1. A method to process images for interventional imaging, wherein a 3D image of an object of interest is visualized with a medical imaging system, the medical imaging system comprising an X-ray source and a detector, the method comprising: acquiring a plurality of 2D-projected images of the object along a plurality of orientations of the imaging chain to have a plurality of 2D-projected images of a rectilinear instrument, wherein the rectilinear instrument has been inserted into the object; determining a 3D reconstruction of the instrument by determining the complete 3D position from the 3D position of the tip of the instrument and by the orientation of the instrument, the 3D reconstruction such that a plurality of 2D projections of the 3D image of the instrument, along the respective orientations in the 2D-projected image of the object were acquired, are closest to the acquired 2D-projected images of the object; and superimposing the 3D reconstruction of the instrument over the 3D image of the object so as to obtain a 3D image comprising the object and the instrument.