MAP reconstruction for Fourier rebinned TOF-PET data.
MAP reconstruction for Fourier rebinned TOF-PET data.
复制标题
DOI：
10.1088/0031-9155/59/4/925
复制
发表时间：
2014-02-21
影响因子：
3.5
通讯作者：
Leahy RM
中科院分区：
文献类型：
--
作者：
Bai B;Lin Y;Zhu W;Ren R;Li Q;Dahlbom M;DiFilippo F;Leahy RM
飞行时间（TOF）信息提高了正电子发射断层扫描（PET）中的信噪比。处理TOF-PET正弦图的计算成本显著高于非TOF数据，因为每条响应线中的数据被划分在多个飞行时间区间中。这种额外的成本促使人们研究将TOF数据重组为利用TOF数据中固有冗余的低维表示的方法。我们以前开发的近似傅立叶方法，rebin TOF数据到3D nonTOF或2D nonTOF格式。我们将这些方法分别称为FORET-3D和FORET-2D。在这里，我们描述了最大后验（MAP）估计与FORET重组数据使用。我们首先推导出重组数据方差的近似表达式。然后，我们使用这些结果重新调整数据，使方差和均值近似相等，使我们能够使用泊松似然模型进行MAP重建。从这些重组数据的MAP重建使用系统矩阵，其中检测器响应模型考虑重组的影响。使用这些方法，我们比较性能的FORET-2D和3D TOF和nonTOF重建使用体模和临床数据。我们的幻影结果显示，在匹配的噪声水平，使用FORET相比，从原始TOF数据重建的对比度恢复的小损失。临床实例显示FORET图像与从原始TOF-PET数据获得的图像在质量上相似，但在匹配分辨率下方差略有增加。与3D TOF MAP相比，使用FORET 3D +MAP和FORET 2D +MAP的重建时间分别减少了5倍和30倍，这使得这些方法对临床应用具有吸引力。
Time-of-flight (TOF) information improves signal to noise ratio in Positron Emission Tomography (PET). Computation cost in processing TOF-PET sinograms is substantially higher than for nonTOF data because the data in each line of response is divided among multiple time of flight bins. This additional cost has motivated research into methods for rebinning TOF data into lower dimensional representations that exploit redundancies inherent in TOF data. We have previously developed approximate Fourier methods that rebin TOF data into either 3D nonTOF or 2D nonTOF formats. We refer to these methods respectively as FORET-3D and FORET-2D. Here we describe maximum a posteriori (MAP) estimators for use with FORET rebinned data. We first derive approximate expressions for the variance of the rebinned data. We then use these results to rescale the data so that the variance and mean are approximately equal allowing us to use the Poisson likelihood model for MAP reconstruction. MAP reconstruction from these rebinned data uses a system matrix in which the detector response model accounts for the effects of rebinning. Using these methods we compare performance of FORET-2D and 3D with TOF and nonTOF reconstructions using phantom and clinical data. Our phantom results show a small loss in contrast recovery at matched noise levels using FORET compared to reconstruction from the original TOF data. Clinical examples show FORET images that are qualitatively similar to those obtained from the original TOF-PET data but a small increase in variance at matched resolution. Reconstruction time is reduced by a factor of 5 and 30 using FORET3D+MAP and FORET2D+MAP respectively compared to 3D TOF MAP, which makes these methods attractive for clinical applications.
登录
查看更多内容
影响因子：
10.6
作者：
Pratx G;Chinn G;Olcott PD;Levin CS
通讯作者：
Levin CS
DOI：
10.2967/jnumed.109.063016
发表时间：
2009-08
期刊：
Journal of nuclear medicine : official publication, Society of Nuclear Medicine
影响因子：
--
作者：
Kadrmas DJ;Casey ME;Conti M;Jakoby BW;Lois C;Townsend DW
通讯作者：
Townsend DW
影响因子：
14.9
作者：
Ollinger, JM;Fessler, JA
通讯作者：
Fessler, JA
影响因子：
10.6
作者：
Qi, JY;Leahy, RM
通讯作者：
Leahy, RM
影响因子：
3.5
作者：
Qi, JY;Leahy, RM;Farquhar, TH
通讯作者：
Farquhar, TH