Richard,
> Sorry for the confusion, I wasn't suggesting that the approach of
> only using a subset of subjects worked because of a eventual group
> difference. I ran the pre-processing using all subjects.
OK, sounds good.
> With resliced I mean that during the DARTEL normalization procedure I
> resliced my scans to a slightly smaller voxel size (from 3mm to 2mm
> isotropic).
Well, it does introduce more interpolation which may or may not be worth
it. I personally would try to avoid it, but it depends on what you want
to to with the data, and what your input data looks like.
> I indeed remember that I read somewhere earlier that the
> wavy lines might have something to do with aliasing. Would smoothing
> the data fix that? And what would the effect be on individual voxels
> time-courses?
John was pretty confident that the wavy lines in DARTEL go away (and do
not hurt) when the data is smoothed, if I remember correctly. As always,
smoothing will create a weighted local average of your data, which will
naturally influence the time courses. But this is neither unexpected nor
unwanted in most cases :)
Cheers,
Marko
--
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PD Dr. med. Marko Wilke
Facharzt für Kinder- und Jugendmedizin
Leiter, Experimentelle Pädiatrische Neurobildgebung
Universitäts-Kinderklinik
Abt. III (Neuropädiatrie)
Marko Wilke, MD, PhD
Pediatrician
Head, Experimental Pediatric Neuroimaging
University Children's Hospital
Dept. III (Pediatric Neurology)
Hoppe-Seyler-Str. 1
D - 72076 Tübingen, Germany
Tel. +49 7071 29-83416
Fax +49 7071 29-5473
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http://www.medizin.uni-tuebingen.de/kinder/epn/
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