Magnetic resonance imaging apparatus and method
US5296811A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 3, 1992 |
| Grant date | Mar 22, 1994 |
| Priority date | — |
| Expiry date | Nov 3, 2012 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01R33/28
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
The invention relates to a novel magnetic resonance imaging apparatus. The nuclei, protons or the paramagnetic electrons of an imaged object are cyclically polarized during a period of about one second with a permanent magnet which is then quickly shifted away from the imaged object in a permanent magnet carrier tube, so that the field of the permanent magnet would not have an interfering effect on the immediately following signal-collection for MRI-imaging. The permanent magnet can be manipulated or shifted back and forth in the tube either magnetically, pneumatically, hydraulically or mechanically. The apparatus also includes another permanent magnet or a resistive magnet coil couple, which is located in the tube near the opposite end of the tube, and which generates a homogeneous magnetic field within the imaged area. The apparatus includes a gradient coil system for generating a time-dependent magnetic field gradient necessary for imaging, as well as a coil system for producing an electromagnetic radio-frequency excitation signal to be linked with the nuclei or paramagnetic electrons of an imaged object as well as for registering the response of the nuclei or electrons to said …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.