VT Diagnostic Imaging Techniques 2

Question 1

Which Doppler mode provides a visual map of flow velocities superimposed on a B-mode image?

Accepted Answer

Color flow Doppler

Answer

Color flow Doppler encodes velocity and direction as colors overlaid on the grayscale B-mode image.

Question 2

A vascular sonographer notes aliasing on color Doppler. The BEST corrective action is to:

Accepted Answer

Increase the color scale (PRF)

Answer

Aliasing occurs when the PRF is too low; increasing the color scale (PRF) raises the Nyquist limit and eliminates wrap-around.

Question 3

Which imaging modality uses gadolinium contrast and is considered the gold standard for evaluating renal artery stenosis in patients who cannot receive iodinated contrast?

Accepted Answer

MR angiography

Answer

MR angiography with gadolinium provides excellent vessel detail without iodinated contrast, making it preferred for patients with iodine allergy.

Question 4

The angle of insonation recommended for accurate arterial Doppler velocity measurements is:

Accepted Answer

60 degrees or less

Answer

A Doppler angle of 60 degrees or less is used because angles above 60 degrees introduce large cosine-related velocity errors.

Question 5

B-flow imaging (B-flow) differs from color Doppler in that it:

Accepted Answer

Displays moving blood without Doppler processing

Answer

B-flow uses coded excitation to directly visualize moving blood cells in grayscale without Doppler processing, providing high temporal resolution.

(VT) Vascular Technician Certification Practice Test

(VT) Vascular Technician Certification Practice Test

VT Diagnostic Imaging Techniques 2