Title :
Magnetic shielding for MRI superconducting magnets
Author :
Ishiyama, A. ; Hirooka, H.
Author_Institution :
Dept. of Electr. Eng., Waseda Univ., Tokyo, Japan
fDate :
3/1/1991 12:00:00 AM
Abstract :
An optical design is presented of a highly homogeneous superconducting coil system with magnetic shielding for magnetic resonance imaging (MRI). The optimal design method is a combination of the hybrid finite-element and boundary-element method for analysis of an axially symmetric nonlinear open-boundary magnetic field problem and a mathematical programming method for solving the corresponding optimization problem. The multiobjective goal programming method and the nonlinear least-squares method are adopted. The optimal design results of 1.5- and 4.7-T-magnet systems with different types of magnetic shielding for whole-body imaging are compared, and the advantages of a combination of active and yoke shields are shown
Keywords :
CAD; biomedical NMR; biomedical equipment; boundary-elements methods; electrical engineering computing; finite element analysis; least squares approximations; magnetic shielding; mathematical programming; superconducting magnets; 1.5 T; 4.7 T; MRI; active shields; axially symmetric problem; boundary-element method; highly homogeneous superconducting coil system; hybrid finite-element; magnetic shielding; mathematical programming; multiobjective goal programming method; nonlinear least-squares method; nonlinear open-boundary magnetic field problem; optical design; optimization problem; superconducting magnets; whole-body imaging; yoke shields; Design methodology; Design optimization; Finite element methods; Magnetic analysis; Magnetic resonance imaging; Magnetic shielding; Mathematical programming; Optical design; Superconducting coils; Superconducting magnets;
Journal_Title :
Magnetics, IEEE Transactions on
