Appendicitis: should diagnostic imaging be performed if the clinical presentation is highly suggestive of the disease?

Abstract

Background & aims: Our aim was to investigate whether diagnostic imaging is required if the clinical presentation suggests acute appendicitis with high probability.

Methods: On the basis of clinical findings, 350 consecutive patients with clinical suspicion of acute appendicitis were prospectively divided into 3 groups as follows: low, intermediate, and high probability of having appendicitis. All patients then underwent diagnostic ultrasonography. The clinical likelihood of appendicitis and the ultrasonographic results were correlated with the definite diagnoses.

Results: In the patients with clinically low probability of having appendicitis, appendicitis was present in 10% (11 of 109 patients), and, in those with intermediate probability, appendicitis was present in 24% (23 of 97 patients). Patients with clinically high probability of having appendicitis had appendicitis in 65% (94 of 144 patients), an alternative diagnosis in 18% (26 of 144 patients), and no specific definitive diagnosis in 17% (24 of 144 patients). Ultrasonography diagnosed appendicitis and the differential diagnoses with a sensitivity of 98% and 97%, specificity of 98% and 100%, positive predictive value of 96% and 99%, negative predictive values of 99% and 99%, and accuracy of 98% and 99%, respectively.

Conclusions: Even in patients with clinically high probability of acute appendicitis, diagnostic imaging should be performed because it accurately depicts a high percentage of normal appendices and differential diagnoses.