A new dedicated double-tuned (100 MHz-27 MHz) volume RF coil actively-decoupled form a receive-only simple-tuned (27 MHz) coil: application to the MRI experiments of hyperpolarized <sup>129</sup>Xe in the rat brain

Abstract

This paper describes the design and development of a new specific RF probe dedicated for the MRI of both proton ( H) and hyperpolarized Xenon-129 (HP 129 Xe) in the rat brain. This probe consists of a double-tuned (100 MHz-27 MHz) volume coil, that could be used for both transmitting and receiving, and of a receive-only simple-tuned (27 MHz). The receive-only coil is a surface coil which is decoupled form the volume coil by an active decoupling circuitry based on the use of PIN diodes. The double-tuned volume coil consists of two concentric birdcage resonators. The inner one is of type low-pass and tuned to 27 MHz, while the outer one, tuned to 100 MHz, is of type high-pass. A transmit/Receive (T/R) driver was realized to bias the PIN diodes in both volume and surface coils. The developed prototype was validated at 100 MHz and at 26.4 MHz. First obtained MRI images show the feasibility of our approach.