title: Do brain image databanks support understanding of normal ageing brain structure? A systematic review.
abstract: OBJECTIVE
  To document accessible magnetic resonance (MR) brain images, metadata and statistical results from normal older subjects that may be used to improve diagnoses of dementia.
  
  
  METHODS
  We systematically reviewed published brain image databanks (print literature and Internet) concerned with normal ageing brain structure.
  
  
  RESULTS
  From nine eligible databanks, there appeared to be 944 normal subjects aged ≥60 years. However, many subjects were in more than one databank and not all were fully representative of normal ageing clinical characteristics. Therefore, there were approximately 343 subjects aged ≥60 years with metadata representative of normal ageing, but only 98 subjects were openly accessible. No databank had the range of MR image sequences, e.g. T2*, fluid-attenuated inversion recovery (FLAIR), required to effectively characterise the features of brain ageing. No databank supported random subject retrieval; therefore, manual selection bias and errors may occur in studies that use these subjects as controls. Finally, no databank stored results from statistical analyses of its brain image and metadata that may be validated with analyses of further data.
  
  
  CONCLUSIONS
  Brain image databanks require open access, more subjects, metadata, MR image sequences, searchability and statistical results to improve understanding of normal ageing brain structure and diagnoses of dementia.
  
  
  CONCLUSIONS
  • We reviewed databanks with structural MR brain images of normal older people. • Among these nine databanks, 98 normal subjects ≥60 years were openly accessible. • None had all the required sequences, random subject retrieval or statistical results. • More access, subjects, sequences, metadata, searchability and results are needed. • These may improve understanding of normal brain ageing and diagnoses of dementia.
authors.affiliation: Division of Clinical Neurosciences, Western General Hospital, Brain Research Imaging Centre (BRIC), University of Edinburgh, Crewe Road, Edinburgh, EH4 2XU, UK. d.a.dickie@sms.ed.ac.uk
authors.forename: David Alexander
authors.initials: DA
authors.lastname: Dickie
authors.forename: Dominic E
authors.initials: DE
authors.lastname: Job
authors.forename: Ian
authors.initials: I
authors.lastname: Poole
authors.forename: Trevor S
authors.initials: TS
authors.lastname: Ahearn
authors.forename: Roger T
authors.initials: RT
authors.lastname: Staff
authors.forename: Alison D
authors.initials: AD
authors.lastname: Murray
authors.forename: Joanna M
authors.initials: JM
authors.lastname: Wardlaw
mesh_terms: D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000473:pathology* / Q000502:physiology*; D001921:Brain / Q000033:anatomy & histology* / Q000254:growth & development*; D002648:Child; D002675:Child, Preschool; D016208:Databases, Factual / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008279:Magnetic Resonance Imaging / Q000706:statistics & numerical data*; D008297:Male; D008875:Middle Aged; D011873:Radiology Information Systems / Q000706:statistics & numerical data*; D012016:Reference Values; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D055815:Young Adult