title: Evaluation of brain ageing: a quantitative longitudinal MRI study over 7 years.
abstract: OBJECTIVE
  T1 relaxometry is a promising tool for the assessment of microstructural changes during brain ageing. Previous cross-sectional studies demonstrated increasing T1 values in white and decreasing T1 values in grey matter over the lifetime. However, these findings have not yet been confirmed on the basis of a longitudinal study. In this longitudinal study over 7 years, T1 relaxometry was used to investigate the dynamics of age-related microstructural changes in older healthy subjects.
  
  
  METHODS
  T1 mapping was performed in 17 healthy subjects (range 51-77 years) at baseline and after 7 years. Advanced cortical and white matter segmentation was used to determine mean T1 values in the cortex and white matter.
  
  
  RESULTS
  The analysis revealed a decrease of mean cortical T1 values over 7 years, the rate of T1 reduction being more prominent in subjects with higher age. T1 decreases were predominantly localized in the lateral frontal, parietal and temporal cortex. In contrast, mean white matter T1 values remained stable.
  
  
  CONCLUSIONS
  T1 mapping is shown to be sensitive to age-related microstructural changes in healthy ageing subjects in a longitudinal setting. Data of a cohort in late adulthood and the senescence period demonstrate a decrease of cortical T1 values over 7 years, most likely reflecting decreasing water content and increased iron concentrations.
  
  
  CONCLUSIONS
  • T1 mapping is sensitive to age-related microstructural changes in a longitudinal setting. • T1 decreases were predominantly localized in the lateral frontal, parietal and temporal cortex. • The rate of T1 reduction was more prominent in subjects with higher age. • These changes most likely reflect decreasing cortical water and increasing iron concentrations.
authors.affiliation: Department of Neurology, Goethe University, Frankfurt/Main, Germany. Rene-Maxime.Gracien@kgu.de.|Brain Imaging Center, Goethe University, Frankfurt/Main, Germany. Rene-Maxime.Gracien@kgu.de.
authors.forename: René-Maxime
authors.initials: RM
authors.lastname: Gracien
authors.affiliation: Department of Neurology, Goethe University, Frankfurt/Main, Germany.|Brain Imaging Center, Goethe University, Frankfurt/Main, Germany.
authors.forename: Lucas
authors.initials: L
authors.lastname: Nürnberger
authors.affiliation: Department of Neurology, Goethe University, Frankfurt/Main, Germany.|Brain Imaging Center, Goethe University, Frankfurt/Main, Germany.|Department of Neurology, Palacky University, Olomouc, Czech Republic.
authors.forename: Pavel
authors.initials: P
authors.lastname: Hok
authors.affiliation: Department of Neurology, Goethe University, Frankfurt/Main, Germany.|Brain Imaging Center, Goethe University, Frankfurt/Main, Germany.
authors.forename: Stephanie-Michelle
authors.initials: SM
authors.lastname: Hof
authors.affiliation: Department of Neurology, Goethe University, Frankfurt/Main, Germany.|Brain Imaging Center, Goethe University, Frankfurt/Main, Germany.
authors.forename: Sarah C
authors.initials: SC
authors.lastname: Reitz
authors.affiliation: Dr. Senckenberg Chronomedical Institute, Goethe University, Frankfurt/Main, Germany.
authors.forename: Udo
authors.initials: U
authors.lastname: Rüb
authors.affiliation: Department of Neurology, Goethe University, Frankfurt/Main, Germany.
authors.forename: Helmuth
authors.initials: H
authors.lastname: Steinmetz
authors.affiliation: Department of Neurology, Goethe University, Frankfurt/Main, Germany.|Brain Imaging Center, Goethe University, Frankfurt/Main, Germany.
authors.forename: Rüdiger
authors.initials: R
authors.lastname: Hilker-Roggendorf
authors.affiliation: Department of Neurology, Goethe University, Frankfurt/Main, Germany.|Brain Imaging Center, Goethe University, Frankfurt/Main, Germany.|Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK.
authors.forename: Johannes C
authors.initials: JC
authors.lastname: Klein
authors.affiliation: Brain Imaging Center, Goethe University, Frankfurt/Main, Germany.
authors.forename: Ralf
authors.initials: R
authors.lastname: Deichmann
authors.affiliation: Department of Neurology, Goethe University, Frankfurt/Main, Germany.|Brain Imaging Center, Goethe University, Frankfurt/Main, Germany.
authors.forename: Simon
authors.initials: S
authors.lastname: Baudrexel
mesh_terms: D000368:Aged; D000375:Aging / Q000473:pathology / Q000502:physiology*; D001921:Brain / Q000000981:diagnostic imaging* / Q000473:pathology*; D001931:Brain Mapping / Q000379:methods*; D003430:Cross-Sectional Studies; D005069:Evaluation Studies as Topic; D005260:Female; D005500:Follow-Up Studies; D066128:Gray Matter / Q000000981:diagnostic imaging / Q000473:pathology; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D007501:Iron / Q000032:analysis; D008137:Longitudinal Studies; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D013702:Temporal Lobe / Q000000981:diagnostic imaging / Q000473:pathology; D066127:White Matter / Q000000981:diagnostic imaging / Q000473:pathology
chemical_list: D007501:Iron
keywords: Ageing; Cerebral cortex; Quantitative magnetic resonance imaging; T1 relaxation; White matter