The gastric air-fluid sign: aid in CT assessment of gastric wall thickening.

The differentiation of apparent gastric wall thickening due to incomplete gastric distention from true pathologic wall thickening can be difficult on computed tomographic (CT) scanning. We have observed a transition in gastric wall thickening that is often present at or slightly above the gastric air-fluid or air-contrast level. The apparently thickened gastric wall in the dependent portion of the stomach undergoes an abrupt change to normal thickness at or above the air-fluid level. Review of CT scans in 259 patients without known or suspected gastric pathologic conditions revealed this finding, termed the "gastric air-fluid sign," in 57 patients (22%). While not considered diagnostic, the presence of this sign may allow for a greater degree of confidence in the CT assessment of gastric wall thickening in an appropriate clinical setting.