A Room PET Scanner for Natural Environment Neuroscience Research

A room size PET scanner for neuroscience research is proposed in which subjects can move about freely in a natural environment. This scanner, termed RoomPET, would open new frontiers in the study of dynamic brain function. The key to a feasible system is PET detectors with a limited vertical dimension that may translate up and down to keep the brain in the field of view. Head position can be tracked by an array of video cameras, providing real-time data to guide detector motion and for motion-corrected image reconstruction. For a point in the center of the room and centered within the vertical field of view of the detectors, geometric sensitivity ranges between 4 and 18% for room widths of 2 to 3 m and detectors with vertical dimensions of 15 to 40 cm. Spatial resolution is dominated by annihilation photon non-colinearity due to the large detector separation. This non-colinearity contribution for F-18 is 4.4 and 6.6 mm full width at half maximum (FWHM) at the center of 2 ×2 and 3×3m
²
rooms, respectively, for a line of response orthogonal to the opposite walls. With pixelated scintillation crystal elements 2 mm on a side the system resolution for F-18 radiotracers is estimated at 4.5 and 6.7 mm FWHM for room widths of 2 and 3 m, respectively. A RoomPET system would advance the understanding of brain function in healthy humans and in those with neurological diseases, disorders and brain injury.