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12 Cards in this Set
- Front
- Back
- 3rd side (hint)
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What are the 2 image quality geometric properties?
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1. Recorded Detail
2. Distortion |
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What are other names for recorded detail?
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definition
sharpness spatial resolution detail |
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What is the unit of resolution when testing recorded detail on an image?
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Line pairs per millimeter
what is the lowest we can see? |
5 lp/mm
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What is another name for "unsharpness" ?
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penumbra
What is another name for "sharpness"? |
umbra
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Name the 3 factors that cause penumbra?
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1. motion
2. materials used (cassettes, film, etc) 3. geometry (focal spot size, OID, SID, SOD) |
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What is the best way to eliminate motion?
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Voluntary - through communication and/or immobilization
Involuntary - short exposure times |
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Is film choice a big factor in recorded detail? why or why not?
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No, no matter what film speed we use it can give us more detail than we can see anyway
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What effect does intensifying screens have on recorded detail?
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The faster the screen the less recorded detail, so the greater and bigger the phosphors the more light it emits and the more recorded detail is lost
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What is the type of phosphor is used today because they are so efficient?
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rare earth
they are so efficient you can use less and increase recorded detail |
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What are the 3 factors geometrically that we can control that effect recorded detail?
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1. Focal spot size
2. SID 3. OID |
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What is the major geometric factor in recorded detail that we can control?
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OID - keep the body part as close to the IR as possible to get the best recorded detail
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When we increase the SID we have ___________ recorded detail?
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When we increase the SID we have better recorded detail?
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