Lesson 22 (Part 2)

Question 1

Where does the data go for colour doppler once the instrument processes it?

Answer 1

On the display

Question 2

What kind of parameters does colour doppler use? (3)

Answer 2

1. Hue
2. Saturation
3. Luminance

Question 3

Hue

Answer 3

What colour is being displayed

Question 4

Saturation

Answer 4

The amount of colour being shown

Question 5

Luminance

Answer 5

Echo intensity/power/brightness

Question 6

How are stronger echoes demonstrated in colour doppler?

Answer 6

Brighter

- red or white

Question 7

How are weaker echoes demonstrated in colour doppler?

Answer 7

Darker

- grey to black

Question 8

What can be done to affect the effectiveness of the colour doppler examination? (9)

Answer 8

1. Colour box/window
   - size can be changed
2. Map
3. Invert
4. Baseline
5. PRF
6. Aliasing
7. Gain
8. Priority
9. Wall filter

Question 9

What does changing the shape of the colour box/window do? (3)

Answer 9

1. Affects the frame rate
2. Affects temporal resolution
3. Changes the coverage

Question 10

What does a colour map do?

Answer 10

Helps to interpret data

Question 11

What does the colour map interpret? (3)

Answer 11

1. Mean velocities
2. Direction of flow/sign
3. Variance

Question 12

Variance

Answer 12

Change in colour from left to right

Question 13

What is the most commonly used spectrum for colour doppler?

Answer 13

Red to blue

Question 14

What does red represent on the colour map?

Answer 14

A positive shift

- usually

Question 15

What does blue represent on the colour map?

Answer 15

A negative shift

- usually

Question 16

What does invert do in colour doppler?

Answer 16

Flips the colour map

Question 17

What does invert do?

Answer 17

Adjusts the representation

- doesnt change the direction of flow

Question 18

What does baseline mean?

Answer 18

No doppler shift

- zero point

Question 19

Why does baseline help?

Answer 19

IF you have all positive flow you can switch the baseline so there is less blue and more red showing a more detailed map of the flow

Question 20

What does no doppler shift appear as?

Answer 20

Black

Question 21

Can we control PRF in doppler and in 2D?

Answer 21

No, only in doppler

- not in 2D

Question 22

What is the unit for our PRF?

Answer 22

kHz

Question 23

What is the unit for our scale?

Answer 23

cm/s

Question 24

How does changing PRF help in colour doppler?

Answer 24

Can pick up faster or slower speeds by increasing or decreasing the PRF

Question 25

What happens to PRF if we decrease depth?

Answer 25

It increases

- more superficial

Question 26

What happens to PRF if we increase depth?

Answer 26

It decreases

- deeper structures

Question 27

What does PRF change?

Answer 27

Scale

Question 28

What happens to the scale if PRF decreases?

Answer 28

It decreases

Question 29

What happens to the scale if PRF increases?

Answer 29

It increases

Question 30

What is very important about scale?

Answer 30

Having it set appropriately

Question 31

What happens if the scale is too high?

Answer 31

Slower flows go undetected

Question 32

What happens if the scale is too low?

Answer 32

You get artifacts

- alias (faster flows)