| 摘要 |
PROBLEM TO BE SOLVED: To eliminate artifacts inside MR images by calculating the time fluctuation of a phase error included in MR signals from the applied time fluctuation of a gradient magnetic field and correcting the MR signals. SOLUTION: The respective MR signals are obtained by a positive polarity similarly to the negative polarity of a read gradient magnetic field Gu first and the signals are converted to a series of MR data S (t). Then, the time change of the gradient magnetic field Gw (t) vertically extended to a slice surface is calculated corresponding to an equation I. Then, a component Kw (t) in a K space and a phase shiftϕ(t) are calculated by the equations II and III. Then, the measured time change of the signals S(t) is corrected by the addition of the calculated phase error and a signal phase obtained from the time change of the MR signals S(t). That is, the result is obtained in the MR signals S0 (t) corresponding to the equation IV and the phase error is eliminated from it. In such a manner, nuclear magnetization distribution M(u, v) inside an excited slice is reconstituted from the corrected MR signals S0 (t).
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