In a magnetic resonance imaging apparatus and a method for shimming such
an apparatus, at each of mirror-symmetrical assemblies respectively
disposed at opposite faces of a static magnetic field generator, that
each include a shimming ring, an additional shimming ring is provided
that is adjustable in position relative to the other shimming ring to
shim the static magnetic field. Additionally or alternatively, at each
face of the static magnetic field generator, a permanently magnetic
arrangement is provided that is divided into a number of permanently
magnetic columns respectively having different energy levels.
Additionally or alternatively, magnetic bolts, such as magnetically
conducting bolts or permanently magnetic bolts can be symmetrically
inserted into either of the mirror-symmetric assemblies, or the
permanently magnetic columns, for additionally shimming adjustment.