1. A method, comprising: acquiring a plurality of two-dimensional (2D) angiographic images with two or more orientations of an angiographic imaging system, each orientation having an unknown imaging geometry, wherein each of the plurality of 2D angiographic images includes a projection of a plurality of non-invasive fiducial markers having a known three-dimensional (3D) configuration; and registering selected 2D angiographic images to a 3D scan volume.