多层螺旋CT双通路注射法行肝门静脉系统成像的研究

The investigation of bi-pass way injection method to show hepatic portal system by multi-detector computed tomography

目的：确定多层螺旋CT肝门静脉系统检查的合理延迟时间及双通路注射对比剂法的可行性。方法：分为2个步骤研究：①随机选择无腹部及心血管疾忠的患者53例，以3ml／s速率注射造影剂20ml，行同层动态扫描，计算腹主动脉、肝门静脉、下腔静脉、肝实质的对比剂时间密度曲线，及它们的相关性。②47例需门静脉检查的患者，行MDCT肝区移床式、动态扫描，在右肘部静脉及下肢静脉同时注入对比剂，对比剂总量1．5～2ml／kg。扫描时使用对比剂自动示踪软件，设动脉血管阈值为120HU启动扫描，动脉期扫描完成后延时20．1±5．54s行门静脉扫描，分别评价肝门静脉、肝静脉、下腔静脉的显示率及程度。结果：①20ml对比剂注射同层动态扫描肝门层面腹主动脉达峰时间为18．5±4．81s，肝门静脉达峰时间是38．61±6．59s，下腔静脉达峰时间是55．44±12．16s，肝实质的达峰时间是56±5．7s。②肝门静脉显示率达100％，肝门静脉主干等显示程度平均评分2．50～2．93；相关小分支静脉显示率为87％～98％，显示平均评分2．25～2．63。结论：MDCT右肘部静脉及下肢静脉同时注入对比剂，在动脉期扫描完成后，延时20．1±5．54s行肝门静脉检查，肝门静脉系统成像效果良好。

Objective：To determine reasonable delay time and feasibility of bi-pass way to inject contrast agent in hepatic portal system imaging. Methods： Two steps to study： ① 53cases without abdominal and cardiovascular disease were selected randomly. dynamic scan was performed after injected C. M. 20ml in rate of 3ml/s. Draw the time-density-curve. ② Forty-seven patients were performed dynamic scan after injected contrast agent to right elbow vein and lower extremity vein at the same time. Total dosage： 1.5～2ml/kg. Using contrast automatic tracing software,Setting the threshold of aterial vessel at 120Hu. hepatic portal system phase scan was performed after arterial phase scan 20. 1±5.54 seconds. Results： ① In control group, the peak time of abdominal aorta was 18. 5±4.81 s, hepatic portal vein was 38.61±6.59 s, inferior vena was 55.44±12. 16 s, liver parenchyma was 56±5.7 s. ②100% hepatic portal vein was displayed, the score of hepatic portal wein displaying was 2.50± 2.93, the displaying rate of small broche was 87±98%. The score was 2.25±2. 63. Conclusion： Inject contrast medium to right elbow vein and lower extremity vein at the same time using MDCT, hepatic portal vein scan time was 20. 1_＋5.54 s delay after arterial phase. The image quality of hepatic portal vein system is satisfactory