[Show abstract][Hide abstract] ABSTRACT: The aims of this study were to assess the prevalence of noncalcified coronary plaques in asymptomatic patients and to investigate the risk factors.
In this study, 584 patients were recruited prospectively. Patients were classified as having low, intermediate, or high pretest likelihoods of coronary artery disease according to the Morise score. Coronary computed tomographic angiography was performed in all patients using a 320-detector row dynamic-volume computed tomographic scanner. Imaging reconstruction was performed, and the postprocessed data were analyzed. Logistic regression analysis was used to evaluate the relationship between risk factors and the presence of noncalcified plaque.
Coronary computed tomographic angiography revealed noncalcified plaques in 38.3% of all patients (224 of 584). The prevalence of noncalcified plaques was significantly higher in patients with calcium scores > 0 (P < .001). Significant differences were found between the degrees of luminal stenosis among patients with low, intermediate, and high pretest likelihoods of coronary artery disease (P = .001), while the prevalence of noncalcified plaques did not differ with the Morise score (P = .08). Noncalcified plaque was associated with hypercholesterolemia (P = .02) and diabetes mellitus (P = .002). Age (P = .47), gender (P = .58), estrogen status (P = .55), smoking (P = .22), hypertension (P = .27), and family history (P = .09) did not differ between patients with and those without noncalcified plaques.
Hypercholesterolemia and diabetes mellitus are high risk factors for the prevalence of noncalcified plaques for asymptomatic patients.
[Show abstract][Hide abstract] ABSTRACT: To evaluate the feasibility of transthoracic Doppler echocardiography to determine the optimal pulsing windows for CT coronary angiography to narrow the pulsing windows further, especially in higher heart rate.
Doppler was performed on 135 patients before CT scanning. For Doppler, the intervals with minimal motion were evaluated during both systole and diastole integrating electrocardiogram (ECG) intervals. For CT scanning, the retrospective ECG-gating was applied and the optimal reconstruction intervals were determined. The accuracy of Doppler analysis to predict the optimal reconstruction intervals was tested. The predicted length of pulsing windows was compared between Doppler analysis and traditional prospective ECG-gating protocol (heart rate≦65 bpm, 60-76%; 66-79 bpm, 30-77%; ≧80 bpm, 31-47%).
According to Doppler analysis, the mean length of intervals with minimal motion in systole was 106.4±39.2 ms and 125.2±92.0 ms in diastole. When the intervals with minimal motion during diastole>90 ms, the optimal reconstruction intervals were located at diastole; otherwise, at systole (P<0.001). The optimal reconstruction intervals in 93.8% (132/135) patients could be predicted accurately by Doppler analysis. If the optimal reconstruction intervals predicted by Doppler were applied as the exposure windows, the mean length of pulsing windows should has been 105.2±69.4 ms (range: 26.9-510.3 ms), which was significantly shorter than that of traditional prospective ECG-gating protocol (232.0±120.2 ms, range: 93.2-427.3 ms, P<0.001).
Doppler can help detecting the optimal pulsing windows accurately. Prospective ECG-gating incorporating Doppler analysis may narrow pulsing windows significantly while maintaining image quality.
No preview · Article · Sep 2011 · European journal of radiology