title: Normal brain development and aging: quantitative analysis at in vivo MR imaging in healthy volunteers.
abstract: OBJECTIVE
  To quantitate neuroanatomic parameters in healthy volunteers and to compare the values with normative values from postmortem studies.
  
  
  METHODS
  Magnetic resonance (MR) images of 116 volunteers aged 19 months to 80 years were analyzed with semiautomated procedures validated by means of comparison with manual tracings. Volumes measured included intracranial space, whole brain, gray matter (GM), white matter (WM), and cerebrospinal fluid (CSF). Results were compared with values from previous postmortem studies.
  
  
  RESULTS
  Whole brain and intracranial space grew by 25%-27% between early childhood (mean age, 26 months; age range, 19-33 months) and adolescence (mean age, 14 years; age range, 12-15 years); thereafter, whole-brain volume decreased such that volunteers (age range, 71-80 years) had volumes similar to those of young children. GM increased 13% from early to later (6-9 years) childhood. Thereafter, GM increased more slowly and reached a plateau in the 4th decade; it decreased by 13% in the oldest volunteers. The GM-WM ratio decreased exponentially from early childhood through the 4th decade; thereafter, it gradually declined. In vivo patterns of change in the intracranial space, whole brain, and GM-WM ratio agreed with published postmortem data.
  
  
  CONCLUSIONS
  MR images accurately depict normal patterns of age-related change in intracranial space, whole brain, GM, WM, and CSF. These quantitative MR imaging data can be used in research studies and clinical settings for the detection of abnormalities in fundamental neuroanatomic parameters.
authors.affiliation: Laboratory for Research on the Neuroscience of Autism, Children's Hospital Research Center, La Jolla, CA 92037, USA. ecourchesne@ucsd.edu
authors.forename: E
authors.initials: E
authors.lastname: Courchesne
authors.forename: H J
authors.initials: HJ
authors.lastname: Chisum
authors.forename: J
authors.initials: J
authors.lastname: Townsend
authors.forename: A
authors.initials: A
authors.lastname: Cowles
authors.forename: J
authors.initials: J
authors.lastname: Covington
authors.forename: B
authors.initials: B
authors.lastname: Egaas
authors.forename: M
authors.initials: M
authors.lastname: Harwood
authors.forename: S
authors.initials: S
authors.lastname: Hinds
authors.forename: G A
authors.initials: GA
authors.lastname: Press
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000502:physiology*; D001921:Brain / Q000033:anatomy & histology*; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007223:Infant; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D012016:Reference Values