RF Technology Innovation for Advancing High Field MR.

描述（由申请人提供）：近年来MR的一个重要趋势是向更高的磁场（B0）强度发展，这有望通过增强检测灵敏度、代谢物分辨率、成像速度和组织对比度来推进疾病的理解和诊断。然而，存在严重阻碍人类高场MR实践的技术挑战，包括使用射频电磁场- B1和伴随的E场产生MR信号的主要挑战。随着B0强度的增加，由于波行为的增加而导致的B1均匀性的退化通常会导致严重的图像质量问题。同时，电子诱导的射频加热对高性能磁共振序列的应用产生了越来越大的抑制约束。由于能够极大地缓解B1不均匀性和SAR加剧所带来的限制，并行射频传输正在成为高场磁共振的关键使能技术。该项目旨在通过创建自旋激励、射频设备和受试者射频能量沉积的创新解决方案，显著提高人类高场磁共振的能力和安全性。这将通过以下方面的具体努力来实现：a)开发一种急需的非侵入性方法来测量、预测和主动管理SAR； b)利用该方法优化并行激励脉冲，并在7T MR应用中开辟新路；c)改变射频硬件和脉冲设计，以大大提高高场MR系统的性能。该项目的成功完成将带来定量/预测方法，使高场体内成像的全部潜力得以实现，高影响的身体成像应用，以及创新的射频方法，有望将信号产生和检测性能提升到一个新的水平。

DESCRIPTION (provided by applicant): An important trend in MR in recent years has been the move towards higher magnetic field (B0) strengths, which promises to advance disease understanding and diagnosis with enhancements in detection sensitivity, metabolite resolution, imaging speed, and tissue contrast. However there are technical challenges that severely hamper the practice of human high field MR, including a major one that accompanies the creation of MR signal using radio frequency EM fields - B1 and concomitant E fields. As B0 strength increases, the degradation in B1 homogeneity due to increased wave behavior often causes severe image quality issues. Meanwhile E-induced RF heating of the subject body (SAR) poses increasingly inhibiting constraints on the application of high-performance MR sequences. With a great capacity for alleviating the limitations imposed by B1 inhomogeneity and SAR exacerbation, parallel RF transmit is emerging as a key enabling technology for high field MR. This project aims at significantly improving human high field MR capability and safety by creating innovative solutions to spin excitation, RF apparatus, and RF energy deposition in subjects. This will be accomplished with specific efforts on a) developing a much needed non-invasive method for measuring, predicting, and proactively managing SAR, b) leveraging the method in optimizing parallel excitation pulses and in breaking new ground of 7T MR applications, and c) transforming RF hardware and pulse designs to considerably boost high field MR system performance. The successful completion of this project will lead to quantitative / predictive methods that enable the fulfillment of the full potential of in vivo imaging at high field, high impact body imaging applications, and innovative RF methods that promise to bring signal creation and detection performance to a new level.