PhytoPET: Design and initial results of modular PET for plant biology

We have developed a positron emission tomography (PET) system designed specifically for plant imaging in Phytotron at Duke University. Initial evaluation of a PhytoPET system to image the biodistribution of the positron emitting tracer ¹¹C in live plants is presented. The mechanical arrangement of the detectors is designed to accommodate the unpredictable and random distribution in space of the plant parts such as stems, leaves, and roots. Prototyping such a system requires a completely new PET system design strategy different from preclinical and clinical applications. This PhytoPET design allows flexible arrangements of PET detectors based on individual standalone detector modules built from single 5 cm × 5 cm Hamamatsu H8500 position sensitive photomultiplier tubes. Each H8500 is coupled to a L YSO:Ce scintillator array composed of 48 × 48 elements that are 10 mm thick with a 1 mm pitch. Initial results provide planar PET images from two different arrangements (1 × 4 or 2 × 2) for flexible imaging capability.