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27 Cards in this Set
- Front
- Back
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What controls quality and intensity of radiation?
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kV
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How is the amount of kV determined?
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by the thickness and composition of the material being inspected
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Low absorbing objects have what?
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low kV better contrast,but less latitude
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High absorbing objects have what?
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high kV less contrast, but better latitude
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High kV produces what?
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shorter wavelengths, greater penetration and less absorption of energy
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lowest kV produces what?
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better contrast and better sensitivity
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mA controls what?
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quantity and intensity
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total output is is proportional to what?
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to mA and time
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Geometrical set up is used to produce what?
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a radiographic image
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Geometrical relationships affect what?
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image sharpness and help control image distortion
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Geometric factors controls what?
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distortion, alignment of defects and clarity
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What are the five geometric factors?
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1) focal spot size(small as possible)
2) surface to film distance (SFD)(far as possible) 3) beam to film alignment(90degrees to film) 4) film to object distance(SOD) (close as possible to area of interest 5) object to film alignment |
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Image unsharpness is due to what?
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size of source and relative distance
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The distance over the edge of the part is known as?
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penumbral shadow of geometric unsharpness
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The penumbral shadow can be calculated using a what?
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nomogram
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Foe good definition/ detail the penumbral shadow(UG) should be what?
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.09mm or less
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Smaller grain size produces what?
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sharper image
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over development increases what?
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graininess
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increasing kV increases what?
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graininess
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The smallest discontinuity which can be detected is known as what?
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radiographic sensitivity
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Radiographic sensitivity is determined by what?
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contrast and definition
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The size of the grain in the film controls what?
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sensitivity
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Slower film and small grains produce what?
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better sensitivity
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fast film and large grains produce what?
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less sensitivity
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Contrast in a radiograph is the difference in the resultant density which is produced for a given change of X-ray absorption( visual contrast on the film) is known as what?
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radiographic contrast
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What factors control film contrast?
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1) type of film
2) development of film 3) density |
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what factors control object contrast?
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1) material contrast
2) thickness variation 3) quality radiation 4) scatter radiation |
