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12 Cards in this Set
- Front
- Back
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To obtain a higher frame rate we must: |
1) have a shallow image 2) single focus 3) narrow sector 4) low line density |
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Lower frame rates are a result of: |
1) deeper imaging 2) multiple focal points 3) wide sector 4) high line density |
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What is contrast resolution? |
Ability to distinguish structures based on variations of brightness (restricted by bits per pixel ) |
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What is temporal resolution? |
Ability to distinguish dynamics/changes over time (limited by frame rate) |
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What factors effect temporal resolution? |
1) imaging depth 2) imaging frame or sector size 3) how many foci are being used 4) line density and packet size |
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What is line density? |
The number of scan lines in an ultrasound image ( a higher level provides better resolution but worse frame rate) |
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What 3 things determine frame rate? |
1) sound speed through a medium 2) depth of imaging 3) number of lines of sight |
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A scanning type that depicts the amplitude of returning echoes as a function of time along a single scan is called: |
A-mode (amplitude) |
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A scanning type that is a presentation of changing reflector position versus time is called: |
M-mode (motion) |
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A scanning mode where amplitude is mapped to a grey-scale level or brightness is called: |
B-mode (brightness) |
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What is detail resolution? |
A combination of axial and lateral resolution; dependant on transducer characteristics |
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A type of scanning that can be used to acquire an image of a specific slice at a particular depth is called: |
C-mode (constant) ( most similar to PW) |
