title: Quantification of human brain metabolites from in vivo 1H NMR magnitude spectra using automated artificial neural network analysis.
abstract: Long echo time (TE=270 ms) in vivo proton NMR spectra resembling human brain metabolite patterns were simulated for lineshape fitting (LF) and quantitative artificial neural network (ANN) analyses. A set of experimental in vivo 1H NMR spectra were first analyzed by the LF method to match the signal-to-noise ratios and linewidths of simulated spectra to those in the experimental data. The performance of constructed ANNs was compared for the peak area determinations of choline-containing compounds (Cho), total creatine (Cr), and N-acetyl aspartate (NAA) signals using both manually phase-corrected and magnitude spectra as inputs. The peak area data from ANN and LF analyses for simulated spectra yielded high correlation coefficients demonstrating that the peak areas quantified with ANN gave similar results as LF analysis. Thus, a fully automated ANN method based on magnitude spectra has demonstrated potential for quantification of in vivo metabolites from long echo time spectroscopic imaging.
authors.affiliation: Pehr Brahe Software Laboratory, The Raahe Institute of Computer Engineering, Finland.
authors.forename: Yrjö
authors.initials: Y
authors.lastname: Hiltunen
authors.forename: Jouni
authors.initials: J
authors.lastname: Kaartinen
authors.forename: Juhani
authors.initials: J
authors.lastname: Pulkkinen
authors.forename: Anna-Maija
authors.initials: AM
authors.lastname: Häkkinen
authors.forename: Nina
authors.initials: N
authors.lastname: Lundbom
authors.forename: Risto A
authors.initials: RA
authors.lastname: Kauppinen
mesh_terms: D001224:Aspartic Acid / Q000031:analogs & derivatives* / Q000032:analysis; D001921:Brain / Q000378:metabolism*; D001923:Brain Chemistry; D002794:Choline / Q000032:analysis; D003404:Creatinine / Q000032:analysis; D006801:Humans; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D016571:Neural Networks, Computer
chemical_list: D001224:Aspartic Acid; C000179:N-acetylaspartate; D003404:Creatinine; D002794:Choline