This invention relates to radiolabeled peptides and methods for producing such peptides. Specifically, the invention relates to peptides, methods and kits for making such peptides, and methods for using such peptides to image sites in a mammalian body labeled with technetium-99m (Tc-99m) via (Tc-99m) binding moieties. In particular, the peptide reagents of the invention are covalently linked to a polyvalent linker moiety, so that the polyvalent linker moiety is covalently linked to a multiplicity of the specific-binding peptides, and the Tc-99m binding moieties are covalently linked to a plurality of the specific-binding peptides, the polyvalent linker moiety, or to both the specific-binding peptides and the polyvalent linker moiety.