Interaction Flashcards
The reduction in radiation intensity as a result of absorption and scattering
Attenuation
X-ray disappears
Absorption
Partial absorption
Attenuation
Absorbs many x-rays
Radiopaque
Absorbs few x-rays
Radiolucent
What are the 2 factors that determine attenuation?
Atomic number(Z#) - number of protons in the nucleus
Tissue Density
Produced whenever x-rays interact with any type of matter
Secondary radiation
Completely absorbed and energy emitted
Secondary radiation
A type of secondary radiation that only loses some energy and continues in another direction
Scatter radiation
Primary radiation has what type of energy?
Secondary?
High
Low
Occurs within the patient
Secondary radiation
Results in higher patient dose
Secondary radiation
What type of radiation happens to technologists?
Scatter radiation
Passes through the tube housing
Leakage radiation
Passes through the window
Primary radiation
Produced when primary interacts with matter
Secondary radiation
Primary and secondary rays which exit the patient and interacts with technologist
Remnant radiation
Occurs anytime radiation interacts with matter
Secondary radiation
Increases with the use of increased kVp
Secondary radiation
Travels at the speed of light
Secondary radiation
Occurs at lower kVp
Secondary radiation
Increases patient dose
Secondary radiation
What are the five types of interaction energies?
- Classical/Coherent/Thompson
- Photoelectric
- Compton
- Pair production
- Photodisintegration
kVp is lower than 10
Classical interaction
No ionization occurs
Classical interaction
Has low kVp’s
Photoelectric interaction
Interacts with the K shell
Photoelectric interaction
Absorption at the inner K shell
Photo electric interaction
Where secondary radiation occurs
Photoelectric interaction
Is used a lot in mammography
Photoelectric interaction
High contrast
Photoelectric interaction
Dependent on the atomic number
Photoelectric interaction
As atomic number increases, photoelectric absorption ________.
Increases
Deals with higher kVp
Compton interaction
Interacts with the outershell electron
Compton interaction
Results in scatter radiation
Compton interaction
Not useful for images but we have to have it
Compton interaction
Electron diverges at any direction or angle
Compton interaction
Occurs throughout diagnostic range
Compton interaction
Knocks out outershell electrons
Compton interaction
Attenuation
Compton interaction
Increases radiographer dose
Compton interaction
Energies greater than 1.02 MeV
Pair production
Used in nuclear medicine and PET’s
Pair production
What type of atomic number does barium have?
High
Has two positrons and one electron
Pair production
Used in radiation therapy
Photodisintegration
Energies above 10 MeV
Photodisintegration
Interacts with nuclear force field and then disappears
Pair production
Interacts with nucleus
Photodisintegration
Photon absorbed by nucleus and nuclear fragment is emitted
Photodisintegration
Unimportant in diagnostic radiation
Pair production & Photodisintegration