Multi‐slice computed tomography characteristics of solitary pulmonary ground‐glass nodules: Differences between malignant and benign

BACKGROUND Ground-glass nodules (GGNs), which are possible precursors of lung cancer, attract increasing attention. Many studies have attempted to identify the characteristic imaging features of GGNs for their qualitative diagnosis; however, the comprehension of GGNs remains controversial. We performed this study to identify imaging characteristics helpful to the differential diagnosis of solitary GGNs. METHODS We retrospectively evaluated 112 solitary GGNs resected from 112 patients, pathologically examined after surgical resection. Imaging features of the GGNs, such as size, shape, a solid component, lobulation, spiculation, vascular convergence sign, pleural tag, and air cavity density, were assessed. Differences between malignant and benign nodules were analyzed using binary logistic regression analysis. RESULTS Of the 112 GGNs, 82 were malignant and 30 were benign. A solid component, vascular convergence sign, and a larger diameter were risk factors for malignancy, with a sensitivity, specificity, and accuracy of 93.9%, 60.0%, and 84.8%, respectively. Lobulation, spiculation, air cavity densities, and pleural tags were also important indicators of malignancy, with positive predictive values of 93.5%, 83.3%, 91.7%, and 87.2%, respectively. CONCLUSION GGNs with a solid component, vascular convergence sign, and a larger diameter are highly suggestive of malignancy. The possibility of a neoplasm should also be considered in the case of GGNs that show lobulation, spiculation, air cavity densities, or pleural tags. To obtain a comprehensive and accurate analysis of the nodules, three-dimensional reconstruction is highly recommended.