Abstract
Sixty-five children under 12 years of age undergoing abdominal ultrasonography (US) under a suspecion of acute appendicitis during the past 2 years and 10 months were allocated to two groups, namely, appendectomy-inapplicable group (group A, 30 cases) and appendectomy-applied group (group B, 35 cases), to study the availability of US diagnosis retrospectively. We designated that US diagnosis criteria for operable acute appendicitis should depend on a visualized appendix echo and include at least one of the following conditions: 1) to have an outer diameter of 10 mm or more; 2) to have triple layer structure of the wall; 3) to associate high echo level surrounding the appendix echo; 4) to associate fluid collection surrounding it; and 5) to have a fecal stone internally. Appendix echo could be visualized at as high as 91.4% in group B, and its average outer diameter was 10.0 mm in group A or 13.1 mm in group B. The diameter increased with an advance in inflammation. Visualization of the triple layer structure, high echo level, and fecal stone could be seen in only group B, accordingly these 3 findings were considered definitive factors for operation. Fluid echo visualization was important as an indirect finding. This US diagnosis criteria in decision-making for operation led to a high correct diagnosis rate with the sensitivity and specificity of 88.5% and 90.0%, respectively.