Positron emission tomography: its 65 years and beyond

Positron emission tomography (PET) is a well-established imaging technique for “in-vivo” molecular imaging. In this review, after a brief history of PET, its physical principles and the technology developed for bringing PET from a bench experiment to a clinically indispensable instrument are presented. The limitations and performance of the PET tomographs are discussed, both for the hardware and software aspects. The status of the art of clinical, pre-clinical and hybrid scanners (i.e., PET/CT and PET/MR) is reported. Finally, the actual trend and the recent and future technological developments are illustrated. The current version of this paper is the second edition of the original version published in 2016 (Rivista del Nuovo Cimento, Vol 39(4) 2016, pp. 156–213). The authors decided to keep the same structure of the paper, operating corrections of some typos, and adjustments. However, we added a description of the most recent PET developments that took place in the last 10 years completed with the addition of the most relevant references. These topics are now described in detail and cover the last two chapters of the paper.