Doppler Instrumentation Flashcards
Operating frequency is ____ related to doppler shift
Directly related
The angle between the source and the reflector is ____ related to the doppler shift
Inversely related
Advantages of pulse wave doppler (2)
Range resolution
Small sample volume
Advantages of power doppler (3)
Increased sensitivity to slow flow
Aliasing & angle independent
Continuous wave advantages (3)
Ability to measure high velocities (no aliasing)
Ability to use high frequencies
Sensitive to low flow velocities
Spectral analysis x and y axis
X is time
Y is frequency shift (velocity)
Spectral / colour advantages
Direction, character, presence, speed blood flow
Colour/spectral disadvantages
Aliasing and Angle dependent
Frame rate
Cont wave disadvantage
Range ambiguity
Power dop disadvantages
No presence, speed, direction, character of blood flow
Pulse wave disadvantage
Aliasing
