Imaging features and clinical value of ~(18)F-FDG PET/CT for the diagnosis of lung pure ground glass opacity

Objective To investigate the characteristic PET/CT features in differentiation of pulmonary neoplastic diseases which appear as pure ground glass opacity.Methods Thirty six cases of neoplastic diseases(including 11cases of adenocarcinomas,2cases of bronchioloalveolar carcinoma,3cases of inflammation,3cases of atypical adenomatous hyperplasia,and 15cases of other benign lesions),which appeared as focal ground glass opacity were collected,and the gender constitution,smoking status,FDG metabolism and morphologic characteristics of lesions,were analyzed.Results The numbers of females and non-smokers were significantly larger than those of males and smokers.All the lesions were classified into two groups including≤10mm,10～15mm and15mm in size.In 10～15mm group,the common nature of disease was adenocarcinomas,atypical adenomatous hyperplasia and bronchioloalveolar carcinoma,while in 15 mm group,the common diseases were atypical adenomatous hyperplasia.All the lesions with air bronchogram were classified into two groups including malignant lesions and benign lesions.There was asignificant difference in constituent ratio of different nature of lesion between two groups.All the SUVmax value of the lesions were classified into two groups including ≤0.5and0.5.There was asignificant difference in constituent ratio of different nature of lesion between two groups.In≤0.5group,the common nature of disease was atypical adenomatous hyperplasia and other benign lesions,while in 0.5group,the common diseases were malignant lesions including adenocarcinomas and bronchioloalveolar carcinoma.In 15cases of lung cancer,only two cases were misdiagnosed as benign by PET/CT,with misdiagnosis rate of 13.3% and accuracy rate of 86.7%.Conclusion Air bronchogram is one of the most important signs of malignant lesions.SUVmax value plays an important role for the identification of pure ground glass opacity,high-resolutionCT combined with 18FFDG-PET/CT scan play an important role in the lung pGGO diagnosis and differential diagnostic application.