Relaxation and diffusion of perfluorocarbon gas mixtures with oxygen for lung MRI

We report measurements of free diffusivity D₀ and relaxation times T₁ and T₂ for pure C ₂F ₆ and C ₃F ₈ and their mixtures with oxygen. A simplified relaxation theory is presented and used to fit the data. The results enable spatially localized relaxation time measurements to determine the local gas concentration in lung MR images, so the free diffusivity D₀ is then known. Comparison of the measured diffusion to D₀ will express the extent of diffusion restriction and allow the local surface-to-volume ratio to be found.