Maximum likelihood image reconstruction for SPECT
Maximum likelihood image reconstruction for SPECT
复制标题
SPECT 的最大似然图像重建
DOI：
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发表时间：
1985
期刊：
影响因子：
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通讯作者：
W. Rogers
中科院分区：
文献类型：
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作者：
S. Vishampayan;J. Stamos;R. Mayans;K. Koral;N. Clinthorne;W. Rogers
离散估计算法是感兴趣的SPECT，因为它们很容易适应非标准的采样几何形状，可以明确地设计为各种收敛标准。此外，已知的衰减图和系统响应函数可以被并入重建框架中。以前的工作的最大似然估计已被改编为圆形扇束的SPRINT几何形状。衰减和射线轮廓都包括在概率系数中。研究了将修正项提高到一个幂对收敛性的影响。结果进行了比较，其他两个迭代算法，ART和CSIM，使用相同的加权矩阵和实验数据从德伦佐幻影。与ART或CSIM相比，最大似然算法给出了更优的上级图像。图像表现出优异的信噪比和高分辨率。通过增加乘法校正的指数，收敛速度显着增加。对校正进行平方得到的第二次迭代结果上级优于具有第一次幂校正的第四次迭代。三次幂校正显示出在六次迭代后振荡的趋势，但是图像已经上级通过九次迭代的任何其他算法产生的图像。最大似然算法看起来更适合SPECT图像重建，并且通过增加校正项的功率，其收敛速度显著增加。«少
Discrete estimation algorithms are of interest in SPECT because they are readily adapted to nonstandard sampling geometry and can be explicitly designed for a variety of convergence criteria. Moreover, known attenuation maps and system response functions can be incorporated into the reconstruction framework. The maximum likelihood estimator of a previous work has been adapted to the circular fan beam geometry of SPRINT. Both attenuation and ray profile are included in the probability coefficients. The effect on convergence of raising the correction term to a power was also investigated. Results were compared to two other iterative algorithms, ART and CSIM, using identical weighting matrices and experimental data from a Derenzo phantom. The maximum likelihood algorithm gave superior images compared to either ART or CSIM. The images demonstrated excellent signal-to-noise properties and high resolution. Convergence rate was dramatically increased by increasing the exponent of the multiplicative correction. Squaring the correction gave a result at the second iteration superior to the fourth iteration with first power correction. Third power correction showed a tendency to oscillate after six iterations, but the image was already superior to any produced by either of the other algorithms through nine iterations. The maximum likelihood algorithm appears well suitedmore » for SPECT image reconstruction and its convergence rate is dramatically increased by increasing the power of the correction term.« less