目的 探讨双低剂量技术在急 性主动脉综合症(AAS)患者CT血管成像 (CTA)中的应用情况。方法 选取2014年 5月-2017年5月医院行主动脉CTA检查的 AAS患者130例作为研究对象，根据扫描 方案分为A组(电压80-100kV，碘海醇 300mgI/ml)71例和B组(电压120kV，碘海 醇370mgI/ml)59例，两组其他扫描参数 相同。记录两组患者CTA图像噪声值、对 比噪声比(CNR)、图像质量主观评分、各 主动脉平均CT值、有效辐射剂量(ED)和 对比剂碘摄入量。结果 两组患者CTA图 像噪声值、CNR、图像质量主观评分及主 动脉根部、髂总动脉、升主动脉、降主 动脉、腹主动脉平均CT值比较，差异无 统计学意义(P＞0.05)；A组ED、对比剂 碘摄入量明显低于B组，差异有统计学意 义(P＜0.05)。结论 主动脉CTA扫描中应 用双低剂量技术，不仅可获得满意的图 像质量和目标血管CT值，还可减少辐射 剂量及对比剂碘摄入量。

Objective To investigate the application of double-low dose in CT angiography (CTA) of patients with acute aortic syndrome (AAS). Methods A total of 130 patients with AAS undergoing CTA in the hospital from May 2014 to May 2017 were selected as the subjects. According to the scanning program, they were divided into group A (treated with voltage 80-100kV and iohexol 300mgI/ml, 71 cases) and group B (treated with voltage 120kV and iohexol 370mgI/ml, 59 cases), and the other scanning parameters were the same in the two groups. The CTA image noise value, contrast noise ratio (CNR), subjective score of image quality, average CT value of each aorta, effective radiation dose (ED) and intake of contrast agent iodine in the two groups were recorded. Results There was no significant difference between the two groups in CTA image noise value, CNR, subjective score of image quality and the average CT values of aortic root, common iliac artery, ascending aorta, descending aorta and abdominal aorta (P>0.05). The ED and intake of contrast iodine in group A were significantly lower than those in group B (P<0.05). Conclusion The application of double-low dose technique in aortic CTA can not only obtain satisfactory image quality and CT value of target blood vessels, but also reduce the radiation dose and intake of contrast iodine.