Dynamic Range Flashcards
(16 cards)
What does a high dynamic range ultrasound look like?
What does a low dynamic range look like?
If there was only 2 choices of gray, how would the image look like?
If only two, the image would have a lot of contrast, black or white.
If there were more grays available, how would an image look like?
The image would show much more texture.
What does the dynamic range of grays affect?
It affects the number of grays available to compare echoes.
What is compression?
It is the technique that changes the dynamic range so that all parts of the equipment are on the same scale.
How do you find the compression range?
uncompressed original range - compression= compression range (will be compressed, so it will be smaller)
How do you find the original uncompressed range?
compressed range + compression= uncompressed range (the original is larger before it was compressed)
If you start with DR 100 dB and compressed 60 dB, the compressed DR is?
40 dB→100-60=40
If a compressed signal has a DR of 140 dB and the original signal was compressed by 30 dB, then the original DR was?
170 dB→140+30=170
What does a wide dynamic range give?
It will give you many shades of gray in the image so that you can appreciate different tissue textures.
What kind of contrast does a wide dynamic range give?
Low contrast because it shows a pleutra of grays.
What does a narrow dynamic range give?
It will give you few shades of gray in the image so that you can basically only see black or white which leads you to see little or no texture.
What kind of contrast does a narrow dynamic range show?
It shows a high contrast image. This means its only black and white, no grays.
Give an example where low contrast is benefical?
It is helpful to see differences in plaque.
Give an example where high contrast is beneficial.
May be helpful to do vein compressions so you can se the thin venous walls better.
