A HOTLink/Networked PC Data Acquisition and Image Reconstruction System for a High-Resolution Whole-Body PET With Respiratory or ECG-Gated Performance

An ultrahigh-resolution positron emission tomography (PET) camera in whole-body scanning or gated imaging study needs super computer-processing power for creating a huge sinogram as well as doing image reconstruction. A fast HOTLink serial bus attached to networked cluster personal computers (PC) has been developed for this special purpose. In general, the coincidence data from a PET camera is unidirectional; therefore, an additional daisy-chain bus using high-speed HOTLink (400 Mb/s, Cypress Semiconductor, inc.) transmitters and receivers is designed to carry the coincidence data to the entire networked (LAN) computers (PCs), the data from HOTLink are interfaced to a PC through a fast PCI I/O board (80 Mbyte/s). The overall architecture for the image acquisition and reconstruction computing system for a whole-body PET scanning is a pipeline design. One PC will acquire sinogram data for one bed position, and after completion of data acquisition that PC will begin to reconstruct the image. Meanwhile, another PC in the network will start data acquisition for the next bed position. The image results from the previous PC will be sent to a master computer for final tabulation and storage through the standard network, and then it will be free for processing a new bed position. In gated respiratory or gated ECG imaging study, each cycle is divided into many time segments and each PC will be reconfigured for processing one specified time-segment image. The authors are developing a high-resolution PET camera with 38,016 BGO crystal elements that requires 1 to 2 GB sinogram memory. This HOTLink/networked structure design also allows them to distribute the huge sinogram real-time binning into several PCs; the image reconstruction can be done in parallel.