Highly replicable multisite patterns of adolescent white matter maturation.

Adolescent brain development is difficult to study at scale because diffusion MRI (dMRI) measures are sensitive to technical variability across scanning environments. The Adolescent Brain Cognitive Development (ABCD) study is the largest US-based longitudinal neuroimaging study of adolescent brain maturation. We present ABCD-Brain Imaging Data Structure (BIDS) Community Collection (ABCC) release 3.1.0, a curated resource of more than 24,000 fully processed human ABCD dMRI datasets from participants aged 8-17 years. ABCC provides processed images, nuanced image quality metrics, advanced microstructural measures, and person-specific white matter bundle tractography. Across 62 bundles, measures of diffusion restriction and non-Gaussianity-including intracellular volume fraction from neurite orientation dispersion and density imaging (NODDI), mean kurtosis tensor from diffusion kurtosis imaging (DKI), and return-to-origin probability from mean apparent propagator (MAP)-MRI-were more sensitive to development and more robust to variation in image quality than tensor-derived measures. Longitudinal harmonization of microstructural features with ComBat-GAMM markedly improved the cross-vendor generalizability of developmental effects. Together, ABCC accelerates reproducible, rigorous research on adolescent white matter development.