This project has the purpose of developing and studying the physical techniques needed for producing magnetic resonance images (MRI) of fluorinated compounds which can be injected into the bloodstream. Some such components have already reached a high state of development as blood substitutes, and are far less toxic than any other contrast agents used in radiography or MRI. Present fluorine MRI techniques, however, are not capable of producing high quality anatomic images of the vascular system under condition of field strength and scan time likely to be acceptable clinically; two of the primary reasons are the large NMR spectral widths of the compounds and the loss of signal due to the flow of the blood. We propose to explore several modifications of standard MRI pulse sequences and image reconstruction mathematics which promise to overcome these limitations. We also will explore the utility of imaging other fluorine compounds, as diagnostic contrast agents, which might not be acceptable as a life supporting blood substitutes. The various methods will be evaluated using computer simulation, experiments in phantoms using a 1.4 Tesla research MRI machine, and in preliminary in vivo experiments using rats, rabbits, and cats. The goal is to develop a technique which could be directly applied to fluorine angiography in humans. Non angiographic imaging applications will also be studied.