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24 Cards in this Set
- Front
- Back
A device that includes a photosensitive array and small pixels that convert light into electrical charges is known as a _____ transistor.
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Thin-flim
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A device that acts like a switch to send electrical charges to the image processor in a direct conversion flat-panel detector is known as a ____ trasnsistor
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Field-effect
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In a flat-panel detector, specialized silicon integrated circuits control ____.
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Line scanning sequence
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Flat-panel detectors that use indirect conversion technology convert _______.
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X-rays to visible light
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Indirect conversion in flat-panel detectors is a ____ -step process
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Two
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The type of flat-panel detector that uses thin films of silicon integrated with arrays of photodiodes is known as a ______.
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Amorphous silicon detector
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Cesium iodide detectors use _____.
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rare-earth scintillators
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In cesium iodide detectors, _____.
-There is a great deal of light spread -Crystalline needles block light from the detector -Light hitting the photodiode reduces the charge -light spread causes resolution to decrease |
Light hitting the photodiode reduces the charge
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A device that acts like a camera in an indirect conversion detector known as a ______.
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Charged couple device
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The indirect conversion detector system that requires optical coupling and image size reduction is known as _____.
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Charge-coupled device
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When specialized pixels in a complementary metal oxide silicon system are struck with x-ray photons, _____.
-The x-ray photons are converted into light -light photons are stored in capacitors -light photons are converted into electrical charges -all of the above |
all of the above
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Detective quantum efficiency is a measurement of the ____.
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Percentage of x-rays absorbed
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Digital imaging systems have _____ DQE latitude than screen/film systems
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Wider
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Which of the following have the greatest DQE?
-Film/screen systems -cassette-based radiography -cassette-less radiography -all have the same DQE |
cassette-less radiography
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The number and size of pixels available are determined by matrix size. This is known as the ____ factor.
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Fill
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Detectors must be _____.
-Smaller than the area to be imaged -As large as possible -Large enough to cover the area to be imaged -the same size for every part to be imaged |
Large enough to cover the area to be imaged
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Which of the following has the greatest spatial resolution?
-Film/screen -indirect digital detectors -direct digital detectors -spatial resolution is the same for all systems |
Film/screen
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Excessive digital processing can lead to _____.
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High noise
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Pixel pitch refers to the _____
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Space between pixels
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The larger the matrix, the _____
-larger the image -more storage space needed -both A and B -neither A or B |
both A and B
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True or False: More pixels always mean better resolution
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False
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Which of the following will increase resolution?
-small matrix, large pixels -small matrix, small pixels -large matrix, large pixels -large matrix, small pixels |
large matrix, small pixels
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The main factor that limits quality in cassette-less image acquisition is _____.
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Noise
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True or False: Electronic memory artifact occurs when exposures are taken in too rapid a sequence.
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True
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