Igi 9600 he

We polarized the imaging gas (³He:N₂ = 99.19:0.81, Linde, Branchburg, NJ) using a commercial polarizer (IGI 9600.He, GE Healthcare, Durham, NC) through spin-exchange collisions with optically pumped rubidium atoms. Approximately 1 liter of ³He with ~30% polarization was attained after ~15 hours of optical pumping. Hyperpolarized ³He gas was diluted with a volume of medical-grade nitrogen gas based on the subject’s weight or total lung capacity (TLC), stored in a Tedlar bag, and mixed with oxygen during gas administration.

Imaging gas (³He:N₂ = 99.19:0.81, Linde, Branchburg, NJ) was polarized via the spin-exchange optical pumping method by inducing spin-exchange collisions with optically pumped rubidium atoms using a commercial polarizer (IGI 9600.He, GE Healthcare, Durham, NC).
After 15 hours of optical pumping, polarization reached levels between 25-35%. Hyperpolarized ³He gas was diluted with medical grade 99.999% purity nitrogen gas according to each subject’s weight and lung capacity. The mixture of ³He and N₂, stored in a Tedlar bag (Jensen Inert Products, Coral Springs, FL) was combined with a 1L bag of O₂ during administration such that an FiO2 of 21% was maintained throughout the study.

The helium gas used for imaging was hyperpolarized using spin exchange collisions with optically pumped rubidium (Rb) atoms, as described [14 (link)] using a commercial prototype polarizer (IGI.9600.He, GE Healthcare, Durham, NC). The gas was polarized to approximately 30% over a period of 14 hours prior to use. During the imaging session, the HP ³He was stored in a 400mL Tedlar bag (Jensen Inert Products, Coral Springs, FA) that was placed inside the magnet's bore. The T₁ relaxation time constant of this gas was in the order of 30-40min inside the bag. The ³He was mixed with O₂ in a 4:1 ratio and delivered to the subjects at 100 BMP with I:E= 1:2 and V_T= 1.2mL/100g body mass.