A systematic review of ultrasonography in gout and asymptomatic hyperuricaemia.

Gout is one of the most common inflammatory arthritides. The literature reveals that management of this condition is often suboptimal. Imaging techniques, such as ultrasound (US), may assist in the diagnosis and management of gout and asymptomatic hyperuricaemia (AH). To undertake a systematic review evaluating US as an outcome tool in gout and asymptomatic hyperuricaemia, articles published in Medline and PubMed (1975-February 2012) were identified. Data was extracted and categorised into four different groups namely tophi, articular cartilage, soft tissue pathologies and bony changes, with a focus on validity, responsiveness, reproducibility and feasibility. Lesions reported in the literature include tophi, cartilage abnormalities, soft tissue lesions and erosions. US is able to detect tophi, using MRI as the gold standard, and is sensitive to change. The double contour sign seen overlying cartilage is specific to gout and sensitive to change. Synovial pathology is identified in gout, with some reporting intrasynovial hyperechogeneicity is suggestive of gout. US was less sensitive than MRI to cortical erosions in gout, but better than conventional radiography. Interobserver reliability when assessed ranged from fair to substantial agreement for soft tissue changes and was very good for assessing tophi, double contour and erosions. US is a promising tool which could be used in the diagnosis and management of gout. More studies are needed to assess responsiveness, reliability and feasibility.