Echo Board Review

The flashcards below were created by user kevrhayes on FreezingBlue Flashcards.

  1. What is sound?
    the compression and rarefaction of a medium
  2. What is the equation for velocity?
    v = wavelength x frequency
  3. What is the average velocity in soft tissue?
    1540 m/sec
  4. Does velocity vary with issue?
    yes - 4080 m/sec in bone; 330 m/sec in air
  5. What is the frequency of ultrasound?
    > 20,000 hertz
  6. What is wavelength?
    the distance between peaks
  7. What is the standard wavelength?
    1540 m/sec (velocity) / 3 MHz (frequency) = 0.5 mm
  8. What is amplitude?
    Difference between maximum and minimum
  9. What is power?
    total output in watts
  10. What is intensity?
    the amount of energy delivered per unit area (watts / cm2) in u/s
  11. On what scale is decibel?
  12. What is the mechanical index?
    the potential of a frequency to cause cavitation

    • MI > 1 = destroys microbubbles
    • MI < 0.1 = weak harmonics
  13. What is thermal index?
    ability of u/s to heat tissue - no important in adult echo, important in fetal echo
Card Set:
Echo Board Review
2013-02-26 02:49:33
echo mayo dvds

These cards are from watching the Mayo Board Review DVDs from 2011
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