Abstract 215

Purpose: To determine accuracy and impact of US followed by focused CT on diagnosis and management of children with appendicitis.

Materials and Methods: 107 consecutive children with suspected appendicitis were evaluated with abdominal US. If US showed appendicitis, laparotomy was performed. If US was normal or inconclusive, helical CT of the pelvis was obtained using rectal contrast. Surgeons were asked to estimate the management plans before imaging, after US, and after CT. Outcomes were determined by histology in 42 patients and by clinical follow-up in 65 patients.

Results: Of 107 children, 82 underwent CT. Appendicitis was proven in 39 patients. US had a sensitivity of 59%, specificity of 96%, positive predictive value of 88%, negative predictive value of 80% and accuracy of 82%. US identified a normal appendix only in 3/68 (4.4%) patients. CT had a sensitivity of 100%, specificity of 95%, positive predictive value of 88%, negative predictive value of 100%, and accuracy of 96%. CT identified the normal appendix in 49/59 (83 children. US changed management correctly in 21% while CT resulted in a correct change in management in 71% of children (p<.01).

Conclusion: In patients with negative US, focused CT is accurate and significantly modifies management of pediatric appendicitis.