Method of MR imaging of at least a portion of a body, the method comprising the steps of: - subjecting the portion of the body to an imaging sequence comprising at least one quasi continuous-wave RF pulse of more than 250 ms duration, the RF pulse being transmitted toward the portion of the body via an RF coil arrangement to which RF signals are supplied by two or more RF power amplifiers (201, 202, 701), wherein the RF coil arrangement comprises two or more coil elements, each coil element being assigned to a group (I, II) of coil elements, wherein each group (I, II) of coil elements is associated with at least one RF power amplifier (201, 202, 701) supplying RF signals to the coil elements of the respective group (I, II) of coil elements; wherein the amplitudes and the phases of the RF signals supplied to the RF coil arrangement via the RF power amplifiers (201, 202, 701) are controlled in such a manner that the instantaneous and/or the time-integrated homogeneity of the RF magnetic field distribution of the at least one RF pulse is optimized; the RF power amplifiers (201, 202, 701) being activated alternately during the imaging sequence in a time-multiplexed fashion, wherein the RF power amplifiers (201, 202, 701) associated with different groups (I, II) of coil elements are activated during non-overlapping or partly overlapping time slots, and wherein in the case of a non-overlapping activation of the RF power amplifiers (201, 202, 701), the incoherent sum of the RF signals generated during the different activation periods provides a pre-set sufficient homogeneity of the RF magnetic field distribution of the quasi continuous-wave RF pulse, and in the case of a partly overlapping activation of the two or more RF power amplifiers (201, 202, 701), the RF power amplifiers are operating simultaneously during the quasi continuous-wave irradiation according to the invention, amplitudes and phases are controlled for optimized homogeneity of the RF magnetic field and for minimal RF heating of the quasi continuous-wave RF pulse, wherein in each of the cases, the imaging sequence requires an RF duty cycle that exceeds and/or the RF pulse duration exceeds the specification of at least one of the RF power amplifiers (201, 202, 701); - acquiring MR signals from the portion of the body; and - reconstructing an MR image from the acquired MR signals. - subjecting the portion of the body to an imaging sequence comprising at least one quasi continuous-wave RF pulse of more than 250 ms duration, the RF pulse being transmitted toward the portion of the body via an RF coil arrangement to which RF signals are supplied by two or more RF power amplifiers (201, 202, 701), wherein the RF coil arrangement comprises two or more coil elements, each coil element being assigned to a group (I, II) of coil elements, wherein each group (I, II) of coil elements is associated with at least one RF power amplifier (201, 202, 701) supplying RF signals to the coil elements of the respective group (I, II) of coil elements; wherein the amplitudes and the phases of the RF signals supplied to the RF coil arrangement via the RF power amplifiers (201, 202, 701) are controlled in such a manner that the instantaneous and/or the time-integrated homogeneity of the RF magnetic field distribution of the at least one RF pulse is optimized; the RF power amplifiers (201, 202, 701) being activated alternately during the imaging sequence in a time-multiplexed fashion, wherein the RF power amplifiers (201, 202, 701) associated with different groups (I, II) of coil elements are activated during non-overlapping or partly overlapping time slots, and wherein in the case of a non-overlapping activation of the RF power amplifiers (201, 202, 701), the incoherent sum of the RF signals generated during the different activation periods provides a pre-set sufficient homogeneity of the RF magnetic field distribution of the quasi continuous-wave RF pulse, and in the case of a partly overlapping activation of the two or more RF power amplifiers (201, 202, 701), the RF power amplifiers are operating simultaneously during the quasi continuous-wave irradiation according to the invention, amplitudes and phases are controlled for optimized homogeneity of the RF magnetic field and for minimal RF heating of the quasi continuous-wave RF pulse, wherein in each of the cases, the imaging sequence requires an RF duty cycle that exceeds and/or the RF pulse duration exceeds the specification of at least one of the RF power amplifiers (201, 202, 701); - acquiring MR signals from the portion of the body; and - reconstructing an MR image from the acquired MR signals.