X-ray diffraction enhanced imaging method based on iterative algorithm

Abstract

The invention discloses an X-ray diffraction enhanced imaging method based on an iterative algorithm. The method is applied to a diffraction enhanced imaging system composed of an X-ray source, a monochromatic crystal, an analysis crystal and a detector which are sequentially arranged in the X-ray propagation direction. X-rays are incident to the surface of the monochromatic crystal to be diffracted; emergent monochromatic collimated X-rays are diffracted after penetrating through an imaged object and entering the surface of the analysis crystal; after emergent X-rays are incident to the detector, the intensity of X-rays is detected and recorded by the detector, the normal of the diffraction surface of the analysis crystal is used as a rotating shaft, and the detector is used for recordingprojection data of the analysis crystal at three different angular positions, so that a proposed iterative algorithm is used for processing the projection data recorded by the detector, and absorption, refraction and scattering signals of an imaged object are obtained. The method can solve the problem of accurate extraction of the refraction signal and the scattering signal of the imaged object when the bias of the light intensity curve is not zero.

Description

technical field [0001] The invention relates to the field of X-ray imaging methods, in particular to an iterative algorithm-based X-ray diffraction enhanced imaging method. Background technique [0002] After more than 100 years of continuous development, X-ray imaging technology has been widely used in many fields such as clinical medical diagnosis and treatment, public safety inspection, and material science. For objects containing heavy metal elements, X-ray absorption contrast imaging technology can be used to obtain good imaging results. However, for objects mainly composed of low atomic number elements such as organic composite materials and human soft tissues, their attenuation to X-rays is very weak, and the image quality obtained by using absorption contrast imaging technology is very poor. In order to overcome this limitation, scientists have successively developed a series of multi-mode X-ray imaging methods as a powerful supplement to traditional absorption cont...

AI Technical Summary

Problems solved by technology

The multi-image statistical method requires: take the normal line of the diffraction surface of the analyzed crystal as the axis of rotation, step-scan the angular position of the analyzed crystal, and collect dozens of projection images, resulting in a long data collection time and reducing the experimental efficiency; The imaged object is exposed multiple times (generally dozens of times in experiments), which increases the risk of radiation damage to the imaged object

More importantly, when the bias of the light intensity curve is not zero, the multi-map statistical method cannot accurately extract the refraction signal and scattering signal of the imaged object

These limitations hinder the popularization and application of X-ray diffraction enhanced imaging in the fields of dynamic multi-mode imaging and quantitative characterization of porous materials.

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