Rad Tech 1: Unit 1 Exam Flashcards
Roentgen
- Discovered X-rays November 8th, 1895.
- Took the first X-ray of his wife’s hand on
December 22, 1895. - Cardboard painted with Barium Plantinocyanide would glow when the Cathode ray Tube (Crookes) was energized.
X-ray Characteristics
“Energy in Transit”, “Packets of Energy”, or “Energy disturbances”.
Travel at the speed of light (186,000 miles/sec) or they do not exist.
Can’t be slowed down, but can lose energy.
Illustrated as waveforms.
No mass or Electrical charge.
Cannot focus.
Can ionize matter.
Travels in straight lines.
Has characteristics of both waves and particles.
“X-Light”
X for “Unknown”
Cathode Ray Tube (Crookes)
Source of electrons
Glass tube with a filament inside.
Produces electrons when the filament gets heated.
Used to study electrons.
Original tubes were low energy and would take 20-30 mins., some up to 2 hours.
X-Ray Tube
How we produce x-rays.
Efficient X-ray Production
- Source of electrons (thermionic emission)
- Way to accelerate the electrons (kVp)
- Vacuum.
- Target
Vacuum Tube
Makes it to where no subatomic particles float in the tube.
* Subatomic particles can interfere/be obstacles in creating an efficient x-ray.
Cathode
Site of electron production.
Negatively charged side of the tube.
Thermionic Emission
Process of burning off electrons.
Gets very hot to burn off electrons, and they become free electrons.
(Source of electrons)
Anode
The Target
Struck by incident electrons (on their way over from the cathode to the anode)
Site of x-ray production.
Positively charged
Electrons travel from the cathode to the anode by _______.
Kinetic Energy
Kinetic Energy
Energy an object has while in motion
Kinetic energy from the electrons is turned into an x-ray once it hits the anode.
Energy cannot be created or destroyed, only ______
Changed.
Acute Radiodermatitus
Burns caused by radiation.
Thomas Edison
Created the Fluoroscope in 1898.
Stopped investigations when his assistant, Clarence Dally, died in 1904 due to amputations and Acute Radiodermatitus caused by radiation exposure.
Fluoroscopy vs X-ray
Fluoroscopy - Dynamic Imaging
X-ray - Static Imaging
Penatrability
Ability of the photon to go through a body part.
Controls Penatrability?
kVp
Coolidge Tube
Unveiled in 1913 - Step up from Crookes.
* Vacuum Tube* - Needed for efficient x-ray production. Provides a path for electrons to go from the Cathode to the Anode without bumping.
1st to have a filament - Allowed for x-ray intensity and energy to be selected with great accuracy.
Intensity = ?
Quantity
X-ray Beams are made of?
Energy type?
Heterogenous and Polyenergetic (x-rays vary in energy).
Made up of x-ray photons.
How is the quantity of photons described?
By the intensity of the beam.
Bigger parts require __________ x-rays?
More intense
kVp - Kilovolt Peak
Voltage!
Controls Quality
Voltage
How we accelerate electrons to the Anode
4 exchangable words to describe the photon’s kinetic energy (or their ability to enter and exit an object).
Energy
Frequency
Quality
Penetrability
Use the temperature of the filament to___?
Control the quantity of x-rays in the beam.
To control the penetrability of the x-ray____?
kVp (Voltage)
What controls quality of an x-ray?
kVp
To produce more x-rays, you need the filament to be _____?
Hotter.
Bigger mass requires ____ x-rays and ____?
More x-rays and Penetrability.
Hotter filament results in___?
More electrons burned off to send to the Anode.
When voltage is applied to the x-ray tube, the Cathode is ______ and the Anode is _____.
Cathode is negative and Anode is positive.
What kind of charge do electrons have?
Negative.
Electrons are attracted to _____ charge.
Positive charge (Anode)
Temperature controls _____.
Quantity
kVp controls ______.
Quality
kVp affects, but does not control, quantity when ______.
Voltage increased in the tube = Anode is more attractive.
Anode is more attractive = More electrons will travel over.
More voltage = ________
More electrons
Potential Difference
Voltage
Frequency and Wavelength are used to describe ____?
The energy of the x-ray machine.
Frequency
The amount of peaks in a waveform.
Wavelength
The distance between peaks in a waveform.
Amplitude
The height of peaks within a waveform.
Frequency up =
Wavelength down (low amplitude)
Frequency down =
Wavelength up (high amplitude)
kVp up =
Frequency up, Wavelength down.
kVp down =
Frequency down, Wavelength up.
kVp and frequency are ______ related?
Directly
When viewing x-rays, black is ____?
Transmission
When viewing x-rays, white is _____?
Absorption
When viewing x-rays, grey is _____?
Mixture of both (in between)
Density
How tightly atoms are packed into a space.
More atoms =
Harder, which means more density.
What does more density mean for x-ray absorption?
More likely for x-ray to absorb
Less Density =
Less likely for x-ray to absorb
X-ray photon
Bundle of energy
What happens to the energy of a photon when it is absorbed?
The energy transfers to the tissue in the body.
Ionization
The addition and subtraction of electrons from an atom.
Focusing Cup
Location of the two filaments.
Negatively charged.
Part of the Cathode.
EMR
Electromagnetic Radiation Spectrum
Radiowaves
Broadcasting music, MRI
Microwaves
Microwaves, Cell phones
Infrared Light
Communication between devices
Visible Light
Human eye can see
Colors we see are colors not absorbed
Black is absorption of all color
Ultraviolet Light
Tanning beds
X-rays
Medical imaging, Radiation therapy
Ionizes matter
Gamma Rays
Nuclear Medicine, Radiation therapy
Ionizes matter
Difference between Gamma Rays and X-rays?
The origin.
X-rays originate from outside the nucleus.
Gamma Rays originate from within the nucleus
When are X-rays acting as particles?
When they ionize matter and remove electrons from the body they are acting as particles.
When are x-rays acting as waves?
When they go through the electron because of high energy they are acting as waves.
When kVp is increased, what happens to the electrons?
They become more attracted to the Anode
mA is for___?
More x-rays. Does not make the beam more penetrating or have higher energy.
