How many shades is bi-stable composed of? and what are they?
two shades, black and white
considering contrast does bi-stable have low or high contrast and what causes it?
high contrast and wide dynamic range
what is dynamic range?
the many shades of gray the image can display
considering display controls, what consist of contrast?
the range of shades of gray that are displayed
what component does analog and digital belong to?
the scan converter
what are analog numbers?
what we use everyday (real world)
ex:1, 2, 3, 4… someone weighs 158lbs
what are digital numbers
related to computers, several digital numbering systems
what is the most common digital system?
binary numbering system
in binary, 001 is 1 in our numbering system, 010 is 2, 100 is 4
what is an advantage of using analog scan converter?
very high spatial resolution due to nearly infinite levels of electrical charge that can be stored
what are the disadvantages of using analog scan converter?
not stable, image fade, image flicker, instability, deterioration
what is the significance to digital scan converter?
the electron charges are converted into digital binary numbers
what are the advantages of using digital scan converters?
uniformity, stability, durability, speed, and accuracy
what are the digital scan converter elements?
pixel- picture element: the smallest “building block” of a digital picture
bit- binary digit: a value of either 0 or 1
when considering presentation what is the rule for pixels?
the more pixels, the more accurate presentation
what pixel size and density will give you the best spatial resolution?
smaller pixels, higher pixel density
what is considered in preprocess?
synchronizer, pulser, beam former, transducer, receiver (amplification, compensation, compression, and reject)
what is considered in scan converter?
converts analog to digital, once converted into digital everything is considered post-processed
what is considered post processing?
things that are digitally stored, displayed, and or archived
what will give you the worse spatial resolution when considering pixel size and density?
the larger the pixel size and the lower the pixel density
(few pixels per area)
what is considered a Byte?
a group of 8 bits
what is considered a word?
computer memory consisting of 2 bytes or 16 bits
what is the rule for pixel and bits relationship?
the more bits per pixel, the more shades of gray that can be processed and displayed
how do you calculate the number of shades of gray?
multiply 2 x’s itself by the # of bits
“2^n”
what are the ways of manipulating data?
pre-processing and post-processing
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Doppler44
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Optimizing doppler images22
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Imaging processing & display53
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Doppler shift*15
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Inspiration vs Expiration venous blood flow6
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Apply doppler48
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Lateral resolution*11
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Coded excitation*5
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Wall filter8
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Ergonomics6
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Dynamic range8
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Temporal resolution*16
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Artifacts25
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Mock 466
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Mock 363
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Mock 236
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Pulse repetition frequency*15
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Duty factor *7
