quiz #1 – ultrasound

  1. what is ultrasound
    • high-frequency sound waves >20,000 Hz
    • therapeutic ultrasound 1–3 million hertz
  2. how deep does ultrasound penetrate
    approximately 5 cm
  3. how does ultrasound produce heat
    through friction
  4. true or false – absorption decreases with density of tissue
    false – absorption increases with density of tissue
  5. what is cavitation
    the creation of bubbles

    • bad for blood
    • cerebral spinal fluid– don't cross the spinal cord, okay to go parallel with the spinal cord
    • eyes- don't go over forehead
  6. what does this picture represent
    Image Upload 2
  7. What is refraction?
    a change in direction of the soundwave due to different density of tissues
  8. what does this picture represent
    Image Upload 4
  9. What occurs with reflection?
    the wave doesn't penetrate but instead bounces off
  10. true or false – the periosteum of the bone is at risk for burns when performing ultrasound
    true- this would occur due to reflection
  11. what is piezoelectric effect
    AC passes into crystal which vibrates at same frequency as AC
  12. what is transduction
    change of one energy to another

    Vibration to electricity and electricity to vibration
  13. how is the intensity of ultrasound measured and what is a typical value used in the clinic?
    • Watts/cm squared or Watts
    • .5-2.5 watts/cm squared
  14. true or false – crystals in ultrasound heads are now synthetically made
  15. the typical outlet has a frequency of _____ Hz
    And power of _______V
    • 60 Hertz
    • 120 V
  16. Image Upload 6
  17. Image Upload 8
  18. Image Upload 10
  19. which frequency will penetrate the body at a greater depth?
    A) 1 MHz
    B) 3 MHz
    A) 1 MHz
  20. how long does the typical ultrasound treatment last
    5– 10 min.
  21. what are some examples of coupling medias
    • ultrasound gel
    • water
  22. true or false – ultrasound treatments always cover a large area
    false – areas treated are always small
  23. what are some of the therapeutic effects of ultrasound
    • relieve pain– thermal effect
    • increase elasticity of tissue – thermal effect
    • reduce inflammation – thermal effect
    • break adhesions/mineral deposits – mechanical effect
    • push drugs through the skin – mechanical effect (steroid products)
  24. what are the indications for ultrasound
    • subacute/chronic inflammation
    • joint contractures
    • muscle spasms
    • scar tissue (be careful with thermal modality on a scar)
    • trigger points
    • calcium deposits
    • plantar warts
    • chronic ulcers
  25. what are some of the contraindications for ultrasound
    • acute inflammation
    • hemorrhage
    • vital organs – heart, neck, etc.
    • epiphyseal growth plates
    • fractures (will break up the new callus)
    • malignant tumor (break off cancerous cells)
    • pregnant abdomen
    • infection
    • thrombophlebitis (causes swelling and pain)
    • impaired sensation
    • impaired circulation
    • metal implants
Card Set
quiz #1 – ultrasound