标题： 正电子素寿命成像使用Biograph Vision Quadra进行124I成像 显示英文标题

标题： Positronium Lifetime Imaging with the Biograph Vision Quadra using 124I

摘要： 目的：在人体组织中测量正电子素（oPs）的寿命有可能为传统的正电子发射断层扫描（PET）增加关于组织微环境的临床相关信息。 通过幻影测量，我们研究使用商业长轴视野（LAFOV）PET扫描仪进行体素级oPs寿命测量。 方法：我们制备了四种样品，这些样品由Amberlite XAD4（一种多孔聚合吸附剂）和水的混合物组成，并加入了1.12 MBq到1.44 MBq的$^{124}$I。 这些样品以两种不同的设置进行扫描：一次是每个样品之间有几厘米的距离（15分钟扫描时间），另一次是所有样品粘在一起（40分钟扫描时间）。 对于每次扫描，我们确定整个样品和体素级别的oPs寿命。 考虑的体素尺寸为$10.0^3$ mm$^3$，$7.1^3$ mm$^3$ 和$4.0^3$ mm$^3$。 结果： Amberlite XAD4允许制备具有不同oPs寿命的样品。 使用贝叶斯拟合过程，整个样本中的oPs寿命分别为$2.52 \pm 0.03$ns，$2.37\pm 0.03$ns，$2.27\pm0.04$ns和$1.82\pm 0.02$ns。 体素级的oPs寿命拟合显示，即使使用$4.0^3$mm$^3$体素，样本仍然可以明显区分，中心体素具有良好的计数统计。 然而，对于紧密相邻的样本，由于不同oPs寿命区域的空间区分仍然具有挑战性。 结论：我们的研究表明，在临床条件下使用$^{124}$I，商业LAFOV PET/CT上的正电子寿命成像应该是可行的。 显示英文摘要

摘要： Purpose: Measuring the ortho-positronium (oPs) lifetime in human tissue bears the potential of adding clinically relevant information about the tissue microenvironment to conventional positron emission tomography (PET). Through phantom measurements, we investigate the voxel-wise measurement of oPs lifetime using a commercial long-axial field-of-view (LAFOV) PET scanner. Methods: We prepared four samples with mixtures of Amberlite XAD4, a porous polymeric adsorbent, and water and added between 1.12 MBq and 1.44 MBq of $^{124}$I. The samples were scanned in two different setups: once with a couple of centimeters between each sample (15 minutes scan time) and once with all samples taped together (40 minutes scan time). For each scan, we determine the oPs lifetime for the full samples and at the voxel level. The voxel sizes under consideration are $10.0^3$ mm$^3$, $7.1^3$ mm$^3$ and $4.0^3$ mm$^3$. Results: Amberlite XAD4 allows the preparation of samples with distinct oPs lifetime. Using a Bayesian fitting procedure, the oPs lifetimes in the whole samples are $2.52 \pm 0.03$ ns, $2.37\pm 0.03$ ns, $2.27\pm0.04$ ns and $1.82\pm 0.02$ ns, respectively. The voxel-wise oPs lifetime fits showed that even with $4.0^3$ mm$^3$ voxels the samples are clearly distinguishable and a central voxels have good count statistics. However, the situation with the samples close together remains challenging with respect to the spatial distinction of regions with different oPs lifetimes. Conclusion: Our study shows that positronium lifetime imaging on a commercial LAFOV PET/CT should be feasible under clinical conditions using $^{124}$I.