Improved slice-selective adiabatic excitation
Article first published online: 11 FEB 2013
Copyright © 2013 Wiley Periodicals, Inc.
Magnetic Resonance in Medicine
Volume 71, Issue 1, pages 75–82, January 2014
How to Cite
Balchandani, P., Glover, G., Pauly, J. and Spielman, D. (2014), Improved slice-selective adiabatic excitation. Magn Reson Med, 71: 75–82. doi: 10.1002/mrm.24630
- Issue published online: 17 DEC 2013
- Article first published online: 11 FEB 2013
- Manuscript Accepted: 16 DEC 2012
- Manuscript Revised: 17 NOV 2012
- Manuscript Received: 22 AUG 2012
- Lucas Foundation. Grant Numbers: NIH R01 MH080913, NIH-NINDS K99NS070821, P41 EB015891
- GE Healthcare
- Shinnar Le-Roux;
- RF excitation;
- fat suppression
The purpose of this work is to design an improved Slice-selective Tunable-flip AdiaBatic Low peak-power Excitation (STABLE) pulse with shorter duration and increased off-resonance immunity to make it suitable for use in a greater range of applications and at higher field strengths. An additional aim is to design a variant of this pulse to achieve B1-insensitive, fat-suppressed excitation.
The adiabatic SLR algorithm was used to generate a more uniform spectral pulse envelope for this improved radiofrequency pulse for adiabatic slice-selective excitation, called STABLE-2. Pulse parameters were adjusted to design a version of STABLE-2 with a spectral null centered on lipids.
In vivo images obtained of the human brain at 3 and 7 T demonstrate that STABLE-2 provides robust, uniform, slice-selective excitation over a range of B1 values. Phantom and in vivo knee images obtained at 3 T demonstrate the effectiveness of STABLE-2 for fat suppression.
STABLE-2 achieves B1-insensitive slice-selective excitation while providing greater off-resonance immunity and a shorter pulse duration, when compared to the original STABLE pulse. In particular, the 9.8-ms STABLE-2 pulse provides slice selectivity over 120 Hz whereas the 21-ms STABLE pulse is limited to 80 Hz off-resonance. B1-Insensitive fat-suppressed excitation may also be achieved by using a variant of this pulse. Magn Reson Med 71:75–82, 2014. © 2013 Wiley Periodicals, Inc.