Subject-specific analysis approach to longitudinal tracing of heterogeneous white matter abnormalities in sports-related concussion

Motivation: Unlike groupwise approaches, subject-specific analysis has the potential to pinpoint highly individualized abnormalities in white matter structure caused by sport-related concussion (SRC). Goal(s): Develop a subject-specific analysis approach to investigate the heterogeneity and longitudinal changes in white matter microstructures after SRC. Approach: The DTI metrics were voxel-by-voxel Z-transformed using a normal distributed template created from non-contact sport controls. The extreme Z maps were obtained, and averaged extreme Z-scores were compared across three study time points. Results: The existence of heterogeneity in the concussed brains can be appreciated in the projected extreme Z maps and their longitudinal trajectories. Impact: We developed a subject-specific analysis pipeline to demonstrate heterogeneity in sport-related concussion with respect to anatomical locations and recovery trajectories.