[Show abstract][Hide abstract] ABSTRACT: In coronary CT angiography (CTA), both high-grade stenoses and total occlusions of a coronary artery may appear as a complete interruption of the contrast-enhanced lumen. Parameters to differentiate between occlusions and stenoses have not been systematically assessed. We evaluated 40 consecutive patients with a lesion demonstrating complete interruption of the contrast-enhanced lumen in coronary CTA and in whom invasive coronary angiography was available. Length of the vessel segment without luminal contrast enhancement; luminal enhancement proximal, in and distal to the lesion; degree of coronary remodelling; and the degree of lesion calcification were assessed by a blinded observer unaware of the invasive angiogram. Mean length of complete occlusions (n = 20; range 4-54 mm; mean 16.6 +/- 3.5 mm) was significantly longer than for high-grade stenoses (n = 20; 2-8 mm; mean 4.6 +/- 1.7 mm, p < 0.001). A lesion length > or = 9 mm was 100% specific and 70% sensitive for an occlusion. No significant differences were found for vessel enhancement in or distal to the lesion, remodelling index or degree of calcification. Lesion length is the only parameter that may differentiate complete occlusions and high-grade stenoses in coronary CTA. For lesions > or = 9 mm, an occlusion is very likely.
European Radiology 07/2008; 18(12):2770-5. · 4.34 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: We describe a rare congenital anomaly in a 49-year-old woman who presented with palpitations and slightly reduced exercise capacity. A double-chambered left ventricle was suspected on echocardiography and confirmed by cardiac computed tomography scanning, cardiac magnet resonance imaging, and invasive angiography.
[Show abstract][Hide abstract] ABSTRACT: Insufficient spatial and temporal resolutions have limited image quality and accuracy of multi-detector CT (MDCT) for coronary artery visualization and detection of stenoses. We assessed the accuracy of a new 16-slice scanner with 370 ms rotation and 0.75 mm collimation for detection of coronary stenoses using an analysis approach based on coronary artery segments.
Fifty consecutive patients scheduled for diagnostic coronary angiography in stable clinical condition and sinus rhythm were enrolled. All patients with a heart rate > 60 b.p.m. received 100 mg atenolol p.o. and up to four doses of 5 mg metoprolol i.v. before the scan. MDCT was performed using 16 x 0.75 mm collimation, 120 kV, and ECG-gated tube current modulation. Ninety millilitres of contrast agent was injected intravenously. MDCT images were visually analysed using the 16-segment coronary artery model of the American Heart Association and compared with invasive, quantitative coronary angiography in a blinded fashion. A significant stenosis was assumed if the diameter reduction was > or = 50%. Mean heart rate was 58 b.p.m. during MDCT. After exclusion of two patients with not fully evaluable data sets, MDCT correctly identified at least one coronary stenosis in all 25 patients with significant coronary lesions in angiography and correctly demonstrated the absence of stenoses in 19/23 patients (sensitivity 100%, specificity 83%). Sensitivity and specificity for all 50 patients were 93 and 83%, respectively. On a per-segment basis, nine coronary segments distal of total occlusions and 128 coronary segments with a reference diameter < 1.5 mm were excluded from the analysis. Twenty-eight of the included 663 segments (4%) were unevaluable due to calcification or motion artefact. In the remaining 635 segments, 50/53 stenoses were detected by MDCT (sensitivity 94%, specificity 96%, negative predictive value 99%, positive predictive value 69%).
Increasing temporal and spatial resolutions of MDCT lead to improved evaluation and diagnostic accuracy for detection of coronary stenoses.
European Heart Journal 10/2005; 26(19):1978-86. · 14.72 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Delayed contrast-enhanced cardiovascular magnetic resonance (DE-CMR) allows assessment of reversibility of myocardial dysfunction. Comparative data to other modalities is scarce. Purpose of this study was to compare DE-CMR and 201Thallium single photon emission computed tomography (SPECT) for prediction of reversible left ventricular (LV) dysfunction in patients with chronic ischaemic heart disease. Fifty-four patients with LV dysfunction (mean ejection fraction (EF) 35 ± 8%) scheduled to undergo myocardial revascularization underwent DE-CMR and SPECT. Cine CMR was performed at baseline and at 8 months follow-up for assessment of regional and global myocardial function. Myocardial viability was determined by the segmental extent of delayed enhancement for DE-CMR, and by quantitative analysis of tracer uptake for SPECT, and was correlated to functional recovery after revascularization. After revascularization, 172 (49%) of 350 dysfunctional segments improved at follow-up cine CMR. Sensitivity and specificity for the prediction of functional recovery was 92 and 88%, respectively, for DE-CMR as compared to 86% (P = 0.4) and 56% (P = 0.001) for SPECT. Global LV function showed an increase of EF > 5% in 22 (41%) patients. The DE-CMR derived viability ratio (dysfunctional but viable myocardium) of 0.46 (sensitivity 91%, specificity 91%) was identified as predictor of increase in EF > 5% (P = 0.02), whereas the corresponding SPECT parameters were not predictive. DE-CMR compares favorably to SPECT for the prediction of regional and global improvement in LV function in the setting of chronic myocardial ischemia.
The International Journal of Cardiovascular Imaging 28(6). · 2.32 Impact Factor