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Hello Anna,

Thank you, I'll give it a read.

Regards,
Ian

On 04/08/17 15:58, Anna wrote:
> Dear all,
>
> Hopefully this manual for B0 unwarping with data from a philips 
> scanner can be of use to you: https://osf.io/hks7x/
>
> It took us quite some time to figure it out, but the results after 
> correcting look good (we also ran it by Mark Jenkinson), so I'm happy 
> that others can now use this and maybe even improve it. Please let me 
> know if you have any questions or suggestions.
>
> For the specific question of shifting voxels in the wrong direction; 
> this may have to do with the scan you acquired, the last part of the 
> manual briefly touches on that.
>
> Cheers,
>
> Anna van 't Veer
>
>
>
> Op 4 aug. 2017 om 16:02 heeft Ian Malone <[log in to unmask] 
> <mailto:[log in to unmask]>> het volgende geschreven:
>
>> Hello,
>>
>> I re-discovered this old post about a S/I gradient in field maps from 
>> Philips scanners, as I'm currently looking at some Philips data which 
>> displays exactly the same issue. Did you ever manage to resolve it?
>>
>> Best wishes,
>> Ian
>>
>> On 09/07/12 16:32, Michael Harms wrote:
>>> My apologies for re-posting this one more time, but I'm really stumped.
>>> I would REALLY appreciate it (and would be happy to treat you to a
>>> beverage of your choice at the next OHBM) if someone that has
>>> successfully acquired and applied field map correction from a Philips
>>> Achieva could contact me with what they had to do.
>>>
>>> I'd be happy to then summarize whatever I learn to the broader FSL-list.
>>>
>>> thanks,
>>> -MH
>>>
>>> On Fri, 2012-06-29 at 11:38 -0500, Michael Harms wrote:
>>>> Hello FEAT users with Philips scanners,
>>>>
>>>> I would be highly appreciative if someone that has successfully applied
>>>> fieldmapping correction (B0 unwarping) using Philips scanner data would
>>>> contact me off the list so that I could pick your brain.
>>>>
>>>> We have data from a multi-site study, of which one site was a Philips
>>>> scanner.  I *thought* that I knew what needed to be done to apply
>>>> fieldmapping correction for the data from this site, but the comparison
>>>> in the Prestats report of "undistorted example_func to undistorted
>>>> fieldmap" clearly shows that we don't have something right.
>>>>
>>>> The odd thing is that the "Unwarping shift map" from the Philips site
>>>> data shows a spatial pattern that is completely different from what we
>>>> observe from 4 different Siemens sites.  Namely, it has a rather strong
>>>> S/I gradient, with negative voxel shifts inferiorly, and positive voxel
>>>> shifts superiorly.  This makes me wonder if what we collected wasn't a
>>>> proper fieldmap (the site collected a FFE with "B0 field map = yes" and
>>>> "delta TE = 2.5 ms"), but if that's the case, I'd like to know what the
>>>> site needs to do differently at the time of acquisition.
>>>>
>>>> Thanks in advance!
>>>> -MH
>>>>
>>>>