Ibrahim Tamer S
Department of Radiology, University of Pittsburgh, Pittsburgh, PA 15213, USA.
IEEE Trans Med Imaging. 2006 Oct;25(10):1341-7. doi: 10.1109/tmi.2006.880666.
In this paper, a multiport driving mechanism is numerically implemented at ultra high-field (UHF) magnetic resonance imaging (MRI) to provide 1) homogenous whole-slice (axial, sagittal, or coronal) and 2) highly localized radio frequency (RF) field excitation within the same slices, all with the same RF transmit array (here chosen to be a standard transverse electromagnetic (TEM) resonator/coil). The method is numerically tested using a full-wave model of a TEM coil loaded with a high-resolution/18-tissue/anatomically detailed human head mesh. The proposed approach is solely based on electromagnetic and phased array antenna theories. The results demonstrate that both homogenous whole-slice as well as localized RF excitation can be achieved within any slice of the head at 7 T (298 MHz for proton imaging).
在本文中，一种多端口驱动机制在超高场（UHF）磁共振成像（MRI）中通过数值方法得以实现，以在同一切片内实现：1）均匀的全切片（轴向、矢状或冠状）以及2）高度局部化的射频（RF）场激发，且均使用相同的RF发射阵列（此处选择为标准横向电磁（TEM）谐振器/线圈）。该方法通过加载有高分辨率/18组织/解剖学详细的人体头部网格的TEM线圈全波模型进行了数值测试。所提出的方法完全基于电磁和相控阵天线理论。结果表明，在7 T（质子成像为298 MHz）时，头部的任何切片内均可实现均匀的全切片以及局部RF激发。
