前门控在256层螺旋CT冠脉成像中应用的探讨

目的通过分析冠脉CTA图像质量及辐射量探讨前门控对冠心病的临床应用价值。方法选取行冠脉CTA检查患者500例，心率≤70次／min者124例；心率〉70次／min者376例，前者随机分为前后门控两组，后者均为后门控扫描。结果心率≤70次／min者，前后门控两组图像质量评分分别为4．14±0．87和4．15±0．83，差异无统计学意义（P〉O．05）；有效辐射量分别为（1．89±0．57）mSv和（15．01±4．13）mSv，差异有统计学意义（P〈0．05）。心率〉70次／min者：71～85次／min者优质图像所在R—R间期百分比具有不确定性；心率〉85次／rain者100％在40％～50％R—R间期。结论心率≤70次／min时，前后门控冠脉成像图像质量具有一致性，前门控明显降低了辐射量；心率〉70次／min者也可以应用前门控技术扫描。

Applications of snapshot pulse in the cardiac computed tomography coronary angiography with 256-slice computed tomography

Objective To explore the clinical application value of snapshot pulse by analyzing the image quality and radia tion dose of computed tomography coronary angiography. Methods We selected 500 patients with coronary CTA examina tion, including 124 cases with heart rate of 70 times/min or less and 376 cases with heart rate 〉 70 times/rain. The for mer were randomly divided into two groupssnapshot pulse and retrospective ECG gating,and the latter were all retrospec tive ECG gating. Results For the heart rate of 70 times/min or less, image quality scores in snapshot pulse and retrospec tive ECG gating groups were 4. 14I0. 87 and 4. 15±0.83 respectively. There were no significant differences in image quality between the two groups （ P 〈0.05）. The effective radiation doses were （1.89±0.57） mSv and （15.01±4.13） mSv in the two groups （ P 〈0.05）. For the heart rate form 71 to 85, the RR interphase percentage of high quality image was uncertain. However, for the heart rate 〉85 times/rain, it＇s 40%-50%totally. Conclusion For the heart rate of 70 times/rain or less, the image quality of snapshot pulse and retrospective ECG gating groups are consistent, but snapshot pulse reduces the radiation significantly. Snapshot pulse is also applicable to the heart rate 〉 70 times/min.