2. RADIOGRAPHIC FILM
● The x-ray film help us to record the
Information regarding the object through
Which the x-ray passes and hence they
Greatly help in diagnosis and treatment of
Patient problem.
● Image recorded on film is caused by
Exposure to photons.
3. FILM CONSTRUCTION
● X-ray film consists of an emulsion -gelatin containing radiation sensitive
silver haide crystals and a transparent, flexible base.
● An x-ray film has 4 layers
○ Base
○ Subbing layer
○ Emulsion layer
○ Super coat
4. FILM BASE
● A film base is a transparent,
flexible,and tough substrate
that supports the film
emulsion.
● Earlier , cellulose triacetate
was used.
● Nowadays,polyster made
from polyethylene
terephthalate resin is used.
5. FUNCTION OF
FILM BASE
● Provide support to the
emulsion layer
● To transmit light so, that an
image can be viewed.
6. Characteristics
of film base
● Transparent
● Strong
● Flexible
● Uniform in thickness
● Dimensionally stable
● Impermeable to water and
processing solution
● Non flammable
● Chemically inactive
● Uniform in colour
7. ● Sheet film :0.18mm
● Flurographic roll film:0.08mm
Thickness of
base
8. SUBBING
LAYER
● It is present between base and the
emulsion layer.
● It is made by the mixture of gelatin
soln
and solvent of film base.
Subbing layer is required due to:
● To prevent any separation of the
emulsion layer from the base during
processing.
9. EMULSION
LAYER
● the emulsion layer contains
light-sensitive compounds
that capture images when
exposed to light.
● The sensitive emulsion
consist of silver halide
crystals suspended in
gelatin.
● Duplitized x-ray film
:emulsion is coated on both
sides of the base.
10. SUPERCOAT
● This is a thin layer of clear
gelatin,which is applied to
the emulsion.
It has 2 prime function
● To protect the sensitive
emulsion from the effects of
light pressure or abrasion
which might occur during
use.
● To provide suitable surface
characteristics.
11. Non-curl
backing
● Present in single -sided emulsion film
only.
● Because the film emulsion layer swell
during processing the film as a whole
will have tendency to curl .
● In order to prevent the curling
tendency with single sided emulsion
film,the emulsion layer is balanced by
coating the base on the opposite
side.
12. ANTI-HALATION
LAYER
● When the image is formed by
light,some of the light incident on
the film will pass through the
emulsion layer and reach the
base.
● Depending on the angle at which
the light strike the film,it may
either passout of the base /air-
interface at the back of the film or
totally reflected back towards the
emulsion.
● Such reflected light will produce a
diffuse image or ‘HALO’ around
the proper image.
● This phenomenon is known as
‘HALATION’ .
16. SCREEN TYPE
FILM
● Most commonly used.
● Sensitive to blue light emitted
by intensifying screen and
direct action of x-rays
● Film used in conjunction with a
cassette fitted with single
intensifying screen
19. DUPLITIZED EMULSION FILM
Non - screen type film
● Intra oral dental film
● Kidney surgery film
● Radiation monitoring film
Screen type film
● Used with intensifying screen
20. SINGLE
EMULSION FILM
● Screen type film
● Photoflurographic film
● Cathode ray tube
photography
● Duplication film
● Substraction film
● Laser imaging film
22. DIRECT EXPOSURE TYPE FILM
● Also known as envelope wrapped or non -screen film because of its exposure
to x rays only.
● Each film is individually wrapped in paper and mounted with a stiff and for
support inside a moisture - resistant paper envelope.
● On-screen film are used because of their superior resolution compared to
screen film system.
23. INTRA ORAL DENTAL FILMS
TYPES:
● PERIAPICAL : 31×41mm (for single or groups of teeth)
● OCCLUSAL :57×76mm (for imaging mandibles or maxilae)
The wrapping of dental envelope package includes:
● The lead -foil insert act as an attenuation of back scattered radiation arising
from the intra oral structure.
● The outer water- proof packets protects the film from the moisture and the
paper insert provide some protection from pressure.
24. KIDNEY SURGERY FILM
● It is designed to enable a radiographic exposure of the kidney to be
made extra-abdominally during surgery for the removal of renal stones
● The shape of the film facilitates easy placement of the kidney and renal
vessels.
● Each packet contains 2- films on with fast emulsion and other with flow.
25. SCREEN TYPE FILM
● These film are used in conjunction with pairs of intensifying screens.
● The latent image being produced mainly by light emission from the
screen phosphurs.
26. ● A wide range of different manufactural film are available:
BLUE SENSITIVE (Monochromatic)
GREEN SENSITIVE (orthochromatic)
28. Screen type film
● Film used in conjunction with a cassette fitted with a single intensifying
screen.
● Capable of demonstrating microcalcification in soft tissues.
APPLICATION
● Mammography
29. Photoflurographic film
● These are film used to record the image produced at:
The output phospher of an image intensifier tube
The fluroscent screen of a camera system such as miniature
radiography of the chest.
All film has a single emulsion and an anti halation layer. The
emulsion are orthochromatic.
30. Uses of single emulsion film
● Used in ultrasound, CT,MRI, Nuclear medicine and digital subtraction
Image
● Films are used in conjunction with CRT
● Emulsion are orthochromatic of medium to high contrast
● Sizes commonly used are 10”
×8” and14”×11”
31. POLOROID FILM
● Mainly used in recording ultrasound scan images.
● Poloroid film pack comprises of a positive and negative sheet
● The photographic sheets are connected by a paper linkage
● After exposure the paper tab is pulled,so bringing the exposed surface
of a negative sheet into close with a positive sheet.
