Development of a prototype Open-close positron emission tomography system.
Development of a prototype Open-close positron emission tomography system.
复制标题
开发开闭式正电子发射断层扫描系统原型。
DOI：
10.1063/1.4929329
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发表时间：
2015
期刊：
影响因子：
--
通讯作者：
J. Hatazawa
中科院分区：
文献类型：
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作者：
S. Yamamoto;S. Okumura;T. Watabe;Hayato Ikeda;Y. Kanai;T. Toshito;M. Komori;Y. Ogata;Katsuhiko Kato;J. Hatazawa
我们开发了一个原型的正电子发射断层扫描（PET）系统的基础上的一个新的概念，称为开-关PET，它有两种模式：开放和关闭模式。在开放模式下，探测器环被分成两个半环，并且对象利用开放空间成像，并形成投影图像。在闭合模式中，检测器环闭合为规则的圆环，并且可以在没有开放空间的情况下对对象进行成像，因此可以在没有伪影的情况下进行重建图像。开-闭PET系统的块探测器由两个闪烁体块组成，这两个闪烁体块使用两种具有不同衰减时间的原硅酸钆（GSO）闪烁器、基于成角度光纤的图像导向器和平板光电倍增管。快速（35 ns）和慢速（60 ns）地球同步轨道的像素大小分别为1.6 × 2.4 × 7 mm和8 mm。这些地球静止轨道排列成11 × 15矩阵，并在深度方向上进行光学耦合，形成相互作用深度探测器。使用成角度的基于光纤的图像导向器以22.5°布置两个闪烁体块，使得它们可以布置成具有八个块探测器的六边形形状，以简化重建算法。探测器环被分成两半，以实现开放模式，并设置在一个机械支架上，可以手动改变两部分之间的距离。闭合模式下的空间分辨率为2.4 mm FWHM，视场中心的灵敏度为1.7%。在关闭和打开模式下，我们在两个半探测器环之间制作矢状（y-z平面）投影图像。我们获得了（18）F-NaF大鼠研究的重建和投影图像以及质子辐照的体模图像。这些结果表明，我们开发的开-闭PET是有用的一些应用，如质子治疗以及其他应用，如分子成像。
We developed a prototype positron emission tomography (PET) system based on a new concept called Open-close PET, which has two modes: open and close-modes. In the open-mode, the detector ring is separated into two halved rings and subject is imaged with the open space and projection image is formed. In the close-mode, the detector ring is closed to be a regular circular ring, and the subject can be imaged without an open space, and so reconstructed images can be made without artifacts. The block detector of the Open-close PET system consists of two scintillator blocks that use two types of gadolinium orthosilicate (GSO) scintillators with different decay times, angled optical fiber-based image guides, and a flat panel photomultiplier tube. The GSO pixel size was 1.6 × 2.4 × 7 mm and 8 mm for fast (35 ns) and slow (60 ns) GSOs, respectively. These GSOs were arranged into an 11 × 15 matrix and optically coupled in the depth direction to form a depth-of-interaction detector. The angled optical fiber-based image guides were used to arrange the two scintillator blocks at 22.5° so that they can be arranged in a hexadecagonal shape with eight block detectors to simplify the reconstruction algorithm. The detector ring was divided into two halves to realize the open-mode and set on a mechanical stand with which the distance between the two parts can be manually changed. The spatial resolution in the close-mode was 2.4-mm FWHM, and the sensitivity was 1.7% at the center of the field-of-view. In both the close- and open-modes, we made sagittal (y-z plane) projection images between the two halved detector rings. We obtained reconstructed and projection images of (18)F-NaF rat studies and proton-irradiated phantom images. These results indicate that our developed Open-close PET is useful for some applications such as proton therapy as well as other applications such as molecular imaging.