title: White matter development during late adolescence in healthy males: a cross-sectional diffusion tensor imaging study.
abstract: BACKGROUND
  Previous MRI studies of healthy children have reported age-related white matter (WM) changes in language and motor areas of the brain. The authors investigated WM development in healthy adolescent males through age-associated changes in fractional anisotropy (FA), radial (lambda( perpendicular)) and axial (lambda(||)) diffusivity.
  
  
  METHODS
  Twenty-four healthy adolescent males (mean age=16.6, SD=2.5 years) were divided into two groups with an age split of 16.9 years and underwent a whole-brain voxelwise analysis.
  
  
  RESULTS
  At a threshold of p<0.001 and extent threshold of 100 contiguous voxels, several clusters with increased FA and axial diffusivity and no differences in radial diffusivity were observed in older adolescents compared to the younger adolescents in the left arcuate fasciculus, bilateral posterior internal capsule/thalamic radiation, bilateral prefrontal gyrus, right superior temporal gyrus, and posterior corpus callosum. Increased FA and lambda(||) of several clusters along the arcuate fasciculus significantly correlated with a test of language and semantic memory.
  
  
  CONCLUSIONS
  These results suggest ongoing maturational changes especially in the arcuate fasiculus during late adolescence. Increased FA and lambda(||) with no changes in radial diffusivity may reflect a developmental pattern of reduced tortuousity toward more straightened fibers and/or increased axonal fiber organization during late adolescence.
authors.affiliation: The Zucker-Hillside Hospital, Department of Psychiatry Research, 75-59 263rd Street, Glen Oaks, NY 11004, USA. manzar_ashtari@yahoo.com
authors.forename: Manzar
authors.initials: M
authors.lastname: Ashtari
authors.forename: Kelly L
authors.initials: KL
authors.lastname: Cervellione
authors.forename: Khader M
authors.initials: KM
authors.lastname: Hasan
authors.forename: Jinghui
authors.initials: J
authors.lastname: Wu
authors.forename: Carolyn
authors.initials: C
authors.lastname: McIlree
authors.forename: Hana
authors.initials: H
authors.lastname: Kester
authors.forename: Babak A
authors.initials: BA
authors.lastname: Ardekani
authors.forename: David
authors.initials: D
authors.lastname: Roofeh
authors.forename: Philip R
authors.initials: PR
authors.lastname: Szeszko
authors.forename: Sanjiv
authors.initials: S
authors.lastname: Kumra
mesh_terms: D000293:Adolescent; D000328:Adult; D001921:Brain / Q000033:anatomy & histology* / Q000254:growth & development*; D002648:Child; D038524:Diffusion Magnetic Resonance Imaging; D006801:Humans; D008297:Male; D012016:Reference Values