多层面螺旋CT肝脏双期增强技术的研究——造影剂量及团注造影剂跟踪技术的影响

Dual-phase multi-slice helical CT of the liver:effect of contrast material volume and bolus tracking

目的:评价造影剂量及团注造影剂跟踪技术对多层面螺旋CT肝脏双期增强效果的影响。材料与方法:40名观察对象随机分为三组,分别从周围静脉注入Omnipaque300100ml、100ml和75ml。第一组以固定时间间隔扫描,第二组及第三组以团注造影剂跟踪技术启动扫描。以腹主动脉增强值超过150Hu为动脉期开始,肝实质增强值大于20Hu为动脉期结束。结果:①第一组中5例(45%)动脉期扫描序列未处于其最佳扫描间期,第二组为2例(13%),第三组为1例(8%);②第一组中2例(18%)肝实质强化峰值未包括在其门静脉期扫描序列中,2例(18%)强化峰值位于扫描序列的末期,而第二组和第三组的强化峰值均位于其扫描序列的中心层面;③各组间主动脉及肝实质增强值的差异无统计学意义。结论:①团注造影剂跟踪技术能更准确确定动脉期的起点;②75ml的造影剂量能够满足多层面螺旋CT肝脏双期增强的要求。

Objective:To assess the effects of contrast material volume and bolus tracking in dual phase multi slice helical CT of the liver.Materials and Methods:Fourty patients were randomly divided into three groups with different volumes of Omnipaque300:100ml,100ml and 75ml.In group one,the scanning delays were fixed,whereas in group two and three,scanning delays were determined individually by means of a semiautomatic bolus tracking device.The optimal scanning intervals(OSI) of arterial phase for MSCT were defined as the interval when the enhancement value for the aorta reached 150Hu and ending when the value for the liver parenchyma reached 20Hu.Results:1In group one,the arterial scanning sequences of five cases were not within their OSI,but in group two and three there were only two cases and one case;2During the portal venous phase,the liver parenchyma peak enhancement of two cases was not within the portal venous scanning sequences(PVSS) and that of two cases were near the ending of their PVSS in group one,whereas in group two and three,the peak enhancement of liver parenchyma was all near the center of their PVSS.3No significant difference of the peak enhancement of aorta and liver parenchyma were observed among these three groups.Conclusion:1A semiautomatic bolus tracking device can determine the OSI more precisely in dual phase MSCT of the liver;2For MSCT contrast medium volume can be decreased to 75ml effectively.