Evaluation of CT numbers in pulmonary nodules

We have evaluated computed tomography (CT) numbers in 52 CT scans performed on patients with 14 benign and 38 malignant pulmonary nodules, excluding patients with pleural effusion or atelectasis, and patients whose pulmonary nodules contain obvious calcifications, cavities and artifacts on plain computed tomograms. CT number based on 30 voxels in the center of nodule was calculated. CT number for primary lung cancer was 57 + 16 HU (Mean + SD), and for benign lesions it was 53 + 21 HU. CT number did not help to differentiate between these two structures. The significant relationship was no found between cell type of lung cancer and CT number. Our results suggest that the measurement of CT numbers may not yield significant clinical benefits. (author)