Imaging acute cholecystitis, one test is enough.

BACKGROUND: Patients with right upper quadrant pain are often imaged using multiple modalities with no established gold standard. A single imaging study should provide adequate information for diagnosis. METHODS: A multicenter study of patients with acute cholecystitis was queried for patients who underwent multiple imaging studies on admission. Parameters were compared across studies including wall thickness (WT), common bile duct diameter (CBDD), pericholecystic fluid and signs of inflammation. Cutoff for abnormal values were 3 mm for WT and 6 mm for CBDD. Parameters were compared using chi-square tests and Intra-class correlation coefficients (ICC). RESULTS: Of 861 patients with acute cholecystitis, 759 had ultrasounds, 353 had CT and 74 had MRIs. There was excellent agreement for wall thickness (ICC = 0.733) and bile duct diameter (ICC = 0.848) between imaging studies. Differences between wall thickness and bile duct diameters were small with nearly all <1 mm. Large differences (>2 mm) were rare (<5%) for WT and CBDD. CONCLUSIONS: Imaging studies in acute cholecystitis generate equivalent results for typically measured parameters.