A system and methods are provided for evaluating the position of surgical implants or openings formed in anatomical tissue during medical procedures, in which an initial 3-dimensional image of the anatomical tissue is combinable with one or more subsequent 3-dimensional images of the same or correlating tissue, and without the use of ionizing radiation on a patient for at least the subsequent images. The system (100) includes a software program (122), a computer (102) with display (104), a radiographic image scanning device (112), and a non-radiographic image scanning device (114). The computer accesses a medical patient image database (128) and a medical implant database (124) for images used by the software program. A pre-operative image (20) is combined with subsequent images to facilitate evaluation of the proposed placement of a surgical implant or opening relative to tissues of the patient anatomy. Methods of evaluating the accuracy of surgical guides and of fabricating surgical guides are also disclosed.