Now that we know how to produce an NMR signal and get tissue-specific information from protons, how can we determine where the signal is coming from ?
To localize the voxels (single volume elements containing protons), spatial information needs to be encoded into the NMR signal.
Three steps are required :
Decoding of spatial information, included in the NMR signal as modifications of frequency and phase, is performed by an inverse Fourier Transform (see chapter 4).