According to one embodiment, a magnetic field adjustment implement for a magnetic resonance imaging apparatus includes a magnetic field adjustment unit and a placing unit. The magnetic field adjustment unit is configured to improve a uniformity of a static magnetic field formed by a magnet of the magnetic resonance imaging apparatus. The static magnetic field is formed under an influence of a circumstance in a shield room in which the magnet is placed. The magnetic field adjustment is placed outside the magnet. The placing unit is configured to place the magnetic field adjustment unit outside the magnet.

According to one embodiment, a magnetic field adjustment implement for a magnetic resonance imaging apparatus includes a magnetic field adjustment unit and a placing unit. The magnetic field adjustment unit is configured to improve a uniformity of a static magnetic field formed by a magnet of the magnetic resonance imaging apparatus. The static magnetic field is formed under an influence of a circumstance in a shield room in which the magnet is placed. The magnetic field adjustment is placed outside the magnet. The placing unit is configured to place the magnetic field adjustment unit outside the magnet.

A superconducting magnet coil arrangement has a high-temperature superconductor (HTS) coil section (1a,1b,1c) in the form of a solenoid that is wound with an HTS tape conductor, and also has a field-shaping device comprising at least two field-shaping elements (2a,2b,2c). At least one respective field-shaping element is arranged adjoining each of the two axial ends of the HTS coil section, the field-shaping elements being configured in such a way that they reduce the field angle of the magnetic field generated by the magnet coil arrangement with respect to the axial direction in the region of the HTS coil section by at least 1.5°.

A superconducting magnet coil arrangement has a high-temperature superconductor (HTS) coil section (1a,1b,1c) in the form of a solenoid that is wound with an HTS tape conductor, and also has a field-shaping device comprising at least two field-shaping elements (2a,2b,2c). At least one respective field-shaping element is arranged adjoining each of the two axial ends of the HTS coil section, the field-shaping elements being configured in such a way that they reduce the field angle of the magnetic field generated by the magnet coil arrangement with respect to the axial direction in the region of the HTS coil section by at least 1.5°.

Methods and apparatuses for homogenizing or correcting the magnetic fields of magnets, particularly the magnetic fields employed in nuclear magnetic resonance (NMR) and magnetic resonance imaging (MRI) applications. There are disclosed passive shims for making such homogenizations or corrections, methods for making such shims, and a method and apparatus for creating desirable correction fields in which the correction field strength has limited harmonic content, near continuous value of field strength, and occupies minimal space in the magnet.

Methods and apparatuses for homogenizing or correcting the magnetic fields of magnets, particularly the magnetic fields employed in nuclear magnetic resonance (NMR) and magnetic resonance imaging (MRI) applications. There are disclosed passive shims for making such homogenizations or corrections, methods for making such shims, and a method and apparatus for creating desirable correction fields in which the correction field strength has limited harmonic content, near continuous value of field strength, and occupies minimal space in the magnet.

An arrangement for shimming a background magnetic field of a magnetic resonance imaging apparatus having an outer vacuum chamber (OVC) bore tube (1). Rails (8, 9) are provided on the OVC bore tube and shim trays (4) are mounted between respective rails.

An arrangement for shimming a background magnetic field of a magnetic resonance imaging apparatus having an outer vacuum chamber (OVC) bore tube (1). Rails (8, 9) are provided on the OVC bore tube and shim trays (4) are mounted between respective rails.

A passive magnetic field shim arrangement including a plurality of shim pairs. For shimming a number of magnetic field harmonics, each shim pair may include a first shim and a second opposite and substantially equal shim, each shim pair being configured for shimming one of the magnetic field harmonics. Each shim pair may include a first shim of order N and a second opposite and substantially equal shim of order N, the first and second shims together defining a magnetic field shim correction of order N−1. Each shim may include one or more shim elements arranged on a non-magnetic tubular support, the tubular supports being dimensioned such that the tubular supports may be arranged concentrically in relation to each other. A magnetic field may be shimmed by providing a shim pair configured for shimming a magnetic field harmonic, the shim pair including a first shim and a second opposite and substantially equal shim and symmetrically adjusting an axial position of the first shim and an axial position of the second shim to provide a desired shimming magnitude in order to shim the magnetic field harmonic.

A passive magnetic field shim arrangement including a plurality of shim pairs. For shimming a number of magnetic field harmonics, each shim pair may include a first shim and a second opposite and substantially equal shim, each shim pair being configured for shimming one of the magnetic field harmonics. Each shim pair may include a first shim of order N and a second opposite and substantially equal shim of order N, the first and second shims together defining a magnetic field shim correction of order N−1. Each shim may include one or more shim elements arranged on a non-magnetic tubular support, the tubular supports being dimensioned such that the tubular supports may be arranged concentrically in relation to each other. A magnetic field may be shimmed by providing a shim pair configured for shimming a magnetic field harmonic, the shim pair including a first shim and a second opposite and substantially equal shim and symmetrically adjusting an axial position of the first shim and an axial position of the second shim to provide a desired shimming magnitude in order to shim the magnetic field harmonic.