Base image TV model based CT (Computed Tomography) beam hardening correcting method

Abstract

The invention relates to a CT (Computed Tomography) transmission imaging beam hardening correcting method and particularly relates to a base image TV minimized model based CT beam hardening correcting method. On the basis of establishing a beam hardening correcting model with an adjustable parameter, the base image TV model based CT beam hardening correcting method comprises the following steps: firstly, converting an original projection data through the model pretreatment so as to obtain sets of pretreated projection sequences under different adjustable parameter conditions; respectively reconstructing the pretreated projection sequences, thereby obtaining a series of corrected base images; taking a full-variation function of a target image as a cost function and obtaining an optimal solution of a weighting coefficient according to an iterative method; and lastly, summing the weights of the obtained series of base images, thereby forming a final reconstructed image. Compared with the traditional method, the method provided by the invention has the advantages that the priori knowledge, such as scanning copy material, radiation source condition, and the like, is unnecessary, the method is unlimited by external conditions and is strong in universality, and the linear combination is solved when a weighting coefficient is confirmed, so that the method has the advantages of small computation complexity and short operation time.

Description

technical field

[0001] The invention relates to a beam hardening correction method for CT transmission imaging, in particular to a CT beam hardening correction method based on a base image TV minimization model. Background technique

[0002] CT (Computed Tomography, CT) technology is an imaging technology that uses a detector to perform a series of ray projection measurements at different angles on the detected object, and directly calculates all slice images of the object through a three-dimensional image reconstruction algorithm. It is used in industrial non-destructive testing and medical applications. There is a wide range of applications in the field.

[0003] The CT reconstruction algorithm is based on the following assumptions: the X-rays used are monoenergetic, the ray intensity decays exponentially with the increase of the thickness of the absorbing material, and the attenuation coefficient is constant. The rays emitted by the actual X-ray source are multi-energy s...

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