title: In vivo assessment of age-related brain iron differences by magnetic field correlation imaging.
abstract: OBJECTIVE
  To assess a recently developed magnetic resonance imaging (MRI) technique called magnetic field correlation (MFC) imaging along with a conventional imaging method, the transverse relaxation rate (R2), for estimating age-related brain iron concentration in adolescents and adults. Brain region measures were compared with nonheme iron concentrations (C(PM) ) based on a prior postmortem study.
  
  
  METHODS
  Asymmetric spin echo (ASE) images were acquired at 3T from 26 healthy individuals (16 adolescents, 10 adults). Regions of interest (ROIs) were placed in areas in which age-related iron content was estimated postmortem: globus pallidus (GP), putamen (PUT), caudate nucleus (CN), thalamus (THL), and frontal white matter (FWM). Regression and group analyses were conducted on ROI means.
  
  
  RESULTS
  MFC and R2 displayed significant linear relationships to C(PM) when all regions were combined. Whereas MFC was significantly correlated with C(PM) for every individual region except FWM and detected significantly lower means in adolescents than adults for each region, R2 detected significant correlation and lower means for only PUT and CN.
  
  
  CONCLUSIONS
  Our results support the hypothesis that MFC is sensitive to brain iron in GM regions and detects age-related iron increases known to occur from adolescence to adulthood. MFC may be more sensitive than R2 to iron-related changes occurring within specific brain regions.
authors.affiliation: Center for Biomedical Imaging, Department of Radiology, New York University School of Medicine, New York, NY, USA. va415@med.nyu.edu
authors.forename: Vitria
authors.initials: V
authors.lastname: Adisetiyo
authors.forename: Jens H
authors.initials: JH
authors.lastname: Jensen
authors.forename: Anita
authors.initials: A
authors.lastname: Ramani
authors.forename: Ali
authors.initials: A
authors.lastname: Tabesh
authors.forename: Adriana
authors.initials: A
authors.lastname: Di Martino
authors.forename: Els
authors.initials: E
authors.lastname: Fieremans
authors.forename: Francisco X
authors.initials: FX
authors.lastname: Castellanos
authors.forename: Joseph A
authors.initials: JA
authors.lastname: Helpern
mesh_terms: D000293:Adolescent; D000328:Adult; D000375:Aging / Q000378:metabolism*; D000465:Algorithms; D001921:Brain / Q000033:anatomy & histology / Q000378:metabolism*; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D007501:Iron / Q000378:metabolism*; D060526:Magnetic Fields; D008279:Magnetic Resonance Imaging / Q000379:methods*; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008297:Male; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013223:Statistics as Topic; D014018:Tissue Distribution; D055815:Young Adult
chemical_list: D007501:Iron