CT scan in the management of acute appendicitis

BACKGROUND: Recent studies demonstrate a 98% accuracy of a CT scan in the diagnosis of acute appendicitis. We aimed to determine the accuracy and clinical value of CT scans in patients suspected of having acute appendicitis. PATIENTS AND MATERIALS: We reviewed outcomes of 125 patients over a 5-month period who had CT scans for the initial diagnosis of acute appendicitis. CT scan interpretations were correlated with surgical and pathologic findings. Follow-up was attempted in all patients who did not undergo appendectomy. RESULTS: CT scans and clinical courses were complete in 110 patients (88%); 14 patients were lost to follow-up and 1 was excluded. One patient had two CT scans. Thus, there were 111 CT scans available for review. Radiologic interpretation of these CT scans yielded 36 positive (33%), 67 negative (60%), and 8 indeterminate (7%), resulting in a sensitivity of 90%, a specificity of 89%, a PPV of 78%, and a NPV of 96%. CONCLUSIONS: CT scan may be useful in the diagnosis of acute appendicitis, but the reported high accuracy rate was not reproduced at our institution. CT scan was not clinically useful in 21% of patients. We conclude that a CT scan may be beneficial in the diagnosis of appendicitis with selected patients who have equivocal findings. Thus, at our institution, the accuracy of a CT scan does not justify its routine use in patients with clinical findings of appendicitis.