Gigabit High Speed TCP Data Transmission for Positron Emission Tomography

The development of a new tri-modality preclinical Computed Tomography apparatus (¿CT), Single Photon Emission Computed Tomography apparatus (¿SPECT) and Positron Emission Tomography apparatus (¿PET) dedicated to small animal imaging tomography is underway in the group ImaBIO at the Institut Pluridisciplinaire Hubert Curien. The ¿CT and ¿SPECT scanners are working quite fine and now used by biologists. Now the team is concentrated on the building of the ¿PET part of the imaging platform. PET Data AcQuisition (DAQ) requires in particular the detection of coincident events. In the developing ¿PET, the coincidence window is less than 1 ns. This constraint and the number of detection channels (6144) discredit an hardware solution. Moreover the lack of an hardware trigger dictates the readout of all the detected events and an absolute time stamp on each event. In this context the development of a Gigabit High Speed Transmission Control Protocol / Internet Protocol (TCP/IP) Data Transmission System was considered. Out of usual solutions involving high level language and expansive real time operating system, a solution based on the use of a Field Programmable Gate Array (FPGA) with an embedded processor programmed in C was chosen. The preliminary results of the first realized system show that the maximum bandwidth of the Gigabit Ethernet is reached with embedded processor available for more than 20% of time.