Hi Ben,
Sounds like your data is in a very good form and all you need to do is the multiplication by 2*pi.
A range of +/- 90 Hz is very reasonable and nothing to be concerned about.
The easiest way to get the fieldmap correction incorporated into your analysis is to use it within the FEAT GUI.
Alternatively, using epi_reg is another way of getting it done if you are not using FEAT or a similar GUI (like MELODIC).
All the best,
Mark
On 26 Oct 2012, at 00:46, Ben Jarrett <[log in to unmask]> wrote:
> Hello All,
>
> I am hoping someone with experience using Bruker data can help me with using fieldmap data to correct EPI images. I am working with a Bruker 12T and the fieldmap data comes out as a full fieldmap containing a phase map (in Hz) and also a magnitude image from the 1st echo. So I see that FSL is expecting the phase map to be in rad/s (and from -pi to pi). I know I can convert to rad/s by multiplying by 2pi, but:
>
> The phase data I have from Bruker has a massive range, say some -90,000 to 90,000 Hz. Does this sound possible and how should I proceed to use/convert this data? I've tried following the FUGUE guide and pulled up one previous post on the list serv, but I'm stuck.
>
> Any help or suggestions would be greatly appreciated.
>
> Thanks,
> Ben
>
|