Doppler Artifacts

Question 1

Five ways to eliminate aliasing?

Answer 1

1. Increase PRF/scale
2. Shift baseline
3. Lower frequency
4. Use CW
5. Increase doppler angle

Question 2

What is the DS equation?

Answer 2

(2 Fo x V x cos)/prop speed

Question 3

To eliminate aliasing, would you increase or decrease operating frequency?

Answer 3

Decrease

Question 4

To eliminate aliasing, would you increase or decrease the doppler angle?

Answer 4

Increase angle

Question 5

What artifact displayed on spectral shows a doppler signal on the opposite side of a strong reflector?

Answer 5

Mirror image AKA cross-talk

Question 6

What causes mirror imaging in spectral doppler?

Answer 6

1. Increased doppler gains
2. Angles near 90 degrees

Question 7

Mirror image in spectral doppler is AKA ________, and mirror image in colour doppler is AKA ________?

Answer 7

1. Cross talk
2. Ghost artifact

Question 8

What artifact is seen in colour doppler with a sudden movement of tissue?

Answer 8

Flash (clutter)

Question 9

How is flash artifact / clutter eliminated?

Answer 9

Increase wall filter

Question 10

Noise artifact in colour doppler is AKA?

Answer 10

Bleeding or blossoming - reduced by decreasing color gains