肝移植术后移植肝非肿瘤性实质病变的MRI诊断

目的探讨MR在肝移植术后非肿瘤性肝实质病变诊断中的应用价值及其对临床治疗的指导意义。方法 22例原位肝移植受体及1例活体右半肝移植受体在术后MR随访中发现移植肝非肿瘤性肝实质病变,其中经再次手术病理或穿刺活检证实为：中重度急性排斥反应9例,炎性病变4例（肝脓肿3例,嗜酸性肉芽肿1例）;肝实质缺血或梗死3例;肝实质淤血2例;脂肪肝2例。长期随访证实为动静脉分流6例。分析上述非肿瘤性肝实质病变的MR表现及MR在病因学诊断中的潜在价值。结果 MRI正确诊断所有肝脏炎症病变、肝实质缺血或梗死、肝实质淤血、脂肪肝,无漏诊及误诊病例;但1例嗜酸性肉芽肿根据MR检查仅能诊断肝实质炎性病变,未能直接得到嗜酸性肉芽肿诊断。首次MR检查正确诊断5/6例肝内周围型动静脉分流,1例在随访中证实。急性排斥反应患者肝脏MR检查无异常信号出现（7/9例）或仅表现为T2WI肝实质均匀或斑片状稍高信号（2/9例）,所有病例均未在MR检查中得到诊断。LAVA序列MRA成像准确发现所有肝实质缺血或梗死患者的肝动脉狭窄（3例）和门静脉狭窄（1例）,及肝淤血患者的肝中静脉狭窄（1例）或闭塞（1例）,并在DSA检查中得到证实。3例肝脓肿患者中,2例在MR胰胆管成像中证实合并缺血性胆道狭窄、MRA发现肝动脉狭窄。结论 MRI在移植肝非肿瘤性肝实质病变的定位、定性及病因诊断中发挥重要作用;但无助于急性排斥反应的无创性诊断。

MR imaging for graft non-neoplastic lesions after liver transplantation

Objective：To discuss the role of MR examination for graft non-neoplastic lesions after liver transplantation and the clinical value of MR results.Materials and Methods：From Jan 2005 to Dec 2009,23 receptors received MR examination during the follow-up period and were detected graft non-neoplastic lesions.Post-operative histopathology or biopsy confirmed moderate/severe acute rejection in 9 cases,inflammatory lesions in 4 cases（3 with liver abscess,1 with eosinophilic granuloma）,liver ischemia or infarction in 3 cases;liver congestion in 2 cases;fatty liver in 2 cases.Long-term follow-up confirmed hepatic arteriovenous shunt in 6 cases.Among them,22 received orthotopic liver transplantation and the other one received right lobe living donor liver transplantation.We discussed the MR performances of above non-neoplastic lesions and its role for the etiological diagnosis.Results：Based on MR examination,all the inflammatory lesions,liver ischemia,infarction,congestion and fatty liver were correctly diagnosed without missed diagnosis and misdiagnosis of cases.But in 1 case,according to MR performances,liver lesions only were judged as inflammatory,eosinophilic granuloma was not diagnosed.Intrahepatic peripheral arteriovenous shunt was correctly diagnosed in 5/6 cases based on the first MR examination,and 1 case was confirmed in the follow-up period.In the patients with acute rejection,MR signal was normal in 7/9 cases and abnormal in 2/9 cases only with homogeneous or patchy slightly higher signal in T2WI.All cases were not diagnosed in MR examinations.Based on LAVA data,MR angiography（MRA） presented all the vascular complications confirmed by DSA for the patients with graft ischemia,infarction or congestion,including 3 hepatic artery stenosis,1 portal venous stenosis,1 middle hepatic vein stenosis and 1 middle hepatic vein occlusion.In the 3 cases with liver abscess,2 were detected ischemic biliary stricture in MR Cholangiopancreatography and hepatic artery stenosis in MRA.Conclusion：MR examination played an important role in deciding the location,property and etiology for graft non-neoplastic lesions after liver transplantation.However,it could not help for the non-invasive diagnosis of acute rejection.