A Fast Iterative Decomposition Method for Energy Spectral CT Multi-base Materials Based on Equation Orthogonal Correction

Abstract

The invention discloses a fast iterative decomposition method for energy spectrum CT multi-base materials based on equation orthogonalization correction. The method includes: step 1, using different X-ray energy spectra to scan the measured object, and obtain the multi-base material of the measured object. color projection data; step 2, assign initial values ​​to the density images of each base material of the measured object; step 3, perform orthographic projection on the estimated values ​​of the density images of each base material, and use the X-ray energy spectrum information and the mass attenuation coefficient of the substance information, obtain the estimated value of multi-color projection; step 4, calculate the error between the estimated value of multi-color projection and multi-color projection data, and use orthogonal correction to solve the projection residual of each base material; step 5, obtain the image residual of each base material difference, and update the estimated value of each base material density image of the measured object; step 6, repeat steps 3 to 5 until the termination condition is satisfied. The invention can reconstruct a plurality of base material density images of the measured object from the multicolor projection data of the collected energy spectrums.

Description

technical field [0001] The invention relates to the technical field of X-ray CT imaging, in particular to a fast iterative decomposition method for energy spectrum CT multi-base materials based on equation orthogonalization correction. Background technique [0002] X-ray Computed Tomography (X-ray CT for short) can present the internal details of objects without destroying or damaging them, and has been widely used in medicine, biology, industry, materials, ancient fossils, aerospace, etc. many fields. The traditional CT imaging theory assumes that X-rays are composed of photons of a single energy, ignoring the pleochroism of X-rays, so beam hardening artifacts such as cupping artifacts and Striping artifacts, which seriously affect the imaging quality. [0003] Energy spectral CT scans the measured object using X-ray energy spectra at multiple energies, and can measure more information about the measured object than traditional single energy spectral CT. Using this infor...

AI Technical Summary

Problems solved by technology

Due to the nonlinearity and pathological nature of spectral CT reconstruction problems, existing spectral CT reconstruction algorithms cannot quickly reconstruct high-quality base material images

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