Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
18 Cards in this Set
- Front
- Back
What are the five quality factors of an image? |
|
|
What three things affect חדות? |
|
|
What affects geometric חדות? |
|
|
There is always some ____ in an x-ray. |
magnification |
|
When the object is farther from the film, there is ____ magnification. When the tube is farther from the film, there is ____ magnification. |
more, less |
|
Magnification = |
FFD / FFD - OFD |
|
Reducing magnification improves _____. |
geometric resolution. |
|
What are the two ways to improve geometric resolution? |
|
|
What is a half shadow? |
Penumbra--the shadow surrounding an object, appears as a blurry border. |
|
What is the record of the actual object called? |
Umbra |
|
Half shadow - Geometric resolution ? |
Half shadow -Geometric resolution + |
|
What are three ways to reduce penumbra? |
|
|
For low magnification and small half shadow, use a ____ and a _____. |
short OFD, small focal spot |
|
Distortion refers to _____. |
wrong shape, wrong size (magnification), or wrong position |
|
Distortion can be caused by a tilted ____ . |
object OR film |
|
True or false. Some distortion always occurs. |
True |
|
We can counter distortion by _____. |
Taking two x-rays |
|
Explain what geometric resolution is and how we can improve it. |
|