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    B
    4.
    发明授权
    B 有权

    公开(公告)号：US11733329B2

    公开(公告)日：2023-08-22

    申请号：US17390985

    申请日：2021-08-01

    申请人： ETH Zurich ,  UNIVERSITAET ZUERICH

    发明人： David Brunner ,  Simon Gross ,  Klaas Pruessmann

    IPC分类号： G01R33/3873 ,  G01R33/38 ,  G01R33/54

    CPC分类号： G01R33/3873 ,  G01R33/3804 ,  G01R33/543

    摘要： A magnetic resonance (MR) apparatus comprises magnet means for generating a main magnetic field in a sample region, encoding means for generating encoding magnetic fields superimposed to the main magnetic field, RF transmitter means for generating MR radiofrequency fields, driver means for operating said encoding means and RF transmitter means to generate superimposed time dependent encoding fields and radiofrequency fields according to an MR sequence for forming images or spectra; and acquisition means for acquiring an MR signal from said object. The magnet means comprise a primary magnetic field source providing a static magnetic field B0 and at least one secondary magnetic field source providing an adjustable magnetic field B′. To provide improved shimming, the secondary magnetic field source comprises at least two spatially distinct portions of a first magnetic material and of a second magnetic material, respectively, said first magnetic material having a first magnetic moment density m1 and said second magnetic material having a second magnetic moment density m2, and means for independently adjusting said second magnetic moment density m2 by variation of an external control parameter.

    Methods and systems for correcting B0 field in MRI imaging using shim coils
    8.
    发明授权
    Methods and systems for correcting B0 field in MRI imaging using shim coils 有权

    公开(公告)号：US09891299B1

    公开(公告)日：2018-02-13

    申请号：US14281431

    申请日：2014-05-19

    申请人： General Electric Company

    发明人： Robert Steven Stormont

    IPC分类号： G01R33/38 ,  G01R33/3873 ,  G01R33/58 ,  G01R33/385

    CPC分类号： G01R33/3873 ,  G01R33/34007 ,  G01R33/385 ,  G01R33/3875 ,  G01R33/58

    摘要： A magnetic resonance imaging (MRI) system includes a plurality of radio frequency (RF) coils configured to produce a static B0 field having non-homogeneous characteristics. The MRI system includes an RF transceiver configured to acquire MR imaging data from the RF coils for an area of interest. The system includes a DC source coupled to at least one of the RF coils to form a shimming RF coil, the DC source configured to force a select DC current through the shimming RF coil to at least partially shim the non-homogeneous characteristics of the B0 field. The shimming RF coil includes first and second conductors that exhibit distributed capacitance along a length thereof. At least one of the first and second conductors have first and second termination ends with an elongated and continuous conductive path therebetween to convey the select DC current from the DC source through the shimming RF coil.