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27 Cards in this Set
- Front
- Back
What is digital radiography? |
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What is the purpose and use of digital imaging? |
To generate images that can be used in the diagnoses and assessment of dental disease:
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What are the methods of Digital imaging? |
- Existing radiographs can be converted to digital by scanning or photographing with a digital camera (also sometimes termed "indirect imaging) - Quality is compromised compared to direct digital |
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What is direct digital imaging? What are the two sensors CCD and CMOS? what is the difference? |
- CCD or Charge-Coupled Device - CMOS or Complementary metal oxide semiconductor Difference between the two is the makeup of the chip in the sensor |
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What are the sensors? |
made up of a grid of x-ray or light sensitive cells each cells |
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What do the cells of a sensor represent? |
a pixel in the final image |
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what is a pixal the digital equivalent to? |
Aranged (not random) - silver halide crystals (sensitivity specs) |
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What are the pixels for? |
for electrons produced by the x-ray to be depositied into |
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What do the x-rays do to the sensor? |
The x-ray strikes the sensor, the pixels are excited and the gray value is determined depending on the number of x-rays striking each pixel |
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What is done with the information gathered by the sensor? |
it is transmitted to the computer where the image is constructed |
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What equimpment is needed for direct digital? |
- some are wired and some are wireless - wireless sensors are usually thicker and can be sensitive to other signals in the area
- Can record image and send to monitor in 0.5-120 seconds
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What is indirect digital imaging and what does it use? |
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What equipment is needed for indirect digital? |
- have a greater variety in size than direct
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Why is it known as indirect digital imaging |
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What are the computer requirements? |
- images can be transferred wirelessly to a nearby computer for storage |
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What are some cool features/capabilities of the software? |
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How does the quality of digital images vary? |
- The more pixels, the higher the resolution and the sharper the image
- Great spatial resolution = sharper image
- Can be enhanced with digital systems and show more subtle changes to the structure than can be seen with a standard radiographic film |
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What is the greatest reduction in exposure level? |
when going from a D-speed to digital |
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which sensors are more sensitive and require less exposure time? |
CCD and CMOS |
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When may exposure not be reduced |
When comparing to extraoral film (pano) |
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How do you prepare the sensor? |
Each sensor is sealed and waterproofed - the sensor must be covered with a disposable barrier because it can not be starilized |
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How do you place the sensor? |
It is held in the mouth by bite-block attachments or devices that aim the beam and sensor accurately (similar to the RINNs) - the paralleling technique is the preferred exposure method |
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What are the advantages of digital imaging? |
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What is the downside to digital imaging? |
- ease of placing back in the mouth and exposing - perceived reduction in dosage - more exposures required due to size of sensor - rigidity of sensor can cause discomfort resulting in placement errors |
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What are disadvantages to digital imaging? |
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What is DICOM? |
Digital imaging and communications in medicine - standard to allow different digital systems to interface with eachother - recommended that digital systems meet/adopt this standard to improve communication between providers |
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What does the future hold? |
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