Suppression of water and other noncoupled spins by homonuclear polarization transfer in magnetic resonance imaging

Abstract

The water component of an NMR image is suppressed by selectively detecting only those protons which are coupled to other protons. Selectivity is obtained by polarization transfer between the coupled spins. Since spin-spin coupling is independent of magnetic field strength, the suppression obtainable by polarization transfer is independent of chemical shift. Consequently, this technique does not require extremely homogeneous magnetic field for the separation of water and lipid signals. In addition, water suppression by this technique is independent of T₁ and T₂. Suppression of the water signal intensity has been observed experimentally to be as high as a factor of 100. Suppression is limited only by instrumental imperfections. © 1986 Academic Press, Inc.