Abstract #0198

Mapping of 3He Apparent Diffusion Coefficient Anisotropy at Sub-Millisecond Diffusion Times in Sham-Instilled and Elastase-Instilled Rat Lungs

Xiaojun Xu^1,2, Juan Parra-Robles³, Alexei Ouriadov¹, Giles E. Santyr^1,4

¹Imaging Laboratories, Robarts Research Institute, London, Ontario, Canada; ²Department of Physics, University of Western Ontario, London, Ontario, Canada; ³University of Sheffield, Sheffield, United Kingdom; ⁴Department of Medical Biophysics, University of Western Ontario, London, Ontario, Canada

³He diffusion in the lungs is restricted by airway and alveoli walls and therefore is highly dependent on lung microstructure. ³He ADC has been shown to be sensitive to changes in terminal airway anatomy, specifically alveolar damage due to emphysema in both humans and animal models. At the terminal airway, ³He diffusion has been demonstrated to be anisotropic, described by longitudinal diffusion coefficient (D_L) and transverse diffusion coefficient (D_T). The purpose of this work was to measure and compare D_L and D_T maps in sham-instilled and elastase-instilled Wistar rats at two sub-millisecond (360 μs and 800 μs ).