肝内肝动脉-门静脉分流的CT表现及其诊断意义

Intrahepatic Arterioportal Shunts: CT Appearance and Their Diagnostic Significance

目的 分析 18例肝内肝动脉 门静脉分流 (APS)的螺旋CT动态增强表现 ,研究其与DSA表现的相关性 ,并探讨APS的形成原因及诊断意义。资料与方法 18例APS中 ,13例为肝细胞癌 (HCC) ,2例单纯肝硬化 ,1例HCC术后肝内多发转移 ,1例肝脓肿穿刺治疗后 ,1例肝脏无明确病变。 18例APS均行螺旋CT动态增强三期扫描 ,其中 7例还进行了DSA检查。结果 18例APS中 ,17例的CT增强动脉期表现分三型 :(1)门静脉三级 (亚段 )及以上分支提早显影 (Ⅰ型 ) 11例 ;(2 )肿瘤 /病变周围肝实质提早强化 (Ⅱ型 ) 6例 ;(3)肝脏边缘结节形、楔形提早强化区 ,且其邻近无占位性病变 (Ⅲ型 ) 3例。另有 1例CT未发现确切APS征象。 7例APS在DSA动脉期表现为 :门静脉三级及以上分支提早显影 (Ⅰ型 ) 1例 ;门静脉三级以下分支提早显影 ,且迂曲、增粗 (Ⅱa型 ) 6例 ;呈“双轨征”表现 (Ⅱb型 ) 4例 ,其中包括CT上无APS表现的 1例。结论 APS的病因中 ,HCC是最主要的 ,其他原因还有肝硬化、医源性肝损伤以及不明原因者。跨血管、跨肝窦、跨肝血管丛的途径是肝癌、肝硬化APS形成的主要机制。APS的CT和DSA表现并无显著相关性。

Objective To analyze the dynamic enhanced spiral CT findings of intrahepatic arterioportal shunts (APS), to correlate the findings with DSA signs, to study the cause of APS formation and to evaluate the clinical significance of APS.Materials and Methods Eighteen cases of APS were collected in this study. The hepatic lesions included HCC (n=13), cirrhosis (n=2), postoperative multiple intrahepatic metastases due to HCC (n=1), hepatic abscess after puncture treatment (n=1) and no definite hepatic disease (n=1). Spiral CT dynamic enhanced scanning was performed in all 18 patients, additional DSA was done in 7 of them.Results Of 18 cases with APS, 17 could be divided into three enhancement types according to their CT signs in arterial phase. (1) Type Ⅰ, early visualization of the sub segmental or more proximal portal branches (n=11). (2) Type Ⅱ, early enhancement of the tumor or the hepatic parenchyma round the lesion (n=6). (3) Type Ⅲ, early enhancement of peripheral nodules or wedge shaped areas without any space occupying lesion nearby (n=3). The remaining one case showed no definite APS signs. On DSA, the 7 cases showed following signs. (1) Early visualization of the sub segmental or more proximal portal branches (type Ⅰ, n=1). (2) Early enhancement of the portal branches distal to the sub segmental ones, which were dilated and tortuous (type Ⅱa, n=6). (3) 'Double track' sign was seen in 4 cases, including the case showing no APS signs on CT scans (type Ⅱb). Conclusion HCC is the main cause for the development of APS, the other causes include cirrhosis, iatrogenic injury and some unknown factors. Trans sinusoidal, trans vascular and trans vascular plexal growing route is the key mechanism of APS formation in HCC and cirrhosis. No obvious correlation between CT findings and DSA signs exists in APS.