Hello,
We're trying to use field map to unwrap our EPI image. We've used 'fsl_prepare_fieldmap' to convert the unit of field map to rad/s. The output image ranges about -4000 to + 4000. This range seems quite big for us but we're unsure what it supposed to be. What is typical range of the field map in rad/s at 7T? Is there anyway to tell if the field map is converted correctly or not?
I attached the field map for your reference. The command we've used: fsl_prepare_fieldmap SIEMENS FmapPhase.nii.gz FmapMag_brain.nii.gz FmapRads 1.01
And it shows:
Loading volumes
Phase loaded
Magnitude loaded
Mask loaded
Rewrapping phase range to [-pi,pi]
Number of phase splits = 8
Calculating starting matrices (860 by 860)
Finished connection_matrices
2490 constraints left
Did while loop 859 times
Done. Created FmapRads for use with FEAT.
Thank you,
Pei
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