Measurement of glutathione in normal volunteers and stroke patients at 3T using J‐difference spectroscopy with minimized subtraction errors

Abstract

To develop and optimize a (1)H magnetic resonance spectroscopy (MRS) method for measuring brain glutathione (GSH) levels. Phantom experiments and density operator simulations were performed to determine the optimal TE for measuring GSH at 3T using J-difference spectral editing. In vivo data collected from 11 normal volunteers (43 measurements) and five stroke patients (10 measurements) were processed using a new spectral alignment method (adaptive spectral registration). In phantom experiments and density operator simulations where relaxation effects were ignored, close to maximum GSH signal (2.95 ppm) was obtained at TE approximately 131 msec with minimum N-acetyl-aspartate (NAA) signal interference. Using adaptive spectral registration, GSH levels in healthy volunteers were found to be 1.20 +/- 0.14 mM (mean +/- standard deviation [SD]). GSH levels in stroke patients were found to be 1.19 +/- 0.24 mM in lesion and 1.25 +/- 0.19 mM in contralateral normal tissue. In comparison, the SDs were significantly larger when only the NAA singlet (2.01 ppm) was used as a navigator for spectral alignment. Spectral editing using J-differences is a reliable method for measuring GSH levels in volunteers and stroke patients.