Method for generating a gain-corrected x-ray image

A method of generating a gaincorrected x-ray image using a flat-panel x-ray detector having a plurality of detector elements, the method comprising:

• a calibration step comprising determining a pluality of gain images for a plurality of different imaging variables settings, the different imaging variables settings related to at least one imaging variable, each gain image having a plurality of gain values corresponding to the plurality of detector elements;
• an x-ray recording step comprising determining a current imaging variables setting of the imaging variable and assigning a data value to each of at least part of the detector elements based on the current imaging variables setting;, and
• a correcting step comprising a gain correction of the assigned data values using at least two of the gain images, the gain correction including correcting each data value based upon an interpolation between corresponding pixels of the at least two of the gain images, the interpolation executed with regard to the current imaging variables setting of the imaging variable, wherein
• the imaging variable includes a rotation angle of the flat-panel x-ray detector relative to an x-ray tube, the rotation angle representing a rotation of a flat plane in which the flat-panel x-ray detector is arranged relative to a plane in which the x-ray tube is arranged, and
• the plurality of gain images include gain images for imaging variables settings of the rotation angle being 0° and 90°.

An x-ray imaging system, comprising:

• a flat-panel x-ray detector having a plurality of detector elements for recording a plurality of data values, and
• an image processing unit configured to:
• generate and store a plurality of gain images;
• and
• generate at least part of the data values based on gain values included in the gain images,
• wherein each gain value is derived from an interpolation between corresponding pixels of at least two of the gain images.