FIELD: medicine, pharmaceutics.SUBSTANCE: invention refers to a pharmaceutical agent to be used as a diagnostic agent containing an inorganic matrix in the form of particles of amorphous or mixed amorphous and crystalline structures which contains a portion of positron emission nuclides in addition to natural isotope distribution of structural type-forming elements anions and cations. The inorganic matrix is represented by topaz (Al2F2)[SiO4], chiolite Na[Al3F4], wavellite Al3(PO4)2(OH, F)2, calcium carbonate CaCO3, maghemite -Fe2O3, zeolites of general formula Mn[(AlO2)x(SiO2)y] (M = metal), magnetic iron Fe3O4, barium sulphate BaSO4, gallium phosphate GaPO4, apatite or fluorohydroxyapatite Ca5(PO4)3(OH, F)=3Ca3(PO4)2*Ca(OH, F)2 and fluorite CaF2. The positron emission nuclides are specified in [15]O, [30]P, [13]N, [65]Ga, [11]C, [131]Ba, [26]A1, [68]Ga and [18]F, and their number in the inorganic matrix makes more than 1. The invention also refers to a method for preparing said pharmaceutical agent involving mixing two solutions of soluble salts and depositing them wherein one salt is saturated by positron emission nuclides, while the cations of one salt are deposited with the cations of the other salt to form the inorganic matrix. The invention also refers to a pharmaceutical composition used for the purpose of diagnostic visualisation wherein more then 0.001% of particles contained in the composition represent said inorganic matrix.EFFECT: invention provides simplified production of specific particles of the more prolonged applicability for the use which are applicable for diagnostic visualisation.9 cl, 6 dwg, 2 tbl, 3 exИзобретение относится к фармацевтическому средству для использования в качестве диагностического агента, которое содержит неорганический матрикс в виде частиц из аморфных или смеси аморфных и кристаллических структур, который в дополнение к природному распределению изотопов структурных тип-образующих элементов анионов и катионов содержит долю по
