1. An analysis method for data of an examination object, selecting a sub-volume of a volume data record, the data comprising at least one volume data record of the examination object and a plurality of two-dimensional projection images of the examination object, the volume data record includes a plurality of voxels and each voxel is assigned to a location in the three-dimensional space; registering a plurality of projection images in relation to the volume data record, each projection image includes a multiplicity of pixels, each pixel is assigned to a location in a two-dimensional projection plane and has a pixel data value, and a projection volume is assigned to each pixel, each of the projection volumes are specified in that they are mapped by the radioscopy onto the pixels to which they are assigned; and specifying a functional parameter of the examination object for the pixels of the projection images depending on the pixel data values, wherein for each pixel, when specifying the functional parameter, consideration is given to the locations and the number of those which lie both within a sub-volume and within the projection volume that is assigned to the pixel concerned, and wherein the sub-volume is specified on the basis of the selected segmented vessels.