The Computer-Assisted Transbronchial Biopsy project involves the registration, without any external localization device, of a pre-operative 3D CT scan of the thoracic cavity (showing a tumor that requires a needle biopsy), and an intra-operative endoscopic 2D image sequence, in order to provide an assistance to a transbronchial puncture of the tumor. Because of the specific difficulties resulting from the processed data, original image processing methods were elaborated and a multi-level strategy is introduced. For each analysis level, the relevant information to process and the corresponding algorithms are defined. This multi-level strategy then achieves the best possible accuracy.
The results presented here demonstrate that it is possible to localize precisely the endoscopic camera within the CT data coordinate system. The computer can thus synthesize in near real-time the CT-derived virtual view that corresponds to the actual endoscopie real view.