1. In a method for generating for X-ray layer images of an examination zone of the type comprising the steps of generating a plurality of different projection images of the examination zone, each of said projection images being generated from a different perspective and being represented as image values for a plurality of image points, and combining the values for corresponding image points in the projection images to generate a value for each point in a layer image; the improvement wherein the step of combining the values comprises choosing the next to the lowest value from the values of the corresponding image points in the projection images to be the value of the corresponding image point in the layer image.