title: Diffusion-tensor MR imaging of gray and white matter development during normal human brain maturation.
abstract: OBJECTIVE
  Conventional MR imaging findings of human brain development are thought to result from decreasing water content, increasing macromolecular concentration, and myelination. We use diffusion-tensor MR imaging to test theoretical models that incorporate hypotheses regarding how these maturational processes influence water diffusion in developing gray and white matter.
  
  
  METHODS
  Experimental data were derived from diffusion-tensor imaging of 167 participants, ages 31 gestational weeks to 11 postnatal years. An isotropic diffusion model was applied to the gray matter of the basal ganglia and thalamus. A model that assumes changes in the magnitude of diffusion while maintaining cylindrically symmetric anisotropy was applied to the white matter of the corpus callosum and internal capsule. Deviations of the diffusion tensor from the ideal model predictions, due to measurement noise, were estimated by using Monte Carlo simulations.
  
  
  RESULTS
  Developing gray matter of the basal ganglia and developing white matter of the internal capsule and corpus callosum largely conformed to theory, with only small departures from model predictions in older children. However, data from the thalamus substantially diverged from predicted values, with progressively larger deviations from the model with increasing participant age.
  
  
  CONCLUSIONS
  Changes in water diffusion during maturation of central gray and white matter structures can largely be explained by theoretical models incorporating simple assumptions regarding the influence of brain water content and myelination, although deviations from theory increase as the brain matures. Diffusion-tensor MR imaging is a powerful method for studying the process of brain development, with both scientific and clinical applications.
authors.affiliation: Mallinckrodt Institute of Radiology, St. Louis Children's Hospital, Washington University Medical Center, St. Louis, MO, USA.
authors.forename: Pratik
authors.initials: P
authors.lastname: Mukherjee
authors.forename: Jeffrey H
authors.initials: JH
authors.lastname: Miller
authors.forename: Joshua S
authors.initials: JS
authors.lastname: Shimony
authors.forename: Joseph V
authors.initials: JV
authors.lastname: Philip
authors.forename: Deepika
authors.initials: D
authors.lastname: Nehra
authors.forename: Abraham Z
authors.initials: AZ
authors.lastname: Snyder
authors.forename: Thomas E
authors.initials: TE
authors.lastname: Conturo
authors.forename: Jeffrey J
authors.initials: JJ
authors.lastname: Neil
authors.forename: Robert C
authors.initials: RC
authors.lastname: McKinstry
mesh_terms: D001479:Basal Ganglia / Q000033:anatomy & histology / Q000254:growth & development / Q000378:metabolism; D001834:Body Water / Q000378:metabolism; D001921:Brain / Q000033:anatomy & histology* / Q000254:growth & development / Q000378:metabolism; D002648:Child; D002675:Child, Preschool; D003198:Computer Simulation; D003337:Corpus Callosum / Q000033:anatomy & histology / Q000254:growth & development / Q000378:metabolism; D038524:Diffusion Magnetic Resonance Imaging; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D020772:Internal Capsule / Q000033:anatomy & histology / Q000254:growth & development / Q000378:metabolism; D013788:Thalamus / Q000033:anatomy & histology / Q000254:growth & development / Q000378:metabolism