Hi Patrick,
I have no explanation as to why this only happens in some of your
subjects but if the dimensions change in the way you describe then it
looks like you not only coregistered, but coregistered and resliced the
functionals to an anatomical. Reslicing before normalization is, as you
know, not necessary, so I would try to find the part in your script that
does the coregistration and see if there is a reslice command in there
somewhere.
Cheers,
Marko
Patrick Williams wrote:
> I am having a bit of a problem that I am hoping you might help me solve.
> Out of about a dozen participants, after preprocessing, about five have
> dimensions that are inconsistant with the majority of participants.
>
> For simplicity we'll call the two groups Group A and Group B.
>
> After converting the dicom files and prior to slice time correction, the
> dimensions are:
>
> Group A: 64 X 64 X 34
> Group B: 64 X 64 X 34
>
> The dimensions are maintained until coregistration, after which point
> the dimensions are:
>
> Group A: 256 X 256 X 176
> Group B: 64 X 64 X 34
>
> After normalization the dimensions are reduced to:
>
> Group A: 79 X 95 X 68
> Group B: 53 X 63 X 46
>
> At this point I can't figure out what is wrong, since I am using the
> same batch sequence and parameters for all subjects. I did not gather
> the original data, and in fact, the person who did is no longer on the
> project or communicating at all with the researchers. Is it possible
> that there is something in the original dicom files that is leading to
> the change at coregistration? Any help or suggestions are greatly
> appreciated.
>
> -Patrick Williams
--
____________________________________________________
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
[log in to unmask]
http://www.medizin.uni-tuebingen.de/kinder/epn
____________________________________________________
|