X-ray production interaction with matter Flashcards
Penetration passes through unchanged due to two factors:
- x-rays are electrically neutral (not affected by e- or + nucleus)
- Atoms consist mainly of empty space
The probability of penetration increases with:
A. higher quantity of short wavelength radiation (high frequency)
B. less tissue thickness
c. lower tissue density (Z)
Higher quantity of short wavelength radiation (high frequency) increases
Kvp, filtration, z of the target
Attenuation due to 3 factors
A. absorption of part of the primary beam within atoms of the body with resultant formation of secondary radiation
B.part of the radiation undergoes a change in direction with resultant formation of scatter radiation (compton, coherent)
C. inverse square law
Attenuation: exposure rate _____
decreases
Photoelectric effect (true absorption) results in
A. Characteristic radiation (true secondary radiation)
B. Photoelectron (neg Ion)
C. Positive ion
The probability of photoelectric effect increases with:
a. having atoms with a high Z
b. the incident photon having a KeV equal or slightly greater than the binding energy of the inner shell electron
c. lower energy x-ray photons
Compton interaction (compton effect, compton, modified scatter) modified in two ways:
Energy of it and the direction it goes
Compton interaction results
A. scattered photon (aka compton photon)
B. Recoil Electron
C. positive Ion
The energy or the scattered photon will be dependent in its _________
angle of deflection
If the photon just glances off the e- and is scattered by a small angle, it will retain at _____ of its original energy
large amount
The larger the angle, the less energy it will reatin and the ___ energy is transmitted to recoil electrons
more
THe scatter photon will retain up to____ of its original energy
~2/3
What happens to the scattered photon?
A. i can be transmitted through matter
b. it can be absorbed in a photoelectric interaction with another atom
C. it may result in further compton interactions
The probability of compton scatter is a complex function of _____________________________.
the energy of the incident x-ray
In general the probability of the compton effect decreases a x-rays energy ___________
increases
As KVP is increased, the probability of compton interaction _______
decreases
The probability of compton scattering ____________ depend on the z# of the atom involved
does not
WIth higher KVP, the compton photons that do occur have_____energy, and tend to be scattered more and more in a _____ direction, increasing the likelihood of their possing completely through the body and reaching the image receptor
more; forward
Constitutes the scattered radiation which in radiology, impairs image contrast by an overall fogging effect–> a form of noise that degrades _______
recorded detail
