Efficacy of abdominal computed tomography in evaluation of possible abdominal abscess

A retrospective analysis was made of all abdominal computed tomography scans performed because of clinical suspicion of an abscess at our institution over a 12-month period. Of 130 patients examined, 45 patients had had abdominal surgery within the previous 2-week period. Of these patients, 14 were found to have abscesses on computed tomography, with three known false-negative studies. An additional nine patients had sterile postoperative collections. Nine patients had had an abdominal abscess previously diagnosed, and five of these had a residual abscess. A total of seven abscesses were found by computed tomography in 76 patients who had had no surgery in the previous 2 weeks, with one known false-negative study. High-risk categories of nonoperative patients were identified. Only one positive study occurred in a patient without a high clinical index of suspicion for an intraabdominal abscess, although a total of 50 patients fell into this low-risk, nonoperative category. The cost-effectiveness of computed tomography studies in such low-risk patients is questioned.