Accuracy of specific free air distributions in predicting the localization of gastrointestinal perforations.

To evaluate the role of specific distributions of free air in predicting the location of gastrointestinal (GI) tract perforation. One hundred and fifteen patients with surgically proven GI tract perforation between January 2015 and June 2019 were included in the study. The site of perforation was based on surgical findings in all cases. Two radiologists retrospectively interpreted the computed tomography (CT) images of these patients for extraluminal free air distribution. Perforation sites were demonstrated intraoperatively in all cases and were categorized as follows: stomach and duodenum, jejunum and ileum, proximal colon (cecum, ascending colon, and transverse colon), distal colon (descending colon and sigmoid colon), rectum, and appendix. There were 79 male and 36 female patients with a mean age of 56.4 years. Periportal, perihepatic, and perigastric free air were statistically significant in predicting gastroduodenal perforation. Mesenteric free air was significant in predicting both small bowel and distal colon perforations. Pelvic free air was statistically significant in distal colon perforations. Periappendiceal free air was found to be a strong predictor of acute perforated appendicitis. Specific free air distributions may help to predict the site of gastrointestinal perforation, which would change the treatment plan.