Development and Performance Evaluation of a Time-of-Flight Positron Emission Tomography Detector Based on a High-Quantum-Efficiency Multi-Anode Photomultiplier Tube

Abstract

We present the development and performance evaluation of time-of-flight (TOF) positron emission tomography (PET) detector modules designed for a proof-of-concept prototype of a TOF PET scanner based on the advanced high-quantum-efficiency (high-QE) multi-anode photomultiplier tube (PMT) (Hamamatsu H10966A-100 with super-bialkali photocathode) coupled with LGSO scintillation crystals (3 mm $ \times$ 3 mm $\times$ 20 mm) whose cross section is smaller than that of crystals used in current clinical scanners. Compact dedicated front-end analog electronics combined with the high packing density and large effective area of the multi-anode PMT allow a modular detector design and thus a flexible and extendible geometry of the PET system. We optimized the electrical parameters (trigger threshold level, high voltage of PMTs, and amplifier gain) to yield the best timing resolution and acquired excellent flood map quality, energy resolution, and timing resolution with the optimal setup; the average distance-to-width ratio (DWR) of crystal peaks for 40 detectors was 5.3 ${\pm}$ 1.0, and the average energy resolution and coincidence resolving time (H10966A-100 vs. H10966A-100) were 11.04 ${\pm} $ 0.80% (FWHM) and 341 ${\pm}$ 45 ps (FWHM) respectively. The detector modules developed in this study and optimized their parameters to yield the best detector performance will be useful for the future development of the next generation TOF PET scanners based on them.