Physics Final Review Chapter 1-7

In perpendicular incidence, what is the intensity reflection coefficient for impedances of 45 and 55 rayls?

0.01

What is the spatial pulse length of a four-cycle pulse with a wavelength of 0.1 mm?

0.4 mm

The wavelength of 3.5MHZ ultrasound in soft tissue is__mm a. 0.44 b. 510 c. 4.6 d. 5.1

0.44

For pulses traveling through soft tissue in which the frequency is 5 MHz and there are 3 cycles per pulse, the axial resolution is ____ mm. a. 0.92 b. 0.46 c. 7.5 d. 3.75

0.46

The wavelength of 3 MHz ultrasound in soft tissue is ________ mm.

0.51

If the pulse duration is 3 µs and the pulse repetition period is 350 µs, the duty factor would be ________ %.

0.8

1000 Hz is equal to ________ kHz.

1

What is the SPL in soft tissue for a 4 cycle pulse using a frequency of 6.0 MHZ a. 2.4 mm b. 0.6 mm c. 1.0 mm d. 8.0 mm

1.0mm

Which of the following frequencies is operated by the thinnest element?

10.0 MHz -Thinner elements operate at higher frequencies.

Continuous wave (CW) Doppler has a duty factor of ________ %.

100

If an amplifier has a gain of 15 dB, the ratio of output voltage amplitude to input voltage amplitude is _____. a. 10,000 b. 100 c. 40 d. none of the above

100

What is the maximum penetration depth with a frame rate of 35 frames per second and a line density of 100 lines per frame and using two foci a. 24 cm b. 11 cm c. 11 mm d. 24 mm

11 cm

If a 4 MHZ pulse containing 3 cycles generates an echo that returns 156us after a pulse was emitted by a transducer, at what depth is the structure that produced the echo located a. 8.0 cm b. 8.0 mm c. 12.0 cm d. 12.0 mm

12.0 cm

For each centimeter of distance, the pulse round-trip travel time is equal to ________.

13 µs

If the propagation speed of the transducer element material is 6 mm/us, the operating frequency for a thickness of 0.2 mm is__MHz.

15 -Frequency (MHz)= Propagation speed of the element (mm/us) 2 x thickness of the element (mm)

The distance to a reflector in soft tissue is 15 cm. What is the round-trip time to this depth?

195 µs

The useful frequency range for most diagnostic applications is__MHz.

2-15 -The useful frequency range for most diagnostic applications is 2 to 15 MHz. Frequencies up to 50 MHz are used in ophthalmologic, dermatologic, and intravascular imaging.

If the wavelength is 0.5 mm, the spatial pulse length for a 4 cycle pulse is ________.

2.0 mm

What is the pulse duration of a four-cycle pulse in a period of 0.5 µs?

2.0 µs

What is the attenuation coefficient for a 5.0 MHz transducer in soft tissue?

2.5 dB/cm

One watt is __ dB below 100 W. a. 20 b. 100 c. 7 d. 40

20

What is the attenuation of a 7.5 MHz transducer at a depth of 20 mm?

7.5 dB

Without compensation, the ultrasound transducer would cause about__of the emitted intensity to be reflected at the skin boundary.

80% -Without compensation, the ultrasound transducer would cause about 80% of the emitted intensity to be reflected at the transducer-skin boundary.

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.

Gain is the ratio of ____. a. amplifier output to input electric power b. voltage ratio squared or voltage ratio to the second power c. amplifier input to output voltage power d. transmission output to amplifier input

A.

Higher operating frequencies produce larger doppler shifts a. true b. false

A.

If a 5 kHz Doppler shift corresponds to 100 cm/s, then a 10 kHz shift corresponds to ____ cm/s a. 200 b. 100 c. 50 d. 250

A.

If a 5 kHz Doppler shift corresponds to 100 cm/s, then a 2.5 kHz shift corresponds to ____ cm/s a. 50 b. 200 c. 10 d. 25

A.

If the pressure difference between two points increases, the flow rate also increases a. true b. false

A.

In a stenosis, flow speed increases and pressure decreases a. true b. false

A.

Resistance of the blood flow depends on the radius of the ... a. tube to the fourth power b. tube divided by the length of the tube c. tube d. tube squared

A.

Shortening the pulses in diagnostic ultrasound broadens the _____. a. bandwidth b. duty factor c. lateral resolution d. pulse duration

A.

The... and ... determine the maximum imaging depth a. attenuation, maximum amplifier gain b. operating frequency, propagation speed c. minimum amplifier gain, attenuation d. transducer element, propagation speed

A.

Turbulent flow is a form of .... flow a. nonlaminar b. pulsatile c. parabolic d. continuous

A.

Ultrasound systems use a mathematical technique called __ to create color flow imaging from doppler frequency shifts a. autocorrelation b. phase quadrature detection c. detection or demodulation d. coded excitation

A.

Vertical thickening of the spectral tracing is called ______. a. spectral broadening b. turbulence c. doppler effect d. range ambiguity

A.

Volumetric flow rate is proportional to the pressure difference a. true b. false

A.

What is required for flow to occur? a. pressure difference b. hydrostatic pressure c. variable driving pressure d. constant driving presssure

A.

What is the period of a 10.0MHZ transducer in soft tissue a. 0.1 usec b. 0.02 us c. 5.0 us d. 0.2 msec

A.

Which type of blood flow demonstrates a chaotic flow pattern a. turbulent b. parabolic c. stenotic d. disturbed

A.

which system control eliminates low- frequency doppler shifts a. wall filters b. angle correction c. dynamic range d. range gate

A.

Which of the following relates to heating?

Absorption

________ is the dominant factor contributing to attenuation of ultrasound in soft tissue.

Absorption

Which of the following determines the beam width at the focus?

Aperture, focal length, and wavelength -The aperture, focal length, and wavelength determines the beam width at the focus.

A decrease in pressure in regions of high flow speed is called a poiseuilles effect a. true b. false

B.

If viscosity increases, flow rate increases a. true b. false

B.

Resistance to flow offered by a fluid in motion describes... a. volumetric flow rate b. pressure c. viscosity d. velocity

C.

Spectral broadening may be produced by ______. a. high wall filter settings b. low flow velocities c. beam spreading in arrays d. low doppler gain settings

C.

The __ is used to detect and measure __ direction in vessels. a. pulsed wave, resistance b. continuity principle, velocity c. doppler effect, flow d. none of the above

C.

The fast Fourier transform derives the Doppler.. a. power display b. variance maps c. spectrum d. color scale

C.

To flow is to move in a ___? a. direction b. container c. stream d. reversal

C.

What is the driving force behind blood flow a. gravity b. heart c. pressure d. flow rate

C.

What is the maximum FR that a machine can display while imaging at a 15 cm depth, with 200 LPF, and a 3 color packets in the ensemble a. 8.56 MHZ b. 25. 67 c. 8.56 Hz d. I do not know

C.

The liquid suspensions that have been developed can be injected into the circulation intravenously to increase ________.

Echogenicity

The Doppler effect is caused by a difference in the depth of two moving objects.

False

Which of the following is achieved within the Fresnel zone?

Focusing of the sound beam -Focusing can be achieved only in the near zone of the beam.

________ is the amount of complete cycles per second.

Frequency

________ are the even and odd multiples of the fundamental frequency

Harmonics

With a linear phased array transducer, the elements measure the width of about__.

One quarter of a wavelength -A linear phased array contains a compact straight line elements, each about one quarter of a wavelength wide.

___ determines how echo data stored in memory appear on the display a. postprocessing b. dynamic range c. color d preprocessing

Postprocessing

The matching layer__.

Reduces reflection of ultrasound at element -The matching layer reduces the reflection of the ultrasound at the transducer element surface, which improves sound transmission across the beam.

In oblique incidence, when the propagation speeds on either side of the boundary are different, which incidence is most likely to occur?

Refracted

Lateral position errors occur on an image due to sound ________.

Refraction

Which artifact displaces structures axially?

Speed error

The proportion of intensity to amplitude is ________.

Squared

With phasing, the reception beam is__and dynamically__.

Steered; Focused -With phasing, the reception beam is steered and dynamically focused.

Beam width can be reduced by focusing to improve lateral resolution.

True -Beam width can be reduced by focusing to improve lateral resolution.

Continuous-wave (CW) transducers have higher efficiencies because energy is not lost to damping material.

True -CW transducers are not damped because pulses are not used. These transducers have higher efficiencies because energy is not lost to damping material.

Axial resolution is often normally better than lateral resolution.

True -Diagnostic ultrasound transducers often have better axial resolution than lateral resolution, but the two may be comparable in the focal region of strongly focused beams.

The linear image consists of__scan lines.

Vertical -The linear image consists of vertical (parallel) scan lines produced by pulses originating at different points across the surface of the array.

The frequency of the _____ determines the frequency of the resulting ultrasound pulse. a. bandwidth b. voltage pulse c. operating frequency d. beam former

Voltage pulse

Electric__applied to a transducer are converted to ultrasound.

Voltages -The electric voltages applied to transducers are converted to ultrasound.

An increase in the number of channels__ a. increases exposure intensity to the patient b. allows more precise control of the beam characteristics c. decreases the control of the beam characteristics d. increases the thickness of the transducer element

allows more precise control of the beam characteristics

As sound travels, the reduction in amplitude and intensity of the wave is called ________.

attenuation

Shadowing and enhancement are descriptions of ________ artifacts.

attenuation

Mirror-image artifact is a form of ________. a. refraction b. reverberation c. speed error d. grating lobes

b

When a pulse is emitted before all the echoes from the previous pulse have been received, which artifact occurs? a. mirror image b. range ambiguity c. slice thickness d. speed error

b

Which of the following artifacts appears as a series of closely spaced discrete echoes distal to a strongly reflective structure? a. Ring down. b. Comet tail. c. Refraction. d. Grating lobes.

b

Which of the following decreases the likelihood of range ambiguity artifacts a. decreasing operating frequency b. decreasing PRF c. decreasing doppler angle d. baseline shift e. increasing pulser output

b

Which of the following types of artifacts can be beneficial? a. Refraction. b. Attenuation. c. Propagation. d. Reverberation.

b

Which type of artifact is most likely to produce a doubling of a single image? a. Reflection. b. Refraction. c. Reverberation. d. Section thickness.

b

propagation speed error results in improper __ position of a reflector on the display a. lateral b. axial

b

Brightness mode is also called _____. a. elastography b. volume imaging c. b color d. b mode/ 2D/ gray scale

b mode/ 2D/ gray scale

Propagation speed is higher in __ than in soft tissue a. water b. lungs c. bone d. fat

bone

Propagation speed is higher in ________ than in soft tissue.

bone

In reverberation, subsequent reflections are ___ than previous ones. a. shallower b. brighter c. weaker d. stronger

c

Increased intensity of echoes in the focal region of the beam is called _______. a. harmonics b. shadowing c. focal banding d. enhancement

c

Multiple reflections between two structures describes a. refraction b. mirror image c. reverberation d. speed error

c

Reflected echoes displaying falsely high amplitudes describe ________. a. speckle b. shadowing c. enhancement d. speed error

c

Shadowing and enhancement are descriptions of ________ artifacts. a. propagation b. refraction c. attenuation d. reverberation

c

The Nyquist limit is ________. a. oversampling of the Doppler shifts b. even and odd multiples of the frequency c. the upper limit to the Doppler shift that can be properly detected d. the number at which turbulence is detected

c

Weakening of echoes distal to a strongly attenuating structure describes ________. a. comet tail b. enhancement c. shadowing d. ring down

c

When Doppler gain is set too high, which artifact is likely to occur? a. aliasing b. range ambiguity c. spectrum mirror image d. location mirror image e. speckle

c

Which of the following is a result of sound refraction? a. Axial duplication of structures. b. Displacement of structures axially. c. Displacement of structures laterally. d. Multiple equally spaced linear reflections.

c

Which of the following would least likely cause acoustic shadowing? a. Gallstone. b. Bowel gas. c. Urinary bladder. d. Uterine fibroid.

c

Which of the following would likely demonstrate acoustic enhancement? a. Liver. b. Pancreas. c. Gallbladder. d. Falciform ligament.

c

the fact that the beam, as it scans through tissue, has some nonzero width perpendicular to the scan plane results in the ______ ______ artifact a. mirror image b. range ambiguity c. slice thickness/ section thickness d. speed error

c

Section thickness artifact is a result of ________. a. interference b. pulse length c. finite speed of sound in soft tissue d. beam width perpendicular to scan plane

d

If frequency increases, each cycle (period) a. decreases b. increases c. remains unchanged d. none of the above

decreases

if a pulse is emitted 65us after the previous one, echoes returning from beyond __cm will produce range ambiguity a. 1 b. 2 c. 3 d. 4 e. 5

e

In oblique incidence, the ________ and ________ angles are always equal.

incidence; reflection

In oblique incidence, the ___ and __ angles are always equal a. normal, transmitted b. incident, transmitted c. incident, reflected d. refracted, reflected

incident, reflected

Frequency ________ wavelength

is inversely proportional to

What does 3 dB of attenuation mean?

one half the original intensity

Impedance is equal to density multiplied by ________.

propagation speed

Pulsed ultrasound consists of ________ separated by ________ of time.

pulses; gaps

Period is the ________ it takes for one ________ to occur

time; cycle

Some artifacts are produced by improper equipment settings. true or false

true

Spatial compounding can reduce attenuation artifacts. true or false

true

The greater the voltage amplitude produced by the amplifier, the greater the intensity of the ultrasound pulse a. true b. false

true

Which of the following is NOT an advantage of harmonic imaging a. elimination of grating lobe artifacts b. wide primary beam c. increased lateral resolution d. reduction in superficial reverberation artifacts

wide primary beam

For perpendicular incidence, the incidence angle is ________.

0

If the propagation speed of the transducer element is 4 mm/us, the thickness required for an operating frequency of 10 MHz is__.

0.2 mm -F (MHz)= Propagation speed of the element (mm/us) 2 x Thickness of the element (mm)

What is the period of a 5.0 MHz transducer in soft tissue?

0.2 µs

The velocity of sound in human soft tissue is assumed to be a constant. If you employ a 7.5 MHz transducer, what is the wavelength of the sound?

0.21 mm

No bioeffects have been observed in mammalian tissues at mechanical index values of less than ________.

0.4

No bioeffects have been observed in mammalian tissues that contained well-defined gas bodies at peak rarefactional pressure values (MPa) of less than ________.

0.4

Duty factors for sonography are typically in the range of ________%.

1

Bioeffects have not been observed in experimental animals with focused intensities below ________.

1 mW/cm2 spatial peak-temporal peak (SPTP)

What is the spatial pulse length in soft tissue for a four-cycle pulse, using a frequency of 5.0 MHz?

1.2 mm

Calculate the pulse duration for a 3.0 MHz transducer in soft tissue with a four-cycle pulse.

1.3 µs

The propagation speed for a round-trip time of 39 µs would be ________ mm.

1.54mm/cm2

The attenuation of a 5.0 MHz transducer at a depth of 4 cm is ________ dB.

10

A two- dimensional image plane is usually divided like a checkerboard in a ___ or similar matrix a. 1540 x 7700 b. 256 x 525 c. 265 x 521 d. 1024 x 768

1024 x 768

The following are all ultrasound frequencies except a. 250 KHZ b. 0.3 MHZ c. 30,000 HZ d. 15 KHZ

15 KHZ

The transducer has an impedance__times that of tissue.

20 -The transducer element has impedance that is about 20 times that of tissue.

20 kHz is equal to ________ Hz.

20,000

In soft tissue, a temperature rise is considered significant once it exceeds ________.

2° C

The distance to the reflector (D) in soft tissue with a round-trip time of 39 µs is _______.

3 cm

An amplifier has a power output of 250mW when the input power .25mW, the amplifier gain __ dB a. 60 b. 30 c. 90 d. none of the above

30

Displays have dynamic ranges up to _____ dB. a. 50 b 100 c. 30 d. 20

30

The following are all ultrasound frequencies

30,000 Hz 250 kHz 0.3 MHz

If an amplifier has a gain of 25 dB, the ratio of output power to input power is _____. a. 18 b. 8 c. 36 d. 320

320

Biological effects have not occurred at temperatures lower than ________.

39° C

If the pulse repetition frequency (PRF) is 6 kHz, which of the following Doppler shifts will cause aliasing?

4 kHz

The even harmonics of 2 MHz are ________ MHz.

4, 6, 8

The PRF in real time imaging typically ranges from .... A. 2-20 MHZ B. 2-15 MHZ C. 4-15 MHZ D. 4.15 KHZ

4-15 kHz

The attenuation of a 5 MHz transducer in soft tissue would be ________ dB at 2 cm of depth.

5

Doppler ultrasound pulses are typically ________ cycles long.

5 - 30

The attenuation coefficient for soft tissue using a 10 MHz transducer is ________.

5 dB/cm

How many potential shades of gray does 9 but memory system have a. 256 b. 512 c. 1024 d. 768

512

At what depth does a 3.0 MHz transducer have an attenuation of 9 dB?

6.0 cm

The maximum frame rate permitted for a 20 cm penetration depth, two foci , and 300 scan lines per frame is__. a. 2.5 b. 8.5 c. 8.0 d. 6.4

6.4

The beam former amplifiers typically have _____ dB of gain. a. 30-100 b. 30-60 c. 60-100 d. 50-100

60-100

What would be the frequency for a 0.22 mm wavelength in soft tissue?

7.0 MHz

How many bits does it take to make a byte a. 15 b. 10 c. 4 d. 8

8

If an echo returns 104 µs after a pulse was emitted by a transducer, at what depth is the structure that produced the echo located?

8.0 cm

A change in frequency caused by motion of a source or reflector defines... a. doppler effects b. spectral analysis c. doppler shift d. poiseuilles equation

A.

A nonsteady flow with acceleration and deceleration over the cardiac cycle is called _____. a. pulsatile flow b. laminar flow c. parabolic flow d. plug flow

A.

According to Poiseuilles equation, if the radius of the tube increases, flow rate increase a. true b. false

A.

As flow resistance decreases, volumetric flow rate _________ a. increase b. no change c. decreases d. doubles

A.

Blood flows from the left and right ventricles into the aorta and pulmonary artery, respectively a. true b. false

A.

Continuous- wave Doppler shifts are detected within the .. a. overlapped region of the transmitting and receiving beams b. near zone length c. range gate d. region of the transmitting beam

A.

Determining the direction of the Doppler shift voltages is accomplished by the _________. a. phase quadrature detector b. spectrum analyzer c. autocorreclation d. fast Fourier transform

A.

Doppler shift is not proportional to... a. flow direction b. cosine of the doppler angle c. flow speed d. operating frequency

A.

Flow is a response to pressure ________ or ______ a. difference, gradient b. increase, decrease c. fore, aft d. presence, absence

A.

For a given flow, the greater the Doppler angle, the _____. a. less the doppler shift b. higher the operating frequency c. lower the speed of the scatterer d. more accurate the doppler information

A.

If pressure differences in a straight vessel increase, the flow rate ______. a. increases b. does not change c. decreases d. change direction

A.

If the flow speed increases, the pressure decreases a. true b. false

A.

If the operating frequency is doubled the doppler shift is doubled a. true b. false

A.

If the pressure is greater at one end of a liquid filled tube or vessel than it is at the other, the liquid will flow from the ___ pressure end to the ____ pressure end a. higher, lower b. lower, higher c. depends on the liquid d. all of the above e. none of the above

A.

If the source/ operating frequency increases, the doppler shift increases a. true b. false

A.

In a stenosis, the pressure is ________ the proximal and distal values. a. less than b. equal to c. greater than d. depends on the fluid e. none of the above

A.

In pulse 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 equation predicts a(n) _____ in flow speed with a increases in vessel radius. a. increases b. decreases c. no change d. not related

A.

Poiseuilles law deals with a long straight vessel without stenosis a. true b. false

A.

The continuity rule predicts a(n) _______ in flow speed with a localized decrease (stenosis) in vessel diameter. a. increase b. decrease

A.

The decreased pressure in regions of high flow speed is called ______. a. Bernoulli effect b. poiseuilles law c. continuity rule d. volumetric flow rate

A.

The doppler equation relates the Doppler shift to the _____. a. flow speed and frequency b. pressure and resistance c. flow speed and pressure d. flow speed and resistance

A.

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 normal adult circulatory system contains _____ liters of blood. a. 5 b. 4 c. 7 d. 3

A.

The variation in colors in different locations is caused by 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.

Which flow type demonstrates a flow velocity that is essentially constant across the vessel? a. plug b. helical c. laminar d. parabolic

A.

Which matter is not considered a fluid? a. solids b. liquids c. gases d. gases and liquids

A.

Which of the following doppler techniques must be time shared a. duplex imaging b. continuous wave c. spectral analysis d. color doppler

A.

Which resolution depends on penetration depth, lines per frame, and the number of focuses? a. temporal b. contrast c. detail d. axil

A.

the Impedance of the matching layer is a. an intermediate value between the transducer element and tissue b. less than the value between the transducer element & tissue c. equal to the impedance of tissue d. greater than the value between the transducer element and tissue

A.

For an operating frequency of 6 MHz, a flow speed of 50 cm/s, and a Doppler shift of 60 degrees, calculate the Doppler shift. a. 1.95 KHZ b. 3.9 KHZ c. 1.95 MHZ d. 3.9 MHZ

A. Doppler Shift = 2 x V x Operating Frequency x cosine / c 2(50)6(.50) / 1.540 = 194.8 = 1.95 kHz

Which of the following is a biological consequence of hyperthermia?

Abdominal wall defects

Which of the following artifacts is exclusive to pulse-Doppler imaging?

Aliasing

To avoid echo misplacement _____. a. a matching layer is added to the transducer element b. penetration depth is increased c. multiple focal zones should be utilized d. all echoes must be received before another pulse is emitted

All echoes must be received before another pulse is emitted

The impedance of the matching layer is__.

An intermediate value between the transducer element and tissue. -The matching layer has impedance of some intermediate value between those of the transducer element and the skin.

Intensity is equal to the power of a wave divided by the ________ over which the power is spread.

Area

Electronic scanning is performed by__transducers.

Array -Electronic scanning is performed with array transducers.

Linear and convex are types of__arrays.

Assembly -Transducer arrays (linear and convex) are transducer assemblies with several transducer elements.

Which of the following types of artifacts can be beneficial?

Attenuation

The primary formats of image presentation are called... a. digital, analog, 3D b. CRT, flat screen, LCD c. b mode, a mode, M mode d. none of the above

B (brightness), M (motion), and A (amplitude);

... Describes the volumetric flow rate as a constant a. Bernoulli effect b. continuity rule c. doppler equation d. poiseuilles law

B.

As flow energy increases, pressure energy increases a. true b. false

B.

As flow velocity increases, pressure increases a. true b. false

B.

Color Doppler displays utilize high frame rates a. true b. false

B.

Doppler ultrasound measures the movement of ... a. bone b. blood c. A & B d. none of the above

B.

Flow resistance decreases with an increase in ___ a. vessel length b. vessel radius c. blood viscosity d. all of the above e. none of the above

B.

For a given flow, the lesser the doppler angle, the ... a. higher the operating frequency b. greater the doppler shift c. more accurate the doppler information d. lower the speed of the scatterer

B.

For an operating frequency of 6 MHZ, a doppler shift of 2.0 KHZ, and a doppler angle of 60 degrees. Calculate the scatterer speed in cm/sec a. 5.13 b. 51.33 c. 513.33 d. 25.67

B.

Gray scale/B- mode/ 2-D is medical anatomic imaging using a .... technique a. starting point b. pulse echo c. vertical parallel d. transducer instrument

B.

If a 8 MHZ ultrasound is reflected from a soft tissue boundary moving at 10m/sec toward the source, the doppler shift is __ MHZ a. .20 b. .10 c. .001 d. 1.0

B.

If frequency increases, each cycle (period)... a. increases b. decreased c. remains unchanged d. none of the above

B.

If the difference in pressure between two points decreases, the flow rate also increases a. true b. false

B.

If the incident or transmitted frequency is 5 MHZ, the propagation speed is 1540m/s and the reflector speed 14m/s toward the source, the doppler shift is__ MHZ a. .045 b. .091 c. .45 d. .91

B.

If the length of the tube increases the flow rate also increases a. true b. false

B.

Increasing the transducer frequency decreases the ____. a. frame rate b. maximum imaging depth c. propagation speed d. detail resolumtion

B.

Multiple foci are used in color doppler imaging a. true b. false

B.

Poiseuille's equation predicts a(n) _____ in flow speed with a decrease in vessel radius. a. increases b. decreases c. no change d. not related

B.

Poiseuille's equation states that, if the flow rate increases, the __________. A. viscosity of the fluid has increased b. tube diameter has increased c. tube length has increased d. both A &B

B.

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.

Stiffer media have ________ sound speeds. a. lower b. higher c. stiffness does not change prop speed d. none of the above

B.

The Characteristics of a fluid that offers resistance to flow is called ___? a. resistance b. viscosity c inertia d. impedance e. density

B.

The angle of incidence is important with all the following doppler displays except a. duplex b. power c. color d. spectral

B.

The difference between the emitted frequency and the echo frequency returning from a moving scatterer is called.. a. Continuity rule b. doppler shift c. doppler effect d. Bernoulli effect

B.

The doppler shift is directly related to volumetric flow rate, not the flow of speed a. true b. false

B.

The doppler shift is the difference between the transmitted and the residual frequencies at a given depth a. true b. false

B.

The horizontal presentation in the spectral display represents a. imaging depth b. time c. velocity d. acceleration time

B.

The maximum normal flow speed in the circulation is _______ cm/s. a. 75 b. 100 c. 80 d. 125

B.

The most correct description below of volumetric flow rate is that it is equal to... a. pressure difference multiplied by the resistance b. average flow rate across the vessel multiplied by the cross section area of the vessel c. resistance of blood flow multiplied by the flow rate d. force per unit area

B.

The volumetric flow rate in a tube is determined by the __ and the __ a. flow speed, doppler angle b. pressure difference, resistance c. blood pressure, heart rate d. size of the wave, curl

B.

Volumetric flow rate is proportional to flow resistance a. true b. false

B.

What is the maximum penetration depth with a frame rate of 30 frames per second and a line density of 120 lines per frame and using 2 foci a. 12.0 cm b. 10.7 cm c. 24.2 mm d. 21.4 cm

B.

When the incident (transmitted) sound direction and the reflector motion are not parallel (non-0 degrees) calculation of the reflected frequency involves the sin of the angle between these direction a. true b. false

B.

When the speed of fluid is constant across a vessel, the flow is called _______ flow a. no flow b. plug c. laminar d. turbulent

B.

Which control can be used to help with clutter? a. gain b. wall filter c. baseline shift d. PRF e. smoothing

B.

Which of the following constitutes a reception channel a. beam former, signal processor, image processor & display b. elements, amplifier, digitizer, delay path c. elements, pulser, signal processor, delay path d. beam former, pulser, amplifier, scan converter

B.

Which of the following doppler displays cannot determine flow direction.. a. color b. power c. continuous wave d. spectrum

B.

Which of the following is an advantage of pulse Doppler? a. higher frequency shifts can be displayed without aliasing b. depth of sample volume can be accurately selected c. higher operating frequencies can be utilized d. sensitivity of low flow velocities is increased

B.

Without compensation, the ultrasound transducer would cause about _________ % of the emitted intensity to be reflected at the skin boundary. a. 10 b. 80 c. 25 d. 50

B.

___ are the smallest vessels in the human body a. veins b. capillaries c. venules d. arterioles

B.

the ultrasound machine directly measures distance a. true b. false

B.

Shortening the pulses in diagnostic ultrasound broadens the__.

Bandwidth -Shortening the pulses broadens the bandwidth.

Lateral resolution is equal to__.

Beam diameter -Lateral resolution is equal to the beam diameter.

Which of the following is not assessed with a tissue-equivalent (TE) phantom?

Beam width

A narrowing of the lumen of a tube is called a ______ a. Bernoulli principle b. continuity principle c. stenosis d. turbulence

C.

A narrowing of the lumen of a tube is called a ______ a. focal zone b. focal point c. stenosis d. near zone length

C.

As flow resistance increases, volumetric flow rate _________ a. increase b. no change c. decreases d. doubles

C.

Doppler Measurements are not reliable at Doppler angles greater than _____ degrees. a. 40 b. 30 c. 60 d. 50

C.

Doppler power imaging indicates (with color) the _____ of flow. a. direction b. character c. presence d. speed

C.

If angle correction is set at 60 degrees but should be zero degrees, the display indicates a flow speed of 150 cm/s. The correct flow speed is __ cm/s. a. 300 b. 150 c. 75 d. 200

C.

If pressure differences in a straight vessel decreases, the flow rate ______. a. increases b. does not change c. decreases d. change direction

C.

Motion toward the transducer demonstrates ______. a. spectral broadening b. flow below the baseline c. a postitive doppler shift d. an antegrade flow pattern

C.

Pressure is ___ a. nondirectional b. unidirectional c. omnidirectional d. all of the above e. none of the above

C.

What type of blood flow demonstrates layers of fluid sliding over each other? a. disturbed b. helical c. laminar d. plug

C.

Which of the following pulsed Doppler techniques is the most likely to demonstrate slow flow velocities in deep vessels a. duplex imaging b. color doppler c. power doppler d. spectral analysis

C.

Which type of blood flow would demonstrate the narrowest range of doppler shift frequencies. a. laminar b. disturbed c. plug d. parabolic

C.

Which of the following artifacts appears as a series of closely spaced discrete echoes distal to a strongly reflective structure?

Comet tail

Aliasing does not occur in ________.

Continuous-wave Doppler

A digitizer__. a. compensates for attenuation b. directs the driving voltages from the pulser c. converts voltage from analog to a digital form d. is responsible for the focusing and steering functions

Converts voltage from analog to digital form

The critical temperature an ultrasound transducer cannot exceed is called the__.

Curie point -If a critical temperature (the Curie point) is exceeded, the element in the transducer loses its piezoelectric properties.

.... flow occurs when a straight parallel streamlines describing the flow are altered a. laminar b. plug c. turbulent d. disturbed

D.

A doppler shift at 60 degrees is _____ what it would be at 0 degrees. a. twice b. three times c. two thirds of d. one half of

D.

An increase in the doppler angle will produce__ flow speeds on the spectral display a. no change b. higher c. not related d. lower

D.

Axial resolution is the.. a. ability to differentiate similar and dissimilar tissue b. ability to differentiate a moment in time c. minimum separation necessary to resolve reflectors perpendicular to the beam direction d. minimum separation necessary to resolve reflectors along the scan ling

D.

Doubling the width of a color box produces a __ frame rate a. doubled b. quadrupled c. unchanged d. halved

D.

Echoes arrive from the sample volume depth at a rate equal to ______. a. one quarter of the PRF b. twice the PRF c. one half of the PRF d. the PRF

D.

Flow increases if ___ increases a. pressure difference b. pressure gradient c. resistance d. a & b e. all of the above

D.

Flow resistance in a vessel depends on___ a. vessel length b. vessel radius c. blood viscosity d all of the above e. none of the above

D.

For an operating frequency of 8.0MHZ, a flow speed of 400cm/sec, and a doppler angle of 60 degrees, calculate the doppler shift in KHZ. a. .0208 b. 31.17 c. 10.35 d. 20.78

D.

Gases, nutrients and waste products are exchanged through the walls of .... a. arterioles b. arteries c. venules d. capillaries

D.

If all the cells in a vessel were moving at the same constant speed, the spectral trace/waveform would be a __ line. a. thick vertical b. thick horizontal c. thin vertical d. thin horizontal

D.

If the incident or transmitted frequency is 5 MHZ, the propagation speed is 1540m/s and the reflector speed 14m/s toward the source, the doppler shift is__ MHZ. What is the reflected/received frequency?? a. .04 MHZ b. 4.5 MHZ c. 50.91 KHZ d. 5.091 MHZ

D.

Increasing the ensemble length__ color sensitivity and accuracy and __ frame rate a. improves, increases b. degrades, increases c. degrades, decreases d. improves, decreases

D.

Lateral resolution is equal to... a. SPL/2 b. operating frequency/2 c. wavelength/2 d. beam diameter

D.

Motion away from the transducer demonstrates... a. spectral broadening b. flow below the baseline c. a postitive doppler shift d. none of the above

D.

Motion of an echo-generating structure causes an echo to have a different ______ from that of the emitted pulse. a. form b. strength c. amplitude d. frequency

D.

Phasing Can ___ a. focus the beam b. improve the image quality c. Steer the beam D. All of the above

D.

Poise is a unit given for _________ a. density b. velocity c. pressure d. viscosity

D.

Poiseuille's equation states that, if the flow rate decreases, the __________. A. viscosity of the fluid has increased b. tube diameter has increased c. tube length has increased d. both A &B

D.

Pressure is _____ per unit area. a. resistance b. viscosity c inertia d. force

D.

Sound reflects totally at the wall-blood boundary once the Doppler angle is less than _______ degrees. a. 50 b. 60 c. 40 d. 30

D.

The PRF in real time imaging typically ranges from .... a. 4-15 MHZ b. 2-15 MHZ c. 2-20 MHZ d. 4-15 KHZ

D.

The amount of blood passing a point per unit of time defines ______. a. viscosity b. resistance c. velocity d. volumetric flow rate

D.

The doppler shift is the difference between __ and __ frequencies a. operating, emitted b. echo, received c. fundamental, harmonic d. received, emitted

D.

The maximum frame rate permitted for a 20 cm penetration depth, two foci, and 300 scan lines per frame is __ a. 3.41 b. 12.86 c. 8.08 d. 6.42

D.

The power ratio is the ratio of a. amplifier input to output voltage power b. transmission output to amplifier input c. pulser output to pulse delay inputs d. voltage ratio squared or voltage ratio to the second power

D.

The resistance of the ... accounts for about one half of the total resistance in the systemic circulation a. flow rate b. blood flow c. capillaries d. arterioles

D.

The state of the downstream arterioles is reflected in the _____. a. venous flow rate during expiration b. arterial peak systole c. venous flow rate during inspiration d. arterial diastolic flow

D.

The width of the sample volume is determined by the ______. a. thickness of the element & sample volume depth b. number of focal zones utilized & maximum penetration depth c. operating frequency & maximum penetration depth d. Beam width and sample volume depth

D.

Turbulent flow is more likely __ to a stenosis a. not to occur b. in the middle c. proximal d. distal

D.

Variance color maps demonstrate a change of hues from ______. a. bottom to top b. top to bottom c. right to left d. left to right

D.

What advantage does spectral analysis have when compared to other Doppler techniques? Spectral analysis... a. is not angle dependent b. is free of aliasing artifacts c. determines flow direction d. displays peak systolic velocities

D.

Which of the following determines the beam width at the focus a. aperture, propagation speed, thickness b. focal length, frequency c. SPL and propagation speed of the element d. aperture, focal length, wavelength

D.

Which of the following determines the beam width at the focus.. a. aperture prop speed and thickness b. focal length and frequency c. SPL & prop speed of the element d. aperture, focal length, wavelength

D.

Which resolution depends on penetration depth, lines per frame, and the number of focuses? a. detail b. contrast c. axial d. temporal

D.

With color Doppler imaging, the priority control ______. a. eliminates aliasing b. filters out low intensity echoes c. selects the pulse repetition frequency d. selects which gray-scale echo strength will demonstrate color

D.

Which of the following is attached to the rear face of the transducer element?

Damping -Damping material is attached to the rear face of the transducer element to reduce the number of cycles to each pulse.

If intensity reflection coefficient increases, intensity transmission coefficient ________.

Decreases

The conversion of echo voltages from the radio frequency to video form is called _____. a. Demodulation / Detection b. pulse inversion c. scan conversion d. analog to digital conversion

Demodulation / Detection

Which resolution relates more directly to transducers?

Detail -Detail resolution relates more directly to transducers. Contrast and temporal resolutions relate more directly to the instrument.

The three aspects to imaging resolution are contrast, temporal, and__resolution.

Detail -The three aspects to imaging resolution are contrast, temporal, and detail (axial and lateral) resolution.

Mirror image is commonly seen around which structure?

Diaphragm

When gain is too high, which of the following occurs? A. contrast resolution is improved. B. week echoes are not imaged. C. Temporal resolution is reduced. D. Differences in echo strength are lost

Differences in echo strength are lost

An analog-to-digital converter is also called a ______. a. signal processor b. summer c. compression d. digitizer

Digitizer

Which of the following is a result of sound refraction?

Displacement of structures laterally

Mirror imaging of a Doppler spectrum is most likely a result of the ________.

Doppler gain being set too high

Added forward flow and flow reversal in diastole can occur with __ flow a. volume b. turbulent c. laminar d. disturbed e. pulsatile

E.

Doppler shift imaging indicated ( with color) the __ of flow a. presence b. direction c. speed d. character e. all of the above

E.

If pressure difference is doubled, volumetric flow rate is _________ a. unchanged b. quartered c. halved d. quadrupled e. doubled

E.

In a single frame, color can change in a vessel because of.. a. vessel curvature b. sector format c. helical flow d. diastolic flow reversal e. all of the above

E.

Volumetric flow rate decreases with an increase in a. pressure difference b. vessel radius c. vessel length d. blood viscosity e. C and D

E.

While stenosis diameter decreases, _____ passes through a maximum a. flow speeds at the stenosis b. flow speed proximal to the stenosis c. volumetric flow rate d. the doppler shift at the stenosis e. A & D

E.

The transducer element converts__to__and vice versa.

Electricity; Ultrasound -The transducer element refers to the piece of piezoelectric material that converts electricity to ultrasound and vice versa.

The purpose of a bandpass filter is to _____. a. filter out the fundamental frequency b. eliminate frequencies outside the echo bandwidth c. eliminate the harmonic frequencies for imaging d. aid in the frequency range of the receiver

Eliminate frequencies outside the echo bandwidth

At a distance of two near-zone lengths, the beam diameter is__the diameter of the transducer element.

Equal to -At double the near-zone length, the beam diameter is equal to the diameter of the transducer element.

A continuous wave (CW) sinusoidal wave is characterized by multiple frequencies.

False

Acoustic speckle is a form of acoustic information in sonographic imaging

False

Aliasing is caused by over-sampling of the Doppler shifts. True or False

False

Attenuation increases with an increase in wavelength.

False

Beam width parallel to the scan plane causes partial volume artifact. True or False

False

Contrast agents produce echoes because the impedance of the suspended particles is similar to the suspending medium.

False

Cycle, period, and frequency are examples of acoustic variables.

False

Doppler test objects and flow phantoms are not able to evaluate gate location. True or False

False

Enhancement weakens the amplitude of structures distally. True or False

False

Grating lobes are essential for the proper operation of a linear phased array transducer. True or False

False

If the depth of penetration is increased, the PRF must be increased. a. true b. false

False

Imaging depth increases with increasing frequency

False

Lateral duplication of a single structure into two separate structures describes mirror imaging artifact. True or False

False

Mirror image artifact is not a factor in color Doppler imaging. True or False

False

Mirror image can occur with only one reflector. True or False?

False

Propagation speed is determined by the fundamental frequency

False

Pulsed ultrasound transducers can generate only ultrasound pulses

False

Sound having a frequency of 10,000 Hz or higher is called ultrasound.

False

Spatial pulse length is determined by the length of the pulse (wavelength) and the propagation speed.

False

Test objects are used by engineers rather than instrument operators. True or False

False

The Nyquist limit is equal to the pulse repetition frequency (PRF). True or false

False

The as low as reasonably achievable (ALARA) principle regulates ultrasound instruments. True or False

False

The average attenuation coefficient for soft tissue is 1.0 dB/cm for each megahertz of frequency.

False

The average propagation speed in soft tissue is 1.54 m/s.

False

The fine texture in soft tissue indicates the excellent resolution that actually exists there. True or false?

False

The spatial peak temporal peak (SPTP) intensity is used in the American Institute of Ultrasound in Medicine (AIUM) statement on mammalian bioeffects. True or False

False

The ultrasound machine directly measures distance.

False

Ceramics used as materials in the production of modern ultrasound transducer elements are naturally piezoelectric.

False -Ceramics are not naturally piezoelectric.

Contrast and temporal resolution relate more directly to the transducer.

False -Contrast and temporal resolution relate more directly to the instrument.

Axial resolution is determined by the width of the ultrasound beam.

False -Detail resolution includes both axial and lateral resolution. Axial resolution is determined by the wavelength and number of cycles in the pulse, whereas lateral resolution is determined by the beam width (diameter).

As sound travels, the width of the beam remains unchanged.

False -Even an unfocused transducer element demonstrates some beam narrowing and is sometimes called the natural focus.

The three aspects of imaging resolution include axial, contrast, and temporal resolution.

False -Imaging resolution has three aspects: detail, contrast, and temporal resolution.

Lateral resolution remains consistent at any depth.

False -Just as beam width varies with distance from the transducer, so too does lateral resolution.

Minimum reflector separation in the direction perpendicular to the beam direction describes axial resolution.

False -Minimum reflector separation in the direction perpendicular to the beam direction producing two separate echoes describes lateral resolution.

Multi-Hertz transducers are driven at only one selectable frequency.

False -Multi-Hertz transducers are driven at one of two or three selectable frequencies by voltage pulses with the selected frequency.

The frequency of a transducer is determined by the diameter and the propagation speed of the element.

False -Operating frequency is determined by the propagation speed and thickness of the element.

Damping material in pulsed transducers increases the spatial pulse length.

False -Pulsed transducers have damping material to shorten the spatial pulse length for acceptable resolution.

The focal length is the distance between equal beam widths that are some multiple of the minimum value at the focus.

False -The focal length is the distance from the transducer to the center of the focal zone. Focal-zone length is the distance between equal beam widths that are a multiple of the minimum value at the focus.

Intensity is uniform throughout the beam.

False -The intensity is not uniform throughout the sound beam.

The matching layer increases reflection of the transducer element.

False -The matching layer reduces reflection of ultrasound at the transducer element surface, thereby improving sound transmission across it.

The near-zone decreases with an increase in frequency.

False -The near-zone length increases with increasing frequency or element size.

The thicker the section thickness, the less its negative impact on sonographic images.

False -The thinner the section thickness, the less its negative impact on sonographic images.

The distance from the transducer to the center of the focal region is called the__.

Focal length -The focal length is the distance from the transducer to the center of the focal region. Focal zone length is the distance between equal beam widths that are some multiple of the minimum value.

Phasing can__.

Focus the beam, improve the image quality, steer the beam -Phasing can steer the beam, which focuses the beam and improves image quality.

Which of the following would likely demonstrate acoustic enhancement?

Gallbladder

Arrays have additional beams resulting from their multi-element structure called__.

Grating lobes -Array transducers demonstrate additional beams outside of the main beam resulting from their multi-element structure.

Which of the following pulsed-wave techniques demonstrates the lowest sonographic output?

Gray-scale

To receive information for display at a rapid rate, it is desirable to use a _____. a. high operating frequency b. low pulse repetition frequency c. lower operating frequency d. high pulse repetition frequency

High pulse repetition frequency

Which of the following will most likely cause range ambiguity?

High pulse repetition frequency

A flat panel display presents image information in the form of ________. a. horizontal lines read out from right to left b. vertical lines read out from right to left c. horizontal lines read out from left to right d. vertical lines read out from left to right

Horizontal lines read out from left to right

Which of the following cannot be measured or calculated by a hydrophone?

Impedance

If the aperture increases, the near-zone length__.

Increases -If the aperture or frequency increases, the near-zone length also increases.

Which of the following would most likely eliminate spectral aliasing?

Increasing the Doppler angle

Which of the following describes the far zone?

Its beam width (diameter) increases with increasing depth. -The far zone, or Fraunhofer zone is the region beyond one near-zone length. The beam width increases with increasing imaging depth.

Utilization of multiple focal points is likely to achieve a__.

Long focus -Multiple focal zones can be used to achieve, in effect, a long focus.

Increasing the transducer frequency decreases the__.

Maximum imaging depth -Increasing transducer frequency decreases the maximum penetration depth while increasing detail resolution.

If the operating frequency is reduced,__. a. PRF increases b. maximum penetration depth increases c. axial resolution improves d. frame rate increases

Maximum penetration depth increases

Axial resolution is the__.

Minimum separation necessary to resolve reflectors along the scan line -Axial resolution is the minimum reflector separation required along the direction on sound travel (along the scan line) to produce separate echoes.

Another name for the Fresnel zone is__.

Near zone -The region extending from the element out to a distance of one near-zone length is called the near field, near zone, or Fresnel zone.

Factors determining axial resolution are the__.

Number of cycles in the pulse and wavelength -Axial resolution is equal to one half of the spatial pulse length. Spatial pulse length is determined by the wavelength and number of cycles in a pulse.

The near-zone length is determined by the size and the__of the element.

Operating frequency -The near-zone length is determined by the size and the operating frequency of the element.

Sequenced, phased, and vector are types of__.

Operations -Sequenced, phased, and array are types of array scanning operations.

In a curved array, the pulses travel__.

Out in different directions -Because of the curved constructions, the pulses travel out in different directions, producing a sector-type image.

The number of voltage pulses sent to the transducer each second is called the _____. a. PRP b. PD c. DF d. PRF

PRF

In order to image deeper structures, the _____. a. time gain compensation needs to be decreased b. PRF needs to be decreased c. PRF needs to be increased d. Frame rate needs to be increased

PRF needs to be decreased

Retention of previous frames while new echo information is added in the same scanning plane is called _____. a. pixel interpolation b. harmonic imaging c. spatial compounding d. panoramic imaging

Panoramic imaging

What principle states that some materials produce a voltage when deformed by an applied pressure?

Piezoelectric principle -The piezoelectric principle states that some materials produce a voltage when deformed by an applied pressure.

When imaging deep structures, which of the following automatically occurs?

Pulse repetition frequency (PRF) is reduced.

Ultra sound gray-scale scans are ______images of tissue cross-sections and volumes.

Pulse-echo

The _____ drive(s) the transducer through the pulse delays with n pulses per second where n = pulse repetition frequency (PRF) a. channels b. coded excitation c. beam profiler d. pulser

Pulser

Which of the following artifacts would most likely place an echo at a depth much closer to the surface than it originated?

Range ambiguity

Range ambiguity produces which error in anatomic imaging?

Range too short

The unit for impedance is ________. a. rayl b. W/cm2 c. dB/cm d. watt

Rayl

For perpendicular incidence and equal impedances between media, there is no ________ and the ________ intensity equals the incident intensity.

Reflection; transmitted

Which type of artifact is most likely to produce a doubling of a single image?

Refraction

When a strong reflector is encountered, which of the following artifacts is most likely to occur?

Reverberation

Which of the following produces a set of equally spaced artifactual echoes distal to the real reflector?

Reverberation

The dimension perpendicular to the scan plane is called__.

Section thickness -The dimension perpendicular to the scan plan is called the section or slice thickness (z-axis).

Partial-volume artifact is also called__.

Section thickness artifact -Section thickness artifact is also called partial-volume artifact.

Arrays are operated in two ways, called__and__.

Sequencing; Phasing -Arrays are operated in two ways, called sequencing and phasing.

Which of the following is an effect of refraction?

Shadowing at the edge of structures

Which of the following can be considered a "cut-and-paste" technique of eliminating aliasing?

Shifting the baseline

In a single-element transducer, additional beams not included in the ultrasound beam are called__.

Side lobes -In a single-element transducer, additional beams not included in the ultrasound beam are called side lobes.

Which of the following is not a form of reverberation artifact?

Speckle

Which of the following pulsed imaging techniques demonstrates the highest acoustic output?

Spectral Doppler

Quantitative data are determined by which Doppler display?

Spectral imaging

Color Doppler mirror image artifact is commonly displayed when imaging which of the following vessels?

Subclavian artery

which of the following instrument components protects the sensitive input components a. amplifiers b. pulse delays c. beam former d. T/R switch

T/R switch

Utilizing multiple focal zones simultaneously increases image detail resolution and degrades__.

Temporal resolution -Utilizing multiple focal zones decreases temporal resolution (frame rate).

Ultrasound transducers operate according to__.

The piezoelectric principle -Ultrasound transducers operate according to the principle of piezoelectricity.

How is detail resolution artifactual?

There is a failure to resolve two reflectors.

The purpose of the coupling medium is__.

To facilitate passage of ultrasound into human tissue -Matching layers and coupling media facilitate the passage of the ultrasound across the transducer-skin boundary.

Coupling medium is applied to the transducer-tissue boundary to increase__of the sound wave.

Transmission -Matching layers and coupling media facilitate the passage (transmission) of the ultrasound across the transducer-skin boundary.

Which three-dimensional display appears similar to a radiograph? a. pulse inversion b. panoramic images c. transparent views d. surface rendering

Transparent views

A cycle is one complete variation in pressure.

True

A medical indication for a sonography examination is part of the as low as reasonably achievable (ALARA) principle. True or False

True

A range of duty factors is encountered in diagnostic sonography because of various conditions chosen by the instrument and the operator.

True

Aliasing is more common in color Doppler than in spectral Doppler. True or False

True

Amplitude and intensity describe the strength of sound.

True

Animals have applied ultrasound to detect and capture prey

True

Artifacts can help and hinder proper interpretation and diagnosis. True or False

True

Attenuation limits imaging depth.

True

Bioeffects are useful in therapeutic applications of ultrasound. True or False

True

Color Doppler imaging is superimposed on a gray-scale image

True

Cross-talk can occur when receiver gain is set too high. True or False

True

Duplication of the spectral display can occur when the Doppler angle is near 90 degrees. True or False

True

Duty factor is unitless.

True

Electromagnetic interference from nearby equipment can cloud the spectral display with lines or "snow." True or false

True

External influences can produce artifacts. True or False

True

For exposure duration up to fifty hours, there have been no significant adverse biological effects observed from temperature increases 2° C above normal. True or False

True

Harmonic frequencies are generated as sound travels through tissue.

True

High pulse repetition frequencies can result in Doppler range ambiguity artifacts. True or False

True

Increasing the Doppler angle may eliminate aliasing. True or False

True

Interfaces that scatter ultrasound energy are usually considered those that are equal to or smaller than the wavelength.

True

Most modern instruments have implemented some form of speckle reduction techniques. True or False

True

One pulse of ultrasound generates a single scan line as it travels through tissue.

True

Refraction can cause shadowing. True or False

True

Ring down is an example of reverberation artifact. True or False

True

Some artifacts are produced by improper equipment settings. True or False

True

Sound is a mechanical longitudinal wave

True

Spatial compounding can reduce attenuation artifacts. True or False

True

Stiffer media have higher sound speeds

True

The American Institute of Ultrasound in Medicine (AIUM) strongly discourages nonmedical use of ultrasound. True or False

True

The average propagation speed in soft tissue is 1.54 mm/µs.

True

The direction of travel in oblique incidence with respect to the boundary is given by the incidence angle.

True

The impedances of the media determine how much of the incident sound wave is reflected and transmitted into the second medium.

True

The output of some currently available diagnostic ultrasound devices can generate levels that produce hemorrhage in the lungs of laboratory animals. True or False

True

The shorter the pulse, the broader the bandwidth

True

Ultrasound produces a temperature increase as it propagates through tissues. True or False

True

When frequency increases, the period decreases

True

With Doppler techniques, the operator controls the pulse repetition frequency.

True

Evaluational resolution can be considered a third aspect of detail resolution.

True -Elevation (sectional thickness) can be considered a third aspect of detail resolution.

Even unfocused transducers have a natural focus.

True -Even an unfocused transducer element demonstrates some beam narrowing and is sometimes called the natural focus.

Focusing in the section-thickness plane reduces section thickness artifact.

True -Focusing in the section-thickness plane reduces section thickness artifact.

Many frequencies are present in short pulses.

True -Many frequencies (bandwidth) and wavelengths are present in short ultrasound pulses.

The operating frequency depends on the element thickness.

True -The operating frequency depends on the element thickness.

Wide bandwidth allows harmonic imaging.

True -Wide bandwidth allows harmonic imaging.

Intravascular imaging generally utilizes a frequency range__.

Up to 50 MHz -Intravascular imaging involves the use of catheter-mounted transducers in the frequency range up to 50 MHz.

Which of the following would least likely cause acoustic shadowing?

Urinary bladder

Which of the following will always eliminate aliasing?

Using continuous wave Doppler

Invasive transducer__.

Utilize smaller wavelengths -High-frequency transducers (smaller wavelengths) are utilized in invasive transducers to improve resolution and reduce the sound transmission path length (imaging depth), yielding lower attenuation of the sound wave.

Amplitude is the maximum variation that occurs in an acoustic ________.

Variable

Various formulations of lead zirconate titanate are commonly used in modern day transducer.

Various formulations of lead zirconate titanate are commonly used in modern transducers.

__array is the combination of linear and phased array operations.

Vector -A vector array transducer uses a combination of both linear and phased array operations. It presents a sector display with a non-zero width at the top.

Which image format is similar to that for convex array except that the footprint is smaller?

Vector -The vector image format is similar to that for the convex array except that the contact surface (footprint) is smaller and the top of the display is flat.

Echo reflections that produce bright and dark spots in the gray-scale image are called ________. a. speckle b. refraction c. ring down d. speed error

a

Edge shadowing is a result of ________. a. refraction of the sound beam b. attenuation of the sound beam c. reflection of the sound beam d. reverberation of the sound beam

a

Edge shadowing is caused by a. refraction b. reverberation c. propagation speed error d. a highly attenuating structure

a

How is detail resolution artifactual? a. There is a failure to resolve two reflectors. b. Actual size of structure is decreased. c. Two adjacent structures are resolved. d. Multiple reflections are displayed beneath the real reflector.

a

If an echo arrives 143 us after the pulse that produced it was emitted, it should be located at a depth of ___cm. If a second pulse was emitted 13 us before the arrival of this echo, it will be placed incorrectly at a depth of __cm. a. 11, 1 b. 14, 13 c. 13, 14 d. 13, 13

a

If the propagation speed that exists over a path traveled is 1.44 mm/μs, the display will place the echo ________. a. too far from the transducer b. lateral from the actual location c. too close to the transducer d. medial from the actual location

a

It may be possible to resolve slice thickness artifact by ________. a. using harmonic imaging b. using multiple focal zones c. using a phased-array transducer d. decreasing the imaging depth

a

Multiple sample gates will appear ________. a. to manage range ambiguity b. when utilizing power Doppler c. when multiple focal zones are used d. with a low pulse repetition frequency

a

Propagation speed error displaces structures ________. a. axially b. medially c. laterally d. anteriorly

a

Section thickness artifact is also called ________. a. partial-volume artifact b. ring-down artifact c. comet-tail artifact d. resonance phenomenon

a

The most common artifact encountered in Doppler ultrasound is __ a. aliasing b. range ambiguity c. spectrum mirror image d. location mirror image e. electromagnetic interference

a

There is no problem with aliasing as long as the Doppler shifts are __ half the PRF a. less than b. approximately equal to c. greater than d. all of the above e. none of the above

a

There must be ________ samples per cycle of Doppler shift to correctly obtain an image. a. two b. three c. four d. five

a

Under-sampling the Doppler shift is likely to cause ________. a. aliasing b. shadowing c. a mirror image d. range ambiguity

a

Which artifact displaces structures axially? a. Speed error. b. Grating lobes. c. Refraction. d. Reverberation.

a

Which of the following artifacts is exclusive to pulse-Doppler imaging? a. Aliasing. b. Mirror image. c. Enhancement. d. Range ambiguity.

a

Which of the following can be considered a "cut-and-paste" technique of eliminating aliasing? a. Shifting the baseline. b. Increasing the pulse repetition frequency. c. Decreasing the depth of the sample volume. d. Increasing the Doppler angle.

a

Which of the following is an effect of refraction? a. Shadowing at the edge of structures. b. Two adjacent structures seen as one. c. Incorrect representation of tissue densities. d. Structures displayed medial from correct location.

a

Which of the following results from the underlying distribution of scatterers? a. Speckle. b. Ring-down. c. Comet tail. d. Section thickness.

a

Which of the following will always eliminate aliasing? a. Using continuous wave Doppler. b. Increasing the transducer frequency. c. Decreasing the transducer frequency. d. Increasing the pulse repetition frequency.

a

Which of the following would most likely eliminate spectral aliasing? a. Increasing the Doppler angle. b. Increasing the transducer frequency. c. Decreasing the pulse repetition frequency. d. Increasing the depth of the sample volume.

a

which artifact should be suspected if one observes two gestational sacs when scanning through the rectus abdominis muscle a. refraction b. reverberation c. speckle d. enhancement

a

The display form that presents the depth in the horizontal axis and the amplitude of the echo in the vertical axis is ____. a. a mode b. b mode c. c mode d. m mode

a mode

All of the following are acoustic variables ________:

a. pressure b. density d. particle vibration

Attenuation in soft tissue is due primarily to ________.

absorption

Attenuation encompasses ________.

absorption Scattering Reflection

Volume/ 3D imaging is accomplished by__ a. scanning from different angles b. spatial compounding c. expanding beyond the normal limits of transducer d. acquiring many parallel two dimensional scans

acquiring many parallel two dimensional scans

The most common artifact encountered in pulsed Doppler ultrasound is ________.

aliasing

Under-sampling the Doppler shift is likely to cause ________.

aliasing

The best way to describe the role of ultrasound scattering in diagnostic imaging is it ___________________.

allows us to see the tissue interfaces

Gain is the ratio of ____ a. amplifier input to output voltage power b. transmission output to amplifier input c. amplifier output to input electric power d. voltage ration squared or voltage ratio to the second power

amplifier output to input electric power

Increased voltage amplitude produced by the pulser increases the _______ and _______ of ultrasound pulses produced by the transducer a. echo delays, compression b. amplitude, intensity c. PRF, PRP d. pulse delays, attenuation

amplitude and intensity

Analog-to-digital converters convert the __ voltage representing echoes to __ or digital signal processing and storage a. analog, numbers b. digital, analog c. ultrasound, numbers d. analog, bits

analog, numbers

Prudent practice of sonography involves application of the ________ principle.

as low as reasonably achievable (ALARA)

Linear and convex are types of ________ arrays. a. scanning b. focusing c. operation d. assembly

assembly

The _____ and _____ determine the maximum imaging depth. a. operating frequency, propagation speed b. minimum amplifier gain, attenuation c. attenuation, maximum amplifier gain d. transducer element, propagation speed

attenuation; maximum amplifier gain

Propagation speed error displaces structures ________.

axially

Additional beams emitted from an array transducer __________. a. are stronger than the main beam b. duplicate structures laterally c. demonstrate multiple reflections d. produce echoes that are routinely imaged

b

Axial resolution is determined by ________ and lateral resolution is determined by ________. a. pulse width; pulse length b. pulse length; pulse width c. pulse width; operating frequency d. operating frequency; pulse length

b

Clutter is also known as __________. a. noise b. flash c. speckle d. cross-talk

b

Color Doppler mirror image artifact is commonly displayed when imaging which of the following vessels? a. Abdominal aorta. b. Subclavian artery. c. Internal jugular vein. d. Common carotid artery.

b

Enhancement is caused by a. strongly reflecting structures b. weakly attenuating structures c. strongly attenuating structures d. refracting boundary e. propagation speed error

b

If the highest Doppler shift frequency present in a signal exceeds _____ the PRF, aliasing will occur. a. one tenth b. one half c. two times d. five times e. ten times

b

Increasing the PRF to avoid aliasing can cause the following.. a. baseline shift b. range ambiguity c. spectrum mirror image d. location mirror image e. speckle

b

Mirror imaging of a Doppler spectrum is most likely a result of the ________. a. wall filter being set too low b. Doppler gain being set too high c. pulse repetition frequency being set too low d. pulse repetition frequency being set too high

b

Range ambiguity produces which error in anatomic imaging? a. Range too long. b. Range too short. c. Doppler shift too low. d. Doppler shift too high.

b

Range ambiguity produces which error in anatomic imaging? a. range too long b. range too short c. intensity too high d. doppler shift too high e. doppler shift too low

b

Range ambiguity produces which error in spectral doppler studies a. incorrect spectral peaks b. incorrect gate location c. intensity too high d. intensity too low e. all of the above

b

Reverberation results in added reflectors being imaged with equal __ a. depth b. separation c. width d. brightness

b

Speckle artifact is most likely caused by ________. a. refraction b. interference c. pulse width d. multiple reflections

b

The assumptions in the design of sonographic instruments include all of the following except ________. a. sound travels in a straight line b. sound travels at different speeds in soft tissue c. echoes originate from objects located on the beam axis d. echogenicity is a property of the structure

b

To avoid aliasing, a signal voltage must be sampled at least _____ times per cycle. a. 1 b. 2 c. 3 d. 4 e. 5

b

Ultrasound pulses contain a range of frequencies called the ________.

bandwidth

The ____ is where the action originates. a. signal processor b. code excitation c. beam former d. transmit/receive switch T/R

beam former

Which system component is responsible for electronic beam steering a. summer b. beam former c. scan converter d. signal processor

beam former

Section thickness artifact is a result of ________.

beam width perpendicular to scan plane

Panoramic imaging expands the image a. beyond the normal limits of a transducers field of view b. by using a special panoramic transducer c. quality, allowing for a much smoother image d. resolution

beyond the normal limits of a transducer's field of view

Acoustic output is important when considering ________.

bioeffects and safety

Gray scale ultrasound instruments show echo amplitude as __ on the video display a. brightness b. decibels c. dynamic range d. ITC

brightness

A duplication artifact associated with echoes interacting with a strong reflector is called ________. a. cross-talk b. comet tail c. mirror image d. partial volume

c

A reduction in echo amplitude from reflectors behind a strongly reflecting structure is called ________. a. speckle b. comet tail c. shadowing d. enhancement

c

Equally spaced reflections that decrease in amplitude with increases in depth describe ________. a. refraction b. attenuation c. reverberation d. axial resolution

c

If the maximum imaging depth is 5cm, the frequency is 2 MHZ, and the doppler angle is zero, what is the maximum flow speed that will avoid aliasing and range ambiguity cm/s? a. 100 b. 200 c. 300 d. 400 e. 500

c

If the propagation speed in a soft tissue path is 1.60 mm/us, a diagnostic instrument assumes a propagation speed too __ and will show reflectors too ___ the transducer a. high, close to b. high, far from c. low, close to d. low, far from

c

Storage of the last several frames acquired before freezing is called _____. a. picture archiving b. triplex c. freeze d. cine loop

cine loop

In which of the following code excitation techniques do ensembles of pulses drive the transducer to generate a single scan line a. volume imaging b. pixel interpolation c. spatial compounding d. coded

coded

All of the following are acoustic variables except a. density b. particle vibration c. pressure d. compression

compression

The ability of a gray scale display to distinguish between echoes of slightly different intensities is called _____ resolution. a. contrast b. axial c. spatial d. temporal

contrast

Optison and Imagent are names of ultrasound ________.

contrast agents

Three-dimensional imaging requires many adjacent tissue ________ to build the image.

cross-sections

Aliasing does not occur in ________. a. color Doppler b. duplex imaging c. spectral Doppler d. continuous-wave Doppler

d

Enhancement of an echo results from a structure having ________ than surrounding structures. a. higher impedance b. lower density c. higher attenuation d. lower attenuation

d

If a pulsed wave Doppler sample volume is located at at depth of 8 cm, the sampled echoes arrive at what time following the emission of the pulse us? a. 25 b. 50 c. 75 d. 104 e. 117

d

If the propagation speed through a medium is faster than 1.54 mm/μs, the reflector will be placed ________. a. medial to the correct position b. lateral to the correct position c. deeper than the correct position d. shallower than the correct position

d

If the pulse repetition frequency (PRF) is 6 kHz, which of the following Doppler shifts will cause aliasing? a. 1 kHz. b. 2 kHz. c. 3 kHz. d. 4 kHz.

d

Increasing the pulse repetition frequency to avoid aliasing can cause ________. a. clutter b. speckle c. mirror image d. range ambiguity

d

Mirror image is commonly seen around which structure? a. Kidney. b. Stomach. c. Pancreas. d. Diaphragm.

d

Received echoes originating off center from the central beam are caused by ________. a. speckle b. speed error c. range ambiguity d. section thickness

d

The Nyquist limit describes the ________. a. flow speed through a stenosis b. driving force behind blood flow c. resistance of blood flow in a straight tube d. minimum number of samples required to avoid aliasing

d

The attenuation group of sonographic artifacts includes ________. a. slice thickness, shadowing, and enhancement b. reverberation, ring-down, and edge shadowing c. comet tail, range ambiguity, and slice thickness d. edge shadowing, focal banding, and enhancement

d

The comet-tail artifact is a case of ________. a. refraction b. resolution c. attenuation d. reverberation

d

The propagation group of sonographic artifacts includes ________. a. comet tail, mirror image, shadowing b. enhancement, focal banding, shadowing c. grating lobe, enhancement, range ambiguity d. mirror image, range ambiguity, slice thickness

d

The pulser of an instrument automatically reduces the pulse repetition frequency for deeper imaging to avoid the _______ _______ artifact a. comet tail b. grating lobe c. mirror image d. range ambiguity

d

When a strong reflector is located in the scan plane, which of the following artifacts is likely to occur? a. aliasing b. range ambiguity c. spectrum mirror image d. location mirror image e. speckle

d

When imaging deep structures, which of the following automatically occurs? a. Frame rate increases. b. Nyquist limit increases. c. Pulse repetition period (PRP) is reduced. d. Pulse repetition frequency (PRF) is reduced.

d

Which of the following artifacts may display an incorrect shape of a structure? a. Mirror image. b. Reverberation. c. Grating lobes. d. Propagation speed error.

d

Which of the following artifacts would most likely place an echo at a depth much closer to the surface than it originated? a. Speed error. b. Mirror image. c. Slice thickness. d. Range ambiguity.

d

Which of the following is a common and convenient solution to eliminate aliasing? a. Increasing transducer frequency. b. Decreasing pulse repetition frequency. c. Decreasing transducer frequency. d. Shifting the baseline.

d

Which of the following is not a form of reverberation artifact? a. Comet tail. b. Ring down. c. Mirror image. d. Speckle.

d

Which of the following will most likely cause range ambiguity? a. High wall filter setting. b. High operating frequency. c. Multiple sample volumes. d. High pulse repetition frequency.

d

which of the following can correct or eliminate aliasing a. decreased PRF b. decreased doppler angle c. increased operating frequency d. baseline shifting e. more than one of the above

d

What units are used to quantify attenuation?

dB

Which of the following is attached to the rear face of the transducer element a. matching layer b. damping c. coupling media d. ceramics

damping

If frequency increases, each cycle (period) ________.

decreases

Test objects evaluate ________.

detail resolution

The __ determines the brightness of the echoes on the display a. scan converter b. analog to digital converter c. cathode ray tube d digital to analog converter

digital to analog converter

Additional beams emitted from an array transducer __________.

duplicate structures laterally

The fraction of time that pulsed ultrasound is on is called ________.

duty factor (DF)

Averaging sequential frames improves ________. a. penetration depth b. frame rate c. temporal resolution d. dynamic range

dynamic range

The ratio of the largest to the smallest amplitude that a system can handle is called ________. a. compression b. dynamic range c. signal processing d. demodulation

dynamic range

Which of the following operator controls adjusts compression a. TGC b. depth c. dynamic range d. overall gain

dynamic range

Compression decreases the ________ range to a range that the ______ and human _______ can handle. a. dynamic range, display, vision b. compensation, dynamic range, vision c. PRF, TGC, operator d. universe, student, brain

dynamic, display, vision

Range Ambiguity can occur in which of the following a. imaging instruments b. duplex instruments c. pulsed wave doppler instruments d. color flow instruments e. all of the above

e

If the PRF is 4 kHz, which of the following doppler shifts will cause aliasing. kHz? a. 1 b. 2 c. 3 d. 4 e. more than one of the above

e, 3&4

If the PRF is 10 kHz, which of the following doppler shifts will cause aliasing. kHz? a. 1 b. 2 c. 3 d. 4 e. none of the above

e, anything above 5

Diagnostic ultrasound imaging includes ultrasound/ pulse generation, propagation, reflection in tissue, and the reception of returning__ a. pulses b. echoes c. colors d. relatives

echoes

The attenuation group of sonographic artifacts includes ________.

edge shadowing, focal banding, and enhancement

Which of the following techniques is considered the imaging version of palpation a. elastography b. pixel interpolation c. panoramic imaging d. volume imaging

elastography

Normally, the number of channels utilized does not exceed the number of: A. cycles per second B. pulse delays C. elements in the transducer D. ultrasound pulses

elements in the transducer

Which of the following constitutes a reception channel a. beam former, signal processor, image processor, display b. elements, amplifier, digitizer, delay path c. elements, pulser, signal processor, delay path d. beam former, pulser, amplifier, scan converter

elements, amplifier, digitizer, delay path

Reflected echoes displaying falsely high amplitudes describe ________.

enhancement

Aliasing is caused by over-sampling of the Doppler shifts. true or false

false

B color is a function of the preprocessing in the image processor a. true b. false

false

Beam width parallel to the scan plane causes partial volume artifact. true or false

false

Ceramics used as materials in the production of modern ultrasound transducer elements are naturally piezoelectric. a. true b. false

false

Contrast and temporal resolution relate more directly to the transducer. a. true b. false

false

Damping material in pulsed transducers increases the SPL a. true b. false

false

Enhancement weakens the amplitude of structures distally. true or false

false

Grating lobes are essential for the proper operation of a linear phased array transducer. true or false

false

Human vision is limited to a dynamic range of about 30 dB a. true b. false

false

Image memories used in diagnostic ultrasound instruments are of the analog type. a. true b. false

false

Lateral duplication of a single structure into two separate structures describes mirror imaging artifact. true or false

false

Mirror image artifact is not a factor in color Doppler imaging. true or false

false

The Nyquist limit is equal to the pulse repetition frequency (PRF). true or false

false

The signal processor filters, detects, and demodulates the echo signal. a. true b. false

false

The ultrasound instrument is composed of a beam former, a signal processor, an image processor, and a transducer. a. true b. false

false

Three dimensional presentation is a function of the signal processor a. true b. false

false

Ultrasound PRF is equal to the voltage PRF. a. true b. false

false

the signal processor properly locates each series of echoes corresponding to each scan line a. true b. false

false

Clutter is also known as __________.

flash

Increased intensity of echoes in the focal region of the beam is called _______.

focal banding

Echo complete scan of the sound beam produces an image on the display that is called a __ a. real time b. dynamic range c. lateral resolution d. frame

frame

The _____ is the number of sonographic images entered into memory per second. a. frame rate b. PRF c. image refresh rate d. cine loop

frame rate

Holding and displaying one frame out of the sequence is known as a. a scan line b. freeze frame c. the frame rate d. cine loop

freeze frame

Bandpass filtering of the sound beam is used to eliminate a. frequencies outside of the bandwidth b. the fundamental frequency c. secondary frequencies d. side lobe artifacts

frequencies outside of the bandwidth

Attenuation increases with increasing ________.

frequency

The Doppler effect is a change in echo ________.

frequency

the following are terms used to describe continuous wave ultrasound?

frequency wavelength propagation speed

The ___ determines how much amplification is accomplished in the amplifier a. postprocessing control b. persistence control c. TGC control d. Gain control

gain control

Almost all ultrasound contrast agents contain ________.

gas microbubbles

Tissue-equivalent phantoms are filled with a substance containing ________.

graphite

If the propagation speed through the second medium is greater than through the first medium, the transmission angle is ________.

greater than the incidence angle

When the fundamental frequency is filtered out, which of the following occurs? a. pixel interpolation b. volume imaging c. harmonic frequencies d. spatial compounding

harmonic frequencies

The fundamental beam is much wider, lateral resolution can be improved with a. pixel interpolation b. spatial compounding c. real time imaging d. harmonic imaging

harmonic imaging

Stiffer media have ________ sound speeds

higher

The ___ stores the gray scale image and allows it to be displayed on a system display a. analog- digital converter b. transducer c. beam former d. image memory

image memory

After leaving the signal processor and before it enters scan conversion, the scan line data enters which system component a. image processor b. signal processor c. amplifier d. digitizer

image processor

If a higher imaging frequency is used, resolution is __, the imaging depth ___, and the time gain compensation slope must be ___ a. improved, increases, decreased b. improves, decreases, decreased c. improved, decreases, increased d. degraded, increases, decreased

improved, decreases, increased

If beam power increases, intensity ________.

increases

If the beam area decreases, the intensity ________.

increases

If you switch to a lower frequency for penetration, the wavelength of the transducer ________.

increases

The rate at which energy passes through a unit area is called a. intensity b. amplitude c. power d. attenuation

intensity

The rate at which energy passes through a unit area is called ________.

intensity

Speckle artifact is most likely caused by ________.

interference

A gray-scale ultrasound image is the visible counterpart of a/an ________.

invisible object

If the number of cycles in a pulse is reduced, the pulse duration ________.

is decreased

Frequency ________ wavelength. a. is directly proportional to b. is inversely proportional to c. is equal to d. has no bearing on

is inversely proportional to

Which of the following describes the far zone a. the length of the far zone increases with increases in frequency b. it lies within one near zone length c. it is called the fresnel zone d. its beam width increases with increasing depth

its beam width increases with increasing depth

Wavelength is the _______ over which one cycle occurs.

length

A rectangular image display is seen when using a ________ transducer.

linear

Vertical parallel scan lines are seen with which transducer format?

linear

Enhancement of an echo results from a structure having ________ than surrounding structures.

lower attenuation

Increasing the transducer frequency decreases the ____. a. detail resolution b. frame rate c. maximum imaging depth d. propagation speed

maximum imaging depth

Sound requires a ________ through which to travel.

medium

The Nyquist limit describes the ________.

minimum number of samples required to avoid aliasing

A duplication artifact associated with echoes interacting with a strong reflector is called ________.

mirror image

The propagation group of sonographic artifacts includes ________.

mirror image, range ambiguity, slice thickness

Echoes produced by ________ objects have different ________ than the pulses sent into the body.

moving; frequencies

Maximum amplifier gain is determined by _____. a. manufacturer b. input c. noise d. output

noise

Pulse repetition frequency (PRF) refers to the ________ of pulses occurring in one second.

number

Factors determining axial resolution are the a. propagation speed & number of cycles in pulse b. frequency & wavelength c. number of cycles in pulse & wavelength d. beam diameter & element thickness

number of cycles in pulse & wavelength

PRF refers to the __ of pulses occurring in one __ a. speed, second b. number , second c. type, minute d. cycle, second

number, second

Section thickness artifact is also called ________.

partial-volume artifact

The averaging of sequential frames together to provide a smoother image appearance is called ____. a. persistence b. pixel interpolation c. spatial compounding d. mulit focus

persistence

PACS stands for: a. Pictures accessed by computers b. Picture archiving and communication system c. Patient access computer system d. Picture access computer system

picture archiving and communication system

The piezoelectric material commonly used in hydrophones is ________.

polyvinylidene fluoride (PVDF)

Pixel interpolation, persistence, and panoramic imaging are examples of _____. a. spatial compounding b. postprocessing c. preprocessing d. signal processors

preprocessing

Diagnostic ultrasound transducers generate a ________ of sound into the body.

pulse

Sonography is medical anatomic imaging using a ________ technique.

pulse echo

Which technique uses two pulses per scan line rather than one a. panoramic imaging b. pixel interpolation c. spatial compouding d. pulse inversion

pulse inversion

Axial resolution is determined by ________ and lateral resolution is determined by ________.

pulse length; pulse width

Which system component produces the electrical voltages that drive the transducer a. digitizer b. piezoelectric element c. summer d. pulser

pulser

Detection converts voltage pulses from ______________ form to _____ form. a. analog, digital b. radio frequency, video c. video, radio frequency d. pulses, echoes

radio frequency, video

Increasing the pulse repetition frequency to avoid aliasing can cause ________.

range ambiguity

Regions of lower pressure and density are called ________.

rarefactions

The unit for impedance is ________.

rayl

If the impedances are equal between two media in perpendicular incidence, there is no ________.

reflection

Edge shadowing is a result of ________.

refraction of the sound beam

Equally spaced reflections that decrease in amplitude with increases in depth describe ________.

reverberation

Mirror-image artifact is a form of ________.

reverberation

Ring-down artifact is a form of ________.

reverberation

The comet-tail artifact is a case of ________.

reverberation

Which of the following reformats and organizes echo data along the scan lines for processing, storage, display a. beam former b. summer c. scan converter d. signal processor

scan converter

Sonographic images are composed of many ________.

scan lines

The pulse repetition frequency is the number of pulses that occur in a single ________.

second

Received echoes originating off center from the central beam are caused by ________.

section thickness

A ________ scan is shaped like a slice of pie.

sector

The method by which each pulse originates from the same starting point is called a ________ image.

sector

The American College of Radiology (ACR) Ultrasound Accreditation Program requires at least ________ testing for instrument quality control.

semiannual

A reduction in echo amplitude from reflectors behind a strongly reflecting structure is called ________.

shadowing

Weakening of echoes distal to a strongly attenuating structure describes ________.

shadowing

If the propagation speed through a medium is faster than 1.54 mm/µs, the reflector will be placed ________.

shallower than the correct position

which of the following digitally filters, detects, and compresses echo data a. digitizer b. beam former c. summer d. signal processor

signal processor

The pulse delays have a ____ input from the pulser but ____ output(s) to the transducer element. a. Single, double b. controlled, uncontrolled c. slow, faster d. single, multiple

single, multiple

The assumptions in the design of sonographic instruments include all of the following except ________.

sound travels at different speeds in soft tissue

Which imaging techniques is most likely to visualize a structure beneath a calcification a. panoramic imaging b. harmonic imaging c. pixel interpolation d. spatial compounding

spatial compounding

Echo reflections that produce bright and dark spots in the gray-scale image are called ________.

speckle

Which of the following results from the underlying distribution of scatterers?

speckle

Elastography is an ultrasound imaging mode that depicts tissue _____. a. propagation speed b. stiffness c. temperature d. density

stiffness

Propagation speed is primarily determined by the ________ of the medium

stiffness

Amplitude and intensity are indicators of the sound wave's ________.

strength

The brightness of an echo, as presented on the display, represents the____ of the echo.

strength

The brightness of the dot corresponds to the ________ of the returning echo.

strength

Which resolution depends on penetration depth, lines per frame, and the number of focuses? a. detail b. contrast c. axial d. temporal

temporal

Increasing the frame rate improves a. temporal resolution b. axial resolution c. detail resolution d. penetration depth

temporal resolution

Utilizing multiple focal zones simultaneously increases image detail resolution and degrades ________. a. temporal resolution b. sectional thickness c. harmonic frequencies d. contrast resolution

temporal resolution

The Nyquist limit is ________.

the upper limit to the Doppler shift that can be properly detected

The location of each dot corresponds to the ________ of the echo to return.

time

Which system control adjusts amplitudes by different reflector depths a. persistence b. compression c. overal gain d. time gain compensations

time gain compensations

Compensation amplifies echoes differently, according to their arrival ______. a. echoes b. voltages c. points d. times

times

Doppler ultrasound measures the movement of ________.

tissue & blood

Utilizing additional focal points causes the temporal resolution to _____. a. double b. degrade c. remain unchanged d. improve

to degrade

Multiple sample gates will appear ________.

to manage range ambiguity

If the propagation speed that exists over a path traveled is 1.44 mm/µs, the display will place the echo ________.

too far from the transducer

A significant increase in the temperature of tissues close to the transducer is a result of ________.

transducer self-heating

The ______ directs(s) the driving voltages from the pulser to the transducer during transmission and directs returning echo voltages to amplifiers during reception. a. T/R switch b. signal processor c. channels d. beam former

transmit/receive (T/R) switch

Propagation speed is the speed at which a wave ________ through a medium

travels

Aliasing is more common in color Doppler than in spectral Doppler. true or false

true

Artifacts can help and hinder proper interpretation and diagnosis. true or false

true

Cross-talk can occur when receiver gain is set too high. true or false

true

Duplication of the spectral display can occur when the Doppler angle is near 90 degrees. true or false

true

Dynamic range is the ratio of the largest to smallest power that a system can handle a. true b. false

true

Electromagnetic interference from nearby equipment can cloud the spectral display with lines or "snow." true or false

true

External influences can produce artifacts. true or false

true

High pulse repetition frequencies can result in Doppler range ambiguity artifacts. true or false

true

If doppler shift is 2.6 kHz, no aliasing would result with a PRF of 10 kHz. true or false

true

If operating frequency is increased to decrease the possibility ( by increasing attenuation), the possibility of aliasing increases true or false

true

If the number of focal zones is increased, the frame rate decreases. a. true b. false

true

Increasing the Doppler angle may eliminate aliasing. true or false

true

Intensity of the echo information is stored as binary numbers in memory elements. a. true b. false

true

M mode is a presentation of echo depth versus time a. true b. false

true

Most modern instruments have implemented some form of speckle reduction techniques. true or false

true

Operating frequency reduction reduces the Doppler shift. true or false

true

Refraction can cause shadowing True or false

true

Refraction can cause shadowing. true or false

true

Shadowing results in decreased echo amplitudes. True or false?

true

Solving aliasing by decreasing operating frequency increases the possibility of range- ambiguity artifact. true or false

true

pixel interpolation fills in missing pixels by averaging adjacent pixels a. true b. false

true

temporal resolution in M mode and A mode is equal to the PRP a. true b. false

true

There must be ________ samples per cycle of Doppler shift to correctly obtain an image.

two

Plant studies are useful primarily for ________.

understanding cavitational effects in living tissue

It may be possible to resolve slice thickness artifact by ________.

using harmonic imaging