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50 Cards in this Set
- Front
- Back
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In soft tissue, if the frequency of a wave increases, the propagation speed will: A) double B) increase C) decrease D) remain the same |
D) remain the same |
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The range of frequencies found within a pulse describes which of the following terms? A) duty factor B) bandwidth C) harmonics D) pulse repetition frequency |
B) bandwidth |
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In gray-scale imaging, how many cycles per pulse are generally used? A) 2 to 3 B) 4 to 5 C) 5r to 10 D) 10 to 30 |
A) 2 to 3 |
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Which of the following frequencies is within the audible range? A) 15 Hz B) 15 kHz C) 25 kHz D) 25,000 Hz |
B) 15 kHz |
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Propagation speed through a medium is determined by the: A) pulse repetition period B) intensity and amplitude of the wave C) density and stiffness of the medium D) impedance difference between the medium |
C) density and stiffness of the medium |
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Which of the following is an acoustic variable? A) intensity B) wavelength C) particle motion D) propagation speed |
C) particle motion |
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In soft tissue, a 7.5-MHz transducer with a two-cycle pulse will generate a spatial pulse length of: A) 0.2 mm B) 0.4 mm C) 0.8 mm D) 1.5 mm |
B) 0.4 mm |
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If the stiffness of a medium increases, the propagation speed will: A) double B) increase C) decrease D) remain the same |
B) increase |
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The length of a pulse from beginning to end is termed the: A) wavelength B) pulse duration C) spatial pulse length D) pulse repetition period |
C) spatial pulse length |
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In which of the following media does sound propagate the fastest? A) air B) bone C) muscle D) soft tissue |
B) bone |
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What is the frequency of a sound wave in soft tissue demonstrating a wavelength of 0.1 mm? A) 2.0 MHz B) 5.0 MHz C) 7.5 MHz D) 15.0 MHz |
D) 15.0 MHz |
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If the amplitude of a wave doubles, the intensity will: A) double B) quadruple C) decrease by half D) decrease by one quarter |
B) quadruple |
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The time for one pulse to occur defines: A) period B) pulse duration C) spatial pulse length D) pulse repetition period |
B) pulse duration |
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Which of the following is associated with a broader bandwidth? A) a lower Q-factor B) an increase in amplitude C) a longer spatial pulse length D) a decrease in the number of frequencies within the pulse |
A) a lower Q-factor |
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Regions of low density in a compression wave are termed: A) cycles B) bandwidth C) rarefactions D) compressions |
C) rarefactions |
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Which of the following formulas calculate the duty factor? A) power of the source divided by the area B) pulse duration divided by the pulse repetition period C) pulse repetition frequency divided by the pulse duration D) frequency of the source multiplied by the propagation speed |
B) pulse duration divided by the pulse repetition period |
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Resistance to the propagation of sound through a medium defines: A) reflection B) attenuation C) acoustic impedance D) Rayleigh's scatter |
C) acoustic impedance |
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How long will it take for sound to travel 5 cm round-trip in soft tissue? A) 26 µs B) 30 µs C) 65 µs D) 130 µs |
C) 65 µs |
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Overall compensation gain is set at 36 dB. If the gain is reduced by one half, what will the new gain be? A) 18 dB B) 25 dB C) 30 dB D) 33 dB |
D) 33 dB |
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Attenuation occurring as sound propagates through each centimeter of soft tissue is equal to: A) 1/2 operating frequency B) attenuation coefficient * path length C) medium density * propagation speed D) 1/2 (propagation speed * round-trip time) |
A) 1/2 operating frequency |
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Spatial is a term used to describe: A) time B) speed C) space D) distance |
C) space |
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Which of the following units measures the attenuation of sound in soft tissue? A) µs B) dB C) rayls D) dB/cm |
B) dB |
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If the frequency is increased, pulse duration will: A) double B) increase C) decrease D) remain unchanged |
C) decrease |
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Which of the following metric prefixes denotes 1 billion? A) deca B) mega C) tetra D) giga |
D) giga |
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Which of the following units of measurement represents the number of pulses occurring in 1 second? A) µs B) kHz C) mW D) W/cm2 |
B) kHz |
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Which of the following formulas determines the impedance of a medium? A) attenuation multiplied by the propagation speed of the medium B) propagation speed of the medium multiplied by the round-trip time C) density of the medium multiplied by the attenuation coefficient D) density of the medium multiplied by the propagation speed of the medium |
D) density of the medium multiplied by the propagation speed of the medium |
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Weakening of a sound wave as it travels through a medium defines: A) scattering B) harmonics C) attenuation D) acoustic impedance |
C) attenuation |
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Which of the following occurs when a sound wave strikes a large, smooth surface at a 90 degree angle? A) refraction B) specular reflection C) Rayleigh's scatter D) nonsecular reflection |
B) specular reflection |
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With perpendicular incidence, what percentage of the incident beam continues to the next medium? A) 50% B) 85% C) 99% D) 100% |
C) 99% |
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The unit of measurement used to describe the amplitude of a pressure wave is: A) rayl B) watt C) joule D) variable |
D) variable |
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Which of the following properties is proportional to the pulse repetition frequency? A) period B) duty factor C) penetration depth D) spatial pulse length |
B) duty factor |
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Which of the following will most likely decrease the propagation speed of a wave? A) increasing the penetration depth B) increasing the stiffness of the medium C) decreasing the transducer frequency D) increasing the density of the medium |
D) increasing the density of the medium |
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For short pulses, the quality (Q) factor is equal to: A) the distance of one pulse B) one half of the frequency C) the number of cycles in a pulse D) the intensity of the sound beam |
C) the number of cycles in a pulse |
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The positive half of a pressure wave corresponds to: A) amplitude B) intensity C) rarefaction D) compression |
D) compression |
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In perpendicular incidence, what percentage of the sound wave will reflect at a boundary if the impedance of medium 1 is 40 rayls and the impedance of medium 2 is 50 rayls? A) 1% B) 10% C) 75% D) 90% |
A) 1% |
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Bending of a transmitting sound beam after it passes through one medium into another describes: A) scattering B) refraction C) reflection D) reverberation |
B) refraction |
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Attenuation is most commonly a result of: A) reflection B) scattering C) absorption D) transmission |
C) absorption |
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Half value layer is equal to an intensity reduction of: A) 3 dB B) 6 dB C) 10 dB D) 50 dB |
A) 3 dB |
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Propagation speed is directly related to: A) density B) stiffness C) frequency D) wavelength |
B) stiffness |
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Which of the following is proportional to the impedance of a medium? A) wavelength B) propagation speed C) stiffness of the medium D) attenuation coefficient |
B) propagation speed |
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Which of the following units compares the ratio of amplitudes along two points of a sound wave? A) W B) dB C) rayl D) dB/cm |
B) dB |
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Attenuation of the sound beam is proportional to the: A) frequency of the sound wave B) direction of the incident beam C) reflected intensity of the sound wave D) transmitted intensity of the sound wave |
A) frequency of the sound wave |
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Which of the following is responsible for determining the amount of reflection and transmission of the sound wave? A) density B) stiffness C) impedance D) propagation speed |
C) impedance |
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Dissipation of heat in a medium primarily in the form of head describes: A) reflection B) refraction C) absorption D) half value layer |
C) absorption |
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At what depth will a 3.0-MHz frequency demonstrate an attenuation of 9 dB? A) 2 cm B) 3 cm C) 6 cm D) 9 cm |
C) 6 cm |
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Snell's law determines the amount of: A) reflection at an interface B) refraction at an interface C) transmission through a medium D) scattering distal to a dense medium |
B) refraction at an interface |
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Direction of the incident beam with respect to the media boundary is termed the: A) specular angle B) reflection angle C) propagating angle D) transmission angle |
B) reflection angle |
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Demonstration of boundaries between organs is a result of: A) refraction B) transmission C) specular reflection D) Rayleigh scattering |
C) specular reflection |
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What is the penetration depth of a 3.5-MHz frequency when imaging the abdominal aorta? A) 0.86 cm B) 1.71 cm C) 0.86 mm D) 1.75 mm |
B) 1.71 cm |
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With perpendicular incidence, the larger the impedance difference between the media, the greater the: A) scattering B) reflection C) absorption D) transmission |
B) reflection |
