Department of Biomedical Sciences, Seoul National University College of Medicine, Seoul, 03080, Korea.
Department of Nuclear Medicine, Seoul National University College of Medicine, Seoul, 03080, Korea.
Med Phys. 2017 Oct;44(10):5314-5324. doi: 10.1002/mp.12440. Epub 2017 Aug 18.
Time-of-flight (TOF) information in positron emission tomography (PET) scanners enhances the diagnostic power of PET scans owing to the increased signal-to-noise ratio of reconstructed images. There are numerous additional benefits of TOF reconstruction, including the simultaneous estimation of activity and attenuation distributions from emission data only. Exploring further TOF gains by using TOF PET scanners is important because it can broaden the applications of PET scans and expand our understanding of TOF techniques. Herein, we present a prototype TOF PET scanner with fine-time performance that can experimentally demonstrate the benefits of TOF information.
A single-ring PET system with a coincidence resolving time of 360 ps and a spatial resolution of 3.1/2.2 mm (filtered backprojection/ordered-subset expectation maximization) was developed. The scanner was based on advanced high-quantum-efficiency (high-QE) multianode photomultiplier tubes (PMTs). The impact of its fine-time performance was demonstrated by evaluating body phantom images reconstructed with and without TOF information. Moreover, the feasibility of the scanner as an experimental validator of TOF gains was verified by investigating the improvement of images under various conditions, such as the use of joint estimation algorithms of activity and attenuation, erroneous data correction factors (e.g., without normalization correction), and incompletely sampled data.
The prototype scanner showed excellent performance, producing improved phantom images, when TOF information was employed in the reconstruction process. In addition, investigation of the TOF benefits using the phantom data in different conditions verified the usefulness of the developed system for demonstrating the practical effects of TOF reconstruction.
We developed a prototype TOF PET scanner with good performance and a fine-timing resolution based on advanced high-QE multianode PMTs and demonstrated its feasibility as an experimental validator of TOF gains, suggesting its usefulness for investigating new applications of PET scans and clarifying TOF techniques in detail.
正电子发射断层扫描（PET）扫描仪中的飞行时间（TOF）信息由于重建图像的信噪比提高，增强了 PET 扫描的诊断能力。TOF 重建还有许多其他额外的好处，包括仅从发射数据同时估计活动和衰减分布。探索使用 TOF PET 扫描仪进一步获得 TOF 增益很重要，因为这可以拓宽 PET 扫描的应用范围，并扩展我们对 TOF 技术的理解。本文介绍了一款具有精细时间性能的 TOF PET 扫描仪原型，可通过实验演示 TOF 信息的优势。
开发了一种具有 360 ps 符合分辨时间和 3.1/2.2mm（滤波后向投影/有序子集期望最大化）空间分辨率的单环 PET 系统。该扫描仪基于先进的高量子效率（高 QE）多阳极光电倍增管（PMT）。通过评估具有和不具有 TOF 信息的体模图像重建，展示了其精细时间性能的影响。此外，通过研究在各种条件下，例如使用活动和衰减的联合估计算法、错误数据校正因子（例如，没有归一化校正）和不完全采样数据，验证了该扫描仪作为 TOF 增益的实验验证器的可行性。
当在重建过程中使用 TOF 信息时，原型扫描仪显示出出色的性能，产生了改进的图像。此外，使用不同条件下的体模数据研究 TOF 收益验证了所开发系统用于演示 TOF 重建实际效果的有用性。
我们基于先进的高 QE 多阳极 PMT 开发了一款具有良好性能和精细定时分辨率的 TOF PET 扫描仪，并验证了其作为 TOF 增益实验验证器的可行性，表明其在研究 PET 扫描的新应用和详细阐明 TOF 技术方面的有用性。
