Three-Dimensional Echo-Planar Spectroscopic Imaging

**Semantic type:** Diagnostic Procedure

**Definition:** A three-dimensional application of magnetic resonance spectroscopic imaging that uses an alternating gradient applied along one of the spatial readout directions to simultaneously encode the space and chemical shift, thereby reducing the phase-encoding dimension by one and increasing speed.

**Synonyms:** - 3D-EPSI - Volumetric Echo-Planar Spectroscopic Imaging