磁共振弥散加权成像在原位肝移植术后缺血性胆管病变的应用价值

目的 探讨弥散加权成像(DWI)及表观弥散系数(ADC)值在原位肝移植术后缺血性胆管病变中的应用价值.方法 以PTC或ERCP检查,病理或临床定期随访资料为标准,筛选出中山大学附属第三医院2005年4月至2009年3月46例肝移植术后患者,将其分为缺血性胆管病变组(TTBL组,29例)和无缺血性胆管病变组(C组,17例),测量移植肝实质的ADC值(b值=600 s/mm2),并对DWI序列上移植肝胆道系统信号和MRCP上胆管树进行观察.结果 ITBL组和C组的移植肝ADC值分别为(1.456±0.286)×10-3mm2/s和(1.716±0.391)×10-3mm2/s,ITBL组ADC值低于C组,两组间差异有统计学意义(P=0.015).DWI上ITBL组和C组胆管壁信号增高发生率分别为82.8%(24/29)和5.9%(1/17),ITBL组DWI上胆道壁信号增高主要发生在肝门部胆管及肝内小胆管(70.8%,17/24).ITBL组与C组之间差异有统计学意义(P＜0.001).ITBL组21例伴发胆泥,DWI上呈高、等、低信号,C组中胆管管腔内未见异常信号.结论 DWI上ITBL主要表现为肝门部及肝内小胆管管壁信号明显增高,移植肝ADC值下降,可在一定程度上反映其病理学改变,可能对ITBL的早期诊断是一种有效的、敏感的监测指标.DWI作为一种新颖、无创、简单、实用的方法在肝移植术后ITBL的诊断、鉴别诊断具有重要的临床意义.

Abstract：

Objective To discuss the application values of DWI (diffusion-weighted imaging) and ADC (apparent diffusion coefficient ) on ischemic-type biliary lesions (ITBL) after orthotopic liver transplantation. Methods According to whether there was ITBL after liver transplantation or not, 46 cases of liver transplantation were selected and divided into 2 groups on the basis of PTC (percutaneous transhepatic cholangiography ) or ERCP (endoscopic retrograde cholangiopancreatography ) examination,pathology or clinical follow-up data: ITBL group ( n = 29 ) and no ITBL group ( C group, n = 17). The ADC value was measured for right lobe of graft liver parenchyma ( b value =600 s/mm2 ). And the signal of biliary system of graft on DWI and biliary tract on MRCP were analyzed. Results ( 1 ) The ADC values of liver graft were ( 1. 456 ± 0. 286 ) × 10 -3 mm2/s and ( 1. 716 ± 0. 391 ) × 10 -3 mm2/s in ITBL and C groups respectively. The difference in ADC value was significant between two groups ( P = 0. 015 ); ( 2 ) the incidence of increased signal of bile duct on DWI was 82. 8% ( 24/29 ) and 5.9% ( 1/17 ) for ITBL and C groups respectively. The lesion was located in porta hepatis and intrahepatic small bile duct was seen in 17 of 24 patients (70. 8% ) in ITBL group. The difference was significant in signal of bile ducts between ITBL and C groups ( P ＜ 0. 001 ). Twenty-one cases with sludge on DWI in ITBL group had hyperintensity, isointensity or hypointensity. There was no abnormal signal in the lumen of bile duct in C group. Conclusion The major sign of ITBL is a hyperintensity of porta hepatis and small bile ducts on DWI. And the ADC value of graft liver parenchyma decreases. These reflect the pathological changes to an extent and may be an effective and sensitive monitoring tool of early ITBL. DWI is a novel, non-invasive, simple and practical method in the diagnosis and differential diagnosis of ITBL after liver transplantation.

Application value of diffusion-weighted imaging in ischemic-type biliary lesions after liver transplantation

Objective To discuss the application values of DWI (diffusion-weighted imaging) and ADC (apparent diffusion coefficient ) on ischemic-type biliary lesions (ITBL) after orthotopic liver transplantation. Methods According to whether there was ITBL after liver transplantation or not, 46 cases of liver transplantation were selected and divided into 2 groups on the basis of PTC (percutaneous transhepatic cholangiography ) or ERCP (endoscopic retrograde cholangiopancreatography ) examination,pathology or clinical follow-up data: ITBL group ( n = 29 ) and no ITBL group ( C group, n = 17). The ADC value was measured for right lobe of graft liver parenchyma ( b value =600 s/mm2 ). And the signal of biliary system of graft on DWI and biliary tract on MRCP were analyzed. Results ( 1 ) The ADC values of liver graft were ( 1. 456 ± 0. 286 ) × 10 -3 mm2/s and ( 1. 716 ± 0. 391 ) × 10 -3 mm2/s in ITBL and C groups respectively. The difference in ADC value was significant between two groups ( P = 0. 015 ); ( 2 ) the incidence of increased signal of bile duct on DWI was 82. 8% ( 24/29 ) and 5.9% ( 1/17 ) for ITBL and C groups respectively. The lesion was located in porta hepatis and intrahepatic small bile duct was seen in 17 of 24 patients (70. 8% ) in ITBL group. The difference was significant in signal of bile ducts between ITBL and C groups ( P ＜ 0. 001 ). Twenty-one cases with sludge on DWI in ITBL group had hyperintensity, isointensity or hypointensity. There was no abnormal signal in the lumen of bile duct in C group. Conclusion The major sign of ITBL is a hyperintensity of porta hepatis and small bile ducts on DWI. And the ADC value of graft liver parenchyma decreases. These reflect the pathological changes to an extent and may be an effective and sensitive monitoring tool of early ITBL. DWI is a novel, non-invasive, simple and practical method in the diagnosis and differential diagnosis of ITBL after liver transplantation.