MRI在肝移植术后缺血性胆管病变中的应用

Application of MRI on ischemic-type biliary lesions after liver transplantation

目的探讨MRI、磁共振胰胆管造影(MRCP)在肝移植术后缺血性胆管病变(ITBL)中的应用价值。方法经PTC或ERCP及病理结果确诊的肝移植术后ITBL患者23例,对其平扫、增强MR和MRCP图像进行观察。结果根据胆管病变累及的部位和范围,将ITBL分为肝门型(Ⅰ型)、弥漫型(Ⅱ型)和肝内型(Ⅲ型)。Ⅰ型13例,MRI示12例胆管壁增厚,11例供体肝总管及胆总管不扩张,且伴有供肝肝总管、汇合部及左和(或)右肝管管腔内胆泥形成;MRCP主要表现为胆总管、肝总管、汇合部、左右肝管及其二级分支胆管显影不良或不显影。Ⅱ型8例,MRI示7例管壁增厚,6例供体肝总管及胆总管不扩张,且伴有供肝肝总管、汇合部及左和(或)右肝管管腔内胆泥形成;MRCP主要表现为肝内、外胆管广泛的不规则狭窄或扩张,胆管间断显影。Ⅲ型2例,MRI示供体肝总管及胆总管管腔均不扩张,管壁未见增厚;MRCP主要表现为肝内胆管不规则、节段性扩张,扩张不成比例、粗细不均呈"串珠"样。结论肝移植术后ITBL以Ⅰ型和Ⅱ型常见。MRI在观察肝门部胆管管壁,管腔扩张程度及腔内容物有一定优势,而MRCP可全面观察胆管病变的部位和范围,提供整体信息;二者结合有助于ITBL的诊断及分型。

Objective To observe the application value of MRI and magnetic resonance cholangiopancreatography（MRCP） on ischemic-type biliary lesions（ITBL） after orthotopic liver transplantation.Methods Twenty-three patients with ITBL after liver transplantation diagnosed on bases of PTC or ERCP and pathology were selected.Conventional MR,contrast-enhancement MR and MRCP images of liver graft were observed.Results ITBL was classified into three types on the base of the location and range of bile duct lesion： Porta hepatis type（type Ⅰ）,extensive type（type Ⅱ） and intrahepatic type（type Ⅲ）.Thirteen ITBL were typeⅠ.MRI showed thickening bile duct wall in 12 patients.The pipe diameter of donor common hepatic duct and common bile duct was not dilated and sludge formation in the lumen of donor common hepatic duct,confluence and left and/or right hepatic duct was found in 11 patients.Absent or thin bile signal at the level of common bile duct,common hepatic duct,confluence and left or right hepatic duct and second level bile duct were mainly observed on MRCP.Eight ITBL were type Ⅱ.MRI showed thickening bile duct wall in 7 patients,the pipe diameter of donor common hepatic duct and common bile duct without dilation and sludge formation in the lumen of donor common hepatic duct,confluence and left or right hepatic duct in 6 patients.Segmental bile signal,irregular stenosis and dilation at the level of intrahepatic and extrahepatic bile ducts were observed on MRCP.Two ITBL were type Ⅲ.The pipe diameter of donor common hepatic duct and common bile duct was not dilated,no thickening bile duct wall was observed on MRI.MRCP showed irregular,segmental and string-of-beads stenosis and dilation at the level of intrahepatic small bile ducts.Conclusion ITBL of type Ⅰ and Ⅱ were common.MRI has advantage in observing bile duct wall,dilation degree of the bile ducts diameter and the content in the lumen.However,MRCP can generally show the location and range of bile duct lesion.Combination of them contributes to the diagnosis and typing of ITBL.