Comprehensive Review Assignment (Final)
1 gray equals: a. 100 cGy. b. 10 J/kg. c. 100 J/kg. d. 1000 cGy.
A
A WR has been established for the following ionizing radiations: x-rays (WR = 1); protons (WR = 2); and alpha particles (WR = 20). What is the total EqD (in sievert) for a person who has received the following exposures: x-rays = 5 Gyt; protons = 10 Gyt; and alpha particles = 5 Gyt? A. 125 B. 12.5 C. 1.25 D. 1250
A
According to the target theory, if only a few non-DNA cell molecules are made dysfunctional by radiation exposure, the cell will probably: a. Not display any evidence of injury after irradiation b. Display only very slight evidence of injury after irradiation c. Display evidence of severe impairment after irradiation d. Die
A
Because high-LET types of radiation deposit more energy per unit length of biologic tissue traversed, they are: a. More destructive to biologic matter than low-LET radiation b. Significantly less destructive to biologic matter than low-LET radiation c. Slightly less destructive to biologic matter than low-LET radiation d. Not comparable to low-LET radiation because they do not deposit any energy per unit length of biologic tissue traversed
A
Early (dererministic) somatic tissue reactions: A. are not common in diagnostic imaging. B. are a result of Grenz rays in a diagnostic x-ray beam. C. occur at doses greater than 3 Gy D. occur at doses greater than 6 Gy
A
Human beings who receive a whole-body dose of ionizing radiation in excess of ______ may die within 30 to 60 days because of effects related to initial depletion of the stem cells of the hematopoietic system. a. 2 Gy b. 3 Gy c. 4 Gy d. 5 Gy
A
If 250 people receive an average EfD of 0.24 Sv, what is the ColEfD in person-sievert? A. 60 person-sievert B. 65 person-sievert C. 70 person-sievert D. 80 person-sievert
A
The NCRP has established an annual occupational EDL of ____ (not including medical and natural background exposure) for the whole body, and a lifetime EfD in mSv that does not exceed _____ times the occupationally exposed person's age in years. a. 5 rem; 1 rem b. 50 rem; 10 rem c. 1 rem; 5 rem d. 10 rem; 50 rem
A
The dosimeter should be worn outside the protective lead apron at collar level because the unprotected head, neck, and lenses of the eye receive ______________ times more exposure than the protected body and trunk. a. 10 - 20 b. 5 - 10 c. 2 - 3 d. Zero (0)
A
The main function of the Nuclear Regulatory Commission (NRC) is to: a. Oversee the nuclear energy industry b. All of the above c. Regulate medical imaging facilities d. Inspect medical imaging facilities
A
To reduce exposure for pregnant female imaging professionals and to control the exposure of the unborn during sensitive periods of gestation, the NCRP now recommends a monthly equivalent dose limit not exceeding _______ per month to the embryo-fetus and a limit during the entire pregnancy not to exceed _______ after declaration of a pregnancy. A. 0.5 mSv; 5.0 mSv B. 5 mSv; 7 mSv C. 250 mSv; 500 mSv D. 150 mSv; 300 mSv
A
Which of the following is/are considered low-LET radiation(s)? a. X-rays and gamma rays b. Alpha particles c. X-rays d. Alpha particles and gamma rays
A
Why are repair enzymes usually able to reverse the cellular damage generally caused by low-level ionizing radiation? a. Damage to DNA is sublethal b. Irradiated cells are hypoxic c. Only organic molecules are damaged d. LET failed to occur
A
Radiation sickness that occurs in humans after whole-body reception of large doses of ionizing radiation (1 Gyt or more) delivered over a short time (from several hours to a few days)
Acute Radiation Syndrome
Radiation in the form of two oppositely moving 0.511-MeV photons generated as the result of mutual annihilation of matter and antimatter
Annihilation radiation
Cytosine bonds only with which of the following nitrogenous organic bases? a. Adenine b. Guanine c. Thymine d. Uracil
B
DNA regulates cellular activity indirectly by transmitting its genetic code information outside the cell nucleus by reproducing itself into the form of __________________. a. Messenger DNA b. Messenger RNA c. Messenger REM d. Transfer RNA
B
Determine the cumulative effective dose (CumEfD) limit to the whole body of an occupationally exposed person who is 38 years old. a. 3.8 mSv b. 380 mSv c. 3800 mSv d. 38 mSv
B
Direct action may occur after exposure to any type of radiation, but it is much more likely to occur after exposure to: a. nonionizing radiation such as microwaves. b. high-LET radiation such as alpha particles. c. low-LET radiation such as gamma rays. d. low-LET radiation such as x-rays.
B
For individual members of the general public not occupationally exposed, the NCRP recommended an annual EDL of ____ for continuous (or frequent) exposures from artificial sources of ionizing radiation other than medical irradiation and natural background and a limit of _____ annually for infrequent exposures. a. 0.5 mSv; 1.5 mSv b. 1 mSv; 5 mSv c. 15 mSv; 50 mSv d. 150 mSv; 500 mSv
B
Genetic mutations at the molecular level are called: A. chromosome mutations. B. point mutations. C. chromatid mutations. D. molecular mutations.
B
If an x-ray photon interacts with and inactivates the human cell's master molecule, what would be the consequence for the cell? a. Loss of intracellular fluid b. Death of the cell c. Disruption of cell chemistry d. Increased pressure on the cell membrane leading to immediate rupture
B
Radiation damage is observed on which of the following three levels? a. Molecular, cellular, and inorganic systems b. Molecular, cellular, and organic systems c. Microscopic, molecular, and organic systems d. Organic, inorganic, and cellular systems
B
The LET value of radiation is an essential factor in: a. Assessing the characteristics of ionizing radiation (e.g., charge, mass, and energy) b. Assessing potential tissue and organ damage from exposure to ionizing radiation c. Determining the OER d. Removing electrons from tissue exposed to ionizing radiation
B
The WR for fast neutrons is 20, and the WT for the stomach is 0.12. If the stomach receives a D of 6 rad from exposure to fast neutrons, what is the EfD in rem? A. 1.44 rem B. 14.4 rem C. 144 rem D. 0.144 rem
B
When a cell divides, the genetic-containing material contracts into tiny rod-shaped bodies called: a. Golgi apparatus b. Chromosomes c. Mitochondria d. Nucleotides
B
When ionizing radiation is used for therapeutic purposes to destroy malignant cells, a very significant effort using the latest advances in imaging and computer treatment planning algorithms is always made to minimize the absorbed dose to healthy surrounding tissue. In radiation therapy, this concept is referred to as a(n): a. Enzyme repair effect b. Therapeutic ratio c. Tissue tolerance effect d. Malignant cell annihilation effect
B
Which of the following radiation quantities is intended to be the best overall measure of the biologic effects of ionizing radiation? a. Exposure b. Effective dose c. There is no radiation quantity that is intended to be the best overall measure of the biologic effects of ionizing radiation. d. Absorbed dose
B
Method for comparing the amount of radiation received from a radiologic procedure of any part of the body with natural background radiation received over a specified period, such as days, weeks, months, or years
BERT
X-ray interaction when electrons undergo deceleration by interaction within the nuclei of the target atoms
Bremsstrahlung interaction
Diagnostic efficacy includes 1. determining if an imaging procedure is justified. 2. obtaining images with minimal radiation exposure. 3. adhering to radiation safety guidelines. 4. revealing the presence or absence of disease in a patient. a. 1, 2, and 3 only b. 2, 3, and 4 only c. 1, 2, 3, and 4 d. 1, 2, and 4 only
C
Electromagnetic radiation traveling through space in the form of a wave but interacts with matter as a particle of energy is referred to as: a. wave attenuation capability b. wave-particle interchangeability c. wave-particle duality d. wave-particle phenomena
C
Of the following radiations, which are classified as ionizing radiation? 1. Infrared rays, low-energy ultraviolet radiation with energy less than 10 eV, and microwaves 2. Low-energy ultraviolet radiation with energy less than 10 eV, radio waves, and visible light 3. Ultraviolet radiation with energy greater than 10 eV, gamma rays, and x-rays a. 1 only b. 2 only c. 3 only d. 1, 2, and 3
C
The most recently available data shows that _______ of the natural background exposure come primarily from the gaseous radionuclide, radon, and to a lesser degree, the radionuclide, thoron. a. 0.1 mSv b. 1.5 mSv c. 2.3 mSv d. 5.5 mSv
C
What term is used for a beneficial effect of radiation in populations continuously exposed to low levels of radiation above the background? A. Nonoccupational EqD effect B. Radiation negligible risk level effect C. Radiation hormesis effect D. Radiation benevolent effect
C
When a technical exposure factor of 100 kVp is selected, which of the following occurs? a. The beam will contain all photons having an effective energy of 100 keV. b. The electrons will be accelerated from the anode to the cathode with an average effective energy of 33 keV. c. The beam will contain photons having energies of 100 keV or less, with an average effective energy of approximately 33 keV. d. The electrons will be accelerated from the cathode to the anode with an average effective energy of 33 keV.
C
Which of the following are the responsibilities of radiation workers? Perform periodic exposure audits to determine how to lower radiation exposure in the workplace Perform duties consistent with ALARA Be aware of the rules governing the workplace a. 1 and 2 only b. 1 and 3 only c. 2 and 3 only d. 1, 2, and 3
C
Which of the following increases radiation exposure to the patient and potentially to the radiographer? a. Production of optimal quality images with the first exposure b. Use of appropriate radiation protection procedures c. Repeated radiographic exposures as a result of technical error or carelessness d. Limited radiographic examination, as ordered by the radiologist
C
Which of the following places human beings in closer contact with extraterrestrial radiation? A. PA and lateral digital radiographic images of the chest B. Deep-sea diving C. A flight on a commercial airplane D. Visit to a nuclear power plant
C
Classic method of displaying the sensitivity of a particular type of cell to radiation
Cell Survival Curve
X-ray interaction when an electron from the inner K-shell of the target atom is knocked out of orbit from an incident electron and ejected from the atom.
Characteristic Radiation
Most likely to occur at low energy, typically less than 10 keV
Coherent scatter
Interaction of an x-ray photon with a loosely bound outer-shell electron of an atom
Compton scattering
A biologic reaction is produced by 4 Gy (400 rad) of a test radiation. It takes 16 Gy (1600 rad) of 250-kVp x-rays to produce the same biologic reaction. What is the relative biologic effectiveness (RBE) of the test radiation? a. 1 b. 8 c. 2 d. 4
D
Compton scattering is synonymous with: a. photoelectric absorption. b. photodisintegration. c. coherent scattering. d. incoherent scattering.
D
Convert 7 Gy to Rad a. 70 Rad b. 0.07 Rad c. 7 Rad d. 700 Rad
D
If a radiographer stands 2 meters away from the X-ray tube and receives an exposure rate of 5 mR/Hr, what will the exposure rate be if the same radiographer moves to stand at a distance of 10 meters from the X-ray tube? a. 125 mR/Hr b. 2 mR/Hr c. 1.25 mR/Hr d. 0.2 mR/Hr
D
In order to initiate pair production, the energy of the x-ray photon must be: a. 1.022 keV b. 0.511 MeV c. 0.511 keV d. 1.022 MeV
D
The amount of energy per unit mass absorbed by an irradiated object
D
X-rays: 1. Reduce the amount of the x-ray "beam on" time 2. Use as much distance as warranted between the x-ray tube and the patient for the examination 3. Use specific area shielding devices a. 1 and 2 only b. 1 and 3 only c. 2 and 3 only d. 1, 2, and 3
D
A measure of the amount of radiant energy that has been thrust into a portion of the patient's body surface
DAP
Biologic damage that occurs as a result of ionization of atoms on essential molecules produced by an immediate interaction with incident radiation
Direct action
The passage of primary x-ray photons through a patient without interaction in body tissue.
Direct transmission
Fraternal twins
Dizygotic twin
The product of D × WR × WT
EfD
Radiation quantity intended to be the best estimate of overall harm that might be produced by a given dose of radiation in human tissue
Effective Dose (EfD)
Electric and magnetic fields that fluctuate rapidly as they travel through space, including radio waves, microwaves, visible light, and x-rays
Electromagnetic wave
Radiation quantity that takes into account the type of ionizing radiation that was absorbed.
EqD (equivalent dose)
X-ray photons that emerge from human tissue and strike the radiographic image receptor after passing through the patient being radiographed
Exit, or image formation, photons
The amount of ionization produced in air when ionizing radiation is present.
Exposure
Attenuation is any process that increases the intensity of the primary photon beam directed toward a destination such as the radiographic image receptor. (T/F)
False
EfD enables the calculation of the EqD (T/F)
False
The embryo-fetus contains large numbers of mature, specialized cells and therefore is relatively radioresistant. (T/F)
False
Device with an audible sound system that alerts the operator to the presence of ionizing radiation
GM survey meter
SI unit used to express D
Gy
A multistage process that first involves the production of reactive free radicals that are created by the interaction of radiation with water (H2O) molecules
Indirect action
Cutie pie
Ionization chamber-type survey meter
Signifies the whole-body dose of ionizing radiation that can be lethal to 50% of an exposed population within 30 days
LD 50/30
The radiosensitivity of cells is directly proportional to their reproductive activity and inversely proportional to their degree of differentiation
Law of Bergonie and Tribondeau
Indicates that the biologic effect responses will be caused by ionizing radiation in living organisms in a directly proportional manner at any dose above zero
Linear nonthreshold dose-response curve
Process of reduction cell division
Meiosis
Process of cell division that results in two daughter cells identical to the parent cell.
Mitosis
Identical twins
Monozygotic twins
After threshold, as dose increase, the biologic damage increases sharply to a point then damage remains the same no matter the dose
Non-linear threshold dose-response curve
Device used for personnel monitoring of occupational exposure that contains an Al2O3 thin layer detector
OSL
Synonymous with the acronym ALARA
Optimization for radiation protection (ORP)
Interaction in which the energy of the incoming photon is transformed into two new particles, a negatron and a positron
Pair production
A small (several mm3) ionization gas-filled dosimeter connected to a solid-state device, with electrically erasable read only memory (EEPROM) or erasable read only memory (EPROM)
Personnel DIS dosimeter
Incoming high-energy photon, above 10 MeV, collides with atomic nucleus and is absorbed. The nucelus can then release a netron, deutron, or alpha particle.
Photodisintegration
X-ray interaction with matter where the energy of the incident photon is completely absorbed
Photoelectric absorption
Describes the comparative capabilities of radiation with differing LETs to produce a particular biologic reaction
Relative Biologic Effectiveness (RBE)
SI unit of EqD
Sievert (Sv)
A device worn by an imaging professional as a second monitor when performing fluoroscopic procedures that require the hands to be near the primary x-ray beam
TLD
Device that measures the amount of ionizing radiation to which a TLD ring dosimeter has been exposed
TLD analyzer
Hypothesis that when a vital macromolecule such as DNA is directly or indirectly inactivated by exposure to radiation, the cell will die
Target theory
Wave-particle duality means that electromagnetic radiation travels through space in the form of a wave but can interact with matter as a particle of energy called a photon. (T/F)
True
A dimensionless factor (a multiplier) that was chosen for radiation protection purposes to account for differences in biologic impact among various types of ionizing radiation
WR
To implement an effective radiation safety program in a facility that provides imaging services, the employer must provide all of the following except:
X-ray equipment that can produce only very low kilovoltage and very high milliamperage
Form of ARS that occurs when people receive whole-body doses of ionizing radiation ranging from 1 to 10 Gyt
bone marrow syndrome
Form of ARS that results when the central nervous system and the cardiovascular system receive ionizing radiation doses of 50 Gyt or more
cerebrovascular syndrome
The degree to which the diagnostic study accurately reveals the presence or absence of disease in the patient while adhering to radiation safety guidelines
diagnostic efficacy
The radiation dose that causes the number of spontaneous mutations occurring in a given generation to increase to two times their original occurrence
doubling dose
Early somatic effects on organ systems that result from high doses of radiation and appear within minutes, hours, days, or weeks after exposure
early tissue reactions
Form of ARS that appears at a threshold dose of approximately 6 Gyt
gastrointestinal syndrome
Estimates the risk associated with low-level radiation
linear quadratic nonthreshold dose response curve
Sensing material found in TLD ring dosimeters
lithium fluoride (LiF)
Most common SI unit of measure of EqD
mGy
SI unit for the radiation quantity ColEfD
person-sievert
Generally used in a laboratory setting to detect alpha and beta radiation and small amounts of other types of low-level radioactive contamination
proportional counter
The total kinetic energy released in a unit mass of tissue
tissue kerma
