ROI Edge Mask SAT

Use Edge Mask SAT with spectroscopy sequences to enable the placement of VSS bands around the VOI to improve spatial saturation. These RF pulses are designed to provide improved spatial saturation performance with no increase in scan time. This allows you to apply saturation bands very close to the VOI without affecting signals within the VOI caused by overlap with the saturation transition band.

• VSS pulses have a very high effective bandwidth and are very appropriate for use in regions of high inhomogeneity or in cases where chemical shift is important. Sharply-defined bandwidths are necessary to cut unwanted signals near or within volumes of interest without unduly impacting the signals of interest.
• You can use the VSS bands to shape the rectangular voxel to better match the anatomy. For example, by cutting off the corners of the ROI. VSS bands should be used to eliminate lipid signals and the susceptibility-shifted signals that may arise at the air-tissue interfaces that are included in the PRESS volume. The VSS bands are prescribed to suppress these lipid signals.
• The default of 7 is recommended in most circumstances.
• The three pairs of VSS RF pulses around the VOI allow independent control of the pulses placed at the R/L, A/P, and S/I edges of the VOI. The selection rules are based on assigning a numeric value to each pair. Use the table below to determine the location of SAT band placement.