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Treatment for the jaundiced radiograph
TEACHING AID
Treatment for the jaundiced radiograph William H. Kelly, DDS
Correct processing of radiographs is indispensible in producing images of archival quality. However, errors often occur during processing, which in time, render films unsuitable for diagnosis, case presentation, or teaching. The most common of these errors are improper fixation and washing, which can ultimately cause a yellowbrown discoloration of the film emulsion. This discoloration may occur over the entire surface or may be limited to patchy areas and may not become evident until several months or even years after processing. The chemistry of fixation is responsible for the aforementioned effects. Immersion of the developed film in a fixing bath removes undeveloped silver bromide salts. If the fixer is near exhaustion, a high concentration of complex silver thiosulfate compounds are in solution and are retained by the emulsion. Even thorough washing may be ineffective in eliminating the
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compounds. Decomposition to silver sulfide occurs with time and causes a yellow stain. Silver sulfide stains can usually be removed by immersion of the radiograph in a fixing bath if the acidity has been increased with citric acid? The solution can be mixed by taking one cup (8 oz) of a fresh working solution of ammonium thiosulfate dental fixer (Kodak G B X or equivalent) and stirring in tA to 89 teaspoon of anhydrous citric acid. The jaundiced radiograph should be gently agitated in the solution for 15 to 60 seconds. As soon as the stain is removed, the film should be washed thoroughly in a running water bath for 20 to 30 minutes. Several films may be treated with one batch of solution. The chemicals appear to precipitate with time; therefore, the solution should not be stored. Results appear to be permanent and without noticeable degradation of image quality. However, excessive
treatment may be harmful, and a cautious approach should be taken. Heavy brown stains and severely yellowed films are less amenable to treatment. To avoid the need to remove stains, proper initial processing of films is strongly emphasized. The author thanks John M. Lynn, technical services specialist, Eastman Kodak Co, for technical advice and Mrs. June Ujcich for her assistance in manuscript preparation. Dr. Kelly is chief, endodontics section, Veterans Administration Medical Center, Wood (Milwaukee), Wisconsin, and associate clinical professor, Marquette University School of Dentistry, Milwaukee, Wis. Requests for reprints should be directed to Dr. Kelly, Veterans Administration Medical Center, 5000 W National Ave, Wood, Wis 53193.
References 1. Preservation of Photographs, ed 1. Rochester, Eastman Kodak Co, No. F-30, 1979, p 52.
Treatment for the jaundiced radiograph William H. Kelly, DDS
Correct processing of radiographs is indispensible in producing images of archival quality. However, errors often occur during processing, which in time, render films unsuitable for diagnosis, case presentation, or teaching. The most common of these errors are improper fixation and washing, which can ultimately cause a yellowbrown discoloration of the film emulsion. This discoloration may occur over the entire surface or may be limited to patchy areas and may not become evident until several months or even years after processing. The chemistry of fixation is responsible for the aforementioned effects. Immersion of the developed film in a fixing bath removes undeveloped silver bromide salts. If the fixer is near exhaustion, a high concentration of complex silver thiosulfate compounds are in solution and are retained by the emulsion. Even thorough washing may be ineffective in eliminating the
424
compounds. Decomposition to silver sulfide occurs with time and causes a yellow stain. Silver sulfide stains can usually be removed by immersion of the radiograph in a fixing bath if the acidity has been increased with citric acid? The solution can be mixed by taking one cup (8 oz) of a fresh working solution of ammonium thiosulfate dental fixer (Kodak G B X or equivalent) and stirring in tA to 89 teaspoon of anhydrous citric acid. The jaundiced radiograph should be gently agitated in the solution for 15 to 60 seconds. As soon as the stain is removed, the film should be washed thoroughly in a running water bath for 20 to 30 minutes. Several films may be treated with one batch of solution. The chemicals appear to precipitate with time; therefore, the solution should not be stored. Results appear to be permanent and without noticeable degradation of image quality. However, excessive
treatment may be harmful, and a cautious approach should be taken. Heavy brown stains and severely yellowed films are less amenable to treatment. To avoid the need to remove stains, proper initial processing of films is strongly emphasized. The author thanks John M. Lynn, technical services specialist, Eastman Kodak Co, for technical advice and Mrs. June Ujcich for her assistance in manuscript preparation. Dr. Kelly is chief, endodontics section, Veterans Administration Medical Center, Wood (Milwaukee), Wisconsin, and associate clinical professor, Marquette University School of Dentistry, Milwaukee, Wis. Requests for reprints should be directed to Dr. Kelly, Veterans Administration Medical Center, 5000 W National Ave, Wood, Wis 53193.
References 1. Preservation of Photographs, ed 1. Rochester, Eastman Kodak Co, No. F-30, 1979, p 52.