Computing the orientational-average of diffusion-weighted MRI signals: a comparison of different techniques.

ABSTRACT: Numerous applications in diffusion MRI involve computing the orientationally-averaged diffusion-weighted signal. Most approaches implicitly assume, for a given b-value, that the gradient sampling vectors are uniformly distributed on a sphere (or 'shell'), computing the orientationally-averaged signal through simple arithmetic averaging. One challenge with this approach is that not all acquisition schemes have gradient sampling vectors distributed over perfect spheres. To ameliorate this challenge, alternative averaging methods include: weighted signal averaging; spherical harmonic representation of the signal in each shell; and using Mean Apparent Propagator MRI (MAP-MRI) to derive a three-dimensional signal representation and estimate its 'isotropic part'. Here, these different methods ar

SUBMITTER: Afzali M 

PROVIDER: S-EPMC8275746 | biostudies-literature | 2021 Jul

REPOSITORIES: biostudies-literature