目的探讨128层双源CT3种扫描 模式下冠状动脉CT血管造影(CTA)的显像 价值差异。方法 选取行冠状动脉CTA检查 的123例患者为研究对象,采用随机数字表 法将其分成A、B、C三组，每组各41例。 A组采用回顾性心电门控低螺距螺旋(LS) 模式扫描，B组采用前瞻性心电触发序列 (S)模式扫描，C组采用的高螺距螺旋(FS) 模式扫描。比对三组患者不同扫描模式下 图像质量、扫描时间、辐射剂量长度乘积 (DLP)及有效剂量(ED)差异。结果 ①根据 15段分法，此次入组的123例患者共评价 1736个冠状动脉节段，三组患者图像质量 主观评分及图像质量优良率对比均无统计 学意义(P＞0.05)；②三组患者中A组扫描 时间、DLP及ED均显著高于其他两组，其 次为B组，C组则最低，组间对比差异具有 统计学意义(P＜0.05)。结论 128层双源 CT的LS、S、FS等三种扫描模式均具有理 想的显像价值，图像质量良好；其中FS模 式较S及LS模式辐射剂量较低，可作为实 现低辐射剂量冠状动脉CTA检查的有效手 段应用于临床诊疗工作中，以提升患者预 后水平。

Objective To investigate the difference in coronary CT angiography (CTA) imaging value under 128 slice dual source CT 3 scan mode. Methods 123 patients who underwent CTA examination were taken as the research objects. According to the random number table method, the patients were divided into A, B, C of three groups with 41 cases in each group. Group A was canned with a retrospectively ECG-gating low pitch spiral (LS) mode. Group B was scanned with a prospective ECG triggering sequence (S) mode and group C was scanned with a high pitch spiral (FS) mode. The image quality, scanning time, radiation dose length product (DLP) and effective dose (ED) under different modes were compared among the three groups. Results ①According to 15 segment division method, the enrolled 123 patients were evaluated with 1736 coronary artery segments. The differences in subjective score and good and excellent rate of image quality among the three groups were not statistically significant (P>0.05); ②Among the three groups, the scanning time, DLP and ED of group A were significantly higher than those of the other two groups, followed by group B and group C was the lowest. The differences between groups were statistically significant (P<0.05). Conclusion The LS,S and FS of three kinds of scanning modes of 128 slice dual source CT are of ideal imaging value and the image quality is good; The radiation dose of FS mode is lower than that of S and LS mode. It can be used as an effective means of low radiation dose coronary CTA in the clinical diagnosis and treatment to improve the prognosis level of patients.