Measurements of human brain ethanol T-2 by spectroscopic imaging at 4 T

Previous MRS measurements of ethanol in human brain have yielded a range of transverse relaxation times for ethanol methyl resonance at 1.5 T (200-380 ms). To determine the T,of the methyl proton resonance of ethanol in human brain, 8 x 8 spectroscopic images were acquired at 16 different TE values. A frequency-selective refocusing pulse was used to suppress J-modulation o f the ethanol triplet, permitting nonintegral multiples of 1/J to be used f or TE values. The measured T,values for the methyl resonances of ethanol, c reatine, and N-acetyl aspartate in mixed tissues were 82 +/- 12, 148 +/- 20 , and 227 +/- 25 ms, respectively. Regression analysis of the measured T,as a function of gray matter content indicates a shorter T,value for ethanol in pure white matter compared to that in pure gray matter. (C) 2000 Wiley-L iss, Inc.