scatter control Flashcards
when you increase kVp, you _________ scatter
increase (increase Compton interactions, lower photoelectric)
when you increase field size, you _________ scatter
increase
increased anatomy part _________ scatter
increases
digital imaging is (more/less) sensitive to scatter
more
patient dose will ___________ with increased collimation
decrease
scatter radiation will ___________ with increased collimation
decrease
radiographic contrast will ___________ with increased collimation
increase
exposure to IR will ___________ with increased collimation
decrease
patient dose will ___________ with increased x-ray field size
increase
scatter radiation will ___________ with increased x-ray field size
increase
radiographic contrast will ___________ with increased x-ray field size
decrease
exposure to IR will ___________ with increased x-ray field size
increase
x-ray field size and collimation are ________
inverse; to increase the field size you decrease collimation
collimators are ____ shutters that sit between the ____________
lead, tube and window
what does PBL stand for?
positive beam limiting
what is PBL?
in DR, when you select an exam it automatically gives you the space for that exam and limits you from going beyond that size
flat piece of lead that contains a hole
aperture diaphragm
lead = diaphragm
hole = aperture
are apertures used commonly in x-ray?
no, but may be present in dental settings
true/false: aperture diaphragms are adjustable
false, they are not
an aperture diaphragm that has an extended flange attached to it
cone/cylinder
________ are better at limiting un-sharpness than a ________
cylinders, cone
grids ___________; ____ absorb
clean up scatter, lead strip
use of grid requires ______
more mAs
when do you use a grid?
part is over 10cm, greater than 60 kVp
linear pattern of the lead lines of a grid
grid pattern
with air-gap technique, mAs increased ____ for every cm of air gap
10%
types of grid patterns
linear, crosshatch
grid ratio = _____
h/D
orientation of the lead lines relative to one another
grid focus
types of grid focus
parallel/nonfocused, focused
the number of lead lines per unit length
grid frequency
with an increased amount of lines, you decrease _______________
visibility of grid lines on x-ray
Grid Ratio –> GCF/Bucky Factor
No Grid =
1
Grid Ratio –> GCF/Bucky Factor
5:1 =
2
Grid Ratio –> GCF/Bucky Factor
6:1 =
3
Grid Ratio –> GCF/Bucky Factor
8:1 =
4
Grid Ratio –> GCF/Bucky Factor
12:1 =
5
Grid Ratio –> GCF/Bucky Factor
16:1 =
6
