CEACAM5 and cholecystolithiasis: In general, 18F-FDG PET metabolic parameters are still defective in differentiating nonmetastatic GBC from cholecystitis, but the multiparameter diagnostic model composed of 18F-FDG PET metabolic parameters (SUVR) and clinical variables, including patient signs (fever), medical history (cholecystolithiasis) and laboratory examination (CEA > 5 ng/ml), has good diagnostic efficacy in the differential diagnosis of nonmetastatic GBC and cholecystitis.