Cortical Diffusion Imaging
Diffusion anisotropy measurements are most commonly exploited for the purpose of mapping white matter structural connections. At conventional diffusion MRI resolutions (8-27 mm3 voxels) grey matter (GM) does not exhibit a coherent pattern of diffusion anisotropy. Only recently, as diffusion studies have started to push to higher spatial resolutions, have cerebral cortical GM diffusion anisotropy patterns have been revealed in the mature human brain.
These preliminary data depicting coherent patterns of diffusion anisotropy in the cerebral cortex demonstrate that although the fibers patterns in the cortex are extremely complex, when averaging across an MRI voxel volume, there are two diffusion orientations that dominate: perpendicular and parallel to the orientation of the cortical surface. This observation is in agreement with what is known from classical histology-based cortical architectonics. Cell bodies at different cortical depths are connected to form distinct functional columnar units (perpendicular to the cortical surface) and axons and dendrites also spread tangential (parallel) to the cortical surface along the cortical laminae (e.g. the inner and outer stripes of Baillarger).
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Neuroimage, 2013, 69:87-100.
In Vivo Characterization of the Radial and Tangential Diffusion Patterns in Human Cerebral Cortex.
Tian Q, Leuze C, Yang G, Polimeni J, McNab JA.
Annual Meeting of the Organization for Human Brain Mapping, Geneva, Switzerland, June 2016.
In Vivo Measurement of Intra-Voxel Crossing Fibers in the Cerebral Cortex Using Diffusion MRI.
Tian Q, Leuze C, Rokem A, McNab JA.
International Society for Magnetic Resonance in Medicine Annual Scientific Meeting: Toronto, Canada, June 2015.
McNab JA, Jbabdi S, Deoni SCL, Douaud G, Behrens TEJ, Miller KL
NeuroImage, 2009, 46(3):775-785.
Miller KL, Stagg C, Douaud G, Jbabdi S, Chance S, Esiri M, Voets NL, Jenkinson N, Aziz TZ, Jenkinson M, Smith SM, Johansen-Berg H, McNab JA
NeuroImage, 2011, 57(1):167-181.
Leuze CW, Anwander A, Bazin P-L, Dhital B, Stuber C, Reimann K, Geyer S, Turner R
Cerebral Cortex, 2014 Feb;24(2):328-39.