完全开放式磁共振成像磁体的优化设计

采用完全开放式的磁体结构，可满足外科手术对磁共振成像系统的需求。文章基于一种完全开放式的磁体结构——单边磁体结构的初始结构设计理论，构建了一个由块状永磁体组成的单边成像磁体的初始结构，并进一步应用改进的遗传算法对磁体结构进行了优化设计。最终达到提高其目标区域磁场强度、改善磁场均匀度的目的。数值结果显示，本文提出的设计方法给出的设计方案能够在磁体结构外部的成像区域形成均匀并且强大的主磁场。

Optimal Design of Completely Open Magnet for MRI

This paper presents a flexible design method to facilitate the construction of completely open magnet for Magnetic Resonance Imaging (MRI).The initial design is based on the monohedral magnet design method.Then the compensating parts are added to the initial monohedral magnet structure to improve the uniformity of the magnetic field in the imaging region.Furthermore,an improved genetic algorithm is used to optimize the magnet structure.Numerical implementations show that this method provides a main magnetic field with homogeneity and strength at the imaging region,which is defined outside of the magnet structure.