PET gantry simulation: Concepts and methods for inexpensively reproducing the PET data acquisition environment using a single PC with the PDT card

A custom PCI-application hardware card installed in a server-class PC forms a system to aid with PET data acquisition testing. This system: 1) is called the PET Gantry Simulator PC, 2) mimics most random processes as output in a coincidence-event stream from a PET detector array via fiber optics, 3) will primarily aid the development, testing and validation of PET data acquisition systems, and 4) uses a conventional server-class PC running Windows XP. This Gantry Simulator PC contains a conventional RAID disk system for fast read access into large files. In addition, this PC contains a custom-designed PETLINK™ DMA Transceiver (PDT) card with fiber-optic transceivers and PCI interface. The fiber-optic output from this PDT-in-Gantry-Simulator effectively reproduces - in several important ways - the coincidencedetection data-stream output of many types of real PET detector arrays. Significantly, this PETLINK-compatible fiber-optic retransmission of PET data (real or synthetic) can be repeated exactly and endlessly. Typically, real 64-bit PET coincidence-event and tag packet data - i.e. data collected previously in list mode form - are initially loaded onto this RAID. Under control of Windows-based custom application code, this data can be read from the RAID, input to the PDT via the PCI bus, and retransmitted from the PDT via fiber optic cables and at controlled rates. The rates of packet re-transmission can either be set to mimic that of the original PET acquisition or can be arbitrarily modified to conform to other desired scenarios - i.e. constant rate, bolus injections, half-life decay, etc. Note that the various rates of packet re-transmission are typically only updated by the PDT hardware with each passing millisecond. In one operational mode, the PDT card can be set to mimic even the Poisson distribution of the individual time delays between consecutive re- transmitted coincidence-event packets. The effective range of packet transmission rates for the Gantry Simulator approaches a low of 1 kHz and a high of 1 to 8 MHz or more.