Value of 18F-FDG PET/CT combined with the same scanner HRCT in the diagnosis of pulmonary ground-glass nodules

Abstract

Objective To investigate the value of 18F-FDG PET/CT combined with the same scanner high resolution CT (HRCT) in the diagnosis of pulmonary ground-glass nodules (GGNs). Methods A total of 72 patients with pulmonary GGNs (40 cases were malignant, 32 presented benign lesions) were retrospectively analyzed and confirmed by surgical pathology or clinical follow-up. The clinical data, imaging features, maximum standardized uptake value (SUVmax) were analyzed statistically. Results Univariate analysis showed significant differences in diameter (t=4.932, P<0.001), density type (χ2=29.425, P<0.001), lobular sign (χ2= 9.626, P=0.002), spiculation sign (χ2=7.605, P=0.006), pleural indentation (χ2= 4.585, P=0.032), vascular convergence (χ2=7.605, P=0.006), and SUVmax(t=3.884, P<0.001). By contrast, no differences in gender (χ2= 0.026, P=0.873), age (t=1.417, P=0.161), vacuole sign (χ2=3.214, P=0.073), and air bronchus sign (χ2=1.664, P=0.197) were observed between the two groups in HRCT. Multivariate analysis showed that mixed density was a notable predictor of malignancy (χ2=10.261, OR=23.515, P<0.05). The receiver operating characteristic curve showed the diameter ≥11 mm and SUVmax≥0.9 as the standard reference indexes that yielded good identification accuracy. The sensitivity of HRCT, PET/CT, and PET/CT combined with the same scanner HRCT in the diagnosis of GGNs were 75.0%, 82.5%, and 90.0%, with specificity values of 81.3%, 78.1%, and 68.8% and accuracy of 77.8%, 80.6%, and 80.6%, respectively. Conclusions 18F-FDG PET/CT combined with the same scanner HRCT present certain clinical value in the differential diagnosis of GGNs by analyzing the metabolic condition and imaging characteristics. This approach can improve diagnostic sensitivity. Key words: Fluorodeoxyglucose F18; Positron-emission tomography; High resolution CT; Ground-glass nodule; Standardized uptake value