CCI Ultrasound Physics and Instrumentation 3

Question 1

What happens to the Doppler angle as it approaches 90 degrees relative to blood flow?

Accepted Answer

Measured velocity approaches zero regardless of true velocity

Answer

The Doppler equation includes the cosine of the angle; at 90°, cos(90°) = 0, so the detected Doppler shift becomes zero regardless of actual blood velocity.

Question 2

Which transducer type is most commonly used for adult transthoracic echocardiography?

Accepted Answer

Phased array

Answer

Phased array transducers use electronic steering to create a small footprint with a wide sector image, making them ideal for imaging through narrow intercostal spaces.

Question 3

In color flow Doppler, the variance map (green) indicates:

Accepted Answer

Turbulent or disturbed flow

Answer

Green color or color variance in the color flow map indicates turbulent or disturbed flow with multiple velocities present within the sample volume.

Question 4

The lateral resolution of an ultrasound beam is primarily determined by:

Accepted Answer

Beam width at a given depth

Answer

Lateral resolution equals the beam width at the depth of the target; objects closer together than the beam width cannot be resolved as separate structures.

Question 5

Which statement about continuous wave (CW) Doppler is correct?

Accepted Answer

It can measure very high velocities without aliasing

Answer

CW Doppler continuously transmits and receives without pulsing, so it has no PRF limit and can accurately measure very high velocities without aliasing.

CCI - Cardiovascular Credentialing International Practice Test

CCI - Cardiovascular Credentialing International Practice Test

CCI Ultrasound Physics and Instrumentation 3