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45 Cards in this Set
- Front
- Back
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Reducing the likelihood of bioeffects from acoustic energy is the mission of the:
a. Nyquist limit b. Reynolds principle c. Huygens principle d. ALARA principle e. Poiseuille principle |
d. ALARA principle
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The number of cycles in a pulse directly relates to the:
a. duty factor b. spacial pulse length c. operating frequency d. pulse repetition frequency e. propagation speed of the medium |
b. spacial pulse length
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The Doppler shift frequency is proportional to the:
a. cosine values b. Doppler angle c. operating frequency d. velocity of the vector e. propagation speed of the medium |
d. velocity of the vector
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In the Fraunhofer zone the beam:
a. width diverges b. is conical in shape c. intensity is greatest d. intensity is inconsistent e. widens towards the focal zone |
a. width diverges
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Artifacts consisting of parallel equally spaced lines are characteristic of:
a. multipath b. grating lobes c. reverberation d. range ambiguity e. acoustic shadowing |
c. reverberation
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An increase in reflection amplitudes from reflectors behind a weakly attenuating structure is termed:
a. comet-tail artifact b. acoustic shadowing c. slice thickness artifact d. acoustic enhancement e. propagation speed error |
d. acoustic enhancement
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The ratio of the largest power to the smallest power the ultrasound system can handle describes:
a. amplitude b. bandwidth c. compensation d. dynamic range e. contrast resolution |
d. dynamic range
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Axial resolution directly relates to the:
a. penetration depth b. spacial pulse length c. temporal resolution d. transducer diameter e. operating frequency |
e. operating frequency
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When voltage is applied to the piezoelectric crystal, the crystal will:
a. vibrate b. increase in size c. decrease in size d. remain unchanged e. increase or decrease depending on the polarity |
e. increase or decrease depending on the polarity
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The resistance of the arterioles accounts for about what percentage of the total systemic resistance:
a. 10% b. 25% c. 33% d. 50% e. 75% |
d. 50%
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Rayleigh scattering is mostly likely to occur when encountering the:
a. liver b. pleura c. diaphragm d. red blood cells e. urinary bladder |
d. red blood cells
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Which color always represents the baseline in color Doppler imaging:
a. red b. blue c. white d. black e. yellow |
d. black
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Which of the following correctly defines acoustic frequency:
a. length of one cycle b. numbers of pulses in a cycle c. number of cycles in a second d. strength of the compression wave e. amount of time to complete one cycle |
c. number of cycles in a second
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What component is not present in A-mode but is necessary for B-mode imaging:
a. clock b. display c. amplifier d. transducer e. scan converter |
e. scan converter
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Grating lobes are caused by:
a. high frame rates b. dynamic focusing c. reverberation effect d. interference phenomenon e. spacing of the array elements |
e. spacing of the array elements
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Clutter can be reduced using which of the following controls:
a. wall filter b. smoothing c. baseline shift d. dynamic range e. pulse repetition frequency |
a. wall filter
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Regions of high density in an acoustic wave are termed:
a. cycles b. reflections c. rarefactions d. transmissions e. compressions |
e. compressions
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Decibel is the unit of measurement for:
a. intensity b. pressure c. amplitude d. duty factor e. compression |
e. compression
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Transmission of the sound wave from one medium to the next is determined by the media:
a. density b. stiffness c. amplitude d. impedance e. propagation speed |
d. impedance
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Focusing of sound beam:
a. decreases beam intensity b. improves lateral resolution c. increases specular reflections d. widens the sound beam in the near zone e. creates a spacious sound beam over a specified area |
b. improves lateral resolution
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As the transducer diameter increases, the:
a. near zone length decreases b. thickness of the element decreases c. intensity in the focal zone increases d. divergence in the far field decreases e. propagation speed of the element decreases |
d. divergence in the far field decreases
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Holding a single image of sonographic information for display is termed as:
a. byte b. pixel c. scan line d. cine loop e. freeze frame |
e. freeze frame
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Convert the binary number 0010011 to a decimal equivalent:
a. 10 b. 19 c. 21 d. 35 e. 41 |
b. 19
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The thickness of the matching layer is equal to:
a. the wavelength b. twice the wavelength c. one half of the frequency d. one half of the wavelength e. one-quarter of the wavelength |
e. one-quarter of the wavelength
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Which of the following is most likely to improve axial resolution:
a. increasing the frame rate b. decreasing the beam width c. increasing the penetration depth d. decreasing the angle of incidence e. increasing the transducer frequency |
e. increasing the transducer frequency
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What pulse wave transducer displays a trapezoidal image:
a. vector b. linear c. sector d. convex e. endocavity |
a. vector
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Heat sterilization of ultrasound transducer is not recommended because:
a. it will void the warranty b. the transducer's stability decreases c. heat will damage the electric cables d. the piezoelectric properties will be lost e. the transducer assembly cannot withstand the temperature |
d. the piezoelectric properties will be lost
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The formation of a beam from an aperture is explained by:
a. Snell's lam b. ALARA principle c. piezoelectric effect d. Huygens principle e. Poiseuille equation |
d. Huygens principle
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The Fresnel zone is another name for the:
a. far zone b. dead zone c. near zone d. focal zone e. focal length |
c. near zone
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Which of the following must remain constant proximal to, at, and distal to a stenosis:
a. velocity b. pressure c. resistance d. fluid viscosity e. volumetric flow rate |
e. volumetric flow rate
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The greater the impedance difference between two structures, the greater the:
a. refraction b. reflection c. attenuation d. transmission e. reverberation |
b. reflection
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Which Doppler angle yields the greatest Doppler shift:
a. 0⁰ b. 10⁰ c. 35⁰ d. 45⁰ e. 60⁰ |
a. 0⁰
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Increasing the transducer frequency will:
a. decrease image quality b. decrease contrast resolution c. increase the penetration depth d. increase the amount of attenuation e. decrease sensitivity to Doppler shifts |
d. increase the amount of attenuation
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Image quality is improved by:
a. decreasing the output b. decreasing the frame rate c. increasing the beam width d. shortening the pulse length e. decreasing the operating frequency |
d. shortening the pulse length
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What is the purpose of the dampening material in the transducer assembly:
a. increase sensitivity b. reduce pulse duration c. eliminate grating lobes d. improve sound transmission into the body e. diminish reflections at the transducer surface |
b. reduce pulse duration
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Which of the following instruments generates the pulse of sound:
a. pulser b. amplifier c. transducer d. beam former e. master synchronizer |
a. pulser
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Firing delays found in the array systems are determined by the:
a. receiver b. transducer c. beam former d. master synchronizer e. transmitter/receiver switch |
c. beam former
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The speed at which a wave travels through a medium is determined by the:
a. frequency of the sound source b. distance from the sound source c. stiffness and density of the medium d. resistance and impedance of the medium e. amplitude and intensity of the sound beam |
c. stiffness and density of the medium
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Which of the following is a method for overcoming aliasing:
a. shift the baseline b. increase imaging depth c. decrease the Doppler depth d. increase the operating frequency e. decrease the pulse repetition frequency |
a. shift the baseline
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Brightening of echoes in the focal zone is a result of:
a. acoustic speckle b. mirror image artifact c. slice thickness artifact d. horizontal enhancement e. propagation speed error |
d. horizontal enhancement
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A disadvantage of duplex imaging is a(n):
a. decrease in imaging frame rate b. inability to display peak velocities c. inability to demonstrate flow direction d. decrease in maximum penetration depth e. inability to accurately place the sample gate |
a. decrease in imaging frame rate
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Which of the following transducers will produce a longer focal length if the crystal diameter remains constant:
a. 5-10 MHz focused transducer b. 10 MHz focused transducer c. 5 MHz unfocused transducer d. 10 MHz unfocused transducer e. 2-5 MHz phased array transducer |
d. 10 MHz unfocused transducer
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The duty factor in pulse ultrasound is proportional to the:
a. pulse duration b. penetration depth c. operating frequency d. pulse repetition period e. propagation speed of the medium |
a. pulse duration
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Depth gain compensation is necessary to:
a. counteract attenuation b. increase axial resolution c. decrease contrast resolution d. store echo amplitudes and locations e. adjust the pulse repetition frequency |
a. counteract attenuation
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The Reynolds number predicts the onset of:
a. aliasing b. turbulent flow c. parabolic flow d. a Doppler shift e. biological effects |
b. turbulent flow
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