title: Imaging of gout: New tools and biomarkers?
abstract: While joint aspiration and crystal identification by polarizing microscopy remain the gold standard for diagnosing tophaceous gout, agreement among medical and ancillary health personnel examining synovial fluid using polarizing microscopy for the detection of monosodium urate (MSU) crystals appears to be poor. Imaging modalities, including conventional radiography (CR), ultrasonography (US), magnetic resonance imaging (MRI), and dual-energy computed tomography (DECT), have been found to provide information on the deposition of MSU crystals in tissues, and the consequences of such deposition. CR can demonstrate typical "punched out lesions" with marginal overhangs, but the sensitivity for erosion detection is better for DECT and US. US is inexpensive and can identify tophus deposition in and around joints, erosions, and tissue inflammation if power Doppler US is used. MRI can show tophi, bone marrow edema, and inflammation, but MRI findings of tophi may be nonspecific. DECT can identify and color-code tophaceous material, and provide an overview of the tophus burden of a joint area. Because of the lower number of available studies, the strength of evidence for the newer imaging can be improved through further research.
authors.affiliation: Department of Internal Medicine 3 and Institute for Clinical Immunology, University of Erlangen-Nuremberg, Erlangen, Germany.
authors.forename: Elizabeth G
authors.initials: EG
authors.lastname: Araujo
authors.affiliation: Department of Internal Medicine 3 and Institute for Clinical Immunology, University of Erlangen-Nuremberg, Erlangen, Germany.
authors.forename: Bernhard
authors.initials: B
authors.lastname: Manger
authors.affiliation: Rheumatology Division, Hospital de Cruces, Baracaldo, Vizcaya, Spain.
authors.forename: Fernando
authors.initials: F
authors.lastname: Perez-Ruiz
authors.affiliation: Department of Medicine, Allergy/Immunology & Rheumatology Division, University of Rochester, School of Medicine and Dentistry, Rochester, NY, USA. Electronic address: Ralf_Thiele@URMC.Rochester.edu.
authors.forename: Ralf G
authors.initials: RG
authors.lastname: Thiele
mesh_terms: D015415:Biomarkers / Q000032:analysis; D006073:Gout / Q000000981:diagnostic imaging*; D006801:Humans; D014527:Uric Acid
chemical_list: D015415:Biomarkers; D014527:Uric Acid
keywords: Imaging modalities; Monosodium urate crystals; Synovial fluid