Accurate quantification of H-1 spectra: From finite impulse response filter design for solvent suppression to parameter estimation

A scheme for accurate quantification of H-1 spectra is presented. The metho d uses maximum-phase finite impulse response (FIR) filters for solvent supp ression and an iterative nonlinear least-squares (NLLs) algorithm for param eter estimation. The estimation algorithm takes the filter influence on the metabolites of interest into account and can thereby correctly incorporate a large variety of prior knowledge into the estimation phase. The FIR filt er is designed in such a way that no distortion of the important initial sa mples is introduced. The FIR filter method is compared numerically with the HSVD method for water signal removal in a number of examples. The results show that the FLR method, using an automatic filter design scheme, slightly outperforms the HSVD method in most cases. The good performance and ease o f use of the FIR filter method combined with its low computational complexi ty motivate the use of the proposed method, (C) 1999 Academic Press.