MEDRAD QUIZ 4

Question 1

What types of properties does radiation has?

Answer 1

wave like and particle like

Question 2

What does the property like interactions of radiation depend on?

Answer 2

Depends on level of radiation - it might be more particle like or wave like (UV / xray / gamma rays – more particle like because they’re high E)

Question 3

Low energy interact with

Answer 3

Entire atom / molecule

Question 4

Medium energy (diagnostic x-ray) interact with

Answer 4

Electron

Question 5

Higher energy interact with

Answer 5

Nuclei (ignores electrons - goes for nucleus)

Question 6

Define attenuation

Answer 6

anything that reduces intensity of beam (reduction of radiation intensity)

Question 7

Scatter is a form of

Answer 7

attenuation (scatter decreases amount of energy photon has)

Question 8

2 types of interactions for x-rays

Answer 8

Absorption and compton scatter

Question 9

Photoelectric Effect also called

Answer 9

absorption

Question 10

Photons that hit patient and get completely absorbed they are undergoing what?

Answer 10

Photoelectric Effect

Question 11

Big difference between photoelectric effect and characteristic rad?

Answer 11

In photoelectric effect ALL the energy the photon has is given to electron (ALL energy is absorbed)

Question 12

Explain photoelectric effect interaction

Answer 12

Photon ionizes atom - k-shell electron ejected, all energy absorbed, outer shell electron drops in, secondary characteristic radiation occurs

Question 13

Energy of a photon formula

Answer 13

KE = hf - BE

Question 14

Secondary characteristic radiation is

Answer 14

K-characteristic that is low energy and is asborbed

Question 15

Probability of photoelectron effect occurring formula

Answer 15

𝑃𝐸 ∝ 𝑍^3/𝐸^3

Question 16

what happens if you increasing kVp regarding absorption?

Answer 16

decrease in absorption

Question 17

No chance of absorption happening when?

Answer 17

If E of photon is below BE

Question 18

Greatest probability of absorption happening

Answer 18

Photon E just above BE

Question 19

How do you see greater differences if you want to?

Answer 19

more absorption

Question 20

Photoelectric effect on patient

Answer 20

All energy of photon is absorbed by body (all energy to patient)

Question 21

What type of interaction is photoelectric effect?

Answer 21

High

Question 22

What does the photoelectric effect become?

Answer 22

secondary characteristic radiation

Question 23

Energy level of tissue characteristic rad? What would happen to it?

Answer 23

Low E, absorbed by patient

Question 24

Secondary characteristic radiation comes from?

Answer 24

human tissue

Question 25

Explain Coherent Scatter

Answer 25

All of the energy photon has is maintained when it scatters – doesn’t decrease in energy (the scatter photon energy will have the same energy as the photon that hit the atom)

Question 26

Coherent scatter interaction level

Answer 26

low energy (not enough to ionize - just excite)

Question 27

With coherent scatter, the scattered photon and the photon that hit the atom (incident x-ray) have the same what?

Answer 27

wavelength, frequency & energy

Question 28

Difference with coherent scatter?

Answer 28

Travels in a different direction

Question 29

Does coherent scatter happen often?

Answer 29

No, rare because it is low energy (less than 5% of interactions)

Question 30

Tissue damage regarding coherent scatter?

Answer 30

None of the energy is kept by the atom

Question 31

Does the photon lose energy with compton scatter?

Answer 31

yes

Question 32

Explain compton scatter

Answer 32

Interacts with patient and bounces off in another direction = low energy