A new magnetic resonance method was described, as well as the processing of the measured signals, with the aim of establishing diffusion coefficients in heterogeneous materials. The pulsed field gradient stimulated-echo methods had reduced the coupling between the applied magnetic field gradient and a constant internal magnetic field gradient caused by different susceptibilities throughout the sample. When studying systems where it was necessary to minimise the duration of the pulse sequence, or to study diffusion as a function of observation time, the spin-echo method was indicated. The basic idea was to acquire the spin-echo amplitude using pulsed field gradients of opposite signs, and to add/subtract the nuclearmagnetic resonance signals measured in a suitable way. The measurement method and digital signal-processing permitted the elimination of the effect of the static magnetic field upon the measurement accuracy. The proposed method could be used in the development of new magnetic resonance tomography measuring methods.

MRI Method of Diffusion Measurement in Heterogeneous Materials. K.Bartusek, E.Gescheidtova: Measurement Science and Technology, 2008, 19[4], 045504 (8pp)