X-Ray Production Flashcards
the medical discipline that uses medical imaging to diagnose and treat diseases
radiology
the specialty of dentistry and discipline of radiology concerned with the production and interpretation of radiographic images, including CT and MRI scans that are used for the diagnosis and management of diseases, disorders and conditions of the mouth, face and jaws
oral radiology
smallest particle of an element having the chemical
properties of the element
atom
transmission of energy through space and matter in the form of
waves or particles
radiation
high-energy radiation, capable of producing ions
enough energy to overcome the electron binding energy
ionizing radiation
spontaneous nuclear disintegration process of a molecule to
acquire a more stable form
radioactivity
What radiation is this?
Tiny particles of matter
They have mass
They travel in a straight line at high speed, < speed of light
They are electrically charged, except for the neutrons
Particulate radiation
What radiation is this?
Wave energy propagation
No mass
It is generated when the velocity of an electrically charged particle is altered
Only higher-energy cause ionization (X-rays, Ultraviolet rays, γ rays …)
Electromagnetic radiation
What are the two theories can describe the properties of electromagnetic radiation
Quantum theory
Wave theory
Which theory is this?
Small discrete bundles of energy (PHOTONS)
Travels at the speed of light
Contains a specific amount of energy (electron volt - eV)
Quantum theory
Which theory is this?
Electric and magnetic field
Travel at the speed of light in a vacuum
Are described in terms of their wavelength and frequency
Wave theory
What does the following create:
when the velocity of an electrically charged particle changes
in oral radiology we alter the velocity of e-
x-rays
Recipe for x-rays:
Get some e-
Change the velocity of them (accelerate then decelerate)
Cathode: - or + ?
-
Anode: - or + ?
+
source of electrons
Tungsten filament
Concave molybdenium bowl is the ________ cup
focusing
Concave molybdenium bowl and tungsten filament are part of what in the x-ray tube
cathode (-)
focal spot
tungsten
thermal conductor
copper block
tungsten and a copper block are part of what of the x-ray tube
Anode (+)
made of lead glass and window of non-lead glass
evacuated glass envelope
Energy used to produce x-rays
electricity
flow of electrons flowing through a conductor
Electric Current
path through which an electric current goes into the machine
circuits
responsible for increasing or decreasing the voltage electric current
Transformers
What is the current in the tungsten filament
3 to 10V
Heating the filament is ________ emission
thermionic
Upon reaching tungsten target:
kinetic energy goes to what % of x-rays and what % of heat
x-rays: 1%
heat: 99%
controls the electrical current / number of electrons moving within the filament
Amperage/milliamperage (mA)
Maximum voltage that enables the movement of electrons from the cathode to the anode
Kilovoltage (kV) / kilovolt peak (kVp)
x-ray production inside the x-ray tube has collisions with what 2 things
heat generation and x-rays production
Incident electron deflected by the electrons of the outer shells
Electron collides with an electron of the outer shells
Collisions with heat generation
Bremsstrahlung (German)
▪ ~70% of x-rays produced
▪ No collision with other electrons
▪ Broad spectrum of energy
▪ Keeps colliding with other atoms
Collisions with x-rays production –> Braking radiation
Electron hits the nucleus of an atom
All the kinetic energy is converted into a high-energy x-ray photon
Rare!!!
Collisions with x-rays production –> Braking radiation
Displacement of an electron of the inner shells
Lesser amount of x-ray photons
Requires energy greater than 70 kVp
Electrons change of positions
between the orbitals
Collisions with x-rays production –> Characteristic radiation
X-ray beam (photons) produced in the anode, leaving the x-ray tube
Primary radiation
What kind of radiation?
Radiation produced by photons interacting with matter
Secondary radiation
What kind of radiation?
Deflected in all directions after interacting with the matter
Scattering of radiation
No interaction
complete absorption/photoelectric absorption
Compton scattering of the photons
coherent scattering of the photons
X-ray interactions (OUTSIDE THE X-RAY TUBE)
The x-ray photon passes through the patient unchanged and leaves the atom unchanged
These are responsible for producing densities and make dental radiography possible
No interaction
X-ray photon hits an electron of any orbital
The photon is completely absorbed
There is atom ionization due to an ejected photoelectron
Absorption of energy/ Photoelectric effect
Scattering with ionization
Photon loses some of its energy, is deflected, and continues with less energy
Ejected electron = Compton Electron
Compton scattering
What kind of scattering?
Photon interacts with a whole atom
The atom becomes momentarily excited
and generates another photon with the same energy
No changes to the atom at the end
Coherent Scattering
