FREE RADIOLOGY AND STUDY GAMES ABOUT X-RAY

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FREE RADIOLOGY AND STUDY GAMES ABOUT X-RAY

INTERACTION EXAM QUESTIONS

Actual Qs and Ans Expert-Verified Explanation

This Exam contains:

-Guarantee passing score -65 Questions and Answers -format set of multiple-choice -Expert-Verified Explanation Question 1: At kVp greater than 70, ______ is characeristic and ______ is brems.

Answer:

10-20%, 80-90%

Question 2: is atom ionized in Coherent interaction ? Is any energy transferred?

Answer:

no to both

Question 3: Gray (rad)

Answer:

radiation absorbed dose; patient dose

Question 4: rem

Answer:

radiation equivalent man

Question 5: Describe the interaction of characteristic.

Answer:

Incident electron has enough energy to interact with inner shell electron.Innershell e- is knocked out and becomes a free e-.Outer shell e- cascades to fill the innershell e- to make stable.Lost energy is characteristic

Question 6: Name types of particulate radiation (particles) can ionize matter

Answer:

• alpha particles
• beta particles
• electrons
• protons

-neutrons

• heavy nuclei

Question 7: three things that may occur with x-rays?

Answer:

1) it can pass through unaffected (transmitted)

2) it can change direction and loose energy (scattered)

3) it can be attenuated (absorbed)

Question 8: Beta particles

Answer:

• identical to electrons

-come from the nucleus of radioactive material -negatively charged

• have less energy than alpha particles

Question 9: Does Coherent scatter affect diagnostic imaging? why? when can it be a problem?

Answer:

no. this occurs at such a low energy- most of the scatter does not hit the film.it can be a problem in mammography

Question 10: Describe relationships between keV and PE and scatter?

Answer:

• the higher the kVp, the less the percentage of photoelectric and the greater the percentage of

Compton scattering

• the lower the kVp, the more of the photons are absorbed (photoelectric) and the less are scattered

(Compton)

Question 11: what is the energy state of an electron?

Answer:

Electrons that are further away from the nucleus have a higher total energy* than those close to the nucleus They are in a "higher energy state" When an outer shell electron drops into an inner shell, its total energy decreases

Question 12: what is the binding energy of an electron?

Answer:

it is the amount of energy required to remove the electron from its orbit

*An atom has a positively charged nucleus surrounded by orbital electrons that have negative charges.These electrons are held in place by their binding energy

Question 13: What is the technical factor that affecs attenuation?

Answer:

kVp Question 14: In Classical scattering interaction the INCIDENT XRAYS interact with the target atom. This causes what to occur?

Answer:

he atom becomes excited and releases energy as a scattered xray with the same amount of energy as the incident xray.

Question 15: When is the Photoelectric effect likely to occur?

Answer:

when the incident x-ray has just slightly more energy than the electron

Question 16: what are the most common interactions within the diagnostic range of x-rays?

Answer:

Interactions with orbital electrons

Question 17: What effect does compton have on an image?

Answer:

Decreases contrast, produce fog, no useful information

Question 18: why is the secondary radiation of PE a low energy radiation?

Answer:

because of the low atomic number of most atoms in the body (hydrogen, oxygen, carbon) =>these x-rays are usually very low energy and in a different direction than the incident photon

Question 19: What will happen to positron?

Answer:

The positron will interact with an electron and will undergo the "annihilation reaction" which will turn matter into energy

Question 20: Where is the pair production interaction used?

Answer:

PET scan and rad. therapy Question 21: how to calculate the kinetic energy of photoelectron in photel. effect interaction?

Answer:

kinetic energy that is equal to the difference between the incident x-ray energy and the electron binding energy Ei = Eb + Eke

• Ei = energy of the incident photon
• Eb = binding energy of the electron
• Eke = kinetic energy of the photoelectron

Question 22: PE and atomic number?

Answer:

• the probability of a photoelectric interaction increases dramatically as the atomic number increases
• photoelectric effect = (atomic number)3