title: Performance of Ultrasound in the Diagnosis of Gout in a Multicenter Study: Comparison With Monosodium Urate Monohydrate Crystal Analysis as the Gold Standard.
abstract: To examine the performance of ultrasound (US) for the diagnosis of gout using the presence of monosodium urate monohydrate (MSU) crystals as the gold standard.
  
  
  
  We analyzed data from the Study for Updated Gout Classification Criteria (SUGAR), a large, multicenter observational cross-sectional study of consecutive subjects with at least 1 swollen joint who conceivably may have gout. All subjects underwent arthrocentesis; cases were subjects with confirmed MSU crystals. Rheumatologists or radiologists who were blinded with regard to the results of the MSU crystal analysis performed US on 1 or more clinically affected joints. US findings of interest were double contour sign, tophus, and snowstorm appearance. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were calculated. Multivariable logistic regression models were used to examine factors associated with positive US results among subjects with gout.
  
  
  
  US was performed in 824 subjects (416 cases and 408 controls). The sensitivity, specificity, PPV, and NPV for the presence of any 1 of the features were 76.9%, 84.3%, 83.3%, and 78.2%, respectively. Sensitivity was higher among subjects with a disease duration of ≥2 years and among subjects with subcutaneous nodules on examination (suspected tophus). Associations with a positive US finding included suspected clinical tophus (odds ratio [OR] 4.77 [95% confidence interval (95% CI) 2.23-10.21]), any abnormality on plain radiography (OR 4.68 [95% CI 2.68-8.17]), and serum urate level (OR 1.31 [95% CI 1.06-1.62]).
  
  
  
  US features of MSU crystal deposition had high specificity and high PPV but more limited sensitivity for early gout. The specificity remained high in subjects with early disease and without clinical signs of tophi.
authors.affiliation: University of Pennsylvania, Philadelphia.
authors.forename: Alexis
authors.initials: A
authors.lastname: Ogdie
authors.affiliation: University of Otago, Wellington, New Zealand.
authors.forename: William J
authors.identifier: 0000-0001-6075-8479
authors.initials: WJ
authors.lastname: Taylor
authors.affiliation: Boston University School of Medicine, Boston, Massachusetts.
authors.forename: Tuhina
authors.initials: T
authors.lastname: Neogi
authors.affiliation: VieCuri Medical Centre, Venlo, The Netherlands, and Scientific IQ HealthCare, Radboud University Medical Center, Nijmegen, The Netherlands.
authors.forename: Jaap
authors.initials: J
authors.lastname: Fransen
authors.affiliation: VieCuri Medical Centre, Venlo, The Netherlands, and Scientific IQ HealthCare, Radboud University Medical Center, Nijmegen, The Netherlands.
authors.forename: Tim L
authors.initials: TL
authors.lastname: Jansen
authors.affiliation: University of Pennsylvania, Philadelphia.
authors.forename: H Ralph
authors.initials: HR
authors.lastname: Schumacher
authors.affiliation: Chiang Mai University, Chiang Mai, Thailand.
authors.forename: Worawit
authors.initials: W
authors.lastname: Louthrenoo
authors.affiliation: Hospital General de México, Mexico City, Mexico.
authors.forename: Janitzia
authors.initials: J
authors.lastname: Vazquez-Mellado
authors.affiliation: Nasonova Research Institute of Rheumatology of Russia, Moscow, Russia.
authors.forename: Maxim
authors.initials: M
authors.lastname: Eliseev
authors.affiliation: University College Dublin and Mater Misericordiae University Hospital, Dublin, Ireland.
authors.forename: Geraldine
authors.initials: G
authors.lastname: McCarthy
authors.affiliation: University of Otago Christchurch, Christchurch, New Zealand.
authors.forename: Lisa K
authors.initials: LK
authors.lastname: Stamp
authors.affiliation: Hospital Universitario Cruces, BioCruces Health Research Institute, and Basque Country University, Barakaldo, Spain.
authors.forename: Fernando
authors.initials: F
authors.lastname: Perez-Ruiz
authors.affiliation: Hospital General Universitario de Elda, Alicante, Spain.
authors.forename: Francisca
authors.initials: F
authors.lastname: Sivera
authors.affiliation: Université Paris Diderot, INSERM UMR 1132 and Service de Rhumatologie, Hôpital Lariboisière, AP-HP, Paris, France.
authors.forename: Hang-Korng
authors.initials: HK
authors.lastname: Ea
authors.affiliation: Westfries Gasthuis, Hoorn, The Netherlands.
authors.forename: Martijn
authors.initials: M
authors.lastname: Gerritsen
authors.affiliation: University of Pavia and IRCCS Policlinico San Matteo Foundation, Pavia, Italy, and Skane University Hospital Malmö/Lund, Lund, Sweden.
authors.forename: Giovanni
authors.initials: G
authors.lastname: Cagnotto
authors.affiliation: University of Pavia and IRCCS Policlinico San Matteo Foundation, Pavia, Italy.
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Cavagna
authors.affiliation: Taichung Veterans' General Hospital, Taichung, Taiwan, Republic of China.
authors.forename: Chingtsai
authors.initials: C
authors.lastname: Lin
authors.affiliation: Taichung Veterans' General Hospital, Taichung, Taiwan, Republic of China.
authors.forename: Yin-Yi
authors.initials: YY
authors.lastname: Chou
authors.affiliation: University Hospital Carl Gustav Carus, Dresden, Germany.
authors.forename: Anne-Kathrin
authors.initials: AK
authors.lastname: Tausche
authors.affiliation: Universidade do Estado do Rio de Janeiro, Rio de Janeiro, Brazil.
authors.forename: Manuella
authors.initials: M
authors.lastname: Lima Gomes Ochtrop
authors.affiliation: Rijnstate Hospital, Arnhem, The Netherlands.
authors.forename: Matthijs
authors.initials: M
authors.lastname: Janssen
authors.affiliation: China Medical University Hospital, Taichung, Taiwan, Republic of China.
authors.forename: Jiunn-Horng
authors.identifier: 0000-0001-9292-5964
authors.initials: JH
authors.lastname: Chen
authors.affiliation: Copenhagen University Hospital Glostrup, Glostrup, Denmark.
authors.forename: Ole
authors.initials: O
authors.lastname: Slot
authors.affiliation: Riverside Professional Centre, Sydney, Nova Scotia, Canada.
authors.forename: Juris
authors.initials: J
authors.lastname: Lazovskis
authors.affiliation: Waikato District Health Board and Waikato Clinical School, Hamilton, New Zealand.
authors.forename: Douglas
authors.initials: D
authors.lastname: White
authors.affiliation: University of Genoa, Genoa, Italy.
authors.forename: Marco A
authors.initials: MA
authors.lastname: Cimmino
authors.affiliation: Diakonhjemmet Hospital, Oslo, Norway.
authors.forename: Till
authors.initials: T
authors.lastname: Uhlig
authors.affiliation: University of Auckland, Auckland, New Zealand.
authors.forename: Nicola
authors.initials: N
authors.lastname: Dalbeth
mesh_terms: D003430:Cross-Sectional Studies; D003460:Crystallization; D005260:Female; D006073:Gout / Q000097:blood* / Q000000981:diagnostic imaging*; D006801:Humans; D008297:Male; D008875:Middle Aged; D012680:Sensitivity and Specificity; D014463:Ultrasonography; D014527:Uric Acid / Q000097:blood*
chemical_list: D014527:Uric Acid