Musculoskeletal ultrasound is a subgroup of diagnostic ultrasound. Iain has been a pioneer in the use of musculoskeletal ultrasound for both diagnosis and guided injection therapy. He has performed over 50,000 therapeutic injections.
Normal Achilles tendon
Musculoskeletal ultrasound is best used to assess specific structures that are suspected to be abnormal or to answer specific clinical questions. For example it is excellent for assessing the rotator cuff or answering a question such as “Is there a tear in the supraspinatus tendon?” It is not ideal when the problem is poorly defined such as “What is the cause of the left arm pain?” It is also limited in assessing deeper structures as ultrasound resolution declines at depth. Ultrasound cannot assess or see through bone. For structures that are close to a skin surface ultrasound has better spatial resolution than any other imaging test or modality.
The value of MSK ultrasound is thus much better done in conjunction with a clinical assessment to define the nature and anatomic site of concern. The images captured in MSK ultrasound are thus operator dependent and the outcome of the scan will depend on the clinical and technical experience of both the doctor and sonographer undertaking and reporting the scan. The reporting doctor (unless physically remote) should always be involved in assessing your problem directly.
Dr Levon Nazarian, a professor of radiology at Thomas Jefferson University published a paper in the American Journal of Roentgenology in June 2008 (Vol. 190:6, pp. 1621-1626) gave 10 reasons why musculoskeletal ultrasound was an important complementary or alternative technique to MRI:
- Everyone can undergo an ultrasound
- Ultrasound can resolve finer details than MRI
- Ultrasound allows real-time dynamic examination
- The ultrasound probe can be placed exactly where it hurts
- Ultrasound can effectively image patients with surgical hardware
- Doppler ultrasound gives important information about the vascularity
- Ultrasound is better than MRI for distinguishing cystic from solid material
- Ultrasound is better for guiding therapeutic interventions
- Ultrasound facilitates bilateral comparison
- Ultrasound has a more flexible field-of-view
Perhaps one of the biggest advantages of MSK ultrasound is its use to help guide targeted injections. Ultrasound guided injections of corticosteroid and other substances directly into or around various structures can provide excellent symptomatic relief. Click here for more information about ultrasound guided injections and for further ultrasound topics see ULTRASOUND NEWS and RESEARCH.