PROBLEM TO BE SOLVED: To obtain a more accurate tissue contrast image such as a water-fat separation image in imaging in a time-series manner by an MRI apparatus.SOLUTION: A static magnetic field inhomogeneity map is created from a plurality of echo signals with different TE that are obtained in a time series, and a water-fat separation image is obtained by using the static magnetic field inhomogeneity map. At the time, a processing for correcting discontinuity of a phase or a frequency in a spatial direction (a spatial direction discontinuity correction processing) is performed on the static magnetic field inhomogeneity map, and a processing for correcting discontinuity in a time-series direction (a time-series direction discontinuity correction processing) is performed. In performing the processing in a time-series direction, necessity for the time-series direction discontinuity correction processing is determined by using the magnitude of an offset of the phase or the frequency. When the time-series direction discontinuity correction processing is determined to be necessary, the discontinuity correction processing in the time-series direction is performed partially or entirely.SELECTED DRAWING: Figure 4【課題】ＭＲＩ装置による時系列に撮像において、より正確な水・脂肪分離画像等の組織コントラスト画像を得る。【解決手段】時系列で得られるＴＥの異なる複数のエコー信号から静磁場不均一マップを作成し、静磁場不均一マップを用いて水・脂肪分離画像を得る。この際、静磁場不均一マップに、位相又は周波数の空間方向の不連続を補正する処理（空間方向不連続補正処理）を行うとともに、時系列方向の不連続を補正する処理（時系列方向不連続補正処理）を行う。時系列方向の処理を行う際に、その位相または周波数オフセットの大きさを用いて、時系列方向不連続補正処理の要否を判断し、要と判断されたときに、時系列方向の不連続補正処理を部分的或いは全体的に行う。【選択図】図４
