[CT diagnosis of solitary pulmonary nodule]

The CT (including HRCT) findings of solitary pulmonary nodule (SPN) were reviewed. CT currently is the imaging modality of choice for the evaluation of SPN. Important roles of CT are detecting pulmonary nodules and distinguishing malignant nodules from other benign tumors or inflammatory masses. To differentiate malignancy from benignancy, it is necessary to evaluate the CT findings of SPN, including morphology using HRCT, attenuation of the nodules using thin-section CT, and enhancement effect on contrast-enhanced CT. Also important in this distinction is the evaluation of satellite lesions around SPN and the relationships between bronchus, artery, vein, pleura, and interlobular septum. Spiral CT has greatly expanded the usefulness of CT in the evaluation of SPN and has become the imaging modality of choice for SPN by combining the advantages of a single breath-hold acquisition and improved MPR and three-dimensional reconstruction capabilities. MPR and three-dimensional images of spiral CT can also be used to display the three-dimensional relationship between SPNs and bronchus, vessels, or pleura.