safety and protection

Question 1

3 guiding principles of radiation protection

Answer 1

1. principle of justification - means cannot take for screening purposes, need to back up radiographs w clinical findings
2. Principle of optimisation (ALARA) - due to LNT, doses to pt needs to be as low as reasonably achievable
3. dose limitation to ppl w occupational risk and general public

Question 2

10 ways to reduce radiation exposure to patients–> ALARA

Answer 2

1. patient selection criteria: clinical examination, caries risk, history, past radiographs, dental and general health needs
2. filtration: reduce low energy photons that’s absorbed by patient and dont contribute information to image
3. rectangular collimation: rectangular collimation reduce radiation dose by 5 fold compared to circular collumation
4. mAs (exposure time): too high, dark image while too low grainy/noisy image
5. kVp (operating potential): detect caries <70kVp to increase contrast for lesser shades of grey, perio 70-90kVp to decrease contrast for more shades of grey
6. technique chart:
7. lead apron vs thyroid collar: lead apron in DPT, thyroid collar in PA and BW
8. focal source to skin distance: fsd increase, photon beam more paralle, 30% less tissue exposed & prevent magnification
9. film vs digital - film need more radiation dose than digital –> faster the speed of film, lesser radiation dose –> fastest to slowest speed of film = F, E, D
10. film and sensor holders - lesser retakes, better alignment

Question 3

3 ways to reduce radiation exposure to workers w occupational risk and general public –> dose limitation

Answer 3

1. distance
2. time
3. shield (lead glass and door)