Advanced detector for Time-of-Flight PET based on Cherenkov radiation

Positron emission tomography (PET) is one of the most important diagnostic tools in medicine, allowing three-dimensional imaging of functional processes in the body. It is based on detection of two gamma rays originating from the point of annihilation of the positron emitted by a radio-labelled agent. Standard PET scanners have an axial length of about 20 cm and can only use a fraction of the activity in the body. This fraction may be increased by extending the axial length of the device, which is associated with a significant increase in its price, which, in turn, is largely determined by the cost of the scintillator. Development of devices for imaging of the whole body is one of the hottest trends in functional and molecular imaging.

The contrast of the image can be improved by reducing the fraction of background combinations, mostly from random coincidences, and from events where gamma rays scatter in the tissue, in special PET devices, measuring the time of flight of gamma rays (TOF-PET, Time-Of-Flight PET). Their accuracy is between 250 ps and 400 ps, which can already significantly improve the contrast in imaging of large objects. One of the major limitations to further improvements of the timing resolution is the response time of the scintillator crystal. The search for new materials and mechanisms of light emission is another direction of intensive development.