能量自适应的X射线DR/CT成像综述——谨以此文向我国CT成像领域的开创者之一邱佩璋先生致敬

Review of X-ray DR/CT imaging with energy self-adaption

复杂结构件在X射线三维CT成像时,由于射线透射方向上有效透照厚度差异大,探测器成像系统动态范围受限,常用的固定能量模式的X射线成像系统易出现过曝光和欠曝光共存现象,无法获取结构件的完整信息,影响图像分析及CT重建。对此,出现了能量自适应的X射线DR/CT成像方法,通过扩展成像系统的动态范围,实现复杂结构件的高灵敏度、高动态成像检测。本文对能量自适应的X射线DR/CT成像技术进行介绍,主要介绍能量自适应的实现及控制、不同能量投影图像融合和变能量CT图像重建方法,并对不同方法和算法的特点进行分析比较,最后对能量自适应CT的发展进行了总结和展望。

In X-ray 3D CT imaging for a complex structural component,because of the variations in the effective attenuation thickness of the component along the orientation of the X-ray penetration exceed the limit of the dynamic range of the X-ray imaging system,the traditional imaging model of fixed energy can’t obtain complete information with over-exposure and under-exposure coexistence.This will affect image analysis and CT reconstruction.To deal with this problem,energy-adaptive X-ray DR/CT imaging methods have emerged to achieve high-sensitivity in the inspection of complex structural components by extending the dynamic range of the imaging system.This paper introduces the energy-adaptive X-ray DR/CT imaging technology,mainly introduces the implementation and control of energy adaptation,fusion of different energy projection images and variable energy CT image reconstruction methods,and analyzes the characteristics of different methods and algorithms by comparison,and finally summarizes and outlooks the development of energy-adaptive CT.