9/3: Sensors & Digital Imaging Flashcards
- How many dental offices use digital radiography?
90%
- What are the different intraoral film sizes?
a. 0
b. 1
c. 2
d. 4
- Is there a size 3 intraoral film?
a. No
- What intraoral film sizes do what?
a. Size 0,1,2 = PA or BW
b. Size 4 = Occlusal
- Size 0 is for
a. Pediatric
- Size 1 is for
a. PA, pediatric
- Size 2 is for
a. Standard
- What is the composition for film?
a. Supercoat = thin layer of hard plastic
b. Emulsion
c. Adhesive
d. Base
- Emulsion is comprised of
a. Gel and Ag = halide crystal
- The base of the film is comprised of
a. Plastic
- In film processing, the chemicals used to form elemental Ag are from
a. Silver halide salt
- Chemical changes are what dependent?
a. Time
b. Temperature
c. Concentration
- Film has to be _____ processed
a. Manually
- What x-ray technique needs to be replenished when chemicals get diluted?
a. Film
- This is a table with columns and rows that are assigned a number value for each pixel that determines a gray intensity
a. Digital film
- Pixel is derived from the words
a. PEL (picture element)
- Pixels are
a. Electrified
- This is the smallest portion of a sensor, image, or display that is capable of being recorded and then printed/displayed
a. Pixel
- Does each pixel have a pre-exposure electrical charge?
Yes
- What do x-ray photons do to the pixels?
a. Change their electrical charge
- The thicker/denser the body part adjacent the sensor, the ___ the x–photons can affect the electrical charge
Less
- What are the different types of dental digital radiography?
a. Historic (indirect)
b. Indirect (semidirect)
c. Direct
- What kind of digital radiographs are historic?
a. Flatbed scanner
b. Slide scanner
c. Digital cameras
- What kind of digital radiographs are indirect?
PSP
- What kind of digital radiographs do we use in school?
a. Direct
- What kind of digital radiographs are direct?
a. Charge-coupled device
b. Complementary metal oxide semiconductor
- What is a problem with indirect digital radiography?
a. Loss or alliteration of information due to partial volume averaging
- When was the 1st film-like sensor introduced?
a. 1994
- What do you need to process semidirect radiographs like PSP?
a. Laser scanner
- What is a PSP plate coated with?
a. Crystalline (halide emulsion)
- What are the principles of PSP detectors?
a. X-ray
b. Psp plate coated with crystalline
c. Scanned with red laser
d. Emits fluorescent light
e. Intensified by a photomultiplier tube
f. Light intensity converted to digital data
g. Exposed to strong light to erase residual
h. Reuse
- What barrier do you need to use for PSP plates?
a. Barrier envelopes
b. Plate transfer box
- What do you ONLY need for a CCD?
a. analog-to-digital converter
- Are direct sensors similar in size to film and PSP?
Yes
- What does the Cesium scintillator operate?
a. Solid state sensor
- CCD/CMOS sensors have what 2 components?
a. External size
b. Internal active area
- The internal active area is the portion of the sensor that does what?
a. Produces an image
- Each pixel is characterized by what 2 things?
a. Location
b. Intensity
- Sensor thickness sweet spot is what?
a. 4-6mm
- What is the active ingredient in CCD?
a. Silicon
- Does CCD or CMOS need additional power to convert photon energy to an electronic digital signal?
a. CCD
- What are the principles of CCDs?
X-ray → scintillating material → light photons → silicon → electrons deposited in electron wells → transferred in a sequential manner (charge-coupling) → read out amplifier → images on monitor
- In a CCD you have a charge-coupled device sensor that does what conversions?
a. Photon to electron conversion
b. Electron to voltage conversion
- When comparing CCD and CMOS, what is true about CMOS?
a. Faster processing
b. Requires less power
c. Better image quality
- When comparing CCD and CMOS, what is true about CCD?
a. Less radiation
- What are the principles of CMOS?
a. X-ray → scintillating material → light photons → silicon → electrons deposited in electron wells and converted to voltage in each pixel → smoother signal digitization → software processing → images on monitor
- Does CCD or CMOS require less power?
a. CMOS
- 2^(bit) =
a. Number of shades of gray
- This is the number of colors or gray shades that a pixel is able to show
a. Bit depth
- Why is digital imaging appealing?
a. Less radiation
b. Lower cost
c. Environmentally friendly
