[The diagnosis of annular pancreas (author's transl)]

Annular pancreas is a rare congenital malformation of the gut; frequently it becomes manifest in adult life. The clinical picture and radiological appearances are dominated by stenosis of the duodenum. The only method for diagnosing annular pancreas up to the present was the barium meal. Its diagnostic accuracy, however, is limited. A knowledge of the characteristic radiological appearances is helpful unless other abnormalities confuse the interpretation. E.R.C.P. is an important advance in diagnosis. The diagnosis of annular pancreas can be made by demonstrating an accessory duct system. The literature is reviewed.