Hi,
A fieldmap magnitude image is something that needs to be saved
out from the scanner. When the scanner acquires a fieldmap it
takes two scans - each one with a magnitude and a phase component.
The "fieldmap" ends up being derived from the difference of the two
phase images, and the magnitude map can be an average or just a
single case of either of the magnitude parts of the scans. However, if
the scanner did not save these then you cannot "create" them in any way.
So go back to your scanner operator and see if this magnitude data can
be extracted from any saved version of your data.
All the best,
Mark
On 5 Dec 2011, at 19:06, Suchada Tantisatirapong wrote:
> Hello,
>
> I'm trying to unwrap EPI using FUGUE. I have only a single phase map and no magnitude map. I'm wondering if I can use T1 or T2 image as a magnitude map.
> Could any one please clarify how to calculate the magnitude fieldmap ?
>
> Thank you very much and regards,
> Suchada
>
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