coronary CT angiography; comparison with manual assessment and correlation with coronary artery disease.

    Science.gov (United States)

    Mihl, Casper; Loeffen, Daan; Versteylen, Mathijs O; Takx, Richard A P; Nelemans, Patricia J; Nijssen, Estelle C; Vega-Higuera, Fernando; Wildberger, Joachim E; Das, Marco

    2014-01-01

    Epicardial adipose tissue (EAT) is emerging as a risk factor for coronary artery disease (CAD). The aim of this study was to determine the applicability and efficiency of automated EAT quantification. EAT volume was assessed both manually and automatically in 157 patients undergoing coronary CT angiography. Manual assessment consisted of a short-axis-based manual measurement, whereas automated assessment on both contrast and non-contrast-enhanced data sets was achieved through novel prototype software. Duration of both quantification methods was recorded, and EAT volumes were compared with paired samples t test. Correlation of volumes was determined with intraclass correlation coefficient; agreement was tested with Bland-Altman analysis. The association between EAT and CAD was estimated with logistic regression. Automated quantification was significantly less time consuming than automated quantification (17 ± 2 seconds vs 280 ± 78 seconds; P EAT volume differed significantly from automated EAT volume (75 ± 33 cm(³) vs 95 ± 45 cm(³); P EAT volume was positively associated with the presence of CAD. Stronger predictive value for the severity of CAD was achieved through automated quantification on both contrast-enhanced and non-contrast-enhanced data sets. Automated EAT quantification is a quick method to estimate EAT and may serve as a predictor for CAD presence and severity. Copyright © 2014 Society of Cardiovascular Computed Tomography. Published by Elsevier Inc. All rights reserved.

  2. Assessment of myocardial fibrosis and coronary arteries in hypertrophic cardiomyopathy using combined arterial and delayed enhanced CT: comparison with MR and coronary angiography

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Lei; Ma, Xiaohai; Zhang, Chen; Liu, Yi; Zhang, Zhaoqi [Capital Medical University, Department of Radiology, Beijing Anzhen Hospital, Beijing (China); DeLano, Mark C. [Michigan State University, Division of Radiology and Biomedical Imaging, College of Human Medicine, Lancing, MI (United States); Jiang, Tengyong [Capital Medical University, Department of Cardiology, Beijing Anzhen Hospital, Beijing (China)

    2013-04-15

    We sought to determine the feasibility and accuracy of dual-source computed tomography (DSCT) in assessing coronary artery disease and myocardial fibrosis of hypertrophic cardiomyopathy (HCM) compared with cardiac magnetic resonance (CMR) imaging and coronary angiography (CA). Forty-seven consecutive patients with HCM were prospectively enrolled. DSCT images were acquired in the arterial and late phases following intravenous contrast medium. The CMR and CA were performed within 7 days. Independent blinded readers read each study. Patients were classified according to myocardial delayed enhanced (MDE) CMR, coronary artery stenosis by CA, and arterial and MDE-DSCT. The diagnostic accuracy of DSCT in detecting coronary stenosis and MDE was analysed. Wall thickness determined by DSCT was strongly correlated with MR results (r = 0.91). DSCT and CMR MDE showed substantial agreement for the detection of myocardial fibrosis on per-patient and per-segment levels. The CT classification of patients by arterial stenosis and delayed enhancement had excellent agreement with MR and CA methods. The comprehensive cardiac CT examination provides reliable coronary artery and myocardial assessments. MDE-DSCT is a robust alternative method to MDE-CMR in assessing myocardial fibrosis in HCM particularly in patients with pacemakers or other contraindications to CMR. (orig.)

  3. Assessment of pulmonary venous stenosis after radiofrequency catheter ablation for atrial fibrillation by magnetic resonance angiography: a comparison of linear and cross-sectional area measurements

    Energy Technology Data Exchange (ETDEWEB)

    Tintera, Jaroslav; Porod, Vaclav; Rolencova, Eva; Fendrych, Pavel [Institute for Clinical and Experimental Medicine, Department of Radiology, Prague 4 (Czech Republic); Cihak, Robert; Mlcochova, Hanka; Kautzner, Josef [Institute for Clinical and Experimental Medicine, Department of Cardiology, Prague 4 (Czech Republic)

    2006-12-15

    One of the recognised complications of catheter ablation is pulmonary venous stenosis. The aim of this study was to compare two methods of evaluation of pulmonary venous diameter for follow-up assessment of the above complication: (1) a linear approach evaluating two main diameters of the vein, (2) semiautomatically measured cross-sectional area (CSA). The study population consists of 29 patients. All subjects underwent contrast-enhanced magnetic resonance angiography (CeMRA) of the pulmonary veins (PVs) before and after the ablation; 14 patients were also scanned 3 months later. PV diameter was evaluated from two-dimensional multiplanar reconstructions by measuring either the linear diameter or CSA. A comparison between pulmonary venous CSA and linear measurements revealed a systematic difference in absolute values. This difference was not significant when comparing the relative change CSA and quadratic approximation using linear extents (linear approach). However, a trend towards over-estimation of calibre reduction was documented for the linear approach. Using CSA assessment, significant PV stenosis was found in ten PVs (8%) shortly after ablation. Less significant PV stenosis, ranging from 20 to 50% was documented in other 18 PVs (15%). CeMRA with CSA assessment of the PVs is suitable method for evaluation of PV diameters. (orig.)

  4. Assessment of pulmonary venous stenosis after radiofrequency catheter ablation for atrial fibrillation by magnetic resonance angiography: a comparison of linear and cross-sectional area measurements

    International Nuclear Information System (INIS)

    Tintera, Jaroslav; Porod, Vaclav; Rolencova, Eva; Fendrych, Pavel; Cihak, Robert; Mlcochova, Hanka; Kautzner, Josef

    2006-01-01

    One of the recognised complications of catheter ablation is pulmonary venous stenosis. The aim of this study was to compare two methods of evaluation of pulmonary venous diameter for follow-up assessment of the above complication: (1) a linear approach evaluating two main diameters of the vein, (2) semiautomatically measured cross-sectional area (CSA). The study population consists of 29 patients. All subjects underwent contrast-enhanced magnetic resonance angiography (CeMRA) of the pulmonary veins (PVs) before and after the ablation; 14 patients were also scanned 3 months later. PV diameter was evaluated from two-dimensional multiplanar reconstructions by measuring either the linear diameter or CSA. A comparison between pulmonary venous CSA and linear measurements revealed a systematic difference in absolute values. This difference was not significant when comparing the relative change CSA and quadratic approximation using linear extents (linear approach). However, a trend towards over-estimation of calibre reduction was documented for the linear approach. Using CSA assessment, significant PV stenosis was found in ten PVs (8%) shortly after ablation. Less significant PV stenosis, ranging from 20 to 50% was documented in other 18 PVs (15%). CeMRA with CSA assessment of the PVs is suitable method for evaluation of PV diameters. (orig.)

  5. Ankle Brachial Index <0.9 Underestimates the Prevalence of Peripheral Artery Occlusive Disease Assessed with Whole-Body Magnetic Resonance Angiography in the Elderly

    International Nuclear Information System (INIS)

    Wikstroem, J.; Hansen, T.; Johansson, L.; Lind, L.; Ahlstroem, H.

    2008-01-01

    Background: Whole-body magnetic resonance angiography (WBMRA) permits noninvasive vascular assessment, which can be utilized in epidemiological studies. Purpose: To assess the relation between a low ankle brachial index (ABI) and high-grade stenoses in the pelvic and leg arteries in the elderly. Material and Methods: WBMRA was performed in a population sample of 306 subjects aged 70 years. The arteries below the aortic bifurcation were graded after the most severe stenosis according to one of three grades: 0-49% stenosis, 50-99% stenosis, or occlusion. ABI was calculated for each side. Results: There were assessable WBMRA and ABI examinations in 268 (right side), 265 (left side), and 258 cases (both sides). At least one ≥50% stenosis was found in 19% (right side), 23% (left side), and 28% (on at least one side) of the cases. The corresponding prevalences for ABI <0.9 were 4.5%, 4.2%, and 6.6%. An ABI cut-off value of 0.9 resulted in a sensitivity, specificity, and positive and negative predictive value of 20%, 99%, 83%, and 84% on the right side, and 15%, 99%, 82%, and 80% on the left side, respectively, for the presence of a ≥ 50% stenosis in the pelvic or leg arteries. Conclusion: An ABI <0.9 underestimates the prevalence of peripheral arterial occlusive disease in the general elderly population

  6. Optical Coherence Tomography Angiography in Retinal Vascular Diseases and Choroidal Neovascularization

    Directory of Open Access Journals (Sweden)

    Rodolfo Mastropasqua

    2015-01-01

    Full Text Available Purpose. To assess the ability of optical coherence tomography-angiography (OCT-A to show and analyze retinal vascular patterns and the choroidal neovascularization (CNV in retinal vascular diseases. Methods. Seven eyes of seven consecutive patients with retinal vascular diseases were examined. Two healthy subjects served as controls. All eyes were scanned with the SD-OCT XR Avanti (Optovue Inc, Fremont CA, USA. Split spectrum amplitude decorrelation angiography algorithm was used to identify the blood flow within the tissue. Fluorescein angiography (FA and indocyanine green angiography (ICGA with Spectralis HRA + OCT (Heidelberg Engineering GmbH were performed. Results. In healthy subjects OCT-A visualized major macular vessels and detailed capillary networks around the foveal avascular zone. Patients were affected with myopic CNV (2 eyes, age-related macular degeneration related (2, branch retinal vein occlusion (BRVO (2, and branch retinal artery occlusion (BRAO (1. OCT-A images provided distinct vascular patterns, distinguishing perfused and nonperfused areas in BRVO and BRAO and recognizing the presence, location, and size of CNV. Conclusions. OCT-A provides detailed images of retinal vascular plexuses and quantitative data of pathologic structures. Further studies are warranted to define the role of OCT-A in the assessment of retinovascular diseases, with respect to conventional FA and ICG-A.

  7. Quantitative assessment of 201TlCl myocardial SPECT

    International Nuclear Information System (INIS)

    Uehara, Toshiisa

    1987-01-01

    Clinical evaluation of the quantitative analysis of Tl-201 myocardial tomography by SPECT (Single Photon Emission Computed Tomography) was performed in comparison with visual evaluation. The method of quantitative analysis has been already reported in our previous paper. In this study, the program of re-standardization in the case of lateral myocardial infarction was added. This program was useful mainly for the evaluation of lesions in the left circumflex coronary artery. Regarding the degree of diagnostic accuracy of myocardial infarction in general, quantitative evaluation of myocardial SPECT images was highest followed by visual evaluation of myocardial SPECT images, and visual evaluation of myocardial planar images. However, in the case of anterior myocardial infarction, visual evaluation of myocardial SPECT images has almost the same detectability as quantitative evaluation of myocardial SPECT images. In the case of infero-posterior myocardial infarction, quantitative evaluation was superior to visual evaluation. As for specificity, quantitative evaluation of SPECT images was slightly inferior to visual evaluation of SPECT images. An infarction map was made by quantitative analysis and this enabled us to determine the infarction site, extent and degree according to easily recognizable patterns. As a result, the responsible coronary artery lesion could be inferred correctly and the calculated infarction score could be correlated with the residual left ventricular function after myocardial infarction. (author)

  8. Readability of Wikipedia Pages on Autoimmune Disorders: Systematic Quantitative Assessment.

    Science.gov (United States)

    Watad, Abdulla; Bragazzi, Nicola Luigi; Brigo, Francesco; Sharif, Kassem; Amital, Howard; McGonagle, Dennis; Shoenfeld, Yehuda; Adawi, Mohammad

    2017-07-18

    In the era of new information and communication technologies, the Internet is being increasingly accessed for health-related information. Indeed, recently published patient surveys of people with autoimmune disorders confirmed that the Internet was reported as one of the most important health information sources. Wikipedia, a free online encyclopedia launched in 2001, is generally one of the most visited websites worldwide and is often consulted for health-related information. The main objective of this investigation was to quantitatively assess whether the Wikipedia pages related to autoimmune disorders can be easily accessed by patients and their families, in terms of readability. We obtained and downloaded a list of autoimmune disorders from the American Autoimmune Related Diseases Association (AARDA) website. We analyzed Wikipedia articles for their overall level of readability with 6 different quantitative readability scales: (1) the Flesch Reading Ease, (2) the Gunning Fog Index, (3) the Coleman-Liau Index, (4) the Flesch-Kincaid Grade Level, (5) the Automated Readability Index (ARI), and (6) the Simple Measure of Gobbledygook (SMOG). Further, we investigated the correlation between readability and clinical, pathological, and epidemiological parameters. Moreover, each Wikipedia analysis was assessed according to its content, breaking down the readability indices by main topic of each part (namely, pathogenesis, treatment, diagnosis, and prognosis plus a section containing paragraphs not falling into any of the previous categories). We retrieved 134 diseases from the AARDA website. The Flesch Reading Ease yielded a mean score of 24.34 (SD 10.73), indicating that the sites were very difficult to read and best understood by university graduates, while mean Gunning Fog Index and ARI scores were 16.87 (SD 2.03) and 14.06 (SD 2.12), respectively. The Coleman-Liau Index and the Flesch-Kincaid Grade Level yielded mean scores of 14.48 (SD 1.57) and 14.86 (1

  9. Qualitative and quantitative assessment of adenosine triphosphate stress whole-heart dynamic myocardial perfusion imaging using 256-slice computed tomography.

    Science.gov (United States)

    Kurata, Akira; Kawaguchi, Naoto; Kido, Teruhito; Inoue, Katsuji; Suzuki, Jun; Ogimoto, Akiyoshi; Funada, Jun-ichi; Higaki, Jitsuo; Miyagawa, Masao; Vembar, Mani; Mochizuki, Teruhito

    2013-01-01

    The aim of this study was to investigate the correlation of the qualitative transmural extent of hypoperfusion areas (HPA) using stress dynamic whole-heart computed tomography perfusion (CTP) imaging by 256-slice CT with CTP-derived myocardial blood flow (MBF) for the estimation of the severity of coronary artery stenosis. Eleven patients underwent adenosine triphosphate (0.16 mg/kg/min, 5 min) stress dynamic CTP by 256-slice CT (coverage: 8 cm, 0.27 s/rotation), and 9 of the 11 patients underwent coronary angiography (CAG). Stress dynamic CTP (whole-heart datasets over 30 consecutive heart beats in systole without spatial and temporal gaps) was acquired with prospective ECG gating (effective radiation dose: 10.4 mSv). The extent of HPAs was visually graded using a 3-point score (normal, subendocardial, transmural). MBF (ml/100g/min) was measured by deconvolution. Differences in MBF (mean ± standard error) according to HPA and CAG results were evaluated. In 27 regions (3 major coronary territories in 9 patients), 11 coronary stenoses (> 50% reduction in diameter) were observed. In 353 myocardial segments, HPA was significantly related to MBF (P 70%], 119 ± 69). The qualitative transmural extent of HPA using stress whole-heart dynamic CTP imaging by 256-slice CT exhibits a good correlation with quantitative CTP-derived MBF and may aid in assessing the hemodynamic significance of coronary artery disease.

  10. Qualitative and quantitative assessment of adenosine triphosphate stress whole-heart dynamic myocardial perfusion imaging using 256-slice computed tomography.

    Directory of Open Access Journals (Sweden)

    Akira Kurata

    Full Text Available BACKGROUND: The aim of this study was to investigate the correlation of the qualitative transmural extent of hypoperfusion areas (HPA using stress dynamic whole-heart computed tomography perfusion (CTP imaging by 256-slice CT with CTP-derived myocardial blood flow (MBF for the estimation of the severity of coronary artery stenosis. METHODS AND RESULTS: Eleven patients underwent adenosine triphosphate (0.16 mg/kg/min, 5 min stress dynamic CTP by 256-slice CT (coverage: 8 cm, 0.27 s/rotation, and 9 of the 11 patients underwent coronary angiography (CAG. Stress dynamic CTP (whole-heart datasets over 30 consecutive heart beats in systole without spatial and temporal gaps was acquired with prospective ECG gating (effective radiation dose: 10.4 mSv. The extent of HPAs was visually graded using a 3-point score (normal, subendocardial, transmural. MBF (ml/100g/min was measured by deconvolution. Differences in MBF (mean ± standard error according to HPA and CAG results were evaluated. In 27 regions (3 major coronary territories in 9 patients, 11 coronary stenoses (> 50% reduction in diameter were observed. In 353 myocardial segments, HPA was significantly related to MBF (P 70%], 119 ± 69. CONCLUSION: The qualitative transmural extent of HPA using stress whole-heart dynamic CTP imaging by 256-slice CT exhibits a good correlation with quantitative CTP-derived MBF and may aid in assessing the hemodynamic significance of coronary artery disease.

  11. A quantitative assessment method for Ascaris eggs on hands.

    Science.gov (United States)

    Jeandron, Aurelie; Ensink, Jeroen H J; Thamsborg, Stig M; Dalsgaard, Anders; Sengupta, Mita E

    2014-01-01

    The importance of hands in the transmission of soil transmitted helminths, especially Ascaris and Trichuris infections, is under-researched. This is partly because of the absence of a reliable method to quantify the number of eggs on hands. Therefore, the aim of this study was to develop a method to assess the number of Ascaris eggs on hands and determine the egg recovery rate of the method. Under laboratory conditions, hands were seeded with a known number of Ascaris eggs, air dried and washed in a plastic bag retaining the washing water, in order to determine recovery rates of eggs for four different detergents (cationic [benzethonium chloride 0.1% and cetylpyridinium chloride CPC 0.1%], anionic [7X 1% - quadrafos, glycol ether, and dioctyl sulfoccinate sodium salt] and non-ionic [Tween80 0.1% -polyethylene glycol sorbitan monooleate]) and two egg detection methods (McMaster technique and FLOTAC). A modified concentration McMaster technique showed the highest egg recovery rate from bags. Two of the four diluted detergents (benzethonium chloride 0.1% and 7X 1%) also showed a higher egg recovery rate and were then compared with de-ionized water for recovery of helminth eggs from hands. The highest recovery rate (95.6%) was achieved with a hand rinse performed with 7X 1%. Washing hands with de-ionized water resulted in an egg recovery rate of 82.7%. This washing method performed with a low concentration of detergent offers potential for quantitative investigation of contamination of hands with Ascaris eggs and of their role in human infection. Follow-up studies are needed that validate the hand washing method under field conditions, e.g. including people of different age, lower levels of contamination and various levels of hand cleanliness.

  12. Quantitative Assessment of Water Resources Adaptation Policies in Mediterranean Europe

    Science.gov (United States)

    Garrote, L. M.; Mediero, L.; Martin-Carrasco, F.

    2011-12-01

    Many factors challenge water management in Southern Europe: scarce water resources, climate change, population growth, environmental concerns and economic development, among others. Water policy in the region is designed to ensure future sustainability of water resources under strong socioeconomic forcing while maintaining the strategic ecological and social services of water. Climate change is projected to intensify these conflicts, since most models agree that Southern Europe will show a significant drying trend, especially during the second half of the century. For this reason, there is a strong need to integrate climate change adaptation into implementation of the EU Water Framework Directive. From the policy perspective, there are many studies on how climate change might lead to changes in hydrologic regime, water demands, water quality or ecosystems, but there little knowledge on how much water demand might be met with future hydrologic regime. In water scarce regions, water demands are supplied by means of hydraulic infrastructure, which performs functions of storage, transportation and distribution, to overcome the spatio-temporal irregularities of hydrologic regime. Knowledge on the relationship between natural water resources, reservoir storage and water demands is essential to assess the effectiveness of alternative policy options to ensure adequate public water supply. In this paper we provide a simple way to account for the influence of socioeconomic factors (hydraulic infrastructure and water policy) on climate change impacts on water resources in the Mediterranean region. We present a methodology to identify and evaluate climate change adaptation policies in this context. The methodology is based on the application of the WAAPA (Water Availability and Adaptation Policy Assessment) model, which computes net water availability for consumptive use for a river basin taking into account the regulation capacity of its water supply system and a set of

  13. Smile line assessment comparing quantitative measurement and visual estimation

    NARCIS (Netherlands)

    Geld, P. Van der; Oosterveld, P.; Schols, J.; Kuijpers-Jagtman, A.M.

    2011-01-01

    INTRODUCTION: Esthetic analysis of dynamic functions such as spontaneous smiling is feasible by using digital videography and computer measurement for lip line height and tooth display. Because quantitative measurements are time-consuming, digital videography and semiquantitative (visual) estimation

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

    Directory of Open Access Journals (Sweden)

    Sock Keow Tan

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

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

    Science.gov (United States)

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

    2016-01-01

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

  16. Coronary artery bypass graft imaging using ECG-gated multislice computed tomography: Comparison with catheter angiography

    International Nuclear Information System (INIS)

    Moore, R.K.G.; Sampson, C.; MacDonald, S.; Moynahan, C.; Groves, D.; Chester, M.R.

    2005-01-01

    AIM: To compare the value of multislice computerized tomography (MSCT) in imaging coronary artery bypass grafts (CABGs) by direct quantitative comparison with standard invasive angiography. METHODS: Using MSCT, 50 consecutive patients who had previously undergone CABG surgery and had recently undergone invasive angiography for recurrent angina pectoris, were studied further using MSCT after intravenous injection of non-ionic contrast agent; cardiac imaging was performed during a single breath-hold. Graft anatomy was quantified, using both quantitative coronary angiography (QCA) and MSCT, by different investigators blinded to each other. Reproducibility was quantified using the standard error of the measurement expressed as a percentage in log-transformed values (CV%) and intraclass correlation (ICC). RESULTS: All 150 grafts were imaged using MSCT; only 4 patent grafts were not imaged using selective angiography. Good agreement was achieved between MSCT and QCA on assessment of proximal anastomoses (CV% 25.2, ICC 0.84), mid-vessel luminal diameter (CV% 15.5, ICC 0.91) and aneurysmal dilations (CV% 14.3). Reasonable agreement was reached on assessment of distal anastomoses (CV% 26.7, ICC 0.66) and categorization of distal run-off (ICC 0.73). Good agreement was observed for stenoses of over 50% luminal loss (CV% 8.7, ICC 0.97) but agreement on assessment of less severe lesions was poor (CV% 208.7, ICC 0.51). CONCLUSION: This study demonstrates that CABGs can be quantitatively evaluated using MSCT, and that significant lesions present in all CABG segments can be reliably identified. Agreement between MSCT and QCA for lesions of less than 50% luminal loss was poor

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

    International Nuclear Information System (INIS)

    Lim, Soo Jin; Choo, Ki Seok; Park, Yong Hyun; Kim, Jeong Su; Kim, June Hong; Chun, Kook Jin; Jeong, Dong Wook

    2011-01-01

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

  18. Qualitative and quantitative procedures for health risk assessment.

    Science.gov (United States)

    Lohman, P H

    1999-07-16

    Numerous reactive mutagenic electrophiles are present in the environment or are formed in the human body through metabolizing processes. Those electrophiles can directly react with DNA and are considered to be ultimate carcinogens. In the past decades more than 200 in vitro and in vivo genotoxic tests have been described to identify, monitor and characterize the exposure of humans to such agents. When the responses of such genotoxic tests are quantified by a weight-of-evidence analysis, it is found that the intrinsic potency of electrophiles being mutagens does not differ much for the majority of the agents studied. Considering the fact that under normal environmental circumstances human are exposed to low concentration of about a million electrophiles, the relation between exposure to such agents and adverse health effects (e.g., cancer) will become a 'Pandora's box'. For quantitative risk assessment it will be necessary not only to detect whether the agent is genotoxic, but also understand the mechanism of interaction of the agent with the DNA in target cells needs to be taken into account. Examples are given for a limited group of important environmental and carcinogenic agents for which such an approach is feasible. The groups identified are agents that form cross-links with DNA or are mono-alkylating agents that react with base-moieties in the DNA strands. Quantitative hazard ranking of the mutagenic potency of these groups of chemical can be performed and there is ample evidence that such a ranking corresponds with the individual carcinogenic potency of those agents in rodents. Still, in practice, with the exception of certain occupational or accidental exposure situations, these approaches have not be successful in preventing cancer death in the human population. However, this is not only due to the described 'Pandora's box' situation. At least three other factors are described. Firstly, in the industrial world the medical treatment of cancer in patients

  19. Utility of 16-multidetector CT angiography in the preoperative ...

    African Journals Online (AJOL)

    shanker

    calyces and ureters were assessed with delayed excretory phase images. On a 3D workstation, images were ... tional imaging techniques that included conventional angiography for the vascular anatomy and ..... tor CT angiography for evaluating the renal vascular anatomy and possible variations: a pictorial essay. Korean ...

  20. Quantification of fluorescence angiography in a porcine model

    DEFF Research Database (Denmark)

    Nerup, Nikolaj; Andersen, Helene Schou; Ambrus, Rikard

    2017-01-01

    PURPOSE: There is no consensus on how to quantify indocyanine green (ICG) fluorescence angiography. The aim of the present study was to establish and gather validity evidence for a method of quantifying fluorescence angiography, to assess organ perfusion. METHODS: Laparotomy was performed on seven...

  1. Quantitative assessment of deep gas migration in Fennoscandian sites

    International Nuclear Information System (INIS)

    Delos, Anne; Trinchero, Paolo; Richard, Laurent; Molinero, Jorge; Dentz, Marco; Pitkaenen, Petteri

    2010-11-01

    The origin and migration of gases in the geosphere is of interest for performance assessment studies of deep geological repositories of nuclear waste. The presence of dissolved gases in groundwater relates with some safety issues linked to chemical processes. Noble gases, such as helium isotopes, are commonly used as a marker of the paleo hydrogeological evolution, and are good tracers to give information on hydrogeological conditions and groundwater residence time. There are also reactive (non-inert) gases CH 4 , H 2 O, CO 2 , H 2 S, NH 3 , H 2 , and N 2 dissolved in the groundwaters. CH 4 and H 2 are strong reducing agents that may consume oxygen and be involved in microbial sulphate reduction processes. The integrity of the copper canisters in the repository is one of the major issues to be analyzed in the framework of the Swedish program for geological disposal of spent nuclear fuel and dissolved oxygen and sulphide in groundwater are the most damaging components for copper corrosion. Therefore, quantification of flow rates of both, inert and reactive gases, such as helium, methane and hydrogen, in the bedrock would be important for performance assessment calculations. Fluxes of Helium, Methane and Hydrogen at three Fennoscandian sites (Forsmark and Laxemar in Sweden, and Olkiluoto in Finland) have been modelled using Fick's law and measured gradients of gas concentration. Under this hypothesis the concentration is a linear function of depth and hence the gradients can be easily inferred by linear regression. The uncertainty stemming from the scarcity of data and from the diffusivity value used in the analysis has been addressed by sensitivity analysis. Finally, estimates of steady-state gas fluxes of the three Fennoscandian sites are provided. The same data-set has been modelled using the analytical solution provided by Andrews et al. (1989). This solution requires gas production to be constant throughout the domain (which, strictly speaking, is infinite). It

  2. Reliability of a semi-quantitative method for dermal exposure assessment (DREAM)

    NARCIS (Netherlands)

    Wendel de Joode, B. van; Hemmen, J.J. van; Meijster, T.; Major, V.; London, L.; Kromhout, H.

    2005-01-01

    Valid and reliable semi-quantitative dermal exposure assessment methods for epidemiological research and for occupational hygiene practice, applicable for different chemical agents, are practically nonexistent. The aim of this study was to assess the reliability of a recently developed

  3. Evaluation of the applicability of territorial arterial spin labeling in meningiomas for presurgical assessments compared with 3-dimensional time-of-flight magnetic resonance angiography

    International Nuclear Information System (INIS)

    Lu, Yiping; Wen, Jianbo; Geng, Daoying; Yin, Bo; Luan, Shihai; Liu, Li; Xiong, Ji; Qu, Jianxun

    2017-01-01

    To prospectively evaluate the application of territorial arterial spin labelling (t-ASL) in comparison with unenhanced three-dimensional time-of-flight magnetic resonance angiography (3D-TOF-MRA) in the identification of the feeding vasculature of meningiomas. Thirty consecutive patients with suspected meningiomas underwent conventional MR imaging, unenhanced 3D-TOF-MRA and t-ASL scanning. Four experienced neuro-radiologists assessed the feeding vessels with different techniques separately. For the identification of the origin of the feeding arteries on t-ASL, the inter-observer agreement was excellent (κ = 0.913), while the inter-observer agreement of 3D-TOF-MRA was good (κ = 0.653). The inter-modality agreement between t-ASL and 3D-TOF-MRA for the feeding arteries was moderate (κ = 0.514). All 8 patients with motor or sensory disorders proved to have meningiomas supplied completely or partially by the internal carotid arteries, while all 14 patients with meningiomas supplied by the external carotid arteries or basilar arteries didn't show any symptoms concerning motor or sensory disorders (p = 0.003). T-ASL could complement unenhanced 3D-TOF-MRA and increase accuracy in the identification of the supplying arteries of meningiomas in a safe, intuitive, non-radioactive manner. The information about feeding arteries was potentially related to patients' symptoms and pathology, making it more crucial for neurosurgeons in planning surgery as well as evaluating prognosis. (orig.)

  4. Evaluation of the applicability of territorial arterial spin labeling in meningiomas for presurgical assessments compared with 3-dimensional time-of-flight magnetic resonance angiography

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Yiping; Wen, Jianbo; Geng, Daoying; Yin, Bo [Fudan University, Department of Radiology, Huashan Hospital, Shanghai (China); Luan, Shihai [Fudan University, Department of Neurosurgery, Huashan Hospital, Shanghai (China); Liu, Li [Fudan University, Department of Radiology, Shanghai Cancer Center, Shanghai (China); Xiong, Ji [Fudan University, Department of Pathology, Huashan Hospital, Shanghai (China); Qu, Jianxun [GE Healthcare, Department of MR Research, Shanghai (China)

    2017-10-15

    To prospectively evaluate the application of territorial arterial spin labelling (t-ASL) in comparison with unenhanced three-dimensional time-of-flight magnetic resonance angiography (3D-TOF-MRA) in the identification of the feeding vasculature of meningiomas. Thirty consecutive patients with suspected meningiomas underwent conventional MR imaging, unenhanced 3D-TOF-MRA and t-ASL scanning. Four experienced neuro-radiologists assessed the feeding vessels with different techniques separately. For the identification of the origin of the feeding arteries on t-ASL, the inter-observer agreement was excellent (κ = 0.913), while the inter-observer agreement of 3D-TOF-MRA was good (κ = 0.653). The inter-modality agreement between t-ASL and 3D-TOF-MRA for the feeding arteries was moderate (κ = 0.514). All 8 patients with motor or sensory disorders proved to have meningiomas supplied completely or partially by the internal carotid arteries, while all 14 patients with meningiomas supplied by the external carotid arteries or basilar arteries didn't show any symptoms concerning motor or sensory disorders (p = 0.003). T-ASL could complement unenhanced 3D-TOF-MRA and increase accuracy in the identification of the supplying arteries of meningiomas in a safe, intuitive, non-radioactive manner. The information about feeding arteries was potentially related to patients' symptoms and pathology, making it more crucial for neurosurgeons in planning surgery as well as evaluating prognosis. (orig.)

  5. Impact of ECG gating in contrast-enhanced MR angiography for the assessment of the pulmonary veins and the left atrium anatomy

    Energy Technology Data Exchange (ETDEWEB)

    Katoh, M.; Buecker, A.; Muehlenbruch, G.; Guenther, R.W.; Spuentrup, E. [Klinik fuer Radiologische Diagnostik, Universitaetsklinikum RWTH Aachen (Germany); Schauerte, P. [Medizinische Klinik 1, Universitaetsklinikum RWTH Aachen (Germany)

    2006-02-15

    Purpose: Implementation of ECG gating in contrast-enhanced MR angiography (ceMRA) for improved visualization of the pulmonary veins, the left atrium, and the thoracic vessels. Materials and Methods: CeMRA was performed on twelve patients with a history of recurrent atrial fibrillation for the purpose of an intra-individual comparison with and without ECG gating on a 1.5 Tesla MR system (Gyroscan Intera, Philips Medical Systems, Best, NL). Objective image quality parameters such as the signal-to-noise ratio (SNR) of the blood and the contrast-to-noise ratio (CNR) between the blood and myocardium or lung parenchyma were analyzed. The contour sharpness of the pulmonary veins, left atrium, ascending aorta, and pulmonary trunk was also measured. In addition, the artifact level was subjectively assessed by two observers blinded with respect to the sequence parameters. Statistically significant differences (p<0.05) between the procedures were analyzed using the Wilcoxon test and Pearson Chi-square test. Results: The use of ECG gating in ceMRA significantly reduced artifacts caused by cardiac motion and vessel pulsation. This in turn lead to a significant increase in the contour sharpness of the left atrium and the thoracic vessels. In addition, higher SNR and CNR were found using ECG-gated ceMRA compared to standard ceMRA. Conclusion: The use of ECG gating in ceMRA results in artifact-free and sharper delineation of the structures of the heart and thoracic vessels. (orig.)

  6. Isotropic high-spatial-resolution contrast-enhanced 3.0-T MR angiography in patients suspected of having renal artery stenosis.

    Science.gov (United States)

    Kramer, Ulrich; Wiskirchen, Jakub; Fenchel, Michael C; Seeger, Achim; Laub, Gerhard; Tepe, Gunnar; Finn, J Paul; Claussen, Claus D; Miller, Stephan

    2008-04-01

    The purpose of this study was to prospectively evaluate the diagnostic performance of contrast material-enhanced magnetic resonance (MR) angiography performed at 3 T for assessment of renal artery stenosis (RAS) by using parallel acquisition techniques with high acceleration factors and with digital subtraction angiography (DSA) as the reference standard. The study was institutional review board approved, and written informed consent was obtained from all patients. Twenty-nine patients (18 men, 11 women; mean age, 57.1 years +/- 14.3 [standard deviation]) suspected of having RAS underwent MR angiography. Images were evaluated qualitatively and quantitatively. The interobserver variability, sensitivity, specificity, and positive and negative predictive values of 3-T MR angiography, as compared with DSA (performed in 15 patients), were calculated. All examinations yielded good or excellent image quality. The sensitivity and specificity of MR angiography in grading significant (>75%) stenosis were 94% and 96%, respectively. Owing to its high sensitivity, contrast-enhanced 3-T MR angiography can be used reliably to exclude RAS and can serve as a useful screening method in the diagnostic work-up of patients with arterial hypertension.

  7. Quantitative assessment of surf-produced sea spray aerosol

    NARCIS (Netherlands)

    Neele, F.P.; De Leeuw, G.; Jansen, M.; Stive, M.J.F.

    1998-01-01

    The first results are presented from a quantitative model describing the aerosol production in the surf zone. A comparison is made with aerosol produced in the surf zone as measured during EOPACE experiments in La Jolla and Monterey. The surf aerosol production was derived from aerosol concentration

  8. Rapid quantitative assessment of gastric corpus atrophy in tissue sections

    NARCIS (Netherlands)

    van Grieken, N. C.; Weiss, M. M.; Meijer, G. A.; Bloemena, E.; Lindeman, J.; Offerhaus, G. J.; Meuwissen, S. G.; Baak, J. P.; Kuipers, E. J.

    2001-01-01

    Grading of Helicobacter pylori induced atrophic gastritis using the updated Sydney system is severely limited by high interobserver variability. The aim of this study was to set up a quantitative test of gastric corpus mucosal atrophy in tissue sections and test its reproducibility and correlation

  9. Edge detection versus densitometry for assessing coronary stenting quantitatively

    NARCIS (Netherlands)

    B.H. Strauss (Bradley); Y. Juilliere; B.J.W.M. Rensing (Benno); J.H.C. Reiber (Johan); P.W.J.C. Serruys (Patrick)

    1991-01-01

    textabstractThe optimal method used to analyze quantitatively the immediate angiographic results of coronary stenting in the coronary arteries has not been studied. Accordingly, minimal luminal cross-sectional area was determined by 2 methods, edge detection and densitometry, in 19 patients who

  10. Smile line assessment comparing quantitative measurement and visual estimation.

    Science.gov (United States)

    Van der Geld, Pieter; Oosterveld, Paul; Schols, Jan; Kuijpers-Jagtman, Anne Marie

    2011-02-01

    Esthetic analysis of dynamic functions such as spontaneous smiling is feasible by using digital videography and computer measurement for lip line height and tooth display. Because quantitative measurements are time-consuming, digital videography and semiquantitative (visual) estimation according to a standard categorization are more practical for regular diagnostics. Our objective in this study was to compare 2 semiquantitative methods with quantitative measurements for reliability and agreement. The faces of 122 male participants were individually registered by using digital videography. Spontaneous and posed smiles were captured. On the records, maxillary lip line heights and tooth display were digitally measured on each tooth and also visually estimated according to 3-grade and 4-grade scales. Two raters were involved. An error analysis was performed. Reliability was established with kappa statistics. Interexaminer and intraexaminer reliability values were high, with median kappa values from 0.79 to 0.88. Agreement of the 3-grade scale estimation with quantitative measurement showed higher median kappa values (0.76) than the 4-grade scale estimation (0.66). Differentiating high and gummy smile lines (4-grade scale) resulted in greater inaccuracies. The estimation of a high, average, or low smile line for each tooth showed high reliability close to quantitative measurements. Smile line analysis can be performed reliably with a 3-grade scale (visual) semiquantitative estimation. For a more comprehensive diagnosis, additional measuring is proposed, especially in patients with disproportional gingival display. Copyright © 2011 American Association of Orthodontists. Published by Mosby, Inc. All rights reserved.

  11. A preliminary quantitative assessment of gillnet fishing in subtropical ...

    African Journals Online (AJOL)

    Between January 1998 and January 1999 a quantitative investigation was done on the fish populations of Lake Tzaneen, Northern Province, South Africa. Two graded series of multi-filament gillnets were set overnight every six weeks capturing 14 species of fish. Of the 2 692 fish caught, Schilbe intermedius was most ...

  12. Assessment of perfusion pattern and extent of perfusion defect on dual-energy CT angiography: Correlation between the causes of pulmonary hypertension and vascular parameters

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Eun Young [Dept. of Radiology, Chonbuk National University Medical School and Hospital, Research Institute of Clinical Medicine, Jeonju (Korea, Republic of); Seo, Joon Beom; Oh, Sang Young; Lee, Choong Wook; Lee, Sang Min [Dept. of Radiology and Research Institute of Radiology, University of Ulsan College of Medicine, Asan Medical Center, Seoul (Korea, Republic of); Hwang, Hye Jeon [Dept. of Radiology, Hallym University College of Medicine, Hallym University Sacred Heart Hospital, Anyang (Korea, Republic of); Lee, Young Kyung [Dept. of Radiology, Seoul Medical Center, Seoul (Korea, Republic of)

    2014-04-15

    To assess perfusion patterns on a dual-energy pulmonary CT angiography (DECTA) of pulmonary hypertension (PHT) with variable causes and to assess whether the extent of perfusion defect can be used in the severity assessment of PHT. Between March 2007 and February 2011, DECTA scans of 62 consecutive patients (24 men, 38 women; mean age, 58.5 ± 17.3 [standard deviation] years; range, 19-87 years) with PHT were retrospectively included with following inclusion criteria; 1) absence of acute pulmonary thromboembolism, 2) maximal velocity of tricuspid regurgitation jet (TR Vmax) above 3 m/s on echocardiography performed within one week of the DECTA study. Perfusion patterns of iodine map were divided into normal (NL), diffuse heterogeneously decreased (DH), multifocal geographic and multiple peripheral wedging patterns. The extent of perfusion defects (PD), the diameter of main pulmonary artery (MPA) and the ratio of ascending aorta diameter/MPA (aortopulmonary ratio, APR) were measured. Pearson correlation analysis was performed between TR Vmax on echocardiography and CT imaging parameters. Common perfusion patterns of primary PHT were DH (n = 15) and NL (n = 12). The perfusion patterns of secondary PHT were variable. On the correlation analysis, in primary PHT, TR Vmax significantly correlated with PD, MPA and APR (r = 0.52, r = 0.40, r = -0.50, respectively, all p < 0.05). In secondary PHT, TR Vmax significantly correlated with PD and MPA (r = 0.38, r = 0.53, respectively, all p < 0.05). Different perfusion patterns are observed on DECTA of PHT according to the causes. PD and MPA are significantly correlated with the TR Vmax.

  13. Assessment for Improvement: Two Models for Assessing a Large Quantitative Reasoning Requirement

    Directory of Open Access Journals (Sweden)

    Mary C. Wright

    2015-03-01

    Full Text Available We present two models for assessment of a large and diverse quantitative reasoning (QR requirement at the University of Michigan. These approaches address two key challenges in assessment: (1 dissemination of findings for curricular improvement and (2 resource constraints associated with measurement of large programs. Approaches we present for data collection include convergent validation of self-report surveys, as well as use of mixed methods and learning analytics. Strategies we present for dissemination of findings include meetings with instructors to share data and best practices, sharing of results through social media, and use of easily accessible dashboards. These assessment approaches may be of particular interest to universities with large numbers of students engaging in a QR experience, projects that involve multiple courses with diverse instructional goals, or those who wish to promote evidence-based curricular improvement.

  14. Assessing framing assumptions in quantitative health impact assessments: a housing intervention example.

    Science.gov (United States)

    Mesa-Frias, Marco; Chalabi, Zaid; Foss, Anna M

    2013-09-01

    Health impact assessment (HIA) is often used to determine ex ante the health impact of an environmental policy or an environmental intervention. Underpinning any HIA is the framing assumption, which defines the causal pathways mapping environmental exposures to health outcomes. The sensitivity of the HIA to the framing assumptions is often ignored. A novel method based on fuzzy cognitive map (FCM) is developed to quantify the framing assumptions in the assessment stage of a HIA, and is then applied to a housing intervention (tightening insulation) as a case-study. Framing assumptions of the case-study were identified through a literature search of Ovid Medline (1948-2011). The FCM approach was used to identify the key variables that have the most influence in a HIA. Changes in air-tightness, ventilation, indoor air quality and mould/humidity have been identified as having the most influence on health. The FCM approach is widely applicable and can be used to inform the formulation of the framing assumptions in any quantitative HIA of environmental interventions. We argue that it is necessary to explore and quantify framing assumptions prior to conducting a detailed quantitative HIA during the assessment stage. Copyright © 2013 Elsevier Ltd. All rights reserved.

  15. Correlation of angiography and MR imaging in cerebral vasculitis

    International Nuclear Information System (INIS)

    Cloft, H.J.; Phillips, C.D.; Dix, J.E.; McNulty, B.C.; Kallmes, D.F.; Zagardo, M.T.

    1999-01-01

    Purpose: MR imaging and cerebral angiography were correlated in patients with primary angiitis of the central nervous system (PACNS) to assess the relative roles of these imaging modalities in the diagnosis. Material and Methods: In 9 patients, MR imaging and angiography were compared with regard to the relative involvement of each major vascular territory. Vascular territories assessed were the anterior, middle, and posterior cerebral arteries, and the posterior fossa. Results: All patients had angiographic findings consistent with vasculitis in multiple vascular territories. MR findings ranged from normal to diffusely abnormal. One patient had a completely normal MR investigation. Of 50 territories affected by vasculitis on angiography, 17 (34%) were normal on MR. Conclusion: Relative to cerebral angiography, MR imaging is a poor indicator of the presence or absence of PACNS. Angiography is indicated when clinical suspicion of PACNS is strong, regardless of the findings on MR. (orig.)

  16. Digital subtraction angiography (DSA)

    International Nuclear Information System (INIS)

    Lackner, K.; Janson, R.; Franken, T.; Harder, T.; Thurn, P.

    1983-01-01

    Digital subtraction angiography is an advanced subtraction technique and a new field in which i.v. injection of contrast media is required. Conventional techniques involving i.v. injection of contrast media have the following drawbacks: 1. High amounts of contrast media; 2. simultaneous injection into the brachial veins of both arms; 3. poor imaging of blood vessels in regions with strongly varying X-ray absorption characteristics of the background; 4. no possibility of contrast amplification. In conventional subtraction techniques, image processing takes place as a second step after the examination, so that results are not immediately available for interpretation. Digital subtraction angiography largely avoids these drawbacks. (orig./MG) [de

  17. Quality of abdominal computed tomography angiography: hand versus mechanical intravenous contrast administration in children

    International Nuclear Information System (INIS)

    Ayyala, Rama S.; Lee, Edward Y.; Zurakowski, David

    2015-01-01

    Abdominal CT angiography has been increasingly used for evaluation of various conditions related to abdominal vasculature in the pediatric population. However, no direct comparison has evaluated the quality of abdominal CT angiography in children using hand versus mechanical administration of intravenous (IV) contrast agent. To compare hand versus mechanical administration of IV contrast agent in the quality of abdominal CT angiography in the pediatric population. We retrospectively reviewed the electronic medical record to identify pediatric patients (≤18 years) who had abdominal CT angiography between August 2012 and August 2013. The information obtained includes: (1) type of administration of IV contrast agent (hand [group 1] versus mechanical [group 2]), (2) size (gauge) of IV catheter, (3) amount of contrast agent administered and (4) rate of contrast agent administration (ml/s). Two reviewers independently performed qualitative and quantitative evaluation of abdominal CT angiography image quality. Qualitative evaluation of abdominal CT angiography image quality was performed by visual assessment of the degree of contrast enhancement in the region of interest (ROI) based on a 4-point scale. Quantitative evaluation of each CT angiography examination was performed by measuring the Hounsfield unit (HU) using an ROI within the abdominal aorta at two levels (celiac axis and the inferior mesenteric artery) for each child. Analysis of variance (ANOVA) using the F-test was applied to compare contrast enhancement within the abdominal aorta at two levels (celiac axis and inferior mesenteric artery) between hand administration and mechanical administration of IV contrast methods with adjustment for age. We identified 46 pediatric patients (24 male, 22 female; mean age 7.3 ± 5.5 years; range 5 weeks to 18 years) with abdominal CT angiography performed during the study period. Of these patients, 16 (35%; 1.7 ± 2.2 years; range 5 weeks to 5 years) had hand

  18. Quality of abdominal computed tomography angiography: hand versus mechanical intravenous contrast administration in children

    Energy Technology Data Exchange (ETDEWEB)

    Ayyala, Rama S.; Lee, Edward Y. [Boston Children' s Hospital and Harvard Medical School, Department of Radiology, Boston, MA (United States); Zurakowski, David [Boston Children' s Hospital and Harvard Medical School, Departments of Anesthesiology and Surgery, Boston, MA (United States)

    2015-11-15

    Abdominal CT angiography has been increasingly used for evaluation of various conditions related to abdominal vasculature in the pediatric population. However, no direct comparison has evaluated the quality of abdominal CT angiography in children using hand versus mechanical administration of intravenous (IV) contrast agent. To compare hand versus mechanical administration of IV contrast agent in the quality of abdominal CT angiography in the pediatric population. We retrospectively reviewed the electronic medical record to identify pediatric patients (≤18 years) who had abdominal CT angiography between August 2012 and August 2013. The information obtained includes: (1) type of administration of IV contrast agent (hand [group 1] versus mechanical [group 2]), (2) size (gauge) of IV catheter, (3) amount of contrast agent administered and (4) rate of contrast agent administration (ml/s). Two reviewers independently performed qualitative and quantitative evaluation of abdominal CT angiography image quality. Qualitative evaluation of abdominal CT angiography image quality was performed by visual assessment of the degree of contrast enhancement in the region of interest (ROI) based on a 4-point scale. Quantitative evaluation of each CT angiography examination was performed by measuring the Hounsfield unit (HU) using an ROI within the abdominal aorta at two levels (celiac axis and the inferior mesenteric artery) for each child. Analysis of variance (ANOVA) using the F-test was applied to compare contrast enhancement within the abdominal aorta at two levels (celiac axis and inferior mesenteric artery) between hand administration and mechanical administration of IV contrast methods with adjustment for age. We identified 46 pediatric patients (24 male, 22 female; mean age 7.3 ± 5.5 years; range 5 weeks to 18 years) with abdominal CT angiography performed during the study period. Of these patients, 16 (35%; 1.7 ± 2.2 years; range 5 weeks to 5 years) had hand

  19. Simple Macroeconomic Policies and Welfare: A Quantitative Assessment

    Directory of Open Access Journals (Sweden)

    Eurilton Araújo

    2014-09-01

    Full Text Available We quantitatively compare three macroeconomic policies in a cash-credit goods framework. The policies are: the optimal one; another one that fully smoothes out oscillations in output; and a simple one that prescribes constant values for tax and monetary growth rates. As often found in the related literature, the welfare gains or losses from changing from a given policy to another are small. We also show that the simple policy dominates the one that leads to constant output.

  20. Quantitative assessments of distributed systems methodologies and techniques

    CERN Document Server

    Bruneo, Dario

    2015-01-01

    Distributed systems employed in critical infrastructures must fulfill dependability, timeliness, and performance specifications. Since these systems most often operate in an unpredictable environment, their design and maintenance require quantitative evaluation of deterministic and probabilistic timed models. This need gave birth to an abundant literature devoted to formal modeling languages combined with analytical and simulative solution techniques The aim of the book is to provide an overview of techniques and methodologies dealing with such specific issues in the context of distributed

  1. Exercise intravenous digital subtraction angiography

    International Nuclear Information System (INIS)

    Yiannikas, J.

    1986-01-01

    Attempts to use exercise ventriculography have been made, not only to give diagnostic and perhaps even prognostic information in patients with coronary artery disease, but also in patients with valvular heart disease both before and after surgical intervention. Clearly an accurate method of assessing ventricular function under conditions of stress in various cardiac diseases would provide important information that would help in patient management. Exercise ventriculography using gated blood pool equilibrium technetium studies are widely used, but are limited by spatial resolution and by the foreshortening affects of visualizing the left ventricular chamber in the left anterior oblique view. First pass radionuclide studies have the added advantage of being able to visualize the ventricular chamber in the anterior or even the right anterior oblique view, but are even more limited by their spatial resolution problems. Several investigations have shown that digital subtraction angiography produces left ventricular images with a spatial resolution almost identical to that of conventional contrast ventriculography, but without the inherent problems of cardiac arrhythmias, which often limit the assessment of left ventricular function. Because of its ability to accurately delineate wall motion abnormalities, the technique may provide an adequate assessment of global and regional left ventricular function after exercise. Digital subtraction angiography may identify ischemic wall motion abnormalities produced by exercise in patients who already had significant permanent left ventricular damage from myocardial infarction

  2. Diagnostic Accuracy of Coronary CT Angiography for the Evaluation of Bioresorbable Vascular Scaffolds.

    Science.gov (United States)

    Collet, Carlos; Chevalier, Bernard; Cequier, Angel; Fajadet, Jean; Dominici, Marcello; Helqvist, Steffen; Van Boven, A J; Dudek, Dariusz; McClean, Dougal; Almeida, Manuel; Piek, Jan J; Tenekecioglu, Erhan; Bartorelli, Antonio; Windecker, Stephan; Serruys, Patrick W; Onuma, Yoshinobu

    2017-07-13

    To assess the diagnostic accuracy of coronary computed tomography angiography (CTA) for bioresorbable vascular scaffold (BVS) evaluation. Coronary CTA has emerged as a noninvasive method to evaluate patients with suspected or established coronary artery disease. The diagnostic accuracy of coronary CTA to evaluate angiographic outcomes after BVS implantation has not been well established. In the ABSORB II (A Bioresorbable Everolimus-Eluting Scaffold Versus a Metallic Everolimus-Eluting Stent II) study, patients were randomized either to receive treatment with the BVS or everolimus-eluting metallic stent. At the 3-year follow-up, 238 patients (258 lesions) treated with BVS underwent coronary angiography with intravascular ultrasound (IVUS) evaluation and coronary CTA. The diagnostic accuracy of coronary CTA was assessed by the area under the receiver-operating characteristic curve with coronary angiography and IVUS as references. The mean difference in coronary CTA-derived minimal luminal diameter was -0.14 mm (limits of agreement -0.88 to 0.60) with quantitative coronary angiography as reference, whereas the mean difference in minimal lumen area was 0.73 mm 2 (limits of agreement -1.85 to 3.30) with IVUS as reference. The per-scaffold diagnostic accuracy of coronary CTA for detecting stenosis based on coronary angiography diameter stenosis of ≥50% revealed an area under the receiver-operating characteristic curve of 0.88 (95% confidence interval [CI]: 0.82 to 0.92) with a sensitivity of 80% (95% CI: 28 to 99) and a specificity of 100% (95% CI: 98 to 100), whereas diagnostic accuracy based on IVUS minimal lumen area ≤2.5 mm 2 showed an area under the receiver-operating characteristic curve of 0.83 (95% CI: 0.77 to 0.88) with a sensitivity of 71% (95% CI: 44 to 90) and a specificity of 82% (95% CI: 75 to 87). The diagnostic accuracy of coronary CTA was similar to coronary angiography in its ability to identify patients with a significant lesion based on the

  3. Assessing Student Teachers' Reflective Writing through Quantitative Content Analysis

    Science.gov (United States)

    Poldner, Eric; Van der Schaaf, Marieke; Simons, P. Robert-Jan; Van Tartwijk, Jan; Wijngaards, Guus

    2014-01-01

    Students' reflective essay writing can be stimulated by the formative assessments provided to them by their teachers. Such assessments contain information about the quality of students' reflective writings and offer suggestions for improvement. Despite the importance of formatively assessing students' reflective writings in teacher education…

  4. Reduction of metal artifacts due to dental hardware in computed tomography angiography: assessment of the utility of model-based iterative reconstruction

    Energy Technology Data Exchange (ETDEWEB)

    Kuya, Keita; Shinohara, Yuki; Ogawa, Toshihide [Tottori University, Division of Radiology, Department of Pathophysiological and Therapeutic Science, Faculty of Medicine, Yonago (Japan); Kato, Ayumi [Tottori Municipal Hospital, Department of Radiology, Yonago (Japan); Sakamoto, Makoto; Kurosaki, Masamichi [Tottori University, Division of Neurosurgery, Department of Neurological Sciences, Faculty of Medicine, Yonago (Japan)

    2017-03-15

    The aim of this study is to assess the value of adaptive statistical iterative reconstruction (ASIR) and model-based iterative reconstruction (MBIR) for reduction of metal artifacts due to dental hardware in carotid CT angiography (CTA). Thirty-seven patients with dental hardware who underwent carotid CTA were included. CTA was performed with a GE Discovery CT750 HD scanner and reconstructed with filtered back projection (FBP), ASIR, and MBIR. We measured the standard deviation at the cervical segment of the internal carotid artery that was affected most by dental metal artifacts (SD{sub 1}) and the standard deviation at the common carotid artery that was not affected by the artifact (SD{sub 2}). We calculated the artifact index (AI) as follows: AI = [(SD{sub 1})2 - (SD{sub 2})2]1/2 and compared each AI for FBP, ASIR, and MBIR. Visual assessment of the internal carotid artery was also performed by two neuroradiologists using a five-point scale for each axial and reconstructed sagittal image. The inter-observer agreement was analyzed using weighted kappa analysis. MBIR significantly improved AI compared with FBP and ASIR (p < 0.001, each). We found no significant difference in AI between FBP and ASIR (p = 0.502). The visual score of MBIR was significantly better than those of FBP and ASIR (p < 0.001, each), whereas the scores of ASIR were the same as those of FBP. Kappa values indicated good inter-observer agreements in all reconstructed images (0.747-0.778). MBIR resulted in a significant reduction in artifact from dental hardware in carotid CTA. (orig.)

  5. Successful treatment of Raynaud's phenomenon and digital ulcers in systemic sclerosis patients with botulinum toxin B injection: Assessment of peripheral vascular disorder by angiography and dermoscopic image of nail fold capillary.

    Science.gov (United States)

    Motegi, Sei-Ichiro; Sekiguchi, Akiko; Saito, Shintaro; Ishibuchi, Hirohisa; Kishi, Chikako; Yasuda, Masahito; Ishikawa, Osamu

    2018-03-01

    We recently identified the efficacy and safety of a botulinum toxin (BTX)-A/B in Raynaud's phenomenon (RP) and digital ulcers (DU) in Japanese patients with systemic sclerosis (SSc). Detailed assessments of peripheral vascular disorder using angiography and dermoscopic images of nail fold capillaries have not been performed previously. This study aimed to evaluate the effect of BTX-B on SSc-associated peripheral vascular disorder. Two SSc patients who suffered with RP and DU were treated with a BTX-B injection, and thereafter the symptoms of RP were improved and DU healed in both patients. Furthermore, angiography showed an increased blood flow to the palm and fingers, and dermoscopic images of nail fold capillary changes showed improvement. These results suggest that a BTX-B injection may increase peripheral blood flow and improve RP and DU in SSc patients. © 2017 Japanese Dermatological Association.

  6. A quantitative coronary angiography-matched comparison between a prospective randomised multicentre cutting balloon angioplasty and bare metal stent trial (REDUCE III) and the Rapamycin-Eluting Stent Evaluation At Rotterdam Cardiology Hospital (RESEARCH) study.

    Science.gov (United States)

    Ozaki, Yukio; Lemos, Pedro A; Yamaguchi, Tetsu; Suzuki, Takahiko; Nakamura, Masato; Ismail, Tevfik F; Kitayama, Michihiko; Nishikawa, Hideo; Kato, Osamu; Serruys, Patrick W

    2010-08-01

    There remains significant concern about the long-term safety of drug-eluting stents (DES). However, bare metal stents (BMS) have been used safely for over two decades. There is therefore a pressing need to explore alternative strategies for reducing restenosis with BMS. This study was designed to examine whether IVUS-guided cutting balloon angioplasty (CBA) with BMS could convey similar restenosis rates to DES. In the randomised REstenosis reDUction by Cutting balloon angioplasty Evaluation (REDUCE III) study, 521 patients were divided into four groups based on device and IVUS use before BMS (IVUS-CBA-BMS: 137 patients; Angio-CBA-BMS: 123; IVUS-BA-BMS: 142; and Angio-BA-BMS: 119). At follow-up, the IVUS-CBA-BMS group had a significantly lower restenosis rate (6.6%) than the other groups (p=0.016). We performed a quantitative coronary angiography (QCA) based matched comparison between an IVUS-guided CBA-BMS strategy (REDUCE III) and a DES strategy (Rapamycin-Eluting-Stent Evaluation At Rotterdam Cardiology Hospital, the RESEARCH study). We matched the presence of diabetes, vessel size, and lesion severity by QCA. Restenosis (>50% diameter stenosis at follow-up) and target vessel revascularisation (TVR) were examined. QCA-matched comparison resulted in 120-paired lesions. While acute gain was significantly greater in IVUS-CBA-BMS than DES (1.65±0.41 mm vs. 1.28±0.57 mm, p=0.001), late loss was significantly less with DES than with IVUS-CBA-BMS (0.03±0.42 mm vs. 0.80±0.47 mm, p=0.001). However, no difference was found in restenosis rates (IVUS-CBA-BMS: 6.6% vs. DES: 5.0%, p=0.582) and TVR (6.6% and 6.6%, respectively). An IVUS-guided CBA-BMS strategy yielded restenosis rates similar to those achieved by DES and provided an effective alternative to the use of DES.

  7. Quantitative phylogenetic assessment of microbial communities indiverse environments

    Energy Technology Data Exchange (ETDEWEB)

    von Mering, C.; Hugenholtz, P.; Raes, J.; Tringe, S.G.; Doerks,T.; Jensen, L.J.; Ward, N.; Bork, P.

    2007-01-01

    The taxonomic composition of environmental communities is an important indicator of their ecology and function. Here, we use a set of protein-coding marker genes, extracted from large-scale environmental shotgun sequencing data, to provide a more direct, quantitative and accurate picture of community composition than traditional rRNA-based approaches using polymerase chain reaction (PCR). By mapping marker genes from four diverse environmental data sets onto a reference species phylogeny, we show that certain communities evolve faster than others, determine preferred habitats for entire microbial clades, and provide evidence that such habitat preferences are often remarkably stable over time.

  8. Angiography in renal diagnostics

    International Nuclear Information System (INIS)

    Schreyer, H.; Justich, E.; Graz Univ.

    1982-01-01

    The angiographic symptoms of kidney vessels diseases are described as well as traumas and growing and displacing processes of the kidneys. The diagnostic value of angiography in kidney traumas and growing and displacing processes of the kidney is discussed and compared with other techniques, e.g. urography, sonography and computed tomography. (orig.) [de

  9. Assessment of the health impact of an environmental pollution and quantitative assessment of health risks

    International Nuclear Information System (INIS)

    2005-09-01

    The report made by a working group is written for experts in health risk assessment or for professionals involved in risk management. It proposes a methodological and conceptual framework which could build a unified approach to a quantitative assessment of health risks. In the first part, under the form of questions and answers, it defines the health impact, describes how to assess the excess of individual risk and the related hypothesis, how to pass from the excess of individual risk to the health impact, how to express the results of an health impact calculation, how to take the lack of knowledge into account at the different steps of this calculation, what is the significance of the result of such a calculation, and how useful an health impact assessment can be. The second part proposes a more detailed presentation of the scientific background for the health impact calculation with its indicators, its uncertainties, its practice in other countries, its relevance, and its fields of application. Then, after a comment of the dose-response relationship, it reports the scientific validity of the assessment of a number of cases

  10. Clinical assessment of rosacea severity: oriental score vs. quantitative assessment method with imaging and biomedical tools.

    Science.gov (United States)

    Kim, J; Ahn, J W; Ha, S; Kwon, S H; Lee, O; Oh, C

    2017-05-01

    Rosacea is a common chronic inflammatory disorder affecting facial skin. Currently, no accurate and objective method is available for assessing the severity of rosacea. Most studies use the National Rosacea Society Standard (NRSS) grading method, which lacks objectivity and yields varying results. Eighteen patients with rosacea were included. Clinical severity was assessed on the basis of the NRSS grade, Investigators' Global Assessment, Patients' Global Assessment, and Dermatology Quality of Life Index. A skin color analysis system was used to measure the facial area showing erythema, and biophysical parameters of facial skin (transepidermal water loss and skin surface hydration) were examined. To find statistical significant in classification severity of the rosacea, statistical analysis was performed with all parameters. A significant correlation (P rosacea of different levels of severity (mild, moderate, severe; P rosacea, in addition to biophysical parameter assessment. The combination of these two analytical methods enabled objective and quantitative evaluation of the severity of rosacea. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  11. Quantitative Assessment of Landscape Load Caused by Mining Activity

    Directory of Open Access Journals (Sweden)

    Csüllög Gábor

    2017-06-01

    Full Text Available In Hungary, not only the aftermath of the extraction in the past nearly 150 years, but also the economic changes taking place in the past two decades have had significant environmental consequences manifested, above all, in the landscape. It is, however, not sufficient to investigate the landscape components separately; it is necessary to explore connections within the landscape. Accordingly, the chief aim of this presentation has been, on the one hand, to work out the method of landscape load index, based on a quantitative database of mining claims and deposits of mining waste, which has revealed their impacts on the landscape as well. On the other hand, we have also aimed at developing the method of the mining load index of certain geographical landscape units. By calculating and analysing the indices, we have intended to build a quantitative database suitable for investigating the impacts of mining activities on the landscape. On the basis of the indices, the impacts and consequences could be ranked, and it was also possible to compare the impacts of different mining claims and waste deposits in three different landscape categories. With the main result of our examination, this will make it possible to investigate concrete problems and landscape conflicts caused by the landscape use of mining or its aftermath in different landscape units with a high load index.

  12. Quantitative ultrasound and photoacoustic imaging for the assessment of vascular parameters

    CERN Document Server

    Meiburger, Kristen M

    2017-01-01

    This book describes the development of quantitative techniques for ultrasound and photoacoustic imaging in the assessment of architectural and vascular parameters. It presents morphological vascular research based on the development of quantitative imaging techniques for the use of clinical B-mode ultrasound images, and preclinical architectural vascular investigations on quantitative imaging techniques for ultrasounds and photoacoustics. The book is divided into two main parts, the first of which focuses on the development and validation of quantitative techniques for the assessment of vascular morphological parameters that can be extracted from B-mode ultrasound longitudinal images of the common carotid artery. In turn, the second part highlights quantitative imaging techniques for assessing the architectural parameters of vasculature that can be extracted from 3D volumes, using both contrast-enhanced ultrasound (CEUS) imaging and photoacoustic imaging without the addition of any contrast agent. Sharing and...

  13. MR angiography of lower extremity

    International Nuclear Information System (INIS)

    Fujikawa, Takao

    1991-01-01

    MR angiography by ECG-gated 2D rephase-dephase subtraction method was performed in normal volunteers (n=14) and patients with arterial or venous vascular disease of lower extremities (n=36). Results were compared to digital subtraction angiography or conventional film angiography. In normal cases, superficial femoral and popliteal arteries were well demonstrated by angiography whereas visualization of intrapelvic portion of the arteries was often impaired by mortion artifacts from bowel loops. Diagnostic results of MR angiography and digital or conventional angiography were in agreement in 92.3% of obstructive arteriosclerotic disease, 87.0% of post by-pass graft surgery, and 85.7% of cases in which deep vein thrombosis was clinically suspected. Considering its virtually noninvasive nature, MR angiography can be a valuable screening method in vascular diseases of lower extremities and also in post operative evaluation of by-pass graft surgery. Further technical advancements are expected. (author)

  14. MR angiography of lower extremity

    Energy Technology Data Exchange (ETDEWEB)

    Fujikawa, Takao (Kyorin Univ., Mitaka, Tokyo (Japan). School of Medicine)

    1991-02-01

    MR angiography by ECG-gated 2D rephase-dephase subtraction method was performed in normal volunteers (n=14) and patients with arterial or venous vascular disease of lower extremities (n=36). Results were compared to digital subtraction angiography or conventional film angiography. In normal cases, superficial femoral and popliteal arteries were well demonstrated by angiography whereas visualization of intrapelvic portion of the arteries was often impaired by mortion artifacts from bowel loops. Diagnostic results of MR angiography and digital or conventional angiography were in agreement in 92.3% of obstructive arteriosclerotic disease, 87.0% of post by-pass graft surgery, and 85.7% of cases in which deep vein thrombosis was clinically suspected. Considering its virtually noninvasive nature, MR angiography can be a valuable screening method in vascular diseases of lower extremities and also in post operative evaluation of by-pass graft surgery. Further technical advancements are expected. (author).

  15. Cerebral Hemodynamics in Patients with Hemolytic Uremic Syndrome Assessed by Susceptibility Weighted Imaging and Four-Dimensional Non-Contrast MR Angiography.

    Science.gov (United States)

    Löbel, Ulrike; Forkert, Nils Daniel; Schmitt, Peter; Dohrmann, Thorsten; Schroeder, Maria; Magnus, Tim; Kluge, Stefan; Weiler-Normann, Christina; Bi, Xiaoming; Fiehler, Jens; Sedlacik, Jan

    2016-01-01

    Conventional magnetic resonance imaging (MRI) of patients with hemolytic uremic syndrome (HUS) and neurological symptoms performed during an epidemic outbreak of Escherichia coli O104:H4 in Northern Europe has previously shown pathological changes in only approximately 50% of patients. In contrast, susceptibility-weighted imaging (SWI) revealed a loss of venous contrast in a large number of patients. We hypothesized that this observation may be due to an increase in cerebral blood flow (CBF) and aimed to identify a plausible cause. Baseline 1.5T MRI scans of 36 patients (female, 26; male, 10; mean age, 38.2±19.3 years) were evaluated. Venous contrast was rated on standard SWI minimum intensity projections. A prototype four-dimensional (time resolved) magnetic resonance angiography (4D MRA) assessed cerebral hemodynamics by global time-to-peak (TTP), as a surrogate marker for CBF. Clinical parameters studied were hemoglobin, hematocrit, creatinine, urea levels, blood pressure, heart rate, and end-tidal CO2. SWI venous contrast was abnormally low in 33 of 36 patients. TTP ranged from 3.7 to 10.2 frames (mean, 7.9 ± 1.4). Hemoglobin at the time of MRI (n = 35) was decreased in all patients (range, 5.0 to 12.6 g/dL; mean, 8.2 ± 1.4); hematocrit (n = 33) was abnormally low in all but a single patient (range, 14.3 to 37.2%; mean, 23.7 ± 4.2). Creatinine was abnormally high in 30 of 36 patients (83%) (range, 0.8 to 9.7; mean, 3.7 ± 2.2). SWI venous contrast correlated significantly with hemoglobin (r = 0.52, P = 0.0015), hematocrit (r = 0.65, P effect of blood transfusions in patients with HUS and neurological symptoms.

  16. Assessment of brain maturation in the preterm infants using diffusion tensor imaging (DTI) and enhanced T2 star weighted angiography (ESWAN)

    Energy Technology Data Exchange (ETDEWEB)

    Ling, Xueying, E-mail: lingxuey@163.com [Department of Medical Imaging Center, the First Affiliated Hospital, Jinan University, Guangzhou (China); Tang, Wen [Department of Medical Imaging Center, the First Affiliated Hospital, Jinan University, Guangzhou (China); Liu, Guosheng [Neonatal Intensive Care Unit, the First Affiliated Hospital, Jinan University, Guangzhou (China); Huang, Li [Department of Medical Imaging Center, the First Affiliated Hospital, Jinan University, Guangzhou (China); Li, Bingxiao [Neonatal Intensive Care Unit, the First Affiliated Hospital, Jinan University, Guangzhou (China); Li, Xiaofei; Liu, Sirun [Department of Medical Imaging Center, the First Affiliated Hospital, Jinan University, Guangzhou (China); Xu, Jing [Neonatal Intensive Care Unit, the First Affiliated Hospital, Jinan University, Guangzhou (China)

    2013-09-15

    Purpose: To assess the brain maturation of preterm infants using diffusion tensor imaging (DTI) and enhanced T2 star weighted angiography (ESWAN). Materials and methods: Conventional magnetic resonance imaging (MRI), DTI and ESWAN were performed in 60 preterm infants and 21 term controls. 60 preterm infants were subgrouped to two groups according to the age at imaging: before and at term-equivalent age (TEA). Fractional anisotropy (FA), apparent diffusion coefficient (ADC) map from DTI, T{sub 2}* and R{sub 2}* maps from ESWAN were post-processed at an off-line workstation. The values of FA, ADC, T{sub 2}* and R{sub 2}* from the posterior limb of internal capsule (PLIC), frontal white matter (FWM), occipital white matter (OWM) and lentiform nuclei (LN) were determined. These parameters were compared between preterm and term infants. Correlations of DTI and ESWAN parameters with the gestational age, postmenstrual age and postnatal age were analyzed. Results: ADCs of FWM, OWM and LN, and T{sub 2}* values of the PLIC and LN were higher in the preterm infants at TEA compared with the term controls. The correlations were existed between the postmenstrual age and the values of FA, ADC, T{sub 2}*, R{sub 2}* from the PLIC, values of ADC, T{sub 2}*, R{sub 2}* from the LN, T{sub 2}* value from the OWM. The correlations were also found between the postnatal age and the values of FA, ADC, T{sub 2}* from the PLIC, and T{sub 2}* value from the LN. Conclusion: The maturity of preterm brain around TEA was different from that of term controls and appeared to be independent of the prematurity at birth. T{sub 2}* was one of valuable indices to evaluate brain maturation in preterm infants.

  17. Assessment of brain maturation in the preterm infants using diffusion tensor imaging (DTI) and enhanced T2 star weighted angiography (ESWAN)

    International Nuclear Information System (INIS)

    Ling, Xueying; Tang, Wen; Liu, Guosheng; Huang, Li; Li, Bingxiao; Li, Xiaofei; Liu, Sirun; Xu, Jing

    2013-01-01

    Purpose: To assess the brain maturation of preterm infants using diffusion tensor imaging (DTI) and enhanced T2 star weighted angiography (ESWAN). Materials and methods: Conventional magnetic resonance imaging (MRI), DTI and ESWAN were performed in 60 preterm infants and 21 term controls. 60 preterm infants were subgrouped to two groups according to the age at imaging: before and at term-equivalent age (TEA). Fractional anisotropy (FA), apparent diffusion coefficient (ADC) map from DTI, T 2 * and R 2 * maps from ESWAN were post-processed at an off-line workstation. The values of FA, ADC, T 2 * and R 2 * from the posterior limb of internal capsule (PLIC), frontal white matter (FWM), occipital white matter (OWM) and lentiform nuclei (LN) were determined. These parameters were compared between preterm and term infants. Correlations of DTI and ESWAN parameters with the gestational age, postmenstrual age and postnatal age were analyzed. Results: ADCs of FWM, OWM and LN, and T 2 * values of the PLIC and LN were higher in the preterm infants at TEA compared with the term controls. The correlations were existed between the postmenstrual age and the values of FA, ADC, T 2 *, R 2 * from the PLIC, values of ADC, T 2 *, R 2 * from the LN, T 2 * value from the OWM. The correlations were also found between the postnatal age and the values of FA, ADC, T 2 * from the PLIC, and T 2 * value from the LN. Conclusion: The maturity of preterm brain around TEA was different from that of term controls and appeared to be independent of the prematurity at birth. T 2 * was one of valuable indices to evaluate brain maturation in preterm infants

  18. Coronary heart disease risk assessment and characterization of coronary artery disease using coronary CT angiography: comparison of asymptomatic and symptomatic groups

    International Nuclear Information System (INIS)

    Hwang, Y.; Kim, Y.; Chung, I.-M.; Ryu, J.; Park, H.

    2010-01-01

    Aim: To evaluate the prevalence of coronary artery disease (CAD) in relation to risk of coronary heart disease (CHD) and assess plaque characteristics from coronary computed tomography (CT) angiography in asymptomatic and symptomatic patients. Materials and methods: Three hundred and ninety consecutive patients [asymptomatic group, n = 138; symptomatic group (atypical or non-anginal chest pain), n = 252] were retrospectively enrolled. They were subsequently classified into three CHD risk categories, based on the National Cholesterol Education Program guidelines, and 10 year risks of coronary events were calculated using Framingham risk score. CT was evaluated for stenosis, plaque composition, and coronary calcium scores. Results: CAD was observed in 42% of the asymptomatic group and 62% of the symptomatic group. In the former, the prevalence of CAD in low-, moderate- and high-risk subgroups was 21.4, 47.4 and 65%, respectively, and was 33.3, 74.4, and 72.4% in the symptomatic group. Framingham 10-year risks of coronary events were significantly higher in patients with CAD than in normal participants, and receiver operating characteristics curves showed that discriminatory power was poor in the asymptomatic group and symptomatic men, and good in symptomatic women. Of the participants in the asymptomatic group, 12% exhibited only non-calcified plaques and of the symptomatic group, 7% exhibited only non-calcified plaques. The coronary calcium score was significantly higher for significant stenosis than for non-significant stenosis in both groups. Conclusions: The prevalence of CAD was not negligible even in subgroups with low-to-moderate CHD risk. Additionally, the Framingham risk score was effective for predicting CAD only in symptomatic women. Coronary calcium scores correlated with significant stenosis; however, a sizeable percentage of both groups had only non-calcified plaques.

  19. A quantitative assessment of Arctic shipping in 2010–2014

    KAUST Repository

    Eguíluz, Victor M.

    2016-08-01

    Rapid loss of sea ice is opening up the Arctic Ocean to shipping, a practice that is forecasted to increase rapidly by 2050 when many models predict that the Arctic Ocean will largely be free of ice toward the end of summer. These forecasts carry considerable uncertainty because Arctic shipping was previously considered too sparse to allow for adequate validation. Here, we provide quantitative evidence that the extent of Arctic shipping in the period 2011–2014 is already significant and that it is concentrated (i) in the Norwegian and Barents Seas, and (ii) predominantly accessed via the Northeast and Northwest Passages. Thick ice along the forecasted direct trans-Arctic route was still present in 2014, preventing transit. Although Arctic shipping remains constrained by the extent of ice coverage, during every September, this coverage is at a minimum, allowing the highest levels of shipping activity. Access to Arctic resources, particularly fisheries, is the most important driver of Arctic shipping thus far.

  20. Functional comparison between BuMA Supreme biodegradable polymer sirolimus-eluting and durable polymer zotarolimus-eluting coronary stents using Quantitative Flow Ratio: PIONEER QFR substudy

    NARCIS (Netherlands)

    Asano, Taku; Katagiri, Yuki; Collet, Carlos; Tenekecioglu, Erhan; Miyazaki, Yosuke; Sotomi, Yohei; Amoroso, Giovanni; Aminian, Adel; Brugaletta, Salvatore; Vrolix, Mathias; Hernandez-Antolín, Rosana; van de Harst, Pim; Iñiguez, Andres; Janssens, Luc; Smits, Pieter; Wykrzykowska, Joanna J.; Ribeiro, Vasco Gama; Periera, Helder; da Silva, Pedro Canas; Piek, Jan J.; Reiber, Johan H. C.; von Birgelen, Clemens; Sabaté, Manel; Onuma, Yoshinobu; Serruys, Patrick W.

    2017-01-01

    Quantitative Flow Ratio (QFR) based on 3-dimensional quantitative coronary angiography (3D-QCA) is a novel method to assess the physiological functionality after treatment with stents. The current study aimed to evaluate the difference in physiological functionality 9 months after implantation of a

  1. Endotyping early childhood asthma by quantitative symptom assessment

    DEFF Research Database (Denmark)

    Bisgaard, Hans; Pipper, Christian Bressen; Bønnelykke, Klaus

    2011-01-01

    Asthmatic symptoms in young children reflect a heterogeneous group of diseases. Symptoms remain the primary end-point in both research and clinical management, but there is a need for standardized symptom assessment....

  2. Quantitative Assessment of Orbital Implant Position - A Proof of Concept

    NARCIS (Netherlands)

    Schreurs, Ruud; Dubois, Leander; Becking, Alfred G.; Maal, Thomas J. J.

    2016-01-01

    Introduction In orbital reconstruction, the optimal location of a predefined implant can be planned preoperatively. Surgical results can be assessed intraoperatively or postoperatively. A novel method for quantifying orbital implant position is introduced. The method measures predictability of

  3. Quantitative assessment of orbital implant position - a proof of concept

    NARCIS (Netherlands)

    Schreurs, R.; Dubois, L.; Becking, A.G.; Maal, T.J.J.

    2016-01-01

    Introduction In orbital reconstruction, the optimal location of a predefined implant can be planned preoperatively. Surgical results can be assessed intraoperatively or postoperatively. A novel method for quantifying orbital implant position is introduced. The method measures predictability of

  4. Quantitative risk assessment: an emerging tool for emerging foodborne pathogens.

    OpenAIRE

    Lammerding, A. M.; Paoli, G. M.

    1997-01-01

    New challenges to the safety of the food supply require new strategies for evaluating and managing food safety risks. Changes in pathogens, food preparation, distribution, and consumption, and population immunity have the potential to adversely affect human health. Risk assessment offers a framework for predicting the impact of changes and trends on the provision of safe food. Risk assessment models facilitate the evaluation of active or passive changes in how foods are produced, processed, d...

  5. Normal values of left ventricularmass and cardiac chamber volumes assessed by 320-detector computed tomography angiography in the Copenhagen General Population Study

    DEFF Research Database (Denmark)

    Fuchs, Andreas; Mejdahl, Mads Rams; Kühl, J Tobias

    2016-01-01

    Aims Normal values of left ventricular mass (LVM) and cardiac chamber sizes are prerequisites for the diagnosis of individuals with heart disease. LVM and cardiac chamber sizes may be recorded during cardiac computed tomography angiography (CCTA), and thus modality specific normal values are need...

  6. Comparison of iodinated contrast media for the assessment of atherosclerotic plaque attenuation values by CT coronary angiography: Observations in an ex vivo model

    NARCIS (Netherlands)

    L. la Grutta (Ludovico); M. Galia (Massimo); G. Gentile; G. Lo Re (G.); E. Grassedonio (Emanuele); F. Coppolino; E. Maffei (Erica); E. Maresi (E.); A. Lo Casto (A.); F. Cademartiri (Filippo); M. Midiri (Massimo)

    2013-01-01

    textabstractObjective: To compare the influence of different iodinated contrast media with several dilutions on plaque attenuation in an ex vivo coronary model studied by multislice CT coronary angiography. Methods: In six ex vivo left anterior descending coronary arteries immersed in oil, CT

  7. Using integrated environmental modeling to automate a process-based Quantitative Microbial Risk Assessment

    Science.gov (United States)

    Integrated Environmental Modeling (IEM) organizes multidisciplinary knowledge that explains and predicts environmental-system response to stressors. A Quantitative Microbial Risk Assessment (QMRA) is an approach integrating a range of disparate data (fate/transport, exposure, an...

  8. Using Integrated Environmental Modeling to Automate a Process-Based Quantitative Microbial Risk Assessment (presentation)

    Science.gov (United States)

    Integrated Environmental Modeling (IEM) organizes multidisciplinary knowledge that explains and predicts environmental-system response to stressors. A Quantitative Microbial Risk Assessment (QMRA) is an approach integrating a range of disparate data (fate/transport, exposure, and...

  9. QUANTITATIVE DIFFERENCES IN ASSESSMENT OF HIGH SCHOOL FEMALE STUDENTS

    Directory of Open Access Journals (Sweden)

    Georgi Georgiev

    2011-08-01

    Full Text Available he research was carried out on 89 female students at first-year who regularly attended the course sport and sport activities. The aim was to see whether there are differences between the grades gained during the teaching and assessments received during the survey. As indicators in the evaluation of assessment during the research into account were taken techniques of performance of several sport disciplines: athletics (high start and gymnastics (rolling forward, from the sport games , basketball (leading the ball with a jump shot towards the basket and test - polygon for checking of the motor skills and habits of the female pupils. The determination of the significance of the differences was performed by t-test. After receiving the survey results, were identified statistically significant differences in the assessment of pupils.

  10. QUANTITATIVE ASSESSMENT OF CAMPYLOBACTER SPP. ON POULTRY CARCASSES

    Directory of Open Access Journals (Sweden)

    L. Alberghini

    2011-01-01

    Full Text Available Campylobacter spp. are bacterial pathogens associated with human gastroenteritis worldwide. In Europe, campylobacteriosis is one of the leading food-borne bacterial diseases and the consumption of poultry meats is suspected to be one of the major causes of illness. The aim of our research was to determine the number of Campylobacter spp. in poultry carcasses and in poultry meat samples during their storage till to retail markets. The study was conducted from February 2009 to February 2010 at slaughterhouse in Veneto region, followed by a test of fresh poultry meat placed on the market for sale. A total of 90 poultry carcass and 90 samples of poultry meat were examined. The quantitative examination resulted in Campylobacter spp. counts (mean: for carcasses between 2,0 ∙101 ufc/g and 1,5 ∙103 ufc/g (4,2 ∙102 and poultry meat between 2,0 ∙101 ufc/g and 3,7 ∙102 ufc/g (8,1 ∙101. The majority of isolates were classified as Campylobacter jejuni (58,3%, Campylobacter coli (22,9% or Arcobacter cryaerophilus (4,2%. Acknowledgments: The project was funded with grants from Fondazione Cariverona 2007.

  11. Quantitative accuracy assessment of thermalhydraulic code predictions with SARBM

    International Nuclear Information System (INIS)

    Prosek, A.

    2001-01-01

    In recent years, the nuclear reactor industry has focused significant attention on nuclear reactor systems code accuracy and uncertainty issues. A few methods suitable to quantify code accuracy of thermalhydraulic code calculations were proposed and applied in the past. In this study a Stochastic Approximation Ratio Based Method (SARBM) was adapted and proposed for accuracy quantification. The objective of the study was to qualify the SARBM. The study compare the accuracy obtained by SARBM with the results obtained by widely used Fast Fourier Transform Based Method (FFTBM). The methods were applied to RELAP5/MOD3.2 code calculations of various BETHSY experiments. The obtained results showed that the SARBM was able to satisfactorily predict the accuracy of the calculated trends when visually comparing plots and comparing the results with the qualified FFTBM. The analysis also showed that the new figure-of-merit called accuracy factor (AF) is more convenient than stochastic approximation ratio for combining single variable accuracy's into total accuracy. The accuracy results obtained for the selected tests suggest that the acceptability factors for the SAR method were reasonably defined. The results also indicate that AF is a useful quantitative measure of accuracy.(author)

  12. A quantitative framework for assessing spatial flows of ecosystem services

    NARCIS (Netherlands)

    Serna-Chavez, H.M.; Schulp, C.J.E.; van Bodegom, P.M.; Bouten, W.; Verburg, P.H.; Davidson, M.D.

    2014-01-01

    Spatial disconnections between locations where ecosystem services are produced and where they are used are common. To date most ecosystem service assessments have relied on static indicators of provision and often do not incorporate relations with the corresponding beneficiaries or benefiting areas.

  13. Quantitative assessment of calf circumference in Duchenne muscular dystrophy patients

    NARCIS (Netherlands)

    Beenakker, EAC; de Vries, Joeke; Fock, JM; van Tol, M; Brouwer, OF; Maurits, NM; van der Hoeven, JH

    2002-01-01

    Duchenne muscular dystrophy is clinically characterised by progressive muscle weakness and a gradual increase in the size of some affected muscles, especially calf muscles. The extent of calf enlargement is usually determined by subjective visual assessment. The purpose of this study was to

  14. Real-time PCR quantitative assessment of hepatitis A virus ...

    African Journals Online (AJOL)

    We applied real-time RT-PCR (reverse transcription-polymerase chain reaction) to assess the incidence of hepatitis A virus, rotaviruses and enteroviruses in the Tyume River, an important water resource in the impoverished Eastern Cape Province of South Africa. Detection of noroviruses was done using conventional ...

  15. Developing a Quantitative Tool for Sustainability Assessment of HEIs

    Science.gov (United States)

    Waheed, Bushra; Khan, Faisal I.; Veitch, Brian

    2011-01-01

    Purpose: Implementation of a sustainability paradigm demands new choices and innovative ways of thinking. The main objective of this paper is to provide a meaningful sustainability assessment tool for make informed decisions, which is applied to higher education institutions (HEIs). Design/methodology/approach: The objective is achieved by…

  16. Groundwater quantitative status assessment for River Basin Management Plan 2015-2021 in Slovenia

    Directory of Open Access Journals (Sweden)

    Mišo Andjelov

    2016-12-01

    Full Text Available The improved methodological approach of the groundwater quantitative status assessment in Slovenia and the results of the assessment period 2010-2013, taking into account the new reference thirty-year period 1981- 2010, are presented. Within the assessment period quantitative status in all shallow alluvial aquifers of 21 groundwater bodies in Slovenia is assessed as good, with a medium to high level of confience. Groundwater quantitative status assessment methodology considers the processes of the whole hydrological cycle and the results of groundwater recharge modelling. The methodology incorporates the concept of sustainable groundwater use to preserve the quantities not causing environmental and other harm (unacceptable environmental and other consequences. Legislative baseline for assessing the impacts of groundwater abstraction on renewable and available quantities of groundwater introduces new methodology by abandoning obsolete mining concept of "calculation of groundwater reserves".

  17. Angiography in distal spleno-renal shunts

    International Nuclear Information System (INIS)

    Wittrich, G.; Czembirek, H.; Appel, W.; Funovics, J.; Lechner, G.; Vienna Univ.; Vienna Univ.

    1980-01-01

    The conception of Warren's Shunt - selective decompression of esophageal varices while maintaining prograde portal flow - was controlled by pre- and postoperative angiographic examinations on 12 patients: No change in portal perfusion was established angiographically in ten of the patients. Two patients developed aneurysmatic, arterio-portal fistulae as a result of postoperative portal decompression. In one of these cases, a thrombosis of the portal vein with hepatofugal perfusion of the left gastric vein was detected. The postoperative examinations indicated functioning shunts in 9 out of 12 patients. These results formed the basis for the discussion regarding the value of visceral angiography in the selection of the surgical technique and regarding its value in control of therapy. Surgical questions concerning the visceral vascular anatomy can be answered sufficiently. Furthermore, celiac and mesenteric angiography yield information on portal hemodynamics. Nevertheless, the additional application of invasive scintigraphy seems to be necessary for establishing quantitative radiological parameters of prognostic relevance. (orig.) [de

  18. Angiography in distal spleno-renal shunts

    Energy Technology Data Exchange (ETDEWEB)

    Wittrich, G.; Czembirek, H.; Appel, W.; Funovics, J.; Lechner, G.

    1980-11-01

    The conception of Warren's Shunt - selective decompression of esophageal varices while maintaining prograde portal flow - was controlled by pre- and postoperative angiographic examinations on 12 patients: No change in portal perfusion was established angiographically in ten of the patients. Two patients developed aneurysmatic, arterio-portal fistulae as a result of postoperative portal decompression. In one of these cases, a thrombosis of the portal vein with hepatofugal perfusion of the left gastric vein was detected. The postoperative examinations indicated functioning shunts in 9 out of 12 patients. These results formed the basis for the discussion regarding the value of visceral angiography in the selection of the surgical technique and regarding its value in control of therapy. Surgical questions concerning the visceral vascular anatomy can be answered sufficiently. Furthermore, celiac and mesenteric angiography yield information on portal hemodynamics. Nevertheless, the additional application of invasive scintigraphy seems to be necessary for establishing quantitative radiological parameters of prognostic relevance.

  19. Intravenous spiral CT angiography for assessment before orthotopic liver transplantation: Comparison between tomography, MIP, 3-dimensional surface imaging and intraarterial DSA; Intravenoese Spiral-CT-Angiographie zur Evaluation vor orthotoper Lebertransplantation: Vergleiche zwischen Schnittbilddarstellung, MIP, dreidimensionaler Oberflaechendarstellung und intraarterieller DSA

    Energy Technology Data Exchange (ETDEWEB)

    Hidajat, N. [Medizinische Fakultaet der Humboldt-Univ., Berlin (Germany). Strahlenklinik und Poliklinik; Vogl, T.J. [Medizinische Fakultaet der Humboldt-Univ., Berlin (Germany). Strahlenklinik und Poliklinik; Moeller, M. [Medizinische Fakultaet der Humboldt-Univ., Berlin (Germany). Strahlenklinik und Poliklinik; Bechstein, W.O. [Medizinische Fakultaet der Humboldt-Univ., Berlin (Germany). Klinik und Poliklinik fuer Allgemein- und Transplantationschirurgie; Felix, R. [Medizinische Fakultaet der Humboldt-Univ., Berlin (Germany). Strahlenklinik und Poliklinik

    1996-11-01

    Purpose: To analyse the efficacy of intravenous spiral CT angiography (SCTA) for the evaluation before orthotopic liver transplantation (oLT) compared with DSA. Methods: Spiral CT was performed on 31 potential recipients of a liver graft in order to examine hepatic vessels, coeliac axis, splenic artery and superior mesenteric artery. The arterial vessels were reconstructed in `Maximum Intensity Projection (MIP)` and `Shaded Surface Display (SSD)`-technique. The axial images, MIP and SSD were compared in 25 patients with DSA with regard to the visualisation of the vascular anatomy, detectability of stenosis and vascular diameters. Results: The type of arterial liver supply could be determined via SCTA in all patients. Stenosis of the coeliac axis was seen in ten patients on the DSA, MIP and SSD and in eight patients on the axial images. Occlusion of the hepatic artery was clearly visualised in two patients on the DSA, axial images and MIP and in one patient on the SSD. There was no false positive diagnosis with SCTA. SSD was seen as the best technique to visualise the vessels without overshadowing. There were no significant differences between the diamters measured from the axial images, MIP and SSD images in transversal direction and the DSA images (p>0.05). Conclusion: SCTA is a greatly promising method for the imaging of vessels supplying the liver before oLT, and may convey more diagnostic information than DSA. (orig.) [Deutsch] Ziel: Bewertung der Einsetzbarkeit in intravenoesen Spiral-CT-Angiographie (SCTA) zur Evaluation vor orthotoper Lebertransplantation (oLT) im Vergleich zur DSA. Methoden: Es wurde bei 31 Patienten vor moeglicher oLT eine SCTA der Lebergefaesse einschliesslich des Truncus coeliacus, der A. lienalis und A. mesenterica superior durchgefuehrt. Die arteriellen Gefaesse wurden mittels `Maximum-Intensitaets-Projektion (MIP)`- und `Oberflaechenschattierungs(SSD)`-Technik rekonstruiert. Die Schnittbilder, MIP und SSD, wurden bei 25 Patienten

  20. Floods characterization: from impact data to quantitative assessment

    Science.gov (United States)

    Llasat, Maria-Carmen; Gilabert, Joan; Llasat-Botija, Montserrat; Marcos, Raül; Quintana-Seguí, Pere; Turco, Marco

    2015-04-01

    This study is based on the following flood databases from Catalonia: INUNGAMA (1900-2010) which considers 372 floods (Llasat et al, 2014), PRESSGAMA (1981-2010) and HISTOGAMA (from XIV Century on) - built as part of SPHERE project and recently updated. These databases store information about flood impacts (among others) and classify them by their severity (catastrophic, extraordinary and ordinary) by means of an indicators matrix based on other studies (i.e. Petrucci et al, 2013; Llasat et al, 2013). On this research we present a comparison between flood impacts, flow data and rainfall data on a Catalan scale and particularly for the basins of Segre, Muga, Ter and Llobregat (Western Mediterranean). From a bottom-up approach, a statistical methodology has been built (trend analysis, measures of position, cumulative distribution functions and geostatistics) in order to identify quantitative thresholds that will make possible to classify the floods. The purpose of this study is to establish generic thresholds for the whole Catalan region, for this we have selected rainfall maximums of flooding episodes stored at INUNGAMA and they have been related to flood categories by boxplot diagrams. Regarding the stream flow, we have established a relation between impacts and return periods at the day when the flow is maximum. The aim is to homogenize and compare the different drainage basins and to obtain general thresholds. It is also presented detailed analyses of relations between flooding episodes, flood classification and weather typing schemes - based in Jenkinson and Collison classification (applied to the Iberian Peninsula by Spellmann, 2000). In this way it could be analyzed whether patterns for the different types of floods exist or not. Finally, this work has pointed out the need of defining a new category for the most severe episodes.

  1. Cerebral Blood Volume ASPECTS Is the Best Predictor of Clinical Outcome in Acute Ischemic Stroke: A Retrospective, Combined Semi-Quantitative and Quantitative Assessment.

    Directory of Open Access Journals (Sweden)

    Marina Padroni

    Full Text Available The capability of CT perfusion (CTP Alberta Stroke Program Early CT Score (ASPECTS to predict outcome and identify ischemia severity in acute ischemic stroke (AIS patients is still questioned.62 patients with AIS were imaged within 8 hours of symptom onset by non-contrast CT, CT angiography and CTP scans at admission and 24 hours. CTP ASPECTS was calculated on the affected hemisphere using cerebral blood flow (CBF, cerebral blood volume (CBV and mean transit time (MTT maps by subtracting 1 point for any abnormalities visually detected or measured within multiple cortical circular regions of interest according to previously established thresholds. MTT-CBV ASPECTS was considered as CTP ASPECTS mismatch. Hemorrhagic transformation (HT, recanalization status and reperfusion grade at 24 hours, final infarct volume at 7 days and modified Rankin scale (mRS at 3 months after onset were recorded.Semi-quantitative and quantitative CTP ASPECTS were highly correlated (p<0.00001. CBF, CBV and MTT ASPECTS were higher in patients with no HT and mRS ≤ 2 and inversely associated with final infarct volume and mRS (p values: from p<0.05 to p<0.00001. CTP ASPECTS mismatch was slightly associated with radiological and clinical outcomes (p values: from p<0.05 to p<0.02 only if evaluated quantitatively. A CBV ASPECTS of 9 was the optimal semi-quantitative value for predicting outcome.Our findings suggest that visual inspection of CTP ASPECTS recognizes infarct and ischemic absolute values. Semi-quantitative CBV ASPECTS, but not CTP ASPECTS mismatch, represents a strong prognostic indicator, implying that core extent is the main determinant of outcome, irrespective of penumbra size.

  2. Computed tomography angiography in the investigation of carotid stenosis

    Energy Technology Data Exchange (ETDEWEB)

    Goddard, A.J.P.; Mendelow, A.D.; Birchall, D

    2001-07-01

    The assessment of carotid atherosclerotic disease is an essential pre-requisite for determining a patients suitability for carotid endarterectomy to prevent ischaemic stroke. Catheter angiography is regarded as the most accurate investigative tool for this purpose. However, with its finite morbidity and invasiveness, there is an increasing reliance upon non-invasive methods to accurately assess carotid disease. We present a review of the technique and applications of computed tomography angiography. Goddard, A.J. P.et al. (2001)

  3. A quantitative framework for assessing spatial flows of ecosystem services

    OpenAIRE

    Serna Chavez, H.M.; Schulp, C.J.E.; van Bodegom, P.M.; Bouten, W.; Verburg, P.H.; Davidson, M.D.

    2014-01-01

    Spatial disconnections between locations where ecosystem services are produced and where they are used are common. To date most ecosystem service assessments have relied on static indicators of provision and often do not incorporate relations with the corresponding beneficiaries or benefiting areas. Most studies implicitly assume spatial and temporal connections between ecosystem service provision and beneficiaries, while the actual connections, i.e., ecosystem service flows, are poorly under...

  4. A Review of Quantitative Situation Assessment Models for Nuclear Power Plant Operators

    International Nuclear Information System (INIS)

    Lee, Hyun Chul; Seong, Poong Hyun

    2009-01-01

    Situation assessment is the process of developing situation awareness and situation awareness is defined as 'the perception of the elements in the environment within a volume of time and space, the comprehension of their meaning and the projection of their status in the near future.' Situation awareness is an important element influencing human actions because human decision making is based on the result of situation assessment or situation awareness. There are many models for situation awareness and those models can be categorized into qualitative or quantitative. As the effects of some input factors on situation awareness can be investigated through the quantitative models, the quantitative models are more useful for the design of operator interfaces, automation strategies, training program, and so on, than the qualitative models. This study presents the review of two quantitative models of situation assessment (SA) for nuclear power plant operators

  5. Quantitative Assessment of Myocardial Infarction by In-111 Antimyosin Antibody

    International Nuclear Information System (INIS)

    Lee, Myung Chul; Lee, Kyung Han; Choi, Yoon Ho; Chung, June Key; Park, Young Bae; Koh, Chang Soon; Moon, Dae Hyuk

    1991-01-01

    Infarct size is a major determinant of prognosis after acute myocardial infarction. Up to date, however, clinically available tests to estimate this size have not been sufficiently accurate. Twelve lead electrocardiogram and wall motion abnormality measurement are not quantitative, and creatine phosphokinase (CPK) measurement is inaccurate in the presence of reperfusion or right ventricular infarction. Methods have been developed to localize and size acute myocardial infarcts with agents that are selectively sequestered in areas of myocardial damage, but previously used agents have lacked sufficient specificity. Antibodies that bind specifically only to damaged myocardial cells may resolve this problem and provide an accurate method for noninvasively measuring infarct size. We determined the accuracy with which infarcted myocardial mass can be measured using single photon emission computed tomography (SPECT) and radiolabeled antimyosin antibodies. Seven patients with acute myocardial infarction and one stable angina patient were injected with 2 mCi of Indium-111 labeled antimyosin antibodies. Planar image and SPECT was performed 24 hours later. None of the patients had history of prior infarcts, and none had undergone reperfusion techniques prior to the study, which was done within 4 days of the attack. Planar image showed all infarct patients to have positive uptakes in the cardiac region. The location of this uptake correlated to the infarct site as indicated by electrocardiography in most of the cases. The angina patient, however, showed no such abnormal uptake. Infarct size was determined from transverse slices of the SPECT image using a 45% threshold value obtained from a phantom study. Measured infarct size ranged from 40 to 192 gr. There was significant correlation between the infarct size measured by SPECT and that estimated from serial measurements of CPK (r=0.73, p<0,05). These date suggest that acute myocardial infarct size can be accurately measured

  6. Quantitative assessment of workload and stressors in clinical radiation oncology.

    Science.gov (United States)

    Mazur, Lukasz M; Mosaly, Prithima R; Jackson, Marianne; Chang, Sha X; Burkhardt, Katharin Deschesne; Adams, Robert D; Jones, Ellen L; Hoyle, Lesley; Xu, Jing; Rockwell, John; Marks, Lawrence B

    2012-08-01

    Workload level and sources of stressors have been implicated as sources of error in multiple settings. We assessed workload levels and sources of stressors among radiation oncology professionals. Furthermore, we explored the potential association between workload and the frequency of reported radiotherapy incidents by the World Health Organization (WHO). Data collection was aimed at various tasks performed by 21 study participants from different radiation oncology professional subgroups (simulation therapists, radiation therapists, physicists, dosimetrists, and physicians). Workload was assessed using National Aeronautics and Space Administration Task-Load Index (NASA TLX). Sources of stressors were quantified using observational methods and segregated using a standard taxonomy. Comparisons between professional subgroups and tasks were made using analysis of variance ANOVA, multivariate ANOVA, and Duncan test. An association between workload levels (NASA TLX) and the frequency of radiotherapy incidents (WHO incidents) was explored (Pearson correlation test). A total of 173 workload assessments were obtained. Overall, simulation therapists had relatively low workloads (NASA TLX range, 30-36), and physicists had relatively high workloads (NASA TLX range, 51-63). NASA TLX scores for physicians, radiation therapists, and dosimetrists ranged from 40-52. There was marked intertask/professional subgroup variation (Passociation between workload and frequency of reported radiotherapy incidents by the WHO was found (r = 0.87, P value=.045). Workload level and sources of stressors vary among professional subgroups. Understanding the factors that influence these findings can guide adjustments to the workflow procedures, physical layout, and/or communication protocols to enhance safety. Additional evaluations are needed in order to better understand if these findings are systemic. Copyright © 2012 Elsevier Inc. All rights reserved.

  7. Aliasing as noise - A quantitative and qualitative assessment

    Science.gov (United States)

    Park, Stephen K.; Hazra, Rajeeb

    1993-01-01

    We present a model-based argument that, for the purposes of system design and digital image processing, aliasing should be treated as signal-dependent additive noise. By using a computational simulation based on this model, we process (high resolution images of) natural scenes in a way which enables the 'aliased component' of the reconstructed image to be isolated unambiguously. We demonstrate that our model-based argument leads naturally to system design metrics which quantify the extent of aliasing. And, by illustrating several aliased component images, we provide a qualitative assessment of aliasing as noise.

  8. Stereotactic radiosurgery for brain arteriovenous malformations: quantitative MR assessment of nidal response at 1 year and angiographic factors predicting early obliteration

    Energy Technology Data Exchange (ETDEWEB)

    Nagaraja, S.; Lee, K.J.; Capener, D.; Wilkinson, I.D.; Griffiths, P.D. [Royal Hallamshire Hospital, Section of Academic Radiology, University of Sheffield, Sheffield (United Kingdom); Coley, S.C. [Royal Hallamshire Hospital, Department of Neuroradiology, Sheffield (United Kingdom); Walton, L.; Kemeny, A.A. [Royal Hallamshire Hospital, National Centre for Stereotactic Radiosurgery, Sheffield (United Kingdom)

    2006-11-15

    We investigated the role of magnetic resonance angiography (MRA) in the early follow-up of patients after stereotactic radiosurgery (STRS) for cerebral arteriovenous malformations (AVMs) and determined the influence of individual morphological factors of AVMs in early response to treatment. A group of 40 patients (41 AVMs) consented to a dedicated 1.5-T MR protocol 12 months after receiving STRS for a brain AVM. In addition to standard spin echo sequences, 3-D contrast-enhanced sliding interleaved Ky MRA (CE-SLINKY) and dynamic time-resolved subtraction angiography (MR-DSA) were performed. Nidal volumes were calculated using CE-SLINKY data in patients with a persisting arteriovenous shunt. Planning angiographic data was investigated in all 40 patients. The following AVM factors were used in the statistical analysis to determine their role in nidus obliteration: (1) maximum linear dimension, (2) nidal volume, (3) AVM location (4) nidal morphology, (5) venous drainage, (6) ''high-flow angiographic change'', (7) prior embolization, and (8) dose reduction. Complete nidal obliteration was found in 9 patients, 26 showed greater than 50% nidal reduction and 6 had less than 50%. Two AVM factors, venous drainage and AVM location, were found to significantly correlate with rate of obliteration. We successfully demonstrated the use of MRA to quantitatively assess the response of AVMs to STRS. Two AVM factors, venous drainage and AVM location were found to correlate with rate of obliteration prior to the application of the Bonferroni correction, but if this more rigorous statistical test was applied then none of the factors was found to be significant. (orig.)

  9. Stereotactic radiosurgery for brain arteriovenous malformations: quantitative MR assessment of nidal response at 1 year and angiographic factors predicting early obliteration.

    Science.gov (United States)

    Nagaraja, S; Lee, K J; Coley, S C; Capener, D; Walton, L; Kemeny, A A; Wilkinson, I D; Griffiths, P D

    2006-11-01

    We investigated the role of magnetic resonance angiography (MRA) in the early follow-up of patients after stereotactic radiosurgery (STRS) for cerebral arteriovenous malformations (AVMs) and determined the influence of individual morphological factors of AVMs in early response to treatment. A group of 40 patients (41 AVMs) consented to a dedicated 1.5-T MR protocol 12 months after receiving STRS for a brain AVM. In addition to standard spin echo sequences, 3-D contrast-enhanced sliding interleaved Ky MRA (CE-SLINKY) and dynamic time-resolved subtraction angiography (MR-DSA) were performed. Nidal volumes were calculated using CE-SLINKY data in patients with a persisting arteriovenous shunt. Planning angiographic data was investigated in all 40 patients. The following AVM factors were used in the statistical analysis to determine their role in nidus obliteration: (1) maximum linear dimension, (2) nidal volume, (3) AVM location (4) nidal morphology, (5) venous drainage, (6) "high-flow angiographic change", (7) prior embolization, and (8) dose reduction. Complete nidal obliteration was found in 9 patients, 26 showed greater than 50% nidal reduction and 6 had less than 50%. Two AVM factors, venous drainage and AVM location, were found to significantly correlate with rate of obliteration. We successfully demonstrated the use of MRA to quantitatively assess the response of AVMs to STRS. Two AVM factors, venous drainage and AVM location were found to correlate with rate of obliteration prior to the application of the Bonferroni correction, but if this more rigorous statistical test was applied then none of the factors was found to be significant.

  10. Stereotactic radiosurgery for brain arteriovenous malformations: quantitative MR assessment of nidal response at 1 year and angiographic factors predicting early obliteration

    International Nuclear Information System (INIS)

    Nagaraja, S.; Lee, K.J.; Capener, D.; Wilkinson, I.D.; Griffiths, P.D.; Coley, S.C.; Walton, L.; Kemeny, A.A.

    2006-01-01

    We investigated the role of magnetic resonance angiography (MRA) in the early follow-up of patients after stereotactic radiosurgery (STRS) for cerebral arteriovenous malformations (AVMs) and determined the influence of individual morphological factors of AVMs in early response to treatment. A group of 40 patients (41 AVMs) consented to a dedicated 1.5-T MR protocol 12 months after receiving STRS for a brain AVM. In addition to standard spin echo sequences, 3-D contrast-enhanced sliding interleaved Ky MRA (CE-SLINKY) and dynamic time-resolved subtraction angiography (MR-DSA) were performed. Nidal volumes were calculated using CE-SLINKY data in patients with a persisting arteriovenous shunt. Planning angiographic data was investigated in all 40 patients. The following AVM factors were used in the statistical analysis to determine their role in nidus obliteration: (1) maximum linear dimension, (2) nidal volume, (3) AVM location (4) nidal morphology, (5) venous drainage, (6) ''high-flow angiographic change'', (7) prior embolization, and (8) dose reduction. Complete nidal obliteration was found in 9 patients, 26 showed greater than 50% nidal reduction and 6 had less than 50%. Two AVM factors, venous drainage and AVM location, were found to significantly correlate with rate of obliteration. We successfully demonstrated the use of MRA to quantitatively assess the response of AVMs to STRS. Two AVM factors, venous drainage and AVM location were found to correlate with rate of obliteration prior to the application of the Bonferroni correction, but if this more rigorous statistical test was applied then none of the factors was found to be significant. (orig.)

  11. Visual and quantitative assessment of lateral lumbar spinal canal stenosis with magnetic resonance imaging

    International Nuclear Information System (INIS)

    Sipola, Petri; Vanninen, Ritva; Manninen, Hannu; Leinonen, Ville; Niemelaeinen, Riikka; Aalto, Timo; Airaksinen, Olavi; Battie, Michele C.

    2011-01-01

    Background. Lateral lumbar spinal canal stenosis is a common etiology of lumbar radicular symptoms. Quantitative measurements have commonly demonstrated better repeatability than visual assessments. We are not aware of any studies examining the repeatability of quantitative assessment of the lateral canal. Purpose. To evaluate the repeatability of visual assessments and newly developed quantitative measurements of lateral lumbar spinal canal stenosis using magnetic resonance imaging (MRI). Material and Methods. Twenty-eight patients with lateral lumbar spinal canal stenosis or prior spinal surgery with recurrent symptoms were imaged with MRI. A radiologist, a neurosurgeon and a spine research trainee graded visually and quantitatively subarticular (n = 188) and foraminal zones (n = 260) of the lateral spinal canal. Quantitative measurements included the minimal subarticular width and the cross-sectional area of the foramen. Results. The repeatability of visual assessment at the subarticular zone and foraminal zones between raters varied from 0.45-0.59 and 0.42-0.53, respectively. Similarly, the intraclass correlation coefficients for the quantitative measurements varied from 0.67-0.71 and 0.66-0.76, respectively. The intra-rater repeatability for the visual assessments of the subarticular and foraminal zones was 0.70 and 0.62, respectively, while the corresponding intraclass correlation coefficients for quantitative measurements were 0.83 and 0.81, respectively. Conclusion. Inter-rater repeatability of visual assessments of lateral stenosis is moderate, whereas quantitative measurements of both subarticular width and the cross-sectional area of the foramen have substantial reproducibility and may be particularly useful for longitudinal studies and research purposes. The clinical value of these parameters requires further study

  12. New Trends in Quantitative Assessment of the Corneal Barrier Function

    Directory of Open Access Journals (Sweden)

    Anton Guimerà

    2014-05-01

    Full Text Available The cornea is a very particular tissue due to its transparency and its barrier function as it has to resist against the daily insults of the external environment. In addition, maintenance of this barrier function is of crucial importance to ensure a correct corneal homeostasis. Here, the corneal epithelial permeability has been assessed in vivo by means of non-invasive tetrapolar impedance measurements, taking advantage of the huge impact of the ion fluxes in the passive electrical properties of living tissues. This has been possible by using a flexible sensor based in SU-8 photoresist. In this work, a further analysis focused on the validation of the presented sensor is performed by monitoring the healing process of corneas that were previously wounded. The obtained impedance measurements have been compared with the damaged area observed in corneal fluorescein staining images. The successful results confirm the feasibility of this novel method, as it represents a more sensitive in vivo and non-invasive test to assess low alterations of the epithelial permeability. Then, it could be used as an excellent complement to the fluorescein staining image evaluation.

  13. Quantitative Assessment of Workload and Stressors in Clinical Radiation Oncology

    International Nuclear Information System (INIS)

    Mazur, Lukasz M.; Mosaly, Prithima R.; Jackson, Marianne; Chang, Sha X.; Burkhardt, Katharin Deschesne; Adams, Robert D.; Jones, Ellen L.; Hoyle, Lesley; Xu, Jing; Rockwell, John; Marks, Lawrence B.

    2012-01-01

    Purpose: Workload level and sources of stressors have been implicated as sources of error in multiple settings. We assessed workload levels and sources of stressors among radiation oncology professionals. Furthermore, we explored the potential association between workload and the frequency of reported radiotherapy incidents by the World Health Organization (WHO). Methods and Materials: Data collection was aimed at various tasks performed by 21 study participants from different radiation oncology professional subgroups (simulation therapists, radiation therapists, physicists, dosimetrists, and physicians). Workload was assessed using National Aeronautics and Space Administration Task-Load Index (NASA TLX). Sources of stressors were quantified using observational methods and segregated using a standard taxonomy. Comparisons between professional subgroups and tasks were made using analysis of variance ANOVA, multivariate ANOVA, and Duncan test. An association between workload levels (NASA TLX) and the frequency of radiotherapy incidents (WHO incidents) was explored (Pearson correlation test). Results: A total of 173 workload assessments were obtained. Overall, simulation therapists had relatively low workloads (NASA TLX range, 30-36), and physicists had relatively high workloads (NASA TLX range, 51-63). NASA TLX scores for physicians, radiation therapists, and dosimetrists ranged from 40-52. There was marked intertask/professional subgroup variation (P<.0001). Mental demand (P<.001), physical demand (P=.001), and effort (P=.006) significantly differed among professional subgroups. Typically, there were 3-5 stressors per cycle of analyzed tasks with the following distribution: interruptions (41.4%), time factors (17%), technical factors (13.6%), teamwork issues (11.6%), patient factors (9.0%), and environmental factors (7.4%). A positive association between workload and frequency of reported radiotherapy incidents by the WHO was found (r = 0.87, P value=.045

  14. Quantitative Assessment of Workload and Stressors in Clinical Radiation Oncology

    Energy Technology Data Exchange (ETDEWEB)

    Mazur, Lukasz M., E-mail: lukasz_mazur@ncsu.edu [Department of Radiation Oncology, University of North Carolina, Chapel Hill, North Carolina (United States); Industrial Extension Service, North Carolina State University, Raleigh, North Carolina (United States); Biomedical Engineering, North Carolina State University, Raleigh, North Carolina (United States); Mosaly, Prithima R. [Industrial Extension Service, North Carolina State University, Raleigh, North Carolina (United States); Jackson, Marianne; Chang, Sha X.; Burkhardt, Katharin Deschesne; Adams, Robert D.; Jones, Ellen L.; Hoyle, Lesley [Department of Radiation Oncology, University of North Carolina, Chapel Hill, North Carolina (United States); Xu, Jing [Industrial Extension Service, North Carolina State University, Raleigh, North Carolina (United States); Rockwell, John; Marks, Lawrence B. [Department of Radiation Oncology, University of North Carolina, Chapel Hill, North Carolina (United States)

    2012-08-01

    Purpose: Workload level and sources of stressors have been implicated as sources of error in multiple settings. We assessed workload levels and sources of stressors among radiation oncology professionals. Furthermore, we explored the potential association between workload and the frequency of reported radiotherapy incidents by the World Health Organization (WHO). Methods and Materials: Data collection was aimed at various tasks performed by 21 study participants from different radiation oncology professional subgroups (simulation therapists, radiation therapists, physicists, dosimetrists, and physicians). Workload was assessed using National Aeronautics and Space Administration Task-Load Index (NASA TLX). Sources of stressors were quantified using observational methods and segregated using a standard taxonomy. Comparisons between professional subgroups and tasks were made using analysis of variance ANOVA, multivariate ANOVA, and Duncan test. An association between workload levels (NASA TLX) and the frequency of radiotherapy incidents (WHO incidents) was explored (Pearson correlation test). Results: A total of 173 workload assessments were obtained. Overall, simulation therapists had relatively low workloads (NASA TLX range, 30-36), and physicists had relatively high workloads (NASA TLX range, 51-63). NASA TLX scores for physicians, radiation therapists, and dosimetrists ranged from 40-52. There was marked intertask/professional subgroup variation (P<.0001). Mental demand (P<.001), physical demand (P=.001), and effort (P=.006) significantly differed among professional subgroups. Typically, there were 3-5 stressors per cycle of analyzed tasks with the following distribution: interruptions (41.4%), time factors (17%), technical factors (13.6%), teamwork issues (11.6%), patient factors (9.0%), and environmental factors (7.4%). A positive association between workload and frequency of reported radiotherapy incidents by the WHO was found (r = 0.87, P value=.045

  15. Assessment of the left ventricular systolic and diastolic function by the left ventricular density curve derived from intravenous digital subtraction angiography in children

    Energy Technology Data Exchange (ETDEWEB)

    Horigome, Hitoshi; Satoh, Hideo; Isobe, Takeshi; Takita, Hitoshi (Tsukuba Univ., Ibaraki (Japan). Inst. of Clinical Medicine)

    1991-05-01

    To evaluate the left ventricular (LV) systolic and diastolic function, fifty-four children with various heart diseases underwent intravenous digital subtraction angiography (IV-DSA). Global left ventricular density curve was obtained through densitometry of the DSA images. The curve was smoothed by a third-degree Fourier transformation and systolic and diastolic indexes were obtained. In the control group, consisting of Kawasaki disease without coronary lesion and mild pulmonary stenosis, the peak ejection rate (PER) and the peak filling rate in early diastole (PFR-E) correlated positively with the heart rate (HR) in a quadratic curve manner (PER: r= 0.93 p<0.01, PFR-E: r= 0.94 p<0.01). Time from end-diastolic to PER (T-PER) and time from end-systolic to PFR (T-PFR) were correlated negatively with HR (T-PER: r=-0.86 p<0.01, T-PFR: r=-0.91 p<0.01). However, T-PER/RR and T-PFR/RR values were rather constant (20.9+-3.2%, 17.0+-2.6%, respectively). We also found significant correlations of PER and PFR-E with left ventricular ejection fraction (LVEF). Patients with corrected tetralogy of Fallot and with cardiomyopaties showed not only abnormal systolic indexes but some depressed diastolic indexes. LV density curve also disclosed isolated diastolic dysfunction in a group of aortic stenosis and in two patients with coronary lesions. A correlation of LVEF derived from the density curve and conventional area-length method was high (r= 0.91 p<0.001). To evaluate the reproducibility, we were able to obtain the digital data twice with over one month interval on 24 patients. The intraobserver correlation was satisfactory. We applied the remasking method, resulting in improving the quality of digital images under spontaneous breathing. Our results indicated that IV-DSA was a less-invasive and clinically reliable method for assessment of LV function in children. (author).

  16. Assessment of the left ventricular systolic and diastolic function by the left ventricular density curve derived from intravenous digital subtraction angiography in children

    International Nuclear Information System (INIS)

    Horigome, Hitoshi; Satoh, Hideo; Isobe, Takeshi; Takita, Hitoshi

    1991-01-01

    To evaluate the left ventricular (LV) systolic and diastolic function, fifty-four children with various heart diseases underwent intravenous digital subtraction angiography (IV-DSA). Global left ventricular density curve was obtained through densitometry of the DSA images. The curve was smoothed by a third-degree Fourier transformation and systolic and diastolic indexes were obtained. In the control group, consisting of Kawasaki disease without coronary lesion and mild pulmonary stenosis, the peak ejection rate (PER) and the peak filling rate in early diastole (PFR-E) correlated positively with the heart rate (HR) in a quadratic curve manner [PER: r= 0.93 p<0.01, PFR-E: r= 0.94 p<0.01]. Time from end-diastolic to PER (T-PER) and time from end-systolic to PFR (T-PFR) were correlated negatively with HR [T-PER: r=-0.86 p<0.01, T-PFR: r=-0.91 p<0.01]. However, T-PER/RR and T-PFR/RR values were rather constant (20.9±3.2%, 17.0±2.6%, respectively). We also found significant correlations of PER and PFR-E with left ventricular ejection fraction (LVEF). Patients with corrected tetralogy of Fallot and with cardiomyopaties showed not only abnormal systolic indexes but some depressed diastolic indexes. LV density curve also disclosed isolated diastolic dysfunction in a group of aortic stenosis and in two patients with coronary lesions. A correlation of LVEF derived from the density curve and conventional area-length method was high [r= 0.91 p<0.001]. To evaluate the reproducibility, we were able to obtain the digital data twice with over one month interval on 24 patients. The intraobserver correlation was satisfactory. We applied the remasking method, resulting in improving the quality of digital images under spontaneous breathing. Our results indicated that IV-DSA was a less-invasive and clinically reliable method for assessment of LV function in children. (author)

  17. Assessing the reporting of categorised quantitative variables in observational epidemiological studies.

    Science.gov (United States)

    Mabikwa, Onkabetse V; Greenwood, Darren C; Baxter, Paul D; Fleming, Sarah J

    2017-03-14

    One aspect to consider when reporting results of observational studies in epidemiology is how quantitative risk factors are analysed. The STROBE (Strengthening the Reporting of Observational Studies in Epidemiology) guidelines recommend that researchers describe how they handle quantitative variables when analysing data. For categorised quantitative variables, the authors are required to provide reasons and justifications informing their practice. We investigated and assessed the practices and reporting of categorised quantitative variables in epidemiology. The assessment was based on five medical journals that publish epidemiological research. Observational studies published between April and June 2015 and investigating the relationships between quantitative exposures (or risk factors) and the outcomes were considered for assessment. A standard form was used to collect the data, and the reporting patterns amongst eligible studies were quantified and described. Out of 61 articles assessed for eligibility, 23 observational studies were included in the assessment. Categorisation of quantitative exposures occurred in 61% of these studies and reasons informing the practice were rarely provided. Only one article explained the choice of categorisation in the analysis. Transformation of quantitative exposures into four or five groups was common and dominant amongst studies using equally spaced categories. Dichotomisation was not popular; the practice featured in one article. Overall, the majority (86%) of the studies preferred ordered or arbitrary group categories. Other criterions used to decide categorical boundaries were based on established guidelines such as consensus statements and WHO standards. Categorisation of continuous variables remains a dominant practice in epidemiological studies. The reasons informing the practice of categorisation within published work are limited and remain unknown in most articles. The existing STROBE guidelines could provide stronger

  18. Quantitative assessment of breast density from digitized mammograms into Tabar's patterns

    International Nuclear Information System (INIS)

    Jamal, N; Ng, K-H; Looi, L-M; McLean, D; Zulfiqar, A; Tan, S-P; Liew, W-F; Shantini, A; Ranganathan, S

    2006-01-01

    We describe a semi-automated technique for the quantitative assessment of breast density from digitized mammograms in comparison with patterns suggested by Tabar. It was developed using the MATLAB-based graphical user interface applications. It is based on an interactive thresholding method, after a short automated method that shows the fibroglandular tissue area, breast area and breast density each time new thresholds are placed on the image. The breast density is taken as a percentage of the fibroglandular tissue to the breast tissue areas. It was tested in four different ways, namely by examining: (i) correlation of the quantitative assessment results with subjective classification, (ii) classification performance using the quantitative assessment technique, (iii) interobserver agreement and (iv) intraobserver agreement. The results of the quantitative assessment correlated well (r 2 = 0.92) with the subjective Tabar patterns classified by the radiologist (correctly classified 83% of digitized mammograms). The average kappa coefficient for the agreement between the readers was 0.63. This indicated moderate agreement between the three observers in classifying breast density using the quantitative assessment technique. The kappa coefficient of 0.75 for intraobserver agreement reflected good agreement between two sets of readings. The technique may be useful as a supplement to the radiologist's assessment in classifying mammograms into Tabar's pattern associated with breast cancer risk

  19. Methodology for quantitative assessment of technical condition in industrial systems

    Energy Technology Data Exchange (ETDEWEB)

    Steinbach, C. [Marintek AS (Norway); Soerli, A. [Statoil (Norway)

    1998-12-31

    As part of the Eureka project Ageing Management a methodology has been developed to assess the technical condition of industrial systems. The first part of the presentation argues for the use of technical condition parameters in the context of maintenance strategies. Thereafter the term `technical condition` is defined more thoroughly as it is used within the project. It is claimed that the technical condition of a system - such as a feed water system of a nuclear power plant, or a water injection system on an oil platform - may be determined by aggregating the condition of its smaller components using a hierarchic approach. The hierarchy has to be defined in co-operation with experienced personnel and reflects the impact of degradation of elements on a lower level to nodes higher in the hierarchy. The impact is divided into five categories with respect to safety, environment, availability, costs and man-hours. To determine the technical condition of the bottom elements of the hierarchy, available data is used from both an on-line condition monitoring system and maintenance history. The second part of the presentation introduces the prototype software tool TeCoMan which utilises the theory and applies it to installations of the participating companies. First results and gained experiences with the method and tool are discussed. (orig.)

  20. Quantitative assessment of urban transport development – a spatial approach

    Directory of Open Access Journals (Sweden)

    Czech Artur

    2018-03-01

    Full Text Available Urban transport is considered the basis of properly functioning cities and their development. The main aim of the paper is to attempt the assessment of urban transport development in selected voivodeships (provinces as a crucial factor of macro logistics. The research also aimed to identify the underdeveloped areas of urban transport in Poland as the basis for the implementation of support policy. The source of information in the investigation process was data drawn from the Central Statistical Office in Poland for 2013–2016. In the scope of dealing with the research problem, chosen classical and order multivariate statistical measures were implemented into the research process. Next, the taxonomic measures for the years of interest served as the basis for the construction of the total (general synthetic measure applicable to the entire period. The main results and findings of the research indicate that the level of urban transport development is correlated with the whole transportation system which affects the socio-economic development of some regions of Poland. The research can lead to a better understanding of Polish urban transportation development in selected regions. Hence, the results can be helpful in the investment process and for shaping the right transportation policy to improve the use of financial resources.

  1. Quantitative assessment of aquatic impacts of power plants

    Energy Technology Data Exchange (ETDEWEB)

    McKenzie, D.H.; Arnold, E.M.; Skalski, J.R.; Fickeisen, D.H.; Baker, K.S.

    1979-08-01

    Progress is reported in a continuing study of the design and analysis of aquatic environmental monitoring programs for assessing the impacts of nuclear power plants. Analysis of data from Calvert Cliffs, Pilgrim, and San Onofre nuclear power plants confirmed the generic applicability of the control-treatment pairing design suggested by McKenzie et al. (1977). Substantial progress was made on the simulation model evaluation task. A process notebook was compiled in which each model equation was translated into a standardized notation. Individual model testing and evaluating was started. The Aquatic Generalized Environmental Impact Simulator (AGEIS) was developed and will be tested using data from Lake Keowee, South Carolina. Further work is required to test the various models and perfect AGEIS for impact analyses at actual power plant sites. Efforts on the hydrologic modeling task resulted in a compendium of models commonly applied to nuclear power plants and the application of two well-received hydrodynamic models to data from the Surry Nuclear Power Plant in Virginia. Conclusions from the study of these models indicate that slight inaccuracies of boundary data have little influence on mass conservation and accurate bathymetry data are necessary for conservation of mass through the model calculations. The hydrologic modeling task provides valuable reference information for model users and monitoring program designers.

  2. Quantitative Health Risk Assessment of Indoor Radon: A Systematic Review.

    Science.gov (United States)

    Ajrouche, R; Ielsch, G; Cléro, E; Roudier, C; Gay, D; Guillevic, J; Laurier, D; Le Tertre, A

    2017-11-01

    Exposure to radon is a well-established cause of lung cancer in the general population. The aim of the present work is to identify and summarize the results of studies that have assessed the risk of lung cancer due to indoor radon, based on a systematic review of relevant published studies. Sixteen studies from 12 different countries met eligibility criteria. Large differences in radon concentrations were noted between and within individual countries, and variety of risk models used to estimate the attributable fraction. Calculating again the attributable fraction in each of these studies using the same model (coefficient of 16% per 100 becquerels per cubic meter (Bq/m3) derived from the European residential radon study), the new attributable fraction of these selected studies ranged from 3% to 17%. Radon remains a public health concern. Information about radon health risks is important and efforts are needed to decrease the associated health problems. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  3. Quantitative assessment of aquatic impacts of power plants

    International Nuclear Information System (INIS)

    McKenzie, D.H.; Arnold, E.M.; Skalski, J.R.; Fickeisen, D.H.; Baker, K.S.

    1979-08-01

    Progress is reported in a continuing study of the design and analysis of aquatic environmental monitoring programs for assessing the impacts of nuclear power plants. Analysis of data from Calvert Cliffs, Pilgrim, and San Onofre nuclear power plants confirmed the generic applicability of the control-treatment pairing design suggested by McKenzie et al. (1977). Substantial progress was made on the simulation model evaluation task. A process notebook was compiled in which each model equation was translated into a standardized notation. Individual model testing and evaluating was started. The Aquatic Generalized Environmental Impact Simulator (AGEIS) was developed and will be tested using data from Lake Keowee, South Carolina. Further work is required to test the various models and perfect AGEIS for impact analyses at actual power plant sites. Efforts on the hydrologic modeling task resulted in a compendium of models commonly applied to nuclear power plants and the application of two well-received hydrodynamic models to data from the Surry Nuclear Power Plant in Virginia. Conclusions from the study of these models indicate that slight inaccuracies of boundary data have little influence on mass conservation and accurate bathymetry data are necessary for conservation of mass through the model calculations. The hydrologic modeling task provides valuable reference information for model users and monitoring program designers

  4. Quantitative Lateral Flow Assays for Salivary Biomarker Assessment: A Review

    Science.gov (United States)

    Miočević, Olga; Cole, Craig R.; Laughlin, Mary J.; Buck, Robert L.; Slowey, Paul D.; Shirtcliff, Elizabeth A.

    2017-01-01

    Saliva is an emerging biofluid with a significant number of applications in use across research and clinical settings. The present paper explores the reasons why saliva has grown in popularity in recent years, balancing both the potential strengths and weaknesses of this biofluid. Focusing on reasons why saliva is different from other common biological fluids such as blood, urine, or tears, we review how saliva is easily obtained, with minimal risk to the donor, and reduced costs for collection, transportation, and analysis. We then move on to a brief review of the history and progress in rapid salivary testing, again reviewing the strengths and weaknesses of rapid immunoassays (e.g., lateral flow immunoassay) compared to more traditional immunoassays. We consider the potential for saliva as an alternative biofluid in a setting where rapid results are important. We focus the review on salivary tests for small molecule biomarkers using cortisol as an example. Such salivary tests can be applied readily in a variety of settings and for specific measurement purposes, providing researchers and clinicians with opportunities to assess biomarkers in real time with lower transportation, collection, and analysis costs, faster turnaround time, and minimal training requirements. We conclude with a note of cautious optimism that the field will soon gain the ability to collect and analyze salivary specimens at any location and return viable results within minutes. PMID:28660183

  5. Quantitative assessment of corpus callosum morphology in periventricular nodular heterotopia

    Science.gov (United States)

    Pardoe, Heath R.; Mandelstam, Simone A.; Hiess, Rebecca Kucharsky; Kuzniecky, Ruben I.; Jackson, Graeme D.

    2014-01-01

    We investigated systematic differences in corpus callosum morphology in periventricular nodular heterotopia (PVNH). Differences in corpus callosum mid-sagittal area and subregional area changes were measured using an automated software-based method. Heterotopic gray matter deposits were automatically labeled and compared with corpus callosum changes. The spatial pattern of corpus callosum changes were interpreted in the context of the characteristic anterior-posterior development of the corpus callosum in healthy individuals. Individuals with periventricular nodular heterotopia were imaged at the Melbourne Brain Center or as part of the multi-site Epilepsy Phenome Genome project. Whole brain T1 weighted MRI was acquired in cases (n = 48) and controls (n = 663). The corpus callosum was segmented on the mid-sagittal plane using the software “yuki”. Heterotopic gray matter and intracranial brain volume was measured using Freesurfer. Differences in corpus callosum area and subregional areas were assessed, as well as the relationship between corpus callosum area and heterotopic GM volume. The anterior-posterior distribution of corpus callosum changes and heterotopic GM nodules were quantified using a novel metric and compared with each other. Corpus callosum area was reduced by 14% in PVNH (p = 1.59 × 10−9). The magnitude of the effect was least in the genu (7% reduction) and greatest in the isthmus and splenium (26% reduction). Individuals with higher heterotopic GM volume had a smaller corpus callosum. Heterotopic GM volume was highest in posterior brain regions, however there was no linear relationship between the anterior-posterior position of corpus callosum changes and PVNH nodules. Reduced corpus callosum area is strongly associated with PVNH, and is probably associated with abnormal brain development in this neurological disorder. The primarily posterior corpus callosum changes may inform our understanding of the etiology of PVNH. Our results suggest that

  6. Flat-detector computed tomography in the assessment of intracranial stents: comparison with multi detector CT and conventional angiography in a new animal model

    International Nuclear Information System (INIS)

    Struffert, Tobias; Ott, Sabine; Adamek, Edyta; Schwarz, Marc; Engelhorn, Tobias; Kloska, Stephan; Doerfler, Arnd; Deuerling-Zheng, Yu

    2011-01-01

    Careful follow up is necessary after intracranial stenting because in-stent restenosis (ISR) or residual stenosis (RS) is not rare. A minimally invasive follow-up imaging technique is desirable. The objective was to compare the visualisation of stents in Flat Detector-CT Angiography (FD-CTA) after intravenous contrast medium injection (i.v.) with Multi Detector Computed Tomography Angiography (MD-CTA) and Digital Subtracted Angiography (DSA) in an animal model. Stents were implanted in the carotid artery of 12 rabbits. In 6 a residual stenosis (RS) was surgically created. Imaging was performed using FD-CTA, MD-CTA and DSA. Measurements of the inner and outer diameter and cross-section area of the stents were performed. Stenosis grade was calculated. In subjective evaluation FD-CTA was superior to MD-CTA. FD-CTA was more accurate compared with DSA than MD-CTA. Cross-sectional area of the stent lumen was significantly larger (p < 0.05) in FD-CTA in comparison to MD-CTA. Accurate evaluation of stenosis was impossible in MD-CTA. There was no statistically significant difference in the stenosis grade of DSA and FD-CTA. Our results show that visualisation of stent and stenosis using intravenous FD-CTA compares favourably with DSA and may replace DSA in the follow-up of patients treated with intracranial stents. (orig.)

  7. Utility of time-resolved three-dimensional magnetic resonance digital subtraction angiography without contrast material for assessment of intracranial dural arterio-venous fistula

    International Nuclear Information System (INIS)

    Hori, Masaaki; Aoki, Shigeki; Nakanishi, Atsushi; Shimoji, Keigo; Kamagata, Koji; Houshito, Haruyoshi; Kuwatsuru, Ryohei; Oishi, Hidenori; Arai, Hajime

    2011-01-01

    Background: Intracranial dural arteriovenous fistula (DAVF) is an arteriovenous shunting disease of the dura. Magnetic resonance angiography (MRA) is expected to be a safer alternative method in evaluation of DAVF, compared with invasive intra-arterial digital subtraction angiography (IADSA). Purpose: To evaluate the diagnostic use of time-spatial labeling inversion pulse (Time-SLIP) three-dimensional (3D) magnetic resonance digital subtraction angiography (MRDSA) without contrast material in six patients with DAVF. Material and Methods: Images for 3D time-of-flight MRA, which has been a valuable tool for the diagnosis of DAVF but provide little or less hemodynamic information, and Time-SLIP 3D MRDSA, were acquired for each patient. The presence, side, and grade of the disease were evaluated according to IADSA. Results: In all patients, the presence and side of the DAVF were correctly identified by both 3D time-of-flight MRA and Time-SLIP 3D MRDSA. Cortical reflux present in a patient with a grade 2b DAVF was not detected by Time-SLIP 3D MRDSA, when compared with IADSA findings. Conclusion: Time-SLIP 3D MRDSA provides hemodynamic information without contrast material and is a useful complementary tool for diagnosis of DAVF

  8. Quantitative Assessment of a Field-Based Course on Integrative Geology, Ecology and Cultural History

    Science.gov (United States)

    Sheppard, Paul R.; Donaldson, Brad A.; Huckleberry, Gary

    2010-01-01

    A field-based course at the University of Arizona called Sense of Place (SOP) covers the geology, ecology and cultural history of the Tucson area. SOP was quantitatively assessed for pedagogical effectiveness. Students of the Spring 2008 course were given pre- and post-course word association surveys in order to assess awareness and comprehension…

  9. Quantitative assessment of infection risk from exposure to waterborne pathogens in urban floodwater

    NARCIS (Netherlands)

    De Man, H.; Van Den Berg, H. H J L; Leenen, E. J T M; Schijven, J. F.; Schets, F. M.; Van Der Vliet, J. C.; Van Knapen, F.; De Roda Husman, A. M.

    Flooding and heavy rainfall have been associated with waterborne infectious disease outbreaks, however, it is unclear to which extent they pose a risk for public health. Here, risks of infection from exposure to urban floodwater were assessed using quantitative microbial risk assessment (QMRA). To

  10. An integrated environmental modeling framework for performing Quantitative Microbial Risk Assessments

    Science.gov (United States)

    Standardized methods are often used to assess the likelihood of a human-health effect from exposure to a specified hazard, and inform opinions and decisions about risk management and communication. A Quantitative Microbial Risk Assessment (QMRA) is specifically adapted to detail ...

  11. Towards quantitative condition assessment of biodiversity outcomes: Insights from Australian marine protected areas.

    Science.gov (United States)

    Addison, Prue F E; Flander, Louisa B; Cook, Carly N

    2017-08-01

    Protected area management effectiveness (PAME) evaluation is increasingly undertaken to evaluate governance, assess conservation outcomes and inform evidence-based management of protected areas (PAs). Within PAME, quantitative approaches to assess biodiversity outcomes are now emerging, where biological monitoring data are directly assessed against quantitative (numerically defined) condition categories (termed quantitative condition assessments). However, more commonly qualitative condition assessments are employed in PAME, which use descriptive condition categories and are evaluated largely with expert judgement that can be subject to a range of biases, such as linguistic uncertainty and overconfidence. Despite the benefits of increased transparency and repeatability of evaluations, quantitative condition assessments are rarely used in PAME. To understand why, we interviewed practitioners from all Australian marine protected area (MPA) networks, which have access to long-term biological monitoring data and are developing or conducting PAME evaluations. Our research revealed that there is a desire within management agencies to implement quantitative condition assessment of biodiversity outcomes in Australian MPAs. However, practitioners report many challenges in transitioning from undertaking qualitative to quantitative condition assessments of biodiversity outcomes, which are hampering progress. Challenges include a lack of agency capacity (staff numbers and money), knowledge gaps, and diminishing public and political support for PAs. We point to opportunities to target strategies that will assist agencies overcome these challenges, including new decision support tools, approaches to better finance conservation efforts, and to promote more management relevant science. While a single solution is unlikely to achieve full evidence-based conservation, we suggest ways for agencies to target strategies and advance PAME evaluations toward best practice. Copyright

  12. Contrast-enhanced MR angiography in Leriche's syndrome

    International Nuclear Information System (INIS)

    Link, J.; Steffens, J.C.; Brossmann, J.; Heller, M.; Loose, R.

    1998-01-01

    Purpose: To determine the usefulness of contrast-enhanced MR angiography for the diagnosis of Leriche's syndrome. Material and methods: Leriche's syndrome was seen in 7 patients via DSA. In [dition, contrast-enhanced MR angiography was performed (T R 7.8 ms/T E 2.1 ms, flip angle 30 , slab thickness 116 mm, slice thickness 1.82 mm, 64 partitions, FOV 500x438 mm, matrix 224x512). Results: Diagnosis of Leriche's syndrome was possible by contrast-enhanced MR angiography in each case. Visualisation of the femoral arteries was not possible in two patients by intraarterial DSA, in three other patients there was an insufficient contrast in the femoral arteries with DSA. Contrast-enhanced MR angiography revealed good visualisation of the femoral arteries in these patients. In [dition, contrast-enhanced MR angiography allowed complete visualisation of the patent lower limb arteries. In intraarterial DSA visualisation of the lower limb arteries was achieved reached in only one patient, but was incomplete. Conclusion: Contrast-enhanced MR angiography yielded the correct diagnosis of Leriche's syndrome in all 7 patients. Contrast-enhanced MR angiography was superior to DSA in the assessment of the distal run-off vessels in five of seven patients. (orig.) [de

  13. Finger joint synovitis in rheumatoid arthritis: quantitative assessment by magnetic resonance imaging

    DEFF Research Database (Denmark)

    Klarlund, Mette; Østergaard, Mikkel; Lorenzen, I

    1999-01-01

    OBJECTIVE: To assess quantitatively, by magnetic resonance imaging (MRI), the synovial membrane volume in second to fifth metacarpophalangeal (MCP) joints in patients with rheumatoid arthritis and healthy controls, and to compare the synovial membrane volumes with a more easily obtained semi-quan...... to clinical signs of synovitis, but also that the volumes may vary more than what can be accounted for by the clinical appearances. A semi-quantitative score may be sufficient for more routine purposes....

  14. CT coronary angiography vs. invasive coronary angiography in CHD

    Directory of Open Access Journals (Sweden)

    Anja Hagen

    2012-04-01

    Full Text Available Scientific background: Various diagnostic tests including conventional invasive coronary angiography and non-invasive computed tomography (CT coronary angiography are used in the diagnosis of coronary heart disease (CHD. Research questions: The present report aims to evaluate the clinical efficacy, diagnostic accuracy, prognostic value cost-effectiveness as well as the ethical, social and legal implications of CT coronary angiography versus invasive coronary angiography in the diagnosis of CHD. Methods: A systematic literature search was conducted in electronic data bases (MEDLINE, EMBASE etc. in October 2010 and was completed with a manual search. The literature search was restricted to articles published from 2006 in German or English. Two independent reviewers were involved in the selection of the relevant publications. The medical evaluation was based on systematic reviews of diagnostic studies with invasive coronary angiography as the reference standard and on diagnostic studies with intracoronary pressure measurement as the reference standard. Study results were combined in a meta-analysis with 95 % confidence intervals (CI. Additionally, data on radiation doses from current non-systematic reviews were taken into account. A health economic evaluation was performed by modelling from the social perspective with clinical assumptions derived from the meta-analysis and economic assumptions derived from contemporary German sources. Data on special indications (bypass or in-stent-restenosis were not included in the evaluation. Only data obtained using CT scanners with at least 64 slices were considered. Results: No studies were found regarding the clinical efficacy or prognostic value of CT coronary angiography versus conventional invasive coronary angiography in the diagnosis of CHD. Overall, 15 systematic reviews with data from 44 diagnostic studies using invasive coronary angiography as the reference standard (identification of obstructive

  15. Cerebral Hemodynamics in Patients with Hemolytic Uremic Syndrome Assessed by Susceptibility Weighted Imaging and Four-Dimensional Non-Contrast MR Angiography.

    Directory of Open Access Journals (Sweden)

    Ulrike Löbel

    Full Text Available Conventional magnetic resonance imaging (MRI of patients with hemolytic uremic syndrome (HUS and neurological symptoms performed during an epidemic outbreak of Escherichia coli O104:H4 in Northern Europe has previously shown pathological changes in only approximately 50% of patients. In contrast, susceptibility-weighted imaging (SWI revealed a loss of venous contrast in a large number of patients. We hypothesized that this observation may be due to an increase in cerebral blood flow (CBF and aimed to identify a plausible cause.Baseline 1.5T MRI scans of 36 patients (female, 26; male, 10; mean age, 38.2±19.3 years were evaluated. Venous contrast was rated on standard SWI minimum intensity projections. A prototype four-dimensional (time resolved magnetic resonance angiography (4D MRA assessed cerebral hemodynamics by global time-to-peak (TTP, as a surrogate marker for CBF. Clinical parameters studied were hemoglobin, hematocrit, creatinine, urea levels, blood pressure, heart rate, and end-tidal CO2.SWI venous contrast was abnormally low in 33 of 36 patients. TTP ranged from 3.7 to 10.2 frames (mean, 7.9 ± 1.4. Hemoglobin at the time of MRI (n = 35 was decreased in all patients (range, 5.0 to 12.6 g/dL; mean, 8.2 ± 1.4; hematocrit (n = 33 was abnormally low in all but a single patient (range, 14.3 to 37.2%; mean, 23.7 ± 4.2. Creatinine was abnormally high in 30 of 36 patients (83% (range, 0.8 to 9.7; mean, 3.7 ± 2.2. SWI venous contrast correlated significantly with hemoglobin (r = 0.52, P = 0.0015, hematocrit (r = 0.65, P < 0.001, and TTP (r = 0.35, P = 0.036. No correlation of SWI with blood pressure, heart rate, end-tidal CO2, creatinine, and urea level was observed. Findings suggest that the loss of venous contrast is related to an increase in CBF secondary to severe anemia related to HUS. SWI contrast of patients with pathological conventional MRI findings was significantly lower compared to patients with normal MRI (mean SWI score, 1

  16. Intraarterial digital subtraction angiography

    International Nuclear Information System (INIS)

    Davis, P.C.

    1987-01-01

    Digital subtraction angiography (DSA) refers to a radiographic technique of amplifying low levels of contrast from intravascular iodine into an acceptable image of vascular anatomy. Initial enthusiasm suggested that DSA using intravenous injections (IV-DSA) would eliminate most conventional film-screen angiographic studies. It was soon apparent, however, that IV-DSA examinations were often compromised in those patients who most needed a less invasive study. Indeed, only a 70 to 85 percent accuracy rate was achieved with IV-DSA, primarily due to motion artifact, poor cardiac output, overlap of pertinent vessels, and inability to resolve smaller vessels

  17. Nonenhanced MR angiography techniques

    International Nuclear Information System (INIS)

    Lanzman, R.S.; Kroepil, P.; Blondin, D.; Schmitt, P.

    2011-01-01

    Especially in regard to the potential risks for the development of nephrogenic systemic fibrosis (NSF) following the administration of Gadolinium-based contrast material, nonenhanced MR angiography (MRA) methods are becoming ever more important. Besides well-established time-of-flight (TOF) and phase-contrast (PC) MRA, alternative imaging techniques based on balanced steady-state free precession (bSSFP) and turbo-spin-echo (TSE) sequences are increasingly used in combination with or without arterial spin labeling (ASL) strategies. This article provides an overview of the principles and clinical values of different nonenhanced MRA techniques. In addition, recent nonenhanced MRA developments are presented. (orig.)

  18. Usefulness of MR angiography in renal tumor

    International Nuclear Information System (INIS)

    Oka, Toshitsugu; Morimoto, Kouji; Nishimura, Kenji; Tsujimura, Akira; Yasunaga, Yutaka; Matsumiya, Kiyomi; Takaha, Minato

    1992-01-01

    MR angiography using a gradient-echo, pulse sequence FLASH (fast, low-angle shot) method during breath-hold with a 'MAGNETOM H-15' scanner (1.5 Tesla; Siemens Medical System) was performed on 27 patients with renal tumor at our clinic between Feburary 20, 1990 and September 30, 1991 and we studied to evaluate its usefulness. Of these 27 patients, 22 patients including one patient under hemodialysis treatment had renal cell carcinoma and one patient had oncocytoma pathologically proven from the excised specimens. The remaining four patients including two patients associated with inferior vena cava tumor thrombus were clinically diagnosed as renal cell carcinoma based on the result of imaging examinations such as excretory urography, ultrasonography, computed tomography and conventional angiography. However, they could not be operated on because their tumors were too advanced. By reconstruction of the data of consecutive coronal scans of the abdominal blood vessels such as the abdominal aorta, inferior vena cava and renal arteries and veins simultaneously without any intravenous contrast materials. Our present study revealed that MR angiography has some advantages, especially with regard to preoperative angiographic information about the abdomen of patients with renal tumor. That is, MR angiography can delineate many kinds of arteries and veins of the abdomen simultaneously and in a broader range, as well as it can be performed on the patients with hypersensitivity to iodinate contrast materials or renal insufficiency in a usual fashion. Furthermore, our present study suggested that the MR angiography is useful for assessing the presence and extent of inferior vena caval tumor thrombus of renal cell carcinoma and for clearly distinguishing tumor lesion and the surrounding normal renal parenchyma in the patients with renal tumor. (author)

  19. Prevalence and Characteristics of Myocardial Bridging in Multidetector-Row Computed Tomography Coronary Angiography

    International Nuclear Information System (INIS)

    Carrascosa, Patricia; Martin Lopez, Elba; Capunay, Carlos; Deviggiano, Alejandro; Vallejos, Javier; Carrascosa, Jorge

    2009-01-01

    Background: Myocardial bridging (MB) are congenital defects of the coronary arteries in which a segment of an epicardial artery lies in the myocardium for part of its course. The current gold standard for diagnosing MB is coronary angiography; however other invasive techniques are also useful. Myocardial bridging can also be visualized with the use of novel non-invasive imaging techniques such as multidetector-row computed tomography coronary angiography (MDCT-CA). Objectives: To assess the prevalence and characteristics of myocardial bridging in patients undergoing multidetector-row computed tomography coronary angiography (MDCT-CA). Material and Methods: A total of 452 consecutive patients were evaluated with 16-row and 64-row MDCT-CA due to the presence of abnormal findings in myocardial perfusion image tests, symptoms suggestive of coronary artery disease, and in asymptomatic patients with a family history of coronary artery disease. The presence of MB, their location and characteristics were analyzed. Myocardial bridging were classified as complete and incomplete bridges with respect to continuity of the myocardium over the tunneled segment of the artery involved. Quantitative measurements of vessel diameter during systole and diastole were evaluated. Results: The prevalence of MB was 35.18%; 88 were complete and 71 incomplete. Among complete MB, 6 affected both systole and diastole, 27 presented only systolic compression and 55 showed no compression. Incomplete MB showed absence of arterial compression. Conclusions: Multidetector-row computed tomography coronary angiography detected a higher prevalence of MB in the study population and allowed to classify them and to assess their functional aspects throughout the cardiac cycle. (authors) [es

  20. Diagnostic accuracy of coronary angiography with multislice computed tomography applied to 'the Real World'

    International Nuclear Information System (INIS)

    Rodriguez Granillo, Gaston A.; Rosales, Miguel A.; Llaurado, Claudio; Fernandez Pereira, Carlos; Garcia Carcia, Hector M.

    2006-01-01

    Objective: To assess the diagnostic accuracy of Coronary Angiography with Multislice Computed Tomography (MSCT) for the detection of significant coronary artery stenoses. Material and methods: Patients studied had an indication for diagnostic coronary angiography and no history of contrast allergies, renal failure or arrhythmias. A multislice tomography equipment (Brilliance 40, Philips, The Netherlands) with ECG gating was used for image acquisition. A total of 90-125 mI of iodinated contrast was administered by IV route. Obesity, diabetes, diffusely calcified segments with a diameter < 2.0 mm, and segments treated with stents were not considered exclusion criteria. Lesions were defined as significant when the decrease in Iumen was ≥ 50% by MSCT and quantitative coronary angiography (QCA). Results: A total of 38 patients were scanned before the intervention. Of them, one (3%) was excluded because of inadequate image quality. The remaining 37 patients (444 segments), with an adequate quality image, were included in the study (81% men, mean age 62.43 ± 12.5 years, 13.5% diabetics). Mean scan time was 15.12 ± 2.6 seconds, and 444 segments were assessed with both techniques. The number of lesions deemed significant by QCA and MSCT were 88 (17%) and 93 (18%), respectively. Sensitivity, specificity, positive and negative predictive values of MSCT to detect significant stenoses were 82%, 93%, 72% and 96%, respectively. Conclusion: In non-selected patients, coronary angiography by multislice computed tomography exhibits a high negative predictive value for the detection of obstructive coronary disease. (author)

  1. Safety and efficacy of dual-axis rotational coronary angiography vs. standard coronary angiography.

    Science.gov (United States)

    Klein, Andrew J; Garcia, Joel A; Hudson, Paul A; Kim, Michael S; Messenger, John C; Casserly, Ivan P; Wink, Onno; Hattler, Brack; Tsai, Thomas T; Chen, S Y James; Hansgen, Adam; Carroll, John D

    2011-05-01

    To determine the safety and efficacy of dual-axis rotational coronary angiography (DARCA) by directly comparing it to standard coronary angiography (SA). Standard coronary angiography (SA) requires numerous fixed static images of the coronary tree and has multiple well-documented limitations. Dual-axis rotational coronary angiography (DARCA) is a new rotational acquisition technique that entails simultaneous LAO/RAO and cranial/caudal gantry movement. This technological advancement obtains numerous unique images of the left or right coronary tree with a single coronary injection. We sought to assess the safety and efficacy of DARCA as well as determine DARCA's adequacy for CAD screening and assessment. Thirty patients underwent SA following by DARCA. Contrast volume, radiation dose (DAP) and procedural time were recorded for each method to assess safety. For DARCA acquisitions, blood pressure (BP), heart rate (HR), symptoms and any arrhythmias were recorded. All angiograms were reviewed for CAD screening adequacy by two independent invasive cardiologists. Compared to SA, use of DARCA was associated with a 51% reduction in contrast, 35% less radiation exposure, and 18% shorter procedural time. Both independent reviewers noted DARCA to be at least equivalent to SA with respect to the ability to screen for CAD. DARCA represents a new angiographic technique which is equivalent in terms of image quality and is associated with less contrast use, radiation exposure, and procedural time than SA. Copyright © 2011 Wiley-Liss, Inc.

  2. Quantitative risk assessment of continuous liquid spill fires based on spread and burning behaviours

    DEFF Research Database (Denmark)

    Zhao, Jinlong; Huang, Hong; Li, Yuntao

    2017-01-01

    Spill fires usually occur during the storage and transportation of hazardous materials, posing a threat to the people and environment in their immediate proximity. In this paper, a classical Quantitative Risk Assessment (QRA) method is used to assess the risk of spill fires. In this method, the m......, large-scale experiments of spill fires on water and a glass sheet were conducted to verify the accuracy and application of the model. The results show that the procedure we developed can be used to quantitatively calculate the risk associated with a continuous spill fire....

  3. Assessing College Students’ Quantitative and Scientific Reasoning: The James Madison University Story

    Directory of Open Access Journals (Sweden)

    John D. Hathcoat

    2015-01-01

    Full Text Available Quantitative and scientific reasoning is a critical student learning outcome in higher education. Data are presented for large samples of undergraduate students who were assessed as entering freshmen and then again after completing 45-70 credit hours. Results are presented around four key issues that are central to educational assessment. First, entering freshmen with transfer credits for quantitative and scientific reasoning courses that fulfill general education requirements, on average, score similar to entering freshmen without such credit. About 97% of entering freshmen who had transfer credits received their credits through dual enrollment programs. As a sophomore-junior, students who had completed their general education requirements performed similar to students who had started, but not yet finished these requirements. Second, small to moderate correlations were observed between grade-point averages in relevant general education coursework and quantitative and scientific reasoning. Third, students’ quantitative and scientific reasoning, on average, increases from freshmen to sophomore/junior years. Finally, the proportion of students who meet faculty-set standards substantially increases from pre-test to post-test. Taken together, results suggest that changes in quantitative and scientific reasoning are a function of relevant courses. Additional research is needed to examine the role of lower-level versus higher-level courses in student performance. Results also indicate a need to investigate how differences in the quality of dual enrollment courses facilitate quantitative and scientific reasoning.

  4. A qualitative and quantitative assessment for a bone marrow harvest simulator.

    Science.gov (United States)

    Machado, Liliane S; Moraes, Ronei M

    2009-01-01

    Several approaches to perform assessment in training simulators based on virtual reality have been proposed. There are two kinds of assessment methods: offline and online. The main requirements related to online training assessment methodologies applied to virtual reality systems are the low computational complexity and the high accuracy. In the literature it can be found several approaches for general cases which can satisfy such requirements. An inconvenient about those approaches is related to an unsatisfactory solution for specific cases, as in some medical procedures, where there are quantitative and qualitative information available to perform the assessment. In this paper, we present an approach to online training assessment based on a Modified Naive Bayes which can manipulate qualitative and quantitative variables simultaneously. A special medical case was simulated in a bone marrow harvest simulator. The results obtained were satisfactory and evidenced the applicability of the method.

  5. Quantitative image analysis in the assessment of diffuse large B-cell lymphoma.

    Science.gov (United States)

    Chabot-Richards, Devon S; Martin, David R; Myers, Orrin B; Czuchlewski, David R; Hunt, Kristin E

    2011-12-01

    Proliferation rates in diffuse large B-cell lymphoma have been associated with conflicting outcomes in the literature, more often with high proliferation associated with poor prognosis. In most studies, the proliferation rate was estimated by a pathologist using an immunohistochemical stain for the monoclonal antibody Ki-67. We hypothesized that a quantitative image analysis algorithm would give a more accurate estimate of the proliferation rate, leading to better associations with survival. In all, 84 cases of diffuse large B-cell lymphoma were selected according to the World Health Organization criteria. Ki-67 percentage positivity estimated by the pathologist was recorded from the original report. The same slides were then scanned using an Aperio ImageScope, and Ki-67 percentage positivity was calculated using a computer-based quantitative immunohistochemistry nuclear algorithm. In addition, chart review was performed and survival time was recorded. The Ki-67 percentage estimated by the pathologist from the original report versus quantitative image analysis was significantly correlated (Pquantitative image analysis (P=0.021). There was less agreement at lower Ki-67 percentages. Comparison of Ki-67 percentage positivity versus survival did not show significant association either with pathologist estimate or quantitative image analysis. However, although not significant, there was a trend of worse survival at higher proliferation rates detected by the pathologist but not by quantitative image analysis. Interestingly, our data suggest that the Ki-67 percentage positivity as assessed by the pathologist may be more closely associated with survival outcome than that identified by quantitative image analysis. This may indicate that pathologists are better at selecting appropriate areas of the slide. More cases are needed to assess whether this finding would be statistically significant. Due to the good correlation between pathologist estimate and quantitative image

  6. A framework for organizing and selecting quantitative approaches for benefit-harm assessment

    Directory of Open Access Journals (Sweden)

    Puhan Milo A

    2012-11-01

    Full Text Available Abstract Background Several quantitative approaches for benefit-harm assessment of health care interventions exist but it is unclear how the approaches differ. Our aim was to review existing quantitative approaches for benefit-harm assessment and to develop an organizing framework that clarifies differences and aids selection of quantitative approaches for a particular benefit-harm assessment. Methods We performed a review of the literature to identify quantitative approaches for benefit-harm assessment. Our team, consisting of clinicians, epidemiologists, and statisticians, discussed the approaches and identified their key characteristics. We developed a framework that helps investigators select quantitative approaches for benefit-harm assessment that are appropriate for a particular decisionmaking context. Results Our framework for selecting quantitative approaches requires a concise definition of the treatment comparison and population of interest, identification of key benefit and harm outcomes, and determination of the need for a measure that puts all outcomes on a single scale (which we call a benefit and harm comparison metric. We identified 16 quantitative approaches for benefit-harm assessment. These approaches can be categorized into those that consider single or multiple key benefit and harm outcomes, and those that use a benefit-harm comparison metric or not. Most approaches use aggregate data and can be used in the context of single studies or systematic reviews. Although the majority of approaches provides a benefit and harm comparison metric, only four approaches provide measures of uncertainty around the benefit and harm comparison metric (such as a 95 percent confidence interval. None of the approaches considers the actual joint distribution of benefit and harm outcomes, but one approach considers competing risks when calculating profile-specific event rates. Nine approaches explicitly allow incorporating patient preferences

  7. Assessing covariate balance when using the generalized propensity score with quantitative or continuous exposures.

    Science.gov (United States)

    Austin, Peter C

    2018-01-01

    Propensity score methods are increasingly being used to estimate the effects of treatments and exposures when using observational data. The propensity score was initially developed for use with binary exposures (e.g., active treatment vs. control). The generalized propensity score is an extension of the propensity score for use with quantitative exposures (e.g., dose or quantity of medication, income, years of education). A crucial component of any propensity score analysis is that of balance assessment. This entails assessing the degree to which conditioning on the propensity score (via matching, weighting, or stratification) has balanced measured baseline covariates between exposure groups. Methods for balance assessment have been well described and are frequently implemented when using the propensity score with binary exposures. However, there is a paucity of information on how to assess baseline covariate balance when using the generalized propensity score. We describe how methods based on the standardized difference can be adapted for use with quantitative exposures when using the generalized propensity score. We also describe a method based on assessing the correlation between the quantitative exposure and each covariate in the sample when weighted using generalized propensity score -based weights. We conducted a series of Monte Carlo simulations to evaluate the performance of these methods. We also compared two different methods of estimating the generalized propensity score: ordinary least squared regression and the covariate balancing propensity score method. We illustrate the application of these methods using data on patients hospitalized with a heart attack with the quantitative exposure being creatinine level.

  8. Coronary CT angiography and MR angiography of Kawasaki disease

    International Nuclear Information System (INIS)

    Goo, Hyun Woo; Park, In-Sook; Ko, Jae Kon; Kim, Young Hwee

    2006-01-01

    Although the incidence of coronary artery aneurysms has diminished in patients with Kawasaki disease, coronary artery involvement is still regarded as a major complication of the disease, significantly affecting morbidity and mortality. Recent technical advances in coronary CT angiography (CTA) and MR angiography (MRA) have led to the possibility of using these two imaging methods as minimally invasive alternatives to the more invasive diagnostic catheter angiography in evaluating coronary artery abnormalities, such as aneurysm, stenosis, and occlusion. In this article, we describe imaging techniques and findings of coronary CTA and MRA in Kawasaki disease. (orig.)

  9. Penumbra pattern assessment in acute stroke patients: comparison of quantitative and non-quantitative methods in whole brain CT perfusion.

    Directory of Open Access Journals (Sweden)

    Kolja M Thierfelder

    Full Text Available BACKGROUND AND PURPOSE: While penumbra assessment has become an important part of the clinical decision making for acute stroke patients, there is a lack of studies measuring the reliability and reproducibility of defined assessment techniques in the clinical setting. Our aim was to determine reliability and reproducibility of different types of three-dimensional penumbra assessment methods in stroke patients who underwent whole brain CT perfusion imaging (WB-CTP. MATERIALS AND METHODS: We included 29 patients with a confirmed MCA infarction who underwent initial WB-CTP with a scan coverage of 100 mm in the z-axis. Two blinded and experienced readers assessed the flow-volume-mismatch twice and in two quantitative ways: Performing a volumetric mismatch analysis using OsiriX imaging software (MM(VOL and visual estimation of mismatch (MM(EST. Complementarily, the semiquantitative Alberta Stroke Programme Early CT Score for CT perfusion was used to define mismatch (MM(ASPECTS. A favorable penumbral pattern was defined by a mismatch of ≥ 30% in combination with a cerebral blood flow deficit of ≤ 90 ml and an MM(ASPECTS score of ≥ 1, respectively. Inter- and intrareader agreement was determined by Kappa-values and ICCs. RESULTS: Overall, MM(VOL showed considerably higher inter-/intrareader agreement (ICCs: 0.751/0.843 compared to MM(EST (0.292/0.749. In the subgroup of large (≥ 50 mL perfusion deficits, inter- and intrareader agreement of MM(VOL was excellent (ICCs: 0.961/0.942, while MM(EST interreader agreement was poor (0.415 and intrareader agreement was good (0.919. With respect to penumbra classification, MM(VOL showed the highest agreement (interreader agreement: 25 agreements/4 non-agreements/κ: 0.595; intrareader agreement 27/2/0.833, followed by MM(EST (22/7/0.471; 23/6/0.577, and MM(ASPECTS (18/11/0.133; 21/8/0.340. CONCLUSION: The evaluated approach of volumetric mismatch assessment is superior to pure visual and ASPECTS penumbra

  10. Genetic toxicology at the crossroads-from qualitative hazard evaluation to quantitative risk assessment.

    Science.gov (United States)

    White, Paul A; Johnson, George E

    2016-05-01

    Applied genetic toxicology is undergoing a transition from qualitative hazard identification to quantitative dose-response analysis and risk assessment. To facilitate this change, the Health and Environmental Sciences Institute (HESI) Genetic Toxicology Technical Committee (GTTC) sponsored a workshop held in Lancaster, UK on July 10-11, 2014. The event included invited speakers from several institutions and the contents was divided into three themes-1: Point-of-departure Metrics for Quantitative Dose-Response Analysis in Genetic Toxicology; 2: Measurement and Estimation of Exposures for Better Extrapolation to Humans and 3: The Use of Quantitative Approaches in Genetic Toxicology for human health risk assessment (HHRA). A host of pertinent issues were discussed relating to the use of in vitro and in vivo dose-response data, the development of methods for in vitro to in vivo extrapolation and approaches to use in vivo dose-response data to determine human exposure limits for regulatory evaluations and decision-making. This Special Issue, which was inspired by the workshop, contains a series of papers that collectively address topics related to the aforementioned themes. The Issue includes contributions that collectively evaluate, describe and discuss in silico, in vitro, in vivo and statistical approaches that are facilitating the shift from qualitative hazard evaluation to quantitative risk assessment. The use and application of the benchmark dose approach was a central theme in many of the workshop presentations and discussions, and the Special Issue includes several contributions that outline novel applications for the analysis and interpretation of genetic toxicity data. Although the contents of the Special Issue constitutes an important step towards the adoption of quantitative methods for regulatory assessment of genetic toxicity, formal acceptance of quantitative methods for HHRA and regulatory decision-making will require consensus regarding the

  11. Multislice computed tomographic coronary angiography: experience in a UK centre

    International Nuclear Information System (INIS)

    Morgan-Hughes, G.J.; Marshall, A.J.; Roobottom, C.A.

    2003-01-01

    AIM: To evaluate the technique of coronary angiography with retrospectively electrocardiogram (ECG)-gated four-slice helical computed tomography (CT). MATERIALS AND METHODS: Within 1 month of undergoing routine day-case diagnostic coronary angiography, 30 consecutive patients also underwent retrospectively ECG-gated multislice CT coronary angiography. This enabled direct comparison of seven segments of proximal and mid-coronary artery for each patient by two blinded assessors. Each segment of coronary artery from the multislice CT image was evaluated initially for 'assessability' and those segments deemed assessable were subsequently investigated for the presence or absence of a significantly (n=70%) stenotic lesion. RESULTS: Overall 68% of proximal and mid-coronary artery segments were assessable. The sensitivity and specificity of four-slice CT coronary angiography in assessable segments for detecting the presence or absence (n=70%) of stenoses were 72 and 86%, respectively. These results correspond to a positive predictive value of 53% and a 93% negative predictive value. If the 32% of non-assessable segments are added into the calculation then the sensitivity and specificity fall to 49 and 66%, respectively. CONCLUSION: Although multislice CT coronary angiography is a promising technique, the overall assessability and diagnostic accuracy of four-slice CT acquisition is not sufficient to justify routine clinical use. Further, evaluation should investigate the benefit of the reduction in temporal and spatial resolution offered by 16 and 32 slice acquisition

  12. A Quantitative Synthesis of Developmental Disability Research: The Impact of Functional Assessment Methodology on Treatment Effectiveness

    Science.gov (United States)

    Delfs, Caitlin H.; Campbell, Jonathan M.

    2010-01-01

    Methods and outcomes from functional behavioral assessment have been researched widely over the past twenty-five years. However, several important research questions have yet to be examined sufficiently. This quantitative review of developmental disability research aims to make comparisons of different functional behavioral assessment…

  13. Evaluating quantitative and qualitative models: An application for nationwide water erosion assessment in Ethiopia

    NARCIS (Netherlands)

    Sonneveld, B.G.J.S.; Keyzer, M.A.; Stroosnijder, L

    2011-01-01

    This paper tests the candidacy of one qualitative response model and two quantitative models for a nationwide water erosion hazard assessment in Ethiopia. After a descriptive comparison of model characteristics the study conducts a statistical comparison to evaluate the explanatory power of the

  14. Evaluating quantitative and qualitative models: an application for nationwide water erosion assessment in Ethiopia

    NARCIS (Netherlands)

    Sonneveld, B.G.J.S.; Keyzer, M.A.; Stroosnijder, L.

    2011-01-01

    This paper tests the candidacy of one qualitative response model and two quantitative models for a nationwide water erosion hazard assessment in Ethiopia. After a descriptive comparison of model characteristics the study conducts a statistical comparison to evaluate the explanatory power of the

  15. Climate Change Education: Quantitatively Assessing the Impact of a Botanical Garden as an Informal Learning Environment

    Science.gov (United States)

    Sellmann, Daniela; Bogner, Franz X.

    2013-01-01

    Although informal learning environments have been studied extensively, ours is one of the first studies to quantitatively assess the impact of learning in botanical gardens on students' cognitive achievement. We observed a group of 10th graders participating in a one-day educational intervention on climate change implemented in a botanical garden.…

  16. Assessment of quantitative hypertrophy scores in hypertrophic cardiomyopathy : Magnetic resonance imaging versus echocardiography

    NARCIS (Netherlands)

    Posma, JL; Blanksma, PK; vanderWall, EE; Hamer, HPM; Mooyaart, EL; Lie, KI

    1996-01-01

    To compare the diagnostic value of spin-echo magnetic resonance (MR) imaging and transthoracic echocardiography in quantitative assessment of the extent of hypertrophy in patients with hypertrophic cardiomyopathy (HCM), we examined 52 consecutive patients with HCM. The Spirito-Maron and Wigle

  17. Quantitative Approach to Collaborative Learning: Performance Prediction, Individual Assessment, and Group Composition

    Science.gov (United States)

    Cen, Ling; Ruta, Dymitr; Powell, Leigh; Hirsch, Benjamin; Ng, Jason

    2016-01-01

    The benefits of collaborative learning, although widely reported, lack the quantitative rigor and detailed insight into the dynamics of interactions within the group, while individual contributions and their impacts on group members and their collaborative work remain hidden behind joint group assessment. To bridge this gap we intend to address…

  18. Is Survival Time After Hemorrhage a Heritable, Quantitative Trait?: An Initial Assessment

    Science.gov (United States)

    2008-06-01

    QUANTITATIVE TRAIT?: AN INITIAL ASSESSMENT Harold G. Klemcke,* David G. Baer,* V. Shane Pankratz,† Ashley Cox,* Douglas S. Cortez,* Michael R. Garrett...Andric B, Simovic M, Dujic A, Marinkovic D: Genetic basis of resistance to trauma in inbred strains of mice. J Trauma 30:211Y213, 1990. 45. Canter J

  19. Quantitative risk assessment for skin sensitisation : Consideration of a simplified approach for hair dye ingredients

    NARCIS (Netherlands)

    Goebel, C.; Diepgen, T.L.; Krasteva, M.; Schlatter, H.; Nicolas, J.F.; Blomeke, B.; Coenraads, P.J.; Schnuch, A.; Taylor, J.S.; Pungier, J.; Fautz, R.; Fuchs, A.; Schuh, W.; Gerberick, G.F.; Kimber, I.

    2012-01-01

    With the availability of the local lymph node assay, and the ability to evaluate effectively the relative skin sensitizing potency of contact allergens, a model for quantitative-risk-assessment (QRA) has been developed. This QRA process comprises: (a) determination of a

  20. A suite of models to support the quantitative assessment of spread in pest risk analysis

    NARCIS (Netherlands)

    Robinet, C.; Kehlenbeck, H.; Werf, van der W.

    2012-01-01

    In the frame of the EU project PRATIQUE (KBBE-2007-212459 Enhancements of pest risk analysis techniques) a suite of models was developed to support the quantitative assessment of spread in pest risk analysis. This dataset contains the model codes (R language) for the four models in the suite. Three

  1. Wet meadow restoration in Western Europe : A quantitative assessment of the effectiveness of several techniques

    NARCIS (Netherlands)

    Klimkowska, Agata; Diggelen, Rudy Van; Bakker, Jan P.; Grootjans, Ab P.

    2007-01-01

    Techniques such as rewetting, topsoil removal, diaspore transfer or combinations of these are increasingly applied in fen meadow and flood meadow restoration in Western Europe. In this paper, we present a quantitative assessment of the effectiveness of the commonly used meadow restoration methods.

  2. TB/HIV integration at primary care level: A quantitative assessment ...

    African Journals Online (AJOL)

    2012-09-02

    Sep 2, 2012 ... asymptomatic PLWH were offered IPT. Infection control. TB/HIV integration at primary care level: A quantitative assessment at 3 clinics in. Johannesburg, South Africa. L Page-Shipp, Y Voss De Lima,K Clouse,J de Vos, L Evarts, J Bassett, I Sanne, A Van Rie. Right to Care, Johannesburg. L Page-Shipp, MB ...

  3. Understanding outbreaks of waterborne infectious disease: quantitative microbial risk assessment vs. epidemiology

    Science.gov (United States)

    Drinking water contaminated with microbial pathogens can cause outbreaks of infectious disease, and these outbreaks are traditionally studied using epidemiologic methods. Quantitative microbial risk assessment (QMRA) can predict – and therefore help prevent – such outbreaks, but it has never been r...

  4. The value of quantitative patient preferences in regulatory benefit-risk assessment

    NARCIS (Netherlands)

    Oude Egbrink, Mart; IJzerman, Maarten Joost

    2014-01-01

    Quantitative patient preferences are a method to involve patients in regulatory benefit-risk assessment. Assuming preferences can be elicited, there might be multiple advantages to their use. Legal, methodological and procedural issues do however imply that preferences are currently at most part of

  5. Using MFM methodology to generate and define major accident scenarios for quantitative risk assessment studies

    DEFF Research Database (Denmark)

    Hua, Xinsheng; Wu, Zongzhi; Lind, Morten

    2017-01-01

    Generating and defining Major Accident Scenarios (MAS) are commonly agreed as the key step for quantitative risk assessment (QRA). The aim of the study is to explore the feasibility of using Multilevel Flow Modeling (MFM) methodology to formulating MAS. Traditionally this is usually done based...

  6. Superselective pseudo-continuous arterial spin labeling angiography

    Energy Technology Data Exchange (ETDEWEB)

    Jensen-Kondering, Ulf [Department of Radiology and Neuroradiology, University Medical Center Schleswig-Holstein, Kiel (Germany); Lindner, Thomas, E-mail: thomas.lindner@uksh.de [Department of Radiology and Neuroradiology, University Medical Center Schleswig-Holstein, Kiel (Germany); Osch, Matthias J.P. van [C. J. Gorter Center for High Field MRI, Department of Radiology, Leiden University Medical Center, Leiden (Netherlands); Rohr, Axel; Jansen, Olav [Department of Radiology and Neuroradiology, University Medical Center Schleswig-Holstein, Kiel (Germany); Helle, Michael [Department of Radiology and Neuroradiology, University Medical Center Schleswig-Holstein, Kiel (Germany); Now with Philips GmbH Innovative Technologies, Research Laboratories, Hamburg (Germany)

    2015-09-15

    Highlights: • Superselective arterial spin labeling was capable of acquiring angiograms of individually selected arteries. • Image quality was similar compared with a routinely used time-of-flight angiography. • Superselective arterial spin labeling was utilized in patients with arterio-venous malformations and made it possible to visualize individual feeding vessels in a complete non-invasive way - Abstract: Purpose: To evaluate the utility of a novel non-contrast enhanced, vessel-selective magnetic resonance angiography (MRA) approach based on superselective pseudo-continuous arterial spin labeling (ASL) for the morphologic assessment of intracranial arteries when compared to a clinically used time-of-flight (TOF) MRA. Materials and methods: Three sets of selective ASL angiographies (right and left internal carotid artery, basilar artery) as well as one TOF data set were obtained from each of the five volunteers included in this study on a clinical 1.5T system. The depiction of arterial segments as well as their delineation was evaluated and independently analyzed by two radiologists. Additionally, the ASL angiography approach was performed in two patients suffering from arterio-venous malformations (AVM) in order to illustrate potential applications in a clinical setting. Results: In both angiography techniques, intracranial arteries and their segments (distal branches up to A5 segments of the anterior cerebral arteries, M8 segments of the middle cerebral arteries, and P5 segments of the posterior cerebral arteries) were continuously depicted with excellent inter-reader agreement (κ > 0.81). In AVM patients, reconstructed images of the TOF angiography presented similar information about the size and shape of the AVM as did superselective ASL angiography. In addition, the acquired ASL angiograms of selected vessels allowed assessing the blood supply of individually labeled arteries to the AVM which could also be confirmed by digital subtraction angiography

  7. Superselective pseudo-continuous arterial spin labeling angiography

    International Nuclear Information System (INIS)

    Jensen-Kondering, Ulf; Lindner, Thomas; Osch, Matthias J.P. van; Rohr, Axel; Jansen, Olav; Helle, Michael

    2015-01-01

    Highlights: • Superselective arterial spin labeling was capable of acquiring angiograms of individually selected arteries. • Image quality was similar compared with a routinely used time-of-flight angiography. • Superselective arterial spin labeling was utilized in patients with arterio-venous malformations and made it possible to visualize individual feeding vessels in a complete non-invasive way - Abstract: Purpose: To evaluate the utility of a novel non-contrast enhanced, vessel-selective magnetic resonance angiography (MRA) approach based on superselective pseudo-continuous arterial spin labeling (ASL) for the morphologic assessment of intracranial arteries when compared to a clinically used time-of-flight (TOF) MRA. Materials and methods: Three sets of selective ASL angiographies (right and left internal carotid artery, basilar artery) as well as one TOF data set were obtained from each of the five volunteers included in this study on a clinical 1.5T system. The depiction of arterial segments as well as their delineation was evaluated and independently analyzed by two radiologists. Additionally, the ASL angiography approach was performed in two patients suffering from arterio-venous malformations (AVM) in order to illustrate potential applications in a clinical setting. Results: In both angiography techniques, intracranial arteries and their segments (distal branches up to A5 segments of the anterior cerebral arteries, M8 segments of the middle cerebral arteries, and P5 segments of the posterior cerebral arteries) were continuously depicted with excellent inter-reader agreement (κ > 0.81). In AVM patients, reconstructed images of the TOF angiography presented similar information about the size and shape of the AVM as did superselective ASL angiography. In addition, the acquired ASL angiograms of selected vessels allowed assessing the blood supply of individually labeled arteries to the AVM which could also be confirmed by digital subtraction angiography

  8. Development and Assessment of Modules to Integrate Quantitative Skills in Introductory Biology Courses

    Science.gov (United States)

    Hoffman, Kathleen; Leupen, Sarah; Dowell, Kathy; Kephart, Kerrie; Leips, Jeff

    2016-01-01

    Redesigning undergraduate biology courses to integrate quantitative reasoning and skill development is critical to prepare students for careers in modern medicine and scientific research. In this paper, we report on the development, implementation, and assessment of stand-alone modules that integrate quantitative reasoning into introductory biology courses. Modules are designed to improve skills in quantitative numeracy, interpreting data sets using visual tools, and making inferences about biological phenomena using mathematical/statistical models. We also examine demographic/background data that predict student improvement in these skills through exposure to these modules. We carried out pre/postassessment tests across four semesters and used student interviews in one semester to examine how students at different levels approached quantitative problems. We found that students improved in all skills in most semesters, although there was variation in the degree of improvement among skills from semester to semester. One demographic variable, transfer status, stood out as a major predictor of the degree to which students improved (transfer students achieved much lower gains every semester, despite the fact that pretest scores in each focus area were similar between transfer and nontransfer students). We propose that increased exposure to quantitative skill development in biology courses is effective at building competency in quantitative reasoning. PMID:27146161

  9. Comparison of contrast-enhanced magnetic resonance angiography and conventional pulmonary angiography for the diagnosis of pulmonary embolism : a prospective study

    NARCIS (Netherlands)

    Oudkerk, M; van Beek, EJR; Wielopolski, P; van Ooijen, PMA; Brouwers-Kuyper, EMJ; Bongaerts, AHH; Berghout, A

    2002-01-01

    Background Diagnostic strategies for pulmonary embolism are complex and consist of non-invasive diagnostic tests done to avoid conventional pulmonary angiography as much as possible. We aimed to assess the diagnostic accuracy of magnetic resonance angiography (MRA) for the diagnosis of pulmonary

  10. EFFICIENT QUANTITATIVE RISK ASSESSMENT OF JUMP PROCESSES: IMPLICATIONS FOR FOOD SAFETY

    OpenAIRE

    Nganje, William E.

    1999-01-01

    This paper develops a dynamic framework for efficient quantitative risk assessment from the simplest general risk, combining three parameters (contamination, exposure, and dose response) in a Kataoka safety-first model and a Poisson probability representing the uncertainty effect or jump processes associated with food safety. Analysis indicates that incorporating jump processes in food safety risk assessment provides more efficient cost/risk tradeoffs. Nevertheless, increased margin of safety...

  11. Do quantitative metrics derived from standard fluoroscopy phantoms used for quality control assess vendor-specific advancements in interventional fluoroscopy systems?

    Science.gov (United States)

    Forsberg, Mark A.; Eschelman, David J.; Talreja, Prakruti; Dave, Jaydev K.

    2017-03-01

    Approximately 9 million fluoroscopically-guided interventional procedures are performed annually in the USA. Recent technological advancements for interventional fluoroscopy systems have focused towards vendor-specific real-time image and signal processing. Hence, the purpose of this study was to evaluate if quantitative metrics derived from standard image quality phantoms, routinely used for quality control, are able to distinguish vendor-specific processing features for interventional fluoroscopy systems. Six standard image quality phantoms were used to measure contrast-to-noise ratio (CNR), full-width-at-half-maximum (for determining edge blurring) and modulation transfer function, to analyze contrast detail characteristics, and to assess digital subtraction angiography (DSA) performance of six flat-panel detector based interventional fluoroscopy systems from Philips (with and without ClarityIQ) and Siemens. Phantom data were acquired at different dose modes and field-of-view settings. Fluoroscopy loops and digital subtraction acquisitions were saved (duration 3 seconds; repeated 3 times). Images were analyzed off-line using ImageJ. CNR measurements showed no differences between systems, whereas the contrast-detail analysis and edge blurring characterization showed relatively low performance of Philips Clarity systems compared to Siemens and Philips non-Clarity systems. Conversely, the modulation transfer function showed that the limiting spatial resolution was higher for the Philips systems relative to the Siemens suite. However, with the DSA phantom the performance of Siemens and Philips Clarity-systems was similar. In conclusion, depending on the image quality phantom used for comparing different systems, the results may differ and therefore, quantitative metrics derived from standard fluoroscopy phantoms lack the discriminatory ability to assess vendor-specific advancements in interventional fluoroscopy systems.

  12. Quantitative Reasoning in Environmental Science: Rasch Measurement to Support QR Assessment

    Directory of Open Access Journals (Sweden)

    Robert L. Mayes

    2015-07-01

    Full Text Available The ability of middle and high school students to reason quantitatively within the context of environmental science was investigated. A quantitative reasoning (QR learning progression, with associated QR assessments in the content areas of biodiversity, water, and carbon, was developed based on three QR progress variables: quantification act, quantitative interpretation, and quantitative modeling. Diagnostic instruments were developed specifically for the progress variable quantitative interpretation (QI, each consisting of 96 Likert-scale items. Each content version of the instrument focused on three scale levels (macro scale, micro scale, and landscape scale and four elements of QI identified in prior research (trend, translation, prediction, and revision. The QI assessments were completed by 362, 6th to 12th grade students in three U.S. states. Rasch (1960/1980 measurement was used to determine item and person measures for the QI instruments, both to examine validity and reliability characteristics of the instrument administration and inform the evolution of the learning progression. Rasch methods allowed identification of several QI instrument revisions, including modification of specific items, reducing number of items to avoid cognitive fatigue, reconsidering proposed item difficulty levels, and reducing Likert scale to 4 levels. Rasch diagnostics also indicated favorable levels of instrument reliability and appropriate targeting of item abilities to student abilities for the majority of participants. A revised QI instrument is available for STEM researchers and educators.

  13. Rapid and Quantitative Assessment of Cancer Treatment Response Using In Vivo Bioluminescence Imaging

    Directory of Open Access Journals (Sweden)

    Alnawaz Rehemtulla

    2000-01-01

    Full Text Available Current assessment of orthotopic tumor models in animals utilizes survival as the primary therapeutic end point. In vivo bioluminescence imaging (BLI is a sensitive imaging modality that is rapid and accessible, and may comprise an ideal tool for evaluating antineoplastic therapies [1 ]. Using human tumor cell lines constitutively expressing luciferase, the kinetics of tumor growth and response to therapy have been assessed in intraperitoneal [2], subcutaneous, and intravascular [3] cancer models. However, use of this approach for evaluating orthotopic tumor models has not been demonstrated. In this report, the ability of BLI to noninvasively quantitate the growth and therapeuticinduced cell kill of orthotopic rat brain tumors derived from 9L gliosarcoma cells genetically engineered to stably express firefly luciferase (9LLuc was investigated. Intracerebral tumor burden was monitored over time by quantitation of photon emission and tumor volume using a cryogenically cooled CCD camera and magnetic resonance imaging (MRI, respectively. There was excellent correlation (r=0.91 between detected photons and tumor volume. A quantitative comparison of tumor cell kill determined from serial MRI volume measurements and BLI photon counts following 1,3-bis(2-chloroethyl-1-nitrosourea (BCNU treatment revealed that both imaging modalities yielded statistically similar cell kill values (P=.951. These results provide direct validation of BLI imaging as a powerful and quantitative tool for the assessment of antineoplastic therapies in living animals.

  14. Relationship between Plaque Echo, Thickness and Neovascularization Assessed by Quantitative and Semi-quantitative Contrast-Enhanced Ultrasonography in Different Stenosis Groups.

    Science.gov (United States)

    Song, Yan; Feng, Jun; Dang, Ying; Zhao, Chao; Zheng, Jie; Ruan, Litao

    2017-12-01

    The aim of this study was to determine the relationship between plaque echo, thickness and neovascularization in different stenosis groups using quantitative and semi-quantitative contrast-enhanced ultrasound (CEUS) in patients with carotid atherosclerosis plaque. A total of 224 plaques were divided into mild stenosis (Quantitative and semi-quantitative methods were used to assess plaque neovascularization and determine the relationship between plaque echo, thickness and neovascularization. Correlation analysis revealed no relationship of neovascularization with plaque echo in the groups using either quantitative or semi-quantitative methods. Furthermore, there was no correlation of neovascularization with plaque thickness using the semi-quantitative method. The ratio of areas under the curve (RAUC) was negatively correlated with plaque thickness (r = -0.317, p = 0.001) in the mild stenosis group. With the quartile method, plaque thickness of the mild stenosis group was divided into four groups, with significant differences between the 1.5-2.2 mm and ≥3.5 mm groups (p = 0.002), 2.3-2.8 mm and ≥3.5 mm groups (p quantitative and quantitative CEUS methods characterizing neovascularization of plaque are equivalent with respect to assessing relationships between neovascularization, echogenicity and thickness. However, the quantitative method could fail for plaque <3.5 mm because of motion artifacts. Copyright © 2017 World Federation for Ultrasound in Medicine and Biology. Published by Elsevier Inc. All rights reserved.

  15. Comparison of exercise radionuclide angiography with thallium SPECT imaging for detection of significant narrowing of the left circumflex coronary artery

    International Nuclear Information System (INIS)

    Dilsizian, V.; Perrone-Filardi, P.; Cannon, R.O. III; Freedman, N.M.; Bacharach, S.L.; Bonow, R.O.

    1991-01-01

    Although quantitation of exercise thallium tomograms has enhanced the noninvasive diagnosis and localization of coronary artery disease, the detection of stenosis of the left circumflex coronary artery remains suboptimal. Because posterolateral regional wall motion during exercise is well assessed by radionuclide angiography, this study determined whether regional dysfunction of the posterolateral wall during exercise radionuclide angiography is more sensitive in identifying left circumflex disease than thallium perfusion abnormalities assessed by single-photon emission computed tomography (SPECT). One hundred ten consecutive patients with CAD were studied, of whom 70 had a significant stenosis of the left circumflex coronary artery or a major obtuse marginal branch. Both regional function and segmental thallium activity of the posterolateral wall were assessed using visual and quantitative analysis. Left ventricular regional function was assessed objectively by dividing the left ventricular region of interest into 20 sectors; the 8 sectors corresponding to the posterolateral free wall were used to assess function in the left circumflex artery distribution. Similarly, using circumferential profile analysis of short-axis thallium tomograms, left ventricular myocardial activity was subdivided into 64 sectors; the 16 sectors corresponding to the posterolateral region were used to assess thallium perfusion abnormalities in the left circumflex artery territory. Qualitative posterolateral wall motion analysis detected 76% of patients with left circumflex coronary artery stenosis, with a specificity of 83%, compared with only 44% by qualitative thallium tomography (p less than 0.001) and a specificity of 92%

  16. New method of digital angiography

    International Nuclear Information System (INIS)

    Hashiya, Junichi; Korenaga, Takeo; Sakurai, Kenji; Sakai, Fumikazu; Kato, Hisatoyo; Takano, Masao.

    1982-01-01

    New experience of digital angiography using Fuji Intelligent Diagnostic X-ray System was reported. The system utilizes newly developed high sensitivity imaging plate in conjunction with computerized image processor instead of image intensifier-TV series, thus drastically improving image quality. Initial clinical trial was made in 46 cases including intravenous digital subtraction angiography and transcatheter digital arteriography. The advantages of this method were summerized as: 1. better resolution, 2. wider field size, 3. more sophisticated image manipulation program. (author)

  17. A novel iris transillumination grading scale allowing flexible assessment with quantitative image analysis and visual matching.

    Science.gov (United States)

    Wang, Chen; Brancusi, Flavia; Valivullah, Zaheer M; Anderson, Michael G; Cunningham, Denise; Hedberg-Buenz, Adam; Power, Bradley; Simeonov, Dimitre; Gahl, William A; Zein, Wadih M; Adams, David R; Brooks, Brian

    2018-01-01

    To develop a sensitive scale of iris transillumination suitable for clinical and research use, with the capability of either quantitative analysis or visual matching of images. Iris transillumination photographic images were used from 70 study subjects with ocular or oculocutaneous albinism. Subjects represented a broad range of ocular pigmentation. A subset of images was subjected to image analysis and ranking by both expert and nonexpert reviewers. Quantitative ordering of images was compared with ordering by visual inspection. Images were binned to establish an 8-point scale. Ranking consistency was evaluated using the Kendall rank correlation coefficient (Kendall's tau). Visual ranking results were assessed using Kendall's coefficient of concordance (Kendall's W) analysis. There was a high degree of correlation among the image analysis, expert-based and non-expert-based image rankings. Pairwise comparisons of the quantitative ranking with each reviewer generated an average Kendall's tau of 0.83 ± 0.04 (SD). Inter-rater correlation was also high with Kendall's W of 0.96, 0.95, and 0.95 for nonexpert, expert, and all reviewers, respectively. The current standard for assessing iris transillumination is expert assessment of clinical exam findings. We adapted an image-analysis technique to generate quantitative transillumination values. Quantitative ranking was shown to be highly similar to a ranking produced by both expert and nonexpert reviewers. This finding suggests that the image characteristics used to quantify iris transillumination do not require expert interpretation. Inter-rater rankings were also highly similar, suggesting that varied methods of transillumination ranking are robust in terms of producing reproducible results.

  18. E-learn Computed Tomographic Angiography

    DEFF Research Database (Denmark)

    Havsteen, Inger; Christensen, Anders; Nielsen, Jens K

    2012-01-01

    BACKGROUND: Computed tomographic angiography (CTA) is widely available in emergency rooms to assess acute stroke patients. To standardize readings and educate new readers, we developed a 3-step e-learning tool based on the test-teach-retest methodology in 2 acute stroke scenarios: vascular...... the teaching segment; the test size was 40% of the teaching segment size. We assessed diagnostic accuracy and readers' confidence. Results were compared using the Wilcoxon rank sum test. RESULTS: Four neurologic consultants and four radiologic residents completed the program. The vascular occlusion teaching...

  19. Quantitative histological assessment of hepatic ischamia-reperfusion injuries following ischemic pre- and post-conditioning in the rat liver

    DEFF Research Database (Denmark)

    Knudsen, Anders Riegels; Kannerup, Anne-Sofie; Grønbæk, Henning

    2013-01-01

    Quantitative histological assessment of hepatic ischamia-reperfusion injuries following ischemic pre- and post-conditioning in the rat liver......Quantitative histological assessment of hepatic ischamia-reperfusion injuries following ischemic pre- and post-conditioning in the rat liver...

  20. Comparison of magnetic resonance angiography and conventional angiography in sickle cell disease: clinical significance and realibility

    International Nuclear Information System (INIS)

    Kandeel, A.Y.; Zimmerman, R.A.; Ohene-Frempong, K.

    1996-01-01

    We retrospectively reviewed the medical records and conventional angiograms of 21 patients with known sickle cell disease, who underwent a total of 50 magnetic resonance imaging (MRI) and magnetic resonance angiography (MRA) studies. MRA and conventional angiography were assessed separately for evidence of stenosis or occulusion. Follow up MRI/MRA studies were also assessed for evidence of progression, regression or stability of the disease in these patients. In the carotid circulation, MRA made the correct diagnosis in 85% of the vessels evaluated with a sensitivity of 80.5% and a specificity of 94%. MRA was also found to show evidence of disease progression, more often than did MRI or the clinical condition of the patients. (orig.)

  1. Current Understanding of the Pathophysiology of Myocardial Fibrosis and Its Quantitative Assessment in Heart Failure

    Directory of Open Access Journals (Sweden)

    Tong Liu

    2017-04-01

    Full Text Available Myocardial fibrosis is an important part of cardiac remodeling that leads to heart failure and death. Myocardial fibrosis results from increased myofibroblast activity and excessive extracellular matrix deposition. Various cells and molecules are involved in this process, providing targets for potential drug therapies. Currently, the main detection methods of myocardial fibrosis rely on serum markers, cardiac magnetic resonance imaging, and endomyocardial biopsy. This review summarizes our current knowledge regarding the pathophysiology, quantitative assessment, and novel therapeutic strategies of myocardial fibrosis.

  2. Fixing the cracks in the crystal ball: A maturity model for quantitative risk assessment

    International Nuclear Information System (INIS)

    Rae, Andrew; Alexander, Rob; McDermid, John

    2014-01-01

    Quantitative risk assessment (QRA) is widely practiced in system safety, but there is insufficient evidence that QRA in general is fit for purpose. Defenders of QRA draw a distinction between poor or misused QRA and correct, appropriately used QRA, but this distinction is only useful if we have robust ways to identify the flaws in an individual QRA. In this paper we present a comprehensive maturity model for QRA which covers all the potential flaws discussed in the risk assessment literature and in a collection of risk assessment peer reviews. We provide initial validation of the completeness and realism of the model. Our risk assessment maturity model provides a way to prioritise both process development within an organisation and empirical research within the QRA community. - Highlights: • Quantitative risk assessment (QRA) is widely practiced, but there is insufficient evidence that it is fit for purpose. • A given QRA may be good, or it may not – we need systematic ways to distinguish this. • We have created a maturity model for QRA which covers all the potential flaws discussed in the risk assessment literature. • We have provided initial validation of the completeness and realism of the model. • The maturity model can also be used to prioritise QRA research discipline-wide

  3. Study on quantitative risk assessment model of the third party damage for natural gas pipelines based on fuzzy comprehensive assessment

    International Nuclear Information System (INIS)

    Qiu, Zeyang; Liang, Wei; Lin, Yang; Zhang, Meng; Wang, Xue

    2017-01-01

    As an important part of national energy supply system, transmission pipelines for natural gas are possible to cause serious environmental pollution, life and property loss in case of accident. The third party damage is one of the most significant causes for natural gas pipeline system accidents, and it is very important to establish an effective quantitative risk assessment model of the third party damage for reducing the number of gas pipelines operation accidents. Against the third party damage accident has the characteristics such as diversity, complexity and uncertainty, this paper establishes a quantitative risk assessment model of the third party damage based on Analytic Hierarchy Process (AHP) and Fuzzy Comprehensive Evaluation (FCE). Firstly, risk sources of third party damage should be identified exactly, and the weight of factors could be determined via improved AHP, finally the importance of each factor is calculated by fuzzy comprehensive evaluation model. The results show that the quantitative risk assessment model is suitable for the third party damage of natural gas pipelines and improvement measures could be put forward to avoid accidents based on the importance of each factor. (paper)

  4. Magnetic resonance angiography vs. angiography in tetralogy of Fallot.

    Science.gov (United States)

    Rao, Uppalapati Venkateswara; Vanajakshamma, Velam; Rajasekhar, Durgaprasad; Lakshmi, Amancharla Yadagiri; Reddy, Reddivari Niranjan

    2013-08-01

    : To determine whether gadolinium-enhanced three-dimensional magnetic resonance angiography can provide a noninvasive alternative to diagnostic catheterization for evaluation of pulmonary artery anatomy in tetralogy of Fallot. Thirty-five consecutive patients with tetralogy of Fallot, who attended the cardiology outpatient department between January 2008 and December 2009, were included in the study. There were 21 males and 14 females, with a mean age of 9 ± 4.15 years (range, 3-21 years). Thirty-two patients had tetralogy of Fallot with varying severities of valvular and infundibular stenosis. Three patients had tetralogy of Fallot with pulmonary atresia. All patients underwent both cardiac catheterization with X-ray angiography and 3-dimensional magnetic resonance angiography within one month. Measurements of right and left pulmonary arteries and aortopulmonary collaterals were equal by both methods. There was a good correlation between magnetic resonance angiography and catheterization measurements of branch pulmonary arteries. Gadolinium-enhanced three-dimensional magnetic resonance angiography can be used as a reliable noninvasive alternative to X-ray cineangiography for delineation of pulmonary arterial anatomy in sick infants and young children, obviating the need for catheterization.

  5. Development and Assessment of Modules to Integrate Quantitative Skills in Introductory Biology Courses.

    Science.gov (United States)

    Hoffman, Kathleen; Leupen, Sarah; Dowell, Kathy; Kephart, Kerrie; Leips, Jeff

    2016-01-01

    Redesigning undergraduate biology courses to integrate quantitative reasoning and skill development is critical to prepare students for careers in modern medicine and scientific research. In this paper, we report on the development, implementation, and assessment of stand-alone modules that integrate quantitative reasoning into introductory biology courses. Modules are designed to improve skills in quantitative numeracy, interpreting data sets using visual tools, and making inferences about biological phenomena using mathematical/statistical models. We also examine demographic/background data that predict student improvement in these skills through exposure to these modules. We carried out pre/postassessment tests across four semesters and used student interviews in one semester to examine how students at different levels approached quantitative problems. We found that students improved in all skills in most semesters, although there was variation in the degree of improvement among skills from semester to semester. One demographic variable, transfer status, stood out as a major predictor of the degree to which students improved (transfer students achieved much lower gains every semester, despite the fact that pretest scores in each focus area were similar between transfer and nontransfer students). We propose that increased exposure to quantitative skill development in biology courses is effective at building competency in quantitative reasoning. © 2016 K. Hoffman, S. Leupen, et al. CBE—Life Sciences Education © 2016 The American Society for Cell Biology. This article is distributed by The American Society for Cell Biology under license from the author(s). It is available to the public under an Attribution–Noncommercial–Share Alike 3.0 Unported Creative Commons License (http://creativecommons.org/licenses/by-nc-sa/3.0).

  6. The Quantitative Reasoning for College Science (QuaRCS) Assessment in non-Astro 101 Courses

    Science.gov (United States)

    Kirkman, Thomas W.; Jensen, Ellen

    2016-06-01

    The innumeracy of American students and adults is a much lamented educational problem. The quantitative reasoning skills of college students may be particularly addressed and improved in "general education" science courses like Astro 101. Demonstrating improvement requires a standardized instrument. Among the non-proprietary instruments the Quantitative Literacy and Reasoning Assessment[1] (QRLA) and the Quantitative Reasoning for College Science (QuaRCS) Assessment[2] stand out.Follette et al. developed the QuaRCS in the context of Astro 101 at University of Arizona. We report on QuaRCS results in different contexts: pre-med physics and pre-nursing microbiology at a liberal arts college. We report on the mismatch between students' contemporaneous report of a question's difficulty and the actual probability of success. We report correlations between QuaRCS and other assessments of overall student performance in the class. We report differences in attitude towards mathematics in these two different but health-related student populations .[1] QLRA, Gaze et al., 2014, DOI: http://dx.doi.org/10.5038/1936-4660.7.2.4[2] QuaRCS, Follette, et al., 2015, DOI: http://dx.doi.org/10.5038/1936-4660.8.2.2

  7. Segmented swept source optical coherence tomography angiography assessment of the perifoveal vasculature in patients with X-linked juvenile retinoschisis: a serial case report

    Directory of Open Access Journals (Sweden)

    Stringa F

    2017-10-01

    Full Text Available Francesco Stringa,1,2 Emmanouli Tsamis,1,3 Alessandro Papayannis,1 Katarzyna Chwiejczak,1 Assad Jalil,2 Susmito Biswas,1,2,4 Hassan Ahmad,1 Paulo Eduardo Stanga1,2,4 1Manchester Vision Regeneration (MVR at NIHR/Wellcome Trust Manchester Clinical Research Facility, 2Manchester Royal Eye Hospital, Central Manchester University Hospitals NHS Foundation Trust, Manchester Academic Health Science Centre, 3Division of Pharmacy and Optometry, School of Health Sciences, 4Division of Evolution and Genomic Sciences, School of Biological Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester Academic Health Science Centre, Manchester, UK Purpose: To describe perifoveal microvascular changes occurring in X-linked juvenile retinoschisis (XLRS using swept source optical coherence tomography angiography (SS OCTA.Patients and methods: This is a serial case report of three patients. Retrospective data of patients affected by XLRS were collected. Structural optical coherence tomography (OCT and color fundus photography (CFPh were carried out with Topcon® OCT 2000 3D OCT as part of the standard care. Two patients were imaged on Topcon Atlantis® SS OCTA and one on Topcon Triton® SS OCTA. SS OCTA images were acquired using the 3 × 3 mm fovea-centered cubes scanning protocol. Analysis of both perifoveal superficial vascular plexus (pSVP and perifoveal deep vascular plexus (pDVP was performed by two observers after automated segmentation.Results: Four eyes of three males (mean age 14 ± 3.8 years were analyzed. All eyes showed foveoschisis on CFPh images. OCT B-scans of three eyes showed schistic cysts in the ganglion cell layer, inner nuclear layer (INL and outer nuclear layer (ONL; in one eye, cysts were depicted in INL and ONL only. In two eyes, SS OCTA showed abnormal foveal avascular zone (FAZ shape in the pSVP, and in the other two, FAZ shape was abnormal in both plexuses. In all eyes, retinal vascular abnormalities (ie

  8. Helical CT angiography : A single imaging modality to evaluate a live renal donor

    Directory of Open Access Journals (Sweden)

    Waheed Zaman

    2002-01-01

    Conclusions: Helical CT angiography, which is highly specific for arterial and venous anatomy as well as other anatomical and functional details, can become the single imaging modality for preoperative assessment of poten-tial donors in place of conventional angiography and IVU. CTA, being minimally invasive and cost effective, is well accepted by a normal healthy donor

  9. Renal artery digital-substraction angiography. An outpatient investigation for renovascular hypertension

    International Nuclear Information System (INIS)

    Jackson, B.; Dugdale, L.

    1985-01-01

    The adequacy and convenience of the digital-substraction angiographic procedure by means of a Diasonics DF100 as an investigation in renovascular disease were assessed in 82 renal artery studies. The major advantage of digital subtraction angiography of the renal artery over conventional angiography is that it can be performed on an outpatient basis

  10. The outcome of angiography in patients with Raynaud's phenomenon: an unexpected role for atherosclerosis and hypercholesterolemia

    NARCIS (Netherlands)

    van Vugt, R. M.; Kater, L.; Dijkstra, P. F.; Schardijn, G. H.; Kastelein, J. J.; Bijlsma, J. W.

    2003-01-01

    Upper extremity angiography can make an important contribution to the diagnosis in vasculopathy. The present study was designed to assess the diagnostic role of upper extremity angiography in patients with disturbed circulation of the hand, according to a standardised protocol. The study was carried

  11. Quantitative assessment of morphology, T1ρ, and T2 of shoulder cartilage using MRI

    International Nuclear Information System (INIS)

    Nardo, Lorenzo; Carballido-Gamio, Julio; Tang, Solomon; Lai, Andrew; Krug, Roland

    2016-01-01

    The aim of this study was to assess the feasibility of quantifying shoulder cartilage morphology and relaxometry in a clinically feasible scan time comparing different pulse sequences and assessing their reproducibility at 3 Tesla. Three pulse sequences were compared for morphological assessments of shoulder cartilage thickness and volume (SPGR, MERGE, FIESTA), while a combined T1ρ-T2 sequence was optimized for relaxometry measurements. The shoulders of six healthy subjects were scanned twice with repositioning, and the cartilage was segmented and quantified. The degree of agreement between the three morphological sequences was assessed using Bland-Altman plots, while the morphological and relaxometry reproducibility were assessed with root-mean-square coefficients of variation (RMS-CVs) Bland-Altman plots indicated good levels of agreement between the morphological assessments of the three sequences. The reproducibility of morphological assessments yielded RMS-CVs between 4.0 and 17.7 %. All sequences correlated highly (R > 0.9) for morphologic assessments with no statistically significant differences. For relaxometry assessments of humeral cartilage, RMS-CVs of 6.4 and 10.6 % were found for T1ρ and T2, respectively. The assessment of both cartilage morphology and relaxometry is feasible in the shoulder with SPGR, humeral head, and T1ρ being the more reproducible morphological sequence, anatomic region, and quantitative sequence, respectively. (orig.)

  12. 3D Deep Learning Angiography (3D-DLA) from C-arm Conebeam CT.

    Science.gov (United States)

    Montoya, J C; Li, Y; Strother, C; Chen, G-H

    2018-03-22

    Deep learning is a branch of artificial intelligence that has demonstrated unprecedented performance in many medical imaging applications. Our purpose was to develop a deep learning angiography method to generate 3D cerebral angiograms from a single contrast-enhanced C-arm conebeam CT acquisition in order to reduce image artifacts and radiation dose. A set of 105 3D rotational angiography examinations were randomly selected from an internal data base. All were acquired using a clinical system in conjunction with a standard injection protocol. More than 150 million labeled voxels from 35 subjects were used for training. A deep convolutional neural network was trained to classify each image voxel into 3 tissue types (vasculature, bone, and soft tissue). The trained deep learning angiography model was then applied for tissue classification into a validation cohort of 8 subjects and a final testing cohort of the remaining 62 subjects. The final vasculature tissue class was used to generate the 3D deep learning angiography images. To quantify the generalization error of the trained model, we calculated the accuracy, sensitivity, precision, and Dice similarity coefficients for vasculature classification in relevant anatomy. The 3D deep learning angiography and clinical 3D rotational angiography images were subjected to a qualitative assessment for the presence of intersweep motion artifacts. Vasculature classification accuracy and 95% CI in the testing dataset were 98.7% (98.3%-99.1%). No residual signal from osseous structures was observed for any 3D deep learning angiography testing cases except for small regions in the otic capsule and nasal cavity compared with 37% (23/62) of the 3D rotational angiographies. Deep learning angiography accurately recreated the vascular anatomy of the 3D rotational angiography reconstructions without a mask. Deep learning angiography reduced misregistration artifacts induced by intersweep motion, and it reduced radiation exposure

  13. Development of a quantitative safety assessment method for nuclear I and C systems including human operators

    International Nuclear Information System (INIS)

    Kim, Man Cheol

    2004-02-01

    Conventional PSA (probabilistic safety analysis) is performed in the framework of event tree analysis and fault tree analysis. In conventional PSA, I and C systems and human operators are assumed to be independent for simplicity. But, the dependency of human operators on I and C systems and the dependency of I and C systems on human operators are gradually recognized to be significant. I believe that it is time to consider the interdependency between I and C systems and human operators in the framework of PSA. But, unfortunately it seems that we do not have appropriate methods for incorporating the interdependency between I and C systems and human operators in the framework of Pasa. Conventional human reliability analysis (HRA) methods are not developed to consider the interdependecy, and the modeling of the interdependency using conventional event tree analysis and fault tree analysis seem to be, event though is does not seem to be impossible, quite complex. To incorporate the interdependency between I and C systems and human operators, we need a new method for HRA and a new method for modeling the I and C systems, man-machine interface (MMI), and human operators for quantitative safety assessment. As a new method for modeling the I and C systems, MMI and human operators, I develop a new system reliability analysis method, reliability graph with general gates (RGGG), which can substitute conventional fault tree analysis. RGGG is an intuitive and easy-to-use method for system reliability analysis, while as powerful as conventional fault tree analysis. To demonstrate the usefulness of the RGGG method, it is applied to the reliability analysis of Digital Plant Protection System (DPPS), which is the actual plant protection system of Ulchin 5 and 6 nuclear power plants located in Republic of Korea. The latest version of the fault tree for DPPS, which is developed by the Integrated Safety Assessment team in Korea Atomic Energy Research Institute (KAERI), consists of 64

  14. A methodology for the quantitative risk assessment of major accidents triggered by seismic events.

    Science.gov (United States)

    Antonioni, Giacomo; Spadoni, Gigliola; Cozzani, Valerio

    2007-08-17

    A procedure for the quantitative risk assessment of accidents triggered by seismic events in industrial facilities was developed. The starting point of the procedure was the use of available historical data to assess the expected frequencies and the severity of seismic events. Available equipment-dependant failure probability models (vulnerability or fragility curves) were used to assess the damage probability of equipment items due to a seismic event. An analytic procedure was subsequently developed to identify, evaluate the credibility and finally assess the expected consequences of all the possible scenarios that may follow the seismic events. The procedure was implemented in a GIS-based software tool in order to manage the high number of event sequences that are likely to be generated in large industrial facilities. The developed methodology requires a limited amount of additional data with respect to those used in a conventional QRA, and yields with a limited effort a preliminary quantitative assessment of the contribution of the scenarios triggered by earthquakes to the individual and societal risk indexes. The application of the methodology to several case-studies evidenced that the scenarios initiated by seismic events may have a relevant influence on industrial risk, both raising the overall expected frequency of single scenarios and causing specific severe scenarios simultaneously involving several plant units.

  15. A framework for quantitative assessment of impacts related to energy and mineral resource development

    Science.gov (United States)

    Haines, Seth S.; Diffendorfer, James; Balistrieri, Laurie S.; Berger, Byron R.; Cook, Troy A.; Gautier, Donald L.; Gallegos, Tanya J.; Gerritsen, Margot; Graffy, Elisabeth; Hawkins, Sarah; Johnson, Kathleen; Macknick, Jordan; McMahon, Peter; Modde, Tim; Pierce, Brenda; Schuenemeyer, John H.; Semmens, Darius; Simon, Benjamin; Taylor, Jason; Walton-Day, Katherine

    2013-01-01

    Natural resource planning at all scales demands methods for assessing the impacts of resource development and use, and in particular it requires standardized methods that yield robust and unbiased results. Building from existing probabilistic methods for assessing the volumes of energy and mineral resources, we provide an algorithm for consistent, reproducible, quantitative assessment of resource development impacts. The approach combines probabilistic input data with Monte Carlo statistical methods to determine probabilistic outputs that convey the uncertainties inherent in the data. For example, one can utilize our algorithm to combine data from a natural gas resource assessment with maps of sage grouse leks and piñon-juniper woodlands in the same area to estimate possible future habitat impacts due to possible future gas development. As another example: one could combine geochemical data and maps of lynx habitat with data from a mineral deposit assessment in the same area to determine possible future mining impacts on water resources and lynx habitat. The approach can be applied to a broad range of positive and negative resource development impacts, such as water quantity or quality, economic benefits, or air quality, limited only by the availability of necessary input data and quantified relationships among geologic resources, development alternatives, and impacts. The framework enables quantitative evaluation of the trade-offs inherent in resource management decision-making, including cumulative impacts, to address societal concerns and policy aspects of resource development.

  16. Determination of left ventricular heart volume by fast MRI in breath-hold technique: how different are quantitative ventricular angiography, quantitative MRI, and visual echocardiography?; Linksventrikulaere Herzvoluminabestimmung mittels schneller MRT in Atemanhaltetechnik: Wie unterschiedlich sind quantitativer Herzkatheter, quantitativer MRT und visuelle Echokardiographie?

    Energy Technology Data Exchange (ETDEWEB)

    Rominger, M.B.; Bachmann, G.F. [Giessen Univ. (Germany). Diagnostische Radiologie; Kerckhoff-Klinik GmbH, Bad Nauheim (Germany). Projektgruppe Magnetresonanztomographie; Pabst, W. [Giessen Univ. (Germany). Inst. fuer Medizinische Informatik; Ricken, W.W. [Kerckhoff-Klinik GmbH, Bad Nauheim (Germany). Projektgruppe Magnetresonanztomographie; Dinkel, H.P.; Rau, W.S. [Giessen Univ. (Germany). Diagnostische Radiologie

    2000-01-01

    Goal: Comparison of fast MRI, echocardiography (Echo), and ventricular angiography (Cath) in the assessment of left ventricular global function. Methods: Fast MRI in short axis plane, biplane Cath, and 2D Echo were performed in 62 patients [35 coronary artery diseases, 16 acquired valvular diseases (VD), 9 dilated cardiomyopathies (DCM), 1 congenital heart disease and 1 heart transplantation]. Enddiastolic (EDV), endsystolic (ESV), stroke volumes (SV), cardiac output (CO), and ejection fraction (EF) were compared in MRI and Cath. EF was visually estimated in 2D Echo by an experienced observer. Results: In comparison to MRI, Cath overestimated EF by 8.4%, and Echo underestimated EF by 5.6%. The limits of agreement between MRI and Cath in EF were {+-}23.8%, between MRI and Echo {+-}18%, and between Echo and Cath {+-}19.4%. Significant differences were found between Cath and MRI in EDV, SV, and CO, but not for ESV. The best agreement in EF was found in the group with DCM, the worst in the group with VD. Conclusion: Important systemic and random errors were found in the comparison of MRI, Echo, and Cath. For therapy decision and follow-up, the methods should not be exchanged unscrupulously. (orig.) [German] Ziel: Methodenvergleich von schneller Magnetresonanztomographie (MRT), Echokardiographie (Echo) und Herzkatheter (HK) in der Bestimmung linksventrikulaerer globaler Funktionsparameter. Material und Methoden: Bei 62 Patienten (35 koronare Herzerkrankungen, 16 Herzklappenvitien (KV), 9 idiopathische dilatative Kardiomyopathien (DCM), 1 kongenitale Herzerkrankung und 1 Herzktransplantation) wurde ein Methodenvergleich zwischen schneller Cine MRT im Kurzachsenschnitt, biplanarem HK und 2D Echo durchgefuehrt. Verglichen wurden in MRT und HK linksventrikulaeres enddiastolisches (EDV) und endsystolisches Volumen (ESV), Schlagvolumen (SV), Herzzeitvolumen (HZV) und Ejektionsfraktion (EF). In der Echo wurde die EF visuell durch einen erfahrenen Untersucher bestimmt

  17. Qualitative assessment of contrast-enhanced magnetic resonance angiography using breath-hold and non-breath-hold techniques in the portal venous system

    Science.gov (United States)

    Goo, Eun-Hoe; Kim, Sun-Ju; Dong, Kyung-Rae; Kim, Kwang-Choul; Chung,