基于平板探测器的2D-CT成像技术的研究

大面积非晶硅平板探测器(flat panel detector-FPD)在透射射线成像领域得到越来越多的应用。基于FPD的圆轨道FDK型三维计算机层析成像技术(Computed Tomography,3D-CT)检测速度快,但成像质量不及2D-CT。为发挥3D-CT速度优势,同时提高系统对物体感兴趣区域CT成像的性能,研究了一种基于FPD的、配合3D-CT功能的高像质2D-CT成像技术;提出了一种集噪声抑制、散射校正和高频细节增强于一体的2D-CT投影预处理方法,并完成了基于FPD的2D/3D-CT集成原型系统的研制。系统性能测试结果表明,基于FPD的2D-CT技术成像空间分辨率达3lp/mm,密度分辨率达5‰。

Research on 2D-CT imaging technique based on flat panel detector

Large-area a-Si X-ray flat panel detector(FPD) is becoming more and more popular in the field of transmission radiation imaging. FDK-type three dimensional computed tomography(3D-CT) with circular orbit based on FPD can execute inspection rapidly, but its imaging quality can not reach that of 2D-CT. In order to make the best of the speed advantage of 3D-CT and improve the performance of the system to image the region-of-interest area,2D-CT based on FPD with high imaging quality was researched. The corresponding projection pre-procession method, including noise reduction, scatter correction and high-frequency detail intensification, was proposed. The 2D/3D-CT and DR integration system based on FPD was realized. The performance testing results of the system showed that the spatial resolution of this kind of technique reached 3lp/mm and the density resolution reached 5‰.