开放式线圈屏蔽高场超导MRI磁体的优化设计

Optimization design of open high-field superconducting coil shielded MRI magnet

提出了开放式高场线圈屏蔽超导MRI磁体的混合优化设计方法,所设计的开放式MRI磁体仅有2对超导线圈。首先采用ISIGHT集成有限元分析软件ANSYS,构成协同式集成优化设计平台,设计磁体的主线圈和屏蔽线圈;然后提出改进的电磁场形状优化方法,设计磁体的匀场铁环,最后通过MATLAB运行遗传算法调用ANSYS进一步优化成像区域(Diameter of Spherical Volume,DSV)的磁场不均匀度,以达到高质量成像的要求。通过一个1.2T的开放式MRI磁体的设计实例清楚地展示了这种优化方法。

This paper presented a hybrid optimization method to design open high-field superconducting coil shielded MRI magnet with only two pairs of superconducting coils.Firstly,we used ISIGHT integrated finite element analysis software ANSYS,constituted collaborative design platform to design main coils and shield coils.Then we proposed an improved electromagnetic shape optimization method to design magnet shimming hoop.At last we used MATLAB Genetic Algorithm and ANSYS to improve the magnetic field uniformity in order to achieve high quality imaging requirements.In this paper,a 1.2T open MRI magnet design example clearly shows this optimization method.