A critical evaluation of US for the diagnosis of pediatric acute appendicitis in a real-life setting: how can we improve the diagnostic value of sonography?

BACKGROUND

We have observed that day-to-day use of US for acute appendicitis does not perform as well as described in the literature.

OBJECTIVE

Review the diagnostic performance of US in acute appendicitis with attention to factors that influence performance.

MATERIALS AND METHODS

Retrospective review of all sonograms for acute appendicitis in children from May 2005 to May 2010 with attention to the rate of identification of the appendix, training of personnel involved and diagnostic accuracy.

RESULTS

The appendix was identified in 246/1,009 cases (24.4%), with identification increasing over time. The accuracy of US was 85-91% with 35 false-positives and 54 false-negatives. Pediatric sonographers were significantly better at identifying the appendix than non-pediatric sonographers (P < 0.0001). Increased weight was the only patient factor that influenced identification of the appendix (P = 0.006). CT use was stable over the 5 years but declined in cases where the appendix was identified by US.

CONCLUSION

In day-to-day use, US does not perform as purported in the literature. We do not visualize the appendix as often as we should and false-negative and false-positive exams are too common. To improve the diagnostic performance of this modality, involvement by experienced personnel and/or additional training is needed.