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RADT465RadProtection
ARRT review
Question | Answer |
---|---|
What is ionization caused by? | high-energy, short-wavelength electromagnetic radiation that break apart electrically neutral atoms pg 225 |
Name the two types of x-radiation are produced at the anode through energy conversion processes. | Bremsstrahlug and characteristic radiation pg 227 berms comprises 70-90 percent of the x-ray beam. |
What are dose- response curves represent? | they are used to illustrate the relationship between exposure to ionizing radiation and possible resultant biologic responses pg 230 |
Define Linear. | linear relationship are those in which the response is directly related to the dose received , if the dose is increase the biologic response is increased page 230 |
Define nonlinear. | effects are not proportional to the dose page 230 |
Define threshold. | refers to the dose below which non harmful effects are likely to occur, or the point/dose at which a response first begins. |
Define non-threshold. | no safe dose even one photon can cause a response page 231 |
What is direct effect? | direct effect occurs when the ionizing particle (an electron) interacts directly with the key molecule (DNA) or another critical enzyme or protein. page 234 |
What is indirect effect? | indirect effects, which occurs most frequently, happens when ionization takes place away from the DNA molecule in cular water. |
What is radiolysis? | ionization of water molecules in the body breaks water molecules into smaller molecules often production one or more atoms having unpaired electrons page 234 |
What is the Law of Bergonie and Tribondeau? | states that the most radiosensitive cells are young, undifferentiated, and highly mitotic cells. page 237 |
What is the most radiosensitive cell? | Lymphocyte pg 237 |
what is somatic effect? | are described as being early or late depending on the length of time between irradiation and manifestation of effects. page 240 |
What are occupationally exposed personnel are concerned with? | the late effects of radiation exposure page 242 |
Define beam restriction? | that is limitation of irradiated field size, is probably the single most important factor in keeping patient dose to a minimum, the primary beam must be confined to the area of interest so that only that tissues of diagnostic interest should be irradiated |
What is inherent filtration? | is that in which a filtration is built-in and it is composed of materials that are a permanent part of the x-ray tube and its tube housing. page 253 |
There are two types of AEC list them. | ionization chamber type and phototimer type page 260 |
explain reproducibility. | for a given group of exposure factors, output intensity must be consistent from one exposure to the next; any variation in output intensity must not exceed 5% page 262 |
Difference between primary and secondary barriers. | primary barriers-protect from the useful beam and secondary barriers protect from scattered and leakage radiation page 272 |
List the cardinal principles of radiation protection? | time, distance, and shielding |
roentgen measures what? | measures ionization in air |
Rad is .... | acronym for radiation absorbed dose |
Rem is .... | acronym for radiation equivalent man in SI unit measurement of Sv (Sievert) used to quantify biologic effectiveness |
What is a film badge? | low-cost radiation monitors that are processed monthly |
What is TLD? | thermoluminescent dosimeter contains crysitallins chips of lithium fluoride. LiF absords and stores the energy associated ionizing radiation. page 285 |
Lifetime cumulative exposure for the occupationally exposed individual is determined by? | 1 rem times age in years page 289 |