[en] This patent describes a procedure for obtaining data about the distribution of parameter values such as nuclear spin density and spin relaxation time in an inhomogenous sample. The magnetic field applied has one, two or three non-homogenous components which give rise to linear field gradients. In the case of two or three components, these gradients are mutually perpendicular. The sample is subjected to a series of nuclear magnetic resonance measurements using different field gradients. The measurements are made at time intervals related to the time intervals of the radiation impulse(s) used. The data from the complete series of measurements are subjected to a Fourier transformation in relation to the magnitude of the gradient. Information is obtained which is spatially distributed in the direction of the gradient. (Th.W.P.)