Techniques in which NMR signals are gathered from the whole object volume to be imaged at once. Many sequential plane imaging techniques can be generalized to volume imaging, at least in principle. Advantages include potential improvement in the signal-to-noise ratio by including signals from the whole volume at once; disadvantages include a bigger computational task for image reconstruction and longer image acquisition times (although the entire volume can be imaged from the one set of data). Also called simultaneous volume imaging.