Chapter 4 Radiation Protection Answer Key

Page7 1. The 8-inch PID is more effective than 16-inch PID in reducing radiation exposure of the patient. a) True b) False 2. The thyroid collar must be worn for both intraoral & extraoral exposures. a) True b) False 3. Which PID is most effective in reducing patient exposure? a) Conical b) Rectangular c) Circular d) All of above 4. Which device restrict the size & shape of x-ray beams? a) Filter b) Collimator c) Barrier d) Film badge 5. Which term describes the dose of radiation that the body can endure with little or no damage? a) Radiation limit b) Maximum permissible dose (MPD) c) Occupationally exposed dose d) ALARA 6. If kVp is decreased and exposure time increased, the resulting image demonstrates: a) Greater contrast b) Reduced contrast c) Increased density d) Decreased density 7. What is the most critical factor influencing image quality? a) mA b) kVp c) Exposure time d) Self-rectifying unit 8. What is position & distance rule? a) 4 feet away, 45-90 degree to central ray b) 5 feet away, 180 degrees to central ray c) 6 feet away, 90-135 degree to central ray d) 6 feet away, 135-180 degree to central ray 9. Optimal patient exposure: a) 60-80 kVp b) 6-8 mA c) Shortest exposure time d) All of above 10. The dental radiographer may hold a receptor in patients’ mouth, the radiographer must never hold xray tube head a) Both true b) Both false c) First sentence false, second true d) Second sentence false, first true 11. As low as reasonably achievable: a) Exposure time b) Dose c) ALARA d) None 12. What is indicated in this picture? a) Palate b) Nothing is dangerous c) Inflammation d) Torus palatinus 13. We incline the focal spot to 20 degrees to: a) Ensure the final image sharper b) More in size c) Less damaging d) More cheap 14. Choose the correct answer: a) Inherent filtration includes lidded glass window, insulting oil b) Added filtration is aluminum discs c) 8-inch PID is better than 16-inch PID d) A+B only 15. The thickness of the aluminum filter is __ dependent: a) mA b) Exposure time c) kVp d) distance 16. using F-speed film (Insight) rather than D-speed (Ultraspeed) reduces exposure by: a) 20% b) 40% c) 60% d) 80% 17. In case of pregnancy, if the mother’s oral condition is mild and is not painful, we don’t use radiography, while if her case is sever and there is a large carious lesion if seen, a radiograph must be done. a) True b) False 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 b b b b b a c c d c c d a d c c a