CT Evaluation of Solitary Pulmonary Nodule

ABSTRACT

PURPOSE: To evaluate criteria for differentiating benign versus malignant solitary pulmonary nodules (SPNs) by analyzing their morphology and perinodular parenchymal changes on CT/HRCT. MATERIALS AND METHODS: We retrospectively reviewed the CT/HRCT in 99 patients with SPN. Sixty two cases were proved by surgery, PCNA, clinical follow up and etc. Thirty seven cases were diagnosed by typical benign calcification. We defined SPN as a discrete, single lesion in the lung with margins that are sharp enough to permit measurement of diameter. We excluded lesions more than 4cm in diameter and lesions with cavity from our study protocol. The study included 41 malignant nodules and 58 benign nodules. RESULTS: Mean diameter of malignant nodule was 2.9cm, benign nodule was 2.2cm. Peripheral location of nodule was 28 in malignant nodules, 50 in benign nodules. Typical benign calcification was observed in 37 tuberculoma and three hamartoma. Lobulated margin was noted in 32 malignant nodules and 14 benign nodules. Spiculated margin was observed in 17 malignant nodules and 20 benign nodules. Low attenuation within the nodule was observed in 14 malignant nodules and 12 benign nodules. Pleural tail was observed in 14 malignant nodules and 31 benign nodules. Air bronchogram was noted in 18 malignant nodules and 4 benign nodules. Juxta nodular tuberculosis was observed in 6 malignant nodules and 29 benign nodules. CONCLUSION: Malignant nodules were larger than benign nodules and more commonly demonstrated a Iobulated contour and air bronchogram (p<0.05). Benign nodules more commonly demonstrated low density in the nodule and associated with juxta nodular tuberculosis and peripheral location (p<0.05). Spiculated margin and pleural tail were not helpful to differentiate benign from malignant nodule.