A PITFALL ASSOCIATED WITH LACTATE DETECTION USING STIMULATED-ECHO PROTON SPECTROSCOPY

At TE values of 136 ms, it has recently been shown that the lactate methyl signal, when obtained with a stimulated‐echo (STE) sequence, is modulated at the zero‐quantum (ZQ) frequency when TM is varied. Here we describe an additional modulation of the ZQ lactate signal, due to spin‐spin coupling, that results in a 10‐fold reduction in the lactate signal for TM intervals ranging between 48 and 84 ms (and at multiples of 136 ms thereof). Because of this J‐modulation, improper choice of TE and TM intervals may give false negative results for lactate detection by STE spectroscopy. © 1991 Academic Press, Inc. Copyright © 1991 Wiley‐Liss, Inc., A Wiley Company