Yi Sui1,2, Haoyang Xing2, Theodore Claiborne2, Keith R. Thulborn2,3, Xiaohong Joe Zhou2,4
1Department of Bioengineering, University of Illinois at Chicago, Chicago, IL, United States; 2Center for Magnetic Resonance Research, University of Illinois Medical Center, Chicago, IL, United States; 3Department of Radiology, University of Illinois Medical Center, Chicago, IL, United States; 4Departments of Radiology, Neurosurgery & Bioengineering, University of Illinois Medical Center, Chicago, IL, United States
In this study, we report multiple techniques to address the challenges of 31P relaxation measurements at 9.4 T. A Look-locker (LL) method was adapted for T1 measurement to shorten the total scan time. A two-tip-angle method was used to address the B1-field non-uniformity problem in the LL sequence. Additionally, quadratic-phase modulated RF pulses were employed to reduce RF peak amplitude without compromising the requirement of broad bandwidth of 31P spectrum at 9.4T. By strategically integrating these techniques, 31P relaxation times in human muscle have been determined accurately at 9.4 T within ~30 min.