CT Week 1 Flashcards
1
Q
mAs must be changed by a minimum of how much to see a visible change?
A
30%
2
Q
Doubling or halving mAs will change density by a factor of
A
2
3
Q
Attenuation
A
Degree to which an x-Ray beam is reduced by an object
4
Q
Air has a CT value of
A
Minus 100
5
Q
Atoms with a higher atomic number will absorb —
A
More
6
Q
Compton’s scattering occurs when KV is —
A
High KV
7
Q
Photoelectric effect occurs when KV is —
A
Low KV
8
Q
Radiographic contrast is a product of
A
- Subject contrast
2. IR or film contrast
9
Q
Subject contrast
A
Difference in x-Ray beam INTENSITY due to attenuation by the body part
10
Q
Subject contrast depends on
A
kV
Tissue thickness
Tissue density
Atomic number
11
Q
On a low contrast image the bifference between adjacent densities is
A
Small
