Review Questions Flashcards by Lexi Zanolini

According to NCRP Report #160, natural background radiation represents what percentage of humans?
1. 21%
2. 50%
3. 82%
4. 5%

82%

Most comes from radon Gas

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According to NCRP Report #160, the greatest source of natural background radiation exposure is what?

Radon gas

Radon gas accounts for 50% of human’s total expsure

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Cosmic Radiation:
1. Is present only in space
2. Is a source of exposure only to persons who lie in the sun
3. Is of concern only to space travelers
4. Is greater at higher altitudes because of a thinner atmospheric shield

Is greater at higher altitudes because of a thinner atmospheric shield

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Radon Gas:
1. Presents a danger when undetected
2. 2. Is present in doses proportional to other sources
3. Is entirely human-made
4. Is the source of 100% of annual background dose

Presents a danger when undetected

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X-ray and gamma rays used in diagnostic imaging are:
1. Not of concern because the beam is filtered
2. Part of the natural background dose
3. Part of an artificial background radiation dose
4. An insignificant dose to the general population because they are used safely

Part of an artificial background radiation dose

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A Personnel monitoring device that is accurate to 1 mrem is the:
1. Thermoluminescent dosimeter
2. Film badge
3. Optically stimulated luminescence dosimeter
4. Pocket ionazation chamber

Optically stimulated luminescence dosimeter

TLDs - 5 mrem
Film Badge - 10 mrem

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The greatest exposure of human-produced radiation exposure is?
1. Radon gas
2. Medical x-rays and gamma ray imaging procedures
3. MRI scans
4. Sonograms

Medical x-rays and gamma ray imaging procedures

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Which of the following is not part of background radiation?
1. Dental rays
2. Microwave ovens
3. Radon Gas
4. Weapons testing

Microwave ovens

Microvaves do not emit ionizaing radiation

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Which of the following occurs at greater than 1.02 million electron volts?
1. Photoelectic interaction
2. Comptom interaction
3. Classic scatter
4. Pair production

Pair Production

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Which of the following is also known as “coherent scattering”?
1. Photoelectric interaction
2. Compton Interaction
3. Classic Scatter
4. Pair production

Classic Scattering

This form of scatter has no effect on the image below 70 kVp

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Which of the folowing photon-tissue interactions does not occure in diagnostic imaging?
1. Photoelectric Interaction
2. Compton interaction
3. Coherent scatter
4. Pair production

Pair Production

Only occurs above 1.02 million elctron volts

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Which of the following is responsible for producting contrast on the radiograph?
1. Photoelectric Interaction
2. Compton interaction
3. Coherent scatter
4. Pair production

Photoelectric interaction

Coherent scatter produces fog which affects it but doesn’t produce it

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Which of the following produces scatter radiation that exits the pt & may fog the radiograph?
1. Photoelectric Interaction
2. Compton interaction
3. Coherent scatter
4. Pair production

Coherent Scatter

Scatter thats not absorbed by a grid may strike the IR & reduce contrast

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Which of the following produces scatter as a result of vibration of orbital electrons?
1. Photoelectric Interaction
2. Compton interaction
3. Coherent scatter
4. Pair production

Coherent scatter

AKA classical or Thompson scattering

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Which of the following results in total absorption of an incident x-ray photon?
1. Photoelectric Interaction
2. Compton interaction
3. Coherent scatter
4. Pair production

Photoelectric interaction

Complete depletion of energy results in contrast on image.

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Which of the following is the only photo-tissue interaction that does not result in ionization?
1. Photoelectric Interaction
2. Compton interaction
3. Coherent scatter
4. Pair production

Coherent scatter

No electrons are removed from the atom being struck

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Which of the following involves interaction between an incident photon & an atomic nucleus?
1. Photoelectric Interaction
2. Compton interaction
3. Coherent scatter
4. Pair production

Pair Production

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Which of the following photo-tissue interactions primarily involves K-shell electrons?
1. Photoelectric Interaction
2. Compton interaction
3. Coherent scatter
4. Pair production

Photoelectric interaction

Occurs as incident photons deposit their energy into the K-shell

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Which of the following primarily involves loosley bound outer-shell electrons?
1. Photoelectric Interaction
2. Compton interaction
3. Coherent scatter
4. Pair production

Compton interaction

Both electron and photon scatter; atom becomes ionized

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Which of the following results in the production of a photoelectron that is ejected from the atom?
1. Photoelectric Interaction
2. Compton interaction
3. Coherent scatter
4. Pair production

Photoelectron interatcion

Inner-shell is ejected becoming a photoelectron; atom is now ionized

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Which of the following photo-tissue interaction necessutates the use of a grid?
1. Photoelectric Interaction
2. Compton interaction
3. Coherent scatter
4. Pair production

Compton interaction

Produces scatter, Grid is used to absorb it before it hits the IR

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What is the traditional unit of measurment that equals 100 ergs of energy deposited per grams of tissue?

RAD - Radiation absorbed dose

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Which of the following may result in occupational exposure for a radiographer?
1. Photoelectric Interaction
2. Compton interaction
3. Coherent scatter
4. Pair production

Compton interaction

“if your in compton, you better scatter”

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What is the traditional unit of measurement that is derived from multiplying rad by a radiation weighting factor?

Rem

Equivalent dose - accounts for bio effects w/ different radiation

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What unit would be used to describe the radiation presnt in a fluoroscopic room?

Roentgen | Roentgen(trad.)/ Coulombs per kilogram (SI) - Unit of in-air exposure

The amount of energy deposited by radiation per unit length of tssue being traversed is?

LET | Determined the use of Wr when the equivalent dose is calculated

What agency publishes radiation protection standards based on scientific research?

National Council on Radiation Protection and Measurment (NRCP)

The agency that enforces radiation protection standards relating to radioactive matererial at the federal level is?

Nuclear Regulatory Commission (NRC)

Effective dose limit is defined as the upper boundary dose that?

Can be absorbed, either in a single exposure or annually, with a negligible risk of somatic or genetic damage to the individual.

ALARA is an acronym for?

As Low As Reasonably Acheivable

Graphs called that show the relationship between dose of radiation received and incidnence of effects?

Dose-response curves

Which of the following is the basis for all radiation protection standards? 1. Nonlinear-nonthreshold effect 2. Linear-nonthreshold effect 3. Linear-threshold effect 4. Nonlinear- threshold effect

Linear-nonthreshold effect | Every dose creates a response

Which of the following means there is no safe level of radiation, & the response to radiation is not proportional to the dose received? 1. Nonlinear-nonthreshold effect 2. Linear-nonthreshold effect 3. Linear-threshold effect 4. Nonlinear- threshold effect

Nonlinear-nonthreshold

Which of the following means there is no safe level of radiation, & the response to the radiation is directly proportional to the dose? 1. Nonlinear-nonthreshold effect 2. Linear-nonthreshold effect 3. Linear-threshold effect 4. Nonlinear- threshold effect

Linear-nonthreshold effect

Which of the following means there is a safe level of radiation for certain effects, & those effects are directly proportional to the dose received when the safe level is exceeded? 1. Nonlinear-nonthreshold effect 2. Linear-nonthreshold effect 3. Linear-threshold effect 4. Nonlinear- threshold effect

Linear-threshold

Which of the following means there is a safe level of radiation for certain effects , & those effects are not directly proportional to the dose received when the safe level is exceeded? 1. Nonlinear-nonthreshold effect 2. Linear-nonthreshold effect 3. Linear-threshold effect 4. Nonlinear- threshold effect

Nonlinear-threshold effect

Effects of radiation that occurs randomly, with the probability of such effects being proprotional to the dose received, are called?

Probabilistic effects | Increased dose = increase probability of effects; doesnt effect severity

Effects of radiation that become more severe at higher levels of exposure once the threshold dose is exceeded are called?

Deterministic effects

What is the embryo or fetus equivalent dose limit per month?

0.05 rem | 0.5 rem is dose for total gestation

Occupational cumulative exposure = age in years x what dose?

1 Rem

What is the annual effective doseThe annual occupational effective dose limit for stochastic effects is?

5 Rem | Dose of Radiographers annual exposure limit

What is the annual effective dose limit for radiography students younger than 18?

0.1 rem | Students over 18 = 5 rem

What is the annual effective dose limit for the general public, assuming infrequent exposure?

0.5 rem | 500 mrem is 1/10th occupational dose

What is the embryo or fetus equivalent dose limit for gestation?

0.5 rem | Same as general population w/ infrequent exposure

What is the annual effective dose limit for the general public, assuming frequent exposure?

0.1 rem | 100 mrem. The dose for gen public for infrequent exposure is 500 mrem.

What is the annual effective dose limit for the general public for the lens of the eye?

0.05 rem

The Wr used in calculating rem takes into account which of the following: 1. Meiosis 2. Age 3. LET 4. Pregnancy

LET

LET & biological damages are: 1. Directly proportional 2. Indirectly proportional 3. Inversely proportional 4. Unrelated

Directly proportional

The ability of different types of radiation to produce the same biologic response in an organsim is called?

Relative biological effectivness (RBE)

The phases of the cellular life cycle, in order is?

Interphase (G1, S, G2), prophase, metaphase, anaphase, telophase

The process of cell division for germ cells is called?

Meiosis | Mitosis is cell division for somatic cells

Which of the following occurs when radiation transfers its energy to DNA? 1. Indirect effect 2. Target theory 3. Direct effect 3. Mutations

Direct effect | DNA in the cell's nuclous has been directly struck by the photons

____ states that each cell has a master molecule that directs all cellular activities & that, if inactivated, results in cellular death.

Target theory | Master molecule is the DNA.

What describes the amount of radiation required to increase the number of mutations in a population by a factor of 2?

Doubling dose | Doubling dose in humans ranges from 50-250 rads

What occurs when radiation tranfers its energy to the cellular cytoplam?

Indirect effect

Which of the following induces radiolysis? 1. Indirect effect 2. Target theory 3. Direct effect 4. Doubling dose

Indirect effect | Radiolysis creates Hydrogen Peroxide in cytoplasm (poison)

What is the name for changes in genetic code passed on to the next generation?

Mutations

What is responsible for production of free radicals?

Indirect effect

What occurs when the master molecule is struck by radiation? 1. Indirect effect 2. Target theory 3. Direct effect 4. Doubling dose

Direct effect

What poisons the cell with H2O2? 1. Indirect effect 2. Target theory 3. Direct effect 4. Doubling dose

Indirect effect | Radiolysis

Most of the damage to a cell occurs as a result of?

Indirect effect | Cells are most sensitive when immature, undifferential, or dividing

Cell radiosensitive is decribed as what?

Law of Bergonie & Tribondeau

The law that states that cells are most sensitive to radiation when they are nonspecialized & rapidly dividing is?

The Law of Bergonie & Tribondeau

Oxygen Cells are more radiosensitive when? 1. Fully oxygenated 2. Deoxygenated 3. Slowly dividing 4. Near the skin

Fully oxygenated | Oxygen enhancement ratio (OER)

Blood count can be depressed with a whole-body dose of? 1. 25 rem 2. 25 mrem 3. 1 rem 4. 10 rem

25 rem

The most radiosensitive cells in the body are?

Epithelial cells

Cells that are least sensitive to radiation exposure?

Nerve and muscle cells

Compared with younger and older women, ova in women of reproductive age are? 1. More radiosensitive 2. Less radiosensitive 3. About the same

Less radiosensitive | Ova are more radiosensitive in younger girls & after middle age

Most somatic effects occur?

Occur at dose beyond doses during diagnosic radiography

Somatic effects manifest in?

The person who has been irradiated

Which of the following is considered a late somatic effect? 1. Carcinogensis 2. Genetic effect 3. Alzheimer's disease 4. Parkinson's disease

Carcinogensis

What is used to limit the area of the patient being irradiated?

Collimator

Gonadal sheilds may reduce exposure to female gonads by up to what %?

50% | 95% for males

Which of the following sets of exposure factors would resul in the lowest dose to the patient? 1. High mAs, low kVp, 400-seed system 2. Low mAs, High kVp, 400-seed system 3. Low mAs, High kVp, small focal spot,100-seed system 4. Low mAs, High kVp, large focal spot, 100-seed system

Low mAs, High kVp, 400-speed system | Focal spot size does not matter. 400 is faster than 100

Which of the following is used as part of an effort to observe the ALARA concept? 1. Grids 2. Slow-speed system 3. Collimation 4. Thinner filtration

Collimation

The cardinal rules of radiation protection?

Time, Distance, Sheilding

What is used to survey an area for radiation detection and measurments?

Handheld ionization chamber

Which of the following is accurate as low as 10 mrem? 1. TLD 2. Film badge 3. Pocket ionization chamber 4. Handhelp ionization chamber

Film badge | TLD is accurate down to 5mrem

Which of the following include filters for measurement of radiation energy? 1. TLD 2. Film badge 3. Pocket ionization chamber 4. Handheld ionization chamber

Film badge

What may be used to measure in-air exposures in a fluoroscopic room?

Handheld ionization chamber

What detection device sounds an alarm to indicate the presence of radioactivity?

Geiger-Mueller detector

Which of the following is accurate as low as 5 mrem? 1. TLD 2. Film badge 3. Pocket ionization chamber 4. Handheld ionization chamber

TLD | Film badge is as accurate as low as 10 mrem

What is a digital monitor that may be used to measure dose in an area?

Handheld ionization chamber

Which of the following may be used for 3 months at a time? 1. TLD 2. Film badge 3. Pocket ionization chamber 4. Geiger-mueller dector

TLD

Which of the following is sensitive to extremes in environment? 1. TLD 2. Film badge 3. Pocket ionization chamber 4. Handheld ionization chamber

Film badge

For any given exam, the mean marrow dose can be calcuated. What is used to represent the mean marrow dose? 1. GSD 2. ALARA 3. MMD 4. MPD

MMD | MMD stands for Mean Marrow Dose

The radiation dose that wouldcause the same genetic injury to the population as the sum of doses received by individuals actually beaing exposed is called?

GSD | Genetically significant dose

The timer used in fluoroscopy how/why?

Used to alert the fluoroscopist after 5 minutes of fluoroscopy scanning have elapsed.

The most effective protection against radiation exposure for the radiographer is?

Distance

If the dose of scatter radiation in fluoroscopy to the radiographer is 10 mR at a distance of 2 feet from the table, where should the radiographer stand to reduce the dose to 2.5 mR?

4 feet from the table

Lead aprons used in fluoroscopy must be atleast: 1. 0.5-mm lead 2. 0.25-mm lead 3. 0.1-mm lead 4. 0.25mm lead equivalent

0.25-mm lead equivalent (minimum) | 0.5-mm lead equivalent is recommended though!

When and how should holding patiennts for radiographer exams be of concern?

Should only be done when absolutely necessarly, and then the holding should be done by family (non pregnant)

The factors that must be considered in the design of structural sheilding for a radiology room or department include?

Use, occupancy, and workload

The lowest intensity of scatter radiation from the patient is?

At a 90-degree angle from the patient

A film badge reading of M mean?

A dose less than 10 mrem has been received

A reading of 200 mR with a handheld ionization chamber means?

200 milliroentgens has been detected

What is the most accurate personal monitorizing device?

OSL dosimeter | OSL is sensitive as low as 1mrem

Minimum source to skin distance for mobile radiography must be?

12 inches

Positive beam limitation is also known as?

Automatic collimation

Added filtration should be adjusted by the radiographer: 1. to "harden" the x-ray beam 2. To remove the soft rays from the x-ray beam 3. To exercise radiation protectopm 4. Never

Never | Only a physicis can adjust added filtration

Review Questions Flashcards

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