Abstract: Apparatus for recording data on X-ray films which are stored in cassettes having windows for exposure of certain portions of films therein includes a housing with two slots for insertion of cards with information pertaining to the patient and/or physician. The housing confines a battery of liquid crystals and an associated digital clock, digital calendar and digital counter each adapted to be actuated from the exterior of the housing to cause the corresponding liquid crystals to furnish the selected information. Such information, together with information on one of the cards, is imaged onto the exposed portion of X-ray film in the properly inserted cassette by a partly light transmitting mirror and an optical element.

Abstract: A dosimeter for use in mammographs wherein a plate-like body of electrically non-conductive hard foamed material generates charge carriers in response to exposure to radiation. The body is provided with electrodes which are connected with an energy source. The output signal of the dosimeter is used to regulate the amounts of radiation to which an object is exposed. The entire dosimeter can be installed between the source of radiation and X-ray film or another carrier of images of objects because the dosimeter does not cast a shadow on the film when the object is exposed to radiation.

Abstract: Latent images which are formed on dielectric receptor sheets during exposure to object-modulated primary and stray X-rays, while the sheets dwell in the interelectrode gap of an ionography imaging chamber, are developed in an electrophoretic unit which neutralizes the effect of stray radiation upon the receptor sheets so that the developed visible images are reproductions of those portions of latent images which are formed as a result of exposure to primary radiation. The neutralizing involves ascertaining the intensity of stray radiation behind the imaging chamber by resorting to one or more dosimeters and one or more rasters or analogous devices which absorb stray radiation, and applying to the electrodes of the developing unit a reverse potential which is proportional to the intensity of stray radiation. Alternatively, the intensity of stray radiation can be ascertained empirically and the reverse potential is selected by hand, depending on the density and thickness of the object.

Abstract: An ionography imaging chamber wherein the sections of the pressure vessel carry concentric spherical electrodes centered at the source of X-rays and defining a spherical interelectrode gap. A dielectric receptor sheet is converted into a portion of a hollow cylinder during introduction into the gap and its marginal portions are thereupon biased against one of the sections by an inflatable gasket which seals the gap from the surrounding atmosphere prior to admission of compressed high Z gas. The admitted gas deforms the sheet against the electrode which is nearer to the source of X-rays while the gas at the rear side of the sheet is allowed to escape by way of ports in the respective section. If the gap receives two sheets at a time, the admission of high Z gas takes place between the sheets so that each sheet overlies and closely follows the outline of the corresponding electrode.

Abstract: An ionography imaging chamber wherein the front side face of the pressure vessel is immediately adjacent to the foremost portion of the interelectrode gap and the image-receiving part of a dielectric receptor sheet in the gap extends into immediate proximity of the front side face. The front part of the margin of the sheet is bent over the front edge portion of one of the electrodes, and the gasket which seals the interelectrode gap while the latter is filled with compressed high Z gas abuts against the folded-over front part of the sheet. The sheet is attached to a drawer which carries one of the electrodes and is insertable into a compartment of the main section of the pressure vessel. One or more auxiliary electrodes are installed in the foremost portion of the gap to prevent distortion of latent images in the region which is nearest to the front side face of the pressure vessel.

Abstract: A tomographic image of a selected layer of a stationary object is made by moving the source of X-rays along a first path at one side of the selected layer and by moving an ionography imaging chamber which contains a dielectric receptor sheet along a second path at the other side of the selected layer. The movement of the sheet is synchronized with movement of the source of X-rays and includes a translatory movement in a direction counter to the direction of movement of the source, a pivotal movement to maintain the sheet in a plane which is normal to the central beam of the bundle of X-rays, and a sidewise movement to vary the distance between the selected layer and the sheet so that the length of the projection of selected layer upon the sheet remains unchanged. If the sheet is rectangular, the pivotal movement is performed about an axis which is located in the plane of the selected layer and is parallel to the shorter sides of the sheet.