Adaptable Dual-Tuned Optically Controlled on-Coil RF Power Amplifier for MRI

An adaptable optically controlled RF power amplifier (RFPA) is presented for direct implementation on the Magnetic Resonance Imaging (MRI) transmit coil. Operation at H-1 and multiple X-nuclei frequencies for 7T MRI was demonstrated through the automated tuning of an effective voltage-modulated inductor located in the gate driver circuit of the FET switches in the different amplification stages. Through this automated tuning, the amplifier can be adapted from the control to operate at the selected H-1 and X-nuclei frequency in a multinuclear MRI study. Bench and MRI data acquired with the adaptable dual-tuned on-coil RFPA is presented. This technology should allow a simpler, more efficient and versatile implementation of the multinuclear multichannel MRI hardware. Ultimately, to extend the research on MRI detectable nuclei that can provide new insights about healthy and diseased tissue.