Digital Imaging Foundations #1 Flashcards
Digital imaging receptors require MORE or LESS radiation than film to produce an image?
Less radiation
Which Solid state Detector is considered more expensive? CCD or CMOS?
CCD
Which Solid State Detector has less digital noise? CCD or CMOS?
CCD
T/F: the pixels on a digital radiographical images are organized in a matrix
True
What is an example of indirect digital imaging?
Photostimulable Phospor (PSP) Technology
What is the active area?
The region of the sensor that is capable of capturing an image
What are the larger matrix details?
- Smaller pixel size
- Able to enlarge (magnify) more of the images
- Larger file size
What is the definition of bit depth of digital radiographic images?
Maximum number of grey shades that an image can present
Direct vs indirect digital imaging
Direct: Solid-state sensors
Indirect: Photostimulable phosphor (PSP) technology
T/F: Analog has an infinite set of possible values?
True
What is pixel matrix?
A matrix that has a set of rows and columns.
How can you differentiate composites/amalgam from enamel on a radiograph?
Composite or amalgam is denser then enamel, so it should look more opaque than enamel.
Air looks (radiolucent/radiopaque) on a radiograph.
radiolucent
The maxillary sinus is filled with ______ and is _______ in the radiograph.
air, radiolucent
What sensor does ULSD use?
RVG 6200 (Carestream) sensors
What are the disadvantages to using digital radiography?
initial cost is higher and the technology is always evolving - can be obsolete soon
Which natural part of the tooth will have the most interaction with photoelectric effect?
Enamel
T/F: analog data must have a defined set of possible values
False
this is the case for Digital imaging, however
In an 8-bit image, which value is given to pure black?
a. 255
b. 250
c. 0
d. 50
c. 0
The larger the pixel matrix, the __________ the pixel size
smaller
What does contrast resolution allow you to differentiate between?
different densities
Were x-rays discovered with film or digital images?
film
Both CCD and CMOS image sensors convert x-ray photons to _________ that gets read by the sensor.
light
Solid-state sensors are used for direct or indirect digital imaging?
Direct digital imaging
True or False:
One disadvantage of digital radiography is that it requires a higher radiation dose.
False. Advantages of digital radiography include lower radiation doses and elimination of chemical processing.
What is sampling in analog-digital conversion?
Grouping a range of analog values together
Which of the following best differentiates digital from analog imaging?
expressed in discrete units
infinite set of possible values
contains a lead foil backing
expressed in discrete units (pixels)
How does increased sampling impact analog signal?
better representation of signal / higher bit depth
For film imaging, where are silver crystals found?
In the emulsion
What is the difference between sampling and quantization in regards to analog-digital conversion?
Sampling is grouping a range of values together
Quantization is assigning a single value to each sample
What is the one of the differences in film and digital imaging?
Film imaging uses silver crystals while digital imaging uses pixels
