Equivalent-charge-based optimization of spokes-and-hub permanent magnets for hand-held MR imaging

Abstract

The complex infrastructure needed for high-field magnetic resonance (MR) scanners has relegated this very safe, and remarkably revealing, clinical tool to high-end hospital care. But for many potential applications of MR -- point-of-care diagnostics, routine screening or classroom experimentation -- image quality is far less critical than portability and low cost. Emphasizing cost and portability over image quality has led researchers to focus on low-field MR, of the order of tens to hundreds of millitesla, generated using arrays of inexpensive permanent magnets. In this thesis, I describe a method for differentiating the potential from end-cap equivalent charges to efficiently compute the fields from bar magnets in a hundred- bar spokes-and-hub permanent magnet topology and demonstrate its potential as a low-cost MR imager.