Diagnosis of alimentary tract perforation by CT.

The roentgenologic diagnosis of digestive tract perforation is based primarily on evidence of free air shown on a standard abdominal film. However, this finding may not be present, especially during the first hours following trauma. This retrospective study of 10 patients shows that the anatomical precision of computed tomography can help greatly in detecting small collections of free air, in addition to other abdominal changes. Although CT is commonly requested for a cause of acute abdomen other than suspected perforation, the radiologist must also look carefully for a small collection of free air or other signs that may indicate free air.