The present invention pertains to a fiducial implant for the human body that is detectable by an imaging system. The invention is comprised of a first portion and a second portion. The first portion is configured to be detected by an imaging system when placed beneath the skin. The second portion is...http://www.google.de/patents/US4945914?utm_source=gb-gplus-sharePatent US4945914 - Method and apparatus for providing related images over time of a portion of the anatomy using at least four fiducial implants
