kremkau chapter 5 assessment

A change in frequency caused by motion of a source or reflector defines ________.

Select one:

a. Doppler effect

b. spectral analysis

c. Poiseuille's equation

d. Doppler shift

a.

A Doppler shift at 60 degrees is ________ what it would be at 0 degrees.

Select one:

a. two thirds of

b. one half of

c. three times

d. twice

b.

A nonsteady flow with acceleration and deceleration over the cardiac cycle, is called ________.

Select one:

a. laminar flow

b. pulsatile flow

c. parabolic flow

d. plug flow

b.

Continuous-wave Doppler shifts are detected within the ________.

Select one:

a. region of the transmitting beam

b. overlapped region of the transmitting and receiving beams

c. near zone length

d. range gate

b.

Determining the direction of the Doppler shift voltages is accomplished by the ________.

Select one:

a. spectrum analyzer

b. phase quadrature detector

c. autocorrelation

d. fast Fourier transform

b.

Doppler measurements are not reliable at Doppler angles greater than________ degrees.

Select one:

a. 40

b. 60

c. 30

d. 50

b.

Doppler shift is not proportional to ________.

Select one:

a. operating frequency

b. flow direction

c. flow speed

d. cosine of the Doppler angle

b.

Echoes arrive from the sample volume depth at a rate equal to ________.

Select one:

a. one quarter of the pulse repetition frequency

b. twice the pulse repetition frequency

c. the pulse repetition frequency

d. one half of the pulse repetition frequency

c.

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

Select one:

a. higher the operating frequency

b. lower the speed of the scatterer

c. less the Doppler shift

d. more accurate the Doppler information

c.

Gases, nutrients and waste products are exchanged through the walls of ________.

Select one:

a. venules

b. arterioles

c. capillaries

d. arteries

c.

If pressure differences in a straight vessel increase, the flow rate ________.

Select one:

a. changes direction

b. does not change

c. decreases

d. increases

d.

Motion toward the transducer demonstrates ________.

Select one:

a. flow below the baseline

b. an antegrade flow pattern

c. a positive Doppler shift

d. spectral broadening

c.

Poise is a unit given for ________.

Select one:

a. viscosity

b. velocity

c. pressure

d. density

a.

Poiseuille's equation states that, if the flow rate increases, the ________.

Select one:

a. pressure difference has decreased

b. viscosity of the fluid has increased

c. tube length has increased

d. tube diameter has increased

d.

Resistance of the blood flow depends on the radius of the ________.

Select one:

a. tube

b. tube to the fourth power

c. tube squared

d. tube divided by the length of the tube

b.

Resistance to flow offered by a fluid in motion describes ________.

Select one:

a. volumetric flow rate

b. velocity

c. viscosity

d. pressure

c.

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

Select one:

a. 40

b. 30

c. 60

d. 50

b.

Spectral broadening may be produced by ________.

Select one:

a. low flow velocities

b. low Doppler gain settings

c. beam spreading in arrays

d. high wall filter settings

c.

The amount of blood passing a point per unit of time defines ________.

Select one:

a. resistance

b. viscosity

c. volumetric flow rate

d. velocity

c.

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

Select one:

a. Spectral

b. Duplex

c. Color

d. Power

d.

The decreased pressure in regions of high flow speed is called ________.

Select one:

a. Bernoulli effect

b. continuity rule

c. Poiseuille's law

d. volumetric flow rate

a.

The difference between the emitted frequency and the echo frequency returning from a moving scatterer is called ________.

Select one:

a. Doppler effect

b. continuity rule

c. Bernoulli effect

d. Doppler shift

d.

The Doppler equation relates the Doppler shift to the ________.

Select one:

a. pressure and resistance

b. flow speed and resistance

c. flow speed and pressure

d. flow speed and frequency

d.

The fast Fourier transform derives the Doppler ________.

Select one:

a. color scale

b. spectrum

c. power display

d. variance maps

b.

The horizontal presentation in the spectral display represents ________.

Select one:

a. imaging depth

b. acceleration time

c. velocity

d. time

d.

The maximum normal flow speed in the circulation is ________ cm/s.

Select one:

a. 100

b. 75

c. 80

d. 125

a.

The normal adult circulatory system contains ________ liters of blood.

Select one:

a. 4

b. 3

c. 5

d. 6

c.

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

Select one:

a. capillaries

b. arterioles

c. flow rate

d. blood flow

b.

The state of the downstream arterioles is reflected in the ________.

Select one:

a. arterial peak systole

b. venous flow rate during inspiration

c. venous flow rate during expiration

d. arterial diastolic flow

d.

The volumetric flow rate is equal to ________.

Select one:

a. force per unit area

b. resistance of blood flow multiplied by the flow rate

c. pressure difference multiplied by the resistance

d. average flow rate across the vessel multiplied by the cross-sectional area of the vessel

d.

The width of the sample volume is determined by the ________.

Select one:

a. beam width and sample volume depth

b. number of focal zones utilized and maximum penetration depth

c. thickness of the element and sample volume depth

d. operating frequency and maximum penetration depth

a.

Turbulent flow is a form of ________ flow.

Select one:

a. parabolic

b. continuous

c. pulsatile

d. nonlaminar

d.

Variance color maps demonstrate a change of hues from ________.

Select one:

a. right to left

b. top to bottom

c. left to right

d. bottom to top

c.

Vertical thickening of the spectral tracing is called ________.

Select one:

a. Doppler effect

b. range ambiguity

c. turbulence

d. spectral broadening

d.

What advantage does spectral analysis have when compared to other Doppler techniques? Spectral analysis ________.

Select one:

a. determines flow direction

b. is free of aliasing artifact

c. displays peak systolic velocities

d. is not angle dependent

c.

What is required for flow to occur?

Select one:

a. Hydrostatic pressure

b. Constant driving pressure

c. Variable driving pressure

d. Pressure difference

d.

What is the driving force behind blood flow?

Select one:

a. Flow rate

b. Pressure

c. Heart

d. Gravity

b.

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

Select one:

a. Laminar

b. Disturbed

c. Helical

d. Plug

a.

Which flow type demonstrates a flow velocity that is essentially constant across the vessel?

Select one:

a. Laminar

b. Parabolic

c. Plug

d. Helical

c.

Which matter is considered a fluid?

Select one:

a. Solids

b. Gases and liquids

c. Gases

d. Liquids

Feedback

b.

Which of the following Doppler displays cannot determine flow direction?

Select one:

a. Continuous wave

b. Power

c. Color

d. Spectrum

b.

Which of the following Doppler techniques must be time shared?

Select one:

a. Spectral analysis

b. Color Doppler

c. Continuous wave

d. Duplex imaging

d.

Which of the following is an advantage of pulsed Doppler?

Select one:

a. Higher operating frequencies can be utilized.

b. Higher frequency shifts can be displayed without aliasing.

c. Depth of sample volume can be accurately selected.

d. Sensitivity of low flow velocities is increased.

c.

Which of the following pulsed Doppler techniques is the most likely to demonstrate slow flow velocities in deep vessels?

Select one:

a. Duplex imaging

b. Spectral analysis

c. Power Doppler

d. Color Doppler

c.

Which system control eliminates low-frequency Doppler shifts?

Select one:

a. Angle correction

b. Wall filter

c. Dynamic range

d. Range gate

b.

Which type of blood flow demonstrates a chaotic flow pattern?

Select one:

a. Disturbed

b. Turbulent

c. Parabolic

d. Stenotic

b.

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

Select one:

a. Plug

b. Laminar

c. Parabolic

d. Disturbed

a.

With color Doppler imaging, the priority control ________.

Select one:

a. selects which gray-scale echo strength will demonstrate color

b. filters out low-intensity echoes

c. eliminates aliasing

d. selects the pulse repetition frequency

a.

________ are the tiniest vessels in the human body.

Select one:

a. Veins

b. Capillaries

c. Venules

d. Arterioles

b.

________ describes the volumetric flow rate as a constant.

Select one:

a. Continuity rule

b. Poiseuille's law

c. Doppler equation

d. Bernoulli effect

a.

A decrease in pressure in regions of high flow speed is called the Poiseuille's effect.

A. True

B. False

b.

According to Poiseuille's equation, if the radius of the tube increases, flow rate increases.

A. True

B. False

a.

As flow energy increases, pressure energy increases.

A. True

B. False

b.

Blood flows from the left and right ventricles into the aorta and pulmonary artery, respectively.

A. True

B. False

a.

Color Doppler displays utilize high frame rates.

A. True

B. False

b.

Disturbed flow is a form of laminar flow.

A. True

B. False

a.

Flow conditions downstream can be reflected in the spectral analysis slightly upstream.

A. True

B. False

a.

Higher operating frequencies produce larger Doppler shifts.

A. True

B. False

a.

If the flow speed increases, the pressure decreases.

A. True

B. False

a.

If the length of the tube increases, the flow rate also increases.

A. True

B. False

b.

If the pressure difference between two points increases, the flow rate also increases.

A. True

b. false

a.

If the source frequency increases, the Doppler shift increases.

A. True

B. False

a.

If viscosity increases, flow rate increases.

A. True

B. False

b.

In a stenosis, flow speed increases and pressure decreases.

A. True

B. False

a.

In pulsed Doppler imaging, the operator of the ultrasound system controls the length and location of the sample volume.

A. True

B. False

a.

Increased flow speed through a stenosis can cause distal turbulence.

A. True

B. False

a.

Poiseuille's law deals with a long straight vessel without stenosis.

A. True

B. False

a.

Power Doppler shifts are determined by the speed of the moving scatterers.

A. True

B. False

b.

Pulsatile flow is uncommon in arterial circulation.

A. True

B. False

b.

The Doppler shift is directly related to volumetric flow rate, not the flow speed.

A. True

B. False

b.

The Doppler shift is proportional to the blood flow speed.

A. True

B. False

a.

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

A. True

B. False

a.

The variation in colors in different locations is caused by the changing Doppler angle.

A. True

B. False

a.

The vertical axis of a spectral display represents the various frequency shifts.

A. True

B. False

a.

Volumetric flow rate is proportional to flow resistance.

A. True

B. False

b.