X-nuclear MRS and MRI on a standard clinical proton-only MRI scanner

In light of the growing interest in-vivo deuterium metabolic imaging, hyperpolarized ¹³C, ¹⁵N, ³He, and ¹²⁹Xe imaging, as well as ³¹P spectroscopy and imaging in large animals on clinical MR scanners, we demonstrate the use of a (radio)frequency converter system to allow X-nuclear MR spectroscopy (MRS) and MR imaging (MRI) on standard clinical MRI scanners without multinuclear capability. This is not only an economical alternative to the multinuclear system (MNS) provided by the scanner vendors, but also overcomes the frequency bandwidth problem of some vendor-provided MNSs that prohibit users from applications with X-nuclei of low magnetogyric ratio, such as deuterium (6.536 MHz/Tesla) and ¹⁵N (-4.316 MHz/Tesla). Here we illustrate the design of the frequency converter system and demonstrate its feasibility for ³¹P (17.235 MHz/Tesla), ¹³C (10.708 MHz/Tesla), and ¹⁵N MRS and MRI on a clinical MRI scanner without vendor-provided multinuclear hardware.