Variability of gray and white matter during normal development: a voxel-based MRI analysis.

This study was aimed at investigating regional and local variability of brain tissue during normal human brain development. We investigated high-resolution MR-imaging data using SPM99 (Wellcome Department, University College London, UK). A pixel-wise variation coefficient of gray and white matter was calculated to visualize local variability. Data from 200 normal children (5-18 years) were analyzed. We found a profound interaction between variability of brain structures and normal development in both gray and white matter. Variability in gray and white matter shows regionally specific, age-related variations, possibly offering a new tool for the assessment of subtle brain abnormalities. Our results emphasize the necessity to take this variability into account when planning pediatric neuroimaging studies.