Kahoot - All Post Midterm Flashcards

1
Q

The reflected frequency is higher than the transmitted frequency when there is a positive shift or

A

Source and receiver are moving towards each other

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2
Q

Doppler angle is between

A

Flow direction and sound beam

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3
Q

What is related to Doppler shift

A

Cosine angle between flow and sound beam
Velocity of RBC
Fundamental frequency

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4
Q

True or false

The larger the Doppler angle the larger the Doppler shift

A

False

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5
Q

True or false

The larger the operating frequency the larger the Doppler shift

A

True

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6
Q

True or false

The lower the operating frequency used the faster the calculated velocity

A

False

Check formula relationship

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7
Q

True or false

Incorporating angle with non-zero interrogations always brings the speed up

A

True

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8
Q

Speed of blood

A

10-100 cm/s

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9
Q

Doppler angle best range

A

30-60

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10
Q

Operating frequency range in MHz

A

2-10 MHz

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11
Q

Doppler shift range

A

100 Hz to 11 KHz

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12
Q

True or false

You can hear the Doppler shift

A

True

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13
Q

Number of cycles in a pulse in Doppler u/s

A

5-30

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14
Q

Without angle correct Fd= 16 KHz, what is the shift if you use angle correct at 60 degrees?

A

8 kHz

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15
Q

Why scanning at Doppler angle more than 60 degrees not a good idea?

A

Increases chance of error in velocity

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16
Q

Which is a digital processing technique used to process colour Doppler

A

Autocorrelation

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17
Q

Which one has the higher duty factor? Pulse US or CW Doppler ?

A

CW (no listening time)

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18
Q

No colour in vessel most likely due to

A

No Doppler shift

Doppler angle 90 degrees

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19
Q

PD in Doppler is higher than in B mode, which means typically period (T) in Doppler pulse is higher than in b mode
True or false

A

False

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20
Q

Power Doppler shows blood flow ____

A

Presence

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21
Q

Ensemble length for Doppler u/s

A

3-32

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22
Q

Large ensemble length leads to (3). What does it not do

A
  • better accuracy of Doppler shifts
  • degradation of temporal resolution
  • better sensitivity/detecting echoes
    DOES NOT increase imaging depth
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23
Q

To show faster speeds you need to ______

A

Increase PRF

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24
Q

If your PRF is 10 KHz which Doppler shift will create aliasing

A

1/2 PRF so anything above 5 KHz

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25
Q
Which of these parameters you can’t control in Doppler:
Wall filter 
PRF 
Nyquist limit
Baseline
A

Nyquist limit

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26
Q

This control sets up a cut off amplitude limit below which echoes will show in colour

A

Priority

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27
Q

Which control will eliminate clutter?

A

Wall filter

28
Q

What type of blood flow demonstrates straight layers of fluid sliding over each other

A

Laminar

29
Q

Resistance to flow offered by a fluid in motion describes

A

Viscosity

30
Q

Driving force behind blood flow

A

Pressure difference

31
Q

A nonsteady flow with acceleration and deceleration over the cardiac cycle is ______ flow

A

Pulsatile

32
Q

____ describes volumetric flow rate as a constant

A

Continuity rule
Volumetric flow rate must be constant for the three regions : prox, at and distal to stenosis because blood is neither created or destroyed

33
Q

Volumetric flow rate for a short segment

A

Q=V*A

34
Q

Besides liquids which matter is considered a fluid

A

Gases

35
Q

Turbulent flow is a form of ____ flow

A

Non-laminar

36
Q

The state of downstream arterioles is reflected in the ____

A

Arteriole diastolic flow

37
Q

The Doppler equation relates the Doppler shift to the _____

A

Flow speed and frequency

38
Q

The decreases pressure in regions of high flow speed is called __\\

A

Bernoulli effect

39
Q

For a given flow, the greater the Doppler angle, the

A

Smaller the shift

40
Q

Sound reflects totally at the wall-blood boundary once the Doppler angle is less than

A

30 degrees

41
Q

What is required for flow to occur?

A

Pressure diff

42
Q
Doppler shift does not depend on the :
Speed?
Direction?
Operating frequency?
Doppler angle?

Choose one

A

Flow direction

43
Q

The resistance of the _____ accounts for about one half of the total resistance in the systemic circulation

A

Arterioles

44
Q

The max normal flow speed in the circulation is ____ cm/s

A

100 cm/s

45
Q

Variance colour maps demonstrate a change of hues from

A

Left to right

46
Q

Which of the following Doppler techniques must be time shared?

A

Duplex imaging

47
Q

Which system control eliminates high-intensity low-frequency Doppler shifts

A

Wall filter

48
Q

The width of the sample volume is determined by the ____

A

Beam width

49
Q

What advantage does spectral analysis have when compared to other Doppler techniques

A

Displays peak systolic velocities

50
Q

The angle of incidence is not important with which Doppler display?

A

Power

51
Q

Vertical thickening of the spectral tracing is called

A

Spectral broadening

52
Q

Which type of bf demonstrates a chaotic flow pattern

A

Turbulent

53
Q

Which type of blood flow would demonstrate the narrowest range of Doppler shift frequencies

A

Plug

Because velocity is the same across all blood flow

54
Q

FF Transform

A

Determines Doppler spectrum

55
Q

Can show slow flows in deep or small vessels

A

Power Doppler

56
Q

The horizontal presentation in spectral display represents

A

Time

57
Q

The vertical axis in spectral display represents

A

Doppler shift

Velocity

58
Q

Spectral broadening may be produced by

A

Beam spreading in arrays

59
Q

Continuous wave Doppler shifts are detected within the

A

Overlap area of transmitted and received beams

60
Q

Motion towards the TD demonstrates

A

Flow above baseline

Positive Doppler shift

61
Q

Advantage of pulsed Doppler

A

Depth of sample volume can be accurately selected

62
Q

Echoes arrive from sample volume depth at a rate equal to

A

PRF

63
Q

Poiseuille’s equation states that if the flow rate increases the

A

Tube diameter has increased

64
Q

True or false

The maximum detectable blood flow speed with pulsed Doppler imaging is determined by aliasing

A

True

65
Q

True or false

The Doppler shift is directly related to volumetric flow rate

A

False

66
Q

True or false

Multiple foci are used in colour Doppler imaging

A

False

Also colour Doppler does NOT utilize high frame rates