Nuclear relaxation time images by radiofrequency field gradients applied to the study of solvent permeation into polymeric materials

T-2 images are obtained by two interleaved B-1-gradient imaging experiments preceded by CPMG trains of different lengths. The method is assessed by me ans of a phantom involving compartments of different, though relatively clo se, T-2 values. T-1 images arise from a previously published procedure also based on two interleaved B-1-gradient imaging experiments involving differ ent evolution of the longitudinal magnetization. Both types of image appear to be useful in view of the structural characterization of polymer samples through the T-2 and T-1 distribution of a solvent embedded in the material . (C) 2001 Academic Press.