digital imaging Flashcards
1
Q
basic concepts of digital imaging
A
- used to record radiographic images
- no film or processing chemistry is used
- uses an electronic sensor and computerized imaging system that produces x-ray images almost instantly on a computer monitor
2
Q
terminology:
A
- analog image
- bit-depth image
- Charge-coupled device (CCD)
- Digital imaging
- Digital image
- Digital subtraction
- Digitize
- Direct digital imaging
- Indirect digital imaging
- Line pairs/millimeter (lp/mm)
- Pixel
- Sensor
- Storage phosphor imaging
3
Q
brief explanation of why we use digital imaging
A
- to generate images that can be used in the diagnosis and assessment of dental disease
4
Q
purpose and use
A
- to detect lesions, disease, and conditions of the teeth and surrounding structures
- to confirm or classify suspected disease
- to provide information during dental procedures
- to evaluate growth and development
- to illustrate changes secondary to caries, periodontal disease, or trauma
- to document the condition of a patient at a specific point in time
- to localize lesions or foreign objects
- to aid in the development of a clinical treatment plan
5
Q
fundamentals of digital imaging
A
- a method of capturing a radiographic image using a decors, breaking it into electronic pieces, and presenting and storing the image using a computer
- the term image is sued to describe the pictures that are produces instead of radiographs
- a sensor is placed inside the mouth
- the electronic signal is digitized
6
Q
radiation exposure in digital imaging
A
- the typical sensor is more sensitive to x-rays than conventional film. requires less x-radiation exposure
- exposure times are 50%-90% less than that required for conventional radiography because the sensor is more sensitive to x-rays than conventional film
- ex. conventional intraoral film, which takes 0.5 seconds would take 0.05 seconds to produce and image for digital radiography
7
Q
equipment for digital imaging
A
- x-ray unit
- sensor: charged couple device (CCD), complementary metal oxide semiconductor/active pixel sensor, charge injection device
- computer
8
Q
x-radiation source
A
- most digital radiography systems use a conventional dental x-ray unit as the x-radiation source (it is compatible with digital imaging system)
- the x-ray unit timer mist be adapter to allow exposure times in a time Frame of 1/100 of a second
- unit can still be used for conventional radiography
9
Q
intraoral sensor
A
- a small detector that is placed in the mouth of the patient and used to capture the radiographic image
- wired: the imaging sensor is linked by a fixer optic cable to a computer (8-35 ft in length)
- wireless: the imaging sensor is not linked by a cable
10
Q
what size dimensions are intraoral sensors made?
A
- most sensors produced in similar dimension to size 0,1,2 and 4 intraoral films
11
Q
most popular types of direct sensor technologies
A
- charge-coupled device (CCD)
- complementary metal oxide semiconductor/active pixel sensor
12
Q
what is a charged-coupled device (CCD)?
A
- the most common image receptor used in dental digital imaging
- a solid-state detector that contains a silicon chip with an electronic circuit embedded in it
- the electrons that make up the silicon CCD can be visualized as being divided into an arrangement of blocks or picture elements known as pixels
- the x-ray photons that come into contact with the CCD cause electrons to be released from the silicon and produce a corresponding electronic charge
- each pixel arrangement, or electron potential well, contains an electronic charge proportional to the number of electrons that reacted within the well
- each electronic well corresponds to a specific area on the linked computer screen
13
Q
what is a pixel?
A
a small box or ‘well’ into which the electrons produced by the x-ray exposure are deposited
14
Q
what is a complementary metal oxide semiconductor/active pixel sensor (CMOS/APS)?
A
- one manufacturer uses a CMOS/APS sensor instead of a CCD
- the tip is less expensive to produce and offers greater durability than the CCD
15
Q
what does the computer do?
A
- used to store the incoming electronic signal; converts the electronic signal from the sensor into a shade of gray that is viewed on the computer monitor
- the computer digitizes, processes and stores information received from the sensor; an image is recorded on a computer monitor in 0.5 to 120 seconds
- image may be permanently stored in computer, printed or transmitted electronically to insurance companies or referring dental specialties
- has split screen and magnification capability
