Image receptor for Oral Radiology

2.  Definition
 History
 Highlights in Image Receptors
 Classification
 Analog v/s Digital
 Intra-Oral Radiographs
 Extra-Oral Radiographs
 Digital Image Receptors
 Pathogens on Image Receptors
 Conclusion
 References

3. The term ‘Image Receptor’ refers to any device
that changes the x-ray beam into visible image .
Film , Charged-Couple Device (CCD) or
Complementary Metal Oxide Semiconductors
(CMOS) sensors , or Phosphorescent Screen or
a Special detector placed in a table or a Bucky
diaphragm (used in direct digital radiography).
(http://medical-dictionary.thefreedictionary.com)

4. FIRST “FILM”
• Glass plates
– Break easily
– Difficulty in storage
– Expensive
• Cellulose Nitrate
– Highly flammable
– Easily torn

5. YEARS CONCEPTS PERSONS ASSOCIATED
1895 Discovery of X-rays Prof. WC Roentgen
1896 First dental radiograph Dr. O Walkoff
1913 First pre-wrapped dental
films
Eastman Kodak Co.
1920 First machine-made films Eastman Kodak Co.
1955 Introduction of D-Films
1981 Introduction of E-Films
2000 Introduction of F-Films

7. Image Receptors can be classified based on the Diagnostic
Technique :
1. X –Ray Radiographic Receptors
2. Specialized X-Ray Radiographic Receptors
3. Radiofrequency Waves Receptors

8. • The X-Ray Film is the image receptor system used in dental
radiology.
• The X-Ray Films are classified according to:
A.Their use :
a. Intra-oral films
i. Periapical films
ii. Occlusal films (also called bite film/ topographical film)
iii. Bite wing films
b. Extra-oral films

9. B. The coating of emulsion :
a. Single Coated : These produce better and sharper
images but the exposure to the patient is more therefore mostly
used in industrial Radiography.
b. Double Coated: These films have emulsion on both sides
. Most dental films are double coated. These allows for less
exposure to the patient.

10. C. The Speed of the film:
a. Slow films: these have very small grain of silver bromide
and emulsion is on one side only. Therefore it gives better
definition but the exposure required is more and are
thus not routinely used. Their speeds are denoted by A, B, C.
b. Fast films: These have a larger grain size and the
emulsion is on both sides. Their speeds are D-ultra speed E-
ekta speed and F-ultra ekta speed.
c. Hyper speed G: This is a 800-speed film that can half the
patient exposure without blurring image quality.

11. D. Packaging :
a. Single film packet
b. Double film packet: Two films are placed close to each
other when they radiographed the second film serves as a
duplicate.
E. Use, nonuse of screen:
a. Screen Films:
i. sensitive to blue light E.g.: calcium tungstate
screens (Kodak X-Omat and Ektamat films)
ii. Sensitive to green light E.g.: Rare Earth Screens
(Kodak Ortho and T-Mat films)
b. Non-screen films

12. F. Barrier Envelopes
a. With barrier envelopes: these ensures that there is no
gross contamination in the dark room.
b. Without barrier envelopes.
( From Textbook of Dental and Maxillofacial Radiology By Karjodkar – 2nd ED. )

14. Intra-Oral Radiography
Bitewing Periapical Occlusal
Bisecting Angle Technique
Paralleling Technique
Topographic
Cross-Sectional

15. • 2 Digits separated by a Decimal Point
LEFT DIGIT (THE TYPE OF FILM)
1- Periapical Film
2- Bitewing Film
3- Occlusal Film
RIGHT DIGIT (THE SIZE OF
FILM)
0 ,1, 2, 3, 4

16. • #0 : Children (PA &BW)
•#1 : Adults PA Anterior (Paralleling Technique) or Children (BW)
•#2 : Adults PA (Anterior & Posterior) or BW or Children (Occlus
•#3 : Extra long BW
•#4 : Occlusal

17. Periapical Films
Size 0
22x35mm
Size 1
24x40mm
Size 2
31x41mm
Child Projection Anterior adult projection Standard Adult Projection
Bite Wing Films
Size 0
22x35mm
Size 1
24x40mm
Size 2
31x41mm
Size 3
27x54mm
Child Projection Anterior adult projection Standard Adult Projection Anterior adult
Occlusal Films
57x76mm

21. A Speed
B Speed
C Speed
D Speed (Ultra Speed)
E Speed (Ekta Speed)
F Speed (InSight)
Speed
SizeOfCrystals
Sharpness
The most effective means of reducing time of exposure the amount of radiation
reaching the patient and the amount of radiation scattered to the dentist is using
a higher speed of film.

25. • it shows the crowns and the interproximal alveolar bone of the both arches on the same film.

26. • Shows large parts of Maxillary Arch and Mandibular Arch parts of maxilla and floor of mouth.

27.  These films are of two types: Non Screen Films and Screen Films.
 Both are available in various sizes : 4 ¾” x 6 ½”
5” x 7”
6 ½” x 8”
8” x 10”
6” x 12”
10” x 12”
•Panoramic •Lateral Jaw •Skull Views
•Cephalometrics • TMJ

29. red arrow = head of condyle black arrow = glenoid fossa

30. X-rays

40. • In a Refrigerator in cool and dry conditions
• Away from all sources of ionizing radiation
• Away from chemical fumes
• Boxes placed on their edges to prevent pressure artifacts
•Optimum temperature 50˚ to 70˚F and Rel. Humidity 30-50%

41. Direct Action Film Or
Non Screen Film
Indirect Action Film or
Screen Film
•Sensitive primarily to x-rays
photons
•Used Intra-orally
•Periapical
•Bitewing
•Occlusal
•Sensitive primarily to light
photons (Fluorescent Light)
•Used Extra-orally
•Lateral Oblique
•Skull Radiographs
•Panoramic Radiographs
•All routine Medical
Radiographs

42. Digital Receptors
Direct
Solid-State Sensors
CCD (Charged
Couple Device)
CMOS
(Complementary
Metal oxide
Sensors)
Indirect
PSP
(PhotoStimulable Phosphorus
State Plates)

43. ANALOG v/s DIGITAL
• The term digital in digital imaging refers to the numeric format
of the image content and its discreteness.
•Conventional film images can be considered an analog
medium in which differences in the size and distribution of black
metallic silver result in a continuous density spectrum.
•Digital images are numeric and discrete in two ways :
1) in terms of spatial distribution of the picture
elements (pixels) and
2) in terms of the different shades of gray of each of
the pixels.

44. • A pixel is a small box or “well” into which the electrons produced
by the X-ray exposure are deposited.
• A pixel is equivalent of a silver crystal used in conventional
radiograph.
• As opposed to film emulsion that contains a random arrangement
of silver crystals , a pixel is structured in an ordered arrangement.
• Production of a Digital image requires a process called Analog – to –
Digital Conversion (ADC). This consists of 2 steps : 1. Sampling
2. Quantization

45. • An analog signal is a continuous electrical wave that varies in
response to changes in the sound or image being transmitted. A
digital signal is a sequence of pulses. The original information is
converted into a series of ON/OFF signals (bits) before being
transmitted, sort of like Morse code.
•Why is digital better? Digital signals can be sent for longer distances
and are less prone to interference than analog signals. And since a
digital signal is just a string of numbers, it can be reproduced exactly,
an unlimited number of times. By contrast, analog signals cannot be
copied perfectly. Each copy of an analog audio or video recording will
have deterioration.
Read more: http://askbobrankin.com/analog_to_digital_tv_conversion.html#ixzz1r6iZ9tdQ

49. Digital extra oral images

54. Sensor
Plastic
sleeve

57. Digital Subtraction Radiography

58. (The Journal of Contemporary Dental Medicine, Vol. 3, number 4, Nov.15 2002)

59. Performance comparison between Three Intra-oral image
receptors of different technology :
• The intra-oral radiographic receptors evaluated were : The Kodak
Insight F speed class film, the Kodak RVG 6000, and the Duerr
Vitascan Combi PSP system.
•For each image the total image quality score (TS) was derived.
Model Manufa
cturer
Pixel
Size
(μm)
Technology Software Bit
Pixel
Width Height File
Size
(MB)
INSIGHT KODAK N/A SILVER
HALIDE
N/A N/A 3.1cm 4.1cm N/A
RVG
6000
KODAK 18.5 X
18.5
CMOS KODAK
WINDOWS
6.0.1
8 1200
PIXELS
1600
PIXELS
1.8
PSP
VISTASC
AN
DUERR SCAN
PITCH
12.5
IMAGE
PLATE
DBSWIN
V.3.3
16 2476
PIXELS
3195
PIXELS
UPTO
9.3

60. Results:
• Vistascan exhibited the most extended useful exposure range ,
followed by RVG 6000 and Insight.
• RVG 6000 exhibited the largest TS values in all tube potential
settings except 70kV where Vistascan performed better.
• Insight performed better than Vistascan only at 60kV and 63kV.
• Vistascan performed better at 66 and 70kV, Insight at 60and 66kV
whereas RVG performed equally well at all tube potential settings,
except than at 52 and 70kV
Conclusions :
• The performance of all receptors tested was greatly dependent on
the exposure parameters and mainly on the kV-settings.
• Overall, the RVG 6000 offered the best image quality at doses
somewhere in between those required by the insight and the
Vistascan.
( E.Katsoni et al / Health (2011) 56-65 )

61. ADVANTAGES
• DOSE REDUCTION
• IMAGE MANIPULATION
• CONTRAST ENHANCEMENT
• MEASUREMENT
• 3-D CONSTRUCTION
• FILTRATION
• TIME SAVING
• STORAGE
• TELERADIOLOGY
• ENVIRONMENT FRIENDLY
DISADVANTAGES
• COST
• SENSOR DIMENSIONS
• CROSS INFECTION CONTROL
• MEDICOLEGAL
(JOURNAL OF ORTHODONTICS VOL.29, 2002, 66-69)

62. Technique Source Image Receptor
Computed tomography
(CT)
X-Rays Very Sensitive Crystal or
Gas Detectors
Magnetic Resonance
Imaging (MRI)
RF Waves Special Purpose Receiver
Coils
Scintigraphy Radioactive compounds Rectilinear Scanner and
Gamma scintillation
Camera
Diagnostic Ultrasound Ultra- High Frequency
Sound Waves
Transducers

63. •Hospital acquired infection (nosocomial infection) can cause
major illnesses, and may also be fatal.
•The leading cause of nosocomial infection is methcillin
resistant Staphylococcus aureus (MRSA).
•Image receptors are handled by many technologists per day
and if the proper hand sanitizing and cleaning of cassettes, etc
is not carried out the bacteria can colonize of these inanimate
objects for days depending on the type of bacteria.
•The CDC hand washing guidelines recommends that hands be
washed after every patient. It also recommends the cleaning
the image receptors and the radiographic cassettes in
radiology.

64. Haemophilus influenzae: Life span 12 days
MRSA : Life span 7days-7months
E. Coli : Life span 1.5hrs – 16months
Strep. Pyogens : Life span 3days - 6.5 months
Salmonella typhimurium: Life span 10 days- 4.5 yrs
Some of the clinically relevant pathogens that can live on dry
inanimate objects are as follows
(RADIOLOGIC TECHNOLOGY VOL. 81 NO. 6, July/August 2010)

65. • There has been a wide research on comparisons of the image
receptors used.
•The ALARA statement endorses that the doses should be As Low As
Reasonably Achievable.
•The technology now available now is paper free. It is theoretically
possible to store clinical notes/ photographs/ radiographs/ and study
models on disc and refer or consult online.
•Research is continuing into the development of a credit card sized
“SMART CARD” which could carry a person’s medical and dental
records.
•The future of digital imaging could include the testing and upgrade
of X-Ray equipment and software on-line.

66. • Oral Radiology : Principles and Interpretation (6th Ed.) - Stuart. C. White , Michael J. Pharoah
• Textbook of Dental and Maxillofacial Radiology By Karjodkar (2nd Ed.)
• The Journal of Contemporary Dental Practice, Vol 3, Number 4, Nov 15, 2002
• Journal of Orthodontics , Vol29, March 2002, 66-69
• International Journal of Health Sciences By Qassim University, Vol 4 (2), Nov 2010
• E. Katsoni et al / Health, Vol.3, No.1, 56-65, (2011)
• Radiologic Technology VOL. 81 NO. 6, July/August 2010