Time-Delay Correction Method for PET-Based Tumor Tracking
Time-Delay Correction Method for PET-Based Tumor Tracking
复制标题
基于 PET 的肿瘤追踪的时延校正方法
DOI：
10.1109/tns.2014.2364047
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发表时间：
2014
影响因子：
1.8
通讯作者：
Hideaki Haneishi
中科院分区：
文献类型：
--
作者：
Tetsuya Shinaji;Hideaki Tashima;Eiji Yoshida;Taiga Yamaya;Takashi Ohnishi;Hideaki Haneishi
日本国立放射线科学研究所正在开发世界上第一台开放式正电子发射断层扫描 (PET)，名为 OpenPET。我们的目标是在放射治疗中使用 OpenPET 并跟踪患者胸腹部肿瘤的呼吸运动。通过使用 PET 图像，我们期望肿瘤本身可以直接可视化，而无需使用不透射线标记物。我们使用小型原型 OpenPET 系统的演示结果表明，该系统可以以每秒约两帧的速度输出重建图像，并有约 2 秒的延迟；这种延迟主要是由于重建计算时间造成的。在本文中，我们开发了一种用于 OpenPET 肿瘤跟踪的时滞校正方法。由于仅使用2秒前的肿瘤位置很难校正时间延迟，因此我们假设引入另一个高速传感器来获取呼吸相位进行校正。在所提出的方法中，通过支持向量回归来计算肿瘤运动和附加传感器输出信号之间的关系，并使用获得的回归线来校正时间延迟。我们用计算机生成的 PET 图像模拟了这种时间延迟校正方法，这些图像具有从临床磁共振成像获得的实际呼吸运动。因此，当我们假设使用带式呼吸运动传感器时，我们可以以 1.20 ± 0.91 mm 的平均误差跟踪肿瘤。
The world's first open-type positron emission tomography (PET), named OpenPET, is being developed at the National Institute of Radiological Sciences, Japan. We are aiming to employ the OpenPET in radiotherapy and to track the respiratory motion of a tumor in the thoracoabdominal region of a patient. By using PET images, we expect that the tumor itself can be directly visualized without using radio-opaque markers. Our demonstration results using a small prototype OpenPET system showed that the system can output reconstructed images at about two frames per second with about a 2-s delay; this delay is mainly due to the reconstruction calculation time. In this paper, we developed a time-delay correction method for tumor tracking for the OpenPET. Since it is difficult to correct the time delay using only the tumor location at 2 s before, we assumed the introduction of another high-speed sensor to acquire the respiration phase for correction. In the proposed method, the relationship between the tumor motion and the additional sensor output signal is calculated by support vector regression and the time delay is corrected by using the obtained regression line. We simulated this time-delay correction method with computer-generated PET images which had actual respiration motions obtained from clinical magnetic resonance imaging. As a result, we could track the tumor with 1.20 ± 0.91 mm mean error when we assumed the use of a belt-type respiratory motion sensor.