Patent ID: 7242192

Claim:
A radio-frequent (RF) coil system for use in a magnetic resonance imaging (MRI) system, comprising at least one electrical main coil for transmitting an RF magnetic field into an examination volume of the MRI system for generating nuclear spin resonance effects with a predetermined direction of precession, said main coil having a coil axis which is to be oriented substantially parallel to a main magnetic field of the MRI system in the examination volume, said main coil having at least one electrical conductor extending mainly parallel to the coil axis, wherein the RF coil system comprises an electrical auxiliary coil assigned to said conductor of the main coil and having at least two electrical conductors extending mainly parallel to the coil axis, said two conductors of the auxiliary coil being arranged on opposite sides of and at a distance from said conductor of the main coil, wherein said distance is small relative to a main dimension of the main coil, the RF coil system comprising means for supplying RF signals to the main coil and to the auxiliary coil at such a mutual phase difference that, in a local region adjoining the conductor of the main coil, a combined RF magnetic field of the main coil and the auxiliary coil has a direction of rotation opposite to the direction of precession and wherein the main coil has a loop comprising a first and a second electrical conductor extending substantially parallel to the coil axis, the RF coil system having a first and a second auxiliary coil assigned to, respectively, said first and said second conductor of the main coil, each auxiliary coil having at least two electrical conductors extending substantially parallel to the coil axis, the two conductors of each auxiliary coil being arranged on opposite sides of and at a distance from the respective conductor of the main coil, wherein said distance is small relative to a main dimension of the main coil and wherein a distance B between the two conductors of each auxiliary coil is smaller than 0.25*L, wherein L is a distance between the first and the second conductor of the main coil.