1. A system for generating an image dataset, comprising: a first system for acquiring a first image dataset of a subject; a second system, different from said first system, for acquiring a second image dataset of said subject; a navigation system for determining first position information comprising respective positions of said first system during acquisition of said first image dataset and second system during acquisition of said second image dataset; an image position determining system which generates second position information comprising a position of said first image dataset and a position of said second image dataset; and a combining unit for combining said first image dataset and said second image dataset in a combining operation selected from the group consisting of superimposition and fusion, dependent on said first position information and said second position information.