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Is there an interslice gap? Most clinical FLAIR sequences have a pretty sizable slice gap, which plays havoc with any normalization attempt..which is questionable to do in any case. Also, you may want to check if the FLAIR was interleaved acquisition, which can also cause problems if not untangled/reordered prior to normalization. Hope this helps, Jeff --------------------------------------------------------- Jeff Browndyke, Ph.D. Assistant Professor - Dept. of Psychiatry Bryan Alzheimer's Disease Research Center Duke University Medical Center [log in to unmask] --------------------------------------------------------- -----Original Message----- From: SPM (Statistical Parametric Mapping) [mailto:[log in to unmask]] On Behalf Of Clare Emily Bajraszewski Sent: Wednesday, February 06, 2008 7:07 PM To: [log in to unmask] Subject: [SPM] Spatial normalisation of FLAIR scans- error messages I am attempting to use SPM2 to normalise FLAIR (a T2 weighted acquisiton but with CSF suppression) scans for the purpose of lesion identification in multiple sclerosis. I used the following parameters: Preserve concentrations Bounding box- template Voxel sizes 2x2x2 Interpolation method 4th degree b-spline No wrap ... and attempted to normalise FLAIR images (both with and without brain extraction) to a number of different templates (T1, T2, EPI, PD). I keep getting the following error message: 'There is not enough overlap in the images to obtain a solution. Please check that your header information is OK'. Does anyone know what could be causing this, and whether changing any of the default options could fix it? Thanks! Clare Bajraszewski Howard Florey Institute, Melbourne, AUS __________ NOD32 2854 (20080206) Information __________ This message was checked by NOD32 antivirus system. http://www.eset.com