Clinical utility of musculoskeletal ultrasound in crystal-induced arthritis

Crystal-induced arthritis (CIA) is one of the common inflammatory arthritis. There are three main types of crystals involved: monosodium urate, calcium pyrophosphate dihydrate and basic calcium phosphate. The diagnosis is sometimes difficulty to do, particularly in atypical clinical manifestation or when small joints are involved. The musculoskeletal ultrasound is an important auxiliary examination and has been considered as a Rheumatologist's stethoscope. Each type of CIA has several unique ultrasonographic features, allowing the clinicians to early diagnosis and treatment. The aim of this paper is to describe the clinical utility of the musculoskeletal ultrasound and ultrasonographic findings in patients with CIA.