title: Development and preliminary validation of a magnetic resonance imaging joint space narrowing score for use in rheumatoid arthritis: potential adjunct to the OMERACT RA MRI scoring system.
abstract: OBJECTIVE
  To develop and validate a magnetic resonance imaging (MRI) method of assessment of joint space narrowing (JSN) in rheumatoid arthritis (RA).
  
  
  METHODS
  Phase A: JSN was scored 0-4 on MR images of 5 RA patients and 3 controls at 15 wrist sites and 2nd-5th metacarpophalangeal (MCP) joints by 8 readers (7 once, one twice), using a preliminary scoring system. Phase B: Image review, discussion, and consensus on JSN definition, and revised scoring system. Phase C: MR images of 15 RA patients and 4 controls were scored using revised system by 5 readers (4 once, one twice), and results compared with radiographs [Sharp-van der Heijde (SvdH) method].
  
  
  RESULTS
  Phase A: Intraobserver agreement: intraclass correlation coefficient (ICC) = 0.99; smallest detectable difference (SDD, for mean of readings) = 2.8 JSN units (4.9% of observed maximal score). Interobserver agreement: ICC = 0.93; SDD = 6.4 JSN units (9.9%). Phase B: Agreement was reached on JSN definition (reduced joint space width compared to normal, as assessed in a slice perpendicular to the joint surface), and revised scoring system (0-4 at 17 wrist sites and 2nd-5th MCP; 0: none; 1: 1-33%; 2: 34-66%; 3: 67-99%; 4: ankylosis). Phase C: Intraobserver agreement: ICC = 0.90; SDD = 6.8 JSN units (11.0%). Interobserver agreement: ICC = 0.92 and SDD = 6.2 JSN units (8.7%). The correlation (ICC) with the SvdH radiographic JSN score of the wrist/hand was 0.77. Simplified approaches evaluating fewer joint spaces demonstrated similar reliability and correlation with radiographic scores.
  
  
  CONCLUSIONS
  An MRI scoring system of JSN in RA wrist and MCP joints was developed and showed construct validity and good intra- and interreader agreements. The system may, after further validation in longitudinal data sets, be useful as an outcome measure in RA.
authors: Department of Rheumatology, Copenhagen University Hospital at Glostrup, Copenhagen, Denmark. mo@dadlnet.dk
authors: Mikkel
authors: M
authors: Ostergaard
authors: Pernille
authors: P
authors: Bøyesen
authors: Iris
authors: I
authors: Eshed
authors: Frédérique
authors: F
authors: Gandjbakhch
authors: Siri
authors: S
authors: Lillegraven
authors: Paul
authors: P
authors: Bird
authors: Violaine
authors: V
authors: Foltz
authors: Annelies
authors: A
authors: Boonen
authors: Marissa
authors: M
authors: Lassere
authors: Kay-Geert
authors: KG
authors: Hermann
authors: Allen
authors: A
authors: Anandarajah
authors: Uffe Møller
authors: UM
authors: Døhn
authors: Jane
authors: J
authors: Freeston
authors: Charles G
authors: CG
authors: Peterfy
authors: Harry K
authors: HK
authors: Genant
authors: Espen A
authors: EA
authors: Haavardsholm
authors: Fiona M
authors: FM
authors: McQueen
authors: Philip G
authors: PG
authors: Conaghan
mesh_terms: D000328:Adult; D000368:Aged; D001172:Arthritis, Rheumatoid / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000473:pathology*; D001175:Arthrography / Q000592:standards; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods* / Q000592:standards*; D008297:Male; D008662:Metacarpophalangeal Joint / Q000000981:diagnostic imaging / Q000473:pathology*; D008875:Middle Aged; D015588:Observer Variation; D010865:Pilot Projects; D012720:Severity of Illness Index