A magnetic resonance imaging apparatus comprising: a radio frequency coil system for generating radio frequency excitation pulses for exciting magnetic resonance signals in an examination region of an imaging subject, said radio frequency coil system including N coil elements each being arranged to generate magnetic and electric fields in the examination region, where N is a plural number; a transmitting system including a plurality of transmitting channels (52 1, 52 2,... 52 n) each coupled to one or more of the N coil elements and arranged to inject RF excitation pulses into the examination region, the plurality of transmitting channels being arranged to individually control the amplitude and phase of input signals supplied to the coil elements, a weight setting device arranged to set weight factors for the input signals supplied to the coil elements, thereby adjusting the amplitude of the current induced in each coil element by the transmitting system; the transmitting system being arranged to create at least two sets of RF excitation pulses with differently weighted input signals, and to transmit the at least two sets of RF excitation pulses to the coil elements, the weight factors of the at least two sets of RF excitation pulses being selected such that, when the input signals are supplied to the N coil elements, the spatial locations at which the total electric field generated by the RF excitation pulses of each of the at least two sets of RF excitation pulses is negligible are spatially shifted from each other; and an image processor arranged to compute an electric permittivity map from magnetic resonance signals induced by each of the at least two sets of RF excitation pulses, wherein the image processor is further arranged to combine the computed permittivity maps to generate a corrected permittivity map corrected for regions in which said total electric field is near zero in one of said permittivity maps. a radio frequency coil system for generating radio frequency excitation pulses for exciting magnetic resonance signals in an examination region of an imaging subject, said radio frequency coil system including N coil elements each being arranged to generate magnetic and electric fields in the examination region, where N is a plural number; a transmitting system including a plurality of transmitting channels (52 1, 52 2,... 52 n) each coupled to one or more of the N coil elements and arranged to inject RF excitation pulses into the examination region, the plurality of transmitting channels being arranged to individually control the amplitude and phase of input signals supplied to the coil elements, a weight setting device arranged to set weight factors for the input signals supplied to the coil elements, thereby adjusting the amplitude of the current induced in each coil element by the transmitting system; the transmitting system being arranged to create at least two sets of RF excitation pulses with differently weighted input signals, and to transmit the at least two sets of RF excitation pulses to the coil elements, the weight factors of the at least two sets of RF excitation pulses being selected such that, when the input signals are supplied to the N coil elements, the spatial locations at which the total electric field generated by the RF excitation pulses of each of the at least two sets of RF excitation pulses is negligible are spatially shifted from each other; and an image processor arranged to compute an electric permittivity map from magnetic resonance signals induced by each of the at least two sets of RF excitation pulses, wherein the image processor is further arranged to combine the computed permittivity maps to generate a corrected permittivity map corrected for regions in which said total electric field is near zero in one of said permittivity maps.