Chapter 5 - Doppler Principles

63 Questions

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Chapter 5 - Doppler Principles

Questions and Answers
  • 1. 
    Which of the following are parts of the circulatory system?
    • A. 

      Heart

    • B. 

      Cerebral Ventricle

    • C. 

      Artery

    • D. 

      Arteriole

    • E. 

      Capillary

    • F. 

      Bile Duct

    • G. 

      Venule

    • H. 

      Vein

  • 2. 
    The _____ are the tiniest vessles in the circulatory system?
    • A. 

      Vein

    • B. 

      Capillaries

    • C. 

      Arteries

  • 3. 
    In which of the following can Doppler ultrasound detect flow?
    • A. 

      Heart

    • B. 

      Arteries

    • C. 

      Arterioles

    • D. 

      Capillaries

    • E. 

      Venules

    • F. 

      Veins

  • 4. 
    To flow is to move in a ______.
    • A. 

      Direction

    • B. 

      Pattern

    • C. 

      Stream

  • 5. 
    The characteristic of a fluid that offers resistance to flow is called?
    • A. 

      Resistance

    • B. 

      Viscosity

    • C. 

      Inertia

    • D. 

      Impedance

    • E. 

      Density

  • 6. 
    Poise is a unit of
    • A. 

      Visocity

    • B. 

      Friction

    • C. 

      Inertia

  • 7. 
    Pressure is ______ per unit area.
    • A. 

      Force

    • B. 

      Fricition

    • C. 

      Liquid

  • 8. 
    If the pressure is greater at one end of the liquid-filled tube or vessle than it is at the other, the liquid will flow from the _____ pressure and to the _____ pressure end.
    • A. 

      Higher, lower

    • B. 

      Lower, higher

    • C. 

      Depends on the liquid

    • D. 

      All of the above

    • E. 

      None of the above

  • 9. 
    Flow increases if _____ increase(s).
    • A. 

      Pressure difference

    • B. 

      Pressure gradient

    • C. 

      Resistance

    • D. 

      A and B

    • E. 

      All of the above

  • 10. 
    As flow resistance increases, volumetic flow rate will
    • A. 

      Increase

    • B. 

      Decrease

    • C. 

      Stay the same

  • 11. 
    If pressure difference is doubled, volumetric flow rate is
    • A. 

      Unchanged

    • B. 

      Quartered

    • C. 

      Halved

    • D. 

      Doubled

    • E. 

      Quadrupled

  • 12. 
    If flow resistance is doubled, volumetric flow rate is
    • A. 

      Unchanged

    • B. 

      Quartered

    • C. 

      Halved

    • D. 

      Doubled

    • E. 

      Quadrupled

  • 13. 
    Flow resistance in a vessel depends on _______.
    • A. 

      Vessel length

    • B. 

      Vessel radius

    • C. 

      Blood viscosity

    • D. 

      All of the above

    • E. 

      None of the above

  • 14. 
    Flow resistance decreases with an increase in ______.
    • A. 

      Svessel length

    • B. 

      Vessel radius

    • C. 

      Blood viscosity

    • D. 

      All of the above

    • E. 

      None of the above

  • 15. 
    Flow resistance depends most strongly on ____.
    • A. 

      Vessel length

    • B. 

      Vessel radius

    • C. 

      Blood viscosity

    • D. 

      All of the above

    • E. 

      None of the above

  • 16. 
    Volumetric flow rate decreases with an increase in ____.
    • A. 

      Pressure difference

    • B. 

      Vessel radius

    • C. 

      Vessel length

    • D. 

      Blood viscosity

    • E. 

      C and d

  • 17. 
    When the speed of a fluid is constant across a vessel, the flow is called _____ flow.
    • A. 

      Volume

    • B. 

      Parabolic

    • C. 

      Laminar

    • D. 

      Viscous

    • E. 

      Plug

  • 18. 
    __________ flow occurs wen straight parallel streamlines describing the flow are altered.
    • A. 

      Disturbed

    • B. 

      Turbulent

    • C. 

      Plug

    • D. 

      Viscous

  • 19. 
    _____________ flow involves random and chaotic flow patterns, with particles flowing in all directions.
    • A. 

      Disturbed

    • B. 

      Turbulent

    • C. 

      Plug

    • D. 

      Viscous

  • 20. 
    Turbulent flow is more likely proximal or distal to a stenosis
    • A. 

      Proximal

    • B. 

      Distal

  • 21. 
    A narrowing of the lumen of a tube is called a _________.
    • A. 

      Stenosis

    • B. 

      Pulsatile

    • C. 

      Disturbed

  • 22. 
    Proximal to , at, and distal to a stenosis ________, must be constant.
    • A. 

      Laminar flow

    • B. 

      Disturbed flow

    • C. 

      Turbulent flow

    • D. 

      Volumetic flow rate

    • E. 

      None of the above

  • 23. 
    Poiseuille's equation predicts a(n) ________ in flow speed with a decrease in vessel radius.  
    • A. 

      Decrease

    • B. 

      Increase

  • 24. 
    In a stenosis, the pressure if _______ the proximal and distal values.
    • A. 

      Less than

    • B. 

      Equal to

    • C. 

      Greater than

    • D. 

      Depends on the fuild

    • E. 

      None of the above

  • 25. 
    The _______ effect is used to detect and measure ________ in vessels.
    • A. 

      Doppler, flow

    • B. 

      Poiseuille's, velocity

    • C. 

      Color, flow

  • 26. 
    Motion of an echo-generating structure causes an echo to have a different _______ from that of the emitted pulse.
    • A. 

      Frequency

    • B. 

      Period

    • C. 

      Pulse duration

  • 27. 
    If the incident frequency is 1 MHz, the propagation speed is 1600 m/s, and the reflector speed is 16 m/s toward the source, the Doppler shift is _________________ MHz.
  • 28. 
    If the incident frequency is 1 MHz, the propagation speed is 1600 m/s, and the reflector speed is 16 m/s toward the source, the reflected frequency is _____________ MHz.
  • 29. 
    If 2-MHz ultrasound is reflected from a soft tissue boundary moving at 10 m/s toward the source, the Doppler shift is ________ MHz.
  • 30. 
    The doppler shift is the difference between  ______ and ______ frequencies
    • A. 

      Emitted & received

    • B. 

      Beginning & end

    • C. 

      Continuous & listening

  • 31. 
    When incident sound direction and reflector motion are not parallel, calculation of the refelcted frequency involves the _______ of the angle btwn these directions
    • A. 

      Cosine

    • B. 

      Inside

    • C. 

      Outside

  • 32. 
    For an operating frequency of 2 MHz, a flow speed of 10 cm/s, and a Doppler angle of 0 degrees, calcuate the Doppler Shift.
  • 33. 
    For an operating frequency of  6 MHz, a flow speed of 50 cm/s, and a Doppler angle of 60 degrees, calculate the Doppler Shift.
  • 34. 
    Which Doppler angle yields the greatest Doppler Shift?
    • A. 

      -90

    • B. 

      -45

    • C. 

      0

    • D. 

      45

    • E. 

      90

  • 35. 
    If operating frequency is doubled, the Doppler shift is
    • A. 

      Half

    • B. 

      Doubled

    • C. 

      Quadrupled

    • D. 

      Same

  • 36. 
    If flow speed is doubled, the Doppler shift is
    • A. 

      Doubled

    • B. 

      Quadrupled

    • C. 

      Stays the same

    • D. 

      Half

  • 37. 
    If Doppler angle is doubled, the doppler shift is
    • A. 

      Decreased

    • B. 

      Increased

    • C. 

      Stays the same

  • 38. 
    Which of the following on a color doppler display is (are) presented in real time?
    • A. 

      Gray-scale anatomy

    • B. 

      Flow direction

    • C. 

      Doppler spectrum

    • D. 

      A & B

    • E. 

      All of the above

  • 39. 
    In color doppler instruments, color is used only to represent flow direction.
    • A. 

      True

    • B. 

      False

  • 40. 
    The angle dependencies of Doppler shift displays and Doppler power displays are different.
    • A. 

      True

    • B. 

      False

  • 41. 
    In practice, approximately ________ pulses are requried to obtain one line of color doppler information.
    • A. 

      1

    • B. 

      10

    • C. 

      100

    • D. 

      1000

    • E. 

      1,000,000

  • 42. 
    About  ________ frames per seocnd are produced by a color Doppler instrument.
    • A. 

      10

    • B. 

      20

    • C. 

      40

    • D. 

      80

    • E. 

      More than one of the above

  • 43. 
    Doppler shift displays are not dependent on Doppler angle.
    • A. 

      True

    • B. 

      False

  • 44. 
    If a color doppler instrument shows two colors in the same vessel, it always means flow is occuring in opposit directions in the vessels.
    • A. 

      True

    • B. 

      False

  • 45. 
    A region of bright color on doppler shift display always indicates the highest flow speeds.
    • A. 

      True

    • B. 

      False

  • 46. 
    Increasing the ensemble length _______ the frame rate.
    • A. 

      Increases

    • B. 

      Decreases

    • C. 

      Stays the same

  • 47. 
    Which of the following reduce the frame rate of a color doppler image?
    • A. 

      Wider color window

    • B. 

      Longer color window

    • C. 

      Increased ensemble length

    • D. 

      Higher transducer frequency

    • E. 

      Higher priority setting

  • 48. 
    Lack of color in a vessel containing blood flow may be attributable to ______.
    • A. 

      Low color gain

    • B. 

      A high wall filter setting

    • C. 

      A low priority setting

    • D. 

      Baseline shift

    • E. 

      Aliasing

  • 49. 
    Increasing ensemble length ________ color sensitivity and accuracy and ______ frame rate
    • A. 

      Improves, increases

    • B. 

      Degrades, increases

    • C. 

      Degrades, decreases

    • D. 

      Improves, decreases

  • 50. 
    Which control can be used to help with clutter?
    • A. 

      Wall filter

    • B. 

      Gain

    • C. 

      Baseline shift

    • D. 

      Pulse repetition frequency

    • E. 

      Smoothing

  • 51. 
    Doubling the width of a color window produces a(n) ________ frame rate.
    • A. 

      Doubled

    • B. 

      Quadrupled

    • C. 

      Unchanged

    • D. 

      Halved

    • E. 

      Quartered

  • 52. 
    Steering the color window to the right or left produces a(n) _____ frame rate
    • A. 

      Doubled

    • B. 

      Quadrupled

    • C. 

      Unchanged

    • D. 

      Halved

  • 53. 
    Steering the color window to the right or left changes ________. (multiple answers)
    • A. 

      Frame rate

    • B. 

      Pulse repetition frequency

    • C. 

      Doppler angle

    • D. 

      Doppler shift

  • 54. 
    Color Doppler frame rates are _________ gray-scale rates.
    • A. 

      Equal to

    • B. 

      Less than

    • C. 

      More than

    • D. 

      Depends on color map

    • E. 

      Depends on priority

  • 55. 
    Compared with Doppler-shift imaging, Doppler-power imaging is ___________ .
    • A. 

      More sensitive

    • B. 

      Angle independent

    • C. 

      Aliasing independent

    • D. 

      Speed independent

    • E. 

      All of the above

  • 56. 
    Doppler-power imaging indicates (with color) the  _______ of flow.
    • A. 

      Presence

    • B. 

      Direction

    • C. 

      Speed

    • D. 

      Character

  • 57. 
    Doppler-shift imaging indicates (with color) the  __________ of flow.
    • A. 

      Presence

    • B. 

      Direction

    • C. 

      Speed

    • D. 

      Character

    • E. 

      More than one of the above

  • 58. 
    Doppler signal power is proportional to ____________.
    • A. 

      Volume flow rate

    • B. 

      Flow speed

    • C. 

      Doppler angle

    • D. 

      Cell concentration

    • E. 

      More than one of the above.

  • 59. 
    Stenosis affects _________
    • A. 

      Peak systolic flow speed

    • B. 

      End diastolic flow speed

    • C. 

      Spectral broadening

    • D. 

      Window

    • E. 

      All of the above

  • 60. 
    As stenosis progresses, which fo the following increase(s)?
    • A. 

      Lumen diameter

    • B. 

      Systolic doppler shift

    • C. 

      Diastolic doppler shift

    • D. 

      Spectral broadening

    • E. 

      More than one of the above

  • 61. 
    Higher flow speed always produces a higher doppler shift on a spectral display
    • A. 

      True

    • B. 

      False

  • 62. 
    Which of the following is increased if Doppler Angle is increase?
    • A. 

      Aliasing

    • B. 

      Doppler shift

    • C. 

      Effect of angle error

    • D. 

      B & C

    • E. 

      None of the above

  • 63. 
    If a 5 kHz doppler shift corresponds to 100 cm/s, then a 2.5 kHz shift corresponds to _______ cm/s