ObjectiveTo investigate the clinical characteristics and imaging signs of malignant solitary pulmonary nodule(SPN) to analyze the malignant risk factors, in order to improve the early detection rate of lung cancer.

MethodsThe clinical and imaging data of 43 patients with SPN were analyzed using single factor analysis, and the statistical significance factor between benign and malignant groups was screened.These factors were multiplely analyzed using binary logistic regression analysis, and the independent influencing factors in benign and malignant SPN were screened.

ResultsAmong 43 patients with SPN, 18 benign cases(41.9%) and 25 malignant cases(58.1%) were identified.The single factor analysis of benign and malignant solitary pulmonary nodules showed that the malignant rates of nodules with lobulation, burr sign, vascular cluster sign, bronchial sign, pleural indentation sign and no straight edge in CT images in female patients were higher(P < 0.05 to P < 0.01).Multiple-factor logistic regression analysis showed that blur sign was the independent risk factor of malignant SPN(P < 0.01), and the straight edge was the independent protective factor of benign SPN(P < 0.05).

ConclusionsThe imaging features of benign and malignant SPN overlap.The blur sign is the independent risk factor of malignant SPN, and the straight edge is the independent protective factor of benign nodules.