Fast and accurate nearest-neighbor 3-D LOR rebinning: the PDR card applied to a rotating 5-head LSO-panel-detector PET prototype

On-line processing for mapping coincidence LOR (lines of response) into the 3-D projection-bin space is a critically important requirement for clinical-grade positron emission tomography - i.e. P.E.T. The PDR (PETLINK™ DMA Rebinner) is a PCI card designed for general-purpose, rapid-yet-accurate, on-line LOR-to-bin mapping of PET coincidence data. In this article, the application of the PDR to a continuously-rotating 5-head LSO-panel-detector PET prototype is described. A photo of the production-ready PDR card is shown. A pipelined architecture is presented for the PDR as applied to this 5-head prototype. Using software emulation of this pipeline and real list-mode data collected from both needle and point sources, results show the superior capacity of the PDR for more accurate 3-D LOR mapping. By contrast, needle-source and point-source projection data mapped using software emulation of earlier hardware architectures (Rebinner/PFT) show comparatively poor registration for 3-D axial LOR-to-bin mapping. For a 0.05 cm diameter point source located 30 cm off-center of the field of view (FOV), this better PDR registration results in a FWHM resolution of 0.66 cm - an improvement from the earlier 1.1 cm. In addition, the PDR hardware has the capacity to support nearly double the on-line packet-processing throughput over the earlier Rebinner/PFT design.