FIG. 4.

Images of the spherical phantom showing the 1D CSI grid and FT voxel locations with 16 and 32 phase encodes are shown as insets. For SLIM and NL-CSI reconstruction, multiple regions were selected only in the phantom, and the regions closely matched the FT voxel locations and size. The magnitude of the FID signal from voxels 1 and 2 plotted on a semi-log scale is shown: (a and e) FT reconstruction, (b and f) SLIM reconstruction, (c and g) NL-CSI reconstruction, and (d and h) PRESS FID signal from a well-shimmed single-voxel spectroscopy experiment. FT and SLIM reconstructions show nonlinear behavior of the FID signal. NL-CSI-reconstructed signal shows linear behavior, which agrees very well with the reference single-voxel spectroscopy signal.