ATLAS-BASED FIBER CLUSTERING FOR MULTI-SUBJECT ANALYSIS OF HIGH ANGULAR RESOLUTION DIFFUSION IMAGING TRACTOGRAPHY

Area of Science:

• Neuroimaging
• Diffusion MRI
• White Matter Tractography

Background:

• High angular resolution diffusion imaging (HARDI) provides in vivo analysis of white matter structure and connectivity.
• Orientation distribution functions (ODFs) from HARDI enable tractography to reconstruct axonal pathways.
• Multi-subject comparisons require consistent fiber bundle identification across individuals.

Purpose of the Study:

• To develop and validate a novel tractography method for population-based analysis of white matter pathways using HARDI data.
• To streamline statistical analysis of white matter integrity and connectivity in large cohorts.

Main Methods:

• Whole-brain tractography was performed on 20 young adults using HARDI at 4 T and a novel Hough transform method.
• Key pathways were selected by comparing reconstructed 3D curves to a probabilistic DTI atlas.
• Maximum density paths representing population tracts were derived using median filtering and graph search.

Main Results:

• The developed method effectively identified and represented major white matter tracts in a population cohort.
• Tract-based analysis of fractional anisotropy was performed, assessing the influence of the tractography algorithm.
• The method demonstrated potential for expediting population-based statistical analysis of HARDI and DTI data.

Conclusions:

• The novel tractography approach facilitates robust population-based statistical analysis of white matter structure from HARDI data.
• This method offers a streamlined way to compare white matter integrity and connectivity across subjects.
• The findings may advance our understanding of brain connectivity in health and disease through large-scale imaging studies.