A Double-Tuned 1H/23Na Two Element Phased Array System for in Vivo 23Na Magnetic Resonance Microscopy at 7 T

Friedrich Wetterling¹, Ute Molkenthin², Sven Junge², Andrew John Fagan³

The aim of this study was to develop a ²³Na two-element phased array as part of a double-tuned ²³Na/¹H resonator system to maximize the ²³Na SNR and acquire ²³Na-Magnetic Resonance Microscopy (²³Na-MRM) images together with high resolution anatomical ¹H MRM images without the need to change the coil system during the experiment. The coil element decoupling was optimized by using two-winding detector elements - a novel approach to improve detector element decoupling in noise-matched phased array designs. An SNR improvement of 25 % in favour of the phased array coil was measured at a depth of 12 mm compared to a transceiver surface coil, which most likely derived from the better detector element decoupling.