Lesson 22 (Part 2) Flashcards Preview

Physics 1 > Lesson 22 (Part 2) > Flashcards

Flashcards in Lesson 22 (Part 2) Deck (32)
Loading flashcards...
1

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

On the display

2

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

1. Hue
2. Saturation
3. Luminance

3

Hue

What colour is being displayed

4

Saturation

The amount of colour being shown

5

Luminance

Echo intensity/power/brightness

6

How are stronger echoes demonstrated in colour doppler?

Brighter
- red or white

7

How are weaker echoes demonstrated in colour doppler?

Darker
- grey to black

8

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

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

9

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

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

10

What does a colour map do?

Helps to interpret data

11

What does the colour map interpret? (3)

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

12

Variance

Change in colour from left to right

13

What is the most commonly used spectrum for colour doppler?

Red to blue

14

What does red represent on the colour map?

A positive shift
- usually

15

What does blue represent on the colour map?

A negative shift
- usually

16

What does invert do in colour doppler?

Flips the colour map

17

What does invert do?

Adjusts the representation
- doesnt change the direction of flow

18

What does baseline mean?

No doppler shift
- zero point

19

Why does baseline help?

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

20

What does no doppler shift appear as?

Black

21

Can we control PRF in doppler and in 2D?

No, only in doppler
- not in 2D

22

What is the unit for our PRF?

kHz

23

What is the unit for our scale?

cm/s

24

How does changing PRF help in colour doppler?

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

25

What happens to PRF if we decrease depth?

It increases
- more superficial

26

What happens to PRF if we increase depth?

It decreases
- deeper structures

27

What does PRF change?

Scale

28

What happens to the scale if PRF decreases?

It decreases

29

What happens to the scale if PRF increases?

It increases

30

What is very important about scale?

Having it set appropriately