Spectral Doppler Waveform Analysis Flashcards
7 cards from real ARDMS SPI practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Spectral Doppler Waveform Analysis flashcards as text
When the Doppler angle correction cursor is positioned at 90 degrees, the calculated velocity will be:
Answer: Infinite or mathematically undefined
At 90 degrees, cos(90°) = 0, making the denominator of the Doppler equation zero, which produces a mathematically undefined (infinite) velocity value.
Increasing the wall filter setting on a spectral Doppler display will:
Answer: Remove low-frequency signals from the spectral display
The wall filter (high-pass filter) eliminates low-frequency Doppler signals produced by slow-moving vessel walls and surrounding tissue, reducing clutter near the baseline.
A 'tardus parvus' waveform observed distal to a stenosis is characterized by:
Answer: Decreased PSV with prolonged systolic acceleration time
Tardus parvus (Latin: slow-small) describes the dampened, delayed post-stenotic waveform with reduced peak systolic velocity and a slow, rounded systolic upstroke.
To correct aliasing on a spectral Doppler display, which of the following would NOT be an effective solution?
Answer: Decreasing the sample volume gate size
Decreasing sample volume size changes the amount of vessel sampled but does not affect the PRF or the Nyquist limit, making it ineffective for correcting aliasing.
In a standard spectral Doppler display, the vertical (y-axis) represents:
Answer: Doppler frequency shift (displayed as velocity after angle correction)
The y-axis in spectral Doppler displays the Doppler frequency shift, which is converted to velocity using angle correction, while the x-axis represents time.
On a spectral Doppler display, flow moving AWAY from the transducer will appear:
Answer: Below the baseline as a negative deflection
By convention, flow toward the transducer produces a positive frequency shift and appears above the baseline, while flow away from the transducer produces a negative shift and appears below the baseline.
Which of the following best describes a low-resistance Doppler waveform?
Answer: Continuous forward flow throughout diastole with elevated end-diastolic velocity
Low-resistance organs (kidney, brain, liver) require constant blood supply and maintain continuous forward flow throughout diastole, producing waveforms with elevated end-diastolic velocities.