4. X-Ray Image Formation

Compton

________ scattering depends on material density and its electron density.

Positron

________ and electron may interact and produce a pair of annihilation photons in the opposite direction, each with 511 keV.

N0

________ is the number of incident photons, N is the number of photons coming out of a material, and Δx is the distance the photons travel (objects thickness)

Electrons

________ within the matter oscillate in phase when the photon interacts, but none are ejected.

photoelectric effect

The ________ describes a photon interacting with a single electron, which bumps around energy levels.

Electron

________ is ejected and the photon loses energy, veering off of its path.

Rayleigh scattering

________ has a pretty low energy range, but this affects quality.

compton scattering

In ________, the photon interacts with a single (probably valence) electron.

linear attenuation coefficient

Μ is the ________.

Energy

________ must be greater than 1.02 MeV (double the static general photon ________, which is 511) to produce a positron- electron pair.

Photon interaction

________ depends on the materials density and atomic number, as well as the photons energy.

Compton

________ is the most common mode of interaaction within the imaging energy range.

Beers Law

N = N0 * e^-μΔx

Mass attenuation coefficient

μ / density

Photon interaction depends on the material’s (BLANK) and (BLANK), as well as the photon’s energy

Density, atomic number

Which two electron interaction modalities are most common in x-rays?

Compton scattering, photoelectric effect

Pair Production occurs when the photon interacts with the…

Nucleus

T or F: Electrons are ejected in rayleigh scattering

False

T or F: Electrons are ejected in compton scattering

True

Energy absorbance in the photoelectric effect produces what 3 things?

Photoelectron, ion, characteristic radiation

The photoelectric energy produced (increases/decreases) as atomic number increases, but (increases/decreases) as the indicent energy increases (aka electrons might pass through without being absorbed)

increases, decreases

This type of scattering is the main cause of noise on an x-ray image.

Rayleigh