 This study demonstrated that 129-XEMI misses can be used to accurately diagnose pre- and post-capillary pulmonary hypertension, pH. It also showed that the combination of 129-XE dynamic misses and gas exchange MI provides unique insight into the simultaneous assessment of both hemodynamic and gas exchange impairments, potentially aiding in the detection of pH. This article was authored by Elayna A. Beer, for us, Alan Easy, John Landlou, and others.