Design method of bi-planar shimming coil

Abstract

The invention discloses a design method of a bi-planar shimming coil. According to the design method, the source point grid of a biplanar shimming coil is imported; grid vertexes and triangular surfaces are sequenced; the magnetic field values of a second-order shimming coil on target points are calculated through a spherical harmonic function; MATLAB software is adopted to read each vertex and each surface of the triangular grids; the arrangement sequence of the vertexes and surfaces is optimized; the size of a wire is set according to a boundary element method; the value of the contributionof an electrified wire in a source point region to field points is calculated; the energy storage and power consumption of the bi-planar shimming coil are constrained to be minimum; current density distribution on the biplanar shimming coil is solved; and the winding shape of the bi-planar shimming coil is obtained through a stream function method. With the design method of the bi-planar shimmingcoil adopted, harmonic magnetic fields of a second order or higher orders can be eliminated, so that the uniformity of a main magnetic field is improved, and the image quality of an open type MRI system is improved.

Description

technical field [0001] The invention relates to the field of magnetic resonance imaging, in particular to a design method of a double-plane shim coil. Background technique [0002] Magnetic resonance imaging (Manetic Resonance ImagingMRI) technology is a technology that crosses multiple technologies, including electromagnetics, digital signal processing, biomedicine and atomic physics. Compared with other medical imaging technologies, MRI has no radiation and high resolution. and clear image quality, so MRI technology has important clinical application value in medical examination. Ideally, the main magnetic field of MRI equipment is only B0 field, and there are no other harmonic magnetic fields. Avoid the introduction of harmonic magnetic fields that are not B0 fields. The introduction of harmonic magnetic fields will make imaging quality worse or even impossible. Gradient coils can correct the first-order harmonic magnetic field, and the magnetic field higher than the firs...

AI Technical Summary

Problems solved by technology

[0002] Magnetic resonance imaging (Manetic Resonance ImagingMRI) technology is a technology that crosses multiple technologies, including electromagnetics, digital signal processing, biomedicine and atomic physics. Compared with other medical imaging technologies, MRI has the advantages of no radiation and high resolution. and clear image quality, so MRI technology has important clinical application value in medical examination. Ideally, the main magnetic field of MRI equipment is only B0 field, and there are no other harmonic magnetic fields. Avoid the introduction of harmonic magnetic fields that are not B0 fields. The introduction of harmonic magnetic fields will make imaging quality worse or even impossible. Gradient coils can correct the first-order harmonic magnetic field, and the magnetic field higher than the first-order harmonic requires second-order and above The shimming coil is used to eliminate it, so that the B0 field reaches the range required by the imaging

[0003] In order to solve the above-mentioned problem of inhomogeneity of the main magnetic field of the open MRI magnet, the patent of the present invention proposes a design method of a double-plane shim coil

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