Word of the day: Baker Cyst

Examples of Baker Cyst
Variety of sonographic characteristics

Today’s Word of the day is Baker Cyst or popliteal cyst is commonly seen in patients over 50 years of age and occurs when there is a distention of the semimembranosus-medial gastrocnemius bursa.  Baker cyst occurs due to local irritation or inflammation, but most often is associated with fluid accumulation through communication with the knee joint.

A Baker cyst can have a variety of ultrasound characteristics ranging from anechoic to more complex fluid representing hemorrhage or synovial hypertrophy.  Accurate diagnosis of a Baker cyst requires identification of the channel between the semimembranosus and the medial head of the gastrocnemious tendon, which connects the bursa to the knee joint via the subgastrocneumius bursa. This appears as a C-shaped fluid collection that wraps around the medial head of the gastrocnemius tendon and muscle.

To learn more about Baker Cyst, and how to identify it during your evaluations, check out upcoming MSK Hands-On Training Course that will provide hours of hands-on scanning.


Anisotropy is a common artifact seen in musculoskeletal ultrasound that occurs when the ultrasound beam encounters a structure at a non-perpendicular angle.  The artifact results with a loss of echogenicity in structure.  We see anisotropy more commonly in tendons and ligaments, but it also occurs in muscle and nerves to a lesser extent.

To learn more about anisotropy, and how to identify it during your evaluations, check out upcoming educational seminars that will provide hours of hands-on scanning.

Benefits of Implementing Diagnostic Musculoskeletal Ultrasound at Your Practice

A physician sonographer performing musculoskeletal ultrasound of the wrist and forearm

Ultrasound is increasingly being used for musculoskeletal applications. Why is this the case and how can you and your patients benefit from this advancing modality? Read on to find out.

Used by practitioners in sports medicine, PM&R, rheumatology and orthopedics, musculoskeletal ultrasound is primarily used to diagnose pathology in tendons, nerves, muscles, ligaments and joints as well as to guide the needle in real-time during interventional procedures (Smith and Finnoff 64).

Advantages of using MSK Ultrasound Imaging

According to Smith and Finnoff, the advantages of using musculoskeletal ultrasound are:

• High-resolution soft tissue imaging
• Ability to image in real-time
• Facilitates dynamic examination of anatomic structures
• Can interact with the patient while imaging
• Minimally affected by metal artifact (ie, implants and hardware)
• Ability to guide procedures (eg, aspirations, injections)
• Enables rapid contralateral limb examination for comparison
• Portable
• Relatively inexpensive
• Lacks radiation
• No known contraindications

Comparisons of other diagnostic modalities with MSK Ultrasound Imaging

When compared to other modalities, ultrasound is clearly the more appropriate choice. In most instances, when compared to most magnetic resonance imaging (MRI) studies, ultrasound can deliver higher quality images, down to submillimeter detail of MSK parts (Kremkau 428).

In contrast with CT scans and X-rays, Smith and Finnoff state that musculoskeletal ultrasound can image soft tissue at higher resolutions allowing for safe and accurate needle injections and aspirations during interventional procedures. Moreover, the danger of radiation is absent when dealing with patients of child-bearing age (65).

In addition to its interventional uses, the scope in which ultrasound can be used for diagnostic applications is vast. Due to high image clarity as well as patient safety, ultrasound can help practitioners diagnose various forms of pathology including ligament and muscle sprains, joint effusions, tendon tears, tendinosis, and nerve entrapments (65).


Educational Resources for MSK Ultrasound Imaging

Gulfcoast Ultrasound Institute offers a complete line of musculoskeletal ultrasound educational DVDs as well as introductory and advanced hands-on ultrasound courses. We invite you to take advantage of these opportunities in this steadily emerging field.

Works Cited
Smith, Finnoff. “Diagnostic and Interventional Musculoskeletal Ultrasound: Part 1. Fundamentals” Journal of American Academy of Physical Medicine and Rehabilitation 1 (2009):64-75. Print.

Kremkau F. Diagnostic Ultrasound: Principles and Instruments. 6th ed.
Philadelphia, PA: WB Saunders; 2002:428