Physically and chemically stabilized polyatomic clusters for magnetic resonance image and spectral enhancement

A composition of matter for enhancing induced internal magnetic resonance images or shifting spectra arising from induced internal magnetic resonance signals, comprising:

• a polyatomic complex comprising plural atoms having magnetic moments which are mutually magnetically coupled within the polyatomic complex, said complex including bridging molecular or atomic species which are individually bound to at least one of said plural atoms having magnetic moments and other atoms of the polyatomic complex, said polyatomic complex consisting essentially of four Cr(III) atoms which are bound to a central tetrahedral sulfur atom and are octahedrally coordinated by bridging ligands, said bridging molecular species being free of intermolecular bonds;
• and
• a biocompatible, physiologically clearable carrier associated with the polyatomic complex, said carrier comprising Fraction A of beef-lung heparin having a molecular weight between about 6,000 Daltons and 10,000 Daltons, and having binding complementarity to determinants of mammalian endothelia and epithelia;
• said carrier being in association with said polyatomic complex;
• wherein the proportion of said polyatomic complex to said carrier is at least about 1:20 by weight;
• said carrier being of low toxicity to mammals and containing less than about 5 weight percent cross-linked or microaggregated species.

A composition of matter for enhancing induced internal magnetic resonance images or shifting spectra arising from induced internal magnetic resonance signals, comprising:

• a polyatomic complex comprising plural atoms having magnetic moments which are mutually magnetically coupled within the polyatomic complex, said complex including bridging molecular or atomic species which are individually bound to at least one of said plural atoms having magnetic moments and other atoms of the polyatomic complex, said polyatomic complex consisting essentially of four Cr(III) atoms which are bound to a central tetrahedral sulfur atom and are octahedrally coordinated by bridging ligands, said bridging molecular species being free of intermolecular bonds;
• and
• a biocompatible, physiologically clearable carrier associated with the polyatomic complex, said carrier comprising Fraction A heparin or a fragment thereof having a molecular weight between about 1,000 Daltons and about 10,000 Daltons, and having binding complementarity to determinants of mammlian endothelia and epithelia;
• said carrier substance being in association with said polyatomic complex;
• wherein the proportion of said polyatomic complex to said carrier is at least about 1:20 by weight and said carrier contains less than about 5 weight percent cross-linked or microaggregated species and being of low toxicity to mammals.

A method for enhancing induced internal magnetic resonance images or shifting spectra arising from induced internal magnetic resonance signals, comprising the steps of:

• identifying a living vertebrate animal to be imaged;
• introducing into the blood stream or body cavity of said animal a diagnostic imaging or enhancing agent or spectral shift agent comprising a substantially completely water-soluble polymeric carrier molecule of native or modified Fraction A heparin or fragment thereof having a molecular weight range between about 1,000 Daltons and 10,000 Daltons, and having binding complementarity to determinants of mammalian endothelia and epithelia, said agent also comprising a polyatomic complex associated with said carrier molecule, said polyatomic complex including plural atoms of magnetic moment which are mutually magnetically coupled within the polyatomic complex said polyatomic complex essentially of four Cr(III) atoms which are bound to a central tetrahedral sulfur atom and are octahedrally coordinated by bridging ligands,
• applying to said animal a strong magnetic field which includes a magnetic gradient;
• applying to at least a portion of said animal an electromagnetic perturbation field at a radio frequency generally corresponding to a resonant frequency of a predetermined atomic nucleus at a magnetic field strength which falls within the range of field strengths applied to said animal by said strong magnetic field;
• and
• measuring radio frequency emissions given off by magnetically aligned perturbed atomic nuclei, to determine a spatial map or spectral shift of magnetic resonance characteristics within tissues of said animal.