Suspected appendicitis in children: rectal and intravenous contrast-enhanced versus intravenous contrast-enhanced CT.

PURPOSE: To retrospectively compare the diagnostic performance of intravenous contrast material-enhanced computed tomography (CT) with that of intravenous and rectal contrast-enhanced CT in the evaluation of children suspected of having appendicitis by using pathologic findings, surgical findings, or a follow-up telephone call as the reference standard.

MATERIALS AND METHODS: This HIPAA-compliant study was approved by the committee on clinical investigations. As part of a larger study, informed consent was obtained from all parents and from all children older than 7 years. Consecutive patients aged 5-21 years who presented to the emergency department and were suspected of having appendicitis were studied with CT. From April 2003 until February 2004, patients underwent intravenous and rectal contrast-enhanced CT. From March 2004 until December 2004, patients underwent intravenous contrast-enhanced CT. Demographic data, clinical outcomes, and test performance characteristics--including sensitivity, specificity, accuracy, and negative and positive predictive values--were compared.

RESULTS: Of the 416 patients who met inclusion criteria, 223 underwent intravenous and rectal contrast-enhanced CT and 193 underwent intravenous contrast-enhanced CT. There were no differences in sex distribution (55% vs 52% male patients), frequency of appendicitis (36% vs 32%), or frequency of equivocal CT findings (4%) between the groups. Intravenous and rectal contrast-enhanced CT had a sensitivity of 92% (95% confidence interval [CI]: 85%, 97%), a specificity of 87% (95% CI: 79%, 92%), a negative predictive value of 94% (95% CI: 90%, 98%), and an accuracy of 89% (95% CI: 85%, 93%). Intravenous contrast-enhanced CT had a sensitivity of 93% (95% CI: 84%, 97%), a specificity of 92% (95% CI: 85%, 96%), a negative predictive value of 95% (95% CI: 90%, 99%), and an accuracy of 92% (95% CI: 88%, 96%) (P > .2 for all comparisons).

CONCLUSION: There was no significant difference between the performance of intravenous contrast-enhanced CT and that of rectal and intravenous contrast-enhanced CT in children suspected of having appendicitis.