title: Correlations of brain MRI parameters to disability in multiple sclerosis.
abstract: OBJECTIVE
  The objective was to correlate magnetic resonance imaging (MRI) T2-weighted lesion load and measures of white matter atrophy in the brain to disability in a population-based sample of patients with multiple sclerosis (MS).
  
  
  METHODS
  A well defined cohort of patients was drawn at random from the general MS population by using the Danish Multiple Sclerosis Registry. A semi-automated local thresholding technique was used to quantify T2-weighted lesions on MRI; whereas manual tracing was applied to measure the corpus callosum brain ratio (CCR) and the ventricle brain ratio (VBR).
  
  
  RESULTS
  A sample of 86 patients with a mean age of 43.3 years (SD 4.3), mean disease duration of 13.6 years (SD 4.4) and a median Expanded Disability Status Score (EDSS) of 6.0 was identified. The correlation between total lesion area of the brain (TLA) and disability (EDSS) for the whole sample was moderate (Spearman rank correlation coefficient r=0.48, P<0.001). Also correlations of CCR and VBR to disability (r=0.32-0.46) were significant.
  
  
  CONCLUSIONS
  Correlations of TLA and disability in this study were rather strong. Hence, T2-weighted MRI lesion load in the brain still plays an important role as a surrogate marker of disease and as a secondary outcome measure in phase III treatment trials.
authors.affiliation: Copenhagen University Hospital, Rigshospital, Department of Neurology, Denmark.
authors.forename: K
authors.initials: K
authors.lastname: Schreiber
authors.forename: P S
authors.initials: PS
authors.lastname: Sørensen
authors.forename: N
authors.initials: N
authors.lastname: Koch-Henriksen
authors.forename: A
authors.initials: A
authors.lastname: Wagner
authors.forename: M
authors.initials: M
authors.lastname: Blinkenberg
authors.forename: C
authors.initials: C
authors.lastname: Svarer
authors.forename: H C
authors.initials: HC
authors.lastname: Petersen
mesh_terms: D000328:Adult; D001284:Atrophy; D015415:Biomarkers / Q000032:analysis; D001921:Brain / Q000473:pathology*; D015331:Cohort Studies; D006233:Persons with Disabilities; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009103:Multiple Sclerosis / Q000473:pathology*; D012720:Severity of Illness Index
chemical_list: D015415:Biomarkers