Integral bucket phase measuring method for X-ray phase-contrast imaging

Abstract

The invention discloses an integral bucket phase measuring method for X-ray phase-contrast imaging. The integral bucket phase measuring method is applied to an X-ray phase-contrast imaging system and includes the steps: S1, on a transverse plane perpendicular to a light path, enabling an analysis grating to do continuous reciprocating linear movement in a grating period along the direction perpendicular to analysis grating grid bars, enabling a sample room to keep continuous rotation movement, and acquiring images by an X-ray detector in the period all the time; S2, calculating phase information of samples according to the acquired images in the S1. The analysis grating moves by one unit step, the detector acquires one image, namely, exposure time of one image is equal to time of the analysis grating moving by one unit step. The stability of a mechanical system in the fast X-ray phase-contrast imaging process can be ensured, and unnecessary radiation dosage received by the samples can be decreased.

Description

technical field [0001] The invention belongs to the technical field of X-ray phase contrast imaging, and in particular relates to an integral bucket phase measurement method for X-ray phase contrast imaging. Background technique [0002] X-ray phase contrast imaging technology has great application prospects in the identification and resolution of biological soft tissues. In the current X-ray crystal interferometer-based and grating-based X-ray phase contrast imaging techniques, the phase stepping measurement method is often used to extract the phase information of the sample. In the X-ray crystal interferometer, the phase step is realized mainly by moving the wedge-shaped phase shifter step by step [1, 2]. In the grating-based X-ray phase contrast imaging technology, the phase stepping is mainly achieved by moving the analytical grating step by step [3, 4, 5, 6]. [0003] [1] A. Momose, "Demonstration of phase-contrast X-ray computed tomography using an X-ray interferomet...

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Problems solved by technology

[0009] The phase information of the sample can be accurately measured by phase stepping technology, but there are two main disadvantages of the phase stepping measurement method: (1) The motion mode of the X-ray phase contrast imaging system is intermittent, and the phase shifter / analyzer The grating moves one step, the detector acquires an image, then the phase shifter / analysis grating moves one step further, the detector acquires another image, until the image is acquired

In fast X-ray phase-contrast imaging, this discontinuous motion affects the stability of the mechanical system

(2) During the movement of the phase shifter / analysis grating, the image acquisition stops, but the sample is still receiving the radiation dose (in the phase stepping measurement technique, there are two ways to solve this problem, one method is to phase shift During the movement of the detector / analysis grating, use the lead plate to block the X-rays. After the movement of the phase shifter / analysis grating is completed, remove the lead plate and continue to start image acquisition. This can avoid unnecessary radiation damage to the sample, but this method increases The structural complexity of the imaging system is eliminated; another method is to turn off the X-ray machine during the movement of the phase shifter / analysis grating, and restart the X-ray machine after the phase shifter / analysis grating movement is completed. This method can also Avoid unnecessary radiation damage to the sample, but the disadvantage of this method is that the X-ray machine cannot be in a continuous and stable working state, and the photon flux emitted by the X-ray machine is unstable, which will cause a decline in the imaging quality of the system)

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