Hi Douglas
Thanks for your answer. Our problem is actually not directly related to FS. We converted Philips .par/.rec files with two different converters, one of which was recently updated for a new platform and scanner software release, and realized that they produce different q-form matrices.
The FS outputs of the differently converted data were therefore also different.
I will use a vitamin A capsule as a marker to determine the hemisphere.
Cheers Jürgen
On [DATE], "Douglas N Greve" <[ADDRESS]> wrote:
Hi Juergen, how are you judging whether a volume is flipped or not? The freesurfer tools should display properly regardless of the qfactor as long as the qform matrix is correct. doug
On 01/11/2013 08:40 AM, Jürgen Hänggi wrote:
NIFTI q-factor
Dear FS experts
Please can you confirm that the NIFTI q-factor in the NIFTI header has to be negative (e.g. -1) in order to have correct right and left orientation.
When the NIFTI q-factor is positive in my T1-w. and DTI images, then the left and the right hemisphere seem to be flipped.
Thanks in advance Regards Jürgen Hänggi
---------------------------------------------------------------------------- Jürgen Hänggi, Ph.D. Division Neuropsychology Institute of Psychology University of Zurich Binzmuehlestrasse 14, PO Box 25 8050 Zurich, Switzerland 0041 44 635 73 97 (phone office) 0041 76 445 86 84 (phone mobile) 0041 44 635 74 09 (fax office) BIN 4.D.04 (office room number) j.haenggi[at]psychologie.uzh.ch (email) http://www.psychologie.uzh.ch/neuropsy/ (website) http://www.juergenhaenggi.ch (private website)
This e-mail (and any attachment/s) contains confidential and/or privileged information. If you are not the intended recipient (or have received this e-mail in error) please notify the sender immediately and destroy this e-mail. Any unauthorised copying, disclosure or distribution of the material in this e-mail is strictly forbidden. ----------------------------------------------------------------------------