DARK ROOM PROCESSING(MANUAL AND AUTOMATIC PROCEESING).pptx

DARK ROOM PROCESSING

1. DARKROOM PROCESSING Girish H, MSc. MIT Radiological Technologist, NIMHANS

2. THE MANUAL PROCESSING After the expose the film will be processed in several steps, they are; Developing Rinsing Fixation Washing Drying

3. BASIC COMPONENTS: CHEMISTRY MIXING TANKS

4. THE MANUAL PROCESSING

5. DEVELOPER The function of development is to convert the latent image to a visible image by means of a developing solutions. The main function of the developer is reduce the exposed silver halide without harming the un-exposed silver halide.

6. POWDER FORM

7. LIQUID FORM

8. DEVELOPER SOLUTIONS The developer consists of following chemicals, they are; Elon or metol Hydroquinone Sodium carbonate or sodium hydroxide or sodium metaborate - Activator Potassium bromide - Restrainer Sodium sulphite - Preservative Glutaraldehyde - Hardener Developing agents

9. 1.Developing agent Hydroquinone or Metol are used as developing agent. Hydroquinone is slow acting & is responsible for the black shades. Metol acts rapidly & produce light gray.

10. 2.Activator Sodium carbonate or sodium hydroxide serves as an activator, which swells an gelatin, and produce alkalinity and control the pH.

11. 3.Restrainer Potassium bromide is used as restrainer, which is anti fogging agent. It decreases the fog, by protecting the unexposed crystals.

12. 4.Preservative Sodium sulphite is used as preservative. The preservative controls the oxidation of the developing agent, by air and other components.

13. 5.Hardener Glutaraldehyde acts as hardener, to control emulsion .swelling and softening

14. RINSING This is the next step after the developing, the film is suspended in the rinsing for 30 seconds . Rinsing partially stops the reaction of developer and neutralizes the alkalinity of the residual developer. Where the water must be kept circulating in order to remove all traces of developer from the film. Contamination by the developer would quickly deprive the fixer of its effectiveness and give rise to colour fog.

15. The main function of the fixer, is To remove the un-exposed and un-developed silver halides. To preserve the film image. To harden the emulsion so that it will not be easily damaged. FIXER

16. FIXER The fixer contains the following chemicals, they are; Sulphuric Acid or sodium metasulphite or acetic acid with sodium sulphite - Activator Sodium thiosulfate (hypo ) or Ammonium thiosulfate salts - Fixing agent White or blue Alum - Hardener Sodium sulphite - Preservative Acetate - Buffer

17. WASHING This is done to remove all chemical agents on the film in the running water. Because it will change the deposited black silver to brown silver sulfide. Washing requires running water and ordinarily it’s temperature is 20º C.

18. DRYING The final step in processing is to dry the radiographs. For this purpose hot-air drying cabinets are very useful. The drying temperature must be not exceed 35º C. The film must be hang in a dust free area.

19. FILM DRIER

20. METHODS OF PROCESSING There are three methods of processing, they are; Tray method Tank method Automatic processing method

21. THE TRAY METHOD: This method is used only in operation theatres. Here, developer and fixer are in the trays specially designed for the purpose. The processing time is 2 minutes for developing, rinsing, fixing. Solutions once mixed will lost for 1-2 months if preserved properly with lids on the trays.

22. THE TRAY METHOD:

23. THE TANK METHOD: This is the most convenient method and commonly used. In the darkroom, there is a master tank of masonry construction. In master tank the developer tank is extreme, next is rinsing tank and finally fixer tank. The remaining part of masonry tank (after the place occupied by 3 processing tanks) contains fresh running water for washing purposes.

24. THE TANK METHOD:

25. Most of modern medical imaging departments use automatic processors, most of those are daylight processors. THE AUTOMATIC METHOD:

26. AUTOMATIC DAYLIGHT PROCESSORS

27. AUTOMATIC DARKROOM PROCESSORS

28. AUTOMATIC DARKROOM PROCESSORS

29. MAINTENANCE OF SOLUTIONS Developer and fixer solutions lose their strength after use or prolonged storage even without use. This will results in lack of contrast and density of the radiograph, though they need very long duration for processing. It shall be noted that by increasing the radiographic technique up to a certain level (25% more than usual).

30. THE DARKROOM TECHNIQUE It is the main part of a radiological procedure. Many faults can be covered by darkroom techniques, such as over exposure or under exposure in radiography can be adjusted by under developing or over developing. So, the radiography begins in darkroom with the loading of film into the cassettes and ends in darkroom after washing the film.

31. FILM FOGS Film fogs occurs by following incorrect procedures, they are, Due to exposure to light Exposure to X-rays Chemical fogs Age fogs

32. DUE TO EXPOSURE TO LIGHT: Dark room is not light proof. Safelight contains too large bulb. Safe light housing or filter is cracked. Prolong exposure of film to safelight. Safelight series is incorrect.

33. EXPOSURE TO X-RAYS: Exposure to X-rays or other radioactive elements Note:– films should be shielded from radioactive material by sufficient thickness of led and/or distance.

34. CHEMICAL FOGS: By over developing By developing at high temperature By poor developing Prolonged and repeated inspection of film during development

35. AGE FOGS: Uniformly foggy film due to use of expiry date film or storage under improper temperature or humidity etc…

36. DARKROOM ARTEFCTS The artefcts can be occurs as stains , marks and defects . There are discoloration, that may be appear on a film at different intervals after processing, these can be avoided by the use of fresh solution and correct processing.

37. THANK YOU