3.1 MSK Normal anatomy Flashcards
Why is ultrasounds beneficial for MSK
Can see tendons in motion
Is MSK better than MRI and CT?
It can be. Very operator dependent, can exceed MRI and CT
What are Tendons? (4)
- Bundles of collagen fibers
- Attach muscle to bone
- Facilitate flexion and extension
- Poor /Weak blood supply = poor healing. must be surgically repaired.
What is the point of attachments that are raised ridges on the bones?
tuberosities
Tendons in Long Axis appearance
Fibrillar pattern
hyperechoic strands interspersed with hypoechoic CT
Tendons in Short Axis appearance
Hyperechoic finely punctate foci
hypoechoic CT
round, oval or flattened shape.
Tendon echogenicity is highly dependent on?
Angle of insonation
Angles >__degrees off perpendicular may demonstrate a loss of ____?
> 10; echogenicity
What is the off angle artifact called?
ANISOTROPY
Maybe mistaken for pathology or tears
It is vital when scanning a tendon that the beam be?
PERPENDICULAR TO TENDON
The tendon has a ____ shape so you may need to change the probe position/or have pt move to straighten tendon to avoid this artifact.
Curved
What are 2 types of fibrous sheaths?
- Synovial
2. Paratenon/Peritenon
What does a Synovial sheath do?
wrap around tendon to decrease friction
and secrete fluid for motion
What does Paratenon/Peritenon do?
loose CT that surrounds Achilles and patellar tendon
What are flattened synovial lined pouch /sacs called?
Bursa
What does the Bursa produce?
Synovial fluid
Where are the Bursa located?
High friction points
What does the Bursa look like sonographically?
Hypoechoic flattened structure
Normal Bursa are Difficult to see on US.
(often only see if inflamed or excess fluid collection)
Nerves in LONG axis have what appearance?
“Railroad” hypoechoic nerve fibers divided by hyperechoic CT
Nerves in SHORT axis have what appearance?
“Honeycomb” circular nerve fibers (holes) surrounded by hyperechoic CT (web)
many nerves are too small to see. wrist you can see some
What do ligament attach?
bone to bone
remember tendons attach Muscle to bone
What is the purpose of ligaments and what are they composed of?
Stability and strength of joints
Collagen
What is the sonographic appearance of ligamnets?
similar to tendon but HARDER to visualize due to smaller size and location
What does bone look like sonographically?
Hyperechoic line with alot of shadowing
US is not good to assess bone we see more of the ______ of the bone
Cortical (superficial) surface
Cartilage is a____ ____ in the body?
Shock absorber
____Cartilage lies at the terminal ends of bones
Hyaline
On US the Cartilage appears as (4)
Hypoechoic
well defined
smooth
Non-compressible (with Transducer pressure)
The muscle we see when performing MSK US is ?
Skeletal striated muscle
Skeletal striated muscle can?
Extract and extend