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Radd Protection
Test Questions
Question | Answer |
---|---|
When exposed to high radon levels in the home, what group of people have the highest risk of developing lung cancer? | Smokers |
In the electromagnetic spectrum, higher frequencies are associated with: | Shorter wavelengths and higher energies |
The advantages of the BERT method are (3) | 1. it doesnt imply radiation risk; its a means for comparison 2.it emphasizes that radiation is an innate part of our enviornment 3.the answers are given in terms of BERT are easier for the pt to understand |
Particles associated with electromagnetic radiation that have NO mass or electric charge are | Xray photons |
The symbol Z indicates | Atomic # of an atom |
In photoelectric absoprtion, the kinetic energy of the incoming xray photon must be ____ to be able to dislodge an inner shell electron from its orbit | Have the same or greater then the energy that binds the electron in its orbit |
What term refers to the radiation that occurs when an electron drops down from an outer orbit to fill a vacancy in an inner orbit of the parent atom? | Characteristic radiation |
In the diagnostic radiology energy range, what possess the greatest ability to absorb radiant energy thru the process of photoelectric absoprtion | Bone |
What type of ionizing radiation produces virtually the same biological effect for equal absorbed doses in body tissue? | Xrays, beta particles, and gamma rays |
Beta particles are actually | High speed electrons |
Terrestrial radiation includes what sources? | Radioactive elements such as uranium-238 radium-226 and thorim-232 that are present in variable quantities in the crust of the earth |
What are 3 forms of EM radiation? | Microwaves, Visible light, Xrays |
The millisievert (mSv) is equal to | 1/1000 of a sievert |
The velocity of light is written as | c=3x10(8) m/s |
Atoms and molecules are the fundamental building blocks of | Matter |
A moving object has ____ energy | Kinetic |
What is the removal of an electron from an atom called? | Ionization |
What is NOT a type of an interaction b/t x-radiation and biological matter? | Bremsstrahlung |
If a pt recieving xray therapy treatment receives a total doasge of 6000rads, the dosage may be recorded as _____ if the SI system is used | 6000 cGy |
What are NOT SI units? | Roentgen, Rad and rem |
What means "random in nature" | Stochastic |
The ALARA concept presents an extremely conservative model with respect to the relationship between: | Ionizing radiation and potential risk |
The essential concept underlying radiation protection is that | Any organ in the human body is vulnerable to damage from exposure to ionizing radiation |
A pt may elect to assume the relativley small risk of exposure to ionizing radiation to obtain essential diagnostic medical information when (3) | 1. illness occurs 2. injury occurs 3. a specific imaging procedure for health screening purposes is prudent |
Effective measures employed by radiation workers to safegaurd pts, personnel, and the general public from unnecessary exposure to radiation defines: | Radiation protection |
Which of the following is a method that can be used to answer pt questions about the amount of radiation received from a radiographic procedure | BERT |
The term OPTIMIZATION FOR RADIATION PROTECTION (ORP) is synonymous with the term: | ALARA |
What are natural sources of ionizing radiation? | Radioactive elements in the crust of the earth and in the human body |
An equivalent dose as low as .25Sv (25rem) delivered to the whole body may cause what within a few days? | A decrease in the number of lymphocytes in the circulating blood |
The degree to which the diagnostic study accurately reveals the presense or absense of disease in the pt defines what term | Diagnostic efficacy |
What was the total average annual effective dose from manmade and natural radiation as of 1987? | 3.6mSv 360mrem per year |
An effective radiation safety program requires a firm commitment to radiation safety by (2) | Facilities providing imaging services and radiation workers |
What is recognized as the main adverse health effect from the 1986 Chernobyl nuclear power accident? | Increase in the incidence of thyroid cancer in children and adolescents |
Exit or image formation, radiation is composed of what? | Non interacting and small angle scattered photons |
What contributes significantly to the exposure of the radiographer? | Compton scatter PHOTONS |
What are 2 words that define attenuation? | Absorption and scatter |
What interaction occurs with matter when then energy of the inicident photon is PARTIALLY absorbed? | Compton |
When a high atomic number solution is either ingested or injected into human tissue or a structure to visualize it during a procedure, what occurs? | Photoelectric interation becomes significantly enhanced, leading to an increase in the absorbed dose in the body tissues or structures that contain the contrast medium |
What was used as the first measure of exposure for ionizing radiation? | Skin erythema |
What is the unit for collective effective dose ColEfD | Person-sievert |
The concept of tissue weighting factor Wt is used to do which of the following? | Account for the risk to thenetire organism brought on by irradiation of individual tissues and organs |
If the absorbed dose is stated in rad, gray may be determined by performing which of the following operations? | Dividing by 100 |
What does the traditional unit the roentgen measure? | Radiation exposure in air only |
What radiation quanitity accounts for some biological tissues being more sensative to radiation damage then other tissues? | Effective dose |
What is determined by dividing the number or rad by 100? | Number of gray |
In general, what can human cells do? (3) | Protect themselves, regulate life processes, reproduce |
Inorganic materials are comounds that | do not contain carbon |
Whats considered low-LET radiation? 2 | Xrays and Gamma rays |
While passing through a human cell, an xray photon interacts with an inactivates the cells master molecule. What is the consequence for the cell? | Death |
What group is least radioSENSATIVE? | Adult nerve cells |
What group is most radiosensative? | The embryo-fetus during the 1st trimester of pregnancy |
Based on current data, which of the following would be considered safe radiation dose for the gonads of both males and females? | NOTHING |
T/F Pts are not expected to sustain appreciable damage to either blood or the blood forming organs as a consequence of the exam | TRUE |
What group of cells is most radiosensative | Lymphocytes |
Direct action may occur after exposure to any type or radiation, but it is much more likley to happen after exposure to | High-LET radiation such as alpha particles |
As LET increaases, the ability of ionizing radiation to cause biological effects | Also generally increases until it reaches a maximum value |
Radiosensativity of a ova | Varies considerably throughout the lifetime of a germ cell |
What tissues do not divide? | Muscle tissue and nervous tissue in the adult |
There are ___ pairs of chromosomes | 23 |
In a DNA macromolecule, the sequence of ____ determines the characteristcs of every living thing | Nitrogenous organic bases |
How many base pairs are there in the human genome? | 2.9x10-9 |
Radiation induced chromosome damage may be evaluated during what process? | Metaphase |
If exposure to ionizing radiation damages the components involved in molecular synthesis beyond repair, cells do what? | Function abnormally and die |
What produces antibodies? | Lymphocytes |
Water constitues aprox ___ of the weight of the human body | 80-85% |
What must the human body provide to ensure efficient cell operation? 3 | Food as a source of raw material for the relase of energy 2. oxygen to help break down food 3. water to transport inorganic substances into and out of the cell |
What human cell component controls cell division and multiplication as well as biochemical reactions that occur within the cell? | Nucleus |
What term is used to describe chemical secretions that are manufactured by various endocrine glands and carried by the blood stream to influence the activities of others part of the body? | Hormones |
Somatic cells divide through the process of | Mitosis |
For radiation protection, high-LET radiation is of greatest concern when a radionuclide has been implanted, ingested, or injected or inhlaed because | The potential esists for irreparable damage because multiple strand breaks in DNA are possible |
Free radicals behave as an extremely reactive single entity as a result of the presence of | unpaired electrons |
Whats classified as high-LET radiation | Alpha particles |
What action of ionizing radiation is most harmful to the human body? | Indirct action |
Which molecules in the human body are most commonly directly acted on by ionzing radiation to produce molecular damage through an indirect action? | Water |
When does ionizing radiation cause complete chromosome breakage? | When 2 driect hits occur in the same rung of the DNA macromolecule |
When significant numbers of lymphocytes are damaged by exposure from ionizing radiation, the body: 3 | Loses its natural ability to combat infection 2. becomes more susceptible to bacteria 3. becomes more susceptible to vital antigens |
With respect to the law of Bergonie and Tribondeau, "The most pronounced radiation effects occur in cells having _____" | Greatest reproductive activity, longest mitotic phases and least maturity |
What do basal cells of the skin, interstinal crypt cells, and reproductive cells have in common? | There are radiosensative |
Lethal dose of ionizing radiation for humans is usually given as | LD 50/60 |
Acute radiation syndrome presents in 4 major response stages. What order do they occur? | Prodromal, Latent petiod, manifest illness, recovery or death |
What system is the most radiosensative vital organ system in human beings? | Hematopoietic |
When cells are exposed to sublethal doses of ionizing radiation, approx ____ of radiation induced damage may be repaired over time and about ___ is irreparable | 90%, 10% |
As radiation dose increases, the severity of early effects | also increases |
The total radiation dose received by a somatic or genetic cell and the dose rate determine the | Production of choromosome aberrations |
In 1898, after developing burns attributed to radiation exposure, this boston dentist began investigating the hazards of radiation exposure and became the first advocate of radiation protection | William Herbert Rollins |
In the female, the ovarian stem cells | Multiply to millions of cells only during fetal development, b4 birth, and then steadily decline in # throughout life |
What types of cells develop from a single precursor cell, the pluripotential stem cell | Lymphocytes, granulocytes, thrombrocytes, erthrocytes, platelets |
With regard to radiation exposure, which part of the GI tract is most severly affected? | Small intestine |
Cancer and genetic effects are examples of ___ effects | Stochastic |
Some examples of measruable late biologic damage are | cataracts, leukemia and genetic mutations |
Which of the following provide the foundation for the S shaped threshold curve of radiation dose response | Data from human populations observed from acute high doses of radiation |
The linear nonthreshold cruve implies that biologic response is | directly proportional to the dose |
Reevaluation of the quanitity and type of radiation that was released in the atomic bombing of Hiro and Naga has led to revised atomic bomb data in which radiation induced leukemia and solid tumors may now be attributed to | gamma radiation exposure |
Early demise of experimental animals exposed to nonlethal doses of ionizing radiation actually resulted from | induction of cancer |
According to data from studies performed on US Rad techs, individuals who began working before 1950 had a somewhat higher risk of dying from ____ when compared to techs who started working in 1950 and later | Leukemia |
Most diagnostic procedures result in equivalent doses | less than .01Sv 1rem |
What agency is responsible for enforcing radiation safety standards? | NRC |
Determine the CumEfD to the whole body of an occupationally exposed person who is 27 years old | 270mSv |
Biological effects such as cataracts that result from exposure to ionizing radiation appear to have what kind of curve | Sigmoid threshold dose response curve |
For rad workers, occupational risk may be equated with occupational risk how | Other industries are generally considered reasonably safe |
Revised estimates derived from recent reevaluations of dosimetric studies on the atom bomb survivors of Hiro and Naga indiciated what | an increase in the number of solid tumors in the survivor population |
When exposed to radiation as part of their education expeirence, an 18 year old student should not exceed an EfD of __ annually | 1mSv .1rem |
What group of ppl have provided sufficient evidence of the induction of stochastic effects in humans resulting from high radiation absorbed doses | Japanese atomic bomb survivors |
Responsibilities of the RSO include | Developing an appropriate radiation safety program and maintaing radiation monitoring records for all personnel |
Monthly EqD for fetus ____ and full term ___ | .5mSv and 5mSv |
What is the annual occupational EfD that applies to rad techs during routine operations? | 50mSv, 5rem |
Radiation induced cataracts in humans follow a ______ dose response relationship | Nonlinear, threshold |
What is not a form of acute radiation syndrome? Carcinogenic, hematopoetic, GI, cerbrovascular | Carcinogenic syndrome |
Mutations in genes and DNA that occur at random as natual phenomena are called | Spontaneous mutations |
3 diorders classified as early (acute) deterministic somatic effects of ionizing radiation | Nausea, epilation, intestinal disorders |
What terms means "random in nature" | Stochastic |
When whole body occupational exposure is controlled by keeping the EfD well below the upper boundry limit, the possibility of inducing stochastic effects of radiation is | minimized |
In general, nonstochastic effects occur | only after large doses of radiation |
Damage to the reproductive cells of the human male and female that are caused by irradiation of sperm and ova b4 conception is termed | mutagenesis |
Is a filter an xray beam limitation device? | No |
When the speed of screen film systems is double, pt radiation exposure is ____ by aprox ___ | reduced by 50% |
When using digital fluoro systems, making use of the last image hold feature can | Be an effective dose reduction technique |
During a mobile radiographic procedure, to reduce the radiation exposure rate and thereby the amount of radiation that a pt receives, the radiographer must use a minimal source skin distance of | 30 cm (12 in) |
Federal government specifications recommend a minimum total filtration of ____ for stationary (fixed) fluoro xray units operating above 70kVp | 2.5-mm Al equivalent |
The radiographic beam should be collimated so that it is what with the IR? | No larger then the IR |
Both alignment and length and width dimensions of the radiographic and light beams must correspond to within:....SID | 2% of the SID |
What is the function of a filter in diagnostic radiology? | To decrease the x-radiation dose to the pt skin and superficial tissue |
HVL may be defined as the thickness of a designated absorber required to do what.. | decrease the intensity of the primary beam by 50% of its initial value |
T/F a radiographic grid is used more frequently in CR | True |
To minimize skin exposure to electrons produced by photon interactions with the collimator, how far below the collimator should the pt skin surface be | At least 15cm below |
To decrease pt exposure during fluoro, the fluoroscopist can | Limit the size of the fluoroscopic field to include only the area of anatomy that is of clinical interest and employ the practice of intermittent or pulsed fluoroscopy to reduce the overall length of exposure |
The diagnostic type protective tube housing must be constructed so that leakage radiation measued at a distance of 1m from the xray source does not exceed _____ when the tube is operated at its highest voltage at the highest current that allows continuous | 100mR/hr (2.58x10-5 C/kg per hour |
As a consequence of their anatomic location, the female reproductive organs receive about ___ exposure during a given exam involving the pelvic region | 3x more |
In fluoro, how is the amount of radiation that a pt receives usually estimated? | By measuring the rad exposure at tabletop and multiplying this by fluoro time |
Direct pt shielded is typically not used in | CT |
Peds require special consideration and approp radiation protection procedures bc they are more vulnerable to what? | Both the late and somatic effects and genetic effects of radiation |
The use of a PA projection during a peds sciolosis exam results in what? | Lower extrance exposure dose to the anterier body and therby reducing dose to the breast |
FDA says screening mammos mean dose is | 3mGy (300rad) per view |
What 2 exams are considered unneccessary rad procedures | chest xrays for physicals, whole body multislice spiral ct screening |
What adjustments in technical exposure factors decreases the production of scatter radiation | Increase kVp and decreases mAs in compensation |
If the intensity of the xray beam is inversely proportional to the square of the distance from the source, how does the intensity of the xray beam change when the distance from the source of radiation and a measurement point is tripled | It decreases by a factor of 9 at the new distance |
The metal filters contained in a film badge are generally composed of which of the following materials | Aluminum or copper |
What is the maximum period of time that a TLD may be worn as a personnel dosimeter | 3 months |
What do OSL, pocket ionization chambers and TLDs all have in common | These devices are all used to personnel monitoring |
What instrument is called a cutie pie | Ionization chamber type survey meter |
When the sensing crystals containedin the TLD are exposed to ionizing radiation, what occurs | Some of the electrons in the crystalline lattice structure of the LiF molecule absorb energy are excited to higher energy levels |
Another way to reduce the production of scatter other then collimation is | Compresson |
When performing portables, the radiographer should stand at | right angles (90 angles) from the pt |
At a 90 angle to the primary beam, at a distance of 1m (3.3 ft) the scattered radiation is what fraction of the intensity of the primary beam | 1/1000 |
What are 2 methods to reduce occupational exposure during fluoro | Collimate, use the foot pedal |
If the bucky slot shielding device and spot film device protective curtain or sliding panel were not in the correct position during fluoro, what would happen 2 the exposure rate | it would exceed an exposure rate of 100mR/hr at a distance of 2ft from the side of the xray table |
Units of either mAs/wk or mA-min/wk are used to determine the _____ for a specific xray room | Workload |
For portables, the cord has to be | 6 ft, 2m |
What 3 factors are considered when determining thickness requirements for protective barriers | Occupancy factor (T) Workload (W) Use factor (U) |
When laser light is incident on the sensing material in an OSL dosimeter, the material | Becomes luminescent in proportion to the amount of radiation exposure received |
What chemicals are in TLD | Lithium Flouoride |
What 3 requirements must radiation survey instruments fulfill? | 1.must be reliable by accurately recording exposure or exposure rate 2.durable enuff 2 withstand normal use 3.interact with ionizing radiation in a manner similar to the way human tissue does |
What instrument is used to calibrate radiographic and fluoro xray equipment | Ionization chamber with electrometer |
For xray and gamma ray photons with energies of 5keV to in excess of 40MeV, the _____ gives an accurate reading as low as 1mrem | OSL |
What instrument should be used to located a lost radioactive source or detect low level radioactive contaimination | GM detector |
What instrument should be used in an xray installation to assess fluoro scatter radiation exposure rate? | Ionization chamber with electrometer |