Abstract
The SPACE volume selection technique was combined with a spin‐echo sequence to measure the transverse relaxation time of the resonances of ethanol and cerebral metabolites in the dog brain, in vivo. The method was extended to measure brain metabolite T~2~, values in the rat using ^1^H NMR microspectroscopy. The T~2~ decays for the resonances of the metabolites N‐acetylaspartate, creatine/phosphocreatine, and choline/phosphorylcholine were found to be biexponential with long T~2~ components of 490, 260, and 350 ms for the dog and 490, 220, and 355 ms for the rat brain, respectively. The existence of a second T~2~ component may originate from J‐coupled nonresolved metabolite resonances. The relaxation decay for the ethanol triplet could be fitted to a single exponential giving a T~2~ relaxation time of 335 ms. However, given the large errors in the measurement of ethanol peak intensities at short echo times because of overlapping lipid signal and the effects of J‐modulation, a biexponential decay with a long T~2~ component of 335 ms cannot be ruled out. Ambiguities regarding the reported partial detection of the ^1^H NMR signal of ethanol in the brain are discussed. © 1992 Academic Press, Inc.