Evaluation of a BGO-Based PET System for Single-Cell Tracking Performance by Simulation and Phantom Studies.
Evaluation of a BGO-Based PET System for Single-Cell Tracking Performance by Simulation and Phantom Studies.
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DOI：
10.1177/1536012116646489
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发表时间：
2016
影响因子：
2.8
通讯作者：
Pratx G
中科院分区：
文献类型：
--
作者：
Ouyang Y;Kim TJ;Pratx G
最近报道了一种基于正电子发射的方法，用于使用Inveon PET系统跟踪移动点源。然而，扫描仪背景噪声的影响并没有得到进一步的研究。在这里，我们使用Genisys4（一种基于锗酸铋的PET系统）来评估跟踪，该系统没有显著的内在背景，可能更适合于跟踪较低和/或更快的活性源。在Geant4应用于层析发射（GATE）中，使用静态18F点源模拟Genisys4的位置依赖灵敏度。根据前文所述的列表模式数据重建具有不同活度和转速的螺旋运动点源的轨迹。模拟表明，Inveon的定位误差在2毫米以内的能力仅限于速度与活动比< 0.13 mm/衰减的物体，而Genisys4的速度与活动比< 0.29 mm/衰减。然后使用螺旋运动[18F]氟脱氧葡萄糖油滴（直径< 0.24 mm, 139-296 Bq）的物理幻影验证Genisys4的跟踪，在测试条件下产生< 1 mm的定位误差，模拟灵敏度与测量活度之间具有良好的一致性（Pearson相关R = 0.64，代表性示例中P << 0.05）。我们对Genisys4的跟踪性能进行了研究，结果表明该系统可以跟踪低活动的点源类目标。
A recent method based on positron emission was reported for tracking moving point sources using the Inveon PET system. However, the effect of scanner background noise was not further explored. Here, we evaluate tracking with the Genisys4, a bismuth germanate-based PET system, which has no significant intrinsic background and may be better suited to tracking lower and/or faster activity sources. Position-dependent sensitivity of the Genisys4 was simulated in Geant4 Application for Tomographic Emission (GATE) using a static 18F point source. Trajectories of helically moving point sources with varying activity and rotation speed were reconstructed from list-mode data as described previously. Simulations showed that the Inveon’s ability to track sources within 2 mm of localization error is limited to objects with a velocity-to-activity ratio < 0.13 mm/decay, compared to < 0.29 mm/decay for the Genisys4. Tracking with the Genisys4 was then validated using a physical phantom of helically moving [18F] fluorodeoxyglucose-in-oil droplets (< 0.24 mm diameter, 139-296 Bq), yielding < 1 mm localization error under the tested conditions, with good agreement between simulated sensitivity and measured activity (Pearson correlation R = .64, P << .05 in a representative example). We have investigated the tracking performance with the Genisys4, and results suggest the feasibility of tracking low activity, point source-like objects with this system.