Abstract: There are provided polychelants and their metal chelates which are useful in diagnostic imaging and in radiotherapy and which comprise a plurality of macrocyclic chelant moieties, e.g. DOTA residues, conjugated to a polyamine backbone molecule, e.g. polylysine. To produce a site-specific polychelate, one or more of the macrocyclic chelant carrying backbone molecules may be conjugated to a site-directed macromolecule, e.g. a protein. For example, adducts of a macrocyclic chelant can be formed by the process of (a) dispersing a carboxylic macrocyclic chelant in a polar, anhydrous solvent, (b) adding a base with a pKa sufficient to remove all carboxyl protons to create an amine salt of the chelant soluble in the solvent, (c) chilling the reaction mixture to between about 5.degree. C. and 55.degree. C.

Abstract: An imaging contrast medium comprising a physiologically tolerable multinuclear complex (as defined in claim 1) is disclosed. The multinuclear complex contains at least two, but preferably three or more contrast enhancing atoms. For X-ray or ultrasound imaging techniques heavy metal atoms are used to enhance contrast, whereas in Magnetic Resonance Imaging paramagnetic metal atoms are contrast enhancing. Molybdenum and tungsten are preferred contrast enhancing atoms. The medium may also be used therapeutically.

Abstract: There are disclosed polychelant compounds, that is multi-site metal chelating agents, and chelates formed therewith. The polychelants and especially their paramagnetic metal, heavy metal or radioactive metal polychelates are particularly suitable for use in diagnostic imaging, heavy metal detoxification or radiotherapy. The polychelants have a linear or branched oligomeric structure comprising alternating chelant and linker moieties bound together by amide or ester moieties the carbonyl groups whereof being adjacent the chelant moieties, each polychelant comprising at least two said chelant moieties capable of complexing a metal ion.

Abstract: Radiopharmaceuticals consisting essentially of a lipophilic, charge neutral radionuclide complex of a diaminedithiol ligand having 1-4 ester groups of the formula --A--COOR where A is a straight or branched chain alkylene of 0-10 carbon atoms and R is an alkyl group of 1-10 carbon atoms are useful in radioimaging brain perfusion in primates. Ester-substituted diaminedithiols in sterile, pharmaceutically acceptable form, and kits of the diaminedithiols and sterile, non-pyrogenic reducing agents for reducing preselected radionuclides are also provided. Technetium-99m is a preferred radionuclide.

Abstract: There are provided polychelants and their metal chelates which are useful in diagnostic imaging and in radiotherapy and which comprise a plurality of macrocyclic chelant moieties, e.g, DOTA residues, conjugated to a polyamine backbone molecule, e.g, polylysine. To produce a site-specific polychelate, one or more of the macrocyclic chelant carrying backbone molecules may be conjugated to a site-directed macromolecule, e.g. a protein.

Abstract: There are disclosed polychelant compounds, that is multi-site metal chelating agents, and chelates formed therewith. The polychelants and especially their paramagnetic metal, heavy metal or radioactive metal polychelates are particularly suitable for use in diagnostic imaging, heavy metal detoxification or radiotherapy. The polychelants have a linear or branched oligomeric structure comprising alternating chelant and linker moieties bound together by amide or ester moieties the carbonyl groups whereof being adjacent the chelant moieties, each polychelant comprising at least two said chelant moieties capable of complexing a metal ion.

Abstract: Radiopharmaceuticals consisting essentially of a lipophilic, charge neutral radionuclide complex of a diaminedithiol ligand having 1-4 ester groups of the formula --A--COOR where A is a straight or branched chain alkylene of 0-10 carbon atoms and R is an alkyl group of 1-10 carbon atoms are useful in radioimaging brain perfusion in primates. Ester-substituted diaminedithiols in sterile, pharmaceutically acceptable form, and kits of the diaminedithiols and sterile, non-pyrogenic reducing agents for reducing preselected radionuclides are also provided. Technetium-99m is a preferred radionuclide.