Multiplanar imaging system for stereotaxic neurosurgery

An imaging system to be used interactively in the operating room for stereotaxic neurosurgery is being developed at the University of Washington. System features include multiple windows displaying registered planar images from X-ray Computed Tomography (CT) and Magnetic Resonance Imaging (MRI) scanners, database capabilities, and interactive image enhancement and processing capabilities. Patients are preoperatively scanned in CT and MRI using a compatible stereotaxic localization system mounted on a patient head ring. The images are downloaded onto magnetic tape and transferred into the imaging system. The current system is an IBM PC/AT personal computer with the XENIX operating system and a custom image processing subsystem designed at the University of Washington. This system is being upgraded to a SUN 4/260 engineering workstation with a TA AC-1 image processing and graphics accelerator. Image registration within the 3-dimensional volume is done automatically by using information from the image data header generated by the source modality and from the stereotaxic frames's fiducial markers in the images. After the images have been registered, a mouse-driven cursor is made active in one window and roamed on the active plane. The image in each of the other windows is updated in real time to show the slice at the intersection of the cursor as the active slice is roamed. The active window can be changed by the operator to allow roaming in the 3-dimensional stereotaxic volume. Once the target and entry points have been chosen, stereotaxic target coordinates and guidance parameters are generated and the needle track to the target is displayed. This paper presents our algorithms, hardware and software details of the system, and the preliminary clinical results.