Method and magnetic resonance apparatus for setting a shim to homogenize a magnetic field in the apparatus

A magnetic resonance apparatus comprising:

• a basic field magnet that generates a basic magnetic field to assist in acquiring magnetic resonance exposures of a predetermined examination;
• a shim arrangement that homogenizes said basic magnetic field;
• a computer that at least semi-automatically designates a three-dimensional volume that is relevant for setting said shim arrangement for acquiring magnetic resonance data from the examination region using an examination protocol, said computer at least automatically setting said three-dimensional volume matched to at least one of said examination region and said examination protocol by selecting said three-dimensional volume from a plurality of arbitrary morphology sets of selectable volumes, not limited to specific volume shapes, or by generating said three-dimensional volume as an arbitrary three-dimensional volume not limited to a specific volume shape;
• and
• said computer automatically calculating values for setting said shim arrangement for said three-dimensional volume that has been at least semi-automatically designated, and making the calculated values available as an output from the computer in a form for setting said shim arrangement in said magnetic resonance apparatus.