Practice Questions Flashcards by Valery Dzev

All of the following are terms describing axial resolution EXCEPT?

longitudinal
depth
radial
azimuthal
range

azimuthal

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Which one of the following statements is correct?

long pulses decrease axial resolution

long pulses produce high frequencies

long pulses mean more damping material has been applied

more cycles in the pulse promotes better imaging

long pulses decrease axial resolution

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When the sonographer increases the imaging depth what happens to the duty factor?

increases the duty factor
decreases the duty factor

increases the duty factor

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If the attenuation coefficient is 3 dB per centimeter and the sound path length is 3 centimeters, how much of the original strength of the sound beam is left at 3 centimeters?

one half
one fourth
one eighth
one sixteenth

one eighth

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Which of the following will have the best axial resolution?

1.7 MHz with 4 cycles in the pulse
2.5 MHZ with 2 cycles in the pulse
1.7 MHz with 5 cycles in the pulse
2.5 MHz with 3 cycles in the pulse

2.5 MHZ with 2 cycles in the pulse

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Reducing side lobe and grating lobe artifacts can be achieved by a process called…

apodization
Fast Fourier Transform
Autocorrelation
dynamic ranging

apodization

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What is the wavelength of 2 MHz sound in soft tissue?
1.54 mm
2 mm
0.77 mm
cannot be determined

0.77 mm

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Two pulses are created by different transducers. Both have the same number of cycles. The pulse containing cycles of a lower frequency has a __?

longer pulse duration
shorter pulse duration
lower pulse repetition frequency
longer pulse repetition frequency

longer pulse duration

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Three sound waves with identical frequencies of 3 MHz have powers of 2 mW, 5 mW and 15 mW. They all travel through three media - wood, brick, and fat - with identical thicknesses of 5 cm. Which one of the following statements is true?

the waves travel through all three media at the same speed since they have identical frequencies
the waves travel through all three media at different speeds because the media are different
the waves travel through all three media at different speeds because the waves have different powers

the waves travel through all three media at different speeds because the media are different

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In the case of pulsed ultrasound, what is the maximum value of the duty factor?

100%
1
less than 100%
none of the above

less than 100%

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An anechoic region extending downward from a very strong attenuating reflector which can be diagnostically beneficial to a sonographer is known as?

enhancement
shadowing
comet tail
side lobe
focal enhancement

shadowing

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An area of hypoechoic or anechoic extending from the edge of a curved reflector due to refraction at the edge of the curved reflector is known as?

reverberation
comet tail
side lobe
edge shadow
enhancement

edge shadow

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A replica or second copy of a structure incorrectly appearing on an image is called?

focal enhancement
mirror image
speed error
refraction

mirror image

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A hyperechoic region beneath tissue with abnormally low attenuation which can be a diagnostic benefit to a sonographer is called?

reverberation
edge shadow
shadowing
side lobe
enhancement

enhancement

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Grating lobe artifacts are reduced by dividing each PZT element into small peices. This process is called?

subdicing
autocorrelation
fast fourier transforming
focusing

subdicing

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All of the following are requirements for a quality assurance program EXCEPT:

assessments of system components
assessment of film quality
repairs
preventive maintenance
record keeping

assessment of film quality

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An artifact that appears as tissue texture close to the transducer that does not directly correspond to true anatomic structures are called…

noise
speckle
resolution artifact
harmonic imaging

speckle

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A form of mirror image artifact that appeared on a spectral Doppler display is called…

crosstalk
noise or speckle
spatial resolution artifact
oblique reflector

crosstalk

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This mode represents the amplitude of moving structures over time.

A mode
B mode
C mode
M mode

M mode

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All of the following are goals for a quality assurance program except:

proper operation of equipment
detect gradual changes
accelerates downtime
reduce non-diagnostic exams
reduce repeat scans

accelerates downtime

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Which of the following is a predictor of maximum temperature increases under most clinical relevant conditions.

mechanical index
thermal index
cavitation
thermocouple
hydrophone

thermal index

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The AIUM in clinical safty and prudent use have concluded all of the following except:

no confirmed harmful bioeffects from exposure to diagnostic ultrasound have ever been reported
It is possible that bioeffects might be identified in the future.
the benefit to the patient outweighs the risks
it is appropriate to use diagnostic ultrasound for entertainment

it is appropriate to use diagnostic ultrasound for entertainment

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The science of identifying and measuring the characteristics of an ultrasound beam that are relevant to its potential for producing bioeffects is called…

risk - benefit relationship
dosimetry
empirical approach
thermal index

dosimetry

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he ability to place echoes in proper positions while imaging from different orientations is called…

longitudinal resolution
lateral resolution
registration accuracy
temporal resolution

registration accuracy

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This microprobe is used to measure the acoustic pressure at specific locations within the sound beam. hydrophone calorimeter thermocouple liquid crystal

hydrophone

The original intensity is 4mW/cm squared. There is attenuation of 6 decibels. what is the final intensity: 16 mW/cm squared 8 mW/cm squared 1 mW/cm squared 2 mW/cm squared

1 mW/cm squared

What is the intensity suggested by the AIUM for an unfocused beam? 100 mW/cm sq. 1 W/cm sq. 10 mW/cm sq. 100 W/cm sq.

100 mW/cm sq.

The time of flight (range equation) is 130 microseconds. How deep is the reflector? 3 cm 5 cm 10 cm 13 cm 20 cm

10 cm

Wlhich intensity is important in the study of bioeffects? SPTA SATA SPPA SPTP

SPTA

This test object is a fluid filled tank containing strategically placed steel pins or plastic strings that measure axial resolution, lateral resolution, caliper accuracy, and dead zone. Tissue equivalent phantom AIUM 100 mm Test object Doppler phantom Hydrophone

AIUM 100 mm Test object

The thermal index is related to? stable cavitation tissue heating transient cavitation attenuation

tissue heating

The ability of the system to place echoes in proper positions while imaging from different orientation is called? dead zone sensitivity registration accuracy slice thickness

registration accuracy

An ultrasound pulse has a width of 4mm, and a length of 2 mm. what is the best estimate of the systems axial resolution? 2 mm 4 mm 1 mm 2 kHz

4 mm

The sonographer changes the transducer from a 3 MHz to a 6 MHz transducer but does not change the imaging depth. Which of the following will remain unchanged? period frequency wavelength intensity

intensity

Which of the following is the lowest intensity? SPTA SATA SPPA SPTP

SATA

Which of the following is the typical values for impedance? 1250 - 1750 cm 1 - 7 rayls 1.25 - 1.75 Mrayls 15 - 17 bytes

1.25 - 1.75 Mrayls

Which of the following is the unit for pressure? kg cm mm Pa kg/cm squared

A Sound wave is best described as? a transverse wave a wave that humans can hear a series of compressions and rarefactions an oblique displacement of energy

a series of compressions and rarefactions

If a force is applied to a surface and that force is tripled however, the surface area is also tripled, what would be the new pressure? three times larger than the original three times smaller than the original unchanged six times larger than the original

unchanged

What is another term for "shadowing by refraction"? comet tail clean shadow edge shadow dirty shadow

edge shadow

All of the following result in too many echoes on the image EXCEPT? mirror image comet tail grating lobes shadowing

shadowing

Which pulse has a lower propagation speed? 10 MHz pulse 2 MHz pulse neither pulse cannot be determined

neither pulse

The maximum value of the intensity of an acoustic wave is 60 lb/in sq. while the minimum density is 20 lb/in sq. What is the amplitude of the wave? 20 lb/in sq. 40 lb/in sq. 60 lb/in sq. none of the above

20 lb/in sq.

The amplitude of an acoustic wave decreases from 27 pascals to 9 pascals. If the initial power in the wave was 27 watts, what is the wave's final power? 3 watts 9 watts 1 watt none of the above

3 watts

A sonographer can adjust the duration of an acoustic pulse since it depends on the maximum imaging depth. True False

False

The PRF of a 6 MHz transducer is greater than the PRF of the 3 MHz transducer. True False

False

Which of the following best describes the empirical investigation of bioeffects? cause - effect exposure - response exposure - cure cause - response

exposure - response

The upper limit for the SPTA intensity of a focused ultrasound beam when there have been no observed bioeffects is: 1 mW/cm sq. 10 mW/cm sq. 100 mW/cm sq. 1 W/cm sq.

1 W/cm sq.

With sector scanning, images with greater detail (spatial resolution) are created when the number of acoustic pulses per degrees of sector is increased. True False

True

In diagnostic imaging, it is possible to image with 150 lines/frame, 26 frames per second and a maximum imaging depth of 20 cm. True False

False

A diagnostic ultrasound system can produce 45 images per second, to a maximum depth of 10 cm and create each image with 200 acoustic pulses. True False

False

The diameter of a disc shaped unfocused PZT crystal is 1 cm. What is the best estimate for the minimum lateral resolution of the ultrasound system? 1 mm 5 mm 1 cm 5 cm

5 mm

When using a curvilinear array transducer, one must be aware that at increased depths the resolution decreases due to the sound beams not being parallel to each other True False

True

If the impedance of the transducers matching layer is 2.6 MRayls and the impedance of the transducers PZT crystal is 3.4 MRayls, what is the best estimate for the impedance of the skin? 3.8 MRayls 2.8 MRayls 1.5 MRayls 3.4 MRayls

1.5 MRayls

When the sonographer changes the depth of view, which of the following will remain unchanged? PRF propagation speed PRP duty factor

propagation speed

What is the thickness of the matching layer of a 2MHz pulsed wave transducer? 0.77 mm 1.54 mm 1/2 wavelength of PZT 1/4 wavelength of matching layer

1/4 wavelength of matching layer

A receiver function that converts negative voltages into positive voltages. demodulation reject compression amplification

demodulation

A function of the receiver that places an envelope around the electrical bumps to even them out is called? amplification demodulation smoothing compression

smoothing

The smallest building block of a digital picture is called? byte converter bit ROI pixel

pixel

Which one of the following is considered most important for the sonographer with regard to bioeffects? pulse repetition frequency frequency duration of study imaging mode

duration of study

What is the meaning of the term in vivo? observable in a living body observation based on an experiment discernable in a test tube estimated in a computer simulation

observable in a living body

Which of the following terms best describes the mechanistic investigation of bioeffects? cause - effect exposure - response cause - response exposure - cure

cause - effect

If a sound pulse travels through a large mass at a speed of 1.2 mm/microsecond, what happens to the position of the echoes from reflectors deeper than the mass? they are placed in too shallow a position on the image they are placed in too deep a position on the image they are likely to be placed at the correct depth

they are placed in too deep a position on the image

Which of the following produces shadowing? reverberation multipath reflection attenuation

attenuation

Which of the following is "not" a potential cause of artifact in diagnostic imaging? operator error equipment malfunction patient motion ultrasound physics none of the above

none of the above

Which artifact results in improper side-by-side positioning of reflectors? multipath comet tail refraction reverberation

refraction

All of the following are true of read zoom EXCEPT? preprocessing function of a receiver same number of pixels are in the original ROI and the zoomed image on the screen, the pixels in the zoomed image are larger than those in the ROI the same number of ultrasound pulses are used to create the original ROI and the zoomed image

preprocessing function of a receiver

What happens to an image when the number of bits allocated to each pixel increases? spatial detail improves frame rate increases field of view expands more shades of gray

more shades of gray

All of the following would be an extra precaution if the patient care activities may generate splashes or sprays of blood or body fluid EXCEPT: masks shoe covers face shield eye protection

shoe cover

In which of the following emergency situations would CPR or an AED be used. (more than one choice) - stroke - heart attack - fainting - respiratory arrest - seizures - dehydration - vaso-vagal reaction

- heart attack - respiratory arrest

Standard precautions apply to all of the following EXCEPT? hair blood excretions body fluids mucous membranes

hair

Plant studies are useful for understanding: the effects on wound healing when focal lesions will occur thermal effects on living tissues long term effects on living tissues cavitational effects on living tissues

cavitational effects on living tissues

Ultrasound has a small potential to produce a biological effect because: it is a form of energy of the frequency range employed contrast agents introduce bubbles into the tissues of the routine request for sonographic examinations fetal tissue is less tolerant to temperature increases

it is a form of energy

Heating of soft tissue is proportional to the: thickness of the tissue mechanical index operating frequency spatial peak intensity propagation speed of the medium

operating frequency

Transient cavitation is most dependent on the: thermal index ultrasound pulse size of the gas bubble type of contrast agent used expansion rate of the micro bubbles

ultrasound pulse

Absorption of the sound beam is highest in: air bone fluids muscle soft tissue

bone

Biological studies of the cytoskeleton have shown: ultrasound modifies cancer cells ultrasound increases the risk of cavitation ultrasound induced changes are temporary ultrasound produces ling term tissue damage ultrasound increases the risk of tissue hyperplasia

ultrasound induced changes are temporary

Microbubbles will expand and collapse when: pressure is applied disease is encountered the thermal index reached 2.0 the temperature of bone increases by 1 degrees C the temperature of soft tissue increases by 2 degrees C

pressure is applied

Which of the following remains constant as the beam travels through a medium? Attenuation Attenuation coefficient Intensity Amplitude

Attenuation coefficient

MRSA requires __________ precautions and tuberculosis requires __________ precautions. Contact, airborne Droplet, contact Airborne, droplet Contact, droplet

Contact, airborne

A linear transducer is preferred for _____ exams, while sector array is preferred for _____ exams. Cardiac; vascular Vascular; OB Musculoskeletal; cardiac Abdomen; OB

MSK; cardiac

PW ultrasound frequency is determined by the ______, while CW ultrasound frequency is determined by ______. Thickness of the element and the speed in element; electrical frequency applied to the element Manufacturer; technologist Electrical frequency applied to the element; thickness of the element Electrical frequency applied to the element; speed of sound in the element

Thickness of the element and the speed in element; electrical frequency applied to the element

Which of the following correctly describes the wavelength of a sound wave? Increases as frequency increases Adjustable by sonographer by changing output power Shorter wavelengths are Preferred to produce best 2D image All of the above

Shorter wavelengths are Preferred to produce best 2D image

What are 2 things required for sound wave reflections to occur?

Perpendicular incidence and a different acoustic impedance of 2 media along its path

What variable is necessary for the range equation and 13 microsecond rule to estimate distance to the reflectors? Transducer frequency Width of the reflector Round trip time of the pulse All of the above

Round trip time of the pulse

Which of the following increases or improves with the addition of a damping layer on a transducer? Duty factor System sensitivity Axial resolution Quality factor

Axial resolution

A longer near field zone occurs with Wider element diameters and higher frequencies Wider element diameters and lower frequencies Narrower element diameters and higher frequencies Narrower element diameters and lower frequencies

Wider element diameters and higher frequencies

Endocavity transducers allow imaging at increasing frequencies, but offer degraded ____ @ deeper depths. Axial resolution Contrast resolution Lateral resolution Temporal resolution

Lateral resolution

How does a sonographer improve axial resolution? Add focal zone to the image Decrease PRF Reduce sector size Change to a higher frequency transducer

Change to a higher frequency transducer

Decreasing the number of cycles in a pulse will: a. increase the frequency of the wave b. increase the wavelength c. degrade the axial resolution d. improve the axial resolution

d. improve the axial resolution

Increasing the transducer frequency on a multihertz transducer will: a. improve the axial resolution only in the near field b. increase the spatial pulse length c. improve the axial resolution in the near and far field d. improve the lateral resolution in the near field

c. improve the axial resolution in the near and far field

A system that performs parallel processing will demonstrate: a. improved lateral resolution with degraded temporal resolution b. improved lateral resolution with degraded axial resolution c. increased frame rates with reduced lateral resolution d. two images side by side on the display

c. increased frame rates with reduced lateral resolution

Blood flow volume changes in the body are mainly controlled by which 2 factors? a. cardiac function and peripheral resistance b. viscosity and friction c. vessel radius and resistance d. cardiac function and vessel radius

a. cardiac function and peripheral resistance

Which of the following can be used to improve beam penetration on cases of high body mass index? a. deactivate coded excitation b. activate harmonic imaging c. higher frequency transducer d. increase transmit power

d. increase transmit power

Which of the following is considered the capacitative component of the circulatory system? a. heart chambers b. capillaries c. arteries d. veins

d. veins

In an electronically focused US beam, the intensity is _____. a. greatest in the near field b. greatest at the focal point c. greatest i n the far field d. same throughout the length of the beam

b. greatest at the focal point

Transducers can be electronically focused by: a. adding an acoustic lens to the face of the transducer b. using a convex shaped PE element c. varying timing of the release of the pulses d. using a concave shaped element

c. varying timing of the release of the pulses

Which statement correctly describes reflection? a. the greater the difference in acoustic impedance of the two media, the greater the amount of reflection at their interface b. the greater the difference in attenuation of the two media, the greater the amount of reflection at their interface c. the greater the difference in propagation speed, of the two media the greater the amount of reflection at their interface d. the greater the difference in the distance the sound travels in each media, the greater the amount of reflection at their interface

a. the greater the difference in acoustic impedance of the two media, the greater the amount of reflection at their interface

In a resting patient, the highest resistance in the arterial system is in the: a. capillaries b. arterioles c. venules d. left ventricle

b. arterioles

What i s used to form. the sector shaped FOV for a phased array transducer? a. electronic focusing b. acoustic. lens c. curved arrangement of elements d. electronic steering

d. electronic steering

What is the best way to reduce slice thickness artifact that is causing false echoes in a superficial structure? a. turn off harmonic imaging b. increase the transducer frequency c. use a standoff pad d. decrease transducer frequency

c. use a standoff pad

Tissue Doppler imaging uses ____ settings than PW Doppler. a. higher frequency b. lower filter c. lower frequency d. higher filter

b. lower filter

_____ compares each reflected echo to the same echo from a previous US pulse to determine if motion is present. a. temporal resolution b. autocorrelation c. registration accuracy d. quadrature detection

b. autocorrelation

Which of the following is a resonance artifact only seen with a gas/tissue interface? a. posterior shadowing b. ring down c. mirror imaging d. misregistration

b. ring down

As the Doppler angle increases, the cosine of the angle: a. is unaffected b. becomes a negative number c. increases d. decreases

d. decreases

The speed of a 5MHz continuous wave is 1.8 km/sec. The wave is then pulsed with a duty factor of 0.5. Calculate the new propagation speed.

1.8 km/sec The propagation speed depends ONLY on the medium and does not change between continuous to pulsed wave

Practice Questions Flashcards

Collection of questions from URR, class quizzes, and the Edelman book (106 cards)