Image distortion correction method based on single-scanning mixed space-time coding magnetic resonance imaging

Abstract

The invention relates to an image distortion correction method based on single-scanning mixed space-time coding magnetic resonance imaging. The method is characterized by including the steps that (1)firstly, an area-of-interest of a to-be-imaged object is positioned; (2) a single-scanning mixed space-time coding sequence which is compiled in advance is guided into a nuclear magnetic resonance imager; (3) data sampling is performed; (4) the effective peak value center position of each sampled return wave is determined; (5) the deviation point number of the return wave center position of each return wave peak value center position under the condition relative to the ideal condition in an non-uniform field is calculated; (6) the gradient skewing area caused by skewing of each return wave peak value position in the non-uniform field is calculated; (7) the effective return wave time of each return wave signal is calculated; (8) an equivalent non-uniform-field magnetic susceptibility gradient value Ginh is calculated; and (9) distorted images are corrected through the equivalent non-uniform-field gradient value obtained in the step (8). According to the method, the robustness of a traditional phase coding direction non-uniform field is achieved.

Description

technical field [0001] The invention relates to an image distortion correction method based on single-scan mixed space-time encoding magnetic resonance imaging. Background technique [0002] The Human Brain Project (HBP) is another major international scientific research project after the Human Genome Project. Magnetic resonance imaging plays an important role in the study of brain deciphering. Not only can the division of the anatomical structure of the brain be realized, but also functional imaging can be performed to decipher the advanced cognitive functions of the brain. Therefore, functional magnetic resonance imaging is recognized as the most effective imaging method for analyzing brain function. Ultra-fast imaging technology plays an important role in functional imaging, such as Arterial Spin Labeling (ASL) technology for quantitative measurement of blood perfusion in brain tissue, diffusion tensor imaging (Diffusion Tensor Imaging) for revealing the direction of br...

AI Technical Summary

Problems solved by technology

However, by summarizing the research of previous scholars, it is found that both the distortion correction method based on EPI ultra-fast imaging and the distortion correction method based on SPEN ultra-fast imaging have some limitations.

For example, most of the distortion correction based on the EPI method requires an additional B 0 Field image scanning, so it cannot be applied to some MR navigation interventional operations and the continuous movement of imaging parts; the distortion correction based on SPEN ultra-fast imaging is mainly in the rapid sampling continuous excitation and refocusing sequence (Rapid acquisition by sequential excitation and refocusing , RASER) and biaxial spatiotemporally-encoded (bi-SPEN) sequence variant sequence basis

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