1. Home
  2. Flashcards
  3. Preview

Echo Board Review

  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?
    Log
  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
Author
kevrhayes
ID
203422
Card Set
Echo Board Review
Description
These cards are from watching the Mayo Board Review DVDs from 2011
Updated

  1. Home
  2. Flashcards
  3. Preview