Surgical navigation systems including reference and localization frames

The invention is a system for use during a medical or surgical procedure on a body. The system generates a display from an image data set (106) representing the position of one or more body elements (10, 20, 30; 141; 806; 940) during the procedure based on scans (40) taken of the body. At least some of the body elements are movable with respect to each other. Each scan (40) has a reference for each of the one or more body elements (10, 20, 30; 141; 806; 940) and the reference of a particular body element (10, 20, 30; 141; 806; 940) has a known spatial relation to the particular body element (10, 20, 30; 141; 806; 940). The system comprises a plurality of reference frames (116; 122; 200; 302; 400; 900; 956), at least one attached to each of the movable body elements. It also comprises a localizer (108; 136; 1100) for identifying, during the procedure, the position of the reference for each of the body elements (10, 20, 30; 141; 806; 940) to be displayed, as well as a processor (104; 1108) for modifying the image data set (106) according to the identified position of the reference during the procedure, as identified by the localizer (108; 136; 1100), said processor (104; 1108) being adapted to generate an image data set (122) representing the position and geometry of the body elements (10, 20, 30; 141; 806; 940) according to the identified position of the reference frames during the procedure, as identified by the localizer. Also included in the system is a display (124; 1106) utilizing the displaced image data set (122) generated by the processor (104; 1108), illustrating the position and geometry of the body elements (10, 20, 30; 141; 806; 940) during the procedure.