Jakub P. Piatkowski1, Amos J. Storkey1, Mark E. Bastin2
1School of Informatics, University of Edinburgh, Edinburgh, UK; 2Medical Physics, University of Edinburgh, Edinburgh, UK
Anisotropy in the water diffusion MRI (dMRI) signal can be used to determine local white matter (WM) direction and segment major pathways using tractography. It has also been linked, in the form of fractional anisotropy (FA), to WM coherence and therefore, indirectly, to WM integrity. It has been shown, however, that in partial volume (PV) voxels FA is underestimated compared with voxels containing only WM. This can lead to an inaccurate estimation of either tract volume or coherence. We address this problem by fitting a fully physically plausible, 2-compartment model to the dMRI data that correctly describes PV effects.