Optimization and Construction of a Low-Field MRI System Using Permanent Magnets

A low-field tabletop spoke-and-hub permanent magnet array was constructed and assessed for homogeneity as a B0 field. Spatial encoding in the x and y directions was achieved by tilting the hubs relative to one other to generate a linearly increasing field in the tilt direction. A non-array RF coil was designed and optimized for low field strengths, where the signal-to-noise ratio is limited by the weak signal from the sample. The optimized coil design was tuned and matched to the resonant frequency of the spoke-and-hub magnet.