Accurate Quantification of 1H Spectra: From Finite Impulse Response Filter Design for Solvent Suppression to Parameter Estimation
Source: Journal of Magnetic Resonance, Volume 139, Number 2, August 1999 , pp. 189-204(16)
Publisher: Academic Press
Abstract:A scheme for accurate quantification of 1H spectra is presented. The method uses maximum-phase finite impulse response (FIR) filters for solvent suppression and an iterative nonlinear least-squares (NLLS) algorithm for parameter 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 filter is designed in such a way that no distortion of the important initial samples 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 FIR method, using an automatic filter design scheme, slightly outperforms the HSVD method in most cases. The good performance and ease of use of the FIR filter method combined with its low computational complexity motivate the use of the proposed method.
Document Type: Research Article
Affiliations: 1: Department of Systems and Control, Uppsala University, Uppsala, SE-75103, Sweden 2: Department of Electrical Engineering (ESAT), Katholieke Universiteit Leuven, Kard. Mercierlaan 94, Leuven, 3001, Belgium 3: Biomedical NMR Unit, Katholieke Universiteit Leuven, Leuven, Gasthuisberg, 3000, Belgium 4: Institute for Language and Speech Processing (ILSP), 6 Epidavrou str., Athens, 151 25, Greece
Publication date: 1999-08-01