Fast echo planar based correlation-peak imaging: demonstration on the rat brain in vivo.

Two-dimensional correlation spectroscopy (2D-COSY) was combined with a fast echo planar based spectroscopic imaging technique in a new sequence. It can be optimized according to the coupling patterns of particular metabolites by using a constant time (CT) variant of COSY with chemical shift selective excitation and refocusing. Experiments were performed with an evolution time of 110 ms which was determined by simulating the CT-COSY experiment at several evolution times for the spin systems of myo-inositol (Ins) and taurine (Tau). The sequence has a minimum total measurement time of 17 min and was tested on a spherical phantom filled with a solution of Ins. The in vivo application of this method on the healthy rat brain demonstrates its improved spectral resolution as cross-peak signals from both Ins and Tau can be separated clearly. Magn Reson Med 44:23-28, 2000. Copyright 2000 Wiley-Liss, Inc.