Energy spectrum CT multi-base material rapid iterative decomposition method based on equation orthogonal correction

Abstract

The invention discloses an energy spectrum CT multi-base material rapid iterative decomposition method based on equation orthogonal correction, and the method comprises the steps: 1, scanning a measured object through employing different X-ray energy spectrums to acquire the multi-color projection data of the measured object; 2, assigning an initial value to each base material density image of themeasured object; 3, performing orthographic projection on the estimated value of the density image of each base material, and obtaining a multi-color projection estimated value according to the X-rayenergy spectrum information and the mass attenuation coefficient information of the substance; 4, calculating an error between the multi-color projection estimated value and the multi-color projection data, and solving the projection residual error of each base material by utilizing orthogonal correction; 5, obtaining an image residual error of each base material, and updating an estimated valueof a density image of each base material of the measured object; and 6, repeating the steps 3 to 5 until a termination condition is met. According to the invention, a plurality of base material density images of the measured object can be reconstructed according to the acquired multi-color projection data of the plurality of 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. Numerous fields. The traditional CT imaging theory assumes that X-rays are composed of photons of a single energy, ignoring the polychromaticity of X-rays. Therefore, beam hardening artifacts such as cupping artifacts and Streak artifacts seriously affect the image quality. [0003] Spectral CT uses X-ray energy spectrum under multiple energies to scan the measured object, and can measure more information about the measured object than traditional single-energy spectral CT. The informat...

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Problems solved by technology

Due to the nonlinearity and pathological nature of spectral CT reconstruction problems, existi...

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