We are developing a neurosurgical planning system, and this paper presents a method of automatic path searching from skin surface of the head to tumor inside the brain. The path obtained by our system is an optimal one in minimally invasive neurosurgery and it is calculated automatically based on a 3D atlas. The 3D atlas is a voxel based 3D matrix, and consists of two parts, structural part and knowledge part. The structural part includes the geometrical information with respect to each tissue. The knowledge part is generated based on experiences of doctors, and numeric value is provided as importance value for each tissue. The path searching consists of two steps, path finding and path smoothing. Path finding is to select an optimal path from surface of the head to the affected part based on minimization of importance value integrating along with the path. We applied the algorithm into a head MRI data set. The path obtained by path finding is reformed smoothly to approach the natural path of surgeon.
This paper described a 3D image based collaboration system for telemedicine. This system enables doctor to observe 3D images transferred from image database through network, and also has collaboration function which operate 3D position of viewing of each doctor by 3D image displaying and data transferring through network. It is constructed based on server client style, and the server has the function of transferring data from a 3D image database and a collaboration record database, and also has control unit of transferring data between doctors during operating the system. The client has a user interface including operation part for parameter selection of viewing and sending comments, and display part for displaying 3D image based on volume rendering and 3D position and direction of observer by suing avatar. Doctors can use this system to do collaboration work by sending comments with viewing 3D image each other. We implement this system in different platforms including UNIX workstation and PC, and also supply Web browser based user interface for considering various user environments. We applied the 3D images of MRI in head for examining the structure of soft tissues and tumor in detail. We also evaluated the performance of the system through network including LAN and Internet, and experimental result shows that this system is useful.