Multi-dimensional diffusion MRI at ultra-high gradient strength for mapping axonal architecture and microstructure in...

Area of Science:

• Neuroimaging
• Comparative Neuroscience
• Brain Anatomy

Background:

• Diffusion MRI is crucial for mapping brain connectivity.
• Previous whole-brain imaging lacked sufficient resolution for detailed analysis.
• Large-scale brain mapping initiatives require advanced imaging techniques.

Purpose of the Study:

• To generate the most comprehensive diffusion MRI dataset of macaque and human brains.
• To achieve ultra-high spatial and diffusion resolution for detailed brain structure analysis.
• To provide a valuable resource for neuroscience research and technical development.

Main Methods:

• Utilized ultra-high-gradient MRI systems, including Connectome 2.0, for post-mortem acquisitions.
• Acquired data at high spatial resolutions (0.25 mm for macaques, 0.4 mm for humans) and multiple diffusion shells (up to 64000 s/mm²).
• Optimized imaging protocols for high signal-to-noise ratio across varied b-values, diffusion times, and echo times.

Main Results:

• Achieved unprecedented detail in whole-brain diffusion MRI sampling for both species.
• Resolved white matter connectional architecture with high fidelity.
• Visualized cortical and subcortical cytoarchitectonic boundaries previously inaccessible in noninvasive imaging.

Conclusions:

• The generated dataset offers a significant advancement in brain imaging resolution and scope.
• These data will facilitate technical development in diffusion MRI.
• The resource supports basic and clinical neuroscience research by providing detailed brain atlases.