Optimized configurations for actively shielded magnetic resonance imaging magnets

A unique design approach based on the multistage Monte Carlo method is suggested. It allows for a thorough search for optimized designs within the bounds of the multidimensional design space created by the competing requirements and imposed spatial restrictions. This design space is shown to contain a multiplicity of different coil configurations, each processing a sharply defined minimum in the resulting stray field level, field inhomogeneity, or amount of conductor. Optimization techniques that depend on local gradients would tend, in such a case, to be trapped in the many local minima and fail to locate a global minimum. Several examples are discussed to highlight the advantages of the proposed design approach