There is described an X-ray diagnostic device for performing cephalometric, dental or orthopedic examinations on a patient who is seated or standing. The X-ray diagnostic device comprises an X-ray emitter and an image detector embodied as a flat-panel detector that are arranged situated opposite each other on an orbitally moveable mount. The X-ray diagnostic device further comprises means for adjusting the height of the X-ray emitter and the image detector, a digital image system for recording a projection image using rotation angiography, a device for image processing for reconstructing the projection image into a 3D volume image; and a device for correcting physical effects or artifacts for representing soft tissue in the projection image and in the 3D volume image reconstructed therefrom.