Assessment of Sequence and Assumption Imperfections on 1-point Dixon 129Xe Gas Exchange MRI Metrics

Motivation: 129Xe gas exchange imaging evaluates multiple pulmonary functional compartments. However, the common 1-point Dixon approach to separate functional components relies on assumptions and is sensitive to imperfections. Goal(s): To assess the effect of assumptions and sequence imperfections on quantitative metrics obtained with 1-point Dixon 129Xe gas exchange imaging. Approach: Simulations were performed to model the error in the quantitative metrics based on these assumptions and imperfections. In-vivo data were collected to support the simulation findings. Results: 129Xe gas exchange imaging metrics obtained using the 1-point Dixon approach are dependent on the accuracy of the assumptions and sequence parameters. Impact: Hyperpolarized 129Xe gas exchange imaging metrics are sensitive to imaging parameters and assumptions. More advanced acquisitions and reconstructions will improve the accuracy and robustness of regional gas exchange metrics.