Abstract: The present invention relates to cardiac tropism radiopharmaceutical products incorporating a nitride complex os a transition metal and having a rapid myocardial clearance.These complexes are based on the formula:(M.tbd.N)L.sup.1 L.sup.2 (I)in which M is a transition metal such as .sup.99m Tc and L.sup.1 and L.sup.2 comply with the formula: ##STR1## in which at least one of the R and R' represents a branched alkyl group having one or more ether functions, a tetrahydrofurfuryl or ether group, a tetrahydrofurfuryl or dioxaspiro or dialkoxy piperidino groups.

Abstract: The invention concerns a radiopharmaceutical product having in particular a cerebral tropism comprising a nitruro complex of a transition metal and the method for preparing said product. This complex satisfies the formula (M.tbd.N)L.sup.1 L.sup.2 (I) in which M is a transition metal, such as Tc99m, Re 186 or Re188, and L.sup.1 and L.sup.2, which may be identical or different, satisfy the formula ##STR1## in which R.sup.1 and R.sup.2 may be alkyl radicals, V and W may be O, S or Se, n=0 or 1, l=0 or 1, m=0 or 1, and X represents N--C, C, or As.