Chapter 8 -Doppler Waveform Analysis Flashcards
Continuous wave Doppler uses how many piezo-electric crystals?
2
With CW Doppler, you are able to both hear and see waveforms. True or False?
Think ABIs
yes.
Its when were doing ABIS, were able to both hear the waveform and also see it.
Pertaining to Continuous wave Doppler, the qualitative data includes only the FFT and not the analog waveform.
REMEMBER: Analog is like ABis
FFT is showing the actual waveform.
True or False
False. Contains both
Describe the characteristics of what a normal multiphasic/triphasic waveform would look like
Rapid systolic upstroke sharp peak rapid mid systolic downstroke late systolic flow reversel forward diastolic.
Describe the characteristics of what an ABNORMAL biphasic waveform looks like? What is different than normal?
This can also be considered normal
Rapid systolic upstroke and sharp peak is the same.
Slower downstroke of systolic flow
There is a late systolic flow reversal like seen in normal
NO FORWARD diastolic flow.
Describe the abnormal characteristics of monophasic flow. When scanning, monophasic flow should indicate disease
Delayed systolic upstroke
rounded peak (not sharp peak like normal)
No flow reversal
Slowed mid systolic down-stroke
In what instance, could you see a normal/near normal signal even when there is occlusions or stenosis?
If there is well collateralization
If you see a waveform that has a more rounded appearance, what would you suspect?
looks almost like venous flow…
an occlusion with poor collateralization.
How is the pulsatility index calculated? what are they measuring?
you’re basically measuring peak to peak. So peak of the systolic to peak of the diastolic. Usually the computer will calculate this for you.
When calculating the PI (pulsatility index) what is considered normal and abnormal?
Normal is GREATER than for 4.0
Abnormal is LESS than 4.0 (60% stenosis proximal to sample)
What is the acceleration time (AT) calculated for?
to see if there’s a delay in the systolic upstroke. If there is, this could indicate proximal obstruction.
What is considered normal and abnormal in “Acceleration Time”
Normal is LESS THAN 133 milliseconds
Abnormal is MORE than 133 milliseconds (proximal obstruction)
If you see an acceleration time of 180 milliseconds in common femoral artery, what should you suspect?
Proximal obstruction in the iliacs.. that is an abnormal AT.
If there is an occlusion in blood flowing into the lower extremities is considered _______ disease.
For example an occlusion in the iliacs
inflow or outflow?
inflow
An occlusion in an artery that the blood is flowing out of the extremity is considered ___ disease?
For example, an occlusion in the femoral/popliteal
Inflow or outflow?
outflow.
Post-exercise-
If we see a waveform that appears to have a slower upstroke and a rounded peak and no reverse component than it did before exercise, what could that indicate?
that is abnormal, there is likely an obstruction.
The subclavian, axillary and brachial arteries have more (high or low?) resistant flow patterns?
high resistant
q
Waveforms at the wrist tend to be more variable. Which would we see more often?
high or low resistant?
Low resistant.
