Unenhanced limited CT of the abdomen in the diagnosis of appendicitis in children: comparison with sonography.

OBJECTIVE: The purpose of this investigation is to determine the sensitivity, specificity, and accuracy of unenhanced limited CT of the abdomen in children with suspected appendicitis and compare these results with graded compression sonography.

MATERIALS AND METHODS: Seventy-six children underwent unenhanced limited CT over a 11-month period for evaluation of suspected appendicitis. A historical cohort of 86 consecutive children who had undergone graded compression sonography was identified. Results were correlated with surgical, pathologic, chart, and clinical follow-up data. The sensitivity, specificity, accuracy, rate of alternate diagnosis, time to perform examinations, and charge at our institution were determined for unenhanced limited CT and sonography.

RESULTS: Sensitivity, specificity, and accuracy for unenhanced limited CT were 97%, 100%, 99%, respectively, and were 100%, 88%, 91%, respectively, for sonography. Alternate diagnoses were suggested in 35% and 28% children without appendicitis who had unenhanced limited CT and sonography, respectively. Unenhanced limited CT required 5 min and sonography required 20-30 min to perform. The charge at our institution was $408 for unenhanced limited CT and $295 for sonography.

CONCLUSIONS: CT can be performed rapidly in children without IV, oral, or rectal contrast medium. Unenhanced limited CT and sonography are highly sensitive, specific, and accurate in the evaluation of children with suspected appendicitis.