FIGURE 116.1 Diagnostic algorithm for a child with suspected appendicitis (Adapted from Children’s Hospital of Philadelphia clinical pathway.) Generally, children with suspected appendicitis should undergo US as the firstline imaging modality ( Fig 116.2 ) The exception to this may be adolescent males with convincing clinical and laboratory findings of appendicitis where the patient may be confidently diagnosed without imaging US is crucial as part of the workup of adolescent females if gynecologic conditions such as ovarian cyst,