[Diagnosis of gastroenterologic diseases with sonography. Part 2: Gallbladder and bile ducts].

The anatomical position of the gallbladder makes it readily accessible to ultrasonographic visualization. Gallstones, gravel and sludge present no diagnostic problems. Acute cholecystitis, empyema and perforation may be more difficult to detect. In the presence of large or numerous stones in the gallbladder, there is a danger of overlooking a carcinoma of the gallbladder. Bile duct carcinomas are difficult to detect by ultrasonography. While bile duct dilatation and the site of an occlusion are readily detected, the cause of the occlusion is usually not revealed by ultrasonography.