Preoperative Prediction of Gangrenous Cholecystitis Using CT and MRI Findings: A Retrospective Observational Study in a Single Emergency Center

Abstract Background Gangrenous cholecystitis is a severe form of acute cholecystitis that requires prompt surgical intervention. While ultrasound is often the first-line diagnostic tool, CT and MRI are increasingly utilized for their superior diagnostic accuracy. However, reliable imaging markers for predicting gangrenous cholecystitis remain unclear. Objectives To identify preoperative CT and MRI findings that are predictive of gangrenous cholecystitis in patients with acute cholecystitis. Methods We conducted a retrospective observational study of 119 patients with acute cholecystitis who underwent CT or MRI prior to surgery between January 2020 and March 2025. Patients were divided into two groups: gangrenous cholecystitis and non-gangrenous cholecystitis, based on postoperative histopathology. Clinical characteristics, laboratory data, and imaging findings were compared. Multivariate logistic regression and ROC analysis were performed to identify independent predictors of gangrenous cholecystitis and evaluate diagnostic performance. Results Fifty patients were diagnosed with gangrenous cholecystitis and 69 with non-gangrenous cholecystitis. CT findings significantly associated with gangrenous cholecystitis included gallbladder wall thickening, pericholecystic stranding, pericholecystic fluid, intraluminal bile attenuation ≥ 12.5 HU, gallbladder wall attenuation ≥ 31.5 HU, solution of continuity, and free peritoneal effusion. Multivariate analysis identified intraluminal bile attenuation ≥ 12.5 HU (aOR: 12.80), gallbladder wall attenuation ≥ 31.5 HU (aOR: 5.82), and pericholecystic stranding (aOR: 4.35) as independent predictors. Among biomarkers, neutrophil count (AUC = 0.820), CRP (AUC = 0.782), and D-dimer (AUC = 0.791) demonstrated high diagnostic performance. Conclusions Gallbladder wall and intraluminal bile attenuation values on non-contrast CT and pericholecystic stranding are practical, objective imaging predictors of gangrenous cholecystitis. These findings can facilitate early risk stratification and surgical decision-making in the emergency setting without the need for contrast agents.