Radiation Protection

Card Set Information

Author:
Anonymous
ID:
302823
Filename:
Radiation Protection
Updated:
2015-05-16 21:16:22
Tags:
rad
Folders:

Description:
Minimizing patient exposure
Show Answers:

Home > Flashcards > Print Preview

The flashcards below were created by user Anonymous on FreezingBlue Flashcards. What would you like to do?


  1. If the exposure rate to an individual standing 4.0 m from a source of radiation is 10 mR/h, what will be the dose received after 20 minutes at a distance of 6 m from the source?




     
    22.5 mR 



     
    7.5 mR 



     
    4.44 mR 



     
    1.48 mR
    •  
    •  
    • 1.48 mR 
    • inverse-square law of radiation. The formula is 
    • Substituting known values:

    • Thus, x = 4.44 mR in 60 minutes and, therefore, 1.48 mR in 20 minutes. Distance has a profound effect on dose received and, therefore, is one of the cardinal rules of radiation protection. As distance from the source increases, dose received decreases.
  2. Moving the image intensifier closer to the patient during traditional fluoroscopy

    1. decreases the SID

    2. decreases patient dose

    3. improves image quality






     
    1 only 



     
    1 and 2 only 



     
    1 and 3 only 



     
    1, 2, and 3
    •  
    •  
    • 1, 2, and 3
  3. With milliamperes (mA) increased to maintain output intensity, how is the ESE affected as the source-to-skin distance (SSD) is increased?




     
    The ESE increases. 



     
    The ESE decreases. 



     
    The ESE remains unchanged. 



     
    ESE is unrelated to SSD.
    •  
    •  
    • The ESE decreases.
  4. Which of the following will increase patient dose during fluoroscopy?

    1. Decreasing the SSD

    2. Using 2.5 mm Al filtration

    3. Restricting tabletop intensity to less than 10 R/min






     
    1 only 



     
    1 and 2 only 



     
    2 and 3 only 



     
    1, 2, and 3
    •  
    •  
    • 1 only
  5. If a patient received 2000 mrad during a 10-minute fluoroscopic examination, what was the dose rate?




     
    0.02 rad/min 



     
    0.2 rad/min 



     
    2.0 rad/min 



     
    20 rad/min
    •  
    •  
    • 0.2 rad/min 
    • Two thousand mrad is equal to 2 rad. If 2 rad were delivered in 10 minutes, then the dose rate is 2 ÷ 10, or 0.2 rad/min.
  6. What quantity of radiation exposure to the reproductive organs is required to cause temporary infertility?




     
    100 rad 



     
    200 rad 



     
    300 rad 



     
    400 rad
    •  
    •  
    • 200 rad
  7. Which of the following is (are) associated with Compton scattering?















    1. High-energy incident photons
    2. Outer-shell electrons
    3. Characteristic radiation






     
    1 only 



     
    1 and 2 only 



     
    2 and 3 only 



     
    1, 2, and 3
    •  
    •  
    • 1 and 2 only
  8. Aluminum filtration has its greatest effect on




     
    low-energy x-ray photons 



     
    high-energy x-ray photons 



     
    low-energy scattered photons 



     
    high-energy scattered photons
    •  
    •  
    • low-energy x-ray photons
  9. Patient exposure can be minimized by using which of the following?















    1. Accurate positioning
    2. High-kV, low-mAs factors
    3. Rare earth screens






     
    1 only 



     
    1 and 2 only 



     
    1 and 3 only 



     
    1, 2, and 3
    •  
    •  
    • 1, 2, and 3
  10. If a patient received 1,400 mrad during a 7-minute fluoroscopic examination, what was the dose rate?




     
    200 rad/min 



     
    5 rad/min 



     
    2.0 rad/min 



     
    0.2 rad/min
    •  
    •  
    • 0.2 rad/min 
    • A measure 1,400 mrad is equal to 1.4 rad. If 1.4 rad were delivered in 7 minutes, then the dose rate would be 0.2 rad/min: 
  11. If a patient received 4,500 mrad during a 6-minute fluoroscopic examination, what was the dose rate?




     
    0.75 rad/min 



     
    2.7 rad/min 



     
    7.5 rad/min 



     
    27 rad/hr
    •  
    •  
    • 0.75 rad/min
    •  Since 4,500 mrad is equal to 4.5 rad, if 4.5 rad were delivered in 6 minutes, then the dose rate must be 0.75 rad/min: 
    • Thus, x = 0.75 rad/min.
  12. Which of the following most effectively minimizes radiation exposure to the patient?




     
    Small focal spot 



     
    Low-ratio grids 



     
    Increased SID 



     
    High-speed intensifying screens
    •  
    •  
    • High-speed intensifying screens
  13. An increase of 1.0 mm added aluminum filtration of the x-ray beam would have which of the following effects?

    1. Increase in average energy of the beam

    2. Increase in patient skin dose

    3. Increase in milliroentgen output






     
    1 only 



     
    1 and 2 only 



     
    2 and 3 only 



     
    1, 2, and 3
    •  
    •  
    • 1 only
  14. A fluoroscopic examination requires 3 minutes of exposure on time. If the exposure rate for the examination is 250 mR/hr, what is the approximate exposure for the three minute procedure?




     
    83.3 R 



     
    83.3 mR 



     
    12.5 R 



     
    12.5 mR
    •  
    •  
    • 12.5 mR 
    • If the exposure rate for the examination is 250 mR/hour (60 minutes), then a 3-minute examination would be proportionally less—as the equation below illustrates:
    • 60 x = 750 
    •      x = 12.5 mR, dose in 3 minutes
  15. Patient dose increases as fluoroscopic




     
    FOV increases 



     
    FOV decreases 



     
    FSS increases 



     
    FSS decreases
    •  
    •  
    • FOV decreases
  16. If a patient received 2000 mrad during a 10-minute fluoroscopic examination, what was the dose rate?




     
    0.2 rad/min 



     
    2.0 rad/min 



     
    5 rad/min 



     
    200 rad/min
    •  
    •  
    • 0.2 rad/min
  17. If the exposure rate to an individual standing 2.0 m from a source of radiation is 15 R/min, what will be the dose received after 2 minutes at a distance of 5 m from the source?




     
    1.2 R 



     
    2.4 R 



     
    4.8 R 



     
    9.6 R
    •  
    •  
    • 4.8 R 
    • 25 x = 60
    • x = 2.4 R/minute at 2 m = 4.8 R after 2 minutes
  18. If the entrance dose for a particular radiograph is 320 mR, the radiation exposure at 1 m from the patient will be approximately




     
    32 mR. 



     
    3.2 mR. 



     
    0.32 mR. 



     
    0.032 mR.
    •  
    •  
    • 0.32 mR.
    •  Therefore, if the entrance dose for this image is 320 mR, the intensity of radiation at 1 m from the patient is 0.1% of that, or 0.32 mR (0.001 × 320 = 0.32). 
  19. Which of the following result(s) from restriction of the x-ray beam?

    1. Less scattered radiation production

    2. Less patient hazard

    3. Less radiographic contrast






     
    1 only 



     
    1 and 2 only 



     
    2 and 3 only 



     
    1, 2, and 3
    •  
    •  
    • 1 and 2 only

    1. can pose a safety hazard to personnel

    2. can have a negative impact on image quality

    3. occurs with low-energy incident photons










     
    1 only 



     
    1 and 2 only 



     
    2 and 3 only 



     
    1, 2, and 3
    •  
    •  
    • 1 and 2 only
  20. If a patient received 0.9 rad during a 3-minute fluoroscopic examination, what was the dose rate?




     
    3 mrad/min 



     
    30 mrad/min 



     
    300 mrad/min 



     
    3,000 mrad/min
    •  
    •  
    • 300 mrad/min 
    • If 0.9 rad were delivered in 3 minutes, then the dose rate would be 0.9/3, or 0.3 rad/min. Three-tenths rad is equal to 300 mrad. 
  21. Which of the following will reduce patient dose during fluoroscopy?















    1. Decreasing the source-skin distance (SSD)
    2. Using 2.5 mm Al filtration
    3. Restricting tabletop intensity to less than 10 R/min






     
    1 only 



     
    1 and 2 only 



     
    2 and 3 only 



     
    1, 2, and 3
    •  
    •  
    • 2 and 3 only
  22. An increase in total filtration of the x-ray beam will increase




     
    patient skin dose 



     
    beam HVL 



     
    image contrast 



     
    milliroentgen (mR) output
    •  
    •  
    • beam HVL
  23. Guidelines for the use of protective shielding state that gonadal shielding should be used

    1. if the patient has reasonable reproductive potential

    2. when the gonads are within 5 cm of the collimated field

    3. when tight collimation is not possible






     
    1 only 



     
    1 and 2 only 



     
    1 and 3 only 



     
    2 and 3 only
    •  
    •  
    • 1 and 2 only

What would you like to do?

Home > Flashcards > Print Preview