1. Image receptors
Priyankesh
1st year post graduate
department of oral medicine and radiology

2. CONTENT
 INTRODUCTION
 HISTORY
 TYPES OF IMAGE RECEPTORS
 Radiographic film
-direct action film
-indirect action film
 Digital receptors
 Conclusion
 references

3. INTRODUCTION
• Image refers to picture or reflection of an object.
• Receptor means anything that respond to a stimulus.
• IMAGE RECEPTOR - a medium that changes X- ray beam into a visible image.

4. History
 EARLY 1900 – glass plates wrapped in black paper
 1913 – hand wrapped cellulose nitrate films
 1924 – cellulose triacetate films
 1960 – polyester base
 1980 – digital radiography ( research and development)
 1990 – CCD based imaging
 2000 – only digital imaging

5. FIRST “FILM”
GLASS PLATES
CELLULOSE NITRATE
HIGHLY FLAMMABLE
EASILY TORN
RESPONSIBLE FOR
MANY FIRES IN
HOSPITAL BASEMENTS
CELLULOSE TRIACETATE

6. CLASSIFICATION OF X-RAY FILMS
• According to packaging
1. Single film packet
2. Double film packet
• According to coating of emulsion
1. Single coated
2. Double coated
• According to sensitivity
1. Direct action / non-screen film
2. Indirect action / screen film
• According to use
1. Intraoral films
2. Extra oral films
3. Duplicating films
4. Self developing film
• According to speed of film
1. Slow speed film
2. Fast speed film
3. Hyper speed G

7. DIRECT/ NON-SCREEN FILM

8. • Wrapper – non absorbent paper or plastic or soft vinyl
- two sides
• Tube side – pebbled or smooth surface, usually white
• Labeled side – usually two colors

9.  INFORMATION ON LABELED SIDE:
 - name of manufacturer
 - number of films enclosed
 - raised identification dot
 - speed of the film
 - statement regarding placement of film

10. COMPOSITION OF X –RAY FILM

11. • Base : transparent supporting material upon which emulsion is coated

12.  Emulsion: Sensitive to X rays and visible light, records the radiographic
image.
• Film emulsion can be on one side or both sides of base
(single emulsion / double emulsion)
• Protective overcoat layered on top of emulsion
• Emulsion is a gelatin containing the film crystals
• Emulsion is the “active” layer of film
• Made of mixture of gelatin & silver halide crystals (fluorine, chlorine, bromine, & iodine)

13. Latent image

16. • A type of film that is used to make an identical copy of an intraoral or
extraoral radiograph.
• Used only in darkroom setting
• Not exposed to x ray
• Emulsion is present on one side of the film
• Emulsion side – dull
• Non-emulsion side – shiny
• Does not have orientation dot
• Emulsion side of film must be in contact with radiograph to be
duplicated

17. CASSETTE

18. CHARGED COUPLE DEVICE
 Charge Coupled Devices (CCDs) were invented in October 19, 1969, by William S. Boyle
and George

19. CCD

22. COMPLEMENTARY METAL OXIDE
SEMICONDUCTORS
• Silicon-based semiconductors
• Electron hole pairs generated in pixels proportional to radiation dose
• Each pixel is isolated and directly connected to the transistor
• Transferred as a small voltage to transistor
• Transistors addressed separately, read by frame grabber
• Stored and displayed as a digital gray value

23. PHOTO STIMULABLE PHOSPHOR PLATES
• Photostimulable phosphor plates (PSP) absorb and store energy from x rays and then release this
energy as light (phosphorescence) when stimulated by other light of an appropriate wavelength.
• photostimulable phosphor material used for radiographic imaging is "Europium-doped" barium
fluorohalide..

25. FLAT PANEL DETECTORS

27. REFERENCES
• Oral radiology- principle and interpretation, -White and pharoah, 5th edition.
• Dental radiography, principles and techniques- Haring and jansen – 3rd edition