PROBLEM TO BE SOLVED: To provide a magnetic resonance imaging apparatus 1 for highly accurately and uniformly adjusting the magnetic field of a uniform magnetic field space 3 by arranging shims 6c even when the shape of an opening, in which a subject is carried, is not a circular shape.SOLUTION: The magnetic resonance imaging apparatus includes: a magnet device 2 having a cylindrical outer shape and generating the uniform magnetic field space 3 inside the cylindrical shape and a magnetic field adjusting means 6 for arranging the shims 6c made of a magnetic material on a shim arrangement curved surface C1 inside the cylindrical shape to uniform the magnetic field of the uniform magnetic field space 3. The shape of a cross-section on a plane perpendicular to the axis z of the shim arrangement curved surface C1 is not a circular shape. A distance between the shim arrangement curved surface C1 and the axis z on the plane varies depending on places on the shim arrangement curved surface C1. There are places with the large distances and the places with the distances smaller than that of the places with the large distances. Intervals between the shims 6c adjacent in the peripheral direction of the axis z at the places with the large distances are wider than intervals at the places with the smaller distances.COPYRIGHT: (C)2013,JPO&INPIT【課題】被検体が搬入される開口部の形状が非円形であっても、シム6cを配置することによって、均一磁場空間3の磁場を高精度に均一に調整可能な磁気共鳴撮像装置1を提供する。【解決手段】筒状の外観形状を有しその筒状の内側に均一磁場空間3を生成する磁石装置2と、磁性材のシム6cを筒状の内側のシム配置曲面C1上に配置し均一磁場空間3の磁場をより均一にする磁場調整手段6とを備え、シム配置曲面C1の中心軸zに垂直な平面での断面上の形状は非円形であり、その平面上におけるシム配置曲面C1と中心軸zとの距離が、シム配置曲面C1上の箇所によって異なり、その距離が大きい箇所と前記大きい箇所より小さい箇所があり、その距離が大きい箇所での中心軸zの周方向に隣り合うシム6c同士の間隔が、その距離が小さい箇所での間隔より広くなっている。【選択図】図1A
