title: Changes in brain water diffusion during the 1st year of life.
abstract: OBJECTIVE
  To evaluate the normal water diffusion changes that occur during the 1st year of life.
  
  
  METHODS
  Diffusion-weighted imaging was performed in 40 subjects (age range, birth to 1 year) in whom both magnetic resonance imaging and neurologic assessment results were normal at the time of imaging and, where available, at follow-up. Apparent diffusion coefficient (ADC) was calculated in four areas of white matter (anterior and posterior subcortical and internal capsule) and four of gray matter (cortex, thalamus, head of the caudate nucleus, and lentiform nucleus). Linear regression was used to examine the effect of age on ADC, and analysis of variance was used to compare ADC within different brain regions.
  
  
  RESULTS
  ADC decreased with age in all regions (P <.01). Data best fit with a logarithmic decline (r(2) = 0.20-0.63). ADC was significantly higher in white (113 x 10(-5) mm(2)/sec) than in gray matter (102 x 10(-5) mm(2)/sec; P <.001). Significant differences were seen among three white matter regions (subcortical, 188 x 10(-5) mm(2)/sec at birth; anterior limb of internal capsule, 130 x 10(-5) mm(2)/sec; posterior limb of internal capsule, 109 x 10(-5) mm(2)/sec) and three gray matter regions (cortex, 134 x 10(-5) mm(2)/sec at birth; head of caudate nucleus, 134 x 10(-5) mm(2)/sec at birth; and thalamus and lentiform nucleus, 120 x 10(-5) mm(2)/sec; P <.01).
  
  
  CONCLUSIONS
  Results suggest that in neonates and infants, water diffusion is highly dependent on both subject age and brain location.
authors.affiliation: Division of Neuroradiology, Barrow Neurological Institute, St Joseph's Hospital and Medical Center, 350 W Thomas Rd, Phoenix, AZ 85013, USA. kforbes@chw.edu
authors.forename: Kirsten P N
authors.initials: KP
authors.lastname: Forbes
authors.forename: James G
authors.initials: JG
authors.lastname: Pipe
authors.forename: C Roger
authors.initials: CR
authors.lastname: Bird
mesh_terms: D000367:Age Factors; D001921:Brain / Q000378:metabolism*; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D014867:Water / Q000378:metabolism*
chemical_list: D014867:Water