Double-sided RF shield for RF coil contained within gradient coils of NMR imaging device
US4879515A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 22, 1988 |
| Grant date | Nov 7, 1989 |
| Priority date | — |
| Expiry date | Dec 22, 2008 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01R33/422
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A double-sided RF shield, for use between a set of gradient coils and an RF coil, is a hollow member formed of a conductor-dielectric-conductor laminate. Each conductor is a sheet divided into first and second opposed half-cylinders, each having a plurality of conductive streamline loop portions with a series of nonconductive cut lines formed therebetween, with each of the cut lines being parallel to the RF current. Each of the loops is separated into a "C"-shaped conductive portion along at least one "radial" line cut in each half-cylinder. The cut lines are substantially opposite to one another on opposite surfaces of the half-cylinders, to form a loop with a pair of series capacitances of maximized value, which shield the RF current, yet pass gradient magnetic fields in all three mutually orthogonal directions of a Cartesian coordinate system.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.