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RADT 456 Unit 5
ARRT registry review covering Unit 5: Radiation Protection
Question | Answer |
---|---|
1. According to NCRP, what is the monthly gestational dose-equivalent limit for embryo/fetus of a pregnant radiographer? | 5 mSv |
2. What cell type has the greatest radiosensitivity in the adult human? | lymphocytes |
3. What interaction between ionizing radiation and the target molecule that is most likely to occur? | indirect effect |
4. What is the approximate entrance skin exposure for the average AP supine abdomen radiograph? | 300 mrad |
5. What is the established annual occupational dose-equivalent limit for the lens of the eye? | 150 mSv |
6. What contributes the most to occupational exposure? | compton scatter |
7. What x-ray interaction with matter is responsible for the majority of scattered radiation reaching the IR? | compton scatter |
8. What type of crystals done a thermoluminescent dosimetry system use? | lithium fluoride |
9. Medical and dental radiation accounts for what percentage of the general public's exposure to human-made radiation? | 90% |
10. How does filtration affect the primary beam? | increases the average energy of the primary beam |
11. What is the minimum lead requirement for lead aprons, according to the NCRP? | 0.50mm Pb |
12. What is the appropriate ESE for the average upright PA chest radiograph using 15 kVp and a grid? | 20 mrad |
13. Primary radiation barriers must be at least how high? | 7 ft |
14. What unit of measure is used to express ionizing radiation dose to biologic material? | Rem (Sv) |
15. What is the skin response to radiation exposure that appears as hair loss called? | epilation |
16. What is the reduction in the intensity of an x-ray beam as it passes through material called? | attenuation |
17. What are late effects of radiation, whose incidence is dose related and for which there is no threshold dose, referred to as? | stochastic |
18. According to NCRP regulations, leakage radiation from the x-ray tube must not exceed____ | 100 mR/h |
19. Primary radiation barriers usually require what thickness of shielding? | 1/16 inch lead |
20. The skin response to radiation exposure, which appears as reddening of the irradiated skin area, is known as ______ | erythema |
21. The amount of time that x-rays are being produced and directed toward a particular wall is referred to as the ____ | use factor |
22. What acute radiation syndrome requires the largest exposure before any effects become apparent? | CNS |
23. What type of personnel radiation monitor can provide an immediate reading? | ionization chamber |
24. Isotopes are atoms that have the same ____ | atomic number but a different mass number |
25. What is the automatic exposure device that is located immediately under the x-ray table? | ionization chamber |