The clinical role of noncontrast helical computed tomography in the diagnosis of acute appendicitis

Background: The accuracy of noncontrast helical computed tomography (CT) for appendicitis has recently been demonstrated. What is its clinical utility? Methods: This was a retrospective review of 443 consecutive community hospital patients evaluated for acute appendicitis over an 18-month period using limited pelvic CT scan or clinical acumen alone. Results: Appendicitis was pathologically proven in 158 patients. The negative appendectomy rate was 5.4%. The best radiological indicators for a positive CT for appendicitis were pericecal inflammation (88%) and appendicolith(57%). Appendiceal CT was found to have a 92% sensitivity, 99.6% specificity, and a 97.5% accuracy. There were 260 patients who had a negative CT; 243 of these were sent home. Alternative diagnoses were identified in 22% of patients. Conclusions: The liberal use of noncontrast helical CT results in a low negative appendectomy rate and a high degree of confidence that a negative CT will allow patients to be sent home safely.