Musculoskeletal ultrasound is a musculoskeletal imaging technique that adds a different and complementary dimension of imaging evaluation to the traditional modalities of plain radiography, computerized tomography (CT), and magnetic resonance imaging (MRI).
Advantages
Recognized advantages of musculoskeletal ultrasound include:
ready availability of ultrasound equipment
relatively low cost of the procedure compared with advanced imaging such as CT and MRI
no ionizing radiation
ability to image patients with a contraindication to MRI (e.g. some types of pacemakers)
much less artifact when imaging patients with surgical hardware compared to CT and MRI
ability to perform a dynamic evaluation, improving the radiologic interpretation of the clinical relevance of findings seen in a static image (e.g. shoulder impingement)
Standard high-frequency ultrasound probes also have the ability to resolve finer imaging detail compared to MRI. The axial resolution of a 10 MHz probe is 150 μm. A 1.5 T MRI scanner with a field of view of 12 x 6 cm and a matrix of 256 x 256 pixels, with a slice thickness of 0.5 cm, has a resolution of 469 x 469 μm 1.
Disadvantages
Despite its many strengths, musculoskeletal ultrasound also has some limitations in the complete evaluation of musculoskeletal disorders.
radiography and CT provide a much better evaluation of mineralization and the spatial relationship of fractures
MRI is superior to assess bone marrow, bone tumors, joints, and muscles that are inaccessible to high-resolution ultrasound probes (e.g. the spine, sacroiliac joints, cruciate ligaments, etc.)
Musculoskeletal ultrasound also encounters its own set of artifacts, such as anisotropy, and requires a solid knowledge base and background in ultrasound technique for safe and accurate results.