| 摘要 |
<p>A long RF pulse is segmented into a plurality of RF pulses segments with nuclei spin refocusing pulses provided after each RF pulse segment to maintain phase coherence off resonance and decrease nuclei spin sensitivity to magnetic field inhomogeneity. The refocusing pulses are preferably 180° rectangular pulses. Magnetic gradient segments associated with the RF pulse segments have supplemental gradients at the beginning and at the end of the gradient segment to ensure that the position in k-space for the segment corresponds to the k-space position of the gradient waveform before division into segments.</p> |
