What imaging finding would exclude appendicitis?A) A computed tomographic (CT) scan with a nonvisualized appendix
Graded compression ultrasonography is inexpensive and rapid. The appendix is identified as a nonperistaltic, blind ending loop of bowel. The compressibility and anteroposterior dimensions are measured. Thickening of the wall as well as peri-appendiceal fluid with a noncompressible appendix are suggestive of appendicitis while an easily compressible, narrow appendix excludes the diagnosis. Failure to identify the appendix on imaging does not definitely rule out appendicitis. A fecalith in the mid appendix may allow proximal filling of the appendix with barium in the presence of appendicitis. Sonographic sensitivity for appendicitis is 55 to 96% while specificity is 85 to 98%.