自身免疫性肝炎核磁共振成像的临床价值

Magnetic resonance imaging in the diagnosis of autoimmune hepatitis

目的:探讨自身免疫性肝炎(AIH)患者的核磁共振成像(MRI)的影像学表现,以提高其诊断准确性。方法:回顾性分析2011年10月~2016年11月中山大学附属第三医院收治,并经临床、生化、免疫学及病理证实的31例AIH患者影像资料。所有研究对象均行MRI检查,总结相关MRI影像学图像特点。结果:(1)肝脏形态学改变及信号异常:25例全肝肿大,且肝实质T_2加权像(T_2WI)序列信号增高,扩散加权序列(DWI)增高或不高;4例肝脏形态正常,T_2WI序列信号正常;2例肝脏体积缩小,并肝表面多发结节形成,T_2WI信号不均匀降低。(2)继发性改变:31例脾均增大,4例门静脉主干增粗、胃底及脾静脉延长迂曲,13例腹腔少量积液形成,14例肝内门脉周围间隙增宽,21例胆囊窝少量积液及胆囊壁增厚。(3)其他:10例肝内胆管轻度扩张,所有患者均无淋巴结肿大改变。结论:AIH的MRI影像学特点包括肝、脾肿大;肝实质T_2WI及DWI信号增高及胆囊窝积液多见,可伴有肝内胆管扩张;而肝脏萎缩及肝硬化结节形成等晚期肝硬化征象少见;较少伴有淋巴结肿大;癌变罕见。MRI或可作为AIH影像学一项有效的检查手段。

Objective To analyze the magnetic resonance imaging（MRI） features of patients with autoimmune hepatitis（AIH）and to improve the diagnostic accuracy of MRI for AIH. Methods From October 2011 to November 2016, admitted to the Third Affiliated Hospital, Sun Yat-sen University, 31 patients with clinically, biochemically, immunologically and pathologicallyconfirmed AIH were selected. The MRI imaging data of 31 selected patients were retrospectively analyzed, and the MRI features related to AIH were reviewed and analyzed. Results Hepatomegaly was detected in 25 patients showing hyperintensity on T2-weighted imaging（T2WI） and slight hyperintensity or constant signal intensity on diffuse weighted imaging（DWI）; 4 patients had normal liver morphology with normal T2WI signal, and 2 patients had hepatatrophia with multiple nodules on the liver surface and heterogeneous hypointensity on T2WI. The secondary changes included splenomegaly（31 cases）, main portal vein enlargement with esophageal and gastric fundus varices（4 cases）, ascites（13 cases）, enlarged preportal space（14 cases）, and gallbladder wall thickening and gallbladder fossa fluid（21 cases）. Intrahepatic biliary dilatation was detected in 10 patients, and none of the 31 patients had retroperitoneal lymphadenopathy. Conclusion The MRI features of AIH patients include hepatomegaly and splenomegaly, commonly with hyperintensity on T2WI and DWI of liver parenchyma, gallbladder fossa fluid, maybe accompanied with intrahepatic biliary dilatation. Few of AIH patients show signs of advanced cirrhosis, such as hepatatrophia, surface nodularities with cirrhosis. Lymphadenopathy is uncommon, and cancer is rare in AIH patients. MRI may be a valuable tool for the diagnosis of AIH.