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160 Cards in this Set
- Front
- Back
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(1)What is the vertical axis of a graph called?
A. z-axis B. x-axis C. y-axis D. time-axis |
(2) What is the name of the horizontal axis of a graph?
A. z-axis B. x-axis C. y-axis D. red axis |
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(3)How are scores on the ultrasound board exams related to a studying time?
A. inversely B. conversely C. directly D. unrelated |
(4)How is weight related to a sonographer's time spent exercising?
A. inversely B. conversely C. directly D. unrelated |
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(5)How are caloric intake and weight related?
A. inversely B. partially C. reciprocally D. directly |
(6)What is the reciprocal of 1,000?
A. one-hundredth B. 1,000 C. 0.001 D. one-millionth |
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(7)What is the reciprocal of 5?
A. one-hundredth B. 5 C. 1/5 D. one-millionth |
(8)What is the reciprocal of 1/10?
A. one-hundredth B. 10 C. 1/10 D. one-millionth |
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(9)A sack contains 6 pounds of flour. The contents of the bag are increased by a factor of 5. How much flour is in the bag?
A. 6 pounds B. 11 pounds C. 60 pounds D. 30 pounds |
(10)A bouquet has 30 flowers. The size of the bouquet is decreased by a factor of 3. How many flowers remain?
A. 27 B. 0 C. 10 D. 15 |
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(11)How much bigger is one billion than one thousandth?
A. 1,000 times B. 1,000,000 times C. 10 times D. 10,000 times |
(12)Select the sequence that appears in INCREASING order.
A. mega,kilo,hecto,milli,giga B. nano,milli,micro,deci,deca, mega C. centi,deci,deca,hecto D. milli,hecto,centi,deci, nano,giga |
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(13)How many nanoseconds are in 7 seconds?
A. 7,000,000 B. 7,000,000,000 C. 7 million D. 0.00000007 |
(14)The letters below represent the abbreviations for the prefixes of the metric system. Select the sequence that appears in DECREASING order.
A. m, k, M, g, da B. g, m, k, d, µ C. g, k, di, m, µ, n D. M, k, da, d, c |
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(15)Match the following prefixes with their meanings.
A. mega 1. hundredths B. hecto 2. thousands C. milli 3. thousandths D. kilo 4. millions E. nano 5. billions F. giga 6. billionths |
(16)Which term is the reciprocal of Mega?
A. nano B. kilo C. macro D. micro |
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(17)Which of the following is not a measure of area?
A. square cm B. meters squared C. cubic meters D. feet x feet |
(18)A sonographer measures the perimeter of an anatomical structure. Which of the following choices is a reasonable value for the measurement?
A. 6 cm² B. 5 cc C. 15 mm D. 18 dB |
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(19)What are the units associated with the circumference of a circle?
A. mm B. mm² C. cm³ D. m^4 |
(20)The volume of a cystic structure is estimated from sonographic data. Which of the following is an acceptable measurement of this volume?
A. 6 B. 6 cm C. 6 cm² D. 6 cm³ |
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(21)How can the volume of an irregularly shaped object be most accurately measured?
A. by visual inspection B. by its weight C. by immersing it in water D. by ultrasound scanning |
(22)The speed of RBC's traveling through a blood vessel is 750 cm/sec. You are asked to measure this speed in mph. What information would be sufficient for you to complete your task?
A. how many sec in a minute & how many blood cells in the vessel B. the number of miles in a meter C. how many sec per hour & the number of miles in a cm D. the direction of RBC motion & the Doppler shift frequency |
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(23)What term is used to describe the effects of an ultrasound wave on living tissues?
A. toxic effects B. acoustic prop. properties C. biological effects D. transmission properties |
(24)As sound travels through a medium, what term describes the effects of the medium on the sound waves?
A. A. toxic effects B. acoustic prop. properties C. bioeffects D. transmission properties |
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(25)Sound can be characterized as?
A. energy flowing through a vacuum B. a variable C. cyclical oscillations in certain variables D. a principle of acoustics |
(26)Which of the following is true of all waves?
A. they travel through a medium B. all carry energy from one site to another C. their amp do not change D. they travel in a straight line |
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(27) A longitudinal wave is propagating from the East toward the West at a speed of 2 mph. What is the direction of motion of the particles within the wave?
A. from the East to the West only B. alternately from East to West & then from West to East C. from North to South only D. alternately from South to North & then from North to South |
(28)The direction of motion of a particle in a wave is perpendicular to the direction of propagation of the wave. What type of wave is this?
A. longitudinal B. acoustic C. mechanical D. transverse |
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(29)A particle within a transverse wave is traveling vertically. What is the direction of the wave's propagation?
A. horizontal B. vertical C. diagonal; both horizontal & vertical D. cannot be determined |
(30)Which of the following types of waves do not require a medium in order to propagate? (More than 1 answer may be correct)
A. light B. heat C. sound D. television |
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(31)Which of the following describes the characteristics of a sound wave?
A. longitudinal,non-mechanical B. mechanical, transverse C. transverse, acoustic D. mechanical, longitudinal |
(32)Sound is best described as ______.
A. a series of compressions and rarefactions B. a transverse wave C. a wave that humans can hear D. an oblique displacement of acoustic energy |
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(33)All of the following are true about sound waves EXCEPT:
A. they are mechanical B. they are transverse C. they carry energy from place to place D. they generally travel in a straight line |
(34)TRUE OR FALSE; frequency is an acoustic variable?
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(35)TRUE OR FALSE; pressure is an acoustic variable?
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(36)TRUE OR FALSE; propagation speed is an acoustic variable?
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(37)TRUE OR FALSE; wavelength is an acoustic variable?
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(38)TRUE OR FALSE; voltage is an acoustic variable?
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(39)TRUE OR FALSE; intensity is an acoustic variable?
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(40)TRUE OR FALSE; motion of particles in the wave is an acoustic variable?
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(41)TRUE OR FALSE; density is an acoustic variable?
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(42)What are the units of a pressure measurement of an acoustic wave? (more than 1 answer may apply)
A. atmospheres, (atm) B. pascals (Pa) C. millimeters of mercury (mmHg) D. pounds/sq. inch (lb/in)² |
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(43)A force is applied to a surface. If the force is tripled and the surface area over which the force is applied is also tripled, what is the new pressure?
A. three times larger than the original B. one third of the original C. six times more than the original D. unchanged |
(44)Which of the following units are appropriate to describe the period of an acoustic wave? (more than 1 answer may be correct)
A. minutes B. microseconds C. meters D. mm/µs |
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(45)Waves that exist at the same location and time will combine together. what is this called?
A. inference B. rarefaction C. interference D. longitudinal interaction |
(46)Two waves arrive at the same location and interfere. The resultant sound wave is smaller than either of the two original waves. What is this called?
A. constructive interference B. angular interaction C. destructive interference D. in-phase waves |
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(47)A pair of waves are in phase. What occurs when these waves interfere?
A. reflection B. constructive interference C. refraction D. destructive interference |
(48)_________ is the reciprocal of period.
A. inverse period B. pulse repetition period C. frequency D. propagation period |
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(52)What is the range of periods commonly found in waves produced by ultrasound systems?
A. 0.001 to 1 s B. 0.1 to 0.5 µs C. 0.2 to 1 ms D. 10 to 100 ns |
(53)With standard ultrasonic imaging, what happens to the period of a wave as it propagates?
A. increases B. decreases C. remains the same |
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(54)TRUE OR FALSE? If the periods of two waves are the same, then the frequencies of the waves must also be the same.
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(55)TRUE OR FALSE? The sonographer has the ability to alter the period of an ultrasound wave that is produced by a basic transducer.
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(56)What determines the period of an ultrasound wave?
A. the transducer B. the medium through which the sound travels C. both A and B D. neither choice A nor B |
(57)What term describes the number of cycles that an acoustic variable completes in a second?
A. period B. frequency C. pulse repetition period D. variable rate |
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(58)Which of the following cannot be considered a unit of frequency?
A. per day B. cycles/sec C. Hz D. hertz E. cycles |
(59)What is the range of frequencies emitted by transducers used in ultrasonic imaging?
A. 1 to 3 MHz B. 1 to 1,000 kHz C. -10,000 to +10,000 Hz D. 2,000,000 to 10,000,000 Hz |
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(60)What establishes the frequency of an ultrasound wave?
A. the transducer B. the medium through which the sound travels C. both A and B D. neither choice A and B |
(61)TRUE OR FALSE? With standard ultrasound pulses, the frequency of the ultrasound changes significantly as the wave propagates through the body.
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(62)Ultrasound is defined as a sound with a frequency of ___.
A. greater than 20,000 kHz B. less than 1 kHz C. greater than 10 MHz D. greater than 0.02 MHz |
(63)Infrasound is defined as a sound with a frequency of ____.
A. greater than 20,000 kHz B. less than 20 Hz C. greater than 10 MHz D. less than 0.02 MHz |
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(64)TRUE OR FALSE? Waves in the ultrasound range behave in the same general manner as sound waves that are audible.
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(65)What is characteristics of acoustic waves with frequencies exceeding 20,000 Hz when compared with waves having frequencies of less than 20,000 Hz?
A. they travel more effectively in soft tissue B. they travel more rapidly C. they attenuate less when traveling in soft tissue D. humans can't hear them |
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(66)What is characteristic of acoustic waves with frequencies less than 20 Hz when compared with waves having frequencies of more than 20 Hz?
A. they travel less effectively in soft tissue B. they travel more rapidly C. they attenuate more when traveling in soft tissue D. humans can't hear them |
(67)Compare two sound waves, A and B. The frequency of wave A is one-third that of wave B. How does the period of wave A compare with the period of wave B?
A. A is one-third as long as B B. A is the same as wave B C. A is three times as long as B D. cannot be determined |
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(68)Which of the following waves is ultrasonic and least useful in diagnostic ultrasound?
A. 2 MHz B. 2,000 Hz C. 24 kHz D. 7.5 MHz |
(69)What determines the initial amplitude of an ultrasound wave?
A. the transducer B. the medium through which the sound travels C. both A and B D. neither choice A nor B |
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(70)TRUE OR FALSE? With standard diagnostic imaging instrumentation, the sonographer has the ability to vary the amplitude of a sound wave produced by the transducer.
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(71)As an ultrasound wave travels through the body, its amplitude usually:
A. decreases B. increases C. remains the same D. cannot be determined |
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(72)Which of the following are acceptable units fro the amplitude of an acoustic wave? (more than 1 answer may apply)
A. cm B. atmospheres C. gauss D. watts |
(73)The maximum value of the density of an acoustic wave is 60 lb/in² while the minimum density is 20 lb/in². What is the amplitude of the wave?
A. 20 lb/in² B. 40 lb/in² C. 60 lb/in² D. none of the above |
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(74)The power of an ultrasound wave can be reported with which of the following units? (more than 1 answer may apply)
A. watts/square centimeter B. dB/cm C. watts D. kg/cm² |
(75)Typically, as an ultrasound wave travels though soft tissue, the power of the wave:
A. decreases B. increases C. remains the same |
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(76)TRUE OR FALSE? A sonographer can routinely change the power of a wave emitted by a transducer used in diagnostic ultrasonic imaging.
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(77)Mathematically, when a number is squared, the number is multiplied by:
A. 2 B. 0.5 C. itself D. 1.5 |
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(78)The final amplitude of an acoustic wave is reduced to one-half of its original value. The final power is ___ the original power.
A. the same as B. one-half C. double D. none of the above |
(79)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?
A. 3 watts B. 9 watts C. 1 watt D. none of the above |
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(80)The intensity of an ultrasound beam is defined as the ___ in a beam ___ by the ____ of the beam.
A. power, multiplied, diameter B. amplitude, divided, area C. power, divided, area D. amplitude, multiplied, circumference |
(81)As sound travels in the body, what typically happens to the intensity of the wave?
A. increases B. decreases C. remains the same |
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(82)What are the units of intensity?
A. watts B. watts/cm C. watts/cm² D. dB |
(83)If the power in an ultrasound beam is unchanged, while at the same time, the beam area doubles, then the beam's intensity:
A. doubles B. is halved C. is quartered D. remains the same |
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(84)What happens to an acoustic beam's intensity when the power in the beam increases by 25% while the cross-sectional area of the beam remains the same?
A. it increases by 25% B. increases by 75% C. it increases by 50% D. decreases by 25% |
(85)TRUE OR FALSE? With diagnostic ultrasonic imaging instruments, the operator can alter the intensity of an ultrasound beam produced by a transducer.
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(86)When the power in an acoustic beam is doubled and the cross-sectional area of the beam is halved, then the intensity of the beam is:
A. doubled B. halved C. quartered D. four times larger |
(87)What determines the initial intensity of an ultrasound beam?
A. the source of the sound wave B. the medium through which the sound travels C. both A and B D. neither choice A nor B |
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(89)What happens to the intensity of an ultrasound beam when the beam's cross-sectional area remains unchanged while the amplitude of the wave triples?
A. it triples B. increases ninefold C. remains the same D. none of the above |
(90)If the power of the beam is tripled while the cross-sectional area of the beam remains the same, the intensity ___
A. triples B. increases ninefold C. remains the same D. none of the above |
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(91)The amplitude of an acoustic wave is increased. Which of the following will most likely remain unchanged? (more than 1 answer may apply)
A. power B. frequency C. period D. intensity |
(92)The wavelength of a cycle in an ultrasound wave can be reported with which units?
A. units of time (sec,min,etc) B. units of distance (feet,etc) C. units of area (m², etc) D. mm only |
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(93)The wavelength of an ultrasonic wave is determined by:
A. the sound source B. the medium through which the wave travels C. both A and B D. neither A nor B |
(94)What is the best estimate of the distance that sound can travel in soft tissue in one second?
A. one yard B. one hundred yards C. one mile D. ten miles |
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(95)What is the wavelength of 2 MHz sound in soft tissue?
A. 0.77 mm B. cannot be determined C. 1.54 mm D. 2 mm |
(96)Which of the following terms best describes the relationship between frequency and wavelength for sound traveling in soft tissue?
A. reciprocal B. direct C. related D. inverse |
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(97)TRUE OR FALSE? Lower frequency sound creates higher quality images with greater detail.
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(98)TRUE OR FALSE? Shorter wavelength sound creates higher quality images with greater detail.
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(99)What is the wavelength of 10 MHz sound in soft tissue?
A. 0.77 mm B. 0.15mm C. 1.54 mm D. 10 mm |
(100)TRUE OR FALSE? The frequency of the wave increases as it travels through the mass.
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(101)TRUE OR FALSE? The period of the sound wave decreases as it travels through the mass.
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(102)TRUE OR FALSE? The wavelength increases while the wave travels through the mass.
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(103)TRUE OR FALSE? The power in the wave increases as it travels through the mass.
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(104)Propagation speed can be correctly recorded with which of the following units? (more than 1 answer may apply)
A. miles per hour B. mm/msec C. km/sec D. inches per year |
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(105)The speed of sound traveling through bone is ____ soft tissue.
A. higher than B. lower than C. equal to D. cannot be determined |
(106)Compared to soft tissue, the speed of an acoustic wave through lung tissue is ____.
A. faster B. slower C. equal D. cannot be determined |
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(107)What is the best estimate for the speed of sound in tendon?
A. 1,000 m/s B. 1,540 m/s C. 1,754 m/s D. 5,400 m/s |
(108)As a general rule, which of the following lists media in increasing order of propagation speeds?
A. gas, solid liquid B. liquid, solid, gas C. solid, liquid, gas D. gas, liquid, solid |
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(109)What is the speed of sound in air?
A. 1,540 m/s B. 330 m/s C. 100 m/s D. 3,010 m/s |
(110)TRUE OR FALSE? Soft tissue is an imaginary construct that actually does not exist.
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(111)What is the propagation speed of a 5 megahertz sound wave in soft tissue?
A. 1,450 meters per sec B. 1,540 km/sec C. 1.54 m/s D. 1.54 mm/µs |
(112)The speed at which a wave travels through a medium is determined by:
A. the sound wave's properties only B. the medium's properties only C. properties of both wave and medium D. none of the above |
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(113)What two properties establish sound's propagation speed in a given medium?
A. elasticity and stiffness B. stiffness and impedance C. conductance and density D. density and stiffness |
(114)The characteristics of four media are described below. Which of the media has the slowest propagation speed?
A. high density and high elasticity B. low density and high stiffness C. low stiffness and low density D. low compressibility and low stiffness |
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(116)When the elasticity of a medium is high, the __ is high.
A. stiffness B. propagation speed C. compressibility D. reflectivity |
(117)Two sound waves with frequencies of 5 and 3 MHz, travel to a depth of 8 cm in a medium and then reflect back to the surface of the body. Which acoustic wave arrives first at the surface of the body?
A. the 5 MHz wave B. the 3 MHz wave C. neither D. cannot be determined |
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(118)If sound travels at exactly 1,540 m/sec in a particular medium, then the medium ____.
A. must be soft tissue B. may be soft tissue C. cannot be soft tissue |
(119)If sound doesn't travel at 1,540 m/sec in a medium, then the medium ____.
A. must be soft tissue B. may be soft tissue C. cannot be soft tissue |
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(120)The propagation speeds of ultrasound waves in muscle, liver, kidney and blood are _____.
A. exactly the same B. very similar to each other C. vastly different |
(121)Two sound pulses travel through the same medium. One wave's frequency is 2 MHz and the other is 10 MHz. Which pulse has a longer wavelength?
A. the 10 MHz pulse B. the 2 MHz pulse C. neither pulse D. cannot be determined |
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(122)Two sound pulses travel through the same medium. One wave's frequency is 2 MHz and the other is 10 MHz. Which pulse has a lower propagation speed?
A. the 10 MHz pulse B. the 2 MHz pulse C. neither pulse D. cannot be determined |
(123)Two sound pulses travel through the same medium. One wave's frequency is 2 MHz and the other is 10 MHz. Which sound wave has a longer period?
A. the 10 MHz pulse B. the 2 MHz pulse C. neither pulse D. cannot be determined |
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(124)Two sound pulses travel through the same medium. One wave's frequency is 2 MHz and the other is 10 MHz. Which pulse has a longer spatial pulse length?
A. the 10 MHz wave B. the 2 MHz wave C. neither wave D. cannot be determined |
(126)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. TRUE OR FALSE? The waves travel through all three media at the same speed since they have identical frequencies.
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(127)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. TRUE OR FALSE? The sound waves travel through all three media at different speeds because the waves have different powers.
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(128)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. TRUE OR FALSE? The waves travel through all three media at different speeds because the media are different.
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(129)Two waves, a 5 MHz ultrasonic wave and a 5 kHz audible wave, travel through soft tissue. TRUE OR FALSE? The ultrasound wave travels much faster than the audible wave.
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(130)Two waves, a 5 MHz ultrasonic wave and a 5 kHz audible wave, travel through soft tissue. TRUE OR FALSE? Both the 5 MHz and the 5 kHz waves travel at similar speeds through the medium.
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(131)Two waves, a 5 MHz ultrasonic wave and a 5 kHz audible wave, travel through soft tissue. TRUE OR FALSE? The wavelength of the 5 MHz wave is greater than the wavelength of the 5 kHz wave.
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(132)Two waves, a 5 MHz ultrasonic wave and a 5 kHz audible wave, travel through soft tissue. TRUE OR FALSE? The period of the 5 MHz wave is less than the period of the audible wave.
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(133)What are the units of pulse duration?
A. units of frequency (Hz,etc) B. msec only C. units of time (sec,years,etc) D. units of distance (feet,etc) |
(134)What determines the pulse duration?
A. the source of the wave B. the medium in which the pulse travels C. both A and B D. neither A and B |
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(135)Two pulses are created by different transducers. Both have the same number of cycles. The pulse containing cycles of a lower frequency has a ____.
A. lower pulse repetition frequency B. shorter pulse duration C. longer pulse duration D. longer pulse repetition period |
(136)Two pulse are created by different transducers. Both waves have the same frequency. The pulse containing more cycles has a ____.
A. lower pulse repetition frequency B. shorter pulse duration C. longer pulse duration D. longer pulse repetition period |
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(137)Two pulses are created by different transducers. The pulses have different durations. Which pulse is likely to create the best image?
A. the shorter duration pulse B. the longer duration pulse C. the qualities will be the same |
(138)The pulse duration is expressed in the same units as the _____.
A. period B. PRF C. wavelength D. density |
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(139)TRUE OR FALSE? A sonographer can adjust the duration of an acoustic pulse since it depends upon the pulse's propagation speed.
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(140)TRUE OR FALSE? A sonographer can adjust the duration of an acoustic pulse since it depends upon the maximum imaging depth.
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(141)TRUE OR FALSE? The sonographer cannot change the duration of a sound pulse unless the transducers are switched.
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(142)TRUE OR FALSE? The pulse duration cannot be changed under any circumstances or by any action of the sonographer.
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(143)What is the pulse duration equal to?
A. frequency multiplied by period B. period multiplied by wavelength C. the number of cycles in the pulse divided by the wavelength D. period multiplied by the number of cycles in the pulse |
(144)The spatial pulse length describes certain characteristics of an ultrasound pulse. What are its units?
A. time B. hertz C. meters D. none; it is unitless |
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(145)In diagnostic imaging, what determines the spatial pulse length?
A. the ultrasound system B. the medium through which the pulse travels C. both A and B D. neither A nor B |
(146)Which of the following best describes the spatial pulse length?
A. frequency multiplied by wavelength B. PRF multiplied by wavelength C. wavelength multiplied by the number of cycles in the pulse D. duty factor multiplied by the wavelength |
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(147)Two transducers send ultrasound pulses into soft tissue. One transducer emits sound with a 4 MHz frequency, and the other produces sound at 6 MHz frequency. Each pulse contains 4 cycles. Which has a greater spatial pulse length?
A. the 6 MHz pulse B. the 4 MHz pulse C. they are the same D. cannot be determined |
(148)Using a specific transducer, what happens to the spatial pulse length as the sonographer increases the maximum imaging depth?
A. increases B. decreases C. remains the same D. cannot be determined |
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(149)TRUE OR FALSE? While imaging soft tissue, the spatial pulse length does not change as long as the components of the ultrasound system are the same.
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(150)Which of the following is a correct description of pulse repetition period?
A. the product of wavelength and propagation speed B. the reciprocal of the frequency C. the sum of the pulse's "on" time and the listening "off" time D. the time that the transducer is pulsing |
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(151)What happens to the pulse repetition period if the sonographer decreases the maximum imaging depth achieved in an ultrasound scan?
A. increases B. decreases C. remains the same D. cannot be determined |
(152)What happens to the pulse duration when a sonographer decreases the maximum imaging depth in an ultrasound scan?
A. increases B. decreases C. remains the same D. cannot be determined |
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(153)The characteristics of a pulse are as follows: the pulse repetition period is 1000 µsec and the listening or dead time is 998 µsec. What is the pulse duration?
A. 1950 µsec B. 2 msec C. 2 µsec D. 0.95 |
(154)What are the units of pulse repetition frequency (PRF)?
A. seconds B. 1/seconds C. mm/µs D. seconds¯² |
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(155)The pulse repetition frequency of ultrasound produced by a transducer typical of diagnostic imaging systems ___.
A. can be changed by the sonographer B. depends on the medium through which th sound travels C. is unchanged as long as the same ultrasound system is used D. has nothing to do with clinical imaging |
(156)In diagnostic imaging, what establishes the pulse repetition frequency?
A. the source of the sound B. the medium through which the sound travels C. both A and B D. neither A nor B |
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(157)When a sonographer increases the maximum imaging depth during an exam, what happens to the PRF?
A. PRF increases B. PRF decreases C. remains unchanged |
(158)When a sonographer increases the maximum imaging depth during an exam, what happens to the frequency?
A. frequency increases B. frequency decreases C. remains unchanged |
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(159)TRUE OR FALSE? The pulse repetition frequency and the frequency are unrelated.
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(160)The pulse repetition frequency is the ______.
A. product of the wavelength and propagation speed B. reciprocal of the period C. sum of pulse duration and listening time D. reciprocal of pulse repetition period |
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(161)Two ultrasound systems, one producing sound with a frequency of 3 MHz and the other at 6 MHz, are used to image a patient. The maximum imaging depth of both exams is 8 cm.TRUE OR FALSE? The pulses produced by both systems travel at the same speed in the patient.
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(162)Two ultrasound systems, one producing sound with a frequency of 3 MHz and the other at 6 MHz, are used to image a patient. The maximum imaging depth of both exams is 8 cm.TRUE OR FALSE? The PRF of the 6 MHz transducer is greater than the PRF of the 3 MHz transducer.
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(163)Two ultrasound systems, one producing sound with a frequency of 3 MHz and the other at 6 MHz, are used to image a patient. The maximum imaging depth of both exams is 8 cm.TRUE OR FALSE? The period of the 3 MHz sound is greater than the period of the 6 MHz sound.
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(164)Two ultrasound systems, one producing sound with a frequency of 3 MHz and the other at 6 MHz, are used to image a patient. The maximum imaging depth of both exams is 8 cm.TRUE OR FALSE? The wavelength of the 3 MHz ultrasound is greater than the 6 MHz sound.
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(165)On what does the pulse repetition period depend?
A. the source of the sound wave B. the medium through which the pulse travels C. both A and B D. neither A nor B |
(166)A sonographer adjusts the output power of the wave emitted by the transducer. Which of the following also changes? (more than 1 answer may apply).
A. pulse repetition period B. PRF C. propagation speed D. intensity |
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(167) A sonographer adjusts the maximum imaging depth of an ultrasound system. Which of the following also changes? (more than 1 answer may be correct)
A. pulse repetition period B. wavelength C. pulse repetition frequency D. frequency |
(168) What is a typical value for the duty factor (also called the duty cycle) of pulsed sound wave used in diagnostic imaging?
A. 0.001 msec B. 0.001 kg/cm³ C. 0.75 D. 0.001 |
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(169)What is the value of the duty cycle for continuous wave ultrasound?
A. 100 B. 1% C. 1000% D. none of the above |
(170) In the case of pulsed ultrasound, what is the maximum value of the duty factor?
A. 100% B. 1 C. less than 100% D. none of the above |
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(171)While using a particular imaging system, what happens to the duty factor when the depth of view increases?
A. increases B. decreases C. unchanged |
(172)TRUE OR FALSE? The sonographer alters the duty cycle when adjusting the maximum imaging depth of a scan.
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(173) TRUE OR FALSE? The duty factor is a characteristic of an ultrasound and transducer system and does not change as long as the system components remain unchanged.
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(174)TRUE OR FALSE? The pulse duration of an ultrasound and transducer system does nt change significantly as long as the system components remain unchanged.
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(175)What is the duty factor if the pulse duration is 1 microsecond and the pulse repetition period is 1 millisecond?
A. 0.1 B. 0.01 C. 0.001 D. 0.0001 |
(176)What is the duty factor of a wave that has a pulse repetition period of 30 microseconds and a pulse duration of 0.3 microseconds?
A. 0.03 B. 0.90 C. 30.3 D. 0.01 |
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(!77)The maximum imaging depth during an exam is unchanged. A new transducer with a longer pulse duration is used. TRUE OR FALSE? The pulse repetition period is increased.
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(178)The maximum imaging depth during an exam is unchanged. A new transducer with a longer pulse duration is used. TRUE OR FALSE? The pulse repetition frequency is increased.
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(179)The maximum imaging depth during an exam is unchanged. A new transducer with a longer pulse duration is used. TRUE OR FALSE? The duty factor is increased.
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(180))The maximum imaging depth during an exam is unchanged. A new transducer with a longer pulse duration is used. TRUE OR FALSE? The frequency is increased.
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(181)While using the same ultrasound machine and transducer, which of the following can a sonographer alter? (more than 1 answer may apply).
A. pulse repetition period B. PRF C. frequency D. duty cycle E. pulse duration |
(182)The propagation speed of continuous wave ultrasound is 1.8 kilometers per second. The wave is then pulsed with a duty factor of 50%. What is the new propagation speed?
A. 0.5 km/sec B. 0.9 km/sec C. 1.8 km/sec D. 3.6 km/sec E. cannot be determined |
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(183)The frequency of a continuous acoustic wave is 5 MHz. The wave is then pulsed with a duty factor of 0.1. What is the new frequency?
A. 0.5 B . 0.5 MHz C. 5 MHz D. 10 MHz |
(184)TRUE OR FALSE? The period of an ultrasound wave is related to the frequency and is the same, regardless of whether the wave is pulsed or continuous.
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(185)TRUE OR FALSE? The wavelength of an acoustic wave is shorter when it is pulsed rather than continuous.
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(186)Which of the following terms does not belong with the others?
A. increased depth of view B. increased duty factor C. increased pulse repetition period D. decreased pulse repetition frequency |
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(187)Which of the following terms does not belong with the others?
A. increased depth of view B. decreased duty factor C. increased pulse repetition period D. decreased spatial pulse length |
(188)The term Im defines the _______ and has units of _____.
A. medium's maximum impedance, Rayls B. transducer's minimum input, watts C. maximum intensity, watts/cm² D. minimum inductance, Rayls/sec |
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(189)With a continuous wave sound beam, which of the following 4 intensities are the same?
1)SPTA 2)SAPA 3)SATA 4)Im A. 1 and 2 B. 1 and 3 C. 1 and 4 D. 2 and 3 |
(190)The SPTP intensity of a typical pulsed acoustic wave _____.
A. exceeds the SATA intensity B. exceeds the SPTA intensity C. exceeds the SATP inensity D. all of the above |
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(191)What is another name for the beam uniformity coefficient?
A. duty cycle B. attenuation coefficient C. SP/SA factor D. beam impedance ratio |
(192)What does the beam uniformity coefficient (also called SP/SA factor) measure?
A. special distribution of sound energy B. spatial distribution of acoustic energy C. temporal distribution of sound energy D. none of the above |
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(193)Which of the following values can correctly designate both the duty cycle and the beam uniformity coefficient?
A. 1% B. 0 C. 100% D. none of the above |
(194)What is the importance of describing sound beam intensities in a variety of ways with regard to space and time?
A. it allows better transducer design B. it's important when studying bioeffects C. it optimizes image quality D. harmonics can be measured |
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(195)What are acceptable units for the beam uniformity coefficient?
A. mW B. mW/cm² C. cm D. none of the above |
(196)Two acoustic beams have identical SPTP intensities of 400 mW/cm². One beam is pulsed while the other is continuous wave. Which beam has a higher SPTA intensity?
A. the pulsed beam B. the continuous beam C. neither D. cannot be determined |
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(197)Which intensity is most closely correlated to tissue heating?
A. SPTP B. SATP C. SPTA D. SATA |
(198)The logarithm of a numeral is defined as how many times ____ must be multiplied together to get that numeral.
A. 1 B. 2 C. 5 D. 10 |
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(199)What is a decibel?
A. the absolute value of a number B. a range of values C. a relationship between two numbers D. none of the above |
(200)Decibel notation is a ____ between two numbers.
A. difference B. sum C. product D. ratio |
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(201)What is the decibel representation when an acoustic signal is amplified?
A. positive B. negative C. equal to zero |
(202)What is the decibel notation for an acoustic signal that is attenuated?
A. positive B. negative C. equal to zero |
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(203)The intensity of a signal declines from 1.5 mW/cm² to 0.75 mW/cm². How many decibels is this change in intensity?
A. 3 dB B. 0.75 dB C. -0.75 dB D. -3 dB |
(204)The power in a wave is increased to ten times its original value. How many decibels describe this change?
A. 3 B. 6 C. 10 D. 20 |
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(205)How many decibels represent a 100-fold increase in the intensity of an acoustic pulse?
A. 10 B. 20 C. 100 D. 6 |
(206)The intensity of an ultrasound wave is changed by -6 dB. This means that the current intensity is ____ as much as its original level.
A. one-tenth B. four times C. one-fourth D. one-sixth |
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(207)Which of the following reports the relative strength of an ultrasound wave?
A. decibels B. watts C. w/cm² D. pascals |
(208)The scale associated with the decibel notation is _______.
A. linear B. discrete C. logarithmic D. additive |
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(209)What units are used to describe attenuation?
A. watts B. watts/cm² C. macro D. decibels |
(210)What does a 3 dB change in a value intensity mean?
A. the value has doubled B. the value has tripled C. the value has increased 30% D. the value has increased ten times |
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(211)As sound propagates through a medium, the total power in the wave decreases. What is the entire process called?
A. absorption B. scattering C. attenuation D. reflection |
(212)Attenuation is determined by which of the following factors?
A. density and stiffness of the medium B. frequency of sound and propagation speed C. PRF of sound and path length D. path length and frequency of sound |
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(213)An acoustic wave is traveling through soft tissue. Its intensity undergoes six decibels of attenuation. How does the final intensity of the wave relate to the intensity of the wave when it started its journey?
A. it is now four times larger B. it is now six times larger C. it is now one-fourth as large D. it is now one-tenth as large |
(214)Which of the following is not one of the physical processes that contribute to attenuation of ultrasound waves passing through soft tissue?
A. reflection B. redirection of sound in many directions C. focusing D. conversion of acoustic energy to heat |
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(215)As a pulse passes through soft tissue, a certain amount of acoustic energy remains in the tissue as heat. What is this constituent of attenuation called?
A. scattering B. absorption C. refraction D. rarefaction |
(216)What is the dispersion of a sound wave uniformly in many different directions after striking a very small particle?
A. microscattering B. backscattering C. Rayleigh scattering D. total absorption |
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(217)Which of the following is considered a Rayleigh scatterer?
A. bone B. liver C. muscle D. blood |
(218)To which of the following is Rayleigh scattering related?
A. half of the wavelength B. square root of propagation speed C. frequency^4 D. PRF² |
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(219)A sound wave reaches a rough or irregular border between two media. Under these explicit circumstances, which process is most likely to occur?
A. backscatter reflection B. specular reflection C. Rayleigh scattering D. refraction |
(220)Which of the following is true of diffuse reflection?
A. they're created by smooth boundaries B. they're created by large reflectors C. sound reflects in many directions D. they do not appear in soft tissue |
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(221)An acoustic pulse reflects from a very smooth boundary where the irregularities on the surface of the boundary are much smaller than the pulse's wavelength. What type of reflection is most likely to occur under these circumstances?
A. partial B. Rayleigh C. specular D. total |
(222)What is the amount of attenuation per centimeter that a sound wave undergoes called?
A. beam uniformity coefficient B. attenuation coefficient C. attenuation D. duty factor |
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(223)A sound beam travels 9 cm in soft tissue. The attenuation coefficient is 3 dB/cm. What is the total attenuation that the sound beam experienced?
A. 9 dB B. 3 dB C. 27dB D. 18 dB |
(224)An 8 MHz sound beam travels in soft tissue though a path length of 5 cm. What is the value of the attenuation coefficient?
A. 8 dB/cm B. 20 dB/cm C. 4 dB/cm D. 40 dB/cm |
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(225)An 8 MHz sound beam travels in soft tissue though a path length of 5 cm. What is the value of the attenuation?
A. 8 dB B. 20 dB C. 4 dB D. 40 dB |
(226)The half value layer is the thickness of tissue where sound attenuates by _______ dB.
A. 3 dB B. 6 dB C. 1/2 dB D. 10 dB |
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(227)Half value layer depends upon which of these features?
A. path length and frequency B. path length and propagation speed C. medium and frequency D. PRF and medium |
(228)The attenuation of an acoustic wave traveling through bone is ____ its attenuation through soft tissue.
A. greater than B. less than C. equal to |
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(229)Ultrasound waves traveling through lung tissue attenuate to a ____ extent than when traveling though soft tissue.
A. greater B. lesser C. nearly equal |
(230)Sound traveling through blood attenuates to a ____ extent than when traveling through soft tissue.
A. greater B. lesser C. relatively equal |
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(231)Which of these lists indicates media with increasing attenuation of ultrasound?
A. water, lung, soft tissue, bone, air B. lung, air, soft tissue, bone C. lung, fat muscle D. water, blood, fat, muscle, bone, air |
(232)TRUE OR FALSE? Attenuation and propagation speed are unrelated.
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(233)Acoustic impedance is a property of the ____ and has units of ____.
A. source and medium, Imps B. medium, dB C. medium, Rayls D. medium, Ohms |
(234)TO calculate the acoustic impedance of a medium, one should ____ the ____ by the ____.
A. divide, propagation speed, density B. multiply, density, propagation speed C. divide, density, propagation speed D. multiply, stiffness, density |
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(235)Which of two attributes help establish the acoustic impedance of a medium?
A. density and temperature B. density and stiffness C. stiffness and elastance D. elasticity and compressibility |
(236)Which value is closest to the impedance of soft tissue?
A. 1.5 kiloRayls B. 2.5 deciRayls C. 19 megaRayls D. 2,000,000 Rayls |
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(237)Which of the following describes an angle with a measure of 45°?
A. orthogonal B. acute C. obtuse D. normal |
(238)Which of the following describes an angle with a measure of 123°?
A. orthogonal B. acute C. obtuse D. normal |
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(239)The angle between the direction of propagation and the boundary between two media is 90°. What term decribes the form of incidence of the wave?
A. not normal B. direct C. oblique D. orthogonal |
(240)Which term does not belong in the group below?
A. orthogonal B. at right angles C. oblique D. 90° E. normal F. perpendicular |
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(241)A sound wave strikes a boundary between two media at a 60° angle. This is called ____ incidence.
A. orthogonal B. angular C. obtuse D. oblique |
(242)Which term has a meaning other than normal incidence?
A. orthogonal incidence B. perpendicular incidence C. oblique incidence |
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(243)If the ____ of two media are different and sound strikes a border between the media at 90° incidence, then reflection will occur.
A. conductances B. densities C. impedances D. propagation speeds |
(244)TRUE OR FALSE? The propagation of the incidence intensity that is reflected at a border between two media will increase as the impedances of the media become increasingly dissimilar.
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(245)A sound pulse strikes a boundary between two media with normal incidence. The speed of sound in the two media are very different; however, the impedances of the media are identical. What will happen?
A. a big echo will be produced B. a medium echo will result C. a small echo will result D. there will be no echo at all |
(246)Two acoustic waves strike a boundary between two media. The waves are traveling in a direction 90° to the boundary. Reflection of these waves depends on differences in the ____.
A. frequencies of the two waves B. propagation speeds of the two media C. amplitudes of the two waves D. impedances of the two media |
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(247)An ulrasound wave approaches an interface between two media at a 90° angle. The propagation speeds and the densities of the two media are different. What is correct?
A. reflection will definitely occur B. reflection will definitely not occur C. refraction may occur D. none of the above |
(248)An ultrasound wave travels strikes an interface between two media at a 90° angle. The propagation speeds of the media are idnetical. However, the densities of the media are different. Which is true?
A. reflection will definitely occur B. reflection will definitely not occur C. refraction may occur D. none of the above |
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(249)What are the units of the intensity transmission coefficient?
A. watts/square cm B. watts C. dB D. none of the above |
(250)What are the units of the intensity reflection coefficient?
A. none B. W/cm² C. watts D. dB |
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(251)What are the units of the transmitted intensity of a sound wave?
A. W/cm² B. watts C. dB D. none; it is unitless |
(252)What results when the intensity transmission coefficient and the intensity reflection coefficient are added together?
A. incident intensity coefficient B. acoustic impedance C. total intensity D. 1.0 |
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(253)What remains when the reflected intensity is subtracted from the incident intensity?
A. 1.0 B. incident intensity C. transmitted intensity coefficient D. transmitted intensity |
(254)A wave strikes an interface between two media and intensities are measured at the interface. What results when the reflected intensity is divided by the incident intensity?
A. intensity reflection coefficient B. intensity transmission coefficient C. beam uniformity coefficient D. none of the above |
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(255)An ultrasound wave strikes a boundary between two media. All intensities are measured directly at the boundary. What results when the transmitted intensity is divided by the reflected intensity?
A. intensity reflection coefficient B. intensity transmission coefficient C. beam uniformity coefficient D. none of the above |
(256)an ultrasoud wave strikes an interface between two media. All intensities are measured directly at the interface. What results when the transmitted intensity is divided by the incident intensity?
A. intensity reflection coefficient B. intensity transmission coefficient C. beam uniformity coefficient D. none of the above |
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(257)What is the maximum permissible value for both the intensity reflection coefficient and the intensity transmission coefficient?
A. 100 B. 1% C. 1 D. infinity |
(258)What is the minimum permissible value for both the intensity reflection coefficient and the intensity transmission coefficient?
A. different from each other B. -1 C. 100% D. 0 |
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(259)A sound beam with an intensity of 45 w/cm² strikes a boundary and 70% of the wave's intensity is reflected. How much is transmitted?
A. 45 w/cm² B. 25 w/cm² C. 30% D. 100% |
(260)TRUE OR FALSE? When reflection occurs with oblique incidence, the angle of reflection equals the angle of incidence. This is known as Snell's Law.
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(261)What event does Snell's Law govern?
A. transmission B. refraction C. impedance |
(262)Which of the following best describes the process described by Snell's Law?
A. reflection with normal incidence B. reflection with oblique incidence C. transmission with normal incidence D. transmission with oblique incidence |
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(263)TRUE OR FALSE? Refraction occurs at the border between two media if and only if there is oblique incidence of the wave upon the boundary.
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(264)What conditions are necessary for refraction to occur at a boundary between two media?
A. unequal acoustic impedances and normal incidence at the boundary B. unequal densities of the media and normal incidence at the boundary C. dissimilar propagation speeds and oblique incidence at the boundary D. different elasticities of the media and oblique incidence |
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(265)TRUE OR FALSE? Refraction always occurs at the interface between two media when the propagation speeds of the media are unequal.
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(266)An acoustic wave is traveling from medium X into medium Z. Medium X has a propagation speed of 1,457 m/sec and an impedance of 1.44 MRayls. Medium Z has a propagation speed of 1,644 m/sec and an impedance of 1.26 MRayls. The angle of incidence is 32°. What is true of the angle of the transmitted wave?
A. it is greater than 32° B. it is equal to 32° C. it is less than 32° D. cannot be determined |
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(267)An acoustic wave in medium B is traveling toward medium A. The sound beam strikes the boundary at a 45° angle. The propagation speed is 1,547 m/sec for medium A and 1,745 m/sec for medium B. What is true of the angle of transmission?
A. >45° (> means "greater than") B. <45° (< means "less than") C. = 45° D. cannot be determined |
(268)TRUE OR FALSE? The period of a sound wave determines whether refraction will occur.
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(269)An acoustic wave is traveling from medium X into medium Z. Medium X has a propagation speed of 1,457 m/sec and an impedance of 1.44 MRayls. Medium Z has a propagation speed of 1,644 m/sec and an impedance of 1.26 MRayls. The angle of incidence is 32°. What is true of the angle of the reflection?
A. it is greater than 32° B. it is equal to 32° C. it is less than 32° D. cannot be determined |
(270)A wave of acoustic energy is leaving soft tissue and transmitting into fat with an 86° incident angle. What is true of the angle of transmission?
A. 86° B. less than 86° C. greater than 86° D. cannot be determined |
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An acoustic wave is in medium A and traveling toward medium B. The sound beam's angle of transmission into medium B with relation to the boundary is 79°. Sound's propagation speed is 1,547 m/sec in medium A and 1,745 m/sec in medium B. If reflection and transmission both occur at the boundary, what can be said of the reflection angle?
A. > 79° B. < 79° C. = 79° D. cannot be determined |
(272)Sound propagates from one medium with a density of 1.16 kg/m³ to a second medium with a density of 1.02 kg/m³. If the angle of transmission is 49°, what can be correctly stated about the angle of incidence?
A. it is less than 49° B. it is equal to 49° C. it is greater than 49° D. it cannot be determined |
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(273)How long does it take for sound to make a round trip to and from the skin's surface to a reflector 1 cm depth in soft tissue?
A. 13 µs B. 150 ms C. 15 µs D. 2 seconds |
(274)One reflector is 5 times deeper than another. The time of flight of sound to the deeper structure is ____ the time of flight of the shallower reflector.
A. one fifth as much as B. equal to C. less than D. five times more than |
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(275)In soft tissue, sound travels to a reflector and back to the transducer in 39 µseconds. How deep is the reflector?
A. 2 cm B. 6 cm C. 3 cm D. cannot be determined |
(276)In soft tissue, sound travels to a reflector and back to the transducer in 39 µs (39 microseconds or 39 millionths of a second). What is the total distance that the pulse traveled?
A. 2 cm B. 6 cm C. 3 cm D. cannot be determined |
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(277)Two ultrasound systems produce acoustic pulses. One pulse is 0.4 µsec in duration and the other is 0.2 µsec. Which pulse will most likely provide the best lateral resolution?
A. 0.4 µsec pulse B. 0.2 µsec pulse C. they are the same D. cannot be determined |
(278)Axial resolution describes the accuracy related to visualizing two structures that are ____ to a sound beam's main axis.
A. parallel B. perpendicular C. oblique D. normal |
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(279)You are purchasing a diagnostic ultrasound system. System X has axial resolution of 0.7 mm while System D's is 0.4 mm. Based on this information, which system will produce the better quality picture?
A. System X B. System D C. they have the same quality D. cannot be determined |
(280)TRUE OR FALSE? The lower the numerical value of the longitudinal resolution, the worse the picture.
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(281)An ultrasonic pulse has a pulse repetition period of 1.2 msec, a spatial pulse length of 2.0 mm and a wavelength of 0.4 mm. What is the axial resolution of the system?
A. 2.0 mm B. 1.0 mm C. 0.4 mm D. 1.8 mm |
(282)TRUE OR FALSE? The more cycles there are in a pulse, the greater the detail that will be visualized in the ultrasound scan.
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(283)Two imaging systems produce acoustic pulses; one pulse is 0.4 µsec long and the other is 2.0 µsec long. Which is most likely to provide the best temporal resolution?
A. 0.4 µsec system B. 0.2 µsec system C. they are the same D. cannot be determined |
(284)Two ultrasound systems produce pulses. One pulse is 0.4 µsec in duration and the other is 0.2 µsec long. Which pulse is most likely to provide the best radial resolution?
A. 0.4 µsec system B. 0.2 µsec system C. they are the same D. cannot be determined |
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(285)The axial resolution of an imaging system is reported to be 0.85 mm at the beam's focus. What is the closest estimate of the system's radial resolution at a location that is 5 cm deeper than the focus?
A. less than 0.85 mm B. equal to 0.85 mm C. greater than 0.85 mm |
(286)Two ultrasound systems produce acoustic pulses. A pulse from System 1 has a wavelength of 0.5 mm, 4 cycles per pulse, and a pulse repetition period 1.2 msec. The pulse from System 2 have a wavelength of 1.0 mm, 2 cycles per pulse, and a pulse repetition period of 1.8 msec. Which ultrasound system will have a lower numerical value of axial resolution?
A. System 1 B. System 2 C. both are the same D. cannot be determined |
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(287)Which transducer has the best axial resolution?
A. 2 cycles/pulse, 4 MHz B. 4 cycles/pulse, 4 MHz C. 4 cycles/pulse, 2 MHz D. 2 cycles/pulse, 2 MHz |
(288)Which transducer has the worst axial resolution?
A. 2 cycles/pulse, 4 MHz B. 4 cycles/pulse, 4 MHz C. 4 cycles/pulse, 2 MHz D. 2 cycles/pulse, 2 MHz |
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(289)A sonographer is performing a study on a patient and desires superior depth resolution. Which of the following changes would create such a system?
A. higher frequency B. shorter wavelength C. fewer cycles per pulse D. less ringing E. all of the above |
(290)TRUE OR FALSE? The pulse duration does not profoundly influence the lateral resolution.
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(291)TRUE OR FALSE? The higher the frequency of the cycles within a pulse, the lower the numerical value of the axial resolution.
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(292)TRUE OR FALSE? The shorter the pulse length, the better the picture.
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(293)TRUE OR FALSE? One way that a sonographer can alter the axial resolution achieved during an exam is to adjust the maximum imaging depth.
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(294(TRUE OR FALSE? The shorter the pulse duration, the better the picture.
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(295)TRUE OR FALSE? The length of a pulse does not directly influence the temporal resolution.
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(296)TRUE OR FALSE? With a specific ultrasound system and transducer, the system's axial resolution is invariant, and the sonographer can do nothing to improve it.
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(297)Which component of an ultrasound system is made of lead zirconate titanate (PZT)?
A. transducer's matching layer B. transducer's active element C. transducer's damping material D. scan converter's computer chips |
(298)TRUE OR FALSE? The characteristic impedance of acoustic gel is greater than the matching layer's impedance but less than the piezoelectric element
s impedance. |
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(299)The impedance of a transducer's matching layer is 2.6 MRayls and the impedance of the piezoelectric crystal is 3.4 MRayls. If this is assumed to be a good imaging system, what is the best estimate for the impedance of the skin?
A. 1.5 MRayls B. 3.8 MRayls C. 3.4 MRayls D. 2.8 MRayls |
(300)TRUE OR FALSE? The piezoelectric crystal of a transducer typically has an impedance higher than the impedance of skin.
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(301)Which of the following lists order the impedance from highest to lowest?
A. skin, gel, matching layer, PZT B. PZT, gel, matching layer, skin C. gel, PZT, matching layer, skin D. PZT, matching layer, gel, skin |
(302)What is the thickness of the matching layer of a 2 MHz pulsed wave transducer?
A. 1.54 mm B. 0.77 mm C. half the wavelength of the sound wave in the PZT D. one quarter the wavelength of sound in the matching layer |
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(303)TRUE OR FALSE? The acoustic impedance of the skin is greater than the acoustic impedance of both the matching layer and the piezoelectric element.
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(304)An ultrasonic pulse is traveling in soft tissue. Which of the following is most important in the determination of the frequency of the sound?
A. the propagation speed of the ultrasound transducer's matching layer B. the thickness of the transducer's backing material C. the impedance of the transducer's matching layer D. the propagation speed of the transducer's active element |
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(305)What is the best estimate of the propagation speed of the ferroelectric element of a transducer used in a typical diagnostic imaging laboratory?
A. 1.2 mm/µsec B. 4.0 m/sec C. 4.0 mm/µsec D. 1.0 km/sec |
(306)How thick is the active element of a 3 MHz pulsed wave transducer?
A. 1.54 mm B. 0.51 mm C. half the wavelength of the sound wave in the PZT D. one quarter the wavelength of sound in the matching layer |
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(307)Which of the following actions would cause a PZT crystal to lose its special properties?
A. breaking it in pieces B. exposing it to high temperatures C. exposing it to electrical current D. exposing it to low pressures |
(308)All of the following are true about transducers EXCEPT:
A. it is necessary to sterilize transducers before use B. most transducers require disinfection since they do to penetrate mucous membranes C. sterilization could depolarize PZT D. they are unlikely to transmit infection |
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(309)With regard to the backing material of a pulsed ultrasound transducer, is the following TRUE OR FALSE? The backing material helps to decrease the duty cycle at a particular PRF.
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(310)With regard to the backing material of a pulsed ultrasound transducer, is the following TRUE OR FALSE? The backing material decreases the quality factor.
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(311)With regard to the backing material of a pulsed ultrasound transducer, is the following TRUE OR FALSE? The spatial pulse length is decreased with the application of backing material.
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(312)With regard to the backing material of a pulsed ultrasound transducer, is the following TRUE OR FALSE? The pulse duration is increased as a result of the presence of backing material.
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(313)With regard to the backing material of a pulsed ultrasound transducer, is the following TRUE OR FALSE? The damping material helps to decrease the pulse repetition period achieved at a given imaging depth.
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(314)Which component of an ultrasound transducer is made from a slab of epoxy imbedded with tungsten particles?
A. the matching layer B. the piezoelectric crystal C. the damping material D. the computer chips |
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(315)TRUE OR FALSE? The purpose of the backing material of an ultrasound transducer is to shorten the pulses, thereby creating images with better image quality.
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(316)TRUE OR FALSE? In general, ultrasound imaging transducers have a lower quality factor and a wider bandwidth than therapeutic ultrasound transducers.
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(317)The main purpose of a transducer's case are (more than one answer may apply):
A. protect the patient from shock B. protect the patient from heat C. protect the internal components of the transducer D. protect the patient from radiation |
(318)Assume that the frequency of sound with the greatest power emitted by a transducer is 5 MHz. However, the pulse contains acoustic energy with frequencies as low as 3.5 MHz and as high as 6.5 MHz. What is the bandwidth of the transducer?
A. 6.5 MHz B. 5.0 MHz C. 3.5 MHz D. 3.0 MHz |
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(319)Assume that the frequency of sound with the greatest power emitted by a transducer is 5 MHz. However, the transducer produces acoustic energy with frequencies as low as 3.5 MHz and as high as 6.5 MHz. What is the quality factor of the transducer?
A. 5 B. 5/3.5 C. 5/6.5 D. 5/3 |
(320)Damping material is secured to piezoelectric material during the fabrication of an ultrasonic imaging transducer. Which of the following is not a consequence of this attachment?
A. bandwidth increases B. quality factor decreases C. sensitivity increases D. longer transducer case |
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(321)Which properties of the piezoelectric crystal of a continuous wave transducer result in the highest emitted acoustic wave frequency?
A. thin, high propagation speed B. thick, slow propagation speed C. thin, slow propagation speed D. none of the above |
(322)Which properties of the piezoelectric crystal of an imaging transducer result in the highest emitted acoustic wave frequency?
A. thin, high propagation speed B. thick, slow propagation speed C. thin, slow propagation speed D. none of the above |
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(323)You are asked to fabricate a pulsed ultrasound transducer with the highest possible frequency. Which piezoelectric crystal would you select?
A. 6 mm thick, 4 cm diameter, 4.0 mm/µs propagation speed B. 8 mm thick, 2 cm diameter, 2.0 mm/µs propagation speed C. 4 mm thick, 9 cm diameter, 5.0 mm/µs propagation speed D. 2 mm thick, 6 cm diameter, 6.0 mm/µs propagation speed |
((324)You are asked to fabricate a pulsed ultrasound transducer with the lowest possible frequency. Which piezoelectric crystal would you select?
A. 6 mm thick, 4 cm diameter, 4.0 mm/µs propagation speed B. 8 mm thick, 2 cm diameter, 2.0 mm/µs propagation speed C. 4 mm thick, 9 cm diameter, 5.0 mm/µs propagation speed D. 2 mm thick, 6 cm diameter, 6.0 mm/µs propagation speed |
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(325)What is the region from the transducer to the smallest cross-sectional area of a sound beam called?
A. focus B. half-value thickness C. near zone D. Fraunhofer zone |
(326)The area that starts at the beam's smallest diameter and extends deeper is:
A. the distant zone B. the Fresnel zone C. the Fraunhofer zone D. the depth of penetration |
