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

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