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Abstract #3827

A Mechanically Tuned 8-Channel Microstrip Array for Parallel Transmission at 7T (297MHz)

Benoit Schaller1, Arthur W. Magill1,2, Rolf Gruetter1,3

1Laboratory of Functional and Metabolic Imaging, Ecole Polytechnique Fdrale de Lausanne, Lausanne, Switzerland; 2Department of Radiology, University of Lausanne; 3Department of Radiology, Universities of Lausanne and Geneva, Switzerland

We present a new 8-channel microstrip array desiged for RF shimming and parallel transmission. Strips, mechanically tuned by adjusting the height over the ground plane, are symmetrically fed via a lattice balun, making the probe tune and match invariant under different loading conditions (different subject). Tuning and matching capacitors are fixed, the array gives a match of better than -23dB with Q=37 (loaded). Coupling between nearest neighbors was -22dB (loaded), and -17dB for the next neighbors, obtained without decoupling capacitors between elements. MR scans showed a penetration of 65mm inside a cylindrical saline phantom (160mm, L=360mm).