Skip to main content
. Author manuscript; available in PMC: 2009 Nov 1.
Published in final edited form as: Magn Reson Med. 2008 Nov;60(5):1112–1121. doi: 10.1002/mrm.21702

FIG. 3.

FIG. 3

Representative phantom images acquired using the demonstration sequence of Fig. 2. (a) Phantom image with no RD effect. Feedback circuit attenuation = 99 dB and TFB = 0.1 ms, thus even natural RD effects are not expected since transverse magnetization is crushed. The average image intensity was 0.06M0 (see Fig. 4). (b) Phantom image with unaccelerated RD. Feedback attenuation = 99 dB and TFB = 10 ms, thus even though the feedback device does not reinforce the induced currents in the coil, un-accelerated RD acts for the 10ms TFB period prior to destruction of the transverse magnetization by the crusher. The average image intensity was 0.1M0 (see Fig. 4). (c) Phantom image with accelerated RD. The feedback circuit was optimized in both phase and gain (maximum gain; attenuation = 0 dB) and TFB = 10 ms. Comparison of the image intensity with a fully relaxed image (hard pulse set to 0°) shows that the accelerated RD effect was sufficient to return 99% of the longitudinal magnetization to the +z-axis.