Hi,
Indeed it does not look that bad, I have seen much worse.
This odd / even differences in intensities can also be caused by motion.
Neighbouring slices (in space) will experience very different TRs in case of
little motion if you use interleaved excitation.
For that reason I would not use interleaved scanning with FMRI, and always
opt for ascending or descending excitation.
Cheers,
Serge.
On 11-08-2006 08:56, "Andreas Bartsch"
<[log in to unmask]> wrote:
> Hi,
> it does not look too bad on the *.png. However, do you use acsending /
> descending or interleaved excitation? It may be helpful to empüloy the latter.
> Cheers-
> Andreas
>
> ________________________________
>
> Von: FSL - FMRIB's Software Library im Auftrag von Gonzalo Rojas Costa
> Gesendet: Fr 11.08.2006 07:07
> An: [log in to unmask]
> Betreff: [FSL] DICOM to Analyze conversion
>
>
>
> Hi:
>
> We have an Intera 1.5T Philips MR scanner. We use the "Temporal
> Position Identifier" tag (20, 100) to sort the fMRI images for the DICOM
> to Analyze conversion. But, all of the coronal and sagital slices of the
> 35 volumes that we got, shows such as odd slices has different brightnes
> and/or contrast compared with even slices (see attached files)... Which
> could be the problem ?...
>
> Sincerely,
>
>
> Gonzalo Rojas Costa
> Service of Neuroradiology
> Institute of Neurosurgery
> Santiago
> Chile
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