title: Cross-validation of brain structural biomarkers and cognitive aging in a community-based study.
abstract: BACKGROUND
  Population-based studies face challenges in measuring brain structure relative to cognitive aging. We examined the feasibility of acquiring state-of-the-art brain MRI images at a community hospital, and attempted to cross-validate two independent approaches to image analysis.
  
  
  METHODS
  Participants were 49 older adults (29 cognitively normal and 20 with mild cognitive impairment (MCI)) drawn from an ongoing cohort study, with annual clinical assessments within one month of scan, without overt cerebrovascular disease, and without dementia (Clinical Dementia Rating (CDR) < 1). Brain MRI images, acquired at the local hospital using the Alzheimer's Disease Neuroimaging Initiative protocol, were analyzed using (1) a visual atrophy rating scale and (2) a semi-automated voxel-level morphometric method. Atrophy and volume measures were examined in relation to cognitive classification (any MCI and amnestic MCI vs. normal cognition), CDR (0.5 vs. 0), and presumed etiology.
  
  
  RESULTS
  Measures indicating greater atrophy or lesser volume of the hippocampal formation, the medial temporal lobe, and the dilation of the ventricular space were significantly associated with cognitive classification, CDR = 0.5, and presumed neurodegenerative etiology, independent of the image analytic method. Statistically significant correlations were also found between the visual ratings of medial temporal lobe atrophy and the semi-automated ratings of brain structural integrity.
  
  
  CONCLUSIONS
  High quality MRI data can be acquired and analyzed from older adults in population studies, enhancing their capacity to examine imaging biomarkers in relation to cognitive aging and dementia.
authors.affiliation: Department of Psychiatry, University of Pittsburgh, Pittsburgh, PA, USA. BeckerJT@upmc.edu
authors.forename: James T
authors.initials: JT
authors.lastname: Becker
authors.forename: Ranjan
authors.initials: R
authors.lastname: Duara
authors.forename: Ching-Wen
authors.initials: CW
authors.lastname: Lee
authors.forename: Leonid
authors.initials: L
authors.lastname: Teverovsky
authors.forename: Beth E
authors.initials: BE
authors.lastname: Snitz
authors.forename: Chung-Chou H
authors.initials: CC
authors.lastname: Chang
authors.forename: Mary
authors.initials: M
authors.lastname: Ganguli
mesh_terms: D000375:Aging / Q000473:pathology; D015415:Biomarkers; D001921:Brain / Q000473:pathology* / Q000503:physiopathology; D016022:Case-Control Studies; D060825:Cognitive Dysfunction / Q000473:pathology* / Q000503:physiopathology; D005260:Female; D006624:Hippocampus / Q000473:pathology; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D059906:Neuroimaging; D009483:Neuropsychological Tests; D015203:Reproducibility of Results; D013702:Temporal Lobe / Q000473:pathology
chemical_list: D015415:Biomarkers