Patent ID: 8035387
Filing Date: 2011-10-11
Classification: G01R

Abstract:
1. A method of determining locations at which at least two magnetic articles are to be positioned during a magnetic resonance imaging procedure of at least one subject, the method comprising: A) using a magnetic resonance imaging system, applying a magnetic field B B) receiving first magnetic resonance information about the region in response to the applied magnetic field B C) determining, based at least in part on the first magnetic resonance information, at least one first location proximate the at least one subject at which at least one paramagnetic article is to be positioned so as to at least partially compensate for the one or more magnetic field inhomogeneities; D) determining, based at least in part on the first magnetic resonance information, at least one second location proximate the at least one subject at which at least one diamagnetic article is to be positioned so as to at least partially compensate for the one or more magnetic field inhomogeneities; E) prior to steps C) and D), determining a plurality of magnetic induction fields U induced in the region by a plurality of reference magnetic articles each having a reference magnetic susceptibility, the plurality of reference magnetic articles being placed at a plurality of different positions N proximate to the at least one subject, wherein the steps C) and D) are performed based at least in part on the first magnetic resonance information and the plurality of magnetic induction fields U; F) determining inhomogeneous magnetic field information T by comparing the static magnetic field B G) determining, for the plurality of different positions N proximate to the at least one subject, a plurality of scaling values η which, when respectively multiplied by the reference magnetic susceptibility, represent a plurality of actual magnetic susceptibilities at the plurality of different positions N that facilitate compensation of the one or more magnetic field inhomogeneities, wherein i is a first index, j is a second index, M is a number of positions r within the region, and determining the plurality of scaling values comprises finding η that minimizes