| 摘要 |
The method involves producing frequency- and locality-selective high-frequency pulse sequences with a bipolar selective magnetic field gradient for a resonant nuclear magnetic excitation of a first medium and suppression of the excitation of a second medium. The frequency spectrum of the pulses is chosen so that the spatial resonance area of high frequency pulses for the second medium coincides at a first polarity of the magnetic field gradient with the spatial resonance area of high frequency pulses of opposite polarity. The pulse sequence comprises preferably three pulses at equal intervals, whereby both outer pulses cause a turn of the core magnetization of the first and second medium around a first angle, and the middle pulse causes a turn of the core magnetization of the first and second medium around a second angle twice as much as the first angle, and in opposite directions.
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