Ray scattering imaging system based on aperture coding technique

Abstract

The invention relates to a ray scattering imaging system based on an aperture coding technique. The ray scattering imaging system comprises a ray source, a front collimator, an array detector, an aperture coding mask, a signal processor, a controller and a moving device, wherein the front collimator is arranged between the ray source and a detected object, is static relative to the ray source and is used for collimating rays of the ray source into a ray beam; the intersecting line between the central normal surface of the array detector and the ray beam is a scanning line; the aperture coding mask is a one-dimensional aperture coding mask, is formed by the arraying of a plurality of coding units, is arranged between the array detector and the detected object and is static relative to the array detector; the signal processor is used for converting analog signals obtained by the array detector into digital signals; the controller is used for recombining and decoding the digital signals to acquire scattered images corresponding to voxels on the scanning line; the moving device is used for integrally driving the ray source and the array detector to move relative to the detected object. The ray scattering imaging system has the beneficial effects that the advantages of the prior art are integrated, the transmittance of the scattered ray are not substantially decreased, and the signal to noise ratio is high.

Description

technical field [0001] The invention relates to the technical field of image detection, in particular to a ray scattering imaging system based on aperture coding technology. Background technique [0002] X-ray scattering imaging technology (hereinafter referred to as scattering imaging) is a new non-invasive imaging technology based on the Compton scattering effect. It is obviously different from traditional transmission imaging technology in imaging principle, device arrangement and applicable target. The traditional transmission imaging is to obtain the total attenuation coefficient of the measured object in the transmission direction through the intensity of the transmitted rays, and obtain the object image. Its ray source and detector must be placed on both sides of the sample. It is more sensitive to substances with large attenuation coefficients (such as heavy metals) than to substances with small attenuation coefficients (such as organic substances), and the image sp...

AI Technical Summary

Problems solved by technology

Although the "flying spot scanning" method is mature, it has the following defects: (1) The utilization rate of X-rays is low, and the beam needs to be collimated into a pencil shape first; (2) The signal-to-noise ratio and spatial resolution cannot be balanced, and the X-ray The beam needs to scan each voxel point by point. If the voxel segmentation is small, the residence time of the ray beam is very short, and the detection unit often significantly reduces the signal-to-noise ratio due to insufficient signal reception. However, if the voxel segmentation is large, the spatial resolution (3) The scanning speed is slow, limited by the requirements of the image signal-to-noise ratio and the mechanical rotary drive device, which is not suitable for high-throughput applications; (4) The mechanical structure is complicated, and a special rotary drive device is required to drive the cutting machine. The wheel collimator can only work, and the failure rate is high

However, traditional collimation devices (pinhole collimator or parallel hole collimator) still only allow scattered rays in a specific direction to pass through, which limits the improvement of system detection efficiency and sensitivity.

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