Hilar and mediastinal invasion of bronchogenic carcinoma: evaluation by thin-section electron-beam computed tomography.

The diagnostic accuracy of thin-section incremental dynamic computed tomography (IDCT) using an electron-beam scanner in evaluating hilar or mediastinal invasion of bronchogenic carcinoma was assessed. Thirty-seven patients with proven bronchogenic carcinoma, contiguous with hilar or mediastinal structures, underwent IDCT. The area of contact was scanned using 19 contiguous 3-mm thick sections during injection of contrast material. The degree of contact between mass and pulmonary artery or vein and their distortion were recorded. Irregular thickening of the bronchial wall, soft tissue within the lumen, or distortion were used to determine airway involvement. Sixty-nine sites were assessed retrospectively and compared with pathology reports. The accuracy, sensitivity, and specificity in evaluating invasion of the pulmonary artery were 75.0%, 77.8%, and 71.4%, respectively. Limited reliability also was found for invasion of the main bronchus and "secondary" carina, with accuracies of 66.7% and 70.5%, sensitivities of 75.0% and 70.0%, and specificities of 57.1% and 71.4%, respectively. Thin-section IDCT with electron beam scanner is not accurate in the detection of hilar or mediastinal invasion by bronchogenic carcinoma.