RESUMO
PURPOSE: To evaluate the accuracy of ultrasonography(USG) and abdominal computerized tomography(CT) and the possibility of reducing unnecessary appendectomy rate with improvement of diagnostic accuracy using optional CT with USG. METHODS: From January 1999 to May 2003, 496 patients younger than 14 years received surgical intervention with preoperative impression of acute appendicitis. They were devided into three groups no preoperative imaging study; preoperative abdominal USG only; and USG with optional abdominal CT. Sensitivity, specificity, positive predictive value, negative predictive value and accuracy were calculated in each group, and percentage of unnecessary appendectomy was also obtained. RESULTS: Sensitivity and unnecessary appendectomy rate of group was 78.4% and 21% respectively. Sensitivity, specificity, positive predictive value, negative predictive value and unnecessary appendectomy rates of group were 96.5%, 42.8%, 85.4%, 78% and 12.2%. Sensitivity and positive predictive value of group was 100% and 98%, and no unnecessary appendectomy was performed in this group. CONCLUSION: With consideration of radiation exposure, cost, and in-hospital delay time, using optional CT with USG under optimal indication can decrease the frequency of complications and unnecessary appendectomy rates.