title: The OMERACT-RAMRIS rheumatoid arthritis magnetic resonance imaging joint space narrowing score: intrareader and interreader reliability and agreement with computed tomography and conventional radiography.
abstract: OBJECTIVE
  To test the intrareader and interreader reliability of assessment of joint space narrowing (JSN) in rheumatoid arthritis (RA) wrist and metacarpophalangeal (MCP) joints on magnetic resonance imaging (MRI) and computed tomography (CT) using the newly proposed OMERACT-RAMRIS JSN scoring method, and to compare JSN assessment on MRI, CT, and radiography.
  
  
  METHODS
  After calibration of readers, MRI and CT images of the wrist and second to fifth MCP joints from 14 patients with RA and 1 healthy control were assessed twice for JSN by 3 readers, blinded to clinical and imaging data. Radiographs were scored by the Sharp/van der Heijde method. Intraclass correlation coefficients (ICC) and smallest detectable differences (SDD) were calculated, and the performance of various simplified scores was investigated.
  
  
  RESULTS
  Both MRI and CT showed high intrareader (ICC ≥ 0.95) and interreader (ICC ≥ 0.94) reliability for total (wrist + MCP) assessment of JSN. Agreement was generally lower for MCP joints than for wrist joints, particularly for CT. Intrareader SDD for MCP/wrist/MCP + wrist were 1.2/6.1/6.4 JSN units for MRI, while 2.7/8.3/9.9 JSN units for CT. JSN on MRI and CT correlated moderately well with corresponding radiographic JSN scores (MCP 2-5: 0.49 and 0.56; wrist areas assessed by Sharp/van der Heijde: 0.80 and 0.95), and high ICC between scores on MRI and CT were demonstrated (MCP: 0.94; wrist: 0.92; MCP + wrist: 0.92).
  
  
  CONCLUSIONS
  The OMERACT-RAMRIS MRI JSN scoring system showed high intrareader and interreader reliability, and high correlation with CT scores of JSN. The suggested JSN score may, after further validation in longitudinal studies, become a useful tool in RA clinical trials.
authors.affiliation: From the Center for Rheumatology and Spine Diseases, Copenhagen University Hospital Glostrup, Denmark; University of Leeds and the UK National Institute for Health Research (NIHR) Leeds Musculoskeletal Biomedical Research Unit, Leeds, UK; Sheba Medical Center, Tel Aviv University, Tel Aviv, Israel; Maastricht University Medical Center, Maastricht, Netherlands; Diakonhjemmet Hospital, Oslo, Norway; University of California, San Francisco, CA, USA; Slagelse University Hospital, Copenhagen, Denmark; Pitié Salpêtriere Hospital, Paris, France; University of New South Wales (NSW), Sydney, Australia; and University of Auckland, Auckland, New Zealand.
authors.forename: Uffe Møller
authors.initials: UM
authors.lastname: Døhn
authors.forename: Philip G
authors.initials: PG
authors.lastname: Conaghan
authors.forename: Iris
authors.initials: I
authors.lastname: Eshed
authors.forename: Annelies
authors.initials: A
authors.lastname: Boonen
authors.forename: Pernille
authors.initials: P
authors.lastname: Boyesen
authors.forename: Charles G
authors.initials: CG
authors.lastname: Peterfy
authors.forename: Siri
authors.initials: S
authors.lastname: Lillegraven
authors.forename: Bo
authors.initials: B
authors.lastname: Ejbjerg
authors.forename: Frederique
authors.initials: F
authors.lastname: Gandjbakhch
authors.forename: Paul
authors.initials: P
authors.lastname: Bird
authors.forename: Violaine
authors.initials: V
authors.lastname: Foltz
authors.forename: Harry K
authors.initials: HK
authors.lastname: Genant
authors.forename: Espen
authors.initials: E
authors.lastname: Haavardsholm
authors.forename: Fiona M
authors.initials: FM
authors.lastname: McQueen
authors.forename: Mikkel
authors.initials: M
authors.lastname: Østergaard
mesh_terms: D000328:Adult; D000368:Aged; D001172:Arthritis, Rheumatoid / Q000000981:diagnostic imaging / Q000473:pathology*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008662:Metacarpophalangeal Joint / Q000000981:diagnostic imaging / Q000473:pathology*; D008875:Middle Aged; D015588:Observer Variation; D015203:Reproducibility of Results; D012720:Severity of Illness Index; D014057:Tomography, X-Ray Computed; D014955:Wrist Joint / Q000000981:diagnostic imaging / Q000473:pathology*
keywords: COMPUTED TOMOGRAPHY; JOINT SPACE NARROWING; MAGNETIC RESONANCE IMAGING; RADIOGRAPHY; RELIABILITY; RHEUMATOID ARTHRITIS