CET Doppler Echocardiography & Spectral Analysis

Question 1

Which Doppler modality is best suited for measuring high-velocity jets such as severe aortic stenosis?

Accepted Answer

Continuous-wave Doppler

Answer

Continuous-wave Doppler has no aliasing limit and can accurately measure high-velocity jets exceeding the Nyquist limit.

Question 2

The Nyquist limit in pulsed-wave Doppler is equal to:

Accepted Answer

One-half the pulse repetition frequency (PRF/2)

Answer

Aliasing occurs when the sampled velocity exceeds half the PRF (Nyquist limit), causing velocity wrap-around on the spectral display.

Question 3

On a pulsed-wave Doppler spectral display, flow moving toward the transducer is displayed:

Accepted Answer

Above the baseline

Answer

By convention, flow directed toward the transducer produces a positive Doppler shift and is displayed above the baseline.

Question 4

Which of the following best describes the term 'angle of incidence' in Doppler echocardiography?

Accepted Answer

The angle between the ultrasound beam and the direction of blood flow

Answer

The angle of incidence is the angle between the ultrasound beam and the direction of blood flow; accuracy is greatest when this angle is less than 20 degrees.

Question 5

The modified Bernoulli equation used in echocardiography is expressed as:

Accepted Answer

ΔP = 4V²

Answer

The simplified Bernoulli equation ΔP = 4V² converts peak Doppler velocity (m/s) to pressure gradient (mmHg), widely used to estimate stenotic and regurgitant jet gradients.

(CET) Certified Echocardiography Technician Practice Test

(CET) Certified Echocardiography Technician Practice Test

CET Doppler Echocardiography & Spectral Analysis