64-channel photon-counting computed tomography using a new MPPC-CT system
64-channel photon-counting computed tomography using a new MPPC-CT system
复制标题
使用新型 MPPC-CT 系统的 64 通道光子计数计算机断层扫描
DOI：
10.1016/j.nima.2020.164610
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发表时间：
2020
期刊：
影响因子：
--
通讯作者：
Ikeda H.
中科院分区：
文献类型：
--
作者：
Kiji H.;Maruhashi T.;Toyoda T.;Kataoka J.;Arimoto M.;Sato D.;Yoshiura K.;Kobayashi S.;Kawashima H.;Terazawa S.;Shiota S.;Ikeda H.
X 射线计算机断层扫描 (CT) 是一种广泛使用的诊断工具，用于可视化人体内部。然而，常规CT单次扫描的受照剂量较大，一般为10毫西弗，因此有必要寻找降低辐射剂量的方法。此外，传统 CT 不包含单个 X 射线光子的能量信息，因为 X 射线信号是以积分形式读出的。这会导致材料的错误识别。为了解决这个问题，我们提出了一种新型光子计数 CT (PC-CT) 系统，由多像素光子计数器 (MPPC) 和高速闪烁体组成。该系统具有 64 通道 MPPC 阵列，可改善能量信息和广域成像。通过在64通道PC-CT系统中新实现的精细能量调整并将能量阈值数量增加到6个，我们成功地准确估计了碘和钆等造影剂的浓度。此外，对于碘和钆的混合模型，我们证明了它们之间的区别，并单独估计了浓度，这是传统 CT 无法做到的。这显示出扩大X射线CT应用的巨大潜力。
X-ray computed tomography (CT) is a widely used diagnostic tool to visualize the interior of the human body. However, the exposure dose of conventional CT in a single scan is large, typically 10 mSv, and therefore, it is necessary to find ways to reduce the radiation dose. Furthermore, conventional CT does not contain the energy information of individual X-ray photons because the X-ray signals are read out as an integrated form. This causes misidentification of materials. To resolve this issue, we propose a novel photon counting CT (PC-CT) system consisting of multi-pixel photon counters (MPPCs) coupled with high speed scintillators. The system has a 64-channel MPPC array that improves energy information and wide-area imaging. By fine energy adjustment and increasing the number of energy thresholds to six, which were newly implemented in the 64-channel PC-CT system, we succeeded in accurately estimating the concentrations of contrast agents such as iodine and gadolinium. Moreover, for mixed phantoms of iodine and gadolinium, we demonstrate discrimination between them, and estimate the concentrations individually, which cannot be done by conventional CTs. This shows great potential in expanding the applications of X-ray CTs.