| 摘要 |
NMR images formed by means of Fourier zeugmatography contain disturbing artefacts which are caused by coherent interference signals (for example, off-set signals, non-ideal 180 DEG reversing pulses). In accordance with the invention, an additional phase difference ( DELTA phi = pi in the case of even rows, and DELTA phi = pi . (m-1)/m rad/sec in the case of m odd rows) is generated and the signal samples taken from the resonance signals are stored in adjacently situated rows of an image frequency matrix. The values in every second row of the matrix are changed to cancel said additional phase-difference, so that the contributions of the coherent interference signals to the matrix are influenced by the additional phase shift; if the additional phase shift is pi rad/sec, the values of every second row of interference signals in the direction of the columns are simply inverted. During Fourier transormation of the columns, therefore, the artefacts caused by the interference signals are shifted towards the border of the image.
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