Diffusion-tensor MR imaging of gray and white matter development during normal human brain maturation.

Area of Science:

• Neuroimaging
• Developmental Neuroscience
• Biophysics

Background:

• Human brain development involves decreasing water content, increasing macromolecular concentration, and myelination.
• These changes are hypothesized to influence water diffusion in developing brain tissues.

Purpose of the Study:

• To test theoretical models of brain maturation using diffusion-tensor MR imaging.
• To investigate how maturational processes affect water diffusion in developing gray and white matter.

Main Methods:

• Diffusion-tensor imaging (DTI) was performed on 167 participants (31 gestational weeks to 11 postnatal years).
• Specific diffusion models were applied to gray matter (basal ganglia, thalamus) and white matter (corpus callosum, internal capsule).
• Monte Carlo simulations estimated deviations from model predictions due to measurement noise.

Main Results:

• Gray matter (basal ganglia) and white matter (corpus callosum, internal capsule) generally followed theoretical predictions.
• The thalamus showed significant and increasing deviations from theoretical models with advancing age.
• Small departures from model predictions were observed in older children for other regions.

Conclusions:

• Theoretical models incorporating water content and myelination explain water diffusion changes during central gray and white matter maturation.
• Increasing deviations from theory in the thalamus suggest complex developmental processes.
• Diffusion-tensor MR imaging is a valuable tool for studying brain development with scientific and clinical potential.