Navigational aids for real-time virtual bronchoscopy.

OBJECTIVE: Virtual bronchoscopy is a recently described technique for performing simulated bronchoscopy using data obtained from thin-section CT scans of the airways. Although the detail visible during virtual bronchoscopy can be striking, the lack of global context and physical cues can lead to disorientation for the radiologist, especially during real-time "fly-throughs." We investigated the use of seven software tools (coordinate axes, global maps, trail markers, cross-references to standard two-dimensional projections, rear-view windows, collision avoidance, and stereoscopic displays) that are navigational aids to overcome such disorientation.
CONCLUSION: The navigational aids performed satisfactorily on virtual bronchoscopy studies from 21 patients. A frame rate of one to seven frames per second, depending on the complexity of the bronchial model, could be attained. Several of the aids worked best when used selectively or when updated frequently but not continuously. Navigational aids are potentially useful for guiding radiologists who do virtual bronchoscopy studies. Such aids are general tools that may be applicable to other types of virtual endoscopy.