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Physics
Ch. 7 and 8
Question | Answer |
---|---|
Image contrast is affected by | beam quality and kVp |
An increase in kVp would ____ the _____ of the emission spectrum | increase; amplitude and position |
The HVL of an x-ray beam is a measurement of beam | energy |
An increase in mAs would ____ the ______ of the emission spectrum | increase; amplitude alone |
Beam energy is affected by | kVp and filtration |
The ____ of an x-ray beam is higher when the peak of the emission spectrum is further to the ____ | quality; right |
An exposure taken at 100 kVp would have a continuous emission spectrum with a maximum energy of _____ keV | 100 |
A low-quality beam would also have low _____ | penetrability |
An x-ray beam that could pass through dense tissue would have high ___ | penetrability and quality |
The quantity of bremss radiation increases proportionately with increased | mAs |
The penetrability of an x-ray beam is called x-ray | quality (controlled by kVp) |
Characteristic x-rays are produced by | released binding energy |
X-ray intensity is proportional to | kVp2 |
Bremss x-rays are produced by _____ at the target | slowing electrons |
If an exposure is 0.5 mGy at an SID of 40, what would the exposure be at an SID of 60 | 0.222 mGy |
At 55 kVp, _____ of the x-rays produced are bremss | 100% |
Most of the x-rays produced at the target are | bremss |
If the intensity of a 70 kVp exposure at 20 mAs is 1.0 mGy, what would it be at 5mAs | 0.25 mGy |
Characteristic K-shell x-rays have an effective energy of ____ keV | 69.5 |
An increase of 15% in kVp is equivalent to increasing mAs | 100% |
The useful characteristic x-rays from tungsten targets are ___-shell x-rays | K |
The inverse square law has the same effect on x-ray ____ and x-ray ____ | intensity;exposure |
If a technologist changes the technique from 70 kVp @ 200 mAs to 70 kVp @ 400 mAs, the x-ray intensity will | double |
Electron interactions at the inner shell of the target atoms produce ____ radiatio | characteristic |
If the quantity of electrons hitting the target is doubled, the x-ray intensity is | increased by a factor of 2 |
Approximately ____ of the kinetic energy of the projectile electrons is converted to x-rays at the target | 1% |
A 10% increase in kVp has ___ effect on x-ray intensity than/as a 10% increase in mAs | much greater |
The efficiency of x-ray production increases as ____ increases | kVp |
If filter thickness is _____ then x-ray intensity is ____ | increased; reduced reduced; increased |
The production of heat at the anode is directly proportional to | tube current |
Most of the heat generated at the target is due to | outer-shell excitation |
The efficiency of x-ray production is ____ the tube current | not affected by |
At the target, the projectile electrons interact with | inner-shell and outer-shell electrons |
During an exposure, most of the ____ energy of the projectile electrons is converted to ____ | kinetic; heat |
Projectile electrons travel from | cathode to anode |
If the SID is reduced by half, how is the x-ray intensity at the image affected | increased 4 times |
X-ray intensity increases in direct proportion to increases in | mAs |
The number of x-rays in the useful beam defines x-ray | intensity (same as quantity) |
Grays, or milligrays, in air are the measurement for x-ray | quantity, exposure, and intensity |