REVISION LECTURES 1 -3

A wave packet of energy (photon) produced by electron-tungsten interactions in an X-ray tube's anode.

A particle of electromagnetic energy.

Energy that travels as waves of electric and magnetic fields.

Radiation with enough energy to remove electrons from atoms, such as X-rays, Gamma rays, and some UV radiation.

The number of wave cycles passing a specific point per second.

The distance between two corresponding points on a wave.

Energy emitted from an object, can be in the form of particles or waves.

A continuous disturbance in a medium that spreads from a source,carrying energy from one point to another.

The entire range of electromagnetic radiation, from radio waves to gamma rays.

X-rays produced by tungsten at high kVp (70kV or more); photons with specific energies.

Removes low-energy X-rays that don't contribute to images but increase patient dose. Aluminium filter.

Sets the energy level of X-rays; typically fixed between 60-70.

Controls the quantity of X-rays; mA (current) and time (exposure).

Higher energy X-rays, less contrast, better for soft tissue imaging, lowers dose.

More X-ray photons, higher dose. Too high is overexposure, too low is underexposure.

Distance between X-ray tube focal spot and patient affects the dose.

Reduces patient dose by limiting the X-ray beam to the area of interest.

If removed, a cylindrical image exposure will result.

Reduces dose, matching rectangular detectors shape.

An X-ray interaction where an inner-shell electron is ejected, completely absorbing the X-ray. This interaction creates contrast in the radiograph, and contributes to the dose.

An X-ray interaction with an outer-shell electron, where the X-ray is scattered in a different direction with reduced energy. This reduces image quality and contributes to the dose.

A rare interaction where X-rays directly ionize DNA and disrupt its structure.

A majority interaction where X-rays ionize water molecules, creating free radicals that damage DNA.

Radiation effects that occur 100% of the time above a certain dose (threshold).

Radiation effects that occur with a probability greater with increasing dose, but no safe dose of radiation.

A stochastic effect of radiation exposure, occurring with a probability that increases with dose.

The minimum dose required for a deterministic effect to occur.

X-rays are created when high-speed electrons interact with a tungsten target, either by decelerating (Bremsstrahlung) or by causing electron transitions (Characteristic).

X-rays produced when high-speed electrons are deflected by the nucleus, losing energy and emitting an X-ray.

X-rays produced when an incoming electron knocks an inner-shell electron out of the atom, causing an outer-shell electron to fill the gap, emitting characteristic X-rays.

The negatively charged electrode in the X-ray tube where electrons are generated from a heated filament (tungsten).

The positively charged electrode in the X-ray tube where electrons are stopped, producing X-rays and heat.

Increases the voltage from 240V to 60-70kV accelerating electrons in the X-ray tube

Maximum energy of Bremsstrahlung X-rays produced, determined by the maximum kinetic energy of the incident electrons.