Small-view-field magnetic resonance imaging method based on single-sweep super-speed orthogonal space-time coding

Abstract

The invention discloses a small-view-field magnetic resonance imaging method based on single-sweep super-speed orthogonal space-time coding. The method comprises the following steps of: enabling protons in a space to automatically rotate in an excitation phase by virtue of the organic combination of an orthogonally-distributed space coding gradient and a linear frequency sweep pulse to acquire a secondary phase related to a space position, thus carrying out two-dimensional space-time coding on the automatic rotation of the protons in an imaging plane; for the automatic rotation of the protons in an orthogonal space-time coding space, only the automatic rotation of the protons with static phase distribution can be detected during a decoding sampling period, and according to the characteristic of orthogonal space-time coding, decoding sampling can be carried out on a plurality of randomly-distributed areas in the space by designing a decoding sampling gradient, thus acquiring the magnetic resonance data of a plurality of areas of interest finally. High-resolution reconstruction is sequentially carried out on acquired magnetic resonance data of the plurality of areas, and then the high-resolution small-view-field magnetic resonance images of the plurality of areas can be obtained finally.

Description

technical field [0001] The invention relates to a method of magnetic resonance imaging, in particular to a method for obtaining high-resolution magnetic resonance imaging of a plurality of discretely distributed regions in a single scan. Background technique [0002] Echoplanar imaging (EPI) performs rapid sampling through a series of rapidly switched gradient echoes, and a magnetic resonance image can be obtained with one excitation. With its high signal-to-noise ratio and ultra-fast imaging speed, EPI has gradually become the preferred imaging method for high-dimensional imaging such as functional neuroimaging (functional neuroimaging) and diffusion tensor imaging (diffusion tensor imaging, DTI). However, the EPI imaging method seriously affects its application effect due to its inherent problems, such as ghost and ring artifacts, and image distortion caused by non-uniform magnetic susceptibility. These issues severely damage image quality and limit spatial resolution. T...

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Problems solved by technology

Some existing small field of view methods, including space saturation method, orthogonal excitation method, two-dimensional pulse excitation method, but the performance in the single-scan imaging sequence is not satisfactory, either there are still other signals remaining in the final data, or Very susceptible to inhomogeneous fi

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