Combining Hyperpolarized Xe MR Imaging and Spectroscopy to Non-Invasively Estimate Pulmonary Vascular Resistance.

Hyperpolarized Xe MRI/MRS enables quantitative mapping of function in lung airspaces, membrane tissue, and red blood cells (RBCs) within the pulmonary capillaries. The RBC signal also exhibits cardiogenic oscillations that are reduced in pre-capillary pulmonary hypertension (PH). This effect is obscured in patients with concomitant defects in transfer from airspaces to RBCs, which increase RBC oscillation amplitudes.

Functional gas exchange measures on Xe MRI and spectroscopy are associated with age, sex, and BMI in healthy subjects.

Introduction: Hyperpolarized Xe MRI and spectroscopy is a rapidly growing technique for assessing lung function, with applications in a wide range of obstructive, restrictive, and pulmonary vascular disease. However, normal variations in Xe measures of gas exchange across healthy subjects are not well characterized, presenting an obstacle to differentiating disease processes from the consequences of expected physiological heterogeneity. Here, we use multivariate models to evaluate the role of age, sex, and BMI in a range of commonly used Xe measures of gas exchange.