256层CT冠状动脉成像延迟触发时间优化的初步研究

Preliminary Study of the Trigger Delay Time Optimization of 256-row CT Coronary Artery Imaging

目的探讨256层CT冠状动脉成像延迟触发时间优化的可行性。资料与方法对2010-07～09行冠状动脉CT成像的127例患者的临床资料及扫描参数进行分析,采用多重线性回归分析法分析患者的年龄、性别、身高、体重、心率及延迟扫描次数与延迟触发时间的相关性。结果 127例患者中,延迟触发时间12～26s,平均(19.0±2.9)s。正式触发前延迟扫描次数为6～20次,平均(13.3±2.7)次。多重线性回归分析法显示,延迟触发时间与延迟扫描次数呈正相关(r=0.40283,P<0.001),与心率呈负相关(r=-0.52002,P<0.001),与身高呈正相关(r=0.36998,P<0.001)。结论 256层CT冠状动脉成像延迟触发时间有一定范围,且与延迟扫描次数及患者的身高、心率存在相关性,通过增加注射后延迟时间,可减少延迟触发时间内机器的延迟扫描次数,从而降低患者所受辐射剂量。

Purpose To investigate the feasibility of optimizing trigger delay time of 256-row CT coronary artery imaging.Materials and Methods The clinical data and scan parameters of 127 patients undergoing coronary CT imaging in our hospital from July to September 2010 were analyzed using multiple linear regression. The relationship of the trigger delay time with age, sex, height, weight, heart rate and delayed scans were evaluated. Results In all 127 patients, the range of trigger delay time was 12-26 seconds and the average was （19.0±2.9） seconds. The frequency of delay scan before the official trigger was 6-20 times and the average was （13.3±2.7） times. Multiple linear regression analysis showed that factors related to the trigger delay time were delayed scans, height and heart rate. Trigger delay time and delayed scans was positively correlated （r = 0.402 83, P 0.001）. There was negative correlation with heart rate （r =-0.520 02, P 0.001） and positive correlation with height （r = 0.369 98, P 0.001）.Conclusion The trigger delay time of 256-row CT coronary artery imaging is related to delayed scans, patients＇ height and heart rate. By increasing the delay time after injection, we can reduce the times of delayed scans during the trigger delay, thereby reduce the radiation dose.