肝动脉-门静脉分流多层螺旋CT分析

Evaluation of Hepatic Arterioportal Shunt with Multi-slice Helical CT Scanning

目的 探讨肝动脉 门静脉分流 (arterioportalshunt,APS)的多层螺旋CT(MSCT)增强特征及形成机制 ,评价MSCT在APS诊断中的作用和价值。资料与方法 回顾性分析 15 3例APS的CT影像特征及其基础疾病 ,所有病例均采用MSCT机扫描 ,对比剂注射流率 3ml/s ,剂量 90ml;动脉期延迟 2 5～ 2 8s,门脉期 5 0～ 5 5s ,实质期 3～ 5min。其中 75例完成了动脉期三维重建。结果 动脉期门静脉主干或分支提前显影 12 7例 ,其中 75例容积成像 (VR)清晰显示APS部位、形态及其与周围结构间的三维关系。动脉期肝实质呈楔形、三角形或不规则形片状强化 139例 ,其中单发 94例 ,2～ 3处 4 0例 ,弥漫性 5例 ;门脉期部分病灶密度仍较高 ,实质期病灶与肝实质密度一致。 90例原发肝癌及 16例转移瘤中 ,动脉期瘤灶部分实质明显强化 6 7例 ,门脉期多数病灶仍呈高密度 ,实质期呈低密度 ,其余39例瘤灶未见明显强化。上述APS按发生部位可分 4型 :即中央型 (6 0例 ) ,周围型 (32例 ) ,混合型 (5 6例 )和弥漫型 (5例 )。结论 多种疾病均可形成APS ,原发性肝癌是最主要原因。CT上APS可有多种特征性表现形式 。

Objective To discuss multi-slice CT (MSCT) features of hepatic arterioportal shunt (APS) and its mechanism, to evaluate MSCT in diagnosing APS. Materials and Methods CT features and the underlying diseases in 153 cases with APS were retrospectively analyzed. All the scanning was performed on a multi-slice helical CT unit. For enhanced scans, 90ml contrast material was intravenously injected with a rate of 3ml/sec. Delayed time was 25～28sec for arterial phase, 50～55sec for portal venous phase and 3～5min for parenchymal phase. Volume rendering reformation was completed in 75 cases.Results Early opacification of main portal vein and its branches during arterial phase was seen in 127 cases, of which the site, shape of APS was clearly displayed on volume rendering in 75. During arterial phase, triangular shape or irregular patchy enhancement was found in 139 cases, which was solitary (n=94), several (n=40) or diffuse (n=5). Of 90 HCC and 16 metastases, the lesion was markedly enhanced during arterial phase in 67. According to the location, APS could be divided into four types: central (n=60), peripheral (n=32), mixed (n=56) and diffuse (n=5) type. Conclusion Many diseases can induce APS, but HCC is the main cause. APS has many characteristic presentations on CT scans, which can be fully displayed on multiphase MSCT scanning and volume rendering.