Download Digital ImagingChapter_025

Chapter 25
Digital Imaging
Copyright © 2012, 2006, 2000, 1996 by Saunders, an imprint of Elsevier Inc.
Dental Radiography

Questions



What equipment is used in digital imaging?
What types of digital imaging are available?
What are advantages and disadvantages of digital
imaging?
Copyright © 2012, 2006, 2000, 1996 by Saunders, an imprint of Elsevier Inc.
2
Dental Radiography

Chapter 25 Reading

Iannucci & Howerton (pp. 301-311)
Copyright © 2012, 2006, 2000, 1996 by Saunders, an imprint of Elsevier Inc.
3
Dental Radiography


Chapter 25 Outline
Digital Imaging

Basic concepts
 Types of digital imaging
 Step-by-step procedures
 Advantages and disadvantages
Copyright © 2012, 2006, 2000, 1996 by Saunders, an imprint of Elsevier Inc.
4
Introduction


Iannucci & Howerton (p. 301)
Purpose

To present the basic concepts of digital imaging
 To introduce the types of digital imaging
 To discuss the advantages and disadvantages of
digital imaging
Copyright © 2012, 2006, 2000, 1996 by Saunders, an imprint of Elsevier Inc.
5
Basic Concepts


Iannucci & Howerton (p. 302)
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
Copyright © 2012, 2006, 2000, 1996 by Saunders, an imprint of Elsevier Inc.
6
Terminology





Iannucci & Howerton (p. 302)
Charge-coupled device
Digital radiography
Digital subtraction
Digitize
Copyright © 2012, 2006, 2000, 1996 by Saunders, an imprint of Elsevier Inc.
7
Terminology





Direct digital imaging
Indirect digital imaging
Pixel
Sensor
Storage phosphor imaging
Copyright © 2012, 2006, 2000, 1996 by Saunders, an imprint of Elsevier Inc.
8
Purpose and Use


Iannucci & Howerton (p. 302)
To generate images that can be used in the
diagnosis and assessment of dental disease
Copyright © 2012, 2006, 2000, 1996 by Saunders, an imprint of Elsevier Inc.
9
Purpose and Use






To detect lesions, diseases 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
Copyright © 2012, 2006, 2000, 1996 by Saunders, an imprint of Elsevier Inc.
10
Fundamentals


Iannucci & Howerton (pp. 302-303) (Figs. 25-1,
25-2)
Digital imaging




A method of capturing a radiographic image using
a sensor, breaking it into electronic pieces, and
presenting and storing the image using a
computer
Image used to describe the pictures that are
produced
A sensor placed inside the mouth
The electronic signal is digitized
Copyright © 2012, 2006, 2000, 1996 by Saunders, an imprint of Elsevier Inc.
11
Radiation Exposure


Iannucci & Howerton (p. 303)
The typical sensor is more sensitive to x-rays
than conventional film.

Exposure times are 50% to 80% less than that
required for conventional radiography using Espeed film.
Copyright © 2012, 2006, 2000, 1996 by Saunders, an imprint of Elsevier Inc.
12
Equipment



X-radiation source
Intraoral sensor




Iannucci & Howerton (p. 303)
Charge-coupled device
Complementary metal oxide semiconductor/active
pixel sensor
Charge injection device
Computer
Copyright © 2012, 2006, 2000, 1996 by Saunders, an imprint of Elsevier Inc.
13
X-Radiation Source


Iannucci & Howerton (pp. 303-304) (Fig. 25-3)
Most digital imaging systems use a
conventional dental x-ray unit as the xradiation source.

The x-ray unit timer must be adapted to allow
exposures in a time frame of 1/100 of a second.
Copyright © 2012, 2006, 2000, 1996 by Saunders, an imprint of Elsevier Inc.
14
Intraoral Sensor


Iannucci & Howerton (p.304) (Figs. 25-4, 25-5)
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 fiber optic cable to a
computer.

Wireless
• The imaging sensor is not linked by a cable.
Copyright © 2012, 2006, 2000, 1996 by Saunders, an imprint of Elsevier Inc.
15
Intraoral Sensor

Most popular types of direct sensor
technologies


Charge-coupled device
Complementary metal oxide semiconductor/active
pixel sensor
Copyright © 2012, 2006, 2000, 1996 by Saunders, an imprint of Elsevier Inc.
16
Charge-Coupled Device (CCD)


The most common image receptor used
in dental digital imaging



Iannucci & Howerton (p. 304)
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
Pixel

A small box or “well” into which the electrons
produced by the x-ray exposure are deposited
Copyright © 2012, 2006, 2000, 1996 by Saunders, an imprint of Elsevier Inc.
17
Charge-Coupled Device (CCD)

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.
Copyright © 2012, 2006, 2000, 1996 by Saunders, an imprint of Elsevier Inc.
18
Complementary Metal Oxide
Semiconductor/Active Pixel Sensor
(CMOS/APS)


Iannucci & Howerton (pp. 304-305)
One manufacturer uses a CMOS/APS sensor
instead of a CCD.

The chip is less expensive to produce and offers
greater durability than the CCD.
Copyright © 2012, 2006, 2000, 1996 by Saunders, an imprint of Elsevier Inc.
19
Computer


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


Iannucci & Howerton (p. 305) (Figs. 25-6, 25-7,
25-8)
An image is recorded on a computer monitor in
0.5 to 120 seconds
Has split screen and magnification capability.
Copyright © 2012, 2006, 2000, 1996 by Saunders, an imprint of Elsevier Inc.
20
Types of Digital Imaging


Direct Digital Imaging
Indirect Digital Imaging

Scanning traditional radiographs
 Storage phosphor imaging
Copyright © 2012, 2006, 2000, 1996 by Saunders, an imprint of Elsevier Inc.
21
Direct Digital Imaging


Iannucci & Howerton (p. 306) (Fig. 25-9)
Components include an x-ray machine, an
intraoral sensor, and computer monitor

A sensor is placed into the mouth of the patient
and exposed
 The sensor captures the radiographic image and
transmits it to the computer monitor
 Software is used to enhance and store the image
Copyright © 2012, 2006, 2000, 1996 by Saunders, an imprint of Elsevier Inc.
22
Indirect Digital Imaging


Iannucci & Howerton (p. 306)
Components include a CCD camera and a
computer.


An existing x-ray film is digitized using a CCD
camera.
The image is displayed on a computer monitor.
Copyright © 2012, 2006, 2000, 1996 by Saunders, an imprint of Elsevier Inc.
23
Storage Phosphor Imaging


Iannucci & Howerton (pp. 306-307) (Figs. 25-10,
25-11)
A wireless digital imaging system




This is a reusable imaging plate coated with phosphors is
used instead of a sensor with a fiber optic cable.
The phosphor-coated plates are flexible and fit into the
mouth.
A high-speed scanner is used to convert the information into
electronic files.
This type of digital imaging is less rapid than direct digital
imaging.
Copyright © 2012, 2006, 2000, 1996 by Saunders, an imprint of Elsevier Inc.
24
Step-by-Step Procedures


Sensor Preparation
Sensor Placement
Copyright © 2012, 2006, 2000, 1996 by Saunders, an imprint of Elsevier Inc.
25
Step-by-Step Procedures

It is critical to refer to the manufacturerprovided instruction booklet for information
concerning the operation of the system,
equipment preparation, patient preparation,
and exposure.
Copyright © 2012, 2006, 2000, 1996 by Saunders, an imprint of Elsevier Inc.
26
Sensor Preparation


Iannucci & Howerton (p. 307) (Figs. 25-12, 25-13)
Each sensor is sealed and waterproofed.

The sensor must be covered with a disposable
barrier because it cannot be sterilized.
Copyright © 2012, 2006, 2000, 1996 by Saunders, an imprint of Elsevier Inc.
27
Sensor Placement


Iannucci & Howerton (pp. 307-308) (Fig. 25-14)
The sensor is held in the mouth by bite-block
attachments or devices that aim the beam
and sensor accurately.

The paralleling technique is the preferred
exposure method.
Copyright © 2012, 2006, 2000, 1996 by Saunders, an imprint of Elsevier Inc.
28
Advantages and Disadvantages


Advantages of Digital Imaging
Disadvantages of Digital Imaging
Copyright © 2012, 2006, 2000, 1996 by Saunders, an imprint of Elsevier Inc.
29
Advantages of Digital Imaging








Iannucci & Howerton (pp. 307-309) (Figs. 25-15,
25-16, 25-17, 25-18)
Superior gray-scale resolution
Reduced exposure to x-radiation
Increased speed of image viewing
Lower equipment and film cost
Increased efficiency
Enhancement of diagnostic image
Effective patient education tool
Copyright © 2012, 2006, 2000, 1996 by Saunders, an imprint of Elsevier Inc.
30
Disadvantages of Digital Imaging






Iannucci & Howerton (pp. 309-310)
Initial set-up costs
Image quality
Sensor size
Infection control
Legal issues
Copyright © 2012, 2006, 2000, 1996 by Saunders, an imprint of Elsevier Inc.
31