混合型肝脏血管平滑肌脂肪瘤的CT和MRI诊断

CT and MRI Diagnosis of Hepatic Angiomyolipoma

目的探讨肝脏血管平滑肌脂肪瘤(hepatic angiomyolipoma,HAML)CT和MRI的诊断价值。资料与方法回顾性分析经病理证实的8例肝脏HAML的CT和MRI表现。8例均行CT平扫和多时相动态增强扫描,其中4例同时行MRI平扫和多时相动态增强扫描。结果 8例均为单发混合型HAML,CT平扫均表现为低于周围正常肝组织的混杂低密度,灶内含有不同程度的脂肪密度,CT值-40～40HU。4例MRI平扫表现为稍长T1(含短T1)、稍长T2混杂信号,T1WI上高信号在使用脂肪抑制技术后完全消失。CT与MRI多时相动态增强扫描显示动脉期病灶均呈显著不均匀强化,门静脉期6例CT、3例MRI病灶呈持续或渐进性中重度强化,高于周围正常肝实质,2例CT、1例MRI病灶轻中度强化;3例HAML见假包膜,且在门静脉期及延迟期有轻度强化。结论 CT和MRI能显示混合型HAML的特征性表现并可在术前做出准确诊断。

Objective To investigate the CT and MRI features of hepatic angiomyolipoma （HAML）. Materials and Methods The CT and MRI features of 8 cases with HAML confirmed pathologically were analyzed retrospectively. CT plain scan and multiphase （arterial and portal） enhanced scan were performed in 8 cases,4 cases of them also underwent plain MRI scan and dynamic enhanced scan simultaneously. Results 8 cases showed the lesion mixed with various fat and heterogeneous low-density area which ranged in CT value from -40 to 40 HU on plain CT scan. 4 cases underwent plain MRI scan exhibited low signal intensity and heterogeneously high signal intensity,which were disappeared completely after using fat saturation on T1WI. Multiphase dynamic enhanced scanning was performed in all cases shows the lesions were strong enhanced during arterial phase. 6 cases on contrast-enhanced CT scan and 3 cases on contrast-enhanced MRI scan showed moderate enhancement,while others cases showed slight enhancement during portal venous and delayed phase. Pseudocapsule detected in 3 cases showed slight enhancement on portal venous and delayed phase. Conclusion CT and MRI can reveal the characteristic findings of mixed type HAML and accurate preoperative diagnosis can be made.