Ch. 26 Density

kkaitlyn96's version from 2017-04-17 01:04

Section 1

Question Answer
What is Density/ ir exposure?overall blackness
what is the range for visible density?.25- 2.5
What is brightness?appearance of density, window leveling, not related to ir exposure
Controlling factor of density?mAs

Section 2

Question Answer
Increase mAs _________ Ir exposure ___ densityincrease, increase; Direct
What is the minimum amount you need to change mAs to see a visible difference in density?30%
increase mA _________ time, What relationship?decrease, indirect
What is the density influencing factor?kVp
kVp increases, electrons _________, energy of beam _________, scatter _________ increases
How does kVp alter the energy of the beam?increase photons produces and increases amount of photons hitting the IR

Section 3

Question Answer
a Single phase generator does what to density?decreases
When should the 15% rule be used?When a change in contrast is wanted
kVp has what relationship with IR exposure?direct
If you decrease kVp by 15% you have to _________ the mAs double
If you increase kVp by 15% you have to _________ the mAshalf

Section 4

Question Answer
Inverse square lawI1/I2= (D2/D1)^2
Direct square lawmAs1/mAs2= (D1/D2)^2
If you double the distance then the density _________reduced by 1/4
If you cut the distance in half then density is _________increased by 4

Section 5

Question Answer
How does OID affect density?Air gap technique decreases density
How does filtration affect density?decreases density
How does beam restriction affect density?decreases density
What do you do when going from a 14x17 to a 8x10?increase mAs by 50%
What do you do when going from a 14x17 to a 10x12?increase mAs by 25%
What relationship does tissue thickness and density have?indirect
Increase grid ratio, _________ frequency, _________ densitydecrease, decrease; inverse
Grid ratio formulamAs1/mAs2= GCF1/GCF2

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