Abstract: A method for determining functional volumes for the search for kinetics representing the trend of concentration of a radioactive tracer in an area of biological tissue, being applied to spatial components comprises the following steps applied iteratively according to a Markov chain Monte-Carlo scheme: generation of a set K0? made up of a set of candidate kinetics associated with values of probability of appearance, depending on the concentration ? of radioactive tracer; a labeling step during which, for each spatial component of index K, the probabilities of selection of the kinetics of the set K0? are weighted by introducing a function ?k representative of the concentration of radioactive tracer in this component to obtain a set of indicative values, an indicative value Dk designating the kinetic with which the spatial component K is associated; construction of functional volumes, a functional volume VFj made up of the set of spatial components which share the same indicative value Dk.