Ultrasound Imaging Flashcards
what is the focal zone
narrowest zone along long axis
longitudinal sonogram
long axis of transfucer aligned to long axis of structure
transverse sonogram
transducer applied across structure
the field of view is the same as what
the long axis of transducer
the extended field of view -
displays frames acquired sequentially
normal cortical bone
hyperechoic, smooth, continuous
normal tendons/ligaments
hyperechoic, distinct parallel fiber pattern
normal muscle
hypoechoic w/ parallel fibrous hyperechoic bands
normal bursa
thin hypoechoic line
normal hyaline cartilage
hypoechoic layer next to cortex
normal nerve
hyperechoic, relative to muscle (honeycomb)
normal cysts
anechoic
with doppler ultrasound, blood velocity measured on the differnce of when moving toward the transducer -
sound waves reflect off of blood cells arrive at transducer faster
with doppler ultrasound, blood velocity measured on the differnce of when moving away from the transducer -
sound waves reflect off of blood cells arrive at transducer slower
doppler ultrasound provides information on
presence of blood flow
direction of blood flow
gross circulation abnormalities
advantages of USI
low cost and portable
no contraindications
ability to visualize structures not limited by orthogonal planes
continuous modification of imaging based on findings
real time assessment can be performed while imaging
advantage of USI over MRI for muscles
architecture
imaging while testing resistance
advantage of USI over MRI for tendons
fiber structure
degenerative changes
longitudinal tears
advantage of USI over MRI for ligaments
fiber structures
ability to stress test while imaging
advantage of USI over MRI for cysts/bursae
septations
debris not seen on MRI
disadvantages of USI for joints/intra-articular structures
limited ability to show joint surfaces & intra-articular surfaces
disadvantages of USI for bones
can only show cortical outline
disadvantages of USI for scanning across lung fields
ultrasound does not cross air/tissue interfaces
USI limitations
limited field of view
incomplete eval of bones
limited penetration
user error
cost
variable quality
obses pts have poorer visualization
MSK USI common clinical application
tendinopathies
muscle strains
shoulder pain – RTC, bicep tendon lesion, bursae swelling, subacromial impingement
superficial jt assessment
post-op assessment
joint stability w/ dynamic testing
peripheral nerve compression
inflammatory arthropathies
superficial disruption of bone cortices
