Normal development of human brain white matter from infancy to early adulthood: a diffusion tensor imaging study

Area of Science:

• Neuroimaging
• Developmental Neuroscience
• Biomedical Engineering

Background:

• Diffusion Tensor Imaging (DTI) visualizes neural tracts by measuring water diffusion anisotropy in white matter.
• Understanding white matter development is crucial for characterizing normal brain maturation.
• Previous studies have explored DTI parameters, but comprehensive developmental trajectories across a wide age range are needed.

Purpose of the Study:

• To investigate developmental changes in white matter microstructure from infancy to early adulthood using DTI.
• To examine sex and hemispheric differences in neural fiber development.
• To quantify DTI parameters (FA, ADC, AD, RD) in specific tracts of interest (TOIs).

Main Methods:

• DTI was performed on 52 healthy subjects aged 2 months to 25 years.
• Regions of interest were defined for the corpus callosum (CC), cingulum hippocampus (CGH), inferior longitudinal fasciculus (ILF), and superior longitudinal fasciculus (SLF).
• Fractional anisotropy (FA), apparent diffusion coefficient (ADC), axial diffusivity (AD), and radial diffusivity (RD) were measured and analyzed using locally weighted scatterplot smoothing (LOESS).

Main Results:

• FA increased with age, while ADC, AD, and RD decreased across all TOIs, with a growth rate turning point around 6 years.
• The corpus callosum (CC) showed higher FA than other tracts; its splenium (sCC) had higher FA, ADC, and AD, but lower RD than the genu (gCC).
• Right-hemisphere tracts exhibited significantly greater FA than left-hemisphere tracts; infants showed higher FA and RD growth rates than AD.

Conclusions:

• White matter development is characterized by increasing FA and decreasing RD, reflecting myelination and microstructural maturation.
• Developmental patterns vary significantly across different white matter tracts and hemispheres.
• These findings provide a detailed characterization of normal white matter development from infancy to early adulthood.