(8) Digital Imaging

Method used to convert date element acquired by the sensor are communicated to the computer in analog form and then converted into digital form

Analog-to-digital converter

Number of possible gray-scale combinations possible in an image. Digital information is transmitted and stored as infinite combination of 0 and 1 (bits)

Bit-depth image

a solid state-detector that processes photons and stores info all at the same time. Lowest amount of noise and most common type of sensor

Charge-coupled device (CCD)

Filmless imaging system; a method of capturing an image using a sensor, breaking it into electronic pieces, and presenting and storing the image using a computer and related imaging software.

Digital imaging

An image composed of pixels that come together to form a picture. Can be stored in a computer

Digital image

a method of reversing the gray scale as an image is viewed. Eliminates distracting background information

Digital subtraction

convert an image into digital information so a computer can process it

Digitize

Method of obtaining a digital image, in which a sensor is used

Direct digital imaging

A type of imaging that can be done through scanning radiographs or using storage phosphor imaging

Indirect digital imaging

Measurement used to evaluate the ability of the computer to capture the resolution (or detail) of an image

Line pairs / millimeter (lp/mm)

A digital unit of information. A small box that holds electronic charge caused by photons. Each pixel can only be one shad eof grey

Pixel

In digital imaging, a receptor that is used to capture an intraoral or extraoral image

Sensor

Method of obtaining a digital image in which the image is recorded on a phosphor-coated plate and then placed into an electronic processor, where a laser scans the plate and produces and image on a computer monitor

Storage phosphor imaging

radiographic image produced on traditional film. Continuous shades of grey that blend together, like a painting

Analog

In direct digital imaging, this type of cable transfers image information directly to the computer

fiberoptic cable

What two sensor types can be used in digital imaging?

CCD or CMOS/APS

Pixels are filled line by line, like reading a book. Cheaper to manufacture. Manufacturers of this claim to have 25% better resolution than the other type of digital imaging sensor.

Complementary metal oxide semiconductor / active pixel sensor (CMOS/APS)

Equipment for direct imaging

• computer

• x-radiation source (tubehead)

• intraoral sensor

• film holders

• barriers (infection control)

Converts electronic charge in sensor pixels into shades of gray. Digitizes, processes, and stores information received from sensor. An image can be recorded in 0.5 to 120 seconds

Computer

For this type of equipment, dentistry uses a dental x-ray unit. The timer must be adapted to allow exposures in a time frame of 1/100 of a second

X-radiation source

During indirect digital imaging, when scanning, a ________ camera is used to digitize a traditional radiograph - similar to scanning a photo.

CCD

A type of indirect dental imaging that is like a hybrid of film and digital sensors. Uses thin, reusable image plates

Photo-stimulable phosphor (PSP)

In photo-stimulable phosphor imaging (PSP), the _________ _________ converts photons into light, energizing the phosphor

phosphor coating

Traditional film has poorer image quality. How many shades of gray does traditional film have?

16-25

How many line pairs per millimeter (lp/mm) does traditional film have?

12-20

Digital imaging has better image quality. How many shades of gray does digital imaging have?

up to 256 shades of gray

Shades of gray

contrast

The human eye can detect _____ shades with training, novice individuals only about ____

100, 32

Line pairs per millimeter (lp/mm) are what make resolution or the detail in digital images - the human eye can distinguish ___ to ___ lp/mm

8 - 10

Great tool for showing patients their dental health. Can enlarge, zoom in, use image manipulation, etc. 

Patient education tool

Advantage or disadvantage to digital radiography?

Superior gray-scale resolution

advantage

Advantage or disadvantage to digital radiography?

Reduced exposure to x-radiation

advantage

Advantage or disadvantage to digital radiography?

initial set-up costs

disadvantage

Advantage or disadvantage to digital radiography?

Increased speed of image viewing

advantage

Advantage or disadvantage to digital radiography?

Lower equipment and film cost after set-up

advantage

Advantage or disadvantage to digital radiography?

Sensor size

disadvantage

Advantage or disadvantage to digital radiography?

Infection control

disadvantage

Advantage or disadvantage to digital radiography?

Increased efficiency

advantage

Advantage or disadvantage to digital radiography?

Enhancement of diagnostic image

advantage

Advantage or disadvantage to digital radiography?

Legal issues

disadvantage

Advantage or disadvantage to digital radiography?

Effective patient education tool

advantage

A detector that is used to capture the dental image

sensor

An image receptor found in the intraoral sensor

charge-coupled device (CCD)

A form of indirect digital imaging in which the image is recorded on phosphor-coated plates and then placed into an electronic processor, where a laser scans the plate and produces an image on a computer screen

storage phosphor imaging

To convert an image into digital form that, in turn, can be processed by a computer

digitize

A method of obtaining a digital image in which an intraoral sensor is exposed to x-rays to capture an image that can be viewed on a computer monitor

direct digital imaging

A discrete unit of information; a picture element

pixel

A method of reversing the gray scale as a digital image is viewed

digital subtraction

A filmless imaging system; a method of capturing an image using a sensor; breaking the image into electronic pieces, and presenting and storing the image using a computer

digital radiography

In digital imaging, the term used to describe the picture that is produced is radiograph

true

Digital imaging requires more x-radiation than conventional radiography

false

The x-radiation source used in most digital imaging systems is a conventional dental x-ray unit

true

Compared with the film emulsion, the pixels used in digital imaging are structured in an orderly arrangement

true

All intraoral sensors can be heat-sterilized after use

false

the preferred exposure method for intraoral digital imaging is the paralleling technique

true

Digital subtraction is an advantage in digital imaging because distracting background information is eliminated from the image

true

The manipulation of the original digital images can be considered a legal issue

true

Digital imaging was introduced to dentistry in

1987

Digital imaging can be used for

all of the above

Digital imaging requires less radiation than does conventional radiography because:

the sensor is more sensitive to x-rays

The image receptor found in the intraoral sensor is termed

CCD

Digital imaging systems can be used for which images?

all of the above

All of the following are advantages of digital imaging except:

size of the intraoral sensor