Digtal radiography and imaging

RECENT ADVANCES
IN DIAGNOSTIC AIDS
RECENT ADVANCES
IN DIAGNOSTIC AIDS
www.indiandentalacademy.com

Digital radiography and imagingDigital radiography and imaging

• Overview of methods to obtain a digital radiograph
• Advantages and disadvantages of digital
radiography.
• Digital radiography and imaging software's
• Digital cephalometry and its applications
• Reliability of digital versus conventional
cephalometry
• Various digital cephalometry software's and their
applications

Two main methods of acquiringTwo main methods of acquiring
• Direct digitization
• Indirect digitazition

Direct digitizationDirect digitization
• Sensor based acquisition
- CCD
- CMOS-aps
• Sonic digitization/contact sensors

Indirect digitizationIndirect digitization
• Photostimulable phosphor plate storage (psp)
• Scanning of conventional radiographic film

Sensor based digitizationSensor based digitization
CCD ( charged couple device)
CMOS-aps ( complementary metal oxide
semi-conductors – active pixel sensor )

CCD sensorsCCD sensors
• This method was first introduced by trophy
in the 1980s.
• Solid state detectors composed of an array
of light sensitive pixels on a silicon chip.

How they workHow they work

CMOS -APS vs CCDCMOS -APS vs CCD
• CMOS far more superior than CCD.
• Cheaper than CCD sensors
• Less power consumption
• Long lasting sensors.

DrawbacksDrawbacks
• Mainly used for intra oral ( incompatible for
extra oral )
• Require wires to be connected to the
computer ( now wireless available)
• Sometimes new ceph/pan units are required
not compatible with old units.

Dimension for CCD sensorsDimension for CCD sensors
• View delay 1-4 s
• Sensor thickness 4mm
• Sensor cable diameter 3mm

ManufacturesManufactures
• Planmeca dimax
• Villa systems

Sonic digitization/contact sensorsSonic digitization/contact sensors

PrinciplePrinciple
• Uses the analysis and conversion of
reflected ultrasound waves into
radiographic data
• Simultaneous video/photographic capture
possible

ManufacturersManufacturers
• Dolphin imaging systems-digigraph
• Microscribe 3d xl – 3d digitization also
possible

• Psp (photo stimulable phosphor storage
technology)

What is psp?What is psp?
• Digital psp solutions eliminate the
traditional film processor and delivers the
size range and flexibility of traditional film
in a digital format.

• Consists of a polyester tube coated with
crystalline halide emulsion,that converts x
ray into stored energy.

How does it work?How does it work?

Benefits of pspBenefits of psp
• Value
• Reduced image processing time
• Ease of integration
• Easy to manipulate
• Flexibility
• Low risk involvement

ManufacturersManufacturers
• Denoptix

• Scanning of transparency film.
• Digitizing modes

Digitizing tabletDigitizing tablet

• Resolution
1000 lines /40inch
• accuracy

Types of digitizersTypes of digitizers
• Point digitization
• Stream digitization

Digitizaton errorsDigitizaton errors
• Improper selection of points digitized
• Movement of head film
• Linearity of digitizer.

ScannersScanners
• Drum
• Flat bed

ProcedureProcedure
• Scan images at high resolution
• Second image on screen from which
landmarks and contours are recorded with a
mouse.

Video camera and frame grabberVideo camera and frame grabber

Advantages of digital radiographyAdvantages of digital radiography
• Data manipulation on a computer

• Integration with photographic and other
patient charts

• Storage and retrieval

• Enhancement of digital image and
immediate acquisition of the image.

• Reduced radiation dose
• No need for chemical dark room process

DisadvantagesDisadvantages
• Cost
• Digitizing errors
- head film movement
- improper sequencing of digitized points.

DIGIGRAPHDIGIGRAPH
DIGIGRAPH WORK STATION

DIGIGRAPHDIGIGRAPH
DIGIGRAPH HEAD HOLDER

Digital cephalometryDigital cephalometry

Vital toolVital tool
• Evaluation of craniofacial complex
• Determination of morphology and growth
• Diagnosis and anomalies
• Forecasting of future relationships
• Planning treatment and evaluating the
results of growth and effects of treatment.

Lateral cephalogramsLateral cephalograms
• Quantifying dentofacial parameters in
individuals as well as groups of individuals
• Distinguishing normal from abnormal
• Comparing treated samples an untreated
controls
• Differentiating populations as homogenous
or mixed and assessing change of pattern
over time.

• Reliability of digital versus conventional
cephalometric radiography;a comparative
evaluation of landmark identification error.
scott .et.al (seminar in orthod 2005)
Results – statistically significant differences
X axis – point A
Y axis – ANS AND CO
These differences were about 1 mm which was not
considered clinically significant.
Conclusion – similar precision in landmark
identification in both conventional and digital
head films. www.indiandentalacademy.com

• Dose reduction by direct digital
cephalometry radiography.
heiko.et.al ( the angle orthodontist vol
71:159-163).
Results – demonstrated that direct digital
cephalometry cuts the patients dose by half
when compared with the conventional
cephalometric tracing.

• Reproducibility of cephalometric radiographs on
conventional film,hardcopy and monitor displayed
images by storage phosphor technique.
gelen.et.al ( ejo 1998:20;331-340)
Conclusion – the reproducibility of cephalometric
landmarks on film,hard copy and monitor based
images for 11 of 21 landmarks.
Overall reproducibility of a full ceph recording for
the monitor displayed image than the film or
hardcopy,between which there is no significant
difference. www.indiandentalacademy.com

• Accuracy of computerized identification of
cephalometric landmarks
jia.et.al ( ajo-do 2000:535-540)
• Comparison of landmark identification in
traditional versus computer aided digital
cephalometry
the angle orthod 2000 ;70:387-392

• Reliability of landmark identification in
cephalometric radiography by storage
phosphor system
• A comparison of conventional and digital
radiographic methods
mark.et.al (seminar in orthodontics 2004)

softwaressoftwares
• A plethora of software's are available to the clinician –
vistadent
dolphin
quickceph
dentofacial planner
dr ceph
orthoplan
vixwin
• Internet software's
- ceph x
- orthoview ceph

Factors to be consideredFactors to be considered
• Facility of integration of photographs and
study models

• Windows based system available

• Dicom compatible

• Lateral as well as postero-anterior analysis
possible

Softwares in IndiaSoftwares in India
• Digi ceph
• Method for computer analysis and
superimposition.
• 13 cephalometric analysis possible
• Developed by centre for bio medical
engineering, IIT Delhi and department of
dental surgery AIIMS.

DICOMDICOM
• DENTAL IMAGING AND
COMMUNICATIONS IN MEDICINE

• American college of radiology (ACR) and
national electrical manufacturers
association
( NEMA) formed a joint committee in order
to create standard method for transmission
of medical images and their assisted
information

• DICOM defined information standardized not
only for images but also for
patients,students,reports and other data groupings
• With the enhancements made in DICOM came the
development and expansion of picture archiving
and communications systems and its interfacing
medical information systems.

SOTWARESSOTWARES

CONCLUSIONCONCLUSION

Digtal radiography and imaging

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