The aim of this article was to review the current status of ultrasound imaging of patients with rheumatological disorders
of the hands and feet. Ultrasound machines with high-resolution surface probes are readily available in most radiology departments
and can be used to address important clinical questions posed by the rheumatologist and sports and rehabilitation physician.
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 spaced joints, 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. Contrast-enhanced magnetic resonance
provides a better measure of capillary permeability and extracellular fluid than does ultrasound. The ability to image simultaneously
multiple small joints in the hands and feet and their enhancement characteristics cannot be matched with ultrasound, though
future developments in 3-D ultrasound may narrow this gap. Magnetic resonance provides a more uniform and reproducible image
for long-term follow-up studies.
Keywords Ultrasound - Joint - Rheumatoid arthritis - Synovitis