Light sensitometry of mammography films at varying development temperatures and times

Kodak MinR-2000 mammography film is widely used for mammography imaging. The sensitometric indices like base plus fog level (B + F), maximum optical density (OD(max)), average gradient (AG) and speed of this film at varying development temperatures and times were evaluated using a light sensitometer. Totally 33 film strips were cut from a single Kodak MinR-2000 mammography film box and exposed in a light sensitometer operated in the green light spectrum to produce a 21-step sensitometric strip. These exposed film strips were processed at temperatures in the range of 32°C-37°C in the step of 1°C and at processing times in the range of 1-6 minutes in the step of 1 minute. The results of the present study show that the measured base plus fog level of the mammography film was not affected much, whereas significant changes were seen in the OD(max), AG and speed with varying development temperatures and times. The OD(max) values of the film were found in the range of 3.67-3.76, AG values were in the range of 2.48-3.4 and speed values were in the range of 0.015-0.0236 when the processing temperature was varied from 32°C to 37°C. With processing time variation from 1 to 6 minutes, the observed changes in OD(max) values were in the range of 3.54-3.71, changes in AG were in the range of 2.66-3.27 and changes in speed were in the range of 0.011-0.025. Based on these observations, recommendations for optimum processing parameters to be used for this film are made.