[Diagnostic ultrasound of the small joints of the hands and feet: current status and role of ultrasound in early arthritis].

The small joints of the hands and feet play a central role in the diagnosis and classification of arthropathy. Ultrasound can be used to assess involvement in areas that are clinically occult. The aim of this article was to review the current status of ultrasound imaging of patients with rheumatological disorders of the hands and feet. There is increasing evidence that ultrasound detects synovitis that is silent to clinical examination. Detection and classification of synovitis and the early detection of bone erosions are important in clinical decision making. Ultrasound has many advantages over other imaging techniques with which it is compared, particularly magnetic resonance. The ability to carry out a rapid assessment of many widely spacedjoints, coupled with clinical correlation, the ability to move and stress musculoskeletal structures and the use of ultrasound to guide therapy accurately are principal amongst these. The use of colour flow Doppler studies provides a measure of neovascularisation within the synovial lining of joints and tendons, and within tendons themselves, that is not available with other imaging techniques. Disadvantages compared to MRI include small field of view, poor image presentation, and difficulty in demonstrating cartilage and deep joints in their entirety.