ORAL RADIOLOGY |IMAGE ACQUISITION | RADIATION SAFETY
|DIAGNOSTIC INTERPRETATION
OFFICIAL TECHNICIAN / DENTAL ASSISTANT PRACTICE TEST
PAPER
CLINICAL RADIOGRAPHY SKILLS & SAFETY COMPETENCY REVIEW
What's indirect action film
Extra oral with intensifying screen & cassette . sensitive to light photons
Why is direct action film used for intra oral
For excellent image quality
black paper is used on either side of the film to protect the film from...?
Light
damage by fingers
saliva that may leak into film packet
Why is a thin sheet of lead foil placed behind the film?
To stop residual radiation going further into pt tissues
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, 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
too dark/blacken
Decreasing the mA will make the image
Too white / light
What % of energy is conducted as heat and X-rays ?
Heat -99%
Xrays - 1%
What is the recommended FSD
200mm or 20cm
What are the dose units used for radiography
Radiation absorbed dose
Equivalent dose
Effective dose
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