A method of spatial modulation of magnetization using the RF pulse train is described for improved cardiac tagging. The method is based on a sinc-modulated RF pulse train in the presence of constant gradient. Such an RF pulse train yields a rectangular profile of saturated magnetization, and the bandwidth of the sinc envelope controls the width of the saturation tag. Compared to DANTE and SPAMM tagging techniques, this method offers sharper-edged tags and the ability to change the ratio of tag width to tag separation. The approach was implemented on a 9.4 T vertical bore NMR system and demonstrated with both phantom and in vivo mouse heart studies.
Copyright 2002 Wiley-Liss, Inc.