title: Correlating brain blood oxygenation level dependent (BOLD) fractal dimension mapping with magnetic resonance spectroscopy (MRS) in Alzheimer's disease.
abstract: OBJECTIVE
  To correlate temporal fractal structure of resting state blood oxygen level dependent (rsBOLD) functional magnetic resonance imaging (fMRI) with in vivo proton magnetic resonance spectroscopy ((1)H-MRS), in Alzheimer's disease (AD) and healthy age-matched normal controls (NC).
  
  
  METHODS
  High temporal resolution (4 Hz) rsBOLD signal and single voxel (left putamen) magnetic resonance spectroscopy data was acquired in 33 AD patients and 13 NC. The rsBOLD data was analyzed using two types of fractal dimension (FD) analysis based on relative dispersion and frequency power spectrum. Comparisons in FD were performed between AD and NC, and FD measures were correlated with (1)H-MRS findings.
  
  
  RESULTS
  Temporal fractal analysis of rsBOLD, was able to differentiate AD from NC subjects (P = 0.03). Low FD correlated with markers of AD severity including decreased concentrations of N-acetyl aspartate (R = 0.44, P = 0.015) and increased myoinositol (mI) (R = -0.45, P = 0.012).
  
  
  CONCLUSIONS
  Based on these results we suggest fractal analysis of rsBOLD could provide an early marker of AD.
authors.affiliation: School of Biomedical Engineering, McMaster University, Hamilton, ON, Canada.
authors.forename: Mohammed A
authors.initials: MA
authors.lastname: Warsi
authors.forename: William
authors.initials: W
authors.lastname: Molloy
authors.forename: Michael D
authors.initials: MD
authors.lastname: Noseworthy
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000465:Algorithms; D000544:Alzheimer Disease / Q000097:blood* / Q000378:metabolism*; D001921:Brain / Q000473:pathology*; D001931:Brain Mapping / Q000379:methods*; D016022:Case-Control Studies; D005260:Female; D017709:Fractals; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D008279:Magnetic Resonance Imaging / Q000379:methods; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008297:Male; D015233:Models, Statistical; D010100:Oxygen / Q000378:metabolism*; D013997:Time Factors
chemical_list: D010100:Oxygen