MSK Ultrasound Flashcards
What doe MSK ultrasound evaluate?
Dynamic evaluation of tendons
Is MSK ultrasound more accurate from MRI and CT?
In some cases
What are the composition of tendons?
Bundles of collagen fibres
What does Tendons attach?
Muscle to bone (tuberosities)
What does the tendons facilitate in terms of motion?
Flexion and extension
How is experience is for MSK?
Very
How is the blood supply for tendons?
Poor
What does tendons look like in long axis?
- Linear band of hyperechoic strands
- Fibrillar pattern: interspersed with hypoechoic connective tissue
What does tendons looks like in short axis?
- Hyperechoic finely punctuate foci
- Hypoechoic connective tissue
- Round, oval or flattened shape
Tendon echogenicity is highly dependent on what?
Angle of insonation
What is anisotrophy?
Angles greater than 10 degrees off perpendicular may demonstrate a loss of echogenicity
Anisotropy may be mistaken for what sometimes?
Pathology
In terms MSK the beam must like how in relation to tendons?
Perpendicular
What happens if we have a curved shape of tendon?
Change probe position/ straighten tendon
What does a and be demonstrate?
Patellar tendon in long axis and short axis
What does these two images demonstrate?
Achilles tendon in long axis and short axis
What does synovial sheaths do?
- Wraps around tendon to decrease friction
- Secretes fluid
What is the paratenon/ peritenon sheaths?
Loose connective tissue
What are examples of Paratenon/ peritenon?
Achilles and patellar tendon
What are bursas?
Flattened synovial lined pouch/sac
What does bursas produce?
Synovial fluid
Where are bursas located?
High friction points
What does Bursas look like on u/s?
Hypoechoic flattened structure
How easy is it to identify bursas on U/S?
Difficult
What does these images demonstrate?
Pre-patellar bursas
What does this image demonstrate?
Patellar Synovial sheaths in long and short axis
What does these images demonstrate?
Achilles synovial sheath in long and short axis
What is the sonographic appearance of nerves in long axis?
- Railroad appearance
- Hypoechoic nerve fibres divided by hyperechoic connective tissue
What does nerves look like in short axis?
- Honeycomb pattern
- Circular nerve fibres surrounded by hypoechoic connective tissue
What do Ligaments attach?
Bone to bone
What does ligaments help us do?
Stability and strength
What is the composition of ligaments?
Collagen
What is the sonographic appearance of ligaments?
Similar to tendon but more difficult to visualize
What does this image demonstrate?
Nerve fibres in short and long axis
honeycomb pattern and railroad pattern
Can we assess bone?
Limited
The bone has what type of surface?
Cortical (superficial)
What does this image demonstrate?
ligaments, note how similar to tendons they look like.
What does bone look like sonographically?
Hyperechoic line with strong posterior shadowing
What is cartilage?
Shocker absorbers
Where does hyaline cartilage lie?
Terminal ends of bonds
What does cartilage look like on U/S?
- Hypoechoic
- Well defined
- Smooth
- Non-compressible
What does this image demonstrate?
Cartilage in the knee
What does muscles look like u/s?
- Skeletal striated muscle
- Hypoechoic tissue with hyperechoic fibres
What can muscles do?
Contract and extend
What does this image demonstrate?
Muscles
What type of resolution do we need for the shoulder?
High resolution linear array
How should the patient sit for shoulder examination?
Patient sitting on a rotating stool
The rotator cuff has 4 tendons, what are they?
- Subscapularis
- Supraspinatus
- Infraspinatus
- Teres minor
Label the image
What kind of movement does bicep tendons do?
Flexor and extenders
Where is the bicep tendon located?
- Bicipital groove between the greater and lessor tuberosity
- Anterior to humerus
What is the technique for scanning the biceps tendon? SAX and LAX
- Arm neutral elbow bent at 90 degrees
- SAX: document proximal tendon, check position in groove
- LAX: Document proximally and more distally
Label the image
Label the image
Where does the subscapularis attach?
- From underside of scapula
- Attaches to the lesser tuberosity
How do we scan a subscapularis tendon?
- Arm in a external rotation
- Probe will be transverse on patient, LAX on tendon
- One image at caracoid, one at insertion
- Perform a dynamic assessment
Label the image
What type of movement can the supraspinatus do?
Abduction of humerus/ stabilizer
Where is the supraspinatus located?
- Superior to humeral head
- Attaches to greater tuberosity
What incident do we usually see at the supraspinatus?
Torn tendon of the rotator cuff
What kind of technique can we use to scan the supraspinatus?
- Arm hyperextended and internally rotated
- Image in LAX and SAX
Label the image
What does the infraspinatus do?
- External rotator of HH
- Abductor of humerus
Where does the infraspinatus sit?
- Lateral and posterior to shoulder
- Extends from Scapula to GT
What is the technique for imaging of the infrapinatous?
- Patient places area across chest
- Imaged in LAX only
Where does the teres minor attach?
Inserts on GT
What does the teres minor move?
Adductor of the humerus
Label the image
Label the image
What forms the Quadriceps tendon?
Tendons from all four quads join to form
When the quadriceps tendon look like when the leg is extended?
Tendon concave
How should the leg present for scanning?
The leg needs to be scanned
What planes do we scan the quad tendon?
LAX and SAX
How does the quad tendon look like in SAX?
Oval
Label the image
Where does the patellar tendon extend from?
Apex of patella to tibial tuberosity
What is the measurements of the patellar tendon?
- 5-6 cm length
- 2- 2.5 cm wide
- 4-5 mm AP
What planes can we scan the patellar tendon?
LAX and SAX
What is the most commonly imaged tendon of the ankle?
Achilles tendon
What is the Achilles tendon a fusion of?
Of the aponeuroses of the sole us and gastrocnemius muscles
What does the Achilles tendon insert into?
The posterior surface of the calcaneus
How do we scan the Achilles tendon?
- Prone position
- Foot hands off the end of the table
- Patient can dorsiflex to straighten tendon
What is the typical measurement of the Achilles?
- 1.2 - 1.5 cm wide
- 0.5 - 0.7 cm AP
What is kager’s fatty triangle?
Area of variable echogenicity anterior to distal half of tendon
In terms of the hands and wrist what is the most common pathology?
Outside trauma, overuse/ compression
What is the most common entrapment syndrome of the wrist and hand?
Carpal tunnel
What is the carpal tunnel?
Space between the carpal bones and ligament
What is included inside the carpal tunnel joint?
- Tendons
- Median nerve
- Muscles
- Vessels
Where does the median nerve pass through?
The carpal tunnel
How does the median nerve course?
Anterior to the flexor tendon of the second finger
What is the scanning technique for the median nerve?
- Scanned in transverse
- Forearm resting on a flat surface
- Wrist in supination
What is the landmarks of the median nerve?
Ulnar artery- medial landmark
What does this image demonstrate?
The Achilles tendon scanned in long axis then proximal, medial and distal in short axis
What is the sonographic appearance of the median nerve?
- Median nerve hypoechoic
- Tendons are echogenic
- Honeycomb appearance
Label the image of the wrist
What are some pathology that we may see in the wrist?
- Tears
- Inflammation
- Ganglion cysts
- Popliteal/ bakers cysts
- Carpal tunnel syndrome
- Tumours
- Foreign bodies
What are factors that contribute to a tendon tear?
- Age
- Calcification
- Corticosteroids
- Systemic diseases
What are the two types of tears?
Complete and incomplete
What does tears look like sonographically?
- Hypoechoic defects
- Focal thinning
- Architectural distortion
- Fluid filled defects
- Echogenic deposits if chronic
- Possible non visualization
What kind of tears will we see with rotator cuffs?
- Complete
- Small incomplete
- Associated
What does a complete rotator cuff tear look like?
Cartilage interface sign
thin hyperechoic line at interface between normally hypoechoic cartilage and abnormally hypoechoic tendon
Where does a the rotator cuff sit with a complete rotator cuff tear?
Deltoid sits directly on the humeral head
What does a small incomplete rotator cuff look like?
Rim tent
What is a associated tear look like?
- Joint effusion
- Irregularity of bony surface
What sign is associated with the rotator cuff?
Geyser sign
What does these images demonstrate?
Rotator cuff tears
What causes inflammation?
- Tendonitis
- Sport or work related
- Diffuse or focal involvement
- Edema
- Possible calcifications
What should we do to confirm tendon thickening?
Compare to the contralateral side if possible
What does tendon thickening look like sonographically?
- Decreased echogenicity (watch technique)
- III margins
- Hyperemia
- Possible calcifications
What does this image demonstrate?
Tendinitis
What is peritendinitis?
- Inflammation to peritendon
- Achilles
What is tenosynovitis?
Inflammation of tendon sheath
What is bursitis?
Sonolucent collection with ill-defined walls
What causes bursitis?
Due to trauma or microtrauma
What is this an example of?
Bursitis
What are ganglion cysts?
Benign soft tissue tumors
Where are ganglion cysts usually found?
- Hand/ wrist
- Typically in the hand/wrist
- In any joint or tendon sheath
What does ganglion cysts present as?
- Palpable mass
- focal pain
What is the sonographic appearance of ganglion cysts?
- Cystic mass attached to tendon sheath
- Oval fluid collection with enhancement
- May contain debris
- Chronic cysts may have a hypoechoic, solid appearance
What does this image demonstrate?
Ganglion cyst
What is another name for a popliteal cyst?
Baker’s cyst
Where is a popliteal cyst?
- Synovial cyst of the knee
- dilated gastrocnemiosemimembranous bursa
Where is popliteal cyst located?
Posteromedial
What is popliteal cysts associated with?
Rheumatoid arthritis
Are popliteal cysts asymptomatic?
They are asymptomatic and symptomatic
What can popliteal cysts mimic?
Can mimic Thrombophlebitis or DVT
Can the popliteal cyst rupture?
Potential to
What does this image demonstrate?
Baker’s cyst
What is carpel tunnel syndrome?
- Encroachment of median nerve
- Decrease in size of tunnel
- Increase in volume within the space
What do patients with carpel tunnel syndrome feel?
Pins and needles
What is not generally a imaging diagnosis for carpel tunnel?
CTS
What are some imaging signs for carpel tunnel?
- A nerve that is 3x greater in one axis than another axis at 90 degrees
- Loss of honeycomb appearance
- Sudden increase or decrease in contour
- Increase in cross sectional area when compared to unaffected side
What does this image demonstrate?
Carpal tunnel syndrome
(comparison of the circumference of one carpal tunnel to the other)
What are giant cell tumors?
Benign tumor of the tendon sheath
What does giant cell tumors look like sonographically?
- Hypoechoic masses
- Lobulated contours
What are osteochondromas?
Benign cartilaginous tumor
How can osteochondromas develop?
Can develop in a popliteal cyst
What does osteochondroma’s look like sonographically?
Hyperechoic area with posterior shadow
What are lipomas?
- Adipose tissue
- Compressible, mobile, painless
What does lipomas look like sonographically?
Often hypoechoic by depends on surrounding tissue
What are foreign bodies?
ID nonradio-opaque FB’s or localization of radio-opaque FB’s
How can foreign bodies be examined?
Soft tissue can be examined for secondary inflammatory changes
What does the metal of foreign bodies look like?
- Hyperechoic
- Comet tail
What does this image demonstrate?
A foreign object (IUD?)