Method for generating a contrast medium-assisted x-ray image and x-ray system

A method for making X-ray recordings in the combination of an X-ray system with contrast media, wherein the contrast medium contains at least one of the elements rhenium, hafnium, tantalum or tungsten, the method comprising:

• spectrally modifying radiation emitted by an X-ray tube of the X-ray system by introducing at least one additional filter, in which at least one of the elements with the atomic numbers 77 (iridium), 78 (platinum), 79 (gold), 80 (mercury), 82 (lead) or 83 (bismuth) is present, into the beam path in front of the X-ray tube;
• and wherein computer-assisted tomographic images are reconstructed;
• and
• using the increase in the image contrast, alongside the rise in image quality, to reduce the radiation dose or contrast medium dose.

An X-ray system for generating at least one X-ray image of a patient with incorporated contrast medium, comprising:

• at least one anode for generating X-ray radiation with an energy spectrum of bremsstrahlung and characteristic radiation;
• at least one X-ray detector for pixel-wise measurement of the X-ray radiation penetrating the patient;
• at least one filter, arranged in the beam path between the at least one anode and the at least one X-ray detector in front of the patient, configured to modify the energy spectrum used, wherein the patient absorbs a dose in order to generate detector data for the X-ray image and the X-ray image has a CNR value which represents the ratio of the maximum contrast in the image to the noise;
• at least one computer processor, including at least one memory store in which computer programs with calculation and control instructions for execution are stored, configured to control the X-ray system during operation and generate X-ray images from the received detector data, wherein
• at least one computer program is stored to carry out, when executed:
• modifying the energy spectrum by using at least one first filter, arranged in a beam path in front of the patient;
• generating detector data for the X-ray image upon the patient absorbing a dose of X-ray radiation, the X-ray image including a CNR value which represents a ratio of a maximum contrast in the image to noise;
• and
• adjusting the energy spectrum and the contrast medium to one another by using an additional filter, taking account of a thickness of the patient to be X-rayed such that an optimization criterion taken from an experimentally generated or simulated X-ray image, is maximized.