Ch. 12 Test Flashcards
Scatter, in the diagnostic range, is mostly due to ____.
compton effect
The two major factors that affect scatter production are ____ and ____.
- tissue volume
- kVp
T/F - Lower kVp creates less scatter.
true
T/F - Higher kVp creates more scatter.
true
Beam restriction does these two things.
- limit patient dose
- reduce scatter
T/F - Collimation and field size are directly proportional.
false
Increasing collimation ____ scatter production.
decreases
Increasing collimation _____ contrast.
increases
T/F - A tightly collimated primary beam uses the same amount of mAs as a poorly collimated primary beam to achieve the same level of exposure.
false
T/F - When increasing collimation, kVp should be increased.
false
Select the item that is not a beam restricting device.
Aperture diaphragm
Cone
Collimator
All of the above
None of the above
none of the above
When using a grid, the radiographer will need to increase _____.
mAs
T/F - Grid use does not increase patient dose.
false
A high grid ratio will clean up ____ scatter.
more
_____ grids can be either long or short dimension.
linear
T/F - Grid cutoff is less likely when using cross-hatched grids, due to their design.
false
T/F - Focused grids can be used at any SID.
false
T/F - Parallel grids can be used at any SID.
true
All of these are stationary grids except for _____.
Wafer grid
Grid cassette
Grid cap
All of the above
None of the above
none of the above
Reciprocating grids are _____.
dynamic
When going from no grid to a 10:1 grid, you have to multiply your original mAs by ____.
5
When going from no grid to a 5:1 grid, you have to multiply your original mAs by ___.
2
When going from no grid to a 16:1 grid, you have to multiply your original mAs by ____.
6
T/F - Off-center grid cutoff is the most common form of grid cutoff.
false
T/F - Off-level grid cutoff is the most common form of grid cutoff.
true
T/F - Air gap technique can be used instead of a grid, and it results in significantly less patient dose.
false
T/F - Using two grids at the same time can cause Moire effect.
true
Fluoroscopy is used to produce ____ images.
dynamic
______ are inversely proportional.
S numbers
_____ are directly proportional.
EI numbers
T/F - Radiographic beam quality has no effect on beam attenuation.
false
T/F - Amorphous selenium is used in direct capture DR.
true
T/F - Amorphous silicon is used in direct capture DR.
false
T/F - Turbid phosphor layers are columnar.
false
T/F - Structured phosphor layers are columnar.
true
