MR Spectroscopy (MRS) is a method that provides information on the biochemical composition of tissue. Different chemical compounds have slightly different resonances frequencies, in the order of a few parts per million. The signal acquired is composed of all these different resonant frequencies. A fourier transform of the signal results in a spectrum. Spectroscopy can be obtained non-localized, with volume selection, and with spatial encoding, resulting in multiple voxels with a spectrum. In the latter case, phase encoding gradients needs to be applied. Spectroscopy can be performed on various nuclei, such as 1H, 31P, 13C, 19F, all providing information on different metabolites and different requirements on hardware and pulse sequence design. Increasing the main magnetic field strength has a two-fold benefit for MRS
- An increase in SNR, similar to MR imaging
- An increase in spectral dispersion: the absolute difference in resonance frequencies of the metabolites increases.
Examples
Tools
| FID-A | Simulate and process MRS data | Matlab | Open source |
| Gannet (github) | Batch analysis of edited MRS data | Matlab | Open source |
| jMRUI | Software package for time-domain analysis of MRS and MRSI data | Stand alone | Closed source, free for non-commercial use |
| TARQUIN | Analysis tool for automatically determining the quantities of molecules present in MRS data | Stand alone | Open Source |
| INPSECTOR | Automated MRS analysis | Stand alone | Closed source, acadamic license |
| VeSPA | Simulation, processing and analysis of MRS data | Python | Open source |
External links
Proton Magnetic Resonance Spectroscopy: Technique for the Neuroradiologist! - An introduction to 1H spectroscopy.
