Objective To investigate the differential diagnostic value of CT scan minimum attenuation values (minAVsCT) in adrenal adenomas and non-adenomas.Methods CT scan data of 89 cases of clinical and pathologically confirmed adrenal adenomas were subjected to retrospective analysis and compared with data of 46 cases involving 50 non-adenomas (25 metastases,20 pheochromocytomas,3 lymphomas,and 2 cortical carcinomas).The distributions of mean attenuation values (meanAVs) ￥ 10 Hu and minAVs ￥0 Hu and CT histogram analysis with ≥ 10％ negative pixels were observed in adrenal adenomas and non-adenomas,and the diagnostic sensitivity and specificity of these 3 methods for adenomas were calculated.Results The distributions of unenhanced meanAVs ￥ 10 Hu,minAVs ￥0 Hu,and CT histogram analysis with ≥ 10％ negative pixels among cases of adenoma and non-adenoma were 62.9％ (56/89) and 0％ (0/50) (x2=52.687,P=0.000),84.3％ (75/89) and 2％ (1/50) （x2=83.917,P=0.000),and 77.5％ (69/89) and 0％ (0/50) (x2=83.917,P=0.000),respectively.The respective diagnostic sensitivities,specificities,false negative rate (FNR),false positive rate (FPR),positive pre dictive value (PPV),negative predictive value (NPV) and accuracy of these 3 methods for adenomas were 62.9％vs 84.3％ vs 77.5％,100％ vs 98.0％ vs 100％,37.1％ vs 15.7％ vs 22.5％,0 vs 2％ vs 0,100％ vs 98.7％ vs 100％,60.2％ vs 77.8％ vs 71.4％,and 76.3％ vs 89.2％ vs 85.6％.Conclusion Although the specificity and PPV of minAVs≤0Hu is slightly less than meanAVs≤10Hu and CT histogram analysis with ≥ 10％ negative pixels,it exhibits the best sensitivity and accuracy with a simple operation,and is thus suitable for clinical application.