doppler optimization

• true flow reversal vs aliasing

  true flow reversal = demonstrate red, black, and blue color flow adjacent to each other

  *aliasing will not*
• type of artifact?

  aliasing

  
• type of artifact?

  aliasing

  
• type of artifact?

  none --> true flow reversal

  
• most effective way of getting rid of aliasing?

  adjust the color Doppler scale
• how to fix artifact?

  adjust the color Doppler scale

  
• increasing the Color Doppler scale

  decreases the sensitivity of slow flow

  
• describe the effects a normal incidence has on a color Doppler image

  normal incidence: occurs when the angle between the direction of blood flow + the direction of the Doppler sound beam is 90°

  *cosine of 90° = 0: resulting in no Doppler shift + no color filling
• how to fix?

  steering the color box so that the angle of the Doppler sound beams are not parallel to flow will allow for proper color filling

  
• A: proper color Doppler gain

  B: color Doppler gain settings too high

  C: color Doppler gain settings too low

  
• A: proper spectral Doppler gain

  B: spectral Doppler gain settings too high

  C: spectral Doppler gain settings too low

  
• aliasing

  type of Doppler artifact that demonstrates flow both toward and away from the transducer
• wall filter

  • eliminates low frequency Doppler shifts
  • can eliminate venous Doppler shifts as well as artifacts
  • does not affect high velocities
• best angle for better color Doppler shift

  60°
• how to fix?

  wall filter

  
• how to fix?

  wall filter

  
• how to fix?

  wall filter

  
• ..

  A) increase scale

  B) wall filter