Finite Element Simulations of 129Xe Gas Diffusion in Models of Lung Airways

Juan Parra-Robles¹, Steven R. Parnell¹, Salma Ajraoui¹, Xiaojun Xu¹, Jim M. Wild¹

Due to their different diffusivities , ³ and ¹²⁹Xe are sensitive to different length scales of acinar structure. In this work, we investigate short-range ¹²⁹Xe diffusion in a model of acinar airways using finite element computer simulations. The results suggest that ¹²⁹Xe short range diffusion experiments may be more sensitive to alveolar structure than ³He, while being less sensitive to branching effects. This may simplify the development of ¹²⁹Xe-based MR lung morphometry techniques, which could be based on a two compartment model.