双源CT冠状动脉成像:与64层螺旋CT初步比较

Dual-source CT angiography of the coronary arteries: comparison with 64-slice spiral CT

目的比较双源CT与64层螺旋CT冠状动脉成像的图像质量。方法对100例临床可疑冠心病患者[计为A组,男54例,年龄（57.9±11.3）岁]进行双源CT心电门控增强扫描,对另外100例临床可疑冠心病患者[计为B组,男59例,年龄（58.0±11.1）岁]进行64层螺旋CT心电门控增强扫描。B组患者检查前用β受体阻滞剂控制心率。对两组图像进行质量评分、冠状动脉节段显示率和最佳重建时相分析。结果A组的心率显著高于B组,分别是（71±12）次/min,（61±6）次/min,P〈0.05,两组的图像质量评分差异无显著性,分别是1.31±0.53和1.25±0.50,P〉0.05。A、B组可评价的冠状动脉节段显示率分别是98.9%和99.1%,P〉0.05。平均心率〈70次/min的患者,绝大多数最佳重建时相在50%-80%R-R间期范围内;平均心率≥70次/min的患者,绝大多数最佳重建时相在30%-80%R-R间期范围内。结论与64层螺旋CT相比,时间分辨力的提高使双源CT能够在相当宽的心率范围内提供优良的图像质量,有很高的临床应用价值。

Objective To compare the image quality and visibility of coronary arteries by dual-source CT （DSCT） and 64-slice CT. Methods 100 patients （group A, 54 male, aged 57.9±11.3 years） with suspected coronary artery disease （CAD） were examined by DSCT. The other 100 patients （group B, 59 male, aged 58.0±11.1 years） with suspected CAD were studied by 64-slice spiral CT. Patients of group B with a heart rate above 70 bpm received oral β-blockers before the scan. Data were retrospectively reconstructed and reviewed by two observers. Image quality was assessed using a 3-point grading scale from excellent （1） to non-assessable （3） and the rate of displayed coronary segments was calculated. The optimal reconstruction phase was registered for each patient. Results The mean heart rates of group A was significantly higher than that of group B [（71±12） bpm vs （61±6） bpm; P〈0.05]. The mean scan time of group A was significantly shorter than that of group B [（7.95±1.01） s vs （11.85±0.89） s; P〈0.01]. In the evaluation of image quality, no significant difference was found between the two groups （1.31±0.53 vs 1.25±0.50; P〉0.05）. The rates of diagnostic coronary segments for two groups were 98.9% and 99.1%, respectively （P〉0.05）. For patients with heart rates 〈70 bpm, most optimal reconstruction phase ranged from 50% to 80%; For patients with heart rates ≥70 bpm, that ranged from 30% to 80%. Conclusion With high and heart rate independent temporal resolution, DSCT provides high diagnostic image quality in a wide range of heart rates as compared to 64-slice CT and is promising for clinical use.