Obscured appendiceal wall on unenhanced CT: A sensitive indicator for the diagnosis of complicated appendicitis

Objectives To retrospectively evaluate the potential role of an obscured appendiceal wall on unenhanced CT in the preoperative prediction of complicated appendicitis. Methods This retrospective study was approved by our institutional review board, and informed consent was waived. A total of 57 patients with surgically and pathologically confirmed appendicitis were analyzed from January 1, 2021, to June 30, 2024. The obscured appendiceal wall was assessed alongside four other specific CT findings and clinical data. Univariate statistical analyses were performed to examine associations between CT signs and complicated appendicitis. Kappa statistics were calculated to assess interobserver agreement. Results The study included 32 men (56.1%) and 25 women (43.9%) with a median age of 60 years. Of the 57 patients, 34 had uncomplicated appendicitis and 23 had complicated appendicitis. The obscured appendiceal wall showed the highest sensitivity for predicting complicated appendicitis, with a sensitivity of 81% (95% CI, 57–94%) and a specificity of 85% (95% CI, 68–94%). Interobserver agreement was fair (κ = 0.557; 95% CI, 0.341–0.773). Conclusion An obscured appendiceal wall is a sensitive and valuable indicator for diagnosing complicated appendicitis. Its detection can help reduce false-negative rates, preventing delayed diagnosis and treatment.