title: Exploring cartilage damage in gout using 3-T MRI: distribution and associations with joint inflammation and tophus deposition.
abstract: OBJECTIVE
  Few imaging studies have investigated cartilage in gout. Magnetic resonance imaging (MRI) can image cartilage damage and also reveals other features of gouty arthropathy. The objective was to develop and validate a system for quantifying cartilage damage in gout.
  
  
  METHODS
  3-T MRI scans of the wrist were obtained in 40 gout patients. MRI cartilage damage was quantified using an adaptation of the radiographic Sharp van der Heijde score. Two readers scored cartilage loss at 7 wrist joints: 0 (normal), 1 (partial narrowing), 2 (complete narrowing) and concomitant osteoarthritis was recorded. Bone erosion, bone oedema and synovitis were scored (RAMRIS) and tophi were assessed. Correlations between radiographic and MRI cartilage scores were investigated, as was the reliability of the MRI cartilage score and its associations.
  
  
  RESULTS
  The GOut MRI Cartilage Score (GOMRICS) was highly correlated with the total Sharp van der Heijde (SvdH) score and the joint space narrowing component (R = 0.8 and 0.71 respectively, p < 0.001). Reliability was high (intraobserver, interobserver ICCs = 0.87 [0.57-0.97], 0.64 [0.41-0.79] respectively), and improved on unenhanced scans; interobserver ICC = 0.82 [0.49-0.95]. Cartilage damage was predominantly focal (82% of lesions) and identified in 40 out of 280 (14%) of joints. Cartilage scores correlated with bone erosion (R = 0.57), tophus size (R = 0.52), and synovitis (R = 0.55), but not bone oedema scores.
  
  
  CONCLUSIONS
  Magnetic resonance imaging can be used to investigate cartilage in gout. Cartilage damage was relatively uncommon, focal, and associated with bone erosions, tophi and synovitis, but not bone oedema. This emphasises the unique pathophysiology of gout.
authors.affiliation: Department of Molecular Medicine and Pathology, Faculty of Medical and Health Sciences, University of Auckland, 85 Park Road, Grafton, Auckland, New Zealand.
authors.forename: I
authors.initials: I
authors.lastname: Popovich
authors.forename: N
authors.initials: N
authors.lastname: Dalbeth
authors.forename: A
authors.initials: A
authors.lastname: Doyle
authors.forename: Q
authors.initials: Q
authors.lastname: Reeves
authors.forename: F M
authors.initials: FM
authors.lastname: McQueen
mesh_terms: D000328:Adult; D000368:Aged; D001168:Arthritis / Q000150:complications / Q000378:metabolism / Q000473:pathology*; D002357:Cartilage Diseases / Q000209:etiology / Q000378:metabolism / Q000473:pathology*; D002358:Cartilage, Articular / Q000378:metabolism / Q000473:pathology*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D014018:Tissue Distribution; D014527:Uric Acid / Q000378:metabolism; D014955:Wrist Joint / Q000378:metabolism / Q000473:pathology*
chemical_list: D014527:Uric Acid