Radiation Physics & Principles Flashcards

What is the primary purpose of added filtration in an x-ray tube assembly?

Answer: Remove low-energy photons that contribute only to patient dose

Added filtration removes low-energy (soft) x-rays that would be absorbed by the patient without contributing to image formation.

Half-value layer (HVL) is used to describe which characteristic of an x-ray beam?

Answer: Beam quality (penetrating ability)

HVL is the thickness of a specified material that reduces beam intensity by half, describing the beam's penetrating quality.

Compton scatter is most likely to occur when x-ray photons interact with which type of electrons?

Answer: Outer-shell (valence) electrons

Compton scatter involves interaction between x-ray photons and loosely bound outer-shell electrons, producing a scattered photon and a recoil electron.

Which factor has the greatest influence on the quantity (number of photons) of x-rays produced?

Answer: mAs

mAs (milliampere-seconds) directly controls the number of x-ray photons produced and thus beam quantity.

What is the primary composition of the x-ray beam produced at the anode?

Answer: Mostly bremsstrahlung radiation

Bremsstrahlung (braking) radiation makes up approximately 80–90% of the useful x-ray beam at diagnostic energies.

Which of the following describes the line-focus principle in x-ray tube design?

Answer: Angling the anode target to create a smaller effective focal spot

The line-focus principle uses an angled anode target so the effective (projected) focal spot is smaller than the actual focal spot, improving image sharpness.