Abstract: In a method for the creation of a dental 3D radiograph of at least a subregion, forming a volume, of an object using an X-ray apparatus, the volume is recorded as a 3D radiograph from a plurality of projected images during a revolution around the object. At least a part of the object is displayed in a graphical representation before the radiograph of the volume is created, the position of the graphical representation relative to the current position of the apparatus and the patient being known. The volume to be radiographed, governed by the positioning of the object relatively to the apparatus and by the choice of the settings data and/or control data, is placed in the graphical representation in an at least approximately correct position, and when there is a change in position and/or size of the volume to be radiographed within the graphical representation, the settings data and/or control data for the creation of the 3D radiograph are defined.

Abstract: In a method for the creation of a dental 3D radiograph of at least a subregion, forming a volume (42, V1, V2), of an object (14) using an X-ray apparatus (1), said volume can be recorded as a 3D radiograph from a plurality of projected images during a revolution around said object. At least a part of the object (14) is displayed in a graphical representation (40, 71, 72, 73) before the radiograph of the volume (42, V1, V2) is created, the position of the graphical representation (40, 71, 72, 73, 74) relative to the current position of the apparatus and the patient being known.

Abstract: In a method and x-ray apparatus for making and reproducing a radiological tomogram of a subject, the subject is irradiated with radiation emanating from a focus disposed at a known distance from a focal plane, situated at the subject. The focal plane is disposed at a known distance from a radiation receiver, which is disposed in the image plane, and which contains a number of picture elements. In a digital radiological tomogram, either the slice position with the aforementioned distances is allocated to respective picture elements, or a correction factor, based on the slice position and the aforementioned distances, is allocated to the respective picture elements, from which a corrected image is obtained with the subject appearing with a corrected size corresponding to the size of the subject in the focal plane.

Abstract: A method is proposed for compensating for the dark current of an electronic sensor having a plurality of pixels with an individual dark-current response, radiation for producing an image signal (BS) being directed from a beam source (3) onto a detector arrangement (4) containing the sensor, and a recording being taken with different clock-out rate (v) (integration time) by reading the detector signal (S) present in the pixels of the sensor, in which, before the beginning or after the end of the recording with radiation, the sensor is read out without radiation with at least two different clock-out rates (v1, v2) and at least two dark-current signals (DC1, DC2) are thereby picked up for each pixel, in which the dark-current signals (DC1, DC2) that have been read out are then used to calculate a dark-current value (DV) of individual pixels of the sensor as a function of the clock-out rate (v), and in which a correction is then made, using the dark-current value associated with each pixel, to the detector signal