Method for obtaining number and initial positions of solenoid coils of magnetic resonance imaging superconducting magnet

Abstract

The invention discloses a method for obtaining the number and initial positions of solenoid coils of a magnetic resonance imaging superconducting magnet. According to the method, two-dimensional continuous mesh generation is carried out on a pre-arranged coil area (1), the maximum axial and radial magnetic induction intensity at each mesh point (4) is added as a constraint condition and the relation between an objective function and the optimization variable and the relation between the constraint condition and the optimization variable are expressed to be a linear programming mathematic model under the condition that magnetic field evenness of a target point on the imaging area spheroid surface (2) and axial and radial magnetic induction intensity of a target point on the constraint cylinder surface of a 5 gauss stray magnetic field are lower than design requirements of the 5 gauss, and a current distribution diagram on the two-dimensional mesh points (4) which meet all constraint conditions and when the number of the objective functions is the smallest can be solved. The current distribution diagram is composed of a plurality of nonzero current clusters, the number and initial position parameters of the solenoid coils needed by the magnetic resonance imaging superconducting magnet can be distinguished clearly through the distribution of the nonzero current clusters.

Description

technical field [0001] The invention relates to an electromagnetic design method for a high-uniformity superconducting magnet in magnetic resonance imaging, in particular to a solenoid coil number and How to get the initial position. Background technique [0002] Magnetic resonance imaging superconducting magnets need to generate a spatial magnetic field with highly uniform distribution of axial magnetic induction intensity in an imaging region. For a whole-body imaging system, the general imaging area is a sphere or ellipsoid with a diameter of 40-50 cm, and the peak-to-peak unevenness of the magnetic field must be better than 20 ppm. Highly uniform spatial magnetic field distribution usually needs to be achieved by multiple pairs of solenoid coils, and the number and position parameters of the solenoid coils are the difficulties in the electromagnetic design of superconducting magnets for magnetic resonance imaging. [0003] Usually, the solenoid coils that make up the M...

AI Technical Summary

Problems solved by technology

[0006] The purpose of the present invention is to overcome the difficulty in prior determination of the number of required solenoid coils and the difficulty in constraining the maximum axial and radial magnetic induction in the solenoid coils in the existing magnetic resonance imaging superconducting magnet electromagnetic design method To solve the shortcomings, a method for obtaining the number and initial position of solenoid coils in a superconducting magnet for magnetic resonance imaging is proposed

Images