Test 4 Flashcards
The source of Kinect of energy
Projectile electrons
As Kvp increases, the ________ energy of projectile electrons
Higher
Electrons travel at —— speed of light
_______ travel at the speed of light
1/2
Xrays
Electrons emitted by the filament and directed to the target (cathode to anode)
Projectile electrons
The strength of attachment of electrons to the nucleus
Binding energy
X-rays produced by transitions of orbital electrons from the outer to inner shells
Characteristic X-rays
X-rays produced by interaction of a projectile electron with a nuclear force
0-whatever KvP set.
Constant
Bremsstrahlung X-rays
Most xrays are brems
X-ray quantity is…
X-ray intensity
Measured in air Kerma (mR)
X-ray quality is measured in…
KvP
Penetrability of the X-ray beam
The monoenergetic equivalent of an X-ray beam
Effective beam
Section of metal added to the X-ray tube housing. Reduction in X-ray quantity; reduces patient exposure
Added filtration
Anode heat is …….
Excitation
Cascading
Inner electrons from each shell moves up.. X-rays are made with each placement
Target material is made of
Filtration is usually made of
Tungsten
Aluminum
Characteristic X-rays are made when
An outer shell fills an inner shell
K shell ionization
And tungsten have a discrete energy of 69kev
Kinetic energy of electrons gets converted to
Heat!
Discrete =
Characteristic
Low energy X-rays
Lower than 10kev
Change direction with no loss of energy
Coherent classical Thompson or Rayleigh
Affects the radiologist especially in flouro
Ionized atoms X-ray changes direction with a loss of energy
Outer shell electron interacts with moderate energy
No useful info on image
But greatly impacts image
Compton scattering
Higher levels of energy
Ionization with inner shell Ejection of K shell Causes damage to patient X-rays totally absorbed Lower levels of energy
Photoelectric effect
Secondary radiation is also called
Characteristic X-rays
Photoelectric cannot occurs unless incident X-rays has energy _______________ than the electron binding energy
= or greater
Absorbed by nucleus
10 mev
Nuclear fragments are emitted
Photodisintegration
Must be 1.02,mev
Specifically in regards to Nuclear Medicine
Energy divided equally
Electrons split and make a + and - electron
Pair production
Which interaction of matter is ALL or NOTHING absorption
Photoelectric
Compton scattering is_________ absorbed
Partially
2 tube interactions
Brems and characteristic
To decrease density on an image we would __________ mAs
Increase
If we increase KVP we must ________ mAs
15% rule
Decrease
Low energy interact with
Moderate energy interact with
High energy interact with
Atoms
Electrons
Nucleus
Energy potential in characteristic X-rays depends on the
Target material or Tungsten
Lower energy levels of radiation interact with
High energy levels
Bones, tissues
Pass through the body
Inherent filters are
Built into the tube housing and made of aluminum
Trough
Bow tie
Step wedge
Chest
CT
Don’t use
Monoenrgetic energy is
1 type of energy that removes low energy
Projectile electrons convert __________ to __________
Kinetic to heat
Filaments produce
Electrons
3 absorptions
Radiolucent- through the body
Radiopaque-absorbed in the bone
Attenuation -partially absorbed
Added filtration increases ——_
half value layer HVL
