Abstract
Abstract
Background
Small-animal positron emission tomography (PET) imaging is commonly employed in biomedical research to accelerate the translation of the discovery in the fields of molecular and cellular biology into the clinical practice. Its performance and cost are largely dependent on the employed detectors and electronics. In this work, a new electronics scheme aiming to simplify PET electronics is evaluated using two dual-ended readout PET detectors with high spatial resolution.
Methods
The first detector is composed of a 16 × 16 lutetium–yttrium oxyorthosilicate (LYSO) array with crystal dimensions of 1.45 × 1.45 × 20 mm³. The second detector is composed of a 26 × 26 LYSO array with crystal dimensions of 0.75 × 0.75 × 20 mm³. Both LYSO arrays are dual-ended read out by 8 × 8 Hamamatsu S14161-3050HS-08 silicon photomultiplier (SiPM) arrays with a sensitive pixel area of 3 × 3 mm
2
and a pitch of 3.2 mm. The 64 outputs of the SiPM array are read out by a highly multiplexed row–column summation network to convert them to four position-encoded energy signals. The four signals are processed by a commercial 32-channel MPT2321 ASIC. The flood map, energy resolution, depth of interaction (DOI) resolution, and timing resolution of the detectors are measured.
Results
The first detector provided a flood map with all crystals resolved and an average peak-to-valley ratio (PVR) of 3.59 was obtained for the flood map quality, an energy resolution of 14.2 ± 0.4%, a DOI resolution of 3.04 ± 0.37 mm and a detector timing resolution (DTR) of 2.24 ± 0.10 ns. The second detector provided a flood map with all crystals resolved and an average PVR of 2.61 was obtained, an energy resolution of 15.3 ± 0.7%, a DOI resolution of 2.56 ± 0.46 mm and a DTR of 2.38 ± 0.20 ns.
Conclusion
The electronics scheme evaluated in this study provides competitive energy and DOI performance for high-resolution small-animal PET detectors while significantly reducing electronics channel count and system complexity.