Digital Imaging

Question 1

2 types of imaging

Answer 1

Analog and digital

Question 2

Analog image

Answer 2

photograph, film based, continuous pattern of gray

Question 3

Digital Image

Answer 3

Exist only as numbers in a computer file

Question 4

ADC (Analog to digital converter)

Answer 4

Assigns analog data numerical values “units of information” or pixels

Question 5

Image Matrix

Answer 5

Each square in the grid represents a pixel; the more pixels in the image, the better the resolution and clarity.

Question 6

Line Pairs

Answer 6

The largest number of paired lines visible in a 1mm space of the image.

Question 7

Older sensors

Answer 7

70u size pixels

Question 8

modern sensors

Answer 8

25u size pixels

Question 9

Gray scale resolution

Answer 9

Total number of shades of gray visible in an image

Question 10

Advantages to Digital Imaging

Answer 10

Eliminates need for film and darkroom; Increased speed of viewing; Increased efficiency, P.E. tool; < decreases radiation; eco-friendly

Question 11

Disadvantages of Digital Imaging

Answer 11

Biggest disadvantage is cost (6-20K), requires computer technology, requires printer for hard copies of images

Question 12

2 types of digital imaging

Answer 12

Direct imaging, indirect imaging

Question 13

Direct digital imaging

Answer 13

Uses an intraoral sensor that transfers info directly to the computer with software

Question 14

Indirect digital imaging

Answer 14

Uses a scanner to convert info into digital form

Question 15

Direct Digital Imaging

Answer 15

Monitor, computer, sensors,printer, traditional x-ray tubehead

Question 16

Direct Digital Imaging (sensors)

Answer 16

sensors were ~14mm thick and could only cover a single molar tooth; modern sensors range from 3.2 - 7mm thick; regular dental film = 0.77mm thick

Question 17

Charge Coupled Device (CCD)

Answer 17

First developed in the 1960’s, first utilized in video cameras, light-sensitive, silicon chip with an embedded electronic circuit, silicon chip is sensitive to x-radiation or light

Question 18

each electron well = ____

Answer 18

1 pixel

Question 19

Complementary Metal Oxide Semiconductor (CMOS)-Active Pixel Sensor (APS)

Answer 19

Integrated circuit like CCD’s, but: pixels are smaller, power requirements are much less, can be connected to the computer using a USB port

Question 20

Active Pixel Sensor (BCTC doesn’t have)

Answer 20

Active amplifying transistor to each pixel (enhances the circuitry capability)

Question 21

Photo Stimuable Phosphors (PSP) or Storage Phosphor Imaging

Answer 21

Imaging plate instead of active detector; developed in 1980’s; reusable plates, no cords, size similar to conventional film, no chemical processing; rare earth phosphor coated plates (blue to the light); laser beam causes fluorescent “signal” reads and converts to digital image.

Question 22

Scan-X process

Answer 22

plates are unwrapped and placed blue side down in transfer box; plates are loaded into scanner; laser beam scans; photodiode-reads signal and transmits image info to computer; plates are “erased” as they go through scanner; image is viewed on computer; plates rewrapped for another use.

Question 23

What is the difference between sensors and plates?

Answer 23

Sensors: wire connection to computer, near instant imaging

Question 24

Direct Imaging vs. Indirect Imaging

Answer 24

Direct:
Indirect:

Question 25

Teledentistry

Answer 25

working via internet to get consultation when dentist isn’t present