| Question | Answer |
| What are the two principal factors that affect the amount of scatter produced? | kilovoltage and irradiated material |
| How does the atomic number of a material affect the amount of scatter produced? | Higher atomic number materials= a greater number of electrons within each atom, which means photons have a greater chance of striking an electron and interacting with these materials, creating more scatter |
| Collimators with automatic controls are called? | Positive Beam limitation (PBL) |
| What happens to the transmisssion of photons when kVp is increased with no other change in the technical factors for an exposure? | increases transmission |
| What happens to the amount of scatter created in an increase in kVp is combined with a reduction in mAs? | it decreases scatter |
| The mounting mirror that supplies the light field in the collimator is placed at a ______ angle.
1. 30
2. 40
3. 45
4. 50 | c. 45 degree |
| The beam is automatically collilmated to the size of the image receptor using what? | Positive beam limitation (PBL) |
| What is the simplest of all beam restrictors?
a. cones
b. aperture diaphragm
c. cylinders
d. collimator | b. aperture diaphragm |
| What is the geometric unsharpness around the edge of an image known as? | Penumbra |
| What happens to scatter radiation if the amount of irradiated tissue increases? | increases scatter radiation |
| What factor(s) that has/have an effect on the amount of scatter generated is/are under the direct control of the radiographer?
a. atomic number
b. medical condition
c. patient size
d. field size and kVp | d. field size and kVp |
| A set of lead shutters at right angles to one another that move in opposing pairs | collimator |
| Exposure Factors
Chapter 15 - Beam Restriction | |
