[CT virtual bronchoscopy in the diagnosis of central lung cancer]

To evaluate the clinical application of CT virtual bronchoscopy(VB) in the diagnosis of centrally located lung cancer.

Forty-five cases confirmed by fiberoptic bronchoscopy and pathology underwent volume scanning using spiral CT (HiSpeed Advantage CT/i. GE Medical Systems, U.S.A). The patients examined included 33 with central lung cancer, 8 with post-operative residual bronchial stumps, 2 with post-radiotherapy lung cancer, and 2 with tracheal carcinoma. Data were transferred to computer workstation (GE Advantage Windows 3.1) and CT virtual bronchoscopic (CTVB) images with pseudocolor encoding were generated using Navigator Smooth soft-ware.

CTVB could reveal 100% segmental bronchus and 80% subsegmental bronchus simulating fiberoptic bronchoscopy. The tumors appeared as masses or nodules, causing bronchial wall thickening and occlusions. Post-operative residual bronchial stumps showed smooth end without recurrence of tumors or appeared as nodular protrusion if tumor recurred. The post-radiotherapy bronchial wall was uneven and there was narrowing of bronchial lumen.

CTVB is a noninvasive method of observing the airway. It stimulates the images observed under fiberoptic bronchoscopy and com be used partly in lieu of it. Associated with multiplanar reformat, CTVB can demonstrate extraluminal invasion of the tumor. The limitations of CTVB are that it is not possible to observe mucosal abnormalities and perform biopsy.