Magnetic resonance imaging magnet having minimally symmetric ferromagnetic shield
US4931759A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 6, 1989 |
| Grant date | Jun 5, 1990 |
| Priority date | — |
| Expiry date | Apr 6, 2009 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01R33/3873
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A magnetic resonance imaging magnet has a solenoidal superconducting winding producing a magnetic field and defining an examination region within a bore thereof. The examination region receives a body to be examined. The solenoidal superconducting winding generates a quasi-static magnetic field for aligning atomic nuclei in the body being examined. A two-fold or minimally symmetric ferromagnetic shield has a pair of magnetic flux return paths positioned on opposite sides of the solenoidal superconducting winding for reducing the magnetic field intensity in a region proximate to and outside of the solenoidal superconducting winding. A magnetic field inhomogeneity compensating system reduces magnetic field inhomogeneities introduced into the magnetic field within the examination region by the minimally symmetric ferromagnetic shield to provide a highly uniform quasi-static magnetic field within the examination region.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.