Evaluation of perforated and nonperforated appendicitis with CT.

Fifty-three patients with 38 cases of perforated appendicitis and 15 cases of appendicitis without perforation were evaluated based on the computed tomography (CT) appearances of appendiceal diameter, phlegmon, abscess, extraluminal air, appendiceal wall enhancement, lateroconal fascial thickening, appendicolith, bowel wall thickening, ascites, ileal wall enhancement, peritoneal enhancement, periappendiceal fluid, omental haziness, retrocecal appendix, intraluminal air, and the combination of intraluminal air and appendicolith. The result of appendiceal diameter was compared using two-sample Student's t test, and the other CT findings were analyzed by Fisher's Exact Test. Our results showed that appendix was larger in caliber in perforated appendix (P< .05). Direct CT signs (i.e., phlegmon, abscess, and extraluminal air) were more specific for perforated appendicitis (P< .05). Indirect signs (bowel wall thickening, ascites, ileal wall enhancement, intraluminal air, and combined intraluminal air and appendicolith) were also found in higher incidence in appendiceal perforation (P< .05). Appendiceal enlargement and ileal wall enhancement were the two predominant findings in one case of perforation. We concluded that direct and indirect CT appearances can differentiate appendicitis with and without perforation. Indirect signs may be helpful in difficult case.