The obstractive end appeared blant or flat, or abruptly interrupted etc.In benign lesions the biliary ducts appeared as withered tree,and the obstructive end showed cupping or filling defuts.

• 阻塞端呈圆钝状、平直、突然截断等，良性病变的胆管扩张程度较轻，胆管分支如枯枝状或残根状，阻塞端表现为杯口状或充盈缺损(结石)或粗细不均。