64层CT冠状动脉成像的前瞻性与回顾性心电门控比较

目的 比较前瞻性心电门控和回顾性心电门控64层CT冠状动脉成像的辐射剂量和成像质量,探讨低剂量前瞻性心电门控CT冠状动脉成像的可行性.方法 两组心率≤65次/min各100例患者分别进行前瞻性和回顾性心电门控扫描,并采用多平面重组(MPR)、最大密度投影(MIP)、曲面重组(CPR)及容积再现(VR)多种重组技术显示冠状动脉,图像质量根据运动伪影影响分为优、良、差,使用剂量长度计算各自的有效辐射剂量,并进行统计学分析.结果 前瞻性组平均辐射剂量为(2.81±0.48)mSv明显低于回顾性组的(10.16±1.09)mSv(P＜0.01);前瞻性组诊断性冠状动脉节段和非诊断性冠状动脉节段为95.2%(1165/1224)和4.8%(59/1224),与回顾性组的94.1%(1186/1261)和5.9%(75/1261)比较,差异无统计学意义.结论 对于心率稳定在65次/min以下的患者,前瞻性心电门控64层CT冠状动脉成像,能以较低的辐射剂量达到回顾性心电门控诊断质量的影像,是切实町行的方法.

Diagnostic performance of prospective versus retrospective electrocardiogram-gated 64-slice computed tomography coronary angiography

Objective To compare the diagnostic performance of prospective electrocardiogram (ECG)-triggered computed tomography coronary angiography (CTCA) versus retrospective ECG-gated CTCA.Methods Patients with suspected coronary artery disease divided into two groups which underwent 64-slice CTCA with prospective ECG-triggered or retrospective ECG-gated scanning (n=100 each,HR≤65 bpm).Multi-planar reconstruction (MPR),curved-planar reconstruction (CPR),maximum intensity projection (MIP) and volume rendering (VR) were made to demonstrate the coronary arteries.The image quality was defined as excellent,good and poor by motion and stair-step artifacts.Individual radiation exposure dose was estimated from the dose-length product.Results The mean effective radiation dose of prospective ECG-triggered CTCA[(2.81±0.48)mSv] was significantly lower than that of retrospective ECG-gated CTCA[(10.16±1.09)mSv,P＜0.01].Segments of diagnostic image quality (95.2%,1165/1224) and non-diagnostic coronary segments (4.8%,59/1224) in prospective ECG-triggered group were similar as those of retrospective ECG-gated group (94.1%,1186/1261 and 5.9%,75/1261,all P＞0.05).Conclusion Though the radiation exposure dose required is significantly lower,the diagnostic performance of prospective ECG-triggered 64 slice CTCA is comparable with that of retrospective ECG-gated 64 slice CTCA on patients with stable heart rates up to 65 bpm.