Finite Element Simulations of Short-Range 3He Diffusion in a Model of Branching Acinar Airways: Implications for In Vivo Lung Morphmetry

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

In this work, we use finite element simulations of diffusion in a model of branching alveolar ducts to investigate in detail the effects of acinar branching structure on short-range ³He diffusion measurements. The obtained results indicate that branching effects have significant influence in ³He diffusivity, even at short diffusion times. The cylinder model theory do not account for significant dependences upon diffusion time, branching geometry and airway length; and further development and validation is required.