Review Questions Flashcards
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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.
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
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
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
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
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
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
What is the traditional unit of measurment that equals 100 ergs of energy deposited per grams of tissue?
RAD - Radiation absorbed dose
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”
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
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
