A tetrahedron beam computed tomography benchtop system with a multiple pixel field emission x-ray tube
A tetrahedron beam computed tomography benchtop system with a multiple pixel field emission x-ray tube
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DOI：
10.1118/1.3634043
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发表时间：
2011-10-01
期刊：
影响因子：
3.8
通讯作者：
Zhang, Tiezhi
中科院分区：
文献类型：
--
作者：
Xu, Xiaochao;Kim, Joshua;Zhang, Tiezhi
目的：为了证明四面体射束计算机断层扫描（TBCT）的可行性，使用碳纳米管（CNT）多像素场发射X射线（MPFEX）tube.Methods：多像素X射线源有利于创建新的X射线成像模式。在先前的出版物中，作者提出了一种四面体波束计算机断层扫描（TBCT）成像系统，其包括彼此正交的线性源阵列和线性检测器阵列。与锥形束计算机断层扫描（CBCT）相比，TBCT有望减少散射，并具有更好的探测器性能。因此，它可以为图像引导的放射治疗产生改善的图像质量。在这项研究中，TBCT台式系统已开发与MPFEX管。该管具有75个CNT冷阴极，其在细长阳极上产生75个X射线焦斑，并且具有4 mm像素间距。一个内部开发的，5行CT检测器阵列，使用硅光电二极管和CdWO 4的闪烁器中采用的系统。开发了用于管控制和探测器数据采集的硬件和软件。对原始数据进行预处理，以获得射束硬化和探测器响应线性，并使用基于FDK的图像重建算法进行重建。结果：使用星星体模测量焦斑，焦斑约为1 x 2 mm（2）。每个阴极在2190 V栅极电压下产生约3 mA阴极电流。台式系统能够以延长的扫描时间执行TBCT扫描。结论：开发了一个原型系统，并成功地获得了初步的体模图像。MPFEX是一种很有前途的TBCT X射线源。为了使其用于临床TBCT系统，需要进一步改进管输出。(C)2011年美国医学物理学家协会。[DOI 10.1118/1.3634043]
Purpose: To demonstrate the feasibility of Tetrahedron Beam Computed Tomography (TBCT) using a carbon nanotube (CNT) multiple pixel field emission x-ray (MPFEX) tube.Methods: A multiple pixel x-ray source facilitates the creation of novel x-ray imaging modalities. In a previous publication, the authors proposed a Tetrahedron Beam Computed Tomography (TBCT) imaging system which comprises a linear source array and a linear detector array that are orthogonal to each other. TBCT is expected to reduce scatter compared with Cone Beam Computed Tomography (CBCT) and to have better detector performance. Therefore, it may produce improved image quality for image guided radiotherapy. In this study, a TBCT benchtop system has been developed with an MPFEX tube. The tube has 75 CNT cold cathodes, which generate 75 x-ray focal spots on an elongated anode, and has 4 mm pixel spacing. An in-house-developed, 5-row CT detector array using silicon photodiodes and CdWO4 scintillators was employed in the system. Hardware and software were developed for tube control and detector data acquisition. The raw data were preprocessed for beam hardening and detector response linearity and were reconstructed with an FDK-based image reconstruction algorithm.Results: The focal spots were measured at about 1 x 2 mm(2) using a star phantom. Each cathode generates around 3 mA cathode current with 2190 V gate voltage. The benchtop system is able to perform TBCT scans with a prolonged scanning time. Images of a commercial CT phantom were successfully acquired.Conclusions: A prototype system was developed, and preliminary phantom images were successfully acquired. MPFEX is a promising x-ray source for TBCT. Further improvement of tube output is needed in order for it to be used in clinical TBCT systems. (C) 2011 American Association of Physicists in Medicine. [DOI: 10.1118/1.3634043]