Effect of reduced scatter on radiographic information content and patient exposure: a quantitative demonstration

If a normal screen-film exposure is made using a conventional grid, a reduced exposure may be used with a superior scatter removal device to record the same image information. This theoretical conclusion is not readily demonstrated because of the limited visibility on the underexposed film. In this study radiographs underexposed by a factor of three with a scanning multiple slit assembly (SMSA) were enhanced autoradiographically and found visually to contain more information than properly exposed radiographs obtained under similar conditions using a conventional Bucky grid. This observation was confirmed by contrast scale and noise measurements. Furthermore, the entrance skin exposure of the radiograph using the SMSA was 45% of that required with the grid technique at the same beam quality.