The initial design and feasibility study of an affordable high-resolution 100-cm long PET

Abstract

This is a design and feasibility study of an affordable high-resolution 100-cm long PET covering the entire body (EBPET) for imaging head-&-torso in one fixed bed position. Our design studies show that EB-PET may image the entire body in 2–4 minutes with a low 2.5-mCi FDG dose. The high patient throughput may lower the cost of wholebody imaging and the low dose would allow more frequent cancer-management monitoring. EB-PET can capture dynamic wholebody timeactivity images and arterial (cardiac) input function concurrently to yield quantitative metabolic images for the wholebody to improve diagnosis and to measure wholebody systemic side effects of therapy. Dynamic imaging using EB-PET may also unshackle wholebody PET imaging from the static FDG-type of tracers required by current PET to new classes of more dynamic tracers. The EB-PET detection system is based on the latest generation of the low-cost BGO detector prototypes developed in our laboratory which can decode 121 BGO crystals per PMT (39-mm diameter), thereby enabling this very large system to use only 1768 PMT for its 205,700 high resolution crystals (3.5 × 3.5 × 20 mm). The system resolution and NES characteristics were also calculated with Monte Carlo (MC) simulations (GATE/GEANT) for point sources, NEMA NES phantom and wholebody Turkington phantoms. Prototype detectors achieved a 15% energy resolution and clearly decoded 3.5x3.5mm detectors. With such data, MC simulations show that the central transaxial image resolution is 3.2mm (4.4mm) for 5 cross-ring coincidences (274 cross-ring coincidences), while at 10-cm transaxial radius, the image resolution is 4.2mm (5.1mm).