A Theoretical Model of Water Diffusion in Brain Tissue
Yablonskiy D, Jespersen S, Kroenke C, Bretthorst G, Ackerman J
Washington University, Washington University
We present a new theoretical model that reflects basic diffusion properties of brain tissue at the cellular level. Neuronal tissue (gray and white matter) is modeled as a distribution of long cylinders, and water associated with these cylinders exhibits anisotropic diffusion. Diffusion outside the neurons, in glia cells and extracellular space, is assumed isotropic on the time scale of the diffusion measurement. To test the model, 153 diffusion weighted images with varying amplitude and direction of diffusion gradients were collected from a fixed baboon brain. Considerable agreement is found between the theoretical model and experimental data.