The design of a double-tuned two-port surface resonator and its application to in vivo Hydrogen- and Sodium-MRI

► Resonator design for 1H- and 23Na-MRI of rodent brain at 7 T is described. ► Single detector element, but two independently-adjustable output channels. ► 23Na SNR was increased by a factor of four compared to similar resonator study. ► 1H ADC and 23Na signal were recorded in an interleaved fashion after stroke. ► Resonator design could be easily modified for 17O, 13C, 31P, 39K, and 43Ca MRI.