Phase-absorption inversion and material quantitative imaging method based on coaxial CT

Abstract

The invention discloses a phase-absorption inversion and material quantitative imaging method based on coaxial CT. The method comprises the steps of 1, building an O-XYZ coordinate system, enabling the origin of the O-XYZ coordinate system to be the geometric center of a measured object, and enabling the Z axis to be the emergent direction of a synchrotron radiation light source, 2, scanning the measured object rotating around the Y axis by using a synchrotron radiation light source, 3, according to the scanning parameters and the measured object parameters in the step 2, assigning initial values to the absorption image and the phase image to be reconstructed, 4, calculating the plane light intensity of the nth iteration of the measured object at the projection angle j, 5, calculating thelight intensity residual error of the measured object after the nth iteration at the projection angle j, 6, carrying out iterative reconstruction on gn(x, z) and fn(x, z) to obtain a reconstructed absorption image fn+1(x, z) and a reconstructed phase image gn+1(x, z), 7, removing an air non-zero value in the image, and decomposing the base material, and 8, if the stop condition is met, stopping iteration. Quantitative imaging of simultaneous iterative reconstruction of the phase-absorption images can be directly performed according to the distance light intensity data from the single measuredobject to the detector.

Description

technical field [0001] The invention relates to an imaging method, in particular to a phase-absorption inversion and material quantitative imaging method based on coaxial CT. Background technique [0002] X-ray imaging technology is widely used in many fields, such as biomedicine, industry and security inspection, etc. Traditional X-ray CT is based on the differences in the absorption of radiation between different substances or tissues. However, this X-ray imaging technology based on the absorption mechanism is not ideal for imaging materials composed of light elements (such as muscles, blood vessels, and breasts, etc.) . When the X-ray photons are within a certain range, the X-ray phase change caused by the light element substance is 10 of its absorption value 3 Therefore, X-ray phase contrast imaging (XPCI) has a higher sensitivity than X-ray absorption contrast imaging (XACI) for observing the internal structure of the measured object. The use of phase contrast itself...

AI Technical Summary

Problems solved by technology

Traditional X-ray CT is based on the differences in the absorption of radiation between different substances or tissues. However, this X-ray imaging technology based on the absorption mechanism is not ideal for imaging materials composed of light elements (such as muscles, blood vessels, and breasts, etc.)

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