title: Correlation of white matter diffusivity and anisotropy with age during childhood and adolescence: a cross-sectional diffusion-tensor MR imaging study.
abstract: OBJECTIVE
  To evaluate differences in white matter diffusion properties as a function of age in healthy children and adolescents.
  
  
  METHODS
  Echo-planar diffusion-tensor magnetic resonance (MR) imaging was performed in 33 healthy subjects aged 5-18 years who were recruited from a functional imaging study of normal language development. Results of neurologic, psychologic, and structural MR imaging examinations were within the normal range for all subjects. The trace of the apparent diffusion coefficient and fractional anisotropy in white matter were correlated as a function of age by using Spearman rank correlation.
  
  
  RESULTS
  Statistically significant negative correlation of the trace of the apparent diffusion coefficient with age was found throughout the white matter. Significant positive correlation of fractional anisotropy with age was found in the internal capsule, corticospinal tract, left arcuate fasciculus, and right inferior longitudinal fasciculus.
  
  
  CONCLUSIONS
  Diffusion-tensor MR imaging results indicate that white matter maturation assessed at different ages involves increases in both white matter density and organization during childhood and adolescence. The trace of the apparent diffusion coefficient and fractional anisotropy may reflect different physiologic processes in healthy children and adolescents.
authors.affiliation: Imaging Research Center, Children's Hospital Medical Center, 3333 Burnet Ave, Suite R050A, Cincinnati, OH 45229, USA. vince@athena.chmcc.org
authors.forename: Vincent J
authors.initials: VJ
authors.lastname: Schmithorst
authors.forename: Marko
authors.initials: M
authors.lastname: Wilke
authors.forename: Bernard J
authors.initials: BJ
authors.lastname: Dardzinski
authors.forename: Scott K
authors.initials: SK
authors.lastname: Holland
mesh_terms: D000293:Adolescent; D000367:Age Factors; D016880:Anisotropy; D001921:Brain / Q000033:anatomy & histology* / Q000254:growth & development*; D002648:Child; D002675:Child, Preschool; D004058:Diffusion; D017352:Echo-Planar Imaging / Q000379:methods*; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008297:Male