肝脏螺旋CT多期扫描中造影剂的应用

目的:研究肝脏螺旋CT多期扫描中造影剂的不同注射速度对正常肝脏强化的影响,选择最佳的多期扫描延迟时间.方法:正常肝脏60例随机分为3组,先进行全肝平扫,然后以不同速度(2,3及4s)从肘静脉注入60%泛影葡胺100ml后15s,选择第一肝门层面开始扫描,以后每隔5s在同一层面扫描一次,共扫描3min.分别测量各组腹主动脉、门静脉和肝实质增强前、后不同时间的CT值,其中腹主动脉选取中心部位测量,门静脉选取门静脉主干中心部位测量,肝实质则选三个点(左叶一点,右叶前、后段各一点),然后取平均值.观察3组增强效果并进行统计学比较.结果:各组主动脉、门静脉和肝实质增强效果以3ml/s与4ml/s组为优,4ml/s组略高于3ml/s组,统计学处理两者间无显著性差异(P＞0.05),而与2ml/s组比较均有显著性差异(P＜0.01).2ml/s组主动脉、门静脉及肝实质到达峰值的时间分别为45,70,70,120s开始进入平衡期;3ml/s和4ml/s组均为21,62,62,120s开始进入平衡期.结论:在造影剂总量相同时,适合肝脏螺旋CT多期扫描的造影剂注射速度是3ml/s;最佳的肝脏螺旋CT多期扫描延迟时间为动脉期20s,门静脉期60s,平衡期180s.

THE APPLICATION OF CONTRAST ENHANCEMENT IN MULTIPLE-PHASE HEPATIC HELICAL CT

To study the optimal contrast material injectio n rate and scan delay time in the multiplephase hepatic helical CT scan by means o f evaluation of alterations in contrast material injection rate on aorta, p ortal vein and liver enhancementMethods:The liver of sixty pat ients was examined with helical CT before and after injection of contrast mate rial The patients were randomized into three groups and each group of patient s were given the same amount of contrast material at different injection r ate ( 2ml/s,3ml/s,4ml/s respectively) Scans were performed at the level of first l iver hilus and started at 15s after injection of contrast material, then rep eated every 5s for 3min CT value of aorta, portal vein and three ROIs (regio ns of interest) in the liver were respectively quantitated on before and after c ontrastenhancement scan and statistical analysisResults: Aortic, portal venous and hepatic enhancement were different with altering injec tion rates in the same volume of contrast material (100ml) The group of 4ml/s shows greater enhancem ent effect but no significant difference statistically with the group of 3ml/s; both of the groups of 4ml/s and 3ml/s show significant difference comparing wit h the group of 2ml/s It was also found that the mean time reach to peak aorta, portal vein and liver enhancement was different with variable rates It was 4 5s,70s,70s respectively for 2ml/s; 21s, 62s, 62s for 3ml/s and for 4ml/s respe ctivelyConclusion:The injection rate by 3ml/s were suitable for multiplephase hepatic scans, and the optimal delay time for arterial phase ; portal venous phase and delay phase scans should be 20s, 60s and 180sec respec tively