title: Development and validation of rheumatoid arthritis magnetic resonance imaging inflammation thresholds associated with lack of damage progression.
abstract: OBJECTIVE
  To determine thresholds for rheumatoid arthritis (RA) magnetic resonance imaging scores (RAMRIS) associated with a low risk of structural damage progression.
  
  
  METHODS
  MRI of the dominant hand was performed and RAMRIS scores determined at weeks 0, 24, and 52. X-rays were performed and van der Heijde-Sharp scores (vdHS) determined. In a development cohort (n=297) the changes in MRI erosion score and vdHS score were determined over the 24-week to 52-week interval and progression was defined as change >0.5. We identified 24-week thresholds for synovitis and osteitis that provided >90% sensitivity for imaging progression over the 24 to 52-week interval. The performance of these cut-offs was tested in a validation cohort (n=217).
  
  
  RESULTS
  In the development cohort, synovitis or osteitis scores ≤3 by 24 weeks were associated with a low probability of progression on MRI and x-ray. The coefficient for osteitis was stronger than that of synovitis in models predicting x-ray and MRI progression. Therefore, a total inflammation score was weighted on osteitis (x2). An inflammation score ≤9 was more frequently attained than DAS28 remission (64 vs. 38) and was associated with low probability of progression regardless of attainment of clinical remission. In the validation cohort, there was a low odds of MRI progression among those with low synovitis [OR 0.27 (0.086,0.82) p=0.02], osteitis [OR 0.20 (0.085, 0.49) p<0.001] and inflammation scores [OR 0.12 (0.033, 0.41) p=0.001].
  
  
  CONCLUSIONS
  Attainment of low MRI single-hand synovitis and osteitis is not uncommon and predicts a lack of structural progression in RA, independent of clinical remission.
authors.affiliation: Philadelphia Veterans Affairs Medical Center; University of Pennsylvania, School of Medicine; and Center for Clinical Epidemiology and Biostatistics, University of Pennsylvania, Philadelphia, USA. bakerjo@uphs.upenn.edu.
authors.forename: Joshua F
authors.initials: JF
authors.lastname: Baker
authors.affiliation: Copenhagen Center for Arthritis Research, Center for Rheumatology and Spine Diseases, Rigshospitalet, Glostrup; and Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Denmark.
authors.forename: Mikkel
authors.initials: M
authors.lastname: Østergaard
authors.affiliation: Leeds Institute of Rheumatic and Musculoskeletal Medicine, University of Leeds, and NIHR Leeds Musculoskeletal Biomedical Research Unit, Leeds, UK.
authors.forename: Paul
authors.initials: P
authors.lastname: Emery
authors.affiliation: Janssen Research & Development, LLC., Horsham PA, USA.
authors.forename: Daniel G
authors.initials: DG
authors.lastname: Baker
authors.affiliation: Leeds Institute of Rheumatic and Musculoskeletal Medicine, University of Leeds, and NIHR Leeds Musculoskeletal Biomedical Research Unit, Leeds, UK.
authors.forename: Philip G
authors.initials: PG
authors.lastname: Conaghan
mesh_terms: D000328:Adult; D001172:Arthritis, Rheumatoid / Q000000981:diagnostic imaging*; D015331:Cohort Studies; D018450:Disease Progression; D005260:Female; D050823:Hand Joints / Q000000981:diagnostic imaging*; D006801:Humans; D007249:Inflammation / Q000000981:diagnostic imaging; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D010000:Osteitis / Q000000981:diagnostic imaging*; D011859:Radiography; D013585:Synovitis / Q000000981:diagnostic imaging*