Abstract: Radiographic apparatus includes indicium means for indelibly imprinting computerized axial tomographs with identification data which relates to the position of the tomographic slice in relation to a fixed datum position such as the top of a patient's head. The indicium comprises a member having characteristically varying radiopacity which is positioned in the vicinity of the radiographic slice so as to be scanned by the exploring radiation and is fixedly secured in relation to the datum position.

Abstract: A method for retrieving exposure information from film images includes selecting an exposed and developed photographic emulsion, regionally bombarding the emulsion with X-rays, regionally measuring and recording the resultant X-ray fluorescence therefrom. The method may also include the further step of translating the resultant fluorescence into a visual image. This method is carried out on suitable apparatus including a film holding device, X-ray generating device for generating an X-ray beam of a selected energy level and directing it regionally on the film, a measuring device for regionally measuring the X-rays fluorescence of the film and an image recording and/or translating device for translating the resultant fluorescence into a physical image.