Limited angle CT image reconstruction algorithm based on boundary-preserving diffusion and smoothing

Abstract

The invention discloses a limited angle CT image reconstruction algorithm based on boundary-preserving diffusion and smoothing. The algorithm comprises the steps of inputting a variable; performing initialization; assuming that an estimated image u(k) has been obtained, using the u(k) as an initial value, scanning a data set p by using a limited angle CT, updating the estimated image u(k+1/3)=RG(p, u(k)); performing the boundary-preserving diffusion correction in the x-axis direction on the image u(k+1/3) to obtain u(k+2/3) =P(u(k+1/3)); performing the boundary-preserving smoothing correctionin y-axis direction on the image u(k+2/3) to obtain u(k+1)=S(u(k+2/3)); determining whether a difference between two adjacent iterative images is less than a given threshold, or whether the upper limit of iteration times reaches N, terminating the iteration if so, otherwise starting the new iteration with the u(k+1) as the initial value until the condition is satisfied, and ending the limited angle CT image reconstruction algorithm based on boundary-preserving diffusion and smoothing. The algorithm of the invention eliminates the image blurring and the limited angle artifact caused by the lackof the boundary-preserving diffusion elimination angle, and simultaneously eliminates the possible linear artifacts introduced by the boundary-preserving smoothing diffusion, thereby improving the quality and usability of the limited angle CT image.

Description

technical field [0001] The invention belongs to the technical field of X-ray CT imaging, and relates to a limited-angle CT image reconstruction algorithm based on boundary-preserving diffusion and smoothing. Background technique [0002] Since its invention, CT technology has been widely used in medical diagnosis, industrial non-destructive testing and safety inspection and other fields. In some important applications, due to limited conditions, it is difficult to obtain projection data at some angles, which leads to limited-angle CT imaging problems, such as breast imaging in medicine, imaging of large-scale plate objects in industrial non-destructive testing, etc. [0003] Limited-angle CT imaging is an incomplete data imaging problem. The images directly reconstructed by traditional image reconstruction algorithms (such as FDK, SART, etc.) have image blur along specific directions and finite-angle artifacts. The more angles are missing, the more serious the blur , affect...

AI Technical Summary

Problems solved by technology

In some important applications, due to limited conditions, it is difficult to obtain projection data at some angles, which leads to limited-angle CT imaging problems, such as breast imaging in medicine, imaging of large-scale plate objects in industrial non-destructive testing, etc.

[0003] Limited-angle CT imaging is an incomplete data imaging problem. The images directly reconstructed by traditional image reconstruction algorithms (such as FDK, SART, etc.) have image blur along specific directions and finite-angle artifacts. The more angles are missing, the more serious the blur , affecting the availability of CT images

[0004] Through the search, no patent publications related to the patent application of the present invention have been found

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