X射线衍射增强成像中DEI峰位CT图像的解释

CT Image Explanation in Peak Diffraction-Enhanced Imaging

在衍射增强成像中,其峰位CT成像模式中的消光衬度产生使物体的CT图像边界增强的效果,从而有效地提高了断层图像的空间分辨能力。本文提出了这种由于消光衬度引起的DEI-CT图像增强的额外灰度变化的一个确定的物理解释,并通过理论模拟计算与简单圆物体实验数据的处理,证明了这种边缘增强效果具有单像素宽、高密度圆形物体的成像特征,有助于解读峰位DEI-CT图像。

In X-ray Diffraction Enhanced Imaging （DEI）, the extinction contrast in peak CT mode can intensify the boundary of the object, and effectively raise the special resolution of the tomographic image. In this article, a definite physical explanation is given to this intensifying effect. By theoretic calculating and BSRF experimental data processing, it is demonstrated that this extinction contrast leads in CT image a fictitious one-pixel wide round ring with a very high mass density, and thus intensifies the image of edges of the round object.