Chapter 4 Doppler Waveform Analysis Flashcards
When a wave is reflected from a moving target the frequency of the wave received is different from the transmitted wave describes
The Doppler effect
What effect occurs with relative motion between the source and the receiver of the sound
Doppler effect
What type of Doppler velocimetry employs a zero crossing frequency meter to display the signals graphically and a strip chart recorder
Analog
During spectral analysis individual frequencies are displayed by using what method
Fast Fourier method (FFT)
During spectral analysis time is displayed on what axis
Horizontal or X
During spectral analysis frequency shifts are displayed on what axis
Vertical axis or Y
During a Doppler waveform analysis what frequency probe is utilized
8-10 MHz
A monophasic/dampened signal is often obtained ________ to an obstruction
Proximal
Vasodilation of the ______ vessels often occur with proximal obstruction reducing the pulsatility
Distal
What type of flow does the subclavian artery have
High resistant multiphasic flow
Absent Doppler signals may suggest occlusion or a pre-occlusive vessel that is called what
String sign
How do you calculate the pulsatility index
Divide the peak to peak frequency difference (P1-P2) by the mean average frequency
This helps to differentiate inflow (aorto-iliac) disease from out flow (s-femoral) disease
Acceleration time
An angle of insonation of ______ to the ski n surface is usually appropriate for this study
45-60 degrees
The advantage of spectral analysis is that it shows the ________ at all _________
Amplitude at all frequencies
Spectral analysis is ______ sensitive to displaying multiple frequencies
More
The upper and lower extremity arteries have ________ resistance flow patterns
Higher
The _______ sign is a pre occlusive lesion that may still have very slow velocities moving through it
String
Arterial vasodilation is ______ resistance
Low
What upper extremity artery is characterized by multi phasic high resistance flow
Subclavian artery
A normal pulsatility index for the CFA is
Greater than 5.5
A normal pulsatility index for the popliteal artery is
8.0
_______ ________ factor is the ratio of the distal pulsatility index of the proximal pulsatility index of an arterial segment
Inverse damping
An acceleration time of > 133 msec suggests the presence of significant ______ disease
Iliac
_______ _______ helps to differentiate inflow from our flow disease
Acceleration time
