Lecture 23 Part 2

Question 1

Gate size/ sample volume affects

Answer 1

Range resolution

Question 2

What is range resolution

Answer 2

Knowing exactly where the signal is coming from

Opposite of range ambiguity

Question 3

What is gain

Answer 3

Amplification of incoming echoes’ voltages

Question 4

What is invert

Answer 4

Arteries are generally positive signals -> above the baseline

Veins are generally negative signals—> below the baseline

Question 5

What is baseline

Answer 5

Zero point

Eg. More positive signals can move baseline down

Question 6

What is wall filter

Answer 6

Cuts off slower flows

Used to get rid of clutter (tissue motion, valves)

Question 7

Wat does PRF affect as a spectral control

Answer 7

PRF affects scale -> which velocities we can display

Question 8

Decreasing the PRF, decreases the ______ which is useful whe n_______

Answer 8

Decreases the scle

Usefull when trying to show slower speeds

Decreasing the PRF too much will cause aliasing -> wrap around

Question 9

Any doppler shift _____ the Nyquist limit will alias

Answer 9

Over

Question 10

Increase the PRF when trying to show

Too much PRF will cause

Answer 10

Trying to show faster flow speeds

Increasing the PRF too much will produce a poor signal —> wasted space

Question 11

Increasing the angle = _______ doppler shift

Answer 11

Decreases

Question 12

Angle correct makes

Answer 12

Doppler shift seem lower than it is

``

Question 13

_____ is calculated from the doppler shift

Answer 13

Velocity

Question 14

Correcting the angle brings the calculated speed ________ to its true value

Answer 14

Back up

Question 15

Spectral doppler can also be converted to

Answer 15

Audible signal

Question 16

Higher freq = higher ________ in audible sound

Answer 16

Higher pitch

Question 17

________ often useed aas another type of “display”

Answer 17

Loudspeakers

Question 18

Doppler shifts are in _______ —> which is in

Answer 18

KHz

Within our audible range

Question 19

Spectral controls : Volume

Answer 19

Audible signal can be turned up or down

We can listen for areas of high speeds (higher pitched )