Department of Biomedical Engineering, University of California, Davis, CA 95616, USA.
Phys Med Biol. 2011 Sep 7;56(17):N165-74. doi: 10.1088/0031-9155/56/17/N01. Epub 2011 Aug 9.
We have proposed a zoom-in positron emission tomography (PET) system that incorporates a high-resolution detector into an existing PET scanner to obtain high-resolution images of a region of interest. Previously we have shown by computer simulations that the high-resolution detector can improve the overall system performance in terms of spatial resolution and lesion detectability. In this study, we assessed the resolution improvement in a real system by incorporating a high-resolution detector into our existing microPET II scanner. The high-resolution detector consists of a 14 × 28 array of 0.5 × 0.5 × 10 mm³ lutetium oxyorthosilicate scintillator elements and is placed near the center of the microPET II scanner. It is coupled to two 64-channel photomultiplier tubes (PMTs) via tapered optical fiber bundles. The PMT signals were read out by the electronics in the microPET II scanner. A 15 µCi Na-22 point source was positioned at various locations above the high-resolution detector. Images were reconstructed using the data measured by the microPET II scanner alone and the microPET II data combined with the high-resolution detector data. Profiles taken through the reconstructed point sources show substantial reduction in full-width-at-half-maximum along the direction parallel to the face of the high-resolution detector.
我们提出了一种内插式正电子发射断层扫描（PET）系统，该系统将高分辨率探测器整合到现有的 PET 扫描仪中，以获取感兴趣区域的高分辨率图像。此前，我们通过计算机模拟表明，高分辨率探测器可以提高整体系统性能，提高空间分辨率和病变检测能力。在这项研究中，我们通过将高分辨率探测器整合到现有的 microPET II 扫描仪中，评估了实际系统中的分辨率提高。高分辨率探测器由一个 14×28 的 0.5×0.5×10mm³硅酸镥闪烁体元素阵列组成，放置在 microPET II 扫描仪的中心附近。它通过锥形光纤束与两个 64 通道光电倍增管（PMT）耦合。PMT 信号由 microPET II 扫描仪中的电子设备读出。一个 15µCi 的 Na-22 点源被放置在高分辨率探测器上方的不同位置。使用仅由 microPET II 扫描仪测量的数据以及 microPET II 数据与高分辨率探测器数据相结合来重建图像。通过重建点源获取的剖面图显示，沿与高分辨率探测器表面平行的方向，全宽半最大值有大幅减小。
