title: High-field magnetic resonance imaging of brain iron in Alzheimer disease.
abstract: OBJECTIVE
  Increased iron deposition in the brain may occur in several neurodegenerative diseases, including Alzheimer disease (AD). Iron deposits shorten T2 relaxation times on T2-weighted magnetic resonance (MR) images. Iron-dependent contrast increases with magnetic field strength. We hypothesized that T2 mapping using 3 T MR imaging (MRI) can disclose differences between normal controls and AD subjects.
  
  
  METHODS
  High-resolution brain imaging protocols were developed and applied to 24 AD patients and 20 age-matched controls using 3 T MRI. Eight anatomical regions of interest were manually segmented, and T2 histograms were computed. A visual analysis technique, the heat map, was modified and applied to the large image data sets generated by these protocols.
  
  
  RESULTS
  A large number (163) of features from these histograms were examined, and 38 of these were significantly different (P < 0.05) between the groups. In the hippocampus, evidence was found for AD-related increases in iron deposition (shortened T2) and in the concentration of free tissue water (lengthened T2). Imaging of a section of postmortem brain before and after chemically extracting the iron established the presence of MRI-detectable iron in the hippocampus, cortex, and white matter in addition to brain regions traditionally viewed as containing high iron concentrations.
authors.affiliation: General Electric Global Research Center, Schenectady, NY 12309, USA. schenck@research.ge.com
authors.forename: John F
authors.initials: JF
authors.lastname: Schenck
authors.forename: Earl A
authors.initials: EA
authors.lastname: Zimmerman
authors.forename: Zhu
authors.initials: Z
authors.lastname: Li
authors.forename: Sudeshna
authors.initials: S
authors.lastname: Adak
authors.forename: Angshuman
authors.initials: A
authors.lastname: Saha
authors.forename: Reeti
authors.initials: R
authors.lastname: Tandon
authors.forename: Kenneth M
authors.initials: KM
authors.lastname: Fish
authors.forename: Clifford
authors.initials: C
authors.lastname: Belden
authors.forename: Robert W
authors.initials: RW
authors.lastname: Gillen
authors.forename: Anne
authors.initials: A
authors.lastname: Barba
authors.forename: David L
authors.initials: DL
authors.lastname: Henderson
authors.forename: William
authors.initials: W
authors.lastname: Neil
authors.forename: Timothy
authors.initials: T
authors.lastname: O'Keefe
mesh_terms: D000368:Aged; D000544:Alzheimer Disease / Q000175:diagnosis* / Q000378:metabolism*; D015415:Biomarkers / Q000378:metabolism; D001921:Brain / Q000378:metabolism* / Q000473:pathology; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods; D007501:Iron / Q000378:metabolism*; D019189:Iron Metabolism Disorders / Q000175:diagnosis / Q000378:metabolism; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male
chemical_list: D015415:Biomarkers; D007501:Iron