Ultrasonography in gout: utility in diagnosis and monitoring.

The use of ultrasonography has a considerable potential for diagnosis and monitoring of gout due to its capacity to detect urate crystal deposits in joints, e.g. on the cartilage surface, visualised as the double contour sign, and in soft tissues, e.g. as tophi. Furthermore, ultrasonography can visualise both synovitis and bone erosion. Consensus-based definitions for ultrasonographic elementary lesions in gout were validated in 2015, and ultrasonography is already included in the 2015 ACR/EULAR classification criteria for gout. This report evaluates the current literature on the use of ultrasonography for diagnosing and monitoring gout.