Patch-Probe Excitation for Ultrahigh Magnetic Field Wide-Bore MRI

作者：Bluem Patrick; Kiruluta Andrew; Van de Moortele Pierre Francois; Duh Allison; Adriany Gregor; Popovic Zoya^*

来源：IEEE Transactions on Microwave Theory and Techniques, 2017, 65(7): 2547-2557.

DOI：10.1109/TMTT.2017.2656084

• FEM
• magnetic resonance imaging (MRI)
• patch antenna
• waveguide

In this paper, we present the design of probe excitations for 7- and 10.5-T traveling-wave wide-bore magnetic resonance imaging systems. The probes are 297- and 447-MHz coaxially fed microstrip patches, designed to give a circularly polarized magnetic field when placed in the metallic bore waveguide. Images of a water phantom using the patch probes are obtained and compared with full-wave electromagnetic simulations. Additionally, periodic axial metal strip cylinders are inserted into the bore, resulting in improved field uniformity in a phantom with a simultaneous increase in SNR. The numerical analysis for nonquasi-static fields can be computationally intensive, and the numerical error for finite-element simulations is quantified using modified boundary conditions of the system. When the waveguide effects are taken into account, the mode content in the images compares well to full-wave simulations.

• 出版日期2017-7