Marco Palombo1,2, Clémence Ligneul1,2, and Julien Valette1,2
We investigate how metabolite diffusion measured up to
very high b (60 ms/µm2) at relatively
short diffusion time (63.2 ms) in the mouse brain can be explained in terms of
simple geometries. We model cell fibers as isotropically oriented cylinders of
infinite length, and show this can account very well for measured non-monoexponential
attenuation. The only exception is NAA, for which the model extracts fiber
diameter equal to 0. We show that is theoretically and experimentally compatible
with a small fraction of the NAA pool being confined in highly restricted
compartments (with short T2), e.g. a mitochondrial pool.
