摘要
目的 探讨低剂量64层螺旋CT测定冠状动脉钙化积分的准确性.方法 2006年8月至2009年9月间对43名冠状动脉钙化的患者连续进行2次64层螺旋CT扫描,管电流时间积分别为常规剂量（100 mAs）和低剂量（55 mAs）,其余参数不变,由2名放射科副主任医师测定钙化积分并测量升主动脉CT值的均数及标准差.结果 低剂量与常规剂量钙化总积分和独立血管钙化积分取平方根转换后均直线相关（r=0.998、0.997）.低剂量管电流时间积所测升主动脉根部的CT值的均数与2倍标准差之和小于130 HU,可满足所要求的信噪比,与常规剂量扫描辐射剂量（1.32±0.08）mSv相比较,低剂量扫描有效剂量降低0.6 mSv（P＜0.05）.结论 低剂量前瞻性心电门控64层MDCT钙化积分扫描图像能满足测量需要,测量结果具有较高的准确性.
Objective To compare the low- and standard-dose protocols in the evaluation of coronary artery calcification （CAC） scores and in image quality,and to assess the accuracy of low-dose prospective ECG-gated helical CT in CAC measurements.Methods Forty-three patients with CAC were scanned twice using a tube current setting of 100 and 55 mA retrospectively.CAC scores （Agatston） of different branches of coronary artery were recorded.The mean and SD of the CT attenuation values in regions of interest in the aorta were measured,and the value （mean ＋ 2 × SD） were obtained.Results Calcification plaques were found in 105 of the 172 vessels in the 43 subjects.The radiation dose of the 50 mAs group was （0.72 ± 0.04） mSy,significantly lower by 0.6 mSv than that of the 100 mAs group [（1.32 ± 0.08） mSv,P ＜ 0.05].The total calcification score of the 55 mAs group was significantly positively correlated with the routine dose group after performing the square root transformation （r =0.998）.A signficant correlation existed in vessel-based calcification between these 2 groups （r= 0.997）.Conclusions Low-dose prospective ECG-gated 64-slice CT yields high accuracy on CAC scoring while maintaining the image quality needed to measure CAC.
出处
《中华放射医学与防护杂志》
CAS
CSCD
北大核心
2010年第5期605-609,共5页
Chinese Journal of Radiological Medicine and Protection
基金
吴阶平医学基金会临床科研专项资助基金（32067501003）
