F-19 MR measurement of oxygen concentration in vivo using perfluorocarbon compounds

The authors investigated the possibility of monitoring PO/sub 2/ levels in vivo using F-19 MR imaging of perfluorocarbon compounds (PFCs). PFCs are particularly suited for bio-medical applications because they are biochemically inert and are able to dissolve oxygen and carbon dioxide. Differential PO/sub 2/ levels are observed as a result of the intrinsic paramagnetic property of oxygen, which significantly affects the T1 of the PFC. An extensive list of PFCs was evaluated and the results confirm that the relaxation rate (T1/sup -1/) increases linearly with PO/sub 2/. However, a change in PO/sub 2/ from 1 to 700 mmHg results in a relatively narrow range of T1 values for some PFCs (400 to 100 msec) but an extended range for others (4,200 to 200 msec). Controlled calibration of the PFCs has been conducted at 0.14T and 0.66T over the range of 0 to 760 mmHg. Representative F-19 MR images involving PFC localization in the lung and liver of animals demonstrate the feasibility of the technique