Self-localization in US of appendicitis: an addition to graded compression.

Graded-compression ultrasound (US) of the right lower quadrant (RLQ) has been a valuable addition to the diagnostic evaluation of acute appendicitis. In an effort to expedite the sonographic evaluation and improve diagnostic accuracy, a method of self-localization was added to the standard graded-compression examination. A total of 236 patients with signs of appendicitis were studied. Eighty-five percent (121 of 142) of the patients with proved appendicitis were able to decisively self-localize their pain. Of the patients without appendicitis who still had significant disease in the RLQ, 88% (29 of 33) were able to self-localize their pain, with an accuracy rate of 86% for significant disease. Among patients without significant disease, only 15% (nine of 61) self-localized their pain. This "sonographic self-localization sign" reduced the time of the examination and was a valuable addition to standard graded-compression US of the appendix.