Physics Ch 8 Flashcards
Roentgens (or grays) are the measurement for x-ray ____.
- quantity
- exposure
- intensity
- all of the above (correct answer, your response)
The number of x-rays in the useful beam defines x-ray _____.
quantity
Standard x-ray machines produce about ______ mR/mAs at 70 kVp measured at 100 cm SID.
5
X-ray quantity increases in direct proportion to increases in ______.
mAs
If the distance from the source to the image (SID) is reduced by half, how is the x-ray intensity at the image affected?
It is increased 4 times
If filter thickness is ____, then x-ray intensity is ______.
- reduced, reduced
- increased, reduced
- reduced, increased
- both b and c (correct answer)
A 10% increase in kVp has ____ effect on x-ray intensity than/as a 10% increase in mAs.
much greater
If x-ray quantity is doubled, the optical density on the finished radiograph will be ______.
increased by a factor of two
If a technologist changes the technique from 70 kVp @ 200 mAs to 70 kVp @ 400 mAs, the x-ray intensity will _____ and optical density will _____.
double, double
The inverse square law has the same effect on optical density and x-ray ______.
intensity
• expousure
• quantity
• all the above (correct answer
An increase of 15% in kVp is equivalent to increasing mAs _____.
100%
If the intensity of a 70 kVp exposure at 2 mAs is 100 mR, what would be 25 mR at 5 mAs?
25mR
If an exposure is 50 mR at an SID of 40 inches, what would the exposure be at an SID of 60 inches?
22.2 mR
X-ray intensity is proportional to ______
kVp^2
The penetrability of an x-ray beam is called x-ray ________.
quality
An x-ray that could pass through thick tissue would have high ____.
- penetrability
- quality
- quantity
- both A and B (correct answer)
A low quality beam would also have low _______
penetrability
Beam quality is affected by ____.
kVp and filtration
The half value layer (HVL) of an x-ray beam is a measurement of beam ______.
quality
Image contrast is affected by _______.
- beam quality
- kVp
- mAs
- both A and B (correct answer)
The HVL is lowered by a decrease in ______.
kVp
X-ray beam quality is improved by ______.
increasing filtration
The main purpose of added filtration is to reduce _____.
beam penetrability
Added filtration will ____ beam quality and _______ beam quantity.
increase, decrease
A compensation filter is used to create _____ optical density with a body part of ______ thickness.
uniform, non-uniform
