He Xiaoxuan, Ertürk M Arcan, Grant Andrea, Wu Xiaoping, Lagore Russell L, DelaBarre Lance, Eryaman Yiğitcan, Adriany Gregor, Auerbach Eddie J, Van de Moortele Pierre-François, Uğurbil Kâmil, Metzger Gregory J
Center for Magnetic Resonance Research, University of Minnesota, Minneapolis, Minnesota.
Magn Reson Med. 2020 Jul;84(1):289-303. doi: 10.1002/mrm.28131. Epub 2019 Dec 17.
To investigate the feasibility of imaging the human torso and to evaluate the performance of several radiofrequency (RF) management strategies at 10.5T.
Healthy volunteers were imaged on a 10.5T whole-body scanner in multiple target anatomies, including the prostate, hip, kidney, liver, and heart. Phase-only shimming and spoke pulses were used to demonstrate their performance in managing the inhomogeneity present at 447 MHz. Imaging protocols included both qualitative and quantitative acquisitions to show the feasibility of imaging with different contrasts.
High-quality images were acquired and demonstrated excellent overall contrast and signal-to-noise ratio. The experimental results matched well with predictions and suggested good translational capabilities of the RF management strategies previously developed at 7T. Phase-only shimming provided increased efficiency, but showed pronounced limitations in homogeneity, demonstrating the need for the increased degrees of freedom made possible through single- and multispoke RF pulse design.
The first in-vivo human imaging was successfully performed at 10.5T using previously developed RF management strategies. Further improvement in RF coils, transmit chain, and full integration of parallel transmit functionality are needed to fully realize the benefits of 10.5T.
研究人体躯干成像的可行性,并评估几种射频(RF)管理策略在10.5T磁场强度下的性能。
健康志愿者在10.5T全身扫描仪上对多个目标解剖部位进行成像,包括前列腺、髋关节、肾脏、肝脏和心脏。仅使用相位匀场和辐条脉冲来展示它们在处理447MHz时存在的不均匀性方面的性能。成像方案包括定性和定量采集,以显示不同对比度成像的可行性。
获得了高质量图像,整体对比度和信噪比极佳。实验结果与预测结果匹配良好,表明先前在7T磁场强度下开发的射频管理策略具有良好的转化能力。仅相位匀场提高了效率,但在均匀性方面存在明显局限性,这表明需要通过单辐条和多辐条射频脉冲设计来增加自由度。
利用先前开发的射频管理策略,首次成功在10.5T磁场强度下进行了人体活体成像。要充分实现10.5T磁场强度的优势,还需要进一步改进射频线圈、发射链以及完全集成并行发射功能。