基于X射线像增强器成像的相衬滤波模型

对铝、黄铜、不锈钢3种金属材料制作的光栅在不同射线剂量和厚度差异的条件下进行图像采集,结合系统级的联合调制评价模型研究不同材料对X射线的调制作用,结果表明:在相同的射线剂量下,无论哪种材料的光栅,厚度差异越大成像反差越大;在厚度差异相同的情况下,随着射线剂量变化,不同材料对射线的调制能力变化趋势相差甚远。对光学调制传递函数、射线剂量和光栅厚度差异值进行三维曲线拟合,建立物质对X射线的调制模型和采集模型。在像增强器成像模型的基础上提出X射线相衬增强滤波模型,通过对薄膜基准目标源进行图像采集,在噪声环境下对其进行积分滤波处理和相衬增强处理,结果压低了图像噪声的同时也强化了目标轮廓信息,并大幅地增强X射线的成像反差。

Phase Contrast Filtering Model Based on X-ray Image Intensifier Imaging

The image acquisitions for the gratings made of aluminum, brass and stainless steel under different conditions of doses and thicknesses were carried out, combined with the system-level joint modulation evaluation model, the modulation effects of different materials on X-ray were studied, under the same radiation dose, no matter which kind of material was used, the difference in thickness is larger the imaging contrast is larger, in the case of the same thickness difference, the variation of the modulation ability of different materials with the radiation varies greatly with the change of the radiation dose. Three-dimensional curve fitting of optical modulation transfer function, X-ray dose and grating thickness difference was established, and the modulation model and acquisition model of the material on X-ray were established. A X-ray phase-contrast enhancement filtering model was proposed based on the image intensifier imaging model, in the noise environment, the integration filtering and phase contrast enhancement processing were performed, the image noise was suppressed while the target contour information was strengthened, and the contrast of X-ray images was greatly enhanced.