X-ray grating differential phase-contrast three-dimensional cone beam computerized tomography method and device based on transverse dislocation gratings

Abstract

The invention discloses an X-ray grating difference phase-contrast three-dimensional cone beam computerized tomography method and device based on transverse dislocation gratings. The method comprisesthe following steps: arranging a Talbot-Lau three-dimensional cone beam tomography structure by a transverse dislocation absorbing grating; acquiring the two-dimensional intensity image sequence of anX ray passing through an object through the structure; separating out an X-ray absorbing contrast image sequence, a differential phase-contrast image sequence and a scattering contrast image sequencefrom a collected two-dimensional intensity image by using a Fourier analysis method; and performing image reconstruction on the three contract image sequences to obtain three contract CT slicing images of the object by using an absorbing contrast filtered backprojection reconstruction algorithm, a differential phase contrast filtered backprojection reconstruction algorithm and a scattering contrast filtered backprojection reconstruction algorithm. Stepping of the absorption grating is not required, three contract CT slicing images can be obtained by a traditional CT scanning method based on X-ray attenuation, the imaging time is greatly shortened, the imaging dosage is reduced, and the system imaging efficiency and the stability are improved.

Description

technical field [0001] The invention relates to the technical field of X-ray computerized tomography, in particular to a method and device for three-dimensional cone-beam computerized tomography based on X-ray grating differential phase contrast with lateral displacement gratings. Background technique [0002] In the X-ray computer tomography (Computed Tomography, referred to as CT) system, the X-ray source emits X-rays, which pass through a certain area of ​​the object to be detected from different angles, and the detectors placed opposite the ray source receive them at corresponding angles. Then, according to the different degrees of attenuation of rays at various angles, a certain reconstruction algorithm and computer operations are used to reconstruct the distribution mapping image of the ray line attenuation coefficient in the scanned area of ​​the object, so as to realize the reconstruction of the image by projection and reproduce the object in this area without loss. ...

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Problems solved by technology

[0004] However, most of the existing differential phase contrast methods based on gratings are traditional methods based on the translation and stepping of absorption gratings. The imaging time is long, the dose is large, the stability is low, and the ...

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