A hardware investigation of robotic SPECT for functional and molecular imaging onboard radiation therapy systems.
A hardware investigation of robotic SPECT for functional and molecular imaging onboard radiation therapy systems.
复制标题
用于机载放射治疗系统功能和分子成像的机器人 SPECT 的硬件研究。
DOI：
10.1118/1.4898121
复制
发表时间：
2014
期刊：
影响因子：
3.8
通讯作者：
Yin,Fang-Fang
中科院分区：
文献类型：
--
作者：
Yan,Susu;Bowsher,James;Tough,MengHeng;Cheng,Lin;Yin,Fang-Fang
目的构建机器人 SPECT 系统并展示其在放射治疗平顶沙发上对胸部体模进行成像的能力，作为放射治疗中机载功能和分子成像的一步。方法利用伽马相机探测器 (Digirad 2020tc) 和机器人 (KUKA KR150 L110 机器人) 构建机器人 SPECT 成像系统。使用模型 (PET CT PhantomTM) 进行成像研究，该模型包括五个直径为 10、13、17、22 和 28 毫米的球体。模型被放置在平顶沙发上。 SPECT 投影是使用平行孔准直器或单针孔准直器获得的，两者在体模中都没有背景，并且背景为球体活动浓度的 1/10。平行孔和针孔准直探测器的成像轨迹分别跨越180°和228°。针孔探测器观察到一个偏心的球形公共体积，其中包含 28 毫米和 22 毫米的球体。平行孔系统的公共体积以体模为中心，包含体模中的所有五个球体。通过导航探测器追踪模型和平顶桌子，同时避免碰撞并保持尽可能接近公共体积，来测试机器人系统的可操作性。机器人底座和工具坐标用于图像重建。结果机器人 SPECT 系统能够操纵平行孔和针孔准直 SPECT 探测器靠近模型，最大限度地减少平顶沙发对探测器旋转半径的影响。在没有背景的情况下，所有五个球体在重建的平行孔图像中都是可见的，而四个球体（除了最小的球体之外）在重建的针孔图像中都是可见的。在背景下，通过平行孔成像很容易观察到直径为 17、22 和 28 毫米的三个球体，并且在针孔感兴趣区域成像中很容易观察到目标球体（直径为 22 和 28 毫米）。结论机载 SPECT 可以通过机器人操纵 SPECT 探测器来实现，患者位于平顶沙发上进行放射治疗。机器人固有坐标系可能是估计用于 SPECT 图像重建的探测器位姿的有效方法。
PurposeTo construct a robotic SPECT system and to demonstrate its capability to image a thorax phantom on a radiation therapy flat‐top couch, as a step toward onboard functional and molecular imaging in radiation therapy.MethodsA robotic SPECT imaging system was constructed utilizing a gamma camera detector (Digirad 2020tc) and a robot (KUKA KR150 L110 robot). An imaging study was performed with a phantom (PET CT PhantomTM), which includes five spheres of 10, 13, 17, 22, and 28 mm diameters. The phantom was placed on a flat‐top couch. SPECT projections were acquired either with a parallel‐hole collimator or a single‐pinhole collimator, both without background in the phantom and with background at 1/10th the sphere activity concentration. The imaging trajectories of parallel‐hole and pinhole collimated detectors spanned 180° and 228°, respectively. The pinhole detector viewed an off‐centered spherical common volume which encompassed the 28 and 22 mm spheres. The common volume for parallel‐hole system was centered at the phantom which encompassed all five spheres in the phantom. The maneuverability of the robotic system was tested by navigating the detector to trace the phantom and flat‐top table while avoiding collision and maintaining the closest possible proximity to the common volume. The robot base and tool coordinates were used for image reconstruction.ResultsThe robotic SPECT system was able to maneuver parallel‐hole and pinhole collimated SPECT detectors in close proximity to the phantom, minimizing impact of the flat‐top couch on detector radius of rotation. Without background, all five spheres were visible in the reconstructed parallel‐hole image, while four spheres, all except the smallest one, were visible in the reconstructed pinhole image. With background, three spheres of 17, 22, and 28 mm diameters were readily observed with the parallel‐hole imaging, and the targeted spheres (22 and 28 mm diameters) were readily observed in the pinhole region‐of‐interest imaging.ConclusionsOnboard SPECT could be achieved by a robot maneuvering a SPECT detector about patients in position for radiation therapy on a flat‐top couch. The robot inherent coordinate frames could be an effective means to estimate detector pose for use in SPECT image reconstruction.