Surface coils with integrated shims
US6023167A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 26, 1998 |
| Grant date | Feb 8, 2000 |
| Priority date | — |
| Expiry date | Jan 26, 2018 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01R33/3875
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A localized shim coil (34) for use in a magnetic resonance imaging system includes a plurality of conductive elements (22a-d). The plurality of conductive elements (62a-d) are connected to a current source (64). The plurality of conductive elements (62a-d) are arranged adjacent to a localized region of a subject being imaged such that current flowing through the conductive elements generates a localized magnetic field. A plurality of series connected choke and resister pairs (66a-d) and (68a-d), respectively, are connected to the plurality of conductive elements (62a-d). The chokes (66a-d) present high impedance to currents having frequencies substantially the same as a resonant frequency of the magnetic resonance imaging system. The resisters (68a-d) balance the current flowing through each conductive element (62a-d). The localized magnetic field is generated such that it is substantially equal and opposite to localized non-uniformities generated in the magnetic resonance system's main magnetic field by the subject's geometric shape and magnetic susceptibility in the localized region being imaged.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.