title: An automated quantitation of short echo time MRS spectra in an open source software environment: AQSES.
abstract: This paper describes a new quantitation method called AQSES for short echo time magnetic resonance spectra. This method is embedded in a software package available online from www.esat.kuleuven.be/sista/members/biomed/new/ with a graphical user interface, under an open source license, which means that the source code is freely available and easy to adapt to specific needs of the user. The quantitation problem is mathematically formulated as a separable nonlinear least-squares fitting problem, which is numerically solved using a modified variable-projection procedure. A macromolecular baseline is incorporated into the fit via nonparametric modelling, efficiently implemented using penalized splines. Unwanted components such as residual water are removed with a maximum-phase FIR filter. Constraints on the phases, dampings and frequencies of the metabolites can be imposed. AQSES has been tested on simulated MR spectra with several types of disturbance and on short echo time in vivo proton MR spectra. Results show that AQSES is robust, easy to use and very flexible.
authors.affiliation: ESAT-SISTA, K.U. Leuven, Kasteelpark Arenberg 10, B-3001 Leuven-Heverlee, Belgium.
authors.forename: Jean-Baptiste
authors.initials: JB
authors.lastname: Poullet
authors.forename: Diana M
authors.initials: DM
authors.lastname: Sima
authors.forename: Arjan W
authors.initials: AW
authors.lastname: Simonetti
authors.forename: Bart
authors.initials: B
authors.lastname: De Neuter
authors.forename: Leentje
authors.initials: L
authors.lastname: Vanhamme
authors.forename: Philippe
authors.initials: P
authors.lastname: Lemmerling
authors.forename: Sabine
authors.initials: S
authors.lastname: Van Huffel
mesh_terms: D006801:Humans; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008433:Mathematics; D012984:Software; D013997:Time Factors