Abstract: The invention relates to the preparation of complexes of 99m-technetium, 186-rhenium or 188-rhenium usable as radiopharmaceutical products.For this preparation, an oxidized compound of .sup.99m Tc, .sup.186 Re or .sup.188 Re, e.g. an alkali metal or ammonium perrhenate or pertechnetate, is reacted with a first ligand chosen from the group of substituted or unsubstituted, aliphatic and aromatic phosphenes and polyphosphenes and a second nitrogenous ligand constituted by an ammonium nitride or a pharmaceutically acceptable metal or by a nitrogenous compound having a >N--N< unit, such as hydrazine, a hydrazine derivative, dithiocarbazic acid and dithiocarbazic acid derivatives.The product obtained can be used as it is as a radiopharmaceutical product or can serve as an intermediate for the preparation of other radiopharmaceutical products by exchange reaction with a third ligand, a monoclonal antibody or an antibody fragment.

Abstract: The invention relates to a radiopharmaceutical product more particularly having a cardiac tropism, incorporating a nitride complex of a transition metal and the process for the preparation thereof.This complex complies with the formula:(M.ident.N)L.sup.1 L.sup.2 (I)in which M is a transition metal, e.g. Tc99m, Re 186 or Re 188 and L1 and L2, which can be the same or different, comply with the formula: ##STR1## in which R.sup.1 and R.sup.2 can be alkyl radicals, V and W can be O, S or Se, n=0 or 1, m=0 or 1, and Y represents N, P or As.

Abstract: The invention relates to specific relaxation agents for organs or pathologies, which can be used for modifying the contrasts in medical imaging by nuclear magnetic resonance.These agents are constituted by a complex of a paramagnetic element having a biologically active ligand or a ligand coupled to a biologically active molecule and which is specific to an organ or pathology. Thus, they are selectively fixed to the organs and make it possible to modify the contrasts in imaging by nuclear magnetic resonance, due to the presence of the paramagnetic element, which modifies the relaxation times.For example, when examining the kidney, the complex can be constituted by dimercaptosuccinate or gadolinium diethylene triaminopentaacetate, whilst gadolinium phytate is used in examinations of the liver.

Abstract: A process for the preparation of a fatty acid tagged with radioactive iodine, wherein a brominated or iodized fatty acid is reacted, preferably in the omega position, with radioactive iodide in the dry state or with an aqueous solution of radioactive iodide, in the presence of vehicling iodide, to exchange the bromine or iodine of such fatty acid for radioactive iodine.Application to use as radio-pharmaceutical products for studying cardiac metabolism troubles in human beings by scintigraphy.

Abstract: A method of using .sup.99m technetium for tagging excipients in medical diagnosis by scintigraphy comprises mixing, in an aqueous solution of alkali-metal pertechnetate, an excipient and a reducing agent in the form of a complex, which complex is such that the association constant of the anion with reduced technetium is less than the association constant of the excipient with reduced technetium, thereby forming a radio-pharmaceutical substance which is a complex between the excipient and .sup.99m technetium.

Abstract: A method for preparing a pyrophosphate-tin composition labelled with 99.sup.m technetium for medical diagnosis by scintigraphy, especially bone scintigraphy. A pyrophosphate solution and a freshly prepared stannous chloride solution are mixed together and then neutralized to a pH within the range of 5 to 7, the mixture is eventually lyophilized in order to obtain a pyrophosphate-tin complex in powder form which is then mixed with a solution containing 99.sup.m Tc, the last-mentioned final step of the method being carried out at the moment of use. The complex has a pyrophosphate-tin molecular ratio of at least 30.