# Real Color Model of a Cadaver for Deep Brain Stimulation of the Subthalamic Nucleus
## 1 Introduction  
Deep brain stimulation (DBS) of the subthalamic nucleus is used for treating [PERSON]'s disease and essential tremor [1, 2]. In DBS surgery, the neurosurgeon navigates from the skin to the target structures of the deep brain (e.g., the subthalamic nucleus) based on magnetic resonance images (MRIs) in a probe's eye (vertical plane on a DBS electrode) and trajectory (parallel plane on the DBS electrode) planes with classical (horizontal, coronal, and sagittal) planes. On the navigation planes, they need to assess not only the overall progress of electrode insertion but also the spatial relationship between the electrode tip and nearby anatomical structures [3, 4, 5, 6]. On the other hand, owing to the small size of the target structures for the DBS, even a minute misplacement of the electrode can have adverse effects [7]. Moreover, perforation of the lateral ventricle [8] or hemorrhaging [9] on occur during DBS surgery. Therefore, for successful DBS surgery, the practitioners have to be well informed of the anatomy of the deep brain.  
However, it is difficult for undergraduate medical students to comprehend DBS surgery because of the complexity of the deep brain's anatomy. For example, identifying subthalamic nuclei and their surrounding structures in horizontal, coronal, and sagittal planes could not be easy for medical students. Even though trained neurosurgeons arewell informed of the basic anatomy around the subthalamic nucleus, the probe's eye and trajectory planes for DBS surgery can be difficult to understand intuitively.  
The existing methods to learn the deep brain's anatomy for DBS surgery have shortfalls. In the case of a conventional cadaveric dissection, it is impossible to observe diverse sectional planes at narrow intervals [10]. The subcortical atlases in the Montreal Neurological Institute space that were made from MRIs and histological slides cannot show the real color of the brain [11; 12]. Recently, 7-tesla MRIs of patients were employed to depict the anatomical structures regarding DBS surgery [13]. Even though the resolution of the MRI is improved, images with real color and a high resolution can help novices to interpret an oblique MRI. Histological slides are too small to observe gross structures that the neurosurgeon needs to observe in real surgery. Therefore, an alternative method that can yield diverse sectional planes, the real color of the brain, and a high resolution is needed.  
The aim of this study was to present a real color volume model which can help medical students learn the sectional anatomy of DBS surgery. In this study, from true color sectioned images of a human head [14], volume models were made. From the volume models, images of the probe's eye and trajectory planes with classical planes were reproduced. Retrospective comparison between the color images and the images of the patients who underwent the DBS surgery can help novices to understand the oblique planes of the brain and interpret patient images. Furthermore, even experienced neurosurgeons can obtain ideas for novel surgical methods by observing oblique cadaver images which differ from other sources. This study is expected to add detailed and a realistic anatomical interpretation to DBS surgery that has been improved over the course of decades.