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22 Cards in this Set
- Front
- Back
- 3rd side (hint)
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Why is it necessary to calibrate each batch of film used for dosimetry?
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There are variations in film emulsion,which directly effects the responsiveness and sensitivity of the film so each batch of film needs to be calibrated
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What is the element in the film emulsion that enables it to react to radiation?
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silver halide, when exposed to radiation causes darkening proportional to the radiation received. what is this degree of film darkening called?
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optical density
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What device measures optical density in film?
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densitometer
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What is the purpose of a control badge?
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measures background only to be subtracted from personnel badges
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Film is very energy dependent below ___ keV
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Film is very energy dependent below 200 keV
why is this important? |
this is the range where medical procedures are done
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What element of the film badge determines the type of radiaton the dosimeter is meant to monitor?
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The use of filters, aluminum, copper, cadmium, tin, silver or lead.
Their different attenuation properties show different optical densities on the film showing level of exposure |
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List the 6 advantages of using film dosimeters
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1. permanent record
2. wide range of measurement 10mrads to 1800 rads of gamma rays 3. sensitivity to high energy beta >400 keV 4. type and level of energy can be determined 5. mechanically rugged, light, versatile 6. can be used for thermal neutron dosimetry list 4 disadvantages |
1. long time between exposure and interpretation
2. inaccurate exposure sometimes recorded 3. sensitive to heat, cannot be punctured 4. insensitive to low energy beta |
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What part of NRC regulates personnel exposure?
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CFR part 20
Who are required to wear monitors? |
any one who may in one year likely to receive doseage in excess of 10% of occupational dose limits or anyone entering a high radiation area
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What are the 3 areas monitored for dose equivalents and what units are they in?
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Deep
Eye Shallow mRem and/or mSieverts |
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What is deep dose equivalent?
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tissue depth of 1cm, applies to external whole body exposure
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What is eye dose equivalent?
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tissue depth of 0.3cm, applies to lens of eye
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What is shallow dose equivalent?
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tissue depth of 0.007cm over 1sqcm, applies to exposure of skin or extremity
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Ring badge readings are reported as a _______ dose if due to gamma rays
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Ring badge readings are reported as a shallow dose if due to gamma rays
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Localization of a Meckles Divticulum can be accomplished by which of the following radiopharmaceuticals?
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B Tc99m pertechnetate
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17
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Which of the following is the initial positioning for visulation for Gastrointestinal bleeding for RBC's
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C lower border of liver and spleen at top of field of view
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18
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Which of the following Tc99m labeled agents is the preferred tracer for demonstrating intermediate GI Bleed?
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C. Red blood cells
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19
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Patient prep for GI bleed is:
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no prep required
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20
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Tc99m sc is an ideal choice for imaging active bleeds because:
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b minimizing background level activity
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If a bleeding patient is actively bleeding the site of the bleed will visualize as a:
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c. focal area of abmornal tracer accumulation
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For a diagnosis of bleeding to be made the scan must show the:
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c activity moving antegrade or retrograde along the bowel lumen
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A neg bleeding scan is an indication of:
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b. no active bleeding at time of scan
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Acquisition of a Meckle's Diverticulum utilizes Tc99m pertechnetate concentrations in:
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a. the gastric mucosa
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