A method for determining a with shim means to be passive correction of an inhomogeneity of an arc as c - a magnetic resonance tomograph and coil apparatus, adapted for use in the method

摘要

A method for determining a with shim means to be passive correction of an inhomogeneity of a magnetic resonance tomograph, which is designed as a c - sheet, comprising the steps of:– Arranging at least one individually controllable coils (3) comprising a coil apparatus (1, 5) in the region of a magnetic pole of a basic field magnet (6) of the magnetic resonance tomograph,– Introduction of a means (7) for measuring the magnetic field of the main field magnet (6) in a central magnetic field range,– Determination of the field strength distribution and a passive correction to be carried out as a function of the measuring result,– Control of the coil apparatus (1, 5) in dependence on for the individual coils (3) of the passive correction certain control currents and– renewed determination of the field strength distribution and a, for further reduction of the inhomogeneity of the passive correction in the control currents applied to be undertaken.