[Virtual bronchoscope system]

In this article, we describe the features of Virtual Bronchoscope System(VBS) and its practical use. VBS is constructed based on 3-D chest CT images. The bronchus region is automatically extracted from 3-D chest CT images by a three-dimensional region growing method. The surface rendering is employed for construction of virtualized tracheo-bronchial tree. It gives us an environment where we can observe inside the bronchi from an arbitrary viewpoint and a view direction. By mouse operation, the user can control the viewpoint and the view direction to fly through inside the airway in real time. VBS is applicable for a variety of purposes such as diagnosis, surgical planning, informed consent, education and training. One of extension of this system is a teaching tool for medical students. In the module for educational use, we have developed four functions for using the system as a teaching tool as follows: (a) automated display of bronchial anatomical names, (b) presenting questions about the currently observed branch in the endoscopic view, (c) display of the path which the user should follow, and (d) display of a question about the location of the artificially created tumor in the bronchus. These functions use the processed results of automated anatomical labeling. The method proposed here combines the knowledge based processing technique 'automated labeling of bronchial branch' and the novel visualization technique 'virtual bronchoscope'. This is one of new teaching tools of medical images. We conclude that this virtual bronchoscope system might have an important role in the medial students' education.