Marco Reisert1,
Matthias Weigel2, Els Fieremans3, Valerij G. Kiselev2,
Dmitry S. Novikov4
1Dpt.
of Radiology, Medical Physics , University Medical Center Freiburg, Freiburg,
BW, Germany; 2Dpt. of Radiology, Medical Physics, University
Medical Center Freiburg, Freiburg, BW, Germany; 3Center for
Biomedical Imaging, Dpt. of Radiology, New York University, New York, NY,
United States; 4Center for Biomedical Imaging, Dpt. of Radiology,
New York University School of Medicine, New York, NY, United States
As the inverse problem of quantifying tissue structure in every voxel is highly ill-posed, we regularize it by unifying sub-voxel modeling of dMRI signal at the mesoscopic scale with multi-voxel connectivity achieved with global fiber tracking. When MesoFT converges, we obtain the physically motivated fiber directions, connections, voxel-wise neurite densities, and, in principle, can incorporate other mesoscopic structural parameters. In particular, MesoFT yields strong anisotropy of extra-axonal diffusion and a notable tortuosity in corpus callosum.