64排冠状动脉CT成像延时时间的优化

目的探讨MSCT冠状动脉成像的扫描延时时间和对比剂注射的优化方案。方法将100例冠心病患者均分为两组。A组；预测冠状动脉成像延时时间一测试扫描中对比剂在升主动脉根部显像时间＋对比剂团注时间一扫描时间；B组：冠状动脉扫描延时时间一对比剂到达升主动脉根部的达峰时间＋4s。对两组数据均选择75％时相重建冠状动脉图像，分别测量降主动脉在不同心动周期及不同层面的CT值；根据降主动脉的时间一密度曲线（TDC）变化趋势，评价冠状动脉造影数据采集时相的准确性。结果A组34例冠状动脉成像采集时相与对比剂达峰时间相匹配，10例TDC呈持续上升型，6例呈持续下降型；B组10例冠状动脉成像采集时相与对比剂达峰时间相匹配，38例TDC呈持续上升型，2例呈持续下降型，A组扫描获得最佳时相明显多于B组（P〈0．01）。结论利用A组条件进行64排冠状动脉CT成像较易获得最佳扫描时相。

Delay time optimization of 64-row CT coronary angiography

Objective To investigate the optimized MSCT coronary imaging scan delay time and contrast agent injection program of 64-row CT coronary.Methods Totally 100 patients with coronary heart disease were enrolled and equally divided into 2 groups.Group A: Delay time of coronary imaging was the sum of the time of contrast agent imaging in the aorta and the time of contrast injection minus scanning time during the test scan.Group B: Delay time of coronary imaging was assessed as the aortic peak time plus 4 s.The data were reconstructed using 75% phase of coronary images,and then CT value of descending aorta were measured in different levels of cardiac cycles.According to the descending trends of time-density curve(TDC) of aorta,the accuracy of coronary angiography of different data collection phases was evaluated.Results In Group A,there were 34 patients whose’ coronary artery imaging acquisition phase matching the peak time,while TDC of 10 patients present as rising type,of 6 cases as failing type.In Group B,there were 10 cases whose’ coronary artery imaging acquisition phase matching the peak time,while TDC of 38 patients present as rising type,of 2 cases as failing type.Group A was more likely to get best scanning phase than group B(P<0.01).Conclusion Under conditions of Group A,it is more likely to get best scanning phase during 64-row CT coronary.