Image provision for registration

The invention relates to a device and a method for providing a basis for registering a three-dimensional model of an anatomical region with two-dimensional projection images, by deriving a three-dimensional model of an anatomical region at a phase of a periodic signal; deriving two-dimensional projection images of a region which overlaps with the anatomical region re-constructed as the three-dimensional model; pre-5 selecting a subset of projection images out of the derived two-dimensional projection images, which are closest to the phase; and selecting a reference image for the registration from the subset of pre-selected projection images by choosing the projection image with the most contrast.