Impact of the Processing Methods on the Performance of the X-ray Film Screen Combinations

In ISO9236-1 there is no description of the processing method for the sensitometric determination of an x-ray film by the film-screen combination method. But it states that when the film-screen combination system is being determined, either manual processing or automatic processing can be adopted. The different processing procedures will result in wide different sensitivities and average gradients. This paper describes the sensitometric determination of the film-screen combination systems of four types of medical x-ray films by the bootstrap method with manual processing and automatic processing. Their sensitometric results show that there are certain difference in the performance of the film-screen combination systems between the manual processing and the automatic processing. With the manual processing, the resultant sensitivity is faster and average gradient steeper, and min. density and max. density almost same with the automatic processing. These results are identical with the results obtained in the sensitometric determination by visible light exposure.