title: Molecular imaging of cartilage damage of finger joints in early rheumatoid arthritis with delayed gadolinium-enhanced magnetic resonance imaging.
abstract: OBJECTIVE
  To assess cartilage glycosaminoglycan content and cartilage thickness in the metacarpophalangeal (MCP) joints of patients with early rheumatoid arthritis (RA) and healthy volunteers.
  
  
  METHODS
  After review board approval and informed consent were obtained, 22 subjects were prospectively enrolled (9 patients with early RA [7 women and 2 men with a mean ± SD age of 49 ± 13 years; range 25-68 years] and 13 healthy volunteers [10 women and 3 men with a mean ± SD age of 51 ± 12 years; range 25-66 years). In a total of 44 MCP joints of the index and middle fingers, measurements of cartilage thickness and delayed gadolinium-enhanced magnetic resonance imaging (MRI) of cartilage (dGEMRIC) index (T1 [msec]) were obtained using the variable flip-angle method and a 3T MR scanner. MRIs were evaluated for bone edema, erosions, and synovitis (using the RA MRI Scoring criteria). Student's t-test was used to test the significance of differences between groups.
  
  
  RESULTS
  The mean ± SD dGEMRIC index was 497 ± 86 msec in healthy volunteers and was significantly lower in the early RA group (421 ± 76 msec) (P = 0.042). There was no joint space narrowing seen on standard radiographs. No significant difference was found between cartilage thickness in patients with early RA and that in controls (index finger mean ± SD 1.27 ± 0.23 mm in RA patients versus 1.46 ± 0.34 mm in controls [P = 0.16] and middle finger 1.26 ± 0.23 mm in RA patients versus 0.97 ± 0.47 mm in controls [P = 0.10]). No significant correlation was noted between cartilage thickness and dGEMRIC index (R = 0.36, P = 0.88 in RA patients; R = 0.156, P = 0.445 in controls).
  
  
  CONCLUSIONS
  Our findings indicate that cartilage damage is present in the MCP joints of patients with early RA despite the absence of joint space narrowing on standard radiographs and MRI. Cartilage damage in RA can be imaged with dGEMRIC.
authors.affiliation: University Dusseldorf, Medical Faculty, Department of Diagnostic and Interventional Radiology, Dusseldorf, Germany.
authors.forename: Falk
authors.initials: F
authors.lastname: Miese
authors.forename: Christian
authors.initials: C
authors.lastname: Buchbender
authors.forename: Axel
authors.initials: A
authors.lastname: Scherer
authors.forename: Hans-Jörg
authors.initials: HJ
authors.lastname: Wittsack
authors.forename: Christof
authors.initials: C
authors.lastname: Specker
authors.forename: Matthias
authors.initials: M
authors.lastname: Schneider
authors.forename: Gerald
authors.initials: G
authors.lastname: Antoch
authors.forename: Benedikt
authors.initials: B
authors.lastname: Ostendorf
mesh_terms: D000328:Adult; D000368:Aged; D001172:Arthritis, Rheumatoid / Q000378:metabolism / Q000473:pathology*; D002358:Cartilage, Articular / Q000378:metabolism / Q000473:pathology*; D005260:Female; D005682:Gadolinium; D006025:Glycosaminoglycans / Q000378:metabolism*; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008662:Metacarpophalangeal Joint / Q000378:metabolism / Q000473:pathology*; D008875:Middle Aged; D057054:Molecular Imaging
chemical_list: D006025:Glycosaminoglycans; D005682:Gadolinium