title: Correlates of MS disability assessed in vivo using aggregates of MR quantities.
abstract: OBJECTIVE
  To assess the magnitude of the correlations between disability and composite MRI scores in patients with MS.
  
  
  METHODS
  T2- and T1-weighted MRI, magnetization transfer imaging, diffusion tensor imaging, and MRS imaging scans of the brain from 23 patients with MS were obtained. T2 lesion volume, T1 lesion volume, brain magnetization transfer ratio, average brain diffusivity (D), and brain N-acetylaspartate/creatine ratio were measured.
  
  
  RESULTS
  The correlations between the Expanded Disability Status Scale (EDSS) score and each of the MR quantities taken in isolation were not significant, with the exception of the correlation between EDSS and the NAA/creatine ratio (r = -0.50; p = 0.01). In contrast, three of the composite MR scores computed using regression models were strongly correlated with the EDSS scores (r range, 0.58 to 0.73; p range, 0.004 to 0.0001). The model that included T2 and T1 lesion volumes and brain D explained 34% of the EDSS variance; the model that included T2 and T1 lesion volumes and brain N-acetylaspartate/creatine ratio explained 36% of the EDSS variance; the model that included T1 lesion volume, brain D, and brain N-acetylaspartate/creatine ratio explained 53% of the EDSS variance.
  
  
  CONCLUSIONS
  The results suggest that multiparametric MR models have the potential to provide powerful measures to monitor MS evolution.
authors.affiliation: Neuroimaging Research Unit, Department of Neuroscience, Scientific Institute and University Ospedale San Raffaele, Milan, Italy.
authors.forename: C
authors.initials: C
authors.lastname: Mainero
authors.forename: N
authors.initials: N
authors.lastname: De Stefano
authors.forename: G
authors.initials: G
authors.lastname: Iannucci
authors.forename: M P
authors.initials: MP
authors.lastname: Sormani
authors.forename: L
authors.initials: L
authors.lastname: Guidi
authors.forename: A
authors.initials: A
authors.lastname: Federico
authors.forename: M L
authors.initials: ML
authors.lastname: Bartolozzi
authors.forename: G
authors.initials: G
authors.lastname: Comi
authors.forename: M
authors.initials: M
authors.lastname: Filippi
mesh_terms: D000328:Adult; D001224:Aspartic Acid / Q000031:analogs & derivatives / Q000378:metabolism; D001921:Brain / Q000378:metabolism / Q000473:pathology* / Q000503:physiopathology*; D003401:Creatine / Q000378:metabolism; D004185:Disability Evaluation; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D008959:Models, Neurological; D009103:Multiple Sclerosis / Q000378:metabolism / Q000473:pathology* / Q000503:physiopathology*; D011237:Predictive Value of Tests
chemical_list: D001224:Aspartic Acid; C000179:N-acetylaspartate; D003401:Creatine