it is brief review about x ray film and its parts x ray film,its layers and some littlr history about x ray film

1. MAAJID MOHI UD DIN MALIK
LECTURER COPMS ADESH UNIVERSITY
BATHINDA,PUNJAB
X-RAY FILM

2. INTRODUCTION
 It is a photographic film used to make X-
ray pictures.
 The X-Ray films, help us to record the
information regarding the object (tissue)
through which the x- rays passes & hence they
greatly help in diagnosis, & treatment of the
patient problem.
 Image recorded on film is caused by exposure
to photons.

3. HISTORY
 The first x-rays were recorded on glass
plates.
 These were coated with emulsion on one side
only.
 The exposure dose was quite high.
 In 1839, the phenomenon of development
was discovered by Louis Daguerre

4. CONT…
 One year later, it was discovered that
treating exposed silver chloride paper with
sodium chloride would make the image
permanent.
 Nitrocellulose based film was used in
1914 for recording x-rays.
 This film was single-emulsion but was
quiet flammable

5. CONT…
 It was later discovered that
double-emulsion responded
to x-rays faster.
 In 1924, safety film made of
cellulose triacetate replaced
the nitrocellulose based film.

6. COMPOSITION

7. X-RAY FILM CROSS SECTION

8. BASE
 It is a transparent supporting material.
 POLYESTER POLYETHYLENE
 Thickness - 0.18 mm

9. IDEAL PROPERTIES BASE MATERIAL
 Structural support for fragile emulsion.
 Low light absorption : Should not produce
visible pattern on the radiograph.
 Flexible, thick, & strong.
 Dimensional stability :Maintain size and shape
during processing, handling and storage.
 Non- Flammable.

10. TINTEDBLUE FILM
 Triacetate and Polyester are clear and colorless.
 Adopted in 1933, blue tint was added to the x-ray
film in an effort to produce a film that was “easier” to
look at.
 Causes less eye strain.
 Blue tint can be added to either to the base or to the
emulsion.
 All present x ray films are blue tinted.

11. FUNCTIONS OFBASE
 Provide support for emulsion layer.
 To transmit light.

12. ADHESIVELAYER
 Also called subbing layer or Substratum layer.
 Made of mixture of gelatin solution and solvent of
film base.
 It keeps emulsion layer and base adhered to each
other during coating stage and processing.
 Provides uniform surface over which the emulsion
can be coated uniformly.

13. EMULSION LAYER
 Has 2 principle components –
I. Silver halide grains
II. Vehicle matrix
 It consists of a homogeneous mixture of
gelatin and silver halide crystals.
 In typical emulsion 90 to 99% is AgBr and
about 1 to 10% AgI

14. CONT…
 The presence of AgI produce an
emulsion of much higher
sensitivity than a pure AgBr
emulsion.
 It also contains traces of sulfur.

15. HOWSILVER HALIDECRYSTALS ARE MADE… ???
Dissolve Metallic silver in nitric acid.
TO FORM
Silver nitrate
BY MIXING
silver nitrate + KBr = Ag-Br + potassium
nitrate

16. CONT…
 Silver halide in a emulsion is in the form of small crystals.
 Silver halide crystals may be tabular, globular, polyhedral,
or irregular in shape.
 Crystal size might vary from
 1.0 –1.5 microns in diameter with
about 6.3 x 1010 grains per
centimeter of emulsion.

18. CHEMICAL SENSETATION
 Chemical sensitization of the crystals are produced by
adding allylthiourea, a sulfur containing compound to
the emulsion , which reacts with silver halide to form
silver sulfide. This Silver Sulphide is usually located on
surface of the crystals and is referred as “sensitivity
speck”. It is the sensitivity speck that traps electrons to
begin formation of the latent image centers.

19. Latent image

20. THE LATENT IMAGE
 Remnant radiation interacts with the silver
halide crystals
 Mainly by the photoelectric interaction
 The energy deposited into the film is in the same
pattern as the subject that was exposed to
radiation
 This invisible image is known as the latent image

21. CONT…
 A latent image on photographic
(radiographic) film is an invisible image
produced by the exposure of the film to
light (radiation).
 By chemically processing the latent image
it is made visible known as the manifest
image.

22. FORMATION OF LATENT IMAGE
 Metallic silver is black, so it is this metallic silver
that produces black areas on a developed films.
 Exposure of silver-iodo-bromide grains to light
photons emitted by screen / direct x-ray exposure
initiates the formation of atomic silver to form a visible
pattern.

23. GRAIN SIZE AMD DISTRIBUTION
GRAIN SIZE and DISTRIBUTION affects the following:
 SPEED: The bigger the average grain size, the higher the
speed of the film.
 CONTRAST: Affected by size distribution. The more
available in the film, the lower the contrast.
 GRAININESS: Graininess is the apparent clumping of the
crystal as seen on the radiograph. The bigger the crystal,
the higher the graininess of the film.

24. GELATIN
 Gelatin is used as the suspending medium
and binding agent for the silver halide
particles.
 It comes collagen fiber in which primary
source are the cartilage, skin and the protein
matrix (ossein) of bone of animals.

25. WHYWEUSEGELATINAS BINDER…?
 It is a medium in which SILVER NITRATE and
SODIUM BROMIDE can react and the resulting
AgBr get finely and evenly dispersed and remain
suspended.
 In warm state it can be easily spread on the film base.
 On cooling, it sets firmly on the base as gel.
 It is flexible and does not crack easily on bending.

26. CONT…
 It is optically transparent .
 Gelatin does not react chemically with the silver
halide .
 It is porous so the processing chemicals can
penetrate to the silver halide crystals.
 Some of the constituents in gelatin enhances the
activity of Silver bromide and some act as
antifoggant.

27. SUPERCOAT (OVERCOAT)
Protective layer of gelatin
 Provides sturdiness to unexposed radiographic film.
 Antistatic
 Reduces damage from scratches, pressure, or
contamination during storage, handling and
processing.
Super coating

28. FEWADDITIVES
 Preservative – Phenol as bacteriocide
 Silver iodide – To extend sensitivity towards blue
range.
 Some dyes may extend Colour sensitivity further
 Glycerin to make the emulsion pliable
 Saponin –To make the emulsion receptive to the
processing chemicals
 Alcohol – To prevent frothing during coating

29. TYPES OF FILMS
According to SPEED –
 Slow film
 Fast film
 Hyper speed

30. ACCORDINGTOTHEIR USES–
 Intraoral films
 Extraoral films
Accordingto emulsionlayer -
 Single coated
 Double coated

31. ACCORDING TO PACKAGING
 Single film packet
 Double film packet

32. TYPES OF X RAY FILMS- BASED ON THEIR APPLICATION
Screen Films
 Most commonly used
 Sensitive to blue light emitted by intensifying
screens and direct actions of x-rays.
 Used in cassettes with intensifying screens
 High speed.

33. NON-SCREEN / DIRECT EXPOSURE FILMS:
 Has thicker coat of emulsion used without
intensifying screen.
 Depends mainly on action of x-ray.
 Four times faster than that of screen films so
requires 1/4th exposure only.
 Must be manually processed because of thick
emulsion.

34. USES :
 In limb radiography.
 To detect intra-ocular foreign body.
 In dental with intra-oral cardboard.

35. MAMMOGRAPHY FILM:
 Single coated
 Fine grain
 Slow speed
 High contrast
 Designed to be used with single intensifying screen
 Combination must be fast to deliver minimum
dose to the glandular tissue.

36. WHAT IS SPEED OF X-RAYFILM…???
 It is defined as the amount of the radiation
required to produce the radiograph of adequate
density.
 Slow film – Require more exposure & vice versa.
Factors affecting film speed –
 Size of crystals
 Shape of grains
 Thickness of emulsions

37. DIFFERENCEB/WSINGLECOATEDANDDOUBLECOATED X-RAYFILM
Characteristic Single coated Double coated
Emulsion layer One side Both side
Patient Radiation dose More Less
Radiographic detail More Less
Average gradient (G) Very less more
Parallax effect No yes
Contrast Less more