RPC-PET: A new very high resolution PET technology

In this paper, 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 submillimeter spatial image resolution and no parallax error, which may be useful for the imaging of small animals. By imaging a point-like Na-22 source in the transaxial plane, an intrinsic spatial resolution of 0.52 mm FWHM was demonstrated for a system diameter of 60 mm, validating positron range simulations by other authors. A corresponding image spatial resolution of 0.51 mm FWHM was obtained using the standard algorithm of filtered backprojection (FBP) and 0.31 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 center of the field of view and a peak noise equivalent count rate (NECR) up to 320 Kcps for a total activity of 88 MBq in the phantom.