# Ch. 26 Density

version from 2017-04-17 01:04

## Section 1

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

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

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

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

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