Light sensitometry of mammography films at varying development temperatures and times
Radiological Physics and Advisory Division, Bhabha Atomic Research Centre, CT and CRS, Anushaktinagar, Mumbai, India. Journal of Medical Physics
02/2012; 37(1):40-5. DOI: 10.4103/0971-6203.92719
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.
Available from: Ruwan Jayasinghe
- "As can be inferred from the previous studies (Peer et al., 2001), film processing is one of the most important factors influencing the quality of the radiographic image using screen-film technology. The study done by Sharma et al. (2012) on light sensitometry of mammography films at varying development temperatures and times that they found when rise in development time from 1 to 6 min had an appreciable impact on the optical density. It increased from 3.54±0.03 "
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ABSTRACT: The aim of this study was to find out the effect of the different development time on X-ray film density in removing any discrepancy incurring due to processor related variables. One hundred double emulsion films were irradiated and were produced using 100 sensitometric strips with 21 steps each. The films were processed with different processing time with a gap of 10 s. Optical density was measured at 5 places and the mean net density value was calculated. Base plus fog densities of each film and densities of the 3 un-irradiated areas were also measured. Significant changes were observed in the base plus fog values and the optical density values of the X-ray films at varying development times. The lowest base plus fog of 0.17 was measured at 10 s developing time and the highest base plus fog of 0.36 was measured at 150 and 160 s. The observed changes of average net density values were in the range of 1.95 to-0.00267. The highest net density value was observed on the 21 st step of sensitometric strips with a developing time of 50 s. The results of the present study indicate that there is a positive relationship between the base plus fog densities and the developing time when other factors are controlled. At 70 s, the base plus fog density value exceeded the limit of 0.25 which is clinically unacceptable. Net density value of the present study was within the accepted limit for the selected development time periods.
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