Appendicitis: usefulness of US in diagnosis in a pediatric population.

One hundred eighty pediatric patients with suspected appendicitis were prospectively examined with graded compression ultrasonography (US) to assess the sensitivity, specificity, and accuracy of graded compression US in the diagnosis of appendicitis in children and to compare those results with results of clinical assessment in the diagnosis of this disorder. Patients were assigned to one of three groups prior to US based on the clinical level of confidence that appendicitis was present and on the planned management decision. Of 141 patients in the low- and intermediate-clinical risk categories, 20 (14%) had appendicitis: US had a sensitivity of 100%, specificity of 97%, and accuracy of 97% in these two groups. Of 39 patients in the high-clinical risk category, 32 (82%) had appendicitis: US had a sensitivity of 81%, specificity of 86%, and accuracy of 82%. Of 52 patients with surgically proved appendicitis, the initial management decision was to discharge to home or admit for observation and further testing in 18 (35%). Results at US were positive for appendicitis in all 18 patients in the latter two categories.