Hemodynamics Flashcards
What is doppler shift?
difference between transmitted and received frequency
What type doppler sys provides motion info as a function of depth? Why?
Pulsed wave doppler
bc you can adjust sample volume
To elim aliasing in spectral doppler adjust…
Baseline, PRF, Doppler transmit freq
NOT USE Wall filter
Color Doppler measures…
AVG freq data
Doppler Effect
change reflected freq caused by reflector motion in relation to transducer
Normal color doppler display
Bart
Rabt
3 BF char that can be eval with color doppler
existence of bf
direction
quality or turbulence
Type of doppler instrumentation is color doppler derived from?
Multi-gated PW Doppler
Power doppler is angle dependent T/F
T
Types of doppler devices
Continuous Wave
Pulsed Wave
Color Doppler
Has highest output intensity
Pulsed doppler w/ duplex
Upper power limit SPTA (spatial peak temporal avg) for continuous wave instruments?
500mw/cm2
milliwatts
Continuous Wave Doppler
frequency shift info
no depth info!!!!
How many piezoelectric crystals does CW doppler transducer use?
2
1 transmits, 1 receives
Multiple subsets
1 subset transmits, 1 receives
Is propagation speed the same for PW and CW doppler in same medium?
Yes
