Unconventional cholangiography

Conventional imaging of the biliary tract includes fluoroscopic cholangiography, oral contrast computed tomography (CT) cholangiography, and magnetic resonance cholangiopancreatography. The latter two are discussed in the prior article of noninvasive cholangiography. Fluoroscopic cholangiography can be divided into endoscopic retrograde cholangiopancreatography and percutaneous transhepatic cholangiography (see pages 74-89, this issue). This article discussed a varying group of imaging techniques that can be added as modifiers to some of the above imaging modalities to obtain different, if not clearer, images of the biliary tract in particular clinical scenarios. These techniques, which are collectively called by the author, "unconventional cholangiography," include (1) distal occlusive cholangiography, (2) digital subtraction cholangiography, and (3) transhepatic CT cholangiography. These techniques are well described in other medical disciplines or in other parts of the body by radiologists. The current author implements these concepts to the biliary tract. In the author's opinion, they offer additional delineation and characterization of biliary disease in particular clinical, anatomical, and pathological situations that are described in the article.