Improvements to Positron Emission Tomography Sensitivity via Double-Ended Readout

Positron emission tomography (PET) is a powerful, noninvasive nuclear imaging technique used extensively for identifying cancer and brain disease. The sensitivities of clinical PET scanners have improved considerably in recent years, at pace with advancements in scintillator and photodetector technologies. In particular, significant improvements have been made in the coincidence resolving time (CRT or “time resolution”) of PET scanners, resulting in tighter event localization and thus better signal-to-noise ratios. However, optimization of time resolution conventionally requires short scintillator crystals, which allow more gamma rays to escape, diminishing the overall sensitivity. An alternative but clinically unrealized technique for achieving excellent time resolution is the coupling of a second photodetector to the front face of long scintillator crystals. Through Monte Carlo simulations, we indicate that a PET scanner employing this technique may reach a CRT below 200 ps, far outperforming current state-of-the-art scanners.