Basic research on a 3D CT system using a CCD sensor for Oral Maxillofacial region

为了研究使用针孔CCD传感器开发三维CT系统的问题，开发了1)模拟程序，2)重建程序，3)四步进电机控制系统和4)CCD控制系统。利用模拟程序(1)获得了数值二维投影数据。使用重建程序(2)计算数据的重建图像。这些结果为评估模拟程序和重建程序的合理性提供了可能。四个步进电机(3)的控制系统使控制最多4轴运动成为可能。通过开发CCD控制系统，可以获得直射图像。使用所有这些开发的程序和系统，可以毫无问题地获得中心位于CCD传感器获得的图像上方的断层图像。然而，还有一个问题有待解决。由于X射线光子的不足，使得利用针孔CCD传感器获得投影变得困难。我们必须在未来改善这个问题。

To investigate problems for developing a 3D CT system using a pinhole CCD sensor, 1) a simulation p program, 2) a reconstruction program, 3) a control system for four stepping motor and 4) a CCD control system were developed. By using the simulation program (1), numerical 2D projection data were obtained. The reconstruction images for the data were calculated by using the reconstruction program (2). These results made it possible to evaluate the propriety of the simulation program and the reconstruction program. The control system for four stepping motor (3) made it possible to control up to 4-axis moving. By developing the CCD control system, we could obtain direct projection images. Using all these developed programs and systems, tomographic images, the center of which was above the images obtained by a CCD sensor, could be obtained without problems. However, there is a problem to be left. The insufficient of the x-ray photons made it difficult to obtain the projection using a pinhole CCD sensor. We have to improve this problem in the future.