Online Images in the Medical Sciences| Volume 364, ISSUE 3, e27-e28, September 2022

Green pixels on DECT: Is it gout?

  • Mark McPherson
    Corresponding author at: Department of Medicine, Chandler Regional Medical Center, Chandler, AZ, USA. The work was done at Mayo Clinic and this should be the main, affiliation address.
    Department of Medicine, Chandler Regional Medical Center, Chandler, AZ, USA
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  • Fawad Aslam
    Department of Medicine, Division of Rheumatology, Mayo Clinic Hospital, Phoenix, AZ, USA
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Published:February 10, 2022DOI:
      An 80-year-old man developed pain and swelling of both knees while hospitalized with an acute viral illness causing significant dehydration and hyponatremia. He denied having any prior history of gout however did have a brother with a diagnosis of gout. Large bilateral knee effusions were seen on physical exam without overlying redness or tophi present. Lab work was significant for elevated C- reactive protein at 190 mg/dL and uric acid below normal range at 3.3 mg/dL. His leukocyte count and renal function were unremarkable. A right knee x-ray showed mild osteoarthritis, chondrocalcinosis, and a large effusion. The primary hospital team ordered a dual-energy CT scan (DECT) of his knees which showed diffuse chondrocalcinosis (Panel A, arrow), monosodium urate (MSU) deposition in bilateral knees (Panel B, arrows), large joint effusions, and tricompartmental osteoarthritis (OA). Given findings of MSU deposition on DECT, rheumatology was consulted who performed aspiration of both knees and injected corticosteroids. Synovial fluid showed intracellular calcium pyrophosphate (CPP) crystals; MSU crystals were absent. Cultures were negative for infection. Given the synovial fluid findings, he was diagnosed with acute CPP crystal arthritis. The patient's knee pain subsided for several months. He subsequently had a flare of knee pain and swelling about 6 months later, which was again alleviated with triamcinolone injection in the clinic. He was offered prophylactic treatment with daily colchicine however he declined in favor of a wait and see approach.
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        • Ogdie A
        • Taylor WJ
        • Weatherall M
        • et al.
        Imaging modalities for the classification of gout: Systematic literature review and meta-analysis.
        Ann Rheum Dis. 2015; 74: 1868-1874
        • Dalbeth N
        • House ME
        • Aati O
        • et al.
        Urate crystal deposition in asymptomatic hyperuricaemia and symptomatic gout: a dual energy CT study.
        Ann Rheum Dis. 2015 May; 74 (Epub 2015 Jan 30. PMID:25637002): 908-911
        • Chou H
        • Chin TY
        • Peh WC.
        Dual-energy CT in gout - A review of current concepts and applications.
        J Med Radiat Sci. 2017 Mar; 64 (Epub 2017 Feb 26. PMID:28238226; PMCID: PMC5355369): 41-51