Next generation PET imager

The shift towards early diagnosis and prevention in medicine necessitates high-performing PET imaging systems with improved sensitivity and specificity. To achieve this, additional time-of-flight measurements in PET enhance the signal-to-noise ratio and enable the construction of better-performing systems. However, the timing resolution of PET systems is limited by several factors, such as slow scintillation response time, optical photon travel time spread, number of detected scintillation photons, and timing precision of the photo-sensor and fast readout electronics. Although there have been efforts to develop new scintillators for PET, this contribution focuses on optimizing photo sensors and readout electronics. The authors integrated high-performing HD-NUV-MT silicon photomultipliers from FBK with novel low-power FastIC ASICs for fast-timing applications. They constructed a pair of 16-channel gamma detector modules and placed them in a coincidence setup, demonstrating very high coincidence timing resolution below 100 ps FWHM. This achievement enables the construction of high-performing PET detectors with incomplete sampling and simplified systems consisting of flat panel detectors that can be easily combined in larger systems. The authors simulated the performance of an imager comprising two 120 cm × 60 cm panels of segmented 20 mm thick LYSO crystal arrays read by dual-sided readout with fast timing and imaged a human XCAT phantom. They demonstrated that such a system, consisting of much less scintillator material compared to a total body PET imager with a standard opening, exhibits excellent performance. Overall, this approach provides a promising path toward developing highly sensitive and specific PET imaging systems that can aid in early disease diagnosis and prevention.