A method for fusing a plurality of images. The method includes: acquiring the plurality of images from a plurality of different modalities, each one of the images having a different reference space; and fusing the plurality of images into a common reference space, such common reference space being different from the reference space of each one of the plurality of acquired images. Thus, with such method, a unified process is provided for handling fusion across multiple clinical interventional and/or surgery (i.e., intra-operative) procedures.