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Abstract #3081

First-To-Fourth Order Spherical Harmonics Shimming with a Grid of Circular Electrical Coils

Christoph Juchem1, Douglas L. Rothman1, Robin A. de Graaf1

1Diagnostic Radiology, MRRC, Yale University School of Medicine, New Haven, CT, USA

Magnetic field inhomogeneity is typically decomposed into low-order (n≤4) spherical harmonic functions. In order to compensate the inhomogeneity MR scanners have specialized built-in electrical coils, each of which can create one spherical harmonic field term. Here we propose the use of a grid of 100 local coils to generate spherical harmonic fields instead of one dedicated coil per term. Based on field simulations we show that by placing the coils around the head of the subject, strong first-to-fourth order spherical harmonic shim fields can be generated very flexibly.