Department of Radiology, University Hospital of Erlangen, Erlangen, Germany.
JACC Cardiovasc Imaging. 2011 Jun;4(6):602-9. doi: 10.1016/j.jcmg.2011.02.014.
The aim of this study was to evaluate the mean heart rate and heart rate variability (HRV) required for diagnostic imaging of the coronary arteries simultaneously with thoracic computed tomography for noncardiac purposes, applying a high-pitch spiral image acquisition protocol for computed tomography angiography (CTA) using a dual-source system.
For the primary prevention of coronary heart disease, screening methods to identify currently asymptomatic people who are at high risk for developing coronary heart disease are essential. Coronary CTA can rule out coronary artery stenoses with high negative predictive value.
High-pitch thoracic computed tomography was performed in 111 consecutive patients (mean age 60.2 ± 11.5 years; range 37 to 81 years) using a dual-source system (2 × 128 0.6-mm sections, 38.4-mm collimation width, 0.28-s rotation time). Data acquisition was prospectively electrocardiographically triggered at 60% of the R-R interval using a pitch of 3.2. Image quality was evaluated using a 3-point scale (1=excellent, 2=moderate, 3=poor).
Close interobserver agreement for image quality scores of 1,998 evaluated coronary segments was found (κ=0.93). Image quality was of diagnostic value in 828 of 1,739 segments (47.6%). In 29 of 111 patients (26%), diagnostic image quality was observed for all segments. Average heart rate and HRV were significantly (p<0.001) higher in patients with at least 1 nondiagnostic coronary segment compared with those without. All patients with mean heart rates <64 beats/min and HRV <13 beats/min had diagnostic image quality in all coronary segments. Effective radiation dose for thoracic CTA was 1.9 ± 0.66 mSv. The mean scan time was 0.9 ± 0.1 s.
Simultaneous evaluation of coronary arteries in high-pitch dual-source CTA of the thorax for noncardiac purposes is consistently diagnostic in patients with low heart rates and HRV, whereas most patients not receiving beta-blockers had at least 1 segment that was not diagnostic because of heart rate and HRV. Beta blockers are recommended if there are no contraindications and coronary interpretation is anticipated.
本研究旨在评估同时进行非心脏目的的胸部计算机断层扫描（CT）和冠状动脉诊断成像所需的平均心率和心率变异性（HRV），应用双源系统的高螺旋图像采集协议进行 CT 血管造影（CTA）。
对于冠心病的一级预防，识别目前无症状但患有冠心病风险较高的人群的筛查方法至关重要。冠状动脉 CTA 具有高阴性预测值，可排除冠状动脉狭窄。
使用双源系统（2×128 0.6-mm 层厚，38.4-mm 准直宽度，0.28 秒旋转时间）对 111 例连续患者（平均年龄 60.2±11.5 岁；年龄范围 37 至 81 岁）进行高螺旋胸部 CT 检查。数据采集使用 3.2 的螺距，在心电图触发下前瞻性地在 R-R 间期的 60%处采集。使用 3 分制评估图像质量（1=优秀，2=中等，3=差）。
对 1739 个评估冠状动脉节段的图像质量评分进行了密切的观察者间一致性评估（κ=0.93）。828 个节段（47.6%）的图像质量具有诊断价值。在 111 例患者中有 29 例（26%）观察到所有节段的诊断性图像质量。与无诊断节段的患者相比，至少有 1 个非诊断节段的患者的平均心率和 HRV 显著（p<0.001）更高。所有平均心率<64 次/分钟和 HRV<13 次/分钟的患者在所有冠状动脉节段均具有诊断性图像质量。胸部 CTA 的有效辐射剂量为 1.9±0.66mSv。平均扫描时间为 0.9±0.1 秒。
在非心脏目的的高螺旋双源胸部 CTA 中同时评估冠状动脉，在心率和 HRV 较低的患者中始终具有诊断价值，而大多数未服用β受体阻滞剂的患者由于心率和 HRV 而至少有 1 个节段不具有诊断价值。如果没有禁忌症并且预计会进行冠状动脉解读，则建议使用β受体阻滞剂。
