The innovative Opaque-Technology (OTech) derived from the LiquidO detection opens an unprecedented synergy between leading experts in medical and neutrino here proposing a new paradigm for medical imaging based on high precision antimatter ß+ detection. We propose to construct the first opaque liquid positron emission tomography system (LPET) in order to demonstrate and quantify its ability to fully characterise the annihilation pattern of both ß+ and ?-ß+ sources exploiting the latest machine learning techniques for maximal performance. The additional prompt-? will further improve the reconstructed annihilation origin while enabling the potential for direct tissue probing thanks to the accurate study of the positronium formation rate and lifetime dependent on the ß+ contact to the tissue structure including the development of metabolic disorders. Thus, our LPET prototype will explore the limits of today’s PET imaging while articulating a unique innermost tissue insight.