A method for obtaining an image by magnetic resonance imaging using a magnetic resonance imaging apparatus comprising: a magnet defining an imaging volume arranged such that a part of a patient is during imaging positioned in the volume so as to lie in the magnetic field of the magnet; a radio frequency transmission and detection system for eliciting and detecting from the part of the patient nuclear magnetic resonance signals, in response to the magnetic field; a control system for receiving the nuclear magnetic resonance signals for generating an image therefrom; a plurality of shimming coils mounted at the magnet so as to generate shimming fields which increase the homogeneity of the magnetic field within the imaging volume; the control system having an input for entering a set of shimming parameters of the shimming coils; the magnet with the shimming coils being movable so as to move the imaging volume between a plurality of different positions in which imaging can be carried out and a position input system for inputting into the control system an indication of a currently selected position of the imaging volume from the plurality of different positions of the imaging volume; the method comprising: defining a plurality of different rooms (41,42) in which the magnet is moved and used for imaging and wherein the plurality of different positions of the imaging volume are obtained by moving the magnet into the different rooms (41,42) with each room (41,42) defining a respective one of the positions; using a shim rig to predetermine the required shimming parameters in each position and storing these shimming parameters in association with the location parameters in the control system, the control system applying to the shimming coils the required set of shimming parameters. a magnet defining an imaging volume arranged such that a part of a patient is during imaging positioned in the volume so as to lie in the magnetic field of the magnet; a radio frequency transmission and detection system for eliciting and detecting from the part of the patient nuclear magnetic resonance signals, in response to the magnetic field; a control system for receiving the nuclear magnetic resonance signals for generating an image therefrom; a plurality of shimming coils mounted at the magnet so as to generate shimming fields which increase the homogeneity of the magnetic field within the imaging volume; the control system having an input for entering a set of shimming parameters of the shimming coils; the magnet with the shimming coils being movable so as to move the imaging volume between a plurality of different positions in which imaging can be carried out and a position input system for inputting into the control system an indication of a currently selected position of the imaging volume from the plurality of different positions of the imaging volume; the method comprising: defining a plurality of different rooms (41,42) in which the magnet is moved and used for imaging and wherein the plurality of different positions of the imaging volume are obtained by moving the magnet into the different rooms (41,42) with each room (41,42) defining a respective one of the positions; using a shim rig to predetermine the required shimming parameters in each position and storing these shimming parameters in association with the location parameters in the control system, the control system applying to the shimming coils the required set of shimming parameters. defining a plurality of different rooms (41,42) in which the magnet is moved and used for imaging and wherein the plurality of different positions of the imaging volume are obtained by moving the magnet into the different rooms (41,42) with each room (41,42) defining a respective one of the positions; using a shim rig to predetermine the required shimming parameters in each position and storing these shimming parameters in association with the location parameters in the control system, the control system applying to the shimming coils the required set of shimming parameters.