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Ultrasound Physics

170 Questions
Physics Quizzes & Trivia

Ultrasound Physics Questions

Questions and Answers
  • 1. 
    • A. 

      Density

    • B. 

      Pressure

    • C. 

      Distance

    • D. 

      Intensity

  • 2. 
    • A. 

      Two waves with identical frequencies must interfere constructively

    • B. 

      Constructive interference is associated with waves that are in phase

    • C. 

      Out of phase waves interfere destructively

    • D. 

      Waves of different frequencies may exhibit both contructive and destructive interference at different times

  • 3. 
    • A. 

      Deca

    • B. 

      Deci

    • C. 

      Micro

    • D. 

      Centi

  • 4. 
    • A. 

      30 KHZ

    • B. 

      8 MHz

    • C. 

      8,000 Hz

    • D. 

      3,000 kHz

    • E. 

      15 Hz

  • 5. 
    • A. 

      10,000 Hz

    • B. 

      1,000 kHz

    • C. 

      1kHz

    • D. 

      1MHz

  • 6. 
    • A. 

      Doubles

    • B. 

      Halved

    • C. 

      Remains the same

    • D. 

      4 times greater

  • 7. 
    • A. 

      Per minute

    • B. 

      Msec

    • C. 

      Mm/us

    • D. 

      MHx

  • 8. 
    The time from the beginning of a pulse until its end is__________?
    • A. 

      Period

    • B. 

      Pulse duration

    • C. 

      Pulse length

    • D. 

      PRF

  • 9. 
    • A. 

      0.3

    • B. 

      0.005

    • C. 

      0.5Hz

    • D. 

      0.005msec

  • 10. 
    • A. 

      Nothing

    • B. 

      Halved

    • C. 

      Dpib;ed

    • D. 

      Quadrupled

  • 11. 
    • A. 

      105

    • B. 

      50

    • C. 

      25

    • D. 

      55

  • 12. 
    • A. 

      Quadrupled

    • B. 

      Doubled

    • C. 

      Halved

    • D. 

      Unchanged

  • 13. 
    • A. 

      SATP

    • B. 

      SPTP

    • C. 

      SATA

    • D. 

      SPTP, SATP, SATA

    • E. 

      SPTP SATA, SATP

  • 14. 
    The duty factor for continuous wave ultrasound is
    • A. 

      10.0

    • B. 

      1%

    • C. 

      1.0

    • D. 

      0.0%

  • 15. 
    • A. 

      10.0

    • B. 

      1%

    • C. 

      1.0

    • D. 

      0.0%

  • 16. 
    Which pair of intensities has the same value for continuous wave US?
    • A. 

      Spatial peak & spatial average

    • B. 

      Temporal peak & spatial peak

    • C. 

      Pulse average & temporal average

    • D. 

      Spatial average & temporal average

  • 17. 
    • A. 

      1.25 MHz

    • B. 

      4.5 MHz

    • C. 

      4.8 MHz

    • D. 

      5 cm

  • 18. 
    • A. 

      10 cm

    • B. 

      10 mm

    • C. 

      10 m

    • D. 

      130 mm

    • E. 

      13 cm

  • 19. 
    • A. 

      0.5 dBcm

    • B. 

      1cm

    • C. 

      3dBcm

    • D. 

      1dB

  • 20. 
    • A. 

      5%

    • B. 

      Two times

    • C. 

      Twenty times

    • D. 

      One hundred times

    • E. 

      One million times

  • 21. 
    The more pixels per inch:
    • A. 

      The better the temporal resolution

    • B. 

      The better is the spatial resolution

    • C. 

      The more shades of gray

    • D. 

      The higher the reliability

  • 22. 
    • A. 

      Increased

    • B. 

      Decreased

    • C. 

      Unchanges

  • 23. 
    If the transducer diameter increases, the lateral resolution at its smallest dimension is
    • A. 

      Increased

    • B. 

      Decreased

    • C. 

      Unchanged

  • 24. 
    If we increase the frequency the near zone length is
    • A. 

      Increased

    • B. 

      Decreased

    • C. 

      Unchanged

  • 25. 
    If the frequency is decreased, the numerical value of the radial resolution is
    • A. 

      Increased

    • B. 

      Decreased

    • C. 

      Unchanged

  • 26. 
    If the spatial pulse length is 10 mm, what is the axial resolution?
    • A. 

      0.5 cm

    • B. 

      5 cm

    • C. 

      10 mm

    • D. 

      1 cm

  • 27. 
    Which of the following is the best lateral resolution?
    • A. 

      15 mm

    • B. 

      6 mm

    • C. 

      0.06 cm

    • D. 

      2 cm

  • 28. 
    • A. 

      A tissue temperature may rise 3 degrees Farenheit

    • B. 

      Tissue temperature will rise 3 degrees Celcius

    • C. 

      Tissue temperature may rise 3 degrees Celcius

    • D. 

      Microbubbles 3mm in diameter will burst

  • 29. 
    The interaction of microscopic bubbles and ultrasound form the basis for cavitation bioeffects.  Which of the following forms of cavitation are most likely to produce microstreaming in the intracellular fluid and shear stresses?
    • A. 

      Stable cavitation

    • B. 

      Normal cavitation

    • C. 

      Transient cavitation

    • D. 

      Inertial cavitation

    • E. 

      Active cavitation

  • 30. 
    • A. 

      B-Mode

    • B. 

      Gray scale imaging

    • C. 

      CW Doppler

    • D. 

      Pulsed Doppler

  • 31. 
    Which of the following best decribes the empirical approach to the study of bioeffects?
    • A. 

      Exposure-response

    • B. 

      Cause-effect

    • C. 

      Risk-benefit

    • D. 

      Causation-reaction

    • E. 

      Effect-microstreaming

  • 32. 
    Which of the following best describes the mechanistic approach to the study of bioeffects?
    • A. 

      Cause-effect

    • B. 

      Exposure-response

    • C. 

      Risk-benefit

    • D. 

      Causation-reaction

    • E. 

      Effect-microstreaming

  • 33. 
    • A. 

      1m/s

    • B. 

      1.54 m/s

    • C. 

      1.54 mm/us

    • D. 

      1 km/s

  • 34. 
    Enhancement, multipath and side lobes result in:
    • A. 

      Image distortion

    • B. 

      Clearer images

    • C. 

      Artifact

    • D. 

      Resolution problems

  • 35. 
    • A. 

      True

    • B. 

      False

  • 36. 
    If the lines per frame is increased while the imaging depth is unchanged then:
    • A. 

      Frame rate increases

    • B. 

      Number of shades of gray decreases

    • C. 

      The frame rate decreases

    • D. 

      This cannot happen

  • 37. 
    The more pixels per inch:
    • A. 

      The better the temporal resolution

    • B. 

      The better the spatial resolution

    • C. 

      The more shades of gray

    • D. 

      The higher the reliability

  • 38. 
    If we increase the transducer diameter, the beam diameter in the far zone is
    • A. 

      Increased

    • B. 

      Decreased

    • C. 

      Unchanges

  • 39. 
    If the transducer diameter increases, the lateral resolution at its smalles dimension is
    • A. 

      Increased

    • B. 

      Decreased

    • C. 

      Unchanged

  • 40. 
    If we increase the frequency the near zone length is
    • A. 

      Increased

    • B. 

      Decreased

    • C. 

      Unchanges

  • 41. 
    If the frequency is decreased, the numberical value of the radial resolution is
    • A. 

      Increased

    • B. 

      Decreased

    • C. 

      Unchanges

  • 42. 
    If the spatial pulse length is 10mm, what is the axial resolution?
    • A. 

      0.5 cm

    • B. 

      5 cm

    • C. 

      10 mm

    • D. 

      1 cm

  • 43. 
    Which of the following is the best lateral resolution?
    • A. 

      15 mm

    • B. 

      6 mm

    • C. 

      0.06 cm

    • D. 

      2 cm

  • 44. 
    What are the units of longitudinal resolution?
    • A. 

      Hertz

    • B. 

      Rayls

    • C. 

      M/s

    • D. 

      Feet

  • 45. 
    The range equation relates distant from the reflector to __________ and __________.
    • A. 

      Time-of-flight, distance

    • B. 

      Frequency, wavelength

    • C. 

      Time of flight, propagation speed

    • D. 

      Propagation speed, density

  • 46. 
    Doppler shifts always occur if the source and observer are in motion relative to each other and the angle between the motion and the sound beam is not 90 degrees.
    • A. 

      True

    • B. 

      False

  • 47. 
    What is the most typical Doppler shift measured clinically?
    • A. 

      3.5 MHz

    • B. 

      3,500,000 Hz

    • C. 

      2 kHz

    • D. 

      1,000 kHz

    • E. 

      20,000 Hz

  • 48. 
    • A. 

      The distance to the far field is reduced

    • B. 

      The beam width is the near field is reduced

    • C. 

      The beam width in the near field is increased

    • D. 

      The US wavelength is increased

    • E. 

      The sensitivity is reduced

  • 49. 
    • A. 

      Reflector spacing and reflection coefficient

    • B. 

      Attenuation and speed of the US in the medium

    • C. 

      Reflector spacing and US attenuation in the medium

    • D. 

      Reflector reflection coefficient and US attenuation in the medium

    • E. 

      Reflector spacing and propagation speed

  • 50. 
    • A. 

      True

    • B. 

      False

  • 51. 
    • A. 

      Partial volume artifact

    • B. 

      Slice thickness artifact

    • C. 

      Section thickness artifact

    • D. 

      Ghosting artifact

  • 52. 
    According to the AIUM statement on bioeffects, there have been no concirmed bioeffects below intensities of _________ watts per square centimeter SPTA.
    • A. 

      10

    • B. 

      0.01

    • C. 

      0.1

    • D. 

      1

    • E. 

      100

  • 53. 
    What component of the US unit contains the memory bank?
    • A. 

      Transducer

    • B. 

      Receiver

    • C. 

      Display

    • D. 

      Scan converter

  • 54. 
    Changing which of the following would not cause any change in a hard copy image output?
    • A. 

      TGC

    • B. 

      Overall gain

    • C. 

      Output power

    • D. 

      Display brightness & contrast

    • E. 

      Depth of view

  • 55. 
    What are typical clinical Doppler frequencies?
    • A. 

      1 - 10, 000 Hz

    • B. 

      1 - 10 MHz

    • C. 

      2 - 1,000 kHz

    • D. 

      40 - 45 kHz

  • 56. 
    • A. 

      5dB

    • B. 

      2dB

    • C. 

      10dB

    • D. 

      1.5dB

  • 57. 
    The distance to a target is doubled.  The time of flight for a pulse to travel to the target and back is
    • A. 

      4 times

    • B. 

      8 times

    • C. 

      The samce

    • D. 

      2 times

  • 58. 
    The gray scale can be changed by the sonographer
    • A. 

      True

    • B. 

      Fales

  • 59. 
    • A. 

      14

    • B. 

      1

    • C. 

      4

    • D. 

      3

    • E. 

      8

  • 60. 
    The manufacturer increases the number of lines per frame.  As a result, which of the following may have to decreased.  Frequency
    • A. 

      True

    • B. 

      False

  • 61. 
    The manufacturer increases the number of lines per frame.  As a result, which of the following may have to decreased. FRAME RATE (TRUE OR FALSE)
    • A. 

      True

    • B. 

      False

  • 62. 
    The manufacturer increases the number of lines per frame.  As a result, which of the following may have to decreased.  (Sector Angle)
    • A. 

      True

    • B. 

      False

  • 63. 
    The manufacturer increases the number of lines per frame.  As a result, which of the following may have to decreased. (IMAGING DEPTH)
    • A. 

      True

    • B. 

      False

  • 64. 
    The manufacturer increases the number of lines per frame.  As a result, which of the following may have to decreased. Power Output
    • A. 

      True

    • B. 

      False

  • 65. 
    All of the following will improve temporal resolution EXCEPT:
    • A. 

      Increase line density

    • B. 

      Single rather than multi focus

    • C. 

      Higher frame rate

    • D. 

      Shallower depth of view

    • E. 

      Slower speed in a medium

  • 66. 
    What artifact has a grainy appearance and is caused by the interference effects of scattered sound?
    • A. 

      Spackle

    • B. 

      Reverberation

    • C. 

      Slice tickness

    • D. 

      Speckle

    • E. 

      Section thickness

  • 67. 
    Multiple reflections that are equally spaced are called:
    • A. 

      Refractions

    • B. 

      Reverberations

    • C. 

      Shadows

    • D. 

      Comets

  • 68. 
    • A. 

      True

    • B. 

      False

  • 69. 
    Which of the following choces determines the signal amplitude in the transducers of an ultrasound system?
    • A. 

      Reflected intensity of the sound beam

    • B. 

      Post processing

    • C. 

      Edge enhancement filtering

    • D. 

      Persistence

    • E. 

      Demodulation

  • 70. 
    The angle between an US pulse and the boundary between two media is 90 degrees.  What is this called?
    • A. 

      Direct incidence

    • B. 

      Oblique incidence

    • C. 

      Indirect incidence

    • D. 

      Orthogonal incidence

  • 71. 
    Refraction only occurs if there is :
    • A. 

      Normal incidence and differenct impedances

    • B. 

      Indirect intensity and differenct propagation speeds

    • C. 

      Oblique incidence and different propagation speeds

    • D. 

      Oblique frequency and identical impedances

  • 72. 
    The most likely amount of reflection at a boundary between soft tissue is:
    • A. 

      1 %

    • B. 

      22 %

    • C. 

      33%

    • D. 

      99%

  • 73. 
    • A. 

      Angle of incidence > angle of reflection

    • B. 

      Angle of incidence = angle of reflection

    • C. 

      Angle of incidence < angle of reflection

  • 74. 
    • A. 

      40 mm

    • B. 

      45 mm

    • C. 

      60 mm

    • D. 

      65 mm

  • 75. 
    In an analog scan converter, what component stores the image data?
    • A. 

      Computer memory

    • B. 

      Video tape recorder

    • C. 

      Dielectric matrix

    • D. 

      None of the above

  • 76. 
    When the US machine displays only strong reflecting objects and nothing else, the sonographer should
    • A. 

      Adjust the gain

    • B. 

      Increase output power

    • C. 

      Increase lateral resolution

    • D. 

      Adjust the TGC

  • 77. 
    If a reflector is moved twice as far away from the tranducer, how will this affect the time of flight of a sound pulse?
    • A. 

      Quadruple it

    • B. 

      Double it

    • C. 

      No change

    • D. 

      Halve it

  • 78. 
    You are performing a quality assurance study on an ultrasound system using a tissue equivalent phantom.  You make an adjustment using a knob on the system console that changes the appearance of reflector brightness from fully bright to barely visible.  What are you evaluating?
    • A. 

      Resolution

    • B. 

      Dynamic range

    • C. 

      System sensitivity

    • D. 

      Vertical calibration

    • E. 

      Slice thickness

  • 79. 
    At what location in a sound beam is the SPTA intensity the highest?
    • A. 

      Focal point

    • B. 

      Focal zone

    • C. 

      Fresnel zone

    • D. 

      Fraunhofer zone

    • E. 

      Half value depth

  • 80. 
    What determines the frequency of a sound beam from a pulsed transducer?
    • A. 

      Voltage applied to the PZT

    • B. 

      PZT thickness

    • C. 

      Frequency of the system

    • D. 

      PRF of the pulser

  • 81. 
    • A. 

      36 X 10 ^6

    • B. 

      3,600

    • C. 

      10,000

    • D. 

      9.5 x 10^5

    • E. 

      9 x 10 ^4

  • 82. 
    What can pulsed Doppler measure that continuous wave cannot?
    • A. 

      Duration

    • B. 

      Speed

    • C. 

      Velocity

    • D. 

      Location

    • E. 

      Frequency

  • 83. 
    What is the fraction of time that sound is transmitting?
    • A. 

      Duty factor

    • B. 

      Pulse duration

    • C. 

      Period

    • D. 

      PRF spatial duration

  • 84. 
    If the SPTA of the following were equal, which would have the lowest SPPA?
    • A. 

      Doppler

    • B. 

      Annular array real time

    • C. 

      Static B-scan

    • D. 

      Linear arry

    • E. 

      Continuous wave

  • 85. 
    The dB is defined as the _______________ of two intensities
    • A. 

      Sum

    • B. 

      Difference

    • C. 

      Product

    • D. 

      Ratio

  • 86. 
    • A. 

      3 dB

    • B. 

      6 dB

    • C. 

      9 dB

    • D. 

      8 dB

  • 87. 
    An ultrasound system is set at 0 dB and is transmitting at full intensity.  What is the output power when the system is transmitting at 50% of full intensity?
    • A. 

      -3dB

    • B. 

      -50 dB

    • C. 

      10 dB

    • D. 

      3 dB

    • E. 

      -10 dB

  • 88. 
    • A. 

      - 3dB

    • B. 

      -50 dB

    • C. 

      40 dB

    • D. 

      3 dB

    • E. 

      -10 dB

  • 89. 
    • A. 

      Cm

    • B. 

      Hz

    • C. 

      Msec

    • D. 

      Watts

    • E. 

      None of the above

  • 90. 
    A Doppler exam is performed with a 5MHz probe and a PRF of 15kHz.  Which of these Doppler shifts will create aliasing?
    • A. 

      2 kHz

    • B. 

      2.5 kHz

    • C. 

      7.5 kHz

    • D. 

      14 kHz

  • 91. 
    According to the AIUM statement on bioeffects, there have been no confirmed bioeffects below intensities of __________ watts per square centimeter SPTA.
    • A. 

      10

    • B. 

      0.01

    • C. 

      0.1

    • D. 

      1

    • E. 

      100

  • 92. 
    Which of the following is not a measure of area?
    • A. 

      Square cm

    • B. 

      Meters squared

    • C. 

      Cubic meters

    • D. 

      Feet x feet

  • 93. 
    Which of the following is true of all waves?
    • A. 

      They travel through a medium

    • B. 

      All carry energy from one side to another

    • C. 

      Their amplitudes do not change

    • D. 

      They travel in a straight line

  • 94. 
    Is Intensity an acoustic variable?
    • A. 

      True

    • B. 

      False

  • 95. 
    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

  • 96. 
    Which of the following units are appropriate to describe the period of an acoustic wave?  More than one answer maybe correct.
    • A. 

      Minutes

    • B. 

      Microseconds

    • C. 

      Meters

    • D. 

      Mm/us

  • 97. 
    Two waves arrive at the same location and interfere.  The resultant sound wave is smaller that either of the two original waves.  What is this called?
    • A. 

      Constructive interference

    • B. 

      Angular interaction

    • C. 

      Destructive interference

    • D. 

      In-phase waves

  • 98. 
    • A. 

      Greater thatn 20,000 kHz

    • B. 

      Less thatn 1 kHz

    • C. 

      Greater than 10 MHz

    • D. 

      Greater thatn 0.02 MHz

  • 99. 
    Compare two sound waves. A and B.  The frequency of a wave A is one-third that of wave B.  How does the period of a wave A compare the period of wave B?
    • A. 

      A is one-third as long a B

    • B. 

      A is the same as wave B

    • C. 

      A is three times as long as B

    • D. 

      Cannot be determined

  • 100. 
    Which of the following wave is ultrasonic and least useful in diagnotic ultrasound?
    • A. 

      2 MHz

    • B. 

      2000 Hz

    • C. 

      24 kHz

    • D. 

      7.5 MHz

  • 101. 
    True of False:  With standard diagnostic imaging instrumentation, the sonographer has the ability to vary the amplitude of a sound wave produced by the transducer.
    • A. 

      Ture

    • B. 

      False

  • 102. 
    The power of an ultrasound wave can be reported with which of the following units? More than one answer maybe correct.
    • A. 

      Watts/square centimeter

    • B. 

      DB/Cm

    • C. 

      Watts

    • D. 

      Kg/cm^2

  • 103. 
    The maximum value of the density of an acoustic wave is 60 lb/in^2 while the minimum density is 20 lb/in^2.  What is the amplitude of the wave?
    • A. 

      20 lb/in^2

    • B. 

      40 lb/in^2

    • C. 

      60 lb/in^2

    • D. 

      None of the above

  • 104. 
    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

  • 105. 
    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 final power?
    • A. 

      3 watts

    • B. 

      9 watts

    • C. 

      1 watt

    • D. 

      None of the above

  • 106. 
    What are the units of intensity?
    • A. 

      Watts

    • B. 

      Watts/cm

    • C. 

      Watts/cm^2

    • D. 

      DB

  • 107. 
    If the power in an ultrasound beam is unchanged, while at the same time, the beam area doubles, then the beams's intensity
    • A. 

      Doubles

    • B. 

      Is halved

    • C. 

      Is quartered

    • D. 

      Remains the same

  • 108. 
    What happens to an acoustic beams's intensity when the power in the beam increases by 25% while the cross sectional area of the beam remain the same?
    • A. 

      It increased by 25%

    • B. 

      Increases by 75%

    • C. 

      It increases by 50%

    • D. 

      Decreases by 25%

  • 109. 
    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 time larger

  • 110. 
    What determines the intensity of an ultrasound beam after it has traveled through the body?
    • A. 

      The sound wave's source

    • B. 

      The medium throught which the sound travels

    • C. 

      Both A and B

    • D. 

      Neither choice A nor B

  • 111. 
    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

  • 112. 
    The wavelength of a cycle in an ultrasound wave can be reported with which units?
    • A. 

      Units of time (seco, min, etc)

    • B. 

      Units of distance (feet, cm)

    • C. 

      Units of area (m^2, etc

    • D. 

      Mm only

  • 113. 
    Which of the following terms best describes the relationship between frequency and wavelength for sound traveling in soft tissue?
    • A. 

      Receiprocal

    • B. 

      Direct

    • C. 

      Related

    • D. 

      Inverse

  • 114. 
    • A. 

      True

    • B. 

      False

  • 115. 
    The frequency closest to the lower limits of US is:
    • A. 

      19,000kHz

    • B. 

      10,000 MHz

    • C. 

      20,000 msec

    • D. 

      15,000 Hz

  • 116. 
    Which of the following sound waves is ultrasonic and least useful in diagnostic imaging?
    • A. 

      30 KHz

    • B. 

      8 MHz

    • C. 

      8,000 Hz

    • D. 

      3,000 kHz

    • E. 

      15 Hz

  • 117. 
    _____________ is the distance covered by one cycle
    • A. 

      Pulse length

    • B. 

      Wavelength

    • C. 

      Cycle distance

    • D. 

      Cycle duration

  • 118. 
    If the frequency of US is increased from 0.77 MHz to 1.54 MHz, what happens to the wavelength?
    • A. 

      Doubles

    • B. 

      Halved

    • C. 

      Remains the same

    • D. 

      4 times greater

  • 119. 
    If the frequency is decreased, the numberical value of the radial resolution is
    • A. 

      Increased

    • B. 

      Decreased

    • C. 

      Unchanged

  • 120. 
    If we increase the frequency, the near zone length is
    • A. 

      Increased

    • B. 

      Decreased

    • C. 

      Unchanged

  • 121. 
    The digital scan converter has a number of pixels assigned to each bit.
    • A. 

      True

    • B. 

      False

  • 122. 
    The more bits per pixel
    • A. 

      The better the resolution

    • B. 

      The higher the pizel density

    • C. 

      The more shades of gray

    • D. 

      Higer reliability

  • 123. 
    What is the actual time that an US machine is creating a pulse?
    • A. 

      Duty factor

    • B. 

      Period

    • C. 

      Pulse period

    • D. 

      Pulse duration

  • 124. 
    The angle of incidence of an US beam is perpendicular to an interface.  The two media have the same propagation speeds.  What process cannot occur?
    • A. 

      Refraction

    • B. 

      Reflection

    • C. 

      Transmission

    • D. 

      Attenuation

  • 125. 
    What is the most typical Doppler shift measured clinically?
    • A. 

      3.5 MHz

    • B. 

      3,500,000 Hz

    • C. 

      2kHz

    • D. 

      1,000 kHz

    • E. 

      20,000 Hz

  • 126. 
    If the frequency is decreased, the numerical value of the radial resolution is
    • A. 

      Increased

    • B. 

      Decreased

    • C. 

      Unchanges

  • 127. 
    The digital scan converter has a number of pixels assigned to each bit.
    • A. 

      True

    • B. 

      False

  • 128. 
    The more bits per pixel
    • A. 

      The better the resolution

    • B. 

      The higher the pixel density

    • C. 

      The more shades of gray

    • D. 

      Higher reliability

  • 129. 
    Increasing the frequency increases the penetration depth.
    • A. 

      True

    • B. 

      False

  • 130. 
    All of the following will improve temporal resolution EXCEPT
    • A. 

      Increased line density

    • B. 

      Single rather than multi focus

    • C. 

      Higher frame rate

    • D. 

      Shallower depth of view

    • E. 

      Slower speed of sound in a medium

  • 131. 
    What componet of a transducer changes electrial to mechanical and mechanical back to electrical engery?
    • A. 

      PZT

    • B. 

      Scan converter

    • C. 

      Demodulator

    • D. 

      Receiver

  • 132. 
    What determines the frequency of a sound beam from a pulsed transducer?
    • A. 

      Voltage applied to the PZT

    • B. 

      PZT thickness

    • C. 

      Frequency of the system

    • D. 

      PRF of the pulser

  • 133. 
    What measures the output of the a transducer?
    • A. 

      Receiver

    • B. 

      Display

    • C. 

      Hydrometer

    • D. 

      Hydrophone

  • 134. 
    Which type of artifact appears most commonly with highly reflective objects?
    • A. 

      Reverberations

    • B. 

      Mirroring

    • C. 

      Shadowing

    • D. 

      Enhancement

    • E. 

      Defocusing

  • 135. 
    Which of the following will result in the highest mechanical index?
    • A. 

      High frequency and low power

    • B. 

      High intensity and high frequency

    • C. 

      Low frequency and high signal amplitude

    • D. 

      Low intensity and low frequency

  • 136. 
    All of the following statements reqarding in-vitro bioeffects are true EXCEPT
    • A. 

      In vitro bioeffects conclusions are clinically relevant

    • B. 

      In vitro bioeffects are always real

    • C. 

      In vitro bioeffects are very important

    • D. 

      In vitro bioeffects may not be applicable to clinical settings

  • 137. 
    Which of the following is not used to measure the output of ultrasound systems?
    • A. 

      Calibrated absorpterometer

    • B. 

      Hydrophone

    • C. 

      Thermocouple

    • D. 

      Calorimeter

    • E. 

      Liquid crystals

  • 138. 
    Under which circumstance is cavitation most likely to occur?
    • A. 

      High frequency and low power

    • B. 

      High intensity and high frequency

    • C. 

      Low intensity and low frequency

    • D. 

      Low frequency and high signal amplitude

  • 139. 
    Post processing occurs when the image
    • A. 

      Is played off the VCT

    • B. 

      Entered the A/D converter but before display

    • C. 

      After it leaves the A/D converter

    • D. 

      After it leaves the can converter

  • 140. 
    What happens to venous blood flow to the heart during expiration?
    • A. 

      Increases

    • B. 

      Decreases

    • C. 

      Unchanged

  • 141. 
    Which of the following has a propagation speed closest to "soft tissue"?
    • A. 

      Muscle

    • B. 

      Fat

    • C. 

      Bone

    • D. 

      Air

  • 142. 
    What is displayed on the y axis of an m-mode image?
    • A. 

      Time

    • B. 

      Time of flight

    • C. 

      Echo intensity

    • D. 

      Red blood cell velocity

  • 143. 
    An amplifier of an ultrasound system increases the voltage of a signal from 0.0001 to 0.1 volt.  What is the amplification?
    • A. 

      60 dB

    • B. 

      30 dB

    • C. 

      1,000 dB

    • D. 

      90 dB

  • 144. 
    Which of the following will result in the greatest number of shades of gray in a digital image display?
    • A. 

      Large pixels with many bits/pixel

    • B. 

      Small pixels with few bits/pixel

    • C. 

      Many TV lines per frame

    • D. 

      High contrast

    • E. 

      Narrow dynamic range

  • 145. 
    With good images on the CRT but not on the strip chart recorder, one should
    • A. 

      Increase the gain

    • B. 

      Check the scan head

    • C. 

      Check the scan converter

    • D. 

      Adjust the recorder

  • 146. 
    Shadowing may result from high amounts of reflection of US energy.
    • A. 

      True

    • B. 

      False

  • 147. 
    Where are harmonics created?
    • A. 

      In the receiver

    • B. 

      In the transducer

    • C. 

      In the tissue

    • D. 

      In the beam former

  • 148. 
    • A. 

      Lower the PRF

    • B. 

      Raise the PRF

    • C. 

      Increase the gain

    • D. 

      Use a lower frequency transducer

  • 149. 
    For Doppler, which incident angle reults in no shift?
    • A. 

      180

    • B. 

      90

    • C. 

      0

    • D. 

      45

  • 150. 
    Which transducer would be best to image superficial structures?
    • A. 

      Small diameter, high frequency

    • B. 

      Small diameter, low frequency

    • C. 

      Large diameter, high frequency

    • D. 

      Large diameter, low frequency

  • 151. 
    What information does Doppler shift provide?
    • A. 

      Flow

    • B. 

      Cardiac out put

    • C. 

      Velocity

    • D. 

      Speed

  • 152. 
    Circumferences are usually measured in:
    • A. 

      Cm

    • B. 

      Cm squared

    • C. 

      Cubic cm

    • D. 

      Cubits

  • 153. 
    Decimal uses a base of 10, binary uses a base of
    • A. 

      1

    • B. 

      2

    • C. 

      5

    • D. 

      10

  • 154. 
    If the frame rate increases and the lines per frame is unchanged, what else must happen?
    • A. 

      US speed increases

    • B. 

      Frequency increases

    • C. 

      Depth increases

    • D. 

      Depth decreases

  • 155. 
    How many decibels is related to 90% decrease in imaging power?
    • A. 

      -1dB

    • B. 

      -10dB

    • C. 

      -90dB

    • D. 

      -100dB

  • 156. 
    If the output of an US machine is calibrated in dB and the output is increased by 20 dB, the beam intensity is increased
    • A. 

      100 times

    • B. 

      1,000,000 times

    • C. 

      20 times

    • D. 

      10 times

  • 157. 
    Which has the greatest amount of attenuation?
    • A. 

      Bone

    • B. 

      Fat

    • C. 

      Water

    • D. 

      Muscle

  • 158. 
    Refraction only occurs if there is :
    • A. 

      Normal incidence and different impedances

    • B. 

      Indirect intensity and differenct propagation speeds

    • C. 

      Oblique incidence and different propagation speeds

    • D. 

      Oblique frequency and identical impedances

  • 159. 
    With normal incidence, what factors affect refraction of US?
    • A. 

      Propagation speeds

    • B. 

      Frequencies

    • C. 

      Attenuation coefficients

    • D. 

      None of the above

  • 160. 
    Which of the following is associated with power mode Doppler?
    • A. 

      Poor temporal resolution and flash artifact

    • B. 

      Lower sensitivity and good temporal resolution

    • C. 

      High sensitivity and high frame rates

    • D. 

      Flash artifact and reduced sensitivity

    • E. 

      Good temporal resolution and flash artifact

  • 161. 
    The sonographer cannot change, directly or indirectly, the duty factor of an US machines.
    • A. 

      True

    • B. 

      False

  • 162. 
    There have not been biological effects from US found in the laboratory.
    • A. 

      True

    • B. 

      False

  • 163. 
    As the impedances of two media become vastly different, the
    • A. 

      Reflection increases

    • B. 

      Transmission increases

    • C. 

      Refraction increases

    • D. 

      Absorption increases

  • 164. 
    What is the minimum value of the duty factor?
    • A. 

      10.0

    • B. 

      1%

    • C. 

      1.0

    • D. 

      0.0%

  • 165. 
    Assuming a fixed frequency, what happens if the diameter of an ultrasound circular transducer is increased?
    • A. 

      The distance to the far field is reduced

    • B. 

      The beamwidth in the near field is reduced

    • C. 

      The beamwidth in the far field is reduced

    • D. 

      The ultrasonic wavelength is increased

    • E. 

      The sensitivity is reduced

  • 166. 
    From a safety standpoint, which one of the following methods is best?
    • A. 

      Low transmitter output and high receiver gain

    • B. 

      High transmitter output and low receiver gain

    • C. 

      High near gain and low far gain

    • D. 

      Low near gain and high far gain

    • E. 

      High reject and high transmitter output

  • 167. 
    Which one of the following instruments is a component that stores digital echo signal information?
    • A. 

      Demodulator

    • B. 

      Receiver

    • C. 

      Video monitor

    • D. 

      Logarithmic amplifier

    • E. 

      Scan converter

  • 168. 
    The dynamic range of the receiver of an ultrasound instrument refers to the
    • A. 

      Ability of the receiver to track a rapidly moving structure

    • B. 

      Range of echo signal frequencies that can be processed without distortion

    • C. 

      Speed with which the receiver recovers following the excitation pulse to the transducer

    • D. 

      Depth range in tissue over which moving echoes can be received

    • E. 

      Range of echo signal amplitudes that can be processed without distortion

  • 169. 
    A sound wave leaves its source and travels through air.  The speed of sound in air is 330 m/sec.  One second later, an echo returns to the source.  At what distance from the source is the reflector that produced the echo?
    • A. 

      1540 meters

    • B. 

      770 meters

    • C. 

      660 meters

    • D. 

      330 meters

    • E. 

      165 meters

  • 170. 
    Whichone of the following statements is true about a single pulse of ultrasound from a transducer?
    • A. 

      It contains a range of frequencies

    • B. 

      It contains sound at the nominal frequency of the transducer only

    • C. 

      It contains sound at the center frequency of the transducer only

    • D. 

      The shorter the pulse the narrower the bandwidth

    • E. 

      Sound engery is continuously transmitted

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