Davies Physics Questions With Accurate Detailed Answers

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DAVIES PHYSICS QUESTIONS WITH ACCURATE DETAILED || || || || || ||




ANSWERS


During a sonographic examination of a large vessel, a 45 degree beam-to-vessel angle would
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be called:
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A: Normal incidence
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***B: Oblique incidence
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C: Perpendicular incidence
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D: Snell's incidence
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E: None of the above
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Which sound beam frequency would exhibit the greatest intensity loss with increasing
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depth?

****A: 10MHz || ||




B: 8 MHz
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C: 5 MHz
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D: 3 MHz
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E: 2 MHz
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According to Snell's law, the angle of transmission is related to the incident beam angle and:
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A: The amount of acoustic impedance mismatch at an interface.
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B: The change in frequency that occurs at an interface.
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C: One-half of the angle of incidence.
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***D: The relative speeds of sound in the two media.
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E: The percentage of diffraction distal to the interface.
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Ultrasound propagation velocity depends on: || || || ||




A: Amplitude and frequency
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B: Impedance and attenuation
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,2


***C: Density and compressibility
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D: Dynamic range and compression
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E: Impedance and density
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while performing a doppler ultrasound examination, you adjust the pulse repetition
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frequency to 12 kHz. this can also be expressed as:
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12,000 kHz ||




which of the following factors does NOT affect impedance?
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-- stiffness
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-- density
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-- propagation speed
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***-- frequency
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-- all of the above
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During a diagnostic ultrasound examination, you encounter all of the interactions of
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ultrasound and tissue listed below. Which one will NOT cause a redirection of part of the
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ultrasound energy? ||




A: Reflection
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B: Scattering
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C: Divergence
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****D: Absorption ||




E: Refraction
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during the performance of a sonographic examination, you would be most likely to
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encounter refraction in this view: || || || ||




curved interface ||




(best answer; second best was specular reflector)
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Interference patterns of reflected waves causes: || || || || ||




***A: Acoustic speckle
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,2


B: Acoustic enhancement
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C: Rarefaction
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D: Volume averaging
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E: All of the above
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which of the following increases as frequency increases?
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-- absorption
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-- scattering
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-- attenuation
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--A and C onlu
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***-- all of the above
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What sound parameter is determined only by the medium?
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A: Frequency
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B: Period
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C: Intensity
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***D: Propagation speed|| || ||




E: None of the above
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which of the following is an example of Rayleigh scatterer?
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red blood cell
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which of the following human tissues has the highest rate of attenuation of an ultrasound
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wave?

-- liver
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-- fat
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--fluid

***--lung

--blood vessels ||

, 2


while performing a sonographic exam, you encounter the following interfaces. which will
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produce the weakest reflected signal? || || || ||




-- organ parenchyma/ fluid
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--organ parenchyma/ air || ||




***--organ parenchyma/ organ parenchyma || || || ||




-- organ parenchyma/ bone
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-- organ parenchyma/ ligament
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You are imaging a structure containing two media having the same acoustic impedance.
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What will occur at the boundary of the two structures?
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***A: All of the sound will be transmitted.
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B: All of the sound will be reflected.
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C: Some of the sound will be refracted.
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D: Some of the sound will be reflected and some of the sound will be transmitted.
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E: Most of the sound will be absorbed at the media boundary.
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what system control should you adjust to compensate for sound attenuation with increasing
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depth?
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TGC

In order to display a structure on your sonographic image the sound beam must be reflected
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at the interface. What is required for sound reflection at the interface of two structures?
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A: Oblique incidence at the interface boundary.
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B: Temperature differences between the two media.
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***C: A difference in the acoustic impedance of the media.
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D: Different media diameters.
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E: Different attenuation coefficients.
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What interaction of ultrasound and tissue is primarily responsible for imaging the internal
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structure of organs? || ||




A: Specular reflection
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