MRI Multiple Excitation Diffusion Imaging Motion Correction Method

Abstract

The invention discloses a magnetic resonance multiple excitation diffusion imaging motion correction method, which includes: collecting multiple excitation magnetic resonance sequences; obtaining image echo signals and two-dimensional navigation signals through the magnetic resonance scanning sequence; and estimating motion through the two-dimensional navigation signals. Parameters; perform rotation and translation correction on the image echo signal and two-dimensional navigation signal according to the motion parameters, while discarding contaminated data to obtain correction data; integrate the corrected multiple excitation acquisition data for parallel imaging reconstruction; estimate through image registration algorithm The rotation motion parameters are used to correct the diffusion gradient of the reconstructed image; the corrected diffusion image and diffusion gradient are used for final calculation to obtain the diffusion tensor imaging parameters. This method can effectively correct various motion errors that occur during the magnetic resonance diffusion imaging scanning process, thereby obtaining high-resolution diffusion tensor images that eliminate artifacts, effectively reducing errors, and improving the accuracy of magnetic resonance diffusion imaging tensor parameter calculations. Spend.

Description

technical field [0001] The invention relates to the technical field of magnetic resonance diffusion imaging, in particular to a motion correction method for magnetic resonance multiple excitation diffusion imaging. Background technique [0002] Magnetic resonance diffusion weighted imaging can non-invasively detect the microscopic Brownian motion of water molecules in the human body, and provide information on microstructure and tissue function. It is an important neuroimaging technique and is widely used in clinical and research. [0003] Since diffusion imaging, especially high-resolution diffusion tensor imaging requires a long scanning time, the patient's involuntary movement is a problem that must be solved in clinical use. Methods such as immobilizing the patient's head not only make the patient uncomfortable, but also cannot completely prevent movement. Therefore, motion correction technology is a difficult point and a hotspot in high-resolution diffusion imaging of ...

AI Technical Summary

Problems solved by technology

The motion amplitude of the second kind of motion is smaller than the pixel size of the image, so it will not cause the overall position change, but if this kind of motion occurs when the diffusion gradient is applied, it will cause a sharp phase change of the image, resulting in the phase difference between different excitation data. Aliasing artifacts due to differences, so this type of motion must be corrected

The third type of motion is relatively large-scale motion. This type of motion can be defined as the position change between different excitations and acquisitions. If this type of motion occurs during gradient application, the acquired signal will be destroyed and the image will be difficult to recover. , if it occurs in other acquisition stages, the position difference between different excitations will lead to errors when integrating and reconstructing the data collected by different excitations, making it difficult to obtain an ideal image, resulting in problems such as blurring of the final diffusion image

[0004] Due to the existence of the second and third types of motion errors, the single-shot echo-planar technique is still the most widely used clinically, and the development of high-resolution diffusion imaging is limited.

High-resolution diffusion imaging with multiple shots faces three main motion-induced errors: (1) phase error due to small intra-pixel motion, which can cause severe aliasing artifacts; (2) The overall movement of the image caused by large movements produces blurred artifacts in the final image; (3) The direction of the diffusion gradient changes relative to the original coordinate system due to the rotational movement of the head, thus affecting the calculation of the final diffusion parameters

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