This file has simulated 4 coil SENSE data for a variable density spiral acquisition.  The variables are

d  -- a volume coil data set 
fd1, fd2, fd3, fd4 -- single coil data.  
	These are 1280 samples by 21 interleaves.  It reconstructs to a 128x128 image

k -- k-space trajectory
w -- density correction

s1,s2,s3,s4 -- sensitivities for the four coils