129Xe-RBC T1 Dependence on Blood Oxygen Saturation

Graham Norquay¹, General Leung¹, Jan Wolber², Gillian M. Tozer¹, Jim M. Wild¹

In this study, the T1 of hyperpolarised (HP) 129Xe in red blood cells (RBCs) was measured in vitro as a function of blood saturation (sO2) on a 1.5T scanner. 129Xe-RBC T1 was found to increase linearly with increasing sO2, where the mechanism believed to be responsible for the 129Xe-RBC T1 sO2 dependence is interactions of 129Xe nuclei with varying concentrations of paramagnetic deoxyhaemoglobin. The observed linearity between 129Xe-RBC T1 and sO2 has positive preclinical and clinical implications, as it may open up the possibility of using HP 129Xe in vivo as a non-invasive quantitative probe for blood oxygenation in tumours.