Positron Emission Tomography (PET) is a nuclear imaging modality based on the detection of two coincident photons resulting from the annihilation of positrons emitted by radioisotopes decaying by emission-β. These radioisotopes are inserted into molecular probes based on an organic substrate (e.g. glucose, ketone, protein, peptide, antibody, etc.). Following the administration of the radiopharmaceutical, the probe is distributed through the body via the circulation and accumulates in different organs, reflecting the perfusion and the metabolic or biochemical activity of the tissues or cells. With the application of a pharmacokinetic model to describe the pathway and possible transformation of the probe, it is possible to extract quantitative information about biochemical processes within tissues or organs. Thus, PET is one of the most effective molecular imaging modalities because it allows the quantification of biological and biochemical processes in vivo with unparalleled sensitivity. Complementing the anatomical/functional explorations provided by magnetic resonance imaging (MRI), PET allows the exploration of the regional biochemistry of the brain at picomolar concentrations, therefore generally sub-pharmacological. We have come to this point today with the research contribution of many scientists over the years. IR&T is proud to be among the leaders of the future of this technology.