title: A longitudinal study of brain volume changes in normal aging using serial registered magnetic resonance imaging.
abstract: OBJECTIVE
  To investigate the effect of age on global and regional brain volumes and rates of atrophy, and to compare directly results based on cross-sectional and longitudinal data.
  
  
  METHODS
  Thirty-nine healthy control subjects (age range, 31-84 years) underwent serial magnetic resonance imaging assessments. Measurements included the whole-brain, temporal lobe, hippocampal, and ventricular volumes at baseline and for repeat scans.
  
  
  RESULTS
  We found significant decreases in cross-sectional whole-brain (P<.001), temporal lobe (P<.001), and hippocampal (P =.003) volumes and a significant increase in ventricular volume (P<.001) with increasing age. Cross-sectional and longitudinal estimates of atrophy rates were similar. We also found directional evidence of acceleration in atrophy rates with increasing age in all analyses, with the most marked changes occurring after 70 years of age. This increase in rates after 70 years of age was particularly marked in the ventricles (P<.001) and the hippocampi (P =.01).
  
  
  CONCLUSIONS
  We found a significant age-associated decrease in global and regional brain volumes. Some evidence indicates that this decline in brain volumes may be due to a nonlinear acceleration in rates of atrophy with increasing age. A better understanding of this process may help to discriminate normal age-related changes from neurodegenerative diseases.
authors.affiliation: Dementia Research Group, Department of Clinical Neurology, Institute of Neurology, University College London, England. rscahill@dementia.ion.ucl.ac.uk
authors.forename: Rachael I
authors.initials: RI
authors.lastname: Scahill
authors.forename: Chris
authors.initials: C
authors.lastname: Frost
authors.forename: Rhian
authors.initials: R
authors.lastname: Jenkins
authors.forename: Jennifer L
authors.initials: JL
authors.lastname: Whitwell
authors.forename: Martin N
authors.initials: MN
authors.lastname: Rossor
authors.forename: Nick C
authors.initials: NC
authors.lastname: Fox
mesh_terms: D000328:Adult; D000368:Aged; D000375:Aging; D001284:Atrophy; D001921:Brain / Q000033:anatomy & histology* / Q000000981:diagnostic imaging / Q000473:pathology; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008137:Longitudinal Studies; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D011859:Radiography; D012737:Sex Factors