Dual source and dual detector arrays tetrahedron beam computed tomography for image guided radiotherapy
Dual source and dual detector arrays tetrahedron beam computed tomography for image guided radiotherapy
复制标题
DOI：
10.1088/0031-9155/59/3/615
复制
发表时间：
2014-02-07
影响因子：
3.5
通讯作者：
Zhang, Tiezhi
中科院分区：
文献类型：
--
作者：
Kim, Joshua;Lu, Weiguo;Zhang, Tiezhi
锥形束计算机断层扫描（CBCT）是图像引导放射治疗的重要在线成像方式。但是次优的图像质量和缺乏实时立体成像功能限制了其在先进治疗技术中的实施，例如在线自适应和4D放射治疗。四面体束计算机断层扫描（TBCT）是一种新型的在线成像模式，旨在提高CBCT提供的图像质量。TBCT几何形状灵活，多个探测器和源阵列可用于不同的应用。在本文中，我们描述了一种新的双源双探测器TBCT系统，是专门设计的直线加速器辐射治疗机。成像系统与MV射束成一直线，由安装在电子射野成像装置旁边的两个线性阵列X射线源和安装在机器头部下方的两个线性阵列X射线探测器组成。检测器和X射线源阵列彼此正交，并且每对源和检测器阵列形成四面体体积。四个平面图像可以从不同的视角在每个机架位置，以高达每秒20帧的帧速率获得。重叠区域提供大约10-15 cm的立体视场。通过半个机架旋转，可以重建具有45 cm视场的体积CT图像。由于TBCT几何结构的散射抑制设计，该系统可以潜在地产生具有较少辐射暴露的高质量2D和3D图像。双源双探测器系统的设计进行了说明，并进行数值幻影和模拟患者数据的研究的初步结果。
Cone-beam computed tomography (CBCT) is an important online imaging modality for image guided radiotherapy. But suboptimal image quality and the lack of a real-time stereoscopic imaging function limit its implementation in advanced treatment techniques, such as online adaptive and 4D radiotherapy. Tetrahedron beam computed tomography (TBCT) is a novel online imaging modality designed to improve on the image quality provided by CBCT. TBCT geometry is flexible, and multiple detector and source arrays can be used for different applications. In this paper, we describe a novel dual source-dual detector TBCT system that is specially designed for LINAC radiation treatment machines. The imaging system is positioned in-line with the MV beam and is composed of two linear array x-ray sources mounted aside the electrical portal imaging device and two linear arrays of x-ray detectors mounted below the machine head. The detector and x-ray source arrays are orthogonal to each other, and each pair of source and detector arrays forms a tetrahedral volume. Four planer images can be obtained from different view angles at each gantry position at a frame rate as high as 20 frames per second. The overlapped regions provide a stereoscopic field of view of approximately 10-15 cm. With a half gantry rotation, a volumetric CT image can be reconstructed having a 45 cm field of view. Due to the scatter rejecting design of the TBCT geometry, the system can potentially produce high quality 2D and 3D images with less radiation exposure. The design of the dual source-dual detector system is described, and preliminary results of studies performed on numerical phantoms and simulated patient data are presented.