Ultra Fast Frame Based Parallel Reconstruction (FBPR) for dynamic 3D PET study

Dynamic study using positron emission tomography (PET) is a powerful tool to analyze neurochemical and neuropharmachological processes in vivo. However, full-reconstruction (including histogramming, precorrections, and reconstruction) for dynamic PET studies is a very time-consuming task, especially with PET scanners of high resolution and high sensitivity, such as HRRT (high resolution research tomograph) developed by Siemens/CTI. For example, the full-reconstruction time for the dynamic study of 32 frames using HRRT takes above 21 hours. To solve this excessive computational time problem, we have developed the ultra fast frame based parallel reconstruction (FBPR) system by effectively expanding the symmetry and SIMD based projection-backprojection (SSP) algorithm[1] into a cluster system. In contrast to conventional cluster system approaches, the FBPR system uses the frame as the granularity of parallelization for dynamic study reconstruction, and simultaneously reconstructs maximum frame images same as the number of computing nodes. We applied the FBPR system into HRRT and tested the performance of the system. Compared with the existing cluster reconstruction system, the FBPR system enhanced the performance by up to twenty five times and also provided the same quality reconstructed images.