Diagnostic Ultrasound 1

  1. What are the two different types of ultrasound?
    • diagnostic
    • therapeutic
  2. What is diagnostic ultrasound?
    short bursts of ultrasound
  3. Does diagnostic ultrasound cause damage to tissue?
  4. What is therapeutic ultrasound?
    constant wave of sound?
  5. What is the purpose of therapeutic ultrasound?
    used to breakdown tissue
  6. What is the nature of sound?
    wave of mechanical pressure
  7. What is ultrasound transmitted through?
    a medium - air, metal, body
  8. What is a frequency?
    cycles per second
  9. What is frequency measured in?
    • 1 hertz (Hz) = 1 cycle per second
    • 1 megahertz (MHz) = 1,000,000 cycles/second
  10. What ranges of frequency are used in veterinary medicine?  What are the common frequencies used?
    • range from 2.5 - 12 MHz
    • commonly used:  3.5 MHz, 5 MHz, 7.5 MHz
  11. Can people hear the frequency of an ultrasound?
  12. What frequency can people hear?  Dogs?
    • people:  20 - 20,000 Hz
    • dogs:  70 - 100,000 Hz
  13. What is velocity?
    speed of transmission of the sound wave
  14. What is the formula for velocity?
    velocity = wavelength x frequency
  15. the velocity of ultrasound in the patient's body is a _____.
  16. As frequency increases, wavelength _____.
  17. As frequency decreases, wavelength _____.
  18. How do we get shorter sound waves?
    use higher frequency transducer (7.5 MHz) or setting
  19. Short sound waves give _____ image resolution
    • increased
    • clear, detailed picture
  20. Shorter sound waves give _____ patient penetration.
  21. What are some examples of what we can use shorter sound waves on?
    • abdomen in cats and small dogs
    • eyes
    • tendons of horses
  22. Longer sound waves give _____ patient penetration
  23. Longer sound waves _____ image resolution.
    • decreased
    • more grainy, less detail
  24. What would we use longer sound waves to exam?
    • deeper structures
    • abdominal ultrasound in medium and large size dogs
  25. How is the image of an ultrasound formed?
    by the pattern, intensity, and depth of the reflected sound waves (echos)
  26. Echos or sound waves are _____ in proportion to tissue density.
  27. Does ultrasound penetrate air?
  28. What color is air on an ultrasound?
  29. What does ultrasound not penetrate air?
    because there is such a great change in density between air and tissue
  30. Ultrasound cannot see past air _____, _____, and _____.
    • trapped in hair coat
    • pockets in the GI system (stomach, intestines)
    • in normal lungs
  31. Can ultrasound tell anything about a structure behind or surrounded by air?
  32. Is bone dense?
  33. What color is bone on an ultrasound?
  34. Can ultrasound tell us anything about a structure behind or surrounded by air?
  35. Does ultrasound penetrate fluid well?
  36. What color is fluid on an ultrasound?
  37. An ultrasound image will appear _____ if fluid has particles in it?
  38. What are the intermediate tissues in the body?
    • muscles
    • liver
    • kidneys
    • most body tissues
  39. What color are intermediate tissues on an ultrasound?
  40. What is echogenicity?
    • how much does the matter reflect echos
    • quality of the echo produced by ultrasound waves in different matter
  41. What are the different echogenicity?
    • anechoic
    • hypoechoic
    • isoechoic
    • hyperechoic
  42. How many echos does anechoic produce?
  43. What color is anechoic?
  44. Where do we see anechoic?
    pure water
  45. How many echos does hypoechoic produce?
    few echos
  46. Where do we does hypoechoic?
    water or fluid with particles, urine, blood
  47. What color is hypoechoic?
    dark gray to black
  48. How many echos does isoechoic produce?
    about the same number of echos
  49. What color is isoechoic?
    shades of gray on screen
  50. What is isoechoic?
    soft tissue densities
  51. How many echos are hyperechoic?
    excessive echos
  52. What does hyperechoic look like?
  53. What things are hyperechoic?
    • bone
    • air
    • stones
  54. Can we use barium for an ultrasound?  Why or why not?
    no - it reflects
  55. What kind of contrast material can we use for an ultrasound?
    can inject bolus of saline with little air bubbles into the jugular vein to watch it go through the heart
  56. Is ultrasound safe?
    yes - no ionizing radiation and can be used repeatedly
  57. Is ultrasound invasive?
  58. Does ultrasound require sedation?
    • no
    • not painful, no strange positions, patient tolerates it well, decreases cost
  59. Other than looking at structures, what can ultrasound be good for?
    • permits guided aspiration or biopsy of lesions in internal organs
    • place needle correctly
    • avoid vital structures (example - large blood vessels)
  60. What are some disadvantages to using ultrasound?
    • takes time to learn to use and evaluate
    • ultrasound shows cross sections - need to learn to interpret
    • equipment is expensive
  61. Are we able to distinguish between soft tissue densities and liquid densities using ultrasound?  Xrays?
    • Ultrasound:  yes
    • X-rays:  no
  62. Is ultrasound hazardous?  X-ray?
    • Ultrasound:  no
    • X-ray: yes
  63. Can you examine the internal structures of organ using ultrasound?  X-ray?
    • Ultrasound:  yes
    • X-ray:  no
  64. Are we able to examine structure in real time using ultrasound?  X-ray?
    • Ultrasound:  yes
    • X-ray:  no
  65. Does ultrasound give us a large, over-all picture?  X-ray?
    • Ultrasound:  no
    • X-ray:  yes
  66. Why do we need to prep the patient for an ultrasound?
    to prevent the presence of air between the patient and transducer
  67. How do we prep the patient for ultrasound?
    • clip closely to remove hair
    • apply contact gel
  68. Why do we need to clip the hair before ultrasound?
    hair holds air next to the skin and clipping the hair removes scales, dirt and debris
  69. Why do we use contact gel for ultrasound?
    • for better skin contact
    • air displacement
  70. What is the transducer?
    hand-held probe
  71. What does the transducer contain?
    piezoelectric crystals
  72. What are the piezoelectric crystals for?
    when electricity is passed through the crystal, the crystal vibrates and produces ultrasound waves
  73. What are the different types of transducers?
    • linear array
    • sector scanners
  74. What is a linear array transducer?
    several crystals placed side by side
  75. What kind of image does a linear array transducer produce?
    rectangular image
  76. What does the linear array transducer look like?
    "in line" or "T" shaped
  77. Linear array has a large _____.
    footprint or contact area
  78. What is a linear array transducer good for?
    transrectal reproductive exams in cattle and horses
  79. What is a sector scanner?
    the crystal sweeps back and forth across the area
  80. What does a sector scanner image look like?
    wedge shaped image
  81. What does a sector scanner look like?
    probe shape - rod or cone shaped
  82. What size footprint does a sector scanner have?
  83. What is the sector scanner commonly used for?
    • can put between ribs
    • commonly used in small animals
  84. Why do we use different transducers or change the settings?
    to get different frequencies of ultrasound waves
  85. Different frequencies have different size _____.
  86. What is the 3.5 MHz frequency used for?
    • deep penetration
    • less resolution
    • big dog, horse abdomen
  87. What is the the 5 MHz frequency used for?
    • medium penetration
    • medium resolution
    • medium to big dog abdomen
  88. What is the 7.5 MHz frequency used for?
    • shallow penetration
    • very good resolution
    • cat and small dog abdomens, eyes, tendons of horse
  89. What does the transducer do?
    • transmits and receives sound waves
    • integrates picture and displays it on the screen
  90. Transducer transmits about _____ of the time.  Transducer receives about _____ of the time.
    • 0.01%
    • 99.99%
  91. Returning sound is converterd to _____.
    electrical energy
  92. What are the different types of display modes?
    • B-mode
    • M-mode
  93. What is the B-mode?
    brightness mode
  94. What does the B-mode produce?
    • most recognizable images
    • "real time" or "static" images
  95. What are "real time" images?
    sees structures as they are at that moment
  96. What does "real time" allow us to do?
    view and evaluate the motion of a structure
  97. What is a "static" image?
    can freeze a frame of a real time image
  98. What is M-mode?
    motion mode
  99. What scanner is used for M-mode?
    sector scanner
  100. What do the crystals in the sector scanner do?
    crystals stays still, sees things moving past it
  101. What kind of images does the M-mode produce?
    rectangular image with squiggly lines
  102. Is the M-mode used often in veterinary medicine?
  103. What is the M-mode mainly used for?
  104. What does the M-mode measure in echocardiography?
    thickness of heart walls, valves, and great vessels
  105. What are the different ultrasound artifacts?
    • acoustic shadowing
    • acoustic enhancement
  106. What is acoustic shadowing?
    area of darkness occurring deep to a dense structure
  107. What is acoustic enhancement?
    area of brightness occurring deep to a fluid-filled structure
  108. How do we clean the ultrasound equipment?
    wipe off probes and units as needed with water or mild disinfectants
  109. Can we clean the ultrasound equipment with alcohol?
    no because it will damage the surface
  110. What are some clinical uses for ultrasound?
    • tendon evaluation
    • thoracic
    • reproductive
    • cardiac
    • abdominal
  111. What kind of animals do we usually use ultrasound to evaluate tendons?
  112. What happens to tendons when they are injured?
    the parallel fibers pull apart and fill with blood
  113. What do we need in order to look into the thorax?
    "acoustic window"
  114. Where do we look between or beneath to see structures in the thorax?
    between or beneath the ribs
  115. What can you detect in the thorax using ultrasound?
    • consolidtaed lung
    • fluid in or around lungs
    • collapsed lung
    • masses in lung if not surrounded by air
  116. When can you use ultrasound to diagnose pregnancy in mares? Dogs?
    • mares:  day 14
    • dogs:  day 18 - 20
  117. What do we evaluate about the fetus during an ultrasound?
    • heart beat
    • bone formation
    • gas (cause - decomposition of dead tissue)
    • count fetuses
  118. What do we evaluate about the heart during an ultrasound?
    • see valves move
    • measure thickness of walls
    • measure contractility
  119. What do we evaluate about abdominal organs during an ultrasound?
    • masses in liver
    • calculi in bladder
    • ovarian cysts
  120. What kind of mass evaluation do we do with ultrasound?
    • cyst
    • abscess
    • solid
  121. What do we evaluate about the eye during an ultrasound?
    • detached retina
    • mass behind eye
    • prolapsed lens
  122. Other than evaluating structures, what can we use ultrasound for?
    • guidance for fine needle aspiration (example - cysto)
    • guidance for biopsy
    • guidance for culture
Card Set
Diagnostic Ultrasound 1
Clinical Practice ll