Quantification of in vivo Magnetic Resonance Spectroscopy signals with baseline and lineshape corrections

Quantification of Magnetic Resonance Spectroscopy (MRS) signals is a method to estimate metabolite concentrations of the tissue under investigation. Estimation of these concentrations provides information about the biochemical characteristics of the tissue and are finally used as a complementary information in the diagnosis of cancer, epilepsy and metabolic diseases. Obtaining reliable metabolite concentrations is still a challenge due to the experimental conditions affecting the spectral quality. The decay of MRS signals (lineshape of MR spectra), for instance, is affected by inhomogeneities in the magnetic field caused by shimming problems and tissue heterogeneities. To handle this type of distortions, we study a method where the unsuppressed water is used to correct lineshape distortions, an inversion recovery signal is used to account for macromolecules and lipids present in the tissue and splines are used to correct additional baseline distortions. In this study, we consider rat brain in vivo signals and quantify them taking into account both lineshape distortions and the background signal.