In those with CRP < 3 mg/dL, further classification by gangrene and GB wall HU value refined the prediction: patients without gangrene had a 45% chance of uncomplicated disease (probability 0.32), whereas those with gangrene and GB wall HU value ≥ 80 had a high probability (0.73) of complicated cholecystitis. Here, CRP is linked to Cholecystitis.