Xray Darkroom and Equipments

1. FILM-SCREEN IMAGE ACQUISITION,
PROCESSING AND IMAGE ANALYSIS

2. 10 REASONS TO FAILURE
1. Poor people skill
2. A negative attitude
3. A bad fit
4. Lack of focus
5. A weak commitment

3. 10 REASONS TO FAILURE
6. An unwillingness to change
7. A shortcut mind set
8. Relying on talent alone
9. A response to poor information
10. No goals

4. Dark room

5. DARKROOM
WHAT IS DARKROOM? ---It’s
A scientific laboratory,
Where radiography
starts and ends.
DARKROOM DISEASE-
Hypersensitivity to
fumes
MAIN FUNCTION OF DARKROOM-To
prevent/protect film from
exposure to white light and
ionizing radiation during handling
and processing

6. What do you think is the
ideal darkroom setup?

7. DARK ROOM LAYOUT
1.) LOCATION
- In proximity/near to
exposure room
2.) SIZE
-15ft x 9.5 ft or greater
-200 radiographs/day
NOTE: Darkroom MUST
have a Wet and Dry
Section.
× 4 ft away from each
other, To prevent
contamination of the
dry section.

8. DARK ROOM LAYOUT
3. PROTECTS AGAINST
RADIATION
× Darkroom can be adjacent
to exposure room only if:
× HOLLOW BLOCKS: filled with
cement
× CONCRETE: greater than 6
inches
× WOOD: with 1.5 mm Pb

9. Ideal dark room
× A room should be set aside as a permanent dark room, ideally
with a floor area of not less than 10sqm.
× The room must be capable of being made completely
lightproof.
× It should not be damp or subjected to extremes of
temperature.
× Water and electrical outlets should be provided.
× Sufficient space to accommodate a dry bench , a wet bench
and a sink.

10. Ideal dark room
× Too large room is as undesirable as small room.
× Should be near the x-ray examination area.
× Should be well ventilated.
× The wall should be constructed of solid concrete (15 cm thick),
have a lead box inside to store boxes of unexposed films
currently in use.
× The wall should be constructed of solid concrete (15 cm thick),
have a lead box inside to store boxes of unexposed films
currently in use.

11. Ideal dark room
× The walls and roof should be painted by white or cream
enamel as such a paint acts as a good reflecting surface
for safe light.
× X-ray rotating warning light in hallway switched "on"
signaling that x-ray machine is operating

12. Dark room location
× Centrally located
× Serviced by hatches
from the adjacent
imaging room
× Away from damp or hot
areas
× Accessible in terms of
power and water supply

13. size
× Minimum floor area of 10 sq meter
× Ceiling height of 2.5 - 3 meter
× Size may be reduced depending
upon the department needs

14. Light proof
× The first requisite of a
processing room is the
exclusion of all external
white light when
radiographs are
processed.
× Photosensitive crystals
in film emulsions are
extremely sensitive
to visible light, and any
light leaking around a
door or window may
fog and ruin the films.
×
×

15. Light proof
× A door that can be
locked to avoid
accidental exposure
of film to white light.
× Alternatively a light
outside the door
indicating that the
darkroom is in use. When
the white light in the
darkroom is switched
off, the indicating light
outside automatically
goes on
×
×

16. Radiation protection
× Walls adjacent to the
radiographic room
should be shielded
with correct thickness
of the lead all the way
to the ceiling
× Walls adjacent to the
radiographic room
should be shielded with
correct thickness of the
lead all the way to the
ceiling
× 1.6 mm lead is mostly
used

17. floors
● Non-porous flooring
● Non-porous flooring
● Non-slip flooring
● Chemical resistant
● Stain proof
● Durable & easy to maintain
● Light coloured (low- light
working conditions)
● Asphalt tiles
● Porcelain tiles
● Clay tiles
● Plastic tiles may
be used in the dry
dark- rooms

18. Walls / ceiling
● Light in colour to reflect as much light as
possible onto the working surface
● Easy to wipe or clean
● Covered with chemical resistant materials
● Special paints, varnish, ceramic or plastic
wall

19. Ventilation and heating
× Satisfactory working conditions for the staff
× Good film handling and storage conditions
× Efficient automatic processor performance
× Relative humidity is maintained at around 40-60
%
× Room temperature maintained between 18-20
degree celsius

20. Ventilation and heating
× A minimum of 10 air changes per hour
× All of these conditions can be achieved by using a
good air-conditioning system
× Alternatively, fairly satisfactory ventilation can
be achieved by using an extractor fan sited
higher than and diagonally opposite a second
fan, the latter being so placed as to obtain fresh
and filtered air from outside.
×

21. Types of entrance

22. Types of entrance

23. Dark illumination
× WHITE LIGHTING
× SAFELIGHTING

24. WHITE LIGHTING
× For inspection & maintenance of cassettes &
screens
× Cleaning of work surfaces
× Servicing of equipment
× Sited close to the ceiling
× Moderate in intensity
× Preferably centrally placed

25. Safelight
DIRECT SAFE LIGHTING:
- Light from safe lamp
directly falls onto the
work surface
-Minimum distance of
1.2 m/ 4 feet from the
working surface
Best for loading &
unloading areas

26. Safelight
INDIRECT SAFELIGHT
-Directs the light towards the ceiling which reflects
light back into the room
Is intended to provide general illumination of the dark
room
Suspended atleast 2.1 m above floor level

27. How Does A Safelight Work?
When white light is passed
through coloured filters,
certain wavelengths (or
colours) are absorbed by
the filters, whilst those
wavelengths, which
correspond to the colour of
the filters will be
transmitted.

28. HOW DOES A SAFELIGHT WORKS?
Making the correct selection of
safelight filter (matching the filter to
the film), means choosing a filter,
which will transmit a colour to which
the film is relatively unresponsive,
whilst stopping all light to which the
film is most sensitive.

29. HOW SAFE IS SALELIGHT?
× No safe lighting is completely safe; all films will become
significantly fogged if exposed to safelights for long enough.
× are not perfect absorbers of the undesirable wavelengths
and, in truth, all films have some sensitivity to all
wavelengths.
× This is because safelight filters Thus, the intensity of
illumination and the film- handling time must be kept to a
minimum if significant fogging is not to occur.

30. Safelight illumination test
× Place a coin on a small piece of photo
paper. Let it sit for 20 min. and develop
the paper. If you see the outline of the
coin, your safelight isn't safe
×

31. Safelight illumination test
NOTE: If the safelight is not safe, you should do
one of the following to correct the problem:
1. Replace the bulb with one of lower wattage
2. Raise the safelight lamp higher from working
surface
3. Check the filter - may be cracked or broken

32. DARK ROOM EQUIPMENTS

34. SHARE YOUR
ASSIGNMENT

35. DARK ROOM EQUIPMENTS
● Film cassettes:
○ A cassette is designed to hold the x-ray film and
intensifying screens in close contact.
○ The front face which is of aluminum or plastic, faces the
tube while the other side have a sheet of lead to
absorbed back-scatter screens and cassettes are of
course made in various sizes to correspond with
standard film sizes.

36. DARK ROOM EQUIPMENTS
× Mounting intensifying screens in the cassette
× Intensifying screens should be never be loose but must be
properly mounted into the cassette.
× Because certain adhesives interact with the screens it is
advisable to use only the
× double-sided tape provided by the manufacturers.

37. DARK ROOM EQUIPMENTS
● The care of cassettes
○ Do not drop them on a hard floor
○ Do not trap the edges of the screens when the cassette is
closed
○ Cassettes should be kept clean and there is always the
danger of blood or urine leaking to the inside of the
cassette. When a cassette must be placed in a dirty
situation put it in a plastic bag.

38. DRY BENCH
● The dry bench is where the cassettes are unloaded and recharged
with fresh film. It must be impossible for splashes of developer to
reach the dry bench surface.
● The top of the dry bench must be large enough to accommodate
the largest cassette in use when opened out.
● The top surface should be either of wood or linoleum. Plastic
laminates are not recommended because they hold static charges
of electricity which can cause marks on films.
● It is usual to store film boxes, especially those in current use ,
beneath the dry bench , either in a cupboard ( protected if near
an X-ray set ) or in a film hopper.

39. WET BENCH
× The wet bench is where the processing of the films is
carried out.
× The usual method is to use a set of tanks holding
developer rinse water and fixer , and a larger tank
for washing the films.

40. DARK ROOM DRY BENCH SYSTEM

41. AUTOMATIC PROCESSOR

42. MANUAL PROCESS UNIT

43. AUTOMATIC PROCESSOR

44. PROCESSING CHEMICALS

45. Hangers used for suspending films during processing

46. CASSETTES

47. FILM BIN

48. PASS BOX

50. Automatic
processor

51. asynchronous
Read the ff:
- Dark room
- Setup, equipments, requirements
- Safelight
- Cassette and Intensifying screen
- Automatic and manual processing
- Film and sensitivity

52. Auto-Processor Top View

53. 4 steps of processing
1. `Developing
2. Fixing
3. Washing
4. Drying

54. developing
-Formation of Image

55. fixing
-Stopping the development permanent
fixing of image on film

56. washing
Removal of residual Fixer

57. drying
-Warm Air Blowing over film

58. ImpoRtant Major parts of auto processor
× The Film Feed Section
× Transport System
× Temperature Control System
× Recirculation System
× Replenishment System
× Dryer System
× Electrical System

59. The Film Feed Section
As a film is fed to the processor, so the cycle of events
listed below is initiated:
-Drive motor energized (to turn the rollers).
-Developer and fixer replenisher pumped into tanks.
-Dryer heater energized.

60. The film feed section
Wash water flow rate boosted. Film signal delay timer
activated (audible signal which will sound
1-3s after the trailing edge of the film has passed the
entry rollers, to let the operator know that the next film
can be fed to the processor).

61. The film transport section
A system of rollers that moves the film through
the developer, fixer, washing and drying sections
of the processor.
Also acts as a squeegee action to remove excess
chemicals from the film.

62. Make up of the Transport System
1. Entrance roller or detector roller
2. Vertical or Deep racks (transport racks)
3. Crossover assembly
4. Squeegee assembly

64. Entrance Roller Or Detector Roller
-Entrance rollers grab film
and draw it into developer
-Entrance rollers separate slightly, film passes
between rollers activating microswitch
controlling replenishment of chemicals
-When film is completely in developer tank, bell
ring or light flicks on – safe to turn on light

65. Vertical Deep racks (transport racks)
× Moves film into and
through solutions and
dryer
× Uses a turn around
assembly at the bottom
of the tank to turn film
direction upward.

66. Crossover assembly
-Moves film from
developer to fixer tank
and from the fixer to the
wash tank
-Forces solutions from
film back into the tank it
is coming from.

67. Squeegee assembly
-Moves the film from the
wash tank to the dryer
-Squeegee action
removes excess water
from the film.

68. Transport system (rollers)

69. Water system
● 2 Functions:
○ Washing the Film
○ Temp Control

70. washing
-Removes the last traces of
processing chemicals and
prevents fading or
discoloration.
-This enables long term
storage capability

71. Temperature Control system
Maintains
developer,
fixer &
dryer
temperatur
e

72. Processing Temperatures
Developer 35° C
Fixer 35 ° C
Wash 32-35 ° C
Dryer 57 ° C

73. Circulation or Recirculation or Filtration System
Agitates developer solution
Removes reaction particles by the use of a filtration system
Helps stabilize developer temperature.
Agitation and circulation
Agitation keeps solutions in contact with a heater element in the
bottom of the tank and prevents layering of chemicals
Maintains developer temperature
Heating element is controlled by a thermostat

74. Recirculation system
× Controlled by recirculation pumps that agitate solutions
to keep them mixed to maintain constant temperature
× Circulation of water required to wash residual fixer (12
litres per minute)

75. Replenishment System
× Fixer & developer levels drop as films
processed
× System replaces lost chemicals
× Microswitch of entrance rollers starts
replenishment pump – stops when film exits
entrance rollers

76. Replenishment system
-Typical replenishment rates: 60-70 mls of developer,
and 100-110 ml of fixer for every 14 inches of x-ray film
(per 35 x 43cm crosswise film)

77. Types of replenishment
-Volume Replenishment
A volume of chemicals are replaced for each film that
is processed.
-Flood Replenishment
Periodically replenishes chemicals regardless of the
number of films processed

78. Dryer system
-Dries the film before its removal for viewing
If not dry, difficult to hang on viewing box
-Consists of blower, ventilation ducts, vented dryer tubes
& exhaust system
-Blower draws in air from room and passes it over
heating coils
-Heated air enters ventilation ducts & dryer tubes & then
blows over film
-Moist warm air vented

79. Processing rates
× Amount of time it takes a
film to go through
processor – ranges from
45-210 seconds
× Film manufacturers
determine temperatures
and replenishment rates
Processing Times
Developer 20-25secs
Fixer 20
Wash 20
Dryer 25-30
Travel Time 10
Total Time 90 sec

80. DAYLIGHT AUTOMATIC PROCESSOR

81. DAYLIGHT AUTOMATIC PROCESSOR
× Enable film to be processed without need for
darkroom
× Special cassettes
× Increase in department efficiency, no need for
special darkroom staff
× Disadvantages
× Cost
× Mechanical breakdowns

82. Automatic Film Processing: Benefits
Compact size
Faster
Density and contrast is constant
Time and temperature controlled
Produces dry radiograph immediately

83. Automatic Film Processing: Disadvantages
-Artifacts caused by rollers.
Expensive and requires maintenance.
Manual processing required as a back up in
case of break down

84. Maintenance
To maintain quality, attention needed in 3 areas:
Quality control
Processor cleanliness
Basic operation

85. Asynchronous
1. Memorize Gurney and Mott Theory
2. Read and understand Bushong Chapter
12 Screen Film Radiography
3. Review all components of Fixer and
Developer together with their functions