Mapping the microstructure of human cerebral cortex in vivo with diffusion MRI.

Area of Science:

• Neuroimaging
• Human Brain Microstructure Analysis

Background:

• Diffusion MRI has advanced white matter mapping but understanding cerebral cortical microstructure in vivo remains limited.
• The relationship between cortical microstructure and macrostructure, myeloarchitecture, cytoarchitecture, and function requires further investigation.

Purpose of the Study:

• To present comprehensive neuromaps of 21 microstructural metrics in the young adult cerebral cortex.
• To elucidate the relationship between cortical microstructure and its underlying biological and functional organization.

Main Methods:

• Utilized diffusion tensor imaging (DTI), diffusion kurtosis imaging (DKI), mean apparent propagator (MAP) MRI, and neurite orientation dispersion and density imaging (NODDI).
• Derived 21 microstructural metrics from advanced diffusion MRI techniques applied to the cerebral cortex.

Main Results:

• Identified four composite factors explaining the 21 microstructural metrics: diffusion kurtosis, isotropic diffusion, heterogeneous diffusion, and diffusion anisotropy.
• Demonstrated that cortical microstructure aligns with cytoarchitectural differentiation, macroscale axes, functional networks, neural dynamics, neurotransmitter distributions, and cognition.

Conclusions:

• Cortical microstructure is intricately linked to the brain's structural, functional, and cognitive organization.
• Advanced diffusion MRI provides a powerful tool for in vivo mapping of cortical microstructure and its relationships.