Biliary infections: spectrum of imaging findings and management.

Infectious cholangitides encompass a wide spectrum of infectious processes affecting the biliary tree. They can have protean clinical and imaging appearances. Some manifest as an acute medical emergency with high mortality if not properly and emergently managed. Others are chronic processes that may predispose a patient to liver failure or cholangiocarcinoma. The clinical and imaging features and the subsequent therapy are dictated by the pathogens involved, the immune status of the host, and the degree and distribution of biliary obstruction. Bacteria cause most cases of infectious cholangitis in Western countries. In other parts of the world, parasites play an important role, either as causative agents or in predisposing the host to bacterial superinfection. Viral cholangitides primarily affect immunocompromised patients. The clinical and imaging features of cholangitis differ between immunocompetent and immunocompromised patients. Imaging plays a pivotal role in diagnosis of infectious cholangitis, helps identify predisposing causes, and demonstrates complications. Moreover, interventional radiology provides tools to treat acute life-threatening biliary infections, chronic entities, and complications.