Hyperpolarized 129Xe Magnetic Resonance Imaging: Tolerability in Healthy Volunteers and Subjects with Pulmonary Disease

Rationale and Objectives: The objective of this study was to evaluate the tolerability of hyperpolarized Xe-129 gas inhaled from functional residual capacity and magnetic resonance imaging in healthy subjects and those with pulmonary disease. Materials and Methods: Twelve healthy volunteers (mean age, 59 +/- 17 years), seven subjects with asthma (mean age, 47 +/- 7 years), 10 subjects with chronic obstructive pulmonary disease (mean age, 74 +/- 4 years), three subjects with cystic fibrosis (mean age, 27 +/- 10 years), and a single subject with radiation-induced lung injury (age, 66 years) were enrolled and evaluated over 43 visits with 136 anoxic inhalations of 500 mL Xe-129 gas mixed with 500 mL He-4 gas. Oxygen saturation and heart rate were monitored during the breath-hold and imaging; subjects were queried for adverse events (AEs) before and immediately following gas inhalation and for 24 hours after the last dose. Results: No subjects withdrew from the study or reported serious, hypoxic, or severe AEs. Over the course of 136 dose administrations, two mild AEs (1%) were reported in two different subjects (two of 33 [6%]). One of these AEs (light-headedness) was temporally related and judged as possibly related to Xe-129 administration and resolved without treatment within 2 minutes. Statistically significant but clinically insignificant changes in oxygen saturation and heart rate were observed after inhalation (P <.001), and both resolved 1 minute later, with no difference between subject groups. Conclusions: Inhalation of hyperpolarized Xe-129 gas and subsequent magnetic resonance imaging were well tolerated in healthy subjects and ambulatory subjects with obstructive and restrictive pulmonary disease.