GetSliceData[data,offsets]

gets the slices from the data defined by offsets which are obtained by GetSlicePosisions.

GetSliceData[data,offsets,vox]

gets the slices from the data defined by offsets which are obtained by GetSlicePosisions in mm. The offsets can also be provided manually which is {{AX,..},{COR,..},{SAG,..}}.