Virtual cerebral ventricular system: an MR-based three-dimensional computer model.

The inherent spatial complexity of the human cerebral ventricular system, coupled with its deep position within the brain, poses a problem for conceptualizing its anatomy. Cadaveric dissection, while considered the gold standard of anatomical learning, may be inadequate for learning the anatomy of the cerebral ventricular system; even with intricate dissection, ventricular structures remain difficult to observe. Three-dimensional (3D) computer reconstruction of the ventricular system offers a solution to this problem. This study aims to create an accurate 3D computer reconstruction of the ventricular system with surrounding structures, including the brain and cerebellum, using commercially available 3D rendering software. Magnetic resonance imaging (MRI) scans of a male cadaver were segmented using both semiautomatic and manual tools. Segmentation involves separating voxels of different grayscale values to highlight specific neural structures. User controls enable adding or removing of structures, altering their opacity, and making cross-sectional slices through the model to highlight inner structures. Complex physiologic concepts, such as the flow of cerebrospinal fluid, are also shown using the 3D model of the ventricular system through a video animation. The model can be projected stereoscopically, to increase depth perception and to emphasize spatial relationships between anatomical structures. This model is suited for both self-directed learning and classroom teaching of the 3D anatomical structure and spatial orientation of the ventricles, their connections, and their relation to adjacent neural and skeletal structures.