“…In this article, we advocate the opinion that total-body PET systems, thanks to their high imaging sensitivity and high time resolution, open up the prospect of translating positronium imaging into clinics. KEYWORDS positronium imaging, biomarkers, medical imaging, J-PET, multi-photon PET, total-body PET, theranostics, hypoxia Positronium imaging is a newly invented diagnostic method [1][2][3][4][5][6][7] with promising potential to improve specificity in the assessment of tissue pathology in vivo at the molecular level based on information available from the data collected by the upcoming generation of multi-photon (multi-gamma) PET systems [2,4,7,8].…”