Chapter 4 - Doppler waveform analysis of extremities

Question 1

Doppler shift

Answer 1

Reflected wave from moving target

Wave received different from wave transmitted

Question 2

Doppler effect

Answer 2

Relative motion between source and receiver of sound

Question 3

Angle of insonation usual range

Answer 3

45-60 degrees

Question 4

Types of doppler velocimetry

Answer 4

Auditory
Analog
Spectral analysis

Question 5

Auditory doppler velocimetry

Answer 5

Just listen to distinguish the waveforms

Question 6

Analog doppler velocimetry

Answer 6

Amplitude of doppler shifted frequencies vs time

Question 7

Drawback of analog doppler velocimetry

Answer 7

1) noise
2) less sensitivity
3) underestimate high velocity
4) overestimate low velocity

Question 8

Spectral analysis

Answer 8

Display frequency/velocity against time

Shows amplitude of backscattered signals at any frequency and time

Question 9

Doppler probe frequency for extremity

Answer 9

8-10 MHz

Question 10

Auditory signals from headset orientation

Answer 10

Right earphone = antegrade flow signal

Left earphone = retrograde flow signal

Question 11

Pulsatility index definition and interpretation

Answer 11

Peak to peak frequency
divided by
mean frequency

higher as it moves away from heart
decreases with disease

Question 12

Factors that give erroneous acceleration time

Answer 12

1) large doppler angle

2) poor cardiac output

Question 13

Define inverse damping factor

Answer 13

Ratio of distal PI to proximal PI

Question 14

Normal value for inverse damping factor

Answer 14

0.9-1.1

<0.9 is disease

Question 15

Transit time definition

Answer 15

Time it takes for systole to reach target

compare two sides simultaneously

Question 16

Normal acceleration time in CFA

Answer 16

< 133 msec

Question 17

normal PI in CFA

Answer 17

> 5.5

Question 18

Normal PI in popliteal

Answer 18

~ 8

Question 19

PI that indicates AIOD in CFA

Answer 19

< 4-5 with patent SFA