Patent ID: 7459908
Filing Date: 2008-12-02
Classification: G01R

Abstract:
1. Method of providing shim sheets for adjusting a magnetic field in a magnetic resonance device by passive shimming, comprising the steps of: field mapping of a region of interest in the MR device for obtaining an uncorrected magnetic field distribution including field inhomogeneities, decomposing the field inhomogeneities into first and second order spherical harmonic functions, determining primary shim terms derived from the second order spherical harmonic functions, wherein the primary shim terms yield a passive shim field adapted to a targeted shim field, scaling optimized shim terms for increasing a similarity of the passive shim field with the targeted shim field, constructing modular shim sheets on the basis of the optimized shim terms, and mounting the modular shim sheets on a shim sheet carrier.