Stereotactic neurosurgery for movement disorders involves the accurate localization of functionally distinct subcortical anatomy that appears homogeneous on magnetic resonance or computed tomographic images. To aid localization of these surgical targets on patient images, we have developed a visualization oriented searchable and expandable database of functional organization representing bilaterally the sensorimotor thalamus, pallidum, internal capsule, and subthalamic nucleus. Data were obtained through microelectrode recording and stimulation mapping routinely performed during 123 functional stereotactic procedures. Electrophysiologic data were standardized using a multi-parameter coding system and annotated to their respective MRIs at the appropriate position in patient stereotactic space. To accommodate for normal anatomical variability, we have developed an intensity-based nonlinear registration algorithm that rapidly warps a patient's volumetric MRI to a high-resolution MRI average brain. The annotated functional data are subsequently transformed into the average brain coordinate system using the displacement grids generated by the algorithm. When the database is searched, clustering of like inter-patient physiologic responses within target anatomy and adjacent structures is revealed. These data may in turn be registered to a preoperative MRI using a desktop computer enabling prior to surgery interactive delineation of surgical targets. The database is expandable, fully searchable, and provides a visual 3D representation of subcortical functional organization.
Purpose: The development of new applications in medical image visualization and surgical planning requires the completion of many common tasks such as image reading and re-sampling, segmentation, volume rendering, and surface display. Intra-operative use requires an interface to a tracking system and image registration, and the application requires basic, easy to understand user interface components. Rapid changes in computer and end-application hardware, as well as in operating systems and network environments make it desirable to have a hardware and operating system as an independent collection of reusable software components that can be assembled rapidly to prototype new applications. Methods: Using the OpenGL based Visualization Toolkit as a base, we have developed a set of components that implement the above mentioned tasks. The components are written in both C++ and Python, but all are accessible from Python, a byte compiled scripting language. The components have been used on the Red Hat Linux, Silicon Graphics Iris, Microsoft Windows, and Apple OS X platforms. Rigorous object-oriented software design methods have been applied to ensure hardware independence and a standard application programming interface (API). There are components to acquire, display, and register images from MRI, MRA, CT, Computed Rotational Angiography (CRA), Digital Subtraction Angiography (DSA), 2D and 3D ultrasound, video and physiological recordings. Interfaces to various tracking systems for intra-operative use have also been implemented. Results: The described components have been implemented and tested. To date they have been used to create image manipulation and viewing tools, a deep brain functional atlas, a 3D ultrasound acquisition and display platform, a prototype minimally invasive robotic coronary artery bypass graft planning system, a tracked neuro-endoscope guidance system and a frame-based stereotaxy neurosurgery planning tool. The frame-based stereotaxy module has been licensed and certified for use in a commercial image guidance system. Conclusions: It is feasible to encapsulate image manipulation and surgical guidance tasks in individual, reusable software modules. These modules allow for faster development of new applications. The strict application of object oriented software design methods allows individual components of such a system to make the transition from the research environment to a commercial one.