Technique for driving quadrature dual frequency RF resonators for magnetic resonance spectroscopy/imaging by four-inductive loop over coupling
US5365173A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 18, 1993 |
| Grant date | Nov 15, 1994 |
| Priority date | — |
| Expiry date | Feb 18, 2013 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01R33/422
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
In a magnetic resonance system, four primary loop circuits (50, 52, 54, 56) are inductively coupled to a resonator coil (32) at 90.degree. intervals around its circumference. The loop circuits are over-coupled to the resonator coil, i.e. they present more than the characteristic resistance of the associated cabling system which causes the maximum current transfer between the loop circuits and the resonator coil to be offset (f.sub.N) in equal amounts in each direction from a natural resonance frequency (f.sub.0) of the resonator coil. In one embodiment, two adjacent primary loop circuits provide for quadrature radio frequency transmission to and from the resonator coil at a first frequency and the other two primary loop circuits provide for quadrature radio frequency transmission to and from the resonator coil at a second resonance frequency. Each of the primary loop circuits includes a tank circuit (62) for blocking the passage of the frequency of the other quadrature primary loop circuit pair. In another embodiment, the third and fourth primary loop circuits are connected with tuning capacitors for adjusting the resonance frequency of the resonator coil relative to radio frequenc…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.