title: Urate crystal deposition in asymptomatic hyperuricaemia and symptomatic gout: a dual energy CT study.
abstract: BACKGROUND
  The aim of this study was to compare the frequency and volume of dual energy CT (DECT) urate deposits in people with asymptomatic hyperuricaemia and symptomatic gout.
  
  
  METHODS
  We analysed DECT scans of the feet from asymptomatic individuals with serum urate ≥540 µmol/L (n=25) and those with crystal proven gout without clinically apparent tophi (n=33).
  
  
  RESULTS
  DECT urate deposits were observed in 6/25 (24%) participants with asymptomatic hyperuricaemia, 11/14 (79%) with early gout (predefined as disease duration ≤3 years) and 16/19 (84%) with late gout (p<0.001). DECT urate deposition was observed in both joints and tendons in the asymptomatic hyperuricaemia group, but significantly less frequently than in those with gout (p≤0.001 for both joint and tendon sites). The volume of urate deposition was also significantly lower in those with asymptomatic hyperuricaemia, compared with the early and the late gout groups (p<0.01 for both comparisons). Similar urate volumes were observed in the early and late gout groups.
  
  
  CONCLUSIONS
  Although subclinical urate deposition can occur in people with asymptomatic hyperuricaemia, these deposits occur more frequently and at higher volumes in those with symptomatic gout. These data suggest that a threshold of urate crystal volume may be required before symptomatic disease occurs.
authors: Faculty of Medical and Health Sciences, Department of Medicine, Bone and Joint Research Group, University of Auckland, Auckland, New Zealand.
authors: Nicola
authors: N
authors: Dalbeth
authors: Faculty of Medical and Health Sciences, Department of Medicine, Bone and Joint Research Group, University of Auckland, Auckland, New Zealand.
authors: Meaghan E
authors: ME
authors: House
authors: Faculty of Medical and Health Sciences, Department of Medicine, Bone and Joint Research Group, University of Auckland, Auckland, New Zealand.
authors: Opetaia
authors: O
authors: Aati
authors: Faculty of Medical and Health Sciences, Department of Medicine, Bone and Joint Research Group, University of Auckland, Auckland, New Zealand.
authors: Paul
authors: P
authors: Tan
authors: Faculty of Medical and Health Sciences, Department of Medicine, Bone and Joint Research Group, University of Auckland, Auckland, New Zealand.
authors: Christopher
authors: C
authors: Franklin
authors: Faculty of Medical and Health Sciences, Department of Medicine, Bone and Joint Research Group, University of Auckland, Auckland, New Zealand.
authors: Anne
authors: A
authors: Horne
authors: Faculty of Medical and Health Sciences, Department of Medicine, Bone and Joint Research Group, University of Auckland, Auckland, New Zealand.
authors: Gregory D
authors: GD
authors: Gamble
authors: Department of Medicine, University of Otago, Christchurch, New Zealand.
authors: Lisa K
authors: LK
authors: Stamp
authors: Faculty of Medical and Health Sciences, Department of Anatomy with Radiology, University of Auckland, Auckland, New Zealand.
authors: Anthony J
authors: AJ
authors: Doyle
authors: Faculty of Medical and Health Sciences, Department of Molecular Medicine, University of Auckland, Auckland, New Zealand.
authors: Fiona M
authors: FM
authors: McQueen
mesh_terms: D015502:Absorptiometry, Photon; D000368:Aged; D058070:Asymptomatic Diseases; D003430:Cross-Sectional Studies; D005260:Female; D005528:Foot / Q000000981:diagnostic imaging; D033023:Foot Joints / Q000000981:diagnostic imaging*; D006073:Gout / Q000097:blood / Q000000981:diagnostic imaging*; D006801:Humans; D033461:Hyperuricemia / Q000097:blood / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D013710:Tendons / Q000000981:diagnostic imaging*; D014057:Tomography, X-Ray Computed; D014527:Uric Acid / Q000097:blood*
chemical_list: D014527:Uric Acid
keywords: Arthritis; Gout; Inflammation