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 includes a software program, a computer with display, a radiographic image scanning device, and a non-radiographic image scanning device. The computer accesses a medical patient information database and a medical implant database for images used by the software program. A pre-operative image 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.