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Hello Adam, Michael, just to follow this up, it is to be expected that an ever-improving piece of software such as vbm8 gives different results with different versions (else there weould be no sense in improving it :). If you want to know what changed, there is a very meticuous chages.txt file in the distribution. Irrespective of that, I think it is generally a really good idea to use one software revision for the (final) analysis of all subjects. Cheers, Marko Adam Gorka wrote: > Hello Michael, > > Our group has been collecting data for two years and we have been > processing it as we go. We noticed the same thing. As we collected data > across time, we updated our versions of vbm8. To make sure the new > versions were the same as the old, we processed the same data with both > versions. The different versions produced different Total Grey Matter > /White Matter/ CSF volumes in the text file generated during > preprocessing. Additionally, the grey matter segmented image produced > was different for the old and new versions. > > I am unsure what is changed across the different versions that produces > this difference. We chose to process all our data with the same version. > Hope this helps. > > Adam > > > > On Fri, Jan 27, 2012 at 1:52 PM, Michael <[log in to unmask] > <mailto:[log in to unmask]>> wrote: > > Hello, > > I've conducted some longitudinal vbm analysis back in spring 2011 > with version vbm8_r409. The results looked promising. However, after > making the upgrade to vbm_r435, I noticed the same exact analysis i > conducted on the same data set yielded different results. Just to > check, I preprocessed the data set using version 409 and also using > 435. So, i'm assuming there is a difference in the preprocessing > calculations and this is due to the upgrade(s)? Has anybody else > experienced this? Your help would greatly be appreciated. > > Thanks, > > Michael > > -- ____________________________________________________ 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 ____________________________________________________