Ch.10 Flashcards
By definition X-rays are ____ waves with much higher energies than light and most other forms of electromagnetic radiation.
Electromagnetic
X-rays have energies in the tens of thousands of ____.
Volts
In order to generate energetic waves, electrons emitted from the X-ray tube filament must acquire extreme amounts of ____ energy by the time thy strike the anode disc?
Kinetic
What is the formula for the total kinetic energy that a moving object will be carrying?
KE= 1/2mv*2
M is the mass of the object
V is the velocity
Voltage is supplied to the X-ray machine by the ____ transformer.
Step up
Einstiens theory of relativity states that as a particle approaches the speed of light it gains____.
Mass
What three interactions can possibly take place in the anode with the projectile electron?
- Interact with an orbital electron
- Interact with just the atom
- Can be influenced by the nucleus
Most energy in the anode is dissipated as what?
Heat
If the electron passes near the atoms nucleus the positive attraction of the nucleus will cause it to ____ or slow down.
Brake
The deceleration in the speed of the electron represents a loss of ____ energy, that energy which is lost is emitted as an X-ray photon known as ______.
Kinetic
Bremsstrahlung radiation
Which type of radiation accounts for the vast majority of the overall X-ray beam?
Bremsstrahlung
The closer the electron approaches the nucleus, the greater the ____ of the electron due to the stronger pulling force of the nucleus.
Deceleration
The attractive force of the nucleus also causes the electron to ____ in its path of travel toward the nucleus.
Bend
The greater the deceleration of the electron, the more it deviates from its original direction and the more ____ energy is lost.
Kinetic
The closer the electron passes by the nucleus the ____ (higher, lower) will be the energy of the emitted X-ray.
Higher
_____ contributes to the differential absorption X-rays within the patients body by different tissues. It is this differential absorption that provides subject contrast to the remnant X-ray beam and makes the radiographic image possible.
Heterogeneity
Bremsstrahlung occurring at various distances from the nucleus produces a wide range of X-ray energies and is thus responsible for the heterogenous or ___-____ nature of the X-ray beam.
Poly-energetic
Because bremsstrahlung produces a whole range of X-rays at different energies, intermediate tissues such as bone marrow and fat pads can bed demonstrated because they absorb portions of the beam, stopping the lower energies and allowing the _____ energies to pass through.
Higher
Computers can modify the radiographic image in many ways but cannot what?
They cannot create information that was not present in the first place.
The full range of information from different tissues in the body must be represented within the _____ beam that reaches the detectors.
Remnant
The distance at which a projectile electron will pass by the atomic nucleus is a function of ______ probability.
Statistical
The volume of a sphere will increase by the _____ of the radius distance. So as the electron is further from the nucleus the volume of space increases.
Cube
To produce higher energy X-rays the electron must pass ____ to the nucleus.
Closer
Many more X-rays will be produced at ______ energies that at ____ energies.
Lower, higher
The maximum X-ray energy can never be more than the maximum energy of the projectile ______ striking the anode.
Electrons
The X-ray beam must pass through a number of materials which effectively act as _____.
Filters
What are the filters that the X-ray beam must travel through?
- The anode
- Glass window of the X-ray tube
- The surrounding oil
- A beryllium window filter
- A aluminum filter between the tube and collimation
- The collimation box
All of the filters absorb the X-rays with the _____ energies.
Lowest
The average kV within the beam is roughly _____ of the set peak kilovoltage.
1/3rd
When a projectile electron passes near an orbital electron it’s repulsive negative charge can ____ the orbital electron out of its orbit which then leaves a vacancy in that electron shell of the atom.
Eject
Once an orbital electron has been ejected the atom will pull in another electron to return to a _____ state.
Neutral
A vacancy in an atoms shell can be filled with another electron in a _____ shell.
Higher
What is the atoms ground state?
The state with the least energy
As the atom attempts to return to its ground state, electrons from outer orbits will fall down into vacancies that are ____ to the nucleus.
Closer
When an electron falls from an outer orbit down into an inner orbit there is a loss of ____ energy.
Potential
The potential energy lost from the electrons falling to inner orbit shells is converted into which type of energy?
Electromagnetic energy in the form of characteristic X-rays
_____ xrays depends entirely on the difference in energy levels between different orbital shells.
Characteristic
To predict the characteristic x-rays energies subtract the binding energy for the higher shell from that of the ____ shell.
Vacant
____ orbital electrons immediately fall back to their normal energy level by emitting electromagnetic waves in the form of light and infrared radiation.
Excited
_____ radiation is responsible for most of the heat generated in X-ray tube anodes.
Infrared
What two things must occur in order for characteristic xrays to be produced?
- The orbital electron must be in the path of the projectile electron.
- The projectile electron must have energy equal to or higher that the binding energy of the orbital electron.
What happens to the orbital electron if the projectile electron has too much energy?
The projectile electron will pass by it.
What happens to the orbital electron if the projectile electron does not have enough energy?
It will not be ejected.
Only __ characteristic xrays has influence on xray production.
K
What 5 factors can influence the xray beam spectrum?
- mAs
- kVp
- Target material
- Added filtration
- Generator type
The higher the atomic number of the a target material, then the more efficient it is and more ____ are produced.
Xrays
Atoms with higher atomic numbers improve the quality of the xray beam by emitting higher energies of both _____ and ____.
Bremsstrahlung and characteristic
If the amount of kinetic energy is greater then the energy of the xray emitted is what?
Also greater
Characteristic xrays from larger atoms also have higher energies because all of the _____ energies of the orbital shells are increased and there is a greater difference between the ____ energies of the shells.
Binding, binding
The ___ and ___ of characteristic xrays are affected more than bremsstrahlung by changes on target material because of the decreased or increased atomic number.
Quality and quantity
If you double the mAs then the number of xrays at every kV level is what?
Doubled fig 10-14
Doubling the mAs results in ____ as many xrays being produced.
Twice
Xray beam ___ is not at all effected by changes in mA, time, and mAs
Quantity
The minimum and average energy increases and shifts to the ___ but maximum energy does not with added ___ upon the xray beam spectrum.
Right, filtration FIG 10-15