129Xe signal dynamics and chemical shift in the cardio-pulmonary circuit using cardiac-gated hyperpolarized 129Xe NMR

The sensitivity of the ¹²⁹Xe chemical shift to red blood cell oxygenation makes hyperpolarized ¹²⁹Xe MR spectroscopy a promising technique for measurement of blood oxygenation in vivo. In addition, dissolved phase ¹²⁹Xe MRS is of interest as a biomarker of gas exchange and interstitial lung disease. Both the signal dynamics and chemical shift of ¹²⁹Xe have been shown to be modulated by the cardiac cycle, potentially adding confounding effects to interpretation of the ¹²⁹Xe MRS chemical shift. In this study, we demonstrate that cardiac-gating in ¹²⁹Xe MRS reduces the variability in the measured dissolved ¹²⁹Xe signal and chemical shift in the cardio-pulmonary circuit.