title: Voxel-based analysis of MTR images: a method to locate gray matter abnormalities in patients at the earliest stage of multiple sclerosis.
abstract: OBJECTIVE
  To determine whether voxel-based analysis of magnetization transfer ratio (MTR) maps can provide evidence of a coherent pattern of gray matter (GM) macroscopic and microscopic tissue damage in patients at the earliest stage of multiple sclerosis (MS).
  
  
  METHODS
  We acquired GM MTR maps in 18 patients with clinically isolated syndrome suggestive of MS (CISSMS), and 18 sex- and age-matched healthy controls. We evaluated the clinical status of the patients using the MS functional composite score and the expanded disability status scale. A two-sample t-test (P <0.0001, k=20, uncorrected for height threshold) was used to compare GM MTR maps from patients and controls on a voxel-by-voxel basis. We then extracted data from regions with t-values above the statistical threshold to verify the significance of differences using a nonparametric Mann-Whitney U-test.
  
  
  RESULTS
  A between-groups comparison of GM maps revealed large abnormalities in the basal ganglia, including the bilateral thalamus, bilateral lenticular nucleus, bilateral head of caudate, and protuberance, and smaller abnormalities in the right insula, right BA 4, and left BA 40. The MTR measured in the left caudate and right insula was inversely correlated with duration following the first clinical event.
  
  
  CONCLUSIONS
  These results suggest that although MS is a multifocal demyelinating disease that affects white matter (WM), a pattern of tissue damage is present inside the GM involving predominantly basal ganglia at the earliest stage of the disease.
authors.affiliation: Centre de Résonance Magnétique Biologique et Médicale (CRMBM), UMR CNRS 6612, Faculté de Médecine, Marseille, France.
authors.forename: Bertrand
authors.initials: B
authors.lastname: Audoin
authors.forename: Jean-Philippe
authors.initials: JP
authors.lastname: Ranjeva
authors.forename: My Van
authors.initials: MV
authors.lastname: Au Duong
authors.forename: Danielle
authors.initials: D
authors.lastname: Ibarrola
authors.forename: Irina
authors.initials: I
authors.lastname: Malikova
authors.forename: Sylviane
authors.initials: S
authors.lastname: Confort-Gouny
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Soulier
authors.forename: Patrick
authors.initials: P
authors.lastname: Viout
authors.forename: André
authors.initials: A
authors.lastname: Ali-Chérif
authors.forename: Jean
authors.initials: J
authors.lastname: Pelletier
authors.forename: Patrick J
authors.initials: PJ
authors.lastname: Cozzone
mesh_terms: D000328:Adult; D001921:Brain / Q000473:pathology*; D001931:Brain Mapping / Q000379:methods; D018450:Disease Progression; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D009103:Multiple Sclerosis / Q000175:diagnosis*; D012016:Reference Values; D018709:Statistics, Nonparametric