Sonographic diagnosis of appendicitis: A pictorial essay and a new diagnostic maneuver

While many cases of appendicitis are easy to diagnose clinically, a significant number need further workup in the form of imaging. Ultrasound and CT are both used extensively to diagnose or exclude appendicitis, or arrive at an alternate diagnosis. Ultrasound has many advantages but can be a difficult modality to use due to, among other reasons, the anatomical variations in appendicial location. The true retrocolic appendix is particularly difficult to diagnose with ultrasound. This pictorial essay examines the ultrasound features of normal and diseased appendix and proposes a new examining station, the prone view, for visualizing true retrocolic appendicitis.