Incidence of Appendicitis When the Appendix Can't Be Seen

Signs of appendicitis on helical computed tomography (CT) scans include distended appendix, appendiceal or bowel-wall thickening, abscess formation, and periappendiceal fat stranding. Visualization of a normal, filling appendix conclusively rules out appendicitis. These authors assessed the incidence of acute appendicitis when the appendix cannot be visualized and when secondary changes associated with acute appendicitis are not found.

Abdominal helical CT scans with oral contrast that were obtained for 366 consecutive patients (239 women) with right-lower-quadrant abdominal pain were retrospectively reviewed by experienced abdominal radiologists. They identified direct and indirect signs of appendicitis and quantified the amount of periceca…