Abstract: A method and a device for compensation-based measurement of the alpha and/or beta radioactivity in a gamma background noise comprising a compensation probe comprises a first sensor allowing the measurement of the alpha and/or beta and gamma radioactivity and a second sensor not allowing the measurement of the alpha and/or beta radioactivity but allowing the measurement of the gamma radioactivity; wherein the sensors are arranged to be exposed substantially to the same gamma background noise; measurement biases being associated with the geometric arrangement of the sensors on account of the anisotropy of the gamma radiation; the measurement system determines the alpha and/or beta radioactivity by compensation comprising a subtraction between the measurement of alpha and/or beta and gamma radioactivity and the gamma measurement, the compensation minimizing the measurement biases associated with the geometric arrangement of the sensors.

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.

Abstract: A method for analyzing spectrometric measurements, said measurements C={c1, . . . , cr} being organized in a histogram, said histogram being made up of accumulation channels, a channel j corresponding to an energy interval Bj, comprises at least three processing steps. A first step determines, for each accumulation channel j, distributions p representative of the amplitude and Z representative of the position of the Dirac pulses that make up the normalized spectrum of peaks as well as distributions q representative of the Pólya tree characterizing the normalized background spectrum, said elements being obtained by Gibbs sampling. A second step detects significant channels, said detection being performed by application of a Kolmogorov-Smirnov test for each accumulation channel of the histogram on the basis of the results of the first step.