[Acute appendicitis: to image or not to image?].

Acute appendicitis is frequently clinically suspected. However, about 50% of emergency room patients with such a diagnosis do not have acute appendicitis and between 20-25% of patients undergoing appendectomy based on clinical diagnosis have a normal appendix. On the other hand, if left untreated acute appendicitis may result in peritonitis. The purpose of this article is to review the indications for imaging patients with clinical suspicion of acute appendicitis, to describe the US and CT features of acute appendicitis, to review the advantages and limitations of US and CT, and to present the differential diagnosis to be considered in patients with right lower quadrant pain.