目的 比较分析256层螺旋CT前、 后置心电门控技术冠脉成像质量及辐射剂 量。方法 以我院2013年1月-2015年12月 疑诊为冠状动脉疾病患者70例，随机双盲 法将其分为前门控组(36例)与后门控组 (34例)，所有患者检查前控制心率＜75次 /min，比较2组平均辐射时间、有效辐射 剂量及冠脉成像质量。结果 前门控组冠 脉成像质量优率59.2%，显著高于后门控 组的51.1%(P＜0.05)；但2组冠脉成像质 量优良率(90.3% vs 91.1%)比较差异无统 计学意义(P＞0.05)。前门控组平均辐射 时间、有效辐射剂量分别为(3.42±0.20) s、(3.15±1.00)mGy，均显著少于后门控 组的(5.22±0.38)s、(9.67±3.52)mGy， 差异有统计学意义(P＜0.001)。结论 256 层CT前、后置心电门控技术冠脉成像质量 均较高，且相比后门控技术，前门控技术 能显著减少辐射剂量。

Objective To compare and analyze the effects of 256 slice spiral CT prospective and retrospective ECG gating technique on coronary imaging quality and radiation dose. Methods 70 cases of patients who were diagnosed with suspected coronary artery diseases in our hospital between January 2013 and December 2015 were divided into prospective gating group (36 cases) and retrospective gating group (34 cases) by randomized double blind method. The control heart rates of all patients before examination were < 75 times /min. The average radiation time, effective radiation dose and coronary imaging quality were compared between the 2 groups. Results The excellent rate of coronary imaging quality in prospective gating group (59.2%) was significantly higher than that in the retrospective gating group (51.1%) (P<0.05) but there was no significant difference in good and excellent rate of coronary imaging quality between the 2 groups (90.3% vs 91.1%) (P>0.05). The average radiation time and effective radiation dose of the prospective gating group [(3.42±0.20)s, (3.15±1.00)mGy was significantly less than that of the retrospective gating group [(5.22±0.38)s, (9.67±3.52) mGy] (P<0.001). Conclusion The coronary imaging quality of 256 slice CT prospective and retrospective ECG gating technique is high and compared with retrospective gating technique, the prospective gating technique can significantly reduce the radiation dose.