MRI apparatus with high-resistance magnet
US7352184B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 20, 2006 |
| Grant date | Apr 1, 2008 |
| Priority date | — |
| Expiry date | Dec 20, 2026 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/12014
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Eddy current generated around a magnetic circuit in an MRI apparatus is one of the causes of deviation from an ideal magnetic field gradient waveform and causes image distortion, loss of strength, ghost generation, loss of signal, and spectral distortion. An object of the present invention is to suppress the generation of the eddy current. In an MRI apparatus, a ferromagnetic material formed from powder is used in a part of a magnetic circuit: the powder mainly comprising a mother phase containing iron or cobalt and showing ferromagnetism; and a high-resistance layer having a resistance not less than ten times as high as the mother phase and a Vickers hardness lower than that of the mother phase being formed in layers along parts of the surface of the powder on parts or the entire of the surface.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.