Health Physics I: Unit 1 Review

Question 1

Results in a photoelectron and a characteristic photon

Answer 1

Photoelectric absorption

Question 2

Annihilation radiation

Answer 2

Positron emission tomography (PET)

Question 3

Radiation that is capable of creating electrically charged particles by removing orbital electrons from the atom of normal matter through which it passes

Answer 3

Ionizing radiation

Question 4

Does not imply radiation risk; it is simply a means for comparison; emphasizes that radiation is an innate part of our environment; provides an answer that is easy for the patient to comprehend

Answer 4

Background Equivalent Radiation Time (BERT)

Question 5

Agency that requires annual education of staff in dose reduction techniques; minimum qualifications for medical physicists; documentation of radiation doses; management of protocols to minimize radiation dose

Answer 5

The Joint Commission

Question 6

These measures take into consideration 1. both human and environmental physical determinants; 2. technical elements; and 3. procedural factors

Answer 6

Effective protective measures

Question 7

Optimization of radiographic exposure techniques that provide optimal radiation protection

Answer 7

As Low As Reasonably Achievable (ALARA)

Question 8

Radiation dose to which occupationally exposed persons could be continually exposed to without any apparent harmful acute effects

Answer 8

Tolerance dose

Question 9

A dose of radiation lower than which an individual has a negligible chance of sustaining biological damage

Answer 9

Threshold dose

Question 10

Radiation-induced cancer does not appear to have a dose level below which individuals would have no chance of developing this disease

Answer 10

True

Question 11

_________ can result in 1. creation of unstable atoms; 2. production of free electrons; 3. creation of highly reactive free radicals capable of producing substances poisonous to the cell; 4. creation of new biologic molecules detrimental to the living cell; 5. injury to the cell that may manifest itself as abnormal function or loss of function.

Answer 11

Ionization

Question 12

1 millisievert equals ________ sieverts.

Answer 12

1/1000

Question 13

Provides the basis for determining whether an imaging procedure or practice is justified

Answer 13

Diagnostic efficacy

Question 14

The cardinal principles of radiation protection include

Answer 14

Time, distance, shielding

Question 15

People are more willing to accept a risk if they perceive that the potential benefit to be obtained is:

Answer 15

greater than the risk involved

Question 16

In this approach, members assume responsibility for their areas of expertise and emphasize the importance of communication throughout the team.

Answer 16

Team approach to patient care

Question 17

Radiation quantity that is intended to be the best overall measure of the biologic effects of ionizing radiation

Answer 17

Effective dose

Question 18

Unit used to measure radiation exposure in the metric International System of Units

Answer 18

Coulomb per kilogram (cKg)

Question 19

This pledge includes the following: 1. Make the image gently message a priority in staff communications each year; 2. Review the protocol recommendations and, when necessary, implement adjustments to practice processes; 3. Communicate openly with parents

Answer 19

Image Gently

Question 20

This professional is expressly charged by the hospital administration with being directly responsible for the execution, enforcement, and maintenance of the ALARA program

Answer 20

Radiation Safety Officer (RSO)

Question 21

X-rays are a form of _________ radiation

Answer 21

ionizing

Question 22

This concept includes: 1. determining if an imaging procedure is justified; 2. obtaining images with minimal radiation exposure; 3. adhering to radiation safety guidelines

Answer 22

Diagnostic efficacy

Question 23

In the electromagnetic spectrum, higher frequencies are associated with:

Answer 23

Shorter wavelength, higher energy

Question 24

Which type of radiation remains fairly consistent year to year?

Answer 24

Natural radiation

Question 25

The most common unit of measure of equivalent dose.

Answer 25

Millisievert

Question 26

Ionizing radiation from natural sources grows larger because of accidental or deliberate human actions such as mining radioactive elements, the sources are termed:

Answer 26

enhanced natural resources

Question 27

_______ can enter a house through crawl spaces under living areas, floor drains and sump pumps, and porous cement block foundations

Answer 27

Radon

Question 28

Forms of electromagnetic radiation

Answer 28

X-rays, Gamma rays, Ultraviolet radiation

Question 29

Fallout from nuclear weapons tests and other environmental sources along with other man-made radiations contributes to approximately ______ to the equivalent dose of each person.

Answer 29

0.1 mSv

Question 30

T or F: Many excess cancer deaths have been predicted to occur in the 2 million people living within 50 miles of the 2 Mile Island nuclear reactor plant at the time of the accident

Answer 30

False

Question 31

Includes uranium-238, radium-226, and thorium-232 that are present in variable quantities in the crust of the earth

Answer 31

Terrestrial radiation

Question 32

The mass of an alpha particle is approximately ____ times the mass of a hydrogen atom and a positive charge twice that of an electron

Answer 32

four

Question 33

Electromagnetic radiation travels or propagates through space in the form of a wave but can interact with matter as a particle of energy called a photon

Answer 33

Wave-particle duality

Question 34

Considered by the EPA to be the second leading cause of lung cancer in the United States

Answer 34

Radon exposure

Question 35

The Environmental Protection Agency (EPA) recommends that action be taken to reduce elevated levels of radon in homes to a concentration less than:

Answer 35

4 pCi/L

Question 36

The total average annual radiation equivalent dose for estimated levels of radiation exposure for humans

Answer 36

2.0 mSv

Question 37

Helps shield the global population from exposure to essentially all high-energy, bombarding cosmic rays

Answer 37

Atmosphere, earth's magnetic field

Question 38

Cosmic radiation occurs in these two forms

Answer 38

Solar, Galactic

Question 39

The first decay product of radium

Answer 39

Radon

Question 40

Radiation included in atmospheric fallout from nuclear weapons testing and nuclear power plant accidents as a consequence of natural disasters

Answer 40

Man-made radiation

Question 41

The latent period for most radiation-induced cancers

Answer 41

15 plus years

Question 42

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

Answer 42

Characteristic photon or characteristic x-ray

Question 43

The number of x-rays emitted per inner-shell vacancy during the process of photoelectric absorption

Answer 43

Fluorescent yield

Question 44

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

Answer 44

1000 time smaller/less

Question 45

Coherent scattering is most likely to occur at less than _____ keV

Answer 45

10

Question 46

Interaction that results in the conversion of matter into energy

Answer 46

Annihilation reaction

Question 47

Another term for coherent scattering

Answer 47

Characteristic

Question 48

Interactions between x-ray photons with matter that involve a matter–antimatter annihilation reaction

Answer 48

Pair production

Question 49

Considered to be a form of antimatter

Answer 49

Positron

Question 50

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

Answer 50

X-ray photons

Question 51

Compton scattering is synonymous with:

Answer 51

incoherent scattering

Question 52

Atomic number of an atom

Answer 52

Z number

Question 53

Two interactions between x-radiation and matter that may result in the production of small-angle scatter

Answer 53

Coherent scattering and Compton scattering

Question 54

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 ___________ than the amount of energy that holds the electron in its orbit.

Answer 54

as large or larger

Question 55

An incident low-energy x-ray photon interacts with 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

Answer 55

Coherent scatter

Question 56

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

Answer 56

increases; increases

Question 57

By-products of photoelectric absorption

Answer 57

Photoelectron and characteristic photon

Question 58

Is not a type of interaction between x-radiation and biologic matter

Answer 58

Bremsstrahlung radiation

Question 59

Effective atomic number of compact bone

Answer 59

13.8

Question 60

X-ray photon energy required to initiate pair production

Answer 60

1.022 MeV

Question 61

Fluorescent radiation is also known as

Answer 61

characteristic radiation

Question 62

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?

Answer 62

Auger electron

Question 63

results in all-directional scatter

Answer 63

Compton interaction