Finite-difference approach for the high-precision analysis of rotating-frame diffusion images

A finite-difference approach has been developed for precisely determining d iffusion coefficient and T-1 relaxation time in fluid samples analyzed by m agnetization-grating rotating-frame imaging (MAGROFI) with either a surface coil or a toroid cavity detector (TCD). This approach avoids shortcomings of phenomenologically based approximations, such as neglect of sample geome tries with singularities at the confines of the sample volume, and accounts for the diffusive edge enhancement observed in fluid imaging. Error limits are discussed. The new method has been applied to the determination of the self-diffusion coefficient for MAGROFI experiments using TCDs filled with acetone. (C) 2000 Academic Press.