Designing method for gradient coil of self-shielding superconductive nuclear magnetic resonance imaging system

Abstract

The invention discloses a designing method for a gradient coil of a self-shielding superconductive nuclear magnetic resonance imaging system.The designing method comprises the steps that firstly, three-dimensional continuous triangular mesh dividing is performed on a main coil framework region and a shielding coil framework region, and an axial magnetic induction intensity coefficient matrix generated by mesh nodes in the main coil framework region and the shielding coil framework region on a target field point is calculated according to a boundary elements method; secondly, an optimization calculation model is built through a regularization method, wherein the optimization calculation model comprises two parts, the first part is deviation between the axial magnetic induction intensity generated by the mesh nodes in the main coil framework region and the shielding coil framework region on a target field point and the expected target magnetic induction intensity, the second part is the quadratic sum of the flow function curvature of the mesh nodes, and flow function values of the mesh nodes in the main coil framework region and the shielding coil framework region are obtained through solution; lastly, actual winding distribution of the gradient coil is obtained through a flow function method.

Description

technical field [0001] The invention relates to a design method for a gradient coil of a self-shielding superconducting nuclear magnetic resonance imaging system. Background technique [0002] The gradient coil is one of the components of the magnetic resonance imaging equipment, and its main function is to add another gradient magnetic field that increases (or decreases) according to the site on the main magnetic field, so as to spatially locate and encode the MRI signal. In actual work, the gradient coil system must provide at least three kinds of gradient magnetic fields, namely slice selection gradient, frequency encoding gradient and phase encoding gradient. The main indicators to measure the performance of gradient coils are imaging speed, resolution, noise level, etc. Improving the performance of gradient coils is of great significance to improving the performance of the entire nuclear magnetic resonance imaging system. [0003] The main goal of gradient coil design...

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Problems solved by technology

[0005] The purpose of the present invention is to overcome the shortcomings of unnecessary target magnetic field constraints in the existing self-shielding nuclear magnetic resonance imaging system design method, and propose a self-shielding superconducting nuclear magnetic resonance imaging system gradient coil design method

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