Journal
MAGNETIC RESONANCE IN MEDICINE
Volume 86, Issue 1, Pages 17-32Publisher
WILEY
DOI: 10.1002/mrm.28682
Keywords
magnetic resonance spectroscopy; parallel transmission; RF pulse design; ultrahigh-field imaging
Funding
- National Institute of Biomedical Imaging and Bioengineering [P41 EB027061]
Ask authors/readers for more resources
The study aimed to develop a 3D composite adiabatic pulse for spectroscopic acquisitions and compare its performance against standard methods. The designed pulse achieved simultaneous 2D spatial localization with water and lipid suppression, allowing for high-quality spectra at shorter TE/TR.
Purpose: To develop a 3D composite adiabatic spectral-spatial pulse for refocusing in spin-echo spectroscopy acquisitions and to compare its performance against standard acquisition methods. Methods: A 3D composite adiabatic pulse was designed by modulating a train of parallel transmit-optimized 2D subpulses with an adiabatic envelope. The spatial and spectral profiles were simulated and validated by experiments to demonstrate the feasibility of the design in both single and double spin-echo spectroscopy acquisitions. Phantom and in vivo studies were performed to evaluate the pulse performance and compared with semi-LASER with respect to localization performance, sequence timing, signal suppression, and specific absorption rate. Results: Simultaneous 2D spatial localization with water and lipid suppression was achieved with the designed refocusing pulse, allowing high-quality spectra to be acquired with shorter minimum TE/TR, reduced SAR, as well as adaptation to spatially varying B-0 and B-1(+) field inhomogeneities in both prostate and brain studies. Conclusion: The proposed composite pulse can serve as a more SAR efficient alternative to conventional localization methods such as semi-LASER at ultrahigh field for spin echo-based spectroscopy studies. Subpulse parallel-transmit optimization provides the flexibility to manage the tradeoff among multiple design criteria to accommodate different field strengths and applications.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available