Method for shimming a magnetic field which is generated by a magnetic structure, and which permeates a volume of space uses the following steps: measuring the magnetic field in a region of a volume of space permeated by the said magnetic field; determining a parameter which is a measure of the homogeneity of the magnetic field; defining a distribution of correction elements including a predetermined number of magnetic dipoles each having a predetermined magnetic charge and a predetermined position relatively to the magnetic structure generating the magnetic field; calculating the charges of each of the dipoles and the position of each of the dipoles of a distribution which minimizes the parameter being a measure of the homogeneity of the magnetic field; using the distribution of dipoles as the shimming distribution of dipoles to be positioned on the magnetic structure.

Method for shimming a magnetic field which is generated by a magnetic structure, and which permeates a volume of space uses the following steps: measuring the magnetic field in a region of a volume of space permeated by the said magnetic field; determining a parameter which is a measure of the homogeneity of the magnetic field; defining a distribution of correction elements including a predetermined number of magnetic dipoles each having a predetermined magnetic charge and a predetermined position relatively to the magnetic structure generating the magnetic field; calculating the charges of each of the dipoles and the position of each of the dipoles of a distribution which minimizes the parameter being a measure of the homogeneity of the magnetic field; using the distribution of dipoles as the shimming distribution of dipoles to be positioned on the magnetic structure.

The present disclosure may provide a magnetic resonance (MR) system. The MR system may include a magnet assembly, a gradient coil assembly, and a shim assembly. The magnet assembly may be configured to generate a main magnetic field. The magnet assembly may include a magnet and a cryostat configured to cool the magnet located inside the cryostat. The cryostat may form a bore. The gradient coil assembly may be configured to generate a gradient magnetic field. The gradient coil assembly may be located inside the bore. The shim assembly may be configured to at least partially shield a stray field which is generated by the gradient coil assembly and to which the magnet is subjected. The shim assembly may be located outside the gradient coil assembly.

The present disclosure may provide a magnetic resonance (MR) system. The MR system may include a magnet assembly, a gradient coil assembly, and a shim assembly. The magnet assembly may be configured to generate a main magnetic field. The magnet assembly may include a magnet and a cryostat configured to cool the magnet located inside the cryostat. The cryostat may form a bore. The gradient coil assembly may be configured to generate a gradient magnetic field. The gradient coil assembly may be located inside the bore. The shim assembly may be configured to at least partially shield a stray field which is generated by the gradient coil assembly and to which the magnet is subjected. The shim assembly may be located outside the gradient coil assembly.

A fastening device for releasably fastening a probe (1) to an NMR magnet (2). An insert part (3) fastens the probe to a retaining system (4) connected to the magnet. A force-variable connection is established by the insert part with spring elements (8). The probe fastens to the insert part with rigid retaining elements (6). When closed, a connection without mechanical play exists between the insert part and the retaining elements when the spring elements are under tension. An annular disc-shaped pretensioning element (9) is arranged between the insert part and the retaining system. By rotating the pretensioning element relative to the insert part, the pretensioning element presses on and pretensions the spring elements. When open, the spring elements and the retaining elements are configured to connect with a mechanical play of 0.5 to 5 mm between the insert part and the retaining elements when the spring elements are pretensioned.

A fastening device for releasably fastening a probe (1) to an NMR magnet (2). An insert part (3) fastens the probe to a retaining system (4) connected to the magnet. A force-variable connection is established by the insert part with spring elements (8). The probe fastens to the insert part with rigid retaining elements (6). When closed, a connection without mechanical play exists between the insert part and the retaining elements when the spring elements are under tension. An annular disc-shaped pretensioning element (9) is arranged between the insert part and the retaining system. By rotating the pretensioning element relative to the insert part, the pretensioning element presses on and pretensions the spring elements. When open, the spring elements and the retaining elements are configured to connect with a mechanical play of 0.5 to 5 mm between the insert part and the retaining elements when the spring elements are pretensioned.

A homogenization device for homogenization of a magnetic field with an non-magnetic carrier and compensation elements formed of a magnetic material, the carrier having a carrier wall and the carrier wall surrounding a carrier interior, in the homogenization device located in the magnetic field the magnetic field penetrating into the carrier interior through a first carrier region of the carrier wall and emerging from the carrier interior through a second carrier region of the carrier wall and each of the compensation elements which are located on the carrier contributing to the homogenization of the magnetic field at least in the carrier interior. In the homogenization device, handling during homogenization is improved in that there are recesses in the carrier wall and in each of the recesses at least one of the compensation elements can be directly inserted and removed.

A homogenization device for homogenization of a magnetic field with an non-magnetic carrier and compensation elements formed of a magnetic material, the carrier having a carrier wall and the carrier wall surrounding a carrier interior, in the homogenization device located in the magnetic field the magnetic field penetrating into the carrier interior through a first carrier region of the carrier wall and emerging from the carrier interior through a second carrier region of the carrier wall and each of the compensation elements which are located on the carrier contributing to the homogenization of the magnetic field at least in the carrier interior. In the homogenization device, handling during homogenization is improved in that there are recesses in the carrier wall and in each of the recesses at least one of the compensation elements can be directly inserted and removed.

In order to provide a static magnetic field homogeneity adjustment method capable of reducing an arrangement amount of magnetic pieces and achieving desired magnetic field homogeneity with high accuracy in magnetic field homogeneity adjustment, there is provided a static magnetic field homogeneity adjustment method in an imaging space of computing positions of a plurality of magnetic pieces separated from the imaging space through shimming computation with respect to a static magnetic field in the imaging space generated by a magnetic field generation device, and disposing the plurality of magnetic pieces at the positions obtained through the shimming computation, the method including an adjustment step of imposing restriction that a polarity of a magnetic field distribution generated in the imaging space by the magnetic pieces disposed at the positions is either positive or negative during the shimming computation, and adjusting the static magnetic field homogeneity.

In order to provide a static magnetic field homogeneity adjustment method capable of reducing an arrangement amount of magnetic pieces and achieving desired magnetic field homogeneity with high accuracy in magnetic field homogeneity adjustment, there is provided a static magnetic field homogeneity adjustment method in an imaging space of computing positions of a plurality of magnetic pieces separated from the imaging space through shimming computation with respect to a static magnetic field in the imaging space generated by a magnetic field generation device, and disposing the plurality of magnetic pieces at the positions obtained through the shimming computation, the method including an adjustment step of imposing restriction that a polarity of a magnetic field distribution generated in the imaging space by the magnetic pieces disposed at the positions is either positive or negative during the shimming computation, and adjusting the static magnetic field homogeneity.