Abstract: Objective To evaluate the value of differential diagnosis in solitary pulmonary nodule(SPN)with HRCT and ¹⁸F-FDG PET/CT.Methods 60 solitary pulmonary nodules were examined with ¹⁸F-FDG PET/CT and local thin-slice high resolution CT(LTHRCT,for short HRCT),all of which were proven pathologically.The diagnosis of PET/CT relied on the metabolism feature of PET and the morphology feature in low-dose CT during quiet respiration.The diagnosis of PET/CT combining HRCT considered the morphology feature of HRCT on the basis of PET/CT.Results The sensitivity,specificity,accuracy of PET/CT were 89.5%,77.3% and 85.0% respectively.accordingly,the sensitivity,specificity,accuracy of PET/CT combining HRCT were 97.4%,81.8% and 91.7% respectively.Conclusions PET/CT combining HRCT can raise the sensitivity,specificity and accuracy of PET/CT in the diagnosis of SPN.