Reply-To: | | [log in to unmask][log in to unmask]> wrote:
>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 f�r Kinder- und Jugendmedizin > Leiter, Experimentelle P�diatrische Neurobildgebung > Universit�ts-Kinderklinik > Abt. III (Neurop�diatrie) > > >Marko Wilke, MD, PhD > Pediatrician > Head, Experimental Pediatric Neuroimaging > University Children's Hospital > Dept. III (Pediatric Neurology) > > >Hoppe-Seyler-Str. 1 > D - 72076 T�bingen, Germany > Tel. +49 7071 29-83416 > Fax +49 7071 29-5473 > [log in to unmask] > > http://www.medizin.uni-tuebingen.de/kinder/epn >[log in to unmask] |