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 pr ogram with basis sets obtained at other sites is expected to become more wi despread, as such basis sets are now generally available. A calibration pro cedure to estimate absolute concentrations with such imported basis sets is suggested and the implications for differential T-2 attenuation are discus sed. 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 3 0 Ins echo time (TE) spectra was validated against published results that w ere obtained at 2 Tesla and 20 ms TE. Good agreement for both absolute conc entrations and metabolite ratios confirmed the usefulness of LCModel analys is with an imported basis set. However, in white matter, glutamine tended t o be overestimated, and was assigned either to signal-to-noise depending ba seline effects or the use of choline. Mutual interdependence of metabolites inherent to LCModel analysis is discussed in detail. (C) 1999 Elsevier Sci ence Inc.