US 11,733,329 B2
B0 shimming device for MRI
David Brunner, Jona (CH); Simon Gross, Zurich (CH); and Klaas Pruessmann, Zurich (CH)
Assigned to UNIVERSITAET ZUERICH, Zurich (CH); and ETH ZURICH, Zurich (CH)
Filed by ETH Zurich, Zurich (CH); and UNIVERSITAET ZUERICH, Zurich (CH)
Filed on Aug. 1, 2021, as Appl. No. 17/390,985.
Application 17/390,985 is a continuation of application No. 16/083,973, abandoned, previously published as PCT/EP2017/050862, filed on Jan. 17, 2017.
Claims priority of application No. 16151629 (EP), filed on Jan. 17, 2016.
Prior Publication US 2022/0018921 A1, Jan. 20, 2022
Int. Cl. G01R 33/3873 (2006.01); G01R 33/38 (2006.01); G01R 33/54 (2006.01)
CPC G01R 33/3873 (2013.01) [G01R 33/3804 (2013.01); G01R 33/543 (2013.01)] 21 Claims
OG exemplary drawing
 
1. A magnetic resonance (MR) apparatus comprising:
a) magnet for generating a main magnetic field in a sample region adapted for introduction of a sample or subject from which a MR signal is to be acquired;
b) wherein the apparatus is configured to superimpose encoding magnetic fields onto the main magnetic field;
c) RF transmitter configured to generate MR radiofrequency fields;
d) driver configured to operate said RF transmitter which is configured to generate radiofrequency fields according to a MR sequence for forming images or spectra and wherein superimposed time dependent encoding fields are generated as a result of operating the driver; and
e) wherein said magnet comprises 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′;
wherein said 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,
the apparatus further comprising at least three magnetic field probes configured to allow determination of an instant spatial distribution of the static magnetic field resulting from said static magnetic field B0 and said adjustable magnetic field B′.