A method for providing reference markers in magnetic resonance (MR) images which are highly discernible and accurately defined in the MR image. The method may be carried out with short imaging times. The reference markers have a volume containing NMR active nuclei and an electron spin resonance relaxant...http://www.google.de/patents/US5218964?utm_source=gb-gplus-sharePatent US5218964 - Method for providing accurate reference markers in magnetic resonance images
