Targeted Travelling Wave MRI Using a Coaxial Waveguide

Stefan Alt¹, Marco Mller¹, Reiner Umathum¹, Michael Bock¹

In high field MRI with volume resonators, image quality suffers from the appearance of standing wave patterns. We propose the use of a coaxial waveguide with interrupted inner conductor to guide the RF energy to the designated imaging region. These targeted travelling waves can achieve a more homogenous excitation and reduce SAR outside the FOV. Feasibility of the method is assessed with RF field simulations using a detailed anatomical model as well as with a hardware prototype. Transverse magnetic field and SAR distributions are shown and evaluated on the simulated data and an image from the hardware prototype is shown.