RADT 146 Grids exam with correct answers
Grid Objective - correct answer ✔minimizes the amount of scatter radiation
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coming from the patient before it reaches the IR
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Benefits of reducing scatter radiation - correct answer ✔improves radiographic
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contrast, and therefore detail
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Grid placement - correct answer ✔between patient and IR
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What happens has the primary beam passes thru the patient? - correct answer
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✔Photons are scattered in many different directions
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How does the grid work? - correct answer ✔Allows for straighter photons to
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pass thru to the IR, while photons not carrying useful information are absorbed
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What body parts are grids useful for? - correct answer ✔thicker body parts,
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>10cm (between knee and shoulders)
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Cross-Angle Limit - correct answer ✔3 degrees
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Focal Range - correct answer ✔Limited to plus/minus 4 inches (10cm)
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, Grid Use Effect on Patient Exposure - correct answer ✔Grid use increases
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patient exposure (higher technical factors must be used), however this is
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negligible.
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Grid Invented - correct answer ✔invented in 1913 by Gustave Bucky
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Radiolucent material used to separate thin lead strips - correct answer ✔Plastic,
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aluminum, fibrous material
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Grid Ratio - correct answer ✔describes the height of the lead strip to the
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distance between them
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Grid Frequency - correct answer ✔refers to the number of lead strips per
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centimeter
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Greater grid frequency means - correct answer ✔thinner lead strips
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- elimination of grid lines
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- but higher energy scatter can penetrate thin strips
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Grids have to be parallel to what? - correct answer ✔x-ray tube and image
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receptor
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Higher Grid Efficiency caused by - correct answer ✔- high selectivity
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- high grid ratio
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- low frequency
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Grid Objective - correct answer ✔minimizes the amount of scatter radiation
/ / / / / / / / / /
coming from the patient before it reaches the IR
/ / / / / / / / /
Benefits of reducing scatter radiation - correct answer ✔improves radiographic
/ / / / / / / / /
contrast, and therefore detail
/ / / /
Grid placement - correct answer ✔between patient and IR
/ / / / / / / /
What happens has the primary beam passes thru the patient? - correct answer
/ / / / / / / / / / / /
✔Photons are scattered in many different directions
/ / / / / / /
How does the grid work? - correct answer ✔Allows for straighter photons to
/ / / / / / / / / / / /
pass thru to the IR, while photons not carrying useful information are absorbed
/ / / / / / / / / / / / /
What body parts are grids useful for? - correct answer ✔thicker body parts,
/ / / / / / / / / / / /
>10cm (between knee and shoulders)
/ / / / /
Cross-Angle Limit - correct answer ✔3 degrees
/ / / / / /
Focal Range - correct answer ✔Limited to plus/minus 4 inches (10cm)
/ / / / / / / / / /
, Grid Use Effect on Patient Exposure - correct answer ✔Grid use increases
/ / / / / / / / / / /
patient exposure (higher technical factors must be used), however this is
/ / / / / / / / / / /
negligible.
/
Grid Invented - correct answer ✔invented in 1913 by Gustave Bucky
/ / / / / / / / / /
Radiolucent material used to separate thin lead strips - correct answer ✔Plastic,
/ / / / / / / / / / /
aluminum, fibrous material
/ / /
Grid Ratio - correct answer ✔describes the height of the lead strip to the
/ / / / / / / / / / / / /
distance between them
/ / /
Grid Frequency - correct answer ✔refers to the number of lead strips per
/ / / / / / / / / / / /
centimeter
/
Greater grid frequency means - correct answer ✔thinner lead strips
/ / / / / / / / /
- elimination of grid lines
/ / / /
- but higher energy scatter can penetrate thin strips
/ / / / / / / /
Grids have to be parallel to what? - correct answer ✔x-ray tube and image
/ / / / / / / / / / / / /
receptor
/
Higher Grid Efficiency caused by - correct answer ✔- high selectivity
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- high grid ratio
/ / /
- low frequency
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