title: Assessment of cartilage loss at the wrist in rheumatoid arthritis using a new MRI scoring system.
abstract: OBJECTIVE
  To develop and test an MRI cartilage scoring system for use at the wrist in rheumatoid arthritis (RA).
  
  
  METHODS
  MRI scans were obtained using a 3T MRI scanner with dedicated wrist coil in 22 early and 16 established RA patients plus 22 controls. Axial and coronal T1-weighted (precontrast and postcontrast) and T2-weighted turbo spin echo sequences were obtained. Eight wrist joints were scored for cartilage narrowing: distal radioulnar, radiolunate, radioscaphoid, triquetrum-hamate, capitate-lunate, scaphotrapezoid, second metacarpal base-trapezoid and third metacarpal base-capitate, using a system based on the Sharp van der Heijde x-ray joint space narrowing (JSN) score by three radiologists. Fifteen sites at the wrist were also scored for synovitis, bone oedema and erosion using the RA MRI score.
  
  
  RESULTS
  Interobserver (three-reader) and intraobserver reliability (readers 1 and 2) for the cartilage score were excellent: intraclass correlations (ICC (95% CI)) 0.91, (0.86 to 0.94), 0.98 (0.96 to 1.00) and 0.94 (0.87 to 1.00), respectively. Cartilage scores (median, range) were higher in the established RA group (11.9, 2.3-27.3) than the early RA group (2.15, 0-6) (p≤0.001) but early RA scores did not differ from healthy controls (2.3, 1-8.7). Cartilage scores correlated with synovitis (R=0.52), bone oedema (R=0.63) and erosion scores (R=0.66), p<0.001 for all, and with x-ray JSN scores (R=0.68 to 0.78).
  
  
  CONCLUSIONS
  This MRI cartilage score demonstrated excellent reliability when tested in a three-reader system. However, cartilage loss in early RA could not be distinguished from that seen in healthy controls.
authors.affiliation: Department of Molecular Medicine and Pathology, University of Auckland, New Zealand. f.mcqueen@auckland.ac.nz
authors.forename: Fiona
authors.initials: F
authors.lastname: McQueen
authors.forename: Andrew
authors.initials: A
authors.lastname: Clarke
authors.forename: Alex
authors.initials: A
authors.lastname: McHaffie
authors.forename: Quentin
authors.initials: Q
authors.lastname: Reeves
authors.forename: Megan
authors.initials: M
authors.lastname: Williams
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Robinson
authors.forename: Jing
authors.initials: J
authors.lastname: Dong
authors.forename: Arista
authors.initials: A
authors.lastname: Chand
authors.forename: Desiree
authors.initials: D
authors.lastname: Mulders
authors.forename: Nicola
authors.initials: N
authors.lastname: Dalbeth
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001172:Arthritis, Rheumatoid / Q000150:complications / Q000473:pathology*; D001855:Bone Marrow Diseases / Q000175:diagnosis / Q000209:etiology; D002358:Cartilage, Articular / Q000000981:diagnostic imaging / Q000473:pathology*; D016022:Case-Control Studies; D004487:Edema / Q000175:diagnosis / Q000209:etiology; D005260:Female; D033023:Foot Joints / Q000000981:diagnostic imaging; D050823:Hand Joints / Q000000981:diagnostic imaging; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D011859:Radiography; D015203:Reproducibility of Results; D013585:Synovitis / Q000175:diagnosis / Q000209:etiology; D014955:Wrist Joint / Q000473:pathology*