Patent ID: 9638776
Date: 2017-05-02
CPC Classifications: G01R

Claim:
1. A nested shim coil assembly for shimming the magnetic field of a magnetic resonance system by generating spherical harmonics of a sine type and a cosine type of the magnetic field in order to compensate radial harmonics, the nested shim coil assembly comprising a plurality of saddle-shape coils each having electrical connections, said saddle-shape coils configured in pairs to define at least a first set of saddle-shape coils and a second set of saddle-shape coils, wherein the first set of saddle-shape coils shim a field with a first degree order and a first degree index, and having a first azimuthal span, and the second set of saddle-shape coils shim a second order and a second degree index, and having a second azimuthal span, wherein the first set of saddle-shape coils are nested within the second set of saddle-shape coils to occupy a reduced radial space; wherein the first azimuthal span is less than the second azimuthal span, and wherein the combination of the first order and the first degree index are different from the second order and the second degree index, and the first set of saddle-shape coils and the second set of saddle-shape coils are combined together in the same radial assembly; and wherein the first set of saddle-shape coils has a first direction of current and the second set of saddle-shape coils has a second direction of current non-identical to the first direction of current.