Magnitude and timing of major white matter tract maturation from infancy through adolescence with NODDI

• Published in: NeuroImage (Orlando, Fla.) Vol. 212; p. 116672
• Main Authors: Lynch, Kirsten M., Cabeen, Ryan P., Toga, Arthur W., Clark, Kristi A.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 15.05.2020; Elsevier Limited; Elsevier
• Subjects: Adolescence; Adolescent; Adolescents; Age; Brain - growth & development; Brain development; Child; Child development; Child, Preschool; Cross-Sectional Studies; Diffusion MRI; Female; Fibers; Humans; Image Processing, Computer-Assisted; Infant; Magnetic Resonance Imaging; Male; Maturation; Microstructure; Myelination; Neural Pathways - growth & development; Neurites; Neurogenesis; Neuroimaging - methods; NODDI; Studies; Substantia alba; Teenagers; White matter; White Matter - growth & development; NODDI; Diffusion MRI; Maturation; Microstructure; White matter; Brain development
• ISSN: 1053-8119; 1095-9572; 1095-9572
• DOI: 10.1016/j.neuroimage.2020.116672

White matter maturation is a nonlinear and heterogeneous phenomenon characterized by axonal packing, increased axon caliber, and a prolonged period of myelination. While current in vivo diffusion MRI (dMRI) methods, like diffusion tensor imaging (DTI), have successfully characterized the gross structure of major white matter tracts, these measures lack the specificity required to unravel the distinct processes that contribute to microstructural development. Neurite orientation dispersion and density imaging (NODDI) is a dMRI approach that probes tissue compartments and provides biologically meaningful measures that quantify neurite density index (NDI) and orientation dispersion index (ODI). The purpose of this study was to characterize the magnitude and timing of major white matter tract maturation with NODDI from infancy through adolescence in a cross-sectional cohort of 104 subjects (0.6–18.8 years). To probe the regional nature of white matter development, we use an along-tract approach that partitions tracts to enable more fine-grained analysis. Major white matter tracts showed exponential age-related changes in NDI with distinct maturational patterns. Overall, analyses revealed callosal fibers developed before association fibers. Our along-tract analyses elucidate spatially varying patterns of maturation with NDI that are distinct from those obtained with DTI. ODI was not significantly associated with age in the majority of tracts. Our results support the conclusion that white matter tract maturation is heterochronous process and, furthermore, we demonstrate regional variability in the developmental timing within major white matter tracts. Together, these results help to disentangle the distinct processes that contribute to and more specifically define the time course of white matter maturation. •Neurite density index increases nonlinearly with age in major white matter tracts.•Callosal fibers develop earlier than association fibers using neurite density index.•Neurite density index rate of change varies along the length of tracts.•Orientation dispersion index is not related to age in the majority of tracts.