RADIOLOGY: HEPATOBILIARY: Case# 71: PRIMARY SCLEROSING CHOLANGITIS. 26 year old female for pre-liver transplant evaluation. The liver is cirrhotic in configuration and diffusely heterogeneous in enhancement. There is mildly patchy enhancement involving all hepatic lobes and segments. There is patchy dilatation of the intrahepatic biliary ducts. The spleen is enlarged. Primary sclerosing cholangitis (PSC) may be associated with underlying conditions such as ulcerative colitis and retroperitoneal fibrosis but can be an isolated finding. PSC may progress to cirrhosis and protal hypertension. Characterisitc findings with PSC include nonuniform biliary dilatation with beaded areas of alternating stenosis and dilation. The nonuniformity and potentially focal nature of PSC distinguishes it from other causes of uniform biliary ductal dilatation. Secondary causes of sclerosing cholangitis include prior biliary surgery, choledocholithiasis, carcinoma, or infection.