MRS 2 D quantification vs 1 D quantification

Introduction Many studies related to in vivo proton Magnetic Resonance Spectroscopy (MRS) led to one dimensional (1D) spectroscopic signal quantification methods including LCModel [1] based on frequency domain or QUEST [2] based on time domain. However, standard in vivo MRS acquisitions in 1D spectroscopy present important limitations. 1D MRS spectra usually present rich in vivo metabolic information through complicated, overlapped spectral signatures with large linewidths especially at moderate field. Accurate concentration quantification remains problematic especially for coupled metabolites such as γ-aminobutyric acid (GABA), Glutamine (Gln), Glutamate (Glu), myo-inositol (mI) and Taurine (Tau). To overcome these limitations, the two dimensional (2D) spectroscopy, which is routinely used in organic chemistry, analytical chemistry and structural biology, has great potential to unravel of the spectral information [3] and especially for decorrelation of coupled metabolite concentration. Very few studies (Profit [4]) on 2D spectroscopic signal quantification were performed. This paper introduces a 2D spectroscopic signal quantification based on a global fitting procedure using strong prior-knowledge in the time domain and investigates the correlation between estimate parameters occurring in 1D vs 2D quantification.