Santini Tales, Wood Sossena, Krishnamurthy Narayanan, Martins Tiago, Aizenstein Howard J, Ibrahim Tamer S
Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, USA.
Department of Psychiatry, University of Pittsburgh, Pittsburgh, PA, USA.
Sci Rep. 2021 Feb 9;11(1):3370. doi: 10.1038/s41598-020-79807-9.
Recently cleared by the FDA, 7 Tesla (7 T) MRI is a rapidly growing technology that can provide higher resolution and enhanced contrast in human MRI images. However, the increased operational frequency (~ 297 MHz) hinders its full potential since it causes inhomogeneities in the images and increases the power deposition in the tissues. This work describes the optimization of an innovative radiofrequency (RF) head coil coupled design, named Tic Tac Toe, currently used in large scale human MRI scanning at 7 T; to date, this device was used in more than 1,300 neuro 7 T MRI scans. Electromagnetic simulations of the coil were performed using the finite-difference time-domain method. Numerical optimizations were used to combine the calculated electromagnetic fields produced by these antennas, based on the superposition principle, resulting in homogeneous magnetic field distributions at low levels of power deposition in the tissues. The simulations were validated in-vivo using the Tic Tac Toe RF head coil system on a 7 T MRI scanner.
最近获得美国食品药品监督管理局（FDA）批准的7特斯拉（7T）磁共振成像（MRI）是一项快速发展的技术，它能够在人体MRI图像中提供更高的分辨率和增强的对比度。然而，操作频率的增加（约297兆赫兹）阻碍了其全部潜力的发挥，因为这会导致图像出现不均匀性，并增加组织中的功率沉积。这项工作描述了一种创新的射频（RF）头部线圈耦合设计的优化，该设计名为“井字游戏”，目前用于7T的大规模人体MRI扫描；迄今为止，该设备已用于1300多次7T神经MRI扫描。使用时域有限差分法对线圈进行了电磁模拟。基于叠加原理，采用数值优化方法将这些天线产生计算出的电磁场进行组合，从而在组织中低功率沉积水平下实现均匀的磁场分布。使用7T MRI扫描仪上的“井字游戏”RF头部线圈系统在体内对模拟进行了验证。
