| Background. The success of the stereotactic surgery for Parkinson's disease depends on the accurate localization of the surgical target. The traditional target localization method measures and calculates the target position on 2D brain images. These images are selected with visual assessment. Their spatial orientations may tilt away from the expected directions, and errors can be introduced to the localization results.; Objective. To overcome the disadvantages of the existing target localization technique, a novel method has been developed, which improves the accuracy in the measurement and calculation of the target position. Also, this new method simplifies the target localization process and reduces the time needed for this procedure.; Methods. A volumetric image dataset is built from a sequence of 2D MR brain images. Ray tracing rendering techniques is used to reconstruct brain images from the volume data. The mid-sagittal, horizontal and vertical reference planes are defined in the 3D brain image dataset with an optimization algorithm named Simplex. The target coordinates in the stereotactic frame space is automatically calculated when the target is identified. The electrode trajectory is simulated with stereoscopic brain images. This new method is implemented in Visual C++ programming language on Windows NT platform.; Results. With the software that implements the new method, the configuration of the reference planes is completed with only mouse clicks on several points along the midline of the brain on the images; the target identification and its coordinates calculation are also accomplished with just mouse moving and clicking. Consistent results are obtained when target coordinates are calculated on images of different views. The new method uses 40 minutes less to get the target coordinates than the traditional localization method.; Conclusion. This new method configures optimal reference planes for target measurement and calculation, so that the accuracy of pre-operative target localization is improved. Since it combines the target identification and target coordinates calculation into one step, this software also simplifies the localization procedure and less time is required to obtain target coordinates in the stereotactic space.{09}A stereoscopic visualization of brain anatomy and electrode trajectory is a helpful tool for surgical planning.; Key Words: stereotactic neurosurgery, target localization, 3D brain image, surgical planning, Parkinson's disease, stereoscopic visualization... |
