Gout. Imaging of Gout: Findings and Utility

From Arthritis Research & Therapy
Fernando Perez-Ruiz; Nicola Dalbeth; Aranzazu Urresola; Eugenio de Miguel; Naomi Schlesinger

Abstract
Imaging is a helpful tool for clinicians to evaluate diseases that induce chronic joint inflammation.
Chronic gout is associated with changes in joint structures that may be evaluated with diverse imaging techniques.
Plain radiographs show typical changes only in advanced chronic gout.
Computed tomography may best evaluate bone changes, whereas magnetic resonance imaging is suitable to evaluate soft tissues, synovial membrane thickness, and inflammatory changes.
Ultrasonography is a tool that may be used in the clinical setting, allowing evaluation of cartilage, soft tissues, urate crystal deposition, and synovial membrane inflammation. Also ultrasound-guided puncture may be useful for obtaining samples for crystal observation.
Any of these techniques deserve some consideration for feasibility and implementation both in clinical practice and as outcome measures for clinical trials. In clinical practice they may be considered mainly for evaluating the presence and extent of crystal deposition, and structural changes that may impair function or functional outcomes, and also to monitor the response to urate-lowering therapy.

Introduction
Gout is a disease caused by deposition of monosodium urate (MSU) monohydrate crystals that induce not only acute episodes of inflammation, but also, in the long-term history of the disease, chronic inflammation that is associated with changes in articular and periarticular structures.
Imaging may be useful to evaluate the severity of disease (measurement of structural joint changes), the extent of MSU deposition (location and magnitude of urate deposition), and the presence of chronic inflammation.[1]
In addition, as an outcome measure, imaging may allow estimation of the change of these variables during urate-lowering therapy; that is, as MSU crystals dissolute due to the long-term effect of subsaturating serum urate levels achieved during urate-lowering therapy.[2] If so, imaging would also provide a useful tool to monitor the response to urate-lowering therapy.

http://www.medscape.com/viewarticle/715155?src=mp&spon=27&uac=71630FV