冠脉钙化积分扫描对前瞻性门控冠脉成像扫描长度的界值确定研究

摘要

Objective:To investigate the clinical value of adjusting the scan length of CT coronary angiography with prospectively gated axial CT technique using the calcium scoring images instead of the scout view with regard to radiation dose. Methods:70 patients suspected or proved coronary atherosclerotic cardiopathy were randomly divided into two groups. The scan range of CT coronary angiography of group A (33 patients) was planned on the axial images of the calcium scoring by identifying from lcm below the origin of the left main artery to lcm below cardiac apex. The scan range of CT coronary angiography of group B (37 patients) was planned on the scout view by identifying from lcm below the carina to just lcm below the diaphragm. The scan length,radiation dose.dose length product,effective radiation of A and B group were compared. Radiation doses were calculated for CT coronary angiography in two groups. Results: The scan length of Group A was significantly lower than that of Group B [(12. 19±1. 78)cm vs (13. 62±2. 14)cm,P = 0. 004]. The radiation dose of A group and B group had no siginificant differences [(20. 83±9. 75)mGy vs (22. 28±7. 48)mGy,P = 0. 484]. The dose length product of Group A was significantly lower than that of Group B [(253. 57±116. 84)mGy-cm vs (306. 69±121. 59)mGy cm, P=0. 067<0. 10]. The effective radiation dose of Group A was significantly lower than that of Group B [(4. 31± 1. 99) mSv vs (5. 22±2. 07)mSv,P = 0. 065<0. 10]. Conclusion: Adjustment of the scan length using the images from calcium scoring instead of the scout view is feasible and is associated with a 17. 5% reduction in radiation dose of CT coronary angiography with prospectively gated axial CT technique.%目的:本研究通过采用钙化积分影像控制前门控扫描长度并与采用定位片方式进行辐射量对比,评价其临床应用价值.方法.70例拟诊或确诊冠状动脉粥样硬化性心脏病的患者随机分为A、B两组,A组33例,采用冠脉钙化积分扫描数据进行CTCA扫描范围界定,拟扫描范围为左冠状动脉主干出现层面以上1 cm至心尖部层面以下1 cm；B组37例,采用定位片进行CTCA扫描范围界定,拟扫描范围为气管隆突下1 cm至膈下1 cm.比较A、B两组的扫描长度、CT剂量指数、剂量长度乘积与有效剂量,检验水准α=0,10.结果:A、B组平均扫描长度分别为(12.19±1.78)和(13.62±2.14) cm,A组低于B组,差异有统计学意义(P=0.004)；A、B组平均CT剂量指数分别为(20.83±9.75)和(22.28±7.48) mGy,差异无统计学意义(P=0.484)；A、B组平均剂量长度乘积分别为(253.57±116.84)和(306.69±121.59) mGy·cm,A组低于B组,差异有统计学意义(P=0.067＜0.10);A、B组平均有效剂量分别为(4.31±1.99)和(5.22±2.07) mSv,A组低于B组,差异有统计学意义(P=0.065＜0.10).结论:通过钙化积分影像可以更加精确的控制扫描长度,在扫描范围完全覆盖心脏的情况下与定位片控制扫描长度相比降低了辐射剂量.