Recovery & Purification of 3He Gas from Pulmonary MRI

Sean Alexander Lourette¹, Allen W. Che², Jason C. Woods^1,2, Mark S. Conradi^1,2

To reduce the cost of hyperpolarized ³He MR experiments, used for measuring restricted diffusion, ventilation uniformity, and oxygen distribution in lungs, ³He should be recaptured and purified for reuse in future experiments. A device has been constructed that collects exhaled gas into flexible bags, using activated carbon to remove N₂, O₂, and other exhaled contaminants from the ³He by means of physical adsorption at 77 K. The purified ³He is cryogenically recompressed, mixed with nitrogen buffer gas, and used to refill Rb-glass cells for hyperpolarization.