Contrasting and safe
Chemists from the Novosibirsk Institute of Organic Chemistry SB RAS and the International Tomography Centre SB RAS have developed new, original groups of nitroxyls and metal complexes that have proved unusually well soluble and very resistant in aqueous solutions.
These interesting properties have impelled the scientists to attempt to use them in magnetic resonance tomography, as contrasting means. Experiments confirmed their high efficiency as contrasting agents in the reconstruction of the images of internal tissues of living organisms and pathological processes. Even with the modern level of technical development, it is not always possible to sufficiently depict the studied tissue. To enhance the signal from the pathological nidus in the organism special substances are now used that penetrate the area affected and enhance the contrast. Cadmium salts are often used for these purposes, yet this is not a safe practice. Therefore the scientists have developed organic paramagnetic substances on the basis of non-toxic and stable nitroxyls. The stumbling point in the development and application of such substances has been that the majority of known nitroxyl compounds do not dissolve well in water or are unstable when in contact with living tissues and, as a result, lose their paramagnetic properties (which give the contrast of the tomographic image). The chemists overcame these difficulties, having turned nitroxyl radicals into imidazoline nitroxyl radicals, which are usually stable in liquid media. These are the first examples of a paramagnetic organic nature that could be effective means for magnetic resonance tomography.