Chapter 3: Interaction of X-Radiation with matter

Exit, or image formation, radiation is composed of which of the following?

noninteracting and small angle scattered photons

Which of the following contributes significantly to the exposure of the radiographer?

compton scattered photons

Which of the following defines attenuation?

absorption and scatter

In the radiographic kilovoltage range, which of the following structures undergoes the most photoelectric absorption?

compact bone

In which of the following x ray interactions with matter is the needy of the incident photon partially absorbed?

compton

When a high atomic number solution is either swallowed or injected into human tissue or structure to visualize it during an imaging procedure, which of the following occurs?

Photoelectric interaction becomes significantly enhanced, leading to an increase in the absorbed dose in the body tissues or structures that contain the contrast to medium

Which of the following characteristics primarily differentiates the probability of occurrence of the various interactions of x radiation with human tissue?

energy of the incoming photon

Which of the following influences attenuation?

1. Effective atomic number of the absorber

2. Mass density

3. Thickness of the absorber

1,2,3

A decrease in contrast of the image by adding an unwanted additional exposure results from which of the following interactions between x-radiation and matter?

1. Compton scattering

2. Pair production

3. Photoelectric absorption

1 only

The interactions of x ray photons with any atoms of biological matter are?

random, so the effects of such interactions cannot be predicted with certainty

Absorption

transference of electromagnetic energy from the x-rays to the atoms of the patients biological tissue

Permanent inherent filtration

combination of x-ray tube glass wall and the added aluminum placed within the collimator

Photoelectric absorption

interaction between x ray photon and any atoms inner-shell electron if an atom

Fluorescent yield

refers to the number of x rays emitted per inner shell vacancy

mAs

the product of electron tube current and the amount of time in seconds that the x-rays tube is activated

kVp

the highest energy level of photons in the x- ray beam, equal to the highest voltage established across the x -ray tube

Deuteron

proton-neutron combination

Compton scattering

interaction of an x-ray photon with a loosely bound outer shell electron of an atom

Effective atomic number (Zeff)

a composite Z value by weigh true or false or a material that is composed of multiple chemical elements

Aluminum

metal that hardens the x-ray beam by removing low energy components that would serve to only increase patient dose

Positron

positively charged electron

Radiographic fog

additional undesirable exposure on a completed radiographic image that can be caused by scattered radiation

Attenuation

any process decreasing the intensity of the primary photon beam directed toward a particular destination

Radiographic image receptor

a type of digital device that can convert the spatial pattern of the photons that emerge from the patient into electrical signal values that can be stored in computer and displayed as an image

Photoelectron

by product of photoelectric interaction

Tungsten and rhenium

metal alloys of which the anode of an x ray tube can be made

Pair production

interaction in which the energy of the incoming Fulton is transformed into two new particles, a negatron and a positron

Effective atomic number of compact bone

13.8

Annihilation radiation

radiation in the form of two oppositely moving 0.511- MeV photons generated as the result of mutual annihilation of matter and antimatter

Mathematic expression of Albert Einstein famous concept of mass energy equivalence

E=mc2

Effective atomic number of soft tissue

7.4

Absorbed dose

the amount of energy absorbed by the patient per unit mass

X ray photons

particles associated with electromagnetic radiation that have neither mass nor change and travel at the speed of light

Positive contrast media

agents that result in areas of increased brightness on a radiographic image

Exit, or image formation, photons

x ray photons that emerge from human tissue and strike the radiographic image receptor after passing through the patient being radiographed