Sci‐Fri PM Imaging‐10: LabPETtm: A Second‐Generation APD‐Based Digital Scanner for High‐Resolution Small Animal PET Imaging

LabPET™ is a novel APD‐based PETscanner with quasi‐individual crystal readout and highly parallel digital architecture for high‐performance in vivo molecular imaging of small animals. It consists of 16 rings, 16.2 cm in diameter, each formed by 192 2×2×(9.9–11.3) mm3 scintillators assembled in LYSO/LGSO phoswich pairs read out by an avalanche photodiode(APD). The field of view extends up to 110 mm in diameter by 37.5 mm axially. The dual‐crystal readout scheme avoids resolution degradation due to light‐ or charge‐sharing and enables very high singles count rates with low dead time. Advanced parallel algorithms for signal processing and analysis implemented in high‐performance programmable devices perform crystal identification, energy discrimination and time stamping of individual pixels in real‐time. Virtually error‐free crystal identification is achieved using an auto‐regressive moving average method. Coincidence events are sorted in real‐time and recorded in list‐mode, together with scanner status information and animal physiological data. The intrinsic spatial resolution (both radial and axial) at the FOV center is 1.2 mm FWHM (2.3 mm FWTM). The 1.2‐mm diameter hot rods can be clearly resolved in images of a resolution phantom. Preliminary time resolutions of 2.5 and 3.9 ns FWHM were obtained respectively for LYSO‐LYSO and LGSO‐LGSO coincidences using an auto‐regressive least‐mean square timing algorithm. The system is implemented with ancillary devices (injectors, life‐sign monitors, blood counter…) controlled through a centralized user‐interface, offering a fully integrated solution for performing demanding molecular imaging investigations with increased throughput in a busy research environment.