1. A system for use during a medical or surgical procedure on a body, said system generating a display representing the position and geometry of one or more body elements during the procedure based on one or more reference images, said system comprising: first means for producing the reference image of the one or more body elements; means for discriminating the one or more body elements in said reference image and creating an image data set representing a position and geometry of the reference image of the one or more body elements; second means for producing, during the procedure, a density image of the one or more body elements; a processor modifying the image data set according to the density image said processor generating a displaced image data set representing the position and geometry of the one or more body elements during the procedure; and a display utilizing the displaced image data set illustrating the position and geometry of the one or more body elements during the procedure.