Doppler Flashcards
Comparing a reference signal 1/4 out of phase with itself to the returning signal to determine the sign of the Doppler shift
Quadrature phase detection
A machine function that allows for improved measurements of Doppler spectrums related to intracycle or intercycle events
Sweep speed
The combo of the beam width, gate length and pulse length
Sample volume
Equal to 1/2PRF
Nyquist limit
A mathematical means of determine the sign, mean, power and variance of a returning Doppler signal
Autocorrelation
A mathematical process of separating a complex doppler signal into its component frequencies
FFT
The threshold that determines whether the gray scale is displayed in lieu of the colour doppler info
Priority
The shade of the colour represented in colour doppler determining the direction of flow
Hue
A possible artifact that occurs when the PRF exceeds the allowable limit related to the depth of interest.
Range ambiguity
An energy mode that displays the amplitude of the doppler shifts
Power doppler
The amount of velocities that are different from the mean
Variance
An artifact that occurs when the nyquist limit is exceeded by the red blood cell velocities
Aliasing
The brightness of the hue and saturation represented on a colour display
Luminance/Power
The # of pulses per scan line used in colour doppler to calculate the mean
Ensemble length
The amount of colour mixed with white determining the magnitude of the shift
Saturation
