We propose to use Gaussian process regression to accurately estimate the diffusion MRI signal at arbitrary locations in q-space. By estimating the signal on a grid, we can do synthetic diffusion spectrum imaging: reconstructing the ensemble averaged propagator (EAP) by an inverse Fourier transform. We also propose an alternative reconstruction method guaranteeing a nonnegative EAP that integrates to unity. The reconstruction is validated on data simulated from two Gaussians at various crossing angles. Moreover, we demonstrate on non-uniformly sampled in vivo data that the method is far superior to linear interpolation, and allows a drastic undersampling of the data with only a minor loss of accuracy. We envision the method as a potential replacement for standard diffusion spectrum imaging, in particular when acquistion time is limited.
@article{arxiv.1611.02869,
title = {Gaussian process regression can turn non-uniform and undersampled diffusion MRI data into diffusion spectrum imaging},
author = {Jens Sjölund and Anders Eklund and Evren Özarslan and Hans Knutsson},
journal= {arXiv preprint arXiv:1611.02869},
year = {2020}
}