A Time-Sharing Coding Method for Simultaneous Hydrogen and Sodium Magnetic Resonance Imaging

Abstract

The invention discloses a method for synchronous magnetic resonance imaging of hydrogen and sodium with time-sharing encoding. Before and after the hydrogen recombination pulse, the sodium is excited twice, and the same phase encoding and frequency encoding are performed twice in time-sharing, and the applied encoding gradient is overall Effect, no effect on hydrogen, two accumulated sodium images are obtained, which improves the signal-to-noise ratio of the sodium image; adjust the intensity of the first damage gradient of the hydrogen nucleus, and apply the first damage gradient of the hydrogen nucleus at the same time Hydrogenation phase encoding gradients and hydrogen readout preparation gradients do not add additional pulse events, and can obtain the same T2 weighting effect of hydrogen nuclei as conventional spin echo imaging methods. At the same time, the echo time of the sodium nucleus is effectively shortened, ensuring that the scattered-phase signals in the gradient direction of the layer selection gradient and the readout gradient direction of the two nuclides are all gathered together, and the layer thickness of hydrogen and sodium is consistent; the two nuclides are reconstructed The image resolution is the same, and the pixel positions correspond to each other one by one.

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

Images