RPC-PET: a new very high resolution PET technology

In this study we present experimental and simulated results from a first prototype of a positron emission tomography (PET) system based on the resistive plate chamber (RPC) technology-a gaseous particle detector developed for high energy physics. The prototype is aimed at validating the expectations, derived from simulations, of a system with sub-millimeter spatial image resolution and no parallax error, which may be useful for the imaging of small animals. By imaging a point-like ²²Na source in the transaxial plane, an intrinsic spatial resolution of 0.52 mm FWHM was demonstrated for a system diameter of 60 mm. A corresponding image spatial resolution of 0.5 mm FWHM was obtained using the standard algorithm of filtered back projection and 0.4 mm FWHM after reconstruction by an ML-EM type algorithm. An optimized complete system was simulated to evaluate sensitivity and system count rate performance for the imaging of mice, suggesting a sensitivity up to 2.1 % at the centre of the field of view and a peak NEC rate up to 320 Kcps for a total activity of 100 MBq in the phantom.