Patent ID: 8354845

Claim:
A method for examination subject-specific determination of parameters for activating gradient coils and radio-frequency coils of a coil array of a magnetic resonance apparatus, comprising the steps of: from a control unit, activating amplitudes and phases of currents in radio-frequency coils and respective currents in gradient coils of a magnetic resonance system in a time-dependent manner in discrete time steps to generate gradient fields and a radio-frequency pulse that move nuclear spins in an examination region of an examination subject in the magnetic resonance system out of a rest state by an arbitrary angle; in a processor in communication with said control unit, automatically calculating parameters in order to activate said radio-frequency coils and said gradient coils dependent on measured sensitivity maps of the radio-frequency coils at the examination subject by implementing a numerical calculation in the processor; in said numerical calculation in said processor, optimizing a non-linear equation system arg b min{∥M theor −M desired ∥} wherein M desired represents a desired magnetization in the examination subject and M theror represents a theoretical, calculated real magnetization in the examination subject; and in said processor, calculating the Jacobians matrix of said real magnetization in the optimization of said non-linear equation system dependent on a direction of decline of said magnetization, to generate matrix elements of said Jacobian matrix consisting of products of individual rotations that are determined from the optimized parameters and, for each matrix element, calculating only factors for which a corresponding parameter is associated within a time step represented by the matrix element.