Timesharing coded hydrogen and sodium simultaneous magnetic resonance imaging method

Abstract

The invention discloses a timesharing coded hydrogen and sodium simultaneous magnetic resonance imaging method. Before and after hydrogen returning and assembling pulse, sodium is subjected to exciting twice, the same phase encoding and frequency encoding are performed twice in a timesharing manner, the applied encoding gradient overall effects do not influence the hydrogen, sodium images accumulated twice are obtained, and the signal to noise ratio of the sodium images is increased; and the intensity of a first damage gradient of a hydrogen nucleus is adjusted, when the first damage gradientof the hydrogen nucleus is applied, hydrogen phase encoding gradient and hydrogen reading-out preparation gradient are applied, additional pulse incidents are not added, and hydrogen nucleus T2 weighting effects the same as those of a conventional spin-echo imaging method can be obtained. Besides, the echo time of a sodium nucleus is effectively shortened, and when discrete-phase signals of the slice selective gradient direction and the reading-out gradient direction of two nucleus elements are both returned and assembled, consistent slice thickness of the hydrogen and the sodium is realized;and the image resolutions of the two reconstructed nucleus elements are consistent, and pixel positions are in one-to-one correspondence.

Description

technical field [0001] The invention relates to the technical field of magnetic resonance imaging, in particular to a hydrogen and sodium synchronous magnetic resonance imaging method for time-sharing coding. Background technique [0002] The image brightness and contrast of magnetic resonance imaging (MRI) are related to the density, relaxation parameters (T1, T2), diffusion coefficient, etc. of the measured nuclei in the sample. The difference in MRI signal intensity leads to the difference in MRI signal intensity, and this difference is used to separate various structures and tissue components. [0003] Water is abundant in the human body, and the nuclear magnetic sensitivity of hydrogen nuclei is high, and hydrogen ( 1 H) Become the nuclide of choice for human imaging, for the analysis of the structure and function of tissues or organs. Sodium ion ( 23 Na + ) is one of the ubiquitous electrolytes in living organisms, widely involved in the physiological and pathologi...

AI Technical Summary

Problems solved by technology

[0007] Aiming at the differences in the relaxation properties of hydrogen and sodium and the above-mentioned problems in the prior art, the present invention provides a time-sharing coded simultaneous magnetic resonance imaging method for hydrogen and sodium, which integrates spin echo and gradient echo imaging methods. , The frequency encoding and phase encoding of sodium are applied time-sharingly. In one scanning cycle, for hydrogen, the T2 weighted image of hydrogen is obtained by using spin echo imaging method; for sodium, the cumulative two times are obtained by using gradient echo The density-weighted image effectively improves the signal-to-noise ratio; at the same time, the layer thickness Th corresponding to the hydrogen and sodium images and the size of the inspection area FOV are kept consistent, and the pixels of the two nuclide images correspond one-to-one

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