[Acute appendicitis: preference for second ultrasound instead of CT or MRI]

To assess whether additional CT or MRI, rather than a repeat ultrasound investigation, is the most appropriate diagnostic approach for patients with clinical suspicion of appendicitis following an inconclusive first ultrasound.

Descriptive study.

Retrospective data analysis of patients admitted to ER with clinical suspicion of acute appendicitis, on whom at least one ultrasonography had been performed.

A total of 328 patients were included of which 81 patients had an inconclusive first ultrasonography. Twenty-five patients underwent a second ultrasound test, and in 17 patients a correct diagnosis could be made. The positive and negative predictive value of a second ultrasonography, following an inconclusive first one was 97% and 99% respectively.

Following an inconclusive first ultrasonography in patients suspected of having acute appendicitis, a second ultrasound after an observation period can be considered, rather than opting for additional CT or MRI imaging.