Development of white matter fibre density and morphology over childhood: A longitudinal fixel-based analysis

Abstract

Purpose: White matter fibre development in childhood involves dynamic changes to microstructural organisation driven by increasing axon diameter, density, and myelination. However, there is a lack of longitudinal studies that have quantified advanced diffusion metrics to identify regions of accelerated fibre maturation, particularly across the early pubertal period. We applied a novel longitudinal fixel-based analysis (FBA) framework, in order to estimate microscopic and macroscopic white matter changes over time. Methods: Diffusion-weighted imaging (DWI) data were acquired for 59 typically developing children (27 female) aged 9–13 years at two time-points approximately 16 months apart (time..