Radiographic Processing

• Correct processing of radiographs is a key factor in good radiography. Correct processing is not an expensive procedure; however an understanding of basic fundamentals and needs is required to avoid unnecessary that might destroy the detail of a radiograph. The first consideration will be x-ray film and its processing.

• The latent image produced when a radiographic film is exposed to a beam of X-ray can be visualized and examined only after the film has been suitably processed in the dark room .

• However, the most detailed and careful radiographic technique in the X-ray room can be wasted unless it is matched by similar high standards in the dark room. It is essential that the dark room should be suitably maintained and used. 

• The exposed film is removed from the cassette in a safely lighted dark room and placed in stainless steel processing frame. It is then immersed in a tank of developer which completes the reduction of the exposed grains of silver halide, and makes the image visible.

• After a specified time the film is taken out of the developer, rinsed in water and then immersed in the fixer bath. This solution removes the undeveloped emulsion.

• The image can be inspected in white light. after 10 minutes in the fixer bath the film is washed in running water for half an hou, to remove the processing chemicals and then hung up to dry.

Top Details of radiographic processing:

Storing unexposed x-ray film it should be stored in cool dry place protected from radiation in upright position.

Loading the X-ray film

• The X-ray film should be correctly positioned within the cassette by touching only the corners.

• The central portion should never be touched. Then the cassette should be closed and locked.

Storing x-ray cassettes

• Loaded x-ray cassettes should be stored in an upright position in cool dry place within the dark room.

Removing the x-ray film from the cassette

• The processing room should be darkened except for the safe light. Great care must be taken in removing the x-ray film from the cassette to prevent damage of the intensifying screens. The workers fingers should not touch the screens of the cassette. Rubbing the film across the end of the cassette must be avoided to avoided black pressure scratches on the developed radiograph.

Developing X-Ray Film

• The processing solutions should be stirred before processing the film. The x-ray film should be placed in the developing solution and agitated briefly to remove any air bubbles.

• It should be left in the developer for five minutes, if the tem­perature is 68° F. If the temperature varies from 68° F the developing time should be varied accordingly. Below 60° F, developing chemical are quite sluggish casing under development and inadequate fixation.

• A bone 75°f developing chemical work too rapidly causing fogging and too much softening the emulsion chemicals.

Top Time-Temperature Variations for Film Developing

• The developing chemicals reduce the exposed silver halides in the emulsion to me­tallic silver, which is black. The increase in intensity of light from the intensifying screens causes more of the silver halides to turn to metallic silver, thus giving the various shades of gray and black on the developed radio­graph.

• Two forms of developing chemicals are used, one a liquid and the other a powder. Liquid chemicals are more convenient, the powder variety may disseminate powder dust throughout the room.

• The developing solution should be tightly covered when not in use to reduce oxida­tion. The solution should be discarded and replaced after three months of use because oxidation and accumulation of gelatin sludge and other impurities will cause poor development. A more practical method of determining it the developing solution should be discarded is to notice the color. As the solution weakens it first turns yellow, then brown. When it turns brown, indicating exhaustion, it should be replaced.

• X-ray film should be quickly removed from the developer and, in one motion placed into the post-developer water rinse. The developing solution should not be allowed to drip from the film back into the developer tank. The developing solution on the film will be nearly exhausted and a certain amount of developer should be removed each time to reduce the level so that developer replenisher solution may be added periodically. This keeps the developer at the proper level and at the correct chemical strength.

• Reloading the Cassette:

• During the time that the x-ray film is in the developer the cassettes should be reloaded as previously described.

• Top Post-development Rinse

• The post-development rinse, which ordinarily will take 30 seconds, should be circulating clean water. The rinsing process can be shortened by continually agitating the film. After the rinse is completed the film should be drained to prevent excess dilution of the fixer.

• Clearing and fixing X-ray Film

•  After its removal from the rinse, x-ray film should be placed in the fixing solution and agitated for 15 seconds. This helps prevent streaking and staining of the finished radiograph and hastens the fixation process.

• The temperature range for fixation should be the same as that for development, with 68° F optimum. The developing and fixing solutions should have the same tempera­tures to avoid unevenness of development and reticulation of the final radiograph.

• Final Washing of the Radiograph

• Adequate washing prevents discoloration it should be performed in running water at 68 F. washing for 20 minutes is adequate.

• Top Drying the radiograph

• The radiograph may be dried in open air or in an automatically heated, circulating air dryer fresh fixer solution hastens drying. If temperature of fixation is above 75^o F, drying time will he markedly slower due to swelling of the emulsion.

• Storing Radiographs: 

• Processed radiographs should have the corners cut off and be placed in a properly labeled envelope. The envelope should be stored in an up­right position in a storage bin. A numbering system should be used so that radiographs can be easily found.

• Automatic processing

• Reliable short time automatic processors are available. It should be 90-seconds processor because the reliability and reproducibility is as good as these for the slower processors.

• Where large number of radiographs have to be handled, automatic processing reduces the time and labor needed and results in a consistent end product . However, the cost of the initial equipment, of maintenance and the increased amount of chemicals required would seldom justify its use in veterinary practice.

• Top Hanging x-ray film

• X- ray film should be grasped only at the corners and inserted into the clips of the film hangers and locked in place. The upper corner of the film grasped and a Hached to the top clips. The film now ready to be placed in the developing tank.

• The clips of the film hanger should be cleaned periodically to prevent an accumulation of chemicals that may rundown on the film during processing and cause streaks.    

• Manufacturers specify the correct type.

• Two forms of safe-light can be used in the radiographic dark room.

• Direct: a diffused light shines directly over the work point, such as the dry and wet bench.

• Indirect: the filtered light is directed up to the ceiling where it is reflected over the room.

• Safe-light efficiency: Safe-lights should be placed so that the work of the dark room can be done without fumbling . where the dry and wet benches are separate , a small direct wall light should be provided for each. Top