Optimized K-edge imaging method

Abstract

The invention discloses an optimized K-edge imaging method. According to the method, imaging is performed at front and rear X-ray energy sections of K-edge to improve the known material imaging contrast. The widths of the front and rear X-ray energy sections of the K-edge determine the contrast and the noise level of two energy spectrum CT (Computed Tomography) images; aiming at the problem of way of setting the widths of the front and rear X-ray energy sections of the K-edge, a signal difference to noise ratio (SDNR) is introduced as an optimization criterion; under the constraint of the optimization criterion, the width of the optimal X-ray energy section is selected, and then K-edge imaging is performed. According to the imaging method, the greatest contrast difference can be obtained while the miniaturization of noise of two reconstructed energy spectrum CT image interesting regions is guaranteed, so that the purpose of improving the known material imaging contrast is achieved. The method can be used for the field of biomedical CT imaging.

Description

technical field [0001] The invention belongs to the field of X-ray energy spectrum CT imaging, and in particular relates to an optimized K-edge imaging method. Background technique [0002] K-edge is a physical phenomenon, also called K-absorption edge. As the energy of X-rays increases, the attenuation coefficient of X-rays to substances gradually decreases, but certain substances absorb X-ray photons at specific energies particularly large, resulting in a sudden increase in the attenuation coefficient of X-ray photons. The phenomenon that the X-ray attenuation coefficient increases suddenly is called K-edge. From the perspective of quantum physics, the free electrons in the electron layer (K ​​electron layer) closest to the nucleus in the material atom are easy to interact with X-ray photons at a specific energy (photoelectric absorption), resulting in the X-ray photons of this energy. Ray photons are particularly absorptive. Different elements have different atomic str...

AI Technical Summary

Problems solved by technology

Therefore, the problem to be solved in the present invention is how to set the width of the two X-ray energy segments before and after the K-edge, so as to ensure that the noise in the region of interest of the two reconstructed energy spectrum CT images is minimized while obtaining the maximum contrast difference, thereby improving the existing Known material imaging contrast

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