肝外胆道梗阻的CT和MRI分析

目的探讨肝外胆道梗阻的多层螺旋CT和磁共振影像特征。方法选择经手术和病理证实的65例肝外胆道梗阻性病变患者,其中肝外胆道结石21例,慢性胰头炎2例,恶性胆道梗阻42例。使用多层螺旋CT多期增强扫描47例。使用1.5T超导MRI扫描仪检查18例,SE序列常规T1WI和T2WI横断和冠状面成像,MRCP使用单次激发厚层投射技术。结果47例中MSCT显示轻度胆总管及肝内胆管扩张3例,中度12例,重度32例,对肝外胆管梗阻程度的判断和定位准确率为97.9%,定性诊断准确率为87.2%。18例MRCP胆胰管显示满意,对肝外胆管梗阻程度的判断和定位准确率为100%,结合常规MRI图像定性诊断准确率为88.9%。结论MSCT与MRI检查可以对肝外胆道梗阻作出早期诊断,特别以MRCP能清楚显示扩张胆管的部位、形态及与周围组织结构的关系,优于CT。

Evaluation of extrahepatic biliary obstruction by CT and MRI

Objective To discuss the major features of extrahepatic biliary obstruction by MSCT and MRI. Methods 65 cases with extrahepatic biliary obstruction were retrospectively studied including bile duct stone(n=21), chronic pancreatitis(n=2) and malignant biliary obstruction(n=42). All cases were confirmed by surgery and pathology. 47 cases underwent enhanced multiphase MSCT scanning and 18 cases examined by 1.5T MRI with T1WI and T2WI and breath-hold MRCP in heavily T2WI fast spin-echo sequence. Results MSCT showed intrahepatic and extrahepatic bile duct dilation in mild degree(3 cases), moderate degree (12 cases), ang severe degree (32 cases). The accuracy of the degree, position and the nature of extrahepatic bile duct obstruction were 97.9% and 87.2% by MSCT respectively. In all 18 patients undertaken MRI, the pancreatico-biliary duct was satisfactorily shown by MRCP. The accuracy of the degree, position and the cause of extrahepatic bile duct obstruction were 100% and 88.9% respectively. Conclusion MSCT and MRI is helpful for the early diagnosis of extrahepatic bile duct obstruction. MRCP may also define the cause of extrahepatic biliary duct obstruction.