title: Identifying cognitively healthy elderly individuals with subsequent memory decline by using automated MR temporoparietal volumes.
abstract: OBJECTIVE
  To determine whether automated temporoparietal brain volumes can be used to accurately predict future memory decline among a multicenter cohort of cognitively healthy elderly individuals.
  
  
  METHODS
  The study was approved by the institutional review board at each site and was HIPAA compliant, with written consent obtained from all participants. One hundred forty-nine cognitively healthy study participants were recruited through the Alzheimer's Disease Neuroimaging Initiative and underwent a standardized baseline 1.5-T magnetic resonance (MR) imaging examination, as well as neuropsychological assessment at baseline and after 2 years of follow-up. A composite memory score for the 2-year change in the results of two delayed-recall tests was calculated, and memory decline was defined as a composite score that was at least 1 standard deviation below the group mean score. The predictive accuracy of the brain volumes was estimated by using areas under receiver operating characteristic curves and was further assessed by using leave-one-out cross validation.
  
  
  RESULTS
  Use of the most accurate region model, which included the hippocampus; parahippocampal gyrus; amygdala; superior, middle, and inferior temporal gyri; superior parietal lobe; and posterior cingulate gyrus, resulted in a fitted accuracy of 94% and a cross-validated accuracy of 81%.
  
  
  CONCLUSIONS
  Study results indicate that automated temporal and parietal volumes can be used to identify with high accuracy cognitively healthy individuals who are at risk for future memory decline. Further validation of this predictive model in a new cohort is required.
authors.affiliation: Department of Radiology, University of California, San Francisco, 505 Parnassus Ave, Room M391, San Francisco, CA, 94143, USA. gloria.chiang@ucsf.edu
authors.forename: Gloria C
authors.initials: GC
authors.lastname: Chiang
authors.forename: Philip S
authors.initials: PS
authors.lastname: Insel
authors.forename: Duygu
authors.initials: D
authors.lastname: Tosun
authors.forename: Norbert
authors.initials: N
authors.lastname: Schuff
authors.forename: Diana
authors.initials: D
authors.lastname: Truran-Sacrey
authors.forename: Sky
authors.initials: S
authors.lastname: Raptentsetsang
authors.forename: Clifford R
authors.initials: CR
authors.lastname: Jack
authors.forename: Michael W
authors.initials: MW
authors.lastname: Weiner
mesh_terms: D000368:Aged; D000544:Alzheimer Disease / Q000175:diagnosis* / Q000473:pathology; D002170:Canada; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008569:Memory Disorders / Q000175:diagnosis* / Q000473:pathology; D009483:Neuropsychological Tests; D010296:Parietal Lobe / Q000473:pathology*; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012372:ROC Curve; D013702:Temporal Lobe / Q000473:pathology*; D014481:United States