Data of a predetermined volume portion of an object under examination is captured by an x-ray system that includes an x-ray source and a detector. The x-ray source is activated to generate x-rays that emerge from the x-ray source, radiate through the volume portion, and after radiating through, impinge on the detector. X-rays impinging on the detector are captured pixel by pixel, in order to capture the data of the predetermined volume portion. With the pixel-by-pixel capture, only a subset of all the pixels of the detector is evaluated.