Magnetic field shimming adjustment: reducing magnetic distribution errors by obtaining current potential distributions of MRI apparatus

An apparatus configured for reducing an error magnetic component in a region of a magnetic field comprising:

• a magnetic field generating mechanism, by either:
• a magnetic field generation device, a superconducting magnet apparatus, a nuclear magnetic resonance tomographic apparatus, or an apparatus performing magnetic resonance imaging with which generates the magnetic field;
• a magnetic field adjustment mechanism in order to adjust the magnetic field, and which is either:
• a curved surface, or a flat surface that is configured for arranging a current loop, a ferromagnetic piece that is passively magnetized, or a permanent magnet, that is not dependent on an external magnetic field;
• and
• a computer configured to perform a magnetic field adjustment process including the steps of:
• measuring the magnetic field generated by either the magnetic field generation device, a superconducting magnet apparatus, a nuclear magnetic resonance tomographic apparatus, or an apparatus performing magnetic resonance imaging and measuring a plurality of nodes on a predetermined surface;
• calculating an error magnetic field that is a difference from the measured magnetic field and a target magnetic field;
• selecting one or more Eigen-distribution functions from among a plurality of Eigen-distribution functions that are obtained by singular value decomposition;
• obtaining a current potential distribution on a magnetic field adjustment mechanism in order to approximately correct the error magnetic field, according to the selected Eigen-distribution functions;
• converting the current potential distribution into magnetic moments at the nodes;
• and
• determining an arrangement of at least one of a current loop, a permanent magnet, or a ferromagnetic piece in accordance with the magnetic moments of the magnetic field adjustment mechanism.