What's direct action film? correct answers Intra oral film. Only sensitive to xray photons
What's indirect action film correct answers Extra oral with intensifying screen & cassette .
sensitive to light photons
Why is direct action film used for intra oral correct answers For excellent image quality
black paper is used on either side of the film to protect the film from...? correct answers Light
damage by fingers
saliva that may leak into film packet
Why is a thin sheet of lead foil placed behind the film? correct answers To stop residual radiation
going further into pt tissues
To stop secondary radiation from scattering back onto film and degrading the image
If film was placed wrong way in pts mouth the lead foil would show on radiograph making the
fault easily identified
Increasing the Ma will make the image correct answers too dark/blacken
Decreasing the mA will make the image correct answers Too white / light
What % of energy is conducted as heat and X-rays ? correct answers Heat -99%
Xrays - 1%
What is the recommended FSD correct answers 200mm or 20cm
What are the dose units used for radiography correct answers Radiation absorbed dose
Equivalent dose
Effective dose
What dose is the actual dose patients are interested in? correct answers Effective dose
What is the effective dose from one intra oral radiograph ? correct answers 0.022&0.0003
millisievert msv
What are the steps involved for effective dose ? correct answers Radiation absorbed dose x
weighting factor = equivalent dose
Equivalent dose x tissue weighting factor = effective dose
Add all effective doses added up for final effective dose
Definition of paralleling technique correct answers Image receptor parallel to the long axis of the
tooth and X-ray beam at right angles to tooth and image receptor