Effect of Multishell Diffusion MRI Acquisition Strategy and Parcellation Scale on Rich-Club Organization of Human...

Area of Science:

• Neuroscience
• Medical Imaging
• Network Science

Background:

• Human brain structural connectivity studies commonly use single-shell diffusion-weighted imaging (DWI).
• Advances enable multishell DWI for better white-matter microstructure characterization.

Purpose of the Study:

• To investigate how diffusion MRI acquisition strategy and parcellation scale affect brain structural organization and network topology.
• To compare single-shell and multishell DWI protocols and various parcellation scales.

Main Methods:

• Graph-theoretical network analysis on DWI data from 35 subjects.
• Comparison of four single-shell and multishell sampling schemes.
• Evaluation using six parcellation scales and five graph metrics, including rich-club analysis.

Main Results:

• Parcellation scale significantly impacts network attributes more than imaging protocol.
• Multishell DWI with high b-values improves tractography, especially at crossing fibers.
• Multishell acquisition yields shorter characteristic path lengths, higher global efficiency, and lower modularity.

Conclusions:

• Both parcellation scale and sampling protocol significantly influence brain structural network organization and rich-club properties.
• Caution is advised regarding the reproducibility of connectivity findings due to variations in parcellation scale and sampling scheme.