Synchronous radial ¹H and ²³Na dual-nuclear MRI on a clinical MRI system, equipped with a broadband transmit channel

The purpose of this work was to synchronously acquire proton (¹H) and sodium (²³Na) image data on a 3T clinical MRI system within the same sequence, without internal modification of the clinical hardware, and to demonstrate synchronous acquisition with ¹H/²³Na-GRE imaging with Cartesian and radial k-space sampling. Synchronous dual-nuclear imaging was implemented by: mixing down the ¹H signal so that both the ²³Na and ¹H signal were acquired at ²³Na frequency by the conventional MRI system; interleaving ¹H/²³Na transmit pulses in both Cartesian and radial sequences; and using phase stabilization on the ¹H signal to remove mixing effects. The synchronous ¹H/²³Na setup obtained images in half the time necessary to sequentially acquire the same ¹H and ²³Na images with the given setup and parameters. Dual-nuclear hardware and sequence modifications were used to acquire ²³Na images within the same sequence as ¹H images, without increases to the ¹H acquisition time. This work demonstrates a viable technique to acquire ²³Na image data without increasing ¹H acquisition time using minor additional custom hardware, without requiring modification of a commercial scanner with multinuclear capability.