Back to Program | 2010 Program and Abstracts Overview | 2010 Posters

Objective: Our investigations on a porcine liver model adress the integration of a clinically applicable navigation system for enhancing spatial orientation during complex hepaticresections.Methods: The system being developed consists of an interface to preoperative planning (MeVis Distant Services) and contains an integrated ultrasound transducer (Terasion 8lOA), and an optical tracking system (NDI Vicra/Atracsys InfiniTrack) for spacial referencing of transducers and surgical instruments. The navigated ultrasound is used for acquiring 3D-information on organ motion during surgery for updating the planning data. The actualised planning datasets are then visualised together with navigated surgical tools. This enables tool guidance and provision of information on the location of critical structures. For data aquisition controlled deformations were induced on porcine livers with simulated blood flow during image aquisition by CT scanner. Ultrasound images were acquired using a calibrated and optically tracked ultrasound probe. From the resulting CT datasets, portal and hepatic veins where segmented semi-automatically using a 2D region-growing algorithm. Surface models were created and vessel centerlines were calculated using a skeletonization algorithm. The ultrasound images were segmented using our automatic vessel segmentation algorithm which provides a parametric vessel representation. Results: The deformation predicted from ultrasound imaging can be validated quantitatively using the corresponding CT dataset to develop an integrated hardware/software framework for navigation and interactive display. Conclusion: Computer assisted surgery is the future of liver surgery by combining CT scans with real time ultrasound images allowing the surgeon to identify the exact position of surgical instruments