Figure 1. RF coil used for image acquisition.

The dual frequency coil combines a Helmholtz pair proton coil (transmit and receive, 200 MHz) nested on a single loop ¹²⁹Xe coil (transmit and receive, 55.35 MHz). This coil architecture allowed proton and ¹²⁹Xe images to be acquired sequentially while maintaining exact co-registration (Clinical MR Solutions, Brookfield, WI). The two coils were intrinsically decoupled.