title: Using functional Magnetic Resonance Imaging to differentiate between healthy aging subjects, Mild Cognitive Impairment, and Alzheimer's patients.
abstract: BACKGROUND
  Alzheimer's disease is the most common form of dementia which is still difficult to be differentiated from other types of brain disorders. Moreover, Mild Cognitive Impairment refers to the presence of cognitive impairments that is not severe enough to meet the criteria of Alzheimer's, and its diagnosis in early stages is so critical. There is currently no distinct method available for diagnosing Alzheimer's or Mild Cognitive Impairment, and their diagnosis needs a combination of different methods and assessments.
  
  
  METHODS
  The aim of this study was to evaluate the effectiveness of functional Magnetic Resonance Imaging (fMRI) in differentiating between Alzheimer's, Mild Cognitive Impairment (MCI) and healthy aging. To prove fMRI's ability, resting-state brain activation patterns between these three groups of subjects were compared using Independent Component Analysis (ICA) algorithm. Forty age- and sex-matched subjects, 15 elderly, 11 MCI and 14 Alzheimer's subjects were examined.
  
  
  RESULTS
  The results showed that during a certain resting-state session, healthy aging brain benefits from larger area and greater intensity of activation (compared with MCI and Alzheimer's group) in Posterior Cingulate Cortex (PCC) region of the brain, as part of Default Mode Network.
  
  
  CONCLUSIONS
  This difference in activation pattern can be used as a diagnostic criterion in using fMRI for differentiating between Alzheimer's Disease (AD), MCI and healthy aging.
authors.affiliation: Medical Physics and Biomedical Engineering Department, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Mohammad Ali
authors.initials: MA
authors.lastname: Oghabian
authors.forename: Seyed Amir Hossein
authors.initials: SA
authors.lastname: Batouli
authors.forename: Maryam
authors.initials: M
authors.lastname: Norouzian
authors.forename: Maryam
authors.initials: M
authors.lastname: Ziaei
authors.forename: Hajir
authors.initials: H
authors.lastname: Sikaroodi