Due to new techniques in magnetic resonance imaging, it is possible to study the fiber architecture in the living human brain. Those dataset can be visualized in 3D combined with different brain areas.
Within the framework of the interdisciplinary project "Virtual Brain", the computer scientists of JARA-HPC support the neuroscientists of the section JARA-BRAIN in researching the human Connectome. With a specific computing method, the so-called probabilistic tractography, main fiber pathways as well as narrow or crossing fiber bundles can be recognized and uncertainties in the underlying measured data determined. On the basis of the gathered data, JARA-HPC scientists create a 3D visualization of the human brain's fiber pathways, thus enabling the neuroscientists to understand the interactions of different brain areas more profoundly.
Neuroscientific research aims at understanding the structure-function relationships in the brain. Networks of communicating brain areas are required to fulfil motor, sensory and all mental and cognitive activities. The structural basis of such networks are nerve fibers connecting the partcipating brain areas. A profound knowledge about this connectivity structure of the brain is therefore necessary for understanding the computational activity of the brain.
Investigating connections in the brain
Due to new techniques in magnetic resonance imaging (MRI), it is possible to study the fiber architecture in the living human brain. Using mathematical algorithms, the course of the fiber bundles can be calculated from MRI data. To account for the inherent uncertainties of the actual course of a fiber bundle in MRI data, the method of probabilistic tractography has been established. For each voxel in the brain, the probability of how likely the respective fiber bundle takes its course is calculated. The visualization of the probability in 3D is an essential step for the registration of the most likely course of a fiber bundle. The possibility of using additional anatomical information within the 3D brain, for instance brain areas, provides a further useful tool to see the fiber bundle in its structural context.
The comprehension of the course of a fiber pathway in relation to its confidence is among the crucial steps of a meaningful visualization. Our volumetric rendering indicates a low probability by dark and transparent colors whereas high probabilities are represented by bright and opaque colors.
In addition to stereoscopic vision, direct interaction where the user takes an active role is an integral part of every interactive virtual reality system. Similar to the beam of a flashlight, the user can directly control the amount of anatomical structure by a 3D interaction device. Interesting parts of the probabilistic fiber pathways can be revealed and referenced with anatomical landmarks with reduced occlusion or visual clutter.
JARA|Brain: Dr. med. Dr. rer. pol. Svenja Caspers; email@example.com
JARA|HPC: Tobias Rick, Dipl.-Inform; firstname.lastname@example.org