Statistical iterative reconstructing method for low-dose X-ray CT image

Abstract

The invention discloses a statistical iterative reconstructing method for a low-dose X-ray CT image. The statistical iterative reconstructing method includes reconstructing an image for projection data y<raw> of the low-dose X-ray image of CT equipment to obtain an initial iterative image mu<init>; restoring the projection data y<raw> to obtain the restored projection data y<restored>, reconstructing an image for the restored projection data y<restored> to obtain a reference image mu<ref>; based on the reference image mu<ref> and the initial iterative image mu<init>, constructing an edge-preserving prior R (mu<init>) according to FORMULA (shown in the description), wherein phi () is an energy potential function, and SRNLM (mu<init>) is non-local mean filtering led by the reference image mu<ref>; performing iterative computation according to the edge-preserving prior R (mu<init>) of the initial iterative image mu<init> by means of a statistical iterative formula to obtain an iterative reconstructed image mu<iter>; when the iterative result of the reconstructed image mu<iter> satisfies the iteration stopping condition, stopping iterating, and obtaining the final reconstructed image of the low-dose X-ray CT image. The statistical iterative reconstructing method for the low-dose X-ray CT image is capable of effectively eliminating the image noise, inhibiting the streak artifact and well keeping the detail information of the image.

Description

technical field [0001] The invention relates to computer processing technology of medical images, in particular to a statistical iterative reconstruction method of low-dose X-ray CT images. Background technique [0002] X-ray CT scanning has been widely used in clinical medical imaging diagnosis, but excessive X-ray radiation dose during CT scanning may cause cancer risk. In order to reduce the damage to users, how to minimize the dose of X-rays has become one of the key technologies in the field of medical CT imaging. [0003] In order to reduce the X-ray radiation dose, the easiest way used in the prior art is to reduce the tube current and scanning time during the CT scanning process. On this basis, the prior art for low-dose X-ray CT image reconstruction mainly includes a filtered back-projection method and a statistical iterative reconstruction method. [0004] 1. Filtered Back-Projection (FBP). [0005] For low-dose X-ray CT images, the image reconstruction technolo...

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Problems solved by technology

[0009] However, the existing technology uses a statistical iterative reconstruction method based on edge-preserving priors. Since the stripe artifacts in low-dose CT reconstruction images are different from general image noise, the stripe artifacts are often preserved as an image structure, thus The strip artifact still exists in the low-dose CT reconstruction image, and cannot play the role of suppressing the strip artifact

Therefore, the statistical iterative reconstruction method based on the general edge-preserving prior in the prior art can effectively remove image noise, but cannot suppress the streak artifacts in the image

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