Photon Interactions

Question 1

Name the interaction in which the x-ray photon does not transfer energy, does not ionize atoms, and does not deliver a dose of radation to the patient

Answer 1

Coherent Scatter

Question 2

It is more likely to have compton’s scatter or PE occurring?

Answer 2

Compton’s Scatter

Question 3

Name the photon Interacting that interacts with the nucleus causing 2 different particles

Answer 3

Pair Production

Question 4

Name the interaction that involves the incident photon being absorbed breifly and then released in a different direction, but with no loss of energy

Answer 4

Coherent Scatter

Question 5

Process that prevents photons from reaching a pre-defined destination is known as what?

Answer 5

Attenuation

Question 6

Different types of matter absorb x-rays differently. Some absorb more; some absore less. The term usewd to describe this is?

Answer 6

Differential absorption

Question 7

What is not present when comparing the PE formula to the compton’s formula?

Answer 7

Atomic number of matter

Question 8

With reference to the image, why is it necessary to have PE interactions?

Answer 8

PE gives contrast to the image

Question 9

When the energy of the photon increases the overall net interaction apparent on an image is?

Answer 9

compton’s scatter

Question 10

Name the photon interaction resulting from low kVp energies, is not useful in diagnostic imaging, but is useful in mammography.

Answer 10

Coherent Scatter

Question 11

Name the photon interaction used for the industry proposes

Answer 11

photodisintegration

Question 12

In the PE what happens to the energy of the incident photon?

Answer 12

part overcomes binding K shell energy and part goes to eject electrom

Question 13

X-ray photons leave the tube may undego 3 types of interaction. Name them

Answer 13

Absorbed, scattered or transmitted

Question 14

In compton’s scatter, the ejected outer shell electrom is know as?

Answer 14

Compton’s electron or secondary electron

Question 15

What determines which of the 5 interactions will occure when the x-ray photon interacts with the patient’s atoms

Answer 15

energy of the photon

Question 16

Does bone or soft tissue have a higher physical density?

Answer 16

Bone (2x density of soft tissue

Question 17

The difference between the number of photons in the primary beam and the number of photons that attenuated is know as

Answer 17

Remnant Radiation

Question 18

Name the interaction which results in complete absorption of the incident photon

Answer 18

Photoelectric Effect

Question 19

On an image, absorbed photons appear as?

Answer 19

White or light areas

Question 20

Does complete absorption result in harmful effect to patient?

Answer 20

Yes. Absorption of energy=ionization occurred=patient dose of radiation

Question 21

In compton’s scatter, where does the energy of the incident photon go?

Answer 21

1) overcomming binding energy
2) Compton’s photon
3) Compton’s electron

Question 22

What must the energy of the incident photon be so pair production occurs?

Answer 22

1.02 MeV or 1022 KeV

Question 23

According to the formula, the probability of PE occurring increases when what increases?

Answer 23

Atomic number of matter & physical density

Question 24

In pair production, does the resulting particles have the same energy and charge

Answer 24

same energy, but one is negative and one is positive charged

Question 25

The final x-ray beam is made of of what?

Answer 25

Transmitted and scattered photons

Question 26

Can a grid clean up 100% of unwanted scatter radiation before is reaches the image receptor?

Answer 26

No!

Question 27

Which interaction is the most important for radiographic contrast?

Answer 27

Photoelectric Effect

Question 28

This photon interaction involves the absorption of the incident photon by the nucleus resulting in the nuclear fragment or nucleon.

Answer 28

Photodisintergration

Question 29

Radiation interacting with the atoms of the patient can lead to?

Answer 29

Disruption of chemical bonds; function of organism may be harmed

Question 30

If kVP is increased by 15% and mAs is halved, is there a change in density?

Answer 30

No!

Question 31

When the energy of the photon decreasesoccurs, what happens to the amount of compton’s scatter? What happens to PE?

Answer 31

Both Increases

Question 32

During the PE, outer shell electrons fill the inner shells releasing the extra energy as what?

Answer 32

Characterstic photons

Question 33

The international units used to describe radiation amounts are:

Answer 33

Coulombs per kilogram, gray and the sievert

Question 34

In compton’s scatter, does the incident photon cease to exist?

Answer 34

No, now scattered photon with less energy and different angle.

Question 35

Why does compton’s scatter use less energy than PE?

Answer 35

Less energy needed to overcome binding energy of outer shell electron

Question 36

What interaction results when the incident photon strikes the inner shell electron and then ceases to exist

Answer 36

Photoelectric Effect

Question 37

Does the probability of compton’s scatter occurring increase or decrease when photon energy increases

Answer 37

Decreases slightly

Question 38

The effects of ionization of the human body depends on what?

Answer 38

Amount of energy deposited and probability that vital molecules are affected

Question 39

What photon interaction does this formula depict? (z3/e3)rho

Answer 39

PE

Question 40

Name the tradition units used to measure radiation

Answer 40

Roentgen, rad, and rem

Question 41

What photon interaction takes place when a incident photon interacts with an outer shell electron

Answer 41

Compton’s Scatter

Question 42

Pair production interaction is important in two areas or radiology. Name them

Answer 42

Radiation Therapy and Positron emission tomography (PET)

Question 43

Does boen or soft tissue have a higher atomic number?

Answer 43

Bone (about 2 times)

Question 44

Name the interaction in which a photo electron results when an inner shell electron is ejected out of it’s shell

Answer 44

PE

Question 45

Name the photon interaction that occurs at energies about 10 MeV

Answer 45

Photodisintegration

Question 46

According to the formula, the probability of PE occuring decreases drastically with an increae in?

Answer 46

photon energy