肝脏血管平滑肌脂肪瘤MRI表现

Magnetic resonance imaging features of hepatic angiomyolipoma

目的:总结分析肝脏血管平滑肌脂肪瘤(AML)的MRI表现,比较上皮样与非上皮样肝脏AML的MRI表现差异。方法:搜集经手术病理证实的肝脏AML患者15例,11例行MRI检查,其中上皮样AML 5例,非上皮样AML 6例,1例非上皮样AML仅行MRI平扫,其余10例均行MRI平扫及动态增强扫描。结果:化学位移成像检出7例肿瘤的脂肪成分,而频率饱和法仅检出3例肿瘤的脂肪成像。无脂肪型中上皮样与非上皮样AML各2例;少脂肪型中上皮样AML 1例,非上皮样AML 3例;富脂肪型中上皮样AML 2例,非上皮样AML 1例;上皮样与非上皮样AML脂肪含量相仿。10例行增强扫描的病例中动脉期强化9例,门脉期强化6例,延迟期强化5例,延迟期环形包膜样强化9例,动态增强曲线8例呈动脉期速升,门脉期及延迟期强化迅速减低。结论:上皮样与非上皮样AML影像学表现差异较小,MRI检出脂肪含量多寡难以作为肿瘤是否为上皮样AML的诊断标准。在MRI动态增强扫描中,上皮样AML与富血管平滑肌的经典型AML强化形式相似。

Objective： In this study,we retrospectively analyzed the MRI manifestations of hepatic angiomyolipoma （AML） and compared the MRI manifestations of epithelioid and non-epithelioid AML. Methods.. 15 patients with surgery and pathology proven hepatic AML were recruited. Conventional MRI was performed in 11 patients, including epithelioid AML （5 cases） and non-epithelioid AML （6 cases）. Apart from one case of non-epithelioid AML underwent plain MRI scan only,the remaining 10 patients had plain MRI and dynamic contrast-enhanced scanning as well. Results：The fat components within the tumor were detected on chemical shift imaging in 7/11 cases,while on frequency saturation sequence in only 3/11 cases. Among the fat deficit type, there were epithelioid and non-epithelioid AML for 2 cases each. Among the low-fat type, there were epithelioid AML （1 case） and non-epithelioid AML （3 cases）. Among the fat-type there were epithelioid AML （2 cases）and of non-epithelioid AML （1 case）. The fat content was not significantly different between epithelioid and non- epithelioid AMLs. Of the 10 cases with contrast administration, enhancement presented at arterial phase （9 cases）, portal venous phase （6 cases） and delayed phase （5 cases） ,9 cases had capsule enhancement on delayed phase. Rapid ascending of enhancement curves showed in the arterial phase, while rapid descending showed in the portal venous phase and delayed phase （8 cases）. Conclusion：Few differences could be detected in the imaging manifestations of epithelioid and non-epitheli- old AML. The amount of fat content detected on MRI could hardly be the diagnostic standard of epithelioid hepatic AML. On dynamic contrast-enhancemed MRI,the pattern of epithelioid AML was similar to those of classic AML rich in blood vessels and smooth muscles.