Feasibility Study of a Small Animal PET Insert Based on a Single LYSO Monolithic Tube
Feasibility Study of a Small Animal PET Insert Based on a Single LYSO Monolithic Tube
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DOI：
10.3389/fmed.2018.00328
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发表时间：
2018-11-28
影响因子：
3.9
通讯作者：
Benlloch, Jose M.
中科院分区：
文献类型：
--
作者：
Gonzalez, Antonio J.;Berr, Stuart S.;Benlloch, Jose M.
正电子发射断层扫描（PET）扫描仪设计采用传统的多探测器排列阵列格式，存在缺点。典型的PET系统在环形或箱形结构的检测器模块之间有许多规则的间隙，环形之间有额外的轴向间隙。尽管使用紧凑的高粒度SiPM光电探测器技术大大减少了这种情况，但这种扫描仪的设计导致被检测到的湮灭光子数量减少，从而降低了扫描仪的灵敏度。此外，精确确定正电子湮灭的响应线（LOR）的能力在靠近探测器边缘的地方减弱，因为那里的空间分辨率由于边缘效应而降低。这种情况既发生在基于单片的设计中，由闪烁光分布的截断引起，也发生在使用晶体阵列的探测器块中，这些晶体阵列的元素数量大于光传感器的数量，因此利用了光共享原理。在本报告中，我们提出了一种基于单个单片环形闪烁体的小动物PET扫描仪的设计，该闪烁体可作为高场磁共振系统中的PET插入物。我们提供了实际数据，显示使用无边缘模块时性能的改善。我们还描述了一种啮齿类动物扫描仪的具体建议设计，该扫描仪在单个LYSO管中采用了外部面。在进一步的步骤中，为了支持和证明所提出的无边缘几何，对该扫描仪进行了模拟，并在最近重建了该设计的优点。
There are drawbacks with using a Positron Emission Tomography (PET) scanner design employing the traditional arrangement of multiple detectors in an array format. Typically PET systems are constructed with many regular gaps between the detector modules in a ring or box configuration, with additional axial gaps between the rings. Although this has been significantly reduced with the use of the compact high granularity SiPM photodetector technology, such a scanner design leads to a decrease in the number of annihilation photons that are detected causing lower scanner sensitivity. Moreover, the ability to precisely determine the line of response (LOR) along which the positron annihilated is diminished closer to the detector edges because the spatial resolution there is degraded due to edge effects. This happens for both monolithic based designs, caused by the truncation of the scintillation light distribution, but also for detector blocks that use crystal arrays with a number of elements that are larger than the number of photosensors and, therefore, make use of the light sharing principle. In this report we present a design for a small-animal PET scanner based on a single monolithic annulus-like scintillator that can be used as a PET insert in high-field Magnetic Resonance systems. We provide real data showing the performance improvement when edge-less modules are used. We also describe the specific proposed design for a rodent scanner that employs facetted outside faces in a single LYSO tube. In a further step, in order to support and prove the proposed edgeless geometry, simulations of that scanner have been performed and lately reconstructed showing the advantages of the design.