juan f. yepes, d.d.s., m.d., m.p.h. assistant professor director of oral and maxillofacial radiology...

Juan F. Yepes, D.D.S., M.D., M.P.H.Assistant Professor

Director of Oral and Maxillofacial RadiologyDivision of Oral Diagnosis, Medicine and Radiology

Department of Diagnostic RadiologyChandler Medical Center

Digital Radiology 2009

ODM 880

2009

Digital Radiology

CBCT

CT – MRI

Cases

1. Types of Systems

2. How it works ?

3. Available Products

Outline / Objectives

Financial Disclosure

“Sharpen your diagnostic ability.”

“...immediately enhance your diagnostic capabilities.”

Some comments……

“...the low dosage [sic] requirement....means that you can afford one or two extra control pictures for root fillings or other complex jobs.”

“Increase treatment acceptance with our HANDheld computer that every patient can see.”

“The microprocessor controlled timer will automatically adjust the exposure time to take perfect quality x-rays.”

“The [name of unit] x-rays exceed the international standards for total radiation safety...up to 95% less scatter radiation than the government allows.”

“I simply let ...[the patients]...know that they’ll be getting about 90% less radiation than they would from a standard x-ray.”

“The images come up instantly as patients are in the chair; the images are so large that patients can’t help but become involved in the diagnosis. I never expected them to be so enthusiastic.”

“Most patients are amazed at how quickly the image comes up on the screen and are impressed by its size.”

“I don’t spend a lot of time trying to sell the technology. I simply let patients know what it is and let them see the images.”

“I use the contrast change regularly....I shift through all the variances of gray scale. This allows me to find pathologies that might not otherwise be evident”

“...requires much lower exposure-times than film thus reducing the patient’s radiation consumption dose.”

“I always let ...[the patients]...know that ... I can diagnose more accurately and precisely than with traditional radiographs.”

“Patients will view the the doctor as making a more accurate diagnosis by using improved technology.”

“There is potential for a tremendous flow of new patients, since approximately 50% of the population does not regularly visit a dentist...

...When new patients arrive, many of them have acute problems. This is the time to begin to use the technology...

...Take the initial radiographs and examine the acute problem when the patient arrives in the practice...

... The images can be immediately brought up on the screen for the patient to view and it can be magnified from 100% to 300%.”

“It combines superior design with outstanding performance, resulting in perfect quality x-rays.”

“It’s been more than 100 years since X-rays were invented.”

Standard Radiographs

• Image receptor: film• Image processing: photochemical

(developing, fixing, washing/rinsing, drying)• Viewing: radiograph on illuminator• Storage: radiograph

Digital Images

• Image receptor: CCD or screen

• Image processing: cpu and software or laser, cpu and software

• Viewing: image on screen or print-out

• Storage: on disk or paper hard copy

Advantages/DisadvantagesRadiographs vs. Digital Images

• portable • not portable*• familiar• can be viewed by all

• initially inexpensive

• must send by mail• one viewer or

duplicate (duplitized)

• new technology*• must have

hardware/software• inexpensive after

initial investment• transmissible by wire*

• viewed simultaneously

Advantages/DisadvantagesDigital Images: new technology = uncertainty


• no inherent measurements

• software driven measurements

• film size similar to beam size

• film covers larger area

• receptor size smaller than beam size (DR/cable systems)

• receptor covers smaller area (DR/cable systems)


• EPA film disposal • no film disposal• EPA chemical/silver

disposal/recovery• film placement is easy

• easy to view multiple images (shuffling)

• no chemicals

• cable connection interferes with placement (CCD)

• awkward to view multiple images (shuffling)


• caries detection • caries detection*• periodontal bone loss• periapical bone loss

• complete mouth survey

• bony lesions

• poor for soft tissue lesions

• periodontal bone loss• periapical bone loss

• complete mouth survey*

• bony lesions

• soft tissue lesions?

Dental Digital Imaging:

Where are we as of

January 2009?

Status of Current Technology (500 dentist)

• 30 + different brands of equipment are in use

• 61% of dentist paid $ 10,000 - $ 30,000 for the system

• 76% of the dentist in USA would purchase the same system again

• 80% of dentist in USA reported that the image quality and diagnostic capabilities were similar to or better than conventional radiology

• Image enhancement tools used most were: magnify, enhance, contrast and inverse

Status of Current Technology (500 dentist)

• Major advantages: instant image, patient communication, image enhancement, no processing, less radiation, image magnification

• Major disadvantages: high cost, uncomfortable sensors, poor image quality, difficult to learn and implement, dependent on computer, technical problems

• 89% of dentist in USA using digital radiology recommended that colleagues switch to digital now rather than continue to wait

Filmless Imaging

• 1895: Wilhelm Conrad Roentgen X-rays

• Two weeks after: Otto Walkoff: First dental x-ray

• ALARA principle “As low as reasonably achievable”

• 1980: First digital x-ray sensor for use in dentistry

• 2006: End of the film-base radiology?

Digital Imaging:

Most significant advantages:

- Computer-aided image interpretation- Image enhancement- Image archiving- Image retrieval

Digital Imaging

More Advantages

- Chemical processing- Hazardous wastes- Images can be transferred electronically- Patient Education- Time- Less Radiation- One thousand more depending of the vendor

Digital Imaging

Disadvantages

- Cost- Susceptible to use and abuse- Obsolete very fast- System crash- Same geometry limitations than conventional radiology- Storage and back up

Digital Imaging

BASIC PRINCIPLES

Digital System numeric

Spatial Distribution of the pictureelements PIXEL

Different shades of gray PIXEL

Digital Imaging

Each pixel has a row and a column coordinates thatidentifies its location in the matrix

Digital Imaging

How the image is produced?

Pixel Electronic Detector Absorption of x-rays Generates a small voltage

electron

X-rays

Digital Imaging


electron

X-rays

Maximum

Minimum

(analog system)

Production of the digital imaging

What is a Digital Imaging?

- Pixel: the photon intensity is measured electronically on a scale of 256 gray values (0-255) 0= maximum radiation (black) 255= minimum radiation (white)

-The measurements of the photon intensities for each pixel are sent to the computer an stored as an array of numbers representing the x and y coordinates.

Digital Imaging


X-rays Patient Receptor Image Detection

INTERPRETATION!!

Digital Imaging

Digital Detectors

1. CCDCharge – Couple - Device

2. CMOSComplementary metal oxide semiconductors

3. PSPPhoto-stimulable-phosphourosplates

Direct system

Direct system

Indirect system

Filmless Imaging

CCD

- Solid-state sensor

- Electronic chip used to capture the image

- The chip converts into an electronic signal the energy of the x-ray photons hitting the sensor

-To increase the efficiency scintillation layer: converts x-ray photons into light photons

Digital Imaging

CCD Introduced to dentistry in 1987

Silicon

Covalent bonds between atomsare broken producing ELECTRONS

Number the electrons is proportionalto the amount of exposure that anarea receives

X-RAY

Digital Imaging

Electrons are attracted toward the most positivepotential and create “charge packets” 1 PIXEL

Data is transferred in rows Cable Computer

Wireless systems

How CCD works?

CCD/CMOS/Flat panel (cable)

Charge-Coupled Devices

C.C.D. with ScintillationLayerX R A Y S

ELECTRONIC MESSAGEELECTRONIC MESSAGEC.C.D.

SCINTILLATION LAYER

How CCDs Work

Digital Imaging

CMOS

Complementary metal oxide semiconductors

- Different from CCDs in the way that pixel charges are read

- Each pixel is directly connected to the transistor

- Each pixel generates electrons in proportion to the amount of x-ray energy that is absorbed

-Voltage is display independently on the screen

Filmless Imaging

CMOS

- Solid-state sensor

- CMOS chip: more of the electronic components controlling the conversion of photon energy into the electronic signal are incorporated into the chip

-Chip: less expensive, simple production process

-CCD and CMOS comparable image quality

CCD/CMOS/Flat panel (cable)

Charge-Coupled Devices

Units Available

• CR (Computed Radiography)• PSP/SP

Photo-stimulable-phosphorous plates

Plates absorb and store energy from x-rays and the release of this energy as light when stimulated by other light

Filmless Imaging

PSP

- Phosphor layer store the energy of the x-ray photons

- A scanner is required to read the image

- The energy is released and detected by an imaging intensifier and subsequent converted into digital imaging

-The latent image will remain in the PSP before the scanning phase for minutes to hours.

How PSPs/SPs Work

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Photostimuable/Storage phosphors

How PSPs/SPs Work

europium-activated barium fluorohalide

How PSPs/SPs Work

europium-activated barium fluorohalide

How PSPs/SPs Work

X R A Y S

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Choosing a System….

CCD and CMOS

PSP

Extra-Oral systems

- Type of practice- Type of patients- Money- Storage- Insurance- Software- Hardware- Staff- Previous experiences

Dose Reduction

It is considered to be one of the most importantadvantages of digital radiology……However:

- Intraoral versus extraoral- PSP: can provide a good images even when the exposure time has been much greater than the require for film-base imaging the user is not warned by an unsatisfactory image-CCD and CMOS: small exposure range

Security Aspects

- Possibility to change the look of digital radiograph

- Storage of the original film

- Concept of “watermarks”

- Detection of altered images

- Film base versus digital radiology

Implementation of Digital Radiology

Intraoral Systems

Intraoral SystemsDR/Cable Systems

• RVG 6100Kodak Dental System Group www.kodak.com/dental

• Computed Digital Radiography: CDRSchick Technologies 800-645-4312

• SIDEXIS IO2Sirona Dental Systems 800-659-1505

• DEXISDEXIS Digital X-Ray 888-883-3947

• ImageRAYiDentrix 800-336-8749

• Lightyear (Light Year Technology) 1-678-990-4030

Intraoral SystemsDR/Cable Systems

• SigmaSigma Instrumentarium 800-558-6120

• VisualiX eHDGendex Imaging 1-888-275-5286

• Dixi-3Planmeca 630-595-7077

• MDX Digital SensorMediaDent 800-868-5038

• CleartoothCleartooth Electronics 1-800-206-4557

• OpTimeA Soredex USA, 1-800-558-6120

• DenOptix QSTGendex Imaging 1-800-769-2909

• ScanX Air Techniques 1-800-247-8324

Intraoral SystemsPSP Systems

Digital Radiography System

General Considerations

• Existing set-up in your office: x-ray machine, computer equipment, and practice manager software

• Electronic transfer capabilities

• DICOM – complaint systems

• Hands-on session with the vendors

Factors that might influence your purchasing decision:

• Sensors: Size ShapePositioning devices

• Software features

• X-ray generator 16 – inch collimatorRectangular

Factors that might influence your purchasing decision:

• Computer equipment: ProcessorSystem memory (RAM)Hard disk space

• Practice Management:

• DICOM compliance:

Problems Comparing Systems

• Articles comparing systems no longer up-to-date

• Systems compared to D speed or E speed film

• Dose reductions compared to what exposure of films

Problems Comparing Systems

• Manufacturers unable to provide answers

• Manufacturers unwilling to provide answers

• Manufacturers providing incorrect answers

• Manufacturers providing inconsistent answers

• Manufacturers changing products on the fly

ADA in 2006 evaluated 7* direct digital system:

• DIXI 3 Planmeca• CDR Schick Technologies• Image RAYi Dentrix Dental System• RVG 6000 Kodak Dental Systems• Sigma Instrumentarium Dental, Inc.• VisualiX eHDGENDEX Dental Systems• DEXIS * Dexis LCC

19 clinicians under standard conditions for interpretation

Perceptibility TestAccuracy, Sensitivity, and Specificity of Evaluated Systems

CDR 93.2 88.9 98.9

DIXI 86.3 80.0 98.9

ImageRAYi 93.7 91.1 98.9

RVG 94.0 91.1 100

Sigma 88.6 82.9 100

VisualiX 86 81.1 95.8

Accuracy Sensitivity Specificity

Image Quality Test

Clinical Significance: To compare the ability of different systems todepict normal dental structures as evaluated by dentist evaluators

Each dentist viewed each set offour images and selected oneimage for each system that she orhe judged as offering the highestdiagnostic quality**

Diagnostic Quality: The ability to identify the dentin-enamel junction,PDL space, pulp chamber and root canals

Image Quality Test

CDR 6 6.37

ImageRAYi 5 5.11

RVG 60004 4.79

VisualiX 3 4.47

Sigma 2 4.05

DIXI 31 2.32

Score Average score

ADA Professional Product Review

CDR CMOS

DenOptix PSP

DIXI 3 CCD

Suni CCD

ImageRAYi CCD

Lightyear CCD

RVG 6000 CMOS

Scan X PSP

Sigma CCD

VisualiX CCD

Which one of the following digital radiography systems do you use most often?

N=161

A comparison of 18 different x-ray detectors currently usedIn dentistry

AG Farman, TT Farman, OOOO 2005

Purpose: Provide a basic comparison of spatial resolution, contrastperceptibility, and relatively exposure of 18 current dental x-raydetectors

Methods: Spatial resolution Phantom test gridContrast perceptibility aluminum perception test deviceRelatively exposure expert consensus of the clear

discrimination of the ED junction

Results: Highest spatial resolution: Kodak RVG 6000 – Planmeca DixiContrast resolution: Kodak RVG 6000 – Visualix eHDRelatively exposure: PSP – Kodak RVG 6000

Kodak

Dental Film

Standard Dental X-ray Films

35 x 22

40 x 24 41 x 31

54 x27

0 1 23

Comparison of Intraoral Systems“I” Sensor Configurations

•RadioVisioGraphy: RVG 6100•Computed Digital Radiography: CDR•SIDEXIS IO2•Lightyear (lightyear technology)

Comparison of Intraoral Systems“Q” Sensor Configurations

•DEXIS

RVG 6100

Cost $ 13,895

Warranty 3 years

Sensor size # 0 # 1 and # 2

Extraoral options Yes

Sensor Comfort Fair

Ease to Set-up Excellent

Speed Excellent

Enhancement tools E

Features:

- Very good image quality- Excellent enhancement tools- Sensor can be soaked- Overall grade: 3.6

Clinician guide to Dental Products and Technology

Logicom ®

Dexis ®

Cost $ 13,995

Warranty 1 years

Sensor size # 2


Sensor Comfort Good


Speed Excellent

Enhancement tools Good

Features:

- Good sensor comfort- Good image quality- Optimized for laptop- Overall grade: 3.5

CRA Foundation

DEXIS Receptor vs. #1 and 2 Dental X-ray Films

40 x 24

41 x 31

32 x 25.6

http://www.dexis.com/index.php?option=content&task=view&id=106

http://www.dexis.com/index.php?option=content&task=view&id=106

31 x 1.524 x 1.5

29.5 x 8.8

DEXIS Receptor vs. #1 and 2 Dental X-ray Films

DEXIS Receptor

ImageRAYi (Dentrix)

Cost (kit) $ 13,090

Warranty 2 years

Sensor size # 1 and # 2

Extraoral options None

Sensor Comfort Fair


Speed Good (10 sec)

Enhancement tools Excellent

Features:

- Minimum radiation- Excellent image quality- Excellent enhancement tools- Overall grade: 3.4

CRA Foundation

CDR (Schick Technologies))

Cost (kit) $ 11,764

Warranty 2 years

Sensor size # 0, # 1 and # 2


Sensor Comfort Fair


Speed Excellent (3 sec)

Enhancement tools Good

Features:

- Good image quality- Wireless option- SDX x-ray head available- Overall grade: 3.4

CRA Foundation

CDR Receptor vs. #0, 1 and 2 Dental X-ray Films

21x15 35 x 19 37 x 25

35 x 22 40 x 24 41 x 31

CDR Receptor vs. #0, 1 and 2 Dental X-ray Films

29 x 5

23 x 519 x 5

31 x 1.5

24 x 1.522 x 1.5

CDR Plus Wire ®

http://www.schicktech.com/

Sidexis XIOS (Sirona Corporation)

Cost (kit) $ 12,560

Warranty 2 years



Sensor Comfort Good



Enhancement tools Fair

Features:

- Good sensor comfort- Minimum radiation- Overall grade: 3.1

CRA Foundation

SIDEXIS Receptor vs. #1 and 2 Dental X-ray Films

37.3 x 22.3

40 x 24

41 x 31

31 x 1.524 x 1.5

29.5 x 6

SIDEXIS Receptor vs. #1 and 2 Dental X-ray Films

Lightyear

Cost (kit) $ 9,995

Warranty 5 years



Sensor Comfort Poor


Speed Good (10 sec)

Enhancement tools Fair

Features:

- Lowest cost- 5 year warranty - Overall grade: 2.8

CRA Foundation

Sigma – Snapshot (Instrumentarium)

Cost (kit) $ 11,920

Warranty 2 years



Sensor Comfort Good




Features:

- Good sensor comfort- Sensor can be soaked - Overall grade: 3.6

CRA Foundation

Dixi ® (Planmeca)

Cost (kit) $ 12,661

Warranty 2 years



Sensor Comfort Fair




Features:

- Good sensor comfort- Sensor can be soaked- X-ray head available - Overall grade: 3.6

CRA Foundation

Planmeca Dixi ® Receptors

Dr. Suni (Suni medical Imaging)

Cost (kit) $ 9,661

Warranty 1 years



Sensor Comfort Good


Speed Good (8 sec)


Features:

- Minimum radiation- Thin sensor- Overall grade: 3.1

CRA Foundation

http://www.suni.com/default.aspx

http://www.suni.com/content/products/SuniRay_intraoral_sensors.aspx

http://www.suni.com/content/products/DrSuniPlus_intraoral_sensors.aspx

OPTime (Sorodex USA) PSP

Cost (kit) $ 11,600

Warranty 2 years

Sensor size # 0, # 1 # 2 # 3


Sensor Comfort Good


Speed Good (49 seconds)


Features:

- Very good image quality- Easy clinical implementation- Single plate scanner- Overall grade: 3.0

CRA Foundation

OPTime Receptor vs. #0 and 2 Dental X-ray Films

31 x 1.5

22 x 1.5

35 x 1.6

26 x 1.6

DenOptix QST (Gendex Imaging) PSP

Cost (kit) $ 13,995

Warranty 2 years

Sensor size # 0, # 1 # 2 # 3


Sensor Comfort Good




Features:

- Very good image quality- Easy clinical implementation- Carrousel scanner- Overall grade: 2.7

CRA Foundation

DenOptix Receptor vs. #1 and 2 Dental X-ray Films

40 x 24

41 x 31

40 x 24

41 x 31


35 x 22

41 x 31

35 x 22

41 x 31


31 x 1.5

22 x 1.5

31 x 1.6

22 x 1.6

Imaging plates the size of dental film

Gendex DenOptix

Imaging plates are flexible

Gendex DenOptix

Holders similar to dental film

Gendex DenOptix

Load plates onto scanning carousel

Gendex DenOptix

Gendex DenOptix

Can scan up to 29 plates at one time. There are intra- and extraoral plates and carousels

ScanX (Air techniques) PSP

Cost (kit) $ 19,995

Warranty 2 years

Sensor size # 0, 1, 2, 3, 4


Sensor Comfort Fair




Features:

- Very good image quality- Easy clinical implementation- Overall grade: 3.1

CRA Foundation

Intraoral plates on scanning drum

DENT-X Scan-A-Ray 500

Can scan only 6 plates at one time.Scan time: 50 sec.

DENT-X Scan-A-Ray 500

So, what should I look

for?

So what should I look for...?

• Do I need this now?• What comes with the price?• Is the image format proprietary?• Can I communicate with other

practitioners (or other offices)?• If so, can I (or they) manipulate the

image?

• How easy is it to back up the images?• Do the insurance carriers that I deal

with accept digital images, and how?• Is the image varifiable (for alteration)?• Can I process multiple images from

different patients, and split them?• What about a warranty (and with

whom)?


• Is the image compressed or noncompressed?

• Can I get upgraded software and if so, what would it cost?

• Will there be upward compatibility of images?

• How is servicing handled? Cost, availability, time to arrive?


juan f. yepes, d.d.s., m.d., m.p.h. assistant professor director of oral and maxillofacial radiology...

Documents

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