Static magnetic field uniformity adjustment method, static magnetic field generator for magnetic resonance imaging, magnetic field adjustment system, program
In order to avoid duplication of time and cost required for magnetic field adjustment, minimize the magnetic field adjustment period at the final installation location, and increase the efficiency of magnetic field adjustment of the magnet, it was generated by a static magnetic field generating means in the measurement space A method of adjusting the uniformity of the static magnetic field by disposing a magnetic field correction unit that generates a correction magnetic field with respect to the static magnetic field includes a step of measuring the static magnetic field generated by the static magnetic field generation unit, and a measured static magnetic field. Performing a series expansion of the spatial distribution of the magnetic field, a first magnetic field adjustment step of correcting the irregular magnetic field component of the higher-order term among the irregular magnetic field components expanded in series, and after the first adjustment step, Adjusting a low-order irregular magnetic field component.磁場調整に要する期間ならびに費用の重複を避け、かつ最終設置場所における磁場調整期間の最小化を実現し、磁石の磁場調整の高効率化を図るために、計測空間に静磁場発生手段により発生した静磁場に対し、補正磁場を発生する磁場補正手段を配置して、前記静磁場の均一度を調整する方法は、前記静磁場発生手段が発生した静磁場を測定するステップと、測定された静磁場の空間分布を級数展開するステップと、級数展開された不整磁場成分のうち、高次項の不整磁場成分を補正する第一の磁場調整ステップと、前記第一の調整ステップの後に行われ、前記低次の不整磁場成分を調整する第二のステップと、を含む。
