doppler final

Question 1

when color gain is set to an inappropriately high level, color appears throughout the color box. A term that describes this is called______________

Answer 1

color confetti

Question 2

Multiple utrasound pulses that are used to accurately determine blood velocities are called ___________

Answer 2

ensemble

Question 3

A wall filter is used to eliminate high frequency Doppler shifts from moving anatomy rather than from moving blood cells. TorF

Answer 3

False

Question 4

The 3 basic forms of blood flow are:

Answer 4

pulsatile, phasic, and steady

Question 5

The Reynolds number for turbulent flow is greater than 2,000. TorF

Answer 5

True

Question 6

Which technique is used to perform spectral analysis on color Doppler data?

Answer 6

autocorrelation

Question 7

Velocity mode distinguishes laminar flow from turbulent flow. TorF

Answer 7

False

Question 8

What are the 2 things that are correct about pulsed Doppler transducers?

Answer 8

at least 1 crystal and lower sensitivity

Question 9

The _____________ frequency is the highest Doppler frequency that can be measured without the appearance of aliasing

Answer 9

Nyquist

Question 10

What is the most common error with Doppler ultrasound?

Answer 10

Aliasing

Question 11

The Law of Conservation of Energy states that the pressure is lowest at _________

Answer 11

the stenosis

Question 12

The phasic and steady flow are present in venous circulation. TorF

Answer 12

True

Question 13

Simultaneous anatomic imaging and Doppler is called

Answer 13

duplex imaging

Question 14

Doppler shift is inversely related to the frequency of the transmitted sound. TorF

Answer 14

False

Question 15

When the blood cells are moving __________ to the sound beam, the entire velocity is measured.

Answer 15

parallel

Question 16

Turbulent flow profiles may be seen _______ from a significant stenosis in a vessel.

Answer 16

downstream

Question 17

Flow increases when either

a. pressure gradient increases and resistance decreases
b. resistance increases
c. pressure gradient decreases

Answer 17

a.

Question 18

Assume that a doppler study is performed and the Doppler shift is 6kHz when the blood’s velocity is 2m/s. If the blood velocity slows to 1m/s. What will the Doppler shift be?

Answer 18

3kHz

Question 19

_____________ is defined by a magnitude and a direction.

Answer 19

velocity

Question 20

This process extracts the low Doppler frequency form the transducers carrier frequency.

Answer 20

demodulation

Question 21

The lumen of a horizontal vessel evaluated with a color doppler, sector shaped image contains a single color. TorF

Answer 21

False

Question 22

If a patient is supine what is the arterial pressure at the knee?

Answer 22

140mmHg

Question 23

Tissue vibration associated with turbulence is called a

Answer 23

thrill

Question 24

Transducer frequencies of ___________ Doppler shifts range are used since they are audible

Answer 24

20Hz-20,000Hz

Question 25

Cosine 0 degrees is 1 indicating flow _____________ the transducer, whereas cosine 180 degrees is -1 indicating flow __________ from the transducer.

Answer 25

toward, away

Question 26

All of the following occur during expiration except a. venous flow in the legs increases b. the diaphragm rises into the thoracic cavity c. venous return to the heart decreases d. abdominal pressure increases

Answer 26

d. abdominal pressure increases

Question 27

What is the hydrostatic pressure of the waist if the person is standing?

Answer 27

50 mmHg

Question 28

Blood moving from regions of higher energy to lower energy is called what

Answer 28

energy gradient

Question 29

Velocity mode color Doppler and variance mode color Doppler will produce identical images when blood flow patterns are turbulent. TorF

Answer 29

False

Question 30

Velocity mode color Doppler and variance mode color doppler will produce identical images when blood flow patterns are laminar. TorF

Answer 30

True

Question 31

Absence of color on a color Doppler image always indicates a region of no blood flow. TorF

Answer 31

False

Question 32

During a pulsed Doppler exam, aliasing is observed. Al of the following may eliminate aliasing except. a. selection of another imaging view with a shallower sample volume b. selection of another transducer with a lower frequency c. selection of another imaging view that provides a greater pulse repetition period d. use of a continuous wave system

Answer 32

C.

Question 33

The highest Doppler frequency without the appearance of aliasing is called the ___________ and is equal to ________.

Answer 33

Nyquist limit, half of the emitted PRF

Question 34

The higher the pulse repetition frequency of a doppler exam, the more likely aliasing is to occur. TorF

Answer 34

False

Question 35

What happens to venous flow in the legs during inspiration?

Answer 35

decreases

Question 36

The Reynolds number for laminar flow is less than a. 1500 b. 1200 c. 1000

Answer 36

a 1500

Question 37

__________ in a fluid system is called voltage. Similarly, _________ in a fluid system is called a current.

Answer 37

pressure, flow

Question 38

What is the arterial pressure measured at the patients knee who is standing and the hydrostatic blood pressure is 140 mmHg?

Answer 38

c. 215mmHg (140+75)

Question 39

During expiration, the diaphragm moves UP or DOWN

Answer 39

UP

Question 40

Gravitational energy is a form of ____________ energy

Answer 40

stored

Question 41

___________ energy loss in blood is determined by the hematocrit.

Answer 41

viscous

Question 42

Parabolic flow is the velocity in the center of the lumen and gradually decreases to its minimum at the vessel wall. TorF

Answer 42

True

Question 43

An advantage of power mode doppler is

Answer 43

unaffected by doppler angles

Question 44

Ghosting artifact show up only on spectral doppler. TorF

Answer 44

False

Question 45

Color Doppler will have crosstalk as an artifact. TorF

Answer 45

False

Question 46

Wall filters are used to eliminate low frequency Doppler shifts from moving anatomy. TorF

Answer 46

True

Question 47

What is the current method of processing Doppler signals that can distinguish laminar and turbulent flow?

Answer 47

FFT

Question 48

Which of the following terms is synonymous with spectral broadening?

Answer 48

turbulent flow

Question 49

Supine means that your are ____________

Answer 49

laying flat on your back

Question 50

Stenosis will have increased velocity within the stenosis. TorF

Answer 50

True