Dear Eloy,
I must admit to being at a complete loss as to what you mean. When you
say "applying the fnirt", what do you mean? Which of your data are you
fnirting, what are you fnirting it to etc? I am also not clear over
what "red channel" refers to?
Jesper
On 11 Nov 2010, at 11:29, eloy Martínez de las Heras wrote:
> Hi FSL Experts,
>
> I have been trying to register FA images to T1 maps but we are
> stuck in the following issue.
>
> Actually we are missing the fieldmap acquistions that you suggest to
> be used in order to correct the geometrical distortions in diffusion
> images. We understand that this is the best method to success with
> this kind of corrections. I have read this in your forum.
>
> Looking for an alternative, we have done our first co-registration
> between a FA and a T1 using FLIRT. We used 6 DOF as suggested in the
> forum. This seems to be fine. The problem rises up while applying
> the FNIRT. My objective is to extract (segmentate) the Corpus
> Callosum trough the red channel. This red channel has been
> previously extracted from the FA registered in the T1. But, when
> using the FNIRT the structure shrinks and it does not fit to the T1.
>
> We are stuck in this point. Any suggestion that you might give will
> be appreciated.
>
> Is there any way to acquire the fieldmaps in a Siemens TRIO system
> 3T ?
>
> I’ll be willing to provide more details if required.
>
> Thanks,
>
> Eloy Martínez de las Heras
> Enginyer Biomèdic especialista en Neuroimatge
> Department de Neurociències
> Institut d´Investigacions Biomèdiques August Pi i Sunyer.
> Hospital Clinic
> Villarroel 170
> 08036 Barcelona, Spain
>
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