Short association fiber tractography: key insights and surprising facts

Abstract

Brain short association fibers (SAFs) significantly outnumber long fibers; however, these short connections have been less studied due to their small size, high inter-subject variability, and partial volume effects. Recent advancements in neuroimaging have made SAF tractography feasible through improvements in image quality and processing pipelines, though their tracking remains challenging, requiring specific tractography parameters and adapted pipelines for a reproducible reconstruction of superficial white matter (WM) bundles. Consequently, the segmentation and clustering of U-fibers within SAFs have proven feasible, providing new insights into the organization of cortical connectivity and enabling the study of SAFs in both healthy and pathological brains.

Keywords: Diffusion MRI; Short association fibers; Superficial white matter; Tractography.