肝动脉-门静脉瘘的多层螺旋CT诊断

Hepatic arterioportal shunt:MSCT diagnosis

目的探讨肝动脉-门静脉分流(APS)的多层螺旋CT(MSCT)动态增强表现、诊断能力、形成机制及临床意义。方法1 100例患者进行了肝脏MSCT动态增强检查,发现80例APS,其中,肝细胞癌(HCC)71例,转移性肿瘤2例,单纯性肝硬化6例,1例无明显肝实质异常。71例HCC均经DSA检查,以DSA诊断APS为标准,对照分析MSCT诊断APS的能力及APS的CT特征。结果71例HCC在MSCT增强动脉期均发现与APS相关的阳性征象。MSCT增强表现分为:中央型(52例)和周围型(19例)。中央型表现为:①肝动脉期门静脉主干和/或左右第1级分支提早显影;②肝动脉期低密度门静脉瘤栓内及其周围有网状动脉显影(滋养动脉);③肝动脉期可见门静脉管壁强化与低密度门静脉瘤栓形成“门静脉铸型”。周围型表现为:①肝动脉期肿瘤所在肝叶的非癌变肝实质、肿瘤外周和肝叶边缘出现楔形或片状强化区,门静脉期该区域密度与其他部位正常肝组织密度一致;②肝动脉期门静脉分支呈线条状显影且与肝动脉伴行,即“轨道征”;③肝动脉期肿瘤内门静脉提早显影。结论MSCT诊断APS的准确性可与DSA相比。MSCT血管成像可望替代DSA。APS的MSCT诊断对指导肝癌的治疗具有重要意义。

Objective To evaluate the dynamic enhanced multi-slice spiral CT （MSCT） features and the formative mechanisms of APS （arterioportal shunt）, and to assess its CT diagnostic ability and clinical value. Methods 1 100 patients received dynamic enhanced MSCT scan of the liver and 80 cases with APS were found. Of the 80 cases with APS, 71 were hepatocellular carcinoma （HCC）, 2 with metastatic tumor, 6 with hepatocirrhosis, 1 without definite hepatic disease. All the 71 patients with HCC received DSA of the liver. MSCT signs and its diagnostic ability for APS were analyzed and compared with the golden standard of DSA, Results All the 71 patients with HCC had positive CT findings related to APS in arterial phase. The MSCT signs of APS were divided into two types： the central type and the peripheral type. In the 52 cases of central type： ①in the arterial phase, the main portal vein （PV） and the left/right branches of PV were revealed earier;②the network artery in and around embolus of PV were revealed; ③the ＂PV casting＂ was formed with the enhanced PV walls against the low attenuation embolus. While in the 19 cases of peripheral type： ①in the arterial phase, wedge and patchy high attenuation appeared in the non-tumor parenchyme of the hepatic lobes, the tumorous rim and the margin of the hepatic lobes, while in the PV phase, this attenuation became the same as that of the normal liver;②the PV branches enhanced in shape of lines, accompanied with hepatic arteries （so-called the ＂rail sign＂） ;③earlier revelation of PV inside the tumor. Conclusion The dynamic enhanced MSCT can be used as an important tool for the diagnosis of hepatic APS, and its accuracy could be comparable to that of DSA. It is possible that MSCT angiography （MSCTA） may replace DSA. MSCT diagnosis of APS is of great clinical significance in the treatment of HCC.