Correlation Between CT Imaging Features and Pathological Diagnosis of Ground-Glass Nodules Proven by Surgical Pathology

PURPOSE. Computed tomography (CT) screening of the lung and surgical resection of lung nodules using video-assisted thoracoscopic surgery (VATS) are the mainstay for diagnosis and surgical intervention of early lung cancer. This work investigated the morphology of ground-glass nodules (GGNs) on lung CT images and differentiated minimally invasive adenocarcinoma (MIA) and invasive adenocarcinoma (IA) from preinvasive lesions, including atypical adenomatous hyperplasia (AAH) and adenocarcinoma in situ (AIS). MATERIALS AND METHODS. Between November 2013 and December 2015, 28 lung GGNs in 28 patients (18 women and 10 men, median age = 58 years) were excised using VATS at a tertiary center in Taiwan. CT images, clinical data, and pathological reports were reviewed. The CT findings of the following GGN characteristics, namely location, size, mean attenuation, shape, margin, internal air bronchogram, bubble-like lucency, and GGN-vessel relationship, were analyzed for identification of invasive lung adenocarcinoma (including MIA and IA). The results and complications of preoperative CT-guided localization of GGNs were also analyzed. RESULTS. Among 28 lung GGNs, the final pathological diagnoses comprised 1 case of organizing pneumonia (3.57%), 3 cases of AAH (10.71%), 3 cases of AIS (10.71%), 9 cases of MIA (32.14%), and 12 cases of IA (42.86%). Significant differences among preinvasive lesions, MIA, and IA were noted with respect to both the margin and GGN-vessel relationship (p = 0.016 and 0.004, respectively). MIA tended to exhibit lobulated margins (77.77%), and IA featured lobulated (58.33%) or spiculated (41.67%) margins. Type III (44.44%) and IV (44.44%) GGN-vessel relationships were predominantly observed in MIA. A Type IV GGN-vessel relationship was the most prevalent in IA (83.33%). The cutoff diameter of 7.75 mm revealed a sensitivity of 71.4% and a specificity of 85.7%, and the cutoff value of average attenuation of −562.10 HU determined a sensitivity of 66.7% and a specificity of 71.4% in differentiating preinvasive lesions, MIA, and IA. The technical success rate of preoperative CT-guided localization in this cohort was 100%. Intervention complications were generally mild and infrequent. CONCLUSION. Mean attenuation, margin, and GGN-vessel relationship on CT images can be used to differentiate among preinvasive lesions, MIA, and IA. CT-guided localization of lung nodules is a safe and an efficient procedure.