The value of 18F-FDG-PET/CT in the differential diagnosis of solitary pulmonary nodules in areas with a high incidence of tuberculosis

The purpose of this study was to evaluate F-18-FDG-PET, PET/CT, and CT in the diagnosis of benign or malignant solitary pulmonary nodules (SPNs) in areas with a high incidence of TB. Ninety-six patients with a SPN smaller than 30 mm were studied prospectively. PET/CT images were obtained 60 min after intravenous injection of F-18-FDG. The data obtained for each patient were analyzed and the accuracy, sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were calculated and compared using chi(2) test. The sensitivity, specificity, accuracy, PPV, and NPV in the diagnosis of SPN were 86.7, 72.2, 81.3, 83.9, and 76.5%, respectively, for CT and 88.3, 61.1, 79.1, 79.1, and 75.9%, respectively, for PET. Tuberculosis was responsible for 57.1% (8/14) of false-positives on PET. The sensitivity, specificity, accuracy, PPV, and NPV in the diagnosis of SPN were 96.7, 75.7, 88.5, 88.1, and 94.4% for PET/CT. The accuracy of PET/CT was higher than that of either CT or PET alone (P < 0.05). PET has a high false-positive rate in areas with a high incidence of TB; combined PET and CT (PET/CT) can improve the diagnostic accuracy in the differentiation of an SPN.