An arrangement for positioning an X-ray machine, with an input and an output device, for interactive control, with a memory region, in which digitised X-ray images and X-ray machine data are stored, an interface, by means of which information is exchanged with the X-ray machine, a pointing device for selecting regions in digitized X-ray images, a processing unit, which carries out calculations based on the digitized X-ray images, the associated X-ray machine data and the selected region, in order to determine control data such that the X-ray machine is controlled whereby, on taking an image, the selected region is screened.