ORCID Profile
0000-0002-6577-0407
Current Organisations
Aristotle University of Thessaloniki
,
Erasmus Medisch Centrum
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Publisher: Springer Science and Business Media LLC
Date: 07-10-2012
DOI: 10.1007/S00330-012-2663-3
Abstract: To compare the diagnostic performance and radiation exposure of 128-slice dual-source CT coronary angiography (CTCA) protocols to detect coronary stenosis with more than 50 % lumen obstruction. We prospectively included 459 symptomatic patients referred for CTCA. Patients were randomized between high-pitch spiral vs. narrow-window sequential CTCA protocols (heart rate below 65 bpm, group A), or between wide-window sequential vs. retrospective spiral protocols (heart rate above 65 bpm, group B). Diagnostic performance of CTCA was compared with quantitative coronary angiography in 267 patients. In group A (231 patients, 146 men, mean heart rate 58 ± 7 bpm), high-pitch spiral CTCA yielded a lower per-segment sensitivity compared to sequential CTCA (89 % vs. 97 %, P = 0.01). Specificity, PPV and NPV were comparable (95 %, 62 %, 99 % vs. 96 %, 73 %, 100 %, P > 0.05) but radiation dose was lower (1.16 ± 0.60 vs. 3.82 ± 1.65 mSv, P 0.05). Radiation dose of sequential CTCA was lower compared to retrospective CTCA (6.12 ± 2.58 vs. 8.13 ± 4.52 mSv, P < 0.001). Diagnostic performance was comparable in both groups. Sequential CTCA should be used in patients with regular heart rates using 128-slice dual-source CT, providing optimal diagnostic accuracy with as low as reasonably achievable (ALARA) radiation dose.
Publisher: Wiley
Date: 16-06-2011
DOI: 10.1002/CCD.22958
Abstract: To describe a method for the estimation of transaortic flow from multidetector computer tomography (MDCT). Cardiac MDCT may not allow instantaneous flow measurement yet the components of flow, namely, volume change over time and lumenal area are recorded. In 36 patients, the transaortic flow velocity was determined on transthoracic echocardiography and also with cardiac MDCT as follows: On MDCT an axial orientation through the aortic root was obtained so that the nadir of all three aortic leaflets could be seen simultaneously in one axial image. Aortic valve area (AVA) was determined by planimetry and left ventricular volumes by endocardial border mapping at every 5% increment of the RR intervals. Flow velocity was then calculated as the incremental ejection volume ÷ duration of the increment ÷ AVA. The transthoracic echocardiography (TTE) peak velocity and MDCT peak velocity were highly correlated (r = 0.75, P < 0.01). Transaortic peak velocity was higher when measured by MDCT as compared to TTE, with respectively a median [IQ-range] of 4.5 [2.9-5.3] and 4.0 [3.0-4.6], P < 0.01. For the diagnosis of severe aortic stenosis greater concordance with TTE peak velocity was seen with MDCT peak velocity (sensitivity 100%, specificity 76%) than with MDCT AVA (sensitivity 74%, specificity 76%). We show for the first time that transaortic flow velocity can be estimated by dual-source MDCT and has a better sensitivity for the detection of severe aortic stenosis than AVA planimetry when compared to the gold standard of TTE peak flow velocity.
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 2014
DOI: 10.1161/CIRCIMAGING.112.000277
Abstract: Coronary lesions with a diameter narrowing ≥50% on visual computed tomographic coronary angiography (CTCA) are generally considered for referral to invasive coronary angiography. However, similar to invasive coronary angiography, visual CTCA is often inaccurate in detecting functionally significant coronary lesions. We sought to compare the diagnostic performance of quantitative CTCA with visual CTCA for the detection of functionally significant coronary lesions using fractional flow reserve (FFR) as the reference standard. CTCA and FFR measurements were obtained in 99 symptomatic patients. In total, 144 coronary lesions detected on CTCA were visually graded for stenosis severity. Quantitative CTCA measurements included lesion length, minimal area diameter, % area stenosis, minimal lumen diameter, % diameter stenosis, and plaque burden [(vessel area−lumen area)/vessel area×100]. Optimal cutoff values of CTCA-derived parameters were determined, and their diagnostic accuracy for the detection of flow-limiting coronary lesions (FFR ≤0.80) was compared with visual CTCA. FFR was ≤0.80 in 54 of 144 (38%) coronary lesions. Optimal cutoff values to predict flow-limiting coronary lesion were 10 mm for lesion length, 1.8 mm 2 for minimal area diameter, 73% for % area stenosis, 1.5 mm for minimal lumen diameter, 48% for % diameter stenosis, and 76% for plaque burden. No significant difference in sensitivity was found between visual CTCA and quantitative CTCA parameters ( P .05). The specificity of visual CTCA (42% 95% confidence interval [CI], 31%–54%) was lower than that of minimal area diameter (68% 95% CI, 57%–77% P =0.001), % area stenosis (76% 95% CI, 65%–84% P .001), minimal lumen diameter (67% 95% CI, 55%–76% P =0.001), % diameter stenosis (72% 95% CI, 62%–80% P .001), and plaque burden (63% 95% CI, 52%–73% P =0.004). The specificity of lesion length was comparable with that of visual CTCA. Quantitative CTCA improves the prediction of functionally significant coronary lesions compared with visual CTCA assessment but remains insufficient. Functional assessment is still required in lesions of moderate stenosis to accurately detect impaired FFR.
Publisher: Europa Digital & Publishing
Date: 09-2011
DOI: 10.4244/EIJV7I5A92
No related grants have been discovered for Stella-Lida Papadopoulou.