MODULE 2 - X-Ray Production and Characteristics

Flashcards covering the key concepts of X-ray production, characteristics, and interactions.

X-rays (Part 1)

Invisible, electrically neutral, no mass, travel at the speed of light, cannot be optically focused, poly-energetic beam, isotropic creation.

X-rays (Part 2)

Produced across a range of energies, travel in straight lines, cause fluorescence, penetrate human tissue, can be absorbed or scattered, create secondary radiation, and can damage tissue.

Anode

The target area where X-rays are produced, often made of tungsten-rhenium.

Cathode

Produces electrons through thermionic emission from the filament.

Focusing cup

Directs electrons toward the anode target.

Thermionic emission

The release of electrons from a heated filament.

Rotor

Spins the anode to dissipate heat and improve X-ray production.

Glass port

Allows the X-ray beam to exit the tube.

Electromagnetic waves

Perpendicular electric and magnetic fields.

Electromagnetic radiation

A transverse wave with perpendicular field oscillations.

Wavelength (λ)

The distance over which a wave repeats.

Frequency (f)

The number of wave cycles per second.

Ionization

The process of gaining or losing an electron from an atom.

X-ray Charge and Mass

Massless and electrically neutral.

X-ray Production

Accelerated electrons from the cathode hit the anode target, releasing X-rays.

Bremsstrahlung radiation

X-rays produced when electrons slow down or change direction near the nucleus.

Characteristic radiation

X-rays emitted when an inner-shell electron is ejected and replaced, releasing a photon.

Photon energy for tungsten characteristic radiation

Around 69 keV.

Energy Converted to X-rays

Approximately 0.5%; the rest becomes heat.

kVp

Beam energy and penetration ability.

mAs

The quantity of radiation produced.

Added filtration

Removes low-energy X-rays and improves beam quality.

Photoelectric effect

Interaction with an inner-shell electron that results in total energy absorption and ionization.

Compton scattering

Interaction with an outer-shell electron, causing ionization and deflected photon emission.

Coherent scattering

Photon is deflected with no energy loss and no ionization occurs.

Secondary radiation

Radiation that results from X-ray interactions within the body.

Factors Affecting X-ray Emission Spectrum

kVp, target material, mAs, and type of filtration.

Poly-energetic

The X-ray beam consists of photons with a range of energies (heterogeneous beam).

Isotropic emission

X-rays are emitted in all directions from the point of creation.

Why X-rays can't be focused

They are a form of electromagnetic radiation that doesn't refract like visible light.

Travel in straight lines implication

They behave like rays, moving linearly unless absorbed or scattered.

Fluorescence

The ability of X-rays to cause certain materials to emit visible light.

Penetration ability of an X-ray beam

The kVp setting, beam energy, and filtration level.

Target material effect on X-ray production

Higher atomic number materials like tungsten produce higher quality and more efficient X-rays.

Purpose of added filtration

To remove low-energy, non-diagnostic photons and reduce patient dose.

Doubling mAs

It doubles the number of photons produced (beam quantity) without changing beam energy.

Function of the stator

It drives the rotor via electromagnetic induction, spinning the anode.

Electron interaction with the anode nucleus

Bremsstrahlung radiation is produced due to sudden deceleration or deflection of electrons.

Incoming electron ejects an inner-shell electron

Characteristic radiation is produced as an outer-shell electron fills the vacancy.

Two main types of radiation

Bremsstrahlung and characteristic radiation.

Why tungsten is used

Because of its high atomic number (74), high melting point, and efficiency in X-ray production.

Primary source of heat

Most energy (99.5%) from electron collisions is converted into heat rather than X-rays.

Controls the quantity of electrons

The mA (milliamperes) setting.

Controls the speed of electron acceleration

The kVp (kilovolt peak) setting.

Interaction resulting in total absorption

Photoelectric effect.

Interaction contributing to occupational exposure and scatter

Compton effect.

Scatter radiation significance

It degrades image quality and contributes to unnecessary radiation exposure.

Emission spectrum

The range and intensity of X-ray energies produced by the tube.

Inherent filtration

Filtration built into the X-ray tube components like glass envelope and oil.

Function of the collimator

It shapes and limits the X-ray beam to reduce patient exposure and improve image quality.

Increased kVp affect on image contrast

It decreases contrast by increasing the number of Compton interactions.