QUANTITATIVE PROTON MAGNETIC RESONANCE SPECTROSCOPY IN PRESENCE OF SIDEBANDS

We perform proton magnetic resonance spectroscopy (MRS) without water suppression in contrast to traditional water-suppressed MRS. The preserved water signal can be used as a reference for the absolute quantification of metabolites, reducing the total measurement time. However, the non-water-suppressed spectra can be contaminated by gradient-induced frequency modulations resulting in sidebands in the spectrum. Sidebands may obscure the metabolite resonances of interest, thereby rendering the spectral analysis and quantification problematic. To this end, we present a correction technique to remove sidebands. The proposed method utilizes the phase of an external reference of single resonance to observe the time-varying the static field fluctuation induced by gradient-vibrations then deconvolves this phase contamination from the desired signal obtained under the same experimental conditions. The method is evaluated by phantom and in vivo measurements.