Musculoskeletal Ultrasound Flashcards
MSK US definition
Use of high frequency sound waves to image soft tissues and bony structures for the purposes of diagnosing pathology or guiding real-time interventional procedures
Echogenicity
- Hyperechoic – more reflection, sound back to machine (brighter) – i.e. bone
- Hypoechoic – less reflection (darker)
Doppler detects _______
flow/vascularity
Long and short axis
- Long-axis – parallel
- Short axis - perpendicular (cross section)
•Acoustic impedance
•Resistance to sound waves (water highly impedent)
The deeper US goes ________
the lesser the resolution (Details)
Muscle is ___________ (echoic)
hypoechoic background (muscle fasciles) w/ hyperechoic strands (septae)
Nerve (echoic)
•Hypoechoic parallel lines (fascicles) separated by hyperechoic bands
Ligament (echoic)
hyperechoic
Tendon (Echoic)
hyperechoic
Advantages of MSK US
- Superior soft-tissue resolution to MR in many cases
- Real-time imaging / dynamic studies
- Image not degraded by metal
- Readily available
- Patient friendly, radiation-free
Disadvantages of MSK US
- Limited field of view
- Limited penetration
- Incomplete evaluation of bone and intra-articular structures
- Lack of competency and oversight
- Operator dependent
To get deeper, use __________
lower frequency, curved probe
To get superficial details, use ___________
Higher frequency, straight probe
Anisotropy
Artifact - need to be perpendicular or get darkening