Visualizing cortical laminar architecture in the living human brain using next-generation ultra-high-gradient...

Area of Science:

• Neuroimaging
• Human Brain Anatomy
• Diffusion MRI

Background:

• Cortical laminar microstructure is key to understanding brain function.
• Noninvasive in vivo characterization of cortical layers remains challenging.

Purpose of the Study:

• To characterize in vivo cortical laminar cytoarchitecture and myeloarchitecture using diffusion MRI.
• To demonstrate the feasibility of mapping cortical architecture noninvasively.

Main Methods:

• Utilized a high-performance Connectome MRI scanner (500mT/m gradient strength).
• Employed soma and neurite density imaging (SANDI) metrics with super-resolution.
• Performed cortical depth-dependent analyses of diffusion MRI data.

Main Results:

• Distinct laminar profiles for soma and neurite density were observed.
• Visual cortex showed higher intra-soma signal fraction than motor cortex.
• Cortical curvature showed layer-specific correlations with intra-soma signal fraction.

Conclusions:

• Noninvasive mapping of cortical laminar architecture is feasible with advanced MRI.
• SANDI metrics provide insights into in vivo cytoarchitecture and myeloarchitecture.
• This technique can serve as a surrogate for histology in future brain studies.