Lesson 22 (Part 2) Flashcards
Where does the data go for colour doppler once the instrument processes it?
On the display
What kind of parameters does colour doppler use? (3)
- Hue
- Saturation
- Luminance
Hue
What colour is being displayed
Saturation
The amount of colour being shown
Luminance
Echo intensity/power/brightness
How are stronger echoes demonstrated in colour doppler?
Brighter
- red or white
How are weaker echoes demonstrated in colour doppler?
Darker
- grey to black
What can be done to affect the effectiveness of the colour doppler examination? (9)
- Colour box/window
- size can be changed - Map
- Invert
- Baseline
- PRF
- Aliasing
- Gain
- Priority
- Wall filter
What does changing the shape of the colour box/window do? (3)
- Affects the frame rate
- Affects temporal resolution
- Changes the coverage
What does a colour map do?
Helps to interpret data
What does the colour map interpret? (3)
- Mean velocities
- Direction of flow/sign
- Variance
Variance
Change in colour from left to right
What is the most commonly used spectrum for colour doppler?
Red to blue
What does red represent on the colour map?
A positive shift
- usually
What does blue represent on the colour map?
A negative shift
- usually
What does invert do in colour doppler?
Flips the colour map
What does invert do?
Adjusts the representation
- doesnt change the direction of flow
What does baseline mean?
No doppler shift
- zero point
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
What does no doppler shift appear as?
Black
Can we control PRF in doppler and in 2D?
No, only in doppler
- not in 2D
What is the unit for our PRF?
kHz
What is the unit for our scale?
cm/s
How does changing PRF help in colour doppler?
Can pick up faster or slower speeds by increasing or decreasing the PRF
