Physics 2 Quiz 3 (Doppler)

Question 1

Which mode provides precise information regarding the variation in velocities present at a selected location in the field?

Answer 1

Pulsed Doppler with spectral analysis

Question 2

What is the Doppler angle?

Answer 2

Flow direction relative to the ultrasound beam

Question 3

Spectral broadening will cause which change in a spectral analysis tracing?

Answer 3

Vertical thickening

Question 4

When frequency is reduced, what happens to the Doppler shift frequency from a moving tissue?

Answer 4

It decreases

Question 5

When imaging w color flow Doppler where the pulse repitition frequency is 12 kHz, aliasing would first become apparent once the Doppler shift becomes greater than:

Answer 5

6 kHz

Question 6

In diagnostic ultrasound, what does the Fast Fourier Transform (FFT) do?

Answer 6

Separate the frequency components of a Doppler shift signal

Question 7

Continuous wave Doppler…

Answer 7

Simultaneously transmits and receives ultrasound

Question 8

Term that relates to the intensity of a color Doppler image:

Answer 8

Luminance

Question 9

In general, a Doppler frequency shift could result from all of the following EXCEPT:

—a stationary sound source and a stationary listener
—a moving sound source and a stationary listener
—a moving sound source and a moving listener
—a stationary sound source and a moving listener

Answer 9

—a stationary sound source and a stationary listener

Question 10

T/F

The intensity of the returning Doppler shift echoes are affected by the flow speed

Answer 10

False

Question 11

***Written

What is the Doppler shift frequency i you had an initial frequency of a 4 MHz and received frequency of 4.05 MHz

Answer 11

50 kHz

Question 12

To precisely obtain the velocity of the carotid artery, the ______________ ______________ must be accurately incorporated

Answer 12

Doppler angle

Question 13

T/F

Power Doppler does not rely on the velocity of the reflector and is not angle dependent

Answer 13

True

Question 14

The Doppler equation relates the Doppler shift to the:

Answer 14

Flow speed, frequency, and Doppler angle

Question 15

Color can change in a vessel due to:

Answer 15

Vessel contour, increase in flow speed, change in Doppler angle

Question 16

Color Doppler…

Answer 16

-demonstrates flow direction
-demonstrates flow characteristics
-angle dependence
-demonstrates mean Doppler shift

Question 17

What is (are) required in a color Doppler signal processor?

Answer 17

-Detecting whether the shift is positive or negative
-Using autocorrelation
-Ability to detect Doppler shift

(All are required)

Question 18

A color Doppler display of red signifies:

Answer 18

Doppler shifts that depend on the map chosen

Question 19

Color map baselines are represented by:

Answer 19

Black

Question 20

A wall filter might…

Answer 20

Eliminate high-intensity Doppler shifts

Question 21

T/F

Pulsed wave and color Doppler combined with gray-scale sonography is called duplex scanning

Answer 21

False

Question 22

When compared to gray-scale frame rates, color-flow frame rates are:

Answer 22

Lower

Question 23

What processing technique can cause pixilation ?

Answer 23

Read zoom

Question 24

T/F

Aliasing happens with spectral Doppler but not color Doppler

Answer 24

False

Question 25

There are multiple adjustments that need to made to the image below. List the primary adjustment that needs to be made for each of the following: —grey scale image —spectral analysis —color Doppler Do not list more than one thing for each mode. Only the frst statement will be read.

Answer 25

grey scale - decrease the depth spectral analysis - decrease the PRF color Doppler - angle vessel in the direction of the color box and Doppler angle

Question 26

Power Doppler imaging is a good choice when you want to:

Answer 26

Show minute perfusion

Question 27

Which of the following represents the greatest frequency shift? 1.2 kHZ -2.1 kHz 0.002 MHz -3,200 Hz -0.003 MHz

Answer 27

-3,200 Hz

Question 28

If the angle correct is set at 0º but should be 60° and the display indicates a flow speed of 100 cm/s, what would be the correct flow speed?

Answer 28

50 cm/s cosine was 1 but should have been 0.5 multiply velocity by 0.5

Question 29

Decreased distal resistance normally has what effect on end-diastolic flow?

Answer 29

Increase in flow

Question 30

If all the cells in a vessel were moving at the same constant speed, the Doppler spectral trace would be:

Answer 30

A thin horizontal line