ABSTRACT
Magnetic Resonance Spectroscopy (MRS) and Magnetic Resonance Spectroscopic Imaging (MRSI) are among the leading and most rapidly developing non-invasive diagnostic modalities in medicine. While MRS focuses upon a single voxel, the combination of MRS and Magnetic Resonance Imaging (MRI) yields MRSI, which provides information from multiple voxels. The most vivid progress particularly in MRS and MRSI, also uncovered the fact that the indispensable signal processing meets with huge challenges in reliably extracting information about biochemical and physical functionality of the most clinically relevant metabolites of the investigated tissue. The experimentally measured or encoded data from MRS and MRSI are time signals, or alternatively, free induction decay (FID) curves. In both MRS as well as MRSI, it is very important to avoid encoding long FIDs, particularly when employing clinical scanners. The structural parameters are the fundamental frequencies and the associated amplitudes, as the elements from which the attenuated harmonics from the investigated FID are built.
