Doppler

Question 1

Doppler shift is ___ related to the velocity of blood cells

directly
indirectly
not related

Answer 1

directly

Question 2

Doppler shift is directly related to the ___ of the transmitted sound

period
speed
velocity
frequency

Answer 2

frequency

Question 3

If the transducer’s frequency doubles the Doppler shift will ?

remain the same
double
halve

Answer 3

double

Question 4

In Doppler if we have a 90 degree to the vessel the image will be black with a ___doppler shift

10
100
180
0

Answer 4

0

Question 5

Is defined by a magnitude and a direction

speed
velocity
distance
direction

Answer 5

velocity

Question 6

Is purely a magnitude, indcates the distance that a red blood cell moves in one sec

velocity
speed
amplitude

Answer 6

speed

Question 7

Is this the doppler equation?
2x velocity of blood x tx freq x transducer freq x cos/prop speed
YES
NO
No answer text provided.

Answer 7

NO

Question 8

Measured velocity = true velocity x ____

cosine 0
speed
harmonics
frequency

Answer 8

cosine 0

Question 9

Motion between the sound source and the receiver creates a __ change

power
frequency
intensity
pressure

Answer 9

frequency

Question 10

Negative shift is when the sound is moving ___ the transducer

away
toward
no change

Answer 10

away

Question 11

Positive shift is when the blood is moving ___ transducer

toward
away
no change

Answer 11

toward

Question 12

Reflected freq- transmitted freq =

Doppler shift
Doppler positive
negative doppler

Answer 12

Doppler shift

Question 13

T or F: Doppler shifts are created when transmitted sound wave strike moving red blood cells.

T
F

Answer 13

T

Question 14

T or F: The slower the velocity the greater the Doppler frequency
T

F

Answer 14

F

Question 15

T or F: You have to turn on the Doppler equation for it to work?
You Answered
T

F

Answer 15

F

Question 16

The ___ axis of a Doppler spectrum represents time?

X
Y
Z
M
No answer text provided.

Answer 16

X

Question 17

The % of the true velocity that is measured depends on the _____ of the angle between the sound beam and direction of motion

2
velocity
cosine
speed

Answer 17

cosine

Question 18

The ___ axis represents Doppler shift or velocity
X
Y
Z
M

Answer 18

Y

Question 19

The process of extracting the low Doppler freq from the transducers carrier frequency is called?
compression
compensating
demodulation
amplification

Answer 19

demodulation

Question 19

The motorcyle approaches and the sound gets louder. What is this called?
negative doppler shift
positive doppler shift
neutral shift

Answer 19

positive doppler shift

Question 20

The reflected frequency is ___ than the tranasmitted frequency to create positive shift

higher
lower
same

Answer 20

higher

Question 21

Units for speed?

cm2
Length
cm/per sec
distance

Answer 21

cm/per sec

Question 22

What changes when the sound source and the reveiver move closer together or farther apart?

power
intensity
harmonics
frequency

Answer 22

frequency

Question 23

What does the 2 in the Doppler equation represent?

two different frequency
two doppler shifts
two different images produced

Answer 23

two doppler shifts

Question 24

What is another name for Doppler shift? Doppler Dan Doppler harmonics Doppler frequency

Answer 24

Doppler frequency

Question 25

What is the standard cosine angle we use in clinical practice? We use this number since we cannot achieve 0 or 180? 0 50 60 75

Answer 25

60

Question 26

When an angle exists between the direction of flow and the sound beam, the measured velocity is ___ than the true velocity? less more same entire

Answer 26

less

Question 27

Which of the below does Doppler frequency indicate? velocity speed amplitude distance

Answer 27

velocity

Question 28

When the velocity is halved, the Doppler shift is ? doubled halved remains the same

Answer 28

halved

Question 29

When the blood cells are moving parallel to the sound beam, the _____ velocity is measured? 10% 50% 100% 150%

Answer 29

100%