Abstract: There is disclosed a diagnostic imaging agent which comprises a compound wherein at least one bifunctional ligand is chemically bonded to an amino group of amino oligosaccharide having the molecular weight of 500 to 2000 and having a reduction-treated reducing end of a sugar chain, or to an aldehyde group of a dialdehyde-oligosaccharide, at least one constituent monosaccharide of which is oxidation-cleaved, having the molecular weight of 500 to 2000 and having a reduction-treated reducing end of a sugar chain, and said ligand is coordinated with at least one metal ion selected from the group consisting of metal ions having the atomic number of 21-29, 31, 32, 37-39, 42-44, 49 and 56-83.

Abstract: A gadolinium complex of 1,4,7,10-tetraazacyclododecane-1,4,7,10-.alpha.,.alpha.',.alpha.",.alpha." '-tetrakis(methylacetic acid) or its salt, which is useful as a nuclear magnetic resonance imaging agent.

Abstract: There is disclosed an imaging agent for diagnosis comprising a compound composed of a polynuclear type compound of the formula I or II: ##STR1## wherein each X is a hydrogen atom or a bifunctional ligand, at least one of them are bifunctional ligand and m or n is an integer of 1 to 6, and at least one metal ion being coordinated with at least one bifunctional ligand moiety, said metal ion being selected from the group consisting of metal ions having the atomic number of 21-29, 31, 32, 37-39, 42-44, 49 and 56-83.

Abstract: There is disclosed an imaging agent for diagnosis comprising a compound composed of a polynuclear type compound of the formula I or II: ##STR1## wherein each X is a hydrogen atom or a bifunctional ligand, at least one of them are bifunctional ligand and m or n is an integer or 1 to 6, and at least one metal ion being coordinated with at least one bifunctional ligand moiety, said metal ion being selected from the group consisting of metal ions having the atomic number of 21-29, 31, 32, 37-39, 42-44, 49 and 56-83.

Abstract: A chelating compound of the formula:(R--NHOC--CH.sub.2).sub.n --A--(CH.sub.2 COOH).sub.m (I)wherein R is an aromatic ring-containing organic group, A is a residue of an aminopolyacetic acid excluding acetic acid groups (--CH.sub.2 COOH) therefrom, m is an integer of at least two and n is an integer of 1 or 2, or its salt, which has a specificity to a hepatobiliary system so that a complex formed between said chelating compound and a metallic element through a coordinate bond is useful as a diagnostic or therapeutic agent for hepatobiliary organs and tissues.

Abstract: There is disclosed a nuclear magnetic resonance imaging agent comprising a complex compound composed of (a) a dialdehyde-saccharide having a molecular weight of from 500 to 10,000, at least one of the constituent monosaccharides of which is oxidation-cleaved, (b) at least one complexing agent which is chemically coupled to an aldehyde group of the dialdehyde-saccharide and (c) a paramagnetic metal ion which is chemically coupled to the complexing agent.

Abstract: There is disclosed an imaging agent for diagnosis comprising a compound composed of a polynuclear type compound of the formula I or II: ##STR1## wherein each X is a hydrogen atom or a bifunctional ligand, at least one of them are bifunctional ligand and m or n is an integer of 1 to 6, and at least one metal ion being coordinated with at least one bifunctional ligand moiety, said metal ion being selected from the group consisting of metal ions having the atomic number of 21-29, 31, 32, 37-39, 42-44, 49 and 56-83.

Abstract: A chelating compound of the formula:(R-NHOC-CH.sub.2).sub.n --A--(CH.sub.2 COOH).sub.m (I)wherein R is an aromatic ring-containing organic group, A is a residue of an aminopolyacetic acid excluding acetic acid groups (--CH.sub.2 COOH) therefrom, m is an integer of at least two and n is an integer of 1 or 2, or its salt, which has a specificity to a hepatobiliary system so that a complex formed between said chelating compound and a metallic element through a covalent bond is useful as a diagnostic or therapeutic agent for hepatobiliary organs and tissues.

Abstract: A chelating compound of the formula:(R--NHOC--CH.sub.2).sub.n --A--(CH.sub.2 COOH).sub.m (I)wherein R is an aromatic ring-containing organic group, A is a residue of an aminopolyacetic acid excluding acetic acid groups (--CH.sub.2 COOH) therefrom, m is an integer of at least two and n is an integer of 1 or 2, or its salt, which has a specificity to a hepatobiliary system so that a complex formed between said chelating compound and a metallic element through a coordinate bond is useful and a diagnostic or therapeutic agent for hepatobiliary organs and tissues.

Abstract: A polyaminedithiol compound of the formula: ##STR1## wherein R.sub.1, R.sub.2, R.sub.11 and R.sub.12 are each a lower alkyl group, R.sub.21 is a hydrogen atom or a lower alkyl group, and R.sub.3 and R.sub.13 are each a hydrogen atom or a nitrogen-containing organic group, provided that at least one of R.sub.3 and R.sub.13 is a nitrogen-containing organic group, which is used for imaging of the regional cerebral blood flow.