Abstract： Objective To explore the value of characteristic parameters in 18F-FDG-PET/CT for the differen-tiation between adrenal metastases and lipid-poor adenomas.Methods The clinical and metabolic parameters of eighty-five patients(adrenal metastases 43,lipid-poor adenomas 42)with unilateral adrenal hyperattenuat-ing nodules found by 18F-FDG PET/CT in Tangshan People's Hospital from October 2022 to June 2023 were analyzed,including gender,age,the primary malignant tumor,and the size,location,CT values,and PET meta-bolic parameters of the adrenal nodules.Parameters with statistical differences were selected by univariate a-nalysis,highly correlated variables were delated,and then a diagnostic model was constructed by multiple lo-gistic regression.The receiver operating characteristic curves was used to evaluate the differential diagnostic performance of independent risk factors and diagnostic model,and the areas under the receiver operating char-acteristic curves(AUCs)differences were compared by delong analysis.Results The CT value in plain scan,SUVmax of adrenal nodules,and the primary malignant tumor are independent risk factors for predicting small metastases.Among them,plain scan CT value was the most valuable independent risk factor for differ-ential diagnosis,with the highest diagnostic performance(AUC of 0.803).The diagnostic performance of the predictive model was further improved,with an AUC of 0.905,significantly higher than that of individual in-dependent risk factors(P all＜0.05).And the accuracy and stability of the diagnostic model were further verified through random sampling.Conclusion The predictive model established based on 18F-FDG PET/CT features has high diagnostic performance for differentiating adrenal metastases and lipid-poor adenomas,pro-viding a non-invasive,efficient,and convenient diagnostic method for hyperattenuating adrenal nodules.