A method for registration of 3D CT and ultrasound liver images based on fast convex optimization algorithm

Abstract

The invention relates to the field of medical image post treatment, for the purpose of providing a rapid convex optimization algorithm based method for registering three-dimensional CT and ultrasonic liver images. The rapid convex optimization algorithm based method for registering the three-dimensional CT and ultrasonic liver image images comprises the following process: adjusting the resolution of ultrasonic images and CT images to be the same; performing rigid transformation based coarse registration on the ultrasonic images and the CT images; extracting unified characteristic information of multimodal image registration; calculating a D(u) in a data item and a partial D(u) of the D(u) under the condition of a non-rigid deformation field u(x); performing model solving on each step of a gradual convex optimization method to obtain a deformation field optimal rectification value h(x), and updating the deformation field until the h(x) is very small; and according to the solved non-rigid deformation field, transforming the ultrasonic images for registration with the CT images. According to the invention, through establishment of a reasonable model, a rapid and accurate three-dimensional ultrasonic-CT liver image registration algorithm is designed, and the accuracy, the safety and the effectiveness of an ablation operation are improved.

Description

technical field [0001] The invention relates to the field of post-processing of medical images, in particular to a method for registering three-dimensional CT and ultrasonic liver images based on a fast convex optimization algorithm. Background technique [0002] At present, liver disease is a disease with a relatively high incidence rate clinically, which directly threatens people's lives. In the treatment of liver cancer, local ablation therapy represented by radiofrequency ablation has become the third major liver cancer treatment method besides surgical resection and interventional therapy. Due to the advantages and disadvantages of ultrasound imaging, ultrasound-CT fusion is often used in ablation procedures to guide surgical needle insertion. The key technology is the registration of CT-ultrasound multimodal images. [0003] The registration of ultrasound images and CT images is still an international problem, and automatic and accurate real-time registration is stil...

AI Technical Summary

Problems solved by technology

[0003] The registration of ultrasound images and CT images is still an international problem, and automatic and accurate real-time registration is still difficult in actual clinical applications

There are many difficulties in liver ultrasound-CT registration, mainly including the following aspects: (1) Because the images of CT and ultrasound are very different, and the structures that can be visualized in CT may not be clearly seen in ultrasound, It is difficult to set the similarity measure of the two modalities, which belongs to the multimodal registration problem in the registration problem

(2) Due to the narrow field of view of ultrasound, the liver is the largest organ in the abdomen, and because of the occlusion of the abdominal bone, only part of the liver can be displayed in ultrasound images, and the complete liver cannot be displayed like CT; (3) Respiratory movement Effect on Image Registration Accuracy

Although this kind of registration by external markers is fast, it cannot achieve high accuracy, especially when dealing with local deformation.

These methods have their own advantages and disadvantages, and cannot completely solve the above problems.

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