The dynamics of the protons relaxation processes in the biological tissues MR imaging problem is investigated. Response signal for the volume element containing several types of biological tissues is considered. The dependence of the response signal spin-spin and spin-lattice relaxation times on the molecular local environment singularities is analyzed. The possibility of obtaining the different types biological tissues areas separation by carrying out adapted signal processing which is based on taking into account the peculiarities of their properties is shown. Thanks to the implemented method of data processing, the clarity of selection of such types of biological brain tissues as white matter, gray matter and tissues in the pathological country was obtained.