Abstract:

A brief historical review of Time-of-Flight (TOF) Positron Emission Tomography (PET) will be presented, including the recent development in silicon photomultipliers (SiPM), which resulted in improved TOF performance. The principles of TOF PET physics and a discussion of the technical and clinical advantages of TOF PET compared to conventional PET will be presented: the concept of time resolution and its effect on TOF gain in signal-to-noise ratio (SNR), together with other properties such as reconstruction robustness to inconsistent data, convergence, and convergence speed. Other advanced reconstruction methods and innovations will be discussed, such as resolution recovery methods, data driven methods for motion correction, and the recent introduction of deep learning in different aspects of PET.

From the hardware point of view, we will review the most recent and exciting evolution toward long axial field-of-view PET/CT scanners, or total body PET: design trade-off, characteristics and performance, challenges and advantages, including new applications enabled by very high performance TOF PET scanners in the field of low count imaging, theranostics and monoclonal antibodies imaging, and dynamic and parametric imaging with simultaneous coverage of multiple organs.

Finally, we will briefly comment on the near future of PET and TOF PET, in terms of possible technology development and needs of fundamental research to push the field forward.