[Radiologic diagnostics of the gall bladder and bile ducts-part 1 : Imaging techniques-normal variants and congenital disorders-cholelithiasis].

Upper abdominal pain, icterus and cholestasis are the main symptoms leading to evaluation of the biliary tract. Since the advent of contrast-enhanced ultrasound techniques the accuracy of bile duct imaging has significantly improved. This is also true for computed tomography using isotropic secondary reconstructions as well as magnetic resonance imaging (MRI) including MR cholangiography (MRC), classically and after iv injection of hepatobiliary contrast agent. Diffusion-weighted imaging sequences have a recently proven ability for improving biliary tract imaging. These technical improvements provide the depiction of the non-dilated biliary tract system in diagnostic quality. Therefore, normal variants and congenital disorders of biliary tract anatomy are delineated as well as insights into the postoperative situs and complications related to surgery. Cholelithiasis is the most frequent disease of the gall bladder and biliary tract. Together with related complications, in the majority of cases it is also the reason for bile duct inflammation. Due to the immediate need for treatment special care has to be taken for hydrops of the gall bladder.