An evaluation of the effect of processing conditions on mammographic film contrast, fog levels and speed.
While it is well established that extended development times and temperatures will increase mammographic film contrast and speed (1), little work has been done to date in extending this work to encompass all common screen-film types and to study the effect of processing chemistry variations on contrast speed results. This paper reports on four locally available mammographic films which, after exposure in conditions that closely simulate clinical conditions, have been developed with four different development chemicals as a function of development temperature and time. Three development times were used (23, 32 and 42 seconds) in combination with four development temperatures (32, 34, 36 and 38 degrees). The results support the previously published result of increased speed and contrast with extending development time and temperature. It was further found that, for some film types, the film contrast varied significantly over film density when developed with extended processing. Other film types, however, maintained high contrasts over large film density ranges. In some cases the increased contrast was accompanied by elevated film fog levels. The development of mammographic films in non recommended chemistries produced varying results, mostly detrimental, which demonstrated that selection of development chemistry as well as optimal development times and temperatures, is critical for good film performance.
McLean
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University of Sydney, Faculty of Health Sciences, School of Medical Radiation Technology, Lidcombe NSW, Australia.
D015502:Absorptiometry, Photon; D005069:Evaluation Studies as Topic; D008327:Mammography / Q000295:instrumentation*; D011829:Radiation Dosage; D011856:Radiographic Image Enhancement / Q000379:methods*; D012996:Solutions; D013696:Temperature; D013997:Time Factors; D014962:X-Ray Film; D014963:X-Ray Intensifying Screens
D012996:Solutions