目的 探讨双源CT低剂量冠状 动脉成像在诊断冠心病中的应用价值。 方法 将我院收治的90例行双源CT(dual source computed tomography，DSCT)检 查冠心病患者纳入研究，以数字表法将 其随机分为低剂量组与常规剂量组，各 45例，比较2组扫描过程中剂量参数[CT 容积剂量指数(Volume CT dose index， CTDIvol)、剂量长度乘积(dose-length produet，DLP)、有效剂量(effective Dose，ED)]、螺距、图像质量、图像噪 声。结果 2组患者扫描过程顺利，低剂 量组CTDIvol、DLP及ED均明显低于常 规剂量组(P＜0.05)；2组ROI面积、螺 距、可评价节段、图像优良率、图像质 量评分比较无统计学意义(P＞0.05)； 低剂量组图像噪声明显高于常规剂量组 (P＜0.05)。结论 患者心率基本不会对 回顾性心电门控扫描模式产生影响，失 败率低，适当减小球管电压与电流值亦 能达到图像质量要求，并且降低辐射剂 量，DSCT低剂量冠状动脉成像对冠心病 诊断具有重要应用价值。

Objective To explore the value of dual source CT low-dose coronary angiography in the diagnosis of coronary heart disease (CHD). Methods 90 patients with CHD who underwent dual source computed tomography (DSCT) examination were enrolled in the study, and they were randomly divided into low dose group and routine dose group, with 45 cases in each group. The dose parameters [volume CT dose index (CTDIvol), dose length product (DLP), effective dose (ED)], pitch, image quality and image noise were compared between the two groups. Results The scanning process of the 2 groups was smooth, and the CTDIvol, DLP and ED in the low dose group were significantly lower than those in the routine dose group (P<0.05). There was no significant difference between the 2 groups in the ROI area, pitch, evaluable segment, the excellent and good rate of image and image quality (P>0.05). The image noise of low dose group was significantly higher than that of the routine dose group (P<0.05). Conclusion The heart rate has no effect on the retrospective ECG gated scan mode, and the failure rate is low. Reducing the bulb tube voltage and current value also can reach the requirement of image quality, and reduce the radiation dose. DSCT low dose angiography is of great value in the diagnosis of CHD.