在医用X-CT中,散射现象对重建图像的质量有重要的影响。多源锥束CT是医用CT的一种发展趋势,可成倍提高时间分辨率。但与单源CT相比,多源CT额外的光源会导致散射现象的加重,因此在实际应用中需要着重考虑这一问题。本文在开源工具EGSnrc的基础上,开发了一套基于蒙特卡罗法的CT仿真软件SimProj,用该软件获得了贴近实际的三源锥束CT投影数据。重建图像显示出了预期的散射伪影,结果分析对优化三源CT的设计和制造有重要的指导意义。 In medical X-CT, the scattering phenomenon has a significant impact on the quality of the reconstructed image. Multi-source cone beam CT is a trend of medical CT, which can double the time resolution. However, compared with single-source CT, additional sources of multi-source CT will lead to the proliferation of scattering, so in practical applications need to focus on this issue. In this paper, based on the open source tool EGSnrc, a set of Monte Carlo CT simulation software SimProj is developed, which is close to the actual three-source cone beam CT projection data. Reconstruction of the image shows the expected scattering artifacts, the results of the analysis of the design and manufacture of three-source CT has important guiding significance.