Ultrasound imaging for the rheumatologist V. Ultrasonography of the ankle and foot.

Ultrasonography (US) is a useful tool for imaging, which can be used for the assessment of joints and periarticular structures in all rheumatological disorders. In patients with pain and/or swelling of the ankle and foot, US provides information about the presence of joint effusion, synovitis, tenosynovitis, tendinosis, and tendons tears, helping in the differential diagnosis between joint or tendon/enthesis involvement. Moreover, US allows clinicians to monitor and guide needle positioning to inject pharmaceutical substances more safely and effectively even in hard-to-reach sites. US represents an accurate, safe and low-cost technique that can be used for the examination of the ankle and foot in rheumatic disorders.