US 11,959,985 B2
Static-magnetic-field shimming coil system for magnetic resonance imaging
Bruno Pinho-Meneses, Gif-sur-Yvette (FR); and Alexis Amadon, Gif-sur-Yvette (FR)
Assigned to COMMISSARIAT A L'ENERGIE ATOMIQUE ET AUX ENERGIES ALTERNATIVES, Paris (FR)
Appl. No. 17/603,915
Filed by COMMISSARIAT A L'ENERGIE ATOMIQUE ET AUX ENERGIES ALTERNATIVES, Paris (FR)
PCT Filed Apr. 16, 2020, PCT No. PCT/EP2020/060649
§ 371(c)(1), (2) Date Oct. 14, 2021,
PCT Pub. No. WO2020/212463, PCT Pub. Date Oct. 22, 2020.
Claims priority of application No. 19315024 (EP), filed on Apr. 19, 2019.
Prior Publication US 2022/0236350 A1, Jul. 28, 2022
Int. Cl. G01R 33/3875 (2006.01)
CPC G01R 33/3875 (2013.01) 19 Claims
OG exemplary drawing
 
1. A method of designing a static-magnetic-field shimming coil system (SCS) for magnetic resonance imaging, comprising the steps of:
a) for each member of a cohort of magnetic resonance imaging subjects (S1, S2, S3):
a1) acquiring a map of a static magnetic field (FM1, FM2, FM3) within a region of interest (ROI), common to all members, comprising a bodily portion (HH) of the member;
a2) determining a corrective static magnetic field such that a sum of the acquired static magnetic field and the corrective static magnetic field is equal to a target static magnetic field within the region of interest;
a3) determining a stream function (I, I1, I2, I3, I4), defined on a reference surface (RS, RS1) enclosing the region of interest (ROI) and corresponding to a current density distribution on said surface, minimizing either a cost function representative at least of a difference between the corrective static magnetic field and a static magnetic field generated by said current density distribution, or a cost function representative at least of an electric parameter of the coil system subject to at least one constraint representative of said difference;
b) performing a Principal Component Analysis of the stream functions determined for at least a plurality of members of the cohort; and
c) determining at least one coil wiring pattern (WP1) defined on said reference surface (RS1) by discretizing at least a most significant principal component (I1SVD) of said stream functions;
steps a2), a3), b) and c) being carried out using a computer.