Diffusion phase-imaging in anisotropic media using non-linear gradients for diffusion encoding.

ABSTRACT: Diffusion MRI classically uses gradient fields that vary linearly in space to encode the diffusion of water molecules in the signal magnitude by tempering its intensity. In spin ensembles, a presumably equal number of particles move in positive and negative direction, resulting in approximately zero change in net phase. Hence, in classical diffusion weighted MRI with a linear gradient field, the phase does not carry any information as the incoherent motion of the spins only impacts the magnitude of the signal. Conversely, when the linear gradient field is replaced with one that varies quadratically over space, the diffusion of water molecules in anisotropic media does give rise to a change in net phase and preserves large portion of the signal around the saddle point of the gradient field.

SUBMITTER: Wochner P 

PROVIDER: S-EPMC10062566 | biostudies-literature | 2023

REPOSITORIES: biostudies-literature