A magnetic resonance imaging system comprising: a sequence executing unit configured to execute a prep applying portion including a first prepulse for exciting magnetization vectors of a plurality of NMR species having different resonant frequencies due to chemical shift as transverse magnetizations and a second prepulse for nutating back the transverse magnetizations of a subject NMR species out of the plurality of NMR species into longitudinal magnetization, the second prepulse being applied after a phase evolution time by which a predetermined phase difference is evolved between the subject NMR species and the other NMR species of the plurality of NMR species after the first prepulse, and execute a data acquisition sequence after the prep applying portion, wherein the first and second pre-pulses are the RF components of a binomial pulse spaced by the phase evolution time and are followed by at least one magnetic gradient spoiler pulse before the data acquisition sequence,and wherein the predetermined phase difference is substantially equal to π; and an image generating unit configured to generate a separation image of the subject NMR species based on the data acquired by the data acquisition sequence; characterised in that the sequence executing unit is configured to execute the prep applying portion and the data acquisition sequence repeatedly while cycling a transmit phase of at least one of the first and second prepulse in such a manner that combining the plural sets of acquired data provides a more uniform signal across a spectrum of off-resonance NMR signals, and the image generating unit is configured to generate the separation image by combining data acquired by repeatedly executing the data acquisition sequence. a sequence executing unit configured to execute a prep applying portion including a first prepulse for exciting magnetization vectors of a plurality of NMR species having different resonant frequencies due to chemical shift as transverse magnetizations and a second prepulse for nutating back the transverse magnetizations of a subject NMR species out of the plurality of NMR species into longitudinal magnetization, the second prepulse being applied after a phase evolution time by which a predetermined phase difference is evolved between the subject NMR species and the other NMR species of the plurality of NMR species after the first prepulse, and execute a data acquisition sequence after the prep applying portion, wherein the first and second pre-pulses are the RF components of a binomial pulse spaced by the phase evolution time and are followed by at least one magnetic gradient spoiler pulse before the data acquisition sequence,and wherein the predetermined phase difference is substantially equal to π; and an image generating unit configured to generate a separation image of the subject NMR species based on the data acquired by the data acquisition sequence; characterised in that the sequence executing unit is configured to execute the prep applying portion and the data acquisition sequence repeatedly while cycling a transmit phase of at least one of the first and second prepulse in such a manner that combining the plural sets of acquired data provides a more uniform signal across a spectrum of off-resonance NMR signals, and the image generating unit is configured to generate the separation image by combining data acquired by repeatedly executing the data acquisition sequence.