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17 Cards in this Set
- Front
- Back
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Line pairs Per Millimeter (lp/mm)
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measures the minimum size and space between objects that can be visualized on the final image.
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Missmatching film and screens often (blank) patinent dose.
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Increases
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Relative speed numbers are usually established at what kVp?
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70-80 kVp
80 kVp preferred |
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Line Spread Function (LSF)
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measures the ability of a film/screen system to accurately measure the boundaries of an image.
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Modulation Transfer Function (MTF)
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Provides the best measurement of the resolving ability of a film/screen combination.
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Formula for converting mAs from one relative speed to another:
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mAs1 / mAs2 = RS2 / RS1
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Relative speed is usually established at what kVp?
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70-80 kVp
80 kVp preferred |
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Latitude has a (blank) relationship with contrast.
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Direct
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Detail film/screen combinations are used for?
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Skeletal extremity radiography
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High-speed rare-earth film/screen combinations are used on?
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Gastrointestinal and Urologic radiography
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Faster calcium tungstate or slower rare-earth film/screen combinations are used on?
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Abdominal radiography. Low subject contrast, which requires reducing quantum mottle noise.
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Calcium tungstate film/screen combinations are used for?
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High kVp (> 100 kVp) Chest radiography.
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higher-speed film/screen combinations are used on?
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Pediatric radiography, due to large portions of the body included in the primary beam, also motion is a key factor.
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What are the three methods of measuring resolution?
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-Line Pairs per millimeter(lp/mm)
-Line Spread Function -Modulation Transfer Function |
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How is film/screen contrast related to latitude?
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Film/screen contrast is directly related to latitude. (Narrow latitude film/screen systems exhibit high contrast.
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Rare-earth film/screen combinations are used in what type of radiography.
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Angiography - decreased patient dose while maintaining resolution.
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Four important characteristics of film/screen combinations?
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Speed, resolution, contrast, latitude
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