To generate a tomosynthetic 3D x-ray image composed of a number of slice images, a tomosynthetic 3D intermediate image composed of a number of slice images is reconstructed from 2D projection images that have not been noise-filtered. The microcalcium regions contained in these slice images are segmented, and one or more subject slice images relevant to these microcalcium voxels are determined for each microcalcium region. The microcalcium voxels belonging to the segmented microcalcium region in this subject slice image or in these subject slice images are projected forwards in the 2D projection images, and the microcalcium pixels associated with these microcalcium voxels are marked in the 2D projection images. Noise-filtered 2D projection images are subsequently generated by subjecting the microcalcium pixels of the 2D projection images to no noise filtering or a noise filtering that leads to a noise reduction reduced relative to the remaining image regions. The tomosynthetic 3D x-ray image is then calculated from the 2D projection images that have been noise-filtered in this manner.