A system for the 3D reconstruction of retracted-septa PET data using the EM algorithm
A system for the 3D reconstruction of retracted-septa PET data using the EM algorithm
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DOI：
10.1109/nssmic.1994.474573
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发表时间：
1994-10
期刊：
影响因子：
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通讯作者：
Calvin;Johnson;Yuchen Yan;R. Carson;R. Martino;M. Daube-Witherspoon
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文献类型：
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作者：
Calvin;Johnson;Yuchen Yan;R. Carson;R. Martino;M. Daube-Witherspoon
作者已经实现了EM重建算法，用于当前一代缩进隔片PET扫描仪的体积采集。虽然该软件是为GE Advance扫描仪设计的，但它可以轻松地适应其他3D扫描仪。重建软件是为具有128个计算节点的Intel iPSC/860并行计算机编写的。该算法在32个处理器上运行，每次迭代需要大约55分钟来重建128/spl times/128/spl times/35图像。实施中没有使用投影数据压缩方案或其他近似方法。广泛使用EM系统矩阵（C/sub ij/）对称性（包括8重面内对称性、2重轴向对称性和轴向平行线冗余）将存储成本降低了188倍。该并行算法对按基对称角分解的分布式投影数据进行运算。对称运算符将C/sub ij/ chord复制并索引为特定对称所需的形式。使用异步读取、查找表和优化的图像索引可以提高计算性能。3D算法的收敛性与2D算法的收敛性的比较研究正在进行中。>
The authors have implemented the EM reconstruction algorithm for volume acquisition from current generation retracted-septa PET scanners. Although the software was designed for a GE Advance scanner, it is easily adaptable to other 3D scanners. The reconstruction software was written for an Intel iPSC/860 parallel computer with 128 compute nodes. Running on 32 processors, the algorithm requires approximately 55 minutes per iteration to reconstruct a 128/spl times/128/spl times/35 image. No projection data compression schemes or other approximations were used in the implementation. Extensive use of EM system matrix (C/sub ij/) symmetries (including the 8-fold in-plane symmetries, 2-fold axial symmetries, and axial parallel line redundancies) reduces the storage cost by a factor of 188. The parallel algorithm operates on distributed projection data which are decomposed by base-symmetry angles. Symmetry operators copy and index the C/sub ij/ chord to the form required for the particular symmetry. The use of asynchronous reads, lookup tables, and optimized image indexing improves computational performance. Studies of the convergence of the 3D algorithm in comparison with that of the 2D algorithm are underway.>