Rare earth/chelating agent complex for digital fluoroscopy

A rare earth/chelating agent complex is employed in digital fluoroscopy. More specifically, a contrast medium is utilized in digital fluoroscopy, the contrast medium consisting of a non-radioactive composition of a rare earth metal and a chelating agent. The rare earth metal is lutecium or ytterbium, while the chelating agent is DTPA, EHPG or HBED. The digital fluoroscopy method results in the development of diagnostic energy difference image information as a result of application of X-ray beams of two different energy levels, coupled with subtraction processing of the resulting image information.