Generating attenuation image data and phase image data in an X-ray system

A non-transitory computer readable medium comprising computer instructions for generating phase image data, which, when being executed by a processor, configure the processor to perform act of:

• causing an x-ray detector operating in a first measurement mode to obtain first x-ray image data comprising first pixel-wise measurement signal values;
• simultaneously with the causing act, causing the x-ray detector to simultaneously operate in a second measurement mode to simultaneously obtain second x-ray image data comprising second pixel-wise measurement signal values, the second measurement mode being different from the first measurement mode, wherein the first x-ray image data is obtained with a first spectral weighting simultaneously with the second x-ray image data which is obtained with a second spectral weighting different from the first spectral weighting;
• and
• determining the phase image data comprising pixel-wise phase values from the first and the second x-ray image data by determining a phase value at a pixel from a first measurement signal value obtained in the first measurement mode at the pixel and a second measurement signal value obtained in the second measurement mode at the pixel;
• and
• generating an output that includes the determined phase image data.

An x-ray system comprising:

• an x-ray source;
• an x-ray detector;
• and
• a controller;
• wherein the x-ray detector is configured simultaneously to operate in a first measurement mode to obtain first x-ray image data comprising first pixel-wise measurement signal values, and to operate in a second measurement mode different am the first measurement mode to obtain second x-ray image data comprising second pixel-wise measurement signal values, and
• wherein the controller is configured to determine phase image data comprising pixel-wise phase values from the first and the second x-ray image data by determining a phase value at a pixel from a first measurement signal value obtained by the detector in the first measurement mode at the pixel and a second measurement signal value obtained simultaneously with the first measurement signal value by the detector in the second measurement mode at the pixel with different spectral weightings such that the first x-ray image data is obtained with a first spectral weighting simultaneously with the second x-ray image data which is obtained with a second spectral weighting different from the first spectral weighting,
• wherein the controller is further configured to generate the phase image data based on the first and the second x-ray image data simultaneously obtained by the detector operating simultaneously in the first and the second measurement modes.