title: Spondyloarthritis Research Consortium of Canada magnetic resonance imaging index for assessment of spinal inflammation in ankylosing spondylitis.
abstract: OBJECTIVE
  To develop a feasible magnetic resonance imaging (MRI)-based scoring system for spinal inflammation in patients with spondylarthropathy that requires minimal scan time, does not require contrast enhancement, evaluates the extent of lesions in 3 dimensional planes, and limits the number of vertebral levels that are scored because MRI demonstrates characteristic inflammatory lesions in the spine of patients with ankylosing spondylitis (AS) prior to the development of typical features on plain radiographic.
  
  
  METHODS
  Our scoring method was based entirely on the assessment of increased signal denoting bone marrow edema on T2-weighted STIR sequences. Blinded MRI films were assessed in random order at 2 sites by 3 blinded readers at each of the 2 sites (the Universities of Alberta and Toronto). Intra- and interreader reliability was assessed by intraclass correlation coefficient. The 24-week response of patients with AS randomized to infliximab:placebo (8:3) was assessed by effect size and standardized response mean.
  
  
  RESULTS
  An initial analysis of all discovertebral units (DVUs) in the spine of 11 patients demonstrated a mean of 3.2 (95% confidence interval 3.2, 5.2) affected units, while limiting the scoring to a maximum of 6 units captured most of the affected units. We scanned 11 patients with AS with clinically active disease and 20 additional patients randomized to a 24-week trial of either infliximab or placebo. Intraobserver reproducibility for the 6-DVU STIR score ranged from 0.93 to 0.98 (P < 0.0001). Interobserver reproducibility of scores by readers from both sites was 0.79 (P < 0.0001) for status score and 0.82 (P < 0.0001) for change score. Analysis of pretreatment and posttreatment scores for all 20 patients randomized to infliximab/placebo showed a large degree of responsiveness (standardized response mean = 0.87). Reproducibility and responsiveness were only slightly improved by using contrast enhancement with gadolinium diethylenetriaminepentaacetic acid.
  
  
  CONCLUSIONS
  The Spondyloarthritis Research Consortium of Canada MRI index is a feasible, reproducible, and responsive index for measuring spinal inflammation in AS.
authors.affiliation: University of Alberta, Edmonton, Alberta, Canada. walter.maksymowych@ualberta.ca
authors.forename: Walter P
authors.initials: WP
authors.lastname: Maksymowych
authors.forename: Robert D
authors.initials: RD
authors.lastname: Inman
authors.forename: David
authors.initials: D
authors.lastname: Salonen
authors.forename: Suhkvinder S
authors.initials: SS
authors.lastname: Dhillon
authors.forename: Ruben
authors.initials: R
authors.lastname: Krishnananthan
authors.forename: Millicent
authors.initials: M
authors.lastname: Stone
authors.forename: Barbara
authors.initials: B
authors.lastname: Conner-Spady
authors.forename: Janice
authors.initials: J
authors.lastname: Palsat
authors.forename: Robert G W
authors.initials: RG
authors.lastname: Lambert
mesh_terms: D000328:Adult; D000368:Aged; D000911:Antibodies, Monoclonal / Q000627:therapeutic use; D018501:Antirheumatic Agents / Q000627:therapeutic use; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D007249:Inflammation / Q000175:diagnosis; D000069285:Infliximab; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D013131:Spine; D013167:Spondylitis, Ankylosing / Q000175:diagnosis* / Q000188:drug therapy
chemical_list: D000911:Antibodies, Monoclonal; D018501:Antirheumatic Agents; D000069285:Infliximab