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27 Cards in this Set
- Front
- Back
- 3rd side (hint)
Digital receptor exposure is __________ to the selected mAs. |
Directly proportional |
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Digital receptor exposure is __________ the selected SID. |
Inversely proportional to the square of |
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In CR, what is used to express an acceptable exposure level to the PSP? |
The recommended exposure range is dependent on equipment type S# EI Value lgM# |
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What is the term used to describe the numeric value representative of the exposure the IR receives in digital radiography? |
Exposure indicator (EI) |
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What should the radiographer use as a guide to evaluate a CR image and determine if it has been optimally exposed? |
The exposure indicator should indicate values within the recommended range |
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From this list of factors, select the ones that have an effect on digital image contrast/grayscale: pixel bit depth, window width, window level, matrix size, pixel density, LUT. |
Pixel bit depth Window width LUT |
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From this list of factors, select the ones that have an effect on digital image brightness: pixel bit depth, window width, window level, matrix size, pixel density. |
Window level |
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From this list of factors, select the ones that have an effect on digital image resolution: pixel density, window level, pixel pitch, matrix size, window width. |
Pixel density Pixel pitch Matrix size |
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What is the exposure indicator in DR systems? |
DAP (dose-area product) |
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Where is the location of the DAP meter used in DR? |
At the collimator |
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What are the two types of distortion? |
Size and shape |
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What influences shape distortion? |
Tube, part, and IR alignment |
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What influences size distortion? |
OID and SID |
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What kind of patient information can be made part of the recorded image? |
Patient name/MRN Date Institution Side marker Patient position Time of study |
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Select the conditions that are likely to require an increase in exposure: acites, multiple myeloma, pleural effusion, congestive heart failure. |
Acites Pleural effusion Congestive heart failure |
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Select the conditions that are likely to require a decrease in exposure: emphysema, bowel obstruction, hydrocephalus, edema. |
Bowel obstruction Emphysema |
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What change in exposure is required when using iodine or barium contrast agents? |
Increase |
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What causes an aliasing artifact in digital imaging? |
If a grid used in CR has a frequency similar to the CR processor's scan frequency |
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When might background radiation artifacts occur in CR Imaging? |
When using an IP that has not been used or erased for 48 hours or more |
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The aliasing artifact, occasionally seen in digital imaging, is sometimes called __________. |
Moiré effect |
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What does the abbreviation MTF represent? |
Modulation transfer function |
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What is the best way to express digital detector image resolution? |
MTF |
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What does mAs control/regulate in digital imaging? |
Patient dose Receptor exposure Quantity of image-forming radiation |
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How will the resulting image appear if there are too few x-ray photons reaching the digital image receptor? |
Quantum mottle |
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What do exposure indicators indicate in digital imaging? |
The acceptable range of exposure |
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Digital Imaging systems are __________ sensitive to scattered radiation than film emulsion. |
More |
More or less |
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__________ collimation should always be used with digital systems because excessive scatter causes __________ errors. |
Close Histogram analysis |
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