64排螺旋CT前置与后置心电门控 冠状动脉成像比较

目的比较前置心电门控（前门控）与后置心电门控（后门控）64排螺旋CT（64 MDCT）冠状动脉成像的图像质量及放射剂量,探讨前门控对冠心病的临床应用价值。方法48例患者随机分为两组,每组24例,平均心率分别为（61.67±7.29）次/分和（65.83±8.44）次/分,分别进行64 MDCT前、后门控冠状动脉扫描;采用t检验对两种扫描方式的冠状动脉图像质量及有效放射剂量进行统计分析。结果前门控与后门控两组冠状动脉图像质量评分均值分别为（3.54±0.66）分和（3.58±0.72）分,差异无统计学意义（P〉0.05）;前门控与后门控两组有效放射剂量均值分别为（2.40±0.12）mSv和（9.97±1.02）mSv,差异有统计学意义（P〈0.05）,前门控低于后门控76.00%。结论心率在一定范围内时（〈70次/分）,64 MDCT前门控冠状动脉成像的图像诊断质量与后门控具有一致性,且前门控可明显降低放射剂量。

Comparison of prospective and retrospective ECG gating coronary 64-row computed tomography angiography

Objective To compare image quality and radiation dose between prospective electrocardiograph (ECG)-triggered axial scan and retrospective ECG-gated helical scan in coronary 64-row CT angiography (CTA). Methods Forty-eight patients undergoing 64-row CTA were randomly divided into two groups. Twenty-four received prospective ECG-triggered axial scan, and the other 24 received retrospective ECG-gated scan. The mean heart rate of two groups were (61.67±7.29) bpm and (65.83±8.44) bpm. The imaging quality and the effective dose of two groups were analized with t-test. Results The imaging quality score for the two groups were 3.54±0.66 and 3.58±0.72 (P>0.05). Mean effective dose of prospective ECG-gated group and retrospective ECG-gated group were (2.40±0.12) mSv and (9.97±1.02) mSv (P<0.05). Mean effective dose of prospective group decreased by 76.00% compared to the retrospective group. Conclusion Prospective ECG-triggered axial scan in 64-row coronary CTA has the ability to significantly reduce radiation exposure dose. With certain heart raterange (<70 bpm), the imaging quality of the prospective scan has consistency with that of the retrospective scan.