Week 3 Flashcards
What are the consequences of x-ray interactions with human tissue?
X-ray interactions can lead to absorption, scattering, and potential biological damage.
Explain the Auger effect in x-ray interactions.
The Auger effect involves the emission of an electron from an atom after internal photoelectric absorption.
Define peak kilovoltage (kVp) and its influence on x-ray imaging.
kVp is the highest energy level of photons in the x-ray beam, controlling the beams penetrating power.
How does beam energy affect x-ray imaging?
Beam energy affects the penetration ability of x-rays. Higher energy increases penetration; lower energy leads to more absorption.
What are the different processes of x-ray interaction with matter?
Coherent scattering, photoelectric absorption, Compton scattering, pair production, and photodisintegration.
What is milliampere-seconds (mAs) and how does it control x-ray quantity?
mAs is the product of tube current (mA) and exposure time (seconds), controlling the total amount of radiation used.
How does attenuation affect an x-ray beam?
Attenuation is the reduction in intensity of the x-ray beam due to absorption and scattering.
What happens during pair production in x-ray interactions?
Pair production occurs when a high-energy photon converts into an electron-positron pair near a nucleus.
Why is absorption important for creating diagnostic images?
Absorption differences allow for contrast between various body structures, essential for diagnostic images.
How can a radiographer control patient dose during imaging?
By selecting appropriate exposure factors such as kVp and mAs to minimize patient dose while maintaining image quality.
What is photodisintegration and in what scenarios does it occur?
Photodisintegration involves a photon causing atomic nucleus disintegration, occurring at very high photon energies.
Describe direct transmission of x-ray photons in imaging.
Direct transmission occurs when photons pass through the patient without interacting and reach the image receptor.
What is the photoelectric interaction and its significance?
Photoelectric interaction involves photon absorption by an atom, resulting in electron ejection. Its significant for image contrast.
What is coherent scattering and when does it occur?
Coherent scattering involves low-energy photons scattering without energy loss, occurring typically under 10 KeV.
What is absorption in the context of x-ray interaction with matter?
Absorption is the transfer of photon energy to the atoms of the tissue, where the photon ceases to exist.
How can scatter radiation be minimized in x-ray imaging?
Using collimators and grids can reduce scatter radiation, minimizing fog and improving image quality.
What is the process of x-ray beam production?
A diagnostic x-ray beam is produced when high-speed electrons bombard a positively charged target in an x-ray tube.
What factors determine the probability of x-ray interaction with matter?
Factors include photon energy and the atomic composition of the material.
How do different materials affect x-ray beam attenuation?
Materials with higher atomic numbers have greater attenuation, influencing image contrast and quality.
How do primary, exit, and attenuated photons differ during an x-ray procedure?
Primary photons originate from the x-ray source, exit photons pass through the patient and reach the receptor, and attenuated photons are absorbed or scattered.