Technetium-99m-tetrofosmin as a new radiopharmaceutical for myocardial perfusion imaging.

A new cationic complex, [ 99m Tc(tetrofosmin) 2 O 2 ] + , where tetrofosmin is the ether functionalized diphosphine ligand 1,2-bis[bis(2-ethoxyethyl)phosphino]ethane, has been synthesized and evaluated for potential use in myocardial perfusion imaging. The structure of the complex has been determined by x-ray crystallography of the 99 Tc analog. In comparison with previously reported 99m Tc complexes of alkyl-phosphines, the tetrofosmin species shows substantially increased clearance from nontarget tissue, especially blood and liver. A freeze-dried kit formulation has been developed