PROBLEM TO BE SOLVED: To provide a slice selective excitation method for suppressing extension of an imaging time and selectively exciting a target slice without any positional deviation of the excitation slice due to chemical shift regardless of a simple configuration.SOLUTION: A magnetic resonance imaging apparatus divides an RF pulse for exciting two frequency bands, into multiple times of pulses obtained by dividing an intended flip angle at a ratio following the binominal distribution and excites them respectively. The two frequency bands accord to a frequency difference of a chemical shift between intended two substances. Further, application interval of the divided RF is defined as a time interval when transverse magnetization of both substances become inverse phase. In the RF pulses to be applied odd-number-th time, phases of the respective excitation RF pulses achieving two frequency bands are same, however, in the RF pulses to be applied even-number-th time, the phases of the two-frequency-band excitation RF pulses are inverted.SELECTED DRAWING: Figure 4COPYRIGHT: (C)2017,JPO&INPIT【課題】撮影時間の延長を抑え、簡易な構成で、化学シフトによる励起スライスの位置ずれなしに、目的のスライスを選択励起するスライス選択励起方法を提供する。【解決手段】2周波数帯域を励起するRFパルスを、目的とするフリップ角を2項分布に従う割合で分割した複数回のパルスに分割してそれぞれ励起を行う。2周波数帯域は、目的とする2つの物質間の化学シフトの周波数差に合わせる。また、分割したRFの印加間隔は、両物質の横磁化が逆位相となる時間間隔とする。また、奇数回目に印加するRFパルスでは2周波数帯域を実現する各励起RFパルスの位相は同位相で印加し、偶数回目に印加するRFパルスでは、2周波数帯域の励起RFパルスの位相を逆位相で印加する。【選択図】図4
