HILAR AND MEDIASTINAL INVASION OF BRONCHOGENIC-CARCINOMA - EVALUATIONBY THIN-SECTION ELECTRON-BEAM COMPUTED-TOMOGRAPHY

The diagnostic accuracy of thin-section incremental dynamic computed t omography (IDCT) using an electron-beam scanner in evaluating hilar or mediastinal invasion of bronchogenic carcinoma was assessed. Thirty-s even patients with proven bronchogenic carcinoma, contiguous with hila r or mediastinal structures, underwent IDCT. The area of contact was s canned using 19 contiguous 3-mm thick sections during injection of con trast material. The degree of contact between mass and pulmonary arter y or vein and their distortion were recorded. Irregular thickening of the bronchial wall, soft tissue within the lumen, or distortion were u sed to determine airway involvement. Sixty-nine sites were assessed re trospectively and compared with pathology reports. The accuracy, sensi tivity, 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 o r mediastinal invasion by bronchogenic carcinoma.