The Optimal Design of an Improved Monohedral Magnet for MRI

A monohedral magnet satisfies the requirement of a MRI system for the surgical procedure. This paper presents a flexible design method to facilitate the construction of permanent magnet assemblies with completely open architecture for MRI. The initial design is based on the ideally analytical assumptions. Then the dimensions and orientation (directions of the magnetization) of each permanent magnet block are optimized by using Evolution (1+1) algorithm to satisfy the inter-conflicted objective functions. Numerical implementations show that the optimized architecture provides a magnetic field with sufficient homogeneity and strength in the imaging region, and minimizes the cost of the MRI equipment