Shimming control method, device and system for magnetic resonance imaging

Abstract

The present application relates to a shimming control method, device and system for magnetic resonance imaging. The method includes: obtaining the actual magnetic field distribution of the magnetic resonance imaging area; determining the spherical harmonic function expression of the actual magnetic field distribution; The target current value of the basic coil; wherein, the coil array is set in the magnetic resonance equipment for shimming the magnetic resonance; the kernel function of the coil array is determined according to the magnetic field vector distribution of each basic coil in the coil array; the imaging is performed based on the target current value Each basic coil corresponding to the area performs current control to realize shimming. This method applies the target current value determined according to the spherical harmonic function expression of the actual magnetic field distribution and the kernel function of the coil array to the basic coil corresponding to the imaging area in the coil array to achieve shimming, so that high-order shimming can be satisfied without superimposing the number of coils in space Require.

Description

technical field [0001] The present application relates to the field of magnetic resonance technology, in particular to a method, device and system for shimming control of magnetic resonance imaging. Background technique [0002] One of the greatest engineering challenges in modern magnetic resonance imaging (MRI) is delivering an ultra-strong, highly uniform magnetic field across the imaging region. To avoid loss or loss of signal due to spin phase changes during signal acquisition, MRI sequences may require spectral linewidths as low as around 40 Hz across the entire imaging region. This corresponds to ΔB ≈ 1 ppm field change for 1.0 TMRI, ΔB ≈ 1 / 3 ppm field change for 3.0 TMRI, and ΔB ≈ 1 / 7 ppm field change for 7.0 TMRI. Due to structural tolerances, such uniformity is nearly impossible to achieve in the manufacture of superconducting magnets. The non-uniformity of the original magnetic field generated by the superconducting magnet itself is generally in the hundreds of ...

AI Technical Summary

Problems solved by technology

However, in practice, due to space constraints, the number of spherical harmonic coils that can be added is limited

However, in high-field, especially ultra-high-field MRI imaging, the shimming of high-order spherical harmonics becomes more and more important, and the traditional dynamic shimming technology is difficult to meet the high-order shimming requirements

Images