Value of computed tomography in detecting occult gastrointestinal perforation.

Five patients with clinically unsuspected gastrointestinal perforation were evaluated preoperatively with computed tomography (CT). In each case the CT demonstration of pneumoperitoneum established the diagnosis of a ruptured viscus and prompted early surgical intervention. The site of perforation was apparent on CT in four of the five patients. Plain radiographs including upright chest films (two patients) and supine radiographs of the abdomen (one patient) were interpreted as negative for free air prior to CT. The CT features of pneumoperitoneum and its clinical implications are reviewed.