Purpose: To assess the potential of CT in evaluating the histological severity of acute appendicitis in comparison with surgical and pathological findings.
Method: The CT images of 75 patients with surgically proven appendicitis, including 10 cases of catarrhal, 34 of phlegmonous, and 31 of gangrenous appendicitis, were retrospectively analyzed for the following five CT findings: (1) hazy periappendiceal densities, (2) enlarged appendix, (3) increased enhancement of the appendiceal wall, (4) increased enhancement of the periappendiceal intestinal wall, and (5) deficiency of the appendiceal wall. By comparing all the CT findings and the pathological severity of appendicitis (catarrhal, phlegmonous, and gangrenous), the prevalence of the five CT findings was calculated for each pathological category.
Results: Abnormal CT findings were noted in only one case of catarrhal appendicitis. Increased enhancement of the appendiceal wall was observed in all 29 cases of phlegmonous appendicitis (100%), but in only 66.7% (18 cases) of gangrenous appendicitis. Deficiency of the appendiceal wall was more frequently observed in gangrenous (19/27, 70.4%) than phlegmonous appendicitis (4/29, 13.8%).
Conclusion: Findings of enhanced CT provide useful information in evaluating the pathological severity of acute appendicitis.