diffusion mr introduction: a literature review

diffusion mr introduction: a literature review

in the last century, developments have led to a better understanding of diffusion, the perpetual mixing of molecules caused by thermal motion. the basic principles governing diffusion phenomena and their measurement using magnetic resonance (mr) are reviewed in this article. from basic principles, the apparent diffusion coefficient, diffusion propagator, and mr measurements are introduced. diffusion of water (or another spin-labeled molecule) encounters barriers, macromolecules, and local samples.

as a result, in mr experiments, water motion in these microenvironments contributes to the signal. it is challenging to infer features of local tissue anatomy, composition, and microstructure from mr displacement measurements in diffusion nmr and mri. it is possible to study tissue structure using mr at different length scales (ozarslan and basser, 2008 (23)), i.e., levels of hierarchical architectural organization (ozarslan et al., 2006 (24)). the mean-square displacement of water in typical mr experiments is micrometers; however, these molecular motions are ensemble averaged within voxels, after which they are assembled into multi-slice or 3d images.