ARDMS SPI - ARDMS Sonography Principles and Instrumentation Pulsed-Wave and CW Doppler Questions and Answers

Question 1

Which of the following is a primary advantage of Continuous-Wave (CW) Doppler over Pulsed-Wave (PW) Doppler?

Accepted Answer

It is not limited by aliasing at high velocities.

Answer

It provides superior range resolution.

Answer

It uses a single crystal for both transmission and reception.

Answer

It offers better axial resolution in the image.

Question 2

A sonographer observes that the spectral waveform on a Pulsed-Wave Doppler display appears to "wrap around" from the top of the scale to the bottom. This artifact is known as:

Accepted Answer

Aliasing

Answer

Range ambiguity

Answer

Spectral broadening

Answer

Crosstalk

Question 3

A sonographer is performing a PW Doppler examination and notes significant aliasing. Which of the following adjustments is LEAST likely to correct this artifact?

Accepted Answer

Increasing the overall Doppler gain.

Answer

Increasing the Pulse Repetition Frequency (PRF).

Answer

Shifting the spectral baseline.

Answer

Switching to a lower frequency transducer.

Question 4

Which of the following statements accurately describes a key characteristic of Continuous-Wave (CW) Doppler?

Accepted Answer

It cannot determine the exact depth from which a velocity signal originates.

Answer

It utilizes a single piezoelectric element that alternates between sending and receiving.

Answer

It is limited by the Nyquist criterion for high-velocity measurements.

Answer

It provides excellent range resolution by using a small sample volume.

Question 5

A Pulsed-Wave Doppler system is operating with a Pulse Repetition Frequency (PRF) of 12 kHz. What is the maximum Doppler shift that can be displayed without aliasing?

Accepted Answer

6 kHz

Answer

12 kHz

Answer

24 kHz

Answer

3 kHz

Question 6

A sonographer is tasked with measuring the peak velocity of a severe aortic stenosis jet, which is expected to be approximately 4 m/s. Which Doppler modality is most appropriate for this measurement and why?

Accepted Answer

Continuous-Wave Doppler, because it is not subject to aliasing and can measure very high velocities.

Answer

Pulsed-Wave Doppler, because its specific sample volume can be placed precisely in the jet.

Answer

Power Doppler, because it is most sensitive to the presence of flow.

Answer

Color Flow Doppler, because it can visualize the turbulent flow pattern.