为了实现图像引导放疗与功能成像结合的功能图像引导放疗,研究运用图像引导放疗中的锥束CT影像设备进行CT灌注成像的可能性.为了解决锥束CT不能快速成像,进而不能获取准确的体素时间-密度曲线(IDC)的问题,提出了一种基于投影数据的体素密度建模方法.首先,运用计算机仿真技术模拟出锥束CT投影数据;然后,对各体素密度值进行数学建模;最后,利用计算机最优化值求解技术,编程实现模型具体参数的计算.实验证明,该模型得到的TDC和DCE-CT实测获得的TDC有很高的吻合度.该模型实现图像引导放疗中的锥束CT灌注成像是可行的.%In order to realize function imaging guided radiotherapy combined with image-guided radiotherapy and function imaging, this paper studied the possibility of Computed Tomography (CT) perfusion imaging using cone-beam CT on imageguided radiotherapy.To solve the problem that Cone-Beam Computed Tomography (CBCT) cannot obtain precise Time-Density Curve (TDC) because of low speed imaging, this paper proposed a method of modeling a mathematically model based on projection data.At first, the CBCT projection data was simulated with computer simulation technology.Then the density values of voxel were mathematical modeled.Finally, concrete parameters were calculated using computer programming and computer optimal solution technology.The experiment proves that the TDC received from the proposed model and the Dynamic Contrast Enhanced CT (DCE-CT) have high similarity.Hence, it can be proved that realizing CBCT in image-guided radiotherapy perfusion imaging by the proposed model was feasible.
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