Preparation of [99mTc(DMPE)2Cl2]+ for myocardial imaging by using Fe-(DMPE) complexes

The preparation of [99mTc(1,2-bis(dimethylphosphino)ethane)2Cl2]+ ([99mTc(DMPE)2Cl2]+) for imaging the myocardium is investigated. Starting from Fe(III)- or Fe(II)-DMPE and 99mTcO4- different preparation variants are compared. In these reactions either ascorbic acid or DTPA serves as an agent for complexing iron. A simple procedure using lyophilized initial components is represented. Its application yields [99mTc(DMPE)2Cl2]+ with a radiochemical purity of more than 95%. Organ distribution studies performed in rats emphasize the high myocardial accumulation of this preparation.