A novel compartmental model of 129Xe gas exchange using blind estimation of blood concentration

Preclinical to clinical translation of pulmonary gas exchange measurements utilising hyperpolarised 129Xe MRI is limited by the overlapping spectral peaks of dissolved 129Xe MR red blood cell (RBC) and tissue compartments in some preclinical species. We present a novel kinetic model of 129Xe exchange (KMXE) in conjunction with blind estimation techniques to evaluate 129Xe exchange between pulmonary tissue and blood without needing an explicit measurement of RBC signals. Using simulations, we show that kinetic parameter estimates are comparable to those estimated using conventional methods, demonstrating feasibility for evaluating gas exchange kinetics when no distinct RBC spectral peak can be measured.