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251 Cards in this Set
- Front
- Back
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Sound waves are: a) electric b) mechanical, transverse c) spectral d) longitudinal, mechanical |
d) longitudinal, mechanical |
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The speed of ultrasound in soft tissue is closest to: a) 1,540 km/s b) 1.54 km/msec c) 1,500 m/s d) 1,540 mm/s |
c) 1,500 m/s |
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The frequency closest to the lower limit of ultrasound is: a) 19,000 kHz b) 10,000 MHz c) 20,000 msec d) 15,000 Hz |
d) 15,000 Hz *20,000 Hz - 20,000 MHz |
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Which is not an acoustic variable? a) density b) pressure c) distance d) intensity |
d) intensity |
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The effects of soft tissue on ultrasound are called? |
Acoustic Propagation Properties |
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ALL of the following are true EXCEPT: a) Two waves with identical frequencies must interfere constructively b) Constructive interference is associated with waves that are in-phase c) Out-of-phase waves interfere destructively d) Waves of different frequencies may exhibit both constructive and destructive interference at different times |
a) Two waves with identical frequencies must interfere constructively |
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Put in decreasing order: deca deci micro centi |
deca deci centi micro |
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__________ is the time to complete one cycle. a) pulse duration b) pulse period c) period d) duration period |
c) period
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Which of the following sound waves is ultrasonic and least useful in diagnostic imaging? a) 30 KHz b) 8 MHz c) 8,000 Hz d) 3,000 kHz e) 15 Hz |
a) 30 KHz |
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What is the frequency of a wave with 1 msec period: a) 10,000 Hz b) 1,000 kHz c) 1 kHz d) 1 MHz |
c) 1 kHz |
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____________ is the distance covered by one cycle: a) pulse length b) wavelength c) cycle distance d) cycle duration |
b) wavelength |
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Which of the following is determined by the source and the medium? a) frequency b) period c) propagation speed d) range resolution |
d) range resolution *also wavelength |
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Propagation speed = __________ x __________ a) pulse duration x wavelength b) period x frequency c) pulse duration x frequency d) frequency x wavelength |
d) frequency x wavelength |
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As a result of _____________ the propagation speed increases. a) increasing stiffness and density b) increasing stiffness and elasticity c) decreasing compressibility and density d) decreasing stiffness and density |
c) decreasing compressibillity and density |
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Put in decreasing order of propagation speed: a) gas b) liquid c) solid |
c) solid b) liquid a) gas |
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If the frequency of ultrasound is increased from 0.77 MHz to 1.54 MHz, what happens to the wavelength: a) doubles b) halved c) remains the same d) 4 times greater |
b) halved |
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A sound wave's frequency is 10 MHz. The wave is traveling in soft tissue. What is its wavelength: a) 0.15 mm b) 1.54 mm c) 15.4 mm d) 0.77 mm e) 10 MHz |
a) 0.15 mm *wavelength is reciprocal of frequency |
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If the frequency of an ultrasound wave is doubled, what happens to the period: a) doubles b) halved c) remains the same d) 4 times greater |
b) halved *period and frequency are reciprocals |
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If the frequency of ultrasound is increased from 0.77 MHz to 1.54 MHz, what happens to the propagation speed: a) doubles b) halved c) remains the same d) 4 times greater |
c) remains the same |
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The units of pulse repetition frequency are: a) per minute b) msec c) mm/us d) MHx |
a) per minute |
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The time from the beginning of a pulse until its end is: a) period b) pulse duration c) pulse length d) PRF |
b) pulse duration |
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What happens to the speed of sound in a medium when the bulk modulus of the medium increases: a) faster b) slower c) unchanged |
a) faster |
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* _____________ resolution is determined by the spatial pulse length: a) radial b) image c) axial d) angular |
a) radial or c) axial |
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If a wave's amplitude is doubled, what happens to the power: a) nothing b) halved c) doubled d) quadrupled |
d) quadrupled |
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If the level of an acoustic variable ranges from 55 to 105, what is the amplitude: a) 105 b) 50 c) 25 d) 55 |
c) 25 |
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Power of sound has units of: a) dB b) dB/cm c) watts d) watts/cm sqd |
c) watts |
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If the intensity of a sound beam remains unchanged while the beam area is reduced in half, what has happened to the power: a) quadrupled b) doubled c) halved d) unchanged |
c) halved |
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Which of these intensities is smallest: a) SATP b) SPTP c) SATA |
c) SATA |
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The duty factor for continuous wave ultrasound is: a) 10.0 b) 1% c) 1.0 d) 0.0% |
c) 1.0 |
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What is the minimum value of the duty factor: a) 10.0 b) 1% c) 1.0 d) 0.0% |
0.0% |
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What are the units of intensity? a) watts b) dB c) watts/cm sqd d) cm sqd |
c) watts/cm sqd |
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What happens to the speed of sound in a medium when the bulk modulus of the medium decreases: a) faster b) slower c) unchanged |
b) slower |
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The units of attenuation are _____; this is a ________ scale: a) mm/cm, parametric b) dB/m, multiplicative c) none, relative d) dB, logarithmic |
d) dB, logarithmic |
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Sound intensity is decreased by 75%. How many decibels of attenuation is that: a) 6 dB b) 9 dB c) 5 dB d) 10 dB |
a) 6 dB |
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The fundamental frequency of a transducer is 2.5 MHz. What is the second harmonic frequency: a) 1.25 MHz b) 4.5 MHz c) 5 MHz d) 5 cm |
c) 5 MHz |
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A pulse is emitted by a transducer and is traveling in soft tissue. The go-return-time, or time-of-flight, of a sound pulse is 130 microseconds. What is the reflector depth: a) 10 cm b) 10 mm c) 10 m d) 130 mm e) 13 cm |
a) 10 cm |
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If a 5 MHz sound wave is traveling in the tissues listed below, which will have the longest wavelength: a) fat b) air c) muscle d) bone |
d) bone *speed of sound in bone is highest |
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If a 5 MHz sound wave is traveling in the tissues listed below, which will have the shortest wavelength: a) fat b) air c) muscle d) bone |
b) air *speed of sound in air is lowest |
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What is the approximate attenuation coefficient of 1 MHz ultrasound in soft tissue: a) 0.5 dB/cm b) 1 cm c) 3 dB/cm d) 1 dB |
a) 0.5 dB/cm |
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The rayl is the unit of: a) intensity b) reflectance c) density d) impedance |
d) impedance |
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Impedance is the ____________ of _____________ and ________________. a) product, propagation speed, density b) sum, stiffness, density c) quotient, stiffness, propagation speed d) difference, attenuation, density |
a) product, propagation speed, density |
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What are attenuation's three components? |
scattering reflection absorption |
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For soft tissue, the approximate attenuation coefficient in dB/cm is equal to one-half ________ in _________. a) wavelength, mm b) frequency, Hz c) frequency, MHz d) impedance, rayls |
c) frequency, MHz |
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As the impedances of two media become vastly different, the: a) reflection increases b) transmission increases c) refraction increases d) absorption increases |
a) reflection increases |
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The angle between an ultrasound pulse and the boundary between two media is 90 degrees. What is this called: a) direct incidence b) oblique incidence c) indirect incidence d) orthogonal incidence |
d) orthogonal incidence |
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The angle between an ultrasound pulse and the boundary between two media is 56 degrees. This is called: a) direct incidence b) oblique incidence c) indirect incidence d) orthogonal incidence |
b) oblique incidence |
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Refraction only occurs if there are: a) normal incidence & different impedances b) indirect intensity & different propagation speeds c) oblique incidence & different propagation speeds d) oblique frequency & identical impedances |
c) oblique incidence & different propagation speeds |
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With normal incidence, what factors affect refraction of ultrasound: a) propagation speeds b) frequencies c) attenuation coefficients d) none of the above |
d) none of the above |
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True/False: With right angle incidence, reflections are always generated at a boundary if the propagation speeds of the media are different. |
False |
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_____________ is a redirection of ultrasound in many directions as a result of a rough boundary between two media. a) refraction b) Rayleigh scattering c) scattering d) reflection |
c) scattering |
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Which of the following tissues is most likely to create Rayleigh scattering: a) red blood cells b) muscle c) fat d) bone |
a) red blood cells |
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True/False: With normal incidence the angle is 180 degrees. |
False |
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Under which of the following conditions is axial resolution improved: a) decreased spatial pulse length b) decreased pulse amplitude c) decreased imaging depth d) decreased pixel size e) decreased beam diameter |
a) decreased spatial pulse length |
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Snell's Law describes physics of ______________. a) ultrasound b) reflection c) refraction d) transmission |
c) refraction |
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The most likely amount of reflection at a boundary between soft tissues is: a) 1% b) 22% c) 34% d) 99% |
a) 1% |
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The most typical amount of transmission at a boundary in biologic media is: a) 1% b) 22% c) 34% d) 99% |
d) 99% |
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Sound is traveling from medium 1 to medium 2. Propagation speeds of M1 and M2 are 1,600 m/s and 1,500 m/s, respectively. There is oblique incidence. a) angle of incidence > angle of reflection b) angle of incidence = angle of reflection c) angle of incidence < angle of reflection |
b) angle of incidence = angle of reflection |
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True/False: Doppler shifts always occur if the sound source and receiver are in motion. |
False |
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Which of the following is associated with power mode Doppler: a) poor temporal resolution & flash artifact b) lower sensitivity & good temporal resolution c) high sensitivity & high frame rates d) flash artifact & reduced sensitivity e) good temporal resolution & flash artifact |
a) poor temporal resolution & flash artifact |
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The Doppler shift is measured of: a) ration of incident frequency to reflector frequency b) sum of incident frequency & reflected frequency c) difference between incident & reflected frequency d) product of incident and reflected frequencies |
c) difference between incident & reflected frequency |
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True/False: The sonographer cannot change, directly or indirectly, the duty factor of an ultrasound machine. |
False |
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Depth calibration of a machine measures 100 mm spaced wires to be 90 mm apart. Scanning reflectors 50 mm apart, what will the machine calculate the distance to be: a) 40 mm b) 45 mm c) 60 mm d) 65 mm |
b) 45 |
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True/False: There have not been biological effects from ultrasound found in the laboratory. |
False |
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In an analog scan converter, what component stores the image data: a) computer memory b) video tape recorder c) dielectric matrix d) none of the above |
c) dielectric matrix |
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What is the correct scientific notation for: mega milli kilo micro |
10^6 10^-3 10^3 10^-6 |
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How many cm are 60 millimeters: a) 600 b) 6 c) 0.6 d) 0.06 |
b) 6 |
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True/False: Lateral resolution is also called Axial resolution. |
False |
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True/False: Lateral resolution is also called Azimuthal resolution. |
True
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True/False: Lateral resolution is also called Longitudinal resolution. |
False |
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True/False:
Lateral resolution is also called Range resolution. |
False |
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What are the correct units for: frequency speed intensity attenuation |
Hz m/s W/cm sqd dB |
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What increases patient exposure: a) exam time b) frequency c) video taping d) wavelength |
a) exam time |
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True/False: Shadowing may result from high amounts of reflection of ultrasound energy. |
True |
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Where are harmonics created: a) in the receiver b) in the transducer c) in the tissues d) in the beam former |
c) in the tissues |
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How is range ambiguity artifact eliminated: a) lower the PRF b) raise the PRF c) increase the Gain d) use lower frequency transducer |
a) lower the PRF |
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For Doppler, which incident angle results in no shift: a) 180 b) 90 c) 0 d) 45 |
b) 90 |
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Which transducer would be best to image superficial structures: a) small diameter, high frequency b) small diameter, low frequency c) large diameter, high frequency d) large diameter, low frequency |
a) small diameter, high frequency |
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A transducer with more than one active element is called: a) multipurpose b) annular c) mechanical d) array |
d) array |
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How many bits are needed to represent 16 shades of grey: a) 2 b) 3 c) 4 d) 5 |
c) 4 *2x2x2x2 = 16 |
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What information does Doppler shift provide: a) flow b) cardiac output c) velocity d) speed |
c) velocity |
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True/False: A sound wave is a pressure wave made of compressions and rarefactions. |
True |
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*A hydrophone is used to measure: a) velocity b) frequency c) intensity d) phase |
c) intensity or b) frequency |
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Images on videotape are stored using: a) magic b) magnetism c) paper d) computer memory |
b) magnetism |
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Circumferences may be measured in units of: a) cm b) cm sqd c) cubic cm d) cubits |
a) cm |
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Decimal uses a base of 10, binary uses a base of : a) 1 b) 2 c) 5 d) 10 |
b) 2 |
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If the frame rate increases and the lines per frame is unchanged, what else must happen: a) ultrasound speed increases b) frequency increases c) depth increases d) depth decreases |
d) depth decreases |
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Which of these cannot be performed by a sonographer: a) adjust overall gain b) clean VCR recording heads c) clean pixels d) adjust time gain compensation |
c) clean pixels |
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Which of the following is not a beam steering technique for a mechanical scanhead: a) rotating wheel b) phased beam c) oscillating disc d) oscillating mirror |
b) phased beam |
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True/False: A system which was working well now does not display clear images in the far field. This may be a problem with the transducer. |
True |
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True/False: A system which was working well now does not display clear images in the far field. This may be a problem with the receiver. |
True
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True/False: A system which was working well now does not display clear images in the far field. This may be a problem with the monitor. |
True
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True/False: A system which was working well now does not display clear images in the far field. This may be a problem with the scan converter. |
True |
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How many decibels are related to a 90% decrease in imaging power: a) -1 dB b) -10 dB c) -90 dB d) -100 dB |
b) -10 dB *this is a reduction to 1/10th of the original value |
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If the output power of an ultrasound machine is calibrated in dB and the output is increased by 20 dB, the beam intensity is increased: a) 100 times b) 1,000,000 times c) 20 times d) 10 times |
a) 100 times |
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Which has the greatest amount of attenuation: a) bone b) fat c) water d) muscle |
a) bone |
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Which of the following will result in the greatest number of shades of gray in a digital image display: a) large pixels with many bits/pixels b) small pixels with few bits/pixels c) many TV lines per frame d) high contrast e) narrow dynamic range |
a) large pixels with many bits/pixels |
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What is the responsibility of the sonographer: a) clean the filters b) adjust the recorder c) adjust the converter matrix d) change paper |
c) adjust the converter matrix |
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With good images on the display but not on the printer, one should: a) increase the gain b) check the scan head c) check the scan converter d) adjust the recorder |
d) adjust the recorder |
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To measure the ultrasound beam intensity, use: a) calibrated hydrophone b) lateral oscilloscope c) water filled phantom d) tissue equivalent phantom |
a) calibrated hydrophone |
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When the ultrasound machine displays only strong reflecting objects and nothing else, the sonographer should: a) adjust far gain b) increase output power c) increase lateral resolution d) adjust TGC's |
b) increase output power |
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Compression is used to: a) decrease the amplitude b) decrease the range of amplitudes c) decrease the range of frequencies |
b) decrease the range of amplitudes |
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Reject is used to: a) adjust the appearance of highly reflective objects b) adjust the appearance of lowly reflective objects c) improve axial resolution d) improve digital scan converter sensitivity |
b) adjust the appearance of lowly reflective objects |
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If a reflector is moved twice as far away from the transducer, how will this affect the time-of-flight of a sound pulse: a) quadruple it b) double it c) no change d) halve it |
b) double it |
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A single element transducer is focused: a) by the manufacturer b) cannot be focused c) by increasing power d) by the sonographer |
a) by the manufacturer |
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An ultrasound machine has a digital scan converter but has an analog input signal. The machine needs to have a: a) hybrid multiplexer b) modem c) analog to digital converter d) digital monitor |
c) analog to digital converter |
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Under which of the following conditions is lateral resolution improved: a) decreased beam diameter b) decreased pulse duration c) decreased imaging depth d) decreased pixel size e) decreased spatial pulse length |
a) decreased beam diameter |
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In which way is an annular phased array transducer different than a linear phased array transducer: a) the linear is steered mechanically b) the linear can have multiple focal zones c) the annular can create a sector shaped image d) the linear has higher PRF e) the annular is steered mechanically |
e) the annular is steered mechanically |
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In which of these biologic tissues will sound waves propagate most quickly: a) tendon b) blood c) lung d) fat e) amniotic fluid |
a) tendon |
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Which of the following best describes a sound beam: a) electrical impulses b) a collection of mechanical vibrations in the form of compressions and rarefactions c) a wave that man can hear d) electromechanical variations e) ionic vibrations |
a) electrical impulses |
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You are performing a quality assurance study on an ultrasound system using a tissue equivalent phantom. You make an adjustment using a knob on the system console that changes the appearance of reflector brightness from fully bright to barely visible. What are you evaluating: a) resolution b) dynamic range c) system sensitivity d) vertical calibration e) slice thickness |
b) dynamic range |
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Which of the following best describes the features of a sound wave and medium that determine the speed of sound in the medium: a) density and stiffness of the medium b) density of the medium and power of the sound beam c) elasticity of the medium and frequency of the sound beam d) stiffness of the medium and elasticity of the medium e) PRP of the sound wave and density of the medium |
c) elasticity of the medium and frequency of the sound beam |
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While scanning in a water tank, what location in a sound beam has the highest intensity: a) focal point b) focal zone c) Fresnel zone d) Fraunhofer zone e) half value depth |
a) focal point |
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Which of these factors has the greatest influence on PRP: a) display depth b) thickness of PZT crystal c) attenuation of the sound beam d) impedance of the medium e) display's dynamic range |
a) display depth |
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Which of the following choices best describes an ideal epidemiologic bioeffects study: a) randomized and prospective b) benefits outweigh the risks c) retrospective and optimized d) ideal and non-biased e) prudent and safe |
a) randomized and prospective |
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Which of the following will result in the highest mechanical index: a) high frequency and low power b) high intensity and high frequency c) low frequency and high signal amplitude d) low intensity and low frequency |
c) low frequency and high signal amplitude |
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ALL of the following statements regarding in-vitro bioeffects are true EXCEPT: a) in-vitro bioeffects conclusions are clinically relevant b) in-vitro bioeffects are always real c) in-vitro bioeffects are very important d) in-vitro bioeffects may not be applicable to clinical settings |
a) in-vitro bioeffects conclusions are clinically relevant |
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Under which circumstance is the mechanical index highest: a) high frequency and low power b) high intensity and high frequency c) low intensity and low frequency d) low frequency and high signal amplitude |
d) low frequency and high signal amplitude |
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Which of the following improves the signal-to-noise ratio: a) dynamic range b) frame averaging c) gray scale d) edge enhancement e) receiver gain |
b) frame averaging |
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Under which circumstance is cavitation most likely to occur: a) high frequency and low power b) high intensity and high frequency c) low intensity and low frequency d) low frequency and high signal amplitude |
d) low frequency and high signal amplitude |
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What is the accuracy of reflector depth position on an A-mode, B-mode, or M-mode display called: a) range resolution b) horizontal calibration c) axial resolution d) speed error artifact e) depth calibration |
e) depth calibration |
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Pre-processing occurs: a) when the patient is scanned b) when images are transferred to the VCR c) after the images are on the tape d) when the image exits the scan converter |
a) when the patient is scanned |
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Post-processing occurs when the image: a) is played off of the VCR b) entered the A/D converter but before display c) after it leaves the A/D converter d) after it leaves the scan converter |
b) entered the A/D converter but before display |
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The region from the transducer to the minimum beam cross-sectional area is the: a) Fraunhofer zone b) Fresnel zone c) focus d) Snell's length |
b) Fresnel zone |
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Biologic effects have not been documents below what intensity (SPTA): a) 100 W/cm b) 100 mW/m sqd c) 100 mW/cm sqd d) 100 mW/cm cubed |
c) 100 mW/cm sqd |
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What is the standard for communication between medical imaging computers: a) ALARA b) PACS c) D-to-A conversion d) DICOM e) A-to-D conversion |
d) DICOM |
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The Curie temperature has which effect: a) the backing material delaminates from the active element b) the glue binding the crystal & matching layer melts c) the ferroelectric material is depolarized d) the matching layer changes its impedance |
c) the ferroelectric material is depolarized |
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What happens to venous blood flow to the heart during expiration: a) increased b) decreased c) unchanged |
b) decreased |
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Which of the following has propagation speed closest to soft tissue: a) muscle b) fat c) bone d) air |
a) muscle |
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In a B-mode display, which of the following axes are used for the amplitude of the reflection: a) z-axis b) m-axis c) x-axis d) y-axis e) time base axis |
a) z-axis |
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What is displayed on the x-axis of an M-mode image: a) time b) time-of-flight c) reflector depth d) echo intensity e) red blood dell velocity |
a) time |
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What is displayed on the y-axis of an M-mode image: a) time b) time-of-flight c) echo intensity d) red blood cell velocity |
b) time-of-flight |
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True/False: A sonographer's education ends when they become registered. |
False |
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The dynamic range is the ratio of the smallest to the largest ____________ that a system can process without distortion: a) amplitude b) frequency c) phased delay d) spatial length |
a) amplitude |
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When may a patient revoke their consent to be treated: a) at any time b) when it is safe to terminate the procedure c) never |
a) at any time |
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If the intensity is increased by 3 dB, it: a) doubles b) triples c) halved d) quartered |
a) doubles |
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What determines the frequency of a sound beam from a pulsed transducer: a) voltage applied to the PZT b) PZT thickness c) frequency of the system d) PRF of the pulser |
b) PZT thickness |
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While propagating, a sound wave is refracted. Finally it returns to the transducer. The system returns to the transducer. The system processes the sound wave as if it has: a) refracted and returned b) traveled in a straight line, reflected and returned c) traveled in a straight line, atttenuated, reflected and returned |
b) traveled in a straight line, reflected and returned |
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What measures the output of a transducer: a) receiver b) display c) hydrometer d) hydrophone |
d) hydrophone |
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The impedance of tissue is 3x10^5 rayls and for the PZT crystal is 6x10^6 rayls. What is the best impedance fro the matching layer: a) 36x10^6 b) 3,600 c) 10,000 d) 9.5x10^5 e) 9x10^4 |
d) 9.5x10^5 |
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Put in increasing order of propagation speed: air bone water |
air water bone |
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Which type of artifact appears most commonly with highly reflective objects: a) reverberations b) mirroring c) shadowing d) enhancement e) defocusing |
c) shadowing |
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What can pulsed wave Doppler measure that continuous wave Doppler cannot: a) duration b) speed c) velocity d) location e) frequency |
d) location |
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What is the fraction of time that a transducer is transmitting: a) duty factor b) pulse duration c) period d) PRF spatial duration |
a) duty factor |
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Which of the following clinical modalities has the lowest output intensity: a) pulsed Doppler b) continuous wave Doppler c) power Doppler d) duplex scanning e) gray scale imaging |
e) gray scale imaging |
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What is the location of the minimum cross-sectional area of the ultrasound beam called: a) focus b) Fraunhofer zone c) far zone d) near zone |
a) focus |
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The dB is defined as the _________ of two intensities: a) sum b) difference c) product d) ratio |
d) ration |
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If the power of a sound wave is increased by a factor of 8, how many decibels is this: a) 3 dB b) 6 dB c) 9 dB d) 8 dB |
c) 9 dB |
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An ultrasound system is set at 0 dB and is transmitting at full intensity. What is the output power when the system is transmitting at 50% of full intensity: a) -3 dB b) -50 dB c) 10 dB d) 3 dB e) -10 dB |
a) -3 dB |
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An ultrasound system is set at 0 dB and is transmitting at full intensity. What is the output power when the system is transmitting at 10% of full intensity: a) -3 dB b) -50 dB c) 40 dB d) 3 dB e) -10 dB |
e) -10 dB *1/10th |
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The Doppler shift is the ___________ of two frequencies: a) sum b) difference c) product e) ratio |
b) difference |
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What is propagation speed determined by: a) wavelength b) intensity & density c) amplitude d) density & elasticity e) density & amplitude |
d) density & elasticity |
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If 300,000 cycles occur in a second, what is the wave's frequency: a) 3 MHz b) 30 kHz c) 300 MHz d) 3 kHz e) 0.3 MHz |
e) 0.3 MHz |
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What may be a unit of amplitude: a) cm b) Hz c) msec d) watts e) none of the above |
a) cm |
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A Doppler exam is performed with a 5 MHz probe and a PRF of 15 kHz. Which of these Doppler shifts will create aliasing: a) 2 kHz b) 2.5 kHz c) 7.5 kHz d) 14 kHz |
d) 14 kHz |
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Which of the following choices determines the signal amplitude in the transducer of an ultrasound system: a) reflected intensity of the sound beam b) post processing c) edge enhancement filtering d) persistence e) demodulation |
a) reflected intensity of the sound beam |
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In an air-tissue interface, what percentage of the ultrasound is reflected: a) 0% b) near 0% c) 50% d) near 100% |
d) near 100% |
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Traveling through the same medium, if the frequency is doubled, the wavelength is: a) unchanged b) doubled c) halved d) quartered |
c) halved |
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Traveling through the same medium, if the frequency is doubled, the propagation speed is: a) unchanged b) doubled c) halved d) quartered |
a) unchanged |
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True/False: Increasing the frequency increases the penetration depth. |
False |
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True/False: Axial resolution is affected by focusing. |
False |
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If a manufacturer changed the lines per frame and kept the imaging depth the same, what else would change: a) PRF b) period c) frame rate d) duty factor |
c) frame rate |
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Which of the following has the greatest influence on temporal resolution: a) propagation speed and imaging depth b) frequency of sound and propagation speed c) wavelength of sound and propagation speed d) output power and frequency |
a) propagation speed and imaging depth |
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In a real time scanner, which of these choices determines the maximum frame rate: a) depth of view b) pixel size c) attenuation coefficient d) lateral resolution |
a) depth of view |
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Multiple reflections that are equally spaced are called: a) refractions b) reverberations c) shadows d) comets |
b) reverberations |
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What artifact has a grainy appearance and is caused by the interference effects of scattered sound: a) spackle b) reverberation c) slice thickness d) speckle e) section thickness |
d) speckle |
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All of the following will improve temporal resolution EXCEPT: a) increased line density b) single rather than multi focus c) higher frame rate d) shallower depth of view e) slower speed of sound in a medium |
a) increased line density |
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Impedance is the product of ___________ and ____________. |
density and propagation speed |
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True/False: The manufacturer increases the number of lines per frame. As a result, frequency may have to be decreased. |
False |
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True/False:
The manufacturer increases the number of lines per frame. As a result, frame rate may have to be decreased. |
True |
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True/False:
The manufacturer increases the number of lines per frame. As a result, the sector angle may have to be decreased. |
True |
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True/False:
The manufacturer increases the number of lines per frame. As a result, imaging depth may have to be decreased. |
True |
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True/False:
The manufacturer increases the number of lines per frame. As a result, power output may have to be decreased. |
False |
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What component of a transducer changes electrical to mechanical and mechanical back to electrical energy? |
PZT |
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True/False: Sonographers cannot affect a patient's exposure to acoustic energy. |
False |
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Attenuation of ultrasound in soft tissue is closest to: a) 3 dB/1 MHz b) 1 dB/cm/10 MHz c) 2 dB/cm d) 0.6 dB/cm/MHz |
d) 0.6 dB/cm/MHz
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How many bits are needed to represent 1024 gray shades: a) 1024 b) 8 c) 10 d) 3 e) 512 |
c) 10 |
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True/False: Gray scale can be changed by the sonographer. |
True |
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The distance to a target is doubled. The time-of-flight for a pulse to travel to the target and back is: a) 4 times b) 8 times c) the same d) 2 times |
d) 2 times |
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If 3 MHz sound has 2 dB of attenuation in 1 cm of tissue, what is the amount of attenuation of 6 MHz sound in 0.5 cm of the same tissue: a) 5 dB b) 2 dB c) 10 dB d) 1.5 dB |
b) 2 dB |
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Volume has which of the following units: a) cm b) cm sqd c) cm cubed d) cm quadrupled |
c) cm cubed |
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Which of the following is proportional to the square of the amplitude: a) period b) attenuation c) power d) frequency e) speed |
c) power |
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What are typical clinical Doppler frequencies: a) 1 - 10,000 Hz b) 1 - 10 MHz c) 2 - 1,000 kHz d) 40 - 45 kHz |
a) 1 - 10,000 Hz |
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What Doppler angle is most inaccurate: a) 15-30 degrees b) 30-45 degrees c) 45-60 degrees d) 60-75 degrees |
60-75 degrees |
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Changing which of the following would not cause any change in a hard copy image output: a) TGC b) overall gain c) output power d) display brightness and contrast e) depth of view |
d) display brightness and contrast |
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A quality assurance program: a) is not needed in small labs b) is very time consuming and expensive c) is needed by all labs d) cannot be performed by sonographers |
c) is needed by all labs |
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What is the actual time that an ultrasound machine is creating a pulse: a) duty factor b) period c) pulse period d) pulse duration |
d) pulse duration |
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The angle of incidence of an ultrasound beam is perpendicular to an interface. Two media have the same propagation speeds. What process cannot occur: a) refraction b) reflection c) transmission d) attenuation |
a) refraction |
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What component of the ultrasound unit contains the memory bank: a) transducer b) receiver c) display d) scan converter |
d) scan converter |
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An ultrasound wave travels through two media and has attenuation of 3 dB in the first and 5 dB in the second. What is the total attenuation: a) 15 dB b) 8 dB c) 3/5 dB d) 5/8 dB |
b) 8 dB |
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According to the AIUM statement on bioeffects, there have been no confirmed bioeffects below intensities of _______ Watts per square centimeter SPTA. a) 10 b) 0.01 c) 0.1 d) 1 e) 100 |
c) 0.1 |
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Fill=in of an anechoic structure such as a cyst is known as all of the following EXCEPT: a) partial volume artifact b) slice thickness artifact c) section thickness artifact d) ghosting artifact |
d) ghosting artifact |
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What is the range of frequencies created by medical diagnostic Doppler transducers: a) 4-10 Hz b) 10-20 MHz c) 1-10 kHz d) 2-20 Hz e) 2-10 MHz |
e) 2-10 MHz |
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True/False: Doppler shifts are always created when the source and receiver are in motion relative to each other. |
False |
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What is the significance of gray scale variation in the spectrum of a pulsed wave Doppler display: a) it represents the number of red blood cells creating the reflection b) it represents the velocity of red blood cells c) it represents the speed of red blood cells d) it represents the convergence of red blood cell lamina e) it determines the ensemble length |
a) it represents the number of red blood cells creating the reflection |
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Which one of the following sets of properties of a test phantom is most relevant when assessing depth calibration accuracy: a) reflector spacing and reflection coefficient b) attenuation and speed of ultrasound in the medium c) reflector spacing and ultrasound attenuation in the medium d) reflector reflection coefficient and ultrasound attenuation in the medium e) reflector spacing and propagation speed |
e) reflector spacing and propagation speed |
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Assuming a constant frequency, what happens if the diameter of an unfocused circular transducer is increased: a) the distance to the far field is reduced b) the beam width in the near field is reduced c) the beam width in the near field is increased d) the ultrasound wavelength is increased e) the sensitivity is reduced |
c) the beam width in the near field is increased |
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From a safety standpoint, which one of the following methods is best: a) low transmit output and high receiver gain b) high transmit output and low receiver gain c) high near gain and low far gain d) low near gain and high far gain e) high reject and high transmitter output |
a) low transmit output and high receiver gain |
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The relative output of an ultrasound instrument is calibrated in dB and the operator increases the output by 60 dB. The beam intensity is increased by which of the following: a) 5% b) two times c) twenty times d) one hundred times e) one million times |
e) one million times |
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What is the most typical Doppler shift measured clinically: a) 3.5 MHz b) 3,500,000 Hz c) 2 kHz d) 1,000 kHz e) 20,000 Hz |
c) 2 kHz |
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True/False: Doppler shifts always occur if the source and receiver are in motion relative to each other. |
False |
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True/False: Doppler shifts always occur if the source and observer are in motion relative to each other and the angle between the motion and the sound beam is 90 degrees. |
False |
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True/False: Doppler shifts always occur if the source and observer are in motion relative to each other and the angle between the motion and the sound beam is not 90 degrees. |
True |
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When the sound source and receiver are not moving directly towards or away from each other, the _______ of the angle between them enters into the calculation of Doppler shift: a) average b) slope c) sine d) cosine |
d) cosine |
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The range equation relates distance from the reflector to ___________ and ____________. a) time-of-flight, distance b) frequency, wavelength c) time-of-flight, propagation speed d) propagation speed, density |
c) time-of-flight, propagation speed |
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In soft tissue: distance traveled = _________ x round trip time a) propagation speed b) wavelength c) period d) PRF |
a) propagation speed |
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With the presence of ________ we see more boundaries than there are reflecting surfaces. a) reverberations b) shadowing c) enhancement d) arrays |
a) reverberations |
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* What is another name for longitudinal resolution: a) axial b) depth c) lateral d) transverse |
a) axial or b) depth |
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What are the units for longitudinal resolution: a) Hz b) Rayls c) m/s d) feet |
d) feet |
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Which of the following is the best lateral resolution: a) 15 mm b) 6 mm c) 0.06 cm d) 2 cm |
c) 0.06 cm |
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If the spatial pulse length is 10 mm, what is the axial resolution: a) 0.5 cm b) 5 cm c) 10 mm d) 1 cm |
a) 0.5 cm |
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If the frequency is decreased, the numerical value of the radial resolution is: a) increased b) decreased c) unchanged |
a) increased |
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A transducer ___________ one form of ____________ into another. |
converts, energy |
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The production of a voltage from deformation is called: a) piezoelectricity b) impedance c) cogeneration d) flux |
a) peizoelctricity |
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Which is not part of a transducer: a) active crystal b) matching layer c) A/D converter d) wire |
c) A/D converter |
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What is the Fraunhofer: a) focus b) near zone c) far zone d) penetration depth |
c) far zone |
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If we increase the frequency, the near zone length is: a) increased b) decreased c) unchanged |
a) increased |
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What is the production of deformation from voltage called: a) piezoelectricity b) impedance c) cogeneration d) flux |
a) piezoelectricity |
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If the transducer diameter increases, the lateral resolution at its smallest dimension is: a) increased b) decreased c) unchanged |
a) increased |
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If we increase the transducer diameter, the beam diameter in the far zone is: a) increased b) decreased c) unchanged |
b) decreased |
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At the focus, the beam diameter is _________ the transducer diameter: a) equal to b) half c) double d) one-fourth |
b) half |
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Lateral resolution can be improved by: a) increasing gain b) decreasing gain c) focusing d) smoothing |
c) focusing |
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True/False: The digital scan converter has a number of pixels assigned to each bit. |
False |
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The more bits per pixel: a) the better the resolution b) the higher the pixel density c) the more shades of gray d) the higher the reliability |
c) the more shades of gray |
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The more pixels per inch: a) the better the temporal resolution b) the better the spatial resolution c) the more shades of gray d) the higher the reliability |
b) the better the spatial resolution |
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Rectification and smoothing are components of which of the following: a) amplification b) decompensation c) reject d) demodulation |
d) demodulation |
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What is the elimination of voltages that do not exceed a certain level: a) amplification b) decompensation c) reject d) demodulation |
c) reject |
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What is the name of the receiver function that corrects for attenuation? |
compensation |
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The process of reducing the difference between the smallest and largest voltages is called? |
compensation |
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If the lines per frame is increased while the imaging depth is unchanged then: a) frame rate increases b) number of shades of gray decreases c) the frame rate decreases d) this cannot happen |
c) the frame rate decreases |
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True/False: A mirror image artifact can appear along side of the true anatomy. |
False |
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Enhancement, multi-path and side lobes result in: a) image distortion b) clearer images c) artifact d) resolution problems |
c) artifact |
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The propagation speed of ultrasound in the AIUM test object is: a) 1 m/s b) 1.54 m/s c) 1.54 mm/us d) 1 km/s |
c) 1.54 mm/us *us = microsecond |
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If wires in an AIUM test object do not appear in the same place as on the display, what is amiss: a) registration accuracy b) dynamic range accuracy c) near gain d) gray scale dynamic range |
a) registration accuracy |
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How many data bits are needed to represent 46 gray shades: a) 46 b) 5 c) 6 d) 8 |
c) 6 |
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The Fresnel is the: a) focus b) near zone c) far zone d) penetration depth |
b) near zone |
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Which of the following is associated with cavitation: a) thermal index b) Snell's law c) Avagadro's number d) mechanical index |
d) mechanical index |
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Which of the following best describes the mechanistic approach to the study of bioeffects: a) cause-effect b) exposure-response c) risk-benefit d) causation-reaction e) effect-microstreaming |
a) cause-effect |
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Which of the following best describes the empirical approach to the study of bioeffects: a) exposure-response b) cause-effect c) risk-benefit d) causation-reaction e) effect-microstreaming |
a) exposure-response |
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The interaction of microscopic bubbles and ultrasound form the basis for cavitation bioeffects. Which of the following forms of cavitation are most likely to produce micro-streaming in the intracelluler fluid and shear stresses: a) stable cavitation b) normal cavitation c) transient cavitation d) inertial cavitation e) active cavitation |
a) stable cavitation |
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The consolidation of many images into a single frame best describes which of the following: a) dynamic range b) fill-in interpolation c) phase quadrature d) persistence |
d) persistence |
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Identify one of the advantages of coded excitation: a) improved contrast resolution b) improved lateral resolution c) improved temporal resolution d) shorter PRP |
a) improved contrast resolution |
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All of the following are true of normal cavitation EXCEPT: a) harmful bioeffects are commonly observed b) it is also known as inertial cavitation c) only a 10% increase in pressure is needed to convert to this from stable cavitation d) temperatures in the thousands of degrees are created e) it is consistent with shock waves |
a) harmful bioeffects are commonly observed |
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Where does coded excitation originate: a) demodulator b) flux capacitor c) transducer d) pulser |
d) pulser |
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Which of the following has the greatest output intensity: a) b-mode b) gray scale imaging c) CW Doppler d) pulsed Doppler |
d) pulsed Doppler |
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You enter a hospital room to perform an ultrasound exam. which of the following should you do first: a) check the room number b) ask a nurse to confirm the patient's name c) ask the patient if they speak english d) check the patient's wristband for identification |
d) check the patient's wristband for identification |
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You enter a patient's room only to find that the patient does not speak english. Which of the following is best to obtain informed consent: a) call for hospital interpreter b) use sign language c) obtain it from a bilingual family member who is in the room d) point to the signature line of the consent form and have the patient sign it |
a) call for hospital interpreter |
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The creation of an image by scanning from different angles best describes: a) spatial compounding b) fill-in interpolation c) phase quadrature d) persistence |
a) spatial compounding |
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What is the meaning of a thermal index = 3 a) tissue temperature may rise 3 degrees Fahrenheit b) tissue temperature will rise 3 degrees Celsius c) tissue temperature may rise 3 degrees Celsius d) microbubbles 3 mm in diameter will burst |
c) tissue temperature may rise 3 degrees Celsius |
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Identify one of the advantages of coded excitation: a) penetration b) improved lateral resolution c) improved temporal resolution d) shorter PRP |
a) penetration |
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Which of these boundaries will create the strongest reflection: a) air-lung b) air-soft tissue c) air-blood d) soft tissue-blood |
b) air-soft tissue |
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Which of these boundaries will create the strongest reflection: a) air-lung b) air-soft tissue c) air-blood d) soft tissue-blood |
d) soft tissue-blood |
