Abstract: Inner-volume MRI techniques are extended to provide chemical shift NMR spectra for each voxel of an imaged inner-volume of a larger object. Spatial resolution is achieved within a selected inner-volume using multiple phase-encoded NMR measurement cycles with 90.degree. and 180.degree. RF nutation pulses being applied in the presence of inner-volume selective B.sub.o magnetic gradients. However, NMR spin echo RF responses are recorded during readout periods without application of any magnetic gradients. The resulting NMR data is then subjected to one dimension of Fourier Transformation to resolve conventional NMR chemical shift spectra while additional dimensions of Fourier Transformation are used to provide desired spation resolution within the inner-volume.

Abstract: Slice selective 90.degree. and plural subsequent 180.degree. NMR RF pulses are utilized to elicit a train of NMR spin echoes from a given slice or "planar volume" of the object under test in each of plural measurement cycles. Spatial information is encoded within the spin echo by imposing a G.sub.x gradient during each spin echo readout. Phase encoding in a second G.sub.y dimension is achieved by using (1) a cycle-dependent .beta.G.sub.y gradient at least once during each NMR measurement cycle and (2) further .delta.G.sub.y magnetic gradient pulses in association with some or all of the individual spin echo responses within each measurement cycle. The two different types of G.sub.y gradient pulses are dimensioned and timed so as to result in the desired number of phase encoded spin echo signals which subsequently can be arranged in a linearly increasing progression of phase encoding so as to be usable in a two-dimensional Fourier transformation process to produce an NMR image.

Abstract: A unit volume of moving nuclei is spatially tracked by successive selectively applied NMR rf nutation pulses which solicit NMR spin-echo responses from the tracked moving nuclei. For relatively fast moving nuclei, the NMR responses will come only from the successfully tracked moving nuclei. For relatively slowly moving nuclei (where some stationary nuclei in the overlap of selective excitation regions may also be excited to give NMR responses) and/or even for faster moving nuclei, controlled de-phasing/re-phasing magnetic gradients can be applied before and after a 180.degree. rf nutation pulse so as to effectively phase-encode the spin echo response with respect to only those nuclei having velocity. The same NMR excitation/response sequence is repeated a number of times using different de-phasing/re-phasing magnetic gradients and the velocity of the nuclei may then be derived by regression analysis.