Oxygen tension mapping with F‐19 echo‐planar MR imaging of sequestered perfluorocarbon

The authors used fluorine‐19 inversion‐recovery (IR) echo‐planar imaging (EPI) to map oxygen tension on the basis of the spin‐lattice relaxation rate (R1) of sequestered perfluorocarbon. R1 measured with IR‐EPI varied as a linear function of oxygen tension and temperature, and the relationship agreed well with earlier spectroscopic findings. Oxygen tension maps of a mouse that had received a dose of perflubron emulsion were acquired before, during, and after the mouse breathed pure oxygen. Results showed low liver oxygen tension during air breathing, which increased during breathing of pure oxygen, with distinct regional heterogeneity, to 8–17%atm (60–130 torr [8.0–17.3 kPa]).