目的比较不同剂量前瞻性门控 轴面扫描心脏冠状动脉多层螺旋CT成像质 量及辐射剂量。方法 抽取通过前瞻性门 控轴面扫描拟行心脏冠状动脉成像的80 例患者为研究对象，随机双盲法将其分 为两组，每组40例，120kV/100mAs者为 低剂量组，120kV/200mAs者为常规剂量 组，多层螺旋CT扫描后专业人员处理图 像，比较两组图像质量及有效辐射剂量 等指标。结果 低剂量组图像质量：优30 例，良10例；常规剂量组图像质量：优31 例，良9例，两组图像质量比较差异无统 计学意义(P＞0.05)；两组SNR、CNR比较 差异无统计学意义(P＞0.05)；低剂量组 ED(1.71±0.18)mSv显著低于常规剂量组 的(2.86±0.44)mSv，差异有统计学意义 (P＜0.01)。结论 低剂量前瞻性门控轴面 扫描成像与常规剂量成像质量类似，但能 显著减少受检者辐射剂量，值得临床推 广。

Objective To compare the quality and radiation dose of multi-slice spiral CT imaging of different dose of prospective gated axial scan for cardiac coronary artery. Methods 80 patients receiving cardiac coronary artery imaging by prospective gated axial scan were selected as the research object and were divided into two groups by the randomized double blind method with 40 cases in each group. Patients with 120kV/100mAs were included in the low dose group while with 120kV/200mAs were included in the conventional dose group. After multi-slice spiral CT scanning, the images were processed by professionals and the image quality and effective radiation dose and other indexes were compared between the two groups. Results The image quality in the low dose group: 30 cases were excellent and 10 cases were good, image quality in the conventional dose group: 31 cases were excellent and 9 cases were good and the differences between the two groups were of no statistical significance (P>0.05), The differences in SNR and CNR between the two groups were of no statistical significance (P>0.05); ED (1.71±0.18) mSv in the low dose group was significantly lower than (2.86±0.44) mSv in the conventional dose group and the difference was statistically significant (P<0.01). Conclusion The imaging quality of low dose prospective gated imaging is similar to the conventional one, but it can significantly reduce the radiation dose to the patients, which is worthy of clinical promotion