Method of magnetic field controlled shimming
US6819108B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 9, 2003 |
| Grant date | Nov 16, 2004 |
| Priority date | — |
| Expiry date | Jul 5, 2023 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01R33/3875
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
The present invention is directed to a method of shimming a magnet assembly of an MR imaging system such that a desired B0 field strength may be created with minimal inhomogeneities therethrough. With this method, sufficient shimming of the magnet assembly may be achieved without requiring mechanical variations to the magnet assembly after the magnet assembly has been assembled. The invention analyzes variations from the desired B0 field and inhomogeneities at a number of target points along the magnet assembly or B0 field. A comparison is then made at each point to determine a shimming or weighting factor such that the desired overall B0 field strength and targeted field homogeneity is achieved. Active and/or passive shim elements may then be incorporated into the magnet assembly at each target point to achieve the desired overall field strength and minimum overall field homogeneity.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.