肝脏上皮样血管平滑肌脂肪瘤的MRI征象分析

Epithelioid Angiomyolipoma of the Liver:Analysis of Magnetic Resonance Imaging Features

目的:分析肝脏上皮样血管平滑肌脂肪瘤(Epi-AML)的MRI特点。方法:回顾性分析经手术病理证实的10例(共11枚)肝脏Epi-HAML患者MRI资料,包括病灶的数目、部位、大小、外形、病灶实质部分T1、T2及扩散加权信号强度、是否含有脂肪成分、强化特征、病灶内血管、引流静脉情况、有无假包膜及周围肝实质有无肝硬化、脂肪肝背景。结果:9例患者为单发病变,1例为两枚病灶。7枚位于右叶,4枚位于左叶;10枚病灶呈圆形或椭圆形,境界清晰,T1WI低信号,T2WI高信号,9枚DWI高信号,3枚病灶内含有少量脂肪;动脉期11枚病灶均明显强化,强化模式9枚为"快进慢出"型;9枚病灶内可见点条状血管影,6枚病灶周边可见"早期引流静脉",3枚在门脉期和延迟期"假包膜"征;各有1例有肝硬化及脂肪肝背景。结论:少或无脂肪的境界清晰的富血供肿块、"快进慢出型"强化特征、病灶内血管影及早期引流静脉是肝脏,Epi-AML一定特征的MRI征象。

Purpose：To analyze MRI features of epithelioid angiomyolipoma（Epi-AML） of the liver.Methods：The MRI data of 11 pathologically proved Epi-HAML in 10 patients were retrospectively analyzed.The number of lesions,the location,size,shape,T1-weighted images（T1WI）,T2-weighted images（T2WI） and diffsuison-weighted images（DWI） signal intensity（SI）,presence of fatty component,enhancement pattern,vessels within lesion,draining veins,presence of pseudocapsule and presence of steatosis or cirrhosis were recorded and analyzed.Results：There was one lesion in 9 patients,two lesions in other 1 patient.Seven lesions were located in the right lobe,other 4 lesions in the left lobe.Ten lesions were round or oval with clear boundary and shown with hypointensity on T1 WI,hyperintensity on T2 WI.Nine lesions were displayed as hyperintensity on DWI.Only 3 lesions showed with the presence of fat;11 lesions were manifested as obvious enhancement on the arterial phase,9 lesions were with ＂wash in and slow out＂ enhancement pattern.Punctate or filiform vessels were displayed in 9 lesions.＂Early venous drainage＂ was observed in 6 lesions.Pseudocapsule was shown on the portal venous and delayed phases in 3 lesions.Cirrhosis and fatty liver were discovered in 1 patient,respectively.Conclusion：The hypervascular mass with clear boundary,presence of fatty component or not,with ＂wash in and slow out＂ enhancement pattern and opacification of punctiform or filiform vessels within lesion,presence of ＂early venous drainage＂,are common MR features of hepatic Epi-AML.