Chapter 3 - Interactions exposure
Which type of interaction of x-rays with matter is responsible for the majority of the occupational dose to the technologist?
Compton
Five types of x-ray interactions with matter.
Compton; Photoelectric; Pair Production; Coherent; Photodisintegration
Most of the e- produced at anode.
Bremsstrahlung
Classic, unmodified, Thompson, and Rayleigh scatter.
Coherent
No ionization. No electrons leave or enter atom. small change in direction of photon. essentially no role in diagnostic radiology.
Coherent
Although ______ ______ is nonionizing and insignificant from an image formation standpoint, this interaction does not occur throughout the diagnostic energy range.
Coherent Scattering
Outer shell action. Higher energy photon than photoelectric.
Compton
Photon loses some energy; knocks e- out; then scatters.
Compton
Which of the following has the greatest adverse effect on radiographic contrast?
Compton
Which of the following interactions necessitates the use of the protective lead aprons for personnel during fluoroscopy?
Compton
Which of the x-ray interactions with matter does most of the scattered radiation in the diagnostic range occur?
Compton
The Compton effect is an interaction with an ______ shell electron and the photoelectric effect is an interaction with an ______ shell electron.
Outer/inner
1.022 MeV energy of incoming photon. Nuclear reaction yields positron/negatron pair.
Pair Production
Positron annihilates a nearby e- = two 511 keV photons traveling in opposite directions (180 degrees).
Pair Production
Used in PET imaging
Pair Production
Two x-ray interactions that do not occur in the diagnostic energy range.
Pair Production and Photodisintegration
Which of the interactions is an interaction with the atomic nucleus with the results being a positron and a negatron (electron)?
Pair production
High energy incoming photon goes to nucleus. Nucleus loses a neutron or proton and becomes radioactive.
Photdisitegration
Nuclear reaction most useful in radiation therapy.
Photodisintegration
Electron is ejected as a photoelectron - leaving behind a hole in the inner shell.
Photoelectric
Hole is filled with e- from outer shell - energy is emitted as a characteristic photon.
Photoelectric
In which of the x-ray interactions with matter is the energy of the incident photon completely absorbed by an electron?
Photoelectric
Total absorption of an x-ray.
Photoelectric
Which of the interactions is responsible for radiographic contrast?
Photoelectric
Which of the photon -tissue interactions results in the ejection of a K shell electron?
Photoelectric
Which of the following types of interactions would occur in the diagnostic x-ray range, (50 to 150 kVp)?
Photoelectric; Compton
Inner shell action - incoming photon gives all its energy to inner shell e-. (it is absorbed)
Photoelectron
During the process of coherent scattering, how does the energy of the resulting scattered wave/photon compare to the energy of the incident or original photon?
Stays the same