Biological Flow and Process Tracing Using Nuclear and Electron Paramagnetic Resonance

A general discussion of the application of nuclear and electron paramagnetic resonance to determination of blood flow velocities in intact humans is discussed. The feasibility has been proven using mice. The system of measurement essentially utilizes paramagnetic (nonradioactive) tracers. One simple tracing scheme which has been employed experimentally is to saturate the protons in the blood stream and detect the density of these protons as variations occur due to flow. By this means the flow velocity is readily measured. A discussion of paramagnetic resonance theory precedes the discussion of the biological applications.