The plain abdominal radiograph in acute pancreatitis.

The radiographs of 100 patients with acute pancreatitis were reviewed and compared with 100 controls by two radiologists and a surgeon. Our aim was to assess the frequency and usefulness of the signs described in the literature. Calcification of the pancreas was seen in one case only. Abnormalities of the biliary tree (visible gallbaldder, biliary gas and gallstones) were seen in 10%. The left psoas shadow was more frequently absent in the pancreatitis series. Paucity of gastrointestinal gas although observed in 12 cases was ascribed to vomiting. A more important sign was the gaseous outline of an adynamic duodenal loop which was seen in half of the patients examined in the left lateral decubitus position. Dilated jejunum was seen in 31 cases, associated with sentinel loops in 10 and multiple fluid levels in 25 patients. Dilatation of thet ransverse colon was the most constant colonic sign (18%), but the colon 'cut-off' sign was not seen. It was concluded that the most prominent signs in order of importance are a gaseous distension of the duodenal loop, gas in the duodenal cap, a dilated transverse colon and the sentinel loop. The gasless abdomen is a striking but rare sign and in our series was always associated with severe pancreatitis.