肝移植术后肝实质缺血性损伤的多层CT诊断及病因学分析

目的探讨移植术后肝实质缺血性损伤的多层CT表现及CT诊断价值。方法多层CT检查发现43例肝动脉或门静脉狭窄或血栓,其中23例接受血管造影（DSA）检查,17例经病理组织学或随访复查诊断肝实质缺血或梗死。分析肝实质缺血或梗死的CT表现;并以DSA为对照分析CTA的病因学诊断价值。结果所有肝实质缺血或梗死区位于肝包膜下,平扫呈片状或楔形低密度灶,增强后缺血区强化减低,梗死区不强化,相应部位肝动脉或门静脉分支稀少、纤细或不强化。所有肝实质缺血或梗死患者CTA均发现不同程度血管病变,其中肝动脉病变占70.59%,门静脉病变5.88%,肝动脉合并门静脉病变23.53%,缺血性损伤分布与血管病变部位有关。以DSA为对照,CTA诊断肝动脉主干及门静脉狭窄和血栓的敏感性、特异性、阳性预测值及阴性预测值均为100%;诊断肝动脉分支病变上述值分别为100%、80.00%、72.73%、100%。结论多层CT动态增强结合CTA不仅能正确诊断移植肝缺血性损伤,还能准确评价导致移植肝缺血的血管病变,肝动脉病变为移植肝缺血性损伤的主要原因。

Ischemic damage of hepatic parenchema after liver transplantation: the value of multi-slice CT in diagnosis and etiologic analysis

Objective To discuss the CT features of graft ischemic damages after liver transplantation and estimate the value of multi-slice CT in the etiological analysis. Methods There were 43 patients who presented hepatic artery or portal vein stenosis or thrombosis in dynamic enhancement CT exams. Among them, 23 received hepatic arteriography and indirect portography; 17 had graft ischemia or infarction which was confirmed by histopathology or follow-up examinations. We retrospectively analyzed the CT features of hepatic ischemia and infarction after liver transplantation, and estimated the value of CT angiography (CTA) in etiological diagnosis. Results All the ischemia and infarction areas of the graft distributed in the subcapsular parts, which demonstrated patchy or wedge-shaped hypo-attenuation on plain CT scan, with lower or none enhancement on contrast-enhanced CT scan. The hepatic artery or portal vein branches in those areas were lessened, thinned or non-enhanced. CTA demonstrated hepatic artery or portal vein complications in all these cases, including hepatic artery complication (70.59%), portal vein complication (5.88%), and hepatic artery complication complicated with portal vein complication (23.53%). The distribution of ischemic damages related to the site of blood vessel lesions. Compared to DSA, the sensitivity, specificity, predictive value of positive cases (PVP) and predictive value of negative cases (PVN) of CTA in diagnosis of main trunk of hepatic artery and portal vein lesions (stenosis and thrombosis) were all 100%. The sensitivity, specificity, PVP and PVN of CTA in diagnosis of hepatic artery branches stenosis and thrombosis were 100%, 80.00%, 72.73% and 100%, respectively. Conclusion Combined CTA with dynamic enhancement CT examination not only could present the hepatic ischemic damages, but also could accurately demonstrate the state of blood vessel lesions which lead to hepatic ischemia or infarction. Hepatic artery complication is the main reason for hepatic ischemia.