Trial Information

Diagnostic Efficacy of Virtual Bronchoscopy

This project is a test of the efficacy of a new diagnostic method for imaging the airways
known as virtual bronchoscopy. Virtual bronchoscopy is performed by acquiring thin section
computed tomography (CT) images of the chest. These images are used to generate a three
dimensional model of the tracheal and bronchial walls on a graphics workstation in 3-D. The
model can be manipulated to allow the viewer to "fly through" the tracheobronchial tree
providing views similar to those obtained during bronchoscopy. The technique produces a
display of the human bronchial system in a readily understood format. Moreover, it allows
investigation of post-stenotic portions of the bronchial tree that are beyond the reach of
fiberoptic bronchoscopy. Further, virtual bronchoscopy may be used to guide interventional
procedures. The patients that will be studied in this protocol will be those having
inflammatory, infectious, or neoplastic pulmonary processes who would have had a chest CT
for clinical reasons. These patients will be recruited from current NIH protocols. The
study design consists of scanning of the thorax using thin section helical CT, followed by
three dimensional surface rendering of the airways and transfer of the digital data to
videotape. In one of four parts of the protocol, the virtual bronchoscopy will be compared
with results from fiberoptic bronchoscopy in a blinded study. In a second part of the
protocol, the virtual bronchoscopy will be used to perform a descriptive analysis of
cavitary lung lesions. In the third part, the utility of virtual bronchoscopy in diagnosis
of neoplastic lesions of the chest will be studied. In the fourth part, certain technical
problems in the virtual bronchoscopy procedure will be investigated. The patients will only
have fiberoptic bronchoscopy for clinically indicated purposes. We anticipate that virtual
bronchoscopy will be diagnostically efficacious for disorders which produce a morphologic
alteration in bronchial anatomy.