Deck 3: Interaction of X-Radiation With Matter

Question 1

During the process of coherent scattering,an incident low-energy x-ray photon interacts with

A)a single inner-shell electron,ejecting it from its orbit.
B)a single outer-shell electron,ejecting it from its orbit.
C)an atom and may transfer its energy by causing some or all of the electrons of the atom to momentarily vibrate and radiate energy in the form of electromagnetic waves.
D)a scattered photon of lesser energy,annihilating it.

Answer 1

an atom and may transfer its energy by causing some or all of the electrons of the atom to momentarily vibrate and radiate energy in the form of electromagnetic waves.

Question 2

What is the effective atomic number of compact bone?

A)5.9
B)7.4
C)7.6
D)13.8

Answer 2

13.8

Question 3

Particles associated with electromagnetic radiation that have neither mass nor electric charge are

A)ions.
B)negatrons.
C)positrons.
D)x-ray photons.

Answer 3

x-ray photons.

Question 4

Although coherent scattering is most likely to occur ____________,some of this unmodified scattering occurs throughout the diagnostic range and may result in small amounts of radiographic fog.

A)at less than 10 keV
B)between 30 keV and 60 keV
C)between 60 keV and 90 keV
D)above 100 keV

Question 5

The probability of occurrence of photoelectric absorption _________ as the energy of the incident photon decreases and the atomic number of the irradiated atoms _________.

A)increases markedly;decreases
B)decreases markedly;increases
C)increases markedly;increases
D)stays the same;increases

Question 6

Which of the following interactions between x-ray photons with matter involve a matter-antimatter annihilation reaction?

A)Compton scattering
B)Coherent scattering
C)Pair production
D)Photoelectric absorption

Question 7

Which of the following is not a type of interaction between x-radiation and biologic matter?

A)Compton scattering
B)Bremsstrahlung
C)Pair production
D)Photoelectric absorption

Question 8

The symbol Z indicates

A)atomic number of an atom.
B)atomic weight of an atom.
C)fluorescent yield.
D)the number of vacancies in an atomic shell.

Question 9

Annihilation radiation is used in which of the following modalities?

A)Computed tomography
B)Digital mammography
C)Positron emission tomography
D)Computed radiography

Question 10

Which of the following particles is considered to be a form of antimatter?

A)Electron
B)Positron
C)X-ray photon
D)Scattered x-ray photon

Question 11

Which of the following is not another term for coherent scattering?

A)Characteristic
B)Classical
C)Elastic
D)Unmodified

Question 12

Compton scattering is synonymous with

A)coherent scattering.
B)incoherent scattering.
C)photoelectric absorption.
D)photodisintegration.

Question 13

Which two interactions between x-radiation and matter may result in the production of small-angle scatter?

A)Photoelectric absorption and Compton scattering
B)Coherent scattering and Compton scattering
C)Photoelectric absorption and pair production
D)Coherent scattering and pair production

Question 14

Which of the following results in all-directional scatter?

A)Classical interaction
B)Coherent interaction
C)Photoelectric interaction
D)Compton interaction

Question 15

What is the term for the number of x-rays emitted per inner-shell vacancy during the process of photoelectric absorption?

A)Characteristic absorption
B)Classical gain
C)Fluorescent yield
D)Modified pair production

Question 16

In photoelectric absorption to dislodge an inner-shell electron from its atomic orbit,the incoming x-ray photon must be able to transfer a quantity of energy

A)less than the energy that holds the atom together.
B)10 times as great as the energy that holds the atom together.
C)as large as or larger than the amount of energy that holds the electron in its orbit.
D)equal to or greater than 1.022 MeV,regardless of the energy that holds the electron in its orbit.

Question 17

Which of the following interactions results in the conversion of matter into energy?

A)Classical scattering
B)Photoelectric absorption
C)Modified scattering
D)Annihilation reaction

Question 18

Which of the following terms refers to the radiation that occurs when an electron spontaneously drops down from an outer shell of an ionized atom to fill a vacancy in an inner shell of that atom?

A)Characteristic photon,or characteristic x-ray
B)Bremsstrahlung
C)Photoelectric radiation
D)Primary radiation

Question 19

Fluorescent radiation is also known as

A)characteristic radiation.
B)coherent scattering.
C)Compton scattering.
D)unmodified scattering.

Question 20

Which of the following are by-products of photoelectric absorption?

A)Photoelectron and Compton-scattered electron
B)Low-energy scattered x-ray photon and characteristic photon
C)Low-energy scattered x-ray photon and Compton-scattered electron
D)Photoelectron and characteristic photon

Question 21

When an inner electron is removed from an atom in a photoelectric interaction,thus causing an inner-shell vacancy,the energy liberated when this vacancy is filled can be transferred to another electron of the atom,thereby ejecting that electron,instead of emerging from the atom as characteristic radiation.What is this electron called?

A)Auger electron
B)Compton electron
C)Edison electron
D)Sievert electron

Question 22

The x-ray photon energy required to initiate pair production is

A)0.511 keV.
B)1.022 keV.
C)0.511 MeV.
D)1.022 MeV.

Question 23

Since the density of air is approximately _________________ than that of soft tissue,a given volume of air will interact with far fewer x-ray photons than adjacent regions of soft tissue,thereby permitting more radiation to reach the image receptor.

A)1000 times smaller
B)1000 times larger
C)100 times smaller
D)100 times lager

Question 24

If two anatomic structures have the same density and atomic number but one is twice as thick as the other,the thicker structure will absorb

A)the same number of x-ray photons.
B)twice as many x-ray photons.
C)four times the number of x-ray photons.
D)eight times the number of x-ray photons.

Question 25

X-rays are carriers of

A)disease.
B)electrons.
C)fluorescent properties that make them visible.
D)manmade electromagnetic energy.