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23 Cards in this Set
- Front
- Back
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What is greatest source of radiation for humans?
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Natural radiation
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What is the greatest source of natural radiation?
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Internal - inhaled/ingested
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What is the greatest source of internal radiation?
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Radon
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What is "Negligible Individual Dose" as it relates to radiation? (define, #)
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The does below which it is not effective to try and reduce. 50 mSv/wholebody/year
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0.142 mSv for Round
0.06 for Rectangle 0.01 for panoramic |
Mean active bone marrow dose from full mouth survey
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What's the first step in limitign exposure/dose for patients?
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Selection - picking those which a scan would benefit treatment
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E and D speeds are examples of what?
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Intraoral Image receptors
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Gadolinium/Lanthanum are 2 examples of what?
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Materials of Intensifying screens
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Above 50 kVp, what is the proper distance for Focal spot to Film?
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8 inches - 7 from skin, 1 from skin to film
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what is the maximum diameter of a cirlce for the area exposed to radiation in dentistry?
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2.75 inches for 50kVp+
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What are the 2 ways to alter the amount of radiation received by the patient in terms of EQUIP. OPERATION?
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kV, mA alterations
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10 mR/week - What is this significant for
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others in an office should receive no more than this
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Where should a professional be located in relation to the x-ray beam?
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between 90 and 45 degrees to it, 6 feet away
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What are the 2 components of X-ray Film?
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Base and Emulsion
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What are the 2 components of Emulsion of x-ray film?
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The Vehicle Matrix and the Silver halid grains
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What is the Emulsion's purpose in x-ray film?
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it is the part that is sensitive to x-rays
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What is the purpose of Intensifying screens?
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Image receptor becomes more sensitive to x-rays
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What are the 3 parts of an Intensifying screen?
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the Base, the Phosphor layer, and the Coat (plastic)
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What is the term for the # of photons reaching the film?
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EXPOSURE
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What is the relationship of kVp and contrast?
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Lower kVp = Raise contrast
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What is the term for the amount of radiation required to produce image of STANDARD DENSITY?
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radiographic speed
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what is MOTTLE?
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Graininess of film, caused by high temperatures
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What are the 2 types/ causes of Mottle?
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Quantum - fluctuation in #photons/beam
Screen Structure - caused by screen phosphors |
