Purpose: X-ray inversesquare law sensitometry is considered the gold standard for the sensitometric evaluation of film characteristics. Since the spectral output of light sensitometers and intensifying screens differ, light sensitometers are used only for relative measures of film characteristics during daily processor quality control and are not used to compare two different films. In this study we investigated if characteristic curves of specific films differ when using light sensitometry and the light from an intensifying screen.
Materials and Methods: Commercially available sensitometers were used to give the characteristic H&D curves of the tested films. The screen sensitometry was performed using the Gray and Haus method of placing a stepped neutral density optical attenuator between the intensifying screen and film of a conventional mammographic cassette. The screen sensitometry method has been shown to have an excellent correlation to the inversesquare law sensitometry.
Results and Conclusions: A comparison of films exposed to light sensitometers and to intensifying screen sensitometry will be discussed.