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 C2F6 and C3F8 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.