ARDMS SPI Pulsed-Wave and CW Doppler 5

Question 1

A 'tardus-parvus' waveform pattern on spectral Doppler is characterized by:

Accepted Answer

A dampened waveform with slow systolic rise (tardus) and reduced peak amplitude (parvus), seen distal to a significant proximal stenosis

Answer

Tardus-parvus describes the delayed systolic upstroke (tardus = slow) and reduced amplitude (parvus = small) seen in vessels distal to a significant upstream stenosis due to energy loss across the obstruction.

Question 2

In color Doppler imaging, the color assignment (red vs. blue) represents:

Accepted Answer

Flow toward versus away from the transducer

Answer

Color Doppler encodes the mean Doppler frequency shift direction: by convention (BART — Blue Away Red Toward), red indicates flow toward the transducer and blue indicates flow away, regardless of vessel type.

Question 3

Which of the following is a recognized method to correct for aliasing in color Doppler without switching to power Doppler?

Accepted Answer

Increasing the color scale (velocity range / PRF) or shifting the baseline

Answer

Increasing the color scale raises the Nyquist limit for color Doppler, and shifting the color baseline allows more dynamic range in one direction to accommodate higher velocities without aliasing.

Question 4

What is the main advantage of power Doppler over conventional color flow Doppler?

Accepted Answer

It has greater sensitivity for detecting slow or low-volume flow and is less angle-dependent

Answer

Power Doppler displays the amplitude (power) of the Doppler signal rather than the mean frequency shift, making it more sensitive to slow flow and virtually angle-independent, though it sacrifices directional and velocity information.

Question 5

During a renal artery duplex examination, the acceleration time (AT) from a waveform sampled in the intrarenal arteries is measured at 0.12 seconds. This finding is:

Accepted Answer

Abnormal; AT >0.07 s (some labs use >0.10 s) suggests hemodynamically significant proximal renal artery stenosis

Answer

Acceleration time >0.07–0.10 seconds in intrarenal waveforms is associated with proximal renal artery stenosis; the prolonged upstroke reflects dampening of the waveform distal to the obstruction.

ARDMS SPI - ARDMS Sonography Principles and Instrumentation Practice Test

ARDMS SPI - ARDMS Sonography Principles and Instrumentation Practice Test

ARDMS SPI Pulsed-Wave and CW Doppler 5