Caroli disease: computed tomographic diagnosis.

Computed tomographic (CT) scan findings in patients with cavernous ectasia of the biliary tract (Caroli disease) have been described. Our patient had the isolated form of Caroli disease characterized by saccular dilatation of intrahepatic bile ducts and no evidence of portal hypertension. CT scan of the liver showed tiny dots with strong contrast enhancement within dilated intrahepatic bile ducts (the central dot sign). This finding when correlated with sonogram indicated portal radicles surrounded by dilated intrahepatic bile ducts.