Doppler Waveform Analysis

Question 1

What is the purpose of a Doppler waveform analysis

Answer 1

Help confirm diagnosis/ APPROXIMATE location and SEVERITY of arterial occlusive disease

Question 2

A downfall with Doppler waveform analysis is that we cannot discriminate _____ from an occlusion

Answer 2

A stenosis

Question 3

What position does the patient need to be in for a Doppler analysis and why

Answer 3

Supine, to keep extremities at the same level as the heart decreasing influence from hydrostatic pressure

Question 4

Along with the patient being supine for Doppler tests, what other positions should be considered

Answer 4

Knees slightly bent to help externally rotate the hips
Prone
RLD/LLD

Question 5

Which physical principle relates to the waveform being reflected from a MOVING TARGET (blood), the frequency of that wave RECEIVED is different from the TRANSMITTED wave

Answer 5

The Doppler effect

Question 6

Explain the Doppler shift

Answer 6

FREQUENCY of the wave RECEIVED is different from the TRANSMITTED wave

Question 7

Two piezoelectric crystals: one constantly sending ultrasound, one constantly receiving reflected waves
This describes what?

Answer 7

Continuous wave Doppler (CW)

Question 8

With CW Doppler, the reflected frequency is higher or lower than the transmitted frequency depending on _____

Answer 8

Direction of flow

Question 9

This type of Doppler velocimetry employs a ZERO CROSSING frequency meter displaying the signals on a strip chart recorder

Answer 9

Analog

Question 10

Which frequency (high or low) has more oscillations

Answer 10

HIGH frequency has MANY

LOW frequency has only a FEW

Question 11

T/F

Analog (zero crossing frequency meter) ESTIMATES the frequency that is displayed on screen?

Answer 11

True

But has acceptable accuracy

Question 12

What are two drawbacks for analog (zero crossing frequency meter)

Answer 12

Noise

Less sensitive

Question 13

This type of Doppler velocimetry uses individual frequency a displayed by FAST FOURIER TRANSFORM (FFT) method

Answer 13

Spectral analysis

Question 14

Is analog Doppler velocimetry more commonly used for duplex evaluation or is spectral analysis?

Answer 14

Spectral analysis

Question 15

Related to spectral analysis:
The horizontal axis (X) displays _____
The vertical axis (Y) displays ______

Time/frequency shift

Answer 15

X axis = time

Y axis = frequency shift

Question 16

What MHz probe range is recommended for Doppler analysis

Answer 16

8-10 MHz

Question 17

Which upper extremity velocities are recorded

Answer 17

Subclavian
Axillary
Brachial (@antecubital fossa)
Radial
Ulnar

Question 18

Which lower extremity velocities are recorded

Answer 18

Common femoral (CFA)
Superficial Femoral (SFA)
Popliteal
Posterior tibial (PTA) / medial malleolus
Dorsalis pedis (DPA)
Peroneal / lateral malleolus (if necessary)

Question 19

The AUDIBLE and WAVE FORM qualities are observed , documented and combined with what Doppler technicque

Answer 19

Doppler segmental pressures

Question 20

Potential sources of technical error with Doppler analysis include
(5)

Answer 20

Incorrect probe position
Incorrect angle of incidence
Inadequate amount of gel
Excessive pressure on the probe tip
Insufficient period of rest before testing

Question 21

Describe a normal triphasic signal: upper and lower extremities
(5)

Answer 21

Rapid upstroke
Sharp peak
Rapid downstroke
Flow reversal 
Resumption of foward flow

Question 22

Describe an ABNORMAL biphasic signal (5)

Biphasic can be considered normal in some patients

Answer 22

Rapid upslope
Sharp peak
fairly rapid down stroke
Flow reversal 
No resumption of foward flow

Question 23

Describe the ABNORMAL monophasic signal (4)

Answer 23

Slow upslope
Rounded peak
Slow downstroke
No reversal

Question 24

A monophasic/pulsatile signal is often obtained _______ to a stenosis

Answer 24

Proximal

**distal or well collateralized occlusions may also be monophasic but less pulsatile

Question 25

Vaso__________ of the ______ vessels often occur with proximal obstruction, reducing the PULSATILITY.
This makes the signal have lower resistance (steady)flow quality

Answer 25

VasoDILATATION of the DISTAL

Question 26

Describe two charectoristics of arterial flow in the subclavian

Answer 26

High resistant

Multiphasic flow

Question 27

A ______ occlusion or critical stenosis will cause the subclavian artery to become monophasic

Answer 27

Proximal

Question 28

T/F

Waveforms found in the hand can be quite variable

Answer 28

TRUE

Question 29

With a relaxed and warm patient, the brach,radial, and ulnar arteries have what kind of resistance

Answer 29

Lower resistance

Question 30

Analog Doppler is not capable of portraying velocities less than_____ cm/sec

Answer 30

Less than 6 cm/sec

Question 31

What is the “string sign” during a Doppler analysis

Answer 31

When there is an absent Doppler signal

• this is suggestive of occlusion or pre-occlusion vessels

Question 32

The disease when blood is flowing into the lower extremities is called ________, however, the blood that is going out into the extremities is call ______

Answer 32

INFLOW: blood flowing into lower extremities… EX= aorta-iliac disease

OUTFLOW: blood flowing out into lower extremities…. EX= femoral-popliteal disease

Inflow—> CFA —-> outflow

Question 33

By dividing the peak-to-peak frequency difference (P1 - P2) by the mean (average) frequency we will get the ________ index.

Answer 33

Pulsatility index (PI)

Question 34

What would proximal arterial obstruction to do the acceleration time on Doppler waveform

Answer 34

Would cause a slowing of the time interval between the onset of systole to the point of maximum peak

Question 35

What does an acceleration time of greater than 133 m/sec suggest?

Answer 35

That would suggest a proximal arterial disease

Rounded peak on waveform