Simulation study comparing the helmet-chin PET with a cylindrical PET of the same number of detectors
Simulation study comparing the helmet-chin PET with a cylindrical PET of the same number of detectors
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DOI：
10.1088/1361-6560/aa685c
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发表时间：
2017-06-07
影响因子：
3.5
通讯作者：
Yamaya, Taiga
中科院分区：
文献类型：
--
作者：
Ahmed, Abdella M.;Tashima, Hideaki;Yamaya, Taiga
开发具有高灵敏度和高空间分辨率的脑PET扫描仪用于神经退行性疾病的早期诊断和脑功能研究的兴趣越来越大。PET扫描仪的灵敏度可以通过增加立体角来提高。然而，传统的PET扫描仪是基于圆柱形几何结构设计的，就灵敏度和成本之间的平衡而言，这可能不是用于脑成像的最有效的设计。我们提出了一个专用的大脑PET扫描仪的基础上半球形状检测器和下巴检测器（称为头盔下巴PET），这是为了最大限度地提高立体角，通过增加半球的响应线的数量。视差误差，其中PET扫描仪具有大的立体角往往有，可以通过使用的深度的相互作用检测器抑制。在这项研究中，我们使用基于4层GSO探测器的Monte Carlo模拟对头盔下巴PET进行了现实评估，该探测器由尺寸为2.8 x 2.8 x 7.5 mm的16 x 16 x 4晶体阵列组成（3）。该模拟的目的是显示在每种配置中使用相同数量的探测器时，与圆柱形PET相比，头盔下巴PET的成像性能的增益。使用圆柱体模评估的头盔-下巴PET的灵敏度显著增加，尤其是在（视野）FOV的顶部。头盔下巴PET的峰值NECR是圆柱形PET的1.4倍。与圆柱形PET相比，头盔下巴PET在整个视野中提供相对较低的噪声图像，圆柱形PET在外围区域表现出增强的噪声。结果表明，头盔-下巴PET能显著提高重建图像的灵敏度，降低重建图像的噪声。
There is a growing interest in developing brain PET scanners with high sensitivity and high spatial resolution for early diagnosis of neurodegenerative diseases and studies of brain functions. Sensitivity of the PET scanner can be improved by increasing the solid angle. However, conventional PET scanners are designed based on a cylindrical geometry, which may not be the most efficient design for brain imaging in terms of the balance between sensitivity and cost. We proposed a dedicated brain PET scanner based on a hemispheric shape detector and a chin detector (referred to as the helmet-chin PET), which is designed to maximize the solid angle by increasing the number of lines-of- response in the hemisphere. The parallax error, which PET scanners with a large solid angle tend to have, can be suppressed by the use of depth-of-interaction detectors. In this study, we carry out a realistic evaluation of the helmet-chin PET using Monte Carlo simulation based on the 4-layer GSO detector which consists of a 16 x 16 x 4 array of crystals with dimensions of 2.8 x 2.8 x 7.5 mm(3). The purpose of this simulation is to show the gain in imaging performance of the helmet-chin PET compared with the cylindrical PET using the same number of detectors in each configuration. The sensitivity of the helmet-chin PET evaluated with a cylindrical phantom has a significant increase, especially at the top of the (field-of-view) FOV. The peak-NECR of the helmet-chin PET is 1.4 times higher compared to the cylindrical PET. The helmet-chin PET provides relatively low noise images throughout the FOV compared to the cylindrical PET which exhibits enhanced noise at the peripheral regions. The results show the helmet-chin PET can significantly improve the sensitivity and reduce the noise in the reconstructed images.