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April 18, 2009

April 18, 2009. Sources of Radiation in the general public. The main sources of exposure to radiation in the general public are (generally speaking) natural . The most significant natural source is exposure to radioactive Radon gas.

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April 18, 2009

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  1. April 18, 2009

  2. Sources of Radiation in the generalpublic The main sources of exposure to radiation in the general public are (generally speaking) natural. The most significant natural source is exposure to radioactive Radon gas. The primary artificial exposure makes up a small share of the overall exposure, and mostly consists of radiation received from chest and dental x-ray procedures.

  3. Additional remarks about Radon exposure Radon is a radioactive noble gas (decays via alpha particle emission), which accumulates in larger quantities indoors since Radon is denser than air. Radon is a daughter product of Uranium decay, and is found in larger quantities where minerals rich in Uranium (e.g. pitchblende) are found.

  4. Sample Exam Questions:2006 Board Recalls 58. Which of the following are multiple disks for short term memory in PACS? a. jukebox b. RAID c. ROM d. RAM

  5. Sample Exam Questions:2006 Board Recalls 59. What is HL-7 in relation to PACS? a. communication/interface to HIS b. security measure to protect PACS c. way of storing and communicating images across PACS

  6. Sample Exam Questions:2006 Board Recalls 59. Two films with an OD of 1.0 each are superimposed on a viewbox with brightness of 3000 cd/m2. What will be the brightness you will see. a. 300 b. 30 c. 100 d. 10

  7. Sample Exam Questions:2006 Board Recalls 64. What is the unit for Dose are product (DAP)? a. mGy cm2 b. mGy/cm2

  8. Sample Exam Questions:2006 Board Recalls 66. If the source to image distance increases from 50cm to 75cm, what do you have to do to the mAs to keep the same optical density using the same kVp? a. keep mAs the same b. increase mAs by 9/4 c. decrease mAs by 9/4

  9. Sample Exam Questions:2006 Board Recalls 68. To improve breast contrast in mammogram which of the following can you do? a. decrease kVp from 30 to 25 b. increase kVp from 26 to 36 c. use smaller focal spot

  10. Sample Exam Questions:2006 Board Recalls 72. A radionuclide has biological half life of 4 days and physical half life of 13 days. What is effective half life in days? a. 1 b. 3 c. 4 d. 8.5

  11. Sample Exam Questions:2006 Board Recalls 74. Exposure is measured using what? a. ionization chamber and electrometer b. GM counter c. PMT d. Densitometer

  12. Sample Exam Questions:2006 Board Recalls 76. An image intensifier has 512 x 512 matrix with 25 cm field of view. What is spatial resolution? a. 0.6 lp/mm b. 1 lp/mm c. 2 lp/mm d. 3 lp/mm e. 4 lp/mm

  13. Sample Exam Questions:2006 Board Recalls 82. You are doing a fluoro exam in a child looking for reflux. What can you do to decrease exposure? a. remove grid. b. go to magnification mode c. increase fluoro time

  14. Sample Exam Questions:2006 Board Recalls 83. In a helical CT of a child, all can be used to reduce dose except? a. decrease kVp b. decrease mAs c. decrease pitch d. decrease scan time

  15. Sample Exam Questions:2006 Board Recalls 85. In direct digital imaging, technologist accidentally doubles exposure. What is effect? a. image will be completely dark b. image will be completely white c. will increases ability to visualize large low contrast lesions

  16. Sample Exam Questions:2006 Board Recalls 87. Digital chest x-rays do not use which of the following? a. histogram equalization b. recursive filters c. look up tables d. low pass spatial filtration

  17. Sample Exam Questions:2006 Board Recalls 90. A 55 year old male undergoes a 5 hour cardiac angioplasty procedure using fluoro. Two weeks later he comes with a pruritic rash on posterior part of his R. thorax. What is the cause? a. burn from defibrillation b. rash from ekg leads c. radiation induced burn

  18. Sample Exam Questions:2006 Board Recalls 94. What is binding energy? a. amount of energy to release an orbital electron from an atom.

  19. Sample Exam Questions:2006 Board Recalls 95. In a photoelectric interaction, the photon interacts with what? a. nucleus b. orbital electron

  20. Sample Exam Questions:2006 Board Recalls 97. Background radiation at sea level is mostly due to what? a. radon

  21. Sample Exam Questions:2006 Board Recalls 98. What accounts for most man-made exposure to general public? a. medical and dental x-rays.

  22. Sample Exam Questions:2006 Board Recalls 99. How do you decrease magnification with a constant SID? a. increase SOD b. decrease SOD

  23. Sample Exam Questions:2006 Board Recalls 108. A scattered x-ray at 90 degrees at one meter is what fraction of original intensity? a. 1/10 b. 1/100 c. 1/1000

  24. Sample Exam Questions:2006 Board Recalls 116. What part of the atom determines chemical behavior? a. binding electrons

  25. Sample Exam Questions:2006 Board Recalls 117. What is most of the interaction of a Tc-99m gamma ray in soft tissues of a patient? a. photoelectric b. Compton scatter c. pair production

  26. Sample Exam Questions:2006 Board Recalls 120. What is radiation induced leukemia an example of? a. stochastic genetic effect b. stochastic somatic effect c. deterministic

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