Electricity: measuring and testing – Particle precession resonance – Spectrometer components
Reexamination Certificate
2007-07-10
2007-07-10
Shrivastav, Brij (Department: 2859)
Electricity: measuring and testing
Particle precession resonance
Spectrometer components
Reexamination Certificate
active
10555937
ABSTRACT:
The invention relates to a radio-frequent (RF) coil system (17, 17′) for use in a magnetic resonance imaging (MRI) system. The RF coil system comprises at least one main coil (35) for transmitting an RF magnetic field (B1) into and/or receiving an RF magnetic field (B1′) from an examination volume (3) of the MRI system. The main coil has a coil axis (36), which is or is to be oriented parallel to a main magnetic field (Bo) in the examination volume (3), and at least one electrical conductor (37, 39) which extends mainly parallel to the coil axis. According to the invention, the RF coil system comprises an auxiliary coil (45, 47) which is assigned to said conductor of the main coil. The auxiliary coil has two electrical conductors (49, 51) which extend mainly parallel to the coil axis and on opposite sides of said conductor of the main coil. A distance between the two conductors of the auxiliary coil and the conductor of the main coil is small relative to a main dimension (L) of the main coil. In transmission mode, RF signals are supplied to the main coil and to the auxiliary coil with such a mutual phase difference, that a combined RF magnetic field (Bc) of 15 the main coil and the auxiliary coil has a direction of rotation (RB) opposite to a direction of precession (Rp) of the spin axes of the spinning nuclei in a body to be examined. In receiving mode, a first RF signal received by the main coil and a second RF signal received by the auxiliary coil are combined and added at such a mutual phase difference, that the second RF signal suppresses the first RF signal. In this manner, the disadvantageous high local20sensitivity of the RF coil system for the local region (38, 40) adjoining said conductor of the main coil is strongly reduced.
REFERENCES:
patent: 3025456 (1962-03-01), Codrington
patent: 4816765 (1989-03-01), Boskamp
patent: 5602556 (1997-02-01), Bowers
patent: 6297636 (2001-10-01), Shimo et al.
patent: 6366092 (2002-04-01), Ehnholm et al.
patent: 6404201 (2002-06-01), Boskamp
patent: 6437567 (2002-08-01), Schenck et al.
patent: 0 364 061 (1990-04-01), None
patent: 1 037 068 (2000-09-01), None
Rath, A.R., et al.; A Spatially Selective Opoposed-Loop Surface Coil; 1988; J. Mag. Reson.; 79:461-473.
Burl, M., et al.; Examples of the Design of Screened and Shielded RF Receiver Coils; 1996; MRM, 36:326-330.
Koninklijke Philips Electronics , N.V.
Lundin Thomas M.
Shrivastav Brij
Vargas Dixomara
LandOfFree
RF surface coil for use in MRI with reduce sensitivity close... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with RF surface coil for use in MRI with reduce sensitivity close..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and RF surface coil for use in MRI with reduce sensitivity close... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3721303