The combination of single volume spectroscopy and chemical shift imaging. The chemical shift measurement is performed over a selectively-excited volume of interest. Areas with strong distorting signal are not stimulated and therefore do not append signal to the spectra.

See also Hybrid Imaging.

The concentration of Hydrogen atoms in water molecules or in some groups of fat molecules within tissue. Initial MR signal amplitudes are directly related to H+ density in the tissue being imaged.