Clinical Significance of Follow-up CT after Ultrasonography for Acute Appendicitis in Children

Purpose: The ultrasonography (USG) and computed tomography (CT) are popular diagnostic tools for the diagnosis of acute appendicitis in children, but there are many debates about their clinical significance. The purpose of this study is to clarify the clinical significance of USG, CT and follow-up CT performed subsequently to USG, especially in perforated acute appendicitis in children. Methods: We have reviewed 419 cases of surgically confirmed acute appendicitis in children under the age of sixteen, who had been treated in Inje University Ilsan Paik Hospital from March 2002 to February 2006. All the clinical data including the results of USG and CT were collected and analyzed. Results: Sensitivity, specificity, positive and negative predictive values of USG were 98.7%, 96.8%, 98.1%, 97.8% in non-perforation group and 90.8%, 100%, 100%, 81.9% in perforation group. Those of CT were 96.4%, 100%, 100%, 96.5% and 86.6%, 100%, 100%, 87.5% respectively. Those of follow-up CT after USG were 100%, 100%, 100%, 100% and 87.5%, 100%, 100%, 92.0% respectively. The duration of using antibiotics in seven patients showed positive correlation with the interval between two imaging studies (r=0.0472, p=0.019). There was no statistical significance of correlation when these imaging studies performed within 30 hours together. Conclusion: In most of the cases, single choice between USG and CT would be enough to diagnose the acute appendicitis in children. But, it may be helpful to perform CT as early as possible subsequently to USG when there is discrepancy between initial USG and clinical impression.