Solitary pulmonary nodule: preliminary study of evaluation with incremental dynamic CT.

Abstract

To use incremental dynamic computed tomography (CT) to evaluate solitary pulmonary nodules (SPNs). Thirty-two adult patients with SPNs less than 3 cm in diameter had 18 primary lung cancers, 10 tuberculomas, and four hamartomas. The CT numbers of the inner area of the nodule were calculated before and 30 seconds, 2 minutes, and 5 minutes after administration of contrast material. All lung cancers and one of four hamartomas showed significantly greater enhancement (P < .0001) than benign SPNs, which did not show enhancement (except for one hamartoma). All lung cancers and one of four hamartomas showed complete enhancement, one hamartoma showed peripheral enhancement, two hamartomas and eight of 10 tuberculomas showed capsular enhancement, and two tuberculomas showed no enhancement. Maximum attenuation of 20-60 HU appears to be a good predictor of malignancy.