What are the three main types of x-ray interactions that occur within the patient?
Photoelectric effect, Compton effect, and Thompson effect
100
What are two other names for the Compton Effect?
Modified scattering and incoherent scatters
100
The Thompson effect is responsible for what percentage of scatter?
1%
100
Define secondary radiation
Any radiation resulting from interactions within the body
100
If you increase tissue thickness, tissue density, and/or tissue atomic number, what will happen?
Increase in scatter, longer gray scale, less blacks and whites
200
What is the photoelectric effect responsible for?
The photoelectric effect produces the contrast on the images
200
The Compton Effect is responsible for what percentage of the scatter?
99%
200
At what kVp does the Thompson effect occur at?
70 kVp and above
200
Define remnant radiation
Radiation emitted in the direction of the primary beam
200
What happens to contrast, gray scale, wavelength, and penetration when kVp is increased?
decreased contrast
long gray scale
shorter wavelength
greater penetration
300
The photoelectric effect is responsible for what colors on the image?
All blacks and whites
300
What kVp does the Compton Effect occur at?
70 kVp and above
300
Describe the Thompson effect
The photon has less energy than the electron it interacts with, hence increasing the energy of the electron, which is released as a scatter photon
300
Define scatter radiation
Radiation emitted in a direction that differs from its' original direction
300
What effect does increasing the x-ray beam energy (kvp) have on the proportion of Compton scatter interactions compared to photoelectric interactions?
Compton Effect is increased and Photoelectric effect is decreased
400
What must the kVp be for photoelectric effect to occur?
<70 kVp
400
Describe the Compton Effect
Produces a recoil electron and a Compton photon when the incoming photon has more energy than the electron in an outer shell
400
What is a vague description of the other interactions?
Can produce characteristic interactions similar to that which occurs in the anode
400
What has the greatest influence over "overall contrast"
Absorption
400
What effect does increasing the x-ray beam energy (kVp) have on the total number of all interactions within the patient?
Decreases
500
Describe the photoelectric effect
When the photon is absorbed by an inner-shell electron, which then increases it's energy to the point the electron is ejected out as a photoelectron. The photoelectron then collides with another atom and never leaves the body.
500
What are 3 other names for the Thompson effect?
unmodified scattering, coherent scattering, and classical scattering.
500
What are two examples of other interactions?
Pair production and photodisinegration
500
What are the three factors in subject contrast?
Tissue thickness, tissue density, tissue atomic number
500
A photon with much more energy than the electron binding energies of the tissue through which it passes is most likely to undergo what type of interaction?