First experimental results of time-of-flight reconstruction on an LSO PET scanner
First experimental results of time-of-flight reconstruction on an LSO PET scanner
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DOI：
10.1088/0031-9155/50/19/006
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发表时间：
2005-10-07
影响因子：
3.5
通讯作者：
Panin, V
中科院分区：
文献类型：
--
作者：
Conti, M;Bendriem, B;Panin, V
飞行时间（TOF）正电子发射断层扫描（PET）在20世纪80年代被研究和初步开发，但是缺乏能够同时提供适当的时间分辨率和阻止能力的闪烁体阻止了该技术的广泛应用和商业化。随着LSO在PET中的引入，TOF现在是一种可行的选择。TOF重建已在CPS Hi-Rez PET扫描仪中实现，包括2D滤波反投影（FBP 2D）和3D有序子集期望最大化（OSEM 3D）。在时间校准中引入了一种新的方法，以补偿现有电子学有限的数字时间分辨率。一个初步的版本的散射校正飞行时间已经设计和提出。测量的时间分辨率为1.2 ns（FWHM），允许约40厘米的横轴尺寸的幻影的信噪比增加约50%，或增益大于2的噪声等效计数（NEC）。TOF重建在仿真和实验数据中均显示出预期的SNR改善。第一个实验结果表明，TOF重建比传统的（非TOF）重建有两个改进：更低的噪声水平和更好的能力，以解决大物体内部的结构。
Time-of-flight (TOF) positron emission tomography (PET) was studied and preliminarily developed in the 1980s, but the lack of a scintillator able to deliver at the same time proper time resolution and stopping power has prevented this technique from becoming widespread and commercially available. With the introduction of LSO in PET, TOF is now a feasible option. TOF reconstruction has been implemented in the CPS Hi-Rez PET scanner, both with 2D filtered-back-projection (FBP2D) and 3D ordered subset expectation maximization (OSEM3D). A new procedure has been introduced in the time alignment to compensate for the limited digital time resolution of the present electronics. A preliminary version of scatter correction for TOF has been devised and is presented. The measured time resolution of 1.2 ns (FWHM) allowed for a signal-to-noise ratio increase of about 50% in phantoms of about 40 cm transaxial size, or a gain larger than 2 in noise equivalent counts (NEC). TOF reconstruction has shown the expected improvement in SNR, both in simulation and experimental data. First experimental results show two improvements of TOF reconstruction over conventional (non-TOF) reconstruction: a lower noise level and a better capability to resolve structures deep inside large objects.