Joint Activity and Attenuation Reconstruction From Multiple Energy Window Data With Photopeak Scatter Re-Estimation in Non-TOF 3-D PET
Joint Activity and Attenuation Reconstruction From Multiple Energy Window Data With Photopeak Scatter Re-Estimation in Non-TOF 3-D PET
复制标题
DOI：
10.1109/trpms.2020.2978449
复制
发表时间：
2020-07-01
影响因子：
4.4
通讯作者：
Thielemans, Kris
中科院分区：
文献类型：
--
作者：
Brusaferri, Ludovica;Bousse, Alexandre;Thielemans, Kris
仅混合 PET-MR 和 CT 不可用或不推荐的系统才对根据正电子发射断层扫描 (PET) 数据估计衰减感兴趣。然而，当使用来自单个能量窗口的数据时，基于发射的非飞行时间 (TOF) PET 衰减校正 (AC) 方法会受到“串扰”伪影的影响。基于早期的工作，本文探讨了可以通过使用多个能量窗口来减少串扰的假设。我们提出了一种使用多个能量窗口同时估计活动图像和衰减图像以及 PET 采集测量数据的散射分量的算法。测量模型是 3-D 的，并考虑了 PET 探测器的有限能量分辨率；它仅限于单次散射。将所提出的使用光峰散射重估计算法的基于能量的活动和衰减的同时最大似然重建与使用光峰散射重估计的活动和衰减的单能量窗口同时最大似然重建进行比较。该评估基于使用西门子 mMR 扫描仪特性的模拟。研究了不同复杂性的模型。特别是，使用 3-D XCAT 躯干模型来评估肺部区域内衰减值的修复。结果表明，当使用多个能量窗口时，非 TOF 活动最大似然重建和衰减重建中存在的串扰显着减少，并表明所提出的方法值得进一步研究。
Estimation of attenuation from positron emission tomography (PET) data only is of interest for hybrid PET-MR and systems where CT is not available or recommended. However, when using data from a single energy window, emission-based non-time-of-flight (TOF) PET attenuation correction (AC) methods suffer from "cross-talk" artifacts. Based on earlier work, this article explores the hypothesis that cross-talk can be reduced by using more than one energy window. We propose an algorithm for the simultaneous estimation of both activity and attenuation images, as well as, the scatter component of the measured data from a PET acquisition, using multiple energy windows. The model for the measurements is 3-D and accounts for the finite energy resolution of PET detectors; it is restricted to single scatter. The proposed energy-based simultaneous maximum likelihood reconstruction of activity and attenuation with photopeak scatter re-estimation algorithm is compared with simultaneous estimation from a single energy window simultaneous maximum likelihood reconstruction of activity and attenuation with photopeak scatter re-estimation. The evaluation is based on simulations using the characteristics of the Siemens mMR scanner. Phantoms of different complexity were investigated. In particular, a 3-D XCAT torso phantom was used to assess the inpainting of attenuation values within the lung region. Results show that the cross-talk present in non-TOF maximum likelihood reconstruction of activity and attenuation reconstructions is significantly reduced when using multiple energy windows and indicate that the proposed approach warrants further investigation.