Bei Zhang1, Graham Wiggins1, Qi Duan1, Riccardo Lattanzi1, Daniel K. Sodickson1
1Radiology, Center for Biomedical Imaging, NYU School of Medicine, New York, NY, USA
Using full-wave electrodynamic simulations with a human body model as well as in-vivo human imaging, we explore basic principles of signal distribution and energy deposition for whole-body traveling wave MR driven by a patch antenna at 7T. Both simulations and experimental results demonstrate preferential excitation and energy deposition proximal to the patch antenna, with increasing attenuation at increasing distance. This phenomenon can be explained using simple models of dielectric-filled waveguides. Reflections from dielectric boundaries can result in local field focusing. Incomplete containment of fields from the patch antenna within the scanner bore reduces transmit and receive efficiency.
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