Transverse dislocated absorption grating-based X ray grating differential phase contrast imaging method and device

An absorption grating and lateral dislocation technology, which is applied in the field of X-ray imaging, can solve the problems of low stability, low efficiency, and the X-ray grating differential phase contrast imaging method and device that have not yet been discovered.

CN107144581AActive Publication Date: 2017-09-08BEIHANG UNIV
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Patent Information

Authority / Receiving Office
CN · China
Current Assignee / Owner
Publication Date
2017-09-08

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Abstract

The invention discloses a transverse dislocated absorption grating-based X ray grating differential phase contrast imaging method and device. The method comprises the following steps: arranging a Talbot-Lau imaging structure by the novel transverse dislocated absorption grating disclosed by the invention; acquiring the two-dimensional intensity image after X ray penetrates through an object by the imaging structure; and separating the X ray absorption contrast image, differential phase contrast image and scattering contrast image from the acquired two-dimensional intensity image by the Fourier analysis method. Compared with the traditional method, the embodiment of the invention does not need to move the grating, three types of contrast images can be obtained by single exposure, so the imaging time is greatly shortened, the imaging dose is reduced and the imaging efficiency and stability of a system are improved.
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Description

technical field

[0001] The invention relates to the technical field of X-ray imaging, in particular to an X-ray grating differential phase contrast imaging method and device based on a laterally dislocated absorption grating. Background technique

[0002] In the X-ray imaging system, the X-ray source emits X-rays and illuminates a certain area of ​​the object to be detected. The detector placed opposite the X-ray source converts the X-ray signal attenuated by the object into a digital signal and sends it to the computer, thus forming The transillumination intensity image of an object can non-destructively characterize the medium density, composition, and structural morphology of the object in this area.

[0003] Traditional X-ray imaging can only obtain absorption contrast imaging of objects, and it is difficult to obtain high-contrast images of low atomic number material structure samples. In recent years, phase-contrast imaging techniques have been proposed to improve the...

Examples

Embodiment Construction

[0076] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

[0077] figure 1 The flow chart of the X-ray grating differential phase contrast imaging method based on the laterally dislocated absorption grating provided by the embodiment of the present invention; To solve the problems of large dose and low imaging efficiency, an X-ray grating differential phase contrast imaging method based on laterally dislocated absorption grating is provided. The specific steps of this method are as follows:

[0078] Step S101, placing each device according to the requirements of Talbot-Lau imaging optical path parameters.

[0079] The optical path parameters of the Talbot-Lau imaging structure should satisfy the following formulas (1)-(4):

[0080]

[0081] kg 1 = 2g 2 , (2)

[0082] g 0 =g 2 L / d, (3)

[0083] s2 · L / 2d, (4)

[0084] Among them, d represents the distance between the phase grating G1 and the...