A kind of superconducting magnet and its shimming device and shimming method

Abstract

The present invention proposes a shimming device for a superconducting magnet, which is characterized in that the shimming device includes: at least two shimming elements and at least two screw rods; each screw rod assembly is nested layer by layer, starting from the most From the outer layer to the innermost layer, the length of each of the screw rods increases successively; the head of the screw rod is provided with threads; each of the shims has a through hole, and each of the through holes is provided with the corresponding Threads matching the rod heads are installed on the corresponding rod heads respectively, wherein the shims can move in translation along the axial direction of the screw rods when the corresponding screw rods rotate. The present invention effectively improves the FOV range of the superconducting magnet by providing shimming elements in the entire superconducting magnetic field range; at the same time, the present invention effectively improves each shimming element by using nested multiple screw rods to control each shimming element respectively. The flexibility of the location of the shims in the shim channel also effectively improves the flexibility of the number of shims by placing the shims in the shims.

Description

technical field [0001] The invention relates to the technical field of magnetic resonance imaging, in particular to a superconducting magnet of a magnetic resonance system, a shimming device and a shimming method thereof. Background technique [0002] In an existing magnetic resonance system, a superconducting magnet can be used to generate a magnetic field, and then the magnetic field can be used to perform magnetic resonance imaging. In order to ensure image quality, there are high requirements on the uniformity of the magnetic field in the field of view (FOV). Superconducting magnets are usually annular columnar structures. Due to manufacturing errors, material differences, and environmental changes, the magnetic field in the imaging area (FOV) is usually inhomogeneous. Therefore, certain measures need to be taken to correct for imaging quality. Good MRI image. [0003] Specifically, in the existing magnetic resonance system, the cylindrical superconducting magnetic fie...

AI Technical Summary

Problems solved by technology

[0010] 1. According to the existing technology, if only one shim is installed on the device used to move the shim, it is difficult to cover a large magnetic field range, so the shimming efficiency for a larger imaging area (FOV) needs improvement;

[0011] 2. According to the prior art, when multiple shims are installed on the device for moving the shims, the positions of these shims are relatively fixed, that is, the positions of these shims cannot be adjusted independently, so The shimming efficiency needs to be improved in terms of controlling the position of the shimming element;

[0012] 3. According to the existing technology, the shims are integrally formed, that is, the size or composition of a single shim cannot be adjusted, so the shim efficiency needs to be improved in terms of the size or composition of the shims;

[0013] 4. According to the existing technology, the shimming parts are integrally formed, but the integrally formed shimming parts are greatly affected by eddy currents: when the magnetic field is working, the temperature of the shimming parts will rise, and the temperature change will cause shimming The magnetic changes of the parts, so the shimming stability needs to be improved

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