Analysis of 1.5 Tesla proton MR spectra of human brain using LCModel and an imported basis set

Automated analysis of 1.5 Tesla proton mass MR spectra using the LCModel program with basis sets obtained at other sites is expected to become more widespread, as such basis sets are now generally available. A calibration procedure to estimate absolute concentrations with such imported basis sets is suggested and the implications for differential T-2 attenuation are discussed. Based on STEAM localized spectra from parietal gray (n = 51) and white matter (n = 43), of which 28 (18 rsp) were quantified, the evaluation of 30 Ins echo time (TE) spectra was validated against published results that were obtained at 2 Tesla and 20 ms TE. Good agreement for both absolute concentrations and metabolite ratios confirmed the usefulness of LCModel analysis with an imported basis set. However, in white matter, glutamine tended to be overestimated, and was assigned either to signal-to-noise depending baseline effects or the use of choline. Mutual interdependence of metabolites inherent to LCModel analysis is discussed in detail. (C) 1999 Elsevier Science Inc.